Injection oil return device and system based on screw compression type refrigerating system

Abstract

The utility model provides an ejection oil return device and system based on a screw compression type refrigerating system, and the ejection oil return device based on the screw compression type refrigerating system comprises an ejector, a high-pressure air pipe, an ejection air return pipe, a low-pressure oil pipe, a first electromagnetic valve and a second electromagnetic valve, the utility model further discloses an injection oil return system based on the screw compression type refrigerating system. The injection oil return system comprises the screw compression type refrigerating system and the injection oil return device based on the screw compression type refrigerating system. According to the screw compression type refrigeration system, refrigeration oil in the screw compression type refrigeration system can flow back to the refrigeration compressor unit, and the requirement for normal operation of the refrigeration compressor unit is met.

Description

Technical Field

[0001] This utility model relates to the field of oil return technology for screw compressor refrigeration systems, and in particular to an ejector oil return device and system based on a screw compressor refrigeration system. Background Art

[0002] A screw compressor refrigeration system mainly consists of a refrigeration compressor unit, condenser, receiver, low-pressure circulating tank, working fluid pump, and evaporator. Refrigeration oil is an indispensable component of a screw compressor refrigeration system, playing a crucial lubricating role. High-speed moving parts within the refrigeration compressor unit (such as bearings and shaft seals) require lubrication from the refrigeration oil to reduce friction and wear, thereby extending the service life of the refrigeration compressor unit. In addition, refrigeration oil also plays a role in cooling, sealing, and noise reduction. Without refrigeration oil lubrication, the lifespan of the refrigeration compressor unit may be shortened, and friction and wear between equipment will increase, which is detrimental to the normal operation of the equipment.

[0003] Currently, due to factors such as poor sealing of components in refrigeration compressor units, insufficient superheat of compressor suction, and low compressor discharge temperature, the refrigeration oil is not completely separated in the oil separator. It enters the screw compressor refrigeration system and accumulates in heat exchangers and containers such as condensers, evaporators, and low-pressure circulating tanks. This causes abnormal working pressure in the screw compressor refrigeration system, which in turn causes the refrigeration compressor unit to make noise due to insufficient oil supply, and may even trigger the low oil supply pressure alarm and shutdown protection of the refrigeration compressor unit.

[0004] Therefore, maintaining a reasonable level of refrigerant oil in the oil separator of the refrigeration compressor unit is a necessary condition for ensuring the normal operation of the refrigeration compressor unit. This requires taking certain measures to return the refrigerant oil existing in the screw compressor refrigeration system to the refrigeration compressor unit in order to meet the normal operation requirements of the refrigeration compressor unit. Utility Model Content

[0005] To address the aforementioned technical problems, this invention provides an oil return device and system based on a screw compressor refrigeration system. This invention enables the refrigerant oil present in the screw compressor refrigeration system to flow back into the refrigeration compressor unit, meeting the normal operating requirements of the refrigeration compressor unit. The technical means employed in this invention are as follows:

[0006] In a first aspect, an ejector oil return device based on a screw compressor refrigeration system includes an ejector, a high-pressure gas pipe, an ejector return gas pipe, a low-pressure oil pipe, a first solenoid valve, and a second solenoid valve; the output end of the high-pressure gas pipe is connected to the left input end of the ejector; the input end of the ejector return gas pipe is connected to the right output end of the ejector; the output end of the low-pressure oil pipe is connected to the upper input end of the ejector; the first solenoid valve is installed on the high-pressure gas pipe; and the second solenoid valve is installed on the low-pressure oil pipe.

[0007] Furthermore, it also includes several level oil pipes; the input end of the level oil pipe is located above the output end, and the height difference between the input end and the output end of the level oil pipe is set as the height of the level oil pipe, and the heights of any two level oil pipes are different; the output end of the level oil pipe is connected to the input end of the low-pressure oil pipe.

[0008] Furthermore, it also includes several oil shut-off valves; the number of oil shut-off valves is the same as the number of liquid level oil pipes, and the several oil shut-off valves are installed one-to-one on the several liquid level oil pipes.

[0009] Furthermore, it also includes a first filter and a second filter; the first filter is installed on the high-pressure air pipe at the portion between the input end of the high-pressure air pipe and the first solenoid valve; the second filter is installed on the low-pressure oil pipe at the portion between the input end of the low-pressure oil pipe and the second solenoid valve.

