Photovoltaic photo-thermal system

Abstract

The invention discloses a photovoltaic and photo-thermal system. The system comprises a photovoltaic module, a refrigerant circulating system, a detection part and a controller, the refrigerant circulation system comprises a first heat exchanger, a second heat exchanger, a third heat exchanger, a first control valve and a second control valve, the first heat exchanger is connected with the second heat exchanger through the first control valve to form a first circulation loop, and the first heat exchanger is connected with the third heat exchanger through the second control valve to form a second circulation loop; the third heat exchanger exchanges heat with the photovoltaic module; the detection component is used for outputting detection parameters; the controller is connected with the detection component and used for controlling the opening degree of the first control valve and the second control valve based on the detection parameters. Through the mode, the working temperature of the photovoltaic module can be reduced, so that the utilization rate of solar energy is improved, and flexible configuration of the heat exchange amount of each heat exchanger in the system can be realized.

Description

Technical Field

[0001] The present application relates to the field of thermal management technology, and in particular to a photovoltaic thermal system. Background Art

[0002] As the most accessible and widely distributed renewable energy, solar energy has attracted more and more attention. With the innovation of materials and technologies, the technology of using photovoltaic modules to generate electricity has gradually emerged. However, the operating temperature of photovoltaic modules increases and the power generation efficiency decreases, resulting in low solar energy utilization. The power generation efficiency of photovoltaic modules is generally around 20%, and the remaining 80% of the energy is dissipated in the environment in the form of waste heat, which will also cause the operating temperature of photovoltaic modules to increase and waste resources. Summary of the invention

[0003] The main technical problem solved by the present application is to provide a photovoltaic thermal system that can reduce the operating temperature of photovoltaic components to improve the utilization rate of solar energy and realize flexible configuration of the heat exchange capacity of each heat exchanger in the system.

[0004] To solve the above technical problems, the present application provides a photovoltaic thermal system, which includes a photovoltaic component, a refrigerant circulation system, a detection component and a controller; the refrigerant circulation system includes a first heat exchanger, a second heat exchanger, a third heat exchanger, a first control valve and a second control valve, the first heat exchanger is connected to the second heat exchanger via the first control valve to form a first circulation loop, the first heat exchanger is connected to the third heat exchanger via the second control valve to form a second circulation loop, and the third heat exchanger performs heat exchange with the photovoltaic component; the detection component is used to output detection parameters; the controller is connected to the detection component, and is used to control the opening of the first control valve and the second control valve based on the detection parameters.

[0005] The detection parameter is at least partially used to characterize the light intensity, and the controller is used to control the opening of the first control valve and the second control valve based on the light intensity characterized by the detection parameter.

[0006] The detection component includes a first temperature sensor disposed between the first input end of the third heat exchanger and the photovoltaic assembly. The first temperature sensor is used to detect a first temperature of the heat exchange medium flowing into the first input end of the third heat exchanger. The first temperature is used to characterize light intensity.

[0007] The detection component also includes a power generation detection component for detecting the power generation of the photovoltaic module, and the power generation is used to characterize the light intensity.

[0008] Among them, the detection component includes a first temperature sensor arranged between the first input end of the third heat exchanger and the photovoltaic component, and a power generation detection component for detecting the power generation of the photovoltaic component; the first temperature sensor is used to detect the first temperature of the heat exchange medium flowing into the first input end of the third heat exchanger; the controller is used to calculate the light intensity based on the first temperature and the power generation.

[0009] Among them, the detection component also includes a second temperature sensor arranged between the first output end of the third heat exchanger and the photovoltaic component, and the second temperature sensor is used to detect the second temperature of the heat exchange medium flowing out of the second output end of the third heat exchanger; the controller is used to calculate the light intensity based on the first temperature, the second temperature and the power generation.

[0010] The controller is used to control the opening of the second control valve based on the target heat exchange amount of the third heat exchanger, and to control the opening of the first control valve based on the opening of the second control valve; wherein the target heat exchange amount is determined by light intensity.

[0011] The controller is used to determine the target heat exchange capacity of the third heat exchanger based on the light intensity and the heat load of the first heat exchanger.

[0012] Among them, the controller controls the opening of the second control valve so that the actual heat exchange rate of the third heat exchanger approaches the target heat exchange rate; the detection component includes a first temperature sensor arranged between the first input end of the third heat exchanger and the photovoltaic component, and a second temperature sensor arranged between the first output end of the third heat exchanger and the photovoltaic component. The temperature difference between the outputs of the first temperature sensor and the second temperature sensor is used to characterize the actual heat exchange rate.

[0013] The controller controls the opening of the second control valve so that the actual heat exchange of the third heat exchanger approaches the target heat exchange, including: in response to the target heat exchange being greater than the actual heat exchange, increasing the opening of the second control valve; and / or, in response to the target heat exchange being less than the actual heat exchange, reducing the opening of the second control valve.

[0014] The controller is used to increase or decrease the opening of the first control valve based on the opening of the second control valve and the subcooling degree of the second heat exchanger.

[0015] In which, the photovoltaic thermal system is provided with a first light intensity threshold and a second light intensity threshold, and the controller is configured to switch to a first heating mode in response to the light intensity being not less than the first light intensity threshold, wherein the first control valve is closed and the second control valve is opened; the controller is configured to switch to a second heating mode in response to the light intensity being less than the second light intensity threshold, wherein the first control valve is opened and the second control valve is closed; the controller is configured to switch to a third heating mode in response to the light intensity being between the first light intensity threshold and the second light intensity threshold, wherein both the first control valve and the second control valve are opened; wherein the first light intensity threshold is greater than the second light intensity threshold.

[0016] Wherein, the controller is configured to adjust the first light intensity threshold and / or the second light intensity threshold based on the heat load of the first heat exchanger.

[0017] Among them, the input end of the second heat exchanger is connected to the output end of the first heat exchanger through the first control valve, and the output end of the second heat exchanger is connected to the input end of the first heat exchanger; the second input end of the third heat exchanger is connected to the output end of the first heat exchanger through the second control valve, and the second output end of the third heat exchanger is connected to the input end of the first heat exchanger.

[0018] Among them, the refrigerant circulation system also includes a compressor, and the output end of the second heat exchanger and the second output end of the third heat exchanger are both connected to the input end of the first heat exchanger through the compressor, wherein the connection between the compressor and at least two of the first heat exchanger, the second heat exchanger and the third heat exchanger is achieved by using a multi-way valve.

[0019] At least one of the first control valve and the second control valve is any one of an expansion valve, a throttle valve, and a capillary tube.

