diff options
| author | priyanka | 2015-06-24 15:03:17 +0530 |
|---|---|---|
| committer | priyanka | 2015-06-24 15:03:17 +0530 |
| commit | b1f5c3f8d6671b4331cef1dcebdf63b7a43a3a2b (patch) | |
| tree | ab291cffc65280e58ac82470ba63fbcca7805165 /551/CH5 | |
| download | Scilab-TBC-Uploads-b1f5c3f8d6671b4331cef1dcebdf63b7a43a3a2b.tar.gz Scilab-TBC-Uploads-b1f5c3f8d6671b4331cef1dcebdf63b7a43a3a2b.tar.bz2 Scilab-TBC-Uploads-b1f5c3f8d6671b4331cef1dcebdf63b7a43a3a2b.zip | |
initial commit / add all books
Diffstat (limited to '551/CH5')
46 files changed, 1145 insertions, 0 deletions
diff --git a/551/CH5/EX5.1/1.sce b/551/CH5/EX5.1/1.sce new file mode 100755 index 000000000..93d135ed7 --- /dev/null +++ b/551/CH5/EX5.1/1.sce @@ -0,0 +1,15 @@ +clc
+Q1=1500/60; //kJ/s
+W=8.2; //kW
+
+disp("(i) Thermal efficiency")
+n=W/Q1;
+disp("n=")
+disp(n)
+
+
+disp("(ii) Rate of heat rejection")
+Q2=Q1-W;
+disp("Q2=")
+disp(Q2)
+disp("kW")
\ No newline at end of file diff --git a/551/CH5/EX5.10/10.sce b/551/CH5/EX5.10/10.sce new file mode 100755 index 000000000..a28d027f5 --- /dev/null +++ b/551/CH5/EX5.10/10.sce @@ -0,0 +1,11 @@ +clc
+one_ton_of_refrigeration=210; //kJ/min
+Cooling_required=40*(one_ton_of_refrigeration); //kJ/min
+T1=303; //K
+T2=238; //K
+COP_refrigerator=T2/(T1-T2);
+COP_actual=0.20*COP_refrigerator;
+W=Cooling_required/COP_actual/60;
+disp("power required = ")
+disp(W)
+disp("kW")
\ No newline at end of file diff --git a/551/CH5/EX5.11/11.sce b/551/CH5/EX5.11/11.sce new file mode 100755 index 000000000..c9c5ff9ef --- /dev/null +++ b/551/CH5/EX5.11/11.sce @@ -0,0 +1,23 @@ +clc
+E=12000; //kJ/min
+
+T2=308; //K
+
+// Source 1
+T1=593; //K
+n1=1-T2/T1;
+
+// Source 2
+T1=343; //K
+n2=1-T2/T1;
+
+W1=E*n1;
+disp("W1 =")
+disp(W1)
+
+W2=E*n2;
+disp("W2 =")
+disp(W2)
+
+disp("Thus, choose source 2.")
+disp("The source 2 is selected even though efficiency in this case is lower, because the criterion for selection is the larger output.")
\ No newline at end of file diff --git a/551/CH5/EX5.12/12.sce b/551/CH5/EX5.12/12.sce new file mode 100755 index 000000000..a85cfbe6d --- /dev/null +++ b/551/CH5/EX5.12/12.sce @@ -0,0 +1,34 @@ +clc
+T1=973; //K
+T2=323; //K
+T3=248; //K
+
+Q1=2500; //kJ
+W=400; //kJ
+
+disp("(i)Heat rejection to the 50°C reservoir")
+n_max=1-T2/T1;
+W1=n_max*Q1;
+COP_max=T3/(T2-T3);
+W2=W1-W;
+Q4=COP_max*W2;
+COP1=Q4/W2;
+Q3=Q4+W2;
+Q2=Q1-W1;
+disp("Heat rejection to the 50°C reservoir=")
+disp(Q2+Q3)
+disp("kJ")
+
+
+disp("(ii)Heat rejected to 50°C reservoir ")
+n=0.45*n_max;
+W1=n*Q1;
+W2=W1-W;
+COP2=0.45*COP1;
+Q4=W2*COP2;
+Q3=Q4+W2;
+Q2=Q1-W1;
+
+disp("Heat rejected to 50°C reservoir=")
+disp(Q2+Q3)
+disp("kJ")
\ No newline at end of file diff --git a/551/CH5/EX5.13/13.sce b/551/CH5/EX5.13/13.sce new file mode 100755 index 000000000..ebace8449 --- /dev/null +++ b/551/CH5/EX5.13/13.sce @@ -0,0 +1,29 @@ +clc
+T1=298; //K
+T2=273; //K
+Q1=24; //kJ/s
+T3=653; //K
+COP=T1/(T1-T2);
+disp("(i) determine COP and work input required")
+
+disp("Coefficient of performance = ")
+disp(COP)
+
+COP_ref=T2/(T1-T2);
+W=Q1/COP_ref;
+disp("Work input required = ")
+disp(W)
+disp("kW")
+
+
+disp("(ii)Determine overall COP of the system ")
+Q4=T1*W/(T3-T1);
+Q3=Q4+W;
+Q2=Q1+W;
+COP=Q1/Q3;
+disp("COP=")
+disp(COP)
+
+COP_overall=(Q2+Q4)/Q3;
+disp("Overall COP=")
+disp(COP_overall)
