Air conditioning system

Abstract

The application provides an air conditioning system, comprising: a heat dissipation module, comprising: a heat dissipation branch, a first end of which is fluidly connected to a refrigerant-air heat exchanger; the refrigerant-air heat exchanger comprises: a heat exchanger main body and a reheat loop arranged below the heat exchanger main body, a first end of the reheat loop being fluidly connected to a refrigerant-water heat exchanger; a first end of a first valve element is fluidly connected to the refrigerant-water heat exchanger, a second end of the first valve element is fluidly connected to a second end of the reheat loop in one way and fluidly connected to a second end of the heat dissipation branch in another way; a second valve element is arranged between the first end of the reheat loop and the refrigerant-water heat exchanger; a control module is configured to take the sum of a preset total opening degree or a preset adjustment opening degree as a reference value, dynamically allocate opening degree weight coefficients of the first and second valve elements, and cooperatively adjust the first and second valve elements, so that the refrigerant flow passing through the first and second valve elements is redistributed, and the application can simultaneously inhibit frost formation of the refrigerant-air heat exchanger and / or condensation of the heat dissipation branch.

Description

Technical Field

[0001] This invention relates to the field of refrigeration system technology, and more particularly to an air conditioning system. Background Technology

[0002] At high ambient temperatures, the heat generated by the electronic control components of an air conditioning system can easily accumulate, leading to overheating. Currently, the main heat dissipation methods for outdoor unit electronic control systems in the market are forced air cooling and refrigerant cooling. Forced air cooling is limited by ambient air temperature and its heat dissipation effect is poor at high ambient temperatures. The mainstream technology tends to use refrigerant cooling, which can greatly enhance heat dissipation capacity at high ambient temperatures. However, if the refrigerant temperature is too low, condensation may occur in the refrigerant cooling device flowing through the electrical box, thus affecting the reliability of the electronic control system. For air conditioning systems with hot water production functions, a typical problem is that under conditions of high ambient temperature and low inlet water temperature, refrigerant condensation is very likely to occur when producing domestic hot water or drying floors.

[0003] Furthermore, at lower ambient temperatures, the outdoor heat exchanger acts as an evaporator during heating operation. Defrost water tends to accumulate at the bottom of the heat exchanger, leading to ice buildup at the bottom and even on the chassis under harsh conditions. This causes the outdoor heat exchanger's capacity to continuously deteriorate, eventually triggering an alarm and shutdown. Conventional solutions shorten the defrost cycle and prolong the defrost time, thus affecting actual heating capacity and user experience, and do not solve the bottom icing problem.

[0004] The information disclosed in this background section is only intended to enhance the understanding of the background technology of this application, and therefore may include prior art that is not known to those skilled in the art. Summary of the Invention

[0005] To address the two issues mentioned above, this application designs and provides an air conditioning system, comprising: a refrigerant-air heat exchanger for heat exchange between refrigerant and air; a refrigerant-water heat exchanger for heat exchange between refrigerant and water; and a heat dissipation module that uses refrigerant to dissipate heat from an electrical box. The module includes: a heat dissipation branch, the first end of which is fluidly connected to the refrigerant-air heat exchanger, and a first throttling element disposed between the first end of the heat dissipation branch and the refrigerant-air heat exchanger; the refrigerant-air heat exchanger includes: a heat exchanger body; a reheat exchange circuit disposed below the heat exchanger body, the first end of which is fluidly connected to the refrigerant-water heat exchanger; and a first valve element. The first end of the first valve element is fluidly connected to the refrigerant-water heat exchanger, and the second end of the first valve element is fluidly connected to the second end of the reheat exchange circuit and the second end of the heat dissipation branch. A second valve element is disposed between the first end of the reheat exchange circuit and the refrigerant-water heat exchanger. A control module is configured to dynamically allocate the opening weight coefficient of the first valve element and the opening weight coefficient of the second valve element, using a reference preset total opening degree or the sum of the reference preset total opening degree and the preset adjustment opening degree as a reference value, to coordinately adjust the first and second valve elements, thereby redistributing the refrigerant flow through the first and second valve elements and suppressing frost formation on the refrigerant-air heat exchanger and / or condensation on the heat dissipation branch.

[0006] The above technical solution has the following advantages or beneficial effects: This application combines system design and control optimization to provide a brand-new refrigerant heat dissipation layout. By controlling the refrigerant airflow in the refrigerant-water heat exchanger, the temperature of the refrigerant entering the heat dissipation module is adjusted, thereby expanding the boundary of heating operation and solving the heat dissipation condensation problem when heating hot water at high temperature and the inlet water temperature is low. At the same time, when heating at low temperature, it can improve the ice formation at the bottom of the refrigerant-air heat exchanger under harsh conditions, reduce the number of times the whole unit switches to the defrost mode, increase the defrost cycle, and improve the defrost effect. Through the cooperation of the first valve element, the second valve element, and the reheat exchange circuit, the two problems are solved in a comprehensive manner.

[0007] In some embodiments of this application, in the cooling mode, the control module is configured to: generate a preset total opening degree for the cooling mode based on a preset total opening degree; dynamically allocate opening weight coefficients for the first valve element and the second valve element, such that the first valve element is in the upper limit opening state corresponding to the preset total opening degree for the cooling mode, and the second valve element is in the lower limit opening state corresponding to the preset total opening degree for the cooling mode; and coordinately adjust the first valve element and the second valve element to guide the refrigerant flowing out of the refrigerant-water heat exchanger through the first valve element; wherein the preset total opening degree for the cooling mode is the same as the reference preset total opening degree.

[0008] The above technical solution has the following advantages or beneficial effects: In the refrigeration mode, based on the preset total opening degree of the refrigeration mode, the opening degree weight coefficients of the first valve element and the second valve element are dynamically allocated so that the first valve element is in the upper limit opening state corresponding to the preset total opening degree of the refrigeration mode, and the second valve element is in the lower limit opening state corresponding to the preset total opening degree of the refrigeration mode, thereby guiding the refrigerant flowing out of the refrigerant-water heat exchanger through the first valve element, and realizing precise control of the refrigerant flow path in the refrigeration mode.

[0009] In some embodiments of this application, in heating mode and when performing a defrost operation, the control module is configured to perform the following steps: presuming whether defrost intervention conditions are met; when defrost intervention conditions are met, generating a preset total opening degree for defrost operation based on the sum of a baseline preset total opening degree and a preset defrost opening degree; dynamically allocating the opening degree weight coefficients of the first valve element and the second valve element so that the first valve element is in a lower limit opening state corresponding to the preset total opening degree for defrost operation, and the second valve element is in an upper limit opening state corresponding to the preset total opening degree for defrost operation, guiding the refrigerant flowing out of the refrigerant-water heat exchanger to flow through the second valve element and flow in the reheat exchange loop.

[0010] The above technical solution has the following advantages or beneficial effects: When performing defrosting operation, the opening weight coefficients of the first valve element and the second valve element are dynamically allocated based on the preset total opening degree of the defrosting operation, so that the first valve element is in the lower limit opening state corresponding to the preset total opening degree of the defrosting operation, and the second valve element is in the upper limit opening state corresponding to the preset total opening degree of the defrosting operation, thereby guiding the refrigerant flowing out of the refrigerant-water heat exchanger to flow through the second valve element and flow in the reheat exchange circuit, thereby improving defrosting efficiency.

[0011] In some embodiments of this application, the defrosting intervention condition is: the temperature difference between the refrigerant and the air heat exchanger body is higher than a preset body temperature difference; wherein, the temperature difference between the refrigerant and the air heat exchanger body is the difference between the upper temperature of the refrigerant and the lower temperature of the refrigerant and the air heat exchanger.

[0012] The above technical solution has the following advantages or beneficial effects: by using defrosting intervention conditions, it is possible to promptly identify situations where the temperature difference between the upper and lower parts of the refrigerant-air heat exchanger is too large, accurately determine whether to intervene in the defrosting operation, thereby avoiding the impact of frost formation on the refrigerant-air heat exchanger on the heating effect and improving the operating efficiency of the air conditioning system.

