滑片式压缩机功率计算模型的研究

滑片式压缩机工作过程中,由于载荷的连续变化及受力情况复杂,目前尚没有一种比较准确、简便的计算方法,本文在对压缩机工作过程中受力分析的基础上,将功率计算分成两部分,即气体压缩功和机械功,并提供了一种新的计算模型。大量实验数据验证了该模型的正确性。     

轴向滑片式压缩机工作容积计算

根据轴向滑片式压缩机的结构特点,在满足其动力性能的前提下,从拥有最大工作容积空间的要求出发,提出压缩机转子端面型线按正弦曲线设计的工作客积计算公式。     

迷宫式压缩机的泄漏特性分析

通过建立迷宫密封的数学模型,提出了一种简化分析的迷宫密封泄漏量计算方法;联立迷宫式压缩机工作过程的数学模型,数值求解预报了迷宫式压缩机的泄漏特性;数值程序应用Visual C＋＋．NET编写,界面直观,通用,计算结果与试验结果的吻合验证了模型和程序的正确性;应用该数值方法着重分析了排气压力,转速等设计参数对迷宫式压缩机泄漏特性的影响,结果表明．增大排气压力会增大迷宫式压缩机的泄漏,而转速的提高可有效降低泄漏,这些结论为迷宫式压缩机的国产化设计和性能优化提供了依据。     

双滑片椭圆转子压缩机径向间隙泄漏研究

建立了双滑片椭圆转子压缩机的径向间隙泄漏模型,对不同径向间隙的泄漏量进行了计算和分析,并和相同规格的滚动转子压缩机进行比较。结果表明:椭圆转子压缩机的径向间隙泄漏量在相同条件下大于滚动转子压缩机,两者的差值随着间隙的增大而增大,在间隙为80μm时,椭圆转子压缩机的径向间隙泄漏量最多可比滚动转子压缩机大2.352 g/s;压比对泄漏量的影响较大,在压比一定时,转速和转子椭圆面短轴和长轴之比对泄漏的影响并不明显。严格控制的径向间隙是提高椭圆转子压缩机容积效率的主要因素。     

滑片式汽车空调压缩机可变排量减摩技术的研究

针对目前滑片式汽车空调压缩机存在较大摩擦与磨损的缺陷.提出一种能实现可变排量的滑片式汽车空调压缩机减摩技术.该技术可根据压缩机的实际工况,通过控制参与工作的滑片的数量,改变压缩机的实际工作基元数目而实现压缩机的可变排量输出,且可以减少接触缸孔壁面的滑片数量而有效降低它们之间的摩擦与磨损,最终达到提高压缩机机械效率和使用寿命的目的.介绍了该技术方案的工作原理,分析并讨论了该技术的结构设计要点.     

螺杆压缩机机械密封泄漏原因分析及改造

针对乙烯加氢尾气回收装置中喷液式螺杆压缩机存在的机械密封泄漏问题,进行密封性能参数分析,找出了机械密封泄漏的原因.采用弹簧静止式机械密封替换原弹簧旋转式机械密封后,延长了螺杆压缩机的安全稳定运行周期,明显改善了该机组的机械密封性能,节省了大量的润滑油.     

滑片压缩机内部工质动态泄漏特性的数值模拟分析

以汽车空调压缩机的主流机型——双工作腔滑片压缩机为研究对象,基于热力学以及流体力学计算原理,应用MATLAB数值分析软件对压缩机内部工质的动态泄漏特性进行了模拟分析,得到压缩机正常工作时内部泄漏量的变化规律:随着转速的提高泄漏量随之减小;随着滑片数的减少泄漏量随之增多;气缸型线相对升程的增加会使泄漏量增加;滑片相对长度越长泄漏量越大。     

双作用滑片式压缩机型线的分析与比较

对几种滑片压缩机的型线方程进行了分析和计算,求出不同型线形成的工作容积并进行了探讨。提出一种新型的气缸曲线,计算证明在不改变压缩机原有结构尺寸的前提下就能够扩大理论排量。在相同体积的条件下,压缩机的排量可增加20%以上,这样完全可以满足因新型制冷剂更替而需要扩大理论排量的要求。     

喷油单螺杆压缩机的泄漏分析与计算

在分析单螺杆压缩机泄漏通道中流动的基础上,提出了各通道泄漏类型的判定依据,建立了相应的泄漏模型,并导出了油、气泄漏量的计算公式,最后通过实验数据进行了验证。     

双层滑片压缩机两滑片厚度比的选择分析

介绍了作者研制出的双层滑片压缩机，这种压缩机的每个滑片槽内都安放两块重叠而又可以相对自由滑动的滑片，在改善端部密封的同时又减轻了滑片摩擦和磨损，使机器的工作寿命及机械效率得到提高。在建立双层滑片压缩机力学模型的基础上，对常见厚度比的双层滑片压缩机进行全面分析比较，找出双层滑片压缩机两滑片适宜的厚度比。     

Study of leakage and friction of flexible seals for steady motion via a numerical approximation method

