Adapting television satellite dish for low-temperature solar thermal application: Experimental evaluation

Abstract

Digital television broadcasting is currently becoming popular and as a result, the purchase of television cable dishes and other accessories are on the rise. Abandoned television satellite dishes continue to litter our environment due to obsolescence. Finding alternative use stands as a control measure for this inevitable environmental degradation. This paper, therefore, investigates the adaptation for low temperature solar thermal application. The TV satellite dish selected for this study has a diameter of 33.9 cm, depth of 9 cm and a focal point of 31.2 cm. The components added to the dish include; a reflective surface, pot stand, adjustable chain, dish support stand and base, control arm. This system was used in carrying out stagnation test on three different types of pots (aluminium, iron and stainless steel pots) positioned at the focal point. Other performance parameters studied include; standard stagnation temperature (SST) and the rate of change of pot temperature. The maximum stagnation temperatures attained by the inside of the iron, aluminium and stainless steel pots were 68, 80 and 82 °C respectively after 10, 13 and 40 minutes respectively; while their respective maximum SST were 100, 57 and 50 o C. The maximum temperature change inside the iron, aluminium and stainless steel pots were above 9, 12 and 10 o C/min. The result gathered shows that this system will be suitable for lower temperature applications like pasteurization, sterilization, household water heating, etc.