METRI MEASUREMENTS iCenta and Metri Pro-Lite and the Hybrid Passenger Ferry
VALVES & FLOW CONTROL ULTRASONIC DIAGNOSIS
METRI MEASUREMENTS iCenta and Metri Pro-Lite and the Hybrid Passenger Ferry
We were called to consult on several flow applications on board a multimillion-pound new generation of catamaran hybrid passenger ferry . These fabulous low emission ferries will operate on the Thames and be future proofed incase an ultra-low emission zone is introduced for river traffic .
The vessels designer identified a requirement for three flow measurements to be made . The first was on the diesel fuel consumption on the common rail engine . The second was for the battery cooling circuit and the third was the diesel engine cooling circuit . These ferries have a hybrid motor in each of the two hulls , so that was four measurement points per hull , eight in total . The battery cooling fluid was a water / glycol mix cooled indirectly via a heat exchanger , whilst the diesel engine cooling was raw sea water , drawn up and passed through a strainer . The pipework was all Nickel Copper alloy , DN25 ( fuel lines ) DN50 and DN100 line sizes for the two cooling circuits .
For the diesel flow measurement , a gear flow meter was already installed , but iCenta realised that it was sized incorrectly and was causing a significant pressure loss . A precision OVAL FlowPet 5G gear meter was selected for the task of flow measurement from the diesel flow .
Then the cooling circuits were surveyed , and the ultrasonic sensors were installed within the bilge , access was tight , the space was about 60 cm at its largest point and a person could not turn around . After a risk assessment and gas safety check , the ultrasonic meters were set-up and the sensors installed . It is in such space critical applications a quick setup and small meter , in a rugged bumper case is a definite advantage !
Both the Metri Pro-Lite and the Precision Flow PD190 measured the flow well , particularly on the water glycol mix for the battery cooling . However , it was found that as the engine approached full power , a great deal of entrained air was mixed into the engine cooling fluid which is not ideal for ultrasonic meters , or many other flow measurement technologies , for that matter . Entrained air is not a good conductor of heat and would therefore also affect the performance of the cooling circuit .
The ultrasonic flowmeters proved unsuitable ( due to entrained air ) on the diesel engine cooling circuit , so a different flow technology was required . This remains a natural strength of iCenta , we have all the flowmeter technologies , so we can honestly recommend the best flowmeter technology choice for a particular application , and we represent the best flow instrumentation from around the World .
In terms of diagnostics , the ultrasonics did give us valuable insight into the flow conditions . A combined Doppler – Transit time flow meter is available via iCenta , and this would have been a good application for that device , automatically switching between Doppler and transit-time techniques .
Metri Pro-Lite was fast to set up and easy to operate , having a backlit graphics display for use in low light conditions . Signal diagnostics are available so you can see the acoustic signals in real time . The meter , after the signal amplification is fully digitised , using correlation detection , has effectively become an industry standard signal processing technique for transit-time flowmeters . All these features really help when working with a range of fluids in demanding situations . The Metri Ultra Pro-Lite also sits in a powerful position in the market . Due to intelligent modern design , it is perfectly engineered to provide a capable clamp-on flowmeter , at a realistic cost to the user . iCenta recommend clampon ultrasonic flow meters on site , especially useful for verifying other meters , and for general spot flow readings . The meter also has a fully configurable datalogger for post testing analysis .
Initially we thought that it was a good application for ultrasonics , but due to entrained air on the diesel cooling water it was felt that a magnetic flowmeter was a better choice . Post trial , the new meters were correctly specified sized and delivered , so the overall solution involved Oval geared meters and C-Mag Comac Cal 316L Magnetic flowmeters .
For further information , please visit www . metrimeasurements . co . uk
142 PECM Issue 70