Gas-liquid separator, air conditioner and control method of air conditioner

Abstract

The present application relates to the field of air conditioners, and specifically provides a gas-liquid separator, an air conditioner and a control method of the air conditioner, aiming to solve the problem of how to ensure the oil return reliability and avoid the phenomenon of liquid strike under certain working conditions to cause damage to the compressor. To this end, the gas-liquid separator of the present application comprises: a cavity, which is provided with an air inlet, an air outlet and a first oil return port, the air outlet is used to be connected with the suction port of the compressor, and a throttling element is arranged on the passage between the first oil return port and the suction port; a first air outlet pipe is arranged in the cavity, which is provided with a second oil return port, and the air outlet end is connected with the air outlet; a second air outlet pipe is arranged in the cavity, and the air outlet end is connected with the air outlet; a first valve body is used to control the connection and block between the first air outlet pipe and the air outlet; and a second valve body is used to control the connection and block between the first oil return port and the suction port.

Description

Technical Field

[0001] This invention relates to the field of air conditioning, and specifically provides a gas-liquid separator, an air conditioner, and a control method for the air conditioner. Background Technology

[0002] Traditional gas-liquid separators have an oil return port on the outlet pipe. Due to the different densities and boiling points of the refrigerant and refrigeration oil, they separate into layers within the separator. The liquid refrigerant oil then enters the outlet pipe through the oil return port and is carried back to the compressor by the flow of the gaseous refrigerant, ensuring reliable oil return. However, under certain extreme conditions, there may be a large amount of refrigerant inside the gas-liquid separator. In such cases, directly using the conventional oil return method can cause the liquid refrigerant to flow into the compressor along with the compressor oil, carried by the gaseous refrigerant, leading to liquid slugging and compressor damage.

[0003] Accordingly, there is a need in the art for a new gas-liquid separator, an air conditioner, and a control method for the air conditioner to solve the above problems. Summary of the Invention

[0004] The present invention aims to solve the above-mentioned technical problems, namely, how to ensure the reliability of oil return in air conditioners while avoiding the damage to the compressor caused by liquid slugging under certain operating conditions.

[0005] In a first aspect, the present invention provides a gas-liquid separator, characterized in that the gas-liquid separator comprises: a cavity having an inlet, an outlet, and a first oil return port, the outlet being connected to the suction port of a compressor, and a throttling element being provided in the passage between the first oil return port and the suction port; a first outlet pipe disposed within the cavity, having a second oil return port, and the outlet end of the first outlet pipe being connected to the outlet; a second outlet pipe disposed within the cavity, the outlet end of the second outlet pipe being connected to the outlet; a first valve body for controlling the connection and disconnection between the first outlet pipe and the outlet; and a second valve body for controlling the connection and disconnection between the first oil return port and the suction port.

[0006] By employing the above technical solution, the present invention can control the connection and disconnection between the first exhaust pipe and the exhaust port, and between the first oil return port and the intake port. This allows for selective use of either an oil return mode via the first exhaust pipe or a mode where oil is returned via the oil return pipe and refrigerant is transported via the second exhaust pipe. This ensures both the reliability of the air conditioner's operation and avoids liquid slugging during the oil return process under extreme operating conditions.

[0007] In the preferred embodiment of the gas-liquid separator described above, the gas-liquid separator further includes a third valve body, which is used to control the connection and disconnection between the second gas outlet pipe and the gas outlet.

[0008] By adopting the above technical solution, it can be ensured that the compressor oil in the first outlet pipe returns to the compressor's driving force, thus avoiding abnormal oil return.

[0009] In the preferred embodiment of the above-mentioned gas-liquid separator, the gas-liquid separator includes a common pipe section. The first gas outlet pipe includes a horizontal pipe section and a vertical pipe section. One end of the vertical pipe section is connected to one end of the horizontal pipe section. The other end of the horizontal pipe section is the gas outlet end of the first gas outlet pipe. The gas outlet ends of the first gas outlet pipe and the gas outlet ends of the second gas outlet pipe are connected to the gas outlet through the common pipe section. The second oil return port is located on the horizontal pipe section.

[0010] In the preferred embodiment of the gas-liquid separator described above, the second gas outlet pipe is arranged in a vertical direction.

[0011] In the preferred embodiment of the above-mentioned gas-liquid separator, the gas outlet is located on the top wall of the cavity; and / or the first oil return port is located on the bottom wall of the cavity.

[0012] In the preferred embodiment of the above-mentioned gas-liquid separator, the first valve body is a first solenoid valve, the third valve body is a third solenoid valve, the first solenoid valve is located on the horizontal pipe section between the second oil return port and the second gas outlet pipe, and the third solenoid valve is located on the second gas outlet pipe; and / or the second valve body is a second solenoid valve; or the first valve body and the third valve body together constitute a three-way valve, and the gas outlet end of the first gas outlet, the gas outlet end of the second gas outlet pipe and the common pipe section are connected through the three-way valve.

[0013] In another aspect, the present invention also provides an air conditioner that includes a compressor and a gas-liquid separator as described in any of the above embodiments.

