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。     

Pitometry as a validation tool for water flow measurement in large diameter pipelines

Accurate measurement of water flow rates in large diameter pipelines is a challenge for water companies that need to produce, transport and distribute increasing quantities of water. To a large extent, this challenge results from the impossibility of recalibration of the flow meters within the periodicity established in the metrological regulations since the removal of a large size flow meter from its site of operation in the field and its transport to a calibration laboratory is in most cases technically and economically impracticable. Because of this scenario, this paper presents the pitometry technique as an interesting alternative to solve problems related to the validation of water flow measurements performed by flow measurement systems installed in large diameter conduits. The technique is based on the determination of the water flow rate by mapping the velocity profile of the water flow inside the pipe by means of Cole type Pitot tubes. The water flow rate is determined in a cross section of the pipe located near and in series to the flowmeter to be evaluated. Based on the results obtained in a great number of water flow measurements already performed by applying the pitometry technique in large diameter pipelines in the field, it is possible to conclude that this methodology is perfectly applicable in the validation of the performance of flow meters installed in these conduits solving satisfactorily the issues related to its operation.     

Performance review of a novel combined thermoelectric power generation and water desalination system

A novel combined thermoelectric power generation and water desalination system is described with a system schematic. The proposed system utilises low grade thermal energy to heat thermoelectric generators for power generation and water desalination. A theoretical analysis presents the governing equations to estimate the systems performance characteristics combined with experimental validation. Experimental set-up consists of an electric heat source, thermoelectric modules, heat pipes, a heat sink and an evaporator vessel. Four heat pipes are embedded in a heat spreader block to passively cool the bottom side of the thermoelectric cells. The condenser of these four heat pipes is immersed in a pool of saline water stored in an evaporation vessel which is maintained at sub-atmospheric pressure. The liquid to vapour phase change cooling method achieve low saturation temperature and offers a high heat transfer coefficient for the cooling of the thermoelectric generators. At the same time this method utilises the low temperature heat extracted from the cold side of the thermoelectric generator for water desalination. It was observed that at low saturation temperatures greater heat flux could be supplied to the thermoelectric generators with less heat losses to the atmosphere.     

Fracture toughness of high strength seamless pipe steel from SE(T) and SE(B) specimens evaluated by different standards

Recently released, BS 8571:2014 standard offers an alternative for the experimental determination of fracture toughness and resistance curves of metallic materials from SE(T) specimens. Similar in stress conditions and constraint to cracked tubes, specimens in SE(T) geometry should yield less conservative toughness values than conventional high‐constraint specimens, such as SE(B) geometry. However, the convention to determine the J‐integral fracture toughness proposed in the new BS standard is different from ASTM standards. In this work, SE(T) and SE(B) specimens of similar dimensions of a tough high‐strength seamless pipe steel were tested following the BS 8571:2014 and ASTM E1820‐16 standards, respectively. Because of the different standardized definitions, SE(T) specimens yield lower fracture toughness than SE(B) specimens, which could lead to more conservative results in structural integrity analysis. This investigation also suggests the introduction of the blunting line concept in the BS 8571:2014 standard in order to minimize this problem.     

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。     

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。     

国产CODECASE2115小口径管焊接接头性能研究

依据国产CODECASE2115小口径管材的成分和性能,合理选择了焊接材料和焊接工艺,并对焊接接头进行试验与分析,验证了可以获得合格焊接接头的相应的焊接材料和焊接工艺,实现了超超临界锅炉中耐热钢管国产化材料的焊接工艺,扩大了耐热钢管及焊接材料的供货方范围,且国产的CODECASE2115奥氏体钢管与国外同类材料相比,价格与供货期都更有优势,也为这种材料在超超临界机组中的应用积累了试验数据。     

焊接钢管超声波自动探伤系统中的软件设计与应用

分析了焊接钢管超声波自动探伤系统的软件设计以及在焊接钢管检测中的应用状况。把传统的超声波检测技术和先进的工业控制计算机、虚拟仪器和智能化探伤等技术相结合,配合精心编制的探伤操作程序,可做到对复杂缺陷回波的准确评价和严格筛选,有效地避免了系统的误报警。缺陷波形回放功能克服了超声波自动探伤中的缺陷种类难以识别的不足,并做到误报率〈2％,漏报率为0。