Enthalpy increasing control method and device, heat pump unit and storage medium

Abstract

The invention provides an enthalpy increasing control method and device, a heat pump unit and a storage medium, relates to the technical field of heat pumps, and solves the problem that in the related technology, the heating performance of the heat pump unit is poor under the conditions of low environment temperature and low water temperature. Corresponding branches for enthalpy-increasing air supply and enthalpy-increasing flow are determined by controlling a three-way electromagnetic valve and an enthalpy-increasing electronic expansion valve, so that the unit can maintain sufficient superheat degree in the operation process, stable operation of the unit is ensured, and the temperature change of a refrigerant is continuously detected, so that the enthalpy-increasing air supply efficiency is improved. Therefore, the overall superheat degree can be increased under the condition of low environment temperature and low water temperature, the heating performance of a unit can be improved, the damage risk of a compressor is reduced, and then the reliability of the unit is improved.

Description

Technical Field

[0001] The present application relates to the field of heat pump technology, and in particular to an enthalpy increase control method, device, heat pump unit and storage medium. Background Art

[0002] As energy and environmental issues become increasingly prominent, green and efficient heating methods have attracted much attention. Heat pump jet enthalpy increase technology is an advanced thermal cycle technology that not only improves the performance of the compressor and the heating capacity of the unit, but also expands the operating range of the heat pump system under different ambient temperatures.

[0003] However, related technologies

[0004] Usually, an electronic expansion valve that increases enthalpy and acts as an auxiliary circuit is added to the heat pump unit, and it is controlled to achieve the jet enthalpy increase effect. However, in actual applications, the inventors found that the electronic expansion valve that increases enthalpy is usually not opened when the heat pump unit is started under low ambient temperature and low water temperature conditions, which results in the exhaust temperature being low and the low-pressure side return air being unable to maintain sufficient superheat. Moreover, if the electronic expansion valve that increases enthalpy is directly opened at this time to achieve the jet enthalpy increase effect, part of the medium-temperature and medium-pressure gas will participate in the compression process of the compressor, which will cause damage to the compressor. In this regard, the jet enthalpy increase control logic in the related art is insufficient, resulting in poor heating performance of the heat pump unit under low ambient temperature and low water temperature conditions. Summary of the invention

[0005] The present application provides an enthalpy increase control method, device, heat pump unit and storage medium, which solves the problem of poor heating performance of the heat pump unit under low ambient temperature and low water temperature conditions in the related art. The present solution can add an enthalpy increase air supply passage in the heat pump system, and by controlling the enthalpy increase electronic expansion valve and the three-way solenoid valve, it can improve the overall superheat under low ambient temperature and low water temperature conditions, thereby improving the heating performance of the unit and improving the reliability of the unit.

[0006] In a first aspect, the present application provides an enthalpy increase control method, which is applied to a heat pump unit, wherein the heat pump unit includes a compressor, a plate heat exchanger, a four-way valve, an enthalpy increase electronic expansion valve, a first three-way valve and a three-way solenoid valve, wherein the exhaust port of the compressor is connected to the first inlet and outlet of the four-way valve, the first inlet and outlet of the enthalpy increase electronic expansion valve is used to access the return air main path to form a branch for enthalpy increase air replenishment, the second inlet and outlet of the enthalpy increase electronic expansion valve is connected to the first inlet and outlet of the plate heat exchanger, the second inlet and outlet of the plate heat exchanger are respectively connected to the enthalpy increase port of the compressor and one inlet and outlet of the first three-way valve through the three-way solenoid valve, and the remaining two inlets and outlets of the first three-way valve are respectively connected to the return air port of the compressor and the second inlet and outlet of the four-way valve;

[0007] The enthalpy increase control method comprises:

[0008] Detecting the water inlet temperature of the heat pump unit, and controlling the valve state of the three-way solenoid valve based on the water inlet temperature to conduct the first enthalpy increase loop connected to the return air port of the compressor or conduct the second enthalpy increase loop connected to the first three-way valve;

[0009] Based on the currently acquired condensing superheat, determine whether to open the enthalpy-increasing electronic expansion valve;

[0010] When it is determined that the enthalpy-increasing electronic expansion valve is to be opened, the enthalpy-increasing electronic expansion valve is controlled to be opened at an initial opening degree;

[0011] In response to the opening of the enthalpy-increasing electronic expansion valve, the latest condensing superheat and economizer superheat are obtained in real time;

[0012] The opening of the enthalpy-increasing electronic expansion valve is adjusted according to the condensing superheat and the economizer superheat.

[0013] In a second aspect, the present application further provides an enthalpy increase control device, which is applied to the heat pump unit provided in the first aspect, and the enthalpy increase control device includes:

[0014] A three-way control module is configured to detect the inlet water temperature of the heat pump unit and control the valve state of the three-way solenoid valve based on the inlet water temperature to conduct the first enthalpy increase loop connected to the return air port of the compressor or conduct the second enthalpy increase loop connected to the first three-way valve;

[0015] an opening and closing judgment module, configured to determine whether to open the enthalpy-increasing electronic expansion valve based on the currently acquired condensing superheat;

[0016] The valve control module is configured to control the enthalpy-increasing electronic expansion valve to open at an initial opening degree when it is determined that the enthalpy-increasing electronic expansion valve is opened;

[0017] A superheat detection module is configured to obtain the latest condensing superheat and economizer superheat in real time in response to the opening of the enthalpy-increasing electronic expansion valve;

[0018] The opening adjustment module is configured to adjust the opening of the enthalpy-increasing electronic expansion valve according to the condensing superheat and the economizer superheat.

