CN213392296U - Combined power generation system - Google Patents

Abstract

The utility model provides a cogeneration system, this cogeneration system include heat pump electricity storage system and power generation system. The heat pump electricity storage system is based on positive and negative Brayton cycle, the heat exchanger matched with the heat pump electricity storage system is arranged in the power generation system, and circulating working media in the power generation system can absorb heat of medium and low temperature gaseous working media in the heat pump electricity storage system, so that the power generation system can recover medium and low temperature residual heat of the heat pump electricity storage system caused by irreversible loss and then generate power. The combined power generation system for heat pump power storage and medium-low temperature waste heat power generation realizes clean and low-carbon combined energy storage power generation and efficient waste heat utilization, improves the power generation efficiency and the heat energy utilization efficiency, obviously increases the total amount of work and power generation of the combined power generation system, and can provide more electric power to the outside. Therefore, the embodiment of the utility model provides a combined power generation system has advantages such as generating efficiency is high, heat utilization rate is high, energy-concerving and environment-protective.

Description

Combined power generation system

Technical Field

The utility model belongs to the technical field of the power generation technique and specifically relates to a combined power generation system of heat pump accumulate and well low temperature waste heat power generation is related to.

Background

The heat pump electricity storage technology is an energy storage technology for storing and generating electricity by utilizing positive and negative Brayton cycle. In the energy storage stage, the compressor is driven by electric power such as valley electricity, renewable energy power and the like to drive the heat pump to circulate, so that electric energy is converted into heat energy and cold energy which are respectively stored in the heat storage medium and the cold storage medium; the heat engine cycle is adopted in the power generation stage, the stored heat energy and cold energy are converted into electric energy to be emitted, the method is suitable for energy storage systems of new energy power consumption, peak regulation, off-peak power utilization and the like, and the effects of improving the new energy power generation quality, shifting peaks and filling off-peaks, balancing power supply and demand, improving the power grid stability and the like can be achieved. However, in the heat pump electricity storage technology in the related art, due to various loss factors, the discharge (energy release) and charge (energy storage) processes are irreversible, so that the entropy of the system is increased and the surplus heat is generated, and the surplus heat is discharged out of the system as waste heat, so that the heat energy utilization efficiency is low.

SUMMERY OF THE UTILITY MODEL

The present invention aims at solving at least one of the technical problems in the related art to a certain extent. Therefore, the embodiment of the utility model provides a cogeneration system, generating efficiency is high, heat utilization rate is high, energy-concerving and environment-protective.

According to the utility model discloses a cogeneration system of embodiment includes: the heat pump electricity storage system comprises a high-temperature heat accumulator, a low-temperature heat accumulator, a compressor, a first turbine, a first conveying pipe and a second conveying pipe, wherein the first end of the first conveying pipe is connected with a working medium outlet of the compressor, the first end of the second conveying pipe is connected with the high-temperature heat accumulator, the high-temperature heat accumulator is connected with a working medium inlet of the first turbine, a working medium outlet of the first turbine is connected with the low-temperature heat accumulator, and the low-temperature heat accumulator is connected with a working medium inlet of the compressor; and the power generation system comprises a heat exchanger, a second turbine and a conveying device, the heat exchanger is provided with a heating working medium inlet, a heating working medium outlet, a heated working medium inlet and a heated working medium outlet, the second end of the first conveying pipe is communicated with the heating working medium inlet, the second end of the second conveying pipe is communicated with the heating working medium outlet, the working medium outlet of the conveying device is communicated with the heated working medium inlet, and the working medium inlet of the second turbine is communicated with the heated working medium outlet.

According to the utility model discloses combined power generation system includes the heat pump accumulate system based on positive contrary brayton cycle to through set up in power generation system with heat pump accumulate system complex heat exchanger, thereby make the circulation working medium among the power generation system can absorb the heat of well low temperature gaseous state working medium among the heat pump accumulate system, so that power generation system can retrieve the well low temperature waste heat quantity (generate electricity) that heat pump accumulate system leads to owing to irreversible loss. The combined power generation system for heat pump power storage and medium-low temperature waste heat power generation realizes clean and low-carbon combined energy storage power generation and efficient waste heat utilization, improves the power generation efficiency and the heat energy utilization efficiency, obviously increases the total amount of work and power generation of the combined power generation system, and can provide more electric power to the outside.

Therefore, the embodiment of the utility model provides a combined power generation system has advantages such as generating efficiency is high, heat utilization rate is high, energy-concerving and environment-protective.

In addition, according to the utility model discloses a combined power generation system still has following additional technical characterstic:

in some embodiments, the heat pump electric storage system further includes a third delivery pipe, the high temperature heat accumulator includes a first port and a second port, the low temperature heat accumulator includes a third port and a fourth port, a first end of the third delivery pipe is connected to the working medium outlet of the compressor, a second end of the third delivery pipe is connected to the first port, a second end of the second delivery pipe is connected to the second port, each of the first port and the second port is connected to the working medium inlet of the first turbine, each of the third port and the fourth port is connected to the working medium outlet of the first turbine, and each of the third port and the fourth port is connected to the working medium inlet of the compressor.

In some embodiments, the power generation system includes a rankine cycle power generation system, the rankine cycle power generation system includes the heat exchanger, the second turbine, the conveying device and a condenser, the conveying device is a refrigerant pump, and the conveying device, the heat exchanger, the second turbine and the condenser are connected in sequence and form a closed loop.

In some embodiments, the power generation system comprises an LNG expansion power generation system comprising the transfer device, the heat exchanger, and the second turbine connected in series.

In some embodiments, the power generation system comprises a rankine cycle power generation system and an LNG expansion power generation system, the heat exchanger comprises a first heat exchanger and a second heat exchanger, the second turbine comprises two, the conveying device comprises a refrigerant pump and a second conveying device, the first conveying pipe comprises a first conveying branch pipe and a second conveying branch pipe, and the second conveying pipe comprises a third conveying branch pipe and a fourth conveying branch pipe; the first heat exchanger is provided with a first heating working medium inlet, a first heating working medium outlet, a first heated working medium inlet and a first heated working medium outlet, wherein the second end of the first conveying branch pipe is communicated with the first heating working medium inlet, the second end of the third conveying branch pipe is communicated with the first heating working medium outlet, the working medium outlet of the refrigerant pump is communicated with the first heated working medium inlet, and the working medium inlet of one of the two second turbines is communicated with the first heated working medium outlet; the second heat exchanger is provided with a second heating working medium inlet, a second heating working medium outlet, a second heated working medium inlet and a second heated working medium outlet, wherein the second end of the second conveying branch pipe is communicated with the second heating working medium inlet, the second end of the fourth conveying branch pipe is communicated with the second heating working medium outlet, the working medium outlet of the second conveying device is communicated with the second heated working medium inlet, and the working medium inlet of the other of the two second turbines is communicated with the second heated working medium outlet; the Rankine cycle power generation system comprises the first heat exchanger, one of the two second turbines, the refrigerant pump and the condenser, and the refrigerant pump, the first heat exchanger, the one of the two second turbines and the condenser are sequentially connected to form a closed loop; the LNG expansion power generation system includes the second transfer device, the second heat exchanger, and the other of the two second turbines, which are connected in this order.

