阅读说明：本技术 一种空调器回油控制方法及其系统、存储介质、空调器 (Air conditioner oil return control method and system, storage medium and air conditioner ) 是由 代文杰 颜华周 张一鹤 李真仲 杜泽锋 陈龙 于 2019-09-30 设计创作，主要内容包括：本发明公开了一种空调器回油控制方法及其系统、存储介质、空调器,所述方法包括步骤：实时检测油分离器中油位变化速度；根据油位变化速度调整回油膨胀阀的开度。能够根据油分离器中的油位变化速度来判断系统油量需求,通过调整油分离器回油膨胀阀的开度控制回油量,保证系统油量始终处于稳定均衡的状态。(The invention discloses an air conditioner oil return control method and a system thereof, a storage medium and an air conditioner, wherein the method comprises the following steps: detecting the oil level change speed in the oil separator in real time; and adjusting the opening degree of the oil return expansion valve according to the oil level change speed. The oil quantity requirement of the system can be judged according to the oil level change speed in the oil separator, the oil return quantity is controlled by adjusting the opening degree of an oil return expansion valve of the oil separator, and the oil quantity of the system is ensured to be always in a stable and balanced state.)

1. An oil return control method of an air conditioner is applied to the air conditioner, the air conditioner comprises an oil separator and an oil return expansion valve connected with the oil separator, and the oil return control method of the air conditioner is characterized by comprising the following steps:

detecting a speed of change of an oil level in the oil separator;

and adjusting the opening degree of the oil return expansion valve according to the oil level change speed.

2. The air conditioner oil return control method as claimed in claim 1, wherein the detecting a speed of change of an oil level in the oil separator includes:

acquiring the oil level variation in one period, and calculating the oil level variation speed according to the v ═ delta D/t process; where Δ D is an oil level variation amount in one period t, and v is an oil level variation speed.

3. The air conditioner oil return control method according to claim 2, wherein the adjusting of the opening degree of the oil return expansion valve according to the oil level change speed comprises:

when the oil level change speed is greater than a first preset speed, calculating a reduction amount of the oil return expansion valve and reducing the opening degree of the oil return expansion valve;

when the oil level change speed is lower than a second preset speed, calculating the increase amount of the oil return expansion valve and increasing the opening degree of the oil return expansion valve; wherein the second preset speed is less than the first preset speed.

4. The air conditioner oil return control method according to claim 3, wherein the amount of decrease of the oil return expansion valve is calculated according to a process of Δ P1 ═ n (v-Vs 1); wherein n is a first work coefficient of the oil return expansion valve, and Vs1 is the first preset speed.

5. The air conditioner oil return control method according to claim 3, wherein the increase amount of the oil return expansion valve is calculated according to a process of Δ P2 ═ m (Vs 2-v); wherein m is a second work coefficient of the oil return expansion valve, and Vs2 is the second preset speed.

6. The air conditioner oil return control method according to claim 1, further comprising, after adjusting the opening degree of the oil return expansion valve according to the oil level change speed:

and continuously detecting the oil level change speed in the oil separator in the next period until the air conditioner receives a shutdown command.

7. A storage medium storing an air conditioner oil return control program, wherein the air conditioner oil return control program is executed to implement the steps of the air conditioner oil return control method according to any one of claims 1 to 6.

8. An air conditioner oil return control system, characterized by comprising: the storage medium of claim 7;

the processor is connected with the storage medium and used for executing the air conditioner oil return control program stored in the storage medium;

the oil level detection module is used for detecting the change speed of the oil level in the oil separator;

and the oil return expansion valve adjusting module is used for adjusting the opening of the oil return expansion valve according to the oil level change speed.

9. An air conditioner characterized by comprising the air conditioner oil return control system as claimed in claim 8.

Technical Field

The invention relates to the technical field of air conditioners, in particular to an oil return control method and an oil return control system for an air conditioner.

Background

The multi-connected air conditioner has the characteristics of more internal machines, long pipelines and large fall, so the requirement on lubricating oil is higher, but the suction quantity of the lubricating oil is too much or too little, and the negative effect is realized on the capacity and the energy efficiency. At present, in the multi-split air conditioner industry, oil return operation control is mainly performed according to the load output size and time of an air conditioner, the amount of lubricating oil returning from oil is basically in a fixed flow mode, and flow control components such as a capillary tube are adopted for control.

The real oil quantity requirement condition of the system can not be well fed back, the oil return quantity requirement of the lubricating oil is different under different load, pressure and temperature conditions, and the basic idea of the oil return is to make sufficient allowance at present and ensure the worst oil return reliability. The control mode is not beneficial to the optimal effect of the energy efficiency, and the improvement of the energy-saving efficiency of the multi-split air conditioner is limited.

Accordingly, the prior art is yet to be improved and developed.

Disclosure of Invention

The present invention provides an oil return control method and system for an air conditioner, aiming at solving the technical problem that the air conditioner in the prior art cannot adjust the oil return amount according to the oil amount requirement of the system.

