Improving thermal performance of Top-Lit Up-Draft (TLUD) biomass stoves with forced and natural draft systems

Abstract

This research aims to design and improve the thermal performance of three types of TLUD (Top-Lit Up-Draft) biomass stoves: TLUD biomass stoves using a force draft system combined with a choke ring system, TLUD stoves using only a force draft system, and TLUD stoves using only a choke ring system. The study tested different wind directions from the forced draft system into the stove at three angles: 0°, 45°, and 90° relative to the horizontal plane. It was found that a 45° angle used the least amount of time to bring water to boil. The thermal performance of the TLUD biomass stoves was assessed using the Water Boiling Test (WBT) to compare the three types of TLUD stoves. The findings revealed that TLUD stoves employing both the force draft and choke ring systems had the highest thermal efficiency, outperforming those using only the choke ring system or only the force draft system. However, the TLUD stoves using only the choke ring system had higher thermal efficiency than those using only the force draft system. The efficiency metrics were as follows: thermal efficiency (η) was 18.84±0.14%, specific energy consumption (SEC) was 15.47±0.21 MJ/kg, specific cost consumption (SCC) was 0.800±0.011 Baht/kg, burning rate (BR) was 38.27±0.51 g/min, firepower (P) was 9.87±0.13 kW, boiling time (BT) was 10.58±0.49 minutes, and fuel consumption was 2.279±0.049 kg. The developed stove offers advantages in fuel savings, reduced electricity consumption, lower costs for air control equipment, and convenience as it does not require electrical power for the draft system. This makes it suitable for applications requiring high and sustained thermal energy, such as household industrial activities in baking, steaming food, and steam production.