Compressed air energy storage co-production system

Abstract

The invention provides a compressed air energy storage co-production system, and relates to the technical field of compressed air energy storage co-production. According to the compressed air energy storage co-production system, compression heat generated by compressed air in the energy storage stage is taken out through the heat storage medium and stored in the heat tank; comprising a steam preparation unit, the steam preparation unit comprises a flash tank for preparing high-temperature steam by using heat of a hot tank, and the steam prepared by the flash tank is conveyed to a user side through a pipeline. According to the compressed air energy storage co-production system, besides compressed air energy storage power supply, compression heat can be used for producing industrial steam. Different from life heat supply, industrial steam is widely applied to the fields of food, pharmacy, spinning, papermaking, chemical engineering, building and the like and has requirements throughout the year, and economic benefits are high.

Description

Technical Field

[0001] This invention relates to the field of compressed air energy storage cogeneration technology, and in particular to a compressed air energy storage cogeneration system. Background Technology

[0002] Compressed air energy storage is a key technology for addressing grid instability in renewable energy connections. It enables the storage and release of electrical energy, playing a role in peak shaving and frequency regulation for the power grid. Among them, advanced adiabatic compressed air energy storage systems improve system energy efficiency through thermal storage technology and enable the system to have the potential for multi-energy utilization.

[0003] In the process of realizing this invention, the inventors discovered that the prior art has at least the following problems: the existing compressed air energy storage cogeneration system can only meet the basic heating needs such as heating and hot water supply by utilizing the waste heat inside the system, which has the technical problem of low economic benefits and limited application scenarios. Summary of the Invention

[0004] The purpose of this invention is to provide a highly economical compressed air energy storage cogeneration system.

[0005] To achieve this objective, on the one hand, a compressed air energy storage cogeneration system is provided, which extracts and stores the heat of compression generated by compressed air during the energy storage stage in a heat storage tank through a heat storage medium; it includes a steam preparation unit, which includes a flash tank that uses the heat of the heat tank to produce high-temperature steam, and the steam produced by the flash tank is transported to the user end through pipelines.

[0006] One of the above technical solutions has the following advantages or beneficial effects: The compressed air energy storage cogeneration system of this embodiment, in addition to storing compressed air for power generation, can also utilize the heat of compression to produce industrial steam. Unlike domestic heating, industrial steam has wide applications in food, pharmaceuticals, textiles, papermaking, chemicals, construction, and other fields, and there is a year-round demand, resulting in high economic benefits. Attached Figure Description

[0007] Figure 1 It is the compressed air energy storage cogeneration system provided in Example 1; Figure 2 It is the compressed air energy storage cogeneration system provided in Example 2; Figure 3 This is a compressed air energy storage cogeneration system provided in Embodiment 3; Figure 4 This is another compressed air energy storage cogeneration system provided in Example 3.

[0008] In the diagram: 10 - Electric motor; 11, 12, 13, 14 - Compressors; 21, 22, 23, 24 - Regenerators; 100 - Gas storage device; 30 - Engine; 31, 32, 33, 34 - Expanders; 41, 42, 43, 44 - Reheaters; 51, 52, 53, 54 - Cold energy recovery heat exchangers; 6 - Hot tank; 61, 62, 63 - Flash tanks; 71, 72 - Steam compressors; 64 - Auxiliary flash tank; 60 - Heating heat exchanger; 7 - Cold tank; 80 - Makeup water pipe; 500 - Water source heat pump unit; 510 - Evaporator; 520 - Heat pump compressor; 530 - Condenser; 540 - Throttling valve; 700 - Medium temperature heat exchanger; 9 - Throttling valve. Detailed Implementation

[0009] To make the technical problems solved by the present invention, the technical solutions adopted, and the technical effects achieved clearer, the technical solutions of the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. It should be noted that, in the absence of conflict, the following embodiments and features in the embodiments can be combined with each other.

[0010] Example 1:

[0011] like Figure 1 As shown, the compressed air energy storage system includes a compressor unit, an expander unit, an air storage device, and a heat storage unit. During periods of low grid load, the heat storage unit uses an electric motor 10 to drive the compressor unit to compress air in multiple stages. The resulting high-pressure air is stored in the air storage device, while the large amount of heat generated during compression is recovered through a heat storage medium and stored in the heat storage unit. During periods of high grid load, the stored high-pressure air is preheated by the heat energy stored in the heat storage unit and then sent to the expander unit for multi-stage expansion, driving the generator 30 to generate electricity, thus completing the storage and release of electrical energy.

