A portable tool to detect leaks in large diameter pipes AGBAR

Transcription

1 A portable tool to detect leaks in large diameter pipes Francisco Aguado AGBAR São Paulo, June 8 th, 2010

2 Project context (1/2) Common (acoustic) leak detection systems can not be used in many cases: Plastic pipes Low pressure Large Diameter Mains Bad sound propagation Need for close access points Linear network low efficiency (pipe length/radius of detection) Walking the main and Water Balance still are the most usual methods. WATER LOSS 2010 São Paulo 2

3 Project context (2/2) Several solutions can be applied (SAHARA, GPR, SmartBall, Aerial Thermography, Tracer gases) Main problem: cost and availability Application constraints WATER LOSS 2010 São Paulo 3

4 Tracer Gas method for pipes in operation Gas injection (Helium or Hydrogen) into the pipe Dissolution and transport Leak of marked water Gas desorption Above ground detection WATER LOSS 2010 São Paulo 4

5 Characteristics of Tracer gases Both Helium and Hydrogen satisfy the required conditions Constant, low atmospheric concentration Lighter than air, high diffusion rate No physiological activity, approved for alimentary purposes Helium gas is more expensive than Hydrogen, but It is not explosive (quite the opposite of Hydrogen) higher (20x) concentration can be used It remains detectable in the soil for 5 days allows much longer inspections It is a noble gas, completely inert WATER LOSS 2010 São Paulo 5

6 Previous solutions for Tracer Gas (1/2) Most common H 2 and He leak detection systems work only on empty pipes service interruption He/H 2 solution for live (in operation) pipes H 2 allows only some hours of inspection after injection He system uses a non-portable lab equipment for detection Gas is directly injected into the pipe bad dissolution No data recording Solution for water heating networks Water is pumped out of the network An absorption tower is used to dissolve Helium Marked water is reintroduced in the pipe WATER LOSS 2010 São Paulo 6

7 Previous solutions for Tracer Gas (2/2) Problems associated to direct injection At least 300 m of pipe to get gas dissolution Only part of the gas is finally dissolved (low performance) Gas escapes through vents Gas accumulations can affect network service Frequent false leak detections where only non dissolved gas escapes WATER LOSS 2010 São Paulo 7

8 The idroloc injection system (1/2) Gas bottle Pressure reduction and gauge Flow control Diffuser Watertight connection Check valve Network element valve Insertion chamber 4 Sealing ring WATER LOSS 2010 São Paulo 8

9 The idroloc injection system (2/2) Specific diffuser able to inject microscopic bubbles right into the water flow. Quick dissolution of Helium avoids previous problems. Helium is detectable for 5 days after injection up to 35 Km of inspection using one detector Wider scope of application, as gas dissolution is achieved even under low pressure conditions. WATER LOSS 2010 São Paulo 9

10 The idroloc detection system (1/2) Detection system 1. Suction rod 2. Suction cup 3. Pump & Filters (dust + humidity) 4. Portable Helium detector 5. PDA with built-in GPS 1 5 Weight ~ 4 Kg WATER LOSS 2010 São Paulo 10

11 The idroloc detection system (2/2) Helium detector based a new sensor: portable, sensitive and robust enough for the desired objective. Can be carried by one person (4 kg aprox.) with no need for external help The PDA records the results of the inspection along with the GPS position of the leaks The detection system can also be applied to leak detection in distribution networks or empty pipes WATER LOSS 2010 São Paulo 11

12 Dedicated software Helium level record Database output format Google Earth output format Time and position stamp Graph output Alarms Detector condition Detector control shortcuts WATER LOSS 2010 São Paulo 12

13 Cost and availability idroloc can either be acquired as a service or as a product Cost of the system (injection+detection): ~ (~ $) Training and technical support available WATER LOSS 2010 São Paulo 13

14 Leak detection for empty pipes Aplicable to New pipes Disconnected pipes Advantages: Replaces both watertightness test and leak location Fast to implement (specially in relation to others tests in large pipes) No unnecessary water consumption Sensitive, very precise WATER LOSS 2010 São Paulo 14

15 Results Success stories: Succesful leak detection in mains in Spain, France, China, Morocco, Saudi Arabia and Mexico since 2007 Singular case: sea water abstraction pipe of Alicante s desalination plant (Spain) Both the injection and detection systems of idroloc are covered by international patents WATER LOSS 2010 São Paulo 15

16 Summary Versatile, efficient detection system Can be applied in most situations: Transport mains Distribution networks Plastic pipes Low pressure Portable detector, easy to use Good performance cost relationship Gas injection improvement solves problems and increases the range of application WATER LOSS 2010 São Paulo 16

17 Thank you for your attention Muito Obrigado WATER LOSS 2010 São Paulo 17