用于低温复叠式制冷的CO2螺杆式压缩机组的性能实验

CO2在冷冻冷藏系统中适宜作为低温级制冷剂与其他制冷剂组成复叠式制冷循环。建立采用螺杆式压缩机组的NH3/CO2复叠式制冷实验系统,对低温级的CO2螺杆式压缩机组进行性能测试,并对主要技术参数进行分析,给出机组制冷量、轴功率、容积效率和绝热效率等在不同工况下的变化关系。在相同工况下CO2制冷机组的制冷量约是同型号氨机组的7.5～10.5倍,且在蒸发温度越低时差值越大。对NH3/CO2复叠式制冷机组和NH3单机双级压缩制冷机组的性能系数进行比较,前者在蒸发温度低于-40℃时性能系数更高。     

远置式陈列柜制冷电能消耗理论分析

基于远置式陈列柜能效标准和冷藏陈列柜标准,以半封闭压缩机性能参数表进行计算,分析工质、压缩机容积、蒸发温度、频率等参数对远置式陈列柜制冷电能消耗的影响。结果发现R134a计算值偏离实验值程度最小;小压缩机并联比使用大压缩机能获得更低的制冷电能消耗偏离系数;较高的蒸发温度,可以使得实际制冷电能消耗减少,但是相应的会导致计算值偏离实际值的程度增加;压缩机频率较低可以使得计算偏离系数较小。     

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。     

《CO2制冷压缩机》标准探讨

针对正在起草的国家标准《CO2制冷压缩机》,阐述标准制定的背景,详细论述主要技术参数＂名义工况＂的确定依据,介绍其性能试验方法,并提出制冷剂跨临界气体冷却法的性能测试方法。     

GB/T《容积式制冷剂压缩机容积流量试验方法》国家标准制定进展

容积式制冷剂压缩机产品量大面广,对其进行容积流量检测,是制造商对自身产品出厂性能摸底和进行质量合格性判定的重要依据。本文在系统调研行业企业测试技术现状的基础上,针对单级容积式制冷剂压缩机(组)容积流量的试验方法开展了标准化研究,并对国家标准GB/T《容积式制冷剂压缩机容积流量试验方法》的起草背景、起草过程、测试技术现状和测试方法标准化进行了详细介绍。     

基于(火用)分析的内可逆简单空气制冷循环性能优化

基于(火用)分析的观点,运用有限时间热力学方法分析恒温热源内可逆简单空气制冷循环的特性,导出制冷率、生态学目标函数和(火用)效率与压缩机压比等主要影响参数的解析式,以相应的数值计算分析压缩机压比、高低温侧换热器热导率分配对循环性能优化的影响特点,并把生态学优化目标、(火用)效率优化目标和传统的制冷率优化目标进行综合比较.所得结果对工程制冷系统设计具有一定的指导意义.     

氨用活塞式制冷压缩机制冷量,轴功率经验计算式

本文依据国内名牌冷冻机厂产品样本提供的氨用活塞式制冷压缩机性能数据,根据最小二乘法进行拟合回归出氨用活塞式制冷压缩机制冷量、轴功率的经验计算式,最后经过修正和经过各厂家生产的压缩机性能数据验证,得出了精度能满足工程需要的氨用活塞式单级制冷压缩机通用性能计算式,和仅适合于几个厂家生产的非通用双级制冷压缩机性能计算式。这些经验计算式可以阐明国内生产的制冷压缩机的性能和制冷系统中冷凝湿度、蒸发温度的关系。不仅为制冷系统优化设计及数值设计计算提供了数学模型,而且对制冷压缩机的变工况性能试验及制冷系统的生产管理也有一定应用价值。     

容积式制冷压缩机性能试验中排气压力对制冷量测量不确定度的影响初探

针对容积式制冷压缩机性能试验中影响制冷量测量不确定度的各种因素,通过对小型全封闭活塞式压缩机的热力性能模拟,分析得出了压缩机排气压力对制冷量不确定度的影响关系.     

