Cross-seasonal water body heat storage and supply system and method based on photovoltaic direct drive

Abstract

The invention discloses a cross-seasonal water body heat storage and supply system and method based on photovoltaic direct drive. The system comprises a solar heat collection system, a buffer water tank, a cross-seasonal heat storage water body, a heat consumer, and a photovoltaic battery pack, a solar controller and a flow battery energy storage unit which are electrically connected in sequence. The solar heat collection system is connected with the buffer water tank through a pipeline provided with a first water pump; the solar controller is electrically connected with the first water pump and used for controlling the photovoltaic battery pack to drive the first water pump. The buffer water tank is connected with the heat user through a pipeline; the buffer water tank and the cross-seasonal heat storage water body are connected with the second plate heat exchanger through pipelines, and water bodies of the buffer water tank and the cross-seasonal heat storage water body exchange heat through the second plate heat exchanger. The multi-source heat storage mode is adopted, the energy-saving, practical and pollution-free requirements can be met, the heat supply stability can be guaranteed, the long-period heat storage and heat supply circulation is met, and the environmental pollution and energy consumption caused by traditional heat supply are reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of solar photovoltaic and photothermal utilization, and specifically to a cross-seasonal water body heat storage and heating system and method based on photovoltaic direct drive. Background Art

[0002] As the world's dependence on fossil fuels deepens, energy shortages, environmental pollution, and climate change are becoming more serious. To solve the above problems, the development of renewable energy has become the focus of the global energy strategy. As a clean and renewable energy source, solar energy has a wide range of application prospects. However, due to its intermittent and unstable nature, it is restricted by weather, region, and season, which limits the efficiency of solar energy utilization. The inter-seasonal water thermal storage system uses efficient heat storage technology to store heat in the summer in the autumn and winter seasons, realizing summer heat and winter use. It can not only improve the utilization rate of solar energy, but also provide a reliable solution for building heating, industrial heating, etc.

[0003] Solar photovoltaic power generation technology uses the photovoltaic effect to convert light energy into electrical energy to supply electrical equipment, and energy storage equipment can be used to store excess electrical energy. Liquid flow batteries are a new type of green electrochemical energy storage technology. They are very suitable for long-term energy storage due to their safety and stability, wide operating temperature range, low self-discharge rate, and power and energy decoupling. However, liquid flow batteries generate a lot of heat during operation. Excessive temperature will cause certain damage to the electrolyte, and directly releasing it into the air will cause energy waste.

[0004] Photovoltaic direct drive technology refers to the technology of directly driving DC motors with the DC power generated by photovoltaic cells. It eliminates the process of converting DC power into AC power using inverters in traditional photovoltaic power generation systems, reducing energy losses. Applying photovoltaic direct drive technology to solar thermal collection systems, using solar irradiance as start-stop and flow rate control signals, and providing energy sources for electrical equipment through the power generated by photovoltaic cells can reduce energy consumption, costs and improve system efficiency.

[0005] The operation of the water pump in the existing inter-seasonal water thermal storage system is not only affected by flow and temperature, but also by external environmental factors and the needs of heat users. However, the continuous adjustment of its operating status will lead to high energy consumption, and the real-time processing of multiple variables and ensuring the coordinated work of multiple components will lead to complex control logic. The heat generated during the charging and discharging process of the flow battery cannot be effectively recycled, resulting in energy waste. Summary of the invention

[0006] In order to overcome the shortcomings of the above-mentioned technology, the purpose of the present invention is to provide a cross-seasonal water body heat storage and heating system and method based on photovoltaic direct drive, to solve the problems of high energy consumption and energy waste in the existing cross-seasonal water body heat storage system, and adopt a multi-source heat storage method, which can not only meet the requirements of energy saving, practicality and pollution-free, but also ensure the stability of heating, meet the long-term heat storage and heating cycle, so as to reduce the environmental pollution and energy consumption caused by traditional heating.

[0007] To achieve the above purpose, the technical solution adopted by the present invention is as follows:

[0008] A photovoltaic direct-driven inter-seasonal water body heat storage heating system, which is special in that it includes a solar thermal collection system, a buffer water tank, an inter-seasonal hot water storage body, a heat user, and a photovoltaic battery group, a solar controller and a flow battery energy storage unit which are electrically connected in sequence;

[0009] The solar thermal collection system is connected to the buffer water tank through a pipeline provided with a first water pump, which is used to heat the low-temperature water from the buffer water tank through the solar thermal collection system and return it to the buffer water tank; the first water pump is a DC water pump; the solar controller is electrically connected to the first water pump, and is used to control the photovoltaic battery group to use the generated electricity to drive the first water pump, thereby controlling the working state of the solar thermal collection system;

[0010] The buffer water tank is connected to the heat user through a pipeline, and is used to provide high-temperature water for heating the heat user, and the low-temperature water after heating is returned to the buffer water tank;

[0011] The buffer water tank and the inter-seasonal hot water storage body are both connected to the second plate heat exchanger through a pipeline, and are used to return the water in the buffer water tank and the inter-seasonal hot water storage body to the buffer water tank and the inter-seasonal hot water storage body respectively after heat exchange through the second plate heat exchanger;

[0012] The solar controller is used to control the photovoltaic battery group to store the excess electrical energy generated into the liquid flow battery energy storage unit; the liquid flow battery energy storage unit is provided with a plate heat exchanger connected to the buffer water tank through a pipeline, which is used to exchange heat generated during the charging and discharging process with the water in the buffer water tank, thereby heating the water in the buffer water tank.

[0013] The present invention adopts a multi-source heat storage method, which is not only energy-saving, practical, and pollution-free, but also ensures the stability of heat supply and meets the long-term heat storage and heating cycle to reduce environmental pollution and energy consumption caused by traditional heating. The photovoltaic-driven DC water pump is used to directly control the working state of the solar thermal collection system, reducing the energy loss in the intermediate links and improving the overall energy efficiency of the system.

[0014] As a preferred embodiment, the inter-seasonal water heat storage and heating system also includes a water-air dual-source heat pump unit; the water-air dual-source heat pump unit is connected to the buffer water tank through a pipeline, which is used to transfer the heat absorbed by the water-air dual-source heat pump unit from the low-temperature water in the buffer water tank and / or the heat absorbed from the environment to the buffer water tank.