[0019] In a third aspect, the present application further provides a heat pump unit, the heat pump unit comprising:

[0020] one or more processors;

[0021] a storage device for storing one or more programs,

[0022] When one or more programs are executed by one or more processors, the one or more processors implement the enthalpy increase control method of the present application.

[0023] In a fourth aspect, the present application also provides a storage medium storing computer executable instructions, which are used to execute the enthalpy increase control method of the present application when executed by a processor.

[0024] The present application divides the enthalpy-increasing air supply circuit into two branches by adding a three-way solenoid valve and a first three-way pipe, and then determines the corresponding branch for enthalpy-increasing air supply and the enthalpy-increasing flow rate by controlling the three-way solenoid valve and the enthalpy-increasing electronic expansion valve, so that the unit can maintain sufficient superheat during operation, thereby ensuring the stable operation of the unit, and by continuously detecting the temperature change of the refrigerant to gradually adjust the flow rate required for the enthalpy-increasing air supply, so as to improve the overall superheat under low ambient temperature and low water temperature conditions, which helps to improve the heating performance of the unit and reduce the risk of compressor damage, thereby improving the reliability of the unit. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 A schematic diagram of the system structure of a heat pump unit provided in one embodiment of the present application;

[0026] Figure 2 A schematic diagram of the steps of the enthalpy increase control method provided in one embodiment of the present application;

[0027] Figure 3 A schematic diagram of the steps for adjusting the opening of an enthalpy-increasing electronic expansion valve provided in an embodiment of the present application;

[0028] Figure 4 A schematic diagram of the structure of an enthalpy increase control device provided in one embodiment of the present application;

[0029] Figure 5 A schematic diagram of the structure of a heat pump unit provided in one embodiment of the present application. DETAILED DESCRIPTION

[0030] The embodiments of the present application are further described in detail below in conjunction with the accompanying drawings and examples. It is to be understood that the specific embodiments described herein are only used to explain the embodiments of the present application, rather than to limit the embodiments of the present application. It should also be noted that, for ease of description, only the parts related to the embodiments of the present application rather than all structures are shown in the accompanying drawings, and those skilled in the art should be able to think of it after reading the specification of this application that as long as the technical features do not contradict each other, any combination of the technical features can constitute an optional implementation method.

[0031] The terms "first", "second", etc. in the specification and claims of the present application are used to distinguish similar objects, and are not used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable when appropriate, so that the embodiments of the present application can be implemented in an order other than those illustrated or described here, and the objects distinguished by "first", "second", etc. are generally a class, and the number of objects is not limited. For example, the first object can be one or more. In addition, "and / or" in the specification and claims represents at least one of the connected objects, and the character " / " generally represents that the objects associated before and after are in an "or" relationship. In the description of the present application, "multiple" means two or more, and "several" means one or more.

[0032] Air source heat pump is a system that uses low-quality heat in the air for energy conversion. Its working principle is to absorb low-temperature heat from the outside air through the evaporator, increase the temperature through the compressor, and then release it to the space that needs heating. As energy and environmental issues become increasingly prominent, green and efficient heating methods have attracted much attention. Among many heating technologies, air source heat pump has become one of the popular choices due to its energy-saving, environmental protection and stable operation. As a key link in air source heat pump, jet enthalpy increase technology is making an important contribution to its efficiency improvement and performance optimization.

[0033] The jet enthalpy technology adds a jet circuit to the traditional heat pump system, that is, adds an enthalpy-increasing electronic expansion valve that acts as an auxiliary circuit to achieve secondary compression of the refrigerant, thereby improving the energy efficiency and heating capacity of the system. However, in actual applications, the inventors found that the enthalpy-increasing electronic expansion valve is usually not opened when the heat pump unit is started under low ambient temperature and low water temperature conditions, which results in low exhaust temperature and inability to maintain sufficient superheat of the return air on the low-pressure side. Moreover, if the enthalpy-increasing electronic expansion valve is directly opened at this time to achieve the jet enthalpy-increasing effect, some medium-temperature and medium-pressure gas will participate in the compression process of the compressor, which will cause damage to the compressor.

[0034] In this regard, in order to solve the problem that the jet enthalpy increase control logic in the related art is insufficient, resulting in poor heating performance of the heat pump unit under low ambient temperature and low water temperature conditions. The present application provides an enthalpy increase control method, which is applied to a heat pump unit, the heat pump unit comprising a compressor 101, a plate heat exchanger 102, a four-way valve 103, an enthalpy increase electronic expansion valve 201, a first three-way valve 202 and a three-way electromagnetic valve 203. In addition, the heat pump unit also includes a fin heat exchanger 104 and a shell and tube heat exchanger 105 as an evaporator and a condenser in the system, as well as a filter 204, a main electronic expansion valve 205 and a second three-way valve 206.

