Air conditioning system, pressure detection method and device thereof and storage medium

Abstract

The invention discloses an air conditioning system, a pressure detection method and device thereof and a storage medium, and the method comprises the steps: obtaining the system evaporation pressure detected by a pressure sensor and used for controlling a compressor under the condition that the air conditioning system is in a refrigeration mode; determining system condensation pressure for controlling an outdoor fan according to the system evaporation pressure and the compressor characteristic parameters; and under the condition that the air conditioning system is in the heating mode, the system condensation pressure detected by the pressure sensor and used for controlling the compressor is obtained, and the system evaporation pressure used for controlling the outdoor fan is determined according to the system condensation pressure and the compressor characteristic parameters. A pressure sensor is adopted for pressure monitoring, the evaporation pressure of the system is detected in a refrigeration mode, and the condensation pressure of the system is detected in a heating mode, so that the condensation pressure of the system in the refrigeration mode and the evaporation pressure of the system in the heating mode are obtained through calculation of characteristic parameters of a compressor; and the fuzzy control mode of the fan can be met, and the cost is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of air conditioning, and in particular to an air conditioning system and a pressure detection method, device and storage medium thereof. Background Art

[0002] In a multi-split air conditioning system, at least two pressure sensors are required, one installed on the suction pipe of the compressor to detect the system evaporation pressure, and the other installed on the exhaust pipe of the compressor to detect the system condensation pressure. In cooling mode, the compressor frequency is controlled according to the detected system evaporation pressure, and the fan speed is controlled according to the detected system condensation pressure. In heating mode, the compressor frequency is controlled according to the detected system condensation pressure, and the fan speed is controlled according to the detected system evaporation pressure.

[0003] However, a fuzzy control method is usually used for fan control, which does not require very precise system condensing pressure or system evaporating pressure control. Therefore, in practical applications, two pressure sensors are not necessarily required to monitor relevant pressure values. Summary of the invention

[0004] The purpose of the present invention is to propose an air conditioning system and its pressure detection method, device and storage medium in view of the above-mentioned deficiencies in the prior art, and this purpose is achieved through the following technical solutions.

[0005] A first aspect of the present invention provides a pressure detection method, the method comprising:

[0006] When the air-conditioning system is in cooling mode, obtaining a system evaporation pressure detected by a pressure sensor for controlling a compressor, and determining a system condensation pressure for controlling an outdoor fan according to the detected system evaporation pressure and a characteristic parameter of the compressor;

[0007] When the air-conditioning system is in heating mode, the system condensing pressure detected by the pressure sensor for controlling the compressor is obtained, and the system evaporating pressure for controlling the outdoor fan is determined according to the detected system condensing pressure and the compressor characteristic parameters.

[0008] In some embodiments of the present application, determining the system condensing pressure for controlling the outdoor fan according to the detected system evaporation pressure and the compressor characteristic parameter includes:

[0009] Calculating a virtual condensing pressure using the system evaporation pressure and the compressor characteristic parameter; the compressor characteristic parameter includes at least one of the input power of the compressor, the exhaust temperature of the compressor, and the suction temperature of the compressor;

[0010] Determining a frequency change degree of the compressor according to two consecutive detected compressor operating frequencies;

[0011] The system condensing pressure is determined according to the virtual condensing pressure and the frequency change degree.

[0012] In some embodiments of the present application, the calculating of the virtual condensing pressure by using the system evaporation pressure and the compressor characteristic parameter includes:

[0013] Obtaining a saturation temperature corresponding to the evaporation pressure of the system;

[0014] The virtual condensing pressure is calculated according to the saturation temperature, the compressor characteristic parameter and a preset first fitting relationship; the first fitting relationship is used to calculate the virtual condensing pressure of the air-conditioning system in the cooling mode.

[0015] In some embodiments of the present application, determining the system condensing pressure according to the virtual condensing pressure and the frequency change degree includes:

[0016] When the frequency variation degree is less than a preset threshold, the system condensing pressure is determined by using the internal temperature and outlet temperature of the outdoor heat exchanger and the saturation temperature corresponding to the virtual condensing pressure;

[0017] When the frequency change degree is greater than or equal to a preset threshold, the virtual condensing pressure is used as the system condensing pressure.

[0018] In some embodiments of the present application, the method of determining the system condensing pressure by using the internal temperature and outlet temperature of the outdoor heat exchanger and the saturation temperature corresponding to the virtual condensing pressure includes:

[0019] Calculating the saturation temperature of the system condensing pressure according to the internal temperature and outlet temperature of the outdoor heat exchanger and the saturation temperature corresponding to the virtual condensing pressure;

[0020] The system condensing pressure is obtained according to the saturation temperature of the system condensing pressure.

[0021] In some embodiments of the present application, determining the system evaporation pressure for controlling the outdoor fan according to the detected system condensing pressure and the compressor characteristic parameter includes:

[0022] Calculating a virtual evaporation pressure using the system condensing pressure and the compressor characteristic parameter; the compressor characteristic parameter includes at least one of the input power of the compressor, the exhaust temperature of the compressor, and the suction temperature of the compressor;

[0023] Determining a frequency change degree of the compressor according to two consecutive detected compressor operating frequencies;

[0024] The system evaporation pressure is determined according to the virtual evaporation pressure and the frequency change degree.

[0025] In some embodiments of the present application, the calculating of the virtual evaporation pressure by using the system condensing pressure and the compressor characteristic parameter includes:

[0026] Obtaining a saturation temperature corresponding to the condensing pressure of the system;

[0027] The virtual evaporation pressure is calculated according to the saturation temperature, the compressor characteristic parameter and a preset second fitting relationship; the second fitting relationship is used to calculate the virtual evaporation pressure of the air-conditioning system in the heating mode.

