DE102022109705A1 - Compressor-expander system and method of operating same - Google Patents

Abstract

Compressor-expander system (10), with a compressor (12) that can be driven by an electric machine (11) and is set up to suck in air to be compressed from an environment, with a first heat exchanger (13) arranged downstream of the compressor (12). ), which is set up to transfer thermal energy from the air compressed in the compressor (12) to a storage medium, with a second heat exchanger (14) arranged upstream of the compressor (12), which is set up to transfer thermal energy from the above to transfer compressed air guided through the first heat exchanger (13) to the air to be compressed in the compressor, and with an expander (15) which is set up to convey compressed air through the first heat exchanger (13) and via the second heat exchanger (14). To relax air and release it into the environment. The second heat exchanger (14) has several heat pipes connected in series, namely several heat pipes (17) connected in series or several two-phase thermosiphons connected in series. Alternatively or additionally, a heating device (21) is connected between the compressor (12) and the first heat exchanger (13), which is set up to heat the air compressed in the compressor upstream of the first heat exchanger (13).

Description

The invention relates to a compressor-expander system and a method for operating such a system.

DE 10 2019 133 904 A1 discloses a compressor-expander system with a compressor that can be driven by an electric machine and with an expander coupled to the compressor, wherein air can be sucked in from an environment via the compressor in order to compress the air, and wherein air compressed via the expander expands and can be discharged into the environment. The compressor-expander system disclosed there also has a first heat exchanger, viewed in the flow direction of the air to be compressed, arranged downstream of the compressor in order to extract heat from the compressed air and to transfer thermal energy to a storage medium. Furthermore, a second heat exchanger is provided upstream of the compressor, which is set up to transfer thermal energy from the air guided and compressed over the first heat exchanger to the air to be compressed in the compressor.

Although it's with the one from the DE 10 2019 133 904 A1 Known compressor-expander system is already possible, for example in a power plant to use excess electrical energy to increase efficiency, there is a need to operate a compressor-expander system even more efficiently.

Proceeding from this, the present invention is based on the object of creating a novel compressor-expander system and a method for operating such a system, which has high efficiency.

According to a first aspect of the invention, this object is achieved by a compressor-expander system according to claim 1. According to this, the second heat exchanger has several heat pipes connected in series, namely several heat pipes connected in series or several two-phase thermosiphons connected in series.

According to the first aspect of the invention, the second heat exchanger comprises a plurality of heat pipes connected in series. The heat pipes are preferably heat pipes. This makes it possible to provide a particularly efficient compressor-expander system. A particularly efficient heat transfer can be provided in the area of the second heat exchanger.

This object is achieved according to a second aspect of the invention by a compressor-expander system according to claim 3. Thereafter, a heating device is connected between the compressor and the first heat exchanger, which is set up to heat the air compressed in the compressor upstream of the first heat exchanger.

With the second aspect of the invention, the efficiency of the compressor-expander system can also be increased. If there is not enough electrical energy available to drive the compressor, downtimes can be bridged particularly advantageously using the heating device.

Both aspects are preferably used in combination with one another. When both aspects are used in combination on a compressor-expander system, efficiency can be increased in a particularly advantageous way.

A bypass to the compressor is preferably provided in order to supply uncompressed air past the compressor to a heating device designed as a burner. A switching valve is then preferably further provided, which is set up to either lead compressed air guided via the first heat exchanger and via the second heat exchanger via the expander or to discharge it into the environment via a chimney. A fan is preferably provided upstream of the first heat exchanger.

A fired burner is typically operated without pressure. In this case, the compressor of the compressor-expander system works either as a fan and supplies combustion air to the burner without pressure. Alternatively, the combustion air is supplied to the burner via the fan, bypassing the compressor. In this case, the expander is preferably not flowed through, but rather the air is preferably drained away via the chimney. This is done via the switching valve.

A condensate separator is preferably assigned to at least one stage of the expander, and/or a further heat exchanger is connected between at least two stages of the expander and is set up to heat the partially relaxed air. Using the condensate separator, it is possible to remove moisture from the relaxed or partially relaxed air and to counteract the formation of ice.

Preferably, a cold extraction device is provided downstream of the expander, which is set up to extract cold from the relaxed air. This makes it possible to extract usable cold from the relaxed air to further increase the efficiency of the compressor expander system.

The method according to the invention for operating the compressor-expander system according to the invention is defined in claim 11.

