Research on Assessment Method of Fire Protection System

Transcription

1 Avalable onlne at Proceda Engneerng 11 (2011) The 5 th onference on Performance-based Fre and Fre Protecton Engneerng Research on Assessment Method of Fre Protecton System HUANG Yan-bo a,*, HAN Bng a, ZHAO Zhe b a Guangdong Technology enter of Work Safety, Guangzhou, ,hna b Safety Engneerng Research enter, Department of Engneerng, Sun Yat-sen Unversty Guangzhou, ,hna Abstract Safety assessment of fre protecton (SAFP) s a very mportant approach n fre safety management. Effectveness and relablty are crucal to the SAFP, whch has endowed the study of the assessment methods sgnfcant meanng. A new quanttatve method named theoretcal safety control method, based on modern control theory, was studed n the paper. Dynamc models, assessment ndexes and analyss approaches of every ndex of the SAFP were put forward and three dynamc ndexes, that are System Hazard Index-H, ontrol apacty Index- and Safety Degree-S whch changed wth the system states and presented the conflctng consequence between hazards and controllng of fre protecton system, were used to evaluate the results of the method. Ths method can realze dynamc and quanttatve management and the fre protecton system controllng. A case study was defned and assessed by usng the method n ths paper, and the results of evaluaton were vable compared wth the actual stuaton. 2011Publshed by Elsever Ltd. Open access under BY-N-ND lcense. Keywords: Safety Assessment of Fre Protecton System, Safety ontrol Theory, Safety ndexes 1. Introducton Fre s one of the most frequent dsasters whch had been happened tmes from 1950 to 1998 accordng to hnese Statstc Yearbook of Fre (Edton 1999). There were persons ded, njured and mllon Yuan drectly lost n those fres. Table1 s the basc data of fre statstcs n hna from 2000 to Table1 The basc data of fre statstcs n hna from 2000 to Year Fre number Death Injury Drect loss Ten Thousand Yuan ,185 3,021 4,404 20, ,929 3,752 2,314 93,659.1 * orrespondng author. Tel.: ; fax: E-mal address: huangyan197365@163.com Publshed by Elsever Ltd. do: /j.proeng Open access under BY-N-ND lcense.

2 148 HUANG Yan-bo et al. / Proceda Engneerng 11 (2011) ,315 3,414 2, , ,932 2,482 3, , ,704 2,558 2, , ,941 2,500 2, , ,702 1,517 1,418 78, ,000 1, ,000.0 Note: The fre-related statstcs data over the years quoted from hnese Statstc Yearbook of Fre Table1 shows that the numbers of fre were large and the losses were serous. So, t s of great sgnfcance to reduce the occurrence rate of fre accdents and mprove fre safety management by the development of fre scence, fre safety technology and management methods. As for hna, the management method must be ft for the current economc development and socal needs. SAFP s a very mportant approach n fre safety management. Its theory and method s an mportant part of fre scence and a scentfc base of fre preventon wth effectveness, ratonalty and economy. Nomenclature A,B, Detecton grade A t The total areas A Matrx S(k) The safety degree B(k) The control effect of annual k The annual ontrol capacty coeffcent of rsk onstants H The hazard coeffcent H p The personal densty ndex n buldng w The weght γ The correcton ndex M v The weght of one combustble matter h c The effectve heat value of one combustble matter

