蒸汽喷射器在节能应用中的性能分析

蒸汽喷射器是橡胶生成中一种有效的蒸汽回收节能装置。通过自主编程与商业流体软件Fluent结合的计算分析方法,探讨压力参数的变化对喷射器性能及内部流场的影响,讨论蒸汽喷射器性能变化对蒸汽回收节能应用的影响。结果发现,喷射器性能对压缩比的变化影响更敏感;当喷射器的压缩压力低于临界压力时,喷射器效率严重恶化。     

多级热压式回热抽真空系统在1000MW火电机组中的应用

针对单背压1 000 MW火电机组真空系统优化节能研究及应用,文章介绍了一种以蒸汽喷射器为核心部件的多级热压式回热抽真空系统。结合机组50%THA、75%THA、100%THA三个实际运行工况,对采用水环式真空泵和三级喷射器抽真空系统两种方式进行对比分析,得出三级喷射器抽真空系统节能效果、经济效益明显,投入产出比效果好。     

吸收-喷射复合制冷系统热力性能与节能分析

基于工业余热回收利用,提出了一种吸收-喷射复合制冷系统,对系统建立数学模型并进行热力性能分析,分析了发生温度、蒸发温度、冷凝温度、吸收温度及喷射器效率对系统COP的影响。与传统单效式吸收式制冷系统进行对比,得出了吸收-喷射复合制冷系统COP最大时喷射器压缩比最佳值随发生温度的变化规律。研究表明:吸收-喷射复合制冷系统传统单效吸收式制冷系统可利用更低品位的热源,在热源温度为75℃时仍能正常工作;高、低压喷射器压缩比最佳值随发生温度的升高而降低,并逐渐接近于1,且低压喷射器最佳压缩比总是高于高压喷射器的最佳压缩比,在较低热源温度工况下,吸收-喷射复合制冷系统相比传统单效吸收式制冷系统节能效果显著。     

利用水喷射技术防止水泵的汽蚀

汽蚀现象是水泵应用的重大障碍。文章分析了离心式水泵汽蚀的机理,指出了解决水泵汽蚀问题必须提高入泵液态水所对应的饱和压力,即增大液态水的能量状态。介绍了利用喷射增压原理,在水泵入口加装水—水喷射器来解决水泵汽蚀的实用技术。利用该技术设计的密闭式凝结水回收系统,既成功地解决了汽蚀问题,又取得了显著的经济效益和节能、节水效益。     

有机郎肯循环复合系统中喷射器能量分析

有机郎肯循环利用太阳能、地热能和余热驱动,是回收余热、实现能源可持续发展的一个很好途径。有机郎肯循环可与喷射制冷循环结合,可同时提供电能和冷量。喷射器内部流体的不可逆混合引起的能量损失,是该系统最大部分的能量损失。着眼喷射器内部流场分布和机理,分析工作参数和几何参数对其性能的影响,以优化喷射器设计,减小系统能量损失,提高带有喷射器的有机郎肯循环复合系统的效率和节能潜力。结果显示,提高引射压力和出口压力会导致喷射器内部更多能量损失,制约整体系统的性能;在给定工况下,可通过钝化喷嘴内壁面、喷嘴处于最佳位置使喷射器达到最大喷射系数、最优性能,和最小的能量损失。     

有机朗肯循环复合系统中喷射器能量分析

有机朗肯循环利用太阳能、地热能和余热驱动,是回收余热、实现能源可持续发展的一个很好途径。有机朗肯循环可与喷射制冷循环结合,可同时提供电能和冷量。喷射器内部流体的不可逆混合引起的能量损失,是该系统最大部分的能量损失。着眼喷射器内部流场分布和机理,分析工作参数和几何参数对其性能的影响,以优化喷射器设计,减小系统能量损失,提高带有喷射器的有机朗肯循环复合系统的效率和节能潜力。结果显示,提高引射压力和出口压力会导致喷射器内部更多能量损失,制约整体系统的性能;在给定工况下,可通过钝化喷嘴内壁面、喷嘴处于最佳位置使喷射器达到最大喷射系数、最优性能,和最小的能量损失。     

