Method of operating a compressed air energy storage system with inter-stage waste heat recycling

Abstract

The application relates to the new energy technology field, in particular to a running method of a compressed air energy storage system with inter-stage waste heat circulation, wherein the method comprises the following steps: inputting to-be-compressed air into a first-stage compression side structure to perform gas compression, controlling a first steam generator to perform heat exchange treatment on the gas waste heat compressed by the first-stage compression side structure, sequentially performing circulation operation until a last evaporator performs heat exchange on the gas waste heat compressed by a last-stage compression side structure and sends the gas waste heat into a gas cooler to perform cooling and then stores the gas in a gas storage chamber; the gas discharged from the gas storage chamber is reheated by the last-stage steam generator, the reheated gas enters a first-stage turbine side structure to perform turbine power generation, sequentially performs circulation operation until a first evaporator reheats the discharged gas and then the gas enters a last-stage turbine side structure of an expander to perform turbine power generation. Therefore, the problems of low recovery rate and low energy conversion efficiency of the heat exchanger for recovering part of waste heat in the related art are solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of new energy, in particular to a method for operating a compressed air energy storage system with inter-stage waste heat circulation. BACKGROUND

[0002] With the development of energy storage technology, advanced adiabatic compressed air energy storage has been widely concerned by scholars and research institutions at home and abroad due to its long service life, cleanliness and environmental protection. Single-stage compressor has the disadvantages of high outlet gas temperature and large power consumption, so multi-stage compressor is generally used, and the inter-stage compressed gas is cooled. The heat released by the inter-stage cooling of the compressor is low-temperature heat energy, and the discharge amount is also large. If all the heat is taken away by cooling water, energy will be wasted. Therefore, the inter-stage cooling waste heat of the compressor is considered to be recycled to save energy and reduce emissions.

[0003] In the related art, for the recycling of the inter-stage cooling waste heat of the compressor, a heat exchanger is generally used to prepare hot water for the factory or employees. This way recycles the waste heat of the compressor, avoids energy waste, but the recycling rate is low and the conversion energy grade is also low, and the energy conversion efficiency is low. SUMMARY

[0004] The present application provides a method for operating a compressed air energy storage system with inter-stage waste heat circulation to solve the problems of low recycling rate and low energy conversion efficiency in the related art by using a heat exchanger to recycle part of the waste heat.

[0005] The first aspect embodiment of the application provides a method for operating a compressed air energy storage system with inter-stage waste heat circulation, the compressed air energy storage system comprising: a storage chamber, a generator, a plurality of compression-side structures and a plurality of turbine-side structures; each compression-side structure and each turbine-side structure share a steam generator, wherein the steam generator exchanges heat with the gas waste heat of the compression-side structure and the turbine-side structure, and provides heat to the outside, and the last turbine-side structure is connected to the generator; a gas cooler of each compression-side structure is arranged behind the steam generator, wherein the gas cooler is used to cool the gas after heat exchange, the gas cooler is connected to the next compression-side structure, and the gas cooler of the last compression-side structure is connected to the storage chamber, wherein the method comprises the following steps: after the compressed air is input into the first compression-side structure for gas compression, the first steam generator is controlled to exchange heat with the gas waste heat after compression of the first compression-side structure; the gas after heat exchange is input into the second compression machine structure for re-compression work, and then input into the second steam generator, and the operation is sequentially repeated until the last evaporator exchanges heat with the gas waste heat after compression of the last compression-side structure, and then the gas is stored in the gas cooler after cooling and stored in the storage chamber; the gas from the storage chamber is reheated by the last steam generator, the reheated gas enters the first turbine-side structure for turbine power generation, and then the gas discharged from the first turbine-side structure enters the second last steam generator for reheating, and the operation is sequentially repeated until the first evaporator reheats the discharged gas and then inputs the gas into the last turbine-side structure of the expander for turbine power generation.

