Heat pump air conditioning systems and their control methods, devices, storage media and program products

Abstract

This invention discloses a heat pump air conditioning system and its control method, device, storage medium, and computer program product. The method includes: after the heat pump air conditioning system has been running in cooling mode for a set time, if it is determined that the difference between the indoor ambient temperature and the set temperature is less than a preset temperature threshold, then the predicted noise of the third electronic expansion valve is determined based on the pipe temperatures of the first indoor heat exchanger, the pipe temperatures of the second indoor heat exchanger, and the outlet saturated liquid enthalpy of the flash evaporator; based on the predicted noise of the third electronic expansion valve and the exhaust superheat of the compressor, the compressor frequency is adjusted, or the opening degree of the second and third electronic expansion valves is adjusted. This solution reduces the mass flow rate of the indoor unit-side electronic expansion valves by adjusting the compressor frequency or adjusting the opening degree of the indoor unit-side electronic expansion valves and their adjacent electronic expansion valves (i.e., the third and second electronic expansion valves), thereby reducing noise and improving comfort.

Description

Technical Field

[0001] This invention belongs to the technical field of heat pump air conditioning systems, specifically relating to a control method, device, storage medium, and computer program product for a heat pump air conditioning system, and particularly to a control method, device, storage medium, and computer program product for reducing the flow noise of an electronic expansion valve in a heat pump air conditioning system. Background Technology

[0002] In a three-pipe dual-temperature parallel compression system, the indoor unit uses an electronic expansion valve to control the temperature difference of the dual-temperature evaporation and the distribution of refrigerant flow. Since the refrigerant before the electronic expansion valve is in a two-phase state, it causes two-phase flow noise, which will have a certain impact on the user's comfort experience.

[0003] The above content is only used to help understand the technical solution of the present invention and does not represent an admission that the above content is prior art. Summary of the Invention

[0004] The purpose of this invention is to provide a control method, device, system, storage medium, and computer program product for a heat pump air conditioning system. This addresses the problem in a three-pipe, dual-temperature parallel compression system of a heat pump air conditioning system where the refrigerant before the indoor unit's electronic expansion valve is in a two-phase state, generating two-phase flow noise that affects user comfort. The invention aims to reduce noise and improve user comfort by predicting the noise of the indoor unit's electronic expansion valve and adjusting the compressor frequency or the opening of the indoor unit's electronic expansion valve and its adjacent electronic expansion valves (i.e., the third and second electronic expansion valves) based on the compressor's exhaust superheat.

[0005] This invention provides a control method for a heat pump air conditioning system. The heat pump air conditioning system includes a compressor, an outdoor heat exchanger, two indoor heat exchangers, and a flash evaporator. The two indoor heat exchangers include a first indoor heat exchanger and a second indoor heat exchanger. A first electronic expansion valve is provided between the outdoor heat exchanger and the flash evaporator. A second electronic expansion valve is provided between the flash evaporator and the two indoor heat exchangers. A third electronic expansion valve is provided between the second electronic expansion valve and the second indoor heat exchanger, and on the pipeline where the second indoor heat exchanger is located. The control method for the heat pump air conditioning system includes: after the heat pump air conditioning system is turned on in cooling mode, controlling the opening degrees of the first electronic expansion valve, the second electronic expansion valve, and the third electronic expansion valve to their respective set values; after the heat pump air conditioning system has been running in cooling mode for a set time, acquiring the indoor ambient temperature of the heat pump air conditioning system at a set cycle, and acquiring the... The system obtains the pipe temperature of the first indoor heat exchanger, the pipe temperature of the second indoor heat exchanger, the discharge superheat of the compressor, and the outlet saturated liquid enthalpy of the flash evaporator; it determines whether the difference between the indoor ambient temperature and the set temperature of the heat pump air conditioning system is greater than or equal to a preset temperature threshold; if the difference is greater than or equal to the preset temperature threshold, the system maintains its current operation; if the difference is less than the preset temperature threshold, the system determines the predicted noise of the third electronic expansion valve based on the pipe temperatures of the first and second indoor heat exchangers and the outlet saturated liquid enthalpy of the flash evaporator; and adjusts the frequency of the compressor or the opening of the second and third electronic expansion valves based on the predicted noise of the third electronic expansion valve and the discharge superheat of the compressor.

[0006] In some embodiments, determining the predicted noise of the third electronic expansion valve based on the tube temperatures of the first indoor heat exchanger, the second indoor heat exchanger, and the outlet saturated liquid enthalpy of the flash evaporator includes: determining the inlet and outlet pressure difference of the third electronic expansion valve based on the tube temperatures of the first and second indoor heat exchangers; determining the inlet saturated liquid density of the third electronic expansion valve based on the tube temperature of the first indoor heat exchanger; and determining the predicted noise of the third electronic expansion valve based on the inlet and outlet pressure difference and the inlet saturated liquid density of the third electronic expansion valve. The mass flow rate of the third electronic expansion valve; the saturated liquid enthalpy of the first indoor heat exchanger is determined based on the tube temperature of the first indoor heat exchanger; the latent heat of phase change of the first indoor heat exchanger is determined based on the tube temperature of the first indoor heat exchanger; the inlet dryness fraction of the third electronic expansion valve is determined based on the outlet saturated liquid enthalpy of the flash evaporator, the saturated liquid enthalpy of the first indoor heat exchanger, and the latent heat of phase change of the first indoor heat exchanger; and the predicted noise of the third electronic expansion valve is determined based on the mass flow rate of the third electronic expansion valve and the inlet dryness fraction of the third electronic expansion valve.

[0007] In some embodiments, determining the inlet and outlet pressure difference of the third electronic expansion valve based on the pipe temperatures of the first and second indoor heat exchangers includes: determining the difference between the square of the pipe temperature of the first and second indoor heat exchangers as a first difference; determining the difference between the pipe temperatures of the first and second indoor heat exchangers as a second difference; and determining the sum of a first preset calculation coefficient multiple of the first difference and a second preset calculation coefficient multiple of the second difference as the inlet and outlet pressure difference of the third electronic expansion valve; and / or, determining the inlet saturation pressure of the third electronic expansion valve based on the pipe temperature of the first indoor heat exchanger. The liquid density is determined by: multiplying the square of the tube temperature of the first indoor heat exchanger by a third preset calculation factor, a fourth preset calculation factor, and a fifth preset calculation factor, to determine the inlet saturated liquid density of the third electronic expansion valve; and / or, determining the mass flow rate of the third electronic expansion valve based on the inlet-outlet pressure difference and the inlet saturated liquid density of the third electronic expansion valve, including: multiplying the half-power of the inlet-outlet pressure difference of the third electronic expansion valve by the inlet saturated liquid density of the third electronic expansion valve and a sixth preset calculation factor, to determine the mass flow rate of the third electronic expansion valve.

[0008] In some embodiments, determining the saturated liquid enthalpy of the first indoor heat exchanger based on its tube temperature includes: determining the saturated liquid enthalpy of the first indoor heat exchanger as the product of the square of the tube temperature of the first indoor heat exchanger and a seventh preset calculation coefficient, the product of the tube temperature of the first indoor heat exchanger and an eighth preset calculation coefficient, and the sum of a ninth preset calculation coefficient; and / or, determining the latent heat of phase change of the first indoor heat exchanger based on its tube temperature includes: determining the latent heat of phase change of the first indoor heat exchanger as the product of the square of the tube temperature of the first indoor heat exchanger and a tenth preset calculation coefficient, the product of the tube temperature of the first indoor heat exchanger and an eleventh preset calculation coefficient, and the sum of a twelfth preset calculation coefficient; and / or, determining the latent heat of phase change of the first indoor heat exchanger based on the outlet saturated liquid enthalpy of the flash evaporator and the first indoor heat exchanger's... The inlet dryness of the third electronic expansion valve is determined based on the saturated liquid enthalpy of the heat exchanger and the latent heat of phase change of the first indoor heat exchanger. This includes: determining the inlet dryness of the third electronic expansion valve as the ratio of the difference between the outlet saturated liquid enthalpy of the flash evaporator and the saturated liquid enthalpy of the first indoor heat exchanger to the latent heat of phase change of the first indoor heat exchanger; and / or, the predicted noise of the third electronic expansion valve is determined based on the mass flow rate of the third electronic expansion valve and the inlet dryness of the third electronic expansion valve. This includes: determining the predicted noise of the third electronic expansion valve as the sum of the thirteenth preset calculation factor multiple of the square of the mass flow rate of the third electronic expansion valve, the fourteenth preset calculation factor multiple of the mass flow rate of the third electronic expansion valve, the fifteenth preset calculation factor multiple of the inlet dryness of the third electronic expansion valve, and the sixteenth preset calculation factor.

[0009] In some embodiments, adjusting the frequency of the compressor, or adjusting the opening degree of the second and third electronic expansion valves, based on the predicted noise of the third electronic expansion valve and the discharge superheat of the compressor, includes: determining whether the predicted noise of the third electronic expansion valve is greater than or equal to a preset noise threshold; if the predicted noise of the third electronic expansion valve is determined to be less than the preset noise threshold, controlling the heat pump air conditioning system to maintain its current operation; if the predicted noise of the third electronic expansion valve is determined to be greater than or equal to the preset noise threshold, then adjusting the frequency of the compressor, or adjusting the opening degree of the second and third electronic expansion valves, based on the discharge superheat of the compressor.

[0010] In some embodiments, adjusting the frequency of the compressor, or adjusting the opening of the second electronic expansion valve and the third electronic expansion valve, based on the compressor's exhaust superheat, includes: determining whether the compressor's exhaust superheat is greater than or equal to a preset superheat threshold; if the compressor's exhaust superheat is determined to be greater than or equal to the preset superheat threshold, then controlling the compressor's frequency to decrease by a set frequency based on the current value, and then returning to the previous state to re-determine whether the difference between the indoor ambient temperature and the set temperature of the heat pump air conditioning system is greater than or equal to a preset temperature threshold; if the compressor's exhaust superheat is determined to be less than the preset superheat threshold, then controlling the opening of the second electronic expansion valve to decrease by a first set opening based on the current value, and controlling the opening of the third electronic expansion valve to decrease by a second set opening based on the current value, and then returning to the previous state to re-determine whether the difference between the indoor ambient temperature and the set temperature of the heat pump air conditioning system is greater than or equal to a preset temperature threshold.

[0011] In conjunction with the above method, another aspect of the present invention provides a control device for a heat pump air conditioning system. The heat pump air conditioning system includes a compressor, an outdoor heat exchanger, two indoor heat exchangers, and a flash evaporator. The two indoor heat exchangers include a first indoor heat exchanger and a second indoor heat exchanger. A first electronic expansion valve is disposed between the outdoor heat exchanger and the flash evaporator. A second electronic expansion valve is disposed between the flash evaporator and the two indoor heat exchangers. A third electronic expansion valve is disposed between the second electronic expansion valve and the second indoor heat exchanger, and on the pipeline where the second indoor heat exchanger is located. The control device for the heat pump air conditioning system includes: a control unit configured to, after the heat pump air conditioning system is turned on in cooling mode, control the opening degrees of the first electronic expansion valve, the second electronic expansion valve, and the third electronic expansion valve to be their respective set values; and an acquisition unit configured to, after the heat pump air conditioning system has been running in cooling mode for a set time, acquire the indoor ambient temperature of the heat pump air conditioning system and acquire the temperature of the first indoor heat exchanger at a set cycle. The control unit is configured to obtain the pipe temperature of the second indoor heat exchanger, the exhaust superheat of the compressor, and the outlet saturated liquid enthalpy of the flash evaporator; the control unit is further configured to determine whether the difference between the indoor ambient temperature of the heat pump air conditioning system and the set temperature is greater than or equal to a preset temperature threshold; the control unit is further configured to control the heat pump air conditioning system to maintain its current operation if the difference between the indoor ambient temperature of the heat pump air conditioning system and the set temperature is greater than or equal to the preset temperature threshold; the control unit is further configured to determine the predicted noise of the third electronic expansion valve based on the pipe temperature of the first indoor heat exchanger, the pipe temperature of the second indoor heat exchanger, and the outlet saturated liquid enthalpy of the flash evaporator if the difference between the indoor ambient temperature of the heat pump air conditioning system and the set temperature is less than the preset temperature threshold; the control unit is further configured to adjust the frequency of the compressor, or adjust the opening degree of the second electronic expansion valve and the opening degree of the third electronic expansion valve based on the predicted noise of the third electronic expansion valve and the exhaust superheat of the compressor.

