Research on Risk Assessment Method and System Development of Small Ammonia Refrigeration Units

2019 ◽  
Author(s):  
Xiang Li ◽  
Weihua Wang ◽  
Weike Jing ◽  
Jin Shi ◽  
Fakun Zhuang
Keyword(s):  
Risk Assessment ◽  
Evaluation Method ◽  
System Development ◽  
Correction Method ◽  
Assessment Method ◽  
Scientific Basis ◽  
Assessment System ◽  
Assessment Model ◽  
Mitigation Measures ◽  
Risk Assessment Method

Abstract In recent years, ammonia leakage accidents occur frequently, which causes a great concern in China. Based on traditional risk analysis methods and the equipment characteristics, a risk evaluation method for small ammonia refrigeration units is proposed. The method includes a risk assessment model based on area division, a failure probability assessment method based on expert scoring system, a failure consequence assessment method based on regional population density and consequence mitigation measures, and a HAZOP risk correction method. Based on the proposed method, a risk assessment system of small ammonia refrigeration units is developed. This risk assessment method and system will provide a scientific basis to carry out the cold storage management in China.

scholarly journals A Dynamic Risk Assessment Method for Deep-Buried Tunnels Based on a Bayesian Network

Geofluids ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-14 ◽  
Author(s):  
Yan Wang ◽  
Jie Su ◽  
Sulei Zhang ◽  
Siyao Guo ◽  
Peng Zhang ◽  
...  
Keyword(s):  
Risk Assessment ◽  
Bayesian Network ◽  
Influencing Factors ◽  
Assessment Method ◽  
Assessment Model ◽  
Risk Level ◽  
Dynamic Risk ◽  
Risk Rating ◽  
Risk Assessment Method ◽  
Dynamic Risk Assessment

In view of the shortcomings in the risk assessment of deep-buried tunnels, a dynamic risk assessment method based on a Bayesian network is proposed. According to case statistics, a total of 12 specific risk rating factors are obtained and divided into three types: objective factors, subjective factors, and monitoring factors. The grading criteria of the risk rating factors are determined, and a dynamic risk rating system is established. A Bayesian network based on this system is constructed by expert knowledge and historical data. The nodes in the Bayesian network are in one-to-one correspondence with the three types of influencing factors, and the probability distribution is determined. Posterior probabilistic and sensitivity analyses are carried out, and the results show that the main influencing factors obtained by the two methods are basically the same. The constructed dynamic risk assessment model is most affected by the objective factor rating and monitoring factor rating, followed by the subjective factor rating. The dynamic risk rating is mainly affected by the surrounding rock level among the objective factors, construction management among the subjective factors, and arch crown convergence and side wall displacement among the monitoring factors. The dynamic risk assessment method based on the Bayesian network is applied to the No. 3 inclined shaft of the Humaling tunnel. According to the adjustment of the monitoring data and geological conditions, the dynamic risk rating probability of level I greatly decreased from 81.7% to 33.8%, the probability of level II significantly increased from 12.3% to 34.0%, and the probability of level III increased from 5.95% to 32.2%, which indicates that the risk level has risen sharply. The results show that this method can effectively predict the risk level during tunnel construction.

scholarly journals Study on Fire Risk Assessment Method by Considering Warehouse Characteristics

2020 ◽  
Vol 20 (2) ◽  
pp. 105-112
Author(s):  
Hayoung Kim ◽  
Dongho Rie
Keyword(s):  
Risk Assessment ◽  
Evaluation Method ◽  
Operation Time ◽  
Fire Risk ◽  
Assessment Method ◽  
Design Stage ◽  
Fire Hazards ◽  
Risk Assessment Method ◽  
Fire Risk Assessment ◽  
Fire Loads

Large spaces, such as warehouses where internal loads are stored, exhibit higher fire loads and faster fire growths than general fires. In addition, the volume of the internal load reduces the space required for the smoke to stay, thereby accelerating the decline in smoke height. To prevent fire hazards in such spaces, it is necessary to evaluate the fire risk during the design stage. However, it is difficult to evaluate various settings because the evaluation method using the existing computational fluid dynamics utilize considerable amount of time. In this study, an algorithm was developed to evaluate the internal loads by using formulas related to the existing fire risk assessment. The developed algorithm is designed to easily calculate the detection time of the detector, smoke fall time, and sprinkler operation time. This algorithm could be used to design an optimized fire protection system in the initial design stage.

