A shell-and-tube heat exchanger is used for cooling 47 kg/s of a process stream flowing through the tubes from 160 C to 100°C. This heat exchanger has a total of 100 identical tubes, each with an inside diameter of 2.5 cm and negligible wall thickness. The average properties of the process stream are: rho 950 kg/m3, k = 0.50 w/m. K, cp-3.5 kJ/kg-K and μα 2.0 mPa-s. The coolant stream is water (cp- 4.18 kJ/kg K) at a flow rate of 66 kg/s and an inlet temperature of 10 C, which yields an average shell-side heat transfer coefficient of 4.0 kW/m2-K. Calculate the tube length if the heat exchanger has

(a) a 1-shell pass and a 1-tube pass and
(b) a 1-shell pass and 4-tube passes 1.

Amass of m 1.5 kg of steam is contained in a closed rigid container. initially the pressure and temperature of the steam are: p 1.5 mpa and t 240°c (superheated state), respectively. then the temperature drops to t2= 100°c as the result of heat transfer to the surroundings. determine: a) quality of the steam at the end of the process, b) heat transfer with the surroundings. for: p1.5 mpa and t 240°c: enthalpy of superheated vapour is 2900 kj/kg, specific volume of superheated vapour is 0. 1483 m/kg, while for t 100°c: enthalpy of saturated liquid water is 419kj/kg, specific volume of saturated liquid water is 0.001043m/kg, enthalpy of saturated vapour is 2676 kj/kg, specific volume of saturated vapour is 1.672 m/kg and pressure is 0.1 mpa.

Ahouse has the following electrical appliance usage (1) single 40w lamp used for 4 hours per day (2) single 60w fan used for 12 hours per day (3) single 200w refrigerator that runs 24 hours per day with compressor run 12 hours and off 12 hours find the solar power inverter size in watt with correction factor of 1.25.

Coiled springs ought to be very strong and stiff. si3n4 is a strong, stiff material. would you select this material for a spring? explain.