%0 Journal Article %1 noauthororeditor %A Mirl, Nico %A Doil, Maik %A Spindler, Klaus %A Stergiaropoulos, Konstantinos %D 2020 %J Fluid Phase Equilibria %K 2020 HRT IGTE WuKT klausspindler konstantinosstergiaropoulos maikdoil myown nicomirl %R 10.1016/j.fluid.2020.112748 %T Comparison of ammonia/water equations of state under operating conditions of absorption systems %U https://www.sciencedirect.com/science/article/abs/pii/S0378381220302958 %X In this study, three different equations of state (EoS) for the ammonia/water mixture are compared with experimental data in order to find the EoS which best reproduces the measured data in the temperature range -30 °C≤ϑ≤200 °C and pressure range 1 bar≤p≤30 bar for absorption systems; the deviations among each other are to be pointed out. It is shown that the EoS of Tillner-Roth and Friend 1 shows the best match with the measured data in the considered temperature and pressure range. The EoS of Ibrahim and Klein 2, however, has the highest overall deviation to the investigated data. Subsequently, the absorber and desorber are assessed for an operating point obtained from 3 by using the different EoS to identify their influence on the component assessment. It is shown that the degassing range resulting from the measured density varies in this example by up to 4.5 % only due to the EoS used. Thereafter, a single-stage model for absorption chillers is created using the two most frequently used EoS. It can be stated that the calculated efficiency (COP) of the absorption chiller deviates up to ΔCOP=0.011 only because of the chosen EoS. Furthermore, due to the lower calculated excess enthalpy by the EoS of 2, the calculated COP will always be higher than that for a process simulation using the more accurate EoS of 1.

@article{noauthororeditor, abstract = {In this study, three different equations of state (EoS) for the ammonia/water mixture are compared with experimental data in order to find the EoS which best reproduces the measured data in the temperature range -30 °C≤ϑ≤200 °C and pressure range 1 bar≤p≤30 bar for absorption systems; the deviations among each other are to be pointed out. It is shown that the EoS of Tillner-Roth and Friend [1] shows the best match with the measured data in the considered temperature and pressure range. The EoS of Ibrahim and Klein [2], however, has the highest overall deviation to the investigated data. Subsequently, the absorber and desorber are assessed for an operating point obtained from [3] by using the different EoS to identify their influence on the component assessment. It is shown that the degassing range resulting from the measured density varies in this example by up to 4.5 % only due to the EoS used. Thereafter, a single-stage model for absorption chillers is created using the two most frequently used EoS. It can be stated that the calculated efficiency (COP) of the absorption chiller deviates up to ΔCOP=0.011 only because of the chosen EoS. Furthermore, due to the lower calculated excess enthalpy by the EoS of [2], the calculated COP will always be higher than that for a process simulation using the more accurate EoS of [1].}, added-at = {2020-08-12T16:54:39.000+0200}, author = {Mirl, Nico and Doil, Maik and Spindler, Klaus and Stergiaropoulos, Konstantinos}, biburl = {https://puma.ub.uni-stuttgart.de/bibtex/2c0b790073ebf89e6e094f51148f70188/nnicomirl}, doi = {10.1016/j.fluid.2020.112748}, interhash = {d6ac77abdac41b90a53202b55131cae5}, intrahash = {c0b790073ebf89e6e094f51148f70188}, journal = {Fluid Phase Equilibria}, keywords = {2020 HRT IGTE WuKT klausspindler konstantinosstergiaropoulos maikdoil myown nicomirl}, language = {english}, timestamp = {2020-08-12T14:54:39.000+0200}, title = {Comparison of ammonia/water equations of state under operating conditions of absorption systems}, url = {https://www.sciencedirect.com/science/article/abs/pii/S0378381220302958}, year = 2020 }