Photovoltaic photo-thermal combined cooling heating and power system integrated with electrochemical cycle of heat regeneration and operation method thereof

Abstract

The present application relates to the technical field of solar comprehensive utilization and thermo-electrochemical conversion, in particular to a photovoltaic-thermal combined heat and power system integrated with heat regenerative electrochemical cycle and operation method, comprising an intelligent control unit, a PV / T module and a TREC module, the PV / T module is a multilayer composite structure, comprising a glass cover plate, an air gap, a photovoltaic cell layer, a heat absorption plate, a heat exchange channel and a thermal insulation layer arranged in turn from top to bottom; the TREC module is coupled with the PV / T module through the heat exchange channel and the circuit pipeline, and operates in one of the power generation mode and the refrigeration mode based on the principle of thermo-electrochemical reaction, the TREC module comprises at least one TREC cell unit, a positive electrode liquid storage tank, a negative electrode liquid storage tank and an out-of-cavity flow channel. The present application realizes efficient combined heat and power supply through the step-by-step utilization of solar spectrum and the flexible switching of system functions, and significantly improves the comprehensive energy output of unit area solar energy collection surface.

Description

Technical Field

[0001] This invention relates to the field of solar energy comprehensive utilization and thermo-electrochemical energy conversion technology, specifically to a photovoltaic combined heat and power system and its operation method that integrates a thermal regeneration electrochemical cycle. Background Technology

[0002] Solar energy is a core pillar of my country's energy system, and its efficient utilization is key to achieving the "dual carbon" goal. Photovoltaic and solar thermal integrated utilization technology, by segmenting the solar spectrum, can theoretically significantly improve the overall utilization rate of solar energy. Existing PV / T systems face two major bottlenecks in practical applications: First, there is a significant "thermal-electricity contradiction." The power generation efficiency of photovoltaic cells decreases significantly with increasing operating temperature. To ensure high photoelectric conversion efficiency, the system must limit the heat collection temperature, leading to a decrease in the quality of recovered heat energy and creating a dilemma of "one side failing to provide power generation, the other providing heat." Second, there are functional deficiencies. Traditional PV / T systems can only generate electricity and heat, lacking active cooling capabilities and failing to form a complete combined cooling, heating, and power system, making it difficult to meet the peak summer cooling demands of building energy systems, which are strongly correlated with solar irradiance.

[0003] Existing technologies that couple PV / T with organic Rankine cycles, thermoelectric modules, etc., generally suffer from complex system structures, low thermoelectric conversion efficiency, high costs, and prominent thermoelectric contradictions. Therefore, they do not meet current needs. To address this, we propose a photovoltaic combined heat and power system and its operation method that integrates a thermal regeneration electrochemical cycle. Summary of the Invention

[0004] The purpose of this invention is to provide a photovoltaic combined heat and power system and operation method that integrates a thermal regeneration electrochemical cycle, in order to solve the problems mentioned in the background art, such as complex system structure, low thermoelectric conversion efficiency, high cost, and prominent thermoelectric contradictions, when coupling PV / T with organic Rankine cycles, thermoelectric modules and other technologies.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a photovoltaic combined heat and power system and operation method integrating thermal regeneration electrochemical cycle, including an intelligent control unit, a PV / T module and a TREC module, wherein the PV / T module is a multi-layer composite structure, including a glass cover plate, an air gap, a photovoltaic cell layer, a heat absorber plate, a heat exchange channel and a heat insulation layer arranged from top to bottom; The TREC module and the PV / T module are connected by a thermo-electric dual-path coupling through heat exchange channels and circuit lines, and operate in one of the two modes of power generation and cooling based on the thermo-electrochemical reaction principle. The TREC module includes at least one TREC battery cell, a positive electrode storage tank, a negative electrode storage tank, and an external flow channel. The intelligent control unit is connected to the PV / T module and the TREC module via electrical signals and power circuits, respectively. The intelligent control unit regulates the flow rate of the fluid pump group and the charging and discharging direction of the TREC battery group according to real-time meteorological data, system operating parameters and preset control strategies, and realizes flexible adaptive switching between the photovoltaic-thermal-cooling-power combined system in power generation efficiency enhancement mode, electrochemical cooling mode and combined cooling-heating-power mode.

[0006] Preferably, the photovoltaic cell layer is used to mainly absorb the visible-near infrared band of solar radiation and realize photoelectric conversion. The heat-absorbing plate is used to conduct heat collection of mid- and far-infrared radiation that is not utilized by photovoltaics and the heat generated during the operation of the photovoltaic cell layer. The heat exchange channel is provided with a continuously flowing heat exchange medium. The heat exchange channel continuously carries away the heat collected by the heat-absorbing plate through the heat exchange medium and forms a low-grade heat energy output. The glass cover is made of low-iron, high-transparency tempered glass; the air gap is an air insulation layer with a thickness of 15mm; the photovoltaic cell layer is a high-conversion-rate crystalline silicon cell; the heat-absorbing plate is a copper plate with a selective absorption coating on its surface; and the insulation layer is polyurethane foam.

[0007] Preferably, a first three-way valve is fixedly installed at the inlet end of the heat exchange channel. The first three-way valve is used to switch the source of the working fluid entering the heat exchange channel. A second three-way valve is fixedly installed at the outlet end of the heat exchange channel. The inner side of the second three-way valve is provided with a main channel, a first branch channel, and a second branch channel. The main channel is connected to the outlet of the heat exchange channel. The first branch channel is used to connect to an external heat-using terminal. The second branch channel is connected to the inlet of the external channel. The valve core opening of the second three-way valve is adjusted by the intelligent control unit according to the operating mode and realizes the on-demand directional distribution of heat.

