Oil return control method and oil return control device of air conditioner and air conditioner

Abstract

The invention provides an oil return control method and device of an air conditioner and the air conditioner. An oil return pipe connected with an air return port of the compressor is arranged at the bottom of a gas-liquid separator in the air conditioner outdoor unit, and an oil return control valve is arranged on the oil return pipe. The oil return control method of the air conditioner comprises the steps that the current working stage of the air conditioner and exhaust parameters of a compressor are obtained; and the opening degree of the oil return control valve is controlled and adjusted according to the current working stage and the exhaust parameters. According to the oil return control method and device of the air conditioner and the air conditioner, on one hand, recycling of refrigerant oil deposited at the bottom of a gas-liquid separator is fully guaranteed, the requirement for the oil return amount of a compressor is met, normal work of a system is guaranteed, on the other hand, the phenomenon that liquid refrigerant flows back to an air suction opening of the compressor during oil return is avoided, and the service life of the air conditioner is prolonged. And the refrigerant liquid return risk is eliminated, liquid impact faults of the compressor are avoided, and the service life of the compressor is guaranteed.

Description

Technical Field

[0001] The present invention relates to the technical field of electrical appliances, and in particular to an oil return control method and an oil return control device of an air conditioner and an air conditioner. Background Art

[0002] In the related technology, currently, the outdoor unit of the commercial air conditioner is equipped with an oil separator at the air outlet of the compressor, so as to separate and control the oil return of the refrigeration oil brought out when the compressor is exhausted, thereby ensuring that the refrigeration oil can smoothly return to the compressor, so as to ensure that the compressor is not short of oil and ensure the reliability of lubrication inside the compressor. In addition, a gas-liquid separator is provided at the return air end of the compressor to ensure that the refrigerant returning to the compressor enters the compressor in gaseous form, preventing liquid refrigerant from entering the compressor and causing liquid hammer.

[0003] At the same time, due to the mutual solubility of refrigerant and refrigeration oil, the separation efficiency of the oil separator cannot reach 100%, and some refrigeration oil will still circulate to other parts of the system with the refrigerant. Among them, the deposition of refrigerant in the gas-liquid separator will cause the liquid refrigerant to be stored in the gas. As the liquid refrigerant stands for an increasing amount of time, the refrigeration oil in the refrigerant will gradually separate from the liquid refrigerant and stratify. Because the density of refrigeration oil is greater than that of liquid refrigerant, some refrigeration oil will be deposited at the bottom of the gas-liquid separator. Over time, the amount of refrigeration oil deposited will increase, which is not conducive to the operation of the system.

[0004] In order to ensure that the refrigeration oil can be fully recycled, the existing technology generally adds an oil return pipeline to the compressor return pipe at the bottom of the gas-liquid separator. However, the above structure has a certain risk of refrigerant liquid return. When there is no refrigeration oil at the bottom or the amount of refrigeration oil is small, the liquid refrigerant will enter the return pipe through the oil return pipeline, causing a certain risk of liquid hammer. Therefore, a certain control solution is needed to ensure that the bottom oil return will not cause liquid hammer. Summary of the invention

[0005] The present invention provides an oil return control method, an oil return control device and an air conditioner for an air conditioner, so as to solve the defects in the prior art and achieve the following technical effects: on the one hand, it fully ensures the recovery and reuse of the refrigeration oil deposited at the bottom of the gas-liquid separator, meets the oil return volume demand of the compressor, and ensures the normal operation of the system; on the other hand, it avoids the phenomenon of liquid refrigerant flowing back to the suction port of the compressor during oil return, eliminates the risk of refrigerant liquid return, avoids the occurrence of compressor liquid hammer failure, and ensures the service life of the compressor.

[0006] According to the oil return control method of the air conditioner in the first embodiment of the present invention, an oil return pipe connected to the return air port of the compressor is provided at the bottom of the gas-liquid separator in the outdoor unit of the air conditioner, and an oil return control valve is provided on the oil return pipe; the method comprises:

[0007] Obtaining the current working stage of the air conditioner and exhaust parameters of the compressor;

[0008] The opening of the oil return control valve is controlled and adjusted according to the current working stage and the exhaust parameter.

[0009] According to one embodiment of the present invention, the current working stage includes a preliminary startup stage and a normal operation stage;

[0010] Then the step of controlling and adjusting the opening of the oil return control valve according to the current working stage and the exhaust parameter specifically includes:

[0011] In the case where the current working stage is a preliminary startup stage, obtaining the outdoor ambient temperature, and controlling and adjusting the opening of the oil return control valve according to the outdoor ambient temperature and the first exhaust parameter of the compressor in the preliminary startup stage;

[0012] In a case where the current working stage is a normal operation stage, the opening of the oil return control valve is controlled and adjusted according to the second exhaust parameter of the compressor in the normal operation stage.