• 1: ein erstes erfindungsgemäßes Verdichter-Expander-System,
• 2: ein zweites erfindungsgemäßes Verdichter-Expander-System,
• 3: ein drittes erfindungsgemäßes Verdichter-Expander-System,
• 4: ein viertes erfindungsgemäßes Verdichter-Expander-System,
• 5: ein fünftes erfindungsgemäßes Verdichter-Expander-System,
• 6: ein sechstes erfindungsgemäßes Verdichter-Expander-System,
• 7 ein weiteres erfindungsgemäßes Verdichter-Expander-System,
• 8: ein Detail des Verdichter-Expander-Systems nach 1, 3, 4, 5, 6und 7,
• 9: ein P-h-Diagramm zur Verdeutlichung der Erfindung.

Preferred developments of the invention result from the subclaims and the following description. Exemplary embodiments of the invention are explained in more detail using the drawing, without being limited to this. This shows:

• 1 : a first compressor-expander system according to the invention,
• 2 : a second compressor-expander system according to the invention,
• 3 : a third compressor-expander system according to the invention,
• 4 : a fourth compressor-expander system according to the invention,
• 5 : a fifth compressor-expander system according to the invention,
• 6 : a sixth compressor-expander system according to the invention,
• 7 another compressor-expander system according to the invention,
• 8th : a detail of the compressor expander system 1 , 3 , 4 , 5 , 6and 7 ,
• 9 : a Ph diagram to illustrate the invention.

1 shows a compressor-expander system 10 according to a first aspect of the present invention. The compressor-expander system 10 has a compressor 12 that can be driven by an electric machine 11 and is set up to suck in air LU1 to be compressed from an environment.

The compressor-expander system 10 has a first heat exchanger 13 downstream of the compressor 12, which is set up to transfer thermal energy from the air LV compressed in the compressor to a storage medium SM. The storage medium SM can be, for example, liquid salt or thermal oil or the like.

The compressor-expander system 10 has a second heat exchanger 14 upstream of the compressor 12.

On the one hand, the compressed air LV conducted in the compressor 12 and via the first heat exchanger 13 and, on the other hand, the air LU1 to be compressed in the compressor 12 can be conducted via the heat exchanger 14. The compressor 12 can be single-stage or multi-stage.

This second heat exchanger 14 is set up to transfer thermal energy from the compressed air LV guided via the first heat exchanger 13 to the air LU1 to be compressed in the compressor.

The air LU1 to be compressed can be sucked in via a silencer and/or air filter. Silencer and/or air filters are preferably arranged upstream of the compressor 12, in particular upstream of the second heat exchanger 14.

The compressor-expander system 10 also has an expander 15. The expander 15 is set up to expand compressed air LV guided via the first heat exchanger 13 and the second heat exchanger 14 and to discharge it into the environment as relaxed air LU2.

As already stated, the compressor 12 can be driven by the electrical machine 11, for example to use excess electrical energy. Compressor 12 and expander 15 are coupled via a shaft 16. A clutch can be installed between compressor 12 and expander 15 (see 7 ) and/or a gearbox. When the air LV1 is expanded in the expander 15, the mechanical energy generated can be used to drive the compressor. A silencer can be arranged downstream of the expander 15.

According to the first aspect of the invention, the second heat exchanger 14 comprises a plurality of heat pipes connected in series, which are designed as heat pipes 17 in the exemplary embodiment shown.

Alternatively, the heat pipes can also be two-phase thermosiphons.

8th shows the second heat exchanger 14 with several heat pipes 17 in greater detail. The heat pipes 17 are connected in series.

The heat transfer from the compressed air LV1 into the air to be compressed LU1 is accomplished via the several series-connected heat pipes 17. A very efficient heat transfer is possible via such heat pipes 17.

Heat pipes are pipes filled with a refrigerant, for example water can be used as the refrigerant. On On the hot side, i.e. in the area of compressed air LV1, the refrigerant is evaporated.

The evaporated refrigerant rises in the heat pipes 17 and releases heat as condensation energy in the upper area to the air LU1 to be compressed. In the upper area, the respective heat pipe 17 is filled with gas.

An air duct 18 carrying the compressed, hot air LV is positioned below the air duct 19 carrying the cold air LU1 to be compressed.

Outer sides of the heat pipes 17 are equipped with fins 20 for better heat transfer between the heat pipes 17 and the respective air LV, LU1.

2 shows a compressor-expander system 10 according to a second aspect of the invention, in which the same reference numbers are used for the same assemblies to avoid unnecessary repetition, as in 1 . The details that make up the compressor-expander system 10 will be discussed below 2 from the compressor expander system 10 of the 1 differs.

