A water-cooled condenser in a large refrigeration system uses R-134a as its refrigerant fluid. The refrigerant enters the conden
ser at 1.0 MPa and 60 deg C, at a rate of 0.2 kg/s, and exits as a liquid at 0.95 MPa and 35 deg C. Cooling water enters the condenser at 10 degC and exits at 20 degC.
Create a schematic representation of the condenser and draw the boundary of the system needed to answer the next questions. Include the mass and energy interactions across the boundary.
Create a schematic representation of the condenser and draw the boundary of the system needed to answer the next questions. Include the mass and energy interactions across the boundary.
1 answer:
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Answer:
<em> - 14.943 W/m^2K ( negative sign indicates cooling ) </em>
Explanation:
Given data:
Area of FPC = 4 m^2
temp of water = 60°C
flow rate = 0.06 l/s
ambient temperature = 8°C
exit temperature = 49°C
<u>Calculate the overall heat loss coefficient </u>
Note : heat lost by water = heat loss through convection
m*Cp*dT = h*A * ( T - To )
∴ dT / T - To = h*A / m*Cp ( integrate the relation )
In ( ) = h* 4 / ( 0.06 * 10^-3 * 1000 * 4180 )
In ( 41 / 52 ) = 0.0159*h
hence h = - 0.2376 / 0.0159
= - 14.943 W/m^2K ( heat loss coefficient )