[0014] In another aspect, the present invention also provides a control method for an air conditioner, the air conditioner including a compressor, a gas-liquid separator, and a temperature sensor, the temperature sensor being used to detect ambient temperature, the gas-liquid separator including: a cavity having an air inlet, an air outlet, and a first oil return port, the air outlet being connected to the compressor's suction port, and a throttling device being provided in the passage between the first oil return port and the suction port; a first air outlet pipe disposed within the cavity, the first air outlet pipe having a second oil return port, the air outlet end of the first air outlet pipe being connected to the air outlet; a second air outlet pipe disposed within the cavity, the air outlet end of the second air outlet pipe being connected to the air outlet; a first valve body for controlling the connection and disconnection between the first air outlet pipe and the air outlet; and a second valve body for controlling the connection and disconnection between the first oil return port and the suction port; the control method including: acquiring the ambient temperature after the air conditioner is turned on; and controlling the operation of the first valve body and the second valve body based on the ambient temperature.

[0015] By adopting the above technical solution, the connection between the first air outlet pipe and the air outlet, and the connection between the first oil return port and the air intake port can be controlled based on the ambient temperature. In other words, the ambient temperature determines whether to use the oil return mode via the first air outlet pipe or the oil return mode. This ensures the reliability of the air conditioner's operation while avoiding liquid slugging during the oil return process under extreme operating conditions.

[0016] In the preferred embodiment of the control method for the air conditioner described above, the step of "controlling the operation of the first valve body and the second valve body based on the ambient temperature" further includes: when the ambient temperature is greater than a first preset temperature, controlling the connection between the first air outlet pipe and the air outlet through the first valve body, and controlling the blockage between the first oil return port and the air intake port through the second valve body.

[0017] In the preferred embodiment of the control method for the above-mentioned air conditioner, the step of "controlling the operation of the first valve body and the second valve body based on the ambient temperature" further includes: when the ambient temperature is less than or equal to a first preset temperature and greater than a second preset temperature, before, simultaneously or after the compressor is started, and / or when the ambient temperature is less than or equal to the second preset temperature, controlling the connection between the first oil return port and the air intake port through the second valve body; controlling the blockage between the first air outlet pipe and the air outlet through the first valve body.

[0018] In the preferred embodiment of the control method for the above-mentioned air conditioner, the step of "controlling the operation of the first valve body and the second valve body based on the ambient temperature" further includes: when the ambient temperature is less than or equal to a first preset temperature and greater than a second preset temperature, after the compressor exits the start-up phase, the first valve body controls the connection between the first air outlet pipe and the air outlet, and the second valve body controls the blockage between the first oil return port and the air intake port.

[0019] In the preferred embodiment of the control method for the above-mentioned air conditioner, the gas-liquid separator further includes a third valve body, which is used to control the connection and blockage between the second air outlet pipe and the air outlet; the step of "controlling the connection between the first air outlet pipe and the air outlet through the first valve body and controlling the blockage between the first oil return port and the air intake port through the second valve body" further includes: when the ambient temperature is greater than the first preset temperature, controlling the connection between the first air outlet pipe and the air outlet through the first valve body, controlling the blockage between the first oil return port and the air intake port through the second valve body, and controlling the blockage between the second air outlet pipe and the air outlet through the third valve body.

[0020] In a preferred embodiment of the control method for the aforementioned air conditioner, the gas-liquid separator further includes a third valve body, which is used to control the connection and disconnection between the second outlet pipe and the outlet. The step of "controlling the connection between the first oil return port and the suction port through the second valve body when the ambient temperature is less than or equal to a first preset temperature and greater than a second preset temperature, before, simultaneously with, or after the compressor starts, and / or when the ambient temperature is less than or equal to the second preset temperature; controlling the disconnection between the first outlet pipe and the outlet through the first valve body" further includes: controlling the connection between the first oil return port and the suction port through the second valve body when the ambient temperature is less than or equal to a first preset temperature and greater than a second preset temperature, before, simultaneously with, or after the compressor starts, and / or when the ambient temperature is less than or equal to the second preset temperature; controlling the disconnection between the first outlet pipe and the outlet through the first valve body; and controlling the connection between the second outlet pipe and the outlet through the third valve body.

[0021] In the preferred embodiment of the control method for the above-mentioned air conditioner, the gas-liquid separator further includes a third valve body, which is used to control the connection and blockage between the second outlet pipe and the outlet. The step of "when the ambient temperature is less than or equal to the first preset temperature and greater than the second preset temperature, after the compressor exits the start-up stage, controlling the connection between the first outlet pipe and the outlet through the first valve body, and controlling the blockage between the first oil return port and the suction port through the second valve body" further includes: when the ambient temperature is less than or equal to the first preset temperature and greater than the second preset temperature, after the compressor exits the start-up stage, controlling the connection between the first outlet pipe and the outlet through the first valve body, controlling the blockage between the first oil return port and the suction port through the second valve body, and controlling the blockage between the second outlet pipe and the outlet through the third valve body.

