1 | #*------------------------------------------------------------------- |
---|
2 | * EMSO Model Library (EML) Copyright (C) 2004 - 2008 ALSOC. |
---|
3 | * |
---|
4 | * This LIBRARY is free software; you can distribute it and/or modify |
---|
5 | * it under the therms of the ALSOC FREE LICENSE as available at |
---|
6 | * http://www.enq.ufrgs.br/alsoc. |
---|
7 | * |
---|
8 | * EMSO Copyright (C) 2004 - 2008 ALSOC, original code |
---|
9 | * from http://www.rps.eng.br Copyright (C) 2002-2004. |
---|
10 | * All rights reserved. |
---|
11 | * |
---|
12 | * EMSO is distributed under the therms of the ALSOC LICENSE as |
---|
13 | * available at http://www.enq.ufrgs.br/alsoc. |
---|
14 | * |
---|
15 | *-------------------------------------------------------------------- |
---|
16 | * Sample file for controllers |
---|
17 | *---------------------------------------------------------------------- |
---|
18 | * Author: Argimiro R. Secchi |
---|
19 | * $Id: CSTR_noniso_pid.mso 536 2008-06-15 23:18:35Z arge $ |
---|
20 | *--------------------------------------------------------------------*# |
---|
21 | |
---|
22 | using "controllers/PIDs"; |
---|
23 | |
---|
24 | const_valv as positive(Brief = "Valve Constant", Default=1,Lower=0,Upper=100, Unit='m^2.5/h'); |
---|
25 | |
---|
26 | Model stream_cstr |
---|
27 | VARIABLES |
---|
28 | Ca as conc_mol; |
---|
29 | F as flow_vol; |
---|
30 | T as temperature; |
---|
31 | end |
---|
32 | |
---|
33 | Model CSTR |
---|
34 | |
---|
35 | PARAMETERS |
---|
36 | ko as frequency (DisplayUnit='1/h'); |
---|
37 | D as length; |
---|
38 | A as area; |
---|
39 | Ea as energy_mol (DisplayUnit='kJ/kmol'); |
---|
40 | R as Real (Unit='kJ/mol/K'); |
---|
41 | ro as dens_mass (DisplayUnit='kg/m^3'); |
---|
42 | Cp as cp_mass (DisplayUnit='kJ/kg/K'); |
---|
43 | U as heat_trans_coeff (DisplayUnit='kW/m^2/K'); |
---|
44 | Hr as heat_reaction (DisplayUnit='kJ/kmol'); |
---|
45 | pi as Real (Default = 3.141593); |
---|
46 | Cv as const_valv; |
---|
47 | |
---|
48 | VARIABLES |
---|
49 | At as area; |
---|
50 | T as temperature; |
---|
51 | Tw as temperature; |
---|
52 | x as fraction; |
---|
53 | V as volume; |
---|
54 | Ca as conc_mol; |
---|
55 | h as length; |
---|
56 | tau as time_h; |
---|
57 | rA as reaction_mol; |
---|
58 | k as frequency (DisplayUnit='1/h'); |
---|
59 | q as heat_rate (DisplayUnit='kJ/h'); |
---|
60 | qr as heat_rate (DisplayUnit='kJ/h'); |
---|
61 | in Inlet as stream_cstr; |
---|
62 | out Outlet as stream_cstr; |
---|
63 | |
---|
64 | SET |
---|
65 | A = pi * D^2 / 4; |
---|
66 | |
---|
67 | EQUATIONS |
---|
68 | |
---|
69 | "Overall Mass Balance" |
---|
70 | diff(V) = Inlet.F - Outlet.F; |
---|
71 | |
---|
72 | "Component Mass Balance" |
---|
73 | V * diff(Ca) = Inlet.F * (Inlet.Ca - Ca) - (-rA) * V; |
---|
74 | |
---|
75 | "Average Residence Time" |
---|
76 | tau * Inlet.F = V; |
---|
77 | |
---|
78 | "Energy Balance" |
---|
79 | ro * V * Cp * diff(T) = Inlet.F * ro * Cp * (Inlet.T - T) + qr - q; |
---|
80 | |
---|
81 | "Heat Transfer Rate" |
---|
82 | q = U * At * (T - Tw); |
---|
83 | |
---|
84 | "Reaction Heat Rate" |
---|
85 | qr = (-Hr) * (-rA) * V; |
---|
86 | |
---|
87 | "Reaction Rate" |
---|
88 | -rA = k * Ca; |
---|
89 | |
---|
90 | "Arrhenius Equation" |
---|
91 | k = ko * exp(-Ea/(R*T)); |
---|
92 | |
---|
93 | "Geometry" |
---|
94 | A * h = V; |
---|
95 | At = A + pi*D*h; |
---|
96 | |
---|
97 | "Valve Equation" |
---|
98 | Outlet.F = x * Cv * sqrt(h); |
---|
99 | |
---|
100 | "Perfect Mixture" |
---|
101 | Outlet.Ca = Ca; |
---|
102 | Outlet.T = T; |
---|
103 | end |
---|
104 | |
---|
105 | # Process with controlled CSTR and multiple steady-states |
---|
106 | FlowSheet CSTR_controller |
---|
107 | |
---|
108 | DEVICES |
---|
109 | FEED as stream_cstr; |
