往复式冰箱压缩机噪声分析及控制方法综述

针对往复式冰箱压缩机的噪声问题,介绍了往复式冰箱压缩机噪声的产生机理以及传递路径,归纳和总结了目前往复式冰箱压缩机噪声控制方法,并在此基础上提出了一些新的降噪方法,最后,介绍了噪声控制方面的新技术和利用有限元/边界元工具进行噪声控制,重点介绍新的方法和技术。     

我国容积式制冷压缩机名义工况一致性研究

论述了我国容积式制冷压缩机标准名义工况一致性研究的需求,总结了中国、美国和欧洲现行相关标准的名义工况现状,发现现行标准工况中蒸发温度、冷凝温度等关键参数存在较大的不一致性。介绍了中美标准研究进展,归纳出新的压缩机标准工况参数在向一致性方向发展,且更加符合压缩机在主机中的实际应用情况。提出建立我国容积式制冷压缩机标准名义工况一致性的具体的研究工作方向。     

压缩机示功图录入方法的改进研究

介绍了活塞式压缩机示功图的录入方法,并结合实际情况,研究开发了一套新的实验方法,很好地解决了活塞式压缩机压力的实时采集和示功图的的动态显示。     

数码涡旋多联机制热控制策略的研究

针对多联机常规的制热控制策略导致系统运行不稳定的特性,提出新的控制策略,建立了压缩机输出比控制模型和压缩机切换控制模型,设计一套10HP数码涡旋多联机系统进行验证.控制模型中以一个周期时间内排气压力的平均值作为当前压力值按照给定的目标压力区域来调节压缩机输出比,并给出了控制模型中的目标压力基准值的确定原则.压缩机切换控制策略中,设置数码压缩机为优先级高的压缩机,调节其输出能力,直到100％输出比,再切换启动定频压缩机,有利于提高性能系数.实验证明这种控制策略对提高系统运行的稳定性、可靠性以及性能系数是可行的.     

滚动转子式压缩机的技术现状及发展趋势

滚动转子式压缩机广泛应用于房间空调器中,长期以来针对这类压缩机开展了大量的研究。然而近年来一些形势变化对其提出了新的发展要求,如节能、环保以及应用领域的拓展,分析其技术状况和发展趋势就显得尤为重要。本文介绍滚动转子式压缩机技术现状和发展,指出滚动转子式压缩机未来技术研究重点是产品的高效节能、变容量、小型化、低噪声和高可靠性,同时,开发环境友好型制冷剂专用压缩机以应对HCFCs和HFCs制冷剂的淘汰是未来的一个重要发展方向。     

浅析空压机行业服务模式创新趋势

正目前,受国家经济增速放缓、固定投资疲软和出口业务萎靡影响,整个压缩机行业普遍遭遇"寒冬"。当供需端尚未出现明显改善的前提下,压缩机低价的状态仍会持续。面对如此形势,创新是帮助压缩机企业走出阴霾的法宝之一。可是在遇到困境时,急于走出寒冬的压缩机企业究竟该如何创新?业内人士认为,只要不断推出新的产品和服务就是创新,但市场对此并不一定领情。因为总有其他公司可以做得更好。还有的压缩机人认     

国产大型轴流压缩机在陕鼓动力诞生

<正>2012年5月15日,国产单机压比最大的轴流压缩机组AV100-22在西安陕鼓动力股份有限公司(以下简称:陕鼓动力)一次试车成功,标志着国产轴流压缩机技术水平和综合能力又上了一个新的台阶。该压缩机组是陕鼓动力为国防某高空飞机发动机试验     

