Control method and device of heat pump system and heat pump system

Abstract

The present disclosure provides a control method of a heat pump system, a controller and a heat pump system, and relates to the technical field of energy-saving air conditioning. The heat pump system comprises a main refrigerant circulation flow path, a first refrigerant flow path, a first adjusting valve and a first throttling component. The main refrigerant circulation flow path comprises a compressor, an outdoor heat exchanger, an indoor heat exchanger and a gas-liquid separator connected in series. The first refrigerant flow path is connected in parallel with a pipe section where the outdoor heat exchanger is located, and comprises a heat collecting component and the first throttling component. The first adjusting valve is connected with the main refrigerant circulation flow path and the first refrigerant flow path respectively, and is connected with the gas-liquid separator through a second refrigerant flow path. The control method of the heat pump system comprises: in a refrigeration mode, according to at least one of the supercooling degree and the superheating degree of the heat pump system, the first adjusting valve and the first throttling component are adjusted and controlled to adjust the refrigerant amount participating in the refrigeration cycle in the heat pump system. Through the above method, the dynamic balance of the refrigerant amount participating in the refrigeration cycle in the system can be realized, and the problems such as refrigerant amount imbalance existing in the related art can be effectively solved.

Description

Technical Field

[0001] This disclosure relates to the field of energy-saving air conditioning technology, and in particular to a control method, device and heat pump system for a heat pump system. Background Technology

[0002] In energy-efficient air conditioning systems (such as dual-mode solar heat pump systems), a common architecture is the parallel connection of the refrigerant piping for the outdoor heat exchanger and the refrigerant piping for the heat collector. The heat collector is typically a photovoltaic-thermal (PVT) module or a solar thermal module. In heating mode, the heat collector acts as an auxiliary evaporator, absorbing solar radiation and air heat, thereby increasing the evaporation temperature and significantly improving the heat pump system's Coefficient of Performance (COP). However, when the heat pump system switches to cooling mode, the indoor heat exchanger changes from a condenser to an evaporator, and the outdoor heat exchanger changes from an evaporator to a condenser. If the refrigerant piping for the heat collector remains connected to the refrigerant piping for the outdoor heat exchanger, the refrigerant will ineffectively absorb heat in the refrigerant piping for the heat collector, reducing cooling efficiency and potentially causing uncontrolled suction superheat.

[0003] To address the aforementioned issues, the proposed solution is to directly close the shut-off valve on the refrigerant pipeline containing the heat collector assembly in cooling mode, thereby isolating that branch from the refrigerant circulation loop. This solution presents several problems: First, the total refrigerant charge is typically designed for heating mode. In cooling mode, the isolation of the branch containing the heat collector assembly reduces the volume of the refrigerant circulation loop, leading to an excess of refrigerant circulating within the system. Second, this excess refrigerant may cause increased condensing pressure, increased compressor power consumption, and decreased energy efficiency. Third, the proposed solution requires manual operation of the shut-off valve, resulting in poor control reliability of the heat pump system. Summary of the Invention

[0004] In order to solve at least one of the problems in the heat pump control schemes of related technologies, such as the possible refrigerant imbalance after switching from heating mode to cooling mode, this disclosure provides a control method, device and heat pump system for a heat pump system.

[0005] According to a first aspect of this disclosure, a control method for a heat pump system is provided, wherein the heat pump system includes: a main refrigerant circulation path, including a compressor, an outdoor heat exchanger, an indoor heat exchanger, and a gas-liquid separator connected in series; a first refrigerant circulation path, connected in parallel with the pipeline section of the main refrigerant circulation path where the outdoor heat exchanger is located, including a heat collection component and a first throttling component; a first regulating valve, respectively connected to the main refrigerant circulation path and the first refrigerant circulation path, and connected to the gas-liquid separator through a second refrigerant circulation path; the control method for the heat pump system includes: in a cooling mode, determining at least one of the subcooling degree and the superheat degree of the heat pump system; and adjusting the first regulating valve and the first throttling component according to at least one of the subcooling degree and the superheat degree of the heat pump system to adjust the amount of refrigerant participating in the cooling cycle in the heat pump system.

[0006] In some embodiments, regulating the first regulating valve and the first throttling component according to at least one of the subcooling and superheat of the heat pump system includes: determining the current refrigerant state according to at least one of the subcooling and superheat of the heat pump system; and, if the current refrigerant state is a first state, performing a first sub-regulation on the first regulating valve and the first throttling component to drive a portion of the refrigerant in the main refrigerant circulation path to be stored in the first refrigerant circulation path, wherein the first state is a state in which the amount of refrigerant participating in the refrigeration cycle is excessive.

[0007] In some embodiments, regulating the first regulating valve and the first throttling component according to at least one of the subcooling and superheat of the heat pump system includes: when the current refrigerant state is a second state, performing a second sub-regulation on the first regulating valve and the first throttling component to drive a portion of the refrigerant stored in the first refrigerant flow path into the main refrigerant circulation flow path, wherein the second state is a state in which the amount of refrigerant participating in the refrigeration cycle is too small.

[0008] In some embodiments, the first regulating valve is a three-way valve, with the first end of the three-way valve connected to the main refrigerant circulation path, the second end of the three-way valve connected to the second refrigerant path, and the third end of the three-way valve connected to the first refrigerant path.

[0009] In some embodiments, performing a first sub-control on the first regulating valve and the first throttling component includes: switching the three-way valve between a first conducting state and a second conducting state according to a set switching cycle, wherein the first conducting state is connecting the first and third ends of the three-way valve, and the second conducting state is connecting the second and third ends of the three-way valve; and setting the first throttling component to a first opening degree so that the first refrigerant flow path is connected to the pipe section in the main refrigerant circulation path where the indoor heat exchanger is located, wherein the first opening degree is greater than 0 and less than or equal to a first opening degree threshold.

[0010] In some embodiments, the pipeline section where the outdoor heat exchanger is located further includes a second throttling component, and the method further includes: when the current refrigerant state is a first state, reducing the opening degree of the second throttling component, and making the reduced opening degree of the second throttling component greater than or equal to a second opening degree threshold, wherein the second opening degree threshold is greater than or equal to the first opening degree threshold.

[0011] In some embodiments, the second sub-control of the first regulating valve and the first throttling component includes: setting the three-way valve to a first conducting state, wherein the first conducting state is to connect the first end and the third end of the three-way valve; increasing the opening degree of the first throttling component, and making the increased opening degree of the first throttling component less than or equal to the first opening degree threshold; and switching the refrigerant flow direction in the main refrigerant circulation path to the heating circulation direction, and making the refrigerant circulate according to the heating circulation direction for a set duration.

[0012] In some embodiments, the main refrigerant circulation path further includes a second regulating valve, and switching the refrigerant flow direction in the main refrigerant circulation path to the heating circulation direction includes: regulating the second regulating valve to switch the refrigerant flow direction in the main refrigerant circulation path to the heating circulation direction.

[0013] In some embodiments, regulating the first regulating valve and the first throttling component according to at least one of the subcooling and superheat of the heat pump system further includes: when the current refrigerant state is a third state, setting the three-way valve to a first conducting state and setting the opening of the first throttling component to zero, so that the first refrigerant flow path does not participate in the refrigeration cycle, wherein the third state is a state in which the amount of refrigerant participating in the refrigeration cycle is moderate, and the first conducting state is to connect the first end and the third end of the three-way valve.

[0014] In some embodiments, determining the current refrigerant state based on at least one of the subcooling and superheat of the heat pump system includes: determining the current refrigerant state as a first state when the superheat of the heat pump system is less than a first superheat threshold; determining the current refrigerant state as a second state when the superheat of the heat pump system is greater than a second superheat threshold and the exhaust temperature of the heat pump system is greater than an exhaust temperature threshold, wherein the second superheat threshold is greater than the first superheat threshold; and determining the current refrigerant state as a third state when the superheat of the heat pump system is greater than or equal to a third superheat threshold and less than or equal to a fourth superheat threshold, wherein the third superheat threshold is greater than the first superheat threshold and the fourth superheat threshold is less than the second superheat threshold.

