Cogeneration energy storage system and method for producing industrial steam

Abstract

The present invention belongs to the field of energy storage technology, and relates to a cogeneration energy storage system for producing industrial steam, including a compressor, a precooler, a cooler and a gas storage tank, a low-temperature molten salt tank; a high-temperature molten salt tank, the inlet of which is connected to the second outlet of the precooler, and the high-temperature molten salt tank is used to store high-temperature molten salt; a medium-temperature water tank, the outlet of which is connected to the second inlet of the cooler, and medium-temperature high-pressure water is stored in the medium-temperature water tank; an industrial steam supply component, which is respectively connected to the outlet of the high-temperature molten salt tank and the second outlet of the cooler, and is used to heat the medium-temperature high-pressure water by the compression heat generated by the compressor, so that the medium-temperature high-pressure water becomes high-temperature industrial steam. The present invention can use the compression heat generated by the redundant power driving the compressor during the electricity consumption valley period to heat the medium-temperature high-pressure water, so that the medium-temperature high-pressure water becomes high-temperature industrial steam, and continuously supply high-temperature industrial steam to the industrial park, avoiding the relatively single energy conversion during the energy storage process, and improving the energy utilization rate of the system.

Description

Technical Field

[0001] The invention belongs to the technical field of energy storage, and relates to a cogeneration energy storage system and method for producing industrial steam. Background Art

[0002] Industrial parks are the new focus of regional economic development. They gather many manufacturing companies, have large electricity demand and high requirements for power supply quality. When the power distribution system of industrial parks is disturbed internally or externally, the important power loads of industrial parks still need to maintain continuous and stable power supply, which requires an additional independent power supply system to flexibly dispatch the power distribution of industrial parks. The application of energy storage technology can largely solve the problem of flexible dispatch of power distribution in industrial parks, so that many manufacturing companies in industrial parks can obtain continuous and high-quality power supply.

[0003] At present, industrial parks often use compressed air energy storage technology when storing energy. When electricity consumption is low, excess electricity is used to drive the compressor to compress the air for storage, and then converted into electricity to supply the industrial park during peak electricity consumption.

[0004] However, since industrial parks need not only electricity but also industrial steam, the energy conversion that can be achieved using compressed air energy storage technology is relatively simple, resulting in the need for enterprises in industrial parks to prepare industrial steam through electricity, which reduces the energy utilization rate of the system. Summary of the invention

[0005] The purpose of the present invention is to provide a cogeneration energy storage system and method for producing industrial steam, which can continuously provide industrial steam to industrial parks during the energy storage process, avoid relatively single energy conversion during the energy storage process, and improve the energy utilization rate of the system.

[0006] To achieve the above objectives, the specific technical solutions of the cogeneration energy storage system and method for producing industrial steam provided by the present invention are as follows:

[0007] A heat and power cogeneration energy storage system for producing industrial steam, comprising a compressor, a precooler, a cooler and a gas storage tank, wherein the inlet of the compressor is used to introduce air at normal temperature and pressure, the outlet of the compressor is connected to the first inlet of the precooler, the first outlet of the precooler is connected to the first inlet of the cooler, the first outlet of the cooler is connected to the gas storage tank, and further comprising:

[0008] A low-temperature molten salt tank, the outlet of which is connected to the second inlet of the precooler, and the low-temperature molten salt tank is used to store low-temperature molten salt;

[0009] A high-temperature molten salt tank, the inlet of which is connected to the second outlet of the precooler, and the high-temperature molten salt tank is used to store high-temperature molten salt;

[0010] A medium-temperature water tank, the outlet of which is connected to the second inlet of the cooler, and the medium-temperature water tank stores medium-temperature high-pressure water;

[0011] The industrial steam supply component is connected to the outlet of the high-temperature molten salt tank and the second outlet of the cooler respectively, and is used to heat the medium-temperature and high-pressure water through the compression heat generated by the compressor, so that the medium-temperature and high-pressure water is converted into high-temperature industrial steam.

[0012] The present invention is also characterized in that:

[0013] The industrial steam supply component includes a flash tank, a steam tank and a steam generator. The inlet of the flash tank is connected to the second outlet of the cooler, the inlet of the steam tank is connected to the first outlet of the flash tank, the first outlet of the steam tank is connected to the first inlet of the steam generator, the first outlet of the steam generator is used to supply high-temperature industrial steam to the industrial park, the second inlet of the steam generator is connected to the outlet of the high-temperature molten salt tank, and the second outlet of the steam generator is connected to the inlet of the low-temperature molten salt tank.

