Control method, household water machine and computer readable storage medium

Abstract

The application discloses a control method of a water-side heat exchanger of a household water machine. When the water-side heat exchanger operates in a refrigeration mode, the refrigerant pressure in the water-side heat exchanger is obtained. When the refrigerant pressure is less than a first predetermined threshold, the unit containing the water-side heat exchanger is controlled to exit the refrigeration mode. According to the control method, the unit containing the water-side heat exchanger can exit the refrigeration mode in time according to the refrigerant pressure in the water-side heat exchanger of the household water machine in the refrigeration mode, so that the low pressure of the low-temperature refrigerant is prevented from being too low to reduce the evaporation temperature, and thus the water in the water-side heat exchanger performing heat exchange with the refrigerant is prevented from freezing. Therefore, the water-side heat exchanger can be effectively protected, and the service life of the household water machine is prolonged.

Description

Technical Field

[0001] This application relates to the field of air conditioning control, specifically to a control method, a residential water heater, and a computer-readable storage medium. Background Technology

[0002] A residential water chiller consists of a water-side heat exchanger, an air-side heat exchanger, and a water circulation system. The water circulation system exchanges heat with the water-side heat exchanger and is installed indoors as a heating or cooling system. During operation, the water circulation system exchanges heat with the water-side heat exchanger to provide heating or cooling for the room. When the water-side heat exchanger is operating in cooling mode, the evaporation temperature of the internal refrigerant decreases, and the water exchanging heat with it is prone to freezing, leading to freezing and leakage damage to the water-side heat exchanger, ultimately rendering the entire residential water chiller unusable. Summary of the Invention

[0003] This application provides a control method, a household water heater, and a computer-readable storage medium.

[0004] The control method of this application, used for residential water systems, includes:

[0005] The refrigerant pressure inside the water-side heat exchanger of the household water heater is obtained when the water-side heat exchanger is operating in cooling mode.

[0006] When the refrigerant pressure is less than a first predetermined threshold, the unit containing the water-side heat exchanger is controlled to exit the cooling mode.

[0007] In summary, the control method of this application can control the unit containing the water-side heat exchanger to exit the cooling mode in a timely manner according to the pressure of the refrigerant inside the water-side heat exchanger of the household water heater in the cooling mode. This prevents the low pressure of the low-temperature refrigerant from causing its evaporation temperature to drop, which would lead to the water in the water-side heat exchanger that exchanges heat with the refrigerant freezing. In this way, the water-side heat exchanger can be effectively protected, thereby extending the service life of the household water heater.

[0008] The process of obtaining the refrigerant pressure within the water-side heat exchanger includes:

[0009] Obtain the refrigerant pressure within the water-side heat exchanger that exchanges heat with the water circulation system.

[0010] In this way, by obtaining the rated refrigerant pressure inside the water-side heat exchanger that exchanges heat with the water circulation system, and controlling the compressor's operating frequency based on the refrigerant pressure inside the water-side heat exchanger, the water inside the water-side heat exchanger that exchanges heat with the refrigerant can be prevented from freezing, effectively protecting the water-side heat exchanger and thus extending the service life of the household water purifier.

[0011] The control method of this application includes:

[0012] When the refrigerant pressure is greater than or equal to the first predetermined threshold and less than the second predetermined threshold, the minimum frequency limit of the compressor is reduced.

[0013] Thus, the residential water chiller determines the minimum frequency limit of the compressor based on the temperature set by the user. If the frequency limit is lower than the minimum, the user may not be able to reach the set temperature. However, even though the compressor is operating at the minimum frequency limit, the refrigerant pressure is still low, and there is a risk of the water in the water-side heat exchanger freezing. To avoid this, lowering the minimum frequency limit of the compressor allows the compressor to operate at a lower frequency, thereby increasing the refrigerant pressure and preventing the compressor from shutting down while protecting the water-side heat exchanger.

[0014] The control method of this application includes:

[0015] When the refrigerant pressure is greater than or equal to the second predetermined threshold and less than the third predetermined threshold, the operating frequency of the compressor is reduced every predetermined time interval.

[0016] Thus, although the refrigerant pressure is higher than the second threshold, it is still low and there is a need to increase the pressure. By reducing the operating frequency of the compressor, the refrigerant pressure can be increased, further ensuring the safety of the water-side heat exchanger.

[0017] The control method of this application includes:

[0018] When the refrigerant pressure is greater than or equal to the third predetermined threshold and less than the fourth predetermined threshold, the current operating frequency of the compressor is limited to the maximum operating frequency.

