Hydraulic balance type isothermal circulation energy storage power generation system
Through the hydraulic balanced isothermal cyclic energy storage power generation system, combined with multiple isothermal technologies, the problem of instability of renewable energy is solved, and the efficient utilization of energy and the continuity of supply is achieved.
Patent Information
- Application Number
- CN202421466759.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-06-25
- Publication Date
- 2025-03-28
- Estimated Expiration
- 2034-06-25
AI Technical Summary
The prior art is difficult to effectively deal with the instability and uncertainty of renewable energy, affecting the continuity and stability of energy supply.
The hydraulic balanced isothermal circulating energy storage power generation system is adopted, combining isothermal compression, isothermal expansion, countercurrent heat exchange and isopressurized energy storage technologies to achieve the organic combination of the energy storage system and the backup energy system.
Ensure the continuity of energy supply by effectively storing and releasing renewable energy sources, balancing energy supply and demand, improving energy utilization efficiency, and providing stable energy support when renewable energy supply is insufficient or interrupted.
Smart Images
Figure CN222686746U_ABST
Abstract
Description
Technical Field
[0001] The utility model belongs to the technical field of energy storage, and particularly relates to a hydraulic balance type isothermal cycle energy storage power generation system. Background Art
[0002] As the global energy structure transforms towards clean and renewable energy, the importance of energy storage + backup systems has become increasingly prominent. With the large-scale deployment of renewable energy such as photovoltaic and wind power, their inherent instability and uncertainty have become increasingly prominent. These problems not only affect the continuity and stability of energy supply, but also pose challenges to the safe operation of the power grid.
[0003] As a key means to solve this problem, the importance of energy storage + backup system is self-evident. First, the energy storage system can effectively store the excess and unstable energy generated by renewable energy and release it when needed, thereby balancing energy supply and demand and improving energy utilization efficiency. Secondly, the backup energy system can provide stable energy support and ensure the continuity of energy supply when the renewable energy supply is insufficient or interrupted. This combination strategy can not only effectively deal with the instability and uncertainty of renewable energy, but also provide strong support for the transformation of energy structure. Summary of the invention
[0004] The utility model provides a hydraulically balanced isothermal cycle energy storage power generation system, which combines four technologies, namely isothermal compression, isothermal expansion, isothermal countercurrent heat exchange and isobaric energy storage, to achieve an organic combination of energy storage system and backup energy system, thus forming a new energy supply mode. This mode can not only cope with the instability and uncertainty of renewable energy, but also flexibly adjust the energy supply strategy according to actual needs, and achieve efficient utilization and optimal configuration of energy.
[0005] The specific description is as follows: A hydraulic balance isothermal cycle energy storage power generation system, including an isothermal compression system, an isothermal expansion system, a countercurrent heat exchanger, a compressed air storage tank, a water reservoir, a hydraulic generator, a booster pump, a control device, a circulating working fluid and connecting pipes therebetween;
[0006] The working fluid inlet of the isothermal compression system is directly connected to the atmosphere, and the working fluid outlet of the isothermal compression system is connected to the compressed air storage tank and the working fluid channel inlet of the countercurrent heat exchanger;
[0007] The hydraulic generator and the booster pump are connected in parallel between the compressed air storage tank and the water reservoir;
[0008] The compressed air storage tank is connected to the working fluid channel inlet of the countercurrent heat exchanger through a pipeline, and the working fluid channel outlet of the countercurrent heat exchanger is connected to the working fluid inlet of the isothermal expansion system; the exhaust gas outlet of the isothermal expansion system is connected to the exhaust gas channel inlet of the countercurrent heat exchanger, and the exhaust gas channel outlet of the countercurrent heat exchanger is connected to the environment.
[0009] Furthermore, the isothermal compression system includes a multi-stage isothermal compressor, a plurality of coolers and a compressed working fluid pipeline therebetween; the multi-stage isothermal compressors are coaxially connected in series; and the cooler is installed on the compressed working fluid pipeline between every two stages of the isothermal compressors.
[0010] Furthermore, the isothermal expansion system includes a multi-stage isothermal expander, a plurality of combustion chambers and a compressed working fluid pipeline; the multi-stage isothermal expanders are coaxially connected in series; the combustion chamber is installed on the expansion working fluid pipeline between every two stages of isothermal expanders or on the working fluid pipeline between the countercurrent heat exchanger and the first-stage isothermal expander.
