Date post: | 03-Jun-2018 |
Category: |
Documents |
Upload: | pvirgosharma |
View: | 231 times |
Download: | 0 times |
of 53
8/12/2019 3195 292334 Boiler Performance
1/53
ENERGY PERFORMANCE
ASSESSMENT
OF BOILERS
8/12/2019 3195 292334 Boiler Performance
2/53
Introduction
Performance of the boiler, like
efficiency and evaporation ratioreduces with time, due to
1. Poor combustion,
2. Heat transfer fouling
3. Poor operation and maintenance.
4. Deterioration of fuel quality andwater quality also leads to poorperformance of boiler.
8/12/2019 3195 292334 Boiler Performance
3/53
IntroductionEfficiency testing helps us to find out
how far the boiler efficiency driftsaway from the best efficiency.
Any obsered abnormal deiations couldt!erefore be inestigated to pinpointt!e problem area for necessarycorrectie action. Hence it is necessary
to find out t!e current leel ofefficiency for performance ealuation,w!ic! is a pre requisite for energy
conseration action in industry.
8/12/2019 3195 292334 Boiler Performance
4/53
Purpose of the Performnce Test
1.To find out the efficiency of the boiler2.To find out the Evaporation ratio
The purpose of the performance test is todetermine actual performance and efficiencyof the boiler and compare it with design values
or norms. It is an indicator for tracking daytoday and seasontoseason variations inboiler efficiency and energy efficiencyimprovements.
8/12/2019 3195 292334 Boiler Performance
5/53
Performnce Terms nd
!efinitions
8/12/2019 3195 292334 Boiler Performance
6/53
Reference Stndrds
British stndrds" BS#$%& '(#)
ASME Stndrd& PTC*$*' Po+erTest Code for Stem Genertin,
-nits
IS #)%.& Indin Stndrd for
Boi/er Efficienc0 Testin,
8/12/2019 3195 292334 Boiler Performance
7/53
8/12/2019 3195 292334 Boiler Performance
8/53
British stndrds" BS#$%& '(#)
contd11
The efficiency of a boiler is (uoted as the ) of
useful heat a*ailable" e'#ressed as a #ercenta!eof the total ener!y #otentially a*ailable by
burnin! the fuel. This is e2pressed on the 3sis
of ,ross c/orific 4/ue 5GC671
8/12/2019 3195 292334 Boiler Performance
9/53
British stndrds" BS#$%& '(#)
contd11
This deals with the com#lete heat balance and it
has two #arts:
. Prt Ideals with standard boilers" where the
indirect method is s#ecified
. Prt IIdeals with com#le' #lant where there are
many channels of heat flow. In this case" both the
direct and indirect methods are a##licable" in
whole or in #art.
8/12/2019 3195 292334 Boiler Performance
10/53
ASME Stndrd& PTC*$*'
Po+er Test Code for Stem
Genertin, -nits
This consists of
. Prt One: +irect method $also called as
In#ut ,out#ut method%
. Prt T+o: Indirect method $also called as-eat loss method%
8/12/2019 3195 292334 Boiler Performance
11/53
IS #)%.& Indin Stndrd for
Boi/er Efficienc0 Testin,
ost standards for com#utation of boiler efficiency"includin! IS #)%.and BS#$%are desi!ned for s#ot
measurement of boiler efficiency. In4ri3/0" // these
stndrds do not inc/ude 3/o+ do+n s /oss in the
efficienc0 determintion process1
Boiler efficiency can be tested by the followin! methods:
1% The !irect Method& /here the ener!y !ain of the
wor&in! fluid $water and steam% is com#ared with theener!y content of the boiler fuel.
0% The Indirect Method& /here the efficiency is the
difference between the losses and the ener!y in#ut.
