summaryrefslogtreecommitdiff
path: root/Basic_Engineering_Thermodynamics_by_Rayner_Joel/Chapter18_1.ipynb
diff options
context:
space:
mode:
Diffstat (limited to 'Basic_Engineering_Thermodynamics_by_Rayner_Joel/Chapter18_1.ipynb')
-rw-r--r--Basic_Engineering_Thermodynamics_by_Rayner_Joel/Chapter18_1.ipynb205
1 files changed, 205 insertions, 0 deletions
diff --git a/Basic_Engineering_Thermodynamics_by_Rayner_Joel/Chapter18_1.ipynb b/Basic_Engineering_Thermodynamics_by_Rayner_Joel/Chapter18_1.ipynb
new file mode 100644
index 00000000..696c7fa6
--- /dev/null
+++ b/Basic_Engineering_Thermodynamics_by_Rayner_Joel/Chapter18_1.ipynb
@@ -0,0 +1,205 @@
+{
+ "cells": [
+ {
+ "cell_type": "markdown",
+ "metadata": {},
+ "source": [
+ "# Chapter 18 - Refrigeration"
+ ]
+ },
+ {
+ "cell_type": "markdown",
+ "metadata": {},
+ "source": [
+ "## Example 1: pg 612"
+ ]
+ },
+ {
+ "cell_type": "code",
+ "execution_count": 1,
+ "metadata": {
+ "collapsed": false
+ },
+ "outputs": [
+ {
+ "name": "stdout",
+ "output_type": "stream",
+ "text": [
+ "Example 18.1\n",
+ " (a) The coefficient of performance of the refrigerator is = 4.49\n",
+ " (b) The mass flow of refrigerant/h is (kg) = 166.94\n",
+ " (c) The mass flow of water required is (kg/h) = 579.74\n",
+ "The answer is a bit different due to rounding off error in textbook\n"
+ ]
+ }
+ ],
+ "source": [
+ "#pg 612\n",
+ "print('Example 18.1');\n",
+ "\n",
+ "# aim : To determine\n",
+ "# (a) the coefficient of performance\n",
+ "# (b) the mass flow of the refrigerant\n",
+ "# (c) the cooling water required by the condenser\n",
+ "import math\n",
+ "from math import log\n",
+ "# given values\n",
+ "P1 = 462.47;# pressure limit, [kN/m**2]\n",
+ "P3 = 1785.90;# pressure limit, [kN/m**2]\n",
+ "T2 = 273.+59;# entering saturation temperature, [K]\n",
+ "T5 = 273.+32;# exit temperature of condenser, [K]\n",
+ "d = 75*10**-3;# bore, [m]\n",
+ "L = d;# stroke, [m]\n",
+ "N = 8;# engine speed, [rev/s]\n",
+ "VE = .8;# olumetric efficiency\n",
+ "cpL = 1.32;# heat capacity of liquid, [kJ/kg K]\n",
+ "c = 4.187;# heat capacity of water, [kj/kg K]\n",
+ "\n",
+ "# solution\n",
+ "# from given table\n",
+ "# at P1\n",
+ "h1 = 231.4;# specific enthalpy, [kJ/kg]\n",
+ "s1 = .8614;# specific entropy,[ kJ/kg K\n",
+ "v1 = .04573;# specific volume, [m**3/kg]\n",
+ "\n",
+ "# at P3\n",
+ "h3 = 246.4;# specific enthalpy, [kJ/kg]\n",
+ "s3 = .8093;# specific entropy,[ kJ/kg K\n",
+ "v3 = .04573;# specific volume, [m**3/kg]\n",
+ "T3= 273+40;# saturation temperature, [K]\n",
+ "h4 = 99.27;# specific enthalpy, [kJ/kg]\n",
+ "# (a)\n",
+ "s2 = s1;# specific entropy, [kJ/kg k]\n",
+ "# using s2=s3+cpv*log(T2/T3)\n",
+ "cpv = (s2-s3)/log(T2/T3);# heat capacity, [kj/kg k]\n",
+ "\n",
+ "# from Fig.18.8\n",
+ "T4 = T3;\n",
+ "h2 = h3+cpv*(T2-T3);# specific enthalpy, [kJ/kg]\n",
+ "h5 = h4-cpL*(T4-T5);# specific enthalpy, [kJ/kg]\n",
+ "h6 = h5;\n",
+ "COP = (h1-h6)/(h2-h1);# coefficient of performance\n",
+ "print ' (a) The coefficient of performance of the refrigerator is = ',round(COP,2)\n",
+ "\n",
+ "# (b)\n",
+ "SV = math.pi/4*d**2*L;# swept volume of compressor/rev, [m**3]\n",
+ "ESV = SV*VE*N*3600;# effective swept volume/h, [m**3]\n",
+ "m = ESV/v1;# mass flow of refrigerant/h,[kg]\n",
+ "print ' (b) The mass flow of refrigerant/h is (kg) = ',round(m,2)\n",
+ "\n",
+ "# (c)\n",
+ "dT = 12;# temperature limit, [C]\n",
