Solar radiation is incident on the glass cover of a solar collector at a rate of 700W/m². The glass of collector absorbs 88 percent of the incident radiation on it and has an emissivity of 0.9. The...

Extracted text: Solar radiation is incident on the glass cover of a solar collector at a rate of 700W/m². The glass of collector absorbs 88 percent of the incident radiation on it and has an emissivity of 0.9. The entire hot water needs of a family can be provided by a single collector of 1.2m height and 2m width. The temperature of the glass cover of the collector is measured to be 35C° on a day when the surrounding air temperature is 25C° and the wind is blowing at 30km/h. The effective sky temperature for radiation exchange between the glass cover and the open sky is -40C°. Water enters the tubes which attached to the absorber plate at a rate of 1kg/min. Assuming the back surface of the absorber plate to be heavily insulated and the only heat loss to occur through the glass cover, determine (a) the total rate of heat loss from the collector, (b) the collector efficiency, which is the ratio of the amount of heat transferred to the water to the solar energy incident on the collector, and (c) the temperature rise of water as it flows through the collector. Tky =-40°C %3D Solar collector 35°C Air Solar 25°C radiation