. Steam engines, a thorough and practical presentation of modern steam engine practice . etical engine. Fig. 70, is supposedto receive heat from the generator at constant temperature Ti untilcommunication is interrupted at B, The working substance expandsto C without losing or gaining any heat from external sources until the temperature of the refrig-erator is reached. The enginenow rejects heat at the constanttemperature T2 of the refrigera-tor and then compresses theworking substance without lossor gain in the quantity of heatuntil the temperature of theheat generator is reached. Theseare id
. Steam engines, a thorough and practical presentation of modern steam engine practice . etical engine. Fig. 70, is supposedto receive heat from the generator at constant temperature Ti untilcommunication is interrupted at B, The working substance expandsto C without losing or gaining any heat from external sources until the temperature of the refrig-erator is reached. The enginenow rejects heat at the constanttemperature T2 of the refrigera-tor and then compresses theworking substance without lossor gain in the quantity of heatuntil the temperature of theheat generator is reached. Theseare ideal conditions and, if ful-filled, the efficiency of the per-fect engine will depend only on the difference between the tempera-ture at which heat is received and rejected or, in other words, itdepends only upon the difference in temperature between the gen-erator and the refrigerator. If Ti equals the absolute temperature of the heat receivedand T2 equals the absolute temperature of the heat rejected, thenthe thermal efficiency E of the engine will be represented by theformula T,-T2. Fig. 70. Theoretical Indicator Diagram £ = - T, Or, in other words, the efficiency equals the absolute temperatureof the heat rejected, subtracted from the absolute temperature ofthe heat received, and the remainder divided by the absolute tem-perature of the heat received. ExAMTLE. Given an engine using steam at a 120 pounds absolute pressure,and exhausting at atmospheric pressure. What is the thermal efficiency? Solution. The absolute temperature corresponding to 120 poundspressure is + , or °, and the absolute temperature of theexhaust is 212+ , or °. Then STEAM ENGINES 107 .161, or per cent Losses in Practical Engine. In General. Iii actual enginesthis efficiency can not be realized, because the difference betweenthe heat received and the heat rejected is not all converted into use-ful work. Part of it is lost by radiation, conduction, co
Size: 1803px × 1386px
Photo credit: © Reading Room 2020 / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1920, booksubjectsteamen, bookyear1920
