Performance Evaluation of Performance Evaluation of Underground Mine Diesel Underground Mine Diesel Engine Exhaust Insulation Engine Exhaust Insulation
ProductsProducts
John StekarJohn StekarBob MojaverianBob Mojaverian
Catalytic Exhaust Products Limited MDEC Catalytic Exhaust Products Limited MDEC PresentationPresentationOctober 2009October 2009
AbstractAbstractProduct DescriptionProduct DescriptionProcedureProcedureChartsChartsConclusionConclusion
AbstractAbstract
The use of diesel engine exhaust insulation products are widesprThe use of diesel engine exhaust insulation products are widespread and ead and increasing inincreasing in mobile underground mining equipment mobile underground mining equipment applications.applications. Diesel engine exhaust insulation products minimize Diesel engine exhaust insulation products minimize engine exhaust heat energy loss which can improve the oxidation engine exhaust heat energy loss which can improve the oxidation performance of diesel oxidation catalysts and diesel particulateperformance of diesel oxidation catalysts and diesel particulatefilters.filters. In addition the passive regeneration performance of diesel In addition the passive regeneration performance of diesel particulate filters can also be improved through the use of diesparticulate filters can also be improved through the use of diesel engine el engine exhaust insulation products.exhaust insulation products. Several types of diesel engine exhaust Several types of diesel engine exhaust insulation products are currently offered by a variety of insulation products are currently offered by a variety of manufacturers.manufacturers. Very little published information is available concerning Very little published information is available concerning the thermal properties and performance of diesel engine exhaust the thermal properties and performance of diesel engine exhaust insulation products.insulation products.
In this technical paper 4 different types of diesel engine exhauIn this technical paper 4 different types of diesel engine exhaust insulation st insulation products provided by the same vendor are installed onto a 33 kW products provided by the same vendor are installed onto a 33 kW diesel diesel generator set and are evaluated based on ISO 8497.generator set and are evaluated based on ISO 8497. Each diesel Each diesel engine exhaust insulation product was installed onto an identicaengine exhaust insulation product was installed onto an identical engine l engine exhaust pipe which was instrumented with 6 thermocouples attacheexhaust pipe which was instrumented with 6 thermocouples attached to d to an 8 channel Omega TCan 8 channel Omega TC--08 datalogger.08 datalogger. The thermal insulation The thermal insulation performance, heat transfer, insulation surface temperatures and performance, heat transfer, insulation surface temperatures and rock rock impact damage to the surface of insulation are tested and reportimpact damage to the surface of insulation are tested and reported.ed. In In addition the sound attenuation of each type of diesel engine exhaddition the sound attenuation of each type of diesel engine exhaust aust insulation was tested and evaluated.insulation was tested and evaluated.
Insulation type CEP STD:
Outer layerGray color silicone impregnated fiberglass outer coverTemperature limit of 500 ºF (260 ºC).
Middle layerFiberglass Temperature limit of 1200 ºF (649 ºC).
Inner layerSteel mesh (304)Temperature limit of 1200 ºF (649 ºC).
Product DescriptionProduct Description
Insulation type CEP II:
Outer layerRed color Silicone impregnated fiberglassTemperature limit of 600 ºF (316 ºC).
Middle layerCalciumCalcium--MagnesiumMagnesium--Silicate Silicate (CMS) wool(CMS) woolTemperature limit of 1800 ºF (982 ºC).Thin sheet of stainless steel 321tainless steel 321
Inner layerSteel mesh (304)Temperature limit of 1200 ºF (649 ºC).
Insulation type CEP III:Insulation type CEP III:Outer layerOuter layer304 stainless steel knitted wire 304 stainless steel knitted wire meshmeshStainless steel laminated Stainless steel laminated fiberglassfiberglassTemperature limit of 932 Temperature limit of 932 ººF (500 F (500 ººC).C).Middle layerMiddle layerCalciumCalcium--MagnesiumMagnesium--Silicate Silicate (CMS) wool (CMS) wool Temperature limit of 1800 Temperature limit of 1800 ººF (982 F (982 ººC).C).Thin sheet of stainless steel 321Thin sheet of stainless steel 321
Inner layerInner layer304 Stainless steel knitted mesh304 Stainless steel knitted meshTemperature limit of 1200 Temperature limit of 1200 ººF (649 F (649 ººC).C).
