Tube Leak Monitor

Control Systems

Overview

A tube leak monitor can discover high-pressure steam or water leaks caused by rupture of a boiler furnace water wall, super-heater, or reheat combustor at an early stage to keep damage to the customer's boiler to a minimum.

Features

Detection of Tiny Leaks

A tube leak monitor continuously monitors for tube leaks and can immediately detect leaks that cannot be heard on-site by patrol personnel.

Reducing Boiler Downtime and Repair Expense

By keeping damage to the tube caused by ruptures to a minimum, you can reduce boiler downtime and repair expense.

Enabling Appropriate Decisions on Downtime

By monitoring the trend of the leak when it occurs, you can make an appropriate decision about the downtime of the unit.

Support for a Variety of Fuel Boilers and Easy Installation

Various types of fuel boilers are supported, and installing a detector to a boiler is easy.
The guidelines for the number of sensors to be installed are as follows (Note).

  • Consultation may be required to decide the exact number.
Uses Qty
Electric utility About 10 - 20
Industry About 10 or less

Principle

If the boiler pressure vessel fails and a high-pressure steam or water leak occurs, abnormal noise is generated at or around the rupture. The frequency curve of this noise is different from that of the background noise generated by combustion in the furnace or by the spraying of fuel in the burner. The background noise generally has more power at lower frequencies. Higher frequency noise is generated by high-pressure leaking at ruptures.

Pressure vessel leaks can be detected by monitoring for this higher frequency component.

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The leak detection capability is affected by the following factors:
The level of background noise depends on the structure of the boiler and the positioning of the sensors.
The level of leak noise depends on the direction or angle of the ejected spray as well as the whether or not the spray strikes anything.

Air Pressure 140kg/cm2
Nozzle Diameter 2.0mm
Distance to Sensor About 10m

System Configuration

Basic System Configuration

 

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Sound Detection Monitor Unit

This unit enables remote articulation of noise in the boiler furnace and leak noise.

FFT Unit

This unit is used for frequency analysis of the signals from the amplifiers. (FFT: Fast Fourier Transform)

Computer System

The output from each sensor is logged, monitored, and compared with the set background value. This unit generates alarms and displays the status on a monitor.

Monitoring Panel

This unit can process the signals from a maximum of 30 sensors. It generates alarms and displays the status. It should be placed in a computer room or similar location.

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Monitoring Panel

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Monitoring Screen

Sensors

A sensor consists of a sound pipe and an acoustic sensor. Depending on the structure of the boiler, about 20 sensors are installed evenly on the furnace wall and the flue in order to monitor the whole boiler.

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Specifications

Sensor (F-115)

The specifications of the sensor (F-115) are as follows.

Series Omnidirectional dynamic microphone
Operating Temperature Range -20℃ to 60℃ (non-cooling type)
Signal Cable NVVS (S) 2.0/ 2C×500m (max.)
Sound Pipe 50A straight pipe (standard size)
Electromagnetic Valve AC/DC-compatible (adapted to match customer specifications)
Purge Air Air Flow About 450Nl/min per sensor (during purge only)
Temperature Max. 40℃

Monitoring Panel

The specifications of the sensor monitoring panel are as follows.

Series Self standing sealed type with access hatches on both surfaces
Dimensions (Standard Type) 2,300mm (H) ×800mm (W) ×800mm (D)
Operating temperature range 0 to 40℃
Amplifier /
Relay Unit
(ARU-100)
Input Channels 30 ch (max.)
Output Channels 1ch
Power Supply DC24V±10%
FFT Unit
(CF-4210A)
Input Channels 30 ch (max.)
Frequency Range DC up to 20kHz
Power Supply AC90 to 264V (50/60Hz)
Computer Unit CPU Pentium III
OS Windows NT4.0
Power Supply AC85 to 132V (50/60Hz)
CRT 15Inches (Color)