螺杆式制冷压缩机及其应用

一、螺杆式制冷压缩机的发展及其特点螺杆式制冷压缩机早在1878年已经问世,但没有实用意义。直到1934年瑞典科学家重新进行研制,并获得成功。1963年发明了第一台喷油螺杆式制冷压缩机。同年荷兰某肉类冷库已开始应用这种新型机器。欧美、日等工业发达国家已率先将螺杆式制冷压缩机应用于陆用或船用的冷库制冷系统、空调系统、工业制冷装置等。许多生产厂家为了提高螺杆效率及降低其噪音方面,进行新的转子型线及其它方面的研究和试验。     

基于专家PID的变频空调频率调节方法研究

本文提出了一种基于专家PID的新型压缩机频率调节方法,将工程师的专家经验植入PID参数,从而实现空调器快速制冷,快速制热,精确控温,舒适节能的目标。笔者从理论和实验两个方面阐述了专家经验在空调器压缩机频率控制的关键作用,提出了具体的调节方法,为变频空调器压缩机频率控制提供了新的思路和方向。     

世界制冷技术发展动向

据美国制冷专家的预测,随着科技水平的提高,世界制冷技术将会有新的进展,进入新的领域,其发展动向有以下3方面:1.新材料被广泛应用。新的致冷剂氯氟碳化物将加速替代氟里昂。制冷润滑油也将更新,其粘度/温度系数更适于高温、高速的压缩机。无润滑油的全陶瓷压缩机也将有可能问世。2.新机械被大批推广。旋转式、螺杆式、涡漩式和摆线式4种压缩机进入实用阶段。驱动     

Commercial refrigeration and CFCs

Copeland Corporation acknowledges the contribution of CFCs to the depletion of the stratospheric ozone layer. Copeland endorse the view that CFCs should be completely phased out by the year 2000 for new refrigerant applications and that the time schedule for phase out proposed in the Montreal Protocol should be accelerated. Copeland is taking a three-stage approach to the CFC problem, concentrating on the elimination of CFC-12 and CFC-502 and substituting HCFC-22 prior to the commercial availability of alternative refrigerants. The stages are as follows. (1) Eliminate CFC-12 by providing compressors which use HCFF-22 (down to -10°F) and CFC-402. (2) Modification of existing compressors to use HCFC-22 for applications down to -40°F evaporating temperature. This can be achieved by additional air-cooling on small compressors, demand cooling for large, single compressor units, or staging for multiple compressor applications. (3) Development of compressors for new refrigerants. The problems here include the high compression ratios required by HFC-134a, which result in a major loss in capacity compared to reciprocating compressors at medium and low temperatures. HFC-125 has a low critical temperature which limits its application and efficiency in high condensing temperature applications. Lubricating oils used with HFC-134a have a detrimental effect on some motor insulation materials and polymers; wear is also higher. Scroll compressor technology appears to have several advantages over reciprocating compressors in overcoming these problems in the long term.     

Electrical properties of CFC- and HCFC-substitutes

Electrical properties of refrigerants are of importance as soon as bushings are surrounded by a refrigerant. This is the case e. g. for hermetic sealed motor compressors as well as for some control devices such as liquid level control units or capacity controls for compressors. This paper presents a survey of existing data for HFC refrigerants and presents new measurements for those HFC blends that have been identified as long term replacements for CFCs and HCFCs. The data collection includes permittivity, electrical conductivity and breakdown voltage. Values are given for the HFC blends R404A, R407C, R410A and R507 as well as for R134a.     

80000m~3/h空分设备压缩机群联网控制改造设计

广西杭氧80000 m3/h空分设备项目配套的压缩机组,由新建机组和利旧机组集合而成,共有18台。为保证整套设备安全运行,必须将这些机组组合成一个完整系统,并实现机群的联网控制。简介压缩机群网络的构成,从保证机群系统的可操作性和安全保障等方面,阐述压缩机群联网控制的改造设计。     

Hermetic compressors — a case study

Since the energy crisis, Danfoss have been working systematically on their hermetic compressors for household refigerators and freezers. Significant savings in energy consumption have been achieved, both from improvements to existing designs and from a new design of the smallest compressors.The improvements and results achieved are presented here.     