[0015] In some embodiments, determining the current refrigerant state based on at least one of the subcooling and superheat of the heat pump system includes: determining the current refrigerant state as a first state when the subcooling of the heat pump system is greater than a first subcooling threshold; determining the current refrigerant state as a second state when the subcooling of the heat pump system is less than a second subcooling threshold and the exhaust temperature of the heat pump system is greater than an exhaust temperature threshold, wherein the second subcooling threshold is less than the first subcooling threshold; and determining the current refrigerant state as a third state when the subcooling of the heat pump system is greater than or equal to a third subcooling threshold and less than or equal to a fourth subcooling threshold, wherein the third subcooling threshold is greater than the second subcooling threshold and the fourth subcooling threshold is less than the first subcooling threshold.

[0016] In some embodiments, determining at least one of the subcooling and superheat of the heat pump system includes: acquiring a pressure measurement value at the compressor suction port and a temperature measurement value at the compressor suction port; determining a saturated evaporation temperature based on the pressure measurement value at the compressor suction port; and determining the superheat based on the temperature measurement value at the compressor suction port and the saturated evaporation temperature.

[0017] In some embodiments, determining at least one of the subcooling and superheat of the heat pump system includes: acquiring a pressure measurement value at the outlet of the indoor heat exchanger and a temperature measurement value at the outlet of the indoor heat exchanger; determining a saturated condensing temperature based on the pressure measurement value at the outlet of the indoor heat exchanger; and determining the subcooling based on the temperature measurement value at the outlet of the indoor heat exchanger and the saturated condensing temperature.

[0018] In some embodiments, the heat collection component is a photovoltaic thermal component, and the heat pump system is a photovoltaic thermal heat pump system.

[0019] According to a second aspect of this disclosure, a controller is provided, comprising: a module for performing a control method for a heat pump system as described above.

[0020] According to a third aspect of this disclosure, a controller is provided, comprising: a memory; and a processor coupled to the memory, the processor being configured to execute the control method of the heat pump system as described above based on instructions stored in the memory.

[0021] According to a fourth aspect of this disclosure, a heat pump system is provided, comprising: a main refrigerant circulation path, including a compressor, an outdoor heat exchanger, an indoor heat exchanger, and a gas-liquid separator connected in series; a first refrigerant circulation path, connected in parallel with the pipeline section of the main refrigerant circulation path where the outdoor heat exchanger is located, including a heat collection component and a first throttling component; a first regulating valve, respectively connected to the main refrigerant circulation path and the first refrigerant circulation path, and connected to the gas-liquid separator through a second refrigerant circulation path; and a controller, configured to determine at least one of subcooling and superheating of the heat pump system in a cooling mode; and to regulate the first regulating valve and the first throttling component according to at least one of subcooling and superheating of the heat pump system to regulate the amount of refrigerant participating in the cooling cycle in the heat pump system.

[0022] In some embodiments, the first regulating valve is a three-way valve, with the first end of the three-way valve connected to the main refrigerant circulation path, the second end of the three-way valve connected to the second refrigerant path, and the third end of the three-way valve connected to the first refrigerant path.

[0023] In some embodiments, the controller regulates the first regulating valve and the first throttling component according to the superheat and exhaust temperature of the heat pump system. The heat pump system further includes: a first temperature sensor for acquiring the temperature measurement value of the compressor suction port; a first pressure sensor for acquiring the pressure measurement value of the compressor suction port, wherein the temperature measurement value and the pressure measurement value of the compressor suction port are used to determine the superheat; and a second temperature sensor for acquiring the exhaust temperature.

[0024] In some embodiments, the controller regulates the first regulating valve and the first throttling component based on the subcooling and exhaust temperature of the heat pump system. The heat pump system further includes: a third temperature sensor for acquiring a temperature measurement value at the outlet of the indoor heat exchanger; a second pressure sensor for acquiring a pressure measurement value at the outlet of the indoor heat exchanger, wherein the temperature measurement value and the pressure measurement value at the outlet of the indoor heat exchanger are used to determine the subcooling; and a second temperature sensor for acquiring the exhaust temperature.

[0025] According to a fifth aspect of this disclosure, a computer-readable storage medium is provided that stores computer program instructions thereon, which, when executed by a processor, implement the control method of the heat pump system as described above.

[0026] According to a sixth aspect of this disclosure, a computer program product is provided having computer program instructions stored thereon, which, when executed by a processor, implement the control method of the heat pump system as described above.

[0027] Other features and advantages of this disclosure will become clear from the following detailed description of exemplary embodiments with reference to the accompanying drawings. Attached Figure Description

[0028] The accompanying drawings, which form part of this specification, illustrate embodiments of this disclosure and, together with the specification, serve to explain the principles of this disclosure.

[0029] Figure 1 This is a schematic diagram of the piping structure of a heat pump system according to some embodiments of the present disclosure.

[0030] Figure 2 This is a schematic diagram of refrigerant flow under heating mode according to some embodiments of the present disclosure.

[0031] Figure 3 This is a schematic diagram of refrigerant flow under some embodiments of the present disclosure in a cooling mode.

[0032] Figure 4 This is a schematic flowchart of a control method for a heat pump system according to some embodiments of the present disclosure.

[0033] Figure 5 This is a schematic flowchart of a control method for a heat pump system according to other embodiments of the present disclosure.

[0034] Figure 6 This is a schematic diagram of the piping structure of a heat pump system according to other embodiments of this disclosure.

[0035] Figure 7 This is a schematic flowchart of a control method for a heat pump system according to some embodiments of the present disclosure.

[0036] Figure 8 This is a block diagram of the structural composition of a controller according to some embodiments of the present disclosure.

[0037] Figure 9 This is a block diagram of the structural composition of a controller according to other embodiments of the present disclosure.

[0038] Figure 10 This is a structural block diagram of a heat pump system according to some embodiments of the present disclosure.

[0039] This disclosure can be more clearly understood with reference to the accompanying drawings and the following detailed description. Detailed Implementation

[0040] Various exemplary embodiments of the present disclosure will now be described in detail with reference to the accompanying drawings. It should be noted that, unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of the present disclosure.

[0041] At the same time, it should be understood that, for ease of description, the dimensions of the various parts shown in the accompanying drawings are not drawn according to actual scale.

[0042] The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit this disclosure or its application or use.

[0043] Techniques, methods, and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and equipment should be considered part of the specification.

[0044] In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values.

[0045] It should be noted that similar labels and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be discussed further in subsequent figures.

[0046] To make the objectives, technical solutions, and advantages of this disclosure clearer, the following detailed description is provided in conjunction with specific embodiments and accompanying drawings. To address at least one of the problems existing in related heat pump control schemes, such as the potential refrigerant imbalance after switching from heating mode to cooling mode, this disclosure provides a control method, apparatus, and heat pump system for a heat pump system.

[0047] Figure 1 This is a schematic diagram of the piping structure of a heat pump system according to some embodiments of this disclosure. In the embodiments of this disclosure, the refrigerant charge in the heat pump system is determined according to the operating requirements of the system in heating mode. For example, the refrigerant charge is consistent with the refrigerant requirement corresponding to the optimal energy efficiency ratio in the system's heating mode. Figure 1 As shown, the heat pump system includes a main refrigerant circulation path 10, a first refrigerant circulation path 20, a second refrigerant circulation path 30, and a first regulating valve 40.

[0048] The main refrigerant circulation path 10 includes a compressor 11, an outdoor heat exchanger 12, an indoor heat exchanger 13, and a gas-liquid separator 14 connected in series. In some examples, the main refrigerant circulation path 10 also includes a second regulating valve 16 and a second throttling assembly 15. The second regulating valve 16 is used to switch the refrigerant flow direction in the main refrigerant circulation path 10. For example, the second regulating valve 16 is a four-way valve. The second throttling assembly 15 is located on the pipe section of the main refrigerant circulation path 10 where the outdoor heat exchanger is located, and is used for throttling.

