Sootblower Manual

AC 22.10.
2014 Denis See compliance sheet Busekrus

AB 04.08.2014 Denis See compliance sheet Busekrus
AA 22.05.2014 Denis See compliance sheet Busekrus
REV. DATE NAME REVISION DESCRIPTION APPD.
OWNER
MEJA URJA NIGAM PVT. LTD.
(A JOINT VENTURE COMPANY OF NTPC & UPRVUNL)
CONSULTANT
NTPC Limited
(A Government of India Enterprise)
PROJECT
MEJA THERMAL POWER PROJECT (2x660 MW)
STEAM GENERATOR (SG) PACKAGE
PACKAGE
SG CONTRACTOR
BGR ENERGY SYSTEMS LIMITED
CHENNAI – HYDERABAD – MUMBAI - NOIDA

VENDOR DOC.
NO.
JV COMPANY
BGR BOILERS PRIVATE LIMITED
CHENNAI – INDIA
VENDOR DOC.
NO.
QSGM SUB CONTRACTOR
HITACHI POWER EUROPE (IF APPLICABLE)
GMBH
Duisburg - Germany
VENDOR DOC. SUB CONTRACTOR DOC.
NO.
N-100141-S-H__-IB07-00011 NO.
TITLE: Digitally signed
Signature Not Verified
by Mohit Jain
Design Report Steam Soot Blowers
Date: 2014.11.20
16:54:18 IST
Reason: CAT I
NTPC DOCUMENT NO. 0306-102-PVM-U-0951 REV. 03Location: SCALE SIZE
NTPCEOC
NAME SIGN DATE
PREPARED BY Denis Signed by Denis 22.11.2013
CHECKED BY Busekrus Signed by Busekrus 22.11.2013
REVIEWED BY Busekrus Signed by Busekrus 22.11.2013
APPROVED BY
REVIEWED BY (QSGM) Busekrus Signed by Busekrus 22.11.2013
APPROVED BY (QSGM) Busekrus Signed by Busekrus 22.11.2013 SHT. NO. 1 OF 54
THIS DOCUMENT SHALL NEITHER BE DUPLICATED; TRANSFERRED NOR REVISED OTHER THAN STIPULATED WITH THE GCC
Kennwort / Code Word
Design Report Steam
Soot blowers NTPC Meja
VENDOR DRG NO. Proj-Nr.:/ Job No.:
N-100141-S-H__-IB07-00011
NTPC DRG NO.
N-100141
0306-102-PVM-U-0951
Design Report Steam Soot Blowers
Ersteller / Prepared by Geprüft / Checked by: Datum /Date: Rev.:

Denis Busekrus 22-10-2014 AC
Page: 2 / 54
Design Report Steam
N-100141-S-H__-IB07-00011
NTPC DRG NO.
N-100141
0306-102-PVM-U-0951
Table of Contents
1 Introduction ................................................................................. 6
2 Boiler Soot Blower ...................................................................... 9
2.1 Demands.................................................................................................................. 9
2.2 Design Criteria ........................................................................................................ 9
3 Soot Blower Valves Boiler ........................................................ 11

3.1 Pressure Reducing Station .................................................................................. 11
3.1.1 Demands ................................................................................................................................ 11
3.1.2 Design Criteria Pressure Reducing Station ....................................................................... 11
3.2 Soot blower Safety Valve ..................................................................................... 13
3.2.1 Demands ................................................................................................................................ 13
3.2.2 Design Criteria Safety Valve ................................................................................................ 13
3.2.3 Design .................................................................................................................................... 13
3.2.4 Sample calculation of the Kv-Value .................................................................................... 15
3.2.1 Pressure losses Design Conditions.................................................................................... 16
3.2.1 Pressure losses Working Conditions ................................................................................. 17
3.3 Throttle Valves ...................................................................................................... 18
3.3.1 Design Criteria ....................................................................................................................... 18
3.4 Warm-up Control Valve for Bundle Soot Blower System ................................... 19
3.4.1 Demands ................................................................................................................................ 19
3.4.2 Design Criteria Warm-up Control Valve .............................................................................. 19
3.5 Orifice Bundle Sootblower System (Hot Standby).............................................. 21
3.5.1 Design Criteria ....................................................................................................................... 21
3.5.2 Design Orifice Bundle Soot Blower .................................................................................... 22
3.1 Pressure Drop ....................................................................................................... 25
3.2 Warm-up Control Valve for Furnace Wall Blower System.................................. 27
3.3 Orifice Furnace Wall Blower System (Hot standby) ........................................... 28
3.4 Pressure Drop ....................................................................................................... 29
3.5 Diagram for pressure downstream Pressure Reducing Station ........................ 36
3.6 Velocity in soot blower pipes ............................................................................... 37
4 Soot Blower Valves Air Pre-Heater .......................................... 38

4.1 Pressure Reducing Station RAPH ....................................................................... 38
4.1.1 Demands ................................................................................................................................ 38
Page: 3 / 54
Design Report Steam
N-100141-S-H__-IB07-00011
NTPC DRG NO.
N-100141
0306-102-PVM-U-0951
4.1.2 Design Criteria ....................................................................................................................... 38

4.2 Soot blower Safety Valve RAPH........................................................................... 39
4.2.1 Demands ................................................................................................................................ 39
4.2.2 Design Criteria ....................................................................................................................... 40
4.2.3 Design .................................................................................................................................... 40
4.3 Throttle Valves RAPH ........................................................................................... 41
4.3.1 Design Criteria ....................................................................................................................... 41
4.4 Warm up Control Valve RAPH .............................................................................. 42
4.4.1 Demands ................................................................................................................................ 42
4.4.2 Design Criteria ....................................................................................................................... 42
4.5 Orifice RAPH Sootblower System (Hot Standby) ............................................... 44
4.5.1 Design Criteria ....................................................................................................................... 44
4.5.2 Design Orifice RAPH Soot Blower ...................................................................................... 44
4.1 Diagram for pressure downstream Pressure Reducing Station ........................ 50
4.1 Velocity in soot blower pipes ............................................................................... 50
5 Compliance sheet ..................................................................... 51

Page: 4 / 54
Design Report Steam
N-100141-S-H__-IB07-00011
NTPC DRG NO.
N-100141
0306-102-PVM-U-0951
Table of Figures
Figure 1: Basic overview of Boiler & Air Heater Soot Blowers................................................... 8

Figure 2: Overview of Kv - value of the pressure reducing station .......................................... 14
Figure 3: Calculation of mass flow for bundle Soot blower Safety Valves ............................... 14
Figure 4: Pressure loss table as reference for the Kv-Value calculation and CV design (used
for Kv-Value calculation and CV design) ......................................................................... 16
Figure 5: Pressure loss table as reference for the Kv-Value calculation and CV design (used
for Kv-Value calculation and CV design) ......................................................................... 17
Figure 6: Overview of Warm-up design mass flow for Bundle Soot Blowers ........................... 20
Figure 7: Design Criteria Orifice (Hot Stand By) for Heating Surface Soot Blowers ................ 23
Figure 8: Overview of warm-up design mass flow for Furnace Wall Blowers .......................... 27
Figure 9: Design Criteria of Orifice (Hot stand by) for Furnace Wall Blowers .......................... 28
Figure 8: Overview of Kv - value of the pressure reducing station .......................................... 40
Figure 9: Calculation of mass flow for RAPH soot blower safety valves .................................. 41
Figure 10: Overview of warm-up design mass flow for Air Heater Soot Blowers ..................... 43
Figure11: Design Criteria of Orifice (Hot stand by) for Air Heater Soot Blower ....................... 45

Page: 5 / 54
Design Report Steam
N-100141-S-H__-IB07-00011
NTPC DRG NO.
N-100141
0306-102-PVM-U-0951
1 Introduction
The steam soot blower system is used to maintain cleanliness in the convective heating
surfaces, the furnace walls and the air preheater. By periodic removal of ash and slag from the
heating surfaces the efficiency and capacity of the heat-transfer surfaces is obtained.
In Figure 1 a basic overview of boiler & air heater soot blowers is given.
The steam tapping point for the tube banks and furnace walls soot blower is the RH1 inlet
header. By passing the pressure reducing station, tapped superheated steam will be reduced
to a constant pressure set value. Downstream the pressure reducing station, the line is divided
to supply the steam soot blowers of the furnace walls and the tube banks.
The steam tapping point for the air heater soot blowers is the RH2 inlet header. Similar to the
boiler soot blowers, superheated steam will be reduced to a constant pressure set value by the
pressure reducing station. Each air heater is equipped with one soot blower on the cold side.
Spring loaded safety valves on air preheater and also on the boiler soot blower line protects
the systems against excess pressure.
Following documents should be taken as design criteria reference:
Unheated pressure parts: Doc. No.: 9571-102-PVM-Y-0028

0360-102-PVM-Y-0028
Predicted performance data: Doc. No.: 9571-102-PVM-Y-0012

0360-102-PVM-Y-0012
Boiler upper part longitudinal section: 9571-102-PVM-B-0149

0360-102-PVM-B-0149
Boiler lower part longitudinal section: 9571-102-PVM-B-0151

0360-102-PVM-B-0151

Page: 6 / 54
Design Report Steam
N-100141-S-H__-IB07-00011
NTPC DRG NO.
N-100141
0306-102-PVM-U-0951
P&I-Diagram Steam Soot Blower Tube Banks: 9571-102-PVM-F-0088

0360-102-PVM-F-0088
P&I-Diagram Steam Soot Blowers Furnace: 9571-102-PVM-F-0089

0360-102-PVM-F-0089
Process Description Soot Blowers: 9571-102-PVM-X-0192

0360-102-PVM-X-0192
Design Data Soot Blower System: 9571-102-PVM-Y-0016

0360-102-PVM-Y-0016
Design Data Sheet of Steam Sootblower Control Valves: 9571-102-PVI-Y-0688

0360-102-PVI-Y-0688
Design Data Sootblower Safety Valves: 9571-102-PVM-Y-0048

0360-102-PVM-Y-0048
Design Data Sheet of Steam Sootblower Throttle Valve: 9571-102-PVM-Y-0184

0360-102-PVM-Y-0184

Page: 7 / 54
Design Report Steam
N-100141-S-H__-IB07-00011
NTPC DRG NO.
N-100141
0306-102-PVM-U-0951
RH1 Inlet
LEGEND
RH2 inlet
Stop Valve / Throttle Valve
M Motorized Stop Valve
M Pressure Reducing Station
Pneumatic Control Valve
Safety Valve
Flow Measurement
Orifice
M
Soot Blower
Eco Tube Banks
Superheater and Reheater Tube Banks
Furnace Walls To Flash Tank

Wall Blowers (Steam)
To Flash Tank
4 Regenerative Airheaters (RAH)

(Sootblowers supplied by supplier of RAH)
To Flash Tank
Figure 1: Basic overview of Boiler & Air Heater Soot Blowers.