[0020] Among them, the photovoltaic thermal system also includes at least one of the following: a photovoltaic side pump body, a heat storage device, and an electric energy conversion circuit. The photovoltaic side pump body is arranged between the photovoltaic component and the third heat exchanger, and is used to drive the flow of the heat exchange medium between the photovoltaic component and the third heat exchanger; the heat storage device is arranged between the photovoltaic component and the third heat exchanger; the electric energy conversion circuit is electrically connected to the photovoltaic component and the controller, and is used to convert the electric energy output by the photovoltaic component into alternating current.

[0021] Wherein, the photovoltaic module also includes a collector; or, the third heat exchanger is a fluorine cold plate collector.

[0022] Among them, the second heat exchanger is an air source heat exchanger using air as a heat source.

[0023] Among them, the third heat exchanger is a medium source heat exchanger using a heat exchange medium as a heat source.

[0024] There are multiple groups of second heat exchangers and first control valves; the first heat exchanger is connected to the second heat exchanger in the same group through the first control valve of each group to form multiple groups of first circulation loops; or, there are multiple second heat exchangers, which are connected in series with each other, and the first heat exchanger is connected to the series sequence formed by the first control valve and multiple second heat exchangers.

[0025] The beneficial effect of the present application is that, different from the prior art, the third heat exchanger in the photovoltaic thermal system provided by the present application performs heat exchange with the photovoltaic module to utilize the heat generated by the photovoltaic module, which can reduce the temperature of the photovoltaic module and increase the power generation of the photovoltaic module, thereby improving the utilization rate of solar energy. Furthermore, by setting a detection component, according to the detection parameters of the detection component, the opening of the first control valve and the second control valve is controlled, and then the amount of refrigerant entering the second heat exchanger and the third heat exchanger is controlled, so as to realize the flexible distribution of the heat exchange amount of each heat exchanger. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a structural schematic diagram of an implementation scheme of a photovoltaic thermal system provided by the present application;

[0027] Figure 2 It is a structural schematic diagram of another embodiment of the photovoltaic thermal system provided by the present application;

[0028] Figure 3 is a schematic diagram of an implementation method of connecting the compressor 27 with the third heat exchanger 23 and the second heat exchanger 22;

[0029] Figure 4 is a schematic diagram of another embodiment of the connection method of the compressor 27 with the third heat exchanger 23 and the second heat exchanger 22;

[0030] Figure 5 It is a flow chart of an implementation method of a photovoltaic thermal system control method provided by the present application;

[0031] Figure 6 It is a schematic diagram of the framework structure of an embodiment of an electronic device provided by the present application;

[0032] Figure 7 It is a schematic diagram of the framework structure of an implementation scheme of a computer-readable storage medium provided in this application. DETAILED DESCRIPTION

[0033] The following is a clear and complete description of the technical solutions in the embodiments of the present application in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0034] It should be noted that in the embodiments of the present application, there are descriptions involving "first", "second", etc., which are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" or "second" may explicitly or implicitly include at least one of the features.

[0035] In the description of the application, the meaning of "multiple" is at least two, for example, two, three, etc., unless otherwise clearly and specifically limited. In the embodiment of the present application, all directional indications (such as up, down, left, right, front, back ...) are only used to explain the relative position relationship, movement, etc. between the components under a certain specific posture (as shown in the drawings). If the specific posture changes, the directional indication also changes accordingly. In addition, the terms "including" and "having" and any of their deformations are intended to cover non-exclusive inclusions. For example, the process, method, system, product or equipment comprising a series of steps or units is not limited to the steps or units listed, but optionally also includes the steps or units not listed, or optionally also includes other steps or units inherent to these processes, methods, products or equipment.

[0036] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present invention. The appearance of the phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0037] See also Figure 1 , Figure 1 It is a structural schematic diagram of an embodiment of a photovoltaic thermal system provided in this application.

[0038] In one embodiment, the photovoltaic thermal system 100 includes a photovoltaic component 1, a refrigerant circulation system 2, a detection component 3 and a controller 4. The photovoltaic component 1 can also be called a PVT component, and the photovoltaic component 1 can generate electricity using solar energy. Specifically, the photovoltaic component 1 may include a collector, which collects heat from the photovoltaic component 1, and a heat exchange medium can flow in the collector to absorb the heat of the photovoltaic component 1. The collector can be a flat plate heat exchanger, which contacts the back of a traditional photovoltaic panel through a certain processing method, such as welding, and a heat exchange medium flows in the flat plate heat exchanger. The collector collects the heat generated by the photovoltaic panel through the flowing heat exchange medium. In a specific embodiment, the flat plate heat exchanger may include a water-cooled plate, which contains a pipeline, and the heat exchange medium can flow in the pipeline to absorb the heat of the photovoltaic panel.

[0039] The refrigerant circulation system 2 includes a first heat exchanger 21, a second heat exchanger 22, a third heat exchanger 23, a first control valve 24 and a second control valve 25. The first heat exchanger 21 is connected to the second heat exchanger 22 via the first control valve 24 to form a first circulation loop. The first heat exchanger 21 is connected to the third heat exchanger 23 via the second control valve 25 to form a second circulation loop. The third heat exchanger 23 performs heat exchange with the photovoltaic module 1. Specifically, the input end of the second heat exchanger 22 is connected to the output end of the first heat exchanger 21 via the first control valve 24, and the output end of the second heat exchanger 22 is connected to the input end of the first heat exchanger 21; the second input end of the third heat exchanger 23 is connected to the output end of the first heat exchanger 21 via the second control valve 25, and the second output end of the third heat exchanger 23 is connected to the input end of the first heat exchanger 21. The first input end and the first output end of the third heat exchanger 23 are connected to the photovoltaic module 1.

[0040] Through the first circulation loop, the second heat exchanger 22 can transfer the heat of a heat source to the first heat exchanger 21, and the heat source can be an air source, a water source, a ground source, etc.; through the second circulation loop, the third heat exchanger 23 can transfer the heat of the photovoltaic module 1 to the first heat exchanger 21, and the first heat exchanger 21 can transfer the received heat to the user object that needs heat. The heat of the photovoltaic module 1 can be transferred to the third heat exchanger 23 through the heat exchange medium, and the heat exchange medium can circulate between the photovoltaic module 1 and the third heat exchanger 23 to achieve heat transfer.

[0041] In a specific embodiment, the second heat exchanger 22 can be an air source heat exchanger with air as a heat source, and the third heat exchanger 23 can be a medium source heat exchanger with a heat exchange medium as a heat source. The heat exchange medium can be at least one of water, liquid sodium, heat transfer liquid, ethylene glycol, etc. In a specific embodiment, the heat exchange medium is a mixture of water and ethylene glycol. It can be understood that the photovoltaic thermal system 100 can include one or more second heat exchangers 22, and multiple second heat exchangers 22 can use the same or different heat sources; if the photovoltaic thermal system 100 includes multiple second heat exchangers 22, the multiple second heat exchangers 22 can be connected in parallel or in series.

