Is this the end of hydrogen? The first-ever water engine in history
Toyota has been one of the leaders advocating for the use of hydrogen fuel cell technology and the establishment of hydrogen filling stations. Just a few days ago they revealed a new inline 6-cylinder internal combustion engine which they intend to market as being hydrogen-powered.
The idea of developing hydrogen powered engines by Toyota can be traced back to early 1990s. In 2015, Toyota started selling another type of zero emission vehicles – the first fuel cell electric vehicle model marketed to consumers – the Mirai.
The new hydrogen combustion engine is an advancement that enables vehicles to function on hydrogen by using conventional engine systems. This implies the hydrogen cars could use current production and refueling structures during the transition to fuel cells cars.
Rather than hydrogen, it’s a water engine: the detail that has experts in shock
The interesting thing about it is that Toyota has come up with a special kind of water cooled hydrogen combustion engine in a bid to overcome some of the challenges which are associated with burning hydrogen fuel. This engine has a unique proprietary technology that allows direct water injection into cylinders.
It should be noted that the overwhelming majority of hydrogen engines are air-cooled at present. But the chemical properties of hydrogen combustion lead to the creation of temperatures of over 2500°C in the cylinders. This creates a lot of heat stress on the engine components and compels the use of heavy materials.
The rationale behind Toyota’s water-cooled technology is that its cooling system effectively cools the engine block and the cylinder head through the circulation of water. The water thus carries very huge quantities of heat from the combustion chambers.
The use of water cooling enables the engine to be constructed from light materials such as an aluminum instead of steel. This will reduce the weight of the vehicle and hence improving on efficiency by allowing the engine to rev higher.
New type of injection and 2500 ºC: why this internal combustion is non-polluting
The hydrogen combustion engine as produced by toyota operates at a very high temperature of 2500°C as compared to the temperatures in conventional gasoline engines which are around 600-650°C. This uses an ultra-high-temperature range operation due to its water-cooled design.
Now, conventional engines can not tolerate such high temperatures due to the material used in making the engines, but Toyota’s hydrogen engine cooling system is able to extract the advantage of running extremely hot temperature. The high temperature ensures greater combustion and better thermal efficiency.
Toyota’s hydrogen engine is powered by a single cylinder four-stroke gasoline compression ignition engine with a special dual injection system that allows direct and port fuel injection of hydrogen. This enables suitable combustion regulation at all operating speeds.
Direct injection involves supplying hydrogen into the cylinder for combustion where complete combustion is especially achieved at higher engine speeds. The direct injection ensures that a leaner hydrogen charge is supplied only when the engine needs it.
Do you understand why this water engine is so different from the hydrogen engines we knew until now? The fact of making a prototype that is combustion, but zero emissions, seems contradictory in itself. However, it is the kind of “surprises” that the new mobility of the future awaits us and that we have been seeing more and more (in some cases, negative ones, as has happened with EVs).
