Application of Fully Welded Plate Heat Exchanger in Garbage Incineration System

Application of Fully Welded Plate Heat Exchanger in Garbage Incineration System

Application Scenario

1. Flue Gas Waste Heat Recovery System

Steam Generation: The high temperature flue gas (usually 800 - 1100℃) generated from waste incineration is de-dusted and then heat exchanged with feed water through fully welded plate heat exchanger to heat water to superheated steam, which will drive the turbine to generate electricity or be used for heat supply.

Advantage: the corrugated plate structure of the plate heat exchanger can strengthen the degree of turbulence between the flue gas and water, the heat transfer coefficient is 2 - 3 times higher than that of the traditional tubular heat exchanger, the heat recovery rate can reach more than 70%, and the volume of the steam generator is reduced.

Flue gas cooling: Before the flue gas enters the desulfurization and denitrification equipment, the flue gas temperature is reduced from 300 - 400℃ to 150 - 200℃ through the heat exchanger to avoid the damage of high temperature to the subsequent environmental protection equipment.

2. combustion air preheating

air heating: use the medium temperature flue gas after incineration (200 - 300 ℃) through the fully welded plate heat exchanger to preheat the combustion air, the air temperature from ambient to 150 - 250 ℃, to improve the combustion efficiency of the incinerator, reduce fuel consumption.

Case: After a waste incineration plant adopts fully welded plate air preheater, the combustion air temperature is increased by 180℃, the thermal efficiency of incinerator is increased by 8%, and the annual natural gas saving is about 150,000 cubic meters.

3. Wastewater treatment system

Wastewater heating: when the leachate or other wastewater generated by waste incineration needs to be pre-treated (e.g. anaerobic digestion), the wastewater is heated up to 30 - 50℃ by fully welded plate heat exchanger using steam or flue gas residual heat to optimize the efficiency of microbial treatment.

Cooling water heat transfer: the treated wastewater can be used as cooling water to cool the high temperature equipment in the incineration system (e.g. hydraulic oil, bearings) through the heat exchanger to realize the recycling of water resources.

4. Thermal Conducted Oil System Temperature Control

Thermal Conducted Oil Cooling: In the waste incinerator's thermal oil heating system (used for auxiliary combustion or waste heat utilization), the fully welded plate heat exchanger can cool the high-temperature thermal oil (300 - 350 ℃) to less than 200 ℃ to maintain stable operation of the system.

Heat exchange: heat transfer between thermal oil and steam or water through the heat exchanger, to ensure the efficient conversion of heat energy to the heat end (such as steam generator, heating network).

Case

a 500 tons / day waste incineration plant using fully welded plate heat exchanger flue gas waste heat recovery, the specific configuration is as follows:

Heat exchanger parameters: heat transfer area of 1200 m ², material 2205 duplex steel, flue gas side flow 30000 m ³ / h (1100 ℃ → 200 ℃), the water side flow 150 tons / h (100 ℃ → 3.8MPa saturated steam).

Operation effect: steam production reaches 20 tons / h, power generation efficiency increases by 12%, annual power generation increases by 12 million degrees, while the flue gas emission temperature is controlled at 180 ℃ or less, meeting the requirements of environmental protection.