Control method of air conditioner, storage medium, program product, and air conditioning system

Abstract

The application provides a control method of an air conditioner, a storage medium, a program product and an air conditioning system. The method comprises the following steps: acquiring a pre-throttling pressure, an outlet pressure of an indoor heat exchanger and an outlet temperature of the indoor heat exchanger, wherein the pre-throttling pressure represents the pressure at the inlet of a throttling element; determining an exhaust temperature of a compressor according to the pre-throttling pressure, the outlet pressure of the indoor heat exchanger and the outlet temperature of the indoor heat exchanger; determining an outlet superheat degree of the indoor heat exchanger according to the outlet pressure of the indoor heat exchanger and the outlet temperature of the indoor heat exchanger; and controlling the opening degree of the throttling element according to the exhaust temperature of the compressor and the outlet superheat degree of the indoor heat exchanger. The application solves the problem of low reliability of the air conditioner system in the prior art.

Description

Technical Field

[0001] This application relates to the field of air conditioner technology, and more specifically, to an air conditioner control method, a computer-readable storage medium, a computer program product, and an air conditioning system. Background Technology

[0002] Residential split air conditioning or heat pump systems typically use a 24V thermostat signal to control both the indoor and outdoor units. The indoor and outdoor units generally only communicate via low-voltage control signals for simple start / stop or mode switching. There is no data communication between the indoor and outdoor units to transmit operating parameters such as compressor discharge temperature, compressor frequency, outdoor unit pressure, and outdoor fan status. In residential units without communication, the indoor unit cannot directly obtain the outdoor unit's discharge temperature, resulting in lower system reliability. Summary of the Invention

[0003] The main objective of this application is to provide a control method for an air conditioner, a computer-readable storage medium, a computer program product, and an air conditioning system, so as to at least solve the problem of low reliability in the operation of air conditioning systems in the prior art.

[0004] To achieve the above objectives, according to one aspect of this application, a control method for an air conditioner is provided. The air conditioner includes an indoor unit and an outdoor unit. The indoor unit includes a throttling element and an indoor heat exchanger. The outdoor unit includes a compressor. The suction port of the compressor is connected to the outlet of the indoor heat exchanger, the discharge port of the compressor is connected to the inlet of the throttling element, and the outlet of the throttling element is connected to the inlet of the indoor heat exchanger. The method includes: acquiring a pressure before throttling, an outlet pressure of the indoor heat exchanger, and an outlet temperature of the indoor heat exchanger, wherein the pressure before throttling represents the pressure at the inlet of the throttling element; determining the discharge temperature of the compressor based on the pressure before throttling, the outlet pressure of the indoor heat exchanger, and the outlet temperature of the indoor heat exchanger; determining the outlet superheat of the indoor heat exchanger based on the outlet pressure of the indoor heat exchanger and the outlet temperature of the indoor heat exchanger; and controlling the opening degree of the throttling element based on the discharge temperature of the compressor and the outlet superheat of the indoor heat exchanger.

[0005] Optionally, the air conditioner further includes an intake pipe, through which the intake port of the compressor is connected to the outlet of the indoor heat exchanger. The discharge temperature of the compressor is determined based on the pre-throttling pressure, the outlet pressure of the indoor heat exchanger, and the outlet temperature of the indoor heat exchanger. This includes: determining the discharge pressure of the compressor based on the pre-throttling pressure and a preset high-pressure side pressure compensation, whereby the high-pressure side pressure compensation compensates for the pressure loss between the compressor's discharge port and the inlet of the throttling element; determining the intake pressure of the compressor based on the outlet pressure of the indoor heat exchanger and a preset low-pressure side pressure compensation, whereby the low-pressure side pressure compensation compensates for the pressure loss between the outlet of the indoor heat exchanger and the compressor's intake port; determining the intake temperature of the compressor based on the outlet temperature of the indoor heat exchanger and a preset intake pipe temperature rise compensation, whereby the intake pipe temperature rise compensation compensates for the temperature rise caused by the refrigerant absorbing heat in the intake pipe; and determining the discharge temperature of the compressor based on the discharge pressure, the intake pressure, and the intake temperature of the compressor.

[0006] Optionally, determining the discharge temperature of the compressor based on the compressor's discharge pressure, suction pressure, and suction temperature includes: determining the compressor's suction enthalpy and suction entropy based on the compressor's suction pressure and suction temperature; determining the compressor's isentropic compression endpoint enthalpy based on the compressor's discharge pressure and suction entropy; determining the compressor's isentropic efficiency based on the compressor's discharge pressure and suction pressure; determining the compressor's actual discharge enthalpy based on the compressor's suction enthalpy, isentropic compression endpoint enthalpy, and isentropic efficiency; and determining the compressor's discharge temperature based on the compressor's actual discharge enthalpy and discharge pressure.

[0007] Optionally, determining the actual discharge enthalpy of the compressor based on the compressor's intake enthalpy, the compressor's isentropic compression endpoint enthalpy, and the compressor's isentropic efficiency includes: calculating the difference between the compressor's isentropic compression endpoint enthalpy and the compressor's intake enthalpy to obtain a first difference; calculating the ratio of the first difference to the compressor's isentropic efficiency to obtain a first ratio; and adding the compressor's intake enthalpy to the first ratio to obtain the compressor's actual discharge enthalpy.

[0008] Optionally, the air conditioner further includes a first pressure sensor, a second pressure sensor, and a temperature sensor. The first pressure sensor is disposed at the inlet of the throttling element, and the second pressure sensor and the temperature sensor are both disposed at the outlet of the indoor heat exchanger. Acquiring the pre-throttling pressure, the outlet pressure of the indoor heat exchanger, and the outlet temperature of the indoor heat exchanger includes: acquiring the pre-throttling pressure using the first pressure sensor; acquiring the outlet pressure of the indoor heat exchanger using the second pressure sensor; acquiring the outlet temperature of the indoor heat exchanger using the temperature sensor; and determining the compressor's discharge temperature based on the pre-throttling pressure, the outlet pressure of the indoor heat exchanger, and the outlet temperature of the indoor heat exchanger, including: determining the compressor's initial discharge temperature based on the outlet pressure of the indoor heat exchanger, the pre-throttling pressure, and the outlet temperature of the indoor heat exchanger; and determining the compressor's discharge temperature based on the compressor's initial discharge temperature and a preset error temperature compensation, wherein the error temperature compensation is at least used to compensate for the detection errors of the first pressure sensor, the second pressure sensor, and the temperature sensor.

[0009] Optionally, determining the outlet superheat of the indoor heat exchanger based on its outlet pressure and outlet temperature includes: using the refrigerant property table of the air conditioner to determine the saturation temperature corresponding to the outlet pressure of the indoor heat exchanger; and calculating the difference between the outlet temperature of the indoor heat exchanger and the saturation temperature corresponding to its outlet pressure to obtain the outlet superheat of the indoor heat exchanger.

[0010] Optionally, controlling the opening of the throttling element based on the compressor's discharge temperature and the outlet superheat of the indoor heat exchanger includes: determining whether the outlet superheat of the indoor heat exchanger is less than or equal to a preset outlet superheat threshold; if the outlet superheat of the indoor heat exchanger is less than or equal to the outlet superheat threshold, determining that the outlet superheat of the indoor heat exchanger is insufficient; if the outlet superheat of the indoor heat exchanger is insufficient, determining whether the compressor's discharge temperature is less than a preset first temperature threshold; and if the compressor's discharge temperature is not less than the first temperature threshold, controlling the opening of the throttling element to remain unchanged or increase.

[0011] Optionally, controlling the opening of the throttling element to remain constant or increase includes: when the compressor's discharge temperature is not less than the first temperature threshold and less than a preset second temperature threshold, controlling the opening of the throttling element to remain constant, wherein the first temperature threshold is less than the second temperature threshold; when the compressor's discharge temperature is not less than the second temperature threshold and less than a preset third temperature threshold, controlling the opening of the throttling element to increase at a preset rate based on the difference between the compressor's discharge temperature and the second temperature threshold, wherein the second temperature threshold is less than the third temperature threshold; when the compressor's discharge temperature is not less than the third temperature threshold and remains so for a first preset duration, controlling the opening of the throttling element to increase by a preset opening, and outputting a fault signal or controlling the compressor to shut down.

[0012] Optionally, controlling the opening degree of the throttling element based on the compressor's discharge temperature and the outlet superheat of the indoor heat exchanger further includes: if the compressor's discharge temperature is less than the first temperature threshold, determining whether the compressor's discharge temperature at the current moment is greater than the compressor's discharge temperature at the previous moment, the previous moment being before the current moment; if the compressor's discharge temperature at the current moment is greater than the compressor's discharge temperature at the previous moment, controlling the opening degree of the throttling element to decrease; if the compressor's discharge temperature at the current moment is less than the compressor's discharge temperature at the previous moment, determining whether the compressor's discharge temperature at the current moment is less than a fourth temperature threshold, the fourth temperature threshold being less than the first temperature threshold; if the compressor's discharge temperature at the current moment is less than the fourth temperature threshold and remains so for a second preset duration, controlling the opening degree of the throttling element to decrease; and if the compressor's discharge temperature at the current moment is not less than the fourth temperature threshold, the air conditioner's controller maintaining the control command to the throttling element from the previous moment.

[0013] Optionally, obtaining the pre-throttling pressure, the outlet pressure of the indoor heat exchanger, and the outlet temperature of the indoor heat exchanger includes: determining whether the compressor's operating time is greater than a preset operating time when the throttling element is open; and obtaining the pre-throttling pressure, the outlet pressure of the indoor heat exchanger, and the outlet temperature of the indoor heat exchanger when the compressor's operating time is greater than the preset operating time.

[0014] Optionally, after acquiring the pre-throttling pressure, the outlet pressure of the indoor heat exchanger, and the outlet temperature of the indoor heat exchanger, and before determining the compressor's discharge temperature based on the pre-throttling pressure, the outlet pressure of the indoor heat exchanger, and the outlet temperature of the indoor heat exchanger, the method further includes: determining whether a sensor is in an abnormal state, the sensor including a first pressure sensor, a second pressure sensor, and the temperature sensor, the abnormal state including at least one of the following: the pressure of the first pressure sensor is less than a preset minimum pre-throttling pressure threshold, the pressure of the first pressure sensor is greater than a preset maximum pre-throttling pressure threshold, and the pressure of the second pressure sensor is less than a preset minimum outlet pressure. The following conditions are considered: a pressure threshold, the pressure of the second pressure sensor being greater than a preset maximum outlet pressure threshold, the temperature of the temperature sensor being less than a preset minimum outlet temperature threshold, and the temperature of the temperature sensor being greater than a preset maximum outlet temperature threshold; when the sensor is in the abnormal state, controlling the opening degree of the throttling element to be no less than a preset minimum opening degree threshold; determining the compressor's discharge temperature based on the pre-throttling pressure, the outlet pressure of the indoor heat exchanger, and the outlet temperature of the indoor heat exchanger, including: when the sensor is not in the abnormal state, determining the compressor's discharge temperature based on the pre-throttling pressure, the outlet pressure of the indoor heat exchanger, and the outlet temperature of the indoor heat exchanger.

