Household Photovoltaic System and Its Thermal Management Control Method

Abstract

The present invention provides a household photovoltaic system and its thermal management control method. The household photovoltaic system includes a photovoltaic panel layer, a battery layer, a controller and inverter layer, a heat pump layer and a heat pump assembly. The photovoltaic panel layer, the battery layer and the controller and inverter layer are spaced apart by a first heat exchanger sandwich layer, a second heat exchanger sandwich layer and a third heat exchanger sandwich layer in the heat pump assembly, and the temperature of the photovoltaic panel layer, the battery layer and the controller and inverter layer is regulated respectively by using the first heat exchanger sandwich layer, the second heat exchanger sandwich layer and the third heat exchanger sandwich layer. Applying the household photovoltaic system of the present invention can meet the temperature regulation requirements of each layer, reduce the influence of too high and too low temperatures on the power generation efficiency of the photovoltaic panels, and ensure the temperature rise reliability of the inverter system and the battery.

Description

Technical Field

[0001] The present invention relates to the technical field of photovoltaic systems. Specifically, it relates to a household photovoltaic system and also to a thermal management control method for the household photovoltaic system. Background Art

[0002] In the existing photovoltaic system, the high temperature of the photovoltaic panel in summer will reduce the power generation efficiency, and in winter, the low temperature will also affect the power generation efficiency. At the same time, the performance and service life of the energy storage battery and the inverter system are also closely related to the temperature. The energy storage battery and the inverter system need to meet certain working temperature requirements. Too high or too low temperature will cause the energy storage battery to not work properly.

[0003] In an existing method, the photovoltaic system places the energy storage battery cabinet outdoors and connects it to the heat pump heating and cooling system indoors. There is no need to set up an air conditioner for the energy storage system separately. The heat pump heating and cooling system is used to actively solve the temperature control problem of the energy storage battery cabinet and enhance the safety of the energy storage battery.

[0004] However, the temperature requirements of the photovoltaic panel and the inverter system are not considered in this solution. At the same time, the temperature requirements of the photovoltaic panel, the energy storage battery and the inverter system are different. How to perform thermal management on the core components of the photovoltaic system is also a research direction.

[0005] Therefore, a more optimized photovoltaic system needs to be considered. Summary of the Invention

[0006] The first object of the present invention is to provide a household photovoltaic system that can reduce the influence of high temperature and low temperature on the power generation efficiency of the photovoltaic panel and ensure the temperature rise reliability of the inverter system and the battery.

[0007] The second object of the present invention is to provide a thermal management control method for a household photovoltaic system that can reduce the influence of high temperature and low temperature on the power generation efficiency of the photovoltaic panel and ensure the temperature rise reliability of the inverter system and the battery.

[0008] To achieve the above first object, the household photovoltaic system provided by the present invention includes a photovoltaic panel layer, a battery layer, a controller-inverter layer, a heat pump layer, and a heat pump assembly. The photovoltaic panel layer, the battery layer, the controller-inverter layer, and the heat pump layer are arranged in sequence from top to bottom in the vertical direction; the heat pump assembly includes a compressor, a four-way valve, a heat exchanger, a first heat exchanger interlayer, a second heat exchanger interlayer, and a third heat exchanger interlayer. The compressor, the four-way valve, the heat exchanger, the first heat exchanger interlayer, the second heat exchanger interlayer, and the third heat exchanger interlayer form a heat exchange circuit, and the first heat exchanger interlayer, the second heat exchanger interlayer, and the third heat exchanger interlayer are connected in parallel to the heat exchange circuit; the first heat exchanger interlayer is spaced between the photovoltaic panel layer and the battery layer, the second heat exchanger interlayer is spaced between the battery layer and the controller-inverter layer, the third heat exchanger interlayer is spaced between the controller-inverter layer and the heat pump layer, and the compressor, the four-way valve, and the heat exchanger are located in the heat pump layer; electronic expansion valves are provided at the liquid inlet ends of the first heat exchanger interlayer, the second heat exchanger interlayer, and the third heat exchanger interlayer; temperature sensors for detecting the temperature of each layer are provided on the photovoltaic panel layer, the battery layer, and the controller-inverter layer.

[0009] As can be seen from the above solution, the household photovoltaic system of the present invention can use the first heat exchanger interlayer, the second heat exchanger interlayer, and the third heat exchanger interlayer in the heat pump assembly to separately control the temperature of the photovoltaic panel layer, the battery layer, and the controller-inverter layer by setting the heat pump assembly and spacing the photovoltaic panel layer, the battery layer, and the controller-inverter layer with the first heat exchanger interlayer, the second heat exchanger interlayer, and the third heat exchanger interlayer in the heat pump assembly, meet the temperature control requirements of each layer, reduce the influence of too high and too low temperatures on the power generation efficiency of the photovoltaic panels, and ensure the temperature rise reliability of the inverter system and the battery.

[0010] In a further solution, at least one of the first heat exchanger interlayer, the second heat exchanger interlayer, and the third heat exchanger interlayer is provided with a first end liquid collecting pipe, a second end liquid collecting pipe, and a microchannel group. The first ends of the microchannels in the microchannel group are communicated with the first end liquid collecting pipe, the second ends of the microchannels are communicated with the second end liquid collecting pipe, the first end liquid collecting pipe is also connected to the heat exchanger through an electronic expansion valve, and the second end liquid collecting pipe is also connected to one end of the four-way valve.

[0011] As can be seen, the first heat exchanger interlayer, the second heat exchanger interlayer, and the third heat exchanger interlayer can have the advantages of high heat transfer efficiency, not easy to block, compact structure, light weight, energy saving and environmental protection by setting the microchannel group for heat exchange.

