Overview of the different applications of water injection in turbocharged and non-turbocharged heat engines
1) During World War 2ieme
Incredibly complex and turbocharged this V-12 engine had to take off in never ideal conditions. These extreme conditions made it necessary to find solutions to exploit the maximum power of an engine, especially when it was an aircraft engine. It was often a matter of life and death. It was then that the technology of water-alcohol injection (alcoholic water) was developed ... To find out more, click here.
Wright Cyclone engine
This research was carried out by people like Sir Harry Ricardo, researchers at NACA Langley and all the aeronautical engine engineers during this period of war.
Rolls Royce Merlin engine.
Diagram of a mechanical regulator for injecting alcoholic water (water + methanol) designed more than 60 years ago.
2) In current marine engines
Large industrial diesel engines currently use water injection systems to reduce their emissions. There are several advantages to injecting water in order to cool the combustion temperature. Companies currently developing this technology are Wartsila et Cummins.
Diagram of a diesel-water injector with electronic regulation.
3) What to remember about water injection
The main conclusions regarding the use of water in heat engines are as follows:
- The injection of water increases the octane number of the mixture.
- The water injection allows the increase of the effective average pressure with a reduced specific consumption.
- The injection has a cooling effect of the internal parts of the engine (piston and cylinder).
- Water injection does not provide fuel economy when fuel is not being used to its thermochemical limits.
- In extreme conditions, the injected water can dilute with the lubricating oil and cause damage.