An Investigation of Controlling Two-Peak Heat Release Rate for Combustion Noise Reduction in Split-Injection PCCI Engine using Numerical Calculation

2014 ◽  
Author(s):  
Hiroki Ikeda ◽  
Norimasa Iida ◽  
Hiroshi Kuzuyama ◽  
Tsutomu Umehara ◽  
Takayuki Fuyuto
Keyword(s):  
Numerical Calculation ◽  
Heat Release ◽  
Noise Reduction ◽  
Heat Release Rate ◽  
Release Rate ◽  
Combustion Noise ◽  
Split Injection ◽  
Peak Heat Release Rate

scholarly journals The effect of intumescent mat on post-fire performance of carbon fibre reinforced composites

2019 ◽  
Vol 37 (3) ◽  
pp. 257-272 ◽  
Author(s):  
Chenkai Zhu ◽  
Jingjing Li ◽  
Mandy Clement ◽  
Xiaosu Yi ◽  
Chris Rudd ◽  
...  
Keyword(s):  
Carbon Fibre ◽  
Heat Release ◽  
Heat Release Rate ◽  
Release Rate ◽  
Reinforced Composites ◽  
Fire Performance ◽  
Total Heat Release ◽  
Reinforced Composite ◽  
Peak Heat Release Rate ◽  
Fibre Reinforced Composites

This study investigated the effect of intumescent mats (M1 and M2) with different compositions on the post-fire performance of carbon fibre reinforced composites. The sandwich structure was designed for composites where M1 (carbon fibre reinforced composite-M1) or M2 (carbon fibre reinforced composite-M2) mats were covered on the composite surface. A significant reduction in the peak heat release rate and total heat release was observed from the cone calorimetric data, and carbon fibre reinforced composite-M1 showed the lowest value of 148 kW/m2 and 29 MJ/m2 for peak heat release rate and total heat release, respectively. In addition, a minor influence on mechanical properties was observed due to the variation of composite thickness and resin volume in the composite. The post-fire properties of composite were characterised, and the M1 mat presented better retention of flexural strength and modulus. The feasibility of two-layer model was confirmed to predict the post-fire performance of composites and reduce the reliance on the large amounts of empirical data.

Numerical Simulation on Spreading Characteristic of Coach Fire

2012 ◽  
Vol 518-523 ◽  
pp. 1269-1272 ◽  
Author(s):  
Liang Yi ◽  
Jie Chen
Keyword(s):  
Fluid Dynamics ◽  
Numerical Simulation ◽  
Computational Fluid Dynamics ◽  
Heat Release ◽  
Heat Release Rate ◽  
Fire Protection ◽  
Release Rate ◽  
Software Package ◽  
Maximum Temperature ◽  
Peak Heat Release Rate

The aim of this work is to study the burning characteristics of coach fire. With application of computational fluid dynamics (FDS software package), coach fires caused by arson are simulated under different ventilation conditions. Variation of heat release rate (HRR) and distribution of temperature are analyzed. Peak heat release rate of coach fire caused by arson in passenger carriage can reach about 24 MW and maximum temperature in the carriage is over 1000 °C. Results of this study can be referred for fire protection and rescue design of coach.

Impact of Flashover Fire Conditions on Exposed Energized Electrical Cords and Cables

2019 ◽  
Author(s):  
Craig Weinschenk ◽  
◽  
Daniel Madrzykowski ◽  
Paul Courtney
Keyword(s):  
Heat Release ◽  
Heat Release Rate ◽  
Release Rate ◽  
Circuit Breaker ◽  
Thermal Exposure ◽  
Ground Fault ◽  
Peak Heat Release Rate ◽  
Different Types ◽  
Protection Devices ◽  
Fuel Source