[0012] In some embodiments, the control unit determines the predicted noise of the third electronic expansion valve based on the tube temperatures of the first indoor heat exchanger, the second indoor heat exchanger, and the outlet saturated liquid enthalpy of the flash evaporator, including: determining the inlet and outlet pressure difference of the third electronic expansion valve based on the tube temperatures of the first and second indoor heat exchangers; determining the inlet saturated liquid density of the third electronic expansion valve based on the tube temperature of the first indoor heat exchanger; and determining the inlet and outlet pressure difference of the third electronic expansion valve and the inlet saturated liquid density of the third electronic expansion valve. The following steps are taken: determining the mass flow rate of the third electronic expansion valve; determining the saturated liquid enthalpy of the first indoor heat exchanger based on its tube temperature; determining the latent heat of phase change of the first indoor heat exchanger based on its tube temperature; determining the inlet dryness fraction of the third electronic expansion valve based on the outlet saturated liquid enthalpy of the flash evaporator, the saturated liquid enthalpy of the first indoor heat exchanger, and the latent heat of phase change of the first indoor heat exchanger; and determining the predicted noise of the third electronic expansion valve based on its mass flow rate and inlet dryness fraction.

[0013] In some embodiments, the control unit determines the inlet and outlet pressure difference of the third electronic expansion valve based on the pipe temperatures of the first and second indoor heat exchangers, including: determining the difference between the square of the pipe temperature of the first and second indoor heat exchangers as a first difference, determining the difference between the pipe temperatures of the first and second indoor heat exchangers as a second difference, and determining the sum of a first preset calculation coefficient multiple of the first difference and a second preset calculation coefficient multiple of the second difference as the inlet and outlet pressure difference of the third electronic expansion valve; and / or, the control unit determines the pressure difference of the third electronic expansion valve based on the pipe temperature of the first indoor heat exchanger. The inlet saturated liquid density includes: determining the inlet saturated liquid density of the third electronic expansion valve by summing the square of the tube temperature of the first indoor heat exchanger (multiplied by a third preset calculation factor), the tube temperature of the first indoor heat exchanger (multiplied by a fourth preset calculation factor), and a fifth preset calculation factor; and / or, the control unit determines the mass flow rate of the third electronic expansion valve based on the inlet-outlet pressure difference of the third electronic expansion valve and the inlet saturated liquid density of the third electronic expansion valve, including: determining the mass flow rate of the third electronic expansion valve by multiplying the half-power of the inlet-outlet pressure difference of the third electronic expansion valve by the inlet saturated liquid density of the third electronic expansion valve and a sixth preset calculation factor.

[0014] In some embodiments, the control unit determines the saturated liquid enthalpy of the first indoor heat exchanger based on the tube temperature of the first indoor heat exchanger by: multiplying the square of the tube temperature of the first indoor heat exchanger by a seventh preset calculation coefficient, multiplying the tube temperature of the first indoor heat exchanger by an eighth preset calculation coefficient, and summing the ninth preset calculation coefficient, as the saturated liquid enthalpy of the first indoor heat exchanger; and / or, the control unit determines the latent heat of phase change of the first indoor heat exchanger based on the tube temperature of the first indoor heat exchanger by: multiplying the square of the tube temperature of the first indoor heat exchanger by a tenth preset calculation coefficient, multiplying the tube temperature of the first indoor heat exchanger by an eleventh preset calculation coefficient, and summing the twelfth preset calculation coefficient, as the latent heat of phase change of the first indoor heat exchanger; and / or, the control unit determines the saturated liquid enthalpy of the flash evaporator based on the outlet saturated liquid enthalpy of the flash evaporator. The control unit determines the inlet dryness of the third electronic expansion valve based on the saturated liquid enthalpy of the first indoor heat exchanger and the latent heat of phase change of the first indoor heat exchanger. This includes: determining the ratio of the difference between the outlet saturated liquid enthalpy of the flash evaporator and the saturated liquid enthalpy of the first indoor heat exchanger to the latent heat of phase change of the first indoor heat exchanger as the inlet dryness of the third electronic expansion valve; and / or, the control unit determines the predicted noise of the third electronic expansion valve based on the mass flow rate of the third electronic expansion valve and the inlet dryness of the third electronic expansion valve. This includes: determining the predicted noise of the third electronic expansion valve as the sum of a thirteenth preset calculation factor multiple of the square of the mass flow rate of the third electronic expansion valve, a fourteenth preset calculation factor multiple of the mass flow rate of the third electronic expansion valve, a fifteenth preset calculation factor multiple of the inlet dryness of the third electronic expansion valve, and a sixteenth preset calculation factor.

[0015] In some embodiments, the control unit adjusts the frequency of the compressor, or adjusts the opening degree of the second electronic expansion valve and the third electronic expansion valve, based on the predicted noise of the third electronic expansion valve and the exhaust superheat of the compressor, including: determining whether the predicted noise of the third electronic expansion valve is greater than or equal to a preset noise threshold; if the predicted noise of the third electronic expansion valve is determined to be less than the preset noise threshold, controlling the heat pump air conditioning system to maintain its current operation; if the predicted noise of the third electronic expansion valve is determined to be greater than or equal to the preset noise threshold, then adjusting the frequency of the compressor, or adjusting the opening degree of the second electronic expansion valve and the third electronic expansion valve, based on the exhaust superheat of the compressor.

[0016] In some embodiments, the control unit adjusts the frequency of the compressor, or adjusts the opening of the second electronic expansion valve and the third electronic expansion valve, based on the compressor's exhaust superheat, including: determining whether the compressor's exhaust superheat is greater than or equal to a preset superheat threshold; if the compressor's exhaust superheat is determined to be greater than or equal to the preset superheat threshold, then controlling the compressor's frequency to decrease by a set frequency based on the current value, and then returning to re-determine whether the difference between the indoor ambient temperature and the set temperature of the heat pump air conditioning system is greater than or equal to a preset temperature threshold; if the compressor's exhaust superheat is determined to be less than the preset superheat threshold, then controlling the opening of the second electronic expansion valve to decrease by a first set opening based on the current value, and controlling the opening of the third electronic expansion valve to decrease by a second set opening based on the current value, and then returning to re-determine whether the difference between the indoor ambient temperature and the set temperature of the heat pump air conditioning system is greater than or equal to a preset temperature threshold.

[0017] In conjunction with the above-mentioned device, the present invention further provides a heat pump air conditioning system, including: the control device for the heat pump air conditioning system described above.

[0018] In conjunction with the above method, the present invention further provides a storage medium comprising a stored program, wherein, when the program is executed, the device containing the storage medium is controlled to perform the steps of the control method for the heat pump air conditioning system described above.

[0019] In conjunction with the above method, the present invention further provides a computer program product, including a computer program that, when executed by a processor, implements the steps of the control method for the heat pump air conditioning system described above.

[0020] Therefore, the solution of this invention, for a heat pump air conditioning system employing a three-pipe dual-temperature parallel compression system, after a certain period of cooling operation, acquires the indoor ambient temperature, the pipe temperature of the first indoor heat exchanger, the pipe temperature of the second indoor heat exchanger, the compressor's exhaust superheat, and the outlet saturated liquid enthalpy of the flash evaporator. When the difference between the indoor ambient temperature and the set temperature is greater than or equal to a preset temperature threshold, the predicted noise of the electronic expansion valve (i.e., the third electronic expansion valve) connected to the second indoor heat exchanger is calculated based on the pipe temperatures of the first and second indoor heat exchangers and the outlet saturated liquid enthalpy of the flash evaporator. Then, based on the predicted noise of the third electronic expansion valve and the compressor's exhaust superheat, the compressor frequency is adjusted or the opening of the second and third electronic expansion valves is adjusted. Thus, by calculating the predicted noise of the third electronic expansion valve (i.e., the indoor unit-side electronic expansion valve), and adjusting the compressor frequency or the opening of the second and third electronic expansion valves based on the compressor's exhaust superheat, the mass flow rate of the third electronic expansion valve is reduced, thereby reducing noise and improving the user's comfort experience.

[0021] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention.

[0022] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0023] Figure 1 This is a flowchart illustrating an embodiment of the control method for a heat pump air conditioning system according to the present invention;

[0024] Figure 2 This is a schematic flowchart of an embodiment of the method of the present invention for determining the predicted noise of the third electronic expansion valve;

[0025] Figure 3 This is a schematic flowchart of an embodiment of the method of the present invention, which adjusts the frequency of the compressor or the opening degree of the second electronic expansion valve and the opening degree of the third electronic expansion valve based on the predicted noise of the third electronic expansion valve and the exhaust superheat of the compressor.

[0026] Figure 4 This is a schematic flowchart of an embodiment of the method of the present invention, which adjusts the frequency of the compressor or the opening degree of the second electronic expansion valve and the third electronic expansion valve according to the exhaust superheat of the compressor.

[0027] Figure 5 This is a schematic diagram of the structure of a control device for a heat pump air conditioning system according to an embodiment of the present invention;

[0028] Figure 6 This is a schematic diagram of the structure of a heat pump air conditioning system in cooling mode according to the present invention;

[0029] Figure 7 This is a flowchart illustrating a control method for reducing flow noise in an electronic expansion valve of a heat pump air conditioning system according to the present invention.

[0030] Referring to the accompanying drawings, the reference numerals in the embodiments of the present invention are as follows:

[0031] 1-Three-cylinder parallel compressor; 1a-Parallel supplementary cylinder of compressor; 1b-First main cylinder of compressor; 1c-Second main cylinder of compressor; 2-First four-way valve; 3-Second four-way valve; 4-First heat exchanger; 5-First throttling device; 6-Flash evaporator; 7-Second throttling device; 8-Third throttling device; 9-Second heat exchanger; 10-Third heat exchanger; 102-Acquisition unit; 104-Control unit. Detailed Implementation

[0032] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below in conjunction with specific embodiments and corresponding drawings. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0033] Considering that in a heat pump air conditioning system, when the three-pipe dual-temperature parallel compression system is running in cooling mode, the refrigerant on the inlet side of the electronic expansion valve on the indoor unit side is in a two-phase state. When the two-phase refrigerant flows through the electronic expansion valve, it will generate different degrees of flow noise. Since this valve is located on the indoor side, excessive noise will affect the indoor comfort.

[0034] Therefore, the present invention proposes a control method for a heat pump air conditioning system, specifically a control method for reducing the flow noise of the electronic expansion valve in a heat pump air conditioning system. This method makes reasonable assumptions and empirical fittings regarding the potential relationships between the system state parameters and refrigerant property parameters of the heat pump air conditioning system. Using temperature measurement data from various temperature sensing points in the heat pump air conditioning system, the maximum mass flow rate and inlet dryness of the electronic expansion valve on the indoor unit side are accurately calculated. The method of reducing the maximum mass flow rate within the valve by adjusting system parameters reduces noise. While considering the energy efficiency of the heat pump air conditioning system, this method reduces the flow noise of the electronic expansion valve and improves indoor comfort.