8/12/2019 3195 292334 Boiler Performance
12/53
The !irect Method Testin,
8/12/2019 3195 292334 Boiler Performance
13/53
Merits of !irect Method
Merits
1 P/nt peop/e cn e4/ute 8uic9/0 the
efficienc0 of 3oi/ers
1 Re8uires fe+ prmeters for
computtion
1 Needs fe+ instruments for monitorin,
8/12/2019 3195 292334 Boiler Performance
14/53
!emerits of !irect Method
!emerits
1 !oes not ,i4e c/ues to the opertor s to +h0
efficienc0 of s0stem is /o+er
1 !oes not c/cu/te 4rious /osses
ccount3/e for 4rious efficienc0 /e4e/s
1 E4portion rtio nd efficienc0 m0mis/ed" if the stem is hi,h/0 +et due to
+ter crr0o4er
8/12/2019 3195 292334 Boiler Performance
15/53
The Indirect Method Testin,
8/12/2019 3195 292334 Boiler Performance
16/53
Losses in the Boi/er
The fo//o+in, /osses re pp/ic3/e to /i8uid",s nd so/id fired 3oi/er
L'1 Loss due to dr0 f/ue ,s 5sensi3/e het7
L:1 Loss due to h0dro,en in fue/ 5;:7
L.1 Loss due to moisture in fue/ 5;:O7
L$1 Loss due to moisture in ir 5;:O7
L%1 Loss due to cr3on mono2ide 5CO7
8/12/2019 3195 292334 Boiler Performance
17/53
Losses in the Boi/er Cont11
L
8/12/2019 3195 292334 Boiler Performance
18/53
Mesurements Re8uired for
Performnce Assessment
Testin,
7 F/ue ,s n/0sis
1. ercenta!e of 230or 30in flue !as
0. ercenta!e of 23 in flue !as
. Tem#erature of flue !as
8/12/2019 3195 292334 Boiler Performance
19/53
Mesurements Re8uired for
Performnce Assessment
Testin,
37 F/o+ meter mesurements for
1. uel
0. Steam
. eed water
4. 2ondensate water
5. 2ombustion air
8/12/2019 3195 292334 Boiler Performance
20/53
Mesurements Re8uired for
Performnce Assessment
Testin,
c7 Temperture mesurements for
1. lue !as 0. Steam . a&eu# water
4. 2ondensate return 5. 2ombustion air. uel 7. Boiler feed water
8/12/2019 3195 292334 Boiler Performance
21/53
Mesurements Re8uired for
Performnce Assessment
Testin,
d7 Pressure mesurements for
1. Steam
0. uel
. 2ombustion air" both #rimary and secondary
4. +raft
8/12/2019 3195 292334 Boiler Performance
22/53
Mesurements Re8uired for
Performnce Assessment
Testin,
e7 ter condition
1. Total dissol*ed solids $T+S%
0. #-
. Blow down rate and (uantity
8/12/2019 3195 292334 Boiler Performance
23/53
TYPICAL INSTRUMENTS
T C di i d
8/12/2019 3195 292334 Boiler Performance
24/53
Test Conditions nd
Precutions
A7 The efficienc0 test does not ccount for&.Standby losses. 6fficiency test is to be carried out" when the
boiler is o#eratin! under a steady load. Therefore" the combustion
efficiency test does not re*eal standby losses"which occur between
firin! inter*als.Blow down loss. The amount of ener!y wasted by blow down*aries o*er a wide ran!e.
.Soot blower steam. The amount of steam used by soot blowers is
*ariable that de#ends on the ty#e of fuel.
.Auxiliary equipment energy consumption. The combustionefficiency test does not account for the ener!y usa!e by au'iliary
e(ui#ments" such as burners" fans" and #um#s.