A set of experiments was conducted to expose different types of energized electrical cords for lamps, office equipment, and appliances to a developing room fire exposure. All of the cords were positioned on the floor and arranged in a manner to receive a similar thermal exposure. Six types of cords commonly used as power supply cords, extension cords, and as part of residential electrical wiring systems were chosen for the experiments. The non-metallic sheathed cables (NMB) typically found in residential electrical branch wiring were included to provide a link to previous research. The basic test design was to expose the six different types of cords, on the floor of a compartment to a growing fire to determine the conditions under which the cord would trip the circuit breaker and/or undergo an arc fault. All of the cords would be energized and installed on a non-combustible surface. Six cord types (18-2 SPT1, 16-3 SJTW, 12-2 NM-B, 12-3 NM-B, 18-3 SVT, 18-2 NISPT-2) and three types of circuit protection (Molded case circuit breaker (MCCB), combination Arc-fault circuit interrupter (AFCI), Ground-fault circuit interrupter (GFCI)) were exposed to six room-scale fires. The circuit protection was remote from the thermal exposure. The six room fires consisted of three replicate fires with two sofas as the main fuel source, two replicate fires with one sofa as the main fuel source and one fire with two sofas and MDF paneling on three walls in the room. Each fuel package was sufficient to support flashover conditions in the room and as a result, the impact on the cords and circuit protection was not significantly different. The average peak heat release rate of the sofa fueled compartment fires with gypsum board ceiling and walls was 6.8 MW. The addition of vinyl covered MDF wall paneling on three of the compartment walls increased the peak heat release rate to 12 MW, although most of the increased energy release occurred outside of the compartment opening. In each experiment during post flashover exposure, the insulation on the cords ignited and burned through, exposing bare conductor. During this period the circuits faulted. The circuit protection devices are not designed to provide thermal protection, and, thus, were installed remote from the fire. The devices operated as designed in all experiments. All of the circuit faults resulted in either a magnetic trip of the conventional circuit breaker or a ground-fault trip in the GFCI or AFCI capable circuit protection devices. Though not required by UL 1699, Standard for Safety for Arc-Fault Circuit-Interrupters as the solution for detection methodology, the AFCIs used had differential current detection. Examination of signal data showed that the only cord types that tripped with a fault to ground were the insulated conductors in non-metallic sheathed cables (12-2 NM-B and 12-3 NM-B). This was expected due to the bare grounding conductor present. Assessments of both the thermal exposure and physical damage to the cords did not reveal any correlation between the thermal exposure, cord damage, and trip type.

Study on Flame-Retardant Properties of Flame Retardant Asphalt Mixture

2013 ◽  
Vol 438-439 ◽  
pp. 387-390 ◽  
Author(s):  
Da Liang Liu ◽  
Yi Zhong Yan ◽  
Yun Yong Huang ◽  
Jia Liang Yao ◽  
Jian Bo Yuan
Keyword(s):  
Heat Release ◽  
Flame Retardant ◽  
Heat Release Rate ◽  
Release Rate ◽  
Flame Retardants ◽  
Asphalt Mixture ◽  
Modified Asphalt ◽  
Peak Heat Release Rate ◽  
Flame Retardant Properties ◽  
Sbs Modified Asphalt

Flame retardants modified asphalt with SBS flame retardant SMA hybrid material was prepared, flame retardant performances of SMA mixture was studied by the cone calorimeter. The results show that adding 12% flame retardant with SBS modified asphalt in preparation of flame retardant SMA mixture, the peak heat release rate values than the non-flame retardant asphalt mixture decreased by 4.02 kW/m2, and the heat release rate values were significantly reduced, the total heat and the amount of smoke of flame retardant asphalt mixture released less than the non-flame retardant asphalt mixture.