[0015] According to another aspect of this application, a computer-readable storage medium is provided, the computer-readable storage medium including a stored program, wherein, when the program is executed, it controls the device where the computer-readable storage medium is located to perform any of the control methods of the air conditioner described above.

[0016] According to another aspect of this application, a computer program product is provided, including computer instructions that, when executed by a processor, implement any of the control methods for the air conditioner described above.

[0017] According to another aspect of this application, an air conditioning system is provided, comprising: an air conditioner including an indoor unit and an outdoor unit, the indoor unit including a throttling element and an indoor heat exchanger, the outdoor unit including a compressor, the compressor's intake port being connected to the outlet of the indoor heat exchanger, the compressor's exhaust port being connected to the inlet of the throttling element, and the throttling element's outlet being connected to the inlet of the indoor heat exchanger; and a controller communicatively connected to the air conditioner, the controller including: one or more processors, a memory, and one or more programs, wherein the one or more programs are stored in the memory and configured to be executed by the one or more processors, the one or more programs including a control method for performing any of the air conditioner described above.

[0018] By applying the technical solution of this application, the pressure before throttling, the outlet pressure and the outlet temperature of the indoor heat exchanger are first obtained. Then, the discharge temperature of the compressor is determined based on the pressure before throttling, the outlet pressure and the outlet temperature of the indoor heat exchanger. Next, the outlet superheat of the indoor heat exchanger is determined based on the outlet pressure and the outlet temperature of the indoor heat exchanger. Finally, the opening degree of the throttling element is controlled based on the discharge temperature of the compressor and the outlet superheat of the indoor heat exchanger. To address the issue of low reliability in existing air conditioning systems, this application indirectly derives the compressor's discharge temperature by acquiring the pre-throttling pressure (characterizing the inlet pressure of the throttling element), the outlet pressure of the indoor heat exchanger, and the outlet temperature. This allows the indoor unit to monitor the compressor's discharge status without relying on communication between the indoor and outdoor units or sensors in the outdoor unit. Simultaneously, by combining the outlet pressure and temperature of the indoor heat exchanger to determine the outlet superheat, the opening of the throttling element is controlled collaboratively based on the compressor's discharge temperature and the indoor heat exchanger's superheat. This control logic, based on the dual parameters of compressor discharge temperature and indoor heat exchanger superheat, prevents compressor refrigerant return (determined by superheat) while avoiding blindly closing the throttling element due to excessively high discharge temperature. This optimizes refrigerant flow while ensuring the compressor discharge temperature remains within a safe range, thereby improving the system's reliability and stability. Attached Figure Description

[0019] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments and descriptions of this application are used to explain this application and do not constitute an undue limitation of this application. In the drawings:

[0020] Figure 1 A hardware structure block diagram of a mobile terminal for performing a control method for an air conditioner according to an embodiment of this application is shown;

[0021] Figure 2 A schematic flowchart of a control method for an air conditioner according to an embodiment of this application is shown;

[0022] Figure 3 A structural block diagram of an air conditioner provided according to an embodiment of this application is shown;

[0023] Figure 4 A flowchart illustrating a specific method for determining compressor exhaust temperature according to an embodiment of this application is shown.

[0024] Figure 5 A schematic flowchart illustrating a specific control method for an electronic expansion valve according to an embodiment of this application is shown.

[0025] The above figures include the following reference numerals:

[0026] 102. Processor; 104. Memory; 106. Transmission device; 108. Input / output device; 11. Throttling element; 12. Indoor heat exchanger; 13. Compressor; 14. Outdoor heat exchanger; A. Outdoor side; B. Indoor side. Detailed Implementation

[0027] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0028] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of protection of the present application.

[0029] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate for the embodiments of this application described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0030] As described in the background section, the reliability of air conditioning systems in the prior art is relatively low. To solve the above problems, embodiments of this application provide an air conditioning control method, a computer-readable storage medium, a computer program product, and an air conditioning system.

[0031] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.

[0032] The methods and embodiments provided in this application can be executed on a mobile terminal, computer terminal, or similar computing device. Taking running on a mobile terminal as an example, Figure 1 This is a hardware structure block diagram of a mobile terminal for an air conditioner control method according to an embodiment of the present invention. Figure 1 As shown, a mobile terminal may include one or more ( Figure 1Only one is shown in the diagram. A processor 102 (which may include, but is not limited to, a microprocessor MCU or a programmable logic device FPGA, etc.) and a memory 104 for storing data are also shown. The mobile terminal may further include a transmission device 106 for communication functions and an input / output device 108. Those skilled in the art will understand that... Figure 1 The structure shown is for illustrative purposes only and does not limit the structure of the mobile terminal described above. For example, the mobile terminal may also include components that are more... Figure 1 The more or fewer components shown, or having the same Figure 1 The different configurations shown.

[0033] The memory 104 can be used to store computer programs, such as application software programs and modules, like the computer program corresponding to the air conditioner control method in this embodiment of the invention. The processor 102 executes various functional applications and data processing by running the computer program stored in the memory 104, thereby implementing the above-described method. The memory 104 may include high-speed random access memory and non-volatile memory, such as one or more magnetic storage devices, flash memory, or other non-volatile solid-state memory. In some instances, the memory 104 may further include memory remotely located relative to the processor 102, and these remote memories can be connected to the mobile terminal via a network. Examples of the aforementioned networks include, but are not limited to, the Internet, corporate intranets, local area networks, mobile communication networks, and combinations thereof. The transmission device 106 is used to receive or send data via a network. Specific examples of the aforementioned networks may include wireless networks provided by the mobile terminal's communication provider. In one example, the transmission device 106 includes a network interface controller (NIC), which can be connected to other network devices via a base station to communicate with the Internet. In one example, the transmission device 106 may be a radio frequency (RF) module, which is used to communicate with the Internet wirelessly.

[0034] This embodiment provides a control method for an air conditioner that runs on a mobile terminal, computer terminal, or similar computing device. It should be noted that the steps shown in the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions. Also, although a logical order is shown in the flowchart, in some cases, the steps shown or described may be executed in a different order than that shown here.

[0035] Figure 2 This is a flowchart of an air conditioner control method according to an embodiment of this application. Figure 3As shown, the air conditioner includes an indoor unit (not shown) and an outdoor unit (not shown). The indoor unit includes a throttling element 11 and an indoor heat exchanger 12. The outdoor unit includes a compressor 13. The suction port of the compressor 13 is connected to the outlet of the indoor heat exchanger 12, the discharge port of the compressor 13 is connected to the inlet of the throttling element 11, and the outlet of the throttling element 11 is connected to the inlet of the indoor heat exchanger 12. Figure 2 As shown, the method includes the following steps:

[0036] Step S201: Obtain the pressure before throttling, the outlet pressure of the indoor heat exchanger, and the outlet temperature of the indoor heat exchanger. The pressure before throttling represents the pressure at the inlet of the throttling element.

[0037] In practical applications, those skilled in the art can flexibly select appropriate throttling elements and indoor heat exchangers according to actual needs, and this application does not impose specific restrictions in this regard.

[0038] In one embodiment, the throttling element includes an electronic expansion valve, and the indoor heat exchanger includes an evaporator.

[0039] Step S202: Determine the discharge temperature of the compressor based on the pressure before throttling, the outlet pressure of the indoor heat exchanger, and the outlet temperature of the indoor heat exchanger.

[0040] Step S203: Determine the outlet superheat of the indoor heat exchanger based on the outlet pressure and outlet temperature of the indoor heat exchanger.

[0041] Step S204: Control the opening degree of the throttling element based on the exhaust temperature of the compressor and the outlet superheat of the indoor heat exchanger.

[0042] In this embodiment, the pressure before throttling, the outlet pressure and the outlet temperature of the indoor heat exchanger are first obtained. Then, the discharge temperature of the compressor is determined based on the pressure before throttling, the outlet pressure and the outlet temperature of the indoor heat exchanger. Next, the outlet superheat of the indoor heat exchanger is determined based on the outlet pressure and the outlet temperature of the indoor heat exchanger. Finally, the opening degree of the throttling element is controlled based on the discharge temperature of the compressor and the outlet superheat of the indoor heat exchanger. To address the issue of low reliability in existing air conditioning systems, this application indirectly derives the compressor's discharge temperature by acquiring the pre-throttling pressure (characterizing the inlet pressure of the throttling element), the outlet pressure of the indoor heat exchanger, and the outlet temperature. This allows the indoor unit to monitor the compressor's discharge status without relying on communication between the indoor and outdoor units or sensors in the outdoor unit. Simultaneously, by combining the outlet pressure and temperature of the indoor heat exchanger to determine the outlet superheat, the opening of the throttling element is controlled collaboratively based on the compressor's discharge temperature and the indoor heat exchanger's superheat. This control logic, based on the dual parameters of compressor discharge temperature and indoor heat exchanger superheat, prevents compressor refrigerant return (determined by superheat) while avoiding blindly closing the throttling element due to excessively high discharge temperature. This optimizes refrigerant flow while ensuring the compressor discharge temperature remains within a safe range, thereby improving the system's reliability and stability.

[0043] In one embodiment, such as Figure 3 As shown, the outdoor unit is located on the outdoor side A, and the indoor unit is located on the indoor side B. The outdoor unit also includes an outdoor heat exchanger 14, and the exhaust port of the compressor 13 is connected to the inlet of the throttling element 11 through the outdoor heat exchanger 14. In one embodiment, the outdoor heat exchanger includes a condenser.

[0044] It's important to note that for residential air conditioning systems with indoor electronic expansion valves, the indoor unit can typically control the valve opening based on evaporator outlet temperature, evaporation pressure, or superheat. For example, when the evaporator outlet superheat is insufficient, traditional control logic usually reduces the electronic expansion valve opening to decrease the refrigerant flow into the evaporator and prevent compressor liquid return. However, when the outdoor unit's exhaust temperature is high, further reducing the valve opening may further reduce refrigerant flow, increase compressor suction superheat and exhaust temperature, affecting compressor reliability. Therefore, in systems with indoor-outdoor unit communication, the outdoor unit can usually transmit the exhaust temperature to the indoor unit, or the system can centrally control the valve steps. However, in residential systems without communication, the indoor unit cannot directly obtain the outdoor unit's exhaust temperature, causing the indoor unit's valve step control to fail to link with the outdoor unit's exhaust temperature protection logic.

[0045] In one optional embodiment, the air conditioner further includes an intake pipe, through which the intake port of the compressor is connected to the outlet of the indoor heat exchanger. The discharge temperature of the compressor is determined based on the pre-throttling pressure, the outlet pressure of the indoor heat exchanger, and the outlet temperature of the indoor heat exchanger. This includes: determining the discharge pressure of the compressor based on the pre-throttling pressure and a preset high-pressure side pressure compensation, wherein the high-pressure side pressure compensation compensates for the pressure loss between the compressor's discharge port and the inlet of the throttling element; determining the intake pressure of the compressor based on the outlet pressure of the indoor heat exchanger and a preset low-pressure side pressure compensation, wherein the low-pressure side pressure compensation compensates for the pressure loss between the outlet of the indoor heat exchanger and the compressor's intake port; determining the intake temperature of the compressor based on the outlet temperature of the indoor heat exchanger and a preset intake pipe temperature rise compensation, wherein the intake pipe temperature rise compensation compensates for the temperature rise caused by the refrigerant absorbing heat in the intake pipe; and determining the discharge temperature of the compressor based on the compressor's discharge pressure, intake pressure, and intake temperature.

