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We will start shortly…. Leakage Detection for Toxic Chemicals Presented by: Riccardo Belli – PLM Distributed Sensing. Web Seminar. You should hear my voice through your PC speaker / headset
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Leakage Detection for Toxic ChemicalsPresented by: Riccardo Belli – PLM Distributed Sensing
Web Seminar • You should hear my voice through your PC speaker / headset • You can ask questions using the “Questions” panel on the right of your screen. We will answer: • In the “Questions” Panel • At the end of the presentation • By email • Later this week you will receive link to: • Presentation in PowerPoint, PDF and with narration • Datasheets
Contents • Context – motivations • Fiber optic sensors Technology • Leakage detection • Application examples • System reliability – Level of confidence • Questions and answers
Context Context – motivationsfor leakage detection
Historical dates of industrial accidents 1966. Feyzin (France) -Explosion of 2 propane storage tanks 18 deaths and 84 injured 1976. Seveso (Italy) - Toxiccloudcarrying dioxine - 4 villages coveredby the cloud - About 37 000 people impacted (no immediatedeaths)
Historical dates of industrial accidents • 1984. Bhopal (India) • -Explosion of 40 tons of toxicgas (isocyanate of méthyl) • - 8 000 deaths the first night • 16 000 and 30 000 deaths • 2001. Toulouse (France) • - Explosion of the fertilizer plant AZF • - 30 deaths • - 3 000 injured • - Destruction of infrastructures • and housings
Historical dates of industrial accidents • 2010. Ajka Alumina (Hungary) • Release of 600 000 tons of redmuds • (arsenic, mercury and lead) spilledfrom • open air storage tanks • 9deaths and200 injured • Critical environnemental damage • (soils and rivers)
Reglementation • The reglementation (SEVESO II) focus on the prevention of major accidents on industrial sites such as fire, explosion or release of toxicgases. • In thisframework, the industrial site ownerbuilds up a riskanalysis in order to identify all the accidents whichcanoccur, to evaluatetheirprobability, gravity, and cinetic and to implement the appropriatepreventionmeasures. • The leakagedetectionacts as a safetybarrierallowing to reduce the risksat source.
FO DistributedTechnology Technology of Distributed Sensors
T, ε T, ε Optical Scattering in Silica Fibers Scattering of light Scattering medium Laser,lo
Temp. [°C] Position [m] Distributed sensing Reading Unit T1 Distributed Sensor 0m T2 1m 100m T1 1000m T2 30km
Distributed sensing • Single fiber optic sensor (sensing cable) • Every segment (1 - 2 meter long) of sensing cable replaces discrete temperature sensor • Complete temperature profile over the entire cable obtained by single scan (10 seconds) • Provides for location of the temperature event (1 – 2 meter accuracy)
Advantages of Fiber Optic Sensors • EM fields immunity • Installable in explosive areas • Small size and lightweight, easy to install, low maintenance • Durability and reliability of sensors • High sensitivity to temperature (0.1°C) • Permanent monitoring • Long measurement range (several kilometers) • Quick response time (10 seconds) • Software adaptable to various operation conditions, climatic conditions • Cost-effective
Workingprinciple Leakage detection principle : Temperature anomalies analysis
Leakage Detection • Temperature profiling along pipelines/storages • Leakage detection through temperature anomalies analysis at the leakage point • Change of the cable temperature due to liquefied gas relaxation • Cooling due to gas expansion • Change of the cable temperature due to liquid spilling • High sensitivity for the detection of micro-leakages • Identification of the leakage location with 1 – 2 m resolution.
