Heat pump system control method, heat pump system, hot and cold water unit and storage medium

Abstract

The present invention discloses a control method for a heat pump system, a heat pump system, a hot and cold water unit, and a storage medium. The method comprises: obtaining a first difference between the outlet and inlet water temperatures of the heat pump system, and a second difference between the outlet and target water temperatures; determining a target frequency based on the first and second differences and the rated capacity of the heat pump system; and controlling the compressor of the heat pump system to operate according to the target frequency. This technical solution can match the compressor operating frequency to the actual load, avoid frequent compressor starts and stops, and reduce water temperature fluctuations on the user side.

Description

Technical Field

[0001] The present invention relates to the technical field of heat pump systems, and in particular to a control method for a heat pump system, a heat pump system, a hot and cold water unit, and a storage medium. Background Art

[0002] A heat pump system is a hot water supply system that uses air, groundwater, or surface water as a low-temperature heat source and water as a heat transfer medium, employing vapor compression heat pump technology to heat domestic hot water. Currently, after a heat pump system is turned on, the compressor typically operates at maximum frequency. However, if the compressor operating frequency does not match actual energy demand, this can lead to frequent compressor starts and stops, resulting in significant fluctuations in water temperature on the user side. Summary of the Invention

[0003] The embodiments of the present application aim to solve the problem of large fluctuations in water temperature on the user side caused by frequent starting and stopping of the compressor by providing a control method for a heat pump system, a heat pump system, a hot and cold water unit, and a storage medium.

[0004] An embodiment of the present application provides a control method for a heat pump system, which is applied to a heat pump system. The control method for the heat pump system includes:

[0005] Obtaining a first difference between an outlet water temperature and an inlet water temperature of the heat pump system, and a second difference between the outlet water temperature and a target water temperature;

[0006] determining a target frequency according to the first difference, the second difference, and a rated capacity of the heat pump system;

[0007] The compressor of the heat pump system is controlled to operate according to the target frequency.

[0008] Optionally, the step of determining the target frequency according to the first difference, the second difference and the rated capacity of the heat pump system includes:

[0009] determining a correction coefficient according to the first difference and the second difference;

[0010] The target frequency is determined according to the correction factor and the rated capacity of the heat pump system.

[0011] Optionally, the correction coefficient includes a first correction coefficient and a second correction coefficient, and the step of determining the correction coefficient according to the first difference and the second difference includes:

[0012] determining a first temperature interval within which the first difference value lies;

[0013] determining a first correction coefficient according to a first preset value associated with the first temperature range;

[0014] determining a second temperature interval within which the second difference lies;

[0015] A second correction coefficient is determined according to a second preset value associated with the second temperature range.

[0016] Optionally, the heat pump system further includes a water-side heat exchanger, and the step of determining the target frequency according to the correction coefficient and the rated capacity of the heat pump system includes:

[0017] determining the energy demand corresponding to the water-side heat exchanger according to the first correction coefficient, the second correction coefficient, and the rated capacity of the heat pump system;

[0018] The target frequency is determined according to the energy demand corresponding to the water-side heat exchanger.

[0019] Optionally, the step of determining the target frequency according to the energy demand corresponding to the water-side heat exchanger includes:

[0020] When the heat pump system has a water-side heat exchanger, the target frequency is determined according to the energy demand corresponding to the water-side heat exchanger;

[0021] When the heat pump system has at least two water-side heat exchangers, the total energy demand is determined according to the energy demand corresponding to each of the water-side heat exchangers, and the target frequency is determined according to the total energy demand.

[0022] Optionally, determining the target frequency according to the correction coefficient and the rated capacity of the heat pump system includes:

[0023] Get the current ambient temperature;

[0024] The target frequency is determined according to the current ambient temperature, the first correction factor, the second correction factor, and the rated capacity of the heat pump system.

[0025] Optionally, the step of determining the target frequency according to the current ambient temperature, the first correction coefficient, the second correction coefficient, and the rated capacity of the heat pump system includes:

[0026] Determine a third temperature interval in which the current ambient temperature falls;

[0027] determining a third correction coefficient and a fourth correction coefficient according to the third temperature range;

[0028] The target frequency is determined according to the current ambient temperature, the first correction factor, the second correction factor, the third correction factor, the fourth correction factor, and the rated capacity of the heat pump system.

[0029] Optionally, after determining the target frequency according to the first difference, the second difference, and the rated capacity of the heat pump system, the method further includes:

[0030] Get the current operating frequency of the compressor;

[0031] Determine the frequency interval in which the current operating frequency is located;

[0032] determining a preset frequency adjustment period associated with the frequency interval;

[0033] The step of controlling the compressor of the heat pump system to operate according to the target frequency includes:

[0034] The current operating frequency of the compressor is adjusted to the target frequency based on the preset frequency adjustment period.

