阅读说明：本技术 一种多联机室外机电子膨胀阀控制方法 (Control method for electronic expansion valve of multi-split outdoor unit ) 是由 刘红斌 麦享世 高德福 胡耀聪 朱瑞元 欧敏 李晓东 于 2019-10-31 设计创作，主要内容包括：本发明所提供的一种多联机室外机电子膨胀阀控制方法,相比现有单纯根据某个变量控制,本发明具有调节更加精准,既能保证系统排气温度控制在合理范围,又能保证排气压力在合理范围,解决了空调系统中由于冷媒量过多,排气不高,而压力过高的时候电子膨胀阀的开度更加合理,减少了电子膨胀阀的振动及噪音,提供了电子膨胀阀的可靠性及用户的舒适性体验。(Compared with the existing method for controlling the electronic expansion valve of the multi-connected outdoor unit simply according to a certain variable, the method has the advantages that the adjustment is more accurate, the control of the exhaust temperature of the system can be guaranteed within a reasonable range, the exhaust pressure can be guaranteed within a reasonable range, the problem that the opening degree of the electronic expansion valve is more reasonable when the pressure is too high due to the fact that the quantity of refrigerants is too much and the exhaust is not high in an air conditioning system is solved, the vibration and the noise of the electronic expansion valve are reduced, and the reliability of the electronic expansion valve and the comfortable experience of a user are provided.)

1. The control method of the electronic expansion valve of the multi-connected outdoor unit is characterized in that a throttling component is matched with the outdoor unit, wherein the throttling component comprises the electronic expansion valve, a one-way valve and an electromagnetic valve, the electromagnetic valve and the one-way valve are connected in series and then connected in parallel with the electronic expansion valve, and the control method of the electronic expansion valve of the multi-connected outdoor unit is characterized in that: the method comprises the following steps of presetting a multi-stage exhaust temperature regulation stage and a multi-stage exhaust pressure regulation stage, wherein each stage of exhaust temperature regulation stage or exhaust pressure regulation stage is provided with the corresponding opening size of an electronic expansion valve and the on/off requirements of an electromagnetic valve;

the control method of the throttling component comprises the following specific steps:

s1, monitoring and obtaining the current exhaust temperature Tt and the current exhaust pressure Tp of a compressor in the running process of an outdoor unit in a refrigeration mode of an air conditioning system;

s2, determining a corresponding exhaust temperature regulation stage and an exhaust pressure regulation stage based on the current exhaust temperature Tt and the exhaust pressure Tp, and determining the opening size of an electronic expansion valve and the on/off requirement of an electromagnetic valve respectively corresponding to the exhaust temperature regulation stage and the exhaust pressure regulation stage;

s3, comparing the opening degree of the electronic expansion valve corresponding to the exhaust temperature Tt and the exhaust pressure Tp to determine the maximum opening degree between the exhaust temperature Tt and the exhaust pressure Tp as a target value, so as to control the electronic expansion valve to be adjusted to the target value from the current opening degree; meanwhile, whether at least one opening requirement exists between the exhaust temperature Tt and the electromagnetic valve opening/closing requirement corresponding to the exhaust pressure Tp is determined, wherein if at least one opening requirement exists, the electromagnetic valve is controlled to be opened; on the contrary, if at least one opening requirement does not exist, the electromagnetic valve is controlled to be closed;

and S4, after the adjustment is finished, repeating the steps S2 and S3 in a circulating mode until the air conditioning system is closed.

2. The method for controlling an electronic expansion valve of an outdoor unit of a multi-connected unit according to claim 1, wherein: in step S3, comparing the determined target value with the current opening degree of the electronic expansion valve, wherein if the target value is larger than the current opening degree, controlling the opening degree of the electronic expansion valve to be directly adjusted up to the target value; otherwise, if the target value is smaller than the current opening, the electronic expansion valve is controlled to be gradually reduced from the current opening according to the exhaust temperature regulating stage or the multi-stage exhaust pressure regulating stage corresponding to the target value until the target value is reduced.