[0035] For example, Figure 1A schematic diagram of the system structure of a heat pump unit provided in an embodiment of the present application, as shown in the figure, the exhaust port of the compressor 101 is connected to the first inlet and outlet of the four-way valve 103, the first inlet and outlet of the enthalpy-increasing electronic expansion valve 201 is used to connect to the return air main path to form a branch for enthalpy-increasing air replenishment, the second inlet and outlet of the enthalpy-increasing electronic expansion valve 201 is connected to the first inlet and outlet of the plate heat exchanger 102, the second inlet and outlet of the plate heat exchanger 102 are respectively connected to the enthalpy-increasing port of the compressor 101 and an inlet and outlet of the first three-way valve 202 through the three-way solenoid valve 203, and the remaining two inlets and outlets of the first three-way valve 202 are respectively connected to the return air port of the compressor 101 to form a branch for enthalpy-increasing air replenishment. And the second inlet and outlet of the four-way valve 103, the third inlet and outlet of the four-way valve 103 is connected to the first connection port of the finned heat exchanger 104, the second connection port of the finned heat exchanger 104 is connected to the first inlet and outlet of the main electronic expansion valve 205 through the filter 204, the main electronic expansion valve 205 is respectively connected to the third inlet and outlet of the plate heat exchanger 102 and the first inlet and outlet of the enthalpy increasing electronic expansion valve 201 through the second three-way valve 206, the fourth inlet and outlet of the plate heat exchanger 102 is connected to the air inlet and liquid inlet of the shell and tube heat exchanger 105, and the air outlet of the shell and tube heat exchanger 105 is connected to the fourth inlet and outlet of the four-way valve 103.

[0036] It can be seen that the circulation path in the heat pump unit passes through the compressor 101, the four-way valve 103, the finned heat exchanger 104, the main electronic expansion valve 205, the plate heat exchanger 102, the shell and tube heat exchanger 105 in sequence, and finally returns to the compressor 101 through the four-way valve 103. When the auxiliary path of jet enthalpy increase is turned on, the enthalpy increase electronic expansion valve 201 is opened, and based on the above path, after the refrigerant passes through the main electronic expansion valve 205, the corresponding path can also be the enthalpy increase electronic expansion valve 201, the plate heat exchanger 102, and the compressor 101, and due to the setting of the three-way solenoid valve 203, the refrigerant can enter the compressor 101 from the return air port or the enthalpy increase port of the compressor 101.

[0037] Based on this, it can be imagined that the heat pump unit also includes corresponding electronic equipment, such as an industrial computer, a mainboard controller, etc., to execute the enthalpy increase control method of the present application. Figure 2 A schematic diagram of the steps of the enthalpy increase control method provided in one embodiment of the present application is provided, wherein the enthalpy increase control is achieved by controlling the three-way solenoid valve and the enthalpy increase electronic expansion valve in the heat pump unit, and the specific steps include steps S110-S150.

[0038] Step S110, detecting the inlet water temperature of the heat pump unit, and controlling the valve state of the three-way solenoid valve based on the inlet water temperature to connect the first enthalpy increase circuit connected to the return air port of the compressor or connect the second enthalpy increase circuit connected to the first three-way valve.

[0039] It is conceivable that the water inlet temperature of the heat pump unit can be detected by a corresponding temperature sensor. Then, the valve state of the three-way solenoid valve is controlled by the detected water inlet temperature to conduct the first enthalpy increase circuit connected to the return air port of the compressor or conduct the second enthalpy increase circuit connected to the first three-way valve. Among them, the first enthalpy increase circuit corresponds to the path from the plate heat exchanger through the three-way solenoid valve to the return air port of the compressor, and the second enthalpy increase circuit corresponds to the path from the plate heat exchanger through the three-way solenoid valve and then into the enthalpy increase port of the compressor.

[0040] In addition, the three-way solenoid valve is a one-inlet and two-outlet three-way valve. The solenoid valve coil on it is powered on or off, which corresponds to different valve states, so that different interfaces on the three-way solenoid valve, such as the three-way solenoid valve has interface 1, interface 2 and interface 3. When the solenoid valve coil is powered off, interface 2 is closed and interface 1 is connected to interface 3; when the solenoid valve coil is powered on, interface 3 is closed and interface 1 is connected to interface 2.

[0041] The control of the valve state of the three-way solenoid valve is based on the inlet water temperature. For example, in one embodiment, a preset water temperature threshold is set, and the preset water temperature threshold can be set according to the actual use scenario. For example, it can be set to a threshold of 20°C for the north. When the inlet water temperature is less than the preset water temperature threshold, the three-way solenoid valve is controlled to be connected to the first three-way valve to connect the first enthalpy increase loop; and when the inlet water temperature is greater than or equal to the preset water temperature threshold, the three-way solenoid valve is controlled to be connected to the enthalpy increase port of the compressor to connect the second enthalpy increase loop.

[0042] It should be noted that the control of the valve state of the three-way solenoid valve is performed in real time. If the inlet water temperature meets any one of the above two conditions, the three-way solenoid valve is switched to the corresponding valve state.

[0043] Therefore, by controlling the three-way solenoid valve, it is possible to switch to the corresponding enthalpy increase circuit when the inlet water temperature meets the corresponding conditions, so as to increase the superheat and thus improve the heating performance of the unit.

[0044] Step S120: Determine whether to open the enthalpy-increasing electronic expansion valve based on the currently acquired condensation superheat.

