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Evaluation method for safety performance of heptafluoropropane gas fire extinguishing

Edit:Jiangsu Yongtai Fire Engineering Co., Ltd.UpDate:2019-12-06

Selection of safety performance assessment methods for gas fire extinguishing system conditions At present, there are dozens of various safety assessment methods, each of which has its own characteristics and is suitable for specific occasions. The evaluation methods recommended by relevant standards and data are: checklist method, advance hazard analysis method, hazard and operability research method, failure type and impact analysis method, fault tree analysis method, event tree analysis method, and hazard index evaluation method. and many more. According to the typical problems in the safety and reliability of gas fire extinguishing system products currently used in China, the author mainly uses two types of assessment methods: one is to analyze the various hidden dangers existing in the system by using the pre-danger analysis method and put forward the disposal requirements The second is to use the fault type and impact analysis method to carry out targeted analysis and evaluation of the main components of the product.

2.1 Advance Hazard Analysis

Advance hazard analysis (PHA) is a qualitative system safety analysis method.Whether in the system design or development, or in the process of use, the results of the hazard analysis can be used to put forward the precautions to be followed and Regulations, pointing out the main dangers, and taking effective measures to eliminate, reduce and control related non-safety factors. In particular, it can be used to formulate design management methods and implement technical responsibilities, and can be compiled into safety checklists to ensure implementation. Through the pre-danger analysis, the following basic goals should be achieved: first, identify all major risk factors related to the system (the probability of accidents is not considered in the initial identification); second, identify the reasons for the risk factors; The third is to assume that risk factors do occur, to estimate and identify the impact on the system; the fourth is to classify the identified risk factors, the classification criteria are as follows: Level I-negligible, will not cause personal injury and system "damage". Level Ⅱ-critical, will not cause personal injury and "" damage to the main system. Level-dangerous (fatal), will cause personal injury and "" main system damage. Level Ⅳ-destructive (disaster It will cause "" personal death or major loss, and the system will be scrapped; five is to find out ways to eliminate or control "" dangerous methods or prevent loss. "" The identification of major risk factors is an important part, and But "" can be thorough and detailed without omissions, otherwise the analysis will be wrong. The analysis must be combined with "" the actual situation of the specific gas fire extinguishing system. "

"2.1.1 Application Examples"

"Table 1 is an example of IG-541 high pressure inert mixed gas fire extinguishing system" "Hazard analysis example."

"2.2 Failure Types and Impact Analysis Methods"

"Failure mode and impact analysis method (Failure mode and effecr" "Analysis, FMEA) also belongs to the qualitative analysis method, in the atomic energy industry," "the electrical industry, the instrument industry has a wide range of applications, in the chemical industry application" "also has obvious effects . DuPont of the United States regards it as a major link in the safety assessment of the three "phases" of chemical plants. The United States Aviation and Aviation Administration of China has used it as a risk analysis method for aircraft engine operating conditions assessment as early as 1957. The characteristic of this method is to start with the risk analysis of the key components and key raw materials that make up the product, and analyze its impact and the countermeasures one by one. Its basic content is to find out the types of failures that may occur in each key part and have a significant impact on safety performance, analyze its impact on personnel, operations, and the entire system, and answer the "if ... how?" Question. Failure types and impact analysis are usually

The basic steps of the analysis and evaluation of the predetermined analysis table are as follows:

(1) Confirm the system composition and working principle, and identify the key components and key raw materials that constitute the system product;

(2) Prepare each to be analyzed

Partial features that determine the effect of operations and the environment on the system;

(3) Analysis and detection of the main failure mechanism;

(4) Find out the failure type of each part on the failure of the product and the entire system. When each component (or material) has more than one type of failure, the impact of each type of failure must be analyzed and listed separately. Determine the severity of the danger according to the magnitude of the impact of the fault;

(5) List the failure probability.

(6) List exclusions or controls

Dangerous measures. If the failure will cause injury or death, it is necessary to clarify to what extent safety facilities and precautionary measures decompose key components and key raw materials. This is another key issue that should be paid attention to and should be determined according to the purpose of hazard analysis. In general, when the analysis object has a certain failure rate, it can no longer be decomposed in detail. For example, the failure rate of smoke detectors commonly used in gas fire control systems can be obtained under general environmental conditions.It is not necessary to analyze its components, but if the failure rate of the detector is abnormal and the normal situation, you need to Further analyze the failure types, impacts and failure rates of various components to determine specific prevention and improvement measures.