Heat pump system and control method thereof

Abstract

The invention relates to the technical field of heat pumps, in particular to a heat pump system, and aims to solve the problem that a heat pump system in the prior art cannot give consideration to a heating function while defrosting. To this end, the heat pump system of the present invention comprises: a compressor provided with an air inlet and an air outlet; the first heat exchanger comprises a first heat exchange passage structure and a second heat exchange passage structure which can exchange heat with each other; the two ends of the main loop communicate with the exhaust port and the air inlet correspondingly, and the second heat exchange channel structure, the first throttling element and the solar heat collector are sequentially arranged on the main loop; the two ends of the first branch communicate with the exhaust port and the portion, between the second heat exchange channel structure and the first throttling element, of the main loop correspondingly, and the second heat exchanger is arranged on the first branch. A high-temperature and high-pressure refrigerant discharged by the compressor is divided into two parts which are used for heating and defrosting respectively, the condensed refrigerant is evaporated through the solar heat collector by utilizing solar energy, and the functions of heating and defrosting are considered.

Description

Technical Field

[0001] The present invention relates to the technical field of heat pumps, and in particular provides a heat pump system and a control method thereof. Background Art

[0002] Air source heat pump is an energy-saving device that uses high-level energy to make heat flow from low-level heat source air to high-level heat source. It has many advantages such as energy saving, environmental protection, great flexibility, and easy management. Solar energy is an inexhaustible clean energy. Using solar energy on air source heat pumps can construct a more energy-saving and efficient heat pump system. When air source heat pumps are running in winter, there is a problem of frost on the outdoor heat exchanger. The formation of frost increases the thermal resistance of the heat exchanger surface and the resistance of air flowing through the heat exchanger, thereby reducing the heat transfer coefficient of the outdoor heat exchanger and reducing the working efficiency of the heat pump system.

[0003] Existing heat pump systems usually use reverse cycle defrosting when defrosting, that is, by changing the flow direction of the refrigerant, the high-temperature and high-pressure refrigerant discharged from the compressor directly enters the outdoor heat exchanger to condense and release heat, and the heat is used to melt the frost layer on the outdoor heat exchanger. This defrosting method has problems such as long defrosting time and high compressor energy consumption. Although the above problems have been improved after the introduction of solar energy, there is still the problem that defrosting cannot take into account the heating function at the same time.

[0004] Accordingly, the art needs a new heat pump system and a control method thereof to solve the above problems. Summary of the invention

[0005] The present invention aims to solve the above technical problem, that is, to solve the problem that the heat pump system in the prior art cannot have both the defrosting and heating functions.

[0006] In a first aspect, the present invention provides a heat pump system, which includes: a compressor, which is provided with an air inlet and an exhaust port; a first heat exchanger, which includes a first heat exchange path structure and a second heat exchange path structure that can exchange heat with each other; a second heat exchanger; a solar collector; a first throttling element; a main circuit, a first end of the main circuit is connected to the exhaust port, and a second end of the main circuit is connected to the air inlet, and the second heat exchange path structure, the first throttling element, and the solar collector are arranged on the main circuit in sequence from the first end of the main circuit to the second end of the main circuit; a first branch, a first end of the first branch is connected to the exhaust port, and a second end of the first branch is connected to the main circuit between the second heat exchange path structure and the first throttling element, and the second heat exchanger is arranged on the first branch.

[0007] In the case of adopting the above technical solution, when defrosting treatment is required for the second heat exchanger, a part of the high-temperature and high-pressure refrigerant discharged from the exhaust port of the compressor enters the main circuit, passes through the second heat exchange passage structure, exchanges heat with water or other fluids in the first heat exchange passage structure to achieve the heating function. The refrigerant condensed in the second heat exchange passage structure enters the solar collector after throttling by the first throttling element, and the refrigerant is evaporated by using solar energy. The evaporated refrigerant returns to the compressor from the intake port, and another part of the high-temperature and high-pressure refrigerant discharged from the exhaust port of the compressor enters the first branch, condenses and dissipates heat through the second heat exchanger for defrosting, and the condensed refrigerant enters the main circuit, enters the solar collector after throttling by the first throttling element, is evaporated and then returns to the compressor. Through the above heat pump system, the high-temperature and high-pressure refrigerant discharged from the compressor is divided into two parts for heating and defrosting respectively, and the solar collector is used to evaporate the condensed refrigerant by using solar energy, taking into account both the heating and defrosting functions, while also reducing the energy consumption of the compressor and improving the heating and defrosting efficiency.

