Air conditioner and control method thereof

Abstract

The invention discloses an air conditioner and a control method thereof. The air conditioner comprises a refrigerant circulation loop, a throttling device, a separator, an oil return control device and a controller. Wherein the controller is configured to judge whether the separator outputs lubricating oil or not through the oil return control device after the compressor is started to run for a first preset time, and control the oil return control device according to a judgment result, so that the lubricating oil output by the separator returns to the compressor through the oil return control device, or the compressor is started to run for a second preset time. The refrigerant is prevented from returning to the compressor through the oil return control device, so that the situation that the separated lubricating oil enters a throttling device to make the air conditioner unable to operate or reduce the capacity is avoided, meanwhile, compressor damage caused by lack of lubricating oil can be avoided, and on the other hand, excessive lubricating oil can be prevented from entering an evaporator to affect heat exchange of the evaporator.

Description

Technical Field

[0001] The present invention relates to the technical field of air conditioners, and in particular to an air conditioner and a control method thereof. Background Art

[0002] In the prior art, if the refrigeration device of the air conditioner adopts a natural refrigerant such as R290 refrigerant, due to its excellent solubility with the compressor lubricating oil, the refrigerant is likely to bring the lubricating oil out of the compressor and into the condenser during operation; since the charge amount of R290 refrigerant is small, if the amount of oil brought out is too much, it is easy to cause the concentration of the lubricating oil in the R290 refrigerant to be too high, and it will precipitate in the liquid refrigerant at the outlet of the condenser and enter the throttling device, causing the throttling device to be semi-blocked, resulting in a sharp drop in the refrigerant flow of the refrigeration device, thereby causing a decrease in the refrigeration capacity, and even excessive exhaust temperature, making the machine unable to operate. Summary of the invention

[0003] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the purpose of the present invention is to provide an air conditioner and a control method thereof.

[0004] An air conditioner proposed by the present invention comprises: a refrigerant circulation circuit, wherein the refrigerant performs a refrigeration cycle in a circuit composed of a compressor, a condenser, a throttling device, and an evaporator, wherein one of the condenser and the evaporator is an outdoor heat exchanger and the other is an indoor heat exchanger; the throttling device is arranged between the condenser and the evaporator, and is used to increase the flow resistance of the refrigerant passing through the throttling device when the opening degree of the throttling device is reduced, and to reduce the flow resistance of the refrigerant passing through the throttling device when the opening degree of the throttling device is increased; a separator, wherein the separator is arranged between the condenser and the throttling device, and the separator comprises an inlet, an outlet, and an oil outlet; wherein the inlet is connected to the outlet of the condenser, the outlet is connected to the throttling device, and the oil outlet is connected to the oil return control device, and the separator is used to separate the lubricating oil and the refrigerant in the high-temperature and high-pressure refrigerant liquid discharged from the condenser, and the lubricating oil is discharged through the throttling device. The oil outlet is output to the inlet of the oil return control device, and the refrigerant is output to the throttling device through the outlet; the oil return control device, the oil return control device is arranged between the separator and the suction port of the compressor, the oil return control device is used to return the lubricating oil to the compressor through the outlet of the oil return control device when the separator outputs the lubricating oil; and when the separator does not output the lubricating oil, prevent the refrigerant from returning to the compressor through the outlet of the oil return control device; the controller is configured to: after the compressor starts running for a first preset time, determine whether the separator outputs the lubricating oil through the oil return control device, and control the oil return control device according to the determination result, so that the lubricating oil output by the separator returns to the compressor through the oil return control device, or prevent the refrigerant from returning to the compressor through the oil return control device.

[0005] In addition, the air conditioner according to the embodiment of the present invention may also have the following additional technical features:

[0006] Furthermore, the oil return control device includes: a first liquid channel and a second liquid channel connected in parallel, the inlets of the first liquid channel and the second liquid channel are respectively connected to the oil outlet of the separator, and the outlets of the first liquid channel and the second liquid channel are respectively connected to the suction port of the compressor; the controller is configured to: determine whether the separator outputs the lubricating oil by obtaining the temperature of the liquid flowing through the first liquid channel.

[0007] Furthermore, the oil return control device includes: a first pressure reducing device arranged on the first liquid channel, the first pressure reducing device being used to throttle and reduce the pressure of the refrigerant or the lubricating oil flowing through the first pressure reducing device; a first temperature sensor, the first temperature sensor being arranged at the inlet of the first pressure reducing device, being used to detect a first temperature of the refrigerant or the lubricating oil flowing into the inlet of the first pressure reducing device; and a second temperature sensor, the second temperature sensor being arranged at the outlet of the first pressure reducing device, being used to detect a second temperature of the refrigerant or the lubricating oil flowing out of the outlet of the first pressure reducing device.

[0008] Furthermore, the oil return control device comprises: a second pressure reducing device arranged on the second liquid channel, the second pressure reducing device is used to throttle and reduce the pressure of the lubricating oil flowing through the second pressure reducing device; an electromagnetic two-way valve arranged on the second liquid channel, the electromagnetic two-way valve is connected in series with the second pressure reducing device. Furthermore,

[0009] Further, when judging whether the separator outputs the lubricating oil through the oil return control device, the controller is specifically configured to: obtain the first temperature and the second temperature; calculate the difference between the first temperature and the second temperature; when the difference is not greater than the preset temperature and the duration reaches the second preset time, judge that the separator outputs the lubricating oil; when the difference is greater than the preset temperature and the duration reaches the third preset time, judge that the separator does not output the lubricating oil.