[0035] According to embodiments of the present invention, a control method for a heat pump air conditioning system is provided, such as... Figure 1 The diagram shows a flow chart of an embodiment of the method of the present invention. The heat pump air conditioning system has a three-pipe dual-temperature parallel compression system, which includes a compressor, an outdoor heat exchanger, two indoor heat exchangers, and a flash evaporator 6. The two indoor heat exchangers include a first indoor heat exchanger and a second indoor heat exchanger. A first electronic expansion valve is provided between the outdoor heat exchanger and the flash evaporator 6, and a second electronic expansion valve is provided between the flash evaporator 6 and the two indoor heat exchangers. A third electronic expansion valve is provided between the second electronic expansion valve and the second indoor heat exchanger (such as a third heat exchanger 10), and on the pipeline where the second indoor heat exchanger (such as the third heat exchanger 10) is located. The compressor is such as a three-cylinder parallel compressor 1, the outdoor heat exchanger is such as a first heat exchanger 4, the first electronic expansion valve is a first throttling device 5, the second electronic expansion valve is such as a second throttling device 7, the third electronic expansion valve is such as a third throttling device 8, the first indoor heat exchanger is such as a second heat exchanger 9, and the second indoor heat exchanger is such as a third heat exchanger 10. Figure 6 This is a schematic diagram of the structure of a heat pump air conditioning system of the present invention in cooling mode. Figure 6The heat pump air conditioning system shown includes: a three-cylinder parallel compressor 1, a compressor parallel injection cylinder 1a, a compressor first main cylinder 1b, a compressor second main cylinder 1c, a first four-way valve 2, a second four-way valve 3, a first heat exchanger 4, a first throttling device 5, a flash evaporator 6, a second throttling device 7, a third throttling device 8, a second heat exchanger 9, and a third heat exchanger 10. The first heat exchanger 4 is an outdoor heat exchanger, and the second heat exchanger 9 and the third heat exchanger 10 are indoor heat exchangers. The three-cylinder parallel compressor 1 includes a compressor parallel injection cylinder 1a, a compressor first main cylinder 1b, and a compressor second main cylinder 1c. The exhaust port of the three-cylinder parallel compressor 1 is connected to the D end of the first four-way valve 2 and the D end of the second four-way valve 3, respectively. The S end of the first four-way valve 2 is connected to the second main cylinder 1c of the compressor. The C end of the first four-way valve 2, after passing through the first heat exchanger 4, the first throttling device 5, the flash evaporator 6, and the second throttling device 7, is divided into two paths: one path passes through the second heat exchanger 9 and connects to the E end of the first four-way valve 2, and the other path passes through the third throttling device 8 and the third heat exchanger 10 and connects to the E end of the second four-way valve 3. The S end of the second four-way valve 3 is connected to the first main cylinder 1b of the compressor, and the C end of the second four-way valve 3 is connected to the C end of the first four-way valve 2. The first throttling device 5 is connected to the first end of the flash evaporator 6, the second end of the flash evaporator 6 is connected to the second throttling device 7, and the third end of the flash evaporator 6 is connected to the parallel supplementary cylinder 1a of the compressor.

[0036] In such Figure 6 The heat pump air conditioning system shown includes a first refrigerant circuit, a second refrigerant circuit, and a third refrigerant circuit. The first refrigerant circuit consists of a compressor first main cylinder 1b, a first four-way valve 2, a first heat exchanger 4, a first throttling device 5, a flash evaporator 6, a second throttling device 7, a second heat exchanger 9, and an auxiliary piping system. The second refrigerant circuit consists of a compressor second main cylinder 1c, a second four-way valve 3, a first heat exchanger 4, a first throttling device 5, a flash evaporator 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 consists of a compressor parallel injection cylinder 1a, a first four-way valve 2, a first heat exchanger 4, a first throttling device 5, a flash evaporator 6, and an auxiliary piping system.

[0037] like Figure 6When the heat pump air conditioning system shown is running in cooling mode, the 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 and S ends of the first four-way valve 2 and the second four-way valve 3 are connected, and the D and C ends of the first four-way valve 2 and the second four-way valve 3 are connected. The first throttling device 5, the second throttling device 7, and the third throttling device 8 open and are controlled according to the preset logic in cooling mode. The high-temperature and high-pressure refrigerant gas discharged from the first main cylinder 1b of the compressor mixes with the high-temperature and high-pressure refrigerant gas discharged from the second main cylinder 1c of the compressor and the parallel supplementary cylinder 1a, and then flows through the first four-way valve 2 and the second four-way valve 3 respectively. After merging again, it enters the first heat exchanger 4. After the refrigerant is cooled and condensed, it passes through the first section... The refrigerant is throttled to an intermediate pressure by the flow device 5 and enters the flash evaporator 6. In the flash evaporator 6, the gas and liquid are separated into saturated or nearly saturated gas and liquid. The saturated or nearly saturated gas enters the compressor parallel gas cylinder 1a from the gas replenishment 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 second main cylinder 1c of the compressor 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 first main cylinder 1b of the compressor to complete the second refrigerant cycle.

[0038] In the solution of the present invention, such as Figure 1 As shown, the control method of the heat pump air conditioning system includes steps S110 to S160.

[0039] In step S110, after the heat pump air conditioning system is turned on in cooling mode, the indoor unit fan speed of the heat pump air conditioning system is controlled to the set fan speed, and the opening degrees of the first electronic expansion valve, the second electronic expansion valve, and the third electronic expansion valve are all controlled to their respective set values. Specifically, Figure 7 This is a schematic flowchart illustrating a control method for reducing flow noise in an electronic expansion valve of a heat pump air conditioning system according to the present invention. Figure 7 As shown, the control process for reducing the flow noise of the electronic expansion valve in a heat pump air conditioning system includes: Step 1, the heat pump air conditioning system starts up in cooling mode, and then proceeds to Step 2. Step 2, based on the indoor ambient temperature, outdoor ambient temperature, and set temperature t... 设 Step 1 involves setting the control algorithm for the indoor unit fan speed and the opening of the electronic expansion valve, determining the system operating parameters and the openings of the three electronic expansion valves (B1, B2, and B3), and then adjusting them. Step 2 is then executed. The control logic in step 2 can operate according to the refrigeration control logic in relevant solutions, such as the refrigeration control logic in the applicant's prior application with application number 202311076900X.

[0040] In step S120, after the heat pump air conditioning system has been running in cooling mode for a set time, the indoor ambient temperature, the pipe temperature of the first indoor heat exchanger, the pipe temperature of the second indoor heat exchanger, the exhaust superheat of the compressor, and the outlet saturated liquid enthalpy of the flash evaporator 6 are acquired according to a set cycle. The pipe temperature of the first indoor heat exchanger is the temperature at the middle of the flow path of the first indoor heat exchanger, such as the temperature t at the middle of the flow path of the second heat exchanger 9. e_h The tube temperature of the second indoor heat exchanger is the temperature at the middle of the flow path of the second indoor heat exchanger, such as the temperature t at the middle of the flow path of the third heat exchanger 10. e_l In the solution of this invention, the system detection parameters include: inner ring temperature t 内环 The temperature is collected by an ambient temperature sensor located in the indoor heat exchanger; the set temperature t 设 The temperature t in the middle of the flow path of the second heat exchanger 9 and the third heat exchanger 10 is set by the user. e_h t e_l The temperature is collected by temperature sensors located in the middle of the flow paths of the second heat exchanger 9 and the third heat exchanger 10, respectively; the exhaust temperature t dis The temperature is collected by a temperature sensor placed on the exhaust pipe of the compressor (such as a three-cylinder parallel compressor 1); the frequency f of the compressor (such as a three-cylinder parallel compressor 1) is obtained by the system detection.

[0041] In step S130, it is determined whether the difference between the indoor ambient temperature and the set temperature of the heat pump air conditioning system is greater than or equal to a preset temperature threshold. The preset temperature threshold is, for example, t. a .like Figure 7 As shown, the control process for reducing the flow noise of the electronic expansion valve in a heat pump air conditioning system also includes: Step 3, after running for time T1, detecting the temperature t of the inner ring temperature sensing bulb. 内环 and the set temperature t 设 Comparison, i.e., determining whether t is satisfied. 内环 -t 设 ≥t a If yes, return to step 2; otherwise, proceed to step 4. The time T1 ranges from 2 to 10 minutes; the temperature t... a The value range is 0-5℃, with 2℃ being the preferred value.

[0042] In step S140, if it is determined that the difference between the indoor ambient temperature of the heat pump air conditioning system and the set temperature is greater than or equal to the preset temperature threshold, then the heat pump air conditioning system is controlled to maintain the current operation, that is, the heat pump air conditioning system is controlled to continue to operate according to the current control parameters.

[0043] In step S150, if it is determined that the difference between the indoor ambient temperature and the set temperature of the heat pump air conditioning system is less than a preset temperature threshold, then the predicted noise of the third electronic expansion valve is determined based on the pipe temperature of the first indoor heat exchanger, the pipe temperature of the second indoor heat exchanger, and the outlet saturated liquid enthalpy of the flash evaporator 6. Figure 7 As shown, the control process for reducing the flow noise of the electronic expansion valve in a heat pump air conditioning system further includes: Step 4: Calculate the predicted total noise value Z of the third electronic expansion valve based on the system detection parameters, according to the empirical correlation and intermediate process below, and then execute Step 5 to determine whether the predicted noise Z of the third electronic expansion valve is satisfied. b .

[0044] In some embodiments, the specific process of determining the predicted noise of the third electronic expansion valve in step S150 based on the tube temperature of the first indoor heat exchanger, the tube temperature of the second indoor heat exchanger, and the outlet saturated liquid enthalpy of the flash evaporator 6 is described in the following exemplary description.

[0045] The following is combined Figure 2 The schematic diagram shown is a flowchart of an embodiment of the method of the present invention for determining the predicted noise of the third electronic expansion valve. The specific process of determining the predicted noise of the third electronic expansion valve in step S150 is further explained, including steps S210 to S250.

[0046] Step S210: Determine the inlet and outlet pressure difference of the third electronic expansion valve based on the tube temperature of the first indoor heat exchanger and the tube temperature of the second indoor heat exchanger (e.g., the inlet and outlet pressure difference of the third electronic expansion valve is ΔP). r3 ); and based on the pipe temperature of the first indoor heat exchanger, determine the inlet saturated liquid density of the third electronic expansion valve (e.g., the saturated liquid density ρ at the inlet of the third electronic expansion valve). r3 ).

[0047] In some embodiments, step S210, determining the inlet and outlet pressure difference of the third electronic expansion valve based on the pipe temperatures of the first and second indoor heat exchangers, includes: determining the difference between the square of the pipe temperature of the first and second indoor heat exchangers as a first difference, determining the difference between the pipe temperatures of the first and second indoor heat exchangers as a second difference, and determining the sum of a first preset calculation coefficient multiple of the first difference and a second preset calculation coefficient multiple of the second difference as the inlet and outlet pressure difference of the third electronic expansion valve; wherein the first preset calculation coefficient is, for example, a1, and the second preset calculation coefficient is, for example, b1. Figure 7 As shown, the control process for reducing the flow noise of the electronic expansion valve in a heat pump air conditioning system further includes: In step 4, the empirical correlation formula and calculation process formula include:

[0048] Pressure difference ΔP=a1*(t1) 2 -t2 2 )+b1*(t1-t2), where t1 and t2 represent two different saturation temperatures, and the pressure difference ΔP represents the pressure difference between the two saturation temperatures t1 and t2; a1 and b1 are values ​​fitted from refrigerant property software. For example, for R32 refrigerant, the pressure difference between the inlet and outlet of the third throttling device 8, such as the third electronic expansion valve, is ΔP. r3 =509.46*(t e_h 2 -t e_l 2 )+20853*(t e_h -t e_l ), t e_h The temperature at the middle of the flow path of the second heat exchanger 9, t e_l This refers to the temperature at the midpoint of the flow path in the third heat exchanger 10. In other words, it refers to the inlet and outlet pressure difference ΔP of the third electronic expansion valve. r3 =f(t) e_h , t e_l ).

