冷轧翅片管散热器的设计

本文介绍了一种新型柴油机散热器。它采用了一种新型散热元件－冷轧翅片管,设计中不改变原散热器的尺寸,整个冷却系统的其它附件也不做改变,因此易于应用。其优势在于能节约大量的贵金属铜,而且散热系数较高。     

滚压技术在气缸套加工中的应用

发动机心脏零件气缸套,因疲劳导致断裂失效已屡见不鲜.为提高疲劳强度,国外已有少数气缸套厂家采用滚压技术,在支承肩下端面用沉割槽(R槽)来代替直槽,并且进行滚压处理,效果十分明显,国内也有几个气缸套生产厂家率先应用了滚压技术.我厂通过反复实践,认真总结成功的经验,不断完善和提高.现已初步掌握了此项技术的工艺要求以及各种滚压参数的合理选择,使产品质量稳定和提高,得到主机厂的高度评价.本文就滚压过程中遇到的问题以及采取的解决办法,谈点粗浅的看法,仅供参考     

翅片管立式蒸汽发生装置的研制

介绍一种新型翅片管立式蒸汽发生装置。该装置具有体积及占地面积小、热效率高、设备漏气率为零、设备投资少且使用寿命长、使用范围广、易于维修等优点。有着重要的推广价值和广阔的应用前景。     

螺旋翅片管省煤器的布置方案

本文提出了一种“３并２”的管排布置方案，其烟气侧流速适中，可减轻烟气对传热管的冲刷磨损，减少省煤器爆管事故。     

曲轴滚压加工的数值模拟

从轴颈滚压加工的二维平面问题入手,对其滚压加工过程进行了数值模拟,研究了滚压道次、摩擦系数对塑性变形层和残余应力的影响,轴颈滚压加工的二维模拟表明:滚压道次对变形层的总厚度、局部塑性应变的数值及其分布的影响很小,摩擦力有一定的表面硬化作用,但相对来说,随着摩擦系数的增大次表层和深层残余应力提高并不明显;在此基础上建立了曲轴圆角滚压加工的三维刚一柔接触的压入-分离模型,通过与小野式滚压试件的试验结果比较,结论为:在工件的最表层,由于有限元方法不能考虑材料的硬化效应,残余应力数值偏小,x射线法实测的残余应力则较为准确,而在工件的亚表层乃至深层,计算结果与试验结果的残余应力吻合较好.     

为加工特殊汽封齿所设计的滚压刀具

对生产中所遇到的特殊角度汽封齿的加工问题,设计了专用滚压刀具,并提出了实施方案。     

螺纹管滚压机设计简介

介绍一种螺纹管滚压专用设备的设计原理及结构。     

滚压和挤压加工

本文介绍了常用表面的滚、挤压加工方法以及常见滚、挤压加工工具的结构形式。对滚压余量,滚挤压压力等各种技术参数的选择作了较为详细的说明。文中还特别列举了珠式内孔可调滚压器、轮式丝杆滚压器、多环挤压刀等10多种典型的滚挤压工具的应用实例。     

Analysis of a bayonet tube heat exchanger

This paper details the design, construction and testing of a bayonet tube heat exchanger for use in the process industry and potentially as part of an externally fired combined cycle. Detailed analysis of the system has been undertaken, in particular on the tube side. The data is reported in terms of temperature, pressure, heat gain and heat exchanger effectiveness, over a range of Reynolds numbers and shell side mixture ratios. Much of the heat gained by the tubes is in the annular flow of the bayonet tube. Overall the effectiveness of this system could exceed 70%.     

新型螺旋管换热器的设计

主要介绍了螺旋管换热器的结构设计和在具有过冷情况下的热力计算方法。     

On the mechanical analysis of a tube heat exchanger

This paper describes the results of a mechanical analysis of some components (such as tubes, tube plate, etc.) of tube heat exchangers. The stability of tubes in a tube heat exchanger is examined as an example     

High performance finned tube heat exchanger design

A rational approach to the design of gas-fired finned tube heat exchangers is presented. As a result of an extensive literature search and a study of flue gas properties, novel equations have been developed to facilitate design procedures. Comparisons are made between the theoretical performance of a finned tube boiler and those determined experimentally.     

