Thermodynamic steam data are traditionally presented in tables. However, there a

Question

Thermodynamic steam data are traditionally presented in tables. However, there are empirical equations relating saturation temperature, pressure, enthalpy, etc. One of these equations is:

Tsat = 8576.65/(15.47538 - ln(P_sat)) - 459.216 - 0.023719P_sat + (0.84219e-4)P_sat^2 - (0.70854e-7)P_sat^3 Note that 0.84219e-4 = 0.84219 x 10-4.
Make a table showing Temperature as a function of pressure for Psat from 20 to 600 psia every 20 psi, and another table showing pressure as a function of temperature from 150 degrees to 350 degrees every 20 degrees. Note that there is not an analytical solution to pressure as a function of temperature, so you must use the solver of your choice to calculate pressure. This does not have to be a function; you may use a script.
Present a graph making use of both data sets showing Tsat as a function of P_sat.

Explanation / Answer

function matrix = steam1(Psat)

clc

format short

for k = 1:length(Psat)

disp([num2str(k),')Psat=',num2str(Psat(k)),':'])

% Saturation temperature, F

matrix(k,1) = 8576.65/(15.47538 - log(Psat(k))) - 459.216 - 0.023719*Psat(k)...

            + (0.84219e-4)*Psat(k)^2 - (0.70854e-7)*Psat(k)^3;

disp(['Tsat=',num2str(matrix(k,1))])

% Liquid specific volume, ft3

matrix(k,2) = 0.01655 + (0.150326e-4)*Psat(k) - (0.40488e-7)*Psat(k)^2 ...

            + (0.665584e-10)*Psat(k)^3 - (0.4053e-13)*Psat(k)^4;

disp(['VLiq=',num2str(matrix(k,2))])

% Vapor specific volume, ft3

matrix(k,3) = 430.8419/(Psat(k) + 1.66) + 0.2031 - (0.000258)*Psat(k);

disp(['VVap=',num2str(matrix(k,3))])

% Liquid specific enthalpy, BTU

matrix(k,4) = 6473.878/(14.01875 - log(Psat(k))) - 391.6036 + (0.022915)*Psat(k);

disp(['HLiq=',num2str(matrix(k,4))])

% Vapor specific enthalpy, BTU

matrix(k,5) = 1142.342 + (0.76833)*Psat(k) - (0.004194)*Psat(k)^2 ...

     + (0.11642e-4)*Psat(k)^3 - (0.157e-7)*Psat(k)^4 + (0.8086e-11)*Psat(k)^5;

disp(['HVap=',num2str(matrix(k,5))])

end

1)Psat=40:

Tsat=267.6327

VLiq=0.017091

VVap=10.5346

HLiq=236.0273

HVap=1167.0705

2)Psat=60:

Tsat=293.2401

VLiq=0.01732

VVap=7.175

HLiq=262.0903

HVap=1175.6609

3)Psat=80:

Tsat=312.5233

VLiq=0.017526

VVap=5.4585

HLiq=282.0221

HVap=1182.3109

4)Psat=100:

Tsat=328.1884

VLiq=0.017711

VVap=4.4154

HLiq=298.4048

HVap=1187.3879

5)Psat=120:

Tsat=341.4925

VLiq=0.017877

VVap=3.7135

HLiq=312.4458

HVap=1191.211

6)Psat=140:

Tsat=353.1273

VLiq=0.018028

VVap=3.2084

HLiq=324.8139

HVap=1194.055

7)Psat=160:

Tsat=363.5163

VLiq=0.018165

VVap=2.8269

HLiq=335.9207

HVap=1196.1528

8)Psat=180:

Tsat=372.9379

VLiq=0.01829

VVap=2.5284

HLiq=346.0391

HVap=1197.6986

9)Psat=200:

Tsat=381.5853

VLiq=0.018405

VVap=2.288

HLiq=355.3598

HVap=1198.8515

ans =

  1.0e+003 *

    0.2676    0.0000    0.0105    0.2360    1.1671

    0.2932    0.0000    0.0072    0.2621    1.1757

    0.3125    0.0000    0.0055    0.2820    1.1823

    0.3282    0.0000    0.0044    0.2984    1.1874

    0.3415    0.0000    0.0037    0.3124    1.1912

    0.3531    0.0000    0.0032    0.3248    1.1941

    0.3635    0.0000    0.0028    0.3359    1.1962

    0.3729    0.0000    0.0025    0.3460    1.1977

    0.3816    0.0000    0.0023    0.3554    1.1989

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