[0012] Existing combined heat and power (CHP) systems still have significant limitations in practical applications. After the compressed air energy storage system meets the expansion requirements, a large amount of medium- and low-temperature waste heat remains. Because this portion of heat has a low quality, existing CHP systems utilize this waste heat through corresponding equipment for basic domestic heating. However, the economic benefits of basic heating are poor, and the returns are limited by region and time.

[0013] The compressed air energy storage cogeneration system in this embodiment can supply not only compressed air energy storage for power generation, but also industrial high-pressure steam. Unlike domestic heating, industrial high-pressure steam has wide applications in food, pharmaceuticals, textiles, papermaking, chemicals, construction, and other fields, and there is a constant demand for it throughout the year.

[0014] like Figure 1 As shown, the compressed air energy storage cogeneration system of this embodiment includes a compressed air energy storage system, which includes an energy storage unit. The energy storage unit includes a multi-stage compressor. The figure shows a case where the energy storage unit includes four compressors connected in series, namely compressor 11, compressor 12, compressor 13, and compressor 14. All compressors are driven by off-peak electricity.

[0015] During periods of low electricity demand, the electric motor 10 is driven by the power grid or wind and solar power. The electric motor 10 drives the compressor to compress air. Outside air 20 enters the first-stage compressor 11, where it is compressed into high-temperature, medium-pressure air. This air then enters the first-stage regenerator heat exchanger 21, where it is cooled to room temperature. The room-temperature, medium-pressure air then enters the second-stage air compressor 12 for further compression. The compressed, high-temperature, high-pressure air then enters the second-stage regenerator heat exchanger 22 for heat exchange, and so on. After multiple compressions and coolings, the room-temperature, high-pressure air enters the air storage device 100 through pipe 15 for storage.

[0016] The compressed air energy storage system also includes a heat storage unit. Low-temperature medium 07 flows out of the cold tank 7 and is pressurized by a pump before being transported to the cold-side inlets of each section of the regenerating heat exchangers 21, 22, 23, and 24 to cool the high-temperature air on the hot side of each section. After passing through each section of the regenerating heat exchangers 21, 22, 23, and 24, the low-temperature medium 07 becomes high-temperature mediums 601, 602, 603, and 604, which flow into the main pipe 06 and are then transported to the hot tank 6 for storage. The high-temperature medium can be water, heat transfer oil, etc. In this embodiment, medium 07 is water; the cold tank 7 contains low-temperature water, and the hot tank 6 contains high-temperature water.

[0017] The compressed air energy storage cogeneration system of this embodiment also includes a steam preparation unit. The steam preparation unit comprises at least two flash tanks connected in series. The flash tanks are based on the fundamental laws of thermodynamics: the boiling point of a liquid decreases as ambient pressure decreases. When a high-pressure, high-temperature liquid suddenly enters a lower-pressure tank through a pressure-reducing valve, it instantly "superheats," causing some of the liquid to rapidly vaporize, generating steam which separates from the remaining liquid. The high-pressure, high-temperature liquid enters through the inlet of the flash tank, the steam flows out through the steam outlet, and the remaining unevaporated liquid flows out through the outlet.

[0018] The flash tank uses the high-temperature water in the hot tank 6 as the raw material liquid. The heat of the high-temperature water in the hot tank 6 comes from the heat of air compression in the energy storage stage of the compressed air energy storage system. Therefore, the steam preparation unit of this embodiment uses the heat of air compression recovered in the energy storage stage to prepare high-pressure steam.

[0019] Specifically, Figure 1 The diagram illustrates an embodiment where the steam preparation unit includes a three-stage flash tank. For example... Figure 1The heat of air compression is stored in a heat tank 6. High-temperature water 600 in the heat tank 6 enters the inlet of the first-stage flash tank 61 after passing through a water pump and a throttle valve 9. After flash evaporation, high-pressure steam and high-temperature saturated water required for industrial use are obtained. The high-pressure steam flows out from the gas phase outlet of the flash tank and enters the finished product steam input pipeline 70. The high-temperature saturated water flows out from the outlet of the flash tank through pipeline 610, passes through a pump and a throttle valve 9, and enters the inlet of the second-stage flash tank 62 as the raw material liquid for the second-stage flash tank 62.

[0020] High-temperature saturated water enters the secondary flash tank 62 through pipe 610 for flash evaporation. After flash evaporation, high-pressure steam 621 and high-temperature saturated water 620 are obtained. High-pressure steam 621 flows out from the gas phase outlet of the secondary flash tank 62, and high-temperature saturated water flows out from the liquid outlet of the secondary flash tank 62 through pipe 620.