Page: 8 / 54
Design Report Steam
N-100141-S-H__-IB07-00011
NTPC DRG NO.
N-100141
0306-102-PVM-U-0951
2 Boiler Soot Blower
2.1 Demands
As per tender following requirements are considered as design criteria for boiler and air heater
soot blowers: technical specification section-VI sub section 2 M1 part B 17.08.00 b) the drive
way of the long retractable soot blowers is the half of the Steam generator width on each side.
Additional amount of 20 retrofit wall blowers and are considered as per specification in sub
section II M1 part B 05.14.00 a). Following document should be considered in regard to this
chapter: Design Data Soot Blower System (9571-102-PVM-Y-0016/0360-102-PVM-Y-0016).
2.2 Design Criteria
Design Criteria for boiler and air heater soot blowers are given in the document “Design Data
Soot Blower System”. The operating blowing medium temperatures and pressures upstream
the reducing station are taken at RH1 and RH2 inlet header as per predicted performance
data. An additional allowance of 5°C is considered regarding the design temperatures of the
soot blower pipes. Actually the temperature allowance is higher than 5°C in reference to the
soot blower pipes upstream the pressure reducing station. This is a result of modified cold
reheat temperature by turbine supplier. The design pressure of the soot blower pipes
upstream the pressure reducing station is same as the Reheater system design.
According to the increasing fouling tendency at end of travel time of the boiler, the Flue gas
temperature is given for both, the furnace and the convective part, which should be used by
the soot blower supplier. The flue gas temperature at 100% reference coal (Design Coal)
represents the average temperature in the soot blower gap and is as per predicted
performance data.
To assure the cleaning of the furnace walls, the quantity of wall blowers is chosen to 70 units
and the long retractable soot blowers to 60 units, as per TCM from 29th of July to 3rd of August
in Duisburg. Additional 20 retrofit wall and 20 retrofit long retractable soot blowers are
considered.

Page: 9 / 54
Design Report Steam
N-100141-S-H__-IB07-00011
NTPC DRG NO.
N-100141
0306-102-PVM-U-0951
Downstream the pressure reducing station the operating pressure will be reduced to 22,4
kg/cm² (a). The design pressure downstream pressure reducing station is 30,6 kg/cm² (a).
The given alpha values for design soot blowers are calculated in accordance of the FDBR
7.1.3.-21+22 and represents the radiant and convective heat transfer from flue gas to the soot
blower material.

Page: 10 / 54
Design Report Steam
N-100141-S-H__-IB07-00011
NTPC DRG NO.
N-100141
0306-102-PVM-U-0951
3 Soot Blower Valves Boiler

Following chapters represent the design of boiler soot blower valves, the pressure reducing
stations and the safety valves. Valves should be able to realize high capacities at low pressure
drop and low capacities at high pressure drop. Therefore additional load cases in the
corresponding documents, if necessary, are given for supplier.
3.1 Pressure Reducing Station
3.1.1 Demands
Three Pressure Reducing Stations in total are considered in the boiler soot blowers system.
Two stations are 100% redundant and one is designed for 40% capacity, as per technical
specification section VI; Part A; sub section III A1; clause no. 1.09.03.
As per specification the leakage class of the station is “IV” and the maximum noise with sound
isolation in 1 meter distance is 85 dB(A). Following document should be considered in regard
to this chapter: Design Data Sheet of Steam Sootblower Control Valves (9571-102-PVI-Y-
0688/0360-102-PVI-Y-0688).
3.1.2 Design Criteria Pressure Reducing Station

Extracted steam of the RH 1 inlet headers will be reduced to required soot blower pressure
values by the Pressure Reducing Station.
The soot blower mass flow is considered as per soot blower supplier, which is illustrated in the
following.
Following mass flows is taking place for the long retractable soot blowers:
• Steam mass flow required for SH Soot blower: 2,43 kg/sec
• Steam mass flow required for RH Soot blower: 1,59 kg/sec
• Steam mass flow required for Economizer Soot blower: 1,1 kg/sec
• Steam mass flow required for hot-standby of the system: 1,2 kg/sec
• Steam mass flow required for warm up the Soot blower System: 3,2 kg/sec

Page: 11 / 54
Design Report Steam
N-100141-S-H__-IB07-00011
NTPC DRG NO.
N-100141
0306-102-PVM-U-0951
Following mass flows is taking place for the wall blowers:
• Steam mass flow required for each Wall Blower: 0,55 kg/sec
• Steam mass flow required for warm up the Soot Blower System: 0,8 kg/sec
Maximum 2 bundle and 2 wall blowers in operation simultaneously
Total mass flow of the pressure reducing station (including hot standby):
2 * 2,43 + 1,2 + 2 * 0,55 + 0,4 = 7,56 kg/sec
Total mass flow for warm up: 3,2 + 0,8 = 4 kg/sec
The operating temperatures and pressures upstream and downstream the pressure reducing
stations are given in the design data sheet steam soot blower control valves. The total soot
blower mass flow, including the hot stand by, is considered from 100%BMCR up to Benson
minimum load 35%BMCR. The total warm up mass flow is considered for 25%BMCR, as the
initiation of warm up will start at this load case.

Page: 12 / 54
Design Report Steam
N-100141-S-H__-IB07-00011
NTPC DRG NO.
N-100141
0306-102-PVM-U-0951
3.2 Soot blower Safety Valve
3.2.1 Demands
As per technical specification section-VI part-A sub-section-III:A1 clause No. 1.10.04 the
safety valve downstream of the steam pressure reducing valve shall be designed for a flow
corresponding to the pressure control valve fully open condition and the upstream main
steam/cold reheat pressure being maximum expected. Following document should be
considered in regard to this chapter: Design Data Soot Blower Safety Valves (9571-102-
PVM-Y-0048/0360-102-PVM-Y-0048).
3.2.2 Design Criteria Safety Valve

Spring loaded safety valve on the boiler soot blower line protects the system against excess
pressure. One safety valve for the soot blower boiler line will be provided. Same mass flow
assumptions as for pressure reducing station were done for the safety valve. The set pressure
of the safety valve is same as the design pressure of the pipe.
3.2.3 Design
The Design criteria for the soot blower safety valves are given in a separate document
“Design Data Soot Blower Safety Valves”. This document should be taken in consideration
in regard to this chapter.
By using the mass flow of chapter 3.1.2 plus additional margin, the Kv-Value is calculated for
the pressure reducing station as shown in following Figure 2. The input values are taken from
the 35% BMCR load case. An example calculation of the Kv-Value is shown in chapter 3.2.4.

Page: 13 / 54
Design Report Steam
N-100141-S-H__-IB07-00011
NTPC DRG NO.
N-100141
0306-102-PVM-U-0951
Maximum Flow rate kg/s

10,1
Pressure Reducing Station inlet maximum Flow rate at 35% BMCR load kg/h 36360,0
Pressure Reducing Station inlet temperature at 35% BMCR load °C 337,5
bar(a) 20,0
Pressure Reducing Station inlet pressure
kg/cm²(a) 20,4
Pressure Reducing Station inlet enthalpy kJkg 3109,7
bar 4,0
Pressure Reducing Station outlet differential pressure
kg/cm² 4,1
bar(a) 16,0
Pressure Reducing Station outlet pressure
kg/cm²(a) 16,3
Pressure Reducing Station specific volume outlet m³/kg 0,1707
=> Kv-value m³/h 237,5
Kvs chosen m³/h 245,0
Figure 2: Overview of Kv - value of the pressure reducing station
Due to valve specification requirements for the valve supplier, additional margin is chosen for
design of the soot blower safety valves. The total mass flow of the Safety Valve is calculated
by using the Kv-Value and the isenthalpic relaxation of the highest operation pressure and
temperature upstream the pressure reducing station.
bar(a) 69,7
kg/cm²(a) 71,1
bar(a) 30,0
Set pressure SV
kg/cm²(a) 30,6
bar(a) 30,0
=> Pressure Reducing Station outlet pressure
kg/cm²(a) 30,6
Pressure Reducing Station inlet temperature °C 350,0
Pressure Reducing Station inlet enthalpy kJ/kg 3017,7
Pressure Reducing Station outlet specific volume m³/kg 0,0830
=> Pressure Reducing Station outlet flow m³/s 3,9
Mass Flow kg/s 47,1
Mass Flow chosen kg/s 47,10
Mass Flow chosen t/h 170
Figure 3: Calculation of mass flow for bundle Soot blower Safety Valves

Page: 14 / 54
Design Report Steam
N-100141-S-H__-IB07-00011
NTPC DRG NO.
N-100141
0306-102-PVM-U-0951
3.2.4 Sample calculation of the Kv-Value

Page: 15 / 54
Design Report Steam
N-100141-S-H__-IB07-00011
NTPC DRG NO.
N-100141
0306-102-PVM-U-0951
3.2.1 Pressure losses Design Conditions

100% BMCR 35% BMCR
Pressures Pressures
S. Inlet Outlet ∆p Inlet Outlet ∆p
Description
No. kg/cm² kg/cm² kg/cm² kg/cm² kg/cm² kg/cm²
1 Reheater I/L Header
54.50 54.42 0.08 21.70 21.67 0.03
2 Nipples
54.42 54.41 0.02 21.67 21.63 0.04
3 From RH tapping point

54.41 54.36 0.04 21.63 21.53 0.09
4 Isolation valve (manual)

54.36 54.21 0.16 21.53 21.17 0.36
5 Isolation valve (motorised)

54.21 54.05 0.16 21.17 20.81 0.37
6 Connecting pipe upto PRS

54.05 53.88 0.18 20.81 20.40 0.41
Pressure Drop PRS

29.61 29.61 4.08 4.08
1 PRS to isolation valve

24.27 24.27 0.00 16.32 16.32 0.00

24.27 24.13 0.14 16.32 16.12 0.19
3 Isolation valve to flow meter

24.13 24.06 0.07 16.12 16.03 0.10
4 Flow meter
24.06 23.57 0.49 16.03 15.36 0.67
5 Connecting pipe to T-Piece

23.57 23.54 0.04 15.36 15.31 0.05
6 T-Piece
23.54 23.49 0.05 15.31 15.24 0.07
7 T-Piece to isolation valve

23.49 23.35 0.14 15.24 15.04 0.20

23.35 22.93 0.41 15.04 14.45 0.59
9 Isolation valve to SB drain line

22.93 18.68 4.26 14.45 6.44 8.01
10 SB drain line to throttle valve

18.68 18.64 0.03 6.44 6.31 0.13
11 Throttle valve (Temperature measurement)

18.64 18.49 0.15 6.31 5.81 0.50
12 SB drain line TV to T-Piece

18.49 18.49 0.00 5.81 5.80 0.01
13 T-Piece
18.49 18.45 0.04 5.80 5.67 0.13
14 T-Piece to Control Valve

18.45 18.44 0.01 5.67 5.63 0.04
Total Pressure Drop downstream
PRS/Total Pressure drop sootblower 5.83 36.06 10.69 16.07
system
Figure 4: Pressure loss table as reference for the Kv-Value calculation and CV design (used for
Kv-Value calculation and CV design)

Page: 16 / 54
Design Report Steam
N-100141-S-H__-IB07-00011
NTPC DRG NO.
N-100141
0306-102-PVM-U-0951
3.2.1 Pressure losses Working Conditions

