离心流化床干燥器中传热传质的实验研究

在不同操作条件下对离心流化床干燥器中湿物料的干燥过程进行了间歇实验研究，测定了气流入口、出口和床层温度以及物料湿含量时间的变化，分析了表观气速、颗粒直径、床层厚度、床体转速和物料初始湿含量对干燥过程的影响，获得了离心流化床干燥过程中传热和传质准则方程。     

旋叶式压缩机的滑片顶部形状研究

通过建立旋叶式压缩机中滑片顶部与气缸壁接触点的运动关系式,得到了滑片顶部形状对接触点运动的影响规律,并由此分析了滑片顶部圆弧的形状对润滑及磨损的影响.理论计算及分析表明:存在滑片顶部圆弧的半径RV及圆心偏离滑片中心线的距离Rd的最佳值,使得滑片与气缸壁间能够形成良好的润滑条件,且接触点在整个滑片顶部圆弧范围内移动,不出现"尖点滑移"的现象.RV、Rd依气缸壁型线、滑片厚度、滑片倾斜角的不同而异.依据上述理论,对某工业用压缩机的滑片顶部形状进行了优化.试验研究表明,经800h运转后的滑片形状与优化的顶部圆弧形状相近,从而验证了本文理论分析的合理性.     

喷水涡旋空气压缩机工作特性的研究

从变质量系统热力学原理出发,考虑喷水涡旋空气压缩机的换热及工作特点,建立了其热力学模型.通过对喷水涡旋压缩机工作过程的模拟,分析了转速、喷水量、功率、排气温度等参数之间的关系.模拟计算及实验结果表明:当喷水量为60kg/h,排气压力为0 2MPa时,涡旋压缩机的实际功率接近于等温功率,并且随着转速的提高逐渐偏离等温功率;容积效率随着转速的提高而增大,在转速小于3000r/min的范围内,转速对涡旋压缩机的容积效率影响较大;排气温度随着喷水量的增大而降低,与绝热过程相比,在压比为2 0时,排气温度的降低大于40K;喷水引起的额外耗功比压缩机的指示功率小3%.     

离心式固液两相流泵叶片边界层动量积分

离心式固液两相流泵叶片的边界层的理论分析，可以为分析流体在叶片表面沿程阻力提供基础，进一步也可以为确定叶片型线提供理论依据。建立了离心式固液两相流泵叶片边界层方程，为求解含有固体扰动项的粘性流体的边界层方程，引入了固相扰动因子和边界层厚度系数，它是进一步分析固液两相流泵叶片边界层及叶片解析设计的基础，同时也降低了由于边界条件的构造和构造含有扰动项的动量积分方程及其求解的难度。     

一种新型大容积低温箱的研制

介绍了一种新型大容积低温箱的研制情况．该低温箱采用了由两个单级压缩系统组成的复叠式制冷系统，其中高温循环系统采用R22作为制冷剂，低温循环系统采用R13作为制冷剂．R笠系统既可以单独运行，又可以与R13系统复叠运行，因此系统可以达到-70℃和-20℃两个蒸发温度．同时，低温箱内工作室净容积达到0．216m^3，在-70℃的低温下，低温箱制冷系统仍能稳定运行．     

CP型单螺杆压缩机的计算机辅助设计

基于CP型单螺杆压缩机工作原理和主要零部件设计计算方法，利用三维建模、工程数据库、三维动画和可视界面等先进技术，完成了集实体建模、参数化设计和绘图、动画演示等功能于一体的计算机辅助设计系统。     

特种车辆涡轮增压器内部流动特性分析

涡轮增压器是特种动力装备的重要动力部件,良好的密封是保证涡轮增压器正常工作的关键因素,而叶轮高速运转引发的压力不均则是泄漏的重要原因.基于流体力学分析方法建立有限元模型,研究了一种离心泵式密封结构的内部流场分析及流动特性,探讨了压气机端泄漏量、内部压力在不同转速和窄隙出口负压等工况下的变化规律,验证了该密封结构的油气密封性能.结果表明,受高速离心效应影响,该密封结构具备良好的防止压气机端漏油效果,高速运转时会产生漏气.研究结果为改进涡流增压器密封结构提供了参考依据.     

Numerical Study on Entropy Generation of the Multi-Stage Centrifugal Pump

The energy loss of the multi-stage centrifugal pump was investigated by numerical analysis using the entropy generation method with the RNG k-ε turbulence model. Entropy generation due to time-averaged motion and velocity fluctuation was mainly considered. It was found that the entropy generation of guide vanes and impellers account for 71.2% and 23.3% of the total entropy generation under the designed flow condition. The guide vanes are the main hydraulic loss domains and their entropy generation is about 9 W/K, followed by impellers. There are vortices at the tongue of the guide vane inlet as well as flow separations in the impellers, which lead to entropy generation. The fluid impacts the outer surface of the guide vanes, resulting in the increase in entropy generation. There are refluxes near the guide vane tongues which also increase the entropy generation of this part. The entropy generation distribution of the guide vanes and impellers was investigated, which found that the positive guide vane has more entropy generation compared with the reverse guide. The entropy generation of the blade suction surface is higher compared with the pressure surface. This study indicated that the entropy generation method has distinct advantages in the assessment of hydraulic loss.     

Energy Analysis of Precooling Air Compressor System

Energy saving is one of the main technique routes for net zero carbon emissions. Air compressor systems take up a large part of energy consumption in the industrial field. A pre-cooling air compressor system was proposed for energy saving by cooling the air before it flows in a compressor. The energy efficiency of the proposed system was analyzed. As additional energy consumption is required for air cooling, the feasibility of the pre-cooling method for energy saving was analyzed. As the efficiency of the pre-cooling air compressor system is mainly influenced by the environment temperature and humidity, applicability of the system in different regions and at different seasons was discussed. A pilot project was performed to verify the technical feasibility and economics of the proposed system. When the precooling temperature of the pilot system was set to 2 °C, the annual pneumatic-electrical ratio of the system can be increased by approximately 2% in several regions of China. This paper shows the pre-cooling air compressor system is feasible for energy saving.     

CAES离心压缩机可调扩压器调节规律研究

离心压缩机是压缩空气储能系统中关键设备之一,需具备在较宽流量、压力范围内高负荷高效率运行的能力。作为一种变工况调节技术,可调扩压器可以扩大压缩机工作流量范围,改善气动性能。因此,本文以某压缩空气储能系统用离心压缩机为研究对象,通过数值计算方法研究了可调扩压器调节时压缩机性能变化规律。结果表明采用可调扩压器可以有效拓宽压缩机运行特性,工作流量范围扩大44%,压比范围扩大25%.此后,本文采用Kriging模型获得了压缩机综合性能曲线图和不同储能工况需求下扩压器的调节方案及规律,为压缩空气储能系统离心压缩机变工况主动控制提供了依据。