CN110986431A

CN110986431A - Effective oil return control method and device and air conditioning unit

Info

Publication number: CN110986431A
Application number: CN201911421505.4A
Authority: CN
Inventors: 邹俊超; 余凯; 薛寒冬; 傅英胜; 张辉
Original assignee: Gree Electric Appliances Inc of Zhuhai
Current assignee: Gree Electric Appliances Inc of Zhuhai
Priority date: 2019-12-31
Filing date: 2019-12-31
Publication date: 2020-04-10
Anticipated expiration: 2039-12-31
Also published as: CN110986431B

Abstract

The invention discloses an effective oil return control method, an effective oil return control device and an air conditioning unit, wherein the method comprises the following steps: acquiring starting time and accumulated running time of a unit during starting; judging whether the relation between the starting time and a mute interval set by a user and the accumulated running time reach the standard oil return time or not; and executing a corresponding oil return control strategy according to the judgment result. The invention solves the problem that the multi-split oil return causes discomfort to users in the prior art, improves the comfort of the users, and simultaneously ensures the reliable operation of the unit.

Description

Effective oil return control method and device and air conditioning unit

Technical Field

The invention relates to the technical field of air conditioners, in particular to an effective oil return control method and device and an air conditioning unit.

Background

In actual engineering installation, a multi-split air conditioner is often provided with long connecting pipes or the fall of an indoor unit and an outdoor unit is high, and the indoor units of the multi-split air conditioner are started for a long time, so that oil return of the multi-split air conditioner system becomes a necessary and critical technology for ensuring long-term effective operation of the air conditioner.

However, the oil return of the system often causes great noise, and if the user is in a rest state for a special time, the user is uncomfortable. How to find a balance point between the multi-split air conditioner oil return and the use habit of a user becomes a very important mode for improving the comfort of products.

Aiming at the problem that the multi-split oil return causes discomfort to users in the related technology, no effective solution is provided at present.

Disclosure of Invention

The invention provides an effective oil return control method, an effective oil return control device and an air conditioning unit, and at least solves the problem that in the prior art, multi-split oil return causes discomfort to users.

To solve the technical problem, according to an aspect of an embodiment of the present invention, there is provided an oil return control method, including: acquiring starting time and accumulated running time of a unit during starting; judging whether the relation between the starting time and a mute interval set by a user and the accumulated running time reach the standard oil return time or not; and executing a corresponding oil return control strategy according to the judgment result.

Further, before the starting time and the accumulated running time of the unit during starting are obtained, a mute interval (α) and standard oil return time tau 0 set by a user are obtained, wherein the time is β - α and is not more than tau 0.

Further, the determining whether the relationship between the boot time and the silence interval set by the user and the accumulated running time reach the standard oil return time includes determining whether the boot time γ is less than the start time α of the silence interval, further determining whether the boot time γ is less than the end time β of the silence interval if the boot time γ is not less than the start time α of the silence interval, and determining whether the accumulated running time τ is less than the standard oil return time τ 0.

And further executing a corresponding oil return control strategy according to the judgment result, wherein the oil return control strategy comprises the steps of performing oil return operation according to the total running time delta when the unit is shut down when gamma is less than α and tau is less than tau 0, immediately performing conventional oil return operation when gamma is less than α and tau is more than or equal to tau 0, judging whether the running time of the unit reaches the standard oil return time tau 0 at β when gamma is not less than α and less than β and tau is less than tau 0, performing oil return operation according to the judgment result, and performing mute oil return operation when gamma is not less than α and less than β and tau is more than or equal to tau 0.

And further performing oil return operation according to the total running time delta when the unit is shut down, wherein the oil return operation comprises judging whether gamma + delta is smaller than α, further judging whether tau + delta is smaller than k1 tau 0 if gamma + delta is smaller than α, performing oil return operation according to the judgment result, further judging whether tau + (α - β) is smaller than k2 tau 0 if gamma + delta is larger than or equal to α, and performing oil return operation according to the judgment result, wherein k1 and k2 are coefficients, and k1 and k2 are smaller than 1.