[0010] Furthermore, when the oil return control device is controlled according to the judgment result, the controller is specifically configured as follows: when it is judged that the separator outputs the lubricating oil, the electromagnetic two-way valve is controlled to be opened so that the lubricating oil output by the separator returns to the compressor through the oil return control device; when it is judged that the separator does not output the lubricating oil, the electromagnetic two-way valve is controlled to be closed to prevent the refrigerant from returning to the compressor through the oil return control device.

[0011] Furthermore, the first pressure reducing device, the second pressure reducing device and the throttling device are all one of a capillary tube, a throttling valve or an electronic expansion valve.

[0012] Further, under the same pressure difference conditions, when the first pressure reducing device, the second pressure reducing device and the throttling device are all in the open state, the flow rate of the first pressure reducing device is smaller than the flow rate of the second pressure reducing device, and the flow rate of the second pressure reducing device is smaller than the flow rate of the throttling device.

[0013] Furthermore, the inlet and the outlet of the separator are located at the top of the separator, and the oil outlet is located at the bottom of the separator.

[0014] According to the air conditioner of the embodiment of the present invention, when the compressor starts to run for the first preset time, the oil return control device is used to determine whether the separator outputs lubricating oil, and the oil return control device is controlled according to the determination result, so that the lubricating oil output by the separator returns to the compressor through the oil return control device, or the refrigerant is prevented from returning to the compressor through the oil return control device, so as to prevent the precipitated lubricating oil from entering the throttling device so that the air conditioner cannot operate or its capacity is reduced, and at the same time, it can also prevent the compressor from being damaged due to lack of lubricating oil, and on the other hand, it can also prevent too much lubricating oil from entering the evaporator and affecting the heat exchange of the evaporator.

[0015] In response to the above-mentioned problems, the present invention further proposes a control method for an air conditioner, which is used for an air conditioner as described in any of the above-mentioned embodiments, and the method comprises the following steps: after the compressor starts running for a first preset time, judging whether the separator outputs lubricating oil through an oil return control device; controlling the oil return control device according to the judgment result so that the lubricating oil output by the separator returns to the compressor through the oil return control device, or preventing the refrigerant from returning to the compressor through the oil return control device.

[0016] According to the control method of the air conditioner of the embodiment of the present invention, when the compressor starts to run for a first preset time, the oil return control device is used to determine whether the separator outputs lubricating oil, and the oil return control device is controlled according to the determination result, so that the lubricating oil output by the separator returns to the compressor through the oil return control device, or the refrigerant is prevented from returning to the compressor through the oil return control device, so as to prevent the precipitated lubricating oil from entering the throttling device so that the air conditioner cannot operate or its capacity is reduced, and at the same time, it can also prevent the compressor from being damaged due to lack of lubricating oil, and on the other hand, it can also prevent too much lubricating oil from entering the evaporator and affecting the heat exchange of the evaporator.

[0017] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The above and additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0019] Figure 1 is a structural schematic diagram of an air conditioner according to an embodiment of the present invention;

[0020] Figure 2 is a schematic diagram of the structure of a controller according to an embodiment of the present invention;

[0021] Figure 3 is a structural schematic diagram of an air conditioner according to another embodiment of the present invention;

[0022] Figure 4 is a structural schematic diagram of an air conditioner according to yet another embodiment of the present invention;

[0023] Figure 5 is a schematic structural diagram of an oil return control device according to an embodiment of the present invention;

[0024] Figure 6 is a schematic structural diagram of a separator according to an embodiment of the present invention;

[0025] Figure 7 is a flow chart of a method for controlling an air conditioner according to an embodiment of the present invention;

[0026] Figure 8 is a schematic diagram of a flow chart of determining whether a separator outputs lubricating oil through an oil return control device according to an embodiment of the present invention;

[0027] Fig. 9 It is a flow chart of controlling the oil return control device by judging whether the separator outputs lubricating oil according to an embodiment of the present invention.

[0028] Reference numerals:

[0029] Indoor unit-1; outdoor unit-2; control device-200; air conditioner-10; refrigerant circulation circuit-11; throttling device-12; separator-13; oil return control device-14; compressor-110; compressor exhaust port-1101; compressor suction port-1102; condenser-111; condenser outlet-1111; evaporator-112; separator inlet-130; separator outlet-131; separator oil outlet-132; first liquid channel-140; second liquid channel-141; first pressure reducing device-142; first temperature sensor-143; second temperature sensor-144; second pressure reducing device-145; electromagnetic two-way valve-146; controller-71. DETAILED DESCRIPTION

[0030] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only 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.

[0031] In the description of the present invention, it should be understood that the terms "center", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0032] The terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "plurality" means two or more.

[0033] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0034] The present application embodiment provides an air conditioner 10, referring to Figure 1 and Figure 2 The air conditioner 10 includes a refrigeration system for exchanging heat with indoor air to meet cooling or heating needs.

[0035] The refrigeration system includes a compressor, a condenser, a throttling device, and an evaporator, and the air conditioner 10 in the present application performs a refrigeration cycle of the air conditioner 10 by using the compressor, the condenser, the throttling device, and the evaporator. The refrigeration cycle includes a series of processes involving compression, condensation, expansion, and evaporation, and supplies refrigerant to the conditioned and heat-exchanged air.

