Air conditioner and mode switching control method thereof

Abstract

The invention relates to an air conditioner and a mode switching control method thereof, relates to the technical field of air conditioning equipment, and aims to solve the problem that an air conditioning unit cannot operate normally due to abnormality of a four-way valve. The air conditioner comprises a compressor, a four-way valve, an outdoor heat exchanger, a throttler, an indoor heat exchanger, a pressure regulating tank and a pressure regulating valve. The compressor is provided with an air return port and an exhaust port, the four-way valve is provided with four ports, the air return port is communicated with a first port of the four-way valve, and the exhaust port is communicated with a second port of the four-way valve. One end of the outdoor heat exchanger is communicated with a third port of the four-way valve through the pressure regulating tank, and the other end of the outdoor heat exchanger is communicated with a fourth port of the four-way valve through the throttler and the indoor heat exchanger in sequence. And between the third port and the outdoor heat exchanger, the pressure regulating tank is connected with the refrigerant loop through the pressure regulating valve.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of air conditioning equipment, in particular to an air conditioner and a mode switching control method thereof. BACKGROUND

[0002] As a core component in heat pump type air conditioners, the four-way valve bears the key function of switching the flow direction of refrigerant to realize the conversion between cooling and heating modes. In the prior art, the reversing mechanism of the four-way valve mainly relies on the displacement movement of the slider inside the main valve body under the action of the pressure difference on both sides, which is accurately controlled by the pilot valve through the capillary tube. However, in actual operation, due to system pressure fluctuations or control logic defects, the four-way valve may have difficulty in reversing, may not be in place, or may even be stuck, resulting in the air conditioning unit being unable to operate normally, which seriously affects the user experience and equipment reliability. SUMMARY

[0003] The present application provides an air conditioner and a mode switching control method thereof to solve the problem of the air conditioning unit being unable to operate normally due to abnormal four-way valve.

[0004] In a first aspect, the embodiments of the present application provide an air conditioner, which includes a compressor, a four-way valve, an outdoor heat exchanger, a throttler, an indoor heat exchanger, a pressure tank and a pressure regulating valve. The compressor has a suction port and a discharge port, and the four-way valve has four ports. The suction port is in communication with the first port of the four-way valve, and the discharge port is in communication with the second port of the four-way valve. One end of the outdoor heat exchanger is connected to the third port of the four-way valve through the pressure tank, and the other end of the outdoor heat exchanger is connected to the fourth port of the four-way valve through the throttler and the indoor heat exchanger in sequence. Between the third port and the outdoor heat exchanger, the pressure tank is connected to the refrigerant circuit through the pressure regulating valve.

[0005] In some embodiments, the air conditioner includes a first pressure sensor, a control module and a second pressure sensor. The first pressure sensor is arranged in the pressure tank and is used to detect a first pressure parameter in the pressure tank. The second pressure sensor is arranged at the suction port and is used to detect a second pressure parameter when the compressor is suctioning. The compressor, the four-way valve, the pressure regulating valve, the first pressure sensor and the second pressure sensor are electrically connected to the control module.

[0006] In some embodiments, the air conditioner includes a heating element arranged in the pressure tank, and the control module is electrically connected to the heating element to control the operating state of the heating element.

[0007] In some embodiments, the air conditioner includes a third pressure sensor arranged at the discharge port to detect a fourth pressure parameter when the compressor is discharging, and the third pressure sensor is electrically connected to the control module.

[0008] In some embodiments, the indoor heat exchanger includes a first heat exchange channel and a second heat exchange channel. The first and second heat exchange channels are isolated from each other and used for heat exchange. The first heat exchange channel is connected between the fourth port and the expansion valve. The air conditioner also includes a temperature sensor disposed at the inlet end of the second heat exchange channel to detect the inlet water temperature of the second heat exchange channel, and the temperature sensor is electrically connected to the control module.

[0009] Secondly, embodiments of this application provide a mode switching control method for an air conditioner, used to control the air conditioner in the first aspect. The mode switching control method includes: With the compressor turned off.

[0010] Obtain the first pressure parameter inside the pressure regulating tank, and obtain the second pressure parameter at the return air port.

[0011] Determine whether the sum of the second pressure parameter and the first threshold is less than or equal to the first pressure parameter.

[0012] If the sum of the second pressure parameter and the first threshold is less than or equal to the first pressure parameter, the pressure regulating valve is kept closed.

[0013] Receive mode switching command.

[0014] The pressure regulating valve is opened for a first preset time and the four-way valve is switched.

[0015] Complete mode switching.

[0016] In some embodiments, where the air conditioner includes a heating element and the heating element is disposed within a pressure regulating tank, the mode switching control method includes: If the sum of the second pressure parameter and the first threshold is less than or equal to the first pressure parameter, the pressure regulating valve and the heating element are kept closed.

[0017] If the sum of the second pressure parameter and the first threshold is greater than the first pressure parameter, the pressure regulating valve is closed, and the heating element is turned on for a second preset duration. The first and second pressure parameters are then re-detected and determined to ensure they meet the requirements.

[0018] Thirdly, embodiments of this application provide a mode switching control method for an air conditioner, used to control the air conditioner in the first aspect. The mode switching control method includes: With the compressor on.

[0019] Obtain the second pressure parameter at the return port and the fourth pressure parameter at the exhaust port.

[0020] Determine whether the sum of the second pressure parameter and the second threshold is greater than the fourth pressure parameter.

[0021] If the sum of the second pressure parameter and the second threshold is less than or equal to the fourth pressure parameter, the pressure regulating valve is opened for a first preset duration.

[0022] After a preset time, re-detect and determine whether the fourth pressure parameter and the second pressure parameter meet the requirements.

[0023] In some implementations, the mode switching control method includes: If the sum of the second pressure parameter and the second threshold is greater than the fourth pressure parameter, determine whether the sum of the second pressure parameter and the third threshold is greater than or equal to the fourth pressure parameter.

[0024] If the sum of the second pressure parameter and the third threshold is less than the fourth pressure parameter, maintain the current operating state. After a first preset time, re-detect and determine whether the fourth pressure parameter and the second pressure parameter meet the requirements.

[0025] The third threshold is less than the second threshold.

[0026] In some embodiments, where the air conditioner includes a heating element and the heating element is disposed within a pressure regulating tank, the mode switching control method includes: If the sum of the second pressure parameter and the third threshold is greater than the fourth pressure parameter, obtain the first pressure parameter inside the pressure regulating tank and the second pressure parameter at the return port.

[0027] Determine whether the sum of the second pressure parameter and the first threshold is less than or equal to the first pressure parameter.

[0028] If the sum of the second pressure parameter and the first threshold is less than or equal to the first pressure parameter, the pressure regulating valve and the heating element are kept closed.

[0029] Receive mode switching command.

[0030] The compressor is shut down, the pressure regulating valve is opened for a first preset time, and the four-way valve is switched.

[0031] In some implementations, the mode switching control method includes: If the sum of the second pressure parameter and the first threshold is greater than the first pressure parameter, the pressure regulating valve is closed, and the heating element is turned on for a second preset duration. The first and second pressure parameters are then re-detected and determined to ensure they meet the requirements.

[0032] Fourthly, embodiments of this application provide a mode switching control method for an air conditioner, used to control the air conditioner in the first aspect. The mode switching control method includes: During the defrosting process of the air conditioner.

[0033] Obtain the inlet water temperature of the indoor heat exchanger and the fourth pressure parameter at the exhaust port.

[0034] Determine whether the conditions are met: the inlet water temperature is less than the temperature threshold and the fourth pressure parameter is less than the fourth threshold.

[0035] If the inlet water temperature is lower than the temperature threshold and the fourth pressure parameter is lower than the fourth threshold, the pressure regulating valve will be closed, and the current operating state will be maintained.

[0036] In some embodiments, where the air conditioner includes a heating element and the heating element is disposed within a pressure regulating tank, the mode switching control method includes: If the inlet water temperature is less than the temperature threshold and the fourth pressure parameter is less than the fourth threshold, then the pressure regulating valve and the heating element are kept closed.

[0037] If the inlet water temperature is lower than the temperature threshold and the fourth pressure parameter is not lower than the fourth threshold, then the pressure regulating valve is opened for a first preset time, and the heating element is kept closed.