Practical sensorless control for inverter-fed BDCM compressors

Brushless DC motors (BDCMs) possess higher efficiencies than the conventional induction motors and BDCMs have therefore been used widely in inverter-fed compressors. Since the Hall position sensors cannot work well in the high-temperature environment of refrigerants, sensorless control schemes play an important role in the application of inverter-fed BDCM compressors. Sensorless control for actual BDCM compressor is proposed and implemented. First, the sensorless circuits used have been analysed in detail to find the design rules of the circuit parameters for various compressor motors. Then, the limitations of sensorless control are discussed to develop a practical speed controller for BDCM compressors. The developed starting strategy and sensorless algorithms are presented and digitally implemented. Finally, some experimental results are displayed to demonstrate the proposed sensorless speed control for BDCM compressors.     

A heat transfer correlation for the suction and compression chambers of scroll compressors

Heat transfer in the suction and compression chambers of scroll compressors has not been sufficiently studied and typical correlations available in the literature are based on simplified flow conditions. This paper presents the results of a model developed to predict fluid flow and heat transfer inside the suction and compression chambers of scroll compressors. Due to the particular geometry of scroll compressors, an algorithm was developed to adapt the computational mesh automatically for each orbiting angle. Convective heat transfer is strongly affected by the flow in the near-wall region and for this reason a low-Reynolds-number turbulence model was adopted in the simulations. The study covered a wide range of operating conditions and geometric parameters, allowing the proposal of a characteristic velocity for the flow inside the suction and compression chambers and a new heat transfer correlation for scroll compressors, which is compared with other correlations adopted in the literature.     

New non-dimensional performance parameters for the characterization of refrigeration compressors

Pierre (1982) developed general correlations of compressor performance for a wide range of open piston compressors based on a vast amount of data provided by the most important open compressors manufacturers at that time. Based on a wide experimental test campaign with 6 different hermetic and semihermetic compressors, this paper assesses the potential of Pierre's correlations to describe the performance of modern compressors. A full review of the functionals proposed by Pierre in order to improve their accuracy was then performed and as a result the authors found that it is possible to improve the characterization by employing a nondimensional definition of the compressor performance instead of using the efficiencies. These new parameters provide a much more consistent estimation at the borders of the correlation range than the usual correlation obtained following the ARI standard, and could be even employed to extrapolate the performance of the compressor to non-tested conditions with reasonable accuracy.     

轴流压气机旋转失速和喘振的非线性反馈控制

旋转失速和喘振是轴流压气机中的两种主要的不稳定工作形式,限制了压气机稳定工作范围。本文中提出了一种新的对旋转失速和喘振的非线性反馈控制策略,即把压升作为反馈信号,来补偿节流阀系数值。研究结果表明,这种控制策略很简单,但是能够消除失速时伴随的迟回效应;也能够增加压气机的喘振裕度。     

经济器的选型及使用探讨

本文介绍了制冷系统常用的经济器的一些类型,螺杆压缩机在应用配套经济器时不同工况的一些计算数据和使用方法.     

分离型二级脉管制冷机的实验研究--Ⅱ:液氦温区二级脉管制冷机

研制1台新型液氦温区分离型二级脉管制冷机,该制冷机由2台独立的脉管制冷机组成,一级回热器冷端和二级回热器中部通过热桥相连,从根本上弥补了传统直接耦合型多级脉管制冷机级间干扰的不足.采用双压缩机双旋转阀驱动该二级脉管制冷机,第二级最低温度达到了2.5 K,在4.2 K下有508 mW制冷量,同时一级在37.5 K有15 W制冷量.第二级充气压力由1.7 MPa增大到1.85 MPa,制冷机在4.2 K下的制冷量可以达到590 mW.为了能简化结构、扩大应用,提出采用单压缩机单旋转阀驱动该分离型脉管制冷机,达到了相同的制冷性能.