Cold energy power generation system and cold energy power generation process

Abstract

The invention provides a cold energy power generation system and a cold energy power generation process, and relates to the technical field of cold energy power generation. The cold energy power generation system comprises an intermediate medium power generation loop, a liquid air power generation loop and a high-temperature air power generation loop. According to the cold energy power generation system, heat exchange power generation is conducted through the low-pressure LNG source and the intermediate medium in the intermediate medium power generation loop, the problems that high-pressure LNG cold energy is not fully utilized and the operation temperature fluctuation is large are solved, and therefore the power generation amount and the power generation stability are improved; meanwhile, according to the cold energy power generation system, an intermediate medium is used as a cold energy transmission carrier between low-pressure LNG and air in a liquid air power generation loop, and the safety of the power generation process is effectively improved; and the high-temperature air power generation loop can continuously generate power by using cold energy of low-temperature liquid air in the liquid air power generation loop, so that the power generation amount can still be effectively increased when the liquid air power generation loop is in an intermittent state.

Description

Technical Field

[0001] The present invention relates to the technical field of cold energy power generation, and in particular to a cold energy power generation system and a cold energy power generation process. Background Art

[0002] The cold energy power generation process uses the cold energy of low-temperature substances (refrigerants) to liquefy the intermediate medium and compressed air through heat exchange, and then releases the cold energy of the intermediate medium and compressed air through processes such as pressurization, gasification, and expansion power generation to generate electricity.

[0003] The cold energy power generation process usually uses high-pressure and low-temperature LNG (liquefied natural gas) as a refrigerant to exchange heat with the intermediate medium and compressed air respectively. Taking the intermediate medium heat exchange process as an example, during the heat exchange, the cold capacity of the high-pressure LNG is first used to convert the gaseous intermediate medium and compressed air into a low-temperature liquid intermediate medium and liquid air respectively, and then the low-temperature liquid intermediate medium is pressurized by a pump and enters the intermediate medium vaporizer, and heat is exchanged with seawater to generate a gaseous intermediate medium. The gaseous intermediate medium then enters the turbine generator for expansion process to generate electricity. After the expansion process operation, the intermediate medium becomes a low-pressure and low-temperature gaseous intermediate medium, and then enters the LNG-intermediate medium vaporizer for heat exchange, and finally condenses into a liquid intermediate medium, and so on for reciprocating cycle operation.

[0004] However, since LNG has absorbed BOG (natural gas formed by the evaporation of part of the liquefied gas due to external heat input) and increased pressure, the temperature of high-pressure LNG rises before heat exchange, generally between -140 and -110°C, which results in the cold energy of LNG not being fully released and utilized during the heat exchange process, reducing the cold energy utilization efficiency and power generation. In addition, due to the complex upstream operating conditions of high-pressure LNG, large changes in BOG processing conditions, and large fluctuations in the output of high-pressure NG (natural gas), the operating temperature of high-pressure LNG fluctuates greatly, and there is an instability in the amount of cold energy provided. In addition, in the existing cold energy power generation process, high-pressure LNG directly exchanges heat with compressed air when exchanging heat with compressed air, and there is a safety risk of LNG leaking into the compressed air. Summary of the invention

[0005] The purpose of the present invention is to provide a cold energy power generation system and a cold energy power generation process to alleviate the problems existing in the prior art when using high-pressure LNG for cold energy power generation, namely, the temperature of the high-pressure LNG increases before heat exchange, which leads to the inability to fully release and utilize the cold energy; the cold energy utilization efficiency and power generation are reduced, and the operating temperature of the high-pressure LNG fluctuates greatly, resulting in unstable cold energy supply; in addition, the high-pressure LNG directly exchanges heat with the compressed air when exchanging heat with the compressed air, and there is a safety risk of LNG leaking into the compressed air.

[0006] In a first aspect, the present invention provides a cold energy power generation system, including an intermediate medium power generation circuit, a liquid air power generation circuit and a high temperature air power generation circuit; The intermediate medium power generation circuit includes a low-pressure LNG source, an intermediate medium source, an LNG intermediate medium heat exchange component, a heat exchange medium source, an intermediate medium heat exchange medium heat exchange component, a heat source component, an intermediate medium heat source heat exchange component and an intermediate medium generator component; The low-pressure LNG source, the LNG intermediate medium heat exchange component, the intermediate medium source, the intermediate medium heat exchange component, the intermediate medium heat source heat exchange component and the intermediate medium generator component are sequentially connected, and the intermediate medium generator component is connected to the LNG intermediate medium heat exchange component to form the intermediate medium power generation circuit; The LNG intermediate medium heat exchange component is used to exchange heat between low-pressure LNG and intermediate medium to cool the intermediate medium to form a low-temperature liquid intermediate medium; the intermediate medium heat exchange medium heat exchange component is connected to the heat exchange medium source, and is used to exchange heat between the low-temperature liquid intermediate medium and the heat exchange medium to preliminarily heat the low-temperature liquid intermediate medium; the intermediate medium heat source heat exchange component is connected to the heat source component, and is used to exchange heat between the intermediate medium and the heat source to reheat the preliminarily heated intermediate medium; the intermediate medium generator component is used to receive the high-temperature intermediate medium after reheating and expand it to generate electricity; The liquid air power generation circuit includes a compressed air supply component, an air heat exchange medium heat exchange component, a heat exchanger 10, a liquid air generator and a liquid air tank; The compressed air supply assembly, the air heat exchange medium heat exchange assembly, the liquid air generator, the heat exchanger 10 and the liquid air tank are connected in sequence, and the liquid air tank is connected to the compressed air supply assembly to form the liquid air power generation circuit; The air heat exchange medium heat exchange component is connected to the intermediate medium heat exchange medium heat exchange component, and is used for exchanging heat between compressed air and heat exchange medium, so as to cool the compressed air to form low-temperature air; the heat exchanger 10 is connected to the liquid air tank, and is used for exchanging heat between gas-liquid two-phase low-temperature air and low-temperature low-pressure air, so as to form low-temperature liquid air from gas-liquid two-phase low-temperature air; the liquid air generator is used for receiving low-temperature liquid air and performing decompression power generation; the liquid air tank is used for receiving and storing low-temperature liquid air after the liquid air generator generates power; The high-temperature air power generation circuit includes a liquid air heat exchange medium heat exchange component, an air heat source heat exchange component, a high-temperature air generator and a liquid air pump; The liquid air tank, the liquid air pump, the liquid air heat exchange medium heat exchange component, the air heat source heat exchange component and the high-temperature air generator are sequentially connected to form the high-temperature air power generation circuit; The liquid air heat exchange medium heat exchange component is connected to the heat exchange medium source, and is used for heat exchange between the heat exchange medium and the low-temperature liquid air from the liquid air tank to increase the temperature of the liquid air and reduce the temperature of the heat exchange medium; the air heat source heat exchange component is connected to the heat source component, and is used for heat exchange between the low-temperature gaseous air and the heat source to increase the temperature of the low-temperature gaseous air and convert it into high-temperature gaseous air; the high-temperature air generator is used to receive high-temperature gaseous air and expand it to generate electricity.

[0007] In an optional embodiment, the intermediate medium source includes a first medium source, the LNG intermediate medium heat exchange assembly includes a heat exchanger 1, the heat exchange medium source includes a first heat exchange medium pressurization structure, the intermediate medium heat exchange medium heat exchange assembly includes a heat exchanger 2, the heat source assembly includes a low-temperature heat source and a high-temperature heat source, the intermediate medium heat source heat exchange assembly includes a heat exchanger 3, and the intermediate medium generator assembly includes a first generator; The low-pressure LNG source, heat exchanger 1, first medium source, heat exchanger 2, heat exchanger 3 and the first generator are connected in sequence, and the first generator is connected to the heat exchanger 1; the heat exchanger 1 is used for heat exchange between the low-pressure LNG source and the first medium, so that the gaseous first medium forms a low-temperature liquid first medium; the heat exchanger 2 is connected to the first heat exchange medium pressurization structure, and is used for heat exchange between the low-temperature liquid first medium and the heat exchange medium, so that the low-temperature liquid first medium is initially heated to become the gaseous first medium; the heat exchanger 3 is connected to the high-temperature heat source, and is used for heat exchange between the gaseous first medium and the high-temperature heat source, so that the gaseous first medium is heated to become the high-temperature gaseous first medium; the first generator is used for receiving the high-temperature gaseous first medium and expanding it to generate electricity; The intermediate medium source further includes a second medium source, the LNG intermediate medium heat exchange assembly further includes a heat exchanger 4, the heat exchange medium source further includes a third heat exchange medium pressurizing structure, the intermediate medium heat exchange medium heat exchange assembly includes a heat exchanger 17, the intermediate medium heat source heat exchange assembly further includes a heat exchanger 5 and a heat exchanger 6, and the intermediate medium generator assembly further includes a second generator; The low-pressure LNG source, heat exchanger four, heat exchanger seventeen, second medium source, heat exchanger five, heat exchanger six and the second generator are connected in sequence, and the second generator is connected to the heat exchanger four; the heat exchanger four is used for heat exchange between the low-pressure LNG source and the second medium, so that the second medium is initially cooled down to form a low-temperature liquid second medium; the heat exchanger seventeen is connected to the third heat exchange medium boosting structure, and is used for cold exchange between the low-temperature liquid second medium and the heat exchange medium, so that the low-temperature liquid second medium is cooled again; the heat exchanger five is connected to the low-temperature heat source, and is used for heat exchange between the low-temperature liquid second medium and the low-temperature heat source, so that the low-temperature liquid second medium is initially heated up to become a normal-temperature second medium; the heat exchanger six is ​​connected to the high-temperature heat source, and is used for heat exchange between the normal-temperature second medium and the high-temperature heat source, so that the normal-temperature second medium is heated up to become a high-temperature second medium; the second generator is used for receiving the high-temperature second medium and expanding it to generate electricity.

[0008] In an optional embodiment, the intermediate medium heat exchange medium heat exchange component further includes a heat exchanger seven, the heat exchange medium source further includes a second heat exchange medium pressurizing structure, a branch pipeline is provided between the first generator and the first medium source, the heat exchanger seven is provided on the branch pipeline, and the heat exchanger seven, the second heat exchange medium pressurizing structure and the liquid air heat exchange medium heat exchange component are connected to form a first circulation heat exchange loop; The heat exchanger 7 is used for exchanging heat between the heat exchange medium and the low-temperature gaseous first medium from the first generator, so as to cool the low-temperature gaseous first medium to form a low-temperature liquid first medium.

[0009] In an optional embodiment, the air heat exchange medium heat exchange assembly includes heat exchanger eight and heat exchanger nine; The compressed air supply assembly, heat exchanger eight, heat exchanger nine, heat exchanger ten and the liquid air generator are connected in sequence, and the heat exchanger eight, heat exchanger two and the first heat exchange medium boosting structure are connected to form a second circulating heat exchange loop; The heat exchange medium source also includes a first heat exchange medium tank, and the heat exchanger nine, the first heat exchange medium tank and the liquid air heat exchange medium heat exchange component are connected to form a third circulating heat exchange loop; The compressed air supply assembly and the liquid air tank are both connected to the heat exchanger ten, and the heat exchanger ten is used to exchange heat between the low-temperature liquid air that has passed through the heat exchanger nine and the low-temperature gaseous air from the liquid air tank to further cool the low-temperature liquid air.