scholarly journals Research on measuring device and quantifiable risk assessment method based on FMEA of escalator brake

2021 ◽  
Vol 13 (3) ◽  
pp. 168781402110019
Author(s):  
Haixia Ma ◽  
Zhongxing Li ◽  
Zhidong Wang ◽  
Ruijue Feng ◽  
Gang Li ◽  
...  
Keyword(s):  
Risk Assessment ◽  
Measurement Error ◽  
Failure Mode ◽  
Measurement Method ◽  
Assessment Method ◽  
Distance Measurement ◽  
Assessment System ◽  
Measuring Device ◽  
Risk Assessment Method ◽  
Braking Distance

To improve the accuracy of braking distance measurement and reduce the impact of human factors on brake risk assessment of escalators, a non-contact braking distance measuring device based on infrared ranging principle is designed. Futher, a quantifiable risk assessment method of brake based on failure mode and effects analysis (FMEA) is propose in this paper. Characteristics and trends of distance changes during emergency braking process of the escalator are theoretically analyzed. To extract, process, and recognize the distance change signals, and finally to realize accurate measurement of the braking distance, a high-speed infrared distance measurement technology is used. Influencing factors of the escalator brake performance are studied. The risk analysis method based on FMEA is used to analyze its failure mode, failure mechanism, and consequences of the failure. A risk index assessment system is constructed and quantified. The test results show that the measurement error of the device designed is 1.6%, which is 1/6 of the traditional measurement method. The repeated measurement error of the device is 1.4%, which is 1/7 of the traditional measurement method. Application results show that the quantifiable risk assessment method quantifies and assigns the risk level according to the weight, which effectively avoids the inconsistent results caused by human bias. The evaluation results are more scientific and reliable.

Risk Assessment of Reservoir by Fuzzy Comprehensive Evaluation Method Based on Information Entropy

2013 ◽  
Vol 438-439 ◽  
pp. 1612-1618
Author(s):  
Yong Jia Song ◽  
Cong Cong Jin ◽  
Xian Cai Zhang ◽  
Jing Li
Keyword(s):  
Risk Assessment ◽  
Information Entropy ◽  
Evaluation Method ◽  
Comprehensive Evaluation ◽  
Fuzzy Comprehensive Evaluation ◽  
Assessment Method ◽  
Assessment Model ◽  
Risk Level ◽  
Entropy Weight ◽  
Weighting Method

This paper proposes a new risk assessment model on account of the fuzziness and uncertainty of risk factors in the reservoir after earthquake. The paper adopts methods of information entropy and fuzzy mathematics to assess risk level of the model. After analyzing the statistical data of earthquake-damaged reservoirs, we present comprehensive weight composed of importance and improved entropy weight. Base on comprehensive weight, we can adopt membership function to establish single factor evaluation of the model. Moreover, we combine fuzzy weighting method to assess risk level of a reservoir after earthquake. The result shows that risk level of the reservoir is high-risk. The case study verifies the practicability and rationality of the risk assessment method. Therefore, the method could be applied in the emergency rescue and reinforcement for reservoir after earthquake.

scholarly journals Determining optimal risk assessment model in construction projects (Case study: steel plant construction project

2020 ◽  
Author(s):  
S Salajegheh ◽  
A Akhavan ◽  
A Hajihosseini
Keyword(s):  
Risk Assessment ◽  
Occupational Safety ◽  
Safety Management ◽  
Assessment Method ◽  
Ease Of Use ◽  
Assessment Model ◽  
Assessment Methodology ◽  
Decision Matrix ◽  
Risk Assessment Method ◽  
Risk Assessment Methodology

Introduction: Identifying occupational hazards and managing occupational safety and health risks has been the most important mission and responsibility of the health and safety management system in organizations and adopting coded plans to achieve this is the key to continuously improving this system and promoting it. The aim of the present study was to determine the optimal risk assessment methodology in development projects. Materials and Methods: This was a descriptive-analytic research In this research, using previous research studies and collecting expert opinions, the most important criteria for selecting a specific risk assessment methodology, and then using one of the three most-used techniques is an important activity in the steel making industry and risk assessment. Then, the decision matrix is based on the strengths and weaknesses of the models. The prioritization of these three methods is done using the hierarchical analysis decision method. Results: In this paper, five key factors, the degree of application in identifying hazards, usability in different stages of risk assessment, reliability, ease of use, and training needs and costs, are identified as the most important criteria for choosing a risk assessment technique and the FMEA method was considered as the best  Risk Assessment Method. Conclusion: FMEA methodhas been introduced with regard to its capabilities as an optimal risk assessment method for contruction projects.