[0021] Since some of the raw liquid "flashes" into steam after entering the flash tank from the inlet, the latent heat required can only be provided by the sensible heat of the remaining liquid. Therefore, the liquid temperature at the vapor phase outlet and liquid outlet of the flash tank will inevitably decrease. Consequently, the steam 621 at the vapor phase outlet of the secondary flash tank 62 may not meet the industrially required steam temperature. It should be noted that the steam preparation unit includes at least two flash tanks connected in series. The flash tank connected to the hot tank outlet is the first-stage flash tank, the liquid inlet of the second-stage flash tank is connected to the liquid outlet of the first-stage flash tank, and so on. It is foreseeable that the steam at the vapor phase outlet of one of the first-stage flash tanks will not meet the industrially required steam temperature; this could be the second-stage or third-stage flash tank, depending on the temperature of the liquid inlet of the first-stage flash tank. This embodiment uses the example of the steam 621 at the vapor phase outlet of the secondary flash tank 62 not meeting the industrially required steam temperature to illustrate the cogeneration system.

[0022] To address the technical problem that the steam 621 from the flash tank 62's steam outlet does not meet the temperature requirements for industrial steam, a steam compressor is installed at the outlet of the flash tank 62 in this embodiment. The vapor phase outlet of the flash tank 62 is connected to the inlet of the steam compressor 71. The steam 621 from the vapor phase outlet of the flash tank 62 is compressed by the steam compressor 71 to obtain high-temperature, high-pressure steam with a temperature that meets the requirements for industrial steam. The outlet of the steam compressor 71 is then connected to the finished product steam input pipeline 70.

[0023] The high-temperature saturated water 620 from the drain port of flash tank 62 enters the inlet of the third-stage flash tank 63 via a pump and throttle valve 9. It undergoes flash evaporation again within flash tank 63, resulting in medium-pressure steam and medium-temperature saturated water. The medium-pressure steam flows out of the vapor phase outlet of the third-stage flash tank 63 via pipe 631, while the medium-temperature saturated water flows out of the liquid phase outlet of the flash tank 63 via pipe 630. Since the steam in pipe 631 does not meet the industrial steam temperature requirements, a steam compressor 72 is also installed at the outlet of flash tank 63. Pipe 631 is connected to the inlet of steam compressor 72. After compression by steam compressor 72, high-pressure steam is obtained. The high-temperature, high-pressure steam flows into the finished product steam input pipe 70 and is transported to the location where the steam is used.

[0024] Furthermore, after a steam compressor is installed at the outlet of the flash tank 63, the outlet temperature of the steam compressor may be higher than the steam user's demand. Based on this, the outlet of the steam compressor in this embodiment is equipped with a spray device to reduce the outlet temperature of the steam compressor, so that the temperature of the high-pressure steam at the outlet of the steam compressor meets the downstream user's demand.

[0025] Optionally, a spray device is installed at the outlet of the first steam compressor 71 and / or at the outlet of the second steam compressor 72. The spray device includes a shell with a cavity. The outlet of the steam compressor is connected to the shell of the spray device. The high-pressure steam from the outlet of the steam compressor enters the spray device. The spray device is equipped with nozzles that spray saturated droplets. The latent heat of vaporization of the saturated droplets absorbs the heat of the superheated steam at the outlet of the steam compressor, thereby reducing the temperature of the steam at the outlet of the compressor. This ensures that the temperature of the high-pressure steam at the outlet of the steam compressor meets the requirements of the downstream user. The steam then flows from one end of the shell of the spray device into the finished steam input pipe 70.

[0026] The high-temperature, high-pressure steam 70 produced by the interconnected flash tanks and the steam compressor installed at the steam outlet of the later flash tanks is high-pressure superheated steam. High-pressure superheated steam has a large latent heat and is widely used in various industrial applications, thus having high economic value.

[0027] Furthermore, the medium-temperature saturated water in the drain pipe 630 of the flash tank 63 can still be used to generate saturated steam. That is, a flash tank is installed at the drain port of the flash tank 63, and a steam compressor is installed at the vapor phase outlet of the flash tank. The number of flash tanks and steam compressors can be determined according to the steam demand in the park.

[0028] In this embodiment, the cogeneration system utilizes the medium-temperature water from the outlet of the last-stage flash tank within the steam preparation unit for basic heating, such as for heating or hot water supply. Specifically, the system also includes a heat exchanger 60, whose hot-side inlet is connected to the outlet of the last-stage flash tank via a pipeline. Figure 1 An embodiment of a steam preparation unit with three flash tanks is shown. The outlet of the last flash tank 63 is connected to the hot-side inlet of a heat exchanger 60 via a pipe 630. The cold-side inlet of the heat exchanger 60 is water from a makeup water pipe, and the cold-side outlet of the heat exchanger 60 supplies heat to the user via a pipe 90.

