From 7f60ea012dd2524dae921a2a35adbf7ef21f2bb6 Mon Sep 17 00:00:00 2001 From: prashantsinalkar Date: Tue, 10 Oct 2017 12:27:19 +0530 Subject: initial commit / add all books --- 3831/CH14/EX14.14/Ex14_14.sce | 60 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 60 insertions(+) create mode 100644 3831/CH14/EX14.14/Ex14_14.sce (limited to '3831/CH14/EX14.14') diff --git a/3831/CH14/EX14.14/Ex14_14.sce b/3831/CH14/EX14.14/Ex14_14.sce new file mode 100644 index 000000000..d4a6a6371 --- /dev/null +++ b/3831/CH14/EX14.14/Ex14_14.sce @@ -0,0 +1,60 @@ +// Example 14_14 +clc;funcprot(0); +// Given data +m_ref=0.500;// kg/s +T_0=25.0;// °C +n_c=70.0;// The isentropic efficiency of compressor +// Using Figure 14.36 as the illustration for this example, the properties at the four stations can be found in Tables C.7e, C.7f, and C.8d as +// Station 1 +// Compressor inlet +x_1=1.00;// The quality of steam +T_1=-20.0;// °C +h_1=235.31;// kJ/kg +s_1=0.9332;// kJ/kg.K +p_1=132.99;// kPa +// Station 2 +// Compressor outlet +p_2s=800;// kPa +s_2=s_1;// kJ/kg.K +h_2s=271.10;// kJ/kg +T_2s=39.8;// °C +// Station 3 +// Condenser outlet +x_3=0.00;// The quality of steam +p_3=725;// kPa +h_3=87.46;// kJ/kg +s_3=0.3257;// kJ/kg.K +T_3=27.9;// °C +// Station 4h +// Expansion valve outlet +h_4h=h_3;// kJ/kg +p_4h=160;// kPa +h_4h=87.46;// kJ/kg +x_4h=0.280;// The quality of steam +s_4h=0.3449;// kJ/kg.K +T_4h=-15.6;// °C +T_e=-15.6;// °C + +// Calculation +// (a) +h_2=((h_2s-h_1)/(n_c/100))+h_1;// kJ/kg +p_2=p_2s;// kPa +//Interpolation in Table C.7f in Thermodynamic Tables to accompany Modern Engineering Thermodynamics (or through the use of an appropriate computer program) gives the following additional properties at this state: +s_2=0.9814;// kJ/kg.K +T_2=54.97;// °C +Q_condenser=m_ref*(h_3-h_2);// kJ/s +Q_evaporator=m_ref*(h_1-h_4h);// kJ/s +Q_compressor=m_ref*(h_2-h_1);// kJ/s +I_ac=m_ref*(T_0+273.15)*(s_2-s_1);// kW +I_con=(T_0+273.15)*((m_ref*(s_3-s_2))-(Q_condenser/(T_0+273.15)));// kW +I_ev=m_ref*(T_0+273.15)*(s_4h-s_3);// kW +I_e=(T_0+273.15)*((m_ref*(s_1-s_4h))-(Q_evaporator/(T_e+273.15)));// kW +I_total=I_ac+I_con+I_ev+I_e;// kW +W_compressor=Q_compressor;// kW +// (b) +COP=Q_evaporator/W_compressor;// The system coefficient of performance +T_L=T_e;// °C +COP_act=2.85;// The second law efficiency for a refrigeration system +E_RAC=(abs(1-((T_0+273.15)/(T_e+273.15)))*COP_act)*100;// % +printf("\n(a)The irreversibility rate of each component in the system are given below: \n I_adiabatic compressor=%1.2f kW \n I_condenser=%1.2f kW \n I_expansion valve=%1.2f kW \n I_evaporator=%1.2f kW \n The total irreversibility rate of the system,I_total=%2.0f kW \n(b)The system coefficient of performance,COP=%1.2f \n The second law efficiency for a refrigeration system,E_RAC=%2.1f percentage",I_ac,I_con,I_ev,I_e,I_total,COP,E_RAC); +// The answer provided in the text book is wrong(The value of h_2 changed little bit) -- cgit