In internal combustion engines, water injection sprays water into the incoming air or fuel-air mixture, or directly into the cylinder where "hot points" could produce premature ignition.
Water injection has been used in motor sport and notably in drag racing. In Otto cycle engines the cooling effects of water injection also allow for greater compression ratios by reducing the problem of engine knocking (detonation). Alternately this reduction in engine knocking in Otto cycle engines means that in some applications significant performance gains can be obtained when water injection is used in conjunction with a supercharger, turbocharger and/or other modifications such as a more aggressive ignition timing.
Depending on the engine, improvements in power and fuel efficiency can also be obtained solely by injecting water.
Water has a very high heat of vaporization. As the ambient temperature water is injected into the engine, heat is transferred from the hot cylinder head/ intake air into the water. This causes it to evaporate, cooling the intake charge. A cooler intake charge means it is more dense (higher volumetric efficiency) and also will have a lower tendency to knock. However the water vapor will displace some air, negating some of the denser intake charge benefit. Knocking is generally more of a problem in forced induction engines rather than naturally aspirated so this can be a useful aid in its prevention. On electronic ignition systems the ignition timing is generally retarded to prevent knock from occurring but with water injection it can be advanced closer to Maximum Brake Torque (MBT) timing for additional power.
Composition of fluid
Many water injection systems use a mixture of water and alcohol (often close to 50/50), with trace amounts of water-soluble oil. The water provides the primary cooling effect due to its great density and high heat absorption properties. The alcohol is combustible, and also serves as an antifreeze for the water. The main purpose of the oil is to prevent corrosion of water injection and fuel system components; it may also assist in engine lubrication when running in a high power state. Because the alcohol mixed into the injection solution is often methanol (CH3OH), the system is known as methanol-water injection, or MW50. In high performance automotive applications some tuners use 100% methanol as opposed to a water-methanol mixture and then referred to simply as "methanol injection". Safety concerns and part longevity concerns keep this as a controversial option. - Extracted from Wikipedia
2 comments:
The process of water injections in the oil fields is a significant part of crude oil extraction and the drilling of the oil fields. Water flooding or water injections are used to stimulate the production of oil. The water injection wells are a commonly used tool in the crude oil extraction and are used to increase recovery of oil from the offshore and onshore oil reservoirs.
Voidage Replacement:
This is the term that is used to explain the phenomenon of water injection. The pressure of the reservoir is supported by water injections that push the oil out of the reservoir and into the water well.
The oil extraction can only be conducted successfully up to 30% without the water injection process. With the water injection process, the production rate of crude oil extraction increases up to a significant level.
History:
Water treatment flooding was discovered by accident in the Pithole, Pennsylvania in 18565 when an oil field was accidentally flooded with water but it also brought out much more oil than usually extracted. This discovery led to using water injections to extract oil and the practice grew common in Pennsylvania in the 1880s.
Sources of injected water:
The sources of water used for injection are diverse and varied. Here are a few sources of injected water that are regularly used:
Produced Water:
The term produced water means the water that was previously used int eh injection process before and is now the disposed water from the crude oil. This water is preferred because disposing of the water is complex, it can’t be thrown into a water stream without causing severe water contamination. The water also has a high degree of hydrocarbons and that makes it much more complacent for the oil injection processes.
Seawater:
Seawater is a great choice for the water injection processes but the water is used less often because the water has a high content of salts and it exceptionally prone to causing corrosion and erosion issues in the pipelines that are supplying water to the well. The water will also increase the salt content in the crude oil at an exceptionally high rate. That is why the seawater is only used after filtration.
Aquifer Water:
This is a form of underground stored water that usually forms near the oil field. If it is available then it is the best reservoir of water in the system to use. The reason is that this is a reservoir of pure water that will not need to be purified and will not tinker with the crude oil concentrations.
The reason water treatment is taken so seriously is that open water sources have a vast and extensive form of water contamination risks. From nuclear waste material to biological life forms, the crude oil can be exposed to any kinds of impurities.
Interesting, but this is may not be the best forum for your post.
Post a Comment