МОДЕЛЬ ПЬЕЗОЭЛЕКТРИЧЕСКОГО ПРЕОБРАЗОВАТЕЛЯ КЛАПАНА ПОДАЧИ ГАЗА В СУДОВОЙ ДИЗЕЛЬ-ГЕНЕРАТОР

Abstract

The increase of safety requirements and ensuring of the operability of marine dual-fuel diesel engines which are used on gas carriers and utilize evaporating gas from cargo tanks requires the use of devices based on new physical principles. Currently, an electromagnetic transducer – a solenoid, during the operation of which an incomplete opening / closing is observed, leading to frequent failures and methane slip, is used to control the gas admission valve. The aim of the study is to create a model of a piezoelectric actuator based on a stacked column of piezoelectric washers for gas supply valve to a marine diesel generator. Typical block of a model of piezoelectric washer with longitudinal polarization in the SimInTech electronic modeling environment based on PIC255 ferro-rigid ceramics, which allows to obtain maximum displacement, has been developed. The environment of electronic modeling allows in a short time to build a model of a large number of elements of the same type in the structure and, sometimes, with the same type of parameters, which give a gain compared to MathLab Simulink. Compiled piezo-washer models based on PIC255, SP-4, and Pb(ZrxTi1-x)O3-19 piezoceramics are listed in the SimInTech Electronic Modeling Component Palette library in the Actuator group of elements. As a result of modeling a piezoelectric transducer in the form of a stacked column, it has been found that blocks of three and sixty washers satisfy the requirements for the speed of the gas admission valve in marine dual-fuel medium-speed diesel generator. However, to increase the displacement, more than 200 elements are necessary, which leads to an increase in overall dimensions several times greater than the dimensions of the solenoid. An increase in the displacement with the minimum dimensions of the pillars is possible using differential structures, reinforcing elements in the form of rockers and levers. To reduce fluctuations, it is possible to use dynamic property correction methods – sequential correction and correction using flexible and rigid feedbacks, the use of controlled current sources, digital PID controllers and Fuzzy logic.