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。     

室内热源与太阳辐射耦合作用下的太阳能烟囱通风性能研究

针对太阳辐射和室内热源对太阳能烟囱的耦合作用,通过三维数值模拟,研究太阳辐射强度I、室内热源热流密度w、等效内热源面积s和太阳能烟囱进口距地面的高度h对太阳能烟囱通风性能的影响。研究结果表明:当太阳能烟囱结构参数相同时,室内热源和太阳辐射对太阳能烟囱通风量的影响相互促进;随着太阳能烟囱进口距地面高度h的逐渐增加,通风量持续增大,其增大幅度随着室内热源热流密度的增大而增大,随着太阳辐射强度的增大而减小;在相同条件下,太阳能烟囱通风量随着等效内热源面积的增大而增大。     

地表水源热泵辅助热源节能效果的分析

介绍了地表水水源热泵工程中两种常用的辅助热源形式,指出辅助热源的布置形式影响着系统运行的经济性。推导出了两种形式下热泵系统单位小时运行费用,结合某实例说明采用后置式辅助热源的地表水源热泵系统运行费用小,具有节能的优越性。     

用热泵作被动式太阳房辅助热源的研究

北方寒冷地区，农村直接受益式被动式太阳房在采暖季节室内温度较低，舒适性差。本研究采用热泵辅助供暖的方式对被动式太阳房在采暖季节进行供暖实验。通过与煤炉、电加热器、分散式锅炉供暖的比较，验证了该方法的可行性。同时对热泵供暖进行优化，找出影响热泵供暖性能及年成本价格的因素，并对其在小城镇的推广做了分析。结果表明，热泵作为被动式太阳房在北方寒冷地区及电力充沛而集中供暖有困难地区的辅助热源是可行的。     

低温工况热源塔热泵系统应用试验分析

针对热源塔换热能力及热源塔联立热泵主机制热情况分别进行试验研究,并与风冷热泵的制热变化性能进行比较分析。结果表明,控制热源塔进口气液温差恒定的情况下,塔从空气中吸收的热量随环境温度的降低而增加,溶液中溶质的挥发对热源塔吸热量有重要影响;热源塔进口气液温差随环境自然变化的情况下,环境温度与蒸发温度的温差随环境温度的降低而减小,热源塔从空气中吸收的热量也随之减少。在低温工况下,虽然空气含湿量较少,但热源塔热泵系统相比于其他空气作为热源的热泵系统,在潜热换热方面有较大优势。     

固体电热储能系统热变形分析与结构优化研究

为了解决固体蓄热装置中蓄热模块在温度载荷下容易发生热变形,导致蓄热体结构不稳定甚至坍塌问题,采用弹性力学理论对温度载荷下蓄热体的热变形量及热应力进行理论推导,利用数值模拟方法分析了不同占孔比、不同进口空气温度以及固定约束对蓄热体热变形及温度分布的影响,并搭建试验平台对数值模拟结果进行验证。研究表明:进口空气温度越高,蓄热体热变形越大,进口空气温度为950℃时最大变形率达到1.73%;相同工况下,20%占孔比蓄热体热变形量最小、温度分布均匀;固定约束位置出现热应力集中现象,最大热变形出现在蓄热体顶部。     

热源石墨对VHB-6612真空钎焊炉温度场的影响

热源石墨是整个VHB-6612真空钎焊炉的能源提供部件,热源石墨的工作温度在整个VHB-6612真空钎焊炉加热过程起着主导作用,所以研究热源石墨升温速率对加热工件各部分影响非常重要。利用传热学基本原理讨论了热源石墨棒以不同的初始升温速率工作时对加热工件最高温度、最低温度以及两者差值的影响;研究了隔热层内表面钼层黑度对热源石墨棒的最高工作温度和工件整体最大温差的影响。     

建筑围护结构中相变材料的功效分析

对相变材料在建筑围护结构中稳定热源和非稳定热源(正弦波形热源)条件下的热效进行了理论推导,并对武汉地区实际应用的功效进行分析.根据热平衡条件"稳定传热过程通过各层的热流为定值(即q=qr)",对相变材料的相变温度Tc选择进行指导;当相变材料存在时,推导了两种热源条件下的室内温度降低值△T、保温材料节约量△δ以及相变材料对室内温度的滞后时间△t;用正二十二碳石蜡作为相变材料的算例结果表明:在相同条件下与不加相变材料相比,室外温度升高10℃时,加入相变材料可削减室内峰值温度约4℃;当室外温度按正弦波形式变化时,可使室内峰值温度滞后2.65 h.     

