Combined Cycle Plant Draining Circuit Thermal Recovery

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Solution Overview

Problem

Combined cycle plants for energy production typically dissipate thermal energy associated with drained water, leading to inefficiencies in energy production and increased consumption.

Innovation Solution

The implementation of a draining circuit that recovers thermal energy from tainted water by reducing its pressure to induce rapid evaporation, converting it back into steam and reintegrating it into the steam circuit, thereby increasing the steam flow rate and power production without increasing consumption.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a draining circuit is used to control salt content in evaporators, then water quality is improved, but thermal energy is lost

Engineering Contradiction:
Improvewater qualityVSAvoidthermal energy
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The patent recovers thermal energy from drained water by condensing its vapor in a heat exchanger, thereby recovering the thermal energy that would otherwise be lost while maintaining water quality control through the draining circuit

Inventive Principle:
Principle #34Discarding and recovering

Solution Approach 2:

The patent converts the harmful loss of thermal energy into a beneficial resource by using the heat from condensed vapor to preheat feed water, transforming waste heat into useful thermal energy for the evaporator system

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

2Ease of operation

If thermal energy is dissipated from drained water, then operational simplicity is maintained, but plant efficiency decreases

Engineering Contradiction:
Improveoperational simplicityVSAvoidplant efficiency
Core Design Contradiction:
Ease of operationVSProductivity

Solution Approach 1:

The drained water itself provides the thermal energy for preheating feed water through condensation, making the system self-sufficient in recovering its own waste heat without requiring external energy inputs or complex additional systems

Inventive Principle:
Principle #25Self-service

3Power

If steam flow rate is increased to increase power output, then power production is improved, but energy consumption increases

Engineering Contradiction:
Improvepower outputVSAvoidenergy consumption
Core Design Contradiction:
PowerVSUse of energy by moving object

Solution Approach 1:

The patent changes the temperature parameter of feed water by preheating it with condensed vapor, thereby improving the thermal efficiency of the evaporator and increasing steam flow rate and power output without proportionally increasing energy consumption

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

This approach enhances the efficiency of the combined cycle plant by increasing the power output by approximately 150 kW for a 400 MW plant, reducing specific consumption by 3 kJ/kWh and significantly reducing demineralized water requirements, resulting in substantial cost savings.

Implementation Method 1

reducing its pressure to induce rapid evaporation, converting it back into steam

Methodology Applied
Scientific EffectRapid evaporation: Evaporation

Implementation Method 2

the condenser of the plant

Methodology Applied
Scientific EffectCondensation: Condensation

Data Source

PatentEP2850291B1Combined cycle plant for energy production and method for operating said plant
Publication Date: 2016.09.07 ANSALDO ENERGIA SPA
  • EP2850291B1 patent drawingFigure 1
  • EP2850291B1 patent drawingFigure 2

AI summary

A combined cycle plant (1; 50) for energy production is provided with: a gas turbine unit (2); an operating unit (3); a boiler (4) supplied with exhaust gas from the gas turbine unit (2) and configured to produce steam to be supplied to an operating unit (3); the boiler (4) comprising at least a first evaporator (20) and a first pressure level and at least a second evaporator (24) and a second pressure level lower than the first pressure level; a draining circuit (6; 60) configured to drain the tainted water from the first evaporator (20) and/or from the second evaporator (24); the draining circuit (6; 60) being configured to convert, at least partly, the water drained from the first evaporator (20) and/or from the second evaporator (24) into steam and supply the steam produced directly to the boiler (4) to increase the steam produced by the boiler (4).