不停产高效设备故障检测系统开发研究

目前设备设施,生产工艺故障及隐患的监督检查方法仍然停留在常规的、传统方式上。技术人员开展了不停产高效设备故障检测系统开发研究,设计了故障检测系统网络管理与现场单机管理两种方式,可使用同一套软件管理系统。现场图象处理机可以在分析、确认设备存在严重故障情况下．现场打印分析报告,并及时通知所在单位,排除故障。     

南方地区热泵供暖空调系统的现状与构建方式探讨

针对我国南方夏热冬冷地区建筑空调的特点,指出了单一热源的热泵系统存在的问题,综述了冷却塔辅助散热的混合式热泵系统、冻土蓄冷混合式热泵系统以及能源塔热泵系统等复合热源系统的研究及应用情况。混合式热泵系统的性能较单一形式热泵系统有所改善,但仍存在一些问题亟待解决。为进一步提高热泵系统的节能性和可靠性,基于"用、补、蓄"的思想,本文提出一种季节性蓄存环境空气冷能的混合热泵系统,并对该系统进行了简单的数值模拟,探讨了其在夏热冬冷地区应用的可行性。     

高温热泵技术在工业制冷领域的应用

通过总结国内外高温热泵技术的研究现状及研究成果,提出高温热泵的研究重点是新型环保工质的选择和系统性能效率的提高;通过对一些高温热泵系统方面国内外最新的研究进展及离心式高温热泵机组的发展现状分析,指出高温热泵技术在油田原油加热、化工工艺、污水热回收、海水淡化以及木材食品干燥方面有着广泛的应用前景及良好的节能效果.提出了高温热泵的发展方向及趋势.     

热泵空调换热器水侧污垢故障的诊断

提出了换热器水侧污垢的理论模型;利用减小水流量的方法来模拟污垢故障,当故障发生时,吸排气压力会上升,这相当于热泵的制热系数降低了;神经网络由于具有模拟任何连续非线性函数的能力和利用样本学习的能力,已被用于本系统的故障诊断中;采用感知器学习算法对热泵空调换热器水侧污垢故障进行诊断.     

洛阳市地下水源热泵空调系统节能经济性研究

为了准确评估洛阳市地下水源热泵空调系统节能性及经济性,基于洛阳市典型工程项目的现场调研数据,建立地下水源热泵中央空调系统节能性及经济性评价的数学模型,并依据初投资、运行费用、标准煤耗量等评价指标对传统中央空调系统和地下水源热泵空调系统的能耗及经济性进行了比较分析。研究表明,所提出的单位空调面积评价方法是适用于地下水源热泵空调系统的运行能耗和经济性的科学评价方法。     

当前地源热泵应用中的若干问题探讨

地源热泵(GSHP)是一种既可以供热又可以制冷的高效节能环保型空调系统.关于地源热泵的分类问题还存在很多不同的看法和争议,据此笔者提出自己的一些观点,并指出常规认识中的一些误区.同时对目前大家比较关注的应用较多的土壤源热泵、地热水水源热泵、地下水(深井水)水源热泵的系统形式及分类等情况作了一简单介绍. 此外,在简单介绍水环热泵系统原理的基础上,对一些在使用中比较模糊和容易混淆的几个概念进行了区别和分析,得出的结论是:通常所认为的"水环热泵属于水源热泵"的看法是不正确的,水环热泵事实上应该是一种空气源热泵;此外,"水源热泵是一种水--空气热泵"的说法也不确切,事实上,水源热泵可以采用水--空气热泵形式,也可以采用水--水热泵形式.     

热泵型空调系统分类刍议

热泵是一种既可以供热又可以制冷的高效节能环保型空调系统.针对热泵型空调系统的分类问题还存在很多不同的看法和争议的现状,笔者提出自己的一些观点,并指出常规认识中的一些误区.此外,在简单介绍水环热泵系统原理的基础上,对一些在使用中比较模糊和容易混淆的几个概念进行了区别和分析,并得出水环热泵事实上应该是一种空气源热泵的结论.     