[0028] In some embodiments of the present application, determining the system evaporation pressure according to the virtual evaporation pressure and the frequency change degree includes:

[0029] When the frequency variation degree is less than a preset threshold, the system evaporation pressure is determined by using the internal temperature and inlet temperature of the outdoor heat exchanger and the saturation temperature corresponding to the virtual evaporation pressure;

[0030] When the frequency variation degree is greater than or equal to a preset threshold, the virtual evaporation pressure is used as the system evaporation pressure.

[0031] In some embodiments of the present application, the determining of the system evaporation pressure by using the internal temperature and inlet temperature of the outdoor heat exchanger and the saturation temperature corresponding to the virtual evaporation pressure includes:

[0032] Calculating the saturation temperature of the system evaporation pressure according to the internal temperature and inlet temperature of the outdoor heat exchanger and the saturation temperature corresponding to the virtual evaporation pressure;

[0033] The system evaporation pressure is obtained according to the saturation temperature of the system evaporation pressure.

[0034] A second aspect of the present invention provides a pressure detection device for an air conditioning system, the device comprising:

[0035] a refrigeration detection module, used to obtain a system evaporation pressure detected by a pressure sensor for controlling a compressor when the air-conditioning system is in a refrigeration mode, and determine a system condensation pressure for controlling an outdoor fan according to the detected system evaporation pressure and a characteristic parameter of the compressor;

[0036] The heating detection module is used to obtain the system condensing pressure detected by the pressure sensor for controlling the compressor when the air-conditioning system is in heating mode, and determine the system evaporating pressure for controlling the outdoor fan according to the detected system condensing pressure and compressor characteristic parameters.

[0037] A third aspect of the present invention provides an air conditioning system, comprising a compressor, an indoor unit and a four-way valve, and also comprising a pressure detection device for the air conditioning system as described in the second aspect;

[0038] A pressure sensor is provided on the connecting pipe between the first end of the four-way valve and one end of the indoor unit, and the pressure sensor is used to detect the system evaporation pressure for controlling the compressor when the air-conditioning system is in cooling mode, and to detect the system condensing pressure for controlling the compressor when the air-conditioning system is in heating mode.

[0039] A fourth aspect of the present invention provides a computer-readable storage medium having a computer program stored thereon, wherein the program, when executed by a processor, implements the steps of the method described in the first aspect above.

[0040] Based on the above-mentioned air conditioning system and its pressure detection method, device and storage medium, the technical solution of the present invention has the following beneficial effects or advantages:

[0041] By setting up a pressure sensor between the four-way valve and the indoor unit, in the cooling mode, the pressure sensor detects the system evaporation pressure, and calculates the system condensation pressure according to the system evaporation pressure and the compressor characteristic parameters to control the outdoor fan. In the heating mode, the pressure sensor detects the system condensation pressure, and calculates the system evaporation pressure according to the system condensation pressure and the compressor characteristic parameters to control the outdoor fan. It can be seen that even if the system condensation pressure in the cooling mode and the system evaporation pressure in the heating mode are obtained by calculating the compressor characteristic parameters instead of the precise value detected by the pressure sensor, the fuzzy control method of the fan can be satisfied. In this way, the air-conditioning system can realize the compressor frequency control and the fan speed control by using only one pressure sensor, which reduces the cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0043] Figure 1 A structural schematic diagram of an air conditioning system shown in the present invention;

[0044] Figure 2 A schematic diagram of a refrigerant circulation in a refrigeration mode of an air-conditioning system shown in the present invention;

[0045] Figure 3A schematic diagram of a refrigerant circulation in a heating mode of an air-conditioning system shown in the present invention;

[0046] Figure 4 This is a schematic flow chart of an embodiment of a method for detecting pressure of an air-conditioning system according to an exemplary embodiment of the present invention;

[0047] Figure 5 It is a structural schematic diagram of a pressure detection device according to an exemplary embodiment of the present invention;

[0048] Figure 6 The figure is a schematic diagram of the structure of a storage medium according to an exemplary embodiment of the present invention.

[0049] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0050] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0051] It should be noted that all directional indications in the embodiments of the present invention (such as up, down, left, right, front, back, etc.) are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0052] In addition, in the present invention, descriptions such as "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0053] In the present invention, unless otherwise clearly specified and limited, the terms "connection", "fixation", etc. should be understood in a broad sense. For example, "fixation" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0054] In addition, the technical solutions between the various embodiments of the present invention can be combined with each other, but it must be based on the fact that ordinary technicians in the field can implement it. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0055] Controlling the frequency of the compressor and the fan speed according to the evaporation pressure and condensation pressure is a common control method for multi-split products. In cooling mode, the operating frequency of the compressor is usually controlled according to the deviation between the actual evaporation pressure and the target evaporation pressure, and the fan speed is controlled according to the deviation between the actual condensation pressure and the target condensation pressure; in heating mode, the operating frequency of the compressor is usually controlled according to the deviation between the actual condensation pressure and the target condensation pressure, and the fan speed is controlled according to the deviation between the actual evaporation pressure and the target evaporation pressure. For this purpose, a pressure sensor needs to be installed on the exhaust pipe and the suction pipe of the compressor to detect the actual evaporation pressure and the actual condensation pressure of the air conditioning system.

[0056] Since controlling the operating frequency of the compressor directly affects the user's comfort experience, it is more accurate to use a pressure sensor to detect the pressure value used to control the compressor (including the evaporation pressure in cooling mode and the condensing pressure in heating mode). However, fan control usually adopts fuzzy control, which does not require very precise system condensing pressure or system evaporation pressure control. Therefore, it is not necessary to use a pressure sensor to monitor the relevant pressure values.

