scholarly journals Combustible Material Content vs. Fire Properties of Electric Cables

Energies ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 6172
Author(s):  
Katarzyna Kaczorek-Chrobak ◽  
Jadwiga Fangrat
Keyword(s):  
Heat Release ◽  
Combustion Process ◽  
Test Method ◽  
Zinc Borate ◽  
Infrared Analysis ◽  
Chemical Structures ◽  
Smoke Production ◽  
Outer Sheath ◽  
Electric Cables ◽  
Fire Properties

The fire load of buildings is significantly increased by means of electric cables, usually creating a long combustible base for fire to spread and in this way decreasing the fire safety of buildings. The aim of the study was to evaluate a relationship between the construction of the cables and their fire properties, especially the mass loss influence on other fire properties of cables. Six cables of different core numbers were tested by means of the standard test method EN 50399. Additionally, thermogravimetric analysis and Attenuated Total Reflection—Fourier Transform Infrared analysis were performed on the separate outer sheath, bedding, and core insulations in order to determine the similarity of the materials’ chemical structures. It was found that: (1) the construction of the cable strongly influences the fire behavior due to the creation of a barrier for flame penetration and emission of combustion effluents though inside the closed agglomeration of non-combustible metallic cores (conductors), and the intumescent structures formed from aluminum trihydrate/zinc borate fillers and fire retardants in outer sheath material during the self-sustained combustion process after ignition of cables; (2) the inhomogeneous distribution of non-combustible inorganic fillers or different contents of fillers and flame retardants within the polymer fraction cause an unobvious fire behaviors of cables; and (3) the use of bedding in multicore cable construction results in lower values of combustion parameters (maximum average heat release rate, total heat release, maximum average smoke production rate, total smoke production), e.g., better fire properties of cables.

scholarly journals The Effect of RME-1-Butanol Blends on Combustion, Performance and Emission of a Direct Injection Diesel Engine

Energies ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2941
Author(s):  
Wojciech Tutak ◽  
Arkadiusz Jamrozik ◽  
Karol Grab-Rogaliński
Keyword(s):  
Diesel Engine ◽  
Heat Release ◽  
Direct Injection ◽  
Specific Energy Consumption ◽  
Combustion Process ◽  
Constant Load ◽  
Combustion Stability ◽  
Performance And Emission ◽  
Energy Share ◽  
The Stability

The main objective of this study was assessment of the performance, emissions and combustion characteristics of a diesel engine using RME–1-butanol blends. In assessing the combustion process, great importance was placed on evaluating the stability of this process. Not only were the typical COVIMEP indicators assessed, but also the non-burnability of the characteristic combustion stages: ignition delay, time of 50% heat release and the end of combustion. The evaluation of the combustion process based on the analysis of heat release. The tests carried out on a 1-cylinder diesel engine operating at a constant load. Research and evaluation of the combustion process of a mixture of RME and 1-butanol carried out for the entire range of shares of both fuels up to 90% of 1-butanol energetic fraction. The participation of butanol in combustion process with RME increased the in-cylinder peak pressure and the heat release rate. With the increase in the share of butanol there was noted a decrease in specific energy consumption and an increase in engine efficiency. The share of butanol improved the combustion stability. There was also an increase in NOx emissions and decrease in CO and soot emissions. The engine can be power by blend up to 80% energy share of butanol.

Comparison of silicate impregnation methods to reinforce Chinese fir wood

Holzforschung ◽  
2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Ping Li ◽  
Yuan Zhang ◽  
Yingfeng Zuo ◽  
Yiqiang Wu ◽  
Guangming Yuan ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Heat Release ◽  
Flame Retardancy ◽  
Chinese Fir ◽  
Smoke Suppression ◽  
Impregnation Method ◽  
Residual Rate ◽  
Smoke Production ◽  
Human Respiration ◽  
Strengthen Effect

AbstractInorganic impregnation strengthening of Chinese fir wood was carried out to improve the strength, dimensional stability, flame retardancy, and smoke suppression of Chinese fir wood. Sodium silicate was used as reinforcement, a sulfate and phosphate mixtures were used as a curing agent, and Chinese fir wood was reinforced by the respiratory impregnation method (RIM) that imitating human respiration and vacuum progressive impregnation method (VPIM). The weight percentage gain (WPG), density increase rate, distribution of modifier, bending strength (BS), compressive strength (CS), hardness, and water resistance of unreinforced Chinese fir wood from the VPIM and RIM were compared. It was found that RIM could effectively open the aspirated pits in Chinese fir wood, so its impregnation effect, strengthen effect and dimension stabilization effects were the best. RIM-reinforced Chinese fir wood was filled with silicate both horizontally and vertically. At the same time, the transverse permeability of silicate through aspirated pits was significantly improved. The chemical structure, crystalline structure, flame retardancy, smoke suppression, and thermal stability of VPIM- and RIM-reinforced Chinese fir wood were characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), cone calorimeter (CONE), and thermogravimetric analysis (TGA). The results indicated that although the crystallinity of RIM-reinforced Chinese fir wood decreased the most, more chemical crosslinking and hydrogen bonding were formed in the wood, and the strengthen effect was still the best. Compared with VPIM-reinforced Chinese fir wood, RIM-reinforced Chinese fir wood had lower heat release rate (HRR), peak-HRR, mean-HRR, total heat release (THR), smoke production rate (SPR), and total smoke production (TSP), higher thermal decomposition temperature and residual rate. It was indicated that RIM-reinforced Chinese fir wood was a better flame retardant, and has a smoke suppression effect, thermal stability, and safety performance in the case of fire.

scholarly journals Combustion Thermodynamics of Ethanol, n-Heptane, and n-Butanol in a Rapid Compression Machine with a Dual Direct Injection (DDI) Supply System

Energies ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2729
Author(s):  
Ireneusz Pielecha ◽  
Sławomir Wierzbicki ◽  
Maciej Sidorowicz ◽  
Dariusz Pietras
Keyword(s):  
Heat Release ◽  
Combustion Chamber ◽  
Internal Combustion Engines ◽  
Direct Injection ◽  
Combustion Process ◽  
Combustion Efficiency ◽  
Injection System ◽  
Rapid Compression Machine ◽  
Process Indicators ◽  
Rapid Compression

The development of internal combustion engines involves various new solutions, one of which is the use of dual-fuel systems. The diversity of technological solutions being developed determines the efficiency of such systems, as well as the possibility of reducing the emission of carbon dioxide and exhaust components into the atmosphere. An innovative double direct injection system was used as a method for forming a mixture in the combustion chamber. The tests were carried out with the use of gasoline, ethanol, n-heptane, and n-butanol during combustion in a model test engine—the rapid compression machine (RCM). The analyzed combustion process indicators included the cylinder pressure, pressure increase rate, heat release rate, and heat release value. Optical tests of the combustion process made it possible to analyze the flame development in the observed area of the combustion chamber. The conducted research and analyses resulted in the observation that it is possible to control the excess air ratio in the direct vicinity of the spark plug just before ignition. Such possibilities occur as a result of the properties of the injected fuels, which include different amounts of air required for their stoichiometric combustion. The studies of the combustion process have shown that the combustible mixtures consisting of gasoline with another fuel are characterized by greater combustion efficiency than the mixtures composed of only a single fuel type, and that the influence of the type of fuel used is significant for the combustion process and its indicator values.

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