| 释义 |
Rankine|ˈræŋkɪn|
[The name of William John Macquorn Rankine (1820–72), Scottish physicist and engineer.]
1. Used attrib. or in the possessive to designate concepts propounded by Rankine or arising out of his work, as Rankine cycle, a thermodynamic cycle which describes the operation of an ideal composite engine worked by steam or another condensable vapour, and is used as a standard of efficiency; Rankine efficiency, the efficiency of an engine relative to that of an ideal engine following the Rankine cycle; Rankine's (occas. Rankine) formula, any of a number of formulæ derived by Rankine in his work in various fields; spec. (see quot. 1940).
1868J. Bourne Treat. Steam-Engine (ed. 8) i. 86/1 (heading) Rankine's formula. 1891S. Anglin Design of Structures xi. 209 Apply Rankine's formula to determine the breaking weight of a wrought-iron hollow cylindrical column, its length being 10 feet, [etc.]. 1896R. H. Thurston in Jrnl. Franklin Inst. CXLII. 444 Comparing the efficiency of the best modern steam-engine employing saturated steam, about 0·20, with the Rankine cycle, which is that ideal cycle which constitutes the closest approximation to its method of steam distribution, the ideal case giving an absolute efficiency, 0·25, it is found to have, measured by this latter standard, a relative efficiency of 80 per cent. 1897J. A. Ewing Steam-Engine (ed. 2) iv. 120 Rankine's formula ought to be applicable when the amount of superheating is very great. 1907W. H. P. Creighton Steam Engine viii. 196 This engine is one which follows the Rankine cycle, where steam at a constant pressure is admitted into the cylinder with no clearance, and after the point of cut-off is expanded adiabatically to the back pressure. 1913J. Duncan Appl. Mech. for Engineers x. 237 At present, most designers rely on the Rankine formula coupled with a liberal factor of safety. 1930Engineering 6 June 739/3 The new Barton turbine is 8½ per cent. more efficient relative to the Rankine cycle than the older units. 1933T. H. Taft Elem. Engin. Thermodynamics ix. 130 (heading) Effect on the Rankine efficiency of changing conditions. 1940Chambers's Techn. Dict. 702/2 Rankine's formula, an empirical formula giving the collapsing load for a given column. 1954L. Pilborough Appl. Heat & Heat Engines xviii. 313 The Rankine efficiency may be used when determining the efficiency ratio of a steam plant. 1967Trans. Inst. Engineers & Shipbuilders in Scotland CX. 21 As turbine efficiency increases with superheat and decreases with pressure the Rankine efficiency gains are modified accordingly. 1976T. J. Reynolds et al. Struct. Steelwork (ed. 14) xi. 237 Using Rankine's formula, find the safe axial load for a 308 × 305 × 97 kg universal column 3·3 m high—to be regarded as having ends fixed—using the usual constraints for mild steel and adopting a factor of safety of 4. 1978Jrnl. R. Soc. Arts CXXVI. 608/2 We have not, however, been complacent about more advanced thermo⁓dynamic cycles. We have studied a number of possibilities of achieving higher thermal efficiency than the Rankine cycle used in most of our existing plant.
2. Used attrib. to designate a temperature scale in which the zero is identified with absolute zero and the degrees are equal in size to those on the Fahrenheit scale. Also degree Rankine (or Rankine degree), a degree of this scale; Rankine temperature, a temperature expressed in terms of this scale.
1941H. T. Wensel in Temperature (Amer. Inst. Physics) i. 10 The Rankine Scale is essentially the same scale [as the Kelvin]. Temperatures on the Rankine Scale are simply 9/5 of temperatures on the Kelvin Scale. 1941L. S. Marks Mech. Engineers' Handbk. (ed. 4) 295 Degrees Rankine (R) = degrees Fahrenheit + 459·69. 1962J. Thewlis Encycl. Dict. Physics VII. 207/1 On the Rankine scale, absolute zero is zero degree Rankine, the freezing point of water is 491·7° and the boiling point of water 671·7°. 1963Eastop & McConkey Appl. Thermodynamics i. 8 Note that 1 Kelvin degree is equivalent to 1·8 Rankine degree. 1974P. L. Moore et al. Drilling Practices Manual v. 131 Ts = Temperature at surface, degrees Rankine. |