Thermoelectric decoupling system based on ultrahigh-temperature heat pump and fused salt energy storage and control method

Abstract

The invention provides a thermoelectric decoupling system based on an ultrahigh-temperature heat pump and fused salt energy storage and a control method, and belongs to the technical field of energy storage and heat supply. The system comprises an ultrahigh-temperature heat pump circulating unit connected with a circulating cooling water outlet of a condenser and used for heating gas by using heat in circulating cooling water to form overheated gas; the fused salt energy storage heat exchange unit is connected with the ultra-high-temperature heat pump circulation unit and is used for heating the low-temperature fused salt by using the overheated gas to form high-temperature fused salt and storing the high-temperature fused salt; the steam power generation unit is connected with the fused salt energy storage and heat exchange unit, and is used for heating the supplied water by using high-temperature fused salt to generate steam and generating power by using the steam; and the heating unit is connected with the fused salt energy storage heat exchange unit, and is used for heating the heating circulating water by using the low-temperature fused salt and conveying the heating circulating water to a heat user. The system is simple in structure, low in operation cost and high in safety, and the influence on the generator set during large-amplitude variable load operation and ultralow load operation can be reduced while normal heating is guaranteed.

Description

Technical Field

[0001] The present invention relates to the field of energy storage heating technology, and specifically to a thermoelectric decoupling system based on an ultra-high temperature heat pump and molten salt energy storage, a control method for a thermoelectric decoupling system based on an ultra-high temperature heat pump and molten salt energy storage, an electronic device and a readable storage medium. Background Art

[0002] At present, there are two main types of flexibility transformation of thermal power units. One is internal transformation of the unit, such as turbine flow modification, low-load stable combustion of boilers, etc., to enhance the peak-shaving capacity of the unit, shorten the start-up and shutdown time of the unit, and coordinate low-load control; the other is external transformation of the unit, such as thermal-electric decoupling, adding power storage or heat storage devices. Among them, the heat storage technologies applicable to thermal-electric decoupling mainly include molten salt heat storage and solid heat storage.

[0003] The main principle of molten salt energy storage technology is to use the advantages of thermal stability, high specific heat capacity, good chemical stability, and low saturated vapor pressure of molten salt and other media to store heat. This heat can generate high-parameter steam and reuse it for power generation or heating. The high-temperature media in large thermal power units include flue gas, high-pressure main steam, and high-temperature reheat steam, which can all be exchanged and stored with molten salt through heat exchangers. At present, in order to improve the system conversion efficiency of large thermal power units, most power plants choose to extract boiler main steam, boiler high-temperature reheat steam, and turbine interstage reheat steam for heat storage, so as to achieve flexible peak regulation of thermal power units. Some power plants use high-temperature flue gas from boilers to heat molten salt for heat storage, so as to achieve flexible peak regulation of thermal power units.

[0004] The current molten salt heat storage technology is limited by the problem of boiler reheater overheating. It can only store heat when the thermal power unit is operating normally, but cannot store heat under deep peak-shaving and low-load conditions, and the peak-shaving capacity is limited. When the high-pressure main steam is exchanged with molten salt for heat storage, it is limited by the safety of the boiler reheater and can only extract a small amount of steam for energy storage, which cannot meet the requirements of deep peak-shaving. Because the saturation temperature corresponding to the steam pressure is lower than the risk temperature of molten salt solidification, only part of the sensible heat can be exchanged with molten salt for heat storage, which cannot meet the requirements of deep peak-shaving. Some units adopt the highest temperature grade of flue gas, and the flue gas temperature at the furnace outlet is still as high as 700-800℃ at low load. However, when a large amount of flue gas at the furnace outlet is extracted for heat storage, it will cause an imbalance in the heating ratio of the tail flue heat exchanger, resulting in substandard steam parameters. Summary of the invention

[0005] The purpose of the embodiments of the present invention is to provide a thermoelectric decoupling system and method based on an ultra-high temperature heat pump and molten salt energy storage, so as to solve the above-mentioned problem that the current molten salt heat storage technology is limited by the overtemperature problem of the boiler reheater, can only store heat when the thermal power unit is operating normally, and cannot store heat under deep peak-shaving and low-load conditions. The peak-shaving capacity is limited, the operating safety is low, and the heating ratio of the tail flue heat exchanger is unbalanced, resulting in the problem that the steam parameters do not meet the standards.

