Oil-gas separator and cooling system having the same

Abstract

This invention relates to an oil-gas separator and a refrigeration system having the oil-gas separator. The oil-gas separator includes an outer shell, an inner cylinder, an intake pipe, an exhaust pipe, and an oil drain pipe. The outer shell includes an outer cylinder. The inner cylinder is located inside the outer cylinder, and an outer lumen is formed between the outer cylinder and the inner cylinder, with an inner lumen formed inside the inner cylinder. The inner cylinder includes a solid cylinder wall and a pore cylinder wall, the pore cylinder wall is provided with a plurality of pores that connect the outer lumen and the inner lumen, and the solid cylinder wall and the pore cylinder wall are arranged along the circumferential direction of the inner cylinder. The intake pipe is connected to the outer cylinder. The exhaust pipe is connected to the upper part of the outer shell. The oil drain pipe is connected to the bottom of the outer shell. Because the solid cylinder wall and the pore cylinder wall are arranged along the circumferential direction of the inner cylinder, when oil-gas entering the outer lumen undergoes helical motion, it first passes through the solid cylinder wall and then through the pore cylinder wall. This results in a good lubricating oil separation effect and a small pressure drop.

Description

Technical Field

[0001] This application relates to the field of cooling technology, and particularly to an oil-gas separator and a cooling system having the same.

Background Art

[0002] A vapor-compression cooling system includes four major components: a compressor, a condenser, a throttling device, and an evaporator. According to the lubrication method, the compressor can be divided into an oil-free compressor and a lubricating oil compressor. In a lubricating oil compressor, the lubricating oil not only reduces mechanical friction and wear but also plays roles in sealing, cooling, and reducing operating noise. Good lubrication conditions are an important guarantee for the long-term reliable operation of the compressor.

[0003] However, during the operation of the compressor, the lubricating oil is discharged from the compressor together with the refrigerant. If timely oil return cannot be achieved, on the one hand, it will cause failures such as insufficient oil in the compressor, shaft seizure, or burnout. On the other hand, when the lubricating oil enters the heat exchanger together with the refrigerant, it will affect the heat exchange efficiency.

[0004] To solve the above technical problems, it is necessary to provide an oil-gas separator and a cooling system having the same.

Summary of the Invention

[0005] To solve one of the above technical problems, the present invention adopts the following technical solutions.

[0006] One is an oil-gas separator, which includes an outer shell, an inner cylinder, an intake pipe, an exhaust pipe, and an oil drain pipe. The outer shell includes an outer cylinder. The inner cylinder is located inside the outer cylinder, and an outer cavity is formed between the outer cylinder and the inner cylinder, and an inner cavity is formed inside the inner cylinder. The inner cylinder includes a solid cylinder wall and a filter hole cylinder wall. The filter hole cylinder wall has a plurality of filter holes that communicate the outer cavity and the inner cavity, and the solid cylinder wall and the filter hole cylinder wall are arranged along the circumferential direction of the inner cylinder. The intake pipe is connected to the outer cylinder. The exhaust pipe is connected to the upper part of the outer shell. The oil drain pipe is connected to the bottom of the outer shell.

[0007] Another is a cooling system comprising a sequentially connected compressor, condenser, throttle, and evaporator, the cooling system further comprising one of the above-mentioned oil-gas separators, the oil-gas separator being located between the compressor and the condenser, with an intake pipe communicating with the outlet of the compressor, an exhaust pipe communicating with the inlet of the condenser, and an oil drain pipe communicating with the inlet of the compressor.

[0008] Another is a cooling system comprising a sequentially connected first compressor, second compressor, condenser, throttle, and evaporator, the cooling system further comprising any two of the oil-gas separators, one of which is located between the first and second compressors, with an intake pipe communicating with the outlet of the first compressor, an exhaust pipe communicating with the inlet of the second compressor, and an oil drain pipe communicating with the inlet of the first compressor. The other oil-gas separator is located between the second compressor and the condenser, with an intake pipe communicating with the outlet of the second compressor, an exhaust pipe communicating with the inlet of the condenser, and an oil drain pipe communicating with the inlet of the second compressor.

[0009] Compared to conventional technology, the beneficial effects of the present invention are as follows: In the oil-gas separator of the present invention, since the solid cylinder wall and the filter hole cylinder wall are arranged along the circumferential direction of the inner cylinder, when the oil-gas entering the outer lumen undergoes helical motion, it first passes through the solid cylinder wall and then through the filter hole cylinder wall, resulting in a good separation effect of lubricating oil and a small pressure drop. [Brief explanation of the drawing]