[0011] Furthermore, the cooler is a water cooling tower or an air-cooled cooler, and the inlet / outlet of the air medium channel of the cooler is respectively connected to the working fluid outlet of the previous stage isothermal compressor / the working fluid inlet of the next stage isothermal compressor.
[0012] Furthermore, the isothermal compressor is of centrifugal or axial flow type and is composed of multiple stages of isothermal compressors connected in series.
[0013] Furthermore, the isothermal expander is of turbine type and is composed of multiple-stage expanders connected in series.
[0014] Furthermore, the fuel in the combustion chamber is coal gas, natural gas, hydrogen, liquid fuel, etc.
[0015] As described above, the power generation system, since the isothermal compressor is divided into multiple stages, and the temperature rise of each stage of compression is limited to a small temperature difference, and after each compression, the temperature of the compressed working fluid is lowered by the cooler, this approximately realizes the "isothermal compression" process; a similar method is used to realize the approximate "isothermal expansion" process of the working fluid during the expansion process. This makes the entire thermal process a process that is closer to the "Carnot cycle", so a relatively high system thermal efficiency can be obtained.
[0016] By adopting a method of multi-stage expansion accompanied by multi-stage heating, the working fluid can be kept at a higher temperature and a higher average temperature throughout the expansion process compared to a single-stage expansion or a few-stage expansion process. According to the Carnot cycle principle, the higher the temperature, the higher the efficiency of the thermal system. Similarly, through multi-stage compression and heat dissipation cooling, the compression process is kept at a lower temperature to achieve an approximate "isothermal compression", which also improves the efficiency of the thermal system. By comparing the maximum efficiency of the theoretical cycle, the efficiency improvement potential of the utility model can be understood.
[0017] The energy utilization rate can be significantly improved by designing a countercurrent heat exchanger to recover the heat of the high-temperature exhaust gas discharged at the end of isothermal expansion and use it for isobaric preheating of compressed air.
[0018] In response to the major challenge of the instability and uncertainty of renewable energy, the utility model adopts an innovative solution through the combination strategy of energy storage and backup energy system; through the energy storage system, it can effectively store the excess and unstable energy generated by renewable energy and accurately release it when needed, so as to balance energy supply and demand and significantly improve energy utilization efficiency. This mechanism enables the entire energy system to operate continuously and stably, no longer subject to fluctuations between power generation and power consumption. The backup energy system can provide stable energy support and ensure the continuity of energy supply in emergency situations where electricity is scarce, when the supply of renewable energy is insufficient or interrupted, and when there is not enough stored energy available.
[0019] This utility model significantly improves the stability and reliability of the power grid in the field of renewable energy power generation, especially photovoltaic and wind power generation, realizes peak shaving and valley filling, load smoothing through energy storage generators, and has rapid response capabilities. Its open cycle design uses air as a working fluid, reduces the requirements for accuracy and cost, and shows significant advantages in efficiency, stability, flexibility and economy, providing an efficient and reliable solution for renewable energy power generation. BRIEF DESCRIPTION OF THE DRAWINGS
[0020] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.
[0021] Attached Figure 1 It is a schematic diagram of the structure and principle of the energy storage and power generation system of the utility model.
[0022] The meanings of the numbers in the above figure are as follows: 1 isothermal compressor; 11 first-stage isothermal compressor; 12 secondary isothermal compressor; 13 third-stage isothermal compressor; 14 fourth-stage isothermal compressor; 15 fifth-stage isothermal compressor; 16 final-stage isothermal compressor; 2 cooler; 21 first-stage cooler; 22 secondary cooler; 23 third-stage cooler; 24 fourth-stage cooler; 25 final-stage cooler; 3 countercurrent heat exchanger; 4 compressed air storage tank; 5 combustion chamber; 51 first-stage combustion chamber; 52 second-stage combustion chamber; 53 third-stage combustion chamber; 54 fourth-stage combustion chamber; 55 fifth-stage combustion chamber; 56 final-stage combustion chamber; 6 isothermal expander; 61 first-stage isothermal expander; 62 second-stage isothermal expander; 63 third-stage isothermal expander; 64 fourth-stage isothermal expander; 65 fifth-stage isothermal expander; 66 final-stage isothermal expander; 7 water reservoir; 201 cooling medium input main pipe; 202 cooling medium output main pipe; 8 control device; 101 first valve; 102 second valve; 103 third valve; 104 fourth valve; 110 hydraulic generator; 120 booster pump. DETAILED DESCRIPTION
[0023] In order to make the purpose, technical solution and advantages of the utility model clearer, the technical solution of the utility model will be described in detail below.