Insulation type CEP Hard Coated (HC):
Outer layerBlack color Composite fiber
Inner layerHigh alumina ceramic fiberTemperature limit of 2300 ºF (1260 ºC).
Exhaust Pipe Insulation Test LayoutExhaust Pipe Insulation Test Layout
ProcedureProcedureThe exhaust pipe of a diesel genset was wrapped with 4 The exhaust pipe of a diesel genset was wrapped with 4
different types of removable insulation blanket. different types of removable insulation blanket. Six sensors were installed on an exhaust pipe insulation as Six sensors were installed on an exhaust pipe insulation as
shown in the previous slides.shown in the previous slides.Two extra sensors (T7 &T8) were set to measure ambient Two extra sensors (T7 &T8) were set to measure ambient
temperature.temperature.Temperatures measured in following steps: with engine off, Temperatures measured in following steps: with engine off,
while engine running with zero load, load increased to 36%, while engine running with zero load, load increased to 36%, then 72% and back to 36%, zero load, and finally then 72% and back to 36%, zero load, and finally measurement continued for the last stage after engine measurement continued for the last stage after engine turned off. The temperature of exhaust gas inside the pipe turned off. The temperature of exhaust gas inside the pipe was measured at Inlet (T5) and outlet (T6) and subtracted was measured at Inlet (T5) and outlet (T6) and subtracted to find the heat loss. The temperature of insulation inner to find the heat loss. The temperature of insulation inner layer (T2 , hot side) and outer layer (T1, cold side) were layer (T2 , hot side) and outer layer (T1, cold side) were measured and subtracted to evaluate heat retention. measured and subtracted to evaluate heat retention.
Temperature sensors connected to OMEGA TC-08 Datalogger
Load Bank
Exhaust pipe with no insulation installed
Exhaust gas temperaturemeasurement at outlet (T6)
Exhaust Pipe with no insulation - Temperature v.s. Time
0
50
100
150
200
250
300
350
400
0
3.2
6.4
9.6
12.8 16
19.2
22.4
25.6
28.8 32
35.2
38.4
41.6
44.8 48
51.2
54.4
57.6
60.8 64
67.2
70.4
73.6
76.8 80
83.2
86.4
89.6
92.8 96
99.2
102
106
109
112
115
118
122
125
Time [Min]
T [d
eg C
]
T1 Insulation cold side-outlet
T2 Insulation hot side-outlet
T3 Insulation cold side-inlet
T4 Insulation hot side-inlet
T5 Inlet gas
T6 Outlet gas
T7 Ambient
T8 Ambient
36% load 36% load
72% load
0% load 0% load
Exhaust pipe installed with CEP II insulation
T1 sensors installed on surface of CEP II insulation near outlet
Surface temperaturemeasurement(T3)
Pictures showing sensor T3 installed on the surface of CEP II
Gas inlet temperaturemeasurement(T5)
Sensor T2 installed on the pipe surface (under CEP II insulationSensor T2 installed on the pipe surface (under CEP II insulation) ) near the outletnear the outlet
Sound level measurement, CEP II insulation, near the inletSound level measurement, CEP II insulation, near the inlet
Exhaust Pipe+CEPII Insulation - Temperature v.s. Time
0
50
100
150
200
250
300
350
400
03.
46.
810
.213
.6 1720
.423
.827
.230
.6 3437
.440
.844
.247
.6 5154
.457
.861
.264
.6 6871
.474
.878
.281
.6 8588
.491
.895
.298
.610
210
510
911
211
611
912
212
612
913
313
613
914
314
615
0
Time [Min]
T [d
eg C
]
T1 Insulation cold side-outlet
T2 Insulation hot side-outlet
T3 Insulation cold side-inlet
T4 Insulation hot side-inlet
T5 Inlet gas
T6 Outlet gas
T7 Ambient
T8 Ambient
Exhaust pipe + CEP II insulation, Temperature (deg C) vs. Time (sec)
36% load 36% load
72% load
0% load 0% load
Picture of exhaust pipe installed with CEP III insulation
Exhaust Pipe+CEPIII Insulation - Temperature v.s. Time
0
50
100
150
200
250
300
350
400
450
5 11 17 22 28 33 39 45 50 56 61 67 73 78 84 89 95 149
155
161
166
172
177
183
189
194
200
205
211
217
222
228
233
239
245
250
Time [Min]
T [d
eg C
]
T1 Insulation cold side-outlet
T2 Insulation hot side-outlet
T3 Insulation cold side-inlet
T4 Insulation hot side-inlet
T5 Inlet gas
T6 Outlet gas
T7 Ambient
T8 Ambient
72% load
36% load
36% load0% load
Picture of exhaust pipe installed with CEP STD insulation
Surface temperaturemeasurement(T3)
Pictures showing sensor T3 installed on the surface of CEP STD
Exhaust Pipe+CEP STD Insulation - Temperature v.s. Time
0
50
100
150
200
250
300
350
400
03.
