A control method and device of an air conditioner, the air conditioner, a storage medium and a program product

Abstract

The application discloses a kind of control method, device, air conditioner of air conditioner, storage medium and computer program product, air conditioner has inner fan, parallel first indoor heat exchanger and second indoor heat exchanger, two indoor heat exchangers are respectively provided with first branch throttling component and second branch throttling component between air conditioner throttling component;The method comprises: according to indoor dry ball temperature determines by PD feedback control strategy or heat load and humidity load control strategy control compressor operating frequency;According to indoor dew point temperature determines by PD feedback control strategy or heat load and humidity load control strategy control inner fan speed;According to the suction superheat of first indoor heat exchanger second indoor heat exchanger, respectively determine by PD feedback control strategy or fitting formula control strategy, control the opening of first branch throttling component and second throttling component.The scheme, by combining PD feedback and heat and humidity load control strategy control air conditioner operation, ensure system accurate temperature control and humidity control and stable and efficient operation.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of air conditioners, and particularly relates to an air conditioner control method and device, an air conditioner, a storage medium and a computer program product. BACKGROUND

[0002] For air conditioners to control temperature and humidity simultaneously, a multi-split parallel air conditioner system has better energy efficiency performance compared to a conventional air conditioner system with one outdoor unit and one indoor unit. Related solutions propose an artificial intelligence neural network control method based on a load model, a PID type fuzzy logic control method based on a weight rule table, and other air conditioner temperature and humidity control methods, but these methods are only limited to conventional air conditioner systems and are not applicable to parallel air conditioner systems.

[0003] The above content is only used to assist in understanding the technical solutions of the present application and does not represent an acknowledgement that the above content is prior art. SUMMARY

[0004] The present application aims to provide an air conditioner control method and device, an air conditioner, a storage medium and a computer program product to solve the problem that parallel air conditioner systems cannot effectively control temperature and humidity simultaneously in related solutions, and to achieve the effect of controlling the operating state of the compressor, the indoor fan and the throttling component in the parallel air conditioner system by combining PD feedback and heat and humidity load control strategies, ensuring accurate temperature and humidity control and stable and efficient operation of the system.

[0005] The application provides a control method of an air conditioner, the air conditioner has a first indoor heat exchanger and a second indoor heat exchanger arranged in parallel; a first branch throttling component is arranged between the first indoor heat exchanger and a throttling component of the air conditioner, and a second branch throttling component is arranged between the second indoor heat exchanger and the throttling component of the air conditioner; an indoor fan is arranged at the first indoor heat exchanger and the second indoor heat exchanger; the method comprises the following steps: after the air conditioner starts to operate, an indoor dry-bulb temperature, an indoor dew-point temperature, suction superheat of the first indoor heat exchanger and suction superheat of the second indoor heat exchanger are obtained; a control strategy for controlling an operating frequency of a compressor of the air conditioner is determined according to the size of the indoor dry-bulb temperature, so as to control the compressor to operate; a control strategy for controlling a rotating speed of the indoor fan is determined according to the size of the indoor dew-point temperature, so as to control the indoor fan to operate; control strategies for controlling the opening of the first branch throttling component and the opening of the second branch throttling component are respectively determined according to the size of the suction superheat of the first indoor heat exchanger and the suction superheat of the second indoor heat exchanger, so as to control the first branch throttling component and the second branch throttling component to operate; wherein the control strategy for controlling the operating frequency of the compressor of the air conditioner comprises a PD feedback control strategy, a heat load and a humidity load control strategy; the control strategy for controlling the rotating speed of the indoor fan comprises a PD feedback control strategy, a heat load and a humidity load control strategy; and the control strategy for controlling the opening of the first branch throttling component and the opening of the second branch throttling component comprises a PD feedback control strategy and a fitting formula control strategy.

[0006] In some embodiments, the PD feedback control strategy comprises: controlling the operation of the compressor according to a result of calculating the operating frequency of the compressor according to a first formula, controlling the operation of the inner fan according to a result of calculating the rotating speed of the inner fan according to a second formula, controlling the operation of the first branch throttling component according to a result of calculating the opening of the first branch throttling component according to a third formula, and controlling the operation of the second branch throttling component according to a result of calculating the opening of the second branch throttling component according to a fourth formula; the thermal load and humidity load control strategy comprises: controlling the operation of the compressor according to a result of calculating the operating frequency of the compressor according to a fifth formula, and controlling the operation of the inner fan according to a result of calculating the rotating speed of the inner fan according to a sixth formula; the control strategy for controlling the operating frequency of the compressor of the air conditioner according to the magnitude of the indoor dry-bulb temperature comprises: judging the magnitude of the absolute value of the difference between the indoor dry-bulb temperature and the indoor set temperature; if the absolute value of the difference between the indoor dry-bulb temperature and the indoor set temperature is less than a first temperature difference, the control strategy for controlling the operating frequency of the compressor of the air conditioner is the result of controlling the operation of the compressor according to the operating frequency of the compressor calculated according to the first formula in the PD feedback control; if the absolute value of the difference between the indoor dry-bulb temperature and the indoor set temperature is greater than or equal to the first temperature difference, the control strategy for controlling the operating frequency of the compressor of the air conditioner is the result of controlling the operation of the compressor according to the operating frequency of the compressor calculated according to the fifth formula in the thermal load and humidity load control; and / or, the control strategy for controlling the rotating speed of the inner fan according to the magnitude of the indoor dew-point temperature comprises: judging the magnitude of the absolute value of the difference between the indoor dew-point temperature and the indoor set dew-point temperature; if the absolute value of the difference between the indoor dew-point temperature and the indoor set dew-point temperature is less than a second temperature difference, the control strategy for controlling the rotating speed of the inner fan is the result of controlling the operation of the inner fan according to the rotating speed of the inner fan calculated according to the second formula in the PD feedback control; if the absolute value of the difference between the indoor dew-point temperature and the indoor set dew-point temperature is greater than or equal to the second temperature difference, the control strategy for controlling the rotating speed of the inner fan is the result of controlling the operation of the inner fan according to the rotating speed of the inner fan calculated according to the sixth formula in the thermal load and humidity load control.

[0007] In some embodiments, according to the size of the suction superheat degree of the first indoor heat exchanger and the suction superheat degree of the second indoor heat exchanger, the control strategy for controlling the opening degree of the first branch throttling component and the opening degree of the second branch throttling component is determined respectively, including: judging the size of the absolute value of the difference between the suction superheat degree of the first indoor heat exchanger and the first set suction superheat degree, if the absolute value of the difference between the suction superheat degree of the first indoor heat exchanger and the first set suction superheat degree is less than the preset suction superheat degree difference, the control strategy for controlling the opening degree of the first branch throttling component is that the result of calculating the opening degree of the first branch throttling component according to the third formula in the PD feedback control controls the operation of the first branch throttling component; if the absolute value of the difference between the suction superheat degree of the first indoor heat exchanger and the first set suction superheat degree is greater than or equal to the preset suction superheat degree difference, the control strategy for controlling the opening degree of the first branch throttling component is the fitting formula control strategy; and / or, judging the size of the absolute value of the difference between the suction superheat degree of the second indoor heat exchanger and the second set suction superheat degree; if the absolute value of the difference between the suction superheat degree of the second indoor heat exchanger and the second set suction superheat degree is less than the preset suction superheat degree difference, the control strategy for controlling the opening degree of the second branch throttling component is that the result of calculating the opening degree of the second branch throttling component according to the fourth formula in the PD feedback control controls the operation of the second branch throttling component; if the absolute value of the difference between the suction superheat degree of the second indoor heat exchanger and the second set suction superheat degree is greater than or equal to the preset suction superheat degree difference, the control strategy for controlling the opening degree of the second branch throttling component is the fitting formula control strategy; wherein the fitting formula control strategy for controlling the opening degree of the first branch throttling component and the opening degree of the second branch throttling component is the same; the fitting formula control strategy is to obtain the mass flow rate of the first branch throttling component and the second branch throttling component according to the seventh calculation formula, and to obtain the opening degree of the first branch throttling component and the opening degree of the second branch throttling component according to the preset corresponding relationship between the mass flow rate and the opening degree; the seventh calculation formula is:

[0008] Mr=f(F,ηv,tsuc_obj,tevap);

[0009] In the formula, Mr is the mass flow rate of the first branch throttling component and the second branch throttling component; F is the operating frequency of the compressor; ηv is the volumetric efficiency; if Mr is the mass flow rate of the first branch throttling component, tsuc_obj is the target suction superheat degree of the first indoor heat exchanger, and tevap is the evaporation temperature of the first indoor heat exchanger; if Mr is the mass flow rate of the second branch throttling component, tsuc_obj is the target suction superheat degree of the second indoor heat exchanger, and tevap is the evaporation temperature of the second indoor heat exchanger.

[0010] In some embodiments, the first formula is:

[0011] F(n+1) = F(n) + Kd*(Kp1*△Tdr + Ki1*△Tdr) + Kw*(Kp2*△Tdp + Ki1*△Tdp);

[0012] The second formula is:

[0013] C(n+1) = C(n) + Kp2*△Tdp + Ki2*△Tdp;

[0014] In the formula, F(n+1), F(n) are the operating frequency of the compressor, C(n+1), C(n) are the speed of the inner fan, n is the cycle number; △Tdr is the difference between the indoor dry-bulb temperature and the indoor set temperature; δTdr is the deviation rate between the indoor dry-bulb temperature and the indoor set temperature; △Tdp is the difference between the indoor dew-point temperature and the indoor target dew-point temperature; δTdp is the deviation rate between the indoor dew-point temperature and the indoor target dew-point temperature; Kd, Kp1, Kp2, Ki1, Ki2, Kw are all coefficients.

[0015] In some embodiments, the third formula is:

[0016] B1(n+1) = B1(n) + Kp3*△sh1 + Ki3*△sh1;

[0017] The fourth formula is:

[0018] B2(n+1) = B2(n) + Kp4*△sh2 + Ki4*△sh2;

[0019] In the formula, B1(n), B1(n+1) are the opening degree of the first branch throttling component, B2(n), B2(n+1) are the opening degree of the second branch throttling component, n is the cycle number; △sh1 is the difference between the suction superheat of the first indoor heat exchanger and the first set suction superheat; δsh1 is the deviation rate between the suction superheat of the first indoor heat exchanger and the first set suction superheat; △sh2 is the difference between the suction superheat of the second indoor heat exchanger and the second set suction superheat; δsh2 is the deviation rate between the suction superheat of the second indoor heat exchanger and the second set suction superheat; Kp3, Ki3, Kp4, Ki4 are all coefficients.

