Photovoltaic heat exchange integrated heating system and control method thereof

Abstract

The application discloses a photovoltaic heat exchange integrated heating system and a control method thereof. The photovoltaic heat exchange integrated heating system comprises a heating pipe network module, a heat exchange station load module, a photovoltaic light heat device and a power management module. The heat exchange station load module is used for controlling the operation of the heating pipe network module, and comprises a circulating pump used for controlling the flow rate of a heating medium in the heating pipe network module. The photovoltaic light heat device comprises a photovoltaic module used for converting light energy into electric energy. The power management module comprises an energy storage unit and a control unit, the photovoltaic module is connected with the energy storage unit, the control unit is used for controlling the photovoltaic module to provide electric energy for the operation of the heat exchange station load module in a photovoltaic power surplus state, controlling the energy storage unit to store the electric energy converted by the photovoltaic light heat device in the case that there is excess electric energy in the operation of the heat exchange station load module, and controlling the circulating pump of the heat exchange station load module to operate at an energy storage frequency.

Description

Technical Field

[0001] This application relates to the field of heat exchange heating system technology, and in particular to a photovoltaic heat exchange integrated heating system and its control method. Background Technology

[0002] Heat exchange stations are the core hubs of centralized heating systems, responsible for the exchange and distribution of heat between heat sources and users. Their operation directly impacts users' heating needs, playing a crucial role, especially in frigid regions. The long-term operation of heat exchange stations demands significant power supply and requires high reliability. Therefore, optimizing the power supply and heating methods for heat exchange stations has become a pressing technical challenge in the heating industry. Summary of the Invention

[0003] This application aims to address at least one of the technical problems existing in the prior art or related technologies.

[0004] The first aspect of this application proposes a photovoltaic heat exchange integrated heating system, which includes: a heating pipeline module, a heat exchange station load module, a photovoltaic thermal device, and a power management module. The heat exchange station load module controls the operation of the heating pipeline module and includes a circulation pump to control the flow rate of the heating medium within the heating pipeline module. The photovoltaic thermal device includes a photovoltaic module that converts solar energy into electrical energy. The power management module includes an energy storage unit and a control unit, connected to the photovoltaic module. The control unit controls the photovoltaic module to provide power to the heat exchange station load module when there is a photovoltaic power surplus. When the heat exchange station load module has surplus power, the control unit controls the energy storage unit to store the electrical energy converted by the photovoltaic thermal device. When the energy storage unit is fully charged and has surplus power, the control unit controls the circulation pump of the heat exchange station load module to operate at the energy storage frequency. The control unit also controls the energy storage unit to discharge to the heat exchange station load module and controls the circulation pump to operate at a rated frequency, wherein the energy storage frequency is lower than the rated frequency, when there is a photovoltaic power shortage.

[0005] In some technical solutions provided in this application, the power management module further includes: a grid-connected inverter, which provides power to the heat exchange station load module. The DC side of the grid-connected inverter is connected to the energy storage unit, and the AC side of the grid-connected inverter is connected to both the heat exchange station load module and the mains power grid. The control unit is also used to control the grid-connected inverter to provide mains power to the heat exchange station load module when the energy storage unit's power level is lower than a preset level.

[0006] In some of the technical solutions provided in this application, the control unit is also used to control the grid-connected inverter to transmit electrical energy to the grid when there is a surplus of photovoltaic power.

[0007] In some technical solutions provided in this application, the heating network module includes: a primary network return water pipe and a primary network supply water pipe. The primary network return water pipe is equipped with a water temperature detection device, and the primary network supply water pipe is equipped with a flow regulating valve. The control unit is also used to adjust the speed of the circulating pump and / or the opening degree of the flow regulating valve according to the return water temperature collected by the water temperature detection device.

[0008] In some of the technical solutions provided in this application, the heating network module further includes: a secondary network water supply pipe and a secondary network return pipe. The photovoltaic thermal device further includes: a solar thermal module, which is used to heat the heating medium; the outlet pipe of the solar thermal module is connected to the secondary network water supply pipe, and the inlet pipe of the solar thermal module is connected to the secondary network return pipe.