In the exemplary embodiment 2 the second heat exchanger 17 is not formed by several series-connected heat pipes, in particular heat pipes 17, but rather by a conventional heat exchanger.

According to the second aspect of the invention, it is provided that a heating device 21 is connected between the compressor 12 of the compressor-expander system 10 and the first heat exchanger 13. The heating device 21 is set up to heat the air LV1 compressed in the compressor 12 upstream of the first heat exchanger 13.

In the exemplary embodiment 2 the heating device 21 is designed as a burner. With such a burner 13, for example, if there is not enough electrical energy available to drive the compressor 12 via the electrical machine 11, the operation of the compressor-expander system 10 can be maintained.

This is in 2 the heating device 21 designed as a burner is integrated into an air duct extending between the compressor 12 and the first heat exchanger 13; the burner is then a so-called duct burner.

The burner generates a temperature rise, which occurs in normal operation via the compression in the compressor 12.

The heating device 21 designed as a burner is used without pressure. In this case, the compressor 12 either works as a fan or is at a standstill. A bypass 22 is preferably present, which is set up to lead air LU1 from the environment past the compressor 12 in the direction of the heating device 21 designed as a burner.

Then, when the compressor-expander system 10 has the heating device 21 designed as a burner, the compressor-expander system 10 preferably also has a switching valve 23 in an air duct extending from the first heat exchanger 13 in the direction of the expander 15.

Depending on the switching position of this switching valve 23, the air guided and compressed via the first heat exchanger 13 can either be guided via the expander 15 or discharged into a chimney 24. If the heating device 21 designed as a burner is operated, the air LV1 is preferably diverted into the chimney 24 via the switching valve 23 and is not guided via the expander 15.

As soon as the control valve 23 opens the connection to the chimney 24, there is no longer any back pressure in the compressor-expander system 10 and the system 10 with the heating device 21 designed as a burner is operated atmospherically or approximately atmospherically.

2 shows another switching valve 25. This is integrated into the air line running between the compressor 12 and the first heat exchanger 13. Depending on the switching position of this switching valve 25, the bypass 22 is either released or closed.

2 also shows a fan 26. In the event that the air cannot be guided over the compressor 12 when using the heating device 21 designed as a burner, the fan 26 can ensure sufficient air flow to the burner.

3 shows a compressor-expander system 10, which has the aspects of 1 and 2 combined with each other, in which the second heat exchanger 14 has several heat pipes connected in series, namely several heat pipes 17 or two-phase thermosiphons connected in series, and in which a heat exchanger is located between the compressor 12 and the first heat exchanger 13 tongue device 21 is connected, which is set up to heat the air compressed in the compressor 12 upstream of the first heat exchanger 13.

Another compressor-expander system 10 according to the invention shows 4 . The compressor-expander system 10 of the 4 is a further development of the compressor expander system 10 1 , which is why the same reference numbers are used for the same assemblies. The details that make up the exemplary embodiment will be discussed below 4 from the exemplary embodiment of 1 differs.

In the exemplary embodiment 4 is the same as in the exemplary embodiments 2 and 3 A heating device 21 is connected between the compressor 12 and the first heat exchanger 13, which, however, is not designed as a burner, but rather as an electric heater or conventional heat exchanger. It is thus possible to regulate the temperature of the air upstream of the first heat exchanger 13 to a target value.

In this way, heat can again be supplied to the compressed air LV after compression in the compressor 12. This may be necessary in order to achieve a higher temperature level upstream of the first heat exchanger 13 than immediately at the outlet of the compressor 12.

Another difference in the exemplary embodiment 4 compared to the exemplary embodiment 1 is that in the exemplary embodiment the 4 the expander 15 has two expander stages 15a and 15b. A further heat exchanger 27 is connected between the two expander stages 15a and 15b. The process can be supplied with waste heat or ambient heat between the two stages 15a and 15b of the expander 15. At the point between the two expander stages 15a and 15b, an additional heat supply via a heat pump or a heat supply from waste heat or ambient heat can also be provided in order to increase the efficiency of the expander 15 and/or to regulate the outlet temperature of the air downstream of the expander 15 . This can be done, for example, during defrosting at intervals or as a permanent temperature control. It is thus possible to regulate the temperature of the air downstream of the expander 15 to a target value.

