APPARATUS AND METHOD FOR MODULATING HEATING OR COOLING CAPACITY OF A CLIMATE CONTROL SYSTEM WITH MULTIPLE REFRIGERANTS

Description

FIELD

The field of the present disclosure relates to climate control systems for use with working fluids having refrigerant blends exhibiting high glide and methods for operating the same, and more specifically to climate control systems having a liquid-to-suction heat exchanger, a heat exchanger, an accumulator, and a receiver for controlling refrigerant concentrations.

BACKGROUND

The background description provided herein is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.

A thermodynamic climate control system such as, a heat-pump system, a refrigeration system, or an air conditioning system may include a fluid circuit having a first heat exchanger (e.g., a condenser that facilitates a phase change of refrigerant from gas/vapor to a liquid) that is typically located outdoors, a second heat exchanger (e.g., an evaporator that facilitates a phase change of refrigerant from liquid to gas/vapor) that is typically located indoors or within the environment to be cooled, a receiver that operates to store liquid refrigerant between the first and second heat exchangers (e.g., condenser and evaporator), an accumulator that operates to store liquid phase refrigerant upstream of the second heat exchangers (e.g., evaporator), a liquid pump disposed between the first and second heat exchangers, expansion devices disposed between the first heat exchanger (e.g., condenser) and the receiver and between the receiver and the second heat exchanger (e.g., evaporator), and a compressor disposed between the first and second heat exchangers that operates to pressurize gas/vapor phase refrigerant.

These types of systems can be fixed, such as at a building or residence, or can be mobile, such as in, or as part of a vehicle. For example, vehicles include land based vehicles (e.g., trucks, cars, trains, etc.), water based vehicles (e.g., boats, sea containers), air based vehicles (e.g., airplanes), and vehicles that operate over a combination of more than one of land, water, and air.

There is growing pressure to adopt refrigerants with lower global warming potential (GWP) due to environmental concerns. Traditional synthetic refrigerants are being reconsidered in favor of natural refrigerants, which can offer a more eco-friendly alternative. The shift towards these natural refrigerants introduces new challenges which include device applicability, environmental acceptability and safety. While natural refrigerants present a promising solution to reduce environmental impact, their adoption requires careful management of these associated challenges.

Synthetic refrigerants may be replaced by natural refrigerants in some climate control applications. Further, in order to use lower global warming potential refrigerants, the flammability of the refrigerants may increase.

Several refrigerants have been developed that are considered low global warming potential options, and they have an ASHRAE (American Society of Heating, Refrigerating and Air-Conditioning Engineers) classification as A2 (relatively lower flammability than A3 refrigerants), A2L (mildly flammable/lower flammable than A2 and A3 refrigerants and lower toxicity), or A1 (no flame propagation/lower toxicity levels). Examples of an A2 refrigerant include 1,1-difluorethane (R-152A—as used herein, the refrigerants may be interchangeably described by the conventional nomenclature of “R” for refrigerants or their specific chemical class code, like HFC-152A) with a global warming potential of about 124, while examples of A2L refrigerants include difluoromethane (CH2F2 or R-32—as used herein, the refrigerants may be interchangeably described by the conventional nomenclature of “R” for refrigerants or their specific chemical class code, like HFC-32) with a global warming potential of about 677, and hydrofluorolefins (HFOs), like 2,3,3,3,-tetrafluoroprop-1-ene (HFO-1234yf or R-1234yf), trans-1,3,3,3,-tetrafluoroprop-1-ene (HFO-1234ze or R-1234ze). A1 refrigerants include carbon dioxide (CO₂ or R-744), which has a desirably low global warming potential of 1, 1-chloro-3,3,3-trifluoropropene (cis- and trans-HFO-1233zd(Z) or R-1233zd (Z) and HCFO-1233zd(E) or R-1233zd (E)), chlorodifluoromethane (R-22 or CHClF2), R-410A that is a near-azeotropic mixture of difluoromethane (HFC-32) and pentafluoroethane (HFC-125), and other hydrocarbon refrigerants, such as hexane, heptane, octane, nonane, and decane..

It would be desirable to employ climate control systems that can successfully employ such environmentally friendly refrigerants with low global warming potential.

SUMMARY

In a feature, a climate control system includes: a working fluid comprising a blend of a first refrigerant and a second refrigerant; an accumulator; a compressor that receives the working fluid from the accumulator and compresses the working fluid; a first heat exchanger disposed downstream of the compressor; a liquid-to-suction heat exchanger disposed downstream of the first heat exchanger and upstream of a receiver; a first expansion valve disposed between the liquid-to-suction heat exchanger and the receiver; a second expansion valve disposed between the receiver and a second heat exchanger, the second heat exchanger, where the second heat exchanger receives the working fluid from the second expansion valve and at least partially vaporizes the working fluid and outputs the at least partially vaporized working fluid to the liquid-to-suction heat exchanger; and a control module configured to selectively adjust opening of at least one of the first expansion valve and the second expansion valve based on (a) decreasing capacity and increasing working fluid concentration and (b) increasing capacity and decreasing working fluid concentration.

In a feature, a thermostat is configured to measure a temperature of a space, where the control module is configured to, based on the temperature, selectively adjust the opening of at least one of the first expansion valve and the second expansion valve based on (a) decreasing capacity and increasing working fluid concentration and (b) increasing capacity and decreasing working fluid concentration.

In further features, the control module is configured to determine a difference between the temperature and a setpoint temperature, where the control module is configured to, based on the difference, selectively adjust the opening of at least one of the first expansion valve and the second expansion valve based on (a) decreasing capacity and increasing working fluid concentration and (b) increasing capacity and decreasing working fluid concentration.

In further features, the control module is configured to determine a difference between a target concentration and a concentration of the second refrigerant determined based on operating parameters of the climate control system, where the control module is configured to, based on the difference, selectively adjust the opening of at least one of the first expansion valve and the second expansion valve based on (a) decreasing capacity and increasing working fluid concentration and (b) increasing capacity and decreasing working fluid concentration.

In further features, the control module is configured to close the second expansion valve and modulate the first expansion valve based on decreasing capacity by increasing working fluid concentration of the second refrigerant circulating the system.

In further features, the control module is configured to open the second expansion valve and modulate the first expansion valve based on increasing capacity by decreasing working fluid concentration of the second refrigerant circulating the system.

In further features, the control module is further configured to maintain capacity by modulating the openings of the first and second expansion valves based on maintaining the working fluid concentration.

In further features, the control module is configured to close the second expansion valve to at least one of (a) increase the subcooling and (b) decrease the vapor quality leaving the condenser and modulate opening of the first expansion valve.

In further features, the control module is configured to close the second expansion valve and modulate opening of the first expansion valve based on a predetermined target concentration of the working fluid.

In further features, the control module is configured to modulate the first expansion valve by adjusting characteristic of a signal applied to the first expansion valve.

