An oil separator for a refrigeration system

Abstract

The application discloses a kind of oil separators for refrigeration system, belong to oil-gas separation technical field, including cylinder, including for leading into oil-gas mixture into cylinder import, first oil separation space, oil return space below first oil separation space and with first oil separation space communication, second oil separation space with oil return space communication and outlet for discharging gaseous refrigerant with second oil separation space communication;Several oil-gas separation pieces are arranged axially and several oil-gas separation pieces are arranged at first oil separation space, and oil-gas separation piece is continuously bent structure along horizontal direction, and the bending direction of adjacent bending section is opposite, to form sequentially spaced arrangement wave crest and wave trough, and the separation gap for oil-gas mixture is formed between adjacent two oil-gas separation pieces, and through the continuous bending structure of axially arranged oil-gas separation piece, the contact area is increased while keeping lower air resistance, and the flow distribution of each separation gap is uniform, to improve oil-gas separation effect.

Description

Technical Field

[0001] This invention belongs to the field of oil-gas separation technology, specifically relating to an oil separator for a refrigeration system. Background Technology

[0002] The oil separator is a core component of a vapor compression refrigeration system, installed between the compressor's discharge port and the condenser. During compressor operation, some refrigeration oil is vaporized at high temperatures or entrained as droplets by a high-speed airflow, mixing with the high-pressure gaseous refrigerant before being discharged together. The function of the oil separator is to separate the lubricating oil from this mixture, allowing it to return to the compressor crankcase or suction side via the oil return pipe, ensuring proper compressor lubrication. Simultaneously, it allows the purified gaseous refrigerant, now free of excess oil, to enter the condenser for further circulation, preventing oil film from adhering to the heat exchanger tube walls and reducing heat exchange efficiency.

[0003] In the field of oil-gas separation technology, filtration and interception structures such as filter screens and filter elements have always been commonly used separation methods. Chinese utility model patent CN222617250U discloses "a liquid receiver, a rolling rotor compressor, and an air conditioner," which features a filter assembly inside the cylinder. The filter assembly includes a support frame and a filter screen disposed on the upper end of the support frame. The support frame has fish-eye vent holes, and one side of the fish-eye vent holes has a shielding surface. The oil-gas mixture is first filtered and intercepted by the filter screen, and then the fish-eye vent holes and the shielding surface work together to cause the two airflows to collide and merge, achieving secondary separation by utilizing the reduced flow velocity after the collision.

[0004] Chinese invention patent CN116878191A discloses an "oil separator and refrigeration equipment," which includes a filter assembly within a separation chamber. This assembly comprises a filter cartridge compartment for holding multiple filter elements, with each filter element exhibiting progressively higher filtration precision in the airflow direction. The oil-gas mixture is separated into oil droplets through the step-by-step filtration and interception of the multiple filter elements. These two patent documents, from the refrigeration industry and the residential / commercial air conditioning industry respectively, reflect the widespread technical understanding of using filters and filter elements for oil-gas separation across various branches of the refrigeration industry.

[0005] Industrial chillers are typically used in industrial applications such as chemical process cooling, food freezing, cryogenic storage, pharmaceutical reactor temperature control, and gas liquefaction and separation. These applications usually require the refrigeration system to operate stably and continuously over a wide temperature range, and the evaporation temperature of the chiller during operation is much lower than that of conventional household and commercial air conditioners. The evaporation temperature of household and commercial air conditioners is generally around 5~10℃, and the evaporation temperature of commercial refrigeration and freezing equipment is around -25~-10℃, while the evaporation temperature of industrial chillers can be as low as -100~-30℃, and their exhaust temperature can easily exceed 100℃.

[0006] Under these low-temperature, high-compression-ratio operating conditions, the mixing ratio and state of oil and gas differ significantly from those in conventional air conditioning. When the exhaust temperature is low, the lubricating oil has a high viscosity and surface tension, and the discharged oil mainly exists as large droplets in the gaseous refrigerant, with a noticeable density difference between the oil and gas. As the exhaust temperature increases, especially in the range above 90-100℃, the viscosity of the lubricating oil decreases significantly, the surface tension decreases, and some of the lubricating oil vaporizes. The oil in the exhaust no longer exists solely as large droplets but instead contains a large amount of tiny oil mist and oil vapor. These tiny oil mist particles are suspended in the refrigerant gas and do not easily settle, resulting in a more uniform distribution of the oil phase in the mixture, and a blurred physical interface between the gas and liquid phases.