[0057] Based on this, the present application proposes an air-conditioning system that uses only one pressure sensor for pressure monitoring. In cooling mode, the pressure sensor detects the system evaporating pressure, and uses the compressor characteristic parameters and the system evaporating pressure to calculate the system condensing pressure. In heating mode, the pressure sensor detects the system condensing pressure, and uses the compressor characteristic parameters and the system condensing pressure to calculate the system evaporating pressure.

[0058] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application.

[0059] See also Figure 1 As shown, the air conditioning system includes an outdoor unit 10 and an indoor unit 20 connected to the outdoor unit. The outdoor unit 10 includes a compressor 101, an oil-liquid separator 102, a gas-liquid separator 103, a four-way valve 104, a pressure sensor 105, an outdoor heat exchanger 106, and an outdoor fan 107; the indoor unit 20 includes an indoor heat exchanger 201.

[0060] In this embodiment, the compressor 101 includes an intake end and an exhaust end. The intake end of the compressor 101 is connected to the gas-liquid separator 103 , and the exhaust end of the compressor 101 is connected to the oil-liquid separator 102 .

[0061] In this embodiment, the oil-liquid separator 102 is arranged between the compressor 101 and the four-way valve 104. The oil-liquid separator 102 includes an input port, an air outlet and an oil outlet. The input port of the oil-liquid separator 102 is connected to the exhaust end of the compressor 101, the air outlet of the oil-liquid separator 102 is connected to the four-way valve 104, and the oil outlet of the oil-liquid separator 102 is connected to the suction end of the compressor 101.

[0062] In this embodiment, the gas-liquid separator 103 is arranged between the compressor 101 and the four-way valve 104. The gas-liquid separator 103 includes an input port and an output port. The input port of the gas-liquid separator 103 is connected to the four-way valve 104, and the output port of the gas-liquid separator 103 is connected to the suction end of the compressor 101.

[0063] In this embodiment, when the air conditioning system is in cooling mode, the four-way valve 104 is used to connect the exhaust end of the compressor 101 and one end of the outdoor heat exchanger 106, and one end of the indoor heat exchanger 201 and the suction end of the compressor 101. When the air conditioning system is in heating mode, the four-way valve 104 is switched to connect the exhaust end of the compressor 101 and one end of the indoor heat exchanger 201, and one end of the outdoor heat exchanger 106 and the suction end of the compressor 101. The other end of the outdoor heat exchanger 106 is connected to the other end of the indoor heat exchanger 201.

[0064] Furthermore, the four-way valve 104 includes a first port a, a second port b, a third port c and a fourth port d, the first port a is connected to one end of the indoor heat exchanger 201, the second port b is connected to the suction end of the compressor 101, the third port c is connected to one end of the outdoor heat exchanger 106, and the fourth port d is connected to the exhaust end of the compressor 101; when the air-conditioning system is in cooling mode, the first port a in the four-way valve 104 is connected to the second port b, and the third port c is connected to the fourth port d; when the air-conditioning system is in heating mode, the first port a in the four-way valve 104 is connected to the fourth port d, and the second port b is connected to the third port c.

[0065] In this embodiment, the pressure sensor 105 is arranged on the connecting pipe between the four-way valve 104 and one end of the indoor heat exchanger 201. The pressure sensor 105 is used to detect the system evaporation pressure of the air-conditioning system when the air-conditioning system is in cooling mode, that is, the low pressure value, and to detect the system condensing pressure of the air-conditioning system when the air-conditioning system is in heating mode, that is, the high pressure value.

[0066] See also Figure 2As shown, when the air-conditioning system is in cooling mode, the first port a in the four-way valve 104 is connected to the second port b, and the third port c is connected to the fourth port d. The four-way valve 104 is used to connect the exhaust end of the compressor 101 and one end of the outdoor heat exchanger 106 as well as one end of the indoor heat exchanger 201 and the suction end of the compressor 101.

[0067] That is, when the air conditioning system is in cooling mode, the refrigerant starts from the suction end of the compressor 101, passes through the oil-liquid separator 102, the fourth port d of the four-way valve 104, the third port c of the four-way valve 104, the outdoor heat exchanger 106, the indoor heat exchanger 201, the first port a of the four-way valve 104, the second port b of the four-way valve 104, the gas-liquid separator 103, and finally flows back to the compressor 101. In this operation mode, the pressure sensor 105 is used to detect the system evaporation pressure, that is, as a low-pressure sensor to detect the low-pressure value of the air conditioning system.

[0068] See also Figure 3 As shown, when the air-conditioning system is in heating mode, the first port a in the four-way valve 104 is connected to the fourth port d, and the second port b is connected to the third port c. The four-way valve 104 is used to connect the exhaust end of the compressor 101 and one end of the indoor heat exchanger 201 and one end of the outdoor heat exchanger 106 and the suction end of the compressor 101.

[0069] That is, when the air conditioning system is in heating mode, the refrigerant starts from the suction end of the compressor 101, passes through the oil-liquid separator 102, the fourth port d of the four-way valve 104, the first port a of the four-way valve 7, the indoor heat exchanger 201, the outdoor heat exchanger 106, the third port c of the four-way valve 104, the second port b of the four-way valve 104, the gas-liquid separator 103, and finally flows back to the compressor 101. In this operating mode, the pressure sensor 105 is used to detect the system condensing pressure, that is, as a high-pressure sensor to detect the high pressure value of the air conditioning system.

