JPS5895239A - Monitoring device for leakage of valve - Google Patents

Abstract

PURPOSE:To precisely detect a value for leakage, by providing a drain storing part with a cylindrical tube having many small holes in the vertical and circumferential directions and providing a measuring device for measuring differential pressure signals of the values of water level collected in the cylindrical tube to the storing part. CONSTITUTION:A value leakage monitoring device 13 is attached on the way of a steam exhausting tube 11. A drain storing part 14 of the monitoring device 13 is provided with a cylindrical tube having many small holes in the vertical and circumferential directions and dew condensed water is collected according to the drain water level e.g. at a low water level in case of the small quantity of dew water and at a high water level in case of large quantity until inflow drain water level is balanced with drained volume from these small holes. Thus the water level in the storing part 14 is measured by a liquid level meter 17, so that valve leakage can be detected. Consequently steam leakage is precisely detected independently of the heat conduction of atmospheric temperature around the valve.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field of the Invention) The present invention relates to a device C for monitoring leakage of a valve in a steam pipe in, for example, a boiling water nuclear reactor or the like.

(Technical Background of the Invention) For example, in a boiling water nuclear reactor, high-temperature, high-pressure steam generated in a reactor pressure vessel containing a reactor core is sent to a power generation turbine or the like through a main steam pipe to generate power. By the way, this main steam pipe C2 is used to protect the reactor pressure vessel or the main steam pipe, etc., in the event of an abnormal accident.
: A safety valve is installed to prevent equipment etc. from being damaged due to excessive pressure rise. However, this safety valve may generate minute steam/leakage at C2 due to failure of the valve seat or valve body, or when the pressure rises close to the valve operating pressure. For this reason, conventionally, a temperature detector is attached to the discharge side of the safety valve as a steam leakage monitoring device, and steam leakage is detected by detecting a temperature rise due to the steam leakage 52.

(One point between conventional technologies) However, leakage monitoring devices that use such temperature detectors have the disadvantage of lacking reliability because they are affected by the ambient air temperature around the safety valve and heat conduction from other sources. ,
Moreover, due to its nature, it had the disadvantage that it was not possible to quantitatively measure the leakage lid.Furthermore, it was necessary to use a C2 vertical cage to withstand the falcon when the valve was activated, sacrificing measurement accuracy to some extent ( I had no choice but to do so.

(Object of the present invention) This invention was made based on the above-mentioned circumstances (2), and its purpose is to provide a valve leakage monitoring device that can constant-electrically and reliably monitor the presence or absence of valve leakage. It is in.

(S composition of the invention) That is, the present invention provides a drain storage part for collecting the condensed water of the steam leaking from the tank in the middle of the discharge at W path of the valve, and the amount of water flowing into the drain storage part W2 is In the valve leakage monitoring device C2, which is equipped with a constant-electrical drain water metering mechanism, the drain storage section serving as the drain water metering mechanism has a large number of small holes in the vertical and circumferential directions. By providing a cylindrical pipe, the water head value accumulated in this cylindrical pipe changes according to the amount of drain water, so it is possible to quantitatively and continuously detect this differential pressure (?1) by measuring this difference. This is a valve leak monitoring device that detects leakage.

(Embodiment of the present invention) The present invention will be described below based on an illustrative embodiment. In the figure, reference numeral 1 indicates a reactor pressure vessel of a boiling water reactor, and a reactor core 2 and other reactor constituent members (not shown) are accommodated within this pressure vessel 1. Water as a coolant AVi in the pressure vessel 1, and this coolant A
is heated by the reactor core 2, boils, and becomes high-temperature, high-pressure steam, which is then fed to a power generation turbine (not shown) through a steam distribution pipe W3. Note that 4 indicates a heat insulating material for keeping the live steam pipe 3 warm, and 5 indicates a main steam isolation valve. Further, numeral 6 denotes each reactor containment magazine, 7 a partition floor, and a suppression pool 8 for steam cooling is provided below the partition floor 7.

Further, a safety valve 10 is provided in the middle of the main steam pipe 3, which is opened when an abnormal accident occurs. A steam exhaust pipe 11 is connected to the exhaust port 0IIIi of this safety valve IO, and a sparger 12 having a large number of small holes 12a is attached to the tip end of the steam exhaust pipe 11. is submerged in

A valve leakage monitoring device i13 according to the present invention is provided in the middle of this steam exhaust pipe 11. The fraud of this monitoring device [13] will be explained below. That is, the reference numeral 14 denotes a container-shaped drain storage section through which a drain entry pipe passes, and this storage section 14 is a cylindrical tube having a large number of small holes in the vertical and circumferential directions. 16. The steam discharge pipe 11 is delayed.