高效螺杆式CO2制冷压缩机的优化设计

在对螺杆式CO2制冷压缩机的转子进行优化的基础上,对相应的壳体强度、轴承选择、油路布置等进行优化设计,根据优化设计参数制造螺杆式CO2制冷压缩机样机并进行测试。试验结果表明,优化设计后的螺杆式CO2制冷压缩机具有很高的效率及可靠性。     

余隙容积对滚动转子式压缩机性能影响的试验研究

在分析余隙容积对滚动转子式压缩机性能影响的基础上，对滚动转子式压缩机的余隙容积做了部分改进并进行试验研究。试验研究结果表明：余隙容积对滚动转子式压缩机的性能有较大影响，余隙容积减小后压缩机的性能明显提高；改进样机较原压缩机的制冷量增大2．43％、COP增大3．23％；然而余隙容积减小后，因共鸣腔容积的减小导致压缩机噪声较原压缩机有所增加，但仍能够满足国家的标准66dB要求。     

容积式制冷压缩机电效率分析

对制冷压缩机的发展进行了简单的概述,统计计算了市场上几种主要容积式压缩机的电效率,并进行了对比和分析,结果表明： 涡旋压缩机的电效率基本上在0.5~0.75之间,主要集中于0.6~0.7之间;活塞压缩机的效率基本上在0.4~0.7之间,而主要集中于0.5~0.65之间;螺杆压缩机的电效率基本在0.5~0.75之间,主要集中于0.65~0.75之间;压比为2~4时压缩机电效率达到最大。为制冷压缩机的设计、校核和计算提供基础和依据,为制冷系统的性能改进提供方向。     

Test results of performance and oil circulation rate of commercial reciprocating compressors of different capacities working with propane (R290) as refrigerant

In this experimental investigation five R407C positive displacement hermetic reciprocating compressors, covering different capacities, displacement, stroke-to-bore ratios and number of cylinders, have been characterized using propane as refrigerant by means of a specifically designed characterization test rig. Test results have been systematically compared with their R407C reference performance data to obtain a complete picture on changes on the volumetric efficiency and compressor efficiency amongst others. The compressors used POE oil as lubricant and additional oil circulation rate (OCR) tests at steady state conditions were done to evaluate possible effects and differences to the traditionally used mineral oils.     

小型制冷压缩机瞬态起动特性研究

在小型制冷系统中，转子式压缩机的制冷效果不及往复式压缩机，因而限制了转子式压缩机的推广应用。利用作者研制的起动电流测试装置，对不同结构的小型压缩机的瞬态起动特性进行了实验研究，提出了阻止工质在停机后的质量迁移来提高转子式压缩机制冷效果的观点．并进行了压差起动可靠性试验。本研究工作为转子式压缩机在小型制冷系统上的推广应用提供了理论依据。     

Numerical simulation and experimental validation of vapour compression refrigeration systems. Special emphasis on CO2 trans-critical cycles

A numerical and experimental comparative study of a carbon dioxide trans-critical refrigerating system and a conventional sub-critical refrigerating cycle is presented. Attention is focussed not only on the whole refrigeration cycle, but also on the behaviour of the hermetic reciprocating compressors used in these systems. The comparative cases presented have been specially designed for small cooling capacity units with an evaporation temperature around 0 °C. A detailed numerical simulation model for hermetic reciprocating compressors performance, widely validated under conventional fluid refrigerants, has been extended to numerically obtain the CO₂ compressor prototypes behaviour. Two CO₂ compressor prototypes working with CO₂ have been experimentally tested in a specific unit, specially designed and built to analyse high-pressure single stage vapour compression trans-critical refrigerating equipments. This set-up has allowed validating a detailed numerical simulation code for the thermal and fluid-dynamic behaviour of single stage vapour compression refrigeration system working with CO₂ as fluid refrigerant. The numerical results and the experimental data obtained to validate compressors, heat exchangers and whole cycle behaviour have shown a really good agreement. Finally, the numerical and experimental comparison between the carbon dioxide system and the sub-critical conventional cycle has shown the possibility of CO₂ as fluid refrigerant under the studied working conditions.     

