THE STEAM-ENGINE AND OTHEE HEAT-ENGINES BY J. A. EWING, M.A., B.Sc, F.E.S., M.INST.C.E., PROFESSOR OF MECHANISM AND APPLIED MECHANICS IN THE UNIVERSITY OF CAMBRIDGE. CAMBRIDGE: AT THE UNIVERSITY PRESS. 1894 [All Bights reserved.]
CONTENTS. I. THE EARLY HISTORY OF THE STEAM-ENGINE. AKT. 1. Heat-Engines in general 1 2. Hero of Alexandria 2 3. Delia Porta and De Caus 3 4. Branca's Steam Turbine 4 5. Marquis of Worcester 4 6. Savery 5 7. Gunpowder Engines 7 8. Papin 7 9. Newcomen's "Atmospheric" Engine 9 10. James Watt 11 11. Watt's pumping-engine of 1769 13 12. Watt's narrative of his invention 15 13. Development of Watt's Engine: the rotative type... 19 14. Further improvements by Watt 19 15. Non-condensing Steam-Engines 21 16. Use of comparatively high-pressure steam 23 17. Compound Engines. Hornblower and Woolf.... 23 18. The Cornish Pumping Engine 24 19. Revival of the Compound Engine 26 20. Application to locomotives 27 21. Application to steamboats 28 22. Development of the Theory of Heat-Engines.... 30 II. ELEMENTARY THEORY OF HEAT-ENGINES. 23. Laws of Thermodynamics. The First Law.... 33 24. The Second Law of Thermodynamics 35 25. The Working Substance in a Heat-Engine 35
viii CONTENTS. AKT. 26. Graphic Representation of Work done in the changes of volume of a fluid 36 27. Cycle of operations of the working substance.... 37 28. Engine using a perfect gas as working substance... 38 29. Laws of the permanent gases. Boyle's law.... 39 30. Charles's law 39 31. Absolute temperature 40 32. Connection between Pressure, Volume, and Temperature in a gas. 41 33. The specific heat of a gas 41 34. The Internal energy of a gas 42 35. Relation between the two Specific Heats 43 36. Values of the constants for Air 44 37. Work done by an expanding fluid 44 38. Adiabatic Expansion 46 39. Change of temperature in the adiabatic expansion of a gas. 47 40. Isothermal Expansion 48 41. Carnot's Cycle of operations 50 42. Efficiency in Carnot's Cycle 52 43. Carnot's cycle reversed 52 44. Reversible engine 54 45. Carnot's Principle 54 46. Reversibility the criterion of perfection in a heat-engine.. 55 47. Efficiency of a perfect heat-engine 56 48. Summary of the argument 56 49. Conditions of maximum efficiency 57 50. Conditions of reversibility 58 51. Perfect Engine using Regenerator 59 52. Stirling's Regenerative Air-Engine 60 III. PROPERTIES OF STEAM AND ELEMENTARY THEORY OF THE STEAM-ENGINE. 53. Formation of steam under constant pressure.... 62 54. Saturated and superheated steam 63 55. Relation of pressure and temperature in saturated steam.. 63 56. Relation of pressure and volume in saturated steam... 64 57. Supply of heat in the formation of steam under constant pressure 66 58. Latent Heat of Steam 67 59. Total heat of steam 68 60. Internal energy of steam 69 61. Formation of steam otherwise than under constant pressure. 69 62. Wet steam 70 63. Superheated steam 70 64. Isothermal Lines for Steam 71
CONTENTS. IX 65. Adiabatio Lines for Steam 72 66. Formula connecting pressure with volume in the adiabatic expansion of steam 74 67. Carnot's cycle with steam for working substance... 75 68. Efficiency of a perfect steam-engine. Limits of temperature. 77 69. Efficiency of an engine using steam non-expansively.. 78 70. Engine with separate organs 79 71. How nearly may the process in a steam-engine be reversible? 81 IV. FUETHER POINTS IN THE THEORY OF HEAT-ENGINES. 72. Rankine's statement of the Second Law 85 73. Absolute Temperature: Lord Kelvin's scale.... 86 74. Calculation of the Density of Saturated Steam... 87 75. Extension of the above result to other changes of physical state. 90 76. Drying of steam by throttling or wire-drawing.... 91 77. Engine receiving heat at various temperatures.... 92 78. Application to the case of a steam-engine working without compression, but with complete adiabatic expansion... 93 79. Extension to the case of steam not initially dry... 97 80. Derivation of the adiabatic equation from this result.. 97 81. Entropy 98 82. Entropy of Steam : Derivation of the Adiabatic Equation. 