[0012] In a further solution, a first fan and a second fan are provided in the battery layer. The first fan is located at the top of the battery layer, and the second fan is located at the bottom of the battery layer; a third fan is provided in the controller-inverter layer, and the third fan is located at the bottom of the controller-inverter layer.

[0013] As can be seen, by providing fans in the battery layer and the controller-inverter layer, the heat exchange effect can be accelerated by the fans, and the accuracy of temperature control can be improved.

[0014] In a further solution, the battery layer and the controller inverter layer are hermetically arranged.

[0015] It can be seen that, with the battery layer and the controller inverter layer hermetically arranged, no condensate will be generated inside, which can ensure the safety of the circuit.

[0016] To achieve the second object of the present invention, the thermal management control method of the household photovoltaic system provided by the present invention includes: controlling the heat pump assembly to enter the refrigeration mode or the heating mode; obtaining the current ambient temperature, the current temperature of the photovoltaic panels in the photovoltaic panel layer, the current temperature of the battery layer in the battery layer, and the current temperature of the control layer in the controller inverter layer; and controlling the heat pump assembly to adjust the temperatures of the photovoltaic panel layer, the battery layer, and the controller inverter layer according to the current ambient temperature, the current photovoltaic panel temperature, the current battery layer temperature, and the current control layer temperature, so that the temperatures of the photovoltaic panel layer, the battery layer, and the controller inverter layer are within the corresponding preset temperature ranges of each layer.

[0017] As can be seen from the above solution, when the heat pump assembly of the thermal management control method of the household photovoltaic system of the present invention enters the refrigeration mode or the heating mode, the heat pump assembly is controlled to adjust the temperatures of the photovoltaic panel layer, the battery layer, and the controller inverter layer according to the current ambient temperature, the current photovoltaic panel temperature, the current battery layer temperature, and the current control layer temperature, so that each layer can be within the corresponding preset temperature range, meeting the temperature control requirements of each layer, reducing the influence of too high or too low temperatures on the power generation efficiency of the photovoltaic panels, and ensuring the temperature rise reliability of the inverter system and the battery.

[0018] In a further solution, the step of controlling the heat pump assembly to adjust the temperatures of the photovoltaic panel layer, the battery layer, and the controller inverter layer according to the current ambient temperature, the current photovoltaic panel temperature, the current battery layer temperature, and the current control layer temperature includes: obtaining the base frequency corresponding to the compressor at the current ambient temperature; obtaining the first additional frequency corresponding to the compressor at the current photovoltaic panel temperature, the second additional frequency corresponding to the compressor at the current battery layer temperature, and the third additional frequency corresponding to the compressor at the current control layer temperature; adding the base frequency, the first additional frequency, the second additional frequency, and the third additional frequency to obtain the total control frequency of the compressor, and controlling the compressor to operate with the total control frequency.

[0019] It can be seen that when controlling the compressor frequency, the base frequency corresponding to the compressor is determined according to the current ambient temperature, and the corresponding additional frequencies are determined according to the current temperatures of each layer, so that the sum of the base frequency and the additional frequencies of each layer is used as the total control frequency to control the operation of the compressor, which is beneficial to improving the accuracy of compressor frequency control and reducing energy consumption.

[0020] In a further solution, the steps of controlling the heat pump assembly to adjust the temperatures of the photovoltaic panel layer, the battery layer, and the controller inverter layer according to the current ambient temperature, the current photovoltaic panel temperature, the current battery layer temperature, and the current control layer temperature further include: obtaining the first opening degree of the electronic expansion valve corresponding to the first heat exchanger interlayer at the current ambient temperature and the current photovoltaic panel temperature, controlling the opening degree of the electronic expansion valve corresponding to the first heat exchanger interlayer in an open-loop manner according to the first opening degree, after open-loop control for a first preset duration, controlling the opening degree of the electronic expansion valve corresponding to the first heat exchanger interlayer with a first preset closed-loop control logic; obtaining the second opening degree of the electronic expansion valve corresponding to the second heat exchanger interlayer at the current ambient temperature and the current battery layer temperature, controlling the opening degree of the electronic expansion valve corresponding to the second heat exchanger interlayer in an open-loop manner according to the second opening degree, after open-loop control for a second preset duration, controlling the opening degree of the electronic expansion valve corresponding to the second heat exchanger interlayer with a second preset closed-loop control logic; obtaining the third opening degree of the electronic expansion valve corresponding to the third heat exchanger interlayer at the current ambient temperature and the current control layer temperature, controlling the opening degree of the electronic expansion valve corresponding to the third heat exchanger interlayer in an open-loop manner according to the third opening degree, after open-loop control for a third preset duration, controlling the opening degree of the electronic expansion valve corresponding to the third heat exchanger interlayer with a third preset closed-loop control logic.

[0021] It can be seen that since the required operating temperatures of the photovoltaic panel layer, the battery layer, and the controller inverter layer are different, the temperature required for each layer can be adjusted by controlling the opening degree of the electronic expansion valve of each layer. Therefore, by correspondingly controlling the opening degree of the electronic expansion valve according to the current ambient temperature and the temperature of each layer, the accuracy of temperature control can be improved.

[0022] In a further solution, the first preset closed-loop control logic includes: dynamically adjusting the opening degree of the electronic expansion valve corresponding to the first heat exchanger interlayer to make the current photovoltaic panel temperature fall within a first preset temperature range; and / or the second preset closed-loop control logic includes: dynamically adjusting the opening degree of the electronic expansion valve corresponding to the second heat exchanger interlayer to make the current battery layer temperature fall within a second preset temperature range; and / or the third preset closed-loop control logic includes: dynamically adjusting the opening degree of the electronic expansion valve corresponding to the third heat exchanger interlayer to make the current control layer temperature fall within a third preset temperature range.

