Water at a rate of m=63 g/s at 38°C is available for use as a coolant in a double- pipe heat exchanger whose total surface area is 1.4 m2. The water is to be used to cool an oil (Cp=2.09 kJ/kg K) from an initial temperature of 121°C. Because of other circumstances, an exit water temperature greater than 99°C cannot be allowed. The exit temperature of the oil must not be below 60°C. The overall heat transfer coefficient is 284 W/m2K, and is assumed to be independent of flowrate of either stream in the range of interest. Estimate the maximum flowrate of oil that may be cooled for cocurrent and countercurrent exchangers, assuming the flowrate of water is fixed at 63 g/s.

When at a point two solid phase changes to one solid phase on cooling then it is known as a) eutectoid point b) eutectic point c) peritectic point d) peritectoid point

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.

When using the ohmmeter function of a digital multimeter, the leads are placed in what position relative to the component being tested? a. parallel b. control c. series d. line