[0022] Option 1: A gas-liquid separator, characterized in that the gas-liquid separator comprises: a cavity, wherein the cavity is provided with an air inlet, an air outlet, and a first oil return port, the air outlet being connected to the suction port of a compressor, and a throttling device being provided in the passage between the first oil return port and the suction port; a first air outlet pipe, wherein the first air outlet pipe is disposed in the cavity, and the first air outlet pipe is provided with a second oil return port, the air outlet end of the first air outlet pipe being connected to the air outlet; a second air outlet pipe, wherein the second air outlet pipe is disposed in the cavity, and the air outlet end of the second air outlet pipe being connected to the air outlet; a first valve body, wherein the first valve body is used to control the connection and disconnection between the first air outlet pipe and the air outlet; and a second valve body, wherein the second valve body is used to control the connection and disconnection between the first oil return port and the suction port.

[0023] Option 2: The gas-liquid separator according to Option 1, characterized in that the gas-liquid separator further includes a third valve body, the third valve body being used to control the connection and blockage between the second gas outlet pipe and the gas outlet.

[0024] Option 3: The gas-liquid separator according to Option 2, characterized in that the gas-liquid separator includes a common pipe section, the first gas outlet pipe includes a horizontal pipe section and a vertical pipe section, the vertical pipe section is connected to one end of the horizontal pipe section, the other end of the horizontal pipe section is the gas outlet end of the first gas outlet pipe, the gas outlet end of the first gas outlet pipe and the gas outlet end of the second gas outlet pipe are connected to the gas outlet through the common pipe section, and the second oil return port is provided on the horizontal pipe section.

[0025] Option 4: The gas-liquid separator according to Option 3, characterized in that the second gas outlet pipe is arranged in a vertical direction.

[0026] Option 5: The gas-liquid separator according to Option 1, characterized in that the gas outlet is located on the top wall of the cavity; and / or the first oil return port is located on the bottom wall of the cavity.

[0027] Option 6: The gas-liquid separator according to Option 3, characterized in that the first valve body is a first solenoid valve, the third valve body is a third solenoid valve, the first solenoid valve is disposed on a horizontal pipe section between the second oil return port and the second gas outlet pipe, and the third solenoid valve is disposed on the second gas outlet pipe; and / or the second valve body is a second solenoid valve; or the first valve body and the third valve body together constitute a three-way valve, and the gas outlet end of the first gas outlet, the gas outlet end of the second gas outlet pipe and the common pipe section are connected through the three-way valve.

[0028] Option 7: An air conditioner, characterized in that the air conditioner includes a compressor, and the air conditioner further includes a gas-liquid separator as described in any one of Options 1 to 6.

[0029] Option 8: A control method for an air conditioner, characterized in that the air conditioner includes a compressor, a gas-liquid separator, and a temperature sensor, the temperature sensor being used to detect ambient temperature, the gas-liquid separator including: a cavity having an air inlet, an air outlet, and a first oil return port, the air outlet being connected to the compressor's suction port, and a throttling device being provided in the passage between the first oil return port and the suction port; a first air outlet pipe located within the cavity, having a second oil return port, the air outlet end of the first air outlet pipe being connected to the air outlet; a second air outlet pipe located within the cavity, the air outlet end of the second air outlet pipe being connected to the air outlet; a first valve body used to control the connection and disconnection between the first air outlet pipe and the air outlet; and a second valve body used to control the connection and disconnection between the first oil return port and the suction port; the control method including: acquiring the ambient temperature after the air conditioner is activated; and controlling the operation of the first valve body and the second valve body based on the ambient temperature.

[0030] Scheme 9, the control method of the air conditioner according to Scheme 8, is characterized in that the step of "controlling the operation of the first valve body and the second valve body based on the ambient temperature" further includes: when the ambient temperature is greater than the first preset temperature, controlling the connection between the first air outlet pipe and the air outlet through the first valve body, and controlling the blockage between the first oil return port and the air intake port through the second valve body.

[0031] Scheme 10: The control method for the air conditioner according to Scheme 8, characterized in that the step of "controlling the operation of the first valve body and the second valve body based on the ambient temperature" further includes: when the ambient temperature is less than or equal to a first preset temperature and greater than a second preset temperature, before, simultaneously or after the compressor starts, and / or when the ambient temperature is less than or equal to the second preset temperature, controlling the connection between the first oil return port and the air intake port through the second valve body; controlling the blockage between the first air outlet pipe and the air outlet through the first valve body.

[0032] Scheme 11: The control method for the air conditioner according to Scheme 10 is characterized in that the step of "controlling the operation of the first valve body and the second valve body based on the ambient temperature" further includes: when the ambient temperature is less than or equal to a first preset temperature and greater than a second preset temperature, after the compressor exits the start-up phase, the first valve body controls the connection between the first air outlet pipe and the air outlet, and the second valve body controls the blockage between the first oil return port and the air intake port.

[0033] Scheme 12, the control method for the air conditioner according to Scheme 9, characterized in that the gas-liquid separator further includes a third valve body, the third valve body being used to control the connection and blockage between the second air outlet pipe and the air outlet; the step of "when the ambient temperature is greater than the first preset temperature, controlling the connection between the first air outlet pipe and the air outlet through the first valve body, and controlling the blockage between the first oil return port and the air intake port through the second valve body" further includes: when the ambient temperature is greater than the first preset temperature, controlling the connection between the first air outlet pipe and the air outlet through the first valve body, controlling the blockage between the first oil return port and the air intake port through the second valve body, and controlling the blockage between the second air outlet pipe and the air outlet through the third valve body.