[0070] In this embodiment, the air conditioning system further includes a pressure detection device ( Figure 1 (not shown in the figure), the pressure detection device is electrically connected to the pressure sensor 105, the compressor 101 and the outdoor fan 107. The pressure detection device is used to obtain the system evaporation pressure detected by the pressure sensor 105 when the air-conditioning system is in the cooling mode, so as to accurately control the operating frequency of the compressor 101, and determine the system condensing pressure according to the system evaporation pressure and the compressor characteristic parameters, so as to control the speed of the outdoor fan 107; when the air-conditioning system is in the heating mode, obtain the system condensing pressure detected by the pressure sensor 105, so as to accurately control the operating frequency of the compressor 101, and determine the system evaporation pressure according to the system condensing pressure and the compressor characteristic parameters, so as to control the speed of the outdoor fan 107.

[0071] The technical effects that can be achieved based on the above description are:

[0072] By using only one pressure sensor for pressure monitoring, the system evaporation pressure is detected in cooling mode, and the system condensation pressure is detected in heating mode. In this way, even if the system condensation pressure in cooling mode and the system evaporation pressure in heating mode are obtained by calculating the compressor characteristic parameters instead of the precise values ​​detected by the pressure sensor, the fuzzy control method of the fan can be satisfied. In this way, the air-conditioning system only uses one pressure sensor to achieve compressor frequency control and fan speed control, thereby reducing costs.

[0073] In some embodiments, the air conditioning system may further include electronic components for detecting an input voltage and an input current of the compressor 101 , and the input power of the compressor 101 may be obtained through the input voltage and the input current.

[0074] In addition, the air-conditioning system may further include a temperature sensor for detecting the exhaust temperature of the compressor 101 and a temperature sensor for detecting the intake temperature of the compressor 101, wherein the temperature sensor for detecting the exhaust temperature is arranged on the exhaust pipe of the compressor 101, and the temperature sensor for detecting the intake temperature is arranged on the intake pipe of the compressor 101.

[0075] Furthermore, the input power, suction temperature, and exhaust temperature of the compressor 101 can be regarded as compressor characteristic parameters to participate in the calculation of the system condensing pressure in the cooling mode and the system evaporating pressure in the heating mode.

[0076] In some embodiments, temperature sensors can be set at the inlet of the outdoor heat exchanger 106, the inside of the outdoor heat exchanger 106, and the outlet of the outdoor heat exchanger 106. These temperature sensors are used to detect the inlet temperature of the outdoor heat exchanger 106, the internal temperature of the outdoor heat exchanger 106, and the outlet temperature of the outdoor heat exchanger 106, respectively.

[0077] Figure 4 FIG. 1 is a flow chart of an embodiment of a pressure detection method for an air conditioning system according to an exemplary embodiment of the present invention. The structure of the air conditioning system is shown in FIG. Figure 1-Figure 3 The embodiment shown, as Figure 4 As shown, the pressure detection method comprises the following steps:

[0078] Step 401: when the air conditioning system is in cooling mode, obtaining a system evaporation pressure detected by a pressure sensor for controlling a compressor, and determining a system condensation pressure for controlling an outdoor fan according to the detected system evaporation pressure and a characteristic parameter of the compressor;

[0079] Step 402: When the air conditioning system is in heating mode, the system condensing pressure detected by the pressure sensor for controlling the compressor is obtained, and the system evaporating pressure for controlling the outdoor fan is determined according to the detected system condensing pressure and the compressor characteristic parameters.

[0080] When the air-conditioning system is in cooling mode, the outdoor heat exchanger is used as a condenser and the indoor heat exchanger is used as an evaporator. The system evaporation pressure detected by the pressure sensor can be understood as the compressor suction pressure, that is, the low pressure value.

[0081] For example, the system evaporation pressure in cooling mode may be used to control the operating frequency of the compressor.

[0082] The system condensing pressure obtained from the system evaporating pressure and the compressor characteristic parameters can be understood as the compressor exhaust pressure, that is, the high pressure value.

[0083] For example, the system condensing pressure in cooling mode can be used to control the speed of the outdoor fan.

[0084] Considering that the system condensing pressure in the cooling mode is not an accurate value detected by the pressure sensor, the fuzzy control method can be used to control the speed of the outdoor fan according to the system condensing pressure. For example, the target condensing pressure input by the system is divided into multiple fuzzy subsets, such as "low", "mid-range", and "high". The target condensing pressure currently used belongs to the mid-range fuzzy subset. The system condensing pressure is compared with the mid-range fuzzy subset. If the system condensing pressure is lower than the mid-range fuzzy subset, the outdoor fan speed is reduced. If the system condensing pressure is higher than the mid-range fuzzy subset, the outdoor fan speed is increased.

[0085] When the air-conditioning system is in heating mode, the outdoor heat exchanger is used as an evaporator and the indoor heat exchanger is used as a condenser. The system condensing pressure detected by the pressure sensor can be understood as the compressor exhaust pressure, which is the high pressure value.

[0086] For example, the system condensing pressure in heating mode may be used to control the operating frequency of the compressor.

[0087] The system evaporation pressure obtained from the system condensing pressure and the compressor characteristic parameters can be understood as the compressor suction pressure, that is, the low pressure value.

[0088] For example, the system evaporation pressure in the heating mode can be used to control the speed of the outdoor fan.