[0029] Since the raw water for steam generation is taken from the heat tank 6 of the energy storage unit, which stores the system's compression heat, the water in the heat tank will decrease as steam is generated. Therefore, it is necessary to replenish water to and from the heat storage unit. The cogeneration system in this embodiment also includes a water replenishment unit, which includes a water replenishment pipe 80. The water in the water replenishment pipe 80 can be tap water at room temperature. Of course, when there is usable hot water in the system, hot water can also be directly added to the heat tank 6.

[0030] The water replenishment unit also includes a first branch 801 for replenishing water to the cold tank 7, and a second branch 802 for domestic heating. One end of the first branch 801 is connected to the water replenishment pipe 80, and the other end is connected to the liquid inlet pipe of the cold tank 7. The water replenishment pipe 80 replenishes water to the cold tank 7 through the first branch 801. The water replenished into the cold tank can first be used to recover the heat of compression, and the hot water after recovering the heat of compression is further replenished to the hot tank. One end of the second branch 802 is connected to the water replenishment pipe 80, and the other end is connected to the cold side inlet of the heating heat exchanger 60, which supplies heat to users.

[0031] In this embodiment, the medium-temperature saturated water in the drain outlet of the last-stage flash tank, after being heated by the heat exchanger 60, still retains some low-grade heat. This portion of heat, within a certain temperature range, can be used by the compressed air energy storage system to heat the compressed air at the expander inlet during energy release. Therefore, the hot-side inlet of the heat exchanger 60 is connected to the drain outlet of the last-stage flash tank, and the hot-side outlet of the heat exchanger 60 is connected to the hot-side inlet of the reheat heat exchanger via pipe 701. The cold side of the reheat heat exchanger contains the compressed air entering the expander, utilizing this low-grade heat to increase the temperature of the compressed air at the expander inlet.

[0032] The energy release unit of the compressed air energy storage system includes a multi-stage expander. The hot-side outlet pipe 701 of the heating heat exchanger 60 is connected to the water circuit of each reheat heat exchanger through various branch pipes. During energy release, the high-pressure ambient temperature air 101 released from the air storage device 100 first passes through the throttle valve 9 and then enters the air circuit of the first-stage reheat heat exchanger 41. The water inlet of the first-stage reheat heat exchanger 41 is connected to the pipe 701. In the first-stage reheat heat exchanger 41, the compressed air entering the first-stage expander 31 is heated by the hot water at the hot-side outlet of the heating heat exchanger 60. The heated air enters the first-stage expander 31, expands, and performs work to drive the engine 30. The outlet of the first-stage expander 31 is low-temperature compressed air.

[0033] The outlet of the first-stage expander 31 is the gas path through which low-temperature compressed air enters the second-stage reheat heat exchanger 42. After exchanging heat with the hot water in the water path of the second-stage reheat heat exchanger 42, it enters the second-stage expander 32 to expand and do work. Similarly, the low-temperature compressed air from the outlet of the second-stage expander 32 enters the gas path inlet of the third-stage reheat heat exchanger 43. After exchanging heat with the hot water in the water path of the third-stage reheat heat exchanger 43, it enters the third-stage expander 33 to expand and do work. The low-temperature compressed air from the outlet of the third-stage expander 33 enters the gas path inlet of the fourth-stage reheat heat exchanger 44. After exchanging heat with the hot water in the water path of the fourth-stage reheat heat exchanger 44, it enters the fourth-stage expander 34 to expand and do work. The pressure of the compressed air at the outlet of the fourth-stage expander 34 is close to that of the atmosphere and is directly discharged into the atmosphere.

[0034] In this embodiment, a cold energy recovery unit is also provided in the system. The cold energy recovery unit utilizes a cold storage medium to recover the cold energy of the low-temperature compressed air at the outlet of the expander through a heat exchanger. In this embodiment, the cold energy recovery unit includes at least two cold energy recovery heat exchangers, namely a first-stage cold energy recovery heat exchanger 51, a second-stage cold energy recovery heat exchanger 52, a third-stage cold energy recovery heat exchanger 53, and a fourth-stage cold energy recovery heat exchanger 54. The cold storage medium enters the hot side of the cold energy recovery heat exchanger through the cold storage medium inlet pipe 50. The hot side outlet of the cold energy recovery heat exchanger is connected to the cold energy recovery pipe 55, and the cold storage medium 55 after heat exchange is transported to the cooling area.

[0035] Optionally, a common cold storage medium such as a salt solution can be used, and pump 804 provides power to the cold energy recovery unit. The cold storage medium is pressurized by water pump 804 through pipeline 50 and obtains cooling capacity in cold energy recovery heat exchangers 51, 52, 53, and 54. The cooling capacity is then transported to the cooling location through pipeline 55.

