增设喷雾降温系统的家用空调器性能与特性的试验研究

针对家用空调器夏季运行室外热环境差的问题,提出在其室外机增设喷雾加湿装置以降低冷凝温度进而达到提高空调器性能和制冷量的目的。本文对增设喷雾降温系统地空调器进行了试验研究,分析了增设喷雾降温系统对空调器冷凝器出口空气温度和制冷系统性能的影响。实测研究发现,增设喷雾加湿系统后,冷凝器出口制冷剂压力有所降低,制冷系统性能系数EER可提高2%~7%,效果显著。     

空调系统制冷剂充灌量与毛细管长度的优化匹配研究

在制冷剂充灌量和毛细管长度对空调系统性能影响进行数值仿真分析的基础上 ,建立了空调器制冷剂充灌量与毛细管长度的优化匹配模型 ,确定了以制冷量和EER为优化目标的制冷剂充灌量和毛细管长度的优化区间和制冷量最大以及EER最大时的制冷剂充灌量和毛细管长度 ,为空调器的优化设计匹配 ,提高空调器的性能奠定了基础     

空调系统制冷剂灌量与毛细管长度的优化匹配研究

在制冷剂充灌量和毛细管长度对空调系统性能影响进行数值仿真分析的基础上，建立了空调器制冷剂充灌量与毛细管长度的优化匹配模型，确定了以制冷量和EER为优化目标的制冷剂充灌量和毛细管长度的优化区间和制冷量最大以及EER最大时的制冷剂充灌量和毛细管长度，为空调器的优化设计匹配，提高空调器的性能奠定了基础。     

采用水焓值法的制冷量源及其不确定度分析

制冷量量值统一对促进空调器行业节能减排有基础性作用,采用水焓值法的制冷量源能够应用于制冷量的量值传递,提供数值可测、可控的制冷量量值。首先,提出了水焓值法制冷量源的装置原理,减少了输出制冷量测量参数;然后,设计并研制了制冷量源实验装置,并在平衡环境型量热计中进行了实验研究,实验结果显示,量热计测得值与冷量源输出制冷量最大相对偏差不超过±0.7%;最后,详细给出制冷量源的不确定度评定过程和结果:制冷量源重复性为11.4 W,源输出由1 660.8增大至5 810.4 W时,合成标准不确定度由12.3增大至18.2 W,对应相对扩展不确定度由1.5%(k=2)减小至0.6%(k=2)。采用水焓值法的制冷量源第1次从计量学角度实现了制冷量量值的溯源,输出量值可溯源至温度、压力、流量和功率单位,可作为校准制冷量测量装置的标准源使用。     

采用微通道蒸发器的分离式热管空调传热性能的试验研究

设计了一套采用微通道换热器作为蒸发器的分离式热管空调,并试验研究了充液率、室内外温差和风机风量等因素对其传热性能的影响。试验结果表明:充液率过大过小均会影响系统的传热性能,其最佳充液率为120%左右;室内外温差越大分离式热管空调传热效果越好,空调传热量在室内外温差为20℃时比室内外温差为8℃时增加了228%;当风机风量低于2000m3/h时,传热量和EER随着风量的增加而增大,当风机风量超过2000m3/h时,增加风量对传热量的影响减小,而EER开始呈现下降趋势。     

HLD-40b高温空调混合制冷剂替代研究

针对冶金等高温、高湿环境空气调节的需要,采用R22/R142b组成的非共沸混合制冷剂,对HLD-40b高温空调的R12进行工质替代,通过配比调试和实验研究得到如下结果:(1)标准工况的制冷量和能效比基本相当,T3工况空调制冷量和EER同比均增高10%,T3工况和60°C高温工况的制冷量相对标准空调工况衰减不足10%,对应的排气压力和排气温度均有一定幅度下降,空调的高温运行特性改善明显;(2)60°C高温运行工况的制冷量为4024W,排气压力和温度分别为2.2MPa和109°C,制冷系统高温运行的可靠性得到显著提高。研究表明:高、中温混合制冷剂的合理使用有利于改善空调制冷系统的高温运行性能和可靠性,拓宽其运行温度范围。     

干盘管系统冷冻水流量调节试验研究

通过对独立新风加干式风机盘管空调系统在不同室外工况下的试验研究,分析了冷冻水流量调节对空调系统性能及室内温湿度影响。结果表明,随冷冻水流量增加,系统提供的显热制冷量及潜热制冷量增加,而提供的冷量显热比减少;当冷冻水不能满足新风机组制冷要求时,增加水流量可以明显降低室内冷量显热比,在冷冻水流量满足新风机组制冷要求的基础上增加水流量,对新风机组的制冷量及室内显热比的影响不大;增加冷冻水流量对室内温度影响较大,而对室内相对湿度影响较小。     

生物型添加剂对改善空调器性能的应用研究

在空调器中加入一定量的添加剂后,在焓差实验室中对其进行性能测试.测试了它的制冷量、功率以及排气温度等性能参数,并与相同工况下未加入添加剂时的测试结果进行了对比分析.实验表明,加入不同剂量的生物型润滑油添加剂后,换热器传热效果有所改善,空调系统的排气温度、功耗降低,而制冷量升高,COP平均增大11.62%,达到了提高空调器性能和节能的目的.     

