Air conditioning system, control method and device thereof, storage medium and program product

Abstract

The invention provides an air conditioning system and a control method and device thereof, a storage medium and a program product, 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 control method comprises the steps that when the air conditioning system operates, whether the temperature difference value between the indoor environment temperature and the set temperature is larger than or equal to a preset temperature difference threshold value or not is judged; if it is judged that the temperature difference value is smaller than the preset temperature difference threshold value, the predicted noise of a third throttling device is determined according to the flow path middle temperature of the second heat exchanger and the flow path middle temperature of the third heat exchanger; and according to the predicted noise, the opening degree of a first throttling device and the opening degree of a second throttling device are adjusted, or the rotating speed of an outer draught fan and the opening degree of the second throttling device are adjusted. According to the scheme, the flow noise of the electronic expansion valve can be reduced while the energy efficiency is considered.

Description

Technical Field

[0001] The present invention 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 Art

[0002] In the related technology, an electronic expansion valve is used on the machine side of a three-pipe dual-temperature parallel compression system to control the dual-temperature evaporation temperature difference and refrigerant flow distribution. Since the refrigerant before the valve is in a two-phase state, a two-phase flow noise problem is generated, which will have a certain impact on user comfort. Summary of the invention

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

[0004] On one hand, the present invention provides a control method for an air-conditioning system, wherein 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, wherein the gas outlet end of the flasher is connected to the gas supply end of the compressor, the inlet end of the flasher is connected to the first heat exchanger, the first throttling device is arranged on the pipeline between the flasher and the first heat exchanger, and after the second heat exchanger and the third heat exchanger are connected in parallel, they are connected to the flasher through the second throttling device. , the third throttling device is arranged on the pipeline in parallel with the third heat exchanger and the second heat exchanger; the control method comprises: when the air-conditioning system is in cooling operation, judging 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 it is judged that the temperature difference is less than the preset temperature difference threshold, determining the predicted noise of the third throttling device according to the middle temperature of the second heat exchanger flow path and the middle temperature of the third heat exchanger flow path; according to the predicted noise, adjusting the opening of the first throttling device and the second throttling device, or adjusting the speed of the external fan of the air-conditioning system and the opening of the second throttling device.

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

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

[0007] Optionally, the opening of the first throttling device and the second throttling device are adjusted 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 it is judged that the predicted noise is greater than or equal to the preset threshold, controlling the opening of the first throttling device to decrease, and controlling the opening of the second throttling device to increase.

[0008] Optionally, it also includes: after controlling the opening of the first throttling device to decrease and controlling 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 when the opening of the second throttling device is greater than or equal to a second preset opening threshold, maintaining the current openings of the first throttling device and the second throttling device.

[0009] Optionally, according to the predicted noise, the speed of the external fan of the air-conditioning system and the opening of the second throttling device are adjusted, including: 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, then controlling the speed of the external fan of the air-conditioning system to increase, and controlling the opening of the second throttling device to increase.

[0010] Optionally, it also includes: after controlling the speed of the external fan of the air-conditioning system to increase and controlling the opening of the second throttling device to increase, when the speed of the external fan 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, maintaining the current speed of the external fan and the current opening of the second throttling device.

[0011] Another aspect of the present invention provides a control device for 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 flasher, the gas outlet end of the flasher is connected to the air supply end of the compressor, the inlet end of the flasher is connected to 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 in parallel and are connected to the flasher through the second throttling device, and the third throttling device is arranged on the third heat exchanger. The heat exchanger is on a pipeline in parallel with the second heat exchanger; the control device includes: a judgment unit, which is used 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 when the air-conditioning system is in cooling operation; a determination unit, which is used to determine the predicted noise of the third throttling device according to the middle temperature of the second heat exchanger flow path and the middle temperature of the third heat exchanger flow path if the judgment unit judges that the temperature difference is less than the preset temperature difference threshold; an adjustment unit, which is used to adjust the opening of the first throttling device and the second throttling device according to the predicted noise determined by the determination unit, or adjust the external fan speed of the air-conditioning system and the opening of the second throttling device.

[0012] Optionally, the determination unit determines the predicted noise of the third throttling device according to the middle temperature of the second heat exchanger flow path and the middle temperature of the third heat exchanger flow path, including: calculating the maximum mass flow rate in the third throttling device according to the middle temperature of the second heat exchanger flow path and the middle temperature of the third heat exchanger flow path; calculating the inlet dryness of the third throttling device according to the middle temperature of the second heat exchanger flow path; 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 determination unit calculates the maximum mass flow rate in the third throttling device according to the middle temperature of the second heat exchanger flow path and the middle temperature of the third heat exchanger flow path, including: calculating the front and rear pressure difference of the third throttling device and the saturated liquid density at the inlet of the third throttling device according to the middle temperature of the second heat exchanger flow path and the middle temperature of the third heat exchanger flow path; calculating the maximum mass flow rate in the third throttling device according to the front and rear pressure difference of the third throttling device and the saturated liquid density at the inlet of the third throttling device; and / or, the determination unit calculates the inlet dryness of the third throttling device according to the middle temperature of the second heat exchanger flow path, including: calculating the saturated liquid enthalpy of the second heat exchanger and the latent heat of phase change of the second heat exchanger according to the middle temperature of the second heat exchanger flow path; calculating the inlet dryness of the third throttling device according to the saturated liquid enthalpy of the second heat exchanger and the latent heat of phase change of the second heat exchanger.

[0014] Optionally, the adjustment unit adjusts the opening 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 it is judged that the predicted noise is greater than or equal to the preset threshold, controlling the opening of the first throttling device to decrease, and controlling the opening of the second throttling device to increase.

[0015] Optionally, the adjustment unit is also used to: after controlling the opening of the first throttling device to decrease and controlling 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 when the opening of the second throttling device is greater than or equal to a second preset opening threshold, maintain the current opening of the first throttling device and the second throttling device.

[0016] Optionally, the adjustment unit adjusts the speed of the external fan of the air-conditioning system and the opening of 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 it is judged that the predicted noise is greater than or equal to the preset threshold, controlling the speed of the external fan of the air-conditioning system to increase, and controlling the opening of the second throttling device to increase.

[0017] Optionally, the adjustment unit is also used to: after controlling the speed of the external fan of the air-conditioning system to increase and controlling the opening of the second throttling device to increase, when the speed of the external fan 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, maintain the current speed of the external fan and the current opening of the second throttling device.

