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本文研究了大型超市建筑夏季空调冷负荷的主要影响因素,并以上海市某一大型超市建筑为例,分析其夏季空调负荷的分布规律,并针对不同的冷热源选择方案,结合超市建筑的空调负荷特点,提出了多种空调冷热源方案的适用性,可为大型超市空调冷热源的设计提供参考. 相似文献
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从民用机场建筑地理位置,建筑结构的生,探讨机坪辐射现象对候机楼为主的民用机场建筑空调冷负荷的影响,宽阔,平坦的,大面积的停机坪在夏季强烈阳光照射下形成一个巨大的发射平面,与阳光共同形成机坪辐射,而这种辐射所形成的最大负荷与建筑物的温差传热最大值出现在同一时段,形成空调系统的高峰负荷,因此,机坪辐射对机场建筑空调冷负荷的影响应是一个不容忽视的因素,对于候机楼等机坪周边机场建筑的空调冷负荷,材料选择以及空调送风系统的布置等,除了考虑一般影民用建筑空高冷负荷的因素外,应充分考虑机坪辐射的影响。 相似文献
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针对建筑空调系统能耗的影响因素和商业建筑的特点,以商业建筑空调节能改造为例,从减少冷热负荷、提高冷热源效率、利用自然冷源、减少水泵电耗、减少风机电耗、改进气流组织等6个方面分析了商业建筑空调节能的具体技术措施和实施办法. 相似文献
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针对建筑空调系统能耗的影响因素和商业建筑的特点,以商业建筑空调节能改造为例,从减少冷热负荷、提高冷热源效率、利用自然冷源、减少水泵电耗、减少风机电耗、改进气流组织等6个方面分析了商业建筑空调节能的具体技术措施和实施办法。 相似文献
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建立地埋管传热模型和系统能耗模型,对非平衡冷热负荷条件下地源热泵系统运行特性进行模拟计算。当建筑空调冷负荷大于热负荷,且供冷时间较长时,地源热泵系统从冬季初始运行,到达夏季时段,地温比夏季初始运行低,更加有利于夏季地源热泵系统节能。地源热泵系统运行7a后,采取夏季和冬季初始运行两种方案的地埋管钻孔壁年平均温度与土壤初始温度相比,分别上升3.10和5.12℃,导致机组耗功率逐年增加,应考虑采用复合式地源热泵系统间歇运行或增设地埋管设置分区运行策略,平衡土壤传热量。 相似文献
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通过TRNSYS软件模拟不同传热系数的建筑外窗,在严寒地区和夏热冬暖地区,对建筑冷、热负荷的影响。分析得出,节能外窗在严寒地区夏季空调能耗的节能率为8.9%,冬季采暖能耗的节能率为39%,全年总建筑能耗的节能率为31%;在夏热冬暖地区夏季空调能耗的节能率为8.0%,冬季采暖能耗的节能率为22%,全年总建筑能耗的节能率为8.6%。由此可见,外窗在严寒地区的节能效果要明显优于夏热冬暖地区。因此,在新建建筑的节能设计和既有建筑的节能改造中,严寒地区应更加重视外窗部分。 相似文献
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如何合理使用磨合期的汽车,使其摩擦机件的磨损量能够平稳、均匀地磨合而不至于过度磨损,对汽车实际使用寿命有着重要的意义。从机器磨合期的特点和磨损机理出发,对汽车磨合期如何正确使用进行了有实际意义的探讨。 相似文献
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Kiril Popovski 《Geothermics》1988,17(2-3)
SFR Yugoslavia has natural hot water springs practically all over its territory, indicating the presence of geothermal reservoirs underground. There is no final estimate of how much energy can be expected from this new resource, except for figures based on the results of studies and investigations.The first use of geothermal energy in Yugoslavia in numerous spas dates back to the 19th century. Some remarkable examples of central heating are known, but the most widespread use is in agriculture (in greenhouse heating, farm heating and drying of agricultural products). 相似文献
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In this study, various energy conservation measures (ECMs) on heating, ventilating and air conditioning (HVAC) and lighting systems for a four-storied institutional building in sub-tropical (hot and humid climate) Queensland, Australia are evaluated using the simulation software called DesignBuilder (DB). Base case scenario of energy consumption profiles of existing systems are analysed and simulated first then, the simulated results are verified by on-site measured data. Three categories of ECMs, namely major investment ECMs (variable air volume (VAV) systems against constant air volume (CAV); and low coefficient of performance (COP) chillers against high COP chillers); minor investment ECMs (photo electric dimming control system against general lighting, and double glazed low emittance windows against single-glazed windows) and zero investment ECMs (reset heating and cooling set point temperatures) are evaluated. It is found that the building considered in this study can save up to 41.87% energy without compromising occupancies thermal comfort by implementing the above mentioned ECMs into the existing system. 相似文献
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《Energy Policy》2015
Heating is arguably one of the most difficult sectors to decarbonise in the UK's energy system. Meeting the 80% greenhouse gas emission reduction target by 2050 is likely to require that heat related emissions of CO2 from buildings are near zero by 2050, and there is a 70% reduction in emissions from industry (from 1990 levels). Though it is clear that the use of the natural gas network will reduce over time, recent modelling suggests a limited residual role for gas by 2050 to help meet peaks in heat demand. High levels of uncertainty about the way in which heat will be decarbonised present a number of challenges to policy makers. This paper will explore the risks and uncertainties associated with the transition to a low carbon heat system in the UK as outlined by the 4th carbon budget review. The potential impact of key uncertainties on the levelised costs of heat technologies and the development of energy networks are explored using a sensitivity analysis approach. Policy changes required to decarbonise the heat sector are also examined. 相似文献