[0010] In an optional embodiment, the liquid air heat exchange medium heat exchange component includes heat exchanger 11, heat exchanger 12 and heat exchanger 13, and the air heat source heat exchange component includes heat exchanger 14 and heat exchanger 15; The liquid air tank, the heat exchanger 11, the heat exchanger 12, the heat exchanger 14, and the heat exchanger 15 are sequentially connected to the high-temperature air generator, and the heat exchanger 13 is connected between the liquid air tank and the inlet of the heat exchanger 12; The heat exchanger nine, the first heat exchange medium tank and the heat exchanger eleven are connected to form the third circulating heat exchange loop; The heat exchanger 12, the heat exchanger 17 and the third heat exchange medium pressurizing structure are connected to form a fourth circulation heat exchange loop; The heat exchanger 14 is in communication with the low-temperature heat source; The heat exchanger fifteen is connected to the high-temperature heat source.

[0011] In an optional embodiment, the liquid air power generation circuit further includes an air rewarmer; A first valve is provided on the pipeline between the liquid air generator and the liquid air tank, the liquid air tank is connected to the air rewarmer, and a second valve is provided on the pipeline between the liquid air tank and the air rewarmer, and the second valve is used to open when the first valve is closed.

[0012] In an optional embodiment, the air rewarmer is connected between the inlet and outlet of the low-temperature heat source, and a third valve is provided on the pipeline between the air rewarmer and the inlet of the low-temperature heat source, and the third valve is used to open when the first valve is closed.

[0013] In an optional embodiment, a fourth valve is provided on the pipeline between the first medium source and the second heat exchanger, and the fourth valve is used to close when the first valve is closed; The intermediate medium heat source heat exchange assembly further includes a heat exchanger 16, the pipeline between the first medium source and the fourth valve is connected to the pipeline between the heat exchanger 2 and the heat exchanger 3, and the heat exchanger 16 is connected between the inlet and the outlet of the low-temperature heat source; A fifth valve is provided on the pipeline between the first medium source and the fourth valve and the pipeline between the heat exchanger sixteen, and a sixth valve is provided on the pipeline between the outlet of the low-temperature heat source and the heat exchanger sixteen. The fifth valve and the sixth valve are used to open when the first valve is closed.

[0014] In an optional embodiment, a seventh valve is provided on the pipeline between the heat exchanger eleven and the heat exchanger nine, and the seventh valve is used to close when the first valve is closed; The heat exchange medium source also includes a second heat exchange medium tank, the pipeline between the heat exchanger eleven and the seventh valve is connected to the second heat exchange medium tank, and an eighth valve is provided on the pipeline between the heat exchanger eleven and the second heat exchange medium tank, and the eighth valve is used to open when the first valve is closed.

[0015] In a second aspect, the present invention provides a cold energy power generation process, using the cold energy power generation system as described in any one of the above embodiments, comprising: The intermediate medium power generation circuit and the high-temperature air power generation circuit are used to continuously generate electricity at different time periods, and the liquid air power generation circuit can generate electricity continuously and intermittently.

[0016] The cold energy power generation system provided by the present invention comprises an intermediate medium power generation circuit, a liquid air power generation circuit and a high temperature air power generation circuit; the intermediate medium power generation circuit comprises a low-pressure LNG source, an intermediate medium source, an LNG intermediate medium heat exchange component, a heat exchange medium source, an intermediate medium heat exchange medium heat exchange component, a heat source component, an intermediate medium heat source heat exchange component and an intermediate medium generator component; the low-pressure LNG source, the LNG intermediate medium heat exchange component, the intermediate medium source, the intermediate medium heat exchange medium heat exchange component, the intermediate medium heat source heat exchange component and the intermediate medium generator component are connected in sequence, and the intermediate medium generator component is connected with the LNG intermediate medium heat exchange component to form an intermediate medium power generation circuit; the LNG intermediate medium heat exchange component The components are used for heat exchange between low-pressure LNG and intermediate medium to cool the intermediate medium to form a low-temperature liquid intermediate medium; the intermediate medium heat exchange medium heat exchange component is connected to the heat exchange medium source, and is used for heat exchange between the low-temperature liquid intermediate medium and the heat exchange medium to preliminarily heat the low-temperature liquid intermediate medium; the intermediate medium heat source heat exchange component is connected to the heat source component, and is used for heat exchange between the intermediate medium and the heat source to reheat the preliminarily heated intermediate medium; the intermediate medium generator component is used to receive the high-temperature intermediate medium after reheating and expand it to generate electricity; the liquid air power generation circuit includes a compressed air supply component, an air heat exchange medium heat exchange component, a heat exchanger 10, a liquid air generator and a liquid air tank; the compressed air supply component, the air heat exchange medium heat exchange component, the heat exchanger 10, the liquid air generator and the liquid air tank The air heat exchange medium heat exchange component, the liquid air generator, the heat exchanger 10 and the liquid air tank are connected in sequence, and the liquid air tank is connected to the compressed air supply component to form a liquid air power generation circuit; the air heat exchange medium heat exchange component is connected to the intermediate medium heat exchange medium heat exchange component, and is used to exchange heat between the compressed air and the heat exchange medium to cool the compressed air to form low-temperature air; the heat exchanger 10 is connected to the liquid air tank, and is used to exchange heat between the gas-liquid two-phase low-temperature air and the low-temperature and low-pressure air to form low-temperature liquid air in the gas-liquid two-phase; the liquid air generator is used to receive the low-temperature liquid air and perform decompression power generation; the liquid air tank is used to receive and store the low-temperature liquid air after the liquid air generator generates power; The warm air power generation circuit includes a liquid air heat exchange medium heat exchange component, an air heat source heat exchange component, a high-temperature air generator and a liquid air pump; the liquid air tank, the liquid air heat exchange medium heat exchange component, the air heat source heat exchange component and the high-temperature air generator are connected in sequence to form a high-temperature air power generation circuit; the liquid air heat exchange medium heat exchange component is connected to the heat exchange medium source, and is used to heat the heat exchange medium and the low-temperature liquid air from the liquid air tank to increase the temperature of the liquid air and cool the heat exchange medium; the air heat source heat exchange component is connected to the heat source component, and is used for heat exchange between low-temperature gaseous air and the heat source to heat up the low-temperature gaseous air and convert it into high-temperature gaseous air; the high-temperature air generator is used to receive high-temperature gaseous air and expand it to generate electricity.

[0017] The cold energy power generation system provided by the present invention is used for cold energy power generation. During the power generation process, the intermediate medium power generation circuit, the liquid air power generation circuit and the high-temperature air power generation circuit can be connected. Then, in the intermediate medium power generation circuit, the LNG intermediate medium heat exchange component can be used to exchange heat between the low-pressure LNG and the intermediate medium, so that the intermediate medium absorbs the cold of the low-pressure LNG to cool down and form a low-temperature liquid intermediate medium. Then, the intermediate medium heat exchange component is used to exchange heat between the low-temperature liquid intermediate medium and the heat exchange medium, so that the low-temperature liquid intermediate medium absorbs the heat of the heat exchange medium and initially heats up to become a gaseous intermediate medium, and at the same time, the heat exchange medium cools down to form a low-temperature heat exchange medium. After the gaseous intermediate medium continues to flow in the intermediate medium power generation circuit, it will exchange heat with the heat source at the intermediate medium heat source heat exchange component, thereby further heating up to form a high-temperature gaseous intermediate medium. After the high-temperature gaseous intermediate medium continues to flow, it will enter the intermediate medium generator component to expand and generate electricity, thereby realizing the process of the intermediate medium power generation circuit using the cold of low-pressure LNG to generate electricity. After the high-temperature gaseous intermediate medium expands to generate electricity, a low-temperature gaseous intermediate medium will be generated. Since the intermediate medium generator assembly is connected to the LNG intermediate medium heat exchange assembly, the low-temperature gaseous intermediate medium will flow back to the LNG intermediate medium heat exchange assembly to exchange heat with the low-pressure LNG again, and then circulate to generate electricity. Compared with the prior art that uses high-pressure LNG to generate electricity, the cold energy power generation system provided by the present invention uses a low-pressure LNG source for heat exchange and power generation, which can effectively avoid the problem of insufficient utilization of high-pressure LNG cold energy and large fluctuations in operating temperature, thereby improving power generation and power generation stability.

[0018] In addition, the cold energy power generation system provided by the present invention can also use the air heat exchange medium heat exchange component in the liquid air power generation circuit to exchange heat between the pre-treated low-temperature compressed air and the low-temperature heat exchange medium formed after heat exchange at the intermediate medium heat exchange medium heat exchange component, so that the low-temperature compressed air absorbs the cold of the heat exchange medium and further cools down to form low-temperature liquid air, and then the low-temperature liquid air will enter the liquid air generator to reduce pressure and generate electricity, so as to realize the process of using low-temperature compressed air to generate electricity in the liquid air power generation circuit. The compressed air after power generation will generate low-pressure low-temperature liquid air, which will be stored in the liquid air tank. Since the liquid air tank is connected to the compressed air supply component, the low-pressure low-temperature liquid air will also flow back to the air heat exchange medium heat exchange component to exchange heat with the low-temperature heat exchange medium again, and then circulate power generation. Compared with the process of generating electricity by direct heat exchange between high-pressure LNG and compressed air in the prior art, the cold energy power generation system provided by the present invention utilizes the heat exchange medium in the intermediate medium power generation circuit as the cold energy transmission carrier between the low-pressure LNG and the compressed air in the liquid air power generation circuit, thereby avoiding the safety risk of LNG leaking into the compressed air and effectively improving the safety of the cold energy power generation process.

[0019] Since the liquid air power generation circuit uses compressed air for power generation in an intermittent operation, the liquid air power generation circuit does not continuously generate electricity. Regardless of whether the liquid air power generation circuit is in a power generation state or in a power generation stop state, the cold energy power generation system provided by the present invention can use the liquid air heat exchange medium heat exchange component in the high-temperature air power generation circuit to exchange heat between the low-temperature liquid air stored in the liquid air tank and the heat exchange medium at the heat exchange medium source, so that the low-temperature liquid air absorbs heat to increase the temperature to form low-temperature gaseous air, and then use the air heat source heat exchange component to exchange heat between the low-temperature gaseous air and the heat source, so that the low-temperature gaseous air is heated again to form high-temperature gaseous air, and the high-temperature gaseous air will then flow to the high-temperature air generator to expand and generate electricity, thereby realizing the process of the high-temperature air power generation circuit using the low-temperature liquid air and the heat source to generate electricity. Compared with the prior art, the cold energy power generation system provided by the present invention can also utilize the low-temperature liquid air generated in the high-temperature air power generation circuit and the liquid air power generation circuit to continuously generate electricity in the intermittent state during the liquid air power generation process, thereby ensuring the power generation. Even if the compressed air power generation process is an intermittent operation, the power generation can still be effectively increased.

