29 November 2013

Petronas Patented Water Injection Engine?

Toyota last month openly said that it will buck the engine downsizing trend (and turbocharged) and instead will focus on developing an efficient large capacity gasoline via the optimization of Atkinson cycle, a knowledge it has honed to perfection in developing the pairing to its hybrid series. It was also mentioned in the source that Toyota will venture in the innovation of water/steam injection to enhance engine efficiency. Now this is breakthrough as engine typically breathes air and fuel, mixed for combustion.

Wow people said. It is indeed a novel concept with curiosity, as for the layman understanding, how can you ignite a fire and then spray water to it? Contradicting it may sound, but if you go to the SAE paper database, a place where all automotive engineers breath, eat and drink car, you'll found plenty of invention of water being injected into the cylinder. There's even a six-stroke concept.

What strike my eyes is the technology has also been patented by our local hero. Do you know Petronas has patented such technology years ago? Check it out here in Google Patent, Espacenet and SAE technical paper. While we don't know what Toyota technology is all about apart from injecting water/steam into combustion chamber, according to patent W02010036093 A1, Petronas novel internal combustion aim to maximise the heat generated by fuel combustion to expand water into steam which in turns utilized the heat that is otherwise wasted. The water expansion into steam exert the force in the power stroke instead of purely forced by the ignition of compressed air and fuel mixture. The low combustion efficiency currently occurring in our current engine results in un-burn hydrocarbon which goes to the exhaust line. There is an attempt to increase the combustion efficiency, but the high heat release in doing so could result in Nitrogen  Oxide (NOx) formation which started to happen at around 2000K combustion temperature.

In the normal internal combustion engine, of all the fuel combusted, two-third comes out as heat, which is then absorbed by the cooling system recirculating around the water jacket.  In a typical engine system, the jacket is located inside the cylinder block and cylinder head and it goes around collecting heat and dissipate it in the radiator system. Figure below shows the cooling jacket residing in your engine block, photos courtesy of RGBSI. In terms of energy, this is energy wasted.

In Petronas patent, water is injection post the fuel combustion and to capitalize on the heat via clever, patented system. In doing so, not only less heat is emitted as, well heat, it also will reduce the engine temperature when the excess heat is converted into energy. Energy conservation remember? So the cooling system potentially can be reduce, resulting in smaller radiator. The exhaust gas too is cooler and this in turn reduce the thermal loading applied to the exhaust manifold (also cylinder block and head) which means overall engine is subject to a reduced thermal stress. Of course there is an additional combustion load which would negate the structural savings due to thermal, but this can be optimized further, at least this my interpretation of all these things. The schematic shown on this patent of Espacenet is as below, you can go through the claim to understand the concept. It is far too long for me to read!

With the engine technology resides under Petronas umbrella has been sold to DRB HICOM, could this be one of it? Whatever it is, which ever way Toyota might be doing what it said in the news, you've got to know our locals has been there as far as innovation is concern. 

Disclaimer: All the items written are based on the information available in public domain i.e patent and open, paid automotive literature. 

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