ENERGY EXERGY ANALYSIS OF SOLAR CHIMNEY DRYING SYSTEM

Abstract

Experimental setup was situated on the rooftop of the Delhi Technological University (DTU), Delhi, India (28.750 N, 77.110 E). SCPP converts solar energy into electricity. In this thesis work, the effect of convective heat transfer coefficient, heat loss factor, heat utilization factor, diffusivity coefficient and instantaneous thermal loss efficiency factor, the design and experimental analysis of system with traditional cylindrical SCPP with solar dryer under the condition of natural convection in passive mode was carried out on hourly basis from 08:00 hours to 18:00 hours. The approach of exergy analysis is also investigating the thermodynamic understanding of the SCPP. Day 1 and day 2 were clear sky, while day 3 was cloudy. And the tests were carried out only in barren conditions of the ground. The convective heat transfer coefficient ranges from 1.29 W/m2 0C to 2.60 W/m2 0C. The HUF ranges from 0.08 – 0.57 and COP ranges from 0.42 – 0.91. The exergetic efficiency of drying system under passive mode ranges from 23.49% – 92.74%. Heat loss factor value varies from 3.93 watts – 51.93 watts and the variation of coefficient of diffusivity value is from 0.003130 to 0.003172. The characteristic equation has been used for experimental results of solar drying system under passive mode to generate linear characteristic equation for clear sky condition. The instantaneous indirect loss efficiency curve have also been analyzed which shows the degree of effectiveness of the system. Also the experimental uncertainty analysis for ambient and ground temperature is calculated as 0.38% and 0.40% respectively which comes out to be within the permissible limit. The maximum temperature attained was 64.20C hence solar dryer can be recommended for drying corn, maize, paddy, pulses, tice, wheat, brinjal, cabbage, garlic, onion, tomatoes.