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In recent years, with the development of DC transmission projects in China, the number of converter stations has increased. Fire accidents in converter stations have also become more frequent. Transformer insulating paperboard, as a typical combustible material in converter station equipment, poses a greater fire risk. So in this paper, flame spreading behaviors, including experimental visual characteristics, fire spreading rate, mass loss with time and mass loss rate, of transformer insulating paperboard with different thickness and different inclined angles are investigated. The results show that: (1) In downwards flame spread, that is, in the case of positive angle, the flame height and width gradually decrease with the increase of angle; in the case of negatively inclined angles, the flame length shows an increasing trend with the decrease of inclined angles, and the flame thickness gradually becomes thinner. (2) In upwards flame spread, that is, in the case of negative angle, the fire spreading rate of the insulating paperboard decreases sharply with the increase of the angle; In the case of a positively inclined angle, the change of flame spreading rate is not obvious with the increase of inclined angles as compared with the conditions in negative angles. The paperboard thickness also has a significant impact on the flame spreading rate, and the flame spreading rate will decrease significantly with the increase of paperboard thickness. (3) In upwards flame spread, the mass loss rate of insulating paperboard will decrease significantly with the increase of inclined angles; in downwards flame spread, the change of mass loss rate is not obvious with the increase of inclined angles as compared with those in condition of negative angles. At the same time, the mass loss rate will increase significantly with the increase of paperboard thickness. (4) The mass loss rate and fire spread rate of the insulating paperboard have a strong correlation with the flame length and the length of the pyrolysis zone. A heat transfer process model about characteristic length scale and mass loss rate is established. In order to simplify the model, a dimensionless relation about angle is defined to replace the feature length and to explore the relationship between angle and mass loss rate. Based on the inherent relationship between fire spread rate and mass loss rate, the relationship between fire spread rate and angle is found. And the result shows satisfactory agreement between the predictions and experimental results. [ABSTRACT FROM AUTHOR]

After over 30 years of fast economic development and massive construction of infrastructures, China now owns the largest total length of tunnels in the world. However, many tunnels are overloaded with a large traffic volume and vulnerable to fire accidents in operation. Once a fire occurs in the tunnel, the occupants face a dangerous and confined environment and need to evacuate before reaching untenable conditions. Failure in fire evacuation will cause severe injuries and casualties under high-temperature and toxic fire smoke, and many past fire accidents have taught us lessons. Driven by the need for tunnel fire safety in China, many new researches are conducted related to fire evacuation in tunnel environments including full-scale experiments, and new evacuation strategies are carried out with sophisticated tunnel designs and regulations. Hence, this work aims to review these latest developments and studies in China towards better and safer evacuation in tunnel fires. In specific, the paper summarized the evacuation issues in tunnel fires generally and pointed out the unique issues in China. Aiming these issues, the paper then introduced recent evacuation strategies and evacuation research in China respectively. Typical tunnel fire accidents and full-scale tunnel fire evacuation tests in China were discussed in detail as case studies. Detailed evacuation strategies and the exposed issues were analyzed in those tunnel fire accidents emphatically, while evacuation findings of human behavior such as evacuation choices and trajectories were presented according to several field tunnel fire evacuations conducted by the authors. Finally, we highlight the research advances and challenges of fire evacuation in tunnels, as well as the need and directions for future research. [ABSTRACT FROM AUTHOR]

China Power Grid is actively building a new energy-based ultra-high voltage grid system. Therefore, the researches on fire safety of power grid are of great importance. This paper firstly investigates the fire accident characteristics in the substation system. With the focuses on the transformer oil fires, the early detection and early warning, modification, fire monitoring and extinguishing systems of transformer oil are reviewed. It is found that the researches on flowing and jet fires should be reinforced while modified oil and pyrolysis gas detection can be applied for reducing the fire probability. Secondly, the fire risks and characteristics of cables are summarized for the transmission and distribution lines, and the methods of early warning, fire prevention and rescue are analyzed. For the wildfire threatening the transmission and distribution cables, the characteristics of wildfire and corresponding firefighting methods are reviewed. The water mist and liquid nitrogen are identified as the most effective ways of extinguishing cable fires and advanced fire detection and long-range drone fire extinguishing technologies should be improved for wildfires. Finally, the thermal runaway mechanism and fire characteristics of LIB in the energy storage system are summarized, and the difficulties in fire extinguishing are discussed. The application of the existing fire detection system in the field of LIB is proposed, and the early warning indicators for intelligent fire protection are introduced. In the future, the intelligent fire protection systems will improve the safety of energy storage systems, and efficient test platforms and reliable test standards will continue to be demanded to reduce the likelihood of thermal runaway and fire severity. [ABSTRACT FROM AUTHOR]

