Photovoltaic-thermal heating system with cross-seasonal phase change heat storage and control method thereof

Abstract

The application discloses a photovoltaic and photo-thermal heating system for cross-season phase change heat storage and a control method thereof, belongs to the technical field of cross-season heat supply, combines a solar photovoltaic and photo-thermal system, a Trombe wall system, a water source heat pump system and an energy storage heating system, and jointly forms a complete heating system, combines multiple heating modes, can guarantee the stability of heating under different climate conditions, makes the indoor temperature distribution more uniform, and can significantly improve the comfort of users. Meanwhile, the combination of multiple heating modes enables the heating system to more efficiently utilize energy, reduces the consumption and waste of energy.

Description

Technical Field

[0001] This invention belongs to the field of cross-seasonal heating technology, and particularly relates to a cross-seasonal phase change thermal storage photovoltaic thermal heating system and its control method. Background Technology

[0002] The statements in this section are merely background information relating to this disclosure and do not necessarily constitute prior art.

[0003] Solar energy is highly time-sensitive; during the day, there is ample sunlight, and the collectors operate at high capacity. At night, the collectors do not work, but we need heating both day and night. Therefore, to compensate for the lack of sunlight at night, supplementary heat sources are needed. For example, many systems use electric heating. This combination ensures heating reliability to some extent, but the cost is higher.

[0004] Due to its high efficiency, energy saving, environmental friendliness, and significant economic benefits, solar heating is receiving increasing attention. However, in northern regions, the utilization of solar energy is greatly affected by outdoor climate, resulting in poor stability and low utilization rates. Northern winters are cold, leading to high heating demand, but solar energy resources are relatively scarce in winter and abundant in summer. To adapt to seasonal changes, fully utilize solar energy resources, improve the indoor thermal environment and stability, and eliminate the instability of solar heat sources, it is necessary to further optimize the way buildings utilize solar energy.

[0005] However, most existing cross-seasonal heating systems use a single heating method, which easily leads to uneven heating water temperature and heat waste, resulting in poor user comfort. At the same time, existing heating systems also lack sophisticated intelligent control methods, resulting in excessive energy consumption in actual use. Summary of the Invention

[0006] To overcome the shortcomings of the prior art, this invention provides a photovoltaic thermal heating system with cross-seasonal phase change thermal storage and its control method, which combines multiple heating methods to solve the problem of cross-seasonal, all-weather heating.

[0007] To achieve the above objectives, one or more embodiments of the present invention provide the following technical solutions:

[0008] In a first aspect, the present invention discloses a photovoltaic thermal heating system with cross-seasonal phase change thermal storage, comprising a solar photovoltaic thermal system, a Transbronze wall system, a water source heat pump system and an energy storage heating system connected in sequence, wherein the solar photovoltaic thermal system is also directly connected to an underground heat storage box in the water source heat pump system.

[0009] During the heating season, the heat output end of the solar photovoltaic thermal system is sequentially connected to the Trombone wall system, the water source heat pump system, and the energy storage heating system, so that the heating water reaches the user end and completes the circulation; during the non-heating season, the heat output end of the solar photovoltaic thermal system is connected to the underground heat storage tank, and the underground heat storage tank exchanges heat to the heating water during the heating season, so that it reaches the user end.

[0010] Furthermore, the solar photovoltaic-thermal system is an integrated photovoltaic-thermal device, which includes a photovoltaic power generation module and a solar thermal module disposed on the back of the photovoltaic power generation module.

[0011] Furthermore, the Trumbe wall system includes a Trumbe wall on the shady side of the wall and a glass panel opposite it, with a water pipe network between the glass panel and the Trumbe wall, and a fan between the water pipe network and the glass panel.

[0012] Furthermore, the water pipe network is connected to the cooling pipes in the solar photovoltaic and solar thermal system.

[0013] Furthermore, the water source heat pump system includes an underground heat storage tank and a water loop heat pump and recovery device connected thereto.

[0014] Furthermore, the underground heat storage tank exchanges heat with the heating water in the pipeline between the Trumbo wall system and the energy storage heating system via a water loop heat pump.

[0015] Furthermore, the energy storage heating system includes a phase change hot water storage tank and a heating furnace connected thereto.

[0016] Furthermore, the phase change hot water storage tank is divided into three layers on each side: inner, middle, and outer, with the inner layer having a paraffin cavity.

[0017] Furthermore, the heating system also includes an energy storage power supply system, which is connected to the power output terminal of the solar photovoltaic and solar thermal system.

