8. A waste heat recovery boler produces 1 MPa dry saturated steam from 100 C feedwater. The boiler receives hot gases Cp 1.0) at 4.2 kg per sec at a temperature of 950 C. After passing through the waste heat boiller, the temperature of hot gases has been reduced to 250 C. How much steam in kg is produced per hour? Note: At 1 MPa dry saturated, h 2778.1 k/kg. A. 4487.8 kg B. 48478 kg C 4748.8 kg D. 4887.4 kg

In the evaporator of an air conditioning system, air flows over finned tubes through with the refrigerant R134a flows. air out refrigerant in refrigerant out air in The mass flow rate of the air is 0.75 kg/s and the air enters at 40°C and pressure 1.04 bar. The air leaves the evaporator at 25°C and 1.01 bar. The refrigerant enters the evaporator with a quality of 0.2 and a temperature of 12°C. The refrigerant exits as saturated vapor. Obtain the properties of air and R134a using the fluids "Air" and "R134a" in EES. What is the volumetric flow rate of the air entering the heat exchanger (m^3/s)? Determine the rate of heat transfer from the air to the refrigerant (W). Determine the mass flow rate of the refrigerant (kg/s).

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Explain the heat transferred from a furnace (Q) to convert the boiler feed water at 25 ° C into superheated steam at 17 bar and 250 ° C.