[0010] [Figure 1] Figure 1 is a schematic diagram of the structure of an oil-gas separator according to a preferred embodiment of the present invention. [Figure 2] Figure 2 is an exploded view of Figure 1. [Figure 3] Figure 3 is a schematic diagram of Figure 1 from a different angle. [Figure 4] Figure 4 is a cross-sectional view along the direction AA in Figure 3. [Figure 5] Figure 5 is a cross-sectional view along the BB direction in Figure 3. [Figure 6]Figure 6 is a schematic diagram of the structure of the inspiratory tube in Figure 1. [Figure 7] Figure 7 is a schematic diagram of the inner cylinder structure in Figure 1. [Figure 8] Figure 8 is a schematic diagram of the combination of the intake pipe, outer cylinder, and inner cylinder as shown in Figure 1. [Figure 9] Figure 9 is a schematic diagram of the combination of the intake pipe, outer cylinder, and inner cylinder in another embodiment. [Figure 10] Figure 10 is a schematic diagram of the combination of the intake pipe, outer cylinder, and inner cylinder in another embodiment. [Figure 11] Figure 11 is a schematic diagram of the combination of the intake pipe, outer cylinder, and inner cylinder in another embodiment. [Figure 12] Figure 12 is a schematic diagram of the inner cylinder in Figure 1 after it has been cut open in the axial direction. [Figure 13] Figure 13 is a schematic diagram of the inner cylinder after it has been cut in the axial direction in another embodiment. [Figure 14] Figure 14 is a schematic diagram of the inner cylinder after it has been cut in the axial direction in another embodiment. [Figure 15] Figure 15 is a schematic diagram of another embodiment after the inner cylinder has been cut in the axial direction. [Figure 16] Figure 16 is a schematic diagram of the inner cylinder after it has been cut in the axial direction in another embodiment. [Figure 17] Figure 17 is a schematic diagram of the inner cylinder after it has been cut in the axial direction in another embodiment. [Figure 18] Figure 18 is a schematic diagram of another embodiment after the inner cylinder has been cut in the axial direction. [Figure 19] Figure 19 is a schematic diagram of the inner cylinder after it has been cut in the axial direction in another embodiment.

[0011] In Figures 12 to 17, IN indicates the position corresponding to the connection between the intake pipe and the outer pipe on the inner pipe, and the arrow indicates the direction of intake air flow. [Modes for carrying out the invention]

[0012] The embodiments described below with reference to the drawings are exemplary and are for the purpose of explaining the present invention, and should not be construed as limiting the present invention.

[0013] It should be understood that unless there are specific regulations and limitations in the description of the present invention, the orientation or positional relationship indicated by terms such as "inside" and "outside" is based on the orientation or positional relationship shown in the drawings, and is for the purpose of explaining and simplifying the description of the present invention, and does not imply that the device or element must have a specific orientation, be configured and operated in a specific orientation, and therefore should not be understood as a limitation of the present invention. Furthermore, unless there are specific regulations and limitations, the term "connection" should be understood in a broad sense. For example, the connection can be a direct connection or an indirect connection through an intermediate medium, and can be a fixed connection, a movable connection, a detachable connection, or an integral connection. Those skilled in the art can understand the specific meaning of these terms in the present invention according to the specific situation.

[0014] The inventors' research has discovered the following. Conventional oil-gas separators have a poor separation effect on lubricating oil, do not consider pressure drop (pressure loss), affect the cooling efficiency, and are not suitable for large-displacement compressors. As shown in FIG. 1, the oil-gas separator 100 of a preferred embodiment of the present invention aims to separate lubricating oil from the high-temperature and high-pressure refrigerant gas discharged from the compressor and maintain a smaller pressure drop.

[0015] The oil-gas separator 100 includes an outer shell 1, an inner cylinder 2 located inside the outer shell 1, an intake pipe 3 connected to the side of the outer shell 1, an exhaust pipe 4 connected to the upper part of the outer shell 1, and an oil drain pipe 5 connected to the bottom of the outer shell 1. The mixed oil-gas of refrigerant and lubricating oil (hereinafter abbreviated as "oil-gas") discharged from the compressor enters through the intake pipe 3. After the refrigerant and lubricating oil are separated inside, the refrigerant gas is discharged from the exhaust pipe 4, and the separated lubricating oil is discharged from the oil drain pipe 5 and returns to the compressor.

[0016] Specifically, the outer shell 1 includes an outer cylinder 11 extending along the vertical direction, an upper cap 12 connected to the upper part of the outer cylinder 11, and a lower cap 13 connected to the bottom of the outer cylinder 11. The outer cylinder 11 is cylindrical, the inner wall of the outer cylinder 11 is smooth, its cross-section is circular, and the resistance to the flow of oil and gas is small. One of the upper cap 12 and the lower cap 13 is provided integrally with the outer cylinder 11, and the other is integrally connected after being separately provided, or both are integrally connected after being separately provided from the outer cylinder 11.

[0017] The inner cylinder 2 is located inside the outer cylinder 11 and is arranged coaxially with the outer cylinder 11. An outer cavity 10 is formed between the inner cylinder 2 and the outer cylinder 11, an inner cavity 20 is formed inside the inner cylinder 2, and the inner cylinder 2 is provided with filter holes 23 for communicating the outer cavity 10 and the inner cavity 20.

[0018] The intake pipe 3 is connected to the outer cylinder 11 and communicates with the outer cavity 10. The exhaust pipe 4 is connected to the upper cap 12 and communicates with the inner cavity 20. The drain pipe 5 is connected to the lower cap 13 and communicates with both the outer cavity 10 and the inner cavity 20. After the oil and gas enters the outer cavity 10 from the intake pipe 3, most of the lubricating oil is separated by centrifugal action, and a small amount of lubricating oil enters the inner cavity 2 through the filter holes 23 together with the refrigerant and is separated in the inner cavity 2. Finally, the refrigerant is discharged from the exhaust pipe 4, and the separated lubricating oil gathers at the bottom and is discharged through the drain pipe 5.

[0019] The above is the basic structure and connection method of the oil and gas separator 100. The present invention mainly improves the oil and gas separation effect by improving the inner cylinder 2, and at the same time maintains a smaller pressure drop. In addition, the connection methods of other structures are also improved to synergistically enhance the oil and gas separation effect. The following will be described sequentially.

[0020] The connection methods between the inner cylinder 2 and the outer shell 1 include, but are not limited to, the following.

[0021] Method 1: Connection between the upper part of the inner cylinder 2 and the upper cap 12 or the upper part of the outer cylinder 11.

