Boiler Tube Leak Detector
Overview
A boiler tube leak detector 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 boiler tube leak detector 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.
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
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.
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.
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) | |