Two identical double-pipe heat exchangers areconstructed of a 2-in standard schedule 40 pipe placed inside a3-in standard pipe. The length of the exchangers is 10 ft; 40gal/min of water initially at 80â—¦F is to be heated by passingthrough the inner
pipes of the exchangers in a series arrangement, and 30 gal/min ofwater at 120â—¦F and 30 gal/min of water at 200â—¦F are available toaccomplish the heating. The two heating streams may be mixed in anyway desired before and after they enter the heat exchangers.Determine the flow arrangement for optimum performance (maximumheat transfer) and the total heat transfer under these conditions.Use both NTU and LMTD methods.