[0007] Under these operating conditions, traditional methods of oil-gas separation using filters or mesh belts have limitations. Filters and mesh belts primarily rely on the direct collision and interception of oil droplets with the filter medium for separation, and their separation efficiency depends on the droplet size and the interception area of ​​the filter medium. When the size of oil mist particles in the exhaust decreases and the proportion of oil vapor increases, tiny oil mist particles easily bypass the filter medium and are discharged with the airflow, resulting in insufficient effective contact area to intercept the high proportion of small-diameter oil mist particles. To improve separation efficiency, it is necessary to increase the filter pore size and the number of filter layers. However, increasing the density and thickness of the filter medium leads to a rapid increase in ventilation resistance, increasing the compressor exhaust back pressure, increasing compressor power consumption, and reducing the overall energy efficiency of the refrigeration system. At the same time, filters with small pore sizes are easily clogged by oil and impurities. In the scenario of long-term continuous operation of industrial refrigeration units, the filter clogging speed is relatively fast, and the maintenance cycle is shortened. Therefore, under the high temperature and high pressure conditions of industrial refrigeration units, traditional filter and mesh belt oil separators are insufficient in terms of effective contact area, ventilation volume, separation resistance, and long-term operational stability. Summary of the Invention

[0008] The purpose of this invention is to provide an oil separator for a refrigeration system, which can increase the contact area while maintaining low ventilation resistance and improve the oil-gas separation effect.

[0009] To achieve the above objectives, embodiments of the present invention provide an oil separator for a refrigeration system, comprising: a cylinder, including an inlet for introducing an oil-gas mixture into the cylinder, a first oil separation space communicating with the inlet and extending axially, a return oil space located below and communicating with the first oil separation space, a second oil separation space communicating with the return oil space, and an outlet communicating with the second oil separation space and used to discharge gaseous refrigerant. The oil-gas separator has several components, which are arranged axially and spaced apart in the first oil separation space. The oil-gas separator has a continuous bending structure in the horizontal direction, and the bending directions of adjacent bending sections are opposite to form wave peaks and troughs arranged in sequence. A separation gap is formed between two adjacent oil-gas separators to allow the oil-gas mixture to pass through. The inlet is located above several oil-gas separators to axially guide the oil-gas mixture from top to bottom into several separation gaps. The sidewalls of the oil-gas separators are used to adsorb oil droplets and can guide the adsorbed and gathered oil droplets to the return oil space. The separated gaseous refrigerant enters the second oil separation space after passing through the return oil space and is discharged at the outlet.

[0010] In one possible implementation, a partition plate is provided axially inside the cylinder, which divides the inside of the cylinder into a first oil separation space and a second oil separation space in the axial direction. The return oil space is located below the first oil separation space and the second oil separation space, and the outlet is located above the second oil separation space. The second oil separation space also contains several oil-gas separators arranged axially at intervals.

[0011] In one possible implementation, one horizontal end wall of the oil-gas separator is connected to the inner wall of the cylinder, and the other end wall is connected to the inner wall of the cylinder or a partition plate, so as to form a separation gap together with the inner wall of the cylinder and / or the cover plate, and to isolate adjacent separation gaps from each other.

[0012] In one possible implementation, two adjacent oil-gas separators are parallel to each other so that the separation gaps are spaced evenly in the horizontal direction, and several oil-gas separators are arranged at equal intervals so that the spacing between two adjacent separation gaps is equal.

[0013] In one possible implementation, the first oil separation space and the second oil separation space are arranged symmetrically relative to the partition plate, and the separation gap spacing in the first oil separation space is equal to the separation gap spacing in the second oil separation space, so that the flow rates of the first oil separation space and the second oil separation space are the same.

[0014] In one possible implementation, the bends of the continuous bending structure have an arc-shaped transition, so that the cross-section of the oil-gas separator in the horizontal direction is wavy.

[0015] In one possible implementation, the bends of the continuous bending structure have acute angle transitions, so that the cross-section of the oil-gas separator along the horizontal direction is serrated.

[0016] In one possible implementation, the cylinder is a split structure, including an oil separator cylinder, a top cover covering the upper part of the oil separator cylinder, and a bottom cover fastened to the lower part of the oil separator cylinder; The oil separator includes a first oil separation space, a partition plate, and a second oil separation space. The oil return space is located inside the bottom cover, while the inlet and outlet are located on the top cover.

[0017] In one possible implementation, the oil separator cylinder, the separator plate, and the oil-gas separator are integrally die-cast.