100% BMCR 35% BMCR
Pressures Pressures
Description
54.50 54.42 0.08 21.70 21.67 0.03
2 Nipples
54.42 54.41 0.01 21.67 21.64 0.03

54.41 54.39 0.03 21.64 21.58 0.06

54.39 54.30 0.09 21.58 21.34 0.24

54.30 54.21 0.09 21.34 21.09 0.24

54.21 54.11 0.10 21.09 20.82 0.27
Pressure Drop PRS

31.68 31.68 4.08 4.08

22.43 22.43 0.00 16.74 16.74 0.00

22.43 22.35 0.09 16.74 16.61 0.13

22.35 22.31 0.04 16.61 16.55 0.06
4 Flow meter
22.31 22.01 0.29 16.55 16.12 0.43

22.01 21.99 0.02 16.12 16.08 0.03
6 T-Piece
21.99 21.96 0.03 16.08 16.04 0.04

21.96 21.87 0.09 16.04 15.91 0.13

21.87 21.62 0.25 15.91 15.53 0.38

21.62 19.14 2.48 15.53 11.35 4.18

19.14 19.11 0.03 11.35 11.28 0.07

19.11 18.96 0.15 11.28 11.00 0.28

18.96 18.96 0.00 11.00 11.00 0.00
13 T-Piece
18.96 18.92 0.04 11.00 10.93 0.07

18.92 18.91 0.01 10.93 10.91 0.02

system
Figure 5: Pressure loss table as reference for the Kv-Value calculation and CV design (used for
Kv-Value calculation and CV design)

Page: 17 / 54
Design Report Steam
N-100141-S-H__-IB07-00011
NTPC DRG NO.
N-100141
0306-102-PVM-U-0951
3.3 Throttle Valves
3.3.1 Design Criteria
One throttle valve in each line will be provided. During commissioning the warm keeping mass
flow to both soot blowing lines will be adjusted manually, in order to equalize the temperatures
downstream the soot blowers. As written in chapter 3.1.2 the total steam mass flow required
for hot-stand by is 1.2 kg/sec. for the long retractable soot blower and 0.4 kg/sec. for the wall
blowers. Each line will be charged with half of the hot stand by flow. The described procedure
can be found in the “Design Data Sheet of Steam Soot blower Throttle Valves”
.
During startup of the boiler, the soot blower system will be pre warmed. The pre warming
process will start at 25%BMCR load as described in the “Process Description Steam Soot
blower” in the chapter 2.1.6. Thus the system will be charged with warm up mass flow as given
in chapter 3.1.2. The maximum throttle valve mass flow is achieved during warm up of the
boiler as can be seen in the “Design Data Sheet of Steam Soot blower Throttle Valves”. Both
the minimum and the maximum conditions are sufficient to design the throttle valves. No
additional conditions will be incorporated, in respect of no further use for the supplier.
Following document should be considered in regard to this chapter: Design Data Sheet of
Steam Sootblower Throttle Valves (9571-102-PVM-Y-0184/0360-102-PVM-Y-0184).

Page: 18 / 54
Design Report Steam
N-100141-S-H__-IB07-00011
NTPC DRG NO.
N-100141
0306-102-PVM-U-0951
3.4 Warm-up Control Valve for Bundle Soot Blower System
3.4.1 Demands
The complete soot blower piping shall be warmed up as per technical specification section-VI
part-A sub section III A1 clause No. 1.09.02. Relevant information related to the warm up
process of the boiler is given in the “Process Description Steam Soot blower”. Following
document should be considered in regard to this chapter: Design Data Sheet of Steam
Sootblower Control Valves (9571-102-PVI-Y-0688/0360-102-PVI-Y-0688).
3.4.2 Design Criteria Warm-up Control Valve
During start up, the warm-up control valve is fully opened and steam is led to the start-up flash
tank. By reaching a defined pressure downstream of the pressure reducing station and a
defined temperature downstream of the last steam blowers, the warm-up CV is closed and the
hot standby is maintained via the orifice in the bypass.
The warm-up control valve will be charged by the maximum mass flow during the warm up
procedure of the soot blower system. The warm-up procedure will end, if a temperature of
250°C is achieved downstream the last soot blower. Under consideration of the ambient
conditions, the total temperature increase of the pipes will be 223°C. (250°C – 27°C = 223°C)
The total warm-up flow of the system which is necessary to increase the pipe material
temperature up to 250°C is 3,2 kg/s, as per Figure 6. This warm-up will be completed within
120 minutes.

Page: 19 / 54
Design Report Steam
N-100141-S-H__-IB07-00011
NTPC DRG NO.
N-100141
0306-102-PVM-U-0951
Warm up for Bundle Sootblowers
Load Case
Description Units
100% 25%
BMCR BMCR
bar a 53,28 15,56
PRDS Inlet Pressure kg/cm²
54,33 15,87
a
PRDS Inlet Temperature °C 332,2 343,3
PRS Inlet Enthalpy kJ/kg 3011,5 3132,3
bar a 22,00 13,27

PRDS outlet Pressure kg/cm²
22,43 13,53
a
PRDS outlet Temperature °C 297,0 341,1
Specific Heat capacity Cp (Steel) J/kg.K 514,0 514,0
For warm up control valve 1 0HCB23 AA001
Heat up from °C 27,0 27,0
Heat up to °C 250,0 250,0
Time period min 120 120
Heat quantity kW 571,75 571,75
bar a 20,92 11,08

Pressure at temperature measurement point kg/cm²
21,33 11,30
a
Temperature at Throttle Valve outlet °C 250,0 250,0
Enthalpy Throttle Valve outlet kJ/kg 2899,2 2939,2
Design Mass Flow for 1 0HCB23 AA001 kg/s 3,18 2,08
Figure 6: Overview of Warm-up design mass flow for Bundle Soot Blowers

Page: 20 / 54
Design Report Steam
N-100141-S-H__-IB07-00011
NTPC DRG NO.
N-100141
0306-102-PVM-U-0951
Sample Calculation for the mass of steel piping considered in the warm-up calculation.
Considering the main piping from tapping point up to PRS, mass of steel piping to be warmed
up is as follows,
Pipe Length m 46.4

OD mm 219.1
Thickness mm 15.09
ID mm 188.92
Specific steel density kg/m³ 7860
Mass of steel Tonnes 3.5
Note: The mass of steel for the main piping from tapping point up to PRS is given in the above
sample calculation. Similarly, when all the piping in the soot blower system is considered, the
total mass of steel calculated is 36 Tonnes
3.5 Orifice Bundle Sootblower System (Hot Standby)
Following boundary conditions are considered for calculating the hot stand by mass flow of the
orifice.
• The specific insulating heat losses are valued with 100 W/m².
• Dryness fraction is 1 kg/kg
• The heat transferred from the medium to the Sootblower piping is given by the
temperature drop of the medium to 250°C downstream of the pressure reducing
station.

Page: 21 / 54
Design Report Steam
N-100141-S-H__-IB07-00011
NTPC DRG NO.
N-100141
0306-102-PVM-U-0951
3.5.2 Design Orifice Bundle Soot Blower
The soot blower system will be pre-warmed as described in chapter 3.4. After achieving 250°C
after the last soot blower, the initiation of the soot blowing process will start. The temperature
of the soot blower pipes will be maintained by a fixed hot standby amount via orifice, when the
warm-up control valve is closed.
As per Figure 7 the calculated value of the hot stand by is shown for the maximum load case
at 100%BMCR and for the Benson minimum load. The temperature must be maintained in the
pipes to avoid thermal shocks. Therefore the total heat losses of the pipes will be
compensated by the soot blower medium. Under consideration of the specific insulation heat
losses, the total heat loss of the soot blower pipes is as given in the Figure 7
The medium specific heat capacity is related to the parameters downstream the pressure
reducing station and a dryness fraction of 1 kg/kg (100% steam). As already described, the
medium temperature difference is related to the outlet temperature downstream pressure
reducing station and the minimum allowable medium temperature. As per chapter 3.4.2, the
limitation of the minimum allowable medium temperature is 250°C.
The amount of the hot stand by mass flow is calculated by dividing the total heat losses of the
pipes through the specific heat capacity and temperature drop of the medium, as shown in
following equation:

Page: 22 / 54
Design Report Steam
N-100141-S-H__-IB07-00011
NTPC DRG NO.
N-100141
0306-102-PVM-U-0951
Hot Standby for Bundle Sootblowers
Load Case
Description Units
100% BMCR 35% BMCR
bar a 53,35 21,20

54,40 21,62
a
bar a 22,00 20,54

22,43 20,95
a
Formula Q = m*(h2-h1)
For Orifice 1 0HCB23 BP001
Minimum Temperature at O/L °C 250,0 250,0
Total Heat Loss , Q kW 123,8 123,8
bar a 21,87 20,38

22,30 20,78
a
Enthalpy at Throttle Valve outlet kJ/kg 2895,1 2901,6
Mass Flow rate kg/s 1,06 0,60
Design Mass Flow for 1 0HCB23 BP001 kg/s 1,2 1,2
Figure 7: Design Criteria Orifice (Hot Stand By) for Heating Surface Soot Blowers

Page: 23 / 54
Design Report Steam
N-100141-S-H__-IB07-00011
NTPC DRG NO.
N-100141
0306-102-PVM-U-0951
Sample Calculation for total heat loss, Q in kW considered in the hot standby calculation.
Considering the main Piping from tapping point up to PRS for heat loss,
Pipe Length m 46.4

OD mm 219.1
Thickness mm 15.09
Insulation Thickness mm 150
Total OD mm 519.1
Area m² 75.7
Specific Heat Loss W/m² 100
Total Heat Loss kW 7.57
Note: The total heat loss in the main piping from tapping point up to PRS is given in the above
sample calculation. Similarly, when all the piping in the soot blower system is considered, the
total heat loss calculated is 123.8 kW

Page: 24 / 54
Design Report Steam
N-100141-S-H__-IB07-00011
NTPC DRG NO.
N-100141
0306-102-PVM-U-0951
3.1 Pressure Drop

Table: 1 – Pressure loss for SB Warm up piping (Sootblower out of operation)
100% BMCR (Warm-up) 25% BMCR (Warm-up)

Pressures Pressures
Description
54.50 54.42 0.08 16.21 16.19 0.02
2 Nipples
54.42 54.42 0.00 16.19 16.18 0.01

54.42 54.41 0.01 16.18 16.16 0.03

54.41 54.39 0.02 16.16 16.07 0.09

54.39 54.36 0.02 16.07 15.97 0.09

54.36 54.33 0.04 15.97 15.87 0.11
Pressure Drop PRS

31.89 31.89 2.33 2.33

22.43 22.43 0.00 13.53 13.53 0.00

22.43 22.41 0.02 13.53 13.49 0.04

22.41 22.40 0.01 13.49 13.47 0.02
4 Flow meter
22.40 22.32 0.08 13.47 13.31 0.15

22.32 22.31 0.01 13.31 13.30 0.01
6 T-Piece
22.31 22.30 0.01 13.30 13.29 0.01

22.30 22.28 0.03 13.29 13.24 0.05

22.28 22.21 0.07 13.24 13.11 0.13

22.21 21.57 0.64 13.11 11.81 1.30

21.57 21.33 0.24 11.81 11.30 0.51

21.33 20.37 0.96 11.30 9.26 2.04

20.37 20.36 0.01 9.26 9.23 0.03
13 T-Piece
20.36 20.12 0.24 9.23 8.60 0.62

20.12 20.06 0.07 8.60 8.42 0.18

system

Page: 25 / 54
Design Report Steam
N-100141-S-H__-IB07-00011
NTPC DRG NO.
N-100141
0306-102-PVM-U-0951
Table: 2 – Pressure loss for SB Hot standby Sootblower piping (Sootblower out of operation)
100% BMCR (Hot Standby) 25% BMCR (Hot Standby)

