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对某数据中心空调制冷系统进行详细调研,对设备配置数据进行统计,全面分析空调系统用能情况及存在的问题。提出我国数据中心空调制冷系统设计人员应充分考虑实际情况,结合未来发展选择空调制冷设备,提高数据中心空调制冷系统能效。 相似文献
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一、国外区域供热、供冷技术的发展及原因分析
1.区域供热供冷的优越性
(1)改善城市大气环境质量的效果明显
图1表示热负荷密度和SO2发生强度的关系.从图中可知,在热负荷密度为1.0的地区,采暖设备平均热效率为60%,燃A重油(含硫重量百分比为1%)的SO,发生强度为70kg/h/25公顷,而区域供热后,燃烧效率为80%,则SO2发生强度约为55kg/h/25公顷.由此可见,区域供热的环保效益明显. 相似文献
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选取电能替代供冷、供热技术与燃气分布式能源进行对比分析。首先分别对电能替代供热供冷技术比较,遴选出经济效益较好的电能替代技术进行组合,然后与燃气分布式能源同时供冷供热进行比较,获取电能替代供冷供热较好的技术方案,排序为蓄冷蓄热(热泵)、水源热泵、空气源热泵、地源热泵、蓄冷热泵+电采暖。最后,以燃气分布式能源的投资回收年限为约束,对比分析天然气价格对应的临界电价,获取不同电价政策下的利润空间和利润比例。燃气分布式能源适用于具有一定规模,冷热需求较大、燃气管道已铺设的用户,电能替代供冷供热技术更具有灵活性,可适应各种规模的用户,但对于电力供应稳定性要求较高。 相似文献
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DeST能耗模拟软件在某建筑冷热源方案分析中的应用 总被引:1,自引:0,他引:1
采用DeST软件建模分析了上海市某商业综合楼的负荷状况,并利用负荷分析结果进行了冷热源的装机容量分析降低了该项目设备的设计装机容量.同时,利用DeST软件计算所得的全年逐时负荷对建筑的蓄冷冷源的选型进行了分析,为蓄冷冷源的设计分析方法提供了新思路. 相似文献
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以杨凌某小区地下水源热泵系统为对象,于2010年2月及8月份对系统的各用能设备进行实地监测。结合现行能效标准,提出了水源侧输配系统、用户侧输配系统、热泵主机及热泵系统的能效指标。经测试,水源侧、用户侧输配系统及热泵系统均处于非节能状态,热泵主机处于节能状态。该测试结果对于分析各用能设备能耗、发掘系统节能潜力、提高地下水源热泵系统能效具有指导意义。 相似文献
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基于格子理论建立通用吸附等温方程,从吸附氢分子间作用能随表面遮盖率、温度的变化中比较活性炭在低温区域储氢行为的异同.应用文献中的拟合公式计算氢在活性炭上的吸附数据,通过通用吸附等温方程的线性化确定氢在活性炭上与最大吸附容量对应的最大表面密度.引入维里吸附方程,结合第二维里吸附系数和亨利定律计算吸附层内氢分子受到的壁面吸附势,并由平衡态的能量分析确定氢分子间作用能.结果表明,氢分子在活性炭吸附表面的最大密度小于液氢表面密度且随温度升高而减小,氢分子间作用能在较大比表面积和微孔容积的活性炭中随表面遮盖率和温度的变化更为剧烈,须根据氢分子特性设计活性炭以提高其储氢性能. 相似文献
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以实际生产步进梁式加热炉为例,通过详细的热平衡计算,对比分析了不同煤气热值及供热方式下加热炉的节能效果,为炉子设计选择合理的供热方案提供参考,以节约燃耗和提高炉子热效率。 相似文献
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Siavash Khajehhasani Bassam A. Jubran 《Numerical Heat Transfer, Part A: Applications》2013,63(4):414-435
In the present paper, a numerical investigation is conducted on film cooling performance from novel sister-shaped single-hole schemes. Based on the sister hole film cooling technique, shaped holes are formed by merging discrete sister holes to a primary hole. Simulations are performed at four blowing ratios of 0.25, 0.5, 1, and 1.5. The novel-shaped holes resulted in a significant reduction in the jet liftoff effect in comparison with a cylindrical and a forward-diffused shaped hole. Moreover, film cooling effectiveness is notably increased at the high blowing ratios of 1 and 1.5. 相似文献
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利用Fluent软件中的多孔介质模型,分析了夏季环境风对空冷塔流动传热性能的影响,得到空冷塔流动传热性能最差时的环境风速.针对此环境风速下的空冷塔流场分布特点,在考虑周围厂房影响的基础上装设翅墙,对空冷塔进行安全运行改造,保障机组安全稳定运行.结果表明:当环境风速为12m/s时,空冷塔的流动传热性能最差;考虑厂房的影响后,空冷塔的通风质量流量和换热量沿周向分布的不均匀性进一步增大,其流动传热性能变差;加装翅墙后,空冷塔的穿堂风质量流量减少26.57%,通风质量流量和换热量分别增加24.55%和13.01%. 相似文献
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Alexandru Dobrovicescu Alexandru Serban Ciprian Filipoiu Liviu Drughean 《能源与动力工程:英文版》2014,(2):282-291
