Boiler Feed Pumps

 

Applications:

  • Utility thermal power station
  • Combined cycle power plant

Design features:

  • Barrel / ring section construction
  • Full cartridge design
  • No warm-up required for standby pumps
  • Stiff shaft design
  • 40,000 hours and erosion free life of first stage impeller
  • Balancing drum
  • Tilting pad type thrust bearing
  • Cartridge type mechanical seals

Design Options:

  • Direct driven pumps at constant speed operation for captive power plants and the smaller utility sets of 60 MW and 110 MW.
  • Constant speed pumps driven through a set-up gearbox for higher rating captive plant and combined cycle plants.
  • Variable speed operation of pumps using
    1. Hydraulic coupling
    2. Drive turbine
    3. Variable frequency drive


 

Frame Size

Application

FRH-27

Combined Cycle plants

150 KHI

60 MW Thermal Plants

200 KHI

110 MW Thermal Plants

FK6D30

210/250 MW Thermal Plants

FK4E36

500 MW Thermal Plants


200 KHI-S Boiler Feed pump

 

Salient features:

 

1. Cartridge Design for easy maintainability

 

The existing design of inside stator assemble comprises of the rotor and stator parts. To complete the pump assembly using this inside stator, it involves extensive work of assembling the balance components like HP cover, LP cover, Mechanical seals, Bearing housings, Journal and thrust bearings and accurate centering of the Rotor which is a skilled and time consuming job, taking about 6 to 8 shifts for the re-assemble at site.

 

The upgraded design cartridge assembly comprises of almost all the parts of the pump, except for the outer barrel. This is offered in a fully centered and balanced condition ready for insertion into the existing pump barrel at site. This job can be easily carried out at site even by semi skilled work force within a short period of maximum two shifts, thereby increasing the availability of the pumps.

 

 

2. Higher efficiency for lower energy consumption costs

 

Upgraded design cartridge assembly fitted with high-efficiency hydraulic components result in lower power consumption by the pump, thereby saving valuable energy resource and cutting down operational costs.

 

3. Balance Drum design for increased reliability of operation

 

The present design pump internals are with balance disc arrangement, which works with an axial gap for hydraulic balance of axial thrust, which has an inherent risk of seizure during initial start and transient operating conditions. The upgraded design cartridge is provided with balance drum design arrangement, which works on a radial gap between rotating and stationary components, elimination the risk of seizure, thereby increasing the reliability of operation for all operating conditions.

 

4. Hydraulic stud tensioning for lower assembly time

 

The present design for tightening of discharge cover bolts is through expansion using electrical bolt heating elements and manual tightening, which is a time consuming and ineffective practice. The upgraded design cartridge is provided with a hydraulic stud tensioner for more accurate control of the tightening torque values and reduction in assemble time.

Benefits of the upgraded cartridge design vis-a-vis existing inside stator design

Feature

Upgraded design (New)

Existing design (Old)

 

EFEICIENCY

Fitted with improved and new hydraulics (Impeller and Diffuser) which gives efficiency of 80%.

Efficiency 72% only.

 

REPLACING PERIOD

Can be replaced in two shifts.

Takes around six shifts.

 

RELIABILITY

Fitted with Balance drum, which works with a radial gap for hydraulic balance of axial thrust. This is more reliable than Balance disc.

Fitted with Balance disc which works with an axial gap for hydraulic balance of axial thrust.

 

TIGHTENING OF DISCHARGE COVER BOLTS

Provided with hydraulic stud tensioning unit for loosening and tightening of Discharge cover nuts, thus simple and fast.

Electrical heating elements are used for loosening and tightening of the nuts, which consumes lot of time.

 


In view of this manifold advantages using upgraded design, it is recommended to all the customers of 110 MW & 210 MW Power Stations operating with Czech Design 200 KHI Boiler Feed Pumps, to opt for their replacement with cartridges of upgraded design, for increase of pump availability and reliability and considerable reduction in operational costs.