冷凝水回收装置

据不完全调查,北京市供热系统冷凝水回收率只有3.6%～19.3%,大量高品位的水被白白放掉。为此北京节能技术服务中心研制开发了 JLH 型冷凝水回收装置,近日通过市经委、市节能办主持验收。该冷凝水回收装置是用水——水喷射器前置于水泵入口,用喷射扬程代替与水泵入口水温相关的灌注压头,防止水泵工作时产生汽蚀,解决了水泵吸入口处汽堵的难题。该装置先后经同仁堂制药厂、西郊乳品厂     

再生水力喷射器的节能改造

水力喷射器作为一种介质输送设备广泛应用于生产的各个领域，专业厂家生产的定型喷射产品因适应性广，调节余地较大，有时工作效率较低，很难达到预期的经济效果，本文通过理论分析和科学计算，向读者介绍了一则水处理再生喷射器节能改造的成功经验。     

浅床流化床飞灰回燃系统中的可调喷射器特性研究

一、前言在用喷射器输送物料方面，已经进行了不少工作［1］［2］［3］。［3］研究了在沸腾炉粉煤底饲系统中用喷射器输送煤粉，喷射器的输送能力仅靠改变喷咀入口处的压力来调节。为能采用其它方式调节喷射器的输送能力，我们研究了可调喷射器，建立了浅床流化床飞灰分离国燃系统实验台，利用它来输送回收的飞灰，通过试验获得了喷射器的可调间距、开度与喷射能力相应关系的规律。二、飞灰回燃系统图1为试验装置的原则性系统图。物料经给料装置进人喷射器中与来自输送风机的空气混合后经底饲喷咀进入旋风分离器进行气团分离，物料回收。图1…     

匹配式多级喷射器的特性与环保节能应用

匹配式多级喷射器的研制，进一步拓宽了嘞射器的应用领域，本文介绍了它独特的优良性能，并利用它成功地回收了油田的原油挥发气，人有重要的能与环保价值。     

三喷头蒸汽水下喷注噪声试验研究

蒸汽在过冷水下喷注过程中,由于汽泡溃灭及喷注射流扰动会产生强烈的噪声.通过试验研究了不同结构的三喷头蒸汽水下喷注在不同的水温及蒸汽流量下的噪声规律.试验结果表明:三喷头喷注A声压级噪声主要受水温、蒸汽流量及喷头结构的影响,其中水温对喷注噪声的影响最大;喷注噪声随着蒸汽流量的增加而增大;在试验范围内,减小喷头的孔径或相对孔间距,可以减小喷注噪声.     

喷嘴可调式蒸汽喷射器的性能计算

基于气体动力学函数法,建立了的喷嘴可调式蒸汽喷射器的变工况性能计算模型。应用该模型得到了喷射器压缩蒸汽压力变化时,不同喷嘴喉口面积下喷射器性能的变化规律,为研究喷嘴可调式喷射器的变工况性能提供依据。结果表明:减小喷嘴喉口面积,喷射器的最佳工作点具有较高的喷射系数,同时该点的压缩蒸汽压力、压缩蒸汽温度较低;喷射器压缩蒸汽流量随喷嘴喉口面积减小而降低。     

一种太阳能吸热器过热蒸汽温度控制系统

介绍了一种应用于塔式太阳能热发电系统的水/蒸汽吸热器过热蒸汽温度控制系统。受到太阳辐射能间歇性和不确定性的影响,吸热器产生的过热蒸汽温度难于控制。控制系统根据吸热器在蒸汽流量变化、光功率变化和减温水流量变化等3种主要扰动下的过热汽温度动态响应特性,以减温水流量作为控制量,光功率和蒸汽负荷作为前馈信号,设计和研制了两段式过热蒸汽温度控制系统,使吸热器过热区出口汽温维持在允许的范围内。     

环周进水汽_液两相喷射性能优化

基于环周进水型汽-液两相喷射器流动机理的分析,研究并发展了一种新的喷射器优化的方法。采用在圆柱段混合室壁面上增加侧向孔的方式,使外界环境的低温水通过侧向孔进入混合室,形成二级引射,从而提高喷射系数。设计了以湿蒸汽为工作蒸汽的实验台和多喷嘴喷射器作为实验元件,湿蒸汽的压力在0.15～0.4 MPa范围内,湿蒸汽干度在0.25～1范围内,实验比较了优化前、后试件的性能,结果表明:在相同的蒸汽干度下,喷射系统实现了阶跃性的增长,且随蒸汽干度的增大,喷射系数提高的幅度增加,验证了采用该优化方法提高喷射性能是可行的。     

