An air conditioner

Abstract

Embodiments of the present application provide an air conditioner, comprising: an indoor unit, an outdoor unit, the outdoor unit comprising: a compressor; an outdoor heat exchanger; an electrical module comprising: an electrical box provided with a plurality of electrical devices; a refrigerant radiator; an outdoor expansion valve; a sensor module comprising: a first temperature sensor; a second temperature sensor; a third temperature sensor; a controller configured to: obtain a first temperature and a second temperature, the first temperature being a first electrical box temperature, the second temperature being an electrical box upper limit temperature, a target temperature or an outdoor environment temperature, or, the first temperature being a refrigerant inlet temperature and the second temperature being an outdoor environment temperature; and control the opening degree of the outdoor expansion valve according to the first temperature and the second temperature. The above technical solution controls the opening degree of the outdoor expansion valve, so that the electrical box temperature is controlled within a suitable temperature range, effectively reducing the unnecessary shutdown times of the air conditioner under special working conditions, and improving the operation reliability and energy efficiency performance of the air conditioning system.

Description

Technical Field

[0001] This application relates to the field of air conditioning technology, and in particular to an air conditioner. Background Technology

[0002] Currently, the common heat dissipation methods for the electrical box in multi-split air conditioners are air cooling and refrigerant cooling. Refrigerant cooling is more effective, but the problem of condensation in the electrical box is difficult to solve. In special cases, the refrigerant pressure and temperature in the refrigerant heat dissipation pipes may be low. To solve the problem of condensation in the electrical box caused by low refrigerant heat dissipation temperature, the refrigerant temperature of the refrigerant heat dissipation module is generally monitored. Existing technology shuts down the air conditioning system when the inlet temperature of the refrigerant heat dissipation module is lower than the dew point temperature of the surrounding air, i.e., when there is a risk of condensation in the electrical box. If shutdowns due to low refrigerant heat dissipation temperature occur frequently, the air conditioning system will trigger an alarm, and the unit cannot be restarted, requiring repair by a service engineer. This control method can prevent damage to the circuit board due to condensation in the electrical box; however, it is prone to air conditioning shutdowns and alarms, failing to meet users' continuous cooling and heating needs, resulting in a poor user experience. Therefore, how to control the electrical box temperature within a reasonable range to achieve high efficiency and prevent condensation is an urgent problem to be solved. Summary of the Invention

[0003] This application provides an air conditioner that can control the temperature of the electrical box within a reasonable range, thereby achieving heat dissipation and preventing condensation in the electrical box.

[0004] The first aspect of this application provides an air conditioner, including: Indoor unit, An outdoor unit, connected to the indoor unit, the outdoor unit comprising: compressor; The outdoor heat exchanger is configured to exchange heat with the outdoor air via refrigerant; Electrical modules, including: An electrical box, containing multiple electrical components; A refrigerant radiator is installed on the electrical box, and the refrigerant radiator is used to dissipate heat from the electrical box through refrigerant. An outdoor expansion valve is connected in series with the refrigerant radiator, and the outdoor expansion valve is used to control the flow rate of refrigerant entering the refrigerant radiator; The sensor module includes: A first temperature sensor is used to obtain the electrical box temperature of the electrical box; The second temperature sensor is used to obtain the outdoor ambient temperature. The third temperature sensor is used to obtain the refrigerant inlet temperature at the inlet of the refrigerant radiator. A controller, connected to the outdoor unit and the indoor unit, is configured to: A first temperature and a second temperature are obtained. The first temperature is the electrical box temperature obtained by the first temperature sensor. The second temperature is the upper limit temperature of the electrical box, a target temperature, or the outdoor ambient temperature obtained by the second temperature sensor. The target temperature is less than the upper limit temperature of the electrical box and falls within a preset temperature range based on the upper limit temperature of the electrical box. Alternatively, the first temperature is the refrigerant inlet temperature at the refrigerant radiator inlet obtained by the third temperature sensor, and the second temperature is the outdoor ambient temperature. The opening degree of the outdoor expansion valve is controlled based on the first temperature and the second temperature.

[0005] The aforementioned technical solution, in terms of the air conditioner's structure, constructs an independent and precise electrical box heat dissipation bypass system by installing a refrigerant radiator on the electrical box and connecting an outdoor expansion valve, used to control the refrigerant flow into the radiator, in series with it. Simultaneously, multiple temperature sensors installed in the sensor module obtain the electrical box temperature, outdoor ambient temperature, and refrigerant inlet temperature. This structural foundation, combined with the controller's control logic, allows it to adjust the opening of the outdoor expansion valve based on the relationship between a first temperature (electrical box temperature or refrigerant inlet temperature) and a second temperature (electrical box upper limit temperature, target temperature, or outdoor ambient temperature), effectively overcoming the problem in existing refrigerant heat dissipation systems that cannot simultaneously achieve high-temperature, high-efficiency heat dissipation and anti-condensation. Specifically, during air conditioner operation, if the relationship between the first and second temperatures indicates a potential risk of condensation, or if the electrical box temperature is too high or too low, the controller can adjust the opening of the outdoor expansion valve to control the refrigerant flow within the radiator, thereby precisely maintaining the radiator surface temperature within a safe range not lower than the ambient air dew point temperature. Active anti-condensation control not only avoids the risk of short circuits and burnout of electrical components due to long-term condensation accumulation in the electrical box, but also avoids the crude control method in existing technologies that directly shuts down the entire unit based solely on detecting condensation risk. Therefore, this application embodiment effectively reduces the number of unnecessary shutdowns of the air conditioner under special operating conditions while ensuring electrical safety, lowering the risk of user complaints about frequent start-stop cycles, thereby improving the operational reliability and energy efficiency of the air conditioning system.

[0006] In some embodiments, the first temperature is the temperature of the first electrical box or the refrigerant inlet temperature, and the second temperature is the outdoor ambient temperature. The controller is configured to control the opening degree of the outdoor expansion valve based on the first temperature and the second temperature, including: When the outdoor ambient temperature is greater than the first temperature and the difference between the outdoor ambient temperature and the first temperature is greater than or equal to a first threshold, the opening degree of the outdoor expansion valve is reduced.

[0007] The above technical solution establishes a dynamic anti-condensation judgment by comparing a first temperature (electrical box temperature or refrigerant inlet temperature) with a second temperature (outdoor ambient temperature), thereby controlling the adjustment of the outdoor expansion valve 15. During actual air conditioning operation, the controller can obtain the numerical relationship between the first temperature and the outdoor ambient temperature. When the outdoor ambient temperature is greater than the first temperature, and the temperature difference between the two is greater than or equal to a preset first threshold, the controller reduces the opening of the outdoor expansion valve. Since the outdoor ambient temperature represents the dry-bulb temperature of the air surrounding the outdoor heat exchanger, when the ambient temperature is higher than the refrigerant temperature inside the refrigerant radiator, it indicates that the radiator pipe wall is in an extremely low temperature state, making it very easy for moisture in the surrounding air to condense into dew on its surface. At this time, by actively reducing the opening of the outdoor expansion valve connected in series with the refrigerant radiator, the refrigerant flow through the refrigerant radiator can be effectively reduced, maintaining the surface temperature of the electrical box within a relatively high and safe range. Based on the mechanism of dynamic adjustment of ambient temperature, the electrical components are not only effectively prevented from being damaged by short circuits due to condensation in the electrical box, but also the refrigerant bypass loss in the heat dissipation branch is minimized. This allows more refrigerant to focus on serving the indoor heat exchange needs, thereby further improving the operating efficiency of the air conditioner while ensuring the safety of the electrical box, and achieving a high-efficiency unity of safety protection and energy saving.

[0008] In some embodiments, the controller is configured to: reduce the opening of the outdoor expansion valve, including: The outdoor expansion valve is controlled to decrease by a first multiple of its current opening, where the current opening is the opening of the outdoor expansion valve before adjustment.

[0009] The above technical solution further refines the control logic for reducing the opening degree of the outdoor expansion valve when anti-condensation is triggered. In conventional multi-split air conditioning anti-condensation control, when the refrigerant radiator surface temperature is determined to be too low, direct shutdown is often used. This rigid change often leads to a sudden and violent fluctuation in the high-pressure side of the system, which not only easily triggers the compressor discharge pressure over-extension alarm but also causes frequent start-stop of the entire unit, severely deteriorating the user experience. However, the embodiment of this application uses a first multiple of the current opening degree for reduction control, so that the opening degree change of the outdoor expansion valve gradually decreases, avoiding violent fluctuations in refrigerant flow and system pressure during adjustment, ensuring a smooth transition of system operating pressure, effectively reducing the risk of unnecessary shutdowns triggered by control abrupt changes, and improving the reliability of air conditioning operation.

[0010] In some embodiments, the first temperature is the temperature of the first electrical box, and the second temperature is the target temperature. The controller is configured to control the opening degree of the outdoor expansion valve based on the first temperature and the second temperature, including: If the target temperature is greater than the temperature of the first electrical box, and the difference between the target temperature and the temperature of the first electrical box is greater than a second threshold, the opening of the outdoor expansion valve is reduced. When the temperature of the first electrical box is greater than the target temperature, and the difference between the temperature of the first electrical box and the target temperature is greater than a third threshold, the opening of the outdoor expansion valve is increased.

