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Equipment – Flue gas condensing economizers

Flue gas condensing economizers

Horizontal flue gas condensing economizer

Vertical flue gas condensing economizer

Horizontal flue gas condensing economizer

Flue gas condensing economizer (FGC) is designed to recover thermal energy by condensing water vapor from flue gas. Heat and mass transfer take place inside the FGC whereabouts flue gas is being sprayed directly with a huge amount of condensate. The unit is designed to work with biomass boilers. The amount of heat recovered by the flue gas condensing economizer depends on the external conditions. The main ones are: • Thermal capacity of biomass boiler - MW; • Biomass moisture; • Temperatures of heating water supplied to the flue gas condensing economizer. In the flue gas condensing economizer it is possible to recover about 15% - 30% of thermal energy from the boiler power.

Working principle

The flue gas entering the condensing economizer travels through two U-shaped channels, where nozzles are arranged to disperse condensate into the flue gas stream. The injected droplets are at a lower temperature than the flue gas, so they begin to absorb the thermal energy contained in the flue gasses during the heat and mass transfer process. Since the fuel is first dried in the combustion chamber (furnace, combustion stage I), a large amount of water is vaporized into flue gasses. Water vapor starts to condense as the flue gas temperature in the condenser reaches the dew point value. The formed condensate is collected and circulated through the heat exchanger (s). After condensate is cooled down, repeatedly sprayed into the flue gas flow.

The flue gasses in the unit can be cooled from 180 ° C to 45˚C ÷ 65˚C depending on the humidity of the fuel (as the humidity of the fuel increases, the efficiency of the condenser increases).

Vertical flue gas condensing economizer

The flue gas condensing economizer is designed to recover thermal energy. Heat exchange takes place in the pipe heat exchanger of the flue gas condensing economizer for the combustion products and condensed condensate from water vapor in direct contact with the cogeneration water. The unit is designed to work with biomass boilers. The amount of heat recovered by the flue gas condensing economizer depends on the external conditions. The main ones are: • Thermal capacity of biomass boiler - MW; • Biomass moisture; • Temperatures of heating water supplied to the flue gas condensing economizer. In the flue gas condensing economizer it is possible to recover about 15% - 30% of thermal energy from the boiler power.

Working principle

In the flue gas condensing economizer (DKE) tubular heat exchanger, the smoke flows inside the pipes and the cogeneration water flows outside the pipes (flows through the pipes). Flue gasses enter the DKE from above and exits from below. Due to the partitions inside the unit, the cogeneration water flows in a horizontal direction and thus flows through the pipes. The smoke in the unit can be cooled from 180 ° C to 45˚C ÷ 65˚C. Inside the heat exchanger, the district heating water heats up on the principle of heat exchange. In the flue gas condensing economizer (DKE) it is possible to recover about 15% - 30% of thermal energy from the boiler power.

Horizontal and vertical flue gas condensing economizers in action !