[0046] In the above embodiments, by introducing high-pressure side pressure compensation, low-pressure side pressure compensation, and suction pipe temperature rise compensation, the measurable pre-throttling pressure, indoor heat exchanger outlet pressure, and temperature on the indoor unit side are corrected to discharge pressure, suction pressure, and suction temperature that are closer to the actual operating conditions of the compressor. This reduces the measurement error caused by pressure loss along the pipeline and heat exchange in the suction pipeline, significantly improving the accuracy of estimating the compressor discharge temperature based on indoor unit side data. This makes the subsequent control of the throttling element based on the estimated discharge temperature more accurate, thereby effectively improving the system's protection reliability under high discharge temperature conditions.

[0047] In one embodiment, determining the compressor's discharge pressure based on the pre-throttling pressure and a preset high-pressure side pressure compensation includes: determining the sum of the pre-throttling pressure and the high-pressure side pressure compensation as the compressor's discharge pressure; determining the compressor's suction pressure based on the indoor heat exchanger's outlet pressure and a preset low-pressure side pressure compensation includes: determining the difference between the indoor heat exchanger's outlet pressure and the low-pressure side pressure compensation as the compressor's suction pressure; and determining the compressor's suction temperature based on the indoor heat exchanger's outlet temperature and a preset suction pipe temperature rise compensation includes: determining the sum of the indoor heat exchanger's outlet temperature and the suction pipe temperature rise compensation as the compressor's suction temperature.

[0048] In practical applications, those skilled in the art can set the above-mentioned high-pressure side pressure compensation, low-pressure side pressure compensation and intake tube temperature rise compensation based on experience values, or obtain them through multiple experiments. This application does not impose specific limitations on this.

[0049] In another alternative, determining the discharge temperature of the compressor based on its discharge pressure, suction pressure, and suction temperature includes: determining the suction enthalpy and suction entropy of the compressor based on its suction pressure and suction temperature; determining the isentropic compression endpoint enthalpy of the compressor based on its discharge pressure and suction entropy; determining the isentropic efficiency of the compressor based on its discharge pressure and suction pressure; determining the actual discharge enthalpy of the compressor based on its suction enthalpy, isentropic compression endpoint enthalpy, and isentropic efficiency; and determining the discharge temperature of the compressor based on its actual discharge enthalpy and discharge pressure.

[0050] In the above embodiments, by utilizing the specific enthalpy and specific entropy of the refrigerant in the compressor suction state, and combining the discharge pressure to calculate the specific enthalpy at the isentropic compression endpoint, and introducing the compressor isentropic efficiency determined based on the pressure ratio to correct the energy loss in the actual compression process, the actual discharge specific enthalpy of the compressor can be derived more accurately, and thus the discharge temperature of the compressor can be determined more accurately. This process introduces the compressor thermodynamic characteristics (isentropic efficiency) to correct the theoretical compression process, avoiding the estimation errors caused by relying solely on ideal gases or simple property assumptions, thereby significantly improving the accuracy and reliability of estimating the compressor discharge temperature through indoor unit side parameters in a non-communication environment.

[0051] In one embodiment, based on the suction pressure and suction temperature of the compressor, the property table of the refrigerant used in the air conditioner (e.g., the pressure-temperature-enthalpy-entropy table for R410A, R454B, R32, or other refrigerants) is consulted to obtain the suction specific enthalpy and suction specific entropy of the compressor. The property table is pre-stored in the controller of the air conditioner and can be accessed using the NIST standard.

[0052] In one embodiment, the formula for calculating the isentropic compression endpoint specific enthalpy of the compressor is as follows: based on the definition of an isentropic process in the second law of thermodynamics, Hdis_s = f(Pdis_es, Ssuc), where Hdis_s is the isentropic compression endpoint specific enthalpy of the compressor, Pdis_es is the discharge pressure of the compressor, and Ssuc is the suction specific entropy of the compressor. Here, the function f() is a fitting function determined according to the thermodynamic property table of the refrigerant.

[0053] In one embodiment, the ratio of the compressor's discharge pressure to its intake pressure is calculated to obtain the pressure ratio. Based on this pressure ratio, the compressor's isentropic efficiency is obtained by consulting a compressor isentropic efficiency table. Specifically, the isentropic efficiency table in the compressor's specifications can be used. Different compressors have different efficiencies; this table represents data verified through experiments by the compressor manufacturer during compressor development.

[0054] In one embodiment, the discharge temperature of the compressor is obtained by consulting the property table of the refrigerant (available from the NIST standard) based on the actual discharge specific enthalpy and discharge pressure of the compressor.

[0055] In another alternative, the actual discharge enthalpy of the compressor is determined based on the compressor's intake enthalpy, isentropic compression endpoint enthalpy, and isentropic efficiency. This includes: calculating the difference between the compressor's isentropic compression endpoint enthalpy and its intake enthalpy to obtain a first difference; calculating the ratio of the first difference to the compressor's isentropic efficiency to obtain a first ratio; and adding the compressor's intake enthalpy to the first ratio to obtain the compressor's actual discharge enthalpy.

[0056] In the above embodiments, the enthalpy increase of the ideal isentropic compression process (i.e., the difference between the intake enthalpy and the enthalpy at the end of isentropic compression) is calculated, and then divided by the compressor's isentropic efficiency to obtain the enthalpy increase of the actual compression process. This is then superimposed on the intake enthalpy to obtain the actual exhaust enthalpy. This method is based on the first law of thermodynamics and the compressor's actual compression efficiency model. It quantifies the energy deviation between the theoretical isentropic process and the actual variable compression process, thereby accurately restoring the true enthalpy value of the compressor under the exhaust state. This provides a high-precision basis for subsequently determining the compressor's exhaust temperature and effectively avoids the exhaust temperature estimation deviation caused by ignoring compression efficiency.

[0057] In one embodiment, the actual exhaust enthalpy of the compressor is calculated according to the formula Hdis_calc=Hsuc+(Hdis_s-Hsuc) / ηis, where Hdis_calc is the actual exhaust enthalpy of the compressor, Hsuc is the intake enthalpy of the compressor, Hdis_s is the isentropic compression endpoint enthalpy of the compressor, and ηis is the isentropic efficiency of the compressor.

[0058] According to some exemplary embodiments of this application, the air conditioner further includes a first pressure sensor, a second pressure sensor, and a temperature sensor. The first pressure sensor is disposed at the inlet of the throttling element, and the second pressure sensor and the temperature sensor are both disposed at the outlet of the indoor heat exchanger. Acquiring the pre-throttling pressure, the outlet pressure of the indoor heat exchanger, and the outlet temperature of the indoor heat exchanger includes: acquiring the pre-throttling pressure using the first pressure sensor; acquiring the outlet pressure of the indoor heat exchanger using the second pressure sensor; acquiring the outlet temperature of the indoor heat exchanger using the temperature sensor; and determining the discharge temperature of the compressor based on the pre-throttling pressure, the outlet pressure of the indoor heat exchanger, and the outlet temperature of the indoor heat exchanger, including: determining the initial discharge temperature of the compressor based on the outlet pressure of the indoor heat exchanger, the pre-throttling pressure, and the outlet temperature of the indoor heat exchanger; and determining the discharge temperature of the compressor based on the initial discharge temperature of the compressor and a preset error temperature compensation, wherein the error temperature compensation is at least used to compensate for the detection errors of the first pressure sensor, the second pressure sensor, and the temperature sensor.

[0059] In the above embodiments, by introducing a preset error temperature compensation based on the initial exhaust temperature detected by the first pressure sensor, the second pressure sensor, and the temperature sensor, the systematic measurement error caused by the sensor's own accuracy limitations, installation position deviation, or environmental interference can be directly offset, making the final determined compressor exhaust temperature closer to the true value. This improves the robustness of exhaust temperature estimation without adding extra complex algorithms, ensuring the accuracy of subsequent decision-making for protection control of the throttling element based on this temperature, and effectively preventing false protection or insufficient protection caused by estimation deviation.

[0060] In one embodiment, the sum of the initial discharge temperature of the compressor and the error temperature compensation is determined as the discharge temperature of the compressor.

[0061] In one embodiment, the aforementioned error temperature compensation is used to compensate for the detection error of the first pressure sensor, the detection error of the second pressure sensor, the detection error of the temperature sensor, the compensation error of the high-pressure side pressure compensation, the compensation error of the low-pressure side pressure compensation, the compensation error of the intake pipe temperature rise compensation, and the compressor isentropic efficiency calibration error.

[0062] In practical applications, those skilled in the art can set the above-mentioned error temperature compensation based on empirical values, or it can be obtained through multiple experiments; this application does not impose specific limitations in this regard. In one embodiment, the above-mentioned error temperature compensation is 3°C.

[0063] In one embodiment, the temperature sensor includes a temperature sensing bulb.

[0064] According to some exemplary embodiments of this application, determining the outlet superheat of the indoor heat exchanger based on the outlet pressure and outlet temperature of the indoor heat exchanger includes: determining the saturation temperature corresponding to the outlet pressure of the indoor heat exchanger using the refrigerant property table of the air conditioner; and calculating the difference between the outlet temperature of the indoor heat exchanger and the saturation temperature corresponding to the outlet pressure of the indoor heat exchanger to obtain the outlet superheat of the indoor heat exchanger.

[0065] In the above embodiments, the measured outlet pressure of the indoor heat exchanger is converted into the corresponding saturation temperature by consulting the refrigerant property table, and the difference between the saturation temperature and the measured outlet temperature is calculated. Based on the thermodynamic phase change characteristics of the refrigerant, the superheat state of the refrigerant at the evaporator outlet can be accurately quantified. This provides a physical basis for judging whether the liquid supply to the evaporator is sufficient, ensuring that the subsequent logic for adjusting the opening of the throttling element based on the superheat is based on accurate state parameters, and avoiding the risk of liquid return due to excessively high or low compressor suction temperature caused by excessive superheat.

[0066] In one embodiment, the corresponding saturation temperature is obtained by consulting the refrigerant's property table (available from the NIST standard) based on the outlet pressure of the indoor heat exchanger.

[0067] According to some exemplary embodiments of this application, controlling the opening degree of the throttling element based on the discharge temperature of the compressor and the outlet superheat of the indoor heat exchanger includes: determining whether the outlet superheat of the indoor heat exchanger is less than or equal to a preset outlet superheat threshold; if the outlet superheat of the indoor heat exchanger is less than or equal to the outlet superheat threshold, determining that the outlet superheat of the indoor heat exchanger is insufficient; if the outlet superheat of the indoor heat exchanger is insufficient, determining whether the discharge temperature of the compressor is less than a preset first temperature threshold; and if the discharge temperature of the compressor is not less than the first temperature threshold, controlling the opening degree of the throttling element to remain unchanged or increase.