宾馆建筑热泵系统节能改造实践与研究

对杭州某宾馆热泵系统的节能改造方案作了可行性分析;对节能计算标准的确定等方面作了研究;就热泵系统节能改造工程提出了一些建议。     

工业加热用高温水源热泵现场运行及经济性分析

为将热泵技术应用扩展至工业加热领域,通过调整压缩机设计、优化热泵流程及系统控制方法,设计了高温热泵并现场测试了其在原油加热场合的应用。研究表明:优化设计的高温热泵系统可提供95℃热水,其1 700 kW加热量可满足工业加热需求;运行中热泵系统制热COP介于3.8到4.8;热泵系统运行过程中压缩机排气温度低于100℃,同时电机温度低于85℃。对高温热泵系统及燃油加热炉的经济性分析显示,热泵系统能耗仅为燃油加热量的44.7%。     

美国艾默生公司压缩机应用技术讲座：第二十一讲 谷轮“低温强热涡旋”在热泵式空调器中的应用（1）

本文指出了常规的空气源热泵系统在低温环境使用时的一些根本性问题.介绍了谷轮"低温强热涡旋"压缩机技术在热泵式空调中的应用,从理论上分析了采用过冷器和闪发器作为经济器来实现涡旋中间喷射热泵系统的特点及对制热性能的改善.介绍了谷轮专利的单热型低温强热涡旋热泵系统,通过实验表明,该系统明显改善了低温环境下的制热能力,从现场测试中证明单热型低温强热涡旋热泵系统在经济性和可靠性上得到显著提高.在热泵式空调器中使用带中问喷射的"低温强热涡旋"技术是未来技术发展的方向.     

基于多信号模型的舰船柴油机测试性研究

从设计着手,全系统全寿命周期考虑装备的测试诊断问题是避免重大事故发生和降低维修保障费用的有效手段.在充分研究舰船柴油机测试性特点及现状的基础上,引入多信号模型对舰船柴油机的润滑系统进行了测试性建模与分析,对其测试性设计提出了改进措施,能够全面地检测与隔离故障,为科学合理的制定测试方案提供了方法指导.     

A Bayesian analysis of beta testing

In this article, we define a model for fault detection during the beta testing phase of a software design project. Given sampled data, we illustrate how to estimate the failure rate and the number of faults in the software using Bayesian statistical methods with various different prior distributions. Secondly, given a suitable cost function, we also show how to optimize the duration of a further test period for each one of the prior distribution structures considered. Michael Wiper acknowledges assistance from the Spanish Ministry of Science and Technology via the project BEC2000-0167 and support from projects SEJ2004-03303 and 06/HSE/0181/2004     

An EFSM-Based Test Data Generation Approach in Model-Based Testing

Testing is an integral part of software development. Current fast-paced system developments have rendered traditional testing techniques obsolete. Therefore, automated testing techniques are needed to adapt to such system developments speed. Model-based testing (MBT) is a technique that uses system models to generate and execute test cases automatically. It was identified that the test data generation (TDG) in many existing model-based test case generation (MB-TCG) approaches were still manual. An automatic and effective TDG can further reduce testing cost while detecting more faults. This study proposes an automated TDG approach in MB-TCG using the extended finite state machine model (EFSM). The proposed approach integrates MBT with combinatorial testing. The information available in an EFSM model and the boundary value analysis strategy are used to automate the domain input classifications which were done manually by the existing approach. The results showed that the proposed approach was able to detect 6.62 percent more faults than the conventional MB-TCG but at the same time generated 43 more tests. The proposed approach effectively detects faults, but a further treatment to the generated tests such as test case prioritization should be done to increase the effectiveness and efficiency of testing.     

