浅谈边墙型扩展覆盖闭式喷头的应用

通过一个工程实例．对边墙型扩展覆盖喷头在喷头的布置、喷头强度计算方面进行了比较，提出在火灾危险级为轻危险和中危险Ⅰ级且不设吊顸的建筑物中，当房间进深尺寸超过单排边墙型标准啧头的保护跨度时，采用边墙型扩展覆盖喷头的优点及设计注意事项。     

浅谈边墙型喷头在医院、宾馆中的设计

在医院、宾馆等轻、中Ⅰ危险级建筑设置自动喷水系统,病房与客房不吊顶区域采用边墙型喷头,探讨边墙型喷头的布置与自动喷水系统水量的计算。     

浅谈自动喷水灭火系统的设计、应用

1 喷头选型与合理布置喷头的合理选型和布置关系着自动喷水灭火系统能否正常发挥作用,根据建筑物的不同功能部位应选择不同温度级的喷头。如:一般写字楼、公共用房、地下停车库等宜选用68℃温度级的喷头:厨房等高温场所宜采用93℃温度级;锅炉房等高温操作场所宜采用102℃温度级喷头。喷头温度级系指喷头实际的间距作了规定限值,有设计者误把此规定值当作布置应采用间距,不管被保护对象及建设平面尺寸和构造要求如何,一律采用3.6 m(中危险级)或4.2 m(轻危险级) 间距布置,结果出现喷头贴梁、贴柱安装,或者在不规则建筑平面上喷头布置凌乱,配管纵横交错、杂乱无章     

建筑自喷系统使用扩展覆盖边墙型喷头的探讨

针对轻危险级和危险级中 级建筑内居室上空为平顶板的场合,提出了使用扩展覆盖面边墙型EC喷头代替普通水平边墙型喷头的见解并就相关技术问题展开了讨论     

高层酒店客房中喷头布置的优化探讨

以某个高层酒店客房内喷头的布置为例,分析不同流量系数的边墙型喷头在此类酒店客房内的布置情况,比选出较佳方案,并提出相关设计建议。     

物流仓库自动喷水灭火系统设计实例

以某大型物流仓库为例,分析了自动喷水灭火系统的危险等级与设计参数,介绍了管网的主要布置形式,并从系统选型、管路布置、喷头布置等方面,阐述了自动喷水灭火系统的设计方法,使整个消防系统更加经济、合理、可靠。     

地下停车库喷头布置探讨

实际工程中,仍有少数设计在布置地下车库的喷头时,采用均匀布置喷头的方式,大部分喷头离结构梁的间距太近,导致施工时大面积设置集热罩结合下垂式喷头安装。该文指出了这种做法的不可取之处,分析了在进行无吊顶地下车库的喷头布置时需考虑的影响因素,并结合几种常见的梁板结构形式提出了喷头的具体布置方式,同时精确核算了系统的设计流量。     

再论自喷系统设计计算

该文阐述了喷头布置应按喷水强度通过计算确定,并指出中危险级自喷系统设计计算的两种方法中,长方形作用面积法更符合实际火灾情况。     

大力出喷头

美国 Gem喷淋公司开发出新的 K- 2 5EC直立型大出力喷头 (Big Box Sprinklers)。它可解决高喷水密度的消防保护需要。设计满足了严重危险级和高堆垛贮藏场所的灭火需求。K- 2 5大出力喷头通过了遮挡结构条件下的灭火试验 ,其申报专利的直立导流板设计可以有效地扩大喷水的最大覆盖面积大力出喷头$华东建筑设计研究院有限公司@杨琦     

自动喷水灭火系统设计技术探讨

自动喷水灭火系统在国内从７０年代初开始大量设计和实际应用,但目前仍有不少问题值得研究和探讨。１喷头选型与合理布置喷头的合理选型和布置关系着自动喷水灭火系统能否正常发挥作用,根据建筑物的不同功能部位应选择不同温度级的喷头。如：一般写字楼、公共用房、地下...     