[0068] In the above embodiments, by introducing the compressor discharge temperature as an arbitration condition for superheat control, when insufficient superheat is detected and the throttling element should be closed to prevent liquid return, if it is also determined that the discharge temperature is above the high limit threshold, the valve closing action is prohibited or the valve opening measure is taken. This avoids the risk of further reduction in refrigerant flow and malignant increase in suction superheat and discharge temperature due to blindly closing the valve under the traditional superheat control logic. This dual-parameter linkage control strategy achieves a balance between ensuring compressor safety (preventing discharge overheat damage) and maintaining system energy efficiency (preventing severe liquid return), significantly improving the operational reliability of the air conditioning system under extreme operating conditions or estimation errors.

[0069] In practical applications, those skilled in the art can set the above-mentioned outlet superheat threshold and the above-mentioned first temperature threshold based on experience, or they can obtain them through multiple experiments. This application does not impose any specific restrictions on this.

[0070] In one embodiment, the outlet superheat threshold is 2°C, and the first temperature threshold is 95°C.

[0071] According to some other exemplary embodiments of this application, controlling the opening degree of the throttling element to remain constant or increase includes: when the discharge temperature of the compressor is not less than the first temperature threshold and less than a preset second temperature threshold, controlling the opening degree of the throttling element to remain constant, wherein the first temperature threshold is less than the second temperature threshold; when the discharge temperature of the compressor is not less than the second temperature threshold and less than a preset third temperature threshold, controlling the opening degree of the throttling element to increase at a preset rate based on the difference between the discharge temperature of the compressor and the second temperature threshold, wherein the second temperature threshold is less than the third temperature threshold; when the discharge temperature of the compressor is not less than the third temperature threshold and continues for a first preset duration, controlling the opening degree of the throttling element to increase to a preset degree, and outputting a fault signal or controlling the compressor to shut down.

[0072] In the above embodiments, by constructing a graded protection and regulation mechanism based on the compressor exhaust temperature, a stepped response is achieved, from maintaining the status quo to active cooling and then to emergency shutdown. When the exhaust temperature just exceeds the first threshold, the valve opening is maintained to keep the system stable and avoid malfunctions. When the temperature rises further to the second threshold range, the throttling element is dynamically opened according to the over-temperature range to increase the refrigerant flow and accelerate compressor cooling, demonstrating the precision and initiative of the control. When the temperature continues to exceed the third threshold, the valve step is forcibly opened and a fault shutdown is triggered to completely block the high-temperature risk. This phased control strategy with hysteresis and time-based judgment not only prevents frequent valve step oscillations caused by slight fluctuations in exhaust temperature, but also provides reliable safety redundancy under extreme high-temperature conditions, ensuring good compressor reliability and system operation safety.

[0073] In practical applications, those skilled in the art can set the above-mentioned second temperature threshold, third temperature threshold, first preset duration, preset rate and preset opening degree based on experience values, or obtain them through multiple experiments. This application does not impose specific limitations on this.

[0074] In one embodiment, the second temperature threshold is 100°C, the third temperature threshold is 105°C, the first preset duration is 120s, the preset rate is 10-20 steps per 60s, and the preset opening is 30-50 steps.

[0075] In other embodiments, controlling the opening degree of the throttling element based on the discharge temperature of the compressor and the outlet superheat of the indoor heat exchanger further includes: if the discharge temperature of the compressor is less than the first temperature threshold, determining whether the discharge temperature of the compressor at the current moment is greater than the discharge temperature of the compressor at the previous moment, wherein the previous moment is prior to the current moment; if the discharge temperature of the compressor at the current moment is greater than the discharge temperature of the compressor at the previous moment, controlling the opening degree of the throttling element to decrease; if the discharge temperature of the compressor at the current moment is less than the discharge temperature of the compressor at the previous moment, determining whether the discharge temperature of the compressor at the current moment is less than a fourth temperature threshold, wherein the fourth temperature threshold is less than the first temperature threshold; if the discharge temperature of the compressor at the current moment is less than the fourth temperature threshold and remains so for a second preset duration, controlling the opening degree of the throttling element to decrease; and if the discharge temperature of the compressor at the current moment is not less than the fourth temperature threshold, the controller of the air conditioner maintains the control command for the throttling element from the previous moment.

[0076] In the above embodiments, by introducing the trend of exhaust temperature change (rising or falling) as the decision basis for adjusting the opening of the throttling element, dynamic adaptive control is achieved within the normal range of exhaust temperature: when the exhaust temperature is rising, the throttling element is immediately closed to suppress further temperature rise, reflecting the timeliness of control; when the exhaust temperature is falling, the valve closing action is only executed after the temperature drops to an extremely low threshold and remains there for a certain period of time, avoiding false valve closing caused by instantaneous temperature fluctuations or normal cooling process. Thus, while ensuring the safety of the compressor exhaust temperature, it prevents the reduction of system efficiency or the risk of liquid return caused by excessive throttling, and improves the stability and robustness of the control logic.

[0077] In practical applications, those skilled in the art can set the aforementioned fourth temperature threshold and the aforementioned second preset duration based on empirical values, or they can obtain them through multiple experiments. This application does not impose specific limitations in this regard. In one embodiment, the aforementioned fourth temperature threshold is 92°C, and the aforementioned second preset duration is 180 seconds.

[0078] In other embodiments, obtaining the pressure before throttling, the outlet pressure of the indoor heat exchanger, and the outlet temperature of the indoor heat exchanger includes: determining whether the compressor's operating time is greater than a preset operating time when the throttling element is open; and obtaining the pressure before throttling, the outlet pressure of the indoor heat exchanger, and the outlet temperature of the indoor heat exchanger when the compressor's operating time is greater than the preset operating time.

[0079] In the above embodiments, by setting a delay judgment mechanism for the compressor start-up time, pressure and temperature data are collected only after the system enters a stable operating state to estimate the exhaust temperature and superheat. This effectively avoids sensor reading distortion caused by unstable refrigerant flow, severe pressure fluctuations, and uneven temperature distribution in the early stage of compressor start-up, significantly improving the accuracy and reliability of the exhaust temperature estimation model and superheat calculation results, and preventing erroneous operation of the throttling element caused by transient data interference.

[0080] In practical applications, those skilled in the art can set the above-mentioned preset activation duration based on experience or through multiple experiments; this application does not impose specific limitations on this. In one embodiment, the above-mentioned preset activation duration is 180 seconds.

[0081] In another embodiment, after acquiring the pre-throttling pressure, the outlet pressure of the indoor heat exchanger, and the outlet temperature of the indoor heat exchanger, and before determining the discharge temperature of the compressor based on the pre-throttling pressure, the outlet pressure of the indoor heat exchanger, and the outlet temperature of the indoor heat exchanger, the method further includes: determining whether a sensor is in an abnormal state, wherein the sensor includes the first pressure sensor, the second pressure sensor, and the temperature sensor, and the abnormal state includes at least one of the following: the pressure of the first pressure sensor is less than a preset minimum pre-throttling pressure threshold, the pressure of the first pressure sensor is greater than a preset maximum pre-throttling pressure threshold, and the pressure of the second pressure sensor is less than a preset minimum discharge temperature threshold. The following conditions are considered: The outlet pressure threshold, the pressure of the second pressure sensor is greater than a preset maximum outlet pressure threshold, the temperature of the temperature sensor is less than a preset minimum outlet temperature threshold, and the temperature of the temperature sensor is greater than a preset maximum outlet temperature threshold; when the sensor is in the above abnormal state, the opening degree of the throttling element is controlled to be not less than a preset minimum opening degree threshold; the discharge temperature of the compressor is determined based on the pre-throttling pressure, the outlet pressure of the indoor heat exchanger, and the outlet temperature of the indoor heat exchanger, including: when the sensor is not in the above abnormal state, the discharge temperature of the compressor is determined based on the pre-throttling pressure, the outlet pressure of the indoor heat exchanger, and the outlet temperature of the indoor heat exchanger.

[0082] In the above embodiments, by constructing an anomaly detection and degradation protection mechanism based on the rationality of sensor data, the system can immediately identify abnormal operating conditions and trigger safety strategies when pressure or temperature sensors malfunction, disconnect, or exceed physical limits. Specifically, it can forcibly maintain the minimum opening of the throttling element to prevent the compressor from overheating or liquid return due to excessively low refrigerant flow. At the same time, this mechanism effectively shields the influence of invalid or erroneous sensor data on the exhaust temperature estimation model, avoids erroneous control commands caused by estimation deviations, and significantly improves the operational safety and robustness of the control logic under abnormal conditions such as sensor failure.

[0083] In one embodiment, the above-mentioned abnormal state further includes at least one of the following: the ratio of the discharge pressure of the compressor to the intake pressure of the compressor is less than a preset minimum pressure ratio threshold, and the ratio of the discharge pressure of the compressor to the intake pressure of the compressor is greater than a preset maximum pressure ratio threshold.

[0084] In practical applications, those skilled in the art can set the minimum pre-throttling pressure threshold, the maximum pre-throttling pressure threshold, the minimum outlet pressure threshold, the maximum outlet pressure threshold, the minimum outlet temperature threshold, the maximum outlet temperature threshold, the minimum pressure ratio threshold, the maximum pressure ratio threshold, and the minimum opening threshold based on empirical values, or obtain them through multiple experiments. This application does not impose specific limitations on these values.

[0085] In one embodiment, the minimum pre-throttling pressure threshold is 0.2 MPa, the maximum pre-throttling pressure threshold is 4.5 MPa, the minimum outlet pressure threshold is 0.1 MPa, the maximum outlet pressure threshold is 2.5 MPa, the minimum outlet temperature threshold is -40°C, the maximum outlet temperature threshold is 80°C, the minimum pressure ratio threshold is 1.2, the maximum pressure ratio threshold is 6.0, and the minimum opening threshold is 240 steps.

