fortran运行结果不合理，求大佬们的帮忙

sunjiyue · 发表于 2020-1-21 09:40:56

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01program enthalpy
02    implicit none
03!This program aim to calculate the enthalpy of h2s hydrate dissociation in the presence of water
04 
05 
06    double precision P,T,xh2s,n
07    double precision dPdT,H1,V,Hdiss,Hsolve
08 
09    print*,"please imput temperature (K)"
10    read*,T
11    print*,"please imput pressure (MPa)"
12    read*,P
13    print*,"please imput hydation number"
14    read*,n
15    print*,"please imput mole fraction of h2s in liquid"
16    read*,xh2s
17 
18    call dissenthalpy(Hdiss,T,dPdT,V)
19    call solveenthalpy(Hsolve,xh2s,n)
20 
21    H1=Hdiss+Hsolve
22 
23    print*,"H1=",H1
24    pause
25!    return
26    end
27 
28    subroutine Derivative(dPDT,T)
29    double precision dPdT,T,e(4)
30    data e/-436.1,4.6,-0.018,0.0000196/
31    dPdT=e(1)+e(2)*T+e(3)*T**2+e(4)*T**3    !MPa/K
32    print*,"dPdT=",dPdT
33    return
34    end
35 
36    subroutine Totalmolarvolume(V,Vliquid,Vgas,Vhydrate)    
37    double precision V,Vliquid,Vgas,Vhydrate,xh2s,n,parameter1,parameter2,density2,l(4)                 !density1,molecularweight2,V4,molecularweight,h(6) 
38    !data h/44.202,2544.564,-35.957,0.191,-4.488E-4,3.965E-7/
39    data l/21.90583,-0.21947,7.33695E-4,-8.18347E-7/
40    !calculating the molar volume change of solution
41    parameter1=0.0000045
42    parameter2=0.000018
43    Vliquid=xh2s*parameter1+parameter2   !m3/mol
44 
45    !calculating the molar volume change of hydrate
46   ! density1=1050  !kg/m3   !this value is guess
47   ! molecularweight2=0.1461 !kg/mol
48    Vhydrate=1.391E-4    !m3/mol, Vhydrate=molecularweight/density1
49 
50    !calculating the molar volume change of vapor
51    !density2=h(1)+h(2)*T+h(3)*T**2+h(4)*T**3+h(5)*T**4+h(6)*T**5   !kg/m3
52    !molecularweight=0.034 !kg/mol
53   ! Vgas=molecularweight/density2   !m3/mol
54     Vgas=l(1)+l(2)*T+l(3)*T**2+l(4)*T**3
55 
56    !calculating the total molar volume
57    V=(1-(n*xh2s)/(1-xh2s))*Vgas+n*Vliquid-Vhydrate   !m3/mol
58 
59    print*,"Vliquid=",Vliquid
60    print*,"Vhydrate=",Vhydrate
61    print*,"Vgas=",Vgas
62    print*,"V=",V
63    return
64    end
65 
66    subroutine dissenthalpy(Hdiss,T,dPdT,V)
67    double precision Hdiss,T,dPdT,V,Vliquid,Vgas,Vhydrate
68    call Derivative(dPDT,T)
69    call Totalmolarvolume(V,Vliquid,Vgas,Vhydrate)
70    Hdiss=1000000.0*dPdT*T*V
71    print*,"Hdiss=",Hdiss
72    return
73    end
74 
75    subroutine solveenthalpy(Hsolve,xh2s,n)
76    double precision Hsolve,xh2s,n
77    Hsolve=17960.0*n*xh2s/(1-xh2s)   !J/mol
78    print*,"Hsolve=",Hsolve
79    return
80    end

按照上面的运行结果，我输入T=274.15 K, P=0.118 MPa，n=6.2, xh2s=0.004的情况下，输出结果为：
dPdT=  -124.007293931873
Vliquid= -4.165183558045402E+056
Vhydrate=  1.390999968862161E-004
Vgas=  1.013072811542869E+018
V=  3.855278546349224E+118
Hdiss= -1.310663612078491E+129
Hsolve= 447.196787148594
H1= -1.310663612078491E+129

上述高亮部分结果不对，为什么会出现10的129次方呢，可我又不知道为什么，本人小白一枚，求各位大佬支招