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INTRODUCTION Waterjet cleaning technology is mainly achieved by an erosion process of high pressure water to re-move coating materials.Louis and Schikorr(1982)identified deposits removed by high-speed waterjet cleaning as rust,oil,rubber,organics,etc.,and inves-tigated the relationship between the properties of the deposits and substrata.Summers(1982)investigated the correlation between the standoff distance,pres-sure and cleaning effectiveness.Saunders and Barton(1986)investigated the r… 相似文献
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王寒栋 《深圳职业技术学院学报》2004,3(3):20-22
在不同运行条件下对某变频冷冻水泵的性能参数进行了测试，获得了不同转速下该变频冷冻水泵机组的总效率(全效率)、变频器效率、电机和水泵的综合效率、变频冷冻水泵的水力效率比和容积效率比，总结得出了该变频冷冻水泵各效率随转速变化的规律。同时指出，在计算采用压差控制的变频冷冻水泵的能耗时，不应将变频冷冻水泵的总效率当作常数，不同运行控制方式对变频冷冻水泵效率有着不同的影响。 相似文献
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俞希伟江吉彬黄旭 《福建工程学院学报》2020,(6):564-569
设计了基于新能源汽车减速器零部件切削加工工艺智能决策系统。工艺数据库采用C/ S 体系架构,决策系统包括用户、基础信息、工艺参数三个管理模块。将实例和规则推理相结合搭建专家系统,建立基于混合推理技术的新能源汽车减速器切削加工工艺智能决策系统,定义加工属性优先级,进行切削工艺参数混合推理及优化匹配,自主决策,寻找最优工艺参数。在新能源汽车减速器生产工艺中进行具体验证,结果表明,基于C/ S 架构的减速器切削加工工艺智能决策系统,能够解决新能源汽车减速器生产加工工艺数据的合理存储和有效利用问题,大幅提升工艺决策效率和准确性。 相似文献
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Decomposition of dimethyl sulfide （DMS） in air was investigated experimentally by using a wire-cylinder dielectric barrier discharge （DBD） reactor at room temperature and atmospheric pressure. A new type of high pulse voltage source with a thyratron switch and a Blumlein pulse-forming network （BPFN） was adopted in our experiments. The maximum power output of the pulse voltage source and the maximum peak voltage were 1 kW and 100 kV, respectively. The important parameters affecting odor decomposition, including peak voltage, pulse frequency, gas flow rate, initial concentration, and humidity, which influenced the removal efficiency, were investigated. The results showed that DMS could be treated effectively and almost a 100% removal efficiency was achieved at the conditions with an initial concentration of 832 mg/m3 and a gas flow rate of 1000 ml/min. Humidity boosts the removal efficiency and improves the energy yield （EY） greatly. The EY of 832 mg/m3 DMS was 2.87 mg/kJ when the relative humidity was above 30%. In the case of DMS removal, the ozone and nitrogen oxides were observed in the exhaust gas. The carbon and sulfur elements of DMS were mainly converted to carbon dioxide, carbon monoxide and sulfur dioxide. Moreover, sulfur was discovered in the reactor. According to the results, the optimization design for the reactor and the matching of high pulse voltage source can be reckoned. 相似文献
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Xue-jun ZHANG Ke-qing ZHENG Ling-shi WANG Wei WANG Min JIANG Sheng-ying ZHAO 《浙江大学学报(A卷英文版)》2013,14(8):583-588
In this paper, a novel system using direct contact heat transfer between air and water solution was proposed to generate ice slurry. The heat transfer process and the system performance were studied; energy efficiency coefficients of 0.038, 0.053, and 0.064 were obtained using different solutions. An empirical relationship between the volumetric heat transfer coefficient Uv and the main parameters was obtained by fitting the experimental data. The Uv calculated from the empirical formula agreed with the experimental Uv quite well with a relative error of less than 15%. Based on the empirical formula, a laboratory-scale direct contact ice slurry generator was then constructed, with practical application in mind. If the air flow rate is fixed at 200 m3/h, the ice production rate will be 0.091 kg/min. The experimental results also showed that the cold energy consumption of the air compressor accounted for more than half of the total amount. To improve the system energy efficiency coefficient, it is necessary to increase the air pipes insulation and the solution＇s thermal capacity, and also it is appropriate to utilize the free cold energy of liquefied natural gas （LNG）. 相似文献