[0020] In some embodiments, the fifth formula is:

[0021] F0 = z1 + a1*Qtot + b1*SHR + c1*Qtot 2 + d1*SHR 2 + e1*Qtot*SHR;

[0022] The sixth formula is:

[0023] C0=z2+a2*Qtot+b2*SHR+c2*Qtot 2 +d2*SHR 2 +e2*Qtot*SHR;

[0024] In the formula, F0 is the operating frequency of the compressor; C0 is the rotating speed of the inner fan; z1, a1, b1, c1, d1, e1, z2, a2, b2, c2, d2, and e2 are coefficients; Qtot is the total refrigerating capacity of the air conditioner, Qtot=Qlat+Qsen; SHR is the sensible heat ratio, SHR=Qsen / Qtot; Qlat is the wet load; and Qsen is the heat load.

[0025] To match the above method, the application further provides a control device of an air conditioner, the air conditioner having a first indoor heat exchanger and a second indoor heat exchanger arranged in parallel; a first branch throttling component is arranged between the first indoor heat exchanger and a throttling component of the air conditioner, and a second branch throttling component is arranged between the second indoor heat exchanger and the throttling component of the air conditioner; an inner fan is arranged at the first indoor heat exchanger and the second indoor heat exchanger; the device comprises: an acquisition unit configured to acquire an indoor dry-bulb temperature, an indoor dew-point temperature, a suction superheat of the first indoor heat exchanger, and a suction superheat of the second indoor heat exchanger after the air conditioner starts operating; a control unit configured to determine a control strategy for controlling the operating frequency of a compressor of the air conditioner according to the size of the indoor dry-bulb temperature, so as to control the compressor to operate; the control unit is configured to determine a control strategy for controlling the rotating speed of the inner fan according to the size of the indoor dew-point temperature, so as to control the inner fan to operate; the control unit is configured to determine a control strategy for controlling the opening degree of the first branch throttling component and the opening degree of the second branch throttling component according to the sizes of the suction superheat of the first indoor heat exchanger and the suction superheat of the second indoor heat exchanger, so as to control the first branch throttling component and the second branch throttling component to operate; wherein the control strategy for controlling the operating frequency of the compressor of the air conditioner comprises a PD feedback control strategy and a heat load and wet load control strategy; the control strategy for controlling the rotating speed of the inner fan comprises a PD feedback control strategy and a heat load and wet load control strategy; and the control strategy for controlling the opening degree of the first branch throttling component and the opening degree of the second branch throttling component comprises a PD feedback control strategy and a fitting formula control strategy.

[0026] In some embodiments, the PD feedback control strategy comprises: controlling the operation of the compressor according to a result of calculating the operation frequency of the compressor according to a first formula, controlling the operation of the inner fan according to a result of calculating the rotating speed of the inner fan according to a second formula, controlling the operation of the first branch throttling component according to a result of calculating the opening of the first branch throttling component according to a third formula, and controlling the operation of the second branch throttling component according to a result of calculating the opening of the second branch throttling component according to a fourth formula; the thermal load and humidity load control strategy comprises: controlling the operation of the compressor according to a result of calculating the operation frequency of the compressor according to a fifth formula, and controlling the operation of the inner fan according to a result of calculating the rotating speed of the inner fan according to a sixth formula; the control unit determines the control strategy for controlling the operation frequency of the compressor of the air conditioner according to the magnitude of the indoor dry-bulb temperature, which comprises: judging the magnitude of the absolute value of the difference between the indoor dry-bulb temperature and the indoor set temperature; if the absolute value of the difference between the indoor dry-bulb temperature and the indoor set temperature is less than a first temperature difference, the control strategy for controlling the operation frequency of the compressor of the air conditioner is the result of calculating the operation frequency of the compressor according to the first formula in the PD feedback control for controlling the operation of the compressor; if the absolute value of the difference between the indoor dry-bulb temperature and the indoor set temperature is greater than or equal to the first temperature difference, the control strategy for controlling the operation frequency of the compressor of the air conditioner is the result of calculating the operation frequency of the compressor according to the fifth formula in the thermal load and humidity load control for controlling the operation of the compressor; and / or, the control unit determines the control strategy for controlling the rotating speed of the inner fan according to the magnitude of the indoor dew-point temperature, which comprises: judging the magnitude of the absolute value of the difference between the indoor dew-point temperature and the indoor set dew-point temperature; if the absolute value of the difference between the indoor dew-point temperature and the indoor set dew-point temperature is less than a second temperature difference, the control strategy for controlling the rotating speed of the inner fan is the result of calculating the rotating speed of the inner fan according to the second formula in the PD feedback control for controlling the operation of the inner fan; if the absolute value of the difference between the indoor dew-point temperature and the indoor set dew-point temperature is greater than or equal to the second temperature difference, the control strategy for controlling the rotating speed of the inner fan is the result of calculating the rotating speed of the inner fan according to the sixth formula in the thermal load and humidity load control for controlling the operation of the inner fan.

[0027] In some embodiments, the control unit determines the control strategy of controlling the opening degree of the first branch throttling component and the opening degree of the second branch throttling component according to the size of the suction superheat degree of the first indoor heat exchanger and the size of the suction superheat degree of the second indoor heat exchanger, including: judging the size of the absolute value of the difference between the suction superheat degree of the first indoor heat exchanger and the first set suction superheat degree, if the absolute value of the difference between the suction superheat degree of the first indoor heat exchanger and the first set suction superheat degree is less than a preset suction superheat degree difference, the control strategy of controlling the opening degree of the first branch throttling component is that the first branch throttling component is controlled to operate according to the result of calculating the opening degree of the first branch throttling component in the PD feedback control according to the third formula; if the absolute value of the difference between the suction superheat degree of the first indoor heat exchanger and the first set suction superheat degree is greater than or equal to the preset suction superheat degree difference, the control strategy of controlling the opening degree of the first branch throttling component is the fitting formula control strategy; and / or, judging the size of the absolute value of the difference between the suction superheat degree of the second indoor heat exchanger and the second set suction superheat degree; if the absolute value of the difference between the suction superheat degree of the second indoor heat exchanger and the second set suction superheat degree is less than a preset suction superheat degree difference, the control strategy of controlling the opening degree of the second branch throttling component is that the second branch throttling component is controlled to operate according to the result of calculating the opening degree of the second branch throttling component in the PD feedback control according to the fourth formula; if the absolute value of the difference between the suction superheat degree of the second indoor heat exchanger and the second set suction superheat degree is greater than or equal to the preset suction superheat degree difference, the control strategy of controlling the opening degree of the second branch throttling component is the fitting formula control strategy; wherein the fitting formula control strategy of controlling the opening degree of the first branch throttling component and the opening degree of the second branch throttling component is the same; the fitting formula control strategy is to obtain the mass flow rate of the first branch throttling component and the second branch throttling component according to the seventh calculation formula, and to obtain the opening degree of the first branch throttling component and the opening degree of the second branch throttling component according to the preset corresponding relationship between the mass flow rate and the opening degree; the seventh calculation formula is:

[0028] Mr=f(F,ηv,tsuc_obj,tevap);

[0029] In the formula, Mr is the mass flow rate of the first branch throttling component and the second branch throttling component; F is the operating frequency of the compressor; ηv is the volumetric efficiency; if Mr is the mass flow rate of the first branch throttling component, tsuc_obj is the target suction superheat degree of the first indoor heat exchanger, and tevap is the evaporation temperature of the first indoor heat exchanger; if Mr is the mass flow rate of the second branch throttling component, tsuc_obj is the target suction superheat degree of the second indoor heat exchanger, and tevap is the evaporation temperature of the second indoor heat exchanger.

[0030] In some embodiments, the first formula is:

[0031] F(n+1) = F(n) + Kd*(Kp1*△Tdr + Ki1*δTdr) + Kw*(Kp2*△Tdp + Ki1*δTdp);

[0032] The second formula is:

[0033] C(n+1) = C(n) + Kp2*△Tdp + Ki2*δTdp;

[0034] In the formula, F(n+1), F(n) are the operating frequency of the compressor, C(n+1), C(n) are the speed of the inner fan, n is the cycle number; △Tdr is the difference between the indoor dry-bulb temperature and the indoor set temperature; δTdr is the deviation rate between the indoor dry-bulb temperature and the indoor set temperature; △Tdp is the difference between the indoor dew point temperature and the indoor target dew point temperature; δTdp is the deviation rate between the indoor dew point temperature and the indoor target dew point temperature; Kd, Kp1, Kp2, Ki1, Ki2, Kw are all coefficients.

[0035] In some embodiments, the third formula is:

[0036] B1(n+1) = B1(n) + Kp3*△sh1 + Ki3*δsh1;

[0037] The fourth formula is:

[0038] B2(n+1) = B2(n) + Kp4*△sh2 + Ki4*δsh2;

[0039] In the formula, B1(n), B1(n+1) are the opening degree of the first branch throttling component, B2(n), B2(n+1) are the opening degree of the second branch throttling component, n is the cycle number; △sh1 is the difference between the suction superheat of the first indoor heat exchanger and the first set suction superheat; δsh1 is the deviation rate between the suction superheat of the first indoor heat exchanger and the first set suction superheat; △sh2 is the difference between the suction superheat of the second indoor heat exchanger and the second set suction superheat; δsh2 is the deviation rate between the suction superheat of the second indoor heat exchanger and the second set suction superheat; Kp3, Ki3, Kp4, Ki4 are all coefficients.

[0040] In some embodiments, the fifth formula is:

[0041] F0 = z1 + a1*Qtot + b1*SHR + c1*Qtot 2 + d1*SHR 2 + e1*Qtot*SHR;

[0042] The sixth formula is:

[0043] C0=z2+a2*Qtot+b2*SHR+c2*Qtot 2 +d2*SHR 2 +e2*Qtot*SHR;

[0044] In the formula, F0 is the operating frequency of the compressor; C0 is the rotating speed of the inner fan; z1, a1, b1, c1, d1, e1, z2, a2, b2, c2, d2, and e2 are coefficients; Qtot is the total refrigerating capacity of the air conditioner, Qtot=Qlat+Qsen; SHR is the sensible heat ratio, SHR=Qsen / Qtot; Qlat is the wet load; and Qsen is the heat load.

[0045] In order to match the above device, the application further provides an air conditioner, which comprises the above-mentioned control device of the air conditioner.

[0046] In order to match the above method, the application further provides a storage medium, which comprises a stored program, wherein when the program is executed, the device where the storage medium is located performs the above-mentioned control method of the air conditioner.

[0047] In order to match the above method, the application further provides a computer program product, which comprises a computer program, and when the computer program product is executed, the steps of the above-mentioned control method of the air conditioner are realized.

