Modeling the transfer of radiant energy to a bulk medium in electric furnaces with the upper position of the radiating elements

Author(s):  
A. I. Nizhegorodov

A new design of suspended radiating elements, which was developed for heating systems of electric furnaces with moving hearth platforms and modular-trigger furnaces, is considered. The transfer of radiant energy on the surface of the firing modules and on the flow of expanded vermiculite is simulated. Analytical dependences are obtained for calculating the temperatures of radiating elements, a refractory base and a heat-insulating cover, as well as grains of the material itself. The possibility of a significant increase in the performance of modular-launch furnaces due to the fact that in the areas of pouring out of the firing modules the crowding of vermiculite will not lead to burnout of the radiating elements, as was observed in tape nichrome systems, is shown.

2019 ◽  
Vol 2 (1) ◽  
pp. 29-39 ◽  
Author(s):  
S. G. Konesev ◽  
P. A. Khlyupin

Introduction: the systems of thermal effects on thermo-dependent, viscous and highly viscous liquids under conditions of the Arctic and the Extreme North are considered. Low efficiency and danger of heating systems based on burned hydrocarbons, heated liquids and steam are shown. Electrothermal heating systems used to maintain thermo-dependent fluids in a fluid state are considered. The evaluation of the effectiveness of the application of the most common electrothermal system — heating cables (tapes). The most effective electrothermal system based on induction technologies has been determined. Materials and methods: considered methods of thermal exposure to maintain the fluid properties of thermo-dependent fluids at low extreme temperatures. Results: presents an induction heating system and options for its implementation in the Extreme North and the Arctic. Conclusions: induction heating system to minimize loss of product quality, improve the system performance under changing process conditions, eliminate fire product, to reduce the influence of the human factor.


Author(s):  
Ye.Ye. Nikitin

The current situation in the sphere of district heating is analysed on the basis of use of the cognitive approach. The presence of closed chains of cause-effect relationships of negative factors and conflicts of target settings of the subjects in the field of district heating is shown. The conceptual model of energy efficient modernization of district heating systems is proposed. This model includes indicators of the current status of heat sources, networks and heat consumers, energetic and economic models, restrictions, procedure of forming and analysis of the mutual influence of the recommended projects. The quantitative data on indicators of the current state of district heating systems of the cities of Ukraine are presented. The interrelation between indicators of the current state and projects of energy efficient modernization of district heating systems is shown. Assessment of energy self-sufficiency of municipal district heating systems on condition of thermal modernization of buildings is carried out. The creation of energy management systems at the district heating enterprises is proposed. Bib. 6, Fig. 7, Tab. 5.


2020 ◽  
Vol 80 (2) ◽  
pp. 147-163
Author(s):  
X Liu ◽  
Y Kang ◽  
Q Liu ◽  
Z Guo ◽  
Y Chen ◽  
...  

The regional climate model RegCM version 4.6, developed by the European Centre for Medium-Range Weather Forecasts Reanalysis, was used to simulate the radiation budget over China. Clouds and the Earth’s Radiant Energy System (CERES) satellite data were utilized to evaluate the simulation results based on 4 radiative components: net shortwave (NSW) radiation at the surface of the earth and top of the atmosphere (TOA) under all-sky and clear-sky conditions. The performance of the model for low-value areas of NSW was superior to that for high-value areas. NSW at the surface and TOA under all-sky conditions was significantly underestimated; the spatial distribution of the bias was negative in the north and positive in the south, bounded by 25°N for the annual and seasonal averaged difference maps. Compared with the all-sky condition, the simulation effect under clear-sky conditions was significantly better, which indicates that the cloud fraction is the key factor affecting the accuracy of the simulation. In particular, the bias of the TOA NSW under the clear-sky condition was <±10 W m-2 in the eastern areas. The performance of the model was better over the eastern monsoon region in winter and autumn for surface NSW under clear-sky conditions, which may be related to different levels of air pollution during each season. Among the 3 areas, the regional average biases overall were largest (negative) over the Qinghai-Tibet alpine region and smallest over the eastern monsoon region.


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