[0013] In some embodiments of this application, the defrosting intervention conditions are: the refrigerant-air heat exchanger body temperature difference is higher than a preset body temperature difference; and during defrosting operation, the refrigerant-air heat exchanger sampling temperature is lower than the defrosting intervention outdoor ambient temperature; wherein, the refrigerant-air heat exchanger body temperature difference is the difference between the upper temperature and the lower temperature of the refrigerant-air heat exchanger, the defrosting intervention outdoor ambient temperature is generated based on the outdoor ambient temperature detected by the outdoor ambient temperature sensor, and the defrosting intervention outdoor ambient temperature is lower than the outdoor ambient temperature detected by the outdoor ambient temperature sensor.

[0014] The above technical solution has the following advantages or beneficial effects: by using defrosting intervention conditions, it is possible to promptly identify situations where the temperature difference between the upper and lower parts of the refrigerant-air heat exchanger is too large, and at the same time, it is possible to more comprehensively monitor the frosting situation of the refrigerant-air heat exchanger, thereby improving the accuracy of defrosting intervention.

[0015] In some embodiments of this application, under heating mode and when meeting the high-temperature hot water production condition, the control module is configured to: identify the condensation risk level based on a first relative temperature difference and a second relative temperature difference; dynamically allocate the opening weight coefficients of the first valve element and the second valve element using a preset total opening degree as a reference value, so as to reduce the opening weight coefficient of the first valve element and increase the opening weight coefficient of the second valve element according to the identified condensation risk level; wherein, the first relative temperature difference is the temperature difference between the outdoor ambient temperature detected by the outdoor ambient temperature sensor and the electrical box temperature, and the second relative temperature difference is the temperature difference between the second end temperature of the heat dissipation branch and the electrical box temperature.

[0016] The above technical solution has the following advantages or beneficial effects: the condensation risk level is identified based on the first relative temperature difference and the second relative temperature difference, and the opening weight coefficients of the first valve element and the second valve element are dynamically adjusted. Thus, the opening of the first valve element is reduced and the opening of the second valve element is increased according to the condensation risk level, which effectively reduces the condensation risk and improves the safety and stability of the system.

[0017] In some embodiments of this application, under heating mode and when the high-temperature hot water production condition is met, the control module is configured to: generate a preset total opening degree for the heating mode based on the benchmark preset total opening degree; when the first relative temperature difference is higher than a preset condensation risk temperature difference threshold and the second relative temperature difference is higher than a preset heat dissipation temperature difference threshold, dynamically allocate the opening weight coefficients of the first valve element and the second valve element so that the first valve element is in the lower limit opening state corresponding to the preset total opening degree of the heating mode, and the second valve element is in the upper limit opening state corresponding to the preset total opening degree of the heating mode.

[0018] The above technical solution has the following advantages or beneficial effects: By monitoring the first relative temperature difference and the second relative temperature difference, when the first relative temperature difference and the second relative temperature difference are higher than the preset condensation risk temperature difference threshold and heat dissipation temperature difference threshold, respectively, the opening weight coefficients of the first valve element and the second valve element are dynamically adjusted so that the first valve element is in the lower limit opening state and the second valve element is in the upper limit opening state, thereby effectively reducing the condensation risk and optimizing the heat dissipation effect.

[0019] In some embodiments of this application, under heating mode and when the high-temperature hot water production condition is met, the control module is configured to: generate a preset total opening degree for the heating mode based on the benchmark preset total opening degree; when the first relative temperature difference is higher than a preset condensation risk temperature difference threshold and the second relative temperature difference is higher than a first preset heat dissipation temperature difference threshold, dynamically allocate the opening weight coefficients of the first valve element and the second valve element, so that the first valve element is in the lower limit opening state corresponding to the preset total opening degree of the heating mode, and the second valve element is in the upper limit opening state corresponding to the preset total opening degree of the heating mode; when the first relative temperature difference is higher than a preset condensation temperature difference threshold, and the second relative temperature difference is not higher than the first preset heat dissipation temperature difference threshold but lower than the second preset heat dissipation temperature difference threshold, the control module is configured to reduce the opening weight coefficient of the first valve element according to a first preset ratio, and according to the... The first preset ratio increases the opening weight coefficient of the second valve element; when the first relative temperature difference is higher than the preset condensation temperature difference threshold, the second relative temperature difference is not lower than the second preset heat dissipation temperature difference threshold, and not higher than the third preset heat dissipation temperature difference threshold, the control module is configured to decrease the opening weight coefficient of the first valve element according to the second preset ratio, and increase the opening weight coefficient of the second valve element according to the second preset ratio; when the first relative temperature difference is higher than the preset condensation temperature difference threshold, the second relative temperature difference is not lower than the second preset heat dissipation temperature difference threshold, but higher than the third preset heat dissipation temperature difference threshold, the control module is configured to decrease the opening weight coefficient of the first valve element according to the third preset ratio, and increase the opening weight coefficient of the second valve element according to the third preset ratio; wherein, the first preset ratio, the second preset ratio, and the third preset ratio increase sequentially.

[0020] The above technical solution has the following advantages or beneficial effects: it adopts a four-level regulation method, identifies the condensation risk level based on the first relative temperature difference and the second relative temperature difference, and triggers corresponding control, so that the first valve element and the second valve element are adjusted in opposite directions in proportion, and suppresses the condensation risk under high temperature hot water production conditions through refrigerant redistribution.

[0021] In some embodiments of this application, under heating mode and when the low-temperature heating condition is met, the control module is configured to: identify the frosting risk level based on the temperature difference between the refrigerant and the air heat exchanger body; call the preset frosting risk intervention opening corresponding to the frosting risk level according to the frosting risk level; generate the preset total opening for the low-temperature heating condition based on the sum of the baseline preset total opening and the preset frosting risk intervention opening; and dynamically allocate the opening weight coefficients of the first valve element and the second valve element, such that the opening weight coefficient of the second valve element is the ratio of the preset frosting risk intervention opening to the preset total opening for the low-temperature heating condition.

[0022] The above technical solution has the following advantages or beneficial effects: by identifying the temperature difference between the refrigerant and the air heat exchanger body, the frost risk level is determined, and the opening weight coefficients of the first valve element and the second valve element are adjusted according to the frost risk level, so that the opening weight coefficient of the second valve element matches the frost risk intervention opening and the preset total opening under low temperature heating conditions, thereby effectively reducing the frost risk and improving the heating efficiency and stable operation of the system.

[0023] In some embodiments of this application, the first valve is an electronic expansion valve or a solenoid valve; the second valve is an electronic expansion valve or a solenoid valve.

[0024] The above technical solution has the following advantages or beneficial effects: the electronic expansion valve has high-precision flow control capability and response speed, and can realize precise regulation of refrigerant flow; the solenoid valve can be used under low-cost requirements and plays the role of quickly switching branches.