Fault detection in CMOS circuits by consumption measurement

Some testing problems in CMOS circuits are presented, including stuck-open and stuck-on faults, bridging faults, and excessive leakage in dynamic CMOS circuits. It is shown that the current consumption of a faulty CMOS circuit is several orders of magnitude greater than that of the fault-free circuit: hence, consumption measurement may be a suitable way of testing. Test by consumption measurement provides improved controllability and observability of some faults in comparison with the logic test     

Quantitative demonstration and cost considerations of a software fault removal methodology

This paper presents a demonstration of a methodology for fault removal during software development. The methodology encompasses the entire development history, from system and software requirements generation to system test. Thus it considers not only the faults during software testing after formal configuration controls have been invoked, but also the faults discovered prior to that phase: during system and software requirements generation, preliminary design, detailed design and code and unit testing. The agents for fault discovery used in verification and validation are called activities, techniques and tools (AT & Ts) in this paper, each having a certain maximum potential or capability for fault discovery. The AT & Ts considered include the usual specification review activities, and also certain tools not normally applied in ‘standard’ software development, such as automated requirements aids. Application of the methodology yields numbers of residual faults as of each phase of development, including those remaining to be discovered during operations and maintenance. Some previous experience and data on residual faults correspond to these results, indicating that the methodology and choice of parameters are reasonable. The methodology also allows one to calculate a relative loss due to delay in fault discovery, which, as is well known, rises rapidly when faults are not discovered during the phase in which they are generated.     

A parallel built-in self-diagnostic method for nontraditional faults of embedded memory arrays

In this paper, we propose a built-in self-diagnostic march-based algorithm that identifies faulty memory cells based on a recently introduced nontraditional fault model. It is developed based on the DiagRSMarch algorithm, which is a diagnostic algorithm to identify traditional faults for embedded memory arrays. A minimal set of additional operations is added to DiagRSMarch for identifying the nontraditional faults without affecting the diagnostic coverage of the traditional faults. The embedded memory arrays are accessed using a bidirectional serial interfacing architecture which minimizes the routing overhead introduced by the diagnosis hardware. Using the concepts of the bidirectional interfacing technique, parallel testing, and redundant-tolerant operations, the diagnostic process can be accomplished efficiently at-speed with minimal hardware overhead.     

A Blasting SourcesBased Approach to Inspection of Faults in Dam

An approach to inspection of incipient faults in dams by nondestructive testing is a so far emerging inspection technology in the world. In this paper, inspection principles, system integrity and key items for the new blasting sourcebased technology for inspection of incipient faults in dams, different from common nondestructive testing, are presented, following briefing experiences in dam inspection by elastic wave CT in recent years. Specific procedures and goals for further spreading and application as well as conclusion are introduced finally.     

倒频谱在压缩机故障诊断中的应用

针对压缩机故障的特点，利用在线检测系统对在工业运行中的压缩机进行检测，对测得的振动信号进行了频谱分析，结合谱图，详细介绍了倒频谱在故障诊断中的应用。实践证明了，倒频谱在检测周期信号和识别边频上具有独特的功能。     

Testability enhancement of a basic set of CMOS cells

Testing should be evaluated as the ability of the test patterns to cover realistic faults, and high quality IC products demand high quality testing. We use a test strategy based on physical design for testability (to discover both open and short faults, which are difficult or even impossible to detect). Consequentially, layout level design for testability (LLDFT) rules have been developed, which prevent the faults, or at least reduce the chance of their appearing. The main purpose of this work is to apply a practical set of LLDFT rules to the library cells designed by the Centre Nacional de Microelectrònica (CNM) and obtain a highly testable cell library. The main results of the application of the LLDFT rules (area overheads and performance degradation) are summarized and the results are significant since IC design is highly repetitive; a small effort to improve cell layout can bring about great improvement in design.     

Economic analysis of software release problems with warranty cost and reliability requirement

We discuss optimal software release problems which consider both a present value and a warranty period (in the operational phase) during which the developer has to pay the cost for fixing any faults detected. It is very important with respect to software development management that we solve an optimal software testing time by integrating the total expected testing cost and the reliability requirement. We apply a nonhomogeneous Poisson process model to the formulation of a software cost model and analyze three typical cases of the cost model. Moreover, we derive several optimal release polices. Finally, numerical examples are shown to illustrate the results of the optimal policies.