An account of the experiments made in Mulhouse, Germany, by a committee of the industrial society of that city, on a Corliss steam engine, to determine its economic performance with and without steam-jacketing

Isherwood
1881 Journal of the Franklin Institute  
RESULTS OF THE EXPERIMENTS. In all the experiments except H, I, Jand h, tile cut-off was fixed, so that the measure of expansion with which the ste'ml was used did not vary during each experiment. In experiments H, I, J and 1(, the cut-off was variable by the action of the governor, but the uuitbrmity of the load and the steadiness of the steam pressure restricted the point of cutting off withiu very narrow limits. The economy of the perfi)rmance in the diflbrent experiments may be compared for
more » ... the total horse-power and for the net horse-power developed by the engine, the units of heat consumed per hour pc1" horse-power being taken as the measure of the economy. The total horse-power represents the entire dynamic effect of the stealn, including overcoming the external load and the internal reslstance of the back pressure against the piston and all the friction resistances. The net horse-power represents that portion of the entire dynamic effect of the steam which is expended in overcoming the external load and the fl'iction of that load ; it is exclusive of the dynamic effect expended in overcoming the internal resistance of the back pressure against the piston, and of the friction of the unloaded engine. The net horset)ower is the only portion of the dynamic effbct of the steam which is commercially valuable, and its greater or less cost is the only economic problem in this relation to the user of steam power. Of the economy d~te to the d![ferent meas~tres of expansio~ with which the steam was ttsed. In the case of experiments A, .B and C, where there was no steam present in tile cylinder jackets or piston, the steam was expanded 12"3978 times in experiment A, and 7"9033 times in experiments B and C. Now as experiment Cwas a repetition of
doi:10.1016/0016-0032(81)90007-7 fatcat:j57mxhfapncc5gwqtoxay5fgyy