In a feature, a climate control method includes: by a compressor, receiving a working fluid from an accumulator and compressing the working fluid, where the working fluid comprises a blend of a first refrigerant and a second refrigerant; by a first heat exchanger, receiving the working fluid from the compressor; by a liquid-to-suction heat exchanger, receiving the working fluid from the first heat exchanger and outputting the working fluid toward a receiver; by a first expansion valve, receiving the working fluid from the liquid-to-suction heat exchanger and outputting the working fluid to the receiver; by a second expansion valve, receiving the working fluid from the receiver and outputting the working fluid toward a second heat exchanger, where the second heat exchanger at least partially vaporizes the working fluid and outputs the at least partially vaporized working fluid to the liquid-to-suction heat exchanger; and selectively adjusting opening of at least one of the first expansion valve and the second expansion valve based on (a) decreasing capacity and increasing working fluid concentration and (b) increasing capacity and decreasing working fluid concentration.

In further features, the method further includes: by a thermostat measuring a temperature of a space, and based on the temperature, selectively adjust the opening of at least one of the first expansion valve and the second expansion valve based on (a) decreasing capacity and increasing working fluid concentration and (b) increasing capacity and decreasing working fluid concentration.

In further features, the method further includes: determining a difference between the temperature and a setpoint temperature; and based on the difference, selectively adjust the opening of at least one of the first expansion valve and the second expansion valve based on (a) decreasing capacity and increasing working fluid concentration and (b) increasing capacity and decreasing working fluid concentration.

In further features, the method further includes: determining a difference between a target concentration and a concentration of the second refrigerant determined based on operating parameters of the climate control system; and based on the difference, selectively adjust the opening of at least one of the first expansion valve and the second expansion valve based on (a) decreasing capacity and increasing working fluid concentration and (b) increasing capacity and decreasing working fluid concentration.

In further features, the method further includes closing the second expansion valve and modulating the first expansion valve based on decreasing capacity by increasing working fluid concentration of the second refrigerant circulating the system.

In further features, the method further includes opening the second expansion valve and modulating the first expansion valve based on increasing capacity by decreasing working fluid concentration of the second refrigerant circulating the system.

In further features, the method further includes maintaining capacity by modulating the openings of the first and second expansion valves based on maintaining the working fluid concentration.

In further features, the method further includes closing the second expansion valve to at least one of (a) increase the subcooling and (b) decrease the vapor quality leaving the condenser and modulate opening of the first expansion valve.

In further features, the method further includes closing the second expansion valve and modulating opening of the first expansion valve based on a predetermined target concentration of the working fluid.

In further features, the method further includes modulating the first expansion valve by adjusting characteristic of a signal applied to the first expansion valve.

In a feature, a climate control system includes: a working fluid comprising a blend of a first refrigerant and a second refrigerant; a flash tank that receives the working fluid and separates vapor phase working fluid from liquid phase working fluid; a compressor that receives the vapor phase refrigerant from the flash tank and compresses the vapor phase working fluid; a pump that receives the liquid phase working fluid from the flash tank and that pumps the liquid phase working fluid to a first heat exchanger; the first heat exchanger, wherein the first heat exchanger is disposed downstream of the compressor and the pump that generates multiphase working fluid from the vapor phase refrigerant from the compressor and the liquid phase refrigerant from the pump; a liquid-to-suction heat exchanger disposed downstream of the first heat exchanger and upstream of a second heat exchanger; the second heat exchanger, where the second heat exchanger receives the multiphase working fluid from the liquid-to-suction heat exchanger and at least partially vaporizes the multiphase working fluid and outputs the at least partially vaporized multiphase working fluid to the liquid-to-suction heat exchanger; and a control module configured to selectively adjust a speed of the pump based on (a) decreasing capacity and increasing working fluid concentration and (b) increasing capacity and decreasing working fluid concentration.

In further features, a thermostat is configured to measure a temperature of a space, where the control module is configured to, based on the temperature, selectively adjust the opening of at least one of the first expansion valve and the second expansion valve based on (a) decreasing capacity and increasing working fluid concentration and (b) increasing capacity and decreasing working fluid concentration.

In further features, the control module is configured to determine a difference between the temperature and a setpoint temperature, where the control module is configured to, based on the difference, selectively adjust the opening of at least one of the first expansion valve and the second expansion valve based on (a) decreasing capacity and increasing working fluid concentration and (b) increasing capacity and decreasing working fluid concentration.

In further features, the control module is configured to receive the setpoint temperature from the thermostat.

In further features, the control module is configured to increase the speed of the pump based on increasing the concentration of the working fluid and decreasing capacity.

In further features, the control module is configured to increase the speed of the pump when a difference between a temperature of the space and a setpoint temperature of the space is greater than a predetermined temperature.

In further features, the control module is configured to decrease the speed of the pump based on decreasing concentration of the working fluid and increasing capacity.

In further features, the control module is configured to decrease the speed of the pump when a difference between a temperature of the space and a setpoint temperature of the space is less than a predetermined temperature.

In further features, the control module is configured to maintain the speed of the pump to maintain concentration of the working fluid.

In further features, the control module is configured to adjust the speed of the pump based on a target concentration of the working fluid.

In a feature, a climate control method includes: by a flash tank, receiving a working fluid and separating vapor phase working fluid from liquid phase working fluid, where the working fluid includes a blend of a first refrigerant and a second refrigerant; by a compressor, receiving the vapor phase refrigerant from the flash tank and compressing the vapor phase working fluid; by a pump, receiving the liquid phase working fluid from the flash tank and pumping the liquid phase working fluid to a first heat exchanger; where the first heat exchanger generates multiphase working fluid from the vapor phase refrigerant from the compressor and the liquid phase refrigerant from the pump; by a liquid-to-suction heat exchanger, receiving the working fluid from the first heat exchanger and outputting the working fluid to a second heat exchanger; by the second heat exchanger receiving the multiphase working fluid from the liquid-to-suction heat exchanger and at least partially vaporizing the multiphase working fluid and outputting the at least partially vaporized multiphase working fluid to the liquid-to-suction heat exchanger; and selectively adjusting a speed of the pump based on (a) decreasing capacity and increasing working fluid concentration and (b) increasing capacity and decreasing working fluid concentration.

In further features, the method further includes by a thermostat measuring a temperature of a space, and based on the temperature, selectively adjusting the opening of at least one of the first expansion valve and the second expansion valve based on (a) decreasing capacity and increasing working fluid concentration and (b) increasing capacity and decreasing working fluid concentration.

In further features, the method further includes determining a difference between the temperature and a setpoint temperature, and based on the difference, selectively adjusting the opening of at least one of the first expansion valve and the second expansion valve based on (a) decreasing capacity and increasing working fluid concentration and (b) increasing capacity and decreasing working fluid concentration.

In further features, the method further includes receiving the setpoint temperature from the thermostat.