Water contained in the air can lead to icing at the outlet of the expander 15 under certain operating conditions. In 4 A condensate separator 28 interacts with both stages 15a and 15b of the expander 15. Condensate can be removed via the respective condensate separator 28 in order to counteract ice formation at low temperatures.

In order to counteract icing or ice formation, other measures are also possible, which can be used in all exemplary embodiments. This makes it possible to regulate the outlet temperature at the expander 15 by adjusting the guide vane of the expander 15. Alternatively or additionally, components at risk from icing, such as an expander housing, diffuser, silencer and/or air duct, can be heated. Alternatively or additionally, after the expander 15 exits, a defrosting section and/or mixing chamber can be provided in order to separate ice, thaw it again and/or, if necessary, mix in warm air.

Alternatively, ice formation can be allowed and defrosting can be carried out at intervals.

In the exemplary embodiment 4 A cold extraction device 29 is provided downstream of the expander 15. Via the cold extraction device 29, cold can be extracted from the relaxed air before it is discharged into the environment. The cold extraction device 29 is a heat exchanger which is set up to extract usable cold from the expanded air in the expander 15.

Furthermore, in 4 A heat exchanger 30 is provided upstream of the second heat exchanger 14 in order to supply heat to the air upstream of the second heat exchanger 14. This allows heat to be supplied to the air at the process inlet. It is thus possible to regulate the temperature of the air at the process inlet, i.e. upstream of the second heat exchanger 14, to a target value.

5 shows a modification of the compressor-expander system 10 of 1 , in which the first heat exchanger 13 is part of a heat storage system 31, which is integrated into the compressor-expander system 10 downstream of the compressor 12. In 5 the heat is extracted directly into the heat storage system 31, which includes the first heat exchanger 13 and a heat storage 32.

The heat storage 32 is preferably designed as a solid heat storage made of concrete, volcanic rock, fill, etc. In such a sensitive solid heat storage, the solid storage material is interspersed with tubes. The solid storage material is heated and cooled via the media in the pipes. The heat storage in and out of the heat storage 32 can also be done directly from the air onto the solid storage material occur when process air flows through the bed.

The solid storage material is heated to store thermal energy via the air LV compressed in the compressor 12. The solid storage material is cooled to store thermal energy via a useful medium NM. The useful medium NM can be steam, air, thermal oil or the like. Useful heat can be extracted via the useful medium NM in a temperature range between, in particular, 100°C and 400°C

In 5 Two separate pipe systems are shown for the heat storage 32, a pipe system for the air LV compressed in the compressor 12 for storing thermal energy and a pipe system for the useful medium NM for storing thermal energy. Also conceivable is or are a single pipe system exclusively for the air LV or three pipe systems, a pipe system for the air LV for heat storage and two further pipe systems for heat storage and heat extraction.

The heat storage 32 can also be designed as a latent heat storage, with a storage material such as a salt, metal or the like, which completes a phase transition at a constant temperature in a temperature range between, in particular, 100 ° C and 300 ° C.

6 shows a further development of the compressor expander system 10 5 , in which just like the compressor-expander systems 10 of 2 and 3 Between the compressor 12 and the first heat exchanger 13 or the heat storage system 31 having the first heat exchanger 13, the heating device 21 is connected, which is designed as a burner. Furthermore, the compressor-expander system 10 has 6 in the air duct extending from the first heat exchanger 13 or from the heat storage system 31 having the first heat exchanger 13 in the direction of the expander 15, the switching valve 23 opens.

In conjunction with the heating device 21 designed as a burner, a backup can be provided to ensure the heat supply to the heat storage system 31 in the event of a power shortage. When using the burner, the process is approximately atmospheric; the supply air is preferably supplied via the compressor 12 at idle, alternatively via a compressor 12 with bypass 22 and fan 26 in the same way 2 and 3 . During burner operation, the exhaust gas is diverted in front of the expander 15 via the switching valve 23 or a flap to the chimney 24.

7 shows a further development of the compressor expander system 10 5 or 6 . That's how it is 7 A clutch 33 is connected between the compressor 12 and the expander 15 in the shaft 16. The first heat exchanger 13 is designed as a bulk material storage. Furthermore shows 7 a further heat exchanger 34, further switching valves 35, 36 and 39, an optional heating device 37 and an optional filter 38. With the compressor-expander system 10 of 7 Different operating modes can be advantageously provided.

