Application of a Bayesian model for the quantification of the European methodology for qualification of non-destructive testing

The European methodology for qualification of non-destructive testing is a well-established approach adopted by nuclear utilities in many European countries. According to this methodology, qualification is based on a combination of technical justification and practical trials. The methodology is qualitative in nature, and it does not give explicit guidance on how the evidence from the technical justification and results from trials should be weighted. A Bayesian model for the quantification process was presented in a previous paper, proposing a way to combine the “soft” evidence contained in a technical justification with the “hard” evidence obtained from practical trials.This paper describes the results of a pilot study in which such a Bayesian model was applied to two realistic Qualification Dossiers by experienced NDT qualification specialists. At the end of the study, recommendations were made and a set of guidelines was developed for the application of the Bayesian model.     

国内首台EPR型核电常规岛除氧器水箱焊接技术综述

本文针对国产首台EPR型核电常规岛除氧器水箱引进技术特点,与国内常规火电除氧器进行比较和分析,制定了切实有效的焊接工艺方案,并顺利通过焊接工艺评定的验证,该技术现已成功获得TUV公司和ALSTOM公司的认可并应用于产品制造,成为继掌握AP1000型引进技术之后,又顺利产成一代具有欧洲特色的核电常规岛产品。     

Methodology for optimization of distributed biomass resources evaluation,management and final energy use

A methodology has been developed to assess optimal management and energy use of distributed biomass resources, where logistics is a main factor but other features must be also considered: biomass resources properties (quantity, quality, seasonality & availability), plant size effect, available technologies for power, heat and solid biofuels generation, CO₂ emissions balance and quantification of potential biofuel consumers.This methodology provides a quantification and characterization of biomass resources, a list of optimal locations from logistic point of view and the necessary data to perform detailed technical, economic and environmental analysis of the different biomass energy use options. It has been applied to three districts of the Valencian region in Spain and main results and conclusions are also included in this paper.     

Risk aversion and institutional information disclosure on the European carbon market: A case-study of the 2006 compliance event

This article evaluates the impact of the 2006 compliance event on changes in investors’ risk aversion on the European carbon market using the newly available option prices dataset. Thus, we aim at capturing the specific event that occurred on April 2007 as the European Commission disclosed the 2006 verified emissions data. Following the methodology existing for stock indices, we recover empirically risk aversion adjustments on the period 2006–2007 by estimating first the risk-neutral distribution from option prices and second the actual distribution from futures on the European Climate Exchange. Our results show evidence of a dramatic change in the market perception of risk around the 2006 yearly compliance event that has not been assessed yet.     

Hydrogen transportation systems: Elements of risk analysis

This paper describes the methodology and the results obtained in the framework of the NEEDS (New Energy Externalities Developments for Sustainability) European project, while evaluating externalities due to accidental situations. In particular it focuses on the results obtained from a risk assessment of hydrogen transportation technologies. The quantification of risk as an additional source of externality to the cost of transporting hydrogen was obtained with the support of a commercial numerical simulation software that was specifically designed to deal with hazards in process industry environment. A number of scenarios and site dependencies have been taken into account in order to assess the risk associated with different transportation means, under several accidental conditions (e.g., kind of rupture and weather conditions). Results were compared with social acceptability limits of risk set by some countries.     

Predicting the technical impacts of high levels of small-scale embedded generators on low-voltage networks

The anticipated high penetrations of small-scale embedded generators (SSEGs) on public low-voltage (LV) distribution networks are likely to present distribution network operators (DNOs) with a number of technical impacts relating to power quality, distribution system efficiency and potential equipment overloads. Impact studies need to be performed using suitable case study networks in order to evaluate the effects of SSEGs on LV distribution networks and quantify allowable SSEG penetration levels. The aim is to propose a methodology for predicting the technical impacts of SSEGs on LV networks without the need for developing a detailed computerbased model of the power system and simulating a range of operating scenarios. This methodology is drawn from an analysis of the key electrical characteristics that determine the response of LV networks to the addition of SSEGs, focusing on the following technical aspects: (i) voltage regulation, (ii) voltage rise, (iii) voltage unbalance, (iv) cable and transformer thermal limits and (v) network losses. The analysis is carried out on a UK generic and a European generic LV network and simulation results for both networks are presented and discussed. The proposed methodology is then applied to an existing public UK LV network operated by E.ON UK Central Networks, indicating a good agreement between predicted and simulation results.     

