CN102419799A - Fire fighting system reliability analysis and calculation method - Google Patents

Abstract

The invention belongs to application of a reliability analysis technology to the technical field of fire engineering, and ensures that the using reliability of a fire fighting system is accurately analyzed and calculated. A fire fighting system reliability analysis and calculation method comprises the following steps of: establishing a fire fighting system reliability model and determining reliability units according to the working principle of the fire fighting system, forming a GO chart for establishing the fire fighting system according to the boundary of the fire fighting system and success criteria, and determining a fault judgment method for the reliability units of the fire fighting system according to task analysis of the system and fire code requirements; and substituting fault statistical data of the reliability units of the fire fighting system into a GO model of the fire fighting system to calculate corresponding reliability indexes of the fire fighting system, such as a fault rate, average maintenance time, availability and the like. By the method, the reliability of the fire fighting system can be objectively qualitatively evaluated or accurately quantitatively evaluated, and the method can be widely applied to reliability design, reliability manufacture, fault analysis and system evaluation of the fire fighting system.

Description

A kind of fire-fighting system fail-safe analysis and computing method

Affiliated technical field

The invention belongs to the fire engineering technical applications; Specifically belong to of the application of fail-safe analysis technology at fire protection sector; Comprise the reliability model of setting up the fire-fighting subsystem, confirm fire-fighting subsystem Analysis of Reliability Data and method for sorting, the reliability of fire-fighting subsystem is made qualitative or quantitative evaluation.

Background technology

One) noun and term

1. building fire protection facility and fire-fighting system, repairable system:

Building fire protection facility: the general name that is used for facilities such as fire alarm, fire extinguishing, evacuating personnel, fire separation, fire fighting and rescue action that is provided with in buildings, the structures.Building fire protection facility has constituted the fire-fighting system of a complicacy with key elements such as personnel, environment and management in actual use.

Repairable system is meant and can returns to specified states and worth system of repairing through corrective maintenance.Otherwise be repairable system not, fire-fighting system can be considered repairable system.

2. fire-fighting subsystem

In the fire fighting device system, carry out the combination of a group of parts, assembly or equipment of a certain type of fire-fighting function.According to GA 503-2004 standard, mainly be divided into following nine fire-fighting subsystems according to its fire-fighting function system:

1) fire-fighting power supply-distribution system: comprise municipal power supply, power distribution cabinet, provide generating set, UPS etc. for oneself;

2) waterworks for firefighting: comprise pond, water tank, pump house, municipal water supply, fire department pumper connection;

3) automatic fire alarm system: comprise assembly, alarm controller, alarm device, control output interface, linkage controller, the power autonomous system of triggering;

4) automatic fire extinguishing system: comprise

Automatic sprinkler system: fire fighting supply exports to end water testing device, wet type, dry type, preact are arranged, drenches with rain, water injection system; Gas extinguishing system; Froth fire extinguishing system etc.

5) the manual extinguishing system comprises:

The hydrant fire extinguishing system: mainly be indoor fire hydrant (comprising hose reel) system, wherein indoor fastening enters the mouth from fire fighting supply that whole pipe network, test are fastened, valve, controlling alarm button;

Flame snuffer (other portable extinguishing devices)

6) mechanical air supply and smoke evacuation system (smoke control system): comprise blower fan, switch board, air channel, exhaust opening and air outlet etc.;

7) fire separation and structural defence facility (being called for short the fire separation system) comprising: automatic closing door, fire resisting shutter, the vertical wall of shelves cigarette, fire resisting damper etc.;

8) emergent security system: comprise emergency lighting and evacuation indication system, fire broadcast system, fire telephone.

9) the fire-fighting and rescue back-up system comprises: outside line 119, Fire lift, siamese fire department connection, outdoor bolt etc.

3. subsystem assembly and reliability unit

Assembly is meant the fire product that can independently dispose or the ingredient that constitutes the fire-fighting subsystem, like a fire detector, and a shower nozzle, an exhaust opening, a fire-fighting blower fan, one section pipe network or pipeline etc.

Reliability unit is meant an ingredient that constitutes fire-fighting subsystem reliability model; It is the division of the fire-fighting subsystem being carried out from the concept of function; Can be to constitute by one or some assemblies; Also can be made up of one group of pipe network or pipeline, as in automatic fire alarm system, be the reliability unit that a m in the subsystem gets k voting relation with some detectors.

4. the fault of fire product and inefficacy

The fault of fire product: be can not the put rules into practice state of function of fire product.

Fire product lost efficacy: fire product stops accomplishing the such incident of ability of predetermined function.

Fault is a kind of state description; Inefficacy is an event description; We can say a product failure, be in malfunction, fault after normally product itself lost efficacy state but also possibly before inefficacy, just exist; That is to say that all inefficacies all produce fault, not every fault all is because lost efficacy.

5. the failure criterion of fire-fighting subsystem and unit

Judge the criterion and the foundation of fire-fighting subsystem and fire-fighting reliability unit fault.In the present invention, according to " " building fire protection facility detection technique rules " (GA503-2004) are judged with " fire product site inspection decision rule " related request in (GA588-2005).

