A 4-cylinder 4-stroke internal combustion engine has cylinders of bore 6.1 cm, and stroke of 5.3...

 

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A 4-cylinder 4-stroke internal combustion engine has cylinders of bore 6.1 cm, and stroke of 5.3 cm. The clearance volume is 13% of the cylinder volume at BDC, and the crankshaft rotates at 3600 RPM. The processes within the cylinders may be modelled as closed system, cold air standard model, with pressure and temperature of 100 kPa and 300 K at the start of each compression. The maximum temperature in the cycle is 3,000 K for each cylinder. a) Create process (heat, work and internal energy) and state (temperature, pressure and specific volume) tables for the air at each cardinal state. [15 marks] b) Determine the net work per cycle, output power and thermal efficiency of this hypothetical engine. [5 marks] c) For process 2 to 3, determine the exergy change to heat ratio, and comment on the 2nd- Law efficiency of burning fuel to achieve this state change. [10 marks] A 4-cylinder 4-stroke internal combustion engine has cylinders of bore 6.1 cm, and stroke of 5.3 cm. The clearance volume is 13% of the cylinder volume at BDC, and the crankshaft rotates at 3600 RPM. The processes within the cylinders may be modelled as closed system, cold air standard model, with pressure and temperature of 100 kPa and 300 K at the start of each compression. The maximum temperature in the cycle is 3,000 K for each cylinder. a) Create process (heat, work and internal energy) and state (temperature, pressure and specific volume) tables for the air at each cardinal state. [15 marks] b) Determine the net work per cycle, output power and thermal efficiency of this hypothetical engine. [5 marks] c) For process 2 to 3, determine the exergy change to heat ratio, and comment on the 2nd- Law efficiency of burning fuel to achieve this state change. [10 marks]