{ "cells": [ { "cell_type": "markdown", "metadata": {}, "source": [ "# Chapter 10: Hydraulic Turbines" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "## Example 10.1: HT.sce" ] }, { "cell_type": "code", "execution_count": null, "metadata": { "collapsed": true }, "outputs": [], "source": [ "clear all; clc;\n", "//the values of omegas and energycoeeficient differ from the ones given in the book\n", "//the reasons for the same are mentioned in the code below\n", "H=85\n", "Q=16\n", "E=0.9//efficiency\n", "g=9.8\n", "rho=998\n", "\n", "P_o=E*rho*Q*g*H/1000\n", "printf('The estimated power (Po) is equal to %0.0f kW',P_o)\n", "\n", "\n", "disp('From figure 10.11,a Francis Turbine is selected. Then with the synchronous speed of 16 poles N is determined')\n", "N=120*60/16\n", "printf('N is equal to %grpm',N)\n", "\n", "\n", "N_s=(N*Q^0.5)/H^0.75\n", "printf('\nWe have value of Ns equal to %0.1f rpm(m^3/s)^0.5',N_s)\n", "\n", "\n", "Ksigma=2.11\n", "n=450/60\n", "g=9.8\n", "sigma=(Ksigma*n*Q^0.5)/((g*H)^0.75)\n", "printf('\n Value of sigma is equal to %0.2f',sigma)\n", "\n", "\n", "omega=(%pi*N)/30\n", "V=16\n", "omega_s=(omega*V^0.5)/((g*H)^0.75)//Answer given in the book is 1.33,this is because H has been wrongly substitued as 75. The correct substitution(H=85),gives the answer equal to 1.2157.\n", "thita=1.9\n", "K=1.054\n", "printf('\n Value of omegas is equal to %g',omega_s)\n", "\n", "\n", "disp('From figure 10.10 we have thita=1.9 for nq=Ns=64.3')\n", "disp('Since K*D*(g*H)^0.25/Q^0.5=thita, we can determine D.')\n", "\n", "D=(thita*(Q^0.5))/(((g*H)^0.25)*K)\n", "printf('\n Value of D is equal to %0.2f m ',D)\n", "\n", "\n", "disp('From figure 10.9 we have efficiency=0.95,which is close to the original estimation')\n", "D=1.34//value of D is approximately equal to 1.34\n", "k_phi=(%pi^2)/4\n", "k_psi=(%pi^2)/2\n", "flowcoeff=Q/(k_phi*n*(D^3))\n", "printf('The flow coefficient is equal to %0.3f',flowcoeff)\n", "\n", "\n", "energycoeff=(g*H)/(k_psi*(n^2)*(D^2))\n", "printf('\nThe energy coefficient is equal to %0.4f',energycoeff)//Answer given in the book is 1.47,this is because H has been wrongly substitued as 75. The correct substitution(H=85),gives the answer equal to 1.6713.\n", "" ] } , { "cell_type": "markdown", "metadata": {}, "source": [ "## Example 10.2: HT.sce" ] }, { "cell_type": "code", "execution_count": null, "metadata": { "collapsed": true }, "outputs": [], "source": [ "clear all; clc;\n", "\n", "disp('From psi=(g*H)/(omega^2*D^2) and N=30*omega/pi we get N=172.7/(psi^0.5)')\n", "disp('Also from phi=Q/(omega*D^3) and pi=Ps/(rho*omega^3*D^5) we get Q=0.353*phi*N and Ps=0.0087*N^3*pi')\n", "disp('Pick the points along 80% gate opening curve,read the values for phi,psi, and efficiency from figure 10.14')\n", "\n", "phi=[0.158 0.151 0.14 0.127 0.108 0.092 0.076 0.066];\n", "psi= [0.093 0.083 0.071 0.06 0.048 0.04 0.03 0.025];\n", "E= [55 56.5 58 62.5 69 71.5 67.5 60];//efficiency\n", "pai= [0.0078 0.0067 0.0058 0.0045 0.0034 0.0025 0.0015 0.001];\n", "\n", "N = zeros(1,length(phi));\n", "Ps = zeros(1,length(phi));\n", "Q = zeros(1,length(phi));\n", "\n", "for i = 1: length(phi)\n", " \n", "\n", " N(i) = 172.7/sqrt(psi(i));\n", " Ps(i) = 0.0087*N(i)^3*pai(i)*10^-3;\n", " Q(i) = 0.353*phi(i)*N(i);\n", "end\n", "\n", "disp(' phi psi eff(%) pai N(rpm) Ps(mw) Q(m^3/s)')\n", "\n", "table = [phi' psi' E' pai' N' Ps' Q'];\n", "disp(table)\n", "\n", "plot(N,Ps,'o',N,Q,'d',N,E,'s')\n", "legend('Ps (mw)','Q (m^3/s)','Eff (%)',-1)\n", "xlabel('N (rpm)')\n", "ylabel('Ps (mW), Q (m^3/s) , eff (%)')\n", "set(gca(),'grid',[1 1])\n", "\n", "" ] } , { "cell_type": "markdown", "metadata": {}, "source": [ "## Example 10.3: HT.sce" ] }, { "cell_type": "code", "execution_count": null, "metadata": { "collapsed": true }, "outputs": [], "source": [ "clear all; clc;\n", "D=3\n", "dn=0.08\n", "H=350\n", "En=0.82\n", "CVb=0.95\n", "Em=0.90\n", "Ev=0.96\n", "g=9.8\n", "\n", "V2=(2*En*g*H)^0.5\n", "printf(' The jet flow velocity is equal to %0.0f m/s',V2)\n", "\n", "Um=0.5*V2\n", "printf('\n Optimum wheel tangential velocity is Um is equal to %0.1f m/s',Um)\n", "\n", "N=(60*Um)/(%pi*D)\n", "printf('\n The rotating speed N is equal to %0.1f rpm',N)\n", "\n", "disp('Under the maximum utilization factor condition,we have beta3=90 degrees')\n", "disp(' Since delta Emax=(1+CVb)*U(V2-U),we get the equation delta Emax=1.95*(U^2)')\n", "delta_E_max=(1+CVb)*Um*(V2-Um)\n", "printf(' The value of deltaEmax is equal to %g N-m/kg',delta_E_max)\n", "\n", "An=(%pi/4)*(dn^2)\n", "Q=V2*An\n", "printf('\n The flow rate is %0.3f m^3/s',Q)\n", "\n", "m=998*Q\n", "Ps=Em*Ev*m*delta_E_max/1000\n", "printf('\n The total shaft power output is %0.1f kW',Ps)\n", "\n", "Ns=(N*(Q^0.5))/(H^0.75)\n", "printf('\n The specific speed can be calculated as %0.2f rpm((m^3/s)^0.5)/(m^0.75)',Ns)\n", "\n", "omega=%pi*N/30\n", "omega_s=omega*(Q^0.5)/((g*H)^0.75)\n", "printf('\n In non dimensional form , omegas is equal to %0.3f',omega_s)\n", "\n", "\n", "\n", "\n", "\n", "\n", "\n", "\n", "\n", "\n", "\n", "\n", "\n", "\n", "" ] } , { "cell_type": "markdown", "metadata": {}, "source": [ "## Example 10.4: HT.sce" ] }, { "cell_type": "code", "execution_count": null, "metadata": { "collapsed": true }, "outputs": [], "source": [ "clear all; clc;\n", "H=80\n", "Q=63\n", "Es=0.97\n", "N=400\n", "V3=25\n", "Dh3=2\n", "rh3=1/12\n", "g=32.2\n", "\n", "Ksigma=2.11\n", "n=N/60\n", "sigma=(Ksigma*n*(Q^0.5))/((g*H)^0.75)\n", "printf(' The value of sigma is equal to %0.2f ', sigma)\n", "\n", "disp('We have thita=2.4. Thita is also equal to Kt*D2*((g*H)^0.25)/(Q^0.5)')\n", "thita=2.4\n", "Kt=1.054\n", "D2=(thita*(Q^0.5))/(Kt*((g*H)^0.25))\n", "printf(' Thus the value of D2 is %0.1f ft',D2)\n", "\n", "D2r=2.5//rounded off D2\n", "U2=(D2r*N*%pi)/60\n", "printf('\n U2 is equal to %0.2f ft/s',U2)\n", "\n", "V2=(2*g*H*Es)^0.5\n", "printf('\n The inlet flow velocity V2 is equal to %0.2f ft/s',V2)\n", "\n", "disp('From the inlet velocity diagram for alpha2=20 degrees we have Vr2=V2*sinalpha2')\n", "alpha2=20\n", "Vr2=V2*(sin(alpha2*%pi/180))\n", "printf(' Vr2 is equal to %0.2f ft/s',Vr2)\n", "\n", "tanbeta2=Vr2/(V2*(cos(alpha2*%pi/180))-U2)\n", "printf('\n The value of tanbeta2 is %0.2f',tanbeta2)\n", "beta2=(atan(tanbeta2))*180/%pi\n", "printf('\n Thus value of beta2 is %0.1f degrees',beta2)\n", "\n", "disp('Selecting the incidence i=2.2 degrees we have betab2=62 degrees')\n", "\n", "disp('A2=Q/Vr2=(%pi*D2*b2) From this equation we can determine the value of b2.')