Question

Air box orifice =15mm Atmospheric pressure, Pu = 101.3 kPa Inclined manometer slope = 1:5 Air box diameter = 300mm Item: Test No. 1: Test No. 2: Motor speed 1, rpm, N1 1 300 1 400 Compressor speed 1, 651 704 rpm, NZ 830 900 19.4°C 19.5°C Power inputs, watts Ambient temperature, T1 Stage 1 compressor outlet, T2 90.8°C 74.5°C 17°C 17.4°C Water inlet, Tw1 Water outlet, Tw2 18.1°C 18.4°C 160mm - 20mm = 140mm Air box manometer, 155mm - 35mm mmH2O, ЛР = 120mm First stage inlet, kg/cm², 101.3 kPa P1 101.3 kPa 3.08 Kg/cm2 3.08 Kg/cm2 First stage outlet, Kg/cm2, P2 3 Kg/cm2 3 Kg/cm2 Air Receiver, Kg/cm2, PA Water flow rate, 1/min 1.7 1.7

Just use results from Test No. 1 and other info provided.

Answer 1

The swept volume of the cylinder is calculated using the given bore and the stroke. Since there are two cylinders, it is multiplied by two. Density of air at inlet of compressor can be obtained. The volume flow rate can be calculated as the swept volume is known and the RPM of the compressor is also known. Once volume flow rate is known, the mass flow rate can be calculated. The given electrical power is the actual work or actual power supplied and it can be converted to horsepower. The isentropic and isothermal process are represented on the TS chart. The isentropic power and the isothermal power can be computed. The isentropic efficiency can also be computed as the ratio of isentropic power to the actual power (which is supplied by motor). Similarly, isothermal efficiency will be the ratio of isothermal power to the actual power. Finally, the volumetric efficiency will be the ratio of swept volumetric flow rate to the actual volumetric flow rate. The actual volumetric flow rate can be obtained as the actual power supplied is given (which is the power of motor).

Swept volume - dºll.2 * * * * x es'x 40 x 2 + y = 292011.04 m. Isentropic Deurity of Aix at Inlet 101.3x1000 2. P-627) 287 x (273+19.4) 3 P, = 1.207 Kg/m Ikuthehual گے (x-1) ly volume flow Rate P = Us (1/60) % = ( 29 2011.04) x/651 (6) E = T ( 22 ) P2 = 3.08 kg flan? - 3168319.753 mm, mmilis = 302.045 Kia P = 101.3 Kla T = 273 +19.4 = 292.4K = 3.168 ans/ Electrical Horse Paser 830 745 = 7:1149 HP 8.4/1.4 m = P Q = 3.825 x10 kg/h Ta = (292-4)* (3021645) T2 = 399.52K (Ixo the forc Temperature cut Outlet) Istutireforc Power = macetz-T) 3.025X10 X 1005x (399.52 - 292-4) Isothermal Power = am RT 1 / 2 / 2 = (3.825x103) × 287 x 292.48 l/ 1302.045 101-3 745 745 0.5527 HP -3 = 0.47 HP Actual Power = molt F) = (3-826-x+6)x vousx(363-8-2924) [==90-86-=-343-BK) 745 Volumetric Efficiency Actual Towen -0.368 HP. (Swept volume) (Actual volume) (C) = 3.168 cm / 830 = PQ) (-) = 49.574% I Sectropie Efficiency Isothermal Efficiency = (0.5527) (1-1149) (0.47) (1.1149) 830 = 0.42156 = 42.16% (1.207) x 1005x(363-8 - 292.4) = 9.583 cmsls 3.168 - Mooi = 337 Much 13.100) 9.583