Gas-liquid separator

Abstract

To provide a gas-liquid separator capable of collecting a liquid at a downstream position from a swirling flow generating member regardless of the flow rate of a gas-liquid two-phase fluid.SOLUTION: In a gas-liquid separator 16 having a pipe member 21 in which a gas-liquid two-phase fluid flows and a swirling flow generating member 22 disposed at the inside of the pipe member 21 and swirling the gas-liquid two-phase fluid by the swirling flow generating member 22 to separate a gas and a liquid from each other, the swirling flow generating member 22 spirally extends around a center axis O1 of the pipe member 21 and has a vane part 32 where a tip part 32a in a pipe diameter direction is continued over the whole periphery of the pipe member 21 when the pipe member 21 is viewed from an axial direction; and a communication part 34 communicating between a first space X upstream of the swirling flow generating member 22 and a second space Y downstream of the swirling flow generating member 22 by forming a swollen part 25d extending in an axial direction in an inner peripheral surface 25a of the pipe member 21 between the pipe member 21 and the swirling flow generating member 22.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a gas-liquid separation device for separating a gas and a liquid contained in a gas-liquid two-phase fluid.

Background Art

[0002] Conventionally, there is known a gas-liquid separation device that swirls a gas-liquid two-phase fluid flowing through a pipe member by a swirl generating member and separates it into a gas and a liquid (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, in a conventional gas-liquid separation device, the swirl generating member has wing portions extending spirally around the central axis of the pipe member. And the tip of the wing portion in the pipe diameter direction is continuous over the entire circumference of the pipe member when viewed from the axial direction of the pipe member, and no gap extending in the axial direction can be formed between adjacent wing portions. Further, the entire length of the wing portion is in contact with the inner peripheral surface of the pipe. When the gas-liquid two-phase fluid is at a low flow rate, the liquid does not become fine granular, and naturally separates from the gas before swirling and becomes water droplets adhering to the inner peripheral surface of the pipe. The liquid that has become water droplets flows along the inside of the pipe member in the pipe axis direction by the flow of the gas, but the flow is inhibited because the wing portion of the swirl generating member is in contact with the inner peripheral surface of the pipe. For this reason, it is necessary to provide a drain pipe at an upstream position in the flow direction of the gas-liquid two-phase fluid with respect to the swirl generating member and guide the water droplets to a water storage tank before flowing into the arrangement region of the swirl generating member.

[0005] However, providing a drain pipe or connecting the drain pipe to a water storage tank deteriorates the degree of freedom in the arrangement of each member, resulting in a problem that it hinders cost reduction as a gas-liquid separation device.

[0006] The present invention has been made paying attention to the above problems, and an object thereof is to provide a gas-liquid separation device capable of collecting a liquid at a position downstream of a swirling flow generating member regardless of the flow velocity of a gas-liquid two-phase fluid.

Means for Solving the Problems

[0007] To achieve the above object, a gas-liquid separation device of the present invention includes a pipe member through which a gas-liquid two-phase fluid in which gas and liquid are mixed flows, and a swirling flow generating member disposed inside the pipe member. The swirling flow generating member swirls the gas-liquid two-phase fluid to separate the gas and the liquid. Here, the swirling flow generating member extends in a spiral shape around the central axis of the pipe member, and has a wing portion whose tip in the pipe diameter direction is continuous over the entire circumference of the pipe member when viewed from the axial direction of the pipe member. And between the pipe member and the swirling flow generating member, the inner peripheral surface of the pipe member project a part of it outward in the radial direction of the tube member By forming the bulging portion extending in the axial direction, a communication portion that communicates a first space upstream of the swirling flow generating member and a second space downstream of the swirling flow generating member is provided. Furthermore, the tip of the wing part in the radial direction of the tube member contacts the inner peripheral surface of the tube member except for the part facing the bulging part.

Effects of the Invention

[0008] Therefore, in the present invention, even when the tip in the pipe diameter direction of the wing portion of the swirling flow generating member is continuous over the entire circumference of the pipe member when viewed from the axial direction of the pipe member, regardless of the flow velocity of the gas-liquid two-phase fluid, the liquid can be collected at a position downstream of the swirling flow generating member.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3A

Figure 3B

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Mode for Carrying Out the Invention

[0010] Hereinafter, a mode for carrying out the gas-liquid separation device of the present invention will be described based on Example 1 shown in the drawings.

[0011] (Example 1) First, the configuration of the gas-liquid separation device in Example 1 will be described by dividing it into "overall system configuration of the application example", "detailed configuration of the gas-liquid separation device", and "detailed configuration of the swirling flow generating member".

