基于热回收的游泳池热泵除湿供暖系统

基于国内室内游泳馆能耗较高且大部分未设热回收装置的现状，讨论了利用热泵对游泳池供暖除湿的同时实现废热回收的系统设计方案以及回收效果，提出了利用太阳能辅助热泵运行的思想，并给出联合运行的设计方案。从能源利用的角度对二者进行了分析，并与常规的锅炉加冷水机组系统进行了经济性分析和比较，阐明将热泵应用于游泳池除湿供暖，不仅可以有效地节约能源，而且在经济上也是一个非常可行的方案。     

含液体除湿技术的分布式能源系统

本文介绍了液体除湿原理,对液体除湿技术在分布式能源系统中的应用进行了重点论述.华南地区春夏季相对湿度常常超过80%,分布式能源系统靠近用户需求侧面,在分布式能源系统中用液体除湿技术回收低品位余热会有明显优势.     

三维热管热回收应用于实验动物房性能比较

三维热管是利用相变传热原理实现热交换的装置,效率很高.针对实验动物房空调存在冷量和热量相互抵消以及全新风高能耗的问题,比较了热管的排风热回收、除湿热管、以及同时采用除湿热管和排风热回收系统的性能以及经济性.热回收可以在全年新风温度下任何时段运行;除湿热管只在夏季运行,但由于冷热量相互抵消的问题得以解决,运行期间大大节省...     

空调中分布型主动式热回收系统的分析

利用水或乙二醇对空调系统中的余热进行回收,加热空调系统进口新风,使除湿后的新风达到升温的目的。通过余热利用降低加热新风所需要的燃料,减少了二氧化碳的排放。分析讨论了瑞士Konvekta分布型主动式热回收产品的工作原理、使用效果及发展前景。     

复合式太阳能空调/热水综合系统研究

将常规压缩制冷技术与太阳能热水器技术、除湿冷却技术相结合 ,提出了一个复合式太阳能空调 热水系统方案 ,并进行了可行性分析。该系统不仅可以进行冷凝热回收 ,节能效果明显 ,而且对高热、高湿地区以及气候变化有很强的适应性     

某星级会所能源系统节能方案设计及探索

瑞仕华庭会所它是一所按国家绿色三星设计标识要求进行设计的节能型会所。文章对它的能源系统的节能方案设计作了详细的介绍。其能源系统涉及用于会所夏天制冷、冬天制热、三季泳池池水加热、四季生活热水制取的高效热回收型地源热泵系统,带热回收功能的集空调、除湿、泳池加温功能一体的三集一体机系统,以及与地源热泵联动的太阳能热水系统等综合节能和舒适性系统。     

空气压缩机吸气端除湿系统研究

为了降低空气压缩机吸气温湿度,以有效降低空气压缩机系统能耗,充分利用空压机余热,将膜分离技术、液体除湿技术和热泵技术相结合,采用中空纤维膜液体除湿装置进行空压机进气端除湿。结果表明:空压机系统的热负荷与湿负荷分开处理,避免了干燥系统的过渡冷却和再热的能量损失,采用空气压缩机吸气端除湿系统,不仅优化了空压机的进气参数,在降低空压机能耗的同时,为空压机创造了良好的运行环境,降低了空压机的日常运行、维护成本。     

太阳能溶液除湿系统再生器的实验研究

结合工程实例进行了太阳能溶液除湿系统除湿溶液再生实验,研究了除湿溶液再生过程的热质交换特性,得到了不同溶液入口参数下再生器内部各测点温度,揭示了不同空气和溶液入口参数对出口溶液浓度的影响和填料对再生器热质交换的影响。文章可为太阳能溶液除湿系统再生器的设计提供依据。     

太阳能与地源热泵供应生活热水方案比较

对太阳能热水系统和地源热泵热回收热水系统进行分析,并通过某一实际工程对两系统能耗进行了对比,最后得到对于南京地区地源热泵热回收制热水系统更节能。为合理选择热水供应系统提供一定的依据。     

新型空调冷凝热回收方法和装置

对冷水机组的热回收系统原理进行了分析,提出了一种将冷凝热回收用来加热生活热水的方法和装置,并对该系统使用的经济性进行了分析,指出利用热回收系统可有效地利用能源.     