[0038] The technical solutions provided in this application have the following advantages compared with the prior art: Therefore, by introducing a pressure regulating tank and valve into the refrigerant circuit, the air conditioner can pre-adjust and balance the high-pressure side pressure before the four-way valve switches. This effectively reduces the risk of excessive high and low pressure differences during switching, reduces the unbalanced force acting on the four-way valve slider, and thus improves problems such as difficult switching, incomplete switching, or jamming. At the same time, this structure helps alleviate pressure shocks and noise generated during switching, reduces mechanical damage to system components, and improves the reliability of the four-way valve and the system's lifespan. Attached Figure Description The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0039] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0040] One or more embodiments are illustrated by way of example with reference numerals in the accompanying drawings. These illustrations do not constitute a limitation on the embodiments. Elements with the same reference numerals in the drawings are denoted as similar elements. Unless otherwise stated, the figures in the drawings are not to be limited by scale.

[0041] Figure 1 This is a schematic diagram of the connection structure of an air conditioner provided in an embodiment of this application; Figure 2 for Figure 1A partial structural schematic diagram of the pressure regulating tank shown in the image; Figure 3 This application provides an electrical connection diagram of an air conditioner according to an embodiment of the present application. Figure 4 A flowchart of a mode switching control method for a first type of air conditioner provided in this application embodiment; Figure 5 This is a flowchart of a second mode switching control method for an air conditioner provided in an embodiment of this application; Figure 6 A flowchart of a third mode switching control method for an air conditioner provided in this application embodiment; Figure 7 This is a schematic diagram of the control module provided in an embodiment of this application.

[0042] Explanation of reference numerals in the attached figures: 100. Air conditioner; 10. Compressor; 11. Return air port; 12. Exhaust port; 20. Four-way valve; 21. First port; 22. Second port; 23. Third port; 24. Fourth port; 30. Outdoor heat exchanger; 40. Indoor heat exchanger; 41. First heat exchange channel; 42. Second heat exchange channel; 50. Throttling device; 51. Pressure regulating tank; 52. Pressure regulating valve; 53. Heating element; 54. First pressure sensor; 61. Control module; 611. Processor; 612, Communication interface; 613, Memory; 614, Communication bus; 62, Second pressure sensor; 63, Third pressure sensor; 64, Temperature sensor; P1, First pressure parameter; P2, Second pressure parameter; P3, First threshold; P4, Fourth pressure parameter; P5, Second threshold; P6, Third threshold; P7, Fourth threshold; T, Inlet water temperature; T1, Temperature threshold; t1, First preset duration; t2, Second preset duration. Detailed Implementation

[0043] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0044] The following disclosure provides numerous different embodiments or examples for implementing various structures of this application. To simplify the disclosure, specific examples of components and arrangements are described below. These are merely examples and are not intended to limit the scope of this application. Furthermore, reference numerals and / or letters may be repeated in different examples. Such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed.

[0045] For ease of description, spatial relative terms may be used in the text to describe the relative position or movement of one element or feature relative to another element or feature, as shown in the figure. These relative terms include, for example, "inside," "outside," "middle," "outer," "below," "below," "above," "front," "back," etc. Such spatial relative terms are intended to include different orientations of the device in use or operation, other than those depicted in the figure. For example, if the device in the figure undergoes a positional flip, orientation change, or change of motion, these directional indications will change accordingly. For instance, an element described as "below other elements or features" or "below other elements or features" will subsequently be oriented "above other elements or features" or "above other elements or features." Therefore, the example term "below" can include both upper and lower orientations. The device may be otherwise oriented (rotated 90 degrees or in other directions), and the spatial relative descriptors used in the text will be interpreted accordingly.

[0046] Please see Figures 1 to 7 This application provides an air conditioner and its mode switching control method to solve the problem of abnormal operation of the air conditioning unit caused by the failure of the four-way valve switching.

[0047] Firstly, such as Figure 1 and Figure 2 As shown in the illustration, this application provides an air conditioner 100, including a compressor 10, a four-way valve 20, an outdoor heat exchanger 30, a throttle valve 50, an indoor heat exchanger 40, a pressure regulating tank 51, and a pressure regulating valve 52. The compressor 10 has a return port 11 and an exhaust port 12. The four-way valve 20 has four ports; the return port 11 is connected to the first port 21 of the four-way valve 20, and the exhaust port 12 is connected to the second port 22 of the four-way valve 20. One end of the outdoor heat exchanger 30 is connected to the third port 23 of the four-way valve 20 via the pressure regulating tank 51, and the other end of the outdoor heat exchanger 30 is connected to the fourth port 24 of the four-way valve 20 via the throttle valve 50 and the indoor heat exchanger 40. Between the third port 23 and the outdoor heat exchanger 30, the pressure regulating tank 51 is connected to the refrigerant circuit via the pressure regulating valve 52.

[0048] For ease of understanding, the following explains some key terms in this embodiment: Compressor 10: As the core component of the refrigeration cycle of air conditioner 100, its function is to compress the low-temperature, low-pressure gaseous refrigerant into a high-temperature, high-pressure gaseous refrigerant and make it circulate in the refrigerant circuit.

[0049] Four-way valve 20: A valve used to switch the direction of refrigerant flow, enabling the air conditioner 100 to switch between cooling and heating modes by changing its internal flow path. It typically has four ports, which are connected to the return port 11 of the compressor 10, the exhaust port 12, and the indoor and outdoor heat exchangers, respectively.

[0050] Pressure regulating tank 51: A container for storing and regulating refrigerant pressure, which is installed in the refrigerant circuit and can buffer or store refrigerant under specific operating conditions to stabilize system pressure.

[0051] Outdoor heat exchanger 30: In cooling mode, it acts as a condenser, condensing and releasing heat from the high-temperature, high-pressure refrigerant. In heating mode, it acts as an evaporator, absorbing heat from the outside environment to evaporate the refrigerant.

[0052] Throttling device 50: A device for throttling and reducing the pressure of refrigerant, usually installed before the heat exchanger, so that the high-pressure liquid refrigerant becomes a low-pressure liquid or gas-liquid mixture after throttling, creating conditions for subsequent evaporation and heat absorption.

[0053] Indoor heat exchanger 40: In cooling mode, it acts as an evaporator, absorbing indoor heat to evaporate the refrigerant. In heating mode, it acts as a condenser, condensing the high-temperature, high-pressure refrigerant to release heat and supply heat to the room.

[0054] Pressure regulating valve 52: A valve used to control the flow of refrigerant between pressure regulating tank 51 and refrigerant circuit, thereby achieving balanced regulation of system pressure through its open or closed state.

[0055] Refrigerant circuit: refers to the closed piping system in which the refrigerant circulates inside the air conditioner 100, including major components such as compressor 10, four-way valve 20, heat exchanger, and throttle valve 50.

[0056] The air conditioner 100 in this embodiment has a refrigerant circuit mainly composed of a compressor 10, a four-way valve 20, a pressure regulating tank 51, an outdoor heat exchanger 30, a throttle valve 50, an indoor heat exchanger 40, and a pressure regulating valve 52.

[0057] Specifically, the compressor 10 can be a common reciprocating compressor 10, rotary compressor 10, or scroll compressor 10. The compressor 10 has a return port 11 and a discharge port 12, wherein the return port 11 is used to draw in low-pressure refrigerant from the evaporator, and the discharge port 12 is used to discharge high-pressure refrigerant.

[0058] The four-way valve 20 can be an electromagnetically driven slider-type four-way valve 20. This four-way valve 20 has four ports, wherein the return port 11 of the compressor 10 is connected to the first port 21 of the four-way valve 20, and the discharge port 12 of the compressor 10 is connected to the second port 22 of the four-way valve 20. By controlling the opening and closing of the pilot valve, the slider in the main valve body can be driven to move, thereby changing the refrigerant flow direction and realizing the switching between cooling and heating modes.

[0059] The pressure regulating tank 51 can be a simple metal container with its internal space used to store refrigerant. The outdoor heat exchanger 30 can be a finned tube heat exchanger. One end of the outdoor heat exchanger 30 is connected to the pressure regulating tank 51 via a pipe, and the pressure regulating tank 51 is then connected to the third port 23 of the four-way valve 20 via another pipe. Under certain operating conditions, the pressure regulating tank 51 can act as a buffer, absorbing excess refrigerant in the system or releasing stored refrigerant to help balance the system pressure.