[0006] In order to achieve the above objectives, in a first aspect, an embodiment of the present invention provides a thermoelectric decoupling system based on an ultra-high temperature heat pump and molten salt energy storage, the system comprising: The ultra-high temperature heat pump circulation unit is connected to the condenser circulating cooling water pipe and is used to heat the gas using the heat in the circulating cooling water to form superheated gas; The molten salt energy storage heat exchange unit is connected to the ultra-high temperature heat pump circulation unit and is used to heat the low-temperature molten salt with superheated gas to form high-temperature molten salt and store the high-temperature molten salt; A steam power generation unit, connected to the molten salt energy storage and heat exchange unit, for heating feed water with high-temperature molten salt to generate steam and generate electricity using the steam; The heating unit is connected to the molten salt energy storage and heat exchange unit, and is used to heat the heating circulating water using the low-temperature molten salt, and transport the heating circulating water to the heat users.

[0007] Optionally, the ultra-high temperature heat pump circulation unit includes: An air turbine group, a first air heater, a regenerator, an air compressor and a second air heater are sequentially connected along the gas flow direction; The heat mass inlet and medium outlet of the first air heater are connected to the condenser circulating cooling water pipe; The gas outlet of the second air heater is connected to the gas inlet of the regenerator, and the gas outlet of the regenerator is connected to the gas inlet of the air turbine group; A first valve is provided between the heat medium inlet of the first air heater and the condenser circulating cooling water pipe.

[0008] Optionally, the ultra-high temperature heat pump circulation unit further includes: An electric motor, used to drive the air turbine group and the air compressor; A gas storage tank, wherein the gas outlet of the gas storage tank is connected to the gas inlet of the air turbine group.

[0009] Optionally, the molten salt energy storage and heat exchange unit includes: A low-temperature molten salt tank, used for storing low-temperature molten salt, wherein the molten salt outlet of the low-temperature molten salt tank is connected to the medium inlet of the second air heater, and the molten salt inlet of the low-temperature molten salt tank is connected to the molten salt outlet of the steam power generation unit, and the second air heater is used for heating the low-temperature molten salt into high-temperature molten salt by using superheated gas; A high-temperature molten salt tank, used for storing high-temperature molten salt, wherein a molten salt inlet of the high-temperature molten salt tank is connected to a medium outlet of the second air heater, and a molten salt outlet of the high-temperature molten salt tank is connected to a molten salt inlet of the steam power generation unit; A second valve is provided between the molten salt outlet of the low-temperature molten salt tank and the molten salt inlet of the second air heater, and a third valve is provided between the molten salt outlet of the high-temperature molten salt tank and the molten salt inlet of the steam power generation unit.

[0010] Optionally, the molten salt energy storage and heat exchange unit further includes: A low-temperature molten salt pump is arranged at the molten salt outlet of the low-temperature molten salt tank; A high-temperature molten salt pump is arranged at the molten salt outlet end of the high-temperature molten salt tank.

[0011] Optionally, the steam power generation unit comprises: A superheater, a saturator and a preheater are sequentially arranged along the molten salt flow direction, the molten salt inlet of the superheater is connected to the molten salt outlet of the high-temperature molten salt tank, and the molten salt outlet of the preheater is connected to the molten salt inlet of the low-temperature molten salt tank; The gas outlet of the superheater is connected to the steam turbine, and the liquid inlet of the preheater is connected to the feed water pipe.

[0012] Optionally, the heating unit comprises: A molten salt energy storage heat exchange tank, a medium heat exchanger, a buffer tank and a circulation pump are sequentially connected along the medium flow direction; The molten salt inlet of the molten salt energy storage heat exchange tank is connected to the molten salt outlet of the low-temperature molten salt tank, the molten salt outlet of the molten salt energy storage heat exchange tank is connected to the molten salt inlet of the low-temperature molten salt tank, a fourth valve is provided between the molten salt inlet of the molten salt energy storage heat exchange tank and the molten salt outlet of the low-temperature molten salt tank, a fifth valve is provided between the medium outlet of the molten salt energy storage heat exchange tank and the medium inlet of the medium heat exchanger, and a sixth valve is provided between the medium outlet of the circulating pump and the medium inlet of the molten salt energy storage heat exchange tank; The heating circulating water outlet and the heating circulating water inlet of the medium heat exchanger are connected to the heat user; The medium outlet of the circulation pump is also connected to the medium inlet of the medium heat exchanger, and a seventh valve is arranged between the medium outlet of the circulation pump and the medium inlet of the medium heat exchanger.

[0013] In a second aspect, an embodiment of the present invention provides a control method for a thermoelectric decoupling system based on an ultra-high temperature heat pump and molten salt energy storage, which is applied to the above-mentioned thermoelectric decoupling system based on an ultra-high temperature heat pump and molten salt energy storage, and the method includes: Make sure the system is in non-heating energy storage condition: The first valve and the second valve are turned on, the fourth to seventh valves are closed, and the low-temperature molten salt is heated to high-temperature molten salt by the second air heater; Make sure the system is in non-heating and power generation mode: The first valve, the second valve and the third valve are turned on, and the fourth to seventh valves are closed, and the feed water is heated by high-temperature molten salt to form steam for power generation; Make sure the system is in molten salt heating condition: The fourth valve, the fifth valve and the sixth valve are turned on, and the seventh valve is closed, and the medium is heated by the low-temperature molten salt, and the heated medium is used to heat the return water of the heating circulation water; Make sure the system is in heating and energy storage mode: The seventh valve is turned on, the fourth to sixth valves are closed, and the medium is heated by the return water of the heating circulation water.