[0008] In the specific implementation manner of the above heat pump system, the heat pump system further includes: a second branch, the first end of the second branch is connected to the main circuit between the second heat exchange passage structure and the first throttling element, and the second end of the second branch is connected to the first branch between the first end of the first branch and the second heat exchanger; a third branch, the first end of the third branch is connected to the first branch between the second heat exchanger and the second end of the first branch, and the second end of the third branch is connected to the main circuit between the solar collector and the second end of the main circuit; a second throttling element, the second throttling element is arranged on the second branch; a first on-off valve, the first on-off valve is arranged on the first branch between the first end of the first branch and the second heat exchanger; a second on-off valve, the second on-off valve is arranged on the third branch; a third on-off valve, the third on-off valve is arranged on the first branch between the first end of the third branch and the second end of the first branch; a fourth on-off valve, the fourth on-off valve is arranged on the main circuit between the solar collector and the second end of the third branch.

[0009] In the case of adopting the above technical solution, by adding the second branch, the third branch, the second throttling element and each on-off valve, the opening and closing of each on-off valve can be controlled according to the light condition and whether defrosting is required to obtain different refrigerant passages, so that the heat pump system can minimize energy consumption on the premise of meeting the use requirements.

[0010] In the specific implementation manner of the above heat pump system, the heat pump system further includes: a gas-liquid separator, the gas-liquid separator is arranged on the main circuit between the second end of the third branch and the second end of the main circuit.

[0011] In the case of adopting the above technical solution, the refrigerant about to return to the compressor is subjected to gas-liquid separation treatment by the gas-liquid separator, ensuring that the separated gaseous refrigerant returns to the compressor, thereby protecting the compressor and avoiding liquid slugging.

[0012] In the specific implementation manner of the above heat pump system, the heat pump system further includes: a four-way valve, the four-way valve includes a first port, a second port, a third port, and a fourth port, the first port and the second port are arranged on the main circuit between the first end of the main circuit and the second heat exchange path structure, and the third port and the fourth port are arranged on the main circuit between the second end of the third branch and the gas-liquid separator.

[0013] In the case of adopting the above technical solution, by setting the four-way valve, the flow direction of the refrigerant in the heat pump system can be controlled, thereby meeting different usage requirements such as refrigeration, heating, and defrosting.

[0014] In the specific implementation manner of the above heat pump system, the first throttling element is a first electronic expansion valve, and the second throttling element is a second electronic expansion valve.

[0015] In the case of adopting the above technical solution, using electronic expansion valves enables the first throttling element and the second throttling element to throttle and depressurize the refrigerant while also regulating the flow rate of the refrigerant. In addition, the on / off of the corresponding passages can also be controlled by controlling the electronic expansion valves.

[0016] In the specific implementation manner of the above heat pump system, the first on / off valve is a first solenoid valve, the second on / off valve is a second solenoid valve, the third on / off valve is a third solenoid valve, and the fourth on / off valve is a fourth solenoid valve.

[0017] In the case of adopting the above technical solution, using solenoid valves can achieve precise automatic control compared to other on / off valves.

[0018] In a second aspect, the present invention further provides a control method for a heat pump system, the control method is used to control the heat pump system; the heat pump system further includes: a temperature sensor for detecting the coil temperature value of the second heat exchanger; a light sensor for detecting the light intensity value at the solar collector; the control method includes: in the heating mode, obtaining the coil temperature value; obtaining the light intensity value; based on the coil temperature value and the light intensity value, controlling the opening and closing of the first on / off valve, the second on / off valve, the third on / off valve, the fourth on / off valve, the first electronic expansion valve, and the second electronic expansion valve.

[0019] In the case of adopting the above technical solution, it is possible to determine whether defrosting treatment needs to be carried out on the second heat exchanger according to the coil temperature value, and determine whether the solar collector can be used to heat the refrigerant according to the light intensity value. By combining the coil temperature value and the light intensity value, the opening and closing of each on-off valve and solenoid valve are controlled to obtain different refrigerant paths, so that the heat pump system can minimize energy consumption as much as possible on the premise of meeting the usage requirements.

[0020] In the specific implementation manner of the control method of the above heat pump system, the step of "controlling the opening and closing of the first on-off valve, the second on-off valve, the third on-off valve, the fourth on-off valve, the first electronic expansion valve and the second electronic expansion valve based on the coil temperature value and the light intensity value" further includes: if the coil temperature value is less than or equal to a preset temperature threshold and the light intensity value is greater than or equal to a preset light threshold, then control the first solenoid valve, the third solenoid valve, the fourth solenoid valve and the first electronic expansion valve to open, and control the second solenoid valve and the second electronic expansion valve to close.

