A team from the Beijing Institute of Technology (BIT) has devised a control strategy for 2.0L direct-injection hydrogen engines that delivers near-zero emissions with high power and high brake thermal efficiency. A paper on their work is published in the journal Fuel.

Direct-injection (DI) hydrogen engines can generate high power with high thermal efficiency and a low risk of abnormal combustion. However, although hydrogen is carbon-free, eliminating many criteria pollutants, the emission of nitrogen oxides (NOx) remains at a high level in DI hydrogen engines at high loads.

Some studies have targeted reducing NOx emissions based on naturally aspirated or supercharged engines with medium power and efficiency.

In contrast, the present study focuses on a 2.0 L turbocharged direct-injection engine, achieving large power, high thermal efficiency, and near-zero emissions (below 20 ppm without any posttreatment equipment) simultaneously.

The impacts of two effective methods, lean combustion, and retarded ignition are investigated, compared, and combined. An optimal control strategy is proposed and validated under all working conditions from 1000 rpm to 3500 rpm to deal with the trade-off among the power, efficiency, and emissions.

The results indicate that lean combustion can rapidly decrease the NOx emission from 2500 ppm to approximately 100 ppm by reducing the cylinder temperature, avoiding the formation of thermal NOx.

On this basis, retarded ignition effectively reduces remaining emissions to near-zero with only a 2.5% power loss, whereas lean combustion achieves the maximum brake thermal efficiency (BTE). After optimization, a maximum torque of 221 N·m @ 2500 rpm, 73 kW @ 3500 rpm, and 41.2% BTE @ 2000 rpm and 2500 rpm can be achieved by the turbocharged direct-injection hydrogen engine with near-zero emission.—Bao et al.

Ling-zhi Bao, Bai-gang Sun, Qing-he Luo (2022) “Optimal control strategy of the turbocharged direct-injection hydrogen engine to achieve near-zero emissions with large power and high brake thermal efficiency,” Fuel, Volume 325, doi: 10.1016/j.fuel.2022.124913

Posted on 12 July 2022 in China, Emissions, Engines, Hydrogen, Market Background | Permalink | Comments (6)

Hurry-up hydrogen in north-america, build those like the chineses. Gas prices are causing a worldwide resession because of inflation. Hydrogen is the cure, not battery. Two weeks ago i read an article in marketwatch that said it is time to implement hydrogen now.

Posted by: Gorr | 12 July 2022 at 09:03 AM

This is only good for the niche markets where EV's do not have the range ...yet, TBD. "73 kW @ 3500 rpm, and 41.2% BTE @ 2000 rpm and 2500 rpm" is good for a BEV REX. But the fuel cost is going to be crazy high!

Posted by: GdB | 12 July 2022 at 02:25 PM

We really need a zero CO2 emission aircraft engine that will end the leaded fuel use in light aircraft. NH3 could work.

Posted by: GdB | 12 July 2022 at 02:27 PM

' But the fuel cost is going to be crazy high!'

What assumptions are you using?

Cost are falling just fine, and a lot of the drop in prices for hydrogen are pretty much baked in the cake, with falling electrolyser prices etc driving them as volumes increase, before we start on looking at umpteen other possibilities for cost reduction in one of the, if not the, fastest advancing field in technology.

Posted by: Davemart | 13 July 2022 at 01:25 AM

@GdB, "' But the fuel cost is going to be crazy high!' With increasing shortages in the future, fossil fuel cost will be higher and higher. Meanwhile, with increasing development and economy of scale, green H2 will be cheaper and cheaper. We clearly have 2 trajectories, 1 for FF and 1 for Green H2 ... and they will soon intersect and that will be the turning point.

Plus we should not forget the high tolls that FF is exacting on the environment and on our future generations, with climate change, pollution and increasing rates of cancers, autism, respiratory illness...

Posted by: Roger Pham | 14 July 2022 at 02:57 PM

Hear the latest news yet about French Nukes. They have to be throttled down because cooling has become inadequate due to overall rising temperatures. This will result in a further increase of already intolerable high power prices.

Posted by: yoatmon | 18 July 2022 at 06:02 AM

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