[0023] It can be seen that by controlling the opening degree of the electronic expansion valve in a closed-loop manner, the target temperature of each layer can be adjusted faster and better, ensuring the stability of the temperature of each layer.

[0024] In a further solution, a first fan and a second fan are arranged in the battery layer. The first fan is located at the top of the battery layer, and the second fan is located at the bottom of the battery layer. A third fan is arranged in the controller inverter layer, and the third fan is located at the bottom of the controller inverter layer. The steps of controlling the heat pump assembly to adjust the temperatures of the photovoltaic panel layer, the battery layer, and the controller inverter layer according to the current ambient temperature, the current photovoltaic panel temperature, the current battery layer temperature, and the current control layer temperature further include: obtaining the first rotation speed of the first fan and the second rotation speed of the second fan at the current ambient temperature and the current battery layer temperature, controlling the first fan according to the first rotation speed, and controlling the second fan according to the second rotation speed; obtaining the third rotation speed of the third fan at the current ambient temperature and the current control layer temperature, and controlling the third fan according to the third rotation speed.

[0025] It can be seen that by arranging fans in the battery layer and the controller inverter layer, the heat exchange effect can be accelerated by the fans. At the same time, by correspondingly controlling the rotation speeds of the fans according to the current ambient temperature and the temperatures of each layer, the accuracy of temperature control is improved.

[0026] In a further solution, a fourth temperature sensor for detecting the exhaust temperature of the compressor is arranged in the heat pump layer. The steps of controlling the heat pump assembly to adjust the temperatures of the photovoltaic panel layer, the battery layer, and the controller inverter layer according to the current ambient temperature, the current photovoltaic panel temperature, the current battery layer temperature, and the current control layer temperature further include: when the total control frequency of the compressor is greater than the preset frequency, if the exhaust temperature is less than the first preset exhaust temperature, controlling all the opened electronic expansion valves to gradually decrease the adjustment at the first preset opening until the exhaust temperature is greater than the second preset exhaust temperature, where the second preset exhaust temperature is greater than the first preset exhaust temperature; when the compressor is running, if the exhaust temperature is greater than the third preset exhaust temperature, controlling all the opened electronic expansion valves to gradually increase the adjustment at the second preset opening until the exhaust temperature is less than the fourth preset exhaust temperature, where the third preset exhaust temperature is greater than the second preset exhaust temperature, and the fourth preset exhaust temperature is less than the third preset exhaust temperature.

[0027] It can be seen that if the exhaust temperature of the compressor is too low, there will be a phenomenon of liquid suction with the air intake, and liquid hammer may occur. If the exhaust temperature is too high, the life of the motor winding will be reduced. Therefore, it is necessary to control the opening of the electronic expansion valves of each layer according to the exhaust temperature to adjust the exhaust temperature of the compressor. When adjusting the opening of the electronic expansion valves, all the electronic expansion valves act together, which can ensure that the temperature fluctuation of each layer is not too large and guarantee the stability of the temperatures of each layer. Description of the Drawings

[0028] Figure 1 It is a schematic block diagram of the system structure of an embodiment of the household photovoltaic system of the present invention.

[0029] Figure 2It is a schematic structural diagram of the first heat exchanger sandwich layer in the household photovoltaic system embodiment of the present invention.

[0030] Figure 3 It is a flowchart of the heat management control method embodiment of the household photovoltaic system of the present invention.

[0031] The present invention will be further described below in conjunction with the accompanying drawings and embodiments. Specific embodiments

[0032] Household photovoltaic system embodiment:

[0033] In this embodiment, refer to Figure 1 , the household photovoltaic system includes a photovoltaic panel layer 1, a battery layer 2, a controller inverter layer 3, a heat pump layer 4 and a heat pump assembly. The photovoltaic panel layer 1, the battery layer 2, the controller inverter layer 3 and the heat pump layer 4 are arranged in sequence from top to bottom in the vertical direction. The photovoltaic panel layer 1 is used to install photovoltaic panels, the battery layer 2 installs energy storage batteries, and the energy storage batteries are used to supply power to the household photovoltaic system and to an external circuit. The controller inverter layer 3 is used to install control circuits. Preferably, the battery layer 2 and the controller inverter layer 3 are hermetically arranged. The battery layer 2 and the controller inverter layer 3 are hermetically arranged, and no condensate will be generated inside, which can ensure the safety of the circuit.

[0034] In this embodiment, the heat pump assembly includes a compressor 51, a four-way valve 52, a heat exchanger 53, a first heat exchanger sandwich layer 54, a second heat exchanger sandwich layer 55 and a third heat exchanger sandwich layer 56. The compressor 51, the four-way valve 52, the heat exchanger 53, the first heat exchanger sandwich layer 54, the second heat exchanger sandwich layer 55 and the third heat exchanger sandwich layer 56 form a heat exchange circuit, and the first heat exchanger sandwich layer 54, the second heat exchanger sandwich layer 55 and the third heat exchanger sandwich layer 56 are connected in parallel to the heat exchange circuit. The first heat exchanger sandwich layer 54 is spaced between the photovoltaic panel layer 1 and the battery layer 2, the second heat exchanger sandwich layer 55 is spaced between the battery layer 2 and the controller inverter layer 3, the third heat exchanger sandwich layer 56 is spaced between the controller inverter layer 3 and the heat pump layer 4, and the compressor 51, the four-way valve 52 and the heat exchanger 53 are located in the heat pump layer 4.

