Heat energy storage system integrating industrial waste heat and operation method of heat energy storage system

Abstract

The invention discloses a heat energy storage system integrating industrial waste heat and an operation method of the heat energy storage system, and relates to the technical field of industrial waste heat utilization and wind power energy storage. The system comprises an industrial waste heat utilization system, a high-temperature heat pump energy storage system and a high-temperature heat pump energy release system. When wind power is in a low ebb, the industrial waste heat utilization system converts heat energy in industrial flue gas into heat energy of a heat storage medium; when wind power is in a peak, redundant electric energy and heat energy in a heat storage medium are input into the high-temperature heat pump energy storage system through a working medium, and finally the electric energy and the heat energy of the heat storage medium are converted into heat energy of high-temperature fused salt; in the peak period of power utilization, the high-temperature heat pump energy release system generates electric energy through heat of the high-temperature fused salt, and the load requirement of a power grid is met. According to the system, efficient utilization of energy can be achieved, the problem that fluctuation is large during wind energy grid connection is solved, and the system is an effective method for utilizing industrial waste heat and absorbing renewable energy source electric power.

Description

Technical Field

[0001] The present invention relates to the technical field of industrial waste heat utilization and wind power energy storage, and in particular to a thermal energy storage system integrating industrial waste heat and an operation method thereof. Background Art

[0002] As a clean energy, wind power generation has received extensive attention and application in recent years. However, the uneven temporal and spatial distribution of wind energy resources, the instability and intermittency of wind speed make the wind power generation fluctuate greatly, which poses a challenge to the stability and reliability of the power grid. A large-scale and long-term peak-shaving technology is urgently needed to ensure the safety of the power grid. Energy storage technology can realize energy transfer in the time dimension and balance the supply and demand of electricity. Among them, heat pump energy storage has high energy conversion efficiency and low operating cost, especially in the recovery of low-temperature waste heat. The effective combination of heat pump energy storage and wind energy can improve the flexibility and sustainability of the overall energy system under the condition of large energy fluctuations. Industrial waste heat is the heat that is not effectively utilized in the industrial production process. The utilization of industrial waste heat can not only improve energy utilization efficiency, but also help reduce energy consumption and environmental pollution. However, in actual applications, it faces the problem of low waste heat utilization temperature. The high-temperature heat pump system can combine industrial waste heat and wind power storage, and can realize the recovery and utilization of industrial waste heat while absorbing wind power resources. However, there is currently a lack of design and operation control methods for the configuration of thermal energy storage systems integrating industrial waste heat. Summary of the invention

[0003] In order to solve the problems existing in the above-mentioned prior art, the purpose of the present invention is to provide a thermal energy storage system integrating industrial waste heat and an operation method thereof, which can realize the integrated utilization of industrial waste heat.

[0004] In order to achieve the above object, the present invention adopts the following technical solution:

[0005] A thermal energy storage system integrating industrial waste heat, comprising an industrial waste heat utilization system, a high-temperature heat pump energy storage system, and a high-temperature heat pump energy release system; wherein:

[0006] The industrial waste heat utilization system comprises a high-temperature water tank 1, a low-temperature water tank 2, a first water pump 3 and a flue gas-water heat exchanger 19; wherein the low-temperature water in the low-temperature water tank 2 passes through the first water pump 3 and absorbs waste heat from the industrial flue gas 22 in the flue gas-water heat exchanger 19, and then generates high-temperature water and enters the high-temperature water tank 1 for storage;

