Some electronics are mounted in an enclosure with dimensions of 9 X 16 X 22 cm. Power consumption by the electronics under steady conditions is 600 W. The temperature of the equipment cannot exceed 60 C. This is to be achieved by either blowing atmospheric air through the unit or by circulating water through the unit (a heat exchanger transferring energy from the air inside the enclosure to the cooling water). Determine the mass rate of flow (kg/s) and the volumetric flow rate (m3/s) if
a. the coolant is air entering at 1 bar, 20 C with a temperature rise of 30 C (i..e the cooling air exits at 50 C).
b. the coolant is water entering at 1 bar, 20 C with a temperature rise of 40 C.