[0019] Therefore, when the refrigerant pressure is high, there is still a need to control the pressure. Thus, by limiting the current operating frequency to the maximum operating frequency, the compressor can be prevented from increasing its frequency, which would cause the refrigerant pressure to drop and thus induce the water that exchanges heat with the refrigerant to freeze.

[0020] The control method of this application includes:

[0021] When the refrigerant pressure exceeds a fourth predetermined threshold, the operating frequency of the compressor is adjusted according to actual needs.

[0022] In this way, the refrigerant pressure reaches a safe range, and there is no need to limit the compressor's operating frequency. The compressor's operating frequency can be adjusted according to actual needs, such as increasing the compressor's operating frequency. Under these circumstances, the water that exchanges heat with the refrigerant in the water-side heat exchanger can be prevented from freezing, effectively protecting the water-side heat exchanger and thus extending the service life of the residential water purifier.

[0023] The step of controlling the unit containing the water-side heat exchanger to exit the cooling mode when the refrigerant pressure is less than a first predetermined threshold includes:

[0024] Turn off the household water purifier.

[0025] Therefore, when the refrigerant pressure is too low, it is impossible to increase the refrigerant pressure by reducing the compressor's operating frequency. Thus, shutting down the residential water heater is the best way to ensure the safety of the water-side heat exchanger.

[0026] The method of obtaining the refrigerant pressure within the water-side heat exchanger when the water-side heat exchanger of the residential water heater is operating in cooling mode includes:

[0027] When the household water purifier is in defrost mode, the outlet water temperature of the water circulation system that exchanges heat with the water-side heat exchanger is obtained.

[0028] The step of controlling the unit containing the water-side heat exchanger to exit the cooling mode when the refrigerant pressure is less than a first predetermined threshold includes:

[0029] When the duration for which the outlet water temperature is lower than the first preset temperature and the pressure is lower than the first preset pressure reaches a first duration threshold, the household water purifier is controlled to exit the defrosting mode.

[0030] When the duration for which the outlet water temperature is greater than or equal to the first preset temperature and the pressure is less than the second preset pressure reaches a second duration threshold, the household water purifier is controlled to exit the defrost mode, wherein the second preset pressure is greater than the first preset pressure and the first duration threshold is less than or equal to the second duration threshold.

[0031] In this way, the operating frequency of the compressor can be controlled according to the outlet water temperature and corresponding pressure of the water-side heat exchanger, preventing the water exchanging heat with the refrigerant in the water-side heat exchanger from freezing, effectively protecting the water-side heat exchanger, and thus extending the service life of the household water chiller.

[0032] The method of obtaining the refrigerant pressure within the water-side heat exchanger when the water-side heat exchanger of the residential water heater is operating in cooling mode includes:

[0033] When the household water heater is started and the unit is about to switch from the cooling mode to the heating mode, the ambient temperature and the outlet water temperature of the water circulation system that exchanges heat with the water-side heat exchanger are obtained.

[0034] The step of controlling the unit containing the water-side heat exchanger to exit the cooling mode when the refrigerant pressure is less than a first predetermined threshold includes:

[0035] When the ambient temperature is greater than the second preset temperature and the return water temperature is greater than the third preset temperature, the compressor of the household water purifier is started after a third time threshold, and the four-way valve of the household water purifier is switched.

[0036] When the ambient temperature is less than or equal to the second preset temperature or the return water temperature is less than or equal to the third preset temperature, the compressor is started after a fourth time threshold is set, and the four-way valve is controlled to switch, wherein the fourth time threshold is less than or equal to the third time threshold.

[0037] In this way, the switching of the four-way valve of the air conditioning unit can be controlled according to the ambient temperature of the water-side heat exchanger, the return water temperature, and the compressor working time, so as to change the working state of the household water system and prevent the water-side heat exchanger from freezing.

[0038] The household water purifier of this application includes a controller, which implements the control method described in the above embodiments.

[0039] The computer-readable storage medium of this application stores a computer program that, when executed by one or more processors, implements the test and evaluation method as described in the above embodiments.