[0018] Secondly, the present invention discloses a photovoltaic solar thermal heating control method for cross-seasonal phase change thermal storage, comprising: using a solar photovoltaic solar thermal system as the main heat source, and a water source heat pump system and a heating furnace of an energy storage heating system as auxiliary heat sources;

[0019] During the heating season, when the outlet temperature of the solar photovoltaic thermal system is higher than or equal to the first preset temperature, the water source heat pump system does not operate, the heater does not operate, and the heating heat is directly supplied by the solar photovoltaic thermal system. When the outlet temperature of the solar photovoltaic thermal system is lower than the first preset temperature but higher than the third preset temperature, an auxiliary heat source is required, and the water source heat pump system operates. If the outlet temperature of the phase change hot water storage tank is higher than or equal to the second preset temperature, the heater does not start; if the outlet temperature of the phase change hot water storage tank is lower than the second preset temperature, the heater starts. When the outlet temperature of the solar photovoltaic thermal system is lower than the third preset temperature, the water source heat pump system operates. If the outlet temperature of the phase change hot water storage tank is higher than or equal to the second preset temperature, the heater does not start; if the outlet temperature of the phase change hot water storage tank is lower than the second preset temperature, the heater starts.

[0020] During the non-heating season, when the outlet temperature of the solar photovoltaic thermal system is higher than the fifth preset temperature, the waste heat generated by the solar photovoltaic thermal system enters the underground heat storage box to store the heat.

[0021] The above one or more technical solutions have the following beneficial effects:

[0022] The heating system of this invention combines a solar photovoltaic thermal system, a Transbryne wall system, a water source heat pump system, and an energy storage heating system to form a complete heating system. By incorporating multiple heating methods, it can ensure heating stability under different climatic conditions, resulting in a more uniform indoor temperature distribution and significantly improving user comfort. Furthermore, the combination of multiple heating methods allows the heating system to utilize energy more efficiently, reducing energy consumption and waste.

[0023] The heating system of the present invention can flexibly adjust the heating mode according to the actual situation, thereby reducing operating costs and being applicable to more different climate conditions and regions, with a wide range of applications.

[0024] This invention achieves intelligent control of the heating system by precisely monitoring and controlling the outlet temperature of the solar photovoltaic thermal system, the outlet temperature of the phase change hot water storage tank, and the room temperature. This ensures heating quality while avoiding energy waste and improving heating efficiency. Furthermore, the intelligent control system offers high timeliness and precision, enabling the heating system to respond quickly to user needs and enhancing user comfort.

[0025] The heating system of this invention utilizes a Transuber wall. The air circulation of the Transuber wall ensures a consistent temperature throughout the room, transferring solar thermal energy to the room and converting it into the heat needed for air conditioning. This reduces the load on traditional air conditioning systems and lowers indoor air conditioning energy consumption. Especially in winter, the use of solar thermal systems can significantly reduce air conditioning electricity consumption, making a substantial contribution to building energy conservation. Its features include simplicity, economy, practicality, ease of construction, and wide applicability.

[0026] The underground heat storage box of this invention can store heat across seasons to meet year-round heating needs. It utilizes excess heat in summer to reduce emissions of traditional energy sources, lower carbon emissions, and reduce costs. The underground heat storage box is circular in shape, which makes the stress more even. It is equipped with a recovery device to prevent water after heating from directly entering the interior of the underground heat storage box, thereby reducing the temperature inside the underground heat storage box and helping to improve the heating effect. The heating effect is excellent.

[0027] This invention employs phase change thermal storage, which can store excess heat from the daytime. Phase change thermal storage technology has advantages such as energy saving, environmental protection, and improved efficiency. It dissipates heat from multiple locations, resulting in more uniform temperature. The mobile heating allows for more specific heat application and targeted temperature increases, while also providing clean domestic hot water. Attached Figure Description

[0028] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0029] Figure 1 This is a schematic diagram of the overall structure of the heating system in this embodiment;

[0030] Figure 2 This is a cross-sectional view of the photovoltaic-thermal integrated device in this embodiment;

[0031] Figure 3 This is a structural diagram of the cooling pipes of the photovoltaic-thermal integrated device in this embodiment;

[0032] Figure 4 This is a cross-sectional view of the water pipe network of the Transbry wall in this embodiment;

[0033] Figure 5 This is a front view of the water pipe network of the Transbry wall in this embodiment;

[0034] Figure 6 This is a schematic diagram of the phase change hot water storage tank in this embodiment.

[0035] Among them, 1-photovoltaic-thermal integrated device, 2-glass wall, 3-water pump, 4-phase change hot water storage tank, 5-heating furnace, 6-underfloor heating, 7-movable radiator, 8-water storage tank, 9-water pipe network, 10-Trumbo wall, 11-battery, 12-underground heat storage tank, 13-pressure reduction device, 14-condenser, 15-compressor, 16-evaporator, 17-expansion valve, 18-first temperature sensor, 19-second temperature sensor; 20-third temperature sensor; 21-second... Four temperature sensors, 22-first valve, 23-second valve, 24-recovery device, 25-pressure sensor, 26-water level sensor, 27-fan, 28-Trumbo upwind outlet baffle, 29-Trumbo downwind outlet baffle, 30-Tesla valve, 31-phase change material cavity, 32-glass cover, 33-air interlayer, 34-photovoltaic template, 35-heat absorber, 36-cooling pipe, 37-insulation layer, 38-relay, 39-inverter, 40-grid. Detailed Implementation

[0036] It should be noted that the following detailed descriptions are exemplary and intended to provide further illustration of the invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0037] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0038] Where there is no conflict, the embodiments and features in the embodiments of the present invention can be combined with each other.

