阅读说明：本技术 一种多联内机电子膨胀阀控制方法、系统及多联内机 (Control method and system for electronic expansion valve of multi-connected indoor unit and multi-connected indoor unit ) 是由 张稳 刘合心 刘永超 程相欣 于 2020-09-14 设计创作，主要内容包括：本发明提供了一种多联内机电子膨胀阀控制方法、系统及多联内机,涉及空调技术领域,所述多联内机电子膨胀阀控制方法包括根据多联内机需求的总冷媒流量、第一电子膨胀阀和第二电子膨胀阀的最大冷媒流量,确定第一电子膨胀阀的第一冷媒流量和第二电子膨胀阀的第二冷媒流量；根据第一冷媒流量和第二冷媒流量分别计算第一电子膨胀阀的第一开度值和第二电子膨胀阀的第二开度值,并根据第一开度值控制第一电子膨胀阀的开度,以及根据第二开度值控制第二电子膨胀阀到的开度。本发明通过多联内机需求的总冷媒流量,对各电子膨胀阀的流量进行精准分配,以控制各电子膨胀阀的开度,减少电子膨胀阀开度往复波动,提高调节精准度,提升用户舒适体验。(The invention provides a method and a system for controlling an electronic expansion valve of a multi-connected indoor unit and the multi-connected indoor unit, and relates to the technical field of air conditioners, wherein the method for controlling the electronic expansion valve of the multi-connected indoor unit comprises the steps of determining the first refrigerant flow of a first electronic expansion valve and the second refrigerant flow of a second electronic expansion valve according to the total refrigerant flow required by the multi-connected indoor unit and the maximum refrigerant flow of the first electronic expansion valve and the maximum refrigerant flow of the second electronic expansion valve; and respectively calculating a first opening degree value of the first electronic expansion valve and a second opening degree value of the second electronic expansion valve according to the first refrigerant flow and the second refrigerant flow, controlling the opening degree of the first electronic expansion valve according to the first opening degree value, and controlling the opening degree of the second electronic expansion valve according to the second opening degree value. According to the invention, the flow of each electronic expansion valve is accurately distributed through the total refrigerant flow required by the multi-connected indoor unit, so that the opening degree of each electronic expansion valve is controlled, the reciprocating fluctuation of the opening degree of the electronic expansion valve is reduced, the adjustment accuracy is improved, and the comfortable experience of users is promoted.)

1. The control method of the electronic expansion valve of the multi-connected indoor unit is characterized in that the multi-connected indoor unit comprises a first electronic expansion valve (1) and a second electronic expansion valve (2) which are arranged in a refrigerant pipeline in parallel, and the control method of the electronic expansion valve of the multi-connected indoor unit comprises the following steps:

acquiring the total refrigerant flow required by the multi-connected indoor unit, the maximum refrigerant flow of the first electronic expansion valve (1) and the maximum refrigerant flow of the second electronic expansion valve (2);

determining a first refrigerant flow of the first electronic expansion valve (1) and a second refrigerant flow of the second electronic expansion valve (2) according to the total refrigerant flow required by the multi-connected indoor unit, the maximum refrigerant flow of the first electronic expansion valve (1) and the maximum refrigerant flow of the second electronic expansion valve (2);

respectively calculating a first opening degree value of the first electronic expansion valve (1) and a second opening degree value of the second electronic expansion valve (2) according to the first refrigerant flow and the second refrigerant flow, controlling the opening degree of the first electronic expansion valve (1) according to the first opening degree value, and controlling the opening degree of the second electronic expansion valve (2) according to the second opening degree value.

2. The method for controlling a multiple indoor unit electronic expansion valve according to claim 1, wherein the maximum refrigerant flow rate of the first electronic expansion valve (1) and the maximum refrigerant flow rate of the second electronic expansion valve (2) satisfy the following relation:

Qmax_EV2 = γ * Qmax_EV1

Qmax_EV1+ Qmax_EV2 ≥ Qmax_EV ；

wherein Qmax _ EV1 is the maximum refrigerant flow rate of the first electronic expansion valve (1), Qmax _ EV2 is the maximum refrigerant flow rate of the second electronic expansion valve (2), Qmax _ EV is the maximum value of the refrigerant target flow control section, γ is the maximum flow coefficient, and 0 < γ < 1.

3. The method for controlling an electronic expansion valve of a multi-connected indoor unit according to claim 2, wherein the determining a first refrigerant flow rate of the first electronic expansion valve (1) and a second refrigerant flow rate of the second electronic expansion valve (2) according to a total refrigerant flow rate required by the multi-connected indoor unit comprises: and comparing the total refrigerant flow required by the multi-connected indoor unit with the maximum refrigerant flow of the first electronic expansion valve (1) and the maximum refrigerant flow of the second electronic expansion valve (2), and determining the first refrigerant flow of the first electronic expansion valve (1) and the second refrigerant flow of the second electronic expansion valve (2) according to the comparison result.

4. The multiple indoor unit electronic expansion valve control method according to claim 3, wherein the comparing the total refrigerant flow demanded by the multiple indoor unit with the maximum refrigerant flow of the first electronic expansion valve (1) and the maximum refrigerant flow of the second electronic expansion valve (2), and determining the first refrigerant flow of the first electronic expansion valve (1) and the second refrigerant flow of the second electronic expansion valve (2) according to the comparison result comprises:

when Q _ EV > Qmax _ EV1,

q _ EV1 = Qmax _ EV1, and Q _ EV2 = Q _ EV-Qmax _ EV 1;

wherein Q _ EV is a total refrigerant flow rate required by the multi-connected indoor unit, Q _ EV1 is a first refrigerant flow rate, and Q _ EV2 is a second refrigerant flow rate.

