平板型太阳能空气集热器的研究进展

太阳能空气集热器由于其在化工干燥等工程应用中的独特优势,已成为人们关注的焦点。由于空气介质自身性质,太阳能空气集热器的热性能普遍较低。为解决此问题,人们通过实验研究、数值模拟等方法对太阳能集热器的运行参数进行了优化,结构进行了改进。本文对已有国内太阳能空气集热器的研究进行了总结,分析太阳能空气集热器热性能的主要影响因素及提高热性能的主要途径,以及今后的发展趋势预测。     

平板太阳能空气集热器研究进展及应用

化石能源的过度消耗引发了严重的环境问题,利用可再生能源刻不容缓,太阳能作为一种理想能源,可利用性极强。平板太阳能空气集热器是一种将分散性、不稳定性强的太阳辐射能转换成热能的装置。近年来,国内外学者通过实验和数值模拟等方式对平板太阳能空气集热器进行了广泛研究。将主要介绍平板太阳能空气集热器的主要构成部件及其工作原理;基于对集热器部分评价指标及影响因素的分析,探讨了平板太阳能空气集热器性能优化途径;阐述了平板太阳能空气集热器低温热利用情况。针对集热器结构及建筑一体化等对平板太阳能空气集热器的后续发展提出展望。     

太阳能空气集热器采暖系统与蓄热系统在建筑中的应用

阐述太阳能空气集热器采暖系统与蓄热系统在建筑中的应用,并详述太阳能空气集热器采暖系统和蓄热系统结合的设计方案和运行原理。设计以空气集热器为集热系统,换热器、蓄热器和水箱为蓄热系统,既解决冬天集热器易冻堵的问题,又实现空气集热器在其他三季充分利用的问题。     

平板型太阳能空气集热器的应用分析

本文通过对平板型太阳能空气集热器的理论分析,介绍不同的空气流道厚度、空气流速对空气集热器的散热损失及瞬时效率的影响,为优化设计太阳能空气集热器提供一定的设计依据。     

太阳能建材干燥应用案例分析

针对太阳能在工业用热领域应用的兴起,以太阳能空气集热器在建材干燥过程中的应用为例,介绍太阳能空气集热系统设计和自动控制系统设计,并通过对系统运行效果的分析,阐述太阳能空气集热系统设计中应该注意的问题。     

日光温室专用多曲面槽式太阳能空气集热器热工性能试验研究

受到建筑材料热物性能的限制,透射在被动式日光温室北墙的太阳能对墙体内部层温度影响范围较浅,墙体的显热蓄热功能得不到充分利用。为此,基于提出的日光温室太阳能主-被动式三重结构相变蓄热墙体构筑方法,项目组团队研发了一种可直接安装在日光温室后墙顶部、体积小、安装方便且不占用耕地的日光温室专用多曲面槽式太阳能空气集热器,将该集热器加热的空气通过小型风机输送到墙体内部以提高中间厚重墙体的显热蓄热能力。为了探究所研制的多曲面槽式太阳能空气集热器热工性能,本研究搭建了关于该空气集热器热工性能试验台,重点研究了太阳辐照度、集热器内空气流速与进口温度、集热器保温性能及集热器长度等因素对其出口温度、集热量与集热效率等热工性能参数的影响规律。试验结果表明:所研制的多曲面槽式太阳能空气集热器管内空气流速宜为1.6~1.8 m/s,集热器单元的串接长度宜为16~18 m;晴好天气时,空气集热器的最大瞬时集热效率可高达56.7%,单位面积日累积集热量可达6.2 MJ/(m2·d)。     

太阳能空气采暖系统在夏季蓄热中的应用

阐述了太阳能空气集热器采暖系统在夏季蓄热中的应用,并详述了太阳能空气集热器采暖系统测试平台运行原理,对集热器系统、换热器系统热效率进行分析。     

太阳能热泵集热器的优化分析

对太阳能热泵集热器的优化分析进行了研究。通过试验的方法得出,太阳能空气集热器的吸热体具有与工质流动方向垂直的横向波纹,具有更高的效率。进出口接口为3组时,更有利于发挥集热器的效率。     