[0006] Optionally, one end of the first steam generator is connected to the first compression-side structure, the last turbine-side structure and the additional turbine, and the other end is connected to the gas cooler, the last turbine-side structure and the booster pump; one end of the second evaporator is connected to the second compression machine structure, the last turbine-side structure and the additional turbine, and the other end is connected to the gas cooler, the third turbine-side structure and the booster pump; one end of the last evaporator is connected to the last compression-side structure, the first turbine-side structure and the additional turbine, and the other end is connected to the gas cooler, the booster pump and the storage chamber.

[0007] Optionally, one end of the additional turbine is connected to each steam generator, and the other end is connected to the condenser.

[0008] Optionally, the compressed air energy storage system further comprises an additional turbine, wherein one end of the additional turbine is connected to each steam generator, and the other end is connected to the condenser.

[0009] Optionally, the remaining heat energy generated by the gas reheated by each steam generator is used for turbine power generation.

[0010] Optionally, the compressed air energy storage system further comprises a condenser, wherein one end of the condenser is connected to the last stage turbine side structure and the additional turbine, and the other end of the condenser is connected to the booster pump.

[0011] Optionally, the condenser is used to cool the gas discharged from the last stage turbine side structure and the additional turbine.

[0012] Optionally, the compressed air energy storage system further comprises a booster pump, wherein one end of the booster pump is connected to the condenser, and the other end of the booster pump is connected to each steam generator.

[0013] Optionally, the gas discharged from the condenser is re-pressurized and sent back to the steam generator.

[0014] Optionally, the compressed air energy storage system further comprises a heat storage tank and a target reheating device, wherein one end of the heat storage tank is connected to each steam generator, and the other end of the heat storage tank is connected to the target reheating device.

[0015] Optionally, the compressed air energy storage system further comprises a target reheating device, wherein the target reheating device comprises a photothermal heat collector and an electric heating device, the photothermal heat collector is used to collect solar energy to supplement heat to the heat storage tank, and the electric heating device is used to heat the heat storage tank.

[0016] Therefore, the present application has at least the following beneficial effects:

[0017] In the embodiment of the present application, each stage of the compression side structure and each stage of the turbine side structure share the steam generator, the gas waste heat of the compression side structure and the turbine side structure is exchanged, and heat is provided to the outside, the gas cooler of each stage of the compression side structure is arranged behind the steam generator, and is used to cool the gas exchanged from the steam generator, the gas can be cooled to a suitable cooling temperature suitable for entering the inlet of the next stage of compressor, and the temperature of the gas about to enter the next stage of compressor tends to be stable, the traditional multiple heat exchangers are replaced, the waste of energy is avoided, the energy recovery efficiency and the energy conversion efficiency are improved, so that the inter-stage waste heat can be fully utilized for re-compression and expansion power generation with the turbine side structure, in addition, the heat working medium in the heat storage tank can supplement the heat required for reheating the turbine side gas by the steam generator, so as to improve the temperature of the gas entering the inlet of the two-stage turbine of the turbine side, improve the electric-electric conversion efficiency of the system, and further improve the power generation efficiency of the whole system.

[0018] Additional aspects and advantages of the present application will be partially given in the following description, partially will become obvious from the following description, or will be understood by practicing the present application. BRIEF DESCRIPTION OF DRAWINGS

[0019] The above and / or additional aspects and advantages of the present application will become apparent and more readily appreciated from the following description, taken in conjunction with the following drawings of which:

[0020] Figure 1 A block diagram of a compressed air energy storage system with inter-stage waste heat recovery cycle according to an embodiment of the present application;

[0021] Figure 2 A schematic diagram of a method of operating a compressed air energy storage system with inter-stage waste heat recovery cycle according to an embodiment of the present application;

[0022] Figure 3 A detailed flow chart of a steam generator according to an embodiment of the present application.

[0023] Legend of reference signs: gas storage chamber 100, generator 200, compression side structure 300, turbine side structure 400, steam generator 500 and gas cooler 600. DETAILED DESCRIPTION

[0024] Embodiments of the present application are described in detail below with reference to examples thereof illustrated in the attached drawings, in which like or similar elements or components are denoted by the same or similar reference signs throughout the drawings. The embodiments described below are examples and are intended to explain the present application, and should not be understood as limiting the present application.

