Zhirong Wang

Nanjing Tech University

The operation of mobile hydrogen refueling stations will be popular for hydrogen energy supply in the future, and the investigation includes the hydrogen diffusion behavior of hydrogen leakage and the potential risk of explosion is pivotal to commercializing the mobile hydrogen refueling station. The dispersion of hydrogen leakage and the minimum s...

Emergency response has an important impact on the mitigation of the domino effects. However, consequence analysis of the domino effect often ignores emergency response due to its complexity and uncertainty. In this paper, Fuzzy Analytic Hierarchy Process (FAHP) is adopted to evaluate the reliability of emergency response process. On this basis, usi...

The effect of wire mesh structure parameter on the flame propagation characteristics and intensity of syngas explosion was studied by the visual experiment. The corresponding relationship between the flame propagation and pressure rise of wire mesh two ends under the flame resistance success and failure conditions was analyzed by the comparison. Re...

A significant risk for lithium-ion batteries (LIBs) is fire and explosions caused by thermal runaway (TR). A TR model for LIBs with various states of charge (SOCs) can help design safer battery modules. In this work, the TR mechanism of a commercial Li[Ni5Co2Mn3]O2/graphite 18650 type cylindrical battery with various SOCs has been investigated thro...

Traditional transition metal sulfides (TMSs) have shown favorable potentials in energy storage. Nevertheless, its further usage is plagued by the issues of particle breakage and large volume change. In this work, the nanostructured ternary TMSs coupled with N/S doped carbon protector (NiCoFe-S@NSC) is delicately designed via compositional regulatio...

The current work performs a comprehensive investigation to determine the best blend between fluoroethylene carbonate and common carbonate solvents, that is, ethyl methyl carbonate (EMC), diethyl carbonate (DEC), and dimethyl carbonate (DMC), for high-voltage and high-safety lithium-ion cells. These three kinds of electrolytes denoted FEMC, FDEC, an...

A set of experimental equipment for quenching the deflagration flame in linked vessels with parallel narrow channels was proposed. The quenching effects of the deflagration flame in the linked vessels were investigated, the influence law and mechanism of parallel narrow channels on the deflagration flame was analyzed. The results showed that the Pm...

This work investigates the suppression effect of water mist containing dimethyl methylphosphonate (DMMP) on H2 jet flame. The flame appearances are analyzed and the flame temperature is recorded by a high-speed infrared camera. Results show that the suppression effect of water mist containing DMMP is better than that of pure water mist. To better u...

This experimental study focused on the inhibition of ultrafine water mist on methane/coal dust hybrid explosions inside the closed vessel. Combined with the change of explosion parameter (including the flame propagation characteristics, explosion pressure, pressure rising rate and flame temperature), the corresponding relationship between the flame...

The combustion of Lithium-ion battery (LIB) vent gases plays key roles in determining LIB fire hazard. Previous studies analyze the combustion of LIB vent gases without consideration of electrolyte. This work studies the combustion characteristic of LIB vent gases with dimethyl carbonate (DMC) addition. The flammability limit, laminar burning veloc...

Flame pulsation is a significant feature for both laminar and turbulent jet fires. In this study, the pulsation behaviors and the dominating mechanism of rectangular jet fires were explored. A series of experiments were conducted on the rectangular syngas jet fires with fuel flow rates ranging from 5 L/min to 45 L/min and aspect ratios ranging from...

Given that many safety standards for lithium-ion cells include a saltwater immersion test and the possibility of cell immersion by water by accident, this work prepares five kinds of cells by varying immersion time and saltwater concentration to explore the influence of saltwater immersion on the topographic, electrochemical and thermal characteris...

Aging and thermal runaway are two significant reasons why lithium-ion batteries are struggling to become more widely available. Aging at different temperatures causes differences in the aging mechanism and thermal runaway behaviour of lithium-ion batteries. In this paper, four sets of commercial lithium-ion batteries are aged at 25 °C, 40 °C, 60 °C...