[0007] The high-temperature heat pump energy storage system includes a high-temperature water tank 1, a low-temperature water tank 2, a No. 2 water pump 4, a high-temperature molten salt storage tank 5, a low-temperature molten salt storage tank 6, a No. 1 molten salt pump 7, a working fluid-water heat exchanger 9, a No. 1 working fluid-working fluid heat exchanger 10, a heat pump charging compressor 11, a No. 1 working fluid-molten salt heat exchanger 12, a heat pump charging expander 13 and a wind power generator set 20; wherein the wind power generator set 20 inputs electrical energy to drive the heat pump charging compressor 11 to work; the low-temperature and low-pressure working fluid absorbs heat in the working fluid-water heat exchanger 9 to produce a normal-temperature and low-pressure working fluid, and then enters the No. 1 working fluid-working fluid heat exchanger 10 to absorb heat, and the medium-temperature and low-pressure working fluid at the outlet of the No. 1 working fluid-working fluid heat exchanger 10 is compressed by the heat pump charging compressor After the machine 11, a high-temperature and high-pressure working fluid is generated, and then enters the No. 1 working fluid-molten salt heat exchanger 12 to release heat. The medium-temperature and high-pressure working fluid at the outlet of the No. 1 working fluid-molten salt heat exchanger 12 enters the No. 1 working fluid-working fluid heat exchanger 10 to release heat, and the normal-temperature and high-pressure working fluid generated enters the heat pump charging expander 13 to do work, and finally returns to the low-temperature and low-pressure working fluid to enter the working fluid-water heat exchanger 9, and repeats this process; at the same time, the high-temperature water in the high-temperature water tank 1 passes through the No. 2 water pump 4, releases heat in the working fluid-water heat exchanger 9, and then enters the low-temperature water tank 2 to form low-temperature water; the low-temperature molten salt in the low-temperature molten salt storage tank 6 passes through the No. 1 molten salt pump 7, absorbs heat in the No. 1 working fluid-molten salt heat exchanger 12, and then enters the high-temperature molten salt storage tank 5 to form high-temperature molten salt;

[0008] The high-temperature heat pump energy release system includes a high-temperature molten salt storage tank 5, a low-temperature molten salt storage tank 6, a No. 2 molten salt pump 8, a No. 2 working fluid-molten salt heat exchanger 14, a heat pump discharge expander 15, a No. 2 working fluid-working fluid heat exchanger 16, a working fluid-seawater heat exchanger 17, a heat pump discharge compressor 18 and a high-temperature heat pump generator 21; wherein, the low-temperature and low-pressure working fluid generates a normal-temperature and high-pressure working fluid after passing through the heat pump discharge compressor 18, and then enters the No. 2 working fluid-working fluid heat exchanger 16 to absorb heat, and the medium-temperature and high-pressure working fluid at the outlet of the No. 2 working fluid-working fluid heat exchanger 16 enters the No. 2 working fluid-molten salt heat exchanger 14 to absorb heat to generate a high-temperature and high-pressure working fluid, and then enters the heat pump discharge compressor 18. The expander 15 performs work, driving the high-temperature heat pump generator 21 to generate electricity, which is output to the power grid. The medium-temperature and low-pressure working fluid at the outlet of the heat pump discharge expander 15 enters the No. 2 working fluid-working fluid heat exchanger 16 to release heat and produce a normal-temperature and low-pressure working fluid, and then enters the working fluid-seawater heat exchanger 17 to release heat, and finally returns to the low-temperature and low-pressure working fluid to enter the heat pump discharge compressor 18, and repeats this process; wherein, the high-temperature molten salt in the high-temperature molten salt storage tank 5 passes through the No. 2 molten salt pump 8, releases heat in the No. 2 working fluid-molten salt heat exchanger 14, and then enters the low-temperature molten salt storage tank 6 to form a low-temperature molten salt, and the low-temperature seawater 23 enters the working fluid-seawater heat exchanger 17 to absorb heat and evaporate to form water vapor.

[0009] Furthermore, both the high-temperature water tank 1 and the low-temperature water tank 2 use normal pressure water as the heat storage medium, the pressure range is 0.6-0.9 MPa, the operating temperature range of the high-temperature water tank 1 is 130-150°C, and the operating temperature range of the low-temperature water tank 2 is 30-50°C; the high-temperature molten salt storage tank 5 and the low-temperature molten salt storage tank 6 both use ternary molten salt Hitec salt as the heat storage medium, the operating temperature range of the high-temperature molten salt storage tank 5 is 420-440°C, and the operating temperature range of the low-temperature molten salt storage tank 6 is 290-310°C.

[0010] Furthermore, the circulating working fluid used in the high-temperature heat pump energy storage system and the high-temperature heat pump energy release system is air, and the circulation form adopts the Brayton cycle. The maximum working temperature is 450°C and the minimum working temperature is 20°C.

