Method in the operation of a firing plant, and a firing plant for performing the method

Abstract

In a method in the operation of a firing plant of the type comprising a combustion furnace and heat exchanger means to transfer thermal energy from the flue gas of the furnace to its combustion air, wherein a vaporizable liquid, such as water, is added to the combustion air of the furnace, the combustion air pressure is reduced in the portion of the heat exchanger means where the said liquid is caused to evaporate, the necessary evaporation heat being taken from the flue gas of the furnace before the flue gas is discharged to the atmosphere. A plant for performing the method is characterized by containing a pump (11) which has a relatively small inlet opening (10) so that the pump (11) creates a negative pressure in the portion (12) of the heat exchanger (9) where the liquid, fed by means of a nozzle (13), evaporates. This allows large amounts of water to evaporate, and flue gas, which flows through the heat exchanger portion (14), is cooled to a low temperature. The flue gas will then condense, and this procedure is accelerated by the constriction (at 16) of the flue (15) so that there is a positive pressure in the heat exchanger portion (14). According to the heat pump principle, the advantages are an unprecented low temperature level and humidity content of the discharged flue gas and a correspondingly high efficiency of the firing plant.

Dependencies are inferred from the claim text.