The leakage and dispersion of hydrogen gas in a mobile hydrogen refueling station is being numerically investigated in this paper. The investigated geometry is derived from the mobile hydrogen refueling station in China. The numerical models are verified by experimental data. The hydrogen gas leaks from the hydrogen buffer tank in the form of momen...

Thermal runaway (TR) of lithium-ion batteries (LIBs) and its propagation in battery packs may bring significant losses and restrict the wide application of LIB. It is important to study the propagation characteristics of TR. Based on a series of experiments, this work analyses the influence of state of charge, environment temperature, and heating p...

Considering the prospect of lithium-ion cells with graphite + SiOx anode and the fact that there is rare literature concerning the safety features of graphite + SiOx based cells, this work performed an experimental investigation on the safety characteristics of Li(Ni0.8Mn0.1Co0.1)O2/(graphite+10%SiOx) cells with different states of charge (50% SOC,...

The pulsation frequency of inclined jet fire was systematically studied in this study. Experiments of syngas jet fire with a nozzle diameter of 15 mm at different fuel flow rates (2.5 L/min∼20 L/min) and inclination angles (0°∼90°) were conducted. The pulsation frequency of inclined jet flame is quantified by applying FFT to the time variations of...

Epoxy resin (EP) has been favored in extensive fields. Nevertheless, the notorious issue of high fire hazard has been a nonnegligible bottleneck for its extended application. Here, a Jadeite original stone inspired PBA core-shell architecture (Co–Fe–Co PBA) is constructed towards fire retardation and toxicity elimination of EP. This architecture ho...

Transition metals carbides/nitrides (MXenes) have been utilized as flame retardants for epoxy resin (EP) with inherently high fire hazard. However, when the dosage of MXenes is low, the corresponding flame retardant efficiency is hard to meet the demand. Up to now, MXenes-based nanostructure with high flame retardation effectiveness has been rarely...

The effects of initial conditions, structure parameters, and expansion chamber structures on the flame quenching performance of hydrogen crimped-ribbon flame arrester were experimentally studied based on the self-built experimental apparatus. The influence law of different working conditions on flame propagation velocity (Vf) and explosion pressure...

The progressively improving technologies and products have proposed higher requirements for energy storing devices with cheapness and sustainability. Hence, the rechargeable batteries of lithium ion batteries (LIBs) and sodium ion batteries (SIBs) have been preferred. Nevertheless, the extended usages of LIBs and SIBs are confronted with the dilemm...

A set of experimental equipment for suppression of methane/air deflagration-to-detonation transition (DDT) was proposed. In this investigation, a 113-L cylindrical vessel and a 6-m long linked pipe with a 100-mm internal diameter were used to investigate the suppression characteristics of methane/air deflagration-to-detonation transition (DDT) in a...

The thermal stability of overcharged lithium-ion batteries (LIBs) and heat contribution ratio of different components during thermal runaway are unclear. This paper investigates the thermal stability changes of the full battery and components after overcharging. The degradation mechanism of thermal stability induced by overcharging is revealed. The...

Thermal runaway (TR) propagation of lithium-ion batteries (LIBs) in air may cause fire, and argon can effectively inhibit LIBs with TR propagation. The oxygen concentration and gas flow rate are the important factors affecting the TR propagation. Hence, an experimental device for LIBs with TR propagation in air and argon environments in a confined...

Inherently high fire hazard has been the disreputable and nerve-wracking issue of epoxy resin (EP), challenging its extended applications. Hence, we have adopted the interfacial gluing strategy to acquire closely-coupled ternary [email protected] nanohybrid as flame retardant filler. When loading 2.0 wt% [email protected], peak heat release rate an...

Conventional carbonate‐based electrolytes can be oxidized at voltages above 4.3 V, causing serious cell degradation, and are highly flammable that easily induces safety hazards. In this research, a non‐combustible electrolyte for high‐voltage Li(Ni0.8Mn0.1Co0.1)O2 cathode Li‐ion cells is investigated, using propylene carbonate (PC) and 2,2,2‐triflu...