[0021] In the case of adopting the above technical solution, when the coil temperature value is less than or equal to the temperature threshold, defrosting treatment needs to be carried out on the second heat exchanger. When the light intensity value is greater than or equal to the light threshold, the solar collector can be used to heat the refrigerant. Therefore, control the first solenoid valve, the third solenoid valve, the fourth solenoid valve and the first electronic expansion valve to open, and control the second solenoid valve and the second electronic expansion valve to close, so as to divide the high-temperature and high-pressure refrigerant discharged from the compressor into two parts for heating and defrosting respectively, and use the solar energy of the solar collector to evaporate the condensed refrigerant, taking into account both the heating and defrosting functions, while also reducing the energy consumption of the compressor and improving the heating and defrosting efficiency.

[0022] In the specific implementation manner of the control method of the above heat pump system, the step of "controlling the opening and closing of the first on-off valve, the second on-off valve, the third on-off valve, the fourth on-off valve, the first electronic expansion valve and the second electronic expansion valve based on the coil temperature value and the light intensity value" further includes: if the coil temperature value is greater than the temperature threshold and the light intensity value is greater than or equal to the light threshold, then control the second solenoid valve, the fourth solenoid valve, the first electronic expansion valve and the second electronic expansion valve to open, and control the first solenoid valve and the third solenoid valve to close.

[0023] In the case of adopting the above technical solution, when the coil temperature value is greater than the temperature threshold, defrosting treatment of the second heat exchanger is not required. When the light intensity value is greater than or equal to the light threshold, the solar collector can be used to heat the refrigerant. Therefore, the second solenoid valve, the fourth solenoid valve, the first electronic expansion valve, and the second electronic expansion valve are controlled to open, and the first solenoid valve and the third solenoid valve are controlled to close. The high-temperature and high-pressure refrigerant discharged from the compressor first enters the second heat exchange path structure and exchanges heat with the water or other fluid in the first heat exchange path structure to achieve the heating function. The refrigerant condensed in the second heat exchange path structure is divided into two parts, and the refrigerant is evaporated by the second heat exchanger and the solar collector respectively, and then returns to the compressor, reducing the energy consumption of the compressor and improving the heating efficiency of the heat pump system.

[0024] In the specific implementation manner of the control method of the above heat pump system, the step of "controlling the opening and closing of the first on-off valve, the second on-off valve, the third on-off valve, the fourth on-off valve, the first electronic expansion valve, and the second electronic expansion valve based on the coil temperature value and the light intensity value" further includes: if the coil temperature value is greater than the temperature threshold and the light intensity value is less than the light threshold, control the second solenoid valve and the second electronic expansion valve to open, and control the first solenoid valve, the third solenoid valve, the fourth solenoid valve, and the first electronic expansion valve to close.

[0025] In the case of adopting the above technical solution, when the coil temperature value is greater than the temperature threshold, defrosting treatment of the second heat exchanger is not required. When the light intensity value is less than the light threshold, it is not suitable to use the solar collector to heat the refrigerant. Therefore, the second solenoid valve and the second electronic expansion valve are controlled to open, and the first solenoid valve, the third solenoid valve, the fourth solenoid valve, and the first electronic expansion valve are controlled to close. The high-temperature and high-pressure refrigerant discharged from the compressor first enters the second heat exchange path structure and exchanges heat with the water or other fluid in the first heat exchange path structure to achieve the heating function. The refrigerant condensed in the second heat exchange path structure enters the second heat exchanger for evaporation and then returns to the compressor, ensuring the heating effect of the heat pump system when the light intensity is small.

[0026] Compared with the prior art, the beneficial effects of the heat pump system provided by the present invention are as follows: by dividing the high-temperature and high-pressure refrigerant discharged from the compressor into two parts, heating and defrosting are carried out respectively, and the solar collector is used to utilize solar energy to evaporate the condensed refrigerant, taking into account both the heating and defrosting functions, while also reducing the energy consumption of the compressor and improving the heating and defrosting efficiency. The control method of the heat pump system provided by the present invention is used to control the heat pump system. Description of the Drawings

[0027] The following describes the preferred embodiments of the present invention with reference to the drawings, in which:

[0028] Figure 1 is a schematic structural diagram of the first embodiment of the heat pump system of the present invention;

[0029] Figure 2 is a schematic structural diagram of the second embodiment of the heat pump system of the present invention;

[0030] Figure 3 is a main step flowchart of the control method of the heat pump system of the present invention;

[0031] Figure 4 is a schematic structural diagram of a usage state of the heat pump system of the present invention;

[0032] Figure 5 is a schematic structural diagram of another usage state of the heat pump system of the present invention.