Pressures Pressures
Description
54.50 54.42 0.08 21.70 21.67 0.03
2 Nipples
54.42 54.42 0.00 21.67 21.66 0.00

54.42 54.42 0.00 21.66 21.66 0.00

54.42 54.41 0.00 21.66 21.65 0.01

54.41 54.41 0.00 21.65 21.64 0.01

54.41 54.40 0.01 21.64 21.62 0.02
Pressure Drop PRS

31.96 31.96 0.67 0.67

22.43 22.43 0.00 20.95 20.95 0.00

22.43 22.43 0.00 20.95 20.94 0.00

22.43 22.43 0.00 20.94 20.94 0.00
4 Flow meter
22.43 22.42 0.01 20.94 20.93 0.02

22.42 22.42 0.00 20.93 20.93 0.00
6 T-Piece
22.42 22.42 0.00 20.93 20.93 0.00

22.42 22.41 0.01 20.93 20.92 0.01

22.41 22.40 0.01 20.92 20.91 0.01

22.40 22.33 0.07 20.91 20.82 0.09

22.33 22.30 0.03 20.82 20.78 0.03

22.30 22.17 0.13 20.78 20.63 0.15

22.17 22.17 0.00 20.63 20.63 0.00
13 T-Piece
22.17 22.14 0.03 20.63 20.60 0.04

22.14 22.14 0.01 20.60 20.59 0.01

system

Page: 26 / 54
Design Report Steam
N-100141-S-H__-IB07-00011
NTPC DRG NO.
N-100141
0306-102-PVM-U-0951
3.2 Warm-up Control Valve for Furnace Wall Blower System
Please refer to chapter 3.4. Same procedure is considered in the calculation for the Furnace
Soot Blower.
Warm-up for Furnace Wallblowers
Load Case
Description Units
100% 25%
BMCR BMCR
bar a 53,28 15,56
54,33 15,87
a
bar a 22,00 13,08

22,43 13,34
a
Heat up to °C 250,0 250,0
bar a 21,82 12,66

22,25 12,91
a
Throttle Valve Outlet Temperature °C 250,0 250,0
Enthalpy Throttle Valve outlet kJ/kg 2895,29 2933,15
Design Mass Flow for 1 0HCB43 AA001 chosed kg/s 0,8 0,8
Figure 8: Overview of warm-up design mass flow for Furnace Wall Blowers

Page: 27 / 54
Design Report Steam
N-100141-S-H__-IB07-00011
NTPC DRG NO.
N-100141
0306-102-PVM-U-0951
3.3 Orifice Furnace Wall Blower System (Hot standby)

Please refer to chapter 3.5. Same procedure is considered in the calculation for the Furnace
Soot Blower.
Hot Standby for Furnace Wallblowers
Load Case
Description Units
100% BMCR 35% BMCR
bar a 53,35 21,20

54,40 21,62
a
bar a 22,00 20,54

22,43 20,95
a
PRDS outlet Temperature °C 296,7 337
bar a 22,01 20,54

22,44 20,95
a
Enthalpy at Trottle Valve outlet kJ/kg 2894,5 2900
Design Mass Flow for 1 0HCB43 BP001 kg/s 0,4 0,4
Figure 9: Design Criteria of Orifice (Hot stand by) for Furnace Wall Blowers
Sample calculation Orifice:

Page: 28 / 54
Design Report Steam
N-100141-S-H__-IB07-00011
NTPC DRG NO.
N-100141
0306-102-PVM-U-0951
3.4 Pressure Drop

Table: 1 – Load Cases for Hot standby Wall blower piping
100% BMCR (Hot Standby) 35% BMCR (Hot Standby)
Pressures Pressures
Description
54.50 54.42 0.08 21.70 21.67 0.03
2 Nipples
54.42 54.42 0.00 21.67 21.66 0.00

54.42 54.42 0.00 21.66 21.66 0.00

54.42 54.41 0.00 21.66 21.65 0.01

54.41 54.41 0.00 21.65 21.64 0.01

54.41 54.40 0.01 21.64 21.62 0.02
Pressure Drop PRS 31.96 31.96 0.67 0.67
1 PRDS to isolation valve

22.43 22.43 0.00 20.95 20.95 0.00

22.43 22.43 0.00 20.95 20.95 0.00

22.43 22.43 0.00 20.95 20.94 0.00
4 Flow Meter
22.43 22.42 0.01 20.94 20.93 0.02

22.42 22.42 0.00 20.93 20.93 0.00
6 T-Piece
22.42 22.42 0.00 20.93 20.93 0.00
7 T-Piece to WB main piping

22.42 22.43 -0.02 20.93 20.94 -0.02
8 T-Piece
22.43 22.43 0.00 20.94 20.94 0.00

22.43 22.44 0.00 20.94 20.94 0.00

22.44 22.43 0.00 20.94 20.94 0.00
11 Isolation valve to WB drain line

22.43 22.44 -0.01 20.94 20.94 0.00
12 WB drain line to throttle valve

22.44 22.44 0.00 20.94 20.94 0.00

22.44 22.32 0.13 20.94 20.79 0.15
14 WB drain line TV to T-Piece

22.32 22.32 0.00 20.79 20.79 0.00
15 T-Piece
22.32 22.31 0.00 20.79 20.79 0.00
16 T-Piece to control valve

22.31 22.31 0.01 20.79 20.78 0.01
0.13 32.20 0.17 0.92
PRS/Total Pressure drop

Page: 29 / 54
Design Report Steam
N-100141-S-H__-IB07-00011
NTPC DRG NO.
N-100141
0306-102-PVM-U-0951
Table: 2 - Load Cases for warm-up Wall blower piping

100% BMCR (Warm-up) 25% BMCR (Warm-up)
Pressures Pressures
Description
54.50 54.42 0.08 16.21 16.19 0.02
2 Nipples
54.42 54.42 0.00 16.19 16.18 0.01

54.42 54.41 0.01 16.18 16.16 0.03

54.41 54.39 0.02 16.16 16.07 0.09

54.39 54.36 0.02 16.07 15.97 0.09

54.36 54.33 0.04 15.97 15.87 0.11
1 PRDS to isolation valve

22.43 22.43 0.00 13.34 13.34 0.00

22.43 22.41 0.02 13.34 13.29 0.05

22.41 22.40 0.01 13.29 13.27 0.02
4 Flow Meter
22.40 22.32 0.08 13.27 13.12 0.15

22.32 22.31 0.01 13.12 13.10 0.01
6 T-Piece
22.31 22.31 0.01 13.10 13.09 0.01
7 T-Piece to WB main piping

22.31 22.32 -0.02 13.09 13.10 -0.01
8 T-Piece
22.32 22.32 0.00 13.10 13.10 0.00

22.32 22.32 0.00 13.10 13.10 0.00

22.32 22.31 0.01 13.10 13.08 0.02
11 Isolation valve to WB drain line

22.31 22.26 0.06 13.08 12.92 0.16
12 WB drain line to throttle valve

22.26 22.25 0.00 12.92 12.91 0.01

22.25 21.74 0.51 12.91 11.93 0.98
14 WB drain line TV to T-Piece

21.74 21.74 0.00 11.93 11.93 0.00
15 T-Piece
21.74 21.73 0.01 11.93 11.91 0.02
16 T-Piece to control valve

21.73 21.70 0.03 11.91 11.85 0.06
0.73 32.80 1.48 4.36

Page: 30 / 54
Design Report Steam
N-100141-S-H__-IB07-00011
NTPC DRG NO.
N-100141
0306-102-PVM-U-0951
Table: 3 - Load Cases for SB operating conditions:
100% TMCR 80% MCR 60% MCR 50% MCR

Pressures Pressures Pressures Pressures
S. Inlet Outlet ∆p Inlet Outlet ∆p Inlet Outlet ∆p Inlet Outlet ∆p
Description
No. kg/cm² kg/cm² kg/cm² kg/cm² kg/cm² kg/cm² kg/cm² kg/cm² kg/cm² kg/cm² kg/cm² kg/cm²

54.10 54.01 0.08 41.20 41.13 0.06 31.41 31.36 0.05 26.50 26.46 0.04
2 Nipples
54.01 54.01 0.01 41.13 41.12 0.01 31.36 31.34 0.02 26.46 26.44 0.02
54.01 53.98 0.03 41.12 41.09 0.03 31.34 31.30 0.04 26.44 26.39 0.05
53.98 53.89 0.09 41.09 40.97 0.12 31.30 31.14 0.16 26.39 26.20 0.19
53.89 53.80 0.09 40.97 40.85 0.12 31.14 30.98 0.16 26.20 26.00 0.20
53.80 53.70 0.10 40.85 40.72 0.14 30.98 30.80 0.18 26.00 25.78 0.22
Total Pressure Drop

upstream PRS
31.26 31.26 18.28 18.28 8.36 8.36 3.35 3.35

22.43 22.43 0.00 22.43 22.43 0.00 22.43 22.43 0.00 22.43 22.43 0.00
22.43 22.35 0.09 22.43 22.34 0.09 22.43 22.34 0.09 22.43 22.34 0.09
22.35 22.31 0.04 22.34 22.30 0.04 22.34 22.30 0.04 22.34 22.29 0.05
4 Flow meter
22.31 22.01 0.30 22.30 21.99 0.31 22.30 21.98 0.32 22.29 21.97 0.32
22.01 21.99 0.02 21.99 21.97 0.02 21.98 21.95 0.02 21.97 21.95 0.02
6 T-Piece
21.99 21.96 0.03 21.97 21.94 0.03 21.95 21.92 0.03 21.95 21.92 0.03
21.96 21.87 0.09 21.94 21.85 0.09 21.92 21.83 0.10 21.92 21.82 0.10
21.87 21.62 0.25 21.85 21.59 0.26 21.83 21.56 0.27 21.82 21.55 0.27
21.62 19.11 2.50 21.59 18.98 2.61 21.56 18.85 2.71 21.55 18.80 2.75
19.11 19.08 0.03 18.98 18.94 0.04 18.85 18.81 0.04 18.80 18.76 0.04
11 Throttle valve
19.08 19.03 0.05 18.94 18.89 0.05 18.81 18.76 0.05 18.76 18.71 0.05
19.03 19.03 0.00 18.89 18.89 0.00 18.76 18.76 0.00 18.71 18.71 0.00
13 T-Piece
19.03 19.00 0.04 18.89 18.85 0.04 18.76 18.72 0.04 18.71 18.67 0.04
19.00 18.99 0.01 18.85 18.84 0.01 18.72 18.71 0.01 18.67 18.66 0.01
Total Pressure Drop