利用汽车发动机余热的溴化锂吸收式制冷研究

根据现有汽车空调的制冷系统和发动机冷却水及排气系统的结构特点,结合溴化锂吸收式制冷系统的工作原理,提出将汽车排气管和发动机冷却水箱进行结构改造作为溴化锂吸收式制冷系统的发生器,代替传统的汽车空调的制冷和采暖系统及发动机冷却系统。并对该溴化锂制冷系统进行了热力计算和传热面积的计算,计算结果表明,溴化锂制冷系统充分利用了废气余热和冷却水余热,减少了汽车油耗,并且改造后的排气热交换器和冷却水箱传热面积小,结构简单紧凑。     

太阳能吸收式空调系统的经济性分析

针对一个特定的对象,进行了太阳能吸收式空调系统寿命周期内的模拟计算及影响因素的分析,结果表明：（1）单纯太阳能空调（无采暖与热水供应）的经济性很差,太阳能空调与供热的复合系统的经济性要优于单纯的太阳能空调系统;（2）太阳能采暖与空调的复合系统,采暖与供冷的负荷比对系统的经济性有很大影响,即使在最佳的负荷比时仍无法和常规的系统竞争;（3）太阳能与生活热水系统的负荷系统中,热水负荷所占比重越大,经济性越好,当太阳能空调使用生活热水系统夏季多余的热量时,太阳能空调系统经济上可以和天然气锅炉＋电动制冷机竞争,并具有很好的节能性和环境效益。     

Solar absorption air conditioning alternatives

The relative advantages of a single-stage, lithium bromide-water absorption air conditioner heated from a flat-plate solar collector are compared theoretically to those for an ammonia-water system, and the lithium bromide system is selected as the preferred one. Double-stage absorption systems with their improved performance are described and are shown theoretically to require generator temperatures that are too great to make them attractive for use with flat-plate collectors. Dual, series-connected systems which require no cooling tower for heat rejection are shown by analysis to have a low coefficient of performance. Systems utilizing refrigerant storage and a heat rejection buffer between a cooling tower and the absorber and condenser are discussed along with the computer simulation describing them. They are shown to require smaller cooling towers than conventional units. Operation with an air heat exchanger rather than the cooling tower in such a system is shown to yield acceptable system performance with a small reduction in the fraction of the cooling load which can be met with solar energy.     

基于CFD分析的单缸风冷柴油机冷却系统设计与研究

以X170F单缸风冷柴油机为研究对象,运用CFD分析软件SC/Tetra对其冷却系统进行了三维流动的数值模拟,并对原冷却系统结构进行了优化设计与计算.计算结果表明:改进后的结构增大了进入气缸盖高热负荷区域的冷却风量,冷却流场分布更加合理,改善了气缸盖底部的冷却效果.     

间接空冷机组空冷塔塔群内空气流动及传热性能研究

由于具有巨大的节水优势,间接空冷机组在我国富煤少水区域得到广泛应用。研究环境风对间接空冷系统的影响机理对指导电厂运行具有重要意义。以某电厂间接空冷机组为基础,构建水平布置散热器的空冷塔群物理和数学模型,通过数值模拟方法分析环境风对塔内空气流场及空冷散热器换热性能的影响。结果表明:环境风对空冷系统塔内空气流场影响较大,进而影响空冷散热器的散热性能。随着风速的增加,空冷塔的换热性能不断恶化。在临界风速时额定负荷下,下游空冷塔换热量比上游空冷塔减少2.5%。     