[0008] Preferably, both the heat exchange channel and the external channel are serpentine microchannel tubes. The external channel is arranged in close contact with the outer wall of the TREC battery cell. The inlet end of the external channel is connected to the second branch and receives the high-temperature heat exchange medium from the PV / T module. A third three-way valve is fixedly installed at the outlet end of the external channel. The third three-way valve has a first inlet and a second inlet. The first inlet of the third three-way valve is connected to the outlet end of the external channel. The second inlet of the third three-way valve is connected to an external cooling circulating water circuit. The outlet end of the third three-way valve is connected to the first three-way valve.

[0009] Preferably, the TREC battery cell includes a positive electrode, a negative electrode, an ion exchange membrane, a positive electrolyte, and a negative electrolyte. The ion exchange membrane is disposed between the positive and negative electrodes. The positive and negative electrolytes fill the closed cavities between the positive electrode and the ion exchange membrane and between the negative electrode and the ion exchange membrane, respectively. The positive and negative electrolytes are aqueous solutions containing dissolved active substances required for the electrochemical reaction. The ion exchange membrane allows active ions to pass through in a directional manner.

[0010] Preferably, the positive electrode storage tank and the negative electrode storage tank are respectively connected to the positive electrode side flow channel and the negative electrode side flow channel of the TREC battery cell through pipelines. The positive electrode storage tank and the negative electrode storage tank are used to store and circulate the electrolyte, and also have the functions of working fluid buffer, thermal energy storage and flow regulation. Temperature sensors and liquid level sensors are installed inside the positive electrode storage tank and the negative electrode storage tank. The intelligent control unit monitors the thermal state of the working fluid and the liquid volume change in real time through the temperature sensors and the liquid level sensors.

[0011] Preferably, the volumes of the positive and negative electrode storage tanks are determined by the scale of the photovoltaic combined solar power system, and the heat collection areas of the positive and negative electrode storage tanks are adapted to the heat generation rate of the PV / T module and the heat dissipation rate of the TREC module.

[0012] Preferably, the hardware structure layer of the intelligent control unit consists of a microprocessor, a memory, and multiple I / O interfaces. The microprocessor is either an industrial-grade microcontroller or a programmable logic controller. The memory is used to pre-store control programs and historical operating strategies. The system operating parameters include, but are not limited to, the temperature of the hot water storage tank, the temperature of the photovoltaic cells, and the building's terminal heating and cooling load requirements.

[0013] An operation method for a photovoltaic-thermal-cooled combined heat and power (CHP) system integrating a thermal regeneration electrochemical cycle includes a TREC thermal-driven efficiency-enhancing power generation mode, a TREC electric-driven active cooling mode, and a TREC CHP mode. The TREC thermal-driven efficiency-enhancing power generation mode is a power generation efficiency-enhancing mode, the TREC electric-driven active cooling mode is an electrochemical cooling mode, and the TREC CHP mode is a CHP mode. The activation condition for the TREC thermal-driven efficiency-enhancing power generation mode is that the electricity demand exceeds the energy supply threshold. The activation condition for the TREC electric-driven active cooling mode is that the cooling demand exceeds a set threshold and photovoltaic power generation is sufficient. The activation condition for the TREC CHP mode is that the user side simultaneously has electricity, heating, and cooling demands and sufficient irradiance. When the photovoltaic-thermal combined cooling, heating, and power (PV / T) system is in TREC (True Energy Conversion) mode, the intelligent control unit coordinates and controls the PV / T module and the TREC module, allowing them to operate simultaneously. The PV / T module receives solar radiation to generate direct current, which is then fed into the power grid, used by external loads, and used to drive the TREC battery cells configured in cooling mode for reverse cooling. The heat exchange medium in the heat exchange channel absorbs low-temperature heat energy through the absorber plate and is distributed by the intelligent control unit. The low-temperature heat energy is divided into two groups. One group of the low-temperature heat energy is directly delivered to external heat-using terminals to supply heat energy, while the other group of the low-temperature heat energy flows to the TREC battery cells configured in power generation mode, driving the TREC battery cells to perform a thermodynamic forward cycle to output additional electrical energy. In TREC mode, the PV / T system can simultaneously output electrical energy, heat energy, and cooling energy through independent group control of the TREC battery cells, achieving comprehensive utilization of solar energy.

