Vertical oil separation device, separation method and refrigeration system

Abstract

The present application provides a vertical oil separation device, a separation method, and a refrigeration system, which belong to the technical field of refrigeration systems. The vertical oil separation device includes a shell, a plurality of storage tanks, a plurality of static pressure sensors, an oil storage chamber, a liquid inlet pipe, and a control module, wherein the static pressure sensor is associated with the liquid discharge switch valve of the storage tank, and the control module is electrically connected to the static pressure sensor, the liquid discharge switch valve, the oil discharge switch valve, the oil return switch valve, and the separation switch valve, respectively. When the static pressure detected by the static pressure sensor is greater than the static pressure preset value, the liquid discharge switch valve is controlled to open and close with a delay. The present application sets up multiple storage tanks, each of which is respectively provided with a static pressure sensor, and uses the static pressure sensor and the liquid discharge switch valve to continuously stratify and concentrate the refrigerant and lubricating oil, thereby increasing the concentration of the lubricating oil and ensuring that the refrigerant liquid discharged from each storage tank is free of lubricating oil, so that the liquid discharge and oil discharge processes operate stably.

Description

Technical Field

[0001] The present application belongs to the technical field of refrigeration systems, and specifically relates to a vertical oil separation device, a separation method, and a refrigeration system for separating refrigerant and lubricating oil. Background Art

[0002] Compressors in refrigeration systems often use lubricating oil for lubrication and sealing of their reciprocating mechanisms. At high temperatures, the lubricating oil exits the compressor as a mist mixture along with the refrigerant gas. Although compressors perform oil-gas separation in the exhaust, they cannot completely separate the lubricating oil from the gaseous mixture. Therefore, the refrigerant gas containing the lubricating oil mist condenses into liquid refrigerant and lubricating oil upon entering the condenser. If the lubricating oil enters the evaporator of the refrigeration system along with the refrigerant, it will be adsorbed on the heat transfer interface, reducing the evaporator's heat transfer efficiency. Furthermore, if the lubricating oil cannot be recovered, it will result in lubricating oil loss and increased lubricating oil consumption costs.

[0003] In the prior art, for ammonia removal refrigeration systems, since the density of lubricating oil is greater than that of ammonia liquid, the lubricating oil will sink to the bottom of the ammonia liquid. Therefore, the lubricating oil and ammonia liquid can be separated by periodically draining the lubricating oil at the bottom.

[0004] However, for refrigeration systems using chlorofluorocarbons or hydrochlorofluorocarbons refrigerants, the density of the lubricating oil used is usually smaller than that of the refrigerant liquid, that is, the refrigerant sinks to the bottom of the lubricating oil. Therefore, the lubricating oil cannot be directly discharged from the bottom like an ammonia removal refrigeration system. In addition, a layer of foam is likely to form on the interface between the chlorofluorocarbons or hydrochlorofluorocarbons refrigerant liquid and the lubricating oil. This layer of foam will float on the refrigerant and overflow to the bottom with the liquid, which is not conducive to the lubricating oil returning to the refrigeration compressor. If a liquid level detection system is installed, it will also interfere with the liquid level detection, which will make it difficult to separate the lubricating oil from the chlorofluorocarbons or hydrochlorofluorocarbons refrigerant liquid in the condenser.

[0005] Improving the separation efficiency of the oil separator is one way to prevent lubricating oil from entering the evaporator of the refrigeration system along with the refrigerant. However, no matter how high the oil separation efficiency is, it is impossible to reach 100%. Therefore, further separation of refrigerant liquid and lubricating oil is required in the refrigeration system. Summary of the Invention

[0006] In view of the problem that lubricating oil in chlorofluorocarbon or hydrochlorofluorocarbon refrigerant liquid is difficult to be effectively separated from the refrigerant in existing refrigeration systems, the present application aims to provide a vertical oil separation device, a separation method and a refrigeration system, which can effectively separate the lubricating oil from the refrigerant mixture by continuously separating the refrigerant and the lubricating oil into layers.

[0007] In a first aspect, the present application provides a vertical oil separation device, comprising:

[0008] A housing, comprising a vertical cylinder having a chamber and a top cover and a bottom cover located at the upper and lower ends of the vertical cylinder;

[0009] A plurality of storage tanks, the plurality of storage tanks being staggered from top to bottom on the inner side wall of the shell, a drainage pipe being provided at the bottom of each storage tank and flowing to the liquid outlet main pipe, and a drainage switch valve and a drainage check valve being provided in the outflow direction of each drainage pipe;

[0010] a plurality of static pressure sensors, each corresponding to each of the plurality of storage tanks, wherein the installation position of each static pressure sensor is at the same vertical height as the lowest position of the corresponding storage tank, and each static pressure sensor is associated with a drain switch valve of the corresponding storage tank;

[0011] An oil storage chamber is formed at the bottom of the chamber of the housing. An oil drain pipe communicating with the oil storage chamber is provided at the bottom of the housing. An oil drain switch valve is provided in the outflow direction of the oil drain pipe. One outlet of the oil drain switch valve is connected to the oil return switch valve, and the other outlet is provided with a separation switch valve and a separation check valve in sequence and communicates with the uppermost storage tank.

[0012] A liquid inlet pipe, which is used to deliver the mixed liquid to be separated into the uppermost storage tank;

[0013] A control module is electrically connected to each static pressure sensor, the liquid discharge switch valve, the oil discharge switch valve, the oil return switch valve, and the separation switch valve, and is used to:

[0014] The mixed liquid to be separated is sent into the uppermost storage tank;

[0015] When the static pressure detected by the static pressure sensor in each storage tank is greater than the static pressure preset value, the drain switch valve of the corresponding storage tank is controlled to open and close with a delay;

[0016] When the separation state of the oil storage chamber meets the preset oil return requirement, the oil drain valve switch and the oil return switch valve are controlled to open, and the separation switch valve is closed; otherwise, the oil drain switch valve and the separation switch valve are controlled to open, and the oil drain switch valve is closed.

