Assumptions made for calculation of logarithmic mean temperature diffe

1.	Assumptions made for calculation of logarithmic mean temperature difference are
A.	Constant overall heat transfer coefficient
B.	The kinetic and potential energy changes are negligible
C.	There is no conduction of heat along the tubes of heat exchanger
Answer» B. The kinetic and potential energy changes are negligible

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Exhaust gases (c P = 1.12 k J/kg K) flowing through a tubular heat exchanger at the rate of 1200 kg/hr are cooled from 400 degree Celsius to 120 degree Celsius. This cooling is affected by water (c P = 4.18 k J/kg K) that enters the system at 10 degree Celsius at the rate of 1500 kg/hr. If the overall heat transfer coefficient is 500 k J/m2 hr degree, what heat exchanger area is required to handle the load for counter flow arrangement?
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Assumptions made for calculation of logarithmic mean temperature difference are(i) Constant overall heat transfer coefficient(ii) The kinetic and potential energy changes are negligible(iii) There is no conduction of heat along the tubes of heat exchangerIdentify the correct statements
EXHAUST_GASES_(C_P_=_1.12_K_J/KG_K)_FLOWING_THROUGH_A_TUBULAR_HEAT_EXCHANGER_AT_THE_RATE_OF_1200_KG/HR_ARE_COOLED_FROM_400_DEGREE_CELSIUS_TO_120_DEGREE_CELSIUS._THIS_COOLING_IS_AFFECTED_BY_WATER_(C_P_=_4.18_K_J/KG_K)_THAT_ENTERS_THE_SYSTEM_AT_10_DEGREE_CELSIUS_AT_THE_RATE_OF_1500_KG/HR._IF_THE_OVERALL_HEAT_TRANSFER_COEFFICIENT_IS_500_K_J/M2_HR_DEGREE,_WHAT_HEAT_EXCHANGER_AREA_IS_REQUIRED_TO_HANDLE_THE_LOAD_FOR_COUNTER_FLOW_ARRANGEMENT??$
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Assumptions made for calculation of logarithmic mean temperature difference are

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