Finned-tube Radiator Recovery of Waste Incinerator Flue Gas To Produce Steam for Power Generation Or Heating

Finned-tube radiator recovery of waste incinerator flue gas to produce steam for power generation or heating

Flue gas from waste incinerators reaches extremely high temperatures (typically 850°C - 1050°C), carrying substantial thermal energy. The core of this system utilizes a waste heat boiler composed of finned-tube heat exchangers to recover heat from the flue gas and produce steam. This steam serves two primary purposes:

Power Generation: Driving steam turbine generators to convert thermal energy into electricity.

Heat Supply: Directly serving as a heat source for industrial or domestic applications.

Waste incineration flue gas is a quintessential “high-temperature, highly corrosive, and dust-laden” medium. The selection of finned tubes is based on their unparalleled advantages:

High Efficiency & Compactness: Low heat transfer coefficients on the flue gas side are significantly enhanced by fins, which greatly increase the heat transfer area. This enables a compact boiler structure capable of recovering substantial heat within limited space.

Cost-Effectiveness: Compared to using bare tubes alone, finned tubes save significant metal material while achieving equivalent evaporation capacity, thereby reducing manufacturing costs.

Flexibility: Different finned tube materials and types can be flexibly selected based on the temperature and corrosion characteristics of various flue gas zones.

A complete waste incineration waste heat boiler typically includes the following heat transfer surfaces, where finned tubes are selectively applied:

Furnace water-cooled walls: Absorb radiant heat; typically solid-tube membrane walls without finned tubes.

Superheater: Heats saturated steam to superheated steam. This section experiences the highest temperatures and most severe corrosion, typically employing wide-spaced spiral finned tubes or plain tubes made from the highest grade corrosion-resistant materials.

Evaporator: Heats water to saturated steam. Depending on the flue gas temperature zone, finned tubes may be extensively used to enhance heat transfer, though ash removal and corrosion issues require careful consideration.

Economizer: Preheats boiler feedwater using flue gas from the boiler tail section. This section experiences the lowest temperatures and the highest risk of acid dew point corrosion. Fin tubes (helical or H-type) are widely used to maximize waste heat recovery, and materials must be corrosion-resistant.