import math # given data Gascook=5*0.227 # gas required for cooking in m^3/day Gaslight=0.126*2*3 # gas required for lighting in m^3/day Totalgasreq=Gascook+Gaslight # in m^3/day gasperday=0.34*0.18*7 # in m^3/day n=1+Totalgasreq/gasperday # no. of cows print "The number of cows is ",int(n) cowfeed=7*n # in kg slurry=cowfeed*2.0/1090 # in m^3 totalslurry=50.0*slurry # in m^3 reqvolume=totalslurry/0.9 print "The total volume of digester is ",round(reqvolume,2),"m^3"
The number of cows is 5 The total volume of digester is 3.86 m^3
import math # given data Gaslight=10*0.227*4 # gas required for lighting in m^3/day Eleccomp=10*250*6*60*60/1000000.0 # electrical energy required by computers in MJ effith=0.25 # thermal efficieny efficonv=0.80 # conversion efficiency Heat=23.0 # heating value of biogas in MJ/m^3 rho=1090.0 # slurry density in kg/m^3 Engineinput=Eleccomp/(effith*efficonv) energypump=746*2*2*60*60/1000000.0 # mechanical energy required for pumping in MJ themalinput=energypump/effith # required thermal input in MJ totalinput=themalinput+Engineinput # total thermal input required by engine Volreq=totalinput/Heat # volume required per day in m^3/day Totalrq=Volreq+Gaslight # total gas required in m^3 /day n=Totalrq/(7*0.18*0.34) # solid mass is 18% and n is number of cows required n=round(n) print "The number of cows is",n feed=7*n # daily feed in kg slurry=2*feed # in kg volslurry=slurry/rho # volume of slurry added per day in m^3 totalvol=50*volslurry/0.9 # total volume for 50 days in m^3 when 90 % is occupied by slurry print "The size of biogas plant is ",round(totalvol,2),"m^3"
The number of cows is 53.0 The size of biogas plant is 37.82 m^3
import math # given data Voldaily=1200 # daily production in m^3/day prodrate=Voldaily/24.0 # gas production rate per hour consrate=Voldaily/6.0 #gas consumtion rate per hour Vg1=(consrate-prodrate)*2 # gas holder size required for 2 hours in litres Vg2=prodrate*9 # gas holder size for 9 hours without consumption in litres if Vg1>Vg2: Vgmax=Vg1 else: Vgmax=Vg2 Vg=Vgmax*1.25 # required gas holder with 25 % safety margin in litres print "required gas holder size is ",Vg,"litres" Capacity=Vg/Voldaily # required gas holder capacity print "required gas holder capacity is ",round(Capacity*100,2),"%"
required gas holder size is 562.5 litres required gas holder capacity is 46.88 %
import math # given data drymattrprd=2 # dry matter produced in kg/day/cow gasyield=0.22 # biogas yield in m^3 /kg drymttr=18/100.0 # dry matter in cowdung rho=1090 # slurry density in kg/m^3 effibrnr=0.6 # burner efficiency Heat=23.0 # heating value of biogas in MJ/m^3 dungprd=drymattrprd*2/0.18 # dung produce in kg/day by 2 cows slurry=2*dungprd # slurry produce in kg/day volslurry=slurry/rho # volume of slurry in m^3 totalslurry=30*volslurry # for 30 days slurry in m^3 digestersize=totalslurry/0.85 # in m^3 print "the volume of digester is ",round(digestersize,2),"m^3" gasprd=drymattrprd*2*gasyield # gas produced in m^3/day Energytherm=gasprd*Heat*effibrnr # total thermal energy available in MJ/day thermalpower=Energytherm*1000000/(24*60*60) # in watts print "total thermal power is ",round(thermalpower,3),"W"
the volume of digester is 1.44 m^3 total thermal power is 140.556 W