Further, further determining whether τ + δ is smaller than k1 × τ 0, and performing an oil return operation according to the determination result, including: if tau + delta is less than k1 tau 0, controlling the unit to normally operate; and if the tau + delta is more than or equal to k1 tau 0, the control unit executes the conventional oil return operation before shutting down.

Further, whether tau + (α - β) is smaller than k2 x tau 0 or not is further judged, and oil return operation is carried out according to the judgment result, wherein the mute oil return operation is carried out after the unit running time reaches tau 0 if tau + (α - β) < k2 x tau 0, and the normal oil return operation is carried out before the unit normally runs until α time if tau + (α - β) gtoreqk 2 x tau 0.

Further, whether the running time of the unit reaches the standard oil return time tau 0 at β is judged, and oil return is carried out according to the judgment result, wherein the judgment includes that whether β -gamma is smaller than tau 0-tau, if β -gamma is smaller than tau 0-tau, whether the running time of the unit is larger than or equal to k3 x tau 0 at β is further judged, if yes, conventional oil return operation is carried out, and if β -gamma is larger than or equal to tau 0-tau, mute oil return operation is carried out after the running time of the unit reaches tau 0.

Further, the mute oil return operation comprises: controlling the electronic expansion valve of the indoor unit in the shutdown state to be gradually opened and the electronic expansion valve of the indoor unit in the startup state to be gradually closed; controlling the frequency of the compressor to be increased, and operating for a preset time after the preset oil return frequency is reached to finish oil return operation; after the oil return operation is finished, the compressor is controlled to reduce the frequency, and the electronic expansion valve of the indoor unit in the starting state is controlled to be gradually opened to a normal state.

According to another aspect of the embodiments of the present invention, there is provided an oil return control apparatus including: the acquisition module is used for acquiring the starting time and the accumulated running time of the unit during starting; the judging module is used for judging whether the relation between the starting time and a mute interval set by a user and the accumulated running time reach the standard oil return time or not; and the oil return module is used for executing a corresponding oil return control strategy according to the judgment result.

According to another aspect of the embodiment of the invention, an air conditioning unit is provided, which comprises the oil return control device.

According to a further aspect of embodiments of the present invention, there is provided a storage medium containing computer-executable instructions for performing the oil return control method as described above when executed by a computer processor.

In the present invention, an oil return control scheme is provided, which includes: and acquiring the starting time and the accumulated running time of the unit during starting, judging whether the relation between the starting time and a silence interval set by a user and the accumulated running time reach the standard oil return time, and executing a corresponding oil return control strategy according to a judgment result. Through the scheme, the influence of oil return on the silent section set by the user is reduced, the problem that the multi-split oil return causes discomfort of the user in the prior art is solved, the comfort of the user is improved, and meanwhile, the reliable operation of the unit is guaranteed.

Drawings

Fig. 1 is an alternative flow chart of an oil return control method according to an embodiment of the invention;

FIG. 2 is an alternative flow chart of a method of oil return control according to an embodiment of the present invention; and

fig. 3 is an alternative structural block diagram of the oil return control device according to the embodiment of the invention.

Detailed Description

Reference will now be made in detail to the exemplary embodiments, examples of which are illustrated in the accompanying drawings. When the following description refers to the accompanying drawings, like numbers in different drawings represent the same or similar elements unless otherwise indicated. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present invention. Rather, they are merely examples of apparatus and methods consistent with certain aspects of the invention, as detailed in the appended claims.

