Turbocharger Turbine Nozzle Plate Pressure Equalization
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Solution Overview
Problem
The pressure differential between the gap and the suction surfaces of nozzle vanes in turbochargers leads to pressure loss and potential tilting of nozzle vanes, causing friction and inefficiency in turbine operation.
Innovation Solution
Incorporating through holes in the nozzle plate that communicate with the intermediate flow passage and gap, positioned radially outer to the suction surface of the nozzle vanes, to equalize pressures and reduce turbulence-induced pressure loss and vane tilting.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a gap is formed between the plate and the inner circumferential wall part to define the intermediate flow passage, then the nozzle vanes can be arranged to control exhaust gas flow, but a pressure differential occurs between the gap and the suction surfaces of the nozzle vanes causing pressure loss
Solution Approach 1:
A through hole is introduced as an intermediary element connecting the gap and the intermediate flow passage. This through hole acts as a mediator to equalize the pressure between the high-pressure gap region and the low-pressure suction surface region of the nozzle vanes, thereby eliminating the pressure differential that causes energy loss while preserving the flow control function of the nozzle vanes.
Solution Approach 2:
The invention applies pneumatic principles by utilizing the through hole to create pressure equalization between two regions with different pressure levels. The through hole allows exhaust gas to flow from the gap through the plate to the intermediate flow passage, equalizing pressures via gas flow rather than mechanical means, thus reducing pressure loss while maintaining operational effectiveness.
2Productivity
If the pressure differential between the gap and suction surfaces is high, then exhaust gas flow can be directed through the intermediate flow passage, but turbulence is generated causing additional pressure loss
Solution Approach 1:
The through hole is positioned to create a preliminary pressure equalization effect before the exhaust gas reaches the suction surfaces of the nozzle vanes. By establishing pressure balance in advance through the through hole connection, the system prevents the formation of turbulent flow that would otherwise occur due to large pressure differentials, thereby maintaining smooth flow and reducing energy loss.
3Power
If nozzle vanes are arranged in the intermediate flow passage to adjust exhaust gas flow, then turbine performance can be optimized, but friction between nozzle vanes and plate increases due to pressure-induced tilting
Solution Approach 1:
The through hole serves as a pressure equalizing intermediary that eliminates the pressure differential causing nozzle vane tilting. By connecting the gap and intermediate flow passage through the through hole, the system maintains uniform pressure distribution, preventing nozzle vanes from tilting toward the plate and thereby reducing friction loss while preserving turbine power output.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This configuration effectively reduces pressure loss and prevents nozzle vane tilting, thereby enhancing turbine efficiency by equalizing pressures and minimizing friction between the nozzle vanes and the plate.
Implementation Method 1
pressure distribution occurs in a housing, particularly, with a relatively high pressure in a gap between a housing wall surface forming a scroll passage and a plate forming an intermediate flow passage in which the nozzle vanes are arranged, and a low pressure in the vicinity of the suction surfaces of the nozzle vanes. The pressure differential between the gap and the vicinities of the suction surfaces of the nozzle vanes may cause pressure loss in the turbine.
Implementation Method 2
a flow with turbulence from the gap via the outer circumferential edge of the plate to the suction surface of the nozzle vane may be generated. Such flow with turbulence may cause pressure loss.
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
A turbine includes: a turbine impeller; a housing disposed so as to enclose the turbine impeller, and including a scroll passage positioned on an outer circumferential side of the turbine impeller and an inner circumferential wall part defining an inner circumferential boundary of the scroll passage; a plurality of nozzle vanes disposed inside an intermediate flow passage which is positioned, in an exhaust gas flow direction, on a downstream side of the scroll passage and on an upstream side of the turbine impeller; and a plate disposed on a side of the intermediate flow passage with respect to the inner circumferential wall part so as to face the intermediate flow passage such that a gap is formed between the plate and the inner circumferential wall part in an axial direction. The plate has at least one through hole through which the intermediate flow passage and the gap are communicated with each other. The at least one through hole opens to a surface of the plate facing the intermediate flow passage, at a position on a radially outer side with respect to a suction surface of at least one of the plurality of nozzle vanes.