[0012] [Overall System Configuration of the Application Example] FIG. 1 is an overall system diagram showing an exhaust gas recirculation system S of an internal combustion engine 1 to which the gas-liquid separation device 16 of Example 1 is applied. The gas-liquid separation device 16 of Example 1 is applied to the exhaust gas recirculation system S of the internal combustion engine 1 shown in FIG. 1. Here, the internal combustion engine 1 shown in FIG. 1 is a diesel engine mounted on a vehicle as a driving source for traveling and has four cylinders (not shown). An intake passage 2 and an exhaust passage 3 are connected to each cylinder, respectively.

[0013] The intake passage 2 has an air inlet 2a formed at its end. In order from the air inlet 2a side, an air cleaner 4 for intake filtration, a compressor 5a of a turbocharger 5, an intercooler 6 for cooling the intake air, and a throttle valve 7 for adjusting the intake air amount are provided. In the exhaust passage 3, in order from the internal combustion engine 1 side, a turbine 5b of the turbocharger 5, an exhaust purification catalyst 8 for purifying the exhaust, and an exhaust throttle valve 9 for adjusting the exhaust flow rate are provided. A muffler 10 is provided on the downstream side of the exhaust throttle valve 9, and an exhaust port 3a is formed at its tip.

[0014] The intake passage 2 and the exhaust passage 3 are connected by a low-pressure EGR passage 11 and a high-pressure EGR passage 12. Here, "EGR" is a technology (Exhaust Gas Recirculation) in which a part of the exhaust gas after combustion in the internal combustion engine 1 is taken out and re-intaken, and is also called exhaust gas recirculation.

[0015] The low-pressure EGR passage 11 connects the intake passage 2 upstream of the compressor 5a and the exhaust passage 3 downstream of the exhaust purification catalyst 8. On the other hand, the high-pressure EGR passage 12 connects the intake passage 2 downstream of the compressor 5a and the exhaust passage 3 upstream of the turbine 5b. As a result, in the low-pressure EGR passage 11, the exhaust gas that has passed through the turbine 5b is returned to the intake side of the compressor 5a. Also, in the high-pressure EGR passage 12, the exhaust gas before flowing into the turbine 5b is returned to the intake side that has passed through the compressor 5a.

[0016] The low-pressure EGR passage 11 is provided with an EGR cooler 13 for cooling the exhaust gas led to the intake passage 2 and a low-pressure EGR valve 14 for adjusting the flow rate of the exhaust gas refluxed to the intake passage 2 through the low-pressure EGR passage 11. The high-pressure EGR passage 12 is provided with a high-pressure EGR valve 15 for adjusting the flow rate of the exhaust gas refluxed to the intake passage 2 through the high-pressure EGR passage 12.

[0017] Here, in the low-pressure EGR passage 11, exhaust gas recirculation is enabled without reducing the exhaust gas flow rate through the turbine of the turbocharger 5, and the NOx reduction effect is significant. However, there is a concern about the generation of condensed water when the EGR gas is cooled by the EGR cooler 13 or mixed with air in cold weather. Therefore, in the exhaust gas recirculation system S of the first embodiment, a gas-liquid separation device 16 is installed at a position downstream of the low-pressure EGR valve 14 and upstream of the compressor 5a of the turbocharger 5 (the position surrounded by the dashed-dotted line X in FIG. 1), and the condensed water is collected and drained.

[0018] [Detailed Configuration of Gas-Liquid Separation Device] FIG. 2 is a cross-sectional view showing the gas-liquid separation device 16 of the first embodiment. The gas-liquid separation device 16 of the first embodiment includes a pipe member 21, a swirling flow generating member 22, a water storage tank 23, and a bypass pipe 24.

[0019] One end of the pipe member 21 communicates with the intake port 2a and the low-pressure EGR valve 14, and the other end communicates with the compressor 5a of the turbocharger 5. Exhaust gas in a state where gas and particulate liquid (condensed water) are mixed (hereinafter referred to as "gas-liquid two-phase fluid") flows through it. Further, when mounted on a vehicle, the pipe member 21 is arranged such that the central axis O 1 is along the horizontal direction, and is formed by connecting three tubular bodies, namely, a first pipe 25, a second pipe 26, and a third pipe 27. The first pipe 25, the second pipe 26, and the third pipe 27 are connected in order from the upstream side (the right side in FIG. 2, hereinafter referred to as the "fluid inflow side") in the flow direction of the gas-liquid two-phase fluid to the downstream side (the left side in FIG. 2, hereinafter referred to as the "fluid outflow side") in the flow direction of the gas-liquid two-phase fluid.

[0020] In the following description, the axial direction of the pipe member 21 (the direction along the central axis O 1 is referred to as the "pipe axis direction", and the radial direction of the pipe member 21 (the direction perpendicular to the central axis O 1 is referred to as the "pipe diameter direction". Further, the circumferential direction of the pipe member 21 (the circumferential direction centered on the central axis O 1 is referred to as the "pipe circumferential direction".