[0060] The expansion valve 50 can be a capillary tube or an expansion valve. The indoor heat exchanger 40 can be a finned tube heat exchanger. The other end of the outdoor heat exchanger 30 is connected to the expansion valve 50 via a pipe, and the expansion valve 50 is then connected to the indoor heat exchanger 40 via a pipe. The indoor heat exchanger 40 is finally connected to the fourth port 24 of the four-way valve 20 via a pipe. After passing through the expansion valve 50, the refrigerant pressure decreases, and it enters the indoor heat exchanger 40 for heat exchange.

[0061] The pressure regulating valve 52 can be a simple manual shut-off valve or a normally open / normally closed solenoid valve. This valve 52 is located on the connecting pipeline between the pressure regulating tank 51 and the refrigerant circuit, specifically between the third port 23 of the four-way valve 20 and the outdoor heat exchanger 30. Through manual operation or simple electrical signal control, the pressure regulating valve 52 can connect or disconnect the pressure regulating tank 51 from the refrigerant circuit, thereby affecting the system pressure.

[0062] Therefore, the air conditioner 100, by introducing a pressure regulating tank 51 and a pressure regulating valve 52 located between the four-way valve 20 and the exhaust port 12 in the refrigerant circuit, and by setting a positive or negative pressure difference between the pressure regulating tank 51 and the exhaust port 12, can temporarily store and release the high-pressure side pressure before the four-way valve 20 switches, thereby regulating and balancing the refrigerant pressure on the high-pressure side, during the process of connecting the refrigerant circuit and the pressure regulating tank 51 through the pressure regulating valve 52. For example, by setting the pressure regulating tank 51 to a negative pressure, the high-pressure side pressure can be temporarily stored before switching, significantly reducing the force on the slider during the switching of the four-way valve 20, eliminating hydraulic shock during switching, and reducing the resistance of the switching slider, thereby improving the switching success rate and system reliability. At the same time, this structure helps to alleviate the pressure shock and noise generated during switching, reduces mechanical damage to system components, and improves the operational reliability of the four-way valve 20 and the system lifespan.

[0063] In addition, the pressure regulating tank 51 can be pre-set to a positive pressure, which can pre-release the high-pressure side pressure before switching, thereby significantly increasing the force on the slider when the four-way valve 20 switches, so as to avoid the failure of switching due to the small pressure difference force acting on the switching slider.

[0064] In some implementations, such as Figure 1 , Figure 2 and Figure 3 As shown, the air conditioner 100 includes a first pressure sensor 54, a control module 61, and a second pressure sensor 62. The first pressure sensor 54 is located inside the pressure regulating tank 51 and is used to detect a first pressure parameter P1 inside the pressure regulating tank 51. The second pressure sensor 62 is located at the return air port 11 and is used to detect a second pressure parameter P2 when the compressor 10 returns air. The compressor 10, the four-way valve 20, the pressure regulating valve 52, the first pressure sensor 54, and the second pressure sensor 62 are electrically connected to the control module 61.

[0065] The first pressure sensor 54 is a device that converts the pressure signal inside the pressure regulating tank 51 into an electrical signal. This sensor can be of various types, such as piezoresistive, capacitive, or piezoelectric. Its core function is to acquire the pressure value inside the pressure regulating tank 51, i.e., the first pressure parameter P1, in real time and accurately, and transmit it to the control module 61 in the form of an electrical signal. By continuously monitoring the pressure inside the pressure regulating tank 51, the control module 61 can grasp the operating status of the pressure regulating tank 51, which is crucial for the storage and distribution of refrigerant and the balance of system pressure.

[0066] The control module 61 is the core of the entire intelligent control system of the air conditioner 100. It is typically composed of a microcontroller (MCU), digital signal processor (DSP), or programmable logic controller (PLC). This module integrates a processor, memory, and input / output interfaces. It is responsible for receiving signals from various sensors, executing preset control logic and algorithms, and sending control commands to the actuators. By processing and analyzing the received pressure data, the control module 61 can comprehensively judge the operating status of the air conditioner 100 and make corresponding control decisions accordingly.

[0067] The second pressure sensor 62, similar to the first pressure sensor 54, is also a device that converts pressure signals into electrical signals, but it is specifically located at the return port 11 of the compressor 10. This sensor is used to detect the pressure of the compressor 10 when it draws in refrigerant, i.e., the second pressure parameter P2, and feeds this parameter back to the control module 61. The pressure at the return port 11 of the compressor 10 is an important indicator reflecting the suction load of the compressor 10 and the low-pressure side status of the system. Monitoring this parameter helps to evaluate the operating efficiency of the compressor 10 and the smoothness of the refrigerant circulation.

[0068] The compressor 10, four-way valve 20, pressure regulating valve 52, first pressure sensor 54, and second pressure sensor 62 establish a communication connection with the control module 61 via electrical signals, enabling the effective transmission of detection and control signals. This electrical connection can be implemented via wired means (such as wires or ribbon cables) or wireless means. Through this connection, the control module 61 can receive real-time pressure data from the first pressure sensor 54 and the second pressure sensor 62, and based on this data, send precise control commands to the compressor 10, four-way valve 20, and pressure regulating valve 52, such as adjusting the operating frequency of the compressor 10, switching the flow direction of the four-way valve 20, and controlling the opening or closing state and opening duration of the pressure regulating valve 52.

[0069] Through the above technical solution, the air conditioner 100 can achieve real-time and accurate monitoring of key pressure parameters, and perform intelligent control based on this. The first pressure sensor 54 and the second pressure sensor 62 continuously provide the control module 61 with pressure data from the pressure regulating tank 51 and the compressor 10 at the return port 11, enabling the control module 61 to fully grasp the operating status of the refrigerant circuit. Based on these real-time pressure parameters and combined with preset control strategies, the control module 61 can dynamically adjust the operating status of the compressor 10, the four-way valve 20, and the pressure regulating valve 52.

[0070] For example, when switching modes, if the compressor 10 has a high pressure at the return port 11, the pressure difference force acting on the switching slider of the four-way valve 20 when switching the refrigerant flow direction is small. The control module 61 can control the pressure regulating valve 52 to open for a period of time before the refrigerant flow direction switch when there is a high pressure refrigerant in the pressure regulating tank 51, so as to supplement the pressure to the refrigerant branch where the exhaust port 12 of the compressor 10 is located, thereby increasing the force acting on the refrigerant slider in the four-way valve 20, thereby achieving a stable switching of the refrigerant flow direction.

[0071] In some implementations, such as Figure 2 and Figure 3 As shown, the air conditioner 100 includes a heating element 53, which is disposed in a pressure regulating tank 51. The control module 61 is electrically connected to the heating element 53 and is used to control the operating status of the heating element 53.

[0072] The heating element 53 is a device that converts electrical energy into heat energy and transfers it to the surrounding medium. This heating element 53 can heat the refrigerant in the pressure regulating tank 51 to regulate the pressure of the refrigerant within the tank 51. For example, the heating element 53 can be in the form of a resistance wire heater, a PTC heater, or a heat pipe heater.

[0073] The control module 61 is electrically connected to the power input terminal of the heating element 53 via a wire, thereby intelligently controlling the start-up and shutdown duration and heating power of the heating element 53 based on information such as system operating status and pressure parameters. For example, the control module 61 can directly control the power supply to the heating element 53 via a relay or solid-state relay. For an adjustable power heating element 53, the control module 61 can also control the heating power by adjusting the duty cycle or voltage to achieve more precise temperature and pressure control. The control module 61 can determine the operating status and operating duration of the heating element 53 based on the first pressure parameter P1 detected by the first pressure sensor 54 inside the pressure regulating tank 51, the second pressure parameter P2 detected by the second pressure sensor 62 at the return air port 11, and a preset control strategy.

[0074] By incorporating a heating element 53 within the pressure regulating tank 51 and controlling its operation via a control module 61, the temperature of the refrigerant within the pressure regulating tank 51 can be effectively increased, promoting refrigerant evaporation and thus increasing the pressure within the tank. This helps ensure that the refrigerant state within the pressure regulating tank 51 meets system operating requirements when ambient temperatures are low or when a rapid system response is needed.