3.45 35.11 3.59 22.35 3.73 12.70 3.77 7.84
downstream PRS

Page: 31 / 54
Design Report Steam
N-100141-S-H__-IB07-00011
NTPC DRG NO.
N-100141
0306-102-PVM-U-0951
Table: 4 - Load Cases for SB design conditions (40% mass flow):
Design Conditions
100% BMCR 35% BMCR
Pressures Pressures
Description
54.50 54.42 0.08 21.70 21.67 0.03
2 Nipples
54.42 54.42 0.00 21.67 21.66 0.01
54.42 54.41 0.01 21.66 21.64 0.02
54.41 54.39 0.02 21.64 21.59 0.06
54.39 54.36 0.02 21.59 21.53 0.06
54.36 54.32 0.04 21.53 21.46 0.07
Pressure Drop PRS
30.06 30.06 4.08 4.08
24.27 24.27 0.00 17.38 17.38 0.00
24.27 24.25 0.02 17.38 17.35 0.03
24.25 24.24 0.01 17.35 17.34 0.01
4 Flow meter
24.24 24.16 0.08 17.34 17.24 0.10
24.16 24.16 0.00 17.24 17.23 0.01
6 T-Piece
24.16 24.15 0.01 17.23 17.22 0.01
24.15 24.12 0.03 17.22 17.19 0.03
24.12 24.06 0.06 17.19 17.11 0.08
24.06 23.47 0.59 17.11 16.32 0.79
23.47 23.45 0.02 16.32 16.28 0.05
23.45 23.33 0.12 16.28 16.08 0.19
23.33 23.33 0.00 16.08 16.08 0.00
13 T-Piece
23.33 23.30 0.03 16.08 16.04 0.05
23.30 23.29 0.01 16.04 16.02 0.01
0.98 31.22 1.36 5.68

Page: 32 / 54
Design Report Steam
N-100141-S-H__-IB07-00011
NTPC DRG NO.
N-100141
0306-102-PVM-U-0951
Table: 5 - Load Cases for SB operating conditions (40% mass flow):

Operation Conditions
100% TMCR 80% MCR 60% MCR 50% MCR
Description
54.10 54.02 0.07 41.20 41.13 0.06 31.41 31.36 0.05 26.50 26.46 0.04
2 Nipples
54.02 54.02 0.00 41.13 41.13 0.00 31.36 31.36 0.00 26.46 26.46 0.00
54.02 54.02 0.01 41.13 41.13 0.01 31.36 31.35 0.01 26.46 26.45 0.01
54.02 54.00 0.01 41.13 41.11 0.02 31.35 31.32 0.03 26.45 26.42 0.03
Isolation valve
5
(motorised) 54.00 53.99 0.01 41.11 41.09 0.02 31.32 31.30 0.03 26.42 26.39 0.03
Connecting pipe upto
6
PRS 53.99 53.96 0.02 41.09 41.06 0.03 31.30 31.26 0.03 26.39 26.35 0.04
Pressure Drop PRS
31.53 31.53 18.63 18.63 8.83 8.83 3.91 3.91
22.43 22.43 0.00 22.43 22.43 0.00 22.43 22.43 0.00 22.43 22.43 0.00
22.43 22.42 0.01 22.43 22.42 0.01 22.43 22.42 0.01 22.43 22.42 0.01
Isolation valve to flow
3
meter 22.42 22.41 0.01 22.42 22.41 0.01 22.42 22.41 0.01 22.42 22.41 0.01
4 Flow meter
22.41 22.37 0.05 22.41 22.36 0.05 22.41 22.36 0.05 22.41 22.36 0.05
Connecting pipe to T-
5
Piece 22.37 22.36 0.00 22.36 22.36 0.00 22.36 22.36 0.00 22.36 22.36 0.00
6 T-Piece
22.36 22.36 0.00 22.36 22.36 0.00 22.36 22.35 0.00 22.36 22.35 0.00
T-Piece to isolation
7
valve 22.36 22.34 0.02 22.36 22.34 0.02 22.35 22.34 0.02 22.35 22.34 0.02
22.34 22.30 0.04 22.34 22.30 0.04 22.34 22.29 0.04 22.34 22.29 0.04
Isolation valve to SB
9
drain line 22.30 21.94 0.36 22.30 21.92 0.38 22.29 21.90 0.39 22.29 21.90 0.39
SB drain line to throttle
10
valve 21.94 21.92 0.03 21.92 21.89 0.03 21.90 21.87 0.03 21.90 21.87 0.03
Throttle valve
11 (Temperature
measurement) 21.92 21.79 0.13 21.89 21.76 0.14 21.87 21.73 0.14 21.87 21.73 0.14
SB drain line TV to T-
12
Piece 21.79 21.78 0.00 21.76 21.76 0.00 21.73 21.73 0.00 21.73 21.73 0.00
13 T-Piece
21.78 21.75 0.03 21.76 21.72 0.03 21.73 21.70 0.03 21.73 21.69 0.03
21.75 21.74 0.01 21.72 21.72 0.01 21.70 21.69 0.01 21.69 21.68 0.01
Total Pressure Drop
downstream PRS/Total 0.69 32.35 0.72 19.48 0.75 9.72 0.75 4.82
Pressure drop

Page: 33 / 54
Design Report Steam
N-100141-S-H__-IB07-00011
NTPC DRG NO.
N-100141
0306-102-PVM-U-0951
Table: 6 - Load Cases for SB Hot Standby & Warm-up (40% PRS Load):
100% BMCR- Hot Standby 25% BMCR- Warm- up

Pressures Pressures
Description
54.50 54.42 0.08 16.21 16.19 0.02
2 Nipples
54.42 54.42 0.00 16.19 16.18 0.01
54.42 54.42 0.00 16.18 16.16 0.03
54.42 54.41 0.00 16.16 16.07 0.09
54.41 54.41 0.00 16.07 15.97 0.09
54.41 54.40 0.01 15.97 15.87 0.11
Pressure Drop PRS
31.96 31.96 2.33 2.33
22.43 22.43 0.00 13.53 13.53 0.00
22.43 22.43 0.00 13.53 13.49 0.04
22.43 22.43 0.00 13.49 13.47 0.02
4 Flow meter
22.43 22.42 0.01 13.47 13.31 0.15
22.42 22.42 0.00 13.31 13.30 0.01
6 T-Piece
22.42 22.42 0.00 13.30 13.29 0.01
22.42 22.41 0.01 13.29 13.24 0.05
22.41 22.40 0.01 13.24 13.11 0.13
22.40 22.33 0.07 13.11 11.81 1.30
22.33 22.30 0.03 11.81 11.30 0.51
22.30 22.17 0.13 11.30 9.26 2.04
22.17 22.17 0.00 9.26 9.23 0.03
13 T-Piece
22.17 22.14 0.03 9.23 8.60 0.62
22.14 22.14 0.01 8.60 8.42 0.18
0.30 32.37 5.11 7.80

Page: 34 / 54
Design Report Steam
N-100141-S-H__-IB07-00011
NTPC DRG NO.
N-100141
0306-102-PVM-U-0951
Table: 7 - Load Cases for WB operating conditions:

100% TMCR 80% MCR 60% MCR 50% MCR
Description
1 Reheater I/L Header 54.10 54.02 0.07 41.20 41.13 0.06 31.40 31.35 0.05 26.50 26.46 0.04
2 Nipples 54.02 54.01 0.01 41.13 41.12 0.01 31.35 31.33 0.02 26.46 26.44 0.02
3 From RH tapping point 54.01 53.99 0.03 41.12 41.09 0.03 31.33 31.29 0.04 26.44 26.39 0.05
4 Isolation valve (manual) 53.99 53.90 0.09 41.09 40.97 0.12 31.29 31.13 0.16 26.39 26.20 0.19
5 Isolation valve (motorised) 53.90 53.81 0.09 40.97 40.85 0.12 31.13 30.97 0.16 26.20 26.00 0.20
6 Connecting pipe upto PRS 53.81 53.71 0.10 40.85 40.72 0.14 30.97 30.78 0.18 26.00 25.78 0.22
Total Pressure Drop

31.27 31.27 18.28 18.28 8.35 8.35 3.35 3.35 8.35 8.35
upstream PRS
1 PRS to isolation valve 22.43 22.43 0.00 22.43 22.43 0.00 22.43 22.43 0.00 22.43 22.43 0.00
3 Isolation valve to flow meter 22.35 22.31 0.04 22.34 22.30 0.04 22.34 22.30 0.04 22.34 22.30 0.04
4 Flow meter 22.31 22.01 0.30 22.30 22.00 0.30 22.30 21.99 0.31 22.30 21.98 0.32
5 Connecting pipe to T-Piece 22.01 21.99 0.02 22.00 21.98 0.02 21.99 21.96 0.02 21.98 21.96 0.02
6 T-Piece 21.99 21.96 0.02 21.98 21.95 0.03 21.96 21.94 0.03 21.96 21.93 0.03
7 T-Piece to isolation valve 21.96 21.98 -0.01 21.95 21.97 -0.01 21.94 21.95 -0.01 21.93 21.94 -0.01
Isolation valve to SB drain

9 21.98 21.98 0.00 21.96 21.96 0.00 21.95 21.95 0.00 21.94 21.94 0.00
line
10 SB drain line to throttle valve 21.98 21.95 0.02 21.96 21.94 0.02 21.95 21.92 0.02 21.94 21.92 0.02
11 Throttle valve 21.95 21.75 0.20 21.94 21.73 0.21 21.92 21.71 0.22 21.92 21.69 0.22
12 SB drain line TV to T-Piece 21.75 21.75 0.00 21.73 21.73 0.00 21.71 21.71 0.00 21.69 21.69 0.00
13 T-Piece 21.75 21.62 0.13 21.73 21.60 0.13 21.71 21.57 0.14 21.69 21.55 0.14
14 T-Piece to Control Valve 21.62 21.62 0.00 21.60 21.60 0.00 21.57 21.57 0.00 21.55 21.55 0.00
15 T-Piece 21.62 21.61 0.00 21.60 21.60 0.00 21.57 21.56 0.00 21.55 21.55 0.00
16 T-Piece to control valve 21.61 21.61 0.01 21.60 21.59 0.01 21.56 21.56 0.01 21.55 21.54 0.01
Total Pressure Drop

0.83 32.49 0.85 19.61 0.88 9.84 0.89 4.96 0.88 9.84
downstream PRS

Page: 35 / 54
Design Report Steam
N-100141-S-H__-IB07-00011
NTPC DRG NO.
N-100141
0306-102-PVM-U-0951
3.5 Diagram for pressure downstream Pressure Reducing Station
The given graph represents the pressure downstream the pressure reducing station. It
describes the possibility of soot blowing process at part loads. The soot blower pre-warming
will take place at 25% BMCR and the soot blowing process starts at 35% BMCR-load. The full
soot blowing pressure will be achieved at part loads over 45% BMCR, as shown in the graph.

