Offset Butterfly Valve Layout for Exhaust Heat Leakage Control
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Solution Overview
Problem
Conventional butterfly valve devices in exhaust heat recovery systems face issues with fluid leakage through valve shaft holes, leading to ineffective utilization of exhaust gas heat due to pressure resistance from catalytic converters.
Innovation Solution
The valve device is designed with sealing parts that deviate from the central line of the valve shaft holes, allowing for smooth opening and closing of butterfly valves and preventing fluid leakage by using radial bearings and a pressing component to reduce inertial moment and prevent rattle, ensuring effective heat utilization.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the butterfly valve center is located on the central line of the valve shaft, then the structure is simple and easy to manufacture, but fluid leaks through the clearance between the valve shaft and valve shaft hole, reducing heat utilization efficiency
Solution Approach 1:
The butterfly valve is positioned asymmetrically relative to the valve shaft central line, creating an offset configuration. This asymmetric positioning allows the valve to effectively block the passage between the upstream and downstream sides, preventing exhaust gas leakage through the clearance while maintaining structural simplicity.
2Reliability
If the butterfly valve is offset from the central line of the valve shaft, then fluid leakage is prevented, but the inertial moment increases making the valve harder to operate
Solution Approach 1:
A pressing component is introduced as an intermediary element between the butterfly valve and the valve shaft. This pressing component applies a pressing force to the butterfly valve, ensuring it remains tightly sealed against the valve body during operation. The pressing force counteracts the increased inertial moment, allowing the offset valve to maintain reliable sealing while remaining operable.
3Reliability
If a pressing force is applied to the butterfly valve, then sealing performance is improved, but additional components are required increasing device complexity
Solution Approach 1:
The pressing component is designed to perform multiple functions: it applies pressing force to ensure sealing, provides structural support for the offset butterfly valve, and helps manage the inertial moment during operation. By consolidating these functions into a single component, the overall device complexity is minimized while achieving reliable sealing performance.
Data Source
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AI summary
This valve device is provided with: a body (10) that has at least one passage (11, 12) for passing a fluid and valve shaft holes (13, 14, 15); a valve shaft (20), which is passed through the valve shaft holes so as to rotate freely; and butterfly valves (30, 40), which are fixed on the valve shaft and are for opening and closing the passages (11, 12). The butterfly valves (30, 40) are disposed so as to close the passages (11, 12) on a downstream side or an upstream side of the valve shaft holes (13, 14, 15) in a flow direction of the fluid. As a result, it is possible to prevent fluid leakage and achieve effective utilization of exhaust heat in an exhaust heat recovery system.