JPS62138693A - Detecting of leaking pipe - Google Patents

Abstract

PURPOSE:To increase the flow-out of gas or water from a leaking portion in a pipe and make leakage detection easier by pressurizing with air the inside of the cylindrical body of a condenser or a water room. CONSTITUTION:Water is filled in the cylindrical body 1 of a condenser, and, further, air is introduced into the cylindrical body to pressurize it, using a compressor 14. An inspector 7 visually observes whether or not water is flowing out from the ends of a cooling pipe in a water room 3 to locate the position of a leaking pipe. When it is difficult to judge that there is leakage because a leaking portion is extremely small, the amount of water flowing into the cooling pipe is increased by increasing the discharge pressure of the compressor 14 for making it easy to detect leakage. And The air source of high pressure such as the compressor 14, etc. is generally provided in the facilities of a power generation plant, so that the carrying in of an air source of high pressure for the leakage test is not required.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention determines leakage pipes in a shell-and-tube heat exchanger, particularly a condenser for a steam turbine. This invention relates to a leakage pipe detection method.

[Background of the invention]

In general, the method for detecting leakage pipes in condensers, etc. is that in two-section condensers, the ice chamber on the leakage pipe side is released while maintaining vacuum by one-lung operation, and a vinyl sheet or wrap is placed on the tube plate surface to detect the leakage pipe. However, since the above method is not possible in segmented condensers, etc., the water filling method is applied. Also.

The method for detecting leakage pipes during periodic inspections that are performed with printing stopped is the water filling method, since detection using a vacuum in one-lung operation is impossible even in a two-section condenser.

Examples of the conventional water filling method are shown in FIGS. 7 and 8. FIG. 7 is a diagram in which an inspector 7 detects a leakage pipe in the cooling pipe 2 in the condenser water chamber 3 after filling the body 1 of the condenser with water 6. . That is, the inspector 7 visually observes that water flows from the leakage portion into the cooling pipes and flows out from the ends of the cooling pipes. However, with this method, if the leakage part is minute, the amount of water flowing into the cooling pipe is small, and the inspection takes time, and the leakage pipe cannot be detected unless the inspector carefully inspects the solid cooling pipe. There was a drawback that there was no

The insides of water chambers 3 and 4 are generally filled with a large number of marine creatures, and there is a risk that toxic sulfide gas will be generated from their carcasses, so inspectors 7 should not remain in the water chambers for long periods of time. I can't.

FIG. 8 shows that the water chambers 3 and 4 are filled with water, and the inside of the condenser body is evacuated using the installed vacuum pump 12 for air removal.
A method of detecting a leaking pipe is shown by observing the change in the pressure 13 inside the body when the water level 11 is changed. That is, the ninth
As shown in Figure 10, the water level 11 (11', 11
') is changed from A to B-+C by controlling the cooling water inlet valve 8 shown in FIG. The pressure 13 inside the condenser body 1 is low at the water surface level A, and when the water level reaches the position of the cooling pipe leakage part 2' (water surface level B),
Air flows into the condenser body from the leakage part, so the pressure is 13
will rise. By using this method, the leak pipe position can be detected in a short time. However, this method has the disadvantage that it takes a lot of time and money to create a vacuum inside the condenser body. Furthermore, if the leakage portion is minute, it is difficult to detect.

Furthermore, as a method for detecting leaks at pipe expansion parts and pipe seal welds, see Thermal Power Generation Vo 115. NOI O(Oc
A method using soapy water foaming at the end of a tube was used, as shown in J. T., 1964), but with this method it was not possible to detect leaks from the center of the tube.

Another leak detection method is to introduce an ultrasonic flaw detection probe or an eddy current flaw detection probe into the pipes, but this method inspects all 5,000 to 10,000 condenser cooling pipes one by one. It is necessary and requires a lot of time. Furthermore, if the leakage portion is minute, it may not be possible to detect it, making it less practical.

[Purpose of the invention]

An object of the present invention is to provide a leakage pipe detection method that can easily and quickly detect leakage pipes in a condenser or the like.

[Summary of the invention]

When detecting leakage pipes by filling the body or water chamber of a condenser or the like with water or gas, the present invention can prevent water or gas from leaking by pressurizing the body or water chamber with air. It is characterized by increasing the outflow of and making detection easy.