[0040] Additional aspects and advantages of embodiments of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of embodiments of this application. Attached Figure Description

[0041] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the following description of the embodiments taken in conjunction with the accompanying drawings, wherein:

[0042] Figure 1 This is a flowchart illustrating the testing and evaluation method in the embodiments of this application;

[0043] Figure 2 This is a structural schematic diagram of the household water dispenser in the embodiments of this application;

[0044] Figure 3 This is a flowchart illustrating the testing and evaluation method in the embodiments of this application;

[0045] Figure 4 This is a flowchart illustrating the testing and evaluation method in the embodiments of this application;

[0046] Figure 5 This is a flowchart illustrating the testing and evaluation method in the embodiments of this application;

[0047] Figure 6 This is a flowchart illustrating the testing and evaluation method in the embodiments of this application;

[0048] Figure 7 This is a flowchart illustrating the testing and evaluation method in the embodiments of this application;

[0049] Figure 8This is a flowchart illustrating the testing and evaluation method in the embodiments of this application;

[0050] Figure 9 This is a flowchart illustrating the testing and evaluation method in the embodiments of this application;

[0051] Figure 10 This is a flowchart illustrating the testing and evaluation method in the embodiments of this application;

[0052] Figure 11 This is a flowchart illustrating the testing and evaluation method in the embodiments of this application;

[0053] Figure 12 This is a flowchart illustrating the testing and evaluation method in the embodiments of this application. Detailed Implementation

[0054] The embodiments of this application are described in detail below. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the embodiments of this application, and should not be construed as limiting the embodiments of this application.

[0055] In related technologies, residential water chillers use a water circulation system that exchanges heat with a water-side heat exchanger to provide indoor heating or cooling. When the water-side heat exchanger is operating in cooling mode, the internal refrigerant pressure is too low, causing its evaporation temperature to drop. Under these conditions, the water in the water-side heat exchanger that exchanges heat with the refrigerant is prone to freezing. Since the volume of frozen water increases, it can cause the water-side heat exchanger to freeze and leak, leading to its failure and rendering the entire residential water chiller unusable.

[0056] Based on the above, such as Figure 1 As shown, the control method for a household water dispenser in this application includes:

[0057] 01: Obtain the refrigerant pressure inside the water-side heat exchanger when the water-side heat exchanger of the household water heater is operating in cooling mode;

[0058] 02: When the refrigerant pressure is less than the first predetermined threshold, control the unit containing the water-side heat exchanger to exit the cooling mode.

[0059] This application also provides a residential water heater, including a controller. The control system method of this application can be implemented by the controller of this application. Specifically, the controller is used to acquire the refrigerant pressure in the water-side heat exchanger when the water-side heat exchanger of the residential water heater is operating in cooling mode, and to control the unit containing the water-side heat exchanger to exit cooling mode when the refrigerant pressure is less than a first predetermined threshold.

[0060] Specifically, such as Figure 2 The diagram shown illustrates one possible structure of a residential water-cooled chiller. In this embodiment, the chiller includes an air-side heat exchanger, a water-side heat exchanger, and a water circulation system. The air-side heat exchanger is connected to the compressor, expansion valve, and one end of the water-side heat exchanger, forming a heat pump unit with refrigerant circulation. The other end of the water-side heat exchanger enters the water circulation system, connecting to the room for indoor heating. The water circulation system may also contain a water pump or other hot water storage device to ensure a consistently smooth and stable flow of water within the system.

[0061] In a residential water chiller, refrigerant and water exchange heat in a water-side heat exchanger. When the unit, which includes a water-side heat exchanger, is operating in cooling mode, the refrigerant pressure within the heat exchanger can be controlled within a certain range, thereby controlling the cooling effect of the equipment. This unit can be an air conditioning unit. Limiting the refrigerant pressure helps prevent the water exchanging heat with the refrigerant in the heat exchanger from freezing, which could lead to irreversible damage to the entire residential water chiller.

[0062] When the refrigerant pressure is lower than a first predetermined threshold, the excessively low refrigerant pressure will cause the water in the water-side heat exchanger to freeze at the same temperature, thereby damaging the water-side heat exchanger. The first predetermined threshold can be set to 0.4 MPa or other similar values; the specific value of the first predetermined threshold is not limited here. When the refrigerant pressure is less than 0.4 MPa, the unit will exit cooling mode to prevent the water in the water-side heat exchanger from freezing due to excessive cooling time, which could damage the residential water chiller.

[0063] In summary, the control method of this application can control the unit containing the water-side heat exchanger to exit the cooling mode in a timely manner according to the pressure of the refrigerant inside the water-side heat exchanger of the household water heater in the cooling mode. This prevents the low pressure of the low-temperature refrigerant from causing its evaporation temperature to drop, which would lead to the water in the water-side heat exchanger that exchanges heat with the refrigerant freezing. This can effectively protect the water-side heat exchanger and thus extend the service life of the household water heater.