[0034] Scheme 13: The control method for the air conditioner according to Scheme 10, characterized in that the gas-liquid separator further includes a third valve body, the third valve body being used to control the connection and blockage between the second outlet pipe and the outlet; the step of "controlling the connection between the first oil return port and the suction port through the second valve body when the ambient temperature is less than or equal to a first preset temperature and greater than a second preset temperature, before, simultaneously or after the compressor starts, and / or when the ambient temperature is less than or equal to the second preset temperature; controlling the blockage between the first outlet pipe and the outlet through the first valve body" further includes: controlling the connection between the first oil return port and the suction port through the second valve body when the ambient temperature is less than or equal to a first preset temperature and greater than a second preset temperature, before, simultaneously or after the compressor starts, and / or when the ambient temperature is less than or equal to the second preset temperature; controlling the blockage between the first outlet pipe and the outlet through the first valve body; controlling the connection between the second outlet pipe and the outlet through the third valve body.

[0035] Scheme 14: The control method for the air conditioner according to Scheme 11, characterized in that the gas-liquid separator further includes a third valve body, the third valve body being used to control the connection and blockage between the second outlet pipe and the outlet; the step of "when the ambient temperature is less than or equal to a first preset temperature and greater than a second preset temperature, after the compressor exits the start-up phase, controlling the connection between the first outlet pipe and the outlet through the first valve body, and controlling the blockage between the first oil return port and the suction port through the second valve body" further includes: when the ambient temperature is less than or equal to a first preset temperature and greater than a second preset temperature, after the compressor exits the start-up phase, controlling the connection between the first outlet pipe and the outlet through the first valve body, controlling the blockage between the first oil return port and the suction port through the second valve body, and controlling the blockage between the second outlet pipe and the outlet through the third valve body. Attached Figure Description

[0036] The preferred embodiments of the present invention are described below with reference to the accompanying drawings, in which:

[0037] Figure 1 This is a schematic diagram of the structure of the air conditioner of the present invention;

[0038] Figure 2 This is the main flowchart of the control method for the air conditioner of the present invention;

[0039] Figure 3 This is a possible logic diagram of the control method for the air conditioner of the present invention.

[0040] List of reference numerals in the attached diagram:

[0041] 1-Compressor; 2-Outdoor heat exchanger; 3-Throttle valve; 4-Indoor heat exchanger; 5-Four-way reversing valve; 6-Gas-liquid separator; 61-Cavity; 611-Inlet; 612-Outlet; 613-First oil return port; 62-Inlet pipe; 63-Oil return pipe; 64-Throttle element; 65-First outlet pipe; 651-Horizontal pipe section; 6511-Second oil return port; 652-Vertical pipe section; 66-Second outlet pipe; 67-First valve body; 68-Second valve body; 69-Third valve body; 60-Common pipe section. Detailed Implementation

[0042] Preferred embodiments of the present invention will now be described with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are merely illustrative of the technical principles of the invention and are not intended to limit the scope of protection of the invention. Those skilled in the art can make adjustments as needed to adapt to specific applications.

[0043] It should be noted that, in the description of this invention, unless otherwise explicitly specified and limited, the terms "connection" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances. Furthermore, in the description of this invention, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0044] like Figure 1As shown, the air conditioner of the present invention includes a refrigerant circuit, on which a compressor 1, an outdoor heat exchanger 2, a throttle valve 3, and an indoor heat exchanger 4 are sequentially arranged. Possibly, the air conditioner of the present invention also includes a four-way reversing valve 5, which is used to change the refrigerant flow direction in the refrigerant circuit to realize the switching between cooling and heating modes. That is, the four-way reversing valve 5 is connected to the suction port of the compressor 1, the discharge port of the compressor 1, the indoor heat exchanger 4, and the outdoor heat exchanger 2, respectively. The air conditioner of the present invention also includes a gas-liquid separator 6, which includes a cavity 61. The cavity 61 is provided with an air inlet 611, an air outlet 612 and a first oil return port 613. The air inlet 611 and the air outlet 612 can both be provided on the top wall of the cavity 61. An air inlet pipe 62 is connected to the air inlet 611. One end of the air inlet pipe 62 extends into the cavity 61 and the other end extends out of the cavity 61 and is connected to a four-way reversing valve 5. The air outlet 612 can be connected to the suction port of the compressor 1 through a refrigerant branch pipe. The first oil return port 613 can be provided on the bottom wall of the cavity 61. The first oil return port 613 is connected to the suction port of the compressor 1 through an oil return pipe 63. A throttling element 64 is provided on the oil return pipe 63. The throttling element 64 is preferably a capillary tube. In cooling mode, the four-way reversing valve 5 is controlled to perform a first action, causing the refrigerant flowing from compressor 1 to flow sequentially through outdoor heat exchanger 2, throttle valve 3, and indoor heat exchanger 4 into the intake pipe 62. After gas-liquid separation by gas-liquid separator 6, it returns to compressor 1. In heating mode, the four-way reversing valve 5 is controlled to perform a second action, causing the refrigerant flowing from compressor 1 to flow sequentially through indoor heat exchanger 4, throttle valve 3, and outdoor heat exchanger 2 into the intake pipe 62. After gas-liquid separation by gas-liquid separator 6, it returns to compressor 1. Of course, the positions of the aforementioned intake port 611, outlet port 612, and first oil return port 613 are not fixed. For example, the intake port 611 and outlet port 612 can both be located on the upper part of the side wall of cavity 61, and the first oil return port 613 can be located at the bottom of the side wall of cavity 61, etc.

