Design and key heating power parameters of a newly-developed household biomass briquette heating boiler

Using biomass briquette fuel for rural household heating is in line with the current Chinese policy and helpful to alleviate the air pollution in winter in northern China. However, the existing biomass briquette boilers have several defects on structure design, fuel feeding, and combustion control, while the design code for the biomass briquette heating boiler has not been proposed thus far. In this study, a newly-developed household biomass briquette heating boiler is designed. Performance test shows that under the optimal operating condition, the emissions of flue dust, NOx, CO, and SO2 are 33.20, 62.48, 426, and 0 mg/m3, respectively; the Ringelman emittance ≤1; the heating power is 12 kW; the thermal efficiency is 84.69%. The tested pollutant emissions and thermal efficiency are in compliance with the limits from the standard. The two key heating power parameters, the grate plan heat release rate and furnace volume heat release rate of this boiler are also determined to provide theoretical basis for the structure design of biomass briquette heating boilers. Results show that the optimal values of these two parameters are 181.98 kW/m2 and 292.04 kW/m3. For the design of household biomass briquette heating boilers, the ranges of 150–210 kW/m2 and 250–330 kW/m3 are considered as the reasonable intervals of these two parameters.