[0048] According to the scheme of the application, the air conditioner has the first indoor heat exchanger and the second indoor heat exchanger connected in parallel, the first indoor heat exchanger is provided with the first branch throttling component between the throttling component of the air conditioner, the second indoor heat exchanger is provided with the second branch throttling component between the throttling component of the air conditioner; after the air conditioner starts to operate, the control strategy for determining the operating frequency of the compressor according to the indoor dry-bulb temperature is the PD feedback control strategy or the heat load and wet load control strategy, the control strategy for determining the rotating speed of the inner fan according to the indoor dew-point temperature is the PD feedback control strategy or the heat load and wet load control strategy, and the control strategy for determining the opening degree of the first branch throttling component and the opening degree of the second branch throttling component according to the suction superheat of the first indoor heat exchanger and the suction superheat of the second indoor heat exchanger is the PD feedback control strategy or the fitting formula control strategy. Therefore, by combining the PD feedback control and the heat and wet load control, the operating states of the compressor, the inner fan, and the throttling component in the parallel air conditioning system are controlled, so that the system can be accurately controlled in temperature and humidity and stably and efficiently operated.

[0049] Other features and advantages of the present application will be set forth in the following description, and in part will become apparent to those skilled in the art from the description, or can be learned by practice of the application.

[0050] The technical solutions of the present application will be further described in detail below with reference to the accompanying drawings and embodiments. BRIEF DESCRIPTION OF DRAWINGS

[0051] Figure 1 Flowchart of an embodiment of the control method of the air conditioner of the present application;

[0052] Figure 2 Structural diagram of an embodiment of the control device of the air conditioner of the present application;

[0053] Figure 3 Structural diagram of the air conditioning system of the present application;

[0054] Figure 4 Flowchart of another embodiment of the control method of the air conditioner of the present application.

[0055] In the embodiments of the present application, the reference signs in the accompanying drawings are as follows:

[0056] 10 - compressor; 11 - first suction port of compressor; 12 - second suction port of compressor; 13 - third suction port of compressor; 14 - discharge port of compressor; 20 - outdoor heat exchanger; 31 - first electronic expansion valve; 40 - flash tank; 32 - first second electronic expansion valve; 33 - second second electronic expansion valve; 51 - first indoor heat exchanger; 52 - second indoor heat exchanger; 102 - acquisition unit; 104 - control unit. DETAILED DESCRIPTION

[0057] In order to make the objectives, technical solutions and advantages of the present application clearer, the technical solutions of the present application will be described clearly and completely below with reference to the specific embodiments of the present application and the corresponding drawings. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present application.

[0058] According to an embodiment of the present application, a control method of an air conditioner is provided, the air conditioner having a first indoor heat exchanger and a second indoor heat exchanger arranged in parallel; a first branch throttling component is arranged between the first indoor heat exchanger and a throttling component of the air conditioner, and a second branch throttling component is arranged between the second indoor heat exchanger and the throttling component of the air conditioner; an indoor fan is arranged at the first indoor heat exchanger and the second indoor heat exchanger.

[0059] The system structure of the air conditioner is as shown in Figure 3As shown, the throttling component of the air conditioner is a primary electronic expansion valve 31, the first branch throttling component is a first secondary electronic expansion valve 32, and the second branch throttling component is a second secondary electronic expansion valve 33. Specifically, the pipeline at the exhaust port 14 of the compressor 10 of the air conditioner sequentially passes through the outdoor heat exchanger 20, the primary electronic expansion valve 31, and is connected to the flash tank 40. The flash tank 40 has two refrigerant outlets, one of which is connected to the third suction port 13 of the compressor, and the other of which is provided with a first branch and a second branch in parallel between the compressor. On the first branch, along the direction from the flash tank 40 to the compressor 10, the first secondary electronic expansion valve 32 and the first indoor heat exchanger 51 are sequentially arranged, and finally connected to the first suction port 11 of the compressor. On the second branch, along the direction from the flash tank 40 to the compressor 10, the second secondary electronic expansion valve 33 and the second indoor heat exchanger 52 are sequentially arranged, and finally connected to the second suction port 12 of the compressor.

[0060] The first indoor heat exchanger and the second indoor heat exchanger are arranged side by side in the same air duct and have an upstream and downstream relationship. Figure 3 In particular, the first indoor heat exchanger 51 is at an upstream position, and the second indoor heat exchanger 52 is at a downstream position.

[0061] As Figure 1 The flowchart of an embodiment of the method of the application is shown. The control method of the air conditioner can include steps S110 to S140.

[0062] At step S110, after the air conditioner starts running, the indoor dry-bulb temperature, the indoor dew-point temperature, the suction superheat of the first indoor heat exchanger, and the suction superheat of the second indoor heat exchanger are obtained.

[0063] At step S120, the control strategy for controlling the operating frequency of the compressor of the air conditioner is determined according to the size of the indoor dry-bulb temperature, to control the operation of the compressor.

[0064] At step S130, the control strategy for controlling the rotating speed of the indoor fan is determined according to the size of the indoor dew-point temperature, to control the operation of the indoor fan.

[0065] At step S140, the control strategies for controlling the opening degree of the first branch throttling component and the opening degree of the second branch throttling component are respectively determined according to the sizes of the suction superheat of the first indoor heat exchanger and the suction superheat of the second indoor heat exchanger, to control the operations of the first branch throttling component and the second branch throttling component.

[0066] The control strategy for controlling the operating frequency of the compressor of the air conditioner includes a PD feedback control strategy, a heat load and a humidity load control strategy; the control strategy for controlling the rotating speed of the inner fan includes a PD feedback control strategy, a heat load and a humidity load control strategy; and the control strategy for controlling the opening degree of the first branch throttling component and the opening degree of the second branch throttling component includes a PD feedback control strategy and a fitting formula control strategy.

[0067] The operation of the air conditioner is divided into a first stage and a second stage. In the first stage, the air conditioner obtains the operating parameters of the air conditioner according to the preset calculation formula according to the collected temperature, humidity and suction superheat degree, and controls the operating frequency of the compressor, the rotating speed of the inner fan and the opening degree of the throttling component. In the second stage, the operating parameters are calculated according to the PD feedback control, the two indoor heat exchangers are coupled to process the sensible heat load and the latent heat load, and the purpose of precise temperature and humidity control and high-efficiency operation of the air conditioning system is achieved. The judgment conditions for selecting the first stage or the second stage for the compressor, the inner fan and the throttling component are different.

[0068] The first-stage electronic expansion valve and the second-stage electronic expansion valve are in linkage control. Specifically, the refrigerant mass flow rate of the first-stage electronic expansion valve is calculated according to the refrigerant mass flow rates of the first and second-stage electronic expansion valves, and the opening degree value is converted according to the relationship between the mass flow rate and the opening degree, and the first-stage electronic expansion valve is controlled according to the opening degree value. The calculation formula is:

[0069] Mr_m=(Mr1+Mr2) / (1-x_ft)。

[0070] In the formula, Mr_m is the mass flow rate of the first-stage electronic expansion valve, Mr1 is the mass flow rate of the first and second-stage electronic expansion valves, Mr2 is the mass flow rate of the second-stage electronic expansion valve, and x_ft is the first-stage throttling flash evaporation dryness, and the calculation formula is as follows:

[0071] x_ft=i*(t_c_o-t_ft_target) / (j-k*t_ft_target)。

[0072] In the formula, i, j and k are pre-stored coefficients determined by experiments, t_c_o is the outlet temperature of the condenser, and t_ft_target is the intermediate temperature target value of the opening degree of the first-stage electronic expansion valve, and the calculation formula is as follows:

[0073] t_ft_target=m*tc_o+n*(tevap1+tevap2)。

[0074] In the formula, m and n are pre-stored coefficients determined by experiments; tc o is the condenser outlet temperature; tevap1 is the evaporation temperature of the first indoor heat exchanger; and tevap2 is the evaporation temperature of the second indoor heat exchanger. The high-pressure path parameters include the condenser outlet temperature tc o, and the low-pressure path parameters include the evaporation temperatures tevap1 and tevap2 of the first and second indoor heat exchangers.

[0075] By determining the intermediate temperature target value of the opening degree of the primary electronic expansion valve according to the evaporation temperatures of all the indoor heat exchangers in the parallel air conditioning system, and combining the mass flow rates of all the secondary electronic expansion valves, the opening degree of the primary electronic expansion valve is obtained, so as to improve the temperature and humidity control effect of the parallel air conditioning system and improve the energy efficiency performance of the system.

[0076] In some embodiments, the PD feedback control strategy includes: controlling the operation of the compressor according to a result of calculating the operating frequency of the compressor according to a first formula, controlling the operation of the indoor fan according to a result of calculating the rotating speed of the indoor fan according to a second formula, controlling the operation of the first branch throttling component according to a result of calculating the opening degree of the first branch throttling component according to a third formula, and controlling the operation of the second branch throttling component according to a result of calculating the opening degree of the second branch throttling component according to a fourth formula; and the thermal load and humidity load control strategy includes: controlling the operation of the compressor according to a result of calculating the operating frequency of the compressor according to a fifth formula, and controlling the operation of the indoor fan according to a result of calculating the rotating speed of the indoor fan according to a sixth formula.

[0077] In some embodiments, in step S120, a specific process of determining the compressor operating frequency control strategy of the air conditioner according to the size of the indoor dry-bulb temperature includes: judging the size of the absolute value of the difference between the indoor dry-bulb temperature and the indoor set temperature; if the absolute value of the difference between the indoor dry-bulb temperature and the indoor set temperature is less than a first temperature difference, the compressor operating frequency control strategy of the air conditioner is controlled to be the result of controlling the operation of the compressor according to the calculation of the operating frequency of the compressor according to the first formula in the PD feedback control; and if the absolute value of the difference between the indoor dry-bulb temperature and the indoor set temperature is greater than or equal to the first temperature difference, the compressor operating frequency control strategy of the air conditioner is controlled to be the result of controlling the operation of the compressor according to the calculation of the operating frequency of the compressor according to the fifth formula in the thermal load and humidity load control.

[0078] For the control of the compressor operating frequency, the air conditioner is first controlled according to the first stage after being turned on, and then whether the second stage control is executed is determined according to the size of the indoor dry-bulb temperature Tin. The first stage is controlled according to the heat load and the humidity load, and the second stage is controlled according to the PD feedback. The second stage is the precise temperature and humidity control logic. The dividing point between the first stage and the second stage is whether the indoor dry-bulb temperature Tin reaches the indoor set temperature T_set. The indoor set temperature T_set is set by the user. The first temperature difference value is used to determine whether the indoor dry-bulb temperature Tin and the indoor set temperature T_set differ greatly, which can be set to 1.5°C. When |Tin-T_set|<1.5°C, the indoor dry-bulb temperature Tin and the indoor set temperature T_set differ slightly, and it is considered that the indoor dry-bulb temperature Tin meets the threshold interval and reaches the condition for PD feedback control; when |Tin-T_set|≥1.5°C, the first stage control is continued to be executed.

[0079] The first formula is:

[0080] F(n+1)=F(n)+Kd*(Kp1*△Tdr+Ki1*δTdr)+Kw*(Kp2*△Tdp+Ki1*δTdp).