6. reliability index

Reliability index of correlation and data are meant the description product reliability level that in each item reliability Work and activity, produced and the various data of situation, and they can be forms such as numeral, chart, symbol, literal and curve.The qualitative assessment reliability of products is the task of Analysis of Reliability Data; The information that provides thus; To and correct the reference of reliability design and aspect defectives such as components and parts, material and technology as prevention, discovery, in reliability engineering, play an important role.

Among the present invention, the reliability index of correlation mainly contains: failure rate, maintenance rate and availability index.Specific as follows.

1) fiduciary level

Fiduciary level is meant equipment from starting working, and trouble-proof probability in time t is represented with R (t):

$R\left(t\right)=\left\{\begin{array}{c}P(T>t)(t\≥0)\\ 1(t\≤0)\end{array}\right.$ (formula 1)

Wherein, T is the normal working hours of equipment, i.e. life-span.

Unreliable degree (claiming the cumulative failure rate again): the probability of cisco unity malfunction, the i.e. probability that breaks down of t time.

F (t)=1-R (t) (formula 2)

2) failure rate (claiming crash rate again)

In the achieved reliability engineering, after the user sometimes more is concerned about the interior operate as normal of equipment time t in the past, the probability that the next unit interval breaks down.Be called rate of breakdown, be designated as λ (t).Its expression formula is:

$\mathrm{\&lambda;}\left(t\right)=\underset{\mathrm{\&Delta;\; t}\&RightArrow;0}{\mathrm{Lim}}\frac{P(t<T\&le;t+\mathrm{\&Delta;\; t}/T>t)}{\mathrm{\&Delta;\; t}}=\frac{f\left(t\right)}{R\left(t\right)}$ (formula 3)

At this, f (t) is the failure density function, the pace of change that reactor product lost efficacy, in fact, f (t)=F ' (t)=-(t) obviously not have failure rate λ (t) sensitivity, failure rate be one dimension to be arranged to R ', its dimension was 1/ unit interval,

3) mean time between failures (MTBF)

MTBF is the equipment reliable expectation value of working time, and its indication equipment is required average integration time before continuous formation fault in service.Its mathematic(al) representation is:

$\mathrm{MTBF}=E\left(T\right)={\&Integral;}_0^{\&infin;}\mathrm{Tf}\left(t\right)\mathrm{Dt}$ (formula 4)

4) the mean lifetime cycle (MCT)

The mean lifetime cycle is the mean value of life of product.Be meant the mean value of time between failures for repairable system.Computing formula is:

MCT=mean time between failures+MTTR=MTBF+MTTR.(formula 5)

5) maintainability

Maintainability is described the complexity that equipment keeps in repair, and it is meant equipment under rated condition, the probability that can repair in the t at the appointed time, and note is made M (t).Its expression formula is:

$M\left(t\right)=P(0\&le;Y<t)={\&Integral;}_0^{t}g\left(t\right)\mathrm{Dt}$ (formula 6)

Wherein, Y is the servicing time of faulty equipment, and P is the probability that equipment is repaired in time t, and g (t) is the maintenance probability density function.

6) maintenance rate: it is the characteristic quantity that characterizes faulty equipment function repair process, refers to that product does not also have at t under the situation of reparation constantly, and the conditional probability of in the next unit interval, repairing is designated as μ (t).Its expression formula is following:

$\mathrm{\&mu;}\left(t\right)=\underset{\mathrm{\&Delta;\; t}\&RightArrow;0}{\mathrm{Lim}}\frac{P(t<Y\&le;t+\mathrm{\&Delta;\; t}/Y>t)}{\mathrm{\&Delta;\; t}}=\frac{g\left(t\right)}{1-M\left(t\right)}$ (formula 7)

7) MTTR (MTTR): similar with MTBF, MTTR is the mathematical expectation of Y servicing time, and its expression formula is: $\mathrm{MTTR}=E\left(Y\right)={\&Integral;}_0^{\&infin;}\mathrm{Tg}\left(t\right)\mathrm{Dt}.$ (formula 8)

8) availability: refer to that under rated condition equipment is the probability of t ability operate as normal at any time, representes with A (t).

In reliability model, generally only be concerned about its stable state availability, its computing formula is:

$A=\frac{\mathrm{MTBF}}{\mathrm{MCT}}=\frac{\mathrm{\&mu;}}{\mathrm{\&lambda;}+\mathrm{\&mu;}}$ (formula 9)

9) mean failure rate number of times: since moment t=0 normally, at (t ₁, t ₂) in the time interval, the mean value of each product bug number of times in all over products.Symbolization W (t ₁, t ₂) expression.Computing formula is:

$W(t_1,t_2)={\&Integral;}_1^{{\mathrm{<figure-callout\; id="2"\; label="t"\; filenames="HSA00000654891200011.png,HSA00000654891200012.png"\; state="\{\{state\}\}">t</figure-callout>}}_2}\mathrm{\&omega;}\left(t\right)\mathrm{Dt}$ (formula 10)

Wherein ω (t) is meant in any time t＞0 all over products, at the probability of next unit interval internal fault.