In some embodiments, the combined power generation system further includes a third heat exchanger, the first delivery pipe further includes a fifth delivery branch pipe, the second delivery pipe further includes a sixth delivery branch pipe, the third heat exchanger has a third heating working medium inlet, a third heating working medium outlet, a third heated working medium inlet, and a third heated working medium outlet, the second end of the fifth delivery branch pipe communicates with the third heating working medium inlet, the second end of the sixth delivery branch pipe communicates with the third heating working medium outlet, and the third heated working medium inlet communicates with the working medium outlet of the other of the two second turbines.

In some embodiments, the LNG expansion power generation system further includes a fourth heat exchanger disposed in the low-temperature heat accumulator, the fourth heat exchanger has a fourth heated working medium inlet and a fourth heated working medium outlet, the fourth heated working medium inlet is communicated with the working medium outlet of the second conveying device, and the fourth heated working medium outlet is communicated with the second heated working medium inlet.

In some embodiments, a portion of the LNG transfer line between the second transfer device and the other of the two second turbines is disposed within the cryogenic heat accumulator.

In some embodiments, the condenser has a fifth heated working medium inlet, a fifth heated working medium outlet, a fifth heated working medium inlet, and a fifth heated working medium outlet, the working medium outlet of the one of the two second turbines is communicated with the fifth heated working medium inlet, the fifth heated working medium outlet is communicated with the working medium inlet of the refrigerant pump, the fifth heated working medium inlet is communicated with the working medium outlet of the second conveying device, and the fifth heated working medium outlet is communicated with the second heated working medium inlet.

In some embodiments, the heat pump electricity storage system further comprises a first control valve, a second control valve, a third control valve, and a fourth control valve, each of the first control valve, the second control valve, the third control valve, and the fourth control valve having a first port, a second port, and a third port, the first port in switched communication with the second port and the third port; the first port of the first control valve is connected with the first port of the high-temperature heat accumulator, and the second port of the first control valve is connected with the second end of the third conveying pipe; the first port of the second control valve is connected with the second port of the high-temperature heat accumulator, and the second port of the second control valve is connected with the first end of the second conveying pipe; the first valve port of the third control valve is connected with the first port of the low-temperature heat accumulator, and the second valve port of the third control valve is connected with a working medium inlet of the compressor; the first valve port of the fourth control valve is connected with the second port of the low-temperature heat accumulator, and the second valve port of the fourth control valve is connected with a working medium inlet of the compressor; the third valve port of each of the first control valve and the second control valve is connected with the working medium inlet of the first turbine, and the third valve port of each of the third control valve and the fourth control valve is connected with the working medium outlet of the first turbine; optionally, each of the first, second, third and fourth control valves is an electromagnetic three-way valve or a pneumatic three-way valve.

Additional aspects and advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.

Drawings

Fig. 1 is a schematic diagram of a cogeneration system in which a heat pump electrical storage system is in an energy storage phase according to an embodiment of the invention.

Fig. 2 is another schematic diagram of an integrated power generation system in accordance with an embodiment of the present invention, wherein the heat pump electrical storage system is in a power generation phase.

Reference numerals:

a combined power generation system 100;

a heat pump electricity storage system 1; a high-temperature heat accumulator 11; a first port 111; a second port 112; a low-temperature heat accumulator 12; a third port 121; a fourth port 122; a compressor 13; a first turbine 14, a first duct 15; a first delivery branch 151; a second delivery leg 152; the fifth delivery branch 153; a second delivery pipe 16; a third delivery manifold 161; a fourth delivery leg 162; the sixth conveying branch 163; a motor 17; a first generator 18; a third delivery pipe 19;

a power generation system 2; a heat exchanger 21; the first heat exchanger 211; a second heat exchanger 212; a third heat exchanger 213; a second turbine 22; a second turbine 221 a; a second turbine 222 b; a condenser 23; a refrigerant pump 24; a second generator 25; a third generator 26; a fourth heat exchanger 27;

a first control valve 3; a second control valve 4; a third control valve 5; a fourth control valve 6; a first valve 7 and a second valve 8.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings. The embodiments described below with reference to the drawings are exemplary and intended to be used for explaining the present invention, and should not be construed as limiting the present invention.

A cogeneration system according to an embodiment of the invention is described below with reference to fig. 1 to 2.

As shown in fig. 1 and 2, a combined power generation system 100 according to an embodiment of the present invention includes a heat pump power storage system 1 and a power generation system 2.

The heat pump electricity storage system 1 includes a high-temperature heat accumulator 11, a low-temperature heat accumulator 12, a compressor 13, a first turbine 14, a first delivery pipe 15, and a second delivery pipe 16. The first end of the first conveying pipe 15 is connected with a working medium outlet of the compressor 13, the first end of the second conveying pipe 16 is connected with the high-temperature heat accumulator 11, the high-temperature heat accumulator 11 is connected with a working medium inlet of the first turbine 14, the working medium outlet of the first turbine 14 is connected with the low-temperature heat accumulator 12, and the low-temperature heat accumulator 12 is connected with the working medium inlet of the compressor 13. The first turbine 14 is used for performing expansion work on the gaseous circulating working medium in the heat pump electricity storage system 1. The first and second supply lines 15, 16 serve to supply the gaseous working medium compressed in the compressor 13 to the high-temperature heat accumulator 11.

The heat pump electricity storage system 1 has an energy storage stage and an electricity generation stage. In the energy storage stage, the heat pump electricity storage system 1 utilizes electric energy to make gaseous working media in the system perform a reverse brayton cycle (i.e. a cycle process of compression-heat release-expansion work-heat absorption), the electric energy input to the heat pump electricity storage system 1 from the outside is converted into heat energy and cold energy, the heat energy is stored in the high-temperature heat accumulator 11, and the cold energy is stored in the low-temperature heat accumulator 12. The compressor 13 performs more work than the first turbine 14.

The gaseous working medium in the heat pump electricity storage system 1 in the power generation stage performs a brayton cycle (i.e., a cycle process of compression, heat absorption, expansion work and heat release), and the gaseous working medium absorbs heat from the high-temperature heat accumulator 11 and releases heat to the low-temperature heat accumulator 12 (absorbs cold energy in the low-temperature heat accumulator 12). The first turbine 14 does more work than the compressor 13 does, and the heat pump electricity storage system 1 outputs power to the outside for supplying power.

