PLANT OVERVIEW

NTPC Talcher-Kaniha (TSTPS) plant is located in Kaniha block under Talcher sub-division of Angul

district in the state of Orissa.

Nearest Town : Talcher 26 KMs

Nearest Railway Station : Talcher 29 KMs

Nearest Airport : Bhubaneswar 180 KMs

INSTALLED CAPACITY

STAGE - I - 2 Units each 500 MW - Total 1000 MW

STAGE- II - 4 Units each 500 MW - Total 2000 MW

EQUIPMENTS INVOLVED

Stage-II Boiler:- 4 X 500 MW, Circulation type two pass boiler with Drum.

Maximum Height of Boiler:- 85 Mtr. Make:- BHEL,

Three banks of Economiser, Two banks of LTSH are arranged Horizontally and Divisional Panel,

Platen Super Heater, Reheater are arranged vertically.

In addition to main Boiler following equipments are included per unit:-

88 Nos of Wall Blower and 34 Nos of LRSB per boiler. Boiler is equipped with 16 nos Spring Loaded safety valves, 8 Electromatic Relief valves .All Boiler valves except the control valves/Block valves are of BHEL make and mostly are under size 150 Nb. Boiler Burner is having 40 coal nozzles & 20 Oil guns. Piping hangers are of constant load, variable load and rigid strut type hangers total approximately 300 nos at different location and elevations.

BRIEF DESCRIPTION OF WORKS:

For Improvement of Boiler Performance, NTPC Ltd. has decided to incorporate some Boiler Modifications as mentioned below at NTPC, Talcher-Kaniha in its Stage-II Units. It is intended to carry out modification work in Unit-III in the FY 2015-16.

a. Installation of additional bank of LTSH (Low Temperature Superheater):

Presently, there are two banks of LTSH Coils above the Economiser located in the 2^nd pass. There is sufficient space above the existing upper bank of the LTSH and it has been planned to add another LTSH bank in this available space. This new LTSH Bank shall be of 130 coils (65 pairs) loaded on four rows of hanger tubes, similar to existing LTSH Upper bank. Each coil shall be having 12 tubes of size: 47.63 mm OD x 6.6 mm thickness and material SA 213 T11grade.

b. Replacement of 23 panels in Final Reheater:

There are 78 Panels of Reheater. The Reheater is in two stages. One set of panels are Reheater Inlet panels and the other set of Panels is final reheater panels. In Unit-III, there are 10 circuits in each panel. The panels are numbered from 1 to 78 from Boiler left to boiler right. The right 23 panels are intended for replacement completely. Presently, it comprises of T91 and T22 tubes of size: 54 mm OD x 4.5 mm. Now, it has been planned to replace the same with Stainless steel material of type SA213 TP 347 grade of tube size: 54 mm OD x 4.5 mm.

c. Replacement of first four circuits of Final Reheater Panel Nos.1 to 55:

As mentioned above, there are 78 panels of reheater. The reheater is in two stages. The panels are numbered from 1 to 78 from Boiler left side to Boiler right side. In Unit-III, the first four loops of the Final reheater panels numbered from 1 to 55 shall be replaced with Stainless steel as per SA 213 TP 347 loops. Presently, it comprises of T91 and T22 tubes of size: 54 mm OD x 4.5 mm. Now, it has been planned to replace the same with Stainless steel material of type SA213 TP 347 grade of tube size: 54 mm OD x 4.5 mm.

d. Replacement of Single Reheater Outlet Header with Siamese Headers:

Presently, the final reheater loops are all connected to a single reheater header. This header is the outlet header and it discharges hot steam at desired steam parameters to IPT. In Unit-III, it is intended to replace this single header with two different Siamese headers. Half of the final reheater tubes shall be connected to one Header and the other half shall be connected to the other header.

e. Modification of Crisscross connection in the Superheater Circuit Headers:

The steam from the Boiler drum goes to Low Temp. Super Heater (LTSH), first stage of superheating process. After heating in LTSH coils, it goes to the LTSH Outlet Header. From the LTSH Outlet Header, steam goes to Divisional Superheater Inlet header. The Steam after getting superheated in the Divisional Superheater goes to the outlet header. The Steam from the Divisional panel outlet header goes to the Inlet header of the Platen Superheater, where it gets further superheated and finally goes to the Platen super heater outlet header and moves to HPT as Main steam.

Presently, the LTSH Outlet header and the Divisional panel inlet header are connected criss-cross by means of connecting pipes whereas the Divisional Panel Outlet header to the Platen Superheater Inlet header is connected straight through by means of connecting pipes. Now, in Unit-III, it is intended that the criss-cross connection between the LTSH Outlet header and the Divisional panel inlet header shall be connected straight through whereas the Divisional Panel Outlet header to the Platen Superheater Inlet header shall be connected as criss-cross.