SYSTEMS AND METHODS FOR VERTICAL OIL SEPARATION

Description

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority under 35 U.S.C. § 119 to U.S. Provisional Patent Application No. 63/708,446 , filed on Oct. 17, 2024, the entire contents of which are incorporated by reference herein.

TECHNICAL FIELD

The present application relates systems and methods for vertical oil separation within a refrigeration system.

BACKGROUND

Refrigeration systems are often used to provide cooling to temperature-controlled display devices (e.g., cases, merchandisers, etc.) in supermarkets and other similar facilities. Carbon dioxide (CO₂) refrigeration systems are a type of refrigeration system. CO₂ refrigeration systems face unique challenges, particularly in managing oil circulation. In CO₂ refrigeration cycles, oil is necessary for lubricating the compressor but can negatively impact system performance if it circulates through other components. Oil separators are utilized in CO₂ refrigeration systems to remove oil from the refrigerant stream after it exits the compressor. Effective oil separation is particularly important in CO₂ systems due to the high miscibility of oil in CO₂, especially at the high pressures typical of transcritical CO₂ cycles. Without proper oil separation, excessive oil can accumulate in the evaporator and other heat exchangers, reducing heat transfer efficiency and overall system performance.

SUMMARY

This disclosure describes systems and methods for vertical oil separation in a refrigeration system, for example, a vertical centrifugal oil separator in a CO₂ refrigeration system.

In an example implementation, a refrigeration system includes at least one compressor; and an oil separator fluidly coupled to the compressor, the oil separator positioned downstream of the compressor and configured to receive a fluid output from the compressor.

The oil separator includes a housing that includes a first end including a first outer surface and a first inner surface; a second end including a second outer surface and a second inner surface; and a sidewall. The first end, the second end, and the sidewall define a centrifugal chamber. The separator includes a fluid inlet positioned on the sidewall adjacent the first end; a coolant outlet positioned adjacent the first end; an oil outlet positioned adjacent the second end; and a filter fluidly coupled to the coolant outlet. The filter extends from the first inner surface of the first end to the second inner surface of the second end.

In an aspect combinable with the example implementation, the oil separator includes a first annular structure positioned within the centrifugal chamber and coupled to the first inner surface of the first end of the housing.

In another aspect combinable with one, some, or all of the previous aspects, the oil separator includes a second annular structure positioned within the first annular structure and coupled to the second inner surface of the second end of the housing.

In another aspect combinable with one, some, or all of the previous aspects, the filter is positioned within the second annular structure; and an inner portion of the filter is fluidly coupled to the coolant outlet.

In another aspect combinable with one, some, or all of the previous aspects, the first annular structure includes an outer surface and an inner surface; the second annular structure includes an outer surface and an inner surface; and the inner surface of the first annular structure and the outer surface of the second annular structure define a fluid channel.

In another aspect combinable with one, some, or all of the previous aspects, the inner surface of the first annular structure includes one or more first protrusions; the outer surface of the second annular structure includes one or more second protrusions; and the one or more first protrusions and the one or more second protrusions are sized to increase or decrease turbulent flow within the fluid channel.

In another aspect combinable with one, some, or all of the previous aspects, the one or more first protrusions is one or more annular rings that have a radii sized to increase or decrease a Reynolds number within the fluid channel.

In another aspect combinable with one, some, or all of the previous aspects, the first annular structure includes a first end and a second end, the first end of the first annular structure coupled to the first inner surface of the first end of the housing; and the second end of the first annular structure is positioned within the centrifugal chamber.

In another aspect combinable with one, some, or all of the previous aspects, the second annular structure includes a first end and a second end, the second end of the second annular structure coupled to the second inner surface of the second end of the housing; and the first end of the second annular structure is positioned within the centrifugal chamber and within the first annular structure.

In another aspect combinable with one, some, or all of the previous aspects, the second end of the first annular structure and the first end of the second annular structure define a fluid flow path to the filter element.

In another aspect combinable with one, some, or all of the previous aspects, the fluid output from the compressor comprises oil and a refrigerant; and the filter is configured to separate the oil from the refrigerant and direct the oil towards the oil outlet positioned adjacent the second end of the housing.

In another aspect combinable with one, some, or all of the previous aspects, the oil outlet is fluidly coupled to the second annular structure to mitigate oil from reentering the centrifugal chamber.

In another aspect combinable with one, some, or all of the previous aspects, the filter is configured to separate the oil from the coolant and direct the coolant towards the coolant outlet positioned adjacent the first end of the housing.

In another example implementation, a refrigeration system oil separator includes a housing that includes a first end including a first outer surface and a first inner surface; a second end including a second outer surface and a second inner surface; and a sidewall. The first end, the second end, and the sidewall define a centrifugal chamber. The oil separator includes a fluid inlet positioned on the sidewall adjacent the first end; a coolant outlet positioned adjacent the first end; an oil outlet positioned adjacent the second end; and a filter fluidly coupled to the coolant outlet. The filter extends from the first inner surface of the first end to the second inner surface of the second end.

In an aspect combinable with the example implementation, the oil separator includes a first annular structure positioned within the centrifugal chamber and coupled to the first inner surface of the first end of the housing.

In another aspect combinable with one, some, or all of the previous aspects, the oil separator includes a second annular structure positioned within the first annular structure and coupled to the second inner surface of the second end of the housing.

In another aspect combinable with one, some, or all of the previous aspects, the filter positioned within the second annular structure; and an inner portion of the filtering element is fluidly coupled to the coolant outlet.

In another aspect combinable with one, some, or all of the previous aspects, the first annular structure includes an outer surface and an inner surface; the second annular structure includes an outer surface and an inner surface; and the inner surface of the first annular structure and the outer surface of the second annular structure define a fluid channel.

In another aspect combinable with one, some, or all of the previous aspects, the inner surface of the first annular structure includes one or more first protrusions; the outer surface of the second annular structure includes one or more second protrusions; and the one or more first protrusions and the one or more second protrusions is sized to increase or decrease turbulent flow within the fluid channel.

In another aspect combinable with one, some, or all of the previous aspects, the one or more first protrusions is annular rings that have a radii sized to increase or decrease a Reynolds number within the fluid channel.

In another aspect combinable with one, some, or all of the previous aspects, the first annular structure includes a first end and a second end, the first end of the first annular structure coupled to the first inner surface of the first end of the housing; and the second end of the first annular structure positioned within the centrifugal chamber.

In another aspect combinable with one, some, or all of the previous aspects, the second annular structure includes a first end and a second end, the second end of the second annular structure coupled to the second inner surface of the second end of the housing; and the first end of the second annular structure positioned within the centrifugal chamber and within the first annular structure.

In another aspect combinable with one, some, or all of the previous aspects, the second end of the first annular structure and the first end of the second annular structure define a fluid flow path to the filter element.

In another example implementation, a method of operating an oil separator in a refrigeration includes receiving, by a fluid inlet of the oil separator, an amount of a fluid from a compressor, the fluid including coolant and oil; directing, by a first fluid channel of the oil separator, the fluid in a first vertical direction; directing, by a second fluid channel of the oil separator, the fluid in a second vertical direction, the second fluid channel including one or more annular protrusions to increase or decrease turbulent flow of the fluid; adjusting a turbulence of a flow of the fluid with one or more annular protrusions within the second fluid channel; filtering, by a filtering element fluidly coupled to the second fluid channel, the oil from the coolant; directing at least a portion of the oil in the first vertical direction towards an oil outlet; and directing the coolant in the second vertical direction towards a coolant outlet.

The details of one or more implementations of the subject matter described in this specification are set forth in the accompanying drawings and the description below. Other features, aspects, and advantages of the subject matter will become apparent from the description, the drawings, and the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic representation of an exemplary CO₂ refrigeration system having a CO₂ refrigeration circuit, and an oil separator for separating oil in the CO₂ refrigeration circuit according to the present disclosure.

FIG. 2A is a schematic representation of an example implementation of an oil separator for a CO₂ refrigeration system having a CO₂ refrigeration circuit according to the present disclosure.

FIG. 2B is a schematic representation of a portion of the oil separator of FIG. 2A according to the present disclosure.

FIG. 3A illustrates an example assembly step of an assembly method according to the present disclosure.

FIG. 3B illustrates an example assembly step of the assembly method according to the present disclosure.

FIG. 3C illustrates an example assembly step of the assembly method according to the present disclosure.

FIG. 3D illustrates an example assembly step of the assembly method according to the present disclosure.

FIG. 3E illustrates an example assembly step of the assembly method according to the present disclosure.

FIG. 4 illustrates an example oil separator according to the present disclosure.

FIG. 5 illustrates an example oil separator according to the present disclosure.

FIG. 6 illustrates an example oil separator according to the present disclosure.

FIG. 7 illustrates an example oil separator according to the present disclosure.

