Leak detectors for organic Rankine cycle power plants: on-line and manual methods

Technical Report · Mon Oct 01 04:00:00 EDT 1984

DOI:https://doi.org/10.2172/6203662· OSTI ID:6203662

Robertus, R J; Pool, K H; Kindle, C H; Sullivan, R G; Shannon, D W; Pierce, D D

Two leak detector systems have been designed, built, and tested at a binary-cycle (organic Rankine cycle) geothermal plant. One system is capable of detecting water in hydrocarbon streams down to 100 ppM liquid water in liquid isobutane. The unit first cools and/or condenses the hydrocarbon sample stream in a small heat exchanger. The cooled liquid stream flows to a large settling chamber where the water and isobutane separate because of density differences. Any water present is collected in a pipe and automatically dumped using a solenoid operated valve when the level reaches a certain point. The magnitude of the leak is estimated from the frequency at which the solenoid operated valve opens and closes, i.e. the amount of water collected in a known period of time is directly related to the number of dump cycles. The second system can detect the presence of isobutane in water or brine streams down to 2 ppM liquid isobutane in liquid water or brine. The unit first cools the liquid stream if necessary then reduces the pressure in an expansion chamber so the hydrocarbon will vaporize. In brine streams flashed CO/sub 2/ carries the hydrocarbon to a non-dispersive infrared analyzer (NDIR). (In cooling water streams a nitrogen carrier gas is used to transport the hydrocarbon to the analyzer). The NDIR has been modified to be highly selective for isobutane. One can estimate the size of a leak knowing the total gas-to-liquid ratio entering the leak detection system and the concentration of hydrocarbon in the gas phase. Four of the leak detector systems will be installed in the Heber Geothermal Demonstration Plant at Heber, California. Two will be on the hydrocarbon system, one on the brine system, and one on the cooling water system.

• Research Organization: Pacific Northwest Lab., Richland, WA (USA)
• DOE Contract Number: AC06-76RL01830
• OSTI ID: 6203662
• Report Number(s): PNL-5261; ON: DE85002792
• Country of Publication: United States
• Language: English

Related Subjects

15 GEOTHERMAL ENERGY
150802* -- Geothermal Power Plants-- Power Plant Systems & Components
2-METHYLPROPANE
ALKANES
BINARY-FLUID SYSTEMS
BRINES
ENERGY SYSTEMS
GEOTHERMAL FIELDS
GEOTHERMAL POWER PLANTS
Geothermal Legacy
HEBER GEOTHERMAL FIELD
HYDROCARBONS
LEAK DETECTORS
ORGANIC COMPOUNDS
POWER PLANTS
RANKINE CYCLE
THERMAL POWER PLANTS
THERMODYNAMIC CYCLES