260 likes | 635 Vues
Ultrasonic ™ Gas Leak Detection. E VERY L IFE H AS A P URPOSE…. Ultrasonic Gas Leak Detection.
E N D
Ultrasonic™ Gas Leak Detection EVERY LIFE HAS A PURPOSE…
Ultrasonic Gas Leak Detection Increase detection reliability and reduce risk as ultrasonic gas leak detection provides instant and verifiable detection of gas leaks. The ultrasonic technology will detect pressurised gas leaks instantly regardless of gas dilution and ever changing weather conditions found on most on- and offshore installations in the petrochemical industry.
Application Area Applications for Ultrasonic Gas Leak Detectors: • Instant detection of flammable gas leaks • Fixed installations • Explosion hazardous areas • Pressurized gas installations • Outdoor or semi outdoor ventilated areas • Electrical connection to DCS system or fire and gas panel
Ultrasonic Gas Leak Detection WHAT is Relevant to Detect? In plant installations with pressurized flammable gases, it is relevant to detect gas leaks that can accumulate into a potentially explosive gas cloud. WHEN is it Relevant to Detect? As fast as possible - to prevent build-up of dangerous concentrations. Accumulation of gas can lead to explosions.
What Creates an Explosion? Three main factors determine if a hydrocarbon gas leak can create a catastrophic explosion: 1) Oxygen 2) Ignition Source 3) Gas Concentration The amount of gas released over time from a gas leak is known as the LEAK RATE and has units of kg/s.
Leak Rate vs. LEL Important Parameters to Know in a Gas Leak Detection Situation: Lower Explosive Level (% LEL): A concentration measurement in a pre-defined point that may create a true picture of the nature of the gas leak. Leak rate (kg/s): Detection related to the leak rate, makes it possible to introduce a performance standard for the gas leak detection system. Example: Gas leaks with a leak rate of 0.1 kg/s or more must be detected.
Real Gas Leak Test with Ultrasonic Detectors Live Gas Leak Test on a North Sea Off-Shore Installation: Within 4-5 meters the gas concentration around the leak was below 5% LEL! None of the existing gas detection systems alarmed! Leak size: 3 mm Gas pressure: 55 bar (808 psi) Leak rate: 0.06 kg/s The ultrasonic gas leak detector detected the leak up to 19 meters away!
Ultrasonic Gas Leak Detection Main Characteristics: • Instant acoustic gas leak detection • Detects gas leaks at a leak rate of 0.1 kg/s • Detection radius up to 20 meters away • Unaffected by changing wind direction and fast dilution of gas • Minimal maintenance and calibration requirements
Acoustics and Gas Leaks • Gas molecules travel from high pressure to low pressure • Hissing sound • Acceleration of gas produces “white noise,” which consists of both audible and ultrasonic sound components • Acoustic detectors filter the audible range – responding to sound in frequencies from 25 kHz to approximately 50 kHz – far higher than frequencies human hearing can detect • Ultrasonic leak noise is proportional to the leak rate
Leak Detection Range • The detection range of an ultrasonic gas leak detector depends on these variables: • Leak size • Pressure • Ultrasonic background noise Leak size and gas pressure determine the acoustical ultrasonic noise level generated from the leak.
Limitations • Traditional Technologies Can Be Problematic • Changing wind directions • Gas dilution • Direction of the leak • Acoustic Technology Limitations • Low pressure (normal application of 10 bar and higher) • High background noise ( > 90 dB) – although rare
UltraSonic EX-5 Gas Leak Detector Main Features: • Senssonic™ integratedacoustic self-test • Standard 4-20 mA analog output • RS 485 serial digital communication interface • Explosion-proof housing in solid 316L stainless steel for extreme environmental conditions • Minimal calibration and regular maintenance • Robust microphone technology to ensure long MTBF • FM, CSA, C-UL, ATEX, IECEx, GOST certified for hazardous areas
How to Ensure Failsafe Operation? Senssonic™ Built-In acoustic Integrity Test • External loop configuration • Controlled functionality and integrity test every 15 minutes • No un-revealed failures between inspections • 4-20 mA signal indicates any abnormalities (to 1 mA for 5s) UltraSonic EX-5- Test Transducer
Installation Practice • Allocation of Ultrasonic Detectors Based On: • Plant details and layout • Ultrasonic background noise mapping survey • Installation of Ultrasonic Gas Leak Detectors • System Commissioning, Performance Verification • Test with portable test and calibration unit • Actual leak simulation with nitrogen
Installation on Existing Installations Background noise mapping and detectors allocation
New Installations - Allocation • Detectors installed at elevated position (approx. 2 m above potential leak sources) with the sensor head facing down. • Avoid solid decks or big vessels blocking path between leak spots and detector. Heavy piping does not block the sound to the detector.
Commissioning, Testing, Calibration • Commissioning: • 1701 Portable Test and Calibration Unit • Live leak simulation of 0.1 kg/s gas leaks (using nitrogen gas) • Testing and Calibration: • 1701 – Traceable, calibrated test and calibration unit • Gain test and field calibration if required (every 6-12 months)
Typical Applications • Offshore oil and gas platforms • Onshore oil and gas terminals • Floating production storage and offloading vessels (FPSOs) • Gas compressor and metering stations • Underground gas storage facilities • Downstream chemical processing plants (e.g. ethylene, methanol, ammonia, and propylene) • Hydrogen storage facilities • Refineries • LNG/GTL trains (plants) • LNG re-gasification plants • Gas turbine power plants
Installations Worldwide Most Major End-Users in Oil & Gas are Implementing UltraSonic Detectors for Projects Worldwide • North Sea: England, Denmark, Holland, Norway (Sleipner, Gullfaks) • The Americas: USA, Canada, Trinidad & Tobago (Cannonball) • Middle East: UAE, Oman (Saih Rawl, Saih Nihyada, Al-Kawther, Harweel) • Far East/Central Asia: China (Bohai Bay), Malaysia (Shell Bintulu), Pakistan (Rehmat), Indonesia (Tangguh) • Africa: Equatorial Guinea (Marathon ALBA), Algeria (Hassi Berkine) • Caspian Sea Region: Azerbaijan (Shah Deniz), Russia (Sakhalin II), Kazakhstan (Kashagan)
Conclusions Why Ultrasonic Gas Leak Detection? • Reduce risk • Instant and reliable detection • Unaffected by changing weather conditions • Possible to pre-define safety standards and verify system performance • No undetected failures: Built-in self-test function • Cost effective – reduced total cost of ownership For more information, visit our website www.msanet.com
UltraSonic™ EX-5 Gas Leak Detection EVERY LIFE HAS A PURPOSE…