[0064] In some implementations, please refer to Figure 3 Step 01 includes:

[0065] 011: Obtain the refrigerant pressure in the water-side heat exchanger that exchanges heat with the water circulation system.

[0066] In some implementations, the controller is used to acquire the refrigerant pressure of the water circulation system that exchanges heat with the water-side heat exchanger.

[0067] Specifically, heat exchange occurs between the water-side heat exchanger and the water circulation system in a residential water chiller. The water circulation system is the part of the chiller that directly or indirectly exchanges heat with the user's indoor environment, such as underfloor heating or fan coil units. Due to the nature of the heat exchange, there is a certain correlation between the refrigerant pressure in the water-side heat exchanger and the outlet water temperature of the water circulation system. The outlet water temperature of the water circulation system, viewed from the user's perspective, provides a more direct indication of the cooling effect on the user's side, and the outlet water temperature can be controlled by the user, which is more convenient than controlling the refrigerant pressure.

[0068] However, it should be noted that because the heat exchange between the water-side heat exchanger and the water circulation system is insufficient to establish a strong correlation between refrigerant pressure and outlet water temperature, the refrigerant pressure within the water-side heat exchanger cannot be accurately inferred from the outlet water temperature of the water circulation system. Therefore, directly obtaining the refrigerant pressure within the water-side heat exchanger is a more reliable basis for controlling the exit of cooling mode for units containing water-side heat exchangers, rather than obtaining the outlet water temperature of the water circulation system.

[0069] In this way, by obtaining the rated refrigerant pressure inside the water-side heat exchanger that exchanges heat with the water circulation system, and controlling the compressor's operating frequency based on the refrigerant pressure inside the water-side heat exchanger, the water inside the water-side heat exchanger that exchanges heat with the refrigerant can be prevented from freezing, effectively protecting the water-side heat exchanger and thus extending the service life of the household water purifier.

[0070] In some implementations, please refer to Figure 4 The control method of this application also includes:

[0071] 03: When the refrigerant pressure is greater than or equal to the first predetermined threshold and less than the second predetermined threshold, reduce the minimum frequency limit of the compressor.

[0072] In some implementations, the controller is used to reduce the minimum frequency limit of the compressor when the refrigerant pressure is greater than or equal to a first predetermined threshold and less than a second predetermined threshold.

[0073] Specifically, when the refrigerant pressure in the water-side heat exchanger is greater than or equal to a first predetermined threshold and less than a second predetermined threshold that is slightly larger than the first predetermined threshold, the residential water chiller cannot control the refrigerant pressure within a range that prevents the water exchanging heat with it from freezing, even if the compressor reduces its operating frequency to the minimum. In this case, it is necessary to reduce the compressor's minimum frequency limit so that the compressor can operate at a frequency lower than the current minimum frequency limit.

[0074] For example, in one example, the first predetermined threshold is 0.5 MPa and the second predetermined threshold is 0.6 MPa. When the refrigerant pressure in the water-side heat exchanger is between 0.5 MPa and 0.6 MPa, the minimum operating frequency of the compressor can be adjusted from 50 Hz to 30 Hz. At this time, the compressor can also work between 30 Hz and 50 Hz, which avoids the compressor shutting down and protects the water-side heat exchanger.

[0075] Thus, the residential water chiller determines the minimum frequency limit of the compressor based on the temperature set by the user. If the frequency limit is lower than the minimum, the user may not be able to reach the set temperature. However, even though the compressor is operating at the minimum frequency limit, the refrigerant pressure is still low, and there is a risk of the water in the water-side heat exchanger freezing. To avoid freezing, lowering the minimum frequency limit of the compressor allows the compressor to operate at a lower frequency, thereby increasing the refrigerant pressure and preventing the compressor from shutting down while protecting the water-side heat exchanger.

[0076] In some implementations, please refer to Figure 5 Step 011 includes:

[0077] 04: When the refrigerant pressure is greater than or equal to the second predetermined threshold and less than the third predetermined threshold, the compressor operating frequency is reduced every predetermined time interval.

[0078] In some implementations, the controller is used to reduce the operating frequency of the compressor at predetermined intervals when the refrigerant pressure is greater than or equal to a second predetermined threshold and less than a third predetermined threshold.