[0022] In this embodiment, the upper cap 12 includes an upper wall 121, an upper outer wall 122 extending downward from the periphery of the upper wall 121, and an upper inner wall 123 extending downward from the central region of the upper wall 121. The upper part of the outer cylinder 11 is connected to the upper outer wall 122, and the upper part of the inner cylinder 2 is connected to the upper inner wall 123. Therefore, in the upper region, the upper inner wall 123 divides the inner lumen 20 and the outer lumen 10 into two independent voids, and the inner lumen 20 and the outer lumen 10 are not in communication.

[0023] In other embodiments, the upper end of the inner cylinder 2 can also be connected to the upper part of the outer cylinder 11 via an upper connecting plate. The structural shape of the upper connecting plate is not limited, as long as it can connect the two. For example, the upper connecting plate includes a first upper wall for connecting to the outer cylinder 11, a second upper wall for connecting to the inner cylinder 2, and an upper connecting wall connecting the first upper wall and the second upper wall. Overall, the upper connecting plate is shaped like an "I", or a "]", or a "Z", or an "S", etc.

[0024] Method 2: A method of connecting the bottom of the inner cylinder 2 to the lower cap 13 or the bottom of the outer cylinder 11, wherein the connection method can be based on the connection method between the upper part of the inner cylinder 2 and the upper cap 12 or the upper part of the outer cylinder 11.

[0025] In one embodiment, the bottom of the inner cylinder 2 is connected to the lower cap 13, which includes a bottom wall, a lower outer wall extending upward from the periphery of the bottom wall, and a lower inner wall extending upward from the central region of the bottom wall. The bottom of the outer cylinder 11 is connected to the lower outer wall, and the bottom of the inner cylinder 2 is connected to the lower inner wall. In addition, to collect the lubricating oil from both the outer lumen 10 and the inner lumen 20 at the bottom, the bottom of the inner cylinder 2 is further provided with a plurality of oil passage holes. Preferably, the plurality of oil passage holes are uniformly arranged in the circumferential direction of the inner cylinder 2. As those skilled in the art will understand, both the oil passage holes and the filter holes 23 connect the outer lumen 10 and the inner lumen 20, and they may be the same or different through holes.

[0026] In another embodiment, the bottom of the inner cylinder 2 can also be connected to the bottom of the outer cylinder 11 via a lower connecting plate 7. The lower connecting plate 7 includes a first vertical wall for connecting to the outer cylinder 11, a second vertical wall for connecting to the inner cylinder 2, and a lower connecting wall connecting the first and second vertical walls. Overall, the configuration of the lower connecting plate 7 and the upper connecting plate are the same and will not be described again here. The lower connecting wall is also provided with oil droplet holes 71 that penetrate in the vertical direction, and the lubricating oil in the outer lumen 10 drips to the bottom through the oil droplet holes 71. Preferably, the oil droplet holes 71 are uniformly distributed on the lower connecting wall.

[0027] Furthermore, the inner cylinder 2 can be connected to the outer shell 1 only via its upper part, only via its bottom, or via both its upper and bottom parts. Moreover, when the inner cylinder 2 is connected to the outer shell 1 via its upper part, the lower connecting plate 7 can be connected to only one of the outer cylinder 11 or the inner cylinder 2. In other words, the first vertical wall or the second vertical wall can be omitted, and the lower connecting plate 7 blocks direct communication between the inner lumen 20 and the outer lumen 10.

[0028] The connection position and method between the intake pipe 3 and the outer cylinder 11 affect the flow direction and flow path of the oil gas within the outer lumen 10.

[0029] On the one hand, considering that the separated lubricating oil drips downward and collects at the bottom of the outer cylinder 11, the intake pipe 3 is connected to the upper half of the outer cylinder 11. That is, the distance L1 from the intake pipe 3 to the upper end of the outer cylinder 11 is less than or equal to half the height of the outer cylinder 11. By leaving a sufficient buffer space below the intake pipe 3, even if the speed at which the high-temperature, high-pressure oil gas enters the outer cylinder 11 is relatively high and the impact force is also large, the buffer space below can prevent the oil gas from colliding with the lubricating oil collected at the bottom and bringing it back into the lumen 20.

[0030] Preferably, L1 is between 1 / 4 and 1 / 2, preferably 1 / 3, of the height of the outer cylinder 11. There is also a certain buffer space above the intake pipe 3, so that the oil gas does not directly collide with the upper cap 12, and the pressure drop is small.

[0031] On the other hand, as those skilled in the art will understand, the direction of extension of the intake pipe has an inductive effect on the oil gas, and therefore the intake direction of the intake pipe 3 generally coincides with the direction of extension of the intake pipe. For this reason, the present invention changes the connection method between the intake pipe 3 and the outer cylinder 11 by adjusting the structure, mounting angle, etc., of the intake pipe 3, thereby adjusting the flow direction when the oil gas enters the outer cylinder 11.

[0032] In the present invention, all intake pipes 3 extend horizontally and are perpendicular to the extension direction of the outer cylinder 11. The connection point between the intake pipe 3 and the outer cylinder 11 is used as the base point, and a tangent line to the outer cylinder 11 passing through this base point is drawn, which is the first cross-section, and the angle ∠C between the intake pipe 3 and the first cross-section is between [0° and 90°]. The direction of intake air flow differs depending on the magnitude of the angle ∠C.

[0033] When the angle ∠C is 0°, the extension direction of the intake pipe 3 is tangent to the outer cylinder 11, and the oil gas flows along the circumferential direction of the outer cylinder 11. That is, it performs circumferential motion within the outer lumen 10, and at the same time there are upward and downward flow components, resulting in an overall spiral shape. Unless otherwise specified, the direction in which the oil gas flows along the circumferential direction of the inner cylinder 2 refers to circumferential flow ignoring vertical flow.