[0035] Optionally, controlling the compressor of the heat pump system to operate according to the target frequency includes:

[0036] When the target frequency is greater than a first preset operating frequency, controlling the compressor to operate at the first preset operating frequency;

[0037] When the target frequency is less than a second preset operating frequency, controlling the compressor to operate at the second preset operating frequency, wherein the first preset operating frequency is greater than the second preset operating frequency;

[0038] When the target frequency is between the first preset operating frequency and the second preset operating frequency, the compressor is controlled to operate at the target frequency.

[0039] In addition, to achieve the above object, the present invention also provides a heat pump system, which includes:

[0040] compressor;

[0041] The water-side heat exchanger is disposed between the four-way valve and the throttling component and is configured as a component for exchanging heat between water and refrigerant;

[0042] a four-way valve, disposed on a refrigerant circuit and configured to adjust a refrigerant flow direction of the refrigerant circuit;

[0043] a throttling component connected to an output end of the water-side heat exchanger;

[0044] a heat source side heat exchanger, disposed between the four-way valve and the throttling component, configured as a component for exchanging heat between the refrigerant and the heat source side medium;

[0045] A control device, comprising: a memory, a processor, and a control program for a heat pump system stored in the memory and executable on the processor, wherein the control program for the heat pump system, when executed by the processor, implements the steps of the above-mentioned control method for the heat pump system.

[0046] In addition, to achieve the above-mentioned purpose, the present invention also provides a hot and cold water unit, which comprises: a heat pump system; and

[0047] A water circulation system, the water circulation system includes the water-side heat exchanger, a water pump and a utilization-side heat exchanger, the utilization-side heat exchanger is used to exchange heat with the air in the action space, and the water pump is used to drive water to circulate between the water-side heat exchanger, the water pump and the utilization-side heat exchanger.

[0048] In addition, to achieve the above objectives, the present invention also provides a computer-readable storage medium on which a control program of a heat pump system is stored. When the control program of the heat pump system is executed by a processor, the steps of the above-mentioned control method of the heat pump system are implemented.

[0049] A technical solution for a heat pump system control method, a heat pump system, a hot and cold water unit, and a storage medium provided in an embodiment of the present application adopts a technical solution of obtaining a first difference between the outlet water temperature and the inlet water temperature of the heat pump system, and a second difference between the outlet water temperature and the target water temperature; determining a target frequency based on the first difference, the second difference, and the rated capacity of the heat pump system, and controlling the compressor of the heat pump system to operate according to the target frequency. This method calculates the target frequency of the compressor based on the inlet and outlet water temperature difference, the difference between the outlet water temperature and the target water temperature, and the rated capacity of the system, so that the target frequency of the compressor operation matches the actual load, avoids frequent starting and stopping of the compressor, and thereby reduces water temperature fluctuations on the user side. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Figure 1 This is a schematic structural diagram of a heat pump system involved in an embodiment of the present invention;

[0051] Figure 2 This is a schematic diagram of the structure of a control device involved in an embodiment of the present invention;

[0052] Figure 3 This is a flow chart of a first embodiment of a control method for a heat pump system according to the present invention;

[0053] Figure 4 1 is a flow chart of an embodiment of a control method for a heat pump system according to the present invention.

[0054] The realization of the purpose, functional features and advantages of this application will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. The above-mentioned drawings are only an embodiment diagram, not the entire invention. DETAILED DESCRIPTION

[0055] In order to solve the problem of large water temperature fluctuations on the user side caused by frequent starting and stopping of the compressor, the present application proposes a control method for a heat pump system. The method calculates the target frequency of the compressor based on the inlet and outlet water temperature difference, the difference between the outlet water temperature and the target water temperature, and the rated capacity of the system, so that the target frequency of the compressor operation is matched with the actual load, avoiding frequent starting and stopping of the compressor, and thereby reducing the water temperature fluctuations on the user side.

[0056] To better understand the above technical solutions, exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments described herein. Instead, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art.

[0057] like Figure 1 As shown, Figure 1 Schematic diagram of the structure of the heat pump system involved in the embodiment of the present invention.

[0058] It should be noted that Figure 1 This is a structural diagram of the hardware operating environment of the heat pump system.

[0059] like Figure 1 As shown, the heat pump system may include: a compressor 1;

[0060] A water-side heat exchanger 2, which is disposed between the four-way valve and the throttling component and is configured as a component for exchanging heat between water and refrigerant;

[0061] A four-way valve 3 is provided on the refrigerant circuit and is configured to adjust the refrigerant flow direction of the refrigerant circuit;

[0062] A throttling component 4, wherein the throttling component is connected to the output end of the water-side heat exchanger;

[0063] The heat source side heat exchanger 5 is provided between the four-way valve and the throttle component, and is configured as a component for exchanging heat between the refrigerant and the heat source side medium.

