johnpye/fprops/combinedcycle_fprops.a4c

(*	ASCEND modelling environment
	Copyright (C) 2010 Carnegie Mellon University

	This program is free software; you can redistribute it and/or modify
	it under the terms of the GNU General Public License as published by
	the Free Software Foundation; either version 2, or (at your option)
	any later version.

	This program is distributed in the hope that it will be useful,
	but WITHOUT ANY WARRANTY; without even the implied warranty of
	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
	GNU General Public License for more details.
	
	You should have received a copy of the GNU General Public License
	along with this program; if not, write to the Free Software
	Foundation, Inc., 59 Temple Place - Suite 330,
	Boston, MA 02111-1307, USA.
*)(*
	This file contains a model of a combined-cycle power station, with
	a gas turbine (Brayton) cycle running as the 'topping' cycle and a steam
	turbine (Rankine) cycle running as the 'bottoming' cycle. Initially the 
	model is being based on Example 9.13 from Moran & Shapiro, 'Fundamentals of
	Engineering Thermodynamics', 4th Ed, Wiley, 2000.

	See also Example 10-9 from the book Çengel & Boles 
	'Thermodynamcs: An Engineering Approach, 6th Ed, McGraw-Hill, 2008.

	At the current revision (12 Apr 2010), this model seems to be working OK.
	The Cengel model needs convopt=RELNOM_SCALE with the QRSlv solver. The
	Moran example just works.

	TODO: add exergy accounting to the model.

	Author: John Pye
*)
IMPORT "johnpye/extpy/extpy";

IMPORT "johnpye/fprops/cycle_plot";

REQUIRE "johnpye/fprops/rankine_fprops.a4c";
REQUIRE "johnpye/brayton.a4c";

MODEL air_stream_heat_exchanger REFINES air_equipment;
	inlet_cold, outlet_cold IS_A stream_node;
	inlet.p, outlet.p ARE_THE_SAME;
	inlet_cold.p, outlet_cold.p ARE_THE_SAME;
	inlet_cold.mdot, outlet_cold.mdot ARE_THE_SAME;
	inlet_cold.cd, outlet_cold.cd ARE_THE_SAME;

	mdot_cold ALIASES inlet_cold.mdot;
	cd_cold ALIASES inlet_cold.cd;

	(* we don't have epsilon worked out or specified here, so the heat exchanged
	will depend on values specified outside this model. *)

	Qdot IS_A energy_rate;
	outlet.h = inlet.h + Qdot/inlet.mdot;
	outlet_cold.h = inlet_cold.h - Qdot/inlet_cold.mdot;
METHODS
METHOD default_self;
	RUN inlet_cold.default_self;
	RUN outlet_cold.default_self;
END default_self;
END air_stream_heat_exchanger;

MODEL air_stream_heat_exchanger_test REFINES air_stream_heat_exchanger;
	cd_cold.component :== 'water';
METHODS
METHOD on_load;
	RUN default_self;
	FIX inlet_cold.p, inlet_cold.h;
	inlet_cold.p := 50 {bar};
	inlet_cold.h := 200 {kJ/kg};
	FIX inlet.p, inlet.T;
	inlet.p := 1 {bar};
	inlet.T := 700 {K};
	FIX mdot, mdot_cold;
	mdot := 1 {kg/s};
	mdot_cold := 0.1 {kg/s};
	FIX Qdot;
	Qdot := 10 {kW};
END on_load;
END air_stream_heat_exchanger_test;


MODEL combinedcycle_fprops_common;
	(* define the blocks *)
	GC IS_A compressor;
	BU IS_A combustor;
	GT IS_A gas_turbine;
	HE IS_A air_stream_heat_exchanger;
	DI IS_A dissipator;
	TU IS_A turbine_simple;
	CO IS_A condenser_simple;
	PU IS_A pump_simple;

	(* wire up the model *)
	GC.outlet, BU.inlet ARE_THE_SAME;
	BU.outlet, GT.inlet ARE_THE_SAME;
	GT.outlet, HE.inlet ARE_THE_SAME;
	HE.outlet, DI.inlet ARE_THE_SAME;
	DI.outlet, GC.inlet ARE_THE_SAME;