[0034] Preferably, the end face of the intake pipe 3 is designed to be arc-shaped, preferably an arc shape that matches the radius of curvature of the outer cylinder 11, so that the intake direction coincides with the extension along the circumferential direction of the outer cylinder 11, thereby further promoting the circumferential motion of the oil gas around the inner cylinder 2.

[0035] Furthermore, if we draw an external tangent line to the inner cylinder 2 passing through the aforementioned base point and define this as the second cross-section, the angle between the first and second cross-sections is α°. When the angle ∠C is between 0° and α°, the oil gas flows roughly along the circumferential direction of the outer cylinder 11. When the angle ∠C is greater than α°, the oil gas is obstructed by the inner cylinder 2, resulting in a large pressure drop.

[0036] When the angle ∠C is 90°, the intake direction of the intake pipe 3 is perpendicular to the outer cylinder 11, and the intake direction is toward the central axis along the radial direction of the outer cylinder 11. After the oil gas flows toward the central axis and hits the inner cylinder 2, it splits into two branches, flowing clockwise and counterclockwise along the circumferential direction of the inner cylinder 2, respectively, and simultaneously generating upward and downward flow components.

[0037] In the various connection methods described above, when the oil gas undergoes a spiral motion similar to a circumference within the outer lumen 10, the lubricating oil is separated by centrifugal force, adheres, and eventually drips down to the bottom along the inner wall of the outer cylinder 11. As those skilled in the art will understand, when the lower buffer space is relatively large, the oil gas may enter the inner lumen 20 through the filter holes 23 before reaching the bottom.

[0038] The area and arrangement of the filter holes 23 on the inner cylinder 2 are key to balancing the lubricating oil separation effect and pressure drop. In the present invention, the inner cylinder 2 includes a solid cylinder wall 21 and a filter hole cylinder wall 22, and the filter hole cylinder wall 22 is provided with a plurality of the filter holes 23 that connect the outer lumen 10 and the inner lumen 20.

[0039] Preferably, the solid cylinder wall 21 and the pore cylinder wall 22 are arranged along the circumferential direction of the inner cylinder 2, and the inner cylinder 2 and the outer cylinder 11 are arranged as follows: After the oil gas enters the outer lumen 10, it flows along the circumferential direction of the inner cylinder 2 or the outer cylinder 11, and in the first rotation of the helical motion, it first passes through the solid cylinder wall 21 and then through the pore cylinder wall 22. That is, the first half of the rotation passes through the path of the solid cylinder wall 21, and the second half of the rotation flows through the pore cylinder wall 22.

[0040] In this invention, the oil gas flowing into the outer lumen 10 is highly velocatile and first passes through the solid cylinder wall 21. The lubricating oil is separated from the refrigerant gas under the combined action of centrifugal force and gravity, and is "bounced" off the inner wall of the outer cylinder 11, dripping downwards and accumulating at the bottom. In this process, even small droplets of lubricating oil are smoothly separated. As the oil gas flows through the filter hole cylinder wall 22, some of the oil gas flows through the filter holes 23 into the inner lumen 20, at which point the filter hole cylinder wall 22 can filter out some more lubricating oil.

[0041] Compared to embodiments in which the solid cylinder wall 21 is located above the pore wall 22, in the present invention, the solid cylinder wall 21 and the pore wall 22 are arranged along the circumferential direction of the inner cylinder 2. As a result, the distance the oil gas travels around the solid cylinder wall 21 is less than one full rotation, and it quickly enters the region corresponding to the pore wall 22, passes through the pores 23, and enters the lumen 20. Consequently, the pressure drop is small and can be controlled to 0.3 BAR or less.

[0042] In embodiments where filter holes 23 are opened across the entire surface of the inner cylinder 2, on the one hand, small droplet-shaped lubricating oil enters the lumen 20 through the filter holes 23 along with the refrigerant gas and is discharged, resulting in poor separation. On the other hand, although the initial pressure drop is small because the inner cylinder 2 is open all over, the separated lubricating oil adheres to the wall of the inner cylinder 2, obstructing the passage of oil gas and causing a large pressure drop. Also, the separated lubricating oil is easily carried into the lumen 20 by the impact of subsequent oil gas. However, in the inner cylinder 2 of the present invention, a portion is filter holes 23 along the circumferential direction, and a portion is a solid cylinder wall 21, so the oil gas flows through the solid cylinder wall 21 in the first half of the circumference, and most of the lubricating oil can be separated. Therefore, the amount of lubricating oil adhering to the filter hole cylinder wall 22 is relatively small, there is little obstruction to the passage of subsequent oil gas, the overall pressure is stable, and both pressure drop and oil gas separation effects are achieved.

[0043] The positional relationship between the physical cylinder wall 22 and the intake pipe 3 also affects the separation effect. Specifically, the intake pipe 3 is connected to a projection area where the physical cylinder wall 21 is projected radially onto the outer cylinder 11. That is, the intake pipe 3 is connected to the portion of the outer cylinder 11 corresponding to the physical cylinder wall 21, ensuring that after the oil gas enters the outer lumen 10 from the intake pipe 3, it first flows through the physical cylinder wall 21 and then through the filter hole cylinder wall 22.

[0044] In some embodiments, as shown in Figures 8 and 9, the connection between the intake pipe 3 and the outer cylinder 11 is adjacent to the boundary of the projection area, and the intake direction is toward the side with the physical cylinder wall 21. That is, in the direction in which the oil gas flows along the circumferential direction of the inner cylinder 2, the physical cylinder wall 21 is located downstream of the location of the intake pipe 3, and the filter hole cylinder wall 22 is located upstream of the location of the intake pipe 3. The oil gas flows from one boundary of the physical cylinder wall 21 to the other boundary, and then enters the region corresponding to the filter hole cylinder wall 22. Because the flow distance around the physical cylinder wall 21 is long, more lubricating oil can be separated by centrifugal force.