太阳能炕和Trombe墙相结合的新型太阳能采暖系统的数值研究

提出了Trombe墙与太阳能炕相结合的新型太阳能采暖系统,建立了新型太阳能采暖系统的理论模型。采用大连1月份的气象数据对该系统的室内温度、炕表面温度等进行数值模拟,讨论运行方式、有无辅助热源等对室内热环境的影响,并与单独采用太阳能炕或Trombe墙的采暖系统进行对比。计算结果显示,在Trombe墙和新型太阳能炕耦合运行模式,室内温度和炕面温度高于炕单独运行模式或Trombe墙单独运行模式;有辅助加热工况下室内热环境的稳定性优于没有辅助热源工况。     

日照作用对热源建筑自然通风影响的研究

参照变电站主变压器室，建立了双侧开口热源建筑数值模型，通过改变大气透过率（sunshine fraction）的大小改变日照强度，利用FL U EN T进行求解，考察日照作用对热源建筑自然通风流动的影响。计算结果表明：日照作用影响热源建筑室内外热量传递的大小和方向，当大气透过率为0．15时，室内外两侧传递热量达到平衡。较大的日照强度导致通风量增大，室内气流速度分布更均匀，日照作用下不同高度的气流温度受到的主要影响因素不同。     

Modeling, design and thermal performance of a BIPV/T system thermally coupled with a ventilated concrete slab in a low energy solar house: Part 1, BIPV/T system and house energy concept

This paper is the first of two papers that describe the modeling, design, and performance assessment based on monitored data of a building-integrated photovoltaic-thermal (BIPV/T) system thermally coupled with a ventilated concrete slab (VCS) in a prefabricated, two-storey detached, low energy solar house. This house, with a design goal of near net-zero annual energy consumption, was constructed in 2007 in Eastman, Québec, Canada - a cold climate area. Several novel solar technologies are integrated into the house and with passive solar design to reach this goal. An air-based open-loop BIPV/T system produces electricity and collects heat simultaneously. Building-integrated thermal mass is utilized both in passive and active forms. Distributed thermal mass in the direct gain area and relatively large south facing triple-glazed windows (about 9% of floor area) are employed to collect and store passive solar gains. An active thermal energy storage system (TES) stores part of the collected thermal energy from the BIPV/T system, thus reducing the energy consumption of the house ground source heat pump heating system. This paper focuses on the BIPV/T system and the integrated energy concept of the house. Monitored data indicate that the BIPV/T system has a typical efficiency of about 20% for thermal energy collection, and the annual space heating energy consumption of the house is about 5% of the national average. A thermal model of the BIPV/T system suitable for preliminary design and control of the airflow is developed and verified with monitored data.     

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。     

Investigation of thermal performance of a passive solar building with floor radiant heating

This paper presents a theoretical study of an integrated radiant floor heating–direct gain passive solar system. Thermal mass is utilized both for storage of auxiliary heating energy and direct solar gains incident on the floor. An explicit finite difference model is developed to accurately model nonlinear effects and auxiliary heating control. The numerical simulation model is employed to study the performance of a passive solar outdoor test-room with different amounts of thermal mass under various control strategies with constant and sinusoidal room thermostat setpoints. A satisfactory thermal mass is determined based on energy savings, reduction of room temperature swings, and prevention of floor surface overheating. Control of auxiliary heating based on a room effective (operative) temperature is shown to result in improved thermal comfort and higher utilization of passive solar gains as compared to room air temperature control.     