	HE.outlet_cold, TU.inlet ARE_THE_SAME;
	TU.outlet, CO.inlet ARE_THE_SAME;
	CO.outlet, PU.inlet ARE_THE_SAME;
	PU.outlet, HE.inlet_cold ARE_THE_SAME;

	cd_rankine ALIASES TU.inlet.cd;

	Wdot, Wdot_gas, Wdot_vap IS_A energy_rate;
	Wdot_gas = GC.Wdot + GT.Wdot;
	Wdot_vap = TU.Wdot + PU.Wdot;
	Wdot = Wdot_gas + Wdot_vap;

	Qdot_H ALIASES BU.Qdot;
	
	eta IS_A fraction;
	eta = Wdot / Qdot_H;

	massflowratio IS_A factor;
	massflowratio = TU.mdot / GT.mdot;

	braytonpressureratio IS_A positive_factor;
	braytonpressureratio * GC.inlet.p = GC.outlet.p;

METHODS
METHOD default_self;
	RUN TU.default_self;
	RUN PU.default_self;
	RUN CO.default_self;
	RUN HE.default_self;
END default_self;
METHOD specify;
	(* these values should be independent of the fluid we choose to use *)
	FIX GC.eta; GC.eta := 0.84;
	FIX GT.eta; GT.eta := 0.88;
	FIX TU.eta; TU.eta := 0.90;
	FIX PU.eta; PU.eta := 0.8;
	FIX CO.outlet.x; CO.outlet.x := 1e-6;
	FIX BU.eta; BU.eta := 1;
END specify;
METHOD cycle_plot;
	EXTERNAL cycle_plot(SELF);
END cycle_plot;
END combinedcycle_fprops_common;

MODEL combinedcycle_water REFINES combinedcycle_fprops_common;
	TU.inlet.cd.component :== 'water';
METHODS
METHOD default_self;
	RUN combinedcycle_fprops_common::default_self;
	(* starting guess, for easy solving *)
	HE.outlet_cold.h := 3000 {kJ/kg};
END default_self;
METHOD on_load;
	RUN ClearAll;
	RUN default_self;
	RUN combinedcycle_fprops_common::specify;
	FIX Wdot; Wdot := 100 {MW};
	FIX GC.inlet.T, GC.inlet.p;
	GC.inlet.T := 300 {K};
	GC.inlet.p := 1 {bar};
	FIX CO.outlet.p; CO.outlet.p := 8 {kPa};

	(* optimisable *)
	FIX braytonpressureratio; braytonpressureratio := 8;

	FIX HE.outlet.T; HE.outlet.T := 400 {K};
	FIX BU.outlet.T; BU.outlet.T := 1300 {K};
	FIX TU.inlet.T; TU.inlet.T := 600 {K};
	FIX TU.inlet.p; TU.inlet.p := 50 {bar};
END on_load;
END combinedcycle_water;


MODEL combinedcycle_co2 REFINES combinedcycle_fprops_common;
	TU.inlet.cd.component :== 'carbondioxide';
METHODS
METHOD default_self;
	RUN combinedcycle_fprops_common::default_self;
	(* starting guess, for easy solving *)
	HE.outlet_cold.h := 200 {kJ/kg};
	CO.outlet.h := 200 {kJ/kg};
END default_self;
METHOD on_load;
	RUN ClearAll;
	RUN default_self;
	RUN combinedcycle_fprops_common::specify;
	FIX Wdot; Wdot := 100 {MW};
	FIX GC.inlet.T, GC.inlet.p;
	GC.inlet.T := 300 {K};
	GC.inlet.p := 1 {bar};
	FIX CO.outlet.p; CO.outlet.p := 5.2 {bar};

	(* optimisable *)
	FIX braytonpressureratio; braytonpressureratio := 8;

	FIX HE.outlet.T; HE.outlet.T := 400 {K};
	FIX BU.outlet.T; BU.outlet.T := 1300 {K};
	FIX TU.inlet.T; TU.inlet.T := 600 {K};
	FIX TU.inlet.p; TU.inlet.p := 50 {bar};

	SOLVER QRSlv;
	OPTION convopt 'RELNOM_SCALE';
END on_load;
END combinedcycle_co2;


