Vertical oil separation device, separation method and refrigeration system

Abstract

The invention provides a vertical oil separation device, a separation method and a refrigerating system, and belongs to the technical field of refrigerating systems.The vertical oil separation device comprises a shell, a plurality of storage tanks, a plurality of static pressure sensors, an oil storage cavity, a liquid inlet pipe and a control module, the control module is electrically connected with the static pressure sensor, the liquid drainage switch valve, the oil drainage switch valve, the oil return switch valve and the separation switch valve, and when the static pressure detected by the static pressure sensor is larger than a static pressure preset value, the liquid drainage switch valve is controlled to be opened and closed in a delayed mode. The multiple storage tanks are arranged, each storage tank is provided with the corresponding static pressure sensor, the static pressure sensors are used for being associated with the liquid drainage switch valves, and refrigerants and lubricating oil are continuously layered and concentrated, so that the concentration of the lubricating oil is improved, it is ensured that refrigerant liquid drained out of each storage tank does not contain the lubricating oil, and the liquid drainage and oil drainage processes are stably operated.

Description

Technical Field

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

[0002] The compressors in the refrigeration system mostly use lubricating oil for reciprocating mechanism lubrication and sealing. At high temperature, the lubricating oil is discharged from the compressor in the form of oil mist along with the refrigerant gas to form a gaseous mixture. Although the compressor performs oil and gas separation in the exhaust, it is impossible to separate 100% of the lubricating oil in the gaseous mixture. Therefore, the refrigerant gas containing mist lubricating oil will be condensed into liquid refrigerant and lubricating oil after entering the condenser. If the lubricating oil enters the evaporator of the refrigeration system together with the refrigerant and is adsorbed on the heat transfer interface, the heat transfer efficiency of the evaporator will be reduced. In addition, if the lubricating oil cannot be recovered, it will also cause the loss of lubricating oil and increase the cost of lubricating oil consumption.

[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 the ammonia liquid can be separated by periodically discharging 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 separation device is a way to prevent the 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, it is necessary to further separate the refrigerant liquid and the lubricating oil in the refrigeration system. Summary of the invention

[0006] In view of the problem that in existing refrigeration systems, the lubricating oil in chlorofluorocarbon or hydrochlorofluorocarbon refrigerant liquids is difficult to be effectively separated from the refrigerant, 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 stratifying the refrigerant and the lubricating oil.

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

[0008] A shell, the shell 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, wherein the plurality of storage tanks are staggered from top to bottom on the inner side wall of the shell, a liquid discharge pipe flowing to the liquid outlet main pipe is provided at the bottom of each storage tank, and a liquid discharge switch valve and a liquid discharge check valve are provided in the outflow direction of each liquid discharge pipe in sequence;

[0010] A plurality of static pressure sensors, the plurality of static pressure sensors corresponding to the plurality of storage tanks one by one, and the vertical height between the installation position of each static pressure sensor and the lowest position of the corresponding storage tank is the same, and the static pressure sensor is associated with the drain switch valve of the corresponding storage tank;

[0011] An oil storage chamber, the oil storage chamber is formed at the bottom of the chamber of the shell, an oil drain pipe connected to the oil storage chamber is provided at the bottom of the shell, 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 connected to 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, wherein the 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 the control module 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 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 discharge 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 sawtooth 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 a 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, and at the same time uses a static pressure sensor and a drain switch valve 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 draining and 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 diagram of the structure 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 the embodiment of the present application;

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

[0042] The above drawings have shown clear embodiments of the present application, which will be described in more detail later. These drawings and text descriptions are not intended to limit the scope of the present application in any way, but to illustrate the concept of the present application to those skilled in the art by referring 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 closure cover; 217-inlet pipe. DETAILED DESCRIPTION

[0045] Exemplary embodiments will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, the same numbers in different drawings represent the same or similar elements unless otherwise indicated. The implementations described in the following exemplary embodiments do not represent all implementations consistent with the present application. Instead, they are merely examples of devices and methods consistent with some 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 the same or similar items with substantially the same functions and effects. Those skilled in the art can understand that words such as "first" and "second" do not limit the quantity and execution order, and words such as "first" and "second" do not necessarily limit the difference.

[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 descriptions. Any embodiment or design described as "exemplary" or "for example" in the present application should not be interpreted as being more preferred or more advantageous than other embodiments or designs. 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 "more than one" refers to two or more.

[0048] It should be noted that the “at…” in the embodiments of the present application may be the instant when a certain situation occurs, or may be a period of time after the occurrence of a certain situation, and the embodiments of the present application do not specifically limit this.