T t C diti d
8/12/2019 3195 292334 Boiler Performance
25/53
Test Conditions nd
Precutions
B7 Preprtions nd pre conditions for testin,
. Burn the specified fue/5s7 t the re8uired rte1
1 !o the tests +hi/e the 3oi/er is under sted0 /od1 A4oid testin,
durin, +rmin, up of 3oi/ers from co/d condition1 O3tin the chrts t3/es for the ddition/ dt1
1 !etermintion of ,ener/ method of opertion
1 Smp/in, nd n/0sis of fue/ nd sh1
1 Ensure the ccurc0 of fue/ nd sh n/0sis in the /3ortor01
1 Chec9 the t0pe of 3/o+ do+n nd method of mesurement
1 Ensure proper opertion of // instruments1
1 Chec9 for n0 ir infi/trtion in the com3ustion one.
T t C diti d
8/12/2019 3195 292334 Boiler Performance
26/53
Test Conditions nd
Precutions
C7 F/ue ,s smp/in, /oction
It is su,,ested tht the e2it duct of the 3oi/er 3e pro3ednd tr4ersed to find the /oction of the one of
m2imum temperture1 This is /i9e/0 to coincide +ith the
one of m2imum ,s f/o+ nd is therefore ,ood
smp/in, point for 3oth temperture nd ,s n/0sis1
T t C diti d
8/12/2019 3195 292334 Boiler Performance
27/53
Test Conditions nd
Precutions
!7 Options of f/ue ,s n/0sisCheck the Oxygen Test with the Carbon Dioxide Test
If continuous*redin, o20,en test e8uipment is inst//ed in
3oi/er p/nt" use o20,en redin,1
Occsion//0 use port3/e test e8uipment tht chec9s for 3otho20,en nd cr3on dio2ide1 If the cr3on dio2ide test does not
,i4e the sme resu/ts s the o20,en test" somethin, is +ron,1
One 5or 3oth7 of the tests cou/d 3e erroneous" perhps 3ecuse
of st/e chemic/s or driftin, instrument c/i3rtion1Another possi3i/it0 is tht outside ir is 3ein, pic9ed up /on,
+ith the f/ue ,s1 This occurs if the com3ustion ,s re
opertes under ne,ti4e pressure nd there re /e9s in the
3oi/er csin,1
T t C diti d
8/12/2019 3195 292334 Boiler Performance
28/53
Test Conditions nd
Precutions
Carbon onoxide Test
The carbon mono'ide content of flue !as is a !ood
indicator of incom#lete combustion with all ty#esof fuels" as lon! as they contain carbon. 2arbon
mono'ide in the flue !as is minimal with ordinary
amounts of e'cess air" but it rises abru#tly as soonas fuel combustion starts to be incom#lete.
T t C diti d
8/12/2019 3195 292334 Boiler Performance
29/53
Test Conditions nd
Precutions
E7 P/nnin, for the testin,
. The testin! is to be conducted for a duration of 4 to 8
hours in a normal #roduction day.
. d*anced #lannin! is essential for the resource
arran!ement of man#ower" fuel" water and instrument
chec& etc and the same to be communicated to the
3#eration and aintenance +e#artments.
. Sufficient (uantity of fuel stoc& and water stora!e
re(uired for the test duration should be arran!ed so that a
test is not disru#ted due to non,a*ailability of fuel and
water.
T t C diti d
8/12/2019 3195 292334 Boiler Performance
30/53
Test Conditions nd
Precutions
E7 P/nnin, for the testin, contdD
. ecessary sam#lin! #oint and instruments are to be
made a*ailable with wor&in! condition.
. ab nalysis should be carried out for fuel" flue !as
and water in coordination with lab #ersonnel.
. The steam table" #sychometric chart" calculator
com#uter etc are to be arran!ed for com#utation of
boiler efficiency.
C / / i P d d
8/12/2019 3195 292334 Boiler Performance
31/53
C/cu/tion Procedure nd
Formu/e
In order to calculate the boiler efficiency by indirect
method" all the losses that occur in the boiler must be
established. These losses are con*eniently related to theamount of fuel burnt.
In this way it is easy to com#are the #erformance of
*arious boilers with different ratin!s.
f T i f B il
8/12/2019 3195 292334 Boiler Performance
32/53
erformance Testin! of Boilers
Sam#le In#ut arameters , 1
'
:
.
$
%