[0045] As for the enthalpy-increasing electronic expansion valve, it is determined based on the detection of the condensation superheat. It can be understood that the condensation superheat is the difference between the exhaust temperature and the condensation temperature, wherein the condensation temperature is the temperature at which the refrigerant condenses from gas to liquid. When the pressure and the medium of the refrigerant are determined, the condensation temperature can also be determined. For this, the current condensation superheat can be determined by detecting the exhaust temperature through the corresponding temperature sensor. Similarly, in some embodiments, a first preset superheat is also provided, and the first preset superheat is a threshold value associated with the condensation superheat. When the condensation superheat is greater than or equal to the first preset superheat, it is determined to open the enthalpy-increasing electronic expansion valve; when the condensation superheat is less than the first preset superheat, it is determined to close the enthalpy-increasing electronic expansion valve. Therefore, by judging whether to open the jet enthalpy-increasing based on the condensation superheat, this solution can even open the auxiliary circuit in the system to introduce the refrigerant into the compressor, thereby improving the heating performance of the unit.

[0046] Step S130: When it is determined that the enthalpy-increasing electronic expansion valve is to be opened, the enthalpy-increasing electronic expansion valve is controlled to be opened at an initial opening degree.

[0047] When the condensation superheat meets the corresponding conditions, it is determined that the enthalpy-increasing electronic expansion valve needs to be opened. Accordingly, the enthalpy-increasing electronic expansion valve is opened according to the set initial opening control, that is, the enthalpy-increasing electronic expansion valve is opened with the initial opening. It should be noted that in some implementations, the initial opening is determined according to the temperature range of the outlet water temperature of the heat pump unit, and different temperature ranges correspond to different opening values, and the larger the temperature mean of the temperature range, the larger the corresponding opening value. Exemplarily, as the outlet water temperature increases or decreases, the outlet water temperature will be located in the corresponding temperature range. For example, in a temperature range, the value range of the temperature range is (0, 25], and the corresponding outlet opening is 50, while in another temperature range, the value range of the temperature range is (25, 35], and the corresponding outlet opening is 70. Therefore, this scheme can maintain sufficient superheat more quickly by setting the corresponding initial opening according to the different outlet water temperatures, so as to improve the heating performance of the unit.

[0048] Step S140: in response to the opening of the enthalpy-increasing electronic expansion valve, the latest condensing superheat and economizer superheat are obtained in real time.

[0049] When the enthalpy-increasing electronic expansion valve is turned on, the condensing superheat and economizer superheat need to be updated in real time, such as by detecting the corresponding temperature in real time to obtain the latest condensing superheat and economizer superheat. It can be imagined that the economizer superheat is the inlet and outlet temperature difference of the corresponding plate heat exchanger. The economizer superheat can be determined by detecting the refrigerant temperature in the pipeline connecting the enthalpy-increasing electronic expansion valve to the plate heat exchanger and the refrigerant temperature in the pipeline connecting the three-way solenoid valve to the plate heat exchanger through the sensor, that is, the economizer superheat is the difference between the inlet temperature at the first inlet and outlet of the corresponding plate heat exchanger and the outlet temperature at the second inlet and outlet of the corresponding plate heat exchanger. The condensing superheat is the exhaust temperature and the condensing temperature. The corresponding condensing superheat can be determined by detecting the exhaust temperature.

[0050] Step S150: adjusting the opening of the enthalpy-increasing electronic expansion valve according to the condensing superheat and the economizer superheat.

[0051] After determining the latest condensing superheat and economizer superheat, the opening of the enthalpy-increasing electronic expansion valve is adjusted according to the condensing superheat and the economizer superheat. It is conceivable that when the condensing superheat and the economizer superheat are updated again, the opening of the enthalpy-increasing electronic expansion valve is adjusted accordingly. The specific adjusted opening value needs to be determined according to the change of the condensing superheat and the economizer superheat. For example, in one embodiment, when it is determined that the condensing superheat is in a preset superheat range, the opening of the enthalpy-increasing electronic expansion valve is increased or decreased based on the change of the economizer superheat.

[0052] It can be seen from the above scheme that this scheme divides the enthalpy-increasing air supply circuit into two branches by adding a three-way solenoid valve and a first three-way pipe, and then determines the corresponding branch for enthalpy-increasing air supply and the enthalpy-increasing flow rate by controlling the three-way solenoid valve and the enthalpy-increasing electronic expansion valve, so that the unit can maintain sufficient superheat during operation, thereby ensuring the stable operation of the unit, and by continuously detecting the temperature change of the refrigerant to gradually adjust the flow rate required for the enthalpy-increasing air supply, so as to improve the overall superheat under low ambient temperature and low water temperature conditions, which helps to improve the heating performance of the unit and reduce the risk of compressor damage, thereby improving the reliability of the unit.

[0053] In some embodiments, after the condensing superheat and the economizer superheat are determined, a corresponding adjustment strategy may be determined based on the latest condensing superheat and the economizer superheat to adjust the opening of the enthalpy-increasing electronic expansion valve. Figure 3 A schematic diagram of the steps for adjusting the opening of the enthalpy-increasing electronic expansion valve provided in an embodiment of the present application, wherein a first preset superheat and a second preset superheat are provided for the condensing superheat, wherein the first preset superheat is less than the second preset superheat, and three superheat intervals are divided by the first preset superheat and the second preset superheat, and corresponding adjustment strategies are respectively provided. The specific steps are as follows:

[0054] Step S210: when the latest condensation superheat is less than the first preset superheat, reduce the opening of the enthalpy-increasing electronic expansion valve, and close the enthalpy-increasing electronic expansion valve when the opening of the enthalpy-increasing electronic expansion valve reaches the minimum valve opening.