[0014] When the photovoltaic-thermal combined cooling, heating and power system is in TREC heat-driven efficiency-enhancing power generation mode, the heat exchange medium flows sequentially through the heat absorber plate and heat exchange channel to absorb and heat up low-grade heat energy and heat the TREC battery cells, thereby driving the TREC battery cells to perform a power generation cycle. The power generation cycle includes the following steps: A1: The heat exchange medium carrying low-grade heat energy heats the TREC battery cell, raising its temperature to a preset high temperature value. Since the selected TREC battery cell has a negative temperature coefficient, its open circuit voltage decreases accordingly. A2: Under high temperature conditions, the power generated by the photovoltaic thermal module and the external power supply are used to charge the TREC battery cell at low voltage constant current. The entropy increase reaction occurs inside the battery and it continuously absorbs heat from the heat exchange medium. A3: Cut off the input of heat exchange medium, so that the TREC battery cell can exchange heat with the external environment, so that the temperature of the TREC battery cell drops to the preset low temperature value, and the open circuit voltage increases accordingly. A4: At low temperatures, the TREC battery cell undergoes high-voltage discharge through the external circuit. An entropy reduction reaction occurs inside the TREC battery cell, releasing heat to the environment. Since the discharge voltage is higher than the charging voltage, the electrical energy output by the system is greater than the electrical energy consumed during the charging phase, thus outputting net electrical work to complete one power generation cycle. Repeating the above cycle achieves continuous efficiency-enhancing power generation. When the photovoltaic combined solar power system is in TREC electrically driven active cooling mode, the intelligent control unit uses the electrical energy generated by the PV / T module to drive the TREC module to run in reverse and execute a cooling cycle based on the Brayton cycle. The cooling cycle includes the following steps: B1: The electrical energy generated by the photovoltaic effect of the PV / T module drives the TREC battery cell to be charged at a constant current in an isentropic state. An entropy-increasing electrochemical reaction occurs inside the TREC battery cell, causing the temperature of the TREC battery cell to continuously decrease until the charging is completed. The TREC battery cell reaches the preset temperature, which is much lower than the target cooling space temperature. B2: After charging is complete, the charging circuit is cut off. The TREC battery cell does not undergo electrochemical reaction. Since the battery temperature is much lower than the target cooling space temperature, the TREC battery cell achieves cooling through heat exchange with the environment. B3: When the TREC battery cell is at the same temperature as the target cooling space, the TREC battery cell discharges through the external circuit. The TREC battery cell undergoes an entropy reduction reaction, causing the TREC battery cell temperature to rise continuously until the discharge is complete. The TREC battery cell then reaches the preset temperature, and the battery temperature is much higher than the external high temperature environment temperature. B4: After discharge is complete, the discharge circuit is cut off. The TREC battery cell cools down by releasing heat to the external environment and returns to the preset low temperature state, ready to enter the next cycle. The above cycle is repeated to achieve continuous active cooling.

[0015] Compared with the prior art, the beneficial effects of the present invention are: 1. This invention deeply couples the PV / T module with the TREC module, and uses the low-grade waste heat generated by the PV / T module to directly drive the TREC module to generate secondary power. This provides active cooling for the photovoltaic cells, improves their photoelectric conversion efficiency, and converts the originally lost waste heat into high-grade electrical energy, realizing efficient cascade utilization of the solar spectrum and effectively breaking through the bottleneck of the "thermal-electric contradiction" in traditional PV / T systems.

[0016] 2. This invention fully utilizes the dual-mode operation capability of TREC technology. In addition to providing electricity and heat, it further endows the system with efficient active cooling function. In cooling mode, it uses photovoltaic power to drive TREC to achieve electrochemical cooling. Through the combined cooling, heating and power mode, the system can simultaneously output electrical energy, heat energy and cooling energy, realizing the full spectrum cascade utilization of solar spectrum. It provides a high-efficiency, low-cost and environmentally friendly comprehensive energy solution for building energy conservation, industrial waste heat recovery and independent power supply in remote areas.

[0017] 3. This invention achieves closed-loop circulation, on-demand distribution, and rapid switching of heat between the PV / T module and the TREC module by setting three-way valves at the inlet and outlet of the PV / T module and the outlet of the heat exchange channel of the TREC module, and by having the intelligent control unit coordinate and regulate the valve core opening of the three three-way valves. This enables the system to smoothly transition between the three modes of power generation, cooling, and combined heat and power, avoids disordered working fluid flow or heat loss, and further improves the stability and overall energy efficiency of the system operation. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the overall energy flow of the present invention; Figure 2 This is a schematic diagram of the thermodynamic cycle (TS) of the TREC module of the present invention; Figure 3 This is a schematic diagram of the operation of the TREC thermal-driven efficiency-enhancing power generation mode of the present invention; Figure 4 This is a schematic diagram of the operation of the TREC electrically driven active cooling mode of the present invention; Figure 5 This is a schematic diagram of the operation of the TREC combined cooling, heating and power mode of the present invention.

[0019] In the diagram: 1. Intelligent control unit; 2. PV / T module; 201. Glass cover plate; 202. Air gap; 203. Photovoltaic cell layer; 204. Heat absorber plate; 205. Heat exchange channel; 206. Insulation layer; 207. First three-way valve; 208. Second three-way valve; 3. TREC module; 301. Battery positive electrode; 302. Battery negative electrode; 303. Ion exchange membrane; 304. Positive electrode storage tank; 305. Negative electrode storage tank; 306. External flow channel; 307. Third three-way valve. Detailed Implementation

