CN108999664B

CN108999664B - Variable-radial-clearance double-inlet turbine box

Info

Publication number: CN108999664B
Application number: CN201810682618.9A
Authority: CN
Inventors: 邢辉; 马超; 李超; 陈化; 王凤利
Original assignee: Dalian Maritime University
Current assignee: Dalian Maritime University
Priority date: 2018-06-27
Filing date: 2018-06-27
Publication date: 2021-06-08
Anticipated expiration: 2038-06-27
Also published as: CN108999664A

Abstract

The invention discloses a variable radial gap double-inlet turbine box, which comprises: the impeller, the left airflow channel, the right airflow channel and the middle partition plate; the left air flow channel and the right air flow channel are arranged side by side left and right in the axial direction of the outer circumference of the turbine impeller inlet, and the middle partition plate is positioned between the left air flow channel and the right air flow channel and arranged on the meridian plane of the turbine box; the axial direction of the middle clapboard is in a circular ring shape, the inner edge is in a circular shape, the outer edge is in a spiral shape, and the radial gap between the inner edge of the middle clapboard and the inlet of the turbine impeller can be gradually increased linearly in the circumferential direction of 0-360 degrees at the vortex tongue. The invention reduces the internal gas leakage of the left gas flow channel and the right gas flow channel of the double-inlet turbine box, is beneficial to reducing the friction loss, increases the cross section flow area of the turbine box, and reduces or does not improve the back pressure generated by the turbine when the engine runs at high speed, thereby reducing the fuel consumption of the engine.

Description

Variable-radial-clearance double-inlet turbine box

Technical Field

The invention relates to the technical field of turbine boxes, in particular to a variable-radial-clearance double-inlet turbine box.

Background

Turbocharging is one of the important ways of utilizing waste heat of an internal combustion engine, and meanwhile, the energy of exhaust gas of the engine is recovered through a turbine to drive a compressor to operate and compress air, so that the pressure and the density of fresh air entering the engine are improved. Thus, the use of a turbocharger can effectively improve the power and efficiency of an internal combustion engine. The development of the high-performance turbocharger can effectively realize energy conservation and emission reduction, and has important practical significance.

The turbocharger consists of a compressor and a turbine, and the outer shell of the turbocharger comprises a compressor volute, a bearing shell and a turbine shell. In order to ensure a continuous supply of exhaust gases and to avoid interference of the exhaust gases of the cylinders, the exhaust pipes of a multi-cylinder internal combustion engine are usually arranged in groups, with the turbine housing of the turbocharger corresponding thereto having a plurality of inlets. A dual inlet turbine box is a relatively common structure that directs exhaust from both inlets to the inlet of the same turbine wheel downstream.

For the double inlet turbine box structure, the gas from the two inlets is separated by the middle partition plate on the meridian plane of the turbine box, and the gas can be supplied to the turbine wheel along the circumferential direction 360 degrees, so that the efficiency of the turbine is high. In the prior art, the radial clearance between the inner edge of the intermediate diaphragm and the inlet of the rotating turbine wheel is constant, i.e. the radial clearance between the inner edge of the intermediate diaphragm and the inlet of the turbine wheel is constant over 360 ° in the circumferential direction.

The exhaust gas discharged by the engine enters from the volute tongue of the double-inlet turbine box and then supplies air to the turbine wheel along the circumferential direction for 360 degrees. Since the two inlets are alternately supplied, the pressure is higher on the side supplied with air than on the other side not supplied with air. Thus, from the volute tongue, the gas at the side having a high pressure flows to the other side having a low pressure through the radial gap δ, and the gas leaks to the exhaust pipe where the gas is not supplied. This reduces the exhaust gas supply to the turbine wheel on the one hand and also disturbs the normal exhaust of the engine part cylinders on the other hand.

Disclosure of Invention

The invention provides a variable-radial-clearance double-inlet turbine box to overcome the technical problems.

The invention relates to a variable radial gap double-inlet turbine box, which comprises:

the impeller, the left airflow channel, the right airflow channel and the middle partition plate;

the left air flow channel and the right air flow channel are arranged side by side left and right in the axial direction of the outer circumference of the turbine impeller inlet, and the middle partition plate is positioned between the left air flow channel and the right air flow channel and arranged on the meridian plane of the turbine box;

the middle partition plate is annular when viewed from the axial direction of the supercharger, and a radial gap between the inner edge of the middle partition plate and the inlet of the turbine impeller can be linearly and gradually increased within the circumferential range of 0-360 degrees at the vortex tongue.