[0020] Compared with the prior art, the cold energy power generation system provided by the present invention generates electricity through heat exchange between a low-pressure LNG source and an intermediate medium in an intermediate medium power generation circuit, which can avoid the problems of insufficient utilization of high-pressure LNG cold energy and large fluctuations in operating temperature, and can improve power generation and power generation stability. At the same time, the cold energy power generation system uses the intermediate medium as a cold energy transmission carrier between low-pressure LNG and air in the liquid air power generation circuit, which effectively improves the safety of the power generation process. In addition, the high-temperature air power generation circuit can use the low-temperature liquid air generated in the liquid air power generation circuit to continuously generate electricity, thereby effectively increasing the power generation when the liquid air power generation circuit is in an intermittent state.

[0021] The cold energy power generation process provided by the present invention applies the above-mentioned cold energy power generation system, including: using the intermediate medium power generation circuit and the high-temperature air power generation circuit to simultaneously perform continuous power generation, and using the liquid air power generation circuit to perform intermittent power generation. The cold energy power generation process provided by the present invention applies the above-mentioned cold energy power generation system, so the cold energy power generation process has the same beneficial effects as the above-mentioned cold energy power generation system. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions of the specific implementation methods of the present invention, the drawings of the specific implementation methods will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0023] Figure 1A schematic diagram of the structure of a cold energy power generation system provided in an embodiment of the present invention.

[0024] Icons: 1-intermediate medium power generation circuit; 10-low-pressure LNG source; 11-intermediate medium source; 110-first medium source; 1100-first medium pump; 111-second medium source; 1110-second medium pump; 12-LNG intermediate medium heat exchange assembly; 120-heat exchanger one; 121-heat exchanger four; 13-heat exchange medium source; 130-first heat exchange medium pressurization structure; 131-third heat exchange medium pressurization structure; 132-second heat exchange medium pressurization structure; 133-first heat exchange medium tank; 134-fourth heat exchange medium pressurization structure; 135-second heat exchange medium tank; 14- Intermediate medium heat exchanger medium heat exchanger assembly; 140-heat exchanger two; 141-heat exchanger seventeen; 142-heat exchanger seven; 15-heat source assembly; 150-low temperature heat source; 151-high temperature heat source; 152-low temperature heat source pump; 153-high temperature heat source pump; 16-intermediate medium heat source heat exchanger assembly; 160-heat exchanger three; 161-heat exchanger five; 162-heat exchanger six; 163-heat exchanger sixteen; 17-intermediate medium generator assembly; 170-first generator; 1700-distributor; 171-second generator; 18-fourth valve; 19-fifth valve; 190-sixth valve; 2-liquid air power generation circuit; 20-compressed air supply assembly; 200-air compressor unit 1; 201-air compressor unit heat exchanger; 202-air compressor unit 2; 203-air-air heat exchanger; 21-air heat exchange medium heat exchange assembly; 210-heat exchanger 8; 211-heat exchanger 9; 22-liquid air generator; 23-liquid air tank; 24-heat exchanger 10; 25-air reheater; 26-first valve; 27-second valve; 28-third valve; 3-high-temperature air power generation circuit; 30-liquid air heat exchange medium heat exchange component; 300-heat exchanger eleven; 301-heat exchanger twelve; 302-heat exchanger thirteen; 31-air heat source heat exchange component; 310-heat exchanger fourteen; 311-heat exchanger fifteen; 32-high-temperature air generator; 33-liquid air pump; 4-first circulation heat exchange circuit; 5-second circulation heat exchange circuit; 6-third circulation heat exchange circuit; 7-fourth circulation heat exchange circuit; 8-seventh valve; 9-eighth valve. DETAILED DESCRIPTION

[0025] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0026] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0027] Some embodiments of the present invention are described in detail below in conjunction with the accompanying drawings. In the absence of conflict, the following embodiments and features in the embodiments can be combined with each other.

[0028] Example: like Figure 1As shown, the cold energy power generation system provided in this embodiment includes an intermediate medium power generation circuit 1, a liquid air power generation circuit 2 and a high temperature air power generation circuit 3; the intermediate medium power generation circuit 1 includes a low-pressure LNG source 10, an intermediate medium source 11, an LNG intermediate medium heat exchange component 12, a heat exchange medium source 13, an intermediate medium heat exchange medium heat exchange component 14, a heat source component 15, an intermediate medium heat source heat exchange component 16 and an intermediate medium generator component 17; the low-pressure LNG source 10, the LNG intermediate medium heat exchange component 12, the intermediate medium source 11, the intermediate medium heat exchange medium heat exchange component 14, the intermediate medium heat source heat exchange component 16 and the intermediate medium generator component 17 are connected in sequence, and the intermediate medium generator component 17 is connected to the LNG intermediate medium. The intermediate medium heat exchange component 12 is connected to form an intermediate medium power generation circuit 1; the LNG intermediate medium heat exchange component 12 is used to exchange heat between the low-pressure LNG and the intermediate medium to cool the intermediate medium to form a low-temperature liquid intermediate medium; the intermediate medium heat exchange medium heat exchange component 14 is connected to the heat exchange medium source 13, and is used to exchange heat between the low-temperature liquid intermediate medium and the heat exchange medium to preliminarily heat the low-temperature liquid intermediate medium; the intermediate medium heat source heat exchange component 16 is connected to the heat source component 15, and is used to exchange heat between the intermediate medium and the heat source to reheat the preliminarily heated intermediate medium; the intermediate medium generator component 17 is used to receive the high-temperature intermediate medium after reheating and expand it to generate electricity; the liquid air power generation circuit 2 includes a compressed air supply component 20, an air The air heat exchange medium heat exchange component 21, the liquid air generator 22, the liquid air tank 23 and the heat exchanger 10 24; the compressed air supply component 20, the air heat exchange medium heat exchange component 21, the heat exchanger 10 24, the liquid air generator 22 and the liquid air tank 23 are connected in sequence, and the liquid air tank 23 is connected to the compressed air supply component 20 to form a liquid air power generation circuit 2; the air heat exchange medium heat exchange component 21 is connected to the intermediate medium heat exchange medium heat exchange component 14, which is used to exchange heat between the compressed air and the heat exchange medium to cool the compressed air to form low-temperature liquid air; the heat exchanger 10 24 is used to exchange heat between the deep-cold low-pressure gaseous air and the liquid saturated air to further cool the liquid air; the liquid air generator 22 is used to receive the low-temperature Liquid air is decompressed and generates electricity; the liquid air tank 23 is used to receive and store the low-temperature liquid air after the liquid air generator 22 generates electricity; the high-temperature air power generation circuit 3 includes a liquid air heat exchange medium heat exchange component 30, an air heat source heat exchange component 31, a high-temperature air generator 32 and a liquid air pump 33; the liquid air tank 23, the liquid air heat exchange medium heat exchange component 30, the liquid air pump 33, the air heat source heat exchange component 31 and the high-temperature air generator 32 are connected in sequence to form a high-temperature air power generation circuit 3; the liquid air heat exchange medium heat exchange component 30 is connected to the heat exchange medium source 13, and is used to heat the heat exchange medium and the low-temperature liquid air from the liquid air tank 23 to increase the temperature of the liquid air and reduce the temperature of the heat exchange medium;The air heat source heat exchange component 31 is connected to the heat source component 15, and is used to exchange heat between the low-temperature gaseous air and the heat source to heat the low-temperature gaseous air and convert it into high-temperature gaseous air; the high-temperature air generator 32 is used to receive the high-temperature gaseous air and expand it to generate electricity.

[0029] The cold energy power generation system provided in this embodiment is used for cold energy power generation. During the power generation process, the intermediate medium power generation circuit 1, the liquid air power generation circuit 2 and the high-temperature air power generation circuit 3 can be connected. Then, in the intermediate medium power generation circuit 1, the LNG intermediate medium heat exchange component 12 can be used to exchange heat between the low-pressure LNG and the intermediate medium, so that the intermediate medium absorbs the cold of the low-pressure LNG to cool down and form a low-temperature liquid intermediate medium. Then, the intermediate medium heat exchange component 14 is used to exchange heat between the low-temperature liquid intermediate medium and the heat exchange medium, so that the low-temperature liquid intermediate medium absorbs the heat of the heat exchange medium and initially heats up to a gaseous intermediate medium, and at the same time, the heat exchange medium cools down to form a low-temperature heat exchange medium. After the gaseous intermediate medium continues to flow in the intermediate medium power generation circuit 1, it will exchange heat with the heat source at the intermediate medium heat source heat exchange component 16, thereby further heating up to form a high-temperature gaseous intermediate medium. After the high-temperature gaseous intermediate medium continues to flow, it will enter the intermediate medium generator component 17 to expand and generate electricity, so as to realize the process of the intermediate medium power generation circuit 1 using the cold of low-pressure LNG to generate electricity. After the high-temperature gaseous intermediate medium expands to generate electricity, a low-temperature gaseous intermediate medium will be generated. Since the intermediate medium generator assembly 17 is connected to the LNG intermediate medium heat exchange assembly 12, the low-temperature gaseous intermediate medium will flow back to the LNG intermediate medium heat exchange assembly 12 to exchange heat with the low-pressure LNG again, and then circulate to generate electricity.

[0030] The above low temperatures are all relative to the temperature of the material before heat exchange. Compared with the prior art that uses high-pressure LNG to generate electricity, the cold energy power generation system provided in this embodiment uses a low-pressure LNG source 10 for heat exchange power generation, effectively avoiding the problems of insufficient utilization of high-pressure LNG cold energy and large fluctuations in operating temperature, thereby improving power generation and power generation stability.

[0031] Among them, the low pressure of low-pressure LNG is compared with the high-pressure LNG in the prior art. Its pressure is lower than that of the high-pressure LNG in the prior art. Correspondingly, the operating temperature of low-pressure LNG is also lower than that of high-pressure LNG. The operating temperature of low-pressure LNG is generally between -161 and -158 ° C. Compared with high-pressure LNG, its unit cold energy supply is more, thereby increasing the cold energy power generation and solving the problem of low cold energy power generation in the existing cold energy power generation process. In addition, the operating temperature of low-pressure LNG is relatively stable, and the operating pressure of low-pressure LNG is generally between 0.7 and 5MpaG, while the operating temperature of high-pressure LNG fluctuates greatly, generally between -140 and -110 ° C. Therefore, the cold energy power generation system provided in this embodiment can also solve the problems of large operating temperature fluctuations and unstable power generation caused by the use of high-pressure LNG in the prior art by using low-pressure LNG.

[0032] In addition, the cold energy power generation system provided in this embodiment can also use the air heat exchange medium heat exchange component 21 in the liquid air power generation circuit 2 to exchange heat between the pre-treated low-temperature compressed air and the low-temperature heat exchange medium after heat exchange from the intermediate medium heat exchange medium heat exchange component 14, so that the low-temperature compressed air absorbs the cold of the heat exchange medium and further cools down to form low-temperature liquid air, and then the low-temperature liquid air will enter the liquid air generator 22 for decompression and power generation, so as to realize the process of liquid air power generation circuit 2 using low-temperature compressed air to generate electricity. The compressed air after power generation will generate low-pressure low-temperature liquid air, which will be stored in the liquid air tank 23. The low-pressure deep-cold low-temperature gaseous air flashed by the liquid air tank 23 is connected to the compressed air supply component 20, and then a circulation operation is performed.

