Research of thermotechnical characteristics of domestic boiler with a mechanical pellet burner

Abstract

An experimental study of technologies for direct combustion of pellets in a domestic boiler was conducted. Experimental studies to determine the thermophysical characteristics of the process of burning pellet fuel in the bulk layer were performed using a pellet burner Pelletron-15.To determine the patterns of the process of burning pellets in the burner and the thermal characteristics of the domestic boiler with a pellet burner, studies of the temperature of the boiler volume at different modes of operation of the burner were performed. Temperature measurement was performed using HA-thermocouples with open junction, located in the furnace space at different heights and different distances from the initial cross section of the burner. The analysis of the chemical composition of flue gases, which was determined using a gas analyzer TESTO 330-2LL, namely determined the temperature of the flue gases at the measurement point, as well as the concentration of oxygen (O2), carbon dioxide (CO2), carbon monoxide (CO), nitrogen oxides (NOx) and other parameters.According to the results of experiments, the temperature distribution in the furnace space of the solid fuel boiler Viadrus with a thermal capacity of up to 24 kW with a mechanized burner Pelletron-15 with a pellet feed hopper built into the front panel was determined.In addition, based on the results of some experimental studies, the heat of combustion, humidity and ash content of pellets were determined. The dependences on the time change of the boiler temperature at the stage of quasi-stationary mode of wood pellet combustion are obtained: at the minimum and maximum fuel supply from the hopper, as well as at the maximum fuel supply mode after the supply of additional air from the fan and in the pellet combustion process.The influence of speed and temperature of air introduced into the combustion chamber was determined. According to the research results, measures are proposed to improve the design characteristics of the pellet burner in low-power boilers (10…30 kW).