[0015] As a preferred embodiment, the water-air dual-source heat pump unit includes a first plate heat exchanger, an evaporator, a DC compressor, a second plate heat exchanger and an expansion valve which are sequentially connected through pipelines along the refrigerant flow direction, and the expansion valve is connected to the first plate heat exchanger through a pipeline; the refrigerant inlet of the evaporator is connected to the refrigerant outlet of the expansion valve through a pipeline provided with a valve; the refrigerant outlet of the first plate heat exchanger is connected to the refrigerant inlet of the DC compressor through a pipeline provided with a valve; the first plate heat exchanger is connected to the buffer water tank through a pipeline, and the refrigerant outlet of the first plate heat exchanger is connected to the refrigerant outlet of the second plate heat exchanger through a pipeline provided with a valve. The buffer water tank is used to exchange heat with the refrigerant of the water-air dual-source heat pump unit. The low-temperature water in the buffer water tank transfers heat to the refrigerant of the water-air dual-source heat pump unit and then returns to the buffer water tank. After the heat exchange, the refrigerant continues to pass through the DC compressor or evaporator and the DC compressor to absorb heat, and then exchanges heat with the low-temperature water in the buffer water tank in the second plate heat exchanger, transferring the heat of the refrigerant to the low-temperature water in the buffer water tank. The low-temperature water in the buffer water tank absorbs heat and returns to the buffer water tank. The refrigerant circulates in the pipeline of the water-air dual-source heat pump unit. With this connection method, the water source heat pump and the air source heat pump can be used independently. In different situations, one of them can be selected or both heat pumps can be used at the same time. Through multi-source heating, the stability of heating can be guaranteed, and a long-term heat storage and heating cycle can be met.

[0016] Furthermore, the evaporator, the DC compressor, the second plate heat exchanger and the expansion valve form an air source heat pump; the first plate heat exchanger, the DC compressor, the second plate heat exchanger and the expansion valve form a water source heat pump. The first plate heat exchanger is used as a heat pump heat exchanger to exchange heat between the refrigerant in the water-air dual-source heat pump unit and the low-temperature water in the buffer water tank; the evaporator is used to exchange heat between the refrigerant in the water-air dual-source heat pump unit and the air in the environment, and evaporate the liquid refrigerant in the water-air dual-source heat pump unit into a gaseous refrigerant; the DC compressor can pressurize and heat the gaseous refrigerant obtained by evaporation of the evaporator or the refrigerant after heat exchange by the first plate heat exchanger; the second plate heat exchanger is used to exchange heat between the high-temperature refrigerant obtained by the DC compressor and the low-temperature water in the buffer water tank, and can be used as a condenser to condense the gaseous refrigerant into a liquid refrigerant; the expansion valve is used to adjust the liquid flow and pressure in the pipeline. The water-air dual-source heat pump unit has the advantages of efficient heat exchange, compact structure, flexibility and scalability, energy saving and environmental protection, easy maintenance and wide application.

[0017] As a preferred solution, the solar controller is electrically connected to the DC compressor to control the photovoltaic battery group to generate electricity or control the flow battery energy storage unit to store electricity to drive the DC compressor, thereby controlling the working state of the water-air dual-source heat pump unit. The DC compressor is driven by the electricity provided by the photovoltaic cell, making full use of solar energy and reducing operating costs.

[0018] As a preferred embodiment, the liquid flow battery energy storage unit includes a positive electrode storage tank for storing positive electrode electrolyte, a negative electrode storage tank for storing negative electrode electrolyte, a battery stack for generating current through redox reaction, and a third plate heat exchanger and a fourth plate heat exchanger; the battery stack is respectively connected to the positive electrode storage tank, the negative electrode storage tank, the third plate heat exchanger and the fourth plate heat exchanger through pipelines; the third plate heat exchanger is respectively connected to the positive electrode storage tank and the buffer water tank through pipelines, so as to realize heat exchange between the positive electrode electrolyte and the water in the buffer water tank, and heat the water in the buffer water tank; the fourth plate heat exchanger is respectively connected to the negative electrode storage tank and the buffer water tank through pipelines, so as to realize heat exchange between the negative electrode electrolyte and the water in the buffer water tank, and heat the water in the buffer water tank. The use of liquid flow battery energy storage can effectively store the excess electricity generated by photovoltaic cells. At the same time, the heat generated by the liquid flow battery during the charging and discharging process can be collected and utilized, combining heat storage with battery thermal management to increase the overall thermal energy utilization efficiency of the system.

[0019] As a preferred solution, the inter-seasonal hot water storage body is provided with an electric heater for heating the inter-seasonal hot water storage body. The multi-level and multi-source heating mode is adopted to ensure the stability and reliability of the heating system.

[0020] As a preferred solution, the solar controller is electrically connected to the electric heater to control the photovoltaic battery group to generate electricity or control the flow battery energy storage unit to store electricity to drive the electric heater, thereby controlling the working state of the electric heater. Using solar energy to power the electric heater is energy-saving, practical and pollution-free.

[0021] As a preferred embodiment, a first valve and a first water pump are provided on the pipeline between the solar thermal collection system and the buffer water tank; a second valve and a second water pump are provided on the pipeline between the liquid flow battery energy storage unit and the buffer water tank; a third valve and a third water pump are provided on the pipeline between the buffer water tank and the heat user; a fourth valve and a fourth water pump are provided on the pipeline between the second plate heat exchanger and the buffer water tank; a fifth valve and a fifth water pump are provided on the pipeline between the first plate heat exchanger and the buffer water tank; an eighth valve and a sixth water pump are provided on the pipeline between the second plate heat exchanger and the inter-seasonal hot water storage body; a seventh water pump is provided on the pipeline between the positive electrode liquid storage tank and the battery stack; an eighth water pump is provided on the pipeline between the negative electrode liquid storage tank and the battery stack; a ninth valve is provided on the pipeline between the expansion valve and the first plate heat exchanger; and a tenth valve is provided on the pipeline between the evaporator and the first plate heat exchanger.

[0022] Furthermore, the evaporator is connected to the expansion valve via a pipeline provided with a seventh valve; and the first plate heat exchanger is connected to the DC compressor via a pipeline provided with a sixth valve.

[0023] The present invention also discloses a cross-seasonal water body heat storage and heating method based on photovoltaic direct drive, which is special in that it includes: collecting heat through a solar thermal collection system and a photovoltaic battery group, and storing heat in a cross-seasonal hot water storage body; heating the water body in a buffer water tank through one or more of a solar thermal collection system, a liquid flow battery energy storage unit, a cross-seasonal hot water storage body, a water body-air dual-source heat pump unit, and an electric heater, and when the water temperature in the buffer water tank reaches a set temperature, heating is provided to heat users; the water body-air dual-source heat pump unit includes an air source heat pump and a water source heat pump.