[0025] A method of operating a compressed air energy storage system with inter-stage waste heat recovery cycle according to an embodiment of the present application is described below with reference to the accompanying drawings. In view of the low recovery rate and low energy conversion efficiency of the partial waste heat recovery using heat exchangers in the related art mentioned above, the present application provides a method of operating a compressed air energy storage system with inter-stage waste heat recovery cycle, in which the steam generator is shared by each compression side structure and each turbine side structure, the gas waste heat of the compression side structure and the turbine side structure is exchanged, and heat is provided externally, the gas cooler of each compression side structure is arranged after the steam generator to cool the exchanged gas, replacing the conventional multiple heat exchangers, avoiding energy waste, improving the energy recovery efficiency and energy conversion efficiency, so that the inter-stage waste heat can be fully utilized for re-compression and expansion power generation with the turbine side structure, improving the power generation efficiency of the entire system. Thus, the problems of low recovery rate and low energy conversion efficiency of the partial waste heat recovery using heat exchangers in the related art are solved.

[0026] Specifically, Figure 1 A block diagram of a compressed air energy storage system with inter-stage waste heat recovery cycle according to an embodiment of the present application.

[0027] As Figure 1As shown, the compressed air energy storage system 10 with inter-stage waste heat recovery cycle includes a gas storage chamber 100, a generator 200, a compression side structure 300, a turbine side structure 400, a steam generator 500 and a gas cooler 600.

[0028] Wherein, the steam generator 500 is shared by each compression side structure 300 and each turbine side structure 400, the steam generator 500 exchanges heat with the gas waste heat of the compression side structure 300 and the turbine side structure 400, and provides heat to the outside, and the last-stage turbine side structure 400 is connected with the generator; the gas cooler of each compression side structure 300 is arranged behind the steam generator 500, wherein the gas cooler 600 is used for cooling the heat-exchanged gas, the gas cooler 600 is connected with the next-stage compression side structure 300, and the gas cooler 600 of the last-stage compression side structure 300 is connected with the gas storage chamber 100.

[0029] Wherein, each compression side structure 300 is a compressor, and each turbine side structure 400 is a turbine.

[0030] It can be understood that, in the embodiment of the application, the steam generator is shared by each compression side structure and each turbine side structure, the steam generator exchanges heat with the gas waste heat of the compression side structure and the turbine side structure, and provides heat to the outside, the gas cooler of each compression side structure is arranged behind the steam generator, is used for cooling the heat-exchanged gas, and cools the gas to a suitable stable temperature suitable for entering the inlet of the next-stage compressor, replaces the traditional multiple heat exchangers, avoids the waste of energy, improves the energy recovery efficiency and the energy conversion efficiency, and thus the inter-stage waste heat can be fully utilized for re-compression and expansion power generation with the turbine side structure, the heat working medium in the heat storage tank can supplement the heat required for reheating the turbine side gas by the steam generator, the temperature of the gas at the inlet of the turbine side turbine can be improved, and thus the power generation efficiency of the whole system is improved.

[0031] Specifically, the steam generator is a relatively key part in the compressed air energy storage system with inter-stage waste heat recovery cycle; the models of the compressor and the turbine are as follows:

[0032]

[0033] W c =C p,a m a (T out -T in )(1.1b)

[0034]

[0035] W t =C p,a m a (Tin -T out )(1.1d)

[0036] wherein, equation (1.1a) is the temperature variation model in the compressor unit, T out is the outlet air temperature; T in is the inlet air temperature; π c is the compression ratio; n is the adiabatic index; equation (1.1b) is the output power model of the compressor, W c is the compressor unit power consumption; C p,a is the air specific heat capacity; m a is the air mass; equation (1.1c) is the outlet temperature model of the turbine, T out is the outlet air temperature; T in is the inlet air temperature; π t is the expansion ratio; equation (1.1d) is the output power model of the turbine, W t is the expander unit output; C p,a is the air specific heat capacity; m a is the air mass; T out is the outlet air temperature; T in is the inlet air temperature.

