Analysis and Application of Variable Conductance Heat Pipe Air Preheater

The heat transfer analysis of variable conductance heat pipe air preheater was carried out. The temperature trans-fer matrix was obtained for the air preheater that comprises several discrete heat transfer units with same or different heat transfer surface area in a parallel or counter flow mode. By using the temperature transfer matrix, the outlet fluid temperatures could be easily calculated for a given air preheater and inlet fluid temperatures. The active length of condenser in a variable conductance he...     

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。     

电站锅炉热管空气预热器优化设计数学模型

提出了电站锅炉热管空气预热器优化设计的数学模型 ;将预热器最低管子壁温的控制条件引入函数矢量 ;对最优化技术在热管空气预热器设计中的应用方法和特点作了说明     

电站锅炉空气预热器改造方案研究

根据低温腐蚀、漏风等原因造成所回围蓄热式空气预热器运行不良,电站锅炉出力不足等问题,文中通过对提出的几种改造方案的比较,论证了利用螺纹管、热管强化传热技术,采用复合式空气预热器对原有空气预热器进行技术改造的可行性。     

基于热泵与低温空预器的燃气锅炉尾气水热回收系统性能研究

燃气锅炉排放的烟气中含有大量的水蒸气,因排烟温度未能降到露点以下而无法有效回收水蒸气的冷凝潜热。本文采用压缩式热泵与低温空预器相结合的方式深度回收燃气锅炉烟气余热,主要研究了在不同过量空气系数下供热回水流量和供热回水温度对排烟温度、余热回收效率、热泵机组制热性能系数及水蒸气冷凝率的影响。研究结果表明：在过量空气系数为1、供热回水流量为80 t/h条件下,热泵可将供热回水温度从50.0 ℃提升至65.1 ℃,其制热性能系数为4.25;空气进、出低温空预器的温度分别为-3.8 ℃和33.0 ℃,流量为15 360 m3/h时,排烟温度从90 ℃降至20 ℃,烟气余热回收效率达到14.8%;以29 MW的燃气锅炉为研究对象,按供热面积为5.2×105m2,供暖151天计算,烟气中回收的冷凝水量为8 000 t,占锅炉补水量的54.1%;该余热回收系统的投资回收期为2.1年,压缩式热泵烟气余热回收系统节能效果显著。     

新型节能传热元件-热管

本文主要介绍了热管的工作原理及其在工业锅炉节能中的应用,以及热管省煤器、热管预热器在锅炉行业中与传统结构相比较所表现出的卓越性能及优点,并对其未来的发展提出展望。     

提高回转式空气预热器性能途径的研究

回转式空气预热器是大型电站锅炉广泛采用的尾部换热设备,空气预热器的性能对锅炉机组的效率有很大影响。通过对回转式空气预热器在运行过程中常见的问题进行分析,提出了提高空气预热器整体性能的方案,并针对这些问题,总结分析并提出了对策,对提高空气预热器的性能具有指导性的意义。     

工业锅炉空气预热器的声振动及其防治

空气预热器的振动会影响锅炉的正常运行,产生的噪音更对工作人员的健康产生不利影响。结合某厂生产的64 MW热水锅炉出现的空气预热器低温段振动案例,对振动的成因进行了分析,并进行了详细的防振计算,计算结果表明已解决了振动问题。较其它文献有一个显著的特点,就是列出了详细的防振计算方法和各项数据的选取依据,计算符号的标识也趋于一致,可供实际计算时参考。     

600MW机组锅炉回转式空预器电流波动分析

通过对回转式空预器电流波动的机理进行分析,结合电厂生产实际和事故处理案例,对回转式空预器运行中可能出现的电流波动现象做一剖析,提出了各种电流波动的原因和处理方法,对电厂同类型回转式空预器电流波动的事故处理有一定的借鉴意义。     

换热器性能对内容积可变空调系统性能的影响分析

文章针对常规空调在压缩机与冷凝器之间增加变容器的内容积可变容空调结构,建立了空调系统的稳态集中参数模型。基于给定的压缩机结构,研究了换热器性能对内容积可变空调系统性能的影响,提出了系统优化的方向。     

管式空气预热器的振动及其消除方法研究

本文分析了由卡门涡流效应引起管式空气预热器振动的机理,从设计角度论述了预防振动的方法,提出了消除已发生振动的措施.     

