C-5000空气压缩机改造及配件国产化

通过对C-5000空气压缩机填料、活塞环损坏和气缸套拉缸等故障产生原因进行分析，制定相应对策，对C-5000空气压缩机进行改良及配件国产化，延长了C-5000空气压缩机的运行周期，减少了维修费用。     

PLC在水利节制闸同步控制中的应用

大中型节制闸闸门的启闭往往广泛运用双吊点液压启闭机,由于活塞杆的运动不能维持同步,在实际启闭过程中会造成卡死、脱落等安全事故。针对这一问题,设计一个以PLC为核心的闸门自动纠偏系统,将两侧液压缸的活塞杆行程数据反馈给PLC,PLC控制程序判断后发出纠偏指令,控制节流阀流量,达到自动纠偏的目的,从而保证节制闸闸门精确平稳的启闭。通过自动纠偏系统,可有效实现闸门的远程同步控制。     

中小型商用压缩机排气流道声学及阻力特性分析

针对某型号中小型商用压缩机噪声与能效问题,分别对压缩机腔内排气流道的声学和阻力特性进行数值模拟,分析压缩机腔内排气流道中一阶排气孔径、缓冲腔容积和排气路径等结构参数对压缩机传递损失和压力损失的影响。结果表明:增大一阶排气孔径对排气流道声学及阻力性能影响较小;增大缓冲腔容积且增长排气路径可以改善排气流道传递损失,但压力损失增大;进口端面与第一个缓冲腔之间没有明显压降,最大压降发生在内排气管流道中。最终进行样机制作和测试,噪声和制冷量测试结果与数值结果具有较好的一致性。     

客车空调压缩机排气管路失效分析与结构改进

采用ANSYS Workbench软件对客车空调压缩机排气管路进行失效分析和结构改进。以3种典型管路为研究对象,在压缩机端施加位移载荷进行管路失效分析,模拟结果与管路实际断裂位置一致。通过添加弯头、调整管路角度以及增加不锈钢波纹管长度等改进措施,可以降低管路的最大等效应力,延长管路的使用寿命。     

涡旋压缩机涡旋型线的研究现状及展望

涡旋压缩机作为第三代容积式压缩机,具有效率高、能耗低、噪声低、结构紧凑等诸多优点,被广泛应用于制冷空调与气体压缩等方面。由于涡旋压缩机的寿命、加工性能、效率和功耗等都受到涡旋型线的制约,所以涡旋型线的研究是开展涡旋压缩机其他研究的基础和关键。本文总结了国内外相关的研究成果,从型线类型和型线修正两个方面出发,对现有涡旋型线的研究现状进行综述分析,并对未来涡旋型线发展方向和趋势进行预测和展望,对于今后涡旋压缩机型线的研究与工程应用具有指导和借鉴作用。     

单齿转子式压缩机的转子设计与性能分析

基于单齿转子的设计方法与曲线的啮合理论,提出一种新型单齿转子,完善常见型线的啮合模型,构建该新型转子的型线参数方程,分析转子几何参数的关系,利用ANSYS分析新型单齿转子的力学性能。结果表明,所提出的新型单齿转子具有设计合理、设计方法简单、力学性能好的优点。     

A New Mechanism of Light‐Induced Bubble Growth to Propel Microbubble Piston Engine

Radiation pressure refers to the momentum transfer of photons during light “particles” impacting a surface. The force is too small to drive microengines. Different from the classical radiation pressure, the indirect radiation pressure (F_m) is introduced, coming from the momentum change of light‐induced bubble expansion. F_m is shown to obey F_m ～ (I·r_b)², behaving faster growth of indirect radiation pressure versus light intensity I and bubble radius r_b. An effective bubble size range is identified for F_m to suppress other forces for bubble in liquid. The top laser irradiation on nanofluid is used in this experiment. A well‐defined bubble pulsating flow, being a new principle of bubble piston engine, is demonstrated. During pulse on (≈ns scale), F_m exceeding other forces generates an extremely large acceleration, which is three to four orders larger than the gravity acceleration, propelling the bubble traveling downward. During pulse off, the bubble is floating upward due to the nonexistence of F_m. In such a way, the piston engine sustains the oscillating ranges of 38–347 µm for bubble diameters and 2.7–457.9 µm for traveling distances of piston. This work is useful to manipulate bubble dynamics in solar energy systems, and can find various applications in optofluidics.     

基于PCA-Clustering的压缩机回液故障诊断

在多联机(VRF)空调系统中,压缩机回液将导致能量损失。本文结合大数据提出了一种基于PCA-Clustering的压缩机回液故障诊断的方法。首先提取出故障相关变量,并通过数据预处理,剔除异常值与空值;然后将处理后的数据进行主成分分析(PCA),获取降维后的新主元变量数据;最后将新的主元变量进行聚类分析(Clustering analysis)得到回液故障数据分类标签。结果表明:该方法能够在数据标签未知的情况下,较好的区分不同类别的压缩机回液故障及正常数据,使压缩机回液故障诊断率达到94.29%。     

A cryogen-free Vuilleumier type pulse tube cryocooler operating below 10 K

Vuilleumier (VM) type pulse tube cryocooler (PTC) utilizes the thermal compressor to drive the low temperature stage PTC. This paper presents the latest experimental results of a cryogen-free VM type PTC that operates in the temperature range below 10 K. Stirling type pre-coolers instead of liquid nitrogen provide the cooling power for the thermal compressor. Compared with previous configuration, the thermal compressor was improved with a higher output pressure ratio, and lead and HoCu₂ spheres were packed within the regenerator for the low temperature stage PTC for a better match with targeted cold end temperature. A lowest no-load temperature of 7.58 K was obtained with a pressure ratio of 1.23, a working frequency of 3 Hz and an average pressure of 1.63 MPa. The experimental results show good consistency in terms of lowest temperature with the simulation under the same working condition.