Smart sense for oil viscosity

RTE’s Smart Sense has been designed to monitor oil viscosity and temperature accurately at all times, and particularly when switching between fuels on entry to or exit from ECAs, to prevent engine wear and higher emissions attributable to feeding through fuel of the wrong viscosity.

The company says that the density of bunker fuel varies globally and therefore relying upon temperature measurement alone will not guarantee that the oil injected into the engine will achieve maximum combustion efficiency. ‘Viscometers’ have been developed to tackle this issue and have evolved into three specific types – straightforward plunger-based systems, or systems using either vibrating rods or rotating forks to gauge viscosity.

Mike Coomber, managing director of UK-based RTE, says that as well as being driven by the company’s continuing strategy of offering technologies that enhance environmental performance, the development of Smart Sense has been in direct response to industry feedback that currently available products are not robust enough.

“Viscometers are recognised as critical equipment, but the demands being placed upon them are growing as shipowners increasingly need to switch between fuels to meet environmental legislation and drive down running costs,” says Coomber. This is a new niche for RTE, but we are drawing on some 30 years of instrumentation design in the marine market to address a specific industry concern regarding reliability. Not only will Smart Sense last longer than existing systems, it will be available at lower cost.”

“Plunger –type systems are prone to blocking because HFOs contain wax and solid particulates,” continues Coomber. “Removal for cleaning means downtime and aggravation whilst ships’ crews have to revert to controlling this process manually and by reference to temperature only. Existing vibrating rod techniques have shown themselves to be vulnerable in harsh marine environments due to their fragile construction and choice of components. To address this, the Smart Sense viscosity probe is an electromagnetic vibrating rod operating at resonance frequency – a simpler, more robust and reliable alternative. It is now possible to measure temperatures and viscosity with improved accuracy, particularly apparent at low viscosity when switching between HFO and MDO, and without frequent calibration or maintenance.”

The Smart Sense PID (proportional-integral-derivative) module consists of two separate controllers, one measuring viscosity and the other measuring temperature. In case of failure of one controller, the unit can be switched to the other to maintain operation, while the faulty controller is replaced.

Offered with an 18 month warranty, the Smart Sense features standard flanges for easy installation. It also operates at a low frequency, outside the ranges generated by engines and generators. “Avoiding these bandwidths improves the signal, enhancing accuracy and makes Smart Sense immune to shipboard vibrations,” says Coomber.