[0018] Another aspect of the present invention provides a storage medium having a computer program stored thereon, wherein the program implements the steps of any of the aforementioned methods when executed by a processor.

[0019] In another aspect, the present invention 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 aforementioned methods when executing the program.

[0020] In another aspect, the present invention provides an air conditioning system, comprising any of the aforementioned control devices.

[0021] In another aspect, the present invention provides a computer program product, comprising a computer program, wherein when the computer program is executed by a processor, the steps of any of the aforementioned methods are implemented.

[0022] According to the technical solution of the present invention, the flow noise problem of the electronic expansion valve on the indoor unit side of the air-conditioning system can be solved, while taking into account the energy efficiency, the flow noise of the electronic expansion valve can be reduced and the indoor comfort can be improved.

[0023] According to the technical solution of the present invention, the potential relationship between the system state parameters and the refrigerant physical properties is empirically fitted, and the maximum mass flow rate and inlet dryness in the indoor electronic expansion valve are accurately calculated, so as to calculate the predicted noise of the electronic expansion valve on the indoor unit side, and then reduce the noise of the electronic expansion valve on the indoor unit side by controlling the opening of the throttling device on the outdoor unit side or the speed of the outdoor fan.

[0024] According to the technical solution of the present invention, the total value of the electronic expansion valve noise is associated with its main influencing parameters, namely, the maximum mass flow rate in the valve and the valve inlet dryness. When the total value of the fitting prediction noise 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 electronic expansion valve inlet dryness. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

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

[0027] Figure 2 A schematic diagram of the refrigeration operation mode of the air-conditioning system provided by the present invention;

[0028] Figure 3 A flow chart showing a specific implementation of the step of determining the predicted noise of the third throttling device according to the middle temperature of the second heat exchanger flow path and the middle temperature of the third heat exchanger flow path;

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

[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 invention;

[0031] Figure 6 is a structural block diagram of an embodiment of a control device for an air conditioning system provided by the present invention;

[0032] The accompanying drawings are marked as follows:

[0033] 1. Compressor; 1a. Compressor parallel air cylinder; 1b. Compressor first master cylinder; 1c. Compressor second master 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 purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the specific embodiments of the present invention and the corresponding drawings. 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 making creative work are within the scope of protection of the present invention.

[0035] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0036] When the three-pipe dual-temperature parallel compression system is in cooling operation, the inlet side of the indoor electronic expansion valve is in a two-phase state. When the two-phase refrigerant flows through the electronic expansion valve, it will produce flow noise problems of varying degrees. Since this valve is on the indoor side, when the noise is too loud, it will affect the indoor comfort.

[0037] The present invention provides a control method and a control device for an air conditioning system. The air conditioning system may specifically be a heat pump air conditioning system.

[0038] 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 flasher, wherein the gas outlet of the flasher is connected to the air supply end of the compressor, the inlet of the flasher is connected to 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 in parallel and connected to the flasher through the second throttling device, and the third throttling device is arranged on the pipeline in which the indoor second heat exchanger is connected in parallel with 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 This is a schematic diagram of the refrigeration operation mode of the air-conditioning system provided by the present invention.

[0040] like Figure 2 As shown, the air-conditioning system comprises: the air-conditioning system comprises a compressor 1, a first heat exchanger 4, a first throttling device (preferably a first electronic expansion valve) 5, a flasher 6, a 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 to the first heat exchanger 4, the gas outlet end of the flasher 6 is connected to the air supply end of the compressor, one end of the first heat exchanger 4 is connected to the first throttling device (preferably a first electronic expansion valve) 5, and the other end is connected to the exhaust end or the intake 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 exhaust end or the intake end of the compressor.

[0041] The compressor 1 is a three-cylinder parallel compressor. The three-cylinder parallel compressor 1 includes: a compressor parallel air supply cylinder 1a, a compressor first master cylinder 1b and a compressor second master cylinder 1c. The compressor parallel air supply cylinder 1a, the compressor first master cylinder 1b and the compressor second master cylinder 1c. The air intake end of the compressor parallel air supply cylinder 1a is the air supply end and is connected to the gas outlet end of the flasher 6, and the exhaust end of the compressor first master cylinder 1b, the compressor second master cylinder 1c and the compressor parallel air supply cylinder 1a are all connected.

[0042] The indoor heat exchanger includes a second heat exchanger 9 and a third heat exchanger 10. The second heat exchanger 9 can be connected to the second master cylinder 1c of the compressor, and the third heat exchanger 10 can be connected to the first master cylinder 1b of the compressor. One end of the third heat exchanger 10 is connected to the third throttling device (preferably the third electronic expansion valve) 8 and then connected to the pipeline where the second heat exchanger 9 is located, and the merged pipeline is connected to the second throttling device (preferably the second electronic expansion valve) 7.

[0043] The air conditioning system also includes a first four-way valve 2 and a second four-way valve 3, the D end of the first four-way valve 2 is connected to the exhaust end of the compressor 1, the E end is connected to the second heat exchanger 9, the S end is connected to the second master cylinder 1c of the compressor, and the C end is connected to the first heat exchanger 4, the D end of the second four-way valve 3 is connected to the exhaust end of the compressor 1, the E end is connected to the third heat exchanger 10, the S end is connected to the first master cylinder 1b of the compressor, and the C end is connected to 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 a first main cylinder 1b of a compressor, a first four-way valve 2, a first heat exchanger 4, a first throttling device 5, a flash 6, a second throttling device 7, a second heat exchanger 9 and an auxiliary piping system; the second refrigerant circuit is composed of a second main cylinder 1c of a compressor, a second four-way valve 3, a first heat exchanger 4, a first throttling device 5, a flash 6, a second throttling device 7, a third throttling device 8, a third heat exchanger 10 and an auxiliary piping system; the third refrigerant circuit is composed of a parallel air supply cylinder 1a of a compressor, a first four-way valve 2, a first heat exchanger 4, a first throttling device 5, a flash 6 and an auxiliary piping system.