In the past three decades, fire engineering has experienced fast development worldwide. Fire regulations for building industry were moved from prescriptive description to performance-based specification. This trend started in the UK in the 1980s and spread to other western countries. Hong Kong closely followed the UK development and adopted the approach of performance-based design (PBD) for the Hong Kong International Airport and MTR stations in the early 1990s. The Government of Hong Kong SAR formally recognised the PBD approach in the prescriptive codes of practice in the mid-1990s and developed the performance-based code (PBC) in the 2000s. This PBC was promulgated in 2011. The evolution in fire engineering impacted the fire community in Mainland China. The State Key Laboratory of Fire Science (SKLFS) was established in University of Science and Technology of China (USTC) in 1991. Then fire science and fire engineering stepped into the fast development track. The building industry in Mainland China started to adopt the PBD approach in the early 2000s for the significant developments including large airport terminals, railway and metro stations, super high-rise buildings, and mega commercial centres. However, a structured PBC system is not available within the regulatory framework to date. Adoption of PBD approach is slowing down in recent years. This paper presents a review of fire engineering development in Hong Kong and Mainland China. The review focuses on the development of the PBC in Hong Kong, and the PBD approach and fire research in Mainland China in the past 30 years. [ABSTRACT FROM AUTHOR]

Along with the rapid urbanization and economic growth in China over the last four decades, the higher education in Fire Safety Science and Engineering has been developed and changed significantly. This work systemically reviews the origin and evolution of fire safety higher education history in China, from Fire Protection Technology (before the 1980s) to Fire Safety Science and Engineering (from about 1985 to the 2010s) and to Human-Oriented Public Safety and Smart Firefighting (from the 2010s to today). The scopes of fire safety discipline are discussed by introducing the requirements of firefighters, registered professional fire protection engineers and safety engineers in China. The courses and curriculum in fire safety higher education in representative universities are introduced and compared in detail. By comparing their undergraduate and postgraduate programmes, we explain the context of fire safety education in different universities. From a historical viewpoint, we introduce the unique features and the diversity developed in different institutes, based on the evolution of programme documents and first-hand teaching materials. This review aims to introduce the higher education systems of fire safety in China to the world and encourage more international collaboration with the Chinese fire safety science and engineering communities in the future. [ABSTRACT FROM AUTHOR]

A novel application of correspondence analysis for identifying the relationships between fire loss and time, causes, and locations is proposed. The fire loss is divided into four levels which are [1, 1 k], [1 k, 10 k], [10 k, 100 k], and [100 k, ∞] Yuan (RMB) (1YUAN = 0.1647US, $), where 1 k equals to 1,000 Yuan. The results indicate that the loss levels have significantly related to months, time of day (hour), years, fire causes, and locations. Fires occurring in January, February, and June tend to be strongly associated with the loss level of [1, 1 k], while the loss level of [1 k, 10 k] is more likely to occur in May and August. It shows that September and December have strong relationship with the high loss level of [100 k, ∞]. Regarding the time of day, low loss level of [1, 1 k] is associated with the period from 10 a.m. to 10 p.m.; while high loss levels tend to occur between 2 a.m. and 6 a.m., the level of [1, 1 k] tends to be related to the causes of smoking, playing with fire, and others, while the level of [1 k, 10 k] is mainly caused by the electrical fire and spontaneous combustion. The locations of traffic, production operation places and commerce buildings, have been significantly related to high loss level. This paper introduces the application of correspondence analysis to fire losses, demonstrating the possibility of using CA to identify the relationships between fire losses and influencing factors. The achieved information can improve loss assessment of fires at a given time or location. [ABSTRACT FROM AUTHOR]

Fire statistics provide valuable information for the assessment of future fire risks. The paper analyses the fire situation in China from 1991 to 2010. The temporal, spatial, and causal fire incident data for the last 6 years have been analyzed to gain an understanding of fire characteristics and the elements affecting fire risks. It is found that the number of fires was observed to be higher during cold winter months, and fires were more frequent during the weekend. The number of fires was lower during nighttime, whereas the number of fire deaths between midnight and 4 a.m. was much higher than at other times of the day. Most fire incidents occurred in residential buildings. In economically developed East China, the fire situation is much more serious. Electrical failures and improperly fire use in daily life were major causes of fire incidents. Based on the statistical data from China's fire services and the China Statistical Yearbook, the risk of occupant deaths and the risk of direct property loss are calculated to express the risk level in residential buildings. It is found that the risk of occupant deaths had a declining trend over the years. Statistics is considered a useful tool for learning from the actual events, and it helps decision makers develop proactive fire protection measures to reduce fatalities and financial losses caused by fires. [ABSTRACT FROM AUTHOR]