In further features, the method further includes increasing the speed of the pump based on increasing the concentration of the working fluid and decreasing capacity.

In further features, the method further includes increasing the speed of the pump when a difference between a temperature of the space and a setpoint temperature of the space is greater than a predetermined temperature.

In further features, the method further includes decreasing the speed of the pump based on decreasing concentration of the working fluid and increasing capacity.

In further features, the method further includes decreasing the speed of the pump when a difference between a temperature of the space and a setpoint temperature of the space is less than a predetermined temperature.

In further features, the method further includes maintaining the speed of the pump to maintain concentration of the working fluid.

In further features, the method further includes adjusting the speed of the pump based on a target concentration of the working fluid.

Further areas of applicability of the present disclosure will become apparent from the detailed description, the claims and the drawings. The detailed description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure will become more fully understood from the detailed description and the accompanying drawings, wherein:

FIG. 1 is a functional block diagram of an example refrigeration system;

FIG. 2 is a functional block diagram of an alternative example refrigeration system;

FIG. 3 is a functional block diagram of a control module of a refrigeration system;

FIG. 4 is a method for achieving a target concentration of a refrigeration system;

FIG. 5 is a method for achieving a target concentration of a refrigeration system by adjusting the expansion valves; and

FIG. 6 is a method for achieving a target concentration of a refrigeration system by adjusting the speed of a pump.

In the drawings, reference numbers may be reused to identify similar and/or identical elements.

DETAILED DESCRIPTION

Referring now to FIG. 1, a functional block diagram of an example of a climate control system 120. The climate control system 120 includes an evaporator, a condenser, a compressor, an accumulator, a liquid-to-suction heat exchanger, a receiver, and at least one expansion valve, which as described herein provides the capability of taking advantage of the high glide refrigerant blend in the working fluid.

The evaporator receives and at least partially vaporizes the low-pressure multiphase working fluid. The working fluid in this example includes refrigerant. Thus, the terms refrigerant and working fluid may be used interchangeably within this disclosure. One or more other fluids may also be provided, however, such as lubricant, additive, etc. The condenser receives, cools, and condenses the refrigerant blend. The compressor compresses a vapor stream and forms a high-pressure vapor stream. The accumulator and the receiver store or hold liquid phase refrigerant(s). The liquid-to-suction heat exchanger transfers heat between the relatively hot refrigerant on one side and colder biphasic refrigerant on the other side. The expansion valve modulates flow and reduces pressure.

For example, in the climate control system, the refrigerant blend in the working fluid is processed by adjusting the expansion valves. Additionally, the climate control system provides an ability to change refrigerant blend by varying the mass of liquid refrigerant in an accumulator and a receiver (or other vessels). Further, superheating and sub-cooling the working fluid stream approaching the compressor is used to intentionally drive changes in a level of select refrigerants in the accumulator. To lower the level of liquid in a receiver, a condenser and liquid-suction heat exchanger bypass for discharge gas/vapor may be used. Alternatively, permitting higher subcooling at the entrance or inlet to the receiver will raise the level in the receiver. As such, the levels of liquid in the accumulator and receiver may be adjusted by the adjusting of the expansion valves. In other variations, a liquid bypass may be used to direct at least a portion of liquid of the refrigerant blend into the accumulator and thus avoiding the evaporator and liquid-to-suction heat exchanger.

By way of example, FIG. 1 shows a functional block diagram of an example of the climate control system 120, such as a refrigeration system, that processes and circulates a working fluid including at least a first refrigerant (A) and a second refrigerant (B) that together exhibit glide. The capacity of the climate control system 120 may be modulated by changing relative proportions of the first refrigerant (A) and the second refrigerant (B) in the working fluid blend at different points in the system. The climate control system 120 changes relative proportions of the first refrigerant (A) and the second refrigerant (B) by adjusting the expansion valves.

Therefore, the resulting density of the compressor suction is modified by preferentially storing concentrated amounts of the first refrigerant (A) or the second refrigerant (B) in one or more select regions of the system. In various implementations, the present disclosure provides a climate control system that may be configured to incompletely evaporate and condense refrigerant.

As discussed above, two or more refrigerants may be present, but for simplicity, two refrigerants are used in this example and a difference in boiling points between the first refrigerant (A) and the second refrigerant (B) is greater than or equal to about 25° R. at atmospheric pressure. The working fluid may also include oil(s) at certain points in the system. The term “fluid” as used herein may encompass liquid, gas, and any combination thereof, including vapor (e.g., a gas phase having aerosolized liquid droplets). The term gas or gas phase as used herein may encompass both vapor and pure gas phases.

The climate control system 120 has a fluid flow path or fluid conduit 122 that establishes fluid communication between the various components, so that the working fluid may circulate in a loop as discussed further herein. First, the working fluid including the first refrigerant (A) and the second refrigerant (B) may enter a first heat exchanger such as an evaporator 140. The evaporator 140 causes the first refrigerant (A) and/or the second refrigerant (B) to transform from a liquid phase to a gas or vapor phase as it exits the evaporator 140 at point 230, where the cooling effect of endothermic energy absorption occurs.

The refrigerant(s) may evaporate at a lower pressure withdrawing heat from the surrounding zone. Air flowing through the evaporator 140 is shown by arrows, where the air is cooled. As shown, the air flows in a countercurrent arrangement, although concurrent or other air flow configurations may also be used. The heat exchangers (evaporator 140 and condenser 162 discussed below) may include concentric, finned tube, brazed plate, plate, and frame, microchannel, or other heat exchangers. There may be a single evaporator and condenser or multiple evaporators and/or condensers in parallel or series configurations. Refrigerant flow therein can be controlled via a capillary tube, thermostatic expansion valve, electric expansion valve, or other methods. In heat pump systems, the roles of the evaporator 140 and the condenser 162 may be reversed during operation using a reversing valve based on whether heating or cooling of a space is being performed.

The evaporator 140 may be located in a space to be cooled by the climate control system 120 or used to cool air flowing into a space in which cooling is desired. The evaporator 140 receives and at least partially vaporizes the low-pressure multiphase working fluid at point 239 and directs the working fluid after point 230 to a downstream liquid-to-suction heat exchanger 142. More specifically, the low-pressure multiphase working fluid passes in a first flow direction indicated by the arrow within a first side 142A of the liquid-to-suction heat exchanger 142.

At point 230, in the fluid conduit 122, the working fluid includes a combination of both the first refrigerant (A) and the second refrigerant (B) that are partially or fully in gas phase. The working fluid at point 230 may be multiphase including liquid and gas. As noted above, the working fluid having the refrigerant blend with the first refrigerant (A) and the second refrigerant (B) may only be partially evaporated to form a mixture of both gas/vapor and liquid. For example, the first refrigerant (A) may have a lower boiling point/lower critical point and may be more volatile, so a greater amount of first refrigerant (A) volatizes or evaporates. The second refrigerant (B) has a higher boiling point/higher critical point and thus a lower proportion of second refrigerant (B) evaporates or volatilizes in the working fluid and thus a larger proportion remains in liquid form. By way of example, the vapor quality, or mass fraction of vapor of the working fluid at point 230 that exits the evaporator 140 may be, for example from greater than or equal to about 15% to about 100% vapor quality depending on an amount of liquid evaporated.