[0013] According to an embodiment of the present invention, the first exhaust parameter includes the exhaust temperature of the compressor, and the second exhaust parameter includes the exhaust superheat of the compressor.

[0014] According to one embodiment of the present invention, the step of controlling and adjusting the opening of the oil return control valve according to the outdoor ambient temperature and the first exhaust parameter of the compressor in the initial startup stage specifically includes:

[0015] Where the current working phase is the initial start-up phase;

[0016] Determining that the outdoor ambient temperature is less than or equal to the set ambient temperature, or the exhaust temperature is less than or equal to the set exhaust temperature, then controlling the oil return control valve to remain in a closed state;

[0017] Alternatively, if it is determined that the outdoor ambient temperature is greater than the set ambient temperature and the exhaust temperature is greater than the set exhaust temperature, the oil return control valve is controlled to perform intermittent on-off control.

[0018] According to one embodiment of the present invention, the step of controlling the oil return control valve to perform intermittent on-off control specifically includes:

[0019] Controlling the oil return control valve to first be continuously opened for a first set time and then continuously closed for a second set time, and then cyclically performing the above operation on the oil return control valve until the current working stage enters the normal operation stage;

[0020] The first set duration is shorter than the second set duration.

[0021] According to one embodiment of the present invention, when the current working stage is a normal operation stage, the step of controlling and adjusting the opening of the oil return control valve according to the second exhaust parameter of the compressor in the normal operation stage specifically includes:

[0022] When the current working stage is a normal operation stage, controlling the liquid return control valve to remain in an open state;

[0023] Whenever the oil return control valve is opened for a third set time, the air conditioner is controlled to enter a refrigerant return liquid determination mode and continue for a fourth set time, and after the fourth set time, the oil return control valve is controlled to be reset to an open state, and this step is then executed repeatedly;

[0024] Wherein, in the refrigerant liquid return judgment mode, the opening of the oil return control valve is adjusted according to the exhaust gas superheat of the compressor.

[0025] According to an embodiment of the present invention, the step of adjusting the opening of the oil return control valve according to the exhaust gas superheat of the compressor in the refrigerant liquid return judgment mode specifically includes:

[0026] According to the exhaust gas superheat of the compressor being less than or equal to the first exhaust gas superheat, the oil return control valve is controlled to be continuously closed for the fourth set time period, and after the fourth set time period ends, the oil return control valve is controlled to continue to remain in an open state.

[0027] According to an embodiment of the present invention, the step of adjusting the opening of the oil return control valve according to the exhaust gas superheat of the compressor in the refrigerant liquid return judgment mode specifically includes:

[0028] Determining that the exhaust superheat of the compressor is greater than the second exhaust superheat, and the decreasing speed of the exhaust superheat is greater than or equal to the set decreasing speed, and the exhaust superheat decreases by the set decreasing value within the fifth set time, or determining that the exhaust superheat of the compressor is greater than the first exhaust superheat and less than or equal to the third exhaust superheat, then controlling the oil return control valve to first be continuously opened for the first set time and then continuously closed for the second set time, and then cyclically performing the above operation on the oil return control valve until the fourth set time ends;

[0029] The first exhaust superheat is smaller than the second exhaust superheat, and the second exhaust superheat is smaller than the third exhaust superheat.

[0030] According to the oil return control device of the air conditioner in the second embodiment of the present invention, an oil return pipe connected to the return air port of the compressor is provided at the bottom of the gas-liquid separator in the outdoor unit of the air conditioner, and an oil return control valve is provided on the oil return pipe; the device comprises:

[0031] An acquisition module, used to acquire the current working stage of the air conditioner and the exhaust parameters of the compressor;

[0032] A control module is used to control and adjust the opening of the oil return control valve according to the current working stage and the exhaust parameter.

[0033] An air conditioner according to a third aspect of the present invention includes:

[0034] An indoor heat exchanger, an outdoor heat exchanger, a four-way valve, an electronic expansion valve, a compressor and a gas-liquid separator connected by a refrigerant pipeline, wherein an oil return pipe connected to the air return port of the compressor is provided at the bottom of the gas-liquid separator, and an oil return control valve is provided on the oil return pipe;

[0035] A memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the program, the oil return control method for the air conditioner as described in the embodiment of the first aspect of the present invention is implemented.

