Heat pump unit control method

Abstract

The present application relates to the technical field of heat pumps, and provides a heat pump unit control method. The method comprises: when an operation-pending mode of a heat pump unit is set to a heating plus domestic hot water mode, determining a target operation mode of the heat pump unit according to a first demand determination strategy, wherein the target operation mode comprises any one of a heating mode, the heating plus domestic hot water mode and a domestic hot water mode; and then, the heat pump unit calculating a target output frequency in the target operation mode on the basis of a pre-stored capability calculation mapping table, and controlling a compressor to operate according to the target output frequency. The present application prevents a heat pump unit from being directly controlled to operate at a high frequency in a heating plus domestic hot water mode, which otherwise results in excessive energy consumption during operation, thereby improving the operation efficiency of the heat pump unit.

Description

Control method of heat pump unit

[0001] This application claims priority to the Chinese patent application filed with the China Patent Office on October 31, 2023, with application number 202311444016.7 and invention name “Control Method for Heat Pump Unit”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present application relates to the technical field of heat pumps, and in particular to a control method for a heat pump unit. Background Art

[0003] Traditional air conditioning and hot water systems use separate equipment, making it difficult to effectively utilize energy. With the development of heat pump technology and the need for environmental protection, heat pump units that can operate both heating and domestic hot water functions simultaneously, more efficiently utilize renewable energy, and have lower carbon emissions, are becoming increasingly popular.

[0004] When traditional heat pump units provide heating and domestic hot water functions, they are usually directly controlled to operate in a high-frequency heating and domestic hot water mode, resulting in excessive energy consumption during operation.

[0005] Summary of the Invention

[0006] In view of this, the present application provides a control method for a heat pump unit to solve the problem of excessive energy consumption during the operation of the heat pump unit in heating and domestic hot water mode.

[0007] A first aspect of an embodiment of the present application provides a control method for a heat pump unit, wherein the heat pump unit includes a compressor, and the control method for the heat pump unit includes: setting the standby operating mode of the heat pump unit to a heating plus domestic hot water mode; determining a target operating mode of the heat pump unit according to a first demand judgment strategy, wherein the target operating mode includes any one of a heating mode, a heating plus domestic hot water mode, and a domestic hot water mode; calculating a target output frequency under the target operating mode based on a pre-stored capacity calculation mapping table, and controlling the compressor to operate according to the target output frequency.

[0008] In some embodiments, the target operating mode of the heat pump unit is determined according to the first demand judgment strategy, including: if the heat pump unit has a first heating demand, and the hot water temperature, hot water inlet temperature and exhaust temperature of the heat pump unit all meet the first condition, determining that the target operating mode is a heating plus domestic hot water mode; if the heat pump unit has the first heating demand, and the hot water temperature and the hot water inlet temperature both meet the second condition, determining that the target operating mode is a domestic hot water mode.

[0009] In some embodiments, determining the target operating mode of the heat pump unit according to the first demand judgment strategy includes: if the heat pump unit does not have the first heating demand, and the hot water temperature and the hot water inlet temperature both meet the third condition, determining that the target operating mode is the domestic hot water mode.

[0010] In some embodiments, the control method also includes: obtaining the air-conditioning side water outlet temperature of the heat pump unit; if the air-conditioning side water outlet temperature is greater than the difference between the heating target temperature and the start-up temperature difference within a first time period, determining that the heat pump unit does not have the first heating demand; if the air-conditioning side water outlet temperature is less than or equal to the difference between the heating target temperature and the start-up temperature difference within the first time period, determining that the heat pump unit has the first heating demand.

[0011] In some embodiments, the target output frequency under the target operating mode is calculated based on a pre-stored capacity calculation mapping table, including: if it is determined that the target operating mode is the heating mode or the heating plus domestic hot water mode, obtaining the air-conditioning side outlet water temperature and the heating target temperature of the heat pump unit in the current operating cycle; determining the target temperature difference based on the air-conditioning side outlet water temperature and the heating target temperature; determining the target temperature difference change rate based on the target temperature difference and the historical temperature difference, the historical temperature difference being the temperature difference in the previous operating cycle of the current operating cycle; matching the target frequency adjustment parameter from the capacity calculation mapping table based on the target temperature difference and the target temperature difference change rate; and calculating the target output frequency of the compressor in the current operating cycle based on the target frequency adjustment parameter and the historical output frequency of the compressor in the previous operating cycle.

[0012] In some embodiments, the control method also includes: switching the target operating mode according to a second demand judgment strategy, the target operating mode including any one of heating mode, heating plus domestic hot water mode, domestic hot water mode, standby mode, alarm shutdown mode and electric heating mode.

[0013] In some embodiments, switching the target operating mode according to the second demand judgment strategy includes: switching the target operating mode of the heat pump unit if any of the following conditions is met: the hot water inlet temperature of the heat pump unit is greater than the first temperature threshold; the heat pump unit does not have a second heating demand; within a preset time period, the difference between the exhaust temperature and the hot water inlet temperature is less than the second temperature threshold.

[0014] In some embodiments, the control method also includes: obtaining the air-conditioning side water outlet temperature of the heat pump unit; if the air-conditioning side water outlet temperature is greater than the sum of the heating target temperature and the shutdown temperature difference within the second time period, determining that the heat pump unit does not have the second heating demand; if the air-conditioning side water outlet temperature is less than or equal to the sum of the heating target temperature and the shutdown temperature difference within the second time period, determining that the heat pump unit has the second heating demand.

[0015] In some embodiments, switching the target operating mode according to the second demand judgment strategy includes: when the heat pump unit is operating in the heating plus domestic hot water mode, if the hot water temperature is less than the third temperature threshold, switching the target operating mode to the domestic hot water mode; when the heat pump unit is operating in the domestic hot water mode, if the hot water temperature is greater than or equal to the fourth temperature threshold, and the heat pump has the second heating demand, switching the target operating mode to the heating plus domestic hot water mode; if the hot water temperature is less than the fifth temperature threshold, switching the target operating mode to the electric heating mode.

[0016] In some embodiments, the heat pump unit includes a first valve and a second valve, and the control method further includes: if the target operating mode is a domestic hot water mode, setting the first valve and the second valve to be open; if the target operating mode is a heating mode, setting the first valve to be closed and the second valve to be open; if the target operating mode is a heating plus domestic water mode, setting the first valve to be open and the second valve to be closed.

[0017] A second aspect of an embodiment of the present application provides a control device for a heat pump unit, wherein the heat pump unit includes a compressor, and the control device includes: a setting module for setting the standby operating mode of the heat pump unit to a heating plus domestic hot water mode; a determination module for determining a target operating mode of the heat pump unit according to a first demand judgment strategy, wherein the target operating mode includes any one of a heating mode, a heating plus domestic hot water mode, and a domestic hot water mode; a control module for calculating a target output frequency under the target operating mode based on a pre-stored capacity calculation mapping table, and controlling the compressor to operate according to the target output frequency.

[0018] A third aspect of an embodiment of the present application provides a heat pump unit, comprising a memory, a processor, and computer-readable instructions stored in the memory and executable on the processor, wherein the processor implements the control method of the heat pump unit when executing the computer-readable instructions.

[0019] A fourth aspect of an embodiment of the present application provides a computer-readable storage medium, wherein the computer-readable storage medium stores computer-readable instructions, and when the computer-readable instructions are executed by a processor, the control method of the heat pump unit is implemented.

