Reference no: EM133319152

Question:  You find out that the EPA is planning to limit the availability of the refrigerant used in the Bama Pie refrigeration heat exchanger you have been working on, so you need to replace it. One potential replacement is to use a particular heat transfer fluid inside the tubes (0.7-cm-insidediameter). Determine the mass flow rate of the fluid required to replace the refrigerant, while still achieving the same amount of cooling (in Watts). The heat transfer fluid enters the tubes at a temperature of -22.5°C and leaves at a temperature of -17.5°C. Follow the same assumptions regarding the air temperature as used in the previous problem.

Assume that the conductive resistance of the tubing is negligible. Assume that the surface area of the inside of the tubes is equivalent to the surface area on the outside of the tubes. The tube inlets are equipped with 'turbulators' that ensure the flow through the tube is turbulent, even at low Reynolds numbers. Use the following property values for the heat transfer fluid: μ=0.004 Pa⋅s;ρ=1069 kg/m3;Pr =80.8; and k=0.347 W/m⋅K; the specific heat of this heat transfer fluid is UNKNOWN. If you did not get a final answer for the previous question, use: hi?=175 W/m2⋅K and Q??=9500 W.