\ No newline at end of file diff --git a/551/CH5/EX5.14/14.sce b/551/CH5/EX5.14/14.sce new file mode 100755 index 000000000..8ad676512 --- /dev/null +++ b/551/CH5/EX5.14/14.sce @@ -0,0 +1,23 @@ +clc
+T_e1=493; //K
+T_e2=298; //K
+T_p1=298; //K
+T_p2=273; //K
+Amt=15; //tonnes produced per day
+h=334.5; //kJ/kg
+Q_abs=44500; //kJ/kg
+Q_p2=Amt*10^3*h/24/60;
+COP_hp=T_p2/(T_p1-T_p2);
+W=Q_p2/COP_hp/60;
+disp("(i)Power developed by the engine = ")
+disp(W)
+disp("kW")
+
+
+disp("(ii) Fuel consumed per hour")
+n_carnot=1-(T_e2/T_e1);
+Q_e1=W/n_carnot*3600; //kJ/h
+fuel_consumed=Q_e1/Q_abs;
+disp("Quantity of fuel consumed/hour = ")
+disp(fuel_consumed)
+disp("kg/h")
\ No newline at end of file diff --git a/551/CH5/EX5.15/15.sce b/551/CH5/EX5.15/15.sce new file mode 100755 index 000000000..bd1e2c830 --- /dev/null +++ b/551/CH5/EX5.15/15.sce @@ -0,0 +1,10 @@ +clc
+T1=550; //K
+T3=350; //K
+// W=Q2*((T1-T2)/T2)
+// W=Q2((T2-T3)/T2)
+// From this we get following expression
+T2=(T1+T3)/2;
+disp("Intermediate temperature =")
+disp(T2)
+disp("K")
\ No newline at end of file diff --git a/551/CH5/EX5.16/16.sce b/551/CH5/EX5.16/16.sce new file mode 100755 index 000000000..dd7616b6b --- /dev/null +++ b/551/CH5/EX5.16/16.sce @@ -0,0 +1,21 @@ +clc
+T1=600; //K
+T2=300; //K
+
+
+disp("(i) When Q1=Q2")
+T3=2*T1/(T1/T2+1);
+disp("T3=")
+disp(T3)
+disp("K")
+
+
+disp("(ii) Efficiency of Carnot engine and COP of carnot refrigerator")
+n=(T1-T3)/T1; //carnot engine
+COP=T2/(T3-T2); //refrigerator
+
+disp("Efficiency of carnot engine = ")
+disp(n)
+
+disp("COP of carnot refrigerator = ")
+disp(COP)
\ No newline at end of file diff --git a/551/CH5/EX5.17/17.sce b/551/CH5/EX5.17/17.sce new file mode 100755 index 000000000..6f6c3f00a --- /dev/null +++ b/551/CH5/EX5.17/17.sce @@ -0,0 +1,11 @@ +clc
+T3=278; //K
+T2=350; //K
+T4=T2;
+T1=1350; //K
+
+Q1=100/[((T4/T1)*(T1-T2)/(T4-T3))+T2/T1]; //Q4+Q2=100; Q4=Q1*((T4/T1)*(T1-T2)/(T4-T3)); Q2=T2/T1*Q1;
+
+disp("Q1=")
+disp(Q1)
+disp("kJ")
\ No newline at end of file diff --git a/551/CH5/EX5.18/18.sce b/551/CH5/EX5.18/18.sce new file mode 100755 index 000000000..67e830809 --- /dev/null +++ b/551/CH5/EX5.18/18.sce @@ -0,0 +1,22 @@ +clc
+Q1=300; //kJ/s
+T1=290; //0C
+T2=8.5; //0C
+disp("let ΣdQ/T = A")
+
+disp("(i) 215 kJ/s are rejected")
+Q2=215; //kJ/s
+A= Q1/(T1+273) - Q2/(T2+273)
+disp("Since, A<0, Cycle is irreversible.")
+
+
+disp("(ii) 150 kJ/s are rejected")
+Q2=150; //kJ/s
+A= Q1/(T1+273) - Q2/(T2+273)
+disp("Since A=0, cycle is reversible")
+
+
+disp("(iii) 75 kJ/s are rejected.")
+Q2=75; //kJ/s
+A= Q1/(T1+273) - Q2/(T2+273)
+disp("Since A>0, cycle is impossible")
\ No newline at end of file diff --git a/551/CH5/EX5.19/19.sce b/551/CH5/EX5.19/19.sce new file mode 100755 index 000000000..4b5c65c31 --- /dev/null +++ b/551/CH5/EX5.19/19.sce @@ -0,0 +1,14 @@ +clc
+P1=0.124*10^5; //N/m^2
+T1=433; //K
+T2=323; //K
+h_f1=687; //kJ/kg
+h2=2760; //kJ/kg
+h3=2160; //kJ/kg
+h_f4=209; //kJ/kg
+Q1=h2-h_f1;
+Q2=h_f4-h3;
+disp("Let A=ΣdQ/T")
+A=Q1/T1+Q2/T2;
+disp(A)
+disp("A<0. Hence classius inequality is verified")
\ No newline at end of file diff --git a/551/CH5/EX5.2/2.sce b/551/CH5/EX5.2/2.sce new file mode 100755 index 000000000..d8047f9ed --- /dev/null +++ b/551/CH5/EX5.2/2.sce @@ -0,0 +1,9 @@ +clc
+Q_12=30; //kJ
+W_12=60; //kJ
+dU_12=Q_12-W_12;
+Q_21=0;
+W_21=Q_21+dU_12;
+disp("W_21 =")
+disp(W_21)
+disp("Thus 30 kJ work has to be done on the system to restore it to original state, by adiabatic process.")
