CN220083379U - Air conditioner - Google Patents

Abstract

The utility model provides an air conditioner. According to the running frequency of the current compressor and the refrigerating mode or heating mode of the air conditioner, the opening quantity and the closing quantity of the electric control valves are controlled to achieve the purpose of throttling and cooling liquid flowing out of the oil separator, the reasonable distribution of the liquid is achieved, and the effect of accurately controlling oil return is achieved; the outlet of the oil separator is divided into four pipelines, the first pipeline is only connected with the first capillary, the second capillary is the generic name of other three capillaries, and the other three pipelines are sequentially connected with the capillaries and the electric control valve from the outlet of the oil separator; the outlets of the four pipelines are converged into one pipeline and then connected with the temperature sensor.

Description

Air conditioner

Technical Field

The utility model relates to the technical field of air conditioners, in particular to an air conditioner.

Background

With the popularization of air conditioners, the durability and stability of the refrigerating effect of the compressor are more and more important, but poor oil return is an important factor for damaging the compressor, and how to control the oil return of the compressor becomes a key for protecting the compressor. The existing oil return mode is to connect the capillary tube at the outlet of the oil separator to ensure smooth oil return of the compressor at the maximum operating frequency, but the oil discharge amount of the compressor is different at different frequencies, especially the oil discharge rate is low at the low frequency of the compressor, and at this time, the high-temperature high-pressure gas refrigerant is conveyed to the low-pressure end of the compressor through the capillary tube, so that the high-pressure end and the low-pressure end of the compressor are in gas leakage, and the operating power of the compressor in the low-frequency state is lost.

Disclosure of Invention

In view of the above problems, the present utility model has been made to provide an air conditioner that overcomes or at least partially solves the above problems, and can solve the problem of air leakage between the high-pressure end and the low-pressure end of the compressor at low frequencies, thereby achieving the purpose of improving user experience.

Specifically, the present utility model provides an air conditioner, comprising:

a compressor forming a high pressure end and a low pressure end to drive a medium into and out of the low pressure end;

an oil separator forming at least an inlet connected to a high-pressure end of the compressor and a return port for returning the medium to the low-pressure end;

the first capillary tube is directly connected between the reflux port of the oil separator and the low-pressure end of the compressor;

and the second capillary tube is arranged in parallel with the first capillary tube, one end of the second capillary tube is connected with a reflux port of the oil separator, and the other end of the second capillary tube is connected with the low-pressure end of the compressor through an electric control valve.

Optionally, the second capillaries have more than two and are mutually arranged in parallel, and each second capillary is correspondingly connected with the electric control valve in series.

Optionally, the second capillaries have three.

Optionally, a temperature sensor is further connected between the return port of the oil separator and the low pressure end of the compressor.

Optionally, the temperature sensor is at an outlet of the first capillary tube and/or an outlet of the second capillary tube.

Optionally, the outlet of the first capillary tube and the outlet of the second capillary tube are converged and then connected with the temperature sensor, so that the low-pressure end of the compressor is connected through the temperature sensor.

Optionally, the outlet of the first capillary tube and the outlet of the electric control valve are converged and then connected with the temperature sensor, so that the low-pressure end of the compressor is connected through the temperature sensor.

Optionally, the outlet of the first capillary tube and/or the outlet of the second capillary tube is connected between the compressor and the gas-liquid separator.

Optionally, the second capillaries have at least two, wherein at least two of the second capillaries have equal length and equal diameter.

Optionally, an oil level sensor is not disposed in the oil separator.

The utility model provides an air conditioner, which is characterized in that a first capillary tube and a second capillary tube are connected in parallel between a reflux port of an oil separator and a low-pressure end of a compressor, and an electric control valve is connected to the second capillary tube so as to control the open and close states of the second capillary tube, and particularly the electric control valve is positioned between the second capillary tube and the compressor, so that a high-pressure medium is buffered in the capillary tube, the control reaction speed of the electric control valve on medium reflux is faster, and the user experience is improved.

