{ "cells": [ { "cell_type": "markdown", "metadata": {}, "source": [ "# Chapter 10 : Steam Power Plant and Rankine Cycle" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "## Example 10.1 Page No : 244" ] }, { "cell_type": "code", "execution_count": 1, "metadata": { "collapsed": false }, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "Carnot efficiency of an engine when the steam is 0.87 dry in % is : 21.75\n", "Carnot efficiency of an engine when the steam is dry saturated in % is : 21.75\n", "Carnot efficiency of an engine when the steam is superheated in % is : 29.53\n" ] } ], "source": [ "\n", "# Variables\n", "p1 = 10;\t\t\t# in bar\n", "p2 = 0.5;\t\t\t# in bar\n", "T1 = 179.9;\t\t\t# in °C\n", "T1 = T1 +273;\t\t\t# in K\n", "T2 = 81.4;\t\t\t# in °C\n", "\n", "# Calculations and Results\n", "T2 = T2 + 273;\t\t\t# in K\n", "Eta_carnot = (T1 - T2)/T1*100;\t\t\t# in %\n", "print \"Carnot efficiency of an engine when the steam is 0.87 dry in %% is : %.2f\"%Eta_carnot\n", "print \"Carnot efficiency of an engine when the steam is dry saturated in %% is : %.2f\"%Eta_carnot\n", "\n", "T1 = T1 + 50;\t\t\t# in K\n", "Eta_carnot1 = (T1 - T2) / T1*100;\t\t\t# in %\n", "print \"Carnot efficiency of an engine when the steam is superheated in %% is : %.2f\"%Eta_carnot1\n" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "## Example 10.2 Page No : 247" ] }, { "cell_type": "code", "execution_count": 4, "metadata": { "collapsed": false }, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "Heat supplied to the boiler in kJ/kg is 2900.05\n", "Work developed by turbine in kJ/kg is : 689.0\n", "Work absorbed by pump in kJ/kg is : 1.95\n", "Efficiency of flow system in % is : 23.69\n" ] } ], "source": [ "\n", "# Variables\n", "h1 = 3015.;\t \t\t# in kJ/kg\n", "h2 = 2326.;\t \t\t# in kJ/kg\n", "h3 = 113;\t\t \t# in kJ/kg\n", "h4 = 114.95;\t\t\t# in kJ/kg\n", "\n", "# Calculations and Results\n", "Q = h1 - h4;\t\t\t# in kJ/kg\n", "print \"Heat supplied to the boiler in kJ/kg is\",Q\n", "\n", "W_T = h1 - h2;\t\t\t#/ in kJ/kg\n", "print \"Work developed by turbine in kJ/kg is : %.1f\"%W_T\n", "\n", "W_P = ( h1 - h3) - Q;\t\t\t# in kJ/kg\n", "print \"Work absorbed by pump in kJ/kg is : \",W_P\n", "\n", "Eta = (W_T - W_P)/Q*100;\t\t\t# in %\n", "print \"Efficiency of flow system in %% is : %.2f\"%Eta\n" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "## Example 10.3 Page No : 248" ] }, { "cell_type": "code", "execution_count": 2, "metadata": { "collapsed": false }, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "Rankine efficiency in % is : 20.09\n", "Percentage drop in Rankine efficiency in % is : 1.01\n", "Percentage increase in rankine efficiency in % is : 1.51\n" ] } ], "source": [ "import math\n", "\n", "# Variables\n", "phi_s = 6.583;\n", "phi_w = 1.091;\n", "phi_s1 = 6.504;\n", "C_p = 2.25;\n", "T_sat =179.9; \t\t\t# in °C\n", "T_sat = T_sat + 273;\t\t\t# in K\n", "T_sup = T_sat + 50;\t\t\t# in K\n", "x2 = (phi_s - phi_w)/phi_s1;\n", "H1 = 2776.2; \t\t\t# in kJ/kg\n", "H_w2 = 340.6;\t\t\t# in kJ/kg\n", "L2 = 2305.;\n", "\n", "# Calculations and Results\n", "H2 = H_w2 + (x2 * L2);\t\t\t# in kJ/kg\n", "Eta_rankine = (H1 - H2)/(H1 - H_w2)*100;\t\t\t# in %\n", "print \"Rankine efficiency in %% is : %.2f\"%Eta_rankine\n", "\n", "phi_w1 = 2.138;\n", "x1 = 0.87;\n", "phi_s1 = 4.445;\n", "phi_w2 = 1.091;\n", "phi_s2 = 6.504;\n", "x2 = (phi_w1 + (x1 * phi_s1) - phi_w2) / phi_s2;\n", "H1 = 762.6 + (x1 * 2013.6);\t\t\t# in kJ/kg\n", "H2 = 340.6 + (x2 * 2305);\t\t\t# in kJ/kg\n", "Eta_rankine1 = (H1 - H2) / (H1 - H_w2)*100;\t\t\t# in %\n", "PerDropInRankine= (Eta_rankine - Eta_rankine1)/Eta_rankine * 100;\t\t\t# in %\n", "print \"Percentage drop in Rankine efficiency in %% is : %.2f\"%PerDropInRankine\n", "\n", "phi_s1 = 6.583;\n", "phi_w1 = 1.091;\n", "phi_s2 = 6.504;\n", "x2 = (phi_s1 + C_p * math.log(T_sup/T_sat) - phi_w1)/phi_s2;\n", "H_s1 = 2776.2;\n", "H1 = H_s1 + C_p * (T_sup - T_sat);\t\t\t# in kJ/kg\n", "H2 = 340.6 + (0.88 * 2305);\t\t\t# in kJ/kg\n", "H_w2 = 340.6;\n", "Eta_rankine2 = (H1 - H2) / (H1 - H_w2);\n", "Eta_rankine2 = Eta_rankine2 * 10**2;\t\t\t# in percentage\n", "PerIncInRank = ((Eta_rankine2 - Eta_rankine)/Eta_rankine2) * 100;\t\t\t# in percentage\n", "print \"Percentage increase in rankine efficiency in %% is : %.2f\"%PerIncInRank\n", "\n", "# rounding off error" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "## Example 10.4 Page No : 253" ] }, { "cell_type": "code", "execution_count": 1, "metadata": { "collapsed": false }, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "Thermal effienciency of the cycle in % is : 15.70\n", "Heat removed in condenser in kJ/kg is : 2101.9\n" ] } ], "source": [ "\n", "# Variables\n", "H2 = 2776.2;\t\t\t# in kJ/kg\n", "p1 = 10.;\t\t\t# in bar\n", "p_2 = 1.;\t\t\t# in bar\n", "p_3 = 0.25;\t\t\t# in bar\n", "p_4 = p_3;\t\t\t# in bar\n", "# w = (H2 - H_2) + ((p_2 - p_3) * v_2);\t\t\t# work done in kJ/kg\n", "phi_2 = 6.583;\n", "phi_d2 = 1.303;\n", "L = 6.057;\n", "x_2 = (phi_2 - phi_d2) / L;\n", "H2_desh = 417.5 + (x_2* 2257.9);\t\t\t# in kJ/kg\n", "v_s = 1.694;\n", "\n", "# Calculations and Results\n", "v_2 = x_2 * v_s;\t\t\t# in m**3 per kg\n", "w = (H2 - H2_desh) + ((p_2 - p_3) * v_2);\t\t\t# in kJ/kg\n", "H4 = 282.7;\t\t\t# in kJ/kg\n", "H_w4 =H4;\t\t\t# in kJ/kg\n", "HeatSupplied = H2 - H4;\t\t\t# kJ/kg\n", "Eta_modifiedRankine = w / HeatSupplied*100;\t\t\t# in %\n", "print \"Thermal effienciency of the cycle in %% is : %.2f\"%Eta_modifiedRankine\n", "\n", "HeatRemoved = HeatSupplied - w;\t\t\t# in kJ/kg\n", "print \"Heat removed in condenser in kJ/kg is : %.1f\"%HeatRemoved\n", "\n", "# rounding off error" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "## Example 10.13 Page No : 256" ] }, { "cell_type": "code", "execution_count": 7, "metadata": { "collapsed": false }, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "Work output per kg in kW is : 1110.0\n", "flow rate in kg/hr is : 3567.57\n" ] } ], "source": [ "\n", "# Variables\n", "Q = 1100;\t\t\t# in kW\n", "m = 1; \t\t\t# in kg\n", "p1 = 15;\t\t\t# in bar\n", "p1 = p1 * 10**5;\t\t\t# in Pa\n", "p1 = p1 * 10**-3;\t\t\t# in kPa\n", "p2 = 0.05 * 10**2;\t\t\t# in kPa\n", "v1 = 0.16;\t\t\t# m**3 per kg\n", "v2 = 26;\t\t\t# in m**3 per kg\n", "V1 = 110;\t\t\t# in m per s\n", "V2 = 120;\t\t\t# in m per s\n", "u1 = 2935;\t\t\t# in kJ per kg\n", "u2 = 1885;\t\t\t# in kJ per kg\n", "g = 9.8;\n", "z1 = 0;\n", "z2 = 0; \n", "\n", "# Calculations and Results\n", "# Formula Q-W= m*{(u2 - u1) + (p2*v2-p1*v1)+1/2*(V2**2-V1**2)+g*(z2 - z1)}\n", "W =Q-m*((u2 - u1) + (p2*v2-p1*v1)+1./2*(V2**2-V1**2)+g*(z2 - z1));\t\t\t# in kW\n", "print \"Work output per kg in kW is : \",W\n", "\n", "SteamFlowRate = Q / W;\t\t\t# in kg/sec\n", "SteamFlowRate = SteamFlowRate * 3600;\t\t\t# in kg per hr\n", "print \"flow rate in kg/hr is : %.2f\"%SteamFlowRate\n" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "## Example 10.14 Page No : 257" ] }, { "cell_type": "code", "execution_count": 2, "metadata": { "collapsed": false }, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "The Ratio of mass flow rate of cooling water to condensing steam is : 36.24\n" ] } ], "source": [ "\n", "# Variables\n", "h_sen = 191.9;\t\t\t# in kJ/kg\n", "L = 2392;\t\t\t# in kJ/kg\n", "x = 0.95;\n", "t_o = 35;\t\t\t# in °C\n", "t_i = 20;\t\t\t# in °C\n", "C = 4.18;\n", "\n", "# Calculations\n", "H_totalwet = h_sen + (x * L);\t\t\t#in kJ/kg\n", "# m_steam * (H_totalwet - h_sen) = m_water * C * (t_o - t_i)\n", "msBYmw = (H_totalwet - h_sen) / ( C * (t_o - t_i));\t\t\t#\n", "\n", "# Results\n", "print \"The Ratio of mass flow rate of cooling water to condensing steam is : %.2f\"%msBYmw\n", "\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": "2.7.6" } }, "nbformat": 4, "nbformat_minor": 0 }