[0033] Compared with the process of generating electricity by direct heat exchange between high-pressure LNG and compressed air in the prior art, the cold energy power generation system provided in this embodiment uses the heat exchange medium in the intermediate medium power generation circuit 1 as a cold energy transmission carrier between low-pressure LNG and compressed air in the liquid air power generation circuit 2, thereby avoiding the safety risk of LNG leaking into the compressed air and effectively improving the safety of the cold energy power generation process.

[0034] The liquid air heat exchange medium heat exchange component 30 is used to exchange heat between the low-temperature liquid air stored in the liquid air tank 23 and the heat exchange medium at the heat exchange medium source 13, so that the low-temperature liquid air absorbs heat to rise in temperature to form low-temperature gaseous air. Then, the air heat source heat exchange component 31 is used to exchange heat between the low-temperature gaseous air and the heat source, so that the low-temperature gaseous air is heated again to form high-temperature gaseous air. The high-temperature gaseous air then flows to the high-temperature air generator 32 to expand and generate electricity, thereby realizing the process of the high-temperature air power generation circuit 3 generating electricity by heat exchange between the low-temperature liquid air and the heat source.

[0035] The above high temperatures are relative to the temperature of the material before heat exchange. Compared with the prior art, the cold energy power generation system provided in this embodiment can also use the low-temperature liquid air generated in the high-temperature air power generation circuit 3 and the liquid air power generation circuit 2 to continuously generate electricity in the intermittent state during the liquid air power generation process, thereby ensuring the power generation. Even if the compressed air power generation process is an intermittent operation, the power generation can still be effectively increased.

[0036] In summary, compared with the prior art, the cold energy power generation system provided in the present embodiment generates electricity by exchanging heat with the intermediate medium through the low-pressure LNG source 10 in the intermediate medium power generation circuit 1, which can avoid the problems of insufficient utilization of high-pressure LNG cold energy and large fluctuations in operating temperature, and can improve power generation and power generation stability. At the same time, the cold energy power generation system uses the intermediate medium as a cold energy transmission carrier between the low-pressure LNG and the air in the liquid air power generation circuit 2, which effectively improves the safety of the power generation process. In addition, the high-temperature air power generation circuit 3 can use the low-temperature liquid air generated in the liquid air power generation circuit 2 to continuously generate electricity, thereby effectively increasing the power generation when the liquid air power generation circuit 2 is in an intermittent state.

[0037] To improve process safety, the heat exchange medium is preferably an inert gas in this embodiment, and the heat exchange medium may include nitrogen. During the power generation process, the operating pressure of the heat exchange medium is generally controlled at 0.2~1.8MpaG.

[0038] In addition, based on the feasibility of process technology and equipment manufacturing technology and the effect of improving economic benefits, this embodiment preferably sets the inlet pressure of the high-temperature air generator 32 to 10.0~20.0MpaG and the inlet temperature of the high-temperature air generator 32 to 100~300℃.

[0039] like Figure 1As shown, the intermediate medium source 11 includes a first medium source 110, the LNG intermediate medium heat exchange assembly 12 includes a heat exchanger 1 120, the heat exchange medium source 13 includes a first heat exchange medium pressurization structure 130, the intermediate medium heat exchange medium heat exchange assembly 14 includes a heat exchanger 2 140, the heat source assembly 15 includes a low-temperature heat source 150 and a high-temperature heat source 151, the intermediate medium heat source heat exchange assembly 16 includes a heat exchanger 3 160, and the intermediate medium generator assembly 17 includes a first generator 170; the low-pressure LNG source 10, the heat exchanger 1 120, the first medium source 110, the heat exchanger 2 140, the heat exchanger 3 160 and the first generator 170 are connected in sequence, And the first generator 170 is connected to the heat exchanger 120; the heat exchanger 120 is used to exchange heat between the low-pressure LNG source 10 and the first medium, so that the first medium forms a low-temperature liquid first medium; the heat exchanger 2 140 is connected to the first heat exchange medium boosting structure 130, and is used to exchange heat between the low-temperature liquid first medium and the heat exchange medium, so that the low-temperature liquid first medium is initially heated up to become a gaseous first medium; the heat exchanger 3 160 is connected to the high-temperature heat source 151, and is used to exchange heat between the gaseous first medium and the high-temperature heat source 151, so that the gaseous first medium is heated up to become a high-temperature gaseous first medium; the first generator 170 is used to receive the high-temperature gaseous first medium and expand it to generate electricity.

[0040] The low temperature heat source 150 and the high temperature heat source 151 are relative, and the heat source temperature of the low temperature heat source 150 is lower than the heat source temperature of the high temperature heat source 151. In this embodiment, the low temperature heat source 150 may include at least one of seawater and water-ethylene glycol solution, and the high temperature heat source 151 may include at least one of hot water, high temperature hot oil, high temperature steam and hot lava.

[0041] The intermediate medium source 11 also includes a second medium source 111, the LNG intermediate medium heat exchange assembly 12 also includes a heat exchanger 4 121, the heat exchange medium source 13 also includes a third heat exchange medium pressurization structure 131, the intermediate medium heat exchange medium heat exchange assembly 14 includes a heat exchanger 17 141, the intermediate medium heat source heat exchange assembly 16 also includes a heat exchanger 5 161 and a heat exchanger 6 162, and the intermediate medium generator assembly 17 also includes a second generator 171; the low-pressure LNG source 10, the heat exchanger 4 121, the heat exchanger 17 141, the second medium source 111, the heat exchanger 5 161, the heat exchanger 6 162 and the second generator 171 are connected in sequence, and the second generator 171 is connected to the heat exchanger 4 121; the heat exchanger 4 121 is used to The low-pressure LNG source 10 exchanges heat with the second medium to initially cool the second medium to form a low-temperature liquid second medium; the heat exchanger 17 141 is connected to the third heat exchange medium pressurization structure 131, and is used for cold exchange of the low-temperature liquid second medium and the heat exchange medium to cool the low-temperature liquid second medium again; the heat exchanger 5 161 is connected to the low-temperature heat source 150, and is used for heat exchange of the low-temperature liquid second medium and the low-temperature heat source 150, so that the low-temperature liquid second medium is initially heated to become a room-temperature second medium; the heat exchanger 6 162 is connected to the high-temperature heat source 151, and is used for heat exchange of the room-temperature second medium and the high-temperature heat source 151, so that the room-temperature second medium is heated to become a high-temperature second medium; the second generator 171 is used to receive the high-temperature second medium and expand it to generate electricity.

[0042] Among them, the low-pressure LNG source 10, the heat exchanger 1 120, the first medium source 110, the heat exchanger 2 140, the heat exchanger 3 160 and the first generator 170 are connected in sequence to form a first medium power generation path. Among them, the first generator 170 can also be connected to the heat exchanger 1 120, so that the low-temperature gaseous first medium formed after power generation at the first generator 170 can flow to the heat exchanger 1 120, and then continue to exchange heat and cool with the low-pressure LNG source 10 at the heat exchanger 1 120 to form a low-temperature liquid intermediate first medium, and then enter the power generation cycle process to achieve the recycling of the first medium.

[0043] Correspondingly, the low-pressure LNG source 10, the heat exchanger 121, the heat exchanger 141, the second medium source 111, the heat exchanger 161, the heat exchanger 162 and the second generator 171 are connected in sequence to form a second medium power generation path. Among them, the second generator 171 can also be connected to the heat exchanger 121, so that the low-temperature gaseous second medium formed after the second generator 171 generates electricity can flow to the heat exchanger 121, and then continue to exchange heat and cool with the low-pressure LNG source 10 at the heat exchanger 121 to form a low-temperature liquid intermediate second medium, and then enter the power generation cycle process to achieve the recycling of the second medium.

[0044] The first medium may include ethane and a mixture. The mixture may be a mixture of methane and ethane. During the power generation process, the operating pressure at the first medium is generally controlled at 0.1~0.3MpaG, and the operating temperature is controlled between -110~-40°C. The second medium may include propane, methanol, ammonia and carbon dioxide. During the power generation process, the operating pressure at the second medium is generally controlled at 0.2~0.8MpaG, and the operating temperature is controlled between -60~20°C.

[0045] like Figure 1 As shown, the heat exchanger 121 can also be connected to an NG (natural gas) discharge pipeline. The low-pressure LNG from the low-pressure LNG source 10 passes through the heat exchanger 1 120 and the heat exchanger 121 in sequence, and is respectively heat-exchanged with the first medium and the second medium to be gasified to generate low-pressure NG. After the low-pressure NG meets the process requirements, it is transported out through the NG (natural gas) discharge pipeline.

[0046] In addition, if Figure 1 As shown, a first medium pump 1100 may also be provided on the pipeline between the first medium source 110 and the second heat exchanger 140. After being pressurized by the first medium pump 1100, the material from the first medium source 110 enters the second heat exchanger 140 and the third heat exchanger 160 in sequence, and exchanges heat with the heat exchange medium and the high-temperature heat source 151 respectively, and then the low-temperature first medium generates the high-temperature first medium, and then enters the first generator 170 for expansion and power generation. After the high-temperature first medium expands, it generates a low-pressure and low-temperature gaseous first medium, and this low-pressure and low-temperature gaseous first medium then enters the first heat exchanger 120 for heat exchange with the low-pressure LNG, and then generates a low-temperature liquid first medium, and then enters the first medium source 110 for circulation.

[0047] In this process, the cold energy power generation system provided in this embodiment utilizes the heat exchange medium and the heat source to successively exchange heat with the first medium, thereby effectively increasing the temperature of the first medium and increasing the power generation.

[0048] In this embodiment, the heat exchanger 4 121 and the heat exchanger 17 141 are connected through a pipeline. Figure 1 As shown in the figure, the two positions marked A are both located in the above-mentioned pipeline, and the two positions marked A are connected to each other. Figure 1As shown, a second medium pump 1110 may also be provided on the pipeline between the second medium source 111 and the heat exchanger 5 161. After being pressurized by the second medium pump 1110, the second medium from the second medium source 111 enters the heat exchanger 5 161 and the heat exchanger 6 162 in sequence, and exchanges heat with the low-temperature heat source 150 and the high-temperature heat source 151 respectively, and then the low-temperature second medium generates a high-temperature second medium, and then enters the second generator 171 for expansion and power generation. After the high-temperature second medium expands, it generates a low-pressure and low-temperature gaseous second medium, and this low-pressure and low-temperature gaseous second medium enters the heat exchanger 4 121 and the heat exchanger 17 141 in sequence for heat exchange. After the heat exchange, the low-pressure and low-temperature gaseous second medium generates a low-temperature liquid second medium, and finally the low-temperature liquid second medium enters the second medium source 111 for the next cycle operation.

[0049] In this process, the cold energy power generation system provided in this embodiment utilizes shallow cooling to increase the temperature of the second medium and increase the power generation.

[0050] The first generator 170 and the second generator 171 may both be turbine generators.

[0051] Further, such as Figure 1 As shown, the intermediate medium heat exchange medium heat exchange component 14 also includes a heat exchanger 142, the heat exchange medium source 13 also includes a second heat exchange medium boosting structure 132, a branch pipeline is provided between the first generator 170 and the first medium source 110, the heat exchanger 142 is provided on the branch pipeline, and the heat exchanger 142, the second heat exchange medium boosting structure 132 and the liquid air heat exchange medium heat exchange component 30 are connected to form a first circulation heat exchange loop 4; the heat exchanger 142 is used for heat exchange between the heat exchange medium and the low-temperature gaseous first medium from the first generator 170, so as to cool the low-temperature gaseous first medium to form a low-temperature liquid first medium.