The above, as well as additional objectives, advantages, and features of the present utility model will become apparent to those skilled in the art from the following detailed description of a specific embodiment of the present utility model when read in conjunction with the accompanying drawings.

Drawings

Some specific embodiments of the utility model will be described in detail hereinafter by way of example and not by way of limitation with reference to the accompanying drawings. The same reference numbers will be used throughout the drawings to refer to the same or like parts or portions. It will be appreciated by those skilled in the art that the drawings are not necessarily drawn to scale. In the accompanying drawings:

fig. 1 is a schematic structural view of an oil return apparatus in an air conditioner according to an embodiment of the present utility model.

Detailed Description

An embodiment of the present utility model is described below with reference to fig. 1. In the description of the present embodiment, it should be understood that the terms "first" and "second" are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include at least one such feature, i.e. one or more such features. In the description of the present utility model, the meaning of "plurality" means at least two, for example, two, three, etc., unless specifically defined otherwise. When a feature "comprises or includes" a feature or some of its coverage, this indicates that other features are not excluded and may further include other features, unless expressly stated otherwise.

Unless specifically stated or limited otherwise, the terms "disposed," "mounted," "connected," "secured," "coupled," and the like should be construed broadly, as they may be connected, either permanently or removably, or integrally; can be mechanically or electrically connected; either directly or indirectly, through intermediaries, or both, may be in communication with each other or in interaction with each other, unless expressly defined otherwise. Those of ordinary skill in the art will understand the specific meaning of the terms described above in the present utility model as the case may be.

Furthermore, in the description of the present embodiments, a first feature "above" or "below" a second feature may include the first and second features being in direct contact, or may include the first and second features not being in direct contact but being in contact through another feature therebetween. That is, in the description of the present embodiment, the first feature being "above", "over" and "upper" the second feature includes the first feature being directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature "under", "beneath", or "under" a second feature may be a first feature directly under or diagonally under the second feature, or simply indicate that the first feature is less level than the second feature.

In the description of the present embodiment, a description referring to the terms "one embodiment," "some embodiments," "illustrative embodiments," "examples," "specific examples," or "some examples," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present utility model. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiments or examples. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

Fig. 1 is a schematic structural view of an oil return device in an air conditioner according to an embodiment of the present utility model, and as shown in fig. 1, an embodiment of the present utility model provides an air conditioner, in which a medium flows into an oil separator 9 after flowing out from a high pressure end of a compressor 10, and a liquid in the oil separator 9 is split at an outlet of the oil separator 9 through a first capillary tube 1 and/or a second capillary tube; according to the current operation frequency of the compressor 10, the opening or closing of the electric control valve is controlled, so that reasonable distribution of liquid is realized, the effect of accurately controlling oil return is achieved, and the liquid from the first capillary tube 1 and/or the second capillary tube flows through the temperature sensor 8 after converging and then flows into the low-pressure end of the compressor 10; wherein the temperature sensor 8 monitors the liquid temperature after confluence, and when the liquid temperature after confluence is smaller than a minimum set value and the duration exceeds a minimum time value, the air conditioner alarms and stops.

In some embodiments of the present utility model, an air conditioner includes:

a compressor 10 forming a high pressure end and a low pressure end to drive a medium into and out of the low pressure end;

an oil separator 9 forming at least an inlet connected to a high-pressure end of the compressor 10 and a return port for returning the medium to the low-pressure end;

a first capillary tube 1 directly connected between a return port of the oil separator 9 and a low pressure end of the compressor 10;

and a second capillary tube which is arranged in parallel with the first capillary tube 1, one end of which is connected with a reflux port of the oil separator 9, and the other end of which is connected with a low-pressure end of the compressor 10 through an electric control valve.

