A one-shell pass and six-tube passes heat exchanger in a factory is used to decrease the temperature of Hot Oil(Cp=1900 J/kg. oC , Temp=200 oC flowing through tube with the help of water(Cp=4195 J/kg. oC) from nearbylake. Water initially at 16 oC leaves the heat exchanger at 90 oC by flowing at the rate of 0.3 kg/sec. Thevalues of the Ui and Uo should be 2200 W/m2 oC and 1500 W/m2 oC, respectively.

Steel is coated with a thin layer of ceramic to protect against corrosion. what do you expect to happen to the coating when the temperature of the steel is increased significantly? explain.

Air is to be cooled in the evaporator section of a refrigerator by passing it over a bank of 0.8-cm-outer-diameter and 0.4-m-long tubes inside which the refrigerant is evaporating at -20°c. air approaches the tube bank in the normal direction at 0°c and 1 atm with a mean velocity of 4 m/s. the tubes are arranged in-line with longitudinal and transverse pitches of sl- st 1.5 cm. there are 30 rows in the flow direction with 15 tubes in each row. determine (a) the refrigeration capacity of this system and (b) pressure drop across the tube bank. evaluate the air properties at an assumed mean temperature of -5°c and 1 atm. is this a good assumption?

Manometers are good examples of measuring instruments, nowadays they are not as common as before. a)-capacitive probe gauges b)-gravitational gauges deformation ) gauges d)-digital gauges