[0011] The above technical solution compares the temperature difference between the first electrical box and the target temperature. When the controller determines that the target temperature is greater than the first electrical box temperature, and the difference between the two is greater than a second threshold (indicating that the electrical box temperature is within a safe range but significantly low), the controller will reduce the opening of the outdoor expansion valve to limit the refrigerant flow. This effectively prevents the refrigerant radiator from overcooling, avoiding the waste of refrigerant energy caused by excessive heat dissipation. Valuable refrigerant is then used for heat exchange in the main circuit to improve overall unit efficiency. Furthermore, it proactively avoids the risk of condensation on the pipes caused by excessively low radiator surface temperature, achieving early intervention for anti-condensation protection. Simultaneously, when the controller determines that the first electrical box temperature is greater than the target temperature, and the difference between the two is greater than a third threshold (indicating that the electrical box temperature is approaching its upper limit and there is a risk of overheating), the controller will immediately increase the opening of the outdoor expansion valve. By increasing the refrigerant flow in the refrigerant radiator, the heat exchange capacity between the refrigerant and the electrical box can be rapidly improved, quickly removing heat from the electrical box and bringing the temperature back to near the target value. This not only ensures that the control board does not reduce its frequency due to overheating under extreme high-load conditions, but also prevents the equipment from operating at the edge of extreme temperature for a long time by setting a target temperature, effectively extending the service life of the internal components of the electrical module.

[0012] In some embodiments, the controller is further configured to: When the temperature of the first electrical box is greater than or equal to the difference between the target temperature and the second threshold, and the temperature of the first electrical box is less than or equal to the sum of the target temperature and the third threshold, the opening of the outdoor expansion valve remains unchanged.

[0013] In the above technical solution, when the temperature of the first electrical box falls within the tolerance range of the preset range (second threshold and third threshold) on both sides of the target temperature, the controller judges that the current refrigerant heat dissipation branch flow is in a relatively ideal balance state. Therefore, the opening of the outdoor expansion valve remains unchanged. This operation can provide sufficient response buffer time for the air conditioning system under transitional conditions, avoid control disorder caused by over-adjustment, and ensure that the compressor and the outdoor expansion valve can operate smoothly and continuously.

[0014] In some embodiments, the controller is configured to: reduce the opening of the outdoor expansion valve, including: The opening degree of the outdoor expansion valve is reduced according to the first preset opening degree value.

[0015] In the aforementioned technical solution, when the controller determines that the target temperature is greater than the temperature of the first electrical box, and the difference between the two exceeds a preset second threshold (i.e., the current temperature of the electrical box is significantly lower than the ideal heat dissipation equilibrium point), the controller does not blindly reduce the opening degree. Instead, it reduces the opening degree of the outdoor expansion valve by an absolute value according to a preset first opening degree value. This fixed-step opening degree reduction strategy allows for highly certain and fully controlled mechanical intervention when facing the risk of excessively low electrical box temperature. This avoids sudden reductions in refrigerant flow, severe fluctuations in system pressure, and potential system-wide alarm shutdowns caused by abrupt valve opening changes, thus improving the operational safety and signal response certainty of the air conditioner during the anti-condensation intervention phase.

[0016] In some embodiments, the controller is configured to increase the opening of the outdoor expansion valve, including: Increase the opening of the expansion valve according to the second preset opening value.

[0017] In the aforementioned technical solution, if the controller determines that the electrical box temperature is higher than the target temperature and the difference between the two exceeds a set third threshold, it means that high-power components such as the drive module inside the electrical box have accumulated considerable heat and are at the overheating boundary requiring immediate intervention. At this point, the controller increases the opening of the outdoor expansion valve in increments of a fixed step, according to a preset second opening value. This fixed-step opening increase strategy ensures that, when facing the risk of high temperatures, the refrigerant flow can be increased in a deterministic manner, increasing the refrigerant flow through the refrigerant radiator. This significantly improves the heat exchange efficiency between the radiator and the electrical box at the physical level, quickly removing the accumulated heat and preventing further temperature increases in the electrical box, thus enhancing the operational reliability of the air conditioner.

[0018] In some embodiments, the first temperature is the temperature of the first electrical box, and the second temperature is the upper limit temperature of the electrical box. The controller is configured to control the opening degree of the outdoor expansion valve based on the first temperature and the second temperature, including: When the temperature of the first electrical box is less than the upper limit temperature of the electrical box, the difference between the upper limit temperature of the electrical box and the temperature of the first electrical box is less than a fourth threshold, and the temperature of the first electrical box is greater than the temperature of the second electrical box, the opening of the outdoor expansion valve is increased by a first degree. The temperature of the second electrical box is obtained by the first temperature sensor before the temperature of the first electrical box is obtained. When the temperature of the first electrical box is less than the upper limit temperature of the electrical box, the difference between the upper limit temperature of the electrical box and the temperature of the first electrical box is less than a fifth threshold, and the temperature of the first electrical box is greater than the temperature of the second electrical box, the opening degree of the outdoor expansion valve is increased by a second degree, wherein the fifth threshold is less than the fourth threshold, and the second degree is greater than the first degree.

[0019] The aforementioned technical solution employs a tiered electronic expansion valve opening adjustment in an emergency situation where the electrical box temperature approaches its upper limit and remains consistently higher than the previous temperature (indicating an upward trend). Based on the proximity to the upper limit temperature, different valve opening increases are executed. By introducing a fourth and fifth threshold, and combining this with a comparison between the current first electrical box temperature and the previous second electrical box temperature, it is determined that the electrical box is in a state of rapid heat accumulation. When the controller determines that although the first electrical box temperature has not yet reached its upper limit, the difference between the two has narrowed to within the fourth threshold, and the current temperature continues to be higher than the previous temperature, it identifies the area as being in the initial danger zone of heat accumulation. Based on this, the controller performs a relatively gentle intervention, increasing the outdoor expansion valve opening by a first degree. This action increases refrigerant flow to provide effective basic heat dissipation while avoiding excessive intervention that could cause pressure fluctuations in the early stages of temperature rise. Furthermore, a fifth threshold (i.e., the electrical box temperature is closer to the upper limit) is further set, lower than the fourth threshold. When the controller determines that the current temperature is approaching the fifth threshold and still shows a trend of continuous temperature increase, it judges that the heat dissipation demand is relatively urgent. The controller then takes a more significant intervention measure, greatly increasing the opening of the outdoor expansion valve to a second degree (and this second degree is greater than the first degree). This graded strategy based on proximity to the safety line ensures that the air conditioner can take appropriate emergency measures when facing different degrees of thermal crisis, guaranteeing the continuity, stability, and efficiency of air conditioning cooling or heating, greatly reducing the risk of user complaints, and comprehensively improving the long-term operational reliability of the entire unit under extreme conditions.

[0020] In some embodiments, the first opening is a second multiple of the current opening of the outdoor expansion valve, the current opening being the opening of the outdoor expansion valve before the opening is adjusted; The second opening degree is a multiple of the current opening degree of the outdoor expansion valve, where the third multiple is greater than the second multiple.

[0021] The above technical solution further refines the adjustment method of the outdoor expansion valve's opening. By setting the first and second openings to the second and third multiples of the current opening, respectively, and ensuring that the third multiple is greater than the second multiple, the controller can achieve dynamic multiplication adjustment when responding to different levels of overheating risk. This control strategy, based on proportional amplification of the current actual opening, ensures that each increase in refrigerant flow is appropriate: when the temperature is far from the upper limit, a smaller amplification factor (second multiple) is used for gentle compensation to avoid excessive refrigerant bypass leading to a decrease in the main circulation capacity; while when the temperature approaches the limit and is still rising, a larger amplification factor (third multiple) is used to rapidly inject a large amount of refrigerant for cooling. This effectively avoids the problems of insufficient response when the opening is large and excessive force when the opening is small due to fixed step adjustment, and significantly enhances the outdoor expansion valve's anti-disturbance capability and cooling efficiency when facing sudden temperature rises. While ensuring electrical control safety, it effectively guarantees the stability and efficiency of the entire unit's refrigerant circulation.

[0022] In some embodiments, the outdoor unit further includes: A subcooler is used to cool the refrigerant supplied from the outdoor heat exchanger, so as to deliver the cooled refrigerant to the indoor unit; wherein, The electrical module and the outdoor expansion valve are connected in parallel on the refrigerant passage between the subcooler and the heat exchanger for transferring refrigerant.

[0023] The above technical solution optimizes the energy distribution between refrigerant heat dissipation and the main circulation at the system structure level by connecting a heat dissipation branch consisting of an electrical module and an outdoor expansion valve in series in parallel on the main refrigerant path used for refrigerant transfer between the subcooler and the outdoor heat exchanger. In this parallel structure, the subcooler mainly performs the function of deep subcooling the high-pressure liquid refrigerant flowing out of the outdoor heat exchanger to ensure that the refrigerant delivered to the indoor unit has good liquid purity and guarantees long-distance cooling effect; while the heat dissipation branch connected in parallel on the main path, through precise control of the opening of the outdoor expansion valve, allows the refrigerant to undergo sufficient throttling and pressure reduction and heat absorption when entering the refrigerant radiator on the electrical box, thereby efficiently achieving temperature control for the electrical box. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of an air conditioner; Figure 2 This is a schematic diagram illustrating heat dissipation of the electrical box via a refrigerant radiator, as proposed in an embodiment of this application. Figure 3 This is a schematic diagram of another air conditioner proposed in the embodiments of this application; Figure 4 This is a flowchart illustrating a control method executed by a controller in an air conditioner according to an embodiment of this application.

[0025] Figure 5 This is a schematic diagram of a process for controlling the opening degree of an outdoor expansion valve in an air conditioner according to an embodiment of this application.

[0026] Figure 6 This is a schematic diagram illustrating another process for controlling the opening degree of the outdoor expansion valve in an air conditioner according to an embodiment of this application. Detailed Implementation

[0027] The technical solutions in the embodiments of this application will now be described with reference to the accompanying drawings.

[0028] To facilitate a clear description of the technical solutions in the embodiments of this application, the terms "first" and "second" are used in the embodiments of this application to distinguish identical or similar items with essentially the same function and effect. For example, "first instruction" and "second instruction" are used to distinguish different user instructions and do not limit their order. Those skilled in the art will understand that the terms "first" and "second" do not limit the quantity or execution order, and the terms "first" and "second" are not necessarily different.