In this embodiment, according to the current operating frequency of the compressor 10 and the refrigeration mode or heating mode of the air conditioner, the number of opened and closed electric control valves is controlled to achieve the purpose of throttling and cooling the liquid flowing out of the oil separator 9, and meanwhile, reasonable distribution of the liquid is achieved, and the effect of accurately controlling oil return is achieved; the electric control valve comprises a first electric control valve 5, a second electric control valve 6 and a third electric control valve 7; the outlet of the oil separator 9 is divided into four pipelines, wherein the first pipeline is only connected with the first capillary 1, the second capillary is a generic name of other three capillaries, and the other three pipelines are sequentially connected with the capillaries and the electric control valve from the outlet of the oil separator 9; the outlets of the four pipelines are converged into one pipeline and then connected with a temperature sensor 8, and the electric control valve adopted by the utility model can be various valves which can be automatically controlled, such as an electromagnetic valve and an electronic expansion valve.

In some embodiments of the present utility model, the second capillaries have more than two capillaries and are arranged in parallel, and each of the second capillaries is provided with the electrically controlled valve in series corresponding to each other.

In this embodiment, at least two second capillaries are provided, referring to fig. 1, the second capillaries include a third capillary 2, a fourth capillary 3 and a fifth capillary 4, the third capillary 2, the fourth capillary 3 and the fifth capillary 4 are in parallel connection with each other, the third capillary 2 is connected in series with an electric control valve 5, the fourth capillary 3 is connected in series with an electric control valve 6, and the fifth capillary 4 is connected in series with an electric control gate 7; the electric control valve 5, the electric control valve 6 and the electric control valve 7 are also in parallel connection with each other.

In some embodiments of the utility model, the second capillaries have three.

The second capillary has three, namely a third capillary 2, a fourth capillary 3 and a fifth capillary 4.

In some embodiments of the utility model, a temperature sensor 8 is also connected between the return port of the oil separator 9 and the low pressure end of the compressor 10.

The temperature sensor 8 is located between the return port of the oil separator 9 and the low pressure end of the compressor 10 to monitor the temperature of the liquid flowing therethrough.

In some embodiments of the utility model, the temperature sensor 8 is at the outlet of the first capillary 1 and/or the outlet of the second capillary.

The specific positions of the temperature sensor are connected after the outlet of the first capillary 1, the outlet of the third capillary 2, the outlet of the fourth capillary 3 and the outlet of the fifth capillary 4.

In some embodiments of the present utility model, the outlet of the first capillary tube 1 and the outlet of the second capillary tube are connected to the temperature sensor 8 after confluence to connect the low pressure end of the compressor 10 via the temperature sensor 8.

The temperature sensor 8 monitors the temperature of the liquid after the reflux, and the outlet of the first capillary 1 and the outlet of the third capillary 2, the outlet of the fourth capillary 3 and the outlet of the fifth capillary 4 are connected with the temperature sensor 8 after being converged so as to be connected with the low pressure end of the compressor 10 via the temperature sensor 8.

In some embodiments of the present utility model, the outlet of the first capillary tube 1 and the outlet of the electronically controlled valve are connected to the temperature sensor 8 after converging, so as to be connected to the low pressure end of the compressor 10 via the temperature sensor 8.

The electric control valve comprises a first electric control valve 5, a second electric control valve 6 and a third electric control valve 7, and the outlet of the first capillary tube 1, the outlet of the first electric control valve 5, the outlet of the second electric control valve 6 and the outlet of the third electric control valve 7 are connected with a temperature sensor 8 after converging so as to be connected with the low-pressure end of the compressor 10 through the temperature sensor 8.

In some embodiments of the utility model, the outlet of the first capillary tube 1 and/or the outlet of the second capillary tube is connected between the compressor 10 and the gas-liquid separator 11.

The outlet of the first capillary 1, the outlet of the third capillary 2, the outlet of the fourth capillary 3 and the outlet of the fifth capillary 4 are connected to a pipeline between the compressor 10 and the gas-liquid separator 11 through pipelines after converging.