[0075] In some implementations, such as Figure 1 and Figure 3 As shown, the air conditioner 100 includes a third pressure sensor 63, which is located at the exhaust port 12 and is used to detect the fourth pressure parameter P4 when the compressor 10 is discharging. The third pressure sensor 63 is electrically connected to the control module 61.

[0076] The third pressure sensor 63 is a device that converts fluid pressure into an electrical signal output. Its function is to monitor the pressure at the discharge port 12 of the compressor 10 in real time, i.e., the fourth pressure parameter P4. The third pressure sensor 63 can be a piezoresistive, capacitive, or thin-film sensor; the specific choice depends on factors such as required measurement accuracy, response speed, environmental adaptability, and cost. Typically, the third pressure sensor 63 is designed to withstand high refrigerant pressure and a wide temperature range, and possesses good stability.

[0077] The third pressure sensor 63 is located at the discharge port 12 of the compressor 10 to ensure that it can directly and accurately measure the pressure of the refrigerant gas discharged by the compressor 10. The discharge port 12 is the channel through which the compressor 10 delivers high-temperature and high-pressure refrigerant gas to the condenser (or outdoor heat exchanger 30). Pressure measurement at this location can directly reflect the working load of the compressor 10 and the operating status of the high-pressure side of the system.

[0078] The fourth pressure parameter P4 refers to the actual pressure value at the discharge end of compressor 10. By detecting this parameter through the third pressure sensor 63, the control module 61 can obtain real-time operating data on the high-pressure side of the system. This pressure value is an important basis for evaluating the performance of compressor 10 and determining whether there are abnormalities such as overload, blockage, excessive refrigerant, or leakage in the system.

[0079] Through the above technical solution, a third pressure sensor 63 is added to the exhaust port 12 of the air conditioner 100 and electrically connected to the control module 61. The control module 61 can obtain the fourth pressure parameter P4 in real time when the compressor 10 is discharging. This solves the problem that relying solely on the pressure of the pressure regulating tank 51 and the return air port 11 is insufficient to fully grasp the operating status of the high-pressure side of the system. Based on the fourth pressure parameter P4, the control module 61 can more comprehensively evaluate the workload of the compressor 10 and the operating status of the high-pressure side of the system, thereby achieving more precise control over the operation of the air conditioner 100.

[0080] For example, in heating mode, the control module 61 can adjust the speed of the compressor 10 or the opening of the pressure regulating valve 52 in a timely manner according to the change of the fourth pressure parameter P4, so as to avoid high pressure overload or optimize system efficiency.

[0081] Furthermore, during the process of switching the refrigerant flow direction through the four-way valve 20, the difference between the second and fourth pressure parameters can be used to directly and clearly determine whether there will be any high-pressure or low-pressure abnormalities during the switching process of the four-way valve 20. This allows the control module 61 to accurately balance the pipeline pressure between the exhaust port 12 and the four-way valve 20 through flexible control of the pressure regulating valve 52 and the heating element 53, so as to keep the mode switching stable and improve the operational reliability, energy efficiency ratio and fault diagnosis capability of the air conditioner 100.

[0082] In some implementations, such as Figure 1 As shown, the indoor heat exchanger 40 includes a first heat exchange channel 41 and a second heat exchange channel 42. The first heat exchange channel 41 and the second heat exchange channel 42 are isolated from each other and used for heat exchange. The first heat exchange channel 41 is connected between the fourth port 24 and the throttle 50. The air conditioner 100 also includes a temperature sensor 64, which is disposed at the inlet end of the second heat exchange channel 42 for detecting the inlet water temperature of the second heat exchange channel 42, and the temperature sensor 64 is electrically connected to the control module 61.

[0083] The indoor heat exchanger 40 is designed with two independent and isolated fluid channels: a first heat exchange channel 41 and a second heat exchange channel 42. This design allows the indoor heat exchanger 40 to handle two different heat exchange media simultaneously or independently. For example, the first heat exchange channel 41 can exchange heat with the outdoor heat exchanger 30 via refrigerant to improve heat exchange efficiency. The second heat exchange channel 42, on the other hand, can be used for heat exchange with water or other liquid media to reduce the capacity of the refrigerant circuit and decrease refrigerant usage.

[0084] To accurately monitor and control the heat exchange process of the second heat exchange channel 42, this application also includes a temperature sensor 64. This temperature sensor 64 is located at the inlet end of the second heat exchange channel 42, and its main function is to detect the temperature of the liquid medium entering the second heat exchange channel 42 in real time. For example, when the second heat exchange channel 42 is used for water circulation, the sensor can accurately obtain the inlet water temperature T. The temperature sensor 64 is electrically connected to the control module 61 so that the control module 61 can monitor, receive, process, and analyze the inlet water temperature T in real time, providing the control module 61 with key operating parameters.

[0085] Secondly, embodiments of this application provide a mode switching control method for an air conditioner, used to control the air conditioner 100 in the first aspect, such as... Figure 4 As shown, the mode switching control method includes the following steps: With compressor 10 in the off state.

[0086] Obtain the first pressure parameter P1 inside the pressure regulating tank 51, and obtain the second pressure parameter P2 at the return air port 11.

[0087] Determine whether the sum of the second pressure parameter P2 and the first threshold P3 is less than or equal to the first pressure parameter P1, i.e., whether P1-P2≥P3 holds true.

[0088] If the sum of the second pressure parameter P2 and the first threshold P3 is less than or equal to the first pressure parameter P1, the pressure regulating valve 52 is kept closed.

[0089] Receive mode switching command.

[0090] The pressure regulating valve 52 is opened for a first preset time t1.

[0091] Complete mode switching.

[0092] The statement that compressor 10 is in the off state means that the air conditioner 100 has just been turned on and has not yet switched modes, or that compressor 10 is in the process of switching modes.

[0093] When the compressor 10 is off, the pressure at the discharge port 12 and the return port 11 of the compressor 10 can be considered to be the same, that is, there is no pressure difference on both sides of the four-way valve 20.

[0094] At this time, a pressure difference can be formed between the high-pressure side and the low-pressure side of the compressor 10 through the cooperation of the pressure regulating tank 51 and the pressure regulating valve 52, so that the switching slider in the four-way valve 20 can stably achieve reversing through a suitable pressure difference force. The first threshold P3 can be in the range of 0.7-0.8 MPa. The first preset duration t1 can be 0.1-1 s, meaning that the pressure regulating tank 51 can replenish sufficient pressure to the refrigerant circuit in a very short time after connecting to the high-pressure side.

[0095] Thus, the first pressure parameter P1 inside the pressure regulating tank 51 and the second pressure parameter P2 at the return port 11 are first obtained. "When the compressor 10 is off" means that the compressor 10 of the air conditioner 100 has stopped running; at this time, the system is in a non-working or standby state, refrigerant circulation has stopped, and the system pressure is approaching or in the process of balancing. The first pressure parameter P1 is obtained through a first pressure sensor 54 installed inside the pressure regulating tank 51. This sensor monitors the pressure inside the pressure regulating tank 51 in real time and transmits the data to the control module 61. The second pressure parameter P2 is obtained through a second pressure sensor 62 installed at the return port 11. This sensor detects the low-pressure side pressure when the compressor 10 returns gas and transmits the data to the control module 61.

[0096] Then, it is determined whether the sum of the second pressure parameter P2 and the first threshold P3 (e.g., 0.7-0.8 MPa) is less than or equal to the first pressure parameter P1. This determination condition aims to evaluate the relative relationship between the pressure in the pressure regulating tank 51 and the low-pressure side pressure of the system. The first threshold P3 is used to ensure that the pressure in the pressure regulating tank 51 is relatively high, so that during mode switching, the high-pressure refrigerant supplied by the pressure regulating valve 52 can be directly used to ensure that the switching slider acting on the four-way valve 20 has an appropriate switching force. That is, the compressor 10 does not need to be started in advance during mode switching, which is beneficial to the stable operation of the air conditioning system.