The technical scheme adopted by the invention for solving the technical problem is as follows:

an oil return control method of an air conditioner is applied to the air conditioner, the air conditioner comprises an oil separator and an oil return expansion valve connected with the oil separator, and the method comprises the following steps:

detecting the oil level change speed in the oil separator;

and adjusting the opening degree of the oil return expansion valve according to the oil level change speed.

The oil return control method for the air conditioner, wherein the detecting of the oil level change speed in the oil separator comprises the following steps:

acquiring the oil level variation in one period, and calculating the oil level variation speed according to the v ═ delta D/t process; where Δ D is an oil level variation amount in one period t, and v is an oil level variation speed.

The oil return control method of the air conditioner, wherein the adjusting of the opening degree of the oil return expansion valve according to the oil level change speed comprises the following steps:

when the oil level change speed is greater than a first preset speed, calculating the reduction amount of the oil return expansion valve and reducing the opening degree of the oil return expansion valve;

when the oil level change speed is lower than a second preset speed, calculating the increase amount of the oil return expansion valve and increasing the opening degree of the oil return expansion valve; wherein the second preset speed is less than the first preset speed.

The oil return control method of the air conditioner is characterized in that the reduction amount of the oil return expansion valve is calculated according to the process that delta P1 is equal to n (v-Vs 1); wherein n is a first work coefficient of the oil return expansion valve, and Vs1 is the first preset speed.

The air conditioner oil return control method is characterized in that the increase amount of the oil return expansion valve is calculated according to the process that delta P2 is m (Vs 2-v); wherein m is a second work coefficient of the oil return expansion valve, and Vs2 is the second preset speed.

The oil return control method of the air conditioner, wherein the step of adjusting the opening degree of the oil return expansion valve according to the oil level change speed further comprises the following steps:

and continuously detecting the oil level change speed in the oil separator in the next period until the air conditioner receives a shutdown command.

A storage medium storing an air conditioner oil return control program, wherein the air conditioner oil return control program, when executed, implements the steps of the air conditioner oil return control method as recited in any one of the above.

An air conditioner oil return control system, comprising:

the processor is connected with the storage medium and used for executing the air conditioner oil return control program stored in the storage medium;

the oil level detection module is used for detecting the change speed of the oil level in the oil separator;

and the oil return expansion valve adjusting module is used for adjusting the opening of the oil return expansion valve according to the oil level change speed.

An air conditioner comprises the air conditioner oil return control system.

The oil quantity demand of the system can be judged according to the oil level change speed in the oil separator, and the oil return quantity is controlled by adjusting the opening degree of an oil return expansion valve of the oil separator, so that the oil quantity of the system is always in a stable and balanced state.

Drawings

Fig. 1 is a flow chart of an oil return control method of an air conditioner in the invention.

Fig. 2 is a schematic structural view of an air conditioner according to the present invention.

FIG. 3 is a schematic view of an oil separator according to the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention clearer and clearer, the present invention is further described in detail below with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

Referring to fig. 1 to 3, the present invention provides embodiments of an oil return control method for an air conditioner.

As shown in fig. 2, the air conditioner includes: the system comprises a compressor 1, an oil separator 2, an oil return expansion valve 3, a liquid storage tank 4, a four-way valve 5, an outdoor heat exchanger 6 and a heating expansion valve 7; the heating expansion valve 7 is communicated with the outdoor heat exchanger 6, the outdoor heat exchanger 6 is communicated with a port C of the four-way valve 5, the top end of the oil separator 2 is communicated with a port D of the four-way valve 5, one end of the liquid storage tank 4 is communicated with a port S of the four-way valve 5, the other end of the liquid storage tank 4 is communicated with the top end of the compressor 1, the bottom end of the liquid storage tank 4 is communicated with the bottom end of the oil separator 2 through the oil return expansion valve 3, and the top end of the oil separator 2 is. The components of the present invention include an oil separator 2 and an oil return expansion valve 3.

As shown in fig. 1, the oil return control method for an air conditioner according to the embodiment of the present invention is applied to an air conditioner, and includes the following steps:

step S100, detecting the oil level change speed in the oil separator 2.

Specifically, as shown in fig. 3, the oil separator 2 is provided with a plurality of oil level sensors in sequence from top to bottom, and the oil level of the lubricating oil in the oil separator 2 can be obtained according to the oil level sensors. An appropriate number of fuel level sensors are selected according to the accuracy of the required fuel level and the range of the fuel level, and fuel level sensors of different densities may be provided at different locations with the separator.

More specifically, as shown in fig. 3, the oil level sensor includes a positive electrode 21 and a negative electrode 22, and if there is oil between the positive electrode 21 and the negative electrode 22, conduction is made between the positive electrode 21 and the negative electrode 22, and current flows, by utilizing the conductivity of the lubricating oil. If there is no oil between the cathode 21 and the anode 22, the cathode 21 and the anode 22 are disconnected from each other, and no current flows. The oil level of the lubricating oil can be obtained through the on-off state of each oil level sensor, the change condition of the oil level of the system at the moment is calculated and evaluated, and therefore the oil return quantity of the system is judged to be increased or decreased, and finally the purpose of controlling oil return is achieved through adjusting the opening degree of the oil return expansion valve 3.

