主冷液氧中碳氢化合物含量控制的探讨

基于外压缩和内压缩流程空分设备主冷碳氢化合物爆炸的机理分析,提出采用常规分子筛吸附净化流程、全浸式主冷空分设备的主冷中碳氢化合物含量的控制措施。     

内压缩还是外压缩——关于如何选择大型空分设备流程的一些看法

介绍了采用内压缩流程技术的空分设备的特点 ,并从投资成本与运行费用两方面对内压缩流程与外压缩流程进行了比较 ,最后就冶金行业和化工行业选择哪一种流程的空分设备提出了建议。     

武钢60000m^3／h制氧机流程与主冷型式的选择

对目前空分设备流程、主冷型式的安全性与节能性进行了分析和综合比较，阐述了武钢60000m^3／h制氧机选择外压缩流程和降膜式主冷的依据，提出了空分设备流程和主冷型式的选择原则。     

150m~3/h空分设备内压缩流程改造的理论与实践

文章结合实际,从冷量消耗、冷平衡、单位能耗等方面入手,分析了150m3/h空分设备中压正流膨胀外压缩流程改为内压缩流程的可行性;并提出了内压缩流程今后的改进方向。此改造在哈尔滨汽轮机厂氧气分厂实施后,两年多的运行证明,空分设备运转状况良好,经济效益显著。图2表1。     

冷量与精馏的操作

全低压流程的空分装置,正常生产的必要条件是具有保持空气进行液化和精馏所需要的低温。在冷开车的过程中,要冷却设备、积累液体;在正常生产中,需要弥补冷量的损失。因此都需要大量的冷量,其来源一是空气等温压缩的节流效应制冷量,二是压缩空气等熵膨胀制冷量。耗冷为周围介质跑冷损失和换热设备复热不足冷损失。其冷量平衡方程式[1]是:     

内压缩空分流程探析

本文分析了内压缩空分流程中制冷系统、换热系统及精馏系统的特点;研讨了常用的空气循环和氮气循环内压缩空分流程组织中的主要问题;指出了这种流程组织的关键是合理地安排液体蒸发复热系统,充分利用设备的内部潜力。并对目前适用于大化肥工业的比较先进的大型内压缩空分流程,作了详细的分析。图3表2参5。     

武钢60000m~3/h制氧机流程与主冷型式的选择

对目前空分设备流程、主冷型式的安全性与节能性进行了分析和综合比较 ,阐述了武钢 6 0 0 0 0m3 /h制氧机选择外压缩流程和降膜式主冷的依据 ,提出了空分设备流程和主冷型式的选择原则。     

大型内压缩流程空分设备的安全探讨

结合大型内压缩流程空分设备的设计、安装和调试经验，从主换热器和主冷等4方面分析了内压缩流程空分设备的安全因素，从主换热器1％液氧的排放和临时停车的操作等7方面介绍了大型内压缩流程空分设备的安全措施。     

内压缩流程空分设备所需高压液空量的估算

根据热量平衡,利用线性回归方法,得出内压缩流程空分设备所需高压液空量与内压缩的液氧、液氮量以及各种低温液体产品量之间存在的线性关系式,分析了影响高压液空量的各种因素。     

大型内压缩流程空分设备的安全探讨

结合大型内压缩流程空分设备的设计、安装和调试经验,从主换热器和主冷等4方面分析了内压缩流程空分设备的安全因素,从主换热器1%液氧的排放和临时停车的操作等7方面介绍了大型内压缩流程空分设备的安全措施。     

基于高压级活塞排量的双级压缩制冷循环制冷量计算式

为了研究双级压缩制冷循环制冷量简化计算方法，分析了高低压级压缩机活塞排量比、容积效率及指示效率等参数对制冷量的影响，以活塞排量比与中间温度的关系式为基础，作一定的简化处理，理论推导出基于高压级活塞排量的双级压缩制冷循环制冷量简化计算式，并通过实例进行了验证。实例计算结果表明：根据简化计算式以及常规方法计算的结果误差较小，吻合度高，推出的双级压缩制冷循环制冷量计算式是准确的。     

对配组式双级压缩制冷系统热力循环的计算与分析

利用由多台螺杆压缩机组成的配组式双级压缩制冷系统，在高压级、低压级压缩机理论输气量之比不同的运行工况下，对其进行热力计算与分析，并对制冷量、轴功率、单位轴功率制冷量作综合的比较与分析。     