\ No newline at end of file diff --git a/551/CH5/EX5.20/20.sce b/551/CH5/EX5.20/20.sce new file mode 100755 index 000000000..88b1aee37 --- /dev/null +++ b/551/CH5/EX5.20/20.sce @@ -0,0 +1,15 @@ +clc
+T1=437; //K
+T2=324; //K
+h2=2760; //kJ/kg
+h1=690; //kJ/kg
+h3=2360; //kJ/kg
+h4=450; //kJkg
+
+Q1=h2-h1;
+Q2=h4-h3;
+
+disp("Let A=ΣdQ/T")
+A=Q1/T1 + Q2/T2;
+disp(A)
+disp("Since A<0, Classius inequality is verified")
\ No newline at end of file diff --git a/551/CH5/EX5.21/21.sce b/551/CH5/EX5.21/21.sce new file mode 100755 index 000000000..5f7e6bcd9 --- /dev/null +++ b/551/CH5/EX5.21/21.sce @@ -0,0 +1,20 @@ +clc
+T0=273; //K
+T1=673; //K
+T2=298; //K
+m_w=10; //kg
+T3=323; //K
+c_pw=4186; //kJ/kg.K
+disp("Let C=mi*cpi")
+C=m_w*c_pw*(T3-T2)/(T1-T3);
+
+S_iT1=C*log(T1/T0); // Entropy of iron at 673 K
+S_wT2=m_w*c_pw*log(T2/T0); //Entropy of water at 298 K
+S_iT3=C*log(T3/T0); //Entropy of iron at 323 K
+S_wT3=m_w*c_pw*log(T3/T0); //Entropy of water at 323 K
+
+dS_i=S_iT3 - S_iT1;
+dS_w=S_wT3 - S_wT2;
+dS_net=dS_i + dS_w
+
+disp("Since dS>0, process is irreversible")
\ No newline at end of file diff --git a/551/CH5/EX5.23/23.sce b/551/CH5/EX5.23/23.sce new file mode 100755 index 000000000..0c782dcb9 --- /dev/null +++ b/551/CH5/EX5.23/23.sce @@ -0,0 +1,30 @@ +clc
+T1=293; //K
+V1=0.025; //m^3
+V3=V1;
+p1=1.05*10^5; //N/m^2
+p2=4.5*10^5; //N/m^2
+R=0.287*10^3;
+cv=0.718;
+cp=1.005;
+T3=293; //K
+
+disp("(i)Net heat flow")
+m=p1*V1/R/T1;
+T2=p2/p1*T1;
+Q_12=m*cv*(T2-T1);
+Q_23=m*cp*(T3-T2)
+
+disp("Net heat flow = ")
+Q_net=Q_12+Q_23;
+disp(Q_net)
+disp("kJ")
+
+
+disp("(ii) Net entropy change")
+dS_32=m*cp*log(T2/T1);
+dS_12=m*cv*log(T2/T1);
+dS_31=dS_32 - dS_12;
+disp("Decrease in entropy = ")
+disp(dS_31)
+disp("kJ/K")
\ No newline at end of file diff --git a/551/CH5/EX5.24/24.sce b/551/CH5/EX5.24/24.sce new file mode 100755 index 000000000..100ce8a93 --- /dev/null +++ b/551/CH5/EX5.24/24.sce @@ -0,0 +1,70 @@ +clc
+p1=1.05*10^5; //N/m^2
+V1=0.04; //m^3
+T1=288; //K
+p2=4.8*10^5;
+T2=T1;
+R0=8314;
+M=28;
+
+
+disp("(i) The change of entropy =")
+R=R0/M;
+m=p1*V1/R/T1;
+dS=m*R*log(p1/p2)
+disp("Decrease in entropy =")
+disp(-dS)
+disp("J/K")
+
+
+disp("(ii)Heat rejected = ")
+Q=T1*(-dS);
+disp("Q=")
+disp(Q)
+disp("J")
+
+
+W=Q;
+disp("Work done = ")
+disp(W)
+disp("J")
+
+V2=p1*V1/p2;
+v1=V1/m; //specific volume
+v2=V2/m; //specific volume
+
+v=v2:0.01:v1;
+function p=f(v)
+ p=p1*v1/v
+endfunction
+
+plot(v,f)
+
+p=p1
+plot(v,p,'--')
+
+p=[0 p2]
+v=[v2 v2]
+plot(v,p,'--')
+
+p=[0 p1]
+v=[v1 v1]
+plot(v,p,'--')
+
+xtitle("p-v diagram", "v(m^3/kg)", "p(N/m^2)")
+
+xset('window', 1)
+
+T=[288 288]
+s=[10 (10-dS)]
+plot(s,T)
+
+s=[10 10]
+T=[0 288]
+plot(s,T,'--')
+
+s=[(10-dS) (10-dS)]
+T=[0 288]
+plot(s,T,'--')
+
+xtitle("T-s diagram", "s(kJ/kg K)", "T(K)")
\ No newline at end of file diff --git a/551/CH5/EX5.25/25.sce b/551/CH5/EX5.25/25.sce new file mode 100755 index 000000000..3185d6c39 --- /dev/null +++ b/551/CH5/EX5.25/25.sce @@ -0,0 +1,11 @@ +clc
+R=287; //kJ/kg.K
+dU=0;
+W=0;
+Q=dU+W;
+
+dS=R*log(2); //v2/v1=2
+
+disp("Change in entropy = ")
+disp(dS)
+disp("kJ/kg.K")
\ No newline at end of file diff --git a/551/CH5/EX5.26/26.sce b/551/CH5/EX5.26/26.sce new file mode 100755 index 000000000..0110b683f --- /dev/null +++ b/551/CH5/EX5.26/26.sce @@ -0,0 +1,19 @@ +clc
+m=0.04; //kg
+p1=1*10^5; //N/m^2
+T1=293; //K
+p2=9*10^5; //N/m^2
+V2=0.003; //m^3
+cp=0.88; //kJ/kg.K
+R0=8314;
+M=44;
+
+R=R0/M;
+T2=p2*V2/m/R;
+ds_2A=R/10^3*log(p2/p1);
+ds_1A=cp*log(T2/T1);
+ds_21=ds_2A - ds_1A;
+dS_21=m*ds_21;
+disp("Decrease in entropy=")
+disp(dS_21)
+disp("kJ/K")
\ No newline at end of file diff --git a/551/CH5/EX5.27/27.sce b/551/CH5/EX5.27/27.sce new file mode 100755 index 000000000..463bd18bc --- /dev/null +++ b/551/CH5/EX5.27/27.sce @@ -0,0 +1,21 @@ +clc
+p1=7*10^5; //N/m^2
+T1=873; //K
+p2=1.05*10^5; //N/M62
+n=1.25;
+m=1; //kg
+R=0.287;
+cp=1.005;
+T2=T1*(p2/p1)^((n-1)/n);
+
+// At constant temperature from 1 to A
+ds_1A=R*log(p1/p2);
+
+// At constant pressure from A to 2
+ds_2A=cp*log(T1/T2);
+
+
+ds_12=ds_1A - ds_2A;
+disp("Increase in entropy = ")
+disp(ds_12)
+disp("kJ/kg.K")
\ No newline at end of file diff --git a/551/CH5/EX5.28/28.sce b/551/CH5/EX5.28/28.sce new file mode 100755 index 000000000..92e830c06 --- /dev/null +++ b/551/CH5/EX5.28/28.sce @@ -0,0 +1,20 @@ +clc
+p1=7*10^5; //Pa
+T1=733; //K
+p2=1.012*10^5; //Pa
+T2a=433; //K
+y=1.4;
+cp=1.005;
+
+disp("(i) To prove that the process is irreversible")
+T2=T1*(p2/p1)^((y-1)/y);
+disp("T2 =")
+disp(T2)
+disp("But the actual temperature is 433K at th epressure of 1.012 bar, Hence the process is irreversible. Proved.")
