Air conditioner and air conditioner control method

Abstract

The invention relates to an air conditioner and an air conditioner control method, and relates to the technical field of air conditioners. The air conditioner comprises a refrigerant circulation loop, a first temperature sensor, a first pressure sensor, a second temperature sensor and a controller. Wherein the controller is configured to start the compressor to run to the initial working frequency in response to a starting signal, and start the expansion valve to run to the initial opening degree matched with the current external environment temperature; the compressor is controlled to continue to run according to the first increment frequency, the expansion valve continues to run according to the second increment frequency matched with the current external environment temperature, the first pressure sensor is controlled to periodically detect the first pressure in the running process, and the second temperature sensor is controlled to periodically detect the suction temperature; according to the pressure change condition and the low-pressure temperature difference condition, an operation adjustment strategy is determined; and according to the operation adjustment strategy, operation control is conducted on the working frequency of the compressor and / or the valve opening degree of the expansion valve, and therefore the starting speed of the system is increased.

Description

Technical Field

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

[0002] Air conditioning refrigerant is a crucial component of the air conditioning refrigeration cycle. It plays a role in heat transfer, mass transfer, and energy transmission, carrying out the refrigeration cycle through chemical reactions to ultimately lower the indoor temperature. R32 refrigerant (difluoromethane) has become the mainstream choice for air conditioning refrigerants due to its high energy efficiency and low cost. With the advancement of policies related to the coordinated governance of ozone layer protection and climate change, R290 refrigerant (propane), due to its lower Global Warming Potential (GWP), is considered a better alternative to R32.

[0003] However, because R290 refrigerant is flammable and explosive, in order to meet safety and reliability requirements, the air conditioner's pressure and temperature changes are usually strictly monitored during startup and operation. This results in a slow startup, making it difficult to maintain a constant indoor temperature quickly.

[0004] Therefore, while ensuring the safe startup of air conditioners, improving their startup speed is an urgent problem to be solved. Summary of the Invention

[0005] This application provides an air conditioner and an air conditioner control method to improve the start-up speed of the air conditioner.

[0006] In a first aspect, some embodiments provide an air conditioner, including:

[0007] Refrigerant circulation loop, first temperature sensor, first pressure sensor, second temperature sensor and controller;

[0008] The refrigerant circulation loop includes a compressor, a first heat exchanger, an expansion valve, a second heat exchanger, and a four-way valve connected in sequence.

[0009] The first heat exchanger is configured to exchange heat with outdoor air;

[0010] The compressor is configured to compress refrigerant from a low-pressure state to a high-pressure state and drive the refrigerant to circulate within the refrigerant circulation loop.

[0011] An expansion valve is configured to regulate the flow rate of refrigerant in the refrigerant circulation loop;

[0012] The second heat exchanger, connected to the water circulation loop, is configured to achieve heat exchange between the water and the refrigerant in the water circulation loop; the four-way valve is configured to switch the operating mode of the air conditioner; the operating modes include cooling mode and heating mode.

[0013] The first temperature sensor is used to detect the external ambient temperature;

[0014] The first pressure sensor is used to detect the first pressure on the low-pressure side of the air conditioner.

[0015] The second temperature sensor is used to detect the suction temperature at the compressor's suction port;

[0016] The controller is configured as follows:

[0017] In response to the start signal, the compressor is started to run at the initial operating frequency, the current external ambient temperature is obtained, and the expansion valve is started to run to the initial opening degree that matches the current external ambient temperature;

[0018] The compressor is controlled to operate at a first incremental frequency, and the expansion valve continues to operate at a second incremental frequency that matches the current external ambient temperature. During operation, the first pressure sensor is controlled to periodically detect the first pressure on the low-pressure side of the air conditioner, and the second temperature sensor is controlled to periodically detect the suction temperature at the suction port.

[0019] Based on the pressure change of the first pressure at different detection times, and the low-pressure temperature difference between the intake temperature and the saturation temperature corresponding to the first pressure, the operation adjustment strategy is determined.

[0020] Based on the operational adjustment strategy, the operating frequency of the compressor and / or the valve opening of the expansion valve are controlled.

[0021] In some embodiments, the controller responds to the start signal by starting the compressor to its initial operating frequency and starting the expansion valve to its initial opening degree that matches the current external ambient temperature. During operation, a dynamic detection mode is adopted to gradually adjust the compressor's operating frequency and / or the expansion valve's opening degree while maintaining normal system operation. The above-mentioned starting method, which starts the compressor at a low frequency and then gradually adjusts the compressor's operating frequency, eliminates the need to detect parameters such as the air conditioner's pressure and temperature changes, compared to the traditional method of starting only after passing the detection process. This eliminates the detection step and allows the compressor to quickly reach its target operating frequency and target exhaust temperature, thus improving the system's start-up speed.

[0022] Secondly, some embodiments also provide an air conditioner control method, including:

[0023] In response to the start signal, the air conditioner's compressor is started to run at the initial operating frequency, the current external ambient temperature is obtained, and the air conditioner's expansion valve is started to run at an initial opening degree that matches the current external ambient temperature;

[0024] The compressor is controlled to operate at a first incremental frequency, and the expansion valve continues to operate at a second incremental frequency that matches the current external ambient temperature. During operation, the first pressure sensor of the air conditioner is controlled to periodically detect the first pressure on the low-pressure side of the air conditioner, and the second temperature sensor of the air conditioner is controlled to periodically detect the suction temperature at the air intake of the air conditioner.

[0025] Based on the pressure change of the first pressure at different detection times, and the low-pressure temperature difference between the intake temperature and the saturation temperature corresponding to the first pressure, the operation adjustment strategy is determined.

[0026] Based on the operational adjustment strategy, the operating frequency of the compressor and / or the valve opening of the expansion valve are controlled.

[0027] In some embodiments, in response to a start signal, the compressor is started to operate at its initial operating frequency, and the expansion valve is started to operate at its initial opening degree that matches the current external ambient temperature. During operation, a dynamic detection mode is adopted to gradually adjust the compressor's operating frequency and / or the expansion valve's opening degree while maintaining normal system operation. The above-mentioned start-up method, which starts the compressor at a low frequency and then gradually adjusts the compressor's operating frequency, eliminates the need to detect parameters such as pressure and temperature changes of the air conditioner, compared to the traditional start-up method that requires a pass test before starting. This eliminates the need to detect the test steps and allows the compressor to quickly reach its target operating frequency and target exhaust temperature, thus improving the system's start-up speed.

[0028] Thirdly, some embodiments also provide an air conditioner control device, including:

[0029] The start-up module is used to respond to the start-up signal, start the air conditioner's compressor to run to the initial operating frequency, obtain the current external ambient temperature, and start the air conditioner's expansion valve to run to the initial opening degree that matches the current external ambient temperature;

[0030] The first control module is used to control the compressor to continue operating at a first incremental frequency and the expansion valve to continue operating at a second incremental frequency that matches the current external ambient temperature. During operation, the first pressure sensor of the air conditioner periodically detects the first pressure on the low-pressure side of the air conditioner, and the second temperature sensor of the air conditioner periodically detects the suction temperature at the air intake of the air conditioner.

[0031] The first determining module is used to determine the operation adjustment strategy based on the pressure change of the first pressure at different detection times and the low-pressure temperature difference between the intake temperature and the saturation temperature corresponding to the first pressure.

[0032] The second control module is used to control the operating frequency of the compressor and / or the valve opening of the expansion valve according to the operation adjustment strategy.

[0033] In some embodiments, the start-up module responds to the start-up signal by starting the compressor to its initial operating frequency and starting the expansion valve to its initial opening degree that matches the current external ambient temperature. During operation, a dynamic detection mode is adopted to gradually adjust the compressor's operating frequency and / or the expansion valve's opening degree while maintaining normal system operation. The above-mentioned start-up method, which starts the compressor at a low frequency and then gradually adjusts the compressor's operating frequency, eliminates the need to detect parameters such as the air conditioner's pressure and temperature changes, compared to the traditional start-up method that requires a pass test before starting. This eliminates the need to detect the test steps and allows the compressor to quickly reach its target operating frequency and target exhaust temperature, thus improving the system's start-up speed.

[0034] Fourthly, some embodiments also provide a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the methods provided in some embodiments of the third or fourth aspect.

[0035] Fifthly, some embodiments also provide a computer program product, including a computer program that, when executed by a processor, implements the steps of the methods provided in some embodiments of the third or fourth aspect. Attached Figure Description

[0036] 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, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0037] Figure 1 This application provides schematic diagrams of the structure of an air conditioner according to some embodiments;

[0038] Figure 2 Schematic diagrams of air conditioner operation in cooling mode provided in some embodiments of this application;

[0039] Figure 3 A schematic diagram of an air conditioner operating in heating mode provided in some embodiments of this application;

[0040] Figure 4 A schematic flowchart illustrating a first air conditioning control method provided in some embodiments of this application;

[0041] Figure 5 A flowchart illustrating the steps for determining the operational adjustment strategy provided in some embodiments of this application;

[0042] Figure 6A flowchart illustrating a second air conditioning control method provided in some embodiments of this application;

[0043] Figure 7 A flowchart illustrating a third air conditioning control method provided in some embodiments of this application;

[0044] Figure 8 A flowchart illustrating the steps for controlling and increasing the operating frequency of the compressor as provided in some embodiments of this application;

[0045] Figure 9 A flowchart illustrating the steps for controlling and reducing the operating frequency of the compressor as provided in some embodiments of this application;

[0046] Figure 10 A flowchart illustrating a fourth air conditioning control method provided in some embodiments of this application;

[0047] Figure 11 A flowchart illustrating a fifth air conditioning control method provided in some embodiments of this application;

[0048] Figure 12 A flowchart illustrating a sixth air conditioning control method provided in some embodiments of this application;

[0049] Figure 13 A flowchart illustrating a seventh air conditioning control method provided in some embodiments of this application;

[0050] Figure 14 A flowchart illustrating an eighth air conditioning control method provided in some embodiments of this application;

[0051] Figure 15 Structural block diagrams of air conditioner control devices provided in some embodiments of this application;

[0052] Figure 16 This is an internal structural diagram of a computer device in one embodiment. Detailed Implementation

[0053] The embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described below do not represent all embodiments consistent with this application. They are merely examples of systems and methods consistent with some aspects of this application as detailed in the claims.