[0033] Reference numerals:

[0034] 1 - Compressor, 2 - First heat exchanger, 3 - Second heat exchanger, 4 - Solar collector, 5 - First throttling element, 6 - Main circuit, 7 - First branch, 8 - Gas-liquid separator, 9 - Four-way valve, 11 - Intake port, 12 - Exhaust port, 91 - First port, 92 - Second port, 93 - Third port, 94 - Fourth port, 101 - Second branch, 102 - Third branch, 103 - Second throttling element, 104 - First on-off valve, 105 - Second on-off valve, 106 - Third on-off valve, 107 - Fourth on-off valve. Detailed implementation manners

[0035] The following describes some embodiments of the present invention with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are only used to explain the technical principle of the present invention and are not used to limit the protection scope of the present invention. Those skilled in the art can make adjustments according to needs to adapt to specific application scenarios.

[0036] It should be noted that in the description of the present invention, ordinal numbers such as "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. In addition, in the description of the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", and "coupled" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and can also be the communication inside two elements. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0037] In addition, it should be noted that in the description of the present invention, although the various steps of the control method of the present invention are described in this application in a specific order, these orders are not restrictive. Without departing from the basic principles of the present invention, those skilled in the art can perform the steps in a different order.

[0038] Based on the problem pointed out in the background technology that the heat pump system in the prior art cannot take into account the heating function while defrosting, the purpose is to divide the high-temperature and high-pressure refrigerant discharged from the compressor into two parts, respectively performing heating and defrosting, and using solar energy through a solar collector to evaporate the condensed refrigerant, taking into account the heating and defrosting functions, while also reducing the energy consumption of the compressor and improving the efficiency of heating and defrosting.

[0039] See first Figure 1 , Figure 1 FIG. 1 is a schematic structural diagram of a first embodiment of a heat pump system of the present invention. Figure 1 As shown, the heat pump system of the present invention includes a compressor 1, a first heat exchanger 2, a second heat exchanger 3, a solar collector 4 and a first throttling element 5; the compressor 1 is provided with an air inlet 11 and an exhaust port 12; the first heat exchanger 2 includes a first heat exchange path structure and a second heat exchange path structure capable of exchanging heat with each other; the second heat exchanger 3 can be arranged outdoors, and is used to realize heat exchange between the refrigerant in the second heat exchanger 3 and the outdoor air; the solar collector 4 is arranged at a position where solar energy can be collected, such as an unobstructed outdoor area, and is used to collect solar radiation energy, and convert the solar radiation energy into heat energy, and transfer the heat energy to the refrigerant flowing through the solar collector 4, so as to realize heating and evaporation of the refrigerant; the first throttling element 5 is used to throttle and reduce the pressure of the refrigerant. The heat pump system also includes a main loop 6 and a first branch 7. The first end of the main loop 6 is connected to the exhaust port 12, and the second end of the main loop 6 is connected to the air inlet 11. The second heat exchange path structure, the first throttling element 5, and the solar collector 4 are arranged on the main loop 6 in sequence from the first end of the main loop 6 to the second end of the main loop 6; the first end of the first branch 7 is connected to the exhaust port 12, and the second end of the first branch 7 is connected to the main loop 6 between the second heat exchange path structure and the first throttling element 5, and the second heat exchanger 3 is arranged on the first branch 7.

[0040] When defrosting treatment is required for the second heat exchanger 3, a part of the high-temperature and high-pressure refrigerant discharged from the exhaust port 12 of the compressor 1 enters the main circuit 6. After passing through the second heat exchange passage structure, it exchanges heat with the water or other fluid in the first heat exchange passage structure to achieve the heating function. The refrigerant condensed in the second heat exchange passage structure enters the solar collector 4 after throttling by the first throttling element 5, and the solar energy is used to evaporate the refrigerant. The evaporated refrigerant returns to the compressor 1 from the intake port 11. Another part of the high-temperature and high-pressure refrigerant discharged from the exhaust port 12 of the compressor 1 enters the first branch 7, condenses and dissipates heat through the second heat exchanger 3 for defrosting. The condensed refrigerant enters the main circuit 6, enters the solar collector 4 after throttling by the first throttling element 5, evaporates and then returns to the compressor 1. Through the above heat pump system, the high-temperature and high-pressure refrigerant discharged from the compressor 1 is divided into two parts, which are used for heating and defrosting respectively. The solar collector 4 is used to evaporate the condensed refrigerant by using solar energy, taking into account both the heating and defrosting functions. At the same time, the energy consumption of the compressor 1 is reduced, and the heating and defrosting efficiency is improved.

[0041] It should be noted that water or other fluid to be heated can be introduced into the first heat exchange passage structure, and the refrigerant flows in the second heat exchange passage structure to exchange heat with the water or other fluid in the first heat exchange passage structure to achieve the heating treatment of the water or other fluid.

[0042] It should also be noted that the first throttling element 5 can be a throttle valve, an electronic expansion valve, a Venturi tube, etc., as long as it can throttle and depressurize the refrigerant.