[0049] The first refrigerant flow path 20 is connected in parallel with the pipe section where the outdoor heat exchanger 12 is located in the main refrigerant circulation flow path 10. The first refrigerant flow path 20 includes a heat collection assembly 21 and a first throttling assembly 22.

[0050] In some examples, the heat collector 21 can be a photovoltaic (PV) thermal module or a solar thermal module. When the heat collector is a PV thermal module, the heat pump system is specifically a PV thermal heat pump system. By making the heat collector 21 a PV thermal module, both power generation and heat storage functions can be achieved, which helps improve the energy-saving performance of the heat pump system. The first throttling component 22 can be an electronic expansion valve, a thermal expansion valve, or other components that can perform throttling. The first regulating valve 40 is connected to the main refrigerant circulation path 10 and the first refrigerant path 20, respectively, and is connected to the gas-liquid separator 14 through the second refrigerant path 30.

[0051] In some examples, the first regulating valve 40 can be a three-way valve. In these examples, the first end of the three-way valve can be connected to the main refrigerant circulation path 10, the second end of the three-way valve can be connected to the second refrigerant circulation path 30, and the third end of the three-way valve can be connected to the first refrigerant circulation path 20. Furthermore, in specific implementations, the first regulating valve 40 can also be other valves capable of switching on and off. By making the first regulating valve a three-way valve, bidirectional on / off control can be achieved with a relatively simple valve structure, saving on the cost of modifying the heat pump system piping.

[0052] The first regulating valve 40 and the first throttling assembly 22 can be configured to regulate the amount of refrigerant participating in the refrigeration cycle in the heat pump system under the control of the controller.

[0053] In some examples, in cooling mode, when there is too much refrigerant participating in the refrigeration cycle in the heat pump system, some refrigerant can be stored in the first refrigerant flow path by adjusting components such as the first regulating valve 40 and the first throttling component 22. In cooling mode, when there is too little refrigerant participating in the refrigeration cycle in the heat pump system, some refrigerant can be re-entering the main refrigerant circulation flow path 10 from the first refrigerant flow path 20 by adjusting components such as the first regulating valve 40 and the first throttling component 22.

[0054] In this embodiment, by introducing a first regulating valve and a second refrigerant flow path between the first regulating valve and the gas-liquid separator into the heat pump system, it is convenient to subsequently adjust the amount of refrigerant participating in the refrigeration cycle based on this pipeline structure. This solves the problems in related technologies that may occur after switching from heating mode to cooling mode, such as refrigerant imbalance, increased condensing pressure, increased compressor power consumption, and decreased energy efficiency caused by refrigerant imbalance. Moreover, due to the use of a controller-controllable first throttling component and a first regulating valve, the control reliability of the heat pump system is improved compared to manually operated shut-off valves.

[0055] The following combination Figure 2 and Figure 3 right Figure 1 The refrigerant flow direction of the heat pump system under different operating modes is illustrated by example.

[0056] In heating mode, the refrigerant circulates in the main refrigerant circulation path 10 and the first refrigerant circulation path 20. For example... Figure 2 As shown, Figure 1 The refrigerant flow in the heat pump system shown in heating mode is as follows: After being compressed by compressor 11, the refrigerant becomes a high-temperature, high-pressure gaseous refrigerant, which then enters the piping section where the indoor heat exchanger is located via the second regulating valve 16. The second regulating valve 16 can be a four-way valve, with its second and fourth ends connected. The high-temperature, high-pressure gaseous refrigerant, after passing through the indoor heat exchanger 13, forms a high-pressure, low-temperature liquid refrigerant, which is then divided into two paths after entering the branch pipe 17: one path enters the piping section where the outdoor heat exchanger 12 is located, and after passing through the second throttling assembly 15, it forms a low-temperature, low-pressure liquid refrigerant. The gas-liquid two-phase refrigerant then passes through the outdoor heat exchanger 12 to form a medium-temperature, low-pressure gas-liquid two-phase refrigerant; another refrigerant enters the first refrigerant flow path where the heat collector assembly 21 is located, and after passing through the first throttling assembly 22, it forms a low-temperature, low-pressure gas-liquid two-phase refrigerant, and then after passing through the heat collector assembly 21, it forms a medium-temperature, low-pressure gas-liquid two-phase refrigerant; next, these two medium-temperature, low-pressure gas-liquid two-phase refrigerants enter the pipeline section where the gas-liquid separator 14 is located through the second regulating valve 16, and then return to the compressor 11 after the liquid refrigerant in the gas-liquid two-phase refrigerant is filtered out by the gas-liquid separator 14.

[0057] In cooling mode, the refrigerant circulates within the main refrigerant circulation path. For example... Figure 3 As shown, Figure 1The refrigerant flow in the heat pump system shown in cooling mode is as follows: After being compressed by the compressor 11, the refrigerant becomes a high-temperature, high-pressure gaseous refrigerant, and then enters the pipeline section where the outdoor heat exchanger 12 is located through the second regulating valve 16. The second regulating valve 16 can be a four-way valve, and the second and third ends of the four-way valve are open. After passing through the outdoor heat exchanger 12, the high-temperature, high-pressure gaseous refrigerant forms a high-pressure, low-temperature liquid refrigerant, and then forms a low-temperature, low-pressure gas-liquid two-phase refrigerant after passing through the second throttling component 15. The low-temperature, low-pressure gas-liquid two-phase refrigerant enters the pipeline section where the indoor heat exchanger 13 is located through the branch pipe 17, and forms a low-temperature, low-pressure gaseous refrigerant after passing through the indoor heat exchanger 13. Subsequently, the low-temperature, low-pressure gaseous refrigerant enters the pipeline section where the gas-liquid separator 14 is located, and returns to the compressor 11 after being further filtered by the gas-liquid separator 14.

[0058] exist Figure 1 Based on the pipeline structure shown, this disclosure provides a control method for a heat pump system. For example... Figure 4 As shown, the control method of the heat pump system includes steps S41 and S42.

[0059] Step S41: In cooling mode, determine at least one of the subcooling and superheat of the heat pump system.

[0060] In practice, step S41 can be implemented in various ways. The following describes step S41 in detail with reference to three examples.

[0061] In the first example, in step S41, the subcooling of the heat pump system is determined. Subcooling is generally understood as the difference between the saturation temperature and the actual temperature of the liquid refrigerant. In this example, the subcooling of the heat pump system can be determined as follows: obtaining the pressure and temperature measurements at the outlet of the indoor heat exchanger; determining the saturated condensation temperature based on the pressure measurement at the outlet of the indoor heat exchanger; and determining the subcooling based on the temperature measurement at the outlet of the indoor heat exchanger and the saturated condensation temperature. By obtaining the pressure and temperature measurements at the outlet of the indoor heat exchanger and determining the subcooling accordingly, the accuracy of the calculated subcooling can be improved, which helps to more accurately assess the current refrigerant state and thus more accurately adjust the amount of refrigerant participating in the refrigeration cycle in the heat pump system.

[0062] In the second example, in step S41, the superheat of the heat pump system is determined. Superheat can be understood as the difference between the actual temperature and the saturation temperature of the gaseous refrigerant (or gaseous refrigerant). In this example, the superheat of the heat pump system can be determined as follows: obtain the pressure measurement value and temperature measurement value of the compressor suction port; determine the saturation evaporation temperature based on the pressure measurement value of the compressor suction port; and determine the superheat based on the temperature measurement value of the compressor suction port and the saturation evaporation temperature. By obtaining the pressure measurement value and temperature measurement value of the compressor suction port and determining the superheat accordingly, the accuracy of the calculated superheat can be improved, which helps to more accurately assess the current refrigerant state and thus more accurately adjust the amount of refrigerant participating in the refrigeration cycle in the heat pump system.

[0063] In the third example, in step S41, the subcooling and superheat of the heat pump system are determined.

[0064] Step S42: Adjust the first regulating valve and the first throttling component according to at least one of the subcooling and superheat of the heat pump system to adjust the amount of refrigerant participating in the refrigeration cycle in the heat pump system.

