Turbine Blading Accidents Prevention Automatical System (BAPAS)

   BAPAS is an automatical system, worked out and supplied by Central Boiler and Turbine Research Institute (CKTI) and designed to avert the dangerous breakdown of turbines caused by eventual damages of rotational blades.
   It is well known that accidents of this kind usually lead to severe damages of turbine equipment, ending with long reparation periods with subsequent perceptible financial losses.
   This shows the extraordinary actual character of the tasks solved by BAPAS especially while dealing with the equipment operating for a long duration.

1. The purpose of the BAPAS.

The automatical complex BAPAS is designed to fulfill following tasks:
 uninterrupted control of the mechanical state of every blade in supervised stages (last one) during the rotating of rotors in the whole process of turbine operation
 timely revealing of the blading damages:

• dangerous cracks in blades
• ruptures of lashing damping wires
• separation of blades tips
• breaking of peripheral bandages
• timely warning of turbine operators concerning detected damages with description of damage and indication of corresponding stage and blade number.

2. Working principles (methodological base)

   The theoretical base of the system is a unique method of blading mechanical state evaluation patented by CKTI (patent # 2008438C1). The method is a subject of know-how which is to be provided for the customer for agreed conditions.
   The way of implementation of diagnostical method consists in installation of special contactless pick-ups ( 2-4 pieces) over the supervised stage blade row. The diagnostical conclusion is made after processing the signal taken from the pick-ups. The acquisition, processing and analyzing of the signals ( synchronized by reference proximity gauge) are being done constantly during the operation of the turbine in order to deliver a real-time information on the blading behavior.
   The reliability of analysis algorithm and trustworthiness of delivered information are proved by numerous theoretical and experimental researches. The system was thoroughly tested at CKTI model installations and on real operating turbine K-300-240 LMZ at Kirishi Power Plant ( St-Petersburg region).

3. Main technical characteristics of the BAPAS

• number of controlled stages - up to 8
• number of blade of controlled stages - up to 110
• speed of shaft rotation - 500ё9000 rpm
• standard hardware - IBM PC
• operational system - Windows 95/98/NT
• feeding voltage - 220 V
• consumed capacity - up to 400 Wt

4. Structure of BAPAS hardware

 information channel

• sensor (pick-up)
• comparator
• feeding device ( if required)

 capacity measuring device ( if required)
 PC-based controller

• processing unit
• special BAPAS plates (cards)
• local alarm shield
• integrated device for connection of BAPAS hardware and control room alarm channels (if required)

 cables

The PC configuration :

• processor on 333 MHz
• HDD not less then 4,3 GB
• RAM 64 Mb
• FDD 3,5 І
• CD-ROM
• network card
• keyboard
• mouse
• SVGA monitor

5. BAPAS software

The software is organized in operational system Microsoft Windows 95/98/NT and consist of two program sets:

• BAPAS - monitoring for delivering actual real-time data
• BAPAS - archive for reviewing memorized data The BAPAS software assures:
• automatical collection of information corresponding to mechanical state of blading during turbine operation
• processing and displaying the information acquired in the form convenient to the User ( charts, tables, info messages)
• identification of blading damages and delivering alarm warnings
• memorizing and delivering of archived information, organizing the blackbox service with identification off all important events and their location
• self-testing of hardware
        The BAPAS software is user-friendly organized, easily managed and open for the authorized persons.
        The work with archive is possible not only within the BAPAS software but any Microsoft shell supporting data base of the SQL type.
        The software may be integrated with computer network ( BAPAS network version) with the server supporting up to three users simultaneously.

6. Lay-out of the BAPAS at site

• pick-ups (inductive sensors) are installed in the turbine flow path over supervised stage(s)
• one sensor is installed at convenient place over the shaft ( contactless) serving as reference synchronizing gauge
• the comparators are fixed on the outer case of the turbine
• the terminal hardware is installed in the control room.
  
  Note. The installation of sensors and their cabling may be executed while the LP turbine is opened.

7. Reference-list

The BAPAS device of the first generation is functioning on the turbines:

• T-110 (Ural) , TG #8, TPS #8 "Mosenergo" ( Moscow)
• T-250 (Ural) , TG #10, TPS #22 "Mosenergo" ( Moscow)

The last generation systems are working at:

• K-210 (LMZ), TG #2, Shatura TPS #5 (Moscow region)
• K-300 (LMZ), TG #1, TPS #24 (Moscow region)

At present time the BAPAS is being installed on :

• K-215 (LMZ), TG #1, Pskov TPS (Pskov region)
• K-500 (Charkov), TG #1, Smolensk NPS (Smolensk region)
• K-1000 (LMZ), TG #3, South-Ukrainian NPS (Ukraine)

8. Proof of effectiveness

The damages registered by the BAPAS were confirmed by visual examination of the blading after stopping of the turbine.
E.g. TPS #8 "Mosenergo" (Moscow), 1997, breaking of damping wire.

9. Installation works period

The system may be assembled within 10-15 days and commissioned within a month after first starting of the turbine.

10. Scope of delivering

• BAPAS hardware ( assembled, adjusted and tested)
• BAPAS software installed and tested
• system description and manuals
• user's instruction course
• consulting and serving

In addition, supplier delivers free of charge the new versions of software during first year after commissioning.

11. Guarantees

The guarantees of the supplier of the BAPAS cover the period of two years.
The guarantee for the sensors installed inside the LP cases covers the period of 5 years.