COMPRESSED-AIR SYSTEM

Description

The present invention relates to a compressed air system, in particular for supplying compressed air to at least one consumer with fluctuating demand.

Compressed air systems usually consist of a plurality of fixed compressors that are configured to be switched on or off as required via a sequential pressure band control. Such a pressure band control requires permanent overcompression, which results in significant energy loss during operation. Based on the number of compressors integrated in the respective compressed air system, pressure bands between approximately 1.0 and 2.5 bar are common. Each bar of overcompression results in approximately 6-7% higher energy consumption. In addition, considerable leaks sometimes occur in compressed air systems, which are further increased by overcompression. The amount of leakage increases by approximately 14% per bar of pressure increase.

Furthermore, fluctuations in demand are usually compensated for by switching compressed air compressors on and off. Each switching operation of compressed air compressors causes temperature changes with corresponding material expansion and wear. In addition, each switching operation causes additional air loss (switching loss). Only compressors with low drive power may be switched on and off as often as required. Compressors in the medium power class are not switched off directly, but are operated in idle mode beforehand. Such idle operation is associated with approximately 30% power consumption without air delivery. The frequency and duration of the permissible switching operations are determined by the specifications of the respective manufacturer for the motors of the compressed air compressors and the respective power grid operator.

Finally, energy-efficient operation requires a relatively large number of compressed air compressors with different power ratings. Based on the operating situation, individual compressed air compressors will be shut down or run at idle operation. This results in high overall operating costs.

Against this background, the task of the present invention was to provide a compressed air system that enables operation with increased efficiency and stability while improving economic efficiency.

This task has been solved by the subject matter of claim 1. Advantageous embodiments are specified in the dependent claims and are explained below.

A compressed air system according to the invention, in particular for the supply of compressed air to at least one consumer with fluctuating demand, comprises a plurality of compressed air compressors connected in parallel, a pressure-boosting apparatus arranged upstream of at least some of the compressed air compressors for variably increasing an pre-pressure, and a control and/or regulating device which is configured to control and/or regulate the pressure-boosting apparatus based on a target pressure and/or actual pressure on the consumer side.

Connecting at least some or all of the compressed air compressors of a compressed air system to a pressure-boosting apparatus according to the invention makes it possible to significantly increase their delivery capacity. Industrial blowers available on the market could, for example, build up a pre-pressure of approx. 400 mbar, which in turn corresponds to an increase in mass flow of approx. 40%. This reduces the total number of compressed air compressors, which lowers the initial investment.

By varying the pre-pressure or the intake pressure, the respective compressed air compressors may function as regulated compressors or as controlled compressors. Varying the pre-pressure also makes it possible to operate the connected compressed air compressors permanently at their design point and thus in an operating range with maximum or high efficiency.

With a control and/or regulating device provided according to the invention, a variation in the pre-pressure of the respective compressed air compressors may be achieved reliably and reproducibly.

By varying the pre-pressure, efficient operation without a pressure band and without overcompression is possible. This enables significant energy savings of up to approximately 15% to be achieved. These energy savings may largely offset any energy expenditure for the pressure-boosting apparatus.

Finally, varying the pre-pressure and thus the variable delivery capacity of the compressed air compressors ensures that fewer switch-ons or switch-offs occur during operation of the compressed air system. This ensures lower maintenance costs and thus reduced operating costs.

According to a preferred embodiment, the control and/or regulating device may be configured to control and/or regulate the pressure-boosting apparatus to generate a variable pre-pressure based on a target/actual comparison of a consumer-side network pressure. This enables precise adjustment of the consumer-side network pressure. In addition, the actual pressure on the consumer side may be quickly adjusted to a new setpoint pressure during operation.

Furthermore, the control and/or regulating device may be configured to control and/or regulate a consumer-side actual pressure by variably adjusting the pre-pressure for at least some or all of the compressed air compressors by means of the pressure-boosting apparatus. Consequently, the actual pressure on the consumer side may be influenced in a suitable manner by adjusting the pre-pressure by means of the pressure-boosting apparatus, in particular without having to change the operation or the number of compressed air compressors in operation.

According to another preferred embodiment, the control and/or regulating device may be configured to control and/or regulate an actual pressure on the consumer side to a constant minimum pressure. In particular, control and/or regulation may be carried out by variably adjusting the pre-pressure for at least some or all of the compressed air compressors by means of the pressure-boosting apparatus. By setting a constant minimum pressure or a minimum pressure, particularly energy-saving compressed air operation may be ensured.

In an even more preferred embodiment, the pressure-boosting apparatus may be configured to variably increase the pre-pressure for all compressed air compressors. The pressure-boosting apparatus may be arranged upstream of all compressed air compressors. This enables the actual pressure on the consumption side to be adjusted over a particularly wide range, ensuring particularly efficient operation of the compressed air system.

According to another preferred embodiment, the pressure-boosting apparatus may comprise at least one blower for variably increasing the pre-pressure for a plurality of or all compressed air compressors. Such a blower may preferably be configured as a controllable blower. A blower is inexpensive to provide and may be arranged upstream of the respective compressed air compressors with only minor engineering effort. As explained above, commercially available industrial blowers could, for example, build up an pre-pressure of approx. 400 mbar. The energy required to operate such a blower may be largely offset by the energy savings resulting from efficient operation without pressure bands and without overcompression in the compressed air system.

In addition or as an alternative, the pressure-boosting apparatus may have a connection to a compressed air discharge, in particular a compressed air discharge for excess compressed air, for variable increase of the pre-pressure for a plurality of or all compressed air compressors. The pressure-boosting apparatus may also be formed by such a connection. Excess compressed air, for example from a downstream point in a compressed air system or from another compressed air system, may be fed via a connection to a compressed air discharge to a point upstream of the respective compressed air compressors, so that the pre-pressure may be variably adjusted. Such a connection may be equipped with a valve, for example.

It may also be advantageous if the pressure-boosting apparatus comprises a housing which is arranged upstream of a plurality of or all of the compressed air compressors and/or in which at least one fan for air compression is arranged. In this way, the pre-pressure for the respective compressed air compressors may be varied with only minimal structural effort. In particular, this enables an identical or essentially identical pre-pressure to be set for the respective compressed air compressors.

In an even more preferred embodiment, the pressure-boosting apparatus, in particular the blower, may be regulated and/or controlled with respect to rotational speed. This makes it possible to adjust the pre-pressure for the respective compressed air compressors with relatively little effort.

According to another preferred embodiment, the pressure-boosting apparatus, in particular the blower, may be regulated and/or controlled by an adjustable air guide device, which may in certain embodiments be realized as an adjustable air guide device, preferably by an adjustable inlet guide vane assembly. An adjustable air guide device or an adjustable inlet guide vane assembly is inexpensive to purchase.

In an even more preferred embodiment, at least one intake filter may be arranged upstream of the pressure-boosting apparatus, in particular for filtering an intake flow for a plurality of or all compressed air compressors. Such an intake filter may preferably be configured as a belt-type filter. Such an intake filter may ensure the supply of clean air for a plurality of or all compressed air compressors. In addition, the individual compressed air compressors may be configured without separate intake filters, which reduces the structural complexity and maintenance requirements of the compressed air compressors. A belt-type filter configuration is also particularly low-maintenance, requiring only rare manual intervention for maintenance work.

In another preferred embodiment, at least one pressure equalizing device may be connected in parallel to the pressure-boosting apparatus, in particular the blower. Preferably, a plurality of pressure equalizing devices may be connected in parallel to the pressure-boosting apparatus, in particular the blower. Such a pressure equalizing device ensures that the compressors are still supplied with filtered intake air even if the blower fails.