Transition-metal phosphides are desirable candidates for supercapacitors. Herein, bimetallic phosphides NiCoP/CC is obtained with 3D nano-micro structure. This unique as well as the altered electronic structure effectively improved the energy density of NiCoP/CC//AC hybrid supercapacitors (HSCs). As compared to Ni2P/CC, NiCoP/CC shows a metallic co...

Mixed-valence is an effective way to achieve high electrochemical performance of anodes for supercapacitor. However, inordinate mixed valence with more structural defects leads to structural instability. The development of mixed valence electrodes that can maintain a stable structure during the defect formation process is the key to resolving this...

Hydrogen is a clean fuel, however, the potential leakage and jet fire accidents should be considered seriously. This study focuses on the burning behaviors of horizontal hydrogen jet fires under the action of a water curtain system. The experiments of horizontal hydrogen jet fires with fuel flow rate ranging from 30 to 80 L/min and initial pressure...

The extended usage of epoxy resin (EP) has suffered from the notorious issue of high fire hazard, including the release of considerable heat and emission of abundant toxicants (smoke and toxic gases). Hence, a prussian blue analogue (PBA) based hierarchical structure ([email protected](OH)2-A) with Ni(OH)2 nanocatalyst, is proposed via interfacial-...

Transition metals carbides/nitrides (MXenes) have been a hot spot in constructing fire-safe polymer composites, benefiting from their unique 2D nanostructure and catalytic activity. Here, a ternary hierarchical nanoarchitecture of Cu2[email protected] is constructed, towards impairing the heat and toxic volatiles emissions of epoxy (EP) resin, thus...

This experimental study focused on effect of obstacle on the syngas (H2/CO) explosion characteristics under lean-fuel conditions. The relationship between the flame propagation characteristics and explosion intensity, and effects of syngas concentration, obstacle number and blocking rate on explosion parameters were obtained. Results indicate that...

Scanning electron microscope (SEM), energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD) were used to analyze the surface micromorphology and components of the iron oxide sulfide powders respectively. Differential scanning calorimetry (DSC) and thermogravimetry (TG) were used to investigate the self-heating properties. It was observed t...

It is well-recognized that, the inferior fire safety has been the stumbling block for the extensive usages of bismaleimide resin (BMI). Hence, a ternary hierarchical MXenes-based nanoarchitecture (CMAMX) is rationally engineered, towards suppressing the heat and toxicants emissions of BMI. By incorporating 2.0 wt% CMAMX, the marked reductions of 36...

The laminar flame speed of syngas (CO:H2 = 1:1)/air premixed gas in a wide equivalence ratio range (0.6–5) and initial temperature (298–423 K) was studied by Bunsen burner. The results show that the laminar flame speed first increases and then decreases as the equivalence ratio increasing, which is a maximum laminar flame speed at n = 2. The lamina...

Electrochemical-thermal models with different levels of fidelity and dimensionality are studied. • Non-uniformity of heat generation and electrochemical reaction of the battery is characterized. • The accuracy of the different Electrochemical-thermal models is determined. • The scope of applicability of different Electrochemical-thermal models is p...

The effects of connected vessels structure (pipe bending position and angle, vessel shape and volume) and bifurcated pipe on methane explosion characteristics were experimentally researched. Six explosion vessels with different volumes and shapes and a series of bending pipes were adopted respectively. Results indicate that the explosion pressure i...

The thermal buckling behaviors of oil-filled tanks subjected to heat radiation of a burning tank are investigated considering the effect of isopentane on the heat transfer. The effects of the height-to-diameter ratio, fluid level, and wall thickness on the thermal buckling behavior and fire resistance of oil-filled tanks are studied, and the failur...

The notorious issue of high fire hazard, including the generation of considerable heat and release of plentiful toxic volatiles, is recognized as the bottleneck of extensive use of epoxy resin (EP). Hence, a covalently functionalized hierarchical MnO2@LDH nanostructure (FA-MnO2@LDH) is rationally designed to alleviate these problems. With the incor...

Chitosan-bridged 2D/2D hierarchical nanostructure based on boron nitride (BN) and molybdenum disulfide (MoS2) nanosheets (CBN-Mo-B) is constructed, towards impairing the fire hazard of epoxy resin (EP). With the loading of 2.0 wt% CBN-Mo-B, the peak heat release rate and total heat release are reduced by 28.1% and 25.7%, with the decreases of 35.4%...

