聚光连续型高效智能吸附式空调及其强化传热设计浅析

基于双床吸附连续制冷的理论,提出了一种聚光连续型高效智能吸附式空调系统,将聚光光伏技术和吸附式制冷技术相结合,形成冷、热、电联产一体化的新思路。系统设计围绕连续回热型的吸附制冷循环、太阳能聚光器、光伏电池板3个重要方面,提出太阳能3个层次优化利用,进一步强化传热和提高能源利用率,为丰富发展吸附式空调系统理论、低成本高效利用太阳能提供技术支持。     

太阳能吸附式制冷系统的研究现状与发展前景

从工作原理、工质对的选择、吸附床的设计、经济性分析及应用几方面,对太阳能吸附式制冷系统进行了详细的综述性分析。由于太阳能转换率低和集热器价格昂贵,目前太阳能吸附式制冷系统存在的主要问题是制冷性能较低、初投资成本大,所以,提高制冷性能、降低成本是太阳能吸附式制冷系统实现商业化和产业化的关键所在。通过选取合适的工质对、强化吸附床的传热传质性能,可有效提高系统的制冷系数,推进其工业化应用。     

太阳能固体吸附式制冷循环的吸附床内传热传质耦合计算

用多孔介质理论方法分析了太阳能固体吸式制冷循环的吸附床并相应地按多孔介质的质量、动量、能量传递过程建立了太阳能固体吸附式制冷循环吸附床内传热传质耦合求解的数学模型。用本文建立的方法,可对吸附式制冷循环的吸附床进行了热动力学分析与计算,并可进一步用于系统的优化设计中。     

太阳能固体吸附式制冷吸附床的设计

描述了固体吸附式制冷系统中吸附床的作用和功能,比较分析了现有太阳能固体吸附式制冷装置的吸附床。通过两种吸附床装置的具体分析,提出了合理设计太阳能吸附床装置的途径。     

冷管型太阳能制冷系统

太阳能吸附式制冷作为一种绿色环保型的制冷技术具有良好的应用前景。本文分析了一种吸附床可直接吸收太阳能的、自身完成集热与制冷的玻璃管型太阳能吸附式制冷管,并介绍了以该冷管为基础的太阳能制冷系统。     

翅片管整体传热传质强化的太阳能吸附式制冷系统性能研究

针对太阳能金属管式吸附床传热传质存在的不足,采用增加吸附管传热翅片及增大传质通道的方法,提出一种整体强化传热传质的新型翅片管设计方法,分别设计两种结构形式的太阳能吸附集热器,建立采用活性炭-甲醇为工质对的太阳能吸附式制冷系统。实验表明,采用吸附管横放、两端分别连接汇流导管形式的太阳能翅片管式吸附集热床可明显改善系统制冷性能,其吸附制冷效率是采用吸附管纵向放置、从翅片管上部通过导管连接到汇流导管的吸附床的太阳能吸附式制冷系统的3.56倍。采用性能较好的吸附床可构建太阳能吸附式制冷系统,并在晴朗无云、晴天有时有云、多云辐射强烈及多云辐射微弱4种典型天气情况下,进行吸附制冷系统运行特性和制冷性能实验研究,结果表明前三种天气条件下吸附床维持较高温度(≥80℃)超过4 h,制冷剂解吸较为充分,均产生制冰效果,制冷效率较高,COP最高达0.129;在多云太阳辐射微弱天气条件下,虽然吸附床维持在较高温度(≥80℃)时间不到2 h,但COP可达0.039,体现出该翅片管式吸附床良好的天气适应性。     

太阳能固体吸附式制冰机热动力学性能分析模型及实验

分析了太阳能固体吸附式制冷装置中吸会床的传热传质计算过程,给出了求解模型的具体方法,运用数值传热学的方法,计算了在一定日照国徽能量条件下,系统装置的吸附床内的温度场分布,实验表明,所建立的模型能对太阳能固体吸附式制冷装置进行了性能动态模拟,为系统装置的优化设计提供了参考。     

固体吸附式制冷的关键技术研究

描述吸附容量的Ｄ－Ａ方程、吸附床内的传热传质、新型热力循环的潜力与可行性、吸附系统的技术经济性和优化控制、实际吸附循环理论以及双效／多效吸附式制冷等是吸附式制冷尚需进行研究的基础课题。本文对固体吸附式制冷机的关键技术进行了探讨。     

