Water level detection method of heat transfer tube and inspection method of heat transfer tube

Abstract

The invention relates to a water level detection method for a heat transfer tube and an inspection method for the heat transfer tube. The water level detection method of heat transfer tubes detects the water levels of a plurality of heat transfer tubes extending below a header section extending in a horizontal direction, and includes a transmission step of transmitting ultrasonic waves upward on a lower surface of a maintenance tube holder. The method continuously transmits ultrasonic waves from the ultrasonic sensor, and the maintenance pipe holder is installed to protrude from the header part in the horizontal direction; the drainage start step starts drainage from the heat transfer tube and the header part; the drainage stop step starts from the When the ultrasonic sensor detects that the state of the reflected signal of ultrasonic waves changes to a state where no reflected signal of ultrasonic waves is detected, water drainage is stopped; and an opening step of opening at least part of the maintenance pipe holder after stopping.

Description

technical field [0001] The invention relates to a water level detection method of a heat transfer tube and an inspection method of the heat transfer tube. Background technique [0002] In order to perform wall thickness measurement and flaw detection inspection of heat transfer tubes (boiler tubes), there is a system in which an ultrasonic sensor is introduced from a header section to which a plurality of heat transfer tubes are connected to perform inspection. In inspection, since the heat transfer tubes to be inspected must be filled with water, water is supplied using a boiler water supply facility (for example, refer to Patent Document 1). [0003] When inspecting a plurality of heat transfer tubes connected to a header, the end of the target header is cut off and the ultrasonic sensor is introduced into the header. If the header is located near the upper side, water under pressure will be sprayed out when the header is cut off. Therefore, it is necessary to realize wa...

AI Technical Summary

Problems solved by technology

However, the technology described in Patent Document 2 is merely a means of detecting residual water in heat transfer tubes after complete drainage (dehydration)

In addition, even if this method is used, the heat transfer tubes connected to the target header part are covered with refractory material, and the ultrasonic sensor cannot be contacted unless the refractory material is removed. There is a problem of difficulty in working at high places without scaffolding

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