Question

Consider a four-cylinder, four stroke, compression ignition engine with a compression ratio of 22 and a cutoff ratio of 3. (a) Name the thermodynamic cycle you would use to analyze this engine, (b) draw the P-v and Tis diagrams for this cycle, (c) determine the heat input to the engine (in kJ/kg) if the temperature rise of the heat addition step is 1500°C, and (d) determine the engine speed in revolutions/minute (RPM) for a net power output of 50 kW if the net cycle work is 2.0 kJ/cycle. Properties of air: Cp = 1.005 kJ/kg:K, Cy= 0.718 kJ/kg:K, R = 0.287 kJ/kg:K, and k=1.4

Answer 1

SOLUTION? - This is a comprension dignition Engine & Diesel eyele ore Pual ence Cutoff Ratio : 3 compression Ratio=22 Now, this compression Ratio is too high for cycle. compiersion Ratios found sound in Diesel cycle. (2) The thermodynamico cycle to be used for analysis of Dual Whereas such are the engine would be the CONSTANT PRESSURE CYCLE or DIESEL CYCLE teat Addikon) V = 22 Р For dusel (1+2) Asenhopic compresion ate (cut off fourt) (2+3) = 4 sobaric heat addison + V3 (V=O + Heat Rezeumon = 3 (P-V + diegram V = Cutoff Ratio - V+ lesser slope (3-4) Isenbropic expansion (4-1) + $5 echowic heat Rejechon T (P-C) & more scope 2 4. Citeat addehors) (VTC) Heat Ryechon) diagram st

at constant Pressure Heat Input (leat addehon) process, for a constant presure proces heat addition (Qin) Pin = CpXAT (p = 05 kulky k Pin = 1.005x 1500 = 1:005 ATE + 1500G 1507.5 kJ laglendur 4 @ Wet Power Susput = 50 kw cycle No. of cylinders = 4 (50 kw) (3443) Net Work = 2 kJ / cycle I grinder 4-stroke Engine a revolutions For 4. Bloke engine, there is one poure stoke Thus, rcycle a revolutions cques (17 power shokes For N revolutions N (opm) + No Cops) N power shokes, 120 kes/ secondo For I Power stroke akJ work N Power stroke at N KJ work 120 60 Seond, - 50 N 60 [lower owput (16/2)) 3000 RPM N = 50x60 = Anson