Reliability index is described the characteristic quantity of " normal-fault " process; The maintainability index is described the characteristic quantity of " fault-normal " process, and wherein, what fiduciary level, unreliable degree were described is [0; T) characteristic in the time interval, probability density of failure and failure rate are described the characteristic of particular moment t (t＞0).Index such as availability and degree of unavailability is to describe in " normal-fault-normal-fault " cyclic process, describes the characteristic quantity of t＞0 constantly the time, and the mean failure rate number of times is described is [0, t) the average cumulative characteristic in the time interval.

Two) current domestic and international analysis and assessment technique to fire-fighting system

1) the fire-fighting performance of each fire-fighting subsystem of test evaluation or the statistical property of macroscopical sample; Accomplish through test or performance calculating; Belonging to the dependability design of fire-fighting system, is not the method for the reliability characteristic (like failure rate, maintenance rate, availability etc.) of independent fire-fighting system of assay in life cycle.

2) utilization " building fire protection facility detection technique rules " (GA503-2004), whether " fire product site inspection decision rule " (GA588-2005) meet the requirements to fire-fighting system and do to judge immediately; Be to put sometime the function of fire-fighting system is done a whether qualified judgement; Usually more test report is only claimed and can't accurately to be described fire-fighting system operating characteristic in a period of time state is responsible at that time.Cause and can't correctly estimate the reliability of fire-fighting system, perhaps the actual availability of the system of some nominal test passes is very low.

3) " with building fire protection facility usability assessment guide rule " who is working out estimates the reliability of fire-fighting system with the method for step analysis; Confirm decision criteria owing to adopt the method for expert's marking at aspects such as key element division, weight judgements; The suggestion that different expert groups provides can not be unified, and makes that fire-fighting system reliability evaluation result is objective inadequately.

Three) systems reliability analysis notion

The principle of work of application system is set up reliability block diagram; The reliability index of system is analyzed and calculated is the basic skills in the reliability engineering technology; Study the reliability of a product or system and can divide two kinds: i.e. basic reliability and mission reliability, basic reliability is defined as the time or the probability of product no-failure operation under defined terms.Mission reliability then is defined as product is accomplished predetermined function in assignment of mission ability.Corresponding with it then is basic reliability model and mission reliability model, and the basic reliability model is generally counted the product that system forms the reliability of each unit or assembly, can regard a kind of model of measuring cost of use as,

Mission reliability then is to be used for estimating that product accomplishes the probability of predetermined function in the process of executing the task; The predetermined action of each unit in this task of completion is described; In order to a kind of model of tolerance work validity, mission reliability divides inherent reliability and dependability again.

Inherent reliability (inherent reliability): manufacture and design the product of giving and the reliability that under desirable use and guarantee condition, is had.Here, the inherent reliability of fire-fighting system is meant that after the fire-fighting system final acceptance of construction, it is qualified that the operational administrative personnel train, the reliability upper limit that system has when formally putting into operation.Mainly relevant with quality, design, the delivery receiving acceptance supervision of fire-fighting system.

Dependability (operational reliability): product uses the reliability that is demonstrated in actual environment, the combined influence of factors such as its reflection product design, manufacturing, use, maintenance, environment.

The present invention mainly studies the dependability of fire-fighting system, refers to that fire fighting device uses the reliability that is appeared in actual environment, the combined influence of factors such as its reflection product quality, system design, delivery receiving acceptance, operation maintenance.

Four) systems reliability analysis technology

GO method analytical technology

The GO method is a kind of successfully to be system's probability analysis technology of guiding.This method is proposed by U.S. Kaman scientific company in middle 1960s at first, is used to solve the integrity problem of complication system.The GO method is mainly used in system's operation and has complex time sequence or system state time varying system.The GO method generally is successfully being the starting point that considers a problem, and the GO symbol through parts directly converts the GO illustraton of model into from schematic diagram, and with the probability of happening of the various states of GO method operation program calculating institute analytic system.Mainly be used for the fiduciary level or the availability of evaluation system.The GO modeling pattern is a method of induction, and its quantitative Analysis can directly be carried out, and can not obtain accurate result and do not need to obtain in advance minimal cut set.

The state that operation meets signal flow in the GO method can be represented the various states of parts and system, can describe the various states incident well, and GO figure itself reflected the order that signal successively arrives, so can reflect the sequential property of system.

The target of GO method fail-safe analysis is to be confirmed the characteristic quantities of system by the characteristic quantities of system's ingredient (being referred to as the unit).The ultimate principle of GO method is directly to translate GO figure (as shown in Figure 1) to system diagram or shop drawing.Perhaps represent logical relation with the concrete parts of operational character representative among the GO figure,, carry out the GO computing then, obtain the dependability parameter of system with the representative of signal flow attended operation symbol concrete logistics or representative process in logic.

Connecting line in the GO chart becomes signal wire, and it unites the input and output of processing unit.Signal is represented certain physical quantity or information, for example, and the electric current in ducted flow, the circuit.The GO method has defined 17 types standard operator (corresponding types 1-17), shown in Fig. 2-9.The figure Chinese words is represented names of operators, digitized representation style number in the operational character figure, and arrow S represents input signal, arrow R representative output signal.

When the GO method is applied to repairable system, can progressively calculate the reliability indexs such as availability, failure rate and MTTR of each signal flow and system by GO figure.

