Combined cooling, heating and power system based on near-isothermal compressed air energy storage and heat-to-work conversion

Abstract

A combined cooling, heating and power system based on near-isothermal compressed air energy storage and heat-to-work conversion, the system includes: a near-isothermal compressed air system for providing compressed air, whose inlet is the air inlet of the system; a pressure regulating valve, whose inlet is close to the outlet of the isothermal compressed air system, regulating the pressure of the output compressed air; the compressed air enters the expander to perform work and is connected to the generator for power generation; a vortex tube, whose inlet is connected to the outlet of the expander, converts the compressed air after pressure reduction into cold and hot air flows, wherein the cold air flow provides cooling for users, and the hot air flow passes through the heat exchanger to complete heat exchange and enter the pneumatic motor; the pneumatic motor uses the hot air flow after heat exchange as heat to generate electricity and refrigerate. The present invention can improve the energy utilization rate of compressed air energy storage, maximize the energy utilization of the entire system, solve the users' electricity, cooling, heating and water consumption problems, and at the same time reduce fossil fuel consumption and greenhouse gas emissions.

Description

Technical Field

[0001] The present invention belongs to the field of energy technology, and relates to the fields of compressed air energy storage (CAES), vortex tube refrigeration, pneumatic motor refrigeration (PM), and combined cooling, heating and power (CCHP), and in particular to a combined cooling, heating and power system based on near-isothermal compressed air energy storage and heat-to-work conversion. Background Art

[0002] Currently, renewable energy is already in use, and more and more renewable energy sources are connected to the grid for power generation. However, these energy sources are highly intermittent and volatile, which can impact the stability of the power grid. Energy storage technology can largely overcome the above-mentioned shortcomings. Compressed air energy storage (CAES) technology, as a large-scale power storage technology, can achieve "peak shaving and valley filling" of the power grid, and has positive applications in power grid connection, reducing carbon emissions, etc., with great economic benefits. However, in order to improve the working capacity, the current compressed air energy storage system needs to consume external heat to heat the compressed air, and in order to maintain a certain output power, a large amount of fossil fuels needs to be consumed during the energy release stage, which will lead to increased greenhouse gas emissions. In addition, the energy utilization form is relatively single and cannot meet the cooling needs of users. Summary of the Invention

[0003] In order to overcome the shortcomings of the above-mentioned prior art, the purpose of the present invention is to provide a combined heat, cooling and power system based on near-isothermal compressed air energy storage and heat-to-work conversion, so as to improve the energy utilization rate of compressed air energy storage, maximize the energy utilization of the entire system, solve users' electricity, cooling, heating and water consumption problems, and reduce fossil fuel consumption and greenhouse gas emissions.

[0004] In order to achieve the above object, the technical solution adopted by the present invention is:

[0005] A combined cooling, heating and power system based on near-isothermal compressed air energy storage and heat-to-work conversion, comprising a near-isothermal compressed air energy storage system and a heat-to-work conversion system; the near-isothermal compressed air energy storage system performs near-isothermal air compression and recovers heat; the heat-to-work conversion system comprises an expander, a generator, a vortex tube, a second heat exchanger and a pneumatic motor;

[0006] The expander and the generator use the compressed air obtained from the near-isothermal compressed air energy storage system to generate electricity; the inlet of the vortex tube is connected to the outlet of the expander, and the compressed air after the expander does work is converted into cold and hot air flows, wherein the cold air flow provides cooling for the user, and the hot air flows into the inlet on the heat source side of the second heat exchanger, and the hot air flow at the outlet on the heat source side of the second heat exchanger enters the pneumatic motor to expand and do work, thereby achieving power generation and refrigeration.

[0007] In one embodiment, a pressure regulating valve is provided at the inlet of the expander.

