# Heat exchanger design # Ref.: W. Hock and K. Schittkowski, Test Examples for Nonlinear Programming # Codes. Lecture Notes in Economics and Mathematical Systems, v. 187, # Springer-Verlag, New York, 1981, p. 115. # Number of variables: 8 # Number of constraints: 22 Model hs106 Parameters a = 0.0025, >0 b = 0.01, >0 c = 833.3325, >0 d = 100, >0 e = 83333.33, >0 f = 1250, >0 g = 1250000, >0 h = 2500, >0 End Parameters Variables x[1] = 5000 x[2] = 5000 x[3] = 5000 x[4] = 200 x[5] = 350 x[6] = 150 x[7] = 225 x[8] = 425 obj End Variables Equations 1 - a * (x[4] + x[6]) >= 0 1 - a * (x[5] + x[7] - x[4]) >= 0 1 - b * (x[8] - x[5]) >= 0 x[1] * x[6] - c * x[4] - d * x[1] + e >= 0 x[2] * x[7] - f * x[5] - x[2] * x[4] + f * x[4] >= 0 x[3] * x[8] - g - x[3] * x[5] + h * x[5] >= 0 100 <= x[1] <= 10000 1000 <= x[2:3] <= 10000 10 <= x[4:8] <= 1000 ! best known objective = 7049.330923 obj = x[1] + x[2] + x[3] End Equations End Model