[0036] The compressor compresses the refrigerant gas at high temperature and high pressure and discharges the compressed refrigerant gas. The discharged refrigerant gas flows into the condenser. The condenser condenses the compressed refrigerant into liquid phase, and the heat is released to the surrounding environment through the condensation process.

[0037] The throttling device expands the high-temperature and high-pressure liquid refrigerant condensed in the condenser into a low-pressure liquid refrigerant. The evaporator evaporates the refrigerant expanded in the throttling device and returns the refrigerant gas in a low-temperature and low-pressure state to the compressor.

[0038] The evaporator can achieve a refrigeration effect by utilizing the latent heat of evaporation of the refrigerant to exchange heat with the material to be cooled. In the entire cycle, the air conditioner 10 can adjust the temperature of the indoor space.

[0039] The outdoor unit 2 of the air conditioner 10 refers to a part of a refrigeration cycle including a compressor and an outdoor heat exchanger, the indoor unit 1 of the air conditioner 10 includes an indoor heat exchanger, and a throttling device may be provided in the indoor unit 1 or the outdoor unit 2 .

[0040] The indoor heat exchanger and the outdoor heat exchanger function as a condenser or an evaporator. When the indoor heat exchanger functions as a condenser, the air conditioner 10 functions as a heater in a heating mode, and when the indoor heat exchanger functions as an evaporator, the air conditioner 10 functions as a cooler in a cooling mode.

[0041] The air conditioner 10 in the present application includes an indoor unit 1 and an outdoor unit 2, and the indoor unit 1 and the outdoor unit 2 can be configured as an integrated unit or a split unit. The indoor unit 1 can be configured as a wall-mounted unit, a ceiling unit, a duct unit, etc., and the indoor unit 1 is installed on the top of the indoor room.

[0042] Reference Figure 1 Taking an indoor wall mounted unit as an example, the indoor wall mounted unit is usually installed at a location such as an indoor wall. For another example, an indoor cabinet unit (not shown in the figure) is also a form of the indoor unit 1 .

[0043] Taking a split unit as an example, the air conditioner 10 includes an indoor unit 1 and an outdoor unit 2, wherein the outdoor unit 2 is usually arranged outdoors for heat exchange in the indoor environment.

[0044] In addition, as shown in the figure, the air conditioner 10 is provided with a controller 71 to control the operation of various components in the air conditioner 10, so that the various components of the air conditioner 10 are operated to realize various predetermined functions of the air conditioner 10. Among them, the air conditioner 10 is also provided with a control device 200. Exemplarily, the control device 200 is specifically configured as a remote controller, which has the function of communicating with the controller 71 using infrared or other communication methods, for example. The remote controller is used for the user to perform various controls on the air conditioner 10 and realize the interaction between the user and the air conditioner 10.

[0045] The indoor unit 1 of the air conditioner 10 in the embodiment of the present application is arranged at the top or upper part of the room. Generally speaking, the installation height of the indoor unit 1 is higher than the user activity area. The indoor unit 1 includes a return air inlet and an air outlet connected to the room. The indoor air passes through the return air inlet of the indoor unit 1 and flows back to the room through the air outlet.

[0046] The refrigerant circulation loop in the present application allows the refrigerant to circulate in a loop consisting of a compressor, a condenser, a throttling device, and an evaporator. One of the condenser and the evaporator is an outdoor heat exchanger, and the other is an indoor heat exchanger. The indoor heat exchanger is used to exchange heat with the air in the indoor unit 1, and the outdoor unit 2 heat exchanger is used to exchange heat with the air in the outdoor unit 2, thereby achieving the cooling or heating requirements of the air conditioner 10.

[0047] The indoor unit 1 also includes an indoor fan, which is arranged near the return air port or the air outlet of the indoor heat exchanger and is used to deliver the heat-exchanged air to the room. The indoor fan includes multiple gears for changing the outlet air flow speed of the outlet.

[0048] An air guide plate is provided at the position of the air outlet. The air guide plate adjusts the outflow direction of the air flowing through the air outlet by changing the relative rotation angle between the air guide plate and the air outlet, thereby affecting the indoor air temperature stratification.

[0049] In the embodiment shown in the present application, the air conditioner 10 further includes a controller 71, which refers to a device that can generate an operation control signal according to the instruction operation code and the timing signal to instruct the air conditioner 10 to execute the control instruction. For example, in response to a power-on or power-off instruction received from a user, the controller 71 can execute an operation related to the object selected by the power-on or power-off instruction.

[0050] The present application also provides a hardware structure diagram of a controller 71, such as Figure 2 As shown, the controller 71 includes a processor 83, and optionally, further includes a memory 82 and a communication interface 84 connected to the processor 83. The processor 83, the memory 82 and the communication interface 84 are connected via a bus 81.

[0051] The processor 83 may be a central processing unit 83 (CPU), a general processor 83, a network processor 83 (NP), a digital signal processor 83 (DSP), a microprocessor 83, a microcontroller 718, a programmable logic device (PLD), or any combination thereof. The processor 83 may also be any other device having a processing function, such as a circuit, a device, or a software module. The processor 83 may also include multiple CPUs, and the processor 83 may be a single-CPU processor 83 or a multi-CPU processor 83. The processor 83 here may refer to one or more devices, circuits, or processing cores for processing data (such as computer program instructions).