[0036] In this embodiment, a portion of the cold energy after the expander is extracted by the cold energy recovery unit, and the other portion of the cold energy after the expander is stored in the cold tank within the system.

[0037] like Figure 1As shown, the low-temperature air after the expansion turbine 31 performs work enters the first-stage cold energy recovery heat exchanger 51, where it exchanges heat with the cold storage medium in the pipe 50, collecting the air's cold energy. The air after heat exchange enters the second-stage reheater 42, where it exchanges heat with the hot water in the hot-side outlet pipe 701 of the heating heat exchanger 60, and then enters the second-stage expansion turbine 32 to perform work. The low-temperature gas after performing work enters the second-stage cold energy recovery heat exchanger 52 to exchange heat, generating cold energy. The air after heat exchange exchanges heat with the hot water 701 in the third-stage reheater 43, and then enters the third-stage expansion turbine 33 to expand and perform work. The low-temperature gas after performing work enters the third-stage cold energy recovery heat exchanger 53 to exchange heat, generating cold energy. This process continues until the low-temperature air after expanding and performing work in the fourth-stage expansion turbine 34 enters the fourth-stage cold energy recovery heat exchanger 54, where it exchanges heat with the cold storage medium before being discharged into the atmosphere. The hot water in the hot side outlet pipe 701 of the heating heat exchanger 60, after heat exchange in the reheaters 41, 42, 43 and 44, flows into the main pipe 706 and enters the cold tank 7 through the main pipe 706.

[0038] Furthermore, the outlet of the cold tank 7 is equipped with a cold water pump 809, which provides power for the circulation of the cold medium between the cold tank 6 and the cold side of the regenerators 21, 22, 23, and 24.

[0039] Furthermore, the outlets of the hot tank 6 and flash tanks 61, 62, and 63 are equipped with hot water pumps 805, 806, 807, and 808 to provide power for subsequent flash evaporation of saturated water.

[0040] Therefore, the compressed air energy storage combined cooling, heating, and power (CCHP) system of this embodiment, in addition to providing compressed air energy storage for power generation, can also supply industrial steam, cooling, and basic heating. When supplying industrial steam, a multi-stage flash evaporation and multi-stage compression technology is used to continuously convert low-grade hot water into high-grade steam with relatively low compression work, achieving higher energy utilization and economic benefits. When providing cooling, a cold energy recovery unit independent of the system's cold tank is used to extract a portion of the cold energy after the expander, without causing fluctuations within the compressed air energy storage system. After providing basic heating from the medium-temperature saturated water in the drain of the downstream flash tank, some low-grade heat is still utilized in a cascade manner to achieve basic domestic heating. Therefore, the CCHP system of this embodiment fully utilizes the heat of compressed air to produce industrial steam, improves energy quality, enhances system economic efficiency, and has a wider range of applications.

[0041] Example 2:

[0042] like Figure 2 As shown, this example provides another compressed air energy storage cogeneration system, and the parts that are the same as in Example 1 will not be described again.

[0043] The compressed air energy storage cogeneration system of this embodiment is equipped with an auxiliary flash tank 64. Unlike the flash tank in Embodiment 1, the auxiliary flash tank 64 is independent of the steam preparation unit, and the finished high-pressure steam produced by both is transported through the same pipeline.

[0044] In this embodiment, the auxiliary flash tank is still equipped with a heating device at its inlet for heating the incoming liquid. Heating the temperature of the feed liquid entering the auxiliary flash tank 64 can reduce the number of flash tanks required. Optionally, the heating device for increasing the inlet water temperature of the auxiliary flash tank 64 can employ existing heating methods, such as electric heating.

[0045] Furthermore, in this embodiment, the heating device used to increase the inlet water temperature of the auxiliary flash tank 64 uses a water source heat pump unit 500. The water source heat pump unit has a large heating capacity and low power consumption, which makes the power generation efficiency of the compressed air energy storage system in this embodiment higher.

[0046] Specifically, the water source heat pump unit 500 includes an evaporator 510, a heat pump compressor 520, a condenser 530, and a throttling valve 540. A heat pump medium circulates within the water source heat pump unit 500, and the heat pump medium can be any refrigerant available in the prior art that can be used in heat pumps. The heat within the evaporator 510 comes from the heat tank 6, and the outlet of the heat tank 6 is connected to the hot side of the evaporator 510 via a pipe 600 to supply heat to the heat pump medium on its cold side.

[0047] The circulation process of the heat pump medium between the above-mentioned devices is as follows: the refrigerant of the heat pump medium in pipe 01 absorbs heat in evaporator 510 and becomes superheated gas 02 of the heat pump medium. After being compressed by heat pump compressor 520, it becomes high-temperature gaseous heat pump medium 03. After releasing heat in condenser 530, the heat pump medium becomes subcooled liquid 04. After being throttled and depressurized by throttling valve 540, it becomes room temperature and normal pressure liquid heat pump medium 01.