The power generation system 2 includes a heat exchanger 21, a second turbine 22, and a delivery device. The heat exchanger 21 has a heating working medium inlet, a heating working medium outlet, a heated working medium inlet, and a heated working medium outlet. The second end of the first conveying pipe 15 is communicated with a heating working medium inlet of the heat exchanger 21, the second end of the second conveying pipe 16 is communicated with a heating working medium outlet of the heat exchanger 21, a working medium outlet of the conveying device is communicated with a heated working medium inlet of the heat exchanger 21, and a working medium inlet of the second turbine 22 is communicated with a heated working medium outlet of the heat exchanger 21.

The heating working medium entering the heat exchanger 21 is a medium-low temperature gaseous working medium output from a working medium outlet of the compressor 13 when the heat pump electricity storage system 1 is in the electricity generation stage, and the heated working medium is a circulating working medium in the electricity generation system 2.

The first conveying pipe 15 can enable the heating working medium with higher temperature to enter the heat exchanger 21 from the heating working medium inlet of the heat exchanger 21, and the heated working medium with lower temperature enters the heat exchanger 21 from the heated working medium inlet of the heat exchanger 21 under the driving of the conveying device. The heating working medium exchanges heat with the heated working medium in the heat exchanger 21, and the heat is transmitted to the heated working medium by the heating working medium, so that the temperature of the heating working medium is reduced, and the temperature of the heated working medium is increased. The heat-exchanged heating working medium flows into the second conveying pipe 16 from the heating working medium outlet of the heat exchanger 21 so as to be conveyed to downstream equipment.

Therefore, the medium-low temperature gaseous working medium output from the working medium outlet of the compressor 13 transmits the medium-low temperature waste heat to the heated working medium in the heat exchanger 21, namely, the heat is transmitted to the heated working medium from the medium-low temperature gaseous working medium, so that the power generation system 2 recovers and recycles the medium-low temperature waste heat of the heat pump power storage system 1, and the power generation system 2 generates power by utilizing the waste heat of the heat pump power storage system 1.

According to the utility model discloses combined power generation system includes the heat pump accumulate system based on positive contrary brayton cycle to through set up in power generation system with heat pump accumulate system complex heat exchanger, thereby make the circulation working medium among the power generation system can absorb the heat of well low temperature gaseous state working medium among the heat pump accumulate system, so that power generation system can retrieve the well low temperature waste heat quantity (generate electricity) that heat pump accumulate system leads to owing to irreversible loss.

The combined power generation system for heat pump power storage and medium and low temperature waste heat power generation realizes clean and low carbon combined energy storage power generation and efficient waste heat utilization, improves the power generation efficiency and the heat energy utilization efficiency, also improves the cycle efficiency of the heat pump power storage system, and reduces the irreversible loss of power generation cycle and energy storage cycle. The total amount of work and power generation of the combined power generation system is remarkably increased, and more electric power can be provided for the outside.

Therefore, the embodiment of the utility model provides a combined power generation system has advantages such as generating efficiency is high, energy conversion efficiency is high, heat utilization rate is high, energy-concerving and environment-protective.

In some embodiments, as shown in fig. 1, the heat pump electric storage system 1 further includes an electric motor 17 and a first generator 18. The motor 17 is connected to the compressor 13 to provide a driving force to the compressor 13. The first generator 18 is coupled to the first turbine 14 in a power coupling manner, i.e., the first turbine 14 is used to drive the first generator 18 to generate electric power. Illustratively, the first turbine 14 is coupled to a speed reducer and a first generator 18 via a shaft. Gaseous working media in the heat pump electricity storage system 1 enter the first turbine 14 from a working medium inlet of the first turbine 14 and do expansion work, and the first turbine 14 is matched with the first generator 18 to convert kinetic energy into electric energy and output the electric energy to the outside. The gaseous working fluid then flows out of the working fluid outlet of the first turbine 14.

In some embodiments, the high temperature regenerator 11 includes a first port 111 and a second port 112 and the low temperature regenerator 12 includes a third port 121 and a fourth port 122. As an example, in the up-down direction indicated by the arrow shown in fig. 1, the first port 111 is a top port of the high-temperature regenerator 11, and the second port 112 is a bottom port of the high-temperature regenerator 11. The third port 121 is the top port of the low temperature regenerator 12 and the fourth port 122 is the bottom port of the low temperature regenerator 12. Each of the first and second ports 111, 112 is connected to a working fluid inlet of the first turbine 14. Each of the third and fourth ports 121, 122 is connected to a working fluid outlet of the first turbine 14. Each of the third and fourth ports 121 and 122 is also connected to a working fluid inlet of the compressor 13. A first end of the second delivery pipe 16 is connected to the second port 112, that is, the first end of the second delivery pipe 16 communicates with the bottom port of the high-temperature regenerator 11.

In some embodiments, the heat pump electric storage system 1 further comprises a third delivery pipe 19. A first end of the third duct 19 is connected to the working medium outlet of the compressor 13, and a second end of the third duct 19 is connected to the first port 111. The third line 19 is used to feed the gaseous working medium compressed in the compressor 13 into the high-temperature heat accumulator 11.

As an example, when the heat pump electricity storage system 1 is in the energy storage stage, the high-temperature gaseous working medium flowing out of the compressor 13 enters the high-temperature heat accumulator 11 through the third delivery pipe 19. When the heat pump electricity storage system 1 is in the electricity generation stage, the medium-low temperature gaseous working medium flowing out of the compressor 13 sequentially passes through the first delivery pipe 15, the heat exchanger 21 and the second delivery pipe 16 and enters the high-temperature heat accumulator 11. Because the temperature of the medium-low temperature gaseous working medium is reduced after heat exchange in the heat exchanger 21, when the heat pump electricity storage system 1 is in the electricity generation stage, the state of the gaseous working medium entering the high-temperature heat accumulator 11 is normal temperature, namely the state of the gaseous working medium returns to the state point corresponding to the energy storage cycle.

In some embodiments, as shown in fig. 1, the heat pump electric storage system 1 further includes a first control valve 3, a second control valve 4, a third control valve 5, and a fourth control valve 6. Each of the first control valve 3, the second control valve 4, the third control valve 5, and the fourth control valve 6 has a first port, a second port, and a third port. The first port is in switching communication with the second port and the third port.

The switching communication of the first port with the second port and the third port means that: the first control valve 3 (the second control valve 4, the third control valve 5) may be switched from a state in which the first port and the second port are communicated with each other to a state in which the first port and the third port are communicated with each other, or may be switched from a state in which the first port and the third port are communicated with each other to a state in which the first port and the second port are communicated with each other.

Specifically, as shown in fig. 1, the first port of the first control valve 3 is connected to the first port 111 (top port) of the high-temperature regenerator 11, and the second port of the first control valve 3 is connected to the second end of the third transfer pipe 19. The first port of the second control valve 4 is connected to the second port 112 (bottom port) of the high-temperature regenerator 11, and the second port of the second control valve 4 is connected to the first end of the second delivery pipe 16.