[0017] In a possible embodiment, the static pressure preset values ​​of the plurality of static pressure sensors decrease sequentially from top to bottom.

[0018] In a possible embodiment, there are four storage tanks;

[0019] Correspondingly, the static pressure preset values ​​of the static pressure sensors are respectively as follows from top to bottom:

[0020] The static pressure sensor is installed horizontally to the upper edge of the tank to store the static pressure generated by 30% lubricating oil and 70% refrigerant;

[0021] The static pressure sensor is installed horizontally to the upper edge of the tank to store the static pressure generated by 50% lubricating oil and 50% refrigerant;

[0022] The static pressure sensor is installed horizontally to the upper edge of the tank to store the static pressure generated by 70% lubricating oil and 30% refrigerant;

[0023] The static pressure sensor is installed horizontally to the upper edge of the storage tank to store the static pressure generated by 85% lubricating oil and 15% refrigerant.

[0024] In a possible embodiment, it further includes:

[0025] An air outlet pipe is located just above the top cover.

[0026] In a possible embodiment, the upper portion of the oil storage chamber is separated by a concave closing cover, the bottom of the concave closing cover is connected to the oil storage chamber, and an oil drain check valve is provided at the connection point, and an air intake pipe is provided at the upper portion of the oil storage chamber.

[0027] In a possible embodiment, a guide plate is provided between the outlet of the liquid inlet pipe and the uppermost storage tank, for guiding the mixed liquid to be separated into the storage tank.

[0028] In a possible embodiment, a serrated notch is provided on the upper edge of the storage tank.

[0029] In a possible embodiment, an ultrasonic generator is provided on the side wall of the uppermost storage tank, and the ultrasonic generator can generate a planar sound beam in a horizontal direction.

[0030] In a possible embodiment, an ultrasonic generator is provided on the side wall of the uppermost storage tank, and the ultrasonic generator can generate a planar sound beam in a horizontal direction.

[0031] In a second aspect, the present application further provides a lubricating oil separation method, which is applied to the control module of the vertical oil separation device described in any embodiment of the first aspect, and the method comprises:

[0032] The mixed liquid to be separated is sent into the uppermost storage tank;

[0033] When the static pressure detected by the static pressure sensor in each storage tank is greater than the static pressure preset value, the drain switch valve of the corresponding storage tank is controlled to open and close with a delay;

[0034] When the separation state of the oil storage chamber meets the preset oil return requirement, the oil drain valve switch and the oil return switch valve are controlled to open, and the separation switch valve is closed; otherwise, the oil drain switch valve and the separation switch valve are controlled to open, and the oil drain switch valve is closed.

[0035] In a third aspect, the present application further provides a refrigeration system comprising the vertical oil separation device described in any embodiment of the first aspect.

[0036] The present application provides a vertical oil separation device, a separation method and a refrigeration system, wherein the vertical oil separation device increases the concentration of the lubricating oil by continuously stratifying and concentrating the refrigerant and the lubricating oil, thereby separating the refrigerant and the lubricating oil. At the same time, a static pressure sensor is linked to a drain switch valve to ensure that the refrigerant liquid discharged from each storage tank is free of lubricating oil. The static pressure sensor of each storage tank can ensure stable operation of draining and oil draining by setting a static pressure preset value. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0038] Figure 1 A schematic diagram of an application scenario of a refrigeration system for this application;

[0039] Figure 2 A schematic structural diagram of a vertical oil separation device provided in an embodiment of the present application;

[0040] Figure 3 A schematic diagram of the weir plate structure provided in an embodiment of the present application;

[0041] Figure 4 This is a schematic structural diagram of another vertical oil separation device provided in an embodiment of the present application.

[0042] The above drawings illustrate specific embodiments of the present application, which will be described in more detail below. These drawings and the textual description are not intended to limit the scope of the present application in any way, but rather to illustrate the concepts of the present application to those skilled in the art by reference to specific embodiments.

[0043] Description of reference numerals:

[0044] 101-compressor; 102-condenser; 103-throttling element; 104-evaporator; 201-housing; 202-first storage tank; 203-second storage tank; 204-third storage tank; 205-fourth storage tank; 206-drain pipe; 207-static pressure sensor; 208-oil storage chamber; 209-liquid inlet pipe; 210-return pipe; 211-sight glass; 212-guide plate; 213-exhaust pipe; 214-weir plate; 215-serrated notch; 216-concave closing cover; 217-inlet pipe. DETAILED DESCRIPTION

[0045] Exemplary embodiments will be described in detail herein, with examples illustrated in the accompanying drawings. In the following description, when referring to the drawings, identical numerals in different figures represent identical or similar elements unless otherwise indicated. The embodiments described in the following exemplary embodiments are not intended to represent all embodiments consistent with the present application. Rather, they are merely examples of apparatus and methods consistent with certain aspects of the present application, as detailed in the appended claims.

[0046] In the embodiments of the present application, words such as "first" and "second" are used to distinguish identical or similar items with substantially the same functions and effects. Those skilled in the art will understand that words such as "first" and "second" do not limit the quantity or execution order, and words such as "first" and "second" do not necessarily mean different.

[0047] It should be noted that, in the embodiments of the present application, words such as "exemplary" or "for example" are used to indicate examples, illustrations or explanations. Any embodiment or design described in this application as "exemplary" or "for example" should not be interpreted as being more preferred or advantageous than other embodiments or design. Specifically, the use of words such as "exemplary" or "for example" is intended to present related concepts in a concrete way. In the embodiments of the present application, "at least one" refers to one or more, and "a plurality" refers to two or more.

[0048] It should be noted that the “at…” in the embodiments of the present application can be the instant when a certain situation occurs, or it can be a period of time after the occurrence of a certain situation. The embodiments of the present application do not make specific limitations on this.