A portion of the working fluid in the fluid conduit 122 at point 230 may include the second refrigerant (B) in liquid form. The working fluid passes into the first side 142A of the liquid-to-suction heat exchanger 142 in a first flow direction, and the liquid-to-suction heat exchanger 142 transfers heat with a distinct stream of the working fluid passing in a second flow direction of a second side 142B of the liquid-to-suction heat exchanger 142. The first flow direction and the second flow direction of the streams of working fluid within the liquid-to-suction heat exchanger 142 may be in a counter-current heat transfer relationship, co-current heat transfer relationship, or in another suitable heat transfer relationship.

Generally, the liquid-to-suction heat exchanger 142 transfers heat between the relatively hot working fluid exiting the condenser 162 and colder working fluid exiting the evaporator 140. The hotter working fluid can increase the temperature and vapor quality of the stream exiting from the evaporator 140 in the liquid-to-suction heat exchanger 142 such as to provide a higher level of sub-cooling (or a lower temperature and lower vapor quality) of the working fluid flowing from the condenser to increase the evaporator capacity. Thus, the liquid-to-suction heat exchanger 142 can provide advantages such as further cooling the liquid refrigerant prior to it entering the evaporator 140, which can increase system efficiency and can reduce possible flashing in the liquid line. In this manner, the partially evaporated refrigerant flowing from the evaporator is further evaporated by heat transfer with warmer partially condensed (or performs subcooling of) refrigerant flowing from the condenser. Further, the liquid-to-suction heat exchanger 142 does not superheat the suction gas in certain variations.

In certain aspects, an amount of heat transferred by the liquid-to-suction heat exchanger 142 maybe expressed by a difference in temperature (ΔT) between a first temperature (T1) of the working fluid at point 236 and a second temperature (T2) of the working fluid at point 230.

The heating of the working fluid exiting the liquid-to-suction heat exchanger 142 adjusts to a superheated level that is either positive or negative as it enters an accumulator 144.

After exiting the first side 142A of the liquid-to-suction heat exchanger 142, the working fluid may be at near-saturated vapor conditions and enters a storage vessel or tank in the form of the accumulator 144 that receives the working fluid that may include the working fluid in both a vapor and liquid phase. More specifically, the vapor phase of the working fluid in the accumulator 144 includes gas or vapor phase working fluid, including substantially more of the volatile/low critical point first refrigerant (A) and optionally, a portion of the less volatile/high critical point second refrigerant (B), depending on desired operating conditions. The liquid phase may include the second refrigerant (B) in a liquid phase, for example, in certain variations, a higher concentration of the liquid phase may be second refrigerant (B). As discussed below, the accumulator 144 stores or holds liquid phase refrigerant(s), while saturated vapor refrigerant(s) are returned to a compressor 150. In certain aspects, the accumulator 144 may be sized based on suction volume flow and by how much refrigerant may be stored therein.

A liquid level of the accumulator 144 can be adjusted, either by raising or lowering, as follows. Superheat can drive the change of level. For example, the heating of the working fluid exiting the liquid-to-suction heat exchanger adjusts the working fluid to have a superheated level that is either positive or negative as it enters the compressor and before it enters the condenser, where the superheated level adjusts a stored amount of liquid in the accumulator 144. With the high glide of the refrigerant, measurable negative superheat will describe a state where liquid is being added to the accumulator 144. Positive superheat will result in the boiling/evaporation of refrigerant from the accumulator 144 into the suction flow stream (e.g., at point 232) thus reducing the liquid stored in the accumulator.

The stream of working fluid exiting the accumulator 144 at point 232 may be predominantly or entirely in the vapor phase, and thus referred to as a vapor stream, that passes into the compressor 150 where it is compressed to increase pressure and form a high-pressure vapor or gas stream 234 exiting the compressor 150. The compressor 150 is controlled by the control module 602. The compressor 150 maybe for example, a positive displacement compressor, a dynamic compressor, or another type of compressor. Positive displacement compressors increase refrigerant vapor pressure by reducing the volume of the compression chamber through work applied to the compressor's mechanism. Positive displacement compressors include reciprocating, rotary (rolling position, rotary vane, single screw, twin screw), and orbital (scroll or trochoidal) compressors. Dynamic compressors increase refrigerant vapor pressure by transfer of kinetic energy of gas in a compression mechanism in the form of a rotating member, followed by conversion of this energy into a pressure rise. Centrifugal compressors function based on these principles. In certain variations, the compressor 150 may be a scroll compressor or a reciprocating compressor, by way of example. The gas stream 234 of the working fluid exiting the compressor has a pressure that is greater than the pressure of the vapor stream 232.

A high-pressure or pressurized gas stream 234 of the working fluid exiting the compressor 150 has a pressure that is significantly greater than the pressure of vapor stream 232. The mechanical energy for compressing the vapor and pumping the fluid in the compression mechanism of the compressor is provided by, for example, an electric motor or internal combustion engine.

The condenser 162 is disposed downstream of the compressor 150 and thus receives and cools the pressurized gas stream 134 at condenser inlet 160. The working fluid thus enters the inlet 160 of condenser 162 as a gas, which is partially or completely condensed to a near-saturated liquid as it exits the condenser 162 at point 236. The working fluid exits the condenser 162 as partially or completely condensed or a subcooled to a near-saturated liquid at point 236. The vapor quality, or mass fraction of vapor, of the working fluid (liquid stream at point 236) that exits the condenser 162 may be in an amount ranging from subcooled liquid to less than or equal to 25% vapor quality, such as 10% vapor quality, optionally 5% vapor quality, optionally 1% vapor quality, by way of non-limiting examples.

The condenser 162 transforms pressurized gas stream 234 and/or pressurized liquid stream from a gas phase to a liquid phase (for example, the first refrigerant (A) transforms from a gas to a liquid). The condenser 162 transfers heat from the working fluid to air passing the condenser 162. The condenser 162 may be located in a room or space where heat may be expelled, for example, outdoors. The working fluid having the refrigerant blend of the first refrigerant (A) and the second refrigerant (B) may be only partially condensed to form a multiphase mixture of both liquid and optionally gas/vapor.

After passing through the condenser 162, the working fluid is a high-pressure liquid stream 236. The high-pressure liquid stream 236 of working fluid passes into the second side 142B of the liquid-to-suction heat exchanger 142 in a second flow direction and heat will be transferred with the distinct stream of the working fluid passing in the first flow direction in the first side 142A of the liquid-to-suction heat exchanger 142. As shown, the second flow direction is indicated by an arrow and is in a countercurrent heat exchange configuration with the first flow direction. Thus, the working fluid exiting the condenser 162 may be a near-saturated or saturated liquid, which is completely condensed and subcooled, within the liquid-to-suction heat exchanger 142.

