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Economic Pipe Diameter Sizer
Core Numerical Engine in Fortran 90 • 33 total downloads
economic_pipe.f90
! =========================================================================
! Source File: economic_pipe.f90
! =========================================================================
program economic_pipe
implicit none
integer::iostat_val,i,ns,best_i
double precision::Q,rho,mu,cp_fac,ec,hrs,eta,f_in,L,rate,life
double precision::pi_v,D,V,Re,f_sw,dP,Pw,E_cost,C_cost,T_cost
double precision::CRF,D_opt,V_opt,Re_opt,T_min,E_opt,C_opt
double precision::D_mm,f_auto
pi_v=3.14159265358979d0
read(*,*,iostat=iostat_val) Q;read(*,*,iostat=iostat_val) rho
read(*,*,iostat=iostat_val) mu;read(*,*,iostat=iostat_val) cp_fac
read(*,*,iostat=iostat_val) ec;read(*,*,iostat=iostat_val) hrs
read(*,*,iostat=iostat_val) eta;read(*,*,iostat=iostat_val) f_in
read(*,*,iostat=iostat_val) L;read(*,*,iostat=iostat_val) rate
read(*,*,iostat=iostat_val) life
if(iostat_val/=0)then;write(*,*)'ERROR: Bad input.';stop;end if
if(Q<=0)Q=0.01d0;if(rho<=0)rho=998.0d0;if(mu<=0)mu=0.001d0
if(cp_fac<=0)cp_fac=5.0d0;if(ec<=0)ec=0.10d0;if(hrs<=0)hrs=8760.0d0
if(eta<=0.or.eta>1)eta=0.70d0;if(L<=0)L=100.0d0
if(rate<=0)rate=5.0d0;if(life<=0)life=20.0d0
CRF=(rate/100.0d0)*(1.0d0+rate/100.0d0)**life/((1.0d0+rate/100.0d0)**life-1.0d0)
write(*,'(A)')'============================================================'
write(*,'(A)')' ECONOMIC PIPE DIAMETER OPTIMIZER'
write(*,'(A)')'============================================================'
write(*,*)
write(*,'(A)')'--- INPUTS --------------------------------------------------'
write(*,'(A,ES10.3,A)') ' Volume Flow Q = ',Q,' m3/s'
write(*,'(A,F10.2,A)') ' Fluid Density rho = ',rho,' kg/m3'
write(*,'(A,ES10.3,A)') ' Viscosity mu = ',mu,' Pa.s'
write(*,'(A,F10.2,A)') ' Pipe Cost Factor = ',cp_fac,' $/m per mm'
write(*,'(A,F10.4,A)') ' Energy Cost = ',ec,' $/kWh'
write(*,'(A,F10.0,A)') ' Operating Hours = ',hrs,' h/yr'
write(*,'(A,F10.2)') ' Pump Efficiency = ',eta
write(*,'(A,F10.2,A)') ' Pipe Length = ',L,' m'
write(*,'(A,F10.2,A)') ' Interest Rate = ',rate,' percent'
write(*,'(A,F10.0,A)') ' Lifetime = ',life,' years'
write(*,'(A,F10.6)') ' Capital Recovery Factor = ',CRF
write(*,*)
T_min=1.0d30;best_i=0;D_opt=0;V_opt=0;Re_opt=0;E_opt=0;C_opt=0
ns=50
write(*,'(A)')'--- COST VS DIAMETER ----------------------------------------'
write(*,'(A)')' D[mm] V[m/s] Re f E_cost[$/yr] C_cost[$/yr] Total[$/yr]'
write(*,'(A)')' --------------------------------------------------------------------------'
do i=1,ns
D_mm=15.0d0+dble(i-1)*(500.0d0-15.0d0)/dble(ns-1)
D=D_mm/1000.0d0
V=4.0d0*Q/(pi_v*D**2)
Re=rho*V*D/mu
if(f_in>0)then;f_sw=f_in
else
if(Re>0)then;f_auto=0.25d0/(log10(5.74d0/Re**0.9d0))**2
if(f_auto<0.005d0)f_auto=0.005d0;if(f_auto>0.1d0)f_auto=0.1d0
f_sw=f_auto
else;f_sw=0.02d0;end if
end if