5. The method for controlling a multiple indoor unit electronic expansion valve according to claim 4, wherein the step of comparing the total refrigerant flow demanded by the multiple indoor unit with the maximum refrigerant flow of the first electronic expansion valve (1) and the maximum refrigerant flow of the second electronic expansion valve (2), and determining the first refrigerant flow of the first electronic expansion valve (1) and the second refrigerant flow of the second electronic expansion valve (2) according to the comparison result further comprises:

when Qmax _ EV1 < a Qmax _ EV2, b Qmax _ EV 2Q _ EV Qmax _ EV1,

q _ EV1 = c × Q _ EV, and Q _ EV2 = d × Q _ EV;

the method comprises the following steps that A, Q _ EV2 and a are respectively set, wherein Q _ EV is the total refrigerant flow required by the multi-connected indoor unit, Q _ EV1 is the first refrigerant flow, Q _ EV2 is the second refrigerant flow, a is the first flow coefficient, and a is more than 1 and less than or equal to 1.5; b is a second flow coefficient, and b is more than or equal to 0.5 and less than 1; c is a first scaling factor, d is a second scaling factor, c + d =1, and

c = ( Q_EV - b * Qmax_EV2 ) / ( a * Qmax_EV2 - b * Qmax_EV2 )

d = ( a * Qmax_EV2 - Q_EV ) / ( a * Qmax_EV2 - b * Qmax_EV2 )。

6. the method for controlling a multiple indoor unit electronic expansion valve according to claim 4, wherein the step of comparing the total refrigerant flow demanded by the multiple indoor unit with the maximum refrigerant flow of the first electronic expansion valve (1) and the maximum refrigerant flow of the second electronic expansion valve (2), and determining the first refrigerant flow of the first electronic expansion valve (1) and the second refrigerant flow of the second electronic expansion valve (2) according to the comparison result further comprises:

when Qmax _ EV1 is greater than or equal to a, Qmax _ EV2, a, Qmax _ EV2 < Q _ EV and Qmax _ EV1

Q _ EV1 = Q _ EV, and Q _ EV2 = 0;

wherein Q _ EV is the total refrigerant flow required by the multi-connected indoor unit, Q _ EV1 is the first refrigerant flow, Q _ EV2 is the second refrigerant flow, a is the first flow coefficient, and a is more than 1 and less than or equal to 1.5.

7. The method for controlling a multiple indoor unit electronic expansion valve according to claim 4, wherein the step of comparing the total refrigerant flow demanded by the multiple indoor unit with the maximum refrigerant flow of the first electronic expansion valve (1) and the maximum refrigerant flow of the second electronic expansion valve (2), and determining the first refrigerant flow of the first electronic expansion valve (1) and the second refrigerant flow of the second electronic expansion valve (2) according to the comparison result further comprises:

when Qmax _ EV1 is more than or equal to a × Qmax _ EV2, b × Qmax _ EV2 is more than or equal to Q _ EV is more than or equal to a × Qmax _ EV2,

q _ EV1 = c × Q _ EV, and Q _ EV2 = d × Q _ EV;

the method comprises the following steps that A, Q _ EV2 and a are respectively set, wherein Q _ EV is the total refrigerant flow required by the multi-connected indoor unit, Q _ EV1 is the first refrigerant flow, Q _ EV2 is the second refrigerant flow, a is the first flow coefficient, and a is more than 1 and less than or equal to 1.5; b is a second flow coefficient, and b is more than or equal to 0.5 and less than 1; c is a first scaling factor, d is a second scaling factor, c + d =1, and

c = ( Q_EV - b * Qmax_EV2 ) / ( a * Qmax_EV2 - b * Qmax_EV2 )

d = ( a * Qmax_EV2 - Q_EV ) / ( a * Qmax_EV2 - b * Qmax_EV2 )。

8. the method for controlling a multiple indoor unit electronic expansion valve according to claim 3, wherein the step of comparing the total refrigerant flow demanded by the multiple indoor unit with the maximum refrigerant flow of the first electronic expansion valve (1) and the maximum refrigerant flow of the second electronic expansion valve (2), and determining the first refrigerant flow of the first electronic expansion valve (1) and the second refrigerant flow of the second electronic expansion valve (2) according to the comparison result further comprises:

when Q _ EV < b x Qmax _ EV2,

q _ EV1 =0, and Q _ EV2 = Q _ EV;

and Q _ EV is the total refrigerant flow required by the multi-connected indoor unit, Q _ EV1 is the first refrigerant flow, Q _ EV2 is the second refrigerant flow, b is the second flow coefficient, and b is more than or equal to 0.5 and less than 1.

9. The utility model provides a many internal machines electronic expansion valve control system that ally oneself with which characterized in that includes:

an obtaining unit, which is used for obtaining the total refrigerant flow required by the multi-connected indoor unit,

the calculating unit is used for calculating the first refrigerant flow of the first electronic expansion valve (1) and the second refrigerant flow of the second electronic expansion valve (2) according to the total refrigerant flow required by the multi-connected indoor unit;

the calculating unit is further used for calculating a first opening value of the first electronic expansion valve (1) and a second opening value of the second electronic expansion valve (2) according to the first refrigerant flow and the second refrigerant flow;

the control unit is used for controlling the opening degree of the first electronic expansion valve (1) according to the first opening degree value, and the control unit is used for controlling the opening degree of the second electronic expansion valve (2) according to the second opening degree value.

