油罐脱水管线的冬季防冻

介绍了一种实用的冬季油罐脱水管线防冻方法———电伴热法,此方法具有设计工作量小,施工简单,维护方便,日常维护工作量小等优点。     

供水工程给水管道的选择

目前,应用于给水领域的管道从材料上分为金属和非金属两大类.近年来,为发挥各种材料的优势,给水用复合管道发展很快,如塑料与塑料复合,塑料与金属复合等.选择给水用管道的原则是:物理机械性能良好,强度高,保证连续、安全、可靠供水;管材及所有配套产品,都要保证卫生性能符合标准要求.     

浅谈埋地硬聚氯乙烯排水管在市政工程中的应用

本文从管材特性、管道参数计算、施工流程等方面对埋地硬聚氯乙烯排水管在市政工程中的应用进行了叙述,并将其与市政工程中常用的其他管材进行比较,埋地硬聚氯乙烯排水管这种新型管材在市政工程应用中是可靠可行的。     

新型管材在建筑给排水工程中的应用

建筑工程规模的不断扩大促进了建筑给排水工程的增多。建筑给排水新型管材的选择和运用成为了一个重要的热点问题。本文针对新型管材在建筑给排水工程中的应用进行了探讨。     

注射模高光技术设计原理

结合录像机高光前面板的设计,简单介绍注射模高光技术设计原理,主要目的是对传统模具设计进行创新。     

Frequency-dependent damping model for the hydroacoustic finite element analysis of fluid-filled pipes with diameter changes

The integration of a model for longitudinal hydroacoustic fluid damping in thin hydraulic pipes in 3D finite element models is presented in this paper. In order to perform quantitative prediction of the vibroacoustic behavior and resulting noise levels of such fluid-structure coupled system due to hydraulic excitation, an accurate frequency-dependent fluid damping model including friction effects near the pipe wall is required. This step is achieved by matching complex wave numbers from analytical derivation into a parameterized damped wave equation and consecutive translation into finite element modeling.Since the friction effect close to the pipe wall changes locally with the inner pipe radius, the fluid damping model is applied segment-wise in order to model the influence of cross-sectional discontinuity, such as orifices, on the oscillating pressure pulsations. A component synthesis approach, which uses pipe segments as substructures, allows a simple model generation and fast computation times.The numerical harmonic results are compared to experimental frequency response functions, which are performed on a hydraulic test bench driven by a dynamic pressure source in the kHz-range.     

高压加热器管板不锈钢堆焊层与碳钢管子封口焊工艺

在低合金钢管板上堆焊奥氏体不锈钢与碳钢管子SA556MC2＋16mm×2．12mm进行管子管板封口焊试验时,采用手丁氩弧焊ER309、ERNiCr．3等焊丝,在其焊缝根部产生微裂纹,并对产生的裂纹进行了分析。采用新工艺在管子管端先堆焊隔离层,采用内缩式坡口再进行封口焊解决了焊缝裂纹,2009年1月新T艺申请为发明专利并成功运用到出口的600MW超临界高压加热器。     

单缸二冲程汽油机排气管结构形式与参数对排气压力频谱的影响

本文建立了带有锥形管的排气管系中气流所满足的波动方程.在频域中分析了结构形式不同的排气管系中压力波动频谱特性,并研究了结构参数变化对频谱特性的影响,为二冲程发动机排气管系的设计提供了新的方法.     

Condensation heat transfer and pressure drop characteristics of R-134a in an annular helical pipe

Condensation heat transfer and pressure drop data of R-134a in annular helical pipes is of significant importance to the effective design and reliable operation of helical pipe heat exchangers for refrigeration, air-conditioning, and many other applications. This paper presents the experimental investigation on condensation heat transfer and pressure drop characteristics of R-134a in an annular helical pipe. The average condensation heat transfer coefficients and pressure drops were experimentally determined for R-134a at three different saturated temperatures (35 °C, 40 °C, and 46 °C). The experimental results are compared with the data available in the literature for helical and straight pipes.     

凝结水管道的减振优化设计

首先提出了流体输送管道振动的数学模型，重点推导了在周期激振内作用下管道振动的稳态响应关系，在此基础上深入地讨论了电站汽轮机凝结水最小流量再循环管道的减振优化设计方法，最后给出了一个工程应用实例，说明本文所提出方法的有效性。