20W@80K空间大冷量脉冲管制冷机试验研究

空间应用对于80K温区的冷量需求日益增加，然而国内空间大冷量脉冲管制冷机的研究起步较晚，目前制冷机的冷量不能满足红外探测的发展需求。为了进一步提高脉冲管制冷机的制冷量，研制了一台由线性压缩机驱动的小型脉冲管制冷机。通过试验研究了调相机构、充气压力、输入功率等因素对脉冲管制冷机制冷性能的影响规律，并测试了降温速率，探究了调相机构对压缩机输出功率的影响等。研制出的制冷机在输入电功率为350 W，热端温度为300 K时，在80 K获得了20.5 W的制冷量，整机的相对卡诺效率达到了16.1%。     

滚动转子式压缩机泵体输入功率的计算

在确立的假设条件下,对叶片、滚套、曲轴等滚动转子式压缩机各关键运动部件进行了动力学分析,得出了压缩机泵体的输入功率表达式。为压缩机设计提供了理论基础。     

An Autonomous Sorption Refrigerator for Cooling to 0.3 K

A two-stage refrigerator with sorption evacuation of ⁴He and ³He is described. The apparatus needs no external pumps or gas lines. The refrigerator is constructed in the form of an insert 80 mm in diameter immersed in a helium cryostat and ensures a sample temperature of 0.31 K for 20 h after the condensation of ³He at a useful heat load of 10 W. The recycling time is 0.5 h.     

Invited article: millimeter-wave bolometer array receiver for the Atacama pathfinder experiment Sunyaev-Zel'dovich (APEX-SZ) instrument

The Atacama pathfinder experiment Sunyaev-Zel'dovich (APEX-SZ) instrument is a millimeter-wave cryogenic receiver designed to observe galaxy clusters via the Sunyaev-Zel'dovich effect from the 12 m APEX telescope on the Atacama plateau in Chile. The receiver contains a focal plane of 280 superconducting transition-edge sensor (TES) bolometers instrumented with a frequency-domain multiplexed readout system. The bolometers are cooled to 280 mK via a three-stage helium sorption refrigerator and a mechanical pulse-tube cooler. Three warm mirrors, two 4 K lenses, and a horn array couple the TES bolometers to the telescope. APEX-SZ observes in a single frequency band at 150 GHz with 1' angular resolution and a 22' field-of-view, all well suited for cluster mapping. The APEX-SZ receiver has played a key role in the introduction of several new technologies including TES bolometers, the frequency-domain multiplexed readout, and the use of a pulse-tube cooler with bolometers. As a result of these new technologies, the instrument has a higher instantaneous sensitivity and covers a larger field-of-view than earlier generations of Sunyaev-Zel'dovich instruments. The TES bolometers have a median sensitivity of 890 μK(CMB)√s (NEy of 3.5 × 10(-4) √s). We have also demonstrated upgraded detectors with improved sensitivity of 530 μK(CMB)√s (NEy of 2.2 × 10(-4) √s). Since its commissioning in April 2007, APEX-SZ has been used to map 48 clusters. We describe the design of the receiver and its performance when installed on the APEX telescope.     

浅谈螺杆压缩机故障原因分析及处理

阐述了制冷压缩机22W480系统的工艺原理,分析了压缩机蒸发器E484、E496液位高高报警联锁故障原因,压缩机丙烯冷却器E003液位高高报警联锁及润滑油问题导致压缩机故障原因,论述了压缩机分离器分离效果较差原因,彻底解决了压缩机停机故障和制冷效果差的难题.     

High frequency pressure oscillator for microcryocoolers

Microminiature pulse tube cryocoolers should operate at a frequency of an order higher than the conventional macro ones because the pulse tube cryocooler operating frequency scales inversely with the square of the pulse tube diameter. In this paper, the design and experiments of a high frequency pressure oscillator is presented with the aim to power a micropulse tube cryocooler operating between 300 and 80 K, delivering a cooling power of 10 mW. Piezoelectric actuators operate efficiently at high frequencies and have high power density making them good candidates as drivers for high frequency pressure oscillator. The pressure oscillator described in this work consists of a membrane driven by a piezoelectric actuator. A pressure ratio of about 1.11 was achieved with a filling pressure of 2.5 MPa and compression volume of about 22.6 mm(3) when operating the actuator with a peak-to-peak sinusoidal voltage of 100 V at a frequency of 1 kHz. The electrical power input was 2.73 W. The high pressure ratio and low electrical input power at high frequencies would herald development of microminiature cryocoolers.     

