LMS 18.3.2 Deployed at LNG Site in Virginia

December 2022

MHT Technology’s LMS 18.3.2 software was deployed at the TC Energy site in Chesapeake, Virginia in December 2022. The deployment took place as part of an upgrade of their software and included the scheduled rollover feature and the new associated automatic composition facility.

TC Energy were already using 18.2.5 to monitor the stratification of their LNG storage tank, but decided to upgrade their software following a training program on the subject of LNG Rollover. The peak shaving plant in Chesapeake stores excess natural gas during the summer months when demand is low, to provide back to the national grid in the winter. In the change over from exporting to importing gas the tank contents can weather to leave a dense heel in the tank, setting up the conditions for stratification and eventual rollover.

ROLLOVER Protection

The automation starts with a scheduled profile of the tank. The Scientific Instruments 6290 gauge is sent a command by LMS to do a full profile of the tank contents. The second stage of the analysis takes place after the profile is completed; a rollover calculation takes the last 2 profiles and analyses them for stratification. If both are stratified the system is then able to compute the rate of change between the two and estimate from that, the time taken for the stratification to break down and result in a rollover event.