In a first operating mode of the compressor-expander system 10 the 7 , which corresponds to a first heat pump operation, heat can advantageously be stored in the storage medium SM or bulk material of the bulk material storage via the first heat exchanger 13, which is designed as a bulk material storage. Here, the switching valve 35 is opened so that the outlet of the compressor 12 is connected to a hot side of the bulk material storage, which is in 7 is shown above. In 7 The optional heating device 37, which is designed as an electric heater or conventional heat exchanger, is connected between the compressor 12 and the switching valve 35. The switching valve 36 then connects a cold side of the bulk material storage, which is in 7 is shown below, with the second heat exchanger 14, which has the heat pipes 17. The switching valve 36 closes an outlet side of the further heat exchanger 34, which is then not flowed through. The switching valve 39 is then closed. The switching valve 23 then connects the second heat exchanger 14 to the expander 15, and the connection to the chimney 24 is then closed.

In a second operating mode of the compressor-expander system 10 the 7 , which corresponds to a second heat pump operation, heat is used directly. In this case, the switching valve 35 is opened so that the outlet of the compressor 12 is connected to an inlet side of the further heat exchanger 34. The switching valve 36 then connects the outlet side of another heat exchanger 34, which is in particular a steam generator, with the second heat exchanger 14, which has the heat pipes 17. The switching valve 36 then blocks the cold side of the bulk material storage. The first heat exchanger 13, designed as a bulk material storage, is then not flowed through. The switching valve 39 is then closed. The switching valve 23 then connects the second heat exchanger 14 to the expander 15, and the connection to the chimney 24 is then closed.

By controlling the switching valve 36, the first operating mode and the second operating mode can also be used simultaneously in a mixed operation.

In a third operating mode of the compressor-expander system 10 the 7 Heat can advantageously be removed from the bulk material via the first heat exchanger 13. In this case, the compressor 12 works as a fan, the expander 15 is decoupled when the clutch 33 is open. In this case, the switching valve 35 is opened so that the outlet of the compressor 12 is connected to the cold side of the bulk material storage. The switching valve 36 then connects the outlet of the further heat exchanger 34 to the inlet of the compressor 12, the switching valve 39 then being opened. The second heat exchanger 14, which has the heat pipes 17, is bypassed and the air circulates in a circle. The switching valve 23 then preferably connects the second heat exchanger 14 to the expander 15, the connection to the chimney 24 is then closed, but this is not relevant for the third operating mode.

In a fourth operating mode of the compressor-expander system 10 the 7 , a so-called emergency operation, the compressor 12 again works as a fan, the expander 15 is decoupled when the clutch 33 is open. The heating device 21, designed as a burner, heats the air. In this case, the switching valve 35 is opened so that the outlet of the compressor 12 is connected to the cold side of the bulk material storage. The switching valve 36 then connects the outlet of the further heat exchanger 34 with the second heat exchanger 14, which has the heat pipes 17. The switching valve 39 is then closed. The switching valve 23 then connects the second heat exchanger 14 to the chimney 24, and the connection to the expander 15 is then closed. Exhaust gases that arise when the burner is in operation can be discharged into the chimney 24.

The first heat exchanger 34 is in 7 a bulk material storage in which the bulk material preferably contains concrete or gravel or rock.

The compressor-expander system 10 according to the invention is an open system which can be operated particularly efficiently. In particular, heat can be provided at a high temperature level in a temperature range between 200 °C and 600 °C. The invention is a power-to-heat application to convert excess electrical energy into heat and store it in a storage medium SM.

For the compressor expander system 10 1 shows 9 a pressure (P)-enthalpy (h) diagram, where 9 the open cycle process can be seen. The arrows of the 9 illustrate the heating of the uncompressed air LU1 in the second heat exchanger 14, the compression of the same in the compressor 12, the gradual cooling of the same in the area of the first heat exchanger 13 and the second heat exchanger 14 and the subsequent expansion of the same in the expander 15. The temperature level of the relaxed air in the The air LU2 derived from the environment is lower than the temperature level of the air LU1 that is sucked in from the environment and is to be compressed.

The invention further relates to a method for operating a compressor-expander system 10 according to the invention. The method relates in particular to the operation of the compressor-expander system 10 2 , 3 , in which the heating device 21 connected between the compressor 12 and the first heat exchanger 13 is designed as a burner. If the burner 21 is operated, air is preferably supplied to it via the bypass 22 and the compressed air is drained into the chimney 24 via the switching valve 23. However, if the burner is not operated, the bypass 22 is preferably closed, the compressor 12 is operated and the compressed air is fed to the expander 15 from the switching valve 23 downstream of the second heat exchanger 14.