[0020] In a control method for a heat pump unit provided in an embodiment of the present application, when the standby operating mode of the heat pump unit is set to the heating plus domestic hot water mode, the target operating mode of the heat pump unit is determined according to a first demand judgment strategy, wherein the target operating mode includes any one of the heating mode, the heating plus domestic hot water mode, and the domestic hot water mode. The heat pump unit then calculates the target output frequency under the target operating mode based on a pre-stored capacity calculation mapping table, and controls the compressor to operate according to the target output frequency. The present application avoids directly controlling the heat pump unit to operate in the heating plus domestic hot water mode at a high frequency, which results in excessive energy consumption during operation, thereby improving the operating efficiency of the heat pump unit. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments of the present application. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0022] FIG1 is an example diagram of refrigerant operation in a heating and domestic hot water mode provided in an embodiment of the present application;

[0023] FIG2 is a flow chart of a control method for a heat pump unit according to an embodiment of the present application;

[0024] FIG3 is an example diagram of the control principle of the control method of the heat pump unit provided in an embodiment of the present application;

[0025] FIG4 is a schematic structural diagram of a control device for a heat pump unit provided in an embodiment of the present application;

[0026] FIG5 is a schematic structural diagram of a heat pump unit provided in an embodiment of the present application.

[0027] Main component symbols: heat pump unit-100; compressor-101; domestic hot water heat exchanger-102; enthalpy increase module-103; first throttling element 1031; economizer 1032; second throttling element 1033; evaporator-104; air conditioning side heat exchanger-105; domestic hot water tank-10; liquid storage tank-20; gas-liquid separator-30; air conditioning tank-40; first three-way valve-50; first interface 501 of the first three-way valve; first The second interface 502 of the three-way valve; the third interface 503 of the first three-way valve; the second three-way valve-51; the first interface 511 of the second three-way valve; the second interface 512 of the second three-way valve; the third interface 513 of the second three-way valve; the four-way valve-60; the first temperature sensor-70; the second temperature sensor-71; the third temperature sensor-72; the fourth temperature sensor-73; several one-way valves-80~86; the first water pump-90; the second water pump-91. DETAILED DESCRIPTION

[0028] It should be noted that the terms "first" and "second" in the description, claims and drawings of this application are used to distinguish similar objects, rather than to describe a specific order or sequence.

[0029] It should also be noted that the method disclosed in the embodiments of the present application or the method shown in the flowchart includes one or more steps for implementing the method. Without departing from the scope of the claims, the execution order of multiple steps can be interchanged with each other, and some steps can also be deleted.

[0030] The following will describe some embodiments with reference to the accompanying drawings. In the absence of conflict, the following embodiments and features therein may be combined with each other.

[0031] In some embodiments, the heat pump system is a whole system composed of a heat pump unit, a terminal water system, etc. Among them, the heat pump unit is the most core part of the heat pump system, responsible for the transfer and conversion of heat energy. The heat pump unit is usually composed of a compressor, a condenser, an evaporator, a throttling device (for example, an expansion valve), a refrigerant pipeline, a liquid storage tank, a gas-liquid separator, a domestic hot water tank and other equipment. The heat pump unit can achieve a variety of operating modes, such as domestic hot water mode, cooling mode, heating mode, cooling plus domestic hot water mode, heating plus domestic hot water mode, etc. An embodiment of the present application provides a method for controlling a heat pump unit when the standby operating mode of the heat pump unit is set to heating plus domestic hot water mode.

[0032] In some embodiments, the heat pump unit may further include a control device, through which the heat pump unit can control the operating mode, the output frequency of the compressor, temperature detection, etc.

[0033] In the embodiment provided in the present application, when the operating mode of the heat pump unit is the heating plus domestic hot water mode, the heat pump unit absorbs heat from the low-temperature renewable energy and uses it for heating and preparing domestic hot water. During the operation of the heating plus domestic hot water mode, the high-temperature refrigerant processed by the compressor flows through the domestic hot water heat exchanger and the air-conditioning side heat exchanger in turn. Among them, when the high-temperature refrigerant flows through the domestic hot water heat exchanger, the domestic hot water heat exchanger and the domestic hot water tank exchange heat to achieve the preparation of domestic hot water; when the high-temperature refrigerant flows through the air-conditioning panel exchanger, the air-conditioning side heat exchanger exchanges heat with the air-conditioning water tank, wherein the air-conditioning water tank can be connected to floor heating or fan coil units, etc., to achieve heating.

[0034] Please refer to Figure 1, which is an example diagram of the refrigerant operation of the heating and domestic hot water mode provided in the embodiment of the present application, wherein Figure 1 shows an example diagram of the partial structure of the heat pump unit provided in the embodiment of the present application. As shown in Figure 1, the heat pump unit 100 includes core equipment such as a compressor 101, a domestic hot water heat exchanger 102, an enthalpy increase module 103, an evaporator 104, and an air-conditioning side heat exchanger 105 (i.e., a condenser). In addition, the heat pump unit 100 also includes auxiliary equipment such as a domestic hot water tank 10, a liquid storage tank 20, a gas-liquid separator 30, a first water pump 90, a second water pump 91, a first temperature sensor 70, a second temperature sensor 71, a third temperature sensor 72, and a fourth temperature sensor 73, as well as components such as a first three-way valve 50, a second three-way valve 51, a four-way valve 60, and several one-way valves 80 to 86, wherein the air-conditioning side heat exchanger 105 is connected to the terminal water system (such as the air-conditioning water tank 40, etc.).

[0035] In some embodiments, the various devices and components in the heat pump unit 100 can be connected via pipes. For example, the compressor 101 and the domestic hot water heat exchanger 102 are connected via a refrigerant pipe, the domestic hot water heat exchanger 102 and the domestic hot water tank 10 can be connected via a hot water pipe, and the air conditioning side heat exchanger 105 and the air conditioning tank 40 can be connected via a condensing pipe.

[0036] In some embodiments, the compressor 101 is used to compress low-temperature, low-pressure gaseous refrigerant into high-temperature, high-pressure gaseous refrigerant. The domestic hot water heat exchanger 102 is used to perform heat exchange with the domestic hot water tank 10, heating the water in the domestic hot water tank 10 to produce domestic hot water. The enthalpy increase module 103 may, for example, include an economizer 1032, a first throttling element 1031, and a second throttling element 1033. The economizer 1032, the first throttling element 1031, and the second throttling element 1033 work together to achieve an enthalpy increase effect. The economizer 1032 is used to recover waste heat from the refrigerant. The first throttling element 1031 and the second throttling element 1033 can achieve a throttling effect by limiting the cross-sectional area of ​​the refrigerant flow. Therefore, the economizer 1032, the first throttling element 1031, and the second throttling element 1033 together can achieve the functions of the enthalpy increase module 103. The evaporator 104 is used to absorb heat from external renewable energy, causing the refrigerant flowing into the evaporator 104 to evaporate into a low-temperature gaseous refrigerant. The low-temperature gaseous refrigerant is sucked into the compressor 101, and a high-temperature and high-pressure gaseous refrigerant is output. The air-conditioning side heat exchanger 105 can be a condenser. The high-temperature and high-pressure gaseous refrigerant flows through the air-conditioning side heat exchanger 105 to exchange heat with the air-conditioning water tank 40, heating the water in the air-conditioning water tank 40, and at the same time cooling the high-temperature and high-pressure gaseous refrigerant into a liquid refrigerant. The liquid storage tank 20 can be used to store liquid refrigerant and balance the pressure of the heat pump unit 100. The gas-liquid separator 30 can store part of the refrigerant in the system to prevent compressor liquid shock and excessive refrigerant from diluting the compressor oil.