Overcharging occurs owing to the malfunction of charge control and inappropriate battery management system. Overcharging mechanisms, aging mechanisms, and the influence of aging on overcharging are studied in this work. The results indicate that normal charging, lithium plating, electrolyte oxidation and decomposition, excessive electrolyte decompo...

Pipeline leakages have plagued pipeline transportation for long time. Therefore, accurately extracting the features of leak signal in the presence of noise, and prompt identification of leak states and leak sizes is essential when leakage occurs. A novel leakage detection method based on the improved adaptive filter, whose parameters were optimized...

To investigate the effect of initial temperature, initial vessel pressure and the ratio of hydrogen in the syngas on the spontaneous ignition of high-pressure syngas release, a series of experiments was conducted. The influence law and mechanism of the spontaneous ignition was investigated. The experimental results showed that the pressure in the t...

Thermal runaway caused by overcharging results in catastrophic disasters. The influences of charging rate, ambient temperature and aging on thermal runaway caused by overcharging are studied qualitatively and quantitively in this manuscript. The results of overcharging tests indicate that high charging rate and ambient temperature increase thermal...

When lithium-ion batteries (LIBs) are subjected to thermal, electrical, or mechanical abuse during use or transport, thermal runaway may occur, which can result in fire and explosion. Fine water mist has attracted considerable attention as an efficient, environmentally friendly fire extinguishing medium. We used fine water mist containing a compoun...

This study experimentally and numerically determined the effect of FM-200 on H2/air explosion. Firstly, the explosion pressure was investigated to evaluate the suppression efficiency. The results indicated that the effect of FM-200 on H2/air explosion was quite different for various equivalence ratios. FM-200 could enhance the explosion at lean mix...

This experimental study focuses on the corrosion behavior of aluminum alloys in hydrogen sulfide (H2S) gas and liquid phases. The corrosion behaviors of 3A21, 6061, and 6063 aluminum alloys are investigated via scanning electron microscopy, energy dispersive spectroscopy, and thermogravimetry-differential scanning calorimetry. The results show that...

This paper investigated the effect of separation distance on the flame appearance and radiation heat flux of medium-scale pool fires dominated by radiation. A series of experiments were conducted on two adjacent heptane pool fires with diameters of 20 cm, 40 cm and 60 cm at separation distances ranging from 0 to 60 cm. According to experimental res...

To systematically and quantitatively establish a multi-factor evaluation method for the thermal runaway risk of lithium-ion batteries (LIBs), the fuzzy analytic hierarchy process was adopted in this paper. The own hazardous factor of battery, hazardous factor of vented gases, jet fire and high-temperature mixture (JFHM), ejected powder and their co...

The evolution success for heat recovery technology plays an important role in global sustainable energy solution. Low-grade heat (below 200℃) from solar radiation, industry, and the human body is usually...

Pyrolysis and autoignition of beech wood covered with an acrylic-based waterborne coating layer are experimentally and numerically examined. Thermogravimetric Analysis (TGA) tests were conducted first for wood and coating to derive the kinetic parameters combining a numerical model, Genetic Algorithm (GA) and Particle Swarm Optimization (PSO). Subs...

The emission of considerable smoke and toxic gases has been the notorious stumbling block on the extended usage of epoxy resin (EP), which often causes serious fire casualties in real fire. Hence, metal organic frameworks (MOFs)-derived self‐sacrificing template strategy is adopted, to prepare metal oxides double-shelled nanocages (Co3O4/Co3O4 and...

Building exit has always been an emphasis of research in the field of evacuation. Existing studies on crowd flow characteristics at building evacuation bottlenecks usually focus on plane exit, but insufficient attention has been paid to the characteristics of crowd flow at the convex exit. Convex exit can be considered as such a structure like a do...

A set of experimental equipment for wire mesh inhibition and ducted venting on methane explosions was proposed. The effects of wire mesh parameters, venting parameters, and initial conditions on the explosion intensity were also investigated and the interaction mechanism between the wire mesh inhibition and ducted venting was analysed. The results...