A numerical model has been developed to solve the steady-state, smooth-surface elastohydrodynamic problem of flexible (polymeric or elastomeric) seals of nominally rectangular or toroidal shape, most commonly found in linear and rotary hydraulic actuators for reciprocating motion. The seals can be fluid-pressurized or even act as wipers. The model offers the advantage of stable and very fast, approximate numerical solution of the EHL sealing problem, which has not been given much attention in the literature in the last 40 years. This model by-passes common obstacles in elastohydrodynamics of soft contacts. It uses an approach similar to that at the beginning of the Inverse Hydrodynamic theory but then deviates from it, avoiding the tricky part of solving a cubic equation. It is relatively easy to program and requires no more than a few hundredths of a second of processing time of a modern personal computer for a complete solution and performance analysis, which is a leap forward compared with previous studies in the literature that required hundreds of iterations and finite element analysis to achieve similar results. In this study and for demonstration purposes, it is applied for a wide range of operating conditions, namely operating temperature between −54 and +99 °C, average contact pressure between 5 and 180 MPa and sliding speed between 0.6 and 38 mm/s (although these limits can safely be exceeded with the model). Results are presented for the contact pressure and film thickness distribution, seal leakage and hydrodynamic friction force. A study on the effects of the seal initial interference, sliding speed, seal geometry, and fluid starvation on lubrication and sealing performance have been derived for the previously mentioned range of operating conditions and for initially conformal and non-conformal sealing contacts, with the seals both stationary and non-stationary. The results are in agreement with those of several well-known theoretical and experimental studies in this field. The present study is for steady-state conditions and will be extended to a transient elastohydrodynamic analysis in another study.     

往复式压缩机故障诊断方法研究综述

本文叙述了往复式压缩机故障诊断的意义及研究现状,对往复式压缩机常见故障及机理进行了分析,并介绍了国内外一些常见的往复式压缩机状态监测与故障诊断的方法及其原理和特点,最后提出了往复式压缩机的故障诊断方法的难点和发展方向,为从事该方面研究提供借鉴.     

盘缘篦齿封严特性的数值模拟

为了解航空发动机空气系统中盘缘篦齿的流动及封严情况,采用数值模拟方法对二维盘缘篦齿封严特性进行了系统的研究。使用商业软件FLUENT 6.3对不同的盘缘篦齿齿数N、轴向间隙s和径向间隙d分别进行了计算,得出了在各种情况下泄漏系数随转速的变化关系,主要结论为:转速对篦齿封严的影响不明显;两个齿的封严效果比单个齿的好;相同的径向间隙d下,轴向间隙s越大,封严效果越好;相同的轴向间隙s下,径向间隙d越小,封严效果越好。     

An alternative mathematical model of vane anemometers based on the balance of power

Anemometers based on the exchange of momentum between the flow and rotating measuring element comprise an important class of instruments used in flow metrology, especially in meteorological and ventilation measurements. In these instruments, overvaluation of the measured average velocity, caused by the inertia of their rotors, takes place. To analyse this phenomenon and the dynamics of the measurement process, as well as to estimate and minimize the measurement uncertainty, it is required to be acquainted with the mathematical model of the anemometer. In this study, the model of the vane anemometer based on the equation of motion of its rotor available in the literature is analysed, and a new model based on the power balance is proposed. Model testing and a comparison of both models has also been performed.     

The Lubrication characteristics of the vane tip under pressure boundary condition of oil hydraulic vane pump

The Lubrication Mode of line contacts between the vane and the camring in an oil hydraulic vane pump has been investigated. First, the variations of the radial force of a vane were calculated from previous measurements of dynamic internal pressure in four chambers surrounding a vane. Next, the lubrication modes were distinguished with Hooke’s chart, which is an improvement over Johnson’s chart. Finally, the influence of the boundary conditions in the lubrication region on the fluid film lubrication was examined by calculating the film pressure distributions. The results showed that the lubrication mode of the vane tip exists in the rigidvariable-viscosity region, and that discharge pressure higher than 7 MPa greatly affects the oil film pressure in the small and the large arc section because of the Piezo-viscous effect.     

滚动转子式压缩机的间隙泄漏模型

根据滚动转子式压缩机内制冷剂间隙泄漏的特点，利用润滑油流动模型来模拟计算制冷剂的泄漏量。计算表明，通过径向间隙的泄漏量最大，其次是通向吸气腔的轴向端面间隙的泄漏量。因此合理地设计泄漏间隙值，可以有效地降低滚动转子式压缩机的泄漏损失。     

The effects of thermoelastic and wear on the leakage of compressible gases in shaft seals

Analysis are presented for a compressible gas flow across shaft seals. The leakage flow rate is developed analytically for a sealing gap due to eccentricity, misalignment of a shaft, sinusoidal wavy surfaces for both bodies, thermoelastic deformation on the edge of the body, and wear on the mating surfaces. A pressure distribution is determined as a power series based on the simplified nonlinear Reynolds equation. The restriction to exclude the thermoelastic effects was presented. Analytical results indicate that the thermoelastic distortion may dominate the seal performance when the eccentricity is large and width of the seal small at high speeds.     

基于Solidworks的叶片参数化设计系统开发

对利用VB、Micmsoft Access进行基于Solidworks的应用程序二次开发进行了研究,提出了基于Solidworks的叶片参数化设计系统开发的总体框架和实现方法,实现了叶片的参数化建模,缩短了叶片的设计开发周期,提高了设计效率和质量。文中给出了系统的体系结构和部分实现代码。本文提出的方法对开发复杂产品的参数化设计系统具有参考价值。     

汽轮机侧齿汽封与梳齿汽封流动特性研究

对汽轮机上侧齿汽封和梳齿汽封进行建模,基于数值求解方法,用有限体积法对控制方程进行离散,并求解湍流模型的封闭方程组,在不同的进口压力下,分析了侧齿汽封和梳齿汽封的三维流动特性。分析结果表明侧齿汽封并不一定优于梳齿汽封,对于高低齿形式的汽封,梳齿汽封的密封性能较好,泄漏量较少,对于平齿形式的汽封,侧齿汽封的密封性能较好,泄漏量较少,转子的凸台对汽封泄漏量的影响很大。为汽封齿的设计加工提供了理论依据,为汽轮机的汽封改造提供了技术参考。