[0043] Continue to refer to Figure 1 , the heat pump system further includes a gas-liquid separator 8 and a four-way valve 9; the gas-liquid separator 8 is arranged on the main circuit 6 between the solar collector 4 and the second end of the main circuit 6. The gas-liquid separation treatment of the refrigerant about to return to the compressor 1 is carried out through the gas-liquid separator 8 to ensure that the separated gaseous refrigerant returns to the compressor 1, thereby protecting the compressor 1 and avoiding liquid hammer; the four-way valve 9 includes a first port 91, a second port 92, a third port 93 and a fourth port 94. The first port 91 and the second port 92 are arranged on the main circuit 6 between the first end of the main circuit 6 and the second heat exchange passage structure, and the third port 93 and the fourth port 94 are arranged on the main circuit 6 between the solar collector 4 and the gas-liquid separator 8. Through the setting of the four-way valve 9, the flow direction of the refrigerant in the heat pump system can be controlled, so as to meet different usage requirements such as refrigeration, heating and defrosting.

[0044] It should be noted that in the heating mode, the first port 91 and the second port 92 of the four-way valve 9 are controlled to be connected, and the third port 93 and the fourth port 94 are connected. In the refrigeration mode, the first port 91 and the fourth port 94 of the four-way valve 9 are controlled to be connected, and the second port 92 and the third port 93 are connected.

[0045] Those skilled in the art can understand that, although it is described above in combination with Figure 1 that the heat pump system includes a four-way valve 9, this is not restrictive. In the case where only heating or cooling is required, the heat pump system may not be provided with the four-way valve 9. In addition, although it is described above in combination with Figure 1 that the heat pump system includes a gas-liquid separator 8, this is also not restrictive. The gas-liquid separator 8 may not be provided, or the gas-liquid separator 8 may be replaced with an evaporation drying element such as a flash evaporator, all without departing from the principle of the present invention and all falling within the protection scope of the present invention.

[0046] Refer to the following Figure 2 , Figure 2 which is a schematic structural diagram of the second embodiment of the heat pump system of the present invention. As Figure 2 shown, as a possible embodiment, on the basis of the first embodiment shown in Figure 1 , the heat pump system of the present invention further includes a second branch 101, a third branch 102, a second throttling element 103, a first on-off valve 104, a second on-off valve 105, a third on-off valve 106, and a fourth on-off valve 107. The first end of the second branch 101 is connected to the main circuit 6 between the second heat exchange path structure and the first throttling element 5, and the second end of the second branch 101 is connected to the first branch 7 between the first end of the first branch 7 and the second heat exchanger 3; the first end of the third branch 102 is connected to the first branch 7 between the second heat exchanger 3 and the second end of the first branch 7, and the second end of the third branch 102 is connected to the main circuit 6 between the solar collector 4 and the second end of the main circuit 6; the second throttling element 103 is provided on the second branch 101; the first on-off valve 104 is provided on the first branch 7 between the first end of the first branch 7 and the second heat exchanger 3; the second on-off valve 105 is provided on the third branch 102; the third on-off valve 106 is provided on the first branch 7 between the first end of the third branch 102 and the second end of the first branch 7; the fourth on-off valve 107 is provided on the main circuit 6 between the solar collector 4 and the second end of the third branch 102; the gas-liquid separator 8 is provided on the main circuit 6 between the second end of the third branch 102 and the second end of the main circuit 6, and the third port 93 and the fourth port 94 are provided on the main circuit 6 between the second end of the third branch 102 and the gas-liquid separator 8.

[0047] By adding the second branch 101, the third branch 102, the second throttling element 103, and each on-off valve, the opening and closing of each on-off valve can be controlled according to the light condition and whether defrosting is required, so as to obtain different refrigerant paths, enabling the heat pump system to minimize energy consumption as much as possible on the premise of meeting the use requirements.

[0048] Optionally, the first throttling element 5 is a first electronic expansion valve, and the second throttling element 103 is a second electronic expansion valve, so that the first throttling element 5 and the second throttling element 103 can throttle and depressurize the refrigerant while also adjusting the flow rate of the refrigerant. In addition, the on-off of the corresponding passage can be controlled by controlling the electronic expansion valve; the first on-off valve 104 is a first solenoid valve, the second on-off valve 105 is a second solenoid valve, the third on-off valve 106 is a third solenoid valve, and the fourth on-off valve 107 is a fourth solenoid valve, which can achieve precise automatic control. The first on-off valve 104, the second on-off valve 105, the third on-off valve 106, and the fourth on-off valve 107 can also be other on-off valves such as pneumatic valves or electric valves.

