热管技术在风洞工程中的应用初探

从风洞换热器的技术要求出发,简单介绍热管技术的优缺点。结合某型风洞换热器的设计（换热器结构参数）,对热管换热器与其他换热器进行比较,分析在风洞换热器中采用热管换热器的优势。     

浅谈几种换热器在石油化工行业的应用

近年来，随着我们石油化工行业的快速发展，换热器已经成为石油化工行业中一种常见的换热设施，在石油化工行业中得到广泛的应用。本文主要介绍了板式换热器、热管换热器和高通量换热器的特点和应用领域，并且详细阐述了高通量换热器的应用和发展。     

微通道换热器两相流分布研究现状与展望

两相流进入微通道换热器容易出现分布不均匀的现象,显著降低微通道换热器的性能.本文对微通道换热器两相流分布的研究动态进行了归纳与分析,主要介绍了微通道换热器中两相流分布特性的影响因素、提升微通道换热器中两相流分布均匀性的技术方案、微通道换热器两相流分布特性的仿真研究及相分离技术在微通道换热器中的应用;论述了两相流在微通道...     

板式换热器设计选型及使用中应注意的问题

板式换热器是一种紧凑高效换热器,在暖通空调制冷领域应用得越来越多。本文介绍了板式换热器的特点和应用场合,指出了板式换热器设计选型及使用中应注意的一些问题,对于板式换热器的设计选型人员及用户有一定的参考价值。     

浅析板式换热器运行维护及检修工艺要求

热交换器作为传热设备在工业中应用非常普及，其中，间壁式换热器用途最广泛，占总量的99％以上．而板式换热器又是间壁式换热器中使用较多的一种，了解板式换热器的分类、工作原理，正确操作使用，按照检修工艺要求进行设备检修，对延长换热器的使用寿命尤为重要。     

换热器腐蚀与防护的现状与展望分析

针对暖通空调领域相关的换热器应用中出现的问题,综述了换热器的在暖通空调领域的作用及其腐蚀的原因,以及目前国内外对换热器防腐措施的研究现状,以普通金属换热器与耐腐蚀高导塑料换热器为例,对比分析了采用耐腐蚀材料后对换热器换热性能的影响,以此为基础,分析了防腐涂层对换热器换热性能的影响,提出了换热器腐蚀与防护的发展与展望,认为塑料等耐腐蚀材料及采取防腐涂层在换热器防腐蚀方面具有很大的应用潜力,值得大力推广.     

套管换热器传热过程强化实验系统的研制

多套管式换热器结构简单,清洗、维修方便,易实现加工制作,提出多套管式换热器对套管换热器进行传热强化.在设定条件下编写程序,对多套管换热器进行优化设计,计算显示在相同条件下多套管式换热器与单套管换热器相比传热系数有较大的提高.系统中设置回热器,有效节约能源.该系统在有余热、废热可以利用的场合节能效果更加显著.     

结构特征对螺旋管换热器性能的影响

目的研究结构特征对螺旋管换热器换热性能的影响,为换热器设计和结构优化提供理论依据。方法在CFD软件Ansys的FLUENT模块中模拟螺旋管换热器内流体的流动换热过程。在相同边界条件下,不改变总换热面积,通过改变换热器的换热管直径和壳体长度,研究几何参数对换热性能的影响。通过对比单管单螺旋、单管双螺旋、双管双螺旋和内外双螺旋等4种不同缠绕方式换热器中流体的温度分布云图,研究螺旋管的结构对换热器换热性能的影响。结果保持总换热面积不变,减少换热器的管径,增大壳体的长度,都能有效提高换热效率。与单管单螺旋结构的换热器相比,单管双螺旋结构换热器的流体出口温度下降了9.74%,平行双螺旋结构换热器的出口温度下降了5.05%,内外双螺旋结构换热器的出口温度上升了10.11%。结论在螺旋管换热器的设计和优化过程中,可以通过减小换热管径,增大壳体长度,采用内外双螺旋结构,以实现提高传热效率的目的。     

全不锈钢钎焊换热器性能及应用

得益于全新的AlfaFusion钎焊技术,全不锈钢钎焊板式换热器AlfaNova开创了板式换热器应用的新领域,在和传统换热器的竞争中占据了优势.AlfaNova在各行各业中有很大的发展潜力,在制冷应用上已建立了坚固的桥头堡.     

