Springless Control Valve Thermal Stress Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Piston steam engines face high thermal stress and leakage issues due to the use of spring-based control valves, which are exacerbated by high temperatures and pressures, leading to wear and malfunctions.
Innovation Solution
A springless control valve design that utilizes fluid pressure to actuate the valve body against the valve seat, eliminating the need for a spring element and minimizing thermal stress, with a valve train geometry that maintains a constant gap width for optimal fluid flow and a clamping system that matches thermal expansion to reduce internal stresses.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a spring element is used to apply closing force to the valve body, then the valve can be automatically closed in the unactuated state, but the spring element wears out quickly under high temperature and pressure conditions, leading to valve leakage and malfunction
Solution Approach 1:
The patent removes the spring element from the valve system entirely, extracting the problematic component that caused wear and reliability issues. The closing force is instead provided by the valve train mechanism itself, which is more durable under high temperature and pressure conditions.
Solution Approach 2:
The patent replaces the spring-based mechanical closing mechanism with a valve train-based closing mechanism. The valve train, actuated by the piston, provides the closing force without requiring a spring element, thereby eliminating the wear and reliability problems associated with springs in high-temperature environments.
2Reliability
If a spring element is used to provide closing force, then the valve can maintain sealing, but thermal changes cause the spring characteristic to change greatly over the high temperature range, leading to valve malfunction
Solution Approach 1:
The spring element is removed from the system, eliminating the source of thermal instability. The valve train mechanism provides closing force that is not affected by thermal changes in the same way springs are, maintaining consistent valve performance across the operating temperature range.
Solution Approach 2:
The patent changes the fundamental parameter of how closing force is generated - from spring elasticity (which is highly temperature-dependent) to mechanical force transmission through the valve train (which is more thermally stable). This parameter change eliminates the problematic temperature characteristic variation.
3Productivity
If high steam pressure (40 bar to 150 bar) is used to operate the piston steam engine efficiently, then power generation efficiency is improved, but leakage occurs during cold start due to high demands on the piston ring seal
Solution Approach 1:
The valve train mechanism provides its own closing force through the piston's mechanical action, eliminating the need for separate spring elements that would add complexity. This self-contained mechanism ensures reliable sealing during cold start without compromising the high steam pressure operation needed for efficiency.
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 ensures reliable and permanent sealing, reduces wear, and maintains efficient fluid flow even under extreme conditions, allowing operation at high temperatures and pressures without the need for additional valve drives, thus enhancing the performance and longevity of piston steam engines.
Implementation Method 1
The valve body (52) is actuated by a fluid pressure which is preferably generated by the fluid flow to be controlled and/or regulated
Implementation Method 2
a clamping system that matches thermal expansion to reduce internal stresses
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The present invention relates to a control valve 50, in particular a springless control valve, for controlling and/or regulating a fluid flow, in particular a steam flow which preferably has a steam pressure in the range of 40 bar to 150 bar, in a piston steam engine 1, comprising: at least one supply line 59 which is configured to supply a piston steam engine 1 with a fluid, in particular a working fluid, a valve seat 51, a valve body 52 which is translationally movable along a central axis CA of the control valve 50 and is configured to be movable or switchable between an open position and a closed position, and a valve train 54 with a longitudinal axis LA which is configured to interact with the valve body 52 in a force-transmitting manner in order to lift the valve body 54 from the valve seat 51 to open the control valve 50.wherein the valve train has a bearing surface at one end facing the valve seat 51 and a threaded section at one end facing away from the valve seat 51, and the valve train 54 can be screwed or inserted into a piston 30 of the piston steam engine 1 by means of a clamping nut 66, which preferably interacts with the threaded section, such that a clamping length L4 of the valve train 54 is designed such that a thermal expansion of the clamping area corresponds approximately to a thermal expansion of the piston base 30B with the piston base thickness L2, into which the valve train 54 can be screwed or inserted or is integrated.