[0024] Obviously, the described embodiments are only some embodiments of the present utility model, rather than all the embodiments.
[0025] Based on the embodiments of the present invention, all other implementations obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention. To make the embodiments easier to understand, the following provides a variety of embodiments or implementation methods to illustrate the relevant devices, modules, and functions of the present invention.
[0026] In order to enable the readers of this embodiment to quickly understand the implementation mode of the utility model, the following is first described. Figure 1 The working principle expressed is explained.
[0027] As attached Figure 1As shown, a hydraulic balance isothermal cycle energy storage power generation system includes: an isothermal compression system, an isothermal expansion system, a countercurrent heat exchanger 3, a compressed air storage tank 4, a water reservoir 7, a hydraulic generator 110, a booster pump 120, a control device 8, a circulating working fluid, and connecting pipes therebetween. The working fluid inlet of the isothermal compression system is directly connected to the environment, and the working fluid outlet of the isothermal compression system is connected to the inlet of the working fluid channel of the compressed air storage tank 4 and the countercurrent heat exchanger 3; the hydraulic generator 110 and the booster pump 120 are connected in parallel between the bottom of the compressed air storage tank 4 and the bottom end of the water reservoir 7. The compressed air storage tank 4 is connected to the working fluid channel inlet of the countercurrent heat exchanger 3 through a pipeline, and the outlet of the working fluid channel of the countercurrent heat exchanger 3 is connected to the working fluid inlet of the isothermal expansion system; the exhaust gas outlet of the isothermal expansion system is connected to the exhaust gas channel inlet of the countercurrent heat exchanger 3.
[0028] The isothermal compression system includes an isothermal compressor 1, multiple coolers 2 and a compressed working fluid pipeline between them; the isothermal compressor 1 is a multi-stage isothermal compressor; the isothermal compressors are coaxially connected in series; the cooler 2 is installed on the compressed working fluid pipeline between every two stages of isothermal compressors, and the inlet / outlet of the air medium channel of the cooler 2 is respectively connected to the working fluid outlet of the previous stage isothermal compressor / the working fluid inlet of the next stage isothermal compressor; the working fluid inlet of the first-stage isothermal compressor 11 is directly connected to the environment, and the outlet of the last-stage isothermal compressor 16 is connected to the inlet of the working fluid channel of the compressed air storage tank 4 and the countercurrent heat exchanger 3.
[0029] The isothermal expansion system includes an isothermal expander 6, multiple combustion chambers 5 and a compressed working fluid pipeline; the isothermal expander 6 is a multi-stage isothermal expander; the isothermal expanders 61~66 are coaxially connected in series; the combustion chamber 5 is installed on the expansion working fluid pipeline between every two stages of isothermal expanders or on the working fluid pipeline between the countercurrent heat exchanger 3 and the first-stage isothermal expander 61, that is, the first-stage combustion chamber 51 is installed on the working fluid pipeline between the working fluid channel of the countercurrent heat exchanger 3 and the first-stage isothermal expander 61; the inlet / outlet of the combustion chambers 52~56 are respectively connected to the working fluid outlet of the previous stage isothermal expander / the working fluid inlet of the next stage isothermal expander; the working fluid outlet of the last-stage isothermal expander 66 is connected to the exhaust gas inlet of the countercurrent heat exchanger 3.
[0030] If the cooler 2 is a water-cooled cooler, the inlet / outlet of the cooling medium channel of the cooler 2 is respectively connected to the outlet / inlet of the cold water source; if the cooler 2 is an air-cooled cooler, the inlet / outlet of the cooling medium channel of the cooler 2 is connected to the atmosphere.
[0031] The circulating working medium is air.
[0032] The function of the isothermal compressor 1 is to inhale working medium air and perform multi-stage isothermal compression on the working medium air to increase the pressure of the working medium.
[0033] The function of the cooler 2 is to dissipate the heat generated by the isothermal compressor 1 to the outside, so that the compression process is maintained at a lower temperature and an approximate "isothermal compression" is achieved.
