热风阀阀板的节能探讨

我国国内的热风阀阀板同国外阀板相比,存在着热损失大的缺点,原因是耐火材料衬热阻较小。文中以有限元模拟技术为手段,以增大热阻为目的,进行了耐火材料组合衬设计。设计结果表明,组合衬的热损失可以降到单一衬的43％～56％左右,节能效果十分显著。     

核电主汽阀关闭流场的二维动态模拟

为了研究核电主汽阀关闭时流场的变化情况及阀板的受力情况,利用计算流体力学软件FLUENT对主汽阀二维简化模型的流场进行了稳态和不同关闭速度的动态数值模拟,得到了阀门的动态流场信息及阀板的受力分布曲线。通过分析可知,阀板两侧的压力差产生的摩擦力是决定阀门能否正常关闭的关键因素,关闭速度越快所受到的摩擦力越大。     

换流站阀控保护闭锁隐患分析及措施

在介绍上海南桥换流站阀控保护系统的结构与功能的基础上,解读了晶闸管电子设备、阀基电子设备和阀监控设备的作用与信息传输通道。通过深度排查隐患,梳理和分析了阀控保护的各种告警和闭锁信号,从中列出了导致直流逻辑闭锁的3条隐患。针对"ACTIVE"信号回路故障、MC板或DIO板故障、直流电源进线失电故障,制定了相应的整改措施,以确保直流输电系统安全稳定运行。     

某新型核电汽轮机再热阀卡涩问题的研究

核电汽轮机再热阀在机组运行过程中起着重要的作用。某新型再热阀在定期试验时发生卡涩问题,阀门无法关闭。分析了再热阀卡涩的原因,制定并实施了解决方案。实践表明,在运行工况下,核电汽轮机再热阀的机械密封无法完全隔离蒸汽,蒸汽泄漏是不可避免的;采用机械密封的再热阀,需要保守考虑轴承和润滑脂选型,解决蒸汽泄漏、阀轴窜动等问题。     

东方660 MW超超临界二次再热汽轮机超高压主汽阀阀杆动应力分析

汽轮机主汽阀需要很高的关闭速度,由此带来阀杆冲击动力学的强度问题。以前设计主要按照冲击动力学的理论,通过能量法求解系统动应力。文章介绍了阀杆动应力的理论计算方法,并分析了理论计算方法的合理性。随着计算机技术的发展,有限元方法求解阀杆动应力成为可能。文章详细介绍了阀杆动应力有限元计算参数的选取方法,并通过ABAQUS商用有限元软件计算了东方660 MW超超临界二次再热汽轮机超高压主汽阀阀杆动应力。对理论计算结果和有限元计算结果做了比较,分析了有限元计算结果的合理性。计算显示东方660 MW超超临界二次再热汽轮机超高压主汽阀阀杆峰值应力小于材料疲劳极限,阀杆具有永久寿命。     

某电厂高压主汽阀阀碟锈蚀分析

用物理、化学和能谱分析方法，对某电厂高压主汽阀阀碟及其套筒的锈蚀原因进行了研究和分析。结果表明，３０Ｃｒ１Ｍｏ１Ｖ钢和３０Ｃｒ２ＭｏＶ钢的抗氧化性能相当，电厂所用热蒸汽品质不符合标准。     

基于壅塞流的动力电池防爆阀泄压特性的动态仿真

防爆阀作为缓解电池系统热失控的被动安全措施,在电芯设计中扮演着非常重要的角色,防爆阀的开启压力、阀体面积及阀体位置对电芯热失控后的泄压过程有着重要影响。本工作主要介绍了动力电池热失控后产热产气导致防爆阀开启的泄压过程,通过理论计算、实验测试及仿真分析相结合的方式,对防爆阀的泄压特性进行了系统阐述与分析。首先,基于流体力学基本原理和方程从理论上对防爆阀的泄压过程进行了分析,阐述了电芯热失控过程中防爆阀开启后的泄压壅塞流基本状态;其次,通过开展无阀电芯的加热热失控和过充热失控两类实验,实验中实时监测了电芯热失控过程中卷芯的温度和电芯的内压,从而得到电芯热失控过程中防爆阀开启前电芯的产热产气速率;最后,对电芯的产热产气及泄压过程进行仿真,基于COMSOL软件,建立了动力电池防爆阀泄压过程的系统模型。且对防爆阀的开启压力、阀体面积及阀体位置等影响因素进行了归类仿真分析,并与实验数据进行了对比验证,得到了较为优化的防爆阀结构设计,为动力电池优化设计提供了一定的参考。     