地下公交站火灾烟气运动数值模拟

阐述地下公交站的现状及火灾危险性。利用FDS软件对不同喷淋和排烟设置下的烟气运动进行模拟,分析烟气运动规律及喷淋和排烟在烟气控制方面的作用。结果表明:靠近外墙体的监测点较之远离外墙体的监测点温度上升更快,能见度下降也更快;能见度通常领先其他火灾参数到达危险状态;喷淋系统在控制烟气蔓延上具有显著作用;喷淋失效时,单凭排烟量不足以阻挡烟气下降。     

某高架仓库火灾风险数值模拟

利用FDS对某高架仓库火灾风险进行数值模拟,并分析快速响应早期抑制喷头的控火效果,探讨机械排烟形成的负压对火灾蔓延的影响。结果表明,运用快速响应早期抑制喷头可以有效地防止火灾蔓延,而布置货架喷头可以进一步提高仓库的安全性;布置货架喷头时,货架内喷头的动作温度应比顶板喷头动作温度低;加入机械排烟时必须合理计算机械排烟量,避免负压引起新鲜空气进入火场。     

Spatially-resolved spray measurements and their implications

Fire sprinkler manufacturers have developed a great variety of application specific sprinkler designs. Advances in product development practices, performance based design, risk analysis, and fire suppression research have increased stakeholder interest in quantifying the spray produced by these devices. These sprinkler spray patterns consist of complex spatio-stochastic features originating near the sprinkler head. A Spatially-resolved Spray Scanning System (4S) has been developed to capture the complete spatio-stochastic nature of the spray at its point of origin for documentation and analysis. The 4S synthesizes spray measurements, transport analysis, and statistical representation frameworks providing high-fidelity spray characteristics suitable for evaluation of component-level performance (e.g. sprinkler spray pattern uniformity) or system-level performance (e.g. fire suppression system simulations). Each sprinkler's unique spray pattern is captured through optical and mechanical probing of the spray over a measurement (or initialization) surface close to the sprinkler head (0.4−0.8 m) and analyzing local drop characteristics (e.g. drop size, velocity, and volume flux). These high-fidelity 4S spray measurements consisting of terabyte scale data densities present remarkable challenges with regard to data management, test repeatability, and test timing. These challenges are addressed through integration of automation, flow control, data acquisition, and data analysis systems. Spatially-resolved sprinkler spray measurements are presented providing insight into the sprinkler spray patterns and their connection with deflector geometry. Comparisons between far-field spray dispersion measurements and simulations initialized with 4S measurements demonstrate unprecedented agreement further highlighting the value of spatially-resolved sprinkler measurements for modern suppression analysis.     

水喷淋控制下小室火灾的数值模拟研究

研究了水喷淋控制下对小室火灾发展过程的影响，结合一安装有水喷淋的实体小室，采用数值模拟方法进行了初步分析，设计了没有喷淋、0．1MPa喷淋控制和0．2MPa喷淋控制等三种工况。结果表明，水喷淋的启动，虽然可以控制火灾的发展，降低小室内的烟气温度，但也会增加烟气的生成量，使溢出的烟气增加。同时，水喷淋的压力增加，小室内的烟气温度继续下降，CO、炭黑以及水蒸气的生成量也会随之增加。这些都对大空间的人员安全疏散以及大空间整体的消防安全带来很大的影响。     

自动喷水灭火系统喷头最大间距辨析

设计规范中的喷头最大布置间距未和喷头类型相联系，每一危险级别均有两种及以上的喷头可选用，最大间距值应随喷头类型而调整。对一些常用喷头若采用该间距值会产生喷水强度不足的问题，提出最大间距应和喷头类型相联系。     

Assessing the Sprinkler Activation Predictive Capability of the BRANZFIRE Fire Model