[0014] In a third aspect, an embodiment of the present invention provides an electronic device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the above-mentioned control method of the thermoelectric decoupling system based on ultra-high temperature heat pump and molten salt energy storage when executing the computer program.

[0015] In a fourth aspect, an embodiment of the present invention provides a readable storage medium having instructions stored thereon, the instructions being used to enable a machine to execute the above-mentioned control method for a thermoelectric decoupling system based on an ultra-high temperature heat pump and molten salt energy storage.

[0016] This technical solution has a simple structure, low operating cost and high operating safety. While ensuring normal heating, it can reduce the impact on the generator set during large-scale load variation and ultra-low load operation, ensuring that the unit can achieve normal deep peak regulation.

[0017] Other features and advantages of the embodiments of the present invention will be described in detail in the subsequent detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The accompanying drawings are used to provide a further understanding of the embodiments of the present invention and constitute a part of the specification. Together with the following specific implementations, they are used to explain the embodiments of the present invention, but do not constitute a limitation on the embodiments of the present invention. In the accompanying drawings: Figure 1 It is a schematic diagram of the overall structure of the thermoelectric decoupling system based on ultra-high temperature heat pump and molten salt energy storage provided by the present invention; Figure 2 It is a specific structural schematic diagram of the thermoelectric decoupling system based on ultra-high temperature heat pump and molten salt energy storage provided by the present invention; Figure 3 It is a flow chart of a control method of a thermoelectric decoupling system based on an ultra-high temperature heat pump and molten salt energy storage under the first working condition provided by the present invention; Figure 4 It is a flow chart of a control method of a thermoelectric decoupling system based on an ultra-high temperature heat pump and molten salt energy storage under the second working condition provided by the present invention; Figure 5 It is a flow chart of a control method of a thermoelectric decoupling system based on an ultra-high temperature heat pump and molten salt energy storage under a third working condition provided by the present invention; Figure 6 It is a flow chart of a control method for a thermoelectric decoupling system based on an ultra-high temperature heat pump and molten salt energy storage under the fourth working condition provided by the present invention.

[0019] Description of Reference Numerals 1-Ultra-high temperature heat pump circulation unit; 2-Condenser circulation cooling water pipe; 3-Molten salt energy storage heat exchange unit; 4-steam power generation unit; 5-heating unit; 6-heat user; 7- water supply pipe; 11- air turbine group; 12- first air heater; 13-regenerator; 14-air compressor; 15-second air heater; 16-first valve; 17-electric motor; 18-gas storage tank; 31- low temperature molten salt tank; 32- high temperature molten salt tank; 33- second valve; 34-the third valve; 35-low-temperature molten salt pump; 36-high-temperature molten salt pump; 41-superheater; 42-saturator; 43-preheater; 44-steam turbine; 51-molten salt energy storage heat exchange tank; 52-medium heat exchanger; 53-buffer tank; 54-circulation pump; 55-fourth valve; 56-fifth valve; 57-sixth valve; 58-seventh valve. DETAILED DESCRIPTION

[0020] The specific implementation of the embodiment of the present invention is described in detail below in conjunction with the accompanying drawings. It should be understood that the specific implementation described here is only used to illustrate and explain the embodiment of the present invention, and is not used to limit the embodiment of the present invention.

[0021] In the embodiments of the present invention, unless otherwise specified, directional words such as "up, down, left, right" generally refer to the directions or positional relationships shown in the accompanying drawings, or the directions or positional relationships in which the inventive product is usually placed when in use.

[0022] The terms “first”, “second”, “third”, etc. are only used for distinguishing descriptions and should not be understood as indicating or implying relative importance.

[0023] The terms "parallel", "vertical", etc. do not mean that the components must be absolutely parallel or vertical, but can be slightly tilted. For example, "parallel" only means that its direction is more parallel than "vertical", and does not mean that the structure must be completely parallel, but can be slightly tilted.

[0024] The terms "horizontal", "vertical", "overhanging" and the like do not mean that the components are required to be absolutely horizontal, vertical or overhanging, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0025] In addition, the terms "roughly" and "basically" are intended to explain that the relevant content does not require absolute precision, but can have certain deviations. For example, "roughly equal" does not only mean absolute equality. Since it is difficult to achieve absolute "equality" in actual production and operation, there are generally certain deviations. Therefore, in addition to absolute equality, "roughly equal" also includes the above-mentioned situation with certain deviations. Taking this as an example, in other cases, unless otherwise specified, the terms "roughly" and "basically" have similar meanings to the above.