[0021] The first pipe 25 is a straight pipe member in which the swirling flow generating member 22 is disposed inside. Inside the first pipe 25, there are formed a swirling region 22a in which the swirling flow generating member 22 is disposed, a tapered region 25b in which the inner diameter dimension of the first pipe 25 gradually expands toward the fluid outflow side, and a stepped portion 25c against which the second pipe 26 abuts. Here, the tapered region 25b is formed on the fluid outflow side of the swirling region 22a. Also, the stepped portion 25c is formed on the fluid outflow side of the tapered region 25b. The inner diameter dimension of the first pipe 25 increases in the order of the swirling region 22a, the tapered region 25b, and the stepped portion 25c.

[0022] Furthermore, a bulging portion 25d is formed on the inner peripheral surface 25a of the first pipe 25. The bulging portion 25d is formed by protruding (concaving) a part of the inner peripheral surface 25a of the first pipe 25 outward in the pipe diameter direction with a step, and has a groove shape extending in the pipe axis direction. Also, the bulging portion 25d extends from the end portion (not shown) on the fluid inflow side of the first pipe 25 to at least the end portion on the fluid outflow side of the swirling region 22a. Furthermore, the bulging portion 25d has a predetermined width dimension W along the horizontal direction, and the central position 25e in the pipe circumferential direction is vertically below the central axis O of the pipe member 21 1 and is located.

[0023] Moreover, the bulging portion 25d has a flat surface on the bottom surface 25f along the horizontal direction, and the depth H (the distance from the inner peripheral surface 25a of the first pipe 25 to the bottom surface 25f of the bulging portion 25d) is the shallowest at the central position 25e in the pipe circumferential direction and gradually becomes deeper toward both end portions in the pipe circumferential direction.

[0024] The second pipe 26 is a T-shaped pipe member having a horizontal portion 26a connected to the first pipe 25 and a vertical portion 26b connected to the horizontal portion 26a in an orthogonal state.

[0025] One end of the horizontal portion 26a is insertable into the first pipe 25 and, in a state of being inserted into the first pipe 25, is in contact with the inner peripheral surface 25a of the first pipe 25. Also, one end of the horizontal portion 26a abuts against the stepped portion 25c. The axial direction of the horizontal portion 26a is the central axis O of the pipe member 211 It coincides with 1 and extends horizontally.

[0026] A drain opening 26c is formed at the connection portion between the horizontal portion 26a and the vertical portion 26b, and the horizontal portion 26a and the vertical portion 26b communicate with each other. The drain opening 26c opens downward in the gravitational direction (the vertical direction below the central axis O 1 ), and the vertical portion 26b extends along the gravitational direction from the horizontal portion 26a. Thereby, the liquid separated from the gas-liquid two-phase fluid flows down through the vertical portion 26b via the drain opening 26c by its own weight.

[0027] Furthermore, the vertical portion 26b is connected to a constricted portion 26d in which the flow area of the liquid gradually narrows downward in the middle portion. Thereby, the opening area of the tip opening 26e formed at the tip (lower end) of the constricted portion 26d is smaller than the opening area of the drain opening 26c. The vertical portion 26b, the drain opening 26c, the constricted portion 26d, and the tip opening 26e correspond to a drain pipe.

[0028] The third pipe 27 is a straight pipe member that can be inserted into the other end of the horizontal portion 26a of the second pipe 26 and is set to an outer diameter dimension that creates a gap α between it and the inner peripheral surface of the horizontal portion 26a when inserted into the second pipe 26. A spacer 28 is fitted into the gap α. The spacer 28 has a cylindrical shape that surrounds the entire circumference of the outer peripheral surface of the third pipe 27 and contacts each of the horizontal portion 26a of the second pipe 26 and the third pipe 27. That is, the other end of the horizontal portion 26a is blocked by the spacer 28. Also, the third pipe 27 is inserted into the second pipe 26 until one end portion 27a is positioned above the drain opening 26c. Furthermore, a vent hole 27b that penetrates the peripheral surface is formed in the third pipe 27 at a position protruding from the second pipe 26. The second end portion 24b of the bypass pipe 24 is connected to this vent hole 27b.

[0029] The water storage tank 23 has a tank body 23a installed below the vertical portion 26b of the second pipe 26. This tank body 23a has a first opening 23b formed on the upper surface, a second opening 23c formed on the side surface, and a drain opening (not shown) formed on the bottom surface.

[0030] The first opening 23b is connected to the tip opening 26e of the vertical portion 26b via a communication pipe 23d. The first end portion 24a of a bypass pipe 24 is connected to the second opening 23c. The drain opening can be opened and closed as appropriate, and when the liquid stored in the tank body 23a reaches a certain amount, it is opened to discharge the stored liquid outside the tank.

[0031] The bypass pipe 24 is a tubular body with both ends open. The first end portion 24a is connected to the second opening 23c formed in the tank body 23a, and the second end portion 24b is connected to a vent 27b formed in the third pipe 27. Thereby, the internal space of the tank body 23a communicates with the inside of the third pipe 27 via the bypass pipe 24.