[0025] Other features and advantages of the present invention will become clearer after reading the detailed embodiments of the invention in conjunction with the accompanying drawings. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1 This is a schematic diagram of the circulation system of an air conditioning system provided in some embodiments of the present invention;

[0028] Figure 2 This is a schematic diagram of the structure of an air conditioning system in cooling mode provided in some embodiments of the present invention;

[0029] Figure 3 This is a schematic diagram of the structure of an air conditioning system in heating mode provided in some embodiments of the present invention;

[0030] Figure 4 This is a schematic diagram of the circulation system of an air conditioning system provided in some embodiments of the present invention;

[0031] Figure 5 A flowchart of an air conditioning system provided in some embodiments of the present invention;

[0032] Figure 6 A flowchart of an air conditioning system provided in some embodiments of the present invention;

[0033] Figure 7 A flowchart of an air conditioning system provided in some embodiments of the present invention;

[0034] Figure 8 A flowchart of an air conditioning system provided in some embodiments of the present invention;

[0035] Figure 9 A flowchart of an air conditioning system provided in some embodiments of the present invention;

[0036] Figure 10 A flowchart of an air conditioning system provided in some embodiments of the present invention;

[0037] Figure 11 A flowchart of an air conditioning system provided in some embodiments of the present invention;

[0038] In the diagram: 10. Air conditioning system; 101. Compressor; 102. Outdoor unit; 103. Refrigerant-air heat exchanger; 104. Heat exchanger body; 105. Reheat exchange circuit; 106. Refrigerant-water heat exchanger; 107. First end of reheat exchange circuit; 108. Heat dissipation module; 109. Heat dissipation branch; 110. First throttling element; 111. Electrical box; 112. Indoor unit; 113. First valve element; 114. Reheat exchange circuit Second end; 115, Second valve element; 116, Switching valve; 117, Gas-liquid separator; 118, Indoor heat exchanger; 119, Second throttling element; 120, Gas-side shut-off valve; 121, Liquid-side shut-off valve; 122, First temperature sensor; 123, Second temperature sensor; 124, Third temperature sensor; 125, Fourth temperature sensor; 126, Fifth temperature sensor; 127, Sixth temperature sensor; 128, Control module. Detailed Implementation

[0039] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0040] In the description of this application, it should be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0041] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "a plurality of" means two or more.

[0042] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0043] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0044] The following disclosure provides many different embodiments or examples for implementing various structures of the invention. To simplify the disclosure, specific examples of components and arrangements are described below. These are merely examples and are not intended to limit the invention. Furthermore, reference numerals and / or letters may be repeated in different examples; such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed. In addition, examples of various specific processes and materials are provided in this invention, but those skilled in the art will recognize the application of other processes and / or the use of other materials.

[0045] From a thermodynamic perspective, an air conditioning system's circulation system includes an evaporator, compressor, condenser, and throttling device connected in sequence. The refrigeration cycle involves a series of processes, including compression, condensation, expansion, and evaporation, to cool or heat indoor spaces, or to heat domestic water.

[0046] Low-temperature, low-pressure refrigerant enters the compressor, which compresses it into high-temperature, high-pressure refrigerant gas and discharges the compressed refrigerant gas. The discharged refrigerant gas flows into the condenser. The condenser condenses the compressed refrigerant into a liquid phase, and the heat is released to the surrounding environment through the condensation process.

[0047] The throttling device causes the high-temperature, high-pressure liquid refrigerant that condenses in the condenser to expand into a low-pressure liquid refrigerant. The evaporator evaporates the refrigerant that has expanded in the throttling device, returning the low-temperature, low-pressure refrigerant gas to the compressor. The evaporator achieves its cooling effect by utilizing the latent heat of refrigerant evaporation to exchange heat with the material being cooled.

[0048] From a hardware architecture perspective, refer to the appendix. Figures 1 to 4 This application describes the circulation system of an air conditioning system provided by some embodiments. Figure 2 This is a schematic diagram of the air conditioning system's circulation system in cooling mode. Figure 3 This is a schematic diagram of the circulation system in the heating mode of an air conditioning system.

[0049] Figure 1 This is a schematic diagram of the circulation system of an air conditioning system 10 provided in some embodiments of this application, wherein the compressor 101 is the core component. The compressor 101 is used to compress the refrigerant, compressing the refrigerant from a low-pressure state to a high-pressure state, so that the refrigerant can effectively transfer heat in the refrigeration cycle. The outdoor unit 102 of the air conditioning system 10 refers to the part of the circulation system that includes the compressor 101.

[0050] The outdoor unit 102 also includes a refrigerant-air heat exchanger 103 and a refrigerant-water heat exchanger 106.

[0051] The refrigerant-air heat exchanger 103 is used for heat exchange between refrigerant and air. The refrigerant-air heat exchanger 103 includes a heat exchanger body 104 and a reheat exchange circuit 105. The refrigerant exchanges heat with air within the heat exchanger body 104. Heat exchanger pipes are provided within the heat exchanger body 104, through which the refrigerant flows, and air flows on the surface of the heat exchanger body 104 via a fan or natural convection. The reheat exchange circuit 105 is located below the heat exchanger body 104.

[0052] The refrigerant-water heat exchanger 106 is used for heat exchange between refrigerant and water, transferring heat from the refrigerant to the water, causing the water temperature to rise or fall. The heated water can be used in underfloor heating, radiator heating, and other heating systems to provide hot water circulation, or in domestic hot water supply systems to provide hot water. The water circuit is equipped with components such as a flow meter and a water pump to maintain normal operation; no further limitations are imposed on the water circuit design here.

[0053] The first end 107 of the reheat circuit 105 of the refrigerant-air heat exchanger 103 is fluidly connected to the refrigerant-water heat exchanger 106.

[0054] The heat dissipation module 108 uses the refrigerant in the circulation system to cool the electrical box 111. The heat dissipation module 108 includes a heat dissipation branch 109. The first end of the heat dissipation branch 109 is fluidly connected to the refrigerant-air heat exchanger 103. A first throttling element 110 (outdoor electronic expansion valve) is provided between the first end of the heat dissipation branch 109 and the refrigerant-air heat exchanger 103. The second end of the heat dissipation branch 109 is fluidly connected to the indoor unit 112. The electrical box 111 contains components such as a power module (not shown) and a control module 128. No further restrictions are placed on the type, quantity, or model of the electrical components in the electrical box 111.

[0055] The refrigerant-water heat exchanger 106 is fluidly connected to the second end of the heat dissipation branch 109. A first valve element 113 is provided between the refrigerant-water heat exchanger 106 and the second end of the heat dissipation branch 109. The first end of the first valve element 113 is fluidly connected to the refrigerant-water heat exchanger 106, and the second end of the first valve element 113 is fluidly connected, in one direction, to the second end 114 of the reheat exchange circuit 105 of the refrigerant-air heat exchanger 103, and in another direction, to the second end of the heat dissipation branch 109. The first valve element 113 is an electronic expansion valve or a solenoid valve.

[0056] A second valve element 115 is also provided between the first end 107 of the reheat exchange circuit 105 of the refrigerant-air heat exchanger 103 and the refrigerant-water heat exchanger 106. The second valve element 115 is an electronic expansion valve or a solenoid valve.

[0057] The outdoor unit 102 also includes a switching valve 116. The switching valve 116 is used to control the flow of refrigerant to switch between heating and cooling modes.

[0058] The outdoor unit 102 also includes a gas-liquid separator 117. The gas-liquid separator 117 separates the gas and liquid components of the refrigerant. Located on the suction side of the compressor 101, the gas-liquid separator 117 prevents liquid refrigerant from entering the compressor 101, thus protecting it from liquid slugging damage. Based on gravity or centrifugal force, the gas and liquid components of the refrigerant naturally separate upon entering the gas-liquid separator 117 due to their density difference. The lower density gaseous refrigerant rises to the top of the gas-liquid separator 117, while the higher density liquid refrigerant sinks to the bottom. The separated gaseous refrigerant enters the suction side of the compressor 101 through the upper outlet of the gas-liquid separator 117, while the separated liquid refrigerant is stored at the bottom of the gas-liquid separator 117 and returned to the refrigeration cycle via the oil return line, or processed in other ways.

[0059] The structure and function of the indoor unit 112 are described below.

[0060] The indoor unit 112 operates in either cooling or heating mode to utilize the energy generated by the outdoor unit 102 to lower or raise the indoor temperature.

[0061] In some embodiments of this application, the indoor unit 112 includes multiple indoor heat exchangers 118 connected in parallel. Each indoor heat exchanger 118 is equipped with a second throttling element 119, which is configured to reduce the pressure of the refrigerant and cause it to expand. A group of indoor heat exchangers 118 and second throttling elements 119 can be installed in a room and matched with an indoor fan, which can be an axial fan, a cross-flow fan, or other type of fan. The indoor fan is positioned close to the indoor heat exchangers 118.