46.
810
.213
.6 1720
.423
.827
.230
.6 3437
.440
.844
.247
.6 5154
.457
.861
.264
.6 6871
.474
.878
.281
.6 8588
.491
.895
.298
.610
210
510
911
211
611
912
212
612
913
313
613
914
314
615
0
Time [Min]
T [d
eg C
]
T1 Insulation cold side-outlet
T2 Insulation hot side-outlet
T3 Insulation cold side-inlet
T4 Insulation hot side-inlet
T5 Inlet gas
T6 Outlet gas
T7 Ambient
T8 Ambient
36% load36% load
72% load
0% load 0% load
Picture of exhaust pipe installed with CEP HC insulation
Exhaust Pipe+CEP HC Insulation - Temperature v.s. Time
0
50
100
150
200
250
300
350
400
0 3 7 10 14 17 20 24 27 31 34 37 41 44 48 51 54 58 61 65 68 71 75 78 82 85 88 92 95 99 102
105
109
112
116
119
122
126
129
133
136
139
143
146
150
153
Time [Min]
T [d
eg C
]
T1 Insulation cold side-outlet
T2 Insulation hot side-outlet
T3 Insulation cold side-inlet
T4 Insulation hot side-inlet
T5 Inlet gas
T6 Outlet gas
T7 Ambient
T8 Ambient
36% load 36% load
72% load
0% load 0% load
Surface temperature Insulation evaluationSurface temperature Insulation evaluationThe chart for surface temperature (measured with T1 The chart for surface temperature (measured with T1
sensor) vs. insulation type shown on the next two sensor) vs. insulation type shown on the next two slides. The chart shows that the skin (cold side) slides. The chart shows that the skin (cold side) temperature of CEP III has the lowest value (101 temperature of CEP III has the lowest value (101 ººC) compare to the other types of insulation (108 to C) compare to the other types of insulation (108 to 114 114 ººC). Therefore CEP III is the best insulation in C). Therefore CEP III is the best insulation in terms of surface temperature and safety. Note that terms of surface temperature and safety. Note that the Values lag behind load change due to the Values lag behind load change due to insulation resistance. It has a delay in reaching to insulation resistance. It has a delay in reaching to the maximum temperature during loading of the the maximum temperature during loading of the engine, and it has a delay in cooling off during engine, and it has a delay in cooling off during unloading of the engine, therefore as shown in the unloading of the engine, therefore as shown in the chart 36% load shows higher heat than 72%.chart 36% load shows higher heat than 72%.
Surface Temperature vs Insulation Type
32
23
31
22 25
38 39
47 47
109
56
70
54
75
189
108
102
87
102
114
108
101
111
216
88
76 77 80
144
38
53
59
50
73
260
0
50
100
150
200
250
CEP STD CEP II CEP III CEP HC Baseline (pipe only)
Engine Load
Tem
pera
ture
(deg
C)
Engine off No Load 36% Load 72% Load 36% Load No Load Engine off
Surface Temperature vs. Engine Load
25
109
189
216
144
73
32 38
56
108 114
88
3823
39
70
102 108
76
53
3148
58
94 95
7158
22
47
75
102111
80
50
260
0
50
100
150
200
250
Engine off No Load 36% Load 72% Load 36% Load No Load Engine offEngine Load
Tem
pera
ture
(deg
C)
No Insulation CEP STD CEP II CEP III CEP HC
Insulation Heat Retention EvaluationInsulation Heat Retention Evaluation
On the next two slides, the heat retention On the next two slides, the heat retention was calculated by subtracting T1 from T2.was calculated by subtracting T1 from T2.