The unit of the operational character representative of repairable system is a repairable system, has only success status and malfunction.During stable state, the probability of operational character success status is exactly the availability of unit, and the probability of operational character malfunction is exactly the degree of unavailability of unit, and the failure rate of operational character and maintenance rate are exactly failure rate and the maintenance rate that can repair the unit.

Signal flow is represented the preceding part repairable system of this signal flow in the GO method analytic process, has only success status and malfunction.During stable state; Signal flow success status probability and malfunction probability are exactly the availability and the degree of unavailability of the part repairable system of its representative, equivalent fault rate that the failure rate of the part repairable system of signal flow representative and maintenance rate are called signal flow and equivalent maintenance rate.The success status probability of signal flow, equivalent fault rate and equivalent maintenance rate are not independently, if only provide the computing formula of any two amounts in the characteristic quantities, just can try to achieve all characteristic quantities.

It is exactly along signal flow sequence that the GO standard measure calculates, and calculates the characteristic quantities of exporting signal, output signal to the last by the characteristic quantities of input signal and the dependability parameter of operational character.Mean reliability characteristic when the characteristic quantities of final output signal has been represented total system stable operation can be made evaluation to system with this.

The basic step that the GO method is used

The GO method is used for the detailed process of systems reliability analysis shown in Fig. 2-9, and complete analysis has define system, confirms the border, confirms successful criterion, sets up GO figure, imports 7 steps such as data, GO computing and evaluation system.Preceding 4 steps are through systematic analysis, set up GO figure, and back 3 steps are to accomplish the GO method analysis of system through the GO computing, the reliability of system is made an appraisal, so the analysis of GO method mainly are to set up GO figure and carry out GO computing two main tasks.

Preceding 3 steps of GO method analytic process are carried out systematic analysis, and the 4th step accomplished and sets up GO figure, and concrete steps are following:

1. define system

The first step of systematic analysis is the system that definition is analyzed; Stipulate the scope of system; And the function of definite system, the reliability index of clear and definite system. confirm the composition of system then, confirm element, parts or subsystem that system comprises; Be referred to as the unit of system, provide the unit structural drawing related that comprises in the system with each unit.The function of analysis system, and the relation of the reliability function between clear and definite each unit.

2. confirm the border

After the system definition; Confirm that system boundary is exactly input, the output of confirming system; Confirm the interface of system and other system. the input of system is that system is desired, comes from external event (like power supply, water source) or other system of system, and these external events or other system are with the representative of input operation symbol; Its output signal is exactly the input signal of system. and the output of system is one group of output signal can representing system state, and these signal flows can be used as the input signal of other system.

3. successfully push away then

The success criterion be want clear and definite what be the normal operating condition of system; Confirm that the output signal of the desired minimum of the normal operation of system is in the set of success status. for example in the fluid system that 3 tunnel outputs are arranged; In the time of can stipulating that 1 road or 2 tunnel outputs exist, system can normally move, as successful criterion. and system evaluation and GO computing are the basis with successful criterion; The success criterion is different, and evaluation result is different.

4. set up GO figure

Preceding 3 steps are carried out systematic analysis, set up GO figure from the system construction drawing direct modeling then and carry out:

(1) confirms operational character and type thereof

Go on foot " define system " the definite unit that system comprised and the function of unit according to the 1st; With the unit in the operational character representative system structural drawing; And confirm the type of operational character by the function of unit. in GO figure, draw and system construction drawing operational character symbol one to one; Indicate operator types with numeral in the operational character symbol, operational character should comprise all unit in the system.Complicated to relatively, the unit system with more, some unit can not lose efficacy or failure rate very low, can in GO figure, omit, to simplify GO figure and to calculate, the choice of unit will be passed through systematic analysis and confirm.In the complication system if repeated cellular construction or subsystem; For plucking GO figure; Such structure or can represent with an operational character in system is called the super operation symbol, and the super operation symbol has specific input signal, output signal and operation rule thereof.

(2) signal flow attended operation symbol

Based on definite system input border of the 2nd step " confirming the border ", represent external event to become other system with the input operation symbol.From the beginning of input operation symbol, its output signal flow that on GO figure, draws, the corresponding operational character of the system that is connected to. then according to functional relationship between the system unit and logical relation,, continue the signal flow that draws, be connected to next operational character to be guiding successfully.Should report according to the logical relation that merges when having signal flow to merge in the connection procedure, increase logical operator.Signal flow attended operation symbol; The output signal of system's output boundary of in systematic analysis, confirming; Can there be one or more output signals in system. when there is a plurality of output signal in system, can according to the 3rd the step " successful criterion " definite system normally move the condition that needs, increase logical operator; The array output signal obtains the successful integrated output signal of representative system.

(3) operational character numbering

All operations symbol among the GO figure is numbered, and the numbering of operational character is unique, and repetition can not be arranged.The operational character numbering of a plurality of same types is different, has represented the Different Individual of same unit in the system.

(4) signal flow numbering

Signal flow among the GO figure is numbered, and the numbering of signal flow is unique, and the signal that all goes out of operational character is as the criterion, and a plurality of output signals will be given different numberings, go into to a plurality of operational characters, but numbering is same, can not increase.