[0062] Taking a four-way valve as the switching valve 111 as an example, the four ports of the four-way valve are respectively connected to the discharge pipe of the compressor 101, the suction pipe of the compressor 101, the refrigerant-air heat exchanger 103, and at least one indoor heat exchanger 118. The discharge pipe of the compressor 101 is further connected to the refrigerant-water heat exchanger 106. In cooling mode, the high-temperature and high-pressure refrigerant discharged by the compressor 101 enters the refrigerant-air heat exchanger 103 through the four-way valve, and can also enter the refrigerant-water heat exchanger 106 at the same time; in heating mode, the high-temperature and high-pressure refrigerant discharged by the compressor 101 enters at least one indoor heat exchanger 118 through the four-way valve, and can also enter the refrigerant-water heat exchanger 106 at the same time.

[0063] A gas-side shut-off valve 120 and a liquid-side shut-off valve 121 are also provided between the indoor unit 112 and the outdoor unit 102 to open or close the refrigerant passage between the indoor unit 112 and the outdoor unit 102. The gas-side shut-off valve 120 and the liquid-side shut-off valve 121 are usually located in the outdoor unit 102.

[0064] The air conditioning system 10 also includes a control module 128, which includes a central processing unit and a memory. The central processing unit performs various processing tasks according to the programs stored in the memory.

[0065] The air conditioning system 10 also includes a first temperature sensor 122 for detecting the temperature at the inlet of the heat dissipation branch, a second temperature sensor 123 for detecting the temperature of the electrical box 111, a third temperature sensor 124 for detecting the temperature of the heat dissipation module, a fourth temperature sensor 125 for detecting the outdoor ambient temperature, a fifth temperature sensor 126 for detecting the upper temperature of the refrigerant-air heat exchanger 103, and a sixth temperature sensor 127 for detecting the lower temperature of the refrigerant-air heat exchanger 103.

[0066] In cooling mode, the high-temperature and high-pressure refrigerant discharged from the compressor 101 enters the refrigerant-air heat exchanger 103 through the switching valve 111, where it condenses and the compressed refrigerant is condensed into a liquid phase. The refrigerant flowing out of the refrigerant-air heat exchanger 103 first passes through the first throttling element 110, then through the heat dissipation branch 109. After flowing out of the heat dissipation branch 109, it enters the indoor unit 112, further passes through the second throttling element 119 and the indoor heat exchanger 118, and returns to the outdoor unit 102. After passing through the gas-liquid separator 117, it returns to the compressor 101.

[0067] In heating mode, the high-temperature, high-pressure refrigerant discharged from compressor 101 enters at least one indoor heat exchanger 118 through switching valve 111, where it condenses into a liquid phase. The refrigerant flowing out of indoor heat exchanger 118 returns to outdoor unit 102 after passing through second throttling element 119, and then merges with the refrigerant flowing out of refrigerant-water heat exchanger 106. The merged refrigerant first passes through heat dissipation branch 109, then through first throttling element 110, and enters refrigerant-air heat exchanger 103. Refrigerant-air heat exchanger 103 acts as an evaporator, allowing the low-temperature, low-pressure refrigerant gas to return to compressor 101.

[0068] In heating mode, when the outdoor ambient temperature is low and the humidity is high, frost easily forms on the surface of the outdoor heat exchanger. Frost formation leads to a gradual decrease in heat exchange capacity, and the evaporation temperature also continuously decreases. When the frost layer reaches a certain thickness, the defrosting process needs to be initiated. However, the heat generated during defrosting is usually limited to the fin surface. Under harsh operating conditions, the water generated from melting the frost may freeze at the bottom of the heat exchanger and on the machine chassis. This not only further reduces the defrosting effect but also shortens the defrosting cycle, and in severe cases, may cause the air conditioning system to malfunction and fail to operate continuously.

[0069] In heating mode, if the outdoor ambient temperature is high but the inlet water temperature of the refrigerant-water heat exchanger 106 is low, the condensation temperature of the refrigerant-water heat exchanger 106 will be low. The low temperature of the refrigerant flowing out of the refrigerant-water heat exchanger 106 results in a low temperature of the refrigerant entering the heat dissipation branch 109 after merging. If the temperature difference between the refrigerant entering the heat dissipation branch 109 and the surrounding air is large, the risk of condensation is high.

[0070] To address the aforementioned issues, in some embodiments of this application, the control module 128 is configured to dynamically allocate the opening weight coefficients of the first valve element and the second valve element using a reference preset total opening degree or the sum of the reference preset total opening degree and the preset adjustment opening degree as a reference value. This coordinates the adjustment of the first valve element 113 and the second valve element 115, thereby redistributing the refrigerant flow through the first valve element 113 and the second valve element 115 and suppressing frost formation on the refrigerant-air heat exchanger and / or condensation on the heat dissipation branch. The sum of the opening weight coefficients of the first and second valve elements is 1.

[0071] The first and second valve elements are described as electronic expansion valves.

[0072] like Figure 5 In the cooling mode, the control module 128 is configured to perform the following steps:

[0073] Step S101: Generate the preset total opening degree of the cooling mode based on the baseline preset total opening degree.

[0074] Step S102: Dynamically allocate the opening weight coefficient of the first valve element and the opening weight coefficient of the second valve element so that the first valve element is in the upper limit opening state corresponding to the preset total opening of the refrigeration mode, and the second valve element is in the lower limit opening state corresponding to the preset total opening of the refrigeration mode. The first valve element and the second valve element are coordinated to guide the refrigerant flowing out of the refrigerant-water heat exchanger through the first valve element and flow in the refrigeration cycle; wherein, the preset total opening of the refrigeration mode is the same as the reference preset total opening.

[0075] like Figure 6When in heating mode and performing a defrost operation, the control module 128 is configured to perform the following steps:

[0076] Step S201: Determine whether the defrosting intervention conditions are met.

[0077] Step S202: When the defrosting intervention conditions are met, generate the preset total opening degree for defrosting operation based on the sum of the baseline preset total opening degree and the preset defrosting opening degree.

[0078] Step S203: Dynamically allocate the opening weight coefficient of the first valve element and the opening weight coefficient of the second valve element so that the first valve element is in the lower limit opening state corresponding to the preset total opening of the defrosting operation, and the second valve element is in the upper limit opening state corresponding to the preset total opening of the defrosting operation, so as to guide the refrigerant flowing out of the refrigerant-water heat exchanger through the second valve element and flow in the reheat exchange circuit.

[0079] In some embodiments of this application, the defrosting intervention condition is: the temperature difference between the refrigerant and the air heat exchanger body is higher than a preset body temperature difference; wherein the temperature difference between the refrigerant and the air heat exchanger body is the difference between the upper temperature of the refrigerant and the lower temperature of the refrigerant and the air heat exchanger.

[0080] In some embodiments of this application, the defrosting intervention conditions are: the temperature difference between the refrigerant and air heat exchanger body is higher than the preset body temperature difference, and the sampling temperature of the refrigerant and air heat exchanger during defrosting operation is lower than the outdoor ambient temperature for defrosting intervention; wherein, the temperature difference between the refrigerant and air heat exchanger body is the difference between the upper temperature of the refrigerant and air heat exchanger and the lower temperature of the refrigerant air, and the outdoor ambient temperature for defrosting intervention is generated based on the outdoor ambient temperature detected by the outdoor ambient temperature sensor, and is lower than the outdoor ambient temperature detected by the outdoor ambient temperature sensor.

[0081] like Figure 7 In heating mode, the control module is configured to perform the following steps:

[0082] Step S301: Determine whether the high-temperature hot water production conditions are met.

[0083] Step S302: When the high-temperature hot water production condition is met, the condensation risk level is identified based on the first relative temperature difference and the second relative temperature difference.

[0084] Step S303: Using the preset total opening degree as the benchmark value, dynamically allocate the opening degree weight coefficient of the first valve element and the opening degree weight coefficient of the second valve element, so as to reduce the opening degree weight coefficient of the first valve element and increase the opening degree weight coefficient of the second valve element according to the corresponding proportion based on the identified condensation risk level; wherein, the first relative temperature difference is the temperature difference between the outdoor ambient temperature and the electrical box temperature, and the second relative temperature difference is the temperature difference between the second end temperature of the heat dissipation branch and the electrical box temperature.