[0037] In some embodiments, as shown in Figure 1, a first temperature sensor 70 is used to detect exhaust temperature AI1, a second temperature sensor 71 is used to detect hot water temperature AI2, a third temperature sensor 72 is used to detect hot water inlet temperature AI3, and a fourth temperature sensor 73 is used to detect air conditioning side water outlet temperature AI4. The first three-way valve 50 is provided with a first port 501, a second port 502, and a third port 503 of the first three-way valve, and the second three-way valve 51 is provided with a first port 511, a second port 512, and a third port 513 of the second three-way valve. The second port 502 of the first three-way valve 50 and the third port 503 of the first three-way valve 50 connect the refrigerant pipeline between the domestic hot water heat exchanger 102 and the exhaust port of the compressor 101. The first port 501 of the first three-way valve 50 and the third port 503 of the first three-way valve 50 connect the refrigerant pipeline between the four-way valve 60 and the exhaust port of the compressor 101. The first port 511 of the second three-way valve 51 and the third port 513 of the second three-way valve 51 connect the refrigerant pipeline between the domestic hot water heat exchanger 102 and the four-way valve 60. The third port 513 of the second three-way valve 51 and the second port 512 of the second three-way valve 51 connect the refrigerant pipeline between the air conditioning side heat exchanger 105 and the domestic hot water heat exchanger 102. In addition, the multiple one-way valves 80-86 in the heat pump unit 100 can be used to control the forward and reverse flow of the refrigerant, so that the refrigerant can only flow in a specific direction. The first water pump 90 between the domestic hot water heat exchanger 102 and the domestic hot water tank 10 can be used to circulate water between the domestic hot water heat exchanger 102 and the domestic hot water tank 10 to achieve heat transfer. The second water pump 91 between the air conditioning side heat exchanger 105 and the air conditioning water tank 40 can be used to circulate water between the air conditioning side heat exchanger 105 and the air conditioning water tank 40 to achieve heat transfer.

[0038] In some embodiments, the second port 502 and the third port 503 of the first three-way valve 50 are open, and the first port 501 of the first three-way valve 50 is closed, which is referred to as opening the first three-way valve 50; the first port 501 and the third port 503 of the first three-way valve 50 are open, and the second port 502 of the first three-way valve 50 is closed, which is referred to as closing the first three-way valve 50. Similarly, the second port 512 and the third port 513 of the second three-way valve 51 are open, and the first port 511 of the second three-way valve 51 is closed, which is referred to as opening the second three-way valve 51; the first port 511 and the third port 513 of the second three-way valve 51 are open, and the second port 512 of the second three-way valve 51 is closed, which is referred to as closing the second three-way valve 51.

[0039] In some embodiments, when the heat pump unit 100 is performing heating and preparing domestic hot water, the first three-way valve 50 is set to open, the second three-way valve 51 is set to closed, and the refrigerant flows in the direction indicated by the arrows in Figure 1. At this time, the high-temperature, high-pressure gaseous refrigerant discharged from the compressor 101 flows through the second port 502 and the third port 503 of the first three-way valve 50 into the domestic hot water heat exchanger 102. The domestic hot water heat exchanger 102 is connected to the domestic hot water tank 10. As the high-temperature, high-pressure gaseous refrigerant flows through the domestic hot water heat exchanger 102, it exchanges heat with the water in the domestic hot water tank 10, heating the water therein and thus preparing domestic hot water. The refrigerant flowing out of the domestic hot water heat exchanger 102 flows into the air conditioning side heat exchanger 105, exchanging heat with the air conditioning tank 40 connected to the air conditioning side heat exchanger 105, heating the water therein to form high-temperature water. This heat exchanges heat with the air inside the high-temperature water room, raising the indoor air temperature and thus achieving the heating function. At the same time, the refrigerant flowing into the air-conditioning heat exchanger 105 is cooled to a liquid state. The liquid refrigerant flowing out of the air-conditioning heat exchanger 105 passes through the liquid storage tank 20, the economizer 1032 in the enthalpy increase module 103, and the first throttling element 1031, forming a low-temperature liquid refrigerant. The low-temperature liquid refrigerant then flows into the evaporator 104, which absorbs heat from external renewable energy sources, evaporating the low-temperature liquid refrigerant into a gaseous refrigerant. The gaseous refrigerant passes through the four-way valve and is drawn into the compressor, completing the heating and domestic hot water cycle.

[0040] In some embodiments, the heat pump unit 100 may further include components such as a filter, a high-pressure sensor, a high-pressure protection switch, and a low-pressure sensor. The filter can be used to filter and remove impurities, contaminants, and solid particles from the refrigerant. The high-pressure sensor can be used to measure the high pressure of the heat pump unit. The high-pressure protection switch can be used to monitor the high pressure of the heat pump unit. When the high pressure exceeds a set safety range, the high-pressure protection switch automatically disconnects the circuit to prevent a possible dangerous situation. The low-pressure sensor can be used to measure the low pressure of the heat pump unit.

[0041] Please refer to Figure 2, which is a flowchart of the implementation of the control method of the heat pump unit provided in an embodiment of the present application. The embodiment of the present application takes the application of this method to the heat pump unit 100 in Figure 1 as an example to illustrate, and includes the following steps.

[0042] S11: The standby mode of the heat pump unit is set to the heating plus domestic hot water mode.

[0043] In some embodiments, the standby operation modes of the heat pump include but are not limited to heating mode, cooling mode, domestic hot water mode, cooling plus domestic hot water mode, and heating plus domestic hot water mode.

[0044] In some embodiments, a user can select a standby operating mode for the heat pump unit. For example, for a heat pump unit in an air conditioner, a display on the air conditioner can display various standby operating mode options for the air conditioner, such as a domestic hot water mode option, a cooling mode option, a heating mode option, a cooling plus domestic hot water mode option, a heating plus domestic hot water mode option, etc. In response to a user selecting the domestic hot water mode option and the heating mode option, or in response to a user selecting the heating plus domestic hot water mode option, the heat pump unit can determine that the standby operating mode of the heat pump unit is the heating plus domestic hot water mode.

[0045] S12: Determine a target operating mode of the heat pump unit according to the first demand judgment strategy.

[0046] In some embodiments, the first demand determination strategy is to determine corresponding conditions of a target operating mode, wherein the target operating mode includes but is not limited to any one of a heating mode, a heating plus domestic hot water mode, and a domestic hot water mode.

[0047] In some embodiments, when the heat pump unit's standby operating mode is determined to be the heating plus domestic hot water mode, this indicates that the user has a demand for both heating and domestic hot water. However, the heating function currently provided by the heat pump unit may already meet the user's heating demand, or the domestic hot water currently produced by the heat pump unit may already meet the user's domestic hot water demand, or the heating function currently provided by the heat pump unit may not meet the user's heating demand, or the domestic hot water currently produced by the heat pump unit may not meet the user's domestic hot water demand. In this case, continuing to control the heat pump unit to operate in the heating plus domestic hot water mode may result in energy waste and increase operating costs. To avoid this situation, the heat pump unit may further determine a target operating mode for the heat pump unit when determining that the heat pump's standby operating mode is the heating plus domestic hot water mode. The target operating mode may be one of the following modes: heating plus domestic hot water mode, heating mode, domestic hot water mode, standby mode, electric heating mode, etc. By controlling the heat pump unit to operate according to the target operating mode, energy utilization efficiency can be improved.

[0048] In some embodiments of the present application, the target operating mode of the heat pump unit is determined according to the first demand judgment strategy, including: if the heat pump unit has a first heating demand, and the hot water temperature, hot water inlet temperature and exhaust temperature of the heat pump unit all meet the first condition, the target operating mode is determined to be the heating plus domestic hot water mode; if the heat pump unit has a first heating demand, and the hot water temperature and the hot water inlet temperature both meet the second condition, the target operating mode is determined to be the domestic hot water mode; if the heat pump unit has a first heating demand, the hot water temperature, hot water inlet temperature and exhaust temperature do not meet the first condition, and the hot water temperature and hot water inlet temperature do not meet the second condition, the target operating mode is determined to be the heating mode.

