Steam Turbine Engineering (Paperback)

This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1906 Excerpt: ...For instance, in the above case the speed during expansion in the cylinder behind the piston will be negligible, but during exhaust from the cylinder it may amount to 300 metres per second. In this case the energy in the steam when leaving would be 382 + (t)3.) JL = 382 +107 = 393 kilogram-calories. x 9'ol/4-7 The energy given up by one kilogram of steam during expansion in the cylinder is therefore in this case equal to 618--393 = 225 kilogram-calories. It must be carefully understood that this law does not tell us what has become of the 236 or 225 kilogram-calories that have been given up by the steam. It may have been converted either into mechanical energy or into heat. It is, however, the purpose of a steam engine or a steam turbine to convert as much as possible of the original energy available in the steam into mechanical energy. From this point of view we must ascertain the law according to which the energy available in the steam can be converted into mechanical energy. For this purpose let us picture to ourselves an experiment in which steam is transformed from one state in which it has a given amount of internal energy, into another state in which it has a less amount. Let the conditions be such as to prevent any of the energy being given up as heat. We thus have the conditions necessary for studying the process of converting internal energy into mechanical energy, as we have cut off all other ways in which the internal energy of the steam can be transformed. The experiment could be of the following nature: --In a closed cylinder, the sides of which are of non-conducting material, a kilogram of saturated steam has an absolute pressure of p kilograms per square centimetre and a volume of v cubic metres. Let us now permit the piston to move under the..