Gas-liquid separation type hydraulic turbine

Abstract

The invention discloses a gas-liquid separation type hydraulic turbine which comprises a pump body, a main impeller, a pump cover and an impeller nut used for fixing the main impeller, sealing rings are arranged on a front cover plate and a rear cover plate of the main impeller, vent holes are formed in the rear cover plate of the main impeller, centrifugal blades are arranged on the back face of the rear cover plate of the main impeller, and a separation cavity is formed below the pump cover. An exhaust hole is formed in the bottom of the pump cover and communicated with the vent hole through the separation cavity, a one-way exhaust valve is connected to the exhaust hole, a liquid drainage hole is formed in the top of the pump cover and connected with a turbine outlet through a liquid conveying pipe, and the liquid drainage hole is communicated with the turbine outlet through a liquid conveying pipe. According to the gas-liquid separation type hydraulic turbine, efficient gas-liquid separation and separated conveying are achieved at the outlet of the main impeller. According to the design, the problem of intermittent flow channel blockage caused by agglomeration of a gas medium at the outlet of the main impeller is effectively prevented, so that the recovery efficiency and the operation stability of the hydraulic turbine in the natural gas desulfurization process are remarkably improved.

Description

Technical Field

[0001] The present invention relates to a hydraulic turbine, in particular to a gas-liquid separation type hydraulic turbine. Background Art

[0002] In the natural gas purification process, there is a large amount of residual pressure fluid in each purification unit. The traditional operation mode is to transport it after reducing the pressure through devices such as pressure reducing valves, which leads to waste of residual pressure. Hydraulic turbines can effectively recover the residual pressure of fluids in these industrial processes. In the natural gas purification process of hydraulic turbine energy recovery, gas precipitation is inevitable at the outlet of the main impeller due to factors such as temperature, pressure or solubility. That is, the fluid at the turbine inlet is liquid, while the outlet becomes gas-liquid two-phase. Due to the difference in gas-liquid density, this gas-liquid two-phase flow causes the gas phase medium to agglomerate at the outlet of the main impeller, resulting in intermittent flow channel blockage. This phenomenon can reduce the efficiency of the hydraulic turbine and cause unstable operation. Summary of the invention

[0003] The technical task of the present invention is to provide a gas-liquid separation hydraulic turbine in view of the above deficiencies in the prior art.

[0004] The technical solution adopted by the present invention to solve the technical problem is: a gas-liquid separation type hydraulic turbine, including a pump body, a main impeller and a pump cover, and an impeller nut for fixing the main impeller, the main impeller is composed of a small rotation increasing blade, a main blade and a centrifugal blade, the bending direction of the centrifugal blade and the main blade are opposite, the centrifugal blade is located on the back of the rear cover of the main impeller, a sealing ring is provided on the front and rear covers of the main impeller, a vent hole is provided on the rear cover of the main impeller, a separation chamber is provided below the pump cover, and a drainage is provided at the bottom of the pump cover. The air hole is connected with the air vent through a separation chamber, a one-way exhaust valve is connected to the air hole, a drainage hole is arranged on the top of the pump cover, the drainage hole is connected with the turbine outlet through a liquid infusion tube, the outer contour of the impeller nut is an arc-shaped structure, and the outer contour of the impeller nut has the same curvature as the rear cover plate of the main impeller; the outer contour of the impeller nut is designed to be an arc-shaped structure, and such a design is helpful for the gas to pass through the air vent, because a reverse jet is generated at the center of the main impeller outlet, which can make the fluid push the gas phase to flow out of the air vent.

[0005] Assume that the turbine flow is Q, the air content is α, where 0<α<15%, the radius at the main impeller inlet is R1, the radius at the main impeller outlet is R2, and the hub radius of the main impeller is R h , the number of main blades on the main impeller is Z1, then the radius of the sealing ring is The sealing rings at the front and rear reduce the volume loss on the one hand, and prevent the leakage of fluid from the rear cavity from affecting the centrifugal blades on the other hand, thereby improving the turbine efficiency.