[0055] Step S220: When the latest condensing superheat is greater than or equal to the first preset superheat and less than or equal to the second preset superheat, adjust the opening of the enthalpy-increasing electronic expansion valve according to the difference between the economizer superheat and the target superheat.

[0056] Step S230: when the latest condensation superheat is greater than the second preset superheat, increase the opening of the enthalpy-increasing electronic expansion valve, and maintain the opening of the enthalpy-increasing electronic expansion valve when the opening of the enthalpy-increasing electronic expansion valve reaches the maximum valve opening.

[0057] It is understandable that after determining that the condensation superheat is less than the first preset superheat, the opening of the enthalpy-increasing electronic expansion valve is reduced, for example, the opening of the enthalpy-increasing electronic expansion valve is reduced according to a preset step. It is conceivable that when the updated condensation superheat is still less than the first preset superheat, the opening of the enthalpy-increasing electronic expansion valve continues to be reduced until the opening of the enthalpy-increasing electronic expansion valve reaches the minimum valve opening, that is, the opening is 0, and then the enthalpy-increasing electronic expansion valve is closed. It should be noted that in some embodiments, the opening of the enthalpy-increasing electronic expansion valve can also be reduced by progressively increasing the adjustment step, for example, the first adjustment is 5 steps as the step, and the next adjustment is 6 steps as the step, so as to reduce the flow faster to avoid damage to the compressor.

[0058] After determining that the condensing superheat is greater than or equal to the first preset superheat and less than or equal to the second preset superheat, the opening of the enthalpy-increasing electronic expansion valve is adjusted according to the difference between the economizer superheat and the target superheat. That is, by adjusting the opening of the enthalpy-increasing electronic expansion valve, the economizer superheat can be maintained at the target superheat. Among them, as the opening of the enthalpy-increasing electronic expansion valve changes, the inlet and outlet temperature difference of the plate heat exchanger will also change accordingly, that is, the economizer superheat will change with the opening of the enthalpy-increasing electronic expansion valve.

[0059] In addition, after determining that the condensation superheat is greater than the second preset superheat, the enthalpy-increasing electronic expansion valve is increased, for example, the opening of the enthalpy-increasing electronic expansion valve is increased according to a preset step. It can be imagined that when the updated condensation superheat is still greater than the second preset superheat, the opening of the enthalpy-increasing electronic expansion valve is continued to be increased until the opening of the enthalpy-increasing electronic expansion valve reaches the maximum valve opening, thereby maintaining the maximum valve opening of the enthalpy-increasing electronic expansion valve. Of course, similarly, the opening of the enthalpy-increasing electronic expansion valve can also be increased by progressively increasing the adjustment step.

[0060] Therefore, each time a new exhaust temperature is detected, the corresponding condensing superheat is updated to determine the adjustment strategy to be adopted, and then the enthalpy increase electronic expansion valve is adjusted accordingly in time to enable the unit to operate stably, and the flow rate of the enthalpy increase air supply is adjusted in time to improve the heating performance of the unit.

[0061] In one embodiment, when the condensing superheat is greater than or equal to the first preset superheat and less than or equal to the second preset superheat, the opening control of the enthalpy-increasing electronic expansion valve is determined according to the economizer superheat. To this end, the inlet temperature at the second inlet and outlet of the plate heat exchanger and the outlet temperature at the third inlet and outlet of the plate heat exchanger are detected in real time, so as to calculate the difference between the inlet temperature and the outlet temperature, and then update the economizer superheat.

[0062] In addition, a target superheat is set. By adjusting the opening of the enthalpy-increasing electronic expansion valve, the corresponding inlet temperature and outlet temperature of the plate heat exchanger will change, so that the superheat of the economizer changes. Therefore, when the latest economizer superheat is greater than the target superheat, the opening of the enthalpy-increasing electronic expansion valve is reduced; when the latest economizer superheat is less than the target superheat, the opening of the enthalpy-increasing electronic expansion valve is increased; when the latest economizer superheat is equal to the target superheat, the enthalpy-increasing electronic expansion valve is controlled to maintain the current opening. In turn, the economizer superheat is maintained at the target superheat to maintain the superheat.

[0063] For example, the target superheat is 0, that is, the inlet temperature and outlet temperature of the plate heat exchanger need to be maintained consistent. When the difference between the two is greater than 0, that is, the superheat of the economizer is greater than the target superheat, the opening of the enthalpy-increasing electronic expansion valve is reduced so that the inlet temperature and the outlet temperature are gradually maintained consistent.

[0064] Therefore, this solution continuously detects the changing temperature of the refrigerant in the system and then adjusts the flow rate of the enthalpy-enhancing air supply, which can enable the unit to perform at its best while achieving enthalpy-enhancing air supply, thereby helping to improve the reliability of the unit.

[0065] It should be noted that, in some embodiments, when the condensing superheat is greater than or equal to the first preset superheat and less than or equal to the second preset superheat, the opening control of the enthalpy increase electronic expansion valve is PID adjusted according to the target superheat so that the economizer superheat is maintained at the target superheat.

[0066] In some embodiments, the initial opening of the enthalpy-increasing electronic expansion valve can also be adjusted according to the exhaust temperature. For example, when the exhaust temperature is greater than the preset temperature, the opening of the enthalpy-increasing electronic expansion valve is adjusted to a target opening, which is the sum of the preset opening value and the initial opening of the enthalpy-increasing electronic expansion valve. That is, on the basis of the original initial opening, the preset opening value is increased so that the enthalpy-increasing electronic expansion valve can be opened with a larger initial opening, thereby reducing the exhaust temperature and maintaining the stable operation of the unit.

