Study Looks to Revolutionise Rail with Nanofluids

13 April 2010 (Last Updated April 13th, 2010 18:30)

It is hoped a Europe-wide study into railway engine cooling systems will achieve a 40% improvement in engine efficiency, which could lead to installations as early as 2015. Researchers at NanoHex, led by Thermacore Europe and supported by 12 other companies and research centres, said th

It is hoped a Europe-wide study into railway engine cooling systems will achieve a 40% improvement in engine efficiency, which could lead to installations as early as 2015.

Researchers at NanoHex, led by Thermacore Europe and supported by 12 other companies and research centres, said they believe nanofluids will allow electric trains to operate on higher voltages, improve efficiency and run with greater reliability.

Nanofluids are regular cooling liquids with added ceramic or even metallic particles made from aluminium nitride, aluminium oxide, titanium oxide, copper or carbon, which absorb heat more effectively.

Siemens AG, the Swedish Royal Institute of Technology, Ingegnera Sistemi Impainti Servizi in Italy, UK-based Dispersia, the Technical University of Eindhoven in the Netherlands and the UK's university of Birmingham are all involved in the $11m project.

Siemens AG Corporate Technology's' Dr Gerhard Mitic said the research is looking to provide the industry with an answer to the majority of rail failures, which are caused by ineffective cooling.

Mitic said he hopes research and development will be finalised in three years, after which real-world testing will take place before selective customers will have the chance of implementing the system.

Electrical power systems are usually cooled using water glycol, a mixture of between 30%-60% water - with an antifreeze such as ethylene and polyglycol as a thickener, to allow the coolant to work at temperatures of below 400C.

Unfortunately, water glycol does not have a high connectivity which means it is difficult for the cooling plate to reduce the heat levels effectively.

The addition of the nanoparticles, which have a high connectivity, should allow for a much more efficient system of heat removal from train locomotives and from any other kind of power electronics.

In a normal water-cooled engine the liquid passes between the cooling plates, which are usually made of aluminium and have a high connectivity and surface area, which removes the heat from the water and transmits the excess heat into the air.

With nanofluids the particles collect most of the heat and due to their own high connectivity transfer more of the heat to the plates thereby improving engine cooling.

The particles used at the moment are between 10 and 100 nanometres, with a bacteria being 1000nm, but originally research was done using particles measured in micrometres.

Mitic said these had several disadvantages compared to nanoparticles as their size caused damage to parts of the engine, especially the cold plate, and over time they lost performance and sank to the bottom.

With the introduction of the small particles the process is not only more efficient but the cooling liquid has an increased life span of up to five years.

According to Mitic, for every drop of 100C in the engine the reliability increases by a factor of two which would result in a staggering improvement in the efficiency of not only the engine but rail systems in general.

When fully operational, the system could be used on any train powered by electricity including high speed trains and all manner of electrically powered machinery.

The particles used at the moment are between 10 and 100 nanometres, with a bacteria being 1000nm, but originally research was done using particles measured in micrometres.

Mitic said these had several disadvantages compared to nanoparticles as their size caused damage to parts of the engine, especially the cold plate, and over time they lost their performance and sank to the bottom.

With the introduction of the small particles the process is not only more efficient but the cooling liquid has an increased life span of up to five years.

According to Mitic, for every drop of 100C in the engine the reliability increases by a factor of two which would result in a staggering improvement in the efficiency of not only the engine but rail systems in general.

When fully operational the system could be used on any train powered by electricity including high speed trains, and all manner of electrically powered machinery.