[0081] In the formula, F(n+1) and F(n) are the operating frequencies of the compressor, n is the cycle number; △Tdr is the difference between the indoor dry-bulb temperature and the indoor set temperature, that is, △Tdr=|Tin-T_set|; δTdr is the deviation rate between the indoor dry-bulb temperature and the indoor set temperature, that is, δTdr=△Tdr / T_set; △Tdp is the difference between the indoor dew-point temperature and the indoor target dew-point temperature, that is, △Tdp=|Tdp-Tdp_set|; δTdp is the deviation rate between the indoor dew-point temperature and the indoor target dew-point temperature, that is, δTdp=△Tdp / Tdp_set; Kd, Kp1, Ki1, and Kw are coefficients.

[0082] The fifth formula is:

[0083] F0=z1+a1*Qtot+b1*SHR+c1*Qtot 2 +d1*SHR 2 +e1*Qtot*SHR.

[0084] In the formula, F0 is the operating frequency of the compressor; z1, a1, b1, c1, d1, and e1 are coefficients; Qtot is the total refrigerating capacity of the air conditioner, Qtot=Qlat+Qsen; SHR is the sensible heat ratio; SHR=Qsen / Qtot; Qlat is the humidity load; and Qsen is the heat load.

[0085] When the air conditioner is in stable temperature and humidity control, the indoor heat load Qsen is equal to the sensible heat output by the air conditioner, and the indoor moisture load Qlat is equal to the latent heat output by the air conditioner, so the total refrigerating capacity Qtot of the air conditioner is equal to the sum of the sensible heat and the latent heat, i.e. Qtot = Qsen + Qlat. The calculation formula of the heat load Qsen is:

[0086] Qsen = a3 * (Tin - T_set) + b3 * Tout + c3;

[0087] The calculation formula of the moisture load Qlat is:

[0088] Qlat = a4 * (Tdp - Tdp_set) + b4 * Tout + c4;

[0089] In the formula, a3, a4, b3, b4, c3 and c4 are coefficients determined by experiments; Tin is the indoor dry-bulb temperature; Tin_set is the indoor set temperature; Tout is the outdoor environment temperature; Tdp is the indoor dew point temperature; Tdp_set is the indoor set dew point temperature, which can be calculated according to the indoor set temperature T_set and the set relative humidity RH_set through the theory of moisture air state parameters. It should be noted that the way of calculating the heat load and the moisture load is not limited to the above formula, and the heat load and the moisture load can also be calculated according to other empirical formulas, experimental fitting formulas, big data and big model fitting formulas, etc.

[0090] In some embodiments, in step S130, the specific process of determining the control strategy for controlling the rotation speed of the indoor fan according to the size of the indoor dew point temperature includes: judging the size of the absolute value of the difference between the indoor dew point temperature and the indoor set dew point temperature; if the absolute value of the difference between the indoor dew point temperature and the indoor set dew point temperature is less than a second temperature difference, the control strategy for controlling the rotation speed of the indoor fan is that the indoor fan is controlled to run according to the result of calculating the rotation speed of the indoor fan according to the second formula in the PD feedback control; if the absolute value of the difference between the indoor dew point temperature and the indoor set dew point temperature is greater than or equal to the second temperature difference, the control strategy for controlling the rotation speed of the indoor fan is that the indoor fan is controlled to run according to the result of calculating the rotation speed of the indoor fan according to the sixth formula in the heat load and moisture load control.

[0091] The indoor set dew point temperature Tdp_set can be calculated according to the indoor set temperature T_set and the set relative humidity RH_set by the wet air state parameter theory. The indoor dew point temperature Tdp can be calculated according to the indoor environment dry bulb temperature Tin, the indoor relative humidity RH and the outdoor environment temperature Tout. After the air conditioner is turned on, the rotation speed of the indoor fan is first controlled according to the first stage control, and then it is determined whether the second stage control is executed according to the size of the indoor dew point temperature Tdp. The first stage is the control according to the heat load and the wet load, and the second stage is the control according to the PD feedback. The second stage is the accurate temperature and humidity control logic. The distinguishing point of the first stage and the second stage lies in whether the indoor dew point temperature Tdp reaches the indoor set dew point temperature Tdp_set. The second temperature difference is used to judge whether the indoor dew point temperature Tdp and the indoor set dew point temperature Tdp_set are greatly different, which can be set to 1℃. When |Tdp-Tdp_set|<1℃, the indoor dew point temperature Tdp and the indoor set dew point temperature Tdp_set are not greatly different, it is considered that the indoor dew point temperature Tdp meets the threshold interval, and the condition of the PD feedback control is reached; when |Tdp-Tdp_set|≥1℃, the control of the first stage is continuously executed.

[0092] The second formula is:

[0093] C(n+1)=C(n)+Kp2*△Tdp+Ki2*δTdp.

[0094] In the formula, C(n+1), C(n) are the rotation speeds of the indoor fan, n is the cycle number; △Tdp is the difference between the indoor dew point temperature and the indoor target dew point temperature; δTdp is the deviation rate between the indoor dew point temperature and the indoor target dew point temperature; Kp2, Ki2 are coefficients.

[0095] The sixth formula is:

[0096] C0=z2+a2*Qtot+b2*SHR+c2*Qtot 2 +d2*SHR 2 +e2*Qtot*SHR.

[0097] In the formula, C0 is the rotation speed of the indoor fan; z2, a2, b2, c2, d2, e2 are all coefficients; Qtot is the total refrigerating capacity of the air conditioner, Qtot=Qlat+Qsen; SHR is the sensible heat ratio; SHR=Qsen / Qtot; Qlat is the wet load; Qsen is the heat load.

[0098] In some embodiments, in step S140, according to the size of the suction gas superheat of the first indoor heat exchanger and the size of the suction gas superheat of the second indoor heat exchanger, the specific process of determining the control strategy of the opening degree of the first branch throttling component and the opening degree of the second branch throttling component respectively includes: judging the size of the absolute value of the difference between the suction gas superheat of the first indoor heat exchanger and the first set suction gas superheat, if the absolute value of the difference between the suction gas superheat of the first indoor heat exchanger and the first set suction gas superheat is less than the preset suction gas superheat difference, the control strategy of the opening degree of the first branch throttling component is that the first branch throttling component is controlled to operate according to the result of calculating the opening degree of the first branch throttling component in the PD feedback control according to the third formula; if the absolute value of the difference between the suction gas superheat of the first indoor heat exchanger and the first set suction gas superheat is greater than or equal to the preset suction gas superheat difference, the control strategy of the opening degree of the first branch throttling component is the fitting formula control strategy. And, judging the size of the absolute value of the difference between the suction gas superheat of the second indoor heat exchanger and the second set suction gas superheat, if the absolute value of the difference between the suction gas superheat of the second indoor heat exchanger and the second set suction gas superheat is less than the preset suction gas superheat difference, the control strategy of the opening degree of the second branch throttling component is that the second branch throttling component is controlled to operate according to the result of calculating the opening degree of the second branch throttling component in the PD feedback control according to the fourth formula; if the absolute value of the difference between the suction gas superheat of the second indoor heat exchanger and the second set suction gas superheat is greater than or equal to the preset suction gas superheat difference, the control strategy of the opening degree of the second branch throttling component is the fitting formula control strategy.

[0099] The third formula is:

[0100] B1(n+1) = B1(n) + Kp3*△sh1 + Ki3*δsh1.

[0101] The fourth formula is:

[0102] B2(n+1) = B2(n) + Kp4*△sh2 + Ki4*δsh2.

[0103] In the formula, B1(n), B1(n+1) are the opening degrees of the first branch throttling component, B2(n), B2(n+1) are the opening degrees of the second branch throttling component, n is the cycle number; △sh1 is the difference between the suction gas superheat of the first indoor heat exchanger and the first set suction gas superheat, i.e. △sh1 = |sh_obj1-sh_1|; δsh1 is the deviation rate between the suction gas superheat of the first indoor heat exchanger and the first set suction gas superheat, i.e. δsh1 = △sh1 / sh_1; △sh2 is the difference between the suction gas superheat of the second indoor heat exchanger and the second set suction gas superheat, i.e.

[0104] △sh1=|sh_obj2-sh_2|; δsh2 is a deviation rate between the suction superheat of the second indoor heat exchanger and the second set suction superheat, i.e. δsh2=△sh2 / sh_2; Kp3, Ki3, Kp4 and Ki4 are all coefficients.

[0105] The fitting formula control strategy of the opening degree of the first branch throttling component and the opening degree of the second branch throttling component is the same; the fitting formula control strategy is to obtain the mass flow of the first branch throttling component and the second branch throttling component according to a seventh calculation formula, and to obtain the opening degree of the first branch throttling component and the opening degree of the second branch throttling component according to a preset corresponding relationship between the mass flow and the opening degree; the seventh calculation formula is:

[0106] Mr=f(F, ηv, tsuc_obj, tevap);

[0107] In the formula, Mr is the mass flow of the first branch throttling component and the second branch throttling component; F is the operating frequency of the compressor; ηv is the volumetric efficiency; if Mr is the mass flow of the first branch throttling component, tsuc_obj is the target suction superheat of the first indoor heat exchanger, and tevap is the evaporation temperature of the first indoor heat exchanger; if Mr is the mass flow of the second branch throttling component, tsuc_obj is the target suction superheat of the second indoor heat exchanger, and tevap is the evaporation temperature of the second indoor heat exchanger.

[0108] For the opening degree control of the first secondary electronic expansion valve and the second secondary electronic expansion valve, the air conditioner is first controlled according to the first stage control opening degree after being turned on, and then it is determined whether to perform the second stage control according to the suction superheat of the indoor heat exchanger directly connected with the secondary electronic expansion valve. The first stage is controlled according to the fitting formula, and the second stage is controlled according to the PD feedback. The second stage is the precise temperature and humidity control logic. The distinguishing point between the first stage and the second stage lies in whether the suction superheat reaches the set suction superheat. The preset suction superheat difference Δsh is used to judge whether the suction superheat and the set suction superheat differ greatly. Taking the first secondary electronic expansion valve as an example, the suction superheat of the first indoor heat exchanger is sh_obj1, and the corresponding set suction superheat is sh_1. When |sh_obj1-sh_1|<Δsh, the suction superheat and the set suction superheat differ slightly, and it is considered that the suction superheat meets the threshold interval, and the first secondary electronic expansion valve reaches the condition of performing the PD feedback control; when |sh_obj1-sh_1|≥Δsh, the first stage control is continued to be performed.