[0010] Furthermore, it also includes a first shut-off valve, a second shut-off valve, a third shut-off valve, and a fourth shut-off valve; the first shut-off valve is installed on the high-pressure air pipe at the portion between the input end of the high-pressure air pipe and the first filter; the second shut-off valve is installed on the high-pressure air pipe at the portion between the output end of the high-pressure air pipe and the first solenoid valve; the third shut-off valve is installed at the input end of the ejector return air pipe; and the fourth shut-off valve is installed at the output end of the ejector return air pipe.

[0011] Secondly, an ejector oil return system based on a screw compressor refrigeration system includes a screw compressor refrigeration system, wherein the screw compressor refrigeration system includes a refrigeration compressor unit and a low-pressure circulation tank, and further includes an ejector oil return device based on the screw compressor refrigeration system as described in any one of the first aspects; the input end of the high-pressure gas pipe in the ejector oil return device is connected to the high-pressure gas outlet end of the refrigeration compressor unit, the output end of the ejector return gas pipe in the ejector oil return device is connected to the low-pressure gas suction end of the refrigeration compressor unit, and the input end of the liquid level oil pipe in the ejector oil return device is installed inside the low-pressure circulation tank.

[0012] This utility model has the following advantages:

[0013] 1. In this utility model, when the low-pressure circulating tank needs to be drained, the second solenoid valve is first opened to keep the low-pressure oil pipe connected, and then the first solenoid valve is opened to allow the high-pressure, high-speed working gas generated at the high-pressure outlet of the refrigeration compressor unit to enter the left input end of the ejector through the high-pressure gas pipe. A suction effect is formed inside the ejector, drawing the mixture of refrigeration oil and working gas from the low-pressure oil pipe into the ejector. After the high-pressure, high-speed working gas and refrigeration oil are mixed inside the ejector, they are discharged from the right output end of the ejector and flow back to the low-pressure suction end of the refrigeration compressor unit through the ejector return gas pipe, so that the refrigeration oil can be recycled and used to meet the normal operation requirements of the refrigeration compressor unit.

[0014] 2. In this utility model, by setting up several oil level pipes with different heights, this utility model can draw refrigeration oil from different working liquid levels in the low-pressure circulation tank.

[0015] 3. In this utility model, the oil shut-off valve can control the connection and disconnection of the liquid level oil pipe.

[0016] 4. In this utility model, the first filter can filter the high-pressure, high-speed working gas in the high-pressure gas pipe, and the second filter can filter the mixture of refrigeration oil and working gas in the low-pressure oil pipe.

[0017] 5. In this utility model, after debugging, the first shut-off valve, the second shut-off valve, the third shut-off valve, and the fourth shut-off valve are all in the open state. When the first filter or the first solenoid valve is being repaired, the first shut-off valve and the second shut-off valve need to be closed at the same time. After the repair is completed, the first shut-off valve and the second shut-off valve are opened. When the second filter or the second solenoid valve is being repaired, the second shut-off valve, the third shut-off valve, and the oil extraction shut-off valve need to be closed at the same time. After the repair is completed, the second shut-off valve, the third shut-off valve, and the oil extraction shut-off valve are opened and kept in standby state. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is an overall structural diagram of an ejector oil return device and system based on a screw compression refrigeration system according to an embodiment of the present utility model;

[0020] Figure reference numerals: 1-Refrigeration compressor unit; 2-High-pressure gas pipe; 3-First shut-off valve; 4-First filter; 5-First solenoid valve; 6-Second shut-off valve; 7-Second filter; 8-Ejector; 9-Second solenoid valve; 10-Third shut-off valve; 11-Ejector return gas pipe; 12-Low-pressure circulation tank; 13-Fourth shut-off valve; 14-Liquid level oil pipe; 15-Oil intake shut-off valve; 16-Low-pressure oil pipe. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0022] Example 1:

[0023] like Figure 1 As shown, an ejector oil return device based on a screw compressor refrigeration system includes an ejector 8, a high-pressure gas pipe 2, an ejector return gas pipe 11, a low-pressure oil pipe 16, a first solenoid valve 5, and a second solenoid valve 9. The output end of the high-pressure gas pipe 2 is connected to the left input end of the ejector 8; the input end of the ejector return gas pipe 11 is connected to the right output end of the ejector 8; the output end of the low-pressure oil pipe 16 is connected to the upper input end of the ejector 8; the first solenoid valve 5 is installed on the high-pressure gas pipe 2; and the second solenoid valve 9 is installed on the low-pressure oil pipe 16.