[0054] It should be noted that the brief descriptions of terms in this application are only for the convenience of understanding the embodiments described below, and are not intended to limit the embodiments of this application. Unless otherwise stated, these terms should be understood in their ordinary and common meaning.

[0055] The terms "first," "second," "third," etc., used in the specification, claims, and accompanying drawings of this application are used to distinguish similar or related objects or entities, and do not necessarily imply a specific order or sequence, unless otherwise specified. It should be understood that such terms are interchangeable where appropriate.

[0056] The terms “include” and “have”, and any variations thereof, are intended to cover but not exclusively include, for example, a product or device that includes a range of components is not necessarily limited to all of the components that are clearly listed, but may include other components that are not clearly listed or that are inherent to such product or device.

[0057] The term "module" refers to any known or subsequently developed hardware, software, firmware, artificial intelligence, fuzzy logic, or combination of hardware and / or software code that is capable of performing the functions associated with that element.

[0058] Please see Figure 1 This is a structural block diagram of an air conditioner provided in some embodiments of the present invention. Figure 1 The air conditioner 1 shown includes a refrigerant circulation loop 11, a first temperature sensor 12, a first pressure sensor 13, a second temperature sensor 14, and a controller 15.

[0059] The refrigerant circulation loop 11 is configured to circulate the refrigerant in order to achieve the cooling or heating function of the air conditioner 1.

[0060] Optional, such as Figure 1 As shown, the refrigerant circulation loop 11 includes a compressor 111, a first heat exchanger 112, an expansion valve 113, a second heat exchanger 114, and a four-way valve 115 connected in sequence.

[0061] The first heat exchanger 112 is configured to exchange heat with outdoor air.

[0062] The compressor 111 is configured to compress the refrigerant from a low-pressure state to a high-pressure state and drive the refrigerant to circulate within the refrigerant circulation loop 11.

[0063] Expansion valve 113 is configured to regulate the flow rate of refrigerant in refrigerant circulation loop 11.

[0064] The second heat exchanger 114 is connected to the water circulation loop and is configured to realize heat exchange between the water and the refrigerant in the water circulation loop.

[0065] The four-way valve 115 is configured to switch the operating mode of the air conditioner 1; the operating modes include cooling mode and heating mode.

[0066] The first temperature sensor 12 is used to detect the external ambient temperature.

[0067] The first pressure sensor 13 is used to detect the first pressure on the low-pressure side of the air conditioner 1.

[0068] The second temperature sensor 14 is used to detect the suction temperature of the compressor 111.

[0069] Please see Figure 2 This is a schematic diagram of an air conditioner operating in a cooling mode according to some embodiments of the present invention. When the first heat exchanger of the air conditioner cools the indoor environment, it functions as a condenser, releasing heat; the second heat exchanger functions as an evaporator, absorbing heat. The refrigerant is compressed by the compressor into a high-temperature, high-pressure gas; it flows into the first heat exchanger to release heat and condense into a liquid (or gas, or a gas-liquid mixture); then, after being throttled and depressurized by the expansion valve, it flows into the second heat exchanger, where it absorbs heat from the water medium in the water circulation system (endothermics) and evaporates into a gas; finally, it flows back into the compressor, completing a complete refrigerant circulation loop, thereby achieving indoor cooling.

[0070] Please see Figure 3 This is a schematic diagram of an air conditioner operating in a heating mode according to some embodiments of the present invention. When the first heat exchanger of the air conditioner heats the indoor environment, it functions as an evaporator, absorbing heat; the second heat exchanger functions as a condenser, releasing heat. The refrigerant is compressed by the compressor into a high-temperature, high-pressure gas. After its flow direction is changed by a four-way valve, it flows into the second heat exchanger, where it exchanges heat (releases heat) with the low-temperature water medium in the water circulation system, condensing into a liquid (or gas, or a gas-liquid mixture). Then, after being throttled and depressurized by the expansion valve, it flows back into the first heat exchanger to absorb heat and evaporate into a gas. Finally, it flows back into the compressor, completing a complete refrigerant circulation loop, thereby achieving indoor heating. During this process, the water circulation system heats the water medium in the second heat exchanger with the heat released therein, releasing heat into the room.

[0071] R290 refrigerant is considered a better alternative to R32 due to its lower Global Warming Potential (GWP). However, because R290 is flammable and explosive, to meet safety and reliability requirements, the original R32 start-up control logic typically performs strict checks on parameters such as pressure and temperature changes in the air conditioner during startup. Only after passing these checks can the next step be taken. Therefore, systems using R290 refrigerant experience a slow increase in compressor operating frequency, slow changes in water and room temperature, and poor temperature comfort. Furthermore, after a protective shutdown in extreme temperature environments, restarting exacerbates the slow startup problem, making it difficult to maintain a constant indoor temperature. This results in a slow startup and difficulty in quickly maintaining a constant indoor temperature.

[0072] In some alternative embodiments, see Figure 4 An air conditioner control method is provided for use in a controller of an air conditioner 1, comprising:

[0073] S410, in response to the start signal, starts the air conditioner compressor 111 to run to the initial operating frequency, obtains the current external ambient temperature, and starts the air conditioner expansion valve to run to the initial opening degree that matches the current external ambient temperature.

[0074] The start signal can be understood as a signal sent by the indoor unit of air conditioner 1 to the outdoor unit to start the compressor 111 of air conditioner 1. Specifically, the start signal can include a signal to start the compressor 111 of air conditioner 1 to achieve cooling and / or a signal to start the compressor 111 of air conditioner 1 to achieve heating. In cooling mode, the start signal is the signal to start the compressor 111 of air conditioner 1 to achieve cooling, i.e., the cooling start signal. In heating mode, the start signal is the signal to start the compressor 111 of air conditioner 1 to achieve heating, i.e., the heating start signal.

[0075] The initial operating frequency can be understood as the basic operating frequency set by the compressor 111 at startup. Optionally, the basic operating frequency can be any of a preset value, an experimental value, or an empirical value. Optionally, the initial operating frequency is different in different operating modes. For example, in cooling mode, the initial operating frequency can be 20Hz; in heating mode, the initial operating frequency can be 30Hz. Alternatively, the initial operating frequency can be the same in different operating modes.

[0076] Here, the current external ambient temperature can be understood as the external ambient temperature detected by the first temperature sensor at the current moment during the startup process of compressor 111.

[0077] The initial opening degree can be understood as the degree to which the valve inside the expansion valve is open.

[0078] In some embodiments, starting the expansion valve of the air conditioner 1 to operate at an initial opening degree that matches the current external ambient temperature may include: determining an initial opening degree that matches the external ambient temperature range where the current external ambient temperature is located based on the initial opening degree corresponding to each external ambient temperature range and the current external ambient dimension; and starting the expansion valve of the air conditioner 1 to operate at an initial opening degree that matches the external ambient temperature range where the current external ambient temperature is located.

[0079] Optionally, the initial opening degree corresponding to each external ambient temperature range can be any of a preset value, an experimental value, or an empirical value. For example, setting the external ambient temperature as Ta, in cooling mode, when the external ambient temperature range is Ta ≤ 30℃, the initial opening degree can be 10%; when the external ambient temperature range is 30℃ < Ta ≤ 40℃, the initial opening degree can be 12%; and when the external ambient temperature range is 40℃ < Ta, the initial opening degree can be 16%. In heating mode, when the external ambient temperature range is Ta ≤ -10℃, the initial opening degree can be 10%; when the external ambient temperature range is -10℃ < Ta ≤ 5℃, the initial opening degree can be 12%; and when the external ambient temperature range is 5℃ < Ta, the initial opening degree can be 14%.

[0080] S420, the compressor 111 is controlled to operate at a first incremental frequency, and the expansion valve continues to operate at a second incremental frequency that matches the current external ambient temperature. During operation, the first pressure sensor is controlled to periodically detect the first pressure on the low-pressure side of the air conditioner, and the second temperature sensor is controlled to periodically detect the suction temperature at the suction port.

[0081] The first incremental frequency can be understood as the change in operating frequency per unit time. The second incremental frequency can be understood as the change in opening degree per unit time.

[0082] Optionally, the first increment frequency can be a preset fixed increment frequency. For example, the first increment frequency can be 1Hz increasing every 2 seconds.

[0083] Optionally, the second increment frequency can be an increment frequency that matches the current ambient temperature range.

[0084] In some embodiments, controlling the expansion valve to continue operating at a second incremental frequency that matches the current external ambient temperature may include: determining a second incremental frequency that matches the external ambient temperature range where the current external ambient temperature is located, based on the second incremental frequency corresponding to each external ambient temperature range and the current external ambient temperature; and controlling the expansion valve to continue operating at the second incremental frequency that matches the external ambient temperature range where the current external ambient temperature is located.

[0085] Optionally, the second incremental frequency corresponding to each external ambient temperature range can be any of a preset value, an experimental value, or an empirical value. For example, setting the external ambient temperature as Ta, in cooling mode, when the external ambient temperature range is Ta ≤ 30℃, the second incremental frequency can increase by 1% every 2 seconds; when the external ambient temperature range is 30℃ < Ta ≤ 40℃, the second incremental frequency can increase by 1.5% every 2 seconds; and when the external ambient temperature range is 40℃ < Ta, the second incremental frequency can increase by 2% every 2 seconds. In heating mode, when the external ambient temperature range is Ta ≤ -10℃, the second incremental frequency can increase by 1% every 2 seconds; when the external ambient temperature range is -10℃ < Ta ≤ 5℃, the second incremental frequency can increase by 1.5% every 2 seconds; and when the external ambient temperature range is 5℃ < Ta, the second incremental frequency can increase by 2% every 2 seconds.