[0032] [Detailed Configuration of the Swirling Flow Generation Member] The swirling flow generation member 22 of the first embodiment is disposed in the swirling region 22a of the first pipe 25, defines the flow direction of the gas-liquid two-phase fluid flowing through the pipe member 21, and turns the gas-liquid two-phase fluid into a swirling flow. As shown in FIG. 3A, the swirling flow generation member 22 includes a blade support portion 31 and a plurality (here, four) of blade portions 32 provided on the outer peripheral surface 31a of the blade support portion 31.

[0033] As shown in FIG. 3A, the blade support portion 31 has a conical shape with a tip portion 31b formed on an R surface. The swirling flow generation member 22 is disposed in the swirling region 22a with the tip portion 31b facing the fluid inflow side and the outer diameter dimension of the blade support portion 31 gradually increasing toward the fluid outflow side. Further, when the swirling flow generation member 22 is disposed in the swirling region 22a, the axial direction O 2 of the blade support portion 31 1 coincides with the central axis O

[0034] The plurality (four) of blade portions 32 each project in the pipe diameter direction from the outer peripheral surface 31a of the blade support portion 31 and are centered on the axial direction O 2 of the blade support portion 31 and around the axial direction O 2They are provided at equal angular intervals around and spirally surround it. Here, when the swirling flow generating member 22 is disposed in the swirling region 22a, the axial direction O of the blade support portion 31 2 coincides with the central axis O of the pipe member 21 1 . Therefore, each blade portion 32 extends while curving spirally about the central axis O of the pipe member 21 in a state where the swirling flow generating member 22 is disposed in the swirling region 22a 1 .

[0035] Furthermore, when the swirling flow generating member 22 is disposed in the swirling region 22a, the tip 32a in the pipe diameter direction of each blade portion 32 contacts the inner peripheral surface 25a (inner peripheral surface of the pipe member 21) of the first pipe 25 except for the portion facing the bulging portion 25d formed in the first pipe 25. On the other hand, the winding angle θ1 of each blade portion 32 with respect to the blade support portion 31 is set to approximately 90°. The "winding angle θ1" is an angle formed by the protruding direction L1 of the end portion 32b on the fluid inflow side of the blade portion 32 and the protruding direction L2 of the end portion 32c on the fluid outflow side of the blade portion 32 when the swirling flow generating member 22 is viewed from the pipe axis direction, as shown in FIG. 4. Since the winding angle θ1 is approximately 90°, the end portion 32c on the fluid outflow side of the blade portion 32 overlaps the end portion 32b on the fluid inflow side of the adjacent blade portion 32 in the pipe axis direction when the swirling flow generating member 22 is viewed from the pipe axis direction. Note that due to the R shape generated at the end portions 32b and 32c and the draft angle of the mold, the end portion 32b on the fluid inflow side and the end portion 32c on the fluid outflow side of the adjacent blade portions 32 may not overlap in the pipe axis direction

[0036] And, since the winding angle θ1 of the plurality (four) of blade portions 32 is set to approximately 90° for the swirling flow generating member 22, when viewed from the pipe axis direction, as shown in FIG. 4, the tips 32a of the blade portions 32 are continuous over the entire circumference of the pipe member 21. That is, it is possible to surround the central axis O of the pipe member 21 with a locus along the tip 32a in the pipe diameter direction of the blade portion 32 when the swirling flow generating member 22 is viewed from the pipe axis direction 1 . As a result, a gap extending in the pipe axis direction cannot be generated between the opposing side surfaces 32x of the adjacent blade portions 32

[0037] And in the gas-liquid separator 16 of the first embodiment, a communication portion 34 is provided by forming a bulging portion 25d on the inner peripheral surface 25a of the first pipe 25 which is the pipe member 21, between the inner peripheral surface 25a of the first pipe 25 and the tip 32a of the blade portion 32 of the swirling flow generating member 22. That is, the communication portion 34 is formed on the inner peripheral surface 25a of the pipe member 21. The communication portion 34 extends along the pipe axis direction, and communicates the first space X (see FIG. 2) upstream (fluid inflow side) of the swirling region 22a where the swirling flow generating member 22 is disposed, and the second space Y (see FIG. 2) downstream (fluid outflow side) of the swirling region 22a where the swirling flow generating member 22 is disposed. Further, the central position of the communication portion 34 in the circumferential direction of the pipe coincides with the central position 25e in the circumferential direction of the bulging portion 25d, and is located vertically below the central axis O 1 and is located vertically below the central axis O.

[0038] Furthermore, the height of the communication portion 34 coincides with the depth H of the bulging portion 25d, and is set to be the smallest at the central position in the circumferential direction of the pipe and the largest at both ends in the circumferential direction of the pipe. The height of the communication portion 34 (the depth H of the bulging portion 25d) is set to about 5% of the radius dimension of the pipe member 21 at the central position in the circumferential direction of the pipe where it is the smallest. Also, the horizontal width of the communication portion 34 coincides with the width dimension W of the bulging portion 25d, and is set to about 15% of the circumferential length of the inner peripheral surface of the pipe member 21 (the inner peripheral surface 25a of the first pipe 25) in the swirling region 22a.