[0097] Since the four-way valve 20 is initially in cooling mode, the heating mode switching command is typically issued by the user via the control panel or remote control, instructing the air conditioner 100 to switch from the current state to heating mode. Upon receiving the heating mode switching command, the control module 61 controls the pressure regulating valve 52 to open for a first preset time t1. This allows the high-pressure refrigerant in the pressure regulating tank 51 to be rapidly injected into the refrigerant circuit. By controlling the switching mode of the four-way valve 20, the pressure difference force drives the slider to switch from cooling to heating mode, allowing the refrigerant flowing from the exhaust port 12 to condense and release heat in the indoor heat exchanger 40, thus completing the mode switch. After the mode switch is complete, it indicates that the air conditioner 100 has successfully completed the transition from the off state to heating mode, and the compressor 10 can be started to enter normal heating operation. During the mode switch, the compressor 10 does not need to be started, significantly improving the smoothness, reliability, and efficiency of the air conditioner 100's mode switching, shortening the start-up time of the heating mode, and helping to extend the service life of system components, especially the compressor 10. In some embodiments, where the air conditioner includes a heating element 53 and the heating element 53 is disposed within the pressure regulating tank 51, reference continues to the following: Figure 4 The switching control method also includes the following steps: If the sum of the second pressure parameter P2 and the first threshold P3 is less than or equal to the first pressure parameter P1, the pressure regulating valve 52 and the heating element 53 are kept closed.

[0098] If the sum of the second pressure parameter P2 and the first threshold P3 is greater than the first pressure parameter, the pressure regulating valve 52 is closed, and the heating element 53 is activated for a second preset time t2. The first pressure parameter P1 and the second pressure parameter P2 are then re-detected and determined to ensure they meet the requirements.

[0099] The heating element 53 heats the refrigerant in the pressure regulating tank 51, thereby increasing the pressure inside the tank. The control module 61 is electrically connected to the heating element 53 and can precisely control its operation according to a preset control strategy, such as turning the heating element 53 on or off, or controlling the start-up time of the heating element 53.

[0100] When the sum of the second pressure parameter P2 and the first threshold P3 is less than or equal to the first pressure parameter P1, it indicates that the pressure state in the pressure regulating tank 51 meets the initial requirements for mode switching. At this time, the control module 61 controls the pressure regulating valve 52 and the heating element 53 to remain closed. The closure of the pressure regulating valve 52 ensures the isolation of the refrigerant circuit and prevents unnecessary refrigerant flow. The closure of the heating element 53 avoids unnecessary energy consumption and maintains the system in its current stable state. Subsequently, upon receiving a mode switching command, the control module 61 can open the pressure regulating valve 52 for a first preset time t1 and control the mode state of the four-way valve 20 to complete the mode switching without frequently starting the compressor.

[0101] However, if the sum of the second pressure parameter P2 and the first threshold P3 is greater than the first pressure parameter P1, it means that the pressure inside the pressure regulating tank 51 is relatively low and does not meet the initial conditions for mode switching. In this case, the control module 61 will control the pressure regulating valve 52 to remain closed, and simultaneously control the heating element 53 to operate for a second preset duration t2. By activating the heating element 53, the refrigerant inside the pressure regulating tank 51 is heated, and its temperature and pressure increase accordingly. The second preset duration t2 can be a fixed value or a value dynamically calculated based on the pressure difference to ensure that the pressure inside the pressure regulating tank 51 can be effectively increased. For example, the second preset duration t2 can be any duration between 10 and 300 seconds. After the heating element 53 has operated for the second preset duration t2, the system will re-detect and determine whether the first pressure parameter P1 and the second pressure parameter P2 meet the requirements.

[0102] Thus, when the system pressure does not meet the mode switching conditions, the heating element 53 inside the pressure regulating tank 51 can be activated quickly and effectively to increase the pressure inside the tank, bringing it to a state that meets the mode switching requirements. This avoids mode switching failure or inefficiency due to insufficient pressure, improving the success rate and stability of mode switching. Simultaneously, the re-detection and judgment mechanism ensures the effectiveness and timeliness of the heating process, preventing overheating or underheating, thereby optimizing energy utilization efficiency. Furthermore, through the above-mentioned mode switching control method, frequent starting of the compressor 10 is unnecessary, extending the service life of the compressor 10 and other equipment, enabling the air conditioner 100 to achieve smooth and reliable mode switching under a wider range of environmental conditions. Thirdly, embodiments of this application provide a mode switching control method for an air conditioner, used to control the air conditioner mentioned in the first aspect, such as... Figure 5 As shown, the mode switching control method includes the following steps: With compressor 10 in the on state.

[0103] Obtain the second pressure parameter P2 at the return air port 11, and obtain the fourth pressure parameter P4 at the exhaust port 12.

[0104] Determine whether the sum of the second pressure parameter P2 and the second threshold P5 is greater than the fourth pressure parameter P4.

[0105] If the sum of the second pressure parameter P2 and the second threshold P5 is less than or equal to the fourth pressure parameter P4 (i.e., P4-P2≥P5), the pressure regulating valve 52 is opened for a first preset time t1.

[0106] After a preset time, re-detect and determine whether the fourth pressure parameter P4 and the second pressure parameter P2 meet the requirements.

[0107] With compressor 10 on, i.e., air conditioner 100 is in heating mode, cooling mode, defrosting mode, or dehumidification mode, mode switching may be required, or mode switching may not be required during operation.

[0108] First, the second pressure parameter P2 at the return port 11 is acquired, and simultaneously, the fourth pressure parameter P4 at the exhaust port 12 is acquired. The second pressure parameter P2, detected by the second pressure sensor 62 located at the return port 11, reflects the pressure of the refrigerant drawn into the compressor 10, typically corresponding to the evaporation pressure or low-pressure side pressure. The fourth pressure parameter P4, detected by the third pressure sensor 63 located at the exhaust port 12, reflects the pressure of the refrigerant discharged from the compressor 10, typically corresponding to the condensation pressure or high-pressure side pressure. These pressure parameters are acquired in real time and transmitted to the control module 61 for processing, enabling the control module 61 to continuously monitor the compressor 10's workload and the system's refrigerant circulation status, providing a basis for subsequent pressure regulation.

[0109] The control module 61 determines, according to a preset program, whether the sum of the second pressure parameter P2 and the preset second threshold P5 is greater than the fourth pressure parameter P4 (i.e., whether P4 - P2 < P5 is true). This second threshold P5 is a crucial preset value, representing the maximum pressure difference range that should be maintained between the suction pressure and discharge pressure under normal operating conditions of the compressor 10. This pressure difference range can also be considered as the maximum pressure difference range for the four-way valve 20 to switch to stable mode. For example, the second threshold P5 has different value ranges under different configurations of the air conditioner 100.

[0110] Taking a variable frequency air conditioner using R410 refrigerant as an example, in heating mode, the pressure difference between suction and discharge pressure can range from 1.5 to 2.5 MPa; in cooling mode, the pressure difference can range from 1.2 to 2.0 MPa. Taking a variable frequency air conditioner using R32 refrigerant as an example, in heating mode, the pressure difference between suction and discharge pressure can range from 1.65 to 2.65 MPa; in cooling mode, the pressure difference can range from 1.35 to 2.1 MPa. Taking a variable frequency air conditioner using R290 refrigerant as an example, in heating mode, the pressure difference between suction and discharge pressure can range from 1.0 to 1.9 MPa; in cooling mode, the pressure difference can range from 0.75 to 1.55 MPa.

[0111] The second threshold P5 (i.e., the maximum differential pressure value) can be flexibly adapted between 1.7 and 3.0 MPa depending on the refrigerant and operating conditions. It is sufficient that the second threshold P5 under different operating conditions is recorded in the control module 61 before shipment; no specific limitation is imposed.

[0112] If the judgment result is that the sum of the second pressure parameter P2 and the second threshold P5 is less than or equal to the fourth pressure parameter P4, it indicates that the pressure difference between the high-pressure side and the low-pressure side of the system is high, which is not conducive to the stable operation of the system. Furthermore, due to the large pressure difference during the mode switching process, the four-way valve 20 will have a large sliding resistance and switching collision noise.

[0113] In this situation, the control module 61 will instruct the pressure regulating valve 52 to open for a first preset duration t1. The opening of the pressure regulating valve 52 allows some refrigerant in the high-pressure side flow path to flow into the pressure regulating tank 51, thereby reducing the refrigerant pressure on the high-pressure side. Simultaneously, it also replenishes some refrigerant into the pressure regulating tank 51 for backup. The first preset duration t1 can be 0.1-1s, meaning that the pressure regulating tank 51 can be replenished with sufficient pressure from the refrigerant circuit within a very short time after the high-pressure side is connected.