[0006] The outlet angle of the main blade , the component of the absolute velocity at the main impeller outlet in the circumferential velocity , where v m2 is the main impeller outlet axial velocity, u2 is the outlet circumferential velocity, v u1 R is the component of the inlet absolute velocity in the circumferential velocity, a is the radius of the intersection of the outlet edge and the centerline of the flow channel; the outlet angle calculated in this way can make the fluid at the main impeller outlet have a certain rotational component, that is, a large-scale spiral vortex and reverse jet are generated at the main impeller outlet, which helps the gas to pass through the vent.

[0007] The inlet width of the rotation increasing blade , L2 is the width of the main impeller flow channel at the inlet position of the swirl increasing blade, the outlet radius of the swirl increasing blade is equal to the outlet radius of the main impeller, and the outlet hub radius R of the swirl increasing blade is h2 =2R h The axial flow area of ​​the swirl-increasing blade changes evenly from the inlet to the outlet. The wrap angle of the swirl-increasing blade is 0.05~0.15 times the wrap angle of the main blade. The outlet angle β4 of the swirl increasing blade is 70°~90°; the set swirl increasing blade enhances the spiral vortex and flow velocity at the outer ring of the main impeller outlet, thereby increasing the back jet intensity of the inner ring, which helps to further improve the efficiency of gas passing through the vent.

[0008] Further improvement: The distance from the center of the vent hole to the center of the pump body is , the diameter of the vent hole , where Z3 is the number of vents, .

[0009] Further improvement: the end surface clearance between the centrifugal blade and the pump cover is 0.3~1.5mm, and the radius of the inner side of the centrifugal blade is , the outer radius , the number of centrifugal blades is (n=1, 3, 5), the outlet angle of the centrifugal blade is The functions of centrifugal blades are: first, to separate gas and liquid, and second, to transport liquid. The gas and a small amount of liquid passing through the vent hole are subjected to different centrifugal forces due to the difference in gas-liquid density. The gas is transported axially out of the exhaust hole, and the liquid is transported by the centrifugal blades to the drain hole, and then transported to the turbine outlet through the infusion pipe.

[0010] Further improvement: the diameter of the exhaust hole is .

[0011] Advantages of the present invention: The gas-liquid separation hydraulic turbine of the present invention realizes efficient gas-liquid separation and separate transportation at the main impeller outlet. This design effectively prevents the intermittent flow channel blockage problem caused by the agglomeration of the gas medium at the main impeller outlet, thereby significantly improving the recovery efficiency and operation stability of the hydraulic turbine in the natural gas desulfurization process. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a schematic diagram of the overall structure of the present invention.

[0013] Figure 2 It is a structural schematic diagram of the main impeller of the present invention.

[0014] Figure 3 It is a schematic diagram of the dimensions of the main impeller of the present invention.

[0015] Figure 4 It is a schematic diagram of the inlet and outlet angles of the rotation-increasing blade of the present invention.

[0016] Figure 5 It is a schematic diagram of the dimensions of the inlet width of the rotation-increasing small blade of the present invention.

[0017] Figure 6 It is a schematic diagram of the impeller nut structure of the present invention.

[0018] Figure 7 It is a schematic diagram of the dimensions of the exhaust hole of the present invention.

[0019] Figure 8 This is a diagram of the CFD reverse jet phenomenon of the present invention.

[0020] Fig. 9 It is a schematic diagram of the dimensions of the centrifugal blade outlet angle of the present invention.

[0021] In the figure: pump body 1, infusion tube 2, main impeller 3, sealing ring 31, centrifugal blades 32, main blades 33, vents 34, small rotation-increasing blades 35, impeller nut 4, outer contour 41, pump cover 5, separation chamber 51, exhaust hole 52, drainage hole 53, one-way exhaust valve 6. DETAILED DESCRIPTION

[0022] The present invention is described in detail below with reference to the accompanying drawings.