燃气轮机空气冷却系统建模及计算分析

本文以某型燃气轮机透平叶片的空气冷却系统为研究对象。在分析叶片的内部冷却方式、结构及冷却空气流路构成的基础上,将空气冷却系统模化为由大量不同的通流单元以串连或分支方式组成的复杂网络系统。选用适当的经验关系式或试验关联式计算空气流经各通流单元的压力损失与换热量,建立了描述冷却空气流动与换热特性的流量方程组、压力方程组和温度方程组。采用逐步简化空气冷却系统的方式,求解空气冷却系统内流量的分配。采用以改进并修正的高斯消去法为基础的一种稳定的大型稀疏矩阵线性方程组解法来求解空气冷却系统内空气的压力与温度分布。可以计算得到各流路的压力、温度和流量的分布等参数。     

Improved underground heat exchanger by using no-dig method for space heating and cooling

This paper describes experiments and analyses on an improved underground heat exchanger by using a no-dig method for the purpose of the cost reduction of a space heating and cooling system using underground thermal energy. First, the improved underground heat exchanger was installed on the campus of Hokkaido University, and it was shown that a ground source heat pump system utilizing the heat exchanger was sufficient for space heating and cooling. Second, evaluation program of the heat exchanger was developed, and the program was verified to give good predictions by comparing with experimental results. As a result of system simulations, an energy reduction for a system installation relative to a conventional vertical earth heat exchanger reached 78%. The primary energy reduction rate including the system installation and operation relative to a typical air source heat pump was 29%.     

Cooling potential of ventilated PV façade and solar air heaters combined with a desiccant cooling machine

Thermal energy collected from a PV-solar air heating system is being used to provide cooling for the Mataro Library, near Barcelona. The system is designed to utilise surplus heat available from the ventilated PV facade and PV shed elements during the summer season to provide building cooling. A desiccant cooling machine was installed on the library roof with an additional solar air collector and connected to the existing ventilated PV façade and PV sheds. The desiccant cooling cycle is a novel open heat driven system that can be used to condition the air supplied to the building interior. Cooling power is supplied to the room space within the building by evaporative cooling of the fresh air supply, and the solar heat from the PV-solar air heating system provides the necessary regeneration air temperature for the desiccant machine. This paper describes the system and gives the main technical details. The cooling performance of the solar powered desiccant cooling system is evaluated by the detailed modelling of the complete cooling process. It is shown that air temperature level of the PV-solar air heating system of 70 °C or more can be efficiently used to regenerate the sorption wheel in the desiccant cooling machine. A solar fraction of 75% can be achieved by such an innovative system and the average COP of the cooling machine over the summer season is approximate 0.518.     

Energy and thermal performance of heat pipe/cooling coil systems in hot‐humid climates

The objective of this study is to evaluate the magnitude of reduction in cooling and reheat energy when a heat pipe system is incorporated with the cooling coil of an air‐conditioning system. The heat pipe/cooling coil (HP/CC) system performance is determined by several parameters that are related to both the air‐conditioner cooling coil and the heat pipe physical characteristics as well as the condition of the air entering and leaving the system. In order to appreciate the impact of these parameters and their relative influence on energy consumption and the required indoor air conditions, a simple mathematical model incorporating the parameters of HP/CC is formulated. The model describes the overall system performance at varying entering and leaving air conditions. The model is then applied to a case study as an example of an application to investigate these relationships for a better understanding of the system behaviour and the influencing design parameters. It is evident that due to the coupling nature of the heat pipe and the cooling coil actions, a unique system performance will be obtained for each combination of heat pipe effectiveness and cooling coil by‐pass factor. A proper selection of both the heat pipe and the cooling coil characteristics is found to be necessary for a satisfactory performance under the given operating conditions. Copyright © 2000 John Wiley & Sons, Ltd.     

Convective heat transfer coefficients evaluation for a portable forced air tunnel

The objective of this work was the determination of the convective heat transfer coefficient in order to evaluate an experimental portable forced-air freezing tunnel and work on comparative studies with air exhausting and blowing. The heat transfer coefficients of the cooling air and the product were analyzed during freezing process. Convective coefficient results were higher for air exhaustion than air blowing in every part of the batch, except for the upper layer of products, where the cooling air of the chamber was directly in contact with the product. These results, with the temperature analysis obtained, indicated that the air circulation around the samples, as well as the heat transfer, improved with the use of the portable system, and had better results for the exhaustion compared to the blowing process.