[0024] In this embodiment, a plurality of level oil pipes 14 are also included; the input end of the level oil pipe 14 is located above the output end, and the height difference between the input end and the output end of the level oil pipe 14 is set as the height of the level oil pipe 14, and the heights of any two level oil pipes 14 are different from each other; the output end of the level oil pipe 14 is connected to the input end of the low-pressure oil pipe 16.

[0025] Specifically, the liquid level oil pipe 14 is provided with three pipes, enabling this embodiment to draw refrigeration oil from three different working liquid levels in the low-pressure circulation tank 12.

[0026] In this embodiment, a plurality of oil shut-off valves 15 are also included; the number of oil shut-off valves 15 is the same as that of the liquid level oil pipes 14, and the plurality of oil shut-off valves 15 are installed on the plurality of liquid level oil pipes 14 in a one-to-one correspondence.

[0027] Specifically, three oil shut-off valves 15 are provided to control the connection and disconnection of the three liquid level oil pipes 14 respectively.

[0028] In this embodiment, a first filter 4 and a second filter 7 are also included. The first filter 4 is installed on the high-pressure gas pipe 2 at the portion between the input end of the high-pressure gas pipe 2 and the first solenoid valve 5, and is used to filter the high-pressure, high-speed working gas in the high-pressure gas pipe 2. The second filter 7 is installed on the low-pressure oil pipe 16 at the portion between the input end of the low-pressure oil pipe 16 and the second solenoid valve 9, and is used to filter the mixture of refrigeration oil and working gas in the low-pressure oil pipe 16.

[0029] In this embodiment, a first shut-off valve 3, a second shut-off valve 6, a third shut-off valve 10, and a fourth shut-off valve 13 are also included. The first shut-off valve 3 is installed on the high-pressure air pipe 2 at the portion between the input end of the high-pressure air pipe 2 and the first filter 4. The second shut-off valve 6 is installed on the high-pressure air pipe 2 at the portion between the output end of the high-pressure air pipe 2 and the first solenoid valve 5. The third shut-off valve 10 is installed at the input end of the ejector return air pipe 11. The fourth shut-off valve 13 is installed at the output end of the ejector return air pipe 11.

[0030] Example 2:

[0031] like Figure 1 As shown, an ejector oil return system based on a screw compressor refrigeration system includes a screw compressor refrigeration system, which includes a refrigeration compressor unit 1 and a low-pressure circulation tank 12, and also includes an ejector oil return device based on the screw compressor refrigeration system as described in any one of Embodiment 1; the input end of the high-pressure gas pipe 2 in the ejector oil return device is connected to the high-pressure gas outlet end of the refrigeration compressor unit 1, the output end of the ejector return gas pipe 11 in the ejector oil return device is connected to the low-pressure gas suction end of the refrigeration compressor unit 1, and the input end of the liquid level oil pipe 14 in the ejector oil return device is installed inside the low-pressure circulation tank 12.

[0032] Specifically, the screw compressor refrigeration system also includes a condenser and an evaporator. The high-pressure outlet of the refrigeration compressor unit 1 is connected to the condenser, the low-pressure circulation tank 12 is connected to the low-pressure suction end of the refrigeration compressor unit 1, and the evaporator is connected to the low-pressure circulation tank 12 through pipes. A shut-off valve is installed on the pipes.

[0033] The working principle of this embodiment:

[0034] After debugging, the first shut-off valve 3, the second shut-off valve 6, the third shut-off valve 10, and the fourth shut-off valve 13 are all in the open state.

[0035] When the low-pressure circulating tank 12 needs to be drained, first open the oil intake shut-off valve 15 and the second solenoid valve 9 to keep the liquid level oil pipe 14 and the low-pressure oil pipe 16 connected. Then open the first solenoid valve 5 to allow the high-pressure, high-speed working gas generated at the high-pressure outlet of the refrigeration compressor unit 1 to enter the left input end of the ejector 8 through the high-pressure gas pipe 2, the first shut-off valve 3, the first filter 4, the first solenoid valve 5, and the second shut-off valve 6. A suction effect is formed inside the ejector 8, drawing the mixture of refrigeration oil and working gas from the liquid level oil pipe 14 and the low-pressure oil pipe 16 into the ejector 8. After the high-pressure, high-speed working gas and refrigeration oil are mixed inside the ejector 8, they are discharged from the right output end of the ejector 8 and flow back to the low-pressure suction end of the refrigeration compressor unit 1 through the third shut-off valve 10, the ejector return gas pipe 11, and the fourth shut-off valve 13, so that the refrigeration oil can be recycled to meet the normal operation requirements of the refrigeration compressor unit 1.