[0026] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0027] Figure 1 It is a schematic diagram of the overall structure of the thermoelectric decoupling system based on ultra-high temperature heat pump and molten salt energy storage provided by the present invention; Figure 2 It is a specific structural schematic diagram of the thermoelectric decoupling system based on ultra-high temperature heat pump and molten salt energy storage provided by the present invention; Figure 3 It is a flow chart of a control method of a thermoelectric decoupling system based on an ultra-high temperature heat pump and molten salt energy storage under the first working condition provided by the present invention; Figure 4 It is a flow chart of a control method of a thermoelectric decoupling system based on an ultra-high temperature heat pump and molten salt energy storage under the second working condition provided by the present invention; Figure 5 It is a flow chart of a control method of a thermoelectric decoupling system based on an ultra-high temperature heat pump and molten salt energy storage under a third working condition provided by the present invention; Figure 6 It is a flow chart of a control method for a thermoelectric decoupling system based on an ultra-high temperature heat pump and molten salt energy storage under the fourth working condition provided by the present invention.

[0028] like Figure 1 As shown, this embodiment provides a thermoelectric decoupling system based on an ultra-high temperature heat pump and molten salt energy storage, the system comprising: The ultra-high temperature heat pump circulation unit 1 is connected to the condenser circulating cooling water pipe 2 and is used to heat the gas using the heat in the circulating cooling water to form superheated gas; The molten salt energy storage heat exchange unit 3 is connected to the ultra-high temperature heat pump circulation unit 1 and is used to heat the low-temperature molten salt with superheated gas to form high-temperature molten salt and store the high-temperature molten salt; A steam power generation unit 4 is connected to the molten salt energy storage and heat exchange unit 3 and is used to use high-temperature molten salt to heat feed water to generate steam and use the steam to generate electricity; The heating unit 5 is connected to the molten salt energy storage and heat exchange unit 3 and is used to heat heating circulating water using low-temperature molten salt and transport the heating circulating water to the heat user 6 .

[0029] Specifically, in this embodiment, the condenser circulating cooling water is used as the heat source of the ultra-high temperature heat pump circulation unit 1, so that the ultra-high temperature heat pump circulation unit 1 consumes less high-level energy of the thermal power generating set, and the heat supplied is the sum of the consumed high-level energy and the absorbed low-level heat, thereby making full use of low-grade waste heat energy to reduce coal consumption.

[0030] Furthermore, the ultra-high temperature heat pump circulation unit 1 comprises: An air turbine group 11, a first air heater 12, a regenerator 13, an air compressor 14 and a second air heater 15 are sequentially connected along the gas flow direction; The heat mass inlet and medium outlet of the first air heater 12 are connected to the condenser circulating cooling water pipe 2; The gas outlet of the second air heater 15 is connected to the gas inlet of the regenerator 13, and the gas outlet of the regenerator 13 is connected to the gas inlet of the air turbine group 11; A first valve 16 is provided between the heat medium inlet of the first air heater 12 and the condenser circulating cooling water pipe 2 .

[0031] Specifically, in this embodiment, the air compressor 14 is the main energy-consuming equipment that affects the energy efficiency of the ultra-high temperature heat pump circulation unit 1. Therefore, the main way to improve the energy efficiency of the ultra-high temperature heat pump in this solution is to reduce the energy consumption of the air compressor.

[0032] Furthermore, the ultra-high temperature heat pump circulation unit 1 further comprises: An electric motor 17, used for driving the air turbine group 11 and the air compressor 14; A gas storage tank 18 , a gas outlet of the gas storage tank 18 is connected to a gas inlet of the air turbine group 11 .

[0033] Specifically, in this embodiment, the motor 17 is driven by the electric energy generated by the thermal power generating set. When the thermal power generating set enters deep peak regulation, the excess electric energy generated by the thermal power generating set is supplied to the motor 17. The motor drives the air turbine group 11 to work, thereby transporting the gas to the first air heater 12 for heat exchange.

[0034] The gas inlet of the gas storage tank 18 is connected to the gas outlet of the compressor through a pipeline. The compressor is driven by the electric energy generated by the thermal power generating set. The gas storage tank 18 can store gas with a certain pressure. Similarly, when the thermal power generating set enters deep peak regulation, the excess electric energy generated by the thermal power generating set is supplied to the compressor to compress the gas, and the compressed gas is sent to the gas storage tank 18 for storage. When the thermal power generating set has not entered deep peak regulation (the power generation is less than or equal to the power required by the power grid), the electric energy generated by the thermal power generating set cannot be supplied to the motor 17. Therefore, the compressed gas is supplied to the first air heater 12 by the gas storage tank 18.