[0065] Step S42 can be implemented in various ways. The following describes step S42 in detail with reference to three examples.

[0066] In the first example, the first regulating valve and the first throttling component are adjusted according to the subcooling degree and the exhaust temperature of the heat pump system to regulate the amount of refrigerant participating in the refrigeration cycle in the heat pump system.

[0067] In the second example, the first regulating valve and the first throttling component are adjusted according to the superheat of the heat pump system and the exhaust temperature of the heat pump system to regulate the amount of refrigerant participating in the refrigeration cycle in the heat pump system.

[0068] In the third example, the first regulating valve and the first throttling component are adjusted based on the subcooling, superheat, and exhaust temperature of the heat pump system to regulate the amount of refrigerant participating in the refrigeration cycle. The subcooling, superheat, and exhaust temperature of the heat pump system can, to some extent, reflect whether the current amount of refrigerant participating in the refrigeration cycle is excessive, insufficient, or normal. Furthermore, in practical implementations, the first regulating valve and the first throttling component can be adjusted based solely on either the subcooling or the superheat to regulate the amount of refrigerant participating in the refrigeration cycle.

[0069] In this embodiment, by determining whether the amount of refrigerant participating in the refrigeration cycle is too much or too little based on at least one of the subcooling and superheating of the heat pump system, and accordingly regulating the first regulating valve and the first throttling component, it helps to automatically and reliably adjust the amount of refrigerant participating in the refrigeration cycle in the heat pump system, solving problems such as refrigerant imbalance existing in related technologies. This method is particularly suitable for energy-saving air conditioning fields such as photovoltaic thermal heat pump systems, and can further improve system energy efficiency and enhance the energy-saving effect of energy-saving air conditioning.

[0070] Figure 5 This is a schematic flowchart illustrating a control method for a heat pump system according to other embodiments of this disclosure. Figure 5 As shown, the control method of the heat pump system includes steps S51 to S55.

[0071] Step S51: In cooling mode, determine at least one of the subcooling and superheat of the heat pump system. For instructions on how to determine the subcooling and superheat of the heat pump system, please refer to the relevant descriptions in the foregoing embodiments.

[0072] Step S52: Determine the current refrigerant state based on at least one of the subcooling and superheat of the heat pump system.

[0073] The refrigerant state includes three states: state one, state two, and state three. State one represents an excess of refrigerant participating in the refrigeration cycle. State two represents an insufficient amount of refrigerant participating in the refrigeration cycle. State three represents a moderate amount of refrigerant participating in the refrigeration cycle.

[0074] In practice, step S52 can be implemented in various ways. The following describes step S52 in detail with two examples.

[0075] In the first example, step S52 includes: determining the current refrigerant state as a first state when the superheat of the heat pump system is less than a first superheat threshold; determining the current refrigerant state as a second state when the superheat of the heat pump system is greater than a second superheat threshold and the exhaust temperature of the heat pump system is greater than an exhaust temperature threshold, wherein the second superheat threshold is greater than the first superheat threshold; and determining the current refrigerant state as a third state when the superheat of the heat pump system is greater than or equal to a third superheat threshold and less than or equal to a fourth superheat threshold. The third superheat threshold is greater than the first superheat threshold, and the fourth superheat threshold is less than the second superheat threshold. In specific implementations, the first to fourth superheat thresholds and the exhaust temperature threshold can be flexibly set. For example, the first superheat threshold can be set to 3°C, the second superheat threshold to 12°C, the third superheat threshold to 5°C, the fourth superheat threshold to 8°C, and the exhaust temperature threshold to 95°C.

[0076] In this embodiment, by combining the superheat and exhaust temperature of the heat pump system, the current refrigerant state can be determined more accurately, which helps to accurately control the amount of refrigerant participating in the refrigeration cycle based on the refrigerant state. Furthermore, by setting first to fourth superheat thresholds and comparing the superheat with these thresholds, and combining the comparison results of exhaust temperature with the exhaust temperature threshold, the three refrigerant states—excessive refrigerant, insufficient refrigerant, and moderate refrigerant—can be identified more accurately and conveniently. This facilitates flexible adjustment of components in the heat pump system for different refrigerant states, thereby improving the control accuracy and flexibility of the heat pump system.

[0077] In the second example, step S52 includes: determining the current refrigerant state as a first state when the subcooling of the heat pump system is greater than a first subcooling threshold; determining the current refrigerant state as a second state when the subcooling of the heat pump system is less than a second subcooling threshold and the exhaust temperature of the heat pump system is greater than an exhaust temperature threshold, wherein the second subcooling threshold is less than the first subcooling threshold; and determining the current refrigerant state as a third state when the subcooling of the heat pump system is greater than or equal to a third subcooling threshold and less than or equal to a fourth subcooling threshold. The third subcooling threshold is greater than the second subcooling threshold, and the fourth subcooling threshold is less than the first subcooling threshold. In specific implementations, the first to fourth subcooling thresholds and the exhaust temperature threshold can be flexibly set.

[0078] In this embodiment, by combining the subcooling degree and exhaust temperature of the heat pump system, the current refrigerant state can be determined more accurately, which helps to accurately control the amount of refrigerant participating in the refrigeration cycle based on the refrigerant state. Furthermore, by setting first to fourth subcooling degree thresholds and comparing the subcooling degree with these thresholds, and combining the comparison results of exhaust temperature with the exhaust temperature threshold, the three refrigerant states—excessive refrigerant, insufficient refrigerant, and moderate refrigerant—can be identified more accurately and conveniently. This facilitates flexible adjustment of components in the heat pump system for different refrigerant states, thereby improving the control accuracy and flexibility of the heat pump system.

[0079] In addition to the two examples mentioned above, other methods can be used to determine the refrigerant status in practice. For example, the refrigerant status can be determined based solely on subcooling, or solely on superheat, or based on both subcooling and superheat, etc.

[0080] If the current refrigerant state is in the first state, proceed to step S53; if the current refrigerant state is in the second state, proceed to step S54; if the current refrigerant state is in the third state, proceed to step S55.

[0081] Step S53: Perform the first sub-control on the first regulating valve and the first throttling assembly.

[0082] In some examples, the first regulating valve is a three-way valve. The first end of the three-way valve is connected to the main refrigerant circulation path, the second end is connected to the second refrigerant circulation path, and the third end is connected to the first refrigerant circulation path. In these examples, in step S53, the first regulating valve and the first throttling assembly can be first sub-regulated as follows: according to a set switching cycle, the three-way valve is switched between a first conducting state and a second conducting state, wherein the first conducting state connects the first and third ends of the three-way valve, and the second conducting state connects the second and third ends of the three-way valve; the first throttling assembly is set to a first opening degree to connect the first refrigerant circulation path with the pipe section in the main refrigerant circulation path where the indoor heat exchanger is located. The first opening degree is greater than 0 and less than or equal to a first opening degree threshold. In specific implementations, the first opening degree threshold can be flexibly set. For example, the first opening degree threshold can be set to 50 steps.

[0083] It should be noted that switching the three-way valve between the first and second conducting states means that for a portion of a switching cycle, the three-way valve is maintained in the second conducting state, and for the remaining portion of the cycle, it is maintained in the first conducting state. In practice, the specific value of the switching cycle can be flexibly set. For example, the switching cycle can be 30 seconds, with the three-way valve maintained in the second conducting state for 0-15 seconds and in the first conducting state for 15-30 seconds.

[0084] Furthermore, in the above example, when the current refrigerant state is the first state, in addition to the first sub-control of the first regulating valve and the first throttling component, the second throttling component 15 on the pipeline section where the outdoor heat exchanger is located can also be adjusted as follows: reduce the opening degree of the second throttling component 15, and make the reduced opening degree of the second throttling component greater than or equal to the second opening degree threshold. Wherein, the second opening degree threshold is greater than or equal to the first opening degree threshold. For example, both the first and second opening degree thresholds are set to 50 steps. Alternatively, the first opening degree threshold is set to 40 steps, and the second opening degree threshold is set to 60 steps. In specific implementation, the opening degree of the second throttling component can be reduced by a fixed step size, or by a variable step size. For example, the opening degree of the second throttling component is reduced by 10 steps each time, and the reduced opening degree of the second throttling component is not less than 50 steps.