[0089] Considering that the system evaporation pressure in the heating mode is not an accurate value detected by the pressure sensor, the fuzzy control method can be used to control the speed of the outdoor fan according to the system evaporation pressure. For example, the target evaporation pressure input by the system is divided into multiple fuzzy subsets, such as "low", "mid-range", and "high". The current target evaporation pressure belongs to the mid-range fuzzy subset. The system evaporation pressure is compared with the mid-range fuzzy subset. If the system evaporation pressure is lower than the mid-range fuzzy subset, the outdoor fan speed is reduced. If the system evaporation pressure is higher than the mid-range fuzzy subset, the outdoor fan speed is increased.

[0090] The compressor characteristic parameter can be understood as a system parameter related to the compressor in the air-conditioning system, which can reflect the pressure of the refrigerant circulating in the pipeline.

[0091] For example, the compressor characteristic parameter may include at least one of an input power of the compressor, a discharge temperature of the compressor, and a suction temperature of the compressor.

[0092] It is worth noting here that the above-mentioned step 401 and step 402 are pressure detection processes under two different working modes of the air-conditioning system, so there is no restriction on the order of the step 401 and step 402.

[0093] At this point, the above Figure 4 The pressure detection process shown in the figure uses only one pressure sensor for pressure monitoring to detect the system evaporation pressure in cooling mode and the system condensation pressure in heating mode. In this way, even if the system condensation pressure in cooling mode and the system evaporation pressure in heating mode are obtained by calculating the compressor characteristic parameters instead of the precise values ​​detected by the pressure sensor, the fuzzy control method of the fan can be satisfied. In this way, the air-conditioning system only uses one pressure sensor to realize compressor frequency control and fan speed control, thereby reducing costs.

[0094] In some embodiments of the present application, determining the system condensing pressure for controlling the outdoor fan according to the detected system evaporation pressure and the compressor characteristic parameter in the above step 401 includes:

[0095] Calculating a virtual condensing pressure using a system evaporation pressure and a compressor characteristic parameter, wherein the compressor characteristic parameter includes at least one of an input power, an exhaust temperature of the compressor, and an intake temperature of the compressor;

[0096] Determine the frequency change degree of the compressor according to the compressor operating frequencies detected twice in succession;

[0097] The system condensing pressure is determined based on the virtual condensing pressure and the frequency change degree.

[0098] The virtual condensing pressure can be understood as the theoretical compressor exhaust pressure determined by the compressor characteristics.

[0099] The compressor operating frequency refers to the actual frequency of the compressor. In cooling mode, this frequency changes dynamically as the deviation between the system evaporating pressure and the target evaporating pressure changes.

[0100] The frequency change degree can be understood as the change rate of the compressor operating frequency between two times. For example, the compressor operating frequency is detected once every 1 minute, and the difference between the compressor operating frequencies detected twice before and after is divided by the compressor operating frequency detected previously to obtain the frequency change degree.

[0101] In this embodiment, the virtual condensing pressure at the theoretical level is calculated by using the system evaporation pressure and the compressor characteristic parameters, and then the final system condensing pressure is obtained by combining the frequency change degree of the compressor and the virtual condensing pressure to improve the accuracy of the system condensing pressure.

[0102] In some embodiments of the present application, the process of calculating the virtual condensing pressure using the system evaporation pressure and the compressor characteristic parameters includes:

[0103] Obtain the saturation temperature corresponding to the system evaporation pressure;

[0104] The virtual condensing pressure is calculated according to the saturation temperature, the compressor characteristic parameters and a preset first fitting relationship.

[0105] The above saturation temperature can be understood as the boiling point temperature of the liquid under a certain evaporation pressure, that is, at this temperature, the refrigerant begins to evaporate rapidly from the liquid to form a gas.

[0106] Usually, for a given substance, there is a definite relationship between the evaporation pressure and the saturation temperature. As the temperature increases, the evaporation pressure will also increase. Conversely, as the temperature decreases, the evaporation pressure will also decrease. This relationship can be described by the saturation pressure curve. Therefore, the saturation temperature at the evaporation pressure of the system can be obtained using a pre-established pressure-temperature diagram or formula.

[0107] The first fitting relationship is a fitting formula for calculating a virtual condensing pressure of the air-conditioning system in the cooling mode.

[0108] Optionally, the first fitting relationship is as follows:

[0109] Pcx=R1×Te^a1×W^b1×TD^c1×TS^d1+R2×Te^a2×W^b2×TD^c2×TS^d2+R3×Te^a3×W^b3×TD^c3×TS^d3+…+Rn×Te^an×W^bn×TD^cn×TS^dn

[0110] Among them, Pcx represents the virtual condensing pressure, R1-Rn, a1-an, b1-bn, c1-cn and d1-dn all represent inherent coefficients, which are determined by the compressor, refrigerant and refrigeration oil, Te represents the saturation temperature of the system evaporation pressure, W represents the input power of the compressor, TD represents the exhaust temperature of the compressor, and TS represents the suction temperature of the compressor.

[0111] It is worth noting that the above is only an exemplary first fitting relationship, but it does not limit the protection scope of the present invention.

[0112] In this embodiment, the virtual condensing pressure at a theoretical level is calculated by substituting the saturation temperature of the system evaporation pressure and the compressor characteristic parameters into a pre-established first fitting relationship.

[0113] In some embodiments of the present application, the process of determining the system condensing pressure according to the virtual condensing pressure and the frequency change degree includes:

[0114] When the frequency variation is less than a preset threshold, the system condensing pressure is determined by using the internal temperature and outlet temperature of the outdoor heat exchanger and the saturation temperature corresponding to the virtual condensing pressure;

[0115] When the frequency variation degree is greater than or equal to a preset threshold, the virtual condensing pressure is used as the system condensing pressure.

[0116] The above-mentioned preset threshold is a frequency change value preset according to practical experience, for example, 10%.