FIG. 8 illustrates an example oil separator according to the present disclosure.

FIG. 9 illustrates an example oil separator according to the present disclosure.

FIG. 10 illustrates an example oil separator according to the present disclosure.

FIG. 11 illustrates an example process for separating oil according to the present disclosure.

FIG. 12 shows a schematic drawing of a control system for a CO₂ refrigeration system having a CO₂ refrigeration circuit and an oil separator according to the present disclosure.

DETAILED DESCRIPTION

Traditional oil separators designed for conventional refrigerants often struggle with the unique properties of CO₂, including its high operating pressures and the potential for rapid decompression. Additionally, the density of CO₂ at typical discharge conditions is much closer to that of oil compared to other refrigerants, making traditional oil separation less effective.

Embodiments disclosed herein are directed to improved oil separators to effectively remove oil from the CO₂ stream while withstanding the system's operating conditions and maintaining reliability over extended periods of operation.

Embodiments disclosed herein can provide enhanced system efficiency. By removing oil from the refrigerant stream, the heat transfer efficiency of the system's heat exchangers is improved, leading to better overall system performance and reduced energy consumption.

Embodiments disclosed herein can provide extended component lifespan. Minimizing oil circulation in the refrigerant loop reduces wear on system components, particularly valves and heat exchangers, thereby extending their operational life and reducing maintenance requirements.

Embodiments disclosed herein can provide improved compressor lubrication. Ensuring that oil is promptly returned to the compressors maintains proper lubrication, reducing friction and wear on critical compressor components.

Embodiments disclosed herein can provide optimized refrigerant charge. With less oil circulating in the system, the required refrigerant charge can be more accurately determined and maintained, leading to improved system control and efficiency.

Embodiments disclosed herein can provide prevention of oil logging. By separating and returning oil to the compressors, the oil separator helps prevent oil accumulation or “logging” in other parts of the system, which can impair heat transfer and reduce overall system capacity.

Embodiments disclosed herein can provide enhanced system stability. Consistent oil separation and return contribute to more stable system operation, reducing the likelihood of sudden performance fluctuations or system failures due to oil-related issues.

Embodiments disclosed herein can provide compliance with environmental regulations. Efficient oil separation helps maintain the purity of the CO₂ refrigerant, potentially reducing the need for refrigerant replacement and minimizing the system's environmental impact.

A refrigeration system including an oil separator according to the present disclosure is shown by way of examples as a CO₂ refrigeration system and components thereof, according to various exemplary implementations. The CO₂ refrigeration system can be a vapor compression refrigeration system that uses primarily carbon dioxide (i.e., CO₂) as a refrigerant. In some implementations, the CO₂ refrigeration system can be used to provide cooling for temperature-controlled display devices in a supermarket or other similar facility. The CO₂ refrigeration system can include a CO₂ refrigerant circuit. The CO₂ refrigerant circuit can include evaporators, low-temperature (LT) and medium-temperature (MT) compressors, gas coolers, a receiver, an oil separator, and expansion valves. The CO₂ refrigerant circuit can be configured to circulate CO₂ as a refrigerant to provide cooling to the evaporators.

In some implementations, the CO₂ refrigeration system includes a receiving tank (e.g., a flash tank, a refrigerant reservoir, etc.) containing a mixture of CO₂ liquid and CO₂ vapor, and a gas bypass valve. The gas bypass valve can be arranged in series with one or more MT compressors of the CO₂ refrigeration system. The gas bypass valve provides a mechanism for controlling the CO₂ refrigerant pressure within the receiving tank by venting excess CO₂ vapor to the suction side of the CO₂ refrigeration system MT compressors.

The CO₂ refrigeration system includes a controller for monitoring and controlling the pressure, temperature, and/or flow of the CO₂ refrigerant throughout the CO₂ refrigeration system. The controller can interface with instrumentation associated with the CO₂ refrigeration system (e.g., measurement devices, timing devices, pressure sensors, temperature sensors, etc.). The controller can provide appropriate control signals to a variety of operable components of the CO₂ refrigeration system (e.g., compressors, valves, power supplies, flow diverters, etc.) to regulate the pressure, temperature, and/or flow at other locations within the CO₂ refrigeration system. Advantageously, the controller can be used to facilitate efficient operation of the CO₂ refrigeration system, reduce energy consumption, and improve system performance.

FIG. 1 shows an example CO₂ refrigeration system 100 that can include an oil separator according to the present disclosure. In some implementations, the refrigeration system can be configured to use other refrigerants, such as hydrofluorocarbons, ammonia, etc., and associated cooling devices such as condensers, fluid coolers, etc. The illustrated CO₂ refrigeration system 100 can be a vapor compression refrigeration system that uses primarily CO₂ as a refrigerant. CO₂ refrigeration system 100 is shown to include a system of pipes, conduits, or other fluid channels (e.g., fluid conduits 1, 3, 5, 7, and 9) for transporting the CO₂ between various thermodynamic components of the refrigeration system. The thermodynamic components of CO₂ refrigeration system 100 can include a gas cooler/condenser 2, a high-pressure valve 4, a receiving tank 6, a gas bypass valve 8, a medium-temperature (“MT”) system portion 10, and a low-temperature (“LT”) system portion 20. In some implementations, the CO₂ refrigeration system 100 includes one system portion (e.g., MT system portion 10). In some implementations, the CO₂ refrigeration system does not include a gas bypass valve 8.

Gas cooler/condenser 2 can be a heat exchanger, fan-coil unit, or other similar device for removing heat from the CO₂ refrigerant. According to other implementations that can use different refrigerants, the gas cooler/condenser can be a fluid cooler or condensing unit. Gas cooler/condenser 2 is shown receiving CO₂ vapor from fluid conduit 1. In some implementations, the CO₂ vapor in fluid conduit 1 can have a pressure within a range from approximately 45 bar to approximately 100 bar (i.e., about 640 psig to about 1420 psig), depending on ambient temperature and other operating conditions. In some implementations, gas cooler/condenser 2 can partially or fully condense CO₂ vapor into liquid CO₂ (e.g., if system operation is in a subcritical region). The condensation process can result in fully saturated CO₂ liquid or a liquid-vapor mixture (e.g., having a thermodynamic quality between 0 and 1). In other implementations, gas cooler/condenser 2 can cool the CO₂ vapor (e.g., by removing superheat) without condensing the CO₂ vapor into CO₂ liquid (e.g., if system operation is in a supercritical region). In some implementations, the cooling/condensation process is an isobaric process. Gas cooler/condenser 2 is shown outputting the cooled and/or condensed CO₂ refrigerant into fluid conduit 3.

High-pressure valve 4 receives the cooled and/or condensed CO₂ refrigerant from fluid conduit 3 and outputs the CO₂ refrigerant to fluid conduit 5. High-pressure valve 4 can control the pressure of the CO₂ refrigerant in gas cooler/condenser 2 by controlling an amount of CO₂ refrigerant permitted to pass through high-pressure valve 4. In some implementations, high-pressure valve 4 is a high-pressure thermal expansion valve (e.g., if the pressure in fluid conduit 3 is greater than the pressure in fluid conduit 5). In such implementations, high-pressure valve 4 can allow the CO₂ refrigerant to expand to a lower pressure state. The expansion process can be an isenthalpic and/or adiabatic expansion process, resulting in a flash evaporation of the high-pressure CO₂ refrigerant to a lower pressure, lower temperature state. The expansion process can produce a liquid/vapor mixture (e.g., having a thermodynamic quality between 0 and 1). In some implementations, the CO₂ refrigerant expands to a pressure of approximately 38 bar (e.g., about 540 psig), which corresponds to a temperature of approximately 37° F. The CO₂ refrigerant then flows from fluid conduit 5 into receiving tank 6.

Receiving tank 6 (e.g., receiver, receiver tank, etc.) collects the CO₂ refrigerant from fluid conduit 5. In some implementations, receiving tank 6 can be a flash tank or other fluid reservoir. Receiving tank 6 includes a CO₂ liquid portion and a CO₂ vapor portion and can contain a partially saturated mixture of CO₂ liquid and CO₂ vapor. In some implementations, receiving tank 6 separates the CO₂ liquid from the CO₂ vapor. The CO₂ liquid can exit receiving tank 6 through fluid conduits 9. Fluid conduits 9 can be liquid headers leading to either MT system portion 10 or LT system portion 20. The CO₂ vapor can exit receiving tank 6 through fluid conduit 7. Fluid conduit 7 is shown leading the CO₂ vapor to gas bypass valve 8.

