Solar/biomass/rock-bed storage for continuous drying | |
| Author | Rut Korsakul |
| Call Number | AIT Thesis no.ET-06-4 |
| Subject(s) | Drying Heat storage--Simulation methods Solar heating Biomas gasification Solar food dryers |
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering, School of Environment, Resources and Development |
| Publisher | Asian Institute of Technology |
| Abstract | A study of the performance of a solar/biomass/rock bed storage for continuous drying was carried out wherein the theoretical performance of the system components were investigated by simulating the behaviour of the system components through the TRNSYS simulation software and equation models. The optimum operating conditions of system components were selected based on the performances analysis of the simulation results. The optimum airflow rates through a solar collector, rock bed storage unit and cross flow heat exchanger were set based on the simulation results to conduct the experiments. The performances of each component and the overall system performances were ascertained from the simulation results, which was able to predict the measured results. The optimum strategies to operate solar collector, gasifier stove and rock bed storage together for continuous supply hot air to drying application were found for sunny, partly cloudy and cloudy days. 4 m' solar collector could generate temperature of hot air at collector outlet in the range of 50 -70°C (average of 54.7°C) at an air flow rate of 180 m' /hr during 9:00 am - 15:00 pm. Energy analyses revealed that it is better to generate hot air and directly supply to drying application. More loss occurs if it is charged to rock bed and less useful energy can be withdrawn. Rock bed storage unit, charging at 220 m3/hr and discharging at 90 m3/hr can result of higher amount of heat being charged and supplied to drying application for longer period of times. The bed is charged by hot air generated by gasifier stove for 6 hours at the average temperature of 110.7 °C. Then, it can be discharged for 9 hours and supplied to drying application in the range temperature of 50 70°C (average of 55.6°C). Furthermore, when the hot air generated from gasifier stove is directly supplied to drying application the supply temperature is high (around 64.2°C on an average) at the flow rate of 360 m'/hr. Total heat supplied from the system to drying application on sunny, partly cloudy, and cloudy days is around 121.1. 62.6 and 92.1 MJ at the rate of 8.1, 7 and 13.8 x-1.1/hr, respectively. The supply airflow rate ranges from 90 to 380 m'/hr depending on the operation. The overall system efficiency is the highest when less components are used during the generating and supplying energy processes. The overall system efficiency when all system components are used is maximum at 3.71%, while on the days there is no sun it is around 14.4% when the gasifier stove supplies heat directly to the drying application |
| Year | 2006 |
| Type | Thesis |
| School | School of Environment, Resources, and Development (SERD) |
| Department | Department of Energy and Climate Change (Former title: Department of Energy, Environment, and Climate Change (DEECC)) |
| Academic Program/FoS | Energy Technology (ET) |
| Chairperson(s) | Kumar, S.; |
| Examination Committee(s) | Surapong Chirarattananon ;Dutta, Animesh; |
| Scholarship Donor(s) | Royal Thai Government Fellowship; |
| Degree | Thesis (M.Eng.) - Asian Institute of Technology, 2006 |