10. A multiple indoor unit, comprising a computer-readable storage medium storing a computer program and a processor, wherein the computer program is read by the processor and executed to implement the method for controlling an electronic expansion valve of a multiple indoor unit according to any one of claims 1 to 8.

Technical Field

The invention relates to the technical field of air conditioners, in particular to a method and a system for controlling an electronic expansion valve of a multi-connected indoor unit and the multi-connected indoor unit.

Background

Disclosure of Invention

The invention solves the problem that when the demand of the machine set on the refrigerant flow is small, the sensitivity of valve flow adjustment is insufficient, so that the expansion valve is continuously adjusted and fluctuated nearby the demand, the system stability is insufficient, and the use comfort of a customer is influenced.

In order to solve the above problems, the present invention provides a method for controlling an electronic expansion valve of a multiple indoor unit, where the multiple indoor unit includes a first electronic expansion valve and a second electronic expansion valve that are arranged in parallel in a refrigerant pipeline, and the method for controlling the electronic expansion valve of the multiple indoor unit includes:

acquiring the total refrigerant flow required by the multi-connected indoor unit, the maximum refrigerant flow of the first electronic expansion valve and the maximum refrigerant flow of the second electronic expansion valve;

determining a first refrigerant flow of the first electronic expansion valve and a second refrigerant flow of the second electronic expansion valve according to the total refrigerant flow required by the multi-connected indoor unit, the maximum refrigerant flow of the first electronic expansion valve and the maximum refrigerant flow of the second electronic expansion valve;

respectively calculating a first opening value of the first electronic expansion valve and a second opening value of the second electronic expansion valve according to the first refrigerant flow and the second refrigerant flow, controlling the opening of the first electronic expansion valve according to the first opening value, and controlling the opening of the second electronic expansion valve according to the second opening value.

Therefore, the flow of each electronic expansion valve is accurately distributed through the total refrigerant flow required by the multi-connected indoor unit, so that the opening degree of each electronic expansion valve is controlled, the reciprocating fluctuation of the opening degree of each electronic expansion valve is reduced, the adjusting precision is improved, and the comfortable experience of users is improved.

Optionally, the maximum refrigerant flow rate of the first electronic expansion valve and the maximum refrigerant flow rate of the second electronic expansion valve satisfy the following relation:

Qmax_EV2 = γ * Qmax_EV1

Qmax_EV1+ Qmax_EV2 ≥ Qmax_EV；

wherein Qmax _ EV1 is the maximum refrigerant flow rate of the first electronic expansion valve, Qmax _ EV2 is the maximum refrigerant flow rate of the second electronic expansion valve, Qmax _ EV is the maximum value of the refrigerant target flow control section, γ is the maximum flow coefficient, and 0 < γ < 1.

Therefore, the total refrigerant flow required by the multi-connected indoor unit can be met, and when the multi-connected indoor unit is used for different flow demands, the electronic expansion valves are effectively switched, and meanwhile, the waste caused by too large type selection is avoided.

Optionally, the determining a first refrigerant flow of the first electronic expansion valve and a second refrigerant flow of the second electronic expansion valve according to the total refrigerant flow required by the multi-connected indoor unit includes: and comparing the total refrigerant flow required by the multi-connected indoor unit with the maximum refrigerant flow of the first electronic expansion valve and the maximum refrigerant flow of the second electronic expansion valve, and determining the first refrigerant flow of the first electronic expansion valve and the second refrigerant flow of the second electronic expansion valve according to the comparison result.

Therefore, the total refrigerant flow required by the multi-connected indoor unit is compared with the maximum refrigerant flow of the first electronic expansion valve and the maximum refrigerant flow of the second electronic expansion valve, so that a buffer area is formed by distributing the total refrigerant flow required by the multi-connected indoor unit at the flow of the first electronic expansion valve and the flow of the second electronic expansion valve, the opening degrees of the first electronic expansion valve and the second electronic expansion valve are continuously changed, the flow is stably transited, and accurate control can be realized.

Optionally, the comparing the total refrigerant flow required by the multiple indoor unit with the maximum refrigerant flow of the first electronic expansion valve and the maximum refrigerant flow of the second electronic expansion valve, and determining the first refrigerant flow of the first electronic expansion valve and the second refrigerant flow of the second electronic expansion valve according to the comparison result includes:

when Q _ EV > Qmax _ EV1,

q _ EV1 = Qmax _ EV1, and Q _ EV2 = Q _ EV-Qmax _ EV 1;

wherein Q _ EV is a total refrigerant flow rate required by the multi-connected indoor unit, Q _ EV1 is a first refrigerant flow rate, and Q _ EV2 is a second refrigerant flow rate.

Therefore, when the total refrigerant flow required by the multi-connected indoor unit is greater than the maximum refrigerant flow of the first electronic expansion valve, the first refrigerant flow is the maximum refrigerant flow of the first electronic expansion valve, and the second refrigerant flow is the difference value between the total refrigerant flow required by the multi-connected indoor unit and the maximum refrigerant flow of the first electronic expansion valve, so that the first electronic expansion valve and the second electronic expansion valve are accurately controlled.