dP=f_sw*L/D*rho*V**2/2.0d0
Pw=Q*dP/eta
E_cost=Pw*hrs*ec/1000.0d0
C_cost=cp_fac*D_mm*L*CRF
T_cost=E_cost+C_cost
if(T_cost<T_min)then;T_min=T_cost;best_i=i;D_opt=D_mm;V_opt=V;Re_opt=Re
E_opt=E_cost;C_opt=C_cost;end if
write(*,'(F7.1,2X,F6.2,2X,ES10.3,2X,F7.5,2X,F10.2,4X,F10.2,4X,F10.2)') &
D_mm,V,Re,f_sw,E_cost,C_cost,T_cost
end do
write(*,*)
write(*,'(A)')'--- OPTIMAL RESULT ------------------------------------------'
write(*,'(A,F10.1,A)') ' Optimal Diameter D_opt = ',D_opt,' mm'
write(*,'(A,F10.3,A)') ' Optimal Velocity V_opt = ',V_opt,' m/s'
write(*,'(A,ES12.3)') ' Reynolds at D_opt = ',Re_opt
write(*,'(A,F10.2,A)') ' Annual Energy Cost = ',E_opt,' $/yr'
write(*,'(A,F10.2,A)') ' Annual Capital Cost = ',C_opt,' $/yr'
write(*,'(A,F10.2,A)') ' Min Total Annual Cost = ',T_min,' $/yr'
write(*,*)
write(*,'(A)')'--- CORRELATIONS USED ---------------------------------------'
write(*,'(A)')' Swamee-Jain: f = 0.25/[log10(5.74/Re^0.9)]^2'
write(*,'(A)')' E_cost = (Q*dP/eta)*hours*price/1000'
write(*,'(A)')' C_cost = cost_per_mm*D*L*CRF'
write(*,'(A)')' CRF = i(1+i)^n / ((1+i)^n - 1)'
end program economic_pipe
Solver Description
Optimizes the pipe size by evaluating capital costs against pumping energy costs over the pipeline lifetime to identify the diameter with the lowest total lifecycle cost.
Key Numerical Methods & Architecture
- Input Redirection: Reads parameters sequentially from standard input (`stdin`) using Fortran sequential read (`read(*,*)`), ensuring modular integration.
- Modular Design: Formulated using pure mathematical routines, separation of equations from output formatting, and precise numerical solvers (e.g. bisection, Newton-Raphson).
- Standard Compliant: Written in clean, standards-compliant Fortran 90 to ensure cross-compiler compatibility.
🛠️ Local Compilation
To test this code on your machine, compile the source code file(s) using a standard Fortran compiler (e.g., `gfortran`).
Compilation Command:
gfortran -O3 economic_pipe.f90 -o economic_pipe
Execution Command:
Execute the program by feeding the sample input file into the program using stdin redirection:
economic_pipe < input.txt
📥 Downloads & Local Files
Preview of the required input file (input.txt):
! Flow rate Q [m3/s]
0.01
! Fluid density [kg/m3]
998.0
! Dynamic viscosity [Pa-s]
0.001
! Pipe capital cost factor [$/m per mm diameter]
0.50
! Electricity cost [$/kWh]
0.10
! Operating hours per year
8760.0
! Pumping efficiency [0-1]
0.70
! Friction factor (0=auto-calculate)
0.0
! Pipe length [m]
100.0
! Interest rate [%]
5.0
! System lifetime [years]
20.0
0.01
! Fluid density [kg/m3]
998.0
! Dynamic viscosity [Pa-s]
0.001
! Pipe capital cost factor [$/m per mm diameter]
0.50
! Electricity cost [$/kWh]
0.10
! Operating hours per year
8760.0
! Pumping efficiency [0-1]
0.70
! Friction factor (0=auto-calculate)
0.0
! Pipe length [m]
100.0
! Interest rate [%]
5.0
! System lifetime [years]
20.0