[0049] In some embodiments, determining the inlet saturated liquid density of the third electronic expansion valve based on the pipe temperature of the first indoor heat exchanger in step S210 includes: determining the inlet saturated liquid density of the third electronic expansion valve as the sum of a third preset calculation factor multiple of the square of the pipe temperature of the first indoor heat exchanger, a fourth preset calculation factor multiple of the pipe temperature of the first indoor heat exchanger, and a fifth preset calculation factor; wherein the third preset calculation factor is such as a1, the fourth preset calculation factor is such as b2, and the fifth preset calculation factor is such as c2. Figure 7 As shown, the control process for reducing the flow noise of the electronic expansion valve in a heat pump air conditioning system further includes: In step 4, the empirical correlation formula and calculation process formula also include:

[0050] The saturated liquid density of the refrigerant ρ = a²tt + b²t + c², where a², b², and c² are values ​​fitted from refrigerant property software. For example, the saturated liquid density ρ at the inlet of the third electronic expansion valve for R32 refrigerant. r3 =-0.031*t e_h *t e_h -2.7548t e_h +1051.3. That is to say, the inlet density ρ of the third electronic expansion valve... r3 =f(t) e_h ).

[0051] Step S220: Determine the mass flow rate of the third electronic expansion valve (e.g., the mass flow rate G3 of the third electronic expansion valve) based on the inlet and outlet pressure difference of the third electronic expansion valve and the inlet saturated liquid density of the third electronic expansion valve.

[0052] In some embodiments, step S220, determining the mass flow rate of the third electronic expansion valve based on the inlet-outlet pressure difference and the inlet saturated liquid density of the third electronic expansion valve, includes: determining the mass flow rate of the third electronic expansion valve as the product of the half-power of the inlet-outlet pressure difference, the inlet saturated liquid density of the third electronic expansion valve, and a sixth preset calculation coefficient. The sixth preset calculation coefficient is c1, such as 0.0283. Figure 7 As shown, the control process for reducing the flow noise of the electronic expansion valve in a heat pump air conditioning system further includes: In step 4, the empirical correlation formula and calculation process formula also include:

[0053] The third throttling device 8 can be an electronic expansion valve, with a maximum mass flow rate G3 = 0.0283 * ρ within the electronic expansion valve. r3 *(ΔP r3 ) 0.5 In other words, the mass flow rate of the third electronic expansion valve is G3 = f(ΔP). r3 , ρ r3 ).

[0054] Step S230: Determine the saturated liquid enthalpy of the first indoor heat exchanger (e.g., the saturated liquid enthalpy h of the second heat exchanger 9) based on the tube temperature of the first indoor heat exchanger. e_h_f ); and based on the tube temperature of the first indoor heat exchanger, determine the latent heat of phase change of the first indoor heat exchanger (such as the latent heat of phase change h of the second heat exchanger 9). e_h_fg ).

[0055] In some embodiments, determining the saturated liquid enthalpy of the first indoor heat exchanger based on the tube temperature of the first indoor heat exchanger includes: determining the saturated liquid enthalpy of the first indoor heat exchanger as the sum of the product of the square of the tube temperature of the first indoor heat exchanger and a seventh preset calculation coefficient, the product of the tube temperature of the first indoor heat exchanger and an eighth preset calculation coefficient, and a ninth preset calculation coefficient; wherein the seventh preset calculation coefficient is such as a3, the eighth preset calculation coefficient is such as b3, and the ninth preset calculation coefficient is such as c3. Figure 7 As shown, the control process for reducing the flow noise of the electronic expansion valve in a heat pump air conditioning system further includes: In step 4, the empirical correlation formula and calculation process formula also include:

[0056] Specific enthalpy h of subcooled or saturated liquid refrigerant f=a3*t*t+b3*t+c3, where a3, b3, and c3 are values ​​fitted from refrigerant property software. For example, for R32 refrigerant, the saturated liquid enthalpy h of the second heat exchanger 9. e_h_f =0.0039*t e_h *t e_h +1.7246*t e_h +200.06. That is to say, the saturated liquid enthalpy h of the second heat exchanger 9... e_h_f =f(t) e_h ).

[0057] In some embodiments, step S230, determining the latent heat of phase change of the first indoor heat exchanger based on the tube temperature of the first indoor heat exchanger, includes: determining the latent heat of phase change of the first indoor heat exchanger as the sum of the product of the square of the tube temperature of the first indoor heat exchanger and a tenth preset calculation coefficient, the product of the tube temperature of the first indoor heat exchanger and an eleventh preset calculation coefficient, and a twelfth preset calculation coefficient; wherein the tenth preset calculation coefficient is such as a4, the eleventh preset calculation coefficient is such as b4, and the twelfth preset calculation coefficient is such as c4. Figure 7 As shown, the control process for reducing the flow noise of the electronic expansion valve in a heat pump air conditioning system further includes: In step 4, the empirical correlation formula and calculation process formula also include:

[0058] latent heat of phase change of refrigerant h fg =a4*t*t+b4*t+c4, where a4, b4, and c4 are values ​​fitted from refrigerant property software. For example, for R32 refrigerant, the latent heat of phase change h of the second heat exchanger 9. e_h_fg =-0.0181*t e_h *t e_h -1.1988*t e_h +313.22. That is to say, the latent heat of phase change h of the second heat exchanger 9. e_h_fg =f(t) e_h In this context, the subscripts fg represent the latent heat of phase change, f represents the supercooled or saturated liquid state, and g represents the saturated gas state.

[0059] Step S240: Determine the inlet dryness of the third electronic expansion valve (e.g., inlet dryness of the third electronic expansion valve x3) based on the outlet saturated liquid enthalpy of the flash evaporator 6, the saturated liquid enthalpy of the first indoor heat exchanger, and the latent heat of phase change of the first indoor heat exchanger.

[0060] In some embodiments, determining the inlet dryness of the third electronic expansion valve in step S240 based on the outlet saturated liquid enthalpy of the flash evaporator 6, the saturated liquid enthalpy of the first indoor heat exchanger, and the latent heat of phase change of the first indoor heat exchanger includes: determining the inlet dryness of the third electronic expansion valve as the ratio of the difference between the outlet saturated liquid enthalpy of the flash evaporator 6 and the saturated liquid enthalpy of the first indoor heat exchanger to the latent heat of phase change of the first indoor heat exchanger. Figure 7 As shown, the control process for reducing the flow noise of the electronic expansion valve in a heat pump air conditioning system further includes: In step 4, the empirical correlation formula and calculation process formula also include:

[0061] The inlet dryness of the third electronic expansion valve x3 = (h f -h e_h_f ) / h e_h_fg ; where h e_h_f h is the saturated liquid enthalpy of the second heat exchanger. e_h_fg This is the latent heat of phase change in the second heat exchanger 9. In other words, the inlet dryness fraction of the third electronic expansion valve x3 = f(h) f h e_h_f h e_h_fg h f The saturated liquid enthalpy at the outlet of the flash evaporator 6, specifically the saturated liquid enthalpy at the outlet where the flash evaporator 6 is connected to the second throttling device 7, can be calculated. It can be calculated according to the calculation method in the relevant scheme, such as the saturated liquid enthalpy calculation formula in the applicant's earlier application with application number 202311076900X.

[0062] Step S250: Determine the predicted noise of the third electronic expansion valve (e.g., the predicted noise Z of the third electronic expansion valve) based on the mass flow rate of the third electronic expansion valve and the inlet dryness of the third electronic expansion valve.

[0063] In some embodiments, step S250, determining the predicted noise of the third electronic expansion valve based on its mass flow rate and inlet dryness, includes: determining the predicted noise of the third electronic expansion valve as the sum of a thirteenth preset calculation factor multiple of the square of the mass flow rate, a fourteenth preset calculation factor multiple of the mass flow rate, a fifteenth preset calculation factor multiple of the inlet dryness, and a sixteenth preset calculation factor. Wherein, the thirteenth preset calculation factor is such as a, the fourteenth preset calculation factor is such as b, the fifteenth preset calculation factor is such as c, and the sixteenth preset calculation factor is such as d. Figure 7 As shown, the control process for reducing the flow noise of the electronic expansion valve in a heat pump air conditioning system further includes: In step 4, the empirical correlation formula and calculation process formula also include:

[0064] The predicted noise of the third electronic expansion valve is Z=a*G3 2 +b*G3+c*x3+d, where the range of values ​​for a is -6.3*10 -7 ~0, the preferred value is -2.38*10 -7 The value of b is in the range of 3.3 * 10. -3 ~8.5*10 -3 The preferred value is 5.86*10 -3 The value of c ranges from 0 to 250, with a preferred value of 25.63; the value of d ranges from -15 to 17, with a preferred value of 0.873; G3 is the maximum mass flow rate inside the electronic expansion valve, and x3 is the inlet dryness of the third electronic expansion valve. In other words, the predicted noise of the third electronic expansion valve is Z = f(G3, x3).

[0065] This invention addresses the flow noise problem of the electronic expansion valve on the indoor unit side of a three-pipe dual-temperature parallel compression system and similar multi-electronic expansion valve systems. A novel control scheme is proposed that can reduce the flow noise of the electronic expansion valve while maintaining the energy efficiency of the heat pump air conditioning system, thereby improving indoor comfort. The proposed control scheme makes reasonable assumptions and empirical fittings regarding the potential relationships between the system state parameters and refrigerant properties of the heat pump air conditioning system. Using temperature measurement data from various temperature sensing points in the heat pump air conditioning system, it accurately calculates the maximum mass flow rate and inlet dryness of the electronic expansion valve on the indoor unit side. By controlling the opening degree of the electronic expansion valve in conjunction with the compressor frequency, the maximum mass flow rate within the valve is reduced, thereby lowering the noise.

[0066] At step S160, the frequency of the compressor is adjusted, or the opening degree of the second electronic expansion valve and the opening degree of the third electronic expansion valve are adjusted, based on the predicted noise of the third electronic expansion valve and the exhaust superheat of the compressor, so as to reduce the actual noise of the third electronic expansion valve.

[0067] The present invention proposes a scheme for real-time calculation of the maximum mass flow rate and inlet dryness of the electronic expansion valve based on system detection parameters. It also proposes a fitting correlation between the total noise value of the electronic expansion valve and its main influencing parameters, such as the maximum mass flow rate and inlet dryness. Furthermore, it proposes a control scheme that combines the electronic expansion valve with the compressor frequency to reduce the maximum mass flow rate and ultimately reduce the noise of the electronic expansion valve. This approach can reduce the flow noise of the electronic expansion valve while taking into account the energy efficiency of the heat pump air conditioning system, thereby improving indoor comfort.

[0068] In some embodiments, the specific process of adjusting the frequency of the compressor or adjusting the opening degree of the second electronic expansion valve and the third electronic expansion valve in step S160 based on the predicted noise of the third electronic expansion valve and the exhaust superheat of the compressor is described in the following exemplary description.

[0069] The following is combined Figure 3 The schematic diagram shows an embodiment of the method of the present invention, which adjusts the frequency of the compressor or the opening degree of the second and third electronic expansion valves based on the predicted noise of the third electronic expansion valve and the exhaust superheat of the compressor. Further explanation is provided regarding the specific process of adjusting the frequency of the compressor or the opening degree of the second and third electronic expansion valves based on the predicted noise of the third electronic expansion valve and the exhaust superheat of the compressor in step S160, including steps S310 to S330.

[0070] Step S310: Determine whether the predicted noise of the third electronic expansion valve is greater than or equal to a preset noise threshold; wherein, the preset noise threshold is as follows: b .

[0071] Step S320: If it is determined that the predicted noise of the third electronic expansion valve is less than the preset noise threshold, control the heat pump air conditioning system to maintain the current operation, that is, control the heat pump air conditioning system to continue to operate according to the current control parameters.

[0072] Step S330: If it is determined that the predicted noise of the third electronic expansion valve is greater than or equal to a preset noise threshold, then the frequency of the compressor is adjusted according to the exhaust superheat of the compressor, or the opening degree of the second electronic expansion valve and the opening degree of the third electronic expansion valve are adjusted.

[0073] like Figure 7 As shown, the control process for reducing the flow noise of the electronic expansion valve in a heat pump air conditioning system also includes: Step 5, determining whether the predicted noise Z of the third electronic expansion valve is satisfied. b If yes, proceed to step 6; otherwise, if the predicted noise Z of the third electronic expansion valve is less than Z... b If the noise level is low and will not affect indoor comfort, then all control parameters remain unchanged. Among them, Z... b The value range is 25-40 dB(A), where dB(A) represents decibels and A represents weighted sound.