[0049] Figure 1 This is a schematic diagram of an application scenario of a refrigeration system of the present 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. Its function is to compress low-temperature and low-pressure gas into high-temperature and high-pressure gas. When the motor is powered on, it drives the compression part to work, sucking in low-temperature and low-pressure refrigerant gas, which is compressed into high-temperature and 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 work 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 has a throttling and pressure-reducing effect on the refrigerant, and adjusts the refrigerant flow entering the evaporator, so that the high-pressure and room-temperature refrigerant liquid is throttled and pressure-reduced when flowing through the expansion valve, and becomes low-temperature and low-pressure refrigerant wet vapor, which enters the evaporator to vaporize and absorb heat, thereby achieving the purpose of refrigeration and cooling.

[0053] Evaporator: The evaporator 104 is a device that outputs cooling capacity. The refrigerant absorbs the heat of the object being cooled in the evaporator, thereby achieving the purpose of cooling. In order to ensure that the evaporation process can be carried out stably and permanently, the evaporated gas must be continuously extracted by the refrigeration compressor to maintain a certain evaporation pressure.

[0054] exist Figure 1 In the refrigeration system shown, the compressor 101 mostly uses lubricating oil for lubrication and sealing of the reciprocating mechanism. At high temperature, the lubricating oil is discharged from the compressor 101 in the form of oil mist together with the refrigerant gas to form a gaseous mixture. Although the compressor 101 performs oil and gas separation in the exhaust, it is impossible to separate 100% of the lubricating oil in the gaseous mixture. Therefore, the refrigerant gas containing mist lubricating oil will be condensed into liquid refrigerant and lubricating oil after entering the condenser 102. If the lubricating oil enters the evaporator 104 of the refrigeration system together with the refrigerant and is adsorbed on the heat transfer interface, the heat transfer efficiency of the evaporator 104 will be reduced. In addition, if the lubricating oil cannot be recovered, it will also cause the loss of lubricating oil and increase the cost of consuming lubricating oil.

[0055] 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, so the lubricating oil and ammonia liquid can be separated by periodically discharging the lubricating oil at the bottom. 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, so the lubricating oil cannot be directly discharged from the bottom like in ammonia removal refrigeration systems, and a layer of foam is easily generated 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 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 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, and at the same time uses a static pressure sensor and a drain switch valve 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 draining and draining 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 an 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 housing 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 a specific embodiment, the vertical cylinder is cylindrical, and the top cover and the bottom cover are designed as an elliptical structure, which can improve the pressure bearing capacity of the shell 201 compared with the hemispherical structure. Specifically, the top cover and the bottom cover are elliptical structures with the long axis extending in the vertical direction. In this embodiment, the ratio of the height to the diameter of the shell 201 in the vertical direction 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 the embodiment of the present application, a plurality of storage tanks 202-205 are staggered from top to bottom on the inner wall of the housing 201, and a liquid discharge pipe 206 flowing to the liquid outlet main pipe is provided at the bottom of each storage tank 202-205, and a liquid discharge switch valve and a liquid discharge check valve are provided in sequence in the outflow direction of each liquid discharge pipe 206. In this embodiment, the liquid inlet pipe 209 is located at the upper part of the housing 201, and is used to send the mixed liquid to be separated into the uppermost storage tank.

[0062] Specifically, the embodiment of the present application is applied to a high-pressure system, and at this time, a high-pressure mixed liquid containing lubricating oil and refrigerant enters the liquid inlet pipe 209.

[0063] In this embodiment, each storage tank 202-205 is surrounded by an arched bottom plate, an inner wall of a shell 201 and a weir plate 214, and the top 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 a specific embodiment, the storage tanks are respectively the first storage tank 202, the second storage tank 203, the third storage tank 204 and the fourth storage tank 205 from top to bottom, and the heights of the weir plates 214 of the four storage tanks 202 to 205 from top to bottom are respectively H1, H2, H3, and H4. Preferably, the heights of the weir plates 214 of the four storage tanks decrease in sequence from top to bottom, that is, 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] Liquid sight glasses 211 are provided at equal height positions on the upper edge of the weir plate 214 of each storage tank, namely S1, S2, S3, and S4. From the liquid 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, and H 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] The drain switch valves corresponding to each storage tank are F1, F2, F3, and F4, and the drain check valves corresponding to each storage tank are Z1, Z2, Z3, and Z4. The drain switch valve is installed at the lowest point of the storage tank, and the drain check valve is to prevent the discharged refrigerant from flowing back into the storage 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-mentioned embodiment, since the static pressure sensor 207 corresponds one-to-one with the storage tank, in this embodiment, four storage tanks are provided with static pressure sensors 207 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, the drain switch valve of the corresponding storage tank is triggered to open and close with a delayed delay.

[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 at the bottom, and the lubricating oil at the top will overflow from the weir plate 214, so the proportion of refrigerant in the storage tank will gradually increase. It can be seen from the pressure value W calculated above that 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 lubricant in proportion P and refrigerant in proportion 1-P.