[0039] Next, the operation of the gas-liquid separator 16 of the first embodiment will be described separately as "liquid collection operation at high flow velocity" and "liquid collection operation at low flow velocity".

[0040] "Liquid collection operation at high flow velocity" In the exhaust gas recirculation system S shown in FIG. 1, the outside air taken in from the intake port 2a and the exhaust gas taken in from the exhaust passage 3 via the low-pressure EGR passage 11 flow into the compressor 5a of the turbocharger 5 at a speed of 5 m / s to 110 m / s. The outside air and the exhaust gas contain moisture, and when the cooling water temperature is too low or the outside air temperature is low when cooling the gas flowing into the compressor 5a with the EGR cooler 13, condensed water is generated, and it mixes with the gas to become a gas-liquid two-phase fluid.

[0041] When the flow velocity of the gas-liquid two-phase fluid is relatively high (at high flow velocities, for example, 20 m / s to 110 m / s), the condensed water becomes fine granular and flows in a mixed phase with the gas.

[0042] In the gas-liquid separator 16 of Example 1, as shown in FIG. 2, a swirling flow generating member 22 is disposed inside the first pipe 25 of the pipe member 21. The swirling flow generating member 22 has a plurality of blade portions 32 that project in the pipe diameter direction from the outer peripheral surface 31a of the blade support portion 31 and are curved in a spiral shape around the central axis O1 of the pipe member 21.

[0043] Therefore, as shown in FIG. 5, when the gas-liquid two-phase fluid flowing into the pipe member 21 passes through the swirling region 22a where the swirling flow generating member 22 is installed, the flow direction is defined by flowing along the blade portions 32, and it becomes a swirling flow that flows while swirling. Then, due to the centrifugal force generated by the swirling of the gas-liquid two-phase fluid, the liquid with a large mass is induced toward the inner peripheral surface 25a of the first pipe 25. The liquid induced toward the inner peripheral surface 25a of the first pipe 25 adheres to the inner peripheral surface 25a of the first pipe 25, aggregates into water droplets, and is separated from the gas. On the other hand, the air from which the liquid has been separated flows linearly along the pipe axis direction while swirling, flows from the first pipe 25 to the second pipe 26, and flows into the third pipe 27.

[0044] In contrast, the liquid that has been atomized and separated from the gas, as shown in FIG. 5, remains attached to the inner peripheral surface 25a of the first pipe 25 due to the flow of the swirling flow, passes through the taper region 25b from the swirling region 22a, and flows into the second pipe 26. The liquid flowing into the second pipe 26 flows while remaining attached to the inner peripheral surface 26f of the second pipe 26, flows into the drain opening 26c, and flows down the vertical portion 26b. Then, it is discharged through the tip opening 26e and stored in the tank body 23a.

[0045] In this way, when the gas-liquid two-phase fluid flows at a high flow rate, the gas-liquid separation device 16 of Example 1 can swirl the gas-liquid two-phase fluid by the swirl flow generating member 22 and separate the gas and the liquid by centrifugal force. Further, the liquid can be guided toward the inner peripheral surface 25a of the first pipe 25 and adhered to the inner peripheral surface 25a, so that the liquid can be collected in the water storage tank 23 while suppressing re-scattering of the liquid.

[0046] [Liquid collection effect at low flow rate] In the exhaust reflux system S of Example 1, when the flow rate of the gas-liquid two-phase fluid is relatively slow (at low flow rates, for example, 5 m / s to 20 m / s), the condensed water is not likely to become fine particles. In this case, as shown in FIG. 6, before the gas-liquid two-phase fluid flows into the swirl region 22a where the swirl flow generating member 22 is disposed, that is, before swirling, the gas and the liquid naturally separate, and the liquid that has become water droplets adheres to the inner peripheral surface 25a of the first pipe 25. The gas, when passing through the swirl region 22a, flows along the wing portion 32 to form a swirl flow, and flows linearly along the pipe axis direction while swirling, flows from the first pipe 25 to the second pipe 26, and flows into the third pipe 27.

[0047] On the other hand, the liquid adhering to the inner peripheral surface 25a of the first pipe 25 cannot flow in a mixed phase with the gas and flows toward the swirl region 22a while remaining adhered to the inner peripheral surface 25a of the first pipe 25 due to the flow of the gas.