3. The method for controlling an electronic expansion valve of an outdoor unit of a multi-connected unit according to claim 1, wherein: in step S4, after the adjustment is completed, the current opening size and the on/off demand are continued for the rated interval time, and then the cyclic operation steps S2 and S3 are repeated.

4. The method for controlling an electronic expansion valve of an outdoor unit of a multi-connected unit according to claim 3, wherein: the interval time is 2 min.

5. The method for controlling an electronic expansion valve of an outdoor unit of a multi-connected unit according to claim 1, wherein: when the air conditioning system is just powered on and started, the electronic expansion valve of the outdoor unit is adjusted to a rated initial opening degree and the electromagnetic valve is opened, and after the air conditioning system is continuously operated for a rated initial time, operation steps S1 to S4 are carried out to adjust the opening degree of the electronic expansion valve and the opening/closing requirement of the electromagnetic valve.

6. The method for controlling an electronic expansion valve of an outdoor unit of a multi-connected unit according to claim 5, wherein: the initial time is 2 min.

7. The method for controlling an electronic expansion valve of an outdoor unit of a multi-connected unit according to claim 5, wherein: the initial opening degree is the maximum opening degree of the electronic expansion valve.

8. The method for controlling an electronic expansion valve of an outdoor unit of a multi-connected unit according to claim 7, wherein: the maximum opening degree of the electronic expansion valve is 480P.

9. The method for controlling an electronic expansion valve of an outdoor unit of a multi-connected unit according to claim 1, wherein: the exhaust temperature adjusting stage is provided with sixteen stages, the opening degree of the electronic expansion valve corresponding to each exhaust temperature adjusting stage is increased step by step in sequence, and the exhaust temperature adjusting stage at the highest stage corresponds to the maximum opening degree of the electronic expansion valve and opens the electromagnetic valve.

10. The method for controlling an electronic expansion valve of an outdoor unit of a multi-connected unit according to claim 1, wherein: the exhaust pressure regulating stage is provided with six stages, the opening degree of the electronic expansion valve corresponding to each stage of exhaust pressure regulating stage is increased step by step in sequence, and the exhaust pressure regulating stage at the highest stage corresponds to the maximum opening degree of the electronic expansion valve.

Technical Field

The invention relates to the technical field of air conditioning systems, in particular to a control method for an electronic expansion valve of a multi-connected outdoor unit.

Background

In the existing multi-split air conditioning system, an electronic expansion valve of an outdoor unit of a Japanese enterprise represented by Japan is connected with a one-way valve in parallel, when the outdoor unit is used for refrigerating, the one-way valve is directly conducted, the caliber of the one-way valve is large, most of refrigerants pass through the one-way valve, and the opening and the closing of the electronic expansion valve have no influence on the refrigerant passing through the one-way valve, so that the electronic expansion valve of the outdoor unit is not used for throttling and reducing pressure in a refrigerating mode, a control method is not required to be added, the electronic expansion valve is directly opened to the maximum opening, and the electronic expansion valve of the indoor unit is.

However, there are some manufacturers in China, the throttle component of the outdoor unit of the multi-split air conditioner is formed by connecting an electronic expansion valve and a one-way valve in parallel, but a solenoid valve structure is connected in series in front of the one-way valve, as follows, in the refrigeration mode, the throttle component of the outdoor unit needs to bear the functions of saving energy and reducing pressure, the solenoid valve is opened according to the needs, and the opening and the closing of the electronic expansion valve have absolute influence on the refrigerant passing through the whole throttle component, so the electronic expansion valve of the throttle component structure of the outdoor unit is generally controlled in the refrigeration mode, and the control method is different among manufacturers and is generally controlled according to the exhaust temperature of the compressor or the exhaust superheat degree of the compressor.