[0045] Preferably, the angle ∠C is between 0° and α°, and the oil gas generally undergoes circumferential motion around the solid cylinder wall 21 and is not obstructed by the inner cylinder 2, so a large amount of lubricating oil can be centrifuged.

[0046] Specifically, the length of the physical cylinder wall 21 in the circumferential direction of the inner cylinder 2 is [1 / 2, 3 / 4] of the circumference of the inner cylinder 2, ensuring that the oil gas flows around the physical cylinder wall 21 for at least half a stroke, allowing for centrifugal separation of a large amount of lubricating oil. At the same time, since it flows around the filter hole cylinder wall 22 for at least 1 / 4 of a stroke, the pressure drop is relatively small.

[0047] In one specific embodiment, as shown in Figure 9, of the two boundary lines between the solid cylindrical wall 21 and the filtration pore cylindrical wall 22, the first boundary line is adjacent to the intake pipe 3, the second boundary line is away from the intake pipe 3, and the intake pipe 3 is perpendicular to the plane containing the central axis of the inner pipe 2. As a result, oil gas entering the outer lumen 10 from any position on the end face of the intake pipe 3 can flow around the solid cylindrical wall 21 in a half-circle stroke.

[0048] In another embodiment, as shown in Figures 10 and 11, the intake pipe 3 corresponds to an intermediate region in the circumferential direction of the cylindrical wall of the physical body 21, preferably to the true center of the physical cylindrical wall 21. Therefore, the connection method between the intake pipe 3 and the outer cylinder 11 is diversified, and regardless of the intake direction, the oil gas can pass through the physical cylindrical wall 21 and the filter hole cylindrical wall 22 in sequence.

[0049] In one preferred embodiment, as shown in Figure 10, the extension direction of the intake pipe 3 is tangential to the outer cylinder 11, and ∠C is 0°.

[0050] In one specific embodiment, both the first and second boundary lines are parallel to the central axis of the inner cylinder 2, and the plane containing the two boundary lines is parallel to the intake pipe 3. Oil gas flowing out from any position at the end of the intake pipe 3 can travel a longer path along the solid cylinder wall 21, and in this process the oil gas is well mixed and the flow is stable.

[0051] Preferably, the length of the filter hole cylinder wall 22 in the circumferential direction of the inner cylinder 2 is 1 / 2 or less of the circumference of the inner cylinder 2, preferably 1 / 4 or more, to balance the oil-gas separation effect and pressure drop.

[0052] In another preferred embodiment, as shown in Figure 11, the extension direction of the intake pipe 3 is perpendicular to the outer cylinder 11, and ∠C is 90°. After the oil gas enters the outer lumen 10, it flows to both sides, branches out, and encloses the inner cylinder 2.

[0053] To ensure that the oil gas on both sides flows a certain distance along the solid cylinder wall 21, the first boundary line and the second boundary line are both parallel to the central axis of the inner cylinder 2, and the angle between the plane containing the boundary line and the central axis and the intake pipe 3 is between 45° and 180°.

[0054] In one specific embodiment, the plane containing the two boundary lines is perpendicular to the intake pipe 3, and therefore the flow paths of the oil gas flowing on both sides are symmetrical, and the operation is stable. Preferably, the length of the filter hole cylinder wall 22 in the circumferential direction of the inner cylinder 2 is 1 / 2 or less of the circumference of the inner cylinder 2, preferably 1 / 4 or more. The oil gas flows along a long path along the solid cylinder wall 21, ensuring the separation effect of the lubricating oil. Furthermore, the smaller the length of the filter hole cylinder wall 22 in the circumferential direction, the better the separation effect of the lubricating oil.

[0055] Furthermore, both the area of ​​the filter tube wall 22 and the size of the filter holes 23 play important roles in the oil-gas separation effect and pressure balance.

[0056] Preferably, the area occupancy rate of the filter hole wall 22 on the inner cylinder 2 is between 1 / 4 and 1 / 2, and the area occupancy rate of the physical cylinder wall 21 is between 1 / 2 and 3 / 4. As a result, the oil gas passes through more than half of the physical cylinder wall 21, most of the lubricating oil is repelled by the wall of the outer cylinder 11, and the amount of lubricating oil entering the inner lumen 20 is reduced.

[0057] Furthermore, the area occupancy rate of the multiple pores 23 on the pore tube wall 22 is 50% to 80%, and the larger the area occupancy rate, the smaller the pressure drop.

[0058] Preferably, the multiple pores 23 are uniformly distributed on the entire pore tube wall 22, the structural strength of the entire pore tube wall 22 is uniform and resistant to damage. Alternatively, the area occupancy of the multiple pores 23 on the pore tube wall 22 gradually increases along the direction of arrangement of the physical tube wall 21 and the pore tube wall 22, i.e., along the direction of oil-gas flow. In one specific embodiment, the area of ​​the pores 23 is the same as the area of ​​the pores 23, and the number density of the pores 23 gradually increases along the direction of oil-gas flow. In another specific embodiment, the number density of the pores 23 is the same along the direction of oil-gas flow, and the opening area of ​​the pores 23 gradually increases. Here, the number density refers to the number of pores 23 provided in a unit area.