[0029] It should be noted that in the embodiments of this application, the words "exemplarily" or "for example" are used to indicate examples, illustrations, or explanations. Any embodiment or design scheme described as "exemplarily" or "for example" in the embodiments of this application should not be construed as being more preferred or advantageous than other embodiments or design schemes. Specifically, the use of the words "exemplarily" or "for example" is intended to present the relevant concepts in a specific manner.

[0030] Furthermore, "at least one" refers to one or more, while "more than one" refers to two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can mean: A alone, A and B simultaneously, or B alone, where A and B can be singular or plural. The character " / " generally indicates that the preceding and following related objects are in an "or" relationship. "At least one of the following" or similar expressions refer to any combination of these items, including any combination of single or plural items. For example, at least one of a, b, and c can mean: a, or b, or c, or a and b, or a and c, or b and c, or a, b, and c, where a, b, and c can be single or multiple.

[0031] It should be noted that, in the embodiments of this application, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0032] Currently, the common heat dissipation methods for the electrical box in multi-split air conditioners are air cooling and refrigerant cooling. Refrigerant cooling is more effective, but condensation in the electrical box is more difficult to solve. In certain situations, the refrigerant pressure and temperature in the refrigerant heat dissipation pipes may be low. For example, in long piping systems with low refrigerant levels, the pressure loss from the long piping is significant, resulting in lower refrigerant pressure and temperature in the heat dissipation pipes. Alternatively, if the expansion valve is blocked, the refrigerant will experience a throttling effect when the unit is running in cooling mode, leading to lower refrigerant pressure and temperature in the heat dissipation pipes. This low temperature is conducted to the inverter drive module through the heat sink. When the module temperature is lower than the dew point temperature of the surrounding air, condensation will occur in the drive module, potentially causing short circuits in the electrical components and damaging the drive module. To address the issue of condensation in the electrical box caused by low refrigerant heat dissipation temperature, the refrigerant temperature of the refrigerant heat dissipation module is typically monitored. Current technology shuts down the air conditioning system when the inlet temperature of the refrigerant heat dissipation module is lower than the dew point temperature of the surrounding air, indicating a risk of condensation in the electrical box. If shutdowns due to low refrigerant heat dissipation temperature occur frequently, the air conditioning system will trigger an alarm, and the unit will be unable to restart, requiring repair by a service engineer.

[0033] To balance the heat dissipation effect of refrigerant and prevent refrigerant condensation, existing heat dissipation technologies place the refrigerant radiator at the condenser outlet, between the outdoor heat exchanger and the subcooler. The circulation diagram is shown below. Figure 1 As shown, it includes: compressor 1, oil separator 2, exhaust check valve 3, bypass solenoid valve 4, four-way valve 5, oil return capillary tube 6, gas-liquid separator 7, outdoor expansion valve 8, outdoor expansion valve 11, subcooler 9, refrigerant radiator 10, outdoor heat exchanger 12, indoor heat exchanger 13, and indoor expansion valve 14.

[0034] Among them, compressor 1 is responsible for compressing low-pressure refrigerant gas into high-temperature and high-pressure gas to drive the entire cycle.

[0035] The oil separator 2 is located at the compressor discharge port. It separates the refrigeration oil discharged from the compressor from the high-pressure refrigerant gas. The separated refrigeration oil is returned to the compressor through the oil return device to prevent damage due to oil shortage.

[0036] The exhaust check valve 3 allows high-pressure gas to flow unidirectionally to the four-way valve, preventing high-pressure gas from flowing back into the compressor when the four-way valve switches.

[0037] The bypass solenoid valve 4 is used to regulate system pressure or to bypass hot gas. Under specific operating conditions, it directly bypasses high-pressure exhaust to the low-pressure side to prevent overload during winter startup or to perform defrosting.

[0038] The four-way valve 5 switches between cooling (heat absorption by the indoor heat exchanger) and heating (heat release by the indoor heat exchanger) modes by changing the direction of refrigerant flow.

[0039] The oil return capillary tube 6 connects the high-pressure side and the low-pressure side, and uses the pressure difference to slowly and quantitatively send the refrigeration oil separated in the oil separator back to the compressor suction pipe (gas-liquid separator 7).

[0040] The gas-liquid separator 7 is located before the compressor's suction port. It separates the incompletely evaporated liquid refrigerant from the gaseous refrigerant, preventing liquid slugging (liquid refrigerant directly entering the compressor cylinder and damaging the compressor), and temporarily stores excess refrigerant.

[0041] The outdoor expansion valve 8 acts as the main throttling component during cooling and as an auxiliary subcooling throttling component during heating.

[0042] The subcooler 9 may include a plate heat exchanger or a coaxial heat exchanger for cooling the refrigerant supplied from the outdoor heat exchanger, so that the cooled refrigerant can be delivered to the indoor unit. A portion of the refrigerant exchanges heat with the main refrigerant here, further cooling the main refrigerant and thus improving cooling efficiency.

[0043] like Figure 2 As shown, Figure 2 This is a schematic diagram of heat dissipation for the electrical box via a refrigerant radiator 10. The refrigerant radiator 10 is installed inside the electrical box and, exemplarily, can cover the drive module / control board. It absorbs the heat generated by the drive module and prevents the electrical box from overheating.

[0044] The outdoor expansion valve 11 is used to control the flow of refrigerant into the refrigerant radiator.

[0045] The outdoor heat exchanger 12 acts as a condenser to dissipate heat to the outside when the air conditioner is in cooling mode, and acts as an evaporator to absorb heat from the outside when the air conditioner is in heating mode.

[0046] The indoor heat exchanger 13 is located in the indoor unit. It acts as an evaporator to absorb indoor heat during cooling and as a condenser to dissipate heat into the room during heating.

[0047] The indoor expansion valve 14 is located in the indoor unit and is responsible for throttling and reducing the pressure of the refrigerant entering the indoor heat exchanger.

[0048] Refrigerant cooling uses the condensed refrigerant in the condenser to dissipate heat from the electrical box. Under high-temperature conditions, the temperature of the condensed refrigerant is high, exceeding the ambient temperature. The cooling capacity of the refrigerant is insufficient to reduce the heat generated by the drive module of the electrical box, causing the compressor to reduce its frequency due to excessively high drive cooling temperature. Even when the compressor reduces to the lowest frequency, the refrigerant pressure remains high, the unit load is large, and the heat generated by the drive module is significant. Control methods cannot reduce the drive cooling temperature, leading the unit to shut down to address the high drive temperature issue. Frequent unit shutdowns result in poor cooling performance.

[0049] According to existing technology, in order to prevent condensation problems in refrigerant heat dissipation, the unit will be shut down or alarmed when the operating parameters meet the following conditions.

[0050] Control conditions: Ta–Tsc≥T1℃ for A minutes, and Tfin-Ta≤T2℃ for B minutes.

[0051] Control measures: 1. The unit will shut down if the above control conditions are met. 2. If n shutdowns occur within 1 hour, the unit will trigger an alarm.

[0052] Where Ta is the outdoor unit ambient temperature, Tsc is the refrigerant radiator inlet temperature, and Tfin is the electrical box temperature. For example, the values ​​of Ta, Tsc, T1, A, Tfin, Ta, T2, and B can be T1=0~10, T2=0~10, A=0~10, and B=0~10.

[0053] Existing technologies can effectively prevent damage to electrical components in the electrical box due to condensation by shutting down or triggering an alarm when control conditions are met. However, under certain special operating conditions, air conditioning shutdown and alarm issues may occur, failing to meet users' continuous cooling and heating needs, reducing user experience, and increasing the risk of user complaints.

[0054] Therefore, controlling the temperature of the electrical box within a reasonable range and solving the problem of refrigerant condensation is an urgent issue to be addressed.

[0055] In view of this, this application proposes an air conditioner, including: an indoor unit, an outdoor unit connected to the indoor unit, the outdoor unit including: a compressor; an outdoor heat exchanger 12 configured to exchange heat with outdoor air; an electrical module including: an electrical box housing multiple electrical components; a refrigerant radiator 10 disposed on the electrical box, the refrigerant radiator being used to dissipate heat from the electrical box via refrigerant; an outdoor expansion valve 15 connected in series with the refrigerant radiator, the outdoor expansion valve being used to control the flow rate of refrigerant entering the refrigerant radiator; and a sensor module including: a first temperature sensor for acquiring the electrical box temperature; a second temperature sensor for acquiring the outdoor ambient temperature; and a third temperature sensor. The system is used to obtain the refrigerant inlet temperature at the refrigerant radiator inlet; a controller, connected to the outdoor unit and the indoor unit, is configured to: obtain a first temperature and a second temperature, wherein the first temperature is the first electrical box temperature obtained by a first temperature sensor, and the second temperature is the upper limit temperature of the electrical box, a target temperature, or the outdoor ambient temperature obtained by a second temperature sensor, wherein the target temperature is less than the upper limit temperature of the electrical box and falls within a preset temperature range based on the upper limit temperature of the electrical box; or, the first temperature is the refrigerant inlet temperature at the refrigerant radiator inlet obtained by a third temperature sensor and the second temperature is the outdoor ambient temperature; and control the opening degree of the outdoor expansion valve according to the first and second temperatures. The above technical solution, in the structure of the air conditioner, constructs an independent and precise electrical box heat dissipation bypass system by setting a refrigerant radiator on the electrical box and connecting the outdoor expansion valve for controlling the refrigerant flow into the refrigerant radiator in series with the refrigerant radiator. Simultaneously, multiple temperature sensors installed in the sensor module are used to obtain the electrical box temperature, the outdoor ambient temperature, and the refrigerant inlet temperature. This structural foundation, combined with the controller's control logic, enables it to adjust the opening of the outdoor expansion valve based on the relationship between a first temperature (electrical box temperature or refrigerant inlet temperature) and a second temperature (electrical box upper limit temperature, target temperature, or outdoor ambient temperature). This effectively overcomes the problem in existing refrigerant heat dissipation systems that cannot simultaneously achieve high-temperature, high-efficiency heat dissipation and anti-condensation. Specifically, during air conditioner operation, if the relationship between the first and second temperatures indicates a potential risk of condensation, or if the electrical box temperature is too high or too low, the controller can adjust the opening of the outdoor expansion valve to control the refrigerant flow within the refrigerant radiator. This precisely maintains the refrigerant radiator surface temperature within a safe range not lower than the ambient air dew point temperature. This proactive anti-condensation control not only avoids the risk of short-circuiting and burning out electrical components due to long-term condensation accumulation in the electrical box, but also avoids the crude control method of directly shutting down the entire unit based solely on detecting a condensation risk, as is common in existing technologies. Therefore, this application embodiment effectively reduces the number of unnecessary shutdowns of the air conditioner under special operating conditions while ensuring electrical safety, reduces the risk of user complaints about frequent start-stop of the air conditioner, and thus improves the operational reliability and energy efficiency of the air conditioning system.