+
+
+disp("(ii) Change of entropy per kg of air")
+ds=cp*log(T2a/T2);
+disp("Increase of entropy=")
+disp(ds)
+disp("kJ/kg.K")
\ No newline at end of file diff --git a/551/CH5/EX5.29/29.sce b/551/CH5/EX5.29/29.sce new file mode 100755 index 000000000..683ec0905 --- /dev/null +++ b/551/CH5/EX5.29/29.sce @@ -0,0 +1,38 @@ +clc
+V1=0.3; //m^3
+p1=4*10^5; //N/m^2
+V2=0.08; //m^3
+n=1.25;
+p2=p1*(V1/V2)^n;
+
+disp("(i) Change in enthalpy")
+dH=n*(p2*V2-p1*V1)/(n-1)/10^3;
+disp("dH=")
+disp(dH)
+disp("kJ")
+
+
+disp("(ii) Change in internal energy")
+dU=dH-(p2*V2 - p1*V1)/10^3;
+disp("dU=")
+disp(dU)
+disp("kJ")
+
+
+disp("(iii) Change in entropy")
+dS=0;
+disp("dS")
+disp(dS)
+
+
+disp("(iv)Heat transfer")
+Q=0;
+disp("Q=")
+disp(Q)
+
+
+disp("(v) Work transfer")
+W=Q-dU;
+disp("W=")
+disp(W)
+disp("kJ")
\ No newline at end of file diff --git a/551/CH5/EX5.3/3.sce b/551/CH5/EX5.3/3.sce new file mode 100755 index 000000000..17fc79b34 --- /dev/null +++ b/551/CH5/EX5.3/3.sce @@ -0,0 +1,11 @@ +clc
+Q2=12000; //kJ/h
+W=0.75*60*60; //kJ/h
+COP=Q2/W;
+disp("Coefficient of performance")
+disp(COP)
+
+Q1=Q2+W;
+disp("heat transfer rate=")
+disp(Q1)
+disp("kJ/h")
\ No newline at end of file diff --git a/551/CH5/EX5.30/30.sce b/551/CH5/EX5.30/30.sce new file mode 100755 index 000000000..7a23f05f0 --- /dev/null +++ b/551/CH5/EX5.30/30.sce @@ -0,0 +1,36 @@ +clc
+m=20; //kg
+p1=4*10^5; //Pa
+p2=8*10^5; //Pa
+V1=4; //m^3
+V2=V1;
+cp=1.04; //kJ/kg.K
+cv=0.7432; //kJ/kg.K
+R=cp-cv;
+T1=p1*V1/R/1000; //kg.K; T=mass*temperature
+T2=p2*V2/R/1000; //kg.K
+
+
+disp("(i) Change in internal energy")
+dU=cv*(T2-T1);
+disp("dU=")
+disp(dU)
+disp("kJ")
+
+
+disp("(ii) Work done")
+Q=0;
+W=Q-dU;
+disp("W")
+disp(W)
+disp("kJ")
+
+
+disp("(iii) Heat transferred = ")
+disp(Q)
+
+
+disp("(iv) Change in entropy =")
+dS=m*cv*log(T2/T1);
+disp(dS)
+disp("kJ/K")
\ No newline at end of file diff --git a/551/CH5/EX5.31/31.sce b/551/CH5/EX5.31/31.sce new file mode 100755 index 000000000..c08d4b123 --- /dev/null +++ b/551/CH5/EX5.31/31.sce @@ -0,0 +1,33 @@ +clc
+V1=5; //m^3
+p1=2*10^5; //Pa
+T1=300; //K
+p2=6*10^5; //Pa
+p3=2*10^5; //Pa
+R=287;
+n=1.3;
+y=1.4;
+
+m=p1*V1/R/T1;
+T2=T1*(p2/p1)^((n-1)/n);
+T3=T2*(p3/p2)^((y-1)/y);
+W_12=m*R*(T1-T2)/(n-1)/1000; //polytropic compression
+W_23=m*R*(T2-T3)/(y-1)/1000; //Adiabatic expansion
+
+W_net=W_12+W_23;
+disp("Net work done on the air = ")
+disp(-W_net)
+
+T=[T1 310 320 330 340 350 360 370 380 T2];
+function s=f(T)
+ s=(y-n)/(y-1)/(1-n)*R/10^3*log(T);
+endfunction
+s=[f(T1) f(310) f(320) f(330) f(340) f(350) f(360) f(370) f(380) f(T2)]
+plot(s,T)
+
+T=[T2 T3];
+s=[f(T2) f(T2)];
+plot(s,T,'r')
+
+xtitle("T-s diagram", "s(kJ/kg K)", "T(K)")
+legend("p*v^1.3=constant", "p*v^y=constant")
\ No newline at end of file diff --git a/551/CH5/EX5.32/32.sce b/551/CH5/EX5.32/32.sce new file mode 100755 index 000000000..93a258f82 --- /dev/null +++ b/551/CH5/EX5.32/32.sce @@ -0,0 +1,25 @@ +clc
+V1=0.004; //m^3
+p1=1*10^5; //Pa
+T1=300; //K
+T2=400; //K
+y=1.4;
+M=28;
+R0=8.314;
+R=R0/M;
+
+
+disp("(i) The heat supplied")
+m=p1*V1/R/1000/T1; //kg
+cv=R/(y-1);
+Q=m*cv*(T2-T1);
+disp("Q")
+disp(Q)
+disp("kJ")
+
+
+disp("(ii) The entropy change")
+dS=m*cv*log(T2/T1);
+disp("dS=")
+disp(dS)
+disp("kJ/kg.K")
\ No newline at end of file diff --git a/551/CH5/EX5.33/33.sce b/551/CH5/EX5.33/33.sce new file mode 100755 index 000000000..ebc9d1591 --- /dev/null +++ b/551/CH5/EX5.33/33.sce @@ -0,0 +1,23 @@ +clc
+V1=0.05; //m^3
+p1=1*10^5; //Pa
+T1=280; //K
+p2=5*10^5; //Pa
+
+disp("(i) Change in entropy")
+R0=8.314;
+M=28;
+R=R0/M;
+m=p1*V1/R/T1/1000;
+
+
