Helium mass spectrum leak detection fixture for tube plate welding seams of evaporator

Abstract

The invention provides a helium mass spectrum leak detection fixture for tube plate welding seams of an evaporator. The fixture comprises a gas cylinder, mobile cores, dynamic seal rings and a static seal ring, wherein the front end of the fixture is provided with an end face flange; the end face flange is provided with a seal groove; the static seal ring is arranged in the seal groove; a group of mobile cores are connected with the gas cylinder and can coaxially and synchronously do the telescopic movement together with the gas cylinder, so that the dynamic seal rings on the mobile cores arerespectively plugged up or taken off in a tube bundle hole on the surface of the tube plate of the evaporator at the same time; the end face flange and the back end of the main body of the fixture are in flexible connection by a corrugated tube; the static seal ring is tightly pressed by negative pressure generated by vacuum pumping; and the static seal ring and the seal groove both are curve-shaped according to the distribution of sealing welding seams on the surface of the tube plate and the condition of welding scars on the surface of the tube plate, and the dynamic seal rings are spindle-shaped. The fixture can quickly detect the welding quality of the sealing welding seams on the surfaces of a plurality of tube plates through the electropneumatic control over the gas cylinder and a leak detector by using an electronic control box.

Description

technical field [0001] The invention relates to a fast, high-efficiency, electro-pneumatic multi-core fixture for helium mass spectrometer leak detection on the welding point of the evaporator tube plate, and relates to the field of mechanical devices. Background technique [0002] The nuclear power evaporator is the key equipment of the nuclear power plant. Its main structure is composed of shell A, tube sheet B, tube bundle C and other components. There are multiple tube bundle holes D on the surface of the tube sheet B, and the multiple tube bundles C in the shell A are connected to the tube bundle holes D on the surface of the tube sheet B by welding. This process is called tube bundle-tube sheet sealing welding, and the weld is called sealing welding Weld E. (see figure 1 As shown), the welding quality of the sealing weld is crucial to the safe operation of the nuclear power plant. There are more than 9,000 to 20,000 sealing welds between the tube sheet and the tube b...

AI Technical Summary

Problems solved by technology

In the past, domestic manufacturers of nuclear power evaporators used manual operations to detect helium leaks on evaporators. They used O-rings to cover the bolts, and then manually inserted them into the holes one by one, and then tightened them carefully one by one. Nuts need to be loosened and pulled out one by one after the leak detection. With so many holes, it takes more than 10 people to spend a few days. The efficiency is extremely low, and more O-rings are consumed each time.

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