[0049] Figure 1 This is a schematic diagram of an application scenario of a refrigeration system in this application. In this application scenario, the refrigeration system mainly includes a compressor 101, a condenser 102, a throttling element 103, and an evaporator 104. The main functions of each part are as follows:

[0050] Compressor: The compressor 101 is the core component of the refrigeration system, compressing low-temperature, low-pressure gas into high-temperature, high-pressure gas. When the motor is powered, it drives the compressor, drawing in low-temperature, low-pressure refrigerant gas and compressing it into high-temperature, high-pressure gas.

[0051] Condenser: The condenser 102 is a heat output device that discharges the heat absorbed by the refrigerant in the evaporator and the heat converted by the power consumed by the compressor to the cooling medium (such as water or air), so that the refrigerant changes from gas to liquid.

[0052] Throttling element: The throttling element 103 throttles and reduces the pressure of the refrigerant, adjusts the refrigerant flow entering the evaporator, and throttles and reduces the pressure of the high-pressure and room-temperature refrigerant liquid when it flows through the expansion valve, turning it into low-temperature and low-pressure refrigerant wet vapor, which enters the evaporator to vaporize and absorb heat, thereby achieving the purpose of cooling and cooling.

[0053] Evaporator: The evaporator 104 is the device that outputs cooling capacity. The refrigerant in the evaporator absorbs heat from the object being cooled, thereby achieving the purpose of cooling. To ensure a stable and long-lasting evaporation process, the refrigeration compressor must continuously remove the evaporated gas to maintain a certain evaporation pressure.

[0054] exist Figure 1 In the refrigeration system shown, compressor 101 typically uses lubricating oil for lubrication and sealing of its reciprocating mechanism. At high temperatures, the lubricating oil exits compressor 101 as a mist mixture with the refrigerant gas. Although compressor 101 performs oil-gas separation in the exhaust, it cannot completely separate the lubricating oil from the gaseous mixture. Therefore, the refrigerant gas containing the misted lubricating oil condenses into liquid refrigerant and lubricating oil upon entering condenser 102. If the lubricating oil enters the evaporator 104 of the refrigeration system along with the refrigerant, it will be adsorbed on the heat transfer interface, reducing the heat transfer efficiency of evaporator 104. Furthermore, if the lubricating oil cannot be recovered, it will also result in lubricating oil loss, increasing lubricating oil consumption costs.

[0055] In the prior art, for ammonia removal refrigeration systems, since the density of the lubricating oil is greater than that of the ammonia liquid, the lubricating oil will sink to the bottom of the ammonia liquid. Therefore, the lubricating oil and the ammonia liquid can be separated by periodically draining the lubricating oil from the bottom. However, for refrigeration systems using chlorofluorocarbons or hydrochlorofluorocarbons (HCFCs) refrigerants, the density of the lubricating oil used is generally less than that of the refrigerant liquid, meaning that the refrigerant sinks to the bottom of the lubricating oil. Therefore, the lubricating oil cannot be directly drained from the bottom as in ammonia removal refrigeration systems. In addition, a layer of foam easily forms at the interface between the HCFC or hydrochlorofluorocarbon refrigerant liquid and the lubricating oil. This foam floats on the refrigerant and overflows to the bottom along with the liquid, hindering the lubricating oil from returning to the refrigeration compressor. If a liquid level detector is installed, this also interferes with the liquid level detector, making it difficult to separate the lubricating oil from the HCFC or hydrochlorofluorocarbon refrigerant liquid in the condenser 102.

[0056] In order to solve the above problems, the present application provides a vertical oil separation device, a separation method and a refrigeration system, wherein the vertical oil separation device increases the concentration of the lubricating oil by continuously stratifying and concentrating the refrigerant and the lubricating oil, thereby separating the refrigerant and the lubricating oil. At the same time, the static pressure sensor and the drain switch valve are linked to ensure that the refrigerant liquid discharged from each storage tank does not contain lubricating oil. The static pressure sensor of each storage tank can ensure the stable operation of drainage and oil drainage by setting a static pressure preset value.

[0057] Figure 2 This is a schematic diagram of the structure of a vertical oil separation device provided in the embodiment of the present application. Figure 2 As shown, the vertical oil separation device provided in this embodiment is applied to a high-pressure refrigeration system, and includes a shell 201, a plurality of storage tanks 202-205, a plurality of static pressure sensors 207, an oil storage cavity 208, a liquid inlet pipe 209 and a control module.

[0058] In the embodiment of the present application, the shell 201 includes a vertical cylinder having a chamber and a top cover and a bottom cover located at the upper and lower ends of the vertical cylinder.

[0059] In one specific embodiment, the vertical cylinder is cylindrical, with the top and bottom covers designed as elliptical structures. This improves the pressure-bearing capacity of the housing 201 compared to a hemispherical structure. Specifically, the top and bottom covers are elliptical structures with the major axis extending in the vertical direction. In this embodiment, the ratio of the vertical height to the diameter of the housing 201 is preferably 2:1 to 5:1.

[0060] In another specific embodiment, the cross-section of the vertical cylinder is elliptical. In this case, the long axes of the top cover and the bottom cover can make the top cover and the bottom cover an elliptical structure in both the horizontal and vertical directions.

[0061] In this embodiment, several storage tanks 202-205 are staggered from top to bottom on the inner sidewall of the housing 201. Each tank 202-205 has a drain pipe 206 at the bottom, which flows to the main liquid outlet pipe. Each drain pipe 206 is equipped with a drain valve and a drain check valve in the outflow direction. In this embodiment, a liquid inlet pipe 209 is located at the top of the housing 201 and is used to deliver the mixed liquid to be separated into the topmost storage tank.

[0062] Specifically, the embodiment of the present application is applied to a high-pressure system, in which case the liquid inlet pipe 209 is filled with a high-pressure mixed liquid containing lubricating oil and refrigerant.