Optionally, the comparing the total refrigerant flow required by the multiple indoor unit with the maximum refrigerant flow of the first electronic expansion valve and the maximum refrigerant flow of the second electronic expansion valve, and determining the first refrigerant flow of the first electronic expansion valve and the second refrigerant flow of the second electronic expansion valve according to the comparison result further includes:

when Qmax _ EV1 < a Qmax _ EV2, b Qmax _ EV 2Q _ EV Qmax _ EV1,

q _ EV1 = c × Q _ EV, and Q _ EV2 = d × Q _ EV;

the method comprises the following steps that A, Q _ EV2 and a are respectively set, wherein Q _ EV is the total refrigerant flow required by the multi-connected indoor unit, Q _ EV1 is the first refrigerant flow, Q _ EV2 is the second refrigerant flow, a is the first flow coefficient, and a is more than 1 and less than or equal to 1.5; b is a second flow coefficient, and b is more than or equal to 0.5 and less than 1; c is a first scaling factor, d is a second scaling factor, c + d =1, and

c = ( Q_EV - b * Qmax_EV2 ) / ( a * Qmax_EV2 - b * Qmax_EV2 )

d = ( a * Qmax_EV2 - Q_EV ) / ( a * Qmax_EV2 - b * Qmax_EV2 )。

therefore, the maximum flow of the first electronic expansion valve is less than a times of the maximum flow of the second electronic expansion valve, and when the total refrigerant flow required by the multi-connected indoor unit is not less than b times of the maximum flow of the second electronic expansion valve and not more than the maximum flow of the first electronic expansion valve, the first electronic expansion valve and the second electronic expansion valve both have opening requirements, so as to realize accurate control of the first electronic expansion valve and the second electronic expansion valve.

Optionally, the comparing the total refrigerant flow required by the multiple indoor unit with the maximum refrigerant flow of the first electronic expansion valve and the maximum refrigerant flow of the second electronic expansion valve, and determining the first refrigerant flow of the first electronic expansion valve and the second refrigerant flow of the second electronic expansion valve according to the comparison result further includes:

q _ EV1 = Q _ EV and Q _ EV2 =0 when Qmax _ EV1 ≧ a _ Qmax _ EV2, a _ Qmax _ EV2 < Q _ EV ≦ Qmax _ EV 1;

wherein Q _ EV is the total refrigerant flow required by the multi-connected indoor unit, Q _ EV1 is the first refrigerant flow, Q _ EV2 is the second refrigerant flow, a is the first flow coefficient, and a is more than 1 and less than or equal to 1.5.

Therefore, when the total refrigerant flow required by the multi-connected indoor unit is more than a times of the maximum flow of the second electronic expansion valve and not more than the maximum flow of the first electronic expansion valve, the second electronic expansion valve has no opening demand, and the first refrigerant flow of the first electronic expansion valve is the total refrigerant flow required by the multi-connected indoor unit, so that the first electronic expansion valve and the second electronic expansion valve are accurately controlled.

Optionally, the comparing the total refrigerant flow required by the multiple indoor unit with the maximum refrigerant flow of the first electronic expansion valve and the maximum refrigerant flow of the second electronic expansion valve, and determining the first refrigerant flow of the first electronic expansion valve and the second refrigerant flow of the second electronic expansion valve according to the comparison result further includes:

when Qmax _ EV1 is more than or equal to a × Qmax _ EV2, b × Qmax _ EV2 is more than or equal to Q _ EV is more than or equal to a × Qmax _ EV2,

q _ EV1 = c × Q _ EV, and Q _ EV2 = d × Q _ EV;

the method comprises the following steps that A, Q _ EV2 and a are respectively set, wherein Q _ EV is the total refrigerant flow required by the multi-connected indoor unit, Q _ EV1 is the first refrigerant flow, Q _ EV2 is the second refrigerant flow, a is the first flow coefficient, and a is more than 1 and less than or equal to 1.5; b is a second flow coefficient, and b is more than or equal to 0.5 and less than 1; c is a first scaling factor, d is a second scaling factor, c + d =1, and

c = ( Q_EV - b * Qmax_EV2 ) / ( a * Qmax_EV2 - b * Qmax_EV2 )

d = ( a * Qmax_EV2 - Q_EV ) / ( a * Qmax_EV2 - b * Qmax_EV2 )。

therefore, when the maximum flow of the first electronic expansion valve is not less than a times of the maximum flow of the second electronic expansion valve and the total refrigerant flow required by the multi-connected indoor unit is not less than b times of the maximum flow of the second electronic expansion valve and not more than a times of the maximum flow of the second electronic expansion valve, the first electronic expansion valve and the second electronic expansion valve both have opening requirements, so that the first electronic expansion valve and the second electronic expansion valve can be accurately controlled.

Optionally, the comparing the total refrigerant flow required by the multiple indoor unit with the maximum refrigerant flow of the first electronic expansion valve and the maximum refrigerant flow of the second electronic expansion valve, and determining the first refrigerant flow of the first electronic expansion valve and the second refrigerant flow of the second electronic expansion valve according to the comparison result further includes:

when Q _ EV < b x Qmax _ EV2,

q _ EV1 =0, and Q _ EV2 = Q _ EV;

and Q _ EV is the total refrigerant flow required by the multi-connected indoor unit, Q _ EV1 is the first refrigerant flow, Q _ EV2 is the second refrigerant flow, b is the second flow coefficient, and b is more than or equal to 0.5 and less than 1.