[0117] The internal temperature refers to the refrigerant temperature inside the outdoor heat exchanger. In cooling mode, the outlet temperature refers to the refrigerant temperature when the refrigerant is condensed from gas to liquid inside the outdoor heat exchanger.

[0118] The saturation temperature mentioned above can be understood as the temperature at which the refrigerant gas turns into a liquid at a certain condensing pressure, that is, the temperature at which the gas condenses into a liquid at a specific gas pressure. Generally, as the condensing pressure increases, the condensing temperature will also increase, because higher pressures require higher temperatures to condense the gas into a liquid. Similarly, the saturation temperature corresponding to the system condensing pressure can be obtained using a pre-established pressure-temperature chart or formula.

[0119] In this embodiment, if the frequency change of the compressor is less than the preset threshold value, it means that the frequency change of the compressor is not large. The system condensing pressure can be calculated by combining the temperature of the outdoor heat exchanger (acting as a condenser at this time) in the process of condensing the refrigerant from gas to liquid output and the saturation temperature of the virtual condensing pressure. If the frequency change of the compressor is greater than or equal to the preset threshold value, it means that the frequency change of the compressor is relatively large. At this time, there is no need to consider the temperature parameters of the outdoor heat exchanger, and the virtual condensing pressure can be directly used as the system condensing pressure.

[0120] In some embodiments of the present application, the process of determining the system condensing pressure using the internal temperature and outlet temperature of the outdoor heat exchanger and the saturation temperature corresponding to the virtual condensing pressure includes:

[0121] Calculate the saturation temperature of the system condensing pressure based on the internal temperature and outlet temperature of the outdoor heat exchanger and the saturation temperature corresponding to the virtual condensing pressure;

[0122] The system condensing pressure is obtained according to the saturation temperature of the system condensing pressure.

[0123] The calculation formula for the saturation temperature of the system condensing pressure is as follows:

[0124] Tc=max(max(Tm,To)+D,Tcx)

[0125] Among them, Tc represents the saturation temperature of the system condensing pressure, Tm represents the internal temperature of the outdoor heat exchanger, To represents the outlet temperature of the outdoor heat exchanger, Tcx represents the saturation temperature corresponding to the virtual condensing pressure, and D represents the pressure loss constant.

[0126] The system condensing pressure is obtained according to the saturation temperature of the system condensing pressure. Specifically, the system condensing pressure corresponding to the saturation temperature can be obtained using a pre-established pressure-temperature diagram or formula.

[0127] In some embodiments of the present application, determining the system evaporation pressure for controlling the outdoor fan according to the detected system condensing pressure and the compressor characteristic parameter in the above step 402 includes:

[0128] Calculating the virtual evaporation pressure using the system condensing pressure and the compressor characteristic parameters; the compressor characteristic parameters include at least one of the input power of the compressor, the exhaust temperature of the compressor, and the suction temperature of the compressor;

[0129] Determine the frequency change degree of the compressor according to the compressor operating frequencies detected twice in succession;

[0130] The system evaporation pressure is determined based on the virtual evaporation pressure and the frequency change degree.

[0131] The above-mentioned virtual evaporation pressure can be understood as the theoretical compressor suction pressure determined by the compressor characteristics.

[0132] The compressor operating frequency refers to the actual frequency of the compressor. In heating mode, the frequency changes dynamically as the deviation between the system condensing pressure and the target condensing pressure changes.

[0133] In this embodiment, a virtual evaporation pressure at a theoretical level is calculated by using the system condensing pressure and the compressor characteristic parameters, and then the final system evaporation pressure is obtained by combining the frequency change degree of the compressor and the virtual evaporation pressure to improve the accuracy of the system evaporation pressure.

[0134] In some embodiments of the present application, the process of calculating the virtual evaporation pressure using the system condensing pressure and the compressor characteristic parameter includes:

[0135] Obtain the saturation temperature corresponding to the system condensing pressure;

[0136] The virtual evaporation pressure is calculated according to the saturation temperature, the compressor characteristic parameter and a preset second fitting relationship.

[0137] The saturation temperature corresponding to the system condensing pressure can be understood as the temperature at which the refrigerant gas turns into liquid at a certain condensing pressure, that is, the temperature at which the gas condenses into liquid at a specific gas pressure. Similarly, the saturation temperature corresponding to the system condensing pressure can be obtained using a pre-established pressure-temperature chart or formula.

[0138] The second fitting relational expression is a fitting formula for calculating the virtual evaporation pressure of the air-conditioning system in the heating mode.

[0139] Optionally, the second fitting relationship is as follows:

[0140] Pex=S1×Tc^e1×W^f1×TD^g1×TS^h1+S2×Tc^e2×W^f2×TD^g2×TS^h2+S3×Tc^e3×W^f3×TD^g3×TS^h3+…+Sn×Tc^en×W^fn×TD^gn×TS^hn

[0141] Among them, Pex represents the virtual evaporation pressure, S1-Sn, e1-en, f1-fn, g1-gn and h1-hn all represent inherent coefficients, which are determined by the compressor, refrigerant and refrigeration oil, Tc represents the saturation temperature of the system condensing pressure, W represents the input power of the compressor, TD represents the exhaust temperature of the compressor, and TS represents the suction temperature of the compressor.

[0142] It is worth noting that the above is only an exemplary second fitting relationship, but it does not limit the protection scope of the present invention.

[0143] In this embodiment, the virtual evaporation pressure at the theoretical level is calculated by substituting the saturation temperature of the system condensation pressure and the compressor characteristic parameters into a pre-established second fitting relationship.