[0035] Furthermore, the molten salt energy storage and heat exchange unit 3 comprises: A low-temperature molten salt tank 31 is used to store low-temperature molten salt, the molten salt outlet of the low-temperature molten salt tank 31 is connected to the medium inlet of the second air heater 15, the molten salt inlet of the low-temperature molten salt tank 31 is connected to the molten salt outlet of the steam power generation unit 4, and the second air heater 15 is used to heat the low-temperature molten salt into high-temperature molten salt by using superheated gas; A high-temperature molten salt tank 32 is used to store high-temperature molten salt, wherein the molten salt inlet of the high-temperature molten salt tank 32 is connected to the medium outlet of the second air heater 15, and the molten salt outlet of the high-temperature molten salt tank 32 is connected to the molten salt inlet of the steam power generation unit 4; A second valve 33 is provided between the molten salt outlet of the low-temperature molten salt tank 31 and the molten salt inlet of the second air heater 15 , and a third valve 34 is provided between the molten salt outlet of the high-temperature molten salt tank 32 and the molten salt inlet of the steam power generation unit 4 .

[0036] In another embodiment, the molten salt inlet of the steam power generation unit 4 is connected to the molten salt outlet of the second air heater 15 through a pipeline, so that the high-temperature molten salt formed by heating by the second air heater 15 is directly transported to the steam power generation unit 4 for utilization without being stored in the high-temperature molten salt tank 32, thereby improving energy utilization efficiency.

[0037] Furthermore, the molten salt energy storage and heat exchange unit 3 also includes: A low-temperature molten salt pump 35 is provided at the molten salt outlet of the low-temperature molten salt tank 31; The high-temperature molten salt pump 36 is arranged at the molten salt outlet end of the high-temperature molten salt tank 32 .

[0038] Specifically, in this embodiment, the low-temperature molten salt pump 35 and the high-temperature molten salt pump 36 are provided to promote the normal flow of the molten salt, thereby ensuring the heat exchange effect.

[0039] Furthermore, the steam power generation unit 4 comprises: A superheater 41, a saturator 42 and a preheater 43 are sequentially arranged along the molten salt flow direction, wherein the molten salt inlet of the superheater 41 is connected to the molten salt outlet of the high-temperature molten salt tank 32, and the molten salt outlet of the preheater 43 is connected to the molten salt inlet of the low-temperature molten salt tank 31; The gas outlet of the superheater 41 is connected to the steam turbine 44 , and the liquid inlet of the preheater 43 is connected to the feed water pipe 7 .

[0040] Specifically, in this embodiment, along the flow direction of the molten salt, the superheater 41, the saturator 42 and the preheater 43 are connected in sequence. Similarly, along the flow direction of the power generation medium (steam), the preheater 43, the saturator 42 and the superheater 41 are connected in sequence. In one embodiment, in addition to the feed water, steam can also be used to replace the feed water to inject into the liquid inlet of the preheater 43, thereby improving the power generation efficiency.

[0041] Furthermore, the heating unit 5 comprises: A molten salt energy storage heat exchange tank 51, a medium heat exchanger 52, a buffer tank 53 and a circulation pump 54 are sequentially connected along the medium flow direction; The molten salt inlet of the molten salt energy storage heat exchange tank 51 is connected to the molten salt outlet of the low-temperature molten salt tank 31, and the molten salt outlet of the molten salt energy storage heat exchange tank 51 is connected to the molten salt inlet of the low-temperature molten salt tank 31. A fourth valve 55 is provided between the molten salt inlet of the molten salt energy storage heat exchange tank 51 and the molten salt outlet of the low-temperature molten salt tank 31, a fifth valve 56 is provided between the medium outlet of the molten salt energy storage heat exchange tank 51 and the medium inlet of the medium heat exchanger 52, and a sixth valve 57 is provided between the medium outlet of the circulating pump 54 and the medium inlet of the molten salt energy storage heat exchange tank 51; The heating circulating water outlet and the heating circulating water inlet of the medium heat exchanger 52 are connected to the heat user 6; The medium outlet of the circulation pump 54 is also connected to the medium inlet of the medium heat exchanger 52 , and a seventh valve 58 is provided between the medium outlet of the circulation pump 54 and the medium inlet of the medium heat exchanger 52 .

[0042] Specifically, in this embodiment, the heating unit 5 is provided with two circulation paths. First, the medium can be heated by using the low-level heat contained in the low-temperature molten salt through the molten salt energy storage heat exchange tank 51, and the heating circulating water can be heated through the medium heat exchanger 52; and when the heating circulating water itself has a high heat, the medium stored in the buffer tank 53 is heated, thereby reducing the energy consumption of the subsequent heating medium. By adopting different medium flow modes in different situations, the utilization rate of energy can be improved.