[0014] A hot water tank is arranged between the cooler and the flash tank, the first channel of the hot water tank is respectively connected to the second outlet of the cooler and the inlet of the flash tank, the second channel of the hot water tank is connected to the first channel of the buffer tank, the second channel of the buffer tank is connected to the gas storage tank, and the third channel of the buffer tank is connected to the medium-temperature water tank.

[0015] A pump is arranged between the medium-temperature water tank, the flash tank and the steam tank. The inlet of the pump is connected to the second outlet of the flash tank and the second outlet of the steam tank respectively, and the outlet of the pump is connected to the inlet of the medium-temperature water tank.

[0016] The outlet of the gas storage tank is connected to the first inlet of the heater, the first outlet of the heater is connected to the inlet of the turbine, the outlet of the turbine is connected to the atmosphere, and the second inlet of the heater is connected to the outlet of the return water tank.

[0017] A first control valve is provided at the inlet of the compressor, a second control valve is provided between the cooler and the gas storage tank, a third control valve is provided between the gas storage tank and the heater, a fourth control valve is provided on the first passage of the hot water tank, a ninth control valve is provided between the hot water tank and the buffer tank, a fifth control valve is provided at the inlet of the flash tank, a sixth control valve is provided between the flash tank and the steam tank, a seventh control valve is provided between the buffer tank and the medium-temperature water tank, a tenth control valve is provided between the buffer tank and the gas storage tank, an eighth control valve is provided between the medium-temperature water tank and the cooler, an eleventh control valve is provided between the precooler and the high-temperature molten salt tank, a twelfth control valve is provided between the steam generator and the low-temperature molten salt tank, and a thirteenth control valve is provided between the return water tank and the heater.

[0018] A heat and power cogeneration energy storage method for producing industrial steam includes energy storage, energy release and independent heat supply. The energy storage is used to convert excess electric energy during low electricity consumption into heat energy and compressed air for storage, and the heat energy is used to prepare industrial steam. The energy release is used to convert the stored high-pressure air into electric energy. The independent heat supply is used to continue to prepare industrial steam using the stored excess heat energy during the non-energy storage working stage. The energy storage includes the following steps:

[0019] Introduce normal temperature and pressure air into the compressor, and use the excess electricity during the low electricity consumption period to drive the compressor to work, so that the normal temperature and pressure air is converted into high temperature and high pressure air;

[0020] The high-temperature and high-pressure air is introduced into the precooler to exchange heat with the low-temperature molten salt from the low-temperature molten salt tank. The low-temperature molten salt becomes high-temperature molten salt and enters the high-temperature molten salt tank. The high-temperature and high-pressure air becomes medium-temperature and high-pressure air.

[0021] The medium-high temperature and high pressure air is introduced into the cooler to exchange heat with the medium-temperature and high pressure water from the medium-temperature water tank. The medium-high temperature and high pressure air is converted into low-temperature and high pressure air and stored in the air storage tank. The medium-temperature and high pressure water is converted into medium-high temperature and high pressure water. Part of it is stored in the hot water tank, and the other part is directly entered into the flash tank for flash evaporation. After flash evaporation, medium-temperature industrial steam and medium-temperature low-pressure water are generated;

[0022] The medium-temperature industrial steam is introduced into the steam generator through the steam tank, and heat exchanged with the high-temperature molten salt from the high-temperature molten salt tank. The medium-temperature industrial steam is converted into high-temperature industrial steam and supplied to the industrial park, and the high-temperature molten salt is converted into low-temperature molten salt and enters the low-temperature molten salt tank. At the same time, the medium-temperature industrial steam generates medium-temperature low-pressure water when passing through the steam tank, and the medium-temperature low-pressure water generated in the flash tank is pressurized by a pump and enters the medium-temperature water tank.

[0023] The energy release includes the following steps:

[0024] The low-temperature and high-pressure air in the gas storage tank is introduced into the heater to exchange heat with the low-temperature return water from the return water tank, and the low-temperature and high-pressure air is converted into medium-temperature and high-pressure air;

[0025] The medium-low-temperature and high-pressure air is introduced into the turbine for expansion to generate electricity, and the medium-low-temperature and high-pressure air is converted into air of normal temperature and pressure and discharged into the atmosphere.

[0026] Independent heating includes the following steps:

[0027] The medium-temperature, high-pressure water in the hot water tank is introduced into the flash tank for flash evaporation, and medium-temperature industrial steam and medium-temperature, low-pressure water are generated after flash evaporation;

[0028] The medium-temperature industrial steam is introduced into the steam generator through the steam tank, and heat exchanged with the high-temperature molten salt from the high-temperature molten salt tank. The medium-temperature industrial steam is converted into high-temperature industrial steam and supplied to the industrial park, and the high-temperature molten salt is converted into low-temperature molten salt and enters the low-temperature molten salt tank. At the same time, the medium-temperature industrial steam generates medium-temperature low-pressure water when passing through the steam tank, and the medium-temperature low-pressure water generated in the flash tank is pressurized by a pump and enters the medium-temperature water tank.