(5) inspection GO figure

Confirm whether GO figure meets following rule, otherwise correct by above step.

A) all operational character must be indicated its style number and numbering, and numbering must be unique.

B) an input operation symbol (type 4 or 5) to be arranged at least.

C) all signal flows must be indicated numbering, and numbering must be unique.

D) input signal of arbitrary operational character must be the output signal of another operational character, can increase virtual input operation symbol.

E) signal flow begins to lead to representative system output from the input operation symbol, forms signal flow sequence, does not allow circulation.

5. input data

Fire-fighting system work after a period of time; Working condition that can recording system comprises fault-time of each components and parts, data such as servicing time; Specifically see attached list, can obtain the failure rate λ and the maintenance rate μ of current system through statistical treatment raw data.

6, GO computing

Obtain after the basic data of each operational character, we are updated to GO figure to these basic datas and carry out the GO computing.

In the GO method, we further obtain the computing formula of other indexs with the desired value of failure rate (λ) and maintenance rate (μ) basic data as the G computing.

For different operation symbol among the GO figure, the relation of input and output can be used following formulate:

(1) Class1: two condition unit

$\left.\begin{array}{c}{P}_R\left(1\right)=P_S\left(1\right)P_C\left(1\right)\\ P_R\left(2\right)=P_S\left(2\right)+P_S\left(1\right)\&CenterDot;P_C\left(2\right)\\ {\mathrm{\&lambda;}}_R={\mathrm{\&lambda;}}_S+{\mathrm{\&lambda;}}_C\\ {\mathrm{\&mu;}}_R={\mathrm{\&lambda;}}_R\&CenterDot;P_R\left(1\right)/P_R\left(2\right)\end{array}\right\}$ (formula 11)

(2) type 2: or door

$\left.\begin{array}{c}{P}_R\left(1\right)=1-P_R\left(2\right)\\ P_R\left(2\right)=\underset{i=1}{\overset{M}{\mathrm{\&Pi;}}}{P}_{\mathrm{Si}}\left(2\right)\\ {\mathrm{\&mu;}}_R=\underset{i=1}{\overset{M}{\mathrm{\&Sigma;}}}{\mathrm{\&mu;}}_{\mathrm{Si}}\\ {\mathrm{\&lambda;}}_R={\mathrm{\&mu;}}_R\&CenterDot;P_R\left(2\right)/P_R\left(1\right)\end{array}\right\}$ (formula 12)

(3) type 5: the mono signal generator

$\left.\begin{array}{c}{P}_R\left(1\right)=P_C\left(1\right),P_R\left(2\right)=P_C\left(2\right)\\ {\mathrm{\&lambda;}}_R={\mathrm{\&lambda;}}_C,{\mathrm{\&mu;}}_R={\mathrm{\&mu;}}_C\end{array}\right\}$ (formula 13)

(4) type 6: have ready conditions signal and the element of conducting

$\left.\begin{array}{c}{P}_R\left(1\right)=P_{S1}\left(1\right)\&CenterDot;P_{S2}\left(1\right)\&CenterDot;P_C\left(1\right)\\ P_R\left(2\right)=P_{S2}\left(2\right)+P_{S1}\left(1\right)\&CenterDot;P_{S2}\left(2\right)+P_{S1}\left(1\right)\&CenterDot;P_{S2}\left(1\right)\&CenterDot;P_C\left(2\right)\\ {\mathrm{\&lambda;}}_R={\mathrm{\&lambda;}}_{S1}+{\mathrm{\&lambda;}}_{\mathrm{<figure-callout\; id="2"\; label="S"\; filenames="HSA00000654891200011.png,HSA00000654891200012.png"\; state="\{\{state\}\}">S</figure-callout>}2}+{\mathrm{\&lambda;}}_C\\ {\mathrm{\&mu;}}_R={\mathrm{\&lambda;}}_R{P}_R\left(1\right)/P_R\left(2\right)\end{array}\right\}$ (formula 14)

(5) Class1 0: with door

$\left.\begin{array}{c}{P}_R\left(1\right)=\underset{i=1}{\overset{M}{\mathrm{\&Pi;}}}{P}_{\mathrm{Si}}\left(1\right)\\ P_R\left(2\right)=1-P_R\left(1\right)\\ {\mathrm{\&lambda;}}_R=\underset{i=1}{\overset{M}{\mathrm{\&Sigma;}}}{\mathrm{\&lambda;}}_{\mathrm{Si}}\\ {\mathrm{\&mu;}}_R={\mathrm{\&lambda;}}_R\&CenterDot;P_R\left(1\right)/P_R\left(2\right)\end{array}\right\}$ (formula 15)

7, evaluation system

System's operational reliability data that computing obtains according to GO, the time period that belongs to fault and service record data is the investigation time, can know, during this period of time, the average work probability of system; The number of times that breaks down every year on average; The every generation primary fault of system, average used servicing time.The average time interval of the double fault of repairable system.And with this as statistics, compare with data that front and back are surveyed, can obtain system's operational reliability trend, compare with the inherent reliability data and can obtain system reliability traffic coverage and state.