In a particularly preferred embodiment, the pressure equalizing device may be arranged inside a housing of the pressure-boosting apparatus. The pressure equalizing device and the pressure-boosting apparatus may also be arranged at a common housing wall portion. This ensures an overall compact and robust configuration.

In another preferred embodiment, the pressure equalizing device may be configured to automatically open a pressure equalizing opening. The pressure equalizing device may preferably comprise a vacuum relief flap, for example a vacuum relief flap, and a pressure equalizing opening which may be closed by the vacuum relief flap. Such a configuration ensures low susceptibility to faults and is simple to construct.

In an even more preferred embodiment, the pressure equalizing device may be configured to open a pressure equalizing opening, in particular automatically and/or against a spring bias, when a minimum pre-pressure for at least one compressed air compressor and/or for all compressed air compressors is not reached and/or when the pressure-boosting apparatus fails or stops. In this way, operation of the compressed air compressors at too low a pre-pressure or intake pressure may be prevented with a high degree of reliability.

According to another preferred embodiment, the pressure-boosting apparatus may be followed by a cooling device for cooling a pre-compressed air flow. The cooling device may preferably be arranged upstream of at least some of the compressed air compressors or all of the compressed air compressors. The pressure-boosting apparatus provided by the invention may cause the temperature of the pre-compressed process air to rise due to the variable increase in the pre-pressure or intake pressure. A temperature increase initially has a negative effect on the delivery capacity and/or efficiency of the compressed air compressors. However, such effects may be effectively compensated by means of a cooling device. In particular, a cooling device ensures that the compressed air compressors may be operated efficiently and therefore with relatively low energy consumption. Overall, this contributes to energy savings due to efficient operation without pressure bands and without overcompression in the compressed air system, which largely compensate for any energy consumption for the pressure-boosting apparatus.

In an even more preferred embodiment, the cooling device may run at least in sections through a housing for the pressure-boosting apparatus. This ensures a simple and compact configuration.

More preferably, the cooling device may comprise a heat exchanger, in particular a liquid-operated heat exchanger. Such a heat exchanger may be operated with cold river water and thus ensures a sufficient quantity of air for the compressed air compressors even at high intake temperatures, for example in midsummer.

It is even more preferred that at least some or all of the compressed air compressors are preceded by a manifold for distributing a pre-compressed air flow to the respective compressed air compressors. Such a manifold enables a pre-compressed air flow to be distributed evenly and with high reliability to the respective compressed air compressors. At the same time, the pre-compression of the air flow and/or a variable adjustment of the pre-pressure, may be carried out within a compact housing.

It may also be advantageous if the manifold is arranged downstream of the cooling device for cooling a pre-compressed air flow. In particular, the manifold may be arranged between the pressure-boosting apparatus and the respective compressed air compressors and/or between the cooling device and the respective compressed air compressors. The already pre-compressed and/or post-cooled process air flow may thus be fed to the respective compressed air compressors.

Even more preferably, the manifold may be configured as a component of a housing for the pressure-boosting apparatus and/or integrally connected to a housing for the pressure-boosting apparatus or formed in one piece. This ensures a structurally robust and space-saving configuration as well as simple installation of the compressed air system.

According to another preferred embodiment, at least some or all of the compressed air compressors may be arranged downstream of a common blow-off valve for reducing the pressure on the consumer side. Such a common blow-off valve may in turn be arranged upstream of the respective compressed air consumers supplied with compressed air by the compressed air system.

Advantageously a common blow-off valve may be configured to maintain a constant minimum pressure on the consumer side by discharging compressed air. This improves operational reliability and ensures that the desired or set consumer-side pressure is maintained.

In particular, a common blow-off valve enables individual compressed air compressors to be switched on and/or off without disrupting the downstream process. A sudden change in the pressure level caused by switching individual compressed air compressors on and/or off may be compensated for by controlled or regulated operation of the common blow-off valve.

For example, a failure of the pressure-boosting apparatus may require the activation of at least one or more compressed air compressors. In such a case, the activation of the common blow-off valve may prevent large pressure fluctuations on the consumer side. A setpoint of a pressure limit regulator of the common blow-off valve may be set to the current actual value of the consumer-side pressure. The arrangement of a common blow-off valve may ultimately make the use of buffer tanks unnecessary, ensuring an overall simple system configuration.

According to another preferred embodiment, the common blow-off valve may be configured as a control valve. The common blow-off valve may preferably be controlled and/or regulated by the control and/or regulating device. In this way, a high setting accuracy for the consumer-side pressure level may be achieved by means of the common blow-off valve.

Furthermore, the control and/or regulating device may be configured to control and/or regulate the common blow-off valve based on a consumer-side setpoint pressure. In addition or alternatively, the control and/or regulating device may be configured to control and/or regulate the common blow-off valve based on an actual pressure on the consumer side and/or a comparison between the actual and setpoint pressure on the consumer side. The control and/or regulating device may therefore be configured to control and/or regulate the pressure-boosting apparatus and also the common blow-off valve, resulting in a particularly high degree of setting accuracy and flexibility in the operation of the compressed air system.

In addition or alternatively, the control and/or regulating device may be set up to control and/or regulate an actual pressure on the consumer side to a constant minimum pressure by means of the blow-off valve. In this way, undesirable overpressures or high pressure fluctuations on the consumer side may be avoided.

According to another preferred embodiment, the control and/or regulating device may be configured to switch at least one compressed air compressor, in particular to switch it on or off, and/or to control and/or regulate it, in response to an operating position of the blow-off valve. This ensures that a suitable number of compressed air compressors are in operation for the respective operating situation or that the respective compressed air compressors are suitably adjusted. This prevents, for example, unnecessary large amounts of excess compressed air from being blown out via the blow-off valve due to too many active compressed air compressors for the respective operating situation. The position of the blow-off valve may advantageously be evaluated to determine whether switching on compressed air compressors or increasing the delivery capacity of controllable or regulated compressors is or will soon be required to maintain a defined pressure level on the consumer side. This further improves the operational reliability and accuracy of the compressed air system.

Furthermore, the control and/or regulating device may be configured to switch, in particular to switch on or off, and/or to control and/or regulate at least one compressed air compressor in response to an operating position assumed by the blow-off valve upon passing through a predetermined threshold value. Consequently, when the blow-off valve passes a predetermined threshold value, a switching operation, in particular switching on or off, or a control and/or regulation of at least one compressed air compressor may be initiated. Such switching, control and/or regulation of at least one compressed air compressor may ensure that a consumer-side target pressure is maintained with increased reliability and overall reduced energy consumption.

Even more preferably, the control and/or regulating device may be configured to switch, in particular to switch on or off, and/or to control and/or regulate at least one compressed air compressor in response to an operating position of the blow-off valve upon falling below a lower threshold and/or upon exceeding an upper threshold value. In a particularly preferred embodiment, a lower threshold value of the blow-off valve may be set at an operating position of 20% open and/or an upper threshold value of the blow-off valve may be set at an operating position of 80% open. Any predetermined threshold values may, for example, be set and/or subsequently changed with little effort, for example to adapt or optimize the compressed air system with regard to the respective operating conditions.

According to another preferred embodiment, at least one expansion turbine may be provided and/or may be disposed downstream of the common blow-off valve. Blow-off compressed air may be fed to an expansion turbine via the blow-off valve. The use of an expansion turbine for energy recovery from blow-off compressed air may advantageously ensure overall energy-saving operation.

Similarly, an expansion turbine may be arranged upstream of the common blow-off valve and/or compressed air blown out via the blow-off valve may be fed to an expansion turbine before being blown out. This arrangement enables compressed air that has already been expanded to be blown out via the blow-off valve. At the same time, the use of an expansion turbine may in turn enable energy recovery by means of blown-out compressed air, thus ensuring overall energy-saving operation.