[0049] In some embodiments, in the process of determining the target operating mode of the heat pump unit, the heat pump unit determines the target operating mode of the heat pump unit by determining whether the heating function currently provided by the heat pump unit meets the user's demand for heating, and further determines whether the domestic hot water currently prepared by the heat pump unit meets the user's demand for domestic hot water.

[0050] In some embodiments, the presence of a first heating demand by the heat pump unit indicates that the current heating function provided by the heat pump unit cannot meet the user's heating demand, and the heat pump unit may need to be activated to meet the user's heating demand. To determine the target operating mode of the heat pump unit, it is also necessary to further determine whether the domestic hot water currently produced by the heat pump unit meets the user's domestic hot water demand.

[0051] In some embodiments, as shown in FIG. 1 , the heat pump unit may detect the exhaust temperature AI1 through a first temperature sensor 70 , detect the hot water temperature AI2 through a second temperature sensor 71 , and detect the hot water inlet temperature AI3 through a third temperature sensor 72 .

[0052] In some embodiments, when it is determined that the heat pump unit has a first heating demand and the hot water temperature, hot water inlet temperature, and exhaust temperature of the heat pump unit all meet the first condition, the heat pump unit can determine that the target operating mode is the heating plus domestic hot water mode. As an example, the hot water temperature, hot water inlet temperature, and exhaust temperature of the heat pump unit all meet the first condition, including: the hot water temperature is less than a first threshold, the hot water inlet temperature is less than a second threshold, and the exhaust temperature is greater than the sum of the hot water inlet temperature and the first temperature parameter within a certain time period. Among them, the first threshold, the second threshold, the certain time period, and the first temperature parameter can all be customized. For example, the first threshold can be set to 65°C, the second threshold can be set to 60°C, the certain time period can be set to 3 seconds, and the first temperature parameter can be set to 8°C.

[0053] In some embodiments, when it is determined that the heat pump unit has a first heating demand, and the hot water temperature and hot water inlet temperature of the heat pump unit both meet the second condition, it means that the domestic hot water currently prepared by the heat pump unit is far from meeting the user's demand for domestic hot water. Therefore, the heat pump unit can determine that the target operating mode is the domestic hot water mode. As an example, the hot water temperature and hot water inlet temperature of the heat pump unit both meet the second condition, including: the hot water temperature is less than the third threshold, the hot water inlet temperature is less than the fourth threshold, and the hot water inlet temperature is less than the difference between the maximum heating outlet water temperature and the second temperature parameter. Among them, the third threshold, the fourth threshold and the second temperature parameter can all be customized. For example, the third threshold can be set to 57°C, the fourth threshold can be set to 52°C, and the second temperature parameter can be set to 8°C. For the maximum heating outlet water temperature, it can be obtained by querying the relevant parameters provided in the product specifications and technical documents related to the heat pump unit.

[0054] In some embodiments, when it is determined that the heat pump unit has a first heating demand, and the hot water temperature, hot water inlet temperature, and exhaust temperature of the heat pump unit do not meet a first condition, and the hot water temperature and hot water inlet temperature of the heat pump unit do not meet a second condition, the heat pump unit may determine that the target operating mode is the heating mode. Wherein, the hot water temperature, hot water inlet temperature, and exhaust temperature of the heat pump unit do not meet the first condition include: the hot water temperature is greater than or equal to a first threshold, or the hot water inlet temperature is greater than or equal to a second threshold, or the exhaust temperature is less than or equal to the sum of the hot water inlet temperature and the first temperature parameter for a certain period of time. Where the hot water temperature and hot water inlet temperature of the heat pump unit do not meet the second condition include: the hot water temperature is greater than or equal to a third threshold, or the hot water inlet temperature is greater than or equal to a fourth threshold, or the hot water inlet temperature is greater than or equal to the difference between the maximum heating outlet water temperature and the second temperature parameter.

[0055] In some embodiments of the present application, the target operating mode of the heat pump unit is determined according to the first demand judgment strategy, including: if the heat pump unit does not have the first heating demand, and the hot water temperature and the hot water inlet temperature both meet the third condition, determining that the target operating mode is the domestic hot water mode.

[0056] In some embodiments, the absence of the first heating demand by the heat pump unit indicates that the heating function currently provided by the heat pump unit can meet the user's heating demand, and there is no need to start the heat pump unit for heating. In this case, to determine the target operating mode of the heat pump unit, it is necessary to further determine whether the domestic hot water currently produced by the heat pump unit meets the user's domestic hot water demand.

[0057] In some embodiments, when it is determined that the heat pump unit does not have the first heating demand, and it is determined that the hot water temperature and the hot water inlet temperature of the heat pump unit both meet the third condition, it can be determined that the domestic hot water produced by the current heat pump unit cannot meet the user's demand for domestic hot water. At this time, the heat pump unit can determine that the target operating mode is the domestic hot water mode. As an example, the hot water temperature and the hot water inlet temperature of the heat pump unit both meet the third condition, including: the hot water temperature is less than the fifth threshold, the hot water inlet temperature is less than the sixth threshold, and the hot water inlet temperature is less than the difference between the maximum heating outlet water temperature and the third temperature parameter. Among them, the fifth threshold, the sixth threshold, and the third temperature parameter can all be customized. For example, the fifth threshold can be set to 55°C, the sixth threshold can be set to 50°C, and the third temperature parameter can be set to 10°C.

[0058] In some embodiments of the present application, determining whether the heat pump unit has a first heating demand can be performed by obtaining the air-conditioning-side outlet water temperature of the heat pump unit. Specifically, the heat pump unit obtains the air-conditioning-side outlet water temperature; if the air-conditioning-side outlet water temperature is greater than the difference between the heating target temperature and the startup temperature difference within a first time period, determining that the heat pump unit does not have the first heating demand; if the air-conditioning-side outlet water temperature is less than or equal to the difference between the heating target temperature and the startup temperature difference within the first time period, determining that the heat pump unit has a first heating demand.

[0059] In some embodiments, as shown in FIG1 , the heat pump unit can detect the air-conditioning side outlet water temperature AI4 via a fourth temperature sensor 73. The heating target temperature can be customized, and the startup temperature difference can be determined based on the temperature difference between the indoor and outdoor ambient temperatures at startup, the operating efficiency of the heat pump unit, the equipment capacity, and other factors.

[0060] In some embodiments, when the outlet water temperature on the air conditioner side is greater than the difference between the heating target temperature and the start-up temperature difference during the first time period, it indicates that the heating function provided by the current heat pump unit can meet the user's heating demand, that is, the heat pump unit does not have the first heating demand at this time. When the outlet water temperature on the air conditioner side is less than or equal to the difference between the heating target temperature and the start-up temperature difference during the first time period, it indicates that the heating function provided by the current heat pump unit cannot meet the user's heating demand, that is, the heat pump unit has the first heating demand at this time.

[0061] S13: Calculating a target output frequency in a target operation mode based on a pre-stored capacity calculation mapping table, and controlling the compressor to operate according to the target output frequency.

[0062] In some embodiments, different target operating modes correspond to different capacity calculation mapping tables. When the target operating mode is heating mode or heating plus domestic hot water mode, the pre-stored capacity calculation mapping table includes a preset plurality of sets of temperature difference ranges, a plurality of sets of temperature difference change rate ranges, and the correspondence between the temperature difference range, the temperature difference change rate range, and the frequency adjustment parameter. In particular, when the heat pump unit operates in domestic hot water mode, heating mode, or heating plus domestic hot water mode, it is in a periodic cycle, such as a heating cycle. Therefore, the output frequency of the compressor in the heat pump unit also changes periodically. In particular, the temperature difference can be determined based on the air conditioning side outlet water temperature and the heating target temperature of the heat pump unit in an operating cycle. The temperature difference change rate is used to characterize the temperature difference change between adjacent operating cycles. For example, the change in the temperature difference of the current operating cycle relative to the temperature difference of the previous operating cycle can be determined by calculating the difference between the temperature difference of the previous operating cycle and the temperature difference of the current operating cycle.

