WO2022105469A1

WO2022105469A1 - Oil return control method and apparatus for air conditioning system, and air conditioning system

Info

Publication number: WO2022105469A1
Application number: PCT/CN2021/122790
Authority: WO
Inventors: 周永祥; 金孟孟; 申传涛; 李华杰; 王帆
Original assignee: 珠海格力电器股份有限公司
Priority date: 2020-11-19
Filing date: 2021-10-09
Publication date: 2022-05-27
Also published as: CN112432387B; CN112432387A

Abstract

Disclosed in the present disclosure are an oil return control method and apparatus for an air conditioning system, and the air conditioning system. The method comprises: once a compressor of the air conditioning system starts up and operates accumulatively for a first set duration, acquiring operating parameters of the air conditioning system; and according to the operating parameters, determining whether a first switch unit and a second switch unit are normal, so that the air conditioning system is controlled to operate normally and return oil normally when the first switch unit and/or the second switch unit are normal, and when the first switch unit and the second switch unit are abnormal, the air conditioning system is controlled to shut down for oil return protection. In the solution, when an oil return solenoid valve of the air conditioning system fails, the air conditioning system may continue to operate normally or take protective measures to avoid the failure of the air conditioning system.

Description

Oil return control method, device and air conditioning system of an air conditioning system

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is based on the CN application number 202011301430.9 and the filing date is Nov. 19, 2020, and claims its priority. The disclosure of the CN application is hereby incorporated into the present application as a whole.

technical field

The present disclosure belongs to the technical field of air conditioning systems, and in particular relates to an oil return control method and device for an air conditioning system, and an air conditioning system.

Background technique

In the oil return control of the air conditioning system, there is no control to judge whether the oil return solenoid valve is working normally. In actual use, if the oil return control is continued when the oil return solenoid valve fails, the oil return will be abnormal, which will directly lead to the dry operation of the compressor, accelerate the wear of the compressor, and cause failure.

The above content is only used to assist the understanding of the technical solutions of the present disclosure, and does not represent an admission that the above content is the prior art.

SUMMARY OF THE INVENTION

The present disclosure provides an oil return control method for an air conditioning system. The air conditioning system includes: a first oil return pipeline and a second oil return pipeline; a first switch unit is provided on the first oil return pipeline, and the A second switch unit is provided on the second oil return pipeline; the oil return control method of the air conditioning system includes: after the compressor of the air conditioning system starts and runs for a first set period of time accumulatively, obtaining the data of the air conditioning system. Operating parameters; according to the operating parameters, determine whether the first switch unit and the second switch unit are normal, so as to control the air conditioning system when the first switch unit and/or the second switch unit are normal Normal operation and normal oil return, when the first switch unit and the second switch unit are abnormal, the air-conditioning system is controlled to be shut down for oil return protection.

In some embodiments, the operating parameters include: the first oil return temperature of the first oil return line, the second oil return temperature of the second oil return line, and the operation of the compressor of the air conditioning system frequency and exhaust temperature, as well as the outside ambient temperature of the air conditioning system.

In some embodiments, a first temperature detection unit is provided on the first oil return line, and a second temperature detection unit is provided on the second oil return line; the first oil return temperature in the operating parameters is obtained . The second oil return temperature includes: acquiring the first oil return temperature detected by the first temperature detection unit, and acquiring the second oil return temperature detected by the second temperature detection unit.

In some embodiments, determining whether the first switch unit and the second switch unit are normal according to the operating parameters includes: if the operating frequency of the compressor is less than or equal to a set frequency, determining the Whether the absolute value of the first temperature difference between the first return oil temperature and the outdoor ambient temperature is greater than or equal to the first set temperature, and determine the second temperature difference between the first return oil temperature and the exhaust gas temperature Whether the absolute value is less than or equal to the second set temperature; if the absolute value of the first temperature difference between the first return oil temperature and the outdoor ambient temperature is greater than or equal to the first set temperature, and the first return oil temperature If the absolute value of the second temperature difference between the temperature and the exhaust gas temperature is less than or equal to the second set temperature, it is determined that the first switch unit is normal, so as to control the first oil return line to return oil; if the The absolute value of the first temperature difference between the first return oil temperature and the outdoor ambient temperature is smaller than the first set temperature, or the absolute value of the second temperature difference between the first return oil temperature and the exhaust temperature is greater than the first temperature difference. If the second temperature is set, it is further determined whether the first switch unit and the second switch unit are normal according to the first oil return temperature and the second oil return temperature.

In some embodiments, further determining whether the first switch unit and the second switch unit are normal according to the first oil return temperature and the second oil return temperature includes: determining the first oil return Whether the absolute value of the third temperature difference between the temperature and the second oil return temperature is greater than or equal to the third set temperature; if the absolute value of the third temperature difference between the first oil return temperature and the second oil return temperature If the value is greater than or equal to the third set temperature, it is determined that the first switch unit is normal, so as to control the first oil return line to return oil; if the difference between the first oil return temperature and the second oil return temperature The absolute value of the third temperature difference between the two is less than the third set temperature, then it is determined that the first switch unit is abnormal, and the second switch unit is controlled to be turned on; and, after the second set time period, if the second time If the absolute value of the fourth temperature difference between the oil temperature and the outdoor ambient temperature is less than or equal to the first set temperature, the air conditioning system is controlled to report the oil return protection shutdown fault; if the second oil return temperature is different from the outdoor temperature If the absolute value of the fourth temperature difference between the ambient temperatures is greater than the first set temperature, the air-conditioning system is controlled to exit the oil return control process and operate normally; wherein the oil return protection shutdown fault has a limited number of recovery times.

In some embodiments, determining whether the first switch unit and the second switch unit are normal according to the operating parameters, further comprising: if the operating frequency of the compressor is greater than a set frequency, determining the first switch unit and the second switch unit. Whether the absolute value of the third temperature difference between the first oil return temperature and the second oil return temperature is less than the third set temperature; if the third temperature difference between the first return oil temperature and the second oil return temperature If the absolute value is less than the third set temperature, then according to the first oil return temperature and the exhaust gas temperature, it is further determined whether the first switch unit and the second switch unit are normal; if the first oil return temperature If the absolute value of the third temperature difference between the temperature and the second oil return temperature is greater than the third set temperature, it is further determined according to the first oil return temperature, the second oil return temperature and the exhaust gas temperature Whether the first switch unit and the second switch unit are normal.

In some embodiments, further determining whether the first switch unit and the second switch unit are normal according to the first oil return temperature and the exhaust gas temperature includes: determining the first oil return temperature and the temperature of the exhaust gas. Whether the absolute value of the second temperature difference between the exhaust temperatures is less than or equal to the second set temperature; if the absolute value of the second temperature difference between the first return oil temperature and the exhaust temperature is less than or equal to the second If the absolute value of the second temperature difference between the first oil return temperature and the exhaust gas temperature is greater than the second set temperature, the When the absolute value of the first temperature difference between the first oil return temperature and the outdoor ambient temperature is greater than or equal to the fourth set temperature, control the air conditioning system to exit the oil return control process and operate normally; When the absolute value of the first temperature difference between the oil return temperature and the outdoor ambient temperature is less than the fourth set temperature, the air conditioning system is controlled to report a shutdown fault for oil return protection.

In some embodiments, further determining whether the first switch unit and the second switch unit are normal according to the first oil return temperature, the second oil return temperature and the exhaust gas temperature includes: determining Whether the absolute value of the fifth temperature difference between the smaller of the first oil return temperature and the second oil return temperature and the exhaust gas temperature is greater than the second set temperature; if the first oil return temperature If the absolute value of the fifth temperature difference between the smaller of the second oil return temperature and the exhaust gas temperature is greater than the second set temperature, then at the first oil return temperature and the second oil return temperature When the absolute value of the sixth temperature difference between the smaller of the temperatures and the outdoor ambient temperature is greater than or equal to the fourth set temperature, the air-conditioning system is controlled to exit the oil return control process and operate normally; in the first In the case where the absolute value of the sixth temperature difference between the smaller of the oil return temperature and the second oil return temperature and the outdoor ambient temperature is less than the fourth set temperature, the operating frequency of executing the compressor is less than or The process of determining whether the first switch unit and the second switch unit are normal when the frequency is equal to the set frequency; If the absolute value of the fifth temperature difference between the air temperatures is less than or equal to the second set temperature, the air conditioning system is controlled to exit the oil return control process and operate normally.

Matching with the above-mentioned device, another aspect of the present disclosure provides an air-conditioning system, comprising: the above-mentioned oil return control device of the air-conditioning system.

Matching with the oil return control method of the above air conditioning system, another aspect of the present disclosure provides an oil return control device for an air conditioning system, the air conditioning system includes: a first oil return pipeline and a second oil return pipeline; The first oil return pipeline is provided with a first switch unit, and the second oil return pipeline is provided with a second switch unit; the oil return control device of the air conditioning system includes: an acquisition unit and a control unit; wherein the The obtaining unit is configured to obtain the operation parameters of the air-conditioning system after the compressor of the air-conditioning system starts and runs for a first set period of time accumulatively; the control unit is configured to obtain the operation parameters of the air-conditioning system according to the obtained operation parameters, to determine whether the first switch unit and the second switch unit are normal, so as to control the normal operation and normal oil return of the air conditioning system when the first switch unit and/or the second switch unit are normal, When the first switch unit and the second switch unit are abnormal, the oil return protection of the air conditioning system is controlled to stop.

