Avtomobilʹnyj Transport (Harʹkov) (Jun 2020)
Concepts for building pneumatic hybrids
Abstract
The article considers the problem of improving the environmental and energy performance of a car through the use of compressed air energy. In this regard, the advantages of a pneumatic drive, in comparison with the electric drive and the drive from the internal combustion engine, in acceleration modes of a car in an urban transport cycle are noted. The relevance of research in this direction is con-firmed by examples of developments of foreign au-tomakers at the level of technical proposals, proto-types and serial production. The ways of improving the design of pneumatic hybrids with the aim of re-ducing the cost of pneumatic transmission and oper-ating costs are outlined. The goal of the research is to synthesize a hybrid power plant (HPP) of a pas-senger car with a main ICE and an auxiliary air mo-tor for operation in a city driving cycle. At the same time, the pneumatic drive is supposed to be used only in acceleration and recreational braking modes. To do this, it is necessary to determine the composition of the HPP, adhering to the criteria for minimizing fuel consumption and the cost of constructive refine-ment of the base transmission in a limited vehicle space. The research methodology includes a com-parative analysis of alternative HPP compositions for given vehicle characteristics and conditions of its operation. A qualitative assessment is given of the characteristics of pneumatic gas control systems of various structures from the standpoint of: energy completeness, autonomy of a gas station, a scheme for transferring energy to wheels, and the principle of constructing a pneumatic transmission. The design features of the pneumatic transmission are noted, due to the circuit of its components and the transport modes of the car. Based on the results of studies, the prerequisites for the use of a pneumatic drive on a car are formulated. Recommendations have been developed on the synthesis of a pneumatic regenerative acceleration-braking system in the HPP according to the given optimization criteria. Variant compositions of pneumatic HPP are proposed, oriented on a given driving cycle and drive scheme of the base vehicle. The features of the HPP composition and the design of a regenerative pneumatic transmission without external pressure recharging are noted. Recommendations are given on the selection of vehicle driving routes equipped with the acceleration-braking system in a regenerative mode. The scientific originality of the research is contained in the conceptual circuit solutions of alternative compositions of pneumatic gas control systems of the vehicle with energy recovery for the implementation of the functions of the acceleration-braking system. The practical value of the research is represented by recommendations that can be useful in the design of acceleration-braking systems for new and adaptation of existing power plants of cars operating in urban conditions.
Keywords
