太阳能墙式热管集热蓄热装置

本实用新型是一种用集热热管和蓄热水箱相结合,并且使水箱与房屋墙壁有特殊接触的为房屋建筑供暖和供热水装置。该装置以热管做为太阳能热转换的主要部件,同时,集热部分由密闭式透明罩层、吸热管板、保温墙及采光窗组成,蓄热部分由带有可拆     

双热源太阳能热泵在住宅建筑中的应用研究

提出一种新型的太阳能-空气复合热泵系统,并对其运行策略进行介绍。系统同时满足建筑物室内供暖、制冷及热水需求,具有较高的综合利用性能。通过进行太阳能供暖实验,分析太阳能集热、蓄热系统对室内供暖保证率的影响。     

生态村分布式供能系统分析

针对广大农村沼气和太阳能利用率低的问题,提出了一种生物质能与太阳能互补综合利用的生态村分布式供能系统。该系统将太阳能光伏发电、太阳能光热转换、生物质气化与常规燃气发电整合,实现生物质能与太阳能的供电、供暖、制冷、供燃气和供热水五联产,可有效缓解新农村含碳能源利用带来的环境和安全性问题,有效解决生物质利用效率低和太阳能利用不稳定等技术瓶颈问题。以唐山市沙河驿镇唐庄子村为例,优化生态村分布式供能系统方案,其研究结果可为生态村的建设提供技术支撑。     

太阳能化学蓄热及其近展

太阳能热利用系统可分为三大部分:集热、蓄热和供热,如图1所示。其中,供热部分在技术上已不存在问题。对于太阳能利用的研究,开始集中于集热装置,而开展蓄热部分的研究相对较晚。目前看来,     

太阳能空调制冷技术

太阳能用于空调制冷,最大的优点是季节匹配性好.利用太阳能实现制冷效应有多种技术途径,其中将太阳辐射转变为热能,通过热能实现制冷的方式最具有应用前景,特点是能够实现太阳能供热、空调综合利用,全年综合转换效率高.针对常见的太阳能热能转换制冷空调方式,从太阳能集热转换、匹配制冷循环选择、最新研究进展等方面进行了分析介绍.     

SIMULATION OPTIMIZATION RESEARCH ON SOLAR ENERGY-PHASE CHANGE THERMAL STORAGE-FRESH AIR HEATING SYSTEM

构建太阳能-相变蓄热-新风供暖系统用于承担建筑新风负荷,以全玻璃真空管集热器作为系统集热组件,以相变蓄热装置作为系统蓄热组件,以空气-水换热器作为系统供暖末端.通过使系统运行不同模式的方式达到将不稳定的太阳能变为稳定供暖热源的目的.建立耦合系统动态仿真模型并对其进行实验验证.依据此模型对系统最佳设计参数(集热系统流量、相变材料质量、相变温度等)和运行策略进行研究.     

太阳能制冷讲座(1) 太阳能空调制冷技术

太阳能用于空调制冷,最大的优点是季节匹配性好。利用太阳能实现制冷效应有多种技术途径,其中将太阳辐射转变为热能,通过热能实现制冷的方式最具有应用前景,特点是能够实现太阳能供热、空调综合利用,全年综合转换效率高。针对常见的太阳能热能转换制冷空调方式,从太阳能集热转换、匹配制冷循环选择、最新研究进展等方面进行了分析介绍。     

蓄热型太阳能-地源热泵耦合系统设计

以所设计的新型蓄热太阳能-地源热泵耦合系统为研究对象进行了现场模拟实验,太阳能集热器具有季节性蓄热功能,蓄热水箱可在冬季高品质供暖,夏季实现高效制冷。通过实验研究和经济分析结果显示,系统中地埋管换热器和蓄热水箱间歇运行,有利于地下温度场的恢复,延长地埋管的使用寿命,提高地源热泵工作效率及使用年限,具有明显的经济效益。     

新型相变蓄热式太阳能集热管及热性能研究

结合太阳能真空集热管和相变蓄热材料的特点,提出了一种集热/蓄热一体化的新型相变蓄热式太阳能集热管,该集热管主要由金属-玻璃真空集热管、螺旋换热管和相变蓄热材料组成。通过室外蓄放热性能实验进行性能测试,结果表明:该新型相变蓄热式太阳能集热管集热效果良好,集热温度可达80℃以上,可很好地应用于热水供暖领域;以石蜡为相变蓄热材料,单根集热管的蓄热量可达3.25 MJ;放热过程中,有效得热量为873.6 kJ,放热损耗率为0.602;在保温性能上,温降率达1.67℃/h,保温性能待进一步提高。     

三角腔吸热体槽式聚光型太阳能空调系统

本文主要讨论了利用腔体式吸收器和槽式聚光反射集热技术构建太阳能中温集热系统,产生150℃热水或导热油,驱动双效吸收溴化锂空调机运行制冷。通过建设太阳能空调示范系统,在满足夏天制冷、冬天采暖、四季产生热水的需求情况下,研究系统结构、运行及监测方法等,为太阳能空调系统工程应用提供技术支持。     