In some embodiments, a first temperature detection unit is provided on the first oil return pipeline, and a second temperature detection unit is provided on the second oil return pipeline; the acquisition unit acquires a first temperature detection unit in the operating parameters The oil return temperature and the second oil return temperature include: acquiring the first oil return temperature detected by the first temperature detection unit, and acquiring the second oil return temperature detected by the second temperature detection unit.

In some embodiments, in the air conditioning system, on the first oil return line, between the first temperature detection unit and the first switch unit, a first throttle unit is further provided; On the second oil return pipeline, a second throttle unit is further arranged between the second temperature detection unit and the second switch unit.

In some embodiments, the control unit, according to the operating parameter, determines whether the first switch unit and the second switch unit are normal, including: if the operating frequency of the compressor is less than or equal to a set frequency , then determine whether the absolute value of the first temperature difference between the first return oil temperature and the outdoor ambient temperature is greater than or equal to the first set temperature, and determine whether the first return oil temperature and the exhaust temperature Whether the absolute value of the second temperature difference between the two is less than or equal to the second set temperature; if the absolute value of the first temperature difference between the first return oil temperature and the outdoor ambient temperature is greater than or equal to the first set temperature, and all If the absolute value of the second temperature difference between the first oil return temperature and the exhaust gas temperature is less than or equal to the second set temperature, it is determined that the first switch unit is normal, so as to control the first oil return line to return oil; if the absolute value of the first temperature difference between the first oil return temperature and the outdoor ambient temperature is less than the first set temperature, or the second temperature difference between the first return oil temperature and the exhaust gas temperature If the absolute value of the temperature difference is greater than the second set temperature, it is further determined whether the first switch unit and the second switch unit are normal according to the first oil return temperature and the second oil return temperature.

In some embodiments, the control unit, according to the first oil return temperature and the second oil return temperature, further determine whether the first switch unit and the second switch unit are normal, including: determining the Whether the absolute value of the third temperature difference between the first oil return temperature and the second oil return temperature is greater than or equal to the third set temperature; if the difference between the first oil return temperature and the second oil return temperature The absolute value of the third temperature difference is greater than or equal to the third set temperature, then it is determined that the first switch unit is normal, so as to control the first oil return pipeline to return oil; The absolute value of the third temperature difference between the secondary return oil temperatures is less than the third set temperature, it is determined that the first switch unit is abnormal, and the second switch unit is controlled to be turned on; and, after the second set time period, if If the absolute value of the fourth temperature difference between the second oil return temperature and the outdoor ambient temperature is less than or equal to the first set temperature, the air conditioning system is controlled to report the oil return protection shutdown fault; if the second oil return If the absolute value of the fourth temperature difference between the temperature and the outdoor ambient temperature is greater than the first set temperature, the air conditioning system is controlled to exit the oil return control process and operate normally; wherein the oil return protection shutdown fault has a limited number of recovery times.

In some embodiments, the control unit, according to the operating parameters, determines whether the first switch unit and the second switch unit are normal, and further includes: if the operating frequency of the compressor is greater than a set frequency, Then determine whether the absolute value of the third temperature difference between the first oil return temperature and the second oil return temperature is less than the third set temperature; if the difference between the first oil return temperature and the second oil return temperature The absolute value of the third temperature difference between the two is less than the third set temperature, then according to the first oil return temperature and the exhaust temperature, it is further determined whether the first switch unit and the second switch unit are normal; If the absolute value of the third temperature difference between the first oil return temperature and the second oil return temperature is greater than the third set temperature, then according to the first oil return temperature, the second oil return temperature and the discharge air temperature, and further determine whether the first switch unit and the second switch unit are normal.

In some embodiments, the control unit, according to the first oil return temperature and the exhaust gas temperature, further determine whether the first switch unit and the second switch unit are normal, including: determining the first switch unit Whether the absolute value of the second temperature difference between the first return oil temperature and the exhaust temperature is less than or equal to the second set temperature; if the absolute value of the second temperature difference between the first return oil temperature and the exhaust temperature is less than or equal to the second set temperature, control the air conditioning system to exit the oil return control process and operate normally; if the absolute value of the second temperature difference between the first return oil temperature and the exhaust temperature is greater than the second set temperature If the absolute value of the first temperature difference between the first oil return temperature and the outdoor ambient temperature is greater than or equal to the fourth set temperature, control the air conditioning system to exit the oil return control process and operate normally; When the absolute value of the first temperature difference between the first oil return temperature and the outdoor ambient temperature is smaller than the fourth set temperature, the air conditioning system is controlled to report an oil return protection shutdown fault.

In some embodiments, the control unit further determines whether the first switch unit and the second switch unit are based on the first oil return temperature, the second oil return temperature and the exhaust gas temperature Normal, including: determining whether the absolute value of the fifth temperature difference between the smaller of the first oil return temperature and the second oil return temperature and the exhaust gas temperature is greater than the second set temperature; if the The absolute value of the fifth temperature difference between the smaller of the first oil return temperature and the second oil return temperature and the exhaust gas temperature is greater than the second set temperature, then the first oil return temperature and the When the absolute value of the sixth temperature difference between the smaller of the second oil return temperatures and the outdoor ambient temperature is greater than or equal to the fourth set temperature, control the air conditioning system to exit the oil return control process and operate normally; The compressor is executed when the sixth absolute value of the temperature difference between the smaller of the first oil return temperature and the second oil return temperature and the outdoor ambient temperature is smaller than a fourth set temperature The process of determining whether the first switch unit and the second switch unit are normal when the operating frequency is less than or equal to the set frequency; If the absolute value of the fifth temperature difference between the first temperature and the exhaust gas temperature is less than or equal to the second set temperature, the air conditioning system is controlled to exit the oil return control process and operate normally.

Other features and advantages of the present disclosure will be set forth in the description that follows, and in part will be apparent from the description, or will be learned by practice of the present disclosure.

The technical solutions of the present disclosure will be further described in detail below through the accompanying drawings and embodiments.

Description of drawings

FIG. 1 is a schematic flowchart of an embodiment of an oil return control method for an air conditioning system of the present disclosure;

2 is a schematic flowchart of an embodiment of a first control process when the operating frequency of the compressor is less than or equal to the set frequency in the method of the present disclosure;

3 is a schematic flowchart of an embodiment of further determining whether the first switch unit and the second switch unit are normal according to the first oil return temperature and the second oil return temperature in the method of the present disclosure;

4 is a schematic flowchart of an embodiment of a second control process when the operating frequency of the compressor is less than or equal to the set frequency in the method of the present disclosure;

5 is a schematic flowchart of an embodiment of further determining whether the first switch unit and the second switch unit are normal according to the first oil return temperature and the exhaust gas temperature in the method of the present disclosure;

6 is a method of further determining whether the first switch unit and the second switch unit are normal according to the first oil return temperature, the second oil return temperature and the exhaust gas temperature in the method of the present disclosure Schematic flow diagram of the embodiment;

7 is a schematic structural diagram of an embodiment of an oil return control device of an air conditioning system of the present disclosure;

8 is a schematic structural diagram of an embodiment of an air conditioning system;

9 is a schematic diagram of an oil return control flow diagram of an embodiment of an air conditioning system;

FIG. 10 is a schematic diagram of an oil return control flow of another embodiment of an air conditioning system.

Detailed ways

In order to make the purpose, technical solutions and advantages of the present disclosure clearer, the technical solutions of the present disclosure will be clearly and completely described below with reference to the specific embodiments of the present disclosure and the corresponding drawings. Obviously, the described embodiments are only some, but not all, embodiments of the present disclosure. Based on the embodiments in the present disclosure, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present disclosure.

The present disclosure provides an oil return control method, device and air conditioning system for an air conditioning system, so as to solve the problem that the oil return control of the air conditioning system will cause the failure of the oil return control when the oil return solenoid valve of the air conditioning system fails. When the oil solenoid valve fails, the air-conditioning system can continue to operate normally or take protective measures to avoid the air-conditioning system failure.

According to an embodiment of the present disclosure, an oil return control device of an air conditioning system is provided, as shown in FIG. 1 , a schematic flowchart of an embodiment of the method of the present disclosure. In the oil return control method of the air conditioning system, the air conditioning system includes: a first oil return pipeline (main oil return pipeline) arranged in parallel between the filter of the air conditioning system and the oil return port of the compressor and the second oil return line (bypass oil return line); a first switch unit (such as oil return solenoid valve 1) is provided on the first oil return line (main oil return line), and in the second oil return line The oil pipeline (bypass oil return pipeline) is provided with a second switch unit (such as oil return solenoid valve 2). The oil return control method of the air conditioning system includes steps S110 to S130.

At step S110, after the compressor of the air-conditioning system starts and runs for a first set period of time accumulatively, the operation parameters of the air-conditioning system are acquired.

The operating parameters include: the first oil return temperature of the first oil return line, the second oil return temperature of the second oil return line, the operating frequency and exhaust gas of the compressor of the air conditioning system temperature, and the outdoor ambient temperature of the air conditioning system. Step S110 may specifically be: after the compressor of the air-conditioning system starts and runs for a first set period of time (for example, 20 minutes), acquiring the first oil return temperature of the first oil return line (main oil return line) , the second oil return temperature of the second oil return line (bypass oil return line), obtain the operating frequency and exhaust temperature of the compressor of the air conditioning system, and obtain the outdoor ambient temperature of the air conditioning system.