[0086] In some embodiments, during operation, the first pressure sensor can be controlled to detect the first pressure on the low-pressure side of the air conditioner 1 according to a first cycle, and the second temperature sensor can detect the intake temperature at the intake port according to a second cycle. Optionally, the first cycle and the second cycle can be the same.

[0087] S430 determines the operation adjustment strategy based on the pressure change of the first pressure at different detection times and the low-pressure temperature difference between the intake temperature and the saturation temperature corresponding to the first pressure.

[0088] The first pressure can be understood as the pressure value of the pipeline between the suction port of compressor 111 and the expansion valve.

[0089] The pressure change can be understood as the change of the first pressure over time. Optionally, the pressure change may include at least one of the pressure change rate and the pressure change acceleration.

[0090] The suction temperature can be understood as the suction temperature at the suction port of compressor 111.

[0091] The saturation temperature corresponding to the first pressure can be understood as the temperature at which gas-liquid equilibrium (i.e., saturation) is achieved under the first pressure on the low-pressure side. Optionally, the saturation temperature corresponding to the first pressure can be obtained by looking up a table.

[0092] Optionally, the low-pressure temperature difference situation can include the low-pressure temperature difference value.

[0093] The operation adjustment strategy can be understood as a strategy for adjusting the operating frequency of the compressor 111 and / or the valve opening of the expansion valve. Optionally, the operation adjustment strategy may include whether to adjust the operating frequency of the compressor 111 and / or the valve opening of the expansion valve, and the adjustment amount during adjustment.

[0094] S440, based on the operation adjustment strategy, performs operation control on the operating frequency of compressor 111 and / or the valve opening of expansion valve.

[0095] In one alternative implementation, when controlling the operating frequency of the compressor 111, the operating frequency of the compressor 111 can be controlled until the target operating frequency is reached. When controlling the valve opening of the expansion valve, the exhaust temperature at the exhaust port can be controlled until the target exhaust temperature is reached.

[0096] In the above-mentioned air conditioner control method, in response to the start signal, the compressor 111 is started to run to the initial operating frequency, and the expansion valve is started to run to the initial opening degree that matches the current external ambient temperature. During operation, a dynamic detection mode is adopted. While maintaining the normal operation of the system, the operating frequency of the compressor 111 and / or the valve opening degree of the expansion valve are gradually adjusted. The above-mentioned starting method of starting the compressor 111 at a low frequency first and then gradually adjusting the operating frequency of the compressor 111, compared with the traditional method of starting after passing the test during the start process, does not require the detection of parameters such as pressure and temperature changes of the air conditioner 1, thus eliminating the detection step. In this way, the target operating frequency and target exhaust temperature of the compressor 111 can be quickly reached, improving the start-up speed of the system.

[0097] Based on the technical solutions of the above embodiments, in some embodiments, the steps for determining the operation adjustment strategy have been refined.

[0098] See Figure 5 The steps for determining the operational adjustment strategy shown include:

[0099] S 510, if the pressure change and low-pressure temperature difference meet the first condition, the operation adjustment strategy is determined to be to maintain the compressor's operating frequency from rising for the first time and then restore the original operating mode.

[0100] The first condition is that the rate of change and acceleration of change of the first pressure are both less than 0 for a preset continuous period of time, and the low-pressure temperature difference is less than the first temperature difference threshold.

[0101] Understandably, when the pressure change and low-pressure temperature difference meet the first condition (i.e., the rate of change and acceleration of the first pressure change are both less than 0 for a preset continuous duration, and the low-pressure temperature difference is less than the first temperature difference threshold), the first pressure on the low-pressure side of the air conditioner 1 is decreasing rapidly without overheating and at risk of liquid return. The corresponding operation adjustment strategy is to maintain the compressor 111's operating frequency from rising for the first time and then restore the original operating mode. This can be understood as follows: First, the compressor 111's operating frequency is prohibited from rising, and the compressor 111 is controlled to operate at the current operating frequency for the first time, for example, the compressor 111's operating frequency is prohibited from rising for 10 seconds. Then, the process returns to step S420 until the compressor 111's operating frequency reaches the target operating frequency or the shutdown fault protection is activated.

[0102] S520, when the pressure change and low-pressure temperature difference meet the second condition, determines the operation adjustment strategy as follows: when the first pressure is greater than the preset protection pressure, maintain the current operation mode, and when the first pressure is not greater than the preset protection pressure, execute pressure protection.

[0103] The second condition is that the rate of change of the first pressure is less than 0, and the acceleration of the change is not less than 0.

[0104] It is understandable that when the pressure change and low-pressure temperature difference meet the second condition, that is, when the rate of change of the first pressure is less than 0 and the acceleration of change is not less than 0, the first pressure on the low-pressure side of the air conditioner 1 decreases at a deceleration or uniform rate. The corresponding operation adjustment strategy is to maintain the current operation mode when the first pressure is greater than the preset protection pressure, and to execute pressure protection when the first pressure is not greater than the preset protection pressure. This can be understood as: when the first pressure is greater than the preset protection pressure, the steps of S420 continue to be executed; when the first pressure is not greater than the preset protection pressure, pressure protection is executed.

[0105] S530, when the pressure change and low-pressure temperature difference meet the third condition, the operation adjustment strategy is determined to keep the compressor's operating frequency from rising during the first time period, and to continuously increase the valve opening of the expansion valve according to the first preset frequency and the first adjustment range during the second time period.

[0106] The third condition is that the rate of change of the first pressure is not less than 0 for a preset continuous duration, and the low-pressure temperature difference value is not less than the second temperature difference threshold.

[0107] Understandably, when the pressure change and low-pressure temperature difference meet the third condition—that is, when the rate of change of the first pressure is not less than 0 for a preset continuous duration and the low-pressure temperature difference is not less than the second temperature difference threshold—the suction temperature is rising, and the first pressure on the low-pressure side of the air conditioner 1 drops too much. The corresponding operational adjustment strategy, namely, to prevent the compressor 111 from increasing its operating frequency in the first time period and to continuously increase the valve opening of the expansion valve according to the first preset frequency and the first adjustment range in the second time period, can be understood as: preventing the compressor 111 from increasing its operating frequency and controlling the compressor 111 to operate at the current operating frequency in the first time period, for example, controlling the compressor 111's operating frequency to be prevented from increasing for 10 seconds; and continuously increasing the valve opening of the expansion valve according to the first preset frequency and the first adjustment range in the second time period, for example, controlling the valve opening of the expansion valve to increase by 2% per second for 5 seconds.

[0108] The above embodiments, by adopting corresponding operation adjustment strategies under different conditions of pressure change and low-pressure temperature difference, can precisely control the operating frequency of compressor 111 and / or the valve opening of expansion valve, thereby improving the system start-up speed.

[0109] Based on the technical solutions of the above embodiments, in some embodiments, the air conditioner 1 is further provided with a third temperature sensor, configured to detect the exhaust temperature at the exhaust port, such as... Figure 6 The air conditioner control method shown also includes:

[0110] S610, when the frequency difference between the current operating frequency of compressor 111 and the target operating frequency corresponding to the current external ambient temperature is less than a preset frequency threshold, a valve step adjustment strategy is determined based on the difference in exhaust temperature between the current exhaust temperature and the target exhaust temperature.

[0111] The target operating frequency corresponding to the current external ambient temperature can be understood as the operating frequency that the compressor 111 needs to achieve under the current external ambient temperature.

[0112] In some embodiments, the frequency difference between the current operating frequency of the compressor 111 and the target operating frequency corresponding to the current external ambient temperature can be obtained by the following steps: determining the target operating frequency corresponding to the external ambient temperature range where the current external ambient temperature is located based on the current external ambient temperature and the target operating frequency corresponding to each external ambient temperature range; calculating the frequency difference between the current operating frequency of the compressor 111 and the target operating frequency corresponding to the external ambient temperature range where the current external ambient temperature is located.

[0113] For example, in cooling mode, the target operating frequency corresponding to each external ambient temperature range can be as shown in Table 1.

[0114] Table 1

[0115]

[0116] In Table 1, Ta represents the external ambient temperature. Among them, F1 represents the preset value when the external ambient temperature is Ta≤20℃; Fmax1 represents the preset value when the external ambient temperature is 30℃<Ta≤40℃; Fmax2 represents the preset value when the external ambient temperature is 40℃<Ta≤45℃; and F2 represents the preset value when the external ambient temperature is 50℃<Ta.

[0117] It is understandable that the target operating frequencies corresponding to each external ambient temperature range in Table 1 are only illustrative.

[0118] For example, in heating mode, the target operating frequency corresponding to each external ambient temperature range can be shown in Table 2.

[0119] Table 2

[0120]

[0121] In Table 2, Ta represents the external ambient temperature. Among them, F1′ represents the preset value when the external ambient temperature is Ta≤-20℃; Fmax1′ represents the preset value when the external ambient temperature is -5℃<Ta≤5℃; Fmax2′ represents the preset value when the external ambient temperature is 5℃<Ta≤15℃; and F2′ represents the preset value when the external ambient temperature is 30℃<Ta.

[0122] It is understandable that the target operating frequencies corresponding to each external ambient temperature range in Table 2 are only illustrative.