[0063] In this embodiment, each storage tank 202-205 is surrounded by an arched bottom plate, the inner wall of the shell 201 and a weir plate 214, and the upper part of the storage tank is open, wherein the arched bottom plate is close to the inner wall of the shell 201, the arched bottom plates of two adjacent storage tanks are staggered by 180°, and the distance from each arched bottom plate to the inner wall of the distal shell 201 is B1.

[0064] like Figure 2 As shown, preferably, the arched bottom plate is inclined downward toward the inner wall of the shell 201, that is, the angle α between the arched bottom plate and the inner wall of the shell 201 is less than 90°, and more preferably, the angle α is 80° to 85°.

[0065] In one embodiment, the storage tanks are, from top to bottom, the first storage tank 202, the second storage tank 203, the third storage tank 204, and the fourth storage tank 205. The heights of the weir plates 214 of the four storage tanks 202 to 205 are H1, H2, H3, and H4, respectively. Preferably, the heights of the weir plates 214 of the four storage tanks decrease in descending order, i.e., H1>H2>H3>H4.

[0066] With respect to the above embodiment, the volumes of the four storage tanks 202 to 205 from top to bottom are V1, V2, V3, and V4 respectively. The volumes of the four storage tanks 202 to 205 from top to bottom preferably decrease in sequence, ie, V1>V2>V3>V4.

[0067] Sight glasses 211 are provided at the same height as the upper edge of the weir plate 214 of each storage tank, namely S1, S2, S3, and S4. From the sight glasses 211, it can be observed whether the liquid level of each independent storage tank exceeds the upper edge of the weir plate 214.

[0068] The vertical height difference between two adjacent storage tanks is H, which is preferably 50 mm to 100 mm. The size of H should be sufficient to allow the maximum amount of overflow liquid to pass smoothly.

[0069] Each tank has a corresponding discharge on / off valve (F1, F2, F3, and F4), and a corresponding discharge check valve (Z1, Z2, Z3, and Z4). The discharge on / off valve is installed at the lowest point of the tank, and the discharge check valve is to prevent the discharged refrigerant from flowing back into the tank.

[0070] In an embodiment of the present application, a plurality of static pressure sensors 207 correspond one-to-one to a plurality of storage tanks, and the vertical height between the installation position of each static pressure sensor 207 and the lowest position of the corresponding storage tank is the same, and the static pressure sensor 207 is associated with the drain switch valve of the corresponding storage tank.

[0071] With respect to the above embodiment, since the static pressure sensors 207 correspond one-to-one to the storage tanks, in this embodiment, static pressure sensors 207 are set on four storage tanks from top to bottom, corresponding to P1, P2, P3, and P4 respectively. Each static pressure sensor 207 has a corresponding static pressure preset value. When the static pressure sensor 207 detects that the liquid pressure in the storage tank reaches the static pressure preset value, it triggers the drain switch valve of the corresponding storage tank to open and delay closing.

[0072] Preferably, the static pressure preset values ​​corresponding to the static pressure sensors P1, P2, P3, and P4 decrease in sequence from top to bottom.

[0073] In the above embodiment, assuming that the density of the refrigerant is ω1 and the density of the lubricating oil is ω2, for any storage tank, the pressure value detected by the static pressure sensor 207 is:

[0074] W=ω1·g·H1+ω2·g·(H-H1)

[0075] In the above formula, g is the acceleration due to gravity, H is the total height of the liquid, H1 is the liquid height of the refrigerant, and therefore H-H1 is the liquid height of the lubricating oil.

[0076] After transformation, the pressure value detected by the static pressure sensor 207 is:

[0077] W=(ω1-ω2)·g·H1+ω2·g·H

[0078] Since the present application aims to solve the separation problem that the density of lubricating oil ω2 is less than the density of refrigerant ω1, ω1-ω2>0. It can be seen that the pressure value W detected by the static pressure sensor 207 is an increasing function of H1, that is, the greater the proportion of refrigerant, the greater W.

[0079] In the high-pressure system of the embodiment of the present application, the high-pressure mixture from the compressor 101 enters the shell 201 from the liquid inlet pipe 209. When the high-pressure mixture enters the oil separation device of the condensing device in the present application, it first enters the storage tank. The refrigerant is located at the bottom of the liquid and the lubricating oil is located at the top of the liquid. As the mixture increases, more and more refrigerant will be deposited in the bottom, and the lubricating oil in the upper part will overflow from the weir plate 214. Therefore, the proportion of refrigerant in the storage tank will gradually increase. As can be seen from the pressure value W calculated above, as the mixture continues to enter the storage tank, the greater the proportion of refrigerant, the pressure value W will gradually increase.

[0080] It is clear that the upper limit of the pressure value is when the tank is 100% refrigerant, and the lower limit is when the tank is 100% lubricant. Therefore, the static pressure preset value of the static pressure sensor 207 should be the ratio P of lubricant and the ratio 1-P of refrigerant.

[0081] As the refrigerant settles from top to bottom, the amount of refrigerant entering the next storage tank decreases. Therefore, the static pressure preset value of the static pressure sensor 207 should have a decreasing trend. This ensures that the pressure value detected by the static pressure sensor 207 reaches the static pressure preset value more easily as the storage tank moves downward, thereby triggering the drain switch valve to open.

[0082] In a specific embodiment, the static pressure preset values ​​of the four static pressure sensors 207 are respectively as follows from top to bottom:

[0083] Static pressure sensor P1: The static pressure preset value is the static pressure generated by the installation horizontal line of the static pressure sensor P1 to the upper edge of the storage tank storing 30% (volume ratio, the same below) lubricating oil and 70% (volume ratio, the same below) refrigerant.

[0084] Static pressure sensor P2: The static pressure preset value is the static pressure generated by the static pressure sensor P2 installation horizontal line to the upper edge of the storage tank storing 50% lubricating oil and 50% refrigerant.