[0036] According to one embodiment of the present invention, at least two oil return control valves are provided on the oil return pipe, and all the oil return control valves are connected in parallel.

[0037] The present invention provides an oil return control method for an air conditioner, which obtains the current working stage of the air conditioner and the exhaust parameters of the compressor, and further executes different control logics on the opening of the return oil control valve according to the current working stage of the air conditioner. In the process of controlling the return oil control valve, the influence of the exhaust parameters of the compressor on the return oil is fully considered and analyzed, thereby realizing precise adjustment of the opening of the return oil control valve. In this way, on the one hand, the recovery and reuse of the refrigeration oil deposited at the bottom of the gas-liquid separator is fully guaranteed, the oil return volume demand of the compressor is met, and the normal operation of the system is guaranteed. On the other hand, the phenomenon of liquid refrigerant flowing back to the suction port of the compressor during oil return is avoided, the risk of refrigerant liquid return is eliminated, the occurrence of compressor liquid hammer failure is avoided, and the service life of the compressor is guaranteed. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0039] Figure 1 It is a flow chart of the oil return control method of the air conditioner provided by the present invention;

[0040] Figure 2 It is a structural schematic diagram of the oil return control device of the air conditioner provided by the present invention;

[0041] Figure 3 It is a structural schematic diagram of the air conditioner provided by the present invention;

[0042] Figure 4 It is a structural schematic diagram of the electronic device provided by the present invention.

[0043] Reference numerals:

[0044] 1. Compressor; 2. Gas-liquid separator; 21. Oil return pipe; 22. Oil return control valve; 3. Oil separator; 4. Four-way valve; 5. Indoor heat exchanger; 6. Outdoor heat exchanger; 7. Electronic expansion valve. DETAILED DESCRIPTION

[0045] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0046] In the description of the embodiments of the present invention, it should be noted that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as limitations on the embodiments of the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0047] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the embodiment of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0048] The oil return control method, oil return control device and air conditioner of the air conditioner proposed by the present invention are described below with reference to the accompanying drawings. Among them, before the embodiment of the present invention is described in detail, the entire application scenario is first described. The oil return control method, oil return control device, electronic device and computer-readable storage medium of the air conditioner of the embodiment of the present invention can be applied to the air conditioner locally, and can also be applied to the cloud platform in the Internet field, or other types of cloud platforms in the Internet field, or can also be applied to third-party devices. Among them, the third-party device may include many different types such as mobile phones, tablet computers, notebooks, car computers and other smart terminals.

[0049] The following description will only be made by taking the oil return control method applicable to air conditioners as an example. It should be understood that the oil return control method of the embodiment of the present invention can also be applied to cloud platforms and third-party devices.

[0050] It should also be noted that the oil return control method for an air conditioner proposed in the present invention is universal, that is, the method is applicable to cooling or heating the air conditioner in a low-temperature environment or a high-temperature environment.

[0051] like Figure 1 As shown, according to the oil return control method of the air conditioner in the first embodiment of the present invention, the bottom of the gas-liquid separator 2 in the air conditioner outdoor unit is provided with an oil return pipe 21 connected to the return air port of the compressor 1, and the oil return pipe 21 is provided with an oil return control valve 22. The oil return control method of the air conditioner includes:

[0052] Step S1, obtaining the current working stage of the air conditioner and the exhaust parameters of the compressor 1;

[0053] Step S2, controlling and adjusting the opening of the oil return control valve 22 according to the current working stage and exhaust parameters.

[0054] According to the oil return control method of the air conditioner according to the embodiment of the present invention, while ensuring that the bottom of the gas-liquid separator 2 of the air conditioner outdoor unit completely returns the oil, it can prevent the liquid refrigerant inside the gas-liquid separator 2 from flowing back into the compressor 1 to cause liquid hammer. Specifically, the specific working process and working principle of this control method are as follows:

[0055] First, after determining that the air conditioner is powered on, the controller obtains the current working stage of the air conditioner and obtains the exhaust parameters of the compressor 1 in the current working stage. After that, after obtaining the above-mentioned current working stage and exhaust parameters, the controller further executes different control logics on the opening of the return oil control valve 22 according to the current working stage of the air conditioner, and fully considers and analyzes the influence of the exhaust parameters of the compressor 1 on the return oil in the process of controlling the return oil control valve 22, thereby realizing precise adjustment of the opening of the return oil control valve 22.