[0064] Optionally, the above-mentioned compressor has an exhaust port and a return air port; the above-mentioned four-way valve has an E valve port, a D valve port, a C valve port and an S valve port, the E valve port is connected to one of the D valve port and the S valve port, and the C valve port is connected to the other of the D valve port and the S valve port, wherein the S valve port is connected to the return air port, and the D valve port is connected to the exhaust port; the above-mentioned water-side heat exchanger is an indoor heat exchanger, and the heat source side heat exchanger is an outdoor heat exchanger, one end of the heat source side heat exchanger is connected to the E valve port, and one end of the water side heat exchanger is connected to the C valve port, and a throttling component is connected in series between the other end (output end) of the water side heat exchanger and the other end of the heat source side heat exchanger.

[0065] Optionally, temperature sensors may be provided at the water inlet and outlet of the water-side heat exchanger, respectively, to collect the inlet and outlet water temperatures. Optionally, a first temperature sensor provided at the water outlet of the water-side heat exchanger may be used to collect the outlet water temperature, while a second temperature sensor provided at the water inlet of the water-side heat exchanger may be used to collect the inlet water temperature. Optionally, both the first and second temperature sensors are connected to a control device, and the temperatures collected by the first and second temperature sensors may be transmitted to the control device for processing to further determine the target frequency of the heat pump system's compressor.

[0066] Optionally, Figure 1 The solid line in the figure represents the refrigerant flow direction in the heating mode, and the dotted line represents the refrigerant flow direction in the cooling mode. This application uses the method of determining the compressor operating frequency in the cooling mode as an example. The method of determining the compressor operating frequency in the heating mode is similar to that used in the cooling mode, so it will not be repeated here.

[0067] Optionally, the heat pump system further comprises a control device, referring to Figure 2 , the control device includes: a processor 1001, such as a CPU, a memory 1005, a user interface 1003, a network interface 1004, and a communication bus 1002. Among them, the communication bus 1002 is used to realize the connection and communication between these components. The user interface 1003 may include a display screen (Display), an input unit such as a keyboard (Keyboard), and the user interface 1003 may optionally include a standard wired interface and a wireless interface. The network interface 1004 may optionally include a standard wired interface and a wireless interface (such as a WI-FI interface). The memory 1005 may be a high-speed RAM memory, or a stable memory (non-volatile memory), such as a disk memory. The memory 1005 may optionally be a storage device independent of the aforementioned processor 1001.

[0068] Those skilled in the art will understand that Figure 2The structure of the control device shown in the figure does not constitute a limitation on the control device, and the control device may include more or fewer components than shown in the figure, or combine certain components, or arrange the components differently.

[0069] like Figure 2 As shown, the memory 1005 as a storage medium may include an operating system, a network communication module, a user interface module, and a control program for the heat pump system. The operating system is a program that manages and controls the hardware and software resources of the heat pump system, and the control program of the heat pump system and other software or programs are executed.

[0070] exist Figure 2 In the control device shown, the user interface 1003 is mainly used to connect to the terminal and communicate data with the terminal; the network interface 1004 is mainly used to communicate data with the background server; the processor 1001 can be used to call the control program of the heat pump system stored in the memory 1005.

[0071] In this embodiment, the control device includes: a memory 1005, a processor 1001, and a control program of the heat pump system stored in the memory and executable on the processor, wherein:

[0072] When the processor 1001 calls the control program of the heat pump system stored in the memory 1005, it performs the following operations:

[0073] Obtaining a first difference between an outlet water temperature and an inlet water temperature of the heat pump system, and a second difference between the outlet water temperature and a target water temperature;

[0074] determining a target frequency according to the first difference, the second difference, and a rated capacity of the heat pump system;

[0075] The compressor of the heat pump system is controlled to operate according to the target frequency.

[0076] When the processor 1001 calls the control program of the heat pump system stored in the memory 1005, it also performs the following operations:

[0077] determining a correction coefficient according to the first difference and the second difference;

[0078] The target frequency is determined according to the correction factor and the rated capacity of the heat pump system.

[0079] When the processor 1001 calls the control program of the heat pump system stored in the memory 1005, it also performs the following operations:

[0080] determining a first temperature interval within which the first difference value lies;

[0081] determining a first correction coefficient according to a first preset value associated with the first temperature range;

[0082] determining a second temperature interval within which the second difference lies;

[0083] A second correction coefficient is determined according to a second preset value associated with the second temperature range.

[0084] When the processor 1001 calls the control program of the heat pump system stored in the memory 1005, it also performs the following operations:

[0085] determining the energy demand corresponding to the water-side heat exchanger according to the first correction coefficient, the second correction coefficient, and the rated capacity of the heat pump system;

[0086] The target frequency is determined according to the energy demand corresponding to the water-side heat exchanger.

[0087] When the processor 1001 calls the control program of the heat pump system stored in the memory 1005, it also performs the following operations:

[0088] When the heat pump system has a water-side heat exchanger, the target frequency is determined according to the energy demand corresponding to the water-side heat exchanger;

[0089] When the heat pump system has at least two water-side heat exchangers, the total energy demand is determined according to the energy demand corresponding to each of the water-side heat exchangers, and the target frequency is determined according to the total energy demand.

