直接接触式制备CO2水合物的生长和蓄冷特性

采用直接接触式水合物反应釜,并在釜内初始水温为26℃和15℃以及充注压力为3.6～4.2 MPa的条件下制备CO₂水合物,研究其生长和蓄冷特性。实验结果表明:在初始水温为15℃、充注压力为3.6 MPa时,预冷时间较短(11 min),水合物开始生长时过冷度约为1.3℃,温升不明显,平均蓄冷速率和平均蓄冷效率分别为82.4 kJ·min^-1和4.34;在其他温压条件下,预冷时间较长(20～55 min),但随充注压力的升高而减小,过冷度较大(5.5～9.7℃),水合物生长迅速且密集,温升明显,并在充注压力为4.0 MPa时温升幅度最大,水合物平均生长速率、总蓄冷量、平均总蓄冷速率和效率随充注压力的升高而变大,其最大值分别为77和154 g·min^-1,3.725和3.791 MJ,64.1和99.5 kJ·min^-1,3.14和 4.91。水合物释冷分解是一个相变过程,相变温度一般在10～14℃。     

Phenomenological characteristics of cool-flame oxidation of cyclohexane

The phenomenological characteristics of cool flames of cyclohexane are studied. It is shown that cyclohexane flames arise at lower temperatures (beginning at T ≈ 230°C) and lower pressures (lower than 10 torr at T = 290°C) than alkane and alkene flames. The temperature dependence of the lower pressure limit of the cool flame is determined. It is established that, depending on the conditions (p, T, and C₆H₁₂/O₂ ratio), cool-flame ignition is characterized by a rise and drop of the temperature ΔT or by several peaks imposed on each other. The dependence of the cool-flame structure (for ΔT) on the oxygen content in the reaction mixture is studied. It is shown that the cool flame resulting from cyclohexane oxidation is accompanied by ring opening and formation of products with a smaller number of carbon atoms. It is established that cool flames of cyclohexane are characterized by a negative temperature coefficient. __________ Translated from Fizika Goreniya i Vzryva, Vol. 44, No. 1, pp. 26–28, January–February, 2008.     

冷却条件对超级钢钨极氩弧焊焊接接头组织性能的影响

采用钨极氩弧焊焊接方法对400MPa级超级钢进行焊接，并对焊后空冷和水冷两种冷却条件下的焊接接头进行了组织性能分析。研究结果表明，水冷条件下，其接头的综合力学性能要优于空冷条件，可以应用与实际生产。     

氧化锆微滤膜处理冷轧乳化液废水的研究

本文对氧化锆微滤膜处理冷轧乳化液废水的过程进行了研究 ,主要考察了强化传质及高频反冲对延迟膜的污染 ,降低操作能耗的影响 ;对膜污染层进行了微观分析 ,并对各种清洗剂的清洗效果进行了比较 ,得出了膜通量基本恢复的清洗方法 ,并且考察了清洗的重复性 ,确定了效果好且稳定的清洗方法 ,为工业化的进一步应用奠定了基础     

Cooling load reduction of building by seasonal nocturnal cooling water from thermosyphon heat pipe radiator

In this study, a concept of using thermosyphon heat pipe to extract heat from water in a storage tank to generate cooling water was proposed. Heat pipe condenser was attached with an aluminum plate and acted as a thermal radiator while its evaporator was dipped in the water storage tank. Cooling water in the tank could be produced during the nighttime and used to serve the cooling load in a room during the daytime. A heat transfer model to calculate the water temperature and the room temperature during both the nighttime and daytime was developed. The input data were ambient temperature, dew point temperature, area of the radiator, volume of cooling water and room cooling load. The experiment was setup to verify the heat transfer model. A 9.0 m² tested room with six cooling coils, each of 0.87 m² was installed at the ceiling, was constructed along with the 1.0 m³ water storage tank. A 500–2000 W adjustable heater was taken as an artificial load inside the room. A 6.36 m² radiator is installed on a 45° tilting roof of the tested room. The simulated results agreed very well with those of the experimental data. With the developed model, a simulation to find the sizing of the radiator area and the volume of cooling water for cooling water production during winter of Chiang Mai, Thailand was carried out. The cooling water was used for cooling during summer in an air‐conditioned room with different cooling loads. The parameters in terms of room temperature, radiator area, volume of cooling water, cooling load and UA of cooling coil were considered to carry out the percent of cooling load reduction. Copyright © 2009 John Wiley & Sons, Ltd.     

空调系统节能措施浅析

从改善围护结构的保温性能、合理确定室内温、湿度、采用合理的空调系统及冷源方案等方面提出了空调系统的节能措施,旨在通过能源利用的各个环节和系统在规划到运转的全过程中贯彻,从而达到节能的效果。     

利用地下空间空气蓄冷供冷中最佳通风量的研究

本文对空气流经地下空间中的能量传递过程建立了简化的数学模型,分析了利用地下空间空气蓄冷供冷系统运行的送排风临界温差,并对上海某实际工程中利用这一系统的最佳通风量进行了计算,进一步分析了通风系统阻力、送风温度、地下空间尺寸以及系统运行方式等因素对最佳通风量的影响。     

提高微型柴油机冷启动性能的研究

本文介绍了用自制的电阻丝温度传感器及压力传感器对小型柴油机缸内气体瞬时压缩温度和压力的测量,总结了各种因素对瞬时压缩温度和压力的影响规律,指出了提高小型柴油机冷启动性能的根本性措施:在主燃烧室内设计一个局部集中的高温区域,让油束能部分进入该高温区域;指出了每一台机均有一最佳启动转速和最佳启动供油量;良好的润滑有利于有效启动;提出了用可燃温度的温—时面积值,判断启动性能的好坏及有效启动的可能性.     

网络化空调冷量收费和管理系统的设计

根据现代智能大厦的实际要求，提出了空调冷量收费实现自动化、网络化的必要性，并重点介绍了网络化空调冷量收费和管理系统的设计思路和基本原理。     

低悬浮物水样SS测定出现负值的探讨

低 SS(≤ 1 0 mg/L)水样的 SS测试过程中 ,天平的及时校准、冷却条件的严格控制、干燥剂的更换频率、滤纸等方面 ,对其测试结果有很大影响。对大量的试验数据进行对比 ,提出了相应的解决措施