[0042] In one embodiment, a plurality of second heat exchangers 22 are connected in parallel. Specifically, the number of second heat exchangers 22 and first control valves 24 is a plurality of groups, each group includes a second heat exchanger 22 and a first control valve 24, and the first heat exchanger 21 is connected to the second heat exchangers 22 in the same group through the first control valve 24 of each group, respectively, to form a plurality of first circulation loops, and the first control valve 24 of each group can control the amount of refrigerant entering the second heat exchanger 22 in the same group. It can be understood that in each group of first circulation loops, the input end of the second heat exchanger 22 is connected to the output end of the first heat exchanger 21 through the first control valve 24, and the output end of the second heat exchanger 22 is connected to the input end of the first heat exchanger 21.

[0043] In another embodiment, a plurality of second heat exchangers 22 are connected in series, and the first heat exchanger 21 is connected to the series sequence formed by the plurality of second heat exchangers 22 through a first control valve 24. Specifically, the input end of a second heat exchanger 22 located at one end of the series sequence among the plurality of second heat exchangers 22 is connected to the output end of the first heat exchanger 21 through the first control valve 24, and the output end of another second heat exchanger 22 located at one end of the series sequence among the plurality of second heat exchangers 22 is connected to the input end of the first heat exchanger 21. The first control valve 24 and the second control valve 25 can both be any one of an expansion valve, a throttle valve, a capillary tube, and a stop valve. It can be understood that the first control valve 24 and the second control valve 25 can be the same or different, for example, both are expansion valves, or one of the first control valve 24 and the second control valve 25 is an expansion valve and the other is a throttle valve.

[0044] The detection component 3 is used to output detection parameters, and the detection parameters can characterize at least one of light intensity and heat. In one embodiment, some of the detection parameters can characterize light intensity. Correspondingly, the detection component 3 includes a light intensity detection component for detecting parameters characterizing light intensity, and the light intensity detection component includes but is not limited to a photometer, a light meter, a temperature sensor, a power generation detection component, etc. The power generation detection component includes but is not limited to a generator set test equipment, a generator test bench, a power generation tester, etc.

[0045] In a specific embodiment, the detection component 3 includes a first temperature sensor 31, which can be arranged between the first input end of the third heat exchanger 23 and the photovoltaic component 1. The first temperature sensor 31 is used to detect the first temperature of the heat exchange medium flowing into the first input end of the third heat exchanger 23. The first temperature can be used to characterize the light intensity.

[0046] In another specific embodiment, the detection component 3 includes a power generation detection component for detecting the power generation of the photovoltaic component 1, and the power generation can be used to characterize the light intensity. The power generation detection component can be connected to the photovoltaic component 1 to determine the power generation of the photovoltaic component 1.

[0047] In other specific embodiments, the detection component 3 may include a first temperature sensor 31 and a power generation detection component. The controller 4 can calculate the light intensity according to the first temperature detected by the first temperature sensor 31 and the power generation detected by the power generation detection component.

[0048] The controller 4 is connected to the detection component 3, and is used to control the opening of the first control valve 24 and the second control valve 25 based on the detection parameters output by the detection component 3. The larger the opening of the first control valve 24, the greater the heat exchange capacity of the second heat exchanger 22; the larger the opening of the second control valve 25, the greater the heat exchange capacity of the third heat exchanger 23.

[0049] In one embodiment, the detection parameter is at least partially used to characterize the light intensity, and the controller 4 can control the opening of the first control valve 24 and the second control valve 25 based on the light intensity characterized by the detection parameter. When the light intensity increases, the more heat the photovoltaic assembly 1 generates, and the greater the heat exchange amount that the third heat exchanger 23 that performs heat exchange with the photovoltaic assembly 1 can exchange, so the opening of the second control valve 25 can be increased to increase the flow of the refrigerant passing through the second control valve 25 to increase the heat exchange amount of the third heat exchanger 23; conversely, if the light intensity decreases, the opening of the second control valve 25 can be reduced. The opening of the first control valve 24 can be adjusted based on the opening of the second control valve 25. For example, when the heat load of the first heat exchanger 21 is fixed, the opening of the second control valve 25 increases and the opening of the first control valve 24 decreases; conversely, the opening of the second control valve 25 decreases and the opening of the first control valve 24 increases. When the heat load of the first heat exchanger 21 changes, the opening of the second control valve 25 can be determined based on the light intensity to determine the actual heat exchange rate of the third heat exchanger 23, and then the target heat exchange rate of the second heat exchanger 22 can be determined based on the heat load of the first heat exchanger 21 and the actual heat exchange rate of the third heat exchanger 23. The opening of the first control valve 24 is adjusted according to the target heat exchange rate of the second heat exchanger 22.

[0050] Since the power generation efficiency decreases by 0.4% for every 1°C increase in the working temperature of the photovoltaic module 1; the power generation efficiency of the photovoltaic module 1 is generally about 20%, and the remaining 80% of the energy is dissipated in the environment in the form of waste heat, which will also cause the working temperature of the photovoltaic module 1 to increase and waste energy. The third heat exchanger 23 in the photovoltaic thermal system 100 provided in the above manner exchanges heat with the photovoltaic module 1 to utilize the heat generated by the photovoltaic module 1, which can reduce the temperature of the photovoltaic module 1 and increase the power generation of the photovoltaic module 1, thereby improving the utilization rate of solar energy. Further, by setting the detection component 3, according to the detection parameters of the detection component 3, the opening of the first control valve 24 and the second control valve 25 is controlled, and then the amount of refrigerant entering the second heat exchanger and the third heat exchanger is controlled, so as to realize the heat exchange of each heat exchanger set to flexible distribution. In one embodiment, it can be given priority to ensure that the heat exchange of the heat exchanger with better performance meets the requirements, so that the performance of the photovoltaic thermal system can be improved.

[0051] In one embodiment, the heat exchange capacity of the third heat exchanger 23 (heat of the photovoltaic module 1) can be prioritized, and the heat exchange capacity of the second heat exchanger 22 (heat of other heat sources) can be used as a supplement. For example, the controller 4 controls the opening of the first control valve 24 and the second control valve 25 based on the light intensity represented by the detection parameter, including: the controller 4 controls the opening of the second control valve 25 based on the target heat exchange capacity of the third heat exchanger 23, and then controls the opening of the first control valve 24 based on the opening of the second control valve 25.