[0056] It should be noted that the above-mentioned "current working stage" refers to the stage in which the air conditioner is currently working. Specifically, the current working stage includes the initial startup stage and the normal operation stage. The initial startup stage refers to the pre-operation preparation stage with the compressor 1 just being turned on as the starting point and with the compressor 1 frequency increasing to the target operating frequency as the end point. The normal operation stage refers to the formal operation stage in which the air conditioner operates normally in cooling mode, heating mode or other modes after the compressor 1 reaches the target operating frequency.

[0057] Furthermore, it should be noted that the above-mentioned "exhaust parameters" refer to various parameter information of parameters such as temperature or pressure at the exhaust end of the compressor 1. Specifically, the exhaust parameters include but are not limited to parameters such as the exhaust temperature of the compressor 1, the exhaust pressure of the compressor 1 and the exhaust superheat, and the types and quantities of exhaust parameters in the judgment factors required to adjust the return oil control valve 22 may be different in different current working stages.

[0058] It can be understood that in the above-mentioned oil return control method, the amount of oil and the amount of refrigerant in the gas-liquid separator 2 are generally different under different current working conditions. For example, in the initial startup stage, the frequency and power of the compressor 1 of the air conditioner are relatively low, so the amount of oil in the gas-liquid separator 2 is relatively small at this time, and the compressor 1 also has a high requirement for the amount of oil return, so that the oil return control valve 22 can be normally closed or occasionally opened in the initial startup stage; for another example, in the normal operation stage, the air conditioner operates normally, so the frequency and power of the compressor 1 are relatively high, so the amount of deposited oil at the bottom of the gas-liquid separator 2 will increase with the progress of cooling / heating, and the compressor 1 also has a high requirement for the amount of oil return, so that in the normal operation mode, the oil return control valve 22 needs to be kept normally open, unless in some special situations that may cause liquid hammer, the oil return control valve 22 is closed, so that the refrigeration oil can be fully recycled and the risk of refrigerant liquid return can be avoided to a certain extent.

[0059] In addition, the exhaust parameters of compressor 1 can also reflect the current oil return demand of compressor 1. By comprehensively considering the influence of the exhaust parameters at different current working stages to adjust the opening of the return oil control valve 22, it can be ensured that the oil return demand of compressor 1 is met and the normal operation of the air conditioner is guaranteed.

[0060] In the related technology, currently, the outdoor unit of the commercial air conditioner is equipped with an oil separator at the air outlet of the compressor, so as to separate and control the oil return of the refrigeration oil brought out when the compressor is exhausted, thereby ensuring that the refrigeration oil can smoothly return to the compressor, so as to ensure that the compressor is not short of oil and ensure the reliability of lubrication inside the compressor. In addition, a gas-liquid separator is provided at the return air end of the compressor to ensure that the refrigerant returning to the compressor enters the compressor in gaseous form, preventing liquid refrigerant from entering the compressor and causing liquid hammer.

[0061] At the same time, due to the mutual solubility of refrigerant and refrigeration oil, the separation efficiency of the oil separator cannot reach 100%, and some refrigeration oil will still circulate to other parts of the system with the refrigerant. Among them, the deposition of refrigerant in the gas-liquid separator will cause the liquid refrigerant to be stored in the gas. As the liquid refrigerant stands for an increasing amount of time, the refrigeration oil in the refrigerant will gradually separate from the liquid refrigerant and stratify. Because the density of refrigeration oil is greater than that of liquid refrigerant, some refrigeration oil will be deposited at the bottom of the gas-liquid separator. Over time, the amount of refrigeration oil deposited will increase, which is not conducive to the operation of the system.

[0062] In order to ensure that the refrigeration oil can be fully recycled, the prior art generally adds an oil return pipeline leading to the compressor return pipe at the bottom of the gas-liquid separator 2. However, the above structure has a certain risk of refrigerant liquid return. When there is no refrigeration oil at the bottom or the amount of refrigeration oil is small, the liquid refrigerant will enter the return pipe through the oil return pipeline, causing a certain risk of liquid hammer. Therefore, a certain control scheme is required to ensure that the bottom oil return will not cause liquid hammer.