+dS=m*R*log(p1/p2);
+disp("dS=")
+disp(dS)
+disp("kJ/K")
+
+disp("(ii)Work done")
+Q=T1*dS;
+disp("Q=")
+disp(Q)
+disp("kJ")
\ No newline at end of file diff --git a/551/CH5/EX5.34/34.sce b/551/CH5/EX5.34/34.sce new file mode 100755 index 000000000..27d917859 --- /dev/null +++ b/551/CH5/EX5.34/34.sce @@ -0,0 +1,43 @@ +clc
+R=0.287; //kJ/kg.K
+m=1; //kg
+p1=8*10^5; //Pa
+p2=1.6*10^5; //Pa
+T1=380; //K
+n=1.2;
+y=1.4;
+
+
+disp("(i) Final specific volume and temperature")
+v1=R*T1/p1*10^3; //m^3/kg
+v2=v1*(p1/p2)^(1/n);
+T2=T1*(p2/p1)^((n-1)/n);
+disp("v2=")
+disp(v2)
+disp("m^3/kg")
+disp("T2=")
+disp(T2)
+
+
+disp("(ii) Change of internal energy, work done and heat interaction")
+dU=R/(y-1)*(T2-T1);
+disp("dU=")
+disp(dU)
+disp("kJ/kg")
+
+W=R*(T1-T2)/(n-1);
+disp("W=")
+disp(W)
+disp("kJ/kg")
+
+Q=dU + W;
+disp("Q=")
+disp(Q)
+disp("kJ/kg")
+
+
+disp("(iii) Change in entropy")
+dS=R/(y-1)*log(T2/T1) + R*log(v2/v1)
+disp("dS=")
+disp(dS)
+disp("kJ/kg.K")
\ No newline at end of file diff --git a/551/CH5/EX5.35/35.sce b/551/CH5/EX5.35/35.sce new file mode 100755 index 000000000..a8c2d3501 --- /dev/null +++ b/551/CH5/EX5.35/35.sce @@ -0,0 +1,56 @@ +clc
+y=1.4;
+cv=0.718; //kJ/kg.K
+m=1; //kg
+T1=290; //K
+n=1.3;
+r=16;
+y=1.4;
+
+T2=T1*(r)^(n-1);
+
+disp("(a)")
+
+T=[T1 300 310 320 330 340 350 360 370 380 390 400 410 420 430 440 450 460 470 480 490 500 510 520 530 540 550 560 570 580 590 600 610 620 630 640 650 660 T2];
+function s=f(T)
+ s=(y-n)*cv/(1-n)/10^3*log(T);
+endfunction
+s=[f(T1) f(300) f(310) f(320) f(330) f(340) f(350) f(360) f(370) f(380) f(390) f(400) f(410) f(420) f(430) f(440) f(450) f(460) f(470) f(480) f(490) f(500) f(510) f(520) f(530) f(540) f(550) f(560) f(570) f(580) f(590) f(600) f(610) f(620) f(630) f(640) f(650) f(660) f(T2)];
+plot(s,T)
+
+T=[0 T2];
+s=[f(T2) f(T2)];
+plot(s,T,'r--')
+
+T=[0 T1];
+s=[f(T1) f(T1)];
+plot(s,T,'r--')
+
+T=[T1 T2];
+s=[f(T1) f(T2)];
+plot(s,T,'r--')
+
+xtitle("T-s diagram", "s", "T")
+legend("p*v^n=c")
+
+//Heat transferred = Area of trapezium = Base*mean ordinate
+
+//Heat transferred=dS*(T1+T2)/2
+//Hence we get
+disp("Entropy change=Heat transferred/Mean absolute temperature")
+
+disp("(b)Entropy change")
+dS=cv*((n-y)/(n-1))*log(T2/T1);
+disp("dS=")
+disp(dS)
+disp("kJ/kg.K")
+disp("There is decrease in entropy")
+
+Q=cv*((y-n)/(n-1))*(T1-T2);
+Tmean = (T1+T2)/2;
+dS_app=Q/Tmean;
+
+%error=((-dS) - (-dS_app))/(-dS) * 100;
+disp("%age error =")
+disp(%error)
+disp("%")
\ No newline at end of file diff --git a/551/CH5/EX5.36/36.sce b/551/CH5/EX5.36/36.sce new file mode 100755 index 000000000..a26251453 --- /dev/null +++ b/551/CH5/EX5.36/36.sce @@ -0,0 +1,47 @@ +clc
+cp=1.005; //kJ/kg.K
+R=0.287; //kJ/kg.K
+V1=1.2; //m^3
+p1=1*10^5; //Pa
+p2=p1;
+T1=300; //K
+T2=600; //K
+T3=T1;
+p1=1*10^5; //Pa
+cv=cp-R;
+
+disp("(i) The net heat flow")
+m=p1*V1/R/1000/T1; //kg
+Q=m*R*(T2-T1);
+disp("Q=")
+disp(Q)
+disp("kJ")
+
+
+disp("(ii) The overall change in entropy")
+dS_12=m*cp*log(T2/T1);
+dS_23=m*(cp-R)*log(T3/T2); //cv=cp-R
+dS_overall=dS_12+dS_23;
+disp("Overall change in entropy=")
+disp(dS_overall)
+disp("kJ/K")
+
+
+s=sqrt(300):0.1:sqrt(600);
+T=s^2;
+plot(s,T)
+
+s=22.18:0.1:sqrt(600);
+T=10*(s-16.725)^2;
+plot(s,T,'r')
+
+s=[17 25];
+T=[600 600];
+plot(s,T,'--')
+
+s=[17 25];
+T=[300 300];
+plot(s,T,'--')
+
+xtitle("T-s diagram", "S", "T")
+legend("p=C", "V=C")
diff --git a/551/CH5/EX5.37/37.sce b/551/CH5/EX5.37/37.sce new file mode 100755 index 000000000..a6d8a66cc --- /dev/null +++ b/551/CH5/EX5.37/37.sce @@ -0,0 +1,68 @@ +clc
+cv=0.718; //kJ/kg.K
+R=0.287; //kJ/kg.K
+p1=1*10^5; //Pa