[0109] Figure 4 The flowchart of another embodiment of the control method of the air conditioner of the present application is shown in FIG. 4. Figure 4As shown, comprising:

[0110] Step 1, obtaining indoor dry bulb temperature and indoor relative humidity set value, calculating indoor dew point temperature set value. Obtain indoor dry bulb temperature, indoor relative humidity, outdoor environment temperature current value, calculate indoor dew point temperature current value. Estimate indoor heat load and wet load according to indoor dry bulb temperature and indoor dew point temperature set value and indoor dry bulb temperature, indoor dew point temperature and outdoor environment temperature current value. Determine the initial operation parameters of the air conditioner based on the indoor heat load and the wet load.

[0111] Step 2, according to the indoor dry bulb temperature and the indoor dew point temperature set value and the current value, the PD control feedback adjustment air conditioner operation parameter is adjusted to stable temperature and humidity control.

[0112] Step 3, the opening degree of the first throttling electronic expansion valve is controlled by the intermediate target temperature, and the intermediate target temperature is calculated by an empirical formula. The empirical formula needs to obtain the characteristic parameters of the high-pressure path and the low-pressure path of the system; the opening degree of the second throttling electronic expansion valve includes a calculated value and a feedback control. The calculated value of the empirical formula needs to obtain the characteristic parameters of the compressor, the pre-stored characteristic parameters of the electronic expansion valve and the state parameters of the system, and the feedback control is realized by the pre-set suction target superheat degree.

[0113] The technical scheme of the embodiment is adopted, the air conditioner has the first indoor heat exchanger and the second indoor heat exchanger in parallel, the first indoor heat exchanger and the throttling component of the air conditioner are provided with the first branch throttling component, and the second indoor heat exchanger and the throttling component of the air conditioner are provided with the second branch throttling component; after the air conditioner starts to operate, the control strategy for determining the operating frequency of the compressor according to the indoor dry bulb temperature is a PD feedback control strategy or a heat load and wet load control strategy, the control strategy for determining the rotating speed of the indoor fan according to the indoor dew point temperature is a PD feedback control strategy or a heat load and wet load control strategy, and the control strategy for determining the opening degree of the first branch throttling component and the opening degree of the second branch throttling component according to the suction superheat degrees of the first indoor heat exchanger and the second indoor heat exchanger is a PD feedback control strategy or a fitting formula control strategy. Therefore, by combining the PD feedback control and the heat and wet load control, the operating states of the compressor, the indoor fan and the throttling component in the parallel air conditioning system are controlled, so that the system can be accurately controlled in temperature and humidity and stably and efficiently operated.

[0114] According to the embodiment of the application, a control device of an air conditioner corresponding to a control method of the air conditioner is also provided. The air conditioner has a first indoor heat exchanger and a second indoor heat exchanger arranged in parallel; a first branch throttling component is arranged between the first indoor heat exchanger and a throttling component of the air conditioner, and a second branch throttling component is arranged between the second indoor heat exchanger and the throttling component of the air conditioner; an indoor fan is arranged at the first indoor heat exchanger and the second indoor heat exchanger.

[0115] The system structure of the air conditioner is as followsFigure 3 As shown, the throttling component of the air conditioner is a first electronic expansion valve 31, the first branch throttling component is a first second electronic expansion valve 32, and the second branch throttling component is a second second electronic expansion valve 33. Specifically, the pipeline at the exhaust port 14 of the compressor 10 of the air conditioner sequentially passes through the outdoor heat exchanger 20, the first electronic expansion valve 31, and is connected to the flash tank 40. The flash tank 40 has two refrigerant outlets, one of which is connected to the third suction port 13 of the compressor, and the other of which is provided with a first branch and a second branch in parallel between the flash tank 40 and the compressor. On the first branch, along the direction from the flash tank 40 to the compressor 10, the first second electronic expansion valve 32 and the first indoor heat exchanger 51 are sequentially arranged, and finally connected to the first suction port 11 of the compressor. On the second branch, along the direction from the flash tank 40 to the compressor 10, the second second electronic expansion valve 33 and the second indoor heat exchanger 52 are sequentially arranged, and finally connected to the second suction port 12 of the compressor.

[0116] The first indoor heat exchanger and the second indoor heat exchanger are arranged side by side in the same air duct and have an upstream and downstream relationship. Figure 3 In particular, the first indoor heat exchanger 51 is at an upstream position, and the second indoor heat exchanger 52 is at a downstream position.

[0117] Referring to Figure 2 As shown in the structural schematic diagram of an embodiment of the device of the application. The control device of the air conditioner can include an acquisition unit 102 and a control unit 104.

[0118] The acquisition unit 102 is configured to acquire the indoor dry-bulb temperature, the indoor dew-point temperature, the suction superheat of the first indoor heat exchanger, and the suction superheat of the second indoor heat exchanger after the air conditioner starts running. The specific functions and processes of the acquisition unit 102 are described with reference to step S110.

[0119] The control unit 104 is configured to determine a control strategy for controlling the operating frequency of the compressor of the air conditioner according to the size of the indoor dry-bulb temperature, to control the operation of the compressor. The specific functions and processes of the control unit 104 are described with reference to step S120.

[0120] The control unit 104 is further configured to determine a control strategy for controlling the rotating speed of the indoor fan according to the size of the indoor dew-point temperature, to control the operation of the indoor fan. The specific functions and processes of the control unit 104 are described with reference to step S130.

[0121] The control unit 104 is also configured to determine a control strategy for controlling the opening degree of the first branch throttling component and the opening degree of the second branch throttling component according to the size of the suction superheat degree of the first indoor heat exchanger and the suction superheat degree of the second indoor heat exchanger, respectively, to control the operation of the first branch throttling component and the second branch throttling component. The specific functions and processes of the control unit 104 are described in step S140.

[0122] The control strategy for controlling the operating frequency of the compressor of the air conditioner includes a PD feedback control strategy, a heat load and a humidity load control strategy; the control strategy for controlling the rotating speed of the indoor fan includes a PD feedback control strategy, a heat load and a humidity load control strategy; the control strategy for controlling the opening degree of the first branch throttling component and the opening degree of the second branch throttling component includes a PD feedback control strategy, a fitting formula control strategy.

[0123] The operation of the air conditioner is divided into a first stage and a second stage. In the first stage, the air conditioner obtains the operating parameters of the air conditioner according to the preset calculation formula according to the collected temperature, humidity and suction superheat degree, and controls the operating frequency of the compressor, the rotating speed of the indoor fan and the opening degree of the throttling component. In the second stage, the operating parameters are calculated according to the PD feedback control, so as to realize the coupling processing of the two indoor heat exchangers for sensible heat load and latent heat load, so as to achieve the purpose of precise temperature and humidity control and high-efficiency operation of the air conditioning system. The judgment conditions for selecting the first stage or the second stage for the compressor, the indoor fan and the throttling component are different.

[0124] The first-stage electronic expansion valve and the second-stage electronic expansion valve are in linkage control. Specifically, the refrigerant mass flow rate of the first-stage electronic expansion valve is calculated according to the refrigerant mass flow rates of the first and second-stage electronic expansion valves, and the opening degree value of the first-stage electronic expansion valve is converted according to the relationship between the mass flow rate and the opening degree, and the first-stage electronic expansion valve is controlled according to the opening degree value. The calculation formula is:

[0125] Mr_m=(Mr1+Mr2) / (1-x_ft)。

[0126] In the formula, Mr_m is the mass flow rate of the first-stage electronic expansion valve; Mr1 is the mass flow rate of the first and second-stage electronic expansion valves; Mr2 is the mass flow rate of the second-stage electronic expansion valve; x_ft is the first-stage throttling flash dryness, and the calculation formula is as follows:

[0127] x_ft=i*(t_c_o-t_ft_target) / (j-k*t_ft_target)。

[0128] In the formula, i, j and k are pre-stored coefficients determined by experiments; t_c_o is the outlet temperature of the condenser, and t_ft_target is the intermediate temperature target value of the opening degree of the first-stage electronic expansion valve, and the calculation formula is as follows:

[0129] t ft target = m * tc o + n * (tevap1 + tevap2).

[0130] In the formula, m and n are pre-stored coefficients determined by experiments; tc o is the condenser outlet temperature; tevap1 is the evaporation temperature of the first indoor heat exchanger; and tevap2 is the evaporation temperature of the second indoor heat exchanger. The high-pressure path parameters include the condenser outlet temperature tc o, and the low-pressure path parameters include the evaporation temperatures tevap1 and tevap2 of the first and second indoor heat exchangers.

[0131] By determining the intermediate temperature target value of the opening degree of the primary electronic expansion valve according to the evaporation temperatures of all the indoor heat exchangers in the parallel air conditioning system, and combining the mass flow rates of all the secondary electronic expansion valves, the opening degree of the primary electronic expansion valve is obtained, so as to improve the temperature and humidity control effect of the parallel air conditioning system and improve the energy efficiency performance of the system.

[0132] In some embodiments, the PD feedback control strategy includes: controlling the operation of the compressor according to the result of calculating the operating frequency of the compressor according to the first formula, controlling the operation of the inner fan according to the result of calculating the rotating speed of the inner fan according to the second formula, controlling the operation of the first branch throttling component according to the result of calculating the opening degree of the first branch throttling component according to the third formula, and controlling the operation of the second branch throttling component according to the result of calculating the opening degree of the second branch throttling component according to the fourth formula; and the thermal and humidity load control strategy includes: controlling the operation of the compressor according to the result of calculating the operating frequency of the compressor according to the fifth formula, and controlling the operation of the inner fan according to the result of calculating the rotating speed of the inner fan according to the sixth formula.

[0133] In some embodiments, the control unit 104 determines the specific process of controlling the operating frequency control strategy of the compressor of the air conditioner according to the size of the indoor dry-bulb temperature, which includes: judging the size of the absolute value of the difference between the indoor dry-bulb temperature and the indoor set temperature; if the absolute value of the difference between the indoor dry-bulb temperature and the indoor set temperature is less than a first temperature difference, the operating frequency control strategy of the compressor of the air conditioner is controlled to be the result of controlling the operation of the compressor according to the calculation of the operating frequency of the compressor according to the first formula in the PD feedback control; and if the absolute value of the difference between the indoor dry-bulb temperature and the indoor set temperature is greater than or equal to the first temperature difference, the operating frequency control strategy of the compressor of the air conditioner is controlled to be the result of controlling the operation of the compressor according to the calculation of the operating frequency of the compressor according to the fifth formula in the thermal and humidity load control.

[0134] For the control of the compressor operating frequency, the air conditioner is first controlled according to the first stage after being turned on, and then whether the second stage control is executed is determined according to the size of the indoor dry-bulb temperature Tin. The first stage is controlled according to the heat load and the humidity load, and the second stage is controlled according to the PD feedback. The second stage is the precise temperature and humidity control logic. The dividing point between the first stage and the second stage is whether the indoor dry-bulb temperature Tin reaches the indoor set temperature T_set. The indoor set temperature T_set is set by the user. The first temperature difference value is used to judge whether the indoor dry-bulb temperature Tin and the indoor set temperature T_set are greatly different, which can be set to 1.5℃. When |Tin-T_set|<1.5℃, the indoor dry-bulb temperature Tin and the indoor set temperature T_set are not greatly different, and it is considered that the indoor dry-bulb temperature Tin meets the threshold interval and reaches the condition of PD feedback control; when |Tin-T_set|≥1.5℃, the first stage control is continued to be executed.

