Date Published: April 28, 2016
Application: Equipment Monitoring
Manufacturer: Delphin Technology
Measurements: Pressure, Universal, Vibration
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Gas turbine efficiency is critical to a facility’s productivity. A global manufacturer of gas turbines uses Delphin Expert Vibro Data Acquisition & Control Systems for humming vibration analysis of data collected within turbine combustion chambers. Continual monitoring is required not only of conventional vibration data from bearings and shafts, but also of dynamic pressure vibrations.

The burning of gas, oil or fuel produces dynamic pressure vibration within furnace chambers and exhaust systems. This vibration is called ‘humming.’ The vibration’s frequency depends on the particular machine’s geometrical and process parameters. Humming is measured by high-temperature-resistant pressure sensors. The pressure vibration data contains information that is relevant to machine security and analysis, often indicating problems within plant and machinery such as damage or erosion which could eventually lead to a process shutdown.

Installation and Sensor Connection:

The Expert Vibro is easy to adapt to distributed control systems (DCS) by ProfiBus or Modbus. Its compact size allows users to easily install the device in a control cabinet or enclosure. Featuring 8 synchronous analog inputs for universal connection to sensors, the device samples at high speed (rates of up to 50kHz per channel). All channels are galvanically isolated.

The Expert Vibro also features 4 analog outputs and 8 digital outputs for monitoring; 4 digital inputs; and integrated comparators for Keyphasor® sensors enabling flexible triggering. The Expert Vibro’s 24-bit ADC converter allows for high-precision measurements. Users can check measurement data and configuration on the device’s touchscreen display.Vibration Monitoring with Delphin

In this application three high-temperature-resistant pressure sensors are installed within the furnace’s combustion chamber and connected to the Expert Vibro within a control cabinet located near the turbine. These sensors provide dynamic pressure vibrations which are then recorded by the Delphin Expert Vibro device onto its internal 32 GB/1 billion point memory.

Pressure Vibration Data Analysis:

The relevant information in humming signals can be isolated by signal analysis like FFT spectra. Delphin ProfiSignal analysis software performs this vibration analysis, visualization and automation. ProfiSignal is modular and scalable, allowing users to monitor measurement data on the fly with digital outputs able to switch within milliseconds in the event of limit value violations. Characteristic values or raw time signals from any of the analog inputs can be output to 2 analog outputs to interface with other equipment.

For this application users chose Delphin’s ProfiSignal Vibro option which provides a system that can detect vibrations in bearings and shafts as well as acquiring standard process data including pressures, temperatures, etc. The customer’s vibration data and process data is stored, analyzed and visualized using this single system. Time signal processing and characteristic curve computations take place directly within a DSP in the hardware.

The first step in analyzing the pressure vibration data is to perform FFT analysis on the pressure signal. An FFT spectrum enables users to determine and monitor narrow-band characteristic values (here the FFT are being monitored in a spectrogram diagram.) The Expert Vibro device immediately calculates the TRMS value for each frequency band. TRMS values undergo monitoring and in the event of an alarm, either messages are sent via ProfiBus to a main control system, or switching occurs at digital outputs.

Characteristic values and FFT spectrums are recorded to the Delphin device's internal data logger. Both online and archived data can be portrayed and analyzed at any time by just selecting the desired time range from the current visualization. Here the characteristic values are transferred via ProfiBus to the DCS. The operator can also create custom documentation using ProfiSignal’s report generator.

Vibration Monitoring Benefits:

Now the turbine manufacturer receives alarm indications whenever their own plant’s gas turbine bearings and shafts are at risk of damage. Without needing a host PC, the independent Delphin Expert Vibro system also monitors, measures and records the combustion chamber vibration data in real time. Vibration and process data can be viewed in this single system with fully-compatible hardware and software, unlike many other vibration monitoring systems at a higher cost.

Using the Vibro software option users are able to monitor and analyze the turbine vibration data and portray online and offline FFT (TRMS), cascade, time-signal and orbit diagrams. The Delphin can also be connected to control systems via PROFIBUS-DP or digital outputs.

Compact and inexpensive, the Delphin system is ideal for many different vibration monitoring applications including flue gas vibrations in gas turbines, flow vibration measurement in gas or liquid flows, monitoring of cavitation effects, and more. As Delphin’s North American master distributor, CAS DataLoggers can supply you with these cutting-edge data acquisition systems for any application.

Categories Related To This Application

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Products Related To This Application

Delphin Expert Vibro Vibration Monitoring System for acquiring transient signals and vibrations

Expert Vibro

Expert Vibro Data Acquisition System

  • 16 synchronous analog inputs, 50 kHz sampling rate per channel, IEPE, mV, mA sensors selectable via software
  • Dual-core FPGA processor based on ARM technology
  • Built-in FFT signal processing for characteristic values
  • Integrated comparators for KeyphasorŪ sensors
  • 32 GB data logger memory
  • 4 digital inputs for frequency measurement
  • 4 analog outputs for monitoring
  • 8 digital outputs