[0029] The temperature of high-temperature and high-pressure air is 260~310℃, and the pressure is 250~300 kPa, the temperature of medium-temperature and high-pressure air is 250~290℃, and the pressure is 250~300 kPa, the temperature of medium-temperature and high-pressure water is 180~200℃, and the pressure is 2800~4000kPa, the temperature of medium-temperature industrial steam is 180~200℃, the temperature of high-temperature industrial steam is 240~295℃, the temperature of medium-temperature and low-pressure water is 180~200, and the pressure is 1000~1600, and the temperature of medium-low-temperature return water is 50~90℃; the temperature of medium-low-temperature and high-pressure air is 30~80℃, and the pressure is 250~300 kPa, and the temperature of low-temperature and high-pressure air is less than 20℃, and the pressure is 250~300 kPa.

[0030] The cogeneration energy storage system and method for producing industrial steam of the present invention has the following advantages:

[0031] First, through the coordination of compressors, precoolers, coolers, gas storage tanks, low-temperature molten salt tanks, high-temperature molten salt tanks, medium-temperature water tanks and industrial steam supply components, the compression heat generated by the redundant electricity driven compressor during the low-power period can be used to heat the medium-temperature and high-pressure water, so that the medium-temperature and high-pressure water can be converted into high-temperature industrial steam, which can continuously supply high-temperature industrial steam to the industrial park, avoiding the relatively single energy conversion during the energy storage process and improving the energy utilization rate of the system.

[0032] Second, by using molten salt and water as heat storage media, medium-temperature steam is generated by flash evaporation of medium-temperature water after absorbing compression heat during the industrial steam supply stage, and the stored high-temperature molten salt is further used to heat it to a high-temperature state, thereby realizing the cascade storage and utilization of compression heat and further improving the energy utilization efficiency of the system.

[0033] Third, through the setting of the buffer tank, it can ensure that the system operates at a fixed operating condition during the energy release process, push the medium-temperature water into the cooler, push the medium-temperature, high-pressure water into the flash tank, maintain the constant pressure of the medium-temperature water tank and the hot water tank, and ensure the safe, stable and efficient operation of the system components. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0035] Figure 2 It is a schematic diagram of the energy storage stage process of the present invention;

[0036] Figure 3 It is a schematic diagram of the energy release stage process of the present invention;

[0037] Figure 4 It is a schematic diagram of the process of the independent heating stage of the present invention.

[0038] Reference numerals:

[0039] 1. Compressor; 2. Precooler; 3. Cooler; 4. Gas storage tank; 5. Heater; 6. Turbine; 7. Return water tank; 8. Flash tank; 9. Steam tank; 10. Hot water tank; 11. Pump; 12. Medium temperature water tank; 13. Buffer tank; 14. High temperature molten salt tank; 15. Low temperature molten salt tank; 16. Steam generator; 17. First control valve; 18. Second control valve; 19. Third control valve; 20. Fourth control valve; 21. Fifth control valve; 22. Sixth control valve; 23. Seventh control valve; 24. Eighth control valve; 25. Ninth control valve; 26. Tenth control valve; 27. Eleventh control valve; 28. Twelfth control valve; 29. ​​Thirteenth control valve. DETAILED DESCRIPTION

[0040] The technical solution in the present application will be described clearly and in detail below in conjunction with the accompanying drawings. Among them, in the description of the embodiments of the present application, unless otherwise specified, " / " means or, for example, A / B can mean A or B: "and / or" in the text is only a description of the association relationship of associated objects, indicating that there can be three relationships, such as A and / or B, which can mean: A exists alone, A and B exist at the same time, and B exists alone. In addition, in the description of the embodiments of the present application, "multiple" refers to two or more than two. The following terms "first" and "second" are used for descriptive purposes only and cannot be understood as implying or suggesting relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features.

[0041] like Figure 1As shown, the present invention provides a cogeneration energy storage system and method for producing industrial steam, including a compressor 1, a precooler 2, a cooler 3 and a gas storage tank 4, the inlet of the compressor 1 is used to introduce air at normal temperature and pressure, the outlet of the compressor 1 is connected to the first inlet of the precooler 2, the first outlet of the precooler 2 is connected to the first inlet of the cooler 3, the first outlet of the cooler 3 is connected to the gas storage tank 4, the second inlet of the precooler 2 is connected to the outlet of a low-temperature molten salt tank 15, the low-temperature molten salt tank 15 is used to store low-temperature molten salt, and the second outlet of the precooler 2 is connected to a high-temperature molten salt tank. The inlet of the tank 14, the high-temperature molten salt tank 14 is used to store high-temperature molten salt, the second inlet of the cooler 3 is connected to the outlet of the medium-temperature water tank 12, the medium-temperature water tank 12 stores medium-temperature high-pressure water, the outlet of the high-temperature molten salt tank 14 and the second outlet of the cooler 3 are connected to an industrial steam supply component, the industrial steam supply component is used to heat the medium-temperature high-pressure water through the compression heat generated by the compressor 1, so that the medium-temperature high-pressure water is converted into high-temperature industrial steam, and high-temperature industrial steam is continuously supplied to the industrial park, avoiding the relatively single energy conversion during the energy storage process, and improving the energy utilization rate of the system.