[0020] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0021] Please see Figure 1 This invention provides an embodiment of a photovoltaic combined heat and power (CHP) system and its operation method that integrates thermal regeneration electrochemical cycles. The system includes an intelligent control unit 1, a PV / T module 2, and a TREC module 3. The PV / T module 2 is a multi-layered composite structure, comprising, from top to bottom, a glass cover plate 201, an air gap 202, a photovoltaic cell layer 203, a heat absorber plate 204, a heat exchange channel 205, and a heat insulation layer 206. A first three-way valve 207 is fixedly installed at the inlet end of the heat exchange channel 205. 7 is used to switch the source of the working fluid entering the heat exchange channel 205. A second three-way valve 208 is fixedly installed at the outlet end of the heat exchange channel 205. The inner side of the second three-way valve 208 is provided with a main road, a first branch road and a second branch road respectively. The main road is connected to the outlet of the heat exchange channel 205. The first branch road is used to connect to the external heat terminal. The second branch road is connected to the inlet of the external flow channel 306. The valve core opening of the second three-way valve 208 is adjusted by the intelligent control unit 1 according to the operation mode and realizes the on-demand directional distribution of heat. The photovoltaic cell layer 203 is mainly used to absorb the visible-near infrared band of solar radiation and realize photoelectric conversion. The heat absorber plate 204 is used to conduct heat collection for the mid-far infrared radiation that is not utilized by photovoltaics and the heat generated during the operation of the photovoltaic cell layer 203. The heat exchange channel 205 is equipped with a continuously flowing heat exchange medium. The heat exchange channel 205 continuously removes the heat collected by the heat absorber plate 204 through the heat exchange medium and forms a low-grade heat energy output. The TREC module 3 and the PV / T module 2 are connected by thermal-electric dual-path coupling through the heat exchange channel 205 and the circuit pipeline, and operate in one of the two modes of power generation and cooling based on the thermo-electrochemical reaction principle. The glass cover plate 201 is low-iron high-transparency tempered glass, the air gap 202 is an air insulation layer with a thickness of 15mm, the photovoltaic cell layer 203 is a high-conversion-rate crystalline silicon cell, the heat absorber plate 204 is a copper plate with a selective absorption coating on the surface, and the insulation layer 206 is polyurethane foam.

[0022] Please see Figure 1 and Figure 2 The TREC module 3 includes at least one TREC battery cell, a positive electrode storage tank 304, a negative electrode storage tank 305, and an external flow channel 306. Both the heat exchange flow channel 205 and the external flow channel 306 are serpentine microchannel tubes. The external flow channel 306 is arranged in close contact with the outer wall of the TREC battery cell. The inlet end of the external flow channel 306 is connected to the second branch and receives the high-temperature heat exchange medium from the PV / T module 2. A third three-way valve 307 is fixedly installed at the outlet end of the external flow channel 306. The third three-way valve 307 is provided with a first inlet and a second inlet. The first inlet of the third three-way valve 307 is connected to the outlet end of the external flow channel 306. The second inlet of the third three-way valve 307 is connected to an external cooling circulating water circuit. The outlet end of the third three-way valve 307 is connected to the first three-way valve 207. The TREC battery cell includes a positive electrode 301, a negative electrode 302, an ion exchange membrane 303, a positive electrolyte, and a negative electrolyte. The ion exchange membrane 303 is disposed between the positive electrode 301 and the negative electrode 302. The positive electrolyte and the negative electrolyte are respectively filled in the closed cavities between the positive electrode 301 and the ion exchange membrane 303 and between the negative electrode 302 and the ion exchange membrane 303. The positive electrolyte and the negative electrolyte are water-based solutions containing active substances required for electrochemical reactions. The ion exchange membrane 303 allows active ions to pass through in a directional manner. The positive electrode storage tank 304 and the negative electrode storage tank 305 are connected to the positive electrode side flow channel and the negative electrode side flow channel of the TREC battery cell through pipelines, respectively. The positive electrode storage tank 304 and the negative electrode storage tank 305 are used to store and circulate the electrolyte, and also have the functions of working fluid buffer, thermal energy storage and flow regulation. The volume of the positive electrode storage tank 304 and the negative electrode storage tank 305 is determined by the scale of the photovoltaic combined heat and power system. The heat collection area of ​​the positive electrode storage tank 304 and the negative electrode storage tank 305 is adapted to the heat generation rate of the PV / T module 2 and the heat dissipation rate of the TREC module 3.

[0023] Please see Figure 1 The intelligent control unit 1 is connected to the PV / T module 2 and the TREC module 3 by electrical signals and power circuits. The intelligent control unit 1 regulates the flow rate of the fluid pump group and the charging and discharging direction of the TREC battery group according to real-time meteorological data, system operating parameters and preset control strategies, and realizes flexible adaptive switching between power generation efficiency mode, electrochemical cooling mode and combined cooling, heating and power mode of the photovoltaic thermal combined cooling and power system. Temperature sensors and liquid level sensors are installed inside the positive electrode storage tank 304 and the negative electrode storage tank 305. The intelligent control unit 1 monitors the thermal state and liquid volume changes of the working fluid in real time through the temperature sensors and liquid level sensors. The hardware structure layer of the intelligent control unit 1 consists of a microprocessor, memory and multiple I / O interfaces. The microprocessor is either an industrial-grade microcontroller or a programmable logic controller. The memory is used to pre-store the control program and historical operating strategies. The system operating parameters include, but are not limited to, the temperature of the hot water storage tank, the temperature of the photovoltaic cell and the cooling and heating load requirements of the building terminal.