[0123] It is understandable that if the frequency difference between the current operating frequency of compressor 111 and the target operating frequency corresponding to the current external ambient temperature is less than the preset frequency threshold, it can be considered that the current operating frequency of compressor 111 is close to the target operating frequency. At this time, the valve step of the expansion valve can be adjusted so that the current operating frequency of compressor 111 reaches the target operating frequency and the current exhaust temperature reaches the target exhaust temperature.

[0124] The target exhaust temperature can be understood as the exhaust temperature that matches the current external ambient temperature. In some embodiments, the target exhaust temperature corresponding to the current external ambient temperature range can be determined based on the current external ambient temperature and the target exhaust temperature corresponding to each external ambient temperature range.

[0125] For example, in cooling mode, the target exhaust temperature corresponding to each external ambient temperature range can be as shown in Table 3.

[0126] Table 3

[0127]

[0128] In Table 3, Ta represents the ambient temperature. Tc represents the saturation temperature corresponding to the exhaust pressure at the time of the last test. a represents the temperature value obtained based on the intake temperature at the time of the last test and the first coefficient (e.g., 0.5); b represents the temperature value obtained based on the intake temperature at the time of the last test and the second coefficient (e.g., 0.6).

[0129] It is understood that the target exhaust temperatures corresponding to each external ambient temperature range in Table 3 are only illustrative. The target exhaust temperatures corresponding to each external ambient temperature range can be any of the preset values, experimental values, or empirical values.

[0130] Understandably, when the intake temperature is too low (e.g., negative), the target exhaust temperature will rise; conversely, when the intake temperature rises, the target exhaust temperature will decrease accordingly. When the intake temperature is positive, the higher the intake temperature, the lower the target exhaust temperature. The target exhaust temperatures corresponding to the various external ambient temperature ranges set above can prevent pressure overshoot and excessive intake overheating caused by excessively small openings.

[0131] For example, in heating mode, the target exhaust temperature corresponding to each external ambient temperature range can be shown in Table 4.

[0132] Table 4

[0133]

[0134] In Table 4, Ta represents the ambient temperature. Tc represents the saturation temperature, i.e., the condensation temperature, corresponding to the exhaust pressure at the time of the last test. a represents the temperature value obtained based on the intake temperature at the time of the last test and the first coefficient (e.g., 0.5); b represents the temperature value obtained based on the intake temperature at the time of the last test and the second coefficient (e.g., 0.6).

[0135] It is understood that the target exhaust temperatures corresponding to each external ambient temperature range in Table 4 are only illustrative. The target exhaust temperatures corresponding to each external ambient temperature range can be any of the preset values, experimental values, or empirical values.

[0136] In some embodiments, determining a valve step adjustment strategy based on the exhaust temperature difference between the current exhaust temperature and the target exhaust temperature may include: if the exhaust temperature difference between the current exhaust temperature and the target exhaust temperature decreases to a first temperature difference range, determining the valve step adjustment strategy to reduce the current valve step of the expansion valve; if the exhaust temperature difference between the current exhaust temperature and the target exhaust temperature decreases from the first temperature difference range to a second temperature difference range, or increases from the second temperature difference range to a third temperature difference range, determining the valve step adjustment strategy to maintain the current valve step of the expansion valve; if the exhaust temperature difference between the current exhaust temperature and the target exhaust temperature exceeds the third temperature difference range, re-acquiring the target exhaust temperature corresponding to the current external ambient temperature and the current exhaust temperature to redetermine the valve step adjustment strategy.

[0137] Here, valve step can be understood as the rate of change of the opening degree of the expansion valve.

[0138] The exhaust temperature difference between the current exhaust temperature and the target exhaust temperature can be understood as the absolute value of the exhaust temperature difference between the current exhaust temperature and the target exhaust temperature.

[0139] It is understandable that the second temperature difference range is smaller than the first temperature difference range; the second temperature difference range is smaller than the third temperature difference range.

[0140] The situation where the exhaust temperature difference between the current exhaust temperature and the target exhaust temperature narrows to within the first temperature difference range can be understood as: the current exhaust temperature is close to the target exhaust temperature. In this case, the current valve step of the expansion valve can be reduced to decrease the rate of change of the expansion valve's opening, thereby achieving precise adjustment of the current exhaust temperature to reach the target exhaust temperature. Therefore, the valve step adjustment strategy can be determined as reducing the current valve step of the expansion valve. For example, the valve step adjustment strategy can be determined as adjusting the current valve step of the expansion valve to 25% of its original value.

[0141] Among them, the situation where the exhaust temperature between the current exhaust temperature and the target exhaust temperature decreases from the first temperature difference range to the second temperature difference range, and the situation where the exhaust temperature between the current exhaust temperature and the target exhaust temperature increases from the second temperature difference range to the third temperature value range, can be understood as follows: when the current exhaust temperature reaches the target exhaust temperature, the current valve step of the expansion valve is no longer adjusted. Therefore, it can be determined that the valve step adjustment strategy is to maintain the current valve step of the expansion valve.

[0142] In the case where the exhaust temperature difference between the current exhaust temperature and the target exhaust temperature exceeds the third temperature difference range, it can be understood that the current exhaust temperature is far from the target exhaust temperature. In this case, the current exhaust temperature needs to be readjusted to reach the target exhaust temperature. Therefore, the target exhaust temperature corresponding to the current external ambient temperature and the current exhaust temperature can be obtained again, and the valve step adjustment strategy can be re-determined based on the exhaust temperature difference between the current exhaust temperature and the target exhaust temperature.

[0143] S620 controls the valve opening of the expansion valve according to the valve step adjustment strategy.

[0144] In one alternative implementation, when controlling the valve opening of the expansion valve, the current exhaust temperature can be controlled until the target exhaust temperature is reached.

[0145] In the above embodiments, when the exhaust temperature difference between the current exhaust temperature and the target exhaust temperature is reduced to the first temperature difference range, it can be considered that the current exhaust temperature is close to the target exhaust temperature. At this time, the current valve step of the expansion valve can be reduced so that the opening change rate of the expansion valve is reduced, thereby achieving precise adjustment of the current exhaust temperature to reach the target exhaust temperature.

[0146] Based on the technical solutions of the above embodiments, in some embodiments, see [reference needed]. Figure 7 The air conditioner control method shown also includes:

[0147] S710 controls and increases the operating frequency of the compressor when the valve opening of the expansion valve is adjusted to the lower limit of the valve opening.

[0148] S720 controls and reduces the operating frequency of the compressor when the valve opening of the expansion valve is adjusted to the upper limit of the valve opening.

[0149] It is understood that the lower limit and upper limit of valve opening can be set according to actual needs. For example, the lower limit of valve opening can be 5%, and the upper limit of valve opening can be 100%.

[0150] It is understandable that when the expansion valve opening is adjusted to the lower limit, the operating frequency of the compressor 111 is increased; when the expansion valve opening is adjusted to the upper limit, the operating frequency of the compressor 111 is decreased, thereby adjusting the current exhaust temperature to achieve the target exhaust temperature.

[0151] In the above embodiment, when the operating frequency of the compressor 111 is close to the target operating frequency, the valve step adjustment strategy is determined by the difference between the current exhaust temperature and the target exhaust temperature, and the valve opening of the expansion valve is controlled. This can quickly adjust the current exhaust temperature to the target exhaust temperature, so as to quickly complete the system startup process.

[0152] Based on the technical solutions of the above embodiments, in some embodiments, the steps for controlling and increasing the operating frequency of the compressor 111 have been refined.

[0153] like Figure 8 The steps shown for controlling and increasing the operating frequency of compressor 111 include:

[0154] S810, adjust the operating frequency of compressor 111 according to the first preset frequency amplitude.

[0155] The first preset frequency amplitude can be understood as the adjustment amount of the working frequency.

[0156] S820, when the exhaust temperature difference between the current exhaust temperature and the target exhaust temperature exceeds the fourth temperature difference threshold, the operating frequency of the compressor 111 is increased again according to the first preset frequency amplitude, and the operating frequency of the compressor 111 is kept from increasing.

[0157] It is understandable that if the temperature difference between the current exhaust temperature and the target exhaust temperature exceeds the fourth temperature difference threshold, the difference between the current exhaust temperature and the target exhaust temperature is large. In this case, the operating frequency of the compressor 111 can be increased again according to the first preset frequency range, and then the operating frequency of the compressor 111 should not be adjusted again to avoid causing other problems.

[0158] In the above embodiments, when the valve opening of the expansion valve is adjusted to the lower limit of the valve opening, the operating frequency of the compressor 111 is gradually adjusted to precisely adjust the current front exhaust temperature to reach the target exhaust temperature while avoiding causing other problems.

[0159] Based on the technical solutions of the above embodiments, in some embodiments, the steps of controlling and reducing the operating frequency of the compressor 111 have been refined.

[0160] like Figure 9 The steps shown for controlling and reducing the operating frequency of compressor 111 include:

[0161] S910, adjust the operating frequency of compressor 111 to be reduced according to the second preset frequency amplitude.

[0162] The second preset frequency amplitude can be understood as the adjustment amount of the working frequency.

[0163] S920, when the temperature difference between the current exhaust temperature and the target exhaust temperature exceeds the fourth temperature difference threshold, the operating frequency of the compressor 111 is reduced again according to the second preset frequency amplitude, and the operating frequency of the compressor 111 is kept unchanged.

[0164] It is understandable that when the temperature difference between the current exhaust temperature and the target exhaust temperature exceeds the fourth temperature difference threshold, the difference between the current exhaust temperature and the target exhaust temperature is large. In this case, the operating frequency of the compressor 111 can be reduced again according to the second preset frequency amplitude, and then the operating frequency of the compressor 111 should not be adjusted again to avoid causing other problems.

[0165] In the above embodiments, when the valve opening of the expansion valve is adjusted to the upper limit of the valve opening, the operating frequency of the compressor 111 is gradually adjusted to precisely adjust the current front exhaust temperature to reach the target exhaust temperature while avoiding causing other problems.