3 HUANG Yan-bo et al. / Proceda Engneerng 11 (2011) The assessment theory and ndexes of the fre fghtng system Fre safety assessment began to be studed n many countres from the early of 1970s. Some developed countres such as England, Japan, Australa, Amerca, anada, New Zealand, North Europe and etc, have been nvested a lot of money n t, major n performance-based fre desgn. Performance-based fre desgn, based on the fre safety engneerng, uses the fre safety engneerng prncple and method to forecast and quanttatvely evaluate the rsks of fre and the damages of buldngs accordng to the specfc crcumstances such as the buldng structure, purpose, nner nflammable matters. As a result, a ratonal fre safety plannng can be obtaned and the buldngs can be protected relably. Researches of fre safety assessment n hna are very later. The man research organzatons are Insttute of Fre, hna Academy of Buldng Research, State Key Laboratory of Fre Scence, Unversty of Scence and Technology of hna, the four Fre Research Insttute, hna Academy of Safety Scence and Technology, Tongj Unversty and etc. In recent years, some results have been acheved [1]. There are many methods about fre safety assessment at present whch are categorzed nto qualtatve, halfquanttatve and quanttatve. Qualtatve methods nclude SA, PHA, DOW, MOND, HAZOP, WHAT-IF and etc. Half-quanttatve methods nclude NFPA101M fre assessment system [2], SIA81 method (.e. Gretener) [3], Fre Rsk Index method [4], Gustave method [1] and etc. NFPA101M fre assessment system s a unted method for the assessment of hygene establshment whch s developed n Amerca and manly undertakes dynamc decsonmakng n publc locatons and resdental areas management. SIA81 method s developed n Swtzerland whch takes the losses as a base and takes the experences decson as a complement. Ths method can assess the fre rsk by statstc approach. Fre Rsk Index method was brought forward by Swedsh whch s used to evaluate the fre rsk of frame house n North Europe, s also used n the flammable and non-flammable ter manson-buldng. Gustave method s a plane analyss approach whch estmated the fre rsk of buldng by usng the damage grade of the buldng and the harm grade of the staff and propertes n the buldng. Quanttatve methods nclude L-curve, rspii(england), FIREAMTM, ESRE-Rsk (Australan), ETA, FTA and Fuzzy math method[1]. Majorty quanttatve methods above need a large number of data to calculate the accdental probablty and the consequence of the buldng fre. Snce the establshed tme of hna s short, the changes of poltcs and economy are promnent snce Thus only the fre-related statstcs data snce the 1980s are sutable for these assessment methods. There s a problem belong to small sample whle large nose n usng these data. In order to quanttatve assess fre protecton systems n hna, theoretcal safety control method was put forward n ths study. Safety System Engneerng method was used n ths method to dentfy the rsks of fre protecton system of buldng and dscover the hdden troubles of the system n tme. And a math model about fre control and forecast was developed, whch s based on the Modern ontrol Theory, to evaluate the dynamc safety of fre system scentfcally and make decson to mprove the safety degree of the fre protecton system. A case study was defned, whch derved from the actual buldng. Fre protecton system s a large complex system whch contans plannng, desgn, nstallaton, debuggng, runnng, mantanng, nspecton, management, personnel dsposton and safety conscousness. Those systems were categorzed nto three knds whch are fre technology, personnel dsposton, and management. So the safety evaluaton of fre system s the comprehensve evaluaton of the technology, management and persons, then judge the hazard resources, the control capacty of hazards and safety degree of the system. Theoretcal safety control method, based on the methodology, control-mechansm and math models of Modern ontrol Theory, uses safety checklst analyss, questonnare, scorng method and etc to realze dynamc and closed loop controllng of the safety system. The control process fgure sees the Fgure1. Establshment technology Safety managemen Personnel dsposton System nput Fre safety system Hazards dentfcaton omprehensve assessment System determn Decson-makng and control System adjustment

4 150 HUANG Yan-bo et al. / Proceda Engneerng 11 (2011) Fg. 1 The control process of fre safety assessment 3. The assessment theory and ndexes of the fre fghtng system 3.1. Models (1) The defnton of safety degree [5], S = 12.1lnY = 12.1ln Mt 1 Where, Y s annual mllon casualty rate of system, M s the number of people n the systemt s the average non-accdent tme. (2) The dynamc models of safety degree Safety degree of system s changng dynamcally wth the dfference of safety state of the system. The motvty of dynamc varety s the result of conflct between hazard and control, namely hazard control effect. The safety degree of system s the summaton between prmtve safety degree and hazard control effect of the system n a certan tme. They obey functons (2) and (3), S ( k) = S( k 1) + B( k) 2 B( k) = α βh 3 Where S(k) s the safety degree of annual, S(k-1) s the prmtve safety degree, k s the annual, s the control capacty coeffcent of rsk, H s the hazard coeffcentb(k) s the control effect of annual, are constants, usually, they are=0.0688=0.55 Functon2s the dynamc model of safety degree, t shows that the safety degree of system has accumulatve effects. Functon3s the result of conflct between hazard-h and control- of the safety system. When B(k)>0, t represents that s domnant and S s ncreasng. When B(k)0, t represents that H and are n the same level and S s steady. When B(k)<0, t represents that s nferor and S s decreasng The ndexes wth respect to the control effect of system Hazard coeffcent-h H s comprehensve result of many hazard sources n the system. The followng s the expresson of H: H = γhshph1h 2H 3 4 Where, γ s the correcton ndex of buldng type; Hs s ntrnscally hazard ndex of fre system, H p s the personal densty ndex n buldng, H 1 s the hazard ndex of fre establshment, H 2 s the hazard ndex of fre management, H 3 s the hazard ndex of fre loads of buldng or locaton. Some rsk ndexes of buldng are shown n Table2 [6] : Table 2 the rsk ndex The correcton ndex of buldng type γ Type Workshop Resdence Offce buldng Teachng buldng Hotel Hosptal buldng Busness buldng ndex The personal densty ndex n buldng H p Densty Index ontrol capacty coeffcent of rsk-

