Air conditioning systems and their control methods, devices, storage media and program products

Abstract

This invention provides an air conditioning system and its control method, device, storage medium, and program product. The air conditioning system includes: a compressor, a first heat exchanger, a second heat exchanger, a third heat exchanger, a first throttling device, a second throttling device, a third throttling device, a first four-way reversing valve, a second four-way reversing valve, and a flash evaporator. The control method includes: during operation of the air conditioning system, determining whether the temperature difference between the indoor ambient temperature and the set temperature is greater than or equal to a preset temperature difference threshold; if the temperature difference is less than the preset temperature difference threshold, determining the predicted noise of the third throttling device based on the mid-flow temperatures of the second and third heat exchangers; and adjusting the opening degrees of the first and second throttling devices, or adjusting the outdoor fan speed and the opening degree of the second throttling device, based on the predicted noise. The solution provided by this invention can reduce the flow noise of the electronic expansion valve while maintaining energy efficiency.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of control, and in particular to an air conditioning system and a control method, device, storage medium and program product thereof. BACKGROUND

[0002] In the related art, the indoor unit side of the three-control dual-temperature parallel compression system uses an electronic expansion valve to control the dual-temperature evaporation temperature difference and the refrigerant flow distribution. Since the refrigerant before the valve is in a two-phase state, two-phase flow noise is generated, which affects the user comfort. SUMMARY

[0003] The main purpose of the present application is to overcome the defects of the above-mentioned related art, and to provide an air conditioning system and a control method, device, storage medium and program product thereof, to solve the problem of flow noise of the throttling device on the indoor unit side of the multiple electronic expansion valve system in the related art.

[0004] In one aspect, the present application provides a control method of an air conditioning system, the air conditioning system comprising: a compressor, a first heat exchanger, a second heat exchanger, a third heat exchanger, a first throttling device, a second throttling device, a third throttling device, a first four-way reversing valve, a second four-way reversing valve and a flash tank, the gas outlet end of the flash tank being connected to the gas supplement end of the compressor, the inlet end of the flash tank being connected to the first heat exchanger, the first throttling device being arranged on the pipeline between the flash tank and the first heat exchanger, the second heat exchanger and the third heat exchanger being connected to the flash tank through the second throttling device after being connected in parallel, and the third throttling device being arranged on the pipeline in which the third heat exchanger and the second heat exchanger are connected in parallel; the control method comprising: when the air conditioning system is in refrigeration operation, determining whether the temperature difference between the indoor environment temperature and the set temperature is greater than or equal to a preset temperature difference threshold; if it is determined that the temperature difference is less than the preset temperature difference threshold, determining the predicted noise of the third throttling device according to the second heat exchanger flow path middle temperature and the third heat exchanger flow path middle temperature; and adjusting the opening degree of the first throttling device and the second throttling device, or adjusting the opening degree of the second throttling device and the rotation speed of the outdoor fan of the air conditioning system, according to the predicted noise.

[0005] Optionally, determining the predicted noise of the third throttling device according to the second heat exchanger flow path middle temperature and the third heat exchanger flow path middle temperature comprises: calculating the maximum mass flow rate in the third throttling device according to the second heat exchanger flow path middle temperature and the third heat exchanger flow path middle temperature; calculating the third throttling device inlet dryness according to the second heat exchanger flow path middle temperature; and calculating the predicted noise of the third throttling device according to the maximum mass flow rate in the third throttling device and the third throttling device inlet dryness.

[0006] Optionally, calculating the maximum mass flow rate in the third throttling device according to the second heat exchanger flow path middle temperature and the third heat exchanger flow path middle temperature comprises: calculating the front and back pressure difference of the third throttling device and the third throttling device inlet saturated liquid density according to the second heat exchanger flow path middle temperature and the third heat exchanger flow path middle temperature; calculating the maximum mass flow rate in the third throttling device according to the front and back pressure difference of the third throttling device and the third throttling device inlet saturated liquid density; and / or calculating the third throttling device inlet dryness according to the second heat exchanger flow path middle temperature comprises: calculating the second heat exchanger saturated liquid enthalpy and the second heat exchanger phase change latent heat according to the second heat exchanger flow path middle temperature; calculating the third throttling device inlet dryness according to the second heat exchanger saturated liquid enthalpy and the second heat exchanger phase change latent heat.

[0007] Optionally, adjusting the opening degree of the first throttling device and the second throttling device according to the predicted noise comprises: judging whether the predicted noise of the third throttling device is greater than or equal to a preset threshold; if it is judged that the predicted noise is greater than or equal to the preset threshold, controlling the opening degree of the first throttling device to decrease and controlling the opening degree of the second throttling device to increase.

[0008] Optionally, it further comprises: after controlling the opening degree of the first throttling device to decrease and controlling the opening degree of the second throttling device to increase, when the opening degree of the first throttling device is less than or equal to a first preset opening degree threshold, or the opening degree of the second throttling device is greater than or equal to a second preset opening degree threshold, keeping the current opening degree of the first throttling device and the second throttling device.

[0009] Optionally, adjusting the opening degree of the first throttling device and the second throttling device according to the predicted noise comprises: judging whether the predicted noise of the third throttling device is greater than or equal to a preset threshold; if it is judged that the predicted noise is greater than or equal to the preset threshold, controlling the opening degree of the first throttling device to decrease and controlling the opening degree of the second throttling device to increase.

[0010] Optionally, it further comprises: after controlling the opening degree of the first throttling device to decrease and controlling the opening degree of the second throttling device to increase, when the opening degree of the first throttling device is less than or equal to a first preset opening degree threshold, or the opening degree of the second throttling device is greater than or equal to a second preset opening degree threshold, keeping the current opening degree of the first throttling device and the second throttling device.

[0011] Another aspect of the present application provides a control device of an air conditioning system, the air conditioning system comprising: a compressor, a first heat exchanger, a second heat exchanger, a third heat exchanger, a first throttling device, a second throttling device, a third throttling device, a first four-way reversing valve, a second four-way reversing valve and a flash tank, a gas outlet end of the flash tank being connected to a gas supplement end of the compressor, an inlet end of the flash tank being connected to the first heat exchanger, the first throttling device being arranged on a pipeline between the flash tank and the first heat exchanger, the second heat exchanger and the third heat exchanger being connected to the flash tank through the second throttling device after being connected in parallel, the third throttling device being arranged on a pipeline between the third heat exchanger and the second heat exchanger connected in parallel; the control device comprising: a judging unit configured to judge whether a temperature difference between an indoor environment temperature and a set temperature is greater than or equal to a preset temperature difference threshold when the air conditioning system is in a refrigeration operation; a determining unit configured to determine a predicted noise of the third throttling device according to a second heat exchanger flow path middle temperature and a third heat exchanger flow path middle temperature if the judging unit judges that the temperature difference is less than the preset temperature difference threshold; and an adjusting unit configured to adjust an opening degree of the first throttling device and the second throttling device or adjust an external fan rotating speed of the air conditioning system and the opening degree of the second throttling device according to the predicted noise determined by the determining unit.

[0012] Optionally, the determining unit determines the predicted noise of the third throttling device according to the second heat exchanger flow path middle temperature and the third heat exchanger flow path middle temperature, comprising: calculating a maximum mass flow rate in the third throttling device according to the second heat exchanger flow path middle temperature and the third heat exchanger flow path middle temperature; calculating an inlet dryness of the third throttling device according to the second heat exchanger flow path middle temperature; and calculating the predicted noise of the third throttling device according to the maximum mass flow rate in the third throttling device and the inlet dryness of the third throttling device.

[0013] Optionally, the determining unit calculates the maximum mass flow rate in the third throttling device according to the second heat exchanger flow path middle temperature and the third heat exchanger flow path middle temperature, comprising: calculating a pressure difference before and after the third throttling device and an inlet saturated liquid density of the third throttling device according to the second heat exchanger flow path middle temperature and the third heat exchanger flow path middle temperature; and calculating the maximum mass flow rate in the third throttling device according to the pressure difference before and after the third throttling device and the inlet saturated liquid density of the third throttling device; and / or, the determining unit calculates the inlet dryness of the third throttling device according to the second heat exchanger flow path middle temperature, comprising: calculating a saturated liquid enthalpy of the second heat exchanger and a phase change latent heat of the second heat exchanger according to the second heat exchanger flow path middle temperature; and calculating the inlet dryness of the third throttling device according to the saturated liquid enthalpy of the second heat exchanger and the phase change latent heat of the second heat exchanger.