[0008] In one embodiment, the near-isothermal compressed air energy storage system includes an air compressor, a first heat exchanger, a water-gas coexistence tank and a low-pressure water tank. The air inlet of the water-gas coexistence tank is provided with an air inlet valve, the air outlet is provided with an exhaust valve, and the water inlet is provided with a second valve. The water inlet of the water-gas coexistence tank is connected to the low-pressure water tank; the air compressor compresses the ambient air to a set pressure, the first heat exchanger recovers the heat in the compression process, and the compressed air and low-pressure water after heat exchange realize a near-isothermal air compression process in the water-gas coexistence tank.

[0009] In one embodiment, a buffer tank is provided on the air inlet pipeline of the water-gas coexistence tank between the first heat exchanger and the air inlet valve, an air storage chamber is provided on the air outlet pipeline of the water-gas coexistence tank between the expander and the exhaust valve, a water feed pump and a third valve are provided on the water inlet pipeline of the water-gas coexistence tank, and the second valve and the third valve are respectively located on both sides of the water feed pump.

[0010] In one embodiment, the air inlet valve is opened, the exhaust valve and the second valve are closed, and the air in the buffer tank enters the water-gas coexistence tank. When the air entering the water-gas coexistence tank reaches a set volume, the air inlet valve is closed; the second valve is opened, the third valve is opened, the water pump starts working, and water continuously enters the water-gas coexistence tank to compress the air in the water-gas coexistence tank; when the air reaches a set pressure, the second valve is closed, the exhaust valve is opened, and the compressed air in the water-gas coexistence tank is sent to the air storage chamber for storage.

[0011] In one embodiment, a gas flow meter is provided on the air inlet pipe of the water-gas coexistence tank, and a pressure sensor is provided in the tank. The gas flow meter, pressure sensor, air inlet valve, exhaust valve, second valve, water supply pump and third valve are linked, and the starting pressure of the exhaust valve can be adjusted between 2.4-4.0 MPa.

[0012] In one embodiment, the heat source side inlet of the first heat exchanger is connected to the air outlet of the air compressor, the heat source side outlet is connected to the air inlet of the water-gas coexistence tank, the cold source side inlet is connected to cold water, and the cold source side outlet is connected to the water inlet of the water storage tank. A first valve is provided at the water inlet of the water storage tank. When the air compressor is running, the first valve is opened, and the cold source side outlet of the first heat exchanger is medium-temperature water, which enters the water storage tank through the first valve for storage.

[0013] In one embodiment, the cold source side inlet of the second heat exchanger is connected to the water outlet of the water storage tank, and the cold source side outlet is connected to the heat user to provide hot water to the user. The water outlet of the water storage tank is provided with a second valve.

[0014] The present invention also provides a combined heating, cooling and power method using the combined heating, cooling and power system based on near-isothermal compressed air energy storage and heat-to-work conversion, comprising the following steps:

[0015] Compressing air using a near-isothermal compressed air energy storage system to obtain compressed air;

[0016] The compressed air is adjusted to a desired pressure and then fed into an expander;

[0017] The compressed air does work in the expander, driving the generator to generate electricity. The compressed air after doing work is passed into the vortex tube;

[0018] The compressed air introduced into the vortex tube is divided into two streams: a cold air flow and a hot air flow. The cold air flow provides cooling for users, while the hot air flow enters the second heat exchanger to heat the medium-temperature water, and then enters the pneumatic motor to expand and perform work, thereby achieving power generation and cooling.

[0019] In one embodiment, the near-isothermal compressed air energy storage system includes an air compressor, a first heat exchanger, a water-gas coexistence tank, and a low-pressure water tank. During the air compression process, the cold side inlet of the first heat exchanger is connected to cold water, and the cold source side outlet of the first heat exchanger is connected to the water storage tank inlet. The heat released by the high-temperature compressed air in the interstage cooler is absorbed by the cold water introduced; after being preheated in the first heat exchanger, the cold water enters the water storage tank, passes through the second heat exchanger, and is reheated by the hot air flow at the vortex tube outlet, and then sent to the heat user for heating.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] 1. While the air is being used to generate electricity in the pneumatic motor, the outlet gas still has the characteristic of refrigeration potential. The hot air flow from the vortex tube after heat exchange is passed into it, which can achieve the purpose of power generation and refrigeration at the same time.