锅炉钢架柱底板制造工艺分析和改进

大型电站锅炉钢架的柱底板是重要结构件，技术要求高，制造中采用多种工艺改进措施，加强质量检查，取得很好技术和经济效果。     

Development of regulations,codes and standards on composite tanks for on-board gaseous hydrogen storage

Composite tanks for on-board gaseous hydrogen storage is one of key parts of the hydrogen fuel cell vehicle. Regulations, codes and standards (RC & S) are conducive to overcoming technological barriers to commercialization. This paper reviews the development of RC & S on composite tanks for on-board gaseous hydrogen storage and addresses their highlights on technical requirements. First, an overview of RC & S for composite tanks is introduced. Then, a comparative study on technical requirements of RC & S including service conditions, design requirements, materials, manufacture, qualification tests and management is presented. Finally, several major differences in RC & S, i.e., tank classification in ISO 19881 and penetration test method are discussed. Some issues for further research, such as initial burst pressure, material hydrogen compatibility and periodic inspection methods are proposed.     

Micro-roll forming of stainless steel bipolar plates for fuel cells

Stainless steel bipolar plates for use in proton exchange membrane (PEM) fuel cells have been identified as a lighter and cheaper alternative to graphite plates. Current manufacturing of metal bipolar plates by hydroforming or micro-stamping leads to excessive stretching of the material and therefore limits the channel depths that can be formed. Low channel depths for the bipolar plates will result in low overall fuel cell efficiency. In comparison, the bending-dominated deformation mode present in roll forming provides the potential to form metal bipolar plates with less thinning and to greater channel depths. In this work, the roll forming process is employed for the first time to form thin stainless steel sheets to micro-scale channel sections of the kind required for bipolar plates. This paper describes the process and machine design as well as the establishment of the forming methodology. Experimental trials are performed and the final part quality is evaluated in terms of material thinning, longitudinal bow and cross-sectional shape. The process was numerically analysed to understand the causes of the forming problems and shape defects observed in the experimental trials. The results of this work show that roll forming of micro-scale corrugated bipolar sheets is feasible. Furthermore, the findings provide a summary of both the practical difficulties and the possible advantages of using micro-roll forming to manufacture improved thin metal micro-corrugations for bipolar plates.     

无人机用于输电线路巡检的作业流程及应用

相比人工巡检模式,采用无人机巡检将大幅提高电网运检效率。但无人机巡检作业目前仍处于试验阶段,缺乏统一、规范的巡检作业流程。根据无人机在南方电网贵州某超高压输变电工程的实际巡检作业应用,提出了一套科学合理的巡检作业流程,并对该套无人机巡检作业流程的高效性进行实地检验。试验结果表明:无人机巡检不仅可有效降低企业人工投入成本,而且能克服由于复杂地形、极端天气等人为不可控因素而无法进行巡检作业的情况,极大地提高了巡检作业范围和效率。     

核电站1E级变压器鉴定试验方法研究

针对核电站1E级变压器的鉴定方法进行了说明,建立了1E级变压器的试验鉴定流程。同时,对影响鉴定结果的试验顺序和试验中对试验结果可能造成偏差的关键点进行了阐述,指出在变压器鉴定试验过程中常出现的错误方法,对这些方法进行纠正。     

RIMAP demonstration project. Risk-based life management of piping system in power plant Heilbronn

In the framework of EU project RIMAP [Risk Based Inspection and Maintenance Procedures for European Industry (2000)] a new European Guideline for optimized risk based maintenance and inspection planning of industrial plants (RBLM, Risk Based Life Management) is being developed. The RIMAP project consists of the three clustered projects

• •development (RTD)
• •demonstration (DEMO)
• •thematic network (TN)

Current work and future, planned work in RIMAP demonstration project on applications of the RIMAP methodology in power plants are presented briefly in the first part of the paper. Also presented in the paper are the results of a preliminary analysis of piping system in power plant Heilbronn using the concept of risk-based monitoring as part of overall concept of risk-based life management. Shortly the following issues are discussed in the paper

• •identification of critical components
• •application of a multilevel risk analysis (…from ‘screening’ to ‘detailed analysis’)
• •determination of PoF (Probability of Failure)
• •determination of CoF (Consequence of Failure)
• •optimation of inspection and maintenance plan

From our experience with the application of the RIMAP methodology the following conclusions can be drawn: The use of risk-based methods in inspection and maintenance of piping systems in power plants gives transparency to the decision making process and gives an optimized maintenance policy based on current state of the components. The results of the work clearly show the power of the proposed method for concentration on critical items: out of 64 monitored components 5 were selected for intermediate analysis and only 1 for the detailed analysis (probabilistic high temperature fracture mechanics).     

