Feasibility study for SOFC-GT hybrid locomotive power part II. System packaging and operating route simulation

Abstract

a b s t r a c tThis work presents the development of a dynamic SOFC-GT hybrid system model applied to a long-haul freight locomotive in operation. Given the expectations of the rail industry, the model is used to develop a preliminary analysis of the proposed system's operational capability on conventional diesel fuel as well as natural gas and hydrogen as potential fuels in the future. It is found that operation of the system on all three of these fuels is feasible with favorable efficiencies and reasonable dynamic response. The use of diesel fuel reformate in the SOFC presents a challenge to the electrochemistry, especially as it relates to control and optimization of the fuel utilization in the anode compartment. This is found to arise from the large amount of carbon monoxide in diesel reformate that is fed to the fuel cell, limiting the maximum fuel utilization possible. This presents an opportunity for further investigations into carbon monoxide electrochemical oxidation and/or system integration studies where the efficiency of the fuel reformer can be balanced against the needs of the SOFC.

Comparative analysis of SOFC–GT freight locomotive fueled by natural gas and diesel with onboard reformation

“…Prior investigations utilizing the FORTRAN-based simulation model of this study have discussed the full details of the model structure, methodology, physics, chemistry and electrochemistry included, numerical methods, and convergence criteria [24,25]. In the current study, these details are largely the same, but certain additions and alterations have been introduced in order to accommodate the integrated dynamic simulation of the reformer module and the effects that such integration has on performance and model structure.…”

“…Solutions of many of the states depicted in the two systems (denoted as TT1 through TT13) are described in [25]. In particular, the states surrounding the fuel cell, combustor, and turbo-machinery are described.…”

“…Each of these models, previously developed and described [24,25], were solved in the sequence shown in Fig. 4.…”

“…Other than this work and the two prior related feasibility analyses [24,25], assessment of SOFC technology for locomotives has only recently appeared in a pair of academic pursuits. In a study of a long-haul SOFC locomotive, Schroeder and Majumdar [26] concluded that such a system could feasibly be produced.…”

“…The current investigation builds upon the simplified system analyses developed in the two prior feasibility analyses [24,25]. In those works, a conceptual system design for an SOFC-gas turbine hybrid system was assessed based on its steady-state and in-service operational capability.…”