【作者】

Adam Gurr

【摘要】

该论文已在赫尔辛基举行的第28届CIMAC世界大会上发表，论文的版权归CIMAC所有。 In the industrial segment reciprocating internal combustion engines are the prime source of power for power plants up to 50MW and more, for ship propulsion and auxiliary power, and for off-highway and many rail applications. Engines are commonly operated at high output for extended periods and the quantity and cost of fuel consumed is high, approaching 2 million litres of diesel equivalent per year for each MW of power. The through life fuel cost may easily exceed 100 times the engine capital cost and therefore engine efficiency is a prime factor in selecting and operating a large engine; efficiency now exceeds 50% for medium speed 4 stroke engines and approaches 55% for low speed 2 stroke engines. Engine efficiency continues to improve incrementally year on year through technical advancement in combustion, fuel injection, gas exchange, control and base engine design. However, a step change in reciprocating engine efficiency may be achieved through the implementation of alternative heat cycles, giving a significant opportunity to reduce the through life cost and environmental impact of energy. This paper addresses the use of split cycle high and medium speed engines for power generation to achieve efficiencies of 60% from units of 1 – 30 MW mechanical output. The split cycle engine separates the compression cycle from the combustion and expansion cycles which in addition to allowing each cylinder to be optimised, enables waste heat from the exhaust gas to be captured and transferred to the compressed intake air in a highly effective manner, as the charge air moves between the two cylinders. Initially a technology roadmap is set out to show current and future directions in efficiency and the positioning of split cycle technology amongst competitive technologies. Prior work by Ricardo is described for the evaluation and development of split cycle for industrial engine applications, referencing fundamental thermodynamic analyses and the identification of primary challenges in implementation to hardware. Through work between 1992 and 2002 the IsoEngine project developed a 3MW split cycle demonstrator for the stationary power market. Subsequent work focussed on enhancement of the compression process, and recently the cycle has been modelled by two different methods, by three individual organisations. All six independent models are converging on this common outcome. The current development is focussed to further enhance the heat exchange and combustion processes, utilising test work on a heavy duty diesel based combustor/expander single cylinder engine to correlate representative simulations. Engine testing activities through 2015 have been assessing the ability of mature technology, from this industry and others, to transfer the waste heat to the charge air and to achieve stable combustion in the combustor/expander cylinder. The development activity will identify optimum hardware configuration for implementation to a multi-cylinder engine with minimum change to existing engine architecture. Finally, considering high and medium speed engine efficiencies similar to those of large scale combined cycle plants and the associated capital and operating costs, a business case is developed to validate the feasibility of the split cycle engine as a future product for the power generation market. The paper will demonstrate the potential for split cycle technologies to deliver increased growth for reciprocating engines, delivering power systems with increased flexibility, full load efficiency levels that exceed that of combined cycle gas turbine plants with lower capital investment in combination with the inherent plant flexibility and part load efficiency offered by larger scale reciprocating power plants.

【会议名称】

第28届CIMAC会议

【会议地点】

芬兰 赫尔辛基

【下载次数】

2

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