[0039] Example 1

[0040] See appendix Figure 1 As shown, this embodiment discloses a photovoltaic thermal heating system with cross-seasonal phase change thermal storage, including a solar photovoltaic thermal system, a Trumbo wall system, a water source heat pump system and an energy storage heating system connected in sequence. The solar photovoltaic thermal system is also directly connected to an underground heat storage tank, and the underground heat storage tank is connected to the water source heat pump system.

[0041] During the heating season, the heat output end of the solar photovoltaic thermal system is sequentially connected to the Trombone wall system, the water source heat pump system, and the energy storage heating system to reach the user end; during the non-heating season, the heat output end of the solar photovoltaic thermal system is connected to the underground heat storage tank, which exchanges heat with the heating water during the heating season to reach the user end.

[0042] In this embodiment, the solar photovoltaic-thermal system is an integrated photovoltaic-thermal device, which includes a photovoltaic power generation module and a solar thermal module disposed on the back of the photovoltaic power generation module. The photovoltaic power generation module is connected to the energy storage power supply system.

[0043] like Figure 2 As shown, the photovoltaic power generation module includes a photovoltaic module 34 and a glass cover plate 32 disposed above it; the solar thermal module includes a heat absorption plate 35, a cooling pipe 36 is disposed below the heat absorption plate 35, and an insulation layer 37 is disposed below the cooling pipe 36; the photovoltaic module 34 is in close contact with the heat absorption plate 35 below, which can convert the energy of sunlight into electrical energy and heat energy, realize the dual utilization of energy, and improve energy utilization efficiency.

[0044] In some embodiments, an air gap 33 is provided between the photovoltaic module 34 and the glass cover plate 32. The air gap can effectively insulate against the high-temperature outdoor environment, reduce heat transfer to the photovoltaic module, and thus lower the operating temperature of the photovoltaic module. This helps to improve the power generation efficiency of the photovoltaic module, because a high-temperature environment will reduce the conversion efficiency of the photovoltaic cell; in a low-temperature environment, the air gap can also prevent condensation between the photovoltaic module and the glass cover plate, keeping the device dry and clean.

[0045] In operation, the photovoltaic module 34 in the photovoltaic-thermal integrated device absorbs sunlight and converts it into electrical energy. Simultaneously, due to the low photovoltaic conversion efficiency, the photovoltaic module 34 itself is also heated, which in turn heats the heating water in the cooling pipe 36 below the absorber plate 35 via radiation. Solar energy also passes through the glass gaps between the photovoltaic modules and is directly absorbed by the absorber plate 35, further heating the heating water in the cooling pipe 36 below the absorber plate 35. After absorbing heat and cooling, the flowing heating water continuously carries away the heat generated by the photovoltaic module 34 and the absorber plate 35, and the heated water flows into the water network of the Trumbo wall system.

[0046] like Figure 3As shown, the cooling pipe 36 is equipped with multiple circulation loops and uses circular fins to expand the heat exchange area. By setting multiple circulation loops, effective circulation of heating water within the pipe can be ensured, thereby increasing the cooling area and improving cooling efficiency. This helps to quickly transfer the heat generated in the photovoltaic module 34 and the absorber plate 35 to the heating water; and by increasing the heat exchange area on the pipe surface through the circular fins, heat exchange efficiency is improved. By increasing the contact area between the cooling pipe and the heating water, the heat transfer process can be accelerated.

[0047] In this embodiment, the Trumbo wall system includes a Trumbo wall 10 on the shady side of the wall and a glass plate opposite it. A water pipe network 9 channel is provided between the glass plate and the Trumbo wall 10. A fan 27 is also provided between the water pipe network 9 channel and the glass plate. The water pipe network 9 channel is set close to the Trumbo wall 10 and is connected to the cooling pipe 36 in the solar photovoltaic thermal system.

[0048] A Trumpet upwind outlet baffle 28 is installed at a certain distance above the Trumpet wall 10, and a Trumpet downwind outlet baffle 29 is installed at a certain distance below it. The gaps between the Trumpet wall 10 and the upper and lower Trumpet upwind outlet baffles 28 and downwind outlet baffles 29 form an air layer. The water pipe network 9 provides ample space for the airflow. Driven by the fan 27, the air layer forms an air circulation, allowing for sufficient heat exchange between the upper and lower air layers and the room. The Trumpet wall absorbs solar radiation and converts it into heat energy. The thermal mass of the wall stores this heat and slowly releases it into the interior space over time. The Trumpet wall system provides heating for the building through the collection and storage of solar energy.