[0144] In some embodiments of the present application, the process of determining the system evaporation pressure according to the virtual evaporation pressure and the frequency change degree includes:

[0145] When the frequency variation is less than a preset threshold, the system evaporation pressure is determined by using the internal temperature and inlet temperature of the outdoor heat exchanger and the saturation temperature corresponding to the virtual evaporation pressure;

[0146] When the frequency variation degree is greater than or equal to a preset threshold, the virtual evaporation pressure is used as the system evaporation pressure.

[0147] The preset threshold is a frequency change value preset based on practical experience, such as 10%.

[0148] The internal temperature refers to the refrigerant temperature inside the outdoor heat exchanger. In heating mode, the inlet temperature refers to the refrigerant temperature when the refrigerant evaporates from liquid to gas inside the outdoor heat exchanger.

[0149] The saturation temperature can be understood as the boiling point temperature of the liquid under a certain evaporation pressure, that is, at this temperature, the refrigerant begins to evaporate rapidly from the liquid to form a gas. Similarly, the saturation temperature corresponding to the virtual evaporation pressure can be obtained using a pre-established pressure-temperature diagram or formula.

[0150] In this embodiment, if the frequency change degree of the compressor is less than the preset threshold value, it means that the frequency change of the compressor is not large. The system evaporation pressure can be calculated by combining the temperature of the outdoor heat exchanger (acting as an evaporator at this time) during the process of evaporating the refrigerant from liquid to gas and the saturation temperature of the virtual evaporation pressure. If the frequency change degree of the compressor is greater than or equal to the preset threshold value, it means that the frequency change of the compressor is relatively large. At this time, there is no need to consider the temperature parameters of the outdoor heat exchanger, and the virtual evaporation pressure can be directly used as the system evaporation pressure.

[0151] In some embodiments of the present application, the process of determining the system evaporation pressure using the internal temperature and inlet temperature of the outdoor heat exchanger and the saturation temperature corresponding to the virtual evaporation pressure includes:

[0152] Calculate the saturation temperature of the system evaporation pressure based on the internal temperature and inlet temperature of the outdoor heat exchanger and the saturation temperature corresponding to the virtual evaporation pressure;

[0153] The system evaporation pressure is obtained according to the saturation temperature of the system evaporation pressure.

[0154] The calculation formula of the saturation temperature of the system evaporation pressure is as follows:

[0155] Te=min(min(Tm,Ti)+D,Tex)

[0156] Among them, Te represents the saturation temperature of the system evaporation pressure, Tm represents the internal temperature of the outdoor heat exchanger, Ti represents the inlet temperature of the outdoor heat exchanger, Tex represents the saturation temperature corresponding to the virtual evaporation pressure, and D represents the pressure loss constant.

[0157] The system evaporation pressure is obtained according to the saturation temperature of the system evaporation pressure. Specifically, the system evaporation pressure corresponding to the saturation temperature can be obtained using a pre-established pressure-temperature diagram or formula.

[0158] An embodiment of the present invention further provides a pressure detection device corresponding to the pressure detection method provided in the aforementioned embodiment, so as to execute the aforementioned pressure detection method.

[0159] Figure 5 FIG. 1 is a schematic diagram of a pressure detection device for an air conditioning system according to an exemplary embodiment of the present invention. The device is used to execute the pressure detection method provided in any of the above embodiments. Figure 5 As shown, the pressure detection device comprises:

[0160] A cooling detection module 510 is used to obtain a system evaporation pressure for controlling a compressor detected by a pressure sensor when the air-conditioning system is in a cooling mode, and determine a system condensation pressure for controlling an outdoor fan according to the detected system evaporation pressure and a characteristic parameter of the compressor;

[0161] The heating detection module 520 is used to obtain the system condensing pressure detected by the pressure sensor for controlling the compressor when the air-conditioning system is in the heating mode, and determine the system evaporating pressure for controlling the outdoor fan according to the detected system condensing pressure and the compressor characteristic parameters.

[0162] The implementation process of the functions and effects of each unit in the above-mentioned device is specifically described in the implementation process of the corresponding steps in the above-mentioned method, and will not be repeated here.

[0163] For the device embodiment, since it basically corresponds to the method embodiment, the relevant parts can refer to the partial description of the method embodiment. The device embodiment described above is only schematic, wherein the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the present application scheme. A person of ordinary skill in the art can understand and implement it without paying any creative work.

[0164] The pressure detection device provided in the embodiment of the present application and the pressure detection method provided in the embodiment of the present application are based on the same inventive concept and have the same beneficial effects as the methods adopted, operated or implemented therein.

[0165] The present application also provides a computer-readable storage medium corresponding to the pressure detection method provided in the above embodiment. Figure 6 As shown, the computer-readable storage medium shown is a CD 30 on which a computer program (ie, a program product) is stored. When the computer program is run by a processor, the pressure detection method provided by any of the aforementioned embodiments will be executed.

[0166] It should be noted that examples of the computer-readable storage medium may also 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 optical or magnetic storage media, which are not listed here one by one.

[0167] The computer-readable storage medium provided in the above-mentioned embodiments of the present application and the pressure detection method provided in the embodiments of the present application are based on the same inventive concept and have the same beneficial effects as the methods adopted, run or implemented by the application programs stored therein.

[0168] Those skilled in the art will readily appreciate other embodiments of the present invention after considering the specification and practicing the invention disclosed herein. The present invention is intended to cover any variations, uses or adaptations of the present invention that follow the general principles of the present invention and include common knowledge or customary techniques in the art not disclosed by the present invention. The description and examples are to be regarded as exemplary only, and the true scope and spirit of the present invention is indicated by the following claims.

