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Contents of /trunk/models/johnpye/fprops/combinedcycle_fprops.a4c

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Sun Aug 15 10:11:54 2010 UTC (13 years, 10 months ago) by jpye
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Trying to catch errors associated with pressure below triple point for CO2.
1 (* ASCEND modelling environment
2 Copyright (C) 2010 Carnegie Mellon University
3
4 This program is free software; you can redistribute it and/or modify
5 it under the terms of the GNU General Public License as published by
6 the Free Software Foundation; either version 2, or (at your option)
7 any later version.
8
9 This program is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 GNU General Public License for more details.
13
14 You should have received a copy of the GNU General Public License
15 along with this program; if not, write to the Free Software
16 Foundation, Inc., 59 Temple Place - Suite 330,
17 Boston, MA 02111-1307, USA.
18 *)(*
19 This file contains a model of a combined-cycle power station, with
20 a gas turbine (Brayton) cycle running as the 'topping' cycle and a steam
21 turbine (Rankine) cycle running as the 'bottoming' cycle. Initially the
22 model is being based on Example 9.13 from Moran & Shapiro, 'Fundamentals of
23 Engineering Thermodynamics', 4th Ed, Wiley, 2000.
24
25 See also Example 10-9 from the book Çengel & Boles
26 'Thermodynamcs: An Engineering Approach, 6th Ed, McGraw-Hill, 2008.
27
28 At the current revision (12 Apr 2010), this model seems to be working OK.
29 The Cengel model needs convopt=RELNOM_SCALE with the QRSlv solver. The
30 Moran example just works.
31
32 TODO: add exergy accounting to the model.
33
34 Author: John Pye
35 *)
36 IMPORT "johnpye/extpy/extpy";
37
38 IMPORT "johnpye/fprops/cycle_plot";
39
40 REQUIRE "johnpye/fprops/rankine_fprops.a4c";
41 REQUIRE "johnpye/brayton.a4c";
42
43 MODEL air_stream_heat_exchanger REFINES air_equipment;
44 inlet_cold, outlet_cold IS_A stream_node;
45 inlet.p, outlet.p ARE_THE_SAME;
46 inlet_cold.p, outlet_cold.p ARE_THE_SAME;
47 inlet_cold.mdot, outlet_cold.mdot ARE_THE_SAME;
48 inlet_cold.cd, outlet_cold.cd ARE_THE_SAME;
49
50 mdot_cold ALIASES inlet_cold.mdot;
51 cd_cold ALIASES inlet_cold.cd;
52
53 (* we don't have epsilon worked out or specified here, so the heat exchanged
54 will depend on values specified outside this model. *)
55
56 Qdot IS_A energy_rate;
57 outlet.h = inlet.h + Qdot/inlet.mdot;
58 outlet_cold.h = inlet_cold.h - Qdot/inlet_cold.mdot;
59 METHODS
60 METHOD default_self;
61 RUN inlet_cold.default_self;
62 RUN outlet_cold.default_self;
63 END default_self;
64 END air_stream_heat_exchanger;
65
66 MODEL air_stream_heat_exchanger_test REFINES air_stream_heat_exchanger;
67 cd_cold.component :== 'water';
68 METHODS
69 METHOD on_load;
70 RUN default_self;
71 FIX inlet_cold.p, inlet_cold.h;
72 inlet_cold.p := 50 {bar};
73 inlet_cold.h := 200 {kJ/kg};
74 FIX inlet.p, inlet.T;
75 inlet.p := 1 {bar};
76 inlet.T := 700 {K};
77 FIX mdot, mdot_cold;
78 mdot := 1 {kg/s};
79 mdot_cold := 0.1 {kg/s};
80 FIX Qdot;
81 Qdot := 10 {kW};
82 END on_load;
83 END air_stream_heat_exchanger_test;
84
85
86 MODEL combinedcycle_fprops_common;