[0049] like Figure 4 As shown, the water pipe network 9 has an S-shaped flow channel, which increases the contact time and area with the Transporal wall 10, allowing the heating water in the flow channel to absorb the heat stored in the Transporal wall, further increasing the heating water temperature. Figure 5 As shown, the cross-section of the water pipe network 9 flow channel is circular, and straight fins are provided on its outer periphery to further increase the heat exchange area of ​​the flow channel; the fan can be switched on or off, making the system more flexible and stable.

[0050] In this embodiment, as Figure 1 As shown, the water source heat pump system includes an underground heat storage tank 12, a water loop heat pump, and a recovery device 24. The underground heat storage tank 12 is connected to the water loop heat pump and then connected to the recovery device 24. The water loop heat pump includes an expansion valve 17 and a compressor 15 that form a water circulation loop. One side of the water circulation loop is connected to the condenser 14, and the other side is connected to the evaporator 16. It is used to release the heat from the underground heat storage tank 12 into the heating water to heat the heating water and achieve heating.

[0051] In the water-loop heat pump, the refrigerant is in a liquid state in the evaporator 16 section. Because the evaporator 16 is in contact with water in the underground heat storage tank 12, the refrigerant absorbs heat and begins to evaporate into a gaseous state. During this process, heat is absorbed from the water, causing the water temperature to drop. At this point, the water in the underground heat storage tank 12 enters the recovery device 24. Then comes the compression process: the refrigerant vapor is subsequently drawn into and compressed by the compressor 15. During compression, the refrigerant temperature and pressure increase. This process increases the refrigerant's heat energy content. Next, the high-temperature, high-pressure refrigerant vapor enters the condenser 14, where it releases the absorbed heat to the heating water. As heat is released, the refrigerant vapor gradually cools and condenses into a liquid state. Finally, the liquid refrigerant passes through the expansion valve, where its pressure and temperature drop sharply. The expanded refrigerant re-enters the evaporator to begin a new round of evaporation, absorbing even more heat.

[0052] The heat input end of the underground heat storage box 12 is connected to the solar photovoltaic thermal system via a solenoid valve, and the heat output end is connected to the evaporator 16. The heat is released into the heating water flowing out from the water pipe network 9 through a water ring heat pump. The heating water, after being heated by the water source heat pump system, continues to flow into the phase change heat storage tank. The underground heat storage box 12 is also equipped with a pressure sensor 25 and a pressure regulating device 13. The waste heat generated by the solar photovoltaic thermal system enters the underground heat storage box 12 for heat storage. The pressure sensor 25 works in conjunction with the controller to automatically control the pressure inside the underground heat storage box 12, so that the inside of the underground heat storage box 12 is always in a stable state.

[0053] A water pump 3 is installed on the pipe connecting the Trumbo wall system and the water source heat pump system to drive the circulation of heating water and provide circulation power.

[0054] In this embodiment, as Figure 1 As shown, the energy storage heating system includes a phase change hot water storage tank 4 and a heating furnace 5 connected thereto.

[0055] like Figure 6 As shown, the phase change hot water storage tank 4 is divided into three layers on each side, all square in shape, which can be fitted against the wall. The inner layer also has a cavity for the phase change material, paraffin wax. Heated heating water can enter the tank from the lower side of the inner layer, exit from the top, flow into the middle layer tank, then exit from the bottom and enter the outer layer tank. Hot water flows out of the phase change hot water storage tank from the top of the outer layer tank. Conversely, heated heating water can also enter the tank from the lower side of the outer layer, with hot water flowing out from the top of the outer layer tank.

[0056] Insulation layers are installed between the inner and outer layers, and Tesla valves 30 are installed between the channels of each layer. Water flow is unidirectional, collectively improving the heat storage and release efficiency of the water tank. The insulation layers primarily reduce heat transfer loss between the inner and outer layers, and the Tesla valves control the direction of water flow, ensuring unidirectional flow. This guarantees that water flows along a predetermined path during heating and storage, avoiding ineffective heat transfer and loss, and achieving more efficient, stable, and environmentally friendly heat energy utilization.

[0057] In this embodiment, as Figure 1 As shown, the heating methods at the user end of the heating system include underfloor heating 6, movable radiators 7 connected to the heating furnace 5, Trumbo wall 10, and air circulation.

[0058] In this embodiment, as Figure 1 As shown, the photovoltaic thermal heating system with cross-seasonal phase change thermal storage also includes an energy storage power supply system, which is connected to the power output terminal of the solar photovoltaic thermal system.