It represents pipe surface temperature (hot It represents pipe surface temperature (hot side) minus insulation surface (cold side) side) minus insulation surface (cold side) temperature. As shown in next slide, CEP temperature. As shown in next slide, CEP III has the highest heat retention (245 III has the highest heat retention (245 ººC), C), than CEP II, CEP HC, and CEP STD.than CEP II, CEP HC, and CEP STD.
Heat Retention vs. Insulation Type
10
0
15
0 0
91 92
99
63
5
158
155
142
110
7
155
225
167
118
171 17
5
127
5
67
98
106
75
4
19
78
85
32
0
8
245
0
50
100
150
200
250
CEP STD CEP II CEP III CEP HC Baseline (pipe only)
Engine Load
Tem
pera
ture
(deg
C)
Engine off No Load 36% Load 72% Load 36% Load No Load Engine off
Heat Retention vs. Engine Load
0 5 7 5 4 010
91
158 155
118
67
190
92
155
225
171
9878
15
100
142
245
175
106
85
0
63
110
167
127
75
32
8
0
50
100
150
200
250
Engine off No Load 36% Load 72% Load 36% Load No Load Engine offEngine Load
Tem
pera
ture
(deg
C)
No Insulation CEP STD CEP II CEP III CEP HC
Heat loss inside exhaust pipeHeat loss inside exhaust pipe
On the next slide the heat lost was calculated by On the next slide the heat lost was calculated by subtracting exhaust gas temperature inside the subtracting exhaust gas temperature inside the pipe at inlet from the value at the outlet side, or pipe at inlet from the value at the outlet side, or T5 minus T6.T5 minus T6.
The lower the value, means lower heat loss, and The lower the value, means lower heat loss, and therefore a better insulation. CEP III, CEP II and therefore a better insulation. CEP III, CEP II and CEP STD are almost performed similar and CEP STD are almost performed similar and show lower values compare to CEP HC. show lower values compare to CEP HC. Therefore all three are acceptable in terms of Therefore all three are acceptable in terms of heat loss prevention.heat loss prevention.
Heat Loss vs. Insulation Type
16
6
0
26 26
17
27
32
39
35
32
41
46
54 54
62
20 20
22
25
35
5
9
8
11
16
18 18
19 19
15
55
0
10
20
30
40
50
60
70
CEP STD CEP II CEP III CEP HC Baseline (pipe only)
Engine Load
Tem
pera
ture
(deg
C)
Engine off No Load 36% Load 72% Load 36% Load No Load Engine off
70
Impact TestImpact Test
In this test 15.87 kg weight was dropped In this test 15.87 kg weight was dropped from a height of 4 feet on each insulation from a height of 4 feet on each insulation while strapped to the exhaust pipe.while strapped to the exhaust pipe.
CEP III, CEP II and CEP STD shows no CEP III, CEP II and CEP STD shows no visible damage to the surface of the visible damage to the surface of the insulation after the drop test. CEP HC was insulation after the drop test. CEP HC was dented (about 0.25dented (about 0.25”” deep).deep).
CEP HC with dent after the impact
CEP STD, II & III no visible permanent damage to the insulation after the impact
Sound Level MeasurementSound Level Measurement
Sound level vs. Engine Load
58
93 95 94 93
4955
93 94 96 93 92
5153
93 95 96 94 93
48
60
90 92 95 93 92
4750
91 93 94 93 91
48
96
0
20
40
60
80
100
Engine off No Load 36% Load 72% Load 36% Load No Load Engine offEngine Load
Soun
d Le
vel (
dBA
, SLO
W)
No Insulation CEP STD CEP II CEP III CEP HC
Sound level measured 26” away from the insulated exhaust pipe. It shows 1-3 dBA Improvement compare to pipe with no insulation. The sound measurement devicewas exposed to direct engine and other environmental noise.
Oil Absorption TestOil Absorption Test
Each insulation was submerged in oil for Each insulation was submerged in oil for an hour and weight before and after, the an hour and weight before and after, the result is shown as % gain over the original result is shown as % gain over the original weight:weight:CEP STD 75% (highest oil absorption)CEP STD 75% (highest oil absorption)CEP II 71%CEP II 71%CEP III 64%CEP III 64%CEP HC 33% (lowest oil absorption)CEP HC 33% (lowest oil absorption)