Gas bypass valve 8 is shown receiving the CO₂ vapor from fluid conduit 7 and outputting the CO₂ refrigerant to MT system portion 10. In some implementations, gas bypass valve 8 can be operated to regulate or control the pressure within receiving tank 6 (e.g., by adjusting an amount of CO₂ refrigerant permitted to pass through gas bypass valve 8). For example, gas bypass valve 8 can be adjusted (e.g., variably opened or closed) to adjust the mass flow rate, volume flow rate, or other flow rates of the CO₂ refrigerant through gas bypass valve 8. Gas bypass valve 8 can be opened and closed (e.g., manually, automatically, by a controller, etc.) as needed to regulate the pressure within receiving tank 6.

In some implementations, gas bypass valve 8 includes a sensor for measuring a flow rate (e.g., mass flow, volume flow, etc.) of the CO₂ refrigerant through gas bypass valve 8. In other implementations, gas bypass valve 8 includes an indicator (e.g., a gauge, a dial, etc.) from which the position of gas bypass valve 8 can be determined. This position can be used to determine the flow rate of CO₂ refrigerant through gas bypass valve 8, as such quantities can be proportional or otherwise related.

In some implementations, gas bypass valve 8 can be a thermal expansion valve (e.g., if the pressure on the downstream side of gas bypass valve 8 is lower than the pressure in fluid conduit 7). According to one implementation, the pressure within receiving tank 6 is regulated by gas bypass valve 8 to a pressure of approximately 38 bar, which corresponds to about 37° F. This pressure/temperature state (i.e., approximately 38 bar, approximately 37° F.) can facilitate the use of copper tubing/piping for the downstream CO₂ lines of the system.

Additionally, this pressure/temperature state can allow such copper tubing to operate in a substantially frost-free manner.

Still referring to FIG. 1, MT system portion 10 is shown to include one or more expansion valves 11, one or more MT evaporators 12, and one or more MT compressors 14. In various implementations, any number of expansion valves 11, MT evaporators 12, and MT compressors 14 can be present. Expansion valves 11 can be electronic expansion valves or other similar expansion valves. Expansion valves 11 are shown receiving liquid CO₂ refrigerant from fluid conduit 9 and outputting the CO₂ refrigerant to MT evaporators 12. Expansion valves 11 can cause the CO₂ refrigerant to undergo a rapid drop in pressure, thereby expanding the CO₂ refrigerant to a lower pressure, lower temperature state. In some implementations, expansion valves 11 can expand the CO₂ refrigerant to a pressure of approximately 30 bar. The expansion process can be an isenthalpic and/or adiabatic expansion process.

MT evaporators 12 are shown receiving the cooled and expanded CO₂ refrigerant from expansion valves 11. In some implementations, MT evaporators 12 can be associated with display cases/devices (e.g., if CO₂ refrigeration system 100 is implemented in a supermarket setting). MT evaporators 12 can be configured to facilitate the transfer of heat from the display cases/devices into the CO₂ refrigerant. The added heat can cause the CO₂ refrigerant to evaporate partially or completely. According to one implementation, the CO₂ refrigerant is fully evaporated in MT evaporators 12. In some implementations, the evaporation process can be an isobaric process. MT evaporators 12 are shown outputting the CO₂ refrigerant via fluid conduits 13, leading to MT compressors 14.

MT compressors 14 compress the CO₂ refrigerant into a superheated vapor having a pressure within a range of approximately 45 bar to approximately 100 bar. The output pressure from MT compressors 14 can vary depending on ambient temperature and other operating conditions. In some implementations, MT compressors 14 operate in a transcritical mode. In operation, the CO₂ discharge gas exits MT compressors 14 and flows through fluid conduit 1 into gas cooler/condenser 2.

Still referring to FIG. 1, LT system portion 20 is shown to include one or more expansion valves 21, one or more LT evaporators 22, and one or more LT compressors 24. In various implementations, any number of expansion valves 21, LT evaporators 22, and LT compressors 24 can be present. In some implementations, LT system portion 20 can be omitted and the CO₂ refrigeration system 100 can operate with an air conditioning (AC) module interfacing with only MT system portion 10.

Expansion valves 21 can be electronic expansion valves or other similar expansion valves. Expansion valves 21 are shown receiving liquid CO₂ refrigerant from fluid conduit 9 and outputting the CO₂ refrigerant to LT evaporators 22. Expansion valves 21 can cause the CO₂ refrigerant to undergo a rapid drop in pressure, thereby expanding the CO₂ refrigerant to a lower pressure, lower temperature state. The expansion process can be an isenthalpic and/or adiabatic expansion process. In some implementations, expansion valves 21 can expand the CO₂ refrigerant to a lower pressure than expansion valves 11, thereby resulting in a lower temperature CO₂ refrigerant. Accordingly, LT system portion 20 can be used in conjunction with a freezer system or other lower temperature display cases.

LT evaporators 22 are shown receiving the cooled and expanded CO₂ refrigerant from expansion valves 21. In some implementations, LT evaporators can be associated with display cases/devices (e.g., if CO₂ refrigeration system 100 is implemented in a supermarket setting). LT evaporators 22 can be configured to facilitate the transfer of heat from the display cases/devices into the CO₂ refrigerant. The added heat can cause the CO₂ refrigerant to evaporate partially or completely. In some implementations, the evaporation process can be an isobaric process. LT evaporators 22 are shown outputting the CO₂ refrigerant via fluid conduit 23, leading to LT compressors 24.

LT compressors 24 compress the CO₂ refrigerant. In some implementations, LT compressors 24 can compress the CO₂ refrigerant to a pressure of approximately 30 bar (e.g., about 425 psig) having a saturation temperature of approximately 23° F. (e.g., about −5° C.). LT compressors 24 are shown outputting the CO₂ refrigerant through fluid conduit 25. Fluid conduit 25 can be fluidly connected with the suction (e.g., upstream) side of MT compressors 14.

In some implementations, the CO₂ vapor that is bypassed through gas bypass valve 8 is mixed with the CO₂ refrigerant gas exiting MT evaporators 12 (e.g., via fluid conduit 13). The bypassed CO₂ vapor can also mix with the discharge CO₂ refrigerant gas exiting LT compressors 24 (e.g., via fluid conduit 25). The combined CO₂ refrigerant gas can be provided to the suction side of MT compressors 14.

The CO₂ discharge gas exits MT compressors 14 and flows through fluid conduit 1 into gas cooler/condenser 2. In some embodiments, an oil separator 26 is located along fluid conduit 1. As the CO₂ discharge gas leaves the MT compressors 14, it carries with it small amounts of oil that have been entrained during the compression process. The oil separator 26 is configured to separate oil from the CO₂ discharge gas exiting MT compressors 14. The oil separator 26 typically consists of a vessel or chamber through which the CO₂ discharge gas passes. Inside the oil separator 26, various mechanisms such as baffles, mesh pads, or centrifugal force are employed to facilitate the separation of oil droplets from the CO₂ discharge gas. As the CO₂ discharge gas flows through the oil separator 26, the oil droplets coalesce and fall to the bottom of the oil separator 26, where they are collected. The separated oil is then accumulated within the oil separator 26, forming a reservoir at the bottom of the unit. The separated oil may be collected within oil separator 26 and returned to MT compressors 14 and/or LT compressors 24. The return process may be facilitated by the pressure differential between the oil separator 26 and the MT compressors 14 and/or LT compressors 24, or in some examples, by an active oil return system such as a pump.

FIG. 2A depicts an example oil separator 200 according to implementations disclosed herein. The oil separator 200 can be used as the oil separator 26 described above in FIG. 1. The oil separator 200 is fluidly coupled to the compressor (e.g., MT compressors 14 and/or LT compressors 24). The oil separator 200 is positioned downstream of the compressor and configured to receive a fluid output (e.g., CO₂ discharge gas) from the compressor.

In the illustrated example, the oil separator 200 includes a housing 201 that defines a portion of the oil separator 200. The housing 201 includes a first end 202 including a first outer surface 204 and a first inner surface 206. The housing 201 includes a second end 208 including a second outer surface 210 and a second inner surface 212. The housing 201 also includes a sidewall 214. In some embodiments, the sidewall 214 is annular in shape. For example, the sidewall 214 is a cylinder that can be coupled to the first end 202 and the second end 208. In some embodiments, the first end 202 and the second end 208 are welded to the sidewall 214. However, other types of coupling mechanisms can be used to couple the first end 202 and the second end 208 to the sidewall 214.

The first end 202, the second end 208, and the sidewall 214 define a centrifugal chamber 216. The centrifugal chamber 216 is designed to receive a mixture of CO₂ discharge gas and oil. The centrifugal chamber 216 utilizes centrifugal force to assist with the separation of the oil from the CO₂ discharge gas. In particular, the centrifugal chamber 216 utilizes components discussed in more detail below to remove oil from the CO₂ discharge gas to produce a less dense CO₂ refrigerant that can be utilized by the compressors.