[0009] In some of the technical solutions provided in this application, the heating network module also includes a room temperature detection device installed in the heating building, and the outlet water pipe of the solar thermal module is equipped with a bypass regulating valve. The control unit is also used to adjust the opening degree of the bypass regulating valve according to the indoor temperature collected by the room temperature detection device.

[0010] In some of the technical solutions provided in this application, the heat exchange station load module also includes: a water supply pump, which is used to supplement the heating medium to the heating network module, and the capacity configuration of the energy storage unit is sufficient to allow the circulating pump and the water supply pump to operate continuously for 2 to 4 hours.

[0011] The second aspect of this application proposes a control method for an integrated photovoltaic heat exchange heating system. This control method is applicable to any of the aforementioned integrated photovoltaic heat exchange heating systems and includes: Determine the operating status of the photovoltaic device; When the photovoltaic power is in surplus state, the photovoltaic modules are controlled to provide power to the load modules of the heat exchange station. When the load module of the heat exchange station has surplus power, the energy storage unit is controlled to store the electrical energy converted by the photovoltaic thermal device; When the energy storage unit is fully charged and has surplus power, the circulating pump of the heat exchange station load module is controlled to operate at the energy storage frequency. When the photovoltaic power shortage is in operation, the energy storage unit is controlled to discharge to the load module of the heat exchange station, and the circulating pump is controlled to operate at the rated frequency. Among them, the energy storage frequency is lower than the rated frequency.

[0012] In some technical solutions provided in this application, when the operating state is a photovoltaic power shortage state, the steps of controlling the energy storage unit to discharge to the load module of the heat exchange station and controlling the circulating pump to operate at the rated frequency specifically include: When the energy storage unit's charge is lower than the preset charge, the grid-connected inverter is controlled to supply mains power to the heat exchange station load module.

[0013] In some technical solutions provided in this application, the steps of controlling the circulating pump of the heat exchange station load module to operate at the energy storage frequency when the energy storage unit is fully charged and has surplus power specifically include: Control the grid-connected inverter to deliver electrical energy to the mains power grid.

[0014] Compared with related technologies, the present invention has at least the following beneficial effects: This invention introduces renewable energy to achieve a deep coupling of "heat-assisted electricity and electricity-driven heat." It utilizes photovoltaic power to drive a power management module, organically integrating them to form a self-sufficient power supply device. Photovoltaic power is consumed locally and combined with grid power, reducing electricity costs for heat exchange stations and improving power supply reliability. Furthermore, it uses the thermal inertia of the heating network and the building itself as virtual energy storage, overcoming the capacity limitations of electrical energy storage. The electrical energy storage unit provides short-term electrical backup, while the thermal energy storage of the heating network provides long-term thermal backup. This combines the consumption of photovoltaic power with flexible adjustment of heating load, achieving "peak shaving and valley filling" of photovoltaic output. During the day, when photovoltaic power is abundant, the heating network operates at low speed to store heat; at night, when there is a power shortage, the heating network operates at high speed to release the stored heat. The storage and release of heat balances power fluctuations, matching photovoltaic power generation with heat release during off-peak periods, while simultaneously optimizing power supply and heating methods. Attached Figure Description

[0015] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of some embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of this application. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings: Figure 1 This is a schematic diagram of the structure of a photovoltaic heat exchange integrated heating system according to an embodiment of this application.

[0016] in, Figure 1 The correspondence between the reference numerals and component names in the attached drawings is as follows: 100. Heating network module; 110. Primary network return water pipe; 111. Water temperature detection device; 120. Primary network supply water pipe; 121. Flow regulating valve; 122. Pressure sensor; 130. Secondary network supply water pipe; 140. Secondary network return water pipe; 150. Room temperature detection device; 200. Heat exchange station load module; 210. Circulating pump; 220. Makeup water pump; 230. Control cabinet; 300. Photovoltaic thermal device; 310. Photovoltaic module; 311. Photovoltaic array; 312. Photovoltaic combiner box; 313. Maximum power point tracking controller; 320. Solar thermal module; 321. Outlet water pipe; 3211. Bypass regulating valve; 322. Inlet water pipe; 400. Power management module; 410. Energy storage unit; 420. Control unit; 430. Grid-connected inverter; 20. Municipal power grid; 30. Heating building. Detailed Implementation

[0017] To better understand the above technical solutions, the technical solutions of the embodiments of this application will be described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the embodiments of this application and the specific features in the embodiments are detailed descriptions of the technical solutions of the embodiments of this application, rather than limitations on the technical solutions of this application. In the absence of conflict, the embodiments of this application and the technical features in the embodiments can be combined with each other.

