Tutorials Manual

More documents

Recommendations

Info

Chemkin 4.1.1 Chapter 3: Catalytic Processes of the honeycomb monolith. The metal surface area is 189 m 2 /g and the metal dispersion is 70%. Based on the inlet stream properties, mass flow rate, and the geometry of the honeycomb monolith, we find that the inlet velocity of the catalytic combustor should be 1200 cm/sec. Since we want to make the catalyst last longer to reduce operating costs, we need to keep the catalyst surface below its maximum operating temperature. Theoretically the maximum surface temperature in the catalytic combustor should not exceed the adiabatic flame temperature of the inlet gas mixture. In other words, we can determine the maximum equivalence ratio of the fuel-air mixture entering the catalytic combustor by comparing the adiabatic flame temperatures against the maximum catalyst operating temperature. The adiabatic flame temperature of a given equivalence ratio can be easily obtained by using CHEMKIN's Equilibrium Reactor Model. Of course, the minimum equivalence ratio of the inlet fuel-air mixture is the one below which no light-off is observed on the catalyst surface. Accordingly, we set the equivalence ratio to 0.185. With all the basic information defined, we are ready to build a simple reactor network model for our two-stage combustor system. We choose the Honeycomb Monolith Reactor Model to represent the first-stage catalytic combustor and a Plug Flow Reactor Model for the second-stage homogeneous combustor. Since all of the initial fuel is expected to be consumed by the catalytic combustor, we have to inject additional fuel to the second-stage homogeneous combustor. To achieve this, we need to add a gas mixer between the Honeycomb Monolith Reactor and the Plug Flow Reactor in our reactor network model. A fourth reactor, which can be either a PSR or a PFR, is added after the PFR (the homogeneous combustor) to simulate the post-flame flow in transition to the gas turbine and to allow the introduction of excess air to cool down the flue gas if needed. Figure 3-2 shows the “diagram” of our combustor system model that comprises four reactor clusters. We will run these clusters in sequence. Temperatures of both the additional fuel and the excess air are assumed to be the same as the inlet temperature of the catalytic combustor. The mass flow rate of excess air is the difference between the design flow rate of the gas turbine and the exit mass flow rate of the homogeneous combustor. The amount of fuel added to the homogeneous combustor should be able to raise the gas temperature high enough so that, after excess air dilution, the gas temperature can still meet the required TRIT. After a few iterations, we find the additional fuel mass flow rate is 1.5 g/sec. © 2007 Reaction Design 94 RD0411-C20-000-001
Chapter 3: Catalytic Processes <strong>Tutorials</strong> <strong>Manual</strong> Figure 3-2 Two-Stage Catalytic Combustor—Diagram View Now we can further set up our combustor system model by providing proper information on each input panel. The catalyst properties and the honeycomb monolith geometry are entered on two special sub-tabs (please see Figure 3-3 and Figure 3-4). To find these two special sub-tabs, go to the Honeycomb Monolith Reactor’s Catalytic Pre-combustor (C1_) panel and click on the Honeycomb Monolith tab. Figure 3-3 Catalytic Pre-combustor (C1_)—Honeycomb Monolith, Catalyst sub-tab RD0411-C20-000-001 95 © 2007 Reaction Design
Page 1 and 2:
August 3, 2007 1:53 am Release 4.1.
Page 3 and 4:
Chemkin 4.1.1 Contents Table of Con
Page 5 and 6:
Chemkin 4.1.1 Tables List of Tables
Page 7 and 8:
Tutorials Manual 4.1.1 Figures List
Page 9 and 10:
List of Figures Tutorials Manual 2-
Page 11 and 12:
List of Figures Tutorials Manual 4-
Page 13 and 14:
Chemkin 4.1.1 1 1 Introduction The
Page 15 and 16:
Chapter 1: Introduction Tutorials M
Page 17 and 18:
Chemkin 4.1.1 2 2 Combustion in Gas
Page 19 and 20:
Chapter 2: Combustion in Gas-phase
Page 21 and 22:
Page 23 and 24:
Page 25 and 26:
Page 27 and 28:
Page 29 and 30:
Page 31 and 32:
Page 33 and 34:
Page 35 and 36:
Page 37 and 38:
Page 39 and 40:
Page 41 and 42:
Page 43 and 44: Chapter 2: Combustion in Gas-phase
Page 91 and 92: Chemkin 4.1.1 3 3 Catalytic Process
Page 93: Chapter 3: Catalytic Processes Tuto
Page 97 and 98: Chapter 3: Catalytic Processes Tuto
Page 115 and 116: Chemkin 4.1.1 4 4 Materials Problem
Page 117 and 118: Chapter 4: Materials Problems Tutor
Page 145 and 146:
Chapter 4: Materials Problems Tutor
Page 147 and 148:
Page 149 and 150:
Page 151 and 152:
Page 153 and 154:
Page 155 and 156:
Page 157 and 158:
Page 159 and 160:
Page 161 and 162:
Chemkin 4.1.1 5 5 Chemical Mechanis
Page 163 and 164:
Chapter 5: Chemical Mechanism Analy
Page 165 and 166:
Page 167 and 168:
Page 169 and 170:
Page 171 and 172:
Page 173 and 174:
Page 175 and 176:
Page 177 and 178:
Tutorials Manual 4.1.1 Index Index
Page 179 and 180:
Index Tutorials Manual normalized s
show all

Tutorials Manual

Create successful ePaper yourself

Delete template?

Save as template?