+T1=300; //K
+V1=0.018; //m^3
+p2=5*10^5; //Pa
+T3=T1;
+cp=cv+R;
+p3=p2;
+
+m=p1*V1/R/T1/1000; //kg
+T2=T1*p2/p1;
+
+disp("(i) constant volume process")
+disp("dS=")
+dS_12=m*cv*log(T2/T1);
+disp(dS_12)
+disp("kJ/K")
+
+disp("(ii) Constant prssure process ")
+disp("dS=")
+dS_23=m*cp*log(T3/T2);
+disp(dS_23)
+disp("kJ/K")
+
+disp("(iii) Isothermal process")
+disp("dS=")
+dS_31=m*R*log(p3/p1);
+disp(dS_31)
+disp("kJ/K")
+
+disp("T-s diagram")
+s=sqrt(300):0.1:sqrt(600);
+T=s^2;
+plot(s,T)
+
+s=22.18:0.1:sqrt(600);
+T=10*(s-16.725)^2;
+plot(s,T,'r')
+
+s=[sqrt(300) 22.18];
+T=[300 300];
+plot(s,T,'g')
+
+xtitle("T-s diagram", "S", "T")
+legend("p=C", "V=C", "T=C")
+
+disp("p-V diagram")
+xset('window',1)
+
+V=[0.018 0.018];
+p=[1 5];
+plot(V,p)
+
+p=[5 5];
+V=[0.0036 0.018];
+plot(V,p,'r')
+
+V=0.0036:0.0001:0.018;
+function p=f(V)
+ p=1*0.018/V;
+endfunction
+
+plot(V,f,'g')
+
+xtitle("p-V diagram", "V", "p")
+legend("V=C","p=C","T=C")
\ No newline at end of file diff --git a/551/CH5/EX5.39/39.sce b/551/CH5/EX5.39/39.sce new file mode 100755 index 000000000..ba991b137 --- /dev/null +++ b/551/CH5/EX5.39/39.sce @@ -0,0 +1,9 @@ +clc
+m=4; //kg
+T1=400; //K
+T2=500; //K
+
+dS=integrate('m*(0.48+0.0096*T)/T', 'T', T1,T2);
+disp("dS=")
+disp(dS)
+disp("kJ")
\ No newline at end of file diff --git a/551/CH5/EX5.4/4.sce b/551/CH5/EX5.4/4.sce new file mode 100755 index 000000000..3c137f740 --- /dev/null +++ b/551/CH5/EX5.4/4.sce @@ -0,0 +1,10 @@ +clc
+T2=261; //K
+T1=308; //K
+Q2=2; //kJ/s
+Q1=Q2*(T1/T2);
+W=Q1-Q2;
+
+disp("Least power required to pump the heat continuosly")
+disp(W)
+disp("kW")
\ No newline at end of file diff --git a/551/CH5/EX5.40/40.sce b/551/CH5/EX5.40/40.sce new file mode 100755 index 000000000..a16ab29fd --- /dev/null +++ b/551/CH5/EX5.40/40.sce @@ -0,0 +1,13 @@ +clc
+p1=1*10^5; //Pa
+T1=273; //K
+p2=25*10^5; //Pa
+T2=750; //K
+R=0.29; //kJ/kg.K ; cp=0.85+0.00025*T; cv=0.56+0.00025*T; R=cp-cv;
+v2=R*T2/p2;
+v1=R*T1/p1;
+ds=integrate('(0.56+0.00025*T)/T', 'T', T1, T2) + integrate('R/v', 'v', v1, v2);
+
+disp("ds=")
+disp(ds)
+disp("kJ/kg K")
\ No newline at end of file diff --git a/551/CH5/EX5.41/41.sce b/551/CH5/EX5.41/41.sce new file mode 100755 index 000000000..6f8f41ce1 --- /dev/null +++ b/551/CH5/EX5.41/41.sce @@ -0,0 +1,39 @@ +clc
+cv=0.715; //kJ/kg K
+R=0.287; //kJ/kg K
+V_A=0.25; //m^3
+p_Ai=1.4; //bar
+T_Ai=290; //K
+V_B=0.25; //m^3
+p_Bi=4.2; //bar
+T_Bi=440; //K
+
+disp("(i) Final equilibrium temperature")
+m_A=p_Ai * 10^5 * V_A / R / 1000/ T_Ai; //kg
+m_B=p_Bi * 10^5 * V_B / R / 1000/ T_Bi; //kg
+
+T_f=(m_B * T_Bi + m_A * T_Ai)/(m_A + m_B);
+disp("T_f = ")
+disp(T_f)
+disp("K")
+
+
+disp("(ii) Final pressure on each side of the diaphragm")
+p_Af=p_Ai*T_f/T_Ai;
+disp("p_Af=")
+disp(p_Af)
+disp("bar")
+
+p_Bf=p_Bi*T_f/T_Bi;
+disp("p_Bf=")
+disp(p_Bf)
+disp("bar")
+
+
+disp("(iii) Entropy change of the system")
+dS_A=m_A*cv*log(T_f/T_Ai);
+dS_B=m_B*cv*log(T_f/T_Bi);
+dS_net=dS_A+dS_B;
+disp("Net change of entropy=")
+disp(dS_net)
+disp("kJ/K")
\ No newline at end of file diff --git a/551/CH5/EX5.42/42.sce b/551/CH5/EX5.42/42.sce new file mode 100755 index 000000000..e942b6209 --- /dev/null +++ b/551/CH5/EX5.42/42.sce @@ -0,0 +1,21 @@ +clc
+cv=1.25; //kJ/kg.K
+T1=530; //K
+v1=0.0624; //m^3/kg
+v2=0.186; //m^3/kg
+dT_31=25; //K
+T3=T1-dT_31; //K
+dT_21=165; //K
+T2=T1-dT_21; //K
+// Path 1-2 : Reversible adiabatic process
+ds_12=0;
+
+// To calculate (s3–s1) a reversible path has to be selected joining 3 and 1.This is achieved by selecting the reversible adiabatic path 1-2 and the reversible constant volume process 2-3.