[0022] 2. The vortex tube can generate vortexes in high-speed airflow to separate cold and hot airflows. The hot airflow is used to provide heat to the medium-temperature water and the pneumatic motor, and the cold airflow is used for cooling. The medium-temperature water is heated and sent to the heat user, and the pneumatic motor's expansion characteristics are used to generate electricity. The outlet gas is used for cooling and merged with the vortex tube's cold airflow into one place and sent to the cold user to achieve combined cooling, heating and power.

[0023] 3. In the process of compressing air, the present invention can reuse the heat released during the air compression through the interstage cooler.

[0024] 4. The present invention simultaneously utilizes the heat in the hot air flow to reheat the medium-temperature water and deliver it to the heat users, thus achieving good economic and environmental benefits while meeting the users' needs for electricity, cooling, heating and water.

[0025] 5. The present invention utilizes the principle of energy cascade utilization to efficiently utilize the hot air flow at the outlet of the vortex tube. The hot air flow provides heat for the pneumatic motor, causing the gas to expand in the expander to generate power, thereby rationally utilizing the heat from each part through each heat exchanger.

[0026] 6. The present invention utilizes the heat released by interstage cooling during the air compression process and the low-grade energy in the system, thereby fully utilizing the energy contained in the compressed air, maximizing the energy utilization of the entire system, and reducing greenhouse gas emissions without the need to use additional fossil fuels. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a structural schematic diagram of the present invention. DETAILED DESCRIPTION

[0028] The embodiments of the present invention are described in detail below with reference to the accompanying drawings and examples.

[0029] like Figure 1 As shown, the present invention is a combined cooling, heating, and power system with near-isothermal compressed air energy storage and heat-to-work conversion, primarily comprising a near-isothermal compressed air energy storage system and a heat-to-work conversion system. The near-isothermal compressed air energy storage system pressurizes the air, achieving near-isothermal air compression, providing compressed air for the entire system and storing energy by recovering heat. Its inlet serves as the air inlet for the entire system. The term "near-isothermal" in this invention refers to the fact that during the compression process, due to the rapid and short heat exchange, the air temperature changes minimally, resulting in a near-isothermal compression process.

[0030] The heat-to-work conversion system of the present invention is used to convert the energy contained in compressed air into cold energy, electric energy and heat energy according to demand, and send it to the corresponding users. It includes an expander 8, a generator 9, a vortex tube 10, a second heat exchanger 11 and an air motor 12. The expander 8 and the generator 9 use the compressed air obtained by the near-isothermal compressed air energy storage system to generate electricity. The inlet of the vortex tube 10 is connected to the outlet of the expander 8, and the compressed air after the expander 8 does work is converted into cold and hot air flows, wherein the cold air flow provides cooling for the user, and the hot air flow enters the inlet on the heat source side of the second heat exchanger 11. The hot air flow at the outlet on the heat source side of the second heat exchanger 11 enters the air motor 12, and the air motor 12 uses the hot air flow as an energy source to expand and do work, thereby achieving power generation and refrigeration. The second heat exchanger 11 can be a single heat exchanger or a cascade of multiple heat exchangers.

[0031] The corresponding combined cooling, heating and power method has the following steps:

[0032] Compressing air using a near-isothermal compressed air energy storage system to obtain compressed air;

[0033] The compressed air is adjusted to the required pressure and then sent to the expander 8;

[0034] The compressed air performs work in the expander 8, driving the generator 9 to generate electricity. The compressed air after the work is passed into the vortex tube 10;

[0035] The compressed air entering the vortex tube 10 is divided into two streams: a cold air flow and a hot air flow. The cold air flow provides cooling for users, and the hot air flow enters the second heat exchanger 11 to heat the medium-temperature water, and then enters the pneumatic motor 12 to expand and perform work, thereby achieving power generation and cooling.

[0036] The above is the main technical route of the present invention. On this basis, details or further optimization instructions are given below.

[0037] 1. Near isothermal compression compressed air system.

