Vankevych P. Development of the theory and principles of diagnostic machines by methods of contact thermometry

Українська версія

Thesis for the degree of Doctor of Science (DSc)

State registration number

0515U000253

Applicant for

Specialization

  • 05.11.13 - Прилади і методи контролю та визначення складу речовин

31-03-2015

Specialized Academic Board

Д 26.002.18

Publishing and Printing Institute of Igor Sikorsky Kyiv Polytechnic Institute

Essay

The dissertation is devoted to solving scientific and applied problems in the field of instrument, which is to create a theoretical propositions building complex with solid state devices, liquid and gaseous intermediate elements for thermal diagnostics of technical systems of moving objects. To solve the problem, the general mathematical model has been developed in which the obtained system of differential equations describing the propagation of heat in a moving material medium while taking into account the work being done by volumetric force in changing the values of thermal conductivity and the density of the medium, thus making it possible to develop a number of mathematical models for quantitative description of the processes of heat transfer for different measurement methods. The sources of errors included contact temperature measurement of moving objects. A number of dependencies for their evaluation was developed, and proposed methods to reduce them. The principles and algorithms of optimum criteria for certain devices used in contact temperature measurement of moving objects based on spectacular computational thermocouples models. A strategy for the creation, development and improvement of methods in constructing contact measurement of thermal parameters of moving objects technical systems was developed which includes the stages of development, creating a virtual model of a contact sensor, providing for the main inputs of heat transfer process, the accuracy of received information, and parametric optimization of the parameters of the measuring system. These methods of measuring the temperature of moving objects must have certain metrological characteristics; their definition is related to the establishment of a ratio between the actual temperature of the object of research and the temperature shown on measuring instruments. This ratio can be set according to the results of temperature field calculations in sensor elements of sensor, or by setting of experimental targets. Experimental verification of metrological characteristics allows us to draw a final conclusion about their actual numeric values. Theoretical and experimental studies done on development of wireless transmission systems and the current leading measurement approaches used in diagnosing the temperature of moving objects. A new theory based on methods of diagnosis using intermediate heat solid state, liquid and gas intermediate agents between the fixed primary surface thermocouples and moving research facilities. A new method for measuring the surface temperature of a moving object, the essence of which is to monitor the temperature of gas confined in a closed volume. The method proved the theoretical processes of heat transfer through a layer of gas, which is located between the surface of a moving object and weaves. Design schemes and technical parameters of a suitable device for measuring temperature were chosen according to the proposed method. Formulated criteria for choosing construction materials of elements of appliances, which are in contact with surfaces of experimental objects which include requirements for tribological, thermal and mechanical properties. A new approach to thermal diagnostics, based on the use of short-term and direct contact thermocouple with an experimental subject in which the thermometer performs motion trajectories which are identical trajectories of experimental objects. In the process of measuring contact with the research object undergoing rotational movement, developed a method of calculating using an established pattern of communication contact with thermocouple temperature plots of experimental objects surface temperature. Identified ratio that associates the speed of thermocouples and their time to achieve the maximum temperature, which makes it possible to increase the sensitivity and accuracy of thermocouple temperature measurement. Based on this quantitative research, formulated policies and established methodological foundations for the design of temperature control in thermal diagnostics of technical systems related to moving objects. Theoretical and experimental studies done on the development of algorithms and diagnostic systems for a variety of technical objects, which are key parameters of temperature. During the introduction of diagnosis, revealed some imperfections of nodes and machine components, resulting in new designs with improved operational and thermal characteristics. Established diagnostic system can determine structural imperfections of serial machines, and offer technical solutions to prevent the identified defects. The main results are suitable for practical application and implementation in projects requiring designed systems when measuring temperature of moving objects in engineered structures under given technological conditions and for the establishment of metrological support in various industries, research and learning processes. Key words: accuracy, mathematical model, thermal diagnostics, moving object, the research area, transmission system, the metrological characteristics of the device, parameter error, temperature, thermometer.

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