[0048] Here, in Example 1, the swirl flow generating member 22 has a wing portion 32 that surrounds the wing support portion 31. The wing portion 32 has a tip 32a in the pipe diameter direction that contacts the inner peripheral surface 25a of the first pipe 25, and the winding angle θ1 with respect to the wing support portion 31 is set to about 90°, and is continuous over the entire circumference of the pipe member 21 when viewed from the pipe axis direction. Further, a communication portion 34 is formed by a bulging portion 25d formed in the first pipe 25, which is the pipe member 21, between the inner peripheral surface 25a of the first pipe 25 and the wing portion 32 of the swirl flow generating member 22. The communication portion 34 extends along the pipe axis direction between the first pipe 25 and the swirl flow generating member 22, and communicates the first space X upstream of the swirl region 22a and the second space Y downstream of the swirl region 22a.

[0049] Therefore, the liquid (water droplets) separated from the gas before flowing into the swirling region 22a flows through the communication portion 34 and horizontally flows inside the pipe member 21 around the central axis O 1 and can flow from the first space X into the second space Y. That is, the liquid adhering to the inner peripheral surface 25a of the first pipe 25 is not obstructed by the swirling flow generating member 22 and can smoothly pass through the swirling region 22a.

[0050] Then, the liquid that has passed through the swirling region 22a continues to adhere to the inner peripheral surface 25a of the first pipe 25, passes through the tapered region 25b, and flows into the second pipe 26. The liquid flowing into the second pipe 26 flows while adhering to the inner peripheral surface 26f of the second pipe 26, flows into the drain opening 26c, and flows down the vertical portion 26b. Then, it is discharged through the tip opening 26e and stored in the tank body 23a.

[0051] Thus, in the gas-liquid separator 16 of the first embodiment, even when the flow velocity of the gas-liquid two-phase fluid is slow and the gas and the liquid are naturally separated before passing through the swirling region 22a, the liquid can flow through the communication portion 34 provided between the inner peripheral surface 25a of the first pipe 25 and the wing portion 32. For this reason, even if the tip 32a of the wing portion 32 is continuous over the entire circumference of the pipe member 21 when viewed from the pipe axis direction, the flow of the liquid is not obstructed by the wing portion 32, and the liquid can be collected on the fluid outflow side of the swirling flow generating member 22. As a result, regardless of the flow velocity of the gas-liquid two-phase fluid, the liquid can be collected at a position downstream of the swirling flow generating member 22.

[0052] And in the gas-liquid separator 16 of the first embodiment, the communication portion 34 is formed by a bulging portion 25d extending in the pipe axis direction formed on the inner peripheral surface 25a of the first pipe 25 which is the pipe member 21. Therefore, it is not necessary to form partial notches, depressions, etc. in the tip 32a of the wing portion 32 of the swirling flow generating member 22, and the swirling flow generating member 22 can be easily formed.

[0053] In addition, the bulging portion 25d formed in the first pipe 25 that forms the communication portion 34 has a groove shape extending in the pipe axis direction. Therefore, the shape of the communication portion 34 can be easily set to a desired shape by adjusting the depth H and the horizontal width dimension W of the bulging portion 25d.

[0054] In addition, the bulging portion 25d is formed on a part of the inner peripheral surface 25a of the first pipe 25. That is, the width dimension W of the bulging portion 25d is shorter than the circumferential length of the inner peripheral surface 25a. Therefore, the communication portion 34 is a space formed in a part in the circumferential direction of the pipe between the inner peripheral surface 25a of the first pipe 25 and the wing portion 32. As a result, the tip 32a of the wing portion 32 contacts the inner peripheral surface 25a of the first pipe 25 except for the portion facing the communication portion 34. Therefore, the swirling flow generating member 22 can be supported by the pipe member 21, and the strength against the vibration of the swirling flow generating member 22 can be ensured.

[0055] In addition, in the gas-liquid separation device 16 of the first embodiment, the central position in the circumferential direction of the pipe of the communication portion 34 (the central position 25e in the circumferential direction of the bulging portion 25d) is below the central axis O of the pipe member 21 when viewed from the pipe axis direction. 1 As a result, the liquid that has flowed down to the lower part of the pipe member 21 due to its own weight can flow into the communication portion 34, so that the collection of the liquid can be performed smoothly.

[0056] In particular, in the first embodiment, the central position in the circumferential direction of the pipe of the communication portion 34 (the central position 25e) is located below the central axis O of the pipe member 21 in the vertical direction. Therefore, the liquid that has flowed down to the lower part of the pipe member 21 due to gravity can surely flow into the communication portion 34. 1 As a result, the liquid that has flowed down to the lower part of the pipe member 21 due to gravity can surely flow into the communication portion 34.

[0057] Moreover, in the gas-liquid separator 16 of the first embodiment, a gap α is formed between the second pipe 26 and the third pipe 27. Therefore, the liquid adhering to the inner peripheral surface 26f of the second pipe 26 enters the gap α, preventing the liquid from flowing into the third pipe 27. Further, since the third pipe 27 on the fluid outflow side is inserted into the second pipe 26, an increase in the outer diameter dimension of the pipe member 21 can be suppressed, and the space required for installing the gas-liquid separator 16 can be suppressed.