[0024] As a preferred solution, the cross-seasonal water body heat storage and heating method based on photovoltaic direct drive includes:

[0025] (1) Non-heating season

[0026] The photovoltaic battery group drives the first water pump of the solar thermal collection system to start the solar thermal collection system; the solar thermal collection system and the liquid flow battery energy storage unit are used to heat the buffer water tank; when the high-temperature water in the buffer water tank is overheated, the buffer water tank is heat-exchanged with the inter-seasonal hot water storage body through the second plate heat exchanger, and the heat is transferred to the inter-seasonal hot water storage body for thermal energy storage; at the same time, the photovoltaic battery group stores the excess electrical energy generated in the liquid flow battery energy storage unit;

[0027] (2) Heating season

[0028] a. Heat the buffer water tank through the solar thermal collection system and the liquid flow battery energy storage unit. If the water temperature in the buffer water tank can meet the water temperature requirement for heating the heat user, the heat in the buffer water tank is directly transferred to the heat user;

[0029] b. If the water temperature in the buffer water tank cannot meet the water temperature requirement for heating the heat users, the buffer water tank is heated by the solar thermal collection system, the flow battery energy storage unit, and the inter-seasonal hot water storage body at the same time, and the heat is supplied to the heat users through the buffer water tank;

[0030] c. If the temperature of the buffer water tank supplied by the solar thermal collection system, liquid flow battery energy storage unit, or inter-seasonal hot water storage body cannot meet the water temperature requirements for heating users, the air source heat pump is turned on to provide auxiliary heating;

[0031] d. If the solar thermal system, liquid flow battery energy storage unit, cross-seasonal hot water storage body and air source heat pump auxiliary heating still cannot meet the water temperature requirements, then turn on the water source and air source dual source heat pump auxiliary heating;

[0032] e. When the air source heat pump cannot extract heat from the low-temperature air, turn off the air source heat pump, keep only the water source heat pump in working mode, and turn on the electric heater for auxiliary heating.

[0033] As a preferred solution, the heating method of the solar thermal collection system includes: when the output power of the photovoltaic cell group is greater than the starting power of the first water pump used to start the solar thermal collection system heat collection cycle, the circuit between the photovoltaic cell and the first water pump is connected, that is, the solar thermal collection cycle is started; the heat collected by the solar thermal collection system is transferred to the buffer water tank to heat the water in the buffer water tank;

[0034] The heat supply method of the liquid flow battery energy storage unit comprises: transferring the heat generated during the charging and discharging process in the liquid flow battery energy storage unit to the buffer water tank through the third plate heat exchanger and the fourth plate heat exchanger to heat the water in the buffer water tank;

[0035] The heating method of the inter-seasonal hot water storage body comprises: the inter-seasonal hot water storage body exchanges heat with the water in the buffer water tank through the second plate heat exchanger, and transfers heat to the water in the buffer water tank;

[0036] The air source heat pump heating method comprises: starting the operation of the DC compressor by using the electric energy generated by the photovoltaic battery group or the electric energy stored in the flow battery energy storage unit, and the second plate heat exchanger is used as a condenser to heat the heat in the air through the evaporator and the DC compressor, and then transfer the heat to the buffer water tank through the second plate heat exchanger;

[0037] The heating method of the water-air dual-source heat pump comprises: a first plate heat exchanger uses low-temperature water in a buffer water tank as a heat source to transfer heat to a refrigerant in a water-air dual-source heat pump unit for primary heat collection; the refrigerant in the first plate heat exchanger then passes through an evaporator and a DC compressor for secondary heat collection, and transfers the heat to the buffer water tank through a second plate heat exchanger;

[0038] The water source heat pump heating method comprises: a first plate heat exchanger uses low temperature water in a buffer water tank as a heat source to perform heat exchange and transfer heat to a refrigerant in a water-air dual-source heat pump unit; the refrigerant after heat exchange is processed by a DC compressor and then transfers heat to the buffer water tank through a second plate heat exchanger;

[0039] The heating method of the electric heater includes: starting the electric heater by using the electric energy generated by the photovoltaic battery group or the electric energy stored in the liquid flow battery energy storage unit to heat the inter-seasonal hot water storage body, and the inter-seasonal hot water storage body transfers heat to the buffer water tank through the second plate heat exchanger.

[0040] Compared with the prior art, the present invention has the following beneficial effects:

[0041] The present invention adopts a multi-source heat storage method, which is not only energy-saving, practical and pollution-free, but also can ensure the stability of heating and meet the long-term heat storage and heating cycle to reduce environmental pollution and energy consumption caused by traditional heating.

[0042] (1) High energy utilization efficiency. The photovoltaic-driven DC water pump is used to directly control the working state of the solar thermal collection system, reducing energy loss in the intermediate links and improving the overall energy efficiency of the system.

[0043] (2) The use of liquid flow battery energy storage can effectively store the excess electricity generated by photovoltaic cells. At the same time, the heat generated by the liquid flow battery during the charging and discharging process can be collected and utilized, combining heat storage with battery thermal management to increase the overall thermal energy utilization efficiency of the system.

[0044] (3) Directly supply heat to heat users through the buffer water tank, effectively alleviating thermal fluctuations and providing a more stable and continuous supply of high-temperature water.

[0045] (4) The use of a closed cross-seasonal hot water storage structure helps reduce heat dissipation and heat loss, while reducing the risk of water pollution and improving system stability and reliability.

[0046] (5) The dual-source heat pump that combines air source and water source can dynamically adjust the working mode according to changes in environmental conditions, thereby improving the flexibility and efficiency of heating, while also ensuring the operation of the system in a low-temperature environment.

[0047] (6) The electricity provided by photovoltaic cells drives the DC compressor and electric heater, which reduces the operating cost and the consumption of non-renewable energy and is environmentally friendly. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 This is a structural principle diagram of a cross-seasonal water body heat storage and heating system based on photovoltaic direct drive according to the present invention;

[0049] Figure 2 It is a schematic diagram of the internal structure of the liquid flow battery heat storage unit;

[0050] Figure 3 for Figure 1 Operational principle diagram of the heat storage mode of the mid-season water body heat storage heating system;

[0051] Figure 4 for Figure 1 The operating principle diagram of the auxiliary heating mode of the air source heat pump;

[0052] Figure 5 for Figure 1 Operation principle diagram of water-air dual-source heat pump auxiliary heating mode;

[0053] Figure 6 for Figure 1 Operational principle diagram of water source heat pump and electric heater auxiliary heating mode;

[0054] In the figure: 1: photovoltaic battery group; 2: solar thermal collection system; 3: solar controller; 4: liquid flow battery energy storage unit; 5: buffer water tank; 6: heat user; 7: first plate heat exchanger; 8: evaporator; 9: DC compressor; 10: second plate heat exchanger; 11: expansion valve; 12: electric heater; 13: inter-seasonal hot water storage body; 14: positive electrode storage tank; 15: battery stack; 16: negative electrode storage tank; 17: third plate heat exchanger; 18: fourth plate heat exchanger; P-1~8: first water pump~eighth water pump; V-1~10: first valve~tenth valve; T-1~12: first pipeline~twelfth pipeline. DETAILED DESCRIPTION

[0055] In order to better explain the present invention, the main contents of the present invention are further explained below in conjunction with specific embodiments, but the contents of the present invention are not limited to the following embodiments.