[0086] It should be noted that existing electronic expansion valve control schemes are mostly applicable to air conditioning platforms where the indoor and outdoor units have complete communication or the system controller can directly obtain the compressor discharge temperature. For traditional residential units, there is usually only a 24V switching signal between the indoor and outdoor units. The indoor unit control board cannot directly obtain the outdoor unit discharge temperature, therefore it cannot execute valve step protection arbitration based on the actual discharge temperature. Existing superheat control logic typically reduces the opening of the electronic expansion valve when the evaporator outlet superheat is insufficient to prevent compressor liquid return. However, when the compressor discharge temperature is already high, further reducing the electronic expansion valve opening may lead to a decrease in system refrigerant flow, an increase in compressor suction superheat, and insufficient cooling of the compressor motor and discharge side, further increasing the discharge temperature. Therefore, simply... Closing the valve based on insufficient superheat poses a reliability risk. Existing electronic expansion valve controls typically rely on exhaust temperature sensors located on the compressor exhaust pipe or outdoor unit side, or on the outdoor unit control board transmitting exhaust temperature to the indoor unit. In residential units without communication, the indoor unit cannot use this type of control logic without adding a communication line or outdoor unit data interface. Although existing controls can collect signals such as liquid pipe temperature, pressure, and current on the indoor side for system diagnosis, their main purpose is usually fault identification or remote monitoring, not for real-time valve step control of the indoor unit's electronic expansion valve. Furthermore, they do not propose using the pressure before throttling on the indoor unit side, the evaporator outlet pressure, and the evaporator outlet temperature to estimate the compressor exhaust temperature and use the estimated exhaust temperature to constrain the insufficient superheat valve closing logic. Therefore, this application adds a pressure sensor before throttling (i.e., the first pressure sensor mentioned above), an evaporator outlet pressure sensor (i.e., the second pressure sensor mentioned above), and an evaporator outlet temperature sensor (i.e., the temperature sensor mentioned above) to the indoor unit side. The indoor unit controller estimates the compressor discharge temperature based on the refrigerant properties and the compressor's isentropic efficiency. When the estimated discharge temperature is high, it stops or limits the valve closing action caused by insufficient superheat. This allows the indoor unit controller to estimate the outdoor unit compressor discharge temperature without relying on communication between the indoor and outdoor units. The estimated discharge temperature is then used for arbitration in the control of the indoor electronic expansion valve. This solves the problem that the indoor unit cannot obtain the outdoor unit compressor discharge temperature, which causes the indoor electronic expansion valve's valve steps to be unable to be linked with the compressor discharge temperature protection logic.

[0087] The control method for air conditioners described in this application is applicable to residential split air conditioners or heat pump systems, especially to air conditioning platforms where the indoor and outdoor units are connected only via a 24V low-voltage signal and there is no data communication bus. The air conditioning system includes an outdoor unit, an indoor unit, a pre-throttling pressure sensor, an evaporator outlet pressure sensor, an evaporator outlet temperature sensor, and an indoor unit controller. The outdoor unit includes a compressor, an outdoor heat exchanger, and an outdoor fan. The indoor unit includes an indoor heat exchanger, an indoor fan, and an indoor electronic expansion valve (i.e., the aforementioned throttling element). The thermostat sends cooling or heating demands to the system via a 24V signal, such as a cooling demand signal Y. No data such as compressor discharge temperature, compressor discharge pressure, compressor speed, or outdoor fan speed is transmitted between the indoor and outdoor units. The pre-throttling pressure sensor is located on the liquid pipe side before the inlet of the indoor electronic expansion valve and is used to detect the pre-throttling high-pressure side refrigerant pressure Pliq_pre (i.e., the aforementioned pre-throttling pressure). The evaporator outlet pressure sensor is located near the indoor evaporator outlet or suction pipe inlet and is used to detect the evaporator outlet pressure Peva_out (i.e., the aforementioned indoor heat exchanger outlet pressure). The evaporator outlet temperature sensor is installed on the surface of the evaporator outlet pipe to detect the evaporator outlet temperature Teva_out (i.e., the outlet temperature of the indoor heat exchanger mentioned above). The temperature sensor is preferably fixed to the outer wall of the pipe by metal clips and covered with insulation cotton on the outside to reduce the influence of indoor air disturbance on temperature detection.

[0088] In one embodiment, after the air conditioning system enters cooling operation, the indoor unit controller first controls the electronic expansion valve to enter the initial opening degree, for example, 300 steps (if the total number of steps for the electronic expansion valve is 0~480 steps, where 0 steps represent fully closed and 480 steps represent fully open, then the initial opening degree can be set to 280~360 steps according to the indoor unit capacity and the matching capacity of the outdoor unit); within the first 180 seconds after the compressor starts, the controller may not perform the exhaust temperature estimation arbitration, but only perform the start protection valve step to avoid estimation errors caused by system non-steady state; after the compressor has been running for more than 180 seconds, the controller begins to periodically collect pressure and temperature signals, with a sampling period of 5 seconds and a control period of 30 seconds.

[0089] This application also provides a specific embodiment of a control method for an air conditioner, the steps of which include:

[0090] 1) such as Figure 4As shown, the controller first reads the pre-throttling pressure Pliq_pre and obtains the estimated discharge pressure Pdis_est (i.e., the discharge pressure of the compressor mentioned above) based on the high-pressure side pressure compensation ΔP_high. Pdis_est = Pliq_pre + ΔP_high. For example, if Pliq_pre = 2.80 MPa and the high-pressure side compensation ΔP_high = 0.10 MPa, then Pdis_est = 2.90 MPa. Then, it reads the evaporator outlet pressure Peva_out and obtains the estimated suction pressure Psuc_est (i.e., the suction pressure of the compressor mentioned above) based on the low-pressure side pressure compensation ΔP_low. suc_est = Peva_out - ΔP_low. For example, if Peva_out = 0.95MPa and the low-pressure side compensation ΔP_low = 0.03MPa, then Psuc_est = 0.92MPa. The controller reads the evaporator outlet temperature Teva_out and obtains the estimated suction temperature Tsuc_est (i.e., the suction temperature of the compressor mentioned above) based on the suction pipe temperature rise compensation ΔT_suc. Tsuc_est = Teva_out + ΔT_suc. For example, if Teva_out = 12℃ and the suction pipe temperature rise compensation ΔT_suc = 2℃, then Tsuc_est = 14℃.

[0091] 2) For example Figure 4 As shown, the controller queries the property table of the refrigerant used (e.g., the pressure-temperature-enthalpy-entropy table for R410A, R454B, R32, or other refrigerants) based on Psuc_est and Tsuc_est to obtain the suction enthalpy Hsuc and suction entropy Ssuc of the compressor in suction state; then, it calculates the isentropic compression endpoint enthalpy Hdis_s based on Pdis_est and Ssuc; the controller queries the compressor isentropic efficiency table based on the pressure ratio PR = Pdis_est / Psuc_est to obtain the compressor's isentropic efficiency. For example, when PR=3.15, the isentropic efficiency ηis of the compressor can be taken as 0.68. When PR is greater than 3.5, ηis can be taken as 0.63 to improve safety. Then the controller calculates the actual discharge specific enthalpy of the compressor according to the formula Hdis_calc=Hsuc+(Hdis_s-Hsuc) / ηis, and obtains the calculated discharge temperature Tdis_calc (i.e. the initial discharge temperature of the compressor) by querying the refrigerant property table according to Hdis_calc and Pdis_est.

[0092] 3) For example Figure 4As shown, to improve reliability, this embodiment does not directly use Tdis_calc as the control judgment value. Instead, the final estimated exhaust temperature (i.e., the exhaust temperature of the compressor mentioned above) is set to Tdis_est = Tdis_calc + 3℃. For example, when the calculated exhaust temperature Tdis_calc = 93℃, the final estimated exhaust temperature Tdis_est = 96℃. This 3℃ (i.e., the error temperature compensation mentioned above) safety redundancy is used to cover pressure compensation error (i.e., the high-pressure side pressure compensation and the low-pressure side pressure compensation mentioned above), suction pipe temperature rise compensation error, compressor isentropic efficiency calibration error, and sensor (i.e., the first pressure sensor, the second pressure sensor, and the temperature sensor mentioned above) detection error, so that the controller can take protective measures in advance when the exhaust temperature is close to the risk range.

[0093] 4) For example Figure 5 As shown, the controller simultaneously queries the refrigerant property table based on the evaporator outlet pressure Peva_out to obtain the corresponding saturation temperature Tsat_eva, and calculates the evaporator outlet superheat (i.e., the outlet superheat of the aforementioned indoor heat exchanger) SH = Teva_out - Tsat_eva. For example, if Teva_out = 11℃ and the corresponding saturation temperature of Peva_out is 10℃, then SH = 1℃. When SH ≤ 2℃, the traditional superheat control logic usually judges that the superheat is insufficient and needs to reduce the opening of the electronic expansion valve EEV, for example, by closing it 10 steps every 60 seconds to increase the superheat. However, this embodiment adds an arbitration logic for estimating the exhaust temperature: when Tdis_est < 95℃, the valve closing action (i.e., reducing the opening of the electronic expansion valve EEV) is allowed; when Tdis_est ≥ 95℃, the action of closing the electronic expansion valve due to insufficient SH is prohibited, and the electronic expansion valve maintains its current opening; when Tdis_est ≥ 100℃, the controller further enters high exhaust temperature control. In the temperature limit zone, even if SH≤2℃, the controller will not perform valve closing action and can slightly open the electronic expansion valve according to the exhaust temperature deviation; for example, when 100℃≤Tdis_est<105℃, it will open 10 to 20 steps every 60 seconds to increase the refrigerant circulation and reduce the compressor exhaust temperature; when Tdis_est≥105℃ and lasts for 120 seconds, the controller enters the high exhaust temperature protection zone, and can forcibly open the electronic expansion valve 30 to 50 steps, output a fault code, or disconnect the outdoor unit Y signal in a system with Y signal relay control capability to request the outdoor unit to stop for protection.

[0094] 5) To avoid frequent valve step switching, this embodiment sets exhaust temperature hysteresis. The threshold for entering the valve-closing prohibition logic (i.e., the first temperature threshold mentioned above) is 95°C, and the threshold for restoring the valve-closing logic when the normal superheat is insufficient (i.e., the fourth temperature threshold mentioned above) is 92°C. When Tdis_est drops below 92°C and remains below 92°C for 180 seconds, the controller resumes normal superheat closed-loop control. When Tdis_est is between 92°C and 95°C, the controller maintains the previous state (the exhaust temperature rises from low to 95°C before executing the valve-closing prohibition logic; the exhaust temperature decreases from high to 92°C before resuming the valve-closing logic).

[0095] 6) If the sensor malfunctions, for example, the pressure before throttling is lower than 0.2MPa or higher than 4.5MPa, the evaporator outlet pressure is lower than 0.1MPa or higher than 2.5MPa, the evaporator outlet temperature is lower than -40℃ or higher than 80℃, or the pressure ratio PR is less than 1.2 or greater than 6.0, the controller determines that the estimation conditions are abnormal and exits the exhaust temperature estimation arbitration. At this time, the controller can adopt conservative valve step control, for example, limiting the minimum opening of the electronic expansion valve to no less than 240 steps (i.e., the minimum opening threshold mentioned above), and prohibiting rapid continuous valve closing to ensure the safety of the compressor.

[0096] The above-described specific implementation method enables the indoor unit to have the ability to judge the exhaust temperature of the outdoor unit without adding communication lines between the indoor and outdoor units or modifying the outdoor unit control board. This avoids continuing to close the electronic expansion valve when the compressor exhaust temperature is high, thereby improving the reliability of the compressor and the stability of system operation.

[0097] This invention provides a computer-readable storage medium including a stored program, wherein, when the program is executed, it controls the device containing the computer-readable storage medium to perform the control method of the air conditioner.

[0098] Specifically, the air conditioner includes an indoor unit and an outdoor unit. The indoor unit includes a throttling element and an indoor heat exchanger. The outdoor unit includes a compressor. The compressor's suction port is connected to the outlet of the indoor heat exchanger, the compressor's discharge port is connected to the inlet of the throttling element, and the throttling element's outlet is connected to the inlet of the indoor heat exchanger. The air conditioner's control method includes:

[0099] Step S201: Obtain the pressure before throttling, the outlet pressure of the indoor heat exchanger, and the outlet temperature of the indoor heat exchanger. The pressure before throttling represents the pressure at the inlet of the throttling element.

