Performance of selected coatings applied to polystyrene block walls under simulated mine fire conditions

A test program was undertaken by the Mine Safety and Health Administration (MSHA) to determine the feasibility of coating polystyrene block walls for fire protection. Selected coatings, used in the mining industry, were tested under semilarge scale, simulated mine fire conditions to determine the appropriate thicknesses of these coatings for protection of the polystyrene foam block against fire for specified time periods. Building plasters containing gypsum and perlite and an expanded vermiculite, portland cement, and limestone coating were particularly effective in protecting the foam blocks against the heat of the simulated mine fire. Reference: Steven J. Luzik, Performance of Selected Coatings Applied to Polystyrene Block Walls Under Simulated Mine Fire Conditions,Fire Technology, Vol. 22, No. 4, November 1986, p. 311.     

轻质防火保护层铝合金构件升温计算简化

由于铝合金材料的密度和比热容与钢材相比差别较大,在ISO 834标准升温条件下,铝合金构件的升温过程与钢构件存在明显差异.为了得到有轻质保护层铝合金构件的升温计算简化公式,采用增量法计算了ISO 834标准升温下的轻质保护层铝合金构件升温曲线,并对数据进行非线性拟合分析,得到了有轻质保护层铝合金构件升温计算简化公式,进...     

不同保护方式下消防车臂架结构耐火性能

以举高喷射消防车末端臂架为研究对象,分析池火 作用下臂架结构在不同防火保护下的耐火性能。利用模拟大板法 测试涂料的耐火性能,选择防火涂料。搭建小型油池火试验装置, 对比分析无防火保护、水喷淋保护及防火涂料保护下臂架结构的 耐火性能。结果表明,防火涂料和水喷淋保护下臂架结构的耐火 性能均有显著提高,其中,水喷淋保护下臂架结构在油池火试验中 臂架顶部峰值温度达到最低,相比于无防火保护的臂架降低了 151.9 ℃。     

Clean Agent System Utilizing FM-200® and Automatic Sprinkler System

Data processing and telecommunication (telco) facilities are commonly protected against fire with a clean agent system, an automatic sprinkler system, or with both a clean agent and an automatic sprinkler system. The degree of protection provided by these systems is vastly different, as is the cost incurred in employing these systems.Comparison testing of a clean agent system utilizing FM-200® (HFC-227ea) and an automatic sprinkler system was performed in order to illustrate the differences in the protection provided by gaseous clean agent systems and automatic sprinkler systems. The tests were performed in a simulated data processing/telecommunications facility, and examined the performance of the suppression systems on a plastics fire located inside a metal electronic equipment cabinet.In the clean agent system test, the fire was detected while it was small in size and was extinguished 17 sec after system actuation. Damage to the simulated facility and its contents was limited solely to the dislodging of several ceiling tiles near the clean agent nozzle, and a slight scorching of the cabinet containing the fuel array. The facility could be re-occupied and all systems within the facility, other than those damaged inside the cabinet involved in the fire, would be functional immediately following the extinguishment of the fire. Cleanup of the facility would not be required prior to its use following the fire event, as no residues were produced during extinguishment.Under the identical fire scenario, the automatic sprinkler system actuated approximately three minutes later than the clean agent system, and the fire was not extinguished by sprinkler system. The sprinkler system did achieve its primary objective of containing the fire to the room of origin and managing the temperatures at the ceiling to prevent structural damage and/or collapse, as the suspended ceiling remained intact, and the fire did not spread beyond the cabinet that contained the fuel array. Damage to the simulated facility was much more extensive than that resulting from the clean agent system test. All ceiling tiles were discolored and the tiles around the sprinkler heads that activated were warped and sagging. The walls were discolored throughout the entire simulated facility and a dark ring of varying intensity and width was observed just below the level of the suspended ceiling. Paper items located within the simulated facility suffered extensive water damage, and the simulated facility floor was covered in water containing large amounts of soot. Immediate reoccupation of the facility and resumption of business would be impossible under these circumstances, as the fire and smoke damage experienced by the facility and its contents would require the replacement of the facility walls, ceiling, and floor, and would likely require the replacement of water-damaged electronic equipment.The test results are discussed in detail as are the implications of the results in the design of fire protection systems for data processing and telecommunication type facilities.     