[0085] like Figure 8 In some other embodiments of this application, in heating mode, the control module 128 is configured to perform the following steps:

[0086] Step S401: Determine whether the high-temperature hot water production conditions are met.

[0087] Step S402: When the high-temperature hot water production condition is met, generate the preset total opening degree of the heating mode based on the benchmark preset total opening degree.

[0088] Step S403: Determine whether the first relative temperature difference is higher than the preset condensation risk temperature difference threshold.

[0089] Step S404: If the first relative temperature difference is higher than the preset condensation risk temperature difference threshold, it is presumed that the second relative temperature difference is higher than the preset heat dissipation temperature difference threshold.

[0090] Step S405: If the second relative temperature difference is higher than the preset heat dissipation temperature difference threshold, the opening weight coefficient of the first valve element and the opening weight coefficient of the second valve element are dynamically allocated so that the first valve element is in the lower limit opening state corresponding to the preset total opening of the heating mode, and the second valve element is in the upper limit opening state corresponding to the preset total opening of the heating mode.

[0091] like Figure 9 In some other embodiments of this application, in heating mode, the control module 128 is configured to perform the following steps:

[0092] Step S 501: Determine whether the high-temperature hot water production conditions are met.

[0093] Step S502: If the high-temperature hot water production condition is met, generate the preset total opening degree of the heating mode based on the benchmark preset total opening degree.

[0094] Step S 503: Determine whether the first relative temperature difference is higher than the preset condensation risk temperature difference threshold.

[0095] Step S504: If the first relative temperature difference is higher than the preset condensation risk temperature difference threshold, then it is presumed whether the second relative temperature difference is higher than the first preset heat dissipation temperature difference threshold.

[0096] Step S505: If the second relative temperature difference is higher than the first preset heat dissipation temperature difference threshold, then dynamically allocate the opening weight coefficient of the first valve element and the opening weight coefficient of the second valve element so that the first valve element is in the lower limit opening state corresponding to the preset total opening of the heating mode, and the second valve element is in the upper limit opening state corresponding to the preset total opening of the heating mode.

[0097] Step S506: If the second relative temperature difference is not higher than the first preset heat dissipation temperature difference threshold, then it is presumed whether the second relative temperature difference is lower than the second preset heat dissipation temperature difference threshold.

[0098] Step S507: If the temperature difference is lower than the second preset heat dissipation temperature difference threshold, the opening weight coefficient of the first valve element is reduced by the first preset ratio, and the opening weight coefficient of the second valve element is increased by the first preset ratio.

[0099] Step S508: If the second relative temperature difference is not lower than the second preset heat dissipation temperature difference threshold, then it is presumed that the second relative temperature difference is not higher than the third preset heat dissipation temperature difference threshold.

[0100] Step S509: If the opening weight coefficient of the first valve element is not higher than the third preset heat dissipation temperature difference threshold, then the opening weight coefficient of the second valve element is reduced by the second preset ratio, and the opening weight coefficient of the second valve element is increased by the second preset ratio.

[0101] Step S510: If the second relative temperature difference is not lower than the second preset heat dissipation temperature difference threshold but higher than the third preset heat dissipation temperature difference threshold, then the opening weight coefficient of the first valve element is reduced according to the third preset ratio, and the opening weight coefficient of the second valve element is increased according to the third preset ratio; wherein, the first preset ratio, the second preset ratio and the third preset ratio increase sequentially.

[0102] like Figure 9 In some other embodiments of this application, in heating mode, the control module 128 is configured to perform the following steps:

[0103] Step S 601: Determine whether the low-temperature heating condition is met.

[0104] Step S602: If the low-temperature heating condition is met, identify the frost risk level based on the temperature difference between the refrigerant and the air heat exchanger body.

[0105] Step S603: Call the preset frost risk intervention setting corresponding to the frost risk level.

[0106] Step S604: Generate the preset total opening degree for low-temperature heating conditions based on the sum of the baseline preset total opening degree and the preset frost risk intervention opening degree.

[0107] Step S605: Dynamically allocate the opening weight coefficient of the first valve element and the opening weight coefficient of the second valve element, wherein the opening weight coefficient of the second valve element is the ratio of the preset frosting risk intervention opening to the preset total opening under low temperature heating conditions.

[0108] In some embodiments of this application, the control module is configured to perform, as Figure 11 The following steps are shown:

[0109] Step S701: Determine whether to execute the cooling mode;

[0110] Step S702: If yes, generate a baseline preset total opening E0 based on the required oil return volume, and generate a cooling mode preset total opening ∑EVW_cooling based on the baseline preset total opening E0, i.e., ∑EVW_cooling=E0; dynamically allocate the first valve element opening weight coefficient W1 and the second valve element opening weight coefficient W2 so that the first valve element is in the upper limit opening state corresponding to the cooling mode preset total opening, i.e., the opening of the first valve element satisfies EVW1=∑EVW_cooling×W1, and the second valve element is in the lower limit opening state corresponding to the cooling mode preset total opening, i.e., the opening of the second valve element satisfies EVW2=∑EVW_cooling×W2, and coordinately adjust the first valve element and the second valve element to guide the refrigerant flowing out of the refrigerant-water heat exchanger through the first valve element and flow in the refrigeration cycle.

[0111] In cooling mode, the high-temperature, high-pressure refrigerant discharged from the compressor enters the refrigerant-air heat exchanger through a four-way valve, where it condenses, turning the compressed refrigerant into a liquid phase. The refrigerant flowing out of the heat exchanger first passes through the outdoor unit's throttling element, then through the heat dissipation branch. After flowing out of the heat dissipation branch, it enters the indoor unit, further passing through the indoor throttling element and the indoor heat exchanger, before returning to the outdoor unit. There, it passes through the gas-liquid separator and returns to the compressor. In this process, the refrigerant first condenses in the refrigerant-air heat exchanger and then passes through the heat dissipation module. In cooling mode, the refrigerant-air heat exchanger functions as a condenser, eliminating the risk of frosting. Furthermore, the risk of condensation in the heat dissipation branch downstream of the refrigerant-air heat exchanger is also very low.

[0112] Therefore, in cooling mode, a baseline preset total opening is generated based on the required oil return volume, and a cooling mode baseline preset total opening is further generated based on the baseline preset total opening. The opening weight coefficient of the first valve element is set to 1, and the opening weight coefficient of the second valve element is set to 0, so that the first valve element is in the upper limit opening state corresponding to the cooling mode preset total opening, and the second valve element is in the lower limit opening state corresponding to the cooling mode preset total opening. The first valve element and the second valve element are adjusted in a coordinated manner to guide the refrigerant flowing out of the refrigerant-water heat exchanger through the first valve element and flow in the refrigeration cycle, so as to avoid the accumulation of lubricating oil.

[0113] For example, the required oil return volume is related to the system design and the type of compressor, and can be pre-calculated and stored using a simulation system for later retrieval. Based on the required oil return volume, the required refrigerant flow rate can be further calculated using empirical formulas and the currently selected refrigerant type; after obtaining the refrigerant flow rate, a baseline preset total opening can be generated based on the relationship between the flow rate and the valve opening.

[0114] The baseline preset total opening can also be a fixed value obtained and pre-stored under experimental conditions. The baseline preset total opening can also be calculated in other ways, which will not be listed here.

[0115] Since there is no risk of condensation or frost in cooling mode, the preset total opening degree for cooling mode is the baseline preset total opening degree.

[0116] Step S703: If not, then execute the heating mode.

[0117] Step S 704: Further determine whether to perform a defrosting operation in heating mode.

[0118] Step S705: If yes, then it is presumed whether the defrosting intervention conditions are met.

