Heat cycle and thermal efficiency of truck crane
2017-03-15 09:29:04
The thermal system undergoes a series of thermodynamic processes, and finally returns to the initial state, known as experiencing a thermodynamic cycle. If this cycle to join the heat in the outside, but also for positive work, is the heat cycle. A working cycle of the engine is a heat engine cycle, but the engine duty cycle does not meet the thermodynamics of the diesel engine economy is good, its operating fuel consumption is lower than the gasoline engine 20% - 30%. Modern high-performance automotive diesel engine thermal efficiency as high as 40% or more, vehicle gasoline engine thermal efficiency can reach about 33%. The performance of the engine include: dynamic performance indicators, economic performance indicators and operational performance indicators. Engine exhaust energy use of the basic form of two: one for the constant pressure booster system, the other for the pulse booster system.
The three basic theoretical cycles of the undercarriage are: constant volume heating cycle, constant pressure heating cycle and mixed heating cycle. The theoretical cycle of the engine is measured and evaluated by cyclic thermal efficiency and cyclic average pressure. The actual cycle of the four-stroke engine consists of four strokes of intake, compression, work and exhaust. The indicator of the engine is based on the working fluid in the cylinder on the work done on the piston, with the instructions, the average pressure and indicating the power to determine the power cycle. Evaluation of the engine cycle economy is the use of circulating thermal efficiency and fuel consumption rate. Engine performance of the three indicators: indicators, effective indicators and strengthen the indicators. Ventilation loss is composed of two parts: exhaust loss and intake loss.
The principle of selection of the supercharging system of the engine is: the low voltage boosting system is selected, and the constant voltage system is selected for the high pressure. At present, the engine fuel is mainly gasoline and diesel two kinds of petroleum products. The current national standard (GB484-89) provides the gasoline RQ90, RQ93, RQ97 and other varieties. Diesel fuel injection pump fuel more than two methods: the valve out of the valve correction and spring correction. There are three types of current valve correction: ① variable decompression volume, ② variable decompression effect, ③ oil valve throttling. The more appropriate heat dissipation law is the desire to burn the first slow after the emergency. There are two main types of gasoline engine mixture: one is the use of carburetor in the cylinder outside the formation of uniform combustible mixture, by controlling the throttle opening adjustment of the number of mixed gas. The other is the use of fuel injectors to the intake pipe, inlet or cylinder injection of gasoline to form a mixture. At present, most gasoline engines still use carburetors to form flammable mixtures.
The three basic theoretical cycles of the undercarriage are: constant volume heating cycle, constant pressure heating cycle and mixed heating cycle. The theoretical cycle of the engine is measured and evaluated by cyclic thermal efficiency and cyclic average pressure. The actual cycle of the four-stroke engine consists of four strokes of intake, compression, work and exhaust. The indicator of the engine is based on the working fluid in the cylinder on the work done on the piston, with the instructions, the average pressure and indicating the power to determine the power cycle. Evaluation of the engine cycle economy is the use of circulating thermal efficiency and fuel consumption rate. Engine performance of the three indicators: indicators, effective indicators and strengthen the indicators. Ventilation loss is composed of two parts: exhaust loss and intake loss.
The principle of selection of the supercharging system of the engine is: the low voltage boosting system is selected, and the constant voltage system is selected for the high pressure. At present, the engine fuel is mainly gasoline and diesel two kinds of petroleum products. The current national standard (GB484-89) provides the gasoline RQ90, RQ93, RQ97 and other varieties. Diesel fuel injection pump fuel more than two methods: the valve out of the valve correction and spring correction. There are three types of current valve correction: ① variable decompression volume, ② variable decompression effect, ③ oil valve throttling. The more appropriate heat dissipation law is the desire to burn the first slow after the emergency. There are two main types of gasoline engine mixture: one is the use of carburetor in the cylinder outside the formation of uniform combustible mixture, by controlling the throttle opening adjustment of the number of mixed gas. The other is the use of fuel injectors to the intake pipe, inlet or cylinder injection of gasoline to form a mixture. At present, most gasoline engines still use carburetors to form flammable mixtures.