[0037] The air in the air reservoir exchanges heat with the inner wall of the air reservoir, and the variation relationship of the air temperature and pressure with time is:

[0038] Q = U cv + h out m out - h in m in + W (1.2a)

[0039] wherein, U cv is the variation of the air thermodynamic energy; W is the work exchanged by the air and the environment; h is the convective heat transfer coefficient; m is the air mass.

[0040] The variation relationship of the total energy in the air reservoir is:

[0041] Q S = m in H in - m out H out - hA (T - T w ) (1.2b)

[0042] wherein, Q S is the total energy; H is the air enthalpy; A is the heat transfer area; T is the air temperature; T W is the air reservoir wall temperature.

[0043] The air in the gas storage chamber exchanges heat with the inner wall of the gas storage chamber, and the relationship between the air temperature and the pressure and the change of time is:

[0044]

[0045] In the formula, p is the air density; t is the time; V is the volume of the gas storage chamber; T is the air temperature; T W is the wall temperature of the gas storage chamber.

[0046] In the embodiments of the present application, one end of the first steam generator is connected to the first-stage compression side structure, the last-stage turbine side structure and the additional turbine, and the other end is connected to the gas cooler, the turbine side structure of the last-stage upper stage and the booster pump. One end of the second evaporator is connected to the second-stage compressor structure, the turbine side structure of the last-stage upper stage and the additional turbine, and the other end is connected to the gas cooler, the third-from-last-stage turbine side structure and the booster pump. The last evaporator is connected to the last-stage compression side structure, the first-stage turbine side structure and the additional turbine at one end, and connected to the gas cooler, the booster pump and the gas storage chamber at the other end.

[0047] It should be noted that the high-temperature gas discharged from the compression side structure enters the steam generator for heat exchange, and the heat generated during the compression process can be recovered. The gas from the gas storage chamber will be reheated in the steam generator before entering the turbine side structure. The previously stored compression side heat can be used to increase the inlet temperature of the gas entering the turbine, thereby increasing the working efficiency of the turbine and improving the overall system electric-to-electric conversion efficiency. The steam generator can use the recovered heat to generate steam, which can be further used to drive additional turbines or other thermal equipment to achieve efficient energy conversion. The steam generator can also transfer excess heat to the phase change material or hot water in the heat storage tank for subsequent use, which helps to improve the overall thermal efficiency of the system and reduce energy loss. The heat distribution can be dynamically adjusted according to the needs of the system.

[0048] Specifically, the pipe wall energy conservation equation of the steam generator is:

[0049]

[0050] Where c W is the specific heat capacity of the pipe; p W is the density of the metal pipe wall; A W is the heat transfer area of the pipe wall; L is the length of the pipe; a0 is the convective heat transfer coefficient between the heat source and the pipe wall; T0 is the temperature of the heat source outside the pipe; T W is the pipe wall temperature; a i , T i , A iThe convective heat exchange coefficient of the additional heat source working medium and the pipe wall, the temperature of the additional heat source outside the pipe, and the heat exchange area of the additional working medium and the pipe wall (calculated based on the entering heat source);

[0051] The single-phase convective heat exchange coefficient of the working medium in the steam generator flowing in the pipe and exchanging heat is:

[0052]

[0053] In the formula, h is the heat exchange coefficient, Re is the Reynolds number, Pr is the Prandtl number, d is the hydraulic diameter, and k is a constant coefficient of different working media. e The hydraulic diameter is k, a constant coefficient of different working media.

[0054] In the embodiment of the present application, one end of the first gas cooler is connected to the first steam generator, and the other end is connected to the second stage compression side structure. One end of the second gas cooler is connected to the second steam generator, and the other end is connected to the third stage compression side structure. The last gas cooler is connected to the last steam generator at one end and to the gas storage chamber at the other end.