[0014] Optionally, the adjusting unit adjusts the opening degree of the first throttling device and the second throttling device according to the predicted noise, including: judging whether the predicted noise of the third throttling device is greater than or equal to a preset threshold; if judging that the predicted noise is greater than or equal to the preset threshold, controlling the opening degree of the first throttling device to decrease and the opening degree of the second throttling device to increase.

[0015] Optionally, the adjusting unit further adjusts the opening degree of the first throttling device and the second throttling device according to the predicted noise, including: judging whether the predicted noise of the third throttling device is greater than or equal to a preset threshold; if judging that the predicted noise is greater than or equal to the preset threshold, controlling the opening degree of the first throttling device to decrease and the opening degree of the second throttling device to increase.

[0016] Optionally, the adjusting unit adjusts the opening degree of the first throttling device and the second throttling device according to the predicted noise, including: judging whether the predicted noise of the third throttling device is greater than or equal to a preset threshold; if judging that the predicted noise is greater than or equal to the preset threshold, controlling the opening degree of the first throttling device to decrease and the opening degree of the second throttling device to increase.

[0017] Optionally, the adjusting unit further adjusts the opening degree of the first throttling device and the second throttling device according to the predicted noise, including: judging whether the predicted noise of the third throttling device is greater than or equal to a preset threshold; if judging that the predicted noise is greater than or equal to the preset threshold, controlling the opening degree of the first throttling device to decrease and the opening degree of the second throttling device to increase.

[0018] In still another aspect, the present application provides a storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of any of the foregoing methods.

[0019] In still another aspect, the present application provides an air conditioning system, comprising a processor, a memory, and a computer program stored in the memory and executable on the processor, wherein the processor implements the steps of any of the foregoing methods when executing the program.

[0020] In still another aspect, the present application provides an air conditioning system, comprising the control device of any of the foregoing.

[0021] In still another aspect, the present application provides a computer program product, comprising a computer program, which, when executed by a processor, implements the steps of any of the foregoing methods.

[0022] According to the technical scheme of the present application, the flow noise of the electronic expansion valve on the indoor unit side of the air conditioning system can be reduced while the capacity and energy efficiency are taken into account, and the indoor comfort is improved.

[0023] According to the technical scheme of the present application, the potential relationship between the system state parameters and the refrigerant property parameters is empirically fitted, the maximum mass flow rate in the electronic expansion valve of the indoor unit and the inlet dryness are accurately calculated, the predicted noise of the electronic expansion valve on the indoor unit side is calculated, and then the noise of the electronic expansion valve on the indoor unit side is reduced by controlling the opening degree of the throttling device on the outdoor unit side or the rotation speed of the outdoor fan.

[0024] According to the technical scheme of the present application, the total noise value of the electronic expansion valve and the main influence parameters, i.e., the maximum mass flow rate in the valve and the inlet dryness, are associated. When the fitted predicted noise value is higher than a certain set value, it is considered that the flow noise is too high, and the noise is reduced by adjusting the system parameters to reduce the inlet dryness of the electronic expansion valve. BRIEF DESCRIPTION OF DRAWINGS

[0025] The drawings described herein are used to provide further understanding of the present application, and form a part of the present application. The illustrative embodiments of the present application and their descriptions serve to explain the present application, and do not constitute improper limitations on the present application. In the drawings:

[0026] Figure 1 is a method schematic diagram of an embodiment of the control method of the air conditioning system provided by the present application;

[0027] Figure 2 is a schematic diagram of the refrigeration operation mode of the air conditioning system provided by the present application;

[0028] Figure 3 shows a flow schematic diagram of one specific embodiment of the step of determining the predicted noise of the third throttling device according to the temperature of the middle part of the second heat exchanger and the temperature of the middle part of the third heat exchanger;

[0029] Figure 4 is a method schematic diagram of one specific embodiment of the control method of the air conditioning system provided by the present application;

[0030] Figure 5 is a method schematic diagram of another specific embodiment of the control method of the air conditioning system provided by the present application;

[0031] Figure 6 is a structure block diagram of one embodiment of the control device of the air conditioning system provided by the present application;

[0032] The reference signs are as follows:

[0033] 1. compressor; 1a, compressor parallel charge cylinder; 1b, compressor first main cylinder; 1c, compressor second main cylinder; 2, first four-way valve; 3, second four-way valve; 4, first heat exchanger; 5, first throttling device; 6, flasher; 7, second throttling device; 8, third throttling device; 9, second heat exchanger; 10, third heat exchanger. DETAILED DESCRIPTION

[0034] In order to make the objects, technical solutions and advantages of the present application clearer, the technical solutions of the present application will be described below in connection with specific embodiments of the present application and corresponding drawings. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present application.

[0035] It should be noted that the terms "first", "second" and the like in the description and claims of the present application and the above drawings are used to distinguish similar objects, and do not necessarily indicate a specific order or sequence. It should be understood that the data thus used can be interchanged under appropriate circumstances, so that the embodiments of the present application described herein can be implemented in an order other than that illustrated or described herein. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion, for example, a process, method, system, product or device that includes a series of steps or units does not have to be limited to those steps or units clearly listed, but can include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0036] When the three-control double-temperature parallel compression system is in refrigeration operation, the inlet side of the indoor electronic expansion valve is in a two-phase state, and the two-phase refrigerant flowing through the electronic expansion valve will produce different degrees of flow noise problems. Since the valve is on the indoor side, when the noise is too large, it will affect the indoor comfort.

[0037] The present application provides a control method and control device of an air conditioning system. The air conditioning system can be a heat pump air conditioning system.

[0038] The air conditioning system comprises a compressor, a first heat exchanger, a second heat exchanger, a third heat exchanger, a first throttling device, a second throttling device, a third throttling device, a first four-way reversing valve, a second four-way reversing valve and a flasher, the gas outlet end of the flasher is connected with the gas supplement end of the compressor, the inlet end of the flasher is connected with the first heat exchanger, the first throttling device is arranged on the pipeline between the flasher and the first heat exchanger, the second heat exchanger and the third heat exchanger are connected to the flasher through the second throttling device, and the third throttling device is arranged on the pipeline in parallel connection between the indoor second heat exchanger and the indoor first heat exchanger. The first heat exchanger is an outdoor heat exchanger, and the second heat exchanger and the third heat exchanger are indoor heat exchangers.

[0039] Figure 2 The air conditioning system provided by the application provides an air conditioning system refrigeration operation mode schematic diagram.

[0040] As Figure 2 shown, the air conditioning system comprises the compressor 1, the first heat exchanger 4, the first throttling device (preferably a first electronic expansion valve) 5, the flasher 6, the second throttling device (preferably a second electronic expansion valve) 7 and an indoor heat exchanger, the flasher 6 is connected between the first throttling device 5 and the second throttling device 7, the inlet end of the flasher is connected with the first heat exchanger 4, the gas outlet end of the flasher 6 is connected with the gas supplement end of the compressor, one end of the first heat exchanger 4 is connected with the first throttling device (preferably a first electronic expansion valve) 5, the other end is connected with the gas discharge end or the gas suction end of the compressor, and the indoor heat exchanger is connected between the second throttling device (preferably a second electronic expansion valve) 7 and the gas discharge end or the gas suction end of the compressor.

[0041] The compressor 1 is a three-cylinder parallel compressor. The three-cylinder parallel compressor 1 comprises a compressor parallel gas supplement cylinder 1a, a compressor first main cylinder 1b and a compressor second main cylinder 1c. The compressor parallel gas supplement cylinder 1a, the compressor first main cylinder 1b and the compressor second main cylinder 1c. The gas suction end of the compressor parallel gas supplement cylinder 1a is a gas supplement end and is in communication with the gas outlet end of the flasher 6, and the gas discharge ends of the compressor first main cylinder 1b, the compressor second main cylinder 1c and the compressor parallel gas supplement cylinder 1a are in communication.

[0042] The indoor heat exchanger comprises a second heat exchanger 9 and a third heat exchanger 10, the second heat exchanger 9 is in communication with the second main cylinder 1c of the compressor, the third heat exchanger 10 is in communication with the first main cylinder 1b of the compressor, one end of the third heat exchanger 10 is in communication with the pipeline where the second heat exchanger 9 is located after being in communication with the third throttling device (preferably a third electronic expansion valve) 8, and the pipeline after being merged is in communication with the second throttling device (preferably a second electronic expansion valve) 7.

