VSR

Equations

$Local On

$INCLUDE TQ_Fct.txt

Program Verificarea unui Subracitor

procedure CMM (wc1, wc2 : wcmin, wcmax) (1)

If (wc1< wc2) then (2)

wcmin = wc1; wcmax = wc2; (3)

else (4)

wcmin = wc2; wcmax = wc1; (5)

endif (6)

end (7)

function GETEPS(SC$) (8)

1

$Common NTC_max,wc_min,wc_max

If (SC$ = ‘CC’ ) then (9)

GETEPS=1− exp (−NTCmax · (1− wcmin/wcmax))

1− wcmin/wcmax · exp (−NTCmax · (1− wcmin/wcmax)); (10)

else (11)

GETEPS=1− exp (−NTCmax · (1 + wcmin/wcmax))

1 + wcmin/wcmax; (12)

endif (13)

end (14)

Procedura pentru determinarea temperaturilor curente ale fluidelor intr-un punct Sx al suprafetei

procedure GetTx (SC$, Nrpct : Sx,0..Nr,pct, t1,x,0..Nr,pct, ∆tx,0..Nr,pct, t2,x,0..Nr,pct) (15)

$Common t_1_i,t_2_i,t_1_e,t_2_e,S_e,NTC_max,wc_min,wc_max,Eps,wc_1,wc_2,k_Se

If (SC$ = ‘EC’ ) then (16)

Echicurent

µe = 1/wcmin + 1/wcmax (17)

∆ti = t1,i − t2,i (18)

duplicate i = 0, Nrpct (19)

Sx,i = i · Se/Nrpct (20)

ρx,i =1− exp

(−µe · kSe ·

∣∣∣0.001 kWW

∣∣∣ · Sx,i)1 + wc1/wc2

(21)

∆tx,i = (t1,i − t2,i) · exp(−µe · kSe ·

∣∣∣∣∣0.001 kWW∣∣∣∣∣ · Sx,i

)(22)

t1,x,i = t1,i − (t1,i − t2,i) · ρx,i (23)

t2,x,i = t1,x,i −∆tx,i (24)

end (25)

else (26)

2

Contracurent

µc = 1/wc1 − 1/wc2 (27)

∆ti = t1,i − t2,e (28)

Fic =1− exp

(−µc · kSe ·

∣∣∣0.001 kWW

∣∣∣ · Se)1− wc1/wc2 · exp

(−µc · kSe ·

∣∣∣0.001 kWW

∣∣∣ · Se) (29)duplicate i = 0, Nrpct (30)

Sx,i = i · Se/Nrpct (31)

∆tx,i = (t1,i − t2,e) · exp(−µc · kSe ·

∣∣∣∣∣0.001 kWW∣∣∣∣∣ · Sx,i

)(32)

t1,x,i = t1,i − (t1,i − t2,i) ·1− Fic · wc1/wc2

1− wc1/wc2·(

1− exp(−µc · kSe ·

∣∣∣∣∣0.001 kWW∣∣∣∣∣ · Sx,i

))(33)

t2,x,i = t1,x,i −∆tx,i (34)

end (35)

endif (36)

end (37)

Marimi de intrare - vezi si fereastra Diagram

Ag$2 = ‘Water’ (38)

T$ = ‘Carbonsteel’ (39)

$IFNOT DiagramWindow

Ag1$ = ‘Ammonia’ (40)

SC$ = ‘CC’ (41)

Si = 3[m2]

(42)

ṁ1 = .5 [kg/s] ; ṁ2 = .5 [kg/s] (43)

t1,i = 30 [C] ; t2,i = 20 [C] (44)

De,i = 32 [mm] ·∣∣∣∣0.001 mmm

∣∣∣∣; deltat,i = 3 [mm] · ∣∣∣∣0.001 mmm∣∣∣∣ (45)

De,e = 57 [mm] ·∣∣∣∣0.001 mmm

∣∣∣∣; deltat,e = 3 [mm] · ∣∣∣∣0.001 mmm∣∣∣∣ (46)

Ru = 0.06× 10−3/0.12 m2-K/W (47)

Rp = 0.75× 10−3/1.5 m2-K/W (48)

3

$EndIF

Di,i = De,i − 2 · δt,i; Di,e = De,e − 2 · δt,e (49)

Calculul Termic

λT = k (T$, 30 [C]) (50)

call Props

(Ag$1, t1,i, Po# ·

∣∣∣∣∣0.01 barkPa∣∣∣∣∣, 0 : ρ1, cp,1, λ1, η1, Pr1

)(51)

call Props

(Ag$2, t2,i, Po# ·

∣∣∣∣∣0.01 barkPa∣∣∣∣∣, 0 : ρ2, cp,2, λ2, η2, Pr2

)(52)