[0045] Those skilled in the art will understand that the outdoor unit of the air conditioner includes the compressor 1, outdoor heat exchanger 2, and outdoor fan mentioned above; the indoor unit of the air conditioner includes the indoor heat exchanger 4 and indoor fan mentioned above, and a throttling valve 3 (such as a capillary tube or electronic expansion valve) can be provided in the indoor unit or the outdoor unit.

[0046] The gas-liquid separator 6 of the present invention further includes a first outlet pipe 65, a second outlet pipe 66, a first valve body 67, and a second valve body 68. The first outlet pipe 65 and the second outlet pipe 66 are disposed within the cavity 61. The first outlet pipe 65 is provided with a second oil return port 6511. The outlet ends of both the first outlet pipe 65 and the second outlet pipe 66 are connected to the outlet port 612. The first valve body 67 is used to control the connection and disconnection between the first outlet pipe 65 and the outlet port 612, and the second valve body 68 is used to control the connection and disconnection between the first oil return port 613 and the suction port. When the first valve body 67 controls the connection between the first outlet pipe 65 and the outlet port 612, the compressor oil in the cavity 61 will enter the first outlet pipe 65 through the second oil return port 6511, and then enter the compressor 1 through the outlet port 612 under the action of the refrigerant, thus achieving normal oil return. In this oil return method, since the power for oil return in the compressor 1 comes from the refrigerant circulation, the reliability of system operation can be achieved. When the second valve body 68 controls the connection between the first oil return port 613 and the suction port, the compressor oil will enter the oil return pipe 63 through the first oil return port 613. After being throttled by the throttling device 64, the liquid refrigerant becomes gaseous refrigerant and returns to the compressor 1. This allows for oil return through the oil return pipe 63 under extreme operating conditions, avoiding liquid slugging during the oil return process. At the same time, the refrigerant can flow into the compressor 1 through the second outlet pipe 66, thereby achieving refrigerant circulation.

[0047] In one possible implementation, the gas-liquid separator 6 of the present invention further includes a third valve body 69, which is used to control the connection and disconnection between the second outlet pipe 66 and the outlet 612. This arrangement allows for oil return during conventional oil return by controlling the disconnection between the second outlet pipe 66 and the outlet 612 via the third valve body 69, ensuring oil return only through the first outlet pipe 65 with the second oil return port 6511. Since the second outlet pipe 66 is an empty cavity without an oil return port, if the second outlet pipe 66 and the outlet 612 are connected during conventional oil return, there is no liquid flow obstruction in the second outlet pipe 66, resulting in very low flow resistance. More refrigerant will return to the compressor 1 through the second outlet pipe 66, reducing the power required to drive the compressor oil in the first outlet pipe 65 back to the compressor 1. Therefore, this arrangement avoids abnormal oil return during conventional oil return.

[0048] In one possible implementation, the gas-liquid separator 6 includes a common pipe section 60. The first outlet pipe 65 includes a horizontal pipe section 651 and a vertical pipe section 652. That is, the horizontal pipe section 651 is arranged along the horizontal direction of the cavity 61, and the vertical pipe section 652 is arranged along the vertical direction of the cavity 61. One end of the vertical pipe section 652 is connected to one end of the horizontal pipe section 651, and the other end of the horizontal pipe section 651 is the outlet end of the first outlet pipe 65. The outlet end of the first outlet pipe 65 and the outlet end of the second outlet pipe 66 are connected to the outlet port 612 through the common pipe section 60. The second oil return port 6511 is provided on the horizontal pipe section 651. Possibly, the second outlet pipe 66 is arranged in the vertical direction. The first vent pipe 65 and the second vent pipe 66 form a U-shaped structure; the common pipe section 60 can be L-shaped, with one end connected to the vent end of the first vent pipe 65 and the vent end of the second vent pipe 66, and the other end connected to the vent 612.