After exiting the second side 142B of the liquid-to-suction heat exchanger 142, the working fluid is a liquid condensate at point 238, which is then circulated in fluid conduit 122 through a first expansion device, such as a first expansion valve 146. The first expansion valve 146 is disposed between the liquid-to-suction heat exchanger 142 and a second storage vessel in the form of a receiver 148. The first expansion valve 146 is controlled by the control module 602. In certain aspects, the receiver 148 may be sized based on how much refrigerant may be stored therein. At the first expansion valve 146, the pressure of the working fluid is reduced. In this manner, the working fluid stream is subcooled in the liquid-to-suction heat exchanger 142 followed by a reduction in pressure as it passes through the first expansion valve 146.

The working fluid exiting the first expansion valve 146 then enters the receiver 148, where vapor and liquid are separated and liquid circulating through the system may be stored and concentrated. The receiver 148 receives the working fluid that may include the working fluid in both a vapor and liquid phase, however, it may be predominantly in a liquid phase. The working fluid continues along the path exiting through an outlet 149 as a saturated liquid.

After exiting receiver 148, the working fluid passes through a second expansion device, such as a second expansion valve 152. Actuation of the second expansion valve 152 is controlled by the control module 602. The second expansion valve 152 reduces pressure of the working fluid. The working fluid leaving the receiver 148 is further expanded to a two-phase working fluid as it passes through the second expansion valve 152.

The second expansion valve 152 is disposed between the receiver 148 and an inlet 141 to the evaporator 140. Thus, at point 239 the working fluid may be a low-pressure multiphase stream that then enters the evaporator 140 completing the refrigerant cycle. The working fluid then enters the evaporator 140, where it may be partially boiled to a higher vapor quality fluid. The higher vapor quality working fluid at point 230 is further boiled in the first side 142A of the liquid-to-suction heat exchanger 142, for example, to a near-saturated vapor condition working fluid. As discussed above, the near-saturated vapor condition working fluid stream is returned to the accumulator 144, where liquid phase refrigerant(s) are held or stored, while saturated vapor refrigerant(s) are returned to the compressor 150.

In some embodiments, the flow of air through the evaporator 140 and the condenser 162 may be low as the counterflow of gliding refrigerant in fluid conduit 122 reduces the impact that results from high temperature splits on the secondary fluid (air). The climate control system 120 may include one or more of the following not shown, such as flow rate sensors, pressure sensors, temperature sensors, actuators, etc.

The control module 602 controls the concentrations of respective refrigerants in a working fluid having high glide, by varying the mass of liquid refrigerant in an accumulator and a receiver by adjusting the first expansion valve 146 and the second expansion valve 152, the working fluid may be adjusted to have positive or negative superheat approaching the compressor to drive changes in the accumulator level.

Referring now to FIG. 2, a functional block diagram of an alternative example of the climate control system 120. The climate control system 120 includes an evaporator, a condenser, a compressor, a flash tank, a liquid pump, and a liquid-to-suction heat exchanger, which uses high glide refrigerant blend in the working fluid.

The flash tank separates the gas/vapor phase refrigerant from the liquid phase refrigerant. The liquid pump pumps the liquid phase refrigerant to a pressure for condensing and forming a higher pressure liquid stream. For example, in the climate control system the refrigerant blend is the working fluid and is being processed by modulating the speed of the liquid pump. As such, the climate control system includes the evaporator that receives and at least partially vaporizes the lower-pressure multiphase working fluid. The condenser receives and cools the refrigerant blend. The compressor compresses a vapor stream and forms a higher-pressure vapor stream.

A flash tank separates gas/vapor phase refrigerant from liquid phase refrigerant. The liquid phase refrigerant has a higher concentration of the higher critical temperature refrigerant and is pumped through the liquid pump to a pressure for condensing. The gas/vapor phase refrigerant has a lower concentration of the higher critical temperature refrigerant and is compressed to a pressure required for condensing.

The gas/vapor phase refrigerant and liquid phase refrigerant are mixed to form the refrigerant blend. The refrigerant blend includes a higher vapor quality 2-phase or a lower superheat vapor that would be delivered to the condenser to convert the vapor to liquid, either partially or completely. The refrigerant flowing from the outlet of the condenser exchanges heat with the refrigerant flowing from the outlet of the evaporator at the liquid-to-suction heat exchanger to sub-cool the liquid refrigerant from the condenser. The subcooled refrigerant is expanded to a lower temperature to absorb heat in the evaporator. In the evaporator, part of the liquid refrigerant is further evaporated (e.g., via boiling) in a region of relatively low glide. After the evaporator, the refrigerant faces most of the glide and is boiled in the heat exchange with the liquid leaving the condenser, after which the cycles repeats.

By way of example, FIG. 2 shows a functional block diagram of the example of the climate control system 120, such as a refrigeration system, that processes and circulates the working fluid including at least the first refrigerant (A) and the second refrigerant (B) that exhibit glide. The capacity of the climate control system 120 may be modified by changing a speed of the liquid pump 202.

The climate control system 120 has the fluid flow path or fluid conduit 122 that establishes fluid communication between the various components, so that the working fluid may circulate in a loop as described further herein. First, the working fluid including the first refrigerant (A) and the second refrigerant (B) may enter a first heat exchanger in the form of the evaporator 140. The evaporator 140 causes the first refrigerant (A) and/or second refrigerant (B) to transform from a liquid phase to a gas or vapor phase as it exits the evaporator 140 at point 230, with the cooling effect at a lower pressure withdrawing heat from the surrounding zone.

Air flowing through the evaporator 140, which is shown by arrows, is cooled. As shown, the air flows in a countercurrent arrangement, although concurrent or other air flow configurations may also be used.

The evaporator 140 receives and at least partially vaporizes the low-pressure multiphase working fluid at point 239 and directs the working fluid after point 230 to a downstream liquid-to-suction hear exchanger 142. More specifically, the low-pressure working fluid passes in a first flow direction indicated by the arrow within a first side 142A of the liquid-to-suction heat exchanger 142.

At point 230, in the fluid conduit 122, the working fluid includes a combination of both the first refrigerant (A) and the second refrigerant (B) that are partially or fully in gas phase. Working fluid at point 230 may be multiphase including liquid and gas. As noted above, the working fluid having the refrigerant blend with the first refrigerant (A) and the second refrigerant (B) may only be partially evaporated to form a mixture of both gas/vapor and liquid. For example, the first refrigerant (A) may have a lower boiling point/lower critical point, and is more volatile, so a greater amount of first refrigerant (A) volatizes or evaporates. The second refrigerant (B) has a higher boiling point/higher critical point and thus a lower proportion of second refrigerant (B) evaporates or volatilizes in the working fluid and thus a larger proportion remains in liquid form. By way of example, the vapor quality, or mass fraction of vapor of the working fluid at point 230 that exits the evaporator 140 may be, for example from greater than or equal to about 15% to about 100% vapor quality depending on an amount of liquid evaporated.

