Green-IT approach to design and optimization of thermoacoustic waste heat utilization plant based on soft computing

Abstract

Thermoacoustic devices (TAD) are the newest type of unconventional heat machines. Their work is based on the mutual transformation of heat and acoustic energies. This heat machines are characterized by high sensitivity to the working fluid properties (viscosity, density) as well as the environment effects (temperature, pressure, etc.). An effective work of TAD is possible only if the different nature values of the internal parameters (acoustic, hydrodynamic, thermal) are stabilized. The prospective area for thermoacoustic heat machines is their use in the waste energy recovery systems due to their ability to work with both high potential and low potential supplied heat. As the source of waste heat in such systems can be used the exhaust gases after the catalytic converters, or, taking into account latest results in low potential energy utilization with TAD, even the temperature of cooling water (about 90 °C). This paper is devoted to the synthesis of intelligent digital system for control of thermoacoustic plant with providing optimal working conditions for increasing its efficiency. Authors synthesize the fuzzy controllers of Mamdani and Sugeno types for the created control system. Designed fuzzy controllers are compared with a traditional PD controller in terms of their operation speed and accuracy. Special attention is paid to green-IT approach for design of embedded fuzzy systems by the optimization of fuzzy controllers based on the different type and parameters of linguistic terms for input and output signals as well as on minimization of fuzzy rules quantity in the preliminary synthesized fuzzy rule bases. The results of comparative analysis of initial and optimized fuzzy controllers are discussed in detail.