[0036] When the first filter 4 or the first solenoid valve 5 is being repaired, the first shut-off valve 3 and the second shut-off valve 6 must be closed simultaneously. After the repair is completed, the first shut-off valve 3 and the second shut-off valve 6 should be opened. When the second filter 7 or the second solenoid valve 9 is being repaired, the second shut-off valve 6, the third shut-off valve 10 and the oil cut-off valve 15 must be closed simultaneously. After the repair is completed, the second shut-off valve 6, the third shut-off valve 10 and the oil cut-off valve 15 should be opened and kept in standby mode.

[0037] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this utility model.

Claims

1. An ejector oil return device based on a screw compressor refrigeration system, characterized in that, Includes an ejector (8), a high-pressure gas pipe (2), an ejector return gas pipe (11), a low-pressure oil pipe (16), a first solenoid valve (5), and a second solenoid valve (9); The output end of the high-pressure air pipe (2) is connected to the left input end of the ejector (8); The input end of the ejector return pipe (11) is connected to the right output end of the ejector (8); The output end of the low-pressure oil pipe (16) is connected to the upper input end of the ejector (8); The first solenoid valve (5) is installed on the high-pressure air pipe (2); The second solenoid valve (9) is installed on the low-pressure oil pipe (16).

2. The oil return device based on a screw compressor refrigeration system according to claim 1, characterized in that, It also includes several level oil pipes (14); The input end of the liquid level oil pipe (14) is located above the output end. The height difference between the input end and the output end of the liquid level oil pipe (14) is set as the height of the liquid level oil pipe (14). The heights of any two liquid level oil pipes (14) are different. The output end of the level oil pipe (14) is connected to the input end of the low-pressure oil pipe (16).

3. The oil return device based on a screw compressor refrigeration system according to claim 2, characterized in that, It also includes several oil shut-off valves (15); The number of oil shut-off valves (15) is the same as the number of liquid level oil pipes (14), and the plurality of oil shut-off valves (15) are installed on the plurality of liquid level oil pipes (14) in a corresponding manner.

4. The oil return device based on a screw compressor refrigeration system according to claim 1, characterized in that, It also includes a first filter (4) and a second filter (7); The first filter (4) is installed on the high-pressure air pipe (2) on the part between the input end of the high-pressure air pipe (2) and the first solenoid valve (5); The second filter (7) is installed on the part of the low-pressure oil pipe (16) between the inlet end of the low-pressure oil pipe (16) and the second solenoid valve (9).

5. The oil return device based on a screw compressor refrigeration system according to claim 4, characterized in that, It also includes a first shut-off valve (3), a second shut-off valve (6), a third shut-off valve (10), and a fourth shut-off valve (13); The first shut-off valve (3) is installed on the high-pressure air pipe (2) on the part between the inlet end of the high-pressure air pipe (2) and the first filter (4); The second shut-off valve (6) is installed on the high-pressure air pipe (2) on the part between the output end of the high-pressure air pipe (2) and the first solenoid valve (5); The third shut-off valve (10) is installed at the inlet end of the ejector return pipe (11); The fourth shut-off valve (13) is installed at the output end of the ejector return pipe (11).

6. An ejector oil return system based on a screw compressor refrigeration system, comprising a screw compressor refrigeration system, wherein the screw compressor refrigeration system includes a refrigeration compressor unit (1) and a low-pressure circulation tank (12), characterized in that, It also includes the ejector oil return device based on the screw compression refrigeration system as described in any one of claims 1 to 5; The input end of the high-pressure gas pipe (2) in the ejector oil return device based on the screw compression refrigeration system is connected to the high-pressure gas outlet of the refrigeration compressor unit (1), the output end of the ejector gas return pipe (11) in the ejector oil return device based on the screw compression refrigeration system is connected to the low-pressure gas suction end of the refrigeration compressor unit (1), and the input end of the liquid level oil pipe (14) in the ejector oil return device based on the screw compression refrigeration system is installed in the low-pressure circulation tank (12).

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