In some embodiments of the utility model, the second capillary has at least two, wherein at least two of the second capillaries have equal diameters.

Referring to fig. 1, the second capillary includes a third capillary 2, a fourth capillary 3, and a fifth capillary 4, and the third capillary 2, the fourth capillary 3, and the fifth capillary 4 have the same length and the same pipe diameter.

In some embodiments of the present utility model, no oil level sensor is provided in the oil separator 9.

According to the utility model, reasonable distribution of oil is realized by controlling the opening quantity and the closing quantity of the electric control valves, oil return is accurately controlled, the oil level in the oil separator 9 is not required to be monitored by arranging an oil level sensor, and the cost is saved.

In some embodiments of the present utility model, when the operation frequency of the compressor 10 is smaller than the first set frequency in the refrigerating or heating state of the air conditioner, the first electric control valve 5, the second electric control valve 6 and the third electric control valve 7 are all closed, so as to realize reasonable distribution of liquid and achieve the effect of accurately controlling oil return, and the first set frequency is 40% of the maximum set frequency.

When the operation frequency of the compressor 10 is larger than the first set frequency and smaller than the second set frequency in the refrigerating or heating state of the air conditioner, namely, the operation frequency of the compressor 10 is between 40% and 70% of the maximum set frequency, the first electric control valve 5 is opened, the second electric control valve 6 and the third electric control valve 7 are closed, reasonable distribution of liquid is achieved, the oil return effect is accurately controlled, and the second set frequency is 70% of the maximum set frequency.

When the operation frequency of the compressor 10 is equal to the second set frequency and the air conditioner is in a refrigerating state, the first electric control valve 5 and the second electric control valve 6 are opened, and the third electric control valve 7 is closed, so that reasonable distribution of liquid is realized, and the effect of accurately controlling oil return is achieved.

When the operation frequency of the compressor 10 is greater than the second set frequency and less than the third set frequency and the air conditioner is in the heating mode, the first and second electric control valves 5 and 6 are opened and the third electric control valve 7 is closed. When the operation frequency of the compressor 10 is greater than the maximum cooling frequency and less than the maximum heating frequency, that is, the operation frequency of the compressor 10 is between 70% and 100% of the maximum setting frequency, the first electric control valve 5 and the second electric control valve 6 are opened, the third electric control valve 7 is closed, the reasonable distribution of liquid is realized, the oil return effect is accurately controlled, and the third setting frequency is as follows: 100% maximum set frequency.

When the operation frequency of the compressor 10 is equal to the third set frequency and the air conditioner is in the heating mode, the first electric control valve 5, the second electric control valve 6 and the third electric control valve 7 are all opened, so that reasonable distribution of liquid in the state is realized, and the third set frequency is as follows: 100% maximum set frequency.

In addition, the maximum frequency of the compressor 10 operating frequency in the cooling state is the second set frequency: 70% maximum setting frequency, the maximum frequency of the compressor 10 operating frequency in the heating state is the third setting frequency: 100% maximum set frequency.

The temperature sensor 8 is arranged on a pipeline formed by converging the outlets of the first capillary tube 1, the first electric control valve 5, the second electric control valve 6 and the third electric control valve 7, and the temperature sensor 8 is used for monitoring the converged oil temperature. When the temperature sensor 8 monitors that the combined oil temperature is smaller than the minimum set value and the duration exceeds the minimum time value, the air conditioner alarms and stops; the minimum set value of the oil temperature is 5 ℃, and the minimum time value is: 60s, can be set according to the local situation and the condition of the air conditioner.

In some embodiments of the present utility model, the air conditioner includes a controller, the controller includes a processor and a memory, the memory is used for storing frequency information of the compressor 10, information of the electric control valve and information of the temperature sensor 8, the processor is used for processing the frequency information of the compressor 10, the information of the electric control valve and controlling opening or closing of the first electric control valve 5, the second electric control valve 6 and the third electric control valve 7, and reasonably distributing liquid in the oil separator 9, so as to achieve the effect of accurately controlling oil return; the processor decides whether to control the alarm stop of the air conditioner according to the oil temperature information monitored by the temperature sensor 8.