[0166] Based on the technical solutions of the above embodiments, in some embodiments, the air conditioner 1 is further provided with a fourth temperature sensor, configured to detect the inlet water temperature of the second heat exchanger inlet, such as... Figure 10 The air conditioner control method shown also includes:

[0167] S1010: When the difference between the current external ambient temperature and the current inlet water temperature is greater than the circulating water temperature difference threshold, and the start signal is a cooling start signal, the four-way valve is controlled to switch to heating operation. After the first heating operation duration, the four-way valve is controlled to switch to cooling operation.

[0168] Among them, the circulating water temperature difference threshold can be understood as the temperature difference threshold between the external ambient temperature and the inlet water temperature.

[0169] The four-way valve can be used to switch the air conditioner 1 between cooling mode and heating mode by changing the direction of refrigerant flow.

[0170] S1020: When the difference between the current inlet water temperature and the current external ambient temperature is greater than the circulating water temperature difference threshold, and the start signal is the heating start signal, the air conditioner is controlled to run in cooling mode for the second time, and then the four-way valve is controlled to switch to heating mode.

[0171] Among them, the water ring temperature difference threshold can be understood as the temperature difference threshold between the inlet water temperature and the external ambient temperature.

[0172] In the above embodiments, in the cooling mode, by first controlling the four-way valve to switch to heating operation for a first duration and then controlling the four-way valve to switch to cooling operation, and in the heating mode, by first controlling the four-way valve to switch to cooling operation for a second duration and then controlling the four-way valve to switch to heating operation, it is possible to prevent a large amount of refrigerant from being drawn into the compressor 111 during the intake process, thus preventing liquid return.

[0173] Based on the technical solutions of the above embodiments, in some embodiments, the air conditioner further includes: a third temperature sensor configured to detect the exhaust temperature at the exhaust port; and a fourth temperature sensor configured to detect the inlet water temperature at the inlet of the second heat exchanger; such as Figure 11 The air conditioning control method shown also includes:

[0174] S1110: When the current exhaust temperature is close to the first exhaust temperature threshold, the air conditioner is in cooling operation, the currently set demand water temperature exceeds the first temperature difference between the current inlet water temperature and the current exhaust temperature is less than the first upper temperature threshold and no longer rises, the expansion valve is controlled to maintain the current valve step, and the compressor is controlled to maintain the current working efficiency.

[0175] The statement that the current exhaust temperature is close to the first exhaust temperature threshold can be understood as the current exhaust temperature being at a relatively high level, such as close to 90°C. In this case, the current valve step of the expansion valve can be controlled and adjusted based on the difference between the current exhaust temperature and the first exhaust temperature threshold, as well as the difference between the currently set required water temperature and the current inlet water temperature.

[0176] S1120: When the current exhaust temperature is close to the first exhaust temperature threshold, the air conditioner is in heating mode, the currently set demand water temperature is lower than the first temperature difference between the current inlet water temperature and the current exhaust temperature rises to exceed the preset temperature range, the current valve step of the expansion valve is controlled and adjusted according to the current exhaust temperature and the preset temperature range until the demand water temperature is lower than the second temperature difference between the current inlet water temperature and the current exhaust temperature is less than the lower limit of the preset temperature range.

[0177] In this context, "the currently set demand water temperature exceeds the current inlet water temperature by a first temperature difference" can be understood as the currently set demand water temperature being higher than the current inlet water temperature, and the difference between the currently set demand water temperature and the current inlet water temperature being greater than the first temperature difference. For example, the currently set demand water temperature is more than 10°C higher than the current inlet water temperature.

[0178] Understandably, during cooling operation, if the currently set demand water temperature exceeds the first temperature difference between the current inlet water temperature and the current exhaust temperature is close to the first exhaust temperature threshold and is less than the first upper temperature threshold and no longer rising, for example, if the currently set demand water temperature is more than 10°C higher than the current inlet water temperature and the current exhaust temperature is maintained below 95°C and no longer rising, it is necessary to maintain the low pressure on the low-pressure side of the air conditioner 1 at a certain value and the evaporation temperature at a certain value. At this time, the expansion valve can be controlled to maintain the current valve step, and the compressor 111 can maintain the current working efficiency.

[0179] The condition that the currently set demand water temperature is lower than the current inlet water temperature by a first temperature difference can be understood as the current set demand water temperature being lower than the current inlet water temperature, and the difference between the current inlet water temperature and the currently set demand water temperature being greater than the first temperature difference. For example, the current set demand water temperature is more than 10°C lower than the current inlet water temperature.

[0180] Understandably, during heating operation, if the currently set demand water temperature is lower than the first temperature difference between the current inlet water temperature and the current exhaust temperature is close to the first exhaust temperature threshold and rises above the preset temperature range (e.g., the currently set demand water temperature is more than 10°C lower than the current inlet water temperature and the current exhaust temperature rises above 100°C to 103°C), the current valve step of the expansion valve is controlled and adjusted until the demand water temperature is lower than the second temperature difference between the current inlet water temperature and the current exhaust temperature is less than the lower limit of the preset temperature range. Optionally, the second temperature difference can be less than the first temperature difference; for example, the first temperature difference can be 10°C and the second temperature difference can be 5°C. It is understood that the preset temperature range can be understood as the allowable temperature range after the current exhaust temperature rises, for example, allowing the current exhaust temperature to rise to 100°C to 103°C. In some embodiments, if the current exhaust temperature rises above the first exhaust temperature threshold but below the lower limit of the preset temperature range, the valve step of the expansion valve is reduced. In some embodiments, if the current exhaust temperature rises above the upper limit of the preset temperature range, the valve step of the expansion valve is increased.

[0181] In some embodiments, the air conditioner 1 is further provided with a second pressure sensor, which is configured to detect the exhaust pressure of the exhaust pipe in the air conditioner 1. When controlling the adjustment of the current valve step of the expansion valve according to the current exhaust temperature and the preset temperature range, the current valve step of the expansion valve can be reduced when the current exhaust temperature is less than the lower limit of the preset temperature range; and the current valve step of the expansion valve can be increased when the current exhaust temperature is greater than the upper limit of the preset temperature range.

[0182] In the above embodiments, by controlling the current valve step of the expansion valve to be reduced when the current exhaust temperature is lower than the lower limit of the preset temperature range, and by controlling the current valve step of the expansion valve to be increased when the current exhaust temperature is higher than the upper limit of the preset temperature range, the inlet water temperature can be precisely adjusted.

[0183] In the above embodiments, when the current exhaust temperature is close to the first exhaust temperature threshold, the current valve step of the expansion valve is adjusted according to the difference between the current inlet water temperature and the set required water temperature, and the current exhaust temperature can be adjusted to quickly reach the target exhaust temperature.

[0184] Based on the technical solutions of the above embodiments, in some embodiments, the above air conditioner control method further includes: when the current exhaust pressure is greater than the first pressure difference of the system shutdown pressure, controlling the reduction of the operating frequency of the compressor 111 and prohibiting the reduction of the valve opening of the expansion valve; when the current exhaust pressure is greater than the second pressure difference of the system shutdown pressure for a third duration, reducing the operating frequency of the compressor 111 again.

[0185] The current exhaust pressure can be understood as the high pressure on the exhaust pipe.

[0186] The system shutdown pressure can be understood as the final stable state value of the internal pressure after the system stops running.

[0187] The first pressure difference, where the current exhaust pressure is greater than the system shutdown pressure, can be understood as the current exhaust pressure being greater than the system shutdown pressure, and the pressure difference between the current exhaust pressure and the system shutdown pressure being the first pressure difference.

[0188] The second pressure difference, where the current exhaust pressure is greater than the system shutdown pressure, can be understood as the current exhaust pressure being greater than the system shutdown pressure, and the pressure difference between the current exhaust pressure and the system shutdown pressure being the second pressure value.

[0189] Optionally, the second pressure difference can be smaller than the first pressure difference.

[0190] Understandably, if the current discharge pressure is greater than the first pressure difference of the system shutdown pressure, the current discharge pressure is too high. In this case, the current discharge pressure can be reduced by decreasing the operating frequency of compressor 111, but the opening of the expansion valve must be maintained. If the current discharge pressure remains higher than the second pressure difference of the system shutdown pressure for a third period, the current discharge pressure is still relatively high. Therefore, the current discharge pressure can be reduced again by decreasing the operating frequency of compressor 111. In some embodiments, if the current discharge pressure is greater than the first pressure difference of the system shutdown pressure, the operating frequency of compressor 111 can be reduced by a first frequency value, for example, by 5Hz; if the current discharge pressure is greater than the second pressure difference of the system shutdown pressure for a third period, the operating frequency of compressor 111 can be reduced again by a first frequency value, for example, by another 5Hz.

[0191] In the above embodiments, by adjusting the operating frequency of the compressor 111 according to the difference between the current exhaust pressure and the system shutdown pressure, the current exhaust pressure of the exhaust pipe can be reduced so that the system can operate in a normal state.

[0192] Based on the technical solutions of the above embodiments, in some embodiments, the air conditioner 1 is further provided with a third temperature sensor, configured to detect the exhaust temperature of the exhaust port; the outdoor fan is configured to drive outdoor air through the first heat exchanger by rotation, so that the refrigerant exchanges heat with the outdoor air, such as... Figure 12 The air conditioner control method shown also includes:

[0193] S1210, determine the current exhaust temperature difference between the target exhaust temperature corresponding to the current external ambient temperature and the current exhaust temperature.

[0194] In some embodiments, the exhaust temperature at the exhaust port can be detected by a third temperature sensor installed in the air conditioner 1 to obtain the current exhaust temperature.

