83 Three columns on the right side of table 4.1.5 give reference to the actual data log in appendix 4,
provide a guide on how to read the table and refer to related appendix for the data in respective rows.
4.1.6 Measurement with Urea Spray and 4 SCR bricks.
The test results with urea spray and 4 SCR bricks are summarized in the table 4.1.6. The same methodology used for Urea Spray with 1 SCR was utilised in this test. The main differences from the
1 SCR case is the NOx reading downstream of the SCR. Clearly in this test, excess ammonia from urea spray have reduced all of NOx but posses another problem in the system. The undesired NH
3
slippages have been detected and further analysis in the section 4.1.6 will discuss this in depth. Table 4.1.6 Summary of Result: Urea Spray with 4 SCR. all measurements in ppm
Results for urea spray 4 SCRs Temp upstream
592 K Temp downstream
582 K O2 upstream
9.30 O2 downstream
7.90
4 SCRs Spray pulse length ms --
24 26
28 30
32 34
36 Refn
Guide Apdx
Potential up 4SCR
Pot NH3
552 614
696 818
888 960
1042
calc A
3.6.2
Potential up 4SCR
Pot SUM
510 1062 1124 1206 1328 1398 1470 1552
nh3+nox B
MEXA up 4SCR
SUM
544 797
813 837
858 878
904 908
avg sum C
4.1.6B
MEXA, Spray off up 4SCR
NO
200 200
200 200
200 200
200 200
240708b D
4.1.6
MEXA, Spray off up 4SCR
NOx
510 510
510 510
510 510
510 510
240708b E
4.1.6
Calculated up 4SCR
NO2
310 310
310 310
310 310
310 310
calc F
MEXA Reading up 4SCR
NH3
38 318
346 381
405 434
466 240708b
G 4.1.6
Deduced ammonia up 4SCR
SUM-NOx
34 287
303 327
348 368
394 398
240708b C-E=H
4.1.6
MEXA dw 4SCR
SUM
539 78
128 181
242 304
367 424
avg sum I
4.1.6
MEXA dw 4SCR
NO
205 30
5 1
1 1
2
20708c J
4.1.6
Measured dw 4SCR
NH3
79 136
167 225
310 375
230708b K
4.1.6
NH3 + NO2 dw 4SCR
SUM-NO
334 48
123 180
241 303
365 424
calc I-J=L
Total consumed across 4 SCrs
Pot SUM- SUM
-29 984
996 1025 1086 1094 1103 1128
calc B-I=M
Note: Plotted against potential ammonia supplied
4 SCR spray
Pot NH3 up
552 614
696 818
888 960
1042 A
up - down, 4SCR Pot SUM-SUM 4 SCR
-29 984
996 1025 1086 1094 1103 1128
M
4SCR spray NOx or NH3consumed
-15 492
498 512.5 543
547 551.5 564
M2=N
4SCR spray NO consumed
-5 170
195 199
199 199
198 200
D-J=O
4SCR spray NO2 consumed
-9.5 322
303 313.5 344
348 353.5 364
N-O =P
concentration table pot NH3 up
552 614
696 818
888 960
1042 A
Deduced ammonia ups 4SCR
SUM-NOx
34 287
303 327
348 368
394 398
H NH3
14.5 60
116 183.5 275
341 408.5 478
A-N NOx
525 18
12 -2.5
-33 -37
-41.5 -54
E-N NO
205 30
5 1
1 1
2 D-O
NO2 320
-12 7
-3.5 -34
-38 -43.5
-54 F-P
Downstream
84 At the bottom of table 4.1.6 some of the NOx and NO
2
reading were showing negative values due to experimental error in this study using the methodology described earlier in the range of around +-
55 ppm. The NO
2
measurements were not measured directly but derived using the methodology described in section 4.1. It is believed that the negative values reflect the magnitude of the errors
resulting from these assumptions, but do not affect the general conclusions discussed later.
4.2 Ammonia gas studies: General Overview