[0035] In this embodiment, refer to Figure 2, an electronic expansion valve 541, a first end liquid collecting pipe 542, a second end liquid collecting pipe 543 and a microchannel group 544 are arranged in the first heat exchanger interlayer 54. The first ends of the microchannels in the microchannel group 544 are communicated with the first end liquid collecting pipe 542, and the second ends of the microchannels are communicated with the second end liquid collecting pipe 543. The first end liquid collecting pipe 542 is also connected to the heat exchanger 53 through the electronic expansion valve 541, and the second end liquid collecting pipe 543 is connected to one end of the four-way valve 52 through the liquid collecting pipe 57. The structures of the second heat exchanger interlayer 55 and the third heat exchanger interlayer 56 are the same as that of the first heat exchanger interlayer 54, and will not be described herein again. The first heat exchanger interlayer 54, the second heat exchanger interlayer 55 and the third heat exchanger interlayer 56 perform heat exchange by arranging the microchannel group 544, and can have the advantages of high heat transfer efficiency, not easy to block, compact structure, light weight, energy conservation and environmental protection, etc.

[0036] In this embodiment, temperature sensors for detecting the temperatures of each layer are arranged in the photovoltaic panel layer 1, the battery layer 2 and the controller inverter layer 3. Specifically, a first temperature sensor 6 for detecting the temperature of the photovoltaic panel layer 1 is arranged in the photovoltaic panel layer 1, a second temperature sensor 7 for detecting the internal temperature of the battery layer 2 is arranged in the battery layer 2, and a third temperature sensor 8 for detecting the internal temperature of the controller inverter layer 3 is arranged in the controller inverter layer 3. In addition, a fourth temperature sensor (not shown) for detecting the exhaust temperature of the compressor 51 and a fifth temperature sensor (not shown) for detecting the ambient temperature of the household photovoltaic system are arranged in the heat pump layer 4.

[0037] In this embodiment, a first fan 21 and a second fan 22 are arranged in the battery layer 2. The first fan 21 is located at the top of the battery layer 2, and the second fan 22 is located at the bottom of the battery layer 2. A third fan 31 is arranged in the controller inverter layer 3, and the third fan 31 is located at the bottom of the controller inverter layer 3. Preferably, the first fan 21, the second fan 22 and the third fan 31 all blow air towards the positions that need to be cooled in the corresponding layers. By arranging fans in the battery layer 2 and the controller inverter layer 3, the heat exchange effect can be accelerated by the fans, and the accuracy of temperature control can be improved.

[0038] In order to better illustrate the working principle of the household photovoltaic system of the present invention, the heat management control method of the household photovoltaic system will be described below.

[0039] In this embodiment, referring to Figure 3 , when the heat management control method of the household photovoltaic system is working, first step S1 is executed to control the heat pump assembly to enter the refrigeration mode or the heating mode. The refrigeration mode or the heating mode can be automatically controlled according to the range of the current ambient temperature, or can be manually controlled.

[0040] After entering the refrigeration mode or the heating mode, step S2 is executed to obtain the current ambient temperature, the current photovoltaic panel temperature, the current battery layer temperature, and the current control layer temperature. For the convenience of temperature control of the photovoltaic panel layer 1, the battery layer 2, and the controller inverter layer 3, temperature adjustment is performed according to the current ambient temperature, the current photovoltaic panel temperature, the current battery layer temperature, and the current control layer temperature. The current ambient temperature can be obtained through the fifth temperature sensor, the current photovoltaic panel temperature can be obtained through the first temperature sensor 6, the current battery layer temperature can be obtained through the second temperature sensor 7, and the current control layer temperature can be obtained through the third temperature sensor 8.

[0041] After obtaining the current ambient temperature, the current photovoltaic panel temperature, the current battery layer temperature, and the current control layer temperature, step S3 is executed to control the heat pump assembly to adjust the temperatures of the photovoltaic panel layer 1, the battery layer 2, and the controller inverter layer 3 according to the current ambient temperature, the current photovoltaic panel temperature, the current battery layer temperature, and the current control layer temperature, so that the temperatures of the photovoltaic panel layer 1, the battery layer 2, and the controller inverter layer 3 are within the corresponding preset temperature ranges of each layer. Controlling the heat pump assembly to adjust the temperatures of the photovoltaic panel layer 1, the battery layer 2, and the controller inverter layer 3 according to the current ambient temperature, the current photovoltaic panel temperature, the current battery layer temperature, and the current control layer temperature can make each layer within the corresponding preset temperature range, meet the temperature control requirements of each layer, reduce the influence of too high and too low temperatures on the power generation efficiency of the photovoltaic panel, and ensure the temperature rise reliability of the inverter system and the battery.

[0042] In this embodiment, the steps of controlling the heat pump assembly to adjust the temperatures of the photovoltaic panel layer 1, the battery layer 2, and the controller inverter layer 3 according to the current ambient temperature, the current photovoltaic panel temperature, the current battery layer temperature, and the current control layer temperature include: obtaining the base frequency corresponding to the compressor 51 at the current ambient temperature; obtaining the first additional frequency corresponding to the compressor 51 at the current photovoltaic panel temperature, the second additional frequency corresponding to the compressor 51 at the current battery layer temperature, and the third additional frequency corresponding to the compressor 51 at the current control layer temperature; adding the base frequency, the first additional frequency, the second additional frequency, and the third additional frequency to obtain the total control frequency of the compressor 51, and controlling the operation of the compressor 51 with the total control frequency. Determining the base frequency corresponding to the compressor 51 according to the current ambient temperature, and determining the corresponding additional frequencies according to the current temperatures of each layer, so as to use the sum of the base frequency and the additional frequencies of each layer as the total control frequency to control the operation of the compressor 51, which is beneficial to improving the accuracy of the frequency control of the compressor 51 and reducing energy consumption.