Example 1

In the preferred embodiment 1 of the present invention, an oil return control method is provided, where the control method can be directly applied to various intelligent sweeping robots, and can also be applied to other devices having partial functions of the sweeping robot, and when the control method is specifically implemented, the control method can be implemented by installing software, APP, or writing a program corresponding to a controller of the sweeping robot or other devices in the sweeping robot or other devices. In particular, fig. 1 shows an alternative flow chart of the method, which, as shown in fig. 1, comprises the following steps S102-S106:

s102: acquiring starting time and accumulated running time of a unit during starting;

s104: judging whether the relation between the starting time and a mute interval set by a user and the accumulated running time reach the standard oil return time or not;

s106: and executing a corresponding oil return control strategy according to the judgment result.

In the above embodiment, there is provided an oil return control scheme, including: and acquiring the starting time and the accumulated running time of the unit during starting, judging whether the relation between the starting time and a silence interval set by a user and the accumulated running time reach the standard oil return time, and executing a corresponding oil return control strategy according to a judgment result. Through the scheme, the influence of oil return on the silent section set by the user is reduced, the problem that the multi-split oil return causes discomfort of the user in the prior art is solved, the comfort of the user is improved, and meanwhile, the reliable operation of the unit is guaranteed.

In a preferred embodiment of the invention, before acquiring the starting time and the accumulated running time of the unit during starting, the method further comprises the step of acquiring a mute interval (α) and standard oil return time tau 0 set by a user, wherein the time is β - α and is not more than tau 0.

After a mute interval (α) set by a user and standard oil return time tau 0 are obtained, judging whether the relation between the startup time and the mute interval set by the user and whether the accumulated operation time reaches the standard oil return time or not, including judging whether the startup time gamma is less than the starting time of the mute interval α, further judging whether the startup time gamma is less than the ending time of the mute interval α if the startup time gamma is not less than the starting time of the mute interval β, and judging whether the accumulated operation time tau is less than the standard oil return time tau 0 or not, if the startup time is before the mute interval set by the user, judging whether the oil return operation is performed or not according to the accumulated total operation time tau of the unit when the unit is shutdown, determining the accumulated total operation time according to the sum of the accumulated operation time tau when the startup time is greater than the mute interval set by the user, if the startup time is within the mute interval set by the user, judging whether the oil return operation is performed according to the accumulated operation time tau and whether the operation time of the unit reaches the standard oil return time tau 0 at β, and the oil return operation is not influenced by the mute interval set by the user.

Based on the above, executing a corresponding oil return control strategy according to a judgment result, including performing oil return operation according to the total running time delta when the unit is shut down when gamma is less than α and tau is less than tau 0, immediately performing conventional oil return operation when gamma is less than α and tau is greater than or equal to tau 0, judging whether the running time of the unit reaches the standard oil return time tau 0 at β when gamma is less than or equal to α and less than β and tau is less than tau 0, performing oil return operation according to the judgment result, performing silent oil return operation when gamma is less than or equal to α and less than β and tau is greater than or equal to tau 0, indicating that the unit reaches a state of necessary oil return when gamma is less than α and tau is greater than or equal to tau 0, and performing the conventional oil return operation immediately, but when gamma is less than or equal to α and less than β and tau is greater than or equal to tau 0, the unit reaches the state of necessary oil return operation, but is positioned in the silent interval set by the user, and performing the silent oil return operation to reduce disturbance to the user as much as possible, thereby reducing the reliable operation of the unit and improving the comfort of the user.

In the above embodiment, the oil return operation is performed according to the total time length δ of the unit during the operation when the unit is shut down, and includes determining whether γ + δ is less than α, further determining whether τ + δ is less than k1 τ 0 and performing the oil return operation according to the determination result if γ + δ is less than α, further determining whether τ + (α - β) is less than k2 τ 0 and performing the oil return operation according to the determination result if γ + δ is greater than or equal to α, where k1 and k2 are coefficients and k1 and k2 are both less than 1, optionally, k1 and k2 are 2/3 and k1 and k2 are set in consideration of the reliability of the operation of the unit, and the oil return operation is performed in advance on the premise that a silent interval set by a user is not disturbed, so as to further improve the reliability of the unit.