[0018] The first aspect of this application provides a photovoltaic heat exchange integrated heating system, such as... Figure 1 As shown, the photovoltaic heat exchange integrated heating system includes: a heating pipeline module 100, a heat exchange station load module 200, a photovoltaic thermal device 300, and a power management module 400. The heat exchange station load module 200 controls the operation of the heating pipeline module 100 and includes a circulation pump 210, which controls the flow rate of the heating medium within the heating pipeline module 100. The photovoltaic thermal device 300 includes a photovoltaic module 310, which converts solar energy into electrical energy. The power management module 400 includes an energy storage unit 410 and a control unit 420. The photovoltaic module 310 and the energy storage unit 410 are connected. The control unit 420 is used to control the photovoltaic module 310 to provide power to the operation of the heat exchange station load module 200 when the photovoltaic power is in surplus. When the heat exchange station load module 200 has surplus power, the control unit 420 is used to control the energy storage unit 410 to store the electrical energy converted by the photovoltaic thermal device 300. When the energy storage unit 410 is fully charged and has surplus power, the control unit 420 is used to control the circulation pump 210 of the heat exchange station load module 200 to operate at the energy storage frequency. The control unit 420 is also used to control the energy storage unit 410 to discharge to the heat exchange station load module 200 and control the circulation pump 210 to operate at the rated frequency when the photovoltaic power is in short supply. The energy storage frequency is lower than the rated frequency.

[0019] In this embodiment, the heating network module 100 is located in the heating building 30. The heat exchange station load module 200 controls the operation of the heating network module 100 to control the heating state of the heating medium, for example, the heating medium is hot water. The circulation pump 210 of the heat exchange station controls the circulation speed of the heating medium within the heating network module 100. The photovoltaic thermal device 300 is a PVT (Photovoltaic-Thermal Collector) component. After the photovoltaic module 310 absorbs sunlight, it converts light energy into electrical energy to provide energy for the power management module 400. The control unit 420 of the power management module 400 is communicatively connected to both the photovoltaic module 310 and the energy storage unit 410, and determines the operating mode of the power management module 400 based on the operating state of the photovoltaic module 310. Exemplarily, the circulation pump 210 is a variable frequency pump, and the energy storage unit 410 can be a lithium iron phosphate battery pack.

[0020] The photovoltaic module 310 operates in two states: a photovoltaic power surplus state and a photovoltaic power deficit state. The control unit 420 first determines the operating status of the photovoltaic device. When there is sufficient sunlight during the day, the photovoltaic module 310 is in a photovoltaic power surplus state. The electrical energy converted by the photovoltaic module 310 is preferentially supplied to the operation of the heat exchange station load module 200. For example, the heat exchange station load module 200 also includes a water replenishment pump 220 and a PLC (Programmable Logic Controller) control cabinet 230. The photovoltaic module 310 provides electrical energy for the operation of the circulation pump 210, the water replenishment pump 220, and the PLC control cabinet 230. Then, when the heat exchange station load module 200 is operating normally and there is still surplus photovoltaic power, the control unit 420 controls the surplus power to charge the energy storage unit 410. When the energy storage is fully charged and there is still residual photovoltaic power, the control unit 420 activates the "thermal energy storage" mode, reduces the frequency of the circulation pump 210, and makes the circulation pump 210 operate at the energy storage frequency, for example, the energy storage frequency is 80% of the rated frequency, reduces the flow rate of the heating medium, prolongs the residence time of the heating medium in the heating network module 100, and makes the building envelope of the heating building 30 where the heating network module 100 is located absorb more heat, storing the excess electrical energy in the form of thermal energy in the heating network module 100 and the building body.

[0021] When the photovoltaic output is insufficient at night or during cloudy or rainy weather, the photovoltaic module 310 is in a state of photovoltaic power shortage. The control unit 420 controls the energy storage unit 410 to discharge to the heat exchange station load module 200 to supplement the power shortage and starts the "heat release" mode. The control unit 420 controls the energy storage unit 410 to increase the frequency of the circulation pump 210 to the rated frequency, accelerates the circulation of the heating medium in the heating network module 100, and releases the heat stored in the building envelope of the heating building 30.