Page: 36 / 54
Design Report Steam
N-100141-S-H__-IB07-00011
NTPC DRG NO.
N-100141
0306-102-PVM-U-0951
3.6 Velocity in soot blower pipes
max.
Velocity
KKS To Po *) Ts Ps avaible Density Di Velocities
°C bara °C barg m/s kg/m³ mm m/s
Common Sootblower
Line
HCB10 BR010 332,4 53,4 358,0 68,7 40,0 21,7 188,8 12
HCB10 BR020 332,1 22,0 320,0 68,7 40,0 7,3 236,5 20
Tube Bank Sootblower
HCB21 BR010 296,1 21,2 320,0 68,7 40,0 8,6 115,9 34
HCB22 BR010 296,1 21,2 320,0 68,7 40,0 8,6 115,9 34

HCB23 BR010 292,7 18,6 320,0 68,7 90,0 7,5 115,9 41
HCB23 BR410 292,7 18,6 320,0 68,7 90,0 7,5 73,7 38
Furnace Sootblower
HCB30 BR010 296,5 21,6 320,0 68,7 40,0 8,7 188,9 5
HCB41 BR010 296,5 21,6 320,0 68,7 40,0 8,7 97,2 11
HCB42 BR010 296,5 21,6 320,0 68,7 40,0 8,7 97,2 10
HCB43 BR010 296,1 21,2 320,0 68,7 90,0 8,6 97,2 13
HCB43 BR410 294,8 20,2 320,0 68,7 90,0 8,2 49,2 26

Page: 37 / 54
Design Report Steam
N-100141-S-H__-IB07-00011
NTPC DRG NO.
N-100141
0306-102-PVM-U-0951
4 Soot Blower Valves Air Pre-Heater

Following chapters represent the design criteria of air heater soot blower valves. Design
Criteria for Pressure Reducing Stations, Safety Valve, Control Valve and Throttle Valves are
given. Valves should be able to realize high capacities at low pressure drop and low capacities
at high pressure drop. Therefore additional load cases in the corresponding documents, if
necessary, are given for supplier.
4.1 Pressure Reducing Station RAPH
4.1.1 Demands
As per technical specification section VI; Part A; sub section III A1; clause no. 1.09.03 two
100% redundant pressure reducing stations should be considered for the regenerative air
heater soot blower system in total. The leakage class of the station is “IV” and the maximum
noise with sound isolation in 1 meter distance is 85 dB(A) as per specification.
Extracted steam of the RH2 inlet headers will be reduced to required soot blower pressure
values by the Pressure Reducing Station.
The following document should be considered in regard to this chapter: “Design Data Sheet
of Air Heater Sootblower Control Valves (9571-102-PVI-Y-0688/0360-102-PVI-Y-0689)”
The following data represents the design criteria of the reducing stations. The chosen mass
flow is based on data given by the soot blower supplier. Design parameters are based on the
working conditions. The failure of Control Valve and Reheater Safety Valve at a time is not
considered in the calculated observation.

Page: 38 / 54
Design Report Steam
N-100141-S-H__-IB07-00011
NTPC DRG NO.
N-100141
0306-102-PVM-U-0951
Following mass flows are considered for the calculations:
• Steam mass flow required for air heater soot blower: 1,61 kg/sec
• Steam mass flow required for warm up the Soot Blower System: 1,3 kg/sec
• Maximum 1 RAH Soot Blower in operation
Total mass flow of the pressure reducing station (including hot stand by):
1,61 + 0,4 = 2,01 kg/sec
The operating temperatures and pressures upstream and downstream the pressure reducing
stations are given in the “Design data sheet steam soot blower control valves”. The total soot
blower mass flow, including the hot stand by, is considered from 100%BMCR up to Benson
minimum load 35%BMCR. The total warm up mass flow is considered for 25%BMCR as the
initiation of warm up will start at this load case.
4.2 Soot blower Safety Valve RAPH
4.2.1 Demands
As per technical specification section-VI part-A sub-section-III:A1 clause No. 1.10.04 the
safety valve downstream of the steam pressure reducing station shall be designed for a flow
corresponding to the pressure control valve fully open condition and the upstream main
steam/cold reheat pressure being maximum expected.

Page: 39 / 54
Design Report Steam
N-100141-S-H__-IB07-00011
NTPC DRG NO.
N-100141
0306-102-PVM-U-0951
Spring loaded safety valve on the air heater soot blower line protects the system against
excess pressure. One safety valve downstream the pressure reducing station will be provided.
The set pressure of the safety valve is equivalent to the design pressure of the pipe.
4.2.3 Design
In the first calculation part the Kv-value of the pressure reducing station is calculated, as
represented in Figure 10. The input data for Kv-value calculation is the 35% BMCR load case.
An additional margin of is considered for the Kv-Value of the pressure reducing station.
In the next calculation part, the chosen Kv-value is used to calculate the flow downstream the
pressure reducing station at maximum operating condition. This flow is taken for designing the
safety valve of the soot blower RAPH
Design criteria such as mass flow, temperature and pressure are given in the document
“Design Data Sheet of Air Heater Sootblower Safety Valves (9571-102-PVI-Y-0049/0360-
102-PVI-Y-0049)”. Figure 10 and Figure 11 represents the calculated Kv-Value of the
pressure reducing station and the design mass flow capacity for the safety valve.
Kv-value calculation by considering the mass flow in chapter 4.1.2.

kg/s 2,01
Pressure Reducing Station maximum Flow rate at 35% BMCR load inlet
kg/h 7236,0
Pressure Reducing Station Temperature inlet at 35% BMCR load °C 501,1
bar(a) 20,6
kg/cm²(a) 21,0
Pressure Reducing Station inlet enthalpy kJkg(a) 3469,9
bar 4,0
Pressure Reducing Station differential pressure
kg/cm² 4,1
bar(a) 16,6
Pressure Reducing Station outlet pressure
kg/cm²(a) 16,9
Specific Volume downstream Control Valve m³/kg 0,2
=> Kv-value m³/h 52,6
Kvs chosen m³/h 60
Figure 10: Overview of Kv - value of the pressure reducing station

Page: 40 / 54
Design Report Steam
N-100141-S-H__-IB07-00011
NTPC DRG NO.
N-100141
0306-102-PVM-U-0951
Mass flow calculation under consideration of the chosen Kv-value.
bar(a) 69,7
kg/cm²(a) 71,1
bar(a) 30,0
Pressure Reducing Station set pressure SV
kg/cm²(a) 30,6
bar(a) 30,0
=> Pressure Reducing Station outlet pressure
kg/cm²(a) 30,6
Pressure Reducing Station inlet temperature °C 489,2
Pressure Reducing Station inlet enthalpy kJ/kg 3385,3
Pressure Reducing Station outlet specific volume m³/kg 0,111
=> Pressure Reducing Station outlet flow m³/s 1,11
Mass Flow calculated kg/s 9,97
Mass Flow chosen kg/s 10,03
t/h 36,10
Figure 11: Calculation of mass flow for RAPH soot blower safety valves
An example for Kv-value and mass flow calculation is given in chapter 3.2.4
4.3 Throttle Valves RAPH
One throttle valve in each line will be provided. During commissioning the warm keeping mass
flow to both soot blowing lines will be adjusted manually, in order to equalize the temperatures
downstream the soot blowers. As written in chapter 4.1.2 the total steam mass flow required
for hot-stand by is 0,4 kg/sec. for the Air Heater soot blower system. Each line will be charged
with half of the hot standby flow. The described procedure is defined as “normal case” during
the soot blower operation mode in the “Design Data Sheet of Air Heater Soot blower Throttle
Valves”.
During startup of the boiler, the RAPH soot blower system will be pre-warmed. The pre
warming process will start at 25%BMCR load as described in the “Process Description Steam
Soot blower”. Thus the system will be charged with warm-up mass flow as given in chapter
4.1.2. The maximum throttle valve mass flow will be achieved during warm up of the boiler.
This case represents the “design case” in the “Design Data Sheet of Steam Soot blower
Throttle Valves”. Both the minimum and the maximum conditions are sufficient to design the
Page: 41 / 54
Design Report Steam
N-100141-S-H__-IB07-00011
NTPC DRG NO.
N-100141
0306-102-PVM-U-0951
throttle valves. No additional conditions will be incorporated, in respect of no further use for the
supplier.
Following document should be considered in regard to this chapter: Design Data Sheet of Air
Heater Sootblower Throttle Valves (9571-102-PVM-Y-0185/0360-102-PVM-Y-0185).
4.4 Warm up Control Valve RAPH
4.4.1 Demands
The complete soot blower piping shall have been warmed up as per technical specification
section-VI part-A sub section III A1 clause No. 1.09.02. Relevant information related to the
warm up process of the boiler is given in the “Process Description Steam Soot blower”.
Following document should be considered in regard to this chapter: Design Data Sheet of
Steam Sootblower Control Valves (9571-102-PVI-Y-0688/0360-102-PVI-Y-0688).
During start up, the warm-up control valve is fully opened and steam is led to the start-up flash
tank. By reaching a defined pressure downstream of the pressure reducing station and a
defined temperature downstream of the last steam blowers, the warm-up CV is closed and the
hot stand-by is maintained via the orifice in the bypass.
The warm-up control valve will be charged by the maximum mass flow during the warm-up
procedure of the soot blower system. The warm up procedure will end, if a temperature of
320°C is achieved downstream the last soot blower. Under consideration of the ambient
conditions, the total temperature increase of the pipes will be 293°C. (320°C – 27°C = 293°C)
The total warm up amount of the system, which is required to increase the pipe material
temperature up to 293°C is 1,3 kg/s as per Figure 11. This total amount will be sufficient to
warm up the pipes of the soot blower system within 90 minutes.

