Springless Steam Control Valve for High-Pressure Sealing

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Solution Overview

Problem

Piston steam engines face high leakage during cold starts due to the high demands on piston ring seals from superheated steam, and existing control valves with spring elements suffer from thermal changes and wear, leading to unreliable fluid flow regulation at high temperatures and pressures.

Innovation Solution

A springless control valve that uses fluid pressure to actuate the valve body against the valve seat, eliminating the need for a spring element and ensuring reliable closure, with a valve train designed to maintain constant gap width for optimized fluid flow and thermal expansion matching to reduce internal stresses.

Engineering Contradictions & Design Principles

VSEngineering 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 conditions and the valve operating point changes due to thermal expansion

Engineering Contradiction:
Improvevalve closure reliabilityVSAvoidspring element service life
Core Design Contradiction:
ReliabilityVSDuration of action of stationary object

Solution Approach 1:

The patent removes the spring element from the valve mechanism entirely. The closing force is generated by the fluid pressure itself acting on the valve body through a pressure chamber, eliminating the wearable spring component that degrades under high temperature conditions.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The fluid pressure that drives the piston steam engine also serves to close the valve by acting on the valve body through the pressure chamber. The system uses its own operating fluid to provide the closing force, eliminating the need for external spring elements.

Inventive Principle:
Principle #25Self-service

2Reliability

If a spring element is used to apply closing force, then the valve can maintain contact with the valve seat, but repeated actuation results in significant wear of the valve body and valve seat leading to leakage

Engineering Contradiction:
Improvevalve sealingVSAvoidvalve wear resistance
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The spring element is removed from the system. The closing force is provided by fluid pressure acting on the valve body, which eliminates the mechanical wear between the spring and valve components that occurs during repeated actuation cycles.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent uses fluid pressure (pneumatics) to provide the closing force on the valve body. The pressurized fluid acts on the valve body through the pressure chamber to maintain sealing contact with the valve seat, replacing the mechanical spring action with a fluid-based mechanism that reduces wear.

Inventive Principle:
Principle #29Pneumatics and hydraulics

3Reliability

If high spring force is used to ensure valve closure, then the valve remains tightly sealed, but the valve element is pressed into the valve seat with excessive force during cold start

Engineering Contradiction:
Improvevalve sealing forceVSAvoidvalve seat pressure
Core Design Contradiction:
ReliabilityVSStress or pressure

Solution Approach 1:

The closing force parameter is changed from a constant mechanical spring force to a variable fluid pressure force. The fluid pressure in the pressure chamber can be adjusted to provide appropriate closing force at different operating conditions, reducing excessive pressure during cold start while maintaining adequate sealing during operation.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The valve closing mechanism transitions from a static spring force to a dynamic fluid pressure system. The closing force can vary with operating conditions, allowing the system to adapt to different thermal states and reduce impact during cold start while maintaining sealing during normal operation.

Inventive Principle:
Principle #15Dynamics

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 provides reliable and durable valve closure, reduces wear, and maintains efficient fluid flow even at high temperatures and pressures, enhancing the overall performance and efficiency of piston steam engines.

Implementation Method 1

the valve body is subjected to force by a fluid pressure acting on a side of the valve body facing away from the valve seat

Methodology Applied
Scientific EffectFluid pressure: Pressure Increase

Implementation Method 2

a valve train designed to maintain constant gap width for optimized fluid flow and thermal expansion matching to reduce internal stresses

Methodology Applied
Scientific EffectThermal expansion: Thermal Expansion

Data Source

PatentEP4001709A1Spring-free control valve for a piston steam engine, a piston steam engine comprising said control valve, a force heat coupling system comprising the piston steam engine and a method for operating the piston steam engine
Publication Date: 2022.05.25 RD ESTATE GMBH & CO KG
  • EP4001709A1 patent drawingFigure 1
  • EP4001709A1 patent drawingFigure 2
  • EP4001709A1 patent drawingFigure 3

AI summary

The present invention relates to a springless control valve 50 for controlling and/or regulating a fluid flow, in particular a steam flow which preferably has a steam pressure in the range of 10 bar to 180 bar, in a piston steam engine 1, comprising: a valve seat 51, and a valve body 52 which is guided translationally along a central axis CA of the control valve 50 and is configured to be subjected to force against the valve seat 51 in the closing direction S of the control valve 50, wherein the valve body 52 is movable or switchable between an open position in which a fluid can flow, in particular through a valve opening (58) in the valve seat (51), and a closed position in which no fluid can flow, wherein the valve body 52 can be subjected to force against the valve seat 51 by a fluid pressure which is preferably generated or provided by the fluid flow to be controlled and/or regulated.The present invention relates to a piston steam engine 1 comprising the control valve 50, a combined heat and power plant comprising the piston steam engine, and a method for operating the piston steam engine.