A portion of the working fluid in the fluid conduit 122 at point 230 may include the second refrigerant (B) in liquid form. The working fluid passes into the first side of 142A of the liquid-to-suction heat exchanger 142 in a first flow direction, and the liquid-to-suction heat exchanger 142 transfers heat with a distinct stream of the working fluid passing in a second flow direction of a second side 142B of the liquid-to-suction heat exchanger 142. The first flow direction and the second flow direction of the streams of working fluid within the liquid-to-suction heat exchanger 142 may be in a counter-current heat transfer relationship, co-current heat transfer relationship, or another suitable heat transfer relationship.

Generally, the liquid-to-suction heat exchanger 142 transfers heat between the relatively hot working fluid exiting the condenser 162 and colder biphasic working fluid exiting the evaporator 140. The hotter working fluid can increase the temperature and vapor quality of the stream exiting from the evaporator 140 in the liquid-to-suction heat exchanger 142 such as to provide a higher level of sub-cooling (or a lower temperature and lower vapor quality) of the working fluid flowing from the condenser to increase the evaporator capacity. The partially evaporated refrigerant flowing from the evaporator is further evaporated by heat transfer with warmer partially condensed (or performs subcooling of) refrigerant flowing from the condenser. Further, the liquid-to-suction heat exchanger 142 does not superheat the suction gas in certain variations.

The heating of the working fluid exiting the liquid-to-suction heat exchanger 142 adjusts to a superheated level that is either positive or negative as it enters a flash tank 206.

After exiting the first side 142A of the liquid-to-suction heat exchanger 142, the working fluid may be at near-saturated vapor conditions and enters the flash tank 206. The flash tank 206 separates the working fluid into gas/vapor phase working fluid, or vapor stream, from the liquid phase working fluid, or liquid stream. After exiting the flash tank 206, the vapor stream 232 at point 240 enters the compressor 150 and the liquid stream 180 at point 242 enters the liquid pump 202.

The compressor 150 and the liquid pump 202 are in parallel with one another. The compressor 150 compresses the vapor stream 240 and forms a high-pressure vapor stream exiting the compressor 150. The compressor 150 may be a fixed speed compressor, a variable speed compressor, a multi-step compressor, or another suitable type of compressor. The gas stream 234 of the working fluid exiting the compressor has a pressure that is greater than the pressure of the vapor stream 240.

The liquid pump 202 pumps the liquid stream to a pressure for condensing and forms a high-pressure liquid stream exiting the liquid pump 202. The control module 602 controls the liquid pump 202. The control module 602 selectively adjusts a speed of the liquid pump 202 based on a difference in first, a targeted concentration of a second refrigerant circulating within the system and, second, a temperature (ΔT) between a measured temperature (Tmeas) 606 of the thermostat 204 and a setpoint temperature (Tset) 604 set by the control module 602. The control module 602 changes the speed of the liquid pump 202 at different rates, for example, by offset, stepwise, or in other ways to achieve first, a targeted concentration of a second refrigerant circulating within the system and, second, a target temperature difference (ΔT) between the measured temperature (Tmeas) 606 of the thermostat 204 and the setpoint temperature (Tset) 604. The outlet of the compressor 150 and the liquid pump 202 blend at point 234 to create a refrigerant blend (the working fluid) that enters the condenser 162.

The condenser 162 is disposed downstream of the compressor 150 and liquid pump 202 and thus receives the refrigerant blend at condenser inlet 160. The working fluid enters the inlet of condenser 162 as a blend of liquid and gas. The liquid and gas composition of the working fluid is dependent on the speed of the liquid pump 202 relative to the vapor refrigerant flow through the compressor 150 which may be a fixed speed compressor, a variable speed compressor, a multi-step compressor, or another suitable type of compressor. The working fluid exits the condenser 162 as partially or completely condensed to a near-saturated liquid at point 236. The vapor quality, or mass fraction of vapor of the working fluid (liquid stream at point 236) that exits the condenser 162 may be in an amount ranging from subcooled liquid to less than or equal to 25% vapor quality, such as 10% vapor quality, optionally 5% vapor quality, optionally 1% vapor quality, by way of non-limiting examples.

The condenser 162 transforms two-phase pressurized two-phase stream 234 to a predominantly liquid phase (for example, the first refrigerant (A) transforms from a gas to a liquid). The condenser 162 transfers heat from the working fluid to air passing the condenser 162. The condenser 162 may be located in a room or space where heat may be expelled, for example, indoors. The working fluid having the refrigerant blend of the first refrigerant (A) and the second refrigerant (B) may be partially condensed to form a multiphase mixture of both liquid and optionally gas/vapor.

After passing through the condenser 162, the working fluid is or includes a higher-pressure liquid stream 236. The higher-pressure liquid stream 236 of working fluid passes into the second side 142B of the liquid-to-suction heat exchanger 142 in a second flow direction and heat will be transferred with the distinct stream of the working fluid passing in the first flow direction in the first side 142A of the liquid-to-suction heat exchanger 142.

After exiting the second side 142B of the liquid-to-suction heat exchanger 142, the working fluid may be a subcooled liquid at point 239. A valve 210 is disposed between the 142B outlet of the liquid-to-suction heat exchanger 142 and the evaporator 140. The valve 210 allows flow to be stopped/slowed down. After this, the working fluid enters the evaporator 140 and circulates in a loop. The control module 602 controls the opening and closing of the valve 210, which controls the flow rate through the evaporator 140.

The control module 602 controls the concentrations of respective refrigerants in a working fluid having high glide, by varying the speed of the liquid pump 202. By incorporating the liquid-to-suction heat exchanger 142, the working fluid may be adjusted to have a positive or negative superheat at the inlet to the flash tank 206.

Referring now to FIG. 3, a functional block diagram of an example implementation of the control module 602 is presented. In various implementations, operation of the compressor can be adjusted to adjust capacity. Operation of the liquid pump and/or opening of the second expansion valve can be adjusted to adjust concentration.

A difference module 608 receives measurements from a measured temperature 606 measured by a temperature sensor and a temperature setpoint 604. The setpoint temperature 604 may be received, for example, from a thermostat or in another manner. The difference module 608 determines the mathematical difference (subtraction) between the temperature measured 606 and the temperature setpoint 604. For example, the difference module 608 may set the difference based on or equal to the measured temperature 606 minus the temperature setpoint 604. The measured temperature may be, for example, a measured temperature of air within the heated/cooled space and may be measured by a temperature sensor of the thermostat.

