A cyclone oil separator

Abstract

The application relates to a cyclone oil separator, which comprises a cylinder, an air inlet pipe, an air outlet pipe, an upper baffle and a lower baffle, the cylinder is internally provided with the upper baffle and the lower baffle, the upper baffle divides the cylinder into a diffuser section and an oil separation section, the upper diffuser section and the lower oil separation section are communicated through a riser pipe, the lower baffle divides the oil separation section into an upper separation section and a lower oil groove section, the air inlet pipe is communicated with the separation section, the air outlet pipe is communicated with the diffuser section, and the diffuser section is provided with diffuser blades. Under the premise of ensuring the oil separation efficiency, the cyclone oil separation pressure loss is reduced through recovery of dynamic pressure, and then the compressor pressure ratio is reduced, so that the refrigeration system energy efficiency is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of vapor compression refrigeration equipment, in particular to a cyclone oil separator for compressor exhaust. BACKGROUND

[0002] When the vapor compression machine with oil lubrication system (especially the oil-injected screw compressor) is working, the compressor exhaust will inevitably carry lubricating oil. If the lubricating oil enters and stays in the condenser and evaporator with the refrigerant vapor, it will affect the heat exchange efficiency, thereby making the whole machine performance worse. Moreover, if a large amount of lubricating oil enters the system with the refrigerant, it will cause insufficient oil supply to the compressor, affecting the normal operation of the compressor and even damaging it. Therefore, the oil-injected compressor exhaust generally needs to be provided with an oil separator to separate the oil from the refrigerant and return it to the compressor.

[0003] The working principle of the cyclone oil separator is to make the oil droplets with a higher density than the refrigerant gas move outward to the separator wall by centrifugal force acting on the fluid in the rotating flow field, and then move downward along the wall to the oil groove. The cyclone oil separator has the characteristics of simple structure, no moving parts, low cost and high separation efficiency, and is especially suitable for high-temperature, high-pressure and high-inlet-oil-concentration occasions, and its application in HVAC screw compressor units is becoming more and more widespread. The refrigerant gas is discharged from the top of the cyclone separator along the central axis to achieve gas-oil separation. To ensure the high-efficiency operation of the cyclone oil separator and make the oil droplets as clean as possible, the tangential velocity of the refrigerant gas in the cylinder is usually very high. The high-speed rotating gas stores a large amount of energy in the form of dynamic pressure. When the gas flows in the cylinder, the friction with the cylinder wall will cause a part of the mechanical energy to be lost. The tangential velocity component in the riser and the downstream pipe or flow channel will also be dissipated, which accounts for up to 80% of the total loss. This makes the pressure drop of the traditional cyclone oil separator larger than that of the gravity settling type oil separator and the steel wire mesh pad collision type oil separator (tests show that the pressure drop of the cyclone oil separator of the screw compressor unit of R134a and POE synthetic oil is between 30~80KPA at the nominal working condition, while the pressure drop of the collision type oil separator is generally below 10KPA). The traditional cyclone oil separator such as patents CN205066270U, CN205027012U and CN206944543U only focuses on the improvement of oil separation efficiency and does not consider the pressure loss caused by this oil return mode, resulting in a decrease in the energy efficiency of the refrigeration system. SUMMARY

[0004] The present application aims to overcome the above-mentioned deficiencies and provides a cyclone oil separator. By providing an expansion section for recovering the kinetic energy of the gas swirl in the oil separation, the system loss is reduced and the whole machine operation efficiency is improved under the premise of ensuring high oil separation efficiency.

[0005] The purpose of the present application is achieved in that:

[0006] A cyclone oil separator comprises a cylinder, an air inlet pipe, an air outlet pipe, an upper baffle and a lower baffle, the cylinder is provided with the upper baffle and the lower baffle, the upper baffle divides the cylinder into a diffuser section and an oil separation section, the diffuser section at the upper part and the oil separation section at the lower part are communicated through a riser pipe, the lower baffle divides the oil separation section into an upper separation section and a lower oil groove section, the lower baffle has the functions of cutting off the tail end of the cyclone and connecting the oil groove section, so that the secondary entrainment is reduced and the wear of the inner wall of the cylinder by the cyclone is reduced, the air inlet pipe is communicated with the separation section, the air outlet pipe is communicated with the diffuser section, and the diffuser section is provided with diffuser blades.

[0007] Preferably, the air inlet pipe and the air outlet pipe are annular volutes, the air inlet pipe is provided with a bell mouth, and has the function of rectifying the inlet fluid, and the air outlet pipe is provided with a bell mouth, and has the function of further recovering dynamic pressure.

