tailieunhanh - Internal Combustion Engines Fundamentals Episode 2 part 12

Tham khảo tài liệu 'internal combustion engines fundamentals episode 2 part 12', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | 890 INTERNAL COMBUSTION ENGINE FUNDAMENTALS a What is the power in kilowatts which the turbocharger turbine Tr must produce What is the gas temperature at exit to the turbocharger turbine b What is the power turbine power output c The heat losses in the engine are 15 percent of the fuel s chemical energy rổLHv - Find the engine power output the total system power output and the total system brake fuel conversion efficiency friction effects in the engine and power turbine are internal to these devices and do not need to be explicitly evaluated . FIGURE P15-3 . The attached graph shows how the brake power and specific fuel consumption of a four-stroke cycle single-cylinder spark-ignition engine vary with the fuel air equivalence ratio at wide-open throttle. It also shows how the following efficiencies vary with equivalence ratio The volumetric efficiency tiv The mechanical efficiency rjm Eq. ENGINE OPERATING CHARACTERISTICS 891 The combustion efficiency fl Eq. The indicated fuel conversion efficiency JỊ I Eq. The indicated thermal conversion efficiency rj i Eq. a Derive a relation between the variables fiít Ị ric and fl j. b Derive an equation which relates the brake power pb to rj tỊc I and any other engine and fuel parameters required. c Explain briefly why the variations of JỊm ffc rif j ÍỊ I with equivalence ratio in the figure have the form shown . why the parameter is approximately constant or has a maximum minimum or decreases increases with increasing richness or leanness etc. . 153. The diagram shows the layout of a low heat loss turbocharged turbocompounded diesel engine. The engine and exhaust system is insulated with ceramics to reduce heat losses to a minimum. Air flows steadily at kg s and atmospheric conditions into the compressor c and exits at 445 K and 3 atm. The air is cooled to 350 K in the intercooler I. The specific heat of ah cp is 1 kJ kg-K. In the reciprocating diesel engine the fuel flow rate is kg s the