[0049] The first valve body 67, the second valve body 68, and the third valve body 69 can all be solenoid valves. For ease of distinction, the first valve body 67 is referred to as the first solenoid valve 67, the second valve body 68 as the second solenoid valve 68, and the third valve body 69 as the third solenoid valve 69. The first solenoid valve 67 is located on the horizontal pipe section 651 between the second oil return port 6511 and the second air outlet pipe 66. The third solenoid valve 69 is located on the second air outlet pipe 66. The second solenoid valve 68 can be located on the oil return pipe 63, or it can be located on the first oil return port 613, etc. Of course, the above description is not restrictive. As long as the first valve body 67 can control the connection and disconnection between the first exhaust pipe 65 and the exhaust port 612, the second valve body 68 can control the connection and disconnection between the first return port 613 and the intake port, and the third valve body 69 can control the connection and disconnection between the second exhaust pipe 66 and the exhaust port 612, the specific configuration can be adjusted. For example, the first valve body 67 and the third valve body 69 together form a three-way valve, and the exhaust ends of the first exhaust pipe 65 and the second exhaust pipe 66 are connected to the common pipe section 60 through the three-way valve. Thus, the three-way valve realizes the connection between the first exhaust pipe 65 and the common pipe section 60, and the disconnection between the second exhaust pipe 66 and the common pipe section 60; or it realizes the disconnection between the first exhaust pipe 65 and the common pipe section 60, and the connection between the second exhaust pipe 66 and the common pipe section 60, etc. With the above-mentioned solenoid valve configuration, the structure can be simplified, the response can be fast, and the reliability can be improved.

[0050] After the refrigerant enters the cavity 61 through the inlet pipe 62, it will boil at a very low temperature and separate into layers in the gas-liquid separator 6. The upper layer is gaseous refrigerant. Since the vertical pipe section 652 of the first outlet pipe 65 and the second outlet pipe 66 are both arranged vertically, that is, the inlet end of the first outlet pipe 65 and the inlet end of the second outlet pipe 66 are both located in the upper part of the cavity 61, the upper gaseous refrigerant can enter the first outlet pipe 65 and the second outlet pipe 66. The horizontal pipe section 651 is located in the compressor oil. The compressor oil can enter the horizontal pipe section 651 through the second oil return port 6511 on the horizontal pipe section 651 and then return to the compressor 1.

[0051] In one possible implementation, the air conditioner of the present invention further includes a temperature sensor for detecting the ambient temperature. For example, the temperature sensor may be disposed on the housing of the outdoor unit, which includes the outdoor heat exchanger 2, or at the air inlet of the outdoor unit.

[0052] like Figure 2 As shown, the present invention also provides a control method for an air conditioner, the control method comprising the following steps:

[0053] Step S100: After the air conditioner is turned on, obtain the ambient temperature.

[0054] In other words, the ambient temperature is obtained through a temperature sensor after the air conditioner is turned on.

[0055] Step S200: Control the operation of the first valve body and the second valve body based on the ambient temperature.

[0056] Since the ambient temperature is directly related to the amount of liquid refrigerant in the gas-liquid separator, the operation of the first and second valve bodies is controlled based on the ambient temperature. This means controlling the connection between the first outlet pipe and the outlet port, and the connection between the first oil return port and the suction port. In other words, the ambient temperature determines whether to use the oil return mode through the first outlet pipe or the oil return pipe. This ensures the reliability of the air conditioner while preventing liquid slugging during the oil return process under extreme operating conditions.

[0057] For ease of explanation, the first valve body of the present invention will be described below as a first solenoid valve, the second valve body as a second solenoid valve, and the third valve body as a third solenoid valve.

[0058] Step S200 further includes:

[0059] Step S201: When the ambient temperature is higher than the first preset temperature, control the first solenoid valve to open, control the second solenoid valve to close, and control the third solenoid valve to close.

[0060] The first preset temperature can be determined experimentally, by formula, or empirically. For example, the range of the first preset temperature is 4-6 degrees Celsius, preferably 5 degrees Celsius. When the ambient temperature is higher than the first preset temperature, there will not be much liquid refrigerant in the gas-liquid separator. In this case, a conventional oil return mode can be used. By controlling the first solenoid valve to open, the second solenoid valve to close, and the third solenoid valve to close, the gaseous refrigerant first enters only the first outlet pipe, and the compressor oil enters the first outlet pipe through the second oil return port. Driven by the refrigerant, the compressor oil returns to the compressor. Controlling the third solenoid valve to close ensures that there is sufficient power in the first outlet pipe to drive the flow of compressor oil, ensuring normal oil return of the air conditioner.

[0061] Step S202: When the ambient temperature is less than or equal to the first preset temperature and greater than the second preset temperature, before, simultaneously with or after the compressor starts, control the second solenoid valve to open, control the first solenoid valve to close, and control the third solenoid valve to open.

[0062] The second preset temperature can be determined experimentally, by formula, or empirically. For example, the second preset temperature could be 0 degrees Celsius. When the ambient temperature is less than or equal to the first preset temperature but greater than the second preset temperature, at the moment the compressor starts, the compressor oil and refrigerant at the bottom of the chamber are mixed, with a higher proportion of liquid refrigerant. In this case, an oil return pipe is used, i.e., the second solenoid valve is opened, the first solenoid valve is closed, and the third solenoid valve is opened. This ensures that the gaseous refrigerant only enters the second outlet pipe and then returns to the compressor. The compressor oil and liquid refrigerant enter the oil return pipe through the first oil return port and simultaneously enter the capillary tube, increasing the flow resistance and throttling the refrigerant into a gaseous state. This avoids liquid slugging during the oil return process and ensures normal compressor startup.