Wherein, further judge whether τ + δ is less than k1 τ 0, and carry out the oil return operation according to the judged result, including: if tau + delta is less than k1 tau 0, the unit is controlled to normally operate, and oil return is not needed at the moment; if tau + delta is larger than or equal to k1 tau 0, the unit is controlled to execute conventional oil return operation before shutdown, and the unit can be ensured to directly run when the unit is started next time.

In addition, whether tau + (α - β) is smaller than k2 x tau 0 is further judged, and oil return operation is carried out according to the judgment result, wherein the oil return operation is carried out in a mute mode after the unit running time reaches tau 0 if tau + (α - β) < k2 x tau 0, and the oil return operation is carried out normally until α time when the unit runs normally if tau + (α - β) gtoreqk 2 x tau 0.

In another preferred embodiment of the invention, whether the running time of the unit reaches the standard oil return time tau 0 at β is judged, and oil return is carried out according to the judgment result, which comprises judging whether β -gamma is smaller than tau 0-tau, further judging whether the running time of the unit is larger than or equal to k3 tau 0 at β moment if β -gamma is smaller than tau 0-tau, and carrying out conventional oil return operation if the running time of the unit is larger than or equal to k3 tau 0 at β moment, wherein k3 is a coefficient and k3 is smaller than 1, and the same as the setting of k1 and k2, the reliability of the unit running is considered, oil return is carried out in advance on the premise of not disturbing a silent interval set by a user, and the reliability of the unit is further improved, and if β -gamma is larger than or equal to tau 0-tau 0, the silent oil return operation is carried out after.

In the present invention, a silent oil return operation is provided to minimize the disturbance to the user in the event that oil has to be returned. The mute oil return operation comprises the following steps: controlling the electronic expansion valve of the indoor unit in the shutdown state in the multi-split air conditioner to be gradually opened and the electronic expansion valve of the indoor unit in the startup state to be gradually closed; controlling the frequency of the compressor to be increased, and operating for a preset time after the preset oil return frequency is reached to finish oil return operation; after the oil return operation is finished, the compressor is controlled to reduce the frequency, and the electronic expansion valve of the indoor unit in the starting state is controlled to be gradually opened to a normal state.

In preferred embodiment 1 of the present invention, another oil return control method is further provided, specifically, fig. 2 shows an optional flowchart of the method, and as shown in fig. 2, the method includes the following steps S202 to S214: :

s202, a user can select an oil return mute time zone [ α ] according to actual conditions, wherein the oil return time zone [ β - α ] is required to be equal to or less than [ tau ] 0, the [ tau ] 0 is standard oil return time, and in order to ensure that the compressor has enough refrigeration oil, the multi-split air conditioner is provided with an oil return mechanism matched with the compressor and a pipeline system, namely when the compressor operates in an accumulated mode for [ tau ] 0 hours at a frequency lower than [ psi ] Hz, the system enters oil return operation.

Assume that the user turns on at γ and the compressor runs at t hours below Ψ Hz at turn on.

S204, judging whether gamma is smaller than α;

s206: judging whether tau is smaller than tau 0;

s208, when gamma is less than α and tau is less than tau 0, judging according to the running time delta during shutdown, wherein the running time delta of the unit is the running time delta from the time when a user starts the unit at the gamma moment to the time when the unit is shut down;

specifically, the method comprises the following steps:

if gamma + delta is less than α, namely the shutdown time of the unit is in a mute interval, and tau + delta is less than (2/3) tau 0, the unit normally operates;

if gamma + delta is less than α and tau + delta is more than or equal to (2/3) × tau 0, the unit is operated according to the conventional oil return, if the shutdown instruction is issued, the accumulated oil return time tau 0 is not reached, the unit executes the oil return action before the shutdown when the user executes the shutdown instruction;

if gamma + delta is not less than α and tau + (α - β) < (2/3) × 0, executing mute oil return operation after normal operation is carried out until tau is not less than tau 0;

if gamma + delta is larger than or equal to α, and tau + (α - β) is larger than or equal to (2/3) tau 0, the unit normally operates, and when the time reaches α, a conventional oil return action is executed.