[0063] In summary, in order to solve the technical defects existing in the above-mentioned related technologies, the present invention provides an oil return control method for an air conditioner, which obtains the current working stage of the air conditioner and the exhaust parameters of the compressor 1, and further executes different control logics on the opening of the return oil control valve 22 according to the current working stage of the air conditioner. In the process of controlling the return oil control valve 22, the influence of the exhaust parameters of the compressor 1 on the return oil is fully considered and analyzed, thereby realizing precise adjustment of the opening of the return oil control valve 22. In this way, on the one hand, the recovery and reuse of the refrigerant oil deposited at the bottom of the gas-liquid separator 2 is fully guaranteed, the oil return volume demand of the compressor 1 is met, and the normal operation of the system is ensured. On the other hand, the phenomenon of liquid refrigerant reflux to the suction port of the compressor 1 during oil return is avoided, the risk of refrigerant liquid return is eliminated, the occurrence of liquid hammer failure of the compressor 1 is avoided, and the service life of the compressor 1 is ensured.

[0064] According to some embodiments of the present invention, the current working phase includes a preliminary startup phase and a normal operation phase.

[0065] The steps of controlling the opening of the oil return control valve 22 according to the current working stage and the exhaust parameters specifically include:

[0066] When the current working stage is the preliminary startup stage, the outdoor ambient temperature is obtained, and the opening of the oil return control valve 22 is controlled and adjusted according to the outdoor ambient temperature and the first exhaust parameter of the compressor 1 in the preliminary startup stage;

[0067] When the current working stage is the normal operation stage, the opening of the oil return control valve 22 is controlled and adjusted according to the second exhaust parameter of the compressor 1 in the normal operation stage.

[0068] It can be understood that during the initial startup stage, the outdoor ambient temperature has a great influence on the amount of oil deposited in the gas-liquid separator 2, etc. Therefore, the adjustment operation of the return oil control valve 22 during the initial startup stage needs to take into account the impact of the outdoor environment thereon, so as to ensure the accuracy of the opening adjustment of the return oil control valve 22.

[0069] According to some embodiments of the present invention, the first exhaust parameter includes the exhaust temperature of the compressor 1 , and the second exhaust parameter includes the exhaust superheat of the compressor 1 .

[0070] According to some embodiments of the present invention, the step of controlling and adjusting the opening of the oil return control valve 22 according to the outdoor ambient temperature and the first exhaust parameter of the compressor 1 in the initial startup stage specifically includes:

[0071] When the current work phase is the initial start-up phase;

[0072] If it is determined that the outdoor ambient temperature is less than or equal to the set ambient temperature, or the exhaust temperature is less than or equal to the set exhaust temperature, the oil return control valve 22 is controlled to remain in a closed state;

[0073] Alternatively, if it is determined that the outdoor ambient temperature is greater than the set ambient temperature and the exhaust temperature is greater than the set exhaust temperature, the oil return control valve 22 is controlled to perform intermittent on-off control.

[0074] Further, the steps of controlling the oil return control valve 22 to perform intermittent on / off control specifically include:

[0075] The oil return control valve 22 is controlled to be first opened continuously for a first set time and then closed continuously for a second set time. The above operation is then cyclically performed on the oil return control valve 22 until the current working stage enters the normal operation stage.

[0076] The first set time length is shorter than the second set time length.

[0077] It should be noted that the purpose of the intermittent switch control of the oil return control valve 22 is as follows:

[0078] In the initial start-up stage, the oil return volume requirement of the compressor 1 is relatively low, and the amount of deposited oil at the bottom of the gas-liquid separator 2 is relatively small. If the oil return control valve 22 is not opened at this time, the oil return volume requirement of the compressor 1 cannot be met, and the deposited oil at the bottom of the gas-liquid separator 2 cannot be discharged, thereby affecting the normal operation of the system; however, if the oil return control valve 22 is opened at this time, although the oil return volume of the compressor 1 can be met, the liquid refrigerant at the bottom of the gas-liquid separator 2 will also enter the suction end of the compressor 1, thereby causing a liquid hammer fault. Therefore, considering the above factors, the method controls the intermittent switch of the oil return control valve 22 when the compressor 1 has an oil return demand, that is, first continuously opens for the first set time and then continuously closes for the second set time, and then cyclically performs the above operation. In this way, within the first set time of continuous opening, the deposited oil at the bottom of the gas-liquid separator 2 can be fully returned to the compressor 1, and within the second set time of continuous closing, the liquid refrigerant cannot flow to the suction end of the compressor 1 at this time, so the occurrence of liquid hammer fault can be avoided.

[0079] For example, Tao is the outdoor ambient temperature, which can be directly obtained through a temperature sensor. The set ambient temperature can be set to 20°C. Td is the exhaust temperature of compressor 1, which can be directly obtained through a temperature sensor. The set exhaust temperature can be set to 50°C.

