Holodilʹnaâ Tehnika i Tehnologiâ (Feb 2019)
System for complex exhaust gas cleaning of internal combustion engine with water-fuel emulsion burning
Abstract
The necessity to fulfill all requirements of international organizations in the field of environmental protection, need to reduce heat loss in combustion of organic fuels, increasing economy and reliability of all elements of ship's power plant make it necessary to develop complex technology. The aim of study is to develop system for complex exhaust gas cleaning of internal combustion engine (ICE). For performing tasks in technology of proposed method, providing solutions to problems of improving economic efficiency, improvement of environmental indicators and reliability, it is envisaged 5 stages of technological process. At all stages conditions for appropriate running of physico-chemical processes in the next stage are created. Possibility of solving complex problems in proposed technology is ensured by combustion of water-fuel emulsion (WFE) with specifically recommended value of water content W r = 30%. When WFE is burnt with a water content of 30%, the low-temperature corrosion intensity decreases, which allows to install a condensing heating surfaces in exhaust gas boilers. At these conditions an equimolar ratio of nitrogen oxides NO2:NO in gases is required, which is necessary to activate their absorption properties. When WFE is burnt with water content W r = 30% the metal surface with a temperature below of dew point H2SO4 passivates. Experimental studies performed show that: 1 m2 of condensing surface absorbs 3.4 mg/m3 of NOx and 0.89 mg/m3 of SO2, which makes it possible to decrease the NOx concentration by 1.55 times and SO2 - in 1.5 times. There is a process of precipitation of toxic solid ash and soot particles: from 150...170 mg/m3 (at outlet of ICE when WFE is burnt with W r = 30%) to 70...90 mg/m3 after the condensing surface. Consumption of water with alkaline properties decreases when NOx, SO2, CO2 concentration is reduced in front of scrubbers. Reducing pollution of heating surfaces increases the cleaning period of EGB in 2.5 times. The using of complex system provides efficient exhaust gas cleaning at the level recommended by IMO.
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