[0043] The air conditioning system further comprises a first four-way valve 2 and a second four-way valve 3, the D end of the first four-way valve 2 is in communication with the exhaust end of the compressor 1, the E end is in communication with the second heat exchanger 9, the S end is in communication with the second main cylinder 1c of the compressor, and the C end is in communication with the first heat exchanger 4, the D end of the second four-way valve 3 is in communication with the exhaust end of the compressor 1, the E end is in communication with the third heat exchanger 10, the S end is in communication with the first main cylinder 1b of the compressor, and the C end is in communication with the first heat exchanger 4.

[0044] The air conditioning system comprises a first refrigerant circuit, a second refrigerant circuit and a third refrigerant circuit. The first refrigerant circuit is composed of the first main cylinder 1b of the compressor, the first four-way valve 2, the first heat exchanger 4, the first throttling device 5, the flash evaporator 6, the second throttling device 7, the second heat exchanger 9 and the auxiliary pipeline system; the second refrigerant circuit is composed of the second main cylinder 1c of the compressor, the second four-way valve 3, the first heat exchanger 4, the first throttling device 5, the flash evaporator 6, the second throttling device 7, the third throttling device 8, the third heat exchanger 10 and the auxiliary pipeline system; and the third refrigerant circuit is composed of the parallel air charging cylinder 1a of the compressor, the first four-way valve 2, the first heat exchanger 4, the first throttling device 5, the flash evaporator 6 and the auxiliary pipeline system.

[0045] The system operates as follows: the slide valves of the first four-way valve 2 and the second four-way valve 3 move to the left, connecting terminals E and S, and terminals D and C. The first throttling device 5, the second throttling device 7, and the third throttling device 8 open and are controlled according to logic. The high-temperature, high-pressure refrigerant gas discharged from the first main cylinder 1b of the compressor mixes with the high-temperature, high-pressure refrigerant gas discharged from the second main cylinder 1c and the parallel supplementary cylinder 1a of the compressor, then splits and passes through the first four-way valve 2 and the second four-way valve 3 respectively. After merging again, the gas enters the first heat exchanger 4. After the refrigerant is cooled and condensed, it is throttled to an intermediate pressure state by the first throttling device 5 and enters the flash evaporator 6, where gas-liquid separation occurs. The refrigerant consists of saturated or nearly saturated gas and liquid. The saturated / nearly saturated gas enters the compressor's parallel gas-replenishing cylinder 1a from the gas-replenishing branch to complete the third refrigerant cycle. The saturated or nearly saturated liquid is divided into two paths after passing through the second throttling device 7. One path enters the second heat exchanger 9, where it absorbs heat from the indoor air and evaporates. Then, it passes through the first four-way valve 2 and enters the compressor's second main cylinder 1c to complete the first refrigerant cycle. The other path passes through the third throttling device 8 and enters the third heat exchanger 10, where it absorbs heat from the indoor air and evaporates. Then, it passes through the second four-way valve 3 and enters the compressor's first main cylinder 1b to complete the second refrigerant cycle.

[0046] In view of the above-mentioned three-pipe dual-temperature parallel compression system and similar multi-throttling device (electronic expansion valve) system, this invention proposes a control method and control device for an air conditioning system.

[0047] Figure 1 This is a schematic diagram of an embodiment of the control method for an air conditioning system provided by the present invention.

[0048] like Figure 1 As shown, according to an embodiment of the present invention, the control method of the air conditioning system includes at least steps S110, S120 and S130.

[0049] Step S110: When the air conditioning system is running in cooling mode, determine whether the temperature difference between the indoor ambient temperature and the set temperature is greater than or equal to a preset temperature difference threshold.

[0050] After the air conditioning system is turned on for heating, the compressor frequency, outdoor fan speed, and / or indoor fan speed of the air conditioning system are determined based on the outdoor ambient temperature, indoor ambient temperature, and indoor set temperature. The initial opening degrees of the first, second, and third throttling devices are also determined. The operation of the air conditioning system is controlled based on the determined compressor frequency, outdoor fan speed, and / or indoor fan speed, and the determined initial opening degrees of the first, second, and third throttling devices. During the operation of the air conditioning system, the opening degrees of the first, second, and third throttling devices can also be adjusted according to the operating parameters of the air conditioning system.

[0051] The compressor frequency, the outdoor fan speed and / or the indoor fan speed of the air conditioning system are determined according to the outdoor environment temperature, the indoor environment temperature and the set temperature according to the pre-set value in the starting stage. If the current running mode of the air conditioner is the cooling mode, the initial opening degrees of the first throttling device, the second throttling device and the third throttling device are determined according to the compressor frequency, the indoor environment temperature and the outdoor environment temperature, wherein the initial opening degrees of the first throttling device, the second throttling device and the third throttling device corresponding to different compressor frequencies, indoor environment temperatures and outdoor environment temperatures can be determined by experiments in advance.

[0052] The first throttling device, the second throttling device and the third throttling device can be electronic expansion valves. When the air conditioner receives the starting instruction, the compressor frequency, the outdoor fan speed and / or the indoor fan speed are operated according to the pre-set value in the starting stage according to the indoor and outdoor environment temperatures detected by the temperature sensing bags and the user set temperature, and the opening degrees of the outdoor electronic expansion valves (the first and second electronic expansion valves) and the indoor electronic expansion valve (the third electronic expansion valve) are calculated according to the detected temperatures.

[0053] Preferably, after the air conditioning system is started and operated for a pre-set time, it is judged whether the temperature difference between the indoor environment temperature and the set temperature is greater than or equal to a pre-set temperature difference threshold. Specifically, after the air conditioning system is started and operated for a first pre-set time T1, it is judged whether the temperature difference between the indoor environment temperature t 内环 and the set temperature t 设 is greater than or equal to a pre-set temperature difference threshold a, i.e. whether t 内环 -t 设 ≥ a. The first pre-set time T1 has a value range of 2-10 minutes. The pre-set temperature difference threshold a has a value range of 0-5℃, and is preferably 2℃. The indoor environment temperature t 内环 can be collected by the environment temperature sensing bag arranged in the indoor unit of the air conditioner; and the set temperature t 设 can be set by the user.

[0054] In step S120, if it is judged that the temperature difference is less than the pre-set temperature difference threshold, the predicted noise of the third throttling device is determined according to the middle part temperature of the second heat exchanger flow path and the middle part temperature of the third heat exchanger flow path.

[0055] That is, if t 内环 -t 设 ≥ a is not satisfied, the predicted noise of the third throttling device is determined according to the middle part temperature of the second heat exchanger flow path and the middle part temperature of the third heat exchanger flow path. The middle part temperatures t e_h and t e_lThe temperature can be collected by temperature sensors located in the middle of the flow paths of the second and third heat exchangers, respectively; exhaust temperature t dis Temperature can be collected by a temperature sensor placed on the compressor exhaust pipe; the compressor frequency f can be detected by the system.

[0056] Figure 3 A flowchart illustrating a specific embodiment of the steps for determining the predicted noise of the third throttling device based on the mid-flow temperatures of the second and third heat exchangers is shown. Figure 3 As shown, step S120 includes steps S121, S122 and S123.

[0057] Step S121: Calculate the maximum mass flow rate in the third throttling device based on the midpoint temperature of the second heat exchanger flow path and the midpoint temperature of the third heat exchanger flow path.

[0058] Specifically, the pressure difference before and after the third throttling device and the saturated liquid density at the inlet of the third throttling device are calculated based on the temperature at the middle of the flow path of the second heat exchanger and the temperature at the middle of the flow path of the third heat exchanger. The maximum mass flow rate inside the third throttling device is then calculated based on the pressure difference before and after the third throttling device and the saturated liquid density at the inlet of the third throttling device.

[0059] The temperature t in the middle of the flow path of the second heat exchanger e_h Specifically, it can be the temperature in the middle of the flow path of the second heat exchanger; the temperature t in the middle of the flow path of the third heat exchanger. e_l Specifically, it can be the temperature at the middle of the flow path of the third heat exchanger; the temperature t at the middle of the flow paths of the second and third heat exchangers. e_h t e_l The data can be collected by temperature sensors located in the middle of the flow paths of the second and third heat exchangers, respectively.