[0085] It should be noted that during step S53, the refrigerant flow direction in the main refrigerant circulation path is the same as the refrigeration circulation direction. In practice, if the current refrigerant flow direction in the main refrigerant circulation path is the refrigeration circulation direction, then the refrigeration circulation direction remains unchanged. If the current refrigerant flow direction in the main refrigerant circulation path is not the refrigeration circulation direction, then the refrigerant flow direction in the main refrigerant circulation path is switched to the refrigeration circulation direction.

[0086] In this embodiment of the disclosure, by performing a first sub-control on the first regulating valve and the first throttling component when there is too much refrigerant, a portion of the refrigerant in the main refrigerant circulation path is driven to be stored in the first refrigerant circulation path. This can effectively solve the problems of excessive refrigerant in the system due to the reduction in the volume of the refrigerant circulation loop after switching from heating mode to cooling mode, as well as the resulting increase in condensing pressure, increase in compressor power consumption, and decrease in energy efficiency.

[0087] Furthermore, by periodically switching the on / off state of the three-way valve and setting the first throttling component to a smaller opening when there is excessive refrigerant, excess liquid refrigerant in the main refrigerant circulation path can be gradually "squeezed" into the first refrigerant circulation path 20 where the heat collector is located. This allows excess refrigerant in the main refrigerant circulation path to be stored in the first refrigerant circulation path 20. It also allows time for the refrigerant that might enter the main refrigerant circulation path through the second refrigerant circulation path 30 to vaporize, ensuring that the compressor draws in compressible gaseous refrigerant and preventing liquid slugging damage to the compressor. At the same time, by setting the first throttling component to a smaller opening and reducing the opening of the second throttling component, the pressure in the pipe section where the outdoor heat exchanger is located can be increased, creating a pressure difference between this pipe section and the first refrigerant circulation path where the heat collector is located. This allows more excess refrigerant flowing from the pipe section where the indoor heat exchanger 13 is located to flow into the first refrigerant circulation path. Furthermore, after passing through the throttling effect of the first throttling component, the refrigerant flowing into the first refrigerant flow path experiences a pressure and temperature reduction, resulting in partial liquefaction. This portion of the refrigerant can then be "temporarily stored" using the internal volume of the first refrigerant flow path. This further improves the refrigerant quantity regulation effect.

[0088] Step S54: Perform a second sub-control on the first regulating valve and the first throttling assembly.

[0089] In some examples, the first regulating valve is a three-way valve. The first end of the three-way valve is connected to the main refrigerant circulation path, the second end is connected to the second refrigerant circulation path, and the third end is connected to the first refrigerant circulation path. In these examples, the first regulating valve and the first throttling component can be subjected to a second sub-control according to the following exemplary method: setting the three-way valve to a first conducting state, wherein the first conducting state is to connect the first and third ends of the three-way valve; increasing the opening degree of the first throttling component, and making the increased opening degree of the first throttling component less than or equal to a first opening degree threshold; and switching the refrigerant flow direction in the main refrigerant circulation path to the heating circulation direction, and making the refrigerant circulate according to the heating circulation direction for a set duration. The value of the first opening degree threshold can be flexibly set. For example, the first opening degree threshold can be set to 50 steps or 40 steps, etc. In specific implementation, the opening degree of the first throttling component can be increased in fixed steps or in variable steps. For example, each time the opening of the first throttling component is increased by 10 steps, and the increased opening of the first throttling component is not greater than 50 steps.

[0090] In some examples, the main refrigerant circulation path 10 includes a second regulating valve 16. In these examples, the refrigerant flow direction in the main refrigerant circulation path can be switched to the heating circulation direction by regulating the second regulating valve, and the refrigerant can circulate in the heating circulation direction for a set duration. The set duration can be flexibly set. For example, the set duration can be 90 seconds or 80 seconds.

[0091] In this embodiment of the disclosure, by performing a second sub-control on the first regulating valve and the first throttling component when the refrigerant quantity is too low, and changing the refrigerant circulation direction, a portion of the refrigerant stored in the first refrigerant flow path is driven into the main refrigerant circulation flow path. This can effectively solve the problems of insufficient effective circulating refrigerant quantity in the system, as well as the resulting insufficient condensing pressure and poor cooling effect.

[0092] Furthermore, by increasing the opening of the first throttling component when the refrigerant quantity is too low, and ensuring that the increased opening of the first throttling component is less than or equal to the first opening threshold, not only can the refrigerant in the first refrigerant flow path where the heat collector is located better participate in the refrigerant circulation of the system, alleviating the problem of insufficient refrigerant quantity circulating in the system, but it can also ensure that the first throttling component always maintains a certain throttling pressure difference, allowing the liquid refrigerant entering the first refrigerant flow path to fully depressurize and cool down, and vaporize smoothly. This prevents the liquid refrigerant entering the first refrigerant flow path from directly "rushing" through the heat collector and flowing into the return gas pipe, which would otherwise cause compressor liquid slugging risk. Meanwhile, in this embodiment, in addition to increasing the opening of the first throttling component when the refrigerant quantity is too low, the refrigerant circulation direction is adjusted to the heating circulation direction, and the three-way valve is set to the first conducting state. Because the heating circulation path from the compressor to the indoor heat exchanger is on the high-pressure side, the refrigerant stored in the first refrigerant path, after absorbing heat and vaporizing, merges with the refrigerant in the outdoor heat exchanger path and enters the gas-liquid separator path via the second regulating valve, returning to the compressor. Due to the large refrigerant heat exchange area of ​​the heat collection component and the high outdoor ambient temperature, adjusting the refrigerant circulation direction to the heating circulation direction allows the refrigerant stored in the first refrigerant path to be fully vaporized by the heat collection component before returning to the main refrigerant circulation path. Compared to simply increasing the opening of the first throttling component when the refrigerant quantity is too low, allowing the liquid refrigerant in the first refrigerant path to return to the compressor via the indoor heat exchanger, this further reduces the risk of compressor liquid slugging and mitigates the potential compressor damage caused by the small heat exchange area of ​​the indoor heat exchanger failing to completely vaporize the surge in liquid refrigerant.

[0093] Step S55: Perform third sub-control on the first regulating valve and the first throttling assembly.

[0094] In some examples, the first regulating valve is a three-way valve. The first end of the three-way valve is connected to the main refrigerant circulation path, the second end is connected to the second refrigerant circulation path, and the third end is connected to the first refrigerant circulation path. In these examples, the first regulating valve and the first throttling assembly can be third-sub-regulated in the following exemplary manner: the three-way valve is set to a first conducting state, and the opening of the first throttling assembly is set to zero, so that the first refrigerant circulation path does not participate in the refrigeration cycle. The first conducting state means connecting both the first and third ends of the three-way valve.

[0095] In this embodiment of the disclosure, by setting the three-way valve to the first conducting state and setting the opening degree of the first throttling component to zero when the current refrigerant quantity is appropriate, the first refrigerant flow path where the heat collection component is located can be prevented from participating in the refrigeration cycle, thus avoiding the refrigerant from ineffectively absorbing heat and affecting the refrigeration effect, while also not affecting the normal refrigeration of the system.

[0096] In this embodiment, the above process enables bidirectional adaptive adjustment of the refrigerant quantity participating in the refrigeration cycle. When there is too much refrigerant participating in the refrigeration cycle, the excess refrigerant is absorbed by the liquid storage in the first refrigerant flow path; when there is too little refrigerant participating in the refrigeration cycle, the liquid storage in the first refrigerant flow path is released through a brief heating mode. This achieves bidirectional adaptive adjustment of the refrigerant quantity, which helps alleviate problems caused by refrigerant imbalance and improves the operating efficiency and reliability of the heat pump system. Moreover, the above method is compatible with the existing piping structure of heat pump systems, requiring no changes to the main pipeline layout. It is suitable for retrofitting existing systems, has a low implementation threshold, and saves costs.