The paper deals with the comparative analysis of the performance of cooling and heating systems operating with NH3 (ammonia) or CO2 (carbon dioxide), both natural refrigerants. The study is based on the exergetic analysis that points out the location and the magnitude of a system malfunction. Both systems, with NH3 or CO2 operate in two stages. The exergetic analysis gives the direction of the structural optimization. The exergetic analysis has shown that the best structural schematic is not the same for the two agents. The exergetic analysis points out that the largest exergy destruction in the CO2 cycle is due to the throttling process and offers solutions to diminish it. 相似文献
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In this work a theoretical model and experimental measurements of a point-focus photovoltaic concentrator system with passive cooling are presented. A calculation of the optimal configuration with respect to Cost/Wp of the system, bearing in mind reasonable simplicity and low-cost solutions, has been carried out. Concentration ratio, cell and aperture areas have been analysed in a theoretical cell model and a thermal model. In the latter, heat sink configuration have been considered. Measurements have been obtained, for comparison with the theoretical models, for several lens aperture areas (79 to 1600cm2 ) and several sizes of cells (0.25 to 23 cm2). We have found that the lowest cost system corresponds to a concentration of 112 (X)and a ll cm2 cell area. For cost up to 10% greater than this minimum the concentration can range from 40 to 310 (X) the cell area from 3 to 30 cm2 and the lens area from 500 to 2800 cm2. 相似文献
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《内燃机与动力装置》2017,(5):40-44
以某车型为研究对象,建立三维模型,并使用三维仿真软件Star-ccm+对模型进行仿真计算,通过相应车型在整车环境实验室中的试验数据进行验证,随后对该车型降温过程中流场及温度场分布进行分析。分析表明,送风射流区域、车顶后部下方区域以及乘员头部附近区域速度较高,乘员舱前部区域比后部区域温度高,下部区域比上部区域温度高。 相似文献
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This paper presents experimental and numerical analyses of the aero-thermodynamic characteristics of a natural-draft cooling tower. The influence of local technical faults in the fill and rain region on the cooling tower's performance was estimated. Measurements of the air velocity and the temperature above the droplet eliminators showed a noticeable non-uniformity of both parameters. This is caused by a non-uniform airflow resistance and heat-transfer rate within the fill and rain region. Based on these measurements, a commercial CFD model was customized with additional relations describing the heat- and mass-transfer, as well as the airflow resistance in individual regions of the cooling tower. The results of a 3D numerical simulation of the cooling tower are the temperature and velocity distributions within the entire cooling tower. A comparison of nominal and actual cooling tower operation shows regions with unfavorable air temperatures or velocities. Thus, the inefficiently operating areas of the cooling tower's cross-section can be identified. These areas cause non-homogeneous aero-thermodynamic characteristics and have an influence on the integral characteristics of the cooling tower. A sample calculation of an actual cooling tower shows the usefulness of the method when it comes to improving the cooling tower's performance. The improvement can be achieved by modifying the fill resistance and water distribution. 相似文献