[0034] The function of the compressed air storage tank 10 is to store / release the compressed air medium which has been isothermally compressed in multiple stages.
[0035] The water outlet of the hydraulic generator 110 is connected to the water tank 7 through a pipeline; the water inlet of the hydraulic generator 110 is connected to the bottom end of the compressed air storage tank 4 through a pipeline; the function of the hydraulic generator 110 is to stabilize the pressure of the compressed air entering the compressed air storage tank 4 and recover part of the energy of the compressed air; in this process, high-pressure compressed air enters the compressed air storage tank 4, and the water in the compressed air storage tank 4 is pressed outward under the action of the high-pressure gas, and the discharged high-pressure water drives the hydraulic generator 110 to operate and generate electricity.
[0036] The function of the booster pump 120 is to inject water into the compressed air storage tank 4 , and the water compresses the air in the compressed air storage tank 4 to enter the countercurrent heat exchanger 3 .
[0037] The function of the countercurrent heat exchanger 3 is to recover the heat of the high-temperature exhaust gas after isothermal expansion, and use the recovered heat to preheat the compressed air before doing work; that is, the high-pressure and low-temperature compressed air exchanges heat with the exhaust gas discharged by the last-stage isothermal expander 66 in the countercurrent heat exchanger 3, and the high-pressure and low-temperature compressed air absorbs the heat of the exhaust gas, is preheated once, and then enters the primary combustion chamber 51.
[0038] The combustion chamber 5 is injected with fuel and mixed with the circulating working medium air entering the combustion chamber and then fully burned to produce tail gas. The fuel in the combustion chamber 5 is coal gas, natural gas, hydrogen, liquid fuel, etc.
[0039] The isothermal expander 6 is connected to the combustion chamber, and is driven by the exhaust gas produced by the combustion chamber 5 to generate power for electricity generation.
[0040] The power generation system of the utility model has three working cycle processes, namely energy storage, power generation and backup energy system working cycle processes.
[0041] When renewable energy (such as solar energy and wind energy) is abundant or electricity consumption is reduced at night, the remaining electricity drives the compressor to compress and store the air, achieving efficient conversion of mechanical energy into compressed air potential energy. Figure 1As shown, the working cycle of energy storage is as follows: the isothermal compressor 1, the hydraulic generator 110, the first valve 101, and the fourth valve 104 are opened, and the isothermal expander 6, the booster pump 120, the second valve 102, and the third valve 103 are closed. In this process, the primary isothermal compressor 11 inhales working medium air from the atmosphere for compression, and the temperature and pressure of the working medium air both rise. In order to prevent the working medium temperature from rising too much, the once-pressurized working medium air of the primary isothermal compressor 11 directly enters the primary cooler 21 for cooling. After cooling, the once-pressurized working medium air enters the secondary isothermal compressor 12 for secondary pressurization, and then enters the secondary cooler 22 for cooling, and in this way, after being compressed to a predetermined pressure in the final isothermal compressor 66, it directly enters the compressed air storage tank 4, and water is discharged from the compressed air storage tank 4 under the action of high-pressure gas to drive the hydraulic generator 110 to operate and generate electricity; the water output through the water outlet of the hydraulic generator 110 finally enters the water storage tank 7, and the energy storage process is completed.
