COMBINED COMBUSTION OF BIOMASS AND ANTRACITE IN THE STEAM BOILER OF UNIT 300MW

Abstract

In the given article, the technology of industrial production of thermal energy from solid biofuels is considered on the example of modern heat generating equipment and auxiliary equipment. To determine the biomass diversity, an analysis was carried out on potential biomass types, which makes it possible to make a general assessment of feasibility and cost-effectiveness [1]. In the course of the analysis, it was assumed that 50% of available fuel would be used for co-firing in power boilers. This approach serves as a guarantee of the availability of sufficient fuel reserves. In other words, even if the potential for biomass energy use seems to be high at first glance, the feasibility and viability of a project to use biomass energy can only be said if the available biomass reserves in the area of its implementation 3-4 times exceed the level of estimated demand. The important fuel characteristics of biomass used as solid fuel are its calorific value, humidity, ash content and the melting point of ash, which effect on the quality and process of combustion in the boiler chamber and the heating surfaces. As it is known, straw of grain crops has about 800 ℃ melting point of ash, and the ash content of secondary waste of husk and pulp is about fluctuating within 3-4.5%, which is a rather high indicator. Such quality of fuel leads to slagging of the heating surfaces of the boiler, which leads to a further decrease in the coefficient of heat-generating surfaces and accordingly the efficiency of the boiler. Therefore, from the point of view of fuel quality the most rational is the use of wood and corn waste. At the same time, such technology requires the development of a new infrastructure for feeding and fuel-preparation of biofuels. The scheme was developed on the basis of feeding biofuels directly to burners with anthracite, as domestic and foreign experience shows that such schemes work quite successfully. Calculations show that with the co-combustion of corn, you can save from 2 to 14% of funds when burning only one anthracite, as well as saving on burning wood waste - from 5 to 20%, depending on the proportion of anthracite replacement by heat. Calculations were made in percentages of adding biomass from 5,10,15,20 and 25%.