[0119] Step S706: When the defrosting intervention conditions are met, a baseline preset total opening E0 is generated based on the required oil return volume, and a defrosting operation preset total opening ∑EVW_th is generated based on the baseline preset total opening E0 and the preset defrosting opening E1, i.e., ∑EVW_th=E0+E1; the opening weight coefficient W1 of the first valve element and the opening weight coefficient W2 of the second valve element are dynamically allocated so that the first valve element is in the lower limit opening state corresponding to the defrosting operation preset total opening ∑EVW_th, and the second valve element is in the upper limit opening state corresponding to the defrosting operation preset total opening ∑EVW_th. The first valve element and the second valve element are coordinated to guide the refrigerant flowing out of the refrigerant-water heat exchanger through the second valve element and flow in the reheat exchange circuit.

[0120] For example, a two-factor judgment method based on temperature (pressure) and time is used for defrosting control, that is, setting the heating operation cycle time and the defrosting time point. When both time and temperature are simultaneously satisfied, the defrosting operation is initiated. During defrosting operation, a four-way valve is used to switch from heating mode to cooling mode, and the frost layer is melted by heating with refrigerant.

[0121] In some embodiments of this application, defrosting intervention conditions include a refrigerant-air heat exchanger body temperature difference that is higher than a preset body temperature difference.

[0122] Specifically, the upper temperature T of the sampled refrigerant-air heat exchanger is... e1 and the temperature T at the bottom of the refrigerant-air heat exchanger e2 Calculate the refrigerant-air heat exchanger body temperature difference T between the upper and lower temperatures of the refrigerant-air heat exchanger. e1 -T e2 When the temperature difference between the refrigerant and the air heat exchanger body is higher than the preset body temperature difference (i.e., T...), e1 -T e2>t1), presumably meeting the defrosting intervention conditions, indicates that the temperature at the bottom of the refrigerant-air heat exchanger is lower than the temperature at the top. Therefore, based on the baseline preset total opening E0 and the preset defrost opening E1, a preset total opening for defrosting operation ∑EVW_th is generated, i.e., ∑EVW_th = E0 + E1. The opening weight coefficients W1 and W2 of the first and second valve elements are dynamically allocated so that the first valve element is at the lower limit opening state corresponding to the preset total opening for defrosting operation ∑EVW_th, and the second valve element is at the upper limit opening state corresponding to the preset total opening for defrosting operation ∑EVW_th. The first and second valve elements are coordinated to guide the refrigerant flowing from the refrigerant-water heat exchanger through the second valve element and into the reheat exchange loop. The preset total opening for defrosting operation is greater than the preset total opening for cooling mode, thereby strengthening the bottom defrosting of the refrigerant-air heat exchanger.

[0123] The preset total opening degree for defrosting operation is the sum of the baseline preset total opening degree and the preset defrosting opening degree. When dynamically allocating the opening weight coefficients of the first valve element and the second valve element, the opening weight coefficient of the first valve element is set to 0, and the opening weight coefficient of the second valve element is set to 1. This ensures that the first valve element is in the lower limit opening state corresponding to the preset total opening degree for defrosting operation, and the second valve element is in the upper limit opening state corresponding to the preset total opening degree for defrosting operation. The first and second valve elements are coordinated to guide the refrigerant flowing out of the refrigerant-water heat exchanger through the second valve element and flow in the reheat exchange circuit, preventing the water generated by melting the frost layer from freezing at the bottom of the heat exchanger and on the machine chassis.

[0124] The defrosting operation includes a preset defrosting cycle time and defrosting end temperature. Defrosting ends when both the time and temperature are met.

[0125] In some embodiments of this application, the defrosting intervention conditions include a refrigerant-air heat exchanger body temperature difference higher than a preset body temperature difference, and the refrigerant-air heat exchanger sampling temperature during defrosting operation being lower than the outdoor ambient temperature during defrosting intervention. Specifically, the sampling temperature T at the top of the refrigerant-air heat exchanger... e1 and the temperature T at the bottom of the refrigerant-air heat exchanger e2 Calculate the refrigerant-air heat exchanger body temperature difference T between the upper and lower temperatures of the refrigerant-air heat exchanger. e1 -T e2 The lowest temperature of the refrigerant-air heat exchanger under defrosting operation is taken as the refrigerant-air heat exchanger sampling temperature T. e And based on the current outdoor ambient temperature, generate the outdoor ambient temperature t for defrosting intervention. fr1 When the temperature difference between the refrigerant and the air heat exchanger body is higher than the preset body temperature difference (i.e., T), e1 -T e2>t1), and the refrigerant-air heat exchanger sampling temperature T e The outdoor ambient temperature t below the defrosting intervention level fr1 When the required oil return volume and preset defrost opening are met, a preset total defrost operation opening of ∑EVW_th is generated. The opening weight coefficients W1 and W2 of the first and second valve elements are dynamically allocated so that the first valve element is at its lower limit opening state corresponding to the preset total defrost operation opening of ∑EVW_th, and the second valve element is at its upper limit opening state corresponding to the preset total defrost operation opening of ∑EVW_th. The first and second valve elements are coordinated to guide the refrigerant flowing from the refrigerant-water heat exchanger through the second valve element and into the reheat exchange circuit. The preset total defrost operation opening is greater than the preset total opening for cooling mode, thereby enhancing the bottom defrosting of the refrigerant-air heat exchanger.

[0126] If the refrigerant-air heat exchanger body temperature difference is not higher than the preset body temperature difference (i.e., T...), e1 -T e2 >t1), and the refrigerant-air heat exchanger sampling temperature T e The outdoor ambient temperature t below the defrosting intervention level fr1 When the required oil return is reached, the system generates a preset total defrost operation opening ∑EVW_th based solely on the required oil return volume. It then dynamically allocates the opening weight coefficients W1 and W2 of the first and second valve elements to ensure that the first valve element is at its lower limit opening corresponding to the preset total defrost operation opening ∑EVW_th, and the second valve element is at its upper limit opening corresponding to the preset total defrost operation opening ∑EVW_th. This coordinated adjustment of the first and second valve elements guides the refrigerant flowing from the refrigerant-water heat exchanger through the second valve element and into the reheat exchange circuit. Figure 11 As shown in step S724.

[0127] In some embodiments of this application, the outdoor ambient temperature during defrosting is t. fr1 , t fr1 =T a ×ab, where T a Let a be the temperature detected by the outdoor ambient temperature sensor, and b be constants, where a < 1 and b > 10. By intervening in the outdoor ambient temperature during defrosting, harsh outdoor environmental conditions can be identified, and defrosting intervention control can be performed at the precise time.

[0128] Step S707: If defrosting is not performed, the heating mode is executed. A baseline preset total opening E0 is generated based on the required oil return volume, and a heating mode preset total opening ∑EVW_heating is generated based on the baseline preset total opening E0. The opening weight coefficient W1 of the first valve element and the opening weight coefficient W2 of the second valve element are dynamically allocated so that the first valve element is in the upper limit opening state corresponding to the heating mode preset total opening ∑EVW_heating, and the second valve element is in the lower limit opening state corresponding to the heating mode preset total opening ∑EVW_heating. The first valve element and the second valve element are coordinated to guide the refrigerant flowing out of the refrigerant-water heat exchanger through the first valve element and flow in the refrigeration cycle.

[0129] Set the preset total opening degree of the heating mode to the baseline preset total opening degree, i.e., ∑EVW_heating=E0.

[0130] Further investigation is needed to determine whether this is a high-temperature hot water production operation.

[0131] Specifically, determining whether a system is operating at high temperatures for hot water production includes:

[0132] Step S708: First, estimate the outdoor ambient temperature T. a Does the preset high-temperature condition meet, for example, when the outdoor ambient temperature is higher than the set high-temperature threshold (T)? a When >T1), the estimated outdoor ambient temperature T a The preset high temperature conditions are met.

[0133] Step S709: If the outdoor ambient temperature T a If the preset high-temperature condition is met, the system further identifies whether the water circulation is operational. For example, the operation of the water pump can be used to determine if the water circulation is running. If the water circulation is running, it is presumed to be in high-temperature hot water production mode.

[0134] Step S710: If the water circulation is in a non-operational state, keep ∑EVW_heating=E0 unchanged.

