Achates Power secures fifth OEM contract for opposed-piston 2-stroke CI engines; 3-cylinder configurations under test

9 December 2014

Achates Power, Inc., the developer of a family of efficient compression-ignition opposed-piston two-stroke (OP2S) engines (earlier post) has secured another contract with a leading global OEM. With this contract, the company has five concurrent customers the contracts for which encompass five different engine applications: passenger vehicle, light commercial vehicle, heavy commercial vehicle, military and marine/stationary power.

Achates Power’s engine allows OEMs to achieve the most stringent current and future fuel efficiency and emissions standards—including EPA 2010, Euro 6 and Tier 3/LEV 3—without additional cost or complexity. During 2014, Achates Power’s annual revenue has increased by more than 300%. The company has customers located in the US, Japan, Europe, China and India and its current engine programs range from 45 hp to more than 5,000 hp.

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Schematic of the combustion system with plumes from two side-mounted injectors. Source: Achates Power. Click to enlarge.

OP2S diesel engines, as optimized by Achates, offer several efficiency advantages compared to a conventional, four-stroke diesel engine: reduced heat losses; leaner combustion; and faster and earlier combustion at the same pressure rise rate.

Achates Power developed a proprietary combustion system comprising two identical pistons coming together to form an elongated ellipsoidal combustion volume in which the injectors are located at the end of the long axis.

This combustion system enables:

• High turbulence, mixing and air utilization with both swirl and tumble charge motion with the high turbulent kinetic energy available at the time of auto ignition.

• Ellipsoidal combustion chamber resulting in air entrainment into the spray plumes from two sides.

• Inter-digitated, mid-cylinder penetration of fuel plumes enabling larger λ=1 iso-surfaces.

• Excellent control at lower fuel flow rates because of two small injectors instead of a single higher flow rate.

• Multiple injection events and optimization flexibility with strategies such as injector staggering and rate-shaping.

There is no direct fuel spray impingement on the piston walls and minimal flame-wall interaction during combustion. This improves performance and emissions with fewer hot spots on the piston surfaces to further reduce heat losses.

The preferred air system combines a supercharger and a turbocharger.

Primary challenges of OP2S engines that Achates Power addressed included finding an effective way to reduce oil consumption; increase piston compression ring life; manage the thermal loads on the piston and liner; and support 200+ bar cylinder pressures at the wrist pin.

Within 2014, the company has tested two different three-cylinder engines in its dyno test cells. These new engine test results validated the company’s single-cylinder test results and multi-cylinder engine projections with results proving a 32% increase in the thermal efficiency versus production medium-duty diesel engines. To date, Achates Power’s engine technology has been proven in over 6,000 hours of dyno testing.

The Achates Power opposed-piston, two-stroke engine has demonstrated a cycle-weighted average brake thermal efficiency (BTE) of 41.8% with engine hardware and calibration that are still in an early stage of development. Higher engine thermal efficiencies will be achieved through hardware and calibration improvements, some of which are unique to the Achates Power engine architecture and some of which are industry-wide advancements.

In 2014 alone, the company has accumulated more than 1,000 dyno hours of testing and presented its engine results at 11 industry-specific conferences around the globe, including SAE World Congress, SAE Commercial Vehicle Engineering Congress and the International Engine Congress. Achates Power also secured six new US patents and 13 new foreign patents, bring the patent portfolio to more than 1,800 unique innovations, 61 global patents and an additional 90 pending applications.

Given the increasing demand from the global automotive industry, Achates Power has expanded its business development team to enable a regional focus in China, Europe and India. In addition, the company has added 15 people to provide technical development support to meet its growing customer and RD demands.

To accommodate this growth, it has opened an additional office in San Diego. Achates Power expects to continue to hire employees in the next year as the company adds customers and advances its engine technology.

The engine performance test results we’ve shared with OEMs, media and industry, are accelerating all our activities and we are seeing this acceleration from all market segments and all regions of the world. For example, for passenger vehicles, we presented at the SAE World Congress in April that our engines will deliver a 30 percent increase in mpg, while meeting next generation emissions standards in comparison to an advanced diesel engine and an 86 percent mpg increase versus a production gasoline engine.

In September of this year, Achates Power raised more than $10 million in a Series D round of funding, bringing the company’s cumulative funding to more than $100 million. Achates Power is using this additional funding to continue its research and development programs, ensuring that the company stays at the forefront of Opposed-Piston engine technology.

Resources

• Gerhard Regner, John Koszewnik, Laurence Fromm and Zoltan Bako (2014) “Achieving the Most Stringent CO₂ Commercial Truck Standards with Opposed Piston Engine,” (Heavy-Duty, On-und Off-Highway Engines 2014 9^th International MTZ Conference)