To improve the energy utilization efficiency of internal combustion (IC) engine, exergy analysis was conducted on a passenger car gasoline engine. According to the thermodynamic theory of IC engine, in-cylinder exer...To improve the energy utilization efficiency of internal combustion (IC) engine, exergy analysis was conducted on a passenger car gasoline engine. According to the thermodynamic theory of IC engine, in-cylinder exergy balance model was built. The working processes of gasoline engine were simulated by using the GT-power. In this way, the required parameters were calculated and then gasoline engine exergy balance was obtained by programming on computer. On this basis, the influences of various parameters on exergy balance were analyzed. Results show that, the proportions of various forms of exergy in gasoline engine from high to low are irreversible loss, effective work, exhaust gas exergy and heat transfer exergy. Effective exergy proportion fluctuates with cylinder volumetric efficiency at full load, while it always increases with break mean effective pressure (BMEP) at part load. Exhaust gas exergy proportion is more sensitive to speed, and it increases with speed increasing except at the highest speed. The lower proportion of heat transfer exergy appears at high speed and high load. Irreversible loss is mainly influenced by load. At part load, higher BMEP results in lower proportion of irreversible loss; at full load, the proportion of irreversible loss changes little except at the highest speed.展开更多
Based on the principle of thermal balance and material balance of lime furnace, the reaction and heat transfer process mathematical-physical model and the on-line monitoring model of the decomposition rate of limeston...Based on the principle of thermal balance and material balance of lime furnace, the reaction and heat transfer process mathematical-physical model and the on-line monitoring model of the decomposition rate of limestone were set up. With this model, numerical simulation is used to analyze the effects of operational parameters on the process of lime calcining and to optimize it. By using visual basic program to communicate and program, the centralized management and automatic control of the lime furnace are realized. The software is put into practical production, which makes the lime furnace operate steadily and efficiently, and causes the increase in output and decrease in energy consumption.展开更多
This paper presented a dynamical mathematical model for reheating furnace based on energy balance, which consists of three submodels. With the inputting parameters, adopting the finite difference technique, not only t...This paper presented a dynamical mathematical model for reheating furnace based on energy balance, which consists of three submodels. With the inputting parameters, adopting the finite difference technique, not only the combustion gas temperature but also the temperature distribution of slabs in the furnace can be predicated. The dynamical mathematical model is the base for the further control and it also can be treated as a simulator of a reheating furnace, optimal and advanced controlling strategies can be applied based on the dynamical model.展开更多
基金Foundation item: Project(2011CB707201) supported by the National Basic Research Program of China Project(10JJ5058) supported by the Natural Science Foundation of Hunan Province, China
文摘To improve the energy utilization efficiency of internal combustion (IC) engine, exergy analysis was conducted on a passenger car gasoline engine. According to the thermodynamic theory of IC engine, in-cylinder exergy balance model was built. The working processes of gasoline engine were simulated by using the GT-power. In this way, the required parameters were calculated and then gasoline engine exergy balance was obtained by programming on computer. On this basis, the influences of various parameters on exergy balance were analyzed. Results show that, the proportions of various forms of exergy in gasoline engine from high to low are irreversible loss, effective work, exhaust gas exergy and heat transfer exergy. Effective exergy proportion fluctuates with cylinder volumetric efficiency at full load, while it always increases with break mean effective pressure (BMEP) at part load. Exhaust gas exergy proportion is more sensitive to speed, and it increases with speed increasing except at the highest speed. The lower proportion of heat transfer exergy appears at high speed and high load. Irreversible loss is mainly influenced by load. At part load, higher BMEP results in lower proportion of irreversible loss; at full load, the proportion of irreversible loss changes little except at the highest speed.
文摘Based on the principle of thermal balance and material balance of lime furnace, the reaction and heat transfer process mathematical-physical model and the on-line monitoring model of the decomposition rate of limestone were set up. With this model, numerical simulation is used to analyze the effects of operational parameters on the process of lime calcining and to optimize it. By using visual basic program to communicate and program, the centralized management and automatic control of the lime furnace are realized. The software is put into practical production, which makes the lime furnace operate steadily and efficiently, and causes the increase in output and decrease in energy consumption.
文摘This paper presented a dynamical mathematical model for reheating furnace based on energy balance, which consists of three submodels. With the inputting parameters, adopting the finite difference technique, not only the combustion gas temperature but also the temperature distribution of slabs in the furnace can be predicated. The dynamical mathematical model is the base for the further control and it also can be treated as a simulator of a reheating furnace, optimal and advanced controlling strategies can be applied based on the dynamical model.