[0060] Pressure difference ΔP=a*(t1) 2 -t2 2 )+b*(t1-t2), where t1 and t2 are the saturation temperatures before and after the throttling device (valve), respectively; a and b are the fitting coefficients related to refrigerant properties (the values ​​of the same fitting coefficients are different in different fitting correlations in this invention), the temperature in the middle of the flow path of the second and third heat exchangers is the saturation temperature before and after the valve of the third throttling device, then the pressure difference ΔP before and after the third throttling device (third electronic expansion valve) is... r3 for:

[0061] ΔP r3 =a*(t) e_h 2 -t e_l 2 )+b*(t e_h -t e_l )

[0062] For example, if the refrigerant is R32, then based on the physical properties of R32 refrigerant and the above formula, the pressure difference ΔP across the third throttling device (third electronic expansion valve) can be obtained. r3 For: ΔP r3 =509.46*(t) e_h 2 -t e_l 2 )+20853*(t e_h -t e_l ).

[0063] The refrigerant saturated liquid density ρ = a*t*t + b*t + c, where t is the refrigerant temperature, and a, b, and c are fitting coefficients related to the refrigerant properties (in this invention, the values ​​of the same fitting coefficients differ in different fitting correlations). Therefore, the inlet saturated liquid density ρ of the third throttling device (third electronic expansion valve) is... r3 For: ρ r3 =a*t e_h *t e_h -bt e_h +c; For example, if the refrigerant is R32, then based on the physical properties of R32 refrigerant and the above formula, the inlet saturated liquid density ρ of the third throttling device (third electronic expansion valve) can be obtained by fitting. r3 For: ρ r3 =-0.031*t e_h *t e_h -2.7548t e_h +1051.3;

[0064] After calculating the pressure difference across the third throttling device and the saturated liquid density at the inlet of the third throttling device, the maximum mass flow rate within the third throttling device is calculated based on the pressure difference across the third throttling device and the saturated liquid density at the inlet of the third throttling device.

[0065] The maximum mass flow rate G within the third throttling device is given by: G = a * ρ * (ΔP) 0.5 'a' represents the fitting coefficient related to the refrigerant properties (the same fitting coefficient has different values ​​in different fitting correlations in this invention).

[0066] For example, if the refrigerant is R32, then based on the physical properties of R32 refrigerant and the above formula, the maximum mass flow rate G in the third throttling device can be obtained as G = 0.0283 * ρ * (ΔP). 0.5 .

[0067] Step S122: Calculate the inlet dryness of the third throttling device based on the temperature in the middle of the flow path of the second heat exchanger.

[0068] Specifically, the saturated liquid enthalpy and latent heat of phase change of the second heat exchanger are calculated based on the temperature at the middle of the flow path of the second heat exchanger. The inlet dryness fraction of the third throttling device is then calculated based on the saturated liquid enthalpy and latent heat of phase change of the second heat exchanger.

[0069] The specific enthalpy h of the subcooled or saturated refrigerant is given by: h = a*t*t + b*t + c, where a, b, and c are values ​​obtained from refrigerant property software. Then, the saturated liquid enthalpy h of the second heat exchanger is given by: e_h_f for:

[0070] h e_h_f =a*t e_h *t e_h +b*t e_h +c.

[0071] For example, if the refrigerant is R32, then based on the physical properties of R32 refrigerant and the above formula, the saturated liquid enthalpy h of the second heat exchanger can be obtained by fitting the equation. e_h_f for:

[0072] h e_h_f =0.0039*t e_h *t e_h +1.7246*t e_h +200.06.

[0073] The latent heat of phase change of the refrigerant, h = a*t*t + b*t + c, where a, b, and c are fitting coefficients related to the refrigerant's physical properties (the values ​​of the same fitting coefficients differ in different fitting correlations in this invention). Therefore, the latent heat of phase change of the second heat exchanger, h... e_h_fg =a*t e_h *t e_h -b*t e_h +c.

[0074] For example, if the refrigerant is R32, then the latent heat of phase change h of the second heat exchanger can be obtained by fitting the physical property parameters of R32. e_h_fg For: h e_h_fg =-0.0181*t e_h *t e_h -1.1988*t e_h +313.22.

[0075] Specifically, the inlet dryness fraction of the third throttling device (third electronic expansion valve) x3 = (h f -h e_h_f ) / h e_h_fg .

[0076] Among them, h fThe flash vessel outlet temperature is calculated by a fitting formula using the first heat exchanger outlet temperature, the second heat exchanger middle temperature, the third heat exchanger middle temperature and the frequency. f = f(tc_o, t suc_h_sat , t suc_l_sat , f), h f = t ft_target = 0.5*tc_o+0.25*t suc_h_sat +0.25*t suc_l_sat +a*f+c, wherein tc_o is the first heat exchanger outlet temperature, t suc_h_sat is the high temperature suction saturation temperature, t suc_l_sat is the low temperature suction saturation temperature, a and c are fitting coefficients, the same fitting coefficients in different fitting formulas in the present application have different values, and f is the compressor frequency. The high temperature evaporation temperature (high temperature suction saturation temperature) t suc_h_sat = the second heat exchanger middle temperature t e_h -high temperature suction line saturation temperature drop dt sat_suc_h , the high temperature suction line saturation temperature drop dt sat_suc_h = f(f); the high temperature suction line saturation temperature drop dt sat_suc_h is related to the compressor frequency f, for example, dt sat_suc_h = a*f*f+b*f+c, wherein a, b and c are fitting coefficients, the same fitting coefficients in different fitting formulas in the present application have different values. The low temperature evaporation temperature (low temperature suction saturation temperature) t suc_l_sat = the third heat exchanger middle temperature t e_l -low temperature suction line saturation temperature drop dt sat_suc_l , the low temperature suction line saturation temperature drop dt sat_suc_l = f(f); f(f) is obtained by fitting experimental data. The low temperature suction line saturation temperature drop dt sat_suc_l is related to the compressor frequency f, for example, dt sat_suc_l = a*f*f+b*f+c, wherein a, b and c are fitting coefficients, the same fitting coefficients in different fitting formulas in the present application have different values. The first heat exchanger outlet temperature tc_o, the second heat exchanger middle temperature t e_h and the third heat exchanger middle temperature t e_l are detected by temperature sensing bags.

[0077] In step S123, the predicted noise of the third throttling device is calculated according to the maximum mass flow rate in the third throttling device and the third throttling device inlet dryness.

[0078] The third throttling device (third electronic expansion valve) Z = a*G2 +b*G+c*x+d, wherein a ranges from -6.3*10 -7 <0, preferably -2.38*10 -7 , b ranges from 3.3*10 -3 <8.5*10 -3 , preferably 5.86*10 -3 , c ranges from 0 to 250, preferably 25.63, and d ranges from -15 to 17, preferably 0.873.

[0079] Step S130, adjusting the opening degree of the first throttling device and the second throttling device, or adjusting the rotation speed of the outdoor fan of the air conditioning system and the opening degree of the second throttling device, according to the predicted noise.

[0080] In a specific embodiment, the opening degree of the first throttling device and the second throttling device is adjusted according to the predicted noise to reduce the noise of the third throttling device. Specifically, it is judged whether the predicted noise of the third throttling device is greater than or equal to a preset threshold value; if it is judged that the predicted noise is greater than or equal to the preset threshold value, the opening degree of the first throttling device is controlled to decrease and the opening degree of the second throttling device is controlled to increase.

[0081] The first opening degree threshold value is the lower limit of the opening degree of the first throttling device, and the second opening degree threshold value is the upper limit of the opening degree of the second throttling device. If it is judged that the predicted noise is less than a preset threshold value, the step of judging whether the temperature difference between the indoor environment temperature and the set temperature is greater than or equal to a preset temperature difference threshold value is returned.

[0082] For example, when the third electronic expansion valve predicted noise Z satisfies Z 内环 设 ≥a), the value of b ranges from 25 to 36 dB(A); when Z≥b, it is considered that the noise has affected the indoor comfort, the first electronic expansion valve opening degree B1 is adjusted to decrease and the second electronic expansion valve opening degree B2 is adjusted to increase.