This paper describes an investigation into the sprinkler response time predictive capability of the BRANZFIRE fire model. A set of 22 fire/sprinkler experiments are simulated where the sprinkler activation time and the heat release rate (HRR) for each individual experiment had been determined. The experiments provided data for use in validating the sprinkler activation prediction algorithms in the BRANZFIRE zone model. A set of base case values were chosen and input files constructed for the simulations. The experiments were then simulated by the fire model using both the NIST/JET ceiling jet and Alpert’s ceiling jet options (which are the two ceiling jet correlations available in the BRANZFIRE zone model). The fire model included a heat transfer calculation for the temperature of the heat sensitive sprinkler element. Different sprinkler operational parameters such as the conduction factor, response time index (RTI) and the sprinkler depth below ceiling were also varied to assess the sensitivity of their effect on the activation time. Results showed that using the NIST/JET ceiling jet algorithm gave a closer prediction of the sprinkler response time in a small room than Alpert’s correlation. This was expected, since the former includes the effect of a hot upper layer while the latter applies to unconfined ceilings. The experiments available for comparison had been conducted inside an enclosure with a developing hot upper layer. The findings also signified that changing the sprinkler operational parameters can change the predicted sprinkler activation time significantly.     

A fire risk analysis model for assessing options for flammable and combustible liquid products in storage and retail occupancies

A fire risk analysis modeling framework was developed to analyze options for fire-safe handling and storing of flammable and combustible liquids in containers. The model illustrates the application of general risk analysis modeling principles to a current, highly visible problem and introduces some new modeling elements. Risk is driven by relative success in providing a complete, operational sprinkler system adequate for controlling fires that start in ordinary combustibles, well away from the liquid products.     

Limited-water-supply sprinklers for manufactured (mobile) homes

A prototype limited-water-supply (LWS) sprinkler has been developed for manufactured (mobile) homes in a research program sponsored by the United States Fire Administration. The LWS sprinkler is designed to be installed at a 2.44 m (8-foot) spacing and to have a total water supply of 380 (100 gallons). The installation spacing was determined in a series of freeburn fire tests that indicated that the heat release rate at sprinkler actuation could be halved by reducing the sprinkler spacing from 3.66 m to 2.44 m (12 feet to 8 feet). A series of eight fullscale fire tests, including a corner living room scenario similar to that used in the Los Angeles Residential Test Program, was conducted to evaluate the performance of the prototype sprinkler. In five of the tests, room tenability was maintained during the 10-minute period following the actuation of a single sprinkler at a flow rate of 38 pm (10 gpm). In three tests, tenability was maintained with multiple sprinkler actuation (2 or 3 sprinklers) and a total system flow rate of 49 pm (13 gpm). The spray of the sprinkler was characterized in terms of its water flux distribution and drop size distribution. The thermal sensitivity requirements of the sprinkler are to be based upon RTI, C, and temperature rating, which would ensure that sprinkler actuation would occur at fire sizes comparable to those encountered using the prototype LWS sprinkler in this study.     

辐射热启动喷头的研究

为解决传统闭式洒水喷头安装的局限性,分析了传统闭式洒水喷头的吸热方式,揭示了传统闭式洒水喷头不能有效吸收辐射热的原因。根据辐射热的基本原理,提出了提高喷头感温元件吸收辐射热的方法并设计研发了辐射热启动喷头。为验证辐射热启动喷头的启动优势,进行了辐射热源和油盘火试验,对辐射热启动喷头和传统闭式洒水喷头的启动性能进行了对比研究。结果表明,在无法与热烟气进行对流换热的情况下,辐射热启动喷头能够通过吸收辐射热而启动。分析总结了影响喷头启动速度的因素以及在实际火灾条件下,辐射热启动喷头的热交换情况。     

汽机房自动喷水灭火系统中集热挡水板的应用探讨

基于集热挡水板在常规岛汽机房自动喷水灭火系统中的应用现状，结合《自动喷水灭火系统设计规范》和相关文献，分析自动喷水灭火系统中设置集热挡水板的合理性。指出通过设置集热挡水板来增大喷头溅水盘距顶板间距的不足之处，通过与优化喷头布置方式的对比分析，对汽机房内自动喷水灭火系统的喷头布置给出了建议。