级间冷却器对L3.3K-15/300型空压机运行参数的影响

针对空压机的运行状况,确认问题症结在于冷却器,并进行了理论计算,通过对空压机级间冷却器进行检修,分析检修前后压缩机运行参数的变化,得出级间冷却器对空压机运行参数的影响,以及及时保养检修的重要性。     

“一拖三”氦压缩机低成本控制实现

利用电路印刷板用小型继电器及增强型51单片机,实现对大气量氦压缩机的低成本控制,使其同时可以为3台G-M制冷机提供高压氦气。控制器采集压缩机运行相关参数,具备必要的保护措施,并实现远程控制。在完成控制功能的同时,使整个控制系统的体积和成本得到有效控制。     

CO_2热泵热水器的系统设计及试验研究

设计搭建了蒸发器和气冷器均采用套管式换热器的跨临界CO2热泵热水器性能测试试验台,在制冷剂充注量1.23kg时,通过调节膨胀阀的开度和控制气冷器的水流量来研究系统性能。结果表明:该机组能在较高COP(3.2)下制得65℃的热水,并可以在COP不低于2.0情况下制取80℃的热水;气冷器水流量对系统的COP、出水温度以及系统的排气压力影响最大;高效的换热器可以在压缩机排气温度一样的情况下提高出水温度,使系统在制取高温水时有更高的COP。     

Determination of deposit thickness in natural gas cooler based on the measurements of gas cooling degree

An original method for estimating fouled deposit thickness on the inside surfaces of natural gas cooler tubes is presented. This method does not require opening and inspecting a cooler as it is based on the measurement of gas cooling degree, i.e. the gas temperature difference between the cooler inlet and discharge. The deposit layer on the internal heat transfer surfaces is of semi-liquid consistency and its thermal conductivity coefficient has not been investigated until now. This paper describes the experimental determination of the deposit thermal conductivity coefficient. This parameter enables determination of a cooler’s performance as a function of current deposit thickness. Practical application of the method is illustrated in the case of CH_R cooler working in the KS01 compressor station in Vel’ké Kapušany, Slovakia. For this type of cooler, a diagram for deposit thickness as a function of the gas cooling degree is presented.     

Influence of water injection parameters on the performance of a water-lubricated single-screw air compressor

A thermodynamic model of a water-lubricated single-screw air compressor was established to examine the impact of water injection parameters on performance. Heat transfer and leakage between humid air and water was considered by analyzing the impacts of rotation speed, discharge pressure, the rate of water injection, and diameter of droplets on the performance of a compressor. The discharge temperature could be reduced by increasing the rate of water injection, resulting in the compression procedure moving towards an isothermal state. The increase in the rate of water injection under rated conditions from 60 L/min to 80 L/min resulted in a reduction in the compressor discharge temperature, increased the volume efficiency, and increased adiabatic efficiency by 11.1 K, 1.5 %, and 2.8 %, respectively. Water injection atomization increased the area of transfer of heat between humid air and water and improved the performance of compressor.

     

涡旋压缩机涡圈渐开线的创成与加工

研究了涡旋压缩机的"心脏"——运动涡旋盘渐开线的创成和编程加工,根据涡旋压缩机渐开线的特性和原理,以及加工零件的精度要求,推导出加工零件的渐开线方程式,从而使编程更加简单,使用更加方便,并使加工精度得到提高。     

静止叶片式空气压缩机的研究

提出了一种新型静止叶片式空气压缩机,该压缩机具有一个做摆动运动的转子和一个静止不动的叶片,叶片的外端与气缸的内孔壁面密封紧固连接,叶片的侧端与端盖密封紧固连接,借此减少了气体直接从压缩腔向吸气腔窜逸的通道,有效地消除了压缩机在这些部件间的泄漏损失和摩擦损耗。介绍了压缩机的结构特点及工作原理,建立了压缩机的数学模型。研究表明:转子的扭摆惯性力矩对滑块与叶片运动副的摩擦及磨损有较大影响,应减小转子的转动惯量以降低滑块与叶片间的接触力;转子与端盖的轴向间隙对压缩机内部泄漏损失十分敏感,应采取轴向密封措施以减少转子轴端处的泄漏量。     

