Flue Gas Removal Systems Are a Key Issue in the Application of Condensing Boilers

This article is devoted to the most pressing issue of the use of condensing boilers in Russia for autonomous heat supply systems - the organization of smoke removal. If we compare a standard gas boiler with its condensing counterpart, then we can come to the conclusion that their differences lie not only in some innovations, but in radically different principles of operation. Yes, in both cases, the heating of the coolant occurs due to the combustion of the gas, but in the condensing boiler, the heating of the coolant is additionally performed with the help of exhaust gases. Moreover, the smoke removal system in this case produces the primary heating of the liquid - the exhaust gases, which contain a large amount of water vapor, first heat the coolant, and only then directly the gas heats it up to the specified temperature. It is thanks to all this that fuel savings occur - the efficiency of condensing boilers is 15-20% higher compared to standard units of this type. The set of domestic directives and regulations on autonomous heat supply in individual issues, focusing on foreign developments, at the same time has significant features in the requirements for the design and operating conditions of combustion products removal systems, especially for condensing boilers.

NUMERICAL INVESTIGATION ON SMOKE MANAGEMENT IN UNDERGROUND BRANCHED TUNNELS

Soot is perhaps the most harmful element in vehicle tunnels fire as smoke moves harmonize with the way passengers flee. It decreases visibility and can cause suffocation fatalities. This paper presents an empirical analysis on the effect of removing smoke through different ventilation systems on smoke distribution inside the vehicle tunnel, such as water mist system with transverse ventilation with several extractions of exhaust fans Sustainable human conditions were also tested. FDS 2019 ver. was used to predict temperature, visibility, and concentration of co. Motivation/Background: Present work to investigate the effect of extracting the smoke by different system of ventilation on smoke spread inside the vehicular tunnel. Method: By FDS 2019 that used governing equations and naver-stocks equations. Results: We predicted in this paper smoke spread, temperature distribution, co concentration distribution and visibility. Conclusions: This study looks at the importance of smoke control generally as well as the smoke control criteria in the automotive tunnel configuration which acknowledged them. Because the smoke barrier water mist screen with a transverse ventilation device improves the smoke removal technique. FDS is a valuable method for simulating smoke diffusion as well as other effects.

Translucent Glass Roofs For Large-Span Coverings

The article deals with the issues of glass use in the enclosing structures of large-span coverings, which have such advantages as ensuring the penetration of natural light, tightness, minimum labor costs for repair and maintenance. Design shortcomings: the high cost, the need for protection of the internal volume against the penetrating sun rays in the warm season (hothouse effect); arrangement of devices for operation of a roof. The key technical properties and characteristics of glass panels and pane-glass sets, constructive decisions, including interface to the main bearing structures of a large-span covering are given. Peculiarities of their design with due regard for ventilation and smoke removal, a drainage of condensate, ways of fight against frosting and snow drifts on the roof are reflected. Features of the account of loadings, the basic approaches to their calculation are considered. Various design solutions for the spatial metal trussed systems with the original nodal connections are presented. Information on modern solutions of translucent roofs using glass for large-span coverings is given.