[0043] In this solution, the first valve 16, the second valve 33, the third valve 34, the fourth valve 55, the fifth valve 56, the sixth valve 57 and the seventh valve 58 are all electrically controlled valves, thereby realizing automatic control.

[0044] This technical solution takes into account the high temperature properties of electricity-to-heat, the maturity of the variable operating condition design of the compressor equipment, and the reliability of operation. The whole set of equipment can extract low-quality heat energy by consuming part of the electricity to generate high-quality heat energy. The supporting molten salt storage and heat exchange unit mainly draws on the design of the existing solar thermal power station energy storage system and heat exchange system, and is mainly used for the storage and consumption of heat generated by ultra-high temperature heat pumps. The molten salt energy storage flexibility transformation and heating transformation of the thermal power unit are designed, constructed, and put into use at the same time, providing new ideas and new technologies for the "three-in-one" of coal-fired power units with a capacity of 300MW and below. At the same time, the molten salt energy storage thermoelectric coupling technology is adopted. Under the premise of ensuring the stability of the heat source parameters during the heating period, the unit load can be flexibly adjusted according to the grid instructions. The construction of this solution occupies a small area, the operation system of the thermal power unit is changed less, the impact on the operating conditions is minimal, the investment cost is low, and the system is simple and easy to maintain and repair in the later stage.

[0045] The embodiment of the present invention further provides a control method for a thermoelectric decoupling system based on an ultra-high temperature heat pump and molten salt energy storage, which is applied to the above-mentioned thermoelectric decoupling system based on an ultra-high temperature heat pump and molten salt energy storage, and the method comprises: like Figure 3 As shown, it is determined that the system is in non-heating energy storage condition: The first valve and the second valve are turned on, the fourth to seventh valves are closed, and the low-temperature molten salt is heated to high-temperature molten salt by the second air heater; Specifically, in this embodiment, after the first valve is turned on, the condenser circulating cooling water is used as a heat source, and the air turbine group is started, which can increase the air flow rate entering the inlet of the first air heater, help to strengthen the convective heat exchange of the first air heater, and improve the heat exchange effect. The gas entering the air compressor is turned into superheated steam through the regenerator, which reduces harmful steam heat, vaporizes the droplets entrained in the return air, and prevents liquid hammer from occurring in the air compressor. The second valve closes the fourth to seventh valves, and starts the low-temperature molten salt pump, so that the low-temperature molten salt is heated by the second air heater to form high-temperature molten salt, and the heat is stored in the high-temperature molten salt tank.

[0046] like Figure 4 As shown, it is determined that the system is in non-heating power generation condition: The first valve, the second valve and the third valve are turned on, and the fourth to seventh valves are closed, and the feed water is heated by high-temperature molten salt to form steam for power generation; Specifically, in this embodiment, during the high load period of the unit, the third valve is opened, and the high temperature molten salt pump is started to pump the high temperature molten salt into the steam power generation unit, perform heat exchange with water / steam, generate superheated steam, and enter the steam turbine to generate power. After heat exchange in the steam power generation unit, the temperature of the molten salt is reduced and returned to the low temperature molten salt tank.

[0047] In another embodiment, the molten salt inlet of the steam power generation unit is connected to the molten salt outlet of the second air heater through a pipeline, so that the high-temperature molten salt formed by heating by the second air heater is directly transported to the steam power generation unit without passing through the high-temperature molten salt tank.

[0048] like Figure 5 As shown, it is determined that the system is in the molten salt heating condition: The fourth valve, the fifth valve and the sixth valve are turned on, and the seventh valve is closed, and the medium is heated by the low-temperature molten salt, and the heated medium is used to heat the return water of the heating circulation water; Specifically, in this embodiment, during the heating period using molten salt energy storage: the fourth valve, the fifth valve and the sixth valve are turned on, the seventh valve is closed, and the circulation pump is started, the residual heat in the low-temperature molten salt tank is used to heat and store the molten salt in the molten salt energy storage heat exchange tank, and the molten salt after the molten salt energy storage heat exchange tank releases heat returns to the low-temperature molten salt tank, and the normal temperature water in the buffer tank flows through the circulation pump, the molten salt energy storage heat exchange tank, and the heat exchanger in turn before flowing back to the buffer tank. The molten salt energy storage heat exchange tank is used to realize the primary heat exchange between molten salt and water, and the heat exchanger is used to realize the secondary heat exchange between circulating water and heating return water, and heat is supplied to heat users through the heating circulation pump.

[0049] like Figure 6 As shown, it is determined that the system is in the heating energy storage condition: The seventh valve is turned on, the fourth to sixth valves are closed, and the medium is heated by the return water of the heating circulation water.