[0018] In one possible implementation, the width of the separation gap is 16mm to 20mm.

[0019] The significant technical effect of the embodiments of the present invention is that, through the axially arranged continuous bending structure oil-gas separator, the contact area is increased while maintaining a low ventilation resistance, and the flow distribution of each separation gap is uniform, thereby improving the oil-gas separation effect. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a schematic diagram of the structure of an oil separator for a refrigeration system according to one embodiment of the present invention; Figure 2 for Figure 1 A cross-sectional view of the interior of the middle cylinder (concealing the oil-gas separator); Figure 3 This is a schematic diagram of the horizontal cross-sectional structure of the oil separator, oil-gas separator and partition plate in one embodiment of the present invention; Figure 4 This is a schematic diagram of the horizontal cross-sectional structure of the oil separator, oil-gas separator and partition plate in another embodiment of the present invention; Figure 5 This is a schematic diagram of the horizontal cross-sectional structure of the oil-gas separator in another embodiment of the present invention.

[0022] In the diagram: 100, cylinder body; 110, oil separator cylinder; 111, first oil separation space; 112, second oil separation space; 120, top cover; 121, inlet; 122, outlet; 130, bottom cover; 131, oil return space; 132, oil return pipe; 200, oil-gas separator; 210, separation gap; 300, width; 400, oil-gas separator arrangement height; 500, partition plate. Detailed Implementation

[0023] The embodiments of the technical solution of this application will now be described in detail with reference to the accompanying drawings. These embodiments are only used to more clearly illustrate the technical solution of this application and are therefore merely examples, and should not be used to limit the scope of protection of this application.

[0024] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the drawings are intended to cover non-exclusive inclusion.

[0025] In the description of the embodiments of this application, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly defined.

[0026] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0027] In the description of the embodiments of this application, the term "and / or" is merely a description of the association relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship. In the description of the embodiments of this application, the term "multiple" refers to two or more (including two), similarly, "multiple groups" refers to two or more groups (including two groups), and "multiple pieces" refers to two or more pieces (including two pieces).

[0028] In the description of the embodiments of this application, the technical terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of this application and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this application.

[0029] In the description of the embodiments of this application, unless otherwise expressly specified and limited, technical terms such as "installation", "connection", "linking", and "fixing" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components.

[0030] This invention relates to the field of refrigeration system technology. In a vapor compression refrigeration system, an oil separator is installed between the compressor's exhaust port and the condenser. The high-temperature, high-pressure gaseous refrigerant discharged from the compressor carries a portion of refrigeration oil. The oil separator needs to separate this portion of refrigeration oil from the gaseous refrigerant and return it to the compressor to ensure normal compressor lubrication. Simultaneously, it prevents lubricating oil from entering the condenser and evaporator and forming an oil film on the heat exchange tube walls, thus reducing heat exchange efficiency. In the field of industrial refrigeration equipment, refrigeration units are commonly used for chemical process cooling, food freezing, low-temperature storage, pharmaceutical reactor temperature control, and gas liquefaction separation. Their evaporation temperatures can be as low as -100 to -30°C, and exhaust temperatures easily exceed 100°C. Under these conditions, the viscosity and surface tension of the lubricating oil in the exhaust decrease, and some lubricating oil vaporizes, resulting in a large amount of fine oil mist and oil vapor in the exhaust. Traditional filter or belt-type oil separators have limited interception capabilities for fine oil mist, and the increased air resistance and clogging after the filter is densified result in deficiencies in effective contact area, airflow, and long-term operational stability.

[0031] In oil-gas separation structures, besides filters and conveyor belts, other structural forms exist. One method uses multiple small-diameter axial pipes as separation channels. The oil-gas mixture flows through each pipe from bottom to top or top to bottom, with oil droplets adhering to and settling on the inner wall of the pipes. In this structure, the cross-sectional area of ​​each pipe is small, and the contact area between the oil-gas mixture and the pipe wall is limited by the inner surface area of ​​the pipe. When the number of pipes increases, the airflow distribution among the pipes may become uneven. Some pipes have higher flow rates and velocities, resulting in shorter residence times for oil droplets and insufficient separation; others have lower flow rates, achieving better separation but with insufficient processing capacity. To increase the contact area, the pipe diameter needs to be reduced and the number of pipes increased. However, reducing the pipe diameter leads to increased ventilation resistance, and increasing the number of pipes increases the unevenness of flow distribution among the pipes.