Therefore, when the total refrigerant flow required by the multi-connected indoor unit is less than b times of the maximum flow of the second electronic expansion valve, the first electronic expansion valve has no opening requirement, and the second refrigerant flow of the second electronic expansion valve is the total refrigerant flow required by the multi-connected indoor unit, so that the first electronic expansion valve and the second electronic expansion valve are accurately controlled.

Compared with the prior art, the method for controlling the electronic expansion valve of the multi-connected indoor unit compares the total refrigerant flow required by the multi-connected indoor unit with the maximum refrigerant flow of the first electronic expansion valve and the maximum refrigerant flow of the second electronic expansion valve, and accurately distributes the flow of each electronic expansion valve so as to control the opening degree of each electronic expansion valve, reduce the reciprocating fluctuation of the opening degree of the electronic expansion valve, improve the adjustment accuracy and improve the comfortable experience of users.

In order to solve the above technical problem, the present invention further provides a control system for an electronic expansion valve of a multi-connected indoor unit, comprising:

an obtaining unit, which is used for obtaining the total refrigerant flow required by the multi-connected indoor unit,

the calculating unit is used for calculating the first refrigerant flow of the first electronic expansion valve and the second refrigerant flow of the second electronic expansion valve according to the total refrigerant flow required by the multi-connected indoor unit;

the calculating unit is further used for calculating a first opening value of the first electronic expansion valve and a second opening value of the second electronic expansion valve according to the first refrigerant flow and the second refrigerant flow;

and the control unit is used for controlling the opening degree of the first electronic expansion valve according to the first opening value, and the control unit is used for controlling the opening degree of the second electronic expansion valve according to the second opening value.

Compared with the prior art, the control system and the control method of the electronic expansion valve of the multi-connected indoor unit have the same advantages, and are not described again.

In order to solve the technical problem, the invention further provides a multiple internal unit, which comprises a computer readable storage medium storing a computer program and a processor, wherein the computer program is read by the processor and runs to realize the control method of the electronic expansion valve of the multiple internal unit.

Compared with the prior art, the multi-connected indoor unit and the control method of the electronic expansion valve of the multi-connected indoor unit have the same advantages, and are not described herein again.

Drawings

Fig. 1 is a first flowchart of a method for controlling an electronic expansion valve of a multi-connected indoor unit in an embodiment of the invention;

fig. 2 is a second flowchart of a method for controlling an electronic expansion valve of a multi-connected indoor unit according to an embodiment of the invention;

FIG. 3 is a schematic diagram of a scale model for calculating a first scaling factor and a second scaling factor according to an embodiment of the present invention;

fig. 4 is a schematic structural diagram of a multiple internal unit in the embodiment of the invention.

Description of the reference numerals

1. The system comprises a first electronic expansion valve, a 2-second electronic expansion valve, a 3-air pipe joint, a 4-heat exchanger, a 5-throttle valve, a 6-fan and a 7-liquid pipe joint.

Detailed Description

In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in detail below.

In the description of the present invention, it is to be understood that the terms "first", "second" and the like are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implying any number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. The description of the term "some specific embodiments" means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. Throughout this specification, the schematic representations of the terms used above do not necessarily refer to the same implementation or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

As shown in fig. 1, an embodiment of the present invention provides a method for controlling an electronic expansion valve of a multiple indoor unit, where the multiple indoor unit includes a first electronic expansion valve 1 and a second electronic expansion valve 2 that are arranged in parallel in a refrigerant pipeline, and the method for controlling the electronic expansion valve of the multiple indoor unit includes:

step S1, acquiring the total refrigerant flow required by the multi-connected indoor unit, the maximum refrigerant flow of the first electronic expansion valve 1 and the maximum refrigerant flow of the second electronic expansion valve 2;

step S2, determining a first refrigerant flow of the first electronic expansion valve 1 and a second refrigerant flow of the second electronic expansion valve 2 according to the total refrigerant flow required by the multi-connected indoor unit, the maximum refrigerant flow of the first electronic expansion valve 1 and the maximum refrigerant flow of the second electronic expansion valve 2;

step S3, calculating a first opening degree value of the first electronic expansion valve 1 and a second opening degree value of the second electronic expansion valve 2 according to the first refrigerant flow and the second refrigerant flow, controlling the opening degree of the first electronic expansion valve 1 according to the first opening degree value, and controlling the opening degree of the second electronic expansion valve 2 according to the second opening degree value.

Therefore, the flow of each electronic expansion valve is accurately distributed through the total refrigerant flow required by the multi-connected indoor unit, the maximum refrigerant flow of the first electronic expansion valve 1 and the maximum refrigerant flow of the second electronic expansion valve 2, so that the opening degree of each electronic expansion valve is controlled, the opening degree reciprocating fluctuation of the electronic expansion valves is reduced, the adjusting precision is improved, and the comfortable experience of users is improved.

In this embodiment, the total refrigerant flow required by the multiple indoor unit is the sum of the first refrigerant flow of the first electronic expansion valve 1 and the second refrigerant flow of the second electronic expansion valve 2.