[0067] Figure 4 This is a schematic diagram of the structure of an enthalpy increase control device provided in an embodiment of the present application. The device is applied to the above-mentioned heat pump unit, and is used to execute the enthalpy increase control method provided in the above-mentioned embodiment, and has functional modules and beneficial effects corresponding to the execution method. As shown in the figure, the enthalpy increase control device includes a three-way control module 401, an opening and closing judgment module 402, a valve control module 403, a superheat detection module 404 and an opening adjustment module 405.

[0068] The three-way control module 401 is configured to detect the water inlet temperature of the heat pump unit and control the valve state of the three-way solenoid valve based on the water inlet temperature to conduct the first enthalpy increase circuit connected to the return air port of the compressor or conduct the second enthalpy increase circuit connected to the first three-way valve;

[0069] The opening and closing judgment module 402 is configured to determine whether to open the enthalpy-increasing electronic expansion valve based on the currently acquired condensation superheat;

[0070] The valve control module 403 is configured to control the enthalpy-increasing electronic expansion valve to be opened at an initial opening degree when it is determined to open the enthalpy-increasing electronic expansion valve;

[0071] The superheat detection module 404 is configured to obtain the latest condensing superheat and economizer superheat in real time in response to the opening of the enthalpy-increasing electronic expansion valve;

[0072] The opening adjustment module 405 is configured to adjust the opening of the enthalpy-increasing electronic expansion valve according to the condensing superheat and the economizer superheat.

[0073] Based on the above embodiment, the three-way control module 401 is specifically configured as follows:

[0074] When the inlet water temperature is lower than the preset water temperature threshold, the three-way solenoid valve is controlled to be connected with the first three-way valve to connect the first enthalpy increase circuit;

[0075] When the inlet water temperature is greater than or equal to the preset water temperature threshold, the three-way solenoid valve is controlled to be connected to the enthalpy increase port of the compressor to open the second enthalpy increase loop.

[0076] Based on the above embodiment, the opening and closing judgment module 402 is specifically configured as follows:

[0077] When the condensation superheat is greater than or equal to the first preset superheat, determining to open the enthalpy-increasing electronic expansion valve;

[0078] When the condensation superheat is less than the first preset superheat, it is determined to close the enthalpy-increasing electronic expansion valve.

[0079] Based on the above embodiment, the opening adjustment module 405 is specifically configured as follows:

[0080] When the latest condensation superheat is less than the first preset superheat, the opening of the enthalpy-increasing electronic expansion valve is reduced, and the enthalpy-increasing electronic expansion valve is closed when the opening of the enthalpy-increasing electronic expansion valve reaches the minimum valve opening;

[0081] When the latest condensing superheat is greater than or equal to the first preset superheat and less than or equal to the second preset superheat, adjusting the opening of the enthalpy-increasing electronic expansion valve according to the difference between the economizer superheat and the target superheat;

[0082] When the latest condensation superheat is greater than the second preset superheat, the opening of the enthalpy-increasing electronic expansion valve is increased, and the opening of the enthalpy-increasing electronic expansion valve is maintained when the opening of the enthalpy-increasing electronic expansion valve reaches the maximum valve opening.

[0083] Based on the above embodiment, the economizer superheat is the difference between the inlet temperature at the first inlet and outlet of the corresponding plate heat exchanger and the outlet temperature at the second inlet and outlet of the corresponding plate heat exchanger, and the opening adjustment module 405 is further configured as follows:

[0084] Real-time detection of the inlet temperature at the second inlet and outlet of the plate heat exchanger and the outlet temperature at the third inlet and outlet of the plate heat exchanger, and updating the economizer superheat;

[0085] When the latest economizer superheat is greater than the target superheat, the opening of the enthalpy-increasing electronic expansion valve is reduced;

[0086] When the latest economizer superheat is less than the target superheat, the opening of the enthalpy-increasing electronic expansion valve is increased;

[0087] When the latest economizer superheat is equal to the target superheat, the enthalpy increase electronic expansion valve is controlled to maintain the current opening.

[0088] Based on the above embodiment, the initial opening is determined according to the temperature range of the outlet water temperature of the heat pump unit. Different temperature ranges correspond to different opening values, and the larger the temperature mean value of the temperature range, the larger the corresponding opening value.

[0089] On the basis of the above embodiment, the condensation superheat is the difference between the exhaust temperature of the compressor and the condensation temperature. The device further includes a valve opening module, and the valve opening module is configured as follows:

[0090] When the exhaust temperature is greater than the preset temperature, the opening of the enthalpy-increasing electronic expansion valve is adjusted to a target opening, and the target opening is the sum of the preset opening value and the initial opening of the enthalpy-increasing electronic expansion valve.

[0091] It is worth noting that in the embodiment of the above-mentioned device, the modules included are only divided according to functional logic, but are not limited to the above-mentioned division, as long as the corresponding functions can be achieved; in addition, the specific names of the modules are only for the convenience of distinguishing each other, and are not used to limit the protection scope of the embodiments of the present application.