[0114] After the pressure regulating valve 52 is opened for a first preset time t1, and the air conditioning system has been running for 30-600 seconds (i.e., after the preset time), in order to verify the adjustment effect, the system will re-detect the fourth pressure parameter P4 and the second pressure parameter P2, and combine them with the second threshold P5 to repeatedly determine whether P4-P2<P5 is true, so as to ensure that the pressure adjustment reaches the expected target and prepare for subsequent operation or mode switching.

[0115] In addition, during the preset operation time, the air conditioner 100 can also adjust the operating power of the compressor 10 and the opening of the throttle valve 50 (such as the expansion valve) to reduce the pressure on the discharge side of the compressor 10 or increase the pressure on the suction side of the compressor 10, which is also beneficial to reduce the pressure difference range between the high and low pressure sides of the refrigerant circuit.

[0116] Through the above technical solution, this application can monitor and evaluate the pressure status of the refrigerant circulation in the system in real time during the operation of the compressor 10. When the pressure difference between the high and low pressure sides is detected to be higher than the expected range, by precisely controlling the opening duration of the pressure regulating valve 52, the refrigerant on the high-pressure side can be absorbed by the pressure regulating tank 51, thereby reducing the pressure difference between the high and low pressure sides. This effectively and dynamically adjusts the system pressure, thereby optimizing the distribution of refrigerant in the circuit, ensuring that the compressor 10 operates under more stable and efficient conditions, and providing a pressure difference environment suitable for the stable switching of the four-way valve 20 for subsequent mode switching adjustments. Continue to refer to Figure 5 The mode switching control method includes the following steps: If the sum of the second pressure parameter P2 and the second threshold P5 is greater than the fourth pressure parameter P4 (i.e., P4-P2<P5), determine whether the sum of the second pressure parameter P2 and the third threshold P6 is greater than the fourth pressure parameter P4 (i.e., whether P4-P2<P6 is true).

[0117] If the sum of the second pressure parameter P2 and the third threshold P6 is less than or equal to the fourth pressure parameter P4 (i.e., P5 > P4 - P2 ≥ P6), maintain the current operating state. After a preset time t0, re-detect and determine whether the fourth pressure parameter and the second pressure parameter meet the requirements.

[0118] Among them, the third threshold P6 is less than the second threshold P5.

[0119] The second threshold P5 (i.e., the maximum pressure difference value) can range from 1.7 to 3.0 MPa, and the third threshold P6 (i.e., the minimum pressure difference value) can range from 0.75 to 1.65 MPa. According to the above technical solution, when the pressure difference between the high and low pressure sides of the air conditioner 100 is detected to be between the third threshold P6 and the second threshold P5, it indicates that the air conditioner 100 is in a stable operating state. There is no need to adjust the air conditioner's operating mode through other means; simply maintain the current operating mode and, after 30-600 seconds, re-detect the refrigerant pressure on both sides of the compressor 10 and determine whether the pressure difference range between the high and low pressure sides meets the requirements.

[0120] Thus, through the above adjustments, the air conditioner 100 can maintain a stable operating state. When the four-way valve 20 needs to perform mode switching, the appropriate pressure difference range can reduce the wear of the internal moving parts of the four-way valve 20, extend its service life, and help improve the heat exchange efficiency and energy efficiency ratio of the air conditioner 100. The system can more intelligently respond to pressure fluctuations, adjusting only when intervention is truly needed, thereby optimizing the performance of the entire cooling or heating cycle. In some embodiments, the air conditioner 100 includes a heating element 53, and the heating element 53 is disposed within a pressure regulating tank 51. For example... Figure 5 As shown, the mode switching control method also includes the following steps: If the sum of the second pressure parameter P2 and the third threshold P6 is greater than the fourth pressure parameter P4 (i.e., P4 - P2 < P6), obtain the first pressure parameter P1 inside the pressure regulating tank 51 and obtain the second pressure parameter P2 at the return air port 11.

[0121] Determine whether the sum of the second pressure parameter P2 and the first threshold P3 is less than or equal to the first pressure parameter P1 (i.e., whether P1-P2≥P3 holds true).

[0122] If the sum of the second pressure parameter P2 and the first threshold P3 is less than or equal to the first pressure parameter P1 (i.e., P1-P2≥P3), the pressure regulating valve 52 and the heating element 53 are kept closed.

[0123] Receive mode switching command.

[0124] The compressor 10 is shut down, the pressure regulating valve 52 is opened for a first preset time t1, and the four-way valve 20 is switched.

[0125] If the sum of the second pressure parameter P2 and the third threshold P6 is greater than the fourth pressure parameter P4, the air conditioning system is in a low-pressure condition, and there is a small pressure difference between the exhaust and suction sides of the compressor 10. In this case, it is necessary to further detect the first pressure parameter P1 in the pressure regulating tank 51 and the second pressure parameter P2 at the return port 11, and determine whether P1-P2≥P3 is satisfied. Alternatively, it is also possible to simultaneously compare whether P4-P2≥P3 holds true.

[0126] If the sum of the second pressure parameter P2 and the first threshold P3 is less than or equal to the first pressure parameter P1, it indicates that the pressure difference between the refrigerant pressure in the pressure regulating tank 51 and the low-pressure side is sufficient to meet the pressure difference required for stable switching of the four-way valve 20. In this case, it is only necessary to keep the pressure regulating valve 52 and the heating element 53 closed. Subsequently, after receiving the mode switching command, the compressor 10 can be shut down, the pressure regulating valve 52 can be opened for a first preset time t1, and the four-way valve 20 can be switched to complete the mode switching command stably and smoothly.

[0127] Alternatively, if the sum of the second pressure parameter P2 and the first threshold P3 is less than or equal to the fourth pressure parameter P4, it indicates that the pressure difference between the refrigerant pressure on the high-pressure side and the low-pressure side is sufficient to meet the pressure difference required for stable switching of the four-way valve 20. In this case, it is only necessary to keep the pressure regulating valve 52 and the heating element 53 closed. Subsequently, after receiving the mode switching command, the compressor 10 can be shut down, and then the four-way valve 20 can be switched to complete the mode switching command smoothly and stably.

[0128] In some embodiments, continue to refer to Figure 5 In determining whether P1-P2≥P3 holds true, the mode switching control method also includes the following steps: If the sum of the second pressure parameter P2 and the first threshold P3 is greater than the first pressure parameter P1 (i.e., P1-P2<P3), the pressure regulating valve 52 is closed, and the heating element 53 is activated for a second preset time t2. The data is then re-collected and it is determined whether P1-P2≥P3 is true.

[0129] Alternatively, if the sum of the second pressure parameter P2 and the first threshold P3 is greater than the fourth pressure parameter P4 (i.e., P4 - P2 < P3), and the sum of the second pressure parameter P2 and the first threshold P3 is greater than the first pressure parameter P1 (i.e., P1 - P2 < P3), then the pressure regulating valve 52 is closed, and the heating element 53 is activated for a second preset time t2. The data is then re-acquired and a determination is made as to whether P4 - P2 ≥ P3 is true.

[0130] Since the sum of the second pressure parameter P2 and the first threshold P3 is greater than the first pressure parameter P1, it indicates that the pressure difference between the refrigerant pressure in the pressure regulating tank 51 and the low-pressure side is insufficient for the four-way valve 20 to smoothly complete the mode switching operation. At this time, it is necessary to control the pressure regulating valve 52 to close and control the heating element 53 to open for a second preset time t2 to heat the refrigerant in the pressure regulating tank 51, so that more refrigerant vaporizes and the refrigerant pressure in the pressure regulating tank 51 is increased through heating. After heating for the second preset time t2 (10-300s), the first pressure parameter P1 and the second pressure parameter P2 can be re-checked and judged to see if the requirements are met. That is, whether P1-P2≥P3 is true. If true, the subsequent mode switching operation can be completed; otherwise, reheating continues. This forms a closed-loop pressure regulation process.

[0131] This method ensures that the internal pressure of the system reaches a more balanced and stable state before mode switching, avoiding situations such as switching failure of the four-way valve 20 due to pressure imbalance, thus significantly improving the stability, reliability, and safety of the air conditioner 100 during mode switching. During this mode switching process, it is only necessary to detect and compare the relationship between the second pressure parameter P2, the first pressure parameter P1, and the first threshold P3 to ensure that the high-pressure refrigerant in the pressure regulating tank 51 is compatible with the low-pressure condition of the four-way valve 20 during switching, which simplifies the control logic.