[0063] In some embodiments, the target output frequency refers to the output frequency of the compressor in the current operation cycle.

[0064] In some embodiments, when the target operating mode is domestic hot water mode, the pre-stored capacity calculation mapping table includes a subcooling threshold range and a corresponding relationship between the subcooling threshold range and the compressor frequency adjustment parameter. In this case, the heat pump unit can first obtain the subcooling of the heat pump unit in the current operating cycle, determine the subcooling threshold range within which the subcooling falls, and then determine the target frequency adjustment parameter for the current operating cycle based on the corresponding relationship between the subcooling threshold range and the compressor frequency adjustment parameter in the pre-stored capacity calculation mapping table. The target output frequency of the compressor in the current operating cycle is thereby determined based on the target frequency adjustment parameter. In some embodiments, determining the target output frequency of the compressor in the current operating cycle based on the target frequency adjustment parameter includes: obtaining the historical output frequency of the compressor in the previous operating cycle; and using the sum of the historical output frequency and the target frequency adjustment parameter as the target output frequency of the compressor in the current operating cycle.

[0065] In some embodiments, after determining the target output frequency of the compressor in the current operation cycle, the heat pump unit can control the compressor to operate in a target operation mode according to the target output frequency.

[0066] In some embodiments, the heat pump unit can pre-establish a correspondence between the target operating mode and the capacity calculation mapping table. After determining the target operating mode of the heat pump unit according to the first demand judgment strategy, the heat pump unit can determine the capacity calculation mapping table corresponding to the target operating mode based on the correspondence between the target operating mode and the capacity calculation mapping table. The target output frequency for the target operating mode can then be calculated based on the corresponding capacity calculation mapping table, and the compressor can be controlled to operate at the target output frequency. This embodiment of the present application primarily describes how to determine the target output frequency of the compressor in the current operating cycle when in heating mode or heating plus domestic hot water mode.

[0067] In some embodiments of the present application, the target output frequency in the target operating mode is calculated based on a pre-stored capacity calculation mapping table, including: if the target operating mode is determined to be a heating mode or a heating plus domestic hot water mode, obtaining the air-conditioning side outlet water temperature and the heating target temperature of the heat pump unit in the current operating cycle; determining the target temperature difference based on the air-conditioning side outlet water temperature and the heating target temperature; determining the target temperature difference change rate based on the target temperature difference and the historical temperature difference, the historical temperature difference being the temperature difference of the previous operating cycle of the current operating cycle; matching the target frequency adjustment parameters from the capacity calculation mapping table based on the target temperature difference and the target temperature difference change rate; and calculating the target output frequency of the compressor in the current operating cycle based on the target frequency adjustment parameters and the historical output frequency of the compressor in the previous operating cycle.

[0068] In some embodiments, when the target operating mode is a heating mode or a heating plus domestic hot water mode, the pre-stored capacity calculation mapping table includes a preset plurality of sets of temperature difference ranges, a plurality of sets of temperature difference change rate ranges, and the correspondence between the temperature difference ranges, the temperature difference change rate ranges, and the frequency adjustment parameters. The target temperature difference represents the heating temperature difference of the current operating cycle. The target temperature difference change rate table shows the change in the temperature difference of the current operating cycle relative to the temperature difference of the previous operating cycle of the current operating cycle. The target output frequency of the compressor refers to the output frequency of the compressor in the current operating cycle. Among them, the operating cycle can be customized, for example, it can be set to 30 seconds. The plurality of sets of temperature difference ranges, the plurality of sets of temperature difference change rate ranges, and the corresponding frequency adjustment parameters in the pre-stored capacity calculation mapping table can be customized.

[0069] In some embodiments, when the target operating mode is determined to be a heating mode or a heating plus domestic hot water mode, the heat pump unit can determine the target output frequency of the compressor in the heat pump unit in the current operating cycle according to the formula u(k)=u(k-1)+△u(k). In the formula, u(k) represents the target output frequency of the compressor; u(k-1) represents the historical output frequency of the compressor in the previous operating cycle of the current operating cycle; △u(k) represents the target frequency adjustment parameter. In other words, the heat pump unit can determine the target output frequency of the current operating cycle based on the historical output frequency of the previous operating cycle and the target frequency adjustment parameter. Among them, the target frequency adjustment parameter △u(k) can be determined based on the target temperature difference, the target temperature difference change rate and the pre-stored capacity calculation mapping relationship table.

[0070] In some embodiments, in the process of determining the target rate adjustment parameters based on the target temperature difference, the target temperature difference change rate, and a pre-stored capacity calculation mapping table, the heat pump unit can obtain the air conditioning side water outlet temperature and the heating target temperature of the heat pump unit in the current operating cycle. As shown in FIG1 , the air conditioning side water outlet temperature can be detected by a fourth temperature sensor. The heating target temperature can be a pre-set heating demand temperature, which can be customized. The heat pump unit can then determine the target temperature difference for the current operating cycle based on the air conditioning side water outlet temperature and the heating target temperature, and obtain the historical temperature difference of the heat pump unit in the previous operating cycle of the current operating cycle. Based on the target temperature difference and the historical temperature difference, the target temperature difference change rate is determined. Since the pre-stored capacity calculation mapping table includes a plurality of preset temperature difference ranges, a plurality of temperature difference change rate ranges, and a correspondence between the temperature difference range, the temperature difference change rate range, and the frequency adjustment parameter, the heat pump unit can match the target frequency adjustment parameter from the capacity calculation mapping table based on the target temperature difference and the target temperature difference change rate.

[0071] In some embodiments, the heat pump unit can substitute the AC outlet water temperature and the heating target temperature during the current operating cycle into the following formula: Temperature Difference = (Heating Target Temperature - Preset Parameter) - AC Outlet Water Temperature to determine the target temperature difference for the current operating cycle. The preset parameter can be customized, for example, 1°C.

[0072] In some embodiments, the heat pump unit may use the difference between the historical temperature difference and the target temperature difference as the target temperature difference change rate.

[0073] In some embodiments, the heat pump unit matches the target frequency adjustment parameters from the capacity calculation mapping table based on the target temperature difference and the target temperature difference change rate, including: determining the target temperature difference range corresponding to the target temperature difference, and determining the target change rate range corresponding to the target temperature difference change rate; matching the target frequency adjustment parameters corresponding to the target temperature difference range and the target change rate range from the capacity calculation mapping table.

[0074] In some embodiments, when matching a target frequency adjustment parameter from a capacity calculation mapping table based on a target temperature difference and a target temperature difference change rate, the heat pump unit may match a target temperature difference range corresponding to the target temperature difference from multiple sets of temperature difference ranges in the capacity calculation mapping table, and match a target temperature difference change rate range corresponding to the target temperature difference change rate from multiple sets of temperature difference change rate ranges. The heat pump unit may then determine the target frequency adjustment parameter corresponding to the target temperature difference and the target temperature difference change rate based on the corresponding relationship between the temperature difference ranges, the temperature difference change rate ranges, and the frequency adjustment parameter in the capacity calculation mapping table.

[0075] As an example, please refer to Table 1 below, which shows a capacity calculation mapping table provided in an embodiment of the present application when the target operating mode is a heating mode or a heating plus domestic hot water mode. As shown in Table 1 below, the capacity calculation mapping table includes preset multiple groups of temperature difference ranges, multiple groups of temperature difference change rate ranges, and the correspondence between the temperature difference ranges, the temperature difference change rate ranges, and the frequency adjustment parameters. Among them, the multiple groups of temperature difference ranges, the multiple groups of temperature difference change rate ranges, and the corresponding frequency adjustment parameters in the pre-stored capacity calculation mapping table can be customized. The settings in Table 1 are for example explanation. This application does not limit the specific values ​​of the multiple groups of temperature difference ranges, the multiple groups of temperature difference change rate ranges, and the corresponding frequency adjustment parameters.