Specifically, after the compressor of the air-conditioning system starts and runs normally for 20 minutes in total, it starts to detect the first oil return temperature t1 of the main return oil temperature sensor (ie, the oil return temperature sensor 1), and the auxiliary return oil temperature sensor (ie, the oil return temperature sensor 1). The second oil return temperature t2 of the oil return temperature sensor 2), at this time, the exhaust temperature of the compressor of the air conditioning system is Y, and the outdoor ambient temperature of the air conditioning system is T.

In some embodiments, a first temperature detection unit is provided on the first oil return line, and a second temperature detection unit is provided on the second oil return line. Specifically, in the air conditioning system, along the direction from the filter of the air conditioning system to the oil return port of the compressor of the air conditioning system, on the first oil return line (main oil return line) The front end of the first switch unit is provided with a first temperature detection unit (such as the oil return temperature bulb 1), and the front end of the second switch unit is arranged on the second oil return pipeline (bypass oil return pipeline). There is a second temperature detection unit (such as oil return temperature sensor 2).

Obtaining the first oil return temperature of the first oil return line (main oil return line) and the second oil return temperature of the second oil return line (bypass oil return line) in step S110 includes: obtaining the The first oil return temperature detected by the first temperature detection unit is obtained, and the second oil return temperature detected by the second temperature detection unit is acquired.

Specifically, a second oil return line (bypass oil return line) is added to the first oil return line (main oil return line) of the air conditioning system, and the filter of the air conditioning system and the first oil return line (main oil return line) are added. ) and the oil return solenoid valve in the second oil return line (bypass oil return line), add oil return temperature bulbs respectively. That is to say, in the oil return system of the air conditioning system, in the pipeline from the filter back to the compressor, in addition to the first oil return pipeline (main oil return pipeline), there is also a bypassed auxiliary oil return pipeline. Between the valve and the oil return solenoid valve, an oil return temperature sensor is added.

On the first oil return line (main oil return line), in the direction from the filter back to the compressor, an oil return temperature bulb 1 and an oil return solenoid valve 1 are arranged. On the auxiliary oil return pipeline, in the direction from the filter back to the compressor, a return oil temperature sensing bulb 2 and an oil return solenoid valve 2 are arranged. Through two oil return solenoid valves (ie oil return solenoid valve 1 and oil return solenoid valve 2), two oil return temperature sensors (ie oil return temperature sensor 1 and oil return temperature sensor 2), mutual judgment and mutual Therefore, it can directly participate in the shutdown fault control and frequency limit protection control of the air conditioning system through the control of the solenoid valve on the oil return pipeline.

In this way, the oil return solenoid valve and the first oil return pipe are determined by the oil return temperature detected by the oil return temperature sensor, the exhaust gas temperature detected by the exhaust temperature sensor, and the ambient temperature detected by the environmental temperature sensor. Check whether the main oil return line (main oil return line) and the second oil return line (bypass oil return line) are normal, which will help to improve the reliability of the whole machine.

At step S120, according to the operating parameters, it is determined whether the first switch unit and the second switch unit are normal, so as to control the first switch unit and/or the second switch unit when the first switch unit and/or the second switch unit are normal The air-conditioning system operates normally and returns oil normally, and when the first switch unit and the second switch unit are abnormal, the air-conditioning system is controlled to be shut down for oil return protection. That is, according to the operating frequency of the compressor, the first oil return temperature, the second oil return temperature, the exhaust gas temperature, and the outdoor ambient temperature, the first switch unit and the second Whether the second switch unit is normal, so as to control the normal operation and normal oil return of the air conditioning system when the first switch unit and/or the second switch unit are normal, and when the first switch unit and the second switch unit are normal When the unit is abnormal, the oil return protection of the air conditioning system is controlled to stop. By controlling the frequency limit protection action of the air conditioning system when the first switch unit or the second switch unit is abnormal, the stable operation of the unit is ensured.

Wherein, when both the first switch unit and the second switch unit are normal, the second switch unit such as the oil return solenoid valve 2 is closed by default when the compressor frequency is less than or equal to the set frequency XHz, and the second switch unit such as The oil return solenoid valve 2 opens when the compressor frequency > set frequency XHz.

Therefore, by comparing the oil return temperature with the ambient temperature and exhaust gas temperature, it is determined whether the oil return solenoid valve is normal. Valve control, high frequency is controlled by compressor frequency and oil return solenoid valve to improve the reliability of air conditioning system operation.

In some embodiments, the specific process of determining whether the first switch unit and the second switch unit are normal according to the operating parameters in step S120 includes: when the operating frequency of the compressor is less than or equal to a set frequency The first control process.

Therefore, the solution of the above-mentioned embodiments of the present disclosure adjusts the oil return control process by determining whether the oil return solenoid valve of the air conditioning system is normal, and enables the air conditioning system to continue to work normally or protect the compression when the oil return solenoid valve of the air conditioning system works abnormally. machine to avoid air conditioning system failure.

The following is a schematic flow chart of an embodiment of the first control process when the operating frequency of the compressor is less than or equal to the set frequency in the method of the present disclosure shown in FIG. The specific process of the first control process may include: steps S210 to S230.

Step S210, if the operating frequency of the compressor is less than or equal to the set frequency, determine whether the absolute value of the first temperature difference between the first return oil temperature and the outdoor ambient temperature is greater than or equal to the first set temperature , and determine whether the absolute value of the second temperature difference between the first oil return temperature and the exhaust gas temperature is less than or equal to the second set temperature. Among them, the operating frequency of the compressor is such as compressor frequency D, and the set frequency is XHz.

Step S220, if the absolute value of the first temperature difference between the first oil return temperature and the outdoor ambient temperature is greater than or equal to the first set temperature, and the difference between the first oil return temperature and the exhaust gas temperature The absolute value of the second temperature difference is less than or equal to the second set temperature, then it is determined that the first switch unit is normal, so as to control the first oil return line (main oil return line) to return oil.

Specifically, when compressor frequency D≤set frequency XHz, when |first oil return temperature t1-outdoor ambient temperature T|≥first set temperature a°C, and |first oil return temperature T1-exhaust temperature When Y|≤the second set temperature b°C, it is determined that the oil return solenoid valve 1 is working normally, and the normal oil return control is performed.

Step S230, if the absolute value of the first temperature difference between the first oil return temperature and the outdoor ambient temperature is less than the first set temperature, or the first temperature difference between the first oil return temperature and the exhaust gas temperature. If the absolute value of the second temperature difference is greater than the second set temperature, it is further determined whether the first switch unit and the second switch unit are normal according to the first oil return temperature and the second oil return temperature.

In some embodiments, it may be further determined whether the first switch unit and the second switch unit are based on the first oil return temperature and the second oil return temperature in combination with the method of the present disclosure shown in FIG. 3 . A schematic flowchart of a normal embodiment, further illustrating the specific process of further determining whether the first switch unit and the second switch unit are normal according to the first oil return temperature and the second oil return temperature in step S230 , which may include steps S310 to S330.

Step S310, determining whether the absolute value of the third temperature difference between the first oil return temperature and the second oil return temperature is greater than or equal to a third set temperature.

Step S320, if the absolute value of the third temperature difference between the first oil return temperature and the second oil return temperature is greater than or equal to a third set temperature, it is determined that the first switch unit is normal, so as to control the The first oil return line (main oil return line) returns oil.

Specifically, when |first oil return temperature T1-outdoor ambient temperature T|<first set temperature a°C, or |first oil return temperature T1-exhaust temperature Y|>second set temperature b°C, |The first oil return temperature T1 - the second oil return temperature T2 | ≥ the third set temperature c°C, it is determined that the oil return solenoid valve 1 is working normally, and the air conditioning system is controlled to exit the oil return control process and operate normally.

Step S330, if the absolute value of the third temperature difference between the first oil return temperature and the second oil return temperature is less than a third set temperature, determine that the first switch unit is abnormal, and control the second oil return temperature. The switch unit is turned on. And, after the second set time period, if the absolute value of the fourth temperature difference between the second oil return temperature and the outdoor ambient temperature is less than or equal to the first set temperature, the air conditioning system is controlled to return oil Protection shutdown fault; if the absolute value of the fourth temperature difference between the second oil return temperature and the outdoor ambient temperature is greater than the first set temperature, the air conditioning system is controlled to exit the oil return control process and operate normally; The number of recovery times for the oil return protection shutdown fault is limited.

Specifically, when |first oil return temperature T1-outdoor ambient temperature T|<first set temperature a°C, or |first oil return temperature T1-exhaust temperature Y|>second set temperature b°C, |The first oil return temperature T1-the second oil return temperature T2|<the third set temperature c°C. It is determined that the oil return solenoid valve 1 is abnormal, and the action "oil return solenoid valve 2 is opened" is executed. After 3 minutes, the second oil return temperature T2 is detected. If |the second oil return temperature T2-outdoor ambient temperature T| ≤ the first set temperature a°C, the air conditioning system reports the oil return protection, and the recoverable shutdown fault occurs after accumulative three times. Not recoverable. On the contrary, control the air conditioning system to exit the oil return control process and operate normally.