Testing and modelling of an automotive wobble plate compressor

Wobble plate compressors are well used in air conditioning for high-class automobiles. They allow continuous control by automatic adjustment of the piston stroke, to keep the low pressure above a certain limit. Here an externally controlled wobble plate compressor is analyzed experimentally through its isentropic and volumetric effectivenesses and control characteristics. Compressor effectivenesses depend mainly on the compressor speed and pressure ratio: there is obtained, for example, isentropic and volumetric effectivenesses of 0.65 and 0.8 for a pressure ratio of 4 at 1000 rpm and 0.4 and 0.35 for the same pressure ratio at 4000 rpm. This degradation is attributed to the increasing of the supply pressure drop. The “lubricant” (oil + dissolved refrigerant) mass flow rate is obtained by minimization of the residuals of the thermal balances on the compressor, condenser and evaporator. Here an important oil-flow circulation is obtained: between 9.5% and 12.5% of the refrigerant flow rate. A special displacement sensor is used to measure instantaneous piston stroke and to relate it to overall compressor performance. This measurement is then compared with the results obtained with a semi-empirical model, which is able to predict, in part load, the compressor displacement. The model predicts the displacement ratio with deviations that vary between −14.5% and +8.1%.     

Performance analysis of a series of hermetic reciprocating compressors working with R290 (propane) and R407C

In this paper, a series of compressors with different capacities and geometries working with propane as refrigerant are analyzed in terms of the compressor model developed by [E. Navarro, E. Granryd, J.F. Urchueguía, J.M. Corberán, A phenomenological model for analyzing reciprocating compressors, International Journal of Refrigeration, in this issue, doi:10.1016/j.irefrig.2007.02.006]. The relative influence of the diverse compressor losses is estimated as a function of the operating conditions.In addition, a comparison study between propane and R407C was carried out for one compressor and the observed differences were analyzed in terms of the compressor model. This study was also useful to verify the model's goodness with the aim of predicting the compressor performance with an untested refrigerant.     

二氧化碳跨临界压缩机研究进展

介绍CO2制冷剂跨临界循环的优势，回顾CO2压缩机的发展历史，对已开发的各种类型的CO2压缩机进行分析，总结CO2压缩机发展的关键技术。     

小型制冷压缩机吸气的流固耦合分析和优化研究简

 为了优化压缩机的制冷量、功率、噪音和寿命,以研究无升程限制器的吸气阀运动规律为目标,确立数值模拟和物理试验相互佐证寻求最佳阀片结构的基本思路.将制冷剂的流动场和阀组构成的结构场耦合起来模拟阀片的运动,利用ADINA流固耦合模块(fluid-structure interaction,FSI),基于流体质量、动量、热量守恒定律和平板振动模型,得到了吸气过程中的阀片位移、缸内压力、吸气速度及阀片与阀座接触力的时程变化曲线.分析了阀片设计参数对其动态响应的影响,发现减小厚度可以优化压缩机性能,根据最大有效流通面积准则,得到了WS75YV型号压缩机的吸气阀最小即最优厚度.欧拉坐标系下制冷剂的速度分布及气缸内温度随时间的变化过程的模拟结果表明,压缩机吸气过程存在过热现象.采用第二制冷剂量热计法测量压缩机的制冷量、电机功率和其比值(coefficient of performance,COP),对比压缩机性能的理论和模拟计算值,证明流固耦合模拟方法可行,基于此对压缩机进行设计和优化是可靠的.     

采用R22的冷柜压缩机研究

本文介绍了采用R22为制冷剂的大规格冷柜压缩机的研究开发情况,并对两种规格的冷柜压缩机的性能和可靠性进行了实验研究,结果表明这两种新开发的采用R22的冷柜压缩机具有优良的性能,并能够长期安全可靠的运行.