---|
110 | CSTR1 as CSTR; |
---|
111 | PIDL as PID; |
---|
112 | PIDT as PID; |
---|
113 | |
---|
114 | VARIABLES |
---|
115 | L_ad as Real; |
---|
116 | Lmin as length; |
---|
117 | Lmax as length; |
---|
118 | T_ad as Real; |
---|
119 | Tmin as temperature; |
---|
120 | Tmax as temperature; |
---|
121 | Lsp as length; |
---|
122 | Tsp as temperature; |
---|
123 | |
---|
124 | CONNECTIONS |
---|
125 | FEED to CSTR1.Inlet; |
---|
126 | |
---|
127 | SET |
---|
128 | # CSTR Parameters |
---|
129 | CSTR1.R = 8.3144 * 'kJ/kmol/K'; |
---|
130 | CSTR1.U = 300 * 'kJ/h/m^2/K'; |
---|
131 | CSTR1.ro = 1000 * 'kg/m^3'; |
---|
132 | CSTR1.Cp = 4*'kJ/kg/K'; |
---|
133 | CSTR1.Hr = -7000 * 'kJ/kmol'; |
---|
134 | CSTR1.Ea = 6e4 * 'kJ/kmol'; |
---|
135 | CSTR1.ko = 89 * '1/s'; |
---|
136 | CSTR1.D = 3.2 * 'm'; |
---|
137 | CSTR1.Cv = 2.7 * 'm^2.5/h'; |
---|
138 | |
---|
139 | PIDL.PID_Select = "Ideal_AWBT"; |
---|
140 | PIDT.PID_Select = "Ideal_AWBT"; |
---|
141 | |
---|
142 | EQUATIONS |
---|
143 | |
---|
144 | "Dimensionless level to connect PID" |
---|
145 | L_ad*(Lmax-Lmin)=CSTR1.h-Lmin; |
---|
146 | PIDL.Ports.input=L_ad; |
---|
147 | |
---|
148 | "Dimensionless temperature to connect PID" |
---|
149 | T_ad*(Tmax-Tmin)=CSTR1.T-Tmin; |
---|
150 | PIDT.Ports.input=T_ad; |
---|
151 | |
---|
152 | "Manipulated Variables" |
---|
153 | CSTR1.x = PIDL.Ports.output; |
---|
154 | CSTR1.Tw = PIDT.Ports.output*(Tmax-Tmin)+Tmin; |
---|
155 | |
---|
156 | # Level control: PID parameters |
---|
157 | PIDL.Parameters.bias=0; |
---|
158 | PIDL.Parameters.alpha=0.1; |
---|
159 | PIDL.Options.action=-1; |
---|
160 | PIDL.Parameters.gamma=1; |
---|
161 | PIDL.Parameters.beta=1; |
---|
162 | PIDL.Options.clip=1; |
---|
163 | PIDL.Options.autoMan=0; |
---|
164 | PIDL.Parameters.gain=1; |
---|
165 | PIDL.Parameters.intTime=2.5*'h'; |
---|
166 | PIDL.Parameters.derivTime=0*'s'; |
---|
167 | PIDL.Ports.setPoint=(Lsp - Lmin)/(Lmax - Lmin); |
---|
168 | PIDL.Parameters.tau=1*'s'; |
---|
169 | PIDL.Parameters.tauSet=1*'s'; |
---|
170 | |
---|
171 | # Temperature control: PID parameters |
---|
172 | PIDT.Parameters.bias = 0; |
---|
173 | PIDT.Parameters.alpha=0.1; |
---|
174 | PIDT.Options.action=1; |
---|
175 | PIDT.Parameters.gamma=1; |
---|
176 | PIDT.Parameters.beta=1; |
---|
177 | PIDT.Options.clip=1; |
---|
178 | PIDT.Options.autoMan=0; |
---|
179 | PIDT.Parameters.gain=1; |
---|
180 | PIDT.Parameters.intTime=2.5*'h'; |
---|
181 | PIDT.Parameters.derivTime=1*'h'; |
---|
182 | PIDT.Ports.setPoint=(Tsp - Tmin)/(Tmax - Tmin); |
---|
183 | PIDT.Parameters.tau=1*'s'; |
---|
184 | PIDT.Parameters.tauSet=1*'s'; |
---|
185 | |
---|
186 | "Operating range for control variables" |
---|
187 | Lmax=5*'m'; |
---|
188 | Lmin=0*'m'; |
---|
189 | Tmax=700*'K'; |
---|
190 | Tmin=230*'K'; |
---|
191 | |
---|
192 | "Feed Stream" |
---|
193 | FEED.Ca = 300 * 'kmol/m^3'; |
---|
194 | FEED.F = 3.5 * 'm^3/h'; |
---|
195 | |
---|
196 | # Disturbance |
---|
197 | if time < 50 * 'h' then |
---|
198 | FEED.T = 300 * 'K'; |
---|
199 | else |
---|
200 | FEED.T = 285 * 'K'; # change to 350 K to saturate controller |
---|
201 | end |
---|
202 | |
---|
203 | # Set-point changes |
---|
204 | if time < 100 * 'h' then |
---|
205 | Tsp = 630 * 'K'; |
---|
206 | else |
---|
207 | Tsp = 400 * 'K'; |
---|
208 | end |
---|
209 | |
---|
210 | if time < 150 * 'h' then |
---|
211 | Lsp = 1.7 * 'm'; |
---|
212 | else |
---|
213 | Lsp = 4 * 'm'; |
---|
214 | end |
---|
215 | |
---|
216 | INITIAL |
---|
217 | CSTR1.Ca = 50 * 'kmol/m^3'; |
---|
218 | CSTR1.h = 1.7 * 'm'; |
---|
219 | CSTR1.T = 570 * 'K'; |
---|
220 | |
---|
221 | OPTIONS |
---|
222 | TimeStep = 1; |
---|
223 | TimeEnd = 250; |
---|
224 | TimeUnit = 'h'; |
---|
225 | DAESolver(File = "dassl"); |
---|
226 | end |
---|