Directions to improve the thermal efficiency of household biomass cookstoves: A review

Abstract

Solid fuel consumption in traditional cookstoves with low efficiency and high polluting performances leads to severe energy waste and atmospheric environment disruption. Improved biomass cookstoves have been recommended to relieve these issues, but the thermal efficiency (TE) of many cookstoves is still needed to improve, for achieving high tiers specified in the standards and significant pollutant emission reduction effect. Therefore, finding out the dominant factors influencing TE and determining their suitable values are essential for further biomass cookstove design and performance improvement. Many studies have focused on part of influencing factors, but few summarized results were presented. This study reviews the literature involving TE performances of biomass cookstoves which were published between 2000 and 2022, and collects the TE evaluation methods and reported TE data for quantitative analysis. The results show that some fuel property parameters (involving fuel type, fuel processing technology, fuel moisture content), cookstove type, air supply mode, and some cookstove geometry parameters (involving combustion chamber height, insulation, pot shield gap, chimney height) are the dominant influencing factors, indicating increasing attention should be paid to them for significant TE improvement. Laboratory test protocol, firepower phase, and operation also have impacts on the TE of biomass cookstoves, but no significance has been found. This review addresses the key parameters related to cookstove TE performance and the corresponding correlations, which helps guide further biomass cookstove design and improvement.