[0043] In an example of compressor frequency control, when entering the refrigeration mode, when the current ambient temperature Tw is within 10°C < Tw ≤ 20°C, the base frequency is 0. At this time, if the current photovoltaic panel temperature Tg is greater than 50°C, the first additional frequency is 15 + (Tg - 50) Hz; if the current photovoltaic panel temperature Tg is less than or equal to 50°C, the first additional frequency is 0. If the current battery layer temperature Td is greater than 40°C, the second additional frequency is 20 + (Td - 40) Hz; if the current battery layer temperature Td is less than or equal to 40°C, the second additional frequency is 0. If the current control layer temperature Tk is greater than 40°C, the third additional frequency is 30 + (Tk - 40) Hz; if the current control layer temperature Tk is less than or equal to 40°C, the third additional frequency is 0. When the current ambient temperature Tw is within 20°C < Tw ≤ 45°C, the base frequency is 40 Hz. At this time, if the current photovoltaic panel temperature Tg is greater than 50°C, the first additional frequency is 5 + (Tg - 50) Hz; if the current photovoltaic panel temperature Tg is less than or equal to 50°C, the first additional frequency is 0. If the current battery layer temperature Td is greater than 40°C, the second additional frequency is 10 + (Td - 40) Hz; if the current battery layer temperature Td is less than or equal to 40°C, the second additional frequency is 0. If the current control layer temperature Tk is greater than 50°C, the third additional frequency is 20 + (Tk - 50) Hz; if the current control layer temperature Tk is less than or equal to 50°C, the third additional frequency is 0. When the current ambient temperature Tw is within 45°C < Tw, the total control frequency of the compressor 51 is at the preset maximum frequency.

[0044] When entering the heating mode, when the current ambient temperature Tw is within 0°C < Tw ≤ 10°C, the base frequency is 0. At this time, the first additional frequency is 0. If the current battery layer temperature Td is less than 20°C, the second additional frequency is 10 + (20 - Td) Hz; if the current battery layer temperature Td is greater than or equal to 20°C, the second additional frequency is 0. The third additional frequency is 0. When the current ambient temperature Tw is within Tw ≤ 0°C, the base frequency is 40 Hz. At this time, if the current photovoltaic panel temperature Tg is less than 0°C, the first additional frequency is 20 + (0 - Tg) Hz; if the current photovoltaic panel temperature Tg is greater than or equal to 0°C, the first additional frequency is 0. If the current battery layer temperature Td is less than 20°C, the second additional frequency is 10 + (20 - Td) Hz; if the current battery layer temperature Td is greater than or equal to 20°C, the second additional frequency is 0. If the current control layer temperature Tk is less than 0°C, the third additional frequency is 20 + (0 - Tk) Hz; if the current control layer temperature Tk is greater than or equal to 0°C, the third additional frequency is 0.

[0045] In this embodiment, the steps of controlling the heat pump assembly to adjust the temperatures of the photovoltaic panel layer 1, the battery layer 2, and the controller inverter layer 3 according to the current ambient temperature, the current photovoltaic panel temperature, the current battery layer temperature, and the current control layer temperature further include: obtaining the first opening degree of the electronic expansion valve 541 corresponding to the first heat exchanger interlayer 54 at the current ambient temperature and the current photovoltaic panel temperature, controlling the opening degree of the electronic expansion valve 541 corresponding to the first heat exchanger interlayer 54 in an open-loop manner according to the first opening degree, after open-loop controlling for the first preset duration, controlling the opening degree of the electronic expansion valve 541 corresponding to the first heat exchanger interlayer 54 with the first preset closed-loop control logic; obtaining the second opening degree of the electronic expansion valve 541 corresponding to the second heat exchanger interlayer 55 at the current ambient temperature and the current battery layer temperature, controlling the opening degree of the electronic expansion valve 541 corresponding to the second heat exchanger interlayer 55 in an open-loop manner according to the second opening degree, after open-loop controlling for the second preset duration, controlling the opening degree of the electronic expansion valve 541 corresponding to the second heat exchanger interlayer 55 with the second preset closed-loop control logic; obtaining the third opening degree of the electronic expansion valve 541 corresponding to the third heat exchanger interlayer 56 at the current ambient temperature and the current control layer temperature, controlling the opening degree of the electronic expansion valve 541 corresponding to the third heat exchanger interlayer 56 in an open-loop manner according to the third opening degree, after open-loop controlling for the third preset duration, controlling the opening degree of the electronic expansion valve 541 corresponding to the third heat exchanger interlayer 56 with the third preset closed-loop control logic.