[0195] S1220: When the current exhaust temperature is lower than the target exhaust temperature, based on the speed adjustment lookup table, look up the speed adjustment method that matches the start signal, the current valve opening of the expansion valve, and the current exhaust temperature difference.

[0196] It is understood that the current operating frequency of compressor 111 has reached the target operating frequency, and the fan speed, target exhaust temperature, and expansion valve opening are related. The speed adjustment method is used to adjust the current fan speed to assist the expansion valve in quickly raising the current exhaust temperature to the target exhaust temperature. For example, the speed adjustment method may include at least one of maintaining the current speed, increasing the current speed by a preset amount, or decreasing the current speed by a preset amount.

[0197] Understandably, the current exhaust temperature difference can be used to determine whether the subcooling of the condenser side is sufficient during refrigeration operation or whether the superheat of the evaporator side is sufficient during heating operation; adjusting the current fan speed based on the current valve opening of the expansion valve can prevent excessive system load under certain special operating conditions.

[0198] Understandably, the speed adjustment lookup table stores speed adjustment methods that match the start signal, the current valve opening of the expansion valve, and the current exhaust temperature.

[0199] For example, under the refrigeration start signal, the current valve opening of each expansion valve and the speed adjustment method corresponding to each current exhaust temperature difference are shown in Table 5.

[0200] Table 5

[0201]

[0202] In Table 5, K1 represents the current valve opening of the expansion valve; Tdo represents the target exhaust temperature; Td represents the current exhaust temperature; and Tdo-Td represents the current exhaust temperature difference between the target exhaust temperature and the current exhaust temperature. Taking K1≤15% and 5℃≤Tdo-Td<15℃ as an example, the corresponding speed adjustment method is to reduce the current fan speed by 30 rpm.

[0203] For example, under the heating start signal, the current valve opening of each expansion valve and the speed adjustment method corresponding to each current exhaust temperature difference are shown in Table 6.

[0204] Table 6

[0205]

[0206] In Table 6, K1 represents the current valve opening of the expansion valve; Tdo represents the target exhaust temperature; Td represents the current exhaust temperature; and Tdo-Td represents the current exhaust temperature difference between the target exhaust temperature and the current exhaust temperature. Taking K1≤10% and 15℃≤Tdo-Td<25℃ as an example, the corresponding speed adjustment method is to increase the current fan speed by 10 rpm.

[0207] S1230 controls the current speed of the fan according to the speed adjustment method; wherein, the initial speed of the fan is obtained by querying the initial speed table based on the start signal, the current external ambient temperature and the currently set required water temperature.

[0208] In some embodiments, the current speed of the fan is controlled according to the speed adjustment method so that the current exhaust temperature can quickly reach the target exhaust temperature.

[0209] In some embodiments, in the cooling operation mode, the initial speed of the fan is obtained by querying the initial speed table based on the cooling start signal, the current external ambient temperature, and the currently set required water temperature.

[0210] For example, the initial tachometer is shown in Table 7.

[0211] Table 7

[0212]

[0213] In Table 7, Ta represents the external ambient temperature; ΔT represents the absolute value of the temperature difference between the set required water temperature and the current inlet water temperature.

[0214] In some embodiments, in heating operation mode, the initial speed of the fan is obtained by querying the initial speed table based on the heating start signal, the current external ambient temperature, and the currently set required water temperature.

[0215] For example, the initial tachometer is shown in Table 8.

[0216] Table 8

[0217]

[0218] In Table 8, Ta represents the external ambient temperature; ΔT represents the absolute value of the temperature difference between the set required water temperature and the current inlet water temperature.

[0219] In the above embodiments, the current exhaust temperature difference can be used to determine whether the supercooling of the condenser side is sufficient in the cooling operation mode or whether the superheat of the evaporator side is sufficient in the heating operation mode. Adjusting the current speed of the fan according to the current valve opening of the expansion valve can prevent the system load from being too large under some special operating conditions. Thus, in the cooling operation mode, by controlling the current speed of the fan, the expansion valve can be assisted to quickly reach the target exhaust temperature.

[0220] Based on the technical solutions of the above embodiments, in some optional embodiments, taking the controller applied to an air conditioner as an example, the air conditioner control process in a refrigeration scenario is described.

[0221] See Figure 13 The air conditioner control method shown includes:

[0222] S1310, in response to the refrigeration start signal, starts the compressor 111 to run to the initial operating frequency, obtains the current external ambient temperature, and starts the expansion valve to run to the initial opening degree that matches the current external ambient temperature.

[0223] S1320, control the compressor 111 to continue operating at a first incremental frequency, and the expansion valve to continue operating at a second incremental frequency that matches the current external ambient temperature. During operation, control the first pressure sensor to periodically detect the first pressure on the low-pressure side of the air conditioner, and the second temperature sensor to periodically detect the suction temperature at the suction port.

[0224] S1330 determines the operation adjustment strategy based on the pressure change of the first pressure at different detection times and the low-pressure temperature difference between the intake temperature and the saturation temperature corresponding to the first pressure.

[0225] Specifically, if the pressure change and low-pressure temperature difference meet the first condition, the operation adjustment strategy is to maintain the compressor 111's operating frequency from increasing during the first time period and then restore the original operating mode.

[0226] If the pressure change and low-pressure temperature difference meet the second condition, the operation adjustment strategy is determined to be to maintain the current operation mode when the first pressure is greater than the preset protection pressure, and to execute pressure protection when the first pressure is not greater than the preset protection pressure.

[0227] If the pressure change and low-pressure temperature difference meet the third condition, the operation adjustment strategy is determined to keep the operating frequency of compressor 111 from rising during the first time period, and to continuously increase the valve opening of the expansion valve according to the first preset frequency and the first adjustment range during the second time period.

[0228] The first condition is that the rate of change and acceleration of change of the first pressure are both less than 0 for a preset continuous period of time, and the low-pressure temperature difference is less than the first temperature difference threshold; the second condition is that the rate of change of the first pressure is less than 0, and the acceleration of change is not less than 0; the third condition is that the rate of change of the first pressure is not less than 0 for a preset continuous period of time, and the low-pressure temperature difference is not less than the second temperature difference threshold.

[0229] S1340, based on the operation adjustment strategy, performs operation control on the operating frequency of compressor 111 and / or the valve opening of expansion valve.

[0230] Based on the technical solutions of the above embodiments, in some optional embodiments, taking the controller applied to an air conditioner as an example, the air conditioner control process in the heating scenario is described.

[0231] See Figure 14 The air conditioner control method shown includes:

[0232] S1410, in response to the heating start signal, starts the compressor 111 to run to the initial operating frequency, obtains the current external ambient temperature, and starts the expansion valve to run to the initial opening degree that matches the current external ambient temperature.

[0233] S1420, control the compressor 111 to continue operating at a first incremental frequency, and the expansion valve to continue operating at a second incremental frequency that matches the current external ambient temperature. During operation, control the first pressure sensor to periodically detect the first pressure on the low-pressure side of the air conditioner, and the second temperature sensor to periodically detect the suction temperature at the suction port.

[0234] S1430 determines the operation adjustment strategy based on the pressure change of the first pressure at different detection times and the low-pressure temperature difference between the intake temperature and the saturation temperature corresponding to the first pressure.

[0235] Specifically, if the pressure change and low-pressure temperature difference meet the first condition, the operation adjustment strategy is to maintain the compressor 111's operating frequency from increasing during the first time period and then restore the original operating mode.

[0236] If the pressure change and low-pressure temperature difference meet the second condition, the operation adjustment strategy is determined to be to maintain the current operation mode when the first pressure is greater than the preset protection pressure, and to execute pressure protection when the first pressure is not greater than the preset protection pressure.

[0237] If the pressure change and low-pressure temperature difference meet the third condition, the operation adjustment strategy is determined to keep the operating frequency of compressor 111 from rising during the first time period, and to continuously increase the valve opening of the expansion valve according to the first preset frequency and the first adjustment range during the second time period.

[0238] The first condition is that the rate of change and acceleration of change of the first pressure are both less than 0 for a preset continuous period of time, and the low-pressure temperature difference is less than the first temperature difference threshold; the second condition is that the rate of change of the first pressure is less than 0, and the acceleration of change is not less than 0; the third condition is that the rate of change of the first pressure is not less than 0 for a preset continuous period of time, and the low-pressure temperature difference is not less than the second temperature difference threshold.

[0239] S1440, based on the operation adjustment strategy, performs operation control on the operating frequency of compressor 111 and / or the valve opening of expansion valve.

[0240] Based on the same inventive concept, this application also provides an air conditioner control device for implementing the air conditioner control method described above. The solution provided by this device is similar to the solution described in the above method; therefore, the specific limitations in one or more air conditioner control device embodiments provided below can be found in the limitations of the air conditioner control method described above, and will not be repeated here.

[0241] In one exemplary embodiment, such as Figure 15 As shown, an air conditioner control device is provided, including: a start module 1510, a first control module 1520, a first determination module 1530, and a second control module 1540. Wherein,

[0242] The start module 1510 is used to respond to the start signal, start the air conditioner compressor to run to the initial operating frequency, obtain the current external ambient temperature, and start the air conditioner expansion valve to run to the initial opening degree that matches the current external ambient temperature;

[0243] The first control module 1520 is used to control the compressor to continue operating at a first incremental frequency and the expansion valve to continue operating at a second incremental frequency that matches the current external ambient temperature. During operation, the first pressure sensor of the air conditioner periodically detects the first pressure on the low-pressure side of the air conditioner, and the second temperature sensor of the air conditioner periodically detects the suction temperature at the air intake of the air conditioner.

[0244] The first determining module 1530 is used to determine the operation adjustment strategy based on the pressure change of the first pressure at different detection times and the low-pressure temperature difference between the intake temperature and the saturation temperature corresponding to the first pressure.

