Chatchawan Chaichana

Investigation of a Small Biomass Gasifier–engine System Operation and Its Application to Water Pumping in Rural Thailand

This article reports experimental and developmental studies on a producer gas/diesel dual fuel operation of a small engine for irrigation water pumping. In this work, a biomass gasifier–engine system was designed, built, and tested. Waste woods from the furniture-making industry and charcoal were used as feedstock to produce fuel gas in the downdraft, throat-type, fixed-bed gasifier. The engine performance was evaluated over a fixed load and variable speeds between 1,000–2,000 rpm. Results showed that dual operation was able to produce slightly higher power output than normal diesel operation, with similar thermal efficiency. Producer gas substitution or diesel replacement of about 60–70% by mass was achieved. The producer gas powered water pumpset was later installed at a farm in rural Thailand. Start-up was straight forward and continuous operation was achieved with a water yield at 60% of nominal value. It was successfully demonstrated that biomass gasification could provide clean fuel to a small engine and this renewable energy technology could be a sustainable option for water pumping in rural areas.

Comparison of Conventional Flat-Plate Solar Collector and Solar Boosted Heat Pump Using Unglazed Collector for Hot Water Production in Small Slaughterhouse

This study presents simulated results of solar water heating systems in a small slaughterhouse using two techniques. The first one is a normal solar water heating system using a flat-plate solar collector and the second one uses a solar-boosted heat pump system having a corrugated metal sheet roof as a solar collector. The number of solar collector units is between 1 and 5, and the volume of water in a storage tank is 300–1200 L. The heat pump in this work uses refrigerant mixture R22:R124:R152a of 20%:57%:23% as the working fluid. The weather conditions of Chiang Mai, Thailand, are taken as the input data. In the case of the normal solar water heating system, the shortest payback periods for 300, 600, 900, and 1200 L water are 3.63, 3.12, 2.95, and 2.82 yr, respectively. The suitable number of collectors for 300 L water is 1 unit with 600–900 L water storage; 2 units of collectors is suitable in the case of 1200 L water, and 3 units of collectors gives the shortest payback period. However, in the case of a solar heat pump system, the suitable payback periods for 300, 600, 900, and 1200 L water are 2.74, 1.79, 1.83, and 1.88 yr, respectively. In our case, 1 unit of this collector gives the shortest payback period.

Analysis of the biomass gasification-based shape of the crematory's secondary chamber by using Computational Fluid Dynamics

This paper describes the simulation result of biomass gasification-based crematorys secondary combustion chamber via CFD analysis. The chamber models, which were rectangular and cylinder type, were implemented, whereas ANSYS FLUENT with standard k-omega viscous model and SIMPLE algorithm were taken place. The results show that an average residence time of gas and particle if simulating by using rectangular chamber displays as 2 and 3 second, respectively, whereas the average residence time of cylinder chamber type presents 2 second for particle and 4 second for gas. Furthermore, the residence time of cylinder chamber type can be increased by lengthening the chambers height, which the benefits, such as efficient pollution control, will be earned.