[0055] It should be noted that in the multi-stage compression process, the temperature of the air after each stage of compression will increase significantly. The gas cooler cools the high-temperature gas discharged from the steam generation area on the compression side to an appropriate temperature through heat exchange with the cooling medium, reducing the energy consumption in the subsequent compression process and preventing equipment damage due to overheating. By reducing the gas temperature, the volume of the gas can be reduced, thereby improving the suction efficiency of the next stage compressor. In addition, the excess heat in the steam generator can be used for other purposes, such as user heating, by using heat exchange working medium (such as heat conducting oil), thereby improving the overall energy utilization rate of the system.

[0056] In the embodiment of the present application, it further includes an additional turbine.

[0057] The additional turbine is connected to each steam generator at one end and to the condenser at the other end, and is used to generate residual heat energy through the reheated gas of each steam generator for turbine power generation.

[0058] It can be understood that the additional turbine of the embodiment of the present application extracts the remaining energy by further expanding the reheated gas of each steam generator and converts it into electric energy, fully utilizing the low-grade heat energy that would otherwise be wasted, thereby improving the overall power generation efficiency of the system.

[0059] In the embodiment of the present application, it further includes a condenser.

[0060] The condenser is connected to the last stage turbine side structure and the additional turbine at one end, and is connected to the booster pump at the other end, and is used to cool the gas discharged from the last stage turbine side structure and the additional turbine.

[0061] It can be understood that the condenser of the embodiment of the present application is responsible for cooling the gas discharged from the turbine. Since the turbine releases a large amount of heat during the power generation process, the temperature of the exhaust gas is relatively high. Therefore, the condenser lowers the temperature of this part of the high-temperature gas by heat exchange with the cooling medium (such as cold water) for subsequent processing or recycling. At the same time, the heat in this part of the gas is recovered and used for the reheating process inside the system, thereby improving the overall thermal efficiency of the system.

[0062] Specifically, the heat transfer coefficient of the condenser is:

[0063]

[0064] Where: λ is the thermal conductivity; μ is the dynamic viscosity; T s is the temperature of the working medium in the condenser; g and γ are coefficient constants; ρ L is the density of the cold working medium; (ρ L -ρ V ) is the density difference between the cold and hot working fluids.

[0065] In the embodiment of the present application, it also includes: a booster pump.

[0066] One end of the booster pump is connected to the condenser, and the other end is connected to each steam generator, so as to re-pressurize the gas discharged from the condenser and send it back to the steam generator.

[0067] It can be understood that the booster pump of the embodiment of the present application ensures that the gas can smoothly re-enter the steam generator from the condenser, so that the gas pressure is restored to a sufficiently high level so that it can re-enter the system circulation, so as to facilitate the subsequent effective reuse of the gas, thereby improving the overall energy utilization.

[0068] Specifically, the output work expression of the booster pump is:

[0069] W pump =m wf (h out -h in )(1.3a)

[0070] In formula (1.3a), m wf is the mass flow rate of the working fluid; h is the specific enthalpy of the working fluid;

[0071] The pump flow rate is:

[0072]

[0073] Where n is the pump speed; n0 is the initial speed; q0 is the initial flow rate.

[0074] In the embodiment of the present application, it also includes: a heat storage tank.

[0075] One end of the heat storage tank is connected to each steam generator, and the other end is connected to the target reheating device for storing excess heat.

[0076] It can be understood that the heat storage tank of the embodiment of the present application is used to store excess heat generated in the system, which can be generated in the compression process or recovered from the gas discharged from the turbine, and the supply of heat can be dynamically adjusted according to the demand of the system. When the heat in the system is insufficient, the heat storage tank can release the previously stored heat to supplement the heat demand of the system, so as to maintain a stable operating state under different working conditions and avoid affecting the efficiency of the system due to insufficient heat.

[0077] In the embodiment of the present application, the target reheating device further comprises: a photo-thermal heat collection device and an electric heating device, wherein the target reheating device is connected to the heat storage tank for collecting solar energy to supplement the heat in the heat storage tank and reheating the heat medium in the heat storage tank.

