There is a discontinuity in the tabulated thermodynamic properties as the fluid is going across the critical point. In this paper, utilizing regularization techniques, correlations are established to continuously determine fluid properties during the transition through the critical point and into the supercritical region.
An augmented model for the dense phase is proposed by integrating our derived correlations into the conservation equations. The implementation of the augmented model is presented for a pipe network carrying ethane. The performance improvements that the proposed correlations when used in the augmented model can offer to CPM-based leak detection algorithms are discussed in detail.
A novel equation describing the limit behavior of the adiabatic heat index at the supercritical point is introduced, resulting in an updated correlation for maximum flow rate at choked conditions. The values from a certain hole size are obtained theoretically from the presented equations for a case study of NGL and condensate transmission pipeline rupture incident. An attempt is made to improve the sensitivity of leak detection systems, which is the minimum detectable hole sizes, with and without the regularized correlations presented in this paper. The minimum theoretical sizes of detection for a given model are estimated.