[0100] Step S202: Determine the discharge temperature of the compressor based on the pressure before throttling, the outlet pressure of the indoor heat exchanger, and the outlet temperature of the indoor heat exchanger.

[0101] Step S203: Determine the outlet superheat of the indoor heat exchanger based on the outlet pressure and outlet temperature of the indoor heat exchanger.

[0102] Step S204: Control the opening degree of the throttling element based on the exhaust temperature of the compressor and the outlet superheat of the indoor heat exchanger.

[0103] Optionally, the air conditioner further includes a suction pipe, through which the suction port of the compressor is connected to the outlet of the indoor heat exchanger. The discharge temperature of the compressor is determined based on the pre-throttling pressure, the outlet pressure of the indoor heat exchanger, and the outlet temperature of the indoor heat exchanger. This includes: determining the discharge pressure of the compressor based on the pre-throttling pressure and a preset high-pressure side pressure compensation, whereby the high-pressure side pressure compensation compensates for the pressure loss between the compressor's discharge port and the inlet of the throttling element; determining the suction pressure of the compressor based on the outlet pressure of the indoor heat exchanger and a preset low-pressure side pressure compensation, whereby the low-pressure side pressure compensation compensates for the pressure loss between the outlet of the indoor heat exchanger and the compressor's suction port; determining the suction temperature of the compressor based on the outlet temperature of the indoor heat exchanger and a preset suction pipe temperature rise compensation, whereby the suction pipe temperature rise compensation compensates for the temperature rise caused by the refrigerant absorbing heat in the suction pipe; and determining the discharge temperature of the compressor based on the compressor's discharge pressure, suction pressure, and suction temperature.

[0104] Optionally, determining the discharge temperature of the compressor based on the compressor's discharge pressure, suction pressure, and suction temperature includes: determining the compressor's suction enthalpy and suction entropy based on the compressor's suction pressure and suction temperature; determining the compressor's isentropic compression endpoint enthalpy based on the compressor's discharge pressure and suction entropy; determining the compressor's isentropic efficiency based on the compressor's discharge pressure and suction pressure; determining the compressor's actual discharge enthalpy based on the compressor's suction enthalpy, isentropic compression endpoint enthalpy, and isentropic efficiency; and determining the compressor's discharge temperature based on the compressor's actual discharge enthalpy and discharge pressure.

[0105] Optionally, determining the actual discharge enthalpy of the compressor based on the compressor's intake enthalpy, isentropic compression endpoint enthalpy, and isentropic efficiency includes: calculating the difference between the compressor's isentropic compression endpoint enthalpy and its intake enthalpy to obtain a first difference; calculating the ratio of the first difference to the compressor's isentropic efficiency to obtain a first ratio; and adding the compressor's intake enthalpy to the first ratio to obtain the compressor's actual discharge enthalpy.

[0106] Optionally, the air conditioner further includes a first pressure sensor, a second pressure sensor, and a temperature sensor. The first pressure sensor is disposed at the inlet of the throttling element, and the second pressure sensor and the temperature sensor are both disposed at the outlet of the indoor heat exchanger. Acquiring the pre-throttling pressure, the outlet pressure of the indoor heat exchanger, and the outlet temperature of the indoor heat exchanger includes: acquiring the pre-throttling pressure using the first pressure sensor; acquiring the outlet pressure of the indoor heat exchanger using the second pressure sensor; acquiring the outlet temperature of the indoor heat exchanger using the temperature sensor; and determining the discharge temperature of the compressor based on the pre-throttling pressure, the outlet pressure of the indoor heat exchanger, and the outlet temperature of the indoor heat exchanger. This includes: determining the initial discharge temperature of the compressor based on the outlet pressure of the indoor heat exchanger, the pre-throttling pressure, and the outlet temperature of the indoor heat exchanger; and determining the discharge temperature of the compressor based on the initial discharge temperature of the compressor and a preset error temperature compensation, wherein the error temperature compensation is at least used to compensate for the detection errors of the first pressure sensor, the second pressure sensor, and the temperature sensor.

[0107] Optionally, determining the outlet superheat of the indoor heat exchanger based on its outlet pressure and outlet temperature includes: using the refrigerant property table of the air conditioner to determine the saturation temperature corresponding to the outlet pressure of the indoor heat exchanger; and calculating the difference between the outlet temperature of the indoor heat exchanger and the saturation temperature corresponding to the outlet pressure of the indoor heat exchanger to obtain the outlet superheat of the indoor heat exchanger.

[0108] Optionally, controlling the opening of the throttling element based on the discharge temperature of the compressor and the outlet superheat of the indoor heat exchanger includes: determining whether the outlet superheat of the indoor heat exchanger is less than or equal to a preset outlet superheat threshold; if the outlet superheat of the indoor heat exchanger is less than or equal to the outlet superheat threshold, determining that the outlet superheat of the indoor heat exchanger is insufficient; if the outlet superheat of the indoor heat exchanger is insufficient, determining whether the discharge temperature of the compressor is less than a preset first temperature threshold; and if the discharge temperature of the compressor is not less than the first temperature threshold, controlling the opening of the throttling element to remain unchanged or increase.

[0109] Optionally, controlling the opening degree of the throttling element to remain constant or increase includes: when the discharge temperature of the compressor is not less than the first temperature threshold and less than a preset second temperature threshold, controlling the opening degree of the throttling element to remain constant, wherein the first temperature threshold is less than the second temperature threshold; when the discharge temperature of the compressor is not less than the second temperature threshold and less than a preset third temperature threshold, controlling the opening degree of the throttling element to increase at a preset rate based on the difference between the discharge temperature of the compressor and the second temperature threshold, wherein the second temperature threshold is less than the third temperature threshold; when the discharge temperature of the compressor is not less than the third temperature threshold and remains so for a first preset duration, controlling the opening degree of the throttling element to increase to a preset degree, and outputting a fault signal or controlling the compressor to shut down.

[0110] Optionally, controlling the opening degree of the throttling element based on the discharge temperature of the compressor and the outlet superheat of the indoor heat exchanger further includes: if the discharge temperature of the compressor is less than the first temperature threshold, determining whether the discharge temperature of the compressor at the current moment is greater than the discharge temperature of the compressor at the previous moment, wherein the previous moment is prior to the current moment; if the discharge temperature of the compressor at the current moment is greater than the discharge temperature of the compressor at the previous moment, controlling the opening degree of the throttling element to decrease; if the discharge temperature of the compressor at the current moment is less than the discharge temperature of the compressor at the previous moment, determining whether the discharge temperature of the compressor at the current moment is less than a fourth temperature threshold, wherein the fourth temperature threshold is less than the first temperature threshold; if the discharge temperature of the compressor at the current moment is less than the fourth temperature threshold and remains so for a second preset duration, controlling the opening degree of the throttling element to decrease; and if the discharge temperature of the compressor at the current moment is not less than the fourth temperature threshold, the controller of the air conditioner maintains the control command for the throttling element from the previous moment.

[0111] Optionally, obtaining the pressure before throttling, the outlet pressure of the indoor heat exchanger, and the outlet temperature of the indoor heat exchanger includes: determining whether the compressor's operating time is greater than a preset operating time when the throttling element is open; and obtaining the pressure before throttling, the outlet pressure of the indoor heat exchanger, and the outlet temperature of the indoor heat exchanger when the compressor's operating time is greater than the preset operating time.

[0112] Optionally, after acquiring the pre-throttling pressure, the outlet pressure of the indoor heat exchanger, and the outlet temperature of the indoor heat exchanger, and before determining the discharge temperature of the compressor based on the pre-throttling pressure, the outlet pressure of the indoor heat exchanger, and the outlet temperature of the indoor heat exchanger, the method further includes: determining whether a sensor is in an abnormal state, wherein the sensor includes the first pressure sensor, the second pressure sensor, and the temperature sensor, and the abnormal state includes at least one of the following: the pressure of the first pressure sensor is less than a preset minimum pre-throttling pressure threshold, the pressure of the first pressure sensor is greater than a preset maximum pre-throttling pressure threshold, and the pressure of the second pressure sensor is less than a preset minimum outlet pressure. The following conditions are considered: a pressure threshold, the pressure of the second pressure sensor being greater than a preset maximum outlet pressure threshold, the temperature of the temperature sensor being less than a preset minimum outlet temperature threshold, and the temperature of the temperature sensor being greater than a preset maximum outlet temperature threshold; when the sensor is in the above-mentioned abnormal state, controlling the opening degree of the throttling element to be not less than a preset minimum opening degree threshold; determining the discharge temperature of the compressor based on the pre-throttling pressure, the outlet pressure of the indoor heat exchanger, and the outlet temperature of the indoor heat exchanger, including: when the sensor is not in the above-mentioned abnormal state, determining the discharge temperature of the compressor based on the pre-throttling pressure, the outlet pressure of the indoor heat exchanger, and the outlet temperature of the indoor heat exchanger.

[0113] This application also provides a computer program product, which, when executed on a data processing device, is suitable for executing an initialization program having at least the following method steps: Step S201, obtaining the pre-throttling pressure, the outlet pressure of the indoor heat exchanger, and the outlet temperature of the indoor heat exchanger, wherein the pre-throttling pressure characterizes the pressure at the inlet of the throttling element; Step S202, determining the discharge temperature of the compressor based on the pre-throttling pressure, the outlet pressure of the indoor heat exchanger, and the outlet temperature of the indoor heat exchanger; Step S203, determining the outlet superheat of the indoor heat exchanger based on the outlet pressure of the indoor heat exchanger and the outlet temperature of the indoor heat exchanger; Step S204, controlling the opening degree of the throttling element based on the discharge temperature of the compressor and the outlet superheat of the indoor heat exchanger.

[0114] Optionally, the air conditioner further includes a suction pipe, through which the suction port of the compressor is connected to the outlet of the indoor heat exchanger. The discharge temperature of the compressor is determined based on the pre-throttling pressure, the outlet pressure of the indoor heat exchanger, and the outlet temperature of the indoor heat exchanger. This includes: determining the discharge pressure of the compressor based on the pre-throttling pressure and a preset high-pressure side pressure compensation, whereby the high-pressure side pressure compensation compensates for the pressure loss between the compressor's discharge port and the inlet of the throttling element; determining the suction pressure of the compressor based on the outlet pressure of the indoor heat exchanger and a preset low-pressure side pressure compensation, whereby the low-pressure side pressure compensation compensates for the pressure loss between the outlet of the indoor heat exchanger and the compressor's suction port; determining the suction temperature of the compressor based on the outlet temperature of the indoor heat exchanger and a preset suction pipe temperature rise compensation, whereby the suction pipe temperature rise compensation compensates for the temperature rise caused by the refrigerant absorbing heat in the suction pipe; and determining the discharge temperature of the compressor based on the compressor's discharge pressure, suction pressure, and suction temperature.

