RESEARCH OF BURNING OF AGRICULTURAL PELLETS IN BOILERS WITH CAPACITY UP TO 25 kW

Abstract

The main purpose of this research is to determine the main dependence’s of the agricultural pellets combustion process and to study the influence of regime parameters on the distribution of temperatures in the combustion chamber, as well as to analyze the biofuels productivity characteristics. Research methods: experimental and theoretical. Results. The research of biofuel combustion process was carried out at the experimental facility of solid fuel boiler with a pellet burner for a passive type house heating. During experimental researches samples of wood pellets, rapeseed pellets and beets pulp were used. On the received graphs the changes in the temperature state of the combustion chamber at the stage of pelletʼs ignition, burning and fading were reflected. It was found that the largest increase in temperature occurs near the wall of the boiler, which is opposite to the burner. As can be seen on the graphs, temperature fluctuations occur as a result of the periodic burning of biofuel in the burner and the arrival of a new portion of pellet from the hopper. As the experiments showed, the temperature level at burning of rapeseed pellets is much lower than in comparison with wood pellets, and to go to the established mode of burning of beet pulp pellets is generally problematic. It is obvious that when setting up the fuel supply system and modes of operation of the fuel it is necessary to take into account heat physical characteristics of fuel, first of all moisture and heat capacity, as well as yield of volatile combustible components. For this purpose, a gas analysis was carried out when burning wood pellets. The selection of combustion products was done in the wild immediately after the boiler. As a result, the NOx and CO concentrations of the appropriate temperature were obtained at the sample site. The nitrogen oxide concentrations should be considered moderate, which cannot be argued about the concentration of carbon monoxide, which requires further research. The obtained results can be used to increase the efficiency of combustion process at burning biofuel in boilers of low power communal and industrial heat power, social-budget sphere and individual-household sector.