[Embodiments of the invention]

Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

FIG. 1 shows a first embodiment using the leakage pipe detection method of the present invention. The condenser body 1 is filled with water, and a compressor 14 is used to introduce air into the body and pressurize it.

The inspector 7 visually observes the presence or absence of water flowing out from the ends of the cooling pipes in the water chamber 3 to detect the position of the leakage pipe. If it is difficult to identify the leakage pipe because the leakage part is so small, increasing the discharge pressure of the compressor 14 can increase the amount of water flowing into the cooling pipe, making detection easier. .

In addition, the high-pressure air source such as the compressor 14 is generally permanently installed equipment in power generation plant equipment, and there is no need to carry it in from another place for this test.

Using the method described above, remove leakage pipes from condensers, etc.

It can be easily detected.

FIG. 2 shows a second embodiment using the method of the invention. The file generated in the smoke generator 15 is introduced into the condenser body 1 and filled into the spacer. Here, compressor 1
, 4, air is introduced into the fuselage and the interior of the fuselage is pressurized. By this operation, smoke flows into the cooling pipe from the leakage part of the cooling pipe, passes through the ends of the cooling pipe, and is discharged into the water chamber. The inspector 7 can detect a leaking pipe by visually observing the smoke outlet inside the water chamber. According to these methods.

The location of leakage pipes such as condensers can be detected in a short time by visual observation.

FIG. 3 shows a third embodiment of the method of the invention. Gas is introduced from the cylinder 17 into the condenser body, and gas 18 is filled into the body. Here, air is introduced into the fuselage by the compressor 14 to pressurize the interior of the fuselage. By this operation, a mixture of gas and air flows into the cooling pipe from the leakage part of the cooling pipe, passes through the ends of the cooling pipe, and is discharged into the water chamber. Inside the water chamber, the inspector 7 uses a gas detector (or concentration meter) to determine leakage pipes. According to such a method, the position of a leak pipe such as a condenser can be detected accurately and in a short time using a gas detector (or concentration meter).

Another method is to apply a soap film to the ends of the cooling pipes to detect leakage pipes.

FIG. 4 shows a fourth embodiment of the method of the invention. The water chambers 3 and 4 are filled with water, and air is introduced from the top of the ice chamber using a compressor 14 to pressurize the water chambers.

Furthermore, as shown in Figures 5 and 6, the water level 11 (11'
, 11''') is changed from A-+B to C by controlling the cooling water inlet valve 8 shown in FIG.
When the water level reaches position '' (water surface level B), air flows into the condenser body from the leakage part, so the pressure 19 decreases. At this time, the fuselage inspection port 20 is opened.

With this method, the leak pipe position can be detected in a short time. Further, the amount of compressed air used for this test can be small because only the inside of the water chamber is pressurized, and the test time can be shortened accordingly.

〔Effect of the invention〕

According to the present invention, a leak pipe detection method can be performed easily in a short time and more reliable than conventional methods.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of a first embodiment using the leakage pipe detection method of the present invention, FIG. 2 is an explanatory diagram of the second embodiment, and FIG.
The figure is also an explanatory diagram of the third embodiment, and FIG.
FIG. 5 is a detailed explanatory diagram of FIG. 4, and FIG.
The figure is a pressure change diagram in the condenser water chamber, Figure 7 is an explanatory diagram of the conventional leak pipe detection method ■, and Figure 8 is the conventional leak pipe detection method ■
FIG. 9 is a detailed explanatory diagram of FIG. 8, and FIG. 10 is a diagram of pressure changes in the condenser body. 1... Condenser body, 2... Cooling pipe, 3... Inlet ice chamber, 4... Outlet ice chamber, 5... Lifting pump, 6...
Water surface inside the fuselage, 7... Inspection amount, 8... Cooling water population valve,
9...Cooling water outlet valve, 10...Ice chamber inspection port, 11.
...Water level in the ice chamber, 12...Vacuum pump, 13...Pressure gauge in the fuselage, 14...Compressor, 15...
・Smoke generator, 16...Smoke.

Claims (1)

[Claims] 1. In a multi-tube heat exchanger, the body or water chamber is filled with fluid such as water or gas, and compressed air is introduced into the body or water chamber to pressurize it and leak from the cooling pipe leak into the cooling pipe. A leakage pipe detection method characterized by promoting fluid flow.