In this paper, a novel nodalized reduced order model (NROM) has been developed to analyze the linear stability in a heated channel using supercritical water (SCW) as a coolant. The presented reduced order model is developed based on the two-phase flow system approach. The model is much simplified, which reduced the requirement of computational efforts and resources. In the heated channel, the SCW’s density shows a dramatic downfall near the pseudo-critical temperature, based on which it has been divided into n number of nodes. The one-dimension partial differentiation conservation equations of energy, mass and momentum are used and have been linearized by a small perturbation applied on its steady-state solution. These PDEs are converted into the corresponding time-dependent, nonlinear ordinary differential equations (ODEs) by using weighted residual method applied under some appropriate assumptions and approximations. These sets of ODEs (n+1 equations) are then solved analytically by using a state space approach to capture the stability boundary (SB) in terms of trans-pseudo-critical phase change number (Ntpc), pseudo-subcooling number (Nspc) by applying a constant external pressure drop (ΔPtpc) condition across the channel. The NROM results are found to be in good agreement with the methodology and have been verified by numerical simulation. To extend this as a nonlinear stability analysis, the different types of the Hopf Bifurcation regime are also reported.
- Power Division
- Advanced Energy Systems Division
- Solar Energy Division
- Nuclear Engineering Division
Nodalized Reduced Ordered Model for Stability Analysis of Supercritical Fluid in Heated Channel
Singh, MP, Rahman, ME, & Singh, S. "Nodalized Reduced Ordered Model for Stability Analysis of Supercritical Fluid in Heated Channel." Proceedings of the ASME 2018 Power Conference collocated with the ASME 2018 12th International Conference on Energy Sustainability and the ASME 2018 Nuclear Forum. Volume 2: Heat Exchanger Technologies; Plant Performance; Thermal Hydraulics and Computational Fluid Dynamics; Water Management for Power Systems; Student Competition. Lake Buena Vista, Florida, USA. June 24–28, 2018. V002T10A005. ASME. https://doi.org/10.1115/POWER2018-7366
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