Furthermore, a plurality of blow-off valves may be provided, in particular a plurality of blow-off valves connected in parallel to each other. Such an arrangement of a plurality of blow-off valves enables compressed air to be blown off via different blow-off valves and/or blow-off lines, in particular based on different operating states. For example, discharging via one blow-off valve may happen based on and/or independently of discharging via the other blow-off valve.

Even more preferably, when a plurality of blow-off valves are arranged, at least one first blow-off valve may be arranged upstream or downstream of an expansion turbine. A different or second blow-off valve or a plurality of additional blow-off valves may be connected in parallel to the first blow-off valve assigned to the expansion turbine. Compressed air may be blown off via a second blow-off valve not assigned to the expansion turbine without having to be expanded via the expansion turbine.

If a first blow-off valve is arranged upstream of an expansion turbine, it may be a supply valve for the supply of compressed air to an expansion turbine.

In a particularly preferred embodiment, a temperature sensing device at the outlet of the expansion turbine or in a line arranged downstream of the expansion turbine may be provided. If the monitoring of the temperature signal detects a critical operating condition, in particular a risk of icing, a supply valve for the supply of compressed air to an expansion turbine may be throttled or closed. Any necessary pressure limitation of the process pressure may be carried out by a blow-off valve connected in parallel.

In a preferred embodiment, the expansion turbine may be connected to a generator for power generation. Expelled compressed air may therefore be employed to generate electricity, further improving overall energy efficiency. In particular, electricity generated in this way may be utilized to supply power to one or more system components or to the power grid.

It may also be advantageous if the expansion turbine is mechanically coupled to a drive motor for the pressure-boosting apparatus, in particular through an intermediate gearbox and/or a freewheel device. The energy recovered from the blown-off compressed air may thereby be employed to assist or drive the pressure-boosting apparatus, thereby improving overall energy efficiency.

In another preferred embodiment, the expansion turbine may be mechanically coupled to at least one drive motor of a compressed air compressor, in particular through an intermediate gearbox and/or a freewheel device. The energy recovered from the blown-off compressed air may thereby be utilized to drive the compressed air compressor, thereby reducing its external energy demand.

In an even more preferred embodiment, the expansion turbine may be connected to a drive motor of another unit with a rotating shaft, in particular through an intermediate gearbox and/or via an intermediate freewheel device. This may be a unit that is part of the respective compressed air system or not part of the respective compressed air system, i.e. it is provided and/or configured independently of the compressed air system, with the exception of the coupling with the expansion turbine.

It is further particularly preferred that the expansion turbine is connected to a shaft end, in particular a free shaft end, of a unit and/or a motor. Such a connection may in turn be realized via an intermediate gearbox and/or via an intermediate freewheel device. This ensures particularly reliable power transmission from the expansion turbine to the respective shaft of the unit or motor.

In an even more preferred embodiment, a plurality of expansion turbines may be provided, each mechanically coupled to a drive motor of a compressed air compressor, in particular through an intermediate gearbox and/or a freewheel device. The energy recovered from the blown-off compressed air may thereby be utilized to drive multiple compressed air compressors, reducing their external energy demand. This further enhances the overall energy efficiency of the compressed air system.

According to another preferred embodiment, a supply valve for the supply of compressed air to the expansion turbine may be arranged between the common blow-off valve and the expansion turbine, in particular a supply valve configured as a switching valve and/or an ON/OFF valve. Based on the operating situation, a coordinated compressed air supply to the expansion turbine may be ensured. If a compressed air supply to the expansion turbine is not required in the respective operating state, the switching valve may remain in a CLOSED position.

In another preferred embodiment, a common blow-off valve and a supply valve for the compressed air supply to the expansion turbine may be connected in parallel. In this way, excess compressed air may be blown off via the common blow-off valve and fed in parallel to the downstream expansion turbine via the supply valve.

It is further preferred that at least some or all of the compressed air compressors are followed by an outlet valve for discharging compressed air into the atmosphere, in particular an outlet valve configured as a switching valve and/or an ON/OFF valve. Excess compressed air may be discharged into the environment with only minimal effort via such an outlet valve.

The outlet valve may preferably be arranged downstream of the common blow-off valve. When the outlet valve is in the OPEN position, excess compressed air may be blown off into the environment, whereby the amount of excess compressed air blown off may be suitably controlled and/or regulated via the common blow-off valve.

It is further preferred that the outlet valve is connected in parallel to the supply valve for the compressed air supply to the expansion turbine. Excess compressed air may be fed to the outlet valve and/or to the supply valve via the common blow-off valve. The compressed air conducted via the common blow-off valve may thus be fed to the outlet valve and blown off into the environment or conducted to the expansion turbine via the supply valve.

According to another preferred embodiment, a buffer storage for storing compressed air may be provided and/or arranged downstream of the common blow-off valve. Compressed air discharged via the outlet valve may be fed to a buffer storage. The compressed air stored in a buffer storage may be supplied to the respective compressed air consumers in the event of a short-term drop in pressure or a short-term increase in pressure demand. This ensures improved operational reliability and a more reliable compressed air supply.

It may also be advantageous to connect a pneumatic pressure intensifier upstream of the buffer storage and/or downstream of the blow-off valve in order to increase the pressure of the compressed air blown into the buffer storage. Such a pneumatic pressure intensifier may increase the pressure level and thus the amount of air buffered within the buffer storage, and a predetermined or required pressure level may be maintained for a certain period of time by feeding from the buffer storage.

In another preferred embodiment, an infeed valve for the supply of compressed air to the consumer side may be arranged downstream of the buffer storage. Such an infeed valve may be configured as a controlled and/or regulated valve or as a switching valve or ON/OFF valve. Based on the operating condition, the infeed valve may be actuated to feed compressed air to the consumer side in a controlled manner.

In another preferred embodiment, the control and/or regulating device may be configured to control the outlet valve and/or the supply valve and/or the infeed valve. Similarly, if the respective valve is configured accordingly, the control and/or regulating device may be configured to regulate the outlet valve and/or the supply valve and/or the infeed valve. The control and/or regulating device may therefore be configured as a central or common control and/or regulating device. In particular, a plurality of or all components or valves of the compressed air system may be controlled and/or regulated via the control and/or regulating device, so that a plurality of or all settings may be initiated by a single unit.

In a further preferred embodiment, the control and/or regulating device is configured to control and/or regulate the outlet valve, the supply valve, and/or the infeed valve. Based on the design of the respective valve, the control and/or regulating device may be adapted to perform either open-loop control or closed-loop regulation of these valves. The control and/or regulating device may be implemented as a central or common unit, in particular for controlling and/or regulating a plurality of or all components or valves of the compressed air system, so that multiple or all settings can be initiated from a single unit.

The control and/or regulation to a constant minimum pressure may ensure a high level of energy efficiency. At the same time, such a configuration increases the flexibility of possible adjustments, as the actual pressure on the consumer side may be influenced not only via the pressure-boosting apparatus, but also via the outlet valve and/or the supply valve and/or the infeed valve. In addition, such a control and/or regulation unit may be configured to control and/or regulate a plurality of valves, in particular beyond the control and/or regulation of the pressure-boosting apparatus.

In another preferred embodiment, at least some or all of the compressed air compressors may be configured as unregulated fixed compressors. Such fixed compressors, for the purposes of the present invention, may be operated with predetermined and unchangeable operating parameters or with a predetermined and fixed rotational speed. Fixed compressors are inexpensive to purchase, require little maintenance, and ensure efficient operation for compressed air generation and/or pressure boosting.