[0032] Another method uses inclined flat or irregularly shaped plates, which are placed at a certain angle to the vertical. The oil-gas mixture flows along the inclined channel, and oil droplets settle onto the plate surface under gravity and slide down the inclined surface. The projected height of the inclined plates in the vertical direction is relatively small. For the same cylinder height of 100, the effective flow path of the oil-gas mixture is shorter, and the contact time between the oil droplets and the plate surface is limited. At the same time, the lower end of the inclined plate needs to be connected to the cylinder wall, and the fall path of oil droplets in the area below the plate may be blocked by the plate itself, making it difficult for some oil droplets to settle smoothly into the oil return space 131.

[0033] In response to the above problems, such as Figures 1-5 The illustration shows an oil separator for a refrigeration system according to an embodiment of the present invention. Through the axially arranged continuous bending structure of the oil-gas separator 200, the contact area is increased while maintaining a low ventilation resistance, and the flow distribution of each separation gap 210 is uniform, so as to improve the oil-gas separation effect.

[0034] like Figure 1 and Figure 3 As shown, the oil separator includes a cylindrical body 100, which includes an inlet 121, a first oil-separating space 111, an oil return space 131, a second oil-separating space 112, and an outlet 122. The inlet 121 is used to introduce an oil-gas mixture into the cylindrical body 100, and can be connected to the compressor's exhaust port. The first oil-separating space 111 communicates with and extends axially from the inlet 121; the oil-gas mixture enters from the inlet 121 and flows downwards into the first oil-separating space 111. The oil return space 131 is located below and communicates with the first oil-separating space 111, and is used to receive lubricating oil that settles from the first oil-separating space 111. The second oil-separating space 112 communicates with the oil return space 131; the separated gaseous refrigerant enters the second oil-separating space 112 through the oil return space 131. The outlet 122 communicates with the second oil-separating space 112 and is used to discharge the separated gaseous refrigerant; the outlet 122 can be connected to the condenser inlet.

[0035] like Figure 2 and Figure 3As shown, the oil separator also includes several oil-gas separators 200, which are axially arranged and spaced apart within the first oil separation space 111. The oil-gas separators 200 have a continuous bent structure in the horizontal direction, with adjacent bent sections having opposite bending directions to form successively spaced peaks and troughs. A separation gap 210 is formed between adjacent oil-gas separators 200 to allow the oil-gas mixture to pass through. An inlet 121 is located above the oil-gas separators 200. After entering through the inlet 121, the oil-gas mixture is axially guided from top to bottom into the separation gaps 210. The oil-gas mixture flows along the sidewall surface of the oil-gas separator 200 within the separation gaps 210. During the flow, oil droplets collide and contact with the sidewall of the oil-gas separator 200, are adsorbed by the sidewall surface, and gradually converge into larger oil droplets. Under the action of gravity, the converged oil droplets flow downwards along the sidewall of the oil-gas separator 200 and are guided to the return oil space 131. After separation, the gaseous refrigerant enters the second oil separation space 112 through the oil return space 131, and is then discharged through the outlet 122. Considering that the oil-gas separator 200 has a bent structure, it will appear as a dense array of lines in the figure. To facilitate the display of the position and height of the oil-gas separator 200, it is indicated by the arrangement height of the oil-gas separator 400.

[0036] In this example, as Figure 3 and Figure 4 As shown, the oil-gas separator 200 is axially arranged, and the oil-gas mixture flows downward through the separation gap 210. When the oil-gas mixture is discharged from the compressor exhaust port, it is under high temperature and pressure, with a high flow velocity. The gaseous refrigerant mixes with lubricating oil droplets and oil vapor to form a high-speed airflow. Because the density of the lubricating oil is greater than that of the gaseous refrigerant, the oil droplets have greater mass inertia. As the airflow enters the first oil separation space 111 and flows downward into each separation gap 210, the oil droplets simultaneously settle downwards under gravity. The settling velocity of the oil droplets, combined with the vertical velocity of the airflow, results in an actual downward-sloping motion, gradually approaching the wall and colliding with the sidewall of the oil-gas separator 200. The droplets are adsorbed by the sidewall surface and gradually converge into larger oil droplets. Under gravity, the converged oil droplets flow downwards along the sidewall of the oil-gas separator 200, guiding to the return oil space 131. The separated gaseous refrigerant enters the second oil separation space 112 after passing through the return oil space 131, and is then discharged through the outlet 122. Figure 4 For ease of viewing, only one oil-gas separator 200 is marked in the first oil separation space 111 and the second oil separation space 112. (Actual reference...) Figure 3 Multiple oil-gas separators 200 along Figure 4 The oil-gas separators 200 are arranged in parallel at intervals.