螺旋板换热器防堵塞与防结垢可行性研究

螺旋板换热器在工业冷却设备中占有非常重要的地位，本文介绍了螺旋换热器的优缺点，重点对如何防止螺旋换热器堵塞与结垢问题做了可行性研究。     

填料间壁式低温换热器研究

换热器是低温设备的重要部件，研制高效换热器可以大大提高低温设备的性能。提供了换热器传热及流动阻力计算所需的部分实验数据，提出了以网络概念分析这种换热器传热过程的方法和建模方法。计算机解给出了完整的温度分布和效率，计算机模拟分析了诸项损失对换热器性能的影响。     

Characteristics of Air-Side Particulate Fouling Materials in Finned-Tube Heat Exchangers of Air Conditioners

ABSTRACT

Heat exchangers are used widely in residential, commercial, and industrial HVAC applications. Air-side particulate fouling in the heat exchangers of HVAC applications degrades the performance of cooling capacity, pressure drop across a heat exchanger, and indoor air quality. Indoor and outdoor air contaminants foul heat exchangers. The purpose of this study is to investigate the characteristics of the air-side particulate fouling materials in finned-tube heat exchangers of air conditioners. Air conditioners being used in the field such as inns, restaurants, and offices are collected in chronological order of use. The fouling materials attached on the evaporator heat exchangers consist of particulates and fibers. The particulates mainly originate from indoor dusts and the fibers are separated from clothes, bedclothes, papers, fur of pets, and so on. Typical fouling materials on the heat exchangers include fibers and dusts ranging from 6.6 to 20.9 μm in aerodynamic mean diameter.     

Characteristics of Air-Side Particulate Fouling Materials in Finned-Tube Heat Exchangers of Air Conditioners

Heat exchangers are used widely in residential, commercial, and industrial HVAC applications. Air-side particulate fouling in the heat exchangers of HVAC applications degrades the performance of cooling capacity, pressure drop across a heat exchanger, and indoor air quality. Indoor and outdoor air contaminants foul heat exchangers. The purpose of this study is to investigate the characteristics of the air-side particulate fouling materials in finned-tube heat exchangers of air conditioners. Air conditioners being used in the field such as inns, restaurants, and offices are collected in chronological order of use. The fouling materials attached on the evaporator heat exchangers consist of particulates and fibers. The particulates mainly originate from indoor dusts and the fibers are separated from clothes, bedclothes, papers, fur of pets, and so on. Typical fouling materials on the heat exchangers include fibers and dusts ranging from 6.6 to 20.9 μm in aerodynamic mean diameter.     

The Effect of Fouling on Low Temperature Heat Exchangers Performance Based on Exergy Analysis

By analyzing heat and exergy transfer processes of heat exchangers operating below the surrounding temperature, the effect of fouling on the low temperature heat exchangers performance has been conducted. Taking the parallel flow, counter flow, and cross flow low temperature heat exchangers as examples, the effects of some non-dimensional parameters on the low temperature heat exchangers performance under the fouling condition are given by introducing exergy transfer units number.     