Study on a Quantitative Risk Assessment Method of Primary Equipments Based on Power Grid Safety Analysis

2014 ◽  
Vol 541-542 ◽  
pp. 863-868
Author(s):  
Kun Ling Deng ◽  
Dan Dan Li ◽  
Ying Wang ◽  
Xiao Lei Cheng ◽  
Ming Li ◽  
...  
Keyword(s):  
Risk Assessment ◽  
Power Grid ◽  
Operation Mode ◽  
Safety Analysis ◽  
Assessment Method ◽  
Assessment Model ◽  
Quantitative Risk Assessment ◽  
Normal Operation ◽  
Risk Assessment Model ◽  
Risk Assessment Method

A quantitative risk assessment method of primary equipments based on power grid safety analysis is presented in this paper, and the risk assessment model of power grid primary equipments is established. On the basis of the calculated losses caused by various faults of N-1 and N-2 under the normal operation mode and the equipment maintenance mode, whether an equipment needs to be maintained is determined by comparing the size of the possible losses in two operation modes of a power grid. Then, the purpose of guiding the condition based maintenance of the power grid primary equipments is achieved. Finally, the presented risk assessment model of power grid primary equipments is applied to a certain practical power system.

scholarly journals Research on Privacy Security Risk Assessment Method of Mobile Commerce Based on Information Entropy and Markov

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Tao Zhang ◽  
Kun Zhao ◽  
Ming Yang ◽  
Tilei Gao ◽  
Wanyu Xie
Keyword(s):  
Risk Assessment ◽  
Information Entropy ◽  
Personal Information ◽  
Assessment Method ◽  
Mobile Commerce ◽  
Assessment Model ◽  
Security Risk ◽  
Potential Threat ◽  
Risk Assessment Method ◽  
Security Risk Assessment

To obtain precise personalized services in mobile commerce, the users have to disclose their personal information to the operator, which constitutes a potential threat to their privacy security. In this paper, a mobile commerce privacy security risk assessment model is established based on information entropy and Markov chain, and effective security risk measurement, and assessment method is put forward. Our method can provide accurate and quantitative results in assessing privacy disclosure risk to guide the users’ selection of safe mobile commerce applications and protect their privacy security.

scholarly journals Risk Assessment Method for Cable System Construction of Long-Span Suspension Bridge Based on Cloud Model

2019 ◽  
Vol 2019 ◽  
pp. 1-9
Author(s):  
Zhifang Lu ◽  
Chaofan Wei ◽  
Muyu Liu ◽  
Xiaoguang Deng
Keyword(s):  
Risk Assessment ◽  
Cloud Model ◽  
Suspension Bridge ◽  
Assessment Method ◽  
Assessment Model ◽  
Suspension Bridges ◽  
System Construction ◽  
Cable System ◽  
Long Span ◽  
Risk Assessment Method

Cable system construction is one of the most risky construction stages of long-span suspension bridges, and a reliable risk assessment is an important means to ensure the construction safety. This study proposes a risk assessment method for cable system construction of suspension bridges based on the cloud model, which can combine randomness and fuzziness of risk information effectively. First, a multilevel evaluation index system is built by disassembling the process of cable system construction. Next, the index weights are calculated by the uncertain analytic hierarchy process (AHP). Then, according to the cloud model, a risk assessment model for cable system construction of the suspension bridge is established by realizing the mutual transformation between qualitative language and quantified data. Finally, an illustrative example concerning the risk of cable system construction of Wuhan Yang-Si-Gang Yangtze River Bridge is provided to demonstrate the feasibility and objectivity of the proposed method.

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