[0074] Step 6: If the predicted noise Z of the third electronic expansion valve ≥ Z b If the noise level is deemed to be affecting indoor comfort, then the next step for adjustment and control is executed, namely step 7, to determine whether the compressor's exhaust superheat d is met. t_dis ≥dc .

[0075] In this invention, a three-pipe, dual-temperature parallel compression system is employed. The indoor heat exchanger is divided into two heat exchangers with different evaporation temperatures, utilizing their cascaded heat exchange effect. The inlet of the indoor electronic expansion valve is in a two-phase state to varying degrees, which is relatively easy to generate flow noise. The method involves calculating the electronic expansion valve noise in real time using system detection parameters and reducing the noise by adjusting system parameters. Specifically, this method correlates the intangible noise with mass flow rate and dryness, making the complex problem concrete. By controlling the opening of the electronic expansion valve in conjunction with the compressor frequency, the maximum mass flow rate within the valve is reduced, thereby reducing noise. However, related solutions that add a subcooler controlled by the electronic expansion valve to ensure subcooling at the indoor unit valve inlet prevents it from entering the two-phase liquid flow noise range have certain limitations and may not be effective under harsh operating conditions or when there is partial refrigerant leakage.

[0076] In some embodiments, the specific process of adjusting the frequency of the compressor or adjusting the opening degree of the second electronic expansion valve and the third electronic expansion valve according to the exhaust superheat of the compressor in step S330 is described in the following exemplary description.

[0077] The following is combined Figure 4 The schematic diagram shows an embodiment of the method of the present invention, which adjusts the frequency of the compressor or the opening degree of the second electronic expansion valve and the third electronic expansion valve according to the exhaust superheat of the compressor. It further illustrates the specific process of adjusting the frequency of the compressor or the opening degree of the second electronic expansion valve and the third electronic expansion valve according to the exhaust superheat of the compressor in step S330, including steps S410 to S430.

[0078] Step S410: Determine whether the exhaust superheat of the compressor is greater than or equal to a preset superheat threshold; wherein, the preset superheat threshold is as follows: c .

[0079] Step S420: If it is determined that the superheat of the compressor is greater than or equal to the preset superheat threshold, the frequency of the compressor is controlled to be reduced from the current value to a set frequency, and then the process is returned to re-determine whether the difference between the indoor ambient temperature and the set temperature of the heat pump air conditioning system is greater than or equal to the preset temperature threshold.

[0080] Step S430: If it is determined that the superheat of the compressor's exhaust is less than the preset superheat threshold, then the opening of the second electronic expansion valve is reduced by a first set opening based on the current value, and the opening of the third electronic expansion valve is reduced by a second set opening based on the current value. Then return to re-determine whether the difference between the indoor ambient temperature and the set temperature of the heat pump air conditioning system is greater than or equal to the preset temperature threshold.

[0081] like Figure 7 As shown, the control process for reducing the flow noise of the electronic expansion valve in a heat pump air conditioning system also includes: Step 7, determining whether the compressor's exhaust superheat d is met. t_dis ≥d c If yes, proceed to step 8; otherwise, proceed to step 9. Where d c The value range is 10-25℃.

[0082] Step 8: If the compressor's exhaust superheat d is satisfied... t_dis ≥d c If this happens, the compressor's operating frequency f is reduced, and then the process returns to step 3. Here, the compressor's exhaust superheat d... t_dis , is the exhaust temperature t dis Based on calculations.

[0083] Step 9: If the compressor's exhaust superheat d is not met... t_dis ≥d c Then, decrease the opening degree B2 of the second electronic expansion valve and increase the opening degree B3 of the third electronic expansion valve, and then return to step 3.

[0084] In this invention, the total noise value of the electronic expansion valve is correlated with its main influencing parameters, such as the maximum mass flow rate within the valve and the inlet dryness (i.e., the dryness of the inlet). When the fitted predicted total noise value is higher than a certain set value, the flow noise is considered too high. The noise is reduced by adjusting system parameters to decrease the maximum mass flow rate within the valve. Specific methods include reducing the compressor operating frequency to decrease the refrigerant flow rate, thereby reducing the maximum mass flow rate within the valve; reducing the outlet superheat of the third heat exchanger and increasing the outlet superheat of the second heat exchanger to reduce the evaporation temperature difference between the two heat exchangers, i.e., reducing the pressure difference of the third electronic expansion valve, thereby reducing the maximum mass flow rate within the valve; and so on. By controlling the opening of the electronic expansion valve in conjunction with the compressor frequency, the maximum mass flow rate within the valve is reduced, thus lowering the noise.

[0085] The technical solution of this embodiment, for a heat pump air conditioning system employing a three-pipe dual-temperature parallel compression system, after a certain period of cooling operation, acquires the indoor ambient temperature, the pipe temperature of the first indoor heat exchanger, the pipe temperature of the second indoor heat exchanger, the compressor's exhaust superheat, and the outlet saturated liquid enthalpy of the flash evaporator. When the difference between the indoor ambient temperature and the set temperature is greater than or equal to a preset temperature threshold, the predicted noise of the electronic expansion valve (i.e., the third electronic expansion valve) connected to the second indoor heat exchanger is calculated based on the pipe temperatures of the first and second indoor heat exchangers and the outlet saturated liquid enthalpy of the flash evaporator. Then, based on the predicted noise of the third electronic expansion valve and the compressor's exhaust superheat, the compressor frequency or the opening degree of the second and third electronic expansion valves is adjusted. Thus, by calculating the predicted noise of the third electronic expansion valve (i.e., the indoor unit-side electronic expansion valve), adjusting the compressor frequency or the opening degree of the second and third electronic expansion valves based on the compressor's exhaust superheat, the mass flow rate of the third electronic expansion valve is reduced, thereby reducing noise and improving the user's comfort experience.

[0086] According to an embodiment of the present invention, a control device for a heat pump air conditioning system corresponding to a control method for a heat pump air conditioning system is also provided. See also Figure 5 The diagram shows a structural schematic of an embodiment of the device of the present invention. The heat pump air conditioning system has a three-pipe dual-temperature parallel compression system, which includes a compressor, an outdoor heat exchanger, two indoor heat exchangers, and a flash evaporator 6. The two indoor heat exchangers include a first indoor heat exchanger and a second indoor heat exchanger. A first electronic expansion valve is provided between the outdoor heat exchanger and the flash evaporator 6, a second electronic expansion valve is provided between the flash evaporator 6 and the two indoor heat exchangers, and a third electronic expansion valve is provided between the second electronic expansion valve and the second indoor heat exchanger, and on the pipeline where the second indoor heat exchanger is located. The compressor is, for example, a three-cylinder parallel compressor 1; the outdoor heat exchanger is, for example, a first heat exchanger 4; the first electronic expansion valve is also a first throttling device 5; the second electronic expansion valve is also a second throttling device 7; the third electronic expansion valve is also a third throttling device 8; the first indoor heat exchanger is also a second heat exchanger 9; and the second indoor heat exchanger is also a third heat exchanger 10. Figure 6 This is a schematic diagram of the structure of a heat pump air conditioning system of the present invention in cooling mode. Figure 6The heat pump air conditioning system shown includes: a three-cylinder parallel compressor 1, a compressor parallel injection cylinder 1a, a compressor first main cylinder 1b, a compressor second main cylinder 1c, a first four-way valve 2, a second four-way valve 3, a first heat exchanger 4, a first throttling device 5, a flash evaporator 6, a second throttling device 7, a third throttling device 8, a second heat exchanger 9, and a third heat exchanger 10. The first heat exchanger 4 is an outdoor heat exchanger, and the second heat exchanger 9 and the third heat exchanger 10 are indoor heat exchangers. The three-cylinder parallel compressor 1 includes a compressor parallel injection cylinder 1a, a compressor first main cylinder 1b, and a compressor second main cylinder 1c. The exhaust port of the three-cylinder parallel compressor 1 is connected to the D end of the first four-way valve 2 and the D end of the second four-way valve 3, respectively. The S end of the first four-way valve 2 is connected to the second main cylinder 1c of the compressor. The C end of the first four-way valve 2, after passing through the first heat exchanger 4, the first throttling device 5, the flash evaporator 6, and the second throttling device 7, is divided into two paths: one path passes through the second heat exchanger 9 and connects to the E end of the first four-way valve 2, and the other path passes through the third throttling device 8 and the third heat exchanger 10 and connects to the E end of the second four-way valve 3. The S end of the second four-way valve 3 is connected to the first main cylinder 1b of the compressor, and the C end of the second four-way valve 3 is connected to the C end of the first four-way valve 2. The first throttling device 5 is connected to the first end of the flash evaporator 6, the second end of the flash evaporator 6 is connected to the second throttling device 7, and the third end of the flash evaporator 6 is connected to the parallel supplementary cylinder 1a of the compressor.

[0087] In such Figure 6 The heat pump air conditioning system shown includes a first refrigerant circuit, a second refrigerant circuit, and a third refrigerant circuit. The first refrigerant circuit consists of a compressor first main cylinder 1b, a first four-way valve 2, a first heat exchanger 4, a first throttling device 5, a flash evaporator 6, a second throttling device 7, a second heat exchanger 9, and an auxiliary piping system. The second refrigerant circuit consists of a compressor second main cylinder 1c, a second four-way valve 3, a first heat exchanger 4, a first throttling device 5, a flash evaporator 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 consists of a compressor parallel injection cylinder 1a, a first four-way valve 2, a first heat exchanger 4, a first throttling device 5, a flash evaporator 6, and an auxiliary piping system.

[0088] like Figure 6When the heat pump air conditioning system shown is running in cooling mode, the 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 and S ends of the first four-way valve 2 and the second four-way valve 3 are connected, and the D and C ends of the first four-way valve 2 and the second four-way valve 3 are connected. The first throttling device 5, the second throttling device 7, and the third throttling device 8 open and are controlled according to the preset logic in cooling mode. The high-temperature and high-pressure refrigerant gas discharged from the first main cylinder 1b of the compressor mixes with the high-temperature and high-pressure refrigerant gas discharged from the second main cylinder 1c of the compressor and the parallel supplementary cylinder 1a, and then flows through the first four-way valve 2 and the second four-way valve 3 respectively. After merging again, it enters the first heat exchanger 4. After the refrigerant is cooled and condensed, it passes through the first section... The refrigerant is throttled to an intermediate pressure by the flow device 5 and enters the flash evaporator 6. In the flash evaporator 6, the gas and liquid are separated into saturated or nearly saturated gas and liquid. The saturated or nearly saturated gas enters the compressor parallel gas cylinder 1a from the gas replenishment 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 second main cylinder 1c of the compressor 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 first main cylinder 1b of the compressor to complete the second refrigerant cycle.

[0089] In the solution of the present invention, such as Figure 5 As shown, the control device of the heat pump air conditioning system includes: an acquisition unit 102 and a control unit 104.

[0090] The control unit 104 is configured to, after the heat pump air conditioning system is turned on in cooling mode, control the indoor unit fan speed of the heat pump air conditioning system to a set fan speed, and control the opening degrees of the first electronic expansion valve, the second electronic expansion valve, and the third electronic expansion valve to their respective set values. The specific functions and processing of this control unit 104 are described in step S110. Specifically, Figure 7 This is a schematic flowchart illustrating a control method for reducing flow noise in an electronic expansion valve of a heat pump air conditioning system according to the present invention. Figure 7 As shown, the control process for reducing the flow noise of the electronic expansion valve in a heat pump air conditioning system includes: Step 1, the heat pump air conditioning system starts up in cooling mode, and then proceeds to Step 2. Step 2, based on the indoor ambient temperature, outdoor ambient temperature, and set temperature t... 设Step 1 involves setting the control algorithm for the indoor unit fan speed and the opening of the electronic expansion valve, determining the system operating parameters and the openings of the three electronic expansion valves (B1, B2, and B3), and then adjusting them. Step 2 is then executed. The control logic in step 2 can operate according to the refrigeration control logic in relevant solutions, such as the refrigeration control logic in the applicant's prior application with application number 202311076900X.