[0097] Figure 6 This is a schematic diagram of the piping structure of a heat pump system according to other embodiments of this disclosure. For example... Figure 6 As shown, the heat pump system in this embodiment of the present disclosure is... Figure 1 Based on the pipeline structure shown, a first temperature sensor 51, a first pressure sensor 52, and a second temperature sensor 53 are further introduced.

[0098] The first temperature sensor 51 is used to collect the temperature measurement value of the compressor intake port.

[0099] The first pressure sensor 52 is used to collect the pressure measurement value of the compressor suction port.

[0100] The second temperature sensor 53 is used to collect the exhaust temperature.

[0101] Furthermore, the heat pump system also includes a controller. The controller is used to determine the superheat based on the measured temperature and pressure at the compressor suction port; and to regulate the first regulating valve and the first throttling assembly based on the superheat and the exhaust temperature to adjust the amount of refrigerant participating in the refrigeration cycle in the heat pump system.

[0102] exist Figure 6 In the heat pump system shown, the first regulating valve is specifically a three-way valve, the first throttling component is specifically a first electronic expansion valve, the second throttling component is specifically a second electronic expansion valve, and the second regulating valve is specifically a four-way valve. Based on this heat pump system, this disclosure further provides a control method for the heat pump system in some embodiments. The following, in conjunction with… Figure 7 The control method of a heat pump system according to some embodiments of this disclosure will be described. For example... Figure 7 As shown, the control method of the heat pump system includes steps S71 to S78.

[0103] Step S71: Parameter settings.

[0104] In some embodiments, parameter settings include setting first to fourth superheat thresholds, a first exhaust temperature threshold (i.e., the aforementioned "exhaust temperature threshold"), and a second exhaust temperature threshold. For example, the first superheat threshold SHmin is set to 3°C, the second superheat threshold SHmax is set to 12°C, the third superheat threshold SH1 is set to 5°C, the fourth superheat threshold SH2 is set to 8°C, the first exhaust temperature threshold is set to 95°C, and the second exhaust temperature threshold is set to 105°C.

[0105] Step S72: Determine whether the operating mode is cooling mode or heating mode.

[0106] If the heat pump system is determined to be operating in heating mode, proceed to step S73. If the heat pump system is determined to be operating in cooling mode, proceed to step S74.

[0107] Step S73: Switch the four-way valve to the heating position and set the three-way valve to the first conducting state.

[0108] In some examples, switching the four-way valve to the heating position specifically involves opening the second and fourth terminals, and the first and third terminals. Setting the three-way valve to the first conducting state involves opening the first and third terminals. Furthermore, in heating mode, the first electronic expansion valve is kept at a certain opening degree. Through step S73, in heating mode, the first refrigerant flow path where the heat collection assembly is located is connected in parallel with the pipeline section where the outdoor heat exchanger is located, enabling the system to operate efficiently in heating mode.

[0109] In some embodiments, in heating mode, in addition to performing step S73, the second electronic expansion valve can also be controlled. For example, if the compressor's suction superheat is too high, the opening of the second electronic expansion valve is reduced; if the compressor's suction superheat is too low, the opening of the second electronic expansion valve is increased.

[0110] Step S74: Switch the four-way valve to the cooling position, set the three-way valve to the second conducting state, and close the first electronic expansion valve.

[0111] Step S74 is the default refrigeration control logic. In some examples, switching the four-way valve to the refrigeration position specifically involves: opening the second and third terminals of the four-way valve, and opening the first and fourth terminals. Setting the three-way valve to the second energized state involves: opening the second and third terminals of the three-way valve.

[0112] With the operating mode determined to be cooling mode, the system operates for a period of time according to the default cooling control logic shown in step S74. Subsequently, the measured values ​​of the first pressure sensor, the first temperature sensor, and the second temperature sensor are periodically monitored.

[0113] Step S75: Obtain the pressure measurement value P1 and temperature measurement value T1 of the compressor suction port, and the exhaust temperature T2. In step S75, the pressure measurement value of the compressor suction port is obtained from the first pressure sensor, the temperature measurement value of the compressor suction port is obtained from the first temperature sensor, and the exhaust temperature is obtained from the second temperature sensor.

[0114] Step S76: Calculate the superheat SH.

[0115] In some examples, the superheat SH is calculated as follows: the saturation temperature T1' corresponding to the compressor suction port pressure measurement P1 is calculated using the Antoine equation; the superheat is then calculated using the formula SH = T1 - T1'. The Antoine equation is: Where A, B, and C are constants, P is pressure, and T is saturation temperature. When the refrigerant is R32, A = 14.5178, B = 1924.06, and C = -27.13.

[0116] If the superheat SH is less than the first superheat threshold SHmin, proceed to step S77. If the superheat SH is greater than the second superheat threshold SHmax and the exhaust temperature T2 is greater than the first exhaust temperature threshold Tmax, proceed to step S78. If the superheat SH is greater than or equal to the third superheat threshold SH1 and less than or equal to the fourth superheat threshold SH2, proceed to step S79.

[0117] Step S77: Switch the three-way valve between the first and second conducting states, set the first electronic expansion valve to the first opening degree, and reduce the opening degree of the second electronic expansion valve.

[0118] For example, the three-way valve is switched on and off every 30 seconds, intermittently connecting the first refrigerant flow path containing the heat collector assembly to the gas-liquid separator; the opening of the second electronic expansion valve is reduced in fixed steps, such as 10 steps each time, with a minimum of 50 steps. Simultaneously, the first electronic expansion valve is kept at a small opening. For example, the opening range of the first electronic expansion valve is 10-50 steps. Next, the superheat SH is continuously monitored. If the superheat is within the range of (SH1, SH2), the periodic storage of refrigerant is stopped, the three-way valve is restored to its second on state, and the heat pump system resumes normal cooling. If the superheat SH is still less than SHmin, step S77 is repeated. After several monitoring cycles (e.g., four monitoring cycles), if the superheat SH is still less than SHmin, an abnormal refrigerant overload is determined, and an alarm message is output.

[0119] Step S78: Switch the four-way valve to the heating position, set the three-way valve to the first conducting state, and increase the opening of the first electronic expansion valve.

[0120] For example, the four-way valve is switched to the heating position and maintained for a certain time t (e.g., 90 seconds), and the three-way valve is set to the first conducting state; the opening of the first electronic expansion valve is increased in fixed steps (e.g., 10 steps), and the maximum cannot exceed 50% of the maximum opening of the electronic expansion valve. After time t ends, the four-way valve is switched to the cooling position. Next, the superheat SH is continuously monitored. If the superheat is within the range of (SH1, SH2), the periodic release of refrigerant is stopped, and the heat pump system is allowed to cool normally. If the superheat SH is still greater than SHmax, step S78 is repeated. After multiple monitoring cycles (e.g., three monitoring cycles), if the superheat SH is still greater than SHmax, a refrigerant abnormality is determined, and an alarm message is output. In some embodiments, the control method of the heat pump system may further include: stopping the heat pump system and outputting a system abnormality prompt message when the exhaust temperature is greater than a second exhaust temperature threshold.

[0121] Step S79: The system is cooling normally.

[0122] For example, in step S79, the three-way valve can be set to the second conducting state (that is, the second and third ends of the three-way valve are connected), the opening degree of the first electronic expansion valve is set to 0, the first refrigerant branch where the heat collection component is located does not participate in the circulation, and the system performs normal cooling.

[0123] In this embodiment of the disclosure, the above process achieves a dynamic balance of the amount of refrigerant participating in the refrigeration cycle within the system. This can solve the problem of dynamic refrigerant imbalance caused by the sudden change in the volume of the circulation loop due to the isolation of the first refrigerant flow path after the heat pump system, especially the PVT heat pump system, switches from heating mode to cooling mode.

[0124] Based on the piping structure of the heat pump system in the foregoing embodiments, this disclosure also proposes a controller. Figure 8 This is a block diagram illustrating the structural composition of a controller according to some embodiments of this disclosure. For example... Figure 8 As shown, the controller 80 includes a determination module 81 and a control module 82.