微通道换热器在热泵型空调机组中的应用

将微通道换热器应用到北美市场典型的分体式热泵型空调机组中,并对采用微通道换热器的机组和采用铜管翅片式换热器的原机组的性能进行试验对比。试验结果表明,室内室外机均采用微通道换热器后,机组能力提高4％,制冷季节能效比（SEER）与制热季节能效系数（HSPF）分别提高2％和1％,换热器质量减轻44％,制冷剂充注量减少51％。平均结霜时间与原机组相比延长5％,平均除霜时间比原机组延长4％。此外,通过优化设计,制冷剂的分布更加均匀。对室外机微通道用换热器进行耐腐蚀性测试和压力交变疲劳测试,结果表明微通道换热器具有良好的可靠性。     

采用微通道换热器的热泵型空调器性能研究

基于对采用自行研制的微通道换热器的热泵型空调器的实测结果,计算分析采用微通道换热器的热泵型空调器的能效提升效果。结果表明,在保持换热面积一定的情况下,采用微通道换热器可以使热泵型空调器的制冷和制热的能效提高20％以上。     

受限空间中翅片管换热器的性能分析

受限空间翅片管换热器,是指由于总体框架尺寸的限制,部分结构参数被限定的换热器。为研究此类翅片管换热器的在换热传质时的不同特性,基于空调箱中的有限空间结构模型,建立适用于此类换热器计算的集总参数模型。利用二分迭代法求解的结果表明模型可高效精准地计算出翅片管换热器沿气流方向的排数,并且当任意工况参数或者结构参数发生变化时,此模型也可分析预测翅片管换热器的性能变化规律。利用实验数据对模型计算结果进行了对比验证:模型计算所得的各性能参数值与实验值吻合良好,其平均相对误差均小于2%,最大相对误差均小于8%。通过焓差实验台测定和分析翅片管换热器的制冷量和压降随工况参数和结构参数的变化规律,不仅优化换热器的设计,并为换热器运行调节方法的选取提供依据。     

A review on application of carbonaceous materials and carbon matrix composites for heat exchangers and heat sinks

Carbonaceous materials and carbon matrix composites (CAMCs) have potential to be used in heat exchangers and heat sinks for a number of thermal management applications related to HVAC&R systems, especially in high-temperature and corrosive environments. Recent developments in carbonaceous materials, such as new, natural graphite, carbon foam, carbon nanotubes, and CAMCs, open opportunities for new heat exchanger designs for compact and lightweight applications. The property data of various monolithic carbonaceous materials and CAMCs and their applications in liquid-to-liquid heat exchangers, liquid-to-gas heat exchangers, gas-to-gas heat exchangers and heat sinks are reviewed in this paper. While it is clear that these materials do hold promise for use in the construction of heat exchangers in different applications, additional research is still required in material properties, life-time behavior, structural design and manufacturing cost reduction.     

Development of compact heat exchangers for CO2 air-conditioning systems

Compact and lightweight heat exchangers are needed for motor vehicle air-conditioning systems and for several types of unitary equipment. The high-pressure natural refrigerant CO₂ is now being evaluated for use in such applications, and efficient heat exchangers are being developed and investigated. Carbon dioxide heat exchangers are designed for high refrigerant mass flux and use small-diameter tubes or extruded flat microchannel tubes. Refrigerant-side heat transfer coefficients are higher than with fluorocarbons, and reduced internal surface areas can therefore be tolerated. Both small-diameter mechanically expanded round-tube heat exchangers and brazed microchannel-type units have been built and tested successfully. Results show that compact heat exchangers optimized for CO₂ are very competitive with baseline HFC/HCFC units in terms of physical dimensions, exchanger mass and thermal performance. Smaller tube and manifold dimensions can give reduced size compared with HFC-134a equipment. The temperature approach between air inlet and refrigerant outlet is much lower in CO₂ gas coolers than in baseline system condensers of equal size and capacity, and the reduced refrigerant exit temperature has a marked influence on the coefficient of performance, Microchannel heat exchangers give the best overall efficiency. Refrigerant distribution in multiport manifolds and heat transfer tubes does not seem to be a problem.     

跨临界CO_2制冷系统中换热器结构的进展

换热器是制冷系统主要的传热部件,换热器的好坏直接影响系统的综合性能。从CO2的性质和跨临界系统的特点出发,介绍跨临界CO2制冷系统中换热器的结构型式的发展,指出发展微通道换热器是提高CO2制冷系统性能的必然。