Phase-chronometric diagnostic system for main drive of rolling mill

Author(s):  
V. I. Pronyakin ◽  
L. Kh. Minyazeva

At present at the diagnostic of metallurgical equipment state, expert methods of evaluation are prevailed which have subject character. To solve the problem of information-metrological support of rolling mill stand effectively, a phase-chronometric method was proposed, elaborated in N.E. Bauman Moscow State Technical University. It was shown that increase of quality of measuring diagnostical information is provided by transfer from amplitude to chronometric scale and means of its realization at relative errors about 5×10‒4 % at the industrial frequency. At the phase-chronometric method, precision measuring of time intervals, correspondent to the phases intervals of the working cycle is used, depending on characteristic features of motion of a mechanism elements. In contrast to vibro-diagnostic method, by using the phase-chronometric method, the change of operation mode of rolling equipment can be defined hundred times quicker. Cyclicity of a mechanism motion and minimal scattering of measurement results at accomplishing working cycle enable to reveal stable in time diagnostic features and individual quantitative parameters values, which characterize technical state of a rolling mill. The proposed phase-chronometric system consists of an angle sensor of position (incremental encoder), system of information collection and defining of time intervals and personal computer with application software. The system of information collection and defining of time intervals is realized based on a plate, functionally uniting high-stability pulse generator, scale convertor, counter, measuring pulse generator and chrono-comparator. The embedded systems to realize the phase-chonometric metod are simple and reliable in operation. To realize the phase-chronometric method, a mathematical model was elaborated, comprising a system of differential equations, describing interaction of the package of interrelated multi-mass torsion systems. It was showed that verified mathematical model enabled quickly to reveal defects in a rolling mill operation.

Author(s):  
E.T. Plaksina ◽  
A.B. Syritsky ◽  
A.S. Komshin

The article considers the main methods of internal combustion engine diagnostics. A method based on measuring the time intervals between the phases of the working cycle of the mechanism is described. An algorithm for measuring the time intervals from the formulation of the problem to the proof of the efficiency of this method on an internal combustion engine has been determined. The installation of the angle sensor on the crankshaft of the experimental bench engine VAZ 21126 is shown. The basis for the construction of a mathematical model of the crankshaft is presented and the main factors influencing its movement are identified. A criterion has been established according to which the misfire is determined most accurately. The results obtained can be used for developing diagnostic systems for internal combustion engines, as well as engines operating in extreme conditions, for example, beyond the Arctic Circle, on ships, etc.


2010 ◽  
Vol 73 (8) ◽  
pp. 1502-1505 ◽  
Author(s):  
WENJING PAN ◽  
DONALD W. SCHAFFNER

Tomato-associated Salmonella outbreaks have recently become a significant food safety concern. Temperature abuse of cut tomatoes may have played a role in some of these outbreaks. The purpose of this study was to develop a mathematical model to describe the growth of Salmonella on cut tomatoes at various temperatures. Four Salmonella serotypes (Typhimurium, Newport, Javiana, and Braenderup) obtained from previous tomato-linked cases of salmonellosis were used in this study. These four serotypes were cultured separately, combined into a cocktail, and inoculated onto whole red round tomatoes and allowed to dry overnight. The tomatoes were then cut into pieces and incubated at a predetermined range of temperatures (10, 12.5, 15, 17.5, 20, 22.5, 25, 27.5, 30, and 35°C). Salmonella concentration was measured at specified time intervals to determine the growth curve for Salmonella on cut tomatoes at each temperature. The growth rates were calculated using DMFit and used to build a mathematical model to illustrate the relationship between the growth rates of Salmonella on tomatoes and incubation temperatures from 10 to 35°C. The resulting model compared favorably with a Salmonella growth model for raw poultry developed by our laboratory. The Pathogen Modeling Program underpredicted growth at low temperatures and overpredicted growth at high temperatures. ComBase predicted consistently slower growth rates than were observed in tomatoes but showed parallel increases in growth rate with increasing temperature.


2019 ◽  
Vol 946 ◽  
pp. 818-822 ◽  
Author(s):  
Nikita S. Deryabin

The hot deformation behavior of the Inconel alloy 625 was investigated through compression test within the temperature range of 850–1250 °C and the strain rate range of 0.1–30 s−1. Physically based mathematical model involving dynamic recovery and dynamic recrystallization processes has been proposed. Mathematical model allowed to calculate technological parameters of a rolling process of the “Inconel 625” at the hot rolling mill 2300. The pilot rolling operations showed that the possibility of the “Inconel 625” production exists. But it is necessary to provide the design changes of the cooling system of the work rolls. The article addressed the cracking behavior of nickel alloys in industries such as chemical process, nuclear generation, aircraft engine production.


