Multifunctional gas-liquid separator, Multi-connected air conditioner and control method thereof

Abstract

The application discloses a multifunctional gas-liquid separator, a multi-connected air conditioner and a control method thereof, which comprises a gas-liquid separator main body, an inlet pipe, an outlet pipe, an electronic expansion valve EEVA, a liquid equalizing pipe, a liquid return hole filter screen, a first connecting pipe and a second connecting pipe. The inlet pipe and the outlet pipe are fixed to the top of the gas-liquid separator main body. One end of the first connecting pipe is connected to the outlet pipe, and the other end is connected to the electronic expansion valve EEVA. One end of the second connecting pipe is connected to the electronic expansion valve EEVA, and the other end is connected to the liquid return hole at the bottom of the gas-liquid separator main body. The liquid return hole filter screen is fixed to the liquid return hole. The liquid equalizing pipe is connected to the bottom of the gas-liquid separator main body. The inlet pipe is connected to a four-way valve of the multi-connected air conditioner. The outlet pipe is connected to a suction port of a compressor. The liquid equalizing pipes of the main machine and the sub-machine of the outdoor unit are both connected to a solenoid valve SV10 and are in communication. The control of the solenoid valve SV10 and the electronic expansion valve EEVA can fully adjust the refrigerant amount in the circulating system and improve the refrigeration and heating effects.

Description

Technical Field

[0001] This invention belongs to the field of multi-split air conditioning technology, specifically relating to a multi-functional gas-liquid separator, a multi-split air conditioner, and its control method. Background Technology

[0002] Air conditioners require less refrigerant in heating mode than in cooling mode. If the system is charged with the same amount of refrigerant as in cooling mode, more refrigerant will be needed in heating mode, causing a large amount to accumulate in the indoor unit and affecting heating performance. In ultra-low temperature cooling conditions, due to the low outdoor ambient temperature, even if the outdoor fan is not running, the condenser temperature is also low, causing most of the refrigerant to accumulate on the outdoor side, resulting in insufficient refrigerant supply to the indoor unit and poor indoor cooling performance. Summary of the Invention

[0003] The purpose of this invention is to provide a multifunctional gas-liquid separator, a multi-split air conditioner, and a control method thereof, in order to solve the problem that existing multi-split air conditioner gas-liquid separators with mechanical oil return holes or capillary tubes cannot accurately control the liquid return situation and cannot quickly adjust the refrigerant in the gas separator into the refrigerant system.

[0004] To achieve the above objectives, the present invention provides the following technical solution: This invention provides a multifunctional gas-liquid separator, comprising a gas-liquid separator body, an inlet pipe, and an outlet pipe. The inlet pipe and outlet pipe are fixed to the top of the gas-liquid separator body. The separator also includes an electronic expansion valve (EEVA), a liquid equalization pipe, a return liquid hole filter, a first connecting pipe, and a second connecting pipe. One end of the first connecting pipe is connected to the outlet pipe, and the other end is connected to the electronic expansion valve (EEVA). One end of the second connecting pipe is connected to the electronic expansion valve (EEVA), and the other end is connected to a return liquid hole at the bottom of the gas-liquid separator body. A return liquid hole filter is fixed to the return liquid hole. The liquid equalization pipe is connected to the bottom of the gas-liquid separator body.

[0005] Preferably, the main body of the gas-liquid separator is a container with a volume V1, where V1≤30L, formed by welding an upper end cover, a lower end cover, and a cylinder.

[0006] Preferably, the inlet pipe is a copper pipe with a diameter of 19.05-25.58 mm and a wall thickness of 1.0-1.4 mm, which is welded to the upper end cap.

[0007] Preferably, the outlet pipe is a copper pipe with a diameter of 15.88-22.22 mm and a wall thickness of 0.8-1.2 mm, which is welded to the upper end cap.

[0008] Preferably, the valve orifice diameter of the electronic expansion valve EEVA is 1.5-3.2 mm.

[0009] Preferably, the first connecting pipe, the second connecting pipe, and the liquid equalization pipe are all copper pipes with a diameter of 6.35-9.52 mm and a wall thickness of 0.6-1.0 mm.