Three‐dimensional modeling method for heat exchange of rotary air preheater in coal‐fired power plant

A numerical modeling method based on a 3‐D heat transfer model and duct models for a dual‐sectional rotary air preheater have been developed in this paper. Owing to different boundary conditions for the heat transfer model obtained by modeling and calculation of the ducts, this method is capable of calculating the 3‐D metal and fluid temperature fields at different radial locations in the rotary air preheater along the rotor height as well as the rotating period, and furthermore, it can calculate temperature and flow field inside the flow passage as well. A case study with a dual‐sectional rotary air preheater of a typical 300 MW_e unit used as the research object is presented in this paper. The calculation results accord well with those obtained by verified numerical methods in published literature. The difference between the calculated and the measured outlet fluid temperature of the rotary air preheater is smaller than 3 °C. The numerical modeling method presented in this paper is proved to have high precision and is beneficial for the secure and economic operation of a rotary air preheater as well as the whole unit. © 2010 Wiley Periodicals, Inc. Heat Trans Asian Res; Published online in Wiley Online Library ( wileyonlinelibrary.com ). DOI 10.1002/htj.20325     

Investigation into the performance of a micro gravitational heat pipe and a micro gravitational heat pipe with artery

The performance of a normal micro gravitational heat pipe was investigated using the analytical and numerical models previously developed. An innovative structure of the heat pipe, i.e. the micro gravitational heat pipe with artery, was then proposed in an attempt to overcome some of the drawbacks of the normal pipe. The thermal behaviour of the new type of heat pipe was simulated, and this was compared with that of a normal micro heat pipe. A performance estimation of both pipes was carried out based on the simulation results. Copyright © 2002 John Wiley & Sons, Ltd.     

热管式冰蓄冷空调的运行特性及分析

文中论述了热管在冰蓄冷中应用的原理与特点，扩展了热管的应用范围，分析了热管式蓄冰系统的动态特性，建立了相应的物理模型，该模型可为热管式蓄冰系统的设计提供理论依据。     

空预器排烟温度高的原因及解决措施

某电厂3#机组在试运行期间存在空预器排烟温度高于设计值的问题,影响了锅炉的安全经济运行。针对这一问题,进行深入分析,找出影响因素,并提出一系列解决措施,从一定程度上解决了排烟温度偏高的问题。     

热管在空调排风能量回收中的应用

通过对国内外文献的调查,介绍了当前通风空调的能耗现状,热管的结构、工作原理、特点和分类等,并结合已有的实验数据,将装有热管热回收装置的空调系统与传统的一次回风空调系统进行对比,以期探索热管热回收装置在空调排风能量回收中的作用,结果表明.装有热管热回收装置的空调系统比传统空调系统的制冷量和再热量减少,显示了热管换热器在空调系统应用中的优势.表明热管技术可以有效地利用空调排风中的低位热能,具有节能、环保等优点,有较大的开发应用价值.     

配SCR的锅炉空气预热器适应性改造实践

宝钢电厂1、2号350 MW机组锅炉因环保需要增设的烟气脱硝装置(简称SCR)所产生的硫酸氢氨,将引发空气预热器的腐蚀和堵灰现象,从而严重影响锅炉机组的安全运行,因此必须对空气预热器进行适应性改造。对空气预热器适应脱硝改造的设计原则和技术注意事项进行了研究。改造后锅炉排烟温度下降了5~8℃,平均漏风率降低了1%~2%。烟气流动阻力基本维持在800 Pa以下,且未出现明显的积灰堵塞情况。该项目改造取得了预期目标,为行业提供了成功的案例经验。     

Analysis of enthalpy change with/without a heat pipe heat exchanger in a tropical air conditioning system

In an earlier paper (Yau, 2006. Application of a heat pipe heat exchanger to dehumidification enhancement in tropical HVAC systems—a baseline performance characteristics study. Int. J. Thermal Sci., accepted for publication), the baseline performance characteristics of the 8‐row wickless heat pipe heat exchanger (HPHX) were established for it being used in a vertical configuration under tropical climate conditions. The present paper covers the tests and simulation conducted on the same experimental HVAC system without the HPHX installed, thereby determining the enthalpy change for the air passing through the chilled water coil (CWC) alone (i.e. without the pre‐cooling or reheating effect of the HPHX). These experimental results, in comparison with those already obtained, would also allow an examination of how the reheat recovery with the 8‐row HPHX installed was influenced by the same key inlet parameters. The final results show that the enthalpy change with a HPHX installed for all cases examined are significantly higher than enthalpy change without a HPHX installed, demonstrating that the cooling capability of the CWC was enhanced by the HPHX. Copyright © 2006 John Wiley & Sons, Ltd.     

脉动热管用于空调排风余冷回收的试验研究

设计加工1台脉动热管式换热器,用于夏季工况空调排风的余冷回收。通过实验,分析了风速、新排风温差等因素对余冷回收效率的影响,以及两侧压力损失随风速的变化情况。结果表明,余冷回收效率随新风、排风温差增大而升高,随风速的增大而降低。该换热器具有一定的优势,但还需进一步改进结构,以提高其效率。     

热管技术在硫酸工业中的应用

硫酸工业中存在大量具有很高利用价值的余热资源，同时，也存在着高温、高粉尘、高腐蚀性等不利余热回收的因素。而热管技术给硫酸生产的余热利用的发展带来了新的活力。并且已经在很多方面取得了较大的成就。尤其是在耐低温腐蚀方面性能优越。文章主要介绍了热管技术在硫酸工业中应用的现状及前景，以及一些需要进一步探讨的问题。