In the utility model, the on-off control of the electric control valve is adopted to control the reflux quantity of liquid in the oil separator 9, so that the capillary tube is prevented from being blocked when the electric control valve is closed, the operation reliability of the compressor 10 is ensured, the air conditioner is ensured to normally operate under various working conditions, the cross gas loss and reactive power caused by the low frequency of the compressor are reduced, and the energy is saved and the loss is prevented.

In other embodiments of the present utility model, the electronic control valve may be a valve for controlling opening and closing as described above, or may be an electronic expansion valve, where when the electronic expansion valve is adopted, an oil level sensor may be disposed on the oil separator in a matching manner, and the specific working process is as follows:

acquiring the operating frequency of the compressor 10 and the measured liquid level in the oil separator 9;

according to the operating frequency, a first set liquid level of the oil separator 9 is adjusted;

and controlling the opening of the electronic expansion valve according to the relative relation between the actually measured liquid level and the first set liquid level.

The control method comprises the steps of firstly obtaining the running frequency of the current compressor 10, the actual measured liquid level in the oil separator 9 and the running mode of the current air conditioner, finding a set frequency interval corresponding to the running frequency of the compressor 10 according to a corresponding relation table, and finding a corresponding first set liquid level according to the set frequency interval; and comparing the relative relation between the actually measured liquid level and the first set liquid level, if the actually measured liquid level is within the first set liquid level range, continuously maintaining the opening of the current electronic expansion valve, if the actually measured liquid level is not within the first set liquid level range, determining a set condition according to the current state, calculating the corresponding opening of the electronic expansion valve according to the set condition, and finally adjusting the opening of the electronic expansion valve to the corresponding opening.

According to the operating frequency, the adjusting the first set liquid level of the oil separator 9 includes:

obtaining the corresponding relation between the first set liquid level and a set frequency interval, wherein the set frequency interval is at least two and corresponds to different first set liquid levels; and judging the set frequency interval in which the operating frequency is located, and obtaining the first set liquid level corresponding to the operating frequency according to the corresponding relation between the first set liquid level and the set frequency interval.

Firstly, the operation frequency of the compressor 10 is obtained, and a set frequency interval where the operation frequency is located is found according to a corresponding relation table, wherein at least two set frequency intervals are provided, and the low frequency range is provided: the operating frequency is less than 40% of the set frequency, and the intermediate frequency is: operating frequency 40% -80% set frequency, also high frequency band: 80% -100% of set frequency; the high frequency band and the first set liquid level do not need to be corresponding, the middle frequency band and the low frequency band correspond to different first set liquid levels, and the corresponding first set liquid levels are found according to the found set frequency interval in the corresponding relation table.

The obtaining the operating frequency of the compressor 10 and the measured liquid level of the oil separator 9 includes: and acquiring the running frequency and/or the measured liquid level at intervals of set time as a response that the measured liquid level reaches a first set condition.

The first set condition means that the measured liquid level detected by the oil level sensor exceeds the upper limit of the first set liquid level or the lower limit of the first set liquid level; before the formula calculation in the first setting condition is performed, the operating frequency of the current compressor 10 and the actually measured liquid level need to be obtained, the range of the current first setting liquid level is obtained according to the operating frequency of the current compressor 10, then the relation between the range of the first setting liquid level and the actually measured liquid level is compared, and after the actually measured liquid level exceeds the upper limit of the first setting liquid level or is lower than the lower limit of the first setting liquid level, the opening of the electronic expansion valve at the position is calculated according to the first setting condition.