对太阳能固体吸附式制冷技术的应用分析

本文介绍了太阳能作为驱动热源的固体吸附式制冷系统的基本组成,依据Polnyi吸附势理论和D-R方程对系统的吸附一解吸过程进行了比较准确的描述,着重对固体吸附式制冷技术的实际应用技术分析。主要必须考虑：在对吸附系统的研究中引入“非平衡吸附”概述进行了动态吸附速度的测定,尽可能地选用带有吸收膜的集热器,以及改善吸附床的传热传质性能等。     

太阳能冷管的研究及其进展

太阳能冷管以沸石分子筛—水为工质对，在一根玻璃管内完成吸附式制冷循环，一根冷管即为一个制冷单元，成功地解决了太阳能吸附式制冷技术难以转化为成果的问题。本文综述了作者近几年来对太阳能冷管首创性提出，以及其结构性能的研制和改进情况。采用真空集热方式和选择性涂层加强冷管对太阳能的吸收，采用整体固化复合吸附剂提高吸附床的吸附和脱附性能。本文还介绍了已制作的三代太阳能冷管型制冷系统的试验样机，在单一提供制冷的基础上，提出了既可以制冷又可以供热水的多功能太阳能冷管。目前，实验结果表明，最新的多功能太阳能冷管COP可达0．268，太阳能制冷与供热的总效率可达87．7％。     

Design and performance of a solar-powered air-conditioning system in a green building

A solar-powered adsorption air-conditioning system was designed and installed in the green building of Shanghai Research Institute of Building Science. The system contained 150 m² solar collectors and two adsorption chillers with nominal refrigeration capacity of 8.5 kW. Based on performance characteristics of the adsorption chiller, the operation mode of the solar-powered air-conditioning system was optimized by maintaining a phase shift of 540 s between the two adsorption chillers. Thereafter, the whole system realized stable operation by the balance of heat consumption and refrigeration output. From June to August of 2005, the solar-powered air-conditioning system continuously ran between 9:00 and 17:00. The operation performance of the system under representative working condition showed that the average refrigeration output of the solar-powered air-conditioning system was 15.3 kW during an 8 h operation and the maximum value exceeded 20 kW. Solar fraction for the system in summer was 71.7%, which corresponded to the designed cooling load (15 kW). Compared with the ambient temperature, it was deduced that solar radiant intensity had a more distinct influence on the performance of solar-powered air-conditioning system.     

降低吸附式制冷系统驱动热源温度的研究进展

吸附式制冷是一种环境友好的制冷方式,可以利用低品位热能提供冷量,因此具有重要的节能意义。目前,吸附式制冷技术在太阳能热利用、工业余热利用等中低温余热领域已有应用,但对低于60℃热源的利用实例较少。降低吸附式制冷系统所需的驱动热源温度是扩大吸附式制冷系统使用范围的重要手段。吸附式制冷系统所需驱动热源温度与系统循环方式、吸附剂性能等因素密切相关。从二级/多级吸附式制冷循环、表面酸性强度与孔结构等影响吸附剂再生温度方面阐述了降低吸附式制冷系统驱动热源温度技术的国内外研究现状。分析结果显示,多级循环吸附式制冷系统可以降低装置的驱动热源温度,但装置结构较为复杂;低再生温度吸附剂能够拓宽吸附式制冷装置的驱动热源温度范围,吸附剂的脱附温度与表面极性、酸性、孔结构等参数有关,对吸附剂进行改性,吸附剂极性弱、酸性低的表面特性有利于降低脱附温度。另外,还介绍了数据中心余热驱动的吸附式制冷技术。开展降低吸附式制冷系统驱动热源温度的研究为低温余热高效利用提供了技术参考。     

Review of solar sorption refrigeration technologies: Development and applications

In this paper, a review of the research state of art of the solar sorption (absorption and adsorption) refrigeration technologies is presented. After an introduction of basic principles, the development history and recent progress in solar sorption refrigeration technologies are reported. The application areas of these technologies are categorized by cooling temperature demand. It shows that solar-powered sorption refrigeration technologies are attractive alternatives that not only can serve the needs for air-conditioning, refrigeration, ice making and congelation purposes, but also can meet demand for energy conservation and environment protection. However, a lot of research work still needs to be done for large-scale applications in industry and for the replacement of conventional refrigeration machines.     