The method has a problem that the electronic expansion valve is opened relatively when the exhaust temperature is high and closed relatively when the exhaust temperature is low due to too much refrigerant in the system, but the pressure is relatively high, so that the electronic expansion valve is opened relatively little, particularly in extreme conditions, the electronic expansion valve is closed relatively little, and the pressure is high vicious circle due to the small opening and the high system pressure in the conventional electronic expansion valve.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provide a control method of an electronic expansion valve of a multi-connected outdoor unit, which not only ensures the accurate adjustment of the refrigerant flow of an air conditioning system and the reliable operation of the system, but also ensures the small vibration, no noise and good reliability of the electronic expansion valve according to the characteristics of the electronic expansion valve.

In order to achieve the purpose, the invention provides a control method of an electronic expansion valve of a multi-connected outdoor unit, wherein the outdoor unit is provided with a throttling component, the throttling component comprises the electronic expansion valve, a one-way valve and an electromagnetic valve, the electromagnetic valve is connected with the one-way valve in series and then connected with the electronic expansion valve in parallel, and a multi-stage exhaust temperature regulation stage and a multi-stage exhaust pressure regulation stage are preset and divided, wherein each stage of the exhaust temperature regulation stage or the exhaust pressure regulation stage is provided with the opening size of the electronic expansion valve and the on/off requirement of the electromagnetic valve;

the control method of the throttling component comprises the following specific steps:

s1, monitoring and obtaining the current exhaust temperature Tt and the current exhaust pressure Tp of a compressor in the running process of an outdoor unit in a refrigeration mode of an air conditioning system;

s2, determining a corresponding exhaust temperature regulation stage and an exhaust pressure regulation stage based on the current exhaust temperature Tt and the exhaust pressure Tp, and determining the opening size of an electronic expansion valve and the on/off requirement of an electromagnetic valve respectively corresponding to the exhaust temperature regulation stage and the exhaust pressure regulation stage;

s3, comparing the opening degree of the electronic expansion valve corresponding to the exhaust temperature Tt and the exhaust pressure Tp to determine the maximum opening degree between the exhaust temperature Tt and the exhaust pressure Tp as a target value, so as to control the electronic expansion valve to be adjusted to the target value from the current opening degree; meanwhile, whether at least one opening requirement exists between the exhaust temperature Tt and the electromagnetic valve opening/closing requirement corresponding to the exhaust pressure Tp is determined, wherein if at least one opening requirement exists, the electromagnetic valve is controlled to be opened; on the contrary, if at least one opening requirement does not exist, the electromagnetic valve is controlled to be closed;

and S4, after the adjustment is finished, repeating the steps S2 and S3 in a circulating mode until the air conditioning system is closed.

Further, in step S3, comparing the determined target value with the current opening degree of the electronic expansion valve, wherein if the target value is larger than the current opening degree, controlling the opening degree of the electronic expansion valve to be directly adjusted up to the target value; otherwise, if the target value is smaller than the current opening, the electronic expansion valve is controlled to be gradually reduced from the current opening according to the exhaust temperature regulating stage or the multi-stage exhaust pressure regulating stage corresponding to the target value until the target value is reduced.

Further, in step S4, after the adjustment is completed, the operation is repeated in steps S2 and S3 in a cycle after the current opening degree and the on/off demand are continued for the rated interval time.

Further, the interval time is 2 min.

Further, when the air conditioning system is just powered on and started, the electronic expansion valve of the outdoor unit is adjusted to a rated initial opening degree and the electromagnetic valve is opened, and after the air conditioning system is continuously operated for a rated initial time, the operation steps S1 to S4 are performed to adjust the opening degree of the electronic expansion valve and the on/off demand of the electromagnetic valve.

Further, the initial time is 2 min.

Further, the initial opening degree is the maximum opening degree of the electronic expansion valve.

Further, the maximum opening degree of the electronic expansion valve is 480P.