100 83. Entropy-Temperature Diagrams 100 84. Entropy-Temperature Diagram for Steam : application to ideal steam-engine working without compression but with complete expansion 102 85. Application of the entropy-temperature diagram to the case of superheated steam 106 86. Values of the Entropy of Water and Steam.... 107 87. Entropy-temperature diagram for Steam used non-expansively 111 88. Incomplete expansion 112 89. Entropy-temperature diagrams in engines using a Regenerator 114 90. Joule's Air-Engine 115 91. Reversal of the cycle in heat-engines : Refrigerating Machines or Heat-Pumps 1]8 92. Coefficient of Performance of Refrigerating Machines.. 121 93. Reversed Joule Engine : the Bell-Coleman refrigerating machine 122 94. The Reversed Heat-Engine as a Warming Machine... 124 95. Heat-Engines employing more than one working substance : Steam and Ether Engines 126 96. Transmission of Power by Compressed Air.... 127
X CONTENTS. - V. ACTUAL BEHAVIOUE OP STEAM IN THE CYLINDER. AET. 97. Comparison of actual and ideal indicator diagrams... 131 98. Wire-drawing during Admission and Exhaust.... 132 99. Clearance 134 100. Compression 134 101. Cushion Steam and Cylinder Feed 136 102. Influence of the Cylinder Walls. Condensation and Re-evaporation in the Cylinder........136 103. Ee-evaporation continued during the exhaust.... 138 104. Wetness of the working steam 139 105. Graphic Representation, on the Indicator Diagram, of the water present during expansion 140 106. Use of the Entropy-Temperature diagram in exhibiting the behaviour of steam during expansion and the exchanges of heat between it and the cylinder walls..... 142 107. Thermodynamic Loss due to Initial Condensation... 144 108. Action of a Steam-jacket 144 109. Influence of Speed, Size, and Ratio of Expansion... 146 110. Results of Experiments with various ratios of Expansion. 148 111. Advantage of high speed 150 112. Experiments on the value of the Steam-jacket.... 151 113. Superheating.......... 152 114. Advantage of Compound Expansion 154 115. Summary of Sources of Loss 155 116. Methods of stating the performance of Steam-Engines.. 156 117. Efficiency of boiler and furnace. "Duty".... 157 118. Results of Trials : Non-Condensing Engines.... 159 119. Results of Trials : Condensing Engines 161 120. Mechanical Efficiency of the Engine 167 121. Curve of Expansion to be assumed in estimating the probable indicated horse-power of steam-engines..... 168 VI. THE TESTING OF STEAM-ENGINES. 122. The Indicator 169 123. Conditions of accurate working 172 124. Directions for taking Indicator Diagrams..... 175 125. Calculation of the Indicated Horse-Power 176 126. Examples of Indicator Diagrams 177 127. Thermodynamic Tests. Measurement of the Supply of Steam by means of the Feed 179
CONTENTS. xi ЛЕТ. РАНЕ 128. Measurement of the Supply of Steam by means of the Condenaed Water 181 129. Measurement of Jacket steam. 182 130. Comparison of Feed-water with Discharged Water...182 131. Estimation of Heat supplied. Measurement of Dryness of the Steam by the "Barrel" Calorimeter 183 132. Barrus Calorimeter. 184 133. Peabody Throttling Calorimeter 184 134. Measurement of Heat rejected by an Engine.... 185 135. Example of an Engine Trial 187 136. Wetness of the steam during expansion 189 137. Transfer of Heat between the Steam and the Metal. Hirn's Analysis 190 138. Tests of mechanical efficiency. Measurement of Brake Horsepower 192 139. Trials of an engine under various amounts of load... 193 VII. COMPOUND EXPANSION. 140. Woolf Engines 197 141. Receiver engine..........198 142. Drop in the Receiver. Compound diagrams.... 198 143. Adjustment of the division of work between the cylinders, and of the drop. Graphic method 201 144. Algebraic Method 203 145. Ratio of Cylinder Volumes 204 146. Advantage of Compound Expansion in the economical use of High-Pressure Steam 206 147. Mechanical advantage of Compound Expansion. Uniformity of Effort in a Compound Engine 206 148. Examples of Indicator Diagrams from Compound Engines. 208 149. Combination of the Indicator Diagrams in Compound Expansion 209 VIII. VALVES AND VALVE-GEAKS. 150. The Slide-Valve 215 151. Lap, Lead, and Angular Advance 216 152. Graphic method of examining the distribution of steam given by a slide-valve 219
