JPS5878000A - Inspection of pipe network - Google Patents

Abstract

PURPOSE:To make it possible to detect a choked pipe from among the pipe network by a method wherein hot water is supplied into the pipe network and the distribution of temperature at the wall of each of the pipes of the pipe network is measured by an infrared ray camera. CONSTITUTION:When hot water is supplied instantaneously into the pipe network B comprising a plurality of cooling pipes, by opening and closing electromagnetic valves 8 and 9, the temperature of the wall of each of the cooling pipes which has been equal to the ambient temperature rises up to become close to the temperature of the hot water. In this case, the temperature of each of the cooling pipes is slower to rise when the pipe is choked than when it is not choked so that an uneven temperature distribution takes place through the walls of the pipes of the pipe network B in the direction of the row thereof and such uneven temperature distribution is measured by the infrared ray camera.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a pipeline network consisting of a plurality of pipelines arranged in parallel with each other, and to This invention relates to a pipe network inspection method that can detect

Until now, there have been few concrete examples of the use of this type of pipe network inspection method. Possible methods include sipping and testing based on neutron photography, but the former is expensive and often structurally impossible, while the latter is complicated to operate and is not suitable for on-site inspection. There are many cases where this is inappropriate, and in either case it is impractical.

In view of the above points, the present invention has been made to improve the health of the pipeline network.
- It is an object of the present invention to provide a method for inspecting a pipe network by which the presence or absence of blocked pipes can be determined by a simple means.

For this reason, in the present invention, when detecting a blocked pipe among the plurality of pipes with respect to a pipe network consisting of a plurality of pipes arranged in parallel with each other, first, hot water is supplied to the pipe network. The present invention is characterized in that the above-mentioned blocked conduit is detected by supplying water and then measuring the temperature distribution of the wall portion of each of the above-mentioned conduits with an infrared camera.

Hereinafter, a method for inspecting a pipeline network as an embodiment of the present invention will be explained with reference to the drawings. Figure 1 is a schematic diagram showing an apparatus for carrying out the method, and Figure 2 is a diagram showing a pipeline network with a high temperature duct. FIG. 3(a) is a schematic diagram showing an example of implementing the present method for.

(b) is a graph for explaining the effect.

As shown in Fig. 1, there is a tank 1, a pump 2, a flow control valve 3. Heater 5. Flow meter7. A hot water circulation system A consisting of a solenoid valve 8, a circulation pipe 10, etc. is provided, and hot water is circulated within this hot water circulation system A.

At this time, the water temperature and water flow are set constant by the temperature regulator 6 and the flow rate control valve 3.

The hot water circulation system A has an outlet pipe 19 branched from a pipe section between the flow meter 7 and the solenoid valve 8, and the solenoid valve 9 is interposed in the outlet pipe 19.

In order to inspect the pipeline network B, the pipeline network B to be inspected may be connected to the outlet pipe 19. The pipe network B in this embodiment is configured as a cooling pipe network, and includes a plurality of cooling pipes 13 arranged in parallel with each other, and pipes attached to the ends of these cooling pipes 13. With header 12, 1
Connected to the outlet pipe 19 is a header 12 constructed as one unit. Usually, a cooling water supply system (not shown) is connected to the header 12.

In addition, in order to continuously measure the wall temperature distribution of the cooling pipe line 13,
An infrared camera 15 is installed, and this infrared camera 15 includes a monitor TV I6 for displaying the temperature distribution on one screen and a V for continuously recording the temperature distribution state.
A recording device 17 such as a TR (video tape recorder) is attached.

In FIG. 1, reference numeral 4 indicates a valve, 11 indicates a water supply pipe into the tank 1, and 14 indicates a tank that receives hot water discharged from the header at the bottom of the figure during inspection.

With the above configuration, for the pipeline network B, a plurality of pipelines 13
To detect a blocked pipe (including a partially blocked pipe), first connect the pipe network B to the outlet pipe 19, and then close the solenoid valve 8 at the same time. open.

As a result, hot water at a constant temperature and constant flow rate from the hot water circulation system A is supplied to the pipe network B instantaneously, that is, in a stepwise manner.