自补充制冷剂双高效家用空调器的研究

为有效解决空调器在使用寿命期内因制冷剂的正常泄漏导致空调器制冷量、制热量下降及能效比降低的问题,在空调器冷凝器出口侧加装自补充制冷剂装置,使空调器制冷系统始终保持在较理想的状态下运行.同时,该装置的制冷剂调节作用还可以改善空调器在正常运行时由于环境温度变化而引起所需制冷剂的变化.按照GB/T7725-2004<房间空气调节器>标准对KFR-25GW空调器加装自补充制冷剂装置前后进行了模拟对比测试,结果表明若空调器每年泄漏量为20g,在其整个10年使用寿命期内,加装后的样机平均制冷量提高18%,制热量提高11%,制冷能效比提高14%,制热能效比提高5%,性能效果及节能效果提高明显.     

变容量空调器的季节能效比的计算和分析

利用某变容量家用中央空调器性能参数,拟合出该空调器制冷量、输入功率、EER与负荷率的变化关系.利用我国近30年来的逐时气象资料,建立了广州、武汉、上海、杭州、重庆地区的温区统计数据,计算出了5个城市的季节能效比（SEER）.同时对武汉地区某空调器4个运行模式的季节能效比进行了计算,指出要反映空调器的实际运行条件下的季节能效比,还必须考虑空调器的实际运行时段.     

Minimal Realization of Linear Graph Models for Multi-physics Systems

An engineering system may consist of several different types of components,belonging to such physical"domains"as mechanical,electrical,fluid,and thermal.It is t...     

Quantum Cooperative Robotics and Autonomy

The intersection of Quantum Technologies and Robotics Autonomy is explored in the present paper.The two areas are brought together in establishing an interdisci...     

On the Relation of Load to Average Gap in the Contact Between Surfaces with Longitudinal Roughness

A computer simulation model for the contact between longitudinally-oriented rough surfaces has been formulated. This model closely duplicates the actual surf ace contact deformation behavior by taking into account the elastic interactions between the asperities. There were no assumptions made about the shapes, or any deformation behavior of the asperities, except for their obeying the laws of elasticity. The plastic deformations on the high asperity peaks were taken into account by setting a ceiling on their contact pressures at the material hardness value. The simulations used real surface profiles which were digitized from unworn circumferentially ground steel surfaces. Each pair of these profiles was mathematically combined to form an equivalent rough profile pressing against an infinitely rigid flat and having the appropriately adjusted elastic modulus. A total of 28 different pairs of profiles were used in the simulations. Each contacting pair was subjected to 30 different load levels and the local contact pressures and deformations were calculated. The contact simulations yielded some important mathematical relationships between parameters, such as the real area of contact, average gap, and average asperity load through statistical curve fitting. Two analytical functions were generated to relate the average load to average gap and the real area of contact to load.     

三绕组变压器的双绕组等效建模及在Matpower中的应用

针对实际电网存在着大量的三绕组变压器,但国际上一些著名商业软件,如BPA仿真软件、Matpower这一权威潮流计算开源软件,均只提供双绕组变压器模型,限制了其在具有三绕组变压器的电力系统中的应用的问题,潮流计算是自主开发的电力系统各种应用软件的核心模块,因此依托国际权威开源程序进行二次开发,是一种较好的选择。对Matpower要求的数据格式进行了归纳,对变压器的一般的等值电路及带理想变压器的等值电路和带标幺值的等值电路进行了分析研究,提出了三绕组变压器转换为双绕组等效模型的建模方法,使得原先只适应双绕组变压器的潮流计算软件可以适用于三绕组变压器电网的潮流计算;最后以Matpower软件为例进行了案例计算,并用PSASP仿真软件进行对比验证。研究结果证明,所提出的建模方法是有效的。     