改进型30万千瓦汽轮机主汽阀阀壳热应力的实测及分析

为了提高机组的使用寿命,国产30万千瓦汽轮机组自第13台起改用主汽阀启动,目的是为了降低高温部件的热应力,使得高温部件的寿命得到保证。本文详细地介绍了汽轮机主汽阀阀壳热应变的测试方法及高温电测技术。试验得到的主汽阀阀壳应力值将为计算和结构改型提供一定的依据。     

喷嘴阀箱气动性能计算与试验分析

通过对喷嘴阀箱气动性能的计算与试验分析,研究了阀箱内部结构变化对气动性能的影响。结果表明,合理地选择导流板的形状及其设置位置。能有效地提高阀箱的流动效率与通流能力。     

汽轮机CCI低压旁路阀内漏改善

为了提高汽轮机运行可靠性及经济性,笔者团队对汽轮机CCI低压旁路阀进行改造,彻底消除汽轮机低压旁路阀内漏,有效地避免阀后管道超温运行导致的金属蠕变速度加快,同时避免低压旁路阀泄漏的高温蒸汽对凝汽器的热冲击,消除对凝汽器内部构件的威胁,提高机组的真空度和经济性。     

电厂阀门内漏在线监测研究

减少阀门内漏量是电厂重要的节能减耗手段.对阀门内漏在线监测及其经济性分析研究,采用基于传热学原理的方法计算阀门内漏量,等效焓降法计算内漏量对于机组经济性影响.对某一电厂300 MW机组阀门的内漏量进行监测,结果表明:该系统能定量计算阀门内漏量和对电厂煤耗的影响,具有非接触、在线、实时测量等优势,可以为电厂运行人员提供阀门检修、检漏的依据和参考.     

基于整车经济性的两级可变气门升程技术研究

以整车NEDC循环为标准,对比NEDC循环中的工况点油耗量的权重,优化高油耗率工况点,能够更直接地降低整车循环油耗.本文基于NEDC循环中高油耗权重的发动机工况点,研究采用两段式可变气门升程技术对NEDC循环综合油耗的影响,并分析说明使用小升程气门曲线能够降低油耗率的原理.结果显示,此款发动机使用两段式可变气门升程能够有效降低NEDC循环油耗约2.5％.     

锅炉脱盐水系统变频节能改造

在化工生产中,离心泵使用较为普遍,其出口压力往往要高于生产系统所需压力,常见做法是采用阀门降压,能耗较高.相比而言,变频调速能够降低离心泵出口压力过高问题,且能够节省阀门降压带来的能量损耗.针对兖矿国宏公司脱盐水系统,收集离心泵出口管道阀门前后压力数据,进行相关计算后得出节能效果.结合现场情况和运行经验,编制变频改造方案.改造完成后,再次收集相关数据,经过比较节能效果明显,达到预期目的.     

Performance of thermostatic and electronic valves controlling the compressor capacity

The performance of the energy consumption of an electronic valve and a classical thermostatic valve has been compared when these expansion valves are adopted in a vapour compression plant subjected to a cold store. The main aim is to verify experimentally which type of expansion valve would be preferable from energy point of view when a classical thermostat or a fuzzy logic algorithm are used as the control system for the refrigeration capacity. The fuzzy logic‐based control is able to modulate continuously the compressor speed through an inverter. The results show that with a fuzzy algorithm, the thermostatic expansion valve allows an energy saving of about 8% in comparison with the electronic valve. When on–off control is used, the electric energy consumption obtained both with the electronic valve and with the thermostatic valve is comparable. Copyright © 2006 John Wiley & Sons, Ltd.     