Furthermore, the exhaust temperature adjusting stage is provided with sixteen stages, the opening degree of the electronic expansion valve corresponding to each exhaust temperature adjusting stage is increased step by step in sequence, and the exhaust temperature adjusting stage at the highest stage corresponds to the maximum opening degree of the electronic expansion valve and opens the electromagnetic valve.

Furthermore, the exhaust pressure regulating stage is provided with six stages, the opening degree of the electronic expansion valve corresponding to each stage of exhaust pressure regulating stage is increased step by step in sequence, and the exhaust pressure regulating stage at the highest stage corresponds to the maximum opening degree of the electronic expansion valve.

The invention adopts the scheme, and has the beneficial effects that: 1) compared with the existing method of controlling only according to a certain variable, the method has the advantages that the regulation is more accurate, the exhaust temperature of the system can be controlled within a reasonable range, and the exhaust pressure can be controlled within a reasonable range; 2) the problem of in the air conditioning system because refrigerant volume is too much, the exhaust is not high, and the aperture of electronic expansion valve is more reasonable when pressure is too high is solved, reduced electronic expansion valve's vibration and noise, provided electronic expansion valve's reliability and user's comfortable nature experience.

Drawings

Fig. 1 is a flow chart illustrating a method for controlling an electronic expansion valve according to the present invention.

Fig. 2 is a schematic structural view of the throttling part of the present invention.

Fig. 3 is a schematic diagram of an exhaust temperature regulation stage of the present invention.

FIG. 4 is a schematic diagram of an exhaust pressure regulation stage of the present invention.

Detailed Description

To facilitate an understanding of the invention, the invention is described more fully below with reference to the accompanying drawings. Preferred embodiments of the present invention are shown in the drawings. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. These embodiments are provided so that this disclosure will be thorough and complete. It should be noted that the terms "first" and "second" in the present invention do not denote any particular quantity or order, but rather are used for distinguishing names.

Referring to fig. 1 and 2, in this embodiment, the outdoor unit is provided with a throttling component, wherein the throttling component includes an electronic expansion valve, a one-way valve and a solenoid valve, and the solenoid valve is connected in series with the one-way valve and then connected in parallel with the electronic expansion valve.

In order to achieve a precise control of the throttling element, the control method is explained further below.

In this embodiment, a plurality of stages of exhaust temperature regulation stages and a plurality of stages of exhaust pressure regulation stages are preset in a divided manner, where each stage of exhaust temperature regulation stage or each stage of exhaust pressure regulation stage is provided with an opening size of the corresponding electronic expansion valve and an on/off demand of the electromagnetic valve, that is, in this embodiment, sixteen stages of exhaust temperature regulation stages are set according to the exhaust temperature division, the opening of the electronic expansion valve corresponding to each stage of exhaust temperature regulation stage increases step by step in sequence, and the exhaust temperature regulation stage at the highest stage corresponds to the maximum opening of the electronic expansion valve and opens the electromagnetic valve, as shown in fig. 3:

the first stage is that the exhaust temperature is less than 51 ℃, the opening degree of a corresponding electronic expansion valve is 104P, and an electromagnetic valve is closed;

the second stage is that the exhaust temperature is more than 51 and less than 55 ℃, the opening degree of a corresponding electronic expansion valve is 120P, and the electromagnetic valve is closed;

the third stage is that the exhaust temperature is more than 51 and less than 59 ℃, the opening degree of a corresponding electronic expansion valve is 136P, and the electromagnetic valve is closed;

the fourth stage is that the exhaust temperature is more than 59 ℃ and less than 63 ℃, the opening degree of a corresponding electronic expansion valve is 160P, and the electromagnetic valve is closed;

the fifth stage is that the exhaust temperature is more than 63 and less than 68 ℃, the opening degree of a corresponding electronic expansion valve is 200P, and the electromagnetic valve is closed;

the sixth stage is that the exhaust temperature is more than 68 and less than 72 ℃, the opening degree of a corresponding electronic expansion valve is 240P, and the electromagnetic valve is closed;