[0058] Also, in the first embodiment, a spacer 28 that seals the gap α is fitted to the other end of the horizontal portion 26a of the second pipe 26. Therefore, it is possible to prevent gas from leaking between the second pipe 26 and the third pipe 27, and the gas can flow smoothly into the third pipe 27.

[0059] Furthermore, in the first embodiment, the third pipe 27 and the water storage tank 23 communicate with each other via a bypass pipe 24. Therefore, the internal pressure of the water storage tank 23 can be made negative by the airflow flowing through the third pipe 27, and the flow of the liquid flowing down the vertical portion 26b can be made smooth. In FIG. 2, the bypass pipe 24 is connected to the second opening 23c formed on the side surface of the tank body 23a, but the present invention is not limited to this. For example, the bypass pipe 24 may be connected to an opening formed on the upper surface of the tank body 23a.

[0060] As described above, the gas-liquid separator of the present invention has been described based on the first embodiment. However, the specific configuration is not limited to the first embodiment, and design changes and additions are allowed as long as the gist of the invention according to each claim of the claims is not deviated from.

[0061] In the gas-liquid separator 16 of the first embodiment, an example is shown in which the central position in the circumferential direction of the pipe of the communication portion 34 (the central position 25e in the circumferential direction of the pipe of the bulging portion 25d) is located vertically below the central axis O of the pipe member 21. However, the present invention is not limited to this. For example, as shown in FIG. 7, the central position in the circumferential direction of the pipe of the communication portion 34 (the central position 25e in the circumferential direction of the pipe of the bulging portion 25d) is set as the central axis O. 1 is shown to be located vertically below. However, the present invention is not limited to this. For example, as shown in FIG. 7, the central position in the circumferential direction of the pipe of the communication portion 34 (the central position 25e in the circumferential direction of the pipe of the bulging portion 25d) is set as the central axis O. 1It may be set at a position shifted by a predetermined angle in the swirling direction of the gas-liquid two-phase fluid (clockwise direction in FIG. 7) with respect to the vertically downward position.

[0062] Thus, even if a part of the liquid adhering to the inner peripheral surface 25a of the first pipe 25 is flowed in the circumferential direction of the pipe by the swirling flow, it can flow into the communication portion 34. For this reason, the flow of the liquid is not inhibited by the swirling flow generating member 22, and it can be appropriately collected downstream of the swirling flow generating member 22.

[0063] Note that the swirling direction of the swirling flow generating member 22 is not limited to the clockwise direction shown in FIG. 7, and it may be swirled in the opposite direction. Further, the angle by which the central position in the circumferential direction of the communication portion 34 (the central position 25e in the circumferential direction of the bulging portion 25d) is shifted with respect to the vertical direction, that is, the central axis O 1 The line segment extending vertically downward through and the central axis O 1 The angle formed by the line segment connecting the central position in the circumferential direction of the communication portion 34 (the central position 25e in the circumferential direction of the bulging portion 25d) can be arbitrarily set.

[0064] Further, in the gas-liquid separation device 16 of the first embodiment, an example in which the bulging portion 25d is formed by protruding (concaving) a part of the inner peripheral surface 25a of the first pipe 25 outward in the pipe diameter direction with a step is shown. However, it is not limited to this, and a part of the inner peripheral surface 25a of the first pipe 25 may be gradually protruded outward in the pipe diameter direction to form the bulging portion 25d, and the communication portion 34 may be provided by forming this bulging portion 25d. That is, for example, as shown in FIG. 8, the circumferential shape viewed from the pipe axis direction of the first pipe 25 may have the upper half above the horizontal line L passing through the central axis O 1 as a perfect circle and the lower half below the horizontal line L as an ellipse. The perfect circle is a circle centered on the central axis O 1 The ellipse is an ellipse having a major axis along the vertical direction passing through the central axis O 1 Here, in the swirling flow generating member 22, all the plurality of blade portions 32 have the same shape, and when viewed from the pipe axis direction, the locus along the tip 32a of the blade portion 32 is the central axis O

[0065] ​1 Therefore, in the swirling region 22a, a gap is generated between the inner circumferential surface 25a of the first pipe 25 and the tip 32a of the blade portion 32 in the region below the horizontal line L, forming a communication portion .

[0066] In the example shown in FIG. 8, the circumferential shape of the first pipe 25 as viewed from the axial direction is such that the lower half of the pipe below the horizontal line L is parallel to the central axis O. 1 In this example, the central axis O is an ellipse with a semimajor axis along the vertical direction passing through the center. 1 9, the position β at which the communication portion 34 is deepest may be set to a position below the central axis O. 1 9. Alternatively, the swirl flow generating member 22 may be set at a position shifted by a predetermined angle with respect to the vertically downward position of the gas-liquid two-phase fluid in the swirling direction (clockwise direction in FIG. 9) caused by the swirl flow generating member 22.