[0056] Example 1

[0057] like Figure 1As shown, a cross-seasonal water body heat storage and heating system based on photovoltaic direct drive of the present invention includes a solar thermal collection system 2, a buffer water tank 5, a water-air dual-source heat pump unit, a cross-seasonal hot water storage body 13, a heat user 6, a photovoltaic battery group 1, a solar controller 3 and a liquid flow battery energy storage unit 4; the solar thermal collection system 2 is connected to the buffer water tank 5 through a pipeline, which is used to return the low-temperature water from the buffer water tank 5 to the buffer water tank 5 after being heated by the solar thermal collection system 2; the buffer water tank 5 is connected to the heat user 6 through a pipeline, which is used to provide high-temperature water for heating to the heat user 6, and the low-temperature water after heating is returned to the buffer water tank 5; the water-air dual-source heat pump unit is connected to the buffer water tank 5 through a pipeline, which is used to absorb the water-air dual-source heat pump unit from the low-temperature water in the buffer water tank 5 The heat generated and / or the heat absorbed from the environment is transferred to the buffer water tank 5; the buffer water tank 5 and the inter-seasonal hot water storage body 13 are connected to the second plate heat exchanger 10 through a pipeline, which is used to return the water in the buffer water tank 5 and the inter-seasonal hot water storage body 13 to the buffer water tank 5 and the inter-seasonal hot water storage body 13 respectively after heat exchange through the second plate heat exchanger 10; the photovoltaic battery group 1, the solar controller 3 and the liquid flow battery energy storage unit 4 are electrically connected in sequence, and the solar controller 3 is used to control the photovoltaic battery group 1 to store the excess electric energy generated in the liquid flow battery energy storage unit 4; the liquid flow battery energy storage unit 4 is provided with a plate heat exchanger connected to the buffer water tank 5 through a pipeline, which is used to exchange the heat generated during the charging and discharging process with the water in the buffer water tank 5, and heat the water from the buffer water tank 5.

[0058] The water-air dual-source heat pump unit includes a first plate heat exchanger 7, an evaporator 8, a DC compressor 9, a second plate heat exchanger 10 and an expansion valve 11 which are sequentially connected through pipelines along the refrigerant flow direction, and the expansion valve 11 is connected to the first plate heat exchanger 7 through a pipeline; the refrigerant inlet of the evaporator 8 is connected to the refrigerant outlet of the expansion valve 11 through a pipeline provided with a valve; the refrigerant outlet of the first plate heat exchanger 7 is connected to the refrigerant inlet of the DC compressor 9 through a pipeline provided with a valve; the first plate heat exchanger 7 is connected to the buffer water tank 5 through a pipeline for transferring the buffer water to the refrigerant outlet of the expansion valve 11; the refrigerant outlet of the first plate heat exchanger 7 is connected to the refrigerant inlet of the DC compressor 9 through a pipeline provided with a valve; the first plate heat exchanger 7 is connected to the buffer water tank 5 through a pipeline for transferring the buffer water to the refrigerant outlet of the expansion valve 11; the refrigerant outlet of the first plate heat exchanger 7 is connected to the refrigerant outlet of the expansion valve 11 through a pipeline provided with a valve; the refrigerant outlet of the first plate heat exchanger 7 is connected to the refrigerant outlet ... expansion valve 11 through a pipeline provided with a valve; the refrigerant outlet of the first plate heat exchanger 7 is connected to the refrigerant outlet of the expansion valve 1 The water tank 5 exchanges heat with the liquid refrigerant of the water-air dual-source heat pump unit. The low-temperature water in the buffer water tank 5 transfers heat to the liquid refrigerant of the water-air dual-source heat pump unit and then returns to the buffer water tank 5. The liquid refrigerant passes through the DC compressor 9 or the evaporator 8 and the DC compressor 9 and absorbs heat before exchanging heat with the low-temperature water from the buffer water tank 5 in the second plate heat exchanger 10, transferring the heat of the refrigerant to the low-temperature water in the buffer water tank 5. The low-temperature water in the buffer water tank 5 absorbs heat before returning to the buffer water tank 5, and the refrigerant circulates in the pipeline of the water-air dual-source heat pump unit.

[0059] Among them, three sets of pipeline inlets and outlets are arranged on the second plate heat exchanger 10, which are respectively used to connect the buffer water tank 5, the internal circulation of the water-air dual-source heat pump unit, and the cross-seasonal hot water storage body 13.

[0060] The evaporator 8, the DC compressor 9, the second plate heat exchanger 10, and the expansion valve 11 form an air source heat pump; the first plate heat exchanger 7, the DC compressor 9, the second plate heat exchanger 10, and the expansion valve 11 form a water source heat pump. The first plate heat exchanger 7 is used as a heat pump heat exchanger to exchange heat between the refrigerant in the water-air dual-source heat pump unit and the low-temperature water in the buffer water tank 5; the evaporator 8 is used to exchange heat between the refrigerant in the water-air dual-source heat pump unit and the air in the environment, and evaporate the liquid refrigerant in the water-air dual-source heat pump unit into a gaseous refrigerant; the DC compressor 9 can pressurize and heat the gaseous refrigerant evaporated by the evaporator 8 or the refrigerant after heat exchange by the first plate heat exchanger 7; the second plate heat exchanger 10 exchanges heat between the high-temperature refrigerant obtained by the DC compressor 9 and the low-temperature water in the buffer water tank 5, and can be used as a condenser to condense the gaseous refrigerant into a liquid refrigerant; the expansion valve 11 is used to adjust the liquid flow and pressure in the pipeline.

[0061] A first water pump P-1 is arranged on the pipeline between the solar thermal collection system 2 and the buffer water tank 5; the first water pump P-1 is a DC water pump; the solar controller 3 is electrically connected to the first water pump P-1, and is used to control the photovoltaic cell group 1 to generate electric energy to drive the first water pump P-1, thereby controlling the working state of the solar thermal collection system 2.

[0062] The solar controller 3 is electrically connected to the DC compressor 9 and is used to control the photovoltaic cell group 1 to generate electric energy or control the liquid flow battery energy storage unit 4 to store electric energy to drive the DC compressor 9, thereby controlling the working state of the water-air dual-source heat pump unit.

[0063] like Figure 2As shown, the liquid flow battery energy storage unit 4 includes a positive electrode storage tank 14 for storing positive electrode electrolyte, a negative electrode storage tank 16 for storing negative electrode electrolyte, a battery stack 15 for generating current through redox reaction, and a third plate heat exchanger 17 and a fourth plate heat exchanger 18; the battery stack 15 is respectively connected to the positive electrode storage tank 14, the negative electrode storage tank 16, the third plate heat exchanger 17 and the fourth plate heat exchanger 18 through pipelines; the third plate heat exchanger 17 is respectively connected to the positive electrode storage tank 14 and the buffer water tank 5 through pipelines, so as to realize heat exchange between the positive electrode electrolyte and the water in the buffer water tank 5, and heat the water in the buffer water tank 5; the fourth plate heat exchanger 18 is respectively connected to the negative electrode storage tank 16 and the buffer water tank 5 through pipelines, so as to realize heat exchange between the negative electrode electrolyte and the water in the buffer water tank 5, and heat the water in the buffer water tank 5. Among them, a seventh water pump P- 7 is provided on the pipeline between the positive electrode liquid storage tank 14 and the battery stack 15 ; an eighth water pump P- 8 is provided on the pipeline between the negative electrode liquid storage tank 16 and the battery stack 15 .