In addition or alternatively, at least one of the compressed air compressors may be configured as a regulated or controllable compressor. Similarly, a plurality of compressed air compressors may be configured as regulated or controllable compressed air compressors. Regulated or controllable compressed air compressors may be adjustable in terms of delivery capacity and/or operating power and/or rotational speed and thus adjustable in terms of their operating parameters to the respective operating situation. Such compressors may be, for example, a VSD compressor. The use of a VSD compressor increases the flexibility of the compressed air system for different operating conditions and serves to maintain the desired or required set pressure on the consumer side.

According to another preferred embodiment, at least one of the compressed air compressors may be configured as a regulated or controllable compressed air compressor and operated as a fixed compressor with a fixed predetermined rotational speed. Such a compressed air compressor may be operated in an optimum range in terms of efficiency, for example with a delivery capacity of more than 70% or less than 90%, in particular approximately 80%.

According to another preferred embodiment, the control range or control area of a regulated or controllable compressed air compressor may be larger than the delivery capacity of a fixed compressor, in particular larger than the delivery capacity of the fixed compressor with the largest delivery capacity. In this way, the delivery capacity of a fixed compressor may be compensated by adjusting the at least one regulated or controllable compressed air compressor, whereby the number of required switch-ons or switch-offs of compressed air compressors may be further reduced during operation.

In an even more preferred embodiment, the control and/or regulating device may be configured to switch, in particular to switch on or off, at least one compressed air compressor configured as a fixed compressor based on a rotational speed and/or an operating state of a regulated compressed air compressor. This ensures that an advantageous number of fixed compressors are in operation for the respective operating situation or that a regulated compressed air compressor is set or operated in a suitable operating range.

It may also be advantageous if the control and/or regulating device is configured to switch at least one compressed air compressor configured as a fixed compressor, in particular to switch it on or off, based on an operating state assumed by a regulated compressed air compressor upon passing through a threshold rotational speed. Consequently, when the regulated compressed air compressor passes a threshold value, a switch, in particular an on or off switch, or a control and/or regulation of at least one fixed compressor may be initiated. Such switching, control and/or regulation of at least one fixed compressor may ensure that a consumer-side target pressure is maintained with increased reliability and overall reduced energy consumption.

According to another preferred embodiment, the control and/or regulating device may be configured to switch, in particular switch on or off, at least one compressed air compressor configured as a fixed compressor based on an operating state of a regulated compressed air compressor which is reached when a rotational speed falls below a lower threshold and/or an upper threshold rotational speed is exceeded. In a particularly preferred embodiment, a lower threshold rotational speed of a controlled compressed air compressor may be set at 40% and/or 50% of the maximum rotational speed and/or at a value greater than 40% and/or 50% of the maximum rotational speed. In addition or alternatively, an upper threshold rotational speed of a regulated compressed air compressor may be set at 80% and/or 90% and/or 100% and/or at a value greater than 80% of the maximum rotational speed. Such predetermined threshold values may be set in a particularly advantageous manner and/or may be changed subsequently with little effort, for example to adapt or optimize the compressed air system with regard to the respective operating conditions.

Even more preferably, the control and/or regulating device may be configured to control and/or regulate a consumer-side actual pressure free of a pressure band to a constant minimum pressure. The energy efficiency of the compressed air system may be improved in a particularly advantageous manner in this way, in particular by avoiding excess compressed air generation or by avoiding excessive overpressure on the consumer side.

The control and/or regulating device may be further configured to switch one or more compressed air compressors on and/or off and/or to control and/or regulate their operating state based on a consumer-side setpoint pressure and/or actual pressure and/or based on a setpoint/actual comparison of a consumer-side pressure. The actual pressure on the consumer side may therefore also be achieved by switching on and/or off and/or changing the operating state of one or more compressed air compressors via the variable setting of the pre-pressure by the pressure-boosting apparatus. This enables a larger overall setting range for the actual pressure on the consumer side to be achieved, thereby further improving operational flexibility and reliability.

In an even more preferred embodiment, the control and/or regulating device may be configured to generate a variable adjustment of the pre-pressure for at least some or all of the compressed air compressors by means of the pressure-boosting apparatus when one or more compressed air compressors are switched on and/or off. This prevents or at least reduces disturbances or strong pressure fluctuations on the consumer side caused by the switching on or off of compressed air compressors.

In an even more preferred embodiment, the control and/or regulating device may be configured to control and/or regulate the pressure-boosting apparatus based on a rotational speed and/or an operating state of a regulated compressed air compressor, in particular to control and/or regulate the generation of a variable pre-pressure. This allows the energy efficiency to be further improved. On the one hand, the pre-pressure may be set In another advantageous manner, taking into account additional operating parameters. At the same time, a controlled compressed air compressor may be set or operated in an advantageous operating range with even greater reliability and accuracy.

More preferably, the control and/or regulating device may be configured to control and/or regulate the pressure-boosting apparatus based on an operating state assumed by a regulated compressed air compressor upon passing through a threshold rotational speed. Consequently, when the controlled compressed air compressor passes a predetermined threshold value, control and/or regulation of the pressure-boosting apparatus may be initiated. Such initiated control and/or regulation of the pressure-boosting apparatus may ensure that a consumer-side target pressure is maintained with increased reliability and overall reduced energy consumption.

In a particularly preferred embodiment, the control and/or regulating device may be configured to control and/or regulate the pressure-boosting apparatus based on an operating state of a regulated compressed air compressor when rotational speed falls below a lower threshold and/or an upper threshold rotational speed is exceeded. Furthermore, a lower threshold rotational speed of a regulated compressed air compressor may be set at 40% or 50% of the maximum rotational speed and/or at a value greater than 40% and/or 50% of the maximum rotational speed. In addition or alternatively, an upper threshold rotational speed of a regulated compressed air compressor may be set at 80% and 90% or 100% of the maximum rotational speed and/or at a value greater than 80%. Such predetermined threshold values may be set in a particularly advantageous manner and/or may be changed retrospectively with little effort, for example to adapt or optimize the compressed air system with regard to the respective operating conditions.

In an even more preferred embodiment, the control and/or regulating device may be configured to continue controlling and/or regulating and/or changing the operating state of the pressure-boosting apparatus until a regulated compressed air compressor has reached and/or passed a predetermined rotational speed within a target rotational speed range. In this way, the operating efficiency of the regulated compressed air compressor may be improved in a particularly advantageous manner and with high operational reliability.

According to another preferred embodiment, a control and/or regulation range achieved by means of the pressure-boosting apparatus may be greater than the delivery capacity of at least one compressed air compressor, in particular the compressed air compressor with the largest delivery capacity. In this way, the delivery capacity of a compressed air compressor may be compensated by variable adjustment of the pre-pressure by means of the pressure-boosting apparatus, whereby the number of required switch-ons or switch-offs of compressed air compressors may be further reduced during operation.

According to another preferred embodiment, the blow-off valve and/or the outlet valve may be configured and/or dimensioned to blow out the delivery capacity of at least one of the compressed air compressors, in particular the compressed air compressor with the largest delivery capacity, preferably with a margin of at least 30%. In this way, the delivery capacity of a compressed air compressor may be completely blown out, for example for a relatively short period of time, whereby the number of required switching operations of compressed air compressors may be further reduced during operation.

Another independent aspect of the present invention relates to a compressed air system, in particular for the supply of compressed air to at least one consumer with fluctuating demand, with a plurality of compressed air compressors connected in parallel and with a pressure-boosting apparatus which is arranged upstream of at least some of the compressed air compressors for variably increasing a pre-pressure. In a preferred embodiment, such a compressed air system may be equipped with a control and/or regulating device which is configured to control and/or regulate the pressure-boosting apparatus.