[0046] In an example of controlling the electronic expansion valve, when entering the refrigeration mode, when the current ambient temperature Tw is in the range of 10°C < Tw ≤ 20°C, at this time, if the current photovoltaic panel temperature Tg is greater than 50°C, then the first opening degree is 150 + (Tg - 50) * 4, if the current photovoltaic panel temperature Tg is less than or equal to 50°C, then the first opening degree is 0; if the current battery layer temperature Td is greater than 40°C, then the second opening degree is 120 + (Td - 40) * 3, if the current battery layer temperature Td is less than or equal to 40°C, then the second opening degree is 0; if the current control layer temperature Tk is greater than 40°C, then the third opening degree is 150 + (Tk - 40) * 2, if the current control layer temperature Tk is less than or equal to 40°C, then the third opening degree is 0. When the current ambient temperature Tw is in the range of 20°C < Tw, at this time, if the current photovoltaic panel temperature Tg is greater than 50°C, then the first opening degree is 150 + (Tg - 50) * 6, if the current photovoltaic panel temperature Tg is less than or equal to 50°C, then the first opening degree is 0; if the current battery layer temperature Td is greater than 40°C, then the second opening degree is 120 + (Td - 40) * 6, if the current battery layer temperature Td is less than or equal to 40°C, then the second opening degree is 0; if the current control layer temperature Tk is greater than 50°C, then the third opening degree is 150 + (Tk - 40) * 6, if the current control layer temperature Tk is less than or equal to 40°C, then the third opening degree is 0.

[0047] When entering the heating mode, when the current ambient temperature Tw is in the range of 0 < Tw ≤ 10°C, at this time, the first opening degree is 0; if the current battery layer temperature Td is less than 20°C, the second opening degree is 80 + (20 - Td), if the current battery layer temperature Td is greater than or equal to 20°C, the second opening degree is 0; the third opening degree is 0. When the current ambient temperature Tw is in the range of Tw ≤ 0°C, at this time, if the current photovoltaic panel temperature Tg is less than 0°C, the first opening degree is 90 + (0 - Tg) * 5, if the current photovoltaic panel temperature Tg is greater than or equal to 0°C, the first opening degree is 0; if the current battery layer temperature Td is less than 20°C, the second opening degree is 90 + (20 - Td) * 3, if the current battery layer temperature Td is greater than or equal to 20°C, the second opening degree is 0; if the current control layer temperature Tk is less than 0°C, the third opening degree is 90 + (0 - Tk) * 5, if the current control layer temperature Tk is greater than or equal to 0°C, the third opening degree is 0.

[0048] The first preset closed-loop control logic includes: dynamically adjusting the opening degree of the electronic expansion valve 541 corresponding to the first heat exchanger interlayer 54 to make the current photovoltaic panel temperature within the first preset temperature range, where the first preset temperature range can be preset according to experimental data. The second preset closed-loop control logic includes: dynamically adjusting the opening degree of the electronic expansion valve 541 corresponding to the second heat exchanger interlayer 55 to make the current battery layer temperature within the second preset temperature range, where the second preset temperature range can be preset according to experimental data. The third preset closed-loop control logic includes: dynamically adjusting the opening degree of the electronic expansion valve 541 corresponding to the third heat exchanger interlayer 56 to make the current control layer temperature within the third preset temperature range, where the third preset temperature range can be preset according to experimental data. By controlling the opening degree of the electronic expansion valve 541 in a closed loop, the target temperatures of each layer can be adjusted faster and better, ensuring the stability of the temperatures of each layer.

[0049] In this embodiment, the steps of controlling the heat pump assembly to adjust the temperatures of the photovoltaic panel layer 1, the battery layer 2, and the controller inverter layer 3 according to the current ambient temperature, the current photovoltaic panel temperature, the current battery layer temperature, and the current control layer temperature further include: obtaining the first rotation speed of the first fan 21 and the second rotation speed of the second fan 22 at the current ambient temperature and the current battery layer temperature, controlling the first fan 21 according to the first rotation speed, and controlling the second fan 22 according to the second rotation speed; obtaining the third rotation speed of the third fan 31 at the current ambient temperature and the current control layer temperature, and controlling the third fan 31 according to the third rotation speed. By arranging fans in the battery layer 2 and the controller inverter layer 3, the heat exchange effect can be accelerated by the fans. At the same time, by correspondingly controlling the rotation speeds of the fans according to the current ambient temperature and the temperatures of each layer, the accuracy of temperature control is improved.

[0050] In an example of controlling the fan speed, when entering the cooling mode, when the current ambient temperature Tw is in the range of 10°C < Tw ≤ 20°C, at this time, if the current battery layer temperature Td is greater than 40°C, the first speed is 400 rpm and the second speed is 800 rpm; if the current battery layer temperature Td is less than or equal to 40°C, the first speed is 0 and the second speed is 0. If the current control layer temperature Tk is greater than 40°C, the third speed is 600 rpm; if the current control layer temperature Tk is less than or equal to 40°C, the speed is 0. When the current ambient temperature Tw is in the range of 20°C < Tw, at this time, if the current battery layer temperature Td is greater than 40°C, the first speed is 1000 rpm and the second speed is 1000 rpm; if the current battery layer temperature Td is less than or equal to 40°C, the first speed is 0 and the second speed is 0. If the current control layer temperature Tk is greater than 50°C, the third speed is 1000 rpm; if the current control layer temperature Tk is less than or equal to 40°C, the third speed is 0.

[0051] When entering the heating mode, when the current ambient temperature Tw is in the range of 0 < Tw ≤ 10°C, at this time, if the current battery layer temperature Td is less than 20°C, the first speed is 800 rpm and the second speed is 400 rpm; if the current battery layer temperature Td is greater than or equal to 20°C, the first speed is 0 and the second speed is 0. If the current control layer temperature Tk is greater than 60°C, the third speed is 600 rpm; if the current control layer temperature Tk is less than or equal to 60°C, the speed is 0. When the current ambient temperature Tw is ≤ 0°C, at this time, if the current battery layer temperature Td is less than 20°C, the first speed is 1000 rpm and the second speed is 1000 rpm; if the current battery layer temperature Td is greater than or equal to 20°C, the first speed is 0 and the second speed is 0. If the current control layer temperature Tk is less than 0°C, the third speed is 8000 rpm; if the current control layer temperature Tk is greater than or equal to 0°C, the third speed is 0.