[0083] The above operation is used to reduce the noise by reducing the inlet dryness of the third throttling device (third electronic expansion valve). The first throttling device (first electronic expansion valve) opening degree is reduced, the flash gas temperature is reduced, thereby the second throttling device (second electronic expansion valve) inlet specific enthalpy is reduced, and finally the third throttling device (third electronic expansion valve) inlet dryness is reduced. This process requires the second throttling device (second electronic expansion valve) opening degree to be adjusted to increase (dryness is further reduced) to compensate for the total pressure drop. ​

[0084] Further, after controlling the opening of the first throttling device to decrease and the opening of the second throttling device to increase, when the opening of the first throttling device is less than or equal to a first preset opening threshold, or the opening of the second throttling device is greater than or equal to a second preset opening threshold, the current openings of the first throttling device and the second throttling device are maintained.

[0085] After the opening of the first electronic expansion valve is controlled to decrease and the opening of the second electronic expansion valve is controlled to increase according to the control logic, if the opening B1 of the first electronic expansion valve is less than or equal to c (a first preset opening threshold), or the opening B2 of the second electronic expansion valve is greater than or equal to d (a second preset opening threshold), the current openings are maintained; otherwise, the step of judging whether t 内环 -t 设 a is returned. Wherein the first preset opening threshold c is a lower limit of the opening of the first electronic expansion valve, and the second preset opening threshold d is an upper limit of the opening of the second electronic expansion valve.

[0086] In another specific embodiment, according to the predicted noise, the opening of the second throttling device and the rotation speed of the outdoor fan of the air conditioning system are adjusted to reduce the noise of the third throttling device. Specifically, it is judged whether the predicted noise of the third throttling device is greater than or equal to a preset threshold; if it is judged that the predicted noise is greater than or equal to the preset threshold, the opening of the second throttling device is controlled to increase, and the rotation speed of the outdoor fan of the air conditioning system is controlled to increase.

[0087] For example, when the predicted noise Z of the third electronic expansion valve satisfies Z < b (a preset threshold), at this time, it is considered that the noise is small and does not affect the indoor comfort, and each control parameter is maintained unchanged, and the step of judging whether the temperature difference between the indoor environment temperature and the set temperature is greater than or equal to a preset temperature difference threshold (t 内环 -t 设 a) is returned; the value of b is in the range of 25-36 dB (A); when Z ≥ b, it is considered that the noise has affected the indoor comfort, the rotation speed R0 of the outdoor fan is increased, and the opening B2 of the second electronic expansion valve is increased.

[0088] By this operation, the noise is reduced by decreasing the inlet dryness of the third electronic expansion valve. The rotation speed of the outdoor fan is increased, the cold outlet temperature is decreased, and the flash liquid temperature is synchronously decreased.

[0089] Further, after controlling the rotation speed of the outdoor fan of the air conditioning system to increase and the opening of the second throttling device to increase, when the rotation speed of the outdoor fan is greater than or equal to a preset rotation speed, or the opening of the second throttling device is greater than or equal to a second preset opening threshold, the current rotation speed of the outdoor fan and the current opening of the second throttling device are maintained.

[0090] After the control logic increases the outdoor fan rotating speed Ro and the second electronic expansion valve opening B2, if the second electronic expansion valve opening B2≥d (second preset opening threshold) or the outdoor fan rotating speed Ro≥e is met, the opening is kept; otherwise, the step of returning to the judgment t 内环 -t 设 ≥a is returned to. Wherein, the second preset opening threshold d is the upper limit of the second electronic expansion valve opening, and e is the upper limit of the outdoor fan rotating speed.

[0091] According to the above embodiment of the present application, by reducing the first throttling device (first electronic expansion valve) opening, the flash liquid specific enthalpy is reduced to reduce the third electronic expansion valve inlet dryness and the valve mass flow, and at the same time, the second throttling device (second electronic expansion valve) opening needs to be increased to compensate for the total pressure drop; or, by increasing the outdoor fan rotating speed, the outdoor heat exchanger heat exchange effect is improved to reduce the outdoor heat exchanger cold outlet temperature, thereby reducing the flash liquid specific enthalpy and the third electronic expansion valve inlet dryness and the valve mass flow, and at the same time, the second throttling device (second electronic expansion valve) opening needs to be increased to compensate for the total pressure drop.

[0092] To clearly illustrate the technical scheme of the present application, the execution flow of the control method of the air conditioning system provided by the present application is described below with several specific embodiments.

[0093] Figure 4 is a method schematic diagram of a specific embodiment of the control method of the air conditioning system provided by the present application. As shown in Figure 4 , the air conditioning system is running in refrigeration mode, and according to the indoor environment temperature, the outdoor environment temperature, the set temperature, the set indoor unit wind speed and the electronic expansion valve control algorithm, the system operating parameters and the three electronic expansion valve openings B1, B2 and B3 are determined and controlled.

[0094] After running for T1 time, the indoor ring temperature sensor temperature t 内环 is detected and compared with the set temperature t 设 . If t 内环 -t 设 ≥a, the control is continued, otherwise, the next step is entered; according to the system detection parameters, the third electronic expansion valve predicted noise total value Z is calculated. When the third electronic expansion valve predicted noise total value meets Z 内环 , the set temperature t 设 is compared. When Z≥b, it is considered that the noise has affected the indoor comfort, the first electronic expansion valve opening is reduced and the second electronic expansion valve opening is increased to reduce the noise. If the first electronic expansion valve opening B1≤c or the second electronic expansion valve opening B2≥d is met, the current openings of the first electronic expansion valve and the second electronic expansion valve are kept; otherwise, the step of returning to compare the indoor ring temperature sensor temperature t 内环The temperature t 设 comparing step.

[0095] Figure 5 is a method schematic diagram of another embodiment of the control method of the air conditioning system provided by the present application. As shown in the figure, the air conditioning system is running in refrigeration mode, and according to the indoor environment temperature, the outdoor environment temperature, the set temperature, the set indoor unit wind range and the electronic expansion valve control algorithm, the system operating parameters and the three electronic expansion valve openings B1, B2 and B3 are determined and controlled. Figure 5

[0096] After running for T1 time, the indoor ring temperature sensing bulb temperature t 内环 is detected and compared with the set temperature t 设 . If t 内环 -t 设 ≥a, the control continues, otherwise, the next step is entered; according to the system detection parameters, the third electronic expansion valve predicted noise total value Z is calculated. When the third electronic expansion valve predicted noise total value satisfies Z < b, it is considered that the noise is small and will not affect the indoor comfort, and the control parameters remain unchanged, and the step of comparing the indoor ring temperature sensing bulb temperature t 内环 with the set temperature t 设 is returned. When Z ≥ b, it is considered that the noise has affected the indoor comfort, and the outdoor fan speed Ro and the second electronic expansion valve opening B2 are adjusted. If the second electronic expansion valve opening B2 ≥ d or the outdoor fan speed Ro ≥ e, the outdoor fan speed and the second electronic expansion valve opening are kept; otherwise, the step of comparing the indoor ring temperature sensing bulb temperature t 内环 with the set temperature t 设 is returned.

[0097] Figure 6 is a structure block diagram of an embodiment of the control device of the air conditioning system provided by the present application. As shown in the figure, the control device 100 of the air conditioning system comprises a judgment unit 110, a determination unit 120 and an adjustment unit 130. Figure 6

[0098] The judgment unit 110 is used for judging whether the temperature difference between the indoor environment temperature and the set temperature is greater than or equal to a preset temperature difference threshold when the air conditioning system is running in refrigeration mode.

[0099] ​​Specifically, after the air conditioning system is started to heat, the compressor frequency, the outdoor fan speed and / or the indoor fan speed of the air conditioning system are determined according to the outdoor environment temperature, the indoor environment temperature and the indoor set temperature, and the initial opening degrees of the first throttling device, the second throttling device and the third throttling device are determined; the air conditioning system is controlled to operate according to the determined compressor frequency, the outdoor fan speed and / or the indoor fan speed and the determined initial opening degrees of the first throttling device, the second throttling device and the third throttling device. During the operation of the air conditioning system, the opening degrees of the first throttling device, the second throttling device and the third throttling device can also be adjusted according to the operating parameters of the air conditioning system.

[0100] The compressor frequency, the outdoor fan speed and / or the indoor fan speed of the air conditioning system are determined according to the outdoor environment temperature, the indoor environment temperature and the set temperature according to the pre-set values in the start-up stage. If the current operating mode of the air conditioning is the cooling mode, the initial opening degrees of the first throttling device, the second throttling device and the third throttling device are determined according to the compressor frequency, the indoor environment temperature and the outdoor environment temperature, wherein the initial opening degrees of the first throttling device, the second throttling device and the third throttling device corresponding to different compressor frequencies, indoor environment temperatures and outdoor environment temperatures can be determined by experiments in advance.