[0169] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A pressure detection method for an air conditioning system, characterized in that: The method comprises: When the air-conditioning system is in cooling mode, obtaining a system evaporation pressure detected by a pressure sensor for controlling a compressor, and determining a system condensation pressure for controlling an outdoor fan according to the detected system evaporation pressure and a characteristic parameter of the compressor; When the air-conditioning system is in heating mode, the system condensing pressure detected by the pressure sensor for controlling the compressor is obtained, and the system evaporating pressure for controlling the outdoor fan is determined according to the detected system condensing pressure and the compressor characteristic parameters.

2. The method according to claim 1, characterized in that The method of determining the system condensing pressure for controlling the outdoor fan according to the detected system evaporation pressure and the compressor characteristic parameter comprises: Calculating a virtual condensing pressure using the system evaporation pressure and the compressor characteristic parameter; the compressor characteristic parameter includes at least one of the input power of the compressor, the exhaust temperature of the compressor, and the suction temperature of the compressor; Determining a frequency change degree of the compressor according to two consecutive detected compressor operating frequencies; The system condensing pressure is determined according to the virtual condensing pressure and the frequency change degree.

3. The method according to claim 2, characterized in that The calculating of the virtual condensing pressure by using the system evaporation pressure and the compressor characteristic parameter comprises: Obtaining a saturation temperature corresponding to the evaporation pressure of the system; The virtual condensing pressure is calculated according to the saturation temperature, the compressor characteristic parameter and a preset first fitting relationship; the first fitting relationship is used to calculate the virtual condensing pressure of the air-conditioning system in the cooling mode.

4. The method according to claim 2, characterized in that The determining the system condensing pressure according to the virtual condensing pressure and the frequency change degree includes: When the frequency variation degree is less than a preset threshold, the system condensing pressure is determined by using the internal temperature and outlet temperature of the outdoor heat exchanger and the saturation temperature corresponding to the virtual condensing pressure; When the frequency change degree is greater than or equal to a preset threshold, the virtual condensing pressure is used as the system condensing pressure.

5. The method according to claim 4, characterized in that The method of determining the system condensing pressure by using the internal temperature and outlet temperature of the outdoor heat exchanger and the saturation temperature corresponding to the virtual condensing pressure includes: Calculating the saturation temperature of the system condensing pressure according to the internal temperature and outlet temperature of the outdoor heat exchanger and the saturation temperature corresponding to the virtual condensing pressure; The system condensing pressure is obtained according to the saturation temperature of the system condensing pressure.

6. The method according to claim 1, characterized in that The method of determining the system evaporation pressure for controlling the outdoor fan according to the detected system condensation pressure and the compressor characteristic parameter comprises: Calculating a virtual evaporation pressure using the system condensing pressure and the compressor characteristic parameter; the compressor characteristic parameter includes at least one of the input power of the compressor, the exhaust temperature of the compressor, and the suction temperature of the compressor; Determining a frequency change degree of the compressor according to two consecutive detected compressor operating frequencies; The system evaporation pressure is determined according to the virtual evaporation pressure and the frequency change degree.

7. The method according to claim 6, characterized in that The calculating of the virtual evaporation pressure by using the system condensing pressure and the compressor characteristic parameter comprises: Obtaining a saturation temperature corresponding to the condensing pressure of the system; The virtual evaporation pressure is calculated according to the saturation temperature, the compressor characteristic parameter and a preset second fitting relationship; the second fitting relationship is used to calculate the virtual evaporation pressure of the air-conditioning system in the heating mode.

8. The method according to claim 6, characterized in that The determining of the system evaporation pressure according to the virtual evaporation pressure and the frequency change degree includes: When the frequency variation degree is less than a preset threshold, the system evaporation pressure is determined by using the internal temperature and inlet temperature of the outdoor heat exchanger and the saturation temperature corresponding to the virtual evaporation pressure; When the frequency variation degree is greater than or equal to a preset threshold, the virtual evaporation pressure is used as the system evaporation pressure.

9. The method according to claim 8, characterized in that The method of determining the system evaporation pressure by using the internal temperature and inlet temperature of the outdoor heat exchanger and the saturation temperature corresponding to the virtual evaporation pressure includes: Calculating the saturation temperature of the system evaporation pressure according to the internal temperature and inlet temperature of the outdoor heat exchanger and the saturation temperature corresponding to the virtual evaporation pressure; The system evaporation pressure is obtained according to the saturation temperature of the system evaporation pressure.

10. A pressure detection device for an air conditioning system, characterized in that: The device comprises: a refrigeration detection module, used to obtain a system evaporation pressure detected by a pressure sensor for controlling a compressor when the air-conditioning system is in a refrigeration mode, and determine a system condensation pressure for controlling an outdoor fan according to the detected system evaporation pressure and a characteristic parameter of the compressor; The heating detection module is used to obtain the system condensing pressure detected by the pressure sensor for controlling the compressor when the air-conditioning system is in heating mode, and determine the system evaporating pressure for controlling the outdoor fan according to the detected system condensing pressure and compressor characteristic parameters.

11. An air conditioning system, comprising a compressor, an indoor unit and a four-way valve, characterized in that: Also includes the pressure detection device of the air conditioning system as claimed in claim 10; A pressure sensor is provided on the connecting pipe between the first end of the four-way valve and one end of the indoor unit, and the pressure sensor is used to detect the system evaporation pressure when the air-conditioning system is in cooling mode, and to detect the system condensation pressure when the air-conditioning system is in heating mode.

12. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the program is executed by a processor, the steps of the method according to any one of claims 1 to 9 are implemented.

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