US Patent No. 10,190,935

GAS LEAK DETECTION DEVICE AND GAS LEAK DETECTION METHOD


Patent No. 10,190,935
Issue Date January 29, 2019
Title Gas Leak Detection Device And Gas Leak Detection Method
Inventorship Hisao Inami, Tokyo (JP)
Makoto Hirose, Tokyo (JP)
Hiroyuki Nakamichi, Tokyo (JP)
Masaru Tatemi, Tokyo (JP)
Toshiaki Rokunohe, Tokyo (JP)
Assignee Hitachi, Ltd., Tokyo (JP)

Claim of US Patent No. 10,190,935

1. A gas leak detection device used for gas insulation electric equipment in which a conductor is installed inside a gas pressure container where insulating gas is sealed, and detects a leak of the insulating gas, comprising:a pressure sensor that measures a gas pressure value inside the gas pressure container;
a temperature sensor that measures an external temperature of the gas pressure container having a correlation with a gas temperature inside the gas pressure container, wherein the gas leak detection device corrects a gas pressure value measured by the pressure sensor to a gas pressure value of a reference temperature based on said external temperature measured by the temperature sensor and detects a leak of the insulating gas based on the corrected gas pressure value, and the gas leak detection device includes
a current data capturing section that captures a current value flowing in the conductor;
a collecting section including an A/D converter, the collecting section connected to the pressure sensor, the temperature sensor, and the current data capturing section to periodically collect data from the gas pressure sensor, the temperature sensor, and the current data capturing section;
a learning section, configured with a recording section, molar capacity and gas temperature calculation sections, and a gas temperature database, that obtains data written by the collecting section in a learning period, the learning section having a database with a correlation between a gas temperature inside the gas pressure container and an external temperature of the gas pressure container corresponding to the current value to make database in a learning period, and
a diagnosis section that extracts from the gas temperature database a gas temperature corresponding to the captured current value and said external temperature of the gas pressure container measured by the temperature sensor from the learning section in a diagnosis period, corrects the gas pressure value corresponding to the external temperature using the gas temperature corresponding to the captured current value to the gas pressure value of the reference temperature, and detects a leak of the insulating gas based on the corrected gas pressure value.