Development of adsorption air-conditioning technology using modified activated carbon – A review

Adsorption air-conditioning technology has attracted much attention recently due to its environmental friendly property. Some successes have been reported in the literature on the adsorption technology for air-conditioning applications. This paper presents an overview of the researches which had been carried out on adsorption refrigeration system with the commonly used adsorbent and adsorbate working pairs, solar adsorption refrigeration and adsorption technologies in automobile. Activated carbon has been widely used as the adsorbent in adsorption refrigeration system. However, one of the bottlenecks which prevent the improvement of the adsorption refrigeration technology using activated carbon is the use of the readily available commercial activated carbon without prior treatment, which has resulted in relatively lower performance as compared to the conventional absorption and vapour compression technologies. Various modification methods on activated carbon are thus discussed in this paper for future development and improvement of adsorption air-conditioning system.     

A study of thermal decomposition of methanol in solar powered adsorption refrigeration systems

To study the long-term performance reliability of a solar powered carbon/methanol ice maker, an investigation of thermal decomposition of methanol on the alloy's surface under solid adsorption refrigeration conditions has been carried out at Monash University. The indoor simulation showed that the thermal decomposition of methanol did occur in the normal solar powered adsorption refrigeration system. Dimethyl-ether and methoxymethyl methyl ether, etc. were found in the decomposition products. The rate of the decomposition depends on the presence of various alloys. These decomposition products (unwanted gases) may be one of the main reasons for the diminishing performance of the solar ice maker. The impact of the unwanted gases on the ideal solar powered solid adsorption refrigeration cycle is also discussed in this paper.     

小型固体吸附式太阳能空调装置的实验研究

根据小型太阳能空调装置的要求和特点,对固体吸附式太阳能空调系统进行了实验研究。通过对装置运行工况的具体分析,选择硅胶水作为吸附剂与制冷工质,介绍了集热／再生器、空冷冷凝器和蒸发器的结构设计。在此基础上,建立了小型固体吸附式太阳能空调实验装置,并对整个系统的运行性能进行了一系列的实验研究。结果表明,采用硅胶水工质的小型吸附式太阳能空调装置进行间歇式空调,在技术上是可行的,为进一步研究性能的优化提供了依据。     

Modelling and performance study of a continuous adsorption refrigeration system driven by parabolic trough solar collector

This article suggests a numerical study of a continuous adsorption refrigeration system consisting of two adsorbent beds and powered by parabolic trough solar collector (PTC). Activated carbon as adsorbent and ammonia as refrigerant are selected. A predictive model accounting for heat balance in the solar collector components and instantaneous heat and mass transfer in adsorbent bed is presented. The validity of the theoretical model has been tested by comparison with experimental data of the temperature evolution within the adsorber during isosteric heating phase. A good agreement is obtained. The system performance is assessed in terms of specific cooling power (SCP), refrigeration cycle COP (COP_cycle) and solar coefficient of performance (COP_s), which were evaluated by a cycle simulation computer program. The temperature, pressure and adsorbed mass profiles in the two adsorbers have been shown. The influences of some important operating and design parameters on the system performance have been analyzed.The study has put in evidence the ability of such a system to achieve a promising performance and to overcome the intermittence of the adsorption refrigeration systems driven by solar energy. Under the climatic conditions of daily solar radiation being about 14 MJ per 0.8 m² (17.5 MJ/m²) and operating conditions of evaporating temperature, T_ev = 0 °C, condensing temperature, T_con = 30 °C and heat source temperature of 100 °C, the results indicate that the system could achieve a SCP of the order of 104 W/kg, a refrigeration cycle COP of 0.43, and it could produce a daily useful cooling of 2515 kJ per 0.8 m² of collector area, while its gross solar COP could reach 0.18.     

Review paper on solar-powered air-conditioning through adsorption route

Solar-power based sorption refrigeration systems do not suffer from the problem of greenhouse gas emission and release of ozone layer depleting substances as in the case of conventional vapour compression refrigeration system. Absorption based systems are already commercially available while adsorption based systems are still in research and development stage. Progress and development of solar-powered adsorption cooling systems have been described in this paper. Factors preventing commercialization of this system have been discussed in detail. The state of the ongoing research, to make the system more efficient and cost effective, has been presented.     

一种新型太阳能冷热联产系统的设计

基于节能环保的理念,设计了一种新型太阳能冷热联产系统。该系统利用太阳能作为能量来源,半导体制冷片作为制冷元件,同时回收系统的废热,整套系统的能源利用效率较高。以能量平衡与传热理论为基础,结合理论计算和数值模拟,证明该系统可实现冷热联产的功能,制冷能效COP为0.7,热量利用效率达73.5%。