[0059] The energy storage power supply system includes a battery 11 and a power grid 40. The power output of the solar photovoltaic and solar thermal system is connected to the battery 11, the power grid 40, and the heating furnace 5, respectively. The heating furnace 5 is connected to both the battery 11 and the power grid 40. The direct current from the solar photovoltaic and solar thermal system can be directly used to heat the heating furnace 5, achieving higher thermal efficiency and reducing inverter losses, or it can be stored in the battery 11.

[0060] Fan 27, water pump 3, and water source heat pump are all connected to the power grid 40 and powered by the grid. Considering the instability and intermittency of the electricity generated by the solar photovoltaic thermal system, which cannot meet the continuous power demand of the heating system, and that components such as the fan, water pump, and water source heat pump are key parts of the heating system, relying solely on solar power may lead to interruptions or performance degradation of the heating system due to insufficient or unstable power. Therefore, this embodiment uses grid power to provide a stable and continuous power supply, ensuring the normal operation of the heating system.

[0061] The direct current from the solar photovoltaic thermal system 1 is directly used to heat the furnace 5, achieving higher thermal efficiency and reducing inverter losses, or it is stored in the battery 11. If the direct current generated by the photovoltaic thermal system 1 and the electrical energy stored in the battery 11 are insufficient to support the needs of the furnace 5, the furnace 5 will consume the power of the grid. The power consumed by the water source heat pump and the fan 27 comes from the grid.

[0062] like Figure 1As shown, the heating system also includes a relay 38, which is connected to the power grid 40, battery 11, and heater 5. The connection between the power grid 40 and the load heater 5 is wirelessly controlled. The aforementioned energy storage power supply system is controlled by the relays, which control the selection of different power supply paths within the system.

[0063] In this embodiment, the heating system is equipped with a first temperature sensor 18 for monitoring the outlet temperature of the phase change hot water storage tank 4, a second temperature sensor 19 for monitoring the temperature of the heating water output by the heating furnace 5, a third temperature sensor 20 for monitoring the outlet temperature of the photovoltaic-thermal integrated device, and a fourth temperature sensor 21 for monitoring the room temperature. The heating system is intelligently controlled through the monitoring of the above temperature sensors.

[0064] In this embodiment, the heating system is also equipped with a water storage tank 8 and a first valve 22 and a second valve 23 on the system pipeline to realize the circulation of heating water in the heating system. Specifically, the heating water circulation is as follows: the outlet pipeline of the photovoltaic-thermal integrated device is divided into two paths through the second valve 23. One path goes directly to the underground heat storage tank 12, and the other path passes through the water pipe network 9, the first valve 22, the water source heat pump, the phase change hot water storage tank 4, the heating furnace 5, and the heating device (movable heat sink 7) in sequence. The heating furnace 5 and the heating device are placed side by side. The water passes through the inlet C of the water storage tank 8 and reaches the water storage tank 8. The water in the water storage tank 8 can be replenished by the water pipe and the inlet C. The water in the water storage tank 8 can be divided into two paths. One path enters the photovoltaic-thermal integrated device through the outlet A to complete one cycle. The other path passes through the outlet B, the first valve 22, the water pump 3, the condenser 14, the phase change hot water storage tank 4, the heating furnace 5, and the heating device (movable heat sink 7), passes through the inlet C, and returns to the water storage tank 8 to complete one cycle.

[0065] Example 2

[0066] This embodiment discloses a photovoltaic thermal heating control method for cross-seasonal phase change thermal storage, including: using a solar photovoltaic thermal system as the main heat source, and a water source heat pump system and a furnace 5 of an energy storage heating system as auxiliary heat sources to meet the user's heating needs.

[0067] The heating system includes three operating modes, specifically:

[0068] Operating mode 1: Applicable to the non-heating season, the photovoltaic-thermal integrated device 1 leads directly to the underground heat storage box 12.

[0069] Operating mode 2: Applicable when there is a heating season and the outlet temperature of the photovoltaic-thermal integrated device 1 is higher than the third preset temperature T3. The photovoltaic-thermal integrated device 1 passes through the water pipe network 9, the first valve 22, the water source heat pump, the condenser 14, the phase change hot water storage tank 4, the heating furnace 5 and the heating device (movable heat sink 7) in sequence. The heating furnace 5 and the heating device are placed side by side. After passing through the inlet C, the water reaches the storage tank 8 and returns to the photovoltaic-thermal integrated device 1 to complete one cycle.

[0070] Operating mode 3: Applicable when there is a heating season and the outlet temperature of the photovoltaic-thermal integrated device 1 is lower than the third preset temperature T3. The water flows from the storage tank 8 through the outlet B, the first valve 22, the water pump 3, the condenser 14, the phase change hot water storage tank 4, the heating furnace 5 and the heating device, through the inlet C, and back to the storage tank 8 to complete one cycle.

