共查询到20条相似文献,搜索用时 46 毫秒
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采用关联准则方法对中央空调水系统的运行参数进行了挖掘,得到了在不同室外空气温湿度与建筑冷量需求条件下,能够保证空调系统高效运行的系统运行参数.进一步在该空调系统模拟平台对关联准则的应用效果进行了模拟分析.模拟结果表明,在中等负荷日,采用关联准则中的运行参数(即优化模式)运行与既有模式运行对比,系统的运行效果与能效明显提... 相似文献
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通过对大楼中央空调系统的主要设备、典型末端系统能耗、房间舒适度和系统能耗测试,分析现有系统的运行状态、能耗水平和节能效果,测试表明大楼空调系统具有较好的节能性和较高的空调舒适度.同时,实施制冷机房运行优化、变风量自控策略优化和物业节能运行建议,实现大楼更舒适和节能运行,为大型通讯及办公建筑的空调运行提供示范. 相似文献
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为了能够全面了解深圳市公共建筑中空调系统的实际运行管理水平,通过对深圳市公共建筑空调系统进行现场调研,整理分析并从中抽取采用常规水冷式中央空调系统的公共建筑为样本建筑.通过对深圳市公共建筑空调系统中存在的运行控制现状进行分析,包括冷源系统、水系统和末端系统三个部分,提出了进一步的优化运行控制建议,为今后开展公共建筑节能运行控制提供一定的参考. 相似文献
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优化地源热泵的运行管理策略,降低土壤热不平衡对地源热泵机组性能的影响,是保证地源热泵机组长期稳定高效运行的重要措施.以天津市某办公楼的地源热泵系统为研究对象,对其多年运行之后的土壤温度变化和系统能效变化进行了模拟分析,分析比较了不同间歇运行方案下得到的土壤温度和热泵机组能效的变化.结果表明,地源热泵机组连续运行30年时,土壤温度受热不平衡的影响,呈逐年波动式上升,前15年上升幅度较大,后15年增幅较缓.地源热泵系统间歇运行将有利于地温的恢复,机组的启停比对地源热泵系统土壤温升的累计影响显著大于运行起止时间对土壤温升的影响.研究结果可为地源热泵系统的运营管理提供重要参考与借鉴. 相似文献
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A method is proposed for estimating the parameters of a mixture of exponential and Weibull distributions for which the accuracy of preliminary estimates obtained by graphical analysis is refined in accordance with the criterion of maximum likelihood. The efficiency of the proposed method is supported by the results of statistical modeling. 相似文献
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An approximate analytical expression is derived for the velocity of the front of the wave of change of boiling modes on a
rod and on a plate. The impact of the Thomson effect and of the heater orientation in the gravity field is included. Adequate
agreement is demonstrated between the derived relations and experimental data. 相似文献
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Liebert A Wabnitz H Grosenick D Möller M Macdonald R Rinneberg H 《Applied optics》2003,42(28):5785-5792
A novel method for the determination of the optical properties of tissue from time-domain measurements is presented. The data analysis is based on the evaluation of the first moment and the second centralized moment, i.e., the mean time of flight and the variance of the measured distribution of times of flight (DTOF) of photons injected by short (picosecond) laser pulses. Analytical expressions are derived for calculation of absorption and of reduced scattering coefficients from these moments by application of diffusion theory for infinite and semi-infinite homogeneous media. The proposed method was tested on experimental data obtained with phantoms, and results for absorption and reduced scattering coefficients obtained by the proposed method are compared with those obtained by fitting of the same data with analytical solutions of the diffusion equation. Furthermore, the accuracy of the moment analysis was investigated for a range of integration limits of the DTOF. The moment analysis may serve as a comparatively fast method for evaluating optical properties with sufficient accuracy and can be used, e.g., for on-line monitoring of optical properties of biological tissue. 相似文献
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水三相点是开尔文热力学温度的唯一基准点,也是ITS-90国际温标重要的定义固定点。因此,水三相点不确定度分析对整个温标的建立、温度量值传递起着至关重要的作用。近3年来,中国计量科学研究院研制出一系列高质量的水三相点容器,加强了水三相点的研究,为不确定度的分析提供了更为可靠的实验依据。同时,不确定度的分析也是客观评价新研制容器性能的一个重要指标。因此,根据实验结果对新研制容器所复现的水三相点进行了不确定度评定。评定结果表明,其扩展不确定度为0.16mK(k=2.69,P=0.99)。 相似文献
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Conventional methods for summation of direct measurement errors are considered. Conditions under which these methods provide consistent results are stated. It is proposed to utilize for characteristic of the total error, its interval estimator or the half-sum of the value obtained by adding up its arithmetic and geometric random errors.Translated from Izmeritel'naya Tekhnika, No. 4, pp. 10–12, April, 1995. 相似文献