{
 "metadata": {
  "name": "",
  "signature": "sha256:4d84c99a98fc36f8db8573496dfc2db7b4d7fab1f15bbd72f54e5f05cedbe4d8"
 },
 "nbformat": 3,
 "nbformat_minor": 0,
 "worksheets": [
  {
   "cells": [
    {
     "cell_type": "heading",
     "level": 1,
     "metadata": {},
     "source": [
      "Chapter3-Solar Energy Collectors"
     ]
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {},
     "source": [
      "Example 3.6.1-pg100"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "##Ex3.6.1.;calculate: solar altitude anglr,Incident angle,Collector efficiency\n",
      "import math\n",
      "##Solar declination :delta\n",
      "n=1\n",
      "delta=23.45*math.sin((360./365.)*(284.+n));\n",
      "print'%s %.2f %s'%(\" Solar declination delta=\",delta,\" degree\");\n",
      "fie=22.;##degree\n",
      "##solar hour angle ws=0,(at mean of 11:30 and 12:30)\n",
      "ws=0.;\n",
      "##Solar altitude anglr alpha is given by\n",
      "\n",
      "##alpha=asind(((cos(fie)*cos(delta)*cos(ws))+(sin(fie)*sin(delta)))\n",
      "##let\n",
      "a=math.cos((22*math.pi)/180.)*math.cos((-23*math.pi)/180.)*math.cos(0);\n",
      "b=math.sin((22*math.pi)/180.)*math.sin((-23*math.pi)/180.);\n",
      "##therefore\n",
      "sin_alpha=a+b;\n",
      "print'%s %.2f %s'%(\"\\n sin_aplha=\",sin_alpha,\"\");\n",
      "alpha=math.asin(sin_alpha);\n",
      "print'%s %.2f %s'%(\"\\n aplha=\",alpha,\"degree\");\n",
      "##Incident angle\n",
      "theta=(180./2.)-alpha;\n",
      "print'%s %.2f %s'%(\"\\n Incident angle=\",theta,\"degree\");\n",
      "##Rb is given by\n",
      "Rb=((math.cos(((22*math.pi)/180.)-(37*math.pi)/180.)*math.cos((-23*math.pi)/180.)*math.cos(0))+(math.sin(((22*math.pi)/180.)-(37*math.pi)/180)* math.sin((-23*math.pi)/180)))/sin_alpha;\n",
      "print'%s %.2f %s'%(\"\\n Rb=\",Rb,\"\");\n",
      "##Effective absorptance product is <t.alpha>=t.alpha/ 1-(1-alpha)*pd\n",
      "pd=0.24;##Diffuse reflectance for two glass covers\n",
      "##let TA=<t.alpha>\n",
      "TA=(0.88*0.90)/(1-(1-0.90)*pd);\n",
      "print'%s %.2f %s'%(\"\\n Effective absorptance product is <t.alpha>=\",TA,\"\");\n",
      "##Solar radiation intensity(consider beam radiation only)\n",
      "##Hb=0.5 ly/mm = 0.5 cal/cm^2 * min\n",
      "Hb=((0.5*10**4)/10**3)*60;##unit=kcal/m^2 hr\n",
      "print'%s %.2f %s'%(\"\\n Hb=\",Hb,\" kcal/m^2 hr\");\n",
      "Hb=Hb*1.163;##unit=W/m^2 hr;   [since  1 kcal = 1.163 watt]\n",
      "print'%s %.2f %s'%(\"\\n Hb=\",Hb,\" W/m^2 hr\");\n",
      "##S=Hb*Rb*<t.alpha>\n",
      "S=Hb*Rb*TA;\n",
      "print'%s %.2f %s'%(\"\\n S=\",S,\" W/m^2 hr\");\n",
      "s=S/1.163;\n",
      "print'%s %.2f %s'%(\"\\n S=\",s,\" kcal/m^2 hr\");\n",
      "##Useful gain\n",
      "##qu=FR(S-UL*(Tfi-Ta))\n",
      "qu=0.810*(s-(6.80*(60-15)))\n",
      "print'%s %.2f %s'%(\"\\n qu=\",qu,\" kcal/m^2 hr\");\n",
      "##Qu=FR(S-UL*(Tfi-Ta))\n",
      "Qu=0.810*(S-(7.88*(60-15)))\n",
      "print'%s %.2f %s'%(\"\\n qu=\",Qu,\" W/m^2 hr\");\n",
      "##Collection Efficiency  : nc=(qu/(Hb*Rb))*100;\n",
      "nc=(28.07/(300*Rb))*100.;\n",
      "print'%s %.2f %s'%(\"\\n Collection Efficiency=\",nc,\" persent\");\n",
      "\n",
      "\n",
      "##values of \"sine alpha\" in the textbook is taken approximate to the real values\n"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        " Solar declination delta= -23.38  degree\n",
        "\n",
        " sin_aplha= 0.71 \n",
        "\n",
        " aplha= 0.79 degree\n",
        "\n",
        " Incident angle= 89.21 degree\n",
        "\n",
        " Rb= 1.40 \n",
        "\n",
        " Effective absorptance product is <t.alpha>= 0.81 \n",
        "\n",
        " Hb= 300.00  kcal/m^2 hr\n",
        "\n",
        " Hb= 348.90  W/m^2 hr\n",
        "\n",
        " S= 396.50  W/m^2 hr\n",
        "\n",
        " S= 340.93  kcal/m^2 hr\n",
        "\n",
        " qu= 28.29  kcal/m^2 hr\n",
        "\n",
        " qu= 33.94  W/m^2 hr\n",