[0038] The near-isothermal compressed air energy storage system of the present invention mainly includes an air compressor 1, a first heat exchanger 13, a water-gas coexistence tank 4 and a low-pressure water tank 20.

[0039] Among them, an air inlet valve 3 is provided at the air inlet of the water-gas coexistence tank 4, an exhaust valve 5 is provided at the air outlet, a second valve 17 is provided at the water inlet, and the water inlet of the water-gas coexistence tank 4 is connected to the low-pressure water tank 20; the air compressor 1 compresses the ambient air to a set pressure, and the first heat exchanger 13 recovers the heat in the compression process. The compressed air and low-pressure water after heat exchange realize a nearly isothermal air compression process in the water-gas coexistence tank 4.

[0040] In the present invention, in view of the compression requirement or the heat requirement of the cold water absorption intermediate cooling process, the cold source side inlet of the first heat exchanger 13 is all cold water.

[0041] The air compressor 1 of the present invention can be a single compressor or a plurality of compressors connected in cascade. The first heat exchanger 13 can be a single heat exchanger or a plurality of heat exchangers connected in cascade.

[0042] exist Figure 1 In the illustrated embodiment, single-stage compression and single-stage cooling heat exchange are selected. The inlet of compressor 1 is the system air inlet, and the outlet is connected to the heat source side inlet of the first heat exchanger 13. The cold source side inlet of the first heat exchanger 13 is connected to normal temperature cold water. The cold source side outlet is connected to the inlet of the water storage tank 15 through the first valve 14. The heat source side outlet of the first heat exchanger 13 is connected to the water-gas coexistence tank 4, and the heat source side inlet is connected to the outlet of the air compressor 1.

[0043] For ease of control, a water pump 18 and a third valve 19 are provided on the water inlet pipeline of the water-gas coexistence tank 4. The second valve 17 and the third valve 19 are located on either side of the water pump 18. The heat source side inlet of the first heat exchanger 13 is connected to the air outlet of the air compressor 1, the heat source side outlet is connected to the air inlet of the water-gas coexistence tank 4, the cold source side inlet is connected to cold water, and the cold source side outlet is connected to the water inlet of the water storage tank 15. The water inlet of the water storage tank 15 is provided with a first valve 14. When the air compressor 1 is running, the first valve 14 is opened, and the cold source side outlet of the first heat exchanger 13 is medium-temperature water, which enters the water storage tank 15 for storage through the first valve 14.

[0044] 2. Gas storage chamber 6.

[0045] The air storage chamber 6 is not an important and necessary component, but when it is set, its inlet is connected to the outlet of the water-gas coexistence tank 4, that is, the air storage chamber 6 is set on the outlet pipe of the water-gas coexistence tank 4 between the expander 8 and the exhaust valve 5 for storing compressed air for standby use.

[0046] In some embodiments of the present invention, in order to achieve automatic control, a gas flow meter can be installed in the air intake pipe of the water-gas coexistence tank 4, and a pressure sensor can be installed in the tank. The gas flow meter, pressure sensor, intake valve 3, exhaust valve 5, second valve 17, water supply pump 18 and third valve 19 are linked according to the aforementioned logical control, and the exhaust valve pressure can be adjusted between 2.4-4.0MPa.

[0047] 3. Buffer tank 2.

[0048] The buffer tank 2 is not an essential component, but when it is provided, it is connected to the air inlet pipe of the water-gas coexistence tank 4 between the first heat exchanger 13 and the air inlet valve 3. The buffer tank 2 can regulate the gas pressure and alleviate pressure fluctuations.

[0049] 4. Pressure regulating valve 7.

[0050] The pressure regulating valve 7 is relatively important. It is connected to the inlet of the expander 8 (when the air storage chamber 6 is provided, it is connected to the outlet of the air storage chamber 6). Its main function is to regulate the pressure of the output compressed air.

[0051] 5. Expander 8.

[0052] The expander 8 is relatively important. The compressed air expands in the expander 8 to do work, which is used to drive the generator 9 to generate electricity. The outlet is connected to the inlet of the vortex tube 10.

[0053] 6. Vortex tube 10.