Leakage Detection Pipeline leak temperatureeffects warming cooling Oil or hot liquid pipelines Liquefied gas (Ammoniac, CO2, Ethylene…) High pressure gas (natural gas) T/ °C T/ °C time time
Leakage Detection - liquid Sensing fibre cable Leakageisdetected by the temperaturedifferenceinduced by the presence of the releasedfluidon the sensingcable (temperature of the liquiddifferentfrom the ambientcabletemperature) Leakage Temperature Position
Leakage Detection - gas Sensing fibre cable Leakageisdetected by the temperaturedrop of the gasinduced by the decompressionof the leakinggascausedby the Joule-Thompson effect (pressure relaxation to atmospheric pressure cooling) Temperature Leakage Position
Reading unit System components • Distributed temperature sensor (cable) • Rugged, watertight, corrosion resistant • Low/High temperature and shock resistant • Insensitive to EM fields • Easy and rapid to install Temperature Sensor cable • Range of monitoring up to dozens of kilometers • Temperature accuracy: 0.1° C • Spatial Resolution: 1 meter • Response time: 10 seconds • Permanent monitoring • Leakage detection software • Remote monitoring via Ethernet
Temperature sensors Mechanically reinforced temperature cable N° of sensors: up to 4 Multi Mode optical fibres per cable Cross-section: 3.8 mm with PA sheath Cable weight: 22 kg/km with PA sheath Temperature range:-55°C to +85°C in long-term -65°C to +300°C in short-term -60°C to +85°C storage
Alarms can be triggered on the reading unit or on the database User can set various actions tocommunicate an alarm: ex. email, relay control, text message, etc. Alarm software Warning!!! – Temperature event at 430m E-mail SMS Relay/Modbus Network
Absolute temperature - alarm • Alarms triggers if absolute temperature is exceeded : suitable for situation in very stable environment Temperature at point (x) Temperature at time (t) Ambient Temperature very stable Length along cable Time Alarm triggered if pipeline leaks and temperature drops Leak triggers alarm
Temperature at time t Max day temperature Typical temperature drop= 0.05 °C/min Max normal temperature = 40°C Absolute temperature alarm set to 60°C 24 hours 40 10 Time Night time temp Rate of change - alarm • Alarms triggers if rate of change is exceeded : suitable for dynamic but predictable environment
DiView graphical user interface Dams Dikes
Application examples Application Examples
Ammonia pipeline monitoring • Leakage detection of an ammonia rack pipeline in a fertilizer production plant • Yara Italy – Norwegian world leading supplier of plant nutrients in the form of mineral fertilizer
Rack pipeline outline • 2.200 meters of ammonia rack pipeline • Material: carbon steel • Diameter: 2” & 4” • Working pressure: 16,5 bar • Design pressure: 20 bar at max 50°C • The ammonia inside the pipeline is in liquefied state. In case of leakage, the ammonia goes out at atmospheric pressure both in liquid and gas states at approximately - 30° C • The aim of the monitoring is to detect leakages by continuous temperature monitoring
1 X 2 X Main JB JB with splice 1 X DiTemp DTS-SR inside the Control Room Junction Box 2 X JB with splice Installation layout
Temperature distribution Temperature response over the monitored part of the pipeline measured during the setup of the system
Ammonia pipeline monitoring Leakage simulation on ammonia rack in France • From storage tank to truck and wagon loading arms : 900 meters • Material: carbon steel • Diameter: 6” • Working pressure: 8 bar • Outside temperature : 0°C • Nominal flow : 100 tons / hour • Optical cable located below the pipeline
Leakage simulation 2 tests wereachieved by spillingammonia on the pipeline : • Test 1 : 1 kg of ammoniac over 1 meter over 1 minute (equivalent to 0.06 % of the nominal flow) • Test 2 : 0.5 kg of ammonia over 0.5 meter over 1 minute (equivalent to 0.03 % of the nominal flow)
Test results Data aftertreatment by suitablealgorithm Detection of micro leakages (lessthan 0.1 % of the flow), attenuation of transientphenoma (pumps) Threshold for leakagedetection pumpsstart Test 2 Test 1
System reliability System reliabilityConfidence
Redundancy DTS DTS If red sensing cable is broken the DTS will still measure either side of the break. The blue sensing cable will still measure the entire pipeline length. If blue sensing cable breaks the DTS will still measure either side of the break If one DTS fails, the redundant DTS stills operates
SIL equivalence • Based on the « proven by experience » approach • A combination of redundant architecture & tests allow a SIL equivalence: • Redundancy: two/three interrogators and cables • Voting systems (1oo2 or 2oo3) • Positive security • Regular test on the line (ex : with CO2 bottle) • Regular maintenance
General conclusions • Distributed Fiber Optic sensing is a novel, but well proven technology to detect toxic chemicals leakages in industrial sites (SEVESO classified) • It offers unprecedented sensitivity to detect very small leaks in a few seconds and allows the localization of the leak with meter accuracy, which cannot be detected by conventional techniques • Appropriate architecture and testing program guarantee a high level of confidence to the system • The deployment of such system has been carried out successfully in a number of reference and qualification projects worldwide
Thankyou! Any question? Conclusions – Leakagedetection Safety first