[0022] This invention introduces renewable energy to achieve a deep coupling of "heat-assisted electricity and electricity-driven heat." It utilizes photovoltaic power to drive the power management module 400, organically integrating it to form a self-sufficient power supply device. Photovoltaic power is consumed locally and combined with grid power, reducing electricity costs for heat exchange stations and improving power supply reliability. Furthermore, it uses the thermal inertia of the heating network and building structure as virtual energy storage, overcoming the capacity limitations of electrical energy storage. The electrical energy storage unit 410 provides short-term electrical backup, while the thermal energy storage of the heating network provides long-term thermal backup. This combines the consumption of photovoltaic power with flexible adjustment of heating load, achieving "peak shaving and valley filling" of photovoltaic output. During the day, when photovoltaic power is abundant, the heating network operates at low speed to store heat; at night, when there is a power shortage, the heating network operates at high speed to release the stored heat. The storage and release of heat balances power fluctuations, matching photovoltaic power generation with heating heat release during off-peak hours, while optimizing power supply and heating methods.

[0023] For example, the photovoltaic module 310 includes a photovoltaic array 311, a photovoltaic combiner box 312, and a maximum power point tracking controller 313. The photovoltaic array 311 is connected to the maximum power point tracking controller 313 through the photovoltaic combiner box 312, and the output of the maximum power point tracking controller 313 is connected to the power management module 400. The control unit 420 is communicatively connected to the energy storage unit 410 and the maximum power point tracking controller 313.

[0024] In some embodiments provided in this application, such as Figure 1 As shown, the power management module 400 also includes a grid-connected inverter 430, which provides power to the heat exchange station load module 200. The DC side of the grid-connected inverter 430 is connected to the energy storage unit 410, and the AC side of the grid-connected inverter 430 is connected to both the heat exchange station load module 200 and the mains power grid 20. The control unit 420 is also used to control the grid-connected inverter 430 to provide mains power to the heat exchange station load module 200 when the energy storage unit 410's charge level is lower than a preset charge level.

[0025] In this embodiment, the energy storage unit 410 is electrically connected to both the maximum power point tracking controller 313 and the grid-connected inverter 430. The grid-connected inverter 430 converts the DC power provided by the photovoltaic module 310 into AC power required by the heat exchange station load module 200. The grid-connected inverter 430 is a bidirectional inverter with both rectification and inversion functions, establishing an AC / DC conversion and dual power supply path. The control unit 420 determines whether the energy storage unit 410's charge is lower than a preset charge, for example, the preset charge can be 30% of the rated charge. When the energy storage unit 410's charge is lower than the preset charge, it indicates that the energy storage margin is low. The control unit 420 controls the grid-connected inverter 430 to switch to the mains power grid 20 to provide mains power to the heat exchange station load module 200. This allows the module to draw power from the grid when photovoltaic output and energy storage are insufficient, ensuring the normal operation of the heat exchange station load module 200, improving operational and heating stability, and making the power supply mode of the heat exchange station load module 200 more flexible and intelligent.

[0026] In some embodiments provided in this application, the control unit 420 is also used to control the grid-connected inverter 430 to transmit electrical energy to the mains power grid 20 when the photovoltaic power is in surplus state.

[0027] In this embodiment, when the energy storage is fully charged and there is excess photovoltaic power generation, the control unit 420 feeds power to the grid 20 through the grid-connected inverter 430, transmitting the excess power to the grid 20, avoiding waste of photovoltaic power, improving the utilization rate of photovoltaic module 310 power generation, stratifying photovoltaic output, and improving the overall economic efficiency of the system.

[0028] In some embodiments provided in this application, such as Figure 1 As shown, the heating network module 100 includes a primary network return water pipe 110 and a primary network supply water pipe 120. The primary network return water pipe 110 is equipped with a water temperature detection device 111, and the primary network supply water pipe 120 is equipped with a flow regulating valve 121. The control unit 420 is also used to adjust the speed of the circulating pump 210 and / or the opening degree of the flow regulating valve 121 according to the return water temperature collected by the water temperature detection device 111.