Preferably, the maximum refrigerant flow rate of the first electronic expansion valve 1 and the maximum refrigerant flow rate of the second electronic expansion valve 2 satisfy the following relation:

Qmax_EV2 = γ * Qmax_EV1

Qmax_EV1+ Qmax_EV2 ≥ Qmax_EV，

wherein Qmax _ EV1 is the maximum refrigerant flow rate of the first electronic expansion valve 1, Qmax _ EV2 is the maximum refrigerant flow rate of the second electronic expansion valve 2, Qmax _ EV is the maximum value of the refrigerant target flow control section, γ is the maximum flow coefficient, and 0 < γ < 1. Therefore, the total refrigerant flow required by the multi-connected indoor unit can be met, and when the multi-connected indoor unit is used for different flow demands, the electronic expansion valves are effectively switched, and meanwhile, the waste caused by too large type selection is avoided. In this embodiment, the refrigerant target flow control interval is determined by the opening degree of the electronic expansion valve in the multi-split air conditioner, when the refrigerant flow is designed for the multi-split air conditioner, the refrigerant flow is generally determined by the opening degree of the electronic expansion valve in the multi-split air conditioner, the minimum value of the general refrigerant flow is 0, and the maximum value of the refrigerant flow is the maximum value of the opening degree of the electronic expansion valve.

In some preferred embodiments, γ is greater than or equal to 1/3 and less than or equal to 1/2, so that the flow rates of the two electronic expansion valves are selected differently to meet different flow rate requirements, and the electronic expansion valve with the smaller type is selected to better realize accurate control. In some specific embodiments, γ is 2/5, which avoids waste caused by too large a model selection, and better realizes precise control.

In this embodiment, according to the factory characteristic curve of the electronic expansion valve, the first refrigerant flow rate of the first electronic expansion valve 1 and the opening degree value of the first electronic expansion valve 1 may be obtained through a fitting function, that is, the first refrigerant flow rate of the first electronic expansion valve 1 and the opening degree value of the first electronic expansion valve 1 satisfy the following relation: p _ EV1 = f^-1(Q _ EV1), where P _ EV1 is the opening degree value of the first electronic expansion valve 1, f^-1(Q _ EV1) is an expression in mathematics for the inverse function of Q _ EV 1; similarly, the second refrigerant flow rate of the second electronic expansion valve 2 and the opening degree value of the second electronic expansion valve 2 may be obtained through a fitting function, that is, the second refrigerant flow rate of the second electronic expansion valve 2 and the opening degree value of the second electronic expansion valve 2 satisfy the following relation: p _ EV2 = f^-1(Q _ EV2), where P _ EV2 is the opening degree value of the second electronic expansion valve 2, f^-1(Q _ EV2) is mathematically related to Q _ EV2An expression of an inverse function.

Therefore, in this embodiment, P _ EV1 = f^-1(Q _ EV1) and P _ EV2 = f^-1(Q _ EV2), a first opening degree of the first electronic expansion valve 1 and a second opening degree of the second electronic expansion valve 2 are calculated according to the first refrigerant flow rate and the second refrigerant flow rate, the opening degree of the first electronic expansion valve 1 is controlled according to the first opening degree, and the opening degree of the second electronic expansion valve 2 is controlled according to the second opening degree.

Preferably, determining a first refrigerant flow of the first electronic expansion valve 1 and a second refrigerant flow of the second electronic expansion valve 2 according to a total refrigerant flow required by the multi-split indoor unit includes: and comparing the total refrigerant flow required by the multi-connected indoor unit with the maximum refrigerant flow of the first electronic expansion valve 1 and the maximum refrigerant flow of the second electronic expansion valve 2, and determining the first refrigerant flow of the first electronic expansion valve 1 and the second refrigerant flow of the second electronic expansion valve 2 according to the comparison result. Therefore, the total refrigerant flow required by the multi-connected indoor unit is compared with the maximum refrigerant flow of the first electronic expansion valve 1 and the maximum refrigerant flow of the second electronic expansion valve 2, so that a buffer area is formed by distributing the total refrigerant flow required by the multi-connected indoor unit at the flow of the first electronic expansion valve 1 and the flow of the second electronic expansion valve 2, the opening degrees of the first electronic expansion valve 1 and the second electronic expansion valve 2 are continuously changed, the flow is stably transited, and accurate control can be realized.

As shown in fig. 2, preferably, the comparing the total refrigerant flow rate required by the multi-connected indoor unit with the maximum refrigerant flow rate of the first electronic expansion valve 1 and the maximum refrigerant flow rate of the second electronic expansion valve 2, and determining the first refrigerant flow rate of the first electronic expansion valve 1 and the second refrigerant flow rate of the second electronic expansion valve 2 according to the comparison result includes:

when Q _ EV > Qmax _ EV1,

q _ EV1 = Qmax _ EV1, and Q _ EV2 = Q _ EV-Qmax _ EV 1;

the refrigerant flow rate Q _ EV is a total refrigerant flow rate required by the multi-split indoor unit, the refrigerant flow rate Q _ EV1 is a first refrigerant flow rate, and the refrigerant flow rate Q _ EV2 is a second refrigerant flow rate.

Then, the opening degree of the first electronic expansion valve 1 is P _ EV1 = f^-1(Q_EV1) ；

The opening degree of the second electronic expansion valve 2 is P _ EV2 = f^-1(Q_EV2) 。

Therefore, when the total refrigerant flow required by the multi-connected indoor unit is greater than the maximum refrigerant flow of the first electronic expansion valve 1, the first refrigerant flow is the maximum refrigerant flow of the first electronic expansion valve 1, and the second refrigerant flow is the difference value between the total refrigerant flow required by the multi-connected indoor unit and the maximum refrigerant flow of the first electronic expansion valve 1, so that the first electronic expansion valve 1 and the second electronic expansion valve 2 are accurately controlled.