[0092] Figure 5 The heat pump unit is a schematic diagram of the structure of an embodiment of the present application. The heat pump unit is used to execute the enthalpy increase control method provided in the above embodiment, and has the functional modules and beneficial effects corresponding to the execution method. The heat pump unit includes the compressor, plate heat exchanger, four-way valve, enthalpy increase electronic expansion valve, first three-way valve and three-way electromagnetic valve provided in the above embodiment, and its connection method refers to the above embodiment. As shown in the figure, the heat pump unit also includes a processor 501, a memory 502, an input device 503 and an output device 504. The number of processors 501 can be one or more, and one processor 501 is taken as an example in the figure; the processor 501, the memory 502, the input device 503 and the output device 504 can be connected by a bus or other means, and the figure takes the connection through a bus as an example. The memory 502, as a computer-readable storage medium, can be used to store software programs, computer executable programs and modules, such as program instructions / modules corresponding to the enthalpy increase control method in the embodiment of the present application. The processor 501 executes the software programs, instructions and modules stored in the memory 502 to perform various corresponding functional applications and data processing, that is, to implement the above-mentioned enthalpy increase control method.

[0093] The memory 502 may mainly include a program storage area and a data storage area, wherein the program storage area may store an operating system and at least one application required for a function; the data storage area may store data recorded or created during use, etc. In addition, the memory 502 may include a high-speed random access memory, and may also include a non-volatile memory, such as at least one disk storage device, a flash memory device, or other non-volatile solid-state storage device. In some embodiments, the memory 502 may further include a memory remotely arranged relative to the processor 501, and these remotely arranged memories may be connected via a network. Examples of the above-mentioned network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0094] The input device 503 can be used to input corresponding digital or character information to the processor 501, and to generate key signal input related to the user settings and function control of the device; the output device 504 can be used to send or display key signal output related to the user settings and function control of the device.

[0095] An embodiment of the present application also provides a storage medium storing computer executable instructions, which, when executed by a processor, are used to perform relevant operations in the enthalpy increase control method provided in any embodiment of the present application.

[0096] Computer-readable storage media include permanent and non-permanent, removable and non-removable media that can be implemented by any method or technology to store information. Information can be computer-readable instructions, data structures, program modules or other data. Examples of computer storage media include, but are not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technology, compact disk read-only memory (CD-ROM), digital versatile disk (DVD) or other optical storage, magnetic cassettes, magnetic disk storage or other magnetic storage devices or any other non-transmission media that can be used to store information that can be accessed by a computing device.

[0097] It should also be noted that the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, commodity or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, commodity or device. In the absence of more restrictions, the elements defined by the sentence "comprises a ..." do not exclude the existence of other identical elements in the process, method, commodity or device including the elements.

[0098] Note that the above are only preferred embodiments of the present application and the technical principles used. Those skilled in the art will understand that the present application is not limited to the specific embodiments described herein, and that various obvious changes, readjustments and substitutions can be made by those skilled in the art without departing from the scope of protection of the present application. Therefore, although the present application is described in more detail through the above embodiments, the present application is not limited to the above embodiments, and may include more other equivalent embodiments without departing from the concept of the present application, and the scope of the present application is determined by the scope of the appended claims.

Claims

1. A heat increase control method, characterized in that: Applied to a heat pump unit, the heat pump unit includes a compressor, a plate heat exchanger, a four-way valve, an enthalpy-increasing electronic expansion valve, a first three-way valve and a three-way solenoid valve, the exhaust port of the compressor is connected to the first inlet and outlet of the four-way valve, the first inlet and outlet of the enthalpy-increasing electronic expansion valve is used to access the return air main path to form an auxiliary path for enthalpy-increasing air replenishment, the second inlet and outlet of the enthalpy-increasing electronic expansion valve is connected to the first inlet and outlet of the plate heat exchanger, the second inlet and outlet of the plate heat exchanger are respectively connected to the enthalpy-increasing port of the compressor and one inlet and outlet of the first three-way valve through the three-way solenoid valve, and the remaining two inlets and outlets of the first three-way valve are respectively connected to the return air port of the compressor and the second inlet and outlet of the four-way valve; The enthalpy increase control method comprises: Detecting the water inlet temperature of the heat pump unit, and controlling the valve state of the three-way solenoid valve based on the water inlet temperature to connect the first enthalpy increase circuit connected to the return air port of the compressor or connect the second enthalpy increase circuit connected to the first three-way valve; Based on the currently acquired condensation superheat, determining whether to open the enthalpy-increasing electronic expansion valve; In the case where it is determined to open the enthalpy-increasing electronic expansion valve, controlling the enthalpy-increasing electronic expansion valve to open at an initial opening degree; In response to the opening of the enthalpy-increasing electronic expansion valve, the latest condensing superheat and economizer superheat are acquired in real time; The opening degree of the enthalpy-increasing electronic expansion valve is adjusted according to the condensing superheat and the economizer superheat.

2. The enthalpy increase control method according to claim 1, characterized in that: The detecting of the water inlet temperature of the heat pump unit and controlling the valve state of the three-way solenoid valve based on the water inlet temperature to connect the first enthalpy increasing circuit connected to the return air port of the compressor or the second enthalpy increasing circuit connected to the first three-way valve comprises: When the water inlet temperature is lower than a preset water temperature threshold, controlling the three-way solenoid valve to be connected to the first three-way valve to connect the first enthalpy increase circuit; When the water inlet temperature is greater than or equal to the preset water temperature threshold, the three-way solenoid valve is controlled to be connected to the enthalpy increase port of the compressor to connect the second enthalpy increase circuit.