[0079] Specifically, when the refrigerant pressure in the water-side heat exchanger is greater than or equal to a second predetermined threshold but less than a third predetermined threshold that is slightly larger than the second predetermined threshold, the compressor of the residential water chiller needs to reduce its operating frequency to control the refrigerant pressure within a range that prevents the water exchanging heat with it from freezing. To improve the user experience, the reduction of the compressor's operating frequency can be set to be done automatically in a gradual manner, without the need for manual adjustment. For example, the compressor's operating frequency can be reduced in a gradual manner at predetermined intervals until the compressor's operating frequency drops to a range that prevents the water from freezing.

[0080] For example, in one example, the second predetermined threshold is 0.6 MPa and the third predetermined threshold is 0.7 MPa. When the refrigerant pressure in the water-side heat exchanger is between 0.6 MPa and 0.7 MPa, the compressor's operating frequency can be reduced by one level every 5 seconds. At this time, by gradually reducing the compressor's operating frequency, the refrigerant pressure can be increased, further preventing the water in the water-side heat exchanger from freezing and threatening the safety of the water-side heat exchanger.

[0081] Thus, although the refrigerant pressure is higher than the second threshold, it is still low and there is a need to increase the pressure. By reducing the operating frequency of the compressor, the refrigerant pressure can be increased, further ensuring the safety of the water-side heat exchanger.

[0082] In some implementations, please refer to Figure 6 The control method of this application also includes:

[0083] 05: When the refrigerant pressure is greater than or equal to the third predetermined threshold and less than the fourth predetermined threshold, the current operating frequency of the compressor is limited to the maximum operating frequency.

[0084] In some implementations, the controller is used to limit the compressor’s current operating frequency to the maximum operating frequency when the refrigerant pressure is greater than or equal to a third predetermined threshold and less than a fourth predetermined threshold.

[0085] Specifically, when the refrigerant pressure in the water-side heat exchanger is greater than or equal to the third predetermined threshold and less than the fourth predetermined threshold which is slightly larger than the fourth predetermined threshold, the cooling intensity of the household water system is relatively high. In order to ensure that the water-side heat exchanger is not damaged by water freezing during the cooling process, the compressor needs to stop increasing its operating frequency. That is, the current operating frequency of the compressor is limited to the highest operating frequency. Therefore, the refrigerant in the water-side heat exchanger will not freeze due to continuous high-frequency cooling.

[0086] For example, in one example, the third predetermined threshold is 0.7 MPa and the fourth predetermined threshold is 0.8 MPa. When the refrigerant pressure inside the water-side heat exchanger is between 0.7 MPa and 0.8 MPa, the compressor needs to be restricted to operate at or below the current operating frequency to prevent the water inside the water-side heat exchanger from freezing due to the continuous increase in compressor frequency. This ensures the safety of the water-side heat exchanger when the refrigerant pressure is high.

[0087] Therefore, when the refrigerant pressure is high, there is still a need to control the pressure. Thus, by limiting the current operating frequency to the maximum operating frequency, the compressor can be prevented from increasing its frequency, which would cause the refrigerant pressure to drop and thus induce the water that exchanges heat with the refrigerant to freeze.

[0088] In some implementations, please refer to Figure 7 The control method of this application also includes:

[0089] 06: When the refrigerant pressure is greater than the fourth predetermined threshold, adjust the compressor's operating frequency according to actual needs.

[0090] In some implementations, the controller is used to adjust the operating frequency of the compressor according to actual needs when the refrigerant pressure is greater than a fourth predetermined threshold.

[0091] Specifically, when the refrigerant pressure in the water-side heat exchanger is greater than or equal to the fourth predetermined threshold, the cooling intensity of the residential water chiller is relatively high. At this time, the refrigerant pressure is high, and the water exchanging heat with the refrigerant is unlikely to freeze. Under these circumstances, unlike when the refrigerant pressure is low, there is no need to sacrifice some user experience to ensure that the water exchanging heat with the refrigerant in the water-side heat exchanger does not freeze during the cooling process. The compressor's operating frequency can be adjusted arbitrarily according to user needs, meaning the residential water chiller operates normally.

[0092] For example, in one scenario, the fourth predetermined threshold is 0.8 MPa. Therefore, when the refrigerant pressure inside the water-side heat exchanger reaches 0.8 MPa or higher, the water exchanging heat with the refrigerant is virtually immune to freezing. Consequently, there is no need to limit the compressor's operating frequency. The compressor's operating frequency can be adjusted arbitrarily according to the user's needs.