High fire hazard of generating a great deal of heat and toxic volatiles has been deemed as notorious issue of thermoplastic polyurethane (TPU), severely impeding its practical usage. Hence, a hierarchical ternary structure (FNPCN) based on NiAl LDH anchored phosphorus-doped g-C3N4 dotted with Fe3O4 nanoparticles is rationally designed as flame reta...

Owing to the corrosive, flammable, and explosive properties of pipeline materials in alkylation units, corrosion failure may result in leakage, fire, and explosion accidents. A bursting accident occurred in the 90° elbow of an alkylation unit pipeline. Failure analysis was performed by macroscopic analysis, metallographic analysis, chemical composi...

Due to the complex effects of combined loadings on complete steel structures, the combined effects of high-velocity projectile impact and heat radiation due to a pool-fire on a vertical Q345 steel tank have not been generally considered. In this study, a consecutive coupling approach is established. The combined effects of projectile perforation an...

Thermal runaway (TR) may propagate in a lithium-ion battery (LIB) pack in confined and semi-confined spaces, because of insufficient heat dissipation. This may induce accidents and lead to significant losses. However, the heat transfer modes between cells when TR propagates in an LIB pack have not been revealed. In this work, aluminium foil (AF), w...

The growing use of electric vehicles has made it imperative to use safe battery packs. Severe accidents may occur even due to minor faults in battery packs. One such issue is thermal runaway (TR) propagation in lithium-ion batteries (LIBs). In this study, cylindrical 18650 LIBs were employed to determine the factors responsible for TR propagation i...

Carbon dioxide is a common gas in the chemical industry, and it is asphyxiating. A test system was established to determine the characteristics of indoor gas diffusion. The system comprised an enclosed space, gas discharge system, data acquisition system, and obstacle. CO2 gas concentration due to an indoor leak was measured, and characteristics of...

To understand the overpressure transient and flame behavior of CH4/air premixed gas explosion venting in the presence of porous materials, a series of explosion venting tests is conducted in a spherical vessel with a neck. The effects of pore size, porosity, thickness, and properties of porous material on Pstat, Pred, Pburst, and Pext are measured...

In dense crowd evacuation, especially in emergencies such as fires, the safe evacuation of large public facilities will face major challenges. At the same time, as cluster congestion tends to occur in the space where the flow rate drops sharply, the superposition of fire incidents and bottleneck areas can easily evolve into malignant disasters and...

To study the occurrence conditions and propagation characteristics of deflagration to detonation transition (DDT) in linked vessels, two typical linked vessels were investigated in this study. The DDT of the methane–air mixture under different pipe lengths and inner diameters was studied. Results showed that the CJ detonation pressure of the methan...

The gas explosion parameters are affected by the structural parameters. Therefore, the paper numerically studied the gas explosion in cylinder to quantify the dependency of gas explosion parameters on the structural parameters. The results show that both the volume and length-diameter ratio of the cylindrical container affected the methane explosio...

With increasing attention to energy efficiency and environmental protection, syngas has attracted great interest as a clean fuel with broad development prospects. In order to further study the effect of the initial gas flow on the explosion of syngas, an explosion experiment of stoichiometric syngas/air premixed gas was carried out in a 3 × 3 × 100...

As an important industrial raw material, syngas can be used for hydrogen production, and its main components include hydrogen and carbon monoxide. Experiments were conducted on syngas (ratio of CO and H2 is 1:1) to study the effects of the nozzle inclined angle and diameter as well as the heat release rate on the characteristics of syngas jet flame...

Chemical industry park plays an important role in optimizing the allocation of resources, but an emergency may make a great deal of personnel casualty and property loss. Many casualties are not the result of accidents but are caused by extreme behavior because of the non-adaptive psychology of the evacuees. Panic is one of the non-adaptive psycholo...

Chained explosions happened occasionally, leading to heavy casualties and huge property losses. However, the development regime of the chained explosions is unclear. Experiments of both single and two vertically distributed vapor clouds with different sizes, volume concentrations and ignition conditions were conducted. The experimental results show...