the seventh stage is that the exhaust temperature is more than 72 ℃ and less than 76 ℃, the opening degree of a corresponding electronic expansion valve is 280P, and the electromagnetic valve is closed;

the eighth stage is that the exhaust temperature is more than 76 and less than 80 ℃, the opening degree of a corresponding electronic expansion valve is 320P, and the electromagnetic valve is closed;

the ninth stage is that the exhaust temperature is more than 80 and less than 83 ℃, the opening degree of a corresponding electronic expansion valve is 360P, and the electromagnetic valve is closed;

the tenth stage is that the exhaust temperature is more than 83 ℃ and less than 86 ℃, the opening degree of a corresponding electronic expansion valve is 400P, and the electromagnetic valve is closed;

the eleventh stage is that the exhaust temperature is more than 86 and less than 89 ℃, the opening degree of a corresponding electronic expansion valve is 448P, and the electromagnetic valve is closed;

the exhaust temperature of the twelfth stage is more than 89 ℃ and less than 92 ℃, the opening degree of the corresponding electronic expansion valve is 456P, and the electromagnetic valve is closed;

the exhaust temperature is more than 92 and less than 95 ℃ in the thirteenth stage, the opening degree of a corresponding electronic expansion valve is 480P, and the electromagnetic valve is closed;

the exhaust temperature of the fourth stage is more than 95 and less than 98 ℃, the opening degree of the corresponding electronic expansion valve is 480P, and the electromagnetic valve is closed;

the fifteenth level is that the exhaust temperature is more than 95 and less than 98 ℃, the opening degree of a corresponding electronic expansion valve is 480P, and the electromagnetic valve is closed;

the sixteenth grade is that the exhaust temperature is more than 100 ℃, the opening degree of the corresponding electronic expansion valve is 480P, and the electromagnetic valve is opened.

In this embodiment, six stages of exhaust pressure regulation stages are divided according to the exhaust pressure, the opening degree of the electronic expansion valve corresponding to each stage of exhaust pressure regulation stage increases step by step in sequence, and the exhaust pressure regulation stage at the highest stage corresponds to the maximum opening degree of the electronic expansion valve, as shown in fig. 4:

the first stage is that the exhaust pressure is less than 3.4MPa, the opening of the corresponding electronic expansion valve is the minimum opening, and the electromagnetic valve is closed;

the second stage is that the exhaust pressure is more than 3.4MPa and less than 3.5MPa, the opening of a corresponding electronic expansion valve is 280P, and the electromagnetic valve is closed;

the third stage is that the exhaust pressure is more than 3.5MPa and less than 3.6MPa, the opening degree of a corresponding electronic expansion valve is 320P, and the electromagnetic valve is closed;

the fourth stage is that the exhaust pressure is more than 3.6MPa and less than 3.7MPa, the opening degree of a corresponding electronic expansion valve is 360P, and the electromagnetic valve is closed;

the fifth stage is that the exhaust pressure is more than 3.7MPa and less than 3.8MPa, the opening degree of a corresponding electronic expansion valve is 400P, and the electromagnetic valve is closed;

the sixth stage is that the exhaust pressure is less than 3.8MPa, the opening degree of the corresponding electronic expansion valve is 480P, and the electromagnetic valve is closed.

In this embodiment, the control method of the throttling component is specifically as follows:

s1, monitoring and obtaining the current discharge temperature Tt and the current discharge pressure Tp of the compressor in the running process of the outdoor unit in the refrigeration mode of the air conditioning system.

S2, determining a corresponding exhaust temperature regulation stage and an exhaust pressure regulation stage based on the current exhaust temperature Tt and the exhaust pressure Tp, and determining the opening size of an electronic expansion valve and the on/off requirement of an electromagnetic valve respectively corresponding to the exhaust temperature regulation stage and the exhaust pressure regulation stage; here, for ease of understanding, the description is made specifically in conjunction with the specific exhaust temperature Tt and exhaust pressure Tp: if the monitored exhaust temperature Tt is 74 ℃ and the monitored exhaust pressure Tp is 3.65MPa, the monitored exhaust temperature Tt corresponds to a seventh-stage exhaust temperature regulating stage and a fourth-stage exhaust pressure regulating stage respectively, the opening degrees of electronic expansion valves correspond to 280P and 360P respectively, and the electromagnetic valves are closed.