+
+// Path 1-3 : Adiabatic process
+v3=0.186; //m^3/kg
+v3=v2;
+ds_13=cv*log(T3/T2);
+disp("Chang in entropy = ")
+disp(ds_13)
+disp("kJ/kgK")
\ No newline at end of file diff --git a/551/CH5/EX5.44/44.sce b/551/CH5/EX5.44/44.sce new file mode 100755 index 000000000..d5ac87f49 --- /dev/null +++ b/551/CH5/EX5.44/44.sce @@ -0,0 +1,47 @@ +clc
+T1=500; //K
+T2=400; //K
+T3=300; //K
+Q1=1500; //kJ/min
+W=200; //kJ/min
+
+//Q1/T1 + Q2/T2 + Q3/T3=0
+//Q1+Q2+Q3=W
+//For solving the above two equations we use following method
+//Q2-Q3=-1300
+//Q2/400 - Q3/300 =-1500/500=-3
+
+A=[1,-1;(1/400),(-1/300)];
+B=[(-1300);(-3)];
+X=inv(A)*B;
+Q2=X(1,1);
+disp("Q2 =")
+disp(Q2)
+disp("kJ/min")
+
+Q3=X(2,1);
+disp("Q3 =")
+disp(Q3)
+disp("kJ/min")
+
+disp("(ii) Entropy change ")
+dS1=(-Q1)/T1;
+disp("Entropy change of source 1 =")
+disp(dS1)
+disp("kJ/K")
+
+dS2=(-Q2)/T2;
+disp("Entropy change of sink 2 =")
+disp(dS2)
+disp("kJ/K")
+
+dS3=Q3/T3;
+disp("Entropy change of source 3 =")
+disp(dS3)
+disp("kJ/K")
+
+
+disp("(iii) Net change of the entropy")
+dSnet = dS1 + dS2 + dS3;
+disp("dSnet=")
+disp(dSnet)
\ No newline at end of file diff --git a/551/CH5/EX5.45/45.sce b/551/CH5/EX5.45/45.sce new file mode 100755 index 000000000..c243d8bf3 --- /dev/null +++ b/551/CH5/EX5.45/45.sce @@ -0,0 +1,17 @@ +clc
+T1=250; //K
+T2=125; //K
+//cv=0.0045*T^2
+Q1=integrate('0.045*T^2', 'T', T1, T2);
+dS_system=integrate('0.045*T', 'T', T1, T2);
+
+//dS_reservoir=(Q1-W)/T_resservoir
+
+//dS_universe >= 0
+//But for maximum work done dS_universe=0
+dS_universe=0;
+
+W_max=((-Q1) -T2*(dS_universe-dS_system))/1000;
+disp("W_max=")
+disp(W_max)
+disp("kJ")
\ No newline at end of file diff --git a/551/CH5/EX5.46/46.sce b/551/CH5/EX5.46/46.sce new file mode 100755 index 000000000..d2a33864d --- /dev/null +++ b/551/CH5/EX5.46/46.sce @@ -0,0 +1,16 @@ +clc
+cp=1.005; //kJ/kg K
+T_A=333; //K
+T_B=288; //K
+p_A=140; //kPa
+p_B=110; //kPa
+//h=cp*T
+//v/T=0.287/p
+ds_system=integrate('cp/T', 'T', T_A, T_B) + integrate('0.287/p', 'p', p_A, p_B);
+ds_surr=0;
+ds_universe=ds_system+ds_surr;
+disp("change in entropy of universe = ")
+disp(ds_universe)
+disp("kJ/kgK")
+disp("Since change in entropy of universe from A to B is -ve")
+disp("The flow is from B to A")
\ No newline at end of file diff --git a/551/CH5/EX5.47/47.sce b/551/CH5/EX5.47/47.sce new file mode 100755 index 000000000..5baf3735a --- /dev/null +++ b/551/CH5/EX5.47/47.sce @@ -0,0 +1,14 @@ +clc
+m1=3; //kg
+m2=4; //kg
+T0=273; //K
+T1=80+273; //K
+T2=15+273; //K
+c_pw=4.187; //kJ/kgK
+tm=(m1*T1 + m2*T2)/(m1+m2);
+Si=m1*c_pw*log(T1/T0) + m2*c_pw*log(T2/T0);
+Sf=(m1+m2)*c_pw*log(tm/T0);
+dS=Sf-Si;
+disp("Net change in entropy =")
+disp(dS)
+disp("kJ/K")
\ No newline at end of file diff --git a/551/CH5/EX5.49/49.sce b/551/CH5/EX5.49/49.sce new file mode 100755 index 000000000..741bf0fe0 --- /dev/null +++ b/551/CH5/EX5.49/49.sce @@ -0,0 +1,40 @@ +clc +m=1; //kg +T1=273; //K +T2=363; //K +c=4.187; + +disp("(a)") +disp("(i) Entropy of water=") +ds_water=m*c*log(T2/T1); +disp(ds_water) +disp("kJ/kgK") + + +disp("(ii) Entropy change of the reservoir ") +Q=m*c*(T2-T1); +ds_reservoir=-Q/T2; +disp("ds_reservoir=") +disp(ds_reservoir) +disp("kJ/K") + + +disp("(iii) Entropy change of universe =") +ds_universe=ds_water+ds_reservoir; +disp(ds_universe) +disp("kJ/K") + + +disp("(b)") +T3=313; //K +ds_water=m*c*(log(T3/T1) + log(T2/T3)); +ds_res1=-m*c*(T3-T1)/T3; +ds_res2=-m*c*(T2-T3)/T2; + +ds_universe=ds_water+ds_res1+ds_res2; +disp("(iii) Entropy change of universe =") +disp(ds_universe) +disp("kJ/K") + +disp("(c) The entropy change of universe would be less and less, if the water is heated in more and more stages, by bringing the water in contact successively with more and more heat reservoirs, each succeeding reservoir being at a higher temperature than the preceding one.") +disp("When water is heated in infinite steps, by bringing in contact with an infinite number of reservoirs in succession, so that at any instant the temperature difference between the water and the reservoir in contact is infinitesimally small, then the entropy change of the universe would be zero and the water would be reversibly heated.")