[0059] Furthermore, the inventor's research has revealed the following: The lubricating oil content in the oil gas differs at different heights, and the oil gas separation effect can be further enhanced by adjusting the width of the solid cylinder wall 21 and the filter hole cylinder wall 22 along the circumferential direction of the inner cylinder 2 according to the lubricating oil content at the corresponding height.

[0060] In this invention, the width of the filter hole cylinder wall 22 along the circumferential direction of the inner cylinder 2 changes from top to bottom. In regions with a high lubricating oil content, the width of the physical cylinder wall 21 is large, and a large amount of lubricating oil is separated by centrifugal action. In regions with a high lubricating oil content, the width of the filter hole cylinder wall 22 is large, and the filter holes 23 balance the pressure between the outer lumen 10 and the inner lumen 20, reducing the pressure drop.

[0061] In some embodiments, the width of the filter tube wall 22 along the circumferential direction of the inner cylinder 2 differs at different heights. As a result, the length over which the fluid flows along the circumferential direction of the inner cylinder 2 differs at different heights, and the lubricating oil separation effect also differs.

[0062] Preferably, the width of the pore tube wall 22 gradually increases from top to bottom or increases in steps, with a larger width of the solid tube wall 21 in the upper region, resulting in a better separation effect of lubricating oil. On the other hand, a larger width of the pore tube wall 22 in the bottom region can play a role in balancing the pressure of the inner lumen 20 and the outer lumen 10.

[0063] In one specific embodiment, referring to Figures 13-15, the first boundary line between the solid cylinder wall 21 and the pore cylinder wall 22 is parallel to the central axis of the inner cylinder 2, and the second boundary line is inclined from top to bottom along the circumferential direction of the inner cylinder 2.

[0064] In another specific embodiment, referring to Figure 16, both the first boundary line and the second boundary line are inclined from top to bottom along the circumferential direction of the inner cylinder 2.

[0065] In yet another specific embodiment, the upper ends of the first boundary line and the second boundary line of the solid cylinder wall 21 and the pore cylinder wall 22 intersect, and / or their lower ends intersect. Preferably, the upper end is opposite the top of the inner cylinder 2, and the lower end is opposite the bottom of the inner cylinder 2.

[0066] In yet another embodiment, referring to Figures 17 to 19, the distance from the intake pipe 3 to the upper end of the outer cylinder 11 is between 1 / 4 and 1 / 2 of the height of the outer cylinder 11. Therefore, the lubricating oil content mixed in the oil gas entering from the intake pipe 3 is highest, and as the airflow spirals upward or downward, the lubricating oil content in the oil gas relatively decreases. Consequently, the width of the filter hole cylinder wall 22 gradually increases or increases in steps from the connection point between the intake pipe 3 and the outer cylinder 11 in both upward and downward directions. That is, the width of the filter hole cylinder wall 22 initially decreases from top to bottom, and then increases. When the oil gas entering from the intake pipe 3 flows through the first rotation, the distance it flows through the solid cylinder wall 21 is the longest, and the distance it flows through the filter hole cylinder wall 22 is the shortest, so that more lubricating oil can be separated by centrifugal force or adhered to the inner wall of the outer cylinder 11. On the other hand, after flowing upward and downward, the lubricating oil content decreases significantly, so by flowing as quickly as possible into the relatively wide filter tube wall 22, it can play a role in balancing the pressure in the inner lumen 20 and the outer lumen 10.

[0067] In one specific embodiment, referring to Figure 17, the first boundary line between the solid cylinder wall 21 and the pore cylinder wall 22 is parallel to the central axis of the inner cylinder 2, and the second boundary line is inclined from top to bottom along the circumferential direction of the inner cylinder 2. In another specific embodiment, referring to Figure 18, both the first and second boundary lines are inclined from top to bottom along the circumferential direction of the inner cylinder 2. In yet another embodiment, referring to Figure 19, the first and second boundary lines between the solid cylinder wall 21 and the pore cylinder wall 22 intersect at a position corresponding to the intake pipe 3.

[0068] In all of the above embodiments, the intake pipe 3 is located within a projection area where the physical cylindrical wall 21 is projected radially onto the outer cylinder 11, and is provided near the first or second boundary line, with the intake direction of the intake pipe 3 being toward the side with the physical cylindrical wall 21. After the oil gas enters the outer lumen 10, it flows from one side of the physical cylindrical wall 21 to the other, and the flow path is maximized.

[0069] In the present invention, any connection method between the intake pipe 3 and the outer cylinder 11, any structure of the inner cylinder, and any relative positional relationship between the inner cylinder 2 and the intake pipe 3 can be used in combination, except in cases where they contradict the principles described herein. In all cases, the pressure drop can be controlled to 0.3 BAR or less, and the oil-gas separation effect can be improved to 90% or more.

[0070] The following describes the connection method between the oil drain pipe 5 and the outer shell 1.

[0071] In the present invention, the oil drain pipe 5 is connected to the bottom of the outer shell 1, and the upper end of the oil drain pipe 5 is H1 higher than the lower end of the outer shell, and the distance between the oil drain pipe 5 and the side wall of the outer shell 1 is H2, where H1:H2≧(√3) / 2. Therefore, even when the oil gas separator 100 is tilted at 30°, the oil level can continue to cover the upper end of the oil drain pipe 5, and no pressure leakage occurs.

[0072] Preferably, the drain pipe 5 is connected to the central position of the bottom of the outer shell 1, and the distance from the drain pipe 5 to any side wall of the outer shell 1 is the same. If the drain pipe 5 is offset from the central position of the bottom of the outer shell 1, the shortest distance between the drain pipe and any side wall of the outer shell 1 is H2.