A deadband module 618 provides the predetermined deadband temperature. The predetermined deadband temperature may be a fixed predetermined temperature, such as approximately 10 degrees Fahrenheit or another suitable temperature.

The valve control module 610 controls opening and closing of the expansion valves (e.g., 146 152, and 210). A pump control module 614 controls whether the liquid pump 202 is on or off and if on, a speed of the liquid pump 202. A compressor control module 616 controls whether the compressor 150 is on or off and if on, a speed of the compressor 150. A power control module 630 receives power and provides power to the valve control module 610, the pump control module 614, and the compressor control module 616. The compressor control module 616 may not apply power to the compressor 150 for the compressor 150 to be off. The compressor control module 616 applies power to the compressor 150 for the compressor 150 to be on. The compressor control module 616 sets one or more characteristics of the power applied to the compressor 150 to control the speed of the compressor 150.

Referring now to FIG. 4, a method of selectively adjusting capacity and concentration is provided. Control may begin with 300 where the control module 602 receives user input which may include the temperature setpoint 604.

At 302, the control module 602 determines the difference between the measured temperature 606 and the temperature setpoint 604 plus/minus the predetermined deadband temperature. In other words, the control module 602 determines whether the difference is within the predetermined deadband temperature. The predetermined deadband temperature is upper bounded by an upper predetermined deadband temperature (+db) and lower bounded by a lower predetermined deadband temperature (−db). The magnitudes of the upper and lower predetermined deadband temperatures may be the same or different. The predetermined deadband temperature may be fixed or variable, such as by the deadband module 618. If the temperature difference plus/minus the predetermined deadband temperature 620 is a negative value (the difference is less than the lower predetermined deadband temperature), the control continues with 306. If the temperature difference plus/minus the predetermined deadband temperature 620 is a positive value (the difference is greater than the upper predetermined deadband temperature), the control continues with 304. If the temperature measured 606 is equal to the temperature setpoint 604 plus/minus the predetermined deadband temperature 620 (the difference is between the upper and lower predetermined deadband temperatures), control continues with 308.

At 306, the control module 602 increases the concentration of the second refrigerant (B) circulating through the system, which may have the effect of decreasing the capacity. For example, the valve control module 610 may open one of the first and second expansion valves 146 and 152 and/or close the other one of the first and second expansion valves 146 and 152. Additionally or alternatively, the compressor control module 616 may cycle the compressor, adjust the compressor capacity stage, or adjust the speed of the compressor 150.

At 304, the control module 602 reduces the concentration of the second refrigerant in the climate control system 120, which may have the effect of increasing the capacity. For example, the valve control module 610 may open one of the first and second expansion valves 146 and 152 and/or close the other one of the first and second expansion valves 146 and 152. Additionally or alternatively, the compressor control module 616 may cycle the compressor, adjust the capacity stage, or adjust the speed of the compressor 150.

At 308, the control module 602 determines to maintain capacity by maintaining concentration in the climate control system 120.

Examples of how to adjust the concentration (increase or decrease) are provided below in conjunction with the examples of FIGS. 5 and 6.

Referring now to FIG. 5, a flowchart depicting a method of adjusting concentration at the inlet of the accumulator 144 is provided. Control may begin with 402 where the valve control module 610 determines whether to increase the concentration, such as discussed above with respect to FIG. 4 (e.g., 306). If 402 is true, control may continue with 404. If 402 is false, control may continue with 406. As used herein, the concentration may refer to the concentration of the second refrigerant (B) circulating through the system 120.

At 406, the valve control module 410 determines whether to decrease the concentration. If 406 is true, control continues with 408. If 406 is false, control may return to 402.

At 404, the valve control module 610 closes the second expansion valve 152 (increases closing) and modulates opening and closing of the first expansion valve 146. This creates a positive superheat at the inlet of the accumulator 144 and increases the circulating concentration of the second refrigerant B through the system by reducing the storage of liquid refrigerant with a high concentration of the second refrigerant B circulating in the system, and control may return to 402. At 408, the valve control module 610 opens (increases opening) the second expansion valve 152 and modulates opening and closing of the first expansion valve 146. This creates a negative superheat at the inlet of the accumulator 144 and decreases circulating concentration of the second refrigerant B through the system by increasing the storage of liquid refrigerant with a high concentration of refrigerant B in the accumulator of the system, and control may return to 402. At 404 or 408, the valve control module 610 may modulate opening and closing of the first expansion valve 146 (e.g., a pulse width modulation signal applied to the first expansion valve 146) based on a predetermined target concentration. For example, the valve control module 610 may increase the PWM signal based on increasing the concentration toward the predetermined target concentration. The valve control module 610 may decrease the PWM signal based on decreasing the concentration toward the predetermined target concentration. In various implementations, the opposite may be true and the valve control module 610 may decrease the PWM signal based on increasing the concentration toward the predetermined target concentration and increase the PWM signal based on decreasing the concentration toward the predetermined target concentration. While the example of adjusting a PWM signal is provided, the present application is also applicable to modulating the first expansion valve 146 in another suitable manner.

For example, if the temperature measured 606 is greater than the temperature setpoint 604 plus/minus the deadband, the control module 602 may decrease the capacity of the climate control system 120. To decrease the capacity of the climate control system 120, the control module 602 may increase the concentration (e.g., 404). To increase the concentration, the valve control module 610 closes the second expansion valve 152 and modulates opening of the first expansion valve 146. The compressor control module 616 may also adjust the speed of the compressor 150. This increases the quantity of liquid refrigerant in the receiver 149 and decreases the liquid refrigerant in the accumulator 144 and creates superheat at the inlet of the accumulator 144.

As another example, if the concentration calculated is higher than the calculated target concentration setpoint, the control module 602 may decrease the concentration circulating within the climate control system 120. To decrease the concentration circulating within the climate control system 120, the control module 602 may decrease the concentration (e.g., 404) by reducing the superheat into the accumulator or by decreasing the speed of the liquid pump 202. To reduce the superheat into the accumulator, the valve control module 610 opens the second expansion valve 152 and modulates opening (e.g., opening and closing) of the first expansion valve 146. This decreases the quantity of liquid refrigerant in the accumulator 149 and increases the liquid refrigerant in the receiver 144 in order to store less liquid with a higher concentration of the second refrigerant (B) in the accumulator 144.

Referring now to FIG. 6, a flowchart depicting an adjusting concentration is provided. Control may begin with 502 where the pump control module 614 determines whether to increase the concentration, such as discussed above with respect to FIG. 4 (e.g.,306). If 502 is true, control may continue with 504. If 502 is false, control continues with 506.

At 506, the pump control module 614 determines whether to decrease the concentration. If 506 is true, control continues with 508. If 506 is false, control may return to 502.