平板太阳能空气集热器的数值模拟研究

为评估4种不同类型平板太阳能空气集热器的热性能,本文建立了平板空气集热器的二维稳态CFD模型,对集热器内部空气的流动及热量的传递过程进行数值模拟,并获得了集热器热性能曲线。模拟结果表明,在标准流量下,双流道型(c型)平板空气集热器最大热效率达79.44%,热损系数为5.80,热效率高于其他3种类型的空气集热器,热性能最优。随着空气流量的增加,b型平板太阳能空气集热器由于具有较好的保温特性而表现出更优的集热性能。     

太阳能空气集热器除湿空调系统的研究与应用

本文主要介绍一种太阳能全玻璃真空管空气集热器的结构及特性,阐述了太阳能全玻璃真空管空气集热器与双级转轮除湿空调系统结合应用的运行原理。通过一个实际工程运行测试,表明了此种太阳能空气集热器除湿空调系统的运行特性。     

Study on the performance of a solar assisted air source heat pump system for building heating

This paper proposed a new solar assisted air source heat pump system with flexible operational modes to improve the performance of the heating system. A mathematical model was established on the solar assisted air source heat pump system for building heating with a heating capacity of 10 kW, and an air source heat pump unit was developed to validate the model. The effect of the solar collector area on the performance of the system running in Nanjing was studied. The results showed that the COP of the heat pump unit was enhanced with the increase of the solar radiation density during the typical sunny day in the heating season. In addition, the COP also increased in proportion to the solar collector area. Compared with the case when the solar collector area was 0 m², the COP increase of the heat pump and the energy-saving rate were 11.22% and 24% respectively when the solar collector area was 40 m². Meanwhile, the solar equivalent generation power efficiency could reach 11.8%.     

直通式真空管太阳能空气集热器的实验研究

研究了一种新型的直通式多根真空管空气集热器装置,包括直通式(两端开口)真空集热管和上下分集管。直通式真空管太阳能空气集热器安装在南墙的外面,室内空气进入集热器,加热后送回房间,实现了太阳能供暖,不需要风机或者水泵,简单可靠。搭建了试验台并测试了冬季供暖时的热性能。通过实验得出,该装置集热效率最高的点出现在14:00,集热效率为51%,其集热效率最低的点出现在16:00,集热效率为46%,全天的总效率为36.3%,具有较高的热效率。     

太阳能辅助供暖建筑能耗监测研究

本文以北京市平谷区1栋太阳能辅助供暖示范居住建筑为对象,对其供暖能耗进行了近1年的监测研究,计算得出该建筑冬季室内空气平均温度可达17℃、供暖季太阳能集热器效率为37.7%、太阳能贡献率为30.7%;太阳能辅助供暖系统回收期相对较长,但环境效益显著,年CO2减排量为4～4.7 t。在此基础上,针对太阳能辅助供暖系统提出了改进建议。     

The use of a heavy internal wall with a ventilated air gap to store solar energy and improve summer comfort in timber frame houses

This paper considers supplementary heating and cooling within timber frame houses. The transmission of solar energy to an internal concrete cavity wall by air is analyzed. The objective of this work was initially to study the dynamic insulation in timber frame houses. The initial studies showed that it is more efficient to recover solar energy rather than heat losses, which is the principle of dynamic insulation. Clearly, the thermal regulations lead to lower heat losses through walls by conduction. Due to these factors we have decided to study a wall with an integrated solar air collector and a heavy ventilated internal wall. This internal wall, which is used to store solar energy will allow the reduction of heat demand in winter and will improve thermal comfort in summer because thermal mass increases and ventilation during the night will cool the internal wall. We have selected a closed loop air circulation system because, with an air to air heat exchanger, it can be proved to be more effective and the risk of unhealthy air pollution is reduced because the flow of fresh air will not pass through the ventilated air gap. We are constructing an integrated air collector prototype.     