[0052] Specifically, the controller 4 can obtain the target heat exchange amount of the third heat exchanger 23 based on the light intensity, and then control the opening of the second control valve 25 based on the target heat exchange amount, so that after adjusting the opening of the second control valve 25, the actual heat exchange amount of the third heat exchanger 23 approaches the target heat exchange amount. Among them, the target heat exchange amount of the third heat exchanger 23 is related to the light intensity, and a relationship formula or relationship table between the target heat exchange amount of the third heat exchanger 23 and the light intensity can be established in advance, and then the current target heat exchange amount of the third heat exchanger 23 is obtained according to the relationship between the two and the currently determined light intensity. In one embodiment, the greater the light intensity, the greater the target heat exchange amount.

[0053] In a specific embodiment, the target heat exchange amount of the third heat exchanger 23 is also related to the heat load of the first heat exchanger 21, and the controller 4 can determine the target heat exchange amount of the third heat exchanger 23 based on the light intensity and the heat load of the first heat exchanger. The greater the heat load, the greater the target heat exchange amount. Specifically, a relationship table of the target heat exchange amount of the third heat exchanger 23, the light intensity, and the heat load of the first heat exchanger 21 can be pre-set, and the controller 4 looks up the table to obtain the target heat exchange amount of the third heat exchanger 23.

[0054] When the opening of the second control valve 25 is determined, the opening of the first control valve 24 can be controlled based on the opening of the second control valve 25. When the opening of the second control valve 25 is determined, the actual heat exchange of the third heat exchanger 23 is determined, and the target heat exchange of the second heat exchanger 22 can be obtained according to the difference between the heat load of the first heat exchanger 21 and the actual heat exchange of the third heat exchanger 23, and the opening of the first control valve 24 can be adjusted according to the target heat exchange of the second heat exchanger 22.

[0055] In a specific embodiment, the opening of the first control valve 24 is also related to the subcooling degree of the second heat exchanger 22, and the controller 4 can increase or decrease the opening of the first control valve 24 based on the opening of the second control valve 25 and the subcooling degree of the second heat exchanger 22. For example, after the opening of the second control valve 25 is determined, in response to the current subcooling degree being greater than the target subcooling degree, the opening of the first control valve 24 is increased; in response to the current subcooling degree being less than the target subcooling degree, the opening of the first control valve 24 is reduced. Among them, the target subcooling degree can be preset, for example, a relationship table between the target heat exchange amount and the target subcooling degree of the second heat exchanger 22 can be set, and the target subcooling degree is obtained by looking up the table according to the target heat exchange amount of the second heat exchanger 22.

[0056] In the above embodiment, if the detection component 3 includes a first temperature sensor 31, the light intensity can be characterized by the first temperature detected by the first temperature sensor 31; if the detection component 3 includes a power generation detection component, the light intensity can be characterized by the power generation detected by the power generation detection component; if the detection component 3 includes a first temperature sensor 31 and a power generation detection component, the controller can calculate the light intensity based on the first temperature and the power generation. Specifically, the first temperature and the power generation can be substituted into the first light intensity function to obtain the light intensity; the first light intensity function can be fitted using a large amount of first temperature, power generation and light intensity data. For example, N groups of data can be obtained, each group of data includes a first temperature, a power generation and a light intensity, N is at least greater than 2, and the first light intensity function is fitted by the N groups of data using a data fitting method. Data fitting methods include but are not limited to polynomial fitting, least squares method, interpolation method, curve fitting, non-parametric fitting and Bayesian fitting.

[0057] Please continue reading Figure 1 In one embodiment, the detection component 3 includes, in addition to the first temperature sensor 31 and the power generation detection component, a second temperature sensor 32. The second temperature sensor 32 is arranged between the first output end of the third heat exchanger 23 and the photovoltaic component 1. The second temperature sensor 32 is used to detect the second temperature of the heat exchange medium flowing out of the second output end of the third heat exchanger 23.

[0058] The light intensity can be calculated based on the first temperature, the second temperature and the power generation. Specifically, the first temperature, the second temperature and the power generation are substituted into the second light intensity function to obtain the light intensity. The second light intensity function can be fitted using a large amount of first temperature, second temperature, power generation and light intensity data. For example, M groups of data can be obtained, each group of data includes a first temperature, a second temperature, a power generation and a light intensity, M is at least greater than 2, and the second light intensity function is fitted by using the M groups of data using a data fitting method. Similarly, the data fitting method includes but is not limited to polynomial fitting, least squares method, interpolation method, curve fitting, non-parametric fitting and Bayesian fitting.

[0059] The controller 4 controls the opening of the second control valve 25 based on the target heat exchange amount of the third heat exchanger 23, including: controlling the opening of the second control valve 25 so that the actual heat exchange amount of the third heat exchanger 23 approaches the target heat exchange amount. The actual heat exchange amount can be determined based on the difference between the first temperature and the second temperature. Specifically, in response to the target heat exchange amount being greater than the actual heat exchange amount, the opening of the second control valve 25 is increased; in response to the target heat exchange amount being less than the actual heat exchange amount, the opening of the second control valve 25 is decreased.

[0060] In a specific embodiment, the target heat exchange amount and the actual heat exchange amount are both represented by the temperature difference between the first temperature and the second temperature. According to the first current temperature output by the first temperature sensor 31, the target temperature difference is obtained by looking up the preset table, and then the actual temperature difference between the first current temperature and the second current temperature output by the second temperature sensor 32 is obtained. In response to the target temperature difference being greater than the actual temperature difference, the opening of the second control valve 25 is increased; in response to the target temperature difference being less than the actual temperature difference, the opening of the second control valve 25 is reduced. In this embodiment, the preset table represents the relationship between the first temperature and the target temperature difference.

[0061] In other embodiments, the target temperature difference will also be affected by the heat load of the first heat exchanger 21. In this case, the preset table can characterize the relationship between the first temperature, the heat load of the first heat exchanger 21 and the target temperature difference. As shown in Table 1, Δt1 to Δt15 represent different target temperature differences, Q1 to Q4 represent different heat loads of the first heat exchanger 21, t1 to t7 represent different first temperatures, Δt1 to Δt15, Q1 to Q4, and t1 to t7 all increase in sequence. As the first temperature increases, the target temperature difference increases; as the heat load increases, the target temperature difference increases. It can be understood that each target temperature difference in Table 1 represents the temperature difference within a certain first temperature range or a certain heat load range. As shown in Table 1, when the heat load is Q1, when the first temperature difference is t1, t2 or t3, the target temperature difference is Δt1; similarly, when the first temperature is t1, when the heat load is Q1, Q2, Q3 or Q4, the target temperature difference is Δt1.