[0071] The heating system's operation control is based on three main parameters: the first parameter is the outlet temperature of the photovoltaic-thermal integrated device (which can be indicated by the third temperature sensor 20), the second parameter is the room temperature (which can be indicated by the fourth temperature sensor 21), and the third parameter is the outlet temperature of the phase change hot water storage tank 4 (which can be indicated by the first temperature sensor 18).

[0072] During the heating season, the control methods are as follows:

[0073] The fourth temperature sensor 21 displays that the room temperature is lower than the preset room temperature Tx (temperature difference greater than 3 degrees Celsius). The first preset temperature T1 and the second preset temperature T2 are increased to T1x and T2x, respectively. Since the temperature difference between the indoor temperature and the preset temperature is too large, to quickly bring the room temperature to a comfortable level, the preset temperature thresholds T1 and T2 for the photovoltaic-thermal integrated device outlet temperature and the phase change hot water storage tank outlet temperature are increased. The specific control is as follows:

[0074] If the outlet temperature of the photovoltaic-thermal integrated device is higher than T1x, i.e. when there is sufficient sunlight, the water source heat pump does not work. Then, hot water enters from the outside of the phase change hot water storage tank 4 during the heating season without heat storage. If the outlet temperature of the phase change hot water storage tank 4 displayed by the first temperature sensor 18 is lower than T2x, the heating furnace 5 is started for heating. If the outlet temperature of the phase change hot water storage tank 4 displayed by the first temperature sensor 18 is not lower than T2x, the heating furnace 5 is not started. The water pump 3 provides circulation power for the heating circulating water. At this time, the fan 27, the Trumbo wall baffle and the Trumbo lower baffle are turned on to enhance the heat exchange between the upper and lower floors of the room.

[0075] When the outlet temperature of the integrated photovoltaic-thermal device is lower than T1x but higher than the third preset temperature T3, that is, there is sunlight but it is insufficient, the water source heat pump operates to raise the temperature to the fourth preset temperature T4 (T4<T2) (the temperature sensor built in the water source heat pump can control the outlet water temperature), then the hot water enters from the outside of the phase change heat storage water tank 4 in the heating season without storing heat. If the outlet temperature of the phase change heat storage water tank 4 is lower than T2x, the heating furnace 5 is started for heating; if the outlet temperature of the phase change heat storage water tank is not lower than T2x, the heating furnace 5 is not started. The water pump 3 provides circulating power for the heating circulating water. At this time, the fan 27, the upper baffle of the Trombe wall and the lower baffle of the Trombe wall are opened to strengthen the heat exchange between the upper and lower layers of the room and assist the room to heat up.

[0076] When the fourth temperature sensor 21 detects that the room temperature is close to the preset room temperature Tx (the temperature difference is within 3 degrees Celsius), and the temperature difference between the indoor temperature and the preset temperature is small, the specific control is as follows:

[0077] When the outlet temperature of the integrated photovoltaic-thermal device is higher than or equal to the first preset temperature T1, that is, the sunlight is sufficient, the water source heat pump does not operate. Hot water enters from the lower side of the inner layer of the water tank, exits from the upper side, flows into the middle-layer water tank, then exits from the lower side and enters the outer-layer water tank, and flows out of the phase change heat storage water tank 4 from the upper side of the outer-layer water tank. Excess heat will be stored in the paraffin in the phase change material cavity 31, the heating furnace 5 does not operate, the heating heat is directly supplied by the integrated photovoltaic-thermal device, and the water pump 3 provides circulating power for the heating circulating water. At this time, the fan 27, the upper baffle of the Trombe wall and the lower baffle of the Trombe wall are opened to strengthen the heat exchange between the upper and lower layers of the room.

[0078] When the outlet temperature of the integrated photovoltaic-thermal device is lower than the first preset temperature T1 but higher than the third preset temperature T3, that is, there is sunlight but it is insufficient, the water source heat pump operates to raise the temperature to T4 (T4<T2). Hot water enters the phase change heat storage water tank 4 from the lower side of the outer layer, and flows out of the phase change heat storage water tank 4 from the upper side of the outer-layer water tank. The heating furnace 5 operates, the water pump 3 provides circulating power for the heating circulating water. At this time, the fan 27, the upper baffle of the Trombe wall and the lower baffle of the Trombe wall are opened to strengthen the heat exchange between the upper and lower layers of the room.

[0079] When the fourth temperature sensor 21 detects that the room temperature is higher than the preset room temperature Tx (the temperature difference is more than 3 degrees Celsius), and the excessively high indoor temperature affects user comfort, the specific control is as follows:

[0080] When the outlet temperature of the integrated photovoltaic-thermal device is higher than or equal to the first preset temperature T1, that is, when the sunlight is sufficient, the flow rate of the water pump 3 is reduced, so that the heating water can sufficiently exchange heat with the phase change material, and the water source heat pump does not operate. Hot water enters the water tank from the lower side of the inner layer, exits from the upper side, flows into the middle-layer water tank, then exits from the lower side and enters the outer-layer water tank. Hot water flows out of the phase change heat storage water tank 4 from the upper side of the outer-layer water tank, and the excess heat will be stored in the paraffin in the phase change material cavity 31. The heating furnace 5 does not operate, and the heating heat is directly supplied by the integrated photovoltaic-thermal device. The water pump 3 provides circulating power for the heating circulating water. At this time, the fan 27, the upper baffle of the Trombe wall and the lower baffle of the Trombe wall are opened to strengthen heat exchange between the upper and lower layers of the room.

