M.J. Yan
Yan Engines, LLC,
United States
Keywords: internal combustion engine, 2-cycle/4-cycle hybrid, diesel/gasoline hybrid, efficiency
Summary:
Currently billions of ICEs (Internal Combustion Engines) continue to power key sectors of the global economy after serving humanity for centuries, moreover the electric Vehicles (eV) are found not ready yet after half a decade of trial. Two of the three alternatives (eV, hybrid eICE, and Advanced ICE) still need those good old ICEs. Therefore, it is good to continuously improve the ICEs’ efficiency and sustainability: We have patented the revolutionary split-piston design which separates the crown section from its skirt to be operated via a (valvetrain-like) piston-train. This split piston completes the 4 strokes, different in both displacements and periods, in every revolution - called D-cycle (differential-stroke cycle). This is a hybrid of the current 2-cycle and 4-cycle. Which can retrofit exist (or new) engines to have become the D-cycle. The D-cycle can in turn retrofit the Diesel-Gasoline combustion ICEs to be “Diesoline” hybrid engines, because it (especially with electronic piston-train control) can control the cycle-to-cycle variations of the 4 strokes for the transient operation of the ICEs due to the high (~30%~50%) exhaust gas retention capacity. Current exhaust gas recirculation cannot provide high (>30%) rates. The Diesoline hybrid ICEs will eliminate the soot and NOx emissions, which are especially costly and troublesome for heavy diesel engines. Current gasoline ICEs can benefit with the Disoline combustion with higher compression ratio without knocking. The Diesoline ICEs can benefit from 2-stroke’s power and torque, the 4-stroke’s cleanliness, Diesel’s fuel efficient, and gasoline combustion’s cleaner emissions which is easily treated. emits harmful soot and NOx exhausts need expensive and nasty exhaust after-treatments, while the gasoline engine is cleaner needing only simple and cost-effective catalyst treatment. The piston-train is synchronized with the crankshaft, which eliminates the reduction gear system saving cost (and weight for light aircraft). This technology can retrofit existing engines or new engines with half of the cylinders or fewer. For cars the new advanced ICEs have fewer than 4 cylinders instead of the v8, especially for e-hybrids to fit into hood space. Current gasoline vehicle engines can be retrofitted to make the whole engine work to gain 2.5 times or more torque (power) and >20% fuel efficiency (tested) with D-cycle and additional ~15% efficiency gain with Diesoline hybrid (totaling to about 1/3 more.) The new car engines can be redesigned to have only up to 4 cylinders (not v8) alone or easily combined to e-hybrid. These new retrofits can potentially gain up to 1/3 total fuel savings for these vehicles including cars, trucks, ships, and tanks. It can further retrofit diesels to eliminate the costly soot and NOx aftertreatments in diesel engines. The new engines can be designed to have these savings with greatly reduced cylinders, sizes and weight. This retrofit business can be readily started on existing ICEs without long delay. However, it will be much better to redesign new engines to maximize all the benefits of the innovation.