[0054] The vortex tube 10 is relatively important. Its inlet is connected to the outlet of the expander 8, which converts the compressed air into cold and hot air flows. The cold air flow can directly provide cooling for users, and the hot air flows into the heat source side inlet of the second heat exchanger 11 to participate in more heat-work conversion processes.

[0055] In the present invention, the vortex tube 10 may be selected from models such as 50025H, 50030H, 50040H, etc., and the gas consumption may reach 800L / min.

[0056] 7. Pneumatic motor 12.

[0057] The pneumatic motor 12 is an important component of the present invention. When air enters the cavity, it can not only expand to generate electricity, but also the outlet gas temperature is lower than the ambient temperature, so that the outlet gas has refrigeration potential; it uses the hot air flow output by the vortex tube 10 as heat to generate electricity, and the outlet gas provides cooling.

[0058] In the present invention, the pneumatic motor 12 may be selected from models such as 68X-001F15 / IEC90 or 68X-002F15 / IEC100, and the power specification may reach 6kW.

[0059] In a specific configuration of the present invention, the compressed air at the outlet of the expander 8 is fed into the vortex tube 10 and divided into two air flows, cold and hot.

[0060] The hot air flow outlet of the vortex tube 10 is connected to the heat source side inlet of the second heat exchanger 11, the cold source side inlet of the second heat exchanger 11 is connected to the water outlet of the water storage tank 15, and the cold source side outlet is connected to the heat user to provide hot water for the user. The water outlet of the water storage tank 15 is provided with a second valve 16.

[0061] The gas at the heat source side outlet of the second heat exchanger 11 enters the pneumatic motor 12 to perform work and supply power. The expanded gas is combined with the cold air in the vortex tube and the outlet is connected to the cold user to provide it with cold energy.

[0062] In the present invention, the heat exchanger group uses cold water as the heat exchange medium.

[0063] Based on the above system, the workflow of the present invention is as follows:

[0064] First, the incoming air is pressurized by the compressor unit into compressed air, which is then passed into the buffer tank 2. Simultaneously, during the compression process, the heat released by the high-temperature compressed air in the interstage cooler, or first heat exchanger 13, is absorbed by cold water. Then, the inlet valve 3 opens, allowing air from the buffer tank 2 to enter the water-vapor coexistence tank 4. When the set volume is reached, the inlet valve 3 closes, the second valve 17 opens, and water from the low-pressure water tank 20 is pumped into the water-vapor coexistence tank 4 by the water supply pump. As water is continuously pumped in, the air is compressed, and the heat released during compression is absorbed by the water. Due to the large contact area between water and air, the heat generated during compression is rapidly absorbed, achieving near-isothermal compression. When the air is compressed to the set pressure, the second valve 17 closes, the exhaust valve 5 opens, and the air in the water-vapor coexistence tank 4 is sent to the air storage chamber 6 for storage.

[0065] During the air compression process, the cold side inlet of the first heat exchanger 13 is connected to cold water, and the cold source side outlet of the first heat exchanger 13 is connected to the inlet of the water storage tank 15. The heat released by the high-temperature compressed air in the interstage cooler is absorbed by the cold water introduced; after being preheated in the first heat exchanger 13, the cold water enters the water storage tank 15, passes through the second heat exchanger 11, and is reheated by the hot air flow at the outlet of the vortex tube 10, and then is sent to the heat user for heating.

[0066] After compressed air is regulated to the appropriate pressure by pressure-regulating valve 7 in air storage chamber 6, it enters expander 8 to generate power. The outlet gas is then fed into vortex tube 10, where it is separated into a cold airflow and a hot airflow. The temperatures of these two streams can be adjusted by adjusting the valve at the hot air end. The hot airflow is first heated by medium-temperature water from water storage tank 15, turning it into high-temperature hot water for heat users. It then enters pneumatic motor 12 to expand and generate power. Simultaneously, the outlet gas merges with the cold airflow from vortex tube 10 and is delivered to cold users, achieving the goal of combined cooling, heating, and power.