[0062] Table 1 Relationship between the first temperature, the heat load of the first heat exchanger 21 and the target temperature difference

[0063]

[0064] In one embodiment, the third heat exchanger 23 may be a medium source heat exchanger, and the second heat exchanger 22 may be an air source heat exchanger. The medium source heat exchanger is superior to the air source heat exchanger. By setting a target temperature difference and adjusting the opening of the second control valve 25 based on the target temperature difference and the actual temperature difference, the actual heat exchange amount of the third heat exchanger 23 can be made close to the target heat exchange amount, so as to give priority to the heat exchange amount of the third heat exchanger 23. Then, the opening of the first control valve 24 is adjusted to adjust the heat exchange amount of the second heat exchanger 22, so that the heat exchange amount of the third heat exchanger 23 and the heat exchange amount of the second heat exchanger 22 can comprehensively meet the heat load of the first heat exchanger 21. By distributing the heat exchange amount, the performance of the heat exchanger with better performance in the refrigerant circulation system is preferentially guaranteed to reach the best, so as to ensure the performance of the refrigerant circulation system to reach the best.

[0065] In one embodiment, the photovoltaic thermal system 100 is provided with a first light intensity threshold and a second light intensity threshold. The photovoltaic thermal system 100 is configured to include three working modes. The detection parameters are at least partially used to characterize the light intensity. The controller 4 is configured to switch to the first heating mode in response to the light intensity being not less than the first light intensity threshold. In the first heating mode, the first control valve 24 is closed and the second control valve 25 is opened; in response to the light intensity being less than the second light intensity threshold, the controller 4 is configured to switch to the second heating mode. In the second heating mode, the first control valve 24 is opened and the second control valve 25 is closed; the controller is configured to switch to the third heating mode in response to the light intensity being between the first light intensity threshold and the second light intensity threshold. In the third heating mode, both the first control valve 24 and the second control valve 25 are opened; wherein the first light intensity threshold is greater than the second light intensity threshold.

[0066] It can be understood that after obtaining the detection parameters, the controller 4 can first determine the working mode of the photovoltaic thermal system 100 according to the light intensity represented by the detection parameters, and enter the corresponding working mode by adjusting the switches of the first control valve 24 and the second control valve 25. If the photovoltaic thermal system 100 is controlled to be in the third working mode, the opening of the first control valve 24 and the second control valve 25 can be further controlled based on the light intensity represented by the detection parameters. Please refer to the above description for the determination method of the light intensity, which will not be repeated here.

[0067] Among them, the first illumination intensity threshold and / or the second illumination intensity threshold can be set as needed. In one embodiment, the first illumination intensity threshold and / or the second illumination intensity threshold can be adjusted based on the heat load of the first heat exchanger 21. The greater the heat load of the first heat exchanger 21, the greater the first illumination intensity and / or the second illumination intensity threshold. In a specific embodiment, as the heat load of the first heat exchanger 21 increases, both the first illumination intensity and the second illumination intensity threshold increase.

[0068] Please refer to Figure 1 and Figure 2 , Figure 2 It is a structural schematic diagram of another embodiment of the photovoltaic thermal system provided in the present application.

[0069] The refrigeration cycle system 2 may further include a compressor 27, and the output end of the second heat exchanger 22 and the second output end of the third heat exchanger 23 are both connected to the input end of the first heat exchanger 21 through the compressor 27, wherein the connection between the compressor 27 and at least two of the first heat exchanger 21, the second heat exchanger 22 and the third heat exchanger 23 is achieved by using a multi-way valve 26. The multi-way valve 26 may be a two-way valve, a three-way valve or a four-way valve, and in a specific embodiment, a four-way valve may be used. The compressor 27 can process the gaseous refrigerant flowing out of the second heat exchanger 22 or the third heat exchanger 23 into a high-temperature and high-pressure state, and transfer it to the first heat exchanger 21.

[0070] The connection mode of the compressor 27 with the second heat exchanger 22 and the third heat exchanger 23 includes: one of the second output end of the third heat exchanger 23 and the output end of the second heat exchanger 22 is connected to the air inlet of the compressor 27, and the other is connected to the air inlet of the compressor 27 through the first connection end pair of the multi-way valve 26, or the second output end of the third heat exchanger 23 and the output end of the second heat exchanger 22 are both connected to the air inlet of the compressor 27 through the first connection end pair. The connection mode of the compressor 27 with the first heat exchanger 21 includes: the air outlet of the compressor 27 is connected to the input end of the first heat exchanger 21 through the second connection end of the multi-way valve 26.

[0071] Please refer to Figure 2 and Figure 3 , Figure 3 It is a schematic diagram of an implementation manner of connecting the compressor 27 with the third heat exchanger 23 and the second heat exchanger 22 .

[0072] The second output end of the third heat exchanger 23 is directly connected to the air inlet of the compressor 27, and the output end of the second heat exchanger 22 is connected to the first port 261 of the multi-way valve 26, the first port 261 of the multi-way valve 26 and the second port 262 of the multi-way valve 26 are communicated, the first port 261 of the multi-way valve 26 and the second port 262 of the multi-way valve 26 form a first connection end pair, the second port 262 of the multi-way valve 26 is connected to the air inlet of the compressor 27, and the refrigerant output from the output end of the second heat exchanger 22 flows to the air inlet of the compressor 27 through the first port 261 of the multi-way valve 26 and the second port 262 of the multi-way valve 26. The third port 263 of the multi-way valve 26 is connected to the air outlet of the compressor 27, the third port 263 of the multi-way valve 26 is communicated with the fourth port 264, the third port 263 and the fourth port 264 form a second connection end pair, and the fourth port 264 is connected to the input end of the first heat exchanger 21; the refrigerant processed by the compressor 27 flows to the input end of the first heat exchanger 21 through the third port 263 and the fourth port 264 of the multi-way valve 26.

[0073] Please refer to Figure 2 and Figure 4 , Figure 4 It is a schematic diagram of another embodiment of the connection method of the compressor 27 with the third heat exchanger 23 and the second heat exchanger 22.

[0074] The second output end of the third heat exchanger 23 and the output end of the second heat exchanger 22 are both connected to the first port 261 of the multi-way valve 26, the first port 261 of the multi-way valve 26 and the second port 262 of the multi-way valve 26 are communicated, the first port 261 of the multi-way valve 26 and the second port 262 of the multi-way valve 26 form a first connection end pair, the second port 262 of the multi-way valve 26 is connected to the air inlet of the compressor 27, the refrigerant output from the second output end of the third heat exchanger 23 and the output end of the second heat exchanger 22 are mixed, and then flow to the air inlet of the compressor 27 through the first port 261 of the multi-way valve 26 and the second port 262 of the multi-way valve 26. The third port 263 of the multi-way valve 26 is connected to the air outlet of the compressor 27, the third port 263 of the multi-way valve 26 is connected to the fourth port 264, and the fourth port 264 is connected to the input end of the first heat exchanger 21; the refrigerant processed by the compressor 27 flows to the input end of the first heat exchanger 21 through the third port 263 and the fourth port 264 of the multi-way valve 26.