[0115] Optionally, determining the discharge temperature of the compressor based on the compressor's discharge pressure, suction pressure, and suction temperature includes: determining the compressor's suction enthalpy and suction entropy based on the compressor's suction pressure and suction temperature; determining the compressor's isentropic compression endpoint enthalpy based on the compressor's discharge pressure and suction entropy; determining the compressor's isentropic efficiency based on the compressor's discharge pressure and suction pressure; determining the compressor's actual discharge enthalpy based on the compressor's suction enthalpy, isentropic compression endpoint enthalpy, and isentropic efficiency; and determining the compressor's discharge temperature based on the compressor's actual discharge enthalpy and discharge pressure.

[0116] Optionally, determining the actual discharge enthalpy of the compressor based on the compressor's intake enthalpy, isentropic compression endpoint enthalpy, and isentropic efficiency includes: calculating the difference between the compressor's isentropic compression endpoint enthalpy and its intake enthalpy to obtain a first difference; calculating the ratio of the first difference to the compressor's isentropic efficiency to obtain a first ratio; and adding the compressor's intake enthalpy to the first ratio to obtain the compressor's actual discharge enthalpy.

[0117] Optionally, the air conditioner further includes a first pressure sensor, a second pressure sensor, and a temperature sensor. The first pressure sensor is disposed at the inlet of the throttling element, and the second pressure sensor and the temperature sensor are both disposed at the outlet of the indoor heat exchanger. Acquiring the pre-throttling pressure, the outlet pressure of the indoor heat exchanger, and the outlet temperature of the indoor heat exchanger includes: acquiring the pre-throttling pressure using the first pressure sensor; acquiring the outlet pressure of the indoor heat exchanger using the second pressure sensor; acquiring the outlet temperature of the indoor heat exchanger using the temperature sensor; and determining the discharge temperature of the compressor based on the pre-throttling pressure, the outlet pressure of the indoor heat exchanger, and the outlet temperature of the indoor heat exchanger. This includes: determining the initial discharge temperature of the compressor based on the outlet pressure of the indoor heat exchanger, the pre-throttling pressure, and the outlet temperature of the indoor heat exchanger; and determining the discharge temperature of the compressor based on the initial discharge temperature of the compressor and a preset error temperature compensation, wherein the error temperature compensation is at least used to compensate for the detection errors of the first pressure sensor, the second pressure sensor, and the temperature sensor.

[0118] Optionally, determining the outlet superheat of the indoor heat exchanger based on its outlet pressure and outlet temperature includes: using the refrigerant property table of the air conditioner to determine the saturation temperature corresponding to the outlet pressure of the indoor heat exchanger; and calculating the difference between the outlet temperature of the indoor heat exchanger and the saturation temperature corresponding to the outlet pressure of the indoor heat exchanger to obtain the outlet superheat of the indoor heat exchanger.

[0119] Optionally, controlling the opening of the throttling element based on the discharge temperature of the compressor and the outlet superheat of the indoor heat exchanger includes: determining whether the outlet superheat of the indoor heat exchanger is less than or equal to a preset outlet superheat threshold; if the outlet superheat of the indoor heat exchanger is less than or equal to the outlet superheat threshold, determining that the outlet superheat of the indoor heat exchanger is insufficient; if the outlet superheat of the indoor heat exchanger is insufficient, determining whether the discharge temperature of the compressor is less than a preset first temperature threshold; and if the discharge temperature of the compressor is not less than the first temperature threshold, controlling the opening of the throttling element to remain unchanged or increase.

[0120] Optionally, controlling the opening degree of the throttling element to remain constant or increase includes: when the discharge temperature of the compressor is not less than the first temperature threshold and less than a preset second temperature threshold, controlling the opening degree of the throttling element to remain constant, wherein the first temperature threshold is less than the second temperature threshold; when the discharge temperature of the compressor is not less than the second temperature threshold and less than a preset third temperature threshold, controlling the opening degree of the throttling element to increase at a preset rate based on the difference between the discharge temperature of the compressor and the second temperature threshold, wherein the second temperature threshold is less than the third temperature threshold; when the discharge temperature of the compressor is not less than the third temperature threshold and remains so for a first preset duration, controlling the opening degree of the throttling element to increase to a preset degree, and outputting a fault signal or controlling the compressor to shut down.

[0121] Optionally, controlling the opening degree of the throttling element based on the discharge temperature of the compressor and the outlet superheat of the indoor heat exchanger further includes: if the discharge temperature of the compressor is less than the first temperature threshold, determining whether the discharge temperature of the compressor at the current moment is greater than the discharge temperature of the compressor at the previous moment, wherein the previous moment is prior to the current moment; if the discharge temperature of the compressor at the current moment is greater than the discharge temperature of the compressor at the previous moment, controlling the opening degree of the throttling element to decrease; if the discharge temperature of the compressor at the current moment is less than the discharge temperature of the compressor at the previous moment, determining whether the discharge temperature of the compressor at the current moment is less than a fourth temperature threshold, wherein the fourth temperature threshold is less than the first temperature threshold; if the discharge temperature of the compressor at the current moment is less than the fourth temperature threshold and remains so for a second preset duration, controlling the opening degree of the throttling element to decrease; and if the discharge temperature of the compressor at the current moment is not less than the fourth temperature threshold, the controller of the air conditioner maintains the control command for the throttling element from the previous moment.

[0122] Optionally, obtaining the pressure before throttling, the outlet pressure of the indoor heat exchanger, and the outlet temperature of the indoor heat exchanger includes: determining whether the compressor's operating time is greater than a preset operating time when the throttling element is open; and obtaining the pressure before throttling, the outlet pressure of the indoor heat exchanger, and the outlet temperature of the indoor heat exchanger when the compressor's operating time is greater than the preset operating time.

[0123] Optionally, after acquiring the pre-throttling pressure, the outlet pressure of the indoor heat exchanger, and the outlet temperature of the indoor heat exchanger, and before determining the discharge temperature of the compressor based on the pre-throttling pressure, the outlet pressure of the indoor heat exchanger, and the outlet temperature of the indoor heat exchanger, the method further includes: determining whether a sensor is in an abnormal state, wherein the sensor includes the first pressure sensor, the second pressure sensor, and the temperature sensor, and the abnormal state includes at least one of the following: the pressure of the first pressure sensor is less than a preset minimum pre-throttling pressure threshold, the pressure of the first pressure sensor is greater than a preset maximum pre-throttling pressure threshold, and the pressure of the second pressure sensor is less than a preset minimum outlet pressure. The following conditions are considered: a pressure threshold, the pressure of the second pressure sensor being greater than a preset maximum outlet pressure threshold, the temperature of the temperature sensor being less than a preset minimum outlet temperature threshold, and the temperature of the temperature sensor being greater than a preset maximum outlet temperature threshold; when the sensor is in the above-mentioned abnormal state, controlling the opening degree of the throttling element to be not less than a preset minimum opening degree threshold; determining the discharge temperature of the compressor based on the pre-throttling pressure, the outlet pressure of the indoor heat exchanger, and the outlet temperature of the indoor heat exchanger, including: when the sensor is not in the above-mentioned abnormal state, determining the discharge temperature of the compressor based on the pre-throttling pressure, the outlet pressure of the indoor heat exchanger, and the outlet temperature of the indoor heat exchanger.

[0124] This application embodiment also provides an air conditioning system, including: an air conditioner, including an indoor unit and an outdoor unit, the indoor unit including a throttling element and an indoor heat exchanger, the outdoor unit including a compressor, the compressor's suction port being connected to the outlet of the indoor heat exchanger, the compressor's discharge port being connected to the inlet of the throttling element, and the throttling element's outlet being connected to the inlet of the indoor heat exchanger; and a controller, communicatively connected to the air conditioner, the controller including: one or more processors, a memory, and one or more programs, wherein the one or more programs are stored in the memory and configured to be executed by the one or more processors, and the one or more programs include a control method for performing any of the above-described air conditioner.

[0125] It is obvious to those skilled in the art that the modules or steps of the present invention described above can be implemented using general-purpose computing devices. They can be centralized on a single computing device or distributed across a network of multiple computing devices. They can be implemented using computer-executable program code, and thus can be stored in a storage device for execution by a computing device. In some cases, the steps shown or described can be performed in a different order than those described herein, or they can be fabricated as separate integrated circuit modules, or multiple modules or steps can be fabricated as a single integrated circuit module. Thus, the present invention is not limited to any particular combination of hardware and software.

[0126] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0127] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0128] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0129] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0130] In a typical configuration, a computing device includes one or more processors (CPU), input / output interfaces, network interfaces, and memory.

[0131] Memory may include non-persistent memory in computer-readable media, such as random access memory (RAM) and / or non-volatile memory, such as read-only memory (ROM) or flash RAM. Memory is an example of computer-readable media.

[0132] Computer-readable media includes both permanent and non-permanent, removable and non-removable media that can store information using any method or technology. Information can be computer-readable instructions, data structures, modules of programs, or other data. Examples of computer storage media include, but are not limited to, phase-change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, CD-ROM, digital versatile optical disc (DVD) or other optical storage, magnetic tape, disk storage or other magnetic storage devices, or any other non-transferable medium that can be used to store information accessible by a computing device. As defined herein, computer-readable media does not include transient computer-readable media, such as modulated data signals and carrier waves.

[0133] 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 specification.

[0134] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0135] As can be seen from the above description, the embodiments of this application achieve the following technical effects:

[0136] In the air conditioner control method of this application, the pressure before throttling, the outlet pressure and outlet temperature of the indoor heat exchanger are first obtained. Then, the discharge temperature of the compressor is determined based on the pressure before throttling, the outlet pressure and outlet temperature of the indoor heat exchanger. Next, the outlet superheat of the indoor heat exchanger is determined based on the outlet pressure and outlet temperature of the indoor heat exchanger. Finally, the opening degree of the throttling element is controlled based on the discharge temperature of the compressor and the outlet superheat of the indoor heat exchanger. To address the issue of low reliability in existing air conditioning systems, this application indirectly derives the compressor's discharge temperature by acquiring the pre-throttling pressure (characterizing the inlet pressure of the throttling element), the outlet pressure of the indoor heat exchanger, and the outlet temperature. This allows the indoor unit to monitor the compressor's discharge status without relying on communication between the indoor and outdoor units or sensors in the outdoor unit. Simultaneously, by combining the outlet pressure and temperature of the indoor heat exchanger to determine the outlet superheat, the opening of the throttling element is controlled collaboratively based on the compressor's discharge temperature and the indoor heat exchanger's superheat. This control logic, based on the dual parameters of compressor discharge temperature and indoor heat exchanger superheat, prevents compressor refrigerant return (determined by superheat) while avoiding blindly closing the throttling element due to excessively high discharge temperature. This optimizes refrigerant flow while ensuring the compressor discharge temperature remains within a safe range, thereby improving the system's reliability and stability.

