Experimental densities, vapor pressures, and critical point, and a fundamental equation of state for dimethyl ether

ThermoData Engine (TDE): Software Implementation of the Dynamic Data Evaluation Concept. 2. Equations of State on Demand and Dynamic Updates over the Web

“…Often, the properties of a pure fluid are represented by a variety of equations; for example, the vapor pressure can be represented by a Wagner type equation and the liquid density with a Tait type equation (cf. ref 20). Multiple equations may be used to span wide ranges of density, where one equation is often used for the liquid, one for the vapor, and possibly a third for supercritical conditions.…”

Estimation of thermophysical properties of dimethyl ether as a commercial refrigerant based on artificial neural networks

“…With these equations, it is possible to correlate the PqT data over the whole of liquid state, up to nearly the critical point within the experimental uncertainties. The product of equations for the pressure range between 0.88 and 40 MPa (206 data points) had the absolute average deviation about 0.04% (Ihmels & Lemmon, 2007) that is an acceptable accuracy. Nonetheless, in the experimental section of implicit research, dimethyl ether densities have been measured in 417 data points (sub-and supercritical conditions).…”

“…Therefore, PR EoS has been compared to the ANN results. By using the ANN and PR EoS, densities are calculated at temperatures from 273 to 523 K and pressure range, between 23 and 234 and compared to experimental data reported by Ihmels and Lemmon (2007). Note that this data set (22 data points) is not used to train the network and is unseen data.…”

“…In this model, the Tait equation was combined with a modified Rackett equation (Ihmels & Lemmon, 2007). With these equations, it is possible to correlate the PqT data over the whole of liquid state, up to nearly the critical point within the experimental uncertainties.…”

“…It is used as a starting material to produce dimethyl sulfate. In addition, it can be used for large-scale production of acetic acid, and it has found commercial use as a refrigerant (Ihmels & Lemmon, 2007). Recent investigations of clean alternative fuels have shown that dimethyl ether and its mixtures have excellent properties as diesel fuels and have a promising future as a replacement for fuels obtained from fossil reserves (Wu, Liu, Wang, & Pan, 2004b).…”