为了改善混合料仓的给料状况,对传统混合料仓的给料闸门和新型混合料仓的给料闸门的组成、工作原理和结构特点进行了逐一分析和比较,指出传统给料闸门采用主辅门结构,由扇形门和扇形门上的微动闸门组成,生产中主调扇形闸门,结构笨重,故障率高,而新型给料闸门取消了主门,用原辅门来替代工作,并对结构和控制方式进行了优化改进.

为了解决国内烧结机厂房楼板吊装孔的日常安全问题,设计了一种电动盖板,当烧结机厂房无吊装作业时,可实现对吊装孔的封闭,保证人身安全.当需要进行吊装工作时,可以通过电动方式控制盖板打开.采用一键电动控制盖板的提升,自动折叠,盖板完成打开后自动停机,并可以实现自锁.该系统操作方便,节省人力,可靠性高,占用空间小,对吊装作业不产生阻碍.在无吊装作业时,可以实现盖板回程反向闭合,保证人身安全.

In adaptive learning system, the key to promote personalized learning is the learner model. The Elo model has great potential in online learning environment, so based on it, we propose the EELO which is an improved extension of Elo rating system, in view of polychotomously scored items and different granularity evaluations that the Elo rating system do not cover. The performance of the EELO estimating learners’ abilities and predicting their future performances are evaluated on two large data set, which demonstrates that the EELO is better-performing. Then, we apply it in a real online learning environment to provide an analysis report for different user roles, which also can be used as the reference for the development of adaptive learning applications in the future.

Compared with traditional teaching mode, network teaching has advantages, but its defects are obvious. This paper selected some samples and analyzed them according to certain standards, pointed out the shortcomings of modern network education teaching, and finally put forward some suggestions and measures from the aspects of education mode, resource integration, system norms and so on.

对窑街油页岩和龙口油页岩采用酸洗处理,脱除矿物质后采用美国康塔公司生产的AWTOSOB自动吸附仪,对脱矿物质前后的两种油页岩以及所制得的半焦进行低温氮吸附实验.结果表明:脱矿物前后的油页岩及半焦均拥有从小至分子级到大至无上限的较连续的完整的孔系统,且脱矿物质改变油页岩的孔结构,使其比表面积和孔径增大,通过傅里叶红外(FT-IR)表征脱矿物质前后的油页岩,得到矿物质特征峰的消失以及有机官能团的增多导致了油页岩孔结构发生变化.

回收制冷系统的热量(即热回收)是提高其经济性的有效方法,也是实现节能减排的重要途径.对工业螺杆制冷系统可能被回收的热量的分析表明:油冷却器、过热回收器和冷凝器中的热量占总热量的比例分别约为10％～40％、10％～15％、77％～ 33％,其中前二者的热量品位高,冷凝器中的热量品位较低,此三部分热量是热回收的重点;过冷器中的热量较少且品位最低.提出了全热回收的概念,定义了带热回收制冷系统的性能系数和全热回收性能系数,后者的意义是给出了全热回收最高效率的计算方法;最后提出了建议的全热回收流程.

为了提高能源与动力工程特色专业学生的工程素质,实现高素质人才培养的目标,我们紧密结合理论教学体系的改革,开展实验室的建设与实验教学改革、校外实践环节的建设、毕业设计以创新和素质培养为中心的一系列教学改革,经过多年的努力,取得了一定的效果.

This study established a low -temperature recovery system with tube condensation recoverer and low temperature circulators to recycle the methylene chloride solvent in vacuum distillation. Through experiments under different refrigerant tem- peratures, recovery rate reaches 93%. Researches on temperature factors which influence recovery effects show that the optimal refrigerant temperature is - 10℃. The experiments show that the recovery system can realize the methylene chloride recovery ef- fectively.

In order to select the mixed refrigerants used in three-stage auto-cascade system, a method were proposed for choosing the component of mixture, R134a£¯R23£¯R14£¯R50 were chosen as a mixture for the equipment. After raising the hypotheses of some ideal state, the refrigeration cycle in the system was simplified. R50 was ignored having unnecessary influence on system and it was considered that there was only R134a£¯R23£¯R14 in the refrigerating cycle. Circular flow of each component in the cycle was calculated with the series heat balance method, and the best proportion of constituent of mixture according to experimental result was compared with the flow quantity of R14 as a unit, After analyzing the reason causing the error, the feasibility was pointed out for selecting the proportion of mixture in the manufacturing process of actual device by calculating.