[0042] When the demand for electricity is at a peak or renewable energy supply is insufficient, the compressed air in the compressed air storage tank 4 is released through the pipeline and fully mixed with the fuel in the combustion chamber 5 for combustion, providing sufficient energy for the subsequent power generation process and providing stable and efficient power support. Figure 1 As shown, the power generation working cycle process: the isothermal compressor 1, the first valve 101, and the fourth valve 104 are closed, and the isothermal expander 6, the booster pump 120, the second valve 102, and the third valve 103 are opened. During this process, the booster pump 120 injects water into the compressed air storage tank 4 to compress the air in the compressed air storage tank 4 for reflux (this process increases the compressed air pressure), and the compressed air directly enters the countercurrent heat exchanger 3, and exchanges heat with the high-temperature last tail gas discharged from the last-stage isothermal expander 66 in the countercurrent heat exchanger 3. The compressed air absorbs the heat of the high-temperature last tail gas and then enters the isothermal expansion system; in order to achieve approximate isothermal expansion, the compressed air after absorbing heat enters the combustion chamber 5 before entering the isothermal expander 6 to be mixed with the fuel and fully burned to generate tail gas, and the tail gas drives the isothermal expander 6 to do work; as shown Figure 1As shown, the compressed air after absorbing heat in the countercurrent heat exchanger 3 enters the primary combustion chamber 51, and at the same time, the fuel is injected into the primary combustion chamber 51 and mixed with the compressed air entering the combustion chamber and then fully burned to produce primary tail gas; the primary isothermal expander 61 is connected to the primary combustion chamber 51, and the primary isothermal expander 61 is driven by the entering primary tail gas to generate power and primary tail gas that is cooled and depressurized after doing work; the cooled and depressurized primary tail gas discharged from the primary isothermal expander 61 enters the secondary combustion chamber 52 , mixed with the injected fuel and fully burned again to produce secondary tail gas, and then the secondary tail gas enters the secondary isothermal expander 62, the secondary isothermal expander 62 is driven and generates power and the secondary tail gas with reduced temperature and pressure after doing work; the cooled and depressurized secondary tail gas discharged from the secondary isothermal expander 62 enters the tertiary combustion chamber 53, mixed with the injected fuel and fully burned again to produce tertiary tail gas, and then the tertiary tail gas enters the tertiary isothermal expander 63, the tertiary isothermal expander 63 is driven And generate power and tertiary tail gas that has been cooled and depressurized after doing work; then the tertiary tail gas enters the fourth-stage combustion chamber 54, mixes with the injected fuel and burns fully again to generate quaternary tail gas, then the quaternary tail gas enters the fourth-stage isothermal expander 64, the fourth-stage isothermal expander 64 is driven and generates power and quaternary tail gas that has been cooled and depressurized after doing work; then the quaternary tail gas enters the fifth-stage combustion chamber 55, mixes with the injected fuel and burns fully again to generate quintuple tail gas, then the quintuple tail gas enters the fifth-stage isothermal expander 64 The expander 65, the five-stage isothermal expander 65 is driven to generate power and five tail gases that are cooled and depressurized after doing work; then the five tail gases enter the final combustion chamber 56, mix with the injected fuel and burn fully again to generate six tail gases, then the six tail gases enter the final isothermal expander 66, the final isothermal expander 66 is driven to generate power and the final tail gas that is cooled and depressurized after doing work; the final tail gas is not directly discharged into the air, but directly enters the countercurrent heat exchanger 3 for heat recovery. The temperature of the final tail gas discharged from the countercurrent heat exchanger 3 is close to the ambient temperature, and is directly discharged into the environment, thus completing the power generation work cycle process.
[0043] In an emergency situation where electricity is scarce, if there is no solar energy supply and there is not enough stored energy available, the power system will directly activate the backup energy circulation system. Backup energy system circulation process: isothermal compressor 1, isothermal expander 6, first valve 101 and second valve 102 are opened; hydraulic generator 110, booster pump 120, third valve 103 and fourth valve 104 are closed. During this process, the primary isothermal compressor 11 draws in working air from the environment for compression, and the temperature and pressure of the working air both rise; to prevent the working temperature from rising too much, the once-pressurized working air passing through the primary isothermal compressor 11 directly enters the primary cooler 21 for cooling, and the once-pressurized working air after cooling enters the secondary isothermal compressor 12 for secondary pressurization, and then enters the secondary cooler 22 for cooling, and this continues until the final isothermal compressor 11 is closed. After being compressed to a predetermined pressure in the compressor 66, the compressed air directly enters the countercurrent heat exchanger 3, and the compressed air undergoes isobaric heat exchange with the high-temperature final exhaust gas discharged from the final isothermal expander 66 in the countercurrent heat exchanger 3. The compressed air absorbs the heat of the high-temperature final exhaust gas and then enters the isothermal expansion system. The temperature of the final exhaust gas discharged from the countercurrent heat exchanger 3 is close to the ambient temperature and is directly discharged into the environment. In order to achieve approximate isothermal expansion, the compressed air after absorbing heat first enters the combustion chamber 5 before entering the isothermal expander 6 to be mixed with the fuel for full combustion and produce exhaust gas, and the exhaust gas drives the isothermal expander 6 to generate power. Through the above cycle repeated over and over again, the working cycle of the backup energy system is completed.
[0044] As mentioned above, the main purpose of using multi-stage compression is to avoid the temperature of the compression process from rising too high, because we want to achieve "approximate" isothermal compression. The entire compression process is completed by the isothermal compressor 1.
