A Practical Recuperated Split Cycle Engine for Low Emissions and High Efficiency

The Recuperated Split Cycle Engine is a new type of ICE, offering a step change in efficiency and tailpipe emissions. It targets the heavy duty, long-haul sector (trucks, off-highway, rail, shipping), where electrification is most challenging, and distributed generation, where capacity is required to support rising electrification. The engine separates cold (induction, compression) and hot (combustion, expansion) parts of the cycle; waste exhaust heat is recovered between them via a recuperator, as in a recuperated gas turbine. Recent research presented at this conference [1] shows that the sonic airflows seen in the induction event give rise to extraordinary fuel mixing and clean, cool combustion, with potential for after-treated emission levels between SULEV and zero-impact (either unmeasurable or below ambient). Recuperation and thermal insulation of the hot cylinder (both feasible within the capability of common materials) also enable high thermal efficiency, with a flatter efficiency map than a conventional ICE. Combining the two attributes, and introducing sustainable fuels, places this readily manufactured, affordable technology on a par with battery-electric and fuel cell propulsion. Results from simulation to optimise the concept are described. A Ricardo WAVE model was built, with validation of key inputs such as valve breathing, heat transfer and burn-rates from relevant experimental research data. The model was used to develop the cycle around three concepts - a basic layout, “ThermoPower”, was shown to be capable of over 10% fuel saving; “Wet ThermoPower” uses water injection as a compression coolant for greater efficiency, while the ultimate “CryoPower” injects Liquid Nitrogen for quasi-isothermal compression and charge dilution. The optimisation process and practical details are described, especially the development of the critical recuperator, which is subjected to high pressure and temperature; management of its thermal expansion and manufacturing process have been optimised to minimise add-cost over a current ICE bill of materials.

• Record URL:
  • https://doi.org/10.4271/2019-24-0190
• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/issn/01487191
• Supplemental Notes:
  • Abstract reprinted with permission of SAE International.
• Authors:
  • Owen, Nicholas
  • Treccarichi, Fabrizio
  • Atkins, Andrew
  • Selvaraj, Anoop
  • Barnes, David
  • Besant, Tanzi
  • Morgan, Robert
• Conference:
  • 14th International Conference on Engines & Vehicles
  • Location: Capri Napoli, Italy
  • Date: 2019-9-15 to 2019-9-19
• Publication Date: 2019-9-9

Language

• English

Media Info

• Media Type: Digital/other
• Features: Figures; Photos; References; Tables;
• Serial:
  • SAE Technical Paper
  • Publisher: Society of Automotive Engineers (SAE)
  • ISSN: 0148-7191
  • EISSN: 2688-3627
  • Serial URL: http://papers.sae.org/

Subject/Index Terms

• TRT Terms: Emission control systems; Engine cycle; Engine cylinders; Exhaust gases; Fuel air mixtures; Internal combustion engines; Optimization; Simulation; Thermal efficiency
• Subject Areas: Energy; Environment; Highways; Vehicles and Equipment;

Filing Info

• Accession Number: 01722815
• Record Type: Publication
• Source Agency: SAE International
• Report/Paper Numbers: 2019-24-0190
• Files: TRIS, SAE
• Created Date: Nov 18 2019 5:15PM