After the air conditioner oil return control system is started, the compressor 1 is started, the oil level change speed in the oil separator 2 is detected, specifically, the oil level of the lubricating oil is detected once every t time with the time t as one period, so that the oil level at the initial time of the t time (namely, the initial oil level D1) and the oil level at the end time of the t time (namely, the end oil level D2) can be obtained, the oil level change quantity Δ D in the period t is D2-D1, and the oil level change speed v is v ═ Δ D/t (D2-D1)/t.

Here, the oil level change speed v is divided into positive and negative values, and positive values indicate that the oil level is increasing, and negative values indicate that the oil level is decreasing.

And step S200, adjusting the opening of the return oil expansion valve according to the oil level change speed.

Adjusting the opening degree of the return expansion valve according to the oil level change speed, namely, when the oil level change speed is too high, reducing the opening degree of the return expansion valve and reducing the oil level change speed; when the oil level change speed is too small, the opening degree of the return oil expansion valve is increased to increase the oil level change speed. The target speed is compared with the oil level change speed by setting the target speed in advance, where there are two target speeds, a first preset speed and a second preset speed, respectively.

The step S200 specifically includes:

and step S210, when the oil level change speed is greater than a first preset speed, calculating the reduction amount of the oil return expansion valve and reducing the opening degree of the oil return expansion valve.

The oil level change speed is greater than a first preset speed Vs1, namely v is greater than Vs1, the oil level increase speed exceeds the system design requirement, the oil return amount is large, the oil return amount of the compressor 1 is greater than the required oil amount, the large oil return amount increases the suction superheat degree of refrigerant and reduces the effective suction refrigerant amount, the air conditioner has an ineffective effect, and the energy efficiency is increased. The corresponding solution or control means is to reduce the opening degree of the oil return expansion valve and reduce the oil return amount.

Specifically, the reduction amount of the return-oil expansion valve is calculated according to the process of Δ P1 ═ n (v-Vs 1); and n is a first working coefficient of the oil return expansion valve, the numerical value is different according to different air conditioner operation conditions, the coefficient is related to an opening action curve of the oil return expansion valve and is determined by combining actual oil return amount. v is the oil level change speed, and Vs1 is the first preset speed.

Step S220, when the oil level change speed is lower than a second preset speed, calculating the increase amount of the oil return expansion valve and increasing the opening degree of the oil return expansion valve; wherein the second preset speed is less than the first preset speed.

The oil level change speed is less than a second preset speed Vs2, namely v < Vs2, which indicates that the oil level is decreased at a speed exceeding the design requirement of the system, the oil return amount is small, the oil return amount of the compressor 1 is less than the required oil amount, and the oil return shortage easily causes the oil amount inside the compressor 1 to be continuously reduced, so that the lubricating effect of the high-speed operation of the compressor 1 is finally endangered, and the abnormal wear of the compressor 1 is caused. The corresponding solution or control means is to increase the opening of the oil return expansion valve and increase the oil return amount.

Specifically, the increase amount of the return oil expansion valve is calculated according to the process of Δ P2 ═ m × (Vs 2-v); and m is a second working coefficient of the oil return expansion valve, the numerical value is different according to different air conditioner operation conditions, the coefficient is related to an opening action curve of the oil return expansion valve and is determined by combining actual oil return quantity. v is the oil level change speed, and Vs2 is a second preset speed.

And step S230, when the oil level change speed is between the first preset speed and the second preset speed, maintaining the opening degree of the oil return expansion valve.

Specifically, the oil level change speed is between a first preset speed Vs1 and a second preset speed Vs2, namely Vs2 is not less than v and not more than Vs1, which indicates that the oil level change speed is changed within the system design requirement range, the oil return amount of the compressor 1 is consistent with the required oil amount, the air conditioner operates in a balance state between reliability and high energy efficiency, the oil return amount does not need to be increased or reduced, and therefore the oil return expansion valve does not need to act.

And step S300, continuously detecting the oil level change speed in the oil separator in the next period until the air conditioner receives a shutdown instruction.

After a detection and adjustment action is completed, namely after the oil return speed is calculated and the opening degree of the oil return expansion valve is adjusted, the system may reach a relatively stable state, and the condition that the oil level is not adjusted in place exists, so that the oil level detection and adjustment action enters the adjustment of the next period. The reciprocating circulation continuously adjusts the oil return expansion valve, and the oil quantity of the compressor 1 is always in an optimal state. And when the system or the air conditioner receives a shutdown command and the compressor 1 stops running, the oil return expansion valve pushes out oil return control and closes the oil return expansion valve, so that the system does not need oil return.