[0050] Specifically, in this embodiment, when entering the heating energy storage condition: the seventh valve is turned on, and the heating circulation pump is started, hot water is introduced into the buffer tank or the water in the buffer tank is heated, and the hot water in the buffer tank flows through the circulation pump and the heat exchanger in sequence and then flows back into the buffer tank. The heat exchanger is used to realize heat exchange between the hot water in the buffer tank and the heating return water, and the heating return water is used to heat the hot water in the buffer tank.

[0051] An embodiment of the present invention also provides an electronic device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the above-mentioned control method of the thermoelectric decoupling system based on ultra-high temperature heat pump and molten salt energy storage when executing the computer program.

[0052] An embodiment of the present invention further provides a readable storage medium having instructions stored thereon, the instructions being used to enable a machine to execute the above-mentioned control method for the thermoelectric decoupling system based on an ultra-high temperature heat pump and molten salt energy storage.

[0053] The optional implementation modes of the embodiments of the present invention are described in detail above in conjunction with the accompanying drawings. However, the embodiments of the present invention are not limited to the specific details in the above implementation modes. Within the technical concept of the embodiments of the present invention, various simple modifications can be made to the technical scheme of the embodiments of the present invention, and these simple modifications all belong to the protection scope of the embodiments of the present invention.

[0054] Those skilled in the art can understand that all or part of the steps in the above-mentioned embodiment method can be completed by instructing the relevant hardware through a program, and the program is stored in a storage medium, including several instructions for making a single-chip microcomputer, a chip or a processor (processor) perform all or part of the steps of the method described in each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk and other media that can store program codes.

[0055] The optional embodiments of the present invention are described in detail above in conjunction with the accompanying drawings. However, the embodiments of the present invention are not limited to the specific details in the above embodiments. Within the technical concept of the embodiments of the present invention, the technical scheme of the embodiments of the present invention can be subjected to a variety of simple modifications, and these simple modifications all belong to the protection scope of the embodiments of the present invention. It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner when there is no contradiction. In order to avoid unnecessary repetition, the embodiments of the present invention will not further describe various possible combinations. In addition, various implementation modes of the embodiments of the present invention may be arbitrarily combined, and as long as they do not violate the concept of the embodiments of the present invention, they should also be regarded as the contents disclosed by the embodiments of the present invention.

Claims

1. A thermoelectric decoupling system based on ultra-high temperature heat pump and molten salt energy storage, characterized in that: The system comprises: The ultra-high temperature heat pump circulation unit (1) is connected to the condenser circulating cooling water pipe (2) and is used to utilize the heat in the circulating cooling water to heat the gas to form superheated gas; A molten salt energy storage heat exchange unit (3) is connected to the ultra-high temperature heat pump circulation unit (1) and is used to heat low-temperature molten salt using superheated gas to form high-temperature molten salt and store the high-temperature molten salt; A steam power generation unit (4) connected to the molten salt energy storage and heat exchange unit (3) and used to use high-temperature molten salt to heat feed water to generate steam and use the steam to generate electricity; The heating unit (5) is connected to the molten salt energy storage and heat exchange unit (3) and is used to heat heating circulating water using low-temperature molten salt and transport the heating circulating water to a heat user (6).

2. The thermoelectric decoupling system based on ultra-high temperature heat pump and molten salt energy storage according to claim 1 is characterized in that: The ultra-high temperature heat pump circulation unit (1) comprises: An air turbine group (11), a first air heater (12), a regenerator (13), an air compressor (14), and a second air heater (15) connected in sequence along a gas flow direction; The heat mass inlet and the medium outlet of the first air heater (12) are connected to the condenser circulating cooling water pipe (2); The gas outlet of the second air heater (15) is connected to the gas inlet of the regenerator (13), and the gas outlet of the regenerator (13) is connected to the gas inlet of the air turbine group (11); A first valve (16) is provided between the heat medium inlet of the first air heater (12) and the condenser circulating cooling water pipe (2).

3. The thermoelectric decoupling system based on ultra-high temperature heat pump and molten salt energy storage according to claim 2 is characterized in that: The ultra-high temperature heat pump circulation unit (1) further comprises: An electric motor (17) for driving the air turbine assembly (11) and the air compressor (14); A gas storage tank (18), wherein the gas outlet of the gas storage tank (18) is connected to the gas inlet of the air turbine group (11).