[0135] The first formula is:

[0136] F(n+1)=F(n)+Kd*(Kp1*△Tdr+Ki1*δTdr)+Kw*(Kp2*△Tdp+Ki1*δTdp).

[0137] In the formula, F(n+1) and F(n) are the operating frequency of the compressor, and n is the cycle number; △Tdr is the difference between the indoor dry-bulb temperature and the indoor set temperature, that is, △Tdr=|Tin-T_set|; δTdr is the deviation rate between the indoor dry-bulb temperature and the indoor set temperature, that is, δTdr=△Tdr / T_set; △Tdp is the difference between the indoor dew-point temperature and the indoor target dew-point temperature, that is, △Tdp=|Tdp-Tdp_set|; δTdp is the deviation rate between the indoor dew-point temperature and the indoor target dew-point temperature, that is, δTdp=△Tdp / Tdp_set; Kd, Kp1, Ki1, and Kw are coefficients.

[0138] The fifth formula is:

[0139] F0=z1+a1*Qtot+b1*SHR+c1*Qtot 2 +d1*SHR 2 +e1*Qtot*SHR.

[0140] In the formula, F0 is the operating frequency of the compressor; z1, a1, b1, c1, d1, and e1 are coefficients; Qtot is the total refrigerating capacity of the air conditioner, Qtot=Qlat+Qsen; SHR is the sensible heat ratio, SHR=Qsen / Qtot; Qlat is the humidity load; and Qsen is the heat load.

[0141] When the air conditioner is in stable temperature and humidity control, the indoor heat load Qsen is equal to the sensible heat output by the air conditioner, and the indoor moisture load Qlat is equal to the latent heat output by the air conditioner, so that the total refrigerating capacity Qtot of the air conditioner is equal to the sum of the sensible heat and the latent heat, i.e., Qtot = Qsen + Qlat. The calculation formula of the heat load Qsen is:

[0142] Qsen = a3 * (Tin - T_set) + b3 * Tout + c3;

[0143] The calculation formula of the moisture load Qlat is:

[0144] Qlat = a4 * (Tdp - Tdp_set) + b4 * Tout + c4;

[0145] In the formula, a3, a4, b3, b4, c3, and c4 are coefficients determined by experiments; Tin is the indoor dry-bulb temperature; Tin_set is the indoor set temperature; Tout is the outdoor environment temperature; Tdp is the indoor dew-point temperature; and Tdp_set is the indoor set dew-point temperature, which can be calculated according to the indoor set temperature T_set and the set relative humidity RH_set through the theory of moisture air state parameters. It should be noted that the way of calculating the heat load and the moisture load is not limited to the above formula, and the heat load and the moisture load can also be calculated according to other empirical formulas, experimental fitting formulas, big data and big model fitting formulas, etc.

[0146] In some embodiments, the control unit 104 determines the specific process of the control strategy for controlling the rotation speed of the indoor fan according to the size of the indoor dew-point temperature, which includes: judging the size of the absolute value of the difference between the indoor dew-point temperature and the indoor set dew-point temperature; if the absolute value of the difference between the indoor dew-point temperature and the indoor set dew-point temperature is less than a second temperature difference, the control strategy for controlling the rotation speed of the indoor fan is that the indoor fan is controlled to operate according to the result of calculating the rotation speed of the indoor fan in the PD feedback control according to the second formula; and if the absolute value of the difference between the indoor dew-point temperature and the indoor set dew-point temperature is greater than or equal to the second temperature difference, the control strategy for controlling the rotation speed of the indoor fan is that the indoor fan is controlled to operate according to the result of calculating the rotation speed of the indoor fan in the heat load and moisture load control according to the sixth formula.

[0147] The indoor set dew point temperature Tdp_set can be calculated according to the indoor set temperature T_set and the set relative humidity RH_set by the wet air state parameter theory. The indoor dew point temperature Tdp can be calculated according to the indoor environment dry bulb temperature Tin, the indoor relative humidity RH and the outdoor environment temperature Tout. After the air conditioner is turned on, the rotation speed of the indoor fan is first controlled according to the first stage control, and then it is determined whether the second stage control is executed according to the size of the indoor dew point temperature Tdp. The first stage is the control according to the heat load and the wet load, and the second stage is the control according to the PD feedback. The second stage is the accurate temperature and humidity control logic. The distinguishing point of the first stage and the second stage lies in whether the indoor dew point temperature Tdp reaches the indoor set dew point temperature Tdp_set. The second temperature difference is used to judge whether the indoor dew point temperature Tdp and the indoor set dew point temperature Tdp_set are greatly different, which can be set to 1℃. When |Tdp-Tdp_set|<1℃, the indoor dew point temperature Tdp and the indoor set dew point temperature Tdp_set are not greatly different, it is considered that the indoor dew point temperature Tdp meets the threshold interval, and the condition of the PD feedback control is reached; when |Tdp-Tdp_set|≥1℃, the control of the first stage is continuously executed.

[0148] The second formula is:

[0149] C(n+1)=C(n)+Kp2*△Tdp+Ki2*δTdp.

[0150] In the formula, C(n+1) and C(n) are the rotation speeds of the indoor fan, and n is the cycle number; △Tdp is the difference between the indoor dew point temperature and the indoor target dew point temperature; δTdp is the deviation rate between the indoor dew point temperature and the indoor target dew point temperature; Kp2 and Ki2 are coefficients.

[0151] The sixth formula is:

[0152] C0=z2+a2*Qtot+b2*SHR+c2*Qtot 2 +d2*SHR 2 +e2*Qtot*SHR.

[0153] In the formula, C0 is the rotation speed of the indoor fan; z2, a2, b2, c2, d2 and e2 are coefficients; Qtot is the total refrigerating capacity of the air conditioner, Qtot=Qlat+Qsen; SHR is the sensible heat ratio, SHR=Qsen / Qtot; Qlat is the wet load; and Qsen is the heat load.

[0154] In some embodiments, the control unit 104 determines the specific process of the control strategy for controlling the opening degree of the first branch throttling component and the opening degree of the second branch throttling component according to the size of the suction superheat degree of the first indoor heat exchanger and the size of the suction superheat degree of the second indoor heat exchanger, which includes: judging the size of the absolute value of the difference between the suction superheat degree of the first indoor heat exchanger and the first set suction superheat degree, if the absolute value of the difference between the suction superheat degree of the first indoor heat exchanger and the first set suction superheat degree is less than the preset suction superheat degree difference, the control strategy for controlling the opening degree of the first branch throttling component is the result of calculating the opening degree of the first branch throttling component according to the third formula in the PD feedback control to control the operation of the first branch throttling component; if the absolute value of the difference between the suction superheat degree of the first indoor heat exchanger and the first set suction superheat degree is greater than or equal to the preset suction superheat degree difference, the control strategy for controlling the opening degree of the first branch throttling component is the fitting formula control strategy. And, judging the size of the absolute value of the difference between the suction superheat degree of the second indoor heat exchanger and the second set suction superheat degree, if the absolute value of the difference between the suction superheat degree of the second indoor heat exchanger and the second set suction superheat degree is less than the preset suction superheat degree difference, the control strategy for controlling the opening degree of the second branch throttling component is the result of calculating the opening degree of the second branch throttling component according to the fourth formula in the PD feedback control to control the operation of the second branch throttling component; if the absolute value of the difference between the suction superheat degree of the second indoor heat exchanger and the second set suction superheat degree is greater than or equal to the preset suction superheat degree difference, the control strategy for controlling the opening degree of the second branch throttling component is the fitting formula control strategy.

[0155] The third formula is:

[0156] B1(n+1) = B1(n) + Kp3*△sh1 + Ki3*δsh1.

[0157] The fourth formula is:

[0158] B2(n+1) = B2(n) + Kp4*△sh2 + Ki4*δsh2.

[0159] In the formula, B1(n), B1(n+1) are the opening degrees of the first branch throttling component, B2(n), B2(n+1) are the opening degrees of the second branch throttling component, n is the cycle number; △sh1 is the difference between the suction superheat degree of the first indoor heat exchanger and the first set suction superheat degree, that is, △sh1 = |sh_obj1-sh_1|; δsh1 is the deviation rate between the suction superheat degree of the first indoor heat exchanger and the first set suction superheat degree, that is, δsh1 = △sh1 / sh_1; △sh2 is the difference between the suction superheat degree of the second indoor heat exchanger and the second set suction superheat degree, that is,

[0160] △sh1=|sh_obj2-sh_2|; δsh2 is a deviation rate between suction superheat of the second indoor heat exchanger and the second set suction superheat, i.e. δsh2=△sh2 / sh_2; Kp3, Ki3, Kp4 and Ki4 are all coefficients.

[0161] The fitting formula control strategy of the opening degree of the first branch throttling component and the opening degree of the second branch throttling component is the same; the fitting formula control strategy is to obtain the mass flow of the first branch throttling component and the second branch throttling component according to a seventh calculation formula, and to obtain the opening degree of the first branch throttling component and the opening degree of the second branch throttling component according to a preset corresponding relationship between the mass flow and the opening degree; the seventh calculation formula is:

[0162] Mr=f(F, ηv, tsuc_obj, tevap);

[0163] In the formula, Mr is the mass flow of the first branch throttling component and the second branch throttling component; F is the operating frequency of the compressor; ηv is the volumetric efficiency; if Mr is the mass flow of the first branch throttling component, tsuc_obj is the target suction superheat of the first indoor heat exchanger, and tevap is the evaporation temperature of the first indoor heat exchanger; if Mr is the mass flow of the second branch throttling component, tsuc_obj is the target suction superheat of the second indoor heat exchanger, and tevap is the evaporation temperature of the second indoor heat exchanger.

[0164] For the opening degree control of the first secondary electronic expansion valve and the second secondary electronic expansion valve, the air conditioner is first controlled according to the first stage control opening degree after being turned on, and then it is determined whether to perform the second stage control according to the suction superheat of the indoor heat exchanger directly connected with the secondary electronic expansion valve. The first stage is controlled according to the fitting formula, and the second stage is controlled according to the PD feedback. The second stage is the precise temperature and humidity control logic. The distinguishing point between the first stage and the second stage lies in whether the suction superheat reaches the set suction superheat. The preset suction superheat difference Δsh is used to judge whether the suction superheat and the set suction superheat differ greatly. Taking the first secondary electronic expansion valve as an example, the suction superheat of the first indoor heat exchanger is sh_obj1, and the corresponding set suction superheat is sh_1. When |sh_obj1-sh_1|<Δsh, the suction superheat and the set suction superheat differ slightly, and it is considered that the suction superheat meets the threshold interval, and the first secondary electronic expansion valve reaches the condition of performing the PD feedback control; when |sh_obj1-sh_1|≥Δsh, the first stage control is continued to be performed.

