In a pipe-within-a-pipe heat exchanger, water is flowing in the annulus and an aniline-alcohol solution having the

Question:

In a pipe-within-a-pipe heat exchanger, water is flowing in the annulus and an aniline-alcohol solution having the properties listed in Problem 6.20 is flowing in the central pipe. The inner pipe is 0.527 in. ID, 0.625 in. OD, and the ID of the outer pipe is 0.750 in. For a water bulk temperature of 80?F and an aniline bulk temperature of 140?F, determine the overall heat transfer coefficient based on the outer diameter of the central pipe and the frictional pressure drop per unit length of the water and the aniline for the following volumetric flow rates,(a) Water rate 1 gpm, aniline rate 1 gpm,(b) Water rate 10 gpm, aniline rate 1 gpm,(c) Water rate 1 gpm, aniline rate 10 gpm, and(d) Water rate 10 gpm, aniline rate 10 gpm (L/D = 400).GIVENPipe-within-a-pipe heat exchanger with water in the annulus and aniline-alcohol solution in the inner pipeSolution properties listed abovePipe diametersInner pipe Du = 0.527 in = 0.0439 ftDi = 0.625 in = 0.0521 ftInside of outer pipe Do = 0.750 in = 0.0625 ftBulk temperaturesWater (Tw) = 80?FAniline (Ta) = 140?FL/D = 400ASSUMPTIONSSteady stateThermal resistance of the pipe is negligibleNusselt number can be estimated from correlations for constant and uniform surface temperatureThe effect of viscosity variation is negligibleThe tubes are smoothFully developed flow (L/D =400)