At 504, the pump control module 614 increases the speed of the liquid pump 202, which decreases capacity and increases the concentration of the second refrigerant (B), and control may return to 502. Since the concentration of the second refrigerant B is high in the liquid phase of the flash tank, operating the liquid pump at a higher speed will increase the circulating concentration of the second refrigerant B throughout the system, and control may return to 502. At 508, the pump control module 614 decreases the speed of the liquid pump 202, which increases capacity and decreases the concentration, and control may return to 502. Since the concentration of the second refrigerant B is high in the liquid phase of the flash tank, operating the liquid pump at a lower speed will decrease the circulating concentration of refrigerant B throughout the system, and control may return to 502.

At 504 or 508, the valve control module 610 may modulate the pump 202 based on a predetermined target concentration. For example, the pump control module 614 may increase the PWM signal based on increasing the concentration toward the predetermined target concentration. The pump control module 614 may decrease the PWM signal based on decreasing the concentration toward the predetermined target concentration. In various implementations, the opposite may be true and the valve control module 610 may decrease the PWM signal based on increasing the concentration toward the predetermined target concentration and increase the PWM signal based on decreasing the concentration toward the predetermined target concentration. While the example of adjusting a PWM signal is provided, the present application is also applicable to modulating the pump 202 in another suitable manner.

The foregoing description is merely illustrative in nature and is in no way intended to limit the disclosure, its application, or uses. The broad teachings of the disclosure can be implemented in a variety of forms. Therefore, while this disclosure includes particular examples, the true scope of the disclosure should not be so limited since other modifications will become apparent upon a study of the drawings, the specification, and the following claims. It should be understood that one or more steps within a method may be executed in different order (or concurrently) without altering the principles of the present disclosure. Further, although each of the embodiments is described above as having certain features, any one or more of those features described with respect to any embodiment of the disclosure can be implemented in and/or combined with features of any of the other embodiments, even if that combination is not explicitly described. In other words, the described embodiments are not mutually exclusive, and permutations of one or more embodiments with one another remain within the scope of this disclosure.

Spatial and functional relationships between elements (for example, between modules, circuit elements, semiconductor layers, etc.) are described using various terms, including “connected,” “engaged,” “coupled,” “adjacent,” “next to,” “on top of,” “above,” “below,” and “disposed. ” Unless explicitly described as being “direct,” when a relationship between first and second elements is described in the above disclosure, that relationship can be a direct relationship where no other intervening elements are present between the first and second elements, but can also be an indirect relationship where one or more intervening elements are present (either spatially or functionally) between the first and second elements. As used herein, the phrase at least one of A, B, and C should be construed to mean a logical (A OR B OR C), using a non-exclusive logical OR, and should not be construed to mean “at least one of A, at least one of B, and at least one of C.”

In the figures, the direction of an arrow, as indicated by the arrowhead, generally demonstrates the flow of information (such as data or instructions) that is of interest to the illustration. For example, when element A and element B exchange a variety of information but information transmitted from element A to element B is relevant to the illustration, the arrow may point from element A to element B. This unidirectional arrow does not imply that no other information is transmitted from element B to element A. Further, for information sent from element A to element B, element B may send requests for, or receipt acknowledgements of, the information to element A.

In this application, including the definitions below, the term “module” or the term “controller” may be replaced with the term “circuit. ” The term “module” may refer to, be part of, or include: an Application Specific Integrated Circuit (ASIC); a digital, analog, or mixed analog/digital discrete circuit; a digital, analog, or mixed analog/digital integrated circuit; a combinational logic circuit; a field programmable gate array (FPGA); a processor circuit (shared, dedicated, or group) that executes code; a memory circuit (shared, dedicated, or group) that stores code executed by the processor circuit; other suitable hardware components that provide the described functionality; or a combination of some or all of the above, such as in a system-on-chip.

The module may include one or more interface circuits. In some examples, the interface circuits may include wired or wireless interfaces that are connected to a local area network (LAN), the Internet, a wide area network (WAN), or combinations thereof. The functionality of any given module of the present disclosure may be distributed among multiple modules that are connected via interface circuits. For example, multiple modules may allow load balancing. In a further example, a server (also known as remote, or cloud) module may accomplish some functionality on behalf of a client module.

The term code, as used above, may include software, firmware, and/or microcode, and may refer to programs, routines, functions, classes, data structures, and/or objects. The term shared processor circuit encompasses a single processor circuit that executes some or all code from multiple modules. The term group processor circuit encompasses a processor circuit that, in combination with additional processor circuits, executes some or all code from one or more modules. References to multiple processor circuits encompass multiple processor circuits on discrete dies, multiple processor circuits on a single die, multiple cores of a single processor circuit, multiple threads of a single processor circuit, or a combination of the above. The term shared memory circuit encompasses a single memory circuit that stores some or all code from multiple modules. The term group memory circuit encompasses a memory circuit that, in combination with additional memories, stores some or all code from one or more modules.

The term memory circuit is a subset of the term computer-readable medium. The term computer-readable medium, as used herein, does not encompass transitory electrical or electromagnetic signals propagating through a medium (such as on a carrier wave); the term computer-readable medium may therefore be considered tangible and non-transitory. Non-limiting examples of a non-transitory, tangible computer-readable medium are nonvolatile memory circuits (such as a flash memory circuit, an erasable programmable read-only memory circuit, or a mask read-only memory circuit), volatile memory circuits (such as a static random access memory circuit or a dynamic random access memory circuit), magnetic storage media (such as an analog or digital magnetic tape or a hard disk drive), and optical storage media (such as a CD, a DVD, or a Blu-ray Disc).

The apparatuses and methods described in this application may be partially or fully implemented by a special purpose computer created by configuring a general purpose computer to execute one or more particular functions embodied in computer programs. The functional blocks, flowchart components, and other elements described above serve as software specifications, which can be translated into the computer programs by the routine work of a skilled technician or programmer.

The computer programs include processor-executable instructions that are stored on at least one non-transitory, tangible computer-readable medium. The computer programs may also include or rely on stored data. The computer programs may encompass a basic input/output system (BIOS) that interacts with hardware of the special purpose computer, device drivers that interact with particular devices of the special purpose computer, one or more operating systems, user applications, background services, background applications, etc.

The computer programs may include: (i) descriptive text to be parsed, such as HTML (hypertext markup language), XML (extensible markup language), or JSON (JavaScript Object Notation) (ii) assembly code, (iii) object code generated from source code by a compiler, (iv) source code for execution by an interpreter, (v) source code for compilation and execution by a just-in-time compiler, etc. As examples only, source code may be written using syntax from languages including C, C++, C#, Objective-C, Swift, Haskell, Go, SQL, R, Lisp, Java®, Fortran, Perl, Pascal, Curl, OCaml, Javascript®, HTML5 (Hypertext Markup Language 5th revision), Ada, ASP (Active Server Pages), PHP (PHP: Hypertext Preprocessor), Scala, Eiffel, Smalltalk, Erlang, Ruby, Flash®, Visual Basic®, Lua, MATLAB, SIMULINK, and Python®.