[0042] like Figure 1 As shown, the industrial steam supply assembly includes a flash tank 8, a steam tank 9 and a steam generator 16, the inlet of the flash tank 8 is connected to the second outlet of the cooler 3, the inlet of the steam tank 9 is connected to the first outlet of the flash tank 8, the first outlet of the steam tank 9 is connected to the first inlet of the steam generator 16, the first outlet of the steam generator 16 is used to supply high-temperature industrial steam to the industrial park, the second inlet of the steam generator 16 is connected to the outlet of the high-temperature molten salt tank 14, and the second outlet of the steam generator 16 is connected to the inlet of the low-temperature molten salt tank 15.

[0043] like Figure 1 As shown, a hot water tank 10 is arranged between the cooler 3 and the flash tank 8, the first channel of the hot water tank 10 is respectively connected to the second outlet of the cooler 3 and the inlet of the flash tank 8, the second passage of the hot water tank 10 is connected to the first passage of the buffer tank 13, the second passage of the buffer tank 13 is connected to the gas storage tank 4, the third passage of the buffer tank 13 is connected to the medium-temperature water tank 12, and is connected to the gas storage tank 4 through the buffer tank 13, so that the high-pressure air in the power generation process can be controlled to maintain a constant pressure to ensure the system operates under a fixed working condition.

[0044] like Figure 1 As shown, a pump 11 is provided between the medium-temperature water tank 12 and the flash tank 8 and the steam tank 9. The inlet of the pump 11 is connected to the second outlet of the flash tank 8 and the second outlet of the steam tank 9 respectively, and the outlet of the pump 11 is connected to the inlet of the medium-temperature water tank 12. The medium-temperature low-pressure water is pressurized by the pump 11 to become medium-temperature high-pressure water.

[0045] like Figure 1As shown, the outlet of the gas storage tank 4 is connected to the first inlet of the heater 5, the first outlet of the heater 5 is connected to the inlet of the turbine 6, the outlet of the turbine 6 is connected to the atmosphere, and the second inlet of the heater 5 is connected to the outlet of the return water tank 7, and the return water tank 7 is used to store medium and low temperature return water generated after the high-temperature industrial steam is utilized from the industrial park.

[0046] like Figure 1 As shown, a first control valve 17 is provided at the inlet of the compressor 1, a second control valve 18 is provided between the cooler 3 and the gas storage tank 4, a third control valve 19 is provided between the gas storage tank 4 and the heater 5, a fourth control valve 20 is provided on the first passage of the hot water tank 10, a ninth control valve 25 is provided between the hot water tank 10 and the buffer tank 13, a fifth control valve 21 is provided at the inlet of the flash tank 8, a sixth control valve 22 is provided between the flash tank 8 and the steam tank 9, a seventh control valve 23 is provided between the buffer tank 13 and the medium-temperature water tank 12, a tenth control valve 26 is provided between the buffer tank 13 and the gas storage tank 4, an eighth control valve 24 is provided between the medium-temperature water tank 12 and the cooler 3, an eleventh control valve 27 is provided between the precooler 2 and the high-temperature molten salt tank 14, a twelfth control valve 28 is provided between the steam generator 16 and the low-temperature molten salt tank 15, and a thirteenth control valve 29 is provided between the return water tank 7 and the heater 5.

[0047] like Figure 2 As shown, the present invention also provides a heat and power cogeneration energy storage method for producing industrial steam, including energy storage, energy release and independent heat supply, wherein the energy storage is used to convert the excess electric energy during the low electricity consumption into heat energy and compressed air for storage, and the heat energy is used to prepare industrial steam, the energy release is used to convert the stored high-pressure air into electric energy, and the independent heat supply is used to continue to prepare industrial steam using the stored surplus heat energy during the non-energy storage working stage, and the energy storage includes the following steps:

[0048] Introduce normal temperature and pressure air into compressor 1, and use the surplus electric energy during the low electricity consumption period to drive compressor 1 to work, so that the normal temperature and pressure air is converted into high temperature and high pressure air;

