initial commit / add all books

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+// Display mode

+mode(0);

+// Display warning for floating point exception

+ieee(1);

+clear;

+clc;

+disp("Engineering Thermodynamics by Onkar Singh Chapter 8 Example 8")

+T_cond=115;//condensate temperature in degree celcius

+Cp=4.18;//specific heat at constant pressure in KJ/kg K

+P=30*10^3;//actual alternator output in KW

+n_boiler=0.9;//boiler efficiency

+n_alternator=0.98;//alternator efficiency

+disp("from steam tables,at state 2,h2=3301.8 KJ/kg,s2=6.7193 KJ/kg K")

+h2=3301.8;

+s2=6.7193;

+disp("h5=hf at 0.05 bar=137.82 KJ/kg,v5= vf at 0.05 bar=0.001005 m^3/kg")

+h5=137.82;

+v5=0.001005;

+disp("Let mass of steam bled for feed heating be m kg/kg of steam generated in boiler.Let us also assume that condensate leaves closed feed water heater as saturated liquid i.e")

+disp("h8=hf at 3 bar=561.47 KJ/kg")

+h8=561.47;

+disp("for process 2-3-4,s2=s3=s4=6.7193 KJ/kg K")

+s3=s2;

+s4=s3;

+disp("Let dryness fraction at state 3 and state 4 be x3 and x4 respectively.")

+disp("s3=6.7193=sf at 3 bar+x3* sfg at 3 bar")

+disp("from steam tables,sf=1.6718 KJ/kg K,sfg=5.3201 KJ/kg K")

+sf_3bar=1.6718;

+sfg_3bar=5.3201;

+disp("so x3=(s3-sf_3bar)/sfg_3bar")

+x3=(s3-sf_3bar)/sfg_3bar

+x3=0.949;//approx.

+disp("s4=6.7193=sf at 0.05 bar+x4* sfg at 0.05 bar")

+disp("from steam tables,at 0.05 bar,sf=0.4764 KJ/kg K,sfg=7.9187 KJ/kg K")

+sf=0.4764;

+sfg=7.9187;

+disp("so x4=(s4-sf)/sfg")

+x4=(s4-sf)/sfg

+x4=0.788;//approx.

+disp("thus,h3=hf at 3 bar+x3* hfg at 3 bar in KJ/kg")

+disp("here  from steam tables,at 3 bar,hf_3bar=561.47 KJ/kg,hfg_3bar=2163.8 KJ/kg K")

+hf_3bar=561.47;

+hfg_3bar=2163.8;

+h3=hf_3bar+x3*hfg_3bar 

+disp("h4=hf at 0.05 bar+x4*hfg at 0.05 bar in KJ/kg")

+disp("from steam tables,at 0.05 bar,hf=137.82 KJ/kg,hfg=2423.7 KJ/kg")

+hf=137.82;

+hfg=2423.7;

+h4=hf+x4*hfg

+disp("assuming process across trap to be of throttling type so,h8=h9=561.47 KJ/kg.Assuming v5=v6,")

+h9=h8;

+v6=v5;

+disp("pumping work=(h7-h6)=v5*(p1-p5)in KJ/kg")

+p1=60;//pressure of steam in high pressure turbine in bar

+p5=0.05;//pressure of steam in low pressure turbine in bar

+v5*(p1-p5)*100

+disp("for mixing process between condenser and feed pump,")

+disp("(1-m)*h5+m*h9=1*h6")

+disp("h6=m(h9-h5)+h5")

+disp("we get,h6=137.82+m*423.65")

+disp("therefore h7=h6+6.02=143.84+m*423.65")

+disp("Applying energy balance at closed feed water heater;")

+disp("m*h3+(1-m)*h7=m*h8+(Cp*T_cond)")

+disp("so (m*2614.92)+(1-m)*(143.84+m*423.65)=m*561.47+480.7")

+disp("so m=0.144 kg")

+m=0.144;

+h6=137.82+m*423.65;

+h7=143.84+m*423.65;

+disp("steam bled for feed heating=0.144 kg/kg steam generated")

+disp("The net power output,W_net=(h2-h3)+(1-m)*(h3-h4)-(1-m)*(h7-h6) in KJ/kg steam generated")

+W_net=(h2-h3)+(1-m)*(h3-h4)-(1-m)*(h7-h6)

+disp("mass of steam required to be generated=in kg/s")

+P/(n_alternator*W_net)

+disp("or in kg/hr")

+26.23*3600

+disp("so capacity of boiler required=94428 kg/hr")

+disp("overall thermal efficiency=W_net/Q_add")

+disp("here Q_add=(h2-h1)/n_boiler in KJ/kg")

+Q_add=(h2-Cp*T_cond)/n_boiler 

+disp("overall thermal efficiency=")

+W_net/Q_add

+disp("in percentage")

+W_net*100/Q_add

+disp("so overall thermal efficiency=37.24%")

diff --git a/2873/CH8/EX8.8/Ex8_8_1.jpg b/2873/CH8/EX8.8/Ex8_8_1.jpg
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diff --git a/2873/CH8/EX8.8/Ex8_8_2.pdf b/2873/CH8/EX8.8/Ex8_8_2.pdf
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--- /dev/null
+++ b/2873/CH8/EX8.8/Ex8_8_2.pdf