[0049] The heat pump system further includes a temperature sensor and a light sensor. The temperature sensor is used to detect the coil temperature value of the second heat exchanger 3, and the temperature sensor can be arranged on the coil of the second heat exchanger 3; the light sensor is used to detect the light intensity value at the solar collector 4, and the light sensor can be arranged on the housing of the solar collector 4.

[0050] Then refer to Figure 3 , which shows the main steps of the control method of the heat pump system of the present invention, specifically including the following steps:

[0051] Step S100: In the heating mode, obtain the coil temperature value.

[0052] Step S101: Obtain the light intensity value.

[0053] Step S102: Based on the coil temperature value and the light intensity value, control the opening and closing of the first on-off valve, the second on-off valve, the third on-off valve, the fourth on-off valve, the first electronic expansion valve, and the second electronic expansion valve.

[0054] Through the above control method, it is possible to judge whether defrosting treatment is required for the second heat exchanger according to the coil temperature value, judge whether the solar collector can be used to heat the refrigerant according to the light intensity value, and combine the coil temperature value and the light intensity value to control the opening and closing of each on-off valve and electronic valve to obtain different refrigerant passages, so that the heat pump system can minimize energy consumption on the premise of meeting the usage requirements.

[0055] It should be noted that, although the order of the two steps of "obtaining the coil temperature value" and "obtaining the light intensity value" is described above as "obtaining the coil temperature value" first and "obtaining the light intensity value" second in combination with Figure 3 , this is not restrictive. It is also possible to have "obtaining the light intensity value" first and "obtaining the coil temperature value" second. Those skilled in the art can execute them in different orders according to needs.

[0056] Specifically, since it is in the heating mode, the first port and the second port of the four-way valve are controlled to be connected, and the third port and the fourth port are connected. If the coil temperature value is less than or equal to the preset temperature threshold and the light intensity value is greater than or equal to the preset light threshold, the first solenoid valve, the third solenoid valve, the fourth solenoid valve, and the first electronic expansion valve are controlled to open, and the second solenoid valve and the second electronic expansion valve are controlled to close. At this time, the specific passage structure of the heat pump system is as shown in Figure 1 shown. When the coil temperature value is less than or equal to the temperature threshold, defrosting treatment needs to be carried out on the second heat exchanger. When the light intensity value is greater than or equal to the light threshold, the solar collector can be used to heat the refrigerant. Therefore, the first solenoid valve, the third solenoid valve, the fourth solenoid valve, and the first electronic expansion valve are controlled to open, and the second solenoid valve and the second electronic expansion valve are controlled to close. The high-temperature and high-pressure refrigerant discharged from the compressor is divided into two parts for heating and defrosting respectively, and the solar collector is used to evaporate the condensed refrigerant by using solar energy, which takes into account both the heating and defrosting functions, reduces the energy consumption of the compressor, and improves the heating and defrosting efficiency.

[0057] If the coil temperature value is greater than the temperature threshold and the light intensity value is greater than or equal to the light threshold, the second solenoid valve, the fourth solenoid valve, the first electronic expansion valve, and the second electronic expansion valve are controlled to open, and the first solenoid valve and the third solenoid valve are controlled to close. At this time, the specific passage structure of the heat pump system is as shown in Figure 4 shown. When the coil temperature value is greater than the temperature threshold, defrosting treatment is not required for the second heat exchanger. When the light intensity value is greater than or equal to the light threshold, the solar collector can be used to heat the refrigerant. Therefore, the second solenoid valve, the fourth solenoid valve, the first electronic expansion valve, and the second electronic expansion valve are controlled to open, and the first solenoid valve and the third solenoid valve are controlled to close. The high-temperature and high-pressure refrigerant discharged from the compressor first enters the second heat exchange passage structure to exchange heat with water or other fluids in the first heat exchange passage structure to achieve the heating function. The refrigerant condensed in the second heat exchange passage structure is divided into two parts, and the refrigerant is evaporated by the second heat exchanger and the solar collector respectively. After being separated by the gas-liquid separator, the gaseous refrigerant returns to the compressor, reducing the energy consumption of the compressor and improving the heating efficiency of the heat pump system.

[0058] If the coil temperature value is greater than the temperature threshold and the light intensity value is less than the light threshold, the second solenoid valve and the second electronic expansion valve are controlled to open, and the first solenoid valve, the third solenoid valve, the fourth solenoid valve, and the first electronic expansion valve are controlled to close. At this time, the specific passage structure of the heat pump system is as shown in Figure 5As shown in the figure. When the temperature value of the coil is greater than the temperature threshold, there is no need to defrost the second heat exchanger. When the light intensity value is less than the light threshold, it is not suitable to use the solar collector to heat the refrigerant. Therefore, the second solenoid valve and the second electronic expansion valve are controlled to open, and the first solenoid valve, the third solenoid valve, the fourth solenoid valve and the first electronic expansion valve are controlled to close. The high-temperature and high-pressure refrigerant discharged from the compressor first enters the second heat exchange path structure and exchanges heat with the water or other fluids in the first heat exchange path structure to achieve the heating function. The refrigerant condensed in the second heat exchange path structure enters the second heat exchanger for evaporation, and then after being separated by the gas-liquid separator, the gaseous refrigerant returns to the compressor, ensuring the heating effect of the heat pump system when the light intensity is low.