Flame Retardation of Natural Bamboo Fiber/ Polypropylene Fiber Non-Woven Materials

2011 ◽  
Vol 105-107 ◽  
pp. 1723-1726
Author(s):  
Wei Ma ◽  
Wen Bin Yao
Keyword(s):  
Heat Release ◽  
Flame Retardant ◽  
Heat Release Rate ◽  
Release Rate ◽  
Cone Calorimeter ◽  
Polypropylene Fiber ◽  
Bamboo Fiber ◽  
Peak Heat Release Rate ◽  
Natural Bamboo Fiber ◽  
Flame Retardation

According to Natural Bamboo Fiber/ Polypropylene fiber(PP) non-woven materials encountered the problem that its flame retardation is insufficient, this paper tried to add flame retardant to improve its performance, then the cone calorimeter was used to evaluate its flammability. The results show that Peak-Heat Release Rate and Smoke Release Rate etc significantly improved. In accordance with the UL94 ,the flame retardation meet the level V-0 , consistent with the requirements of enterprise.

Estimation of Peak Heat Release Rate of a Forest Fuel Bed in Outdoor Laboratory Conditions

2010 ◽  
Vol 29 (1) ◽  
pp. 53-70 ◽  
Author(s):  
J. Madrigal ◽  
M. Guijarro ◽  
C. Hernando ◽  
C. Díez ◽  
E. Marino
Keyword(s):  
Heat Release ◽  
Heat Release Rate ◽  
Release Rate ◽  
Laboratory Conditions ◽  
Peak Heat Release Rate ◽  
Forest Fuel

Flame Retardancy of Laponite- and Montmorillonite-Based Nylon 6 Nanocomposites

2003 ◽  
Vol 788 ◽  
Author(s):  
Gunes Inan ◽  
Prabir K. Patra ◽  
Yong K. Kim ◽  
Steven B. Warner
Keyword(s):  
Mass Loss ◽  
Heat Release ◽  
Heating Rate ◽  
Heat Release Rate ◽  
Flame Retardancy ◽  
Release Rate ◽  
Barrier Properties ◽  
Nylon 6 ◽  
Release Rates ◽  
Peak Heat Release Rate

ABSTRACTThe flame retardancy of nylon 6/laponite and nylon 6/montmorillonite nanocomposites was investigated. The pronounced effect of layered silicates on heat release and mass loss rates of nylon 6 was examined. We found that nylon 6/laponite has 46 % and nylon 6/montmorillonite has 52.5 % lower peak heat release rates than that of neat nylon 6. The 6.5 % difference between the peak heat release rates of laponite- and montmorillonite-based nanocomposites was attributed to differences in aspect ratio and surface charge density of the nanoparticles.The barrier properties of nanocomposite chars was evaluated by examining the peak heat release and mass loss rate reductions of stacks of layers, with the bottom layer being neat nylon 6 polymer and the top layers being nanocomposites that formed chars during the experiments. We observed that the peak heat release rate of a 10×10×0.3 cm neat nylon 6 slab was reduced by about 45 % when protected with a char-forming nylon 6/montmorillonite slab of same dimensions. The dramatic reduction of the peak heat release rate of neat nylon 6 when covered with a nanocomposite char was consistent with the notion that the flame retardancy of polymer/clay nanocomposites is affected by the (thermal and/or mass) barrier properties of the char. In order to test the thermal insulation of the char, temperature profiles of the layered samples were measured during cone calorimeter experiments. We observed that the nanocomposite char that brought about a 44.5 % reduction in peak heat release and mass loss rates reduced the heating rate of the same neat nylon 6 by about 31.2 %. The reduction in the heating rate increased with the amount of nanocomposite char formed.

