Heat Recovery Equipment Using Condensed Water for Corrosion Prevention
Solution Overview
Problem
Conventional heat recovery equipment from coal burning boilers is inefficient in utilizing heat, prone to corrosion, and has a short tube durability due to the use of steel balls for soot removal, which affects power generation efficiency and reliability.
Innovation Solution
The proposed heat recovery equipment includes a power generation plant with a condensed water line and an exhaust-gas treatment line featuring a heat extractor unit, a dry electrostatic precipitator, and supplementary air preheaters, which recover heat from flue gas and use condensed water as a heat medium to reduce flue gas temperature, prevent corrosion, and improve particulate matter removal efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If steel balls are constantly dropped to remove soot from heat extractor tubes, then soot removal effectiveness is improved, but tube durability deteriorates
Solution Approach 1:
The patent replaces the mechanical soot removal system (steel balls dropping) with a thermal field system. The heat extractor unit uses condensed water to cool the flue gas and condense sulfur trioxide, forming a protective film on the tube surfaces that prevents soot adhesion. This eliminates the need for mechanical cleaning and extends tube durability.
Solution Approach 2:
The patent introduces condensed water as an intermediary substance. The condensed water cools the flue gas and forms a protective layer on the tube surfaces, preventing direct contact between soot and the tube material. This intermediary mechanism replaces the direct mechanical cleaning approach and reduces wear on the tubes.
2Use of energy by moving object
If heat recovery is intensified to improve power generation efficiency, then energy utilization is improved, but corrosion risk increases
Solution Approach 1:
The patent converts the harmful effect of condensed water (which could cause corrosion) into a beneficial protective mechanism. The condensed water forms a protective film on the tube surfaces that prevents sulfur trioxide from contacting and corroding the metal. By controlling the condensation process and using the condensed water as a protective barrier, the system intensifies heat recovery while preventing corrosion.
Solution Approach 2:
The patent changes the temperature parameter of the flue gas by introducing condensed water for cooling. This temperature reduction enables more intensive heat recovery in subsequent stages while the controlled condensation process creates a protective environment that prevents corrosion. The parameter change transforms a potentially harmful condition into a beneficial one.
3Loss of energy
If flue gas temperature is reduced to improve heat recovery, then energy efficiency is improved, but particulate matter removal efficiency deteriorates
Solution Approach 1:
The patent segments the heat recovery and particulate matter removal processes into distinct stages. First, condensed water cools the flue gas and removes sulfur trioxide. Then, the cooled flue gas passes through a dry electrostatic precipitator for particulate matter removal. This segmentation allows temperature reduction for heat recovery while maintaining effective particulate matter removal through the specialized precipitator design.
Solution Approach 2:
The patent uses the dry electrostatic precipitator as an intermediary device between the cooling stage and the final flue gas discharge. The precipitator is specifically designed to handle the temperature and composition characteristics of the cooled flue gas, ensuring effective particulate matter removal even at reduced temperatures. This intermediary device bridges the gap between heat recovery requirements and particulate matter removal 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
This configuration enhances heat recovery efficiency, increases power generation output, reduces particulate matter and sulfur oxide concentrations, and extends the life of equipment components by preventing corrosion and improving the durability of the heat extractor unit.
Implementation Method 1
the heat extractor unit recovers heat from the flue gas, and the condensed water heater heats water condensed by the condenser with the heat recovered by the heat extractor unit
Implementation Method 2
a condensed water line, the condensed water line including a condenser
Implementation Method 3
a dry electrostatic precipitator (ESP) 4. The dry ESP 4 removes a substantial amount of particulate matter from the flue gas A1
Implementation Method 4
a power generation plant that drives a steam turbine by superheated steam produced in a boiler
Implementation Method 5
a coal burning boiler 1
Data Source
AI summary
Heat recovery equipment recovers heat from flue gas. The heat recovery equipment includes a power generation plant that drives a steam turbine by superheated steam produced in a boiler, and an exhaust-gas treatment line that treats flue gas output from the boiler. The exhaust-gas treatment line includes a first air preheater, a heat extractor unit, and a dry electrostatic precipitator. The power generation plant includes a condensed water line. The condensed water line includes a condenser, a condensed water heater, and a low-pressure feedwater heater. The condensed water heater heats water condensed by the condenser with the heat recovered by the heat extractor unit.