Cost optimal reliability based inspection and replacement planning of piping subjected to CO2 corrosion

A methodology for cost optimal reliability based inspection and replacement planning of piping subjected to CO₂ corrosion is described. Both initial (design phase) and in-service planning are dealt with. The methodology is based on the application of methods for structural reliability analysis within the framework of Bayesian decision theory. The planning problem is formulated as an optimization problem where the expected lifetime costs are minimized with a constraint on the minimum acceptable reliability level. The optimization parameters are the number of inspections in the expected lifetime, the inspection times and methods. In the design phase the nominal design wall thickness is also treated as an optimization parameter. The most important benefits gained through the application of the methodology are consistent evaluation of the consequences of different inspection and replacement plans, consistent incorporation and handling of uncertainties, and consistent updating of inspection and replacement plans based on inspection results. The latter is achieved through application of Bayesian statistics for updating in combination with structural reliability methods.     

A review of European standards for pellet quality

The quality of pellets is directly related to their physical, chemical, and mechanical properties. It affects the emissions resulting from their combustion and also their use in stoves and boilers. Certain European countries have developed standards specifying control parameters and guidelines with a view to guaranteeing the effective and environmentally-friendly combustion of pellets. This paper presents a comparative study of regulations and standards created by government authorities in Austria, Sweden, Germany, Italy, and France. Also considered are the guidelines of the European Standard Committee CEN/TC 335 for densified biomass fuels. The comparison of these standards provides evidence of significant differences in the quality parameters and guidelines for the manufacture and use of pellets in Europe. The results obtained could be used as a technical reference for all issues related to the production, sale and research on pellets.     

Proposal for territorial distribution of the EU 2020 political renewable energy goal

This article first analyses the situation of indicators related to renewable energies in the reference year (2005) used by the European Union (EU) for its goal of a 20% share of energy from renewable sources in the gross final consumption of energy in 2020. Nonlinear distribution of dynamic targets is suggested for increasing the energy from renewable sources in gross final consumption of energy. This methodology is then applied to European Union member countries, the NUTS0 territorial aggregation level according to the EUROSTAT Nomenclature of Territorial Units for Statistics (NUTS), in the year 2020. Weighting was done based on share of energy from non-renewable sources in gross final consumption of energy, energy from non-renewable sources per capita, energy from non-renewable sources per GDP and GDP per capita in the EU-27 scenario. Finally, a multicriteria formula was applied to weight the variables used in this study.     

NDT performance demonstration in Spain

The experience obtained from the in-service inspection of reactor pressure vessels (RPV) of Spanish nuclear power plants and the participation in several international programs, such as PISC, has shown the need for a performance demonstration, not only for the ultrasonic inspection techniques of RPV, but also for other ISI non-destructive techniques as in the case of eddy current inspection of steam generator tubing.

Section XI of the ASME Code, which is applied in Spain for ISI, has incorporated recently the Appendix VIII for performance demonstration of ultrasonic inspection techniques.

As a direct consequence of this, a Spanish project for performance demonstration of ultrasonic inspection techniques has been launched recently, which includes the manufacturing of full-scale mock-ups of nozzle to vessel welds, reactor vessel welds, wrought austenitic piping welds and ferritic piping welds of PWR and BWR nuclear power plants from different suppliers. This considerable technical effort will let the different Spanish organizations which are part of the project to participate and colaborate with similar international projects and in particular with a European initiative for performance demonstration.     

Towards an improved architectural quality of building integrated solar thermal systems (BIST)

Architectural integration is a major issue in the development and spreading of solar thermal technologies. Yet the architectural quality of most existing building integrated solar thermal systems (BIST) is quite poor, which often discourages potential new users.In this paper, the results of a large web survey on architectural quality, addressed to more than 170 European architects and other building professionals are presented and commented. Integration criteria and design guidelines established and confirmed through the analysis of these results are proposed.Subsequently, a novel methodology to design future solar thermal collectors systems suited to building integration is described, showing a new range of design possibilities. The methodology focuses on the essential teamwork between architects and engineers to ensure both energy efficiency and architectural integrability, while playing with the formal characteristics of the collectors (size, shape, colour, etc.).Finally a practical example of such a design process conducted within the European project SOLABS is given; the resulting collector is described, and integration simulations are presented.     

单管供热系统热力失调研究

本文研究了供热系统在单纯改变供水温度和供水量,以及室外空气温度偏离设计温度而采用质调节或量调节方式供热时出现的热力失调现象,总结失调规律,分析各种参数变化对室内热力失调规律的影响,本文的研究为提高供热质量提供了参考。