为了确定R50对-100℃温区三级自动复叠系统中后期运行状态的影响,分别以R134a/R23/R14、R134a/R23/R14/R50为混合工质在同一台实验装置上进行两次试验,其中R134a、R23、R14组分充注量相同。通过对两组工质进行实验和对比分析,发现添加R50时第二、三级分凝器蒸发温度和冷却后温度更低,但是系统压力明显更高,设备耗能增加,达到设计温度所需时间增长,因此在-100℃温区的自动复叠系统混合组分添加R50会对系统的性能不利。

In order to select the mix refrigeration used in three-stage auto-cascade system,some notes were pointed out for choosing the component,R134a/R23/R14/R50 were chosen as a mix for the equipment.After simplifying the refrigeration cycle process in the system and giving out some suppose in ideal,R50 was ignored for not necessary and it was considered that there was only R134a/R23/R14 in the cycle.Each component cycle flow in the cycle was calculated with series heat balance method and compared with the best component ratio,which was suggested according to experiment result with the flow quantity of R14 as a unit.After analyzing the reason which caused the error,the feasibility was pointed out for selecting the mixture refrigerant component ratio in actual device manufacturing process by calculating.

目前随着能源危机,书籍的成本价也在逐年上升。为缓解学校目前专业书籍紧缺的现象,我们根据学校的实际情况制订了热能与动力工程专业中英文电子图书文库。该文库使用简单方便、信息量大,投入使用以来,受到广大师生的一致好评。

制冷系统各部件间通常用铜管连接,钢管与部件之间、各铜管之间的接头常采用钎焊连接,因此,钎焊质量优劣对连接质量和流动是否通畅起决定性作用.

For the design of moisture-proof and vapour insulation of the cryogenic test equipments,the performance requirements of the materials were introduced. The condition that moisture doesn't condensate and freeze was analysed and the formula for calculating the thickness of the moisture-proof cross was also obtained.

This paper developed a single-compressed four-stage segregating auto-cascade refrigeration system,the temperature of the liquid coolant in the tank with 5L could reach 150K.Cooling process after throttling were analyzed,the effect of the different proportion of the refrigerants was also pointed out.

Auto-cascade refrigerating system is applied in low temperature instruments in order to let up the volume and reduce the weight of refrigeration system.According to series connection type,3-stage evaporator condenser,high temperature regenerator and low temperature regenerator are put together to improve on a combined heat exchanger.The system is predigested and leakage parts are reduced.Then the different ratios of mixed refrigerants are compared.Temperature dropping experiments are carried out in a low temperature cooling circulation instrument with 5 liters/-100℃.The result indicates the effect of R134a/R23 /R14 is better than the others.So the auto-cascade refrigeration system can work steadily,it can replace cascade refrigerating system.

To obtain the low temperature of 150 K,the design of four-stage auto-cascade refrigeration(ACR) was set up.The R134a/R23/R14/R50 refrigerant mixture was used in the system.The each point's parameters of the system were calculated using NIST.According to the literatures and the empirical formula,the compressor,condenser,evaporator and heat exchanger were designed and choosed.

The thermodynamic process for obtaining the 120 K temperature range was proposed based on the mixed-refrigerant using segregation Linder refrigerator with pre-cooling cycle.The experiment set-up was established.The system performances were investigated under different composition of ternary refrigerant(R23/R14/R740).The experiment results showed that the best ratio of ternary refrigerant(R23/R14/R740) was 0.63:0.28:0.09,the refrigerating temperature without heat loads was 123 K and the cool-down time was 3 h.

To the reducing discharge and making cold system with capillary,this paper analysis the compressor's and capillary's characteristics when the temperature are changed.According to the quantity discharge balance relation of capillary and compressors when they are in the different condensate pressure and different evaporate pressure,reaching a conclusion that when working situation is far away from the suited situation,the system's capability of making cold will be bad.