A first valve port of the third control valve 5 is connected with a third port 121 (top port) of the low-temperature heat accumulator 12, and a second valve port of the third control valve 5 is connected with a working medium inlet of the compressor 13. The first port of the fourth control valve 6 is connected to the fourth port 122 (bottom port) of the low-temperature heat accumulator 12, and the second port of the fourth control valve 6 is connected to the working medium inlet of the compressor 13.

The third valve port of each of the first control valve 3 and the second control valve 4 is connected to the working fluid inlet of the first turbine 14. The third valve port of each of the third control valve 5 and the fourth control valve 6 is connected to the working medium outlet of the first turbine 14.

The first control valve 3, the second control valve 4, the third control valve 5 and the fourth control valve 6 are used for controlling the gaseous working medium to pass through the high-temperature heat accumulator 11 and the low-temperature heat accumulator 12 from different directions in the energy storage and power generation stages.

Specifically, as shown in fig. 1, when the heat pump electricity storage system 1 is in the energy storage stage, the gaseous working medium enters from the top port of the high-temperature heat accumulator 11, and flows out from the bottom port, that is, the gaseous working medium flows through the high-temperature heat accumulator 11 from top to bottom in the energy storage stage. The gaseous working medium enters from the bottom port of the low-temperature heat accumulator 12, and flows out from the top port, namely, the gaseous working medium flows in the low-temperature heat accumulator 12 from top to bottom in the energy storage stage.

When the heat pump electricity storage system 1 is in the power generation stage, the gaseous working medium enters from the bottom port of the high-temperature heat accumulator 11, and flows out from the top port, namely, the gaseous working medium flows in the high-temperature heat accumulator 11 from bottom to top in the power generation stage. The gaseous working medium enters from the top port of the low-temperature heat accumulator 12, and flows out from the bottom port, namely, the gaseous working medium flows in the low-temperature heat accumulator 12 from top to bottom in the power generation stage.

Through the arrangement of the first control valve 3, the second control valve 4, the third control valve 5 and the fourth control valve 6, the heat transfer temperature difference of the gaseous working medium can be reduced, and the reversibility of the heat pump electricity storage system 1 is improved.

Alternatively, each of the first control valve 3, the second control valve 4, the third control valve 5, and the fourth control valve 6 is an electromagnetic three-way valve or a pneumatic three-way valve.

In some embodiments, as shown in fig. 1, the heat pump electric storage system 1 further comprises a first valve 7 and a second valve 8. The first valve 7 is arranged on the third duct 19 and the second valve 8 is arranged on the first duct 15. When the heat pump electricity storage system 1 is in the energy storage stage, the first valve 7 is opened, and the second valve 8 is closed; when the heat pump electricity storage system 1 is in the electricity generation stage, the second valve 8 is opened, and the first valve 7 is closed. The first valve 7 and the second valve 8 are used for controlling the flow path of the gaseous working medium in the power generation stage and the energy storage stage.

In some embodiments, the power generation system 2 is turned off when the heat pump power storage system 1 is in the energy storage phase. When the heat pump electricity storage system 1 is in the electricity generation stage, the electricity generation system 2 is turned on and generates electricity by using the waste heat of the heat pump electricity storage system 1.

In some embodiments, the power generation system 2 comprises a rankine cycle power generation system including the first heat exchanger 211, the second turbine 221a, the transport device, and the condenser 23. The first heat exchanger 211 has a first heating working medium inlet, a first heating working medium outlet, a first heated working medium inlet, and a first heated working medium outlet.

Specifically, as shown in fig. 1, the delivery device is a refrigerant pump 24 as an example. The refrigerant pump 24, the first heat exchanger 211, the second turbine 221a, and the condenser 23 are connected in sequence to form a closed loop. For example, the refrigerant pump 24, the first heat exchanger 211, the second turbine 221a, and the condenser 23 may be connected in sequence by pipes. Specifically, a working medium outlet of the refrigerant pump 24 is connected with a first heated medium inlet of the first heat exchanger 211 through a pipeline, a first heated medium outlet of the first heat exchanger 211 is communicated with a medium inlet of the second turbine 221a, a medium outlet of the second turbine 221a is communicated with a heating medium inlet of the condenser 23, and a medium outlet of the condenser 23 is communicated with a heating working medium inlet of the refrigerant pump 24, so that a closed loop is formed.

And the Rankine cycle working medium performs Rankine cycle in the Rankine cycle power generation system. Specifically, the liquid rankine cycle working medium enters the first heat exchanger 211 as a heated working medium from a first heated working medium inlet of the first heat exchanger 211, and the liquid rankine cycle working medium exchanges heat with a heating working medium (medium-low temperature gaseous working medium) of the heat pump electricity storage system 1 in the first heat exchanger 211. The liquid Rankine cycle working medium is heated to be evaporated by the heating working medium so as to become a high-temperature and high-pressure gaseous Rankine cycle working medium. The high-temperature high-pressure gaseous Rankine cycle working medium flows out of the first heated working medium outlet of the first heat exchanger 211, is expanded by the second turbine 221a to act to be changed into a low-temperature low-pressure gaseous Rankine cycle working medium, the low-temperature low-pressure gaseous Rankine cycle working medium flows into the condenser 23 and is condensed into a liquid Rankine cycle working medium in the condenser 23, and the liquid Rankine cycle working medium is then boosted by the refrigerant pump 24, so that one Rankine cycle is completed, and external acting and power generation are realized.

Further, in the above embodiment, the rankine cycle power generation system further includes the second generator 25, the second generator 25 is in power coupling connection with the second turbine 221a, and the second turbine 221a drives the second generator 25 to generate electric energy.

In some embodiments, the power generation system 2 comprises an LNG expansion power generation system including a second transfer device (not shown), a second heat exchanger 212, and a second turbine 222b connected in series. The second transfer device, the second heat exchanger 212, and the second turbine 222b may be connected in series via an LNG transfer line 262. The second heat exchanger 212 has a second heating working medium inlet, a second heating working medium outlet, a second heated working medium inlet, and a second heated working medium outlet. Wherein the working medium inlet of the second turbine 222b is communicated with the second heated working medium outlet of the second heat exchanger 212. The working medium outlet of the second conveying device is communicated with the second heated working medium inlet of the second heat exchanger 212, and the working medium inlet of the second turbine 222b is communicated with the second heated working medium outlet of the second heat exchanger 212.

Further, in the above embodiment, the LNG expansion power generation system further includes a third generator 26, the third generator 26 is coupled to the second turbine 222b, and the second turbine 222b drives the third generator 26 to generate electric power.

The working medium introduced into the LNG expansion power generation system is LNG (liquefied natural gas, the temperature is about-161.5 ℃), and the natural gas input to the user system has a certain temperature requirement, so that the LNG can be heated after passing through the second heat exchanger 212, the heat load of the LNG supply station is reduced, the medium-low temperature waste heat of the heat pump power storage system 1 can be used for power generation, and the total power generation efficiency of the combined power generation system 100 is improved.