When Qmax _ EV1 < a Qmax _ EV2, b Qmax _ EV 2Q _ EV Qmax _ EV1,

q _ EV1 = c × Q _ EV, and Q _ EV2 = d × Q _ EV,

the method comprises the following steps that A, Q _ EV2 and a are respectively set, wherein Q _ EV is the total refrigerant flow required by the multi-connected indoor unit, Q _ EV1 is the first refrigerant flow, Q _ EV2 is the second refrigerant flow, a is the first flow coefficient, and a is more than 1 and less than or equal to 1.5; b is a second flow coefficient, and b is more than or equal to 0.5 and less than 1;

wherein a is a first flow coefficient, in some preferred embodiments, a is greater than 1 and less than or equal to 1.5, and when the total refrigerant flow required by the multi-split indoor unit is greater than 1.5 times of the maximum flow of the second electronic expansion valve 2, the second electronic expansion valve 2 has no opening requirement. When the total refrigerant flow required by the multi-connected indoor unit is close to the maximum flow of the second electronic expansion valve 2, the second electronic expansion valve 2 has an opening requirement, conditions are provided for effective switching among the electronic expansion valves, and smooth switching of the electronic expansion valves is guaranteed.

And b is a second flow coefficient, in some preferred embodiments, b is more than or equal to 0.5 and less than 1, when the total refrigerant flow required by the multi-split indoor unit is smaller and is far away from the maximum flow of the second electronic expansion valve 2, the first electronic expansion valve 1 does not have an opening requirement, and only the second electronic expansion valve 2 is opened at the moment, so that more accurate control is realized.

Wherein c is a first scaling factor, d is a second scaling factor, and c + d =1,

and each flow is represented by a line segment according to the scale rule principle in the mathematical theory, as shown in figure 3,

suppose that: the longest length is: a, Qmax _ EV2, the shortest length being: b, Qmax _ EV2, the required length: q _ EV

Then: length segment c' = (Q _ EV-b × Qmax _ EV2),

length segment d' = (a × Qmax _ EV2-Q _ EV),

length segment c '+ d' = (a × Qmax _ EV2-b × Qmax _ EV2),

then: the first scaling factor c = c '/(c ' + d ') = (Q _ EV-b × Qmax _ EV 2)/(a × Qmax _ EV2-b × Qmax _ EV2),

the second scaling factor d = d '/(c ' + d ') = (a × Qmax _ EV2-Q _ EV)/(a × Qmax _ EV2-b × Qmax _ EV 2).

Then, the opening degree of the first electronic expansion valve 1 is P _ EV1 = f^-1(Q_EV1) ；

The opening degree of the second electronic expansion valve 2 is P _ EV2 = f^-1(Q_EV2)。

Therefore, the maximum flow of the first electronic expansion valve is less than a times of the maximum flow of the second electronic expansion valve, and when the total refrigerant flow required by the multi-connected indoor unit is not less than b times of the maximum flow of the second electronic expansion valve and not more than the maximum flow of the first electronic expansion valve, the first electronic expansion valve and the second electronic expansion valve both have opening requirements, so as to realize accurate control of the first electronic expansion valve and the second electronic expansion valve.

When Qmax _ EV1 is more than or equal to a and Qmax _ EV2, a and Qmax _ EV2 < Q _ EV is less than or equal to Qmax _ EV1,

q _ EV1 = Q _ EV, and Q _ EV2 =0,

therefore, when the total refrigerant flow required by the multiple indoor unit is more than a times of the maximum flow of the second electronic expansion valve 2 and not more than the maximum flow of the first electronic expansion valve 1, the second electronic expansion valve 2 has no opening demand, and the first refrigerant flow of the first electronic expansion valve 1 is the total refrigerant flow required by the multiple indoor unit, so as to realize accurate control of the first electronic expansion valve 1 and the second electronic expansion valve 2.

Then, the opening degree of the first electronic expansion valve 1 is P _ EV1 = f^-1(Q_EV1)；

The opening degree of the second electronic expansion valve 2 is P _ EV2 = 0.

When Qmax _ EV1 is more than or equal to a × Qmax _ EV2, b × Qmax _ EV2 is more than or equal to Q _ EV is more than or equal to a × Qmax _ EV2,

q _ EV1 = c × Q _ EV, and Q _ EV2 = d × Q _ EV,

then, the opening degree of the first electronic expansion valve 1 is P _ EV1 = f^-1(Q_EV1)；

The opening degree of the second electronic expansion valve 2 is P _ EV2 = f^-1(Q_EV2)。

Therefore, when the maximum flow of the first electronic expansion valve is not less than a times of the maximum flow of the second electronic expansion valve and the total refrigerant flow required by the multi-connected indoor unit is not less than b times of the maximum flow of the second electronic expansion valve 2 and not more than a times of the maximum flow of the second electronic expansion valve 2, the first electronic expansion valve 1 and the second electronic expansion valve 2 both have opening requirements, so as to realize accurate control of the first electronic expansion valve 1 and the second electronic expansion valve 2.

As shown in fig. 2, when Q _ EV < b × Qmax _ EV2,

q _ EV1 =0, and Q _ EV2 = Q _ EV;

then, the opening degree of the first electronic expansion valve 1 is P _ EV1 = 0;

the opening degree of the second electronic expansion valve 2 is P _ EV2 = f^-1(Q_EV2)。

Therefore, when the total refrigerant flow required by the multi-connected indoor unit is less than b times of the maximum flow of the second electronic expansion valve 2, the first electronic expansion valve 1 has no opening requirement, and the second refrigerant flow of the second electronic expansion valve 2 is the total refrigerant flow required by the multi-connected indoor unit, so that the first electronic expansion valve 1 and the second electronic expansion valve 2 are accurately controlled.