[0090] When the processor 1001 calls the control program of the heat pump system stored in the memory 1005, it also performs the following operations:

[0091] Get the current ambient temperature;

[0092] The target frequency is determined according to the current ambient temperature, the first correction factor, the second correction factor, and the rated capacity of the heat pump system.

[0093] When the processor 1001 calls the control program of the heat pump system stored in the memory 1005, it also performs the following operations:

[0094] Determine a third temperature interval in which the current ambient temperature falls;

[0095] determining a third correction coefficient and a fourth correction coefficient according to the third temperature range;

[0096] The target frequency is determined according to the current ambient temperature, the first correction factor, the second correction factor, the third correction factor, the fourth correction factor, and the rated capacity of the heat pump system.

[0097] When the processor 1001 calls the control program of the heat pump system stored in the memory 1005, it also performs the following operations:

[0098] Get the current operating frequency of the compressor;

[0099] Determine the frequency interval in which the current operating frequency is located;

[0100] determining a preset frequency adjustment period associated with the frequency interval;

[0101] The current operating frequency of the compressor is adjusted to the target frequency based on the preset frequency adjustment period.

[0102] When the processor 1001 calls the control program of the heat pump system stored in the memory 1005, it also performs the following operations:

[0103] When the target frequency is greater than a first preset operating frequency, controlling the compressor to operate at the first preset operating frequency;

[0104] When the target frequency is less than a second preset operating frequency, controlling the compressor to operate at the second preset operating frequency, wherein the first preset operating frequency is greater than the second preset operating frequency;

[0105] When the target frequency is between the first preset operating frequency and the second preset operating frequency, the compressor is controlled to operate at the target frequency.

[0106] Based on the same inventive concept, the present application also proposes a hot and cold water unit, which includes a heat pump system and a water circulation system. The water circulation system includes a water-side heat exchanger, a water pump, and a utilization-side heat exchanger. The utilization-side heat exchanger is used to exchange heat with the air in the working space, and the water pump is used to drive water to circulate between the water-side heat exchanger, the water pump, and the utilization-side heat exchanger. For example, in cooling mode, the refrigerant flows through the compressor, four-way valve, utilization-side heat exchanger, throttling component, water-side heat exchanger, four-way valve, and compressor. In heating mode, the refrigerant flows through the compressor, four-way valve, water-side heat exchanger, throttling component, utilization-side heat exchanger, four-way valve, and compressor.

[0107] The technical solution of this application will be described in detail below by way of embodiments.

[0108] like Figure 3 As shown, in the first embodiment of the present application, the control method of the heat pump system of the present application includes the following steps:

[0109] Step S110 , obtaining a first difference between the outlet water temperature and the inlet water temperature of the heat pump system, and a second difference between the outlet water temperature and the target water temperature.

[0110] In this embodiment, the water side heat exchanger is also referred to as the indoor heat exchanger, the user side heat exchanger or the indoor heat exchanger. Figure 1 The main components of the heat pump system of this application include: compressor 1, water side heat exchanger 2, four-way valve 3, throttling component 4, heat source side heat exchanger 5, etc. The refrigerant flow direction in the heating operation mode is shown by the solid line, and the refrigerant flow direction in the cooling operation mode is shown by the dotted line.

[0111] In this embodiment, in order to solve the problem of large water temperature fluctuations on the user side caused by frequent start-up and shutdown of the compressor, the present application proposes a control method for a heat pump system. The control method of the heat pump system includes: calculating the system energy demand correction coefficient based on the inlet and outlet water temperature difference between the outlet water temperature and the inlet water temperature, and the difference between the outlet water temperature and the target water temperature, and then calculating the system energy demand in combination with the rated capacity of the heat pump system, and then calculating the target operating frequency of the compressor based on the energy demand.

[0112] In this embodiment, temperature sensors may be provided at the water outlet and water inlet of the water-side heat exchanger, respectively, for collecting the temperatures of the water outlet and water inlet, respectively. Optionally, a first temperature sensor may be used to collect the outlet water temperature of the water outlet of the water-side heat exchanger; and a second temperature sensor may be used to collect the inlet water temperature of the water inlet of the water-side heat exchanger. In order to improve the accuracy of the operating frequency of the compressor, the collected outlet water temperature of the water outlet and the inlet water temperature of the water inlet need to be transmitted to the control device at the same time. Optionally, the outlet water temperature of the water outlet and the inlet water temperature of the water inlet of the water-side heat exchanger may be collected at preset time intervals. The preset time may be set according to actual conditions, for example, 5 seconds, 1 minute, etc. Optionally, the collected water outlet temperature and water inlet temperature at the water side heat exchanger's water inlet can be sent to the control device at preset intervals. For example, the water outlet temperature and water inlet temperature of the water side heat exchanger are collected at each moment within the preset interval, and then the collected water outlet temperature and water inlet temperature at all moments within the preset interval are sent to the control device. Optionally, the average water outlet temperature and the average water inlet temperature can be calculated based on the water outlet temperature and water inlet temperature at each moment within the preset interval, and then the average water outlet temperature and the average water inlet temperature can be sent to the control device at preset intervals, thereby improving the measurement accuracy of the water inlet temperature and the water outlet temperature.