[0165] Figure 4 The flowchart of another embodiment of the control method of the air conditioner of the present application is shown in FIG. 6. Figure 4As shown, comprising:

[0166] Step 1, obtaining indoor dry bulb temperature and indoor relative humidity set value, calculating indoor dew point temperature set value. Obtaining indoor dry bulb temperature, indoor relative humidity, outdoor environment temperature current value, calculating indoor dew point temperature current value. Estimating indoor heat load and wet load according to indoor dry bulb temperature and indoor dew point temperature set value and indoor dry bulb temperature, indoor dew point temperature and outdoor environment temperature current value. Determining air conditioner initial operation parameter based on indoor heat load and wet load.

[0167] Step 2, according to indoor dry bulb temperature and indoor dew point temperature set value and current value, PD control feedback adjustment air conditioner operation parameter to stable temperature and humidity control.

[0168] Step 3, the first throttling electronic expansion valve opening degree is controlled by the intermediate target temperature, the intermediate target temperature is calculated by the empirical formula, the empirical formula needs to obtain the system high pressure path characteristic parameter and the low pressure path characteristic parameter; the second throttling electronic expansion valve opening degree includes two parts of calculation value and feedback control. The calculation value empirical formula needs to obtain the compressor characteristic parameter, the pre-stored electronic expansion valve characteristic parameter and the system state parameter, and the feedback control is realized by the preset suction target superheat degree.

[0169] Since the processing and functions realized by the device of the embodiment are basically corresponding to the embodiments, principles and examples of the foregoing method, the description of the embodiment will not be described in detail, and the related description in the foregoing embodiments can be referred to, which will not be described herein.

[0170] By adopting the technical scheme of the present application, the air conditioner has the first indoor heat exchanger and the second indoor heat exchanger in parallel, the first indoor heat exchanger and the throttling component of the air conditioner are provided with the first branch throttling component, the second indoor heat exchanger and the throttling component of the air conditioner are provided with the second branch throttling component; after the air conditioner starts to operate, the control strategy for determining the operating frequency of the compressor according to the indoor dry bulb temperature is the PD feedback control strategy or the heat load and wet load control strategy, the control strategy for determining the rotating speed of the indoor fan according to the indoor dew point temperature is the PD feedback control strategy or the heat load and wet load control strategy, and the control strategy for determining the opening degree of the first branch throttling component and the opening degree of the second branch throttling component according to the suction superheat degrees of the first indoor heat exchanger and the second indoor heat exchanger is the PD feedback control strategy or the fitting formula control strategy. Therefore, by combining the PD feedback control and the heat and wet load control, the operating states of the compressor, the indoor fan and the throttling component in the parallel air conditioning system are controlled, so that the system can be accurately controlled in temperature and humidity and stably and efficiently operated.

[0171] According to the embodiment of the present application, an air conditioner corresponding to the control device of the air conditioner is also provided. The air conditioner can include the control device of the air conditioner described above.

[0172] Since the processing and functions realized by the air conditioner of the embodiment basically correspond to the foregoing embodiments, principles and examples of the device, the description of the embodiment will not be elaborated on the related descriptions in the foregoing embodiments, and will not be repeated here.

[0173] According to the technical solution of the present application, the air conditioner has the first indoor heat exchanger and the second indoor heat exchanger in parallel, the first branch throttling component is arranged between the first indoor heat exchanger and the throttling component of the air conditioner, and the second branch throttling component is arranged between the second indoor heat exchanger and the throttling component of the air conditioner; after the air conditioner starts to operate, the control strategy for determining the operating frequency of the compressor according to the indoor dry-bulb temperature is a PD feedback control strategy or a heat load and humidity load control strategy, the control strategy for determining the rotating speed of the indoor fan according to the indoor dew-point temperature is a PD feedback control strategy or a heat load and humidity load control strategy, and the control strategy for determining the opening degree of the first branch throttling component and the opening degree of the second branch throttling component according to the suction superheat of the first indoor heat exchanger and the suction superheat of the second indoor heat exchanger is a PD feedback control strategy or a fitting formula control strategy. Thus, by combining the PD feedback control and the heat and humidity load control, the operating states of the compressor, the indoor fan and the throttling component in the parallel air conditioner system are controlled, so that the system can be accurately controlled in temperature and humidity and stably and efficiently operated.

[0174] According to the embodiment of the present application, a storage medium corresponding to the control method of the air conditioner is also provided, the storage medium includes a stored program, wherein when the program is executed, the device where the storage medium is located performs the control method of the air conditioner.

[0175] Since the processing and functions realized by the storage medium of the embodiment basically correspond to the foregoing embodiments, principles and examples of the method, the description of the embodiment will not be elaborated on the related descriptions in the foregoing embodiments, and will not be repeated here.

[0176] According to the technical solution of the present application, the air conditioner has the first indoor heat exchanger and the second indoor heat exchanger in parallel, the first branch throttling component is arranged between the first indoor heat exchanger and the throttling component of the air conditioner, and the second branch throttling component is arranged between the second indoor heat exchanger and the throttling component of the air conditioner; after the air conditioner starts to operate, the control strategy for determining the operating frequency of the compressor according to the indoor dry-bulb temperature is a PD feedback control strategy or a heat load and humidity load control strategy, the control strategy for determining the rotating speed of the indoor fan according to the indoor dew-point temperature is a PD feedback control strategy or a heat load and humidity load control strategy, and the control strategy for determining the opening degree of the first branch throttling component and the opening degree of the second branch throttling component according to the suction superheat of the first indoor heat exchanger and the suction superheat of the second indoor heat exchanger is a PD feedback control strategy or a fitting formula control strategy. Thus, by combining the PD feedback control and the heat and humidity load control, the operating states of the compressor, the indoor fan and the throttling component in the parallel air conditioner system are controlled, so that the system can be accurately controlled in temperature and humidity and stably and efficiently operated.

[0177] According to the embodiment of the present application, a computer program product corresponding to the control method of the air conditioner is also provided, which comprises a computer program, and the computer program product is processed to implement the steps of the control method of the air conditioner.

[0178] Since the processing and functions implemented by the computer program product of the present embodiment are basically corresponding to the embodiments, principles and examples of the foregoing method, the description of the present embodiment will not be elaborated on the related description in the foregoing embodiments, and will not be repeated here.

[0179] With the technical solution of the present application, the air conditioner has the first indoor heat exchanger and the second indoor heat exchanger in parallel, the first branch throttling component is arranged between the first indoor heat exchanger and the throttling component of the air conditioner, and the second branch throttling component is arranged between the second indoor heat exchanger and the throttling component of the air conditioner; after the air conditioner starts to operate, the control strategy for determining the operating frequency of the compressor according to the indoor dry-bulb temperature is the PD feedback control strategy or the heat load and humidity load control strategy, the control strategy for determining the rotating speed of the indoor fan according to the indoor dew-point temperature is the PD feedback control strategy or the heat load and humidity load control strategy, and the control strategy for determining the opening degree of the first branch throttling component and the opening degree of the second branch throttling component according to the suction superheat of the first indoor heat exchanger and the suction superheat of the second indoor heat exchanger is the PD feedback control strategy or the fitting formula control strategy. Thus, by combining the PD feedback control and the heat and humidity load control, the operating states of the compressor, the indoor fan and the throttling component in the parallel air conditioning system are controlled, so that the system can be accurately controlled in temperature and humidity and stably and efficiently operated.

[0180] In summary, those skilled in the art can easily understand that the above-mentioned advantageous modes can be freely combined and superimposed without conflict.

[0181] The above only describes the embodiments of the present application and is not used to limit the present application. Those skilled in the art can make various modifications and changes to the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the scope of the claims of the present application.

Claims

1. A control method of an air conditioner, characterized by, The air conditioner has a first indoor heat exchanger and a second indoor heat exchanger arranged in parallel; a first branch throttling component is arranged between the first indoor heat exchanger and a throttling component of the air conditioner, and a second branch throttling component is arranged between the second indoor heat exchanger and the throttling component of the air conditioner; an indoor fan is arranged at the first indoor heat exchanger and the second indoor heat exchanger; The control method of the air conditioner comprises: After the air conditioner starts to operate, an indoor dry-bulb temperature, an indoor dew-point temperature, a suction superheat of the first indoor heat exchanger, and a suction superheat of the second indoor heat exchanger are obtained; A control strategy for controlling the operating frequency of the compressor of the air conditioner is determined according to the size of the indoor dry-bulb temperature, so as to control the operation of the compressor; A control strategy for controlling the rotating speed of the indoor fan is determined according to the size of the indoor dew-point temperature, so as to control the operation of the indoor fan; Control strategies for controlling the opening of the first branch throttling component and the opening of the second branch throttling component are respectively determined according to the sizes of the suction superheat of the first indoor heat exchanger and the suction superheat of the second indoor heat exchanger, so as to control the operations of the first branch throttling component and the second branch throttling component; The control strategy for controlling the operating frequency of the compressor of the air conditioner comprises a PD feedback control strategy and a thermal load and humidity load control strategy; the control strategy for controlling the rotating speed of the indoor fan comprises a PD feedback control strategy and a thermal load and humidity load control strategy; and the control strategies for controlling the opening of the first branch throttling component and the opening of the second branch throttling component comprise a PD feedback control strategy and a fitting formula control strategy. The PD feedback control strategy comprises: controlling the operation of the compressor according to the result of calculating the operating frequency of the compressor by using a first formula, controlling the operation of the indoor fan according to the result of calculating the rotating speed of the indoor fan by using a second formula, controlling the operation of the first branch throttling component according to the result of calculating the opening of the first branch throttling component by using a third formula, and controlling the operation of the second branch throttling component according to the result of calculating the opening of the second branch throttling component by using a fourth formula; The thermal load and humidity load control strategy comprises: controlling the operation of the compressor according to the result of calculating the operating frequency of the compressor by using a fifth formula, and controlling the operation of the indoor fan according to the result of calculating the rotating speed of the indoor fan by using a sixth formula; The control strategy for controlling the operating frequency of the compressor of the air conditioner according to the size of the indoor dry-bulb temperature comprises: The absolute value of the difference between the indoor dry-bulb temperature and an indoor set temperature is determined; If the absolute value of the difference between the indoor dry-bulb temperature and the indoor set temperature is less than a first temperature difference, the control strategy for controlling the operating frequency of the compressor of the air conditioner is that the compressor is controlled to operate according to the result of calculating the operating frequency of the compressor by using the first formula in the PD feedback control. If the absolute value of the difference between the indoor dry-bulb temperature and the indoor set temperature is greater than or equal to a first temperature difference value, the control strategy for controlling the operating frequency of the compressor of the air conditioner is controlled according to the result of calculating the operating frequency of the compressor in the heat load and humidity load control according to a fifth formula; and / or, The control strategy for controlling the rotating speed of the indoor fan is determined according to the size of the indoor dew-point temperature, including: judging the size of the absolute value of the difference between the indoor dew-point temperature and the indoor set dew-point temperature; If the absolute value of the difference between the indoor dew-point temperature and the indoor set dew-point temperature is less than a second temperature difference value, the control strategy for controlling the rotating speed of the indoor fan is controlled according to the result of calculating the rotating speed of the indoor fan in the PD feedback control according to a second formula to control the indoor fan to operate; If the absolute value of the difference between the indoor dew-point temperature and the indoor set dew-point temperature is greater than or equal to the second temperature difference value, the control strategy for controlling the rotating speed of the indoor fan is controlled according to the result of calculating the rotating speed of the indoor fan in the heat load and humidity load control according to a sixth formula to control the indoor fan to operate.