[0052] In this embodiment, the steps of controlling the heat pump assembly to adjust the temperatures of the photovoltaic panel layer 1, the battery layer 2, and the controller inverter layer 3 according to the current ambient temperature, the current photovoltaic panel temperature, the current battery layer temperature, and the current control layer temperature further include: when the total control frequency of the compressor 51 is greater than the preset frequency, if the exhaust temperature is less than the first preset exhaust temperature, control all the opened electronic expansion valves 541 to gradually decrease the adjustment at a first preset opening until the exhaust temperature is greater than the second preset exhaust temperature, where the second preset exhaust temperature is greater than the first preset exhaust temperature; when the compressor 51 is running, if the exhaust temperature is greater than the third preset exhaust temperature, control all the opened electronic expansion valves 541 to gradually increase the adjustment at a second preset opening until the exhaust temperature is less than the fourth preset exhaust temperature, where the third preset exhaust temperature is greater than the second preset exhaust temperature, and the fourth preset exhaust temperature is less than the third preset exhaust temperature. Among them, the preset frequency, the first preset exhaust temperature, the second preset exhaust temperature, the third preset exhaust temperature, and the fourth preset exhaust temperature can be preset according to experimental data. Preferably, the preset frequency is 30 Hz, the first preset exhaust temperature is 40 °C, the second preset exhaust temperature is 50 °C, the third preset exhaust temperature is 100 °C, and the fourth preset exhaust temperature is 85 °C.

[0053] Since there will be a phenomenon of liquid suction with liquid hitting when the exhaust temperature of the compressor 51 is too low, and the life of the motor winding will be reduced if the exhaust temperature is too high. Therefore, the opening degree of the electronic expansion valve 541 of each layer is controlled according to the exhaust temperature to adjust the exhaust temperature of the compressor 51. When adjusting the opening degree of the electronic expansion valve 541, operating all the valves together can ensure that the temperature fluctuation of each layer is not too large and guarantee the stability of the temperature of each layer.

[0054] As can be seen from the above, the household photovoltaic system of the present invention can use the first heat exchanger sandwich layer 54, the second heat exchanger sandwich layer 55, and the third heat exchanger sandwich layer 56 in the heat pump assembly to separate the photovoltaic panel layer 1, the battery layer 2, and the controller inverter layer 3 by setting the heat pump assembly, and can respectively control the temperatures of the photovoltaic panel layer 1, the battery layer 2, and the controller inverter layer 3 by using the first heat exchanger sandwich layer 54, the second heat exchanger sandwich layer 55, and the third heat exchanger sandwich layer 56, meet the temperature control requirements of each layer, reduce the influence of too high and too low temperatures on the power generation efficiency of the photovoltaic panel, and ensure the temperature rise reliability of the inverter system and the battery.

[0055] It should be noted that the above is only the preferred embodiment of the present invention, but the design concept of the invention is not limited to this. Any non-substantive modification made to the present invention using this concept also falls within the protection scope of the present invention.

Claims

1. A household photovoltaic system, characterized in that: It includes a photovoltaic panel layer, a battery layer, a controller inverter layer, a heat pump layer and a heat pump assembly, wherein the photovoltaic panel layer, the battery layer, the controller inverter layer and the heat pump layer are arranged in sequence from top to bottom along the vertical direction; The heat pump assembly comprises a compressor, a four-way valve, a heat exchanger, and a first heat exchanger interlayer, a second heat exchanger interlayer, and a third heat exchanger interlayer, wherein the compressor, the four-way valve, the heat exchanger, the first heat exchanger interlayer, the second heat exchanger interlayer, and the third heat exchanger interlayer form a heat exchange loop, and the first heat exchanger interlayer, the second heat exchanger interlayer, and the third heat exchanger interlayer are connected in parallel to the heat exchange loop; The first heat exchanger interlayer separates the photovoltaic panel layer and the battery layer, the second heat exchanger interlayer separates the battery layer and the controller inverter layer, the third heat exchanger interlayer separates the controller inverter layer and the heat pump layer, and the compressor, the four-way valve and the heat exchanger are located in the heat pump layer; The liquid inlet ends of the first heat exchanger interlayer, the second heat exchanger interlayer and the third heat exchanger interlayer are all provided with electronic expansion valves; The photovoltaic panel layer, the battery layer and the controller inverter layer are all provided with temperature sensors for detecting the temperature of each layer; At least one of the first heat exchanger interlayer, the second heat exchanger interlayer and the third heat exchanger interlayer is provided with a first end collecting pipe, a second end collecting pipe and a microchannel group, the first end of the microchannel in the microchannel group is connected to the first end collecting pipe, the second end of the microchannel is connected to the second end collecting pipe, the first end collecting pipe is also connected to the heat exchanger through the electronic expansion valve, and the second end collecting pipe is also connected to one end of the four-way valve.

2. The household photovoltaic system according to claim 1, characterized in that: A first fan and a second fan are arranged in the battery layer, the first fan is located at the top of the battery layer, and the second fan is located at the bottom of the battery layer; A third fan is arranged in the controller inverter layer, and the third fan is located at the bottom of the controller inverter layer.

3. The household photovoltaic system according to claim 2, characterized in that: The battery layer and the controller inverter layer are sealed.