[0076] As an example, if the target temperature difference is determined to be 1 and the target temperature difference change rate is 0.3, according to Table 1, the target temperature difference range corresponding to the target temperature difference is (0.3, 1.5], and the target change rate range corresponding to the target temperature difference change rate is (0.2, 0.4]). According to the correspondence between the temperature difference range, the temperature difference change rate range, and the frequency adjustment parameter in Table 1, the target frequency adjustment parameter can be determined to be a34. Therefore, it can be seen that the target output frequency of the compressor in the current operating cycle is equal to the output frequency of the compressor in the previous operating cycle plus a34.

[0077] Table 1

[0078] In some embodiments, the output frequency of the compressor in a heat pump unit affects the unit's heating or domestic hot water production performance. By adjusting the compressor output frequency, the heat pump unit can operate more efficiently under varying conditions and effectively maintain a stable temperature (e.g., heating temperature).

[0079] In some embodiments of the present application, the control method also includes: switching the target operating mode according to the second demand judgment strategy, the target operating mode including any one of heating mode, heating plus domestic hot water mode, domestic hot water mode, standby mode, alarm shutdown mode and electric heating mode.

[0080] In some embodiments, after the heat pump unit controls the compressor to operate in the target operating mode according to the target output frequency, the heat pump unit can monitor parameters such as hot water temperature, hot water inlet temperature, and exhaust temperature in real time. When parameters such as hot water temperature, hot water inlet temperature, and exhaust temperature meet the preset conditions, the heat pump unit can control the switching of the target operating mode to ensure efficient operation of the heat pump unit and avoid unnecessary energy waste.

[0081] In some embodiments, the target operating mode includes but is not limited to any one of a heating mode, a heating plus domestic hot water mode, a domestic hot water mode, a standby mode, an alarm shutdown mode, and an electric heating mode.

[0082] In some embodiments of the present application, the target operating mode is switched according to the second demand judgment strategy, including: switching the target operating mode of the heat pump unit if any of the following conditions is met: the hot water inlet temperature of the heat pump unit is greater than the first temperature threshold; the heat pump unit does not have a second heating demand; within a preset time period, the difference between the exhaust temperature and the hot water inlet temperature is less than the second temperature threshold.

[0083] In some embodiments, the first temperature threshold, the second temperature threshold and the preset time can all be customized. For example, the first temperature threshold can be set to 68°C, the second temperature threshold can be set to 5°C, and the preset time can be set to 10 minutes.

[0084] In some embodiments, the absence of a second heating demand for the heat pump unit means that the heating function provided by the heat pump unit can meet the user's demand for heating. At this time, the heat pump unit can adjust the target operating mode to the domestic hot water mode, or control the heat pump unit to enter the standby mode. It is necessary to further determine whether the domestic hot water prepared by the heat pump unit meets the user's demand for domestic hot water.

[0085] In some embodiments, the conditions for triggering the heat pump unit to switch to the target operating mode include but are not limited to the hot water inlet temperature of the heat pump unit being greater than a first temperature threshold; or the heat pump does not have a second heating demand; or within a preset time period, the difference between the exhaust temperature and the hot water inlet temperature is less than a second temperature threshold.

[0086] In some embodiments of the present application, the heat pump unit can determine whether there is a second heating demand in the following manner: obtain the air-conditioning side water outlet temperature of the heat pump unit; if the air-conditioning side water outlet temperature is greater than the sum of the heating target temperature and the shutdown temperature difference within the second time period, determine that the heat pump unit does not have a second heating demand; if the air-conditioning side water outlet temperature is less than or equal to the sum of the heating target temperature and the shutdown temperature difference within the second time period, determine that the heat pump unit has a second heating demand.

[0087] In some embodiments, the second time period can be customized, for example, the second time period can be set to 5 seconds. The heating target temperature can be customized by the user according to needs.

[0088] In some embodiments, when the outlet water temperature on the air conditioner side is greater than the sum of the heating target temperature and the shutdown temperature difference during the second time period, it indicates that the heating temperature provided by the heat pump unit can meet the user's demand, that is, it is determined that the heat pump unit does not have a second heating demand. At this time, the heat pump unit can be controlled to enter a standby mode or switch to another operating mode. When the outlet water temperature on the air conditioner side is less than or equal to the sum of the heating target temperature and the shutdown temperature difference during the second time period, it indicates that the heating temperature provided by the heat pump unit cannot yet meet the user's demand, that is, it is determined that the heat pump unit has a second heating demand.

[0089] In some embodiments of the present application, the target operating mode is switched according to the second demand judgment strategy, including but not limited to the following situations: when the heat pump unit is operating in the heating plus domestic hot water mode, if the hot water temperature is less than the third temperature threshold, the target operating mode is switched to the domestic hot water mode; when the heat pump unit is operating in the domestic hot water mode, if the hot water temperature is greater than or equal to the fourth temperature threshold, and the heat pump has a second heating demand, the target operating mode is switched to the heating plus domestic hot water mode; if the hot water temperature is less than the fifth temperature threshold, the target operating mode is switched to the electric heating mode.

[0090] It should be noted that the electric heating mode mainly refers to the electric auxiliary heater installed in the domestic hot water tank 10 to help speed up the production of domestic hot water. The electric auxiliary heater can be a PTC electric heating rod or a nanotube heating rod. The domestic hot water heat exchanger plus the electric auxiliary heater can quickly replenish the thermal energy in the domestic hot water tank 10 to achieve a continuous supply of hot water.

[0091] In some embodiments, the third temperature threshold, the fourth temperature threshold, and the fifth temperature threshold can be customized. For example, the third temperature threshold can be set to 51°C, the fourth temperature threshold can be set to 60°C, and the fifth temperature threshold can be set to 45°C.

[0092] In some embodiments, when the target operating mode is the heating plus domestic hot water mode, if the heat pump unit's hot water temperature is detected to be less than a third temperature threshold, the heat pump unit prioritizes meeting the domestic hot water demand and switches the target operating mode from the heating plus domestic hot water mode to the domestic hot water mode to improve the efficiency of preparing domestic hot water. When the target operating mode is the domestic hot water mode, if the heat pump unit's hot water temperature is detected to be greater than or equal to a fourth temperature threshold, indicating that the domestic hot water temperature prepared by the heat pump unit can meet the user's domestic hot water temperature demand, continuing to operate in the domestic hot water mode will result in low operating efficiency of the heat pump unit. If the heat pump unit's hot water temperature is greater than or equal to the fourth temperature threshold and the heat pump unit has a second heating demand, the heat pump unit may switch the target operating mode from the domestic hot water mode to the heating plus domestic hot water mode to improve the heat pump unit's operating efficiency.

[0093] In some embodiments, if the hot water temperature of the heat pump unit is detected to be less than a fifth temperature threshold, indicating that the hot water temperature is too low, the heat pump unit may switch its target operating mode to electric heating mode to assist in heating the water in the hot water tank in order to meet the user's domestic hot water demand as quickly as possible. The fifth temperature threshold can be customized, for example, the fifth temperature threshold can be set to 45°C.

[0094] As an example, please refer to Figure 3, which shows an example diagram of the control principle of the control method of the heat pump unit provided by the embodiment of the present application. As shown in Figure 3, in winter, the hot water temperature reaches 60℃.