In some embodiments, as shown in fig. 1, the power generation system 2 includes the rankine cycle power generation system described above and the LNG expansion power generation system described above. The heat exchanger 21 comprises a first heat exchanger 211 and a second heat exchanger 212, and the second turbine 22 comprises two: a second turbine 221a and a second turbine 222 b. The delivery device includes a coolant pump 24 and a second delivery device.

The first delivery pipe 15 includes a first delivery branch 151 and a second delivery branch 152. The second delivery pipe 16 includes a third delivery branch 161 and a fourth delivery branch 162. First ends of the first conveying branch pipe 151 and the second conveying branch pipe 152 are communicated with a working medium outlet of the compressor 13, and first ends of the third conveying branch pipe 161 and the fourth conveying branch pipe 162 are connected with the second port 112 of the high-temperature heat accumulator 11.

The second end of the first delivery branch pipe 151 is communicated with the first heating working medium inlet of the first heat exchanger 211, and the second end of the third delivery branch pipe 161 is communicated with the first heating working medium outlet of the first heat exchanger 211. That is, the first delivery branch pipes 151 can input the heating working medium into the first heat exchanger 211, and the heat-exchanged heating working medium flows into the third delivery branch pipes 161.

The second end of the second delivery branch pipe 152 is communicated with the second heating working medium inlet of the second heat exchanger 212, and the second end 162 of the fourth delivery branch pipe is communicated with the second heating working medium outlet of the second heat exchanger 212. That is, the second delivery branch pipe 152 can input the heating working medium into the second heat exchanger 212, and the heat-exchanged heating working medium flows into the fourth delivery branch pipe 162.

As an example, as shown in fig. 1, the first heat exchanger 211 and the second heat exchanger 212 are connected in parallel, that is, a part of the medium-low temperature gaseous working medium flowing out from the working medium outlet of the compressor 13 can flow into the first heat exchanger 211 through the first delivery branch pipe 151, and another part of the medium-low temperature gaseous working medium flowing out from the working medium outlet of the compressor 13 can flow into the second heat exchanger 212 through the second delivery branch pipe 152.

In some embodiments, the cogeneration system 100 further comprises a third heat exchanger 213. Specifically, the LNG expansion power generation system further includes a third heat exchanger 213. The first delivery duct 15 comprises a fifth delivery branch 153 and the second delivery duct 16 comprises a sixth delivery branch 163. The third heat exchanger 213 has a third heating working medium inlet, a third heating working medium outlet, a third heated working medium inlet, and a third heated working medium outlet. The second end of the fifth delivery branch pipe 153 is communicated with the third heating working medium inlet of the third heat exchanger 213, the second end of the sixth delivery branch pipe 163 is communicated with the third heating working medium outlet of the third heat exchanger 213, and the third heated working medium inlet of the third heat exchanger 213 is communicated with the medium outlet of the second turbine 222 b. In other words, the third heat exchanger 213 is located downstream of the second turbine 222 b.

The third heat exchanger 213 is used to further heat the natural gas in the LNG transfer line 262 to a suitable temperature before being delivered to the customer's pipeline, further reducing the heat load on the LNG supply station. The third heat exchanger 213 can further recycle the waste heat in the heat pump electricity storage system 1, thereby improving the waste heat recycling efficiency.

As an example, as shown in fig. 1, the first heat exchanger 211, the second heat exchanger 212 and the third heat exchanger 213 are connected in parallel, i.e. the gaseous working medium flowing out of the working medium outlet of the compressor 13 comprises a first portion, which can flow into the first heat exchanger 211 through the first delivery branch 151, a second portion, which can flow into the second heat exchanger 212 through the second delivery branch 152, and a third portion, which can flow into the third heat exchanger 213 through the fifth delivery branch 153.

In some embodiments, as shown in fig. 1, the LNG expansion power generation system further includes a fourth heat exchanger 27, the fourth heat exchanger 27 being disposed within the cryogenic heat accumulator 12. The fourth heat exchanger 27 is provided with a fourth heated working medium inlet and a fourth heated working medium outlet, the fourth heated working medium inlet of the fourth heat exchanger 27 is communicated with the working medium outlet of the second conveying device of the LNG expansion power generation system, and the fourth heated working medium outlet of the fourth heat exchanger 27 is communicated with the second heated working medium inlet of the second heat exchanger 212.

For the fourth heat exchanger 27, the heated working medium is LNG, and the heating working medium is the heat storage material in the low-temperature heat accumulator 12. The fourth heat exchanger 27 is used for transferring the cold energy of the LNG to the low-temperature heat accumulator 12, or the heat accumulation material in the low-temperature heat accumulator 12 can heat the LNG serving as the heated working medium. The LNG with a lower temperature enters the fourth heat exchanger 27 from the fourth heated working medium inlet, and the heat storage material in the low-temperature heat accumulator 12 transfers heat to the LNG, so that the LNG plays a role in cooling the low-temperature heat accumulator 12. Meanwhile, the temperature of the LNG itself is increased to some extent due to heating. The LNG releases part of cold energy through the fourth heat exchanger 27, so that the cold energy lost in the low-temperature heat accumulator 12 is supplemented, and the efficiency of the heat pump electricity storage system 1 is further improved.

Alternatively, in other embodiments, a portion of the LNG transfer line 262 between the second transfer device and the second turbine 222b of the LNG expansion power generation system is disposed within the cryogenic heat accumulator 12. In other words, a part of the LNG transfer pipe 262 may serve as a cooling pipe for cooling the low-temperature heat accumulator 12, thereby achieving that the LNG transfers cold energy to the low-temperature heat accumulator 12 during the transfer in the LNG transfer pipe 262, while the temperature of the LNG itself is increased.

Specifically, as shown in fig. 1, the fourth heat exchanger 27 (the portion of the LNG transfer line 262) is located upstream of the second heat exchanger 212. I.e., LNG flows through fourth heat exchanger 27 (the portion of LNG transfer line 262) before flowing through second heat exchanger 212.

In some embodiments, as shown in FIG. 1, condenser 23 has an fifth heated working fluid inlet, a fifth heated working fluid outlet, a fifth heated working fluid inlet, and a fifth heated working fluid outlet. The working medium outlet of the second turbine 221a is communicated with the fifth heating working medium inlet, the fifth heating working medium outlet is communicated with the working medium inlet of the refrigerant pump 24, the fifth heating working medium inlet is communicated with the working medium outlet of the second conveying device, and the fifth heating working medium outlet is communicated with the second heating working medium inlet of the second heat exchanger 212.

Alternatively, the condenser 23 is located upstream of the second heat exchanger 212, i.e., the LNG flows through the condenser 23 and then through the second heat exchanger 212. The condenser 23 is located downstream of the second turbine 221a and upstream of the refrigerant pump 24, that is, the rankine cycle working medium flows through the second turbine 221a, then flows through the condenser 23, and then flows through the refrigerant pump 24.

