The machines of a big textile factory, see fig, have an electrical power demand of 600...

 

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The machines of a big textile factory, see fig, have an electrical power demand of 600 kWel during normal operation. The efficiency of the machines is 95%. During summer months, a heat flow of 10 kW enters the room by sun radiation. The factory is equipped with an air-conditioning system. A fan is used to remove a volume flow of 5000 m3 h-1 from the room. The air has a temperature of 27 - C. 50% of this flow is leaving the system to the atmosphere. The make-up for this loss of mass is fresh air at a temperature of 20 -C. Determine the heat flow, in kW, which is to be removed by the cooler at steady-state conditions. Assumptions. The constant specific heat capacity of air is cp = 1.0 kJ kg-1 K-1. • The density is p = 1.25 kg m-3. • Neglect the electrical power demand of the fan There are 2 steps to solve this one. sun Textile factory machine Pel Tout= 27°C Fan Qc 100% 50% Mixer 50% Air in Tin = 20°C The machines of a big textile factory, see fig, have an electrical power demand of 600 kWel during normal operation. The efficiency of the machines is 95%. During summer months, a heat flow of 10 kW enters the room by sun radiation. The factory is equipped with an air-conditioning system. A fan is used to remove a volume flow of 5000 m3 h-1 from the room. The air has a temperature of 27 - C. 50% of this flow is leaving the system to the atmosphere. The make-up for this loss of mass is fresh air at a temperature of 20 -C. Determine the heat flow, in kW, which is to be removed by the cooler at steady-state conditions. Assumptions. The constant specific heat capacity of air is cp = 1.0 kJ kg-1 K-1. • The density is p = 1.25 kg m-3. • Neglect the electrical power demand of the fan There are 2 steps to solve this one. sun Textile factory machine Pel Tout= 27°C Fan Qc 100% 50% Mixer 50% Air in Tin = 20°C