[0029] In this embodiment, the primary network return water pipe 110 and primary network supply water pipe 120 of the heating network module 100 are respectively equipped with a water temperature detection element 111 and a flow regulating valve 121. For example, the water temperature detection element 111 can be a temperature sensor, and the flow regulating valve 121 can be an electric regulating valve. The water temperature detection element 111 is used to collect the return water temperature of the primary network, and the flow regulating valve 121 is used to control the supply water flow of the primary network. The control unit 420 is communicatively connected to the temperature detection element and the flow regulating valve 121. Based on the return water temperature, the control unit 420 adjusts the speed of the circulating pump 210 and / or the opening of the flow regulating valve 121 to control the flow rate of the heating medium, adjust the electrical load of the heat exchange station, and keep the return water temperature within a preset temperature range to maintain the power balance between the output of the photovoltaic module 310 and the load of the heat exchange station. The control unit 420 senses the change in the heat supply of the heat source in real time through the return water temperature of the primary network and adjusts the heat transfer of the heat exchange station load module 200 in conjunction to realize the automated dynamic adjustment of heat exchange.

[0030] For example, a pressure sensor 122 is provided at the inlet of the primary network to monitor the pressure of the heating medium flowing into the primary network.

[0031] In some embodiments provided in this application, such as Figure 1 As shown, the heating network module 100 also includes a secondary network water supply pipe 130 and a secondary network return water pipe 140. The photovoltaic thermal device 300 also includes a solar thermal module 320, which is used to heat the heating medium. The outlet pipe 321 of the solar thermal module 320 is connected to the secondary network water supply pipe 130, and the inlet pipe 322 of the solar thermal module 320 is connected to the secondary network return water pipe 140.

[0032] In this embodiment, the photovoltaic thermal device 300's solar thermal module 320 uses light energy and heat generated during operation to heat the heating medium. The outlet pipe 321 and inlet pipe 322 of the solar thermal module 320 are respectively connected to the secondary network of the heating network module 100. The heating medium heated by the solar thermal module 320 enters the secondary network water supply pipe 130 through the outlet pipe 321 for heating, increasing the inlet water temperature of the secondary network. The heating medium discharged from the secondary network return water pipe 140 flows back to the solar thermal module 320 through the inlet pipe 322 for heating. While realizing photovoltaic power generation, the photovoltaic thermal device 300 also utilizes recovered waste heat to supply heat to the heating network module 100, significantly improving the overall energy utilization efficiency and reducing the energy consumption of the heat exchange station load module 200.

[0033] In some embodiments provided in this application, such as Figure 1As shown, the heating network module 100 also includes a room temperature detection element 150 installed in the heating building 30, and the outlet water pipe 321 of the solar thermal module 320 is equipped with a bypass regulating valve 3211. The control unit 420 is also used to adjust the opening degree of the bypass regulating valve 3211 according to the indoor temperature collected by the room temperature detection element 150.

[0034] In this embodiment, a room temperature detection element 150 is provided on the inner side of the outer wall of the heated building 30. For example, the room temperature detection element 150 can be a temperature sensor. The room temperature detection element 150 is used to collect the indoor temperature of the heated building 30 to provide feedback on the user's thermal comfort. The bypass regulating valve 3211 can regulate the flow rate of the outlet water pipe 321 of the solar thermal module 320. The control unit 420 is communicatively connected to the room temperature detection element 150 and the bypass regulating valve 3211 respectively. When the photovoltaic module 310 is in a state of surplus photovoltaic power, the control unit 420 adjusts the opening of the bypass regulating valve 3211 based on the indoor temperature to keep the indoor temperature within a comfortable range, so as to achieve flexible adjustment of heat load, accurately match the heating demand and the waste heat supply of the solar thermal module 320, realize on-demand heating, and improve heating comfort.

[0035] For example, when the indoor temperature is low, the control unit 420 increases the opening of the bypass regulating valve 3211, increasing the heat supply flow of the solar thermal module 320, and using the waste heat from the photovoltaic system to heat the return water. When the indoor temperature is high, the control unit 420 decreases the opening of the bypass regulating valve 3211, reducing the heat supply flow of the solar thermal module 320.

