| Popis: |
The authors sketch briefly the development of railroad air conditioning and outline the methods of refrigeration that are used for cooling passenger cars. They give the results of a study of passenger-car air conditioning conducted in 1936 by the Association of American Railroads, which included: (a) Determination of the efficiency of the air-conditioning systems in use, by means of laboratory tests; (b) determination of the mechanical efficiency of the drive mechanisms; (c) a survey of the performance of the equipment in service; and (d) determination of the comparative costs of air conditioning. Based upon these tests, the authors develop the horsepower demand upon a locomotive by the different air-conditioning systems. They give formulas by which the cost of air conditioning per 1000 car-miles for the various systems may be calculated. These formulas take into consideration the variables confronted in actual operating service, namely, the length of the cooling season, the speed of the train, the total miles traveled per year, the cost of coal, water, ice, etc., and the proportion of time the equipment is operating and not operating during the cooling season. Tables and curves are given showing the total cost of the different methods of air conditioning for a variety of operating conditions. |