电站锅炉模糊风险评价方法研究与应用

针对电站锅炉风险等级评价问题,将模糊综合评价技术应用到电站锅炉风险等级评价中。开展了电站锅炉失效影响因素及模糊评价因素的重要程度分析,建立了一套科学合理适于在线评价的电站锅炉风险评价体系,提出了模糊综合评价技术与改进的模糊层次分析法相结合的模糊风险评价方法,利用改进的模糊层次分析法计算了指标体系中各层指标权重。对某一台电站锅炉的实际运行工况影响子因素进行了模糊风险评价,采用模糊合成算子进行模糊综合运算得到电了站锅炉运行工况影响子因素的评价向量。研究结果表明:电站锅炉的运行工况影响子因素的风险评价等级为第6级,失效可能性等级为小,该电站锅炉运行工况良好。     

考虑进油孔有限长滑动轴承油膜力的近似解析解

针对具有进油孔的有限长滑动轴承油膜力求解问题,采用变分原理和分离变量法,求得了有限长滑动轴承油膜压力分布的近似解析表达式。将油膜压力分布的近似解析表达式在油膜存在区域上进行积分,即得到了油膜力。将提出的计算有限长滑动轴承油膜力方法与无限长轴承模型、有限元方法的计算结果进行了比较,发现了提出的方法与有限元方法的计算结果很接近。最后,研究了进油孔位置和进油压力对油膜存在区域、油膜力等的影响,研究结果表明进油孔位置和进油压力对油膜存在区域和油膜力有较大的影响。     

INTEGRAL EQUATION METHOD＇S APPLICATION IN HOLE-EDGE STRESS OF COMPOSITE MATERIAL PLATE WITH DIFFERENT SHAPED HOLES

The strength of composite plate with different hole-shapes is always one of the most important but complicated issues in the application of the composite material. The holes will lead to mutations and discontinuity to the structure. So the hole-edge stress concentration is always a serious phenomenon. And the phenomenon makes the structure strength decrease very quickly to form dangerous weak points. Most partial damage begins from these weak points. According to the complex variable functions theory, the accurate boundary condition of composite plate with different hole-shapes is founded by conformal mapping method to settle the boundary condition problem of complex hole-shapes. Composite plate with commonly hole-shapes in engineering is studied by several complex variable stress fimction. The boundary integral equations are founded based on exact boundary conditions. Then the exact hole-edge stress analytic solution of composite plate with rectangle holes and wing manholes is resolved. Both of offset axis loadings and its influences on the stress concentration coefficient of the hole-edge are discussed. And comparisons of different loads along various offset axis on the hole-edge stress distribution of orthotropic plate with rectangle hole or wing manhole are made. It can be concluded that hole-edge with continuous variable curvatures might help to decrease the stress concentration coefficient; and smaller angle of outer load and fiber can decrease the stress peak value.     

交通荷载作用下桥梁结构参数识别方法

应用动力节点加载法,将作用在桥梁上的交通荷载转化为等效节点荷载,再用两步构造法识别结构物理参数.第1步,用Newmark-β方法变换结构运动方程,并用结构的加速度响应求得变换空间内的位移、速度和加速度响应;第2步,基于最小二乘原理,构造出变换空间内求解结构参数的递推式,进行结构物理参数识别.数值模拟结果表明,在交通荷载作用下,该方法能够快速、准确地进行桥梁结构参数识别.     

Fifth International Summer School on Screw-Theory Based Methods in Robotics

正3-11 September,2014University of Bologna,Bologna,Italy www.summerscrews.org summerscrews2014.ing.unibo.it SUMMER 20SCREWS 14In 2014,our screw-theory school comes to the world's oldest university.In early September,Summer Screws'14 will gather six experts in the application of screw theory in robotics and up to 40 participants at the University of Bologna,Bologna,Italy.The school will teach attendees how to apply existing methods and empower them to develop new ones in their own research.The basic theoretical notions will be introduced in a rigorous manner,emphasizing examples,applications,and exercises.Scholarships are available.     

Non-monotonic material contrast in scanning ion and scanning electron images

30 keV Ga⁺ focused ion beam induced secondary electron (iSE) imaging was used to determine the relative contrast between several materials. The iSE signal compared from C, Si, Al, Ti, Cr, Ni, Cu, Mo, Ag, and W metal layers does not decrease with an increase in target atomic number Z₂, and shows a non-monotonic relationship between contrast and Z₂. The non-monotonic relationship is attributed to periodic fluctuations of the stopping power and sputter yield inherent to the ion–solid interactions. In addition, material contrast from electron-induced secondary electron (eSE) and backscattered electron (BSE) images using scanning electron microscopy (SEM) also shows non-monotonic contrast as a function of Z₂, following the periodic behavior of the stopping power for electron–solid interactions. A comparison of the iSE and eSE results shows similar relative contrast between the metal layers, and not complementary contrast as conventionally understood. These similarities in the contrast behavior can be attributed to similarities in the periodic and non-monotonic function defined by incident particle–solid interaction theory.