[0113] In this embodiment, both the first temperature sensor and the second temperature sensor can be connected to the control device. After receiving the outlet water temperature and the inlet water temperature of the water side heat exchanger in real time, the control device determines the difference between the outlet water temperature and the inlet water temperature of the water side heat exchanger, and records the difference as the first difference. At the same time, the difference between the outlet water temperature of the water side heat exchanger and the target temperature is determined, and the difference is recorded as the second difference. Among them, the target temperature can be set according to actual conditions. In the cooling mode and the heating mode, the target temperature should be set to different values. For example, the inlet water temperature of the water side heat exchanger is recorded as TWin, the outlet water temperature of the water side heat exchanger is recorded as TW, and the target water temperature is recorded as TWS. Then, the first difference ΔTW=TW-Twin between the outlet water temperature and the inlet water temperature of the water side heat exchanger can be calculated, and the difference E_TW=TW-TWS between the outlet water temperature of the water side heat exchanger and the target water temperature can be calculated.

[0114] Step S120 : determining a target frequency according to the first difference, the second difference, and the rated capacity of the heat pump system.

[0115] In this embodiment, after the first difference and the second difference are determined, it is necessary to further determine the target frequency according to the first difference, the second difference and the rated capacity of the heat pump system.

[0116] Optionally, determining the target frequency according to the first difference, the second difference, and the rated capacity of the heat pump system specifically includes:

[0117] Step S121, determining a correction coefficient according to the first difference and the second difference;

[0118] Step S122: determining the target frequency according to the correction coefficient and the rated capacity of the heat pump system.

[0119] Optionally, in the process of determining the target frequency, in order to improve the accuracy of the target frequency, the target frequency needs to be corrected. Therefore, it is necessary to determine a correction coefficient. The correction coefficient includes a first correction coefficient and a second correction coefficient. The first correction coefficient can be determined according to the first difference, and the second correction coefficient can be determined according to the second difference. Optionally, determining the correction coefficient according to the first difference and the second difference is specifically as follows: determining the first temperature interval where the first difference is located; determining the first correction coefficient according to the first preset value associated with the first temperature interval; determining the second temperature interval where the second difference is located; determining the second correction coefficient according to the second preset value associated with the second temperature interval. Optionally, when the first difference is different, the first correction coefficient is also different, and when the second difference is different, the second correction coefficient is also different. The corresponding correction coefficient can be obtained and used for fine adjustment, thereby improving the energy demand adjustment accuracy of the water-side heat exchanger. The first correction coefficient can be determined according to the first difference in Table 1:

[0120] Table 1

[0121] △TW K1 △TW>-3.0℃ 1.02 -7.0℃<△TW≤-3.0℃ 1.0 -10.0℃<△TW≤-7.0℃ 0.8 △TW≤-10.0℃ 0.5

[0122] For example, when the first difference is -2.0° C., it is determined that the first temperature interval in which the first difference is located is ΔTW>-3.0° C., and the first preset value 1.02 associated with the first temperature interval is determined as the first correction coefficient.

[0123] The second correction coefficient can be determined according to the second difference in Table 2:

[0124] Table 2

[0125] E_TW K2 E_TW>6℃ 1.1 3℃<E_TW≤6℃ 1 -1℃<E_TW≤3℃ 0.7 E_TW≤-1℃ 0

[0126] For example, when the second difference is 7° C., it is determined that the second temperature interval in which the second difference is located is E_TW>6° C., and the second preset value 1.1 associated with the second temperature interval is determined as the second correction coefficient.

[0127] Optionally, determining the target frequency according to the correction coefficient and the rated capacity of the heat pump system may include:

[0128] Step S1221, determining the energy demand corresponding to the water-side heat exchanger according to the first correction coefficient, the second correction coefficient, and the rated capacity of the heat pump system;

[0129] Step S1222: determining the target frequency according to the energy demand corresponding to the water-side heat exchanger.

[0130] In this embodiment, when the correction coefficient includes a first correction coefficient and a second correction coefficient, after determining the first correction coefficient and the second correction coefficient, the energy demand of the water-side heat exchanger can be determined based on the first correction coefficient, the second correction coefficient and the rated capacity of the heat pump system. The rated capacity can be preset according to the heat pump system. The target frequency is then determined based on the energy demand corresponding to the water-side heat exchanger. The target frequency is the target operating frequency of the compressor. Optionally, the energy demand of the corresponding water-side heat exchanger can be determined by multiplying the first correction coefficient, the second correction coefficient and the rated capacity of the heat pump system. The target frequency is then determined based on the energy demand. Optionally, the energy demand of the water-side heat exchanger can be determined by multiplying the first correction coefficient, the second correction coefficient and the rated capacity of the heat pump system. The target frequency is then determined based on the energy demand. Optionally, the energy demand of the water-side heat exchanger can be determined using the formula Qwn=Qwcrating*K1*K2, where Qwcrating is the rated capacity of the heat pump system, K1 is the first correction coefficient, and K2 is the second correction coefficient.