哨楼太阳能供暖设备设计与计算

对西北边疆某哨楼进行了建筑热工分析和计算,计算出围护结构的得热量和耗热量,对平板型空气集热器、卵石床蓄热器及其它系统设备进行了设计与计算,简述了太阳能供暖系统集热、蓄热、供暖的运行控制方法。     

Analysis on the optimum matching of collector and storage size of solar water heating systems in building space heating applications

The overall thermal performance of a solar water heating (SWH) system is significantly affected by the mismatch between the temporal distribution of solar radiation and the heating load. Therefore, a favorable correlation between the collector and storage size should be generated based on the dynamic characteristics of the system. This study focuses on the optimal matching of solar collector area with storage volume for an SWH system (with short-term heat storage capability) for a space heating application. A simplified model of an SWH system based on hourly energy flow is established. System control strategy is integrated into the model in a simple manner without sacrificing computing speed. Based on this model, the combined effect of collector area and storage volume on system thermal performance and economy is analyzed, and a simple procedure for determining the optimal system size is illustrated. A case study showed that for an SWH system utilized for space heating application, the optimized ratio between storage volume and collector area is dependent on the total collector area of the system, and is dominated by the requirement of overheating prevention. The minimum storage volume for a specific collector area that can prevent the storage tank from being overheated can be adopted as the optimum storage volume for that collector area. The optimum ratio between storage volume and collector area increases as the collector area increases. Therefore, a trade-off between heat collection and heat loss has to be made while attempting to increase solar fraction by improving collector area.     

Experimental investigation and theoretical analysis of solar heating and humidification system with desiccant rotor

In this paper, a solar heating system, which combines the technologies of evacuated tube solar air collector and rotary desiccant humidification together, has been configured, tested and modeled. The system mainly includes 15 m² solar air collectors and a desiccant air-conditioning unit. Two operation modes are designed, namely, direct solar heating mode and solar heating with desiccant humidification mode. Performance model of the system has been created in TRNSYS. The objective of this paper is to check the applicability of solar heating and evaluate the feasibility and potential of desiccant humidification for improving indoor thermal comfort. Experimental results show that the solar heating system can convert about 50% of the received solar radiation for space heating on a sunny day in winter and increases indoor temperature by about 10 °C. Compared with direct solar heating mode, solar heating with desiccant humidification can increase the fraction of the time within comfort region from about 10% to 20% for standalone solar heating and from about 30% to 60% for solar heating with auxiliary heater according to seasonal analysis. It is confirmed that solar heating with desiccant humidification is promising and worthwhile being applied to improving indoor thermal comfort in heating season.     

太阳能地板辐射供暖制冷系统模型仿真

近年来,我国北方地区新建住宅的采暖系统多数采用地板辐射供暖技术,而制冷系统仍采用传统的空调制冷技术,有必要对地板辐射制冷技术的应用进行研究,为此,针对一套实验用太阳房,搭建了太阳能地板辐射供暖制冷系统.通过计算确定了集热器面积、蓄热水箱体积、吸收式制冷机组的制冷量.利用TRNSYS仿真平台建立了系统仿真模型,并对控制策略进行了验证.仿真结果表明,该系统能有效地利用太阳能保持冬季室温18℃左右、夏季26℃左右的舒适温度.     

Collector characterisation and heat loss tests on a novel batch solar water heater with CPC reflector for households

ABSTRACT

This solar water-heating unit is an integration of the older concept of batch water heating with the modern trends in solar water-heating technologies i.e. incorporating a concentrator in the design. The concentrator used is the compound parabolic type (CPC) which is a non-imaging device having wider acceptance angle (64°) and supported on a wooden cradle, which comprises the two arms of the parabola. To suppress the heat loss, an air gap has been introduced in the arms of the CPC. The collector is a single larger diameter drum which serves both as an absorber and storage unit positioned at the focus of CPC. The parametric study of the model showed the thermal efficiency of the collector as high as 38% and maximum water temperature attained was 53°C. Heat loss tests performed on the collector on a 24-hr cycle period showed good long time performance estimates. The response time of collector computed and performance characteristic curve plotted to predict system response under any given conditions of solar insolation and ambient temperature.     

空气-太阳能-电能复合热源热泵型冷热水机组

研制了一种集空气源热泵、太阳能热水器和电热水器于一体的冷热水机组,可根据地理和气象条件从11种运行方案中优选节能方案,实现空调、热水供应和供暖;介绍了机组的构成和工作原理。该机组可减少换热环节和融霜次数,利用循环水显热蓄热,太阳能集热效率和系统供热效率较高,初投资和运行费用低于分别采用空气源热泵、太阳能集热器和电热水器的费用。