The fault tree analysis technology

In addition with this method approximate adopt FTA (Fault Tree Analysis in addition; Hereinafter to be referred as FTA) be a kind of important method of estimating the complication system reliability and security; Be exactly in system design process, through the various factors (comprising hardware, software, environment, human factor etc.) that possibly cause the system failure is analyzed the logic diagram that draws (being fault tree); Thereby confirm that the various of system failure reason possibly make up and probability of happening; With the computing system probability of malfunction, take corresponding corrective action, improve a kind of Design and analysis methods of system reliability.

FTA with do not hope to take place, as the incident (top event) of thrashing criterion as the target of analyzing; The first step goes to seek all immediate causes that causes top event; Second step went to seek all immediate causes that cause above-mentioned each immediate cause again; Below in like manner, in layer look for down.Through so successively pushing away all possible reason of tracing back downwards, till not needing again further analysis to go down.Like this; Just possibly find out the logical relation between the thrashing of various factors (bottom event) such as contingent hardware failure, software errors, human error, environmental impact and top event representative in the system; And be linked to be the tree-shaped figure of a handstand with the logic gate symbol, be called fault tree or failure cause tree.FTA has characteristics such as intuitive is strong, dirigibility is big, versatility is good, and its basic step is:

(1) builds fault tree;

(2) set up the fault tree mathematical model;

(3) fault tree qualitative analysis;

(4) fault tree quantitative test.

The FTA method is convenient to carry out qualitative analysis as a kind of systems reliability analysis method, also can carry out quantitative Analysis.Its research causes the various direct and remote cause of this incident of thrashing, and between these incidents, sets up logical relation.Thereby this method can help to seek latent defect in the design and the production phase of system; Can help to carry out failure diagnosis in the operation and maintenance stage of system, quantitative basis is provided for improving system design.FTA is usually used in the following aspects: the critical component of confirming security; Examine product demand; The checking product reliability; Estimate product risks; Investigation accident and incident; The evaluation Change In Design; The cause-effect relationship of displaying incident; Identification common cause failure etc.

Its applicable scope is to carry out the generality analysis based on the probability of malfunction statistics to the reliability of a certain type systematic.Need carry out detailed probability statistics to the reason that possibly cause fault.Be applicable to the reliability properties of analyzing great amount of samples, only be suitable for not having the system of sequential.And, can't foresee concrete possible facility fault mode to a certain dependability analysis that sequential, multimode fire-fighting system are specifically arranged, therefore should not adopt the method.

Summary of the invention

Existing fire-fighting system detects and the defective of assessment method in order to overcome, and the present invention has set up fire-fighting system fail-safe analysis and computing method based on the GO method according to the principle of work and the reliability engineering method of fire-fighting system.These method main contents are following:

1. according to the principle of work of fire-fighting system, fire-fighting subsystem reliability model block diagram such as Fig. 4-shown in Figure 9 have been set up.

2. according to the reliability block diagram of fire-fighting subsystem, set up fire-fighting subsystem GO method analysis chart such as Figure 10-shown in Figure 15

3. according to the fire codes requirement, confirm that the fire-fighting subsystem is a repairable system, the algorithm of confirming its GO graphic operation symbol is suc as formula 11-formula 15.

4. the failure criterion of fire-fighting unit and the reliability data statistical form of fire-fighting unit are set up in the supervision and management practice of implementing according to fire-fighting.

The present invention can analyze the reliability (success or failure, normal or fault) of fire-fighting system qualitatively, the reliability index of quantitative calculation fire-fighting system (failure rate/maintenance rate/availability etc.), and it is more objective to make the Reliability Analysis of fire-fighting system.

Technical scheme

The technical scheme that the present invention adopts is: at first according to the performance purposes and the principle of work of fire product, confirm its reliability block diagram, according to the task analysis of product, set up the criterion of fire-fighting system reliability unit critical failure; Put the operation and the test data of fire-fighting system in order, confirm the fault data of corresponding fire-fighting system unit.Border and failure criterion formation according to fire-fighting system are set up corresponding GO figure, bring the data of corresponding unit into GO method model, carry out the reliability data that computing can obtain corresponding fire-fighting system: like failure rate, availability etc.Main flow process of the present invention is as shown in Figure 3: mainly contain following steps:

1, sets up the reliability model of fire-fighting subsystem

Mission requirements according to the definition of system, principle of work, design; Confirm the function of system, the main task of descriptive system function and secondary task, the environmental baseline of analytic system, each several part, unit, components and parts lost efficacy to the influence of systemic-function; The function of each ingredient of system and the dependence between the reliability; On the basis of schematic diagram, the dependability of drawing logic diagram is set up mathematical model.

2, confirm the division and the criterion of fire-fighting unit.Quoting of unit should be confirmed its reliability unit type according to function, purposes, the correlativity of each assembly in the reliability model from related specifications and rules, and considers whether to exclude the unit.

3,, set up main fire-fighting subsystem GO figure, and the algorithm of confirming GO graphic operation symbol with reference to repairable system is suc as formula shown in the 11-formula 15 at definite cell type and guarantee exhaustively on the basis.

4, confirmed the failure criterion of fire-fighting unit.Require to confirm the failure criterion of its system unit according to function, purposes, degree of protection and the fire codes of object of protection.