The oil separator 200 includes a fluid inlet 218 positioned on the sidewall 214 adjacent the first end 202. The fluid inlet 218 is fluidly coupled to the compressors (e.g., MT compressors 14 and/or LT compressors 24) and configured to receive a fluid output (e.g., CO₂ discharge gas) from the compressors. The fluid inlet 218 directs the fluid output into the centrifugal chamber 216 to begin the oil separation process.

The oil separator 200 includes a coolant outlet 220 positioned adjacent the first end 202. The coolant outlet 220 is configured to direct the flow of a coolant (e.g., the CO₂ refrigerant resulting from the oil separation process) back into the refrigeration cycle. In particular, the coolant outlet 220 can be in fluid communication with the fluid conduit 1.

The oil separator 200 includes an oil outlet 222 positioned adjacent the second end 208. The oil outlet 222 allows for the controlled removal of the oil to prevent excessive accumulation within the centrifugal chamber 216. Proper oil management is important in CO2 systems due to the unique properties of CO2 as a refrigerant, including its high operating pressures and potential for rapid expansion. The oil outlet 222 helps ensure that oil does not build up in heat exchangers or other components, which could reduce heat transfer efficiency or cause other operational issues.

The oil separator 200 includes a filter 224 fluidly coupled to the coolant outlet 220. The filter 224 extends from the first inner surface 206 of the first end 202 to the second inner surface 212 of the second end 208. That is, the filter extends the length of the centrifugal chamber 216. In some embodiments, the filter 224 can be a baffle or mesh. In some embodiments, the oil droplets can be in a range from 0-10 μm, 10-100 μm. As such, the filter can have a baffle or mesh that uses openings in a range between a mesh size (10) and a mesh size (50). In some implementations, the mesh size refers to a number of openings per linear inch in a sieve or screen and has a corresponding micron equivalent that refers to the approximate size of openings in micrometers. For example, a mesh size (10) can correspond to a 2000 micron opening, and a mesh size (50) can correspond to a 297 micron opening. The example range can accommodate different operational requirements and oil separation efficiencies. For example, the mesh size (10) configuration may provide openings for implementations where coarser filtration is sufficient, while the mesh size (50) can be suitable for implementations where a more thorough filtration is desired. However, the mesh size (10) can be utilized in a more thorough filtration implementation, based on factors such as refrigerant type, system capacity, oil characteristics, and desired separation efficiency. In some examples, the filter 224 can have a thickness that is utilized to vary the size of openings of the filter 224. For example, based on the thickness, the filter 224 can be rolled (e.g., wrapped) multiple times to create one or more layers that increase the amount of filtration. That is, a filter 224 with larger openings and a smaller thickness can be rolled multiple times to produce the same result as a filter with smaller openings and a larger thickness. The filter 224 enables the oil separation process to efficiently remove the oil from the CO₂ discharge gas and move the oil towards the oil outlet 222.

The oil separator 200 includes a first annular structure 226 positioned within the centrifugal chamber 216 and coupled to the first inner surface 206 of the first end 202 of the housing 201. The first annular structure 226 can be a cylinder. The first annular structure 226 can include a diameter that is smaller than a diameter of the housing 200 to enable the first annular structure 226 to be positioned within the centrifugal chamber 216 to define a fluid path 227 between the first annular structure 226 and the inner surface of the sidewall 214.

The oil separator 200 includes a second annular structure 228 positioned within the first annular structure 226 and coupled to the second inner surface 212 of the second end 208 of the housing 201. The second annular structure 228 can include a diameter that is smaller than the diameter of the first annular structure 226 to enable the second annular structure 228 to be positioned within the first annular structure 226.

The first annular structure 226 includes an outer surface 232 and an inner surface 234. The second annular structure 228 includes an outer surface 236 and an inner surface 238.

As shown in the illustrated embodiments, the inner surface 234 of the first annular structure 226 and the outer surface 236 of the second annular structure 228 define a fluid channel 240. The fluid channel 240 is in fluid communication with the fluid path 227.

Turning briefly to FIG. 2B, the inner surface 234 of the first annular structure 226 includes one or more first protrusions 242. The outer surface 236 of the second annular structure 228 includes one or more second protrusions 244. The one or more first protrusions 242 and the one or more second protrusions 244 are sized to increase or decrease turbulent flow within the fluid channel 240. In some embodiments, the one or more first protrusions 242 is one or more annular rings that have a radii sized to increase or decrease a Reynolds number within the fluid channel 240. For example, during operation, fluid is input into the centrifugal chamber 216 via the fluid inlet 218 and centrifugal force directs the fluid downward in the configuration of FIG. 2A along the fluid path 227. The fluid is then directed upward in the configuration of FIG. 2A into the fluid channel 240. While the fluid is moving upward in the fluid channel 240, the one or more first protrusions 242 modulate the fluid between laminar and turbulent flow (e.g., modulate a Reynolds number within the fluid channel 240). Increasing or decreasing the Reynolds number refers to altering the factors that influence fluid flow characteristics. To increase the Reynolds number, one can increase the fluid's velocity, increase the characteristic linear dimension (e.g., pipe diameter), increase the fluid's density, or decrease the fluid's dynamic viscosity. Conversely, decreasing the Reynolds number involves the opposite actions: reducing velocity or characteristic dimension, decreasing density, or increasing viscosity. A higher Reynolds number typically indicates more turbulent flow, characterized by irregular fluctuations and mixing within the fluid. Lower Reynolds numbers are associated with more laminar flow, where fluid particles move in smooth layers with minimal mixing between layers.

Returning to FIG. 2A, the first annular structure 226 includes a first end 246 and a second end 248. The first end 246 of the first annular structure 226 is coupled to the first inner surface 206 of the first end 202 of the housing 201. The second end 248 of the first annular structure 226 is positioned within the centrifugal chamber 216. The second annular structure 228 includes a first end 250 and a second end 252. The second end 252 of the second annular structure 228 is coupled to the second inner surface 212 of the second end 208 of the housing 201. The first end 250 of the second annular structure 228 is positioned within the centrifugal chamber 216 and within the first annular structure 226. The second end 248 of the first annular structure 226 and the first end 250 of the second annular structure 228 define a fluid flow path 254 to the filter 224. The filter 224 is positioned within the second annular structure 228 and an inner portion 230 of the filter 224 is fluidly coupled to the coolant outlet 220. As the fluid is moving upward in the fluid channel 240, the fluid reaches the fluid flow path 254. The fluid flow path 254 directs the fluid to the filter 224.

The fluid output (e.g., the CO₂ discharge gas) from the compressor comprises oil and a refrigerant (e.g., the CO₂ refrigerant). The filter 224 is configured to separate the oil from the refrigerant and direct the oil towards the oil outlet 222 positioned adjacent the second end 208 of the housing 201. While the fluid interacts with the filter 224, oil is separated from the fluid and directed downward in the configuration of FIG. 2A towards the oil outlet 222 and the CO₂ refrigerant is directed upwards in the configuration of FIG. 2A towards the coolant outlet 220. The filter 224 is configured to separate the oil from the coolant and direct the coolant towards the coolant outlet 220 positioned adjacent the first end 202 of the housing 201.

Returning to FIG. 2B, the oil outlet 222 is fluidly coupled to the second annular structure 228 to mitigate oil from reentering the centrifugal chamber 216. In particular, the second end 252 of the second annular structure 228 is coupled to the second inner surface 212 to mitigate oil from reentering the centrifugal chamber 216. Further, the second end 252 of the second annular structure 228 includes an aperture 256. The aperture 256 is an opening at the second end 252 of the second annular structure 228. The aperture 256 is sized to enable the oil separated from the fluid to be directed toward the oil outlet 222. To mitigate the oil from reentering the centrifugal chamber 216, the oil outlet 222 includes an opening 258. The opening 258 is positioned at height 260 above the second inner surface 212 of the second end 208 of the housing 201 and positioned below the second end 248 of the first annular structure 226 to avoid mixing with the fluid in the fluid path 227 entering the fluid channel 240. The opening 258 enables the oil to be recirculated into the refrigeration cycle. t

Turning to FIG. 3A, an example of a first assembly 302 of the oil separator 200 is illustrated. In some implementations, the first assembly 302 can include coupling points 304.

These coupling points 304 can define areas where different components are coupled together. The coupling points 304 can be permanent, such as welding, or semi-permanent, such as fasteners, screws, and the like.

In some implementations, the coupling points 304 can be permanent, such as when welding is used. This can provide a robust and durable connection between the components, contributing to the overall stability and leak resistance of the oil separator 200. In other implementations, the coupling points 304 can be semi-permanent, such as when fasteners, screws, or similar elements are used. This can provide a certain degree of flexibility in the assembly and disassembly process, allowing for easier maintenance or replacement of components. Regardless of whether the coupling points 304 are permanent or semi-permanent, they can contribute to the efficient assembly and secure configuration of the oil separator 200. In the context of the example assembly method 300, the coupling points 304 are discussed using welds. However, it should be understood that other methods of creating permanent or semi-permanent coupling points 304 can also be used, depending on the specific requirements of the assembly process. For example, the coupling points 304 can be created using adhesives, rivets, or other suitable joining methods. The choice of method for creating the coupling points 304 can depend on various factors, such as the materials of the components being joined, the desired strength of the connection, and the specific design requirements of the oil separator 200.

