LNG mid-scale loop flow metering - preliminary test results

The LNG Mid-Scale Loop (MSL) has been taken into use in 2019. Instead of making use of surrogate fluids, the
facility will be able to perform calibrations with cryogenic liquid directly, and under actual operating conditions. Consequently, insight on surrogate-fluid calibration transferability will be obtained. The Cryogenic Research and Calibration facility allows for metrologically traceable cryogenic flow meter calibrations. At the time of writing, calibrations with liquid nitrogen (LiN) can be performed. By performing traceable calibrations with cryogenic liquids directly, market confidence in LNG custody transfer will be established which in turn allows the uptake of LNG on a larger scale. Notably, in addition to economic benefits of using LNG, the use of LNG as a transport fuel for trucks and ships has considerable environmental benefits. The Cryogenic Research and Calibration facility is based on a closed-loop system where cryogenic liquid is circulated. The cryogenic primary mass flow standard (PSL) is fully integrated into the facility. The target maximum flow rate of the facility is 200 m3/h. A metrologically traceable LNG composition primary standard allows to calibrate alternative composition measurement systems. Thus, the facility provides the means to traceably calibrate flow meter and composition measurement systems with cryogenic liquid directly, which in turn allows the calibration of systems for measuring the quantity of LNG-energy transferred. This article will describe the facility, it’s operating principles, preliminary test-results, and future plans. The facility allows for systematic research into flow meter performance in varied circumstances, such as the effects of flow-meter insulation, (upstream) flow disturbances, and multiphase flow. Prototypes and models of cryogenic flow meters can be tested and calibrated in a metrologically traceable manner.