Cost of house heating with solar energy

There has long been a need for a practical method of predicting the true cost of heating a house with solar energy and designing the heating system (solar and auxiliary) to achieve the minimum total annual heating cost possible under the particular climatic, geographic, and residential characteristics involved. Rough approximations based on various types of averaged values of weather and seasonal variables have previously been developed, but the reliability of such methods and results is open to question. The authors have therefore made a rigorous analysis of projected solar heating costs in eight U.S. cities and have optimized the heating system design in each location.The analysis involved the use of a high speed computer and approximately 400,000 hourly observations in eight cities of radiation, temperature, wind, solar altitude, cloud cover, and humidity. Equations for performance of flat plate solar collectors and sensible heat storage systems were developed and programmed with the above weather variables and with eight design parameters comprising house size, collector size, storage size, collector tilt, number of transparent surfaces in collector, hot water demand, insulation on storage unit, and thermal capacity of collector. Capital and operating costs were quantitatively related to heating system design parameters, and the values of all design variables which yielded lowest annual heating cost in each city were then selected.The findings are presented in the form of two tables and ten graphs, showing heating costs as functions of various design and location factors. The relative importance of each factor is discussed, and the overall costs of solar heating are compared with the costs of conventional heat supply in each location. The method for designing the least-cost combination of solar and conventional heat supplies is also shown, and an example of the use of the method is presented.     

多时间尺度下计及光热—储热的主动配电网主辅联合优化调度

为解决可再生能源弃风、弃光现象与不平衡功率惩罚较重等问题,提出了一种多时间尺度下考虑光热—储热的主动配电网主辅联合调度策略.该策略在满足内部负荷前提下参与电能与备用日前市场,考虑含光热—储热的主动配电网协调调度风电、光伏、需求响应,在促进风光消纳、减少不平衡功率的同时提高主动配电网运行经济性.首先根据含储热的光热电站与...     

昆明地区直接受益式太阳房室内温度研究

为了直观了解昆明地区太阳房的室内温度分布情况,本文以昆明地区2012年11月实测气象数据为研究依据,利用太阳房热平衡计算辅助流体分析及仿真软件FLUENT计算和模拟出昆明地区直接受益式太阳房室内温度及温度场分布,得出室内温度分布不均可以通过改变南面窗墙比来改善的结论.     

太阳能集热室体热性能参数研究及测量

依据传热基本原理，对保温室体热性能参数进行非稳态（升温、降温）理论分析，实现了温室隔热体传热系数及蓄热当量系数的非稳态测量。利用数学处理，提出了准确实用的试验测量方法并进行了试验验证。     

Modeling of the CSU heating/cooling system

This paper resents a thermal simulation of the Colorado State University solar house. A computer model of the solar energy system was developed and computer runs were made using one year of meteorological data to determine the important design features. The system consists of a flat plate solar collector, main storage tank, service hot water storage tank, auxiliary heater, absorption air conditioner with cooling tower and heat exchangers between the collector and storage, storage and service hot water tank and storage and residence. This system very closely models the CSU house in operating mode one.The results are in the form of monthly integrated values for the pertinent energy quantities. In addition, results are presented which show the effect on the system performance of the collector tilt, collector area and number of covers.     

复合地源热泵系统冬季供暖运行实验研究

介绍了地源热泵在冬季运行供暖的实验研究,具体分析了长期连续运行时土壤温度的变化规律,热泵机组系统的COP变化情况,以及太阳能辅助系统与地源热泵系统联合运行时土壤温度的变化规律,热泵机组系统的COP变化情况.试验数据表明了增加太阳能辅助地源热泵系统后,显著地提高了冷凝器出口温度和室内温度,有效地提高了热负荷,增加了供热面积.总结出了本地区地源热泵系统的一般运行规律.     

高温相变蓄热技术的研究进展

蓄热技术不仅能缓解环境污染和能源浪费的问题,还可以解决热能供给与需求失的矛盾.文中对高温相变蓄热技术的应用和研究现状做了一个综述,从蓄热材料的选择、蓄热器的数值模拟和数学建模、系统研究三个方面对高温相变蓄热技术的研究进展热点以及现状进行了总结.尤其对高温相变蓄热技术在太阳能热发电中的应用现状,并对高温相变蓄热技术在太阳能热发电中的应用进行了分析和展望.