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Solar drying in sludge management in Turkey 总被引:2,自引:0,他引:2
Two main wastewater treatment plants in Bursa city in Turkey will start to operate and produce at least 27,000 tons of dry solids per year by the end of 2006. The purpose of this study was to investigate an economical solution to the sludge management problem that Bursa city would encounter. The general trend in Turkey is mechanical dewatering to obtain a dry solid (DS) content of 20%, and liming the mechanically dewatered sludge to reach the legal landfilling requirement, 35% DS content. This study recommends limited liming & solar drying as an alternative to only-liming the mechanically dewatered sludge. Open and covered solar sludge drying plants were constructed in pilot scale for experimental purposes. Dry solids and climatic conditions were constantly measured. Faecal coliform reduction was also monitored. The specially designed covered solar drying plant proved to be more efficient than the open plant in terms of drying and faecal coliform reduction. It was found that, if the limited liming & solar drying method was applied after mechanical dewatering instead of only-liming method, the total amount of the sludge to be disposed would be reduced by approximately 40%. This would lead to a reduction in the transportation, handling, and landfilling costs. The covered drying system would amortize itself in 4 years. 相似文献
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Viscous heating in liquid flows in micro-channels 总被引:1,自引:0,他引:1
Gian Luca Morini 《International Journal of Heat and Mass Transfer》2005,48(17):3637-3647
Many experimental works on forced convection through micro-channels evidenced that when the hydraulic diameter is less than 1 mm, conventional theory can no longer be considered as suitable to predict the pressure drop and convective heat transfer coefficients. This conclusion seemed valid for both gas and liquid flows. Sometimes the authors justified this claim by invoking “new” micro-effects. On the contrary, in this paper the explanation of the experimental results obtained for micro-channels in terms of friction factors will be researched inside the conventional theory (Navier-Stokes equations). In particular, this paper will focus on the role of viscous heating in fluids flowing through micro-channels. A criterion will be presented to draw the limit of significance for viscous dissipation effects in micro-channel flows. The role of the cross-sectional geometry on viscous dissipation will be highlighted and the minimum Reynolds number for which viscous dissipation effects can no longer be neglected will be calculated as a function of the hydraulic diameter and of the micro-channel geometry for different fluids. It will be demonstrated how viscous effects can explain some experimental results on the Poiseuille numbers in micro-channels, which recently appeared in the open literature. 相似文献
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Energy consumption in rural transportation has been computed, taking into account the energy embodied in vehicles or bullocks, as well as the fuels or feeds and food (of operators). Bullock cart transport consumes over four times more energy than vehicles. However, animal transport will continue to be preferred because of its availability. 相似文献
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《Energy Policy》2014
A third of electricity in India is lost each year, where losses refer to power that is supplied but not billed. Utilizing data from the power corporation of Uttar Pradesh, India's most populous state, we study the politics of electricity losses. Examining annual data over four decades, we document that UP's electricity losses tend to increase in periods immediately prior to state assembly elections. Drawing upon geographically disaggregated data for the period 2000–09, we observe higher line losses just prior to the 2002 and 2007 state elections. Our analysis shows that the incumbent party was more likely to retain the assembly seat as line losses in the locality increased. We interpret these results as corroboration that political parties deliberately redirect electricity to flat rate and unbilled users in a context of chronically inadequate supply. Political factors appear to affect line losses in ways that technical and economic factors alone cannot explain. 相似文献