Etude de la combustion de gaz de synthèse issus d'un processus de ...

More documents

Recommendations

Info

Chapter 2 product syngas to match those optimal for the desired end-use, although, at added complexity and cost. Specific applications are discussed in more detail below. 2.2.1 Power production Electricity generation is carried out by ICE, Stirling engines or turbines. Fuel cells have been proposed, but considerable development work is needed before these can be seriously considered. Data are available for gas turbines and engines operating on fossil fuels, but few robust data have been found on biomass-derived fuel gas machines, owing to the unknown costs of modification and maintenance and machine life. tel-00623090, version 1 - 13 Sep 2011 Essentially all biomass power plants today operate on a steam-Rankine cycle. Biomass-steam turbine systems are less efficient than modern electricity coal-fired systems in large part due to more modest steam conditions. The modest steam conditions in biomass plants arise primarily because of the strong scale-dependence of the unit capital cost of steam turbine systems-the main reason coal and nuclear steamelectric plants are built at a large scale. Biomass plants are usually of modest scale (less than 100 MW), because of the dispersed nature of biomass supplies, which must be gathered from the countryside and transported to the power plant. If bio-electric plants were as large as coal or nuclear power stations (500-1000 MW), the cost of delivering the fuel to the plant would often be prohibitive. To help minimize the dependence of unit cost on scale, vendors use lower grade steels in the boiler tubes of small-scale steam-electric plants and make other modifications which reduce capital cost, but also require more modest steam temperatures and pressures, thereby leading to reduced efficiency. The best biomass steam-electric plants have efficiencies of 20- 25% (Bridgwater, 1995). In order to make higher cost biomass resources economically interesting for power generation, it is necessary to have technologies which offer higher efficiency and lower unit capital cost at modest scale. One technological initiative aimed at improving the economics and efficiency of utility-scale steam cycle systems would use whole trees as fuel rather than more costly forms of biomass (e.g. woodchips). Gasification with turbines Gas turbines are noted for their efficiency; low emissions; low specific capital cost; short lead times by virtue of modular construction; high reliability and simple operation (Brander and Chase, 1992). Gas turbine integration with biomass gasification is not 31
Bibliographic revision established but there are many demonstration projects active with capacities 0.2-27 MW e . There are several issues that must be resolved in the integration of gas turbines with biomass gasification, including: - The reliable and environmentally sound operation of gas turbines with low heating value gases; - The selection of gasification operating pressure and the consequent integration of the air flow to the gasifier and fuel gas flow to the gas turbine combustor with the rest of the system; - Fuel gas cleaning and cooling; - The selection of the gas turbine cycle, although generally combined cycles are preferred. tel-00623090, version 1 - 13 Sep 2011 Gasification with engines The operation of diesel and spark-ignition engines using a variety of low heating value gases is an established practice (Nolting and Leuchs, 1995; Vielhaber, 1996; Tschalamoff, 1997). Both dual fuel diesel and spark ignition engines for operation using low heating value gases may be regarded as fully developed, although integration of a biomass gasifier and engine is not fully established. The main issue that must be resolved is the effective treatment of the fuel gas to cool and clean it to the specifications demanded by the engine. The fuel gas must be cool at injection to the engine and therefore wet scrubbing is the preferred gas treatment method (Bridgwater et al., 2002). In this approach the gases are cooled to under 150ºC and then passed though a wet gas scrubber. This removes particulates, alkali metals, tars and soluble nitrogen compounds such as ammonia. Fuel cells Fuel cells are static equipments that convert the chemical energy in the fuel directly into electrical energy. The operation principle of a fuel cell is similar to a battery. It is composed of a porous anode and a cathode, each coated on one side by a layer of platinum catalyst, and separated by an electrolyte. The anode is powered by the fuel, while the cathode is powered by the oxidant. There are various different types of fuel cells: - AFC - Alkaline Fuel Cell 32
Page 1 and 2: THÈSE Pour l’obtention du Grade
Page 3 and 4: Acknowledgements Acknowledgements T
Page 5 and 6: Résumé __________________________
Page 7 and 8: Nomenclature Nomenclature Roman tel
Page 9 and 10: Nomenclature Subscripts tel-0062309
Page 11 and 12: Contents tel-00623090, version 1 -
Page 13 and 14: Contents 6.4. SYNGAS FUELLED-ENGINE
Page 15 and 16: Introduction CHAPTER 1 INTRODUCTION
