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Diffstat (limited to '3012/CH7/EX7.10/Ex7_10.sce')
-rwxr-xr-x | 3012/CH7/EX7.10/Ex7_10.sce | 49 |
1 files changed, 49 insertions, 0 deletions
diff --git a/3012/CH7/EX7.10/Ex7_10.sce b/3012/CH7/EX7.10/Ex7_10.sce new file mode 100755 index 000000000..9d703feb2 --- /dev/null +++ b/3012/CH7/EX7.10/Ex7_10.sce @@ -0,0 +1,49 @@ +// Given:- +EfFdot = 100.00 // exergy rate of fuel entering the boiler in MW +cF = 1.44 // unit cost of fuel in cents per kw.h +Zbdot = 1080.00 // the cost of owning and operating boiler in dollars per hour +Ef1dot = 35.00 // exergy rate of exiting steam from the boiler in MW +p1 = 50.00 // pressure of exiting steam from the boiler in bar +T1 = 466.00 // temperature of exiting steam from the boiler in degree celcius +Ztdot = 92.00 // the cost of owning and operating turbine in dollars per hour +p2 = 5.00 // pressure of exiting steam from the turbine in bars +T2 = 205.00 // temperature of exiting steam from the turbine in degree celcius +m2dot = 26.15 // mass flow rate of exiting steam from the turbine in kg/s +T0 = 298.00 // in kelvin + + +// Part(a) +// From table A-4, +h1 = 3353.54 // in kj/kg +h2 = 2865.96 // in kj/kg +s1 = 6.8773 // in kj/kg.k +s2 = 7.0806 // in kj/kg.k + +// Calculations +// From assumption,For each control volume,Qcvdot = 0 and kinetic and potential energy effects are negligible,the mass and energy rate +// balances for a control volume enclosing the turbine reduce at steady state to give +Wedot = m2dot *(h1-h2)/1000 // power in MW +Ef2dot = Ef1dot+m2dot*(h2-h1-T0*(s2-s1))/1000 // the rate exergy exits with the steam in MW + +// Results +printf( ' For the turbine,the power is %.2f MW.',Wedot) +printf( ' For the turbine,the rate exergy exits with the steam is %.2f MW.',Ef2dot) + +// Part(b) +// Calculations +c1 = cF*(EfFdot/Ef1dot) + ((Zbdot/Ef1dot)/10**3)*100 // unit cost of exiting steam from boiler in cents/Kw.h +c2 = c1 // Assigning the same unit cost to the steam entering and exiting the turbine +ce = c1*((Ef1dot-Ef2dot)/Wedot) + ((Ztdot/Wedot)/10**3)*100 // unit cost of power in cents/kw.h + +// Results +printf('The unit costs of the steam exiting the boiler of exergy is: %.2f cents per kw.h.',c1) +printf('The unit costs of the steam exiting the turbine of exergy is: %.2f cents per kw.h.',c2) +printf('Unit cost of power is: %f cents per kw.h.',ce) + +// Part(c) +C2dot = (c2*Ef2dot*10**3)/100 // cost rate for low-pressure steam in dollars per hour +Cedot = (ce*Wedot*10**3)/100 // cost rate for power in dollars per hour + +// Results +printf( ' The cost rate of the steam exiting the turbine is: %.2f dollars per hour.',C2dot) +printf( ' The cost rate of the power is: %.2f dollars per hour.',Cedot) |