5, having set up fire-fighting unit reliability data statistical form, is criterion with this failure criterion, and the service data of each unit of convergence analysis fire-fighting system is confirmed its cell failure rate and MTTR.Repairable system is to be in normal operating conditions and the shutdown maintenance state system among alternately.System breaks down and accomplishes maintenance all has randomness.Fire-fighting system can be regarded repairable system as, and one group of characteristic quantities that system reaches after stablizing is: shown in 22:

Failure rate λ maintenance rate μ

(formula 16)

(formula 17)

F also be on average repair the unit interval number of times and average period unit interval number.

6, confirmed the algorithm of fire-fighting system, will carry out computing, obtained the failure rate and the availability of fire-fighting system to be analyzed with the cell data substitution GO of the system method model of confirming.

7. in addition; On the basis of setting up the fire-fighting system reliability model, also can be through analysis to system reliability model, the reliability model of system possibly be series connection model, parallel model, series-parallel connection model or voting pattern type; It also possibly be their combination; Or complicated model etc. more, can be through system unit being carried out probability statistics, the applied probability statistic algorithm is confirmed the reliability index of system.

Embodiment

For a fire-fighting system to be analyzed; At first through compiling the service data of the system of obtaining; Like fault record, test record etc.; Because mostly the operational process of fire fighting device is to have the process of the flow of material (flow, electric current, air-flow) of sequential, can use the GO method its reliability is analyzed, be example (the related fire fighting device reliability index numerical value of this example demonstration is the hypothesis based on the real case statistics) with the automatic fire alarm subsystem:

One), define system, confirm the cell failure criterion

Automatic fire alarm system is by trigger device, Fire alarm device and have the fire alarm system that the device of other subsidiary function is formed.It can be at the fire initial stage; Physical quantitys such as smog, heat and optical radiation with burning produces become electric signal through fire detectors such as temperature-sensitive, sense cigarette and sensitization, are transferred to fire alarm control unit; And demonstrate the position that fire takes place simultaneously, write down the time that fire takes place.

Its system works principle is as shown in Figure 6:

According to the partly failure criterion of definite fire-fighting unit of automatic fire alarm in " the fire product field quality check is judged rules ", mainly comprise:

The cell failure criterion:

1), fire detector

Smoke point detector

Should under the effect of test flue gas, move,, and start the detector alarm alarm lamp to fire alarm control unit output fire alarm; The detector alarm alarm lamp should keep before hand-reset.

Line style light beam smoke detector

When the dim light value to irradiating light beam reaches 1.0dB～10dB, should start the detector alarm alarm lamp to fire alarm control unit output fire alarm in 30s.

Point type, line-type heat detector

Should under the effect of test thermal source, move, to fire alarm control unit output fire alarm; Point detector is reported to the police should start the detector alarm alarm lamp, and should before hand-reset, keep.

Flame (or sensitization) detector

Should under the test light source effect, in the response time of regulation, move, and to fire alarm control unit output fire alarm; Detector with warning alarm lamp should start the warning alarm lamp simultaneously, and should before hand-reset, keep.

Combustible gas probe

Should meet the 4.1st of GB15322-94 " combustible gas probe technical requirement and test method ", the 4.6th requirement.

2), manual pull station (hydrant alarm button)

When being triggered, should export fire alarm, simultaneously the warning alarm lamp of start button to alarm controller; Should be able to hand-reset.

3), fire alarm control unit

Fire alarm control unit (zone, concentrated, general)

Fire alarm function, fault alarm function, self-checking function, demonstration and clocking capability etc. should meet the related request of GB4717-93 " fire alarm control unit general technical specifications " 4.2.1.2-4.2.1.6 bar.

Should be converted to the standby power supply power supply during primary power source de-energizes automatically, should be automatically converted to the primary power power supply after primary power recovers, and should show the state of active and standby power supply respectively.

4), fire display panel

Should meet GB17429-1998 " fire display panel general technical specifications " 3.2.1.2 bar requirement.

5), fire protection linkage control equipment

Should meet GB16806-1997 " fire protection linkage control Device-General technical conditions " 4.2.4,4.2.5, the requirement of 4.2.6 bar.

Line between fire protection linkage control equipment and input/output module opens circuit, during short circuit, should be able in 100s, send sound, light fault-signal that obvious difference is arranged with fire alarm signal.

The combustible gas alarm controller

Combustible gas alarm function, fault alarm function, this machine self-checking function, demonstration and clocking capability etc. should meet the relevant regulations of GB16808-1997 " combustible gas alarm controller technology require and test method " 3.2.2,3.2.4-3.2.6 bar.

Should be converted to the standby power supply power supply during primary power source de-energizes automatically, should be automatically converted to the primary power power supply after primary power recovers, and should show active and standby power supply status respectively.

6), Fire alarm device

Should after the control signal that receives fire alarm control unit output, send alarm or sound, light alarm.

Neighbourhood noise is greater than the place of 60dB, and the sound pressure level of sound alarm should be higher than ground unrest 15dB.

Two), confirm the border

In this system, power supply of the system that is input as of system and fire signal are output as fire shows signal, alarm signal and output control signal.