[0067] In the present invention, the compressor 1 and the expander 8 can be coaxial or non-coaxial according to the spatial layout of the entire system; the expander 8 and the generator 9 are axially connected.

[0068] The present invention has control valves at the inlet and between certain pipes in the system, and both are electromagnetic and can be equipped with radio frequency control devices.

[0069] In summary, the present invention utilizes the characteristics of the pneumatic motor to couple the pneumatic motor with a near-isothermal compressed air system and a vortex tube, resulting in a compact structure. The cold air flow outlet of the vortex tube is used for cooling. According to the principle of cascade energy utilization, the energy of the hot air flow outlet of the vortex tube is effectively utilized to provide heat for the pneumatic motor system. The hot air flow first reheats the medium-temperature water to turn it into high-temperature hot water to provide thermal energy for heat users. At the same time, after heat exchange, the hot air flow enters the pneumatic motor and expands to generate electrical energy. The outlet gas can still be used for refrigeration, providing cold energy for cold users and maximizing the energy utilization of the entire system. At the same time, the energy supply form of the system can be adjusted according to actual needs by adjusting the pressure regulating valve, the valve at the hot air end of the vortex tube, the water flow, etc. The system described in the present invention has a very high energy utilization rate, uses compressed air as an energy source, and meets the user's electricity, cold, heat and water needs while reducing carbon emissions. The system configuration can be flexibly changed according to actual needs, and is environmentally friendly and energy-saving and emission-reducing.

[0070] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made to the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A combined cooling, heating and power system based on near-isothermal compressed air energy storage and heat-to-work conversion, characterized in that: It comprises a near-isothermal compressed air energy storage system and a heat-to-work conversion system; the near-isothermal compressed air energy storage system performs near-isothermal air compression and recovers heat; the heat-to-work conversion system comprises an expander (8), a generator (9), a vortex tube (10), a second heat exchanger (11) and a pneumatic motor (12); The expander (8) and the generator (9) generate electricity using the compressed air obtained from the near-isothermal compressed air energy storage system; the inlet of the vortex tube (10) is connected to the outlet of the expander (8), and the compressed air after the expander (8) has done work is converted into cold and hot air flows, wherein the cold air flow provides cooling for the user, and the hot air flow flows into the heat source side inlet of the second heat exchanger (11), and the hot air flow at the heat source side outlet of the second heat exchanger (11) enters the pneumatic motor (12) to expand and do work, thereby achieving power generation and refrigeration; Wherein, an exhaust valve (5) is provided at the air outlet of the near-isothermal compressed air energy storage system, and the pressure range for activating the exhaust valve (5) is set to 2.4 MPa-4.0 MPa.

2. The combined cooling, heating and power system based on near-isothermal compressed air energy storage and heat-to-work conversion according to claim 1 is characterized in that: The inlet of the expander (8) is provided with a pressure regulating valve (7).

3. The combined cooling, heating and power system based on near-isothermal compressed air energy storage and heat-to-work conversion according to claim 1 is characterized in that: The near-isothermal compressed air energy storage system comprises an air compressor (1), a first heat exchanger (13), a water-gas coexistence tank (4) and a low-pressure water tank (20); an air inlet of the water-gas coexistence tank (4) is provided with an air inlet valve (3), an air outlet is provided with an exhaust valve (5), and a water inlet is provided with a second valve (17); the water inlet of the water-gas coexistence tank (4) is connected to the low-pressure water tank (20); the air compressor (1) compresses ambient air to a set pressure, the first heat exchanger (13) recovers heat in the compression process, and the compressed air and low-pressure water after heat exchange realize a near-isothermal air compression process in the water-gas coexistence tank (4).

4. The combined cooling, heating and power system based on near-isothermal compressed air energy storage and heat-to-work conversion according to claim 3 is characterized in that: A buffer tank (2) is provided on the air inlet pipeline of the water-gas coexistence tank (4) between the first heat exchanger (13) and the air inlet valve (3); an air storage chamber (6) is provided on the air outlet pipeline of the water-gas coexistence tank (4) between the expander (8) and the exhaust valve (5); a water supply pump (18) and a third valve (19) are provided on the water inlet pipeline of the water-gas coexistence tank (4); and the second valve (17) and the third valve (19) are respectively located on both sides of the water supply pump (18).

