H₂ Cooled Generator Gas Monitoring System Upgrade: More Than a Dryer

Hydrogen cooled generators have utilized dryers since 1935 to keep the generator cooling gas dry. The dryer and auxiliary skid of 2008 can do much more and can be an effective tool in managing and monitoring the generator gas system. SIPC (Southern Illinois Power Cooperative) started with the original OEM single tower dryer. Three changes in the new skids are noteworthy. The dual tower dryers we have now are automatic and provide drying continuously including turning gear operation without gas purging or venting. The dryers also continuously provide information on the gas dew point in the generator at operating pressure as well as documenting the dryer performance. The newest skid also includes a water discharge monitoring system that measures the water removed from the generator. This information has been very helpful in detecting potential problems or changes in the water infiltration rates which can be one of the earliest indicators of a serious problem. The last significant addition to the dryer skid is the purity monitoring system, which is scheduled to be installed shortly. It is fully integrated into the dryer skid and information is supplied on the operator interface of the control panel. All the pertinent information including alarms, dew points, water discharge and purity is available to the control room and can be trended on the plant DCS system. The plant experiences and benefits of the new drying skid will be fully detailed in this presentation.