[0091] The acquisition unit 102 is configured to acquire, at a set cycle, the indoor ambient temperature of the heat pump air conditioning system, the pipe temperature of the first indoor heat exchanger, the pipe temperature of the second indoor heat exchanger, the exhaust superheat of the compressor, and the outlet saturated liquid enthalpy of the flash evaporator 6 after the heat pump air conditioning system has been running in cooling mode for a set time. The specific functions and processing of this acquisition unit 102 are described in step S120. The pipe temperature of the first indoor heat exchanger is the temperature at the middle of the flow path of the first indoor heat exchanger, such as the temperature t at the middle of the flow path of the second heat exchanger 9. e_h The tube temperature of the second indoor heat exchanger is the temperature at the middle of the flow path of the second indoor heat exchanger, such as the temperature t at the middle of the flow path of the third heat exchanger 10. e_l In the solution of this invention, the system detection parameters include: inner ring temperature t 内环 The temperature is collected by an ambient temperature sensor located in the indoor heat exchanger; the set temperature t 设 The temperature t in the middle of the flow path of the second heat exchanger 9 and the third heat exchanger 10 is set by the user. e_h t e_l The temperature is collected by temperature sensors located in the middle of the flow paths of the second heat exchanger 9 and the third heat exchanger 10, respectively; the exhaust temperature t dis The temperature is collected by a temperature sensor placed on the exhaust pipe of the compressor (such as a three-cylinder parallel compressor 1); the frequency f of the compressor (such as a three-cylinder parallel compressor 1) is obtained by the system detection.

[0092] The control unit 104 is further configured to determine whether the difference between the indoor ambient temperature and the set temperature of the heat pump air conditioning system is greater than or equal to a preset temperature threshold. The specific functions and processing of the control unit 104 are further described in step S130. The preset temperature threshold is as follows: a .like Figure 7 As shown, the control process for reducing the flow noise of the electronic expansion valve in a heat pump air conditioning system also includes: Step 3, after running for time T1, detecting the temperature t of the inner ring temperature sensing bulb. 内环 and the set temperature t 设 Comparison, i.e., determining whether t is satisfied. 内环 -t 设 ≥t a If yes, return to step 2; otherwise, proceed to step 4. The time T1 ranges from 2 to 10 minutes; the temperature t...a The value range is 0-5℃, with 2℃ being the preferred value.

[0093] The control unit 104 is further configured to, if it is determined that the difference between the indoor ambient temperature of the heat pump air conditioning system and the set temperature is greater than or equal to a preset temperature threshold, control the heat pump air conditioning system to maintain its current operation, that is, to control the heat pump air conditioning system to continue operating according to the current control parameters. The specific functions and processing of this control unit 104 are further described in step S140.

[0094] The control unit 104 is further configured to, if it is determined that the difference between the indoor ambient temperature and the set temperature of the heat pump air conditioning system is less than a preset temperature threshold, determine the predicted noise of the third electronic expansion valve based on the pipe temperature of the first indoor heat exchanger, the pipe temperature of the second indoor heat exchanger, and the outlet saturated liquid enthalpy of the flash evaporator 6. The specific functions and processing of this control unit 104 are further described in step S150. Figure 7 As shown, the control process for reducing the flow noise of the electronic expansion valve in a heat pump air conditioning system further includes: Step 4: Calculate the predicted total noise value Z of the third electronic expansion valve based on the system detection parameters, according to the empirical correlation and intermediate process below, and then execute Step 5 to determine whether the predicted noise Z of the third electronic expansion valve is satisfied. b .

[0095] In some embodiments, the control unit 104 determines the predicted noise of the third electronic expansion valve based on the tube temperature of the first indoor heat exchanger, the tube temperature of the second indoor heat exchanger, and the outlet saturated liquid enthalpy of the flash evaporator 6, including:

[0096] The control unit 104 is further configured to determine the inlet and outlet pressure difference of the third electronic expansion valve (e.g., the inlet and outlet pressure difference of the third electronic expansion valve is ΔP) based on the pipe temperature of the first indoor heat exchanger and the pipe temperature of the second indoor heat exchanger. r3 ); and based on the pipe temperature of the first indoor heat exchanger, determine the inlet saturated liquid density of the third electronic expansion valve (e.g., the saturated liquid density ρ at the inlet of the third electronic expansion valve). r3 For details on the specific functions and processing of the control unit 104, please refer to step S210.

[0097] In some embodiments, the control unit 104 determines the inlet and outlet pressure difference of the third electronic expansion valve based on the pipe temperatures of the first and second indoor heat exchangers. Specifically, the control unit 104 is further configured to: denote the difference between the square of the pipe temperature of the first and second indoor heat exchangers as a first difference; denote the difference between the pipe temperatures of the first and second indoor heat exchangers as a second difference; and determine the sum of a first preset calculation coefficient multiple of the first difference and a second preset calculation coefficient multiple of the second difference as the inlet and outlet pressure difference of the third electronic expansion valve. Wherein, the first preset calculation coefficient is, for example, a1, and the second preset calculation coefficient is, for example, b1. Figure 7 As shown, the control process for reducing the flow noise of the electronic expansion valve in a heat pump air conditioning system further includes: In step 4, the empirical correlation formula and calculation process formula include:

[0098] Pressure difference ΔP=a1*(t1) 2 -t2 2 )+b1*(t1-t2), where t1 and t2 represent two different saturation temperatures, and the pressure difference ΔP represents the pressure difference between the two saturation temperatures t1 and t2; a1 and b1 are values ​​fitted from refrigerant property software. For example, for R32 refrigerant, the pressure difference between the inlet and outlet of the third throttling device 8, such as the third electronic expansion valve, is ΔP. r3 =509.46*(t e_h 2 -t e_l 2 )+20853*(t e_h -t e_l ), t e_h The temperature at the middle of the flow path of the second heat exchanger 9, t e_l This refers to the temperature at the midpoint of the flow path in the third heat exchanger 10. In other words, it refers to the inlet and outlet pressure difference ΔP of the third electronic expansion valve. r3 =f(t) e_h , t e_l ).

[0099] In some embodiments, the control unit 104 determines the inlet saturated liquid density of the third electronic expansion valve based on the pipe temperature of the first indoor heat exchanger. Specifically, the control unit 104 is further configured to determine the inlet saturated liquid density of the third electronic expansion valve as the sum of a third preset calculation coefficient multiple of the square of the pipe temperature of the first indoor heat exchanger, a fourth preset calculation coefficient multiple of the pipe temperature of the first indoor heat exchanger, and a fifth preset calculation coefficient. Wherein, the third preset calculation coefficient is such as a1, the fourth preset calculation coefficient is such as b2, and the fifth preset calculation coefficient is such as c2. Figure 7As shown, the control process for reducing the flow noise of the electronic expansion valve in a heat pump air conditioning system further includes: In step 4, the empirical correlation formula and calculation process formula also include:

[0100] The saturated liquid density of the refrigerant ρ = a²tt + b²t + c², where a², b², and c² are values ​​fitted from refrigerant property software. For example, the saturated liquid density ρ at the inlet of the third electronic expansion valve for R32 refrigerant. r3 =-0.031*t e_h *t e_h -2.7548t e_h +1051.3. That is to say, the inlet density ρ of the third electronic expansion valve... r3 =f(t) e_h ).

[0101] The control unit 104 is further configured to determine the mass flow rate of the third electronic expansion valve (e.g., the mass flow rate G3 of the third electronic expansion valve) based on the inlet and outlet pressure difference of the third electronic expansion valve and the inlet saturated liquid density of the third electronic expansion valve. The specific functions and processing of this control unit 104 are further described in step S220.

[0102] In some embodiments, the control unit 104 determines the mass flow rate of the third electronic expansion valve based on the inlet-outlet pressure difference and the inlet saturated liquid density of the third electronic expansion valve. Specifically, the control unit 104 is further configured to determine the mass flow rate of the third electronic expansion valve as the product of the half-power of the inlet-outlet pressure difference, the inlet saturated liquid density of the third electronic expansion valve, and a sixth preset calculation coefficient. The sixth preset calculation coefficient is c1, such as 0.0283. Figure 7 As shown, the control process for reducing the flow noise of the electronic expansion valve in a heat pump air conditioning system further includes: In step 4, the empirical correlation formula and calculation process formula also include:

[0103] The third throttling device 8 can be an electronic expansion valve, with a maximum mass flow rate G3 = 0.0283 * ρ within the electronic expansion valve. r3 *(ΔP r3 ) 0.5 In other words, the mass flow rate of the third electronic expansion valve is G3 = f(ΔP). r3 , ρ r3 ).

[0104] The control unit 104 is further configured to determine the saturated liquid enthalpy of the first indoor heat exchanger (such as the saturated liquid enthalpy h of the second heat exchanger 9) based on the pipe temperature of the first indoor heat exchanger. e_h_f); and based on the tube temperature of the first indoor heat exchanger, determine the latent heat of phase change of the first indoor heat exchanger (such as the latent heat of phase change h of the second heat exchanger 9). e_h_fg For details on the specific functions and processing of the control unit 104, please refer to step S230.

[0105] In some embodiments, the control unit 104 determines the saturated liquid enthalpy of the first indoor heat exchanger based on the tube temperature of the first indoor heat exchanger. Specifically, the control unit 104 is further configured to determine the saturated liquid enthalpy of the first indoor heat exchanger as the sum of the product of the square of the tube temperature of the first indoor heat exchanger and a seventh preset calculation coefficient, the product of the tube temperature of the first indoor heat exchanger and an eighth preset calculation coefficient, and a ninth preset calculation coefficient. Wherein, the seventh preset calculation coefficient is such as a3, the eighth preset calculation coefficient is such as b3, and the ninth preset calculation coefficient is such as c3. Figure 7 As shown, the control process for reducing the flow noise of the electronic expansion valve in a heat pump air conditioning system further includes: In step 4, the empirical correlation formula and calculation process formula also include:

[0106] Specific enthalpy h of subcooled or saturated liquid refrigerant f =a3*t*t+b3*t+c3, where a3, b3, and c3 are values ​​fitted from refrigerant property software. For example, for R32 refrigerant, the saturated liquid enthalpy h of the second heat exchanger 9. e_h_f =0.0039*t e_h *t e_h +1.7246*t e_h +200.06. That is to say, the saturated liquid enthalpy h of the second heat exchanger 9... e_h_f =f(t) e_h ).

[0107] In some embodiments, the control unit 104 determines the latent heat of phase change of the first indoor heat exchanger based on the tube temperature of the first indoor heat exchanger. Specifically, the control unit 104 is further configured to determine the latent heat of phase change of the first indoor heat exchanger as the sum of the product of the square of the tube temperature of the first indoor heat exchanger and a tenth preset calculation coefficient, the product of the tube temperature of the first indoor heat exchanger and an eleventh preset calculation coefficient, and a twelfth preset calculation coefficient. Wherein, the tenth preset calculation coefficient is such as a4, the eleventh preset calculation coefficient is such as b4, and the twelfth preset calculation coefficient is such as c4. Figure 7 As shown, the control process for reducing the flow noise of the electronic expansion valve in a heat pump air conditioning system further includes: In step 4, the empirical correlation formula and calculation process formula also include:

[0108] latent heat of phase change of refrigerant h fg=a4*t*t+b4*t+c4, where a4, b4, and c4 are values ​​fitted from refrigerant property software. For example, for R32 refrigerant, the latent heat of phase change h of the second heat exchanger 9. e_h_fg =-0.0181*t e_h *t e_h -1.1988*t e_h +313.22. That is to say, the latent heat of phase change h of the second heat exchanger 9. e_h_fg =f(t) e_h ).

[0109] The control unit 104 is further configured to determine the inlet dryness of the third electronic expansion valve (e.g., inlet dryness of the third electronic expansion valve x3) based on the outlet saturated liquid enthalpy of the flash evaporator 6, the saturated liquid enthalpy of the first indoor heat exchanger, and the latent heat of phase change of the first indoor heat exchanger. The specific functions and processing of this control unit 104 are further described in step S240.