4. The thermoelectric decoupling system based on ultra-high temperature heat pump and molten salt energy storage according to claim 2 is characterized in that: The molten salt energy storage and heat exchange unit (3) comprises: A low-temperature molten salt tank (31) is used to store low-temperature molten salt, the molten salt outlet of the low-temperature molten salt tank (31) is connected to the medium inlet of the second air heater (15), the molten salt inlet of the low-temperature molten salt tank (31) is connected to the molten salt outlet of the steam power generation unit (4), and the second air heater (15) is used to heat the low-temperature molten salt into high-temperature molten salt using superheated gas; A high-temperature molten salt tank (32) for storing high-temperature molten salt, wherein a molten salt inlet of the high-temperature molten salt tank (32) is connected to a medium outlet of the second air heater (15), and a molten salt outlet of the high-temperature molten salt tank (32) is connected to a molten salt inlet of the steam power generation unit (4); A second valve (33) is provided between the molten salt outlet of the low-temperature molten salt tank (31) and the molten salt inlet of the second air heater (15), and a third valve (34) is provided between the molten salt outlet of the high-temperature molten salt tank (32) and the molten salt inlet of the steam power generation unit (4).

5. The thermoelectric decoupling system based on ultra-high temperature heat pump and molten salt energy storage according to claim 4 is characterized in that: The molten salt energy storage and heat exchange unit (3) further comprises: A low-temperature molten salt pump (35), arranged at a molten salt outlet end of the low-temperature molten salt tank (31); A high-temperature molten salt pump (36) is arranged at the molten salt outlet end of the high-temperature molten salt tank (32).

6. The thermoelectric decoupling system based on ultra-high temperature heat pump and molten salt energy storage according to claim 4 is characterized in that: The steam power generation unit (4) comprises: A superheater (41), a saturator (42), and a preheater (43) are sequentially arranged along the molten salt flow direction, wherein the molten salt inlet of the superheater (41) is connected to the molten salt outlet of the high-temperature molten salt tank (32), and the molten salt outlet of the preheater (43) is connected to the molten salt inlet of the low-temperature molten salt tank (31); The gas outlet of the superheater (41) is connected to the steam turbine (44), and the liquid inlet of the preheater (43) is connected to the feed water pipe (7).

7. The thermoelectric decoupling system based on ultra-high temperature heat pump and molten salt energy storage according to claim 4 is characterized in that: The heating unit (5) comprises: A molten salt energy storage heat exchange tank (51), a medium heat exchanger (52), a buffer tank (53), and a circulation pump (54) connected in sequence along a medium flow direction; The molten salt inlet of the molten salt energy storage heat exchange tank (51) is connected to the molten salt outlet of the low-temperature molten salt tank (31); the molten salt outlet of the molten salt energy storage heat exchange tank (51) is connected to the molten salt inlet of the low-temperature molten salt tank (31); a fourth valve (55) is provided between the molten salt inlet of the molten salt energy storage heat exchange tank (51) and the molten salt outlet of the low-temperature molten salt tank (31); a fifth valve (56) is provided between the medium outlet of the molten salt energy storage heat exchange tank (51) and the medium inlet of the medium heat exchanger (52); and a sixth valve (57) is provided between the medium outlet of the circulating pump (54) and the medium inlet of the molten salt energy storage heat exchange tank (51); The heating circulating water outlet and the heating circulating water inlet of the medium heat exchanger (52) are connected to the heat user (6); The medium outlet of the circulation pump (54) is also connected to the medium inlet of the medium heat exchanger (52), and a seventh valve (58) is provided between the medium outlet of the circulation pump (54) and the medium inlet of the medium heat exchanger (52).

8. A control method for a thermoelectric decoupling system based on an ultra-high temperature heat pump and molten salt energy storage, applied to the thermoelectric decoupling system based on an ultra-high temperature heat pump and molten salt energy storage according to any one of claims 1 to 7, characterized in that: The method comprises: Make sure the system is in non-heating energy storage condition: The first valve and the second valve are turned on, the fourth to seventh valves are closed, and the low-temperature molten salt is heated to high-temperature molten salt by the second air heater; Make sure the system is in non-heating and power generation mode: The first valve, the second valve and the third valve are turned on, and the fourth to seventh valves are closed, and the feed water is heated by high-temperature molten salt to form steam for power generation; Make sure the system is in molten salt heating condition: The fourth valve, the fifth valve and the sixth valve are turned on, and the seventh valve is closed, and the medium is heated by the low-temperature molten salt, and the heated medium is used to heat the return water of the heating circulation water; Make sure the system is in heating and energy storage mode: The seventh valve is turned on, the fourth to sixth valves are closed, and the medium is heated by the return water of the heating circulation water.

9. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, the control method of the thermoelectric decoupling system based on the ultra-high temperature heat pump and molten salt energy storage according to claim 8 is implemented.

10. A readable storage medium having instructions stored thereon, the instructions being used to enable a machine to execute the control method of a thermoelectric decoupling system based on an ultra-high temperature heat pump and molten salt energy storage as described in claim 8.

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