Air (cp = 1.005 kJ/kg·°C) is to be preheated by hot exhaust gases in a crossflow heat exchanger before it enters the furnace. Air enters the heat exchanger at 95 kPa and 20°C at a rate of 1.6 m3 /s. The combustion gases (cp = 1.10 kJ/kg·°C) enter at 180°C at a rate of 2.2 kg/s and leave at 95°C. Determine the rate of heat transfer to the air.

1. The heat produced in a boiler is transferred from the combustion products to the water. While the temperature of the combustion products decreases from 1100 °C to 550 °C, the pressure remains constant at 0.1 MPa. The average specific heat at constant pressure of the combustion products is 1.09 kJ/kg.K. The water enters the system at 0.8 MPa and 150 °C, and leaves at 0.8 MPa and 250 °C. Determine the second law efficiency and the irreversibility for each kilogram of water vaporized for this process.   Note: This is a thermodynamics course question. Please provide a solution that is clear and quick.

Air (cp = 1.005 kJ/kg·°C) is to be preheated by hot exhaust gases in a crossflow heat exchanger before it enters the furnace. Air enters the heat exchanger at 95 kPa and 20°C at a rate of 1.6 m3 /s. The combustion gases (cp = 1.10 kJ/kg·°C) enter at 180°C at a rate of 2.2 kg/s and leave at 95°C. Determine the rate of entropy generation.

Thermodynamic