In some implementations, the first assembly 302 can include the first annular structure 226 being coupled to the first end 202. The first annular structure 226 can be coupled to the first end 202 via the coupling points 304 on the first inner surface 206. In addition, the coolant outlet 220 can be coupled to the first end 202. Specifically, the coolant outlet 220 can be positioned through the first end 202 and coupled to the first end 202 via coupling points 304. These coupling points 304 can be located on both the first outer surface 204 and the first inner surface 206. This configuration of the coolant outlet 220 and the first end 202 can be seen in the illustration of FIG. 3A.

Moving on to FIG. 3B, an example of a second assembly 306 of the oil separator 200 is depicted. In some implementations, the second assembly 306 can include the coupling of the second annular structure 228 to the second end 208. The second annular structure 228 can be coupled to the second inner surface 212 of the second end 208 via the coupling points 304. In some embodiments, the oil outlet 222 can be coupled to the second end 208. In particular, the oil outlet 222 can be positioned through the second end 208 and coupled to the second end 208 via coupling points 304. These coupling points 304 can be located on both the second outer surface 210 and the second inner surface 212. This configuration of the oil outlet 222 and the second end 208 can be seen in the illustration of FIG. 3B. In some implementations, the positioning and coupling of the oil outlet 222 through the second end 208 can be a part of the second assembly 306. This can provide a secure and efficient configuration for the oil separator 200, contributing to the mitigation of potential leaks.

Continuing with FIG. 3C, an example of a third assembly 308 of the oil separator 200 is illustrated. In some implementations, the third assembly 308 can include the coupling of the fluid inlet 218 to the housing 201. The fluid inlet 218 can be coupled to the housing 201 via the coupling points 304. This configuration of the fluid inlet 218 and the housing 201 can be seen in the illustration of FIG. 3C.

Moving on to FIG. 3D, an example of the second assembly 306 of the oil separator 200 is illustrated. In some implementations, the second assembly 306 can include the positioning of the filter 230 within the second annular structure 228. The filter 230 can be placed in such a way that it abuts the second end 208. In some implementations, the filter 230 can be formed to be able to receive the coolant outlet 220. This can be achieved by placing the filter 230 with a roller on an internal side. This configuration of the filter 230, the second annular structure 228, and the second end 208 can be seen in the illustration of FIG. 3D.

In other implementations, the filter 230 can be designed to have a specific shape or size to optimize the filtration process. For example, the filter 230 can be cylindrical, conical, or any other shape that can facilitate the movement of fluids. The size of the filter 230 can also be adjusted based on the volume of fluid to be processed, the desired filtration efficiency, or other operational parameters of the oil separator 200.

Turning to FIG. 3E, an example of the fully assembled oil separator 200 is illustrated. In some implementations, the first assembly 302, the second assembly 306, and the third assembly 308 can be coupled together to form the oil separator 200. This coupling can define the centrifugal chamber 216 when the assemblies are coupled together via the coupling points 304. In some implementations, the coupling of these assemblies can be achieved through various methods, such as welding, fastening, screwing, and the like, at the coupling points 304. The configuration of the first assembly 302, the second assembly 306, and the third assembly 308, when coupled together, can form the oil separator 200. This configuration can provide a secure and efficient setup for the oil separator 200, contributing to the mitigation of potential leaks. In some implementations, the centrifugal chamber 216 can be defined when the first assembly 302, the second assembly 306, and the third assembly 308 are coupled together via the coupling points 304. The centrifugal chamber 216 can be an integral part of the oil separator 200, providing a space for the separation of oil from other fluids. The configuration of the centrifugal chamber 216 within the oil separator 200 can be seen in the illustration of FIG. 3E.

In some implementations, the assembly method 300 can be adapted to accommodate different types of oil separators or different assembly requirements. For example, the assembly method 300 can be modified to include additional steps or components, or to use different types of coupling points or methods. This can provide a high degree of flexibility in the assembly process, allowing the oil separator 200 to be customized to meet specific needs or requirements.

FIGS. 4-10 illustrate example oil separators that can be used as the oil separator 26 of FIG. 1. The features of the example oil separators of FIGS. 4-10 can be combined with the features of the oil separator 200 of FIG. 2A, and the features of the oil separator of FIG. 2A can be combined with one or more of the features of the example oil separators of FIGS. 4-10. That is, any of the features from the oil separators of FIGS. 2A-10 can be combined. The example oil separators of FIGS. 4-10 operate in a similar manner as the oil separator 200. However, the example oil separators of FIGS. 4-10 include variations of the features of the oil separator 200, as discussed below in more detail.

Turning to FIG. 4, an example oil separator 400 is illustrated. In some implementations, the housing 402 of the oil separator 400 can include a first end 404 and a second end 410, each with their respective outer and inner surfaces. The first end 404 includes a first outer surface 406 and a first inner surface 408, while the second end 410 includes a second outer surface 412 and a second inner surface 414.

In the illustrated embodiment, the housing 402 includes a sidewall 416. The sidewall 416 can extend between the first end 404 and the second end 410 and can be configured to provide structural support to the housing 402. The first end 404, the second end 410, and the sidewall 416 of the housing 402 define a centrifugal chamber 418 within the oil separator 400.

In some implementations, the size and shape of the centrifugal chamber 418 can vary depending on the specific requirements of the system in which the oil separator 400 is used.

In some implementations, the oil separator 400 can include a fluid inlet 420. The fluid inlet 420 is positioned on the sidewall 416 of the housing 402. The positioning of the fluid inlet 420 can be adjacent to the first end 404 of the housing 402. This positioning may facilitate the entry of the mixture of CO2 discharge gas and oil into the centrifugal chamber 418. In the illustrated embodiment, the fluid inlet 420 is designed to direct the fluid mixture into the centrifugal chamber 418 in a manner that promotes the centrifugal separation of the oil from the CO2 discharge gas. For example, the fluid inlet 420 may be oriented to introduce the mixture tangentially into the centrifugal chamber 418, thereby initiating a swirling motion of the mixture within the chamber 418.

In the illustrated embodiment, the oil separator 400 includes a coolant outlet 422. The coolant outlet 422 is positioned adjacent to the first end 404 of the housing 402. This positioning facilitates the exit of the less dense CO2 refrigerant from the centrifugal chamber 418 after the separation of the oil from the CO2 discharge gas.

In some implementations, the oil separator 400 includes a first annular structure 424. The first annular structure 424 is positioned within the centrifugal chamber 418. This positioning allows the first annular structure 424 to interact directly with the mixture of CO2 discharge gas and oil as it is spun within the centrifugal chamber 418. In the illustrated embodiment, the first annular structure 424 is coupled to the first inner surface 408 of the first end 404 of the housing 402.

In the illustrated embodiment, the oil separator 400 includes a second annular structure 426. The second annular structure 426 can be positioned within the first annular structure 424. This positioning enables the second annular structure 426 to interact directly with the mixture of CO2 discharge gas and oil as it is spun within the centrifugal chamber 418. In some implementations, the second annular structure 426 is coupled to the second inner surface 414 of the second end 410 of the housing 402.

In some implementations, the oil separator 400 includes a filter 428. The filter 428 can be positioned within the second annular structure 426. This positioning can allow the filter 428 to interact directly with the mixture of CO2 discharge gas and oil as it is spun within the centrifugal chamber 418. In the illustrated embodiment, the filter 428 is in fluid communication with the coolant outlet 422. This arrangement can allow the less dense CO2 refrigerant to pass through the filter 428 before exiting the oil separator 400 through the coolant outlet 422. The filter 428 can be configured to remove any remaining oil particles from the CO2 refrigerant, thereby ensuring that the CO2 refrigerant exiting the oil separator 400 is substantially free of oil. In some implementations, the size, shape, and material of the filter 428 can vary depending on the specific requirements of the system in which the oil separator 400 is used. For example, the filter 428 can be larger or smaller, or have a different shape, in systems that process different volumes or densities of the CO2 discharge gas and oil mixture. The filter 428 can also be made of a material that is resistant to the CO2 discharge gas and oil mixture, such as a metal or a plastic material.