[0052] The first circulating heat exchange loop 4 is used to utilize the low temperature of the heat exchange medium to heat exchange and cool down the low-temperature gaseous first medium after the first generator 170 generates electricity, so that the first medium becomes a low-temperature liquid first medium and flows to the first medium source 110 for recycling.

[0053] Specifically, Figure 1As shown, a distributor 1700 may be provided on the pipeline between the first generator 170 and the heat exchanger 120, and the distributor 1700 is connected to the heat exchanger 142 through a pipeline to achieve the connection between the first generator 170 and the heat exchanger 142. When the high-temperature first medium expands to generate a low-pressure and low-temperature gaseous first medium, the low-pressure and low-temperature gaseous first medium first enters the distributor 1700 for distribution and is divided into two paths, the first path flows to the heat exchanger 120, and the second path first enters the heat exchanger 142 for heat exchange with the low-temperature heat exchange medium. At this time, the low-temperature gaseous first medium generates a low-temperature liquid first medium, and the low-temperature liquid first medium is mixed with the low-temperature liquid first medium at the heat exchanger 120 and enters the first medium source 110 to perform the next cycle operation.

[0054] In this process, the cold energy power generation system provided in this embodiment utilizes the heat exchange medium to exchange heat with the first medium, so that the first medium is further cooled down, thereby effectively improving the utilization rate of the first medium.

[0055] In this embodiment, if Figure 1 As shown, the air heat exchange medium heat exchange component 21 includes a heat exchanger eight 210 and a heat exchanger nine 211; the compressed air supply component 20, the heat exchanger eight 210, the heat exchanger nine 211, the heat exchanger ten 24 and the liquid air generator 22 are connected in sequence, and the heat exchanger eight 210, the heat exchanger two 140 and the first heat exchange medium boosting structure 130 are connected to form a second circulation heat exchange loop 5; the heat exchange medium source 13 also includes a first heat exchange medium tank 133, the heat exchanger nine 211, the first heat exchange medium tank 133 and the liquid air heat exchange medium heat exchange component 30 are connected to form a third circulation heat exchange loop 6; the compressed air supply component 20 and the liquid air tank 23 are both connected to the heat exchanger ten 24, and the heat exchanger ten 24 is used to heat the low-temperature liquid air that has been heat exchanged by the heat exchanger nine 211 and the low-temperature gaseous air from the liquid air tank 23, so as to further cool the low-temperature liquid air.

[0056] The compressed air supply assembly 20 is used to compress normal pressure air into compressed air, the heat exchanger eight 210 and the heat exchanger nine 211 cool the compressed air in turn, the heat exchanger ten 24 is used to cool the cooled compressed air again to form low-temperature liquid air, and the liquid air generator 22 is used to generate electricity using the low-temperature liquid air.

[0057] In the second circulating heat exchange loop 5, the heat exchange medium from the first heat exchange medium boosting structure 130 enters the heat exchanger 2 140 after being boosted to perform heat exchange operation with the first medium, generating a deep cold low temperature heat exchange medium, and then the deep cold low temperature heat exchange medium enters the heat exchanger 8 210, and the heat exchange medium after heat exchange enters the first heat exchange medium boosting structure 130 again for the next cycle operation. It can be seen that the second circulating heat exchange loop 5 is used to transfer the cold energy after the first medium and the low pressure LNG are exchanged to the high pressure low temperature compressed air formed after the compressed air supply component 20 is processed, so that the first medium is used as an intermediate medium, and the cold energy of the low pressure LNG is used to cool the high pressure low temperature compressed air, so as to realize indirect heat exchange between the low pressure LNG and the compressed air, effectively prevent LNG from leaking into the compressed air, and improve the process safety.

[0058] The third circulating heat exchange loop 6 can use the coldness of the liquid air at the liquid air heat exchange medium heat exchange component 30 in the high-temperature air power generation loop 3 to cool the heat exchange medium flowing out of the first heat exchange medium tank 133, thereby exchanging the shallow low-temperature heat exchange medium into a deep low-temperature heat exchange medium, and then using the heat exchanger nine 211 to exchange the deep low-temperature heat exchange medium with the high-temperature low-pressure compressed air, so that the high-temperature low-pressure compressed air is cooled again, so as to facilitate the subsequent high-temperature low-pressure compressed air cooling to form liquid air. In addition, the shallow low-temperature heat exchange medium after heat exchange through the heat exchanger nine 211 can also circulate back to the first heat exchange medium tank 133, and then enter the circulating heat exchange process.

[0059] It can be seen that the third circulating heat exchange loop 6 can use the heat exchange medium as an intermediate medium to transport the cold in the high-temperature air power generation loop 3, thereby making full use of the cold in the cold energy power generation system and effectively improving the power generation efficiency.

[0060] Since the compressed air supply assembly 20 and the liquid air tank 23 are both connected to the heat exchanger 10 24, the cold energy carried by the low-temperature, low-pressure gaseous air flashed out and stored in the liquid air tank 23 after power generation can be used by the heat exchanger 10 24 to cool down the low-temperature compressed air at the outlet of the heat exchanger 9 211, so that the low-temperature saturated liquid air is cooled to form low-temperature supercooled liquid air. At the same time, the heat exchanger 10 24 can also transport the low-temperature, low-pressure gaseous air heated by heat exchange to the compressed air supply assembly 20, so that the low-temperature, low-pressure gaseous air enters the compressed air circulation power generation process. In this process, the surplus cold energy in the compressed air heat exchange process can be fully utilized to effectively cool down the compressed air, and the cold energy in the cold energy power generation system can also be fully utilized to effectively improve the heat exchange efficiency and power generation efficiency.

[0061] like Figure 1As shown, the compressed air supply assembly 20 may include an air compressor unit 1 200, an air compressor unit heat exchanger 201, an air compressor unit 202 and an air-to-air heat exchanger 203 which are connected in sequence. The air-to-air heat exchanger 203 in the compressed air supply assembly 20 is connected to the heat exchanger 10 24, and the pipeline between the air compressor unit heat exchanger 201 and the air compressor unit 202 may also be connected to the air-to-air heat exchanger 203 through a branch pipeline. At this time, the heat exchange and power generation process of the liquid air power generation circuit 2 is as follows: the air from normal pressure and normal temperature is pressurized by the air compressor unit 1 200, enters the air compressor unit heat exchanger 201, exchanges heat with the refrigerant from the high-temperature heat source pump 153, and then enters the air compressor unit 2 202 for pressurization. The pressurized medium-pressure compressed air enters the air-to-air heat exchanger 203, the heat exchanger eight 210, the heat exchanger nine 211, and the heat exchanger ten 24 in turn, and exchanges heat with the shallowly cooled low-temperature air at the air-to-air heat exchanger 203, the heat exchange medium at the heat exchanger eight 210, the heat exchange medium at the heat exchanger nine 211, and the deeply cooled low-temperature gaseous air at the heat exchanger ten 24, respectively, to generate medium-pressure low-temperature liquid air from the medium-pressure compressed air, and finally the medium-pressure low-temperature liquid air enters the liquid air generator 22 for decompression and power generation. The low-pressure and low-temperature air generated after the reduced-pressure power generation enters the liquid air tank 23 to complete the cold storage operation. At the same time, the liquid air tank 23 will flash to form low-temperature and low-pressure gaseous air. The flashed low-temperature and low-pressure gaseous air will enter the heat exchanger 10 24 and the air-to-air heat exchanger 203 in turn, and exchange heat with the low-temperature liquid air and the medium-pressure compressed air respectively, and then flow back to the air compressor unit 202 through the branch pipe for pressurization circulation treatment.

[0062] It should be noted that the low pressure, medium pressure and high pressure in this embodiment are all relative to the original pressure before the pressure change of the substance occurs. Based on the improvement of process feasibility and economic benefits, this embodiment preferably controls the operating pressure at the outlet of the air compressor group in the compressed air supply component 20 to 3.5~12MpaG; the compressed air temperature at the interstage heat exchange outlet of the air compressor group is 5~-10℃; the liquid air storage pressure at the liquid air tank 23 is between 0.05~2.0MpaG, the liquid air storage temperature is between -144~-190℃, and the air reflux ratio is 0~0.3.

[0063] like Figure 1As shown, the liquid air heat exchange medium heat exchange component 30 includes a heat exchanger eleven 300, a heat exchanger twelve 301 and a heat exchanger thirteen 302, and the air heat source heat exchange component 31 includes a heat exchanger fourteen 310 and a heat exchanger fifteen 311; the liquid air tank 23, the heat exchanger eleven 300, the heat exchanger twelve 301, the heat exchanger fourteen 310, the heat exchanger fifteen 311 are connected in sequence with the high-temperature air generator 32 in sequence, and the heat exchanger thirteen 302 is connected between the inlet of the liquid air tank 23 and the heat exchanger twelve 301; at this time, the heat exchanger nine 211, the first heat exchange medium tank 133 and the heat exchanger eleven 300 are connected to form a third circulation heat exchange loop 6; the heat exchanger twelve 301, the heat exchanger seventeen 141 and the third heat exchange medium boosting structure 131 are connected to form a fourth circulation heat exchange loop 7; the heat exchanger fourteen 310 is connected to the low-temperature heat source 150; the heat exchanger fifteen 311 is connected to the high-temperature heat source 151.

[0064] like Figure 1 As shown, a liquid air pump 33 may be provided on the pipeline between the liquid air tank 23 and the heat exchanger eleven 300. At this time, the power generation process of the high-temperature air power generation circuit 3 is as follows: the liquid air from the liquid air tank 23 is pressurized by the liquid air pump 33 and divided into two paths. The first path enters the heat exchanger eleven 300 to exchange heat with the heat exchange medium, and the shallow cold heat exchange medium is generated into a deep cold heat exchange medium. The high-pressure liquid air after heat exchange flows to the heat exchanger twelve 301; the second path enters the heat exchanger thirteen 302 to exchange heat with the heat exchange medium, and then mixes with the high-pressure liquid air of the first path and enters the heat exchanger twelve, the heat exchanger fourteen 310, and the heat exchanger fifteen 311 in turn, and exchanges heat with the heat exchange medium, the low-temperature heat source 150, and the high-temperature heat source 151 respectively, so as to generate high-pressure and high-temperature air from the high-pressure liquid air, and finally enters the high-temperature air generator 32 for expansion and power generation operation. After power generation, the high-temperature and high-pressure air generates normal-pressure air, which can be directly discharged into the atmosphere.

[0065] The first circulating heat exchange loop 4 can be formed by connecting the heat exchanger seven 142, the second heat exchange medium boosting structure 132 and the heat exchanger thirteen 302. In the first circulating heat exchange loop 4, the heat exchange medium from the second heat exchange medium boosting structure 132 enters the heat exchanger thirteen 302 to perform heat exchange operation with liquid air to generate a deep cold low temperature heat exchange medium, and then flows to the heat exchanger seven 142 to exchange heat with the first medium. After the heat exchange, the heat exchange medium enters the second heat exchange medium boosting structure 132 to perform the next circulation operation.