In some embodiments, the specific process of determining whether the first switch unit and the second switch unit are normal according to the operating parameters in step S120 further includes: when the operating frequency of the compressor is less than or equal to a set frequency the second control process.

In the following, in conjunction with the schematic flow chart of an embodiment of the second control process when the operating frequency of the compressor is less than or equal to the set frequency in the method of the present disclosure shown in FIG. The specific process of the second control process may include: steps S410 to S430.

Step S410, if the operating frequency of the compressor is greater than the set frequency, determine whether the absolute value of the third temperature difference between the first oil return temperature and the second oil return temperature is less than a third set temperature.

Step S420, if the absolute value of the third temperature difference between the first oil return temperature and the second oil return temperature is less than the third set temperature, then according to the first oil return temperature and the exhaust gas temperature, It is further determined whether the first switch unit and the second switch unit are normal.

Specifically, when the compressor frequency D>the set frequency XHz, it is determined that |the first oil return temperature T1-the second oil return temperature T2|, when |the first oil return temperature T1-the second oil return temperature T2|≤the first oil return temperature T1 When the third set temperature is c°C, compare the first return oil temperature T1-exhaust temperature Y.

In some embodiments, it may be further determined whether the first switch unit and the second switch unit are normal according to the first oil return temperature and the exhaust gas temperature in combination with the method of the present disclosure shown in FIG. 5 . A schematic flowchart of an embodiment, further illustrating the specific process of further determining whether the first switch unit and the second switch unit are normal according to the first oil return temperature and the exhaust gas temperature in step S420 may include: Steps S510 to S530.

Step S510, determining whether the absolute value of the second temperature difference between the first oil return temperature and the exhaust gas temperature is less than or equal to a second set temperature.

Step S520, if the absolute value of the second temperature difference between the first oil return temperature and the exhaust gas temperature is less than or equal to the second set temperature, the air conditioning system is controlled to exit the oil return control process and operate normally.

Specifically, when the compressor frequency D>the set frequency XHz, it is determined that |the first oil return temperature T1-the second oil return temperature T2|, when |the first oil return temperature T1-the second oil return temperature T2|≤the first oil return temperature T1 When the third set temperature is c°C, |the first oil return temperature T1-exhaust temperature Y|≤the second set temperature b°C, the air conditioning system is controlled to exit the oil return control process and operate normally.

Step S530, if the absolute value of the second temperature difference between the first oil return temperature and the exhaust gas temperature is greater than the second set temperature, then the difference between the first oil return temperature and the outdoor ambient temperature is When the absolute value of the first temperature difference is greater than or equal to the fourth set temperature, the air conditioning system is controlled to exit the oil return control process and operate normally; the first temperature difference between the first oil return temperature and the outdoor ambient temperature When the absolute value is less than the fourth set temperature, the air conditioning system is controlled to report the oil return protection shutdown fault.

Specifically, when the compressor frequency D>the set frequency XHz, it is determined that |the first oil return temperature T1-the second oil return temperature T2|, when |the first oil return temperature T1-the second oil return temperature T2|≤the first oil return temperature T1 3 When the set temperature is c°C, |the first oil return temperature T1-exhaust temperature Y|>the second set temperature b°C: if |the first oil return temperature T1-outdoor ambient temperature T|≥the fourth setting When the temperature is d°C, the air-conditioning control air-conditioning system exits the oil return control process and operates normally. Otherwise, the air-conditioning system will report the oil return protection to stop.

Step S430, if the absolute value of the third temperature difference between the first oil return temperature and the second oil return temperature is greater than the third set temperature, then according to the first oil return temperature, the second oil return temperature The temperature and the exhaust gas temperature further determine whether the first switch unit and the second switch unit are normal.

Specifically, when the compressor frequency D>the set frequency XHz, it is determined that |the first oil return temperature T1-the second oil return temperature T2|, when |the first oil return temperature T1-the second oil return temperature T2|>the first oil return temperature T1-second oil return temperature T2| When the third set temperature is c°C, compare the smaller value of the first oil return temperature T1 and the second oil return temperature T2, and compare min[first oil return temperature T1, second oil return temperature T2]-exhaust temperature Y .

In some implementations, the first switch unit and all of the first switch units and all of the above may be further determined according to the first oil return temperature, the second oil return temperature and the exhaust gas temperature in combination with the method of the present disclosure shown in FIG. 6 . A schematic flowchart of an embodiment of whether the second switch unit is normal, further illustrating that the first switch unit is further determined according to the first oil return temperature, the second oil return temperature and the exhaust temperature in step S430 The specific process of whether the second switch unit is normal may include steps S610 to S630.

Step S610, determining whether the absolute value of the fifth temperature difference between the smaller of the first oil return temperature and the second oil return temperature and the exhaust gas temperature is greater than a second set temperature.

Step S620, if the absolute value of the fifth temperature difference between the smaller of the first oil return temperature and the second oil return temperature and the exhaust gas temperature is greater than the second set temperature, then in the first When the absolute value of the sixth temperature difference between the smaller of the first return oil temperature and the second oil return temperature and the outdoor ambient temperature is greater than or equal to the fourth set temperature, the air conditioning system is controlled to exit the oil return control process, and operate normally; in the case that the absolute value of the sixth temperature difference between the smaller of the first oil return temperature and the second oil return temperature and the outdoor ambient temperature is less than the fourth set temperature and performing a process of determining whether the first switch unit and the second switch unit are normal when the operating frequency of the compressor is less than or equal to a set frequency.

Specifically, when the compressor frequency D>the set frequency XHz, it is determined that |the first oil return temperature T1-the second oil return temperature T2|, when |the first oil return temperature T1-the second oil return temperature T2|>the first oil return temperature T1-second oil return temperature T2| When the third set temperature is c°C, compare the smaller value of the first oil return temperature T1 and the second oil return temperature T2, when |min[first oil return temperature T1, second oil return temperature T2]-exhaust temperature When Y|>the second set temperature b°C: determine |min[the first oil return temperature T1, the second oil return temperature T2]-outdoor ambient temperature T| ≥ the fourth set temperature d°C, control the air conditioning system to exit the return Oil control process and run normally; otherwise, compressor frequency limit < set frequency XHz, go to step 12. min[first oil return temperature T1, second oil return temperature T2], indicating the smaller of the first oil return temperature T1 and the second oil return temperature T2.

Step S630, if the absolute value of the fifth temperature difference between the smaller of the first oil return temperature and the second oil return temperature and the exhaust gas temperature is less than or equal to the second set temperature, control the air conditioner The system exits the oil return control process and operates normally.

Specifically, when the compressor frequency D>the set frequency XHz, it is determined that |the first oil return temperature T1-the second oil return temperature T2|, when |the first oil return temperature T1-the second oil return temperature T2|>the first oil return temperature T1-second oil return temperature T2| When the third set temperature is c°C, compare the smaller value of the first oil return temperature T1 and the second oil return temperature T2, when |min[first oil return temperature T1, second oil return temperature T2]-exhaust temperature When Y|≤ second set temperature b°C, control the air conditioning system to exit the oil return control process and operate normally.

After a large number of tests and verifications, using the technical solution of this embodiment, by comparing and determining whether the oil return solenoid valve of the air conditioning system is normal, it can effectively solve the problem that when the oil return solenoid valve fails, the air conditioning system can continue to operate normally or take corresponding protection. Measures to avoid air conditioning system failure, and inform users for timely maintenance.

According to an embodiment of the present disclosure, there is also provided an oil return control device of an air conditioning system corresponding to the oil return control method of the air conditioning system. Referring to FIG. 7, a schematic structural diagram of an embodiment of the apparatus of the present disclosure is shown. In the oil return control device of the air conditioning system, the air conditioning system includes: a first oil return pipeline (main oil return pipeline) arranged in parallel between the filter of the air conditioning system and the oil return port of the compressor and the second oil return line (bypass return line). A first switch unit (such as an oil return solenoid valve 1) is arranged on the first oil return line (main oil return line), and a second oil return line (bypass oil return line) is arranged on the second oil return line (bypass oil return line). Switch unit (eg oil return solenoid valve 2). The oil return control device of the air conditioning system includes: an acquisition unit and a control unit.

Wherein, the obtaining unit is configured to obtain the operating parameters of the air-conditioning system after the compressor of the air-conditioning system starts and runs for a first set period of time accumulatively.

The operating parameters include: the first oil return temperature of the first oil return line, the second oil return temperature of the second oil return line, the operating frequency and exhaust gas of the compressor of the air conditioning system temperature, and the outdoor ambient temperature of the air conditioning system. The obtaining unit may be specifically configured to: after the compressor of the air-conditioning system starts and runs for a first set period of time (for example, 20 minutes), obtain the first oil return line (main oil return line) of the first oil return line. The first oil return temperature, the second oil return temperature of the second oil return line (bypass oil return line), obtain the operating frequency and exhaust temperature of the compressor of the air conditioning system, and obtain the outdoor air temperature of the air conditioning system ambient temperature.

In some embodiments, in the air conditioning system, along the direction from the filter of the air conditioning system to the oil return port of the compressor of the air conditioning system, in the first oil return line (main oil return line) The front end of the first switch unit is provided with a first temperature detection unit (such as the oil return temperature bulb 1), and the front end of the second switch unit on the second oil return line (bypass oil return line) A second temperature detection unit (such as the oil return temperature bulb 2) is provided.