[0078] It can be understood that the target reheating device of the embodiment of the present application can collect solar energy to supplement the missing heat when the heat in the steam generator is insufficient, so as to provide additional heat energy for the system, thereby improving the energy conversion efficiency of the entire system. In addition, the heat medium in the heat storage tank can supplement the heat required by the steam generator for reheating the gas on the turbine side, thereby increasing the temperature of the gas entering the inlet of the two-stage turbine on the turbine side, improving the electric-to-electric conversion efficiency of the system, and further improving the power generation efficiency of the entire system.

[0079] It should be noted that the target reheating device can be any device suitable for reheating the heat medium in the heat storage tank, including but not limited to an electric heating device.

[0080] Specifically, the heat production power model of the heat collection device is:

[0081] Q sf = A sf DNI t I L I T η OPT,R η END η CLN σ(1.4)

[0082] In the formula: A sf is the mirror field area of the photo-thermal heat collection system; DNI t is the direct normal irradiance of the sun at time t; I L and I T are the longitudinal and transverse components of the incident angle correction factor, respectively; η OPT,R is the optical efficiency of the mirror field; η ENDη is the terminal light loss efficiency; η CLN σ is the cleanliness coefficient; σ is the heat exchange coefficient of the solar cooler.

[0083] The compressed air energy storage system with inter-stage waste heat recovery cycle provided by the embodiment of the present application has a steam generator shared by the compression side structure and the turbine side structure of each stage, heat exchange is performed on the gas waste heat of the compression side structure and the turbine side structure, and heat is provided externally. The gas cooler of the compression side structure of each stage is arranged behind the steam generator and is used for cooling the gas after heat exchange, so that the gas can be cooled to a suitable stable temperature suitable for being introduced into the inlet of the next stage compressor, the traditional multiple heat exchangers are replaced, energy waste is avoided, and the energy recovery efficiency and the energy conversion efficiency are improved, so that the inter-stage waste heat can be fully utilized for re-compression and expansion power generation with the turbine side structure, the heat working medium in the heat storage tank can supplement the heat required for reheating the turbine side gas by the steam generator, the temperature of the gas at the inlet of the turbine of the turbine side can be increased, and the power generation efficiency of the entire system is improved.

[0084] The compressed air energy storage system with inter-stage waste heat recovery cycle provided by the embodiment of the present application has a steam generator shared by the compression side structure and the turbine side structure of each stage, heat exchange is performed on the gas waste heat of the compression side structure and the turbine side structure, and heat is provided externally. The gas cooler of the compression side structure of each stage is arranged behind the steam generator and is used for cooling the gas after heat exchange, so that the gas can be cooled to a suitable stable temperature suitable for being introduced into the inlet of the next stage compressor, the traditional multiple heat exchangers are replaced, energy waste is avoided, and the energy recovery efficiency and the energy conversion efficiency are improved, so that the inter-stage waste heat can be fully utilized for re-compression and expansion power generation with the turbine side structure, the heat working medium in the heat storage tank can supplement the heat required for reheating the turbine side gas by the steam generator, the temperature of the gas at the inlet of the turbine of the turbine side can be increased, and the power generation efficiency of the entire system is improved. Figure 2 Figure 3 The operation method of the compressed air energy storage system with inter-stage waste heat recovery cycle provided by the embodiment of the present application will be described below.The compressed air energy storage system with inter-stage waste heat recovery cycle provided by the embodiment of the present application has a steam generator shared by the compression side structure and the turbine side structure of each stage, heat exchange is performed on the gas waste heat of the compression side structure and the turbine side structure, and heat is provided externally. The gas cooler of the compression side structure of each stage is arranged behind the steam generator and is used for cooling the gas after heat exchange, so that the gas can be cooled to a suitable stable temperature suitable for being introduced into the inlet of the next stage compressor, the traditional multiple heat exchangers are replaced, energy waste is avoided, and the energy recovery efficiency and the energy conversion efficiency are improved, so that the inter-stage waste heat can be fully utilized for re-compression and expansion power generation with the turbine side structure, the heat working medium in the heat storage tank can supplement the heat required for reheating the turbine side gas by the steam generator, the temperature of the gas at the inlet of the turbine of the turbine side can be increased, and the power generation efficiency of the entire system is improved.