Solar multi-mode heating system based on latent heat thermal energy storage and its application

为克服太阳能间断性和不稳定性的缺点进而实现太阳能集热与采暖的能量供需调节和全天候连续供热,提出了基于相变储热的太阳能多模式采暖方法（太阳能集热直接采暖、太阳能集热采暖+相变储热、太阳能相变储热采暖）,并在西藏林芝市某建筑搭建了太阳能与相变储热相结合的采暖系统,该系统可根据太阳能集热温度和外界供热需求实现太阳能多模式采暖的自动控制和自动运行。实验研究表明：在西藏地区采用真空管太阳能集热器可以和中低温相变储热器很好地结合,白天储热器在储热过程中平均储热功率为10.63 kW,储热量达到92.67 kW·h,相变平台明显;晚上储热器在放热过程中供热量达85.23 kW·h,放热功率和放热温度平稳,储放热效率达92%,其储热密度是传统水箱的3.6倍,可连续供热时间长达10 h,从而实现了基于相变储热的太阳能全天候连续供热,相关研究结果对我国西藏地区实施太阳能采暖具有一定的指导作用。     

太阳能相变蓄热应用于吸收式制冷的分析

介绍了一种将太阳能相变蓄热技术应用于两级吸收式制冷的新型空调系统,简要分析了该系统的装置结构、工作原理和使用优点。对相变蓄热装置放热过程中放热盘管出水温度随放热时间的变化关系进行了实验测量,并对两级吸收式制冷系统效率进行了分析。通过研究可知,该太阳能空调系统有效解决了以往系统不稳定性和间断性问题;太阳能相变蓄热装置具有体积小、蓄热量大、放热速率大、连续放热温度均匀、便于控制热源加热温度等特点,适合储存太阳能并为吸收式制冷系统提供加热热源。综合考虑系统设备简单,加工要求低的制造特点,所以吸收式制冷以太阳能等低品位热源驱动有着良好的发展前景。     

Optimization of the heat exchanger in a flat plate indirect heating integrated collector storage solar water heating system

Due to the environmental impact of energy usage, consumers need to be encouraged to use renewable energy sources such as solar energy. The indirect heating flat plate integrated collector storage solar water heating system is one of the compact systems for domestic water heating. It incorporates the collection of a solar energy component and a hot water storage component in one unit. The objectives of this study were to investigate the effect of different parameters on the thermal performance of this system with the aim of reducing both the initial and the running costs. The outlet service water temperature was used as a measure of performance, because it is an indicator of the energy acquired from the solar radiation. The continuity, momentum and energy equations of the fluids involved in the system were numerically solved in a steady state condition, using FLUENT software. Three-D CFD models were developed and validated using previous experimental results. A standard k–ω turbulent model was used in the optimization of the heat exchanger because it produced good agreement with the experimental results. The surface-to-surface radiation model was included. The effect of single and double row heat exchangers with different lengths was investigated. Circular and elliptic cross-section pipes were also examined. Mass flow rates of 500 and 650 L/h were chosen. The results showed that the single row HX of 10.8 m length for both the elliptical and type B tube gave high service water outlet temperature (acceptable for heat exchanger design) and with low pumping power. This resulted in an increase in the thermal efficiency and a significant reduction in both the initial and the operating costs of the system.     

Performance analysis of a latent heat storage system with phase change material for new designed solar collectors in greenhouse heating

The continuous increase in the level of greenhouse gas emissions and the rise in fuel prices are the main driving forces behind the efforts for more effectively utilize various sources of renewable energy. In many parts of the world, direct solar radiation is considered to be one of the most prospective sources of energy. In this study, the thermal performance of a phase change thermal storage unit is analyzed and discussed. The storage unit is a component of ten pieced solar air collectors heating system being developed for space heating of a greenhouse and charging of PCM. CaCl₂6H₂O was used as PCM in thermal energy storage with a melting temperature of 29 °C. Hot air delivered by ten pieced solar air collector is passed through the PCM to charge the storage unit. The stored heat is utilized to heat ambient air before being admitted to a greenhouse. This study is based on experimental results of the PCM employed to analyze the transient thermal behavior of the storage unit during the charge and discharge periods. The proposed size of collectors integrated PCM provided about 18–23% of total daily thermal energy requirements of the greenhouse for 3–4 h, in comparison with the conventional heating device.     