Reference symbol list

10

Compressor expander system

11

electric machine

12

compressor

13

first heat exchanger

14

second heat exchanger

15

expander

15a

Expander stage

15b

Expander stage

16

Wave

17

Heatpipe

18

Air duct

19

Air duct

20

lamella

21

Heating device

22

bypass

23

switching valve

24

Chimney

25

switching valve

26

fan

27

Heat exchanger

28

Condensate separator

29

Cold extraction device

30

Heat exchanger

31

Heat storage system

32

Heat storage

33

coupling

34

Heat exchanger

35

switching valve

36

switching valve

QUOTES INCLUDED IN THE DESCRIPTION

This list of documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102019133904 A1 [0002, 0003]

Claims (11)

Compressor-expander system (10), with a compressor (12) that can be driven by an electric machine (11) and is set up to suck in air to be compressed from an environment, with a first heat exchanger (13) arranged downstream of the compressor (12). ), which is set up to transfer thermal energy from the air compressed in the compressor (12) to a storage medium, with a second heat exchanger (14) arranged upstream of the compressor (12), which is set up to transfer thermal energy from the above to transfer the compressed air guided by the first heat exchanger (13) to the air to be compressed in the compressor (12), with an expander (15) which is set up to be guided via the first heat exchanger (13) and via the second heat exchanger (14). to relax compressed air and discharge it into the environment, characterized in that the second heat exchanger (14) has several heat pipes connected in series, namely several heat pipes (17) connected in series or several two-phase thermosiphons connected in series. Compressor expander system (10). Claim 1 , characterized in that the same according to one of the Claims 3 until 7 is further trained. Compressor-expander system (10), with a compressor (12) that can be driven by an electric machine (11) and is set up to suck in air to be compressed from an environment, with a first heat exchanger (13) arranged downstream of the compressor (12). ), which is set up to transfer thermal energy from the air compressed in the compressor (12) to a storage medium, with a second heat exchanger (14) arranged upstream of the compressor (12), which is set up to transfer thermal energy from the above to transfer the compressed air guided by the first heat exchanger (13) to the air to be compressed in the compressor (12), with an expander (15) which is set up to be guided via the first heat exchanger (13) and via the second heat exchanger (14). to relax compressed air and discharge it into the environment, characterized in that a heating device (21) is connected between the compressor (12) and the first heat exchanger (13), which is set up to heat the air compressed in the compressor (12) upstream of the first heat exchanger (13). Compressor expander system (10). Claim 3 , characterized in that the heating device (21) is designed as a burner or as an electric heater or as a third heat exchanger. Compressor expander system (10). Claim 4 , characterized by a bypass (22) to the compressor (12) in order to supply uncompressed air past the compressor (12) to the heating device (21) designed as a burner, a switching valve (23) which is set up to operate via the first heat exchanger (13 ) and compressed air guided via the second heat exchanger (14) either via the expander (15) or discharged into the environment via a chimney (24). Compressor-expander system (10) according to one of the Claims 3 until 5 , thereby by a fan (26) upstream of the second heat exchanger (14). Compressor-expander system (10) according to one of the Claims 3 until 6 , marked that the same after Claim 1 is further trained. Compressor-expander system (10) according to one of the Claims 1 until 7 , characterized in that the expander (15) is designed in multiple stages, with a condensate separator (28) being assigned to at least one stage (15a) of the expander (15), and/or with a condensate separator (28) being assigned between at least two stages (15a, 15b) of the expander Another heat exchanger (27) is connected, which is set up to heat the partially relaxed air. Compressor-expander system (10) according to one of the Claims 1 until 8th , characterized by a cold extraction device (29) positioned downstream of the expander (15), which is set up to extract cold from the relaxed air. Compressor-expander system (10) according to one of the Claims 1 until 9 , characterized in that the first heat exchanger (13) is part of a heat storage system (31) which is integrated into the compressor-expander system (10) downstream of the compressor (12). Method for operating a compressor-expander system (10) at least according to Claim 5 , when the burner is in operation, the uncompressed air passes the compressor (12) via the bypass (22) in Rich The device is guided onto the burner and the compressed air guided via the first heat exchanger (13) and via the second heat exchanger (14) is passed into the chimney (24) via the switching valve (23). When the burner is not in operation, the air passes over the compressor (12) is guided in the direction of the burner and the compressed air guided via the first heat exchanger (13) and via the second heat exchanger (14) is conducted into the expander (15) via the switching valve (23).

Images