The acquiring unit acquires the first oil return temperature of the first oil return line (main oil return line) and the second oil return temperature of the second oil return line (bypass oil return line), including: The acquisition unit is specifically configured to acquire the first oil return temperature detected by the first temperature detection unit, and acquire the second oil return temperature detected by the second temperature detection unit.

In some embodiments, a first temperature detection unit is provided on the first oil return line, and a second temperature detection unit is provided on the second oil return line. Specifically, in the air conditioning system, on the first oil return line (main oil return line), the first temperature detection unit (such as the oil return temperature bulb 1) and the first oil return line A first throttling unit (such as the oil return capillary 1 ) is also arranged between the switch units (such as the oil return solenoid valve 1 ). On the second oil return line (bypass oil return line), between the second temperature detection unit (such as the oil return temperature bulb 2) and the second switch unit (such as the oil return solenoid valve 2), A second throttling unit (such as the oil return capillary 2) is also provided.

Specifically, along the direction from the filter of the air conditioning system to the oil return port of the compressor of the air conditioning system, a first temperature detection unit (eg Oil return temperature bulb 1), the first throttling unit (such as oil return capillary 1) and the first switch unit (such as oil return solenoid valve 1), on the second oil return line (bypass oil return line) A second temperature detection unit (such as the oil return temperature bulb 2 ), a second throttle unit (such as the oil return capillary 2 ) and a second switch unit (such as the oil return solenoid valve 2 ) are provided. Through the first throttle unit and the second throttle unit, the oil return speed can be controlled.

The control unit is configured to determine whether the first switch unit and the second switch unit are normal according to the operating parameter, so that when the first switch unit and/or the second switch unit is normal Normal operation and normal oil return of the air conditioning system are controlled, and when the first switch unit and the second switch unit are abnormal, the air conditioning system is controlled to be shut down for oil return protection. That is, the control unit may be specifically configured to determine according to the operating frequency of the compressor, the first oil return temperature, the second oil return temperature, the exhaust gas temperature, and the outdoor ambient temperature. Whether the first switch unit and the second switch unit are normal, so as to control the normal operation and normal oil return of the air conditioning system when the first switch unit and/or the second switch unit are normal, and when the first switch unit and/or the second switch unit are normal When the first switch unit and the second switch unit are abnormal, the oil return protection of the air conditioning system is controlled to stop. By controlling the frequency limit protection action of the air conditioning system when the first switch unit or the second switch unit is abnormal, the stable operation of the unit is ensured.

In some embodiments, the control unit, according to the operating parameter, determines whether the first switch unit and the second switch unit are normal, including: when the operating frequency of the compressor is less than or equal to the set frequency, the A control process, the specific can be as follows:

The control unit is further configured to, if the operating frequency of the compressor is less than or equal to a set frequency, determine whether the absolute value of the first temperature difference between the first return oil temperature and the outdoor ambient temperature is greater than or equal to or equal to the first set temperature, and determine whether the absolute value of the second temperature difference between the first oil return temperature and the exhaust gas temperature is less than or equal to the second set temperature. Among them, the operating frequency of the compressor is such as compressor frequency D, and the set frequency is XHz.

The control unit is further configured to, if the absolute value of the first temperature difference between the first oil return temperature and the outdoor ambient temperature is greater than or equal to the first set temperature, and the first oil return temperature is equal to or equal to the first temperature. If the absolute value of the second temperature difference between the exhaust temperatures is less than or equal to the second set temperature, it is determined that the first switch unit is normal, so as to control the first oil return line (main oil return line) to return oil .

Specifically, when compressor frequency D≤set frequency XHz, when |first oil return temperature t1-outdoor ambient temperature T|≥first set temperature a°C, and |first oil return temperature T1-exhaust temperature When Y|≤the second set temperature b°C, it is determined that the oil return solenoid valve 1 is working normally, and the normal oil return control is executed.

The control unit is further configured to, if the absolute value of the first temperature difference between the first oil return temperature and the outdoor ambient temperature is smaller than the first set temperature, or if the first oil return temperature and the If the absolute value of the second temperature difference between the exhaust gas temperatures is greater than the second set temperature, the first switch unit and the second switch are further determined according to the first oil return temperature and the second oil return temperature unit is normal.

In some embodiments, the control unit, according to the first oil return temperature and the second oil return temperature, further determines whether the first switch unit and the second switch unit are normal, including:

The control unit is further configured to determine whether the absolute value of a third temperature difference between the first oil return temperature and the second oil return temperature is greater than or equal to a third set temperature.

The control unit is further configured to determine the first switch if the absolute value of the third temperature difference between the first oil return temperature and the second oil return temperature is greater than or equal to a third set temperature The unit is normal to control the first oil return line (main oil return line) to return oil.

The control unit is further configured to determine that the first switch unit is abnormal if the absolute value of the third temperature difference between the first oil return temperature and the second oil return temperature is smaller than a third set temperature , and control the second switch unit to turn on; and, after the second set time period, if the absolute value of the fourth temperature difference between the second oil return temperature and the outdoor ambient temperature is less than or equal to the first set If the absolute value of the fourth temperature difference between the second oil return temperature and the outdoor ambient temperature is greater than the first set temperature, the air conditioning system is controlled to exit the return Oil control process, and normal operation; wherein, the recovery times of the oil return protection shutdown fault are limited.

In some embodiments, the control unit, according to the operating parameters, determines whether the first switch unit and the second switch unit are normal, further comprising: when the operating frequency of the compressor is less than or equal to a set frequency The second control process can be specifically as follows:

The control unit is further configured to determine whether the absolute value of the third temperature difference between the first oil return temperature and the second oil return temperature is less than The third set temperature.

The control unit is further configured to, if the absolute value of the third temperature difference between the first oil return temperature and the second oil return temperature is smaller than a third set temperature, then according to the first oil return temperature With the exhaust gas temperature, it is further determined whether the first switch unit and the second switch unit are normal.

In some embodiments, the control unit, according to the first oil return temperature and the exhaust gas temperature, further determines whether the first switch unit and the second switch unit are normal, including:

The control unit is further configured to determine whether the absolute value of the second temperature difference between the first oil return temperature and the exhaust gas temperature is less than or equal to a second set temperature.

The control unit is further configured to control the air conditioning system to exit the oil return control process if the absolute value of the second temperature difference between the first oil return temperature and the exhaust gas temperature is less than or equal to a second set temperature , and it runs normally.

The control unit is further configured to, if the absolute value of the second temperature difference between the first oil return temperature and the exhaust gas temperature is greater than the second set temperature, the first oil return temperature and the When the absolute value of the first temperature difference between the outdoor ambient temperatures is greater than or equal to the fourth set temperature, the air-conditioning system is controlled to exit the oil return control process and operate normally; When the absolute value of the first temperature difference between the temperatures is less than the fourth set temperature, the air conditioning system is controlled to report an oil return protection shutdown fault.

Specifically, when the compressor frequency D>the set frequency XHz, it is determined that |the first oil return temperature T1-the second oil return temperature T2|, when |the first oil return temperature T1-the second oil return temperature T2|≤the first oil return temperature T1 3 When the set temperature is c°C, |the first oil return temperature T1-exhaust temperature Y|>the second set temperature b°C: if |the first oil return temperature T1-outdoor ambient temperature T|≥the fourth setting When the temperature is d°C, the control air-conditioning system exits the oil return control process and operates normally. Otherwise, the air-conditioning system will report the oil return protection to stop.

The control unit is further configured to, if the absolute value of the third temperature difference between the first oil return temperature and the second oil return temperature is greater than a third set temperature, according to the first oil return temperature , the second oil return temperature and the exhaust gas temperature, and further determine whether the first switch unit and the second switch unit are normal.

In some embodiments, the control unit further determines whether the first switch unit and the second switch unit are based on the first oil return temperature, the second oil return temperature and the exhaust gas temperature normal, including:

The control unit is further configured to determine whether the absolute value of the fifth temperature difference between the smaller one of the first oil return temperature and the second oil return temperature and the exhaust gas temperature is greater than the second setting. fixed temperature.

The control unit is further configured to, if the absolute value of the fifth temperature difference between the smaller of the first oil return temperature and the second oil return temperature and the exhaust gas temperature is greater than a second setting temperature, when the absolute value of the sixth temperature difference between the smaller of the first oil return temperature and the second oil return temperature and the outdoor ambient temperature is greater than or equal to the fourth set temperature, Control the air conditioning system to exit the oil return control process and operate normally; the absolute value of the sixth temperature difference between the smaller of the first oil return temperature and the second oil return temperature and the outdoor ambient temperature is less than the first In the case of four set temperatures, the process of determining whether the first switch unit and the second switch unit are normal when the operating frequency of the compressor is less than or equal to the set frequency is performed.

The control unit is further configured to, if the absolute value of the fifth temperature difference between the smaller of the first oil return temperature and the second oil return temperature and the exhaust gas temperature is less than or equal to the second Set the temperature, then control the air conditioning system to exit the oil return control process and operate normally.