[0080] In the initial startup stage: when Tao ≤ 20℃ or Td ≤ 50℃, the oil return solenoid valve is off (i.e. closed). When Tao>20℃ and Td>50℃, the oil return solenoid valve performs intermittent on-off control, i.e. the oil return control valve 22 is first opened for 10s and then closed for 20s until the system enters the normal operation stage.

[0081] In addition, if there are multiple oil return solenoid valve switches in parallel in the corresponding system, the multiple oil return solenoid valves will perform linkage and the same opening and closing control.

[0082] According to some embodiments of the present invention, when the current working stage is a normal operation stage, the step of controlling and adjusting the opening of the oil return control valve 22 according to the second exhaust parameter of the compressor 1 in the normal operation stage specifically includes:

[0083] When the current working stage is the normal operation stage, the liquid return control valve is controlled to remain in an open state;

[0084] Whenever the oil return control valve 22 is opened continuously for the third set time period, the air conditioner is controlled to enter the refrigerant return liquid judgment mode and continue for the fourth set time period, and after the fourth set time period, the oil return control valve 22 is controlled to reset to the open state, and then this step is executed in a loop.

[0085] In the refrigerant liquid return judgment mode, the opening of the oil return control valve 22 is adjusted according to the exhaust gas superheat of the compressor 1.

[0086] Furthermore, in the refrigerant liquid return judgment mode, the step of adjusting the opening of the oil return control valve 22 according to the exhaust gas superheat of the compressor 1 specifically includes:

[0087] According to the exhaust gas superheat of the compressor 1 being less than or equal to the first exhaust gas superheat, the oil return control valve 22 is controlled to be continuously closed for a fourth set time period, and after the fourth set time period ends, the oil return control valve 22 is controlled to continue to remain in an open state.

[0088] Furthermore, in the refrigerant liquid return judgment mode, the step of adjusting the opening of the oil return control valve 22 according to the exhaust gas superheat of the compressor 1 specifically includes:

[0089] Determine that the exhaust superheat of compressor 1 is greater than the second exhaust superheat, and the decrease rate of the exhaust superheat is greater than or equal to the set decrease rate, and the exhaust superheat decreases by the set decrease value within the fifth set time period, or determine that the exhaust superheat of compressor 1 is greater than the first exhaust superheat and less than or equal to the third exhaust superheat, then control the return oil control valve 22 to first be continuously opened for the first set time period and then continuously closed for the second set time period, and then cyclically perform the above operations on the return oil control valve 22 until the fourth set time period ends.

[0090] The first exhaust superheat is smaller than the second exhaust superheat, and the second exhaust superheat is smaller than the third exhaust superheat.

[0091] For example, Pd-t is the saturation temperature corresponding to the compressor exhaust pressure, which can be obtained by the pressure sensor to obtain the exhaust pressure Pd and convert it into the corresponding saturation temperature Pd-t. TdSH is the exhaust superheat of compressor 1, which is the difference between the exhaust temperature Td of compressor 1 and the exhaust saturation temperature Pd-t.

[0092] The first exhaust superheat can be set to 9°C, the second exhaust superheat can be set to 10°C, and the first exhaust superheat can be set to 12°C. In addition, the set drop speed can be set to 1°C / 8s, the third set time and the fifth set time can both be set to 1min, the set drop value can be set to 5°C, and the fourth set time can be set to 5min.

[0093] In the normal operation stage: the oil return control valve 22 performs ON control (ie, opens), and performs intermittent switch control or closing control when entering the following situations.

[0094] (1) When TdSH ≤ 12°C, or when TdSH is greater than 10°C, the TdSH decrease rate is ≥ 1°C / 8s and it decreases by 5°C within 1 minute, the oil return control valve 22 performs intermittent switching control, that is, the oil return control valve 22 is first opened for 10 seconds, then closed for 20 seconds, and then exits after 5 minutes.

[0095] (2) When TdSH ≤ 9°C, the oil return control valve 22 performs OFF control (ie, closes).

[0096] The above (1) and (2) are both executed for 5 minutes and then exit, after which the return oil control valve 22 continues to execute ON control and re-judges the above entry conditions after 1 minute.

[0097] The oil return control device of the air conditioner provided by the present invention is described below. The oil return control device of the air conditioner described below and the oil return control method of the air conditioner described above can be referred to each other.

[0098] like Figure 2 As shown, according to the oil return control device of the air conditioner in the second embodiment of the present invention, the bottom of the gas-liquid separator 2 in the air conditioner outdoor unit is provided with an oil return pipe 21 connected to the return air port of the compressor 1, and the oil return pipe 21 is provided with an oil return control valve 22. The oil return control device includes:

[0099] The acquisition module 110 is used to acquire the current working stage of the air conditioner and the exhaust parameters of the compressor 1;

[0100] The control module 120 is used to control and adjust the opening of the oil return control valve 22 according to the current working stage and exhaust parameters.