[0132] Alternatively, if the sum of the second pressure parameter P2 and the first threshold P3 is greater than the fourth pressure parameter P4 (i.e., P4 - P2 < P3), it indicates that the pressure difference between the high-pressure side and the low-pressure side of the compressor 10 is insufficient for the four-way valve 20 to smoothly complete the mode switching operation. In this case, it is necessary to further determine whether the refrigerant pressure in the pressure regulating tank 51 can meet the switching requirements of the four-way valve 20. If the sum of the second pressure parameter P2 and the first threshold P3 is greater than the first pressure parameter P1 (i.e., P1 - P2 < P3), then...

[0133] Then, it is necessary to control the pressure regulating valve 52 to close and control the heating element 53 to open for a second preset time t2 to heat the refrigerant in the pressure regulating tank 51, so that more refrigerant is vaporized and the refrigerant pressure in the pressure regulating tank 51 is increased by heating. After heating for the second preset time t2 (10-300s), the first pressure parameter P1 and the second pressure parameter P2 can be re-checked and judged to see if the requirements are met. That is, whether P1-P2≥P3 is true. If true, the subsequent mode switching operation can be completed; otherwise, reheating continues. This forms a closed-loop pressure regulation process.

[0134] In this way, the pressure balance regulation of the refrigerant system can be further optimized, thereby improving the stability, reliability and safety of the air conditioner 100 during mode switching.

[0135] Fourthly, embodiments of this application provide a mode switching control method for an air conditioner, used to control the air conditioner mentioned in the first aspect, such as... Figure 6 As shown, the mode switching control method includes the following steps: During the defrosting process of the air conditioner at 100°C.

[0136] Obtain the inlet water temperature T of the indoor heat exchanger 40, and obtain the fourth pressure parameter P4 at the exhaust port 12.

[0137] Determine whether the inlet water temperature T is less than the temperature threshold T1 and the fourth pressure parameter P4 is less than the fourth threshold P7 (i.e., whether T < T1 and P4 < P7).

[0138] If the inlet water temperature T is less than the temperature threshold T1, and the fourth pressure parameter P4 is less than the fourth threshold P7 (i.e., T < T1 and P4 < P7), the pressure regulating valve 52 is closed and the current operating state is maintained.

[0139] During the defrosting process of the air conditioner 100, the control module 61 of the air conditioner 100 determines that the defrosting cycle has been completed, for example by detecting that the outdoor heat exchanger 30 temperature has reached a preset value or the defrosting time has reached a preset value. This is also the operating state of the air conditioner 100 when switching to the heating mode. At this time, heat exchange occurs between the indoor heat exchanger 40 and the indoor unit through the circulation of coolant.

[0140] The inlet water temperature T of the indoor heat exchanger 40 can be detected by a temperature sensor located near the liquid inlet end of the indoor heat exchanger 40. For example, the air conditioner 100 may include a temperature sensor 64, which is located at the inlet end of the second heat exchange channel 42 to detect the inlet water temperature T of the second heat exchange channel 42, and the temperature sensor 64 is electrically connected to the control module 61. This allows the control module 61 to monitor the above two parameters in real time through the third pressure sensor 63 and the temperature sensor 64.

[0141] The control module 61 can also determine whether the above-mentioned inlet water temperature T and fourth pressure parameter P4 meet the requirements based on the temperature threshold T1 (e.g., 33-38℃) and the fourth threshold P7 (e.g., 1.5-2.0MPa). When the inlet water temperature T is less than the temperature threshold T1 and the fourth pressure parameter P4 is less than the fourth threshold P7 (i.e., T < T1 and P4 < P7), the inlet water temperature T of the indoor heat exchanger 40 is lower, which is conducive to the rapid liquefaction of the refrigerant under heating conditions. The corresponding pressure value on the discharge side of the compressor 10 is lower, providing sufficient pressure boost redundancy after switching to heating conditions, thereby avoiding the situation where the air conditioner high-pressure side pressure rises rapidly to exceed the threshold after switching from defrosting mode to heating mode.

[0142] At this time, the heating element 53 and the pressure regulating valve 52 are kept closed. In the subsequent process, the mode switching control method described in the third aspect can be continued to stably switch the air conditioner 100 from defrosting mode to heating mode, maintaining the system refrigerant circulation within the normal range. This avoids problems such as excessive system pressure fluctuations or poor heating performance. This intelligent control strategy ensures that the air conditioner 100 can safely, stably, and efficiently resume heating mode and normal operation after defrosting, significantly improving system reliability and user experience. In some embodiments, where the air conditioner 100 includes a heating element 53, and the heating element 53 is disposed within a pressure regulating tank 51, such as Figure 6 As shown, the mode switching control method also includes the following steps: If the inlet water temperature T is less than the temperature threshold T1, and the fourth pressure parameter P4 is less than the fourth threshold P7, then the pressure regulating valve 52 and the heating element 53 are kept closed.

[0143] If the inlet water temperature T is less than the temperature threshold T1, and the fourth pressure parameter P4 is less than the fourth threshold P7, then the pressure regulating valve 52 is controlled to open for a first preset time t1, and the heating element 53 is controlled to remain closed.

[0144] When the control module 61 determines that the inlet water temperature T is less than the temperature threshold T1 and the fourth pressure parameter P4 is less than the fourth threshold P7 (i.e., T≥T1, P4≥P7 or both are true at the same time).

[0145] During defrosting, the higher inlet water temperature T allows the liquid refrigerant at the indoor heat exchanger 40 to fully absorb heat from the circulating water and evaporate. At this time, because the compressor 10 operates at low frequency, a significant amount of gaseous refrigerant accumulates on its suction side (i.e., the suction pressure is higher). When the air conditioner 100 switches to heating mode and the compressor 10 operates at high frequency, the higher pressure of the gaseous refrigerant on the suction side is rapidly compressed and discharged by the compressor 10, causing a rapid increase in pressure on the discharge side of the compressor 10, thus affecting the system pressure balance.

[0146] Correspondingly, during defrosting, the compressor 10 operates at a low frequency and has a high pressure on the exhaust side. When the air conditioner 100 switches to heating mode and the compressor 10 operates at a high frequency, it can quickly absorb the gaseous refrigerant in the indoor heat exchanger 40, compress it, and discharge it, further increasing the pressure on the exhaust side. This will cause the refrigerant pressure on the exhaust side to rise rapidly, thereby affecting the system pressure balance.

[0147] Based on this, when the inlet water temperature T is less than the temperature threshold T1, and the fourth pressure parameter P4 is less than the fourth threshold P7 (i.e., T < T1 and P4 < P7), sufficient pressure boosting redundancy is provided for subsequent switching to heating mode, allowing the heating element 53 and pressure regulating valve 52 to remain closed. Furthermore, in the subsequent process, the mode switching control method described in the third aspect can be continued to stably switch the air conditioner 100 from defrosting mode to heating mode, maintaining the system refrigerant circulation within the normal range.

[0148] If the inlet water temperature T is greater than or equal to the temperature threshold T1, and the fourth pressure parameter P4 is greater than or equal to the fourth threshold P7, at least one of the above two conditions must be met. This necessitates addressing the issue of a rapid increase in exhaust pressure in advance. Based on this, the pressure regulating valve 52 can be controlled to open for a first preset time t1, while the heating element 53 remains closed. This allows the pressure regulating tank 51 to absorb and accommodate a portion of the refrigerant on the high-pressure side, thereby reducing the refrigerant pressure on the high-pressure side and increasing the pressure boost redundancy. Subsequently, the mode switching control method described in the third aspect can be executed to stably switch the air conditioner 100 from defrosting mode to heating mode, while maintaining the system refrigerant circulation within the normal range.

[0149] This enables the four-way valve 20 to reliably and smoothly complete mode switching under various complex operating conditions, especially in scenarios where high pressure surges during low-temperature heating start-up or heating defrosting reversal, significantly improving the operational stability and reliability of the air conditioner 100.