[0045] In order to achieve approximate isothermal compression, a cooler 2 is used to dissipate the compression heat of each stage of the isothermal compression mechanism into the external atmosphere; for this purpose, a cooler 2 is installed between every two stages of the isothermal compression mechanism to dissipate the compression heat in time.
[0046] As mentioned above, the main purpose of using multi-stage isothermal expansion is to gradually reduce the pressure of the working medium through multi-stage isothermal expansion, avoid large temperature difference and low efficiency in the expansion process, because we want to achieve "approximate" isothermal expansion. The entire expansion process is completed by the isothermal expander 6. In order to achieve approximate isothermal expansion, the working medium air before entering the isothermal expander 6 is first mixed with the fuel in the combustion chamber 5 and fully burned to produce tail gas of constant temperature, which drives each stage of the isothermal expander to do work.
[0047] In order to further improve the implementation case of the utility model, a control scheme for the power generation system equipment of this embodiment is provided here, that is: a set of control devices 8 are provided for the power generation system equipment, and the preferred control device is a DCS system, which can be used to comprehensively control the various components of the power generation system equipment in a hierarchical manner and reduce the mutual influence between the various controller devices. The DCS control system collects the working parameters of each component of the starting equipment, including but not limited to temperature, pressure, flow, stress, displacement, vibration, position, current, voltage, resistance, frequency, and power, and comprehensively controls and protects the operation of each component.
Claims
1. A hydraulically balanced isothermal cycle energy storage power generation system, characterized in that: It includes isothermal compression system, isothermal expansion system, countercurrent heat exchanger, compressed air storage tank, water reservoir, hydraulic generator, booster pump, control device, circulating working fluid and connecting pipes between them; The working fluid inlet of the isothermal compression system is directly connected to the atmosphere, and the working fluid outlet of the isothermal compression system is connected to the compressed air storage tank and the working fluid channel inlet of the countercurrent heat exchanger; The hydraulic generator and the booster pump are connected in parallel between the compressed air storage tank and the water reservoir; The compressed air storage tank is connected to the working fluid channel inlet of the countercurrent heat exchanger through a pipeline, and the working fluid channel outlet of the countercurrent heat exchanger is connected to the working fluid inlet of the isothermal expansion system; the exhaust gas outlet of the isothermal expansion system is connected to the exhaust gas channel inlet of the countercurrent heat exchanger, and the exhaust gas channel outlet of the countercurrent heat exchanger is connected to the environment.
2. A hydraulically balanced isothermal cycle energy storage power generation system as claimed in claim 1, characterized in that: The isothermal compression system comprises a multi-stage isothermal compressor, a plurality of coolers and a compressed working fluid pipeline between them; the multi-stage isothermal compressors are coaxially connected in series; the cooler is installed on the compressed working fluid pipeline between every two stages of isothermal compressors.
3. A hydraulically balanced isothermal cycle energy storage power generation system as claimed in claim 1, characterized in that: The isothermal expansion system includes a multi-stage isothermal expander, a plurality of combustion chambers and a compressed working fluid pipeline; the multi-stage isothermal expanders are coaxially connected in series; the combustion chamber is installed on the expansion working fluid pipeline between every two stages of isothermal expanders or on the working fluid pipeline between the countercurrent heat exchanger and the first-stage isothermal expander.
4. A hydraulically balanced isothermal cycle energy storage power generation system as claimed in claim 2, characterized in that: The cooler is a water cooling tower or an air-cooled cooler, and the inlet / outlet of the air medium channel of the cooler is respectively connected to the working medium outlet of the previous stage isothermal compressor / the working medium inlet of the next stage isothermal compressor.
5. A hydraulically balanced isothermal cycle energy storage power generation system as claimed in claim 2, characterized in that: The isothermal compressor is of centrifugal or axial flow type and is composed of multiple stages of isothermal compressors connected in series coaxially.
6. A hydraulically balanced isothermal cycle energy storage power generation system as claimed in claim 3, characterized in that: The isothermal expander is of turbine type and is composed of multiple stages of expanders connected in series coaxially.
7. A hydraulically balanced isothermal cycle energy storage power generation system as claimed in claim 3, characterized in that: The fuel in the combustion chamber is coal gas, natural gas, hydrogen or liquid fuel.