[0101] like Figure 3 As shown, the air conditioner according to the third embodiment of the present invention comprises an indoor heat exchanger 5, an outdoor heat exchanger 6, a four-way valve 4, an electronic expansion valve 7, an oil separator 3, a compressor 1 and a gas-liquid separator 2 connected by a refrigerant pipeline. Among them, an oil return pipe 21 connected to the return air port of the compressor 1 is provided at the bottom of the gas-liquid separator 2, and an oil return control valve 22 is provided on the oil return pipe 21;

[0102] An air conditioner memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the program, the oil return control method for the air conditioner as described in the first aspect of the present invention is implemented.

[0103] like Figure 3 As shown, according to some embodiments of the present invention, at least two oil return control valves 22 are provided on the oil return pipe 21, and all oil return control valves 22 are connected in parallel. In this way, the oil return flow rate of the oil return pipe 21 can be increased to meet the oil return volume demand of the compressor 1.

[0104] The air conditioner and its oil return control device according to the embodiment of the present invention can ensure that during the operation of the system, liquid refrigerant does not enter the return oil pipe 21 at the bottom of the gas separator to cause liquid hammer problem in the compressor 1, thereby ensuring the reliability of the system operation and reducing damage to the compressor 1.

[0105] Figure 4 An example of a physical structure diagram of an electronic device is shown in FIG. Figure 4 As shown, the electronic device may include: a processor 810, a communication interface 820, a memory 830 and a communication bus 840, wherein the processor 810, the communication interface 820 and the memory 830 communicate with each other through the communication bus 840. The processor 810 may call the logic instructions in the memory 830 to execute the oil return control method of the air conditioner, the method comprising: obtaining the current working stage of the air conditioner and the exhaust parameters of the compressor 1; and controlling and adjusting the opening of the oil return control valve 22 according to the current working stage and the exhaust parameters.

[0106] In addition, the logic instructions in the above-mentioned memory 830 can be implemented in the form of a software functional unit and can be stored in a computer-readable storage medium when it is sold or used as an independent product. Based on such an understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art or the part of the technical solution, can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the methods of each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk and other media that can store program codes.

[0107] On the other hand, the present invention also provides a computer program product, which includes a computer program. The computer program can be stored on a non-transitory computer-readable storage medium. When the computer program is executed by a processor, the computer can execute the oil return control method of the air conditioner provided by the above methods, and the method includes: obtaining the current working stage of the air conditioner and the exhaust parameters of the compressor 1; controlling and adjusting the opening of the return oil control valve 22 according to the current working stage and the exhaust parameters.

[0108] On the other hand, the present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon. When the computer program is executed by a processor, it is implemented to execute the oil return control method of the air conditioner provided by the above-mentioned methods. The method includes: obtaining the current working stage of the air conditioner and the exhaust parameters of the compressor 1; controlling and adjusting the opening of the return oil control valve 22 according to the current working stage and the exhaust parameters.

[0109] The device embodiments described above are merely illustrative, wherein the units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, i.e., they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the scheme of this embodiment. Those of ordinary skill in the art may understand and implement it without creative effort.

[0110] Through the description of the above implementation methods, those skilled in the art can clearly understand that each implementation method can be implemented by means of software plus a necessary general hardware platform, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solution is essentially or the part that contributes to the prior art can be embodied in the form of a software product, and the computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, a disk, an optical disk, etc., including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods of each embodiment or some parts of the embodiment.

[0111] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An oil return control method for an air conditioner, characterized in that: An oil return pipe connected to the return air port of the compressor is provided at the bottom of the gas-liquid separator in the outdoor unit of the air conditioner, and an oil return control valve is provided on the oil return pipe; the method comprises: Obtaining the current working stage of the air conditioner and exhaust parameters of the compressor; The opening of the oil return control valve is controlled and adjusted according to the current working stage and the exhaust parameter.

2. The oil return control method of the air conditioner according to claim 1, characterized in that: The current working stage includes the initial startup stage and the normal operation stage; Then the step of controlling and adjusting the opening of the oil return control valve according to the current working stage and the exhaust parameter specifically includes: In the case where the current working stage is a preliminary startup stage, obtaining the outdoor ambient temperature, and controlling and adjusting the opening of the oil return control valve according to the outdoor ambient temperature and the first exhaust parameter of the compressor in the preliminary startup stage; In a case where the current working stage is a normal operation stage, the opening of the oil return control valve is controlled and adjusted according to the second exhaust parameter of the compressor in the normal operation stage.

