AaBbCc AaBbCc · AaBbC AaBbCcC AaB AABBCCC AoBbrの..1 Normal1 No Spac.. Heading 1Heading 2TitleSubtitleSubtlesepeFontParagraphStyles2 3 IN41 5 6 .7.1 819 10 11 12. 13 I 14. 15. 16 .17 118 I 19A counterflow double-pipe heat exchanger with A, = 9m² is used for cooling a liquidstream (c, = 3.15 kJ/kg. K) at a rate of 10.0 kg/s with an inlet temperature of 90°C. Thecoolant (c, = 4.2 kJ/kg. K) enters the heat exchanger at a rate of 8.0 kg/s with an inlettemperature of 10°C. The plant data gave the following equation for the overall heattransfer coefficient in W/m . K:U = 600/(1/m + 2/m), where m, and m, are the cold-and hot-stream flow rates in kg/s, respectively.a) Calculate the rate of heat transfer and the outlet stream temperatures for thisunit.b) The existing unit is to be replaced. A vendor is offering a very attractive discounton two identical heat exchangers that are presently stocked in its warehouse,each with A, = 5m. Because the tube diameters in the existing and new unitsare the same, the above heat transfer coefficient equation is expected to be validfor the new units as well. The vendor is proposing that the two new units couldbe operated in parallel, such that each unit would process exactly one-half theflow rate of each of the hot and cold streams in a counterflow manner; hence,they together would meet (or exceed) the present plant heat duty. Give yourrecommendation, with supporting calculations, on this replacement proposal.19°C

Question

Accepted Answer

To find the rate of heat transfer and calculations with the recommendations as,

kg/ an inlet temperature of e heat exchanger at a rate of 8.0 kg/s wit ata gave the following equation for the ow 600/(1/mº³ + 2/m08), where m, and m, ar respectively.