安全评价预先危险性分析ppt课件.ppt

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预先危险性分析
Preliminary Hazard Analysis
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预先危险性分析Preliminary Hazard Analysis
PHA 的基本含义
What is preliminary hazard analysis?
危险识别Hazard identification
危险等级的确定 hazards Rank
危险控制hazard controls
PHA的程序及表格编制PHA procedure
PHA实例分析 use of PHA
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第一节 PHA的基本含义
预先危险性分析（Preliminary Hazard Analysis 缩写PHA）是一种定性分析评价系统内危险因素和危险程度的方法。是指一个系统或子系统（包括设计、施工、生产之前，或技术改造之后，即制定操作规程和使用新工艺等情况之后）运转活动之前，对系统存在的危险类别、出现条件、可能造成事故的后果进行客观的概略分析。
目的：防止操作人员直接接触对人体有害的原材料、半成品、成品和生成废气物，防止使用危险性工艺、装置、工具和采用不安全的技术路线。如故必须使用时，也应从设备上或工艺上采取安全措施，以保证这些危险因素不致发展成为事故。
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Preliminary hazard analysis (PHA) is a semi-quantitative analysis that is performed to:
1. Identify all potential hazards and accidental events that may lead to an accident
2. Rank the identified accidental events according to their severity
3. Identify required hazard controls and follow-up actions Several variants of PHA are used, and sometimes under different names like
Preliminary Hazard Analysis
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1. As an initial risk study in an early stage of a project (., of a new plant).
Accidents are mainly caused by release of energy. The PHA identifies where energy may be released and which accidental events that may occur, and gives a rough estimate of the severity of each accidental event. The PHA results are used to
(i) compare main concepts,
(ii) to focus on important risk issues,
(iii) and as input to more detailed risk analyses.
Preliminary Hazard Analysis
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2. As an initial step of a detailed risk analysis of a system concept or an existing system.
The purpose of the PHA is then to identify those accidental events that should be subject to a further, and more detailed risk analysis.
3. As a complete risk analysis of a rather simple system.
Whether or not a PHA will be a sufficient analysis depends both on the complexity of the system and the objectives of the analysis.
Preliminary Hazard Analysis
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PHA的研究内容：
识别危险的设备、零部件，并分析其发生的可能性条件；
分析系统中各子系统、各元件的交接面及其相互关系与影响；