[0011] Furthermore, the heat pump charging compressor 11 and the heat pump discharging compressor 18 are composed of at least a four-stage compressor, using a centrifugal compressor, and the comprehensive inlet and outlet pressure ratio reaches 6.9; the heat pump charging expander 13 and the heat pump discharging expander 15 are composed of at least a three-stage expansion machine, using an axial flow expander, and the comprehensive inlet and outlet expansion ratio reaches 5.8.

[0012] Furthermore, the working fluid-water heat exchanger 9, the No. 1 working fluid-working fluid heat exchanger 10, the No. 2 working fluid-working fluid heat exchanger 16, the No. 1 working fluid-molten salt heat exchanger 12, the No. 2 working fluid-molten salt heat exchanger 14 and the flue gas-water heat exchanger 19 all adopt shell and tube heat exchangers, and the working fluid-seawater heat exchanger 17 adopts a plate heat exchanger.

[0013] Furthermore, the high-temperature water tank 1 and the low-temperature water tank 2 are pressure water tanks, including an inlet and an outlet; the high-temperature molten salt storage tank 5 and the low-temperature molten salt storage tank 6 include an inlet and an outlet.

[0014] Furthermore, the heat pump charging compressor 11 and the heat pump charging expander 13 are both coaxially connected to the wind power generator set 20; the heat pump discharging expander 15 and the heat pump discharging compressor 18 are both coaxially connected to the high-temperature heat pump generator 21.

[0015] The thermal energy storage system integrating industrial waste heat and the operation method thereof,

[0016] 1) When the wind power generator set 20 is at a low point, the industrial waste heat utilization system starts to work, and the industrial flue gas 22 is used as the heat source of the high-temperature water tank 1. The industrial waste heat utilization system converts the heat energy in the industrial flue gas 22 into the heat energy in the high-temperature water tank 1; specifically, the low-temperature water in the low-temperature water tank 2 absorbs the heat of the industrial flue gas in the flue gas-water heat exchanger 19 after passing through the No. 1 water pump 3, and is finally stored in the high-temperature water tank 1;

[0017] 2) When the wind power generator set 20 is at its peak, the high-temperature heat pump energy storage system starts to work, and the electric energy output by the wind power generator set 20 is used as the input source of the heat pump charging compressor 11. The high-temperature heat pump energy storage system is used to convert the electric energy and the heat energy in the high-temperature water tank 1 into the heat energy stored in the high-temperature molten salt storage tank 5; specifically, the working fluid absorbs the heat energy in the high-temperature water in the working fluid-water heat exchanger 9, and then absorbs heat in the No. 1 working fluid-working fluid heat exchanger 10 and enters the heat pump charging compressor 11 for pressurization, and then releases heat to the low-temperature molten salt in the No. 1 working fluid-molten salt heat exchanger 12, and finally stores the electric energy and the heat energy in the high-temperature water in the high-temperature molten salt storage tank 5;

[0018] 3) When the power grid is at its peak of electricity consumption, the high-temperature heat pump energy release system starts to work, and the heat energy in the high-temperature molten salt storage tank 5 is used as the heat source of the working fluid. The high-temperature heat pump energy release system is used to convert the heat energy in the high-temperature molten salt storage tank 5 into electrical energy and thermal energy in seawater; specifically, the working fluid enters the No. 2 working fluid-working fluid heat exchanger 16 to absorb heat after being pressurized in the heat pump discharge compressor 18, and then enters the No. 2 working fluid-molten salt heat exchanger 14 to absorb the thermal energy of the high-temperature molten salt, and then enters the heat pump discharge expander 15 to do work, and is converted into electrical energy in the high-temperature heat pump generator 21 and output to the power grid. The seawater absorbs heat and evaporates in the working fluid-seawater heat exchanger 17, and finally the thermal energy in the high-temperature molten salt is converted into electrical energy and thermal energy in seawater.