[0245] The second control module 1540 is used to control the operating frequency of the compressor and / or the valve opening of the expansion valve according to the operation adjustment strategy.

[0246] In some embodiments, the first determining module 1530 is specifically configured to: determine an operation adjustment strategy of restoring the original operation mode after preventing the compressor's operating frequency from increasing during a first time period when the pressure change and low-pressure temperature difference conditions meet a first condition; determine an operation adjustment strategy of maintaining the current operation mode when the first pressure is greater than the preset protection pressure and performing pressure protection when the first pressure is not greater than the preset protection pressure when the pressure change and low-pressure temperature difference conditions meet a second condition; determine an operation adjustment strategy of maintaining the compressor's operating frequency from increasing during the first time period and continuously increasing the valve opening of the expansion valve according to the first preset frequency and the first adjustment range during a second time period when the pressure change and low-pressure temperature difference conditions meet a third condition; wherein the first condition is that the rate of change and acceleration of change of the first pressure are both less than 0 for a preset continuous duration, and the low-pressure temperature difference value is less than the first temperature difference threshold; the second condition is that the rate of change of the first pressure is less than 0, and the acceleration of change is not less than 0; the third condition is that the rate of change of the first pressure is not less than 0 for a preset continuous duration, and the low-pressure temperature difference value is not less than the second temperature difference threshold.

[0247] In some embodiments, the device further includes: a second determining module, configured to determine a valve step adjustment strategy based on the exhaust temperature difference between the current exhaust temperature and the target exhaust temperature when the frequency difference between the current operating frequency of the compressor and the target operating frequency corresponding to the current external ambient temperature is less than a preset frequency threshold; and a third control module, configured to control the valve opening of the expansion valve according to the valve step adjustment strategy.

[0248] In some embodiments, the second determining module is specifically configured to: determine a valve step adjustment strategy of reducing the current valve step of the expansion valve when the exhaust temperature difference between the current exhaust temperature and the target exhaust temperature narrows to within a first temperature difference range; determine a valve step adjustment strategy of maintaining the current valve step of the expansion valve when the exhaust temperature difference between the current exhaust temperature and the target exhaust temperature narrows from the first temperature difference range to the second temperature difference range, or increases from the second temperature difference range to the third temperature difference range; and re-acquire the target exhaust temperature and the current exhaust temperature corresponding to the current external ambient temperature to redetermine the valve step adjustment strategy when the exhaust temperature difference between the current exhaust temperature and the target exhaust temperature exceeds the third temperature difference range.

[0249] In some embodiments, the device further includes: a fourth control module, configured to increase the operating frequency of the compressor when the valve opening of the expansion valve is adjusted to the lower limit of the valve opening; and a fifth control module, configured to decrease the operating frequency of the compressor when the valve opening of the expansion valve is adjusted to the upper limit of the valve opening.

[0250] In some embodiments, the fourth control module is specifically used to increase the operating frequency of the compressor according to the first preset frequency amplitude; when the exhaust temperature difference between the current exhaust temperature and the target exhaust temperature exceeds the fourth temperature difference threshold, the operating frequency of the compressor is increased again according to the first preset frequency amplitude, and the operating frequency of the compressor is kept from increasing further.

[0251] In some embodiments, the fifth control module is specifically used to reduce the operating frequency of the compressor according to the second preset frequency amplitude; when the exhaust temperature difference between the current exhaust temperature and the target exhaust temperature exceeds the fourth temperature difference threshold, the operating frequency of the compressor is reduced again according to the second preset frequency amplitude, and the operating frequency of the compressor is kept unchanged.

[0252] In some embodiments, the device further includes: a sixth control module, configured to control the four-way valve to switch to heating operation when the difference between the current external ambient temperature and the current inlet water temperature is greater than the water loop temperature difference threshold and the start signal is a cooling start signal, and to control the four-way valve to switch to cooling operation after a first heating operation duration; and a seventh control module, configured to control the air conditioner to switch to heating operation after a second cooling operation duration when the difference between the current inlet water temperature and the current external ambient temperature is greater than the water loop temperature difference threshold and the start signal is a heating start signal.

[0253] In some embodiments, the device further includes: an eighth control module, configured to control the expansion valve to maintain its current valve step and the compressor to maintain its current operating frequency when the current exhaust temperature is close to a first exhaust temperature threshold, the air conditioner is in cooling operation, the currently set demand water temperature exceeds a first temperature difference between the current inlet water temperature and the current exhaust temperature is less than a first upper temperature threshold and no longer rises; and a ninth control module, configured to control the expansion valve to adjust its current valve step according to the current exhaust temperature and the preset temperature range when the current exhaust temperature is close to the first exhaust temperature threshold, the air conditioner is in heating operation, the currently set demand water temperature is lower than a first temperature difference between the current inlet water temperature and the current exhaust temperature rises to exceed a preset temperature range, until the demand water temperature is lower than a second temperature difference between the current inlet water temperature and the current exhaust temperature is less than the lower limit of the preset temperature range.

[0254] In some embodiments, the ninth control module is specifically used to: control the current valve step of the expansion valve to decrease when the current exhaust temperature is lower than the lower limit of the preset temperature range; and control the current valve step of the expansion valve to increase when the current exhaust temperature is higher than the upper limit of the preset temperature range.

[0255] In some embodiments, the device further includes: a tenth control module, configured to control the reduction of the compressor's operating frequency and prohibit the reduction of the expansion valve's valve opening when the current exhaust pressure is greater than the first pressure difference of the system shutdown pressure; and an eleventh control module, configured to further reduce the compressor's operating frequency when the current exhaust pressure is greater than the second pressure difference of the system shutdown pressure for a third duration.

[0256] In some embodiments, the device further includes: a third determining module, configured to determine the current exhaust temperature difference between the target exhaust temperature corresponding to the current external ambient temperature and the current exhaust temperature; a query module, configured to, when the current exhaust temperature is less than the target exhaust temperature, query a speed adjustment method that matches the start signal, the current valve opening of the expansion valve, and the current exhaust temperature difference based on a speed adjustment query table; and a twelfth control module, configured to control the current speed of the fan according to the speed adjustment method; wherein the initial speed of the fan is obtained by querying an initial speed table based on the start signal, the current external ambient temperature, and the currently set required water temperature.

[0257] Each module in the aforementioned air conditioner control device can be implemented entirely or partially through software, hardware, or a combination thereof. These modules can be embedded in or independent of the processor in a computer device, or stored in the memory of a computer device as software, so that the processor can call and execute the operations corresponding to each module.

[0258] In one exemplary embodiment, a computer device is provided, which may be a terminal, and its internal structure diagram may be as follows: Figure 16As shown, the computer device includes a processor, memory, input / output interface, communication interface, display unit, and input device. The processor, memory, and input / output interface are connected via a system bus, and the communication interface, display unit, and input device are also connected to the system bus via the input / output interface. The processor provides computing and control capabilities. The memory includes non-volatile storage media and internal memory. The non-volatile storage media stores the operating system and computer programs. The internal memory provides the environment for the operation of the operating system and computer programs stored in the non-volatile storage media. The input / output interface is used for exchanging information between the processor and external devices. The communication interface is used for wired or wireless communication with external terminals; wireless communication can be achieved through Wi-Fi, mobile cellular networks, Near Field Communication (NFC), or other technologies. When the computer program is executed by the processor, it implements an air conditioner control method. The display unit is used to form a visually visible image and can be a display screen, projection device, or virtual reality imaging device. The display screen can be an LCD screen or an e-ink screen. The input device of the computer device can be a touch layer covering the display screen, or buttons, trackballs, or touchpads set on the casing of the computer device, or external keyboards, touchpads, or mice, etc.

[0259] Those skilled in the art will understand that Figure 16 The structure shown is merely a block diagram of a portion of the structure related to the present application and does not constitute a limitation on the computer device to which the present application is applied. Specific computer devices may include more or fewer components than those shown in the figure, or combine certain components, or have different component arrangements.

[0260] In one exemplary embodiment, a computer device is provided, including a memory and a processor. The memory stores a computer program, and the processor executes the computer program to implement the steps in the above-described method embodiments. In one embodiment, a computer-readable storage medium is provided, on which a computer program is stored, and the computer program, when executed by a processor, implements the steps in the above-described method embodiments.

[0261] In one embodiment, a computer program product is provided, including a computer program that, when executed by a processor, implements the steps in the above method embodiments.

[0262] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, stored data, displayed data, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties, and the collection, use and processing of the relevant data must comply with relevant regulations.

[0263] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium. When executed, the computer program can include the processes of the embodiments of the above methods. Any references to memory, databases, or other media used in the embodiments provided in this application can include at least one of non-volatile memory and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can take many forms, such as Static Random Access Memory (SRAM) or Dynamic Random Access Memory (DRAM). The databases involved in the embodiments provided in this application may include at least one type of relational database and non-relational database. Non-relational databases may include, but are not limited to, blockchain-based distributed databases. The processors involved in the embodiments provided in this application may be general-purpose processors, central processing units, graphics processing units, digital signal processors, programmable logic devices, quantum computing-based data processing logic devices, artificial intelligence (AI) processors, etc., and are not limited to these.

[0264] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this application.

[0265] The above embodiments are merely illustrative of several implementation methods of this application, and their descriptions are relatively specific and detailed. However, they should not be construed as limiting the scope of this application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.