Another independent aspect of the present invention relates to a compressed air system, in particular for the supply of compressed air to at least one consumer with fluctuating demand, comprising a plurality of compressed air compressors connected in parallel, a blow-off valve which is configured as a control valve and is arranged downstream of at least some of the compressed air compressors for reducing the pressure on the consumer side, and with a control and/or regulating device which is configured to control and/or regulate the blow-off valve based on a consumer-side setpoint pressure and/or actual pressure.

Another independent aspect of the present invention relates to a compressed air system, in particular for the supply of compressed air to at least one consumer with fluctuating demand, comprising a plurality of compressed air compressors connected in parallel and a blow-off valve which is configured as a control valve and is arranged downstream of at least some of the compressed air compressors for reducing the pressure on the consumer side. In a preferred embodiment, such a compressed air system may be equipped with a control and/or regulating device which is configured to control and/or regulate the blow-off valve.

Another independent aspect of the present invention relates to a compressed air system, in particular for the supply of compressed air to at least one consumer with fluctuating demand, comprising a plurality of compressed air compressors connected in parallel and a control and/or regulating device, wherein at least one of the compressed air compressors is configured as a fixed compressor and at least one of the compressed air compressors is configured as a regulated compressed air compressor, and wherein the control and/or regulating device is configured to switch, in particular switch on or off, at least one compressed air compressor configured as a fixed compressor based on a rotational speed and/or an operating state of a regulated compressed air compressor.

Another independent aspect of the present invention relates to a method for operating a compressed air system, in particular for the supply of compressed air to at least one consumer with fluctuating demand, in which a plurality of compressed air compressors connected in parallel are operated and in which the pre-pressure of at least some of the compressed air compressors is increased variably and based on a consumer-side setpoint pressure and/or actual pressure by means of a pressure-boosting apparatus.

Another independent aspect of the present invention relates to a method for operating a compressed air system, in particular for the supply of compressed air to at least one consumer with fluctuating demand, in which a plurality of compressed air compressors connected in parallel are operated and in which a consumer-side pressure reduction is effected by means of a blow-off valve, which is configured as a control valve and is arranged downstream of at least some of the compressed air compressors, based on a consumer-side setpoint pressure and/or actual pressure.

The preferred embodiments and advantages of the compressed air system described above also apply in the same way to the other independent aspects described above and to the methods described for operating a compressed air system.

With regard to the advantages resulting from the present invention, reference is also made to the following details and calculations.

Based on a report by the German Federal Environmental Agency entitled “Potenzialstudie Energie-/Kosteneinsparung in der Fluidtechnik” (Potential study on energy/cost savings in fluid technology) from 2021, it may be estimated that there are approximately 70,000 compressed air compressors in Germany with a total power consumption of approximately 20 billion kWh. Assuming a rate of just €0.1/kWh, this results in total electricity costs of €2 billion per year.

If, for example, 50 compressed air suppliers in Germany alone optimized or implemented only 2 systems per year with an average output of 500 KW in accordance with the invention and achieved energy savings of at least 10%, this would result in savings of €5 million in the first year, €10 million in the second year, and so on. Germany's share of the global market is less than 10%.

For each optimization project, for example, up to three containerized housings may be required, one housing for the blower, filter, injection system and heat exchanger, and one intake manifold. This results in an attractive ROI of less than three years for the plant operator, with even more favorable results as the size of the system increases.

The solution presented is also particularly advantageous from an environmental point of view. The energy efficiency of a technology is key to reducing energy consumption and thus also CO₂ emissions. Apart from the fact that specific carbon dioxide emissions vary based on the type of power generation, according to a publication by the German Federal Office “Entwicklung der spezifischen Treibhausgas-Emissionen des deutschen Strommix in den Jahren 1990-2021” (Development of specific greenhouse gas emissions from the German electricity mix in the years 1990-2021), the generation of one kilowatt hour of electricity in Germany in 2021 is related to an average of 420 grams of CO₂. In the above example, this would correspond to a total saving of around 17,640 metric tons of CO₂ per year or an average annual saving of 176.4 metric tons of CO₂ per installation configured or converted in accordance with the invention.

The invention is described below by way of example with reference to the accompanying figures. The following figures show schematically:

FIG. 1 a compressed air system according to an embodiment of the present invention,

FIG. 2 a compressed air system according to another embodiment of the present invention,

FIG. 3 a compressed air system according to a further embodiment of the present invention,

FIG. 4 a compressed air system according to a further embodiment of the present invention,

FIG. 5 a compressed air system according to a further embodiment of the present invention,

FIG. 6 a compressed air system according to a further embodiment of the present invention,

FIG. 7 a compressed air system according to a further embodiment of the present invention

FIG. 8A compressed air system according to a further embodiment of the present invention,

FIG. 9 a compressed air system according to a further embodiment of the present invention

FIG. 10 a compressed air system according to a further embodiment of the present invention.

FIG. 1 shows a compressed air system 10 according to an embodiment of the present invention. The compressed air system 10 is configured in particular for the supply of compressed air to at least one compressed air consumer with fluctuating demand, which is not shown in detail here, preferably for a plurality of compressed air consumers with fluctuating demand, either individually or collectively.

The compressed air system 10 comprises a plurality of compressed air compressors 12 connected in parallel and a pressure-boosting apparatus 14 which is arranged upstream of at least some of the compressed air compressors 12 for variably increasing a pre-pressure. A check valve 16 is arranged downstream of each of the compressed air compressors 12. The check valves 16 prevent damage to the respective compressed air compressors 12, in particular when the respective compressed air compressor 12 is at a standstill. In addition, the check valves 16 prevent compressed air from escaping via a stationary compressed air compressor 12.

Furthermore, the compressed air system 10 comprises a control and/or regulating device 18 which is configured to control and/or regulate the pressure-boosting apparatus 12 based on a consumer-side setpoint pressure and/or actual pressure. An actual pressure on the consumer side may be detected by the control and/or regulating device 18, for example in a pipe section 20. The control and/or regulating device 18 may be configured to control and/or regulate the pressure-boosting apparatus 14 to generate a variable pre-pressure based on a setpoint/actual comparison of a consumer-side pressure, in particular a setpoint/actual comparison of a consumer-side pressure in the line section 20.

The control and/or regulating device 18 may preferably be configured to control and/or regulate a consumer-side actual pressure, in particular in the line section 20, to a constant minimum pressure, in particular by variable adjustment of the pre-pressure for at least some or all of the compressed air compressors 12 by means of the pressure-boosting apparatus 14. The pressure-boosting apparatus 14 may be configured to variably increase the pre-pressure for all compressed air compressors 12. The pressure-boosting apparatus 14 may be arranged upstream of all compressed air compressors 12 for this purpose.

The pressure-boosting apparatus 14 may comprise a fan 22 for variably increasing the pre-pressure for a plurality of or all of the compressed air compressors 12. The fan 22 may be driven by a drive motor 24 which is controlled by the control and/or regulating device 18 or is connected thereto. Based on the desired set pressure and/or the prevailing actual pressure on the consumer side, the control and/or regulating device 18 may control the drive motor 24 for the blower 22 as appropriate and thus increase or decrease the pre-pressure of the compressed air compressors 12.

The pressure-boosting apparatus 14, in particular the blower 22, may be configured to be regulated and/or controlled with respect to its rotational speed. Regulation and/or control of the rotational speed of the pressure-boosting apparatus 14 or the blower 22 may be achieved via the control and/or regulating device 18. A separate control and/or regulating device, not shown in detail here, may also be provided for this purpose.

