HYDROGEN COOLED GENERATOR LUBRICANT DRAIN SYSTEM

PURPOSE: A lubricant drain system of a hydrogen-cooling generator is provided to maintain high hydrogen level in lubricant by allowing the lubricant drawn into a stand pipe to contact hydrogen gas in a detraining tank. CONSTITUTION: A lubricant drain system of a hydrogen-cooling generator comprises a hydrogen detraining tank(34) having a hollow inner part(42). A sensor(63) is installed in the hydrogen detraining tank to detect a boundary section(47) between lubricant and hydrogen gas in the hollow inner part. A drain line(50) is communicated with the hydrogen detraining tank to let fluid flow. The drain line comprises first and second end portions(52,53), wherein the first end portion is exposed on the hollow inner part. A valve(58) is installed in the drain line. A controller(70) is connected to the sensor and the valve to selectively open the valve. When the boundary section is located on the first end portion of the drain line, a fixed amount of lubricant is drawn out from the hollow inner part.