Page 17 and 18: Introduction proves to have higher
Page 19 and 20: Introduction Chapter 3 - Experiment
Page 21 and 22: Bibliographic revision CHAPTER 2 BI
Page 23 and 24: Bibliographic revision point today
Page 25 and 26: Bibliographic revision - Boudouard
Page 27 and 28: Bibliographic revision Table 2.1 -
Page 29 and 30: Bibliographic revision Biomass Dryi
Page 31 and 32: Bibliographic revision Circulating
Page 33: Bibliographic revision or eliminate
Page 37 and 38: Bibliographic revision Hydrogen Hyd
Page 39 and 40: Bibliographic revision of low moist
Page 41 and 42: Bibliographic revision scrubbing an
Page 43 and 44: Bibliographic revision suggests tha
Page 45 and 46: Bibliographic revision 1 d( δ A) 1
Page 47 and 48: Bibliographic revision Since n is
Page 49 and 50: Bibliographic revision 2 ( rsr ) 2
Page 51 and 52: Bibliographic revision This evoluti
Page 53 and 54: Bibliographic revision The burning
Page 55 and 56: Bibliographic revision δVG = − a
Page 57 and 58: Bibliographic revision 2 1 − −
Page 59 and 60: Bibliographic revision where the su
Page 61 and 62: Bibliographic revision the stretche
Page 63 and 64: Bibliographic revision burning velo
Page 65 and 66: Experimental set ups and diagnostic
Page 85 and 86:
Experimental set ups and diagnostic
Page 87 and 88:
Experimental set ups and diagnostic
Page 89 and 90:
Chapter 4 CHAPTER 4 EXPERIMENTAL AN
Page 91 and 92:
Chapter 4 4.1 Laminar burning veloc
Page 93 and 94:
Chapter 4 4.1.1.1 Flame morphology
Page 95 and 96:
Chapter 4 P i = 1.0 bar, Ti = 293 K
Page 97 and 98:
Chapter 4 Figure 4.5 shows schliere
Page 99 and 100:
Chapter 4 P i = 2.0 bar, T i = 293
Page 101 and 102:
Chapter 4 Sn (m/s) 3.0 2.5 2.0 1.5
Page 103 and 104:
Chapter 4 5 ms 10 ms 15 ms 20 ms 25
Page 105 and 106:
Chapter 4 behaviour of the curves r
Page 107 and 108:
Chapter 4 1.50 Sn (m/s) 1.25 1.00 0
Page 109 and 110:
Chapter 4 0.5 0.4 φ =1.0 Su (m/s)
Page 111 and 112:
Chapter 4 variation of the normaliz
Page 113 and 114:
Chapter 4 4.1.1.6 Comparison with o
Page 115 and 116:
Chapter 4 The values of laminar bur
Page 117 and 118:
Chapter 4 Pressure (bar) 7 6 5 4 3
Page 119 and 120:
Chapter 4 0.5 0.4 φ=1.2 Su (m/s) 0
Page 121 and 122:
Chapter 4 0.3 φ=0.8 Su (m/s) 0.2 0
Page 123 and 124:
Chapter 4 a minimum pressure to exp
Page 125 and 126:
Chapter 4 Notice the similar behavi
Page 127 and 128:
Chapter 4 A very good agreement bet
Page 129 and 130:
Chapter 4 ( ) Q = h T − T (4.21)
Page 131 and 132:
Chapter 4 tel-00623090, version 1 -
Page 133 and 134:
Chapter 4 are tested and discussed.
Page 135 and 136:
Chapter 4 7 500 Pressure (bar) 6 5
Page 137 and 138:
Chapter 4 Pressure (bar) 7 6 5 4 3
Page 139 and 140:
Chapter 4 4.2.3.4 Quenching distanc
Page 141 and 142:
Chapter 4 10000 Quenching distance
Page 143 and 144:
Chapter 5 CHAPTER 5 EXPERIMENTAL ST
Page 145 and 146:
Chapter 5 30 10 25 8 Pressure (bar)
Page 147 and 148:
Chapter 5 30 Piston position (mm) 2
Page 149 and 150:
Chapter 5 5.1.1.4 In-cylinder press
Page 151 and 152:
Chapter 5 estimation of various par
Page 153 and 154:
Chapter 5 TDC 1.25 ms 2.5 ms 3.75 m
Page 155 and 156:
Chapter 5 Piston position (mm) 500
Page 157 and 158:
Page 159 and 160:
Chapter 5 From figure 5.15 is possi
Page 161 and 162:
Chapter 5 From figure 5.16 is obser
Page 163 and 164:
Chapter 5 80 Pressure (bar) 70 60 5
Page 165 and 166:
Chapter 5 80 10 Pmax (bar) 70 60 50
Page 167 and 168:
Chapter 5 -5.0 ms -3.75 ms -2.5 ms
Page 169 and 170:
Chapter 5 observation emphasis the
Page 171 and 172:
Chapter 6 CHAPTER 6 NUMERICAL SIMUL
Page 173 and 174:
Chapter 6 centered at the spark plu
Page 175 and 176:
Chapter 6 H 2 O, (3) N 2 , (4) O 2
Page 177 and 178:
Chapter 6 For all the above express
Page 179 and 180:
Chapter 6 motions within the cylind
Page 181 and 182:
Page 183 and 184:
Chapter 6 Heat transfer Wei et al.,
Page 185 and 186:
Chapter 6 The calibration coefficie
Page 187 and 188:
Chapter 6 6.3.2.2 In-cylinder volum
Page 189 and 190:
Chapter 6 40 Experimental 30 Numeri
Page 191 and 192:
Chapter 6 80 70 60 Numerical Experi
Page 193 and 194:
Chapter 6 downdraft syngas than for
Page 195 and 196:
Chapter 6 80 23º BTDC 60 29.5º BT
Page 197 and 198:
Chapter 6 with experimental results
Page 199 and 200:
Conclusions CHAPTER 7 CONCLUSIONS 7
Page 201 and 202:
Conclusions radius and time for syn
Page 203 and 204:
Conclusions conditions, therefore s
Page 205 and 206:
Conclusions tel-00623090, version 1
Page 207 and 208:
References References tel-00623090,
Page 209 and 210:
References tel-00623090, version 1
Page 211 and 212:
Page 213 and 214:
Page 215 and 216:
Page 217 and 218:
Page 219 and 220:
Page 221 and 222:
Appendix A - Overdetermined linear
Page 223 and 224:
Appendix A - Overdetermined linear
Page 225 and 226:
Appendix B- Syngas-air mixtures pro
Page 227 and 228:
Appendix C -Rivère model Heat flux
Page 229 and 230:
Appendix C -Rivère model The work
Page 231 and 232:
tel-00623090, version 1 - 13 Sep 20
show all

Etude de la combustion de gaz de synthèse issus d'un processus de ...

Create successful ePaper yourself

Delete template?

Save as template?