钢结构耐火极限试验研究

文章介绍了钢结构耐火极限试验条件，对裸露钢结构耐火试验、耐火极限与Hp/A的关系进行了分析，对现有钢结构的几种防火保护措施和对应的试验结果比较，探索其它防火保护措施，指出现有防火保护技术存在的问题和需要进一步研究的内容。     

城市综合管廊电力舱火灾行为试验研究

为了研究综合管廊电力舱火灾发展规律,本文分析了电力电缆火灾危险性和起火原因,建造了100 m×3 m×3 m综合管廊模拟火灾试验平台,基于真实电力电缆剖面结构,设计了模拟电缆火源模型并开展了燃烧对比试验和火灾燃烧相似性分析,开展了电力舱在非通风和1 m/s风速下的火灾模拟试验,分析了模拟电缆完成多层立体燃烧的全过程,研究了火焰和烟气蔓延规律以及氧含量变化规律,提出了电力舱火灾发展的4个阶段,试验认为火灾发生后,及时关闭通风系统和防火门等开口有利于抑制火灾发展,电缆层间设置防火隔板可以延缓多层电缆形成大规模燃烧的时间,舱内起火应立即切断所有电力回路,避免引发连环火灾爆炸。     

城市水下公路隧道火灾时人员安全疏散

以长沙市某水下公路隧道为研究对象,介绍隧道火灾时人员安全疏散准则及影响因素.设定火灾场景和疏散场景,分别利用FDS 5.3.0和EVACNET4模拟各火灾场景下的烟气蔓延及人员疏散,得到各种火灾场景下隧道内的可用安全疏散时间曲线和必需安全疏散时间曲线,分析不同火灾场景下人员疏散的安全性.在消防设施正常工作的情况下隧道内人员能够安全疏散,应加强消防设施的日常维护.     

飞机维修库防火技术探讨

分析了飞机维修具有的火灾危险性,探讨引发飞机维修库火灾的原因。针对飞机维修库火灾特点,分析了飞机维修库灭火分区、灭火系统和报警系统,并在建成的某飞机维修库中,模拟飞机机翼下火灾,检验了防火技术。结果表明:火灾报警系统顺利报警,在泡沫-雨淋系统和泡沫炮联合作用下,约6min后扑灭火灾。     

铝合金板式节点网壳破坏性火灾试验

为研究铝合金板式节点网壳结构在火灾下的破坏模式,采用柴油油池火对一网壳缩尺模型进行了2次破坏性火灾试验。研究结果表明,当火源功率为2MW(对应原型火源功率为110MW)且置于地面位置燃烧时,铝合金网壳模型所产生的变形均在试验结束后恢复,且未观测到影响结构宏观承载性能的永久变形。为了模拟局部特大功率火灾场景,将同功率火源抬高1.35m再次试验,网壳模型在火源点燃后第528s时发生倒塌破坏。其中,破坏模式包括部件熔化、杆件断裂和弯扭失稳。由试验结果可知,大空间的不均匀温度场分布对结构承载有利,设计中可采用场模拟或经验式考虑水平温度梯度的有利影响。此外,采用PyroSim和FDS进行了试验模型的温度场分析,通过对比空气温度 时间曲线和烟气流动情况,验证了所建立的模型的可靠性。     

换流变压器消防设计研究

基于新型火灾探测技术、新型水系灭火剂的水喷雾和消防炮灭火技术,搭建换流变压器模拟试验平台,开展不同场景下的火灾探测及灭火试验研究。研究表明,对于换流变压器火灾,新型火灾探测器可快速响应,基于水系灭火剂的水喷雾及消防炮可快速扑灭并可高效降温。根据研究成果并结合项目实际情况,提出一套适用于换流变压器的消防设计方案。     

高分子水凝胶灭火剂扑救建筑火灾研究

为测试高分子水凝胶灭火剂扑救建筑火灾的灭火效果,以GB 17835-2008《水系灭火剂》中A类火灭火试验相关规定为参照,搭建木垛实验平台,模拟火灾荷载密度为2 395.008 MJ/m2（相当于一家服装店的火灾荷载）的建筑火灾,且在相同条件下,对比测试高分子水凝胶与水两种灭火剂的灭火效果,并利用车泵压、流量等相关关系计算得出高分子水凝胶灭火剂在建筑火灾扑救中的灭火强度。试验对比分析结果表明,高分子水凝胶灭火剂的灭火时间比水灭火剂的灭火时间短,其灭火效果优于水;同时依据相关计算得出高分子水凝胶灭火剂扑救建筑火灾的灭火强度约为0.059 L/（s.m2）。     

