ECONAMIQ: Flexible over-expansion with cylinder deactivation can reduce ICE fuel consumption by up to 20%
Dutch start-up ECONAMIQ is developing a novel engine technology which saves up to 20% in fuel consumption. The “ECONAMIQ principle” uses flexible over-expansion in combination with cylinder deactivation technology to increase performance and efficiency without significantly changing the engine layout or architecture.
By over-expanding into adjacent de-activated cylinders, ECONAMIQ creates an additional power stroke within the existing engine architecture, with a significant thermal efficiency increase and cost savings as a result.
Top: P-V diagram schematic including the ECONAMIQ over-expansion method. The residual pressure of at the end of the power stroke is used in an extra low-pressure stroke of the non-burning cylinders. Bottom: Overview of the basic approach. Source: de Jong (2019), ECONAMIQ.
The new ECONAMIQ technology builds on existing concepts such as cylinder deactivation and variable valve timing with a unique patented combination of routing gasses for increased system efficiency.
The company presented its first results at the annual ASME ICEF (Internal Combustion Engine Fall) conference in Chicago. ECONAMIQ expects the technology to be implemented in several vehicles in the upcoming years.
An adaption of cylinder de-activation technique called ECONAMIQ over-expansion can be applied to engines to improve fuel efficiency. Using the pressure from the exhaust gas from the active cylinders, the ‘idle’ cylinders could be expanded to extract more work out of the engine during partial load operation. Using the virtual simulation environment GT-Power, this cycle is applied to a 4-cylinder SI engine.
This engine model is simulated for a part-load operation point and compared with a standard 4-cylinder engine model and 4-cylinder engine model equipped with cylinder deactivation. From these simulations various variables for engine operation (valve timing etc.) are optimized to further reduce fuel consumption of the engine. A final brake specific fuel consumption reduction of over 10% is achieved using the overexpansion cycle, while improving engine performance on two burning cylinders over 10% as well.
With this improvement it is shown that the over-expansion cycle has a significant benefit compared to a standard ICE and cylinder deactivation techniques. These simulations are being validated on an engine test dyno using a natural aspirated ICE.—de Jong (2019)
By utilizing the proven architecture of existing combustion engines, our technology can be integrated in engines with 4 or 8 cylinders relatively easily, as well as (range extender) hybrid electric vehicles. We therefore offer an attractive and industry friendly solution to OEMs for them to comply with increasingly challenging emission regulations and standards.—Arjen de Jong, PhD, Chief Technology Officer of ECONAMIQ.
Hybrid electric vehicles could especially benefit from this new technology, since the rapid engine warm up and high efficiency cycle that ECONAMIQ offers uses less fuel during power-assisted operation or battery charging.
ECONAMIQ provides greater savings potential than the popular downsizing of internal combustion engines, while the benefits of a larger displacement is preserved.
The internal exchange of flue gasses according to the ECONAMIQ principle ensures that the engine reaches operating temperature faster. In addition, engine vibrations are reduced during cylinder deactivation.
Visualization of the over-expansion modification.
The paper presented at ICEF 2019 reveals the outcome of a simulation and validation study confirming the viability of the technology using a unique modular test setup approach.
Indicated fuel consumption vs engine indicated power. Baseline engine in blue, CDA (cylinder deactivation) in orange, ECONAMIQ in green. de Jong (2019)
Next steps in the development include further optimization of the channel routing, shape and a dynamic test bench setup planned for 2020.
ECONAMIQ focuses on applying unconventional solutions on proven technologies. Its current focus is geared towards the vibrant and rapidly changing transportation sector with a strong focus on energy efficiency and cost reduction.
ECONAMIQ is headquartered in Utrecht, The Netherlands with subsidiaries in New York (NY) and San Jose (CA).
US20190153912A1: Combustion engine
Arjen de Jong (2019) “Novel Engine Cycle Enabling Partial Load Fuel Efficiency Beyond Full Load Conditions” ASME ICEF 2019 ICEF2019-7172