In some implementations, the oil separator 400 includes one or more protrusions 430. These protrusions 430 can be positioned on the first annular structure 424 and the second annular structure 426. In the illustrated embodiment, the one or more protrusions 430 can be one or more annular rings. These annular rings can have radii sized to increase or decrease a Reynolds number within a fluid channel 432. The fluid channel 432 can be defined by the first annular structure 424 and the second annular structure 426. By adjusting the Reynolds number, the flow characteristics of the mixture within the fluid channel 432 can be controlled, which can in turn affect the efficiency of the separation process. In some implementations, the size, shape, and material of the protrusions 430 can vary depending on the specific requirements of the system in which the oil separator 400 is used. For example, the protrusions 430 can be larger or smaller, or have a different shape, in systems that process different volumes or densities of the CO2 discharge gas and oil mixture.

In some implementations, the oil separator 400 includes an oil outlet 434. The oil outlet 434 can be positioned adjacent to the second end 410 of the housing 402. This positioning can facilitate the exit of the separated oil from the centrifugal chamber 418. The oil outlet 434 can be designed to direct the separated oil out of the oil separator 400 in a controlled manner, thereby preventing any unwanted spillage or leakage of oil. In the illustrated embodiment, the oil separator 400 includes an oil reservoir 436. The oil reservoir 436 can be fluidly coupled to the oil outlet 434. This fluid coupling can allow the separated oil to flow from the oil outlet 434 into the oil reservoir 436. The oil reservoir 436 can serve as a temporary storage for the separated oil, allowing the oil to be collected and removed from the oil separator 400 in a controlled manner.

In the illustrated embodiment, the second annular structure 426 of the oil separator 400 can include one or more apertures 438. These apertures 438 can be located on an end of the second annular structure 426 that is adjacent to the oil outlet 434. This positioning can allow the separated oil to be directed towards the oil outlet 434, facilitating its exit from the centrifugal chamber 418. In some implementations, the one or more apertures 438 can be sized to enable the oil separated from the fluid to be directed toward the oil outlet 434. The size of the apertures 438 can be selected based on the specific requirements of the system in which the oil separator 400 is used. For example, larger apertures 438 can be used in systems that process a larger volume of oil, while smaller apertures 438 can be used in systems that process a smaller volume of oil. In the illustrated embodiment, the apertures 438 guide the flow of the separated oil in a manner that promotes efficient exit from the centrifugal chamber 418.

In some implementations, the oil reservoir 436 of the oil separator 400 can include openings 440. These openings 440 can be positioned offset from each other at a first height 442 and a second height 444. This positioning can allow the separated oil to flow into the oil reservoir 436 at different levels, which can facilitate the collection and removal of the oil from the oil separator 400.

In some implementations, the oil reservoir 436 can be positioned within the centrifugal chamber 418 at the second end 410. This positioning can allow the separated oil to flow directly into the oil reservoir 436 from the centrifugal chamber 418, thereby simplifying the design of the oil separator 400 and potentially improving the efficiency of the oil separation process. In some implementations, when the oil reservoir 436 is positioned within the centrifugal chamber 418, the openings 440 can function as an oil outlet. This can eliminate the need for a separate oil outlet, further simplifying the design of the oil separator 400. In some implementations, the size, shape, and number of the openings 440 in the oil reservoir 436 can vary depending on the specific requirements of the system in which the oil separator 400 is used. For example, the openings 440 can be larger or smaller, or have different shapes, in systems that process different volumes or densities of fluid. The number of openings 440 can be increased or decreased to control the flow rate of the separated oil into the oil reservoir 436.

Turning to FIG. 5, an example oil separator 500 is illustrated. In the illustrated embodiment, the oil separator 500 includes a housing 502. The housing 502 can be a structure that encloses or contains other components of the oil separator 500. The housing 502 can include a sidewall 504. The sidewall 504 can be a barrier or boundary that defines the periphery of the housing 502. The sidewall 504 can be of any suitable shape or size and can be made from any suitable material. The sidewall 504 can be designed to withstand the forces exerted by the fluid within the oil separator 500.

In some implementations, the housing 502 includes a centrifugal chamber 506. In the illustrated embodiment, the oil separator 500 includes a first annular structure 508 positioned within the centrifugal chamber 506. In some implementations, the first annular structure 508 includes a curved ramp 510 that is formed on an outer surface of the first annular structure 508. The curved ramp 510 can be a feature that helps to direct the fluid flow within the centrifugal chamber 506. The curved ramp 510 can be sized to abut the sidewall 504 of the housing 502 to define a fluid flow path that curves around the first annular structure 508 as fluid moves within the centrifugal chamber 506. The curved ramp 510 can be of any suitable shape or size and can be made from any suitable material. The curved ramp 510 can be designed to withstand the forces exerted by the fluid and the centrifugal force within the oil separator 500. For example, a larger curved ramp 510 can be used for higher fluid flow rates, while a smaller curved ramp 510 can be used for lower fluid flow rates. The curved ramp 510 can also influence the fluid flow. For example, a steeper curved ramp 510 can cause the fluid to move faster, while a less steep curved ramp 510 can cause the fluid to move slower.

Turning to FIG. 6, an example oil separator 600 is illustrated. In some implementations, the oil separator 600 includes a housing 602. The housing 602 can be designed with a sidewall 604. The sidewall 604 can be configured in various shapes and sizes to accommodate different operational requirements. In the illustrated embodiment, the housing 602 can also include a centrifugal chamber 606. The centrifugal chamber 606 can be located within the housing 602 and can be designed to facilitate the separation of oil from other fluids. The centrifugal chamber 606 can be configured in various shapes and sizes, and its design can be adjusted based on the specific requirements of the oil separation process.

In some implementations, the oil separator 600 includes a first annular structure 608. This first annular structure 608 can be positioned within the centrifugal chamber 606. The first annular structure 608 can include a curved ramp 610. The curved ramp 610 can be formed on an outer surface of the first annular structure 608. In the illustrated embodiment, the curved ramp 610 is sized to abut the sidewall 604 of the housing 602. This positioning can define a fluid flow path 612 that curves around the first annular structure 608. The fluid flow path 612 can be designed to guide the movement of fluid within the centrifugal chamber 606. The design and positioning of the curved ramp 610 can be adjusted based on the specific requirements of the oil separation process.

In some implementations, the oil separator 600 includes a second annular structure 614. This second annular structure 614 can be positioned within the first annular structure 608. The second annular structure 614 can include one or more protrusions 616. In the illustrated embodiment, these one or more protrusions 616 can be one or more annular rings. The annular rings can have radii sized to increase or decrease a Reynolds number within a fluid channel. This fluid channel can be defined by the first annular structure 608 and the second annular structure 614. The design and positioning of the one or more protrusions 616 can be adjusted based on the specific requirements of the oil separation process.

In some implementations, the fluid flow process through the oil separator 600 can be defined by the first annular structure 608 and the second annular structure 614. The fluid channel, which is defined by these two structures, can guide the fluid through the oil separator 600. In the illustrated embodiment, the fluid enters the centrifugal chamber 606 and is directed along the fluid flow path 612, which curves around the first annular structure 608. The fluid then moves between the first annular structure 608 and the second annular structure 614, passing over the one or more protrusions 616. These protrusions 616 can influence the fluid dynamics within the fluid channel, affecting the separation of oil from the fluid. The specific design and positioning of the first annular structure 608 and the second annular structure 614, as well as the one or more protrusions 616, can be adjusted based on the specific requirements of the oil separation process. The fluid channel can be designed to optimize the efficiency of the oil separation process and can be adjusted to accommodate different types of fluids and different operational conditions.

Turning to FIG. 7, an example oil separator is illustrated. In some implementations, the oil separator 700 includes a housing 702. The housing 702 can be designed to contain various components of the oil separator 700. In the illustrated embodiment, the housing 702 includes a sidewall 704. The sidewall 704 can be configured to provide structural support to the housing 702 and to define the boundaries of the internal space of the housing 702.

In some implementations, the housing 702 includes a centrifugal chamber 706. The centrifugal chamber 706 can be located within the housing 702 and can be defined by the sidewall 704. In the illustrated embodiment, the centrifugal chamber 706 is positioned within the housing 702 and is surrounded by the sidewall 704.

In some implementations, the oil separator 700 includes a first annular structure 708. The first annular structure 708 can be positioned within the centrifugal chamber 706. In the illustrated embodiment, the first annular structure 708 is located within the centrifugal chamber 706, which is defined by the sidewall 704 of the housing 702.

In some implementations, the first annular structure 708 can include one or more curved ramps 710. These curved ramps 710 can be formed on an outer surface of the first annular structure 708. In the illustrated embodiment, the one or more curved ramps 710 are sized to abut the sidewall 704 of the housing 702. The curved ramps 710 can be designed to direct fluid within the centrifugal chamber 706. The shape, size, and number of the curved ramps 710 can vary, providing flexibility in the design and operation of the oil separator 700. The curved ramps 710 can be configured to guide the fluid in a specific direction or pattern within the centrifugal chamber 706, contributing to the efficiency of the oil separation process.

Turning to FIG. 8, an example oil separator 800 is illustrated. In some implementations, the oil separator 800 includes a housing 802. The housing 802 can be designed with a sidewall 804. The sidewall 804 can be configured to contain and direct fluid within the housing 802. In the illustrated embodiment, the housing 802 includes a centrifugal chamber 806. The centrifugal chamber 806 can be designed to facilitate the separation of oil from other fluids. The centrifugal chamber 806 can be located within the housing 802 and can be surrounded by the sidewall 804.

In some implementations, the oil separator 800 includes a first annular structure 808. This first annular structure 808 can be positioned within the centrifugal chamber 806. The first annular structure 808 can include one or more curved ramps 810. These curved ramps 810 can be formed on an outer surface of the first annular structure 808. In the illustrated embodiment, the one or more curved ramps 810 can be sized to abut the sidewall 804 of the housing 802. This positioning can allow the curved ramps 810 to direct fluid within the centrifugal chamber 806. The specific design and configuration of the first annular structure 808 and the curved ramps 810 can vary, providing flexibility in how the fluid is directed within the centrifugal chamber 806.

In some implementations, the oil separator 800 includes a second annular structure 812. This second annular structure 812 can be positioned within the first annular structure 808. The positioning of the second annular structure 812 within the first annular structure 808 can create a fluid channel between the two structures. The fluid channel can be used to further direct and control the flow of fluid within the centrifugal chamber 806.

In the illustrated embodiment, the second annular structure 812 can include one or more protrusions 814. These protrusions 814 can be designed as one or more annular rings. The annular rings can be sized and positioned to interact with the fluid within the fluid channel. The interaction between the annular rings and the fluid can influence the flow characteristics of the fluid, such as the Reynolds number. The Reynolds number can be increased or decreased depending on the specific design and configuration of the annular rings. The specific design and configuration of the second annular structure 812 and the protrusions 814 can vary, providing flexibility in how the fluid is directed and controlled within the centrifugal chamber 806. By adjusting the radii of the protrusions 814, the Reynolds number within the fluid channel can be controlled, which can in turn influence the flow characteristics of the fluid within the centrifugal chamber 806. This can provide a level of control over the fluid flow that can be adjusted to meet specific requirements of the oil separation process.

In some implementations, the design of the one or more curved ramps 810 on the first annular structure 808 can vary. For instance, the curvature of the ramps 810 can be adjusted to influence the direction and speed of the fluid within the centrifugal chamber 806. The ramps 810 can be designed with a steeper or shallower curvature, depending on the specific requirements of the oil separation process. The ramps 810 can also be spaced at different intervals around the outer surface of the first annular structure 808, providing further control over the fluid flow within the centrifugal chamber 806.

Turning to FIG. 9, an example oil separator is illustrated. The oil separator 900 of the illustrated embodiment includes a housing 902, a sidewall 904, a centrifugal chamber 906, and an oil outlet 908. In some implementations, the housing 902 can be cylindrical in shape, with the sidewall 904 forming the outer circumference of the cylinder. The centrifugal chamber 906 can occupy the interior space of the housing 902, providing a volume for the gas-oil mixture to undergo separation. In the illustrated embodiment, the oil outlet 908 can be positioned at a lower portion of the sidewall 904. This positioning can allow for efficient removal of separated oil. The oil outlet 908 can be connected to an external oil collection system (not shown) to facilitate the removal of the separated oil.

Turning to FIG. 10, an example oil separator 1000 is illustrated. In the illustrated embodiment, the oil separator 1000 includes a housing 1002 with a sidewall 1004. The housing 1002 can be designed to contain and facilitate the oil separation process. The sidewall 1004 can form the outer boundary of the oil separator 1000.

In some implementations, the housing 1002 includes a centrifugal chamber 1006. In the illustrated embodiment, an oil outlet 1008 extends through the sidewall 1004. This outlet 1008 can provide a path for the separated oil to exit the centrifugal chamber 1006. The positioning of the oil outlet 1008 through the sidewall 1004 can allow for efficient removal of the separated oil from the centrifugal chamber 1006.

In some implementations, the oil outlet 1008 is coupled to a solenoid 1010. In some examples, the solenoid 1010 is a pressure reduce solenoid valve. The solenoid 1010 can control the flow of oil from the centrifugal chamber 1006, allowing for automated or controlled oil removal based on pressure differentials.

In the illustrated embodiment, the oil separator 1000 includes an oil reservoir 1012 that is fluidly coupled to the oil outlet 1008 via the solenoid 1010. The oil reservoir 1012 serves as a collection point for the separated oil. The oil reservoir 1012 includes a vent 1014, which can be in the form of vent piping. This vent 1014 can allow for pressure equalization within the reservoir 1012.

In some implementations, the oil reservoir 1012 also includes an oil supply line 1016. This supply line 1016 can be used to transfer the collected oil from the reservoir 1012 to other systems as needed.

In the illustrated embodiment, both the oil reservoir 1012 and the housing 1002 can include an oil level sensor 1018 (e.g., an oil level switch). The oil level sensor 1018 is coupled to the housing 1002 at a height to monitor the oil level within the housing 1002. For example, if the aperture 256 becomes clogged or the oil supply solenoid valve 1010 malfunctions, the oil level will rise and the oil level sensor 1018 can sound an alarm or shut down the system to mitigate further damage. In a similar manner, the oil level sensor 1018 coupled to the oil reservoir 1012 is coupled at a height to monitor the level of oil within the oil reservoir 1012. For example, if the oil level within the oil reservoir 1012 gets too low, the oil level sensor can sound an alarm or shut down the system to mitigate further damage.

Referring now to FIG. 11, a flowchart of a process 1100 for operating an oil separator in a refrigeration system is illustrated, according to an exemplary embodiment. Process 1100 is shown to include receiving, by a fluid inlet of the oil separator, an amount of a fluid from a compressor, the fluid including coolant and oil (step 1102). For example, the oil separator 200 includes the fluid inlet 218 positioned on the sidewall 214 adjacent the first end 202. The fluid inlet 218 is fluidly coupled to the compressors (e.g., MT compressors 14 and/or LT compressors 24) and configured to receive a fluid output (e.g., CO₂ discharge gas) from the compressors. The fluid output includes coolant and oil. The fluid inlet 218 directs the fluid output into the centrifugal chamber 216 to begin the oil separation process.

Process 1100 is shown to include directing, by a first fluid channel of the oil separator, the fluid in a first vertical direction (step 1104). For example, the first annular structure 226 can include a diameter that is smaller than a diameter of the housing 200 to enable the first annular structure 226 to be positioned within the centrifugal chamber 216 to define a fluid path 227 between the first annular structure 226 and the inner surface of the sidewall 214. During operation, fluid is input into the centrifugal chamber 216 via the fluid inlet 218 and centrifugal force directs the fluid downward in the configuration of FIG. 2A along the fluid path 227.

Process 1100 is shown to include directing, by a second fluid channel of the oil separator, the fluid in a second vertical direction (step 1106). For example, during operation, fluid is input into the centrifugal chamber 216 via the fluid inlet 218 and centrifugal force directs the fluid downward in the configuration of FIG. 2A along the fluid path 227. The fluid is then directed upward in the configuration of FIG. 2A into the fluid channel 240.

Process 1100 is shown to include adjusting a turbulence of a flow of the fluid with one or more annular protrusions within the second fluid channel (step 1108). For example, during operation, fluid is input into the centrifugal chamber 216 via the fluid inlet 218 and centrifugal force directs the fluid downward in the configuration of FIG. 2A along the fluid path 227. The fluid is then directed upward in the configuration of FIG. 2A into the fluid channel 240. While the fluid is moving upward in the fluid channel 240, the one or more first protrusions 242 modulate the fluid between laminar and turbulent flow (e.g., modulate a Reynolds number within the fluid channel 240). Increasing or decreasing the Reynolds number refers to altering the factors that influence fluid flow characteristics. To increase the Reynolds number, one can increase the fluid's velocity, increase the characteristic linear dimension (e.g., pipe diameter), increase the fluid's density, or decrease the fluid's dynamic viscosity. Conversely, decreasing the Reynolds number involves the opposite actions: reducing velocity or characteristic dimension, decreasing density, or increasing viscosity. A higher Reynolds number typically indicates more turbulent flow, characterized by irregular fluctuations and mixing within the fluid. Lower Reynolds numbers are associated with more laminar flow, where fluid particles move in smooth layers with minimal mixing between layers.

Process 1100 is shown to include filtering, by a filtering element fluidly coupled to the second fluid channel, the oil from the coolant (step 1110). For example, the fluid output (e.g., the CO₂ discharge gas) from the compressor comprises oil and a refrigerant (e.g., the CO₂ refrigerant). The filter 224 is configured to separate the oil from the refrigerant and direct the oil towards the oil outlet 222 positioned adjacent the second end 208 of the housing 201. While the fluid interacts with the filter 224, oil is separated from the fluid and directed downward in the configuration of FIG. 2A towards the oil outlet 222 and the CO₂ refrigerant is directed upwards in the configuration of FIG. 2A towards the coolant outlet 220. The filter 224 is configured to separate the oil from the coolant and direct the coolant towards the coolant outlet 220 positioned adjacent the first end 202 of the housing 201.