MODEL combinedcycle_toluene REFINES combinedcycle_fprops_common;
	TU.inlet.cd.component :== 'toluene';
METHODS
METHOD default_self;
	RUN combinedcycle_fprops_common::default_self;
	(* starting guess, for easy solving *)
	HE.outlet_cold.h := 400 {kJ/kg};
	CO.outlet.h := 400 {kJ/kg};
END default_self;
METHOD on_load;
	RUN ClearAll;
	RUN default_self;
	RUN combinedcycle_fprops_common::specify;
	FIX Wdot; Wdot := 100 {MW};
	FIX GC.inlet.T, GC.inlet.p;
	GC.inlet.T := 300 {K};
	GC.inlet.p := 1 {bar};
	FIX CO.outlet.p; CO.outlet.p := 8 {kPa};

	(* optimisable *)
	FIX braytonpressureratio; braytonpressureratio := 8;

	FIX HE.outlet.T; HE.outlet.T := 400 {K};
	FIX BU.outlet.T; BU.outlet.T := 1300 {K};
	FIX TU.inlet.T; TU.inlet.T := 600 {K};
	FIX TU.inlet.p; TU.inlet.p := 50 {bar};

	SOLVER QRSlv;
	OPTION convopt 'RELNOM_SCALE';
END on_load;
END combinedcycle_toluene;


MODEL combinedcycle_fprops REFINES combinedcycle_water;
METHODS
METHOD on_load;
	RUN default_self;
	RUN cengel_ex_10_9;
	SOLVER QRSlv;
	OPTION convopt 'RELNOM_SCALE';
END on_load;

METHOD moran_ex_9_13;
	RUN ClearAll;
	FIX Wdot; Wdot := 45 {MW};

	FIX GC.inlet.T, GC.inlet.p;
	GC.inlet.T := 300 {K};
	GC.inlet.p := 100 {kPa};

	FIX GC.outlet.p;
	GC.outlet.p := 1200 {kPa};

	FIX GC.eta; GC.eta := 0.84;

	FIX BU.outlet.T; BU.outlet.T := 1400 {K};

	FIX GT.eta; GT.eta := 0.88;

	(* GT.outlet.p := 100 {kPa};*)
	FIX HE.outlet.T; HE.outlet.T := 400 {K};
	
	FIX TU.inlet.T, TU.inlet.p;
	TU.inlet.T := 400 {K} +  273.15 {K};
	TU.inlet.p := 8 {MPa};
	FIX TU.outlet.p; TU.outlet.p := 8 {kPa};

	FIX PU.inlet.x;
	PU.inlet.x := 0.0001;

	FIX TU.eta; TU.eta := 0.90;
	FIX PU.eta; PU.eta := 0.8;

	(* assumed *)
	FIX BU.eta;
	BU.eta := 1;
END moran_ex_9_13;

METHOD cengel_ex_10_9;
	RUN ClearAll;
	FIX Wdot; Wdot := 100 {MW};

	FIX GC.inlet.p; GC.inlet.p := 1 {atm}; (* assumed *)

	FIX braytonpressureratio; braytonpressureratio := 8;

	FIX GC.inlet.T; GC.inlet.T := 300 {K};
	FIX GT.inlet.T; GT.inlet.T := 1300 {K};

	FIX GC.eta; GC.eta := 0.8;
	FIX GT.eta; GT.eta := 0.85;

	FIX TU.inlet.p; TU.inlet.p := 7 {MPa};
	FIX CO.outlet.p; CO.outlet.p := 5 {kPa};

	FIX TU.inlet.T; TU.inlet.T := 500 {K} +  273.15 {K};
	FIX DI.inlet.T; DI.inlet.T := 450 {K};

	(* 'complete' condensation... bit of a hack *)
	FIX CO.outlet.x; CO.outlet.x := 0.0001;

	(* 'simple ideal Rankine cycle *)
	FIX TU.eta; TU.eta := 1;
	FIX BU.eta; BU.eta := 1;
	FIX PU.eta; PU.eta := 1;

	(* first guess, for easy solving *)
	HE.outlet_cold.h := 3000 {kJ/kg};
END cengel_ex_10_9;

END combinedcycle_fprops;
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;