[0075] Please continue reading Figure 2In one embodiment, the photovoltaic thermal system 100 may further include at least one of a photovoltaic side pump body 5, a heat storage device (not shown in the figure), an electric energy conversion circuit 6, and a fan 28. The photovoltaic side pump body 5 is disposed between the photovoltaic module 1 and the third heat exchanger 23, and is used to drive the flow of the heat exchange medium between the photovoltaic module 1 and the third heat exchanger 23. In one embodiment, the photovoltaic side pump body 5 is disposed between the first output end of the third heat exchanger 23 and the photovoltaic module 1. The heat storage device is disposed between the photovoltaic module 1 and the third heat exchanger 23. In a specific embodiment, the heat storage device may be disposed between the photovoltaic module 1 and the first input end of the third heat exchanger 23. If the detection component 3 is a first temperature sensor 31, the heat storage device may be disposed between the photovoltaic module 1 and the first temperature sensor 31. When the second heat exchanger 22 is an air source heat exchanger, the photovoltaic thermal system 100 may further include a fan 28, and the fan 28 is used to drive the air flow. The power conversion circuit 6 is electrically connected to the photovoltaic module 1 and the controller 4, and is used to convert the power output by the photovoltaic module 1 into alternating current. The power conversion circuit 6 can be an inverter. If the detection component 3 includes a power generation detection component, the power generation detection component can be connected to the power conversion circuit 6 to measure the power.

[0076] In one embodiment, the photovoltaic thermal system 100 further includes a user-side pump body 7 and a user object 8, where the user object 8 is an object that uses heat. The first heat exchanger 21 can transfer the heat exchange of the third heat exchanger 23 and the second heat exchanger 22 to the user object 8, and the user-side pump body 7 is disposed between the first heat exchanger 21 and the user object 8 to drive the flow of the fluid between the first heat exchanger 21 and the user object 8.

[0077] In other embodiments, the third heat exchanger 23 in the above embodiment may also be a fluorine cold plate heat collector, which is used to collect heat from the photovoltaic module 1. In this case, there is no need to set up the third heat exchanger 23 and the heat collector. The flowing medium in the fluorine cold plate heat collector may be a refrigerant.

[0078] In a specific embodiment, Figure 2 As shown, the photovoltaic thermal system 100 includes a photovoltaic assembly 1, a detection component 3, a controller 4, a photovoltaic side pump body 5, an electric energy conversion circuit 6, a user side pump body 7, a user object 8, a first heat exchanger 21, a second heat exchanger 22, a third heat exchanger 23, a first control valve 24, a second control valve 25, a multi-way valve 26, a compressor 27, and a fan 28. Among them, the detection component 3 is a first temperature sensor 31 and a second temperature sensor 32, and the multi-way valve 26 is a four-way valve.

[0079] The first heat exchanger 21 and the third heat exchanger 23 include two input ends and two output ends. The first output end of the first heat exchanger 21 is connected to the first control valve 24 and the second control valve 25. The first control valve 24 is connected to the input end of the second heat exchanger 22. The second control valve 25 is connected to the second input end of the third heat exchanger 23. The second output end of the third heat exchanger 23 is connected to the air inlet of the compressor. The output end of the second heat exchanger 22 is connected to the first port of the four-way valve. The first port of the four-way valve is communicated with the second port. The second port of the four-way valve is connected to the air inlet of the compressor. The air outlet of the compressor is connected to the third port of the four-way valve. The third port is communicated with the fourth port. The fourth port of the four-way valve is connected to the first input end of the first heat exchanger 21. The first input end and the first output end of the third heat exchanger 23 are connected to the photovoltaic module 1 to form a circulation loop. The first temperature sensor 31 is arranged between the first input end of the third heat exchanger 23 and the photovoltaic module 1. The second temperature sensor 32 and the photovoltaic side pump body 5 are arranged between the first output end of the third heat exchanger 23 and the photovoltaic module 1. The second input end and the second output end of the first heat exchanger 21 are connected to the user object 8 to form a circulation loop. The user side pump body 7 is arranged between the first heat exchanger 21 and the user object 8.

[0080] When the photovoltaic thermal system 100 is in the first heating mode, the first control valve 24 is closed, the second control valve 25 is opened, the fan 28 is turned off, and the liquid refrigerant flows out through the first output end of the first heat exchanger 21, and becomes a low-temperature and low-pressure two-phase state after passing through the second control valve 25, and enters the third heat exchanger 23 through the second input end of the third heat exchanger 23. The photovoltaic side pump body 5 is running, so that the heat of the photovoltaic component 1 is brought to the third heat exchanger 23 through the heat exchange medium to exchange heat with the refrigerant. The refrigerant absorbs the heat of the photovoltaic component 1 in the third heat exchanger 23 and becomes a gaseous state. It flows to the air inlet of the compressor 27 through the second output end of the third heat exchanger 23. The high-temperature and high-pressure refrigerant discharged from the air outlet of the compressor 27 reaches the first input end of the first heat exchanger 21 through the third port and the fourth port of the four-way valve. After the high-temperature and high-pressure refrigerant transfers heat to water in the first heat exchanger 21, it becomes liquid and flows out from the first output end of the first heat exchanger 21. After the high-temperature and high-pressure refrigerant transfers heat to water in the first heat exchanger 21, the water that absorbs the heat is output through the second output end of the first heat exchanger 21 and is transferred to the user 8 through the user-side pump body 7. After the heat exchange medium absorbs the heat of the photovoltaic module 1, it enters the third heat exchanger 23 through the first input end of the third heat exchanger 23, exchanges heat with the refrigerant in the third heat exchanger 23, and then flows to the photovoltaic module 1 through the first output end of the third heat exchanger 23 to absorb heat.