[0064] The inter-seasonal hot water storage body 13 is provided with an electric heater 12 for heating the inter-seasonal hot water storage body 13. The solar controller 3 is electrically connected to the electric heater 12, and uses the electric energy generated by the photovoltaic battery group 1 or the electric energy stored in the flow battery energy storage unit 4 to drive the electric heater 12, thereby controlling the working state of the electric heater 12.

[0065] Specifically, the high-temperature water outlet of the solar thermal collection system 2 is connected to the high-temperature water inlet of the buffer water tank 5 through the first pipe T-1, and a first water pump P-1 is arranged on the first pipe T-1; the low-temperature water inlet of the solar thermal collection system 2 is connected to the first low-temperature water outlet of the buffer water tank 5 through the second pipe T-2, and a first valve V-1 is arranged on the second pipe T-2.

[0066] Solar thermal collection cycle: the first low-temperature water outlet of the buffer water tank 5, the second pipeline T-2, the first valve V-1, the solar thermal collection system 2, the first pipeline T-1, the first water pump P-1, and the high-temperature water inlet of the buffer water tank 5 are connected in sequence to form a solar thermal collection cycle, and the solar thermal collection system 2 is used to supply heat to the buffer water tank 5.

[0067] The high-temperature water outlet of the buffer water tank 5 is connected to the high-temperature water inlet of the heat user 6 through a third pipe T-3, and a third valve V-3 is arranged on the third pipe T-3; the low-temperature water outlet of the heat user 6 is connected to the first low-temperature water inlet of the buffer water tank 5 through a fourth pipe T-4, and a third water pump P-3 is arranged on the fourth pipe T-4.

[0068] Heat user heating cycle: the high-temperature water outlet of the buffer water tank 5, the third pipeline T-3, the third valve V-3, the heat user 6, the fourth pipeline T-4, the third water pump P-3, and the first low-temperature water inlet of the buffer water tank 5 are connected in sequence to form a heat user heating cycle, and heat is supplied to the heat user 6 through the buffer water tank 5.

[0069] The buffer water tank 5 is also provided with a high-temperature water inlet and outlet and a low-temperature water inlet and outlet, which are respectively connected to the inlets and outlets at both ends of the second plate heat exchanger 10 through the fifth pipeline T-5 and the sixth pipeline T-6, and the fifth pipeline T-5 is provided with a fourth valve V-4 and a fourth water pump P-4; the inter-seasonal hot water storage body 13 is provided with a high-temperature water inlet and outlet and a low-temperature water inlet and outlet, which are respectively connected to the other two inlets and outlets at both ends of the second plate heat exchanger 10 through the seventh pipeline T-7 and the eighth pipeline T-8, and the eighth pipeline T-8 is provided with a sixth water pump P-6 and an eighth valve V-8.

[0070] Buffer water tank heating cycle: When the high-temperature water in the buffer water tank 5 flows out from the high-temperature water inlet and outlet of the buffer water tank 5, passes through the fifth pipeline T-5, the fourth valve V-4, the fourth water pump P-4, the second plate heat exchanger 10, and the sixth pipeline T-6, and returns to the buffer water tank 5 through the low-temperature water inlet and outlet of the buffer water tank 5, a buffer water tank heating cycle is formed.

[0071] Inter-seasonal hot water storage body heat storage cycle: When the low-temperature water of the inter-seasonal hot water storage body 13 flows out from the low-temperature water inlet and outlet of the inter-seasonal hot water storage body 13, returns to the high-temperature water inlet and outlet of the inter-seasonal hot water storage body 13 through the eighth pipeline T-8, the sixth water pump P-6, the eighth valve V-8, the second plate heat exchanger 10, and the seventh pipeline T-7, an inter-seasonal hot water storage body heat storage cycle is formed.

[0072] The buffer water tank heating cycle and the inter-seasonal hot water storage body heat storage cycle provide the heat of the buffer water tank 5 to the inter-seasonal hot water storage body 13 for heat storage.

[0073] Buffer water tank heat storage cycle: The flow direction is opposite to the buffer water tank heat supply cycle. When the low-temperature water in the buffer water tank 5 flows out from the low-temperature water inlet and outlet of the buffer water tank 5 and returns to the buffer water tank 5 through the high-temperature water inlet and outlet of the buffer water tank 5 via pipes, valves, etc., a buffer water tank heat storage cycle is formed.

[0074] Inter-seasonal hot water storage body heating cycle: The flow direction is opposite to that of the inter-seasonal hot water storage body heat storage cycle. When high-temperature water flows out from the high-temperature water inlet and outlet of the inter-seasonal hot water storage body 13, and returns to the inter-seasonal hot water storage body 13 through the seventh pipeline T-7, the second plate heat exchanger 10, the eighth pipeline T-8, the sixth water pump P-6, the eighth valve V-8, and the low-temperature water inlet and outlet of the inter-seasonal hot water storage body 13, an inter-seasonal hot water storage body heating cycle is formed.

[0075] The buffer water tank heat storage cycle and the inter-seasonal hot water storage body heating cycle provide the heat of the inter-seasonal hot water storage body 13 to the buffer water tank 5 for heating.

[0076] When storing heat through the inter-seasonal hot water storage body 13, the high-temperature water in the buffer water tank 5 passes through its high-temperature water inlet and outlet and enters the second plate heat exchanger 10 via the fifth pipe T-5. The low-temperature water in the inter-seasonal hot water storage body 13 passes through its low-temperature water inlet and outlet and enters the second plate heat exchanger 10 via the eighth pipe T-8. After the high-temperature water from the buffer water tank 5 and the low-temperature water from the inter-seasonal hot water storage body 13 are heat exchanged in the second plate heat exchanger 10, the high-temperature water from the buffer water tank 5 becomes low-temperature water, and the low-temperature water returns to the buffer water tank 5 through the low-temperature water inlet and outlet of the buffer water tank 5 via the sixth pipe T-6. The low-temperature water from the inter-seasonal hot water storage body 13 becomes high-temperature water, and the high-temperature water returns to the inter-seasonal hot water storage body 13 through the high-temperature water inlet and outlet of the inter-seasonal hot water storage body 13 via the seventh pipe T-7.

[0077] When the inter-seasonal hot water storage body 13 is used for heating, the low-temperature water in the buffer water tank 5 passes through its low-temperature water inlet and outlet and enters the second plate heat exchanger 10 via the sixth pipe T-6. The high-temperature water in the inter-seasonal hot water storage body 13 passes through its high-temperature water inlet and outlet and enters the second plate heat exchanger 10 via the seventh pipe T-7. After the low-temperature water from the buffer water tank 5 and the high-temperature water from the inter-seasonal hot water storage body 13 are heat exchanged in the second plate heat exchanger 10, the low-temperature water from the buffer water tank 5 becomes high-temperature water, and the high-temperature water returns to the buffer water tank 5 through the high-temperature water inlet and outlet of the buffer water tank 5 via the fifth pipe T-5. The high-temperature water from the inter-seasonal hot water storage body 13 becomes low-temperature water, and the low-temperature water returns to the inter-seasonal hot water storage body 13 through the low-temperature water inlet and outlet of the inter-seasonal hot water storage body 13 via the eighth pipe T-8.

