How do you carryout performance Guarantee (PG) test of power plant equipments??


What do you mean by performance Guarantee (PG) test?

 It is a test carried out to measure the performance of an equipment as guaranteed by the manufacturer.

What are the equipments on which PG test is carried out in power plants?

Generally all the equipments should met manufacturer guarantee performance value, but in Power plant, Boiler, Turbine & Generators are the major & critical equipments where PG tests are carried out.

When & who do carryout PG test?

PG test is carried out after erection & commissioning of the equipments and before hand over of the equipments PG test is carriedout.PG test is carried out. It is carried out by Original Equipment Manufacturer (OEM).

How do you carryout PG test?

For conducting the PG test, some parameters are measured & compared with standard design & operating values. Before conducting PG test, it is mutually agreed between OEM & Owner what parameters to be measured & means of measurement. And also it is mutually agreed that, how much time this test will be conducted. In some cases PG test is conducted for 8 hours, in some cases 24 hours.

And also the frequency of parameters measurement is decided before commence of PG test.

Procedure for PG test.

Testing Methodology: Standard testing methodology is decided

Testing equipment: Type of equipment, its measuring accuracy & calibration reports

Tolerance: The margin of error.

Ambient temperature: It is most important for conducting PG test since all the equipments & systems are designed on the basis of atmospheric temperature.

Parameters Log sheet & List of Operation team to be involved in PG tests are decided before the test.

Once the PG test completes, log sheets are collected & should be signed by owner & OEM for future reference.

What is the significance of carrying out PG test in Boilers?

PG test is carried out to ensure following key performance Indicators (KPIs) of Boiler

  • Specific fuel consumption of the Boiler or steam to fuel ratio (SFR)
  • Steam Purity
  • Steam pressure & temperature at various operating condition
  • Boiler efficiency
  • Load stability during various load demand
  • Stack gas quality
  • Minimum & maximum rating
What parameters are measured during Boiler PG test?
  • Steam pressure & temperature
  • Steam flow & feed water flow
  • Fuel consumption
  • Attemperator/Desuper heater water flow
  • Feed water parameters like pH, conductivity, silica, Hydrazine
  • Boiler Water parameters like pH, conductivity, silica, Phosphate
  • Steam parameters like pH, conductivity, silica etc
  • Feed water temperature at Deaerator outlet
  • Feed water temperature at Economiser inlet
  • Exhaust flue gas temperature
  • Excess air & O2% in flue gas
  • Flue gas parameters like SPM, SOx, NOx etc
  • ESP & APH inlet & outlet flue gas temperature for air leakage test
  • Combustion air temperature after APH
  • Unburnt level in ash
  • CBD water flow
  • Drum level
  • Boiler auxiliary power consumption
  • Operating % of load Fans& fuel feeding system at various Boiler load.

In this test, a boiler is allowed to generate steam at various load conditions. Its capability to generate steam at required parameters and required efficiency is checked.

Note: While conducting Boiler PG test, input parameters like fuel moisture, GCV etc kept as per design values

What is the significance of carrying out PG test in Turbines?

PG test is carried out to ensure following key performance Indicators (KPIs) of Boiler

  • Specific steam consumption (SSC)
  • Exhaust steam temperature
  • Condenser vacuum
  • Heat rate & efficiency
  • Turbine bearing vibrations & temperature
  • HP valve demand during various load demand
  • Turbine Noise level
  • Stability during sudden load cut off
  • Steam pressure & temperature of extraction & bleed steam
  • Turbine auxiliary power consumption

What parameters are measured to conduct PG test of steam Turbine?

  • Turbine inlet steam pressure & temperature
  • Turbine inlet steam flow
  • Auxiliary steam flow
  • Condenser inlet & outlet cooling water temperature
  • Turbine & Gear box all bearings & vibrations
  • Noise level around turbine
  • Load on Generator
  • Oil cooler inlet & outlet water & oil temperature
  • HP & LP valve lift & demand
  • Turbine casing thermal expansion
  • Wheel chamber pressure
  • Pressure, temperature & steam flow of extraction & bleed steam
  • Exhaust steam pressure, temperature and flow

What parameters are checked for PG test of Generators?

  • Generator output power
  • Terminal voltage
  • Frequency
  • Current
  • Power factor
  • Winding & air temperature
  • Air cooler inlet & outlet water temperature



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