This numerical study focused on the heat transfer process between the ultrafine water mist and explosion flame, and the suppression mechanism of ultrafine water mist and the effect of mist parameter on methane explosion. Hence, a three-dimensional numerical model for methane explosion suppression by ultrafine water mist was established. Large eddy...

Explosion venting is widely applied in industrial explosion-proof designs due to the convenient, economical and practical features of this method. Natural gas is usually stored in storage tanks. If the gas in the vessel is mixed with air and encounters an ignition source, explosion venting might occur, producing jet fire, generating new secondary d...

The inhibition effect of heptafluoropropane (CF3CHFCF3) on methane explosions under different inhibitor concentrations in a closed vessel was studied. A high-speed camera and a pressure sensor were adopted respectively to record flame propagation characteristics and pressure data. Results indicate that the relationship between flame propagation and...

With the development of modern automatic control systems, chemical accidents are of low frequency in most chemical plants, but once an accident happens, it often causes serious consequences. Near-misses are the precursor of accidents. As the process progresses, near misses caused by abnormal fluctuation of process variables may eventually lead to a...

Petrochemical plants are continuously turning into large-size corporations, the installations of facilities show a developing trend from ground to underground because of the difference in land using rate. In this regard, the safety distance of petrochemical equipment buried in both ground and underground cases were investigated based on risk assess...

This contribution experimentally addresses the auto-ignition of finite thick PMMA (polymethyl methacrylate) subjected to parallel forced convective airflow. 1–15 mm thick samples, 30–60 kW/m² heat fluxes (HF) and 0–1.2 m/s airflow velocities (u) were utilized to examine the auto-ignition mechanism and the limiting condition of non-ignition cases. C...

A concentration test device was set up to study and analyze the thermal runaway gas production process in lithium-ion batteries. The experimental conditions for the research were determined by the influence of different external environments and gas flow rates on the thermal runaway process. Gas measurement and analysis of CO and CO2 generated in t...

order to study the characteristics and rules of deflagration to detonation transition (DDT) in linked vessels, two typical linked vessels were selected in this paper. The research was focused on the effects of pipe length, obstacle number, obstacle position and obstacle blockage ratio on DDT of methane air mixture in linked vessels. The experimenta...

As flanged pipes have a crucial role in oil and gas transportation, accidental leaks and their detection are of great importance, and represent a great concern in safety management of pipes. The present study develops an integrated approach, based on acoustic emission (AE) signals, in order to detect and locate leaks in flanged pipes. It is depicte...

In this study, the mild steel corrosion inhibition performance and the corresponding mechanisms of five imidazolium-based ionic liquids (ILs) in hydrogen sulfide (H2S) and hydrochloric acid (HCl) solutions were investigated using electrochemical experiments, weight loss measurement, morphology analysis, and quantum chemical calculation. The results...

The corrosive environment in sulfur-containing equipment is often complicated and changeable. This study adopted the Taguchi method to optimize the immersion test, and the L27(3¹³) orthogonal table was used to design an immersion corrosion experiment. The influence of four factors, namely, the total acid number (TAN), sulfur, chlorine, and water, o...

In this study, four imidazolium‐based ionic liquids (ILs) were selected to investigate the inhibiting effect of ILs with various alkyl chain lengths on the corrosion of mild steel in H2S and HCl solution using electrochemical experiments, weight loss experiment, surface analysis, and quantum chemical study. The results showed that these ILs acted a...

The metro has become an important component of the urban traffic system. Due to the dense crowd, if sudden accidents occurred during rush hours in station, such as fires, explosions or natural disasters, the casualty and injury would be very enormous. Accidents happening in the underground station are prone to trigger domino effect, causing complex...

This contribution experimentally and numerically investigates the thermal decomposition of phenol formaldehyde (PF) through thermogravimetric method coupling a new hybrid pyrolysis mechanism. Complicated pyrolysis process associated with at least 6 reactions was observed and a Gauss multi-peak fitting method was applied to identify the contribution...