[0067] In the gas-liquid separation device 16 of the first embodiment, the swirling flow generating member 22 has a conical blade support portion 31 and a plurality of blade portions 32 protruding from the outer circumferential surface 31a of the blade support portion 31. However, the present invention is not limited to this, and the swirling flow generating member may be formed of, for example, a plate member twisted in a spiral shape. That is, the central axis O of the pipe member 21 is 1 The present invention can be applied to any gas-liquid separation device equipped with a swirling flow generating member having a wing portion that is spirally curved around the center and whose radially outer tip has a wing portion that continues around the entire circumference of the pipe member 21 when viewed from the axial direction of the pipe.

[0068] In addition, in the first embodiment, the swirl flow generating member 22 has four blades 32, and the wrapping angle θ1 is set to about 90°. However, as long as the tips 32a of the blades 32 are continuous over the entire circumference of the pipe member 21 when viewed from the pipe axis direction, the number of blades 32 and the wrapping angle θ1 can be set arbitrarily.

[0069] In Example 1, an example in which the water storage tank 23 is connected to the tip opening 26e of the vertical portion 26b was shown. However, the vertical portion 26b and the water storage tank 23 do not necessarily have to be installed. The liquid discharged from the drain opening 26c may be discharged to the outside of the pipe member 21 without being stored. Furthermore, the bypass pipe 24 does not necessarily have to be provided.

[0070] Also, in Example 1, an example in which the gas-liquid separation device 16 is installed at a position downstream of the low-pressure EGR valve 14 and upstream of the compressor 5a of the turbocharger 5 (the position surrounded by the dashed-dotted line X in FIG. 1) in the exhaust gas recirculation system S was shown. However, the present invention is not limited to this. Since it can be installed at a position where condensed water is generated in the exhaust gas recirculation system S, the gas-liquid separation device 16 may be installed at a position downstream of the intercooler 6 and upstream of the cylinder intake port of the internal combustion engine 1 (the position surrounded by the dashed-dotted line Y in FIG. 1).

[0071] Furthermore, in Example 1, an example in which the internal combustion engine 1 is a diesel engine mounted on a vehicle was shown. However, the present invention is not limited to this, and the internal combustion engine 1 may be a gasoline engine and is also applicable.

[0072] And in Example 1, an example in which the gas-liquid separation device 16 is applied to the exhaust gas recirculation system S of the internal combustion engine 1 was shown. However, the present invention is not limited to this, and for example, it may be applied to a refrigeration cycle device to separate a gaseous refrigerant and a liquid refrigerant. That is, the gas-liquid separation device of the present invention can be applied to a device that separates gas and liquid from a gas-liquid two-phase fluid.

[0073] Furthermore, the shape of the pipe member 21, the connection locations such as the first pipe 25, the dimensional sizes of the diameters, the materials used, etc. are not limited to those shown in Example 1, and can be arbitrarily set.

Explanation of Reference Numerals

[0074] 16 Gas-liquid separation device 21 Pipe member 22 Swirling flow generating member 22a Swirling region 23 Water storage tank 25 First pipe 25a Inner peripheral surface 25d Bulging portion 25e Central position in the circumferential direction of the pipe 26 Second pipe 26a Horizontal portion 26b Vertical portion 26c Drainage opening 27 Third pipe 31 Wing support portion 32 Wing portion 32a Tip 34 Communication portion X First space Y Second space

Claims

1. A gas-liquid separation device comprising a pipe member through which a gas-liquid two-phase fluid in which gas and liquid are mixed flows, and a swirling flow generating member disposed inside the pipe member, wherein the swirling flow generating member swirls the gas-liquid two-phase fluid to separate the gas and the liquid. The swirling flow generating member is curved in a spiral shape about the central axis of the pipe member, and has a wing portion whose tip in the radial direction of the pipe member is continuous over the entire circumference of the pipe member when viewed from the axial direction of the pipe member. A communication portion is provided between the pipe member and the swirling flow generating member by forming a bulging portion that projects a part of the inner peripheral surface of the pipe member outward in the radial direction of the pipe member and extends in the axial direction, and communicates a first space upstream of the swirling flow generating member and a second space downstream of the swirling flow generating member. The tip of the wing portion in the radial direction of the pipe member contacts the inner peripheral surface of the pipe member except for the portion facing the bulging portion. A gas-liquid separation device characterized by the above.

2. In the gas-liquid separation device according to Claim 1, the central position in the circumferential direction of the pipe of the communication portion is located below the central axis in the direction of gravity. A gas-liquid separation device characterized by the above.

3. In the gas-liquid separation device according to Claim 2, the central position in the circumferential direction of the pipe of the communication portion is shifted in the swirling direction of the gas-liquid two-phase fluid by the swirling flow generating member from the vertically downward position of the central axis. A gas-liquid separation device characterized by the above.

Images