Claims

1. An air conditioner, characterized in that, include: Refrigerant circulation loop, first temperature sensor, first pressure sensor, second temperature sensor and controller; The refrigerant circulation loop includes a compressor, a first heat exchanger, an expansion valve, a second heat exchanger, and a four-way valve connected in sequence. The first heat exchanger is configured to exchange heat with outdoor air; The compressor is configured to compress refrigerant in a low-pressure state to a high-pressure state and drive the refrigerant to circulate within the refrigerant circulation loop. The expansion valve is configured to regulate the flow rate of the refrigerant in the refrigerant circulation loop; The second heat exchanger, connected to the water circulation loop, is configured to achieve heat exchange between the water in the water circulation loop and the refrigerant. The four-way valve is configured to switch the operating mode of the air conditioner; the operating mode includes a cooling mode and a heating mode. The first temperature sensor is used to detect the external ambient temperature; The first pressure sensor is used to detect the first pressure on the low-pressure side of the air conditioner; The second temperature sensor is used to detect the intake temperature of the compressor intake port; The controller is configured as follows: In response to the start signal, the compressor is started to run at the initial operating frequency, the current external ambient temperature is obtained, and the expansion valve is started to run to an initial opening degree that matches the current external ambient temperature; The compressor is controlled to operate at a first incremental frequency, and the expansion valve continues to operate at a second incremental frequency that matches the current external ambient temperature. During operation, the first pressure sensor is controlled to periodically detect the first pressure on the low-pressure side of the air conditioner, and the second temperature sensor is controlled to periodically detect the suction temperature at the suction port. Based on the pressure change of the first pressure at different detection times, and the low-pressure temperature difference between the intake temperature and the saturation temperature corresponding to the first pressure, the operation adjustment strategy is determined. According to the aforementioned operation adjustment strategy, the operating frequency of the compressor and / or the valve opening of the expansion valve are controlled.

2. The air conditioner according to claim 1, characterized in that, When the controller determines the operation adjustment strategy based on the pressure change of the first pressure at different detection times and the low-pressure temperature difference between the intake temperature and the saturation temperature corresponding to the first pressure, it is configured as follows: If the pressure change and the low-pressure temperature difference meet the first condition, the operation adjustment strategy is determined to be to restore the original operation mode after keeping the compressor's operating frequency prohibited from increasing during the first time period. If the pressure change and the low-pressure temperature difference meet the second condition, the operation adjustment strategy is determined to be to maintain the current operation mode when the first pressure is greater than the preset protection pressure, and to perform pressure protection when the first pressure is not greater than the preset protection pressure. If the pressure change and the low-pressure temperature difference meet the third condition, the operation adjustment strategy is determined to keep the operating frequency of the compressor from increasing during the first time period, and to continuously increase the valve opening of the expansion valve according to the first preset frequency and the first adjustment range during the second time period. The first condition is that for a preset continuous period of time, both the rate of change and the acceleration of change of the first pressure are less than 0, and the low-pressure temperature difference is less than a first temperature difference threshold; the second condition is that the rate of change of the first pressure is less than 0, and the acceleration of change is not less than 0; the third condition is that for a preset continuous period of time, the rate of change of the first pressure is not less than 0, and the low-pressure temperature difference is not less than a second temperature difference threshold.

3. The air conditioner according to claim 1 or 2, characterized in that, The air conditioner also includes a third temperature sensor configured to detect the exhaust temperature at the exhaust port; the controller is further configured to: If the frequency difference between the current operating frequency of the compressor and the target operating frequency corresponding to the current external ambient temperature is less than a preset frequency threshold, a valve step adjustment strategy is determined based on the difference in exhaust temperature between the current exhaust temperature and the target exhaust temperature. The valve opening of the expansion valve is controlled according to the valve step adjustment strategy.

4. The air conditioner according to claim 3, characterized in that, When the controller executes the valve step adjustment strategy based on the difference between the current exhaust temperature and the target exhaust temperature, it is configured as follows: When the exhaust temperature difference between the current exhaust temperature and the target exhaust temperature is reduced to within the first temperature difference range, the valve step adjustment strategy is determined to be to reduce the current valve step of the expansion valve. If the exhaust temperature difference between the current exhaust temperature and the target exhaust temperature decreases from the first temperature difference range to the second temperature difference range, or increases from the second temperature difference range to the third temperature difference range, the valve step adjustment strategy is determined to maintain the current valve step of the expansion valve. If the exhaust temperature difference between the current exhaust temperature and the target exhaust temperature exceeds the third temperature difference range, the target exhaust temperature and the current exhaust temperature corresponding to the current external ambient temperature are reacquired to redetermine the valve step adjustment strategy.

5. The air conditioner according to claim 1 or 2, characterized in that, The controller is also configured to: When the valve opening of the expansion valve is adjusted to the lower limit of the valve opening, the operating frequency of the compressor is controlled to be increased. When the valve opening of the expansion valve is adjusted to the upper limit of the valve opening, the operating frequency of the compressor is controlled to be reduced.

6. The air conditioner according to claim 5, characterized in that, When the controller executes the control to increase the operating frequency of the compressor, it is configured to: The operating frequency of the compressor is increased according to the first preset frequency amplitude; If the temperature difference between the current exhaust temperature and the target exhaust temperature exceeds the fourth temperature difference threshold, the operating frequency of the compressor is increased again according to the first preset frequency amplitude, and the operating frequency of the compressor is kept from increasing further.

7. The air conditioner according to claim 5, characterized in that, When the controller performs the action of reducing the operating frequency of the compressor, it is configured to: The operating frequency of the compressor is reduced according to the second preset frequency amplitude; If the temperature difference between the current exhaust temperature and the target exhaust temperature exceeds the fourth temperature difference threshold, the operating frequency of the compressor is reduced again according to the second preset frequency amplitude, while keeping the operating frequency of the compressor unchanged.

8. The air conditioner according to claim 1 or 2, characterized in that, The air conditioner is also equipped with a fourth temperature sensor, configured to detect the inlet water temperature of the second heat exchanger; the controller is further configured to: When the difference between the current external ambient temperature and the current inlet water temperature is greater than the circulating water temperature difference threshold, and the start signal is a cooling start signal, the four-way valve is controlled to switch to heating operation, and after the first heating operation duration, the four-way valve is controlled to switch to cooling operation. If the difference between the current inlet water temperature and the current external ambient temperature is greater than the water ring temperature difference threshold, and the start signal is a heating start signal, the air conditioner is controlled to run in cooling mode for a second duration before the four-way valve is switched to heating mode.

9. The air conditioner according to claim 1 or 2, characterized in that, The air conditioner is also equipped with: The third temperature sensor is configured to detect the exhaust temperature at the exhaust port; A fourth temperature sensor is configured to detect the inlet water temperature at the heat exchanger inlet. The controller is also configured to: If the current exhaust temperature is close to the first exhaust temperature threshold, the air conditioner is in cooling operation, the currently set required water temperature exceeds the first temperature difference between the current inlet water temperature and the current exhaust temperature is less than the first upper temperature threshold and no longer rises, then the expansion valve is controlled to maintain the current valve step, and the compressor is controlled to maintain the current operating frequency. If the current exhaust temperature is close to the first exhaust temperature threshold, the air conditioner is in heating mode, the currently set required water temperature is lower than the first temperature difference between the current inlet water temperature and the current exhaust temperature rises to exceed the preset temperature range, then the current valve step of the expansion valve is controlled and adjusted according to the current exhaust temperature and the preset temperature range until the required water temperature is lower than the second temperature difference between the current inlet water temperature and the current exhaust temperature is less than the lower limit of the preset temperature range.

10. The air conditioner according to claim 9, characterized in that, When the controller performs the action of adjusting the current valve step of the expansion valve based on the current exhaust temperature and the preset temperature range, it is configured to: If the current exhaust temperature is lower than the lower limit of the preset temperature range, the current valve step of the expansion valve is reduced. If the current exhaust temperature is greater than the upper limit of the preset temperature range, the current valve step of the expansion valve is increased.

11. The air conditioner according to claim 1 or 2, characterized in that, The air conditioner also includes a second pressure sensor configured to detect the exhaust pressure of the exhaust pipe in the air conditioner; the controller is further configured to: When the current exhaust pressure is greater than the first pressure difference of the system shutdown pressure, control the compressor to reduce its operating frequency and prohibit the reduction of the expansion valve opening. If the current exhaust pressure is greater than the system shutdown pressure for a second pressure difference for a third duration, the operating frequency of the compressor will be reduced again.

12. The air conditioner according to claim 1 or 2, characterized in that, The air conditioner is also equipped with: The third temperature sensor is configured to detect the exhaust temperature at the exhaust port; An outdoor fan is configured to drive outdoor air through the first heat exchanger by rotation, so that the refrigerant exchanges heat with the outdoor air; The controller is also configured to: Determine the current exhaust temperature difference between the target exhaust temperature corresponding to the current external ambient temperature and the current exhaust temperature; If the current exhaust temperature is lower than the target exhaust temperature, based on the speed adjustment lookup table, look up the speed adjustment method that matches the start signal, the current valve opening of the expansion valve, and the current exhaust temperature difference; According to the speed adjustment method, the current speed of the fan is controlled; wherein, the initial speed of the fan is obtained by querying the initial speed table based on the start signal, the current external ambient temperature and the currently set required water temperature.

13. An air conditioner control method, characterized in that, include: In response to the start signal, the compressor of the air conditioner is started to run to the initial operating frequency, the current external ambient temperature is obtained, and the expansion valve of the air conditioner is started to run to the initial opening degree that matches the current external ambient temperature; The compressor is controlled to operate at a first incremental frequency, and the expansion valve continues to operate at a second incremental frequency that matches the current external ambient temperature. During operation, the first pressure sensor of the air conditioner is controlled to periodically detect the first pressure on the low-pressure side of the air conditioner, and the second temperature sensor of the air conditioner is controlled to periodically detect the suction temperature at the air intake of the air conditioner. Based on the pressure change of the first pressure at different detection times, and the low-pressure temperature difference between the intake temperature and the saturation temperature corresponding to the first pressure, the operation adjustment strategy is determined. According to the aforementioned operation adjustment strategy, the operating frequency of the compressor and / or the valve opening of the expansion valve are controlled.

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