[0081] When the photovoltaic thermal system 100 is in the second heating mode, the first control valve 24 is opened, the second control valve 25 is closed, the fan 28 is opened, and the photovoltaic side pump body 5 is closed. The liquid refrigerant flows out through the first output end of the first heat exchanger 21, and becomes a low-temperature and low-pressure two-phase state after passing through the first control valve 24, and enters the second heat exchanger through the input end of the second heat exchanger 22. The fan 28 is running, so that the refrigerant absorbs heat in the air and becomes a gaseous state, and flows to the first port of the four-way valve through the output end of the second heat exchanger 22, and enters the air inlet of the compressor 27 through the first port and the second port of the four-way valve. The high-temperature and high-pressure refrigerant discharged from the air outlet of the compressor 27 reaches the first input end of the first heat exchanger 21 through the third port and the fourth port of the four-way valve. After the high-temperature and high-pressure refrigerant transfers heat to water in the first heat exchanger 21, it becomes liquid and flows out from the first output end of the first heat exchanger 21. After the high-temperature and high-pressure refrigerant transfers heat to water in the first heat exchanger 21 , the water that absorbs the heat is output through the second output end of the first heat exchanger 21 and is transferred to the user object 8 through the user-side pump body 7 .

[0082] When the photovoltaic thermal system 100 is in the third heating mode, the first control valve 24, the second control valve 25, the fan 28, and the photovoltaic side pump body 5 are all opened, and the liquid refrigerant flows out through the first output end of the first heat exchanger 21. A part of the refrigerant becomes a low-temperature and low-pressure two-phase state after passing through the second control valve 25, and enters the third heat exchanger 23 through the second input end of the third heat exchanger 23. The photovoltaic side pump body 5 is running, so that the heat of the photovoltaic component 1 is brought to the third heat exchanger 23 through the heat exchange medium to exchange heat with the refrigerant. The refrigerant absorbs the heat of the photovoltaic component 1 in the third heat exchanger 23 and becomes a gas, and flows to the air inlet of the compressor 27 through the second output end of the third heat exchanger 23; another part of the refrigerant passes through the first control valve 24 and becomes The low-temperature and low-pressure two-phase state enters the second heat exchanger 22 through the input end of the second heat exchanger 22, so that the refrigerant absorbs heat from the air in the second heat exchanger 22 and becomes gaseous, flows to the first port of the four-way valve through the output end of the second heat exchanger 22, and enters the air inlet of the compressor 27 through the first port and the second port of the four-way valve; the compressor 27 processes the gaseous refrigerant flowing out of the third heat exchanger 23 and the second heat exchanger 22, and discharges the high-temperature and high-pressure refrigerant through the outlet, and the high-temperature and high-pressure refrigerant reaches the first input end of the first heat exchanger 21 through the third port and the fourth port of the four-way valve. After the high-temperature and high-pressure refrigerant transfers heat to water in the first heat exchanger 21, it becomes liquid and flows out from the first output end of the first heat exchanger 21. After the high-temperature and high-pressure refrigerant transfers heat to water in the first heat exchanger 21, the water that absorbs heat is output through the second output end of the first heat exchanger 21, and is transferred to the user object 8 through the user-side pump body 7. After absorbing the heat of the photovoltaic module 1, the heat exchange medium enters the third heat exchanger 23 through the first input end of the third heat exchanger 23, exchanges heat with the refrigerant in the third heat exchanger 23, and then flows to the photovoltaic module 1 through the first output end of the third heat exchanger 23 to absorb heat.

[0083] See also Figure 5 , Figure 5 1 is a flow chart of an embodiment of a control method for a photovoltaic thermal system provided by the present application, the method comprising:

[0084] S51: receiving detection parameters output by a detection component in a photovoltaic thermal system.

[0085] S52: Control the openings of the first control valve and the second control valve based on the detected parameters.

[0086] The photovoltaic thermal system is a photovoltaic thermal system provided by any of the above embodiments. The detection parameter is at least partially used to characterize the light intensity. The opening of the first control valve and the second control valve is controlled based on the light intensity characterized by the detection parameter. Specifically, the target heat exchange of the third heat exchanger can be determined based on the light intensity, and the actual heat exchange of the third heat exchanger can be controlled to approach the target heat exchange by adjusting the opening of the second control valve. The opening of the first control valve is then controlled based on the opening of the second control valve.

[0087] This embodiment can be executed by a controller in a photovoltaic thermal system. For the specific process of each step in this embodiment, please refer to the specific process executed by the aforementioned controller, which will not be repeated here. It can be understood that this embodiment can also be executed by other devices.

[0088] See also Figure 6 , Figure 6 It is a schematic diagram of the framework structure of an embodiment of an electronic device provided in the present application.

[0089] The electronic device 60 includes a memory 601 and a processor 602. The memory 601 stores program instructions. The processor 602 is used to execute the program instructions stored in the memory 601 to implement the steps of any of the above-mentioned photovoltaic thermal system control method implementation methods. In a specific implementation scenario, the electronic device 60 may include but is not limited to: a microcomputer, a server, and in addition, the electronic device 60 may also include a mobile device such as a laptop computer and a tablet computer, which is not limited here. In a specific implementation, the electronic device 60 may include a controller in a photovoltaic thermal system.

[0090] Specifically, the processor 602 is used to control itself and the memory 601 to implement the steps of any of the above-mentioned method implementation methods. The processor 602 can also be called a CPU (Central Processing Unit). The processor 602 may be an integrated circuit chip with signal processing capabilities. The processor 602 can also be a general-purpose processor, a digital signal processor (Digital Signal Processor, DSP), an application-specific integrated circuit (Application Specific Integrated Circuit, ASIC), a field-programmable gate array (Field-Programmable Gate Array, FPGA) or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components. The general-purpose processor can be a microprocessor or the processor can also be any conventional processor, etc. In addition, the processor 602 can be implemented by an integrated circuit chip.

[0091] See also Figure 7 , Figure 7It is a schematic diagram of the framework structure of an implementation scheme of a computer-readable storage medium provided in this application.

[0092] The computer-readable storage medium 70 stores program instructions 71 , and when the program instructions 71 are executed by the processor, they are used to implement the steps of any of the above-mentioned photovoltaic thermal system control method implementation methods.

[0093] The computer-readable storage medium 70 may specifically be a medium that can store computer programs, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk, or may be a server that stores the computer program. The server may send the stored computer program to other devices for execution, or may also execute the stored computer program itself.

[0094] If the technical solution of this application involves personal information, the product using the technical solution of this application has clearly informed the personal information processing rules and obtained the individual's voluntary consent before processing the personal information. If the technical solution of this application involves sensitive personal information, the product using the technical solution of this application has obtained the individual's separate consent before processing the sensitive personal information, and at the same time meets the "explicit consent" requirement. For example, on personal information collection devices such as cameras, clear and prominent signs are set to inform that the personal information collection scope has been entered and personal information will be collected. If the individual voluntarily enters the collection scope, it is deemed that he or she agrees to the collection of his or her personal information; or on the device that processes personal information, the personal information processing rules are notified by obvious signs / information, and the individual's authorization is obtained through pop-up information or by asking the individual to upload his or her personal information; among them, the personal information processing rules may include information such as the personal information processor, the purpose of personal information processing, the processing method, and the type of personal information processed.