[0085] Static pressure sensor P3: The static pressure preset value is the static pressure generated by the static pressure sensor P3 installation horizontal line to the upper edge of the storage tank storing 70% lubricating oil and 30% refrigerant.

[0086] Static pressure sensor P4: The static pressure preset value is the static pressure generated by the static pressure sensor P4 installation horizontal line to the upper edge of the storage tank storing 85% lubricating oil and 15% refrigerant.

[0087] From the setting of the above static pressure preset value, it can be seen that as the refrigerant proportion decreases, the corresponding static pressure preset value gradually decreases, which is consistent with the above analysis of the relationship between the static pressure preset value and the refrigerant proportion.

[0088] It is understandable that, for other numbers of static pressure sensors 207 , the static pressure preset values ​​of the static pressure sensors 207 can be adjusted according to specific circumstances.

[0089] When setting the static pressure preset value, the static pressure preset value of the static pressure sensor 207 = density close to the refrigerant saturation temperature × gravity acceleration × (vertical height difference from the installation horizontal line of the static pressure sensor 207 to the upper edge of the corresponding storage tank weir plate 214 - adjustment height)

[0090] It should be further explained that the static pressure preset value for each static pressure sensor 207 is only a relative value based on the same baseline, not the actual static pressure. Therefore, the density of a liquid (e.g., refrigerant) does not necessarily correspond to its actual saturation temperature; it can be a value close to it. This is because the refrigerant's saturation temperature fluctuates during actual operation of the refrigeration system and is not a fixed value. In principle, the static pressure preset value for each static pressure sensor 207 should be less than the actual static pressure value at that static pressure sensor 207. This is why the height adjustment height is subtracted when determining the static pressure preset value for each static pressure sensor 207, and this adjustment height value must be a positive number.

[0091] In this embodiment, an oil reservoir 208 is formed at the bottom of the housing 201. A drain pipe is provided at the bottom of the housing 201, connecting to the reservoir 208. An oil drain valve F5 is installed in the outlet of the drain pipe. One outlet of the drain valve F5 is connected to the oil return valve F6. Another outlet is connected to a separation valve F7 and a separation check valve Z5, which are then connected to the uppermost reservoir. Preferably, a sight glass S5 is provided on the housing 201 corresponding to the oil reservoir 208.

[0092] In the above embodiment, when the pressure value detected by the static pressure sensor 207 in the storage tank reaches the preset static pressure value, the drain switch valve is triggered to open, allowing the refrigerant at the bottom to be discharged into the liquid outlet manifold. After the refrigerant is separated, more and more lubricating oil will enter the lower storage tank. When the lubricating oil overflows into the bottom oil storage chamber 208, the lubricating oil can be discharged by opening the oil drain switch valve F5. Because the lubricating oil still contains a certain amount of refrigerant, when the lubricating oil quality does not meet the requirements, it is necessary to allow the discharged lubricating oil to continue to flow back to the top first storage tank 202 through the return pipe 210. It should be noted that the entrance of the return pipe 210 into the first storage tank 202 is preferably located above the upper edge of the weir plate 214.

[0093] In an embodiment of the present application, the control module is electrically connected to the static pressure sensors P1, P2, P3, P4, the liquid discharge switch valves F1, F2, F3, F4, the oil discharge switch valve F5, the oil return switch valve F6 and the separation switch valve F7 respectively.

[0094] The control module is used to implement the following control processes:

[0095] S100: The mixed liquid to be separated is sent to the uppermost storage tank.

[0096] In the high-pressure system, the mixed liquid to be separated comes from a mixture of refrigerant and lubricant discharged from the compressor 101 , wherein the refrigerant is a chlorofluorocarbon or hydrochlorofluorocarbon refrigerant having a density greater than that of the lubricant.

[0097] S200: When the static pressure detected by the static pressure sensor 207 in each storage tank is greater than the static pressure preset value, the drain switch valve of the corresponding storage tank is controlled to open and close with a delay.

[0098] When the static pressure detected by the static pressure sensor 207 is greater than the static pressure preset value, it means that a sufficient proportion of refrigerant has been stored in the storage tank and the drain switch valve needs to be opened to discharge it; and delayed closing ensures that the refrigerant can be continuously discharged for a certain period of time.

[0099] S300: When the separation state of the oil storage chamber 208 meets the preset oil return requirement, the oil drain valve switch and the oil return switch valve are controlled to open, and the separation switch valve is closed; otherwise, the oil drain switch valve and the separation switch valve are controlled to open, and the oil drain switch valve is closed.

[0100] The separation state of the oil storage chamber 208 can be observed through the sight glass S5, and can also be determined based on the depth and pressure value of the oil storage chamber 208.

[0101] Continue reading Figure 2 As shown, in the embodiment of the present application, the vertical oil separation device can also be improved as follows.

[0102] In a specific embodiment, the inlet of the liquid inlet pipe 209 bends downward after entering the shell 201, but the vertical port is closed. Instead, the outlet of the liquid inlet pipe 209 is set to face the inner wall of the shell 201, which can reduce the impact of the liquid.

[0103] Specifically, an arched guide plate 212 is provided between the end of the liquid inlet pipe 209 and the first storage tank 202 to guide the mixed liquid to be separated into the storage tank. One side of the guide plate 212 is in close contact with the inner wall of the housing 201. The distance H2 between the guide plate 212 and the end of the liquid inlet pipe 209 is preferably 3.5°. The angle β between the guide plate 212 and the inner wall of the housing 201 is preferably greater than 90°, and more preferably, the angle β is between 95° and 100°. The width of the guide plate 212 exceeds the distance B at the lower end of the liquid inlet pipe 209 by 50% of the diameter of the liquid inlet pipe 209.