[0093] In this way, the refrigerant pressure reaches a safe range, and there is no need to limit the compressor's operating frequency. The compressor's operating frequency can be adjusted according to actual needs, such as increasing the compressor's operating frequency. Under these circumstances, the water that exchanges heat with the refrigerant in the water-side heat exchanger can be prevented from freezing, effectively protecting the water-side heat exchanger and thus extending the service life of the residential water purifier.

[0094] In some implementations, please refer to Figure 8 Step 02 includes:

[0095] 021: Turn off the household water heater.

[0096] In some implementations, the processor is used to shut down the household water system.

[0097] Specifically, in cooling mode, the refrigerant temperature of the water-side heat exchanger is low. If its pressure is also low at this time, for example, below a lower first predetermined threshold, the water-side heat exchanger is prone to damage due to water freezing, causing the entire residential water system to become unusable. Therefore, when the refrigerant pressure is below the first predetermined threshold, it is necessary to control the unit containing the water-side heat exchanger to exit cooling mode, such as by continuously reducing the compressor's operating frequency or directly shutting down the residential water system. When the refrigerant pressure is too low, reducing the compressor's operating frequency is no longer sufficient to prevent water from freezing under the current pressure conditions. In this case, shutting down the residential water system is the most convenient way to ensure the safety of the water-side heat exchanger.

[0098] Therefore, when the refrigerant pressure is too low, it is impossible to increase the refrigerant pressure by reducing the compressor's operating frequency. Thus, shutting down the residential water heater is the best way to ensure the safety of the water-side heat exchanger.

[0099] In some implementations, please refer to Figure 9 Step 01 includes:

[0100] 012: When the household water purifier is in defrost mode, obtain the outlet water temperature of the water circulation system that exchanges heat with the water-side heat exchanger;

[0101] Step 012 includes:

[0102] 0121: When the duration of the water temperature being lower than the first preset temperature and the pressure being lower than the first preset pressure reaches the first duration threshold, control the household water purifier to exit the defrost mode.

[0103] 0122: When the duration of the water temperature being greater than or equal to the first preset temperature and the pressure being less than the second preset pressure reaches the second duration threshold, the household water purifier is controlled to exit the defrost mode.

[0104] In some embodiments, the processor is configured to, when the household water heater is in defrost mode, acquire the outlet water temperature of the water circulation system that exchanges heat with the water-side heat exchanger, and control the household water heater to exit defrost mode when the outlet water temperature is lower than a first preset temperature and the pressure is lower than a first preset pressure for a duration of a first duration threshold, and control the household water heater to exit defrost mode when the outlet water temperature is greater than or equal to the first preset temperature and the pressure is lower than a second preset pressure for a duration of a second duration threshold.

[0105] Specifically, when a residential water chiller is in defrost mode, the temperature of the water-side heat exchanger is low, making it prone to freezing if the refrigerant pressure is not specifically limited, which can damage the water-side heat exchanger. Therefore, the outlet water temperature of the water circulation system that exchanges heat with the water-side heat exchanger can be obtained, while limiting the refrigerant pressure and the duration of maintaining that pressure. This ensures the defrosting function as much as possible while preventing the water exchanging heat with the refrigerant in the water-side heat exchanger from freezing.

[0106] If the water temperature and pressure remain below the first preset temperature and pressure for a duration exceeding the first preset pressure threshold, and the residential water chiller continues to operate in defrost mode, icing may occur in the water-side heat exchanger. The system can be controlled to exit defrost mode. The first preset temperature constrains the water outlet temperature of the water circulation system and is generally the temperature commonly used during refrigeration defrosting; it should not be too low. The first preset pressure is generally 0.1 MPa or higher. The first time threshold is generally less than 2 minutes.

[0107] If the water temperature is greater than or equal to the first preset temperature and the pressure is less than the second preset pressure for a period of time that reaches the second time threshold, the water that exchanges heat with the refrigerant may freeze if the residential water chiller continues to operate in defrost mode. The system can be controlled to exit defrost mode. The second preset pressure is greater than the first preset pressure and is generally set to a value not exceeding 0.5 MPa. The first time threshold is less than or equal to the second time threshold, meaning the second time threshold is generally less than 2 minutes.

