炼铁卸料小车的改造

通过分析研究卸料小车原来存在的问题，提出了相应的改进措施，改善了职工的工作环境，为高炉的稳产、高产打下了坚实的基础。     

空拔铝及铝合金圆管壁厚计算—双周数表的应用

介绍了计算空拔铝合金圆管壁厚的双周数表。该数表运算操作简单，计算精度符合生产要求。本文36例的平均误差δ－3．19％（道次平均误差δ′＝0．97％）。使用双周数表，可以有效地控制空拔后圆管壁厚，它为生产壁厚负偏差和高精度管材创造条件，可以使生产厂创造更多的经济效益和社会效益。双周数表对其他金属圆管也适用。     

铜镍合金管—板密封焊的气孔问题及解决措施

实验分析了大型换热器铜镍合金管板焊接易出现的气孔问题，阐述了气孔产生的原因及解决方法，并确定了 合理的焊接生产工艺。     

浅析沉管灌注桩施工质量问题和处理措施

介绍沉管灌注桩及其特点,然后提出在沉管灌注桩施工中经常会遇到断桩、缩颈、管内混凝土拒落和桩尖虚脱等施工问题,根据具体的工程实例定性或者定量的分析原因,同时提出合理的处理措施,并且提出能较好解决这些质量问题的新工艺。     

铜铝双金属管连续衬拉复合成形的研究

采用连续衬拉复合工艺线路对铜铝双金属管成形规律进行研究 ,全面探讨了变形量和后序的热处理工艺对界面强度的影响 ,以及在成形过程中组元金属的变形规律。界面强度受变形量及热处理工艺影响较大 ,且组元金属存在不均匀变形规律 ,这为合理制订铜铝双金属管拉伸复合工艺提供了依据。     

Comparison of two models of a double inlet miniature pulse tube refrigerator: Part A thermodynamics

The cooling of electronic components is of great interest to improve their capabilities, especially for CMOS components or infrared sensors. The purpose of this paper is to present the design and the optimization of a miniature double inlet pulse tube refrigerator (DIPTR) dedicated to such applications. Special precautions have to be considered in modeling the global functioning of small scale DIPTR systems and also in estimating the net cooling power. In fact, thermal gradients are greater than those observed in normal scale systems, and moreover, because of the small dimensions of ducts (diameter), the pulse tube cannot be assumed to be adiabatic. Hence thermal heat conduction phenomena must be considered. Besides dead volumes introduced by junctions and capillaries cannot be neglected any more in front of the volume of the gas tube itself. The hydrodynamic and thermal behaviors of the cooler are predicted by means of two different approaches: a classical thermodynamic model and a model based on an electrical analogy. The results of these analysis are tested and criticized by comparing them with experimental data obtained on a small commercial pulse tube refrigerator.     

Discussion on refrigeration cycle for regenerative cryocoolers

Based on review and analysis of thermodynamic efficiency ε of the Carnot cycle and the cycle with two isothermal and two polytropic processes, another thermodynamic cycle with two isentropic and two polytropic processes, which can achieve the Carnot value of thermodynamic efficiency, is testified theoretically. Thermodynamic efficiency expressions of a number of ideal regenerative refrigeration cycles are derived, including the ideal pulse tube refrigeration cycle. A classified branch chart and a plot of ideal thermodynamic efficiency of regenerative refrigeration cycles are given for the purpose of comparison.     

花瓣形翅片管的强化传热研究概况

综述了花瓣形翅片管在低表面张力介质及其混合物中的冷凝强化传热、含不凝性气体水蒸气的冷凝强化传热以及空气和油的冷却强化传热等方面的研究概况、进展、成果及其工业应用前景。     

A vibrating tube flow densitometer for measurements with corrosive solutions at temperatures up to 723 K and pressures up to 40 MPa

A new version of a vibrating tube flow densitometer has been designed permitting measurements of density differences between two fluids in the temperature range from 298 to 723 K and at pressures up to 40 MPa. The instrument is equipped with a Pt/Rh20 vibrating tube (1.6-mm o.d.) and a Pt/Rh10 transporting tube (1.2-mm o.d.) permitting measurements with highly corrosive liquids. The period of oscillation of the tube is about 7.5 ms, with a typical stability better than 10⁻⁴% over about a 1-h period over the entire temperature interval. The calibration constantK at room temperature is about 530 kg·m⁻³·ms⁻², with a temperature coefficient of approximately −0.13kg·m⁻³·ms⁻²·K⁻¹, and is practically pressure independent. It can be determined by calibration with a reproducibility generally better than 0.1%. The instrument was tested with NaCl(aq) solutions in the temperature range from 373 to 690 K for density differences between sample and reference liquid ranging from 200 to 2 kg·m⁻³; the corresponding errors are believed to be below 0.3 and 5%, respectively. A highly automated temperature control maintains the temperature of the tube stable to within ±0.02 K.     

不锈钢换热器管束断裂原因初探

对抚顺石油二厂石蜡加氢装置热高分气冷却器E-3A不锈钢U形管束周向开裂的原因进行了初步探讨,从管束的选材、制造、使用、开裂管子外观检查、金相检验、断口分析、腐蚀产物分析几方面得出结论:不锈钢U形管周向开裂是由于在含有氧化物的高温水和水蒸气的腐蚀介质中引起应力腐蚀破裂,直接原因是管束选用的1Cr18Ni9Ti碳含量偏高,且整体热处理工艺严重失误共同造成严重的晶间腐蚀。对防止应力腐蚀开裂提出了相应的措施。