Theoretical study on an innovative ejector enhanced Joule‐Thomson cycle

This paper describes an innovative ejector enhanced Joule‐Thomson cycle for low‐temperature refrigerators. Since an ejector is introduced into the cycle, the cycle performance is profoundly affected by the pressure lift ratio and entrainment ratio of the ejector. As a case study, the performance characteristic of the novel cycle refrigerator using the non‐azeotropic refrigerant mixture R14/R23 with the molar fraction of 0.6/0.4 is theoretically investigated in detail. The theoretical results show that in a typical refrigeration temperature range from −65°C to −95°C, the novel cycle refrigerator has 24.4%–41.5% improvement in coefficient of performance and 60%–220% enhancement in refrigeration capacity when compared to a basic Joule‐Thomson cycle low‐temperature refrigerator. This achieves a significant advantage as the use of the novel cycle is applied to low‐temperature refrigerators for the medical and commercial applications. Copyright © 2009 John Wiley & Sons, Ltd.     

Experimental evaluation of an ejector as liquid re-circulator in a falling-film water chiller

To experimentally evaluate the performance of an ejector working as a liquid re-circulator in a horizontal-tube falling-film evaporator with R134a, experimental tests are performed using a horizontal-tube falling-film water chiller prototype. Experimental observations on intertube liquid flow pattern of tube bundle validate the feasibility of the liquid re-circulation system using a liquid–liquid ejector. The analysis results show that the influence of the motive flow rate on the entrainment ratio of the ejector is small, and the average entrainment ratio of the ejector is about 2.03. With the increase of the valve opening of the regulating valve, the evaporating capacity of the falling-film water chiller rises 4.8%, from 940.2 kW with the re-circulation ratio of one, to 985.5 kW with the re-circulation ratio of 1.135. The COP of the falling-film water chiller reaches a maximum and then drops down with the increase of the re-circulation ratio, and the optimal re-circulation ratio is 1.135.     

注射模斜顶内顶杆保护装置设计

介绍了一种从斜顶内顶杆顶出，防止产品拉伤、位移的基本结构。它广泛应用在汽车内外饰件成型模具上。从斜顶内顶杆保护装置的基本结构、动作过程、设计要点等方面进行了阐述。     

国产50 MW机组轴抽系统的试验及改造

其公司2台50 MW机组投产以来,轴抽风机磨损增加,备品备件消耗量大,并且风机噪声很大,对设备运行和检修维护都带来一定的影响,经过试验提出了改造方案,并在机组小修中实施,改造后效果良好,节能效果显著,问题得到了解决。     

一种深小孔加工工艺的研究

针对一副注射模动模镶件顶针孔的结构特点，首先对其进行工艺分析，然后从工件装夹、刀具选择、切削用量选择及数控编程与加工等方面优化工艺方案，利用普通麻花钻和铰刀对其进行加工，最终达到了零件的技术要求。丈中结论为深孔切削加工提供了有价值的参考。     

长抽芯注射模结构的改进

对长抽芯注射模进行了结构改进,改进后模具结构简单,装配容易,制造成本低,塑件脱模实现自动化控制,生产效率高,塑件精度高,完全能够满足企业生产的需要,有较大的推广价值。     

中山市某医院基坑工程实例

通过介绍中山市某医院基坑工程,阐述了复合型喷锚支护结构在基坑中的应用,旨在通过该实例验证复合型喷锚支护结构在该地区的可行性,实践证明该支护结构值得推广应用。     

乙二醇蒸气喷射泵在聚酯装置中的应用

乙二醇蒸气喷射泵是聚酯装置中真空系统的重要设备。简要介绍了喷射泵在聚酯装置中的作用,提出了喷射泵的布置及配管要求,阐述了喷射泵支架所用弹簧的选择原则。     

磷酸二铵装置供热系统气体喷射器的技术改造

针对气体喷射器壳体容易被烧坏、抽吸能力小、卷吸率低等问题,采用改变壳体材质、扩大气体喷射器混合管直径、改变喷嘴位置等方法进行改造。改造后气体喷射器运行效果很好,使用寿命由4月延长至3年以上。     

低温多效压汽蒸馏海水淡化系统热力分析

低温多效压汽蒸馏(LT-METVC)海水淡化是一种很有发展前途的海水淡化方法,文中首先探讨了海水淡化系统中盐水焓、熵、的计算方法,然后对典型LT-METVC流程进行了详细的热力学分析,包括重要参数对系统性能的影响规律和系统的利用。结果表明:驱动蒸汽压力升高,会使造水比增加、效率下降,比传热面积则基本不变;系统效数增加或压缩比降低,都会使系统造水比和效率提高、比传热面积增大。LT-METVC系统的效率很低,在示例中仅为1.3%。提出并初步讨论了进一步改善性能的途径。