Contents - Index


User-Supplied Property Data

 

EES allows the user to add new property data to the existing data base.  An ASCII file containing the coefficients of the property data correlations must be prepared for each new fluid and placed in the USERLIB\mhe Property Files subdirectory.  Two types of data can be supplied: real fluid and ideal gas.  

 

Real Gas Formulation

EES uses the Martin-Hou (A.I.Ch.E. Journal, 1:142, 1955) and the Fundamental Equation of State (Reiner Tillner-Roth, "Fundamental Equations of State", Shaker, Verlag, Aachan, 1998) to represent the thermodynamic properties of real fluids.  Only the Martin-Hou representation can be used by the user to enter new data.  The file can have any legitimate DOS name with a .MHE filename extension.  An example file with comments is shown below.

 

UserFluid

58.1           {­molecular weight}

0              {­not used}

12.84149       {­a} Liquid density = a+b*Tz^(1/3)+c*Tz^(2/3)+d*Tz+e*Tz^(4/3)+f*sqrt(Tz)+g*(Tz)^2} 33.02582       {­b}    where Tz=(1-T/Tc) and Liquid Density[=]lbm/ft3

-2.53317       {­c}

-0.07982       {­d}

9.89109        {­e}

0              {­f}

0              {­g}

-6481.15338    {­a}  Vapor pressure fit: lnP=a/T+b+cT+d(1-T/Tc)^1.5+eT^2

15.31880       {­b}     where T[=]řR and P[=]psia

-0.0006874     {­c}

4.28739        {­d}

0              {­e}

0              {­not used}

0.184697       {­Gas constant in psia-ft3/lbm-R}

1.5259e-2      {­b}  Constants for Martin-Hou EOS/English_units

-20.589        {­A2}

9.6163e-3      {­B2}

-314.538       {­C2}

0.935527       {­A3}

-3.4550e-4     {­B3}

19.0974        {­C3}

-1.9478e-2     {­A4}

0              {­B4}

0              {­C4}

0              {­A5}

2.9368e-7      {­B5}

-5.1463e-3     {­C5}

0              {­A6}

0              {­B6}

0              {­C6}

5.475          {­Beta}

0              {­alpha}

0              {­C'}

-7.39053E-3    {­a}   Cv(0 pressure) = a + b T + c T^2 + d T^3 + e/T^2

6.4925e-4      {­b}           where T[=]R and Cv[=]Btu/lb-R

9.0466e-8      {­c}

-1.1273e-10    {­d}

5.2005e3       {­e}

124.19551      {­href offset}

0.0956305      {­sref offset}

550.6          {­Pc [=] psia}

765.3          {­Tc [=] R} 

0.07064        {­vc [=] ft3/lbm}

0              {­not used}

0              {­not used}

2              {­Viscosity correlation type: set to 2: do not change}

260            {­Lower limit of gas viscosity correlation in K}

535            {­Upper limit of gas viscosity correlation in K}

-3.790619e6    {­A}    GasViscosity*1E12=A+B*T+C*T^2+D*T^3 

5.42356586e4   {­B}    where T[=]K and GasViscosity[=]N-s/m2

-7.09216279e1  {­C}

5.33070354e-2  {­D}

115            {­Lower limit of liquid viscosity correlation in K}

235            {­Upper limit of liquid viscosity correlation in K}

2.79677345e3   {­A}   Liquid Viscosity*1E6=A+B*T+C*T^2+D*T^3

-2.05162697e1  {­B}    where T[=]K and Liquid Viscosity[=]N-s/m2

5.3698529e-2   {­C}

-4.88512807e-5 {­D}

2              {­Conductivity correlation type: set to 2: do not change}

250            {­Lower limit of gas conductivity correlation in K}

535            {­Upper limit of gas conductivity correlation in K}

7.5931e-3      {­A}   GasConductivity=A+B*T+C*T^2+D*T^3

-6.3846e-5     {­B}    where T[=]K and GasConductivity[=]W/m-K

3.95367e-7     {­C}

-2.9508e-10    {­D}

115            {­Lower limit of liquid conductivity correlation in K}

235            {­Upper limit of liquid conductivity correlation in K}

2.776919161e-1 {­A}   LiquidConductivity=A+B*T+C*T^2+D*T^3

-8.45278149e-4 {­B}    where T[=]K and LiquidConductivity[=]W/m-K

1.57860101e-6  {­C}

-1.8381151e-9  {­D}

0              {­not used: terminator}

 