[0131] Optionally, the step of determining the target frequency based on the energy demand corresponding to the water-side heat exchanger further includes determining the target frequency based on the number of water-side heat exchangers and the energy demand corresponding to each water-side heat exchanger. Optionally, when the heat pump system has one water-side heat exchanger, the target frequency is determined based on the energy demand corresponding to the water-side heat exchanger; when the heat pump system has at least two water-side heat exchangers, the total energy demand is determined based on the energy demand corresponding to each water-side heat exchanger, and the target frequency is determined based on the total energy demand.

[0132] Step S130: Control the compressor of the heat pump system to operate according to the target frequency.

[0133] In this embodiment, after the target frequency is determined, the compressor of the heat pump system may be further controlled to operate according to the target frequency.

[0134] Optionally, controlling the compressor of the heat pump system to operate according to the target frequency specifically includes: when the target frequency is greater than a first preset operating frequency, controlling the compressor to operate at the first preset operating frequency; when the target frequency is less than a second preset operating frequency, controlling the compressor to operate at the second preset operating frequency, wherein the first preset operating frequency is greater than the second preset operating frequency; when the target frequency is between the first preset operating frequency and the second preset operating frequency, controlling the compressor to operate at the target frequency. For example, the target frequency of the compressor is adjusted to the current actual operating frequency + the total frequency adjustment amount. If the adjusted target frequency is greater than the first preset operating frequency (preset maximum frequency), the compressor operates at the first preset operating frequency (preset maximum frequency); if the adjusted target frequency is less than the second preset operating frequency (preset minimum frequency), the compressor operates at the second preset operating frequency (preset minimum frequency).

[0135] Optionally, determining the target frequency according to the correction coefficient and the rated capacity of the heat pump system may further include the following steps:

[0136] Step S221, obtaining the current ambient temperature;

[0137] Step S222: determining the target frequency according to the current ambient temperature, the first correction coefficient, the second correction coefficient, and the rated capacity of the heat pump system.

[0138] In this embodiment, the current ambient temperature is the external ambient temperature. A third temperature sensor may be used to obtain the current ambient temperature, and the target frequency may be determined based on the current ambient temperature, the first correction coefficient, the second correction coefficient, and the rated capacity of the heat pump system. Alternatively, the energy demand corresponding to the water-side heat exchanger of the heat pump system may be determined based on the product of the first correction coefficient, the second correction coefficient, and the rated capacity of the heat pump system. Furthermore, the target frequency may be determined based on the current ambient temperature and the energy demand corresponding to the water-side heat exchanger of the heat pump system. If there are multiple water-side heat exchangers, the target frequency may be determined based on the current ambient temperature and the total energy demand of all water-side heat exchangers of the heat pump system.

[0139] Optionally, the step of determining the target frequency according to the current ambient temperature, the first correction coefficient, the second correction coefficient, and the rated capacity of the heat pump system includes:

[0140] Step S2221, determining the third temperature interval in which the current ambient temperature is located;

[0141] Step S2222, determining a third correction coefficient and a fourth correction coefficient according to the third temperature range;

[0142] Step S2223 : determining the target frequency according to the current ambient temperature, the first correction coefficient, the second correction coefficient, the third correction coefficient, the fourth correction coefficient, and the rated capacity of the heat pump system.

[0143] In this embodiment, the third temperature interval in which the current ambient temperature is located can be obtained, and the third correction coefficient and the fourth correction coefficient associated with the third temperature interval can be determined. The target frequency can be determined based on the current ambient temperature, the first correction coefficient, the second correction coefficient, the third correction coefficient, the fourth correction coefficient and the rated capacity of the heat pump system, wherein the current ambient temperature is the temperature of the environment in which the heat exchanger on the heat source side is located, for example, the outdoor ambient temperature. Optionally, the energy demand corresponding to the water-side heat exchanger of the heat pump system can be determined based on the first correction coefficient, the second correction coefficient and the rated capacity of the heat pump system. The target frequency is determined based on the energy demand and the third correction coefficient and the fourth correction coefficient. Optionally, the target frequency of the compressor can be determined using the formula Fr=K3*Qwn+K4=K3*(Qwcrating*K1*K2)+K4. Wherein, K3 is the third correction coefficient and K4 is the fourth correction coefficient, and the third correction coefficient and the fourth correction coefficient can be determined based on the current ambient temperature. For example, the third correction coefficient and the fourth correction coefficient can be determined according to Table 3:

[0144] Table 3

[0145] T4 K3 K4 T4＞40℃ 2 4 25℃＜T4≤40℃ 4 8 15℃＜T4≤25℃ 3 6 T4≤15℃ 1 2

[0146] For example, when the current ambient temperature is 40°C, it is determined that the third temperature interval in which the current ambient temperature is located is T4>40°C, then the third correction coefficient K3=2 and the fourth correction coefficient K4=4 associated with T4>40°C can be obtained, and the target frequency of the compressor Fr=2*Qw+4=2*(Qwcrating*K1*K2)+4.