[0135] Under high-temperature hot water production conditions, if the inlet water temperature is low, the refrigerant temperature flowing out of the refrigerant-water heat exchanger will be relatively low. This will result in the refrigerant entering the heat dissipation branch after merging being at a low temperature. During further heat exchange, if the temperature difference between the refrigerant in the heat dissipation branch and the surrounding air temperature is large, the possibility of reaching or falling below the dew point temperature is higher, and the corresponding heat dissipation branch has a high risk of condensation.

[0136] Step S711: Further estimate the outdoor ambient temperature T a and electrical box temperature T ca Is the first relative temperature difference between them higher than the preset condensation risk temperature difference threshold T? c2That is, T a -T ca >T c2 If not, keep ∑EVW_heating=E0 unchanged, as shown in step S710.

[0137] Step S712: If the first relative temperature difference T a -T ca Temperature difference exceeding the preset condensation risk threshold T c2 Then, the temperature T at the second end of the heat dissipation branch can be further estimated. cb and electrical box temperature T ca Is the second relative temperature difference higher than the first preset heat dissipation temperature difference threshold T? c1 That is, T cb -T ca >T c1 .

[0138] Step S713: If the second relative temperature difference is higher than the first preset heat dissipation temperature difference threshold T c1 This indicates a high risk of condensation. The opening weight coefficients W1 and W2 of the first and second valve elements are dynamically allocated to ensure that the first valve element is at its lower limit opening corresponding to the preset total opening of the heating mode ∑EVW_heating, and the second valve element is at its upper limit opening corresponding to the preset total opening of the heating mode ∑EVW_heating. This reduces the amount of low-temperature refrigerant entering the system, narrows the temperature difference between the refrigerant in the heat dissipation branch and the surrounding air, and reduces the risk of condensation. Where T... c1 >T c2 .

[0139] Step S714: If the second relative temperature difference is not higher than the first preset heat dissipation temperature difference threshold T c1 Then it is further inferred whether the second relative temperature difference is lower than the second preset heat dissipation temperature difference threshold T. f2 That is, T cb -T ca <T f2 .

[0140] Step S715: If the temperature difference is below the second preset threshold T f2 Then, according to the first preset ratio w3, the opening weight coefficient W1 of the first valve element is reduced, and the opening weight coefficient W2 of the second valve element is increased according to the first preset ratio w3. This reduces the opening of the first valve element and increases the opening of the second valve element, thus coordinating the adjustment of the first and second valve elements to reduce the flow rate of refrigerant flowing from the refrigerant-water heat exchanger through the first valve element and guides some refrigerant to flow in the reheat exchange circuit. That is, W1 = 1 - k * w3, W2 = k * w3, where k is a constant, a positive integer, representing the valve adjustment cycle.

[0141] Step S716: If the temperature difference is not lower than the second preset temperature difference threshold T f2 Then it is further inferred whether the second relative temperature difference is higher than the third preset heat dissipation temperature difference threshold T. f1 ;T f1 >T f2 .

[0142] Step S717: If it is not higher than the third preset temperature difference threshold T f1 Then, the opening weight coefficient W1 of the first valve element is reduced according to the second preset ratio w2, and the opening weight coefficient W2 of the second valve element is increased according to the second preset ratio w2, so as to reduce the opening of the first valve element and increase the opening of the second valve element by a larger proportion, and coordinate the adjustment of the first valve element and the second valve element to reduce the flow rate of refrigerant flowing from the refrigerant-water heat exchanger through the first valve element by a larger proportion, and guide more refrigerant to flow in the reheat exchange circuit.

[0143] Step S718: If the temperature difference is higher than the third preset temperature difference threshold T f1 Then, the opening weight coefficient W1 of the first valve element is reduced according to the third preset ratio w1, and the opening weight coefficient W2 of the second valve element is increased according to the third preset ratio w1, so as to reduce the opening of the first valve element and increase the opening of the second valve element by a larger proportion, and coordinate the adjustment of the first valve element and the second valve element to reduce the flow rate of refrigerant flowing from the refrigerant-water heat exchanger through the first valve element by a larger proportion, and guide more refrigerant to flow in the reheat exchange circuit.

[0144] In general, the above implementation adopts a four-level adjustment method. The condensation risk level is identified based on the first relative temperature difference and the second relative temperature difference, and the corresponding control is triggered so that the first valve element and the second valve element are adjusted in opposite directions in proportion. The risk of condensation under high temperature hot water production is suppressed by refrigerant redistribution.

[0145] Among them, the third preset ratio w1, the second preset ratio w2 and the first preset ratio w3 decrease sequentially.

[0146] Further determine whether it is a low-temperature heating condition under heating mode.

[0147] Specifically, determining whether it is a low-temperature heating condition includes: determining whether the outdoor ambient temperature meets the preset low-temperature conditions.

[0148] Step S719: At an outdoor ambient temperature T a When the temperature is below the set low temperature threshold T2 (T a <T2), estimated outdoor ambient temperature T a It meets the preset low temperature conditions.

[0149] Further, the risk of frost formation can be identified based on the temperature difference between the refrigerant and the air heat exchanger body.

[0150] Step S720: Determine whether the body temperature difference is higher than the preset first frost risk temperature difference threshold, i.e., T e1 -T e2 >t2.

[0151] Step S721: If the temperature difference exceeds the preset first frosting risk threshold, then generate the first low-temperature heating condition preset total opening ∑EVW_in1 based on the benchmark preset opening E0 and the first preset frosting risk intervention opening E2. Dynamically allocate the first valve element opening weight coefficient W1 and the second valve element opening weight coefficient W2, where the second valve element opening weight coefficient is the ratio of the first preset frosting risk intervention opening to the low-temperature heating condition preset total opening, i.e., W2=E2 / ∑EVW_in1, W1=1-E2 / ∑EVW_in1. This increases the opening of the second valve element on the basis of increasing the benchmark preset total opening, allowing more refrigerant to flow in the reheat exchange circuit and reducing the frosting risk.

[0152] Step S722: If the temperature difference is not higher than the preset first frost risk temperature difference threshold, then it is presumed whether the body temperature difference is higher than the second frost risk temperature difference threshold, i.e., T. e1 -T e2 >t3.

[0153] Step S723: If the temperature difference exceeds the preset second frost risk threshold, a second low-temperature heating condition preset total opening ∑EVW_in2 is generated based on the baseline preset opening E0 and the second preset frost risk intervention opening E3. The opening weight coefficients W1 and W2 of the first and second valve elements are dynamically allocated. The opening weight coefficient of the second valve element is the ratio of the second preset frost risk intervention opening to the preset total opening of the low-temperature heating condition, i.e., W2 = E3 / ∑EVW_in2, W1 = 1 - E3 / ∑EVW_in2. The second frost risk temperature difference threshold t3 is less than the first frost risk temperature difference threshold t2, and the first frost risk temperature difference threshold t2 is less than the preset body temperature difference t1. The corresponding increase in the opening of the second valve element is smaller, more accurately suppressing the frost risk. If the temperature difference does not exceed the preset second frost risk threshold, normal heating control is applied.

[0154] In this embodiment, the risk of frosting is determined by the temperature difference between the refrigerant and the air heat exchanger body. If the body temperature difference is higher than a preset first frosting risk temperature difference threshold, it indicates a high risk of frosting; if the body temperature difference is only higher than a second frosting risk temperature difference threshold but lower than the first frosting risk temperature difference threshold, it indicates a low risk of frosting but still requires intervention. After identifying the frosting risk, two levels of intervention are implemented according to the identified frosting risk level. When the frosting risk is high, a strong intervention is triggered to guide more refrigerant into the reheat exchanger branch. When the frosting risk is medium, a weak intervention is triggered to avoid excessive adjustment affecting energy efficiency. The reference preset total opening is increased by the first and second preset frosting risk intervention openings to ensure dynamic balance of flow in the refrigeration cycle and the reheat exchanger loop.

[0155] The preset defrost setting E1, the first preset frost risk intervention setting E2, and the third preset frost risk intervention setting E2 decrease sequentially.