S210, when gamma is less than α and tau is more than or equal to tau 0, the system executes a conventional oil return action;

s212: judging whether tau is smaller than tau 0;

s214, when gamma is larger than or equal to α and tau is smaller than tau 0, judging according to the relation between (β -gamma) and (tau 0-tau);

s216, when gamma is more than or equal to α, if gamma is more than or equal to α and less than β and tau is more than or equal to tau 0, the system executes a mute oil return action, and the accumulated time of the low-frequency operation at the moment is determined to be (1/3) × tau 0;

specifically, the method comprises the following steps:

if β -gamma is less than tau 0-tau, the unit is installed to operate in a normal mode, and when the unit operates until gamma is more than β, if tau is more than or equal to (9/10) tau 0, the unit executes oil return action, and the oil return flag bit is cleared;

if β -gamma is equal to or more than tau 0-tau, then normal operation is carried out until tau is equal to or more than tau 0, and then the action of step 4 is executed.

Preferably, the control mode of the mute oil return action is as follows:

in the refrigeration mode, the electronic expansion valve of the shutdown indoor unit is gradually opened, the electronic expansion valve of the startup indoor unit is gradually closed to 0 step, then the frequency of the compressor is slowly increased, the compressor runs for a period of time after reaching the expected oil return frequency, then the oil return action is finished, the frequency of the compressor is gradually reduced, the electronic expansion valve of the shutdown indoor unit is gradually opened, and the step number of the electronic expansion valve of the shutdown indoor unit gradually returns to the normal control.

In the heating mode, the oil return is not reversed. The electronic expansion valve of the shutdown indoor unit is gradually opened, the electronic expansion valve of the startup indoor unit is gradually closed to 0 step, then the frequency of the compressor is slowly increased, the compressor runs for a period of time after reaching the expected oil return frequency, then the oil return action is finished, the frequency of the compressor is gradually decreased slowly, the electronic expansion valve of the shutdown indoor unit is gradually opened, and the step number of the electronic expansion valve of the shutdown indoor unit gradually returns to the normal control.

Compared with a mode of independently returning oil according to the running time, the method has the advantages that the comfort of a user is improved on the premise of ensuring the reliability of the unit.

Example 2

Based on the oil return control method provided in the foregoing embodiment 1, in a preferred embodiment 2 of the present invention, an oil return control device is further provided, specifically, fig. 3 shows an optional structural block diagram of the device, and as shown in fig. 3, the device includes:

an obtaining module 302, configured to obtain a boot time and an accumulated running time of the unit during boot;

a judging module 304, connected to the obtaining module 302, for judging whether the relation between the boot-up time and the silence interval set by the user and the accumulated running time reach the standard oil return time;

and the oil return module 306 is connected to the judging module 304 and is configured to execute a corresponding oil return control strategy according to the judgment result.

In a preferred embodiment of the present invention, the apparatus further includes a silence interval obtaining module, configured to obtain a silence interval [ α ] and a standard oil return time τ 0, which are set by a user, before obtaining the startup time and the accumulated running time of the unit at startup, where τ 0 is not less than β - α.

The determining module 304 further includes a first determining unit for determining whether the startup time γ is less than the start time α of the silence interval, and further determining whether the startup time γ is less than the end time β of the silence interval if the startup time γ is not less than the start time α of the silence interval, and a second determining unit for determining whether the accumulated running time τ is less than the standard oil return time τ 0.