[0108] The principle behind setting the above temperature, pressure, and duration thresholds is that when the outlet water temperature and refrigerant pressure of the water circulation system in a household water chiller are low, the water exchanging heat with the refrigerant in the water-side heat exchanger is more likely to freeze. Therefore, in order to ensure the smooth operation of the defrosting mode and prevent the water-side heat exchanger from freezing, the duration of this low temperature and low pressure state is relatively short. Conversely, the duration of the state with higher outlet water temperature and higher refrigerant pressure is relatively long.

[0109] In this way, the operating frequency of the compressor can be controlled according to the outlet water temperature and corresponding pressure of the water-side heat exchanger, preventing the water exchanging heat with the refrigerant in the water-side heat exchanger from freezing, effectively protecting the water-side heat exchanger, and thus extending the service life of the household water chiller.

[0110] In some implementations, please refer to Figure 10 Step 01 also includes:

[0111] 013: When the residential water chiller is started and the unit is about to switch from cooling mode to heating mode, obtain the ambient temperature and the outlet water temperature of the water circulation system that exchanges heat with the water-side heat exchanger.

[0112] Step 013 includes:

[0113] 0131: When the ambient temperature is greater than the second preset temperature and the return water temperature is greater than the third preset temperature, the compressor of the household water purifier is started after the third time threshold, and the four-way valve of the household water purifier is switched.

[0114] 0132: When the ambient temperature is less than or equal to the second preset temperature or the return water temperature is less than or equal to the third preset temperature, the compressor is started after the fourth time threshold is reached and the four-way valve is switched, wherein the fourth time threshold is less than or equal to the third time threshold.

[0115] In some embodiments, the processor is configured to, when the residential water heater is started and the unit including the water-side heat exchanger is about to switch from cooling mode to heating mode, acquire the ambient temperature and the outlet water temperature of the water circulation system that exchanges heat with the water-side heat exchanger; and, when the ambient temperature is greater than a second preset temperature and the return water temperature is greater than a third preset temperature, control the switching of the four-way valve of the residential water heater after starting the compressor for a third time threshold; and, when the ambient temperature is less than or equal to the second preset temperature or the return water temperature is less than or equal to the third preset temperature, control the switching of the four-way valve after starting the compressor for a fourth time threshold, wherein the fourth time threshold is less than or equal to the third time threshold.

[0116] Specifically, when the unit is about to switch from cooling mode to heating mode, the temperature of the water-side heat exchanger in the residential water chiller is low. Without special restrictions on refrigerant pressure, the water exchanging heat with the refrigerant in the water-side heat exchanger is prone to freezing, potentially causing damage. Therefore, the outlet water temperature of the water circulation system exchanging heat with the water-side heat exchanger can be obtained, and the four-way valve of the residential water chiller can be switched when the outlet water temperature reaches a certain value. The four-way valve is a control valve with four liquid channels; by switching the control valve, the flow direction of the refrigerant in the residential water chiller can be changed, thereby achieving the effect of switching between cooling and heating modes.

[0117] When the ambient temperature is higher than the second preset temperature and the return water temperature is higher than the third preset temperature, the compressor of the residential water heater can be started after a third time threshold, and the four-way valve of the residential water heater can be switched. If the four-way valve is not switched to switch from cooling mode to heating mode, the water exchanging heat with the refrigerant in the water-side heat exchanger may freeze. The second preset temperature is the ambient temperature value required for heating mode, and this value should not be too low. The third preset temperature is used to constrain the return water temperature threshold at which the cooling mode reaches stability before switching to heating mode. When the return water temperature is higher than the third preset temperature, it indicates that the current cooling mode has a greater effect on regulating the ambient temperature, and the four-way valve does not need to be switched for a short period after the compressor starts working. Therefore, the third time threshold can be set to a value of 5 seconds or more.

[0118] When the ambient temperature is less than or equal to the second preset temperature or the return water temperature is less than or equal to the third preset temperature, the compressor will start after a fourth time threshold, controlling the four-way valve to switch. If the four-way valve is not switched from cooling mode to heating mode, the water exchanging heat with the refrigerant in the water-side heat exchanger may freeze. The fourth time threshold, which is less than or equal to the third time threshold, can be set to a value of 5 seconds or more. Furthermore, to further prevent the water-side heat exchanger from freezing, the fourth time threshold should also have an upper limit, such as no more than 30 seconds.

[0119] The principle behind setting the above temperature, pressure, and duration thresholds is that when both the ambient temperature and the return water temperature in the water circulation system are relatively high, the cooling time can be appropriately extended. Conversely, when the ambient temperature or the return water temperature is relatively low, it indicates that the current cooling mode is not effective. At this time, the water in the water-side heat exchanger is more likely to freeze. Therefore, in order to prevent freezing, the continuous working time of the compressor needs to be limited in this state.