[0063] Step S203: When the ambient temperature is less than or equal to the first preset temperature and greater than the second preset temperature, after the compressor exits the start-up phase, control the first solenoid valve to open, control the second solenoid valve to close, and control the third solenoid valve to close.

[0064] When the compressor starts, it will be forced to increase its frequency, meaning the compressor frequency will continuously rise. Once it reaches a preset frequency, such as 50-60Hz, the compressor will exit the startup phase. After the compressor exits the startup phase, the refrigerant in the gas-liquid separator will enter the indoor unit, and the amount of refrigerant in the gas-liquid separator will decrease to a normal level. In this case, the first solenoid valve opens, the second solenoid valve closes, and the third solenoid valve closes, meaning that oil returns only through the first outlet pipe, ensuring the reliability of the air conditioner's operation.

[0065] Step S204: When the ambient temperature is less than or equal to the second preset temperature, control the second solenoid valve to open, control the first solenoid valve to close, and control the third solenoid valve to open.

[0066] At this point, the ambient temperature is already extremely low. Under these circumstances, the oil return pipe is used directly to return the oil. This involves controlling the second solenoid valve to open, the first solenoid valve to close, and the third solenoid valve to open, thus preventing liquid slugging from occurring during the oil return process in the air conditioner.

[0067] like Figure 3 As shown, in one specific implementation, the control method of the present invention includes:

[0068] Step S301: After the air conditioner is turned on, obtain the ambient temperature Tao.

[0069] Step S302: When Tao > 5℃, control the first solenoid valve to open, control the second solenoid valve to close, and control the third solenoid valve to close.

[0070] Step S303: When 5℃≥Tao>0℃, before the compressor starts, control the second solenoid valve to open, control the first solenoid valve to close, and control the third solenoid valve to open.

[0071] Step S304: When 5℃≥Tao>0℃, after the compressor exits the start-up phase, control the first solenoid valve to open, control the second solenoid valve to close, and control the third solenoid valve to close.

[0072] Step S305: When 0℃≥Tao, control the second solenoid valve to open, control the first solenoid valve to close, and control the third solenoid valve to open.

[0073] The air conditioner and its control method of the present invention prevent liquid refrigerant from flowing into the compressor along with the compressor oil under the influence of gaseous refrigerant, thus avoiding liquid slugging and damage to the compressor, in extreme operating conditions such as low temperature and ultra-low temperature heating, where the ambient temperature is low and the load is small (the machine is not turned on for a long time or the number of machines turned on is small) and there is a lot of refrigerant inside the gas-liquid separator.

[0074] Those skilled in the art will understand that the aforementioned air conditioner also includes other well-known structures, such as processors, controllers, and memories. These memories include, but are not limited to, random access memory (RAM), flash memory, read-only memory (ROM), programmable read-only memory (PROM), volatile memory, non-volatile memory, serial memory, parallel memory, or registers. Processors include, but are not limited to, CPLD / FPGA, DSP, ARM processors, and MIPS processors. To avoid unnecessarily obscuring the embodiments of this disclosure, these well-known structures are not shown in the accompanying drawings.

[0075] The technical solution of the present invention has been described above with reference to the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of the present invention is obviously not limited to these specific embodiments. Without departing from the principles of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after such changes or substitutions will all fall within the scope of protection of the present invention.

Claims

1. A gas-liquid separator characterized by, The gas-liquid separator comprises: a cavity, which is provided with an air inlet, an air outlet and a first oil return port, the air outlet is connected with a suction port of a compressor, a throttling element is arranged in a passage between the first oil return port and the suction port; a first air outlet pipe, which is arranged in the cavity, and is provided with a second oil return port, and an air outlet end of the first air outlet pipe is connected with the air outlet; a second air outlet pipe, which is arranged in the cavity, and an air outlet end of the second air outlet pipe is connected with the air outlet; a first valve body, which is used for controlling the connection and blockage between the first air outlet pipe and the air outlet; a second valve body, which is used for controlling the connection and blockage between the first oil return port and the suction port; The gas-liquid separator comprises a common pipe section, the first air outlet pipe comprises a horizontal pipe section and a vertical pipe section, the vertical pipe section is connected with one end of the horizontal pipe section, the other end of the horizontal pipe section is the air outlet end of the first air outlet pipe, the air outlet end of the first air outlet pipe and the air outlet end of the second air outlet pipe are connected with the air outlet through the common pipe section, and the second oil return port is arranged on the horizontal pipe section.

2. The gas-liquid separator according to claim 1, wherein The gas-liquid separator further comprises a third valve body, which is used for controlling the connection and blockage between the second air outlet pipe and the air outlet.

3. The gas-liquid separator according to claim 1, wherein The second air outlet pipe is arranged in a vertical direction.

4. The gas-liquid separator according to claim 1, wherein The air outlet is arranged on a top wall of the cavity; and / or The first oil return port is arranged on a bottom wall of the cavity.