包装企业节能措施探讨

在对包装企业中能耗较大的瓦楞纸板生产线进行简单介绍的基础上,通过实际调研,讨论和分析了纸箱生产过程中的两种节能方式:蒸汽和凝结水回收,预热器滚筒保温。进一步验证了蒸汽和凝结水回收节能量较大,预热器滚筒保温的节能能力虽然较小,但预热缸保温的投资小,回收成本较快。     

Numerical study on the behavior and design of a novel multistage hydrogen pressure-reducing valve

Applying hydrogen fuel-cell vehicles (HFCVs) is feasible to achieve net zero carbon emission in transportation sector. The energy density requirements of these vehicles are fulfilled via high-pressure gaseous hydrogen storage; therefore, an effective pressure-reducing system is necessary. In this work, a novel multistage pressure-reducing valve (named as T–M valve) combining a sleeve pressure structure valve and a Tesla-type orifice valve is proposed. A computational fluid dynamics (CFD) model is developed to analyze the influence of operating parameters on pressure and velocity distributions. Results show that the large pressure and velocity gradients’ region is concentrated on the throttling elements. The valve opening and pressure ratio significantly affect energy consumption. In addition, the Mach number in the valve less than one is proposed. This study is conducive to further energy conservation and emission reduction and the research of multistage flow pressure-reducing devices.     

Pressure analysis on two-step high pressure reducing system for hydrogen fuel cell electric vehicle

Hydrogen fuel cell electric vehicle (FCEV) can achieve zero exhaust emission and zero pollution. In order to make FCEV reach a farther travel distance, greater demands are put on its pressure reducing system. In this paper, a two-step high pressure reducing system for FCEV is proposed. The system is made up of two parts, a new high multi-stage pressure reducing valve (HMSPRV) and a multi-stage muffler. As a new system, its feasibility has to be verified. Since the valve opening condition has a great effect on hydrogen flow, pressure reduction and energy consumption, different valve opening conditions are taken as the research point. The flow field analysis of the new HMSPRV is conducted on three aspects: pressure field, velocity field and energy consumption. It can be found that both the pressure reducing and velocity increasing gradients mainly reflect at those throttling components for all valve openings. For energy consumption, in the comprehensive study of flow vortexes and turbulent dissipation rate, it can be found that the larger of the valve opening, the larger of energy consumption. Then, a thermo-fluid-solid coupling analysis is conducted on the new HMSPRV, and it is concluded that the new system meets strength requirement. Furthermore, as the second step of the high pressure reducing system, the flow and pressure fields of multi-stage muffler are investigated. The five-stage muffler is exactly designed to complete the whole pressure reducing process. This study can provide technological support for achieving pressure regulation in the hydrogen transport system of FCEV when facing complex conditions, and it can also benefit the further research work on energy saving and multi-stage flow of pressure reducing devices.     

Energy efficiency supervision strategy selection of Chinese large-scale public buildings

This paper discusses energy consumption, building development and building energy consumption in China, and points that energy efficiency management and maintenance of large-scale public buildings is the breakthrough point of building energy saving in China. Three obstacles are lack of basic statistics data, lack of service market for building energy saving, and lack of effective management measures account for the necessity of energy efficiency supervision for large-scale public buildings. And then the paper introduces the supervision aims, the supervision system and the five basic systems’ role in the supervision system, and analyzes the working mechanism of the five basic systems. The energy efficiency supervision system of large-scale public buildings takes energy consumption statistics as a data basis, Energy auditing as a technical support, energy consumption ration as a benchmark of energy saving and price increase beyond ration as a price lever, and energy efficiency public-noticing as an amplifier. The supervision system promotes energy efficiency operation and maintenance of large-scale public building, and drives a comprehensive building energy saving in China.     

Parametric analysis on multi-stage high pressure reducing valve for hydrogen decompression

Hydrogen fuel cell electric vehicle (FCEV) can reduce air pollution as well as achieve efficient use of hydrogen energy. Farther travel distance requires larger hydrogen storage pressure, thereby imposing more demanding working conditions on the pressure reducing system. In this paper, a multi-stage high pressure reducing valve (MSHPRV) for hydrogen decompression in FCEV is proposed, and the effects of different structural parameters on its internal flow characteristics are investigated to achieve a better hydrogen decompression process. Results show that compared with perforated plate, multi-stage perforated sleeves and valve core hold the dominant position in hydrogen throttling process. Larger multi-stage perforated sleeve diameter, perforated plate diameter and pressure ratio relate to larger hydrogen kinetic energy, turbulence vortex and energy consumption. However, with the increase of perforated plate stage and perforated plate radius, the turbulent intensity and energy consumption inside MSHPRV decreases correspondingly. This study can provide some technical supports for achieving hydrogen decompression in FCEV when facing harsh working conditions, or help with dealing energy conversion during decompression process.