[0101] The first throttling device, the second throttling device and the third throttling device can be electronic expansion valves. After the air conditioning receives a start-up instruction, the compressor frequency, the outdoor fan speed and / or the indoor fan speed operate according to the pre-set values in the start-up stage according to the indoor and outdoor environment temperatures detected by the temperature sensing bags and the user set temperature, and the opening degrees of the outdoor electronic expansion valves (the first and second electronic expansion valves) and the indoor electronic expansion valve (the third electronic expansion valve) are calculated according to the temperatures detected by the temperature sensing bags.

[0102] Preferably, after the air conditioning system is started to operate for a pre-set time, it is judged whether the temperature difference between the indoor environment temperature and the set temperature is greater than or equal to a pre-set temperature difference threshold. Specifically, after the air conditioning system is started to operate for a first pre-set time T1, it is judged whether the temperature difference between the indoor environment temperature t 内环 and the set temperature t 设 is greater than or equal to a pre-set temperature difference threshold a, i.e. whether t 内环 -t 设 ≥a. The first pre-set time T1 has a value range of 2-10 minutes. The pre-set temperature difference threshold a has a value range of 0-5℃, and is preferably 2℃. The indoor environment temperature t 内环 can be collected by the environment temperature sensing bag arranged in the indoor unit of the air conditioning, and the set temperature t 设 can be set by the user.

[0103] The determining unit 120 is configured to determine the predicted noise of the third throttling device according to the second heat exchanger midstream temperature and the third heat exchanger midstream temperature if the judging unit judges that the temperature difference is less than the preset temperature difference threshold.

[0104] That is, if t 内环 -t 设 ≥a is not satisfied, the predicted noise of the third throttling device is determined according to the second heat exchanger midstream temperature and the third heat exchanger midstream temperature. The second and third heat exchanger midstream temperatures t e_h , t e_l may be collected by temperature sensing bulbs arranged at the midstream positions of the second and third heat exchangers respectively. dis The exhaust temperature t e_h may be collected by a temperature sensing bulb arranged on the compressor exhaust pipe. e_l The compressor frequency f may be detected by the system.

[0105] In a specific embodiment, the determining unit 120 determines the predicted noise of the third throttling device according to the second heat exchanger midstream temperature and the third heat exchanger midstream temperature, which includes steps S121, S122 and S123.

[0106] Step S121 calculates the maximum mass flow rate in the third throttling device according to the second heat exchanger midstream temperature and the third heat exchanger midstream temperature.

[0107] Specifically, the pressure difference before and after the third throttling device and the third throttling device inlet saturated liquid density are calculated according to the second heat exchanger midstream temperature and the third heat exchanger midstream temperature, and the maximum mass flow rate in the third throttling device is calculated according to the pressure difference before and after the third throttling device and the third throttling device inlet saturated liquid density.

[0108] The second heat exchanger midstream temperature t e_h may be specifically the second heat exchanger midstream temperature. The third heat exchanger midstream temperature t e_l may be specifically the third heat exchanger midstream temperature. The second and third heat exchanger midstream temperatures t e_h , t e_l may be collected by temperature sensing bulbs arranged at the midstream positions of the second and third heat exchangers respectively.

[0109] The pressure difference ΔP=a*(t 2 -t2 2)+b*(t1-t2), wherein t1 and t2 are the saturation temperatures before and after the throttling device (valve), respectively, and a and b are fitting coefficients related to the properties of the refrigerant (the values of the same fitting coefficients are different in different fitting correlations in the present application); the temperature at the middle of the flow path of the second and third heat exchangers, i.e. the saturation temperatures before and after the valve of the third throttling device, is t r3 .

[0110] ΔP r3 = a*(t e_h 2 -t e_l 2 )+b*(t e_h -t e_l )

[0111] For example, the refrigerant is R32, and according to the properties of R32 refrigerant and the above formula, the pressure difference ΔP across the third throttling device (third electronic expansion valve) can be fitted as follows: r3 ΔP r3 = 509.46*(t e_h 2 -t e_l 2 )+20853*(t e_h -t e_l ).

[0112] The saturated liquid density of the refrigerant is ρ = a*t*t + b*t + c, wherein t is the temperature of the refrigerant, and a, b and c are fitting coefficients related to the properties of the refrigerant (the values of the same fitting coefficients are different in different fitting correlations in the present application); the saturated liquid density ρ at the inlet of the third throttling device (third electronic expansion valve) is r3 ρ r3 = a*t e_h *t e_h -bt e_h +c; for example, the refrigerant is R32, and according to the properties of R32 refrigerant and the above formula, the saturated liquid density ρ at the inlet of the third throttling device (third electronic expansion valve) can be fitted as follows: r3 ρ r3 = -0.031*t e_h *t e_h -2.7548t e_h +1051.3.

[0113] After the pressure difference across the third throttling device and the saturated liquid density at the inlet of the third throttling device are calculated, the maximum mass flow rate in the third throttling device is calculated according to the pressure difference across the third throttling device and the saturated liquid density at the inlet of the third throttling device.

[0114] The maximum mass flow rate G in the third throttling device = a*P*(AP) 0.5 a is a fitting coefficient related to the refrigerant properties (the values of the same fitting coefficient are different in different fitting correlations in the present application).

[0115] For example, the refrigerant is R32, and according to the R32 refrigerant properties, the maximum mass flow rate G in the third throttling device = 0.0283*P*(AP) can be fitted according to the above formula. 0.5 .

[0116] Step S122, calculating the third throttling device inlet dryness according to the second heat exchanger middle part temperature.

[0117] Specifically, the second heat exchanger saturated liquid enthalpy and the second heat exchanger phase change latent heat are calculated according to the second heat exchanger middle part temperature. The third throttling device inlet dryness is calculated according to the second heat exchanger saturated liquid enthalpy and the second heat exchanger phase change latent heat.

[0118] The specific supercooling or saturated refrigerant enthalpy h = a*t*t + b*t + c, wherein a, b, and c are fitting values obtained from refrigerant property software, and the second heat exchanger saturated liquid enthalpy h e_h_f is:

[0119] h e_h_f = a*t e_h *t e_h +b*t e_h +c.

[0120] For example, the refrigerant is R32, and according to the R32 refrigerant properties, the second heat exchanger saturated liquid enthalpy h e_h_f is:

[0121] h e_h_f = 0.0039*t e_h *t e_h +1.7246*t e_h +200.06.

[0122] The refrigerant phase change latent heat h = a*t*t + b*t + c, wherein a, b, and c are fitting coefficients related to the refrigerant properties (the values of the same fitting coefficient are different in different fitting correlations in the present application), and the second heat exchanger phase change latent heat he _h_fg = a*t e_h *t e_h -b*t e_h +c.

[0123] For example, the refrigerant is R32, and according to the R32 refrigerant properties, the second heat exchanger phase change latent heat h e_h_fg is: he_h_fg = -0.0181 * t e_h *t e_h -1.1988 * t e_h + 313.22.

[0124] Specifically, the third throttling device (third electronic expansion valve) inlet dryness x3 = (h f -h e_h_f ) / h e_h_fg .

[0125] Wherein, h f is the flash vessel outlet temperature, which is calculated by the first heat exchanger outlet temperature, the second heat exchanger middle temperature, the third heat exchanger middle temperature, and the frequency through a fitting formula. The fitting correlation formula is used to calculate: h f = f (tc_o, t suc_h_sat , t suc_l_sat , f), h f = t ft_target = 0.5 * tc_o + 0.25 * t suc_h_sat + 0.25 * t suc_l_sat + a * f + c, wherein tc_o is the first heat exchanger outlet temperature, t suc_h_sat is the high temperature suction saturation temperature, t suc_l_sat is the low temperature suction saturation temperature, a and c are fitting coefficients, the values of the same (identified) fitting coefficients in different fitting correlations in the present application are different, and f is the compressor frequency. For example, the high temperature evaporation temperature (high temperature suction saturation temperature) t suc_h_sat = the second heat exchanger middle temperature t e_h - the high temperature suction line saturation temperature drop dt sat_suc_h , the high temperature suction line saturation temperature drop dt sat_suc_h = f (f); the high temperature suction line saturation temperature drop dt sat_suc_h is related to the compressor frequency f, for example: dt sat_suc_h = a * f * f + b * f + c, wherein a, b and c are fitting coefficients, the values of the same (identified) fitting coefficients in different fitting correlations in the present application are different. The low temperature evaporation temperature (low temperature suction saturation temperature) t suc_l_sat = the third heat exchanger middle temperature t e_l - the low temperature suction line saturation temperature drop dt sat_suc_l , the low temperature suction line saturation temperature drop dt sat_suc_l = f (f); f (f) is obtained by fitting according to experimental data. The low temperature suction line saturation temperature drop dt sat_suc_l is related to the compressor frequency f, for example: dt sat_suc_l= a*f*f + b*f + c, wherein a, b and c are fitting coefficients, and the values of the fitting coefficients with the same (identified) fitting coefficients in different fitting correlations are different in the present application. The first heat exchanger outlet temperature tc_o, the second heat exchanger middle section temperature t e_h , and the third heat exchanger middle section temperature t e_l are detected by temperature sensing bulbs.