[0066] The first circulating heat exchange loop 4 can not only use the heat exchanger 7 142 to transfer the cold of the low-temperature heat exchange medium to the first medium to cool the first medium, but also make the heat exchange medium that has been heated after heat exchange flow to the heat exchanger 13 302, and then exchange heat with the low-temperature liquid air at the heat exchanger 13 302 to heat the low-temperature liquid air, while the cooled heat exchange medium flows to the heat exchanger 7 142 for circulating heat exchange. It can be seen that this embodiment uses the first circulating heat exchange loop 4 to use the heat exchange medium as a carrier to transport the cold at the liquid air in the high-temperature air power generation loop 3 to the first medium, which can not only make full use of the cold in the high-temperature air power generation loop 3, but also effectively improve the operation safety.

[0067] The heat exchange medium source 13 may further include a fourth heat exchange medium pressurizing structure 134, which is connected between the first heat exchange medium tank 133 and the heat exchanger eleven 300. In the third circulating heat exchange loop 6, the heat exchange medium from the first heat exchange medium tank 133 is pressurized by the fourth heat exchange medium pressurizing structure 134, enters the heat exchanger eleven 300 to perform heat exchange operation with liquid air to generate deep cold low temperature heat exchange medium, and then enters the heat exchanger nine 211 to perform heat exchange with medium pressure air to generate shallow cold heat exchange medium, and then enters the first heat exchange medium tank 133 to perform the next circulation operation.

[0068] The third circulating heat exchange loop 6 can not only transfer the coldness of the heat exchange medium in the first heat exchange medium tank 133 to the liquid air power generation loop 2 for heat exchange through the heat exchanger nine 211, but also use the heat of the heat exchange medium after heat exchange to heat up the low-temperature liquid air at the heat exchanger eleven 300. In this embodiment, the heat exchange medium is used as a carrier to transfer the coldness of the liquid air in the high-temperature air power generation loop 3 to the compressed air in the liquid air power generation loop 2 through the third circulating heat exchange loop 6, which can not only make full use of the coldness in the high-temperature air power generation loop 3, but also effectively improve the operation safety.

[0069] In the fourth circulating heat exchange loop 7, the heat exchange medium from the third heat exchange medium boosting structure 131 enters the heat exchanger twelve 301 after being pressurized to perform heat exchange operation with liquid air to generate a deep cold low temperature heat exchange medium, and then the deep cold low temperature heat exchange medium enters the heat exchanger seventeen 141 to perform heat exchange with the second medium, and the heat exchange medium after heat exchange enters the third heat exchange medium boosting structure 131 to perform the next circulation operation.

[0070] The fourth circulating heat exchange loop 7 can use the heat exchanger 17 141 to transfer the cold of the low-temperature heat exchange medium to the second medium to cool the second medium, and can make the heat exchange medium that has been heated after heat exchange flow to the heat exchanger 12 301, and then exchange heat with the low-temperature liquid air at the heat exchanger 12 301 to heat the low-temperature liquid air, and at the same time, the cooled heat exchange medium flows to the heat exchanger 17 141 for circulating heat exchange. It can be seen that this embodiment uses the fourth circulating heat exchange loop 7 to use the heat exchange medium as a carrier to transport the cold at the liquid air in the high-temperature air power generation loop 3 to the second medium, which can not only make full use of the cold in the high-temperature air power generation loop 3, but also effectively improve the operation safety.

[0071] During the power generation process of the liquid air power generation circuit 2 and the intermediate medium power generation circuit 1, the heat source from the low-temperature heat source 150 is pressurized by the low-temperature heat source pump 152 and divided into two paths. The first path enters the heat exchanger 14 310 and exchanges heat with the high-pressure low-temperature air and then flows to the low-temperature heat source 150; the second path enters the heat exchanger 5 161 and heats the second medium to increase the temperature of the second medium. The heat source after heat exchange is then mixed with the heat source after heat exchange in the first path, and then flows to the low-temperature heat source 150 for the next cycle operation.

[0072] like Figure 1 As shown, the outlet of the high-temperature heat source 151 in the heat source assembly 15 can be connected to a pipeline, which is divided into three branches, one of which is connected to the heat exchanger six 162, and the heat exchanger six 162 is connected to the inlet of the high-temperature heat source 151 through a loop pipeline; another branch is connected to the heat exchanger three 160, and the heat exchanger three 160 is connected to the inlet of the high-temperature heat source 151 through a loop pipeline; the last branch is connected to the heat exchanger fifteen 311, and the heat exchanger fifteen 311 is connected to the inlet of the high-temperature heat source 151 through a loop pipeline.

[0073] in, Figure 1 The two positions marked with B shown in FIG. are both located on the branch between the high-temperature heat source 151 and the heat exchanger 6 162, and the two positions marked with B are connected to each other; the two positions marked with C are both located on the branch between the high-temperature heat source 151 and the heat exchanger 3 160, and the two positions marked with C are connected to each other. Correspondingly, Figure 1 The two positions marked with D are both located on the loop pipeline between the heat exchanger three 160 and the high-temperature heat source 151, and the two positions marked with D are connected to each other.

[0074] Further explanation, the heat source assembly 15 may also include a high-temperature heat source pump 153, and the high-temperature heat source pump 153 is arranged at the inlet of the high-temperature heat source 151. When the compressed air supply assembly 20 includes the air compressor unit heat exchanger 201, in order to fully utilize the high-temperature heat medium, the high-temperature heat source pump 153 and the inlet of the high-temperature heat source 151 can be connected through a pipeline, and the pipeline is connected to the inlet of the air compressor unit heat exchanger 201, and the outlet of the air compressor unit heat exchanger 201 is connected to the high-temperature heat source pump 153 through a loop pipeline. During the power generation process of the liquid air power generation loop 2 and the intermediate medium power generation loop 1, the heat source from the high-temperature heat source 151 is divided into three paths. The first path enters the heat exchanger six 162 to exchange heat with the second medium, and then flows back to the high-temperature heat source pump 153; the second path enters the heat exchanger three 160 to exchange heat with the first medium, and then flows back to the high-temperature heat source pump 153; the third path enters the heat exchanger fifteen 311 to exchange heat with the high-pressure normal temperature compressed air, and then mixes with the heat sources in the above two paths that flow back to the high-temperature heat source pump 153, and finally enters the high-temperature heat source pump 153 for pressurization; the pressurized heat source is divided into two paths again, the first path enters the high-temperature heat source 151 for heat exchange treatment to meet the next cycle operation; the second path enters the air compressor unit heat exchanger 201 to exchange heat with the high-temperature compressed air, and after heat exchange, it is mixed with the heat source at the outlet of the high-temperature heat source 151 to perform the next cycle operation.

[0075] It should be noted that, in order to facilitate the control of the flow direction of energy and heat exchange medium at various locations in the cold energy power generation system to ensure the normal power generation process, corresponding valves or control valves can be set at various pipelines in the cold energy power generation system according to actual needs. For example, valves are set on the two branches at the outlet of the high-temperature heat source pump 153. When the liquid air power generation circuit 2 stops generating electricity, that is, in an intermittent state, the compressed air supply component 20 does not work and cannot provide compressed air. Therefore, the corresponding valves on the above two branches must be closed to prevent the lack of compressed air flow in the pipeline during the heat exchange process, resulting in abnormal pressure.

[0076] It can be seen that in this embodiment, the low-temperature heat source 150 is used to heat the liquid air in the high-temperature air power generation circuit 3 and the second medium in the intermediate medium power generation circuit 1, and the high-temperature heat source 151 is used to heat the liquid air in the high-temperature air power generation circuit 3 and the first medium and the second medium in the intermediate medium power generation circuit 1. This can add multiple temperature levels to the cold energy power generation system, effectively improve the heat source utilization rate and power generation efficiency in the cold energy power generation system, and thus greatly increase the power generation.

[0077] like Figure 1As shown, the liquid air power generation circuit 2 also includes an air rewarmer 25; a first valve 26 is provided on the pipeline between the liquid air generator 22 and the liquid air tank 23, the liquid air tank 23 is connected to the air rewarmer 25, and a second valve 27 is provided on the pipeline between the liquid air tank 23 and the air rewarmer 25, and the second valve 27 is used to open when the first valve 26 is closed.

[0078] When the first valve 26 is closed, Figure 1 As shown, at this time, the liquid air power generation circuit 2 is in a state of stopping power generation. Since liquid air is stored in the liquid air tank 23 at this time, and there is still low-temperature and low-pressure gaseous air flashed out in the liquid air tank 23. At this time, in order to ensure the pressure in the liquid air tank 23, the second valve 27 can be opened to make the pipeline between the liquid air tank 23 and the air reheater 25 conductive, so that the low-temperature and low-pressure gaseous air flashed out can flow to the air reheater, and then the low-temperature and low-pressure gaseous air is heated by the air reheater 25, so that the exhaust at the outlet of the air reheater can meet the emission requirements.

[0079] Further explanation, such as Figure 1 As shown, the air rewarmer 25 is connected between the inlet and outlet of the low-temperature heat source 150, and a third valve 28 is provided on the pipeline between the air rewarmer 25 and the inlet of the low-temperature heat source 150, and the third valve 28 is used to open when the first valve 26 is closed.

[0080] When the third valve 28 is opened, the low-temperature heat source 150 can be used to supply heat to the air resetter to heat the low-temperature and low-pressure gaseous air, further improving the utilization rate of the heat source.

[0081] like Figure 1 As shown, a fourth valve 18 is provided on the pipeline between the first medium source 110 and the second heat exchanger 140, and the fourth valve 18 is used to close when the first valve 26 is closed; the intermediate medium heat source heat exchange component 16 also includes a heat exchanger 163, which is located on the pipeline branch between the first medium source 110 and the fourth valve 18, and the pipeline between the second heat exchanger 140 and the third heat exchanger 160 is connected with the heat exchanger 163, and the heat exchanger 163 is connected between the inlet and the outlet of the low-temperature heat source 150; the pipeline between the first medium source 110 and the fourth valve 18 is connected with the heat exchanger 163 and is provided with a fifth valve 19, and a sixth valve 190 is provided on the pipeline between the outlet of the low-temperature heat source 150 and the heat exchanger 163, and the fifth valve 19 and the sixth valve 190 are used to open when the first valve 26 is closed.

[0082] When the intermediate medium power generation loop 1 uses the first medium to generate electricity during the power generation process, the first medium and the heat exchange medium are first exchanged with heat by using the second heat exchanger 140 in the second circulating heat exchange loop 5, and then the heat exchange medium and the compressed air are exchanged with heat by using the eighth heat exchanger 210 in the liquid air power generation loop 2, that is, when the first medium is used to generate electricity, it is necessary to exchange heat indirectly with the compressed air. Therefore, when the liquid air power generation loop 2 is in a state of stopping power generation, it is impossible to provide compressed air heat to the second circulating heat exchange loop 5. At this time, in order to ensure the safety of the cold energy power generation system, the fourth valve 18 can be closed to stop the heat exchange process of the second circulating heat exchange loop 5, that is, the fourth valve 18 is closed when the liquid air power generation loop 2 is in a state of stopping power generation, so that the second circulating heat exchange loop 5 does not participate in the power generation process.