[0037] Compared to inclined separators, axially arranged separators make full use of the axial height of the cylinder 100. At the same cylinder height, the effective flow path of the oil-gas mixture is longer, the oil droplets have a longer residence time in the separation gap 210, and there are more opportunities for contact and collision with the sidewall of the separator, resulting in more thorough separation. At the same time, the axially arranged separators are unobstructed below, and the converged oil droplets flow directly downwards along the sidewall into the return oil space 131 under the action of gravity, ensuring a smooth return path.

[0038] The oil-gas separator 200 adopts a continuous bending structure with alternating crests and troughs. Compared with multiple small-diameter axial pipes, the continuous bending structure can form more sidewall area within the same cylindrical body 100 cross-sectional space. When the oil-gas mixture flows within the separation gap 210, it continuously changes its flow direction horizontally. At each change in flow direction, oil droplets collide with the wall surface of the crest or trough due to inertia. The contact area and collision probability are both higher than those of straight pipe walls. Compared with mesh belts and filters, the separation gap 210 of the continuous bending structure is an open flow channel. The oil-gas mixture does not need to pass through fine pores, resulting in lower air resistance and less clogging. At the same time, each separation gap 210 is formed by two adjacent oil-gas separators 200. The cross-sectional shape and spacing of each gap can be kept consistent through the equal-interval arrangement of the oil-gas separators 200. The flow distribution in each gap is more uniform, avoiding the problem of insufficient separation in some channels caused by uneven air intake in small-diameter pipes.

[0039] In a further example, the width 300 of the separation gap 210 is 16mm~20mm, and the width 300 is as follows: Figure 5 As shown, when the oil-gas mixture enters the separation gap 210 from the inlet 121, the airflow flows downward under the constraint of the walls of the oil-gas separators 200 on both sides. The airflow velocity is relatively uniformly distributed along the cross-section, the mainstream area is large, and the wall surface has a certain viscous resistance effect on the airflow. After the oil-gas mixture enters the separation gap 210, it flows downward at a relatively stable velocity, rather than rushing directly to the bottom in a free jet manner. The separation gap 210 is axially arranged and has a long path. As the oil droplets move downward with the airflow, they are affected by the combined effects of gravity settling and inertia, and continuously deflect towards the wall surface.

[0040] Within the separation gap 210, the oil droplet is simultaneously subjected to two velocity components: one is the axial velocity component of the airflow carrying the oil droplet downwards, and the other is the settling velocity component of the oil droplet relative to the airflow under the influence of gravity. Oil droplet separation depends on whether the droplet can settle axially onto the sidewall surface of the oil-gas separator 200 and be adsorbed during its downward movement with the airflow. With a gap width of 300 of 16mm to 20mm, the lateral distance the oil droplet travels from the gap center to the wall is 8mm to 10mm, giving it ample time to gradually approach the wall under gravity.

[0041] Under the high-temperature conditions of industrial refrigeration units, the exhaust temperature reaches 90℃ to over 100℃. The viscosity of the lubricating oil decreases, its surface tension diminishes, and the exhaust contains a large amount of fine oil mist and oil vapor. The oil mist particles are small and highly responsive to airflow. At this temperature, a gap width of 16mm to 20mm prevents excessively high airflow velocity, allowing the oil mist to remain within the separation gap 210 for a relatively long time. The fine oil mist particles collide with the wall at bends due to inertia, increasing the capture probability. Under the conditions of household and commercial air conditioners, the exhaust temperature is approximately 80℃. The lubricating oil viscosity is higher, and the discharged oil mainly exists in the form of larger droplets. The density difference between the oil and gas is significant, and the larger oil droplets settle quickly, completing lateral migration within a short axial distance. A gap width of 16mm to 20mm is sufficient for separation and provides lower ventilation resistance, reducing the compressor's exhaust back pressure.

[0042] Regarding the determination of the gap size range, the gap width of 300 should not be too small. If it is too small, it will lead to increased ventilation resistance, increased compressor exhaust back pressure, increased power consumption, and higher requirements for machining precision. It will also make it more difficult to control the spacing between two adjacent oil-gas separators 200 during casting or die casting, and it is prone to blockage due to the accumulation of oil or impurities during long-term operation. The gap width of 300 should also not be too large. If it is too large, it will further increase the lateral migration distance, prolong the time required for oil droplets to reach the wall, and result in insufficient separation at the same axial height. At the same time, an excessively large gap may cause local turbulence in the airflow, causing oil droplets that have been captured by the wall to be re-entrained into the airflow, which is not conducive to the stability of the separation effect.

