Error
Posted: Sat Jun 03, 2017 2:58 pm
I am finding error in objective function, I will highly appreciate, If somebody tell me reason of error. Below is the detail of model..
sets
str process streams / 1*2/
comp compressor /1/
compon component feed /h2/
icomp(comp,str) inlet stream of compressor /1.1/
ocomp(comp,str) outlet stream of compressor /1.2/
com(comp,compon) compressor feed match /1.h2/ ;
scalars
alpha compressor efficiency /.3665/
compeff compressor efficiency /0.750/
gam ratio of cp to cv /1.300/
costelec electricity cost /0.340/ ;
positive variable
f(str) stream flow-rates (kg-mole per min)
fc(str,compon) component flow-rates (kg-mole per min)
p(str) stream pressure (mega_pascal)
t(str) stream temperature (100 k)
elec(comp) objective function
presrat(comp), z
;
equations
compcmb(comp,compon) component balance for compressor
comphb(comp) heat balance for compressor
compelec(comp) energy balance for compressor
ratio(comp) pressure ratio (out to in)
obj objective function ;
compcmb(comp,compon)..
sum( str $ ocomp(comp,str) , fc(str,compon) ) =e=
sum( str $ icomp(comp,str) , fc(str,compon) ) ;
comphb(comp)..
sum( str $ ocomp(comp,str) , t(str) ) =e=
presrat(comp) * sum( str $ icomp(comp,str) , t(str) ) ;
compelec(comp)..
elec(comp) =e=
alpha * ( presrat(comp) - 1) *
sum( str $ icomp(comp,str) , 100. * t(str) * f(str) / 60. ) *
(1 / compeff) * ( gam / ( gam - 1. ) ) ;
ratio(comp)..
presrat(comp) ** ( gam / ( gam - 1. ) ) =e=
sum( str $ ocomp(comp,str) , p(str) ) /
sum( str $ icomp(comp,str) , p(str) ) ;
obj.. z=e= sum(comp,(costelec)*elec(comp)) ;
model m /all/ ;
solve m using lp minimizing z;
sets
str process streams / 1*2/
comp compressor /1/
compon component feed /h2/
icomp(comp,str) inlet stream of compressor /1.1/
ocomp(comp,str) outlet stream of compressor /1.2/
com(comp,compon) compressor feed match /1.h2/ ;
scalars
alpha compressor efficiency /.3665/
compeff compressor efficiency /0.750/
gam ratio of cp to cv /1.300/
costelec electricity cost /0.340/ ;
positive variable
f(str) stream flow-rates (kg-mole per min)
fc(str,compon) component flow-rates (kg-mole per min)
p(str) stream pressure (mega_pascal)
t(str) stream temperature (100 k)
elec(comp) objective function
presrat(comp), z
;
equations
compcmb(comp,compon) component balance for compressor
comphb(comp) heat balance for compressor
compelec(comp) energy balance for compressor
ratio(comp) pressure ratio (out to in)
obj objective function ;
compcmb(comp,compon)..
sum( str $ ocomp(comp,str) , fc(str,compon) ) =e=
sum( str $ icomp(comp,str) , fc(str,compon) ) ;
comphb(comp)..
sum( str $ ocomp(comp,str) , t(str) ) =e=
presrat(comp) * sum( str $ icomp(comp,str) , t(str) ) ;
compelec(comp)..
elec(comp) =e=
alpha * ( presrat(comp) - 1) *
sum( str $ icomp(comp,str) , 100. * t(str) * f(str) / 60. ) *
(1 / compeff) * ( gam / ( gam - 1. ) ) ;
ratio(comp)..
presrat(comp) ** ( gam / ( gam - 1. ) ) =e=
sum( str $ ocomp(comp,str) , p(str) ) /
sum( str $ icomp(comp,str) , p(str) ) ;
obj.. z=e= sum(comp,(costelec)*elec(comp)) ;
model m /all/ ;
solve m using lp minimizing z;