[0083] When the fourth valve 18 is closed, it is still necessary to ensure that the intermediate medium power generation circuit 1 can generate electricity normally. Therefore, the intermediate medium heat source heat exchange component 16 in this embodiment also includes a heat exchanger 163. When the fifth valve 19 and the sixth valve 190 are both opened, Figure 1 As shown, the first medium from the first medium source 110 is pressurized by the first medium pump 1100, and then enters the heat exchanger 163 and the heat exchanger 160 in sequence, and exchanges heat with the low-temperature heat source 150 and the high-temperature heat source 151 respectively to generate a high-temperature first medium, and then enters the first generator 170 to expand and generate electricity. The low-temperature heat source 150 and the high-temperature heat source 151 exchange heat in sequence, which can effectively increase the temperature of the first medium, thereby greatly increasing the power generation. After the high-temperature first medium expands and generates electricity, a low-pressure, low-temperature gaseous first medium is generated. The low-pressure, low-temperature gaseous first medium then enters the distributor 1700 and is divided into two paths. The first path enters the heat exchanger 120 to exchange heat with the low-pressure LNG, and the low-pressure, low-temperature gaseous first medium generates a low-temperature liquid first medium and flows to the first medium source 110; the second path enters the heat exchanger 7 142 to exchange heat with the heat exchange medium, and the low-pressure, low-temperature gaseous first medium generates a low-temperature liquid first medium. The low-temperature liquid first medium is mixed with the low-temperature liquid first medium in the first path and flows to the first medium source 110 for the next cycle operation.

[0084] Since the process of using the second medium to generate electricity during the power generation process of the intermediate medium power generation circuit 1 does not require direct or indirect heat exchange with the compressed air, when the liquid air power generation circuit 2 is in a state of stopping power generation, the process of using the second medium to generate electricity is consistent with the power generation process in the aforementioned second medium power generation path, and will not be repeated here.

[0085] In addition, since the process of low-pressure LNG exchanging heat with heat exchanger 1 120 and heat exchanger 4 121 in sequence does not require the participation of compressed air, when the liquid air power generation circuit 2 is in a state of stopping power generation, the low-pressure LNG from the low-pressure LNG source 10 still passes through heat exchanger 1 120 and heat exchanger 4 121 in sequence to exchange heat with the first medium and the second medium respectively, and then becomes low-pressure NG and is discharged.

[0086] like Figure 1 As shown, a seventh valve 8 is provided on the pipeline between the heat exchanger eleven 300 and the heat exchanger nine 211, and the seventh valve 8 is used to close when the first valve 26 is closed; the heat exchange medium source 13 also includes a second heat exchange medium tank 135, and the pipeline between the heat exchanger eleven 300 and the seventh valve 8 is connected to the second heat exchange medium tank 135, and an eighth valve 9 is provided on the pipeline between the heat exchanger eleven 300 and the second heat exchange medium tank 135, and the eighth valve 9 is used to open when the first valve 26 is closed.

[0087] Since the third circulating heat exchange loop 6 first uses the heat exchanger nine 211 to exchange heat between the medium-pressure compressed air and the heat exchange medium, and then uses the heat exchanger eleven 300 to exchange heat between the heat exchange medium and the liquid air in the high-temperature air power generation loop 3, that is, the third circulating heat exchange loop 6 uses the heat exchange medium as a carrier to indirectly exchange heat between the compressed air and the liquid air. At this time, the compressed air participates in the heat exchange process, so when the liquid air power generation loop 2 is in a state of stopping power generation, it is impossible to provide compressed air heat to the third circulating heat exchange loop 6. At this time, in order to ensure the safety of the cold energy power generation system, the seventh valve 8 can be closed to isolate the heat exchanger nine 211, so that the heat exchanger nine 211 does not participate in the circulating heat exchange process of the third circulating heat exchange loop 6.

[0088] When the seventh valve 8 is closed, in order to ensure that the high-temperature air power generation circuit 3 can normally exchange heat and generate electricity, the heat exchange medium source 13 in this embodiment also includes a second heat exchange medium tank 135. When the eighth valve 9 is opened, Figure 1 As shown, the heat exchange medium from the first heat exchange medium tank 133 is pressurized by the fourth heat exchange medium pressurizing structure 134, enters the heat exchanger 11 300 to perform heat exchange operation with liquid air to generate deep cold low temperature heat exchange medium, and then enters the second heat exchange medium tank 135 through the eighth valve 9 to store cold energy for the next step of cold energy utilization. At this time, the high temperature air power generation circuit 3 can still exchange heat with liquid air at the heat exchanger 11 300 through the heat exchange medium at the first heat exchange medium tank 133, which will not affect the heat exchange process at the heat exchanger 11 300, so the high temperature air power generation circuit 3 can generate electricity normally, and the power generation process in the high temperature air power generation circuit 3 is as described above, which will not be repeated here.

[0089] In addition, since the circulation heat exchange process of the first circulation heat exchange loop 4 between the first medium power generation pathway and the high-temperature air power generation loop 3, and the circulation heat exchange process of the fourth circulation heat exchange loop 7 in the second medium power generation pathway and the high-temperature air power generation loop 3, do not require the participation of compressed air, when the liquid air power generation loop 2 is in a state of stopping power generation, the specific circulation heat exchange process of the first circulation heat exchange loop 4 and the specific circulation heat exchange process of the fourth circulation heat exchange loop 7 are also as described above, and will not be repeated here.

[0090] It should be noted that since the liquid air power generation circuit 2 is in a state of stopping power generation, the intermediate medium power generation circuit 1 and the high-temperature air power generation circuit 3 can continue to generate electricity at different time periods, and at this time, the intermediate medium power generation circuit 1 and the high-temperature air power generation circuit 3 both use the low-temperature heat source 150 and the high-temperature heat source 151 to generate electricity.

[0091] Based on this, the outlet of the low-temperature heat source 150 is connected to the inlet of the heat exchanger 163 through a branch pipe, and the outlet of the heat exchanger 163 is connected to the inlet of the low-temperature heat source 150 through a loop pipe. Figure 1 As shown, Figure 1 The two positions marked with E in the figure are both located on the branch pipeline between the outlet of the low-temperature heat source 150 and the inlet of the heat exchanger 163, and the two positions marked with E are connected to each other; Figure 1 The two positions marked as F are both located on the loop pipeline between the outlet of heat exchanger 163 and the inlet of low-temperature heat source 150, and the two positions marked as F are connected to each other. At this time, the heat source from low-temperature heat source 150 is divided into four paths after being pressurized by low-temperature heat source pump 152. The first path enters heat exchanger 14 310 and exchanges heat with high-pressure low-temperature air and then flows to low-temperature heat source 150; the second path enters heat exchanger 5 161 and exchanges heat with the second medium and then flows to low-temperature heat source 150; the third path enters air rewarmer 25 and exchanges heat with gaseous air and then flows to low-temperature heat source 150; the fourth path enters heat exchanger 163 and exchanges heat with low-temperature heat source 150, and then mixes with the heat sources after heat exchange of the first and second paths and enters low-temperature heat source 150 to perform the next cycle operation.

[0092] The outlet of the high temperature heat source 151 is connected to the inlet of the heat exchanger 3 160 through a branch pipe, and the outlet of the heat exchanger 3 160 is connected to the inlet of the high temperature heat source 151 through a loop pipe. Figure 1 As shown, Figure 1 The two positions marked with C are both located on the branch pipeline between the outlet of the high-temperature heat source 151 and the inlet of the heat exchanger 3 160, and the two positions marked with C are connected to each other; Figure 1The two positions marked as D are both located on the loop pipeline between the outlet of heat exchanger three 160 and the inlet of high-temperature heat source 151, and the two positions marked as D are connected to each other. At this time, the heat source from high-temperature heat source 151 is pressurized by high-temperature heat source pump 153 and divided into three paths. The first path enters heat exchanger six 162 and exchanges heat with high-pressure low-temperature air and then flows to high-temperature heat source 151; the second path enters heat exchanger three 160 and exchanges heat with the first medium and then flows to high-temperature heat source 151; the third path enters heat exchanger fifteen 311 and exchanges heat with high-temperature heat source 151, and then mixes with the heat source after heat exchange of the first and second paths and enters high-temperature heat source 151 for the next cycle operation.

[0093] It should be noted that in the existing cold energy power generation process, there is still a phenomenon that the shallow cold is directly treated with the low-temperature heat source 150 for heat exchange, resulting in the shallow cold not being fully utilized and the loss of cold energy. The cold energy power generation system provided in this embodiment can achieve the purpose of fully utilizing cold energy by using the cold energy characteristics of low-pressure LNG, liquid air, the first medium, the second medium and the heat exchange medium according to the physical properties of different media and taking corresponding cold energy utilization processes by utilizing cold amounts at different temperatures. In addition, the cold energy power generation system provided in this embodiment can adopt a stepped heat exchange process according to the heat conditions of the high-temperature heat source 151 and the low-temperature heat source 150 in the heat source assembly 15, thereby increasing the temperature of the first medium, the second medium, the liquid air and other power generation media, thereby effectively increasing the power generation and improving the power generation efficiency, so that the power generation efficiency is not less than 80%, effectively solving the problem of low power generation in the existing cold energy power generation process. At the same time, the cold energy power generation system provided in this embodiment can also utilize the cold energy of low-pressure LNG at different temperature levels in the intermediate medium power generation circuit 1 to exchange heat with different media (first medium, second medium), thereby realizing the step-by-step utilization process of LNG cold energy and achieving the purpose of full utilization of cold energy, which also helps to increase power generation and improve power generation efficiency.

[0094] This embodiment also provides a cold energy power generation process, which applies the above-mentioned cold energy power generation system, including: using the intermediate medium power generation circuit 1 and the high-temperature air power generation circuit 3 to continuously generate electricity at different time periods, and using the liquid air power generation circuit 2 to continuously and intermittently generate electricity. Since the cold energy power generation process provided by this embodiment applies the above-mentioned cold energy power generation system, the cold energy power generation process and the above-mentioned cold energy power generation system can solve the same technical problems and achieve the same technical effects, which will not be described in detail here.

