Dual Chamber Two-Stroke stoichiometric DME engine

Pochari Technologies has invented a revolutionary new type of diesel engine for use in current diesel propulsion applications with hugely improved power density and dramatically improvement emission control. The engine is a conventional piston engine where a single-cylinder serves as two separate combustion chambers. A single-piston reciprocates in a two-stroke cycle providing compression in the opposing chamber each power stroke in the opposite chamber. A single-cylinder, with the same stroke length as a conventional engine, can provide the equivalent amount of power as two cylinders. By eliminating one set of connecting rods, crankshaft, piston and cylinder we can reduce engine weight significantly.
The engine is free of a camshaft, valvetrain and crankshaft, radically improving reliability.
As a two-cycle cannot provide vacuum, air must be forced in at high pressure. Electrically driven high speed 4:1 pressure ratio turbochargers are used. In a two-stroke diesel engine, the “blower” or turbo helps in removing as much exhaust as possible at the end of each power stroke and provides the pressure necessary to fill the chamber with enough oxygen.
The injection system is a conventional common rail.
The engine block is 351 high-temperature Aluminum Alloy. This invention allows for increased volumetric power density, and most importantly, a gravimetric power density increase by a factor of 170%.
This technology will be most attractive for weight and volume sensitive applications, such as marine propulsion. As the engine is a “free piston”, rather than using a hydraulic piston, a permanent magnet motor linear generator is used to directly power electric motors which can be connected to each drive axle eliminating the transmission and providing instant torque at low speed.
The lubrication system is proprietary but provides greatly enhanced lubrication over conventional crankcase fed cylinder lubrication as oil is injected directly underneath the oil ring through multiple small orifices at a constant rate and pressure.
Targeted BSFC is below 0.35 lbs/hp/hr. Power density is estimated to be approximately 2 hp/lb.
CR is 17:1.
No EGR and SCR is needed thanks to the stoichiometric operation enabling conventional platinum monolith TWC technology to reduce by up to NOx 99.95% with the addition of a small amount of hydrogen gas as a reducing agent. The absence of C-C bonds in DME provide near soot-free combustion, eliminating the need for a DPF. Concerns about injector wear as DME possesses much lower lubricity are alleviated by the use of specially designed hydrogen style injectors. Dimethly Ether is an ideal fuel for diesel engine as its cetane number exceeds that of conventional diesel fuel. The fuel is clean burning, energy dense an easily liquefied at moderate pressures, 7.5 bar.
This engine will greatly exceed all modern diesel emission standards while providing efficient trouble-free service to operators. For those interested, Please contact Christophe Pochari.


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