Numerical optimization and experimental study of a biomass pellet stove

As a key device for low-carbon energy utilization, biomass pellet stoves face the challenge of balancing thermal efficiency and pollutant emissions to meet market access and green heating requirements. Existing studies focus on industrial-scale biomass boilers, leaving significant research gaps in customized modeling and multi-parameter coupling for domestic stoves. To address this, a full-scale CFD–DPM model for a domestic pellet stove with primary and curtain air intakes was developed and validated using a physical experimental platform through three-dimensional temperature field measurements and outlet CO/NOx concentration measurements. The effects of exhaust negative pressure, inlet air temperature, particle size, curtain opening, and relative humidity (RH) on stove thermal efficiency and pollutant emissions were systematically analyzed to meet the Italian 5-star standard. Results confirm good agreement between simulation and experiment. Increasing negative pressure enhances combustion, peaking efficiency at 50 Pa with CO and NOx emissions of 133 ppm and 65 ppm, respectively. An inlet air temperature of 320 K maintains high efficiency (88.5 %) while meeting emission limits. A 6 mm pellet diameter balances efficiency and emissions, while a 5 mm curtain opening optimizes turbulence for minimal pollutants. Increasing RH from 30 % to 90 % lowers efficiency and NOx but raises CO; RH = 50 % achieves 88.65 % efficiency with compliant emissions, which represents the optimal balance. These findings provide quantitative guidance for the precise design and operation of domestic biomass pellet stoves.