The LNG further releases part of cold energy through the condenser 23, namely, gaseous Rankine cycle working medium is condensed by using the cold energy of the LNG. In addition, the above arrangement reduces the condensing temperature of the second turbine 221a, and improves the power generation efficiency of the rankine cycle power generation system.

Preferably, the Rankine cycle working fluid is a mixture which is not solidified in the LNG operation range and has a wide freezing point range, such as a hydrocarbon compound, a Freon working fluid or a mixture.

Optionally, the gaseous working medium of the heat pump electricity storage system 1 is air, argon, nitrogen or other working medium.

One embodiment and the energy storage and power generation process thereof will be described in detail below with reference to the combined power generation system 100 shown in fig. 1 and 2.

As shown in fig. 1 and 2, the combined power generation system 100 in the present embodiment includes: the system comprises a heat pump electricity storage system 1, a Rankine cycle power generation system and an LNG expansion power generation system.

The heat pump electricity storage system 1 includes a high temperature heat accumulator 11, a low temperature heat accumulator 12, a compressor 13, a first turbine 14, a first delivery branch 151, a second delivery branch 152, a fifth delivery branch 153, a third delivery branch 161, a fourth delivery branch 162, a sixth delivery branch 163, an electric motor 17, a first generator 18, and a third delivery pipe 19. The rankine cycle power generation system includes a first heat exchanger 211, a second turbine 221a, a condenser 23, a refrigerant pump 24, a second generator 25, and a rankine cycle 261. The LNG expansion power generation system includes a second transfer device, a second heat exchanger 212, a third heat exchanger 213, a second turbine 222b, an LNG transfer pipe 262, a third power generator 26, and a fourth heat exchanger 27.

The electric motor 17 is connected to the compressor 13 to provide a driving force for the compressor 13, and the compressor 13 has a working medium inlet and a working medium outlet. The first generator 18 is coupled to the first turbine 14. The first turbine 14 has a working fluid inlet and a working fluid outlet.

The first end of the first delivery branch pipe 151 is connected with the working medium outlet of the compressor 13, and the second end of the first delivery branch pipe 151 is connected with the first heating working medium inlet of the first heat exchanger 211. A first end of the third delivery branch pipe 161 is connected with the second port 112 of the high-temperature heat accumulator 11, or a first end of the third delivery branch pipe 161 is connected with the second port 112 of the high-temperature heat accumulator 11 by being connected with the second valve port of the second control valve 4, and a second end of the third delivery branch pipe 161 is connected with the first heating working medium outlet of the first heat exchanger 211. A first end of the third delivery pipe 19 is connected with a working medium outlet of the compressor 13, a second end of the third delivery pipe 19 is connected with a first port 111 of the high-temperature heat accumulator 11, or a second end of the third delivery pipe 19 is connected with a second port of the first control valve 3 to be connected with the first port 111 of the high-temperature heat accumulator 11.

The first port 111 of the high temperature regenerator 11 is connected to the working fluid inlet of the first turbine 14 via the first control valve 3, and the second port 112 of the high temperature regenerator 11 is connected to the working fluid inlet of the first turbine 14 via the second control valve 4. The third port 121 of the low-temperature heat accumulator 12 is connected to the working medium outlet of the first turbine 14 and the working medium inlet of the compressor 13 via the third control valve 5. The fourth port 122 of the low temperature heat accumulator 12 is connected to the working fluid outlet of the first turbine 14 and the working fluid inlet of the compressor 13 via the fourth control valve 6.

The rankine cycle 261 is configured by connecting the first heat exchanger 211, the second turbine 221a, the condenser 23, and the refrigerant pump 24 in series to form a closed loop. The second generator 25 is coupled to the second turbine 221 a.

The first heated working medium inlet of the first heat exchanger 211 is communicated with the working medium outlet of the refrigerant pump 24, the first heated working medium outlet of the first heat exchanger 211 is communicated with the working medium inlet of the second turbine 221a, the working medium outlet of the second turbine 221a is communicated with the fifth heated working medium inlet of the condenser 23, and the fifth heated working medium outlet of the condenser 23 is communicated with the working medium inlet of the refrigerant pump 24.

The working medium outlet of the second conveying device is communicated with the fourth heated working medium inlet of the fourth heat exchanger 27, the fourth heated working medium outlet of the fourth heat exchanger 27 is communicated with the fifth heated working medium inlet of the condenser 23, the fifth heated working medium outlet of the condenser 23 is communicated with the second heated working medium inlet of the second heat exchanger 212, the second heated working medium outlet of the second heat exchanger 212 is communicated with the working medium inlet of the second turbine 222b, and the working medium outlet of the second turbine 222b is communicated with the third heated working medium inlet of the third heat exchanger 213.

The first end of the second conveying branch pipe 152 is connected with the working medium outlet of the compressor 13, the second end of the second conveying branch pipe 152 is communicated with the second heating working medium inlet of the second heat exchanger 212, the second end of the fourth conveying branch pipe 162 is communicated with the second heating working medium outlet of the second heat exchanger 212, and the first end of the fourth conveying branch pipe 162 is communicated with the second port 112 of the high-temperature heat accumulator 11.

The first end of the fifth delivery branch pipe 153 is connected with the working medium outlet of the compressor 13, the second end of the fifth delivery branch pipe 153 is communicated with the third heating working medium inlet of the third heat exchanger 213, the second end of the sixth delivery branch pipe 163 is communicated with the third heating working medium outlet of the third heat exchanger 213, and the first end of the sixth delivery branch pipe 163 is communicated with the second port 112 of the high-temperature heat accumulator 11.

In the energy storage stage, the heat pump electricity storage system 1 performs an energy storage cycle, the first valve 7 is opened, and the second valve 8 is closed. And closing the Rankine cycle power generation system and the LNG expansion power generation system.

The gaseous working medium in the heat pump electricity storage system 1 performs a cycle process of compression, heat release, expansion work and heat absorption, the work of the compressor 13 is greater than that of the first turbine 14, and the external power is input into the system and then is respectively stored in the high-temperature heat accumulator 11 and the low-temperature heat accumulator 12 in the forms of heat energy and cold energy. The medium temperature gaseous working medium (about 200 ℃ to 300 ℃) becomes a high temperature gaseous working medium (about 1000 ℃) after being compressed by the compressor 13, the high temperature gaseous working medium is introduced from the first port 111 of the high temperature heat accumulator 11 and heats the refractory material in the high temperature heat accumulator 11, the refractory material is gradually heated from top to bottom, the temperature of the high temperature gaseous working medium is gradually reduced, and the high temperature gaseous working medium becomes a normal temperature gaseous working medium (about-20 ℃) after flowing out from the second port 112 of the high temperature heat accumulator 11. The normal temperature gaseous working medium is expanded by the first turbine 14 and then cooled to become a low temperature gaseous working medium (about-60 ℃). The low-temperature gaseous working medium is introduced from the fourth port 122 of the low-temperature heat accumulator 12 and cools the refractory material in the low-temperature heat accumulator 12, the refractory material is gradually cooled from bottom to top, the temperature of the low-temperature gaseous working medium is gradually increased from bottom to top, after the low-temperature gaseous working medium flows out from the third port 121 of the low-temperature heat accumulator 12, the low-temperature gaseous working medium becomes a medium-temperature gaseous working medium, and the medium-temperature gaseous working medium flows into the compressor 13 to complete an energy storage cycle.