Page: 42 / 54
Design Report Steam
N-100141-S-H__-IB07-00011
NTPC DRG NO.
N-100141
0306-102-PVM-U-0951
Warm-up for Air Heater Sootblowers
Load Case
Description Units
100% 25%
BMCR BMCR
bar a 52,43 15,65
53,46 15,96
a
bar a 18,00 12,40

18,35 12,65
a
Heat up to °C 320,0 320,0
bar a 17,84 12,15

18,19 12,39
a
Enthalpy CV (Drain Valve) outlet kJ/kg 2912,37 3045,99

Design Mass Flow for 1 01HCB75 AA001
kg/s 1,3 1,3
Chosed
Figure 12: Overview of warm-up design mass flow for Air Heater Soot Blowers

Page: 43 / 54
Design Report Steam
N-100141-S-H__-IB07-00011
NTPC DRG NO.
N-100141
0306-102-PVM-U-0951
4.5 Orifice RAPH Sootblower System (Hot Standby)
Following boundary conditions are done for calculating the hot stand by mass flow of the
orifice.
• The specific insulating heat losses are valued with 100 W/m².
• Dryness fraction is 1 kg/kg
• The heat transferred from the medium to the Sootblower piping is given by the
temperature drop of the medium to 320°C downstream of the pressure reducing
station.
4.5.2 Design Orifice RAPH Soot Blower
The soot blower system will be pre-warmed as described in chapter 4.4. After achieving of
320°C downstream the last soot blower, the initiation of the soot blowing process will start. The
temperature of the soot blower pipes will be maintained by a fixed hot standby flow via orifice,
when the warm-up control valve is closed.
As per Figure 11 the calculated value of the hot stand by is shown for the maximum load case
at 100%BMCR and for the Benson minimum load. The temperature must be maintained in the
pipes to avoid thermal shocks. Therefore the total heat losses of the pipes will be
compensated by the soot blower medium. Under consideration of the specific insulation heat
losses, the total heat loss of the soot blower pipes is as given in the Figure 11 “Design Criteria
of orifice”.
The medium heat specific capacity is related to the parameters downstream the pressure
reducing station and a dryness fraction of 1 kg/kg (100% steam). As already described, the
medium temperature difference is related to the outlet temperature downstream pressure
reducing station and the minimum allowable medium temperature. As per chapter 4.4, the
limitation of the minimum allowable medium temperature is 320°C.
The amount of the hot stand by mass flow is calculated by dividing the total heat losses of the
pipes through the specific heat capacity and temperature drop of the medium, as shown in
following equation:
Page: 44 / 54
Design Report Steam
N-100141-S-H__-IB07-00011
NTPC DRG NO.
N-100141
0306-102-PVM-U-0951
Sample Calculation Orifice:
Hot Standby for Air Heater Sootblowers
Load Case
Description Units
100% 35%
BMCR BMCR
bar a 52,47 20,85
53,50 21,26
a
bar a 18,00 20,06

18,35 20,46
a
bar a 18,01 20,07

18,35 20,47
a
Enthalpy at Orifice outlet kJ/kg 3075,1 3070,0
Design Mass Flow for 1 0HCB75 BP001 selected kg/s 0,4 0,4
Figure13: Design Criteria of Orifice (Hot stand by) for Air Heater Soot Blower

Page: 45 / 54
Design Report Steam
N-100141-S-H__-IB07-00011
NTPC DRG NO.
N-100141
0306-102-PVM-U-0951
Table: 1 - Load Cases for AH SB hot standby (Blower out of operation):
100% BMCR 35% BMCR

Pressures Pressures
Inlet Outlet ∆p Inlet Outlet ∆p
S.No. Description
kg/cm² kg/cm² kg/cm² kg/cm² kg/cm² kg/cm²
1 Reheater 2 I/L Header 53.60 53.52 0.08 21.30 21.27 0.03
2 Nipples 53.52 53.52 0.00 21.27 21.27 0.00
3 RH 2 I/L Header to T-Piece 53.52 53.52 0.00 21.27 21.27 0.00
4 T-Piece 53.52 53.52 0.00 21.27 21.27 0.00
5 T-Piece to Isolation Valve 53.52 53.50 0.02 21.27 21.26 0.01
6 Isolation Valve (Manual) 53.50 53.50 0.00 21.26 21.26 0.00
7 Isolation Valve (Motorized) 53.50 53.50 0.00 21.26 21.26 0.00
8 Isolation valve to PRS 53.50 53.50 0.00 21.26 21.26 0.00
1 PRDS to Isolation Valve 18.35 18.35 0.00 20.45 20.45 0.00
2 Isolation valve (Manual) 18.35 18.35 0.00 20.45 20.45 0.00
3 Isolation Valve to Flow Meter 18.35 18.36 0.00 20.45 20.46 0.00
4 Flow Meter 18.36 18.35 0.00 20.46 20.45 0.00
5 Flow Meter to Common line 18.35 18.37 -0.01 20.45 20.47 -0.01
6 Common Line 18.37 18.36 0.00 20.47 20.47 0.00
7 Nipples 18.36 18.36 0.00 20.47 20.47 0.00
8 Individual piping to APH SB 18.36 18.37 -0.01 20.47 20.47 -0.01
9 Drain line upto TV 18.37 18.37 0.01 20.47 20.47 0.01
Throttle valve (Temperature
10 measurement) 18.37 18.27 0.10 20.47 20.38 0.09
11 SB drain line TV to CV 18.27 18.27 0.00 20.38 20.38 0.00
Total Pressure Drop
downstream PRS/Total
Pressure drop 0.08 35.33 0.07 0.92

Page: 46 / 54
Design Report Steam
N-100141-S-H__-IB07-00011
NTPC DRG NO.
N-100141
0306-102-PVM-U-0951
Table: 2 - Load Cases for AH SB warm-up:
100% BMCR 25% BMCR

Pressures Pressures
S.No. Description
2 Nipples 53.52 53.52 0.00 16.09 16.09 0.00
4 T-Piece 53.52 53.51 0.00 16.08 16.07 0.01
4 Flow Meter 18.32 18.27 0.05 12.59 12.52 0.07
5 Flow Meter to Common line 18.27 18.27 0.00 12.52 12.51 0.01
6 Common Line 18.27 18.26 0.01 12.51 12.50 0.01
7 Nipples 18.26 18.25 0.01 12.50 12.49 0.01
8 Individual piping to APH SB 18.25 18.26 0.00 12.49 12.48 0.00
10 measurement) 18.19 17.17 1.02 12.39 10.90 1.49
Total Pressure Drop
downstream PRS/Total Pressure
drop 1.18 36.42 1.75 5.21

Page: 47 / 54
Design Report Steam
N-100141-S-H__-IB07-00011
NTPC DRG NO.
N-100141
0306-102-PVM-U-0951
Table: 3 - Load Cases for AH SB operating conditions:
100% TMCR 80% MCR 60% MCR 50% MCR

Description
1 Reheater 2 I/L Header

53.30 53.23 0.07 40.50 40.45 0.06 30.80 30.75 0.04 26.00 25.97 0.04
2 Nipples
53.23 53.23 0.00 40.45 40.44 0.00 30.75 30.75 0.00 25.97 25.96 0.00
3 RH 2 I/L Header to T-Piece
53.23 53.23 0.00 40.44 40.44 0.00 30.75 30.74 0.01 25.96 25.96 0.01
4 T-Piece
53.23 53.23 0.00 40.44 40.44 0.01 30.74 30.74 0.01 25.96 25.95 0.01
5 T-Piece to Isolation Valve
53.23 53.20 0.03 40.44 40.41 0.02 30.74 30.71 0.03 25.95 25.92 0.03
53.20 53.19 0.01 40.41 40.39 0.02 30.71 30.68 0.03 25.92 25.89 0.03
7 Isolation valve (motorized)
53.19 53.17 0.01 40.39 40.37 0.02 30.68 30.66 0.03 25.89 25.86 0.03
8 Connecting pipe up to PRS
53.17 53.17 0.00 40.37 40.37 0.00 30.66 30.66 0.00 25.86 25.86 0.00
Total Pressure Drop

upstream PRS
34.82 34.82 22.02 22.02 12.30 12.30 7.50 7.50
1 PRS to Isolation Valve

18.35 18.35 0.00 18.35 18.35 0.00 18.35 18.35 0.00 18.35 18.35 0.00
18.35 18.34 0.02 18.35 18.34 0.02 18.35 18.34 0.02 18.35 18.34 0.02
18.34 18.31 0.03 18.34 18.31 0.03 18.34 18.31 0.03 18.34 18.31 0.03
4 Flow meter
18.31 18.25 0.06 18.31 18.25 0.06 18.31 18.25 0.06 18.31 18.25 0.06
5 Flow meter to common line
18.25 18.25 0.00 18.25 18.25 0.00 18.25 18.25 0.00 18.25 18.24 0.00
6 Common line
18.25 18.24 0.01 18.25 18.24 0.01 18.25 18.24 0.01 18.24 18.24 0.01
7 Nipples
18.24 18.23 0.01 18.24 18.23 0.01 18.24 18.23 0.01 18.24 18.23 0.01
8 Individual piping to APH SB
18.23 18.23 0.00 18.23 18.23 0.00 18.23 18.23 0.00 18.23 18.23 0.00
9 Drain line up to TV
18.23 18.23 0.01 18.23 18.23 0.01 18.23 18.22 0.01 18.23 18.22 0.01
10 Throttle valve
18.23 18.22 0.01 18.23 18.22 0.01 18.22 18.22 0.01 18.22 18.21 0.01
11 SB drain line TV to CV
18.22 18.22 0.00 18.22 18.22 0.00 18.22 18.22 0.00 18.21 18.21 0.00
Total Pressure Drop

downstream PRS
0.13 35.08 0.14 22.28 0.14 12.58 0.14 7.79

Page: 48 / 54
Design Report Steam
N-100141-S-H__-IB07-00011
NTPC DRG NO.
N-100141
0306-102-PVM-U-0951
Table: 4 - Load Cases for AH CV Design conditions:
100% BMCR 35% BMCR

Pressures Pressures
S.No. Description
2 Nipples 53.52 53.52 0.00 21.27 21.27 0.00
4 T-Piece 53.51 53.50 0.01 21.24 21.22 0.02
4 Flow Meter 18.26 18.14 0.12 16.83 16.69 0.14
5 Flow Meter to Common line 18.14 18.12 0.02 16.69 16.67 0.02
6 Common Line 18.12 18.11 0.02 16.67 16.65 0.02
7 Nipples 18.11 18.09 0.02 16.65 16.62 0.03
8 Individual piping to APH SB 18.09 18.08 0.00 16.62 16.62 0.00
10 measurement) 18.08 17.98 0.10 16.61 16.50 0.11
PRS/Total Pressure drop 0.37 35.62 0.43 4.80

Page: 49 / 54
Design Report Steam
N-100141-S-H__-IB07-00011
NTPC DRG NO.
N-100141
0306-102-PVM-U-0951
4.6 Diagram for pressure downstream Pressure Reducing Station
The given graph represents the pressure downstream the pressure reducing station. It
describes the possibility of soot blowing process at part loads. The soot blower pre-warming
will take place at 25% BMCR and the soot blowing process starts at 35% BMCR-load. The full
soot blowing pressure will be achieved at part loads over 45% BMCR, as shown in the graph.
4.7 Velocity in APH soot blower pipes
Design
KKS To Po *) Ho Ts Ps Di Velocities
°C bara kJ/kg °C barg mm m/s
Common Sootblower Line
HCB60 BR030 489,2 53,6 3404,9 500,0 68,7 139,8 7
HCB60 BR040 470,2 18,0 3404,9 500,0 68,7 173,1 13
Single Line upstream Sootblower
HCB71 BR010 470,2 18,0 3404,9 500,0 29,0 115,9 28
HCB72 BR010 470,2 18,0 3404,9 500,0 29,0 115,9 28
Line downstream Sootblower
HCB75 BR010 470,0 17,6 3404,9 500,0 29,0 73,7 29
HCB76 BR010 470,0 17,6 3404,9 500,0 29,0 73,7 29

Page: 50 / 54
Design Report Steam
N-100141-S-H__-IB07-00011
NTPC DRG NO.
N-100141
0306-102-PVM-U-0951
5 Compliance sheet
Job-No.
N-100131 / N-100141 Compliance Sheet
Codeword for
SOLAPUR / MEJA
Doc.-Title Design Report Steam Soot Blowers