[0045] The system working process is as follows: the slide valves of the first four-way valve 2 and the second four-way valve 3 move to the left, the E end and the S end are connected, the D end and the C end are connected, the first throttling device 5, the second throttling device 7 and the third throttling device 8 are opened and the opening is controlled according to logic, the high-temperature and high-pressure refrigerant gas discharged from the first main cylinder 1b of the compressor and the high-temperature and high-pressure refrigerant gas discharged from the second main cylinder 1c of the compressor and the parallel supplementary cylinder 1a are mixed and then divided and pass through the first four-way valve 2 and the second four-way valve 3 respectively, and then merge again and enter the first heat exchanger 4. After the refrigerant is cooled and condensed, it passes through the first throttling device 5 to be throttled to an intermediate pressure state and enters the flasher 6, where the gas and liquid are separated. It is saturated or nearly saturated gas and liquid, wherein the saturated / nearly saturated gas enters the compressor parallel air supply cylinder 1a from the air supply 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 of which enters the second heat exchanger 9, where it absorbs the heat in the indoor air and evaporates, and then passes through the first four-way valve 2 and enters the compressor 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 the heat in the indoor air and evaporates, and then passes through the second four-way valve 3 and enters the compressor 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) systems, the present invention proposes a control method and a control device for the air-conditioning system.

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

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

[0049] Step S110, when the air conditioning system is in cooling operation, it is determined 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, the external fan speed and / or the internal fan speed of the air conditioning system are determined according to the outdoor ambient temperature, the indoor ambient temperature and the indoor set temperature, and the initial openings of the first throttling device, the second throttling device and the third throttling device are determined; the operation of the air conditioning system is controlled according to the determined compressor frequency of the air conditioning system, the external fan speed and / or the internal fan speed and the determined initial openings of the first throttling device, the second throttling device and the third throttling device. During the operation of the air conditioning system, the openings 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.

[0051] The compressor frequency, outdoor fan speed and / or indoor fan speed of the air conditioning system are determined according to the outdoor ambient temperature, indoor ambient temperature and set temperature according to the preset values ​​in the startup stage. If the current operation mode of the air conditioner is the cooling mode, the initial openings of the first throttling device, the second throttling device and the third throttling device are determined according to the compressor frequency, the indoor ambient temperature and the outdoor ambient temperature, wherein the initial openings of the first throttling device, the second throttling device and the third throttling device corresponding to different compressor frequencies, indoor ambient temperatures and outdoor ambient temperatures can be determined in advance through experiments.

[0052] The first throttling device, the second throttling device, and the third throttling device may be specifically an electronic expansion valve. When the air conditioner receives a power-on command, the compressor frequency, the outdoor fan speed, and / or the indoor fan speed are operated according to the preset values ​​in the power-on stage based on the indoor and outdoor ambient temperatures detected by the indoor and outdoor ambient temperature sensing packages and the user set temperature, and the openings of the outdoor electronic expansion valve (the first electronic expansion valve and the second electronic expansion valve) and the indoor electronic expansion valve (the third electronic expansion valve) are calculated based on the temperature detected by the temperature sensing package.

[0053] Preferably, after the air conditioning system is turned on for a preset time, it is determined whether the temperature difference between the indoor ambient temperature and the set temperature is greater than or equal to a preset temperature difference threshold. Specifically, after the air conditioning system is turned on for a first preset time T1, it is determined whether the indoor ambient temperature t 内环 With the set temperature t 设 Is the temperature difference greater than or equal to the preset temperature difference threshold a, that is, whether t 内环 -t 设 ≥a. The first preset time T1 has a value range of 2-10 minutes. The value range of the preset temperature difference threshold a includes: 0-5°C, preferably 2°C. Indoor environment temperature t 内环 It can be collected by the ambient temperature sensor installed in the indoor unit of the air conditioner; set the temperature t 设 Can be set by the user.

[0054] Step S120: If it is determined that the temperature difference is less than a preset temperature difference threshold, the predicted noise of the third throttling device is determined according to the middle temperature of the second heat exchanger flow path and the middle temperature of the third heat exchanger flow path.

[0055] That is, if t is not satisfied 内环 -t 设 ≥a, the predicted noise of the third throttling device is determined according to the middle temperature of the second heat exchanger flow path and the middle temperature of the third heat exchanger flow path. The middle temperature of the second and third heat exchanger flow paths t e_h ,t e_l, which can be collected by the temperature sensing packages arranged in the middle of the second and third heat exchanger flow paths; the exhaust temperature t dis It can be collected by the temperature sensing package arranged on the compressor exhaust pipe; the compressor frequency f can be detected by the system.

[0056] Figure 3 The flowchart of a specific implementation of the step of determining the predicted noise of the third throttling device according to the middle temperature of the second heat exchanger flow path and the middle temperature of the third heat exchanger flow path is shown. Figure 3 As shown, step S120 includes step S121, step S122 and step S123.

[0057] Step S121, calculating the maximum mass flow rate in the third throttling device according to the middle temperature of the second heat exchanger flow path and the middle temperature of the third heat exchanger flow path.

[0058] Specifically, the front-to-back pressure difference of the third throttling device and the saturated liquid density at the inlet of the third throttling device are calculated according to the middle temperature of the second heat exchanger flow path and the middle temperature of the third heat exchanger flow path, and the maximum mass flow rate in the third throttling device is calculated according to the front-to-back pressure difference of the third throttling device and the saturated liquid density at the inlet of the third throttling device.

[0059] The temperature of the middle part of the second heat exchanger flow path t e_h , specifically, the middle temperature of the second heat exchanger flow path; the middle temperature of the third heat exchanger flow path t e_l , specifically, the middle temperature of the third heat exchanger flow path; the middle temperature of the second and third heat exchanger flow paths t e_h ,t e_l , which can be collected by the temperature sensing packages arranged 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 the physical properties of the refrigerant (the same fitting coefficients have different values ​​in different fitting correlation equations in the present invention), the middle temperature of the second and third heat exchanger flow paths 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 according to the physical properties of R32 refrigerant combined with the above formula, the pressure difference ΔP before and after the third throttling device (third electronic expansion valve) can be obtained. r3 =ΔP r3 =509.46*(t e_h 2 -t e_l 2 )+20853*(t e_h -t e_l ).

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

[0064] After calculating the front-rear pressure difference of the third throttling device and the saturated liquid density at the inlet of the third throttling device, the maximum mass flow rate in the third throttling device is calculated according to the front-rear pressure difference of the third throttling device and the saturated liquid density at the inlet of the third throttling device.

[0065] The maximum mass flow rate in the third throttling device G = a*ρ*(ΔP) 0.5 a is the fitting coefficient related to the refrigerant properties (the same fitting coefficient has different values ​​in different fitting correlation equations in the present invention).