[0048] The hot side of condenser 530 receives high-temperature gaseous heat pump medium compressed by heat pump compressor 520. The cold side of condenser 530 forms a flash evaporation cycle with the inlet and outlet of the auxiliary flash tank. The cold side outlet of condenser 530 is connected to the inlet of auxiliary flash tank 64. The heated high-temperature water 640 enters the auxiliary flash tank 64, where it flashes to produce high-pressure steam 70 at the required pressure. The saturated high-temperature water at the outlet of auxiliary flash tank 64 is mixed with makeup water through pipe 641 to become medium-low temperature water. The hot water is then pressurized by a pump through pipe 642 and returns to the cold side inlet of condenser 530 to continue the flash evaporation cycle.

[0049] Because the flash evaporation cycle continuously generates high-pressure steam, circulating water needs to be added to the flash evaporation cycle. The system in this embodiment also includes a water replenishment unit, which includes a water replenishment pipe 80. The outlet of the water replenishment pipe 80 has a third branch 803, the other end of which is connected to the water outlet pipe 641 of the liquid outlet of the auxiliary flash tank 64, replenishing water to the flash evaporation cycle. The water in the water replenishment pipe 80 is at room temperature.

[0050] Furthermore, the hot-side inlet of the evaporator 510 of the water source heat pump unit is connected to the outlet of the heat tank 6. The heat pump medium is heated by the hot water in the heat tank 6. Although the temperature of the hot-side outlet of the evaporator 510 is reduced, it can still be used for basic heating. The system in this embodiment is also equipped with a heat exchanger for basic heating.

[0051] In this embodiment, the hot-side inlet of the heating heat exchanger 60 is connected to the hot-side outlet of the evaporator 510. The water supply unit also includes a second branch 802 located at the outlet of the water supply pipe 80, which is used for basic heating. The second branch 802 is connected to the cold-side inlet of the heating heat exchanger 60. After being heated by the hot side of the heating heat exchanger 60, the warm water from the cold-side outlet of the heating heat exchanger 60 is introduced into the basic heating equipment. The basic heating can be for both heating and hot water supply.

[0052] In this embodiment, the hot tank is connected to the hot-side inlet of the evaporator 510 of the water source heat pump unit to increase the heat output of the water source heat pump. The waste heat from the hot-side outlet of the evaporator 510 is first used for basic heating. In this system, after the medium-temperature water from the hot-side outlet of the evaporator 510 is used for basic heating, it still retains some low-grade heat. The temperature range of this portion of heat can be used by the compressed air energy storage system to heat the compressed air at the inlet of the expander during energy release. Therefore, the hot-side outlet of the heating heat exchanger 60 is connected to the hot-side inlet of the reheat heat exchanger through pipe 701. The cold side of the reheat heat exchanger contains the compressed air entering the expander, and the aforementioned low-grade heat is used to increase the temperature of the compressed air at the inlet of the expander.

[0053] Therefore, in this embodiment of the compressed air energy storage combined cooling, heating, and power system, when supplying industrial steam, a water source heat pump unit is coupled with a flash tank to form a flash cycle, utilizing a single flash tank to continuously produce industrial steam. Furthermore, the system in this embodiment can control the temperature of the high-pressure steam at the vapor outlet of the flash tank by controlling the heat pump, ensuring it meets the user's requirements for steam pressure and temperature. Moreover, this system, due to the use of a heat pump with low power consumption but high heat output, has low energy consumption and low cost, and the steam temperature can be flexibly adjusted according to the heat pump.

[0054] Example 3:

[0055] like Figure 3 As shown, this example provides another compressed air energy storage cogeneration system, and the parts that are the same as in Example 1 and Example 2 will not be described again.

[0056] In this embodiment of the compressed air energy storage cogeneration system, in order to increase the steam production capacity, the steam production equipment includes both a steam preparation unit and an auxiliary flash tank, which has the advantage of large saturated steam production capacity.

[0057] Specifically, the steam preparation unit includes at least two flash tanks connected in series and a steam compressor. A water source heat pump unit 500 is installed at the drain port of the last-stage flash tank. The saturated water in the last-stage flash tank provides heat to the evaporator 510 of the water source heat pump unit 500. The cold-side outlet of the condenser 530 within the water source heat pump unit 500 is connected to the inlet of the auxiliary flash tank 64 via a pipe 640, utilizing the heat generated inside the water source heat pump unit to raise the temperature of the liquid entering the auxiliary flash tank 64.