[0024] An operation method for a photovoltaic-thermal-cooled combined heat and power (CHP) system integrating thermal regeneration electrochemical cycle includes a TREC thermal-driven efficiency-enhancing power generation mode, a TREC electric-driven active cooling mode, and a TREC CHP mode. The TREC thermal-driven efficiency-enhancing power generation mode is a power generation efficiency-enhancing mode, the TREC electric-driven active cooling mode is an electrochemical cooling mode, and the TREC CHP mode is a CHP mode. The activation condition for the TREC thermal-driven efficiency-enhancing power generation mode is that the electricity demand exceeds the energy supply threshold. The activation condition for the TREC electric-driven active cooling mode is that the cooling demand exceeds a set threshold and the photovoltaic power generation is sufficient. The activation condition for the TREC CHP mode is that the user side has simultaneous electricity, heating, and cooling demands and sufficient irradiance. Please see Figure 3 Example 1: TREC thermal-driven enhanced power generation mode The second branch of the second three-way valve 208 leading to the TREC module is opened, and the first branch leading to the user-side heating terminal is closed. The outlet of the third three-way valve 307 is switched to one side of the first three-way valve 207, and the system only outputs electrical energy to the user side. Initially, the positive and negative electrolytes are stored in corresponding positive electrode storage tank 304 and negative electrode storage tank 305, respectively. As the system receives solar radiation, the photovoltaic cell layer 203 outputs DC power. After detecting the power output signal from the PV / T module 2, the intelligent control unit 1 opens the valve and fluid pump on the pipeline connecting the storage tank and the TREC battery cell, allowing the electrolyte to circulate from the storage tank into the corresponding cavity of the TREC battery cell. Simultaneously, the heat exchange medium in the heat exchange channel 205 absorbs low-grade heat energy and heats up as it flows through the area of ​​the heat absorber plate 204. Subsequently, the intelligent control unit 1 controls the second three-way valve 208. The flow direction is switched by closing the first branch leading to the external heat terminal and opening the second branch leading to the external flow channel 306 in the TREC module 3. This allows all the heat exchange medium carrying low-grade heat energy to flow to the external flow channel 306 outside the TREC battery cell to heat the TREC battery cell. At the same time, the intelligent control unit 1 controls the third three-way valve 307 to switch the outlet to the side of the first three-way valve 207, so that the cooled heat exchange medium returns to the heat exchange channel 205 in the PV / T module 2 for recirculation and heating. This forms a closed thermal circulation loop between the PV / T module and the TREC module. The closed thermal circulation loop includes the following steps: A1: The heat exchange medium carrying low-grade heat energy heats the TREC battery cell, raising its temperature to a preset high temperature value. Since the selected TREC battery cell has a negative temperature coefficient, its open circuit voltage decreases accordingly. A2: Under high temperature conditions, the power generated by the photovoltaic thermal module and the external power supply are used to charge the TREC battery cell at low voltage constant current. The entropy increase reaction occurs inside the battery and it continuously absorbs heat from the heat exchange medium. A3: Cut off the input of heat exchange medium, so that the TREC battery cell can exchange heat with the external environment, so that the temperature of the TREC battery cell drops to the preset low temperature value, and the open circuit voltage increases accordingly. A4: At low temperatures, the TREC battery cell undergoes high-voltage discharge through the external circuit. An entropy reduction reaction occurs inside the TREC battery cell, releasing heat to the environment. Since the discharge voltage is higher than the charging voltage, the electrical energy output by the system is greater than the electrical energy consumed during the charging phase, thus outputting net electrical work to complete one power generation cycle. Repeating the above cycle achieves continuous efficiency-enhancing power generation.

[0025] Repeating the above four steps can achieve enhanced power generation. The positive electrode storage tank 304 and the negative electrode storage tank 305 play a key role in heat buffering and electrolyte regulation in the system. When solar irradiance is sufficient and the heat generated by PV / T module 2 is greater than the real-time heat consumption of TREC module 3 in a single cycle, the intelligent control unit 1 adjusts the valve opening and pumping power in real time to allow some of the high-temperature electrolyte that has absorbed heat to flow back and be stored in the two storage tanks, thereby maximizing the utilization of the system's thermal energy. When the system enters the cooling stage or the heat input of PV / T module 2 is temporarily reduced, the high-temperature electrolyte stored in the storage tanks can be pumped back to the TREC battery unit to continue to provide the heat required to maintain the high temperature, thereby effectively extending the high-temperature maintenance range of each power generation cycle and significantly improving the overall power generation of the system.

[0026] Please see Figure 4 Example 2: TREC Electric Drive Active Cooling Mode The TREC electric-driven active cooling mode is suitable for situations where there is cooling demand on the user side and sufficient photovoltaic power generation during the high-temperature period in summer. Both branches of the second three-way valve 208 are closed, and the heat energy generated by the PV / T module 2 does not participate in the heat exchange in this mode. The system only uses photovoltaic power to drive the TREC battery unit to output cooling capacity to the user side. The intelligent control unit 1 uses part of the DC power generated by the PV / T module 2 as input power. When the photovoltaic-thermal combined cooling, heating and power system is in TREC electric-driven active cooling mode, the intelligent control unit 1 uses the electrical energy generated by the PV / T module 2 to drive the TREC module 3 to run in reverse and execute a cooling cycle based on the Brayton cycle. The cooling cycle includes the following steps: B1: Using the electrical energy generated by the photovoltaic effect of PV / T module 2, the TREC battery cell is driven to perform constant current charging in an isentropic state. An entropy-increasing electrochemical reaction occurs inside the TREC battery cell, causing the temperature of the TREC battery cell to continuously decrease until charging is complete. The TREC battery cell reaches the preset temperature, which is much lower than the target cooling space temperature. B2: After charging is complete, the charging circuit is cut off. The TREC battery cell does not undergo electrochemical reaction. Since the battery temperature is much lower than the target cooling space temperature, the TREC battery cell achieves cooling through heat exchange with the environment. B3: When the TREC battery cell is at the same temperature as the target cooling space, the TREC battery cell discharges through the external circuit. The TREC battery cell undergoes an entropy reduction reaction, causing the TREC battery cell temperature to rise continuously until the discharge is complete. The TREC battery cell then reaches the preset temperature, and the battery temperature is much higher than the external high temperature environment temperature. B4: After discharge is complete, the discharge circuit is cut off. The TREC battery cell cools down by releasing heat to the external environment and returns to the preset low temperature state, ready to enter the next cycle. The above cycle is repeated to achieve continuous active cooling.