Process 1100 is shown to include directing at least a portion of the oil in the first vertical direction towards an oil outlet (step 1112). For example, the fluid output (e.g., the CO₂ discharge gas) from the compressor comprises oil and a refrigerant (e.g., the CO₂ refrigerant).

The filter 224 is configured to separate the oil from the refrigerant and direct the oil towards the oil outlet 222 positioned adjacent the second end 208 of the housing 201. While the fluid interacts with the filter 224, oil is separated from the fluid and directed downward in the configuration of FIG. 2A towards the oil outlet 222 and the CO₂ refrigerant is directed upwards in the configuration of FIG. 2A towards the coolant outlet 220. The filter 224 is configured to separate the oil from the coolant and direct the coolant towards the coolant outlet 220 positioned adjacent the first end 202 of the housing 201.

Process 1100 is shown to include directing the coolant in the second vertical direction towards a coolant outlet (step 1114). For example, the fluid output (e.g., the CO₂ discharge gas) from the compressor comprises oil and a refrigerant (e.g., the CO₂ refrigerant). The filter 224 is configured to separate the oil from the refrigerant and direct the oil towards the oil outlet 222 positioned adjacent the second end 208 of the housing 201. While the fluid interacts with the filter 224, oil is separated from the fluid and directed downward in the configuration of FIG. 2A towards the oil outlet 222 and the CO₂ refrigerant is directed upwards in the configuration of FIG. 2A towards the coolant outlet 220. The filter 224 is configured to separate the oil from the coolant and direct the coolant towards the coolant outlet 220 positioned adjacent the first end 202 of the housing 201.

The process 1100 can be modified to include one or more steps in addition to those discussed above in connection with FIG. 11. The process 1100 can also be modified to remove and/or adjust the steps discussed above in connection with FIG. 11.

FIG. 12 shows a schematic drawing of a control system 1200 that can be used according to the present disclosure. In some implementations, the control system 1200 can be incorporated into a system level control device that is configured to operate any or all other components of the system such as the evaporator, the compressor, the gas cooler, the receiver, and the expansion valve. For example, the control system 1200 can be configured to operate the MT evaporators 12. The control system 1200 can be configured to operate the LT evaporators 22. The control system 1200 can be configured to operate the MT compressors 14. The control system 1200 can be configured to operate the LT compressors 24. The control system 1200 can be configured to operate the gas cooler/condenser 2. The control system 1200 can be configured to operate the receiving tank 6. The control system 1200 can be configured to operate the expansion valves 11. The control system 1200 can be configured to operate the oil separator 26. For example, all or parts of the control system (or controller) 1200 can be used for the operations described previously. The control system 1200 is intended to include various forms of digital computers, such as printed circuit boards (PCB), processors, digital circuitry, or otherwise. Additionally, the system can include portable storage media, such as, Universal Serial Bus (USB) flash drives. For example, the USB flash drives can store operating systems and other applications. The USB flash drives can include input/output components, such as a wireless transmitter or USB connector that can be inserted into a USB port of another computing device.

The control system 1200 includes a processor 1210, a memory 1220, a storage device 1230, and an input/output device 1240. Each of the components 1210, 1220, 1230, and 1240 are interconnected using a system bus 1250. The processor 1210 is capable of processing instructions for execution within the control system 1200. The processor 1210 can be designed using any of a number of architectures. For example, the processor 1210 can be a CISC (Complex Instruction Set Computers) processor, a RISC (Reduced Instruction Set Computer) processor, or a MISC (Minimal Instruction Set Computer) processor.

In one implementation, the processor 1210 is a single-threaded processor. In another implementation, the processor 1210 is a multi-threaded processor. The processor 1210 is capable of processing instructions stored in the memory 1220 or on the storage device 1230 to display graphical information for a user interface on the input/output device 1240.

The memory 1220 stores information within the control system 1200. In one implementation, the memory 1220 is a computer-readable medium. In one implementation, the memory 1220 is a volatile memory unit. In another implementation, the memory 1220 is a non-volatile memory unit.

The storage device 1230 is capable of providing mass storage for the control system 1200. In one implementation, the storage device 1230 is a computer-readable medium. In various different implementations, the storage device 1230 can be a floppy disk device, a hard disk device, an optical disk device, a tape device, flash memory, a solid state device (SSD), or a combination thereof.

The input/output device 1240 provides input/output operations for the control system 1200. In one implementation, the input/output device 1240 includes a keyboard and/or pointing device. In another implementation, the input/output device 1240 includes a display unit for displaying graphical user interfaces.

The features described can be implemented in digital electronic circuitry, or in computer hardware, firmware, software, or in combinations of them. The apparatus can be implemented in a computer program product tangibly embodied in an information carrier, for example, in a machine-readable storage device for execution by a programmable processor; and method steps can be performed by a programmable processor executing a program of instructions to perform functions of the described implementations by operating on input data and generating output. The described features can be implemented advantageously in one or more computer programs that are executable on a programmable system including at least one programmable processor coupled to receive data and instructions from, and to transmit data and instructions to, a data storage system, at least one input device, and at least one output device. A computer program is a set of instructions that can be used, directly or indirectly, in a computer to perform a certain activity or bring about a certain result. A computer program can be written in any form of programming language, including compiled or interpreted languages, and it can be deployed in any form, including as a stand-alone program or as a module, component, subroutine, or other unit suitable for use in a computing environment.

Suitable processors for the execution of a program of instructions include, by way of example, both general and special purpose microprocessors, and the sole processor or one of multiple processors of any kind of computer. Generally, a processor will receive instructions and data from a read-only memory or a random access memory or both. The essential elements of a computer are a processor for executing instructions and one or more memories for storing instructions and data. Generally, a computer will also include, or be operatively coupled to communicate with, one or more mass storage devices for storing data files; such devices include magnetic disks, such as internal hard disks and removable disks; magneto-optical disks; and optical disks. Storage devices suitable for tangibly embodying computer program instructions and data include all forms of non-volatile memory, including by way of example semiconductor memory devices, such as EPROM, EEPROM, solid state drives (SSDs), and flash memory devices; magnetic disks such as internal hard disks and removable disks; magneto-optical disks; and CD-ROM and DVD-ROM disks. The processor and the memory can be supplemented by, or incorporated in, ASICs (application-specific integrated circuits).

To provide for interaction with a user, the features can be implemented on a computer having a display device such as a CRT (cathode ray tube) or LCD (liquid crystal display) or LED (light-emitting diode) monitor for displaying information to the user and a keyboard and a pointing device such as a mouse or a trackball by which the user can provide input to the computer. Additionally, such activities can be implemented via touchscreen flat-panel displays and other appropriate mechanisms.

The features can be implemented in a control system that includes a back-end component, such as a data server, or that includes a middleware component, such as an application server or an Internet server, or that includes a front-end component, such as a client computer having a graphical user interface or an Internet browser, or any combination of them. The components of the system can be connected by any form or medium of digital data communication such as a communication network. Examples of communication networks include a local area network (“LAN”), a wide area network (“WAN”), peer-to-peer networks (having ad-hoc or static members), grid computing infrastructures, and the Internet.

While this specification contains many specific implementation details, these should not be construed as limitations on the scope of any inventions or of what can be claimed, but rather as descriptions of features specific to particular implementations of particular inventions. Certain features that are described in this specification in the context of separate implementations can also be implemented in combination in a single implementation. Conversely, various features that are described in the context of a single implementation can also be implemented in multiple implementations separately or in any suitable subcombination. Moreover, although features can be described above as acting in certain combinations and even initially claimed as such, one or more features from a claimed combination can in some cases be excised from the combination, and the claimed combination can be directed to a subcombination or variation of a subcombination.

Similarly, while operations are depicted in the drawings in a particular order, this should not be understood as requiring that such operations be performed in the particular order shown or in sequential order, or that all illustrated operations be performed, to achieve desirable results. In certain circumstances, multitasking and parallel processing can be advantageous. Moreover, the separation of various system components in the implementations described above should not be understood as requiring such separation in all implementations, and it should be understood that the described program components and systems can generally be integrated together in a single software product or packaged into multiple software products.

A number of implementations have been described. Nevertheless, it will be understood that various modifications can be made without departing from the spirit and scope of the disclosure. For example, example operations, methods, or processes described herein can include more steps or fewer steps than those described. Further, the steps in such example operations, methods, or processes can be performed in different successions than that described or illustrated in the figures. Accordingly, other implementations are within the scope of the following claims.