Diethyl Ether as an Ignition Enhancer for Naphtha Creating a Drop in Fuel for Diesel

2016 ◽  
Author(s):  
R. Vallinayagam ◽  
S. Vedharaj ◽  
S. Mani Sarathy ◽  
Robert W. Dibble
Keyword(s):  
Heat Release ◽  
Heat Release Rate ◽  
Release Rate ◽  
Ignition Delay ◽  
Cetane Number ◽  
Cylinder Pressure ◽  
Auto Ignition ◽  
Peak Heat Release Rate ◽  
Ignition Characteristics ◽  
Ci Engines

Direct use of naphtha in compression ignition (CI) engines is not advisable because its lower cetane number negatively impacts the auto ignition process. However, engine or fuel modifications can be made to operate naphtha in CI engines. Enhancing a fuel’s auto ignition characteristics presents an opportunity to use low cetane fuel, naphtha, in CI engines. In this research, Di-ethyl ether (DEE) derived from ethanol is used as an ignition enhancer for light naphtha. With this fuel modification, a “drop-in” fuel that is interchangeable with existing diesel fuel has been created. The ignition characteristics of DEE blended naphtha were studied in an ignition quality tester (IQT); the measured ignition delay time (IDT) for pure naphtha was 6.9 ms. When DEE was added to naphtha, IDT decreased and D30 (30% DEE + 70% naphtha) showed comparable IDT with US NO.2 diesel. The derived cetane number (DCN) of naphtha, D10 (10% DEE + 90% naphtha), D20% DEE + 80% naphtha) and D30 were measured to be 31, 37, 40 and 49, respectively. The addition of 30% DEE in naphtha achieved a DCN equivalent to US NO.2 diesel. Subsequent experiments in a CI engine exhibited longer ignition delay for naphtha compared to diesel. The peak in-cylinder pressure is higher for naphtha than diesel and other tested fuels. When DEE was added to naphtha, the ignition delay shortened and peak in-cylinder pressure is reduced. A 3.7% increase in peak in-cylinder pressure was observed for naphtha compared to US NO.2 diesel, while D30 showed comparable results with diesel. The pressure rise rate dropped with the addition of DEE to naphtha, thereby reducing the ringing intensity. Naphtha exhibited a peak heat release rate of 280 kJ/m3deg, while D30 showed a comparable peak heat release rate to US NO.2 diesel. The amount of energy released during the premixed combustion phase decreased with the increase of DEE in naphtha. Thus, this study demonstrates the suitability of DEE blended naphtha mixtures as a “drop-in” replacement fuel for diesel.

Accuracy of Diesel Engine Combustion Metrics Over the Full Range of Engine Operating Conditions

2018 ◽  
Author(s):  
Peter G. Dowell ◽  
Richard D. Burke ◽  
Sam Akehurst
Keyword(s):  
Heat Release ◽  
Heat Release Rate ◽  
Release Rate ◽  
Full Range ◽  
Operating Conditions ◽  
Strong Impact ◽  
Combustion Analysis ◽  
Operating Range ◽  
Peak Heat Release Rate ◽  
Holistic Understanding

Measuring and analyzing combustion is a critical part of the development of high efficiency and low emitting engines. Faced with changes in legislation such as Real Driving Emissions and the fundamental change in the role of the combustion engine with the introduction of hybrid-electric powertrains, it is essential that combustion analysis can be conducted accurately across the full range of operating conditions. In this work, the sensitivity of five key combustion metrics is investigated with respect to eight necessary assumptions used for single zone Diesel Combustion analysis. The sensitivity was evaluated over the complete operating range of the engine using a combination of experimental and modelling techniques. This provides a holistic understanding of combustion measurement accuracy. For several metrics, it was found that the sensitivity at the mid speed/load condition was not representative of sensitivity across the full operating range, in particular at low speeds and loads. Peak heat release rate and indicated mean effective pressure were found to be most sensitive to the determination of top dead center (TDC) and the assumption of in-cylinder gas properties. An error of 0.5° in the location of TDC would cause on average a 4.2% error in peak heat release rate. The ratio of specific heats had a strong impact on peak heat release with an error of 8% for using the assumption of a constant value. A novel method for determining TDC was proposed which combined a filling and emptying simulation with measured data obtained experimentally from an advanced engine test rig with external boosting system. This approach improved the robustness of the prediction of TDC which will allow engineers to measure accurate combustion data in operating conditions representative of in-service applications.

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