[0027] By repeating the above four steps, active cooling can be achieved. Because an aqueous electrolyte is used, the working fluid has GWP=0 and ODP=0, which eliminates the greenhouse effect risk caused by leakage of traditional refrigerants from the root.

[0028] Please see Figure 5 Example 3: TREC Combined Cooling, Heating and Power Mode The TREC combined cooling, heating, and power (CCHP) mode is suitable for situations where users simultaneously have electricity, heating, and cooling needs, and where solar irradiance is sufficient and the system has adequate energy input. Electricity generation comes from two sources: direct power generation from the photovoltaic cell layer 203 and thermally driven enhanced power generation from the TREC module 3. The photovoltaic cell layer 203 of the PV / T module 2 absorbs visible to near-infrared wavelengths of solar irradiance, directly generating direct current through the photovoltaic effect. Part of this electrical energy is directly connected to the grid or used by external loads via the intelligent control unit. Simultaneously, the heat exchange medium in the heat exchange channel 205 absorbs unused solar spectrum from the photovoltaic cell layer 203 and heat generated by the cell's operation as it flows through the absorber plate 204, causing its temperature to rise and output low-grade thermal energy. At this time, the intelligent control unit 1 precisely adjusts the valve core opening of the second three-way valve 208 by outputting a control signal, allowing a portion of the high-temperature heat exchange medium to enter the external flow channel 306 of the TREC battery cell configured for power generation through the second branch under pump drive. This drives the TREC module 3 to convert the low-grade thermal energy into additional electrical energy according to a thermodynamic cycle. The outlet of the third three-way valve 307 corresponding to the TREC battery unit is switched to the side of the first three-way valve 207, forming a closed thermal circulation loop to maintain continuous power generation. This incremental power is superimposed with the photovoltaic DC power to jointly constitute the total power output of the system.

[0029] The heat energy is generated by the heat collection function of PV / T module 2. The second three-way valve 208 guides another part of the high-temperature heat exchange medium through the first branch to the heating circuit of the external heat-using terminal. Driven by the circulating water pump, the heat is transferred to the external heat-using terminal. The heat exchange medium is delivered to the user end, where it releases heat and cools down before flowing back to the PV / T module 2 via the first three-way valve 207 to absorb heat again, forming a closed loop.

[0030] The cooling capacity is generated by TREC electric-driven active cooling. The intelligent control unit 1 uses a portion of the electricity directly generated by photovoltaics to drive the TREC battery cells configured in cooling mode to perform a reverse Brayton cycle. At this time, the intelligent control unit 1 controls the third three-way valve 307 corresponding to the TREC battery cell to switch its outlet to the heat exchange circuit side of the target cooling space and starts the refrigerant circulation pump to connect the external flow channel 306 of the TREC battery cell to the target cooling space. The heat exchange working fluid circulates in the pipe, continuously transporting the heat from the user side to the battery side, thereby achieving active cooling. When the system needs to output cooling and electricity at the same time, the liquid storage tank can buffer the temperature fluctuation of the working fluid caused by the mode switching to ensure a smooth transition of TREC module 3 during the alternating operation of power generation and cooling. The capacity design of the storage tank needs to take into account both the heat collection rate of the PV / T module 2 and the heat dissipation rate of the TREC module. In this embodiment, a design with one independent storage tank for each positive and negative electrode is adopted. The intelligent control unit 1 can precisely adjust the electrolyte temperature and dynamic flow rate injected into the positive and negative electrode cavities by coordinating the control of the flow valves and liquid supply pumps on each individual pipeline, thereby further optimizing the overall electrochemical reaction efficiency of the system.

[0031] In this embodiment, the TREC module 3 may include one or more TREC battery units. When multiple units are configured, the intelligent control unit 1 can divide them into two groups according to real-time needs, and configure the second branch opening of the second three-way valve 208 and the switching state of the third three-way valve 307 for each group, so that the two groups of units operate in power generation mode and cooling mode respectively, realizing combined cooling and power supply. The first group operates in heat-driven power generation mode, using low-grade heat energy to generate additional electrical energy; the second group operates in electric-driven cooling mode, using photovoltaic power to generate cooling. The two groups of units operate independently and do not interfere with each other. The intelligent control unit 1 can automatically determine whether to enter the combined cooling, heating and power supply mode according to the real-time monitored solar irradiance intensity, heat storage temperature, power load and cooling demand signals, and regulate the three energy production paths to work in parallel and cooperate with each other.