[0126] In step S123, the predicted noise of the third throttling device is calculated according to the maximum mass flow rate in the third throttling device and the dryness at the inlet of the third throttling device.

[0127] The third throttling device (third electronic expansion valve) Z = a*G 2 +b*G+c*x+d, wherein a has a value range of -6.3*10 -7 ~0, preferably -2.38*10 -7 , b has a value range of 3.3*10 -3 ~8.5*10 -3 , preferably 5.86*10 -3 , c has a value range of 0~250, preferably 25.63, and d has a value range of -15~17, preferably 0.873.

[0128] The adjusting unit 130 is configured to adjust the opening degree of the first throttling device and the second throttling device, or adjust the rotation speed of the outdoor fan and the opening degree of the second throttling device, according to the predicted noise determined by the determining unit.

[0129] In a specific embodiment, the adjusting unit 130 adjusts the opening degree of the first throttling device and the second throttling device according to the predicted noise, so as to reduce the noise of the third throttling device. Specifically, it is judged whether the predicted noise of the third throttling device is greater than or equal to a preset threshold value; if it is judged that the predicted noise is greater than or equal to the preset threshold value, the opening degree of the first throttling device is controlled to decrease, and the opening degree of the second throttling device is controlled to increase.

[0130] The first opening degree threshold value is the lower limit of the opening degree of the first throttling device, and the second opening degree threshold value is the upper limit of the opening degree of the second throttling device. If it is judged that the predicted noise is less than the preset threshold value, the step of judging whether the temperature difference between the indoor environment temperature and the set temperature is greater than or equal to a preset temperature difference threshold value is returned to.

[0131] For example, when the predicted noise Z of the third electronic expansion valve satisfies Z < b (the preset threshold value), it is considered that the noise is small and does not affect the indoor comfort, and each control parameter remains unchanged, and the step of judging whether the temperature difference between the indoor environment temperature and the set temperature is greater than or equal to a preset temperature difference threshold value (t 内环 -t设 The step of a) is performed. The value range of b is 25-36 dB(A). When Z≥b, it is considered that the noise has affected the indoor comfort, the first electronic expansion valve opening B1 is reduced, and the second electronic expansion valve opening B2 is increased.

[0132] The noise is reduced by reducing the third throttling device (third electronic expansion valve) inlet dryness through the above operation. The first throttling device (first electronic expansion valve) opening is reduced, the flash gas temperature is reduced, the second throttling device (second electronic expansion valve) inlet specific enthalpy is reduced, and finally the third throttling device (third electronic expansion valve) inlet dryness is reduced. This process requires the second throttling device (second electronic expansion valve) opening to be increased accordingly (dryness is further reduced) to compensate for the total pressure drop.

[0133] Further, the adjusting unit 130 is further configured to: after the opening of the first throttling device is controlled to be reduced and the opening of the second throttling device is controlled to be increased, when the opening of the first throttling device is less than or equal to a first preset opening threshold, or the opening of the second throttling device is greater than or equal to a second preset opening threshold, the current openings of the first throttling device and the second throttling device are maintained.

[0134] After the first electronic expansion valve opening is reduced and the second electronic expansion valve opening is increased according to the control logic, if the first electronic expansion valve opening B1≤c (first preset opening threshold) or the second electronic expansion valve opening B2≥d (second preset opening threshold) is satisfied, the opening is maintained; otherwise, return to step t 内环 -t 设 The step of a) is performed. The first preset opening threshold c is the lower limit of the first electronic expansion valve opening, and the second preset opening threshold d is the upper limit of the second electronic expansion valve opening.

[0135] In another specific embodiment, the adjusting unit 130 adjusts the opening of the second throttling device and the speed of the outdoor fan of the air conditioning system according to the predicted noise of the third throttling device, so as to reduce the noise of the third throttling device. Specifically, it is judged whether the predicted noise of the third throttling device is greater than or equal to a preset threshold; if it is judged that the predicted noise is greater than or equal to the preset threshold, the opening of the second throttling device is controlled to be increased, and the speed of the outdoor fan of the air conditioning system is controlled to be increased.

[0136] For example, when the third electronic expansion valve predicted noise Z satisfies Z<b (preset threshold), it is considered that the noise is small and does not affect the indoor comfort, and each control parameter is maintained unchanged, and it is returned to judge whether the temperature difference between the indoor environment temperature and the set temperature is greater than or equal to a preset temperature difference threshold (t 内环 -t 设The step of ≥a) is performed; the value range of b is 25-36dB(A); when Z≥b, it is considered that the noise has affected the indoor comfort, the outdoor fan speed R0 is increased, and the second electronic expansion valve opening B2 is increased.

[0137] The third electronic expansion valve inlet dryness is reduced by the operation, the outdoor fan speed is increased, the cold outlet temperature is reduced, and the flash liquid temperature is synchronously reduced.

[0138] Further, the adjusting unit 130 is further configured to: after the outdoor fan speed of the air conditioning system is controlled to increase and the opening of the second throttling device is controlled to increase, when the outdoor fan speed is greater than or equal to a preset speed, or the opening of the second throttling device is greater than or equal to a second preset opening threshold, the current speed of the outdoor fan and the current opening of the second throttling device are maintained.

[0139] After the outdoor fan speed Ro and the second electronic expansion valve opening B2 are increased according to the control logic, if the second electronic expansion valve opening B2≥d (the second preset opening threshold) or the outdoor fan speed Ro≥e is met, the opening is maintained; otherwise, the judgment t is returned. 内环 -t 设 The step of ≥a) is performed. The second preset opening threshold d is the upper limit of the second electronic expansion valve opening, and e is the upper limit of the outdoor fan speed.

[0140] The application further provides a storage medium corresponding to the control method of the air conditioning system, and the storage medium has a computer program stored thereon, and the computer program is executed by a processor to implement the steps of the method.

[0141] The application further provides an air conditioning system corresponding to the control method of the air conditioning system, and the air conditioning system comprises a processor, a memory and a computer program stored on the memory and capable of running on the processor, and the processor executes the computer program to implement the steps of the method.

[0142] The application further provides an air conditioning system corresponding to the control device of the air conditioning system, and the air conditioning system comprises the control device of the air conditioning system.

[0143] The application further provides a computer program product corresponding to the control method of the air conditioning system, and the computer program product comprises a computer program, and the computer program is executed by a processor to implement the steps of the method.

[0144] Accordingly, the scheme provided by the application can reduce the electronic expansion valve flow noise and improve the indoor comfort while considering the capacity and energy efficiency in view of the electronic expansion valve flow noise problem of the indoor unit side of the air conditioning system.

[0145] According to the technical scheme of the present application, the potential relationship between the system state parameters and the refrigerant property parameters is empirically fitted, the maximum mass flow rate in the electronic expansion valve of the indoor unit and the inlet dryness are accurately calculated, so as to calculate the predicted noise of the electronic expansion valve of the indoor unit, and then the opening of the throttling device of the outdoor unit or the rotation speed of the outdoor fan is controlled to reduce the noise of the electronic expansion valve of the indoor unit.

[0146] According to the technical scheme of the present application, the total value of the electronic expansion valve noise is associated with the main influence parameters, i.e., the maximum mass flow rate in the valve and the inlet dryness. When the fitted predicted noise total value is higher than a certain set value, it is considered that the flow noise is too high, and the noise is reduced by adjusting the system parameters to reduce the inlet dryness of the electronic expansion valve.