2018 ◽  
Vol 193 ◽  
pp. 03007 ◽  
Author(s):  
Sergei Kolodyazhniy ◽  
Vladimir Kozlov

Using an integral mathematical model of a fire considering the assumptions typical of a starting stage of a fire, analytical dependencies were obtained for determining the time of reaching a critical value of the density of a smoke screen in a premises with a fire epicenter and adjoining premises. By means of analytical formulas for determining critical evacuation time intervals based on visibility loss, table values for different parameters that are included in the original equations were obtained. Simple engineering analytical solutions that describe the dynamics of smoke formation in premises in case of a fire when used in a certain combination are presented. The obtained dependencies allow one to identify the critical time of evacuation with no use of special PC software as well as to obtain original data without calculating an anti-smoke ventilation system.


2020 ◽  
Vol 164 ◽  
pp. 13006 ◽  
Author(s):  
Kirill Kobzev ◽  
Sergey Vyalov ◽  
Alexander Rybak

The article discusses the control system of a hydraulic power source of constant pressure, which is a pump-storage power source, equipped with the original design of the automatic unloading of the hydraulic pump, which provides relay switching of its operation mode. A mathematical model is proposed, obtained using a modeling technique based on the application of the theory of volumetric rigidity of hydraulic systems and their elements. The results of a numerical experiment carried out by numerically solving the equations that make up the mathematical model of a power source are also presented. As a result of a numerical experiment, the main technical capabilities of the considered power source and the influence of its main structural parameters and functional features of the system on operational properties are revealed. The results showed that due to changes in various design parameters of the unloading machine, you can not only change the upper (maximum) and lower (minimum) values of the battery charging pressure, but also adjust their difference depending on the requirements for the power source. The main property of a power source with an automatic unloading device of the proposed design, confirmed as a result of a numerical experiment, is that the automatic unloading device provides a clear relay switching of the pump operation mode from unloading to operating mode and vice versa. The revealed properties make it very promising to use a pump-accumulator power source in the hydraulic systems of mobile machines and technological equipment.


2020 ◽  
Vol 175 ◽  
pp. 05042
Author(s):  
Kirill Kobzev ◽  
Sergey Vyalov ◽  
Alexander Rybak

The article discusses the control system of a hydraulic power source of constant pressure, which is a pump-storage power source, equipped with the original design of the automatic unloading of the hydraulic pump, which provides relay switching of its operation mode. A mathematical model is proposed, obtained using a modeling technique based on the application of the theory of volumetric rigidity of hydraulic systems and their elements. The results of a numerical experiment carried out by numerically solving the equations that make up the mathematical model of a power source are also presented. As a result of a numerical experiment, the main technical capabilities of the considered power source and the influence of its main structural parameters and functional features of the system on operational properties are revealed. The results showed that due to changes in various design parameters of the unloading machine, you can not only change the upper (maximum) and lower (minimum) values of the battery charging pressure, but also adjust their difference depending on the requirements for the power source.


2014 ◽  
Vol 989-994 ◽  
pp. 3818-3822
Author(s):  
Heng Jun Zhu ◽  
Zhuo Wang

IC card is a product of microelectronics, computer and information technology, with the development requirements of its wide application and digitized, one-card system will inevitably become a trend. The operation mode of one-card System with "one card, one database, one network", can both realize the norms for user management, but also provide important information for managers. Meanwhile, as an important part of digital one-card systems is one of the foundation works of information collection in the digital environment. It has the great significance for management and decision support of users.


Author(s):  
Vladimir V. Vantsevich ◽  
Jesse R. Paldan ◽  
Jeremy P. Gray

In this paper, a technical concept is described for a power transmitting unit to control the split of power between the drive axles of a 4×4 hybrid-electric vehicle. This new power transmitting unit uses a planetary gear set and eddy current brake to provide a continuously variable gear ratio that can be integrated into the vehicle driveline between the transfer case and front axle. The paper details the electrical and mechanical characteristics of the device, including its operation mode, its mathematical model built from the equations of the planetary gear set and eddy current brake, the optimization equation by which the device will be controlled to improve vehicle slip efficiency, as well as its torque and electrical current usage. Computer simulations are performed on a mathematical model of a 4×4 military truck using the power transmitting unit in conjunction with a series hybrid-electric configuration transmission.


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