[0049] The high-temperature and high-pressure air is introduced into the precooler 2, and heat exchange is performed with the low-temperature molten salt from the low-temperature molten salt tank 15. The low-temperature molten salt is converted into high-temperature molten salt and enters the high-temperature molten salt tank 14, and the high-temperature and high-pressure air is converted into medium-temperature and high-pressure air;

[0050] The medium-high-temperature and high-pressure air is introduced into the cooler 3, and heat exchange is performed with the medium-temperature and high-pressure water from the medium-temperature water tank 12. The medium-high-temperature and high-pressure air is converted into low-temperature and high-pressure air and enters the air storage tank 4 for storage. The medium-temperature and high-pressure water is converted into medium-high-temperature and high-pressure water, a part of which enters the hot water tank 10 for storage, and the other part directly enters the flash tank 8 for flash evaporation. After flash evaporation, medium-temperature industrial steam and medium-temperature low-pressure water are generated;

[0051] The medium-temperature industrial steam is introduced into the steam generator 16 through the steam tank 9, and heat exchanged with the high-temperature molten salt from the high-temperature molten salt tank 14. The medium-temperature industrial steam is converted into high-temperature industrial steam and supplied to the industrial park, and the high-temperature molten salt is converted into low-temperature molten salt and enters the low-temperature molten salt tank 15. At the same time, the medium-temperature industrial steam generates medium-temperature low-pressure water when passing through the steam tank 9, and the medium-temperature low-pressure water generated in the flash tank 8 is pressurized by the pump 11 and enters the medium-temperature water tank 12.

[0052] like Figure 3 As shown, the energy release includes the following steps:

[0053] The low-temperature and high-pressure air in the air storage tank 4 is introduced into the heater 5, and heat exchange is performed with the low-temperature return water from the return water tank 7, and the low-temperature and high-pressure air is converted into medium-temperature and high-pressure air;

[0054] The medium-low-temperature and high-pressure air is introduced into the turbine for expansion to generate electricity, and the medium-low-temperature and high-pressure air is converted into air of normal temperature and pressure and discharged into the atmosphere.

[0055] like Figure 4 As shown, independent heating includes the following steps:

[0056] The medium-temperature, high-pressure water in the hot water tank 10 is introduced into the flash tank 8 for flash evaporation, and medium-temperature industrial steam and medium-temperature, low-pressure water are generated after flash evaporation;

[0057] The medium-temperature industrial steam is introduced into the steam generator 16 through the steam tank 9, and heat exchanged with the high-temperature molten salt from the high-temperature molten salt tank 14. The medium-temperature industrial steam is converted into high-temperature industrial steam and supplied to the industrial park, and the high-temperature molten salt is converted into low-temperature molten salt and enters the low-temperature molten salt tank 15. At the same time, the medium-temperature industrial steam generates medium-temperature low-pressure water when passing through the steam tank 9, and the medium-temperature low-pressure water generated in the flash tank 8 is pressurized by the pump 11 and enters the medium-temperature water tank 12.

[0058] The temperature of high-temperature and high-pressure air is 260~310℃, and the pressure is 250~300 kPa, the temperature of medium-temperature and high-pressure air is 250~290℃, and the pressure is 250~300 kPa, the temperature of medium-temperature and high-pressure water is 180~200℃, and the pressure is 2800~4000kPa, the temperature of medium-temperature industrial steam is 180~200℃, the temperature of high-temperature industrial steam is 240~295℃, the temperature of medium-temperature and low-pressure water is 180~200, and the pressure is 1000~1600, and the temperature of medium-low-temperature return water is 50~90℃; the temperature of medium-low-temperature and high-pressure air is 30~80℃, and the pressure is 250~300 kPa, and the temperature of low-temperature and high-pressure air is less than 20℃, and the pressure is 250~300 kPa.

[0059] Working principle:

[0060] When the user is in the low electricity consumption period, the fifth control valve 21, the sixth control valve 22, the seventh control valve 23, the eighth control valve 24, the ninth control valve 25, the tenth control valve 26, and the twelfth control valve 28 are closed, and the first control valve 17, the second control valve 18, the third control valve 19, the fourth control valve 20, the eleventh control valve 27, and the thirteenth control valve 29 are opened, so that the heat storage stage works, and the normal temperature and pressure air is introduced into the compressor 1, and the excess electric energy during the low electricity consumption period is used to drive the compressor 1 to work, so that the normal temperature and pressure air is changed into high temperature and high pressure air, and the high temperature and high pressure air enters the precooler 2, and heat exchanges with the low temperature molten salt from the low temperature molten salt tank 15, and the low temperature molten salt is changed into high temperature molten salt and enters the high temperature molten salt tank 14, and the high temperature and high pressure air is changed into medium-high temperature and high pressure air, and the medium-high temperature and high pressure air enters the cooler 3, and heat exchanges with the medium temperature and high pressure water from the medium temperature water tank 12, and the medium temperature and high pressure water is changed into medium-high temperature and high pressure water and enters the hot water tank 10 for storage, and the medium-high temperature and high pressure air is changed into low temperature and high pressure air and enters the gas storage tank 4 for storage.