Three), successful criterion

According to existing standardized administration requirement, the duty of system has following:

1) the no condition of a fire, normal monitoring state (non-fault is reported to the police and the wrong report fire alarm);

2) State of alarm comprises two kinds of situations of fire and test.All the other are malfunction.

Failure criterion: the system failure has following situation:

System circuit shows fault alarm or has individual device to show fault (failover shielding point).

False alarm: system circuit false alarm, individual device false alarm.

Do not report to the police: system circuit is not reported to the police; Individual device is not reported to the police.

The interlock functional test is defective: linked system output does not meet designing requirement.

The success criterion is:

Four), set up GO figure

According to the fundamental diagram of automatic alarm system, according to the logical relation of the components and parts of forming system and the process of information flow, the GO figure that obtains automatic alarm system is shown in figure 12.

Five), input data

Automatic alarm system work after a period of time; Working condition that can recording system comprises fault-time of each components and parts, data such as servicing time; Specifically see attached list, can obtain the failure rate λ and the maintenance rate μ of current system through statistical treatment raw data.Suppose that fire detector has 70, in this process, we do not consider the process of repairing, and the failure rate procurement process of fire detector is as shown in table 1 below:

Table 1 cell failure rate reckoner

If use the data in 1 year, the failure rate of every month is last row in this year.Here, we get its mean value, to reflect the failure condition of this year.Obtain failure rate=0.1903 (inferior/month), further obtain λ=0.000264 (inferior/time)=2.29 (inferior/year).In like manner, the failure rate of other elements also can obtain.

Statistics obtains its maintenance rate in the reparation record sheet from fire detector again, and we get interval time is 2 months, and computation process is as shown in table 2 below:

Table 2 unit maintenance rate reckoner

In like manner we write down the time of repairing element, and μ=0.076358 (1/h), other elements also can obtain maintenance rate separately according to this statistical method.

Further; Can obtain the failure rate of each components and parts in the automatic alarm system by

; Maintenance rate and mean failure rate probability thereof, specifically see the following form 3:

Table 3 system dependability statistical form

Six), GO computing

Obtain after the basic data of each operational character, we are updated to GO figure to these basic datas and carry out the GO computing.

The calculating of system signal stream

Through calculating, obtain the result of the characteristic quantities of signal flow 9, as shown in table 4 below:

Table 4 GO method is analyzed---system signal stream reckoner 5

Seven) evaluation system

Signal flow 9 is the output of automatic alarm system reliability, and it has reflected the characteristic of system reliability, specifically sees the following form 5:

Table 5 fire-fighting subsystem Mission Reliability Index

The system reliability index	Signal flow	9
			The mean failure rate probability	0.013
Average work probability	0.987
		Mean failure rate number of times/year	12.50
Failure rate λ/year	12.66
		Maintenance rate μ/hour	0.11
The average operation time/hour	691.91
		The MTTR/hour	8.80
Mean lifetime cycle/hour	700.68

The invention has the beneficial effects as follows: set up unique reliability model according to the principle of work of fire product; The service data that fire-fighting system is scattered merges; Reliability to fire-fighting system is carried out qualitative or quantitative evaluation; Objective effective, evaluation result is undisputed, has avoided the inaccurate of existing method and not objective.

Claims (4)

1. fire-fighting system fail-safe analysis and computing method; Comprise: confirm fire-fighting system border and successful criterion, confirm the reliability index of fire-fighting system component units, set up the reliability model and the GO method analysis chart of fire-fighting system according to the principle of work of fire-fighting system; Analyze and calculate the reliability index of fire-fighting system; It is characterized in that: set up the GO method illustraton of model of fire-fighting system according to the principle of work of fire-fighting system, the reliability of fire-fighting system is analyzed and calculated to utilization GO method.

2. method according to claim 1 is characterized in that: confirm the border and the successful criterion of fire-fighting system, confirm the reliability index of fire-fighting system component units.Scope in this fire-fighting system comprises: the fire product that independent can independently selling possesses specific function, fire-fighting subsystem (as: fire-fighting electric power system, waterworks for firefighting, automatic fire alarm system, automatic sprinkler system etc.) and whole fire fighting device system (comprising aforementioned its all or part of fire-fighting subsystem); According to factors such as the importance of fire-fighting system institute object of protection, fire risks; In conjunction with the NFA laws and regulations requirement; Set up the failure criterion of fire-fighting system unit and subsystem, confirm the unit reliability data of fire-fighting system according to the existing management accounts of fire-fighting system.

3. method according to claim 1 is characterized in that: according to the principle of work of fire-fighting system, set up the reliability block diagram and the GO method analysis chart of fire-fighting system.On the basis of the border of confirming fire-fighting system and successful criterion; Principle of work and operating process according to fire-fighting system to be analyzed; The flow direction and control forms in conjunction with the inner actual contents stream of fire-fighting system (current, electric current, gas stream); Confirm the correspondence analysis unit, set up the GO method analysis chart of fire-fighting system.

4. method according to claim 1; It is characterized in that: use the reliability that the GO method is analyzed fire-fighting system; In definite fire-fighting unit reliability data and set up on the basis of fire-fighting system GO method analysis chart; Use GO corresponding operation rule and calculate the output valve of fire-fighting system reliability, can adopt manual calculation and Automatic Program to calculate.

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