5. The gas-liquid separator according to claim 2, wherein The first valve body is a first electromagnetic valve, the third valve body is a third electromagnetic valve, the first electromagnetic valve is arranged on the horizontal pipe section between the second oil return port and the second air outlet pipe, and the third electromagnetic valve is arranged on the second air outlet pipe; and / or The second valve body is a second electromagnetic valve; or The first valve body and the third valve body jointly constitute a three-way valve, and the air outlet end of the first air outlet end, the air outlet end of the second air outlet pipe and the common pipe section are connected through the three-way valve.

6. An air conditioner characterized by comprising: The air conditioner comprises a compressor, and further comprises the gas-liquid separator according to any one of claims 1 to 5.

7. A control method of an air conditioner, characterized by, The air conditioner comprises a compressor, a gas-liquid separator and a temperature sensor, the temperature sensor is used for detecting an ambient temperature, and the gas-liquid separator comprises: a cavity, which is provided with an air inlet, an air outlet and a first oil return port, the air outlet is connected with a suction port of a compressor, a throttling element is arranged in a passage between the first oil return port and the suction port; a first air outlet pipe, which is arranged in the cavity, and is provided with a second oil return port, and an air outlet end of the first air outlet pipe is connected with the air outlet; a second air outlet pipe, which is arranged in the cavity, and an air outlet end of the second air outlet pipe is connected with the air outlet; a first valve body for controlling the communication and blockage between the first gas outlet pipe and the gas outlet; a second valve body for controlling the communication and blockage between the first oil return port and the air inlet; the control method comprises: after the air conditioner is started, obtaining an ambient temperature; controlling the first valve body and the second valve body to act based on the ambient temperature; the step of "controlling the first valve body and the second valve body to act based on the ambient temperature" further comprises: when the ambient temperature is greater than a first preset temperature, controlling the first valve body to control the communication between the first gas outlet pipe and the gas outlet, and controlling the second valve body to control the blockage between the first oil return port and the air inlet; and / or when the ambient temperature is less than or equal to the first preset temperature and greater than a second preset temperature, before, at the same time as, or after the compressor is started, and / or when the ambient temperature is less than or equal to the second preset temperature, controlling the second valve body to control the communication between the first oil return port and the air inlet, and controlling the first valve body to control the blockage between the first gas outlet pipe and the gas outlet.

8. The control method of the air conditioner according to claim 7, wherein the step of "controlling the first valve body and the second valve body to act based on the ambient temperature" further comprises: when the ambient temperature is less than or equal to the first preset temperature and greater than the second preset temperature, after the compressor exits the starting stage, controlling the first valve body to control the communication between the first gas outlet pipe and the gas outlet, and controlling the second valve body to control the blockage between the first oil return port and the air inlet.

9. The control method of the air conditioner according to claim 7, wherein the gas-liquid separator further comprises a third valve body for controlling the communication and blockage between the second gas outlet pipe and the gas outlet; the step of "when the ambient temperature is greater than the first preset temperature, controlling the first valve body to control the communication between the first gas outlet pipe and the gas outlet, and controlling the second valve body to control the blockage between the first oil return port and the air inlet" further comprises: when the ambient temperature is greater than the first preset temperature, controlling the first valve body to control the communication between the first gas outlet pipe and the gas outlet, controlling the second valve body to control the blockage between the first oil return port and the air inlet, and controlling the third valve body to control the blockage between the second gas outlet pipe and the gas outlet.

10. The control method of the air conditioner according to claim 7, wherein the gas-liquid separator further comprises a third valve body for controlling the communication and blockage between the second gas outlet pipe and the gas outlet; the step of "when the ambient temperature is less than or equal to the first preset temperature and greater than the second preset temperature, before, at the same time as, or after the compressor is started, and / or when the ambient temperature is less than or equal to the second preset temperature, controlling the second valve body to control the communication between the first oil return port and the air inlet, and controlling the first valve body to control the blockage between the first gas outlet pipe and the gas outlet" further comprises: when the ambient temperature is less than or equal to the first preset temperature and greater than the second preset temperature, before, at the same time or after the compressor is started, and / or when the ambient temperature is less than or equal to the second preset temperature, the first valve body is controlled to control the communication between the first oil return port and the suction port; the first valve body is controlled to control the blockage between the first gas outlet pipe and the gas outlet; the third valve body is controlled to control the communication between the second gas outlet pipe and the gas outlet.

11. The control method of claim 8, wherein, the gas-liquid separator further comprises a third valve body for controlling the communication and blockage between the second gas outlet pipe and the gas outlet; the step of "when the ambient temperature is less than or equal to the first preset temperature and greater than the second preset temperature, after the compressor exits the starting stage, the first valve body is controlled to control the communication between the first gas outlet pipe and the gas outlet, and the second valve body is controlled to control the blockage between the first oil return port and the suction port" further comprises: when the ambient temperature is less than or equal to the first preset temperature and greater than the second preset temperature, after the compressor exits the starting stage, the first valve body is controlled to control the communication between the first gas outlet pipe and the gas outlet, the second valve body is controlled to control the blockage between the first oil return port and the suction port, and the third valve body is controlled to control the blockage between the second gas outlet pipe and the gas outlet.

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