5. The combined cooling, heating and power system based on near-isothermal compressed air energy storage and heat-to-work conversion according to claim 4 is characterized in that: The air inlet valve (3) is opened, the exhaust valve (5) and the second valve (17) are closed, and the air in the buffer tank (2) enters the water-gas coexistence tank (4). When the air entering the water-gas coexistence tank (4) reaches a set volume, the air inlet valve (3) is closed; the second valve (17) is opened, the third valve (19) is opened, the water pump (18) starts to work, and water continuously enters the water-gas coexistence tank (4) to compress the air in the water-gas coexistence tank (4); when the air reaches a set pressure, the second valve (17) is closed, the exhaust valve (5) is opened, and the compressed air in the water-gas coexistence tank (4) is sent to the air storage chamber (6) for storage.

6. The combined cooling, heating and power system based on near-isothermal compressed air energy storage and heat-to-work conversion according to claim 5 is characterized in that: The air inlet pipe of the water-gas coexistence tank (4) is provided with a gas flow meter, and a pressure sensor is provided in the tank. The gas flow meter, the pressure sensor, the air inlet valve (3), the air exhaust valve (5), the second valve (17), the water supply pump (18) and the third valve (19) are linked together.

7. The combined cooling, heating and power system based on near-isothermal compressed air energy storage and heat-to-work conversion according to claim 3 is characterized in that: The heat source side inlet of the first heat exchanger (13) is connected to the air outlet of the air compressor (1), the heat source side outlet is connected to the air inlet of the water-gas coexistence tank (4), the cold source side inlet is connected to cold water, and the cold source side outlet is connected to the water inlet of the water storage tank (15). A first valve (14) is provided at the water inlet of the water storage tank (15). When the air compressor (1) is running, the first valve (14) is opened, and the cold source side outlet of the first heat exchanger (13) is medium-temperature water, which enters the water storage tank (15) through the first valve (14) for storage.

8. The combined cooling, heating and power system based on near-isothermal compressed air energy storage and heat-to-work conversion according to claim 7 is characterized in that: The cold source side inlet of the second heat exchanger (11) is connected to the water outlet of the water storage tank (15), and the cold source side outlet is connected to the hot user to provide hot water to the user. The water outlet of the water storage tank (15) is provided with a second valve (16).

9. A method for combined cooling, heating and power generation using the combined cooling, heating and power generation system based on near-isothermal compressed air energy storage and heat-to-work conversion as described in claim 1, characterized in that: Here are the steps: Compressing air using a near-isothermal compressed air energy storage system to obtain compressed air; The compressed air is adjusted to a desired pressure and then fed into an expander (8); The compressed air performs work in the expander (8), driving the generator (9) to generate electricity, and the compressed air after the work is passed into the vortex tube (10); The compressed air introduced into the vortex tube (10) is divided into two fluids, a cold air flow and a hot air flow. The cold air flow provides cooling for the user, and the hot air flow enters the second heat exchanger (11) to heat the medium-temperature water, and then enters the pneumatic motor (12) to expand and perform work, thereby achieving power generation and cooling.

10. The combined cooling, heating and power method according to claim 9, characterized in that: The near-isothermal compressed air energy storage system comprises an air compressor (1), a first heat exchanger (13), a water-gas coexistence tank (4) and a low-pressure water tank (20). During the air compression process, the cold side inlet of the first heat exchanger (13) is connected to cold water, and the cold source side outlet of the first heat exchanger (13) is connected to the inlet of the water storage tank (15). The heat released by the high-temperature compressed air in the interstage cooler is absorbed by the cold water introduced; after being preheated in the first heat exchanger (13), the cold water enters the water storage tank (15), passes through the second heat exchanger (11), is reheated by the hot air flow at the outlet of the vortex tube (10), and is then sent to the heat user for heating.

Images