\ No newline at end of file diff --git a/551/CH5/EX5.5/5.sce b/551/CH5/EX5.5/5.sce new file mode 100755 index 000000000..07398f3b1 --- /dev/null +++ b/551/CH5/EX5.5/5.sce @@ -0,0 +1,15 @@ +clc
+
+disp("(i) Heat abstracted from outside=")
+Q1=2*10^5; //kJ/h
+W=3*10^4; //kJ/h
+Q2=Q1-W;
+disp("Heat abstracted from outside=")
+disp(Q2)
+disp("kJ/h")
+
+
+disp("(ii) Co-efficient of performance")
+COP_hp=Q1/(Q1-Q2);
+disp("Co-efficient of performance=")
+disp(COP_hp)
\ No newline at end of file diff --git a/551/CH5/EX5.50/50.sce b/551/CH5/EX5.50/50.sce new file mode 100755 index 000000000..24ba8cb3c --- /dev/null +++ b/551/CH5/EX5.50/50.sce @@ -0,0 +1,42 @@ +clc
+cp=2.093; //kJ/kg0C
+c=4.187;
+Lf=333.33; //kJ/kg
+m=1; //kg
+T0=273; //K
+T1=268; //K
+T2=298; //K
+Q_s=m*cp*(T0-T1);
+Q_f=m*Lf;
+Q_l=m*c*(T2-T0);
+Q=Q_s+Q_f+Q_l;
+
+disp("(i) Entropy increase of the universe")
+ds_atm=-Q/T2;
+ds_sys1=m*cp*log(T0/T1);
+ds_sys2=Lf/T0;
+ds_sys3=m*c*log(T2/T0);
+ds_total=ds_sys1+ds_sys2+ds_sys3;
+ds_universe=ds_total+ds_atm;
+
+disp("Entropy increase of universe=")
+disp(ds_universe)
+disp("kJ/K")
+
+
+disp("(ii) Minimum amount of work necessary to convert the water back into ice at – 5°C, Wmin.")
+dS_refrigerator=0;
+
+// dS_atm=(Q+W)/T;
+// dS_universe >= 0
+// dS_system=(s1-s4)
+//dS_universe=dS_system+dS_refrigerator+dS_atm
+
+dS_system=-1.6263; //kJ/kg K
+T=298; //K
+
+//For minimum work
+W_min=T*(-dS_system)-Q;
+disp("Minimum work done =")
+disp(W_min)
+disp("kJ")
\ No newline at end of file diff --git a/551/CH5/EX5.6/6.sce b/551/CH5/EX5.6/6.sce new file mode 100755 index 000000000..d5af0af79 --- /dev/null +++ b/551/CH5/EX5.6/6.sce @@ -0,0 +1,7 @@ +clc
+T1=2373; //K
+T2=288; //K
+n_max=1-T2/T1;
+disp("Highest possible theoritical efficiency=")
+disp(n_max*100)
+disp("%")
\ No newline at end of file diff --git a/551/CH5/EX5.7/7.sce b/551/CH5/EX5.7/7.sce new file mode 100755 index 000000000..c546f811e --- /dev/null +++ b/551/CH5/EX5.7/7.sce @@ -0,0 +1,23 @@ +clc
+T1=523; //K
+T2=258; //K
+Q1=90; //kJ
+
+n=1-T2/T1;
+disp("(i) Efficiency of the system")
+disp(n*100)
+disp("%")
+
+
+disp("(ii) The net work transfer")
+W=n*Q1;
+disp("W=")
+disp(W)
+disp("kJ")
+
+
+disp("(iii) Heat rejected to the sink")
+Q2=Q1-W;
+disp("Q2=")
+disp(Q2)
+disp("kJ")
\ No newline at end of file diff --git a/551/CH5/EX5.8/8.sce b/551/CH5/EX5.8/8.sce new file mode 100755 index 000000000..0e3710adf --- /dev/null +++ b/551/CH5/EX5.8/8.sce @@ -0,0 +1,14 @@ +clc
+T1=1023; //K
+T2=298; //K
+n_carnot=1-T2/T1;
+W=75*1000*60*60;
+Q=3.9*74500*1000;
+n_thermal=W/Q;
+disp("n_carnot =")
+disp(n_carnot)
+
+disp("n_thermal =")
+disp(n_thermal)
+
+disp("Since ηthermal > ηcarnot, therefore claim of the inventor is not valid (or possible")
\ No newline at end of file diff --git a/551/CH5/EX5.9/9.sce b/551/CH5/EX5.9/9.sce new file mode 100755 index 000000000..b9ecf0245 --- /dev/null +++ b/551/CH5/EX5.9/9.sce @@ -0,0 +1,10 @@ +clc
+T1=1273; //K
+T2=313; //K
+n_max=1-T2/T1;
+Wnet=1;
+Q1=Wnet/n_max;
+Q2=Q1-Wnet;
+disp("the least rate of heat rejection = ")
+disp(Q2)
+disp("kW")
\ No newline at end of file |