[0043] In some examples, when oil-gas separation is relatively easy, such as in the operation of household or commercial air conditioners, where the exhaust temperature is low, the oil droplet size is large, and the density difference between oil and gas is significant, it is possible to meet the separation requirements by simply arranging the oil-gas separator 200 in the first oil separation space 111 of the cylinder 100. After the oil-gas mixture is separated in the first oil separation space 111, the separated gaseous refrigerant enters the second oil separation space 112 through the oil return space 131. Since the residual oil droplet content is small, the second oil separation space 112 only serves as an exhaust channel for the gaseous refrigerant, and there is no need to arrange the oil-gas separator 200 inside it. This solution has a simpler structure and lower manufacturing cost. When oil-gas separation is more difficult, such as in the low-temperature, high-compression ratio operation of industrial refrigeration machines, where the exhaust temperature is high and the exhaust contains a large amount of tiny oil mist and oil vapor, several axially arranged oil-gas separators 200 can also be arranged at intervals in the second oil separation space 112. A partition plate 500 is axially arranged inside the cylinder 100, dividing the interior of the cylinder 100 into a first oil separation space 111 and a second oil separation space 112. The return oil space 131 is located below the first oil separation space 111 and the second oil separation space 112, and the outlet 122 is located above the second oil separation space 112. After the oil-gas mixture undergoes primary separation in the first oil separation space 111, the residual oil droplets carried by the gaseous refrigerant flow through the return oil space 131 and enter the second oil separation space 112. Secondary separation occurs in the separation gap 210 within the second oil separation space 112, where the residual oil droplets are adsorbed by the sidewall of the oil-gas separator 200 and guided to the return oil space 131, further improving the oil-gas separation efficiency. The inlet 121 and outlet 122 are structurally interchangeable; either one can be used as the inlet 121, and the other as the outlet 122, to adapt to different installation site piping layouts.

[0044] In further examples, such as Figure 3 and Figure 4 As shown, one horizontal end wall of the oil-gas separator 200 is connected to the inner wall of the cylinder 100, and the other end wall is connected to the inner wall of the cylinder 100 or the partition plate 500. The oil-gas separator 200, the inner wall of the cylinder 100, and / or the partition plate 500 together enclose a separation gap 210. Adjacent separation gaps 210 are isolated from each other in the horizontal direction by the oil-gas separator 200, and each separation gap 210 is an independent axial flow channel. After the oil-gas mixture enters each separation gap 210 from above, it flows independently in each gap. The airflow in each gap does not cross, and the oil droplet aggregation and settling process in each separation gap 210 occurs independently, avoiding the influence of lateral airflow disturbance on oil droplet settling.

[0045] In further examples, such as Figure 3As shown, to ensure a more uniform flow distribution of the oil-gas mixture within each separation gap 210, adjacent oil-gas separators 200 are parallel to each other, and the horizontal spacing of the separation gaps 210 is consistent. Several oil-gas separators 200 are arranged at equal intervals, with equal spacing between adjacent separation gaps 210. The width 300 of each separation gap 210 is the same, resulting in a more uniform flow distribution of the oil-gas mixture as it enters each separation gap 210 from top to bottom. The airflow velocity and oil droplet collision probability within each gap are relatively consistent, leading to a relatively uniform separation effect in each separation gap 210.

[0046] In further examples, such as Figure 3 As shown, in the oil separator, the first oil separation space 111 and the second oil separation space 112 are connected in series through the bottom oil return space 131. The gaseous refrigerant first undergoes a first separation in the first oil separation space 111, and then undergoes a second separation in the second oil separation space 112. The flow rate of the medium flowing through the two spaces is the same. When oil-gas separators 200 are arranged in both the first oil separation space 111 and the second oil separation space 112, the first and second oil separation spaces are symmetrically arranged relative to the partition plate 500, and the spacing of the separation gaps 210 in the first oil separation space 111 is equal to the spacing of the separation gaps 210 in the second oil separation space 112. The total flow cross-sectional area of ​​the two spaces is the same. Under the condition of the same flow rate, the average airflow velocity in the two spaces is equal. If the airflow velocity is too high, the oil droplets will not have enough residence time within the separation gap 210, and will be carried out by the airflow before completing their lateral migration to the wall, resulting in a decrease in separation efficiency. If the velocity is too low, although the residence time is sufficient, the amount of gas processed per unit time will be reduced, and the overall processing capacity of the oil separator will be insufficient. Only when the airflow velocities in both spaces are within a reasonable range can both separation efficiency and processing capacity be guaranteed simultaneously.