87 (* define the blocks *)
88 GC IS_A compressor;
89 BU IS_A combustor;
90 GT IS_A gas_turbine;
91 HE IS_A air_stream_heat_exchanger;
92 DI IS_A dissipator;
93 TU IS_A turbine_simple;
94 CO IS_A condenser_simple;
95 PU IS_A pump_simple;
96
97 (* wire up the model *)
98 GC.outlet, BU.inlet ARE_THE_SAME;
99 BU.outlet, GT.inlet ARE_THE_SAME;
100 GT.outlet, HE.inlet ARE_THE_SAME;
101 HE.outlet, DI.inlet ARE_THE_SAME;
102 DI.outlet, GC.inlet ARE_THE_SAME;
103
104 HE.outlet_cold, TU.inlet ARE_THE_SAME;
105 TU.outlet, CO.inlet ARE_THE_SAME;
106 CO.outlet, PU.inlet ARE_THE_SAME;
107 PU.outlet, HE.inlet_cold ARE_THE_SAME;
108
109 cd_rankine ALIASES TU.inlet.cd;
110
111 Wdot, Wdot_gas, Wdot_vap IS_A energy_rate;
112 Wdot_gas = GC.Wdot + GT.Wdot;
113 Wdot_vap = TU.Wdot + PU.Wdot;
114 Wdot = Wdot_gas + Wdot_vap;
115
116 Qdot_H ALIASES BU.Qdot;
117
118 eta IS_A fraction;
119 eta = Wdot / Qdot_H;
120
121 massflowratio IS_A factor;
122 massflowratio = TU.mdot / GT.mdot;
123
124 braytonpressureratio IS_A positive_factor;
125 braytonpressureratio * GC.inlet.p = GC.outlet.p;
126
127 METHODS
128 METHOD default_self;
129 RUN TU.default_self;
130 RUN PU.default_self;
131 RUN CO.default_self;
132 RUN HE.default_self;
133 END default_self;
134 METHOD specify;
135 (* these values should be independent of the fluid we choose to use *)
136 FIX GC.eta; GC.eta := 0.84;
137 FIX GT.eta; GT.eta := 0.88;
138 FIX TU.eta; TU.eta := 0.90;
139 FIX PU.eta; PU.eta := 0.8;
140 FIX CO.outlet.x; CO.outlet.x := 1e-6;
141 FIX BU.eta; BU.eta := 1;
142 END specify;
143 METHOD cycle_plot;
144 EXTERNAL cycle_plot(SELF);
145 END cycle_plot;
146 END combinedcycle_fprops_common;
147
148 MODEL combinedcycle_water REFINES combinedcycle_fprops_common;
149 TU.inlet.cd.component :== 'water';
150 METHODS
151 METHOD default_self;
152 RUN combinedcycle_fprops_common::default_self;
153 (* starting guess, for easy solving *)
154 HE.outlet_cold.h := 3000 {kJ/kg};
155 END default_self;
156 METHOD on_load;
157 RUN ClearAll;
158 RUN default_self;
159 RUN combinedcycle_fprops_common::specify;
160 FIX Wdot; Wdot := 100 {MW};
161 FIX GC.inlet.T, GC.inlet.p;
162 GC.inlet.T := 300 {K};
163 GC.inlet.p := 1 {bar};
164 FIX CO.outlet.p; CO.outlet.p := 8 {kPa};
165
166 (* optimisable *)
167 FIX braytonpressureratio; braytonpressureratio := 8;
168
169 FIX HE.outlet.T; HE.outlet.T := 400 {K};
170 FIX BU.outlet.T; BU.outlet.T := 1300 {K};
171 FIX TU.inlet.T; TU.inlet.T := 600 {K};
172 FIX TU.inlet.p; TU.inlet.p := 50 {bar};
173 END on_load;
174 END combinedcycle_water;
175
176
177 MODEL combinedcycle_co2 REFINES combinedcycle_fprops_common;
178 TU.inlet.cd.component :== 'carbondioxide';
179 METHODS
180 METHOD default_self;
181 RUN combinedcycle_fprops_common::default_self;
182 (* starting guess, for easy solving *)
183 HE.outlet_cold.h := 200 {kJ/kg};
184 CO.outlet.h := 200 {kJ/kg};
185 END default_self;
186 METHOD on_load;
187 RUN ClearAll;
188 RUN default_self;
189 RUN combinedcycle_fprops_common::specify;
190 FIX Wdot; Wdot := 100 {MW};
191 FIX GC.inlet.T, GC.inlet.p;
192 GC.inlet.T := 300 {K};
193 GC.inlet.p := 1 {bar};
194 FIX CO.outlet.p; CO.outlet.p := 5.2 {bar};
195
196 (* optimisable *)
197 FIX braytonpressureratio; braytonpressureratio := 8;
198