[0073] Specifically, the oil drain pipe 5 is connected to the bottom cap 13, and a portion of the oil drain pipe 5 extends through the bottom cap 13 into the outer cylinder 11. The upper end of the oil drain pipe 5 is H1 higher than the bottom wall, and the distance between the oil drain pipe 5 and the outer cylinder 11 is H2.

[0074] Preferably, the bottom cap 13 is pyramidal or conical in shape, with a narrow bottom and a wide top. This allows less lubricating oil to be stored in the oil-gas separator 100 at the same oil level, and most of the lubricating oil to flow within the refrigeration circulation system.

[0075] Furthermore, the upper end of the oil drain pipe 5 extends into the inner cylinder 2, and when the vehicle goes uphill, the inner cylinder 2 obstructs the flow of lubricating oil to some extent, which is advantageous for liquid sealing.

[0076] Furthermore, the 1 to 4 rows of filter holes 23 located at the bottom of the inner cylinder 2 can be called oil passage holes, and the upper end of the oil drain pipe 5 is higher than the oil passage holes. That is, the liquid level of the lubricating oil is higher than the filter holes 23 at the lowest end of the inner cylinder 2, and the lubricating oil in the outer lumen 10 can flow between the inner lumen 20 and the outer lumen 10 in a timely manner through the filter holes 23 / oil passage holes and the dripping holes 71. This is advantageous for liquid sealing even when the road surface is uneven.

[0077] Furthermore, an electronic switch can be installed in the oil drain pipe 5 to allow for intermittent opening and refueling. Specifically, the refueling cycle and refueling time can be set as needed; for example, the cycle is 5 minutes and the opening time is 2 seconds.

[0078] Furthermore, the oil-gas separator 100 includes a fixing structure 6 for fixing the outer cylinder 11 to the application environment. The fixing structure 6 is connected to the outer cylinder 11 and is installed facing the intake pipe 3. In other words, the fixing structure 6 is installed facing the region where the intake impact force is greatest, thereby enhancing the stability of the oil-gas separator 100.

[0079] In this invention, the side of the oil-gas separator 100 is fixed to the refrigerated truck, and when the vehicle is running, vibrations are transmitted directly to the outer cylinder 11 rather than to the bottom. This is advantageous for the dripping of lubricating oil on the inner wall of the outer cylinder 11, but the agitation of the lubricating oil that has accumulated at the bottom is reduced.

[0080] The present invention further provides a refrigeration system which includes any of the oil-gas separators 100 described above.

[0081] In one specific embodiment, the refrigeration system includes a compressor, a condenser, a throttle element, and an evaporator, the oil-gas separator 100 is installed between the compressor and the condenser, and the intake pipe 3 communicates with the outlet of the compressor, the exhaust pipe 4 communicates with the inlet of the condenser, and the oil drain pipe 5 communicates with the inlet of the compressor.

[0082] The oil-gas separator 100 ensures that the lubricating oil leaking from the compressor is returned to the compressor in a timely manner, guaranteeing the compressor's normal operation. At the same time, it prevents the lubricating oil from entering the downstream condenser and evaporator, thus preventing it from affecting heat dissipation and cooling.

[0083] In another specific embodiment, the refrigeration system includes a first compressor, a second compressor, a condenser, a throttle element, an evaporator, and two oil-gas separators 100. By connecting the first and second compressors in series, two-stage compression is achieved, enhancing the cooling effect.

[0084] One of the oil-gas separators 100 is installed between the first compressor and the second compressor, with the intake pipe 3 communicating with the outlet of the first compressor, the exhaust pipe 4 communicating with the inlet of the second compressor, and the oil drain pipe 5 communicating with the inlet of the first compressor. This is to return the lubricating oil discharged from the first compressor back into the first compressor in a timely manner, and the refrigerant after the lubricating oil has been separated enters the second compressor for secondary compression. The other oil-gas separator 100 is installed between the second compressor and the condenser, with the intake pipe 3 communicating with the outlet of the second compressor, the exhaust pipe 4 communicating with the inlet of the condenser, and the oil drain pipe 5 communicating with the inlet of the second compressor. This is to return the lubricating oil discharged from the second compressor back into the second compressor in a timely manner, ensuring the normal operation of the second compressor. At the same time, lubricating oil is prevented from entering the downstream condenser and evaporator, so as not to affect heat dissipation and cooling.

[0085] By employing the aforementioned oil-gas separator 100, the oil return effect is achieved at over 90%, ensuring the normal operation of the compressor. Furthermore, the pressure drop in the oil-gas separator 100 does not exceed 0.3 BAR, and the overall pressure drop of the refrigeration system does not exceed 3 BAR.

[0086] Preferably, in the above embodiment, at least the oil-gas separators 100 are connected in series to form multi-stage oil separation, the exhaust pipe 4 of the upstream oil-gas separator 100 is connected to the intake pipe 3 of the downstream oil-gas separator 100, and the oil discharge pipe 5 of each oil-gas separator 100 is connected to the inlet of the compressor. In multi-stage oil separation, even after lubrication oil separation and pressure drop accumulate, the oil-gas separation effect is better and the pressure drop remains relatively small.

[0087] As those skilled in the art will understand, in the refrigerant circulation process, any remaining lubricating oil also returns to the compressor along with the operation of the refrigerant. Furthermore, when assembling the refrigeration system, the amount of lubricating oil should be appropriately increased to avoid oil shortages caused by some lubricating oil remaining in other parts of the system, such as the evaporator.

[0088] Furthermore, a liquid receiver with an oil-returning function can be added between the condenser and the throttle element of the above-mentioned refrigeration system. By further oil-returning through the liquid receiver, the effect is improved.