As a result, a temperature distribution corresponding to the distribution of the flow rate to each cooling pipe line 13 occurs on the pipe wall portion.

In other words, when hot water is instantaneously passed through the pipe network B by opening and closing the solenoid valves 8 and 9, the cooling pipe wall temperature, which was previously equal to the ambient temperature, rises to approach the hot water temperature, but the rate of increase is Among the cooling pipes 13, the temperature is slower in blocked or slightly blocked cooling pipes than in healthy cooling pipes, so that an uneven temperature distribution occurs on the pipe wall in the direction of the pipe row. This temperature distribution is continuously measured by the infrared camera 15.

In this case, the measurement by the infrared camera 15
This has been done continuously since before the hot water was supplied to No. 3.

In this way, by measuring the temperature distribution of the pipe wall portion with the infrared camera 15, a blocked cooling pipe path (occluded pipe line) can be detected.

In addition, Fig. 3(a) shows the relationship between the dimensionless temperature O and the number of blocked pipes N.
It is a graph showing the relationship between t and t as hot water passage elapsed time parameters.

Here, the dimensionless temperature θ is defined as follows.

Note that θ1 is the tube wall temperature, θ8 is the ambient temperature, and θ0 is the hot water temperature.

In addition, in FIG. 3(a), the symbol Δθ is 2 after hot water is supplied.
The figure shows the difference in dimensionless temperature between the number of blocked pipes being 1 and O when seconds have elapsed.

Now, for example, when the number of blocked pipes is 1, if we look at this when 2 seconds have passed after the hot water has passed, it can be seen from Fig. 3(a) that θ is 062, so the hot water temperature θ. is 60
℃, and the ambient temperature θ8 is 20℃, the tube wall temperature θY is calculated as 448℃ from equation (1),
Therefore, the number of blocked pipes can be estimated from the value of this temperature θ1.

It goes without saying that such measurement of the number of blocked pipes can be carried out in the same manner at any hot water temperature, any ambient temperature, and any elapsed time of hot water supply.

Note that FIG. 1(b) shows a graph corresponding to FIG. 3(a) when hot water is supplied in an exponential manner.
In this way, even when hot water is supplied in an exponential manner, it is possible to measure the number of blocked pipes.

Here, as an example of supplying hot water in an exponential manner,
A case may be considered in which a manual valve is used instead of the solenoid valve 90.

In other words, when the valve is turned by hand to open it, the time characteristics of the hot water supplied become exponential.

By the way, as shown in Fig. 2, regarding the pipe network B installed in the high temperature duct 18 through which high-temperature gas such as combustion gas flows in order to adjust the temperature by water spray, one of the many pipes 13 was installed at the site. It is also possible to detect occluded ducts. In FIG. 2, the same reference numerals as in FIG. 1 indicate substantially the same parts, and the parts not shown in FIG. 2 are substantially the same as in FIG. 1.

As described in detail above, the pipe network inspection method of the present invention has the advantage that blocked pipes can be reliably detected with simple operations.

[Brief explanation of the drawing]

The figures show a method for inspecting a pipeline network as an embodiment of the present invention. Figure 1 is a schematic diagram showing an apparatus for carrying out the method, and Figure 2 is a diagram of a pipeline network with a high temperature duct. Schematic diagram showing an example of implementing this method, FIG. 3(a), (
b) are graphs for explaining the effects. lll11 tank, 211 @pump, 311+1 flow control valve, 4...valve, 5...heater, 6...temperature regulator,
7.Flowmeter, 8,9.Solenoid valve, 10.Circulation pipe, 1
1. Water supply pipe, 12. Header, 13. Cooling pipe line, 14. Tank, 15. Infrared camera, 16. Monitor TV, 17. Recording device, 18. High temperature duct.
19(0) Ol 3 7 Figure 3(b) OI 3 7

Claims (1)

[Claims] Regarding a pipeline network consisting of a plurality of pipelines arranged in parallel with each other, when detecting a blocked pipeline among the plurality of pipelines, hot water is first supplied to the pipeline network, and then the above-mentioned A method for inspecting a pipe network, characterized in that the blocked pipe is detected by measuring the temperature distribution of the wall of each pipe with a red bath camera.