[0147] Optionally, after determining the target frequency according to the first difference, the second difference and the rated capacity of the heat pump system, the method further includes the following steps:

[0148] Step S310, obtaining the current operating frequency of the compressor;

[0149] Step S320, determining the frequency interval in which the current operating frequency is located;

[0150] Step S330, determining a preset frequency adjustment period associated with the frequency interval;

[0151] The step of controlling the compressor of the heat pump system to operate according to the target frequency includes:

[0152] Step S231: adjusting the current operating frequency of the compressor to the target frequency based on the preset frequency adjustment period.

[0153] In this embodiment, the current operating frequency of the compressor can be obtained in real time. According to the interval in which the current operating frequency of the compressor is located, the energy required by each internal machine and the calculation period TWM of the frequency adjustment amount of each internal machine for the compressor are determined. Optionally, the operating frequency of the compressor can be adjusted every frequency adjustment period TWM, and the frequency adjustment period TWM is determined by the current operating frequency of the compressor. The interval in which the current operating frequency is located can be determined, and then the preset frequency adjustment period TWM associated with the interval can be determined as the frequency adjustment period TWM. The frequency adjustment period TWM can be determined according to Table 3-4:

[0154] Table 3-4

[0155] Fr Fr＜30 30≤Fr＜60 Fr≥60 TMW (seconds) 100 80 60

[0156] For example, when the current operating frequency of the compressor is 20, it is determined that the frequency interval of the current operating frequency is Fr<30, and the compressor operating frequency of the heat pump system is adjusted to the target frequency every 100 seconds using the determined total frequency adjustment amount.

[0157] Optionally, in one embodiment, referring to Figure 4After obtaining the inlet water temperature TWin, outlet water temperature TW, and target water temperature TWS, the inlet and outlet water temperature difference ΔTW = TW - TWin is calculated, as well as the difference between the outlet water temperature and the target water temperature ΔE_TW = TW - TWS. A first correction coefficient K1 is determined based on ΔTW, and a second correction coefficient K2 is determined based on ΔE_TW. Simultaneously, the rated capacity Qwcrating of the heat pump system preset in the control module is obtained. The energy demand Qw of the heat pump system is determined based on the first and second correction coefficients and the rated capacity of the heat pump system. Furthermore, the target frequency Fr of the compressor is determined based on the energy demand Qw of the heat pump system.

[0158] According to the above technical solution, the present application can calculate the target operating frequency of the compressor based on the inlet and outlet water temperature difference, the difference between the outlet water temperature and the target water temperature, and the rated capacity of the system, so that the compressor operating frequency is matched with the actual load, avoiding frequent start and stop of the compressor, making the system more reliable and more energy-efficient, and the temperature fluctuation on the user side is smaller, thereby improving the comfort of use.

[0159] The embodiments of the present invention provide embodiments of a method for controlling a heat pump system. It should be noted that although a logical order is shown in the flow chart, in some cases, the steps shown or described may be performed in an order different from that shown here.

[0160] Based on the same inventive concept, an embodiment of the present application further provides a computer-readable storage medium, which stores a control program for a heat pump system. When the control program for the heat pump system is executed by a processor, the control program for the heat pump system implements the various steps of the control method for the heat pump system described above and can achieve the same technical effect. To avoid repetition, it will not be described here.

[0161] Since the storage medium provided in the embodiments of this application is the storage medium used to implement the method of the embodiments of this application, those skilled in the art will be able to understand the specific structure and variations of the storage medium based on the method described in the embodiments of this application, and therefore will not be described in detail here. All storage media used in the method of the embodiments of this application fall within the scope of protection to be provided by this application.

[0162] It will be understood by those skilled in the art that embodiments of the present invention may be provided as methods, systems, or computer program products. Thus, the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware. Furthermore, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to magnetic disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0163] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowcharts and / or block diagrams, as well as combinations of processes and / or blocks in the flowcharts and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowcharts and / or block diagrams. Figure 1 a process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0164] These computer program instructions may also be stored in a computer readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 a process or multiple processes and / or boxes Figure 1 The function specified in one or more boxes.