[0066] For example, if the refrigerant is R32, then according to the physical properties of R32 refrigerant combined with the above formula, the maximum mass flow rate in the third throttling device G = 0.0283*ρ*(ΔP) 0.5 .

[0067] Step S122, calculating the inlet dryness of the third throttling device according to the middle temperature of the second heat exchanger flow path.

[0068] 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 flow path middle 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.

[0069] The specific enthalpy of the subcooled or saturated refrigerant is h = a*t*t+b*t+c, where a, b, and c are values ​​obtained by fitting from the refrigerant property software. The saturated liquid enthalpy of the second heat exchanger is h 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 according to the physical properties of R32 refrigerant combined with the above formula, the saturated liquid enthalpy of the second heat exchanger h 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] Refrigerant phase change latent heat h = a*t*t+b*t+c, where a, b, c are fitting coefficients related to the physical properties of the refrigerant (the same fitting coefficients have different values ​​in different fitting correlations in the present invention), then the second heat exchanger phase change latent heat h e_h_fg =a*t e_h *t e_h -b*t e_h +c.

[0074] For example, if the refrigerant is R32, the latent heat of phase change of the second heat exchanger h is obtained by fitting the physical 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 of the third throttling device (the third electronic expansion valve) is x3=(h f -h e_h_f ) / h e_h_fg .

[0076] Among them, h fis the flasher outlet temperature, which is calculated by the first heat exchanger outlet temperature, the second heat exchanger flow path middle temperature, the third heat exchanger flow path middle temperature, and the frequency through the fitting formula. Using the fitting correlation formula, we can get: 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, where tc_o is the outlet temperature of the first heat exchanger, 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, and the values ​​of the same (identified) fitting coefficients in different fitting correlations in the present invention are different, and f is the compressor frequency. High-temperature evaporation temperature (high-temperature suction saturation temperature) t suc_h_sat = Temperature of the middle part of the second heat exchanger flow path t e_h - High temperature suction line saturation temperature drop dt sat_suc_h , high temperature suction line saturation temperature drop dt sat_suc_h = f(f); the high temperature suction pipeline saturation temperature drop dt sat_suc_h Related to the compressor frequency f, for example, it can be: dt sat_suc_h =a*f*f+b*f+c, where a, b and c are fitting coefficients. The values ​​of the same (identified) fitting coefficients in different fitting correlation equations in the present invention are different. Low temperature evaporation temperature (low temperature suction saturation temperature) t suc_l_sat = Temperature of the middle part of the third heat exchanger flow path t e_l - Low temperature suction line saturation temperature drop dt sat_suc_l , low temperature suction line saturation temperature drop dt sat_suc_l =f(f); f(f) is obtained by fitting based on experimental data. Saturation temperature drop dt of low temperature suction line sat_suc_l Related to the frequency f of the compressor, for example, it can be: dt sat_suc_l =a*f*f+b*f+c, where a, b and c are fitting coefficients. The values ​​of the same (identified) fitting coefficients in different fitting correlations in the present invention are different. The outlet temperature of the first heat exchanger tc_o, the middle temperature of the flow path of the second heat exchanger t e_h , the temperature in the middle of the third heat exchanger flow path t e_l Obtained through temperature sensing package detection.

[0077] Step S123, 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.

[0078] The third throttling device (the third electronic expansion valve) Z = a*G2 +b*G+c*x+d, where a is in the range of -6.3*10 -7 ~0, the preferred value is -2.38*10 -7 , b value range is 3.3*10 -3 ~8.5*10 -3 , the preferred value is 5.86*10 -3 , c ranges from 0 to 250, with a preferred value of 25.63, and d ranges from -15 to 17, with a preferred value of 0.873.

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

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

[0081] The first opening threshold is the lower opening limit of the first throttling device, and the second opening threshold is the upper opening limit of the second throttling device. If it is determined that the predicted noise is less than the preset threshold, return to the step of determining whether the temperature difference between the indoor ambient temperature and the set temperature is greater than or equal to the preset temperature difference threshold.

[0082] For example, when the third electronic expansion valve predicts that the noise Z satisfies Z<b (preset threshold), it is considered that the noise is small and will not affect the indoor comfort. The control parameters remain unchanged, and the system returns to determine whether the temperature difference between the indoor ambient temperature and the set temperature is greater than or equal to the preset temperature difference threshold (t 内环 -t 设 ≥a); the value range of b is 25-36dB(A); when Z≥b, it is considered that the noise has affected the indoor comfort, and the opening B1 of the first electronic expansion valve is reduced and the opening B2 of the second electronic expansion valve is increased.

[0083] The above operation reduces the inlet dryness of the third throttling device (third electronic expansion valve) to reduce noise. By reducing the opening of the first throttling device (first electronic expansion valve), the flash liquid temperature decreases, thereby reducing the inlet specific enthalpy of the second throttling device (second electronic expansion valve), and finally reducing the inlet dryness of the third throttling device (third electronic expansion valve). This process requires correspondingly increasing the opening of the second throttling device (second electronic expansion valve) (further reducing the dryness) to compensate for the total pressure drop.

[0084] Furthermore, after controlling the opening of the first throttling device to decrease and controlling 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 when 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 reducing the opening of the first electronic expansion valve and increasing the opening of the second electronic expansion valve according to the control logic, if the opening of the first electronic expansion valve B1≤c (the first preset opening threshold), or the opening of the second electronic expansion valve B2≥d (the second preset opening threshold), then maintain this opening; otherwise, return to judgment t 内环 -t 设 ≥a. The first preset opening threshold c is the lower opening limit of the first electronic expansion valve, and the second preset opening threshold d is the upper opening limit of the second electronic expansion valve.

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

[0087] For example, when the third electronic expansion valve predicts that the noise Z satisfies Z<b (preset threshold), it is considered that the noise is small and will not affect the indoor comfort. The control parameters remain unchanged, and the system returns to determine whether the temperature difference between the indoor ambient temperature and the set temperature is greater than or equal to the preset temperature difference threshold (t 内环 -t 设 ≥a); the value range of b is 25-36dB(A); when Z≥b, it is considered that the noise has affected the indoor comfort, and the speed of the outdoor fan R0 is increased and the opening of the second electronic expansion valve B2 is increased.