[0104] In another specific embodiment, Figure 3 The schematic diagram of the weir plate structure provided in the embodiment of this application is as follows: Figure 3 As shown, the upper edge of the storage tank is provided with a serrated notch 215. When foamy refrigerant overflows from the top to the bottom of the storage tank, the serrated notch 215 can defoam the refrigerant. The included angle γ of the serrated notch 215 is preferably 60° to 120°, more preferably γ = 90°. The height h of the serrated notch 215 is preferably 20 mm to 30 mm.

[0105] In another embodiment, see Figure 2 An ultrasonic generator is installed on the side of the weir plate 214 of the first storage tank 202, away from the inner wall of the housing 201. This ultrasonic generator generates a horizontal, planar acoustic beam that covers the entire liquid surface of the first storage tank 202. The ultrasonic generator is installed 30 to 50 mm below the upper edge of the weir plate 214. The planar acoustic beam generated by the ultrasonic generator is capable of breaking up bubbles formed on the refrigerant liquid surface.

[0106] Below Figure 2 The separation process of the vertical oil separation device of the embodiment shown is described below:

[0107] After entering the shell 201 through the liquid inlet pipe 209, the high-pressure mixed liquid is sprayed toward the inner wall of the shell 201. Due to the effects of collision, change in flow direction, and reduction in flow velocity, the refrigerant liquid and lubricating oil droplets are separated from the refrigerant gas. Then, under the guidance of the guide plate 212, they fall into the first storage tank 202. The liquid level in the first storage tank 202 gradually rises. When the volume ratio of refrigerant to lubricating oil reaches 7:3, the static pressure sensor P1 sends a signal to the drain switch valve F1, which opens and closes with a delay. The refrigerant at the bottom of the first storage tank 202 flows to the liquid outlet manifold through the drain switch valve F1 and the drain check valve Z1. When the static pressure sensor P1 detects that the static pressure is less than the corresponding preset static pressure value, the drain switch valve F1 stops opening, and the liquid level continues to rise. When the liquid level exceeds the upper edge of the weir plate 214 of the first storage tank 202, the lubricating oil or the miscible mixture of lubricating oil and refrigerant in the upper portion overflows into the second storage tank 203.

[0108] After entering the second storage tank 203, the liquid level gradually rises. When the volume ratio of refrigerant to lubricating oil reaches 5:5, the static pressure sensor P2 sends a signal to the discharge switch valve F2, and the discharge switch valve F2 opens and closes with a delay. The refrigerant at the bottom of the second storage tank 203 flows to the liquid outlet main pipe through the discharge switch valve F2 and the discharge check valve Z2; when the static pressure sensor P2 detects that the static pressure is less than the corresponding static pressure preset value, the discharge switch valve F2 no longer opens, and the liquid level continues to rise. When the liquid level is higher than the upper edge of the weir plate 214 at the second storage tank 203, the lubricating oil or the mixed liquid of lubricating oil and refrigerant in the upper part overflows into the storage tank V3.

[0109] After entering the third storage tank 204, the liquid level gradually rises. When the volume ratio of refrigerant and lubricating oil reaches 3:7, the static pressure sensor P3 sends a signal to the discharge switch valve F3, the discharge switch valve F3 opens and closes with a delay, and the refrigerant at the bottom of the third storage tank 204 flows to the liquid outlet main pipe through the discharge switch valve F3 and the discharge check valve Z3; when the static pressure sensor P3 detects that the static pressure is less than the corresponding static pressure preset value, the discharge switch valve F3 no longer opens, and the liquid level continues to rise. When the liquid level is higher than the upper edge of the weir plate 214 at the third storage tank 204, the lubricating oil or the mixed liquid of lubricating oil and refrigerant in the upper part overflows into the fourth storage tank 205.

[0110] After entering the fourth storage tank 205, the liquid level gradually rises. When the volume ratio of refrigerant to lubricating oil reaches 1.5:8.5, the static pressure sensor P4 sends a signal to the switch valve F4, the discharge switch valve F4 opens and closes with a delay, and the refrigerant at the bottom of the fourth storage tank 205 flows to the liquid outlet main pipe through the discharge switch valve F4 and the discharge check valve Z4; when the static pressure sensor P2 detects that the static pressure is less than the corresponding static pressure preset value, the discharge switch valve F4 no longer opens, and the liquid level continues to rise. When the liquid level is higher than the upper edge of the weir plate 214 at the fourth storage tank 205, the lubricating oil or the mixed liquid of lubricating oil and refrigerant in the upper part overflows into the bottom oil storage chamber 208.

[0111] After entering the oil storage chamber 208, the oil drain switch valve F5 and the oil drain switch valve F6 can be opened to discharge the liquid in the oil storage chamber 208 when the separation switch valve F7 is closed according to the oil return operation requirements. Alternatively, the oil drain switch valve F5 and the separation switch valve F7 can be opened when the return oil switch valve F6 is closed according to the separation conditions of the refrigerant and the lubricating oil to send the liquid in the oil storage chamber 208 back to the first storage tank 202 for further separation.

[0112] The liquid discharge check valves Z1, Z2, Z3, and Z4 are used to prevent the refrigerant liquid from flowing back during the liquid discharge operation. The separation check valve Z5 is used to prevent the gas in the upper part of the shell 201 from entering the oil discharge pipe through the return pipe when the oil discharge switching valve F5 and the separation switching valve F7 are opened.

[0113] Figure 4 This is another schematic diagram of the structure of a vertical oil separation device provided in the embodiment of the present application. Figure 4 As shown, the vertical oil separation device provided in this embodiment is Figure 2 The embodiment shown is modified so as to be applied to a low-pressure system.

[0114] The vertical oil separation device provided in this embodiment is compared with Figure 2 The differences between the shown embodiments are:

[0115] The shell also includes an air outlet pipe 213 , which is located directly above the top cover. The air outlet pipe 213 is configured to discharge gas generated in the shell 201 in a low-pressure environment to the compressor 101 .