[0010] The present invention also provides a multi-split air conditioner using the aforementioned multi-functional gas-liquid separator. The inlet pipe of the multi-functional gas-liquid separator is connected to the four-way valve of the multi-split air conditioner, and the outlet pipe is connected to the compressor suction port of the multi-split air conditioner. Furthermore, the liquid equalization pipes of the multi-functional gas-liquid separators of the outdoor unit and the sub-unit of the multi-split air conditioner are both connected to and connected to the solenoid valve SV10.

[0011] This invention provides a control method for the aforementioned multi-split air conditioner. When any of the following conditions are met: a first heating mode, 10 minutes after heating starts, and the outdoor unit's electronic expansion valve (EEVH) step count reaching 470 steps and remaining so for 1 minute, the solenoid valves SV10 of all outdoor unit main units and sub-units are opened, closed after 120 seconds, and the outdoor unit's electronic expansion valve (EEVA) is opened to step 40. Afterwards, the electronic expansion valve (EEVA) is controlled by PI control according to the exhaust temperature TD - high-pressure saturation temperature DSST = 20℃. The electronic expansion valve EEVA will be closed when any of the following conditions are met: First, the opening degree of the electronic expansion valve EEVH of all outdoor units is ≤300 steps; second, the compressor is shut down; and third, defrosting or oil return control is started.

[0012] This invention also provides a control method for the aforementioned multi-split air conditioner. When any of the following conditions are met: a first cooling mode, 10 minutes after cooling start-up, and a third condition where the indoor unit's electronic expansion valve (EEV) reaches 470 steps and remains so for 1 minute, the solenoid valves SV10 of all outdoor unit main units and sub-units are opened, closed after 120 seconds, and the outdoor unit's electronic expansion valve (EEVA) is opened to step 40. Afterward, the electronic expansion valve (EEVA) is controlled by PI control according to the exhaust temperature TD - high-pressure saturation temperature DSST = 20℃. The electronic expansion valve EEVA will be closed if any of the following conditions are met: First, the opening degree of the electronic expansion valve EEV of all indoor units is ≤300 steps; Second, the compressor is off.

[0013] Compared with the prior art, the beneficial effects of the present invention are as follows: The gas-liquid separator of the present invention not only separates gas and liquid refrigerant, preventing compressor liquid return and improving compressor reliability, but also regulates the amount of refrigerant in heating conditions, especially for refrigerant systems without a liquid receiver circuit and in ultra-low temperature refrigeration conditions, enabling the air conditioning system to achieve optimal cooling and heating effects; through this gas-liquid separator structure, combined with the control of solenoid valve SV10 and electronic expansion valve EEVA, the amount of refrigerant in the circulation system can be fully regulated, ensuring stable system operation and improving cooling and heating effects. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the gas-liquid separator according to an embodiment of the present invention.

[0015] Figure 2 This is a schematic diagram of a multi-split air conditioning system according to an embodiment of the present invention.

[0016] The image is labeled as follows: Gas-liquid separator body 1, inlet pipe 2, outlet pipe 3, liquid equalization pipe 4, return liquid hole filter screen 5, first connecting pipe 6, second connecting pipe 7, four-way valve 8, compressor 9, upper end cover 101, lower end cover 102, cylinder 103, return liquid hole 104. Detailed Implementation

[0017] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below through examples.

[0018] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0019] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in different places in this specification does not necessarily refer to the same embodiment, nor is it a single or selective embodiment that is mutually exclusive with other embodiments. Example:

[0020] Reference Figure 1 A multifunctional gas-liquid separator includes a gas-liquid separator body 1, an inlet pipe 2, and an outlet pipe 3. The inlet pipe 2 and the outlet pipe 3 are fixed to the top of the gas-liquid separator body 1. Specifically, the gas-liquid separator body 1 is a container with a volume V1, where V1 ≤ 30L, formed by welding an upper end cover 101, a lower end cover 102, and a cylinder 103. In this embodiment, the inlet pipe 2 and the outlet pipe 3 are fixed to the upper end cover 101 of the gas-liquid separator body 1. The multifunctional gas-liquid separator also includes an electronic expansion valve EEVA, a liquid equalization pipe 4, a return liquid hole filter screen 5, a first connecting pipe 6, and a second connecting pipe 7. One end of the first connecting pipe 6 is connected to the outlet pipe 3, and the other end is connected to the electronic expansion valve EEVA. One end of the second connecting pipe 6 is connected to the electronic expansion valve EEVA, and the other end is connected to the return liquid hole 104 at the bottom of the gas-liquid separator body 1. The return liquid hole filter screen 5 is fixed on the return liquid hole 104. The liquid equalization pipe 4 is connected to the bottom of the gas-liquid separator body 1.