The drain inlet pipe 15 is opened at a position where the condensed water can naturally flow into the upper inner wall of the steam discharge pipe II. level gauge, its signal is the valve leakage monitoring device f
ii 13.

(Actions of the present invention) Next, two effects C of the above-mentioned formation will be explained. The coolant A heated and boiled in the reactor core 2g becomes steam, passes through the live steam pipe 3, and is sent to a power generation turbine, etc., which are not illustrated. The safety valve IO is normally closed, but opens when an abnormal pressure rise occurs, and the steam in the live steam pipe 3 and pressure vessel 1 is evenly distributed into the suppression pool 8 through the sparger 12. It is discharged, where it is cooled and turned into water.

By the way, a small amount of steam leakage may occur in the upper te safety valve 10 if the internal valve seat or valve body fails or if the pressure rises to near the valve operating pressure.

At this time, a small amount of water vapor flows into the steam exhaust pipe 11 through the safety valve 10, but since the steam exhaust pipe 11 is not kept warm and is in a relatively low temperature state, the water vapor turns into condensed water here. The drain flows into the drain flow path 15 and flows toward the drain storage section 14 (1.
is a cylindrical pipe with a large number of small holes, and the diameter of the lower hole is small and the number of holes is small (they are arranged vertically and circumferentially, so that the drain water can be drained according to the amount of water f). If there is less, the water level will be lower, and if there is more, the water level will be higher.The condensed water accumulates in the drain storage part 14C until the amount of drain water flowing in and the discharge chamber from this small hole are balanced.Then, the balanced water level in the storage part 14 is measured by a liquid level meter.・By measuring at step 17, the leakage amount of the valve can be known from the pre-calibrated liquid level-flow ii1% relationship.

(Effects of the present invention) Accordingly, the apparatus C-twist of the above embodiment detects the amount of drain water that has flowed into the storage section 14 as described above (C2). Quantitative quantity 5
Since the leakage state of the safety valve IO can be detected with certainty. Moreover, a large example of drain water meter trip 1
By measuring the balanced water level of the 8fl storage section 14, the drain inflow current per unit time can be accurately and continuously measured with a simple configuration.

In addition, drain water injection heavy equipment wF 1 view 1 Nidrain storage part 1
It is sufficient that drain water can be quantitatively detected by measuring the water level in a balance between the amount of water flowing into C2 and the violet discharged from the storage part, so various changes can be made without being limited to this example ≦2. It can be implemented by Further, the present invention is not limited to the safety valve C1, but can be similarly applied to ordinary on-off valves and the like.

As explained above, the present invention provides a drain for collecting condensed water from the steam leaking from the valve in the middle of the discharge side pipe of the valve, and the amount of water flowing into this storage part is quantified by the drain water injection mechanism. This is a device that monitors leakage steam from a valve by detecting it directly.

Therefore, according to the present invention, 1) leakage steam can be accurately detected without being affected by the ambient air temperature around the C1 valve or heat conduction from other parts, unlike conventional leakage monitoring devices using temperature detectors. Ru. Moreover, since the leakage lid can be measured quantitatively, the degree of leakage can be quantitatively grasped, and even a slight leakage can be reliably detected.
can be installed at a sufficient distance from the valve,
It is possible to prevent the impact when the valve is activated from acting on the drain water meter, etc., and therefore high accuracy can be maintained without a particularly robust structure.

As described above, according to the present invention i.2, it is possible to provide a leak monitoring device that is highly reliable and has a high total accuracy of 1 ull. For example, when used in a nuclear power plant, f2 can improve the safety of the entire plant.

[Brief explanation of the drawing]

The drawing is a diagram diagrammatically showing an embodiment of the present invention. lO... Valve (safety valve) 11... Steam exhaust pipe 1
3...Valve leakage monitoring device 14...Drain storage section 1
5...Drain inflow pipe 17...Liquid level gauge 18...
Drain water metering mechanism

Claims (1)

[Claims] In the middle of the pipe on the discharge side of the valve, there is provided a drain part I: to collect condensed water from the steam leaking from the valve, and the drain part C is a drain water metering part which regularly detects the amount of water flowing in. A leakage monitoring device for a valve equipped with a mechanism≦2, the drain storage part I as the drain water meter i1 mechanism: a cylindrical pipe having a large number of small holes in the vertical and circumferential directions C is provided.
Two cylindrical pipes with the same number - A valve leakage monitoring device O characterized by comprising a leakage measuring device that measures the differential pressure signal of the accumulated water value.