[0081] When the outlet temperature of the integrated photovoltaic-thermal device is lower than the first preset temperature T1 but higher than the third preset temperature T3, that is, there is sunlight but it is insufficient, the water source heat pump operates to raise the temperature to the fourth preset temperature T4 (T4<T2). Hot water enters the water tank from the lower side of the outer layer, and flows out of the phase change heat storage water tank 4 from the upper side of the outer-layer water tank. The heating furnace 5 does not operate, and the water pump 3 provides circulating power for the heating circulating water. At this time, the fan 27, the upper baffle of the Trombe wall and the lower baffle of the Trombe wall are opened to strengthen heat exchange between the upper and lower layers of the room.

[0082] When the outlet temperature of the integrated photovoltaic-thermal device is lower than the third preset temperature T3, that is, there is no sunlight, the third operation mode is applied. At this time, the water source heat pump operates to raise the temperature to the fourth preset temperature T4 (T4<T2). Hot water enters the water tank from the lower side of the inner layer, exits from the upper side, flows into the middle-layer water tank, then exits from the lower side and enters the outer-layer water tank. Hot water flows out of the phase change heat storage water tank 4 from the upper side of the outer-layer water tank, and the heat stored in the paraffin will be utilized. If the temperature displayed by the first temperature sensor 18 is higher than or equal to the second preset temperature T2, the heating furnace 5 is not started; if the temperature displayed by the first temperature sensor 18 is lower than the second preset temperature T2, the heating furnace 5 is started. The water pump 3 provides circulating power for the heating circulating water, and at this time the fan 27, the upper baffle of the Trombe wall and the lower baffle of the Trombe wall are closed.

[0083] In the heating season, when the water source heat pump system is operating, the water stored in the underground heat storage tank 12 will be pumped to the water source heat pump system for heat exchange, and the waste water will enter the recovery device 24.

[0084] In the heating season, when there is sunlight, the Trombe wall upper air outlet baffle 28 and the Trombe wall lower air outlet baffle 29 are opened. The heat generated by the Trombe wall solar energy is absorbed by two media: the first is air, which forms an air circulation under the action of the fan 27, so that heat enters the room and promotes air exchange between the bottom layer and the upper layer; the second is heating water, so that heat enters the heating water. When there is no sunlight, the Trombe wall upper air outlet baffle 28 and the Trombe wall lower air outlet baffle 29 are closed, and the fan 27 stops operating at the same time.

[0085] During the heating season, the DC power from the solar photovoltaic thermal system 1 is used for direct heating when the heating furnace 5 is working, reducing inverter losses. When the heating furnace 5 is not working, the DC power is stored in the battery 11. The power consumed by the water source heat pump and the fan 27 comes from the power grid.

[0086] During the non-heating season, the control methods are as follows:

[0087] When the outlet temperature of the photovoltaic-thermal integrated device is greater than the fifth preset temperature T5, the waste heat generated by the solar photovoltaic-thermal system enters the underground heat storage box 12 through the third temperature sensor 20 and the second valve 23. The air inside the underground heat storage box 12 will be discharged along the pressure regulating device 13, thereby automatically controlling the pressure inside the underground heat storage box 12 and keeping the inside of the underground heat storage box in a stable state.

[0088] During the non-heating season, the DC power from the solar photovoltaic and solar thermal system is fed into the grid via an inverter, and can also be stored in battery 11.

[0089] In a photovoltaic thermal heating system with cross-seasonal phase change thermal energy storage, the selection of different power supply paths in the energy storage power supply system is controlled by a relay, specifically including:

[0090] When the photovoltaic-thermal integrated device 1 can generate enough electricity to meet the load, the DC power generated by the photovoltaic-thermal integrated device 1 is directly used for the operation of the heating furnace 5 through relay control when the heating furnace 5 is not in operation. When the heating furnace 5 is not in operation, the DC power from the photovoltaic-thermal integrated device 1 will be stored in the battery 11. If the energy stored in the battery 11 has reached its limit, the DC power from the photovoltaic-thermal integrated device 1 will be transported back to the grid through relay control and inverter, prioritizing the operation of the heating furnace 5, followed by the storage in the battery 11, and finally the excess power will be transmitted back to the grid through the inverter.