[0019] Compared with the prior art, the present invention has the following advantages:

[0020] (1) The industrial waste heat utilization system can realize the integrated utilization of industrial waste heat, save primary energy, improve economic benefits and reduce pollution;

[0021] (2) The high-temperature heat pump energy storage system can absorb excess wind power resources and store the heat energy in low-temperature water into high-temperature molten salt to achieve value-added heat storage;

[0022] (3) The high-temperature heat pump energy release system can output electricity during the peak power consumption of the power grid and provide heat for seawater desalination, which has higher technical and economic efficiency;

[0023] (4) The working fluids used include air and water, which have the advantages of high safety and good economy compared with other working fluids. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic diagram of a thermal energy storage system integrating industrial waste heat and an operation method thereof according to the present invention. DETAILED DESCRIPTION

[0025] The present invention is further described in detail below in conjunction with the accompanying drawings and specific implementation methods. It should be understood that the preferred implementation examples described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0026] like Figure 1 As shown, the present invention provides a thermal energy storage system integrating industrial waste heat and an operation method thereof, wherein the energy storage system comprises an industrial waste heat utilization system, a high-temperature heat pump energy storage system, and a high-temperature heat pump energy release system; wherein,

[0027] The industrial waste heat utilization system comprises a high-temperature water tank 1, a low-temperature water tank 2, a first water pump 3 and a flue gas-water heat exchanger 19; wherein the low-temperature water in the low-temperature water tank 2 passes through the first water pump 3 and absorbs waste heat from the industrial flue gas 22 in the flue gas-water heat exchanger 19, and then generates high-temperature water and enters the high-temperature water tank 1 for storage;

[0028] The high-temperature heat pump energy storage system includes a high-temperature water tank 1, a low-temperature water tank 2, a No. 2 water pump 4, a high-temperature molten salt storage tank 5, a low-temperature molten salt storage tank 6, a No. 1 molten salt pump 7, a working fluid-water heat exchanger 9, a No. 1 working fluid-working fluid heat exchanger 10, a heat pump charging compressor 11, a No. 1 working fluid-molten salt heat exchanger 12, a heat pump charging expander 13 and a wind power generator set 20; wherein the wind power generator set 20 inputs electrical energy to drive the heat pump charging compressor 11 to work; the low-temperature and low-pressure working fluid absorbs heat in the working fluid-water heat exchanger 9 to produce a normal-temperature and low-pressure working fluid, and then enters the No. 1 working fluid-working fluid heat exchanger 10 to absorb heat, and the medium-temperature and low-pressure working fluid at the outlet of the No. 1 working fluid-working fluid heat exchanger 10 is compressed by the heat pump charging compressor After the machine 11, a high-temperature and high-pressure working fluid is generated, and then enters the No. 1 working fluid-molten salt heat exchanger 12 to release heat. The medium-temperature and high-pressure working fluid at the outlet of the No. 1 working fluid-molten salt heat exchanger 12 enters the No. 1 working fluid-working fluid heat exchanger 10 to release heat, and the normal-temperature and high-pressure working fluid generated enters the heat pump charging expander 13 to do work, and finally returns to the low-temperature and low-pressure working fluid to enter the working fluid-water heat exchanger 9, and repeats this process; at the same time, the high-temperature water in the high-temperature water tank 1 passes through the No. 2 water pump 4, releases heat in the working fluid-water heat exchanger 9, and then enters the low-temperature water tank 2 to form low-temperature water, and the low-temperature molten salt in the low-temperature molten salt storage tank 6 passes through the No. 1 molten salt pump 7, absorbs heat in the No. 1 working fluid-molten salt heat exchanger 12, and then enters the high-temperature molten salt storage tank 5 to form high-temperature molten salt;

[0029] The high-temperature heat pump energy release system includes a high-temperature molten salt storage tank 5, a low-temperature molten salt storage tank 6, a No. 2 molten salt pump 8, a No. 2 working fluid-molten salt heat exchanger 14, a heat pump discharge expander 15, a No. 2 working fluid-working fluid heat exchanger 16, a working fluid-seawater heat exchanger 17, a heat pump discharge compressor 18 and a high-temperature heat pump generator 21; wherein, the low-temperature and low-pressure working fluid generates a normal-temperature and high-pressure working fluid after passing through the heat pump discharge compressor 18, and then enters the No. 2 working fluid-working fluid heat exchanger 16 to absorb heat, and the medium-temperature and high-pressure working fluid at the outlet of the No. 2 working fluid-working fluid heat exchanger 1 enters the No. 2 working fluid-molten salt heat exchanger 14 to absorb heat to generate a high-temperature and high-pressure working fluid, and then enters the heat pump discharge expander The expander 15 performs work, driving the high-temperature heat pump generator 21 to work and generate electricity, which is output to the power grid. The medium-temperature and low-pressure working fluid at the outlet of the heat pump discharge expander 15 enters the No. 2 working fluid-working fluid heat exchanger 16 to release heat and produce a normal-temperature and low-pressure working fluid, and then enters the working fluid-seawater heat exchanger 17 to release heat, and finally returns to the low-temperature and low-pressure working fluid to enter the heat pump discharge compressor 18, and repeats this process; wherein, the high-temperature molten salt in the high-temperature molten salt storage tank 5 passes through the No. 2 molten salt pump 8, releases heat in the No. 2 working fluid-molten salt heat exchanger 14, and then enters the low-temperature molten salt storage tank 6 to form a low-temperature molten salt, and the low-temperature seawater 23 enters the working fluid-seawater heat exchanger 17 to absorb heat and evaporate to form water vapor.