[0147] The functions described herein can be implemented in hardware, software executed by a processor, firmware, or any combination thereof. If implemented in software executed by a processor, the functions can be stored on or transferred over as one or more instructions or code on a computer-readable medium. Other examples and implementations are within the scope and spirit of the disclosure and appended claims. For example, due to the nature of software, functions described above can be implemented using software executed by a processor, hardware, firmware, hardwiring, or combinations of any of these. Also, each of the functions can be implemented as a separate function or combined with others in a single function.

[0148] In several embodiments provided in the present application, it should be understood that the disclosed technical content can be implemented by other ways. Among them, the above-mentioned device embodiments are only schematic, for example, the division of the units can be a logical function division, and actual implementation can have another division way, for example, a plurality of units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point, the coupling or direct coupling or communication connection between the units or modules shown or discussed can be indirect coupling or communication connection through some interfaces, units or modules, which can be electrical or other forms.

[0149] The units described as separate components can or can not be physically separate, and the components of the control device can or can not be physical units, i.e., can be located in one place or can be distributed on multiple units. Part or all of the units can be selected according to actual needs to achieve the purpose of the present embodiment scheme.

[0150] The integrated unit, if implemented in the form of a software function unit and sold or used as an independent product, can be stored in a computer readable storage medium. Based on such understanding, the technical solutions of the present application or the entire or part of the technical solutions that make contributions to the related art can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes a plurality of instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the method described in the various embodiments of the present application. The aforementioned storage medium includes a U disk, a read-only memory (ROM), a random access memory (RAM), a mobile hard disk, a magnetic disk or an optical disk, and various media that can store program codes.

[0151] The above only describes the embodiments of the present application and is not intended to limit the present application. For those skilled in the art, the present application can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the scope of the claims of the present application.

Claims

1. A control method of an air conditioning system, characterized by, The air conditioning system comprises a compressor, a first heat exchanger, a second heat exchanger, a third heat exchanger, a first throttling device, a second throttling device, a third throttling device, a first four-way reversing valve, a second four-way reversing valve and a flash tank, the gas outlet end of the flash tank is connected with the gas supplement end of the compressor, the inlet end of the flash tank is connected with the first heat exchanger, the first throttling device is arranged on the pipeline between the flash tank and the first heat exchanger, the second heat exchanger and the third heat exchanger are connected to the flash tank through the second throttling device after being connected in parallel, and the third throttling device is arranged on the pipeline between the third heat exchanger and the second heat exchanger connected in parallel; The control method comprises: When the air conditioning system is operated in refrigeration mode, it is judged whether the temperature difference between the indoor environment temperature and the set temperature is greater than or equal to a preset temperature difference threshold value; If it is judged that the temperature difference is less than the preset temperature difference threshold value, the predicted noise of the third throttling device is determined according to the middle part temperature of the second heat exchanger flow path and the middle part temperature of the third heat exchanger flow path, comprising: the maximum mass flow rate in the third throttling device is calculated according to the middle part temperature of the second heat exchanger flow path and the middle part temperature of the third heat exchanger flow path; the third throttling device inlet dryness is calculated according to the middle part temperature of the second heat exchanger flow path; the predicted noise of the third throttling device is calculated according to the maximum mass flow rate in the third throttling device and the third throttling device inlet dryness; According to the predicted noise, the opening degree of the first throttling device and the second throttling device is adjusted, or the rotation speed of the outdoor fan of the air conditioning system and the opening degree of the second throttling device are adjusted.

2. The method of claim 1, wherein, According to the middle part temperature of the second heat exchanger flow path and the middle part temperature of the third heat exchanger flow path, the maximum mass flow rate in the third throttling device is calculated, comprising: According to the middle part temperature of the second heat exchanger flow path and the middle part temperature of the third heat exchanger flow path, the front and back pressure difference of the third throttling device and the third throttling device inlet saturated liquid density are calculated; According to the front and back pressure difference of the third throttling device and the third throttling device inlet saturated liquid density, the maximum mass flow rate in the third throttling device is calculated; And / or, According to the middle part temperature of the second heat exchanger flow path, the second heat exchanger saturated liquid enthalpy and the second heat exchanger phase change latent heat are calculated, comprising: According to the middle part temperature of the second heat exchanger flow path, the second heat exchanger saturated liquid enthalpy and the second heat exchanger phase change latent heat are calculated; According to the second heat exchanger saturated liquid enthalpy and the second heat exchanger phase change latent heat, the third throttling device inlet dryness is calculated.

3. The method according to claim 1 or 2, characterized in that, According to the predicted noise, the opening degree of the first throttling device and the second throttling device is adjusted, comprising: It is judged whether the predicted noise of the third throttling device is greater than or equal to a preset threshold value; If it is judged that the predicted noise is greater than or equal to the preset threshold value, the opening degree of the first throttling device is controlled to decrease, and the opening degree of the second throttling device is controlled to increase.

4. The method of claim 3, wherein, Further comprising: After the opening degree of the first throttling device is controlled to decrease and the opening degree of the second throttling device is controlled to increase, when the opening degree of the first throttling device is less than or equal to a first preset opening degree threshold, or the opening degree of the second throttling device is greater than or equal to a second preset opening degree threshold, the current opening degrees of the first throttling device and the second throttling device are maintained.

5. The method according to claim 1 or 2, characterized in that, According to the predicted noise, the opening degree of the second throttling device and the rotation speed of the outdoor fan of the air conditioning system are adjusted, including: It is judged whether the predicted noise of the third throttling device is greater than or equal to a preset threshold; if it is judged that the predicted noise is greater than or equal to the preset threshold, the rotation speed of the outdoor fan of the air conditioning system is controlled to increase, and the opening degree of the second throttling device is controlled to increase.

6. The method of claim 5, wherein, Further comprising: After the rotation speed of the outdoor fan of the air conditioning system is controlled to increase and the opening degree of the second throttling device is controlled to increase, when the rotation speed of the outdoor fan is greater than or equal to a preset rotation speed, or the opening degree of the second throttling device is greater than or equal to a second preset opening degree threshold, the current rotation speed of the outdoor fan and the current opening degree of the second throttling device are maintained.

7. A control device of an air conditioning system, characterized by comprising: The air conditioning system comprises a compressor, a first heat exchanger, a second heat exchanger, a third heat exchanger, a first throttling device, a second throttling device, a third throttling device, a first four-way reversing valve, a second four-way reversing valve and a flash tank, a gas outlet end of the flash tank is connected with a gas supplement end of the compressor, an inlet end of the flash tank is connected with the first heat exchanger, the first throttling device is arranged on a pipeline between the flash tank and the first heat exchanger, the second heat exchanger and the third heat exchanger are connected to the flash tank through the second throttling device after being connected in parallel, and the third throttling device is arranged on a pipeline in which the third heat exchanger and the second heat exchanger are connected in parallel; The control device comprises: a judging unit configured to judge whether a temperature difference between an indoor environment temperature and a set temperature is greater than or equal to a preset temperature difference threshold when the air conditioning system is in refrigeration operation; a determining unit configured to determine a predicted noise of the third throttling device according to a second heat exchanger flow path middle temperature and a third heat exchanger flow path middle temperature if the judging unit judges that the temperature difference is less than the preset temperature difference threshold, including: calculating a maximum mass flow rate in the third throttling device according to the second heat exchanger flow path middle temperature and the third heat exchanger flow path middle temperature; calculating an inlet dryness of the third throttling device according to the second heat exchanger flow path middle temperature; and calculating the predicted noise of the third throttling device according to the maximum mass flow rate in the third throttling device and the inlet dryness of the third throttling device; an adjusting unit configured to adjust the opening degrees of the first throttling device and the second throttling device, or adjust the opening degree of the second throttling device and the rotation speed of the outdoor fan of the air conditioning system according to the predicted noise determined by the determining unit.

8. A storage medium, characterized by A computer program is stored thereon, and the program is executed by a processor to implement the steps of the method of any one of claims 1-6. A computer program is stored thereon, and the program is executed by a processor to implement the steps of the method of any one of claims 1-6.

9. An air conditioning system, characterised in that, A computer program product comprising a processor, a memory, and a computer program stored on the memory and loadable on the processor, the processor implementing the steps of the method according to any one of claims 1 to 6 when executing the program, or a control device according to claim 7.

10. A computer program product, characterised in that, A computer program product comprising a computer program, the computer program implementing the steps of the method according to any one of claims 1 to 6 when executed by a processor.

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