[0078] The first low-temperature water outlet of the buffer water tank 5 is also connected to the low-temperature water inlet of the liquid flow battery energy storage unit 4 through the eleventh pipeline T-11, and a second valve V-2 is arranged on the eleventh pipeline T-11; the high-temperature water outlet of the liquid flow battery energy storage unit 4 is connected to the high-temperature water inlet of the buffer water tank 5 through the twelfth pipeline T-12, and a second water pump P-2 is arranged on the twelfth pipeline T-12.

[0079] Heat supply cycle of liquid flow battery energy storage unit: the first low-temperature water outlet of the buffer water tank 5, the eleventh pipeline T-11, the second valve V-2, the liquid flow battery energy storage unit 4, the twelfth pipeline T-12, the second water pump P-2, and the high-temperature water inlet of the buffer water tank 5 are connected in sequence to form a heat supply cycle of the liquid flow battery energy storage unit, and the heat generated during the charging and discharging process of the liquid flow battery energy storage unit is used to exchange heat with the water in the buffer water tank 5. Specifically, the low-temperature water of the buffer water tank 5 flows out from the first low-temperature water outlet, passes through the eleventh pipeline T-11 and the second valve V-2, and is then diverted by the diverter, and enters the third plate heat exchanger 17 and the fourth plate heat exchanger 18 respectively to exchange heat with the positive electrolyte and the negative electrolyte, and then merges into the twelfth pipeline T-12, and returns to the buffer water tank 5 through the second water pump P-2 and the high-temperature water inlet of the buffer water tank 5.

[0080] The second low-temperature water outlet and the second low-temperature water inlet of the buffer water tank 5 are connected to the two ends of the first plate heat exchanger 7 through the ninth pipeline T-9 and the tenth pipeline T-10 respectively. The fifth valve V-5 and the fifth water pump P-5 are arranged on the ninth pipeline T-9; when the fifth valve V-5 and the fifth water pump P-5 are opened, the low-temperature water in the buffer water tank 5 exchanges heat with the refrigerant in the water-air dual-source heat pump unit in the first plate heat exchanger 7 and then returns to the buffer water tank 5.

[0081] The refrigerant inlet of the evaporator 8 is connected to the refrigerant outlet of the first plate heat exchanger 7 through a pipeline provided with a tenth valve V-10, the refrigerant outlet of the evaporator 8 is connected to the refrigerant inlet of the DC compressor 9 through a pipeline, the refrigerant outlet of the DC compressor 9 is connected to the refrigerant inlet of the second plate heat exchanger 10 through a pipeline, the refrigerant outlet of the second plate heat exchanger 10 is connected to the refrigerant inlet of the expansion valve 11 through a pipeline provided with a ninth valve V-9, and the refrigerant outlet of the expansion valve 11 is connected to the refrigerant inlet of the first plate heat exchanger 7. The refrigerant inlet of the evaporator 8 is also connected to the refrigerant outlet of the expansion valve 11 through a pipeline provided with a seventh valve V-7; the refrigerant outlet of the first plate heat exchanger 7 is connected to the refrigerant inlet of the DC compressor 9 through a pipeline provided with a sixth valve V-6.

[0082] Air source heat pump heating cycle: the refrigerant outlet of the evaporator 8, the DC compressor 9, the second plate heat exchanger 10, the expansion valve 11, the seventh valve V-7, and the refrigerant inlet of the evaporator 8 are connected in sequence through pipelines to form an air source heat pump heating cycle, which transfers the heat in the environment to the refrigerant and then to the buffer water tank 5 through the second plate heat exchanger 10.

[0083] Water source heat pump heating cycle: the refrigerant outlet of the first plate heat exchanger 7, the sixth valve V-6, the DC compressor 9, the second plate heat exchanger 10, the expansion valve 11, the ninth valve V-9, and the refrigerant inlet of the first plate heat exchanger 7 are connected in sequence through pipelines to form a water source heat pump heating cycle. The heat of the low-temperature water in the buffer water tank 5 is transferred to the refrigerant through the first plate heat exchanger 7, and then transferred to the buffer water tank 5 through the second plate heat exchanger 10 after being processed by the DC compressor 9.

[0084] Embodiment 2:

[0085] A cross-seasonal water body heat storage and heating method based on photovoltaic direct drive is implemented by the cross-seasonal water body heat storage and heating system based on photovoltaic direct drive in Example 1, including: collecting heat through a solar thermal collection system 2 and a liquid flow battery energy storage unit 4, and storing heat in an cross-seasonal hot water storage body 13; heating the water body in a buffer water tank 5 through the solar thermal collection system 2, the liquid flow battery energy storage unit 4, the cross-seasonal hot water storage body 13, an air source heat pump, a water body-air dual-source heat pump unit, and an electric heater 12, and heating a heat user 6 when the water temperature in the buffer water tank 5 reaches a set temperature; the water body-air dual-source heat pump unit includes an air source heat pump and a water source heat pump.

[0086] The above method specifically includes:

[0087] 1. Non-heating season

[0088] In the non-heating season, the heat of the solar thermal collection system 2 and the flow battery energy storage unit 4 is stored in the inter-seasonal hot water storage body 13 .

[0089] like Figure 3 As shown, throughout the year, when the solar irradiance increases to a certain value, that is, the output power of the photovoltaic cell group 1 is greater than the starting power of the DC water pump, the circuit between the photovoltaic cell 1 and the DC water pump is open, and the solar thermal collection cycle is started, that is, the first water pump P-1 and the first valve V-1 are turned on, and the heat collected by the solar thermal collection system 2 is transferred to the buffer water tank 5 to heat the water in the buffer water tank 5.

[0090] At the same time, the solar controller 3 controls the photovoltaic battery group 1 to store the excess electric energy generated into the liquid flow battery energy storage unit 4. The heat supply cycle of the liquid flow battery energy storage unit is started, and the second water pump P-2 and the second valve V-2 are turned on. When the liquid flow battery energy storage unit 4 is charged and discharged, the heat generated during the discharge process is transferred to the buffer water tank 5 through the third plate heat exchanger 17 and the fourth plate heat exchanger 18 to heat the water in the buffer water tank 5.

[0091] When the water in the buffer water tank 5 is overheated, the fourth valve V-4 and the eighth valve V-8 are opened, the fourth water pump P-4 and the sixth water pump P-6 are started, and the buffer water tank heating cycle and the inter-seasonal hot water storage body heat storage cycle are started; the buffer water tank 5 is heat exchanged with the inter-seasonal hot water storage body 13 through the second plate heat exchanger 10, and the heat in the buffer water tank 5 is transferred to the inter-seasonal hot water storage body 13 for thermal energy storage.