2. The control method of the air conditioner according to claim 1, characterized by, The control strategy for controlling the opening degree of the first branch throttling component and the opening degree of the second branch throttling component is determined according to the size of the suction superheat of the first indoor heat exchanger and the suction superheat of the second indoor heat exchanger, respectively, including: judging the size of the absolute value of the difference between the suction superheat of the first indoor heat exchanger and a first set suction superheat, If the absolute value of the difference between the suction superheat of the first indoor heat exchanger and the first set suction superheat is less than a preset suction superheat difference value, the control strategy for controlling the opening degree of the first branch throttling component is controlled according to the result of calculating the opening degree of the first branch throttling component in the PD feedback control according to a third formula to control the first branch throttling component to operate; If the absolute value of the difference between the suction superheat of the first indoor heat exchanger and the first set suction superheat is greater than or equal to the preset suction superheat difference value, the control strategy for controlling the opening degree of the first branch throttling component is the fitting formula control strategy; and / or, judging the size of the absolute value of the difference between the suction superheat of the second indoor heat exchanger and a second set suction superheat; If the absolute value of the difference between the suction superheat of the second indoor heat exchanger and the second set suction superheat is less than a preset suction superheat difference value, the control strategy for controlling the opening degree of the second branch throttling component is controlled according to the result of calculating the opening degree of the second branch throttling component in the PD feedback control according to a fourth formula to control the second branch throttling component to operate; If the absolute value of the difference between the suction superheat of the second indoor heat exchanger and the second set suction superheat is greater than or equal to the preset suction superheat difference value, the control strategy for controlling the opening degree of the second branch throttling component is the fitting formula control strategy; Wherein, the fitting formula control strategy of the opening degree of the first branch throttling component and the opening degree of the second branch throttling component is the same; the fitting formula control strategy is that the mass flow of the first branch throttling component and the second branch throttling component is obtained according to the seventh calculation formula, and the opening degree of the first branch throttling component and the opening degree of the second branch throttling component are obtained according to the corresponding relationship between the preset mass flow and the opening degree; the seventh calculation formula is: Mr=f(F,ηv,tsuc_obj,tevap); In the formula, Mr is the mass flow of the first branch throttling component and the second branch throttling component; F is the operating frequency of the compressor; ηv is the volumetric efficiency; if Mr is the mass flow of the first branch throttling component, tsuc_obj is the target suction superheat of the first indoor heat exchanger, and tevap is the evaporation temperature of the first indoor heat exchanger; if Mr is the mass flow of the second branch throttling component, tsuc_obj is the target suction superheat of the second indoor heat exchanger, and tevap is the evaporation temperature of the second indoor heat exchanger.

3. The control method of the air conditioner according to claim 1, characterized by, The first formula is: F(n+1)=F(n)+Kd*(Kp1*△Tdr+Ki1*δTdr)+Kw*(Kp2*△Tdp+Ki1*△Tdp); The second formula is: C(n+1)=C(n)+Kp2*△Tdp+Ki2*△Tdp; In the formula, F(n+1) and F(n) are the operating frequency of the compressor, C(n+1) and C(n) are the speed of the indoor fan, n is the cycle number; △Tdr is the difference between the indoor dry-bulb temperature and the indoor set temperature; δTdr is the deviation rate between the indoor dry-bulb temperature and the indoor set temperature; △Tdp is the difference between the indoor dew point temperature and the indoor target dew point temperature; δTdp is the deviation rate between the indoor dew point temperature and the indoor target dew point temperature; Kd, Kp1, Kp2, Ki1, Ki2, and Kw are all coefficients.

4. The control method of the air conditioner according to claim 1 or 2, characterized by, The third formula is: B1(n+1)=B1(n)+Kp3*△sh1+Ki3*△sh1; The fourth formula is: B2(n+1)=B2(n)+Kp4*△sh2+Ki4*△sh2; In the formula, B1(n) and B1(n+1) are the opening degree of the first branch throttling component, B2(n) and B2(n+1) are the opening degree of the second branch throttling component, and n is the cycle number; △sh1 is the difference between the suction superheat of the first indoor heat exchanger and the first set suction superheat; δsh1 is the deviation rate between the suction superheat of the first indoor heat exchanger and the first set suction superheat; △sh2 is the difference between the suction superheat of the second indoor heat exchanger and the second set suction superheat; δsh2 is the deviation rate between the suction superheat of the second indoor heat exchanger and the second set suction superheat; Kp3, Ki3, Kp4, and Ki4 are all coefficients.

5. The control method of the air conditioner according to claim 1, characterized by, The fifth formula is: F0 = z1 + a1 * Qtot + b1 * SHR + c1 * Qtot 2 + d1 * SHR 2 + e1 * Qtot * SHR; The sixth formula is: C0 = z2 + a2 * Qtot + b2 * SHR + c2 * Qtot * SHR + d2 * SHR * SHR + e2 * Qtot * SHR * SHR 2 + f2 * SHR * SHR * SHR 2 + g2 * Qtot * SHR * SHR * SHR + h2 * Qtot * Qtot * SHR * SHR * SHR + i2 * Qt In the formula, F0 is the operating frequency of the compressor; C0 is the rotating speed of the inner fan; z1, a1, b1, c1, d1, e1, z2, a2, b2, c2, d2, and e2 are coefficients; Qtot is the total refrigerating capacity of the air conditioner, Qtot=Qlat+Qsen; SHR is the sensible heat ratio, SHR=Qsen / Qtot; Qlat is the wet load; and Qsen is the heat load.

6. A control device of an air conditioner, characterized by comprising: The air conditioner has first and second indoor heat exchangers arranged in parallel; a first branch throttling component is arranged between the first indoor heat exchanger and a throttling component of the air conditioner, and a second branch throttling component is arranged between the second indoor heat exchanger and the throttling component of the air conditioner; and an inner fan is arranged at the first and second indoor heat exchangers; The control device of the air conditioner comprises: an obtaining unit configured to obtain the indoor dry-bulb temperature, the indoor dew-point temperature, the suction superheat of the first indoor heat exchanger, and the suction superheat of the second indoor heat exchanger after the air conditioner starts operating; a control unit configured to determine a control strategy for controlling the operating frequency of the compressor of the air conditioner according to the size of the indoor dry-bulb temperature, so as to control the compressor to operate; the control unit is configured to determine a control strategy for controlling the rotating speed of the inner fan according to the size of the indoor dew-point temperature, so as to control the inner fan to operate; the control unit is configured to determine a control strategy for controlling the opening degree of the first branch throttling component and the opening degree of the second branch throttling component according to the sizes of the suction superheat of the first indoor heat exchanger and the suction superheat of the second indoor heat exchanger, so as to control the first branch throttling component and the second branch throttling component to operate; wherein the control strategy for controlling the operating frequency of the compressor of the air conditioner comprises a PD feedback control strategy and a heat load and wet load control strategy; the control strategy for controlling the rotating speed of the inner fan comprises a PD feedback control strategy and a heat load and wet load control strategy; and the control strategy for controlling the opening degree of the first branch throttling component and the opening degree of the second branch throttling component comprises a PD feedback control strategy and a fitting formula control strategy; the PD feedback control strategy comprises controlling the compressor to operate according to the result of calculating the operating frequency of the compressor according to a first formula, controlling the inner fan to operate according to the result of calculating the rotating speed of the inner fan according to a second formula, controlling the first branch throttling component to operate according to the result of calculating the opening degree of the first branch throttling component according to a third formula, and controlling the second branch throttling component to operate according to the result of calculating the opening degree of the second branch throttling component according to a fourth formula; the heat load and wet load control strategy comprises controlling the compressor to operate according to the result of calculating the operating frequency of the compressor according to a fifth formula and controlling the inner fan to operate according to the result of calculating the rotating speed of the inner fan according to a sixth formula; determining the size of the absolute value of the difference between the indoor dry-bulb temperature and the indoor set temperature; ​ If the absolute value of the difference between the indoor dry-bulb temperature and the indoor set temperature is less than a first temperature difference value, the control strategy for the operating frequency of the compressor of the air conditioner is controlled to be the result of calculating the operating frequency of the compressor according to a first formula in the PD feedback control; If the absolute value of the difference between the indoor dry-bulb temperature and the indoor set temperature is greater than or equal to the first temperature difference value, the control strategy for the operating frequency of the compressor of the air conditioner is controlled to be the result of calculating the operating frequency of the compressor according to a fifth formula in the heat load and humidity load control; and / or, The control strategy for the rotating speed of the indoor fan is determined according to the size of the indoor dew-point temperature, comprising: judging the size of the absolute value of the difference between the indoor dew-point temperature and the indoor set dew-point temperature; If the absolute value of the difference between the indoor dew-point temperature and the indoor set dew-point temperature is less than a second temperature difference value, the control strategy for the rotating speed of the indoor fan is controlled to be the result of calculating the rotating speed of the indoor fan according to a second formula in the PD feedback control; If the absolute value of the difference between the indoor dew-point temperature and the indoor set dew-point temperature is greater than or equal to the second temperature difference value, the control strategy for the rotating speed of the indoor fan is controlled to be the result of calculating the rotating speed of the indoor fan according to a sixth formula in the heat load and humidity load control.

7. An air conditioner characterized by comprising: comprising: The control device of the air conditioner according to claim 6.

8. A storage medium, characterized by The storage medium comprises a stored program, wherein when the program is executed, the device where the storage medium is located performs the control method of the air conditioner according to any one of claims 1 to 5.

9. A computer program product comprising a computer program, characterized in that, The computer program is executed by a processor to implement the steps of the control method of the air conditioner according to any one of claims 1 to 5.

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