Heat Pipe Heat Exchanger for Waste Heat Recovery in Waste Incineration Plant Flue Gas

Heat Pipe Heat Exchanger for Waste Heat Recovery in Waste Incineration Plant Flue Gas

Heat pipe heat exchangers achieve heat transfer through the phase change of their internal working fluid. In waste incineration plants, high-temperature flue gas passes through the evaporation section of the heat pipe heat exchanger. The working fluid absorbs heat from the flue gas and evaporates into vapor. Under pressure differential, the vapor flows to the condensation section, where it cools and condenses back into liquid, releasing heat. This heat is then transferred to the medium requiring heating, such as air or water, completing the heat recovery process.

Flue gas temperatures emitted from waste incineration plants typically range between 200-600°C, making them suitable for waste heat recovery using heat pipe heat exchangers. These heat exchangers are commonly positioned at the front end of the flue gas purification system, capable of recovering heat from 300-400°C flue gas for applications like preheating combustion air or heating water.

High-Efficiency Heat Transfer: Heat pipe heat exchangers exhibit extremely high thermal conductivity—over 1000 times that of copper. They achieve efficient heat transfer even with low temperature differentials (5-10°C), enabling waste heat recovery rates of 70%-90%.

Safety and Reliability: Independent heat pipe elements completely isolate the flue gas side from the working fluid side. Even if a single heat pipe fails due to corrosion, it prevents flue gas leakage.

Strong Corrosion Resistance: Some heat pipe heat exchangers employ composite phase change heat transfer technology. The wall temperature of the heat pipe remains consistently above the flue gas dew point, effectively controlling dew point corrosion. Additionally, glass-phosphorus flakes are applied to the inner walls of the flue gas ducts, significantly extending the service life of the flue pipes.

Low Maintenance Costs: Each heat pipe operates independently. Localized damage does not affect overall operation, resulting in lower maintenance expenses.