[0095] If there is a demand for heating, the heat pump unit can operate in heating + domestic hot water mode. At this time, the heat pump unit prioritizes heating, and the hot water temperature can be raised to 70°C. When the hot water temperature is below 51°C, domestic hot water preparation is prioritized, and the heat pump unit can be controlled to switch from heating + domestic hot water mode to domestic hot water mode. Until the hot water temperature reaches 60°C, if there is a demand for heating, the heat pump unit can switch from domestic hot water mode to heating + domestic hot water mode. When the hot water temperature is below 45°C, the heat pump unit prioritizes domestic hot water preparation, meeting the domestic hot water demand. At this time, the heat pump unit can switch the target operating mode to electric heating mode, starting electric heating until the hot water temperature rises to 70°C, at which point the electric heating mode can be controlled to shut down.

[0096] In some embodiments of the present application, the heat pump unit includes a first valve and a second valve, and the control method further includes: if the target operating mode is a domestic hot water mode, setting both the first valve and the second valve to open valves; if the target operating mode is a heating mode, setting the first valve to closed valves and setting the second valve to open valves; if the target operating mode is a heating plus domestic water mode, setting the first valve to open valves and setting the second valve to closed valves.

[0097] In some embodiments, the first valve may be the first three-way valve as shown in FIG1 , and the second valve may be the second three-way valve as shown in FIG1 . Opening the first valve may mean that the second and third interfaces of the first three-way valve are open, while the first interface is closed; closing the first valve may mean that the first and third interfaces of the first three-way valve are open, while the second interface is closed. Opening the second valve may mean that the second and third interfaces of the second three-way valve are open, while the first interface is closed; closing the second valve may mean that the first and third interfaces of the second three-way valve are open, while the second interface is closed.

[0098] In some embodiments, when the target operating mode is the domestic hot water mode, the first valve and the second valve are both controlled to open. Taking the device connection diagram of the heat pump unit shown in Figure 1 as an example, when the target operating mode is the domestic hot water mode, the high-temperature and high-pressure gaseous refrigerant discharged by the compressor flows into the domestic hot water heat exchanger through the second interface and the third interface of the first valve (first three-way valve), and the domestic hot water heat exchanger is connected to the domestic hot water tank. The high-temperature and high-pressure gaseous refrigerant flowing into the domestic hot water heat exchanger exchanges heat with the domestic hot water tank to prepare domestic hot water. The liquid refrigerant after heat exchange with the domestic hot water tank flows out of the domestic hot water heat exchanger, passes through the second interface and the third interface of the second valve (second three-way valve) in sequence, flows into the liquid storage tank, and then flows into the enthalpy increase module. The liquid refrigerant passes through the enthalpy increase module to form a low-temperature liquid refrigerant, which flows into the evaporator. The low-temperature liquid refrigerant absorbs heat in the evaporator. The evaporator absorbs external heat and evaporates the low-temperature liquid refrigerant into a low-temperature gaseous refrigerant. The low-temperature gaseous refrigerant is sucked into the compressor through the four-way valve. The compressor compresses the low-temperature gaseous refrigerant into a high-temperature and high-pressure gaseous refrigerant, thereby completing the cycle of preparing domestic hot water.

[0099] In some embodiments, when the target operating mode is heating mode, the first valve is controlled to close and the second valve is controlled to open. Taking the component connection diagram of the heat pump unit shown in Figure 1 as an example, when the target operating mode is heating mode, the high-temperature, high-pressure gaseous refrigerant discharged from the compressor flows through the first and third interfaces of the first valve to the four-way valve, and then flows through the four-way valve into the air conditioner-side heat exchanger. When condensed in the air conditioner-side heat exchanger, the high-temperature, high-pressure gaseous refrigerant releases heat, heating the water in the air conditioner water tank connected to the air conditioner-side heat exchanger, thereby raising the temperature of the water in the air conditioner water tank and achieving heating. The high-temperature, high-pressure gaseous refrigerant condenses to form liquid refrigerant, which is throttled by the enthalpy increase module to form low-temperature liquid refrigerant. The low-temperature liquid refrigerant flows to the evaporator. The evaporator absorbs external heat and evaporates the low-temperature liquid refrigerant into low-temperature gaseous refrigerant. The evaporated low-temperature gaseous refrigerant passes through the four-way valve and is drawn into the compressor, completing the heating cycle.

[0100] In some embodiments, when the target operating mode is heating plus domestic hot water mode, the first valve is controlled to open and the second valve is controlled to close. An example diagram of refrigerant operation when the target operating mode is heating plus domestic hot water mode is shown in FIG1 and will not be further described here.

[0101] In a control method for a heat pump unit provided in an embodiment of the present application, when the standby operating mode of the heat pump unit is set to the heating plus domestic hot water mode, the target operating mode of the heat pump unit is determined according to a first demand judgment strategy, wherein the target operating mode includes any one of the heating mode, the heating plus domestic hot water mode, and the domestic hot water mode. The heat pump unit then calculates the target output frequency under the target operating mode based on a pre-stored capacity calculation mapping table, and controls the compressor to operate according to the target output frequency. The present application avoids directly controlling the heat pump unit to operate in the heating plus domestic hot water mode at a high frequency, which results in excessive energy consumption during operation, thereby improving the operating efficiency of the heat pump unit.

[0102] It should be understood that the size of the serial numbers of the steps in the above embodiments does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0103] In one embodiment of the present application, a control device 400 for a heat pump unit is provided, wherein the heat pump unit includes a compressor, and the functions that can be implemented by the control device 400 of the heat pump unit correspond one-to-one to the control method of the heat pump unit in the above embodiment. As shown in Figure 4, the control device 400 of the heat pump unit includes a setting module 401, a determination module 402 and a control module 403. The detailed description of each functional module is as follows: the setting module 401 is used to set the standby operating mode of the heat pump unit to the heating plus domestic hot water mode; the determination module 402 is used to determine the target operating mode of the heat pump unit according to the first demand judgment strategy, and the target operating mode includes any one of the heating mode, the heating plus domestic hot water mode and the domestic hot water mode; the control module 403 is used to calculate the target output frequency under the target operating mode based on the pre-stored capacity calculation mapping table, and control the compressor to operate according to the target output frequency.

[0104] The specific definitions of the heat pump unit control device 400 can be found in the definitions of the heat pump unit control method described above and will not be repeated here. Each module in the heat pump unit control device 400 can be implemented in whole or in part through software, hardware, or a combination thereof. Each of the modules can be embedded in or independent of a processor in the heat pump unit in hardware form, or stored in a memory in the heat pump unit in software form, so that the processor can call and execute the corresponding operations of each module.

[0105] FIG5 is a schematic diagram of the structure of a heat pump unit according to an embodiment of the present application. The heat pump unit 100 can be used in applications such as air conditioning and heating systems. The network in which the heat pump unit 100 resides includes, but is not limited to, the Internet, a wide area network (WAN), a metropolitan area network (MAN), a local area network (LAN), a virtual private network (VPN), and the like.

[0106] As shown in Figure 5, the heat pump unit 100 includes a communication module 101, a memory 102, a processor 103, an input / output (I / O) interface 104, and a bus 105. The processor 103 is coupled to the communication module 101, the memory 102, and the I / O interface 104 via the bus 105.

[0107] The communication module 101 can be a wireless communication module or a mobile communication module. The wireless communication module can provide wireless communication solutions for the heat pump unit 100, including wireless local area networks (WLAN) (e.g., wireless fidelity (Wi-Fi) networks), Bluetooth (BT), global navigation satellite system (GNSS), frequency modulation (FM), near field communication (NFC), infrared technology (IR), etc. The mobile communication module can provide wireless communication solutions for the heat pump unit 100, including 2G / 3G / 4G / 5G.

[0108] The memory 102 may include one or more random access memories (RAMs) and one or more non-volatile memories (NVMs). The RAM can be directly read and written by the processor 103 and can be used to store executable programs (e.g., machine instructions) of the operating system or other running programs, as well as user and application data. The RAM may include static random-access memory (SRAM), dynamic random-access memory (DRAM), synchronous dynamic random-access memory (SDRAM), double data rate synchronous dynamic random-access memory (DDR SDRAM, for example, the fifth generation of DDR SDRAM is generally referred to as DDR5 SDRAM), etc.