[0047] It should be noted that "same flow rate" means that the volumetric flow rate or mass flow rate of the gaseous refrigerant flowing through the two spaces is the same. Because the temperature and density of the gaseous refrigerant decrease slightly as it flows from the first oil separator space through the return oil space into the second oil separator space, there may be a slight difference in volumetric flow rate. However, in practical engineering, this density change is very small, and the volumetric flow rate can be approximated as the same.

[0048] If the separation gaps 210 between the two spaces are not equal—for example, the gap in the first oil separation space 111 is narrower and the gap in the second oil separation space 112 is wider—the airflow velocity in the first oil separation space 111 will be higher and the airflow velocity in the second oil separation space 112 will be lower at the same flow rate. In this case, the oil droplet residence time in the first oil separation space 111 will be insufficient due to the excessively high flow velocity, and some oil droplets will enter the next stage without being fully separated. Although the flow velocity in the second oil separation space 112 is lower and the residence time is sufficient, the residual oil droplet content in the oil-gas mixture entering this space is already low, and the lower flow velocity fails to further exert its proper separation effect, resulting in the separation capacity of the second oil separation space 112 being idle. The mismatch in flow velocities between the two spaces limits the overall separation effect to the side with the higher flow velocity. When the separation gaps 210 between the two spaces are equal, the cross-sectional area is the same, and the flow rate is consistent, the airflow velocity in the two spaces is exactly the same, and the residence time and collision probability of oil droplets in the two spaces are equal. In the first separation stage, the first oil separation space 111 completes the separation of most oil droplets at a suitable rate; in the second separation stage, the second oil separation space 112 supplements the separation of residual oil droplets at the same suitable rate. The separation conditions of the two stages are matched with each other, the separation capacity is fully utilized, and the oil-gas mixture can be uniformly and fully processed in both separation stages, ensuring the consistency and stability of the overall separation effect.

[0049] In some examples, such as Figure 3 and Figure 4 As shown, regarding the specific cross-sectional shape of the oil-gas separator 200, the bends in the continuous bending structure can have an arc-shaped transition, making the cross-section of the oil-gas separator 200 wavy in the horizontal direction. The peaks and troughs of the wave are connected by smooth curves, and the flow direction of the oil-gas mixture changes relatively gently when flowing along the wavy sidewall, resulting in low flow resistance, which is suitable for high-velocity operating conditions.

[0050] In parallel examples, such as Figure 5 As shown, the bends in the continuous bending structure can also have acute angle transitions, making the cross-section of the oil-gas separator 200 serrated in the horizontal direction. The crests and troughs of the serrations are connected by straight segments, while the bends are sharp angles. When the oil-gas mixture flows through the serrated sidewalls, a sudden change in flow direction occurs at the sharp angles, enhancing the inertial collision effect of oil droplets at these angles and helping to improve the capture efficiency of smaller oil mist particles.

[0051] In further examples, such as Figure 1 and Figure 2As shown, to facilitate the manufacturing and assembly of the oil separator, the cylinder 100 has a split structure, including an oil separator cylinder 110, a top cover 120 covering the upper part of the oil separator cylinder 110, and a bottom cover 130 fastened to the lower part of the oil separator cylinder 110. An axially spaced partition plate 500 is provided inside the oil separator cylinder 110, dividing the internal space of the oil separator cylinder 110 into a first oil separation space 111 and a second oil separation space 112. The return oil space 131 is located inside the bottom cover 130, which is fastened to the lower part of the oil separator cylinder 110. The return oil space 131 communicates with the lower ends of the first oil separation space 111 and the second oil separation space 112, respectively. An inlet 121 and an outlet 122 are located on the top cover 120.

[0052] In a further example, regarding the manufacturing process, the oil separator cylinder 110, the separator plate 500, and the oil-gas separator component 200 can be integrally die-cast. Integral die-casting reduces the number of parts and assembly steps, improving production efficiency, while ensuring the connection strength and airtightness between the oil-gas separator component 200 and the inner wall of the cylinder 100 and the separator plate 500, preventing loosening or leakage at the joints due to long-term vibration. The oil separator cylinder 110, the separator plate 500, and the oil-gas separator component 200 can be made of aluminum. Aluminum has good thermal conductivity, which helps to transfer heat from the inside of the oil separator to the outside, and the die-casting process for aluminum is mature and suitable for mass production.