[0061] When heating is provided alone, the first control valve 17, the second control valve 18, the third control valve 19, the eighth control valve 24, the tenth control valve 26, the eleventh control valve 27 and the thirteenth control valve are closed, and the fourth control valve 20, the fifth control valve 21, the sixth control valve 22, the seventh control valve 23, the ninth control valve 25 and the twelfth control valve 28 are opened to supply industrial steam for part of the work. The medium-temperature, high-pressure water in the hot water tank 10 enters the flash tank 8 for flash evaporation, so that a part of the medium-temperature, high-pressure water becomes medium-temperature industrial steam and the other part becomes medium-temperature, low-pressure water. Then, the medium-temperature industrial steam passes through the steam tank 9 and enters the steam generator 16 to exchange heat with the high-temperature molten salt from the high-temperature molten salt tank 14. The medium-temperature industrial steam becomes high-temperature industrial steam and is supplied to the industrial park. The high-temperature molten salt becomes low-temperature molten salt and enters the low-temperature molten salt tank 15. At the same time, the medium-temperature, low-pressure water generated by the steam tank 9 and the medium-temperature, low-pressure water generated in the flash tank 8 are pressurized by the pump 11 and enter the medium-temperature water tank 12.

[0062] When the independent heating stage and the heat storage stage are carried out simultaneously, the fifth control valve 21 and the eighth control valve 24 are opened, and part of the medium-high temperature and high-pressure water enters the hot water tank 10 for storage, and the other part enters the flash tank 8 for flash evaporation, so that part of the medium-high temperature and high-pressure water becomes medium-temperature industrial steam and the other part becomes medium-temperature low-pressure water. Then the medium-temperature industrial steam enters the steam generator 16 through the steam tank 9, and exchanges heat with the high-temperature molten salt from the high-temperature molten salt tank 14. The medium-temperature industrial steam becomes high-temperature industrial steam and is supplied to the industrial park, and the high-temperature molten salt becomes low-temperature molten salt and enters the low-temperature molten salt tank 15. At the same time, the medium-temperature and low-pressure water generated by the steam tank 9 and the medium-temperature and low-pressure water generated in the flash tank 8 are pressurized by the pump 11 and enter the medium-temperature water tank 12.

[0063] When the user is at the peak of electricity consumption, the third control valve 19 is opened and the remaining twelve control valves are closed to allow the energy release part to work; the high-pressure air in the air storage tank 4 enters the heater 5 and exchanges heat with the medium and low temperature return water flowing out of the return water tank 7, and the low-temperature high-pressure air becomes medium and low temperature high-pressure air, and then the medium and low temperature high-pressure air enters the turbine for expansion to generate electricity, and the medium and low temperature high-pressure air becomes normal temperature and pressure air discharged into the atmosphere, and the medium and low temperature return water becomes low-temperature return water discharged into the environment.

[0064] When the independent heating stage and the energy release stage are running at the same time, the tenth control valve 26 is opened to connect the buffer tank 13 with the gas storage tank 4, so that the high-pressure air in the power generation process can be controlled to maintain a constant pressure, ensuring the system to operate at a constant condition. At the same time, the medium-high temperature and high-pressure water in the hot water tank 10 is pushed into the flash tank 8 for flash evaporation. The above steps are repeated to complete the supply of industrial steam.

[0065] Wherein, in the above steps, the air working pressure range is 101.3 kPa-4 MPa, and the molten salt working temperature range is 180°C-400°C.

[0066] The cogeneration energy storage system and method for producing industrial steam of the present invention has the following advantages:

[0067] First, through the coordination of compressors, precoolers, coolers, gas storage tanks, low-temperature molten salt tanks, high-temperature molten salt tanks, medium-temperature water tanks and industrial steam supply components, the compression heat generated by the redundant electricity driven compressor during the low-power period can be used to heat the medium-temperature and high-pressure water, so that the medium-temperature and high-pressure water can be converted into high-temperature industrial steam, which can continuously supply high-temperature industrial steam to the industrial park, avoiding the relatively single energy conversion during the energy storage process and improving the energy utilization rate of the system.

[0068] Second, by using molten salt and water as heat storage media, medium-temperature steam is generated by flash evaporation of medium-temperature water after absorbing compression heat during the industrial steam supply stage, and the stored high-temperature molten salt is further used to heat it to a high-temperature state, thereby realizing the cascade storage and utilization of compression heat and further improving the energy utilization efficiency of the system.