[0056] To make the objectives and technical solutions of the embodiments of this application clearer and more intuitive, the air conditioner disclosed in the embodiments of this application will be described in detail below with reference to the accompanying drawings.

[0057] like Figure 3 As shown: The air conditioner proposed in this application embodiment includes: an indoor unit, including: an indoor heat exchanger 13 and an indoor expansion valve 14; and an outdoor unit, including: a compressor 1, an oil separator 2, an exhaust check valve 3, a bypass solenoid valve 4, a four-way valve 5, an oil return capillary tube 6, a gas-liquid separator 7, an outdoor expansion valve 8, an outdoor expansion valve 11, a subcooler 9, a refrigerant radiator 10, an outdoor heat exchanger 12, and an outdoor expansion valve 15.

[0058] It should be understood that, Figure 1 The article has already described some of the structure of the air conditioner, so we will not repeat it here.

[0059] The refrigerant radiator is located in the electrical module, which also includes an electrical box (not shown in the figure). The refrigerant radiator 10 is mounted on the electrical box and is used to dissipate heat from the electrical box through refrigerant.

[0060] For example, the electrical box can be an outdoor electrical box, which may also include an electrical control motherboard, on which various microprocessors and chips are integrated for calculation and control. It typically also houses multiple heat-generating components, such as capacitors and reactors.

[0061] For example, outdoor expansion valve 15 is connected in parallel with outdoor expansion valve 11, and the opening degree of outdoor expansion valve 11 can control the outlet superheat of outdoor heat exchanger 12.

[0062] For example, the initial opening degree of the outdoor expansion valve 11 can be: EVO_start=Kta×Ktd×Kch×Hzstart.

[0063] Where Kta is the ambient temperature coefficient, its value ranges from 1 to 5, and the higher the outdoor ambient temperature Ta, the higher Kta is; Ktd is the compressor discharge temperature coefficient, its value ranges from 1 to 1.5, and the higher the discharge temperature Td, the higher Ktd is; Kch is the start-up scenario coefficient, the Kch coefficient is different for different start-up states. For states such as sleep start, cooling to heating start, and defrost start, in order to reduce the amount of liquid returning to the evaporator, Kch is smaller, with a value range of 0.3 to 0.8. For operating conditions such as hot start, where the amount of liquid returning is small, in order to accelerate the heating speed, Kch is larger, with a value range of 1 to 1.5. Hzstart is the compressor initial frequency during heating start, with a value range of 30 to 100.

[0064] In some embodiments, in heating mode, the outlet superheat of the outdoor evaporator (outdoor heat exchanger 12) can be controlled by controlling the opening of the outdoor expansion valve 11. For example, the target range of the outlet superheat can be 3 to 8.

[0065] When TsSH < 3, to prevent refrigerant backflow from the compressor, the opening of the outdoor expansion valve 11 (EVO) is reduced. TsSH < 3 means that the refrigerant has barely vaporized in the outdoor heat exchanger, and the refrigerant leaving the heat exchanger still contains a large amount of liquid. At this point, the system is on the verge of extremely dangerous "refrigerant backflow." If low-temperature gas carrying a large amount of liquid refrigerant is directly drawn into the compressor, it will cause the lubricating oil to be diluted, and liquid slugging (hydraulic shock) to occur inside the cylinder. In severe cases, it can directly rupture the compressor cylinder. The controller must immediately reduce the opening of the outdoor expansion valve 11 (EVO). By reducing the refrigerant flow through the expansion valve, the amount of liquid refrigerant supplied to the outdoor heat exchanger is forcibly reduced, allowing the remaining refrigerant sufficient time to absorb heat and evaporate completely within the heat exchanger. This quickly brings TsSH back to a safe range, preserving the compressor's lifespan.

[0066] When 8 ≥ TsSH ≥ 3, EVO remains constant; the outlet superheat of the outdoor evaporator is between 3°C and 8°C, and the system has neither the risk of liquid slugging nor severe refrigerant overheating. This is the ideal dead zone for the outdoor evaporator. A superheat of 3°C is sufficient to ensure that the compressor draws in purely superheated gas (absolutely safe), while the upper limit of 8°C ensures that most of the outdoor heat exchanger area is used for refrigerant phase change heat absorption (high efficiency), without excessive gas overheating and waste.

[0067] Within this range, the system determines that the current flow rate is sufficient to meet the heating demand. To avoid fluctuations in system pressure and refrigerant flow caused by frequent adjustments to the expansion valve, the EVO opening remains unchanged. The controller relies on the system's own physical inertia to absorb minor fluctuations.

[0068] When TsSH > 8 and the compressor discharge superheat TdSH ≥ 30, increase EVO. Both conditions being met simultaneously means that not only is the evaporator outlet severely overheated, but the compressor discharge temperature has also soared to a dangerously high level. This typically occurs in extreme cold weather, severe frosting on the outdoor heat exchanger, or significant refrigerant leakage in the system.

[0069] A TsSH > 8℃ indicates that a large portion of the upper area of ​​the outdoor heat exchanger is dry-burning (no liquid refrigerant can evaporate, resulting in wasted space). Simultaneously, a TdSH ≥ 30℃ (discharge temperature minus condensation temperature) indicates excessive compressor discharge temperature rise, which accelerates refrigerant oil carbonization and coking, easily leading to compressor seizure or burnout due to lack of lubrication. These two conditions act as a double warning, confirming that the system is not currently experiencing "localized overheating," but rather "overall refrigerant shortage."

[0070] At this point, the controller must decisively activate the large EVO. By rapidly increasing the supply of liquid refrigerant, more refrigerant enters the outdoor heat exchanger to participate in evaporation and heat absorption. This not only directly reduces the superheat (TsSH) at the evaporator outlet, but more importantly, the replenishment of liquid effectively suppresses the continued rise in the compressor discharge temperature, thus ensuring that the compressor is not burned out by high temperature under extremely cold / low refrigerant conditions.

[0071] An outdoor expansion valve 15 is connected in series with a refrigerant radiator and is used to control the flow rate of refrigerant entering the refrigerant radiator. For example, the outdoor expansion valve 15 can be an electronic expansion valve.

[0072] For example, the initial opening degree of the outdoor expansion valve 15 can be: EVC_start = K1 × EVO_start.

[0073] K1 is a proportionality coefficient, which is the ratio of the initial opening sizes of EVC and EVO. It controls the proportion of refrigerant flow through which the refrigerant dissipates heat, ensuring the minimum flow required for heat dissipation, but preventing excessive opening that could cause liquid return to the evaporator. During the initial adjustment of the outdoor expansion valve 15, adjustments can be made based on the initial opening size.

[0074] In addition, the air conditioner may also include a sensor module and a controller (not shown in the figure). The sensor module includes a first temperature sensor for acquiring the electrical box temperature; a second temperature sensor for acquiring the outdoor ambient temperature; and a third temperature sensor for acquiring the refrigerant inlet temperature at the refrigerant radiator inlet.

[0075] The controller, located in the electrical box, has the core function of comprehensively processing the operating parameters collected by the sensor modules and globally coordinating the various actuators of the system. During operation, the controller establishes a dynamic balancing algorithm by comparing multi-dimensional data such as the electrical box temperature rise, ambient temperature and humidity, and the inlet temperature of the refrigerant heat dissipation circuit in real time. This balances the heat dissipation efficiency of the drive modules with the electrical safety of the system. It can adjust the throttling degree of the refrigerant heat dissipation branch according to changes in heat load, ensuring that the heat generated by the power module is dissipated in a timely manner while also sensitively detecting the potential condensation risk caused by excessively low refrigerant temperatures, thus finding the optimal solution between heat dissipation requirements and moisture protection. Simultaneously, the controller also undertakes the task of coordinating the main circulation of the system. It automatically switches control strategies according to the operating mode, ensuring stable, efficient, and safe operation of the air conditioning system under varying conditions by coordinating the compressor frequency, the status of the four-way valve, and the opening degree of each expansion valve.

[0076] In some embodiments, the outdoor unit further includes: Subcooler 9 is used to cool the refrigerant supplied from the outdoor heat exchanger, so that the cooled refrigerant can be delivered to the indoor unit; wherein, An electrical module and an outdoor expansion valve are connected in parallel on the refrigerant passage between the subcooler and the outdoor heat exchanger for transferring refrigerant.

[0077] For example, the refrigerant path mentioned in the above embodiment can be a path that directly connects the subcooler and the outdoor heat exchanger 12. An electrical module and an outdoor expansion valve 15 are connected in parallel on this refrigerant path so that the main circulation is not affected by the refrigerant heat dissipation path during the process of the refrigerant radiator dissipating heat and controlling the temperature of the electrical box.

