Systems Joule-Thomson coefficients

Equation (11.6) is quite general and should apply to any gas/ for its derivation is based entirely on the first la>y of thermodynamics without assuming any specific properties of the system. However, for an ideal gas, (dE/dV)r is zero, as seen earlier, and since PV = /2T, it follows that td PV)/dP ]T is also zero hence, since Cp is finite, it is seen from equation (11.6) that for an ideal gas mj.t. must be zero.f The Joule-Thomson coefficient of an ideal gas should thus be zero, so that there should be no change of temperature when such a gas e.xpands through a throttle. J... 

With the help of the binary parameters kn or g -model parameters now the phase equilibrium behavior, densities, enthalpies, Joule-Thomson coefficients, and so on, for binary, ternary and multicomponent systems can be calculated. For the calculation of the VLE behavior the procedure is demonstrated in the following example for the binary system nitrogen-methane using classical mixing rules. The same procedure can be applied to calculate the VLE behavior of multicomponent systems and with g -mixing rules as well. 

AIST can calculate the values of density, compressibility, enthalpy, entropy, isochoric and isobaric heat capacity, speed of sound, adiabatic Joule-Thomson coefficient, thermal pressure coefficient, samrated vapor pressure, enthalpy of vaporization, heat capacities on the saturation and solidification lines, viscosity and thermal conductivity. Values of properties can be determined at temperatures from the triple point up to 1500 K and pressures up to 100 MPa. The system generates the following databases with appropriate algorithms and programs for their calculation ... 

Most practical refrigeration and liquefaction systems obtain a reduction in temperature with the aid of an expansion valve (Joule-Thomson valve), an expansion engine, or a combination of the two devices. In the case of the expansion valve, the flow within the valve is irreversible as well as non-isenthalpic. However, the inlet and outlet conditions have the same enthalpy. The change in temperature of a fluid obtained with an isenthalpic change in pressure is represented by the Joule-Thomson (IT) coefficient, defined as... 

---