[0081] As the refrigerant is deposited from top to bottom, the amount of refrigerant entering the next storage tank will become less and less, so 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 is more likely to reach the static pressure preset value for the lower storage tank, 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 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 installation horizontal line of static pressure sensor P2 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 installation horizontal line of static pressure sensor P3 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 installation horizontal line of static pressure sensor P4 to the upper edge of the storage tank storing 85% lubricating oil and 15% refrigerant.

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

[0088] It can be understood 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 the static pressure preset value is specifically set, 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 of each static pressure sensor 207 is only a relative value with the same reference, rather than the actual static pressure. Therefore, the density of the liquid (such as refrigerant) does not have to be the actual saturation temperature, but can be a value close to the actual saturation temperature. Because when the refrigeration system is actually running, the saturation temperature of the refrigerant fluctuates and is not a fixed value. In principle, the static pressure preset value of each static pressure sensor 207 should be less than the actual static pressure value at the static pressure sensor 207. This is also the reason why the height should be subtracted by an adjustment height when determining the static pressure preset value of each static pressure sensor 207, and this adjustment height value must be a positive number.

[0091] In the embodiment of the present application, the oil storage chamber 208 is formed at the bottom of the chamber of the housing 201, and an oil drain pipe connected to the oil storage chamber 208 is provided at the bottom of the housing 201. An oil drain switch valve F5 is provided in the outflow direction of the oil drain pipe. One outlet of the oil drain switch valve F5 is connected to the oil return switch valve F6, and the other outlet is provided with a separation switch valve F7 and a separation check valve Z5 in sequence and connected to the top storage tank. Preferably, a sight glass S5 is provided on the housing 201 corresponding to the oil storage chamber 208.

[0092] With respect to the above-mentioned embodiment, when the pressure value detected by the static pressure sensor 207 in the storage tank reaches the static pressure preset value, the drain switch valve is triggered to open, so that the refrigerant at the bottom is discharged into the liquid outlet main pipe. 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 drain switch valve F5. Since the lubricating oil still contains a certain amount of refrigerant, when the quality of the lubricating oil does not meet the requirements, the discharged lubricating oil needs to continue to flow back to the top first storage tank 202 through the reflux pipe 210. It should be noted that the entrance of the reflux pipe 210 into the first storage tank 202 is preferably arranged above the upper edge of the weir plate 214.

[0093] In the 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: Send the mixed liquid to be separated into 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 fluorochlorocarbon or hydrofluorochlorocarbon 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 arcuate guide plate 212 is provided between the port of the liquid inlet pipe 209 and the first storage tank 202, for guiding the mixed liquid to be separated into the storage tank. One side of the guide plate 212 is close to the inner wall of the shell 201, and the distance between the guide plate 212 and the port of the liquid inlet pipe 209 is H2. Preferably, the guide plate 212 is inclined toward the axial direction, so the angle β between the guide plate 212 and the inner wall of the shell 201 should be greater than 90°, and more preferably, the angle β is 95° to 100°. The distance B that the width of the guide plate 212 exceeds the lower port of the liquid inlet pipe 209 is preferably 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 the present application is as follows: Figure 3 As shown, the upper edge of the storage tank is provided with a sawtooth notch 215, so that when the refrigerant containing foam overflows from top to bottom into the storage tank, the sawtooth notch 215 can play a role in defoaming the refrigerant. The angle γ of the sawtooth notch 215 is preferably 60° to 120°, and more preferably γ=90°. The height h of the sawtooth notch 215 is preferably 20 mm to 30 mm.

[0105] In another specific embodiment, continue to refer to Figure 2 An ultrasonic generator is provided on the side wall of the weir plate 214 of the first storage tank 202 away from the inner wall of the shell 201. The ultrasonic generator can generate a horizontal planar sound beam, which can cover the entire liquid surface of the first storage tank 202. The installation height of the ultrasonic generator is 30 mm to 50 mm lower than the upper edge of the storage tank weir plate 214. The planar sound beam generated by the ultrasonic generator can break the foam generated on the refrigerant liquid surface.

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

[0107] After the high-pressure 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 effects of collision, change of flow direction, and reduction of flow velocity, the refrigerant liquid and lubricating oil droplets are separated from the refrigerant gas, and then fall into the first storage tank 202 under the guiding effect of the guide plate 212. The liquid level of the first storage tank 202 gradually rises. When the volume ratio of the refrigerant and the lubricating oil reaches 7:3, the static pressure sensor P1 sends a signal to the discharge switch valve F1, the discharge 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 discharge switch valve F1 and the discharge check valve Z1; when the static pressure sensor P1 detects that the static pressure is less than the corresponding static pressure preset value, the discharge switch valve F1 is no longer opened, 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 the lubricating oil and the refrigerant in the upper part overflows to the second storage tank 203.