A1 = π ·D2i,e −D2e,i

4; A2 = π ·D2i,i/4; (53)

w1 =ṁ1

ρ1 · A1; w2 = ṁ2/ (ρ2 · A2) ; (54)

Re1 = ρ1 · w1 ·Di,e −De,i

η1; Re2 = ρ2 · w2 ·Di,i/η2; (55)

α1 = αCF,i (λ1, Pr1, Re1) ; Alpha2 = αCF,t (Di,i, λ2, Pr2, Re2) (56)

kSe =1

1/α1 + Ru + (De,i −Di,i) / (2 · λT ) · (2 ·De,i) / (De,i + Di,i) + (1/α2 + Rp) ·De,i/Di,i; (57)

wc1 = ṁ1 · cp,1; wc2 = ṁ2 · cp,2; (58)

call Cmm (wc1, wc2 : wcmin, wcmax) (59)

NTCmax = kSe ·∣∣∣∣∣0.001 kWW

∣∣∣∣∣ · Se/wcmin; (60)Eps= GETEPS(SC$) (61)

Calculul sarciii termice si a temperaturilor de iesire ale fluidelor

Q̇ = Eps· wcmin · (t1,i − t2,i) ; (62)

t1,e = t1,i − Q̇/wc1; t2,e = t2,i + Q̇/wc2; (63)

Trasarea variatiei temperaturilor fluidelor in lungul suprafetei

Nrpct = 10 (64)

call GetTx (SC$, Nrpct : Sx,0..Nr,pct, t1,x,0..Nr,pct, ∆tx,0..Nr,pct, t2,x,0..Nr,pct) (65)

$TABSTOPS 1 2 3 6 cm

Solution

Variables in Main program

4

α1 = 6339 [W/m2-C] α2 = 4281 [W/m2-C] A1 = 8.294× 10−4 [m2]

A2 = 8.042× 10−4 [m2] δt,e = 0.0035 [m] δt,i = 0.003 [m]De,e = 0.057 [m] De,i = 0.038 [m] Di,e = 0.05 [m]Di,i = 0.032 [m] Eps= 0.3064 kSe = 631.8 [W/m2-C]λT = 60.38 [W/m-K] ṁ1 = 0.7 [kg/s] ṁ2 = 1 [kg/s]

Nrpct = 10 NTCmax = 0.4469 Q̇ = 12.47 [kW]

Re1 = 76089 Re2 = 39704 Rp = 5.000× 10−4 [m2-K/W]Ru = 5.000× 10−4 [m2-K/W] SC$ = ‘EC’ Se = 2.4 [m2]T$ = ‘Carbonsteel’ t1,e = 28.32 [C] t1,i = 32 [C]

t2,e = 22.98 [C] t2,i = 20 [C] wc1 = 3.393 [kW/K]

wc2 = 4.183 [kW/K] wcmax = 4.183 [kW/K] wcmin = 3.393 [kW/K]w1 = 1.425 [m/s] w2 = 1.246 [m/s]

Variables in Function AlphaCFi

αCF,i = 6339[W/m2·C

]λ = 0.4649 [W/m-C] Pr = 1.388

Re= 76089 DI,E = 0.05 [m] DE,I = 0.038 [m]Regim$ = ‘Regim turbulent’ Nu# = 163.6 DI,E = 0.05 [m]DE,I = 0.038 [m]

Variables in Function AlphaCFt

αCF,t = 4281[W/m2·C

]dech = 0.032 [m] λ = 0.586 [W/m-C]

Pr = 7.154 Re= 39704 Regim$ = ‘Regim turbulent’Nu# = 233.7 epstr = 1

Arrays

Row Ag$i ρi cp,i λi ηi Pri Sx,i t1,x,i ∆tx,i t2,x,i[kg/m3] [kJ/kg-C] [W/m-C] [Pa-s] [m2] [C] [C] [C]

0 0 32 12 201 Ammonia 592.1 4.847 0.465 1.33E-4 1.388 0.24 31.48 11.07 20.422 Water 998.2 4.183 0.586 1.00E-3 7.154 0.48 31.01 10.21 20.83 0.72 30.57 9.413 21.164 0.96 30.17 8.681 21.495 1.2 29.79 8.006 21.796 1.44 29.45 7.384 22.077 1.68 29.13 6.81 22.328 1.92 28.84 6.28 22.569 2.16 28.57 5.792 22.7810 2.4 28.32 5.342 22.98

5

t-S

6