5 HUANG Yan-bo et al. / Proceda Engneerng 11 (2011) In order to determne the coeffcent, effect factors nclude runnng state of fre system (whch contans fre control plan, fre-restarted technology, fre detected technology, fre extnct technology and fre ext system), fre safety management, comprehensve qualtes and safety conscousness of personnel should be consdered. Fre control plan nvolves desgn of smoke control, fre compartment, and fre separaton (namely, fre doors, fre wndows, fre curtans, smoke blockng wall, fre safety dstance). Fre-restarted technology contans fre restarted coatng materal, fre resstant walls, fre restarted chemcal, smoke control chemcal and etc. Fre detected technology ncludes smoke detecton, temperature detecton, nfrared detecton, TV montor, ultrasonc detecton, flammable gas detecton and so forth. Fre extnct technology contans water spray auto-fre-extngushng system, foam spray auto- fre-extngushng system, gas spray auto-fre-extngushng system, dry power spray auto-freextngushng system, portable fre extngusher, fre extngusher of push-type, ndoor hydrant, fre fghtng cannon, fre hydraulc gun, fre alarmng equpment and so on. Fre ext system nvolves ext passage, fre elevator, ext sgns, emergency lghts, emergency broadcastng, fre alarm bell, fre power dstrbuton system and etc. The accumulatve expresson of s: n = w 5 Where, s the control capacty ndex of every effect factor, t s scored by usng the relatve safety checklst or detecton rules of fre establshment accordng wth the dfference of the assessment objects. w s the weght of every effect factor whch s scored accordng wth the dfference of the assessment objects, and w =. Fnally, 1 s calculated by formula (5). 4. The case study The case s about the quanttatve rsk assessment of an offce buldng whch has fve layers. For the bass nstance see Table3. Table 3 the bass nstance at the present case-studed Bass nformaton Layer equpment Fre establshment The buldng has fve layers whch are square meter per layer, 40 offces whch are 300 square meters per room, and a man lft. Personnel flux of the buldng s 200 persons per day, and average personnel densty s less than 0.1. There are 400 computers worth 30 ten thousand Yuan, 350 apparatus and nstrument worth about 1000 ten thousand Yuan, 5 severs worth 30 ten thousand Yuan, 200 wall ar-condton worth about 60 ten thousand Yuan. There are many the desks and chars, books and papers, management fles and etc worth about 150 ten thousand Yuan, and ftment materal for the buldng worth 16 ten thousand Yuan. There are 2 ndoor hydrants, 16 AB hand-hold fre extngusher, 6 gas masks, 2 nfrared detector of safety (not for fre), 3 electrc emergency bells at each floor. The buldng has 2 ext stars, 4 exts toward outer on the frst floor. There s 1 emergency lght n every room. There are 3 emergency lghts, evacuaton sgns spaced 12 meters n each corrdor. There s auto-water-spray fre extngushng devces n some fles management offces. Around ths buldng, there are nether outdoor hydrants nor fre fghtng pool Determnng the value of H Accordng wth the basc nformaton of the buldng above and compared wth table 2, let γ =1.1 and Hp=1.0. Let Hs=1 because there has not taken any equpments and methods n the aspect of ntrnscally safety to prevent the domno effect from the rsk-protecton, establshment falure and mss-operatng. Fre load calculaton s the foundaton to forecast the sze and severty of potental fre. Fre load s defned as the gross heat value released from all the combustble matters burnng n the buldng, and the fre load densty s the heat value n area unt. The calculaton equaton of fre load densty s [7] : MvΔhc q = (6) At Where, M v s the weght of one combustble matter (kg); h c s the effectve heat value of one combustble 2 matter (MJ/kg); A t s the total areas (m ).

