Steam enters a counterflow heat exchanger operating at steady state at 0.07 mpa with a quality of 0.9 and exits at the same pressure as saturated liquid. the steam mass flow rate is 1.3 kg/min. a separate stream of air with a mass flow rate of 100 kg/min enters at 30°c and exits at 60 c. the ideal gas model with cp = 1.005 kj/kg-k can be assumed for air. kinetic and potential energy effects are negligible. determine the temperature of the entering steam, in °c. for the overall heat exchanger as the control volume, what is the rate of heat transfer, in kw

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.

Line joining liquid phase with liquid and solid phase mixture is known as: a) liquidus b) solidus c) tie line d) none of the mentioned

An electrical motor raises a 50kg load at a construct velencity .calculate the power of the motor, if it takes 40sec to raise the load through a height of 24m(take g =9.8n/g)