[0052] The memory 82 may be a read-only memory 82 (ROM) or other types of static storage devices that can store static information and instructions, a random access memory 82 (RAM) or other types of dynamic storage devices that can store information and instructions, or an electrically erasable programmable read-only memory 82 (EEPROM), a compact disc read-only memory (CD-ROM) or other optical disc storage, optical disc storage (including compressed optical disc, laser disc, optical disc, digital versatile disc, Blu-ray disc, etc.), a magnetic disk storage medium or other magnetic storage device, or any other medium that can be used to carry or store the desired program code in the form of an instruction or data structure and can be accessed by a computer, and the embodiment of the present application does not impose any restrictions on this. The memory 82 may exist independently or be integrated with the processor 83. Among them, the memory 82 may contain a computer program code. The processor 83 is used to execute the computer program code stored in the memory 82, thereby realizing the air conditioner provided in the embodiment of the present application.

[0053] The communication interface 84 can be used to communicate with other devices or communication networks (such as Ethernet, radio access network (RAN), wireless local area networks (WLAN), etc. The communication interface 84 can be a module, a circuit, a transceiver or any device that can achieve communication.

[0054] The bus 81 may be a peripheral component interconnect (PCI) bus 81 or an extended industry standard architecture (EISA) bus 81, etc. The bus 81 may be divided into an address bus 81, a data bus 81, a control bus 81, etc.

[0055] Reference below Figure 3-Figure 9 The air conditioner 10 and the control method thereof according to the embodiment of the present invention are described.

[0056] Figure 3 is a schematic structural diagram of an air conditioner 10 according to an embodiment of the present invention, Figure 4 FIG. 1 is a schematic diagram of the structure of an air conditioner 10 according to another embodiment of the present invention. Figure 3 and Figure 4As shown, an air conditioner 10 includes: a refrigerant circulation circuit 11, a throttling device 12, a separator 13 and an oil return control device 14. The refrigerant circulation circuit 11 allows the refrigerant to perform a refrigeration cycle in a circuit composed of a compressor 110, a condenser 111, a throttling device 12 and an evaporator 112. One of the condenser 111 and the evaporator 112 is an outdoor heat exchanger, and the other is an indoor heat exchanger. The throttling device 12 is arranged between the condenser 111 and the evaporator 112. The throttling device 12 is used to increase the flow resistance of the refrigerant passing through the throttling device 12 when its opening is reduced, and to increase the flow resistance of the refrigerant passing through the throttling device 12 when its opening is increased. The flow resistance of the refrigerant in the device 12 is reduced; the separator 13 is arranged between the condenser 111 and the throttling device 12, and the separator 13 includes an inlet 130 of the separator, an outlet 131 of the separator and an oil outlet 132 of the separator; wherein the inlet 130 of the separator is connected to the condenser outlet 1111, the outlet 131 of the separator is connected to the throttling device 12, and the oil outlet 132 of the separator is connected to the oil return control device 14, and the separator 13 is used to return the high-temperature and high-pressure refrigerant discharged from the condenser 111 to the oil return control device 14. The lubricating oil and refrigerant in the liquid are separated, and the lubricating oil is output to the inlet of the oil return control device 14 through the oil outlet 132 of the separator, and the refrigerant is output to the throttling device 12 through the separator outlet 131; the oil return control device 14 is arranged between the separator 13 and the air intake of the compressor 110, and the oil return control device 14 is used to return the lubricating oil to the compressor 110 through the outlet of the oil return control device 14 when the separator 13 outputs the lubricating oil; and when the separator 13 does not output the lubricating oil, prevent the refrigerant from returning to the compressor 110 through the outlet of the oil return control device 14; the controller 71 is configured to: after the compressor 110 starts to run for a first preset time, determine whether the separator 13 outputs the lubricating oil through the oil return control device 14, and control the oil return control device 14 according to the determination result, so that the lubricating oil output by the separator 13 returns to the compressor 110 through the oil return control device 14, or prevent the refrigerant from returning to the compressor 110 through the oil return control device 14. Specifically, the throttling device 12 is one of a capillary tube, a throttling valve or an electronic expansion valve.

[0057] Specifically, taking the cooling mode as an example, when the compressor 110 starts running for the first preset time, for example, ten minutes, it is considered that the air conditioner 10 has entered the stable operation stage. In the cooling mode, the high-temperature and high-pressure refrigerant gas discharged by the compressor 110 enters the condenser 111 through the exhaust port 1101 of the compressor and is cooled into a high-temperature and high-pressure refrigerant supercooled liquid, and then the high-temperature and high-pressure refrigerant supercooled liquid enters the separator 13. When the compressor 110 spits out too much lubricating oil, the lubricating oil dissolved in the high-temperature and high-pressure refrigerant supercooled liquid in the separator 13 will precipitate. Since the liquid density of the refrigerant is lower than the density of the lubricating oil, the precipitated lubricating oil is at the bottom of the separator 13, and the lubricating oil is separated by the separator 13. The oil return control device 14 is used to determine whether the separator 13 outputs lubricating oil. The oil return control device 14 is controlled according to the determination result. For example, when the determination result is that the separator 13 outputs lubricating oil, the lubricating oil output by the separator 13 is returned to the compressor 110 through the oil return control device 14. Or, when the determination result is that the separator 13 does not output lubricating oil, the refrigerant is prevented from returning to the compressor 110 through the oil return control device 14. This prevents the precipitated lubricating oil from entering the throttling device 12, which makes the air conditioner unable to operate or reduces its capacity. At the same time, it can also prevent the compressor 110 from being damaged due to lack of lubricating oil. On the other hand, it can also prevent too much lubricating oil from entering the evaporator and affecting the heat exchange of the evaporator.