[0032] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

Claims

1. A photovoltaic combined heat and power system integrating thermal regeneration electrochemical cycle, comprising an intelligent control unit (1), a PV / T module (2), and a TREC module (3), characterized in that: The PV / T module (2) is a multi-layer composite structure, including a glass cover plate (201), an air gap (202), a photovoltaic cell layer (203), a heat absorption plate (204), a heat exchange channel (205), and a heat insulation layer (206) arranged from top to bottom. The TREC module (3) and the PV / T module (2) are connected by a thermo-electric dual-path coupling through a heat exchange channel (205) and circuit lines, and operate in either a power generation mode or a cooling mode based on the thermo-electrochemical reaction principle. The TREC module (3) includes at least one TREC battery cell, a positive electrode storage tank (304), a negative electrode storage tank (305), and an external flow channel (306). The intelligent control unit (1) is connected to the PV / T module (2) and the TREC module (3) by electrical signal connection and power circuit connection respectively. The intelligent control unit (1) regulates the flow rate of the fluid pump group and the charging and discharging direction of the TREC battery group according to real-time meteorological data, system operating parameters and preset control strategies, and realizes flexible adaptive switching of the photovoltaic solar thermal combined cooling and power system between power generation efficiency enhancement mode, electrochemical cooling mode and combined cooling and power mode.

2. The photovoltaic-thermal combined cooling, heating and power system with integrated thermal regeneration electrochemical cycle according to claim 1, characterized in that: The photovoltaic cell layer (203) is mainly used to absorb the visible-near infrared band of solar radiation and realize photoelectric conversion. The heat-absorbing plate (204) is used to conduct heat collection of the mid-far infrared radiation that is not utilized by photovoltaics and the heat generated during the operation of the photovoltaic cell layer (203). The heat exchange channel (205) is provided with a continuously flowing heat exchange medium inside. The heat exchange channel (205) continuously carries away the heat collected by the heat-absorbing plate (204) through the heat exchange medium and forms a low-grade heat energy output. The glass cover (201) is low-iron, high-transparency tempered glass, the air gap (202) is an air insulation layer with a thickness of 15mm, the photovoltaic cell layer (203) is a high-conversion-rate crystalline silicon cell, the heat-absorbing plate (204) is a copper plate with a selective absorption coating on its surface, and the heat insulation layer (206) is polyurethane foam.

3. The photovoltaic-thermal combined cooling, heating and power system with integrated thermal regeneration electrochemical cycle according to claim 2, characterized in that: A first three-way valve (207) is fixedly installed at the inlet end of the heat exchange channel (205). The first three-way valve (207) is used to switch the source of the working fluid entering the heat exchange channel (205). A second three-way valve (208) is fixedly installed at the outlet end of the heat exchange channel (205). The inner side of the second three-way valve (208) is provided with a main road, a first branch road and a second branch road respectively. The main road is connected to the outlet of the heat exchange channel (205). The first branch road is used to connect to the external heat terminal. The second branch road is connected to the inlet of the external flow channel (306). The valve core opening of the second three-way valve (208) is adjusted by the intelligent control unit (1) according to the operating mode and realizes the on-demand directional distribution of heat.

4. The photovoltaic-thermal combined cooling, heating and power system with integrated thermal regeneration electrochemical cycle according to claim 3, characterized in that: Both the heat exchange channel (205) and the external channel (306) are serpentine microchannel tubes. The external channel (306) is attached to the outer wall of the TREC battery cell. The inlet end of the external channel (306) is connected to the second branch and receives the high-temperature heat exchange medium from the PV / T module (2). The outlet end of the external channel (306) is fixedly installed with a third three-way valve (307). The third three-way valve (307) is provided with a first inlet and a second inlet. The first inlet of the third three-way valve (307) is connected to the outlet end of the external channel (306). The second inlet of the third three-way valve (307) is connected to an external cooling circulating water circuit. The outlet end of the third three-way valve (307) is connected to the first three-way valve (207).

5. A photovoltaic combined heat and power system with integrated thermal regeneration electrochemical cycle according to claim 4, characterized in that: The TREC battery cell includes a positive electrode (301), a negative electrode (302), an ion exchange membrane (303), a positive electrolyte, and a negative electrolyte. The ion exchange membrane (303) is disposed between the positive electrode (301) and the negative electrode (302). The positive electrolyte and the negative electrolyte are respectively filled in the closed cavity between the positive electrode (301) and the ion exchange membrane (303) and between the negative electrode (302) and the ion exchange membrane (303). The positive electrolyte and the negative electrolyte are water-based solutions containing active substances required for electrochemical reactions. The ion exchange membrane (303) allows active ions to pass through in a directional manner.

6. A photovoltaic combined heat and power system with integrated thermal regeneration electrochemical cycle according to claim 5, characterized in that: The positive electrode storage tank (304) and the negative electrode storage tank (305) are respectively connected to the positive electrode side flow channel and the negative electrode side flow channel of the TREC battery cell through pipelines. The positive electrode storage tank (304) and the negative electrode storage tank (305) are used to store and circulate electrolyte, and also have the functions of working fluid buffer, thermal energy storage and flow regulation. Temperature sensors and liquid level sensors are installed inside the positive electrode storage tank (304) and the negative electrode storage tank (305). The intelligent control unit (1) monitors the thermal state and liquid volume changes of the working fluid in real time through the temperature sensor and the liquid level sensor.

7. A photovoltaic combined heat and power system with integrated thermal regeneration electrochemical cycle according to claim 6, characterized in that: The volume of the positive electrode storage tank (304) and the negative electrode storage tank (305) is determined by the scale of the photovoltaic combined heat and power system. The heat collection area of ​​the positive electrode storage tank (304) and the negative electrode storage tank (305) is adapted to the heat generation rate of the PV / T module (2) and the heat dissipation rate of the TREC module (3).

