MULTISTAGE
*
* OPTIMAL CYCLIC SCHEDULING OF MULTISTAGE
CONTINUOUS
* MULTIPRODUCT PLANTS
* J. M. Pinto and I. E. Grossmann
* Department of Chemical Engineering,
Carnegie Mellon University
* Pittsburgh, PA 15213, U.S.A.
* Ref: Computers chem. Engng Vol. 18, No.
9, pp. 797-816, 1994
SETS I PRODUCTS / A,B,C /
K TIME SLOTS / 1*3 /
M STAGES / 1*2 /
PARAMETER TCUP UPPER BOUND ON THE CYCLE
TIME (hr);
TCUP = 300;
PARAMETER PD(I) DEMAND (kg/h) /
A 50.00
B 100.00
C 150.00
/;
PARAMETER P(I) PRODUCT PRICES ($ per ton)
/
A 150
B 400
C 650 /;
PARAMETER ALPHA (K,M) MASS TRANSFER
COEFFICIENT;
ALPHA (K,M) = 1;
* SEQUENCE OPTIMIZATION
SCALAR SEQUENCE fix sequence /0/;
* FIXED SEQUENCE
BINARY VARIABLE Y(I,K);
Y.FX('A', '1') = 1;
Y.FX('B', '2') = 1;
Y.FX('C', '3') = 1;
* FORBIDDEN ASSIGNMENTS
PARAMETER YFOR(I,K) FORBIDDEN ASSIGNMENTS
(REPORT);
YFOR(I,K) = 0;
* SEQUENCING CONSTRAINTS
PARAMETER SEQCO(I,J);
SEQCO(I,J) = 0;
SCALAR SEQCONS /0/;
EQUATION SEQ(I,J,K);
POSITIVE VARIABLE Z(I,J,K);
SEQ(I,J,K)$(SEQCONS EQ 1 AND ORD(K) NE
CARD(K) ) ..
Z(I,J,K) =L= Z(I,J, K++1);
TABLE TAU(I,J,M) TRANSITION TIMES (hr)
A.1 B.1 C.1 A.2 B.2 C.2
A - 10 3 - 7 3
B 3 - 6 3 - 10
C 8 3 - 3 0 -
TABLE GAMAP(I,M) PROCESSING RATES (ton
per hr)
1 2
A 0.80 0.90
B 1.20 0.60
C 1.00 1.10
TABLE CINV(I,M) INVESTMENT COST
COEFFICIENT FOR INVENTORY
*($ per ton per hr)
1 2
A 140.6 4.06
B 140.6 4.06
C 140.6 4.06
TABLE CTR(I,J) TRANSITION COSTS ($ PER
TON)
A B C
A 0 760 760
B 750 0 750
C 770 770 0
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