From b1f5c3f8d6671b4331cef1dcebdf63b7a43a3a2b Mon Sep 17 00:00:00 2001 From: priyanka Date: Wed, 24 Jun 2015 15:03:17 +0530 Subject: initial commit / add all books --- 2705/CH10/EX10.3/Ex10_3.sce | 44 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 44 insertions(+) create mode 100755 2705/CH10/EX10.3/Ex10_3.sce (limited to '2705/CH10/EX10.3') diff --git a/2705/CH10/EX10.3/Ex10_3.sce b/2705/CH10/EX10.3/Ex10_3.sce new file mode 100755 index 000000000..5ea7c08db --- /dev/null +++ b/2705/CH10/EX10.3/Ex10_3.sce @@ -0,0 +1,44 @@ +clear; +clc; +disp('Example 10.3'); + +// aim : To determine +// (a) the thermal efficiency of the boiler +// (b) the equivalent evaporation of the boiler +// (c) the new coal consumption + +// given values +ms_dot = 5400;// steam feed rate, [kg/h] +P = 750;// steam pressure, [kN/m^2] +x = .98;// steam dryness fraction +Tf1 = 41.5;// feed water temperature, [C] +CV = 31000;// calorific value of coal used in the boiler, [kJ/kg] +mc1 = 670;// rate of burning of coal/h, [kg] +Tf2 = 100;// increased water temperature, [C] + +// solution +// (a) +SRC = ms_dot/mc1;// steam raised/kg coal, [kg] +hf = 709.3;// [kJ/kg] +hfg = 2055.5;// [kJ/kg] +h1 = hf+x*hfg;// specific enthalpy of steam raised, [kJ/kg] +// from steam table +hfw = 173.9;// specific enthalpy of feed water, [kJ/kg] +EOB = SRC*(h1-hfw)/CV;// efficiency of boiler +mprintf('\n (a) The thermal efficiency of the boiler is = %f percent\n',EOB*100); + +// (b) +he = 2256.9;// specific enthalpy of evaporation, [kJ/kg] +Ee = SRC*(h1-hfw)/he;// equivalent evaporation[kg/kg coal] +mprintf('\n (b) The equivalent evaporation of boiler is = %f kg/kg coal\n',Ee); + +// (c) +hw = 419.1;// specific enthalpy of feed water at 100 C, [kJ/kg] +Eos = ms_dot*(h1-hw);// energy of steam under new condition, [kJ/h] +neb = EOB+.05;// given condition new efficiency of boiler if 5%more than previous +Ec = Eos/neb;// energy from coal, [kJ/h] +mc2 = Ec/CV;// mass of coal used per hour in new condition, [kg] +mprintf('\n (c) Mass of coal used in new condition is = %f kg\n',mc2); +mprintf('\n The saving in coal per hour is = %f kg\n',mc1-mc2); + +// End -- cgit