[0058] Specifically, the steam preparation unit includes at least two flash tanks connected in series and a steam compressor. A water source heat pump unit 500 is installed at the drain port of the last-stage flash tank. The saturated water in the last-stage flash tank provides heat to the evaporator 510 within the water source heat pump unit 500. The cold-side outlet of the condenser 530 within the water source heat pump unit 500 is connected to the inlet of the auxiliary flash tank 64 via a pipe 640, utilizing the heat generated inside the water source heat pump unit to raise the temperature of the liquid entering the auxiliary flash tank 64.

[0059] The operation process of the compressed air energy storage system for combined cooling, heating, and power (CCHP) in this embodiment is as follows: During energy storage, the high-temperature hot water from the compressed air is stored in the hot water tank 6. The high-temperature hot water passes through pump 805 and throttle valve 9 before entering the flash tank 61 of the steam preparation unit. After flash evaporation, high-pressure steam 70 and high-temperature saturated water 610 are obtained. The high-temperature saturated water 610 passes through pump 806 and throttle valve 9 before entering the flash tank 62 for further flash evaporation, resulting in medium-pressure steam 621 and medium-temperature saturated water 620. The medium-pressure steam 621 is compressed by steam compressor 71 to obtain high-temperature steam 70. The medium-temperature saturated water 620 passes through pump 807 and throttle valve 9 before entering the flash tank 63 for further flash evaporation, resulting in medium-pressure steam 631 and medium-temperature saturated water 630. The medium-pressure steam 631 is compressed by steam compressor 72 to obtain high-pressure steam 70, which is then transported to locations requiring industrial saturated steam.

[0060] In this embodiment, the medium-temperature saturated water 630 from the drain outlet of the last-stage flash tank 63 is pumped to the water source heat pump unit 500 via pump 808. After being pressurized by pump 808, the medium-temperature water 630 enters the evaporator 510 of the water source heat pump unit 500. After releasing heat to the heat pump medium in the evaporator 510, the medium-temperature water 701 is pumped to the hot-side inlet of each reheater in the energy release stage for heating the inlet gas temperature of the expander via pump 802. After completing the heat exchange, it returns to the cold water tank 7 from the hot-side outlet of each reheater.

[0061] The condenser 530 of the water source heat pump unit 500 provides high-temperature water for steam preparation to the auxiliary flash tank 64. Specifically, the hot-side inlet of the condenser 530 of the water source heat pump unit 500 is connected to the outlet of the heat pump compressor 520. The high-temperature heat pump medium from the outlet of the heat pump compressor 520 flows into the hot-side inlet of the condenser 530, and the cold-side outlet of the condenser 530 is connected to the auxiliary flash tank 64. The water heated by the condenser 530 enters the auxiliary flash tank 64 through the throttle valve 9. The high-pressure steam 70 flashed out of the auxiliary flash tank 64 flows into the main steam pipeline. The high-temperature saturated water 641 from the water outlet of the auxiliary flash tank 64 merges with the makeup water 83 from the makeup water unit, is pressurized by the pump, and then absorbs heat in the condenser 530 to continue the circulation.

[0062] Because a large amount of high-pressure steam is generated during continuous flash evaporation and flash cycle, the system requires additional water. After passing through pump 810, part of the water from the water supply pipe 80 of the water supply unit merges with the cold water from the outlets of the various reheaters of the energy release unit through the first branch 801 and then enters the cold tank 7 through pipe 07. The other part of the water supply from the water supply pipe 80 merges with the high-temperature saturated water 641 in the flash cycle through pipe 803 and then continues the flash cycle through pipe 642.

[0063] Furthermore, a spray device is installed at the outlet of each of the steam compressors 71 and 72. The spray device is used to reduce the superheat of the superheated steam at the outlet of the steam compressor. The spray device sprays saturated droplets, which absorb the heat of the superheated steam at the outlet of the steam compressor by utilizing the latent heat of vaporization of the saturated droplets, thereby reducing the temperature of the steam at the outlet of the compressor, reducing the superheat of the steam, and keeping the steam in a low superheated state.

[0064] Furthermore, such as Figure 4 The combined production system of this embodiment is also equipped with a medium-temperature heat exchanger 700. The medium-temperature heat exchanger 700 also uses the waste heat of the hot side outlet of the evaporator 510 to heat the temperature of the makeup water entering the flash evaporation cycle, thereby increasing the inlet temperature of the auxiliary flash tank 64 and increasing the high-pressure steam output of the auxiliary flash tank 64.

[0065] The outlet of the water supply pipe 80 of the water supply unit also has a fourth branch 804, which is used to supply water to the cold side of the medium temperature heat exchanger 700.