[0030] Furthermore, both the high-temperature water tank 1 and the low-temperature water tank 2 use normal pressure water as the heat storage medium, the pressure range is 0.6-0.9 MPa, the operating temperature range of the high-temperature water tank 1 is 130-150°C, and the operating temperature range of the low-temperature water tank 2 is 30-50°C; the high-temperature molten salt storage tank 5 and the low-temperature molten salt storage tank 6 both use ternary molten salt Hitec salt as the heat storage medium, the operating temperature range of the high-temperature molten salt storage tank 5 is 420-440°C, and the operating temperature range of the low-temperature molten salt storage tank 6 is 290-310°C. In this way, the potential of sensible heat storage can be fully utilized, the energy storage density can be improved, and the working temperature range can be expanded, which improves the efficiency of the energy storage system.

[0031] Furthermore, the circulating medium used by the high-temperature heat pump energy storage system and the high-temperature heat pump energy release system is air, and the circulation form adopts the Brayton cycle, with a maximum operating temperature of 450°C and a minimum operating temperature of 20°C. This allows the heat exchange temperature range between the high-temperature heat pump energy storage system and the high-temperature heat pump energy release system to match, reduce the heat loss of the heat exchanger, and ensure the efficient and economical operation of the system.

[0032] Furthermore, the heat pump charging compressor 11 and the heat pump discharging compressor 18 are composed of at least four-stage compressors, using centrifugal compressors, and the inlet and outlet comprehensive pressure ratio is 6.9; the heat pump charging expander 13 and the heat pump discharging expander 15 are composed of at least three-stage expanders, using axial flow expanders, and the inlet and outlet comprehensive expansion ratio is 5.8. In this way, the steam turbine equipment can be arranged more reasonably, reducing the economic cost of the system.

[0033] Furthermore, the working fluid-water heat exchanger 9, the first working fluid-working fluid heat exchanger 10, the second working fluid-working fluid heat exchanger 16, the first working fluid-molten salt heat exchanger 12, the second working fluid-molten salt heat exchanger 14 and the flue gas-water heat exchanger 19 all use shell and tube heat exchangers, and the working fluid-seawater heat exchanger 17 uses a plate heat exchanger. This can improve the heat exchange efficiency, reduce the floor space, and ensure the high efficiency and economy of the system.

[0034] Furthermore, the high-temperature water tank 1 and the low-temperature water tank 2 are pressure water tanks, which need to include an inlet and an outlet; the high-temperature molten salt storage tank 5 and the low-temperature molten salt storage tank 6 need to include an inlet and an outlet. In this way, the temperature and pressure of the storage tanks can be stabilized during heat charging and heat discharge, ensuring the high efficiency of the heat charging and heat discharge process.

[0035] Furthermore, the heat pump charging compressor 11 and the heat pump charging expander 13 are both coaxially connected to the wind power generator set 20; the heat pump discharging expander 15 and the heat pump discharging compressor 18 are both coaxially connected to the high-temperature heat pump generator 21. This can ensure the same frequency operation of the equipment, reduce unnecessary equipment investment, reduce system losses, and ensure the technical and economic efficiency of the system.