[0088] This operation can reduce the inlet dryness of the third electronic expansion valve to reduce noise. The speed of the external fan is increased, the cold outlet temperature is reduced, and the flash liquid temperature is reduced synchronously.

[0089] Furthermore, after controlling the speed of the external fan of the air-conditioning system to increase and controlling the opening of the second throttling device to increase, when the speed of the external fan 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 external fan and the current opening of the second throttling device are maintained.

[0090] After increasing the speed Ro of the external fan and increasing the opening B2 of the second electronic expansion valve according to the control logic, if the second electronic expansion valve opening B2≥d (the second preset opening threshold) or the speed Ro of the external fan≥e is satisfied, the opening is maintained; otherwise, the judgment t is returned. 内环 -t 设 ≥a. The second preset opening threshold d is the upper limit of the opening of the second electronic expansion valve, and e is the upper limit of the speed of the external fan.

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

[0092] In order to clearly illustrate the technical solution of the present invention, the execution process of the control method of the air-conditioning system provided by the present invention is described below with reference to several specific embodiments.

[0093] Figure 4 FIG. 1 is a schematic diagram of a method for controlling an air conditioning system according to a specific embodiment of the present invention. Figure 4 As shown, the air conditioning system is turned on for cooling operation. According to the indoor ambient temperature, outdoor ambient temperature, set temperature, set indoor unit wind speed and electronic expansion valve control algorithm, the system operating parameters and the openings B1, B2 and B3 of the three electronic expansion valves are determined and controlled.

[0094] After running for T1 time, detect the temperature of the inner ring temperature sensor package t 内环 and the set temperature t 设 Compare, if t 内环 -t 设 ≥a, then return to continue control, otherwise, enter the next step; calculate the total value Z of the predicted noise of the third electronic expansion valve according to the system detection parameters. When the total value of the predicted noise of the third electronic expansion valve satisfies Z<b, it is considered that the noise is small and will not affect the indoor comfort. All control parameters remain unchanged, and return to set the temperature of the inner ring temperature sensing package t 内环 With the set temperature t 设 Comparison step; when Z ≥ b, it is considered that the noise has affected the indoor comfort, and the opening of the first electronic expansion valve is reduced and the opening of the second electronic expansion valve is increased to reduce the noise. If the opening of the first electronic expansion valve B1 ≤ c, or the opening of the second electronic expansion valve B2 ≥ d, the current openings of the first and second electronic expansion valves are maintained; otherwise, the inner ring temperature sensing package temperature t is returned to 内环With the set temperature t 设 Compare the steps.

[0095] Figure 5 FIG. 2 is a schematic diagram of another specific embodiment of the method for controlling the air conditioning system provided by the present invention. Figure 5 As shown, the air conditioning system is turned on for cooling operation. According to the indoor ambient temperature, outdoor ambient temperature, set temperature, set indoor unit wind speed and electronic expansion valve control algorithm, the system operating parameters and the openings B1, B2 and B3 of the three electronic expansion valves are determined and controlled.

[0096] After running for T1 time, detect the temperature of the inner ring temperature sensor package t 内环 and the set temperature t 设 Compare, if t 内环 -t 设 ≥a, then return to continue control, otherwise, enter the next step; calculate the total value Z of the predicted noise of the third electronic expansion valve according to the system detection parameters. When the total value of the predicted noise of the third electronic expansion valve satisfies Z<b, it is considered that the noise is small and will not affect the indoor comfort. All control parameters remain unchanged, and return to set the temperature of the inner ring temperature sensing package t 内环 With the set temperature t 设 Comparison steps: When Z ≥ b, it is considered that the noise has affected the indoor comfort, and the speed of the external fan Ro is increased, and the opening of the second electronic expansion valve B2 is increased. If the opening of the second electronic expansion valve B2 ≥ d, or the speed of the external fan Ro ≥ e, the speed of the external fan and the opening of the second electronic expansion valve are maintained; otherwise, the temperature of the inner ring temperature sensor package t is returned to 内环 With the set temperature t 设 Compare the steps.

[0097] Figure 6 FIG. 1 is a structural block diagram of an embodiment of a control device for an air conditioning system provided by the present invention. Figure 6 As shown, the control device 100 of the air conditioning system includes: a judgment unit 110 , a determination unit 120 and an adjustment unit 130 .

[0098] The judgment unit 110 is used to judge whether the temperature difference between the indoor ambient temperature and the set temperature is greater than or equal to a preset temperature difference threshold value when the air-conditioning system is in cooling operation.

[0099] Specifically, after the air conditioning system is turned on for heating, the compressor frequency, the external fan speed and / or the internal fan speed of the air conditioning system are determined according to the outdoor ambient temperature, the indoor ambient temperature and the indoor set temperature, and the initial openings of the first throttling device, the second throttling device and the third throttling device are determined; the operation of the air conditioning system is controlled according to the determined compressor frequency of the air conditioning system, the external fan speed and / or the internal fan speed and the determined initial openings of the first throttling device, the second throttling device and the third throttling device. During the operation of the air conditioning system, the openings 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, outdoor fan speed and / or indoor fan speed of the air conditioning system are determined according to the outdoor ambient temperature, indoor ambient temperature and set temperature according to the preset values ​​in the startup stage. If the current operation mode of the air conditioner is the cooling mode, the initial openings of the first throttling device, the second throttling device and the third throttling device are determined according to the compressor frequency, the indoor ambient temperature and the outdoor ambient temperature, wherein the initial openings of the first throttling device, the second throttling device and the third throttling device corresponding to different compressor frequencies, indoor ambient temperatures and outdoor ambient temperatures can be determined in advance through experiments.

[0101] The first throttling device, the second throttling device, and the third throttling device may be specifically an electronic expansion valve. When the air conditioner receives a power-on command, the compressor frequency, the outdoor fan speed, and / or the indoor fan speed are operated according to the preset values ​​in the power-on stage based on the indoor and outdoor ambient temperatures detected by the indoor and outdoor ambient temperature sensing packages and the user set temperature, and the openings of the outdoor electronic expansion valve (the first electronic expansion valve and the second electronic expansion valve) and the indoor electronic expansion valve (the third electronic expansion valve) are calculated based on the temperature detected by the temperature sensing package.

