TOKYO – Toyota has filed a patent application for an engine that includes water injection valves to intake ports for the combustion chamber. CarBuzz discovered the patent at the United States Patent and Trademark Office.
The patent explains that the water could either be injected as the intake valve is opening or as it’s closing, meaning that it won’t be spraying constantly. Toyota says it’s no biggie if water flows into the cylinder as it will evaporate if the droplets are small enough. If water makes it through to the crankcase, it may mix with the oil, but it’s more likely it will evaporate due to the internal pressure.
This particular patent is for a hydrogen fuel engine, but not like the unit you’ll find in a Toyota Mirai. This is a hydrogen combustion engine, which is an entirely different design. Basically, it runs almost the same as any other combustion engine but uses hydrogen gas to create the necessary explosions. Toyota showcased an AE86 Concept with a hydrogen combustion engine earlier this year.
Each cylinder has two water injection valves, with the first injecting water into the first intake port. The second injects water into the second intake port. One injection port for when the valve opens and one for when it closes.
Why? In a standard engine that uses traditional fuel, the cylinder is cooled by the latent vaporization of the fuel. In a hydrogen combustion engine, the temperature inside the cylinders is higher, which means abnormal combustion can occur. So, instead of using latent fuel vaporization, Toyota wants to use water. Naturally, all of this will be controlled by the ECU.
The ECU will keep an eye on the operating state of the engine and will determine the amount of water that needs to be injected. It’s a fairly complex setup, but the basic concept is that Toyota found a way to cool a high-performance hydrogen combustion engine.
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