The pressure-boosting apparatus 14, in particular the fan 22, may be additionally or alternatively adjustable and/or controllable by means of an adjustable air guide device 26. The air guide device 26 also encompasses what is here referred to as an air guide device and may be configured as adjustable inlet guide vane assembly. The air guide device 26 may be driven by a drive motor 28, which in turn is controlled by the control and/or regulating device 18 or is connected to it. Based on the desired set pressure and/or the prevailing actual pressure on the consumer side, the control and/or regulating device 18 may suitably control the drive motor 28 for the air guide device 26 and thus increase or decrease the pre-pressure of the compressed air compressors 12. For example, when the air control unit 26 is in a closed position, the pre-pressure for the compressed air compressors 12 may be reduced, and when the air control unit 26 is in an open position, the pre-pressure for the compressed air compressors 12 may be increased.

The pressure-boosting apparatus 14 may also have a housing 30 which is arranged upstream of a plurality of or all of the compressed air compressors 12. The pressure-boosting apparatus 14, in particular the fan 22 and/or the air guide device 16, may be arranged in the housing 30.

The pressure-boosting apparatus 14 may also have an intake filter 32 arranged upstream, in particular for filtering an intake flow for a plurality of or all of the compressed air compressors 12. The intake filter 32 is preferably configured as a belt-type filter. The intake filter 32 may be arranged inside the housing 30. Finally, a protective bird screen 34 may be arranged upstream of the intake filter 32. Such a protective bird screen 34 may be inserted into an opening 36 of the housing 30 or positioned in an opening 36 of the housing 30.

At least one pressure equalizing device 38, preferably a plurality of pressure equalizing devices 38, may be connected in parallel to the pressure-boosting apparatus 14, in particular to the blower 22. The pressure equalizing device 38 may also be arranged inside a housing 30 and together with the pressure-boosting apparatus 14 at a common housing wall portion 40. The pressure equalizing device 38 may be configured to automatically open a pressure equalizing opening 42. For this purpose, the pressure equalizing device 38 may have a vacuum relief flap 46 loaded by a spring 44, by means of which the pressure equalizing opening 42 may be closed.

The pressure equalizing device 38 may be configured to open the pressure equalizing opening 42 when the minimum pre-pressure for at least one compressed air compressor 12 or for all compressed air compressors 12 is not reached, in particular to open automatically and/or against the preload of the spring 44. The pressure equalizing device 38 may also be configured to open the pressure equalizing opening 42, in particular automatically and/or against the preload of the spring 44, if the pressure-boosting apparatus 14 fails or stops. This prevents the formation of undesirable negative pressure within the housing 30 or upstream of the compressed air compressors 12 with a high degree of reliability.

The compressed air system 10 may also be equipped with a cooling device 48. The cooling device 48 may be arranged downstream of the pressure-boosting apparatus 12 for cooling a pre-compressed air flow and upstream of at least some of the compressed air compressors 12. The cooling device 48 may run at least in sections through the housing 30 for the pressure-boosting apparatus 14. The cooling device 48 may have a heat exchanger, especially a liquid-operated heat exchanger, or be made up of a heat exchanger.

The compressed air system 10 may further comprise a manifold 50 which is arranged upstream of at least some or all of the compressed air compressors 12 for distributing a pre-compressed air flow to the respective compressed air compressors 12. The manifold 50 may be arranged downstream of the cooling device 48 or arranged between the pressure-boosting apparatus 14 and the respective compressed air compressors 12 and/or between the cooling device 48 and the respective compressed air compressors 12. The manifold 50 may also be configured as a component of the housing 30 for the pressure-boosting apparatus 14 or be integrally connected to the housing 30 for the pressure-boosting apparatus 14 or be formed in one piece.

As may be seen from FIG. 1, the compressed air system 10 may also be equipped with a common blow-off valve 52. The common blow-off valve 52 may be arranged downstream of at least some or all of the compressed air compressors 12 for reducing the pressure on the consumer side. The common blow-off valve 52 may be configured in particular as a control valve. The common blow-off valve 52 may also be controlled and/or regulated by the control and/or regulating device 18.

The control and/or regulating device 18 may also be configured to control and/or regulate the blow-off valve 52 based on a consumer-side setpoint pressure and/or actual pressure. The control and/or regulating device 18 may also be configured to control and/or regulate a consumer-side actual pressure to a constant minimum pressure by means of the common blow-off valve 52.

As already explained above, an actual pressure on the consumer side may be detected by the control and/or regulating device 18, for example in a pipe section 20. The control and/or regulating device 18 may also be set up to control and/or regulate the blow-off valve 52 based on a target/actual comparison of a consumer-side pressure, especially a target/actual comparison of a consumer-side pressure in the line section 20.

FIG. 2 shows a compressed air system 10 according to another embodiment of the present invention. The embodiment shown in FIG. 2 differs from the embodiment of FIG. 1 in terms of the configuration downstream of the compressed air compressors 12. Therefore, the area of the compressed air system 10 upstream of the compressed air compressors 12 is not shown in detail in FIG. 2.

The compressed air system 10 shown in FIG. 2 is equipped with at least one expansion turbine 54. The expansion turbine 54 may be arranged downstream of the common outlet valve 52. Exhausted compressed air may be fed to the expansion turbine 54 via the outlet valve 52. The expansion turbine 54 may also be connected to a generator 56 for power generation. Excess compressed air may therefore be blown out via the common blow-off valve 52 and fed to the expansion turbine 54, which may drive the generator 56 to generate electricity.

A supply valve 58 for the supply of compressed air to the expansion turbine 54 may also be arranged between the common outlet valve 52 and the expansion turbine 54. The supply valve 58 may be configured as a switching valve and/or an ON/OFF valve. Such a switching valve or ON/OFF valve may be switched between a fully open and a fully closed position, whereby it is not possible for it to remain in intermediate positions. If the supply valve 58 is switched to an OPEN position, the compressed air supply to the expansion turbine 54 may be regulated via the regulated or controlled blow-off valve 52.

The compressed air system 10 may also have an outlet valve 60 as shown in FIG. 2, which is arranged downstream of some or all of the compressed air compressors 12 for discharging compressed air into the atmosphere. The outlet valve 60 may also be configured as a switching valve and/or an ON/OFF valve. If the outlet valve 60 is switched to an OPEN position, the regulated discharge of compressed air into the atmosphere may be carried out via the regulated or controlled blow-off valve 52. For this purpose, the outlet valve 60 may be arranged downstream of the common blow-off valve 52.

The compressed air system 10 according to FIG. 2 may also have a buffer storage 62 for storing compressed air. The buffer storage 62 may be arranged downstream of the common blow-off valve 52. Compressed air blown out via the common blow-off valve 52 may be fed to the buffer storage 62. Furthermore, according to the embodiment shown in FIG. 2, a pneumatic pressure intensifier 64 for increasing the pressure of the compressed air blown into the buffer storage 62 may be arranged upstream of the buffer storage 62. For this purpose, the pneumatic pressure intensifier 64 may be arranged downstream of the common outlet valve 52, i.e. arranged between the common outlet valve 52 and the buffer storage 62.

As may also be seen in FIG. 2, an infeed valve 66 for the supply of compressed air to the consumer side may be arranged downstream of the buffer storage 62. Based on the operating situation of the compressed air system 10, compressed air stored in the buffer storage 62 may be fed via the infeed valve 66 into the consumer-side line section 20. The infeed valve 66 may be configured as a switching valve and/or an ON/OFF valve. The infeed valve 66 may also be configured as a regulated or controlled valve, and thus also be configured for adjustment to intermediate positions between a fully open and fully closed position.

The control and/or regulating device 18 may be configured to control and/or regulate the outlet valve 60 and/or the supply valve 58 and/or the infeed valve 66. The control and/or regulating device 18 may therefore be configured to coordinate all valve positions and/or the operation of the compressed air compressors 12 and/or the pressure-boosting apparatus 14 not shown in detail in FIG. 2.