Study on key parameters design and economic evaluation of the electric heating and solid sensible heat thermal storage device

电制热固体储热系统对可再生能源消纳、能源清洁化利用具有重要意义。电制热固体储热装置的关键参数设计以及经济性分析是提高经济效益的重要手段。因此,本文提出了电制热固体储热装置投资运行费用计算方法。通过对比不同供暖方式所需费用分析了电制热固体储热装置的经济性。同时研究了谷电利用系数对电制热固体储热装置经济性的影响。最后,采用案例分析验证本文所提经济性评估方法的合理性与正确性。本文的研究内容为用户对电制热固体储热装置的选择提供参考。     

Optimal flow control of a forced circulation solar water heating system with energy storage units and connecting pipes

This paper focuses on pump flow rate optimization for forced circulation solar water heating systems with pipes. The system consists of: an array of flat plate solar collectors, two storage tanks for the circulation fluid and water, a heat exchanger, two pumps, and connecting pipes. The storage tanks operate in the fully mixed regime to avoid thermal stratification. The pipes are considered as separated components in the system so as to account for their thermal effects. The objective is to determine optimal flow rates in the primary and secondary loops in order to maximize energy transfer to the circulation fluid storage tank, while reaching user defined temperatures in the water storage tank to increase thermal comfort. A model is developed using mainly the first and second laws of thermodynamics. The model is used to maximize the difference between the energy extracted from the solar collector and the combined sum of the energy extracted by the heat exchanger and corresponding energies used by the pumps in the primary and secondary loops. The objective function maximizes the overall system energy gain whilst minimizing the sum of the energy extracted by the heat exchanger and corresponding pump energy in the secondary loop to conserve stored energy and meet the user requirement of water tank temperatures. A case study is shown to illustrate the effects of the model. When compared to other flow control techniques, in particular the most suitable energy efficient control strategy, the results of this study show a 7.82% increase in the amount of energy extracted. The results also show system thermal losses ranging between 5.54% and 7.34% for the different control strategies due to connecting pipe losses.     

A design procedure for solar air heating systems

A natural extension of the design procedure for liquid-based solar space and water heating systems is a similar analysis for solar heating systems using air as the heat transfer fluid. In this paper, a solar air heating system incorporating a flat-plate air heater and packed bed thermal storage is described and a simulation model for the system is developed. The results of many simulations of the air heating system are used to establish the relationship between system performance and the system design and meteorological variables. The results are presented in analytic and graphical form, referred to as an f-chart for solar air heating systems. The results of simulations in several widely different climates suggest that the information presented in the f-chart is location independent. Methods of estimating the performance of air heating systems having a collector air capacitance rate and a storage capacity other than those used to generate the f-chart are included. A comparison of the performance of air and liquid based systems is afforded by a comparison of their respective f-charts. The air system is shown to perform better at high load fractions supplied by solar energy than a liquid-based system with the same collector thermal performance parameters.     

Review on solar air heating system with and without thermal energy storage system

In order to produce process heat for drying of agricultural, textile, marine products, heating of buildings and re-generating dehumidify agent, solar energy is one of the promising heat sources for meeting energy demand without putting adverse impact of environment. Hence it plays a key role for sustainable development. Solar energy is intermittent in nature and time dependent energy source. Owing to this nature, PCMs based thermal energy storage system can achieve the more popularity for solar energy based heating systems. The recent researches focused on the phase change materials (PCMs), as latent heat storage is more efficient than sensible heat storage. In this paper an attempt has been made to present holistic view of available solar air heater for different applications and their performance.     

An analysis of solar heating systems that use vapor-compression cycles

This paper analyzes the technical and economic performance of solar heating systems that use vapor-compression cycles, circulating a compressible fluid as the working fluid. With conventional solar heating systems that use water or as their working fluid, the collector inlet temperature is equal to that of the storage outlet temperature. Operating the system on a cold day can result in large thermal losses to the surroundings and, thus, low useful heat gains. A vapor-compression cycle may be attractive because it allows the collector inlet temperature to be lowered so that the heat gain of the collector can be increased. Such a system is simulated and a preliminary economic analysis performed. The results indicate that the vapor-compression system can collect almost 50% more solar energy than a conventional system if the collector area of the two systems are the same.     

German central solar heating plants with seasonal heat storage

Central solar heating plants contribute to the reduction of CO₂-emissions and global warming. The combination of central solar heating plants with seasonal heat storage enables high solar fractions of 50% and more. Several pilot central solar heating plants with seasonal heat storage (CSHPSS) built in Germany since 1996 have proven the appropriate operation of these systems and confirmed the high solar fractions.Four different types of seasonal thermal energy stores have been developed, tested and monitored under realistic operation conditions: Hot-water thermal energy store (e.g. in Friedrichshafen), gravel-water thermal energy store (e.g. in Steinfurt-Borghorst), borehole thermal energy store (in Neckarsulm) and aquifer thermal energy store (in Rostock). In this paper, measured heat balances of several German CSHPSS are presented. The different types of thermal energy stores and the affiliated central solar heating plants and district heating systems are described. Their operational characteristics are compared using measured data gained from an extensive monitoring program. Thus long-term operational experiences such as the influence of net return temperatures are shown.