[0021] In a preferred embodiment of this invention, the inlet pipe 2 is a copper pipe with a diameter of 19.05-25.58 mm and a wall thickness of 1.0-1.4 mm, which is welded to the upper end cap 101.

[0022] In a preferred embodiment of this invention, the outlet pipe 3 is a copper pipe with a diameter of 15.88-22.22 mm and a wall thickness of 0.8-1.2 mm, which is welded to the upper end cap 101.

[0023] In a preferred embodiment of this example, the valve orifice diameter of the electronic expansion valve EEVA is 1.5-3.2 mm.

[0024] In a preferred embodiment of this invention, the first connecting pipe 6, the second connecting pipe 7, and the liquid equalization pipe 4 are all copper pipes with a diameter of 6.35-9.52 mm and a wall thickness of 0.6-1.0 mm.

[0025] like Figure 2 As shown, the multi-split air conditioner in this embodiment uses the above-mentioned multi-functional gas-liquid separator. Except for the gas-liquid separator, the other components and connection methods of the multi-split air conditioner are all existing technologies. The connection method of the multi-functional gas-liquid separator is as follows: the inlet pipe 2 of the multi-functional gas-liquid separator is connected to the four-way valve 8 of the multi-split air conditioner, and the outlet pipe 3 is connected to the suction port of the compressor 9 of the multi-split air conditioner. The liquid equalization pipes 4 of the multi-functional gas-liquid separator of the outdoor unit and the sub-unit of the multi-split air conditioner are both connected to the solenoid valve SV10 and are interconnected.

[0026] In this embodiment, the control method for a multi-split air conditioner involves the following steps during heating: when the following conditions are met: first heating mode, 10 minutes after second heating start-up, and third, the electronic expansion valve EEVH step count of the outdoor unit reaches 470 steps and remains so for 1 minute, all outdoor unit main units and sub-units' solenoid valves SV10 are opened and closed for 120 seconds. This draws the refrigerant from the gas-liquid separator of the stopped outdoor unit into the gas-liquid separator of the running outdoor unit. Then, the electronic expansion valve EEVA of the outdoor unit is opened to step 40. Subsequently, the electronic expansion valve EEVA is controlled by PI according to the exhaust temperature TD - high-pressure saturation temperature DSST = 20°C, so that the refrigerant in the operating system is kept in an optimal state for heating, thereby ensuring the heating effect.

[0027] The electronic expansion valve EEVA will be closed when any of the following conditions are met: First, the opening degree of the electronic expansion valve EEVH of all outdoor units is ≤300 steps; second, the compressor is shut down; and third, defrosting or oil return control is started.

[0028] In this embodiment, the control method for a multi-split air conditioner involves the following steps during cooling: when the following conditions are met: first cooling mode, 10 minutes after cooling starts, or the indoor unit's electronic expansion valve (EEV) step count is 470 steps and lasts for 1 minute, all outdoor unit main and sub-unit solenoid valves SV10 are opened and closed for 120 seconds. This draws the refrigerant from the gas-liquid separator of the stopped outdoor unit into the gas-liquid separator of the running outdoor unit. Then, the outdoor unit's electronic expansion valve (EEVA) is opened to step 40. Subsequently, the electronic expansion valve (EEVA) is controlled by PI according to the exhaust temperature TD - high-pressure saturation temperature DSST = 20°C, so that the refrigerant in the operating system is kept in an optimal state for corresponding cooling, thereby ensuring the cooling effect.