内压缩氮膨胀流程空分产品能耗分摊的探讨

针对液氧内压缩氮膨胀空分流程提出一种分设备求得各种产品分摊能耗的方法,比人为规定能耗分摊比例更为精确,比建立系统的精馏模型来计算空分能耗分摊的方法更为简单。为多种类(氧、氮、氩)、多压力等级(中、低压)、多状态(气、液)产品的内压缩氮膨胀流程的空分装置提出一种值得探讨的空分能耗分摊方法。     

蒸汽压缩/喷射制冷系统喷射器设计及节能分析

蒸汽压缩/喷射制冷系统是一种有效的节能系统,可以减少节流膨胀损失,降低压缩机压力比,提高制冷系统效率。选择5种计算工况对蒸汽压缩/喷射制冷系统进行计算,研究喷射器结构与蒸发温度和冷凝温度的变化规律,并与普通蒸汽压缩系统对比,从制冷量、压缩机耗功、性能系数三个角度分析新系统的节能效果。计算结果表明蒸汽压缩/喷射制冷系统在低温工况条件下节能效果最优,制冷量最大可提高29%,压缩机耗功最大可降低65%,COP值最大可提高63%。     

Characteristics of Voorhees refrigerating machine with hermetic piston compressor producing refrigeration at one or two temperature levels

Research on the operation of the refrigerating machine working on the Voorhees cycle which permits two-stage compression in a single-cylinder compressor has been carried out. The purpose of this research was to study the possibilities of using the Voorhees machine in a domestic refrigerator for production of refrigeration at one or two temperature levels. The experiments were carried out on the basis of a small hermetic lubricated compressor with a low refrigerating capacity operating on a commonly used R12 and natural refrigerant isobutane R600a. The improved refrigerating capacity in the Voorhees cycle with isobutane makes the latter an alternative substitute for conventional refrigerants. Some peculiarities in the operation of a hermetic piston compressor as part of the Voorhees refrigerating machine have been revealed. They require the use of a compressor developed specially for the Voorhees cycle. The method of optimizing the cycle parameters for a one temperature refrigerating system is suggested in this paper. The research carried out proved that the optimum intermediate pressures of the Voorhees refrigerating machine producing refrigeration either at one or two temperature levels are different.     

Modified Roebuck compression device for cryogenic refrigeration system of superconducting rotating machine

Cryogenic refrigeration system installed on superconducting rotor has the merit that it can eliminate cryogen transfer between rapidly revolving rotor and stationary part and, therefore, the loss generated by it. Nevertheless, such an on-board cryogenic refrigeration system has not been realized yet because of the absence of compression device that can work reliably on rapidly revolving rotor. This paper presents the idea of modified Roebuck compression device as a potential on-board compression device. Although it has the disadvantage that it requires large radial space and external cooling and heating, a modified Roebuck compression device of 14 stages with diameter of 0.80 m mounted on a rotor revolving at 3600 rpm can produce substantially high compression ratio. J-T neon refrigeration system equipped with such a compression device can produce low temperature of 30 K and be useful for cooling superconducting rotor windings made of high temperature superconductor.     

Alternative evaluation of liquid-to-suction heat exchange in the refrigeration cycle

This paper advances a thermodynamic study of the effects of the liquid-to-suction heat exchange in vapor compression refrigeration cycles. The analysis was carried out for refrigerants of current interest, such as R134a, R22, R290, R410A, R600a and R717 assuming the cooling capacity as a constraint so that the evaporating pressure is free to vary. It is shown that the coefficient of performance may either increase or decrease when an internal heat exchanger is introduced into the cycle, depending not only on the working pressures, the heat exchanger effectiveness, the specific heat ratio, and the available latent heat to produce additional refrigerating effect, but also on the change experienced by the evaporating pressure. The thermodynamic conditions required for performance improvement are also discussed.     

杭钢20000m~3/h内压缩流程空分设备操作探讨

从投资成本、运行费用、安全可靠性和操作简便性对内压缩流程和外压缩流程空分设备进行简单比较,探讨杭钢20000m3/h内压缩流程空分设备的常规操作和变负荷操作的体会。     

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.