[0023] As shown in the figure, a gas-liquid separation hydraulic turbine comprises a pump body 1, a main impeller 3 and a pump cover 5, and an impeller nut 4 for fixing the main impeller 3. The main impeller 3 is composed of a small rotation-increasing blade 35, a main blade 33 and a centrifugal blade 32. The bending directions of the centrifugal blade 32 and the main blade 33 are opposite. The centrifugal blade 32 is located on the back of the rear cover plate of the main impeller 3. A sealing ring 31 is provided on the front and rear covers of the main impeller 3. A vent hole 34 is provided on the rear cover plate of the main impeller 3. A separation chamber 51 is provided below the pump cover 5. An exhaust hole 52 is provided at the bottom of the pump cover 5. The diameter of the exhaust hole 52 is The exhaust hole 52 is connected to the vent hole 34 through the separation chamber 51, and a one-way exhaust valve 6 is connected to the exhaust hole 52. A drainage hole 53 is provided on the top of the pump cover 5, and the drainage hole 53 is connected to the turbine outlet through the infusion pipe 2. The outer contour 41 of the impeller nut 4 is an arc-shaped structure, and the outer contour 41 of the impeller nut 4 has the same curvature as the rear cover plate of the main impeller 3; the outer contour 41 of the impeller nut 4 is designed to be an arc-shaped structure, and such a design is conducive to the gas passing through the vent hole 34. This is because a reverse jet is generated at the center of the outlet of the main impeller 3, which can enable the fluid to push the gas phase to flow out of the vent hole 34.

[0024] Assume that the turbine flow is Q, the air content is α, where 0<α<15%, the radius at the inlet of the main impeller 3 is R1, the radius at the outlet of the main impeller 3 is R2, and the hub radius of the main impeller 3 is R h , the number of main blades 33 on the main impeller 3 is Z1, then the radius of the sealing ring 31 is The sealing rings 31 are arranged at the front and rear to reduce the volume loss on the one hand, and on the other hand to prevent the leakage of fluid from the rear cavity from affecting the centrifugal blades 32, thereby improving the turbine efficiency.

[0025] The outlet angle of the main blade 33 , the component of the absolute velocity at the outlet of the main impeller 3 in the circumferential velocity , where v m2 is the main impeller outlet axial velocity, u2 is the outlet circumferential velocity, v u1 R is the component of the inlet absolute velocity in the circumferential velocity, a is the radius of the intersection of the outlet edge and the centerline of the flow channel; the outlet angle calculated in this way can make the fluid at the main impeller outlet have a certain rotational component, that is, a large-scale spiral vortex and reverse jet are generated at the main impeller outlet, which helps the gas to pass through the vent.

[0026] The inlet width of the rotation increasing blade 35 is , L2 is the width of the main impeller flow channel at the inlet position of the rotation-increasing blade 35, the outlet radius of the rotation-increasing blade 35 is equal to the outlet radius of the main impeller, and the outlet hub radius R of the rotation-increasing blade 35 is h2 =2R hThe axial flow area of ​​the swirl-increasing blade 35 changes evenly from the inlet to the outlet. The wrap angle of the swirl-increasing blade 35 is 0.05~0.15 times the wrap angle of the main blade. The inlet angle of the swirl-increasing blade 35 is The outlet angle β4 of the swirl increasing blade 35 is 70°~90°; the swirl increasing blade 35 enhances the spiral vortex and flow velocity at the outer ring of the main impeller outlet, thereby increasing the back jet intensity of the inner ring, which helps to further improve the efficiency of gas passing through the vent 34.

[0027] The distance from the center of the vent hole 34 to the center of the pump body 1 is , the diameter of the vent hole 34 , where Z3 is the number of vent holes 34, .

[0028] The end surface clearance between the centrifugal blade 32 and the pump cover 5 is 0.3-1.5 mm, and the inner radius of the centrifugal blade 32 is , the outer radius , the number of centrifugal blades 32 is (n=1, 3, 5), the outlet angle of the centrifugal blade 32 is The functions of centrifugal blades are: first, to separate gas and liquid, and second, to transport liquid. The gas and a small amount of liquid passing through the vent hole are subjected to different centrifugal forces due to the difference in gas-liquid density. The gas is transported axially out of the exhaust hole, and the liquid is transported by the centrifugal blades to the drain hole, and then transported to the turbine outlet through the infusion pipe.