[0029] The electronic expansion valve EEVA will be closed if any of the following conditions are met: First, the opening degree of the electronic expansion valve EEV of all indoor units is ≤300 steps; Second, the compressor is off.

[0030] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A multifunctional gas-liquid separator, comprising a gas-liquid separator body, an inlet pipe, and an outlet pipe, wherein the inlet pipe and the outlet pipe are fixed to the top of the gas-liquid separator body, characterized in that, It also includes an electronic expansion valve (EEVA), a liquid equalization pipe, a return liquid hole filter screen, a first connecting pipe, and a second connecting pipe. One end of the first connecting pipe is connected to the outlet pipe, and the other end is connected to the electronic expansion valve (EEVA). One end of the second connecting pipe is connected to the electronic expansion valve (EEVA), and the other end is connected to the return liquid hole at the bottom of the gas-liquid separator body. A return liquid hole filter screen is fixed on the return liquid hole. The liquid equalization pipe is connected to the bottom of the gas-liquid separator body.

2. The multifunctional gas-liquid separator according to claim 1, characterized in that: The main body of the gas-liquid separator is a container with a volume V1, where V1≤30L, formed by welding an upper end cover, a lower end cover, and a cylinder.

3. The multifunctional gas-liquid separator according to claim 2, characterized in that: The inlet pipe is a copper pipe with a diameter of 19.05-25.58 mm and a wall thickness of 1.0-1.4 mm, which is welded to the upper end cap.

4. The multifunctional gas-liquid separator according to claim 2, characterized in that: The outlet pipe is a copper pipe with a diameter of 15.88-22.22 mm and a wall thickness of 0.8-1.2 mm, which is welded to the upper end cap.

5. The multifunctional gas-liquid separator according to claim 1, characterized in that: The valve orifice diameter of the electronic expansion valve EEVA is 1.5-3.2mm.

6. The multifunctional gas-liquid separator according to claim 1, characterized in that: The first connecting pipe, the second connecting pipe, and the liquid equalization pipe are all copper pipes with a diameter of 6.35-9.52 mm and a wall thickness of 0.6-1.0 mm.

7. A multi-split air conditioner employing the multifunctional gas-liquid separator as described in any one of claims 1-6, characterized in that: The inlet pipe of the multi-functional gas-liquid separator is connected to the four-way valve of the multi-split air conditioner, and the outlet pipe is connected to the air intake of the compressor of the multi-split air conditioner. The liquid equalization pipes of the multi-functional gas-liquid separators of the outdoor unit and the sub-unit of the multi-split air conditioner are both connected to the solenoid valve SV10 and are in communication.

8. A control method for a multi-split air conditioner employing a multi-functional gas-liquid separator, characterized in that: When any of the following conditions are met: first heating mode, second heating start-up 10 minutes later, and third outdoor unit electronic expansion valve EEVH step count reaches 470 steps and remains so for 1 minute, all outdoor unit main and sub-unit solenoid valves SV10 are opened, closed after 120 seconds, and the outdoor unit electronic expansion valve EEVA is opened to step 40. Afterwards, the electronic expansion valve EEVA is controlled by PI based on exhaust temperature TD - high-pressure saturation temperature DSST = 20℃. The electronic expansion valve EEVA will be closed when any of the following conditions are met: First, the opening degree of the electronic expansion valve EEVH of all outdoor units is ≤300 steps; second, the compressor is shut down; and third, defrosting or oil return control is started.

9. A control method for a multi-split air conditioner employing a multi-functional gas-liquid separator, characterized in that: When any of the following conditions are met: first cooling mode, second cooling start-up 10 minutes later, and third indoor unit electronic expansion valve EEV step count of 470 steps for 1 minute, all outdoor unit main unit and sub-unit solenoid valves SV10 are opened, closed after 120 seconds, and the outdoor unit electronic expansion valve EEVA is opened to step 40. Afterwards, the electronic expansion valve EEVA is controlled by PI based on exhaust temperature TD - high-pressure saturation temperature DSST = 20℃. The electronic expansion valve EEVA will be closed if any of the following conditions are met: First, the opening degree of the electronic expansion valve EEV of all indoor units is ≤300 steps; Second, the compressor is off.

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