FIRST LAW OF THERMODYNAMICSThermodynamicsExample 5: Overall Thermodynamic BalanceA nuclear facility (primary side) is to be studied as a complete system. The heatproduced by the heat source is 1.36 x 10^{10} Btu/hr. The heat removed by the heatexchanger (steam generator) is 1.361 x 10^{10} Btu/hr. What is the required pump power tomaintain a stable temperature?Solution:= pump work, = heat produced by the heat source, heat transferredW_{p}Q_{c}Qinto steam generatorm(hpeke)W_{p}Q_{c}Q_{sg}m(hpeke)1) For a closed system, the mass entering and leaving the system is zero, therefore,is constant. The energy entering and leaving the system is zero, and you canmassume that the ke and pe are constant so that:_{c}+_{p}=sgQWQ2) =W_{p}Q_{sg}Q_{c}= 1.361 x 10^{10} Btu/hr - 1.36 x 10^{10} Btu/hr= 1.0 x 10^{7} Btu/hr= 4007 hpW_{p}Of the examples just completed, emphasis should be placed on the heat exchanger analysis. Boththe primary side and the secondary side have their own energy balances as the heat energy istransferred from one fluid to the other. In calculating heat exchanger heat transfer rates, wefound that we could use the equations .Qmc_{pD}hPerhaps a short analysis of the secondary side of the heat exchanger will aid in understandingthe heat exchanger’s importance in the energy conversion process.HT-01 Page 66 Rev. 0

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