[0091] When the photovoltaic-thermal integrated device 1 cannot generate enough power to meet the load, when the heating furnace 5 is working, the DC power generated by the photovoltaic-thermal integrated device 1 is transmitted to the battery 11 for storage through relay control. If the battery 11 power level is not lower than the warning line, the heating furnace 5 is powered by the battery. If the battery 11 power level is lower than the warning line, the heating furnace 5 is powered by the grid. When the heating furnace 5 is not working, the DC power generated by the photovoltaic-thermal integrated device 1 is directly transmitted to the battery 11 for storage. If the energy stored in the battery 11 has reached its upper limit, the DC power from the photovoltaic-thermal integrated device will be transmitted back to the grid through relay control and inverter.

[0092] When the photovoltaic-thermal integrated device 1 is not generating electricity, when the heating furnace 5 is working, it first uses the electricity stored in the battery 11 to supply its needs, and secondly uses the grid current supply.

[0093] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

[0094] While the specific embodiments of the present invention have been described above in conjunction with the accompanying drawings, this is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art without creative effort based on the technical solutions of the present invention are still within the scope of protection of the present invention.

Claims

1. A photovoltaic thermal heating system with cross-seasonal phase change thermal storage, characterized in that, It includes a solar photovoltaic thermal system, a Trumbo wall system, a water source heat pump system and an energy storage heating system connected in sequence. The solar photovoltaic thermal system is also directly connected to the underground heat storage box in the water source heat pump system. During the heating season, the heat output end of the solar photovoltaic thermal system is sequentially connected to the Trumbo wall system, the water source heat pump system, and the energy storage heating system, so that the heating water reaches the user end and completes the circulation; during the non-heating season, the heat output end of the solar photovoltaic thermal system is connected to the underground heat storage tank, and the underground heat storage tank exchanges heat to the heating water during the heating season, so that it reaches the user end. The Trumbo wall system includes a Trumbo wall on the shaded side of the wall and a glass panel opposite it. A water pipe network is provided between the glass panel and the Trumbo wall, and a fan is also provided between the water pipe network and the glass panel. The water pipe network is connected to the cooling pipes in the solar photovoltaic thermal system. The energy storage heating system includes a phase change hot water storage tank and a heating furnace connected thereto.

2. The photovoltaic thermal heating system with cross-seasonal phase change thermal storage as described in claim 1, characterized in that, The solar photovoltaic-thermal system is an integrated photovoltaic-thermal device, which includes a photovoltaic power generation module and a solar thermal module installed on the back of the photovoltaic power generation module.

3. The photovoltaic thermal heating system with cross-seasonal phase change thermal storage as described in claim 1, characterized in that, The water source heat pump system includes an underground heat storage tank and a water loop heat pump and recovery device connected thereto.

4. A photovoltaic thermal heating system with cross-seasonal phase change thermal storage as described in claim 3, characterized in that, The underground heat storage tank uses a water-loop heat pump to exchange heat with the heating water in the pipeline between the Trumbo wall system and the energy storage heating system.

5. A photovoltaic thermal heating system with cross-seasonal phase change thermal storage as described in claim 1, characterized in that, The phase change hot water storage tank is divided into three layers on each side: inner, middle, and outer. The inner layer has a cavity filled with paraffin wax.

6. A photovoltaic thermal heating system with cross-seasonal phase change thermal storage as described in claim 1, characterized in that, The heating system also includes an energy storage power supply system, which is connected to the power output terminal of the solar photovoltaic and solar thermal system.

7. A method for controlling photovoltaic thermal heating with cross-seasonal phase change thermal storage, employing a photovoltaic thermal heating system with cross-seasonal phase change thermal storage as described in any one of claims 1-6, characterized in that, include: The solar photovoltaic thermal system is the main heat source, while the water source heat pump system and the heating furnace of the energy storage heating system are auxiliary heat sources. During the heating season, when the outlet temperature of the solar photovoltaic thermal system is higher than or equal to the first preset temperature, the water source heat pump system does not operate, the heater does not operate, and the heating heat is directly supplied by the solar photovoltaic thermal system. When the outlet temperature of the solar photovoltaic thermal system is lower than the first preset temperature but higher than the third preset temperature, an auxiliary heat source is required, and the water source heat pump system operates. If the outlet temperature of the phase change hot water storage tank is higher than or equal to the second preset temperature, the heater does not start; if the outlet temperature of the phase change hot water storage tank is lower than the second preset temperature, the heater starts. When the outlet temperature of the solar photovoltaic thermal system is lower than the third preset temperature, the water source heat pump system operates. If the outlet temperature of the phase change hot water storage tank is higher than or equal to the second preset temperature, the heater does not start; if the outlet temperature of the phase change hot water storage tank is lower than the second preset temperature, the heater starts. During the non-heating season, when the outlet temperature of the solar photovoltaic thermal system is higher than the fifth preset temperature, the waste heat generated by the solar photovoltaic thermal system enters the underground heat storage box to store the heat.

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