An industrial process air heating system is shown in the accompanying sketch. The air being heated...

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An industrial process air heating system is shown in the accompanying sketch. The air being heated by the combination of solar plus auxiliary enters the heating section at 35°C, is partially heated by solar energy from the storage tank via the load heat exchanger, and then is further heated by the auxiliary exchanger to 55°C. The collector has an area of 80 m². F(ta) = 0.78 and can be considered as constant for this problem. FRU₁ = 4.45 W/m² °C. The fully mixed tank has a capacity of 5000 kg. It is well insulated, and (UA), = 140 kJ/h °C. The tank is outdoors. The load heat exchanger has an effectiveness near unity (i.e., it is very large) so the return temperature to the tank is always the same as the inlet air temperature. The air to be heated flows at constant rate for 24 h a day at a rate of 0.83 kg/s and has a heat capacity of 1013 J/kg °C The flow rate through the load heat exchanger is controlled, upto a maximum of 0.056 kg/s so that the air leaving the load heat exchanger never exceeds 55°C. - Collector Time 6-7 7-8 8-9 9-10 10-11 11-12 Tank Ta, °C 7 8 9 9 9 12 Auxiliary heat exchanger Solar load heat exchanger IT, MJ/m² 0 0 1.09 1.75 2.69 3.78 The radiation on the collector and ambient temperature data for a 12-h period are shown in the table. The initial tank temperature is 47°C. For this period, how much energy is supplied to the load from the tank? How much auxiliary energy is needed? Time 12-1 1-2 2-3 3-4 4-5 5-6 55°C Ta, °C 15 14 12 12 12 11 ww Air, 35°C IT, MJ/m² 3.87 3.41 2.77 1.82 1.53 0 An industrial process air heating system is shown in the accompanying sketch. The air being heated by the combination of solar plus auxiliary enters the heating section at 35°C, is partially heated by solar energy from the storage tank via the load heat exchanger, and then is further heated by the auxiliary exchanger to 55°C. The collector has an area of 80 m². F(ta) = 0.78 and can be considered as constant for this problem. FRU₁ = 4.45 W/m² °C. The fully mixed tank has a capacity of 5000 kg. It is well insulated, and (UA), = 140 kJ/h °C. The tank is outdoors. The load heat exchanger has an effectiveness near unity (i.e., it is very large) so the return temperature to the tank is always the same as the inlet air temperature. The air to be heated flows at constant rate for 24 h a day at a rate of 0.83 kg/s and has a heat capacity of 1013 J/kg °C The flow rate through the load heat exchanger is controlled, upto a maximum of 0.056 kg/s so that the air leaving the load heat exchanger never exceeds 55°C. - Collector Time 6-7 7-8 8-9 9-10 10-11 11-12 Tank Ta, °C 7 8 9 9 9 12 Auxiliary heat exchanger Solar load heat exchanger IT, MJ/m² 0 0 1.09 1.75 2.69 3.78 The radiation on the collector and ambient temperature data for a 12-h period are shown in the table. The initial tank temperature is 47°C. For this period, how much energy is supplied to the load from the tank? How much auxiliary energy is needed? Time 12-1 1-2 2-3 3-4 4-5 5-6 55°C Ta, °C 15 14 12 12 12 11 ww Air, 35°C IT, MJ/m² 3.87 3.41 2.77 1.82 1.53 0

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Solution To solve this problem we need to first calculate the energy input to the tank from the solar collector and the auxiliary heating system 1 Sol... View the full answer