Since the processing and functions implemented by the device in this embodiment basically correspond to the embodiments, principles, and examples of the foregoing methods, the description of this embodiment is not detailed, and reference may be made to the relevant descriptions in the foregoing embodiments. Do repeat.

After a large number of tests and verifications, the technical solution of the present disclosure is adopted to adjust the oil return control process by determining whether the oil return solenoid valve of the air conditioning system is normal, and when the oil return solenoid valve of the air conditioning system works abnormally, the air conditioning system can continue to work normally or not. Protect the compressor to avoid failure of the air conditioning system.

According to an embodiment of the present disclosure, an air conditioning system corresponding to an oil return control device of an air conditioning system is also provided. The air conditioning system may include: the above-mentioned oil return control device of the air conditioning system.

In the related scheme, the multi-line system (such as multi-line air conditioner) adopts the oil return control method of main oil return control and auxiliary oil return (that is, bypass oil return) control. When the compressor runs at a low frequency, only the main oil return valve is opened; When the compressor is running at high frequency, the main oil return and auxiliary oil return solenoid valves are opened at the same time. In this oil return control method, although there is auxiliary oil return control, there is no control for judging whether the oil return solenoid valve is working normally. When the oil return solenoid valve in the main oil return control and the oil return solenoid valve in the auxiliary oil return control When a certain oil return solenoid valve fails, the oil return is abnormal, which will directly lead to the dry operation of the compressor, accelerate the wear of the compressor, and cause failure.

In some embodiments, the solution of the present disclosure proposes an oil return control solution for an air conditioning system. By comparing and determining whether the oil return solenoid valve of the air conditioning system is normal to adjust the oil return control process, the oil return solenoid valve can work abnormally. At this time, the air-conditioning system can continue to work normally or protect the compressor to improve the reliability of the air-conditioning system. Therefore, it can effectively solve the problem that when the oil return solenoid valve fails, the air-conditioning system can continue to operate normally or take corresponding protective measures to avoid the failure of the air-conditioning system, and inform the user.

Specifically, in the solution of the present disclosure, a second oil return line (bypass oil return line) is added to the first oil return line (main oil return line) of the air conditioning system, and the filter of the air conditioning system and the first oil return line are connected Between the oil return solenoid valves in the main oil return line (main oil return line) and the second oil return line (bypass oil return line), add oil return temperature sensing bulbs respectively.

Through the oil return temperature detected by the oil return temperature sensor, the exhaust temperature detected by the exhaust temperature sensor, and the ambient temperature detected by the environmental temperature sensor, the oil return solenoid valve and the first oil return pipeline (main Whether the oil return line) and the second oil return line (bypass oil return line) are normal. By comparing the oil return temperature with the ambient temperature and exhaust temperature, it is determined whether the oil return solenoid valve is normal. If it is abnormal, the corresponding control will be executed to protect the system. The temperature of the return oil temperature sensor should be close to the exhaust temperature and higher than the ambient temperature.

Among them, when the oil return is abnormal, the low frequency adjusts the oil return solenoid valve control, and the high frequency controls the compressor frequency and the oil return solenoid valve control to improve the system operation reliability.

The specific implementation process of the solution of the present disclosure will be exemplarily described below with reference to the examples shown in FIG. 8 to FIG. 10 .

FIG. 8 is a schematic structural diagram of an embodiment of an air conditioning system. The solution of the present disclosure provides a control method for determining whether the oil return system is effective, so as to improve the reliability of the operation of the whole machine. As shown in Figure 8, in the oil return system of the air conditioning system, in the pipeline from the filter back to the compressor, in addition to the first oil return pipeline (main oil return pipeline), there is also a bypassed auxiliary oil return pipeline. Between the filter and the oil return solenoid valve, an oil return temperature sensor is added.

In some examples, on the first oil return line (main oil return line), in the direction from the filter back to the compressor, an oil return temperature bulb 1 and an oil return solenoid valve 1 are provided. On the auxiliary oil return pipeline, in the direction from the filter back to the compressor, a return oil temperature sensing bulb 2 and an oil return solenoid valve 2 are arranged. Through two oil return solenoid valves (ie oil return solenoid valve 1 and oil return solenoid valve 2), two oil return temperature sensors (ie oil return temperature sensor 1 and oil return temperature sensor 2), mutual judgment and mutual Therefore, it can directly participate in the shutdown fault control and frequency limit protection control of the air conditioning system through the control of the solenoid valve on the oil return pipeline.

Wherein, the oil return solenoid valve 2 is closed by default when the compressor frequency is less than or equal to the set frequency XHz, and the oil return solenoid valve 2 is opened when the compressor frequency > the set frequency XHz.

In some examples, oil return capillaries are also provided on the first oil return line (main oil return line) and the auxiliary oil return line. Specifically, on the first oil return line (main oil return line), in the direction from the filter back to the compressor, an oil return temperature bulb 1 , an oil return capillary 1 and an oil return solenoid valve 1 are provided. On the auxiliary oil return pipeline, in the direction from the filter back to the compressor, there are provided an oil return temperature sensor 2, an oil return capillary 2 and an oil return solenoid valve 2.

FIG. 9 is a schematic diagram of an oil return control flow diagram of an embodiment of an air conditioning system. As shown in Figure 9, when the air conditioning system is running, the following oil return control process is performed:

Step 11. After the compressor of the air-conditioning system starts and runs normally for 20 minutes, start to detect the first oil return temperature t1 of the main return oil temperature sensor (ie, the oil return temperature sensor 1), and the auxiliary return oil temperature sensor (ie, the oil return temperature sensor 1). The second oil return temperature t2 of the oil return temperature sensor bulb 2), at this time, the exhaust temperature of the compressor of the air conditioning system is Y, and the outdoor ambient temperature of the air conditioning system is T, and the determinations in steps 12 and 13 are performed.

Step 12. When the compressor frequency D≤the set frequency XHz, step 121 and step 122 are executed.

Step 121: When |first oil return temperature t1-outdoor ambient temperature T|≥first set temperature a°C, and |first oil return temperature T1-exhaust temperature Y|≤second set temperature b°C, It is determined that the oil return solenoid valve 1 is working normally, and the normal oil return control is performed.

Among them, the normal oil return control means that when the compressor frequency D≤X, the oil return solenoid valve 1 is opened, and the oil return solenoid valve 2 is closed; when the compressor frequency D>X, both are opened.

Step 122: When |first oil return temperature T1-outdoor ambient temperature T|<first set temperature a°C, or |first oil return temperature T1-exhaust temperature Y|>second set temperature b°C, Comparing |the first oil return temperature T1 - the second oil return temperature T2|, step 1221 and step 1222 are executed.

Step 1221: |The first oil return temperature T1-second oil return temperature T2|≥the third set temperature c°C, determine that the oil return solenoid valve 1 is working normally, control the air conditioning system to exit the oil return control process, and operate normally.

Step 1222, |The first oil return temperature T1-the second oil return temperature T2|<the third set temperature c°C. It is determined that the oil return solenoid valve 1 is abnormal, and the action "oil return solenoid valve 2 is opened" is executed. After 3 minutes, the second oil return temperature T2 is detected. If |the second oil return temperature T2-outdoor ambient temperature T| ≤ the first set temperature a°C, the air conditioning system reports the oil return protection, and the recoverable shutdown fault occurs after accumulative three times. Unrecoverable; otherwise, the air-conditioning control air-conditioning system exits the oil return control process and operates normally.

Step 13: When the compressor frequency D>the set frequency XHz, determine |the first oil return temperature T1-the second oil return temperature T2|, and execute steps 131 and 132.

Step 131: When |the first oil return temperature T1-second oil return temperature T2|≤the third set temperature c°C, step 1311 and step 1312 are executed.

Step 1311, |The first oil return temperature T1-exhaust temperature Y|≤the second set temperature b°C, control the air conditioning system to exit the oil return control process and operate normally.

Step 1312: |When the first oil return temperature T1-exhaust temperature Y|>the second set temperature b°C: if |the first oil return temperature T1-outdoor ambient temperature T|≥the fourth set temperature d°C, the air conditioner Control the air-conditioning system to exit the oil return control process and run normally; otherwise, the air-conditioning system reports oil return protection and stops.

Step 132: When |the first oil return temperature T1-second oil return temperature T2|>the third set temperature c°C, compare the smaller value of the first oil return temperature T1 and the second oil return temperature T2, and execute Step 1321 and Step 1322.

Step 1321. When |min[first oil return temperature T1, second oil return temperature T2]-exhaust temperature Y|>second set temperature b°C: determine |min[first oil return temperature T1, second Oil return temperature T2]-outdoor ambient temperature T|≥4th set temperature d°C, control the air conditioning system to exit the oil return control process and run normally; otherwise, compressor frequency limit < set frequency XHz, go to step 12. min[first oil return temperature T1, second oil return temperature T2], indicating the smaller of the first oil return temperature T1 and the second oil return temperature T2.

Step 1322: When |min[first oil return temperature T1, second oil return temperature T2]-exhaust temperature Y|≤second set temperature b°C, control the air conditioning system to exit the oil return control process and operate normally.

In the above control, the set frequency X, the first set temperature a, the second set temperature b, the third set temperature c, and the fourth set temperature d are all reasonable default set values. This is just to indicate that these values are not definite values, and can have different default settings according to different air conditioning systems (the so-called qualified is determined by different system parameters), and user settings are not required in actual use.