In this study, the effects of the possibility, time, and type of short circuits on energized residential electrical cables exposed to various radiant heat fluxes were investigated. Ten heat fluxes in the range of 21–30 kW/m2 were used on the surfaces of cables to irradiate them at 220 VAC using a standard cone heater, as is widely used in China. Breakdown was likely to occur on a cable heated at as low as 22 kW/m2. Electrical failure inevitably occurred at over 26 kW/m2. When the heat flux increased to 30 kW/m2, the maximum and average time required for breakdown decreased to 218 and 175.9 s, respectively. Below 26 kW/m2, the probability of a physical short occurring was higher than that of an arcing short with more than one arc, which had greater ignitability. In contrast, this trend reversed above 26 kW/m2. The arc number and duration of arcing shorts on cables exposed to heat flux below 26 kW/m2 were less than that on cables exposed to heat fluxes over this value. In most cases, the increasing duration of an arcing short could lead to more arc beads. Consequently, with an increase in heat flux, common cables could generate an arcing short with more arc beads in less time. [ABSTRACT FROM AUTHOR]

This paper studies the statistical law of fire attendance time and analyzes the correlation between fire attendance time and burned area based on the urban fire statistical data of Japan from 1995 to 2003 and in Jiangxi Province (China) from 2000 to 2010. The frequency of fire attendance time was better modeled by a lognormal distribution, and the probability density function for both Japan and China were formulated. The expectation of the lognormal distribution reflects the average level of fire attendance time. This study is the first to report that the distribution law of the burned area in each fire attendance time observes power function. And they are valid within 12 min of fire attendance time. The larger absolute value of the exponent of the power law function subjects to the larger probability of small-scale fire and the smaller probability of large-scale fire. It decreases as the fire attendance time increases. This indicates that the fire control ability becomes poor with longer fire attendance time. [ABSTRACT FROM AUTHOR]

To better understand the movement characteristics of pedestrians on long stairs, a series of individual evacuation experiments on a 12-level staircase were conducted in a public-access building in China. The factors including movement direction, walking preference, stepping pattern and light conditions were considered in the experiments. Pedestrians' space–time features, individual movement speed, blood pressure (BP) before and after experiments, and the change dynamics of heart rate (HR) during experiments were mainly analyzed and discussed. The mean individual upward speed with double-step pattern and single-step pattern was 0.92 m/s and 0.66 m/s, respectively. The mean individual downward speed with double-step pattern and single-step pattern was 1.01 m/s and 0.82 m/s, respectively. Only systolic BP appeared a significant increase in case of stair-ascending, from 107.26 to 115.02 under the condition of daytime and from 108.39 to 115.64 under the condition of nighttime. The results of HR experienced a sharp increase at the early stage (first around 100 s for stair-ascending and first about 40 s for stair-descending), and then maintained in a very small fluctuation range. The findings in this study can be adopted as input parameters in the evacuation models involving long staircase evacuation. The physiological results (i.e., BP and HR) can be used to evaluate the effort intensity of pedestrians when moving on long stairs. [ABSTRACT FROM AUTHOR]

The use of perfluorinated hexanone as a fire extinguishing agent for lithium-ion batteries (LIBs) has been steadily increasing in China in recent years. It successfully handles the fire extinguishing problem of LIBs, however, it can additionally set off steel aluminum corrosion. Due to a variety of factors, this could result in secondary disasters following the storage or use of perfluorinated hexanone. To better understand the mechanism of perfluorinated hexanone corrosion on aluminum and the structure of the product, we investigated the molecular structure of the corrosion product ('aluminum powder') using a variety of chemical analytical methods and hypothesized the mechanism of occurrence. This will aid in the regulation of perfluorinated hexanone safety and the avoidance of secondary disasters. [ABSTRACT FROM AUTHOR]

With the increasing development of underwater equipment, electrical fire has become the focus of safety concern. To effectively guide the fire engineering design and incident management, this research proposes a priority assessment method for the electrical fire risks in typical Chinese underwater equipment cabins, which integrates the fault tree, modified analytic hierarchy process (MAHP), B-RISK fire zone model and Borda number ranking. Firstly, the method uses the fault tree to identify the fire sources (origins) and MAHP involving the numbers of accidents and regulations and the failure rate to quantify the fire occurrence possibility. Secondly, the B-RISK model is used to predict and rank the fire severities induced by fire spread. Finally, a priority ranking of fire risk is achieved using the Borda number combining fire occurrence possibility and fire severity. The case study on a typical underwater power station show that the fire occurrence possibility obtained by MAHP is highly consistent with the result of traditional AHP. The B-RISK simulations can identify the fire spread paths and thus the causes of fire expansion. The rankings of fire occurrence possibility and fire severity do not consistent with each other therefore the Borda number can better evaluate the priority of fire risks which builds the foundations for potential fire engineering assessment and design. [ABSTRACT FROM AUTHOR]