[0156] In the description of the above embodiments, specific features, structures, materials, or characteristics may be combined in any suitable manner in one or more embodiments or examples.

[0157] The above are merely specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. Air conditioning system, including: A refrigerant-air heat exchanger is used to exchange heat between a refrigerant and air. A refrigerant-water heat exchanger is used for heat exchange between a refrigerant and water. A heat dissipation module that uses refrigerant to dissipate heat from the electrical box; it includes: A heat dissipation branch, the first end of which is fluidly connected to the refrigerant-air heat exchanger, and a first throttling element is provided between the first end of the heat dissipation branch and the refrigerant-air heat exchanger; Its features are: The refrigerant-air heat exchanger includes: Heat exchanger body; A reheat exchange circuit is provided below the heat exchanger body, and the first end of the reheat exchange circuit is fluidly connected to the refrigerant-water heat exchanger. A first valve element, with its first end fluidly connected to the refrigerant-water heat exchanger, and its second end fluidly connected in one direction to the second end of the reheat exchange circuit, and in another direction to the second end of the heat dissipation branch; A second valve element is disposed between the first end of the reheat exchange circuit and the refrigerant-water heat exchanger; and The control module is configured to dynamically allocate the opening weight coefficient of the first valve element and the opening weight coefficient of the second valve element based on the reference preset total opening degree or the sum of the reference preset total opening degree and the preset adjustment opening degree as the reference value, so as to coordinately adjust the first valve element and the second valve element, so that the refrigerant flow through the first valve element and the second valve element is redistributed, thereby suppressing the frost formation of the refrigerant-air heat exchanger and / or the condensation of the heat dissipation branch.

2. The air conditioning system according to claim 1, characterized in that: In cooling mode, the control module is configured as follows: The cooling mode is generated based on the preset total opening degree; The opening weight coefficients of the first valve element and the second valve element are dynamically allocated so that the first valve element is in the upper limit opening state corresponding to the preset total opening of the refrigeration mode, and the second valve element is in the lower limit opening state corresponding to the preset total opening of the refrigeration mode. The first valve element and the second valve element are coordinated to guide the refrigerant flowing out of the refrigerant-water heat exchanger through the first valve element; wherein the preset total opening of the refrigeration mode is the same as the reference preset total opening.

3. The air conditioning system according to claim 1, characterized in that: In heating mode, and when performing a defrost operation, the control module is configured to perform the following steps: Determine whether the conditions for defrosting intervention are met; When the defrosting intervention conditions are met, the preset total opening degree for defrosting operation is generated based on the sum of the baseline preset total opening degree and the preset defrosting opening degree; The opening weight coefficients of the first valve element and the second valve element are dynamically allocated so that the first valve element is in the lower limit opening state corresponding to the preset total opening of the defrosting operation, and the second valve element is in the upper limit opening state corresponding to the preset total opening of the defrosting operation, so as to guide the refrigerant flowing out of the refrigerant-water heat exchanger to flow through the second valve element and flow in the reheat exchange circuit.

4. The air conditioning system according to claim 3, characterized in that: The defrosting intervention conditions are as follows: The refrigerant-air heat exchanger body temperature difference is higher than the preset body temperature difference; wherein, the refrigerant-air heat exchanger body temperature difference is the difference between the upper temperature of the refrigerant-air heat exchanger and the lower temperature of the refrigerant-air heat exchanger.

5. The air conditioning system according to claim 3, characterized in that: The defrosting intervention conditions are as follows: The refrigerant-air heat exchanger body temperature difference is higher than the preset body temperature difference; and During defrosting operation, the sampling temperature of the refrigerant-air heat exchanger is lower than the outdoor ambient temperature at which defrosting occurs; The refrigerant-air heat exchanger body temperature difference is the difference between the upper temperature and the lower temperature of the refrigerant-air heat exchanger. The defrosting intervention outdoor ambient temperature is generated based on the outdoor ambient temperature detected by the outdoor ambient temperature sensor. The defrosting intervention outdoor ambient temperature is lower than the outdoor ambient temperature detected by the outdoor ambient temperature sensor.

6. The air conditioning system according to claim 1, characterized in that: In heating mode, and when the high-temperature hot water production condition is met, the control module is configured as follows: Condensation risk levels are identified based on the first and second relative temperature differences. Using the preset total opening degree as a benchmark value, the opening degree weight coefficients of the first valve element and the second valve element are dynamically allocated. The opening degree weight coefficient of the first valve element is reduced proportionally according to the identified condensation risk level, and the opening degree weight coefficient of the second valve element is increased. The first relative temperature difference is the temperature difference between the outdoor ambient temperature detected by the outdoor ambient temperature sensor and the electrical box temperature, and the second relative temperature difference is the temperature difference between the second end temperature of the heat dissipation branch and the electrical box temperature.

7. The air conditioning system according to claim 6, characterized in that: In heating mode, and when the high-temperature hot water production condition is met, the control module is configured as follows: The preset total opening degree of the heating mode is generated based on the aforementioned benchmark preset total opening degree; When the first relative temperature difference is higher than the preset condensation risk temperature difference threshold and the second relative temperature difference is higher than the preset heat dissipation temperature difference threshold, the opening weight coefficients of the first valve element and the second valve element are dynamically allocated so that the first valve element is in the lower limit opening state corresponding to the preset total opening of the heating mode, and the second valve element is in the upper limit opening state corresponding to the preset total opening of the heating mode.

8. The air conditioning system according to claim 6, characterized in that: In heating mode, and when the high-temperature hot water production condition is met, the control module is configured as follows: The preset total opening degree of the heating mode is generated based on the aforementioned benchmark preset total opening degree; When the first relative temperature difference is higher than the preset condensation risk temperature difference threshold and the second relative temperature difference is higher than the first preset heat dissipation temperature difference threshold, the opening weight coefficients of the first valve element and the second valve element are dynamically allocated so that the first valve element is in the lower limit opening state corresponding to the preset total opening of the heating mode, and the second valve element is in the upper limit opening state corresponding to the preset total opening of the heating mode. When the first relative temperature difference is higher than the preset condensation temperature difference threshold, and the second relative temperature difference is not higher than the first preset heat dissipation temperature difference threshold but lower than the second preset heat dissipation temperature difference threshold, the control module is configured to reduce the opening weight coefficient of the first valve element according to the first preset ratio, and increase the opening weight coefficient of the second valve element according to the first preset ratio. When the first relative temperature difference is higher than the preset condensation temperature difference threshold, the second relative temperature difference is not lower than the second preset heat dissipation temperature difference threshold, and not higher than the third preset heat dissipation temperature difference threshold, the control module is configured to reduce the opening weight coefficient of the first valve element according to the second preset ratio, and increase the opening weight coefficient of the second valve element according to the second preset ratio. When the first relative temperature difference is higher than the preset condensation temperature difference threshold, and the second relative temperature difference is not lower than the second preset heat dissipation temperature difference threshold but higher than the third preset heat dissipation temperature difference threshold, the control module is configured to reduce the opening weight coefficient of the first valve element according to the third preset ratio, and increase the opening weight coefficient of the second valve element according to the third preset ratio. The first preset ratio, the second preset ratio, and the third preset ratio increase sequentially.

9. The air conditioning system according to claim 8, characterized in that: In heating mode, and when the low-temperature heating condition is met, the control module is configured as follows: Frosting risk level is identified based on the temperature difference between the refrigerant and the air heat exchanger body. The preset frost risk intervention setting corresponding to the frost risk level is invoked according to the frost risk level. The preset total opening degree for low-temperature heating conditions is generated based on the sum of the baseline preset total opening degree and the preset frost risk intervention opening degree. The opening weight coefficients of the first valve element and the second valve element are dynamically allocated, such that the opening weight coefficient of the second valve element is the ratio of the preset frosting risk intervention opening to the preset total opening under the low temperature heating condition.

10. The air conditioning system according to claim 1, characterized in that: The first valve is an electronic expansion valve or a solenoid valve; The second valve is an electronic expansion valve or a solenoid valve.

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