[0036] The high-temperature heat pump energy storage system integrating industrial waste heat and the operation method thereof,

[0037] 1) When the wind power generator set 20 is at a low point, the industrial waste heat utilization system starts to work, and the industrial flue gas 22 is used as the heat source of the high-temperature water tank 1. The industrial waste heat utilization system converts the heat energy in the industrial flue gas 22 into the heat energy in the high-temperature water tank 1; specifically, the low-temperature water in the low-temperature water tank 2 absorbs the heat of the industrial flue gas in the flue gas-water heat exchanger 19 after passing through the No. 1 water pump 3, and is finally stored in the high-temperature water tank 1;

[0038] 2) When the wind power generator set 20 is at its peak, the high-temperature heat pump energy storage system starts to work, and the electric energy output by the wind power generator set 20 is used as the input source of the heat pump charging compressor 11. The high-temperature heat pump energy storage system is used to convert the electric energy and the heat energy in the high-temperature water tank 1 into the heat energy stored in the high-temperature molten salt storage tank 5; specifically, the working fluid absorbs the heat energy in the high-temperature water in the working fluid-water heat exchanger 9, and then absorbs heat in the No. 1 working fluid-working fluid heat exchanger 10 and enters the heat pump charging compressor 11 for pressurization, and then releases heat to the low-temperature molten salt in the No. 1 working fluid-molten salt heat exchanger 12, and finally stores the electric energy and the heat energy in the high-temperature water in the high-temperature molten salt storage tank 5;

[0039] 3) When the power grid is at its peak of electricity consumption, the high-temperature heat pump energy release system starts to work, and the heat energy in the high-temperature molten salt storage tank 5 is used as the heat source of the working fluid. The high-temperature heat pump energy release system is used to convert the heat energy in the high-temperature molten salt storage tank 5 into electrical energy and thermal energy in seawater; specifically, the working fluid enters the No. 2 working fluid-working fluid heat exchanger 16 to absorb heat after being pressurized in the heat pump discharge compressor 18, and then enters the No. 2 working fluid-molten salt heat exchanger 14 to absorb the thermal energy of the high-temperature molten salt, and then enters the heat pump discharge expander 15 to do work, and is converted into electrical energy in the high-temperature heat pump generator 21 and output to the power grid. The seawater absorbs heat and evaporates in the working fluid-seawater heat exchanger 17, and finally the thermal energy in the high-temperature molten salt is converted into electrical energy and thermal energy in seawater.

[0040] When wind power is at a low point, the industrial waste heat utilization system converts the heat energy in industrial flue gas into the heat energy of the heat storage medium; when wind power is at a peak, the excess electricity and the heat energy in the heat storage medium are input into the high-temperature heat pump energy storage system through the working fluid, and finally the electricity and the heat energy of the heat storage medium are converted into the heat energy of high-temperature molten salt; when electricity consumption is at a peak, the high-temperature heat pump energy release system uses the heat of the high-temperature molten salt to generate electricity to meet the load demand of the power grid. The system of the present invention can realize the efficient utilization of energy, solve the problem of large fluctuations when wind energy is connected to the grid, and is an effective way to utilize industrial waste heat and absorb renewable energy electricity.

