Evaluation of the thermal efficiency and a cost analysis of a new rice husk gas cookstove for the rural areas of Northern Thailand

Abstract

ABSTRACT The objective of this study was the design and creation of a gas stove that is able to use renewable biomass as an alternative to liquefied petroleum gas. In the research, the representative sample group was located in the rural area of Lampang province of Thailand, It was found by the survey that the average time of cooking the food was 1 hour and a quantity of 1.5 kg of rice husk was used. Following this, the data was analyzed in order to determine the ideal dimensions of the combustion chamber of the rice husk gas stove, which included a height of 60 cm and a diameter of 16 cm. The copper heat exchanger tubes were installed and the air flow rate in the heat exchanger tubes was determined at five levels, which are 0.008, 0.012, 0.016, 0.020, and 0.024 m3s−1. Following this, the rice husk fuel gas test was conducted in order to compare the performance of the rice husk gas stove (RHGS) furnace using the flow rate of the boiling water. It was shown by the results that the optimal air flow rate in a copper tube for the heat exchange area and the reactor of the rice husk gas stove was 0.024 m3s−1, which refers to the RHGS-5. Under this ideal condition, it was determined that the thermal efficiency of RHGS-5 was 34%. It was also found that the levels of emission of pollutants from the rice husk fuel during the burning of the rice husks for the gas stove are suitable for use of the stove in a rural kitchen. Furthermore, the actual payback period of the RHGS-5 was calculated as approximately seven months and 28 days. In addition, the criteria for the design and operational procedures of the rice husk gas stove are also described in this article.