1.2 1.3 (a) (b) (c) (d) (e) (f) (g) State the most desirable process for minimum work for a reciprocating compressor. The volumetric efficiency of a reciprocating compressor can be improved in two ways. Sketch a labelled indicator diagram (indicate the directions) and flow diagram/plan to show the effect of intercooling on the compression work and intercooling between a two-stage compressor. A four-stage compressor works between limits of 1 bar and 120 bar. The index of compression in each stage is 1.25, the temperature at the start of compression in each stage is 30 C, and the intermediate pressure are selected such that work is divided equally among the stages. If the clearance is negligible: Sketch the labelled indicator diagram with direction on process curve and for this 4-stage compressor in question, Calculate: the intermediate pressure in each stage, the temperatures at the end of each stage, the mass flow rate in kg/h if work input is a unit kW, the volume of free air delivered per kilowatt-hour at 1.013 bar and 20 C, isothermal work input, and isothermal efficiency.