Claims

1. A thermal energy storage system integrating industrial waste heat, characterized in that: The thermal energy storage system includes an industrial waste heat utilization system, a high-temperature heat pump energy storage system and a high-temperature heat pump energy release system; wherein, The industrial waste heat utilization system comprises a high-temperature water tank (1), a low-temperature water tank (2), a first water pump (3) and a flue gas-water heat exchanger (19); wherein the low-temperature water in the low-temperature water tank (2) passes through the first water pump (3) and absorbs waste heat from industrial flue gas (22) in the flue gas-water heat exchanger (19), and after generating high-temperature water, enters the high-temperature water tank (1) for storage; The high-temperature heat pump energy storage system comprises a high-temperature water tank (1), a low-temperature water tank (2), a No. 2 water pump (4), a high-temperature molten salt storage tank (5), a low-temperature molten salt storage tank (6), a No. 1 molten salt pump (7), a working fluid-water heat exchanger (9), a No. 1 working fluid-working fluid heat exchanger (10), a heat pump charging compressor (11), a No. 1 working fluid-molten salt heat exchanger (12), a heat pump charging expander (13) and a wind power generator set (20); wherein the wind power generator set (20) inputs electric energy to drive the heat pump charging compressor (11) to work; the low-temperature and low-pressure working fluid absorbs heat in the working fluid-water heat exchanger (9) to generate a normal-temperature and low-pressure working fluid, and then enters the No. 1 working fluid-working fluid heat exchanger (10) to absorb heat; the medium-temperature and low-pressure working fluid at the outlet of the No. 1 working fluid-working fluid heat exchanger (10) passes through the heat pump charging compressor (11) and is heated to a temperature of 0.1°C. After the electric compressor (11), a high-temperature and high-pressure working fluid is generated, which then enters the No. 1 working fluid-molten salt heat exchanger (12) to release heat. The medium-temperature and high-pressure working fluid at the outlet of the No. 1 working fluid-molten salt heat exchanger (12) enters the No. 1 working fluid-working fluid heat exchanger (10) to release heat. The normal-temperature and high-pressure working fluid generated enters the heat pump charging expander (13) to perform work, and finally returns to the low-temperature and low-pressure working fluid to enter the working fluid-water heat exchanger (9), and repeats this process; at the same time, the high-temperature water in the high-temperature water tank (1) passes through the No. 2 water pump (4), releases heat in the working fluid-water heat exchanger (9), and then enters the low-temperature water tank (2) to form low-temperature water; the low-temperature molten salt in the low-temperature molten salt storage tank (6) passes through the No. 1 molten salt pump (7), absorbs heat in the No. 1 working fluid-molten salt heat exchanger (12), and then enters the high-temperature molten salt storage tank (5) to form high-temperature molten salt; The high-temperature heat pump energy release system comprises a high-temperature molten salt storage tank (5), a low-temperature molten salt storage tank (6), a No. 2 molten salt pump (8), a No. 2 working fluid-molten salt heat exchanger (14), a heat pump discharge expander (15), a No. 2 working fluid-working fluid heat exchanger (16), a working fluid-seawater heat exchanger (17), a heat pump discharge compressor (18) and a high-temperature heat pump generator (21); wherein the low-temperature and low-pressure working fluid generates a normal-temperature and high-pressure working fluid after passing through the heat pump discharge compressor (18), and then enters the No. 2 working fluid-working fluid heat exchanger (16) to absorb heat, and the medium-temperature and high-pressure working fluid at the outlet of the No. 2 working fluid-working fluid heat exchanger (16) enters the No. 2 working fluid-molten salt heat exchanger (14) to absorb heat to generate a high-temperature and high-pressure working fluid, and then enters the heat pump discharge compressor (18). The electric expander (15) performs work, driving the high-temperature heat pump generator (21) to generate electric energy, which is then output to the power grid. The medium-temperature low-pressure working fluid at the outlet of the heat pump discharge expander (15) enters the second working fluid-working fluid heat exchanger (16) to release heat and generate a normal-temperature low-pressure working fluid, and then enters the working fluid-seawater heat exchanger (17) to release heat, and finally returns to the low-temperature low-pressure working fluid to enter the heat pump discharge compressor (18), and repeats this process; wherein the high-temperature molten salt in the high-temperature molten salt storage tank (5) passes through the second molten salt pump (8), releases heat in the second working fluid-molten salt heat exchanger (14), and then enters the low-temperature molten salt storage tank (6) to form low-temperature molten salt; the low-temperature seawater (23) enters the working fluid-seawater heat exchanger (17) to absorb heat and evaporate to form water vapor.

2. A thermal energy storage system integrating industrial waste heat according to claim 1, characterized in that: Both the high-temperature water tank (1) and the low-temperature water tank (2) use normal pressure water as the heat storage medium, the pressure range is 0.6-0.9 MPa, the operating temperature range of the high-temperature water tank (1) is 130-150°C, and the operating temperature range of the low-temperature water tank (2) is 30-50°C; both the high-temperature molten salt storage tank (5) and the low-temperature molten salt storage tank (6) use ternary molten salt Hitec salt as the heat storage medium, the operating temperature range of the high-temperature molten salt storage tank (5) is 420-440°C, and the operating temperature range of the low-temperature molten salt storage tank (6) is 290-310°C.