[0137] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A control method for an air conditioner, characterized in that, The air conditioner includes an indoor unit and an outdoor unit. The indoor unit includes a throttling element and an indoor heat exchanger. The outdoor unit includes a compressor. The compressor's suction port is connected to the outlet of the indoor heat exchanger, the compressor's discharge port is connected to the inlet of the throttling element, and the throttling element's outlet is connected to the inlet of the indoor heat exchanger. Upon receiving a cooling demand signal or a heating demand signal, the indoor unit and the outdoor unit do not transmit the compressor's discharge temperature and discharge pressure. The method includes: The pressure before throttling, the outlet pressure of the indoor heat exchanger, and the outlet temperature of the indoor heat exchanger are obtained, wherein the pressure before throttling represents the pressure at the inlet of the throttling element; The discharge temperature of the compressor is determined based on the pre-throttling pressure, the outlet pressure of the indoor heat exchanger, the outlet temperature of the indoor heat exchanger, and the isentropic efficiency of the compressor. The outlet superheat of the indoor heat exchanger is determined based on the outlet pressure and the outlet temperature of the indoor heat exchanger. The opening degree of the throttling element is controlled based on the compressor's exhaust temperature and the outlet superheat of the indoor heat exchanger. Controlling the opening degree of the throttling element based on the compressor's exhaust temperature and the outlet superheat of the indoor heat exchanger includes: Determine whether the outlet superheat of the indoor heat exchanger is less than or equal to a preset outlet superheat threshold. If the outlet superheat of the indoor heat exchanger is less than or equal to the outlet superheat threshold, it is determined that the outlet superheat of the indoor heat exchanger is insufficient. If the outlet superheat of the indoor heat exchanger is insufficient, determine whether the exhaust temperature of the compressor is less than a preset first temperature threshold. If the discharge temperature of the compressor is less than the first temperature threshold, determine whether the discharge temperature of the compressor at the current moment is greater than the discharge temperature of the compressor at the previous moment, wherein the previous moment is before the current moment. If the discharge temperature of the compressor at the current moment is greater than the discharge temperature of the compressor at the previous moment, the opening degree of the throttling element is reduced. If the discharge temperature of the compressor at the current moment is lower than the discharge temperature of the compressor at the previous moment, determine whether the discharge temperature of the compressor at the current moment is lower than a fourth temperature threshold, wherein the fourth temperature threshold is lower than the first temperature threshold. If the compressor's exhaust temperature is lower than the fourth temperature threshold at the current moment and remains so for a second preset duration, the opening degree of the throttling element is controlled to decrease. If the compressor's exhaust temperature is not less than the fourth temperature threshold at the current moment, the air conditioner's controller maintains the control command given to the throttling element at the previous moment.

2. The control method for an air conditioner according to claim 1, characterized in that, The air conditioner also includes an intake pipe, through which the intake port of the compressor is connected to the outlet of the indoor heat exchanger. The discharge temperature of the compressor is determined based on the pre-throttling pressure, the outlet pressure of the indoor heat exchanger, the outlet temperature of the indoor heat exchanger, and the isentropic efficiency of the compressor, including: The discharge pressure of the compressor is determined based on the pre-throttling pressure and the preset high-pressure side pressure compensation. The high-pressure side pressure compensation is used to compensate for the pressure loss between the discharge port of the compressor and the inlet of the throttling element. The suction pressure of the compressor is determined based on the outlet pressure of the indoor heat exchanger and the preset low-pressure side pressure compensation. The low-pressure side pressure compensation is used to compensate for the pressure loss between the outlet of the indoor heat exchanger and the suction port of the compressor. The suction temperature of the compressor is determined based on the outlet temperature of the indoor heat exchanger and the preset suction pipe temperature rise compensation. The suction pipe temperature rise compensation is used to compensate for the temperature rise caused by the refrigerant of the air conditioner absorbing heat in the suction pipe. The discharge temperature of the compressor is determined based on the compressor's discharge pressure, suction pressure, suction temperature, and isentropic efficiency.

3. The control method for an air conditioner according to claim 2, characterized in that, The discharge temperature of the compressor is determined based on the compressor's discharge pressure, suction pressure, suction temperature, and isentropic efficiency, including: Based on the compressor's suction pressure and suction temperature, determine the compressor's suction specific enthalpy and suction specific entropy; The isentropic compression endpoint specific enthalpy of the compressor is determined based on the compressor's discharge pressure and intake specific entropy. The isentropic efficiency of the compressor is determined based on the compressor's discharge pressure and suction pressure. The actual discharge enthalpy of the compressor is determined based on the compressor's intake enthalpy, isentropic compression endpoint enthalpy, and isentropic efficiency. The discharge temperature of the compressor is determined based on the actual discharge specific enthalpy and discharge pressure of the compressor.

4. The control method for an air conditioner according to claim 3, characterized in that, The actual discharge enthalpy of the compressor is determined based on the compressor's intake enthalpy, isentropic compression endpoint enthalpy, and isentropic efficiency, including: The difference between the isentropic compression endpoint enthalpy of the compressor and the suction enthalpy of the compressor is calculated to obtain the first difference value; Calculate the ratio of the first difference to the isentropic efficiency of the compressor to obtain the first ratio; The actual exhaust enthalpy of the compressor is obtained by adding the intake enthalpy of the compressor to the first ratio.

5. The control method for an air conditioner according to claim 1, characterized in that, The air conditioner also includes a first pressure sensor, a second pressure sensor, and a temperature sensor. The first pressure sensor is located at the inlet of the throttling element, and the second pressure sensor and the temperature sensor are both located at the outlet of the indoor heat exchanger. Obtaining the pressure before throttling, the outlet pressure of the indoor heat exchanger, and the outlet temperature of the indoor heat exchanger includes: obtaining the pressure before throttling using a first pressure sensor; obtaining the outlet pressure of the indoor heat exchanger using a second pressure sensor; and obtaining the outlet temperature of the indoor heat exchanger using a temperature sensor. The discharge temperature of the compressor is determined based on the pre-throttling pressure, the outlet pressure of the indoor heat exchanger, the outlet temperature of the indoor heat exchanger, and the isentropic efficiency of the compressor. This includes: determining the initial discharge temperature of the compressor based on the outlet pressure of the indoor heat exchanger, the pre-throttling pressure, the outlet temperature of the indoor heat exchanger, and the isentropic efficiency of the compressor; and determining the discharge temperature of the compressor based on the initial discharge temperature and a preset error temperature compensation, wherein the error temperature compensation is used at least to compensate for the detection errors of the first pressure sensor, the second pressure sensor, and the temperature sensor.

6. The control method for an air conditioner according to claim 1, characterized in that, Determining the outlet superheat of the indoor heat exchanger based on its outlet pressure and outlet temperature includes: Using the refrigerant property table of the air conditioner, determine the saturation temperature corresponding to the outlet pressure of the indoor heat exchanger; The difference between the outlet temperature of the indoor heat exchanger and the saturation temperature corresponding to the outlet pressure of the indoor heat exchanger is calculated to obtain the outlet superheat of the indoor heat exchanger.

7. The control method for an air conditioner according to claim 1, characterized in that, Controlling the opening degree of the throttling element based on the compressor's exhaust temperature and the outlet superheat of the indoor heat exchanger further includes: When the exhaust temperature of the compressor is not less than the first temperature threshold, the opening degree of the throttling element is controlled to remain unchanged or increase.

8. The control method for an air conditioner according to claim 7, characterized in that, Controlling the opening degree of the throttling element to remain constant or increase includes: When the exhaust temperature of the compressor is not less than the first temperature threshold and less than the preset second temperature threshold, the opening degree of the throttling element is kept constant, and the first temperature threshold is less than the second temperature threshold. When the discharge temperature of the compressor is not less than the second temperature threshold and less than the preset third temperature threshold, the opening of the throttling element is controlled to increase at a preset rate according to the difference between the discharge temperature of the compressor and the second temperature threshold, wherein the second temperature threshold is less than the third temperature threshold. If the exhaust temperature of the compressor is not less than the third temperature threshold and remains so for a first preset duration, the opening degree of the throttling element is increased by a preset degree, and a fault signal is output or the compressor is shut down.

9. The control method for an air conditioner according to claim 1, characterized in that, Obtaining the pressure before throttling, the outlet pressure of the indoor heat exchanger, and the outlet temperature of the indoor heat exchanger includes: When the throttling element is open, determine whether the compressor's operating time is greater than a preset operating time; When the compressor's start-up duration exceeds the preset start-up duration, the pre-throttling pressure, the outlet pressure of the indoor heat exchanger, and the outlet temperature of the indoor heat exchanger are obtained.

10. The control method for an air conditioner according to claim 5, characterized in that, After acquiring the pre-throttling pressure, the outlet pressure of the indoor heat exchanger, and the outlet temperature of the indoor heat exchanger, and before determining the compressor's discharge temperature based on the pre-throttling pressure, the outlet pressure of the indoor heat exchanger, the outlet temperature of the indoor heat exchanger, and the isentropic efficiency of the compressor, the method further includes: determining whether a sensor is in an abnormal state, the sensor including a first pressure sensor, a second pressure sensor, and a temperature sensor, the abnormal state including at least one of the following: the pressure of the first pressure sensor is less than a preset minimum pre-throttling pressure threshold, the pressure of the first pressure sensor is greater than a preset maximum pre-throttling pressure threshold, the pressure of the second pressure sensor is less than a preset minimum outlet pressure threshold, the pressure of the second pressure sensor is greater than a preset maximum outlet pressure threshold, the temperature of the temperature sensor is less than a preset minimum outlet temperature threshold, and the temperature of the temperature sensor is greater than a preset maximum outlet temperature threshold; when the sensor is in the abnormal state, controlling the opening degree of the throttling element to be not less than a preset minimum opening degree threshold; Determining the discharge temperature of the compressor based on the pre-throttling pressure, the outlet pressure of the indoor heat exchanger, the outlet temperature of the indoor heat exchanger, and the isentropic efficiency of the compressor includes: when the sensor is not in the abnormal state, determining the discharge temperature of the compressor based on the pre-throttling pressure, the outlet pressure of the indoor heat exchanger, the outlet temperature of the indoor heat exchanger, and the isentropic efficiency of the compressor.

11. A computer-readable storage medium, characterized in that, The computer-readable storage medium includes a stored program, wherein, when the program is executed, it controls the device on which the computer-readable storage medium is located to perform the control method of the air conditioner according to any one of claims 1 to 10.

12. A computer program product comprising computer instructions, characterized in that, When the computer instructions are executed by the processor, they implement the control method of the air conditioner according to any one of claims 1 to 10.

13. An air conditioning system, characterized in that, include: An air conditioner includes an indoor unit and an outdoor unit. The indoor unit includes a throttling element and an indoor heat exchanger. The outdoor unit includes a compressor. The compressor's suction port is connected to the outlet of the indoor heat exchanger, the compressor's discharge port is connected to the inlet of the throttling element, and the throttling element's outlet is connected to the inlet of the indoor heat exchanger. A controller, communicatively connected to the air conditioner, the controller comprising: one or more processors, a memory, and one or more programs, wherein the one or more programs are stored in the memory and configured to be executed by the one or more processors, the one or more programs comprising a control method for performing the air conditioner according to any one of claims 1 to 10.

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