[0108] After entering the second storage tank 203, the liquid level gradually rises. When the volume ratio of refrigerant and 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 is no longer opened, 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 upper lubricating oil or the mixed liquid of lubricating oil and refrigerant overflows to 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, and the discharge switch valve F3 opens and closes with a delay. 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 is no longer opened, 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 upper lubricating oil or the mixed liquid of lubricating oil and refrigerant overflows to the fourth storage tank 205.

[0110] After entering the fourth storage tank 205, the liquid level gradually rises. When the volume ratio of refrigerant and 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 is no longer opened, 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 upper lubricating oil or the mixed liquid of lubricating oil and refrigerant overflows to 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; or the oil drain switch valve F5 and the separation switch valve F7 can be opened to return the liquid in the oil storage chamber 208 to the first storage tank 202 for further separation when the return oil switch valve F6 is closed according to the separation conditions of the refrigerant and the lubricating oil.

[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 reflux pipe when the oil discharge switch valve F5 and the separation switch valve F7 are opened.

[0113] Figure 4 This is another schematic diagram of the structure of a vertical oil separation device provided in an 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 Figure 2 The differences between the shown embodiments are:

[0115] The shell also includes an air outlet pipe 213 , which is located just above the top cover. The air outlet pipe 213 is configured to discharge the 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 housing 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 as follows:

[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 the 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 the refrigerant and the 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 is no longer opened, 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 upper lubricating oil or the mixed liquid of the lubricating oil and the refrigerant overflows to the second storage tank 203.

[0119] After entering the second storage tank 203, the liquid level gradually rises. When the volume ratio of refrigerant and 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 is no longer opened, 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 upper lubricating oil or the mixed liquid of lubricating oil and refrigerant overflows to 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, and the discharge switch valve F3 opens and closes with a delay. 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 is no longer opened, 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 upper lubricating oil or the mixed liquid of lubricating oil and refrigerant overflows to the fourth storage tank 205.

[0121] After entering the fourth storage tank 205, the liquid level gradually rises. When the volume ratio of refrigerant and 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 is no longer opened, 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 upper lubricating oil or the mixed liquid of lubricating oil and refrigerant 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 storage chamber 208, the liquid in the oil storage chamber 208 can be discharged by opening the oil discharge switch valve F5 and the oil discharge switch valve F6 when the separation switch valve F7 is closed according to the oil return operation requirements. Alternatively, the liquid in the oil storage chamber 208 can be sent back to the first storage tank 202 for further separation by opening the oil discharge switch valve F5 and the separation switch valve F7 when the oil return switch valve F6 is closed according to the separation of the refrigerant and the lubricating oil. When the refrigerant temperature is low, the viscosity of the lubricating oil is high and it is very difficult to discharge the oil. At this time, high-pressure gas can be sent from the air inlet pipe 217 into the oil storage chamber 208 to press the lubricating oil out of the oil storage chamber 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 closing 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 topmost 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 delay closing; 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.

[0127] The embodiment of the present application also 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] The embodiment of the present application also provides a refrigeration system applied to a low-pressure system, in which the liquid inlet pipe of the vertical oil separation device inputs a mixed liquid containing refrigerant and lubricating oil, the air inlet pipe inputs high-pressure gas, and the air outlet pipe is connected to the 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 can make various changes and modifications to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is also intended to include these modifications and variations.

Claims

1. A vertical oil separation device, characterized in that: include: A shell, the shell 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, wherein the plurality of storage tanks are staggered from top to bottom on the inner side wall of the shell, a liquid discharge pipe flowing to the liquid outlet main pipe is provided at the bottom of each storage tank, and a liquid discharge switch valve and a liquid discharge check valve are provided in the outflow direction of each liquid discharge pipe in sequence; A plurality of static pressure sensors, the plurality of static pressure sensors corresponding to the plurality of storage tanks one by one, and the vertical height between the installation position of each static pressure sensor and the lowest position of the corresponding storage tank is the same, and the static pressure sensor is associated with the drain switch valve of the corresponding storage tank; An oil storage chamber, the oil storage chamber is formed at the bottom of the chamber of the shell, an oil drain pipe connected to the oil storage chamber is provided at the bottom of the shell, 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 connected to 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, wherein the 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 the control module 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 plurality of static pressure sensors decrease in sequence from top to bottom.

3. The vertical oil separation device according to claim 2, characterized in that: The storage tanks are provided with four; 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 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 part of the oil storage chamber is separated by a concave closing cover, the bottom of the concave closing cover is connected with the oil storage chamber, and an oil discharge check valve is arranged at the connecting point, and an air inlet pipe is arranged at the upper part 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 sawtooth notch.

8. The vertical oil separation device according to claim 6, characterized in that: An ultrasonic generator is arranged 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, the method comprising: 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 as described in any one of claims 1 to 9.

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