空气源热泵低温适应性研究的现状及进展

随着改革开放的发展、人们生活水平的提高，许多传统供暖地区的居民开始有夏季制冷的要求，而且这些地区传统的以燃煤为基础的供暖模式所带来的负面影响越来越不能适应社会可持续发展的要求。空气源热泵因其特殊的优点而在长江中下游以南地区备受重视，但是传统的空气源热泵要想成功应用下地北方寒冷地区还有许多问题有待进一步解决。文章分析了空气源热泵系统在寒冷地区使用时需要解决的一些问题，以及国内外为解决这些问题所做的一些工作，对于更好地促进这空气源热泵技术的发展具有积极的意义。     

变频控制技术在中央空调系统中的应用

介绍了在中央空调系统中使用变频技术的控制模式 ,并对实际应用中的控制及节能效果作了分析比较。图 2表 1参 1。     

1000t/h锅炉一次风系统和燃烧器的试验研究

分析了姚孟电厂１０００ｔ／ｈ锅炉排烟温度、飞灰含碳量偏高的原因,提出了相应的改造方案并用数值计算的方法模拟了改造前后的炉内流场,认为变化不大。改造后排烟温度降低了１５．１℃,飞灰含碳量从原来的８．６％降低到３．４％左右,机械不完全燃烧损失降低３％以上。图５表４     

国内第1座蓄热式步进梁和步进底组合式加热炉的开发和应用

介绍了采用高温燃烧技术(HTAC)所设计的国内第1座蓄热式步进梁和步进底组合加热炉的开发和应用，分析了该燃烧系统在组合式步进炉上的应用效果和关键技术，指出了采用HTAC技术进一步优化蓄热式燃烧系统的设计基本思路。     

高温空气燃烧技术的合理利用

通过对比分析目前国内最常用的几种高温空气燃烧技术，从理论和实践两方面客观地评价其各自的优缺点，所得结论对大型企业合理利用该项技术有重要的参考价值。     

Heat transfer augmentation for air jet impinged on a rough surface

An experimental investigation of heat transfer from a round air jet impinging normally from below onto a heated square plate was performed. The objective of the investigation was to study the effect of roughness on both the heat transfer and the fluid flow characteristics. Smooth and rough plates were, therefore, used in the course of the experiments. The heat transfer data were collected for four jet Reynolds numbers, ranging from 6500 to 19 000. The Reynolds numbers are based on the jet-exit velocity (U_e) and the nozzle-exit diameter (D), Re_e=U_eD/ν. The nozzle-to-plate distance ranged from 0.05 to 15 nozzle-exit diameter to cover both the potential core and the far regions of the jet flow. The roughness was composed of cubes of 1 mm dimension distributed uniformly along the plate. The local and average Nusselt number values for the rough plate showed an increase ranging from 8.9% to 28% over those for the smooth plate. Roughness was found to have a strong effect on the flow characteristics; it affected the mean velocity as well as the turbulence intensity of the flow. The mean velocity profiles for the smooth case at radial distances of r/D=1 and r/D=2.5 showed steeper near-wall velocity gradients compared with the profiles of the rough case, where r is the radial distance measured from the plate center along the plate centerline. In addition, roughness caused an increase in the turbulence intensity of the flow.     

Theoretical analysis for an air heater with a box-type absorber

The efficiency of the solar air collector can be enhanced by using metal vanes which are attached between the absorber and bottom plate of the collector. A mathematical model and solution procedure to study the effect of the metal vanes are presented. A method to select an optimal number of metal vanes, as well as an appropriate depth for the flowing air duct, has been developed. Moreover, a comparison between the performance of a collector having a box frame absorber and one having a finned plate absorber was carried out. The results show that a high efficiency can be achieved with the use of the metal vanes, particularly at smaller depths of the air duct.     

NPT5型空气压缩机机油乳化的原因及对策

针对NPT5型空气压缩机机油乳化的惯性故障,分析了造成机油乳化的主要原因,提出了拆检空气压缩机出风管路逆止阀、检查气阀和活塞、安装自动排水阀和更换机油等预防措施,并提出了重新界定机油含水量标准、加强油质监控和使用添加剂的建议。     

基于CORA数据的南海温差能资源时空特征研究

基于2000—2013年中国近海及邻近海域海洋逐日再分析产品(China Ocean Reanalysis,CORA)数据资料,通过计算南海表层(5 m)与深层(1000 m)的温差、卡诺效率、有效水头、暖水体积量、温差能可开发量等参数,对中国南海温差能在季节、年代际的地理分布及其变化特征进行详细分析。结果表明：1)南海大于1000 m水深海域的温差均满足发电净效率的要求,可全年有效开采,温差分布具有明显季节变换特征,夏季最高,秋、春次之,冬季最低,常年高值主要集中在南沙群岛至吕宋岛西部一带。2)中沙群岛以南是卡诺效率高值且月波动较小海区,效率最高月份为5—8月份。3)南海温差能年平均有效水头介于774～945 m,高值主要分布在南海中东部、南部海域,呈西南—东北走向,有效水头在850 m以上;南海中南部、吕宋岛西部海域年际变化呈2.0～3.0 m/a上升趋势。4)南海暖水体积量月变化呈“V”型,冬季8.50×10¹³m³以上,处在较高水平;年际变化0.165×10¹³m³/a,呈增长趋势,年平均7...     

Thermal performance of an electrochromic vacuum glazing

Using a three-dimensional finite volume model, the thermal performance of an electrochromic vacuum glazing was simulated for insolation intensities between 0 and 1200 W m⁻². The electrochromic evacuated glazing simulated consisted of three glass panes 0.5 m by 0.5 m with a 0.12 mm wide evacuated space between two 4 mm thick panes supported by 0.32 mm diameter pillars spaced on a 25 mm square grid contiguously sealed by a 6 mm wide metal edge seal. The third glass pane on which the electrochromic layer was deposited was assumed to be sealed to the evacuated glass unit. The simulations indicate that when facing the indoor environment, the temperature of the glass pane with the electrochromic layer can reach 129.5 °C for an incident insolation of 600 W m⁻². At such temperatures unacceptable occupant comfort would ensue and the durability of the electrochromic glazing would be compromised. The glass pane with the electrochromic layer must therefore face the outdoor environment.