The first set liquid level comprises an upper limit of the first set liquid level and/or a lower limit of the first set liquid level; and said obtaining the operating frequency of said compressor 10, and the measured level of said oil separator 9, comprises:

if the measured liquid level exceeds the upper limit of the first set liquid level or is lower than the lower limit of the first set liquid level, detecting the measured liquid level of the oil separator 9 again after a first set time; or alternatively

If the measured liquid level is between the upper limit of the first set liquid level and the lower limit of the first set liquid level after the first set time, the measured liquid level of the oil separator 9 is detected again or not after the second set time.

The oil level sensor detects that the actually measured liquid level exceeds the upper limit of the first set liquid level for the first time or is lower than the lower limit of the first set liquid level for the first time, after a time interval t, the oil level sensor detects whether the actually measured liquid level is in the range of the first set liquid level of the corresponding frequency section again, if the actually measured liquid level is not in the range of the first set liquid level, the opening degree of the electronic expansion valve is continuously adjusted according to a set rule, the actually measured liquid level is detected again after the time interval t, and after the first set liquid level upper limit or the first set liquid level lower limit is triggered each time, the actually measured liquid level is required to be detected again after the time interval t until the actually measured liquid level is detected and does not trigger the first set liquid level upper limit and the first set liquid level lower limit. In the time interval t, the actual measured liquid level is adjusted in the time due to the change of the opening of the electronic expansion valve.

Detecting that the measured liquid level is in a first set liquid level range, and detecting the measured liquid level again or not after a time interval of 2t is needed after the first set liquid level upper limit and the first set liquid level lower limit are not triggered; and when the measured liquid level exceeds the upper limit of the first set liquid level or is lower than the lower limit of the first set liquid level, adjusting the opening of the electronic expansion valve, detecting whether the measured liquid level is in the first set liquid level range of the corresponding frequency band again through a time interval t, and if not, continuing to repeat the process.

The controlling the opening of the electronic expansion valve according to the relative relation between the measured liquid level and the first set liquid level comprises the following steps:

acquiring the initial opening and the current opening of the electronic expansion valve;

and in response to the relative relation between the actually measured liquid level and the first set liquid level reaching a second set condition, calculating the corresponding opening of the electronic expansion valve according to the second set condition by using the initial opening and/or the current opening.

The second setting condition is a formula for calculating the opening of the electronic expansion valve at the position according to the initial opening and the current opening after the actually measured liquid level reaches the first setting condition, and the formula comprises: in the time 2t, the actually measured liquid level only exceeds the upper limit of the first set liquid level once, the opening K=the current opening K+the initial opening K is needed to be positioned, or the actually measured liquid level is lower than the lower limit of the first set liquid level once, and the opening K=the current opening K-the initial opening K is needed to be positioned; in the time 2t, the measured liquid level exceeds the first set liquid level upper limit once and is lower than the first set liquid level lower limit for the other time in two continuous times, when the measured liquid level exceeds the first set liquid level upper limit for the second time, the corresponding opening K=the current opening K+ correction opening K/2 of the electronic expansion valve or when the measured liquid level exceeds the first set liquid level upper limit for the second time, the corresponding opening K=the current opening K-correction opening K/2 of the electronic expansion valve 3; firstly, the initial opening K and the current opening K of the electronic expansion valve are obtained, and then the opening of the electronic expansion valve at the position is calculated according to the second setting condition.

And calculating the corresponding opening of the electronic expansion valve according to the second setting condition by using the initial opening and/or the current opening, wherein the method comprises the following steps:

when the measured liquid level is not lower than the first set liquid level, the corresponding opening is equal to the sum of the initial opening and the current opening; or alternatively

And when the measured liquid level is not higher than the first set liquid level, the corresponding opening is equal to the difference between the current opening and the initial opening.