Finite element analysis of shell and tube heat exchanger

A finite element model to predict temperature distribution in heat exchangers is reported. The model can be effectively used to analyse and design the heat exchangers with complex flow arrangements for which no regular design procedure is available. Illustrations are provided to explain the application of the method for the analysis of shell and tube heat exchangers.     

热管和内螺纹管在低温空气预热器中的应用

结合目前低温空气预热器存在的问题和实际应用的结果，通过对光管、内螺纹管和热管的传热，流动阻力以及壁温（低温腐蚀）性能进行对比分析，阐述了内螺纹管和热管换热器作为空气预热器的优点，并说明了它们的适用条件。     

锥形内肋管传热与流阻性能的数值模拟

根据纵向涡强化传热技术提出了新型的强化换热管——锥形内肋管,运用数值模拟方法,研究了新型强化换热管结构参数锥底宽度a、导程P、肋深e和Re数对Nu、沿程阻力系数f及传热综合因子η的影响。结果表明：换热管内壁面边缘处产生了较多的微小涡流,有效破坏了流动边界层,强化了传热。在充分湍流的条件下,流体Re越小、e越小,其综合传热性能越强。当Re<15 000时,a对η的影响要大于P;在过渡点后, P对η影响较大。通过综合传热性能分析,给出了适合不同Re区间的锥形内肋优化参数。     

Second law analysis on the heat transfer of the horizontal concentric tube heat exchanger

In the present study, the theoretical and experimental results of the second law analysis on the heat transfer and flow of a horizontal concentric tube heat exchanger are presented. The experiments setup are designed and constructed for the measured data. Hot water and cold water are used as working fluids. The test runs are done at the hot and cold water mass flow rates ranging between 0.02 and 0.20 kg/s and between 0.02 and 0.20 kg/s, respectively. The inlet hot water and inlet cold water temperatures are between 40 and 50 °C, and between 15 and 20 °C, respectively. The effects of the inlet conditions of both working fluids flowing through the heat exchanger on the heat transfer characteristics, entropy generation, and exergy loss are discussed. The mathematical model based on the conservation equations of energy is developed and solved by the central finite difference method to obtain temperature distribution, entropy generation, and exergy loss. The predicted results obtained from the model are validated by comparing with the present measured data. There is reasonable agreement from the comparison between predicted results and those from the measured data.     

管翅式换热器遗传算法优化

管翅式换热器作为一种高效的换热设备,提升其换热效率和降低投资成本显得至关重要.通过单目标遗传算法(GA)和多目标非支配排序遗传算法(NSGA-Ⅱ)对管翅式换热器进行优化设计,设置翅片高度、翅片间距、管长、横向管数和纵向管数5个自变量的合理设计范围,单目标优化选用换热器效率、压降熵产和最大收益3个目标函数,根据热力学第一...     

管壳式换热器蓄热单元数值模拟与优化

相变材料导热系数低,导致相变蓄热装置无法快速地进行热量储存和释放,文中建立了翅片管和光管式相变蓄热单元的三维计算模型,采用数值模拟方法,从蓄热速率、蓄热量以及温度场等方面比较分析了翅片管和光管结构对储热性能的影响。结果表明:在光管外壁添加翅片可以缩短相变材料完全熔化以及整个蓄/放热过程所需时间;与采用光管结构相比,采用翅片换热管时,完全熔化时间缩短32%,完全放热时间缩短14.5%。可见,在一定条件下添加翅片有助于提高蓄热体的蓄放热性能,所得结论对实际工程中相变蓄热系统的设计和优化具有一定的参考价值。