[0078] When the indoor unit is a water module or a fresh air unit, and the unit is in heating mode, if the inlet water temperature of the water module or the return air temperature of the fresh air unit is low, the refrigerant will condense at a low temperature after entering the indoor unit. After returning to the outdoor unit, the refrigerant will condense again through the subcooler. The lower-temperature refrigerant will then enter the refrigerant radiator and then the outdoor expansion valve 15. The flow rate of refrigerant entering the refrigerant radiator can be controlled by adjusting the opening of the expansion valve 15, thus controlling the temperature of the refrigerant radiator within a reasonable range and avoiding the problem of condensation caused by the refrigerant radiator temperature being lower than the dew point temperature of the outdoor air.

[0079] The above technical solution optimizes the energy distribution between refrigerant heat dissipation and the main circulation at the system structure level by connecting a heat dissipation branch consisting of an electrical module and an outdoor expansion valve in series in parallel on the main refrigerant path used for refrigerant transfer between the subcooler and the outdoor heat exchanger. In this parallel structure, the subcooler mainly performs the function of deep subcooling the high-pressure liquid refrigerant flowing out of the outdoor heat exchanger to ensure that the refrigerant delivered to the indoor unit has good liquid purity and guarantees long-distance cooling effect; while the heat dissipation branch connected in parallel on the main path, through precise control of the opening of the outdoor expansion valve, allows the refrigerant to undergo sufficient throttling and pressure reduction and heat absorption when entering the refrigerant radiator on the electrical box, thereby efficiently achieving temperature control for the electrical box.

[0080] The following control of the outdoor expansion valve 15 refers to the control of the outdoor expansion valve 15 connected in series with the refrigerant radiator.

[0081] Based on the above introduction of the air conditioner, the control method executed by the controller of the air conditioner provided in the embodiments of this application will be described below with reference to the accompanying drawings. Figure 4 As shown, the steps are as follows: Step 401: Obtain a first temperature and a second temperature. The first temperature is the electrical box temperature obtained by the first temperature sensor. The second temperature is the upper limit temperature of the electrical box, the target temperature, or the outdoor ambient temperature obtained by the second temperature sensor. The target temperature is less than the upper limit temperature of the electrical box and falls within a preset temperature range obtained based on the upper limit temperature of the electrical box. Alternatively, the first temperature is the refrigerant inlet temperature at the refrigerant radiator inlet obtained by the third temperature sensor, and the second temperature is the outdoor ambient temperature.

[0082] Obtain a first temperature and a second temperature; control the opening degree of the outdoor expansion valve 15 based on the first and second temperatures. Wherein: The first temperature combination could be: the first temperature is the first electrical box temperature obtained by the first temperature sensor, and the second temperature is the upper limit temperature of the electrical box.

[0083] The second temperature combination could be: the first temperature being the electrical box temperature obtained by the first temperature sensor, and the second temperature being the target temperature.

[0084] The target temperature can be calculated from the upper limit temperature of the electrical box.

[0085] For example, the target temperature can be Tfino = Tfinmax - K2, where Tfinmax is the upper limit temperature of the electrical box, and K2 can be a preset range, such as 5-15. In this case, the preset temperature range in which the target temperature is located can be Tfinmax-5 ≥ Tfino ≥ Tfinmax-15.

[0086] The third temperature combination could be: the first temperature being the electrical box temperature obtained by the first temperature sensor, and the second temperature being the outdoor ambient temperature obtained by the second temperature sensor.

[0087] The fourth temperature combination could be: the first temperature being the refrigerant inlet temperature at the refrigerant radiator inlet obtained by the third temperature sensor, and the second temperature being the outdoor ambient temperature.

[0088] Step 402: Control the opening degree of the outdoor expansion valve 15 according to the first temperature and the second temperature.

[0089] In this step, the outdoor expansion valve 15 is directly connected in series in the path leading to the refrigerant radiator 10. Its opening directly determines the refrigerant flow rate and cooling capacity to the radiator. Therefore, when the system prioritizes cooling, the controller gradually increases the opening of the outdoor expansion valve 15, allowing a larger flow of low-temperature refrigerant to enter the radiator to enhance heat dissipation and suppress overheating of the electrical box. If the controller detects that the difference between the refrigerant temperature at the radiator inlet and the ambient temperature is too large, and the refrigerant surface is prone to reaching the dew point and condensation, the controller needs to reduce the opening of the outdoor expansion valve 15 or enter a protective shutdown state according to a preset program. This ensures that the temperature of the electrical box is maintained within a suitable range, preventing overheating shutdown and condensation due to excessively low temperatures.

[0090] Based on the first and second temperatures, the opening of the outdoor expansion valve is adjusted to obtain the adjusted opening. The adjusted opening is then converted into a motor drive signal and output to the outdoor expansion valve actuator to control the opening of the outdoor expansion valve 15 to increase or decrease.

[0091] The aforementioned technical solution, in terms of the air conditioner's structure, constructs an independent and precise electrical box heat dissipation bypass system by installing a refrigerant radiator on the electrical box and connecting an outdoor expansion valve, used to control the refrigerant flow into the radiator, in series with it. Simultaneously, multiple temperature sensors installed in the sensor module obtain the electrical box temperature, outdoor ambient temperature, and refrigerant inlet temperature. This structural foundation, combined with the controller's control logic, allows it to adjust the opening of the outdoor expansion valve based on the relationship between a first temperature (electrical box temperature or refrigerant inlet temperature) and a second temperature (electrical box upper limit temperature, target temperature, or outdoor ambient temperature), effectively overcoming the problem in existing refrigerant heat dissipation systems that cannot simultaneously achieve high-temperature, high-efficiency heat dissipation and anti-condensation. Specifically, during air conditioner operation, if the relationship between the first and second temperatures indicates a potential risk of condensation, or if the electrical box temperature is too high or too low, the controller can adjust the opening of the outdoor expansion valve to control the refrigerant flow within the radiator, thereby precisely maintaining the radiator surface temperature within a safe range not lower than the ambient air dew point temperature. Active anti-condensation control not only avoids the risk of short circuits and burnout of electrical components due to long-term condensation accumulation in the electrical box, but also avoids the crude control method in existing technologies that directly shuts down the entire unit based solely on detecting condensation risk. Therefore, this application embodiment effectively reduces the number of unnecessary shutdowns of the air conditioner under special operating conditions while ensuring electrical safety, lowering the risk of user complaints about frequent start-stop cycles, thereby improving the operational reliability and energy efficiency of the air conditioning system.

[0092] In some embodiments, the first temperature is the temperature of the first electrical box or the refrigerant inlet temperature, and the second temperature is the outdoor ambient temperature. Based on the first and second temperatures, the opening degree of the outdoor expansion valve 15 is controlled. The control method performed by the controller includes: When the outdoor ambient temperature is greater than the first temperature and the difference between the outdoor ambient temperature and the first temperature is greater than or equal to the first threshold, the opening degree of the outdoor expansion valve 15 is reduced.

[0093] Under the above conditions, there is a risk of condensation in the electrical box. Therefore, the refrigerant flow should be reduced to raise the temperature of the electrical box, thereby reducing the risk of condensation. For example, the refrigerant flow through the refrigerant radiator can be reduced by decreasing the opening of the outdoor expansion valve 15.

[0094] For example, there are two scenarios where the opening of the outdoor expansion valve 15 is reduced when either scenario is met.

[0095] First scenario: When the first temperature is the refrigerant inlet temperature, the outdoor ambient temperature is greater than the refrigerant inlet temperature, and the difference between the outdoor ambient temperature and the refrigerant inlet temperature is greater than or equal to the first threshold, the opening degree of the outdoor expansion valve 15 is reduced.

[0096] Assuming Ta is the outdoor ambient temperature and Tsc is the refrigerant inlet temperature, when the outdoor ambient temperature is greater than the refrigerant inlet temperature, the difference between the outdoor ambient temperature and the refrigerant inlet temperature is obtained and compared with the first threshold.

[0097] If the difference is greater than or equal to the first threshold, reduce the opening of the outdoor expansion valve 15.

[0098] For example: Ta–Tsc ≥ T1℃, where the first threshold is T1. Exemplarily, T1 can be set within the range of 3-8. When Ta–Tsc ≥ T1℃, the outdoor ambient temperature is high, and the refrigerant inlet temperature is low, which may lead to a low temperature in the electrical box and a risk of condensation. The temperature of the electrical box can be increased by raising the refrigerant inlet temperature. Exemplarily, this can be prevented by reducing the opening of the outdoor expansion valve 15, thereby reducing the refrigerant flow through the refrigerant radiator and increasing the refrigerant inlet temperature.

[0099] The second scenario: When the first temperature is the temperature of the first electrical box, the outdoor ambient temperature is greater than the temperature of the first electrical box, and the difference between the outdoor ambient temperature and the temperature of the first electrical box is greater than or equal to the first threshold, the opening degree of the outdoor expansion valve 15 is reduced.

[0100] Assuming Tfin is the temperature of the first electrical box and Ta is the outdoor ambient temperature, when the outdoor ambient temperature is greater than the temperature of the first electrical box, the difference between the outdoor ambient temperature and the temperature of the first electrical box is obtained and compared with a first threshold.

[0101] If the difference is greater than or equal to the first threshold, reduce the opening of the outdoor expansion valve 15.

[0102] For example, if Ta-Tfin ≥ T2℃, where the first threshold is T2, T2 can be set to a range of 3-8 or other ranges. When Ta-Tfin ≥ T2℃, the electrical box temperature is too low. The first electrical box temperature on the surface of the electrical box may be lower than the dew point temperature in the outdoor environment. Moisture in the air may condense on the electrical box's control board, forming condensation, which can lead to circuit corrosion or short circuits. To avoid this, condensation can be prevented by increasing the first electrical box temperature. Increasing the first electrical box temperature reduces the refrigerant flow through the refrigerant radiator, thus reducing the degree of temperature drop and preventing condensation. For example, the opening of the outdoor expansion valve 15 can be reduced, decreasing the refrigerant flow through the refrigerant radiator, thereby increasing the first electrical box temperature and preventing condensation.

