Vol 26, No 2 (2018)

Existing problems of controlling the technological process of burning ceramsite of a certain grade in strength (or density) in a rotary kiln are considered, due to a limited number of control actions and incompleteness of information on the temperature field in the «manual» kiln control. It is proposed to use a multidimensional automatic control system for ceramsite burning consisting of three interconnected channels: control of the volumetric capacity of the burner, the loading of the raw material, and the speed of rotation of the kiln. Each of these channels controls the temperature of the ceramsite in the corresponding section of the kiln and thus forms the necessary burning curve. The developed system allows not only to stabilize the strength (or density) of the ceramsite manufacturing, but also ensures a shortening of the technological transition time of the kiln from the manufacture of ceramsite of one mark to another.

In this paper the integral transformation of a random process is analyzed with a sufficiently General formulation of the problem. Similar problems were studied by the author earlier in relation to random functions in the electric power industry. In principle, the problem is to analyze the changes in the correlation function under the influence of the process of the integral filter with the weight function, the “inverse problem” is considered - the output signal is assumed to be known, the parameters of the input signal to be determined. The idealization used in this case consists in the assumption of the stationary of the initial process, as well as the difference structure of the weight function. The paper continues the mathematical description of the action of the linear integral operator on a random function described in the book [6], §7.

The object of research is a two-channel unreliable queueing loss system. The in-coming flow of requests is considered to be simplest. The rest of random variables, de-scribing the system operation, are general ones. During request service the failure of channel can occur. In this case, the service goes on by means of random time reserve. Time reserve can be enough to complete service or to restore the channel. In the latter case, request service by the channel goes on. In case of short reserve, the request is lost. By means of the apparatus of theory of semi-Markov processes with discrete-continuous states mathematical model of the queuing system is built. Final probabilities of different physical states and average stationary sojourn times in these states are obtained.

The paper deals with features of a complex heat exchange in screwshaped coil heating surfaces of once-through steam generator. To clarify design characteristics that provide mg augmentation, investigation of factors that affect boiler's technical characteristics is carried out. It should be pointed out, that a great contribution to mg augmentation of complex heat exchange is caused by imperforated heating surface roughnesses, heating surface curvature, creating flow turbulence of the combustion gases based on aerodynamic flow orificing by impacted laps of coil. That leads to increasing of industrial safety and reduction of boiler’s gabarit and weight in comparison with triple-pass boilers.

In this paper algorithm for temperature correction of physical quantities sensors, uses automatic correction of real static sensor transform function, is studied. For obtaining correction function polynomial approximation and spline approximation of empirical data were used. The efficiency of using linear spline was proved as well as advantages of this method against polynomial approximation and cubic spline in real-time mode were illustrated.

The paper presents a unified concept of improving the metrological characteristics that determine the criteria for the synthesis of measuring instruments. Methods for measuring the integral characteristics are considered, using the spatial separation of the instantaneous values of harmonic signals with the formation of additional signals. The results of the analysis of the influence of the error due to the non-ideal phase-shifting blocks providing the formation of additional signals are given. The results obtained make it possible to choose the appropriate hardware depending on the requirements for the accuracy of the measurement.

In many devices when triggered arise impact a massive elements. The impact can be as one of the main stages of the process of operation, determining the transmission of mechanical energy to the load, also unwanted constraint resource settings. These required when calculation of collision force and mechanical stress is very important. The article proposed a computer model for calculating process of impact of massive elements of seismic waves source. The model is presented in the form of a diagram, including mechanical and acoustic subsystems. It allows using simple actions to group in one calculation processes in the subsystems of different physical nature. The model allows us to perform multiple test devices, which is in the process of actuation are very important stages of energy transfer by shock-interaction of the massive elements, and other devices, the characteristics of which are to some extent determined by the presence of interactions of shock type.

Servo drives are the main ones when submitting the moving parts of the machine and realizing complex movements of the tools. The dynamics of electric drives determines the accuracy of processing or changes. To achieve high dynamic quality of control, it is necessary to provide an aperiodic transition process from one speed to another. In this case, high positioning accuracy and better cleanliness of the workpiece are ensured. The paper considers the necessary conditions for providing an aperiodic transient process in a digital control system for the rotational speed of an electric motor. The paper describes the method of additional correction of the system providing the required parameters. The theoretical positions are confirmed by the results of the simulation.

The results of numerical modeling of the process of soft microwave drying of capillary-porous material in a ray type microwave chamber with the use of a horn antenna are presented. A mathematical model of the microwave drying process of a dielectric based on coupled equations of electrodynamics and heat and mass transfer is proposed. Mathematical modeling was carried out using the finite element method implemented in the COMSOL Multiphysics software. The model takes into account the change in dielectric permittivity and dielectric loss factor in the drying process, depending on its moisture content.

Trouble-free operation of the PSS distribution networks with dead-earthed neutral up to 1000 volts largely depends on the frequency of single-phase short-circuit (SC), which are the most common type of insulation failure. Existing short-circuit protection devices in networks with earthed neutraltrigger in the event of short circuit, that is workin the event of the fault, but a rather long-term process of insulation defect development is not detected. In connection with this the assessment of the PSS distribution network isolation under operating voltage proves to be important. Development of scientific and technical solutions that enhance safety in the operation of power systems with earthed neutral is aimed at achieving the above-mentioned goals. The goal is achieved through the provision of objective monitoring of the state of electrical insulation leakage current. This allows to significantly reduce the risk of short-circuit due to early detection of developing insulation defect. The article offers the concept of system of electrical insulation with earthed neutral control and diagnostics, which allows to transfer from the fight with the consequences of insulation damage to its prevention and to a significant increase in its electro- and fire safety.

This paper is about the integration of the control valves in the gas and oil plant models that can be created by MiR PiA software. As example, a model of the simple part of the plant is shown. This model contains the pipeline with the control valve. A configuration of the calculation sequence is shown. A hydraulics calculation results are described for two cases. In the first case hydraulic line can work in the normal mode. In the second case the pressure drop is too big. An adoption of these models can help staff solve several problems, such as different raw material using, productivity increase, assurance of product quality problems, etc.