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Researchers at Cambridge University have developed a new thermocouple that could significantly extend the length of maintenance intervals and extend the life of jet engines and industrial gas turbines.
The nickel alloy thermocouple is able to operate more accurately at temperatures above 1000 degrees c than conventional temperatures. Research has shown it reduces drift – degradation in a sensor that results in faulty readings – by 90% at temperatures of 1300 degrees C. The new thermocouple could potentially double the lifespan of some gas turbine components, Cambridge University said.
Dr Michele Scervini, the researcher from Cambridge University's Department of Materials Science and Metallurgy who developed the thermocouple, said it could double the length of maintenance intervals in both aerospace and industrial and improve operational efficiency.
Dr Scervini said: “A more stable temperature sensor provides several advantages – a better estimation of temperature can increase the lifetime of engine components and decrease maintenance costs to manufacturers, without any reduction in safety.
“Nickel is an ideal material for these applications as it is a good compromise between cost and performance. There is a gap in the market for applications above 1000 degrees. We believe our device could see widespread usage across a range of industries.”
Most temperature sensors, apart from expensive platinum-based ones, cannot be used at temperatures above 1000 degrees C because of contamination from the oxidisation-resistant sheath used to protect them. However, tests on Scervini's prototype showed the significant reduction in drift at temperatures of 1200 and 1300 degrees C.
The new thermocouple sheath has two layers – an outer wall made of conventional oxidisation-resistant nickel alloy to protect from the exterior and an additional inner wall made from an impurity-free nickel alloy that acts as a barrier agains contamination from the outer wall.
The prototype is being tested further and commercialised by technology transfer company Cambridge Enterprise.
Scervini said the device has attracted interest from a wide range of industries, including for heat treatment machinery and automotive, but that its first application will most likely be in the aviation sector as a result of an EU-funded project with participants that include Rolls-Royce, Siemens and GKN.