\n", "A2=Q/Vr2\n", "printf(' A2 is equal to %0.2f ft^2',A2)\n", "b2=A2/(%pi*D2)\n", "printf('\n b2 is equal to %0.2f ft',b2)\n", "disp('Thus b2= 4 inches')\n", "\n", "disp('At the outlet with rh3=1 inch, setting gamma=15 degrees and V3=25')\n", "gamma1=15\n", " A3=Q/V3\n", "printf(' The value of A3 is equal to %g ft^2',A3)\n", " rt3=((A3*(cos(gamma1*%pi/180)))/%pi+(rh3^2))^0.5\n", " printf('\n The value of rt3 is %0.2f ft',rt3)\n", " disp('On converting the value of rt3 from feet to inches we get rt3=10.6inches')\n", " \n", " rt3c=10.6//converted value of rt3\n", " rh3c=1//converted value in inches\n", " rm3=((((rt3c^2+ rh3c^2)/2)^0.5)/12)\n", " printf(' The mean radius rm3 is equal to %0.3f ft',rm3)\n", " Um3=26.3 \n", " tanbetam3=V3/Um3\n", " printf('\n The value of tanbetam3 %0.2f',tanbetam3)\n", " betam3=atan(tanbetam3)*180/%pi\n", " printf('\n The value of betam3 whih is equal to betabm3 if no deviation is assumed is equal to %0.2f degrees',betam3)\n", " disp('On rounding off we get the value og betam3=43.6 degrees')\n", "\n", "\n", "\n", "\n", "\n", "\n", "\n", "\n", "\n", "\n", "\n", "\n", "\n", "\n", "\n", "\n", "" ] } , { "cell_type": "markdown", "metadata": {}, "source": [ "## Example 10.5: HT.sce" ] }, { "cell_type": "code", "execution_count": null, "metadata": { "collapsed": true }, "outputs": [], "source": [ "clear all; clc;\n", "disp('To use figure 10.21 we need the dimensional power specific speed. So the shaft power has to be estimated from figure 10.9 where the non dimensional omegas is needed.')\n", "\n", "Ve=5\n", "Hl=0.7\n", "\n", "H=80\n", "Q=63\n", "Es=0.97\n", "N=400\n", "V3=25\n", "Dh3=2\n", "rh3=1/12\n", "g=32.2\n", "\n", "omega=N*%pi/30\n", "omega_s=omega*(Q^0.5)/((g*H)^0.75)\n", "printf(' The value of omegas is %0.2f',omega_s)\n", "\n", "disp('We have efficiency=0.95')\n", "E=0.95\n", "rho=1.9378\n", "Ps=E*rho*g*Q*H/550//conversion factor =1/550\n", "printf(' The value of Ps %0.2f hp',Ps)\n", "\n", "Nsp=N*(Ps^0.5)/(80^1.25)\n", "printf('\nThe value of Nsp is equal to %0.2f rpm(hp^0.5)/ft^1.25',Nsp)\n", "\n", "disp('From figure 10.21, we obtain sigma approximately equal to 0.1 or NSPHavail/H is greater than or equal to 0.1')\n", "disp('NSPHavail =Ha-Z+Hl+Ve^2/(2*g)) and NSPH avail is greater than or equal to 8 ft.')\n", "disp('At T=70 degrees farenheit we have the value of Ha equal to')\n", "Ha=14.7*144/62.4\n", "printf(' %0.2f ft.',Ha)\n", "Hv=0.363*144/62.4\n", "printf('\n The value of Hv is equal to %0.2f ft',Hv)\n", "K=(Ve^2)/(2*g)\n", "NPSHavail=8\n", "printf('\n The value of (Ve^2)/(2*g) is equal to %0.2f ft',K)\n", "//In the book the value of Zmax is directly stated\n", "//I have used the given formualae and substiuted the values in it\n", "//let NPSHavail=8\n", "//then from the given formula we can find out the value of Zmax\n", "\n", "NPSH_avail=8\n", "H_vr=0.84//rounded off value\n", "Kr=0.39//rounded off value\n", "H_ar=33.9//rounded off value\n", "Z =H_ar-NPSH_avail+Hl+Kr-H_vr//Kr= rounded off value of (Ve^2)/(2*g)\n", "printf('\n The value of Zmax is equal to %0.1f ft',Z)\n", "\n", "\n", "\n", "\n", "\n", "\n", "\n", "\n", "\n", "\n", "\n", "\n", "\n", "\n", "\n", "\n", "\n", "\n", "\n", "\n", "\n", "\n", "" ] } ], "metadata": { "kernelspec": { "display_name": "Scilab", "language": "scilab", "name": "scilab" }, "language_info": { "file_extension": ".sce", "help_links": [ { "text": "MetaKernel Magics", "url": "https://github.com/calysto/metakernel/blob/master/metakernel/magics/README.md" } ], "mimetype": "text/x-octave", "name": "scilab", "version": "0.7.1" } }, "nbformat": 4, "nbformat_minor": 0 }