3. The enthalpy increase control method according to claim 1, characterized in that: The determining whether to open the enthalpy-increasing electronic expansion valve based on the currently acquired condensation superheat comprises: When the condensation superheat is greater than or equal to a first preset superheat, determining to open the enthalpy-increasing electronic expansion valve; When the condensation superheat is less than the first preset superheat, it is determined to close the enthalpy-increasing electronic expansion valve.

4. The enthalpy increase control method according to claim 1, characterized in that: The step of adjusting the opening of the enthalpy-increasing electronic expansion valve according to the condensing superheat and the economizer superheat comprises: When the latest condensation superheat is less than the first preset superheat, reducing the opening of the enthalpy-increasing electronic expansion valve, and closing the enthalpy-increasing electronic expansion valve when the opening of the enthalpy-increasing electronic expansion valve reaches the minimum valve opening; When the latest condensing superheat is greater than or equal to the first preset superheat and less than or equal to the second preset superheat, adjusting the opening of the enthalpy-increasing electronic expansion valve according to the difference between the economizer superheat and the target superheat; When the latest condensation superheat is greater than the second preset superheat, the opening of the enthalpy-increasing electronic expansion valve is increased, and the opening of the enthalpy-increasing electronic expansion valve is maintained when the opening of the enthalpy-increasing electronic expansion valve reaches the maximum valve opening.

5. The enthalpy increase control method according to claim 4, characterized in that: The economizer superheat is the difference between the inlet temperature at the first inlet and outlet of the plate heat exchanger and the outlet temperature at the second inlet and outlet of the plate heat exchanger; When the condensing superheat is greater than or equal to the first preset superheat and less than or equal to the second preset superheat, adjusting the opening of the enthalpy-increasing electronic expansion valve according to the difference between the economizer superheat and the target superheat, comprises: Real-time detection of the inlet temperature at the second inlet and outlet of the plate heat exchanger and the outlet temperature at the third inlet and outlet of the plate heat exchanger, and updating the economizer superheat; When the latest economizer superheat is greater than the target superheat, reducing the opening of the enthalpy-increasing electronic expansion valve; When the latest economizer superheat is less than the target superheat, increasing the opening of the enthalpy-increasing electronic expansion valve; When the latest economizer superheat is equal to the target superheat, the enthalpy-increasing electronic expansion valve is controlled to maintain a current opening.

6. The enthalpy increase control method according to claim 1, characterized in that: The initial opening is determined according to the temperature range of the outlet water temperature of the heat pump unit. Different temperature ranges correspond to different opening values, and the larger the temperature mean value of the temperature range, the larger the corresponding opening value.

7. The enthalpy increase control method according to any one of claims 1 to 6, characterized in that: The condensation superheat is the difference between the exhaust temperature of the compressor and the condensation temperature. The method further includes: When the exhaust gas temperature is greater than a preset temperature, the opening of the enthalpy-increasing electronic expansion valve is adjusted to a target opening, and the target opening is the sum of a preset opening value and an initial opening of the enthalpy-increasing electronic expansion valve.

8. An enthalpy increase control device, characterized in that: Applied to a heat pump unit, the heat pump unit includes a compressor, a plate heat exchanger, a four-way valve, an enthalpy-increasing electronic expansion valve, a first three-way valve and a three-way solenoid valve, the exhaust port of the compressor is connected to the first inlet and outlet of the four-way valve, the first inlet and outlet of the enthalpy-increasing electronic expansion valve is used to access the return air main path to form a branch for enthalpy-increasing air replenishment, the second inlet and outlet of the enthalpy-increasing electronic expansion valve is connected to the first inlet and outlet of the plate heat exchanger, the second inlet and outlet of the plate heat exchanger are respectively connected to the enthalpy-increasing port of the compressor and one inlet and outlet of the first three-way valve through the three-way solenoid valve, and the remaining two inlets and outlets of the first three-way valve are respectively connected to the return air port of the compressor and the second inlet and outlet of the four-way valve; The enthalpy increase control device comprises: A three-way control module is configured to detect the water inlet temperature of the heat pump unit and control the valve state of the three-way solenoid valve based on the water inlet temperature to conduct the first enthalpy increase circuit connected to the return air port of the compressor or conduct the second enthalpy increase circuit connected to the first three-way valve; an opening and closing judgment module, configured to determine whether to open the enthalpy-increasing electronic expansion valve based on the currently acquired condensation superheat; a valve control module, configured to control the enthalpy-increasing electronic expansion valve to open at an initial opening degree when it is determined that the enthalpy-increasing electronic expansion valve is to be opened; a superheat detection module configured to obtain the latest condensing superheat and economizer superheat in real time in response to the opening of the enthalpy-increasing electronic expansion valve; The opening adjustment module is configured to adjust the opening of the enthalpy-increasing electronic expansion valve according to the condensing superheat and the economizer superheat.

9. A heat pump unit, characterized in that: The heat pump unit comprises: one or more processors; A storage device for storing one or more programs, when the one or more programs are executed by the one or more processors, the one or more processors implement the enthalpy increase control method as described in any one of claims 1-7.

10. A storage medium storing computer executable instructions, characterized in that: When the computer executable instructions are executed by a processor, they are used to perform the enthalpy increase control method according to any one of claims 1 to 7.

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