When the operating frequency of the compressor 10 is controlled at the intermediate frequency, the upper limit x=1/4 of the first set liquid level and the lower limit y=1/8 of the first set liquid level; in the oil return process, when the oil level sensor detects that the actually measured liquid level is greater than 1/4 liquid level, the opening of the electronic expansion valve to be adjusted to the position is calculated according to a set rule: k=k+k, and the controller controls the opening of the electronic expansion valve to be adjusted to the opening K where the electronic expansion valve should be located; or in the oil return process, when the oil level sensor detects that the measured liquid level is smaller than 1/8 liquid level, calculating the opening of the electronic expansion valve to be adjusted to the position according to a set rule: k=k-K, and the controller controls the opening degree of the electronic expansion valve to be adjusted to the corresponding opening degree K.

When the operating frequency of the compressor 10 is controlled in the low frequency range, the upper limit x=1/2 of the first set liquid level and the lower limit y=1/4 of the first set liquid level; in the oil return process, when the oil level sensor detects that the actually measured liquid level is greater than 1/2 liquid level, the opening of the electronic expansion valve to be adjusted to the position is calculated according to a set rule: k=k+k, and the controller controls the opening of the electronic expansion valve to be adjusted to the opening K where the electronic expansion valve should be located; or in the oil return process, when the oil level sensor detects that the measured liquid level is smaller than 1/4 liquid level, calculating the opening of the electronic expansion valve to be adjusted to the position according to a set rule: k=k-K, and the controller controls the opening degree of the electronic expansion valve to be adjusted to the corresponding opening degree K.

And calculating the corresponding opening of the electronic expansion valve according to the second setting condition by using the initial opening and/or the current opening, wherein the method comprises the following steps:

obtaining a corrected opening according to the initial opening as a response to the number of times that the actually measured liquid level is not lower than or not higher than the first set liquid level reaches a set number of times within a set time; and

when the measured liquid level is not lower than the first set liquid level, the corresponding opening is equal to the sum of the corrected opening and the current opening; or alternatively

And when the measured liquid level is not higher than the first set liquid level, the corresponding opening is equal to the difference between the current opening and the corrected opening.

When the measured liquid level is not lower than or not higher than the first set liquid level at least twice continuously in the set time, obtaining a corrected opening k/2 according to the initial opening k, and when the measured liquid level is detected to be lower than the first set liquid level lower limit of the corresponding frequency band for the first time, and when the measured liquid level is detected to be higher than the first set liquid level upper limit of the corresponding frequency band for the second time, calculating the opening of the electronic expansion valve to be adjusted to the position according to a set rule: K=K-K/2, and adjusting the opening of the electronic expansion valve to be the corresponding opening K; when the measured liquid level is detected to be higher than the first set liquid level upper limit of the corresponding frequency band for the first time, and when the measured liquid level is detected to be lower than the first set liquid level lower limit of the corresponding frequency band for the second time, calculating the corresponding opening degree to which the electronic expansion valve needs to be adjusted according to a set rule: k=k-K/2, and the opening of the electronic expansion valve is adjusted to the corresponding opening K.

The control method further includes:

in response to the operating frequency of the compressor 10 not being below a first frequency threshold, the opening of the electronic expansion valve is an initial opening; and/or

And in response to the measured liquid level in the oil separator not being lower than a second set liquid level, adjusting the opening of the electronic expansion valve to an initial opening.

When the operating frequency of the compressor 10 is controlled to be 80% -100% of the set frequency, the opening of the electronic expansion valve during refrigeration is the initial valve opening K=B; the opening degree of the electronic expansion valve is the opening degree K=C (full opening) of the initial valve during heating; the second set liquid level is 3/4 liquid level of the oil separator 9, when the oil level sensor detects that the actual measured liquid level exceeds the second set liquid level, the opening of the electronic expansion valve is adjusted to the corresponding opening value K=B when the operating frequency of the compressor 10 is full frequency in a refrigeration state; in the heating state, the electronic expansion valve opening is adjusted to an opening value k=c (full-open) corresponding to the case where the operating frequency of the compressor 10 is full.