[0103] The above technical solution establishes a dynamic anti-condensation judgment by comparing a first temperature (electrical box temperature or refrigerant inlet temperature) with a second temperature (outdoor ambient temperature), thereby controlling the adjustment of the outdoor expansion valve 15. During actual air conditioning operation, the controller can obtain the numerical relationship between the first temperature and the outdoor ambient temperature. When the outdoor ambient temperature is greater than the first temperature, and the temperature difference between the two is greater than or equal to a preset first threshold, the controller reduces the opening of the outdoor expansion valve. Since the outdoor ambient temperature represents the dry-bulb temperature of the air surrounding the outdoor heat exchanger, when the ambient temperature is higher than the refrigerant temperature inside the refrigerant radiator, it indicates that the radiator pipe wall is in an extremely low temperature state, making it very easy for moisture in the surrounding air to condense into dew on its surface. At this time, by actively reducing the opening of the outdoor expansion valve connected in series with the refrigerant radiator, the refrigerant flow through the refrigerant radiator can be effectively reduced, maintaining the surface temperature of the electrical box within a relatively high and safe range. Based on the mechanism of dynamic adjustment of ambient temperature, the electrical components are not only effectively prevented from being damaged by short circuits due to condensation in the electrical box, but also the refrigerant bypass loss in the heat dissipation branch is minimized. This allows more refrigerant to focus on serving the indoor heat exchange needs, thereby further improving the operating efficiency of the air conditioner while ensuring the safety of the electrical box, and achieving a high-efficiency unity of safety protection and energy saving.

[0104] In another embodiment, even if the outdoor ambient temperature is lower than the temperature of the first electrical box, there may still be a risk of condensation if the difference between the two is small. The ultimate goal is that there is no risk of condensation when the temperature of the first electrical box is higher than the outdoor ambient temperature.

[0105] For example, if the outdoor ambient temperature is 30°C and the temperature of the first electrical box is 30.5°C, even though the outdoor ambient temperature is lower than the temperature of the first electrical box, there is still a risk of condensation because the difference between the two is small. Therefore, the opening of the outdoor expansion valve 15 should be reduced to reduce the refrigerant flow through the refrigerant radiator.

[0106] In the above embodiments, the opening degree of the outdoor expansion valve 15 can be reduced by reducing the preset opening degree or by reducing the current opening degree by a multiple thereof. The following embodiments will describe this in detail.

[0107] In some embodiments, when the outdoor ambient temperature is greater than a first temperature and the difference between the outdoor ambient temperature and the first temperature is greater than or equal to a first threshold, the opening degree of the outdoor expansion valve 15 is reduced, and the control method executed by the controller includes: When the outdoor ambient temperature is greater than a first temperature and the difference between the outdoor ambient temperature and the first temperature is greater than or equal to a first threshold, the outdoor expansion valve 15 is controlled to decrease by a first multiple of the current opening degree, which is the opening degree of the outdoor expansion valve 15 before the opening degree was adjusted.

[0108] If the outdoor ambient temperature is greater than the first temperature and the difference between the outdoor ambient temperature and the first temperature is greater than or equal to the first threshold, it is determined that the opening of the outdoor expansion valve 15 needs to be reduced. At this time, the opening of the outdoor expansion valve 15 can be reduced by the following formula.

[0109] For example, EVC(n) = K5 × EVC(n-1).

[0110] Where EVC(n) is the target opening degree that the outdoor expansion valve 15 should perform after this adjustment, and EVC(n-1) is the current opening degree that the outdoor expansion valve 15 is operating at before this adjustment. K5 is a value less than 1, which is the first multiple mentioned in the above embodiment, for example, K5=0.8~1.0.

[0111] When K5=1.0: EVC(n) = EVC(n-1). The valve opening does not change, which means that the system is in a maintenance state. It may have just reached the trigger threshold boundary, and it is sufficient to maintain the status quo.

[0112] When K5=0.8: the expansion valve opening is directly reduced to 80% of the current opening. This is a rapid convergence protection action, used in situations where the temperature difference is extremely large and the risk of condensation is extremely obvious, requiring a rapid cut-off of the refrigerant flow.

[0113] The above technical solution further refines the control logic for reducing the opening degree of the outdoor expansion valve when anti-condensation is triggered. In conventional multi-split air conditioning anti-condensation control, when the refrigerant radiator surface temperature is determined to be too low, direct shutdown is often used. This rigid change often leads to a sudden and violent fluctuation in the high-pressure side of the system, which not only easily triggers the compressor discharge pressure over-extension alarm but also causes frequent start-stop of the entire unit, severely deteriorating the user experience. However, the embodiment of this application uses a first multiple of the current opening degree for reduction control, so that the opening degree change of the outdoor expansion valve gradually decreases, avoiding violent fluctuations in refrigerant flow and system pressure during adjustment, ensuring a smooth transition of system operating pressure, effectively reducing the risk of unnecessary shutdowns triggered by control abrupt changes, and improving the reliability of air conditioning operation.

[0114] In another embodiment, a preset opening value can be directly reduced from the current opening to obtain the target opening that the outdoor expansion valve 15 should perform. This preset opening value can be set relatively large to quickly reduce the refrigerant flow.

[0115] The opening adjustment of the outdoor expansion valve 15 can control the temperature of the first electrical box, keeping it within a suitable range. If the first electrical box temperature is too low (i.e., the current opening is too large), it will cause significant bypass loss of unit capacity or lead to refrigerant return problems. If the first electrical box temperature is too high, it may trigger a short-term overheating of the first electrical box during refrigerant system fluctuations, causing a shutdown, or it may reduce the lifespan of electrical components. Therefore, the target temperature Tfino for the normal first electrical box temperature Tfin needs to be lower than the maximum electrical box temperature Tfinmax, with a certain margin. The target temperature can be set as Tfino = Tfinmax - K2. The following example illustrates how to adjust the opening of the outdoor expansion valve 15 based on the relationship between the first electrical box temperature and the target temperature.

[0116] In some embodiments, the first temperature is the temperature of a first electrical box, and the second temperature is the target temperature. Based on the first and second temperatures, the opening degree of the outdoor expansion valve 15 is controlled, and the control method executed by the controller is as follows: Figure 5 As shown, it includes: First scenario: Step 501: If the target temperature is greater than the temperature of the first electrical box, and the difference between the target temperature and the temperature of the first electrical box is greater than the second threshold, reduce the opening of the outdoor expansion valve 15.

[0117] For example, in the embodiments of this application, the target temperature can be considered as the optimal temperature, that is, the current heat dissipation state of the air conditioner is the best, and the refrigerant system is the most stable.

[0118] If the target temperature is greater than the temperature of the first electrical box, and the difference between the target temperature and the temperature of the first electrical box is greater than the second threshold, it indicates that the temperature of the first electrical box is lower than the target temperature. In order to achieve the optimal target temperature and improve the performance of the air conditioner, the temperature of the first electrical box can be increased. For example, this can be achieved by reducing the opening of the outdoor expansion valve 15 to reduce the refrigerant flow through the refrigerant radiator.

[0119] For example, the second threshold can be 1, but this application embodiment does not limit it.

[0120] For example, when Tfin < Tfino-1, the opening degree of the outdoor expansion valve 15 is reduced to EVC(n) = EVC(n-1)-1. Where EVC(n) is the target opening degree that the outdoor expansion valve 15 should perform after this adjustment, and EVC(n-1) is the current opening degree that the outdoor expansion valve 15 is operating at before this adjustment.

[0121] The second scenario: Step 502: If the temperature of the first electrical box is greater than the target temperature, and the difference between the temperature of the first electrical box and the target temperature is greater than the third threshold, increase the opening of the outdoor expansion valve 15.

[0122] If the temperature of the first electrical box is higher than the target temperature, and the difference between the temperature of the first electrical box and the target temperature is greater than the third threshold, it indicates that the temperature of the first electrical box is too high compared to the target temperature. The heat dissipation of the refrigerant radiator is insufficient, and there is too little refrigerant, which leads to the temperature of the first electrical box being too high. Therefore, it is necessary to increase the opening of the outdoor expansion valve 15 to increase the refrigerant flow through the refrigerant radiator to cool the electrical box.

[0123] For example, the third threshold can be 1, and the second threshold can be greater than or less than the third threshold. This is not limited in the embodiments of this application.

[0124] For example, when Tfin > Tfino + 1, the opening degree of the outdoor expansion valve 15 is increased to EVC(n) = EVC(n-1) + 1.

[0125] The above technical solution compares the temperature difference between the first electrical box and the target temperature. When the controller determines that the target temperature is greater than the first electrical box temperature, and the difference between the two is greater than a second threshold (indicating that the electrical box temperature is within a safe range but significantly low), the controller will reduce the opening of the outdoor expansion valve to limit the refrigerant flow. This effectively prevents the refrigerant radiator from overcooling, avoiding the waste of refrigerant energy caused by excessive heat dissipation. Valuable refrigerant is then used for heat exchange in the main circuit to improve overall unit efficiency. Furthermore, it proactively avoids the risk of condensation on the pipes caused by excessively low radiator surface temperature, achieving early intervention for anti-condensation protection. Simultaneously, when the controller determines that the first electrical box temperature is greater than the target temperature, and the difference between the two is greater than a third threshold (indicating that the electrical box temperature is approaching its upper limit and there is a risk of overheating), the controller will immediately increase the opening of the outdoor expansion valve. By increasing the refrigerant flow in the refrigerant radiator, the heat exchange capacity between the refrigerant and the electrical box can be rapidly improved, quickly removing heat from the electrical box and bringing the temperature back to near the target value. This not only ensures that the control board does not reduce its frequency due to overheating under extreme high-load conditions, but also prevents the equipment from operating at the edge of extreme temperature for a long time by setting a target temperature, effectively extending the service life of the internal components of the electrical module.