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Eyad Al-Falah Abdul-Aziz Al-Shuaib Hisham Ettouney Hisham El-Dessouky 《European Journal of Engineering Education》2001,26(4):407-418
Across the globe and since the dawn of civilization, fresh water resources have been a major economic, environmental and political issue that affect human welfare and progress. Today, the desalination industry is experiencing rapid growth across the globe; unfortunately, the industry lacks several key elements that should make this expansion more efficient, more profitable to the owner, less expensive to the consumer and with limited impact on the environment. These elements include development of codes and standards for various desalination activities and having integral training programmes for qualifying the manpower. This study focuses on evaluating the training programme adopted since 1994 in the Doha West desalination and power plant. Further development of the plant manpower is achieved through short course training on various topics related to design, operation and maintenance of desalination and power plants. Evaluation of the training programme is presented in terms of various operating parameters, which include plant availability, production efficiency, performance ratio, specific manpower and specific consumption of cleaning acid and balls. Results show drastic enhancement in plant performance, where availability increased to 80% and production efficiency is close to 100%. Also, the plant performance ratio remains at values close to clean operation for more than half of the operating time. The specific manpower shows continuous decline because of the increase in the production efficiency and elimination of unnecessary overhead costs. Operation policy focused on increasing the use of on-line ball cleaning and reducing the frequency of acid cleaning. This is advantageous, since acid cleaning promotes metal corrosion, while on-line ball cleaning has negligible effect on the integrity of the preheater tubes. 相似文献
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为提高电动汽车能量利用率、改善车辆制动效果,依照制动踏板的不同工作状态,设计了一种并联制动控制策略。在制动踏板踩下的复合制动工况,按照相关制动法规对机械制动和再生制动进行合理分配;在滑行制动工况,以能量回收效率为目标函数,运用遗传算法优化电机在不同转速下的最佳制动转矩。分别在典型道路工况和常规制动工况下对该策略进行实车测试,结果表明:在中国轻型汽车行驶工况(CLTC-P)下,该策略的节能贡献度可达25.93%,在滑行制动工况能量回收效率较原车提升64.07%,车辆制动距离也有明显缩减。 相似文献
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A leak detection method based on Bayesian theory and Fisher’s law was developed for water distribution systems. A hydraulic model was associated with the parameters of leaks (location, extent). The randomness of parameter values was quantified by probability density function and updated by Bayesian theory. Values of the parameters were estimated based on Fisher’s law. The amount of leaks was estimated by back propagation neural network. Based on flow characteristics in water distribution systems, the location of leaks can be estimated. The effectiveness of the proposed method was illustrated by simulated leak data of node pressure head and flow rate of pipelines in a test pipe network, and the leaks were spotted accurately and renovated on time. 相似文献
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针对云南曲靖卷烟厂使用烟末振动筛过程中出现筛分效率低、电能消耗大的问题,对直线振动筛的工作参数进行优化改进。通过对物料的力学分析得出影响透筛率的工作参数为激振力大小、方向和频率。每组变量设计3个实验参数,在Adams中建立参数化模型,采用仿真分析模拟废烟支和烟末在每组参数下的筛分过程。分析27组实验结果得出每组参数对透筛率的具体影响,根据生产实际选择合适的参数。优化后的工作参数相比原来节约能源35%以上,对M5型卷烟机的自动回收系统推广具有指导意义。 相似文献
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复合型空调清洗剂的研制 总被引：1，自引：0，他引：1
对复合型空调清洗剂进行了实验研究,结果表明,以非离子表面活性剂OP-10为主要表面活性剂成分,并通过添加助洗剂,复合阴离子表面活性剂十二烷基苯磺酸钠和十二烷基硫酸钠所配制的清洗剂性能最好。最佳配方（以质量分数表示）是：OP-10为9.0%,十二烷基苯磺酸钠2.0%,十二烷基硫酸钠1.0%,无水乙醇4.0%,异丙醇4.0%,三乙醇胺4.0%,焦磷酸钠0.3%,乙二胺四乙酸二钠0.7%,无水碳酸钠2.0%,碳酸氢钠2.0%,氯化钠2.0%,去离子水69.0%。这种配方配制的清洗剂清洗率达到99.91,pH值为8~9,静态绝缘性高达0.9MΩ,具有清洗性能优异、溶液稳定性好、制造成本低、对金属腐蚀性小等特点,在切断电源清洗的条件下,也能够满足空调污垢的清洗要求。 相似文献