8. A photovoltaic combined heat and power system with integrated thermal regeneration electrochemical cycle according to claim 7, characterized in that: The hardware structure layer of the intelligent control unit (1) consists of a microprocessor, a memory and a multi-channel I / O interface. The microprocessor is either an industrial-grade microcontroller or a programmable logic controller. The memory is used to pre-store control programs and historical operating strategies. The system operating parameters include, but are not limited to, the temperature of the hot water storage tank, the temperature of the photovoltaic cell and the building's terminal heating and cooling load requirements.

9. A method for operating a photovoltaic-thermal-cooling-power (PV-CHP) system with an integrated thermal regenerative electrochemical cycle, as described in claim 8, characterized in that... The TREC includes a thermally driven efficiency-enhancing power generation mode, a TREC electrically driven active cooling mode, and a TREC combined cooling, heating, and power (CCHP) mode. The TREC thermally driven efficiency-enhancing power generation mode is a power generation efficiency-enhancing mode, the TREC electrically driven active cooling mode is an electrochemical cooling mode, and the TREC CCHP mode is a combined cooling, heating, and power (CCHP) mode. The activation condition for the TREC thermally driven efficiency-enhancing power generation mode is that the electricity demand exceeds the energy supply threshold. The activation condition for the TREC electrically driven active cooling mode is that the cooling demand exceeds a set threshold and photovoltaic power generation is sufficient. The activation condition for the TREC CCHP mode is that the user side has simultaneous electricity, heating, and cooling demands and sufficient irradiance. When the photovoltaic-thermal combined cooling, heating and power system is in TREC combined cooling, heating and power mode, the intelligent control unit (1) coordinates and controls the PV / T module (2) and the TREC module (3) and operates them simultaneously. The PV / T module (2) receives solar radiation to generate DC power, which is supplied to the power grid and external loads for use and to drive the TREC battery unit configured in cooling mode for reverse cooling. The heat exchange medium in the heat exchange channel (205) absorbs low-temperature heat energy through the heat absorption plate (204) and is distributed by the intelligent control unit (1). The low-temperature heat energy is divided into two groups. One group of the low-temperature heat energy is directly delivered to the external heat terminal to achieve heat energy supply. The other group of the low-temperature heat energy flows to the TREC battery unit configured in power generation mode and drives the TREC battery unit to perform thermodynamic positive cycle to output additional electrical energy. When the photovoltaic-thermal combined cooling, heating and power system is in TREC combined cooling, heating and power mode, it can output electrical energy, heat energy and cooling energy simultaneously through independent control of the TREC battery unit groups, and realize the comprehensive utilization of solar energy.

10. The operation method of a photovoltaic combined heat and power system with integrated thermal regeneration electrochemical cycle according to claim 9, characterized in that: When the photovoltaic combined solar power system is in TREC heat-driven efficiency-enhancing power generation mode, the heat exchange medium flows sequentially through the heat absorber plate (204) and the heat exchange channel (205) to absorb and heat up low-grade heat energy and heat the TREC battery cells, thereby driving the TREC battery cells to perform a power generation cycle. The power generation cycle includes the following steps: A1: The heat exchange medium carrying low-grade heat energy heats the TREC battery cell, raising its temperature to a preset high temperature value. Since the selected TREC battery cell has a negative temperature coefficient, its open circuit voltage decreases accordingly. A2: Under high temperature conditions, the power generated by the photovoltaic thermal module and the external power supply are used to charge the TREC battery cell at low voltage constant current. The entropy increase reaction occurs inside the battery and it continuously absorbs heat from the heat exchange medium. A3: Cut off the input of heat exchange medium, so that the TREC battery cell can exchange heat with the external environment, so that the temperature of the TREC battery cell drops to the preset low temperature value, and the open circuit voltage increases accordingly. A4: At low temperatures, the TREC battery cell undergoes high-voltage discharge through the external circuit. An entropy reduction reaction occurs inside the TREC battery cell, releasing heat to the environment. Since the discharge voltage is higher than the charging voltage, the electrical energy output by the system is greater than the electrical energy consumed during the charging phase, thus outputting net electrical work to complete one power generation cycle. Repeating the above cycle achieves continuous efficiency-enhancing power generation. When the photovoltaic combined solar power system is in TREC electric-driven active cooling mode, the intelligent control unit (1) uses the electrical energy generated by the PV / T module (2) to drive the TREC module (3) to run in reverse and execute a cooling cycle based on the Brayton cycle. The cooling cycle includes the following steps: B1: Using the power generated by the photovoltaic effect of the PV / T module (2), the TREC battery cell is driven to perform constant current charging in an isentropic state. An entropy-increasing electrochemical reaction occurs inside the TREC battery cell, causing the temperature of the TREC battery cell to continuously decrease until the charging is completed. The TREC battery cell reaches the preset temperature, and the temperature is much lower than the target cooling space temperature. B2: After charging is complete, the charging circuit is cut off. The TREC battery cell does not undergo electrochemical reaction. Since the battery temperature is much lower than the target cooling space temperature, the TREC battery cell achieves cooling through heat exchange with the environment. B3: When the TREC battery cell is at the same temperature as the target cooling space, the TREC battery cell discharges through the external circuit. The TREC battery cell undergoes an entropy reduction reaction, causing the TREC battery cell temperature to rise continuously until the discharge is complete. The TREC battery cell then reaches the preset temperature, and the battery temperature is much higher than the external high temperature environment temperature. B4: After discharge is complete, the discharge circuit is cut off. The TREC battery cell cools down by releasing heat to the external environment and returns to the preset low temperature state, ready to enter the next cycle. The above cycle is repeated to achieve continuous active cooling.

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