Innovation » Minova develops breakthrough product for power industry
Minova develops breakthrough product for power industry
Minova has applied its expertise in special-purpose grouts in underground mine environments to help develop a breakthrough product for the power industry.
This new cement grout for the power industry (BluCem EA55) alleviates the adverse effects of heat on underground power cables, a major problem for power distributors worldwide.
The company's Technology Manager, Robert Hawker, says Sydney-based civil specialist Bluey Technologies approached Minova to help develop the product for its client, Energy Australia, the energy utility of the New South Wales Government.
Bluey had identified the potential solution for the power industry and wanted a product that could deal with two problems at the same time.
"The first issue was the heat generated by cement grouts as they cure. Ordinary cements can easily reach temperatures of 90˚C in the first few hours of curing, while some can reach temperatures of well over 120˚C.
"The maximum operating temperature for polyethylene and PVC insulation housings around electrical cables can be as low as 60˚C, so there is potential for major damage when running ordinary cement grouts into an underground cable duct."
He said the second issue was thermal resistivity, the reciprocal of thermal conductivity.
"It's simple physics that an electrical current generates heat as it runs through a cable. If the materials surrounding the cable - such as a cement grout - can dissipate heat more efficiently, the cable can be rated to carry more current.
"The thermal resistivity of the materials around the cables is actually a big factor in the efficiency of electrical networks. An improvement in thermal resistivity means less heat near the cable and a greater current-carrying capacity. It also has significant benefits for cable life. This could provide big economic benefits because of the high capital costs of electricity infrastructure.
"A solution to the issues raised by Bluey therefore promised major benefits for Energy Australia and its millions of customers," Robert said.
He said Minova started work about a year ago by looking at solutions it had developed for underground mine customers.
"Developing a grout with a low curing temperature was not difficult for us. We had already formulated these kinds of grouts for certain applications in underground mines.
"A standard cement grout used to fill a large underground void will crack because of the high temperatures on curing. That creates structural weakness and is unacceptable in an underground mine.
"In response to client needs, we had already developed low-curing-temperature grouts that did not create problems such as thermal cracking."
Robert said the issue of low thermal resistivity was more complicated. Minova's chemists and engineers worked in the company's Nowra laboratory to test different types of low-resistivity materials that could be used as fillers in cement grout.
"We not only needed a material with the right thermal properties, we had to be sure it could stay well mixed and not create pump blockages, especially when significant distances were involved.
"Once again, our experience in the mining industry could be applied. We have already developed cement grouts for underground coal mines that can be pumped over hundreds of metres and even down boreholes from the surface to fill large cavities underground."
Laboratory tests showed the new product had a thermal resistivity as low as 0.60 Km/W, compared to known values for common soil and ordinary concrete materials which can range from 1.2 to 4.0 Km/W. .. These improvements to the thermal resistivity of encasement materials allows the energy providers to supply substantially more power through new and existing infrastructure.
Minova worked with Bluey and Energy Australia to trial the new product in a variety of conditions. A series of pumping trials were also conducted, which resulted in further refinements to the formula and the selection of the best system of pumps and other hardware for applying the product.
Energy Australia has adopted the new product and is seeking to specify it as a minimum requirement on certain critical high voltage cable ducts.
Blucem EA55 is also set for launch on the wider market. The new product and the special-purpose application systems will be available through Bluey, while Bluey and Minova will provide technical advice and support.
"We have already had significant sales to Energy Australia. We can certainly see potential for this product with electricity distributors in Australia and around the world.
"There is nothing else like this product on the market, certainly not in Australia and to our knowledge not anywhere in the world. The product has excellent benefits for power distributors worldwide and we think it has a very exciting future," Robert said.
For more details please contact:
Robert Hawker
Technology Manager
Email: robert.hawker@minovaint.com