[0095] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A cold energy power generation system, characterized in that: It comprises an intermediate medium power generation circuit (1), a liquid air power generation circuit (2) and a high-temperature air power generation circuit (3); The intermediate medium power generation circuit (1) comprises a low-pressure LNG source (10), an intermediate medium source (11), an LNG intermediate medium heat exchange component (12), a heat exchange medium source (13), an intermediate medium heat exchange medium heat exchange component (14), a heat source component (15), an intermediate medium heat source heat exchange component (16) and an intermediate medium generator component (17); The low-pressure LNG source (10), the LNG intermediate medium heat exchange component (12), the intermediate medium source (11), the intermediate medium heat exchange component (14), the intermediate medium heat source heat exchange component (16), and the intermediate medium generator component (17) are connected in sequence, and the intermediate medium generator component (17) is connected to the LNG intermediate medium heat exchange component (12) to form the intermediate medium power generation circuit (1); The LNG intermediate medium heat exchange component (12) is used to exchange heat between the low-pressure LNG and the intermediate medium so as to cool the intermediate medium to form a low-temperature liquid intermediate medium; the intermediate medium heat exchange component (14) is connected to the heat exchange medium source (13) and is used to exchange heat between the low-temperature liquid intermediate medium and the heat exchange medium so as to initially heat the low-temperature liquid intermediate medium; the intermediate medium heat source heat exchange component (16) is connected to the heat source component (15) and is used to exchange heat between the intermediate medium and the heat source so as to reheat the intermediate medium that has been initially heated; the intermediate medium generator component (17) is used to receive the high-temperature intermediate medium that has been heated again and expand it to generate electricity; The liquid air power generation circuit (2) comprises a compressed air supply component (20), an air heat exchange medium heat exchange component (21), a heat exchanger 10 (24), a liquid air generator (22) and a liquid air tank (23); The compressed air supply assembly (20), the air heat exchange medium heat exchange assembly (21), the liquid air generator (22), the heat exchanger ten (24) and the liquid air tank (23) are connected in sequence, and the liquid air tank (23) is connected to the compressed air supply assembly (20) to form the liquid air power generation circuit (2); The air heat exchange medium heat exchange component (21) is in communication with the intermediate medium heat exchange medium heat exchange component (14) and is used for exchanging heat between the compressed air and the heat exchange medium, so as to cool the compressed air to form low-temperature air; the liquid air generator (22) is used for receiving low-temperature liquid air and performing decompression to generate electricity; the liquid air tank (23) is used for receiving and storing the low-temperature liquid air after the liquid air generator (22) generates electricity; The high-temperature air power generation circuit (3) comprises a liquid air heat exchange medium heat exchange component (30), an air heat source heat exchange component (31), a high-temperature air generator (32) and a liquid air pump (33); The liquid air tank (23), the liquid air pump (33), the liquid air heat exchange medium heat exchange component (30), the air heat source heat exchange component (31), and the high-temperature air generator (32) are sequentially connected to form the high-temperature air power generation circuit (3); The liquid air heat exchange medium heat exchange component (30) is connected to the heat exchange medium source (13) and is used for exchanging heat between the heat exchange medium and the low-temperature liquid air from the liquid air tank (23) so as to increase the temperature of the liquid air and reduce the temperature of the heat exchange medium; the air heat source heat exchange component (31) is connected to the heat source component (15) and is used for exchanging heat between the low-temperature gaseous air and the heat source so as to increase the temperature of the low-temperature gaseous air and convert it into high-temperature gaseous air; the high-temperature air generator (32) is used for receiving the high-temperature gaseous air and expanding it to generate electricity.

2. The cold energy power generation system according to claim 1, characterized in that: The intermediate medium source (11) comprises a first medium source (110), the LNG intermediate medium heat exchange assembly (12) comprises a first heat exchanger (120), the heat exchange medium source (13) comprises a first heat exchange medium pressurizing structure (130), the intermediate medium heat exchange assembly (14) comprises a second heat exchanger (140), the heat source assembly (15) comprises a low-temperature heat source (150) and a high-temperature heat source (151), the intermediate medium heat source heat exchange assembly (16) comprises a third heat exchanger (160), and the intermediate medium generator assembly (17) comprises a first generator (170); The low-pressure LNG source (10), the heat exchanger 1 (120), the first medium source (110), the heat exchanger 2 (140), the heat exchanger 3 (160) and the first generator (170) are connected in sequence, and the first generator (170) is connected to the heat exchanger 1 (120); the heat exchanger 1 (120) is used for exchanging heat between the low-pressure LNG source (10) and the first medium, so that the gaseous first medium forms a low-temperature liquid first medium; the heat exchanger 2 (140) is connected to the first heat exchange medium pressurizing structure (130), and is used for exchanging heat between the low-temperature liquid first medium and the heat exchange medium, so that the low-temperature liquid first medium is initially heated to become the gaseous first medium; the heat exchanger 3 (160) is connected to the high-temperature heat source (151), and is used for exchanging heat between the gaseous first medium and the high-temperature heat source (151), so that the gaseous first medium is heated to become the high-temperature gaseous first medium; the first generator (170) is used for receiving the high-temperature gaseous first medium and expanding it to generate electricity; The intermediate medium source (11) further comprises a second medium source (111), the LNG intermediate medium heat exchange assembly (12) further comprises a heat exchanger four (121), the heat exchange medium source (13) further comprises a third heat exchange medium pressurizing structure (131), the intermediate medium heat exchange medium heat exchange assembly (14) comprises a heat exchanger seventeen (141), the intermediate medium heat source heat exchange assembly (16) further comprises a heat exchanger five (161) and a heat exchanger six (162), and the intermediate medium generator assembly (17) further comprises a second generator (171); The low-pressure LNG source (10), heat exchanger four (121), heat exchanger seventeen (141), second medium source (111), heat exchanger five (161), heat exchanger six (162) and second generator (171) are connected in sequence, and the second generator (171) is connected to heat exchanger four (121); the heat exchanger four (121) is used for heat exchange between the low-pressure LNG source (10) and the second medium, so that the second medium is initially cooled to form a low-temperature liquid second medium; the heat exchanger seventeen (141) is connected to the third heat exchange medium pressurizing structure (131) for The low-temperature liquid second medium and the heat exchange medium are cold exchanged to cool the low-temperature liquid second medium again; the heat exchanger five (161) is connected to the low-temperature heat source (150) and is used to exchange heat between the low-temperature liquid second medium and the low-temperature heat source (150) to initially heat the low-temperature liquid second medium to a room-temperature second medium; the heat exchanger six (162) is connected to the high-temperature heat source (151) and is used to exchange heat between the room-temperature second medium and the high-temperature heat source (151) to heat the room-temperature second medium to a high-temperature second medium; the second generator (171) is used to receive the high-temperature second medium and expand it to generate electricity.

3. The cold energy power generation system according to claim 2, characterized in that: The intermediate medium heat exchange medium heat exchange component (14) further includes a heat exchanger seven (142), the heat exchange medium source (13) further includes a second heat exchange medium pressurizing structure (132), a branch pipeline is provided between the first generator (170) and the first medium source (110), the heat exchanger seven (142) is provided on the branch pipeline, and the heat exchanger seven (142), the second heat exchange medium pressurizing structure (132) and the liquid air heat exchange medium heat exchange component (30) are connected to form a first circulating heat exchange loop (4); The heat exchanger seven (142) is used for exchanging heat between the heat exchange medium and the low-temperature gaseous first medium from the first generator (170), so as to cool the low-temperature gaseous first medium to form a low-temperature liquid first medium.

4. The cold energy power generation system according to claim 2 or 3, characterized in that: The air heat exchange medium heat exchange component (21) comprises a heat exchanger eight (210) and a heat exchanger nine (211); The compressed air supply assembly (20), heat exchanger eight (210), heat exchanger nine (211), heat exchanger ten (24) and the liquid air generator (22) are connected in sequence, and the heat exchanger eight (210), heat exchanger two (140) and the first heat exchange medium boosting structure (130) are connected to form a second circulating heat exchange loop (5); The heat exchange medium source (13) further comprises a first heat exchange medium tank (133), and the heat exchanger nine (211), the first heat exchange medium tank (133) and the liquid air heat exchange medium heat exchange component (30) are connected to form a third circulating heat exchange loop (6); The compressed air supply assembly (20) and the liquid air tank (23) are both connected to the heat exchanger ten (24), and the heat exchanger ten (24) is used to exchange heat between the low-temperature liquid air that has undergone heat exchange in the heat exchanger nine (211) and the low-temperature gaseous air from the liquid air tank (23), so as to further cool the low-temperature liquid air.

5. The cold energy power generation system according to claim 4, characterized in that: The liquid air heat exchange medium heat exchange component (30) comprises a heat exchanger eleven (300), a heat exchanger twelve (301) and a heat exchanger thirteen (302); the air heat source heat exchange component (31) comprises a heat exchanger fourteen (310) and a heat exchanger fifteen (311); The liquid air tank (23), the heat exchanger 11 (300), the heat exchanger 12 (301), the heat exchanger 14 (310), and the heat exchanger 15 (311) are sequentially connected to the high-temperature air generator (32), and the heat exchanger 13 (302) is connected between the inlet of the liquid air tank (23) and the heat exchanger 12 (301); The heat exchanger nine (211), the first heat exchange medium tank (133) and the heat exchanger eleven (300) are connected to form the third circulating heat exchange loop (6); The heat exchanger 12 (301), the heat exchanger 17 (141) and the third heat exchange medium pressurizing structure (131) are connected to form a fourth circulating heat exchange loop (7); The heat exchanger fourteen (310) is in communication with the low-temperature heat source (150); The heat exchanger fifteen (311) is connected to the high-temperature heat source (151).

6. The cold energy power generation system according to claim 5, characterized in that: The liquid air power generation circuit (2) further comprises an air rewarmer (25); A first valve (26) is provided on the pipeline between the liquid air generator (22) and the liquid air tank (23), the liquid air tank (23) is in communication with the air rewarmer (25), and a second valve (27) is provided on the pipeline between the liquid air tank (23) and the air rewarmer (25), the second valve (27) being used to open when the first valve (26) is closed.

7. The cold energy power generation system according to claim 6, characterized in that: The air rewarmer (25) is connected between the inlet and the outlet of the low-temperature heat source (150), and a third valve (28) is provided on the pipeline between the air rewarmer (25) and the inlet of the low-temperature heat source (150), and the third valve (28) is used to open when the first valve (26) is closed.

8. The cold energy power generation system according to claim 6, characterized in that: A fourth valve (18) is provided on the pipeline between the first medium source (110) and the second heat exchanger (140), and the fourth valve (18) is used to close when the first valve (26) is closed; The intermediate medium heat source heat exchange assembly (16) further comprises a heat exchanger 16 (163); the pipeline between the first medium source (110) and the fourth valve (18) is connected to the pipeline between the second heat exchanger (140) and the third heat exchanger (160) via the heat exchanger 16 (163); and the heat exchanger 16 (163) is connected between the inlet and the outlet of the low-temperature heat source (150); A fifth valve (19) is provided on the pipeline between the first medium source (110) and the fourth valve (18) and the pipeline between the heat exchanger sixteen (163), and a sixth valve (190) is provided on the pipeline between the outlet of the low-temperature heat source (150) and the heat exchanger sixteen (163). The fifth valve (19) and the sixth valve (190) are used to open when the first valve (26) is closed.

9. The cold energy power generation system according to claim 6, characterized in that: A seventh valve (8) is provided on the pipeline between the heat exchanger eleven (300) and the heat exchanger nine (211), and the seventh valve (8) is used to close when the first valve (26) is closed; The heat exchange medium source (13) further includes a second heat exchange medium tank (135), the pipeline between the heat exchanger eleven (300) and the seventh valve (8) is connected to the second heat exchange medium tank (135), and an eighth valve (9) is provided on the pipeline between the heat exchanger eleven (300) and the second heat exchange medium tank (135), and the eighth valve (9) is used to open when the first valve (26) is closed.

10. A cold energy power generation process, using the cold energy power generation system according to any one of claims 1 to 9, characterized in that: include: The intermediate medium power generation circuit (1) and the high-temperature air power generation circuit (3) are used to continuously generate power at different time periods, and the liquid air power generation circuit (2) can generate power continuously and intermittently.

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