[0116] In addition, since there may be insufficient pressure when draining oil in a low-pressure system, in order to discharge the lubricating oil in the oil storage chamber 208 to the outside, the embodiment of the present application provides a concave closing cover 216 on the upper part of the oil storage chamber 208, thereby separating the oil storage chamber 208 from other chambers of the shell 201. The bottom of the concave closing cover 216 is connected to the oil storage chamber 208, and an oil discharge check valve Z6 is provided at the connection point. An air inlet pipe 217 is provided on the upper part of the oil storage chamber 208 for discharging the lubricating oil in the oil storage chamber 208.

[0117] Below Figure 4The separation process of the vertical oil separation device of the embodiment shown is described below:

[0118] After the mixed liquid enters the shell 201 from the liquid inlet pipe 209, it is sprayed toward the inner wall of the shell 201. Under the action of collision, change of flow direction and reduction of flow velocity, the refrigerant liquid and lubricating oil droplets are separated from the refrigerant gas. The refrigerant gas is sucked away by the compressor from one end of the outlet pipe 213. In the process of the refrigerant gas entering the outlet pipe 213, deflection baffles, mist collectors and other elements that increase the gas-liquid separation efficiency can be added to the flow route as needed. After the refrigerant liquid and lubricating oil droplets are separated, they fall into the first storage tank 202 under the guiding action of the guide plate 212, and the liquid level of the first storage tank 202 gradually rises. When the volume ratio of refrigerant and lubricating oil reaches 7:3, the static pressure sensor P1 sends a signal to the drain switch valve F1, the drain switch valve F1 opens and closes with a delay, and the refrigerant at the bottom of the first storage tank 202 flows to the liquid outlet main pipe through the drain switch valve F1 and the drain check valve Z1; when the static pressure sensor P1 detects that the static pressure is less than the corresponding static pressure preset value, the drain switch valve F1 no longer opens, and the liquid level continues to rise. When the liquid level is higher than the upper edge of the weir plate 214 of the first storage tank 202, the lubricating oil or the mixed liquid of lubricating oil and refrigerant in the upper part overflows into the second storage tank 203.

[0119] After entering the second storage tank 203, the liquid level gradually rises. When the volume ratio of refrigerant to lubricating oil reaches 5:5, the static pressure sensor P2 sends a signal to the discharge switch valve F2, and the discharge switch valve F2 opens and closes with a delay. The refrigerant at the bottom of the second storage tank 203 flows to the liquid outlet main pipe through the discharge switch valve F2 and the discharge check valve Z2; when the static pressure sensor P2 detects that the static pressure is less than the corresponding static pressure preset value, the discharge switch valve F2 no longer opens, and the liquid level continues to rise. When the liquid level is higher than the upper edge of the weir plate 214 at the second storage tank 203, the lubricating oil or the mixed liquid of lubricating oil and refrigerant in the upper part overflows into the storage tank V3.

[0120] After entering the third storage tank 204, the liquid level gradually rises. When the volume ratio of refrigerant and lubricating oil reaches 3:7, the static pressure sensor P3 sends a signal to the discharge switch valve F3, the discharge switch valve F3 opens and closes with a delay, and the refrigerant at the bottom of the third storage tank 204 flows to the liquid outlet main pipe through the discharge switch valve F3 and the discharge check valve Z3; when the static pressure sensor P3 detects that the static pressure is less than the corresponding static pressure preset value, the discharge switch valve F3 no longer opens, and the liquid level continues to rise. When the liquid level is higher than the upper edge of the weir plate 214 at the third storage tank 204, the lubricating oil or the mixed liquid of lubricating oil and refrigerant in the upper part overflows into the fourth storage tank 205.

[0121] After entering the fourth storage tank 205, the liquid level gradually rises. When the volume ratio of refrigerant to lubricating oil reaches 1.5:8.5, the static pressure sensor P4 sends a signal to the switch valve F4, the discharge switch valve F4 opens and closes with a delay, and the refrigerant at the bottom of the fourth storage tank 205 flows to the liquid outlet main pipe through the discharge switch valve F4 and the discharge check valve Z4; when the static pressure sensor P3 detects that the static pressure is less than the corresponding static pressure preset value, the discharge switch valve F4 no longer opens, and the liquid level continues to rise. When the liquid level is higher than the upper edge of the weir plate 214 of the fourth storage tank 205, the lubricating oil or the mixed liquid of lubricating oil and refrigerant in the upper part overflows to the lower concave closing cover 216 for collection, and falls into the bottom oil storage chamber 208 through the oil discharge check valve Z6 at the lower part of the concave closing cover 216.

[0122] After entering the oil reservoir 208, the liquid can be drained from the oil reservoir 208 by opening the oil drain valves F5 and F6 while closing the separation valve F7, depending on the oil return operation requirements. Alternatively, the liquid can be returned to the first storage tank 202 for further separation by opening the oil drain valves F5 and F7 while closing the return valve F6, depending on the separation conditions of the refrigerant and lubricating oil. When the refrigerant temperature is low, the lubricating oil has a high viscosity, making oil drainage difficult. In this case, high-pressure gas can be introduced into the oil reservoir 208 through the air inlet pipe 217 to force the lubricating oil out of the oil reservoir 208.

[0123] In the embodiment of the present application, if the viscosity of the lubricating oil is high, re-separation may not be performed.

[0124] The liquid discharge check valves Z1, Z2, Z3, and Z4 are used to prevent the refrigerant liquid from flowing back during the liquid discharge operation. The oil discharge check valve Z6 is used to prevent the high-pressure gas from pressing the lubricating oil in the oil storage chamber 208 back into the upper chamber of the concave sealing cover when the high-pressure gas is used to discharge the oil.