[0036] In some embodiments provided in this application, such as Figure 1 As shown, the heat exchange station load module 200 also includes a water supply pump 220, which is used to supplement the heating medium to the heating network module 100. The capacity configuration of the energy storage unit 410 is sufficient to allow the circulating pump 210 and the water supply pump 220 to operate continuously for 2 to 4 hours.

[0037] In this embodiment, the makeup water pump 220 replenishes the heating medium to the heating network module 100, ensuring that the heating medium meets the heating demand. The capacity configuration of the energy storage unit 410 is sufficient to support the continuous operation of the circulation pump 210 and the makeup water pump 220 for 2 to 4 hours. The ample power can support the long-term operation of the core components of the heat exchange station load module 200, improving the stability of the heat exchange station load module 200 operation and enhancing the off-grid buffer capability of the system. Furthermore, the ample power of the energy storage unit 410 reduces the amount of grid power required, lowering electricity purchase costs.

[0038] In one specific embodiment, the heating system of this application is deployed in a heat exchange station in a northern city. The heat exchange station load module 200 is located within the heat exchange station, and the heating area of ​​the heating pipeline module 100 is approximately 500 square meters. The photovoltaic array 311 uses 320Wp monocrystalline silicon modules and is installed on the roof of the heat exchange station building.

[0039] During the operation of the heating system, the control unit 420 monitors the output power of the photovoltaic module 310 and the load power of the heat exchange station in real time. When there is sufficient sunlight during the day, the photovoltaic power generation prioritizes the operation of the heat exchange station equipment, and the surplus electricity charges the energy storage unit 410 through the bidirectional inverter. After the energy storage is fully charged, if the control unit 420 determines that there is still surplus electricity in the photovoltaic system, it activates the "thermal energy storage" mode: by reducing the frequency of the circulating pump 210 to 80% of the rated frequency, the residence time of hot water in the pipe network is extended, allowing the building envelope to absorb more heat, and storing the excess electrical energy as thermal energy in the heating pipe network and the building itself.

[0040] When photovoltaic output is insufficient at night or during cloudy or rainy weather, the control unit 420 activates the "heat release" mode: increasing the frequency of the circulation pump 210 to the rated frequency, accelerating the circulation of hot water in the pipe network, and releasing the heat stored in the building envelope. At the same time, the energy storage unit 410 discharges to supplement the power gap, and automatically switches to mains power supplementation when the stored energy is below 30%.

[0041] By replacing conventional photovoltaic modules with PVT modules, PVT modules can recover waste heat while generating electricity, raising the return water temperature of the secondary network by 2°C to 4°C and directly contributing to the heating load. The overall energy utilization efficiency of the heating system is about 40% higher than that of a single photovoltaic solution.

[0042] A second aspect of this application provides a control method for an integrated photovoltaic heat exchange heating system. This control method is used in any of the aforementioned integrated photovoltaic heat exchange heating systems and includes: Step 1: Determine the operating status of the photovoltaic device; Step 2: When the photovoltaic power surplus is in operation, control the photovoltaic modules to provide power to the load modules of the heat exchange station; Step 3: When the load module of the heat exchange station has surplus power, control the energy storage unit to store the electrical energy converted by the photovoltaic thermal device; Step 4: When the energy storage unit is fully charged and has residual power, control the circulating pump of the heat exchange station load module to run at the energy storage frequency; Step 5: When the photovoltaic power shortage is in operation, control the energy storage unit to discharge to the load module of the heat exchange station, and control the circulating pump to run at the rated frequency; Among them, the energy storage frequency is lower than the rated frequency.

[0043] In this embodiment, the photovoltaic module's operating state includes a photovoltaic power surplus state and a photovoltaic power deficit state. The control unit first determines the photovoltaic device's operating state. When there is sufficient sunlight during the day, the photovoltaic module is in a photovoltaic power surplus state. The control unit executes steps 2 to 4: the electrical energy converted by the photovoltaic module is preferentially supplied to the operation of the heat exchange station load module. Then, if the heat exchange station load module is operating normally and there is still surplus photovoltaic power, the control unit executes step 3 to control the surplus power to charge the energy storage unit. After the energy storage is fully charged and there is still surplus photovoltaic power, the control unit executes step 4 to activate the "thermal energy storage" mode, reducing the circulation pump frequency to operate at the energy storage frequency, for example, 80% of the rated frequency. This reduces the flow rate of the heating medium, prolongs the residence time of the heating medium in the heating network module, and allows the building envelope where the heating network module is located to absorb more heat, storing the excess electrical energy as thermal energy in the heating network module and the building body.