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The experimental performance of small-sized ground-coupled heat pump (GCHP) is researched intensively. However, there are little data documenting the operation performance of existing large-sized GCHP system. We presented the actual performance measurement of a GCHP installed for apartment buildings in Wuhan, Hubei province, P. R. China. The system was constructed with a closed vertical typed ground heat exchanger with a total pipe length of 32 000 m. During one year, various operating parameters were monitored, including the outdoor temperature, the flow rate, the electrical consumption, and the water temperature. The seasonal coefficients of performances of the heat pumps and the system based on the measured data were found to be 4.01 and 2.96 in the cooling season, and 3.54 and 2.86 in the heating season, respectively. The GCHP system was more economical than the air-source room air conditioner in the energy efficiency which was increased by 29 in cooling mode and 50 in heating mode. There was an obvious heat imbalance of soil between the injection rate and the extraction rate in the residential GCHP system operation. 相似文献
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In order to utilize solar energy effectively and to achieve a higher electrical efficiency by limiting the operating temperature of the photovoltaic （PV） panel, a novel photovoltaic/thermal solar-assisted heat pump （PV/T-SAHP） system was proposed and constructed. The hybrid solar system generates electricity and thermal energy simultaneously. A distributed parameters model of the PWT-SAHP system was developed and applied to analyze the system dynamic performance in terms of PV action, photothermal action and Rankine cycle processes. The simulation results indicated that the coefficient of performance （COP） of the proposed PV/T-SAHP can be much better than that of the conventional heat pump. Both PV-efficiency and photothermic efficiency have been improved considerably. The results also showed that the performance of this PV/T-SAHP system was strongly influenced by the evaporator area, tube pitch and tilt angle of the PV/T evaporator, which are the key factors in PV/T-SAHP system optimization and PV/T evaporator design. 相似文献
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Study on performance of a packed bed latent heat thermal energy storage unit integrated with solar water heating system 总被引：1，自引：0，他引：1
NALLUSAMY N. SAMPATH S. VELRAJ R. 《浙江大学学报(A卷英文版)》2006,7(8):1422-1430
INTRODUCTION Efforts of rational and effective energy man-agement, as well as environmental considerations, increase the interest in using renewable energy sources, especially solar energy. Because of discrep-ancy between the energy supply and demand in solar heating applications, a thermal energy storage (TES) device has to be used for the most effective utilization of the energy source. Energy storage combined with solar collectors and photovoltaic systems have been developed over the… 相似文献
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自然能量较弱、油藏渗透率低、能产低是油田在开发中面临的的主要问题,需要注水补充地下能量来继续开发,又因为地下有天然微裂缝存在,增加了注水开发的难度,所以油藏注水后见效、见水差异较大。为了提高驱油效率,有效地扩大波及面积,最有效的方法之一就是改善驱替状况。分层注聚工艺主要可分为单管注聚工艺和同心双管注聚工艺两大类,单管注聚工艺主要有偏心单管、单管多层分注以及其它单管注聚工艺等。分层注聚工艺可以相应的控制层间聚合物溶液的吸收量和注聚剖面,避免聚合物沿高渗透带单层突进,使难动油层得到开发,效果好于普通注聚工艺。并且在矿场应用中取得了明显的效果。通过地层特征对比提出在陕北地区应用分层注聚工艺的需求。 相似文献
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李明高 《湖南第一师范学报》2011,11(2):13-18
洗课的含义可从教学思想、教学策略、教学境界三个层面来理解。洗课对纠正新课程实施中的偏差、提高课堂教学效率、促进教师专业成长具有十分重要的意义。洗课宜遵循本色性、简约性、有效性的原则。洗课的基本方法有挤水分、去噪音、打枝杈。挤水分即挤教学目标、教学内容、教学过程、教学方法、教学语言、教学训练的水分;去噪音即去情境设计、媒体使用、活动安排的噪音;打枝权即避免教学随意性,力求教学有界、生成有度、拓展有边。 相似文献
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为提高链条液压张紧器在振动过程中的阻尼性能,在对张紧器动力学分析的基础上,使用AVLExcite—TD软件建立其仿真模型．以阻尼能为评价指标对其关键参数进行正交试验,通过对试验结果极差、方差分析张紧器参数对阻尼性能的影响,实现其全面优化,参数优化后阻尼能提高59．70％．在25～200Hz激励频率下．阻尼能为3．2731～5．1337J,在各频率下均具有良好的阻尼性能． 相似文献
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王洪亮 《石家庄职业技术学院学报》2014,(2):24-26
针对当前在标准行驶工况下开发的混合动力电动汽车优化控制策略不能根据变化的行驶工况动态调整控制策略的问题,提出一种基于模糊神经网络的混合动力电动汽车动态能量管理策略：先利用模糊神经网络进行工况识别,然后根据识别的工况类型动态调整自身控制参数.仿真实验显示,该策略可以有效提高混合动力汽车的燃油消耗,并降低污染物的排放量. 相似文献