3. The oil return control method of the air conditioner according to claim 2, characterized in that: The first exhaust parameter includes the exhaust temperature of the compressor, and the second exhaust parameter includes the exhaust superheat of the compressor.

4. The oil return control method of the air conditioner according to claim 3, characterized in that: The step of controlling and adjusting the opening of the oil return control valve according to the outdoor ambient temperature and the first exhaust parameter of the compressor in the initial startup stage specifically includes: Where the current working phase is the initial start-up phase; Determining that the outdoor ambient temperature is less than or equal to the set ambient temperature, or the exhaust temperature is less than or equal to the set exhaust temperature, then controlling the oil return control valve to remain in a closed state; Alternatively, if it is determined that the outdoor ambient temperature is greater than the set ambient temperature and the exhaust temperature is greater than the set exhaust temperature, the oil return control valve is controlled to perform intermittent on-off control.

5. The oil return control method of the air conditioner according to claim 4, characterized in that: The step of controlling the oil return control valve to perform intermittent on-off control specifically includes: Controlling the oil return control valve to first be continuously opened for a first set time and then continuously closed for a second set time, and then cyclically performing the above operation on the oil return control valve until the current working stage enters the normal operation stage; The first set duration is shorter than the second set duration.

6. The oil return control method of the air conditioner according to claim 3, characterized in that: When the current working stage is a normal operation stage, the step of controlling and adjusting the opening of the oil return control valve according to the second exhaust parameter of the compressor in the normal operation stage specifically includes: When the current working stage is a normal operation stage, controlling the liquid return control valve to remain in an open state; Whenever the oil return control valve is opened for a third set time, the air conditioner is controlled to enter a refrigerant return liquid determination mode and continue for a fourth set time, and after the fourth set time, the oil return control valve is controlled to be reset to an open state, and this step is then executed repeatedly; Wherein, in the refrigerant liquid return judgment mode, the opening of the oil return control valve is adjusted according to the exhaust gas superheat of the compressor.

7. The oil return control method of the air conditioner according to claim 6, characterized in that: The step of adjusting the opening of the oil return control valve according to the exhaust gas superheat of the compressor in the refrigerant liquid return judgment mode specifically includes: According to the exhaust gas superheat of the compressor being less than or equal to the first exhaust gas superheat, the oil return control valve is controlled to be continuously closed for the fourth set time period, and after the fourth set time period ends, the oil return control valve is controlled to continue to remain in an open state.

8. The oil return control method of the air conditioner according to claim 7, characterized in that: The step of adjusting the opening of the oil return control valve according to the exhaust gas superheat of the compressor in the refrigerant liquid return judgment mode specifically includes: Determining that the exhaust superheat of the compressor is greater than the second exhaust superheat, and the decreasing speed of the exhaust superheat is greater than or equal to the set decreasing speed, and the exhaust superheat decreases by the set decreasing value within the fifth set time, or determining that the exhaust superheat of the compressor is greater than the first exhaust superheat and less than or equal to the third exhaust superheat, then controlling the oil return control valve to first be continuously opened for the first set time and then continuously closed for the second set time, and then cyclically performing the above operation on the oil return control valve until the fourth set time ends; The first exhaust superheat is smaller than the second exhaust superheat, and the second exhaust superheat is smaller than the third exhaust superheat.

9. An oil return control device for an air conditioner, characterized in that: An oil return pipe connected to the return air port of the compressor is provided at the bottom of the gas-liquid separator in the outdoor unit of the air conditioner, and an oil return control valve is provided on the oil return pipe; the device comprises: An acquisition module, used to acquire the current working stage of the air conditioner and the exhaust parameters of the compressor; The control module is used to control and adjust the opening of the oil return control valve according to the current working stage and the exhaust parameter.

10. An air conditioner, characterized in that: include: An indoor heat exchanger, an outdoor heat exchanger, a four-way valve, an electronic expansion valve, a compressor and a gas-liquid separator connected by a refrigerant pipeline, wherein an oil return pipe connected to the air return port of the compressor is provided at the bottom of the gas-liquid separator, and an oil return control valve is provided on the oil return pipe; A memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the oil return control method for the air conditioner as claimed in any one of claims 1 to 8 when executing the program.

11. The air conditioner according to claim 10, characterized in that: At least two oil return control valves are arranged on the oil return pipe, and all the oil return control valves are connected in parallel.

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