[0069] Third, through the setting of the buffer tank, it can ensure that the system operates at a fixed operating condition during the energy release process, push the medium-temperature water into the cooler, push the medium-temperature, high-pressure water into the flash tank, maintain the constant pressure of the medium-temperature water tank and the hot water tank, and ensure the safe, stable and efficient operation of the system components.

[0070] It is to be understood that the present invention is described by some embodiments, and it is known to those skilled in the art that various changes or equivalent substitutions may be made to these features and embodiments without departing from the spirit and scope of the present invention. In addition, under the teachings of the present invention, these features and embodiments may be modified to adapt to specific circumstances and materials without departing from the spirit and scope of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application are within the scope of protection of the present invention.

Claims

1. A heat and power cogeneration energy storage system for producing industrial steam, comprising a compressor (1), a precooler (2), a cooler (3) and a gas storage tank (4), wherein the inlet of the compressor (1) is used to introduce air at normal temperature and pressure, the outlet of the compressor (1) is connected to the first inlet of the precooler (2), the first outlet of the precooler (2) is connected to the first inlet of the cooler (3), and the first outlet of the cooler (3) is connected to the gas storage tank (4), characterized in that: Also includes: A low-temperature molten salt tank (15), the outlet of which is connected to the second inlet of the precooler (2), and the low-temperature molten salt tank (15) is used to store low-temperature molten salt; A high-temperature molten salt tank (14), the inlet of which is connected to the second outlet of the precooler (2), and the high-temperature molten salt tank (14) is used to store high-temperature molten salt; A medium-temperature water tank (12), the outlet of which is connected to the second inlet of the cooler (3), wherein medium-temperature high-pressure water is stored in the medium-temperature water tank (12); An industrial steam supply component is connected to the outlet of the high-temperature molten salt tank (14) and the second outlet of the cooler (3) respectively, and is used to heat the medium-temperature high-pressure water by compression heat generated by the compressor (1), so that the medium-temperature high-pressure water is converted into high-temperature industrial steam; The industrial steam supply assembly comprises a flash tank (8), a steam tank (9) and a steam generator (16); the inlet of the flash tank (8) is connected to the second outlet of the cooler (3); the inlet of the steam tank (9) is connected to the first outlet of the flash tank (8); the first outlet of the steam tank (9) is connected to the first inlet of the steam generator (16); the first outlet of the steam generator (16) is used to supply high-temperature industrial steam to the industrial park; the second inlet of the steam generator (16) is connected to the outlet of the high-temperature molten salt tank (14); and the second outlet of the steam generator (16) is connected to the inlet of the low-temperature molten salt tank (15); A hot water tank (10) is provided between the cooler (3) and the flash tank (8); a first passage of the hot water tank (10) is connected to a second outlet of the cooler (3) and an inlet of the flash tank (8), respectively; a second passage of the hot water tank (10) is connected to a first passage of a buffer tank (13); a second passage of the buffer tank (13) is connected to a gas storage tank (4); and a third passage of the buffer tank (13) is connected to a medium-temperature water tank (12); A pump (11) is provided between the medium-temperature water tank (12), the flash tank (8) and the steam tank (9); the inlet of the pump (11) is connected to the second outlet of the flash tank (8) and the second outlet of the steam tank (9), respectively, and the outlet of the pump (11) is connected to the inlet of the medium-temperature water tank (12); The outlet of the gas storage tank (4) is connected to the first inlet of the heater (5), the first outlet of the heater (5) is connected to the inlet of the turbine (6), the outlet of the turbine (6) is connected to the atmosphere, and the second inlet of the heater (5) is connected to the outlet of the return water tank (7).

2. The cogeneration energy storage system for producing industrial steam according to claim 1, characterized in that: A first control valve (17) is provided at the inlet of the compressor (1), a second control valve (18) is provided between the cooler (3) and the gas storage tank (4), a third control valve (19) is provided between the gas storage tank (4) and the heater (5), a fourth control valve (20) is provided on the first passage of the hot water tank (10), a ninth control valve (25) is provided between the hot water tank (10) and the buffer tank (13), a fifth control valve (21) is provided at the inlet of the flash tank (8), and a sixth control valve (22) is provided between the flash tank (8) and the steam tank (9), A seventh control valve (23) is provided between the buffer tank (13) and the medium-temperature water tank (12), a tenth control valve (26) is provided between the buffer tank (13) and the gas storage tank (4), an eighth control valve (24) is provided between the medium-temperature water tank (12) and the cooler (3), an eleventh control valve (27) is provided between the precooler (2) and the high-temperature molten salt tank (14), a twelfth control valve (28) is provided between the steam generator (16) and the low-temperature molten salt tank (15), and a thirteenth control valve (29) is provided between the return water tank (7) and the heater (5).