+ "Q = m*(h2-h5);# heat transfer in condenser/h, [kJ]\n",
+ "# using Q=m_dot*c*dT, so\n",
+ "m_dot = Q/(c*dT);# mass flow of water required, [kg/h]\n",
+ "print ' (c) The mass flow of water required is (kg/h) = ',round(m_dot,2)\n",
+ "\n",
+ "print 'The answer is a bit different due to rounding off error in textbook'\n",
+ "# End\n"
+ ]
+ },
+ {
+ "cell_type": "markdown",
+ "metadata": {},
+ "source": [
+ "## Example 2: pg 614"
+ ]
+ },
+ {
+ "cell_type": "code",
+ "execution_count": 2,
+ "metadata": {
+ "collapsed": false
+ },
+ "outputs": [
+ {
+ "name": "stdout",
+ "output_type": "stream",
+ "text": [
+ "Example 18.2\n",
+ " (a) The mass flow of R401 is (kg/h) = 592.6\n",
+ " (b) The dryness fraction of R401 at the entry to the evaporator is = 0.244\n",
+ " (c) The power to driving motor is (kW) = 5.86\n",
+ " (d) The ratio of heat transferred from condenser to the power required to the motor is = 4.74 :1\n"
+ ]
+ }
+ ],
+ "source": [
+ "#pg 614\n",
+ "print('Example 18.2');\n",
+ "\n",
+ "# aim : To determine\n",
+ "# (a) the mass flow of R401\n",
+ "# (b) the dryness fraction of R401 at the entry to the evaporator\n",
+ "# (c) the power of driving motor\n",
+ "# (d) the ratio of heat transferred from condenser to the power required to the motor\n",
+ "from math import log\n",
+ "# given values\n",
+ "P1 = 411.2;# pressure limit, [kN/m^2]\n",
+ "P3 = 1118.9;# pressure limit, [kN/m^2]\n",
+ "Q = 100*10**3;# heat transfer from the condenser,[kJ/h]\n",
+ "T2 = 273+60;# entering saturation temperature, [K]\n",
+ "\n",
+ "# given\n",
+ "# from given table\n",
+ "# at P1\n",
+ "h1 = 409.3;# specific enthalpy, [kJ/kg]\n",
+ "s1 = 1.7431;# specific entropy,[ kJ/kg K\n",
+ "\n",
+ "# at P3\n",
+ "h3 = 426.4;# specific enthalpy, [kJ/kg]\n",
+ "s3 = 1.7192;# specific entropy,[ kJ/kg K\n",
+ "T3 = 273.+50;# saturation temperature, [K]\n",
+ "h4 = 265.5;# specific enthalpy, [kJ/kg]\n",
+ "# (a)\n",
+ "s2 = s1;# specific entropy, [kJ/kg k]\n",
+ "# using s2=s3+cpv*log(T2/T3)\n",
+ "cpv = (s2-s3)/log(T2/T3);# heat capacity, [kj/kg k]\n",
+ "\n",
+ "# from Fig.18.8\n",
+ "h2 = h3+cpv*(T2-T3);# specific enthalpy, [kJ/kg]\n",
+ "Qc = h2-h4;# heat transfer from condenser, [kJ/kg]\n",
+ "mR401 = Q/Qc;# mass flow of R401, [kg]\n",
+ "print ' (a) The mass flow of R401 is (kg/h) = ',round(mR401,1)\n",
+ "\n",
+ "# (b)\n",
+ "hf1 = 219;# specific enthalpy, [kJ/kg]\n",
+ "h5 = h4;\n",
+ "# using h5=hf1+s5*(h1-hf1),so\n",
+ "x5 = (h5-hf1)/(h1-hf1);# dryness fraction\n",
+ "print ' (b) The dryness fraction of R401 at the entry to the evaporator is = ',round(x5,3)\n",
+ "\n",
+ "# (c)\n",
+ "P = mR401*(h2-h1)/3600/.7;# power to driving motor, [kW]\n",
+ "print ' (c) The power to driving motor is (kW) = ',round(P,2)\n",
+ "\n",
+ "# (d)\n",
+ "r = Q/3600./P;# ratio\n",
+ "print ' (d) The ratio of heat transferred from condenser to the power required to the motor is = ',round(r,2),\":1\"\n",
+ "\n",
+ "# End\n"
+ ]
+ }
+ ],
+ "metadata": {
+ "kernelspec": {
+ "display_name": "Python 2",
+ "language": "python",
+ "name": "python2"
+ },
+ "language_info": {
+ "codemirror_mode": {
+ "name": "ipython",
+ "version": 2
+ },
+ "file_extension": ".py",
+ "mimetype": "text/x-python",
+ "name": "python",
+ "nbconvert_exporter": "python",
+ "pygments_lexer": "ipython2",
+ "version": "2.7.11"
+ }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 0
+}
generated by cgit (git 2.34.1) at 2024-12-21 07:07:31 +0000