Preferably, the oil return module 306 includes a first oil return unit configured to perform oil return operation according to the total time length δ of the unit during shutdown when γ is less than α and τ is less than τ 0, a second oil return unit configured to perform conventional oil return operation immediately when γ is less than α and τ is greater than or equal to τ 0, a third oil return unit configured to determine whether the operation time of the unit reaches the standard oil return time τ 0 at β when γ is less than or equal to α and less than β and τ is less than τ 0, and perform oil return operation according to the determination result, and a fourth oil return unit configured to perform silent oil return operation when γ is less than β and τ is greater than or equal to α and τ 0.

The first oil return unit comprises a first judgment subunit, a second judgment subunit and a third judgment subunit, wherein the first judgment subunit is used for judging whether gamma + delta is smaller than α or not, the second judgment subunit is used for further judging whether tau + delta is smaller than k1 tau 0 or not and carrying out oil return operation according to the judgment result if gamma + delta is smaller than α, the third judgment subunit is used for further judging whether tau + (α - β) is smaller than k2 tau 0 or not and carrying out oil return operation according to the judgment result if gamma + delta is larger than or equal to α, k1 and k2 are coefficients, and k1 and k2 are smaller than 1.

Further, the second judging subunit specifically includes: if tau + delta is less than k1 tau 0, controlling the unit to normally operate; and if the tau + delta is more than or equal to k1 tau 0, the control unit executes the conventional oil return operation before shutting down.

Further, the third judgment subunit comprises a mute oil return operation after the running time of the unit reaches tau 0 if tau + (α - β) < k2 tau 0, and a normal oil return operation before the normal running time of the unit reaches α if tau + (α - β) ≧ k2 tau 0.

Optionally, the third oil return unit comprises a fourth judgment subunit for judging whether β -gamma is smaller than tau 0-tau, a fifth judgment subunit for further judging whether the running time of the unit at β is greater than or equal to k3 x tau 0 if β -gamma is smaller than tau 0-tau, and if so, performing a normal oil return operation, and a mute oil return subunit for performing a mute oil return operation after the running time of the unit reaches tau 0 if β -gamma is greater than or equal to tau 0-tau.

Preferably, the silent oil return operation comprises: controlling the electronic expansion valve of the indoor unit in the shutdown state to be gradually opened and the electronic expansion valve of the indoor unit in the startup state to be gradually closed; controlling the frequency of the compressor to be increased, and operating for a preset time after the preset oil return frequency is reached to finish oil return operation; after the oil return operation is finished, the compressor is controlled to reduce the frequency, and the electronic expansion valve of the indoor unit in the starting state is controlled to be gradually opened to a normal state.

With regard to the apparatus in the above embodiments, the specific manner in which each unit and each module performs operations has been described in detail in the embodiments related to the method, and will not be described in detail herein.

Example 3

Based on the oil return control device provided in the above embodiment 2, in a preferred embodiment 3 of the present invention, an air conditioning unit is further provided, which includes the oil return control device as described above.

Example 4

Based on the oil return control method provided in the above embodiment 1, in a preferred embodiment 4 of the present invention, there is also provided a storage medium containing computer executable instructions, which when executed by a computer processor, are used to execute the oil return control method as described above.

Other embodiments of the invention will be apparent to those skilled in the art from consideration of the specification and practice of the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of the invention following, in general, the principles of the invention and including such departures from the present disclosure as come within known or customary practice within the art to which the invention pertains. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the invention being indicated by the following claims.

It will be understood that the invention is not limited to the precise arrangements described above and shown in the drawings and that various modifications and changes may be made without departing from the scope thereof. The scope of the invention is limited only by the appended claims.

Claims

1. An oil return control method is characterized by comprising the following steps:

acquiring starting time and accumulated running time of a unit during starting;

judging whether the relation between the starting time and a mute interval set by a user and the accumulated running time reach standard oil return time or not;

and executing a corresponding oil return control strategy according to the judgment result.

2. The method of claim 1, further comprising, before obtaining the boot time and the accumulated running time of the unit at boot time:

and acquiring the mute interval (α) set by a user and the standard oil return time tau 0, wherein the tau 0 is not less than β - α.