[0058] In one embodiment of the present invention, the oil return control device 14 includes: a first liquid channel 140 and a second liquid channel 141 connected in parallel, the inlets of the first liquid channel 140 and the second liquid channel 141 are respectively connected to the oil outlet 132 of the separator, and the outlets of the first liquid channel 140 and the second liquid channel 141 are respectively connected to the suction port 1102 of the compressor; the controller 71 is configured to: determine whether the separator 13 outputs lubricating oil by obtaining the temperature of the liquid flowing through the first liquid channel 140.

[0059] Specifically, if Figure 4 As shown, the first liquid channel 140 and the second liquid channel 141 are connected in parallel, the inlets of the first liquid channel 140 and the second liquid channel 141 are respectively connected to the oil outlet 132 of the separator, and the outlets of the first liquid channel 140 and the second liquid channel 141 are respectively connected to the air intake port 1102 of the compressor. Since the temperature of the refrigerant or lubricating oil output by the separator 13 will be different when passing through the first liquid channel 140, the embodiment of the present invention determines whether the separator 13 outputs lubricating oil by obtaining the temperature of the liquid flowing through the first liquid channel 140, so that when the separator 13 outputs lubricating oil, the lubricating oil is returned to the compressor 110 through the second liquid channel 141, or when the judgment result is that the separator 13 does not output lubricating oil, the refrigerant is prevented from returning to the compressor 110 through the second liquid channel 141.

[0060] In one embodiment of the present invention, the oil return control device 14 includes: a first pressure reducing device 142 disposed on the first liquid channel 140, the first pressure reducing device 142 is used to throttle and reduce the pressure of the refrigerant or lubricating oil flowing through the first pressure reducing device 142; a first temperature sensor 143, the first temperature sensor 143 is disposed at the inlet of the first pressure reducing device 142, and is used to detect the first temperature of the refrigerant or lubricating oil flowing into the inlet of the first pressure reducing device 142; a second temperature sensor 144, the second temperature sensor 144 is disposed at the outlet of the first pressure reducing device 142, and is used to detect the second temperature of the refrigerant or lubricating oil flowing out of the outlet of the first pressure reducing device 142. Specifically, the first pressure reducing device 142 is one of a capillary tube, a throttle valve, or an electronic expansion valve.

[0061] Specifically, if Figure 5 As shown, the first pressure reducing device 142 is arranged on the first liquid channel 140, and when the separator 13 outputs the refrigerant or lubricating oil, the first pressure reducing device 142 throttles and reduces the pressure on the refrigerant or lubricating oil. Since the refrigerant will produce a pressure drop effect when passing through the first pressure reducing device 142, and its temperature will decrease, while the viscosity of the lubricating oil is very large, and when passing through the first pressure reducing device 142, no pressure drop effect will be produced, and its temperature will not change. Therefore, according to the difference in temperature of the refrigerant or lubricating oil after throttling and reducing the pressure, it is judged whether the separator 13 outputs the lubricating oil, that is, the temperature of the refrigerant or lubricating oil is detected by the first temperature sensor 143 arranged at the inlet of the first pressure reducing device 142 and the second temperature sensor 144 arranged at the outlet of the first pressure reducing device 142, and it is judged whether the separator 13 outputs the lubricating oil according to the temperature change.

[0062] In one embodiment of the present invention, the oil return control device 14 includes: a second pressure reducing device 145 disposed on the second liquid channel 141, the second pressure reducing device 145 is used to throttle and reduce the pressure of the lubricating oil flowing through the second pressure reducing device 145; and an electromagnetic two-way valve 146 disposed on the second liquid channel 141, the electromagnetic two-way valve 146 is connected in series with the second pressure reducing device 145. Specifically, the second pressure reducing device 145 is one of a capillary tube, a throttle valve or an electronic expansion valve.

[0063] Specifically, if Figure 4As shown, a second pressure reducing device 145 is provided on the second liquid channel 141, and the second pressure reducing device 145 is used to throttle and reduce the pressure of the lubricating oil flowing through the second pressure reducing device 145; at the same time, an electromagnetic two-way valve 146 is provided on the second liquid channel 141, which is connected in series with the second pressure reducing device 145. It can be understood that when judging whether the separator 13 outputs lubricating oil according to the temperature of the liquid flowing through the first liquid channel 140, the electromagnetic two-way valve 146 is in a closed state, so that the lubricating oil or refrigerant output by the separator 13 only passes through the first liquid channel 140, so as to judge whether the separator 13 outputs lubricating oil according to the change of the liquid temperature of the first liquid channel 140, so as to avoid the refrigerant returning to the compressor 110 through the second liquid channel 141 when the separator 13 does not output lubricating oil.

[0064] In one embodiment of the present invention, when judging whether the separator 13 outputs lubricating oil through the oil return control device 14, the controller 71 is specifically configured to: obtain a first temperature and a second temperature; calculate the difference between the first temperature and the second temperature; when the difference is not greater than a preset temperature and the duration reaches a second preset time, judge that the separator 13 outputs lubricating oil; when the difference is greater than the preset temperature and the duration reaches a third preset time, judge that the separator 13 does not output lubricating oil.