[0044] When the photovoltaic output is insufficient at night or during cloudy or rainy weather, the photovoltaic module is in a state of photovoltaic power shortage. The control unit executes step 5: The control unit controls the energy storage unit to discharge to the load module of the heat exchange station to supplement the power shortage, and starts the "heat release" mode. The control unit controls the energy storage unit to increase the frequency of the circulation pump to the rated frequency, accelerates the circulation of the heating medium in the heating network module, and releases the heat stored in the building envelope of the heating building.

[0045] This invention introduces renewable energy to achieve a deep coupling of "heat-assisted electricity and electricity-driven heat." It utilizes photovoltaic power to drive a power management module, organically integrating them to form a self-sufficient power supply device. Photovoltaic power is consumed locally and combined with grid power, reducing electricity costs for heat exchange stations and improving power supply reliability. Furthermore, it uses the thermal inertia of the heating network and the building itself as virtual energy storage, overcoming the capacity limitations of electrical energy storage. The electrical energy storage unit provides short-term electrical backup, while the thermal energy storage of the heating network provides long-term thermal backup. This combines the consumption of photovoltaic power with flexible adjustment of heating load, achieving "peak shaving and valley filling" of photovoltaic output. During the day, when photovoltaic power is abundant, the heating network operates at low speed to store heat; at night, when there is a power shortage, the heating network operates at high speed to release the stored heat. The storage and release of heat balances power fluctuations, matching photovoltaic power generation with heat release during off-peak periods, while simultaneously optimizing power supply and heating methods.

[0046] In some embodiments provided in this application, step 5, which involves controlling the energy storage unit to discharge to the load module of the heat exchange station and controlling the circulating pump to operate at the rated frequency when the operating state is a photovoltaic power shortage state, specifically includes: Step 51: When the energy storage unit's power is lower than the preset power, control the grid-connected inverter to supply mains power to the heat exchange station load module.

[0047] In this embodiment, the control unit determines whether the energy storage unit's power is lower than a preset power level. For example, the preset power level can be 30% of the rated power level. When the energy storage unit's power is lower than the preset power level, it indicates that the energy storage margin is low. The control unit controls the grid-connected inverter to switch to the mains power grid to provide mains power to the heat exchange station load module. This allows the unit to draw power from the grid when photovoltaic output and energy storage are insufficient, ensuring the normal operation of the heat exchange station load module, improving operation and heating stability, and making the power supply mode of the heat exchange station load module more flexible and intelligent.

[0048] In some embodiments provided in this application, step 4, which controls the circulating pump of the heat exchange station load module to operate at the energy storage frequency when the energy storage unit is fully charged and has surplus power, specifically includes: Step 41: Control the grid-connected inverter to supply power to the mains power grid.

[0049] In this embodiment, when the energy storage is fully charged and there is excess photovoltaic power generation, the control unit feeds power to the grid through the grid-connected inverter, transmitting the excess power to the grid to avoid wasting photovoltaic power, improve the utilization rate of photovoltaic module power generation, digest photovoltaic output in layers, and improve the overall economic efficiency of the system.

[0050] In this invention, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance; the term "multiple" refers to two or more unless otherwise explicitly defined. The terms "install," "connect," "link," and "fix" should be interpreted broadly. For example, "connect" can be a fixed connection, a detachable connection, or an integral connection; "link" can be a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0051] In the description of this invention, it should be understood that the terms "upper," "lower," "left," "right," "front," "rear," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or unit referred to must have a specific orientation or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0052] In the description of this specification, the terms "one embodiment," "some embodiments," "specific embodiment," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0053] The above are merely some embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention can have various modifications and variations. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A photovoltaic heat exchange integrated heating system, characterized in that, include: Heating network module; A heat exchange station load module is used to control the operation of the heating network module. The heat exchange station load module includes a circulation pump, which is used to control the flow rate of the heating medium in the heating network module. A photovoltaic thermal device includes a photovoltaic module, which is used to convert light energy into electrical energy; The power management module includes an energy storage unit and a control unit. The photovoltaic module and the energy storage unit are connected. The control unit is used to control the photovoltaic module to provide power to the operation of the heat exchange station load module when the photovoltaic power is in surplus state. When the heat exchange station load module has surplus power, the control unit controls the energy storage unit to store photovoltaic power. When the energy storage unit is fully charged and has surplus power, the control unit controls the circulating pump to operate at the energy storage frequency. The control unit is also used to control the energy storage unit to discharge to the heat exchange station load module and control the circulating pump to operate at the rated frequency when the photovoltaic power is in short supply state, wherein the energy storage frequency is lower than the rated frequency.

