Heat and ThermodynamicsMcGraw-Hill, 1911 - 346 pages |
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Common terms and phrases
absorbed adiabatic expansion ammonia amount application of heat aspirating stroke assumed atmosphere ature body boiler Boyle's Law calorimeter capacity per unit Carnot cycle cent change in entropy compression compressor condensation constant pressure constant temperature constant volume cooling corresponding curve cylinder walls density determined dryness energy exhaust exhaust-valve follows fuel gases gram calories heat of vaporization heat taken hence high-pressure hydrogen ideal coefficient indicator diagram initial internal combustion engine interval isothermal isothermal process liquid loss mass of water means measured mercury motor numerically equal obtained operation Pava perature pipe piston pressure and volume pressure p₁ put into contact quantity of heat radiation ratio reciprocating engine refrigerating machine refrigerator represented reversible reversible adiabatic process reversible engine saturated scale speed substance superheated T₁ takes place temperature T1 thermal capacity thermal efficiency thermodynamic thermometer turbine unit mass v₁ valve velocity vessel zero
Popular passages
Page 7 - ... to the quantity of heat required to raise an equal mass of water through the same temperature interval, is called the specific heat of the substance.
Page 330 - ... the single-stage type, 12-in. and 29-in. by 24-in., fitted with Corliss valves on the air cylinder. The whole condensing plant is capable of maintaining a vacuum within 1.1 in. of the barometer when condensing 150,000 Ib. of steam per hr. when supplied with circulating water at 70 deg. fahr. " 17. The electric generator is of the three-phase induction type, star-wound for 11,000 volts, 25 cycles and a speed of 750 rpm The rotor is of the squirrel-cage type with bar winding connecting into common...
Page 76 - Substituting, in equation (15), we have finally (16) ie, the speed of propagation of a disturbance through an elastic medium is numerically equal to the square root of the ratio of elasticity to density.
Page 330 - ... 7500-kw. (maximum rating) unit, as by this means we would not only get an increase of 100 per cent in capacity, but at the same time give the engines a new lease of life by bringing them up to a thermal efficiency higher than that attained by any other type of steam plant. 15 The turbine installed is of the vertical three-stage impulse type having six fixed nozzles and six which can be operated by hand, so as to control the back pressure on the engine, or the division of load between engine and...
Page 330 - ELEVATION AND PART SECTION OF LOW-PRESSURE TURBINE UNIT breaker on the condenser, is the only form of governor used. The footstep bearing, carrying the weight of the turbine and generator rotors, is of the usual design supplied with oil under a pressure of 600 lb. per sq. in. with the usual double system of supply and accumulator to regulate the pressure and speed of the oil pumps. 16 The condenser contains approximately 25,000 sq. ft. of cooling surface arranged in the double two-pass system of...
Page 322 - ... reached and that hereafter the problem of design is to be merely one of altering dimensions to suit varying sizes and speeds. While this is true as far as the efficiency is concerned, other problems are continually arising, such as the design of generators for an overload capacity of 100 per cent. to meet the demand for apparatus capable of taking care of great overloads economically for short periods, corresponding to peak loads of a railroad or lighting plant. " Item 15. Engine Radiation Losses....
Page 328 - ... cost of a low-pressure turbine unit is slightly lower than that of a high-pressure unit, due to the omission of the high pressure stages and the hydraulic governing apparatus, but the cost of the condensing apparatus would be the same in both cases. The foundations and the steam piping in both cases would not differ greatly. The economic results, so far as the first cost is concerned, would then be approximately the same, if we consider the general case only; but in this particular instance the...
Page 331 - The method of starting is simplicity itself — the exciting curent is put on the engine generator before starting the engine, and then the engine is started, brought up to speed and synchronized in exactly the same way as before. While starting in this way, the induction generator acts as a motor until sufficient steam passes through the engine to carry the turbine above synchronism, when it immediately becomes a generator and picks up the load. Three of these 7500-kw. low-pressure turbine units...
Page 332 - The net results obtained by the installation of low-pressure turbine units may be summarized as follows: a An increase of 100 per cent in maximum capacity of plant. 6 An increase of 146 per cent in economic capacity of plant. c A saving of approximately 85 per cent of the condt used steam for return to the boilers.
Page 326 - ... built up of riveted steel plates of sufficient weight to act as a flywheel for the two engines connected to it. This arrangement gives a very compact two-bearing unit. The valve gear on the high-pressure cylinders is of the poppet type, and on the low-pressure of the Corliss double-ported type. " 4. The condensing apparatus consists of barometric condensers, arranged so as to be directly attached to the low-pressure exhaust nozzles, with the usual compound displacement circulating pump and simple...