After the energy storage stage is cycled for multiple times, the hot front of the refractory material in the high-temperature heat accumulator 11 moves from top to bottom, and the cold front of the refractory material in the low-temperature heat accumulator 12 moves from bottom to top. After the energy storage stage is finished, the heat front in the high-temperature heat accumulator 11 moves to the bottom, and the refractory material completely stores high-temperature heat; the cold front in the low temperature heat accumulator 12 moves to the top and the refractory material stores the low temperature heat completely.

In the power generation stage, the heat pump power storage system 1 performs a power generation cycle, closes the first valve 7, and opens the second valve 8. And opening the Rankine cycle power generation system and the LNG expansion power generation system.

The gaseous working medium in the heat pump electricity storage system 1 performs a cycle process of compression, heat absorption, expansion work and heat release, and the gaseous working medium absorbs heat from the high-temperature heat accumulator 11 and releases heat to the low-temperature heat accumulator 12. In the process, the work of the first turbine 14 is larger than that of the compressor 13, and the first turbine 14 drives the first generator 18 to generate electricity. The heat pump electricity storage system 1 supplies electricity with the net output of the outside. The low-temperature gaseous working medium is compressed by the compressor 13 to become a medium-low temperature gaseous working medium (about 150 ℃). The medium-low temperature gaseous working medium provides medium-low temperature waste heat for the Rankine cycle power generation system through the first heat exchanger 211, and the medium-low temperature gaseous working medium provides medium-low temperature waste heat for the LNG expansion power generation system through the second heat exchanger 212 and the third heat exchanger 213. When the gaseous working medium is introduced from the second port 112 of the high-temperature heat accumulator 11, the gaseous working medium is a normal-temperature gaseous working medium, the normal-temperature gaseous working medium passes through the high-temperature heat accumulator 11 from bottom to top, the heat stored by the high-temperature refractory material is absorbed, and the temperature of the gaseous working medium is gradually increased. And the working fluid flows out of the first port 111 of the high-temperature heat accumulator 11 and becomes a high-temperature gaseous working fluid. The high-temperature gaseous working medium expands through the first turbine 14 to do work, and drives the first generator 18 to generate electricity. The high-temperature gaseous working medium is expanded and then cooled to become a medium-temperature gaseous working medium, and the medium-temperature gaseous working medium enters the low-temperature heat accumulator 12 from the third port 121 of the low-temperature heat accumulator 12. The medium temperature gaseous working medium is cooled, the temperature of the low temperature refractory material in the low temperature heat accumulator 12 is gradually increased, and the temperature of the gaseous working medium is gradually decreased. The gaseous working medium flows out from the fourth port 122 of the low-temperature heat accumulator 12 and becomes a low-temperature gaseous working medium. The low-temperature gaseous working medium flows into the compressor 13 to complete a power generation cycle.

After multiple cycles in the power generation stage, the cold front of the refractory material in the high-temperature heat accumulator 11 moves from bottom to top, and the hot front of the refractory material in the low-temperature heat accumulator 12 moves from top to bottom. After the power generation stage is finished, the cold front in the high-temperature heat accumulator 11 moves to the top, and the refractory material completely releases high-temperature heat; the heat front in the low temperature heat accumulator 12 moves to the bottom and the refractory material releases the low temperature heat completely.

In the power generation stage, the intermediate-low temperature waste heat of the intermediate-low temperature gaseous working medium in the heat pump power storage system 1 heats the rankine cycle working medium through the first heat exchanger 211 until the rankine cycle working medium is evaporated, and the high-temperature and high-pressure rankine cycle working medium steam is expanded by the second turbine 221a to apply work to drive the second power generator 25 to generate power. The low-pressure Rankine cycle working medium steam after expansion working is condensed in the condenser 23 and then flows through the refrigerant pump 24 to boost the pressure of liquid, and the outward working and power generation of the steam power cycle are completed.

The LNG releases part of the cold energy through the fourth heat exchanger 27 for supplementing the cold energy in the cryogenic heat accumulator 12. The LNG is then passed through a condenser 23 to release cold energy. The LNG absorbs heat and is vaporized after passing through the condenser 23, and then the low-medium temperature waste heat of the heat pump electricity storage system 1 is recovered through the second heat exchanger 212, so that the LNG is further vaporized and heated. The heated and gasified natural gas is used as work by the second turbine 222b to drive the third generator 26 to generate electricity. The natural gas which has finished doing work is heated by the third heat exchanger 2135 and then is conveyed to the natural gas pipeline network of the user.

The embodiment of the utility model provides an in combined power generation system 100 heat pump electricity storage system 1 and rankine cycle power generation system are closed circulation, and no emission is pollution-free.

The combined power generation system 100 in the embodiment of the present invention is used for stabilizing instability and intermittency of wind power generation or photovoltaic power generation, etc., and realizing stable output of renewable energy power; the method is used for peak clipping and valley filling of a conventional power system, and the efficiency and the safety of a regional energy system are improved; the method is used for utilizing the valley electricity of the user side and improving the efficiency and the economy of an energy system.

In the description of the present invention, it is to be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", and the like, indicate the orientation or positional relationship indicated based on the drawings, and are only for convenience of description and simplicity of description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore, should not be construed as limiting the present invention.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "a plurality" means at least two, e.g., two, three, etc., unless specifically limited otherwise.

In the present invention, unless otherwise expressly stated or limited, the terms "mounted," "connected," and "fixed" are to be construed broadly and may, for example, be fixedly connected, detachably connected, or integrally formed; may be mechanically coupled, may be electrically coupled or may be in communication with each other; they may be directly connected or indirectly connected through intervening media, or they may be connected internally or in any other suitable relationship, unless expressly stated otherwise. The specific meaning of the above terms in the present invention can be understood according to specific situations by those skilled in the art.

In the present application, unless expressly stated or limited otherwise, the first feature may be directly on or directly under the second feature or indirectly via intermediate members. Also, a first feature "on," "over," and "above" a second feature may be directly or diagonally above the second feature, or may simply indicate that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature may be directly under or obliquely under the first feature, or may simply mean that the first feature is at a lesser elevation than the second feature.

In the present disclosure, the terms "one embodiment," "some embodiments," "an example," "a specific example," or "some examples" or the like mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present disclosure. In this specification, the schematic representations of the terms used above are not necessarily intended to refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, various embodiments or examples and features of different embodiments or examples described in this specification can be combined and combined by one skilled in the art without contradiction.

