Answer Happy

Question 1 A building in Brighton has been fitted with a solar collector with glazing measuring 4m2 for provision of hot water to supplement domestic hot water services. The collector performance chart provided by manufacturer defining collector efficiency n against a heat loss parameter (t; --a)/I,, reveals following information: y intercept=0.80 and slope=5 downwards. (a) Sketch and label the graph of (t; -t) I, against collector efficiency n and determine the solar collector efficiency, if the water inlet temperature tis 35 °C, the ambient temperature t, is 20 °C and the solar irradiance I, is 1000 W.m2 (30%) (b) If the solar collector efficiency is 0.5 and the solar irradiance is 800 W/m², determine the followings: i. Water inlet temperature, heat delivered by the collector and mass flow rate of the collector if the ambient temperature is 10 °C and water outlet temperature is 65 °C. Take Cp (H20) = 4.2 kJ-kg-K-1 (36%) ii. Ambient temperature, if the water inlet temperature is 30°C (12%) (c) The household consumes 250 litres of hot water at 55 °C each day. The solar collector seasonal efficiency is 0.5 and the annual solar irradiation is 1.85 MWh/m², and the incoming water is supplied at 10 °C. Estimate the amount of energy saved per annum as a proportion of the current consumption if the existing means for provision of hot water is a gas heated system. (22%) Data for Question-1 n = Fzta - FUL = t;- 1. q=n1,4