In-situ gas leakage detection method for LY-type oil cooler of steam turbine

The invention belongs to the technical field of heat exchange tube bundle leakage detection, and particularly relates to an in-situ gas leakage detection device and method for a steam turbine LY type oil cooler, and the method comprises the following steps: S1, when oil is monitored to be contained in water side exhaust water, tube bundle breakage leakage occurs in the oil cooler, and shutdown maintenance is started; s2, an oil inlet pipe valve and an oil outlet pipe valve are closed, an oil outlet valve and an oil side exhaust valve are opened, and accumulated oil in an oil cooler is completely exhausted; s3, closing a water inlet pipe valve and a water outlet pipe valve, opening a drain valve to release pressure, and disassembling a water chamber seal head; and S4, the water level of the upper water chamber is adjusted to 10-20 mm, an oil side exhaust valve is closed, 0.1 MPa compressed air is introduced into an oil drain valve, a pipe bundle at the end of the upper water chamber is observed, obvious bubble