And S3, comparing the opening degree of the electronic expansion valve corresponding to the exhaust temperature Tt and the exhaust pressure Tp to determine the maximum opening degree between the exhaust temperature Tt and the exhaust pressure Tp as a target value, so as to control the electronic expansion valve to be adjusted to the target value from the current opening degree, namely, comparing the size of the electronic expansion valve to determine the opening degree 360P corresponding to the exhaust pressure Tp as the target value, so as to control the opening degree of the electronic expansion valve to be adjusted to the target value. Meanwhile, whether at least one opening requirement exists between the exhaust temperature Tt and the electromagnetic valve opening/closing requirement corresponding to the exhaust pressure Tp is determined, wherein if at least one opening requirement exists, the electromagnetic valve is controlled to be opened; on the contrary, if at least one opening requirement does not exist, the electromagnetic valve is controlled to be closed, namely, the electromagnetic valves are all closed.

And S4, after the adjustment is finished, repeating the steps S2 and S3 in a circulating mode until the air conditioning system is closed.

Through comparing and determining the opening of the electronic expansion valve corresponding to the exhaust temperature Tt and the exhaust pressure Tp and the on/off requirements of the electronic expansion valve in the step S3, the inaccuracy of the traditional single variable control is solved, the method has the characteristic of higher accuracy, and the method can ensure that the exhaust temperature of the system is controlled within a reasonable range and the exhaust pressure is controlled within a reasonable range.

In the present embodiment, in step S3, the determined target value is compared with the current opening degree of the electronic expansion valve, wherein if the target value is greater than the current opening degree, the opening degree of the electronic expansion valve is controlled to be directly adjusted up to the target value; otherwise, if the target value is smaller than the current opening, the electronic expansion valve is controlled to be gradually reduced from the current opening according to the exhaust temperature regulating stage or the multi-stage exhaust pressure regulating stage corresponding to the target value until the target value is reduced. That is, if the target value is 360P and the current opening degree is 300P, the electronic expansion valve is directly adjusted from 300P to 360P; otherwise, if the target value is 360P and the current opening is 480P, the electronic expansion valve is gradually adjusted from 480P to 360P, and the process of gradual adjustment is performed.

In this embodiment, in step S4, after the adjustment is completed, the current opening size and the on/off requirement are continued for the rated interval time, and then the steps S2 and S3 are repeated in a cycle, that is, the interval time is 2min, so that the air conditioning system has an adaptive operation process after the adjustment, and the whole adjustment process is more reasonable.

In this embodiment, when the air conditioning system is just powered on and started, the electronic expansion valve of the outdoor unit is adjusted to a rated initial opening degree and the electromagnetic valve is opened, and after the air conditioning system is continuously operated for a rated initial time, operation steps S1 to S4 are performed to adjust the opening degree of the electronic expansion valve and the on/off demand of the electromagnetic valve, where the initial opening degree of this embodiment is 480P (the initial opening degree is the maximum opening degree of the electronic expansion valve), and the initial time is 2min, so that the air conditioning system is convenient to perform throttling control after entering a normal and steady operation state after passing through an adaptive initial operation stage, and is more accurate and reliable.

The above-described embodiments are merely preferred embodiments of the present invention, which is not intended to limit the present invention in any way. Those skilled in the art can make many changes, modifications, and equivalents to the embodiments of the invention without departing from the scope of the invention as set forth in the claims below. Therefore, equivalent changes made according to the spirit of the present invention should be covered within the protection scope of the present invention without departing from the contents of the technical scheme of the present invention.