Downhole Turbine Adjustable Shroud Torque Control
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Solution Overview
Problem
Existing downhole turbines in oil and gas operations face challenges in efficiently managing torque and fluid flow due to limitations in variable pitch rotors, which are prone to erosion and can only accommodate a limited range of flow rates without reaching overspeed or stall conditions.
Innovation Solution
An adjustable shroud system is introduced, which axially displaces relative to the rotor to adjust the bypass gap, controlling the proportion of fluid communicated to the rotor and maintaining torque across varying flow rates, coupled with a feedback control system to monitor and adjust the shroud position.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a variable pitch rotor is used to adjust torque, then torque control capability is improved, but device complexity increases and reliability deteriorates due to erosion of moving parts
Solution Approach 1:
The patent extracts the pitch adjustment mechanism from the rotor blades and replaces it with a fixed-pitch rotor combined with an adjustable shroud. The shroud, positioned circumferentially around the rotor, controls fluid flow to the rotor blades without requiring moving parts on the rotor itself, thereby eliminating erosion-prone components while maintaining torque control capability
Solution Approach 2:
The shroud acts as an intermediary component between the fluid source and the rotor. By adjusting the shroud position, the system mediates fluid flow distribution to the rotor, enabling torque control without direct mechanical adjustment of the rotor blades, thus avoiding erosion of critical rotor components
2Adaptability or versatility
If a variable pitch rotor is used to accommodate flow rate variations, then adaptability to flow rate changes is improved, but device complexity increases due to additional moving parts
Solution Approach 1:
The patent implements a dynamic shroud position adjustment mechanism that allows the shroud to move axially relative to the rotor. This dynamic positioning capability enables the system to adapt to varying flow rates by controlling fluid distribution, replacing complex variable pitch mechanisms with a simpler axial movement system
Solution Approach 2:
The adjustable shroud serves multiple functions: it controls fluid flow distribution to the rotor, adjusts torque output, and accommodates a wide range of flow rates. This single component performs what would otherwise require multiple separate mechanisms in a variable pitch rotor system
3Adaptability or versatility
If the shroud axially displaces to adjust bypass gap, then torque control across varying flow rates is improved, but device complexity increases
Solution Approach 1:
The shroud is designed with axial displacement capability, allowing it to dynamically adjust its position relative to the rotor. This dynamic adjustment changes the bypass gap size, controlling fluid flow distribution and maintaining consistent torque across varying flow rates without requiring complex variable pitch mechanisms
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 solution enhances the operational range of the turbine, maintains torque consistency across varying flow rates, and extends the lifespan of the turbine by effectively managing overspeed and stall conditions, thereby improving the efficiency and reliability of downhole operations.
Implementation Method 1
a bypass gap between the rotor and the shroud, the bypass gap communicating a second portion of the fluid therethrough
Implementation Method 2
a first portion of a fluid imparting a torque to the rotor
Data Source
AI summary
A method and apparatus according to which an output of a power generation system is controlled. In one embodiment, the power generation system includes a turbine and a feedback control system. The turbine includes a rotor to which a first portion of a power fluid is communicated, the first portion imparting torque to the rotor; a shaft to which the rotor is connected; a shroud extending circumferentially about the rotor and the shaft; and a bypass gap between the rotor and the shroud, through which a second portion of the power fluid is communicated. The feedback control system axially displaces the shroud relative to the rotor, thereby adjusting the size of the bypass gap and, consequently, the ratio of the first portion relative to the second portion.