某空调用组合式换热器的节能效果分析

本文介绍作者研制的空调用组合式换热器,并对其进行了热经济性分析,阐明了其节能的原因。     

空调用液 气式换热器的强化换热分析与主要节能强化措施

<正> 本文回顾了暖通空调用液——气式换热器的基本原理,对强化换热的机理作了分析,并探讨了几种主要的强化换热手段。对设计换热器有一定的参考价值。     

某空调用组合式换热器的节能效益分析

本文介绍作者研制的空调用组合式换热器,并对其进行了热经济性分析,阐明了其节能的原因。     

地源热泵空调系统及盘管换热的模拟试验

比较了土壤源热泵和水源热泵的特点。为弥补上述热泵的不足,设计了一种新型的风冷水源空调系统,并进行了盘管换热的模拟试验。试验结果表明,此盘管结构设计合理,可适用于风冷水源空调换热系统。     

风机盘管的节能与智能化研究

通过对当前行业内卧式暗装风机盘管机组技术现状及存在的问题分析,提出改进创新的建议,其主要特点是:采用扁管换热器、无刷直流电机系统,分工况变转速控制及恒温智能控制等运行模式。通过对主要部件的合理整合及对运行情况的智能控制,降低机组运行能耗与运行噪声,解决传统风机盘管机组运行不节能,控制不灵活,智能化水平不足及舒适度不高等问题。     

郑州某大酒店空调系统设计

对郑州某酒店冷冻站的室内空调系统进行了设计。结合建筑本身特点及空调区功能的要求,对中餐厅、西餐厅采用全空气一次回风系统,对KTV包间、客房采用风机盘管系统,气流组织采用侧送下回方式。对建筑冷、热负荷进行了精确计算,结果表明夏季总冷负荷为378·71kW,冬季热负荷为90·7kW。经过近2年的运行,效果良好,达到设计要求。     

浮动盘管换热器和U型管换热器在建筑热水中的应用

在建筑热水供应设备中,有浮动盘管换热器、U型管换热器、螺旋管换热器等种类。本文重点对浮动盘管换热器、U型管换热器的性能、特点进行分析和比对。1.浮动盘管换热器浮动盘管换热器是一种间接换热器,传热部分采用铜管,把传热管做成螺旋状浮动置于壳体内,所以称为浮动盘管。由于该换热器的传热管在壳体内,水流过时可上下浮动     

风机盘管冷量影响因素显著性分析及其冷量计量方法

本文利用正交试验的方差分析方法讨论了风机盘管各因素对其冷量的影响程度,在此基础上阐述了一种针对定流量风机盘管集中空调系统的冷量计量方法--风侧冷量计量法的基本原理,并对该方法的计量精度进行了分析。     

二甲醚气化系统中螺旋盘管换热器的理论设计

基于二甲醚盘管换热器的理论计算,获得了换热器的换热量、换热面积以及盘管的圈数.研究结果为大规模气化二甲醚提供了理论依据.     

某五星级酒店空调系统热回收节能分析

在空调设计过程中利用建筑能耗模拟软件DeST对某五星级酒店的空调负荷构成进行分析,得出酒店建筑的负荷很大一部分来源于新风负荷,通过设置全热回收装置回收排风能量,以提高能量的利用率.     

螺旋盘管式换热器管板的分析设计

螺旋盘管式换热器的设计标准为ASMEⅧ-1-2010,本文对管板组件进行局部应力分析,按照ASMEⅧ-2进行分析评定。按照标准的规定将管板简化成当量实心圆平板,开孔区设置不同的等效参数。管板组件的应力分析采用两种方法进行,分别为：基于弹性应力分析的应力分类法与基于塑性失效准则的极限载荷分析法。本文旨在促进弹性分析法与极限载荷分析法的联合使用。     

湿法烟气脱硫系统的烟气换热器设置分析

通过对上海地区燃煤电厂湿法烟气脱硫系统安装和不安装烟气换热器(GGH)的运行分析,证实了安装GGH后的烟囱腐蚀,明显低于无GGH烟囱,尤其是针对GGH发生结垢、堵塞和腐蚀等问题采取的六大技术措施,能够达到环保考核要求,同时论述了脱硫系统取消GGH后,会给周边环境和生产运行安全带来隐患。为此,结合国家环保政策,提请各燃煤电厂在建设脱硫系统时,不应盲目取消脱硫系统的GGH装置。     

换热站循环系统节能增效

我国东北地区冬季供暧每年耗费大量能源。在全世界能源不断减少,供热成本不断提升情况下,国家相关部门节能政策要求降低不可再生能源消耗,成为我们迫切需要解决的最大问题,文中从加强换热站设备运行管理,更新循环泵的选择理念,改变循环泵工作周期,控制循环水量、扬程和压力。通过一系列的措施最大限度地降低供热成本即水、电的消耗量。     