[0059] It should be noted that the "temperature threshold" is a preset value that can reflect whether the coil of the second heat exchanger needs to be defrosted. When the temperature value of the coil is less than or equal to the preset temperature threshold, it is necessary to defrost the second heat exchanger. The specific value of the temperature threshold can be set to different values according to the usage requirements. Exemplarily, the temperature threshold can be set in the range of -3 to 0 °C. In addition, the "light threshold" is a value that can reflect whether the solar collector can be used to heat the refrigerant. When the light intensity value is greater than or equal to the light threshold, the thermal energy converted from the solar radiation energy collected by the solar collector can effectively heat the refrigerant. The specific value of the light threshold can be set to different values according to the usage requirements. Exemplarily, the light threshold can be set in the range of 600 to 1000 W / m 2 range. The present invention does not specifically limit the specific values of the temperature threshold and the light threshold.

[0060] As a possible implementation manner, in the heating mode, if the temperature value of the coil is less than or equal to the temperature threshold and the light intensity value is less than the light threshold, then the first port and the fourth port of the four-way valve are controlled to communicate, and the second port and the third port are controlled to communicate. The second solenoid valve and the second electronic expansion valve are controlled to open, and the first solenoid valve, the third solenoid valve, the fourth solenoid valve and the first electronic expansion valve are controlled to close. At this time, the specific path structure of the heat pump system is as Figure 5As shown; when the coil temperature value is greater than the temperature threshold, control the first port and the second port of the four-way valve to be connected, and the third port and the fourth port to be connected. When the coil temperature value is less than or equal to the temperature threshold, defrosting treatment needs to be carried out on the second heat exchanger. When the light intensity value is less than the light threshold, it is not suitable to use the solar collector to heat the refrigerant. Therefore, control the first port and the fourth port of the four-way valve to be connected, and the second port and the third port to be connected. The high-temperature and high-pressure refrigerant discharged from the compressor first enters the second heat exchanger for condensation and heat dissipation for defrosting. After the condensed refrigerant passes through the second electronic expansion valve for throttling, it enters the second heat exchange path structure to absorb heat and evaporate. After being separated by the gas-liquid separator, the gaseous refrigerant returns to the compressor; when the coil temperature value is greater than the temperature threshold, defrosting treatment on the second heat exchanger can be stopped. Therefore, control the first port and the second port of the four-way valve to be connected, and the third port and the fourth port to be connected for heating; through the above control method, the defrosting effect of the heat pump system is ensured when the light intensity is small.

[0061] As another possible implementation manner, in the refrigeration mode, control the first port and the fourth port of the four-way valve to be connected, and the second port and the third port to be connected. Control the second solenoid valve and the second electronic expansion valve to be opened, and control the first solenoid valve, the third solenoid valve, the fourth solenoid valve and the first electronic expansion valve to be closed. At this time, the specific path structure of the heat pump system is as Figure 5 shown. The high-temperature and high-pressure refrigerant discharged from the compressor first enters the second heat exchanger for condensation and heat dissipation. After the condensed refrigerant passes through the second electronic expansion valve for throttling, it enters the second heat exchange path structure to absorb heat and evaporate. The water or other fluid in the first heat exchange path structure is cooled due to the heat absorption of the refrigerant, realizing the refrigeration function. After the refrigerant evaporated in the second heat exchange path structure is separated by the gas-liquid separator, the gaseous refrigerant returns to the compressor, ensuring the refrigeration effect of the heat pump system.

[0062] It should be noted that the above implementation manners are only used to illustrate the principle of the present invention and are not intended to limit the protection scope of the present invention. Without departing from the principle of the present invention, those skilled in the art can adjust the above implementation manners so that the present invention can be applied to more specific application scenarios.

[0063] So far, the technical solution of the present invention has been described in combination with the preferred implementation manners shown in the drawings. However, it is easy for those skilled in the art to understand that the protection scope of the present invention is obviously not limited to these specific implementation manners. Without departing from the principle of the present invention, those skilled in the art can make equivalent changes or replacements to the relevant technical features, and the technical solutions after these changes or replacements will fall within the protection scope of the present invention.