古建筑消防安全特性及防火对策研析

古建筑多为木质结构,并且年代久远,极易发生火灾,存在着特别重大的消防安全隐患。本文从古建筑的消防安全特性出发,探讨了如何运用现代的消防手段,并提出了新形势下古建筑防火对策和措施。     

Effects of partial fire protection on temperature developments in steel joints protected by intumescent coating

This paper presents experimental results of temperature distribution in fire in four typical types of steel–concrete composite joint (web cleat, fin plate, flush endplate and flexible endplate) with different fire-protection schemes. The test specimens were unloaded and the steelwork of each joint assembly was exposed to a standard fire condition [ISO 834, 1975: Fire Resistance Tests, Elements of Building Construction, International Organization for Standardization, Geneva] in a furnace. In total, 14 tests were conducted, including 4 tests without any fire protection and 10 tests with different schemes of fire protection. The main objective of these tests was to investigate the effects of three practical fire-protection schemes as alternatives to full fire protection of the entire joint assembly. The three alternative methods of fire protection were: (1) protecting a segment, instead of the entire length, of the beams; (2) unprotected bolts and (3) protecting the columns only. The main results of these tests are: (1) if all the steel work (excluding the bolts) in the joint assembly was protected, whether or not protecting the bolts had very little effect on temperatures in the protected steelwork other than the bolts. The bolt temperatures were higher if they were not protected than if they were protected, but the unprotected bolt temperatures in a joint with fire protection to other steelwork were much lower than bolt temperatures in a totally unprotected joint; (2) as far as joint temperatures are concerned, protecting a segment of 400 mm of the beam was sufficient to achieve full protection and (3) if only the column was protected, only the joint components that were in the immediate vicinity of the column (such as welds) developed noticeably lower temperatures than if the joint assembly was unprotected, but due to heat conduction from the unprotected steel beams, these temperature values were much higher than if the joint assembly was protected. Furthermore, the column temperatures in the joint region were much higher than the protected column temperatures.     

砖木或木结构古建筑的消防设计探讨

随着社会经济的发展和国家对文物保护工作的重视,砖木或木结构古建筑的消防安全越来越引起人们的关注,文章着重讨论此类古建筑消防设计的必要性、可行性和一些特殊的设计方法。     

Numerical analysis of aluminum alloy reticulated shells with gusset joints under fire conditions

In this study, a numerical analysis was conducted on aluminum alloy reticulated shells (AARSs) with gusset joints under fire conditions. First, a thermal-structural coupled analysis model of AARSs considering joint semi-rigidity was proposed and validated against room-temperature and fire tests. The proposed model can also be adopted to analyze the fire response of other reticulated structures with semi-rigid joints. Second, a parametric analysis was conducted based on the numerical model to explore the buckling behavior of K6 AARS with gusset joints under fire conditions. The results indicated that the span, height-to-span ratio, height of the supporting structure, and fire power influence the reduction factor of the buckling capacity of AARSs under fire conditions. In contrast, the reduction factor is independent of the number of element divisions, number of rings, span-to-thickness ratio, and support condition. Subsequently, practical design formulae for predicting the reduction factor of the buckling capacity of K6 AARSs were derived based on numerical analysis results and machine learning techniques to provide a rapid evaluation method. Finally, further numerical analyses were conducted to propose practical design suggestions, including the conditions of ignoring the ultimate bearing capacity analysis of K6 AARS and ignoring the radiative heat flux.     

现代钢结构抗火设计方法

文章论述了火灾对负结构的危害和钢结构抗火设计的目标与意义，基于高温承载力极限状态验算的思想，文章阐述了现代钢结构抗火计算与设计方法，并通过试验验证了这一方法的科学性、合理性与有效性。     

浅析大云寺消防工程设计

结合大云寺的概况,分析了大云寺的重要性,探讨了大云寺消防设施建设的必要性,提出了大云寺消防设计的原则和依据,详细介绍了该古建筑消防设施的设计,达到有效保护大云寺这组十分珍重的金、明、清古建筑群的目的.     

钢结构构件热响应的研究现状

钢材在高温下强度和刚度都将迅速降低，介绍了国内外关于钢结构构件在火灾中热响应的试验和计算机数值模拟的研究成果，并着重介绍了在无保护层、有保护层和截面温度非均匀分布三种情况下构件的热响应分析计算方法，提出了火灾中钢结构构件抗火设计今后需要研究的问题。