Analysis of a Parallel-Flow Heat Exchanger with a Heat Source

In this work, a modified analysis of a parallel-flow plate heat exchanger that takes into account a volumetrically uniform heat source in the hot fluid is presented. New expressions for the number of transfer units (NTU) and effectiveness of the heat exchanger are derived. These expressions are verified against the conventional effectiveness–NTU relations in the limit of zero heat source rate. This situation is of interest in applications such as the ammonia–water absorption absorber heat exchanger where a heat source is generated in the solution side. The model studies two cases based on the minimum and maximum heat capacities of the hot fluid. The results show that the number of transfer units and the effectiveness of the heat exchanger are the same for both cases. The analysis is applied to the absorber heat exchanger. Expressions of effectiveness and number of transfer units of a counterflow heat exchanger with a heat source in the hot fluid stream are also given from minimum and maximum heat capacities points of view.     

Heat Transfer and Exergy Analysis of a Spiral Heat Exchanger

The heat transfer effectiveness of a countercurrent spiral heat exchanger is expressed as a function of number of transfer units, ratio of flow capacity rates, number of spiral turns, and dimensionless start-point angle of spiral (dimensionless angular angle of the start point of a spiral curve constituting the solid wall of the heat exchanger). The heat transfer effectiveness is weakly dependent on the dimensionless start-point angle of spiral, but moderately increases with the number of spiral turns. As the number of spiral turns is larger than 20, the heat transfer effectiveness of the spiral heat exchanger approaches that of a counterflow heat exchanger. The heat transfer effectiveness of the spiral heat exchanger has a maximum. The optimum number of transfer units at the maximum heat transfer effectiveness increases with the number of spiral turns, whereas it increases with a decrease of the ratio of flow capacity rates. In the second-law analysis, an optimum hot flow-to-cold flow capacity-rate ratio is found. For obtaining a large net recovered exergy rate, the spiral heat exchanger needs to possess a large number of transfer units (greater than 2.0) and operate at a near balanced-flow condition. In addition, a small consumed mechanical power is demanded.     

换热器系统的热力学性能评价

引入可用能损率这一指标对串联组合的换热器系统的热力学性能进行了 分析和评价,得到了换热器系统可用能损率的一般计算式,讨论了换热器系统的总流动趋势、冷热流体热容量流率比、传热单元数及单台换热器的流型、传热有效度和数目等对换热器系统可用能损率的影响。     

新模式热电联产供热系统用热终端高效换热器的分析

首次为新模式热电联产低品位供热系统提出了一种用户端高效换热器－新型风机盘管,并对此从技术性、节能发生和经济性等方面进行了探讨和分析,旨在为新模式热电联产供热工程的实施提供理论依据。     

过冷却技术提高制冷效率的节能效果浅析

介绍了制冷剂过冷技术应用于普通空气调节系统,可提高制冷效率,挖掘节能潜力。应用过冷却技术提高制冷效率,即通过增加外部过冷却装置,在直接膨胀式蒸汽压缩空气调节装置中,具有显著的节能效果。对该技术原理和应用状况进行分析,为我国同类型中央空调系统的节能运行及改造提供一种新的思路和方案,对建筑节能改造具有积极的推进作用。     

Heat Transfer Enhancement for Heat Exchanger Network Retrofit

Heat exchanger networks (HEN) play important roles in a chemical plant. In a plant lifetime, it may be required to retrofit a HEN several times in order to improve the energy efficiency or to accommodate the increase in throughput. The network pinch method developed by Asante and Zhu [1] can identify bottlenecks, which limit the increase in heat recovery for an existing HEN and also indicate promising structure changes to overcome the bottlenecks. As a result of HEN retrofit, additional surface area is required for some heat exchangers. There are a number of options to provide additional area, such as installing new shells or new units, adding new tubes to an existing bundle, etc. If heat transfer enhancement (HTE) is applied, additional area can be reduced significantly. This can result in a great reduction in capital cost and implementation time for modifications. However, in practice, heat transfer enhancement techniques have not been applied extensively, particularly in the petroleum refining industry. Several main aspects need to be addressed when HTE is taken into consideration for HEN retrofit. The first is how to determine which heat exchangers are suitable to apply HTE in the network and the second issue is to determine what level of augmentation of heat transfer performances is required. The last is about how to select a particular enhancement technique that can fulfil the enhancement requirement. A new strategy for applying HTE in HEN retrofit at the conceptual design stage has been developed. The above issues can be addressed properly by this new method. The new procedure is demonstrated using a case study.