models/steam/thermalequilibrium3.a4c

REQUIRE "ivpsystem.a4l";
REQUIRE "johnpye/thermo_types.a4c";
REQUIRE "johnpye/steam/iapwssat.a4c";

IMPORT "johnpye/extpy/extpy";
IMPORT "johnpye/listnotes";
IMPORT "johnpye/solve";

(* 
	Simplified version of models/johnpye/thermalequilibrium2.a4c. This one uses
	saturated steam properties only (and is not suitable for cases where
	properties pass outside those limits).

	NOTE: set the starting step to 0.1 and the minimum step to 0.01 s, and
	integrate from 0 to 3000 s.
*)
ADD NOTES IN thermalequilibrium3;
	'solver' name {QRSlv}
	'QRSlv' iterationlimit {50}
	'QRSlv' singtol {1e-10}
	(* following are not implemented yet *)
	'LSODE' minstep {0.01} 
	'LSODE' firststep {0.1}
	'LSODE' duration {3000}
END NOTES;

MODEL thermalequilibrium3;
	S[1..2] IS_A iapwssat;
	m[1..2] IS_A mass;
	h IS_A heat_transfer_coefficient;
	A IS_A area;

	p ALIASES S[1].p;
	S[2].p = S[1].p;

	Q IS_A energy_rate;
	Q = h*A*(S[1].T - S[2].T); (* rate of heat transfer from 1 to 2 *)
	m[1]*dhdt[1] = -Q;
	m[2]*dhdt[2] = +Q;
	
	dhdt[1..2] IS_A delta_specific_power;

	t IS_A time;
METHODS
METHOD specify;
	FIX	h, A, m[1..2], S[1..2].h, p;
END specify;	
METHOD values;
	A := 1 {m^2};
	h := 10 {W/m^2/K};

	p := 1 {bar};

	m[1] := 2 {kg};
	S[1].h := 1000 {kJ/kg};
	m[2] := 10 {kg};
	S[2].h := 2000 {kJ/kg};
END values;
METHOD ode_init;
	FOR i IN [1..2] DO
		S[i].h.ode_id := i;
		dhdt[i].ode_id := i;
		S[i].h.ode_type := 1;
		dhdt[i].ode_type := 2;
	END FOR;

	Q.obs_id := 2;
	S[1].h.obs_id := 3;
	S[2].h.obs_id := 4;

	t.ode_type := -1;
	t := 0 {s};
END ode_init;
METHOD on_load;
	RUN reset;
	RUN values;
	EXTERNAL setup_solver(SELF);
	EXTERNAL solve(SELF);
	RUN ode_init;
END on_load;

END thermalequilibrium3;
1	REQUIRE "ivpsystem.a4l";
2	REQUIRE "johnpye/thermo_types.a4c";
3	REQUIRE "johnpye/steam/iapwssat.a4c";
4
5	IMPORT "johnpye/extpy/extpy";
6	IMPORT "johnpye/listnotes";
7	IMPORT "johnpye/solve";
8
9	(*
10	Simplified version of models/johnpye/thermalequilibrium2.a4c. This one uses
11	saturated steam properties only (and is not suitable for cases where
12	properties pass outside those limits).
13
14	NOTE: set the starting step to 0.1 and the minimum step to 0.01 s, and
15	integrate from 0 to 3000 s.
16	*)
17	ADD NOTES IN thermalequilibrium3;
18	'solver' name {QRSlv}
19	'QRSlv' iterationlimit {50}
20	'QRSlv' singtol {1e-10}
21	(* following are not implemented yet *)
22	'LSODE' minstep {0.01}
23	'LSODE' firststep {0.1}
24	'LSODE' duration {3000}
25	END NOTES;
26
27	MODEL thermalequilibrium3;
28	S[1..2] IS_A iapwssat;
29	m[1..2] IS_A mass;
30	h IS_A heat_transfer_coefficient;
31	A IS_A area;
32
33	p ALIASES S[1].p;
34	S[2].p = S[1].p;
35
36	Q IS_A energy_rate;
37	Q = hA(S[1].T - S[2].T); (* rate of heat transfer from 1 to 2 *)
38	m[1]*dhdt[1] = -Q;
39	m[2]*dhdt[2] = +Q;
40
41	dhdt[1..2] IS_A delta_specific_power;
42
43	t IS_A time;
44	METHODS
45	METHOD specify;
46	FIX h, A, m[1..2], S[1..2].h, p;
47	END specify;
48	METHOD values;
49	A := 1 {m^2};
50	h := 10 {W/m^2/K};
51
52	p := 1 {bar};
53
54	m[1] := 2 {kg};
55	S[1].h := 1000 {kJ/kg};
56	m[2] := 10 {kg};
57	S[2].h := 2000 {kJ/kg};
58	END values;
59	METHOD ode_init;
60	FOR i IN [1..2] DO
61	S[i].h.ode_id := i;
62	dhdt[i].ode_id := i;
63	S[i].h.ode_type := 1;
64	dhdt[i].ode_type := 2;
65	END FOR;
66
67	Q.obs_id := 2;
68	S[1].h.obs_id := 3;
69	S[2].h.obs_id := 4;
70
71	t.ode_type := -1;
72	t := 0 {s};
73	END ode_init;
74	METHOD on_load;
75	RUN reset;
76	RUN values;
77	EXTERNAL setup_solver(SELF);
78	EXTERNAL solve(SELF);
79	RUN ode_init;
80	END on_load;
81
82	END thermalequilibrium3;