[0092] 2. The heating method in the heating season includes the following steps:

[0093] a. The solar energy collection cycle and the flow battery energy storage unit heating cycle provide heat simultaneously.

[0094] When the output power of the photovoltaic battery group 1 is greater than the starting power of the first water pump P-1 used to start the heat collection cycle of the solar thermal collection system 2, the first water pump P-1 is started by the electric energy generated by the photovoltaic battery group 1, the first valve V-1 is opened, and the solar thermal collection cycle is started. The water in the buffer water tank 5 is heated by the solar thermal collection system 2. If the water temperature in the buffer water tank 5 can meet the water temperature requirement for heating the heat user 6, the heat user heating cycle is started, the third valve V-3 is opened, and the third water pump P-3 is started to directly transfer heat to the heat user 6. At the same time, the liquid flow battery energy storage unit heating cycle is started, and the liquid flow battery energy storage unit 4 heats the buffer water tank 5 through the third plate heat exchanger 17 and the fourth plate heat exchanger 18.

[0095] b. Combined heating by solar energy collection cycle, liquid flow battery energy storage unit heating cycle, and cross-seasonal hot water storage body heating cycle.

[0096] If the water temperature in the buffer water tank 5 cannot meet the water temperature requirement for heating the heat user 6, then based on step a, the buffer water tank heat storage cycle and the inter-seasonal hot water storage body heating cycle are started. The fourth valve V-4 and the eighth valve V-8 are opened, the fourth water pump P-4 and the sixth water pump P-6 are started, and the heat in the inter-seasonal hot water storage body 13 is transferred to the water in the buffer water tank 5 through the second plate heat exchanger 10, and the third valve V-3 is opened, the third water pump P-3 is started, and the heat user heating cycle is started, and the stored heat is transferred from the buffer water tank 5 to the heat user 6.

[0097] c. Combined heating of solar thermal collection cycle, liquid flow battery energy storage unit heating cycle, cross-seasonal hot water storage body heating cycle, and air source heat pump heating cycle.

[0098] like Figure 4As shown, in the late heating season, when the temperature of the cross-seasonal hot water storage body 13 cannot meet the water temperature requirement for heating the heat user 6, based on step b, the air source heat pump auxiliary heating is performed, that is, the air source heat pump heating cycle is started. The DC compressor 9 is started by the electric energy generated by the photovoltaic battery group 1 or the electric energy stored in the liquid flow battery energy storage unit 4, the seventh valve V-7 is opened, and the expansion valve 11 is opened, that is, the air source heat pump is running, and the second plate heat exchanger 10 acts as a condenser to transfer the heat absorbed from the air to the buffer water tank 5, and the heat user heating cycle is started.

[0099] d. Solar energy collection cycle, liquid flow battery energy storage unit heating cycle, cross-seasonal hot water storage body heating cycle, and water source and air source dual-source heat pump combined heating.

[0100] If the air source heat pump auxiliary heating still cannot meet the water temperature requirement, then based on step c, open the fifth valve V-5 and the fifth water pump P-5, close the seventh valve V-7, open the ninth valve V-9 and the tenth valve V-10, that is, start the water source and air source dual source heat pump operation. Figure 5 As shown, the refrigerant in the first plate heat exchanger 7 uses the low-temperature water in the buffer water tank 5 as a low-temperature heat source to absorb the heat of the low-temperature water for the first step of heat collection, and then passes through the evaporator 8 for secondary heat collection to absorb heat in the environment, and transfers the heat to the buffer water tank 5 through the second plate heat exchanger 10, opens the third valve V-3, starts the third water pump P-3, starts the heat user heating cycle, and delivers the hot water in the buffer water tank 5 to the heat user 6.

[0101] e. Solar thermal collection cycle, liquid flow battery energy storage unit heating cycle, cross-seasonal hot water storage body heating cycle, water source heat pump heating cycle, and electric heater combined heating.

[0102] like Figure 6 As shown, when the ambient temperature drops to a very low level, the air source heat pump cannot extract enough heat from the low-temperature air, and its efficiency is low and its energy consumption is high. Based on step d, the tenth valve V-10 is closed and the sixth valve V-6 is opened, so that only the water source heat pump is in working mode. Generally, the water temperature requirement cannot be met at this time, so it is necessary to use the electricity generated by the photovoltaic battery group 1 or the electricity stored in the liquid flow battery energy storage unit 4 to turn on the electric heater 12 to assist in heating the inter-seasonal hot water storage body 13, turn on the sixth water pump P-6, the eighth valve V-8, the fourth water pump P-4, and the fourth valve V-4, and the inter-seasonal hot water storage body 13 transfers heat to the buffer water tank 5 through the second plate heat exchanger 10, and starts the heat user heating cycle to provide heat for the heat user 6.

[0103] Other parts not described belong to the prior art.

Claims

1. A cross-seasonal water body heat storage and heating system based on photovoltaic direct drive, characterized by: It comprises a solar thermal collection system (2), a buffer water tank (5), a cross-seasonal hot water storage body (13), a heat user (6), and a photovoltaic battery group (1), a solar energy controller (3) and a flow battery energy storage unit (4) which are electrically connected in sequence; The solar thermal collection system (2) is connected to the buffer water tank (5) via a pipeline provided with a first water pump (P-1), which is used to heat low-temperature water from the buffer water tank (5) through the solar thermal collection system (2) and then return it to the buffer water tank (5); the first water pump (P-1) is a DC water pump; the solar controller (3) is electrically connected to the first water pump (P-1), and is used to control the photovoltaic cell group (1) to use the generated electrical energy to drive the first water pump (P-1), thereby controlling the working state of the solar thermal collection system (2); The buffer water tank (5) is connected to the heat user (6) via a pipeline, and is used to provide high-temperature water for the heat user (6) for heating, and the low-temperature water after heating is returned to the buffer water tank (5); The buffer water tank (5) and the inter-seasonal hot water storage body (13) are both connected to the second plate heat exchanger (10) through a pipeline, and are used to return the water in the buffer water tank (5) and the inter-seasonal hot water storage body (13) to the buffer water tank (5) and the inter-seasonal hot water storage body (13) respectively after heat exchange through the second plate heat exchanger (10); The solar controller (3) is used to control the photovoltaic battery group (1) to store the excess electric energy generated in the liquid flow battery energy storage unit (4); the liquid flow battery energy storage unit (4) is provided with a plate heat exchanger connected to the buffer water tank (5) through a pipeline, and is used to exchange heat generated during the charging and discharging process with the water in the buffer water tank (5), thereby heating the water in the buffer water tank (5).

2. The inter-seasonal water body heat storage and heating system according to claim 1 is characterized in that: It also includes a water-air dual-source heat pump unit; the water-air dual-source heat pump unit is connected to the buffer water tank (5) through a pipeline, and is used to transfer the heat absorbed by the water-air dual-source heat pump unit from the low-temperature water in the buffer water tank (5) and / or the heat absorbed from the environment to the buffer water tank (5).