[0085] (1) Start the compression process and the turbine process

[0086] The compressed air energy storage system with inter-stage waste heat recovery cycle provided by the embodiment of the present application has a steam generator shared by the compression side structure and the turbine side structure of each stage, heat exchange is performed on the gas waste heat of the compression side structure and the turbine side structure, and heat is provided externally. The gas cooler of the compression side structure of each stage is arranged behind the steam generator and is used for cooling the gas after heat exchange, so that the gas can be cooled to a suitable stable temperature suitable for being introduced into the inlet of the next stage compressor, the traditional multiple heat exchangers are replaced, energy waste is avoided, and the energy recovery efficiency and the energy conversion efficiency are improved, so that the inter-stage waste heat can be fully utilized for re-compression and expansion power generation with the turbine side structure, the heat working medium in the heat storage tank can supplement the heat required for reheating the turbine side gas by the steam generator, the temperature of the gas at the inlet of the turbine of the turbine side can be increased, and the power generation efficiency of the entire system is improved.

[0087] The compressed air energy storage system with inter-stage waste heat recovery cycle provided by the embodiment of the present application has a steam generator shared by the compression side structure and the turbine side structure of each stage, heat exchange is performed on the gas waste heat of the compression side structure and the turbine side structure, and heat is provided externally. The gas cooler of the compression side structure of each stage is arranged behind the steam generator and is used for cooling the gas after heat exchange, so that the gas can be cooled to a suitable stable temperature suitable for being introduced into the inlet of the next stage compressor, the traditional multiple heat exchangers are replaced, energy waste is avoided, and the energy recovery efficiency and the energy conversion efficiency are improved, so that the inter-stage waste heat can be fully utilized for re-compression and expansion power generation with the turbine side structure, the heat working medium in the heat storage tank can supplement the heat required for reheating the turbine side gas by the steam generator, the temperature of the gas at the inlet of the turbine of the turbine side can be increased, and the power generation efficiency of the entire system is improved.

[0088] (2) Start the waste heat cycle process

[0089] The gas discharged from the turbine T2 is cooled by a condenser, pressurized by a booster pump and then re-enters the steam generator, part of which is used to enter T0 to generate electricity by turbine, and part of the gas and the gas discharged from the compressor re-enters the gas cooler to perform the previous compression process. If the heat in the steam generator is not enough, the heat is supplemented by a solar heat collector, and the excess heat of the collector is used for user heating. If there is excess heat in the steam generator, the excess heat can also be collected by the heat storage device for heating.

[0090] In the description of the present specification, the description of the terms "one embodiment", "some embodiments", "an example", "a specific example", or "some examples" and the like means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any appropriate manner in any one or N embodiments or examples. In addition, the person skilled in the art can combine and combine the different embodiments or examples described in the present specification and the features of the different embodiments or examples without contradiction.

[0091] In addition, the terms "first", "second" are only for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined with "first", "second" can explicitly or implicitly include at least one of the features. In the description of the present application, the meaning of "N" is at least two, for example, two, three, etc., unless otherwise specifically limited.

[0092] It should be understood that parts of the present application can be realized by hardware, software, firmware or a combination thereof. In the above-described embodiments, N steps or methods can be realized by software or firmware stored in a memory and executed by a suitable instruction execution system. As in another embodiment, if realized by hardware, any one or a combination of the following technologies known in the art can be used: discrete logic circuit with logic gate circuit for implementing logic functions on data signals, application specific integrated circuit with suitable combination logic gate circuit, programmable gate array (PGA), field programmable gate array (FPGA), etc.

[0093] Those skilled in the art of the present technology can understand that all or part of the steps carried out by the above-mentioned embodiment method can be completed by a program instructing the relevant hardware, and the program can be stored in a computer readable storage medium. The program, when executed, includes one of the steps of the method embodiment or a combination thereof.