Claims

1. A heat pump system, characterized in that, the heat pump system comprises: a compressor, which is provided with an air inlet and an air outlet; a first heat exchanger, which comprises a first heat exchange passage structure and a second heat exchange passage structure capable of heat exchange with each other; a second heat exchanger; a solar collector; a first throttling element; a main circuit, the first end of the main circuit is communicated with the air outlet, the second end of the main circuit is communicated with the air inlet, and the second heat exchange passage structure, the first throttling element, and the solar collector are sequentially arranged on the main circuit from the first end of the main circuit to the second end of the main circuit; a first branch, the first end of the first branch is communicated with the air outlet, the second end of the first branch is connected to the main circuit between the second heat exchange passage structure and the first throttling element, and the second heat exchanger is arranged on the first branch.

2. The heat pump system according to claim 1, characterized in that, the heat pump system further comprises: a second branch, the first end of the second branch is connected to the main circuit between the second heat exchange passage structure and the first throttling element, and the second end of the second branch is connected to the first branch between the first end of the first branch and the second heat exchanger; a third branch, the first end of the third branch is connected to the first branch between the second heat exchanger and the second end of the first branch, and the second end of the third branch is connected to the main circuit between the solar collector and the second end of the main circuit; a second throttling element, which is arranged on the second branch; a first on-off valve, which is arranged on the first branch between the first end of the first branch and the second heat exchanger; a second on-off valve, which is arranged on the third branch; a third on-off valve, which is arranged on the first branch between the first end of the third branch and the second end of the first branch; a fourth on-off valve, which is arranged on the main circuit between the solar collector and the second end of the third branch.

3. The heat pump system according to claim 2, characterized in that, the heat pump system further comprises: a gas-liquid separator, which is arranged on the main circuit between the second end of the third branch and the second end of the main circuit.

4. The heat pump system according to claim 3, characterized in that, the heat pump system further comprises: a four-way valve, which comprises a first port, a second port, a third port and a fourth port, the first port and the second port are arranged on the main circuit between the first end of the main circuit and the second heat exchange passage structure, and the third port and the fourth port are arranged on the main circuit between the second end of the third branch and the gas-liquid separator.

5. The heat pump system according to claim 4, characterized in that, the first throttling element is a first electronic expansion valve, and the second throttling element is a second electronic expansion valve.

6. The heat pump system according to claim 5, characterized in that, The first on-off valve is a first solenoid valve, the second on-off valve is a second solenoid valve, the third on-off valve is a third solenoid valve, and the fourth on-off valve is a fourth solenoid valve.

7. A control method for a heat pump system, characterized in that, The control method is used to control the heat pump system according to claim 6; The heat pump system further includes: A temperature sensor for detecting the temperature value of the coil of the second heat exchanger; A light sensor for detecting the light intensity value at the solar collector; The control method includes: In the heating mode, obtaining the temperature value of the coil; Obtaining the light intensity value; Based on the temperature value of the coil and the light intensity value, controlling the opening and closing of the first on-off valve, the second on-off valve, the third on-off valve, the fourth on-off valve, the first electronic expansion valve, and the second electronic expansion valve.

8. The control method of the heat pump system according to claim 7, wherein The step of "based on the temperature value of the coil and the light intensity value, controlling the opening and closing of the first on-off valve, the second on-off valve, the third on-off valve, the fourth on-off valve, the first electronic expansion valve, and the second electronic expansion valve" further includes: If the temperature value of the coil is less than or equal to a preset temperature threshold and the light intensity value is greater than or equal to a preset light threshold, control the first solenoid valve, the third solenoid valve, the fourth solenoid valve, and the first electronic expansion valve to open, and control the second solenoid valve and the second electronic expansion valve to close.

9. The control method of the heat pump system according to claim 8, wherein The step of "based on the temperature value of the coil and the light intensity value, controlling the opening and closing of the first on-off valve, the second on-off valve, the third on-off valve, the fourth on-off valve, the first electronic expansion valve, and the second electronic expansion valve" further includes: If the temperature value of the coil is greater than the temperature threshold and the light intensity value is greater than or equal to the light threshold, control the second solenoid valve, the fourth solenoid valve, the first electronic expansion valve, and the second electronic expansion valve to open, and control the first solenoid valve and the third solenoid valve to close.

10. The control method of the heat pump system according to claim 9, wherein The step of "based on the temperature value of the coil and the light intensity value, controlling the opening and closing of the first on-off valve, the second on-off valve, the third on-off valve, the fourth on-off valve, the first electronic expansion valve, and the second electronic expansion valve" further includes: If the temperature value of the coil is greater than the temperature threshold and the light intensity value is less than the light threshold, control the second solenoid valve and the second electronic expansion valve to open, and control the first solenoid valve, the third solenoid valve, the fourth solenoid valve, and the first electronic expansion valve to close.

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