2. The photovoltaic heat exchange integrated heating system according to claim 1, characterized in that, The power management module also includes: A grid-connected inverter is used to provide power to the load module of the heat exchange station. The DC side of the grid-connected inverter is connected to the energy storage unit, and the AC side of the grid-connected inverter is connected to the load module of the heat exchange station and the mains power grid respectively. The control unit is also used to control the grid-connected inverter to provide mains power to the heat exchange station load module when the energy storage unit's power is lower than a preset power.

3. The photovoltaic heat exchange integrated heating system according to claim 2, characterized in that, The control unit is also used to control the grid-connected inverter to transmit electrical energy to the mains power grid when there is a surplus of photovoltaic power.

4. The photovoltaic heat exchange integrated heating system according to any one of claims 1 to 3, characterized in that, The heating network module includes: The primary network return water pipeline and the primary network supply water pipeline are provided. The primary network return water pipeline is equipped with a water temperature detection device, and the primary network supply water pipeline is equipped with a flow regulating valve. The control unit is also used to adjust the speed of the circulation pump and / or the opening of the flow regulating valve according to the return water temperature collected by the water temperature detection device.

5. The photovoltaic heat exchange integrated heating system according to any one of claims 1 to 3, characterized in that, The heating network module also includes: Secondary water supply pipelines and secondary water return pipelines; The photovoltaic thermal device also includes: A solar thermal module is used to heat the heating medium. The outlet pipe of the solar thermal module is connected to the secondary network water supply pipe, and the inlet pipe of the solar thermal module is connected to the secondary network return pipe.

6. The photovoltaic heat exchange integrated heating system according to any one of claims 1 to 3, characterized in that, The heating network module also includes a room temperature detection device installed in the heating building, and the water outlet pipe of the solar thermal module is equipped with a bypass regulating valve. The control unit is also used to adjust the opening degree of the bypass regulating valve according to the indoor temperature collected by the room temperature detection device.

7. The photovoltaic heat exchange integrated heating system according to any one of claims 1 to 3, characterized in that, The heat exchange station load module also includes: A water supply pump is used to replenish the heating medium to the heating network module. The capacity configuration of the energy storage unit is sufficient to allow the circulating pump and the water supply pump to operate continuously for 2 to 4 hours.

8. A control method for a photovoltaic heat exchange integrated heating system, characterized in that, For a photovoltaic heat exchanger integrated heating system as described in any one of claims 1 to 7, the control method includes: Determine the operating status of the photovoltaic device; When the operating state is a photovoltaic power surplus state, the energy storage unit is controlled to store the electrical energy converted by the photovoltaic thermal device; When the energy storage unit is fully charged and has surplus power, the circulating pump of the heat exchange station load module is controlled to operate at the energy storage frequency. When the operating state is a photovoltaic power shortage state, the energy storage unit is controlled to discharge to the load module of the heat exchange station, and the circulating pump is controlled to operate at the rated frequency; The energy storage frequency is lower than the rated frequency.

9. The control method for the photovoltaic heat exchange integrated heating system according to claim 8, characterized in that, When the operating state is a photovoltaic power shortage state, the steps of controlling the energy storage unit to discharge to the load module of the heat exchange station and controlling the circulating pump to operate at the rated frequency specifically include: When the energy storage unit's charge is lower than the preset charge, the grid-connected inverter is controlled to supply mains power to the heat exchange station load module.

10. The control method for the photovoltaic heat exchange integrated heating system according to claim 8 or 9, characterized in that, When the energy storage unit is fully charged and has residual power, the step of controlling the circulating pump of the heat exchange station load module to operate at the energy storage frequency specifically includes: Control the grid-connected inverter to deliver electrical energy to the mains power grid.

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