N. S. Rathore

Environment friendly biomass gasifier cookstove for community cooking

Traditional community cookstoves have a low level of efficiency due to their poor heat transfer efficiency and incomplete combustion. The low efficiency results in a high consumption of fuel wood, thereby creating a need of more fuel wood. This paper deals with the development of a biomass cookstove suitable for community cooking. The stove exhibits approximately 36.38% thermal efficiency and has a thermal power rating of 5 kW. The maximum flame temperature recorded was 712°C. The data indicate that the developed cookstove can save approximately 7155 kg of CO2 per annum.

Performance evaluation of solar tunnel dryer for grape drying

This paper presents the performance of solar tunnel dryer to dry chemically untreated grape. Average air temperature rise in dryer was in the range of 20–21°C above the ambient temperature and it was almost constant in the dryer. The solar tunnel dryer of size 10 × 3.75 m 2 is in position to dry 320 kg of grapes from 85% (wb) moisture content to 16% (wb) moisture content within seven days. Developed solar dryer works at temperature between 55–70°C, therefore, there is scope for saving conventional fuel by adoption of solar energy-based drying operation.

Design and Development of Paraboloid Solar Concentrator for Milk Pasteurization

Solar energy is the one of the major sources of energy which is renewable inexhaustible, clean and can significantly contribute the world energy requirement with available conversion technology. The research work was undertaken to design and development of paraboloid solar concentrator for milk pasteurization of 10 lit in one batch capacity at department of Renewable Energy Sources, CTAE, Udaipur. The collector of paraboloid concentrator was 1.08 m in diameter with focal length of 0.28 m. The performance evaluation of the system and techno-economic was evaluated. The performance of paraboloid solar concentrator was evaluated for two conditions i.e. no load and full load. During no load testing maximum temperature achieved in the system was 174 C. The full load performance of the system was evaluated with cow milk. The time required for milk pasteurization was 85 min for 10 lit batch capacity. During the full load testing, once the production of steam started, the increase in temperature is almost constant and it varies approximately 3 C every 5 min. The difference in temperature is about 10 C. Water heating and cooling tests are performed to evaluate the performance of the paraboloid concentrator in terms of overall heat loss factor (F’UL) and optical efficiency factor (F’no). The overall heat loss factor was found to be 23.53 and 22.03 W/m2 K for different tests in the month of March. The optical efficiency factor (F’no) was worked out to be 0.327 and 0.330 for the same tests. The optical efficiency of the system was found to be 32.70 and 33.0 per cent. The thermal efficiency of the paraboloid solar concentrator system was determined. The observed thermal efficiency of the system was 32.65 and 32.96 per cent for average solar insolation of 558 and 586 W/m2 respectively. The cost of the system was found to be Rs. 4431/- with 1.10 benefit to cost ratio. The cost could be recovered within the period of 0.54 years.