In particular, the control and/or regulating device 18 may be configured to control and/or regulate the outlet valve 60 and/or the supply valve 58 and/or the infeed valve 66 based on a consumer-side target pressure and/or actual pressure and/or based on a target/actual comparison of the consumer-side pressure. The control and/or regulating device 18 may be configured in particular to control and/or regulate an actual pressure on the consumer side to a constant minimum pressure by means of the outlet valve 60 and/or the supply valve 58 and/or the infeed valve 66.

FIG. 3 shows a compressed air system 10 according to a further embodiment of the present invention. The embodiment shown in FIG. 3 differs from the embodiment shown in FIG. 2 in terms of the configuration or arrangement of the expansion turbine 54. In FIG. 3, the area of the compressed air system 10 upstream of the compressed air compressors 12 is shown in more detail, as in FIG. 1.

In the embodiment of the compressed air system 10 according to FIG. 3, the expansion turbine 54 is connected to the drive motor 24 for the pressure-boosting apparatus 14. An intermediate gearbox 68 may be provided between the drive motor 24 and the expansion turbine 54. In addition or alternatively, a freewheel device, not shown in detail here, may be provided between the drive motor 24 and the expansion turbine 54.

In the embodiment shown in FIG. 3, excess compressed air may be fed to the expansion turbine 54 via the common outlet valve 52 and the supply valve 58. The expansion turbine 54 may drive the drive motor 24 via the gearbox 68 and/or via the freewheel device, which is not shown in detail. This enables energy-saving operation of the pressure-boosting apparatus 14, since energy from excess compressed air may be configured to drive the pressure-boosting apparatus 14.

FIG. 4 shows a compressed air system 10 according to a further embodiment of the present invention. The embodiment shown in FIG. 4 differs from the embodiments of FIGS. 2 and 3 in terms of the configuration or arrangement of the expansion turbine 54. In FIG. 4, the area of the compressed air system 10 upstream of the compressed air compressors 12 is shown in more detail, as in FIGS. 1 and 3.

In the embodiment according to FIG. 4, no pressure-boosting apparatus is shown. However, the embodiment shown in FIG. 4 may also be equipped with a pressure-boosting apparatus as shown in FIGS. 1 and 3.

In the embodiment of the compressed air system 10 according to FIG. 4, the expansion turbine 54 is connected to at least one drive motor 70 for a compressed air compressor 12. In particular, according to FIG. 4, a plurality of expansion turbines 54 may be provided, each of which is connected to a drive motor 70 for a compressed air compressor 12. An intermediate gearbox 68 may be provided between the drive motor 70 of the respective compressed air compressor 12 and the respective expansion turbine 54. In addition or alternatively, a freewheel device, not shown in detail here, may be provided between the drive motor 70 of the respective expansion turbine 54 and the respective expansion turbine 54. A separate supply valve 58 may be provided for each of the expansion turbines 54, via which compressed air may be fed to the respective expansion turbine 54.

In the embodiment shown in FIG. 4, excess compressed air may therefore be fed via the common outlet valve 52 and via the respective supply valve 58 to the downstream expansion turbine 54. The expansion turbine 54 may drive the drive motor 70 of the respective compressed air compressor 12 via a gearbox 68 and/or via a freewheel device not shown in detail. This enables energy-saving operation of the respective compressed air compressors 12, since energy from excess compressed air may be configured to drive the compressed air compressors 12.

In individual or all embodiments of the compressed air system 10 according to FIGS. 1 to 4, at least some or all of the compressed air compressors 12 may be configured as unregulated fixed compressors. Fixed compressors within the meaning of the present invention may either be switched on or off and, when switched on, may be operated at a predetermined power.

It is also possible that at least one of the compressed air compressors 12 is configured as a regulated compressed air compressor 12, in particular that a plurality of compressed air compressors 12 are configured as regulated compressed air compressors 12. Within the meaning of the present invention, regulated compressed air compressors 12 may be set to different power levels when switched on, so that different delivery capacities may be achieved. The control range of a controlled compressed air compressor 12 may be greater than the delivery capacity of another compressed air compressor 12 or a fixed compressor, in particular greater than the delivery capacity of a compressed air compressor 12 or fixed compressor with the largest delivery capacity.

In individual or all embodiments according to FIGS. 1 to 4, the control and/or regulating device 18 may be configured to control and/or regulate a consumer-side actual pressure free of a pressure band to a constant minimum pressure.

Furthermore, in individual or all embodiments according to FIGS. 1 to 4, the control and/or regulating device 18 may be configured to switching off and/or switching on one or more compressed air compressors 12 and/or controlling and/or regulating their operating state, in particular the delivery capacity, based on a consumer-side setpoint pressure and/or actual pressure and/or based on a setpoint/actual comparison of a consumer-side pressure. The control and/or regulating device 18 may also be configured to generate a variable adjustment of the pre-pressure for at least some or all of the compressed air compressors 12 by means of the pressure-boosting apparatus 14 when one or more compressed air compressors 12 are switched on and/or off.

A control and/or regulation range achieved by means of the pressure-boosting apparatus 14 may be greater than the delivery capacity of at least one compressed air compressor 12, in particular the compressed air compressor 12 or fixed compressor with the largest delivery capacity.

Finally, in individual or all embodiments according to FIGS. 1 to 4, the common blow-off valve 52 and/or the outlet valve 60 may be configured and/or dimensioned to blow out the delivery capacity of at least one of the compressed air compressors 12, in particular the compressed air compressor 12 or fixed compressor with the largest delivery capacity, preferably with a margin of at least 10%, at least 20%, at least 30% or more than 30%.

The compressed air compressors 12 may be, for example, piston compressors, screw compressors, lamella compressors, centrifugal compressors, diaphragm compressors or scroll compressors. The compressed air systems 10 described above may also have different types of compressed air compressors 12.

The compressed air system 10 described above enables significant energy savings to be achieved, for example energy savings of over 10%. There are significantly fewer switchings for operating the compressed air compressors 12, which has a positive effect on maintenance costs. Pre-compression by means of the pressure-boosting apparatus 14 makes it possible to specifically influence the delivery capacity of the compressed air compressors 12 without switching individual compressed air compressors 12 on or off or changing their delivery capacity or operating rotational speed.

FIG. 5 shows a compressed air system 10 according to a further embodiment of the present invention. The embodiment shown in FIG. 5 differs from the embodiments shown in FIGS. 2 to 4 in terms of the configuration or arrangement of the expansion turbine 54, the supply valve 58 and the blow-off valve 52. FIG. 5 shows the area of the compressed air system 10 downstream of the compressed air compressors 12 in more detail.

In the embodiment according to FIG. 5, no pressure-boosting apparatus is shown. However, the embodiment shown in FIG. 5 can also be equipped with a pressure-boosting apparatus as shown in FIGS. 1 and 3. Similarly, the embodiment according to FIG. 5 may be configured without a pressure-boosting apparatus.

In the embodiment of the compressed air system 10 according to FIG. 5, the expansion turbine 54 may be connected to at least one drive motor of a compressed air compressor 12, which is not shown in detail here, or a direct mechanical coupling may be provided between the expansion turbine 54 and a drive component of at least one compressed air compressor 12.

In the embodiment according to FIG. 5, the supply valve 58 and the outlet valve 52 may be connected in parallel. In the embodiment according to FIG. 5, excess compressed air may therefore be exhausted via the common outlet valve 52 and fed in parallel to the downstream expansion turbine 54 via the supply valve 58.

FIG. 5 shows the control and/or regulating device 18 in more detail. The control and/or regulating device 18 may preferably be configured as a programmable logic controller (PLC) and/or as a process control system (PCS). The control and/or regulating device 18 may have a logic 72 and/or a valve control 74 for controlling the blow-off valve 52. The valve control 74 may control the blow-off valve 52 based on a consumer-side pressure in the line section 20.