[0065] Specifically, when judging whether the separator 13 outputs lubricating oil through the oil return control device 14, the first temperature of the liquid before passing through the first pressure reducing device 142 and the second temperature of the liquid after passing through the first pressure reducing device 142 are respectively obtained through the first temperature sensor 143 and the second temperature sensor 144, and the difference between the first temperature and the second temperature is calculated. When the difference is not greater than the preset temperature and the duration reaches the second preset time, it is considered that the temperature difference of the liquid is small after passing through the first pressure reducing device 142, and the main component in the first liquid channel 140 is lubricating oil, thereby judging that the separator 13 outputs lubricating oil; when the difference is greater than the preset temperature and the duration reaches the third preset time, it is considered that the temperature difference of the liquid is large after passing through the first pressure reducing device 142, and the main component in the first liquid channel 140 is refrigerant, thereby judging that the separator 13 does not output lubricating oil.

[0066] In a specific embodiment, the first temperature is, for example, T1, the second temperature is, for example, T2, and the difference is △T, then △T=T1-T2, the preset temperature is, for example, 2°C, when △T≤2°C, and the duration reaches the second preset time, for example, 2 minutes, it is judged that the separator 13 outputs lubricating oil; when △T>2°C, and the duration reaches the third preset time, for example, 1 minute, it is judged that the separator 13 does not output lubricating oil.

[0067] In one embodiment of the present invention, when the oil return control device 14 is controlled according to the judgment result, the controller 71 is specifically configured as follows: when it is judged that the separator 13 outputs lubricating oil, the electromagnetic two-way valve 146 is controlled to be opened so that the lubricating oil output by the separator 13 returns to the compressor 110 through the oil return control device 14; when it is judged that the separator 13 does not output lubricating oil, the electromagnetic two-way valve 146 is controlled to be closed to prevent the refrigerant from returning to the compressor 110 through the oil return control device 14.

[0068] Specifically, when it is determined that the separator 13 outputs lubricating oil, the electromagnetic two-way valve 146 is controlled to open so that the lubricating oil output by the separator 13 returns to the compressor 110 from the second liquid channel 141 of the oil return control device 14; when it is determined that the separator 13 does not output lubricating oil, the electromagnetic two-way valve 146 is controlled to close so that the resistance refrigerant returns to the compressor 110 through the second liquid channel 141. In this way, it can be prevented that the precipitated lubricating oil enters the throttling device 12 so that the air conditioner 10 cannot operate or the capacity is reduced, and at the same time, it can also prevent the compressor 110 from being damaged due to lack of lubricating oil, and on the other hand, it can also prevent excessive oil from entering the evaporator 112 to affect the heat exchange of the evaporator.

[0069] In one embodiment of the present invention, under the same pressure difference conditions, when the first pressure reducing device 142, the second pressure reducing device 145 and the throttling device 12 are all in the open state, the flow rate of the first pressure reducing device 142 is smaller than the flow rate of the second pressure reducing device 145, and the flow rate of the second pressure reducing device 145 is smaller than the flow rate of the throttling device 12.

[0070] Specifically, when the first pressure reducing device 142, the second pressure reducing device 145 and the throttling device 12 are all in the open state, the flow rate of the first pressure reducing device 142 is less than the flow rate of the second pressure reducing device 145. If the separator 13 outputs lubricating oil, the electromagnetic two-way valve 146 is controlled to open. Since the flow rate of the first pressure reducing device 142 is less than the flow rate of the second pressure reducing device 145, the lubricating oil mainly returns to the compressor 110 through the second pressure reducing device 145. In addition, the flow rate of the first pressure reducing device 142 is set to the minimum and the flow rate of the throttling device 12 is set to the maximum. When it is determined that the separator 13 does not output lubricating oil according to the first pressure reducing device 142, more refrigerant can be prevented from entering the compressor 110 through the first pressure reducing device 142, so that the refrigerant mainly enters the evaporator 112 through the throttling device 12, and the refrigeration capacity of the compressor 110 is ensured not to decrease. That is, in the embodiment of the present invention, under the condition of the same pressure difference and fully open, the flow rate of the first pressure reducing device 142 is set to be smaller to determine whether the separator 13 outputs the lubricating oil; the flow rate of the second pressure reducing device 145 is set to be larger, so that after determining that the separator 13 outputs the lubricating oil, the lubricating oil is output to the compressor 110 through the second pressure reducing device 145; the flow rate of the throttling device 12 is maximum to ensure that the cooling capacity of the compressor 110 does not decrease.

[0071] In a specific embodiment, under the condition of the same pressure difference and fully open, the flow rate of the first pressure reducing device 142 is, for example, m0, the flow rate of the second pressure reducing device 145 is, for example, 20×m0, and the flow rate of the throttling device 12 is 100×m0.

[0072] In one embodiment of the present invention, the separator inlet 130 and the separator outlet 131 are located at the top of the separator 13 , and the separator oil outlet 132 is located at the bottom of the separator 13 .

[0073] Specifically, since the density of lubricating oil is greater than that of refrigerant, e.g. Figure 6 As shown, the separator inlet 130 and the separator outlet 131 are located at the top of the separator 13, so that the refrigerant located at the upper part of the separator 13 is output to the throttling device 12 through the top of the separator 13, and the oil outlet is located at the bottom of the separator 13, so that the lubricating oil located at the lower part of the separator 13 is output to the oil return control device 14 through the bottom of the separator 13, and the refrigerant is transported to the throttling device 12. In this way, the precipitated lubricating oil can be prevented from entering the throttling device 12 to make the air conditioner 10 unable to operate or reduce its capacity. At the same time, it can also prevent the compressor 110 from being damaged due to lack of lubricating oil. On the other hand, it can also prevent too much lubricating oil from entering the evaporator 112 to affect the heat exchange of the evaporator.