[0125] The determination module 81 is used to determine at least one of the subcooling and superheat of the heat pump system in cooling mode.

[0126] The control module 82 is used to control the first regulating valve and the first throttling component according to at least one of the subcooling and superheat of the heat pump system, so as to adjust the amount of refrigerant participating in the refrigeration cycle in the heat pump system.

[0127] In some embodiments, the controller further includes modules for performing other steps in the control method for the heat pump system as described above.

[0128] In this embodiment, by introducing a first regulating valve and a second refrigerant flow path between the first regulating valve and the gas-liquid separator into the heat pump system, it is convenient to subsequently adjust the amount of refrigerant participating in the refrigeration cycle based on this pipeline structure. This solves the refrigerant imbalance that may occur after switching from heating mode to cooling mode in related technologies, as well as other problems caused by the refrigerant imbalance. Moreover, due to the use of a controller-controllable first throttling component and a first regulating valve, the control reliability of the heat pump system is improved compared to manually operated shut-off valves.

[0129] Figure 9 This is a structural block diagram of a controller according to other embodiments of this disclosure. For example... Figure 9 As shown, the controller includes a memory 91 and a processor 92 coupled to the memory 91. The memory 91 is used to store instructions corresponding to embodiments of the control method for the heat pump system. The processor 92 is configured to execute the control method for the heat pump system in any of the embodiments of this disclosure based on the instructions stored in the memory 91.

[0130] Figure 10 This is a structural block diagram of a heat pump system according to some embodiments of the present disclosure. Figure 10 As shown, the heat pump system includes a main refrigerant circulation path 10, a first refrigerant circulation path 20, a first regulating valve 40, and a controller 80.

[0131] The main refrigerant circulation path 10 includes a compressor, an outdoor heat exchanger, an indoor heat exchanger, and a gas-liquid separator connected in series.

[0132] The first refrigerant circulation path 20 is connected in parallel with the pipe section containing the outdoor heat exchanger in the main refrigerant circulation path 10. The first refrigerant circulation path includes a heat collection component and a first throttling component. In some examples, the heat collection component is a photovoltaic thermal component, and the heat pump system is a photovoltaic thermal heat pump system.

[0133] The first regulating valve 40 is connected to the main refrigerant circulation path 10 and the first refrigerant path 20 respectively, and is connected to the gas-liquid separator through the second refrigerant path.

[0134] In some examples, the first regulating valve is a three-way valve. In these examples, the first end of the three-way valve can be connected to the main refrigerant circulation path 10, the second end of the three-way valve can be connected to the second refrigerant circulation path, and the third end of the three-way valve can be connected to the first refrigerant circulation path 20.

[0135] The controller 80 is configured to determine at least one of the subcooling and superheat of the heat pump system in cooling mode. The controller 80 is also configured to regulate the first regulating valve and the first throttling assembly based on at least one of the subcooling and superheat of the heat pump system to adjust the amount of refrigerant participating in the refrigeration cycle in the heat pump system.

[0136] In some examples, controller 80 regulates the first regulating valve and the first throttling assembly based on the superheat and exhaust temperature of the heat pump system. In these examples, the heat pump system includes, in addition to... Figure 10 In addition to the components shown, the system also includes a first temperature sensor, a first pressure sensor, and a second temperature sensor. The first temperature sensor can be installed on the pipeline section between the compressor suction port and the gas-liquid separator to collect the temperature measurement value of the compressor suction port. The first pressure sensor can be installed on the pipeline section between the compressor suction port and the gas-liquid separator to collect the pressure measurement value of the compressor suction port. The temperature and pressure measurements at the compressor suction port are used to determine the superheat. The second temperature sensor can be installed in the pipeline section near the compressor discharge port to collect the discharge temperature. In this embodiment, by setting the first temperature sensor and the first pressure sensor, it is convenient to accurately determine the superheat of the heat pump system and, based on this, determine the current refrigerant quantity status of the heat pump system. This helps to more efficiently adjust the amount of refrigerant participating in the refrigeration cycle in the heat pump system, improving the safety and reliability of the heat pump system operation.

[0137] In other examples, controller 80 regulates the first regulating valve and the first throttling assembly based on the subcooling and exhaust temperature of the heat pump system. In these examples, the heat pump system includes, in addition to... Figure 10 In addition to the components shown, the system also includes a second temperature sensor, a third temperature sensor, and a second pressure sensor. The second temperature sensor is used to collect the exhaust temperature. The third temperature sensor is used to collect the temperature measurement value at the outlet of the indoor heat exchanger. The second pressure sensor is used to collect the pressure measurement value at the outlet of the indoor heat exchanger. The temperature and pressure measurements at the outlet of the indoor heat exchanger are used to determine the subcooling. In this embodiment, by providing the third temperature sensor and the second pressure sensor, it is easier to accurately determine the subcooling of the heat pump system and, based on this, determine the current refrigerant quantity status of the heat pump system. This helps to more efficiently adjust the amount of refrigerant participating in the refrigeration cycle in the heat pump system, improving the safety and reliability of the heat pump system operation.

[0138] In this embodiment of the disclosure, the above system can effectively solve problems such as refrigerant imbalance that exist in related technologies.

[0139] Various aspects of this disclosure are described herein with reference to flowchart illustrations and / or block diagrams of a control method, controller, heat pump system, storage medium, and computer program product according to embodiments of this disclosure. It should be understood that each block of the flowchart illustrations and / or block diagrams, and combinations thereof, can be implemented by computer-readable program instructions.

[0140] These computer-readable program instructions are provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable device to produce a machine, such that execution of the instructions by the processor produces means for implementing the functions specified in one or more boxes of the flowchart and / or block diagram.

[0141] These computer-readable program instructions may also be stored in a computer-readable storage medium. These instructions cause a computer to work in a particular manner to produce an article of manufacture, including instructions that implement the functions specified in one or more boxes in a flowchart and / or block diagram.

[0142] This disclosure may take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects.

[0143] The data processing method, apparatus, and building control system according to this disclosure have now been described in detail. To avoid obscuring the concept of this disclosure, some details known in the art have not been described. Those skilled in the art can fully understand how to implement the technical solutions disclosed herein based on the above description.

Claims

1. A control method for a heat pump system, wherein, The heat pump system includes: The main refrigerant circulation path includes a compressor, an outdoor heat exchanger, an indoor heat exchanger, and a gas-liquid separator connected in series. The first refrigerant flow path is connected in parallel with the pipeline section where the outdoor heat exchanger is located in the main refrigerant circulation flow path, and includes a heat collection component and a first throttling component; The first regulating valve is connected to the main refrigerant circulation path and the first refrigerant path respectively, and is connected to the gas-liquid separator through the second refrigerant path; The control method for the heat pump system includes: In cooling mode, determine at least one of the subcooling and superheat of the heat pump system; The first regulating valve and the first throttling component are adjusted according to at least one of the subcooling and superheat of the heat pump system to regulate the amount of refrigerant participating in the refrigeration cycle in the heat pump system.

2. The control method for a heat pump system according to claim 1, wherein, Regulating the first regulating valve and the first throttling assembly based on at least one of the subcooling and superheat of the heat pump system includes: The current refrigerant state is determined based on at least one of the subcooling and superheat of the heat pump system. When the current refrigerant state is the first state, the first regulating valve and the first throttling component are subjected to a first sub-regulation to drive a portion of the refrigerant in the main refrigerant circulation path to be stored in the first refrigerant circulation path, wherein the first state is a state in which the amount of refrigerant participating in the refrigeration cycle is excessive.

3. The control method for a heat pump system according to claim 2, wherein, The regulation of the first regulating valve and the first throttling component based on at least one of the subcooling and superheat of the heat pump system further includes: When the current refrigerant state is the second state, the first regulating valve and the first throttling component are subject to a second sub-regulation to drive a portion of the refrigerant stored in the first refrigerant flow path into the main refrigerant circulation flow path, wherein the second state is a state in which the amount of refrigerant participating in the refrigeration cycle is too small.

