A Moving Boundary Modeling Approach for Heat Exchangers with Binary Mixtures. (September 2017)

• Record Type: Journal Article
• Authors: Kim, Donghun; Ziviani, Davide; Braun, James E.; Groll, Eckhard A.
• Is Part Of: Energy procedia. Volume 129(2017)
• Page Start: 466
• Page End: 473
• Publication Date: 2017-09
• Subjects: ORC -- Moving boundary method -- Water-Ethylene Glycol mixture; Power resources -- Congresses; Power resources -- Periodicals; Power resources; Conference proceedings; Periodicals; 333.7905
• DOI: 10.1016/j.egypro.2017.09.161
• Languages: English
• ISSNs: 1876-6102

Abstract

Abstract: In this paper, a modeling approach for a heat exchanger that uses a binary mixture is presented. A moving boundary method assuming a linear spatial distribution of enthalpy could result in a considerable steady state prediction error, due to the temperature glide of a binary mixture. Motivated from this, a more accurate moving boundary method that incorporates analytic enthalpy distributions is presented. The enthalpy profiles are derived by defining a specific heat capacity at each thermodynamic phase of a binary mixture and by solving crossflow heat transfer equations. The proposed approach results in accurate predictions compared with those of a detailed model using the Finite Volume Method (FVM). The corresponding computation time is two to three times slower than that of a conventional moving boundary approach, but the approach is still computationally advantageous compared with the FVM model.