A cross-region transfer learning method is proposed to identify community (e.g. car parks, public spaces and shopping centers) fire hazards based on text input provided by community members. The key component of the method, which also accounts for data imbalance, is an improved transfer component analysis that is embedded with a local discriminant analysis to transfer non-local rich knowledge to the fire hazard identification of local communities with an insufficient number of samples. In addition, a fire hazard knowledge map is established and applied to supplement the missing key features for fire hazard identification, and ontology modeling is applied to standardize the text features and reduce the effect of semantic ambiguity brought by cross-region knowledge transfer. The proposed method is verified based on the text data of nine fire hazard classes from Lanzhou and Beidaihe in China. Machine learning experiments show that fire hazard identification performance of all nine classes were improved with the overall accuracy, precision, recall, F1 score and AUC increased by 12%, 15%, 16%, 15% and 15%, respectively. Under data imbalance scenarios, the proposed method outperforms the state of the art methods, such as sampling-based methods, FastText and ULMFiT. The results also show that the proposed method can achieve desired performance with only half of the training samples. These findings illustrate that the proposed method can assist regions by improving fire identification results significantly through knowledge transfer. The proposed approach can be followed to build smart systems for community fire risk management with reasonable performance and high efficiency. [ABSTRACT FROM AUTHOR]

The enriched oxygen ambient may be applied to China's next generation space station. To understand the fire behaviors under oxygen-enriched microgravity environment, flame-spread experiments on extruded poly(methyl)methacrylate (PMMA) rods with 10-mm diameter were conducted in the SJ-10 Satellite. The opposed flame-spread behaviors were studied at the oxygen-enriched ambient (33.5% and 49.4%) under low flow velocities in the range of 0 to 12 cm/s. After the ignition in the middle of the sample, an opposed flame spread was achieved, rather than the forward flame spread. The flame-spread rate increases with the opposed flow velocity, due to the decreased flame width and the enhanced flame heat flux. Moreover, a blue flame sheet with a frequent burst of bubbles is found throughout the opposed-flow spread process, showing a near extinction behavior. For the oxygen concentration above 25%, normal-gravity experiments suggest that whether PMMA is cast or extruded should have a negligible effect on the opposed flame spread in microgravity. Compared to normal gravity, the microgravity flame spread rate in the oxygen-enriched atmosphere is slower which is the order of 0.1 mm/s, only one-tenth to one-fifth of that in normal gravity at the same nominal opposed flow velocity, and the acceleration of flame spread in microgravity by increasing oxygen concentration is also much smaller. This result suggests that (1) if the environmental gas flow is small, the fire hazard increased by raising oxygen level in microgravity space cabin can be much smaller than that on Earth; and (2) the fire risk of oxygen-enriched microgravity environment might be overestimated when a ground-based test method is employed to evaluate the burning characteristics of solid material. [ABSTRACT FROM AUTHOR]

Besides combustion behavior under normal atmosphere, combustion behavior under special environment is also an important aspect for safety operation of China high-speed train. The commercial flame-retardant natural rubber employed in China high-speed train as the main floor cloth material was investigated in this study at low oxygen atmosphere with 18 kW m−2 to 60 kW m−2 external heat fluxes by means of ASTM E2058 fire propagation apparatus to deepen the knowledge of combustion behavior. The ignition time of sample mainly depended on external heat flux not the oxygen concentration (only low and normal oxygen concentration) except 40 kW m−2. During the whole combustion process two main stages appeared, one was thermal decomposition of sample, and the other stage was the forming charry layer combustion. The CO and CO2 yields decreased with external heat flux increasing and the ratio of yCO/yCO2 firstly increased and then decreased. The experimental data in this study can provide guidance for fire safety design and assessment of China high-speed train. [ABSTRACT FROM AUTHOR]

Focusing on the high casualty fires (HCFs), an analytic network process (ANP) approach was proposed for rapid loss assessment. The networks of situation index (SI) and consequence index (CI) were built. A dataset of 469 HCF cases in China from 2002 to 2010 was established. The relative weights of all attributes and the values of CI and SI were calculated and analyzed. The results show that the casualty factors should be emphasized in loss assessment by CI. The elements of day, hospital, and smoking are most likely to cause huge loss for the attributes of time, place, and cause in the SI network, respectively. The correct classification rates of accident level were compared between ANP, multinomial logistic regression, multi-layer perceptron network, and radial basis function network. It is indicated that ANP performs best for HCFs of the high and extreme level or when the influence of accident level is considered. The relationship between CI and SI for HCFs of the high and extreme level was obtained by the weighted least square based polynomial fitting and can be used to generate meaningful results of extreme possibility for decision making. [ABSTRACT FROM AUTHOR]