Sequence Valve Throttle Segmentation for Downhole Tractor
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing sequence valves in hydraulic systems require high-energy throttles to withstand pressures up to 200 bar, leading to narrow throttles that easily clog and are inefficient in starting pumps at low energy consumption.
Innovation Solution
A sequence valve design with a pressure-controlled sliding part and a return spring, featuring a third cavity connected to the pump on the opposite side of the spring, with the second and third cavities connected via a short, viscosity-independent flow channel throttle, allowing slow pump startup and efficient energy consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stress or pressure
If a narrow throttle is used to withstand high pressure (200 bar), then the throttle can handle the pressure requirement, but the throttle easily clogs up and is inefficient
Solution Approach 1:
The invention divides the single throttle function into two separate throttles: a first throttle connecting the pump to the second cavity, and a second throttle connecting the second cavity to the third cavity. This segmentation allows each throttle to operate at lower pressure differentials, enabling wider opening dimensions that resist clogging while still handling the required 200 bar system pressure.
Solution Approach 2:
The second cavity acts as an intermediary chamber between the pump and the third cavity. Fluid from the pump passes through the first throttle into the second cavity, then through the second throttle into the third cavity. This intermediary structure distributes the pressure drop across two stages, allowing both throttles to have larger flow areas that are less prone to clogging.
2Stress or pressure
If a narrow throttle is used to withstand high pressure, then the pressure requirement is met, but energy consumption increases
Solution Approach 1:
By segmenting the throttle function into two separate throttles in series, the pressure differential across each throttle is reduced. This allows for more efficient fluid flow through each throttle with lower pressure losses, reducing the overall energy consumption of the hydraulic system while maintaining the required 200 bar output pressure.
Solution Approach 2:
The invention changes the flow parameters by introducing an intermediate cavity that divides the pressure drop into two stages. This parameter change allows each throttle to operate at more efficient flow conditions with lower velocity heads and reduced turbulence losses, thereby decreasing the power consumption of the pump.
3Speed
If the pump starts quickly, then the system responds faster, but the engine requires high energy consumption to start
Solution Approach 1:
The two-throttle arrangement with the intermediate second cavity enables preliminary gradual pressurization of the system. During startup, fluid flows through both throttles in sequence, providing a controlled, progressive pressure build-up that allows the engine to start with lower energy consumption while still achieving the required system pressure for operational speed.
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
Enables the pump and engine to start at low energy consumption, reducing power usage and preventing throttle clogging by maintaining fluid flow independence from viscosity, effectively closing the tank connection as pressure builds.
Implementation Method 1
a pressure-controlled sliding part with a return spring
Implementation Method 2
the second cavity is adapted to be connected with a pump via a throttle
Implementation Method 3
in a second, pressurised position closes off the connection with the tank
Data Source
Figure 1
Figure 2
AI summary
The invention relates to a sequence valve for use in a hydraulic plant, which sequence valve has a pressure-controlled slide valve (5) with a spring return and in a starting position defines a first cavity (10), which cavity is connected with a tank and the hydraulic plant, and in a second, pressurised position closes off the connection with the tank. The cavity is connected to a second cavity (18) via a channel (15, 16, 17) in the slide valve, and the second cavity is adapted to be connected with a pump via a throttle (20) and is positioned on the same side of the slide valve as the spring (7). The sequence valve has a third cavity (19), which is adapted to be connected with the pump and is positioned on the opposite side of the slide valve from the spring, and the second and the third cavity are connected with each other via a fixed throttle with a short flow channel. The invention also relates to downhole tractor with the sequence valve.