199 FIX HE.outlet.T; HE.outlet.T := 400 {K};
200 FIX BU.outlet.T; BU.outlet.T := 1300 {K};
201 FIX TU.inlet.T; TU.inlet.T := 600 {K};
202 FIX TU.inlet.p; TU.inlet.p := 50 {bar};
203
204 SOLVER QRSlv;
205 OPTION convopt 'RELNOM_SCALE';
206 END on_load;
207 END combinedcycle_co2;
208
209
210 MODEL combinedcycle_toluene REFINES combinedcycle_fprops_common;
211 TU.inlet.cd.component :== 'toluene';
212 METHODS
213 METHOD default_self;
214 RUN combinedcycle_fprops_common::default_self;
215 (* starting guess, for easy solving *)
216 HE.outlet_cold.h := 400 {kJ/kg};
217 CO.outlet.h := 400 {kJ/kg};
218 END default_self;
219 METHOD on_load;
220 RUN ClearAll;
221 RUN default_self;
222 RUN combinedcycle_fprops_common::specify;
223 FIX Wdot; Wdot := 100 {MW};
224 FIX GC.inlet.T, GC.inlet.p;
225 GC.inlet.T := 300 {K};
226 GC.inlet.p := 1 {bar};
227 FIX CO.outlet.p; CO.outlet.p := 8 {kPa};
228
229 (* optimisable *)
230 FIX braytonpressureratio; braytonpressureratio := 8;
231
232 FIX HE.outlet.T; HE.outlet.T := 400 {K};
233 FIX BU.outlet.T; BU.outlet.T := 1300 {K};
234 FIX TU.inlet.T; TU.inlet.T := 600 {K};
235 FIX TU.inlet.p; TU.inlet.p := 50 {bar};
236
237 SOLVER QRSlv;
238 OPTION convopt 'RELNOM_SCALE';
239 END on_load;
240 END combinedcycle_toluene;
241
242
243
244
245
246 MODEL combinedcycle_fprops REFINES combinedcycle_water;
247 METHODS
248 METHOD on_load;
249 RUN default_self;
250 RUN cengel_ex_10_9;
251 SOLVER QRSlv;
252 OPTION convopt 'RELNOM_SCALE';
253 END on_load;
254
255 METHOD moran_ex_9_13;
256 RUN ClearAll;
257 FIX Wdot; Wdot := 45 {MW};
258
259 FIX GC.inlet.T, GC.inlet.p;
260 GC.inlet.T := 300 {K};
261 GC.inlet.p := 100 {kPa};
262
263 FIX GC.outlet.p;
264 GC.outlet.p := 1200 {kPa};
265
266 FIX GC.eta; GC.eta := 0.84;
267
268 FIX BU.outlet.T; BU.outlet.T := 1400 {K};
269
270 FIX GT.eta; GT.eta := 0.88;
271
272 (* GT.outlet.p := 100 {kPa};*)
273 FIX HE.outlet.T; HE.outlet.T := 400 {K};
274
275 FIX TU.inlet.T, TU.inlet.p;
276 TU.inlet.T := 400 {K} + 273.15 {K};
277 TU.inlet.p := 8 {MPa};
278 FIX TU.outlet.p; TU.outlet.p := 8 {kPa};
279
280 FIX PU.inlet.x;
281 PU.inlet.x := 0.0001;
282
283 FIX TU.eta; TU.eta := 0.90;
284 FIX PU.eta; PU.eta := 0.8;
285
286 (* assumed *)
287 FIX BU.eta;
288 BU.eta := 1;
289 END moran_ex_9_13;
290
291 METHOD cengel_ex_10_9;
292 RUN ClearAll;
293 FIX Wdot; Wdot := 100 {MW};
294
295 FIX GC.inlet.p; GC.inlet.p := 1 {atm}; (* assumed *)
296
297 FIX braytonpressureratio; braytonpressureratio := 8;
298
299 FIX GC.inlet.T; GC.inlet.T := 300 {K};
300 FIX GT.inlet.T; GT.inlet.T := 1300 {K};
301
302 FIX GC.eta; GC.eta := 0.8;
303 FIX GT.eta; GT.eta := 0.85;
304
305 FIX TU.inlet.p; TU.inlet.p := 7 {MPa};
306 FIX CO.outlet.p; CO.outlet.p := 5 {kPa};
307
308 FIX TU.inlet.T; TU.inlet.T := 500 {K} + 273.15 {K};
309 FIX DI.inlet.T; DI.inlet.T := 450 {K};
310
311 (* 'complete' condensation... bit of a hack *)
312 FIX CO.outlet.x; CO.outlet.x := 0.0001;
313
314 (* 'simple ideal Rankine cycle *)
315 FIX TU.eta; TU.eta := 1;
316 FIX BU.eta; BU.eta := 1;
317 FIX PU.eta; PU.eta := 1;
318
319 (* first guess, for easy solving *)
320 HE.outlet_cold.h := 3000 {kJ/kg};
321 END cengel_ex_10_9;
322
323 END combinedcycle_fprops;

john.pye@anu.edu.au
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