[0126] In another embodiment, the opening of the outdoor expansion valve 15 is kept constant when the temperature of the first electrical box is greater than or equal to the difference between the target temperature and the second threshold, and the temperature of the first electrical box is less than or equal to the sum of the target temperature and the third threshold.

[0127] In this embodiment, when the electrical box temperature Tfin falls within a range of 1°C above and below the target temperature Tfino (i.e., satisfying Tfino-1≤Tfin<Tfino+1), the controller executes the instruction to keep the outdoor expansion valve 15 opening unchanged, i.e., EVC(n)=EVC(n-1). This indicates that the control strategy has entered the safe dead zone, and the opening remains unchanged. Due to the inherent physical delay in the flow and heat exchange of refrigerant in the pipeline, if the controller frequently corrects the opening or closing of the outdoor expansion valve 15 (EVC) under extremely small temperature fluctuations, it is very easy to cause reciprocating oscillations in refrigerant flow and system pressure. This not only affects the overall energy efficiency performance of the multi-split system but also significantly increases the mechanical wear of the stepper motor valve body and may even induce additional load fluctuations in the compressor due to unstable refrigerant pressure.

[0128] Therefore, when the measured Tfin falls within a tolerance range of 1°C on both sides of the target value, the controller determines that the current refrigerant heat dissipation branch flow is in a very ideal micro-equilibrium state. At this time, the most reasonable operation is to keep the current valve opening unchanged, allowing the air conditioner to stably absorb these small transient temperature rises by relying on its own thermodynamic inertia. This effectively finds a stable anchor point between the two mutually restrictive boundaries of electrical box overheat protection and prevention of excessive cooling leading to condensation and refrigerant bypass loss. It not only provides sufficient response buffer time for the air conditioning system under transitional conditions, avoiding control disorder caused by over-adjustment, but also ensures that the compressor and outdoor expansion valve 15 can operate continuously in a long-term, stable, and low-loss physical environment.

[0129] In the embodiment, when the target temperature is greater than the temperature of the first electrical box and the difference between the target temperature and the temperature of the first electrical box is greater than the second threshold, the opening of the outdoor expansion valve 15 is reduced. The control method executed by the controller includes: when the target temperature is greater than the temperature of the first electrical box and the difference between the target temperature and the temperature of the first electrical box is greater than the second threshold, the opening of the outdoor expansion valve 15 is reduced according to the first preset opening value.

[0130] In the above embodiment, when the target temperature is greater than the temperature of the first electrical box and the difference between the target temperature and the temperature of the first electrical box is greater than the second threshold, the opening of the outdoor expansion valve 15 is reduced. Since the temperature of the first electrical box is not significantly different from the target temperature at this time, although there is a need to reduce the refrigerant flow, it is not urgent. Therefore, the current opening can be reduced by the first preset opening value to achieve the purpose.

[0131] For example, the first preset opening value can be 1 or 2, and this application embodiment does not limit it.

[0132] In the aforementioned technical solution, when the controller determines that the target temperature is greater than the temperature of the first electrical box, and the difference between the two exceeds a preset second threshold (i.e., the current temperature of the electrical box is significantly lower than the ideal heat dissipation equilibrium point), the controller does not blindly reduce the opening degree. Instead, it reduces the opening degree of the outdoor expansion valve by an absolute value according to a preset first opening degree value. This fixed-step opening degree reduction strategy allows for highly certain and fully controlled mechanical intervention when facing the risk of excessively low electrical box temperature. This avoids sudden reductions in refrigerant flow, severe fluctuations in system pressure, and potential system-wide alarm shutdowns caused by abrupt valve opening changes, thus improving the operational safety and signal response certainty of the air conditioner during the anti-condensation intervention phase.

[0133] In another embodiment, the current opening degree can be multiplied by a factor less than 1 to reduce the opening degree of the outdoor expansion valve 15.

[0134] In this embodiment, when the temperature of the first electrical box is greater than the target temperature, and the difference between the temperature of the first electrical box and the target temperature is greater than a third threshold, the opening of the outdoor expansion valve 15 is increased. The control method executed by the controller includes: If the temperature of the first electrical box is greater than the target temperature, and the difference between the temperature of the first electrical box and the target temperature is greater than the third threshold, the opening of the expansion valve is increased according to the second preset opening value.

[0135] In the above embodiment, when the temperature of the first electrical box is greater than the target temperature and the difference between the temperature of the first electrical box and the target temperature is greater than the third threshold, the opening of the outdoor expansion valve 15 is increased. Similarly, since the temperature of the first electrical box is not significantly different from the target temperature at this time, although there is a need to increase the refrigerant flow, it is not urgent. Therefore, the current opening can be increased by the first preset opening value to achieve the purpose.

[0136] For example, the first preset opening value can be 1 or 2, and this application embodiment does not limit it.

[0137] In the aforementioned technical solution, the controller determines that the electrical box temperature is higher than the target temperature and the difference between the two has exceeded a set third threshold. This means that high-power components such as the drive module inside the electrical box have accumulated considerable heat and are at the overheating boundary requiring immediate intervention. At this point, the controller increases the opening of the outdoor expansion valve in steps according to a preset second opening value. This fixed-step opening increase strategy ensures that when facing the risk of high temperatures, the refrigerant flow can be increased in a deterministic manner, increasing the refrigerant flow through the refrigerant radiator. This significantly improves the heat exchange efficiency between the radiator and the electrical box at the physical level, quickly removing the accumulated heat and preventing further temperature increases in the electrical box, thus improving the operational reliability of the air conditioner.

[0138] In another embodiment, the current opening degree can be multiplied by a factor greater than 1 to increase the opening degree of the outdoor expansion valve 15.

[0139] In the following embodiments, in the practical application of refrigerant heat dissipation control, the controller has set a fine-grained graded response mechanism for the working condition where the temperature of the first electrical box is close to the upper limit temperature of the electrical box and the temperature of the electrical box is rising. The opening degree of the outdoor expansion valve 15 is increased differently under different conditions. When the relationship between the temperature of the first electrical box (current measured temperature) and the temperature of the second electrical box is used as the temperature rise rate signal, the controller will take differentiated adjustment measures of the outdoor expansion valve 15 according to the different danger levels of approaching the upper limit temperature of the electrical box.

[0140] In some embodiments, the first temperature is the temperature of a first electrical box, and the second temperature is the upper limit temperature of the electrical box. Based on the first and second temperatures, control the opening degree of the outdoor expansion valve 15, such as... Figure 6 As shown, the control methods executed by the controller include: Step 601: When the temperature of the first electrical box is less than the upper limit temperature of the electrical box, the difference between the upper limit temperature of the electrical box and the temperature of the first electrical box is less than the fourth threshold, and the temperature of the first electrical box is greater than the temperature of the second electrical box, the opening degree of the outdoor expansion valve 15 is increased by the first degree. The temperature of the second electrical box is obtained by the first temperature sensor before the temperature of the first electrical box is obtained.

[0141] First-level opening adjustment: If the temperature of the first electrical box is less than the upper limit temperature of the electrical box, the difference between the upper limit temperature of the electrical box and the temperature of the first electrical box is less than the fourth threshold, and the temperature of the first electrical box is greater than the temperature of the second electrical box, it means that although the temperature of the first electrical box is close to the upper limit temperature of the electrical box, there is still a relatively safe temperature range. Therefore, the controller only performs a relatively small adjustment of the opening of the outdoor expansion valve 15, that is, increases the first opening, increases the opening of the outdoor expansion valve 15, thereby increasing the flow of refrigerant, thereby increasing the heat dissipation of the refrigerant radiator to the electrical box, so that the temperature of the electrical box and the first electrical box is reduced to a safer range.

[0142] In this embodiment, due to the different urgency of cooling the electrical box, the degree of increase in the opening of the outdoor expansion valve 15 should be less than the degree of adjustment of the opening of the outdoor expansion valve 15 when Tfin>Tfino+1.

[0143] Step 602: When the temperature of the first electrical box is less than the upper limit temperature of the electrical box, the difference between the upper limit temperature of the electrical box and the temperature of the first electrical box is less than the fifth threshold, and the temperature of the first electrical box is greater than the temperature of the second electrical box, the opening degree of the outdoor expansion valve 15 is increased by a second degree, the fifth threshold is less than the fourth threshold, and the second degree is greater than the first degree.

[0144] Second-level opening adjustment: If the temperature of the first electrical box is less than the upper limit temperature of the electrical box, the difference between the upper limit temperature of the electrical box and the temperature of the first electrical box is less than the fifth threshold, and the temperature of the first electrical box is greater than the temperature of the second electrical box, it indicates that although the temperature of the first electrical box still has a relatively safe temperature range, it is closer to the upper limit temperature of the electrical box than the temperature of the first electrical box mentioned in the first level of opening adjustment. Therefore, the controller should perform a relatively large adjustment of the opening of the outdoor expansion valve 15, that is, increase the second opening and increase the opening of the outdoor expansion valve 15, thereby increasing the refrigerant flow and increasing the heat dissipation of the refrigerant radiator to the electrical box, so that the temperature of the electrical box and the first electrical box is reduced to a safer range.

[0145] The second opening degree is greater than the first opening degree, and the fifth threshold is less than the fourth threshold.

[0146] For example, the fourth threshold can be 8, the fifth threshold can be 5, and the urgency of the opening adjustment at the second level is greater than the urgency of the opening adjustment at the first level.