3. The inter-seasonal water body heat storage and heating system according to claim 2 is characterized in that: The water-air dual-source heat pump unit comprises a first plate heat exchanger (7), an evaporator (8), a DC compressor (9), a second plate heat exchanger (10) and an expansion valve (11) which are connected in sequence through pipelines along the refrigerant flow direction, and the expansion valve (11) is connected to the first plate heat exchanger (7) through a pipeline; the refrigerant inlet of the evaporator (8) is connected to the refrigerant outlet of the expansion valve (11) through a pipeline provided with a valve; the refrigerant outlet of the first plate heat exchanger (7) is connected to the refrigerant inlet of the DC compressor (9) through a pipeline provided with a valve; the first plate heat exchanger (7) is connected to the buffer water tank (5) through a pipeline, and the refrigerant outlet of the first plate heat exchanger (7) is connected to the refrigerant inlet of the DC compressor (9) through a pipeline provided with a valve; The buffer water tank (5) is used to exchange heat with the refrigerant of the water-air dual-source heat pump unit. The low-temperature water in the buffer water tank (5) transfers heat to the refrigerant of the water-air dual-source heat pump unit and then returns to the buffer water tank (5). After the heat exchange, the refrigerant continues to pass through the DC compressor (9) or the evaporator (8) and the DC compressor (9) and then absorbs heat. Then, it exchanges heat with the low-temperature water from the buffer water tank (5) in the second plate heat exchanger (10), transfers the heat of the refrigerant to the low-temperature water in the buffer water tank (5), and the low-temperature water from the buffer water tank (5) absorbs heat and then returns to the buffer water tank (5). The refrigerant circulates in the pipeline of the water-air dual-source heat pump unit.

4. The inter-seasonal water body heat storage and heating system according to claim 3 is characterized in that: The evaporator (8), the DC compressor (9), the second plate heat exchanger (10), and the expansion valve (11) form an air source heat pump; the first plate heat exchanger (7), the DC compressor (9), the second plate heat exchanger (10), and the expansion valve (11) form a water source heat pump.

5. The inter-seasonal water body heat storage and heating system according to claim 3 is characterized in that: The solar controller (3) is electrically connected to the DC compressor (9) and is used to control the photovoltaic cell group (1) to generate electrical energy or control the liquid flow battery energy storage unit (4) to store electrical energy for driving the DC compressor (9), thereby controlling the working state of the water-air dual-source heat pump unit.

6. The inter-seasonal water body heat storage and heating system according to any one of claims 1 to 5, characterized in that: The liquid flow battery energy storage unit (4) comprises a positive electrode storage tank (14) for storing positive electrode electrolyte, a negative electrode storage tank (16) for storing negative electrode electrolyte, a battery stack (15) for generating electric current through redox reaction, and a third plate heat exchanger (17) and a fourth plate heat exchanger (18); the battery stack (15) is connected to the positive electrode storage tank (14), the negative electrode storage tank (16), the third plate heat exchanger (17) and the fourth plate heat exchanger (18) respectively through pipelines. ); the third plate heat exchanger (17) is connected to the positive electrode liquid storage tank (14) and the buffer water tank (5) through pipelines, respectively, and is used to achieve heat exchange between the positive electrode electrolyte and the water in the buffer water tank (5), thereby heating the water in the buffer water tank (5); the fourth plate heat exchanger (18) is connected to the negative electrode liquid storage tank (16) and the buffer water tank (5) through pipelines, respectively, and is used to achieve heat exchange between the negative electrode electrolyte and the water in the buffer water tank (5), thereby heating the water in the buffer water tank (5).

7. The inter-seasonal water body heat storage and heating system according to claim 3 is characterized by: The inter-seasonal hot water storage body (13) is provided with an electric heater (12) for heating the inter-seasonal hot water storage body (13).

8. The inter-seasonal water body heat storage and heating system according to claim 7 is characterized in that: The solar controller (3) is electrically connected to the electric heater (12) and is used to control the photovoltaic cell group (1) to generate electric energy or control the flow battery energy storage unit (4) to store electric energy for driving the electric heater (12), thereby controlling the working state of the electric heater (12).

9. A cross-seasonal water body heat storage and heating method based on photovoltaic direct drive, characterized by: include: Heat is collected by a solar thermal collection system (2) and a photovoltaic battery group (1), and the heat is stored in an inter-seasonal hot water storage body (13); water in a buffer water tank (5) is heated by one or more of the solar thermal collection system (2), a liquid flow battery energy storage unit (4), an inter-seasonal hot water storage body (13), a water-air dual-source heat pump unit, and an electric heater (12); when the water temperature in the buffer water tank (5) reaches a set temperature, heat is supplied to a heat user (6); the water-air dual-source heat pump unit comprises an air source heat pump and a water source heat pump.

10. The photovoltaic direct-drive cross-seasonal water body heat storage and heating method according to claim 9 is characterized in that: include: (1) Non-heating season The photovoltaic battery group (1) drives the first water pump (P-1) of the solar thermal collection system (2) to start the solar thermal collection system (2); the solar thermal collection system (2) and the liquid flow battery energy storage unit (4) are used to supply heat to the buffer water tank (5); when the high-temperature water in the buffer water tank (5) is overheated, the buffer water tank (5) is heat-exchanged with the inter-seasonal hot water storage body (13) through the second plate heat exchanger (10), and the heat is transferred to the inter-seasonal hot water storage body (13) for thermal energy storage; at the same time, the photovoltaic battery group (1) stores the excess electric energy generated in the liquid flow battery energy storage unit (4); (2) Heating season a. supplying heat to the buffer water tank (5) through the solar thermal collection system (2) and the liquid flow battery energy storage unit (4); if the water temperature in the buffer water tank (5) can meet the water temperature requirement for supplying heat to the heat user (6), the heat in the buffer water tank (5) is directly transferred to the heat user (6); b. If the water temperature in the buffer water tank (5) cannot meet the water temperature requirement for supplying heat to the heat user (6), the buffer water tank (5) is supplied with heat by the solar thermal collection system (2), the liquid flow battery energy storage unit (4), and the inter-seasonal hot water storage body (13) at the same time, and heat is supplied to the heat user (6) through the buffer water tank (5); c. If the temperature of the buffer water tank (5) after the solar thermal system (2), the flow battery energy storage unit (4), and the cross-seasonal hot water storage body (13) provide heat that cannot meet the water temperature requirement for providing heat to the heat user (6), the air source heat pump is turned on to provide auxiliary heating; d. If the solar thermal collection system (2), the flow battery energy storage unit (4), the cross-seasonal hot water storage body (13) and the air source heat pump auxiliary heating still cannot meet the water temperature requirement, the water source and air source dual source heat pump auxiliary heating is turned on; e. When the air source heat pump cannot extract heat from the low-temperature air, the air source heat pump is turned off, only the water source heat pump is in working mode, and the electric heater (12) is turned on for auxiliary heating.

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