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Diffstat (limited to '3681/CH4/EX4.23/Ex4_23.sce')
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diff --git a/3681/CH4/EX4.23/Ex4_23.sce b/3681/CH4/EX4.23/Ex4_23.sce new file mode 100644 index 000000000..e66cd8ea8 --- /dev/null +++ b/3681/CH4/EX4.23/Ex4_23.sce @@ -0,0 +1,25 @@ +// Calculating the efficiency of machine and amount of cooling water
+clc;
+disp('Example 4.23, Page No. = 4.50')
+// Given Data
+MVA = 30;// MVA rating of turbo-alternator
+Ti = 15;// Inlet temperature of air (in degree celsius)
+To = 45;// Outlet temperature of air (in degree celsius)
+H = 750;// Baromatric height (in mm of mercury)
+Va = 30;// Volume of air (in meter cube per second)
+nf = 0.4;// Fan efficiency
+cp = 1000;// Specific heat of air at constant pressure (in J per kg per degree celsius)
+V = 0.78;// Volume of 1 kg of air at N.T.P. (in meter cube)
+pf = 0.8;// Power factor
+// Calculation of the efficiency of machine
+T = To-Ti;// Temperature rise limit (in degree celsius)
+Q = Va/((V*10^(3)/(cp*T))*((Ti+273)/273)*(760/H));// Total losses (in kW)
+P_out = 30*10^(3)*pf;// Output power (in kW)
+n = P_out/(P_out+Q)*100;// Fan power (in kW)
+disp(n,'(a) Efficiency of machine (in percentage)=');
+// Calculation of the amount of cooling water
+T = 8;// Temperature rise of water (in degree celsius)
+Vw = 0.24*Q/T;// Amount of cooling water (in litre per second)
+disp(Vw,'(b) Amount of cooling water (litre per second)=');
+//in book efficiency is equal to 95.7% and amount of cooling water 32.4 (litre per second). The answers vary due to round off error
+
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