The obtaining the initial opening of the electronic expansion valve comprises the following steps:

acquiring an operation mode of the air conditioner;

in response to the operation mode of the air conditioner being a cooling mode, the initial opening is equal to a first set opening; and/or

In response to the operating frequency of the air conditioner being in the heating mode, the initial opening is equal to a second set opening, wherein the second set opening is unequal to the first set opening.

Firstly, acquiring whether an operation mode of an air conditioner is refrigeration or heating, wherein the opening of an electronic expansion valve is refrigeration initial valve opening K=B when the air conditioner is refrigeration; when the air conditioner heats, the opening degree of the electronic expansion valve is heating initial valve opening degree K=C (full opening), and the refrigerating initial valve opening degree and the heating initial valve opening degree are not equal.

In the embodiment, the opening control and the stage time control of the electronic expansion valve are adopted, so that capillary blockage can be prevented, the operation reliability of the compressor is ensured, and the compressor is ensured to normally operate under various working conditions; the utility model can accurately control the oil return process and solve the problem of high and low pressure air leakage of the compressor 10 at low frequency; specifically, the control device further comprises a communication interface and a communication bus, and the processor, the memory and the communication interface complete communication with each other through the communication bus. The processor is used to provide computing and control capabilities. The memory includes a nonvolatile storage medium and an internal memory. The non-volatile storage medium stores an operating system and computer program instructions. The internal memory provides an environment for the execution of the operating system and computer program instructions in the non-volatile storage medium. The communication interface of the device is used for carrying out wired or wireless communication with an external terminal, and the wireless mode can be realized through WIFI, an operator network, NFC (near field communication) or other technologies.

By now it should be appreciated by those skilled in the art that while a number of exemplary embodiments of the utility model have been shown and described herein in detail, many other variations or modifications of the utility model consistent with the principles of the utility model may be directly ascertained or inferred from the present disclosure without departing from the spirit and scope of the utility model. Accordingly, the scope of the present utility model should be understood and deemed to cover all such other variations or modifications.

Claims (10)

1. An air conditioner, comprising:

a compressor forming a high pressure end and a low pressure end to drive a medium into and out of the low pressure end;

an oil separator forming at least an inlet connected to a high-pressure end of the compressor and a return port for returning the medium to the low-pressure end;

the first capillary tube is directly connected between the reflux port of the oil separator and the low-pressure end of the compressor;

and the second capillary tube is arranged in parallel with the first capillary tube, one end of the second capillary tube is connected with a reflux port of the oil separator, and the other end of the second capillary tube is connected with the low-pressure end of the compressor through an electric control valve.

2. The air conditioner of claim 1, wherein said second capillary tubes are provided in parallel with each other and said electric control valves are provided in series in one-to-one correspondence with each of said second capillary tubes.

3. The air conditioner of claim 2, wherein the second capillaries are three.

4. The air conditioner of claim 1, wherein a temperature sensor is further connected between the return port of the oil separator and the low pressure end of the compressor.

5. The air conditioner according to claim 4, wherein the temperature sensor is at an outlet of the first capillary tube and/or an outlet of the second capillary tube.

6. The air conditioner of claim 1, wherein the outlet of the first capillary tube and the outlet of the second capillary tube are converged and then connected to a temperature sensor to be connected to a low pressure end of the compressor via the temperature sensor.

7. The air conditioner of claim 4, wherein the outlet of the first capillary tube and the outlet of the electric control valve are connected to the temperature sensor after being converged to connect the low pressure end of the compressor via the temperature sensor.

8. An air conditioner according to claim 1, wherein the outlet of the first capillary tube and/or the outlet of the second capillary tube is connected between the compressor and the gas-liquid separator.

9. The air conditioner of claim 1, wherein said second capillary tube has at least two, and wherein at least two of said second capillary tubes have equal diameters of equal length.

10. The air conditioner of claim 9, wherein an oil level sensor is not provided in the oil separator.