6 152 HUANG Yan-bo et al. / Proceda Engneerng 11 (2011) Accordng wth equaton (6) and Table 3, the gross heat can be calculated and converted nto the standards equvalent of tmber. The calculated values are that the total heat value s MJ and the equvalent of tmber s MJ/m 2. Then, compared the calculated result wth the densty of fre loads n buldng n Table 4, we get H 3 =3. The advance safety checklst s used to check and nspect the statue of the equpments, establshments, processng, and the management. ompared the results wth the desgn, nstallaton and debuggng fles of the project, we pad the rsk of fre establshment a value that of ths buldng s 78, and pad the rsk of fre system management another value that of ths buldng s 80, whle the full values are 100. Then, compared those values wth the marks n Table 4, we get H 1 1 and H Table4 the rsk ndex II Rsk ndex of fre establshment H 1 Mark < >90 Index Rsk ndex of fre system management H 2 Mark < >90 Index The densty ndex of fre loads n buldngequvalent wood kg/m2h 3 Densty < >50 Index Then, the value of of ths buldng s H = γhshph H 1.1*1*1.0*3*1*0.8= onfrmaton 1 2H The dfferent mpact factors of The operaton of the fre system s nspected or tested one by one based on the rules of fre establshments detecton, and every tems was scored. Because there are a large number of tems, the full mark s set for 1000 ponts for the sake of scorng ratonalty. The safety management, personal dsposton and safety conscousness s scored accordng to the nqury of the staff n the buldng by the way of Queston and Answer. The results were converted to hundred-mark system. (1) The confrmaton of check and testng of fre establshments- 1 In the lght of the rules of fre establshments detecton as shown n Table 5 (here only a segment s shown), the fre establshment n ths case study was checked and tested, and the results are shown n Table 6. There are 500 ponts adapted to the offce buldng whch obtaned 405 ponts that s 81 ponts n hundred-mark system. Table 5 A segment of the rules of fre establshments detecton Number heck tems Grade heck standard heck knd heck tools straght telephone B Qualtatve / 0102 Fre alarm controller The type and the mark of controller Installaton dmenson Installaton dmenson nstallaton fastness extend Should setup straght alarm telephone and call normally(gb and GA ) The mark must be evdent and clear GA and Postve operatng dstance1.2m GB Sde dstance close axs0.5m GB Fastness, statonary and no-slant GB Qualtatve / Quanttatve Quanttatve Qualtatve 5m steel tapelne(the scale s mm) 5m steel tapelne(the scale s mm) level ruler Notce: For every tem, there s a correspondng blank sheet to record the results, here s omtted.

7 HUANG Yan-bo et al. / Proceda Engneerng 11 (2011) Table 6 The check results of ths case study Items No. Grade heck standard Results Score deduct Should set alarm telephone- 119,and can call B normallygb and GA no Should set the outdoor hydrant and fre poolgb A and no The walkway and the offce n the buldng should set Only some rooms of fles B spray water shut-auto fre extngushng systemgb management set The nner ext stars n the publc buldng should set A star well, and other stars over fve layers should set shut star wellgb Not set star well The exts are enough, however, The safety exts of publc buldng sn t less than A only one s opened, and the other two(gb ) three are locked A The numbers of fre extngushers are enough GB and GB The numbers are shortage 15 Total 95 (2)The confrmaton of safety management 2, personnel dsposton and safety conscousness 3 There are 7 buldng managers and 200 persons n offces who are nvestgated, and the evaluaton results are shown n Table 7. Table 7 The evaluaton results of 2 and 3 Persons Number Personnel dsposton and safety conscousness Safety management Score Know some knowledge about fre safety Fre safety state was nspected only at several 7 nformaton. Have fre preventon great feasts and holdays. The fre alarm and conscousness and the capacty of control and detecton system has not been used. The fre 75 management hdden trouble about fre system dd not be mantaned and tested. The buldng managers The persons n offces 200 Know some knowledge about fre safety nformaton. an not be alarmed when frng. Have safety preventon conscousness and some knowledge about escapng ould cooperate wth the others when frng, but they are stll lkely to act alone. From above evaluaton, we get 1 81, 2 =75, and The weghts of -w In order to avod the subjectve effect, Analytc Herarchy Process (AHP) method, whch s based on the modern decson-makng and statstc analyss theory, was appled to calculate the weghs of. AHP method s realzed by a comparatve matrx A, that s A = ( a j ) n n. Where, a = A / Aj s the sgnfcance degree rato between each j two factors. A and A j are valued accordng to the rules n table 8. Furthermore subdvded, the values of them may adopt the mddle numbers such as 2, 4 and 6.In the case study, a trple matrx s used to calculate the weghs of, and ts expresson s, A1 A1 A1 A1 1 3/ 2 3. A = = 2 / A1 1/ 3 1/ 2 1 A1 Where, A 1 represents the check and testng results of fre establshments, A 2 represents the safety management level, and A 3 represents the personnel dsposton and safety conscousness level. 82 Table8 The rules of sgnfcance degree of A and Aj