[0102] Preferably, after the air conditioning system is turned on for a preset time, it is determined whether the temperature difference between the indoor ambient temperature and the set temperature is greater than or equal to a preset temperature difference threshold. Specifically, after the air conditioning system is turned on for a first preset time T1, it is determined whether the indoor ambient temperature t 内环 With the set temperature t 设 Is the temperature difference greater than or equal to the preset temperature difference threshold a, that is, whether t 内环 -t 设 ≥a. The first preset time T1 has a value range of 2-10 minutes. The value range of the preset temperature difference threshold a includes: 0-5°C, preferably 2°C. Indoor environment temperature t 内环 It can be collected by the ambient temperature sensor installed in the indoor unit of the air conditioner; set the temperature t 设 Can be set by the user.

[0103] The determination unit 120 is used to determine the predicted noise of the third throttling device according to the middle temperature of the second heat exchanger flow path and the middle temperature of the third heat exchanger flow path if the determination unit determines that the temperature difference is less than a preset temperature difference threshold.

[0104] That is, if t is not satisfied 内环 -t 设 ≥a, the predicted noise of the third throttling device is determined according to the middle temperature of the second heat exchanger flow path and the middle temperature of the third heat exchanger flow path. The middle temperature of the second and third heat exchanger flow paths t e_h ,t e_l , which can be collected by the temperature sensing packages arranged in the middle of the second and third heat exchanger flow paths; the exhaust temperature t dis It can be collected by the temperature sensing package arranged on the compressor exhaust pipe; the compressor frequency f can be detected by the system.

[0105] In a specific embodiment, the determination unit 120 determines the predicted noise of the third throttling device according to the middle temperature of the second heat exchanger flow path and the middle temperature of the third heat exchanger flow path, including: step S121, step 122 and step S123.

[0106] Step S121, calculating the maximum mass flow rate in the third throttling device according to the middle temperature of the second heat exchanger flow path and the middle temperature of the third heat exchanger flow path.

[0107] Specifically, the front-to-back pressure difference of the third throttling device and the saturated liquid density at the inlet of the third throttling device are calculated according to the middle temperature of the second heat exchanger flow path and the middle temperature of the third heat exchanger flow path, and the maximum mass flow rate in the third throttling device is calculated according to the front-to-back pressure difference of the third throttling device and the saturated liquid density at the inlet of the third throttling device.

[0108] The temperature of the middle part of the second heat exchanger flow path t e_h , specifically, the middle temperature of the second heat exchanger flow path; the middle temperature of the third heat exchanger flow path t e_l , specifically, the middle temperature of the third heat exchanger flow path; the middle temperature of the second and third heat exchanger flow paths t e_h ,t e_l , which can be collected by the temperature sensing packages arranged in the middle of the flow paths of the second and third heat exchangers respectively.

[0109] 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 the physical properties of the refrigerant (the same fitting coefficients have different values ​​in different fitting correlation equations in the present invention), the middle temperature of the second and third heat exchanger flow paths 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:

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

[0111] For example, if the refrigerant is R32, then according to the physical properties of R32 refrigerant combined with the above formula, the pressure difference ΔP before and after the third throttling device (third electronic expansion valve) can be obtained. r3 =ΔP r3 =509.46*(t e_h 2 -t e_l 2 )+20853*(t e_h -t e_l );

[0112] Refrigerant saturated liquid density ρ = a*t*t+b*t+c, where t is the refrigerant temperature, a, b, c are fitting coefficients related to the refrigerant properties (the same fitting coefficients have different values ​​in different fitting correlations in the present invention), then the saturated liquid density ρ at the inlet of the third throttling device (the third electronic expansion valve) is r3 is: r3 =a*t e_h *t e_h -bt e_h +c; For example, if the refrigerant is R32, then according to the physical properties of R32 refrigerant combined with the above formula, the inlet saturated liquid density ρ of the third throttling device (third electronic expansion valve) can be obtained by fitting r3 is: r3 =-0.031*t e_h *t e_h -2.7548t e_h +1051.3;

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

[0114] The maximum mass flow rate in the third throttling device G = a*ρ*(ΔP) 0.5 a is the fitting coefficient related to the refrigerant properties (the same fitting coefficient has different values ​​in different fitting correlation equations in the present invention).

[0115] For example, if the refrigerant is R32, then according to the physical properties of R32 refrigerant combined with the above formula, the maximum mass flow rate in the third throttling device G = 0.0283*ρ*(ΔP) 0.5 .

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

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

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

[0120] For example, if the refrigerant is R32, then according to the physical properties of R32 refrigerant combined with the above formula, the saturated liquid enthalpy of the second heat exchanger h e_h_f for:

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

[0122] Refrigerant phase change latent heat h = a*t*t+b*t+c, where a, b, c are fitting coefficients related to the physical properties of the refrigerant (the same fitting coefficients have different values ​​in different fitting correlations in the present invention), then 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, if the refrigerant is R32, the latent heat of phase change of the second heat exchanger h is obtained by fitting the physical parameters of R32. e_h_fg For: he_h_fg =-0.0181*t e_h *t e_h -1.1988*t e_h +313.22.

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

[0125] Among them, h f is the flasher outlet temperature, which is calculated by the first heat exchanger outlet temperature, the second heat exchanger flow path middle temperature, the third heat exchanger flow path middle temperature, and the frequency through the fitting formula. Using the fitting correlation formula, we can get: 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, where tc_o is the outlet temperature of the first heat exchanger, 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, and the values ​​of the same (identified) fitting coefficients in different fitting correlations in the present invention are different, and f is the compressor frequency. For example, the high-temperature evaporation temperature (high-temperature suction saturation temperature) t suc_h_sat = Temperature of the middle part of the second heat exchanger flow path t e_h - High temperature suction line saturation temperature drop dt sat_suc_h , high temperature suction line saturation temperature drop dt sat_suc_h = f(f); the high temperature suction pipeline saturation temperature drop dt sat_suc_h Related to the compressor frequency f, for example, it can be: dt sat_suc_h =a*f*f+b*f+c, where a, b and c are fitting coefficients. The values ​​of the same (identified) fitting coefficients in different fitting correlation equations in the present invention are different. Low temperature evaporation temperature (low temperature suction saturation temperature) t suc_l_sat = Temperature of the middle part of the third heat exchanger flow path t e_l - Low temperature suction line saturation temperature drop dt sat_suc_l , low temperature suction line saturation temperature drop dt sat_suc_l =f(f); f(f) is obtained by fitting based on experimental data. Saturation temperature drop dt of low temperature suction line sat_suc_l Related to the frequency f of the compressor, for example, it can be: dt sat_suc_l=a*f*f+b*f+c, where a, b and c are fitting coefficients. The values ​​of the same (identified) fitting coefficients in different fitting correlations in the present invention are different. The outlet temperature of the first heat exchanger tc_o, the middle temperature of the flow path of the second heat exchanger t e_h , the temperature in the middle of the third heat exchanger flow path t e_l Obtained through temperature sensing package detection.