The following takes the multi-connection system as an example, and assigns the above-mentioned set frequency X, the first set temperature a, the second set temperature b, the third set temperature c, and the fourth set temperature d to the solution of the present disclosure. Give an example.

FIG. 10 is a schematic diagram of an oil return control flow of another embodiment of an air conditioning system. As shown in Figure 10, the oil return solenoid valve 2 is closed by default when the compressor frequency is less than or equal to 80 Hz, and is opened when the compressor frequency is greater than 80 Hz.

When the air conditioning system is running, the following oil return control procedures are performed:

Step 21. The air-conditioning system runs normally for 20 minutes, and starts to detect the first oil return temperature T1 of the main return oil temperature sensor (ie, the oil return temperature sensor 1) and the auxiliary return oil temperature sensor (ie, the oil return temperature sensor 2). The second oil return temperature T2, at this time, the exhaust temperature of the compressor of the air conditioning system is the exhaust temperature Y, and the outdoor ambient temperature of the air conditioning system is the outdoor ambient temperature T, and the determinations in steps 22 and 23 are performed.

Step 22, when the compressor frequency D≤80Hz, perform steps 221 and 222.

Step 221: When |the first oil return temperature T1-outdoor ambient temperature T|≥5℃, and |the first oil return temperature T1-exhaust temperature Y|≤10℃, determine that the oil return solenoid valve 1 is working normally, and execute Normal oil return control.

Step 2221: |The first oil return temperature T1-second oil return temperature T2|≥5°C, determine that the oil return solenoid valve 1 is working normally, and execute the normal oil return control.

Step 2222, |The first oil return temperature T1-the second oil return temperature T2|<5°C. It is determined that the oil return solenoid valve 1 is abnormal, and the action "oil return solenoid valve 2 is opened" is executed. After 3 minutes, check the second oil return temperature T2, if |second oil return temperature T2-outdoor ambient temperature T|≤5℃, the system will report the oil return protection shutdown, otherwise it will run normally.

Step 23 , when the compressor frequency D>80 Hz, determine |the first oil return temperature T1 - the second oil return temperature T2 |, and execute steps 231 and 232 .

Step 231: When |the first oil return temperature T1-second oil return temperature T2|≤5°C, step 2311 and step 2312 are performed.

Step 2311, |The first oil return temperature T1-exhaust temperature Y|≤10°C, perform normal oil return control.

Step 2312, |When the first oil return temperature T1-exhaust temperature Y|>10°C: if |the first oil return temperature T1-outdoor ambient temperature T|≥20°C, control the air conditioning system to exit the oil return control process and return to normal run; otherwise, the system reports oil return protection to stop.

Step 232: When |the first oil return temperature T1-second oil return temperature T2|>5°C, compare the smaller value of the first oil return temperature T1/second oil return temperature T2, and perform steps 2321 and 2322 .

Step 2321. When |min[first oil return temperature T1, second oil return temperature T2]-exhaust temperature Y|>10°C: determine |min[first oil return temperature T1, second oil return temperature T2] -Outdoor ambient temperature T|≥20°C, control the air-conditioning system to exit the oil return control process and operate normally; otherwise, the compressor frequency limit is less than 80Hz, and step 22 is executed.

Step 2322: When |min[first oil return temperature T1, second oil return temperature T2]-exhaust temperature Y|≤10°C, control the air conditioning system to exit the oil return control process and operate normally.

Since the processing and functions implemented by the air-conditioning system of this embodiment basically correspond to the embodiments, principles and examples of the foregoing devices, the description of this embodiment is not exhaustive, and reference may be made to the relevant descriptions in the foregoing embodiments. I won't go into details.

After a large number of tests and verifications, using the technical solution of the present disclosure, by comparing and determining whether the oil return solenoid valve of the air conditioning system is normal, to adjust the oil return control process, it can make the oil return solenoid valve work abnormally, so that the air conditioning system can continue to work normally or not. Protect the compressor and improve the reliability of the air conditioning system.

To sum up, those skilled in the art can easily understand that, on the premise that there is no conflict, the above advantageous manners can be freely combined and superimposed.

The above description is only an embodiment of the present disclosure, and is not intended to limit the present disclosure. For those skilled in the art, the present disclosure may have various modifications and changes. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present disclosure should be included within the scope of the claims of the present disclosure.

Claims

An oil return control method for an air conditioning system, characterized in that the air conditioning system comprises: a first oil return pipeline and a second oil return pipeline; a first switch unit is provided on the first oil return pipeline, and a The second oil return pipeline is provided with a second switch unit; the oil return control method of the air conditioning system includes:

After the compressor of the air-conditioning system starts and runs for a first set period of time accumulatively, acquiring the operating parameters of the air-conditioning system;

According to the operating parameters, it is determined whether the first switch unit and the second switch unit are normal, so as to control the air conditioning system to operate normally and/or when the first switch unit and/or the second switch unit are normal. Normal oil return, when the first switch unit and the second switch unit are abnormal, the air-conditioning system is controlled to be shut down for oil return protection.
The oil return control method of an air conditioning system according to claim 1, wherein the operating parameters include: a first oil return temperature of the first oil return line, a second oil return line of the second oil return line Return oil temperature, operating frequency and discharge temperature of the compressor of the air conditioning system, and outdoor ambient temperature of the air conditioning system.
The oil return control method of an air-conditioning system according to claim 2, wherein a first temperature detection unit is arranged on the first oil return pipeline, and a second temperature detection unit is arranged on the second oil return pipeline ;

Obtain the first oil return temperature and the second oil return temperature in the operating parameters, including:

The first oil return temperature detected by the first temperature detection unit is acquired, and the second oil return temperature detected by the second temperature detection unit is acquired.
The oil return control method of an air conditioning system according to claim 2 or 3, wherein determining whether the first switch unit and the second switch unit are normal according to the operating parameters, comprising:

If the operating frequency of the compressor is less than or equal to the set frequency, determine whether the absolute value of the first temperature difference between the first return oil temperature and the outdoor ambient temperature is greater than or equal to the first set temperature, and determine whether Whether the absolute value of the second temperature difference between the first oil return temperature and the exhaust gas temperature is less than or equal to the second set temperature;

If the absolute value of the first temperature difference between the first return oil temperature and the outdoor ambient temperature is greater than or equal to the first set temperature, and the second absolute value between the first return oil temperature and the exhaust gas temperature If the absolute value of the temperature difference is less than or equal to the second set temperature, it is determined that the first switch unit is normal, so as to control the first oil return pipeline to return oil;

If the absolute value of the first temperature difference between the first return oil temperature and the outdoor ambient temperature is less than the first set temperature, or the absolute value of the second temperature difference between the first return oil temperature and the exhaust gas temperature If the value is greater than the second set temperature, it is further determined whether the first switch unit and the second switch unit are normal according to the first oil return temperature and the second oil return temperature.
The oil return control method of an air conditioning system according to claim 4, wherein the first switch unit and the second switch are further determined according to the first oil return temperature and the second oil return temperature Whether the unit is normal, including:

determining whether the absolute value of a third temperature difference between the first oil return temperature and the second oil return temperature is greater than or equal to a third set temperature;

If the absolute value of the third temperature difference between the first oil return temperature and the second oil return temperature is greater than or equal to a third set temperature, it is determined that the first switch unit is normal, so as to control the first oil return temperature Return oil to the oil pipeline;

If the absolute value of the third temperature difference between the first oil return temperature and the second oil return temperature is smaller than the third set temperature, it is determined that the first switch unit is abnormal, and the second switch unit is controlled to be turned on and, after the second set time period, if the absolute value of the fourth temperature difference between the second oil return temperature and the outdoor ambient temperature is less than or equal to the first set temperature, the air-conditioning system is controlled to report back Oil protection shutdown fault; if the absolute value of the fourth temperature difference between the second oil return temperature and the outdoor ambient temperature is greater than the first set temperature, the air conditioning system is controlled to exit the oil return control process and operate normally; wherein, The number of times of recovery of the oil return protection shutdown fault is limited.
The oil return control method for an air conditioning system according to claim 2 or 3, wherein determining whether the first switch unit and the second switch unit are normal according to the operating parameters, further comprising:

If the operating frequency of the compressor is greater than the set frequency, determining whether the absolute value of the third temperature difference between the first oil return temperature and the second oil return temperature is less than a third set temperature;

If the absolute value of the third temperature difference between the first oil return temperature and the second oil return temperature is less than the third set temperature, further determine the temperature according to the first oil return temperature and the exhaust gas temperature. Whether the first switch unit and the second switch unit are normal;

If the absolute value of the third temperature difference between the first oil return temperature and the second oil return temperature is greater than the third set temperature, according to the first oil return temperature, the second oil return temperature and the and the exhaust gas temperature, and further determine whether the first switch unit and the second switch unit are normal.
The oil return control method of an air conditioning system according to claim 6, wherein whether the first switch unit and the second switch unit are further determined according to the first oil return temperature and the exhaust gas temperature normal, including:

determining whether the absolute value of the second temperature difference between the first oil return temperature and the exhaust gas temperature is less than or equal to a second set temperature;

If the absolute value of the second temperature difference between the first oil return temperature and the exhaust gas temperature is less than or equal to the second set temperature, control the air conditioning system to exit the oil return control process and operate normally;