[0008] Preferably, the air inlet pipe and the air outlet pipe are straight pipes, the inner walls of the air inlet pipe and the air outlet pipe are tangent to the wall of the cylinder, so as to reduce the local pressure loss at the transition position of the air inlet pipe and the air outlet pipe and the cylinder.

[0009] Preferably, the riser pipe is welded on the upper baffle, the top of the riser pipe is provided with a tapered bell mouth, and the tapered bell mouth has the function of initial dynamic pressure recovery, and the wall thickness of the inlet of the riser pipe is provided with a circular arc chamfer, so as to reduce the local pressure loss.

[0010] Preferably, the separation section is further provided with a float skirt, and the float skirt is sleeved outside the riser pipe.

[0011] Preferably, the float skirt is a tapered structure welded at the bottom of the riser pipe, and the edge of the float skirt is provided with a sawtooth, and the sawtooth has the functions of cutting off the oil film and reducing the adhesion of oil droplets on the float skirt.

[0012] Preferably, the float skirt is a straight cylinder welded on the upper baffle or welded on the inner wall of the cylinder.

[0013] Preferably, a plurality of diffuser blades are distributed in an expanding manner, the diffuser blades are installed on the top cover plate of the cylinder to form a vane diffuser.

[0014] Preferably, there is a gap between the lower baffle and the inner wall of the cylinder, so that the separated oil flow enters the oil groove section and the secondary entrainment is reduced.

[0015] The beneficial effects of the present application are:

[0016] Under the premise of ensuring the oil separation efficiency, the pressure loss of the cyclone oil separation is reduced by recovering the dynamic pressure (tests show that the present application can recover 50-80% of the dynamic pressure), and then the compression ratio of the compressor is reduced, so as to improve the energy efficiency of the refrigeration system.

[0017] The oil section is provided with a floating liquid skirt to prevent the wriggling leakage of oil drops, so that the oil separation performance is more stable. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 An external structure schematic diagram of a cyclone oil separator according to Embodiment 1 of the present application.

[0019] Figure 2 An internal structure schematic diagram according to Embodiment 1 of the present application (the floating liquid skirt is in a conical structure).

[0020] Figure 3 An internal structure schematic diagram according to Embodiment 1 of the present application (the floating liquid skirt is in a straight cylinder shape and is welded to the upper partition plate).

[0021] Figure 4 An internal structure schematic diagram according to Embodiment 1 of the present application (the floating liquid skirt is in a straight cylinder shape and is welded to the cylinder wall).

[0022] Figure 5 An A-A sectional view of Figure 2

[0023] Figure 6 A B-B sectional view of Figure 2

[0024] Figures 7-10 Different structure lower partition plate plan views.

[0025] Figure 11 An external structure schematic diagram of a cyclone oil separator according to Embodiment 2 of the present application.

[0026] Wherein:

[0027] Cylinder body 1; straight cylinder 1.1; top cover plate 1.2; bottom cover plate 1.3; air inlet pipe 2; air outlet pipe 3; upper partition plate 4; lower partition plate 5; pressure expansion section 6; gas lifting pipe 7; conical horn 7.1; separation section 8; oil groove section 9; oil outlet 10; floating liquid skirt 11; pressure expansion blade 12. DETAILED DESCRIPTION Embodiment 1

[0028] Referring to Figures 1-10 ​​This invention relates to a cyclone oil separator, comprising a cylinder 1, an inlet pipe 2, an outlet pipe 3, an upper baffle 4, and a lower baffle 5. The cylinder 1 is composed of a straight cylinder 1.1, a top cover plate 1.2, and a bottom cover plate 1.3. The top of the straight cylinder 1.1 is provided with the top cover plate 1.2, and the bottom of the straight cylinder is provided with the bottom cover plate 1. The cylinder 1 is provided with the upper baffle 4 and the lower baffle 5. The upper baffle 4 divides the cylinder into a diffuser section 6 and an oil separation section. The upper diffuser section 6 and the lower oil separation section are connected by a riser pipe 7. The lower baffle 5 further divides the oil separation section into an upper separation section 8 and a lower oil tank section 9. The inlet pipe 2 is connected to the separation section 8, and the outlet pipe 2 is connected to the diffuser section 6. The inlet pipe 2 and the outlet pipe 3 are in the form of an annular volute. The annular volute shape of the inlet pipe can widen the gas flow channel and reduce the flow velocity of the gas after it flows into the cylinder, thereby reducing the pressure drop. The annular volute-shaped exhaust pipe improves the diffusion effect and allows for greater pressure recovery. The riser pipe 7 is welded to the upper partition plate 4. The top of the riser pipe 7 is provided with a conical flare 7.1, which forms a flow guide channel, guiding the gas from axial flow to radial flow, causing the gas velocity to change slowly, reducing the pressure loss from direct impact on the top cover plate 1.2, and initially recovering dynamic pressure. The bottom of the cylinder 1 is provided with an oil outlet 10, which is close to the bottom cover plate 1.3.