[0126] Step S123, 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.

[0127] The third throttling device (the third electronic expansion valve) Z = a*G 2 +b*G+c*x+d, where a is in the range of -6.3*10 -7 ~0, the preferred value is -2.38*10 -7 , b value range is 3.3*10 -3 ~8.5*10 -3 , the preferred value is 5.86*10 -3 , c ranges from 0 to 250, with a preferred value of 25.63, and d ranges from -15 to 17, with a preferred value of 0.873.

[0128] The adjustment unit 130 is used to adjust the opening of the first throttling device and the second throttling device according to the predicted noise determined by the determination unit, or adjust the external fan speed of the air-conditioning system and the opening of the second throttling device.

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

[0130] The first opening threshold is the lower opening limit of the first throttling device, and the second opening threshold is the upper opening limit of the second throttling device. If it is determined that the predicted noise is less than the preset threshold, return to the step of determining whether the temperature difference between the indoor ambient temperature and the set temperature is greater than or equal to the preset temperature difference threshold.

[0131] For example, when the third electronic expansion valve predicts that the noise Z satisfies Z<b (preset threshold), it is considered that the noise is small and will not affect the indoor comfort. The control parameters remain unchanged, and the system returns to determine whether the temperature difference between the indoor ambient temperature and the set temperature is greater than or equal to the preset temperature difference threshold (t 内环 -t设 ≥a); the value range of b is 25-36dB(A); when Z≥b, it is considered that the noise has affected the indoor comfort, and the opening B1 of the first electronic expansion valve is reduced and the opening B2 of the second electronic expansion valve is increased.

[0132] The above operation reduces the inlet dryness of the third throttling device (third electronic expansion valve) to reduce noise. By reducing the opening of the first throttling device (first electronic expansion valve), the flash liquid temperature decreases, thereby reducing the inlet specific enthalpy of the second throttling device (second electronic expansion valve), and finally reducing the inlet dryness of the third throttling device (third electronic expansion valve). This process requires correspondingly increasing the opening of the second throttling device (second electronic expansion valve) (further reducing the dryness) to compensate for the total pressure drop.

[0133] Furthermore, the adjustment unit 130 is also used to: after controlling the opening of the first throttling device to decrease and controlling 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 when the opening of the second throttling device is greater than or equal to a second preset opening threshold, maintain the current opening of the first throttling device and the second throttling device.

[0134] After reducing the opening of the first electronic expansion valve and increasing the opening of the second electronic expansion valve according to the control logic, if the opening of the first electronic expansion valve B1≤c (the first preset opening threshold), or the opening of the second electronic expansion valve B2≥d (the second preset opening threshold), then maintain this opening; otherwise, return to judgment t 内环 -t 设 ≥a. The first preset opening threshold c is the lower opening limit of the first electronic expansion valve, and the second preset opening threshold d is the upper opening limit of the second electronic expansion valve.

[0135] In another specific implementation, the adjustment unit 130 adjusts the speed of the external fan of the air conditioning system and the opening of the second throttling device according to the predicted noise to reduce the noise of the third throttling device. Specifically, it is determined whether the predicted noise of the third throttling device is greater than or equal to a preset threshold; if it is determined that the predicted noise is greater than or equal to the preset threshold, the speed of the external fan of the air conditioning system is controlled to increase, and the opening of the second throttling device is controlled to increase.

[0136] For example, when the third electronic expansion valve predicts that the noise Z satisfies Z<b (preset threshold), it is considered that the noise is small and will not affect the indoor comfort. The control parameters remain unchanged, and the system returns to determine whether the temperature difference between the indoor ambient temperature and the set temperature is greater than or equal to the preset temperature difference threshold (t 内环 -t 设≥a); the value range of b is 25-36dB(A); when Z≥b, it is considered that the noise has affected the indoor comfort, and the speed of the outdoor fan R0 is increased and the opening of the second electronic expansion valve B2 is increased.

[0137] This operation can reduce the inlet dryness of the third electronic expansion valve to reduce noise. The speed of the external fan is increased, the cold outlet temperature is reduced, and the flash liquid temperature is reduced synchronously.

[0138] Furthermore, the adjustment unit 130 is also used to: after controlling the speed of the external fan of the air-conditioning system to increase and controlling the opening of the second throttling device to increase, when the speed of the external fan 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, maintain the current speed of the external fan and the current opening of the second throttling device.

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

[0140] The present invention also provides a storage medium corresponding to the control method of the air-conditioning system, on which a computer program is stored, and when the computer program is executed by a processor, the steps of any of the aforementioned methods are implemented.

[0141] The present invention also provides an air-conditioning system corresponding to the control method of the 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 aforementioned methods when executing the computer program.

[0142] The present invention also provides an air-conditioning system corresponding to the control device of the air-conditioning system, comprising any of the control devices of the air-conditioning systems described above.

[0143] The present invention also provides a computer program product corresponding to the control method of the air-conditioning system, comprising a computer program, and when the computer program is executed by a processor, the steps of any of the aforementioned methods are implemented.

[0144] Accordingly, the solution provided by the present invention addresses the problem of flow noise of the electronic expansion valve on the indoor unit side of the air-conditioning system. While taking into account the energy efficiency, it can reduce the flow noise of the electronic expansion valve and improve indoor comfort.

[0145] According to the technical solution of the present invention, the potential relationship between the system state parameters and the refrigerant physical properties is empirically fitted, and the maximum mass flow rate and inlet dryness in the indoor electronic expansion valve are accurately calculated, so as to calculate the predicted noise of the electronic expansion valve on the indoor unit side, and then reduce the noise of the electronic expansion valve on the indoor unit side by controlling the opening of the throttling device on the outdoor unit side or the speed of the outdoor fan.

[0146] According to the technical solution of the present invention, the total value of the electronic expansion valve noise is associated with its main influencing parameters, namely, the maximum mass flow rate in the valve and the valve inlet dryness. When the total value of the fitting prediction noise 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 electronic expansion valve inlet dryness.