In the prior art, in the opening control of two electronic expansion valves, when the total refrigerant flow required by the multi-connected indoor unit is close to the maximum flow of the second electronic expansion valve 2, the first electronic expansion valve 1 is closed, and the second electronic expansion valve 2 is opened. At this time, the opening degrees of the first electronic expansion valve 1 and the second electronic expansion valve 2 do not change continuously, but change abruptly. Thus, flow control product fluctuations may result. In this embodiment, when the double-flow coefficient, that is, the first flow coefficient and the second flow coefficient, is used for controlling, the total refrigerant flow required by the multi-connected indoor unit is distributed at the flow rates of the first electronic expansion valve 1 and the second electronic expansion valve 2 to form a buffer area, the opening degrees of the first electronic expansion valve 1 and the second electronic expansion valve 2 are continuously changed, the flow rates are in stable transition, and accurate control is achieved.

When the total refrigerant flow required by the multi-connected indoor unit is close to the maximum flow of the second electronic expansion valve 2, the opening degree of the first electronic expansion valve 1 is gradually reduced, and the opening degree of the second electronic expansion valve 2 is gradually increased. At this time, the opening degree of the first electronic expansion valve 1 and the opening degree of the second electronic expansion valve 2 both continuously change, and the flow rate is in smooth transition, so that accurate control is realized. When the total refrigerant flow required by the multi-connected indoor unit is smaller and is far away from the maximum flow of the second electronic expansion valve 2, the first electronic expansion valve 1 has no opening requirement, and only the second electronic expansion valve 2 is opened at the moment, so that finer control is realized.

Compared with the prior art, the control method of the multiple internal unit electronic expansion valve of the embodiment compares the total refrigerant flow required by the multiple internal unit with the maximum refrigerant flow of the first electronic expansion valve 1 and the maximum refrigerant flow of the second electronic expansion valve 2, and accurately distributes the flow of each electronic expansion valve, so as to control the opening degree of each electronic expansion valve, reduce the reciprocating fluctuation of the opening degree of the electronic expansion valve, improve the adjustment accuracy, and improve the comfortable experience of users.

The embodiment of the invention also provides a control system of the electronic expansion valve of the multi-connected indoor unit, which comprises:

the acquisition unit is used for acquiring the total refrigerant flow required by the multi-connected indoor unit,

the calculating unit is used for calculating the first refrigerant flow of the first electronic expansion valve 1 and the second refrigerant flow of the second electronic expansion valve 2 according to the total refrigerant flow required by the multi-connected indoor unit;

the calculating unit is also used for calculating a first opening value of the first electronic expansion valve 1 and a second opening value of the second electronic expansion valve 2 according to the first refrigerant flow and the second refrigerant flow;

and the control unit is used for controlling the opening degree of the first electronic expansion valve 1 according to the first opening degree value, and the control unit is used for controlling the opening degree of the second electronic expansion valve 2 according to the second opening degree value.

Compared with the prior art, the control system of the electronic expansion valve of the multi-connected indoor unit and the control method of the electronic expansion valve of the multi-connected indoor unit in the embodiment have the same advantages, and are not described herein again.

The embodiment of the invention also provides a multi-connected indoor unit, which comprises a computer readable storage medium and a processor, wherein the computer readable storage medium is used for storing a computer program, and the computer program is read by the processor and runs to realize the control method of the electronic expansion valve of the multi-connected indoor unit.

Compared with the prior art, the multiple indoor unit and the control method of the electronic expansion valve of the multiple indoor unit in the embodiment have the same advantages, and are not described herein again.

Preferably, as shown in fig. 4, the multiple internal unit in this embodiment includes a first electronic expansion valve and a second electronic expansion valve that are disposed in parallel in the refrigerant pipeline.

From this, when guaranteeing the total refrigerant flow of many internal unit demands, through the accurate control to first electronic expansion valve and second electronic expansion valve aperture, reduce the reciprocal fluctuation of expansion valve aperture, improve and adjust the precision, promote customer's comfort level.

The multi-connected indoor unit in the embodiment further comprises an inner case, and a gas pipe joint 3, a heat exchanger 4, a throttle valve 5, a fan 6 and a liquid pipe joint 7 which are arranged inside the inner case, wherein the gas pipe joint 3 and the liquid pipe joint 7 are respectively connected with the multi-connected outdoor unit, the gas pipe joint 3, the heat exchanger 4, the throttle valve 5 and the liquid pipe joint 7 are connected with each other and are connected in series in a refrigerant pipeline, and the fan 6 is arranged close to the heat exchanger 4 and used for accelerating the heat exchange rate.

The embodiment of the invention also provides a computer readable storage medium, wherein a computer program is stored in the computer readable storage medium, and when the computer program is read and operated by a processor, the method for controlling the electronic expansion valve of the multi-connected internal machine is realized.

Compared with the prior art, the advantages of the computer readable storage medium and the control method of the electronic expansion valve of the multi-connected indoor unit are the same, and are not described herein again.

Although the present invention is disclosed above, the present invention is not limited thereto. Various changes and modifications may be effected therein by one skilled in the art without departing from the spirit and scope of the invention as defined in the appended claims.