[0110] In some embodiments, the control unit 104 determines the inlet dryness of the third electronic expansion valve based on the outlet saturated liquid enthalpy of the flash evaporator 6, the saturated liquid enthalpy of the first indoor heat exchanger, and the latent heat of phase change of the first indoor heat exchanger. Specifically, the control unit 104 is further configured to determine the inlet dryness of the third electronic expansion valve as the ratio of the difference between the outlet saturated liquid enthalpy of the flash evaporator 6 and the saturated liquid enthalpy of the first indoor heat exchanger, and the latent heat of phase change of the first indoor heat exchanger. Figure 7 As shown, the control process for reducing the flow noise of the electronic expansion valve in a heat pump air conditioning system further includes: In step 4, the empirical correlation formula and calculation process formula also include:

[0111] The inlet dryness of the third electronic expansion valve x3 = (h f -h e_h_f ) / h e_h_fg ; where h e_h_f h is the saturated liquid enthalpy of the second heat exchanger. e_h_fg This is the latent heat of phase change in the second heat exchanger 9. In other words, the inlet dryness fraction of the third electronic expansion valve x3 = f(h) f h e_h_f h e_h_fg h f The saturated liquid enthalpy at the outlet of the flash evaporator 6 is specifically the saturated liquid enthalpy at the outlet where the flash evaporator 6 is connected to the second throttling device 7, and can be calculated.

[0112] The control unit 104 is further configured to determine the predicted noise (e.g., the predicted noise Z of the third electronic expansion valve) of the third electronic expansion valve based on the mass flow rate of the third electronic expansion valve and the inlet dryness of the third electronic expansion valve. The specific functions and processing of the control unit 104 are further described in step S250.

[0113] In some embodiments, the control unit 104 determines the predicted noise of the third electronic expansion valve based on the mass flow rate and the inlet dryness of the third electronic expansion valve. Specifically, the control unit 104 is further configured to determine the predicted noise of the third electronic expansion valve as the sum of a thirteenth preset calculation factor multiple of the square of the mass flow rate of the third electronic expansion valve, a fourteenth preset calculation factor multiple of the mass flow rate of the third electronic expansion valve, a fifteenth preset calculation factor multiple of the inlet dryness of the third electronic expansion valve, and a sixteenth preset calculation factor. Wherein, the thirteenth preset calculation factor is such as a, the fourteenth preset calculation factor is such as b, the fifteenth preset calculation factor is such as c, and the sixteenth preset calculation factor is such as d. Figure 7 As shown, the control process for reducing the flow noise of the electronic expansion valve in a heat pump air conditioning system further includes: In step 4, the empirical correlation formula and calculation process formula also include:

[0114] The predicted noise of the third electronic expansion valve is Z=a*G3 2 +b*G3+c*x3+d, where the range of values ​​for a is -6.3*10 -7 ~0, the preferred value is -2.38*10 -7 The value of b is in the range of 3.3 * 10. -3 ~8.5*10 -3 The preferred value is 5.86*10 -3 The value of c ranges from 0 to 250, with a preferred value of 25.63; the value of d ranges from -15 to 17, with a preferred value of 0.873; G3 is the maximum mass flow rate inside the electronic expansion valve, and x3 is the inlet dryness of the third electronic expansion valve. In other words, the predicted noise of the third electronic expansion valve is Z = f(G3, x3).

[0115] This invention addresses the flow noise problem of the electronic expansion valve on the indoor unit side of a three-pipe dual-temperature parallel compression system and similar multi-electronic expansion valve systems. A novel control scheme is proposed that can reduce the flow noise of the electronic expansion valve while maintaining the energy efficiency of the heat pump air conditioning system, thereby improving indoor comfort. The proposed control scheme makes reasonable assumptions and empirical fittings regarding the potential relationships between the system state parameters and refrigerant properties of the heat pump air conditioning system. Using temperature measurement data from various temperature sensing points in the heat pump air conditioning system, it accurately calculates the maximum mass flow rate and inlet dryness of the electronic expansion valve on the indoor unit side. By controlling the opening degree of the electronic expansion valve in conjunction with the compressor frequency, the maximum mass flow rate within the valve is reduced, thereby lowering the noise.

[0116] The control unit 104 is further configured to adjust the frequency of the compressor, or adjust the opening degree of the second electronic expansion valve and the third electronic expansion valve, based on the predicted noise of the third electronic expansion valve and the exhaust superheat of the compressor, to reduce the actual noise of the third electronic expansion valve. The specific functions and processing of this control unit 104 are further described in step S160.

[0117] The present invention proposes a scheme for real-time calculation of the maximum mass flow rate and inlet dryness of the electronic expansion valve based on system detection parameters. It also proposes a fitting correlation between the total noise value of the electronic expansion valve and its main influencing parameters, such as the maximum mass flow rate and inlet dryness. Furthermore, it proposes a control scheme that combines the electronic expansion valve with the compressor frequency to reduce the maximum mass flow rate and ultimately reduce the noise of the electronic expansion valve. This approach can reduce the flow noise of the electronic expansion valve while taking into account the energy efficiency of the heat pump air conditioning system, thereby improving indoor comfort.

[0118] In some embodiments, the control unit 104 adjusts the frequency of the compressor, or adjusts the opening degree of the second electronic expansion valve and the third electronic expansion valve, based on the predicted noise of the third electronic expansion valve and the discharge superheat of the compressor, including:

[0119] The control unit 104 is further configured to determine whether the predicted noise of the third electronic expansion valve is greater than or equal to a preset noise threshold; wherein, the preset noise threshold is as follows: b For details on the specific functions and processing of the control unit 104, please refer to step S310.

[0120] The control unit 104 is further configured to, if it is determined that the predicted noise of the third electronic expansion valve is less than a preset noise threshold, control the heat pump air conditioning system to maintain its current operation, that is, control the heat pump air conditioning system to continue operating according to the current control parameters. The specific functions and processing of this control unit 104 are further described in step S320.

[0121] The control unit 104 is further configured to, if it is determined that the predicted noise of the third electronic expansion valve is greater than or equal to a preset noise threshold, adjust the frequency of the compressor, or adjust the opening degree of the second electronic expansion valve and the opening degree of the third electronic expansion valve according to the exhaust superheat of the compressor. The specific functions and processing of this control unit 104 are further described in step S330.

[0122] like Figure 7 As shown, the control process for reducing the flow noise of the electronic expansion valve in a heat pump air conditioning system also includes: Step 5, determining whether the predicted noise Z of the third electronic expansion valve is satisfied. b If yes, proceed to step 6; otherwise, if the predicted noise Z of the third electronic expansion valve is less than Z... b If the noise level is low and will not affect indoor comfort, then all control parameters remain unchanged. Among them, Z... b The value range is 25-40 dB(A), where dB(A) represents decibels and A represents weighted sound.

[0123] Step 6: If the predicted noise Z of the third electronic expansion valve ≥ Z b If the noise level is deemed to be affecting indoor comfort, then the next step for adjustment and control is executed, namely step 7, to determine whether the compressor's exhaust superheat d is met. t_dis ≥d c .

[0124] In this invention, a three-pipe, dual-temperature parallel compression system is employed. The indoor heat exchanger is divided into two heat exchangers with different evaporation temperatures, utilizing their cascaded heat exchange effect. The inlet of the indoor electronic expansion valve is in a two-phase state to varying degrees, which is relatively easy to generate flow noise. The method involves calculating the electronic expansion valve noise in real time using system detection parameters and reducing the noise by adjusting system parameters. Specifically, this method correlates the intangible noise with mass flow rate and dryness, making the complex problem concrete. By controlling the opening of the electronic expansion valve in conjunction with the compressor frequency, the maximum mass flow rate within the valve is reduced, thereby reducing noise. However, related solutions that add a subcooler controlled by the electronic expansion valve to ensure subcooling at the indoor unit valve inlet prevents it from entering the two-phase liquid flow noise range have certain limitations and may not be effective under harsh operating conditions or when there is partial refrigerant leakage.

[0125] In some embodiments, the control unit 104 adjusts the frequency of the compressor, or adjusts the opening degree of the second electronic expansion valve and the third electronic expansion valve, based on the compressor's exhaust superheat, including:

[0126] The control unit 104 is further configured to determine whether the exhaust superheat of the compressor is greater than or equal to a preset superheat threshold; wherein, the preset superheat threshold is as follows: c For details on the specific functions and processing of the control unit 104, please refer to step S410.

[0127] The control unit 104 is further configured to, if it is determined that the exhaust superheat of the compressor is greater than or equal to a preset superheat threshold, control the compressor frequency to decrease from the current value to a set frequency, and then return to re-determine whether the difference between the indoor ambient temperature and the set temperature of the heat pump air conditioning system is greater than or equal to a preset temperature threshold. The specific functions and processing of this control unit 104 are further described in step S420.

[0128] The control unit 104 is further configured to, if it is determined that the exhaust superheat of the compressor is less than a preset superheat threshold, control the opening of the second electronic expansion valve to decrease by a first preset opening based on the current value, and control the opening of the third electronic expansion valve to decrease by a second preset opening based on the current value, and then return to re-determine whether the difference between the indoor ambient temperature and the set temperature of the heat pump air conditioning system is greater than or equal to the preset temperature threshold. The specific functions and processing of this control unit 104 are also described in step S430. Figure 7 As shown, the control process for reducing the flow noise of the electronic expansion valve in a heat pump air conditioning system also includes: Step 7, determining whether the compressor's exhaust superheat d is met. t_dis ≥d c If yes, proceed to step 8; otherwise, proceed to step 9. Where d c The value range is 10-25℃.

[0129] Step 8: If the compressor's exhaust superheat d is satisfied... t_dis ≥d c If this happens, the compressor's operating frequency f is reduced, and then the process returns to step 3. Here, the compressor's exhaust superheat d... t_dis , is the exhaust temperature t dis Based on calculations.

[0130] Step 9: If the compressor's exhaust superheat d is not met... t_dis ≥d c Then, decrease the opening degree B2 of the second electronic expansion valve and increase the opening degree B3 of the third electronic expansion valve, and then return to step 3.

[0131] In this invention, the total noise value of the electronic expansion valve is correlated with its main influencing parameters, such as the maximum mass flow rate within the valve and the inlet dryness (i.e., the dryness of the inlet). When the fitted predicted total noise value is higher than a certain set value, the flow noise is considered too high. The noise is reduced by adjusting system parameters to decrease the maximum mass flow rate within the valve. Specific methods include reducing the compressor operating frequency to decrease the refrigerant flow rate, thereby reducing the maximum mass flow rate within the valve; reducing the outlet superheat of the third heat exchanger and increasing the outlet superheat of the second heat exchanger to reduce the evaporation temperature difference between the two heat exchangers, i.e., reducing the pressure difference of the third electronic expansion valve, thereby reducing the maximum mass flow rate within the valve; and so on. By controlling the opening of the electronic expansion valve in conjunction with the compressor frequency, the maximum mass flow rate within the valve is reduced, thus lowering the noise.

[0132] Since the processing and functions implemented by the device in this embodiment are basically the same as the embodiments, principles and examples of the aforementioned methods, any details not covered in the description of this embodiment can be found in the relevant descriptions in the aforementioned embodiments, and will not be repeated here.

[0133] According to an embodiment of the present invention, a heat pump air conditioning system corresponding to a control device for a heat pump air conditioning system is also provided. This heat pump air conditioning system may include: the control device for the heat pump air conditioning system described above.

[0134] Since the processing and functions implemented by the heat pump air conditioning system in this embodiment are basically the same as the embodiments, principles and examples of the aforementioned devices, any details not covered in this embodiment can be found in the relevant descriptions in the aforementioned embodiments, and will not be repeated here.

[0135] According to an embodiment of the present invention, a computer program product corresponding to a heat pump air conditioning system is also provided, including a computer program that, when executed by a processor, implements the steps of the control method for the heat pump air conditioning system described above.

[0136] Since the processing and functions implemented by the product in this embodiment are basically the same as the embodiments, principles and examples of the aforementioned heat pump air conditioning system, any details not covered in this embodiment can be found in the relevant descriptions in the aforementioned embodiments, and will not be repeated here.