[0120] In this way, the switching of the four-way valve of the air conditioning unit can be controlled according to the ambient temperature of the water-side heat exchanger, the return water temperature, and the compressor working time, so as to change the working state of the household water system and prevent the water-side heat exchanger from freezing.

[0121] This application also provides a computer-readable storage medium storing a computer program that, when executed by one or more processors, implements the vehicle air conditioning control method as described in the above embodiments.

[0122] In the description of this specification, the terms "some embodiments," "furthermore," "it should be noted," etc., refer to specific features, structures, materials, or characteristics described in connection with embodiments or examples that are included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Furthermore, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0123] Any process or method description in the flowchart or otherwise herein can be understood as representing a module, segment, or portion of code comprising one or more executable instructions for implementing a particular logical function or process, and the scope of the preferred embodiments of this application includes additional implementations in which functions may be performed not in the order shown or discussed, including substantially simultaneously or in reverse order according to the functions involved, as should be understood by those skilled in the art to which embodiments of this application pertain.

[0124] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application.

Claims

1. A control method for a household water dispenser, characterized in that, include: The refrigerant pressure inside the water-side heat exchanger of the household water heater is obtained when the water-side heat exchanger is operating in cooling mode. When the refrigerant pressure is less than a first predetermined threshold, the unit containing the water-side heat exchanger is controlled to exit the cooling mode. The process of obtaining the refrigerant pressure within the water-side heat exchanger includes: Obtain the refrigerant pressure within the water-side heat exchanger that exchanges heat with the water circulation system; When the refrigerant pressure is greater than or equal to the first predetermined threshold and less than the second predetermined threshold, the minimum frequency limit of the compressor is reduced. When the refrigerant pressure is greater than or equal to the second predetermined threshold and less than the third predetermined threshold, the operating frequency of the compressor is reduced every predetermined time interval; When the refrigerant pressure is greater than or equal to the third predetermined threshold and less than the fourth predetermined threshold, the current operating frequency of the compressor is limited to the maximum operating frequency. When the refrigerant pressure is greater than the fourth predetermined threshold, the operating frequency of the compressor is adjusted according to actual needs; When the household water purifier is in defrost mode, the outlet water temperature of the water circulation system that exchanges heat with the water-side heat exchanger is obtained. The step of controlling the unit containing the water-side heat exchanger to exit the cooling mode when the refrigerant pressure is less than a first predetermined threshold includes: When the duration of the water outlet temperature being lower than the first preset temperature and the refrigerant pressure being lower than the first preset pressure reaches a first duration threshold, the household water heater is controlled to exit the defrosting mode. When the duration for which the outlet water temperature is greater than or equal to the first preset temperature and the pressure is less than the second preset pressure reaches a second duration threshold, the household water purifier is controlled to exit the defrost mode, wherein the second preset pressure is greater than the first preset pressure and the first duration threshold is less than or equal to the second duration threshold.

2. The control method according to claim 1, characterized in that, The step of controlling the unit containing the water-side heat exchanger to exit the cooling mode when the refrigerant pressure is less than a first predetermined threshold includes: Turn off the household water purifier.

3. The control method according to claim 1, characterized in that, The method of obtaining the refrigerant pressure within the water-side heat exchanger when the water-side heat exchanger of the residential water heater is operating in cooling mode includes: When the household water heater is started and the unit is about to switch from the cooling mode to the heating mode, the ambient temperature and the outlet water temperature of the water circulation system that exchanges heat with the water-side heat exchanger are obtained. The step of controlling the unit containing the water-side heat exchanger to exit the cooling mode when the refrigerant pressure is less than a first predetermined threshold includes: When the ambient temperature is greater than the second preset temperature and the return water temperature is greater than the third preset temperature, the compressor of the household water purifier is started after a third time threshold, and the four-way valve of the household water purifier is switched. When the ambient temperature is less than or equal to the second preset temperature or the return water temperature is less than or equal to the third preset temperature, the compressor is started after a fourth time threshold is set, and the four-way valve is controlled to switch, wherein the fourth time threshold is less than or equal to the third time threshold.

4. A household water dispenser, comprising a controller, the controller implementing the control method as described in any one of claims 1-3.

5. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program that, when executed by one or more processors, implements the control method as described in any one of claims 1-3.

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