3. The method of claim 2, wherein determining whether the relationship between the boot-up time and the silence interval set by the user and the accumulated running time reach a standard oil return time comprises:

determining whether the on-time gamma is less than the start time α of the silence interval, and if the on-time gamma is not less than the start time α of the silence interval, further determining whether the on-time gamma is less than the end time β of the silence interval, and

and judging whether the accumulated running time tau is less than the standard oil return time tau 0 or not.

4. The method of claim 3, wherein executing the corresponding oil return control strategy according to the determination result comprises:

when gamma is less than α and tau is less than tau 0, performing oil return operation according to the total running time delta when the unit is shut down;

when gamma is less than α and tau is more than or equal to tau 0, immediately carrying out conventional oil return operation;

when gamma is not less than α and is less than β and tau is less than tau 0, judging whether the running time of the unit reaches the standard oil return time tau 0 at the time of β, and performing oil return operation according to the judgment result;

and when gamma is more than or equal to α and less than β and tau is more than or equal to tau 0, carrying out mute oil return operation.

5. The method according to claim 4, wherein the oil return operation is performed according to the total running time length delta when the unit is shut down, and comprises the following steps:

judging whether the gamma + delta is smaller than α;

if gamma + delta is less than α, further judging whether tau + delta is less than k1 tau 0, and performing oil return operation according to the judgment result;

if gamma + delta is not less than α, further judging whether tau + (α - β) is less than k2 tau 0, and performing oil return operation according to the judgment result;

wherein k1 and k2 are coefficients, and k1 and k2 are both less than 1.

6. The method of claim 5, further determining whether τ + δ is less than k1 τ 0, and performing an oil return operation according to the determination result, comprising:

if tau + delta is less than k1 tau 0, controlling the unit to normally operate;

and if the tau + delta is more than or equal to k1 tau 0, controlling the unit to execute a conventional oil return operation before shutdown.

7. The method of claim 5, further determining whether τ + (α - β) is less than k2 τ 0, and performing an oil return operation according to the determination result, comprising:

if tau + (α - β) < k2 tau 0, performing mute oil return operation after the running time of the unit reaches tau 0;

if tau + (α - β) ≧ k2 tau 0, normal oil return operation is performed before the unit normally operates until α.

8. The method of claim 4, wherein the step of determining whether the running time of the unit reaches the standard oil return time τ 0 at time β and performing an oil return operation according to the determination result comprises:

judging β -gamma is less than tau 0-tau;

if β -gamma is less than tau 0-tau, further judging whether the running time of the unit is more than or equal to k3 tau 0 at the time of β, and if so, performing conventional oil return operation, wherein k3 is a coefficient, and k3 is less than 1;

and if β -gamma is larger than or equal to tau 0-tau, performing mute oil return operation after the running time of the unit reaches tau 0.

9. The method of claim 4, wherein the unit is a multi-split air conditioner; the mute oil return operation comprises the following steps:

controlling the electronic expansion valve of the indoor unit in the shutdown state to be gradually opened and the electronic expansion valve of the indoor unit in the startup state to be gradually closed;

controlling the frequency of the compressor to be increased, and operating for a preset time after the preset oil return frequency is reached to finish oil return operation;

and after the oil return operation is finished, controlling the compressor to reduce the frequency, and controlling the electronic expansion valve of the indoor unit in the starting state to be gradually opened to a normal state.

10. An oil return control device, characterized by comprising:

the acquisition module is used for acquiring the starting time and the accumulated running time of the unit during starting;

the judging module is used for judging whether the relation between the starting time and a mute interval set by a user and the accumulated running time reach standard oil return time or not;

and the oil return module is used for executing a corresponding oil return control strategy according to the judgment result.

11. An air conditioning assembly characterized by comprising the oil return control device according to claim 10.

12. A storage medium containing computer-executable instructions for performing the oil return control method of any one of claims 1 to 9 when executed by a computer processor.