XU CONTENTS. ART. 153. Inequality of the distribution on the two sides of the piston. 222 154. Zeuner's Valve Diagram 225 155. Oval Diagram 228 156. Harmonic Diagram 229 157. Reversing Gear. The Link-motion 232 158. Graphic Solution of the Link-motion 235 159. Equivalent eccentric 236 160. Eadial Gears 237 161. Separate expansion-valves 240 162. Meyer's Expansion-valve 241 163. Forms of slide-valves. Double-ported valve. Trick valve. 246 164. Belief Frames 247 165. Piston Valves 249 166. Rocking slide-valve 249 167. Double-beat valve. The Cornish cataract 250 IX. GOVERNING. 168. Methods of regulating the work done in a Steam-engine.. 252 169. Automatic regulation by centrifugal speed governors. Watt's Conical Pendulum Governor 253 170. Loaded Governors 253 171. Controlling Force 255 172. Condition of Equilibrium 255 173. Condition of Stability 256 174. Equilibrium of the Conical Pendulum Governor. Height of the Governor 256 175. Equilibrium of Loaded Governor 257 176. Sensibility in a Governor. Isochronism 259 177. Isochronism in the Gravity Governor. Parabolic Governor. 260 178. Approximate Isochronism in Pendulum Governors... 261 179. Governors with spring control. Adjustment of sensitiveness. 263 180. Determination of the Controlling Force 263 181. Influence of Friction. Power of the Governor.... 264 182. Curves of Controlling Force 266 183. Hunting 268 184. Governor with horizontal axis 269 185. Throttle-valve and automatic expansion-gear.... 270 186. Corliss and other Trip-gear 270 187. Disengagement governors 274 188. Eelay governors 275 189. Differential or dynamometric governors 276 190. Pump governors 278 191. Governing marine engines 279
CONTENTS. ХШ X. AKT. THE WORK ON THE CRANK-SHAFT. 192. Fluctuations of Speed during any single revolution : function of the Fly-wheel 280 193. Diagram of crank-effort 280 194. Effect of Friction 282 195. Effect of the inertia of the reciprocating pieces... 283 196. Inertia of the Connecting-rod 285 197. Treatment of Inertia and Friction together.... 287 198. Forms of Crank-Effort Diagrams 289 199. Fluctuation of Speed in relation to the Energy of the Flywheel 290 200. Reversal of thrust at the joints. Prevention of reversal of the thrust in single-acting engines 292 201. Balancing 294 PÄQE XL THE PRODUCTION OP STEAM. BOILERS. 202. Heating Surface, in Boiler and Feed-water Heater... 298 203. Draught 299 204. Sources of loss of Heat 301 205. Chimney Draught 302 206. Boilers for Stationary Engines. Cornish and Lancashire Types 303 207. Boiler Mountings 307 208. Multitubular Boilers 307 209. Vertical Boilers 308 210. Watertube Boilers 309 211. Locomotive Boilers 312 212. Marine Boilers... 315 213. Feeding boilers. The Injector 318 214. Feed-water heaters 320 215. Use of Zinc to prevent corrosion in boilers.... 320 216. Methods of forcing draught 321 217. Mechanical Stoking 322 218. Liquid Fuel 322
XIV CONTENTS. ABT. XII. FORMS OF THE STEAM-ENGINE. 219. Terms used in classification 324 220. Beam-Engines 325 221. Direct-acting Horizontal and Vertical Engines.... 326 222. Single-acting high speed Engines 329 223. Pumping Engines 334 224. The pulsometer 338 225. Davey's safety motor 339 226. Rotary Engines 340 227. Steam Turbines 342 228. Marine Engines 346 229. Relation of power to weight in Marine Engines... 349 230. Locomotives 350 231. Compound Locomotives 352 232. Tramway and Road Locomotives 354 XIII. AIB, GAS AND OIL-ENGINES. 233. Air and Gas-engines with external or internal combustion. 357 234. Air-engine using Carnot's cycle 358 235. External Combustion Air-engine with Regenerator: Stirling, Ericsson 358 236. Modern Air-engines of the Stirling type 361 237. Internal Combustion Air-engines 365 238. Early Gas-engines 367 239. The four-stroke cycle of Beau de Rochas and Otto... 368 240. The Otto Engine 369 241. Other Gas-engines 371 242. Action in the cylinder of the Otto Engine.... 373 243. After-burning 374 244. Performance of Gas-engines 377 245. Ideal performance of an internal combustion engine.. 380 246. Use of cheap gas 381 247. Oil-engines 383 APPENDIX : ' TABLE OP PROPERTIES OP SATURATED STEAM.. 387 INDEX 391