Consider a concentric tube heat exchanger with an area of 50 m2operating under the following conditions:Hot fluidCold fluidHeat capacity rate, KW/K63Inlet temperature, oC6030Outlettemperature, oC-54(a) Determine the outlet temperature of the hot fluid.(3points)(b) Is the heat exchanger operating in counter flow or parallel flow, or can't you tell from the available information

Sagot :

Answer:

a) 48°C

b) The heat exchanger is operating in counter flow

Explanation:

a) Determine the outlet temperature of the hot fluid ( To )

= Heat lost by hot body( fluid )  = heat gained by cold body ( fluid )

Mh Cph [ Ti - To ] = Mc Cpc [ Tco - Tci ]

6000 [ 33 - To ] = 3 * 1000 [ 327 - 303 ]

therefore:  - To = [ ( 3 * 1000 [ 327 - 303 ] ) - ( 6000 * 33 ) ] / 6000

hence To ( outlet temp ) = 48° C

b) The heat exchanger is operating in counter flow because Tco > To

note : heat capacity of hot fluid ( Mh Cph ) = 6000 watts

         heat capacity of cold fluid ( Mc Cpc ) = 3000 watts

          Area = 50 m^2

convert all temperatures to Kelvin before calculation