[0089] The refrigeration system of the present invention can be used in refrigerated vehicles, and the compressor is preferably a rotary compressor, which has a large oil discharge volume. The normal operation of the compressor can be ensured through the oil separator 100.

[0090] In general, in the oil-gas separator 100 of the present invention, since the solid cylindrical wall 21 and the filter hole cylindrical wall 22 are arranged along the circumferential direction of the inner cylinder 2, when the oil-gas entering the outer lumen 10 undergoes helical motion, it first passes through the solid cylindrical wall 21 and then through the filter hole cylindrical wall 22. This results in a good lubricating oil separation effect and a small pressure drop.

[0091] The structure, features, and effects of the present invention have been described in detail above based on the embodiments shown in the drawings. Although the above describes only better embodiments of the present invention, the present invention is not limited to the scope shown in the drawings, and any modifications or equivalent embodiments based on the concept of the present invention should all be within the scope of protection of the present invention, as long as they do not exceed the spirit encompassed by the description and illustrations.

Claims

1. An oil-gas separator, The outer shell, including the outer cylinder, An inner cylinder located within the outer cylinder, wherein an outer lumen is formed between the outer cylinder and the inner cylinder, an inner lumen is formed within the inner cylinder, the inner cylinder includes a solid cylinder wall and a pore cylinder wall, the pore cylinder wall has a plurality of pores that connect the outer lumen and the inner lumen, and the solid cylinder wall and the pore cylinder wall are arranged along the circumferential direction of the inner cylinder, An intake pipe connected to the outer cylinder, An exhaust pipe connected to the upper part of the outer shell, The drain pipe connected to the bottom of the outer shell, An oil-gas separator that includes an oil-gas separator.

2. In the direction in which the oil gas entering from the intake pipe flows along the circumferential direction of the inner cylinder, the solid cylinder wall is located downstream of the location of the intake pipe, and the filter hole cylinder wall is located upstream of the location of the intake pipe. The oil-gas separator according to claim 1.

3. The intake pipe is connected to a projection area in which the solid cylindrical wall is projected radially onto the outer cylinder. The oil-gas separator according to claim 1.

4. The connection between the intake pipe and the outer cylinder is adjacent to the boundary of the projection area. Using the connection between the intake pipe and the outer cylinder as a base point, draw an outer tangent line of the outer cylinder passing through the base point and define this as the first cross-section. Draw an outer tangent line of the inner cylinder passing through the base point and define this as the second cross-section. Let ∠C be the angle between the intake pipe and the first cross-section, and let α° be the angle between the first cross-section and the second cross-section. Then, angle ∠C is between 0° and α°. The oil-gas separator according to claim 3.

5. The area occupancy rate of the pore tube wall on the inner cylinder is between 1 / 4 and 1 / 2, or The plane to which the two boundary lines between the filter hole cylinder wall and the solid cylinder wall belong is perpendicular to the intake pipe, and the length of the filter hole cylinder wall along the circumferential direction of the inner cylinder is 1 / 4 to 1 / 2 of the circumference of the inner cylinder. The oil-gas separator according to claim 1.

6. The area occupancy rate of the multiple pores on the wall of the pore tube is 50% to 80%. The oil-gas separator according to claim 1.

7. Multiple pores are uniformly distributed on the wall of the pore tube. The oil-gas separator according to claim 1.

8. Along the alignment direction of the solid cylindrical wall and the pore cylindrical wall, the area occupancy ratio of the multiple pores on the pore cylindrical wall increases gradually or in stages. The oil-gas separator according to claim 1.

9. Multiple pores have the same area, and the number density of pores gradually increases, or The number density of pores is the same, and the pore opening area gradually increases. The oil-gas separator according to claim 8.

10. From top to bottom, the width of the pore tube wall changes along the circumferential direction of the inner cylinder. The oil-gas separator according to claim 1.

11. The width of the pore tube wall at different height positions differs along the circumferential direction of the inner cylinder, and the width of the pore tube wall gradually or stepwise increases from top to bottom, or The width of the filter tube wall increases gradually or in steps in both upward and downward directions from the connection point between the intake pipe and the outer cylinder. The oil-gas separator according to claim 10.

12. The bottom of the outer cavity and the bottom of the inner cavity are in communication, the upper end of the drain pipe is H1 higher than the bottom end of the outer shell, the distance between the drain pipe and the side wall of the outer shell is H2, and H1:H2 ≥ (√3) / 2. The oil-gas separator according to claim 1.

13. The pressure drop of the oil-gas separator is 0.3 BAR or less, and the separation rate of lubricating oil in the oil-gas is 90% or more. An oil-gas separator according to any one of claims 1 to 12.

14. A cooling system including a compressor, a condenser, a throttle, and an evaporator, The cooling system further includes an oil-gas separator according to any one of claims 1 to 13, wherein the oil-gas separator is provided between the compressor and the condenser, and the intake pipe communicates with the outlet of the compressor, the exhaust pipe communicates with the inlet of the condenser, and the oil drain pipe communicates with the inlet of the compressor. Cooling system.

15. A cooling system comprising a first compressor, a second compressor, a condenser, a throttle device, and an evaporator, The cooling system further includes two oil-gas separators according to any one of claims 1 to 13, one of which is provided between the first compressor and the second compressor, with an intake pipe communicating with the outlet of the first compressor, an exhaust pipe communicating with the inlet of the second compressor, and an oil drain pipe communicating with the inlet of the first compressor; and the other oil-gas separator is provided between the second compressor and the condenser, with an intake pipe communicating with the outlet of the second compressor, an exhaust pipe communicating with the inlet of the condenser, and an oil drain pipe communicating with the inlet of the second compressor. Cooling system.

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