[0029] The separation section 8 is also equipped with a floater skirt 11 to prevent oil droplets from leaking into the riser pipe. The floater skirt 11 is fitted over the riser pipe 7. Figure 2 The bleaching skirt 11 is a conical structure welded to the bottom of the riser pipe 7; the edge of the bleaching skirt is provided with serrations, which can promote the shedding of the liquid film and prevent oil droplets from adhering to the riser pipe and affecting the oil separation efficiency.

[0030] The bleaching skirt 11 is cylindrical and welded to the upper partition 4 (e.g., Figure 3 ) or welded to the inner wall of the cylinder (such as Figure 4 The pressure inside cylinder 1 is high near the cylinder wall and low at the center, creating a significant pressure gradient. Without a floater skirt, some separated oil droplets may creep along the lower surface of the upper baffle and the outer wall of the riser pipe, causing "leakage" into the riser pipe and affecting oil separation efficiency. Adding a floater skirt prevents oil droplet leakage under different operating conditions and loads, resulting in more stable oil separation performance.

[0031] The diffuser section 6 is provided with diffuser blades 12, and multiple diffuser blades 12 are distributed in an expanding manner. The diffuser blades 12 are installed on the top cover plate 1.1 to form a bladed diffuser, which can improve the diffusion efficiency at the rated operating point. The diffuser blades can be straight-walled or airfoil-shaped.

[0032] A notch exists between the lower baffle 5 and the inner wall of the cylinder 1, allowing the separated oil flow to pass along the edge of the cylinder wall. This prevents secondary entrainment of separated oil droplets by the tail end of the swirling flow and avoids the influence of the tail end of the swirling flow on the oil surface and level in the oil tank. The lower baffle can be square (e.g., Figure 7 ), ring (such as) Figure 8 ), round (such as) Figure 9 ) and petal-shaped (such as Figure 10 ) etc., such as Figure 7 and Figure 10 When the lower partition 5 is in contact with the cylinder 1, the lower partition is welded and fixed to the cylinder wall; for example Figure 8 and Figure 9 When the lower partition 5 is not in contact with the cylinder 1, the bottom of the lower partition is connected to a support plate, which has the function of preventing vortex, and is fixed to the bottom of the cylinder by the support plate. Example 2

[0033] like Figure 11 Both the inlet pipe 2 and the outlet pipe 3 are straight pipes, and the inner walls of both the inlet pipe 2 and the outlet pipe 3 are tangent to the cylinder wall. The rest of the structure is the same as in Embodiment 1.

[0034] In addition to the above embodiments, the present invention also includes other embodiments. All technical solutions formed by equivalent transformation or equivalent substitution should fall within the protection scope of the claims of the present invention.

Claims

1. A cyclone oil separator characterized by: The device comprises a cylinder, an air inlet pipe, an air outlet pipe, an upper partition plate and a lower partition plate, the cylinder is provided with the upper partition plate and the lower partition plate, the upper partition plate divides the cylinder into a diffuser section and an oil separation section, the diffuser section at the upper part and the oil separation section at the lower part are communicated through a riser pipe, the lower partition plate divides the oil separation section into an upper separation section and a lower oil groove section, the air inlet pipe is communicated with the separation section, the air outlet pipe is communicated with the diffuser section, and the diffuser section is provided with diffuser blades. The air inlet pipe and the air outlet pipe are annular volutes. The separation section is further provided with a float liquid skirt, and the float liquid skirt is sleeved outside the riser pipe. There is a gap between the lower partition plate and the inner wall of the cylinder.

2. A cyclone oil separator according to claim 1, wherein: The air inlet pipe and the air outlet pipe are straight pipes, and the air inlet pipe and the air outlet pipe are tangent to the wall of the cylinder.

3. A cyclone oil separator according to claim 1 or 2, characterised in that: The riser pipe is welded on the upper partition plate, and a conical horn is arranged at the top of the riser pipe.

4. A cyclone oil separator according to claim 1, wherein: The float liquid skirt is conical and welded at the bottom of the riser pipe, and the edge of the float liquid skirt is provided with sawteeth.

5. A cyclone oil separator according to claim 1 wherein: The float liquid skirt is a straight cylinder and is welded on the upper partition plate or the inner wall of the cylinder.

6. A cyclone oil separator according to claim 1 or 2, characterised in that: The diffuser blades are distributed in an expanding manner, the diffuser blades are installed on the top cover plate of the cylinder, and a vane diffuser is formed.

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