4. A thermal management control method for a household photovoltaic system, characterized in that: The household photovoltaic system applies the household photovoltaic system described in claim 1; The method comprises: Controlling the heat pump assembly to enter a cooling mode or a heating mode; Acquire the current ambient temperature, the current photovoltaic panel temperature of the photovoltaic panel layer, the current battery layer temperature of the battery layer, and the current control layer temperature of the controller inverter layer; The heat pump component is controlled according to the current ambient temperature, the current photovoltaic panel temperature, the current battery layer temperature and the current control layer temperature to adjust the temperature of the photovoltaic panel layer, the battery layer and the controller inverter layer, so that the temperatures of the photovoltaic panel layer, the battery layer and the controller inverter layer are within the preset temperature range corresponding to each layer.

5. The thermal management control method of a household photovoltaic system according to claim 4, characterized in that: The step of controlling the heat pump assembly to adjust the temperature of the photovoltaic panel layer, the battery layer and the controller inverter layer according to the current ambient temperature, the current photovoltaic panel temperature, the current battery layer temperature and the current control layer temperature comprises: Acquire the fundamental frequency corresponding to the compressor at the current ambient temperature; Obtaining a first addition frequency corresponding to the compressor at the current photovoltaic panel temperature, a second addition frequency corresponding to the compressor at the current battery layer temperature, and a third addition frequency corresponding to the compressor at the current control layer temperature; The basic frequency, the first additive frequency, the second additive frequency, and the third additive frequency are added together to obtain a total control frequency of the compressor, and the compressor is controlled to operate with the total control frequency.

6. The thermal management control method for a household photovoltaic system according to claim 5, characterized in that: The step of controlling the heat pump assembly to adjust the temperature of the photovoltaic panel layer, the battery layer and the controller inverter layer according to the current ambient temperature, the current photovoltaic panel temperature, the current battery layer temperature and the current control layer temperature also includes: Acquire a first opening of the electronic expansion valve corresponding to the first heat exchanger interlayer at the current ambient temperature and the current photovoltaic panel temperature, perform open-loop control on the opening of the electronic expansion valve corresponding to the first heat exchanger interlayer according to the first opening, and after a first preset open-loop control period, control the opening of the electronic expansion valve corresponding to the first heat exchanger interlayer with a first preset closed-loop control logic; Obtaining a second opening of the electronic expansion valve corresponding to the second heat exchanger interlayer at the current ambient temperature and the current battery layer temperature, open-loop controlling the opening of the electronic expansion valve corresponding to the second heat exchanger interlayer according to the second opening, and after a second preset open-loop control period, controlling the opening of the electronic expansion valve corresponding to the second heat exchanger interlayer with a second preset closed-loop control logic; Obtain the third opening of the electronic expansion valve corresponding to the third heat exchanger interlayer under the current ambient temperature and the current control layer temperature, open-loop control the opening of the electronic expansion valve corresponding to the third heat exchanger interlayer according to the third opening, and after the open-loop control is performed for a third preset time, control the opening of the electronic expansion valve corresponding to the third heat exchanger interlayer with a third preset closed-loop control logic.

7. The thermal management control method of a household photovoltaic system according to claim 6, characterized in that: The first preset closed-loop control logic includes: dynamically adjusting the opening of the electronic expansion valve corresponding to the first heat exchanger interlayer so that the current photovoltaic panel temperature is within a first preset temperature range; and / or The second preset closed-loop control logic includes: dynamically adjusting the opening of the electronic expansion valve corresponding to the second heat exchanger interlayer so that the current battery layer temperature is within a second preset temperature range; and / or The third preset closed-loop control logic includes: dynamically adjusting the opening of the electronic expansion valve corresponding to the third heat exchanger interlayer so that the current control layer temperature is within a third preset temperature range.

8. The thermal management control method for a household photovoltaic system according to claim 5, characterized in that: The battery layer is provided with a first fan and a second fan, the first fan is located at the top of the battery layer, and the second fan is located at the bottom of the battery layer; the controller inverter layer is provided with a third fan, and the third fan is located at the bottom of the controller inverter layer; The step of controlling the heat pump assembly to adjust the temperature of the photovoltaic panel layer, the battery layer and the controller inverter layer according to the current ambient temperature, the current photovoltaic panel temperature, the current battery layer temperature and the current control layer temperature also includes: Acquire a first rotation speed of the first fan and a second rotation speed of the second fan at the current ambient temperature and the current battery layer temperature, control the first fan according to the first rotation speed, and control the second fan according to the second rotation speed; Acquire a third rotational speed of the third fan under the current ambient temperature and the current control layer temperature, and control the third fan according to the third rotational speed.

9. The thermal management control method for a household photovoltaic system according to claim 5, characterized in that: The heat pump layer is provided with a fourth temperature sensor for detecting the exhaust temperature of the compressor; The step of controlling the heat pump assembly to adjust the temperature of the photovoltaic panel layer, the battery layer, and the controller inverter layer according to the current ambient temperature, the current photovoltaic panel temperature, the current battery layer temperature, and the current control layer temperature also includes: When the total control frequency of the compressor is greater than the preset frequency, if the exhaust temperature is less than the first preset exhaust temperature, all opened electronic expansion valves are controlled to gradually decrease the opening at the first preset opening until the exhaust temperature is greater than the second preset exhaust temperature, wherein the second preset exhaust temperature is greater than the first preset exhaust temperature; When the compressor is running, if the exhaust temperature is greater than the third preset exhaust temperature, all opened electronic expansion valves are controlled to gradually increase the opening with the second preset opening until the exhaust temperature is less than the fourth preset exhaust temperature, wherein the third preset exhaust temperature is greater than the second preset exhaust temperature, and the fourth preset exhaust temperature is less than the third preset exhaust temperature.

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