3. The thermal energy storage system integrating industrial waste heat according to claim 1, characterized in that: The circulating working fluid used in the high-temperature heat pump energy storage system and the high-temperature heat pump energy release system is air, and the circulation form adopts the Brayton cycle. The maximum working temperature is 450°C and the minimum working temperature is 20°C.

4. The thermal energy storage system integrating industrial waste heat according to claim 1, characterized in that: The heat pump charging compressor (11) and the heat pump discharging compressor (18) are composed of at least four-stage compressors, using centrifugal compressors, and the inlet and outlet comprehensive pressure ratio reaches 6.9; the heat pump charging expander (13) and the heat pump discharging expander (15) are composed of at least three-stage expanders, using axial flow expanders, and the inlet and outlet comprehensive expansion ratio reaches 5.

8.

5. The thermal energy storage system integrating industrial waste heat according to claim 1, characterized in that: The working fluid-water heat exchanger (9), the first working fluid-working fluid heat exchanger (10), the second working fluid-working fluid heat exchanger (16), the first working fluid-molten salt heat exchanger (12), the second working fluid-molten salt heat exchanger (14) and the flue gas-water heat exchanger (19) all adopt shell and tube heat exchangers, and the working fluid-seawater heat exchanger (17) adopts a plate heat exchanger.

6. The thermal energy storage system integrating industrial waste heat according to claim 1, characterized in that: The high-temperature water tank (1) and the low-temperature water tank (2) are pressure water tanks, each including an inlet and an outlet; the high-temperature molten salt storage tank (5) and the low-temperature molten salt storage tank (6) include an inlet and an outlet.

7. The thermal energy storage system integrating industrial waste heat according to claim 1, characterized in that: The heat pump charging compressor (11) and the heat pump charging expander (13) are both coaxially connected to the wind power generator set (20); the heat pump discharging expander (15) and the heat pump discharging compressor (18) are both coaxially connected to the high-temperature heat pump generator (21).

8. The method for operating a thermal energy storage system integrating industrial waste heat according to any one of claims 1 to 7, characterized in that: 1) When the wind power generator set (20) is at a low point, the industrial waste heat utilization system starts to work, and the industrial flue gas (22) serves as a heat source for the high-temperature water tank (1). The industrial waste heat utilization system converts the heat energy in the industrial flue gas (22) into heat energy in the high-temperature water tank (1); specifically, the low-temperature water in the low-temperature water tank (2) passes through a first water pump (3) and absorbs the heat of the industrial flue gas in a flue gas-water heat exchanger (19), and is finally stored in the high-temperature water tank (1); 2) When the wind power generator set (20) is at its peak, the high-temperature heat pump energy storage system starts to work, and the electric energy output by the wind power generator set (20) is used as the input source of the heat pump charging compressor (11). The high-temperature heat pump energy storage system is used to convert the electric energy and the heat energy in the high-temperature water tank (1) into heat energy stored in the high-temperature molten salt storage tank (5); specifically, the working fluid absorbs the heat energy in the high-temperature water in the working fluid-water heat exchanger (9), then absorbs heat in the No. 1 working fluid-working fluid heat exchanger (10), enters the heat pump charging compressor (11) for pressurization, and then releases heat to the low-temperature molten salt in the No. 1 working fluid-molten salt heat exchanger (12), and finally stores the electric energy and the heat energy in the high-temperature water in the high-temperature molten salt storage tank (5); 3) When the power grid is at a peak of power consumption, the high-temperature heat pump energy release system starts to work, and the heat energy in the high-temperature molten salt storage tank (5) is used as the heat source of the working fluid. The high-temperature heat pump energy release system is used to convert the heat energy in the high-temperature molten salt storage tank (5) into electrical energy and heat energy in seawater. Specifically, the working fluid is pressurized in the heat pump discharge compressor (18) and enters the second working fluid-working fluid heat exchanger (16) to absorb heat, then enters the second working fluid-molten salt heat exchanger (14) to absorb the heat energy of the high-temperature molten salt, then enters the heat pump discharge expander (15) to perform work, and is converted into electrical energy in the high-temperature heat pump generator (21) and output to the power grid. The seawater absorbs heat and evaporates in the working fluid-seawater heat exchanger (17), and finally the heat energy in the high-temperature molten salt is converted into electrical energy and heat energy in the seawater.

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