[0137] According to an embodiment of the present invention, a storage medium corresponding to a control method for a heat pump air conditioning system is also provided. The storage medium includes a stored program, wherein, when the program is executed, the device where the storage medium is located executes the steps of the control method for the heat pump air conditioning system described above.

[0138] Since the processing and functions implemented by the storage medium in this embodiment are basically the same as the embodiments, principles and examples of the aforementioned methods, any details not covered in this embodiment can be found in the relevant descriptions in the aforementioned embodiments, and will not be repeated here.

[0139] In summary, it is readily understood by those skilled in the art that, without conflict, the aforementioned advantageous methods can be freely combined and superimposed.

[0140] The above description is merely an embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of the claims of the present invention.

Claims

1. A control method for a heat pump air conditioning system, characterized in that, The heat pump air conditioning system includes a compressor, an outdoor heat exchanger, two indoor heat exchangers, and a flash evaporator (6). The two indoor heat exchangers include a first indoor heat exchanger and a second indoor heat exchanger. A first electronic expansion valve is provided between the outdoor heat exchanger and the flash evaporator (6), a second electronic expansion valve is provided between the flash evaporator (6) and the two indoor heat exchangers, and a third electronic expansion valve is provided between the second electronic expansion valve and the second indoor heat exchanger, and on the pipeline where the second indoor heat exchanger is located. The control method of the heat pump air conditioning system includes: After the heat pump air conditioning system is turned on in cooling mode, the opening degree of the first electronic expansion valve, the opening degree of the second electronic expansion valve, and the opening degree of the third electronic expansion valve are all controlled to their respective set values. After the heat pump air conditioning system has been running in cooling mode for a set time, the indoor ambient temperature of the heat pump air conditioning system, the pipe temperature of the first indoor heat exchanger, the pipe temperature of the second indoor heat exchanger, the exhaust superheat of the compressor, and the outlet saturated liquid enthalpy of the flash evaporator (6) are obtained according to a set cycle. Determine whether the difference between the indoor ambient temperature and the set temperature of the heat pump air conditioning system is greater than or equal to a preset temperature threshold. If it is determined that the difference between the indoor ambient temperature of the heat pump air conditioning system and the set temperature is greater than or equal to the preset temperature threshold, then the heat pump air conditioning system is controlled to maintain the current operation. If it is determined that the difference between the indoor ambient temperature and the set temperature of the heat pump air conditioning system is less than the preset temperature threshold, then the predicted noise of the third electronic expansion valve is determined based on the pipe temperature of the first indoor heat exchanger, the pipe temperature of the second indoor heat exchanger, and the outlet saturated liquid enthalpy of the flash evaporator (6). Based on the predicted noise of the third electronic expansion valve and the exhaust superheat of the compressor, adjust the frequency of the compressor, or adjust the opening of the second electronic expansion valve and the opening of the third electronic expansion valve. The predicted noise of the third electronic expansion valve is determined based on the tube temperature of the first indoor heat exchanger, the tube temperature of the second indoor heat exchanger, and the outlet saturated liquid enthalpy of the flash evaporator (6), including: The inlet and outlet pressure difference of the third electronic expansion valve is determined based on the tube temperature of the first indoor heat exchanger and the tube temperature of the second indoor heat exchanger; and the inlet saturated liquid density of the third electronic expansion valve is determined based on the tube temperature of the first indoor heat exchanger. The mass flow rate of the third electronic expansion valve is determined based on the inlet and outlet pressure difference of the third electronic expansion valve and the inlet saturated liquid density of the third electronic expansion valve. The saturated liquid enthalpy of the first indoor heat exchanger is determined based on the tube temperature of the first indoor heat exchanger; and the latent heat of phase change of the first indoor heat exchanger is determined based on the tube temperature of the first indoor heat exchanger. The inlet dryness of the third electronic expansion valve is determined based on the outlet saturated liquid enthalpy of the flash evaporator (6), the saturated liquid enthalpy of the first indoor heat exchanger, and the latent heat of phase change of the first indoor heat exchanger. The predicted noise of the third electronic expansion valve is determined based on the mass flow rate of the third electronic expansion valve and the inlet dryness of the third electronic expansion valve.

2. The control method for a heat pump air conditioning system according to claim 1, characterized in that, in, The inlet and outlet pressure difference of the third electronic expansion valve is determined based on the tube temperatures of the first and second indoor heat exchangers, including: The difference between the square of the tube temperature of the first indoor heat exchanger and the square of the tube temperature of the second indoor heat exchanger is recorded as the first difference, and the difference between the tube temperature of the first indoor heat exchanger and the tube temperature of the second indoor heat exchanger is recorded as the second difference. The sum of the first preset calculation coefficient multiple of the first difference and the second preset calculation coefficient multiple of the second difference is determined as the inlet and outlet pressure difference of the third electronic expansion valve. And / or, Determining the inlet saturated liquid density of the third electronic expansion valve based on the tube temperature of the first indoor heat exchanger includes: The sum of the square of the tube temperature of the first indoor heat exchanger, the third preset calculation factor, the fourth preset calculation factor, and the fifth preset calculation factor is determined as the inlet saturated liquid density of the third electronic expansion valve. And / or, The mass flow rate of the third electronic expansion valve is determined based on the inlet and outlet pressure difference and the inlet saturated liquid density of the third electronic expansion valve, including: The mass flow rate of the third electronic expansion valve is determined by multiplying the half-power of the inlet-outlet pressure difference of the third electronic expansion valve, the inlet saturated liquid density of the third electronic expansion valve, and the sixth preset calculation coefficient.

3. The control method for a heat pump air conditioning system according to claim 1, characterized in that, in, Determining the saturated liquid enthalpy of the first indoor heat exchanger based on the tube temperature of the first indoor heat exchanger includes: The product of the square of the tube temperature of the first indoor heat exchanger and the seventh preset calculation coefficient, the product of the tube temperature of the first indoor heat exchanger and the eighth preset calculation coefficient, and the sum of the ninth preset calculation coefficient are determined as the saturated liquid enthalpy of the first indoor heat exchanger. And / or, Based on the tube temperature of the first indoor heat exchanger, the latent heat of phase change of the first indoor heat exchanger is determined, including: The product of the square of the tube temperature of the first indoor heat exchanger and the tenth preset calculation coefficient, the product of the tube temperature of the first indoor heat exchanger and the eleventh preset calculation coefficient, and the sum of the twelfth preset calculation coefficient are determined as the latent heat of phase change of the first indoor heat exchanger. And / or, The inlet dryness of the third electronic expansion valve is determined based on the outlet saturated liquid enthalpy of the flash evaporator (6), the saturated liquid enthalpy of the first indoor heat exchanger, and the latent heat of phase change of the first indoor heat exchanger, including: The difference between the outlet saturated liquid enthalpy of the flash evaporator (6) and the saturated liquid enthalpy of the first indoor heat exchanger, and the ratio of the latent heat of phase change of the first indoor heat exchanger, are determined as the inlet dryness of the third electronic expansion valve. And / or, The predicted noise of the third electronic expansion valve is determined based on the mass flow rate and the inlet dryness of the third electronic expansion valve, including: The sum of the thirteenth preset calculation factor multiple of the square of the mass flow rate of the third electronic expansion valve, the fourteenth preset calculation factor multiple of the mass flow rate of the third electronic expansion valve, the fifteenth preset calculation factor multiple of the inlet dryness of the third electronic expansion valve, and the sixteenth preset calculation factor is determined as the predicted noise of the third electronic expansion valve.

4. The control method for a heat pump air conditioning system according to any one of claims 1 to 3, characterized in that, Adjusting the compressor frequency, or adjusting the opening degree of the second and third electronic expansion valves, based on the predicted noise of the third electronic expansion valve and the compressor's exhaust superheat, includes: Determine whether the predicted noise of the third electronic expansion valve is greater than or equal to a preset noise threshold; If the predicted noise of the third electronic expansion valve is determined to be less than the preset noise threshold, the heat pump air conditioning system is controlled to maintain its current operation. If the predicted noise of the third electronic expansion valve is determined to be greater than or equal to a preset noise threshold, then the frequency of the compressor is adjusted according to the exhaust superheat of the compressor, or the opening of the second electronic expansion valve and the opening of the third electronic expansion valve are adjusted.

5. The control method for a heat pump air conditioning system according to claim 4, characterized in that, Adjusting the compressor frequency, or adjusting the opening of the second electronic expansion valve and the third electronic expansion valve, based on the compressor's exhaust superheat, includes: Determine whether the exhaust superheat of the compressor is greater than or equal to a preset superheat threshold. If it is determined that the superheat of the compressor's exhaust is greater than or equal to a preset superheat threshold, the compressor's frequency is controlled to decrease from the current value by a set frequency, and then the process is repeated to re-determine whether the difference between the indoor ambient temperature and the set temperature of the heat pump air conditioning system is greater than or equal to a preset temperature threshold. If it is determined that the superheat of the compressor's exhaust is less than a preset superheat threshold, then the opening of the second electronic expansion valve is reduced by a first set opening based on the current value, and the opening of the third electronic expansion valve is reduced by a second set opening based on the current value. Then, the process returns to re-determine whether the difference between the indoor ambient temperature and the set temperature of the heat pump air conditioning system is greater than or equal to the preset temperature threshold.

6. A control device for a heat pump air conditioning system that uses the control method of the heat pump air conditioning system as described in claim 1 to control the heat pump air conditioning system, characterized in that, The heat pump air conditioning system includes a compressor, an outdoor heat exchanger, two indoor heat exchangers, and a flash evaporator (6). The two indoor heat exchangers include a first indoor heat exchanger and a second indoor heat exchanger. A first electronic expansion valve is provided between the outdoor heat exchanger and the flash evaporator (6), a second electronic expansion valve is provided between the flash evaporator (6) and the two indoor heat exchangers, and a third electronic expansion valve is provided between the second electronic expansion valve and the second indoor heat exchanger, and on the pipeline where the second indoor heat exchanger is located. The control device of the heat pump air conditioning system includes: The control unit is configured to, after the heat pump air conditioning system is turned on in cooling mode, control the opening degree of the first electronic expansion valve, the opening degree of the second electronic expansion valve, and the opening degree of the third electronic expansion valve to their respective set values. The acquisition unit is configured to acquire the indoor ambient temperature of the heat pump air conditioning system, the pipe temperature of the first indoor heat exchanger, the pipe temperature of the second indoor heat exchanger, the exhaust superheat of the compressor, and the outlet saturated liquid enthalpy of the flash evaporator (6) after the heat pump air conditioning system has been running in cooling mode for a set time, according to a set cycle. The control unit is also configured to determine whether the difference between the indoor ambient temperature of the heat pump air conditioning system and the set temperature is greater than or equal to a preset temperature threshold. The control unit is further configured to control the heat pump air conditioning system to maintain its current operation if it is determined that the difference between the indoor ambient temperature of the heat pump air conditioning system and the set temperature is greater than or equal to a preset temperature threshold. The control unit is further configured to determine the predicted noise of the third electronic expansion valve based on the pipe temperature of the first indoor heat exchanger, the pipe temperature of the second indoor heat exchanger, and the outlet saturated liquid enthalpy of the flash evaporator (6) if it is determined that the difference between the indoor ambient temperature of the heat pump air conditioning system and the set temperature is less than a preset temperature threshold. The control unit is further configured to adjust the frequency of the compressor, or adjust the opening degree of the second electronic expansion valve and the opening degree of the third electronic expansion valve, based on the predicted noise of the third electronic expansion valve and the exhaust superheat of the compressor.

7. A heat pump air conditioning system, characterized in that, include: The control device for the heat pump air conditioning system as described in claim 6.

8. A storage medium, characterized in that, The storage medium includes a stored program, wherein, when the program is executed, the device containing the storage medium is controlled to perform the control method of the heat pump air conditioning system according to any one of claims 1 to 5.

9. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by the processor, it implements the steps of the control method for the heat pump air conditioning system according to any one of claims 1 to 5.

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