N-100131-S-HA_-IB13-00001
HPE-Doc.-No.
N-100141-S-HA_-IB13-00001
9571-102-PVM-U-0951
NTPC-Doc.-No.
0306-102-PVM-U-0951
Item NTPC Comments HPE Comments
No.
Meja 19.12.2013
1. Kindly revise as per Meja Scheme Done
2. Relevant extract of FDBR may kindly be Noted

attached to this document
3. HPE to confirm the flow requirement with the Done

Soot blower supplier. The value considered
here should be higher or equal to the flow
requirement of Soot blower supplier
4. Does this imply that soot blowing will be done Correct. Additional steam extraction is avaible at 25%
only after 35% BMCR. How is the 25% BMCR BMCR.
values selected for warming up.
5. How is the pressure drop in the upstream Correct, additional margin on the Kv-value is
isolation valves and the piping accounted for. considered due to manufacturer margin and
Is the 10% considered to cater for these specification requirements of the valve supplier
pressure drop values or is it the throttle margin
generally considered by valve supplier. So that
the flow in case the control valve opens fully
will be about 10% higher than the design flow.
6. How is the operating pressures for throttle Please consider the attached pressure loss calculation.
valve design arrived at. Kindly include the
same in this document

Page: 51 / 54
Design Report Steam
N-100141-S-H__-IB07-00011
NTPC DRG NO.
N-100141
0306-102-PVM-U-0951
BGR/HPE to clarify the reason for

7. No. Due to avaible system pressure and steam
considering warm up at 25 % BMCR. It extractions sootblowing is possible at 35%BMCR.
may be noted that in the soot blower
design report, it has been mentioned that
soot blowing can start at lower loads also.
Please furnish the basis of the starting at
25% BMCR.
With the current sizing, it indicates that

the line for soot blowers will be charged
only after 25% BMCR and the soot
blowers will be taken into service only
after 35% BMCR. Kindly clarify. Is this a
standard practice adopted by HPE for
their boilers.
8. 90 minutes for warming up the system Correct. The time amount is increased as per standard
appears to be on the higher side. Kindly practice.
clarify is this a standard practice adopted
by HPE and the give some reference
plants where this has been adopted
(especially high ash coal firing)
9. What is the mass of steel piping to be Calculation is attached.
heated considered in this calculation.
Kindly include a row
10. does this imply dryness factor of 100% Correct.
11. How has the heat loss been arrived at. Done.
Kindly include a supplementary
calculation
12. What parameters have been considered There is no loss in enthalpy. Enthalpy is constant, the
at orifice inlet. How has the loss in pressure and temperature decrease.
enthalpy in the orifice been considered
13. Kindly also include the case for use of Noted.
Aux PRDS steam for APH soot blowing
especially at low loads when oil firing is in
progress
14. Please also consider the case where oil Only one RAH soot blower will be in operation.
firing is being done when soot blowing
has to be done continuously, then more
than one RAH soot blowers would be in
operation continuously (one PAPH & one
SAPH) to avoid oil deposition and
chances of fire.
15. Now that air heater supplier has been Done.
firmed up. Kindly check the value with
BWE, Denmark
16. HPE Mass flow and pressure are adopted due to the
soot blower supplier data.

Page: 52 / 54
Design Report Steam
N-100141-S-H__-IB07-00011
NTPC DRG NO.
N-100141
0306-102-PVM-U-0951
Meja, NTPC comments dated: 16.06.2014

Written comments dated: 16.06.2014
17. Comments marked on the document Noted
Marked-up comments dated: 16.06.2014

18. Refer Introduction 4th Paragraph: Just a The pressure will rise, if the soot blower drainage
clarification- how the pressure is control valve is closed and the pressure reducing
supposed to rise? by heat from furnace in station, due to a malfunction, is fully opened.
case the isolating valves are left closed?
1. Can we identify the soot blower
19. 1. The provided steam temperature at soot blower
manufacturers recommendation as to the
inlet will be ensured by the hot standby mass flow.
superheat to be maintained at soot
blowers to avoid any moisture ingress The soot blower steam temperatures are available
(which leads to erosion/failure). Also the for the soot blower supplier. The steam
superheat at soot blower outlet need to be temperatures are based on the Reheater 1 and
a target value for system design at all Reheater 2 inlet parameters (Turbine data cold
loads (especially minimum unit loads). reheat line and turbine requirements for the hot
This need ton be discussed for soot reheat line). No enthalpy modification can be
blower farthest from the steam source as executed in this regard. Please take in
steam will tend to cool down as it travels consideration, that this topic should be discussed
in the system. with the soot blower supplier, as the dryness
fraction is in dependence of the blowing pressure.
2. Type of PRV need to be identified as 2. Design Criteria for the pressure reducing
these are high pressure drop valves and station are given in the document: Design Data
prone to failure which eventually leads to Sheet of Steam Soot blower Control Valves
loss of soot blower performance (and 0360-102-PVI-Y-0688.
water ingress).
Please take into consideration, that the design
report illustrates the calculated requirements for
the relevant components and valves. The finally
chosen type of valves is not part of this document
and can´t be bounded on that.
In case of a malfunction, wo redundant pressure
reducing stations are available. As per
specification an additional PRS 40% is available

Page: 53 / 54
Design Report Steam
N-100141-S-H__-IB07-00011
NTPC DRG NO.
N-100141
0306-102-PVM-U-0951
20. Refer chapter 3.2.3:- Regarding The safety valve is capable to carry out the
Sootblower safety valve design- Why is maximum mass flow of the pressure reducing
this margin taken? Will this not distort the station. Therefore undesired pressure increase in
valve selections? Is this soot blower the system will be avoided.
manufacturers recomendation?
The maximum mass flow of the pressure reducing
station contains an additional margin, which can
be compared with the working requirements of the
soot blower supplier and the provided design
mass flow of the pressure reducing station.
To fix the maximum flow downstream the PRS,
the max Kv-Value of the PRS is limited. (Please
compare Design Data Sheet of Steam Soot
blower Control Valves 0360-102-PVI-Y-0688)
21. Refer table- Warm up for Bundle In order to avoid temperature drop of the soot
Sootblowers Two hours system heating blower steam, the pre warming of the steel has to
time- does it mean that for starting the unit be done in advance
(which will require APH soot blowers in
Auxiliary steam can be used for pre warming the
the begining; unit need to be prepared 2
APH connection pipes, in advance.
hours in advance (heating the APH soot
blowing system?) Kindly clarify.
22. Refer Comment No. 2:- It is once again Noted.
requested to attach FDBR extract
23. Refer HPE reply to NTPC comment No.6:- The design is based on HPE practice.
Regarding Warming-up time is the same
time used for Eskom references as well
24. Refer HPE reply to NTPC comment This topic should be discussed with the APH
No.12:- Does it mean that continuous soot supplier. In this context, one soot blower can be
blowing of RAH is not required. It can be operated continuously. No additional soot blower
done one at a time. can be taken in operation, if one is already in use.
HPE/BGRB Based on the clarifications provided during the
25.
TCM (07.07.2014–11.07.2014), the document
(Design Report Steam Soot Blowers 0306-102-
PVM-U-0951) is approved in Cat-I in principle.
HPE Comments dated: 27.10.2014

26. HPE/BGR The previous revision of the Design Report Steam
Soot Blower was send up, by using a wrong
NTPC identification number.
Due to this fact same report will be provided to
NTPC with a new revision status and the correct
identification number.

Page: 54 / 54

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AC 22.10.

2014 Denis See compliance sheet Busekrus

CHENNAI – HYDERABAD – MUMBAI - NOIDA

Design Report Steam Soot Blowers

Ersteller / Prepared by Geprüft / Checked by: Datum /Date: Rev.:

3 Soot Blower Valves Boiler ........................................................ 11

4 Soot Blower Valves Air Pre-Heater .......................................... 38

4.1.2 Design Criteria ....................................................................................................................... 38

5 Compliance sheet ..................................................................... 51

Ersteller / Prepared by Geprüft / Checked by: Datum /Date: Rev.:

Figure 1: Basic overview of Boiler & Air Heater Soot Blowers................................................... 8

Ersteller / Prepared by Geprüft / Checked by: Datum /Date: Rev.:

Following documents should be taken as design criteria reference:

Unheated pressure parts: Doc. No.: 9571-102-PVM-Y-0028

Predicted performance data: Doc. No.: 9571-102-PVM-Y-0012

Boiler upper part longitudinal section: 9571-102-PVM-B-0149

Boiler lower part longitudinal section: 9571-102-PVM-B-0151

Ersteller / Prepared by Geprüft / Checked by: Datum /Date: Rev.:

P&I-Diagram Steam Soot Blower Tube Banks: 9571-102-PVM-F-0088

P&I-Diagram Steam Soot Blowers Furnace: 9571-102-PVM-F-0089

Process Description Soot Blowers: 9571-102-PVM-X-0192

Design Data Soot Blower System: 9571-102-PVM-Y-0016

Design Data Sheet of Steam Sootblower Control Valves: 9571-102-PVI-Y-0688

Design Data Sootblower Safety Valves: 9571-102-PVM-Y-0048

Design Data Sheet of Steam Sootblower Throttle Valve: 9571-102-PVM-Y-0184

Ersteller / Prepared by Geprüft / Checked by: Datum /Date: Rev.:

M Motorized Stop Valve

M Pressure Reducing Station

Pneumatic Control Valve

Eco Tube Banks

Superheater and Reheater Tube Banks

Furnace Walls To Flash Tank

4 Regenerative Airheaters (RAH)

Figure 1: Basic overview of Boiler & Air Heater Soot Blowers.

Ersteller / Prepared by Geprüft / Checked by: Datum /Date: Rev.:

2 Boiler Soot Blower

2.2 Design Criteria

Ersteller / Prepared by Geprüft / Checked by: Datum /Date: Rev.:

Ersteller / Prepared by Geprüft / Checked by: Datum /Date: Rev.:

3 Soot Blower Valves Boiler

3.1 Pressure Reducing Station

3.1.2 Design Criteria Pressure Reducing Station

Ersteller / Prepared by Geprüft / Checked by: Datum /Date: Rev.:

Following mass flows is taking place for the wall blowers:

Maximum 2 bundle and 2 wall blowers in operation simultaneously

2 * 2,43 + 1,2 + 2 * 0,55 + 0,4 = 7,56 kg/sec

Total mass flow for warm up: 3,2 + 0,8 = 4 kg/sec

Ersteller / Prepared by Geprüft / Checked by: Datum /Date: Rev.:

3.2 Soot blower Safety Valve

3.2.2 Design Criteria Safety Valve

Ersteller / Prepared by Geprüft / Checked by: Datum /Date: Rev.:

Maximum Flow rate kg/s

Figure 2: Overview of Kv - value of the pressure reducing station

Ersteller / Prepared by Geprüft / Checked by: Datum /Date: Rev.:

3.2.4 Sample calculation of the Kv-Value

Ersteller / Prepared by Geprüft / Checked by: Datum /Date: Rev.:

3.2.1 Pressure losses Design Conditions

3 From RH tapping point

4 Isolation valve (manual)

5 Isolation valve (motorised)