Further, the radial gap can be increased gradually in a non-linear mode within the range of 0-360 degrees in the circumferential direction, and the increasing trend is a curve or a broken line.

Further, in the range of 0-120 degrees in the circumferential direction, the ratio of the radial gap to the radius of the turbine wheel is 5-25%.

Further, in the range of 120-360 degrees in the circumferential direction, the ratio of the radial gap to the radius of the turbine wheel is 20-100%.

The invention reduces the internal leakage of gas in the flow channels at two sides of the variable-radial-clearance double-inlet turbine box, does not increase the exhaust back pressure and reduces the cost of the engine. Meanwhile, the friction loss is reduced, the cross section flow area of the turbine box is increased, and the back pressure generated by the turbine is reduced or not increased when the engine runs at a high speed, so that the fuel consumption of the engine is reduced.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and those skilled in the art can also obtain other drawings according to the drawings without creative efforts.

FIG. 1 is a schematic view of a prior art radial flow turbocharger;

FIG. 2 is a front view of a dual inlet turbine case of the present invention;

FIG. 3 is a schematic view of the internal gas leak-off of a dual inlet turbine case of the present invention;

FIG. 4 is a meridional cross-sectional view of a dual inlet turbine case of the present invention;

FIG. 5 is a schematic view of a parameter of a variable radial gap dual inlet turbine case according to an embodiment of the present invention;

FIG. 6 is a schematic parameter diagram of a variable radial gap dual inlet turbine box according to an embodiment of the present invention;

FIG. 7 is a schematic view of three parameters of an embodiment of a variable radial gap dual inlet turbine case of the present invention;

FIG. 8 is a schematic diagram of four parameters of a variable radial gap dual inlet turbine box according to an embodiment of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The invention provides a variable radial clearance double-inlet turbine box, comprising:

the intermediate diaphragm is annular when viewed from the axial direction of the supercharger, the inner edge is circular, the outer edge is spiral, and the radial gap between the inner edge of the intermediate diaphragm and the inlet of the turbine impeller can be gradually increased linearly within the range of 0-360 degrees in the circumferential direction of the volute tongue.

Specifically, the variable radial clearance double-inlet turbine box of the present embodiment is applied to a radial flow turbocharger of a multi-cylinder internal combustion engine, and as shown in fig. 2, integrally includes: double inlet turbine case 100), bearing housing 200), and compressor volute 300). The double inlet turbine box 100) includes a left gas flow passage 101), a right gas flow passage 102), and a middle partition plate 103). Left air flow passage 101) and right air flow passage 102) are arranged side by side left and right in the axial direction of the outer circumference of the inlet of turbine wheel 104), left air flow passage 101) and right air flow passage 102) being separated by a middle partition 103) arranged at the meridian plane of the turbine case.

As shown in fig. 4, the radial clearance between the inner edge of the diaphragm 103) defining the double inlet turbine box 100) and the inlet of the turbine wheel 104) is δ, defining a circumferential angle of 0 ° at the volute. As shown in fig. 4, the counterclockwise direction is the gas flow direction, and the corresponding circumferential angle θ gradually increases. In conventional designs, δ is constant, i.e., θ is in the range of 0 to 360, and the radial gap δ) is a constant value.

Variable radial gap δ) means that the radial gap δ) between the inner edge of the intermediate bulkhead 103) of the double inlet turbine case 100) and the inlet of the turbine wheel 104) is not constant. Along the gas flowing direction, the circumferential angle theta is within the range of 0-360 degrees, and the radial gap delta) is gradually increased.

The radial clearance refers to the clearance between the inner edge of the middle partition plate of the double-inlet turbine box and the inlet of the turbine wheel, and the radial clearance delta) is constant in the traditional design, namely the radial clearance delta) is a constant value along 360 degrees in the circumferential direction. The variable radial gap delta) means that the radial gap delta) between the inner edge of the middle partition plate of the double-inlet turbine box and the inlet of the turbine wheel is not a constant value. The vortex metering tongue is at a circumferential angle of 0 degree, and the circumferential angle is increased along the gas flowing direction.

The intermediate partition plate 103) is annular when viewed from the axial direction of the supercharger, and has a circular inner edge and a spiral outer edge. Double inlet turbine box 100) has a radial gap δ) between the inner edge of the diaphragm 103) and the inlet of the turbine wheel 104). As shown in fig. 1, a radial-flow turbocharger for a multi-cylinder internal combustion engine of the related art includes a double inlet turbine casing 100, a bearing housing 200, and a compressor volute 300.