4. The control method for a heat pump system according to claim 3, wherein, The first regulating valve is a three-way valve. The first end of the three-way valve is connected to the main refrigerant circulation path, the second end of the three-way valve is connected to the second refrigerant path, and the third end of the three-way valve is connected to the first refrigerant path.

5. The control method for a heat pump system according to claim 4, wherein, The first sub-control of the first regulating valve and the first throttling assembly includes: According to a set switching cycle, the three-way valve switches between a first on state and a second on state, wherein the first on state connects the first and third terminals of the three-way valve, and the second on state connects the second and third terminals of the three-way valve; and, The first throttling component is set to a first opening degree so that the first refrigerant flow path is connected to the pipe section where the indoor heat exchanger is located in the main refrigerant circulation flow path, wherein the first opening degree is greater than 0 and less than or equal to a first opening degree threshold.

6. The control method for a heat pump system according to claim 5, wherein, The pipeline section where the outdoor heat exchanger is located also includes a second throttling component, and the method further includes: When the current refrigerant state is the first state, the opening degree of the second throttling component is reduced, and the reduced opening degree of the second throttling component is made greater than or equal to the second opening degree threshold, wherein the second opening degree threshold is greater than or equal to the first opening degree threshold.

7. The control method for a heat pump system according to claim 4, wherein, The second sub-control of the first regulating valve and the first throttling assembly includes: The three-way valve is set to a first conducting state, wherein the first conducting state is to connect the first and third ends of the three-way valve; Increase the opening degree of the first throttling component, and make the increased opening degree of the first throttling component less than or equal to the first opening degree threshold; and, Switch the refrigerant flow direction in the main refrigerant circulation path to the heating circulation direction, and set the refrigerant circulation time according to the heating circulation direction.

8. The control method for a heat pump system according to claim 7, wherein, The main refrigerant circulation path further includes a second regulating valve, which switches the refrigerant flow direction in the main refrigerant circulation path to the heating circulation direction, including: The second regulating valve is adjusted to switch the refrigerant flow direction in the main refrigerant circulation path to the heating circulation direction.

9. The control method for a heat pump system according to claim 4, wherein, The regulation of the first regulating valve and the first throttling component based on at least one of the subcooling and superheat of the heat pump system further includes: When the current refrigerant state is the third state, the three-way valve is set to the first conducting state and the opening degree of the first throttling component is set to zero so that the first refrigerant flow path does not participate in the refrigeration cycle. The third state is a state in which the amount of refrigerant participating in the refrigeration cycle is moderate, and the first conducting state is to connect the first end and the third end of the three-way valve.

10. The control method for a heat pump system according to any one of claims 2 to 9, wherein, Determining the current refrigerant state based on at least one of the subcooling and superheat of the heat pump system includes: If the superheat of the heat pump system is less than the first superheat threshold, the current refrigerant state is determined to be the first state. When the superheat of the heat pump system is greater than the second superheat threshold and the exhaust temperature of the heat pump system is greater than the exhaust temperature threshold, the current refrigerant state is determined to be the second state, where the second superheat threshold is greater than the first superheat threshold. When the superheat of the heat pump system is greater than or equal to the third superheat threshold and less than or equal to the fourth superheat threshold, the current refrigerant state is determined to be the third state, wherein the third superheat threshold is greater than the first superheat threshold and the fourth superheat threshold is less than the second superheat threshold.

11. The control method for a heat pump system according to any one of claims 2 to 9, wherein, Determining the current refrigerant state based on at least one of the subcooling and superheat of the heat pump system includes: If the subcooling of the heat pump system is greater than the first subcooling threshold, the current refrigerant state is determined to be the first state. When the subcooling of the heat pump system is less than the second subcooling threshold and the exhaust temperature of the heat pump system is greater than the exhaust temperature threshold, the current refrigerant state is determined to be the second state, where the second subcooling threshold is less than the first subcooling threshold. When the subcooling of the heat pump system is greater than or equal to the third subcooling threshold and less than or equal to the fourth subcooling threshold, the current refrigerant state is determined to be the third state, wherein the third subcooling threshold is greater than the second subcooling threshold and the fourth subcooling threshold is less than the first subcooling threshold.

12. The control method for a heat pump system according to any one of claims 1 to 9, wherein, Determining at least one of the subcooling and superheat of the heat pump system includes: Obtain the pressure measurement value at the compressor intake port and the temperature measurement value at the compressor intake port; The saturated evaporation temperature is determined based on the pressure measurement value at the compressor's suction port. The superheat is determined based on the measured temperature at the compressor intake port and the saturated evaporation temperature.

13. The control method for a heat pump system according to any one of claims 1 to 9, wherein, Determining at least one of the subcooling and superheat of the heat pump system includes: Obtain the pressure measurement value at the outlet of the indoor heat exchanger and the temperature measurement value at the outlet of the indoor heat exchanger; The saturated condensation temperature is determined based on the pressure measurement at the outlet of the indoor heat exchanger. The subcooling degree is determined based on the measured temperature at the outlet of the indoor heat exchanger and the saturated condensation temperature.

14. A controller, comprising: A module for performing the control method of the heat pump system as described in any one of claims 1 to 13.

15. A controller, comprising: Memory; as well as A processor coupled to the memory, the processor being configured to execute a control method for a heat pump system as described in any one of claims 1 to 13, based on instructions stored in the memory.

16. A heat pump system, comprising: The main refrigerant circulation path includes a compressor, an outdoor heat exchanger, an indoor heat exchanger, and a gas-liquid separator connected in series. The first refrigerant flow path is connected in parallel with the pipeline section where the outdoor heat exchanger is located in the main refrigerant circulation flow path, and includes a heat collection component and a first throttling component; The first regulating valve is connected to the main refrigerant circulation path and the first refrigerant path respectively, and is connected to the gas-liquid separator through the second refrigerant path; The controller is configured to, in cooling mode, determine at least one of the subcooling and superheat of the heat pump system; and, based on at least one of the subcooling and superheat of the heat pump system, regulate the first regulating valve and the first throttling component to adjust the amount of refrigerant participating in the refrigeration cycle in the heat pump system.

17. The heat pump system according to claim 16, wherein, The first regulating valve is a three-way valve. The first end of the three-way valve is connected to the main refrigerant circulation path, the second end of the three-way valve is connected to the second refrigerant path, and the third end of the three-way valve is connected to the first refrigerant path.

18. The heat pump system according to claim 16, wherein, The controller adjusts the first regulating valve and the first throttling component according to the superheat and exhaust temperature of the heat pump system. The heat pump system further includes: The first temperature sensor is used to collect the temperature measurement value of the compressor's air intake port; A first pressure sensor is used to collect the pressure measurement value of the compressor suction port, wherein the temperature measurement value of the compressor suction port and the pressure measurement value of the compressor suction port are used to determine the superheat. The second temperature sensor is used to collect the exhaust temperature.

19. The heat pump system according to claim 16, wherein, The controller adjusts the first regulating valve and the first throttling component according to the subcooling and exhaust temperature of the heat pump system. The heat pump system further includes: The third temperature sensor is used to collect the temperature measurement value at the outlet of the indoor heat exchanger; The second pressure sensor is used to collect the pressure measurement value at the outlet of the indoor heat exchanger, wherein the temperature measurement value at the outlet of the indoor heat exchanger and the pressure measurement value at the outlet of the indoor heat exchanger are used to determine the subcooling. The second temperature sensor is used to collect the exhaust temperature.

20. The heat pump system according to any one of claims 16 to 19, wherein, The heat collection component is a photovoltaic thermal component, and the heat pump system is a photovoltaic thermal heat pump system.

21. A computer-readable storage medium having stored thereon computer program instructions that, when executed by a processor, implement the control method of a heat pump system as described in any one of claims 1 to 13.

22. A computer program product having stored computer program instructions thereon, which, when executed by a processor, implement the control method of the heat pump system as described in any one of claims 1 to 13.

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