[0095] The above description is only an implementation method of the present application, and does not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly used in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A photovoltaic thermal system, characterized in that: include: Photovoltaic panels; A refrigerant circulation system, the refrigerant circulation system comprising a first heat exchanger, a second heat exchanger, a third heat exchanger, a first control valve and a second control valve, the first heat exchanger is connected to the second heat exchanger via the first control valve to form a first circulation loop, the first heat exchanger is connected to the third heat exchanger via the second control valve to form a second circulation loop, and the third heat exchanger performs heat exchange with the photovoltaic module; A detection component, used for outputting detection parameters; A controller is connected to the detection component and is used to control the opening of the first control valve and the second control valve based on the detection parameter.

2. The system according to claim 1, characterized in that The detection parameter is at least partially used to characterize light intensity, and the controller is used to control the opening of the first control valve and the second control valve based on the light intensity characterized by the detection parameter.

3. The system according to claim 2, characterized in that The detection component includes a first temperature sensor disposed between the first input end of the third heat exchanger and the photovoltaic assembly, the first temperature sensor being used to detect a first temperature of a heat exchange medium flowing into the first input end of the third heat exchanger, the first temperature being used to characterize the light intensity.

4. The system according to claim 2, characterized in that The detection component also includes a power generation detection component for detecting the power generation of the photovoltaic assembly, and the power generation is used to characterize the light intensity.

5. The system according to claim 2, characterized in that The detection component includes a first temperature sensor disposed between the first input end of the third heat exchanger and the photovoltaic assembly, and a power generation detection component for detecting the power generation of the photovoltaic assembly; the first temperature sensor is used to detect a first temperature of the heat exchange medium flowing into the first input end of the third heat exchanger; The controller is used to calculate the light intensity based on the first temperature and the power generation.

6. The system according to claim 5, characterized in that The detection component further includes a second temperature sensor disposed between the first output end of the third heat exchanger and the photovoltaic assembly, the second temperature sensor being used to detect a second temperature of the heat exchange medium flowing out of the second output end of the third heat exchanger; The controller is used to calculate the light intensity based on the first temperature, the second temperature and the power generation.

7. The system according to claim 2, characterized in that The controller is used to control the opening of the second control valve based on the target heat exchange amount of the third heat exchanger, and to control the opening of the first control valve based on the opening of the second control valve; wherein the target heat exchange amount is determined by the light intensity.

8. The system according to claim 7, characterized in that The controller is used to determine a target heat exchange amount of the third heat exchanger based on the light intensity and the heat load of the first heat exchanger.

9. The system according to claim 7, characterized in that The controller controls the opening of the second control valve so that the actual heat exchange amount of the third heat exchanger approaches the target heat exchange amount; The detection component includes a first temperature sensor arranged between the first input end of the third heat exchanger and the photovoltaic component, and a second temperature sensor arranged between the first output end of the third heat exchanger and the photovoltaic component. The temperature difference output by the first temperature sensor and the second temperature sensor is used to characterize the actual heat exchange amount.

10. The system according to claim 9, characterized in that The controller controls the opening of the second control valve so that the actual heat exchange amount of the third heat exchanger approaches the target heat exchange amount, including: In response to the target heat exchange amount being greater than the actual heat exchange amount, the opening of the second control valve is increased; and / or, in response to the target heat exchange amount being less than the actual heat exchange amount, the opening of the second control valve is decreased.

11. The system according to claim 7, characterized in that The controller is used to increase or decrease the opening of the first control valve based on the opening of the second control valve and the subcooling degree of the second heat exchanger.

12. The system according to claim 2, characterized in that The photovoltaic thermal system is provided with a first light intensity threshold and a second light intensity threshold, and the controller is configured to switch to a first heating mode in response to the light intensity being not less than the first light intensity threshold, wherein the first control valve is closed and the second control valve is opened; The controller is configured to switch to a second heating mode in response to the light intensity being less than the second light intensity threshold, wherein the first control valve is opened and the second control valve is closed; The controller is configured to switch to a third heating mode in response to the light intensity being between the first light intensity threshold and the second light intensity threshold, wherein the first control valve and the second control valve are both open; The first light intensity threshold is greater than the second light intensity threshold.

13. The system according to claim 12, characterized in that The controller is configured to adjust the first light intensity threshold and / or the second light intensity threshold based on a heat load of the first heat exchanger.

14. The system according to claim 1, characterized in that The input end of the second heat exchanger is connected to the output end of the first heat exchanger via the first control valve, and the output end of the second heat exchanger is connected to the input end of the first heat exchanger; The second input end of the third heat exchanger is connected to the output end of the first heat exchanger via the second control valve, and the second output end of the third heat exchanger is connected to the input end of the first heat exchanger.

15. The system according to claim 14, characterized in that The refrigerant circulation system also includes a compressor, and the output end of the second heat exchanger and the second output end of the third heat exchanger are both connected to the input end of the first heat exchanger through the compressor, wherein the connection between the compressor and at least two of the first heat exchanger, the second heat exchanger and the third heat exchanger is achieved using a multi-way valve.

16. The system according to claim 1, characterized in that At least one of the first control valve and the second control valve is any one of an expansion valve, a throttle valve, and a capillary tube.

17. The system according to claim 1, characterized in that The photovoltaic thermal system further comprises at least one of the following: A photovoltaic side pump body, the photovoltaic side pump body is arranged between the photovoltaic assembly and the third heat exchanger, and is used to drive the flow of the heat exchange medium between the photovoltaic assembly and the third heat exchanger; A heat storage device, disposed between the photovoltaic assembly and the third heat exchanger; An electric energy conversion circuit is electrically connected to the photovoltaic assembly and the controller, and is used for converting the electric energy output by the photovoltaic assembly into alternating current.

18. The system according to claim 1, characterized in that The photovoltaic assembly further includes a heat collector; or the third heat exchanger is a fluorine cold plate heat collector.

19. The system according to claim 1, characterized in that The second heat exchanger is an air source heat exchanger using air as a heat source; And / or, the third heat exchanger is a medium source heat exchanger using a heat exchange medium as a heat source.

20. The system according to claim 1, characterized in that The number of the second heat exchanger and the first control valve is multiple groups; the first heat exchanger is connected to the second heat exchanger in the same group through the first control valve of each group, so as to form multiple groups of the first circulation loops; or There are multiple second heat exchangers connected in series, and the first heat exchanger is connected to the series sequence formed by the multiple second heat exchangers through the first control valve.

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