As shown in fig. 3, exhaust gas from the engine enters from the volute tongue of the double inlet turbine case and then supplies air to the turbine wheel 360 ° in the circumferential direction. Since the two inlets are alternately supplied, the pressure is higher on the side supplied with air than on the other side not supplied with air. Thus, from the volute tongue, the gas on the side with a high pressure flows to the other side with a low pressure through the radial gap δ), causing the supercharger gas to leak to the exhaust pipe where no gas is supplied in the prior art. This reduces the exhaust gas supply to the turbine wheel on the one hand and also disturbs the normal exhaust of the engine part cylinders on the other hand.

As shown in fig. 5, the circumferential angle θ gradually increases linearly in the range of 0 ° to 360 °.

The circumferential angle theta 1 is 0-120 DEG within the range of 0-theta 1, and the ratio of the dimensionless quantity delta/R radial clearance delta to the radius R of the turbine impeller) can be changed within the range of 5-25%; and the circumferential angle is in the range of 360 ° - θ 1), the ratio of the dimensionless delta/R radial clearance delta to the turbine wheel radius R) may vary in the range of 20% to 100%.

Specifically, as shown in fig. 6, the circumferential angle θ gradually increases in a non-linear manner such that it is convex upward in the range of 0 ° to 360 °.

The circumferential angle theta 1 is 0-120 DEG within the range of 0-theta 1, and the ratio of the dimensionless quantity delta/R radial clearance delta to the radius R of the turbine impeller) can be changed within the range of 5-25%; and the circumferential angle theta is within the range of 360 deg. -theta 1), the ratio of the dimensionless delta/R radial clearance delta to the turbine wheel radius R) may vary within the range of 20% to 100%.

As shown in fig. 7, the circumferential angle θ gradually increases in a concave-down nonlinear manner in the range of 0 ° to 360 °.

As shown in fig. 8, the circumferential angle θ gradually increases in a polygonal line within a range of 0 ° to 360 °.

The circumferential angle theta 1 is 0-120 DEG within the range of 0-theta 1, and the ratio of the dimensionless quantity delta/R radial clearance delta to the radius R of the turbine impeller) can be changed within the range of 5-25%; the circumferential angle theta is 180-360 DEG in the theta 2-360 DEG range, and the ratio of the dimensionless delta/R radial clearance delta to the radius R of the turbine impeller) can be changed in the range of 20-100%; the circumferential angle theta ranges from theta 1 to theta 2, and the dimensionless quantity delta/R can be in linear or nonlinear transition.

The beneficial effects of the embodiments shown in fig. 5 to 8: in the process that the gas flows forwards in the range of 0-360 degrees, the flow rate is continuously increased and the pressure is continuously reduced due to the principles of angular momentum conservation and mass conservation, so that the difficulty of leakage of the waste gas from the gas supply side to the non-gas supply side through the radial gap delta is increased. At this time, the radial gap δ between the lower end of the middle partition plate of the turbine box and the inlet of the turbine wheel is gradually increased, and the radius R of the turbine wheel is unchanged, namely the height L of the middle partition plate of the turbine box is gradually reduced, as shown in fig. 8, even the middle partition plate is finally cancelled, so that the separation effect of the middle partition plate can be improved, the internal gas leakage of the left gas flow channel and the right gas flow channel is reduced, the friction loss is reduced, the cross-sectional flow area of the turbine box is increased, and the back pressure generated by the turbine wheel when the engine runs at a high speed is reduced or not increased, so that the fuel consumption of the engine is.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; while the invention has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A variable radial gap double inlet turbine box, comprising:

the middle clapboard is in a circular ring shape when viewed from the axial direction of the supercharger, and the radial gap between the inner edge of the middle clapboard and the inlet of the turbine impeller is linearly and gradually increased within the circumferential range of 0-360 degrees with the circumferential angle of 0 degree at the vortex tongue; or the increasing trend of the radial clearance in the circumferential direction within the range of 0-360 degrees is a curve or a broken line;

in the range of 0-120 degrees in the circumferential direction, the ratio of the radial gap to the radius of the turbine impeller is 5-25 percent; in the range of 120-360 degrees in the circumferential direction, the ratio of the radial clearance to the radius of the turbine wheel is 20-100%.