Claims

1. A method of operating a compressed air energy storage system with inter-stage waste heat recovery, characterized in that, The compressed air energy storage system comprises a gas storage chamber, a generator, a plurality of compression side structures and a plurality of turbine side structures, each compression side structure and each turbine side structure sharing a steam generator, wherein the steam generator exchanges heat with the gas waste heat of the compression side structure and the turbine side structure, and provides heat to the outside, and the last turbine side structure is connected with the generator; a gas cooler of each compression side structure is arranged behind the steam generator, wherein the gas cooler is used for cooling the gas after heat exchange, the gas cooler is connected with the next compression side structure, and the gas cooler of the last compression side structure is connected with the gas storage chamber; wherein the method comprises the following steps: After the air to be compressed is input into the first compression side structure for gas compression, the first steam generator is controlled to exchange heat with the gas compressed by the first compression side structure; the gas after heat exchange is input into the second compression side structure for re-compression work, and then input into the second steam generator, and the operation is sequentially and circularly performed until the last steam generator exchanges heat with the gas compressed by the last compression side structure and sends the gas to the gas cooler for cooling and then stores the gas into the gas storage chamber; The gas from the gas storage chamber is reheated by the last steam generator, the gas after reheating is input into the first turbine side structure for turbine power generation, and then the gas discharged from the first turbine side structure is input into the second last steam generator for reheating, and the operation is sequentially and circularly performed until the first steam generator reheats the discharged gas and then inputs the gas into the last turbine side structure for turbine power generation; The compressed air energy storage system further comprises an additional turbine, a condenser and a booster pump, wherein one end of the additional turbine is connected with each steam generator, and the other end of the additional turbine is connected with the condenser, the residual heat energy of the gas reheated by each steam generator is input into the additional turbine for turbine power generation, one end of the condenser is connected with the last turbine side structure and the additional turbine, and the other end of the condenser is connected with the booster pump, the gas discharged from the last turbine side structure and the additional turbine is cooled by the condenser, so that the excess gas is compressed and stored and turbine power generation, respectively, and one end of the booster pump is connected with the condenser, and the other end of the booster pump is connected with each steam generator.

2. A method of operating a compressed air energy storage system with inter-stage waste heat recovery according to claim 1, characterized in that, One end of the first steam generator is connected to the first stage compression side structure, the last stage turbine side structure and the additional turbine, the other end is connected to the gas cooler, the last stage of the upper stage turbine side structure and the booster pump, one end of the second steam generator is connected to the second stage compressor structure, the last stage of the upper stage turbine side structure and the additional turbine, the other end is connected to the gas cooler, the third last stage turbine side structure and the booster pump, sequentially connected, one end of the last steam generator is connected to the last stage compression side structure, the first stage turbine side structure and the additional turbine, the other end is connected to the gas cooler, the booster pump and the gas storage chamber, one end of the first gas cooler is connected to the first steam generator, the other end is connected to the second stage compression side structure, one end of the second gas cooler is connected to the second steam generator, the other end is connected to the third stage compression side structure, sequentially connected, one end of the last gas cooler is connected to the last steam generator, the other end is connected to the gas storage chamber.

3. A method of operating a compressed air energy storage system with inter-stage waste heat recycling according to claim 1, characterized in that, The gas discharged from the condenser is re-pressurized and sent back to the steam generator.

4. A method of operating a compressed air energy storage system with inter-stage waste heat recycling according to claim 1, characterized in that, The compressed air energy storage system further comprises a heat storage tank and a target reheating device, wherein one end of the heat storage tank is connected to each steam generator, and the other end is connected to the target reheating device.

5. A method of operating a compressed air energy storage system with inter-stage waste heat recycling according to claim 4, characterized in that, The target reheating device comprises a photo-thermal heat collection device and an electric heating device, which uses the photo-thermal heat collection device to collect solar energy to supplement the heat to the heat storage tank, and uses the electric heating device to heat the heat storage tank.

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