        "\n",
        " Collection Efficiency= 6.68  persent\n"
       ]
      }
     ],
     "prompt_number": 1
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {},
     "source": [
      "Example 3.9.1-pg 119"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "##calculate the useful gain,exit fluid temperature and collection efficiency\n",
      "##Optical properties are estimated as\n",
      "p=0.85;\n",
      "import math\n",
      "##(T. alpha)=0.77;let A=(T. alpha)\n",
      "A=0.77\n",
      "gama=0.94;\n",
      "Do=0.06;\n",
      "L=8;##unit=meter,##L=length of concentrator\n",
      "W=2;##W=width of concentrator in meter\n",
      "dco=0.09;##dco=diameter of transpaarent cover\n",
      "Ar= math.pi*Do*L;##Ar=area of the receiver pipe\n",
      "A_alpha=(W-dco)*L;##aperture area of the concentration\n",
      "Cp=0.30;##unit=kcal/kg degree calcius\n",
      "m=400;##unit=kg/hr,m=flow rate\n",
      "HbRb=600;##unit=kcal/hr m^2\n",
      "Tfi=150;##degree calcius\n",
      "T_alpha=25;##degree calcius\n",
      "##Heat transfer coefficient from fluid inside to surroundings,\n",
      "Uo=5.2;##unit=kcal/hr-m^2\n",
      "##Heat transfer coefficient from absorber cover surface to surroundings,\n",
      "UL=6;##unit=kcal/hr-m^2\n",
      "F=(Uo/UL);\n",
      "##Heat removed factor FR is\n",
      "##FR=((m*Cp)/(Ar*UL))*(1-(%e^-((Ar*UL*F)/(m*Cp))))\n",
      "##let X=(m*Cp)/(Ar*UL);Y=(%e^-((Ar*UL*F)/(m*Cp)))\n",
      "X=(m*Cp)/(1.51*UL*0.86);\n",
      "Y=math.e**(-1/X);\n",
      "FR=X*0.86*(1-Y);\n",
      "##Absorbed solar energy is\n",
      "S=HbRb*p*gama*A;\n",
      "print'%s %.2f %s %.2f %s'%(\" Area of the receiver pipe Ar= \",Ar,\"=1.51 m^2\"and\" \\n A_aplha= \",A_alpha,\" m^2=collection efficiency factor \");\n",
      "print'%s %.2f %s'%(\"\\n value of F= \",F,\"\");\n",
      "print'%s %.2f %s %.2f %s '%(\"\\n Heat removed factor FR=\",FR,\"\"and\" \\n Absorbed solar energy is \\n S=\",S,\" kcal/Hr m^2 .....(MKS) \");\n",
      "##for unit in S.I.   , 1 kcal/Hr m^2 = 1.16298 W/m^2\n",
      "s= S*1.16298; ##in W/m^2\n",
      "print'%s %.2f %s'%(\"\\n S=\",s,\" W/m^2.....(SI)\");\n",
      "##the values of F,FR will be same in any unit,since they are factors(dimensionless)\n",
      "##Useful Gain=Qu=A_alpha*FR*(S-((Ar*UL)/A_alpha)*(Tfi-T_alpha))\n",
      "##In MKS unit\n",
      "Qu=A_alpha*FR*(S-((1.51*UL)/A_alpha)*(Tfi-T_alpha))\n",
      "print'%s %.2f %s'%(\"\\n useful gain in (MKS) Qu=\",Qu,\" kcal/hr\");\n",
      "##IN SI unit\n",
      "qu=A_alpha*FR*(s-((1.51*6.98)/A_alpha)*(Tfi-T_alpha))##UL=6.98 W/m^2 degree celcius\n",
      "print'%s %.2f %s'%(\"\\n useful gain in (SI) Qu=\",qu,\" Watt\");\n",
      "##the exit fluid temperature can be obtained from\n",
      "tci=150;##degree celcius\n",
      "tco=tci+(Qu/(m*Cp));##from Qu=mCp(tco-tc);  where, tco=collector fluid temp. at outlet,tci=Fluid inlet temp.\n",
      "n=(Qu/(16*HbRb))*100;##ncollector=Qu/(A_alpha*HbRb)*100;\n",
      "print'%s %.2f %s %.2f %s'%(\"\\n collector fluid temp. at outlet  tco=\",tco,\" degree celcius\"and \" \\n ncollector = \",n,\" percent \");\n",
      "\n",
      "##The values/results/answers is approximate in the text book to the real calculated value\n"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        " Area of the receiver pipe Ar=  1.51  \n",
        " A_aplha=  15.28  m^2=collection efficiency factor \n",
        "\n",
        " value of F=  0.87 \n",
        "\n",
        " Heat removed factor FR= 0.83  369.14  kcal/Hr m^2 .....(MKS)  \n",
        "\n",
        " S= 429.30  W/m^2.....(SI)\n",
        "\n",
        " useful gain in (MKS) Qu= 3753.64  kcal/hr\n",
        "\n",
        " useful gain in (SI) Qu= 4365.07  Watt\n",
        "\n",
        " collector fluid temp. at outlet  tco= 181.28  \n",
        " ncollector =  39.10  percent \n"
       ]
      }
     ],
     "prompt_number": 2
    }
   ],
   "metadata": {}
  }
 ]
}