[0125] The present application also provides a lubricating oil separation method, which is applied to the control module of the vertical oil separation device in the above embodiment. The method includes:

[0126] The mixed liquid to be separated is sent into the uppermost storage tank; when the static pressure detected by the static pressure sensor in each storage tank is greater than the static pressure preset value, the drain switch valve of the corresponding storage tank is controlled to open and close with a delay; when the separation state of the oil storage chamber meets the preset oil return requirement, the drain valve switch and the return oil switch valve are controlled to open, and the separation switch valve is closed; otherwise, the drain switch valve and the separation switch valve are controlled to open, and the drain switch valve is closed.

[0127] An embodiment of the present application further provides a refrigeration system applied to a high-pressure system, in which a mixed liquid containing refrigerant and lubricating oil is input into a liquid inlet pipe of a vertical oil separation device.

[0128] An embodiment of the present application also provides a refrigeration system for a low-pressure system, in which a liquid mixture containing refrigerant and lubricating oil is input into a liquid inlet pipe of a vertical oil separation device, a high-pressure gas is input into an air inlet pipe, and an air outlet pipe is connected to a compressor.

[0129] The above two refrigeration systems can effectively separate the mixed liquid containing refrigerant and lubricating oil entering from the liquid inlet pipe, which not only allows the lubricating oil and refrigerant to be recycled, but also ensures the heat transfer efficiency of the refrigeration system.

[0130] Obviously, those skilled in the art may make various changes and modifications to this application without departing from the spirit and scope of this application. Thus, if these modifications and variations of this application fall within the scope of the claims of this application and their equivalents, this application is intended to include these modifications and variations.

Claims

1. A vertical oil separation device, characterized in that: include: A housing, comprising a vertical cylinder having a chamber and a top cover and a bottom cover located at the upper and lower ends of the vertical cylinder; A plurality of storage tanks, the plurality of storage tanks being staggered from top to bottom on the inner side wall of the shell, a drainage pipe being provided at the bottom of each storage tank and flowing to the liquid outlet main pipe, and a drainage switch valve and a drainage check valve being provided in the outflow direction of each drainage pipe; a plurality of static pressure sensors, each corresponding to each of the plurality of storage tanks, wherein the installation position of each static pressure sensor is at the same vertical height as the lowest position of the corresponding storage tank, and each static pressure sensor is associated with a drain switch valve of the corresponding storage tank; An oil storage chamber is formed at the bottom of the chamber of the housing. An oil drain pipe communicating with the oil storage chamber is provided at the bottom of the housing. An oil drain switch valve is provided in the outflow direction of the oil drain pipe. One outlet of the oil drain switch valve is connected to the oil return switch valve, and the other outlet is provided with a separation switch valve and a separation check valve in sequence and communicates with the uppermost storage tank. A liquid inlet pipe, which is used to deliver the mixed liquid to be separated into the uppermost storage tank; A control module is electrically connected to each static pressure sensor, the liquid discharge switch valve, the oil discharge switch valve, the oil return switch valve, and the separation switch valve, and is used to: The mixed liquid to be separated is sent into the uppermost storage tank; When the static pressure detected by the static pressure sensor in each storage tank is greater than the static pressure preset value, the drain switch valve of the corresponding storage tank is controlled to open and close with a delay; When the separation state of the oil storage chamber meets the preset oil return requirement, the oil drain valve switch and the oil return switch valve are controlled to open, and the separation switch valve is closed; otherwise, the oil drain switch valve and the separation switch valve are controlled to open, and the oil drain switch valve is closed.

2. The vertical oil separation device according to claim 1, characterized in that: The static pressure preset values ​​of the static pressure sensors decrease in sequence from top to bottom.

3. The vertical oil separation device according to claim 2, characterized in that: There are four storage tanks; Correspondingly, the static pressure preset values ​​of the four static pressure sensors are from top to bottom: The static pressure sensor is installed horizontally to the upper edge of the tank to store the static pressure generated by 30% lubricating oil and 70% refrigerant; The static pressure sensor is installed horizontally to the upper edge of the tank to store the static pressure generated by 50% lubricating oil and 50% refrigerant; The static pressure sensor is installed horizontally to the upper edge of the tank to store the static pressure generated by 70% lubricating oil and 30% refrigerant; The static pressure sensor is installed horizontally to the upper edge of the storage tank to store the static pressure generated by 85% lubricating oil and 15% refrigerant.

4. The vertical oil separation device according to claim 1, characterized in that: Also includes: An air outlet pipe is located just above the top cover.

5. The vertical oil separation device according to claim 4, characterized in that: The upper portion of the oil storage chamber is separated by a concave closing cover, the bottom of the concave closing cover is connected to the oil storage chamber, and an oil discharge check valve is provided at the connection point, and an air inlet pipe is provided at the upper portion of the oil storage chamber.

6. The vertical oil separation device according to any one of claims 1 to 5, characterized in that: A guide plate is provided between the outlet of the liquid inlet pipe and the uppermost storage tank, for guiding the mixed liquid to be separated into the storage tank.

7. The vertical oil separation device according to claim 6, characterized in that: The upper edge of the storage tank is provided with a serrated notch.

8. The vertical oil separation device according to claim 6, characterized in that: An ultrasonic generator is provided on the side wall of the uppermost storage tank, and the ultrasonic generator can generate a planar sound beam in a horizontal direction.

9. A lubricating oil separation method, characterized in that: A control module applied to the vertical oil separation device according to any one of claims 1 to 8, wherein the method comprises: The mixed liquid to be separated is sent into the uppermost storage tank; When the static pressure detected by the static pressure sensor in each storage tank is greater than the static pressure preset value, the drain switch valve of the corresponding storage tank is controlled to open and close with a delay; When the separation state of the oil storage chamber meets the preset oil return requirement, the oil drain valve switch and the oil return switch valve are controlled to open, and the separation switch valve is closed; otherwise, the oil drain switch valve and the separation switch valve are controlled to open, and the oil drain switch valve is closed.

10. A refrigeration system, characterized in that: It comprises the vertical oil separation device according to any one of claims 1 to 9.

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