The purpose of the paper is to develop the theoretical bases and practical tools for internal combustion engines (ICE) technical monitoring and diagnostics issues, which meet the requirements of industry 4.0, allowing increasing the volume of diagnostic information, including the parameters of the operating processes, and don’t require any intervention in the engine design and operation.
The first chapter deals with the review of the perspectives of ICE application for transport vehicles, which proved vast usage of this type of engines at least until 2050, while for the marine ships ICE remains the only alternative until 2040. To increase the efficiency of the engine operation during its lifetime, the technical monitoring is applied and helps to control the engine conditions in the interval between scheduled maintenance. The application of the engine digital twins, based on advanced mathematical models, has significant potential in terms of extracting more information from the monitoring data and could also be applied for possible malfunctions diagnosis, as it is shown.
The second chapter shows the development of the ICE mathematical model, which is adopted for the technical monitoring and diagnostics tasks. The decomposition of the engine as the set of interacting open thermodynamic system (OTS) is presented. Different kinds of models are applied to every OTS: quasi-steady 0D single and double zone models for cylinders and manifolds; unsteady 1D model for intake and exhaust pipes; heuristic models for compressors and turbines. The different models coupling issues together with the development of efficient numerical methods for solving the sets of equations are also considered. In particular, the variable step computational mesh application helps to increase the calculations speed and to provide necessary detailing of calculations at specific regions. The problems of the centrifugal compressor unstable behavior assessment are also addressed.
The third chapter reveals the peculiarities of the ICE transient behavior as the part of the transport vehicle power plant and the methods of engine transient simulation for monitoring issues. The effect of thermal inertia is considered in details as it has a significant effect on the parameters of engine operation.
The fourth chapter shows the results of experimental study of the ICE operation at the laboratory conditions. The experimental data, which includes engine steady and transient operation trials, was used for mathematical model calibration and approval of calculation capabilities.
The fifth chapter is devoted to the development of the Blitz-PRO online ICE digital twins service and the methods of its application for the ICE monitoring and diagnostics tasks. The application of the developed methods for the automotive engines monitoring helps to identify the experimental data, collect statistics and make diagnostics related to possible engine malfunctions. As for the main marine engines diagnostics tasks, the Blitz-PRO service is implemented into the DEPAS diagnostic system and proved to be useful tool for the experimental data advanced analysis.
The sixth chapter deals with the influence of various factors on the transport vehicle ICE operation in terms of its operational efficiency rising.
The scientific novelty of the work is as following:
- the methods of ICE technical condition monitoring and diagnosing are proposed, which apply digital twins of the diagnosis object and help to increase the amount of diagnostic information without interruption into engine design;
- the developed methods allow to consider the ICE supercharging units’ operation, including compressor rotating stall and surge behavior;
- the significant influence of thermal inertia on the engine transient operation is proved, and the methods of its account are developed;
- the rational level of detailing of the engine operating cycle simulation model for the technical monitoring tasks is defined.
The practical value of the work is a release of the software service Blitz-PRO, available online via the internet, which is developed to monitor and diagnose the of the vehicles’ ICE technical condition, collect statistics of engine parameters change during operation of the transport vehicle.
Key words: digital twin, technical monitoring, technical state diagnostics, internal combustion engine, operating process synthesis, mathematical simulation, unsteady operation, online service.