If the absolute value of the second temperature difference between the first return oil temperature and the exhaust gas temperature is greater than the second set temperature, then the first temperature difference between the first return oil temperature and the outdoor ambient temperature When the absolute value is greater than or equal to the fourth set temperature, the air-conditioning system is controlled to exit the oil return control process and operate normally; the absolute value of the first temperature difference between the first oil return temperature and the outdoor ambient temperature is less than In the case of the fourth set temperature, the air conditioning system is controlled to report the oil return protection shutdown fault.
The oil return control method of an air conditioning system according to claim 6, wherein the first switch unit is further determined according to the first oil return temperature, the second oil return temperature and the exhaust gas temperature and whether the second switch unit is normal, including:

determining whether the absolute value of a fifth temperature difference between the smaller of the first oil return temperature and the second oil return temperature and the exhaust gas temperature is greater than a second set temperature;

If the absolute value of the fifth temperature difference between the smaller of the first oil return temperature and the second oil return temperature and the exhaust gas temperature is greater than the second set temperature, then the first oil return When the absolute value of the sixth temperature difference between the smaller of the temperature and the second oil return temperature and the outdoor ambient temperature is greater than or equal to the fourth set temperature, the air conditioning system is controlled to exit the oil return control process, and Normal operation; when the absolute value of the sixth temperature difference between the smaller of the first oil return temperature and the second oil return temperature and the outdoor ambient temperature is smaller than the fourth set temperature, execute all The process of determining whether the first switch unit and the second switch unit are normal when the operating frequency of the compressor is less than or equal to a set frequency;

If the absolute value of the fifth temperature difference between the smaller of the first oil return temperature and the second oil return temperature and the exhaust gas temperature is less than or equal to the second set temperature, the air conditioning system is controlled to exit the return Oil control process, and operate normally.
An oil return control device for an air conditioning system, characterized in that the air conditioning system includes: a first oil return pipeline and a second oil return pipeline; a first switch unit is provided on the first oil return pipeline, and a first switch unit is provided on the first oil return pipeline. The second oil return pipeline is provided with a second switch unit; the oil return control device of the air conditioning system includes: an acquisition unit and a control unit; wherein,

The obtaining unit is configured to obtain the operating parameters of the air-conditioning system after the compressor of the air-conditioning system starts and runs for a first set period of time accumulatively;

The control unit is configured to determine whether the first switch unit and the second switch unit are normal according to the acquired operating parameters of the air conditioning system, so as to control the operation of the first switch unit and/or the second switch unit. When the switch unit is normal, the air conditioning system is controlled to operate normally and oil return is normal, and when the first switch unit and the second switch unit are abnormal, the air conditioning system is controlled to be shut down for oil return protection.
The oil return control device of an air conditioning system according to claim 9, wherein the operating parameters include: a first oil return temperature of the first oil return line, a second oil return line of the second oil return line Return oil temperature, operating frequency and discharge temperature of the compressor of the air conditioning system, and outdoor ambient temperature of the air conditioning system.
The oil return control device of an air conditioning system according to claim 10, wherein a first temperature detection unit is arranged on the first oil return pipeline, and a second temperature detection unit is arranged on the second oil return pipeline;

The obtaining unit obtains the first oil return temperature and the second oil return temperature in the operating parameters, including:

The first oil return temperature detected by the first temperature detection unit is acquired, and the second oil return temperature detected by the second temperature detection unit is acquired.
The oil return control device of an air conditioning system according to claim 11, wherein, in the air conditioning system, on the first oil return pipeline, the first temperature detection unit and the first switch unit A first throttling unit is also arranged therebetween; and a second throttling unit is also arranged on the second oil return pipeline, between the second temperature detection unit and the second switch unit.
The oil return control device for an air-conditioning system according to any one of claims 10 to 12, wherein the control unit determines the first switch unit and the second switch unit according to the operating parameter Is it normal, including:

If the operating frequency of the compressor is less than or equal to the set frequency, determine whether the absolute value of the first temperature difference between the first oil return temperature and the outdoor ambient temperature is greater than or equal to the first set temperature, and determine Whether the absolute value of the second temperature difference between the first oil return temperature and the exhaust gas temperature is less than or equal to the second set temperature;

If the absolute value of the first temperature difference between the first return oil temperature and the outdoor ambient temperature is greater than or equal to the first set temperature, and the second absolute value between the first return oil temperature and the exhaust gas temperature If the absolute value of the temperature difference is less than or equal to the second set temperature, it is determined that the first switch unit is normal, so as to control the first oil return pipeline to return oil;

If the absolute value of the first temperature difference between the first return oil temperature and the outdoor ambient temperature is less than the first set temperature, or the absolute value of the second temperature difference between the first return oil temperature and the exhaust gas temperature If the value is greater than the second set temperature, it is further determined whether the first switch unit and the second switch unit are normal according to the first oil return temperature and the second oil return temperature.
The oil return control device of an air conditioning system according to claim 13, wherein the control unit further determines the first switch unit and the second oil return temperature according to the first return oil temperature and the second oil return temperature. Whether the second switch unit is normal, including:

determining whether the absolute value of a third temperature difference between the first oil return temperature and the second oil return temperature is greater than or equal to a third set temperature;

If the absolute value of the third temperature difference between the first oil return temperature and the second oil return temperature is greater than or equal to a third set temperature, it is determined that the first switch unit is normal, so as to control the first oil return temperature Return oil to the oil pipeline;

If the absolute value of the third temperature difference between the first oil return temperature and the second oil return temperature is smaller than the third set temperature, it is determined that the first switch unit is abnormal, and the second switch unit is controlled to be turned on and, after the second set time period, if the absolute value of the fourth temperature difference between the second oil return temperature and the outdoor ambient temperature is less than or equal to the first set temperature, the air-conditioning system is controlled to report back Oil protection shutdown failure; if the absolute value of the fourth temperature difference between the second oil return temperature and the outdoor ambient temperature is greater than the first set temperature, the air conditioning system is controlled to exit the oil return control process and operate normally; wherein, The number of times of recovery of the oil return protection shutdown fault is limited.
The oil return control device for an air-conditioning system according to any one of claims 10 to 12, wherein the control unit determines the first switch unit and the second switch unit according to the operating parameter Is it normal, including:

If the operating frequency of the compressor is greater than the set frequency, determining whether the absolute value of the third temperature difference between the first oil return temperature and the second oil return temperature is less than a third set temperature;

If the absolute value of the third temperature difference between the first oil return temperature and the second oil return temperature is less than the third set temperature, further determine the temperature according to the first oil return temperature and the exhaust gas temperature. Whether the first switch unit and the second switch unit are normal;

If the absolute value of the third temperature difference between the first oil return temperature and the second oil return temperature is greater than the third set temperature, according to the first oil return temperature, the second oil return temperature and the and the exhaust gas temperature, and further determine whether the first switch unit and the second switch unit are normal.
The oil return control device of an air conditioning system according to claim 15, wherein the control unit further determines the first switch unit and the first switch unit according to the first return oil temperature and the exhaust temperature Whether the second switch unit is normal, including:

determining whether the absolute value of the second temperature difference between the first oil return temperature and the exhaust gas temperature is less than or equal to a second set temperature;

If the absolute value of the second temperature difference between the first oil return temperature and the exhaust gas temperature is less than or equal to the second set temperature, control the air conditioning system to exit the oil return control process and operate normally;

If the absolute value of the second temperature difference between the first return oil temperature and the exhaust gas temperature is greater than the second set temperature, then the first temperature difference between the first return oil temperature and the outdoor ambient temperature When the absolute value is greater than or equal to the fourth set temperature, the air-conditioning system is controlled to exit the oil return control process and operate normally; the absolute value of the first temperature difference between the first oil return temperature and the outdoor ambient temperature is less than In the case of the fourth set temperature, the air conditioning system is controlled to report the oil return protection shutdown fault.
The oil return control device of an air conditioning system according to claim 15, wherein the control unit further determines the oil return temperature according to the first oil return temperature, the second oil return temperature and the exhaust gas temperature. Whether the first switch unit and the second switch unit are normal, including:

determining whether the absolute value of a fifth temperature difference between the smaller of the first oil return temperature and the second oil return temperature and the exhaust gas temperature is greater than a second set temperature;

If the absolute value of the fifth temperature difference between the smaller of the first oil return temperature and the second oil return temperature and the exhaust gas temperature is greater than the second set temperature, then the first oil return When the absolute value of the sixth temperature difference between the smaller of the temperature and the second oil return temperature and the outdoor ambient temperature is greater than or equal to the fourth set temperature, the air conditioning system is controlled to exit the oil return control process, and Normal operation; when the absolute value of the sixth temperature difference between the smaller of the first oil return temperature and the second oil return temperature and the outdoor ambient temperature is smaller than the fourth set temperature, execute all The process of determining whether the first switch unit and the second switch unit are normal when the operating frequency of the compressor is less than or equal to a set frequency;

If the absolute value of the fifth temperature difference between the smaller of the first oil return temperature and the second oil return temperature and the exhaust gas temperature is less than or equal to the second set temperature, the air conditioning system is controlled to exit the return Oil control process, and operate normally.
An air conditioning system, characterized by comprising: the oil return control device of the air conditioning system according to any one of claims 9 to 17.