[0147] The functions described herein may be implemented in hardware, software executed by a processor, firmware, or any combination thereof. If implemented in software executed by a processor, the functions may be stored as one or more instructions or codes on a computer-readable medium or transmitted via a computer-readable medium. Other examples and implementations are within the scope and spirit of the present invention and the appended claims. For example, due to the nature of software, the functions described above may be implemented using software executed by a processor, hardware, firmware, hard wiring, or a combination of any of these. In addition, each functional unit may be integrated into a processing unit, each unit may exist physically separately, or two or more units may be integrated into one unit.

[0148] In the several embodiments provided in this application, it should be understood that the disclosed technical content can be implemented in other ways. Among them, the device embodiments described above are only schematic. For example, the division of the units can be a logical function division. There may be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of units or modules, which can be electrical or other forms.

[0149] The units described as separate components may or may not be physically separated, and the components of the control device may or may not be physical units, that is, they may be located in one place or distributed in multiple units. Some or all of the units may be selected according to actual needs to achieve the purpose of the present embodiment.

[0150] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the relevant technology or all or part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including a number of instructions to enable a computer device (which can be a personal computer, a server or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present invention. The aforementioned storage medium includes: U disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), mobile hard disk, disk or optical disk and other media that can store program codes.

[0151] The above description is only an embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent substitution, improvement, etc. made within the spirit and principle of the present invention shall be included in the scope of the claims of the present invention.

Claims

1. A control method for an air conditioning system, characterized in that: 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, wherein the gas outlet end of the flasher is connected to the gas supply end of the compressor, the inlet end of the flasher is connected to 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 in parallel and connected to the flasher through the second throttling device, and the third throttling device is arranged on the pipeline in which the third heat exchanger is connected in parallel with the second heat exchanger; The control method comprises: When the air conditioning system is in cooling operation, 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 it is determined that the temperature difference is less than a preset temperature difference threshold, the predicted noise of the third throttling device is determined according to the middle temperature of the second heat exchanger flow path and the middle temperature of the third heat exchanger flow path; According to the predicted noise, the openings of the first throttling device and the second throttling device are adjusted, or the speed of the external fan of the air-conditioning system and the opening of the second throttling device are adjusted.

2. The method according to claim 1, characterized in that Determining the predicted noise of the third throttling device according to the middle temperature of the second heat exchanger flow path and the middle temperature of the third heat exchanger flow path includes: Calculating the maximum mass flow rate in the third throttling device according to the middle temperature of the second heat exchanger flow path and the middle temperature of the third heat exchanger flow path; Calculating the inlet dryness of the third throttling device according to the middle 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 inlet dryness of the third throttling device.

3. The method according to claim 2, characterized in that Calculating the maximum mass flow rate in the third throttling device according to the middle temperature of the second heat exchanger flow path and the middle temperature of the third heat exchanger flow path, comprising: Calculating the front-rear pressure difference of the third throttling device and the saturated liquid density at the inlet of the third throttling device according to the middle temperature of the second heat exchanger flow path and the middle temperature of the third heat exchanger flow path; 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 saturated liquid density at the inlet of the third throttling device; and / or, Calculating the inlet dryness of the third throttling device according to the middle temperature of the second heat exchanger flow path includes: Calculating the saturated liquid enthalpy of the second heat exchanger and the phase change latent heat of the second heat exchanger according to the middle temperature of the second heat exchanger flow path; The inlet dryness of the third throttling device is calculated according to the saturated liquid enthalpy of the second heat exchanger and the latent heat of phase change of the second heat exchanger.

4. The method according to any one of claims 1 to 3, characterized in that: According to the predicted noise, adjusting the opening of the first throttling device and the second throttling device comprises: determining whether the predicted noise of the third throttling device is greater than or equal to a preset threshold; If it is determined that the predicted noise is greater than or equal to the preset threshold, the opening of the first throttling device is controlled to decrease, and the opening of the second throttling device is controlled to increase.

5. The method according to claim 4, characterized in that Also includes: After controlling the opening of the first throttling device to decrease and controlling the opening of the second throttling device to increase, when the opening of the first throttling device is less than or equal to the first preset opening threshold, or when the opening of the second throttling device is greater than or equal to the second preset opening threshold, maintain the current openings of the first throttling device and the second throttling device.

6. The method according to any one of claims 1 to 3, characterized in that: According to the predicted noise, adjusting the speed of the external fan of the air conditioning system and the opening of the second throttling device includes: Determine whether the predicted noise of the third throttling device is greater than or equal to a preset threshold; if it is determined that the predicted noise is greater than or equal to the preset threshold, control the speed of the external fan of the air-conditioning system to increase, and control the opening of the second throttling device to increase.

7. The method according to claim 6, characterized in that Also includes: After controlling the speed of the external fan of the air-conditioning system to increase and controlling the opening of the second throttling device to increase, when the speed of the external fan 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, maintain the current speed of the external fan and the current opening of the second throttling device.

8. A control device for an air conditioning system, characterized in that: 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, wherein the gas outlet end of the flasher is connected to the gas supply end of the compressor, the inlet end of the flasher is connected to 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 in parallel and connected to the flasher through the second throttling device, and the third throttling device is arranged on the pipeline in which the third heat exchanger is connected in parallel with the second heat exchanger; The control device comprises: A judgment unit, used to judge whether the temperature difference between the indoor ambient temperature and the set temperature is greater than or equal to a preset temperature difference threshold when the air conditioning system is in cooling operation; a determination unit, configured to determine the predicted noise of the third throttling device according to the middle temperature of the second heat exchanger flow path and the middle temperature of the third heat exchanger flow path if the determination unit determines that the temperature difference is less than a preset temperature difference threshold; An adjustment unit is used to adjust the opening of the first throttling device and the second throttling device according to the predicted noise determined by the determination unit, or to adjust the external fan speed of the air-conditioning system and the opening of the second throttling device.

9. A storage medium, characterized in that: A computer program is stored thereon, and when the program is executed by a processor, the steps of any method described in claims 1-7 are implemented.

10. An air conditioning system, characterized in that: The method comprises 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 method described in claims 1 to 7 when executing the program, or comprises the control device described in claim 8.

11. A computer program product, characterized in that The invention comprises a computer program, which implements the steps of any one of the methods of claims 1 to 7 when being executed by a processor.

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