Upgrade of far-infrared laser-based Faraday rotation measurement on MST

Recently, the far-infrared (FIR) laser (λ(0)=432?μm) Faraday rotation measurement system on MST has been upgraded. The dc flowing-gas discharge CO(2) pump laser is replaced by a rf-excited, sealed CO(2) laser at 9.27?μm (GEM select 100, Coherent Inc., Santa Clara, CA), which is subdivided equally into three parts to simultaneously pump three FIR cavities. The total infrared pump power is approximately 80 W on the 9R(20) line required to pump the formic acid molecule. Each FIR cavity produces ～12?mW, sufficient for 11 simultaneous chord interferometry-polarimetry operations. Three key issues [(1) conservation of circularly polarized wave, (2) colinearity of two probe waves, and (3) stability of intermediate frequencies between lasers] affecting the Faraday rotation measurement have been resolved experimentally.     

努森压缩机的研究进展

努森压缩机是一种以微/纳尺度下的热流逸效应为工作原理的元器件,仅由一组微通道和一个连接通道组成,其结构简单、无运动部件、可利用低品位热能。讨论了努森压缩机的结构特点,总结了近期国内外关于努森压缩机的升压能力、流量、效率等方面的研究概况与进展。对现有的几种努森压缩机微通道材料进行了对比分析,并概览了目前努森压缩机的一些实际及潜在的应用领域。最后,根据努森压缩机的特点以及现有研究的不足,探讨了未来努森压缩机的研发趋势。     

基于Pro/E和Adams软件的涡旋压缩机虚拟样机研究

介绍利用Pro/E软件对涡旋压缩机零部件建模及虚拟装配,简述了从Pro/E软件导入Adams软件、建立Adams环境下的涡旋压缩机的过程,分析了各运动件的运动仿真,为后续运动学和动力学分析提供条件。     

单侧弹簧线性压缩机可行性实验研究

对一种新型单侧弹簧动磁式线性压缩机的样机进行了空气压缩实验研究,验证了其可行性.通过实验结果可以看出,单侧弹簧线性压缩机具有利用压缩气体作为气体弹簧来减少谐振弹簧的用量,同时减少压缩机运动部件质量,实现线性压缩机轻型化的优点.同时实验结果还表明,在一定的排气压力下可以通过控制电压值来让压缩机活塞达到上死点位置.     

Compact terahertz passive spectrometer with wideband superconductor-insulator-superconductor mixer

We developed a compact terahertz (THz) spectrometer with a superconductor-insulator-superconductor (SIS) mixer, aiming to realize a portable and highly sensitive spectrometer to detect dangerous gases at disaster sites. The receiver cryostat which incorporates the SIS mixer and a small cryocooler except for a helium compressor has a weight of 27 kg and dimensions of 200 mm × 270 mm × 690 mm. In spite of the small cooling capacity of the cryocooler, the SIS mixer is successfully cooled lower than 4 K, and the temperature variation is suppressed for the sensitive measurement. By adopting a frequency sweeping system using photonic local oscillator, we demonstrated a spectroscopic measurement of CH(3)CN gas in 0.2-0.5 THz range.     

二氧化碳汽车空调器变工况性能分析

建立了超临界二氧化碳汽车空调器循环计算模型,结合美国Ｉｌｌｉｎｏｉｓ大学制冷空调中心（ＡＣＲＣ）二氧化碳汽车空调样机实验结果,对两种压缩机转速和两种气体冷却器空气进口温度的不同组合条件下的工况,进行了循环计算,并对计算结果作了分析。计算结果表明,压缩机转速越高,或者气体冷却器空气进口温度越高,二氧化碳汽车空调的工部越恶劣,ＣＯＰ值越低。     

压缩机级间冷却冷凝析水量计算

对压缩机的湿气体级间冷却器冷凝水的问题进行了详细的分析，确定了冷却器中是否存在冷凝水析出的判别式，给出了级问冷却器中析水量的计算实例，结果表明计算值与实测值一致。