[0147] The aforementioned technical solution employs a tiered electronic expansion valve opening adjustment in an emergency situation where the electrical box temperature approaches its upper limit and remains consistently higher than the previous temperature (indicating an upward trend). Based on the proximity to the upper limit temperature, different valve opening increases are executed. By introducing a fourth and fifth threshold, and combining this with a comparison between the current first electrical box temperature and the previous second electrical box temperature, it is determined that the electrical box is in a state of rapid heat accumulation. When the controller determines that although the first electrical box temperature has not yet reached its upper limit, the difference between the two has narrowed to within the fourth threshold, and the current temperature continues to be higher than the previous temperature, it identifies the area as being in the initial danger zone of heat accumulation. Based on this, the controller performs a relatively gentle intervention, increasing the outdoor expansion valve opening by a first degree. This action increases refrigerant flow to provide effective basic heat dissipation while avoiding excessive intervention that could cause pressure fluctuations in the early stages of temperature rise. Furthermore, a fifth threshold (i.e., the electrical box temperature is closer to the upper limit) is further set, lower than the fourth threshold. When the controller determines that the current temperature is approaching the fifth threshold and still shows a trend of continuous temperature increase, it judges that the heat dissipation demand is relatively urgent. The controller then takes a more significant intervention measure, greatly increasing the opening of the outdoor expansion valve to a second degree (and this second degree is greater than the first degree). This graded strategy based on proximity to the safety line ensures that the air conditioner can take appropriate emergency measures when facing different degrees of thermal crisis, guaranteeing the continuity, stability, and efficiency of air conditioning cooling or heating, greatly reducing the risk of user complaints, and comprehensively improving the long-term operational reliability of the entire unit under extreme conditions.

[0148] In some embodiments, the first opening degree is the current opening degree of the outdoor expansion valve 15, which is a multiple of the second opening degree. The current opening degree is the opening degree of the outdoor expansion valve 15 before the opening degree is adjusted. The second opening degree is a multiple of the third opening degree of the outdoor expansion valve 15, where the third multiple is greater than the second multiple.

[0149] For example, in the opening adjustment of the first level: when Tfin > Tfinmax - 8 and Tfin(n) > Tfin(n-1), EVC(n) = K3 × EVC(n-1), where K3 is the second multiple, for example, K3 = 1.5~2.

[0150] Tfin(n) is the temperature of the first electrical box (currently measured), and Tfin(n-1) is the temperature of the second electrical box, which was obtained by the first temperature sensor before the temperature of the first electrical box was obtained.

[0151] When Tfin > Tfinmax - 5 and Tfin(n) > Tfin(n-1), EVC(n) = K4 × EVC(n-1), where K4 is a third multiple, for example, K4 = 2~3.

[0152] The above technical solution further refines the adjustment method of the outdoor expansion valve opening. By setting the first and second openings to the second and third multiples of the current opening, respectively, and ensuring that the third multiple is greater than the second multiple, the controller can achieve dynamic multiplication adjustment when responding to different levels of overheating risk. This control strategy, which proportionally amplifies the current actual opening, ensures that each increase in refrigerant flow is appropriate: when the temperature is far from the upper limit, a smaller amplification factor (second multiple) is used for gentle compensation to avoid excessive refrigerant bypass leading to a decrease in the main circulation capacity; while when the temperature approaches the limit and is still rising, a larger amplification factor (third multiple) is used to rapidly inject a large amount of refrigerant for cooling. This effectively avoids the problems of insufficient response when the opening is large and excessive force when the opening is small due to fixed step adjustment, and significantly enhances the expansion valve's anti-disturbance capability and cooling efficiency when facing sudden temperature rises. While ensuring electrical control safety, it effectively guarantees the stability and efficiency of the entire unit's refrigerant circulation.

[0153] In implementation, each step of the above method can be completed by integrated logic circuits in the processor's hardware or by instructions in software. The steps of the method disclosed in the embodiments of this application can be directly manifested as execution by a hardware processor, or as a combination of hardware and software modules within the processor. The software modules can reside in random access memory, flash memory, read-only memory, programmable read-only memory, electrically erasable programmable memory, registers, or other mature storage media in the art. This storage medium is located in memory, and the processor executes the instructions in the memory, combining them with its hardware to complete the steps of the above method. To avoid repetition, detailed descriptions are omitted here.

[0154] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of the embodiments of this application.

[0155] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0156] In the embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative. For instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the displayed or discussed mutual couplings, direct couplings, or communication connections may be through some interfaces; indirect couplings or communication connections between devices or units may be electrical, mechanical, or other forms.

[0157] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0158] In addition, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit.

[0159] If the aforementioned function is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application embodiment, essentially, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0160] The above description is merely a specific implementation of the embodiments of this application, but the protection scope of the embodiments of this application 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 embodiments of this application should be included within the protection scope of the embodiments of this application. Therefore, the protection scope of the embodiments of this application should be determined by the protection scope of the claims.

Claims

1. An air conditioner, characterized in that, include: Indoor unit, An outdoor unit, connected to the indoor unit, the outdoor unit comprising: compressor; The outdoor heat exchanger is configured to exchange heat with the outdoor air via refrigerant; Electrical modules, including: An electrical box, containing multiple electrical components; A refrigerant radiator is installed on the electrical box, and the refrigerant radiator is used to dissipate heat from the electrical box through refrigerant. An outdoor expansion valve is connected in series with the refrigerant radiator, and the outdoor expansion valve is used to control the flow rate of refrigerant entering the refrigerant radiator; The sensor module includes: A first temperature sensor is used to obtain the electrical box temperature of the electrical box; The second temperature sensor is used to obtain the outdoor ambient temperature. The third temperature sensor is used to obtain the refrigerant inlet temperature at the inlet of the refrigerant radiator. A controller, connected to the outdoor unit and the indoor unit, is configured to: A first temperature and a second temperature are obtained. The first temperature is the electrical box temperature obtained by the first temperature sensor. The second temperature is the upper limit temperature of the electrical box, a target temperature, or the outdoor ambient temperature obtained by the second temperature sensor. The target temperature is less than the upper limit temperature of the electrical box and falls within a preset temperature range based on the upper limit temperature of the electrical box. Alternatively, the first temperature is the refrigerant inlet temperature at the refrigerant radiator inlet obtained by the third temperature sensor, and the second temperature is the outdoor ambient temperature. The opening degree of the outdoor expansion valve is controlled based on the first temperature and the second temperature.

2. The air conditioner according to claim 1, characterized in that, The first temperature is either the temperature of the first electrical box or the refrigerant inlet temperature, and the second temperature is the outdoor ambient temperature. The controller is configured to control the opening degree of the outdoor expansion valve based on the first temperature and the second temperature, including: When the outdoor ambient temperature is greater than the first temperature and the difference between the outdoor ambient temperature and the first temperature is greater than or equal to a first threshold, the opening degree of the outdoor expansion valve is reduced.

3. The air conditioner according to claim 2, characterized in that, The controller is configured to reduce the opening of the outdoor expansion valve, including: The outdoor expansion valve is controlled to decrease by a first multiple of its current opening, where the current opening is the opening of the outdoor expansion valve before adjustment.

4. The air conditioner according to claim 1, characterized in that, The first temperature is the temperature of the first electrical box, and the second temperature is the target temperature. The controller is configured to control the opening degree of the outdoor expansion valve based on the first temperature and the second temperature, including: If the target temperature is greater than the temperature of the first electrical box, and the difference between the target temperature and the temperature of the first electrical box is greater than a second threshold, the opening of the outdoor expansion valve is reduced. When the temperature of the first electrical box is greater than the target temperature, and the difference between the temperature of the first electrical box and the target temperature is greater than a third threshold, the opening of the outdoor expansion valve is increased.

5. The air conditioner according to claim 4, characterized in that, The controller is also configured to: When the temperature of the first electrical box is greater than or equal to the difference between the target temperature and the second threshold, and the temperature of the first electrical box is less than or equal to the sum of the target temperature and the third threshold, the opening of the outdoor expansion valve remains unchanged.

6. The air conditioner according to claim 4, characterized in that, The controller is configured to reduce the opening of the outdoor expansion valve, including: The opening degree of the outdoor expansion valve is reduced according to the first preset opening degree value.

7. The air conditioner according to claim 4, characterized in that, The controller is configured to increase the opening degree of the outdoor expansion valve, including: Increase the opening of the expansion valve according to the second preset opening value.

8. The air conditioner according to claim 1, characterized in that, The first temperature is the temperature of the first electrical box, and the second temperature is the upper limit temperature of the electrical box. The controller is configured to control the opening degree of the outdoor expansion valve based on the first temperature and the second temperature, including: When the temperature of the first electrical box is less than the upper limit temperature of the electrical box, the difference between the upper limit temperature of the electrical box and the temperature of the first electrical box is less than a fourth threshold, and the temperature of the first electrical box is greater than the temperature of the second electrical box, the opening of the outdoor expansion valve is increased by a first degree. The temperature of the second electrical box is obtained by the first temperature sensor before the temperature of the first electrical box is obtained. When the temperature of the first electrical box is less than the upper limit temperature of the electrical box, the difference between the upper limit temperature of the electrical box and the temperature of the first electrical box is less than a fifth threshold, and the temperature of the first electrical box is greater than the temperature of the second electrical box, the opening degree of the outdoor expansion valve is increased by a second degree, wherein the fifth threshold is less than the fourth threshold, and the second degree is greater than the first degree.

9. The air conditioner according to claim 8, characterized in that, The first opening is the current opening of the outdoor expansion valve, which is a multiple of the second opening. The current opening is the opening of the outdoor expansion valve before the opening is adjusted. The second opening degree is a multiple of the current opening degree of the outdoor expansion valve, where the third multiple is greater than the second multiple.

10. The air conditioner according to claim 1, characterized in that, The outdoor unit also includes: A subcooler is used to cool the refrigerant supplied from the outdoor heat exchanger, so as to deliver the cooled refrigerant to the indoor unit; wherein, The electrical module and the outdoor expansion valve are connected in parallel on the refrigerant passage between the subcooler and the outdoor heat exchanger for transferring refrigerant.

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