8 154 HUANG Yan-bo et al. / Proceda Engneerng 11 (2011) Value omparson Results-a j 1 A s as mportant as A j 3 A s more mportant than A j 5 A s much more mportant than A j 7 A s hghly mportant compared wth A j 9 A s extremely mportant compared wth A j After matrx calculaton and normalzaton, we get the weghts of whch are w=( ). Accordng to equaton (5) n = w Ths buldng has been used for fve years, so k=5. Apply the results of and H to calculate equaton (3), obtan B(5)=4.02>0 that represents s domnant and S s ncreasng. 5. Dscusson As shown n Fgure2, the safety degree s dvded nto 5 grades whle 60 ponts s the threshold of pass. Falure rtcal Pass General Excellent Fg. 2 The grades of safety degree Accordng to the state equaton of safety control theory [5] : Y ( k) = (1 ( k)) Y ( k 1) + H ( k) (7) From equaton (7), we conclude that H Y ( k) =. It represents that when the system has been runnng some lm k years, the casualty rates wll keep a stable value. For lmy ( k) = Y (0), Y(0) s the ntal casualty rate that s the casualty rate when the safety degree S0=60. Assumed k 0 the controlled effect of the buldng s basc balance n the frst fve years, then B(1)= B(2)= B(3)= B(4)= B(5)=4.02. The safety degree of system S(5)=80.1 whch s referred from equaton (2). Status of the buldng s excellent whch s concluded from Fgure2. However, the fre management should be strengthened and the correspondng contents of management wll be ncluded n the assessed tems.

9 HUANG Yan-bo et al. / Proceda Engneerng 11 (2011) oncluson (1)In order to realze dynamc and quanttatve fre management and control, a new quanttatve fre safety assessment method Modern Safety ontrol Theory was put forward n the study. (2) Some math models and assessment ndexes of fre system were proposed. (3) The correspondng factors wth H and are found out, and AHP approach s used to calculate the weghts of all those factors. (4) The dynamc model of safety degree was cted whch s changed wth the safety status of the system, and whch s the contradctng consequence between hazard and control n fre system. (5) Ths new assessment method was used to assess an actual case buldng. The results show that ths method s sutable for buldng fre safety assessment. References [1] Fan Wecheng Sun Jnhua Lu Shouxang et al. Methodology of Fre Rsk Assessment[M] Bejng: Publshng ompany of Scence and Technology 2006, [2] NFPA.NFPA550 Gude to the Fre Safety Scence oncepts Tree 1995 Edton. MA,USA,1995 [3]Fontana M.SLA 81-Swss Rapd Rsk assessment method, Insttute of Structure Engneerng. ETH Zurch,Swtzerland,1984 [4]Ftzgerald Robert W. Buldng Fre Safety Engneerng Method, Worcester Polytechnc Insttute, Worcester, Massachusetts, USA: Symposum, Ottawa 1994 [5]Zhang Ypeng Prmary theory and applcaton of safety control(4th) [J] Wuhan: Industry Safety and Dustproof P1~5 [6]L Ynqng Fre Preventon Engneerng of Buldng[M] Bejng: Publshng ompany of hemcal Industral 2004, [7]O. Pettersson. Fre Engneerng Desgn of Steel Structures [M]. Stockholm, Sweden: Publcaton 50, Swedsh Insttute of Steel onstructon, 1976, 33~41.