A preliminary design study is to be carried out on an oil-oil heat exchanger with the following specification:Cold Fluid: mass flow rate = 64 tons/hr, heat capacity = 2612 J/kg K, in temp = 171.5 C, out temp = 239 CHot Fluid: mass flow rate = 28.8 tons/hr, heat capacity = 2612 J/kg K, in temp = 340 C, out temp = ?If the overall coefficient of heat exchange U = 502 W/m2K, calculate the heat exchange surface area required for a simple counter flow.
Q = U * A * dTlm Calculate the heat gained by the cold side, Q = mass * specific heat * temperature change Assuming no heat losses to the surroundings which is a typical assumption, calculate the outlet temperature of the hot side using the same equation as you used for the cold side. Now you can calculate the log mean temperature difference dTlm. Use the first equation to solve for the area.
