Dry Lignite Combustion System with Vapour Separation and Cooling

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Solution Overview

Problem

The operational flexibility of power plants using dry lignite is limited due to the inability to store pulverized dry lignite for start-up, warm-up, and low load stabilization, as it is highly reactive and prone to self-ignition.

Innovation Solution

A combustion system that includes a vapour separation system to separate a fuel-rich stream of pulverized dry lignite from a fuel-lean stream, a cooler to cool the lignite, and a storage silo to store the cooled lignite, allowing for flexible extraction and utilization of the lignite according to operational needs, with valves for regulating flow and preventing self-ignition.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If pulverized dry lignite is stored in a silo for start-up and low load stabilization, then operational flexibility is improved, but the lignite becomes prone to self-ignition due to its high reactivity

Engineering Contradiction:
Improveoperational flexibilityVSAvoidself-ignition risk
Core Design Contradiction:
Adaptability or versatilityVSObject-affected harmful factors

Solution Approach 1:

The lignite is cooled down in advance before being stored in the silo. This preliminary cooling action reduces the temperature of the pulverized lignite to a level where self-ignition cannot occur, while still allowing it to be stored and used later for start-up and low load stabilization operations

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The temperature parameter of the pulverized lignite is changed from a high state (prone to self-ignition) to a low state (safe for storage). By controlling the temperature parameter, the system enables storage of lignite without the harmful effect of self-ignition, thus improving operational flexibility

Inventive Principle:
Principle #35Parameter changes

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 reliable storage and flexible utilization of dry lignite, reducing the need for expensive fossil fuels like oil and gas, and enhancing operational flexibility by ensuring lignite is available when needed.

Implementation Method 1

a cooler (12) to cool the lignite

Methodology Applied
Scientific EffectCooling: Cooling

Implementation Method 2

a vapour separation system (7) to separate a fuel-rich stream of pulverized dry lignite from a fuel-lean stream

Methodology Applied
Scientific EffectCentrifugal separation: Centrifugal Separation

Data Source

PatentEP2993399B1A combustion system and a method for operating a combustion system
Publication Date: 2019.11.27 GENERAL ELECTRIC TECH GMBH
  • EP2993399B1 patent drawingFigure 1

AI summary

The combustion system (1) comprises a furnace (2) with main burners (3), a mill (4) for milling a solid fuel, a vapour separation system (7), a first line (8) for removing a fuel rich stream from the vapour separation system (7) and supply it to the main burners (3), a second line (9) for removing a fuel lean stream from the vapour separation system (7). The combustion system (1) further has a cooler (12) fed by the second line (9) for cooling at least the solid particles and a storage silo (13) connected downstream of the cooler (12), for collecting at least the solid particles cooled at the cooler (12).