[0053] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. 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 protection of the claims of the present invention.

Claims

1. An oil separator for a refrigeration system, characterized in that, include: The cylinder (100) has a first oil separation space (111) and a second oil separation space (112) extending along the axial direction of the cylinder (100), and an oil return space (131) located below the first oil separation space (111) and communicating with the first oil separation space (111) and the second oil separation space (112) respectively. The cylinder (100) is provided with an inlet (121) communicating with the first oil separation space (111) and an outlet (122) communicating with the second oil separation space (112) and used to discharge gaseous refrigerant. A plurality of oil-gas separators (200) are arranged vertically and the plurality of oil-gas separators (200) are spaced apart in the first oil separation space (111). The cross-section of the oil-gas separator (200) is a continuous bending structure. A separation gap (210) is formed between two adjacent oil-gas separators (200) to allow the oil-gas mixture in the inlet (121) to pass through from top to bottom. The sidewall of the oil-gas separator (200) is used to adsorb oil droplets and guide the adsorbed and gathered oil droplets to the oil return space (131). The second oil separation space (112) is used to receive the gaseous refrigerant separated by the oil-gas separator (200) in the first oil separation space (111) and discharge it through the outlet (122).

2. The oil separator for a refrigeration system according to claim 1, characterized in that, A partition plate (500) is provided axially inside the cylinder (100). The partition plate (500) divides the inside of the cylinder (100) into a first oil separation space (111) and a second oil separation space (112) in the axial direction. The return oil space (131) is located below the first oil separation space (111) and the second oil separation space (112) and is used to receive oil droplets falling from the first oil separation space (111) and the second oil separation space (112). The second oil separation space (112) also has a number of oil-gas separators (200) arranged axially at intervals. The outlet (122) is located above the second oil separation space (112) so that the oil-gas mixture is discharged at the outlet (122) after being adsorbed and filtered by the oil-gas separators (200) in the second oil separation space (112).

3. An oil separator for a refrigeration system according to claim 2, characterized in that, One side edge of the oil-gas separator (200) is connected to the inner wall of the cylinder (100), and the other side edge is connected to the inner wall of the cylinder (100) or the partition plate (500). A separation gap (210) is formed between two adjacent oil-gas separators (200), and the two adjacent separation gaps (210) are isolated from each other.

4. An oil separator for a refrigeration system according to claim 3, characterized in that, Two adjacent oil-gas separators (200) are parallel to each other so that the width (300) of the separation gap (210) is the same, and several oil-gas separators (200) are arranged at equal intervals so that the distance between two adjacent separation gaps (210) is equal.

5. An oil separator for a refrigeration system according to claim 4, characterized in that, The first oil separation space (111) and the second oil separation space (112) are arranged symmetrically relative to the partition plate (500), and the spacing of the separation gaps (210) in the first oil separation space (111) is equal to the spacing of the separation gaps (210) in the second oil separation space (112), so that the flow rates of the first oil separation space (111) and the second oil separation space (112) are the same.

6. An oil separator for a refrigeration system according to claim 4, characterized in that, The bends of the continuous bending structure of the oil-gas separator (200) are arc-shaped, so that the cross-section of the oil-gas separator (200) in the horizontal direction is wavy.

7. An oil separator for a refrigeration system according to claim 4, characterized in that, The bends of the continuous bending structure of the oil-gas separator (200) have acute angle transitions, so that the cross-section of the oil-gas separator (200) in the horizontal direction is sawtooth-shaped.

8. An oil separator for a refrigeration system according to claim 2, characterized in that, The cylinder (100) includes an oil separator cylinder (110), a top cover (120) covering the upper part of the oil separator cylinder (110), and a bottom cover (130) fastened to the lower part of the oil separator cylinder (110); The separator plate (500) is disposed inside the oil separator cylinder (110); The oil return space (131) is located inside the bottom cover (130), and the inlet (121) and the outlet (122) are both located on the top cover (120).

9. An oil separator for a refrigeration system according to claim 8, characterized in that, The oil separator cylinder (110), the separator plate (500), and the oil-gas separator (200) are integrally die-cast.

10. An oil separator for a refrigeration system according to claim 4, characterized in that, The width (300) of the separation gap (210) is 16mm to 20mm.

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