[0029] Its working principle is: after the high-pressure liquid flows into the hydraulic turbine inlet, it drives the main impeller 3 to rotate, thereby realizing the conversion of pressure energy into mechanical energy. During the rotation of the main impeller 3, a low-pressure area will be formed at its outlet, which will cause the gas to separate and precipitate from the liquid. At this time, the fluid is affected by the outlet circulation of the main blade 33 on the main impeller 3, generating a spiral vortex and a reverse jet, and the swirl-increasing blade 35 further strengthens the strength of the spiral vortex and the reverse jet, effectively improving the efficiency of the gas passing through the vent 34. Under the synergistic effect of the centrifugal force generated by the rotation of the main impeller 3 and the reverse jet, the gas and a small amount of liquid enter the gas-liquid separation chamber 51 through the vent 34. At the same time, due to the density difference between gas and liquid, the centrifugal force on the gas and liquid phases is different when the centrifugal blade 32 rotates. The liquid is transported to the drainage hole 53 by the centrifugal blade 32, and then transported to the turbine outlet with the help of the infusion pipe 2. The gas and part of the liquid are transported along the axial direction, and finally the gas is discharged from the one-way exhaust valve 6.

[0030] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A gas-liquid separation hydraulic turbine, comprising a pump body, a main impeller and a pump cover, and an impeller nut for fixing the main impeller, characterized in that: The main impeller is composed of a small rotation-increasing blade, a main blade and a centrifugal blade. The bending directions of the centrifugal blade and the main blade are opposite. The centrifugal blade is located on the back of the rear cover of the main impeller. A sealing ring is provided on the front and rear covers of the main impeller. A vent is provided on the rear cover of the main impeller. A separation chamber is provided below the pump cover. An exhaust hole is provided at the bottom of the pump cover. The exhaust hole is connected to the vent through the separation chamber. A one-way exhaust valve is connected to the exhaust hole. A drainage hole is provided on the top of the pump cover. The drainage hole is connected to the turbine outlet through a liquid infusion tube. The outer contour of the impeller nut is an arc-shaped structure, and the outer contour of the impeller nut has the same curvature as the rear cover of the main impeller. Assume that the turbine flow is Q, the air content is α, where 0<α<15%, the radius at the main impeller inlet is R1, the radius at the main impeller outlet is R2, and the hub radius of the main impeller is R h , the number of main blades on the main impeller is Z1, then the radius of the sealing ring is ; The outlet angle of the main blade , the component of the absolute velocity at the main impeller outlet in the circumferential velocity , where v m2 is the main impeller outlet axial velocity, u2 is the outlet circumferential velocity, v u1 R is the component of the inlet absolute velocity in the circumferential velocity, a is the radius of the intersection of the outlet edge and the centerline of the flow channel; The inlet width of the rotation increasing blade , L2 is the width of the main impeller flow channel at the inlet position of the swirl increasing blade, the outlet radius of the swirl increasing blade is equal to the outlet radius of the main impeller, and the outlet hub radius R of the swirl increasing blade is h2 =2R h The axial flow area of ​​the swirl-increasing blade changes evenly from the inlet to the outlet. The wrap angle of the swirl-increasing blade is 0.05~0.15 times the wrap angle of the main blade. , the outlet angle of the rotating blade is β4=70°~90°.

2. A gas-liquid separation hydraulic turbine according to claim 1, characterized in that: The distance from the center of the vent hole to the center of the pump body is , the diameter of the vent hole , where Z3 is the number of vents, .

3. A gas-liquid separation hydraulic turbine according to claim 2, characterized in that: The end surface clearance between the centrifugal blade and the pump cover is 0.3-1.5 mm, and the inner radius of the centrifugal blade is , the outer radius , the number of centrifugal blades is (n=1, 3, 5), the outlet angle of the centrifugal blade is .

4. The gas-liquid separation hydraulic turbine according to claim 1, characterized in that: The diameter of the exhaust hole is .

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