[0066] The hot-side inlet of the intermediate-temperature heat exchanger 700 is connected to the hot-side outlet of the evaporator 510 via pipe 632. The intermediate-temperature heat exchanger 700 uses the intermediate-temperature water from the hot-side outlet of the evaporator 510 to preheat the water entering the auxiliary flash cycle, thereby increasing the cold-side inlet water temperature of the condenser and improving the efficiency of the auxiliary flash cycle. The intermediate-temperature heat storage medium flowing out from the hot-side outlet of the intermediate-temperature heat exchanger 700 enters the water path of the reheater at the inlet of the high-pressure stage expander, raising the temperature of the high-pressure compressed air entering the reheater 41. Optionally, the heat source for the reheater 42 at the inlet of the second-stage expander also comes from the intermediate-temperature heat storage medium at the hot-side outlet of the intermediate-temperature heat exchanger 700.

[0067] Furthermore, in this embodiment, the hot-side outlet of the evaporator 510 is connected to the inlet of the remaining reheater water passages via a pipe 701. Optionally, the hot-side outlet of the evaporator 510 is connected to the water passages of the reheater 43 and reheater 44 located at the inlet of the low-pressure stage expander via a pipe 701.

[0068] The compressed air energy storage cogeneration system in Examples 1 to 3 synchronously converts intermittent electrical energy into stable cold, heat, and electricity as multiple terminal energy sources, effectively overcoming the problems of poor coordination and low efficiency in traditional energy supply modes. Furthermore, the utilization of heat is not limited to basic heating; it can produce industrial steam with higher economic value, thereby improving the comprehensive energy efficiency of the compressed air energy storage system and enhancing the overall economic benefits of the compressed air energy storage cogeneration system.

[0069] In the description of this invention, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0070] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0071] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A compressed air energy storage and cogeneration system, characterized in that, The heat generated by compressed air during the energy storage stage is extracted and stored in a heat storage tank through a heat storage medium. It includes a steam preparation unit, which includes a flash tank that uses the heat from a hot tank to produce high-pressure steam. The steam produced by the flash tank is delivered to the user end through pipelines.

2. The compressed air energy storage and cogeneration system according to claim 1, characterized in that, It also includes an auxiliary flash tank, the inlet of which is equipped with a heating device, and the unevaporated steam at the outlet of the auxiliary flash tank is returned to the inlet of the auxiliary flash tank to form a flash circulation.

3. The compressed air energy storage and cogeneration system according to claim 1, characterized in that, It also includes a water source heat pump unit with an internally circulating heat pump medium. The water source heat pump unit includes an evaporator, and the hot water in the heat tank of the compressed air energy storage system is used to heat the heat pump medium in the evaporator.

4. The compressed air energy storage and cogeneration system according to claim 3, characterized in that, The water source heat pump unit also includes a condenser, in which the heat released by the heat pump medium is used to increase the temperature of the liquid entering the flash tank.

5. The compressed air energy storage and cogeneration system according to claim 2, characterized in that, The heating device is a water source heat pump unit that uses an internally circulating heat pump medium. The water source heat pump unit includes an evaporator and a condenser. It also includes a medium-temperature heat exchanger, which uses the waste heat from the hot-side outlet of the evaporator to heat the temperature of the liquid used for flash evaporation. The waste heat from the hot side outlet of the evaporator is used once by the medium-temperature heat exchanger and then used to heat the compressed air at the inlet of the expander.

6. The compressed air energy storage and cogeneration system according to claim 1, characterized in that, The heat from the outlet of the last-stage flash tank in the steam preparation unit is used to heat the compressed air at the inlet of the expander; Alternatively, the heat from the outlet of the last-stage flash tank in the steam preparation unit can be used first for domestic heating and then for heating the compressed air at the inlet of the expander.

7. The compressed air energy storage cogeneration system according to claim 3, characterized in that, In a water source heat pump unit, the heat from the hot side outlet of the evaporator is used to heat the compressed air at the inlet of the expander.

8. The compressed air energy storage and cogeneration system according to claim 3, characterized in that, The heat from the hot-side outlet of the evaporator in the water source heat pump unit is used for domestic heating.

9. The compressed air energy storage and cogeneration system according to claim 1, characterized in that, The steam preparation unit includes at least two flash tanks connected in series, and a steam compressor to increase the steam temperature is installed at the steam outlet of each of the later flash tanks.

10. The compressed air energy storage and cogeneration system according to claim 1, characterized in that, It also includes a cold energy recovery unit, which includes at least two cold energy recovery heat exchangers. The heat exchangers are respectively located at the outlets of different expanders, and the cold energy after the expander is extracted through the cold energy recovery unit.

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