Ideal Gas Formulation

The JANAF table ideal gas files must have a .IDG filename extension.  The .IDG file format allows several different types of correlations for the ideal gas specific heat, viscosity and thermal conductivity.  One form is consistent with the representations provided in the DIPPR data base.  

 

DIPPR Project 801 - Evaluated Process Design Data,

BYU-DIPPR Thermophysical

Properties Laboratory, Chemical Engineering Department, Brigham Young

University, Provo, Utah, USA(2001).

http://dippr.byu.edu/ 

 

An example .IDG file with comments is provided below.  

 

TestH2O

18.016         {­Molar mass of fluid

-1             {­Tn  If Tn>0, Tn is the reducing temperature used in the Cp equation; TN<0 indicates Cp equation type}

100            {­Lower temperature limit of Cp correlation in K}

2273           {­Upper temperature limit of Cp correlation in K}

3.3363E+04 0.0 {­a0, b0  if (Tn>0) then  Cp=sum(a[i]*(T/Tn)^b[i], i=0,9 in kJ/kgmole-K}

2.6790E+04 0.0 {­a1, b1  if (Tn=-1) then Cp=a1+a2*((a3/T)/sinh(a3/T))^2+a4*((a5/T)/sinh(a5/T))^2 in J/kgmole-K} 2.6105E+03 0.0 {­a2, b2}

8.8960E+03 0.0 {­a3, b3}

1.1690E+03 0.0 {­a4, b4}

0 0            {­a5, b5}

0 0            {­a6, b6}

0 0            {­a7, b7}

0 0            {­a8, b8}

0 0            {­a9, b9}

298.15         {­TRef in K}

100            {­Pref in kPa}

-2.41814E+05   {­hform - enthalpy of formation in kJ/kgmole at TRef}

1.88724E+02    {­s0 - Third law entropy in kJ/kgmole-K at Tref and PRef}

1              {­viscosity correlation type: 0=Polynomial form, 1=DIPPR form}

1              {­conductivity correlation type: 0=Polynomial, 1=DIPPR form}

273.15         {­Lower temperature limit of gas phase viscosity correlation in K}

1073.0         {­Upper temperature limit of gas phase viscosity correlation in K}

6.1839E-07     {­v0  if (Viscosity Type = 0) Viscosity = sum(v[i]*T^(i)) for i=0 to 5 in Pa/m^2}

6.7779E-01     {­v1} if (Viscosity Type = 1) Viscosity = v[0]*T^v[1] / (1 + v[2]/T + v[3]/T^2 in N-s/m^2) 

8.4723E+02     {­v2}

-7.3930E+04    {­v3}

0              {­v4}

0              {­v5}

200            {­Lower temperature limit of gas phase thermal conductivity correlation in K}

1000           {­Upper temperature limit of gas phase thermal conductivity correlation in K}

2.1606E-03     {­t0  if (Conductivity Type = 0)  Conductivity = sum(t[i]*T^(i)) for i=0 to 5 in W/m-K}

7.6839E-01     {­t1  if (Conductivity Type = 1)  Conductivity = t[0]*T^t[1] / (1 + t[2]/T + t[3]/T^2)  in W/m-K} 3.9405E+03     {­t2}

-4.4534E+05    {­t3}

0              {­t4}

0              {­t5}

647.096 22064.0 3.10559e-3  0.348  {­Tc [K], Pc [kPa], vc [m3/kg], acentric factor}

0              {­Terminator - set to 0}

 

 

Up to 100 additional fluids can be added in this manner.