Dynamic counterbalancing the single-piston linear compressor of a Stirling cryogenic cooler

Low vibration Stirling cryocoolers often rely on dual-piston linear compressors, the known disadvantages of which, as compared to their single-piston rivals, are: low reliability, increased power consumption, price, bulk, sensitivity to external vibration and g-forces. However, because of the inherently low level of vibration export, as required in numerous vibration sensitive electronic and electro-optic applications, the dual-piston approach has become prevalent in today’s industrial practice.The authors report on the novel approach to the passive control of a fundamental component of a vibration export from a single-piston compressor down to the levels typical for the actively controlled dual-piston rival. The technique relies on the newly proposed principle of dynamic counterbalancing, where an auxiliary movable mass is flexibly attached to a movable piston assembly and to the stationary compressor casing using auxiliary mechanical springs. The proper design of such a “spring-mass-spring” counterbalancer yields zero vibration export at minimum electrical power and current consumed by the motor.Based on the theoretical analysis, the design of the single-piston compressor of 1 W@77 K Ricor model K529N Stirling cryocooler was enhanced by adding such a counterbalancer. The obtained experimental results are in full agreement with the theoretical prediction. From experiment, the vibration export at driving frequency was reduced 57-fold at practically the same electrical current and power consumed by the compressor actuator as compared with the basic cooler.     

新集一矿压缩机自动化控制可行性方案的探讨

针对新集一矿压风机单启、单控的局面,提出了一种可行的自动化控制方案,推进高新技术的普及应用,为矿井自动化控制优化设计提供参考。     

9E燃气轮机的压气机控制和保护

介绍了轴流式压气机的功能、特性以及9E压气机的性能和结构特点,分析了其控制和保护功能,包括进口导叶的控制、防喘放气阀的控制、压气机运行限制保护和机组的遮断保护,对压气机的安全运行和设计优化有所帮助.     

A study on integrated design conjugation profiles application analysis of scroll profiles for automobile air conditioning

The research on scroll profiles theory at present mainly is aiming at the single profile and its amelioration or parameter optimization,not aiming at the natural characteristic of the profiles equation of scroll profiles itself.Thus,the intrinsic differential equation bearing on arc-length and tangent direction angle was studied.Using the inherent differential equation and general functional theory,the conversion ideas between the expression of intrinsic differential equation and the expression in Cartesian...     

氢气压缩机机封冷却水循环利用改造

针对18万t/a离子膜烧碱装置中氢气处理系统的氢气压缩机机封水压力不稳定等问题,对工艺进行了改造,改造后的生产工艺安全、稳定,每年可节约电费14.26万元,节约水费3.8万元。     

动力用空气压缩机能源效率探讨

分析了压缩空气的能量过程、动力用空气压缩机整机的能源效率和压缩空气的做功能力,提出输功效率作为考核空气压缩机的转化能源效率。指出几种空气压缩机效率只有10%左右说法是错误的。     

变频压缩机电机电感仿真与测试方法的研究

随着对变频压缩机高能效的深入研究,永磁辅助同步磁阻电机得到了愈来愈多的应用。对于永磁辅助同步磁阻电机而言,交、直轴电感对电机性能的影响很大。本文针对永磁辅助同步磁阻电机电感仿真及测试方法进行分析,提出一种比较实用的d、q轴电感仿真及测试方法。利用提出的电压积分法进行电感参数测试试验,测试结果基本与仿真值相符合,最后利用比较输出电磁转矩方法验证仿真及测试方法的准确性,具有很高的实用参考价值。     

带有根部间隙的压气机静子通道流场测量

为了研究静子根部间隙对压气机性能的影响,设计了4支不同长度的“L”形五孔探针和1支四孔探针。通过位移机构移动上述探针,对某双级低速轴流压气机在不同流量工况下的5个不同轴向位置的静子通道截面流场进行了实验测量。实验结果表明,在最大流量和近失速工况下,根部间隙引起的泄漏流和叶尖处的角区分离流与主流的掺混始终是造成静子通道内 总压损失的主要原因。随着进口流量的减小,泄漏流和角区分离的起始位置将更靠近通道进口。     

结构参数对内啮合转子压缩机受力特性的影响

在分析内啮合转子压缩机独立结构参数对转子影响的基础上,通过定义2个相对结构参数,将影响较大的3个独立结构参数关联在一起,研究了相对结构参数对工作腔压力分布、转子上承受的气体力和气体力力矩以及主轴驱动力矩的影响。研究结果表明,λe对气体力和内外转子上的气体力矩影响较大,随着λe的增大,气体力逐渐减小,内外转子上承受的气体力矩波动加剧,特别是当λe增大到一定值后,外转子上气体力矩会始终为负;λa对主轴驱动力矩影响较大,随着λa的增大,驱动力矩的平均值和变化幅度均增大。在不考虑其他因素的情况下,选择较大的λe和较小的λa对改善压缩机受力情况有利。研究结果可为内啮合转子压缩机的设计及结构参数优化提供一定的参考。     

Global optimality properties of total annualized and operating cost problems for compressor sequences

The minimum total annualized cost problem for a series of nonisentropic compressors and coolers that brings a gas with constant compressibility factor from a specified initial pressure and temperature to a specified final pressure and the same temperature is studied in this work. It is established analytically that at the global optimum, the cooler outlet temperatures are equal to the minimum allowable temperature. For constant heat capacity, constant compressibility factor gases, additional properties of the globally optimal compressor sequence are analytically established for the minimum operating cost case. The aforementioned properties permit development of a solution strategy that identifies the globally minimum operating cost. Several case studies are presented to illustrate the developed theorems and solution strategies. © 2014 American Institute of Chemical Engineers AIChE J 60: 4134–4149, 2014