[0165] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operational steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing the instructions executed on the computer or other programmable device for implementing the process. Figure 1 a process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0166] It should be noted that in the claims, any reference signs placed between parentheses shall not be construed as limiting the claims. The word "comprising" does not exclude the presence of components or steps not listed in the claim. The word "a" or "an" preceding a component does not exclude the presence of a plurality of such components. The invention can be implemented by means of hardware comprising several different components and by means of a suitably programmed computer. In a unit claim enumerating several means, several of these means may be embodied by one and the same item of hardware. The use of the words first, second, third etc. does not indicate any order. These words may be interpreted as names.

[0167] Although the preferred embodiments of the present invention have been described, those skilled in the art may make additional changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

[0168] Obviously, those skilled in the art may make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if such changes and modifications fall within the scope of the claims and their equivalents, the present invention is intended to include such changes and modifications.

Claims

1. A control method for a heat pump system, characterized in that: Applied to a heat pump system, the heat pump system includes a water-side heat exchanger, and the method includes: Obtaining a first difference between an outlet water temperature and an inlet water temperature of the heat pump system, and a second difference between the outlet water temperature and a target water temperature; determining a first temperature interval within which the first difference value lies; determining a first correction coefficient according to a first preset value associated with the first temperature range; determining a second temperature interval within which the second difference lies; determining a second correction coefficient according to a second preset value associated with the second temperature range; determining the energy demand corresponding to the water-side heat exchanger according to the first correction coefficient, the second correction coefficient, and the rated capacity of the heat pump system; Determining the target frequency according to the energy demand corresponding to the water-side heat exchanger; The compressor of the heat pump system is controlled to operate according to the target frequency.

2. The method according to claim 1, wherein The step of determining the target frequency according to the energy demand corresponding to the water-side heat exchanger includes: When the heat pump system has a water-side heat exchanger, the target frequency is determined according to the energy demand corresponding to the water-side heat exchanger; When the heat pump system has at least two water-side heat exchangers, the total energy demand is determined according to the energy demand corresponding to each of the water-side heat exchangers, and the target frequency is determined according to the total energy demand.

3. The method according to claim 1, wherein After determining the second correction coefficient according to the second preset value associated with the second temperature range, the method further includes: Get the current ambient temperature; The target frequency is determined according to the current ambient temperature, the first correction coefficient, the second correction coefficient, and the rated capacity of the heat pump system, so as to control the compressor of the heat pump system to operate according to the target frequency.

4. The method according to claim 3, wherein The step of determining the target frequency according to the current ambient temperature, the first correction coefficient, the second correction coefficient, and the rated capacity of the heat pump system includes: Determine a third temperature interval in which the current ambient temperature falls; determining a third correction coefficient and a fourth correction coefficient according to the third temperature range; The target frequency is determined according to the current ambient temperature, the first correction factor, the second correction factor, the third correction factor, the fourth correction factor, and the rated capacity of the heat pump system.

5. The method according to claim 1, wherein After determining the target frequency, it also includes: Get the current operating frequency of the compressor; Determine the frequency interval in which the current operating frequency is located; determining a preset frequency adjustment period associated with the frequency interval; The step of controlling the compressor of the heat pump system to operate according to the target frequency includes: The current operating frequency of the compressor is adjusted to the target frequency based on the preset frequency adjustment period.

6. The method according to claim 1, wherein Controlling the compressor of the heat pump system to operate according to the target frequency includes: When the target frequency is greater than a first preset operating frequency, controlling the compressor to operate at the first preset operating frequency; When the target frequency is less than a second preset operating frequency, controlling the compressor to operate at the second preset operating frequency, wherein the first preset operating frequency is greater than the second preset operating frequency; When the target frequency is between the first preset operating frequency and the second preset operating frequency, the compressor is controlled to operate at the target frequency.

7. A heat pump system, characterized in that: The heat pump system comprises: compressor; The water-side heat exchanger is disposed between the four-way valve and the throttling component and is configured as a component for exchanging heat between water and refrigerant; a four-way valve, disposed on a refrigerant circuit and configured to adjust a refrigerant flow direction of the refrigerant circuit; a throttling component connected to an output end of the water-side heat exchanger; a heat source side heat exchanger, disposed between the four-way valve and the throttling component, configured as a component for exchanging heat between the refrigerant and the heat source side medium; A control device, the control device comprising: a memory, a processor, and a control program for a heat pump system stored in the memory and executable on the processor, wherein the control program for the heat pump system, when executed by the processor, implements the steps of a control method for a heat pump system as described in any one of claims 1 to 6.

8. A hot and cold water unit, characterized in that: include The heat pump system according to claim 7; and A water circulation system, the water circulation system includes the water-side heat exchanger, a water pump and a utilization-side heat exchanger, the utilization-side heat exchanger is used to exchange heat with the air in the action space, and the water pump is used to drive water to circulate between the water-side heat exchanger, the water pump and the utilization-side heat exchanger.

9. A computer-readable storage medium, characterized in that The computer-readable storage medium stores a control program of the heat pump system, and when the control program of the heat pump system is executed by a processor, the steps of the control method of the heat pump system according to any one of claims 1 to 6 are implemented.

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