[0150] Fifthly, such as Figure 7 As shown in the figure, this application embodiment provides a control device for a heating, ventilation, and air purification system, namely a control module 61. The control module includes a processor 611, a communication interface 612, a memory 613, and a communication bus 614. The processor 611, communication interface 612, and memory 613 communicate with each other via the communication bus 614. The memory 613 is used to store computer programs.

[0151] In one embodiment of this application, when the processor 611 executes the computer program stored in the memory 613, it implements the execution steps of the mode switching control method for the air conditioner in the second, third and fourth aspects.

[0152] This application also provides a computer-readable storage medium storing a computer program thereon, which, when executed by a processor, implements the execution steps of the mode switching control method for the air conditioner in the second, third, and fourth aspects.

[0153] It should be understood that the terminology used herein is for the purpose of describing particular exemplary embodiments only and is not intended to be limiting. Unless the context clearly indicates otherwise, the singular forms “a,” “an,” and “described” as used herein may also include the plural forms. The terms “comprising,” “including,” “containing,” and “having” are inclusive and therefore indicate the presence of the stated features, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, elements, components, and / or combinations thereof. The method steps, processes, and operations described herein are not construed as requiring them to be performed in a particular order described or illustrated unless the order of performance is explicitly indicated. It should also be understood that additional or alternative steps may be used.

[0154] Although terms such as first, second, third, etc., may be used in this document to describe multiple elements, components, regions, layers, and / or segments, these elements, components, regions, layers, and / or segments should not be limited by these terms. These terms may be used only to distinguish one element, component, region, layer, or segment from another. Unless the context clearly indicates otherwise, terms such as "first," "second," and other numerical terms used herein do not imply order or sequence. Therefore, the first element, component, region, layer, or segment discussed below may be referred to as the second element, component, region, layer, or segment without departing from the teachings of the exemplary embodiments.

[0155] The above description is merely a specific embodiment of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. An air conditioner, characterized in that, include: The compressor has a return port and an exhaust port; The four-way valve has four ports, with the return port connected to the first port of the four-way valve and the exhaust port connected to the second port of the four-way valve. Pressure regulating tank; An outdoor heat exchanger, one end of which is connected to the third port of the four-way valve via the pressure regulating tank; Throttling device; The indoor heat exchanger, with the other end of the outdoor heat exchanger connected in sequence to the fourth port of the four-way valve via the throttle and the indoor heat exchanger; And a pressure regulating valve, between the third port and the outdoor heat exchanger, the pressure regulating tank is connected to the refrigerant circuit via the pressure regulating valve.

2. The air conditioner according to claim 1, characterized in that, The air conditioner includes: A first pressure sensor is installed inside the pressure regulating tank to detect a first pressure parameter inside the pressure regulating tank. Control module; A second pressure sensor is provided at the return port to detect a second pressure parameter when the compressor returns air; the compressor, the four-way valve, the pressure regulating valve, the first pressure sensor, and the second pressure sensor are electrically connected to the control module.

3. The air conditioner according to claim 2, characterized in that, The air conditioner includes: A heating element is disposed inside the pressure regulating tank, and a control module is electrically connected to the heating element to control the operating status of the heating element.

4. The air conditioner according to claim 2, characterized in that, The air conditioner includes: A third pressure sensor is located at the exhaust port and is used to detect a fourth pressure parameter when the compressor is discharging. The third pressure sensor is electrically connected to the control module.

5. The air conditioner according to any one of claims 2-4, characterized in that, The indoor heat exchanger includes a first heat exchange channel and a second heat exchange channel; the first heat exchange channel and the second heat exchange channel are isolated from each other and used for heat exchange; the first heat exchange channel is connected between the fourth port and the throttle. The air conditioner also includes a temperature sensor, which is located at the inlet end of the second heat exchange channel and is used to detect the inlet water temperature of the second heat exchange channel. The temperature sensor is electrically connected to the control module.

6. A mode switching control method for an air conditioner, used to control the air conditioner as described in any one of claims 1-5, characterized in that, The mode switching control method includes: When the compressor is in the off state; Obtain the first pressure parameter inside the pressure regulating tank, and obtain the second pressure parameter at the return air port; Determine whether the sum of the second pressure parameter and the first threshold is less than or equal to the first pressure parameter; If the sum of the second pressure parameter and the first threshold is less than or equal to the first pressure parameter, the pressure regulating valve is controlled to remain closed. Receive mode switching command; The pressure regulating valve is controlled to open for a first preset time and the four-way valve is switched. Complete mode switching.

7. The mode switching control method for an air conditioner according to claim 6, characterized in that, When the air conditioner includes a heating element, and the heating element is disposed within the pressure regulating tank, the mode switching control method includes: If the sum of the second pressure parameter and the first threshold is less than or equal to the first pressure parameter, the pressure regulating valve and the heating element are kept closed. If the sum of the second pressure parameter and the first threshold is greater than the first pressure parameter, control the pressure regulating valve to close and control the heating element to be turned on for a second preset time; re-detect and determine whether the first pressure parameter and the second pressure parameter meet the requirements.

8. A mode switching control method for an air conditioner, used to control the air conditioner as described in any one of claims 1-5, characterized in that, The mode switching control method includes: When the compressor is in the on state; Obtain the second pressure parameter at the return port and the fourth pressure parameter at the exhaust port; Determine whether the sum of the second pressure parameter and the second threshold is greater than the fourth pressure parameter; If the sum of the second pressure parameter and the second threshold is less than or equal to the fourth pressure parameter, the pressure regulating valve is controlled to open for a first preset duration; After a preset time, the fourth pressure parameter and the second pressure parameter are re-detected and it is determined whether they meet the requirements.

9. The mode switching control method for an air conditioner according to claim 8, characterized in that, The mode switching control method includes: If the sum of the second pressure parameter and the second threshold is greater than the fourth pressure parameter, determine whether the sum of the second pressure parameter and the third threshold is greater than or equal to the fourth pressure parameter; If the sum of the second pressure parameter and the third threshold is less than the fourth pressure parameter, maintain the current operating state; after a first preset time, re-detect and determine whether the fourth pressure parameter and the second pressure parameter meet the requirements; The third threshold is less than the second threshold.

10. The mode switching control method for an air conditioner according to claim 9, characterized in that, When the air conditioner includes a heating element, and the heating element is disposed within the pressure regulating tank, the mode switching control method includes: If the sum of the second pressure parameter and the third threshold is greater than the fourth pressure parameter; obtain the first pressure parameter inside the pressure regulating tank, and obtain the second pressure parameter at the return air port; Determine whether the sum of the second pressure parameter and the first threshold is less than or equal to the first pressure parameter; If the sum of the second pressure parameter and the first threshold is less than or equal to the first pressure parameter, the pressure regulating valve and the heating element are kept closed. Receive mode switching command; The compressor is shut down, the pressure regulating valve is opened for a first preset time, and the four-way valve is switched.

11. The mode switching control method for an air conditioner according to claim 10, characterized in that, The mode switching control method includes: If the sum of the second pressure parameter and the first threshold is greater than the first pressure parameter, control the pressure regulating valve to close and control the heating element to be turned on for a second preset time; re-detect and determine whether the first pressure parameter and the second pressure parameter meet the requirements.

12. A mode switching control method for an air conditioner, used to control the air conditioner as described in any one of claims 1-5, characterized in that, The mode switching control method includes: During the process of the air conditioner ending defrost mode; Obtain the inlet water temperature of the indoor heat exchanger and obtain the fourth pressure parameter at the exhaust port; Determine whether the following conditions are met: the inlet water temperature is less than the temperature threshold and the fourth pressure parameter is less than the fourth threshold. If the inlet water temperature is less than the temperature threshold and the fourth pressure parameter is less than the fourth threshold, the pressure regulating valve is controlled to close and the current operating state is maintained.

13. The mode switching control method for an air conditioner according to claim 12, characterized in that, When the air conditioner includes a heating element, and the heating element is disposed within the pressure regulating tank, the mode switching control method includes: If the inlet water temperature is less than the temperature threshold and the fourth pressure parameter is less than the fourth threshold, then the pressure regulating valve and the heating element are controlled to remain closed. If the inlet water temperature is less than the temperature threshold and the fourth pressure parameter is less than the fourth threshold (which is not true), then the pressure regulating valve is controlled to open for a first preset time, and the heating element is controlled to remain closed.

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