Flow Rate Responsive Turbine Blades Speed Control
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Solution Overview
Problem
Turbine drives in oilfield downhole tools experience excessive rotational speed due to varying fluid flow rates, which can damage consumers of rotary power, necessitating effective speed control mechanisms.
Innovation Solution
A turbine drive assembly with elastic deformation members, comprising front and back elastic elements connected to each turbine blade and a hub, adjusts the trailing edge angle to reduce the tip speed ratio, thereby controlling rotational speed without external energy inputs, using the energy in the flowing fluid.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the turbine blade orientation is fixed, then the turbine structure is simple, but the rotational speed cannot be controlled when fluid flow rate varies
Solution Approach 1:
The turbine blade orientation is made dynamic through elastic deformation members that allow the blades to automatically adjust their pitch angle in response to varying fluid flow rates. This dynamic adjustment controls rotational speed without requiring external control systems, resolving the contradiction between speed control and structural simplicity.
Solution Approach 2:
The elastic deformation members enable the turbine blades to self-adjust their orientation based on the kinetic energy of the flowing fluid. The system uses its own operating conditions (fluid flow) to automatically control rotational speed, eliminating the need for external control mechanisms and maintaining structural simplicity.
2Speed
If the turbine blade pitch is increased to reduce tip speed ratio, then the rotational speed is controlled, but the trailing edge angle changes adversely at high flow rates
Solution Approach 1:
The elastic deformation members are strategically positioned to affect only specific portions of the turbine blades (leading edge or trailing edge). This localized deformation allows precise control of the pitch angle to reduce tip speed ratio while maintaining optimal trailing edge angles for efficient fluid energy extraction, resolving the contradiction between speed control and blade shape integrity.
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
The solution effectively reduces the rate of speed increase with increasing fluid flow rates, maintaining rotational speed within a specified range and preventing excessive speeds, thus protecting rotary power consumers from damage.
Implementation Method 1
the arrangement of the resilient strips results in an automatic pitch increase of the blades with increase of air-screw rotation due to the increasing centrifugal force exerted on the blades
Implementation Method 2
an elastic deformation member which includes a front elastic element and a back elastic element, each of which separately connects to each turbine blade and to the hub, wherein the back elastic element includes a plurality of spokes connected to a ring that attaches to the turbine blades and wherein a deformation of the elastic deformation member changes an orientation of a trailing edge angle of the turbine blades
Data Source
Figure 1A~1B
Figure 2~3
Figure 4~5
AI summary
An apparatus energized by a flowing fluid includes at least one turbine blade having a trailing edge angle and an elastic deformation member connected to the at least one turbine blade. The deformation of the elastic deformation member changes an orientation of a trailing edge angle of the at least one turbine blade.