Spray Nozzle Design for Steam Desuperheating

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Solution Overview

Problem

Current steam desuperheaters face issues with thermal shock, water buildup, and inefficient temperature control due to improper water spray patterns, leading to hardware damage and maintenance challenges in industrial applications.

Innovation Solution

A novel spray nozzle assembly with a nozzle housing and valve element that creates a uniformly distributed conical spray pattern, featuring a biasing spring protected from thermal shock and debris grooves to prevent sticking, ensuring efficient evaporation and reduced thermal stress.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If cooling water is sprayed into superheated steam to reduce temperature, then the steam temperature is controlled, but thermal shock damages the steam pipe and internal components

Engineering Contradiction:
Improvesteam temperature controlVSAvoidthermal shock damage
Core Design Contradiction:
TemperatureVSObject-affected harmful factors

Solution Approach 1:

The patent applies preliminary action by introducing a thermal liner into the steam pipe before the attemperator nozzle. This liner is pre-installed to protect the steam pipe from thermal shock before the cooling water is sprayed. The liner acts as a protective barrier that absorbs or distributes the thermal shock, preventing damage to the steam pipe while allowing the attemperator to function normally for temperature control.

Inventive Principle:
Principle #10Preliminary action

2Temperature

If spray nozzle is positioned in steam flow for effective cooling, then temperature control is improved, but thermal shock and fatigue cause nozzle failure and sticking

Engineering Contradiction:
Improvesteam temperature controlVSAvoidnozzle assembly reliability
Core Design Contradiction:
TemperatureVSReliability

Solution Approach 1:

The patent applies the taking out principle by extracting the thermal liner from the steam pipe and positioning it downstream of the attemperator nozzle. This separates the protective function (thermal shock absorption) from the cooling function (temperature control). The liner is positioned to protect downstream components from the sprayed cooling water, while the nozzle remains in the steam flow for effective temperature control without being subjected to the same thermal shock.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The thermal liner acts as an intermediary element between the attemperator nozzle and the steam pipe. It mediates the interaction by absorbing or distributing the thermal shock from the cooling water spray, protecting the nozzle assembly and steam pipe from direct thermal exposure. This intermediary protects the nozzle from thermal fatigue and sticking while maintaining effective temperature control.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Productivity

If cooling water is sprayed as fine droplets for uniform mixing, then evaporation efficiency is improved, but water buildup occurs in the steam pipe

Engineering Contradiction:
Improveevaporation efficiencyVSAvoidwater buildup in steam pipe
Core Design Contradiction:
ProductivityVSQuantity of substance

Solution Approach 1:

The patent applies dimensionality change by positioning the thermal liner downstream of the attemperator nozzle, creating a spatial separation between the spray zone and the steam flow continuation. The liner is positioned at a specific distance from the nozzle, allowing fine droplets to evaporate and mix uniformly with the steam in the upstream region, while the liner downstream prevents water buildup by directing the flow or providing a protective surface that prevents accumulation in critical areas.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

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 nozzle assembly effectively reduces thermal shock, enhances evaporation efficiency, and minimizes maintenance by providing a uniform spray pattern and protecting critical components from thermal stress, thereby extending the life of the desuperheater components.

Implementation Method 1

Once the cooling water is sprayed into the flow of superheated steam, the cooling water mixes with the superheated steam and evaporates, drawing thermal energy from the steam and lowering its temperature.

Methodology Applied
Scientific EffectEvaporation: Evaporation

Implementation Method 2

the cooling water mixes with the superheated steam and evaporates, drawing thermal energy from the steam and lowering its temperature

Methodology Applied
Scientific EffectHeat transfer: Convection

Implementation Method 3

the biasing spring is protected from thermal shock by preventing direct exposure to cooling water spray

Methodology Applied
Scientific EffectThermal shock protection: Thermal Shock

Data Source

PatentEP2903729B1Improved nozzle design for high temperature attemperators
Publication Date: 2020.03.04 CONTROL COMPONENTS INC
  • EP2903729B1 patent drawingFigure 1~2
  • EP2903729B1 patent drawingFigure 3~4
  • EP2903729B1 patent drawingFigure 5~6

AI summary

An improved spray nozzle assembly for use in a steam desuperheating device that is adapted to spray cooling water into a flow of superheated steam. The nozzle assembly is of simple construction with relatively few components, and thus requires a minimal amount of maintenance. In addition, the nozzle assembly is specifically configured to, among other things, prevent thermal shock to prescribed internal structural components thereof, to prevent "sticking" of a valve element thereof, and to create a substantially uniformly distributed spray of cooling water for spraying into a flow of superheated steam in order to reduce the temperature of the steam.