Strategies for Minimising Railway Energy Consumption |
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Named Investigators: Prof Rod Smith (Imperial College London)
Researchers: Matthew Read (Imperial College London)
Industry Collaboration and Mentors: ATOC; National Express; Network Rail; Railway Forum
Background:
There is an increasing awareness within the railway sector that it faces real economic and environmental challenges, coupled with new technology opportunities. Rising energy/fuel costs (particularly oil) and increasingly stringent environmental regulations are already beginning to take effect and this process will continue. This has particular significance in the UK where there is a heavy reliance upon diesel (fossil fuelled) traction (some 50% of total train miles in comparison with 10-15% on other major European railways). In addition the long lifecycle of rolling stock (from procurement to retirement) and infrastructure means that the rail sector is often unable to capitalise on immature technology which could well reach full market maturity during the life cycle of the assets. Rail therefore may lose competitiveness relative to other modes over time. The key to future sustainability therefore lies in the development of technological solutions and energy stewardship options that deliver improved environmental performance at reduced cost.
Brief Summary of Research Methods:
The project has focused primarily on traction energy use and technologies to reduce this. Therefore computer simulation of rail vehicles in order to calculate traction energy consumption using detailed power-train component models is the major basis of this research. This will be used to assess current performance and the potential for energy reduction of new technologies. In parallel analysis of available operational data will be conducted, allowing validation of computational methods. Small-scale experimental testing of power-train configurations is also proposed to provide further validation. The context of this in the overall well to wheel performance will be studied through research of the literature.
Original Project Scope and Objectives:
To understand and model the energy flow within the railway industry from well to wheel, and to develop cost effective strategies to optimise the use of energy within the rail industry.
Work Done:
A computer simulation tool has been developed in order to facilitate this research, this tool will continue to be developed and refined. At this point the tool has been used to conduct fundamental analysis of train driving styles and techniques, and of the power-train design and control strategy. Significant energy effects were predicted by varying driving technique, and also relatively simple design changes such as selective use of distributed traction motors and diesel engines have been studied. Evaluation of new traction technologies such as on-board storage hybrids has been commenced.
The design of a laboratory rig to investigate new technologies and provide model validation has been started. Substantial background research of the literature into the well to wheel context of the project has been completed.
Work Remaining:
The development of the computer simulation tool will include a train driver model based on current operating practice. This will be achieved through analysis of recorded journey data, and will focus on identifying the conditions under which powering, braking and coasting are initiated. This will be used to define a base level of performance for current rail vehicles, and to assess what energy savings may be achieved through improved driver training.
The evaluation of potential new traction technologies will focus on kinetic energy storage systems consisting of flywheels and continuously variable transmissions; these being identified as potentially efficient and cost effective options for enabling regenerative braking on diesel powered rail vehicles (particularly those with hydrodynamic transmissions). Comparison of a range of power-train components and configurations will be investigated using detailed computational modelling, and experimental testing will be carried out to prove some power-train concepts and validate simulation work. Performance of the full scale simulated vehicles will be compared with current diesel-electric and diesel-hydrodynamic vehicles.
Outputs: