室内环境对自然冷源陈列柜冷藏性能影响实验研究

通过试验研究的方法,将自然冷源引入冷藏陈列柜,在完全利用室外冷源对陈列柜柜内进行供冷的运行模式下,保持风幕送风速度为1.1m/s,室外送风温、湿度分别为1.0℃、60%,室内湿度为60%不变,调节室内不同的温度,观察柜内食品包温度变化分布,研究陈列柜食品包冷藏特性。实验结果表明:与利用制冷系统供冷的传统陈列柜相比,自然冷源供冷使柜内温度分布均匀性得到很大提升,自然冷源陈列柜1~5层同侧食品包温差不超过1.5℃,但是每层内侧和外侧食品包温差在2.5~3.0℃。在此送风条件下,保证室内温度在22.0℃以下可以满足柜内食品贮藏温度0.0~7.0℃的要求。风幕参数变化规律:随着食品包前端距离的增加相对湿度呈现先增大后减小,最后稳定于和室内湿度相等的趋势。风速和温度呈逐渐减小的趋势,且变化速率不断减小。     

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.     

基于热网变负荷过程的热用户室内温度动态特性分析

针对供热机组具有以热定电的特性,导致冬季北方地区弃风现象严重的问题,在分析热网系统中供热机组、热网管路以及热用户特性的基础上,参照供热机组历史运行数据和气象数据,通过计算预测得到不同室外温度下热用户的热负荷。在考虑热用户本身蓄热能力的前提条件下,运用动态数学模型方法求解供热机组供热负荷变化时热网热用户室内温度动态特性。最终可通过热网降负荷过程的过渡时间长短来确定供热机组降负荷参与调峰的时间,为供热机组降负荷参与电网深度调峰的运行方式提供理论基础。     

基于复叠制冷的温度交变系统能效分析

温度交变系统需要周期性地加热和冷却,当冷却温度在-40℃以下时,常用复叠式制冷装置供冷。文中针对制冷剂旁路法和蓄冷法两种设计模式建立了简化的热力学分析模型,分别计算了两种模式下的动态冷量、加热量和耗功。对比结果表明:在典型运行条件下,蓄冷法设计能有效降低能耗,同时减小制冷装置尺寸,其代价是增加蓄冷器和载冷剂回路。     

1000MW超超临界锅炉水冷壁工质温度计算研究

以某台1 000 MW超超临界塔式锅炉作为研究对象,采用分区计算简化高参数超超临界锅炉炉内对流与辐射传热模型,分析不同锅炉负荷条件下膜式水冷壁工质温度的分布规律,将计算结果与实测数据进行比较,最大偏差为1.66%,认为该模型可以预测水冷壁工质温度分布。研究表明:超临界压力下工质由液态直接过渡为汽态,相变区内工质温度变化很小;亚临界压力下存在汽液共存区,其中的工质温度保持不变,当负荷达到662 MW时工质温度为362.5℃,当负荷达到507 MW时工质温度为344.8℃;计算得到工质温度波动在2.8℃以内,螺旋管圈表现出优越的平衡燃烧扰动能力,水冷壁出口最高工质温度为458.0℃。     

智慧供热技术与节能降耗

在民用住宅与公共建筑中,选取供热管网中具有一定代表性的热用户,将具备GPRS通讯方式的室内温度无线远传采集模块放在室内,通过无线远传模块将热用户的室温数据发送到自控柜中的工控机,智慧供热系统再对室温数据进行分析处理,汇总各种因素绘制出最佳的室内温度曲线来调节供热运行曲线,以达到节能的目的。     

超市空调室内设计参数与总能耗分析

针对目前室内设计温、湿度对超市环境舒适性影响的研究较少,以及在超市能耗的研究中,对超市空调和制冷的相互作用的忽视甚至误解的现状,本文将综合分析超市室内温度、相对湿度对超市环境舒适性、超市空调能耗、陈列柜能耗的影响,找出上海超市夏季空调最佳温、湿度设定点。     

浦东机场航站楼暖通空调系统的节能运行

浦东机场的空调采用区域供冷供热(DHC)的形式,用能量较大。结合机场航站楼的空调运行实践,介绍了空调合理用能和节能运行的一些做法和改进措施,包括根据航站楼冷负荷和热负荷需求,采用变水温输送冷量或者热量,末端空调设备的运行与航班的联动,分层分系统开启空调设备和优化气流组织,改善空调效果,以及冬季有特殊要求的区域采用直接引入室外新风或者利用冷空气冷却空调水解决内区冬季供冷。这些节能措施弥补了设计方案的不足,取得了很好的节能效果。     

地板辐射供冷系统热舒适性的分析与研究

通过对采用地板辐射供冷系统建筑中竖直方向温度分布的均匀性、水平方向温度分布的均匀性、室内空气相对湿度、室内平均辐射温度等影响人体舒适度的因素进行理论分析并用实验进行验证,得出各个影响因素的变化规律以及影响舒适度的本质所在。如果整个系统设计合理,地板辐射系统在夏季供冷是完全可以满足人体热舒适度的要求,尤其在气候干燥的北方、西北地区能很好地发挥其舒适、节能的巨大优势。     

基于等效温度的太阳辐射影响下冬季室内人体热舒适研究

该文在青岛某办公楼进行现场实测,研究冬季太阳辐射对坐姿人体皮肤温度和热感觉的影响。结果表明,受到照射时,左大腿皮肤温度上升3.3℃,左上臂皮肤温度上升2℃。根据实测数据,计算人体显热散热量,得到人体各部位与整体的等效温度,给出了太阳辐射影响下的等效温度热舒适区,对于高源强太阳辐射下的室内热环境标准及设计具有重要指导意义。     

超市空调的室内设计参数与总能耗

目前有关超市的室内设计温、湿度对环境舒适性影响的研究匮乏，对超市空调和制冷的相互作用往往忽视或误解。在综合分析了超市室内温度、相对湿度对超市环境舒适性、超市空调能耗、陈列柜能耗的影响后，找出了超市夏季空调最佳温、湿度设定点。     

A numerical simulation tool for predicting the impact of outdoor thermal environment on building energy performance

A building affects its surrounding environment, and conversely its indoor environment is influenced by its surroundings. In order to obtain a more accurate prediction of the indoor thermal environment, it is necessary to consider the interactions between the indoor and outdoor thermal environments. However, there is still a lack of numerical simulation tools available for predicting the interactions between indoor and outdoor microclimate that take into account the influences of outdoor spatial conditions (such as building forms and tree shapes) and various urban surface materials. This present paper presents a simulation tool for predicting the effect of outdoor thermal environment on building thermal performance (heating/cooling loads, indoor temperature) in an urban block consisting of several buildings, trees, and other structures. The simulation tool is a 3D CAD-based design tool, which makes it possible to reproduce the spatial forms of buildings and constructed surface materials in detail. The outdoor thermal environment is evaluated in terms of external surface temperature and mean radiant temperature (MRT). Simulated results of these temperatures can be visualized on a color 3D display. Building heating/cooling loads and indoor air temperature (internal surface temperature) can also be simulated. In this study, a simulation methodology is described, and a sensitivity analysis is conducted for a wooden detached house under different outdoor conditions (building coverage, adjacent building height, surrounding with trees or no-trees). Simulation results show that the simulation tool developed in this study is capable of quantifying the influences of outdoor configurations and surface materials on both indoor and outdoor environments.     

Simulation of Velocity and Temperature Distributions of Displacement Ventilation System with Single or Double Heat Sources

In order to obtain a better understanding of flow characteristics of displacement ventilation,thethree-dimensional numerical models are developed using the CFD technology.The numericalsimulation results are verified by experiments,based on this,the velocity and temperature distributionof three-dimensional displacement ventilation system with single and double heat sources are studied.Velocity and temperature fields under two different cases of heat source are analyzed and compared.The numerical results show that there are three layers in vertical temperature fields of displacementventilation system with single or double heat sources,and the vertical temperature distribution ofsingle heat source is different from that of double heat sources.When indoor load is large,the comfortrequirement of people indoor can't be satisfied with displacement ventilation system only,thus anadditional refrigeration system is necessary.Furthermore,under the condition of two heat sources,thedisplacement ventilation parameters can't be computed simply according to single heat source inletparameters,therefore the interaction between heat sources should be considered.     

大型超市室内环境及空调系统能耗测试分析

深入了解掌握建筑空调系统实际运行状况,有助于准确地分析建筑能耗及空调系统能耗。为此作者选择了上海某一大型超市,通过测试其夏季室内热环境、空调机组、冷水机组水流量等参数,得出超市室内温湿度的分布状况、空调水系统的平衡程度以及冷水机组的能效比,发现实际运行中存在的问题,提出改进超市空调系统运行的方案。     

Finite-difference prediction of transient indoor temperature and related correlation based on the building time constant

A numerical procedure for the calculation of the transient indoor temperature in buildings is developed. The procedure is based on an implicit finite-difference solution of a closed set of differential equations, which express the indoor energy balance and the transient heat conduction in all elements of the building envelope. Using the above procedure, calculations are carried out for 21 types of buildings with 18 and 10 different kinds of wall and roof constructions, respectively, i.e. the total number of building cases examined is 21 × 18 × 10 = 3780 with floor areas ranging from 30 m² to 300 m². It is found that buildings of different construction characteristics and sizes but with the same time constant, respond in a similar way under the same outdoor temperature variation. Based on this similarity, a correlation is developed which expresses, under periodic conditions, the indoor temperature variation in terms of the building time constant and the outdoor temperature characteristics. The correlation contains nine coefficients, the values of which are different for different ranges of the building time constant.     

Annual variations of temperature in a sample of UK dwellings

The internal temperatures of 25 households in Northern Ireland were measured in each house at four locations: the bedrooms, living rooms, halls and kitchens, and analysed on seasonal, monthly and daily bases. In 80% of the homes the winter average daily temperature was between 15 °C and 20 °C and in summer between 20 °C and 23 °C, therefore maintaining a reasonably comfortable temperature throughout the year. In 14% of the homes, the daily average temperature was above 21 °C throughout the year, suggesting a higher household temperature than required for comfort, thus exhibiting wasteful energy behaviour. Three percent of the homes did not use their heating adequately and the winter average temperature was below 15 °C. For the majority of households, the highest indoor temperature was in August and the lowest in February. In general the peak temperatures of households occur in the evening after 8:00 pm. The peak bedroom temperatures occur between 10:00 pm and midnight and in the morning after 8:00 am. The peak living room temperature is generally in the evening while it is occupied. Correlations between the temperature difference between indoor and outdoor temperatures with outdoor temperature have been developed for each house and the four locations. The relationship between the fluctuations of average daily temperature with annual average temperature has been established.     

环境湿度对卧式陈列柜热负荷影响的数值分析

随着大型超市的不断发展，陈列柜的使用量越来越大，陈列柜的节能也越来越重要。采用雷诺应力模型对某型卧式陈列柜的温度场和湿度场进行了仿真计算和实验验证；并通过实验的手段，对环境湿度对卧式陈列柜热负荷的影响进行了研究。     

基于ANSYS模拟巷道围岩调热圈分布研究

应用ANSYS软件对在通风量不同情况下围岩调热圈温度分布及井巷在自然通风状态下与人工通风情况下各自围岩调热圈温度分布情况进行数值模拟。结果表明在自然通风情况下调热圈半径为3.09 m,人工通风作用下调热圈向岩层内部扩散较为显著,且其值为4.3 m。对高温深井进行通风量控制以及热害防治有指导意义。     

环境湿度对卧式陈列柜热负荷影响的数值分析

随着大型超市的不断发展，陈列柜的使用量越来越大，陈列柜的节能也越来越重要。采用雷诺应力模型对某型卧式陈列柜的温度场和湿度场进行了仿真计算和实验验证；并通过实验的手段，对环境湿度对卧式陈列柜热负荷的影响进行了研究。