Entropy estimation method using heat in piston engines with non-equilibrium of inside-cylinder processes
2019
Zainetdinov, R., Saint-Petersburg State Agrarian Univ. (Russian Federation) | Belinskaia, I., Leningrad State Univ. named after Alexander Pushkin, St. Petersburg (Russian Federation) | Smelik, V., Saint-Petersburg State Agrarian Univ. (Russian Federation) | Novikov, M., Saint-Petersburg State Agrarian Univ. (Russian Federation)
Resource-saving technologies are now actively used in the field of piston design. The modernization of internal combustion engines should be based on evaluation of the efficiency. The development of new methods for assessing the thermodynamic efficiency of heat use in piston engines is an essential part of improving the efficiency of motor vehicles. At present, when assessing the efficiency of thermodynamic processes in internal combustion engines of the indicator efficiency, the essence of the process of converting the thermal form of energy into mechanical work is not considered. In this regard, there is a need to study the working processes of piston engines to develop a more advanced method. The article proves the prospects of using the entropy approach and variational principles of non-equilibrium thermodynamics. This method is based on the first and second laws of thermodynamics, and allows taking into account not only the quantity, but also the quality of energy. The differential equation of thermal balance of the engine taking into account heat dissipation in the engine is offered. This equation assumes establishment of functional dependence of production of entropy in systems on parameters of the irreversible thermodynamic processes proceeding in it, and also search of optimum of the received objective function. The proposed method of entropy analysis of non-equilibrium thermodynamic processes in piston engine systems allows to evaluate the degree of efficiency of each system and to investigate the maximum capabilities of the piston engine. As a result of using the proposed method, heat losses in the engine systems are reduced.
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