[0074] According to the air conditioner 10 of the embodiment of the present invention, after the compressor 110 starts to run for the first preset time, the oil return control device 14 is used to determine whether the separator 13 outputs lubricating oil. The oil return control device 14 is controlled according to the determination result so that the lubricating oil output by the separator 13 returns to the compressor 110 through the oil return control device 14, or the refrigerant is prevented from returning to the compressor 110 through the oil return control device 14, so as to prevent the precipitated lubricating oil from entering the throttling device 12 so that the air conditioner 10 cannot operate or its capacity is reduced. At the same time, it can also prevent the compressor 110 from being damaged due to lack of lubricating oil. On the other hand, it can also prevent too much lubricating oil from entering the evaporator 112 and affecting the heat exchange of the evaporator.

[0075] A further embodiment of the present invention also discloses a control method for an air conditioner, which is used for the air conditioner as described in any of the above embodiments. Figure 7 FIG. 1 is a flow chart of a method for controlling an air conditioner according to an embodiment of the present invention. Figure 7 As shown, the method comprises the following steps:

[0076] Step S1: After the compressor starts running for a first preset time, the oil return control device is used to determine whether the separator outputs lubricating oil.

[0077] Step S2: Control the oil return control device according to the judgment result so that the lubricating oil output by the separator returns to the compressor through the oil return control device, or prevent the refrigerant from returning to the compressor through the oil return control device.

[0078] In one embodiment of the present invention, the first liquid channel and the second liquid channel are connected in parallel, the inlets of the first liquid channel and the second liquid channel are respectively connected to the oil outlet of the separator, and the outlets of the first liquid channel and the second liquid channel are respectively connected to the suction port of the compressor. When the compressor starts running for a first preset time, the oil return control device is used to determine whether the separator outputs lubricating oil, specifically including: determining whether the separator outputs lubricating oil by obtaining the temperature of the liquid flowing through the first liquid channel.

[0079] In one embodiment of the present invention, the control method of the air conditioner also includes: throttling and reducing the pressure of the refrigerant or lubricating oil flowing through the first pressure reducing device by a first pressure reducing device arranged on the first liquid channel; detecting the first temperature of the refrigerant or lubricating oil flowing into the inlet of the first pressure reducing device by a first temperature sensor arranged at the inlet of the first pressure reducing device; and detecting the second temperature of the refrigerant or lubricating oil flowing out of the outlet of the first pressure reducing device by a second temperature sensor arranged at the outlet of the first pressure reducing device.

[0080] In one embodiment of the present invention, the control method of the air conditioner further includes: throttling and reducing the pressure of the lubricating oil flowing through the second pressure reducing device by a second pressure reducing device disposed on the second liquid channel.

[0081] In one embodiment of the present invention, Figure 8 As shown, the process of judging whether the separator outputs lubricating oil by the oil return control device specifically includes: obtaining a first temperature and a second temperature; calculating the difference between the first temperature and the second temperature; when the difference is not greater than a preset temperature and the duration reaches a second preset time, judging that the separator outputs lubricating oil; when the difference is greater than the preset temperature and the duration reaches a third preset time, judging that the separator does not output lubricating oil.

[0082] In one embodiment of the present invention, Fig. 9 As shown, the process of controlling the oil return control device according to the judgment result specifically includes: when it is judged that the separator outputs lubricating oil, controlling the electromagnetic two-way valve to open so that the lubricating oil output by the separator returns to the compressor through the oil return control device; when it is judged that the separator does not output lubricating oil, controlling the electromagnetic two-way valve to close to prevent the refrigerant from returning to the compressor through the oil return control device, wherein the electromagnetic two-way valve is arranged on the second liquid channel, and the electromagnetic two-way valve is connected in series with the second pressure reducing device.

[0083] In one embodiment of the present invention, the first pressure reducing device, the second pressure reducing device and the throttling device are all one of a capillary tube, a throttling valve or an electronic expansion valve.

[0084] In one embodiment of the present invention, under the same pressure difference conditions, when the first pressure reducing device, the second pressure reducing device and the throttling device are all in the open state, the flow rate of the first pressure reducing device is smaller than the flow rate of the second pressure reducing device, and the flow rate of the second pressure reducing device is smaller than the flow rate of the throttling device.

[0085] In one embodiment of the present invention, the inlet and outlet of the separator are located at the top of the separator, and the oil outlet is located at the bottom of the separator.

[0086] It should be noted that when separating lubricating oil, the specific implementation method of the control method of the air conditioner in the embodiment of the present invention is similar to the specific implementation method of the air conditioner in the embodiment of the present invention. Please refer to the description of the air conditioner for details. In order to reduce redundancy, it will not be repeated here.

[0087] According to the control method of the air conditioner of the embodiment of the present invention, when the compressor starts to run for a first preset time, the oil return control device is used to determine whether the separator outputs lubricating oil, and the oil return control device is controlled according to the determination result, so that the lubricating oil output by the separator returns to the compressor through the oil return control device, or the refrigerant is prevented from returning to the compressor through the oil return control device, so as to prevent the precipitated lubricating oil from entering the throttling device so that the air conditioner cannot operate or its capacity is reduced, and at the same time, it can also prevent the compressor from being damaged due to lack of lubricating oil, and on the other hand, it can also prevent too much lubricating oil from entering the evaporator and affecting the heat exchange of the evaporator.