[0109] The non-volatile memory can also store executable programs and user and application data, etc., which can be pre-loaded into the random access memory for direct reading and writing by the processor 103. The non-volatile memory can include disk storage devices and flash memory.

[0110] The memory 102 is used to store one or more computer programs. The one or more computer programs are configured to be executed by the processor 103. The one or more computer programs include multiple instructions. When the multiple instructions are executed by the processor 103, the heat pump unit control method executed on the heat pump unit 100 can be implemented.

[0111] In other embodiments, the heat pump unit 100 further includes an external memory interface for connecting to an external memory to expand the storage capacity of the heat pump unit 100 .

[0112] The processor 103 may include one or more processing units. For example, the processor 103 may include an application processor (AP), a modem processor, a graphics processing unit (GPU), an image signal processor (ISP), a controller, a video codec, a digital signal processor (DSP), a baseband processor, and / or a neural-network processing unit (NPU). The different processing units may be independent devices or integrated into one or more processors.

[0113] The processor 103 provides computing and control capabilities. For example, the processor 103 is used to execute a computer program stored in the memory 102 to implement the above-mentioned control method of the heat pump unit.

[0114] The I / O interface 104 is used to provide a channel for user input or output. For example, the I / O interface 104 can be used to connect various input and output devices, such as a mouse, keyboard, touch device, display screen, etc., so that the user can enter information or visualize information.

[0115] The bus 105 is at least used to provide a channel for mutual communication among the communication module 101 , the memory 102 , the processor 103 , and the I / O interface 104 in the heat pump unit 100 .

[0116] It should be understood that the structure illustrated in the embodiments of the present application does not constitute a specific limitation on the heat pump unit 100. In other embodiments of the present application, the heat pump unit 100 may include more or fewer components than illustrated, or may combine or separate certain components, or have different component arrangements. The illustrated components may be implemented in hardware, software, or a combination of software and hardware.

[0117] An embodiment of the present application further provides a computer-readable storage medium, on which a computer program is stored. The computer program includes program instructions. The method implemented when the program instructions are executed can refer to the control method of the heat pump unit in the above-mentioned embodiments of the present application.

[0118] The computer-readable storage medium may be the internal memory of the heat pump unit described in the above embodiment, such as the hard disk or memory of the heat pump unit. The computer-readable storage medium may also be an external storage device of the heat pump unit, such as a plug-in hard disk, a smart media card (SMC), a secure digital (SD) card, a flash card, etc. equipped on the heat pump unit.

[0119] Furthermore, the computer-readable storage medium may mainly include a program storage area and a data storage area, wherein the program storage area may store an operating system, an application required for at least one function, etc.; the data storage area may store data created according to the use of the heat pump unit, etc.

[0120] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application and are not intended to limit the present application. Although the present application has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present application may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present application.

Claims

1. A control method for a heat pump unit, the heat pump unit comprising a compressor, characterized in that: The control method comprises: Setting the standby operation mode of the heat pump unit to a heating plus domestic hot water mode; Determining a target operation mode of the heat pump unit according to a first demand judgment strategy, wherein the target operation mode includes any one of a heating mode, a heating plus domestic hot water mode, and a domestic hot water mode; The target output frequency in the target operation mode is calculated based on a pre-stored capacity calculation mapping table, and the compressor is controlled to operate according to the target output frequency.

2. The control method according to claim 1, characterized in that: Determining the target operation mode of the heat pump unit according to the first demand judgment strategy includes: If the heat pump unit has a first heating demand, and the hot water temperature, hot water inlet temperature and exhaust temperature of the heat pump unit all meet the first condition, determining that the target operation mode is a heating plus domestic hot water mode; If the heat pump unit has the first heating demand, and the hot water temperature and the hot water inlet temperature both meet the second condition, the target operation mode is determined to be the domestic hot water mode.

3. The control method according to claim 2, characterized in that: Determining the target operation mode of the heat pump unit according to the first demand judgment strategy includes: If the heat pump unit does not have the first heating demand, and the hot water temperature and the hot water inlet temperature both meet the third condition, the target operation mode is determined to be the domestic hot water mode.

4. The control method according to claim 3, characterized in that: The control method further comprises: Obtaining the outlet water temperature of the air-conditioning side of the heat pump unit; If the outlet water temperature of the air conditioner side is greater than the difference between the heating target temperature and the startup temperature difference within the first time period, it is determined that the heat pump unit does not have the first heating demand; If the air-conditioning side water outlet temperature is less than or equal to the difference between the heating target temperature and the startup temperature difference within the first time period, it is determined that the heat pump unit has the first heating demand.

5. The control method according to claim 1, characterized in that: The calculating the target output frequency in the target operating mode based on a pre-stored capacity calculation mapping table includes: If it is determined that the target operation mode is the heating mode or the heating plus domestic hot water mode, the air-conditioning side water outlet temperature and the heating target temperature of the heat pump unit in the current operation cycle are obtained; Determining a target temperature difference based on the air conditioning side water outlet temperature and the heating target temperature; Determine a target temperature difference change rate based on the target temperature difference and the historical temperature difference, wherein the historical temperature difference is the temperature difference of the previous operation cycle of the current operation cycle; matching a target frequency adjustment parameter from the capability calculation mapping table based on the target temperature difference and the target temperature difference change rate; The target output frequency of the compressor in the current operation cycle is calculated based on the target frequency adjustment parameter and the historical output frequency of the compressor in the previous operation cycle.

6. The control method according to claim 3, characterized in that: The control method further comprises: The target operation mode is switched according to the second demand judgment strategy, and the target operation mode includes any one of a heating mode, a heating plus domestic hot water mode, a domestic hot water mode, a standby mode, an alarm shutdown mode and an electric heating mode.

7. The control method according to claim 6, characterized in that: The switching of the target operation mode according to the second demand determination strategy includes: If any of the following conditions is met, the target operation mode of the heat pump unit is switched: The hot water inlet temperature of the heat pump unit is greater than a first temperature threshold; The heat pump unit does not have a second heating demand; Within a preset time period, the difference between the exhaust temperature and the hot water inlet temperature is less than a second temperature threshold.

8. The control method according to claim 7, characterized in that: The control method further comprises: Obtaining the outlet water temperature of the air-conditioning side of the heat pump unit; If the outlet water temperature of the air conditioner side is greater than the sum of the heating target temperature and the shutdown temperature difference within the second time period, it is determined that the heat pump unit does not have the second heating demand; If the air-conditioning side outlet water temperature is less than or equal to the sum of the heating target temperature and the shutdown temperature difference within the second time period, it is determined that the heat pump unit has the second heating demand.

9. The control method according to claim 7, characterized in that: The switching of the target operation mode according to the second demand determination strategy includes: When the heat pump unit operates in the heating plus domestic hot water mode, if the hot water temperature is lower than a third temperature threshold, switching the target operation mode to the domestic hot water mode; When the heat pump unit operates in the domestic hot water mode, if the hot water temperature is greater than or equal to a fourth temperature threshold and the heat pump has the second heating demand, switching the target operation mode to the heating plus domestic hot water mode; If the hot water temperature is less than a fifth temperature threshold, the target operation mode is switched to an electric heating mode.

10. The control method according to claim 1, characterized in that: The heat pump unit includes a first valve and a second valve, and the control method further includes: If the target operation mode is the domestic hot water mode, both the first valve and the second valve are set to open; If the target operation mode is a heating mode, the first valve is set to be closed and the second valve is set to be open; If the target operation mode is heating plus domestic water use mode, the first valve is set to open And set the second valve to a closed position.

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