A pressure sensing device 73, which may in particular be a PD transmitter, may be provided to detect the consumer-side pressure in the line section 20. The pressure sensing device 73 may transmit a detected pressure to the control and/or regulating device 18.

Furthermore, according to the embodiment shown in FIG. 5, a valve control 75 may be provided for controlling the supply valve 58. The valve control 75 may control the supply valve 58 based on a pressure and/or a temperature downstream and/or within the expansion turbine 54. The valve control 75 may, in particular, control the supply valve 58 based on a minimum temperature downstream and/or within the expansion turbine 54, particularly preferably based on icing downstream and/or within the expansion turbine 54.

A selection circuit 77 may be disposed between the valve control 75 and the supply valve 58. The supply valve 58 may also be controlled by the control 74 via the selection circuit 77. In this case, the valve control 74 may control the supply valve 58 based on a consumer-side pressure in the line section 20.

FIG. 6 shows a compressed air system 10 according to a further embodiment of the present invention. In the embodiment of FIG. 6, at least one of the compressed air compressors 12 is configured as a regulated compressed air compressor 12a, as also described above with reference to the embodiments of FIGS. 1 to 4. For this purpose, FIG. 6 illustrates in more detail the area of the compressed air system 10 located downstream of the compressed air compressors 12.

In the embodiment shown in FIG. 6, no pressure-boosting apparatus is depicted. However, the embodiment may also be equipped with a pressure-boosting apparatus as shown in FIGS. 1 and 3. Similarly, the embodiment shown in FIG. 6 may be configured without a pressure-boosting apparatus.

In the embodiment of the compressed air system 10 according to FIG. 6, a plurality of compressed air compressors 12 are provided, which are configured as fixed compressors 12b. In addition, at least one regulated compressed air compressor 12a is provided. In this embodiment, the control and/or regulating device 18 may be configured in particular to switch at least one compressed air compressor 12 configured as a fixed compressor 12b, in particular to switch it on or off, based on a rotational speed and/or an operating state of the regulated compressed air compressor 12a.

Furthermore, the control and/or regulating device 18 may comprise a controller 76 for operating the regulated compressed air compressor 12a. The regulated compressed air compressor 12a may be operated via the controller 76, in particular based on a consumer-side pressure in the line section 20. In certain embodiments, the regulated compressed air compressor 12a may be implemented as a variable speed drive (VSD) compressor.

FIG. 7 shows a compressed air system 10 according to a further embodiment of the present invention. The embodiment according to FIG. 7 corresponds to the embodiment in FIG. 7, wherein the area of the compressed air system 10 upstream of the compressed air compressors 12 is also shown in more detail.

In the embodiment shown in FIG. 7, a bird guard 34, an intake filter 32, a cooling device 48 and a manifold 50 may be provided. No pressure-boosting apparatus is shown in FIG. 7. However, the embodiment shown in FIG. 7 may also be equipped with a pressure-boosting apparatus, as described in more detail below with reference to FIG. 8. Similarly, the embodiment according to FIG. 7 may be configured without a pressure-boosting apparatus.

FIG. 8 shows a compressed air system 10 according to a further embodiment of the present invention. The embodiment according to FIG. 8 differs from the embodiment shown in FIG. 7 in the arrangement of the pressure-boosting apparatus 14. The pressure-boosting apparatus 14 corresponds to the configuration according to the embodiments in FIGS. 1 and 3. The control and/or regulating device 18 according to the embodiment shown in FIG. 8 may be configured to control and/or regulate the pressure-boosting apparatus 14 based on a rotational speed and/or an operating state of the regulated compressed air compressor 12a, in particular to control and/or regulate the generation of a variable pre-pressure. For this purpose, the control and/or regulating device 18 may have a control 76 which is configured to control the regulated compressed air compressor 12a and also to control the pressure-boosting apparatus 14, in particular the motor 28 of the pressure-boosting apparatus 14.

FIG. 9 shows a compressed air system 10 according to a further embodiment of the present invention. The embodiment shown in FIG. 9 differs from the embodiment of FIG. 5 in terms of the configuration or arrangement of the expansion turbine 54. In FIG. 9, the area of the compressed air system 10 downstream of the compressed air compressors 12 is shown in more detail.

In the embodiment according to FIG. 9, no pressure-boosting apparatus is shown. However, the embodiment shown in FIG. 9 may also be equipped with a pressure-boosting apparatus as shown in FIGS. 1 and 3. Similarly, the embodiment according to FIG. 9 may be configured without a pressure-boosting apparatus.

In the embodiment shown in FIG. 9, the expansion turbine 54 may be connected to at least one drive motor for a compressed air compressor 12, or a direct mechanical coupling may be provided between the expansion turbine 54 and a drive component of at least one compressed air compressor 12. In addition, the expansion turbine 54 may be connected, preferably in the form of a spur gear, and/or the drive motor 28, in particular through a gearbox 78, and/or the drive motor 28, in particular through a gearbox 78, to a drive motor 28 of a pressure-boosting apparatus 14 via a coupling 80. This enables overall efficient operation of the compressed air system 10.

Furthermore, in the embodiment shown in FIG. 10, an exhaust-air recirculation 82 of the compressed air expanded by the expansion turbine 54 may be provided. The exhaust-air recirculation 82 enables the compressed air expanded by the expansion turbine 54 to be fed to at least one of the compressed air compressors 12.

FIG. 10 shows a compressed air system 10 according to a further embodiment of the present invention. The embodiment shown in FIG. 10 differs from the embodiment shown in FIG. 2 in terms of the configuration or arrangement of the buffer storage 62. In FIG. 10, the area of the compressed air system 10 downstream of the compressed air compressors 12 is shown in more detail for this purpose.

In the embodiment according to FIG. 10, no pressure-boosting apparatus is shown. However, the embodiment shown in FIG. 10 may also be equipped with a pressure-boosting apparatus as shown in FIGS. 1 and 3. Similarly, the embodiment according to FIG. 10 may be configured without a pressure-boosting apparatus.

In the embodiment shown in FIG. 10, the buffer storage storage 62 may be connected via a pneumatic pressure intensifier 64 to the line section 20 in which an actual pressure on the consumer side is present. The buffer storage storage 62 may therefore be filled via the pneumatic pressure intensifier 64. Furthermore, an infeed valve 66 is provided, from which compressed air from the buffer storage 62 may be fed in parallel to the line section 20 to a consumer with fluctuating demand or with peak demand. Compressed air may also be fed back from the buffer storage 62 to the line section 20 via the infeed valve 66.

Regardless of the opening position of the infeed valve 66, compressed air may also be fed directly from the line section 20 with the actual pressure on the consumer side parallel to the power section to a consumer with fluctuating demand or peak demand, namely via a bypass pipe through which the buffer storage 62, the pneumatic pressure intensifier 64 and the infeed valve 66 are bypassed.

In the embodiment shown in FIG. 10, the control and/or regulating device 18 may be configured to switch at least one compressed air compressor 12, configured as a fixed compressor 12b, based on the position of the infeed valve, in particular to switch it on or off. Similarly, the control and/or regulating device 18 in the embodiment according to FIG. 10 may be configured to switch at least one compressed air compressor 12 configured as a fixed compressor 12, in particular to switch it on or off, based on an actual pressure on the consumer side in the line section 20. Finally, the control and/or regulating device 18 in the embodiment according to FIG. 10 may be set up to set the position of the infeed valve 66 based on the operation of at least one compressed air compressor 12 and/or based on an actual pressure on the consumer side in the line section 20, especially to open or close it.

A compressed air system 10 as described above may be implemented either by completely new installation or by retrofitting individual system components, thereby improving the energy and operating efficiency of existing compressed air systems.