[0088] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" 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 present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example.

[0089] Although the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. An air conditioner, characterized in that: include: A refrigerant circulation loop, wherein the refrigerant performs a refrigeration cycle in a loop composed of a compressor, a condenser, a throttling device, and an evaporator, wherein one of the condenser and the evaporator is an outdoor heat exchanger and the other is an indoor heat exchanger; The throttling device is arranged between the condenser and the evaporator, and is used to increase the flow resistance of the refrigerant passing through the throttling device when the opening degree of the throttling device decreases, and to reduce the flow resistance of the refrigerant passing through the throttling device when the opening degree of the throttling device increases; A separator, the separator is arranged between the condenser and the throttling device, the separator comprises an inlet, an outlet and an oil outlet; wherein the inlet is connected to the outlet of the condenser, the outlet is connected to the throttling device, the oil outlet is connected to the oil return control device, the separator is used to separate the lubricating oil and the refrigerant in the high-temperature and high-pressure refrigerant liquid discharged from the condenser, and output the lubricating oil to the inlet of the oil return control device through the oil outlet, and output the refrigerant to the throttling device through the outlet; The oil return control device is arranged between the separator and the air inlet of the compressor, and is used to return the lubricating oil to the compressor through the outlet of the oil return control device when the separator outputs the lubricating oil; and to prevent the refrigerant from returning to the compressor through the outlet of the oil return control device when the separator does not output the lubricating oil; The controller is configured to: after the compressor starts running for a first preset time, determine through the oil return control device whether the separator outputs the lubricating oil, and control the oil return control device according to the determination result so that the lubricating oil output by the separator returns to the compressor through the oil return control device, or prevent the refrigerant from returning to the compressor through the oil return control device.

2. The air conditioner according to claim 1, characterized in that: The oil return control device comprises: a first liquid channel and a second liquid channel connected in parallel, wherein the inlets of the first liquid channel and the second liquid channel are respectively connected to the oil outlet of the separator, and the outlets of the first liquid channel and the second liquid channel are respectively connected to the air intake port of the compressor; The controller is configured to determine whether the separator outputs the lubricating oil by acquiring the temperature of the liquid flowing through the first liquid channel.

3. The air conditioner according to claim 2, characterized in that: The oil return control device comprises: a first pressure reducing device disposed on the first liquid channel, the first pressure reducing device being used to throttle and reduce the pressure of the refrigerant or the lubricating oil flowing through the first pressure reducing device; a first temperature sensor, the first temperature sensor being disposed at the inlet of the first pressure reducing device and being used to detect a first temperature of the refrigerant or the lubricating oil flowing into the inlet of the first pressure reducing device; A second temperature sensor is disposed at the outlet of the first pressure reducing device and is used to detect a second temperature of the refrigerant or the lubricating oil flowing out of the outlet of the first pressure reducing device.

4. The air conditioner according to claim 3, characterized in that: The oil return control device comprises: a second pressure reducing device provided on the second liquid passage, the second pressure reducing device being used for throttling and reducing the pressure of the lubricating oil flowing through the second pressure reducing device; An electromagnetic two-way valve is arranged on the second liquid passage, and the electromagnetic two-way valve is connected in series with the second pressure reducing device.

5. The air conditioner according to claim 4, characterized in that: When judging whether the separator outputs the lubricating oil through the oil return control device, the controller is specifically configured as follows: acquiring the first temperature and the second temperature; calculating a difference between the first temperature and the second temperature; When the difference is not greater than the preset temperature and the duration reaches a second preset time, it is determined that the separator outputs the lubricating oil; When the difference is greater than the preset temperature and the duration reaches a third preset time, it is determined that the separator does not output the lubricating oil.

6. The air conditioner according to claim 5, characterized in that: When the oil return control device is controlled according to the judgment result, the controller is specifically configured as follows: When it is determined that the separator outputs the lubricating oil, the electromagnetic two-way valve is controlled to open, so that the lubricating oil output by the separator returns to the compressor through the oil return control device; When it is determined that the separator does not output the lubricating oil, the electromagnetic two-way valve is controlled to be closed to prevent the refrigerant from returning to the compressor through the oil return control device.

7. The air conditioner according to claim 4, characterized in that: The first pressure reducing device, the second pressure reducing device and the throttling device are all one of a capillary tube, a throttling valve or an electronic expansion valve.

8. The air conditioner according to claim 4, characterized in that: Under the same pressure difference conditions, when the first pressure reducing device, the second pressure reducing device and the throttling device are all in the open state, the flow rate of the first pressure reducing device is smaller than the flow rate of the second pressure reducing device, and the flow rate of the second pressure reducing device is smaller than the flow rate of the throttling device.

9. The air conditioner according to claim 1, characterized in that: The inlet and outlet of the separator are located at the top of the separator, and the oil outlet is located at the bottom of the separator.

10. A method for controlling an air conditioner, characterized in that: For the air conditioner according to any one of claims 1 to 9, the method comprises the following steps: After the compressor starts to run for a first preset time, the oil return control device determines whether the separator outputs lubricating oil; The oil return control device is controlled according to the judgment result so that the lubricating oil output by the separator returns to the compressor through the oil return control device, or the refrigerant is prevented from returning to the compressor through the oil return control device.

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