3. A cogeneration energy storage method for producing industrial steam, characterized in that: The cogeneration energy storage system for producing industrial steam as claimed in claim 2 includes energy storage, energy release and independent heat supply. The energy storage is used to convert the excess electric energy during the low electricity consumption into heat energy and compressed air for storage, and the heat energy is used to prepare industrial steam. The energy release is used to convert the stored high-pressure air into electric energy. The independent heat supply is used to continue to prepare industrial steam using the stored surplus heat energy during the non-energy storage working stage. The energy storage includes the following steps: Introducing normal temperature and normal pressure air into a compressor (1), using surplus electric energy during a low electricity consumption period to drive the compressor (1) to operate, thereby converting the normal temperature and normal pressure air into high temperature and high pressure air; Introducing high-temperature and high-pressure air into the precooler (2) to perform heat exchange with the low-temperature molten salt from the low-temperature molten salt tank (15), the low-temperature molten salt is converted into high-temperature molten salt and enters the high-temperature molten salt tank (14), and the high-temperature and high-pressure air is converted into medium-temperature and high-pressure air; The medium-high temperature and high pressure air is introduced into the cooler (3) to perform heat exchange with the medium-temperature and high pressure water from the medium-temperature water tank (12). The medium-high temperature and high pressure air is converted into low-temperature and high pressure air and enters the air storage tank (4) for storage. The medium-temperature and high pressure water is converted into medium-high temperature and high pressure water, a portion of which enters the hot water tank (10) for storage, and the other portion directly enters the flash tank (8) for flash evaporation. After flash evaporation, medium-temperature industrial steam and medium-temperature and low-pressure water are generated. The medium-temperature industrial steam is introduced into the steam generator (16) through the steam tank (9) to exchange heat with the high-temperature molten salt from the high-temperature molten salt tank (14). The medium-temperature industrial steam is converted into high-temperature industrial steam and supplied to the industrial park. The high-temperature molten salt is converted into low-temperature molten salt and enters the low-temperature molten salt tank (15). At the same time, the medium-temperature industrial steam generates medium-temperature low-pressure water when passing through the steam tank (9). The medium-temperature low-pressure water and the medium-temperature low-pressure water generated in the flash tank (8) are pressurized by the pump (11) and then enter the medium-temperature water tank (12); The energy release comprises the following steps: The low-temperature and high-pressure air in the air storage tank (4) is introduced into the heater (5) to exchange heat with the low-temperature return water from the return water tank (7), so that the low-temperature and high-pressure air is converted into medium-temperature and high-pressure air; The medium-low-temperature and high-pressure air is introduced into the turbine for expansion to generate electricity, and the medium-low-temperature and high-pressure air is converted into normal-temperature and normal-pressure air and discharged into the atmosphere; The independent heating comprises the following steps: The medium-temperature, high-pressure water in the hot water tank (10) is introduced into the flash tank (8) for flash evaporation, and after the flash evaporation, medium-temperature industrial steam and medium-temperature, low-pressure water are generated; The medium-temperature industrial steam is introduced into the steam generator (16) through the steam tank (9) to exchange heat with the high-temperature molten salt from the high-temperature molten salt tank (14). The medium-temperature industrial steam is converted into high-temperature industrial steam and supplied to the industrial park, and the high-temperature molten salt is converted into low-temperature molten salt and enters the low-temperature molten salt tank (15). At the same time, the medium-temperature industrial steam generates medium-temperature low-pressure water when passing through the steam tank (9). The medium-temperature low-pressure water and the medium-temperature low-pressure water generated in the flash tank (8) are pressurized by the pump (11) and then enter the medium-temperature water tank (12).

4. The cogeneration energy storage method for producing industrial steam according to claim 3, characterized in that: The temperature of the high-temperature and high-pressure air is 260~310℃, and the pressure is 250~300 kPa, the temperature of the medium-temperature and high-pressure air is 250~290℃, and the pressure is 250~300 kPa, the temperature of the medium-temperature and high-pressure water is 180~200℃, and the pressure is 2800~4000kPa, the temperature of the medium-temperature industrial steam is 180~200℃, the temperature of the high-temperature industrial steam is 240~295℃, the temperature of the medium-temperature and low-pressure water is 180~200, and the pressure is 1000~1600, and the temperature of the medium-low temperature return water is 50~90℃; the temperature of the medium-low temperature and high-pressure air is 30~80℃, and the pressure is 250~300kPa, and the temperature of the low-temperature and high-pressure air is less than 20℃, and the pressure is 250~300kPa.

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