Although embodiments of the present invention have been shown and described, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention, and that variations, modifications, substitutions and alterations can be made to the above embodiments by those of ordinary skill in the art without departing from the scope of the present invention.

Claims (10)

1. A combined power generation system, comprising:

the heat pump electricity storage system comprises a high-temperature heat accumulator, a low-temperature heat accumulator, a compressor, a first turbine, a first conveying pipe and a second conveying pipe, wherein the first end of the first conveying pipe is connected with a working medium outlet of the compressor, the first end of the second conveying pipe is connected with the high-temperature heat accumulator, the high-temperature heat accumulator is connected with a working medium inlet of the first turbine, a working medium outlet of the first turbine is connected with the low-temperature heat accumulator, and the low-temperature heat accumulator is connected with a working medium inlet of the compressor; and

the power generation system comprises a heat exchanger, a second turbine and a conveying device, wherein the heat exchanger is provided with a heating working medium inlet, a heating working medium outlet, a heated working medium inlet and a heated working medium outlet, the second end of the first conveying pipe is communicated with the heating working medium inlet, the second end of the second conveying pipe is communicated with the heating working medium outlet, the working medium outlet of the conveying device is communicated with the heated working medium inlet, and the working medium inlet of the second turbine is communicated with the heated working medium outlet.

2. The combined power generation system of claim 1, wherein the heat pump electrical storage system further comprises a third transfer line, the high temperature heat accumulator comprises a first port and a second port, the low temperature heat accumulator comprises a third port and a fourth port, a first end of the third transfer line is connected to the working fluid outlet of the compressor, a second end of the third transfer line is connected to the first port, a second end of the second transfer line is connected to the second port, each of the first port and the second port is connected to the working fluid inlet of the first turbine, each of the third port and the fourth port is connected to the working fluid outlet of the first turbine, and each of the third port and the fourth port is connected to the working fluid inlet of the compressor.

3. The combined power generation system of claim 1, wherein the power generation system comprises a rankine cycle power generation system, the rankine cycle power generation system comprises the heat exchanger, the second turbine, the conveying device and a condenser, the conveying device is a refrigerant pump, and the conveying device, the heat exchanger, the second turbine and the condenser are connected in sequence and form a closed loop.

4. The combined power generation system of claim 1, wherein the power generation system comprises an LNG expansion power generation system including the transfer device, the heat exchanger, and the second turbine in series.

5. The combined power generation system of claim 1, wherein the power generation system comprises a rankine cycle power generation system and an LNG expansion power generation system, the heat exchangers comprise a first heat exchanger and a second heat exchanger, the second turbine comprises two, the delivery device comprises a refrigerant pump and a second delivery device, the first delivery pipe comprises a first delivery branch and a second delivery branch, and the second delivery pipe comprises a third delivery branch and a fourth delivery branch;

the first heat exchanger is provided with a first heating working medium inlet, a first heating working medium outlet, a first heated working medium inlet and a first heated working medium outlet, wherein the second end of the first conveying branch pipe is communicated with the first heating working medium inlet, the second end of the third conveying branch pipe is communicated with the first heating working medium outlet, the working medium outlet of the refrigerant pump is communicated with the first heated working medium inlet, and the working medium inlet of one of the two second turbines is communicated with the first heated working medium outlet;

the second heat exchanger is provided with a second heating working medium inlet, a second heating working medium outlet, a second heated working medium inlet and a second heated working medium outlet, wherein the second end of the second conveying branch pipe is communicated with the second heating working medium inlet, the second end of the fourth conveying branch pipe is communicated with the second heating working medium outlet, the working medium outlet of the second conveying device is communicated with the second heated working medium inlet, and the working medium inlet of the other of the two second turbines is communicated with the second heated working medium outlet;

the Rankine cycle power generation system comprises the first heat exchanger, one of the two second turbines, the refrigerant pump and the condenser, and the refrigerant pump, the first heat exchanger, the one of the two second turbines and the condenser are sequentially connected to form a closed loop;

the LNG expansion power generation system includes the second transfer device, the second heat exchanger, and the other of the two second turbines, which are connected in this order.

6. The combined power generation system of claim 5, further comprising a third heat exchanger, the first delivery pipe further comprising a fifth delivery branch pipe, the second delivery pipe further comprising a sixth delivery branch pipe, the third heat exchanger having a third heating working medium inlet, a third heating working medium outlet, a third heated working medium inlet, and a third heated working medium outlet, the fifth delivery branch pipe having a second end in communication with the third heating working medium inlet, the sixth delivery branch pipe having a second end in communication with the third heating working medium outlet, the third heated working medium inlet in communication with the working medium outlet of the other of the two second turbines.

7. The combined power generation system of claim 5,

the LNG expansion power generation system further comprises a fourth heat exchanger, the fourth heat exchanger is arranged in the low-temperature heat accumulator and is provided with a fourth heated working medium inlet and a fourth heated working medium outlet, the fourth heated working medium inlet is communicated with the working medium outlet of the second conveying device, and the fourth heated working medium outlet is communicated with the second heated working medium inlet.

8. The combined power generation system according to claim 5, wherein a portion of the LNG transfer line between the second transfer arrangement and the other of the two second turbines is disposed within the cryogenic heat accumulator.

9. The combined power generation system of claim 5, wherein the condenser has a fifth heated working medium inlet, a fifth heated working medium outlet, a fifth heated working medium inlet, and a fifth heated working medium outlet, the working medium outlet of the one of the two second turbines is in communication with the fifth heated working medium inlet, the fifth heated working medium outlet is in communication with the working medium inlet of the refrigerant pump, the fifth heated working medium inlet is in communication with the working medium outlet of the second conveying device, and the fifth heated working medium outlet is in communication with the second heated working medium inlet.

10. The combined power generation system of claim 2, wherein the heat pump storage system further comprises a first control valve, a second control valve, a third control valve, and a fourth control valve, each of the first control valve, the second control valve, the third control valve, and the fourth control valve having a first port, a second port, and a third port, the first port in switching communication with the second port and the third port;

the first port of the first control valve is connected with the first port of the high-temperature heat accumulator, and the second port of the first control valve is connected with the second end of the third conveying pipe;

the first port of the second control valve is connected with the second port of the high-temperature heat accumulator, and the second port of the second control valve is connected with the first end of the second conveying pipe;

the first valve port of the third control valve is connected with the first port of the low-temperature heat accumulator, and the second valve port of the third control valve is connected with a working medium inlet of the compressor;

the first valve port of the fourth control valve is connected with the second port of the low-temperature heat accumulator, and the second valve port of the fourth control valve is connected with a working medium inlet of the compressor;

the third valve port of each of the first control valve and the second control valve is connected with the working medium inlet of the first turbine, and the third valve port of each of the third control valve and the fourth control valve is connected with the working medium outlet of the first turbine;

optionally, each of the first, second, third and fourth control valves is an electromagnetic three-way valve or a pneumatic three-way valve.

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