Solar driven steam jet ejector chiller

This paper presents a solar driven process to generate cold water for air-conditioning by parabolic trough collectors and a steam jet ejector chiller. The only working fluid in the system is water, which is used as refrigerant and working fluid. The operational behaviour of such a system has been investigated by a small test rig. The investigation shows that the cooling water temperature as well as the cold water temperature has a strong influence on the coefficient of performance of a steam jet ejector chiller. The coefficient of performance reaches high values in part load and at good re-cooling conditions, so that the mean efficiency is clearly higher than the nominal efficiency of the system. A first calculation of profitability leads to specific cold cost of 0.62 €/kWh in Germany and 0.15 €/kWh in Egypt.     

射油器数学模型的建立及仿真

建立了射油器的数学模型,对600MW机组射油器进行了仿真研究,为汽轮机润滑油系统的仿真及故障诊断建立了基础。     

Pre-adsorption of low-grade waste steam for high-temperature steam generation by using composite zeolite and long-term heat storage salt of MgSO4

Adsorptive heat transformer is a promising technology for waster heat recovery and global energy conservation. A novel cyclic adsorption heating system based on direct contact heat exchange method has been established for the purpose of high-temperature steam generation from hot water. Pre-adsorption is originally proposed before generation phase to enhance the system performance with composite zeolite 13X and MgSO₄ in the open-loop adsorption heating system. Composite zeolite is prepared by impregnation method. Experimental results show steam with temperature higher than 200°C is generated from inlet water at 72.0°C. During regeneration phase, dry air at 130°C and relative humidity of 7.37% is employed. Gross temperature lift is 95.0°C to 103°C for different pre-adsorption conditions. The effective steam generation time with pre-adsorption temperature at 90.0°C is prolonged by 27.4%. Meanwhile, the mass of steam is elevated by 16.2% compared with the cycle without pre-adsorption. Exergy coefficient of performance is upgraded by 14.7% and specific heating power for steam generation is increased by 16.0%. The pre-adsorption operation achieved the goal of recovery of low-grade waste steam on adsorbents to enhance the subsequent high-temperature steam generation. After pre-adsorption operation, the packed bed reaches adsorption and thermal equilibrium more quickly during generation phase. Thus, dynamic steam generation is significantly intensified and then system performance is improved correspondingly.     

An experimental investigation of steam ejector refrigeration system powered by extra low temperature heat source

A steam ejector refrigeration system is a low capital cost solution for utilizing industrial waste heat or solar energy. When the heat source temperature is lower than 80 °C, the utilization of the thermal energy from such a low-temperature heat source can be a considerable challenge. In this investigation, an experimental prototype for the steam ejector refrigeration system was designed and manufactured, which can operate using extra low-temperature heat source below 80 °C. The effects of the operation temperature, the nozzle exit position (NXP) and the diameter of the constant area section on the working performance of the steam ejector were investigated at generating temperatures ranging from 40 °C to 70 °C. Three ejectors with a same de Laval nozzle for the primary nozzle and three different constant-area sections were designed and fabricated. The experimental results show that a steam ejector can function for a certain configuration size of the steam ejector with a generating temperature ranging from 40 °C to 70 °C and an evaporating temperature of 10 °C. For a given NXP, the system COP and cooling capacity of the steam ejector decreased until inoperative as the diameter of the constant area section reduced. The results of this investigation provided a good solution for the refrigeration application of the steam ejector refrigeration system powered by an extra low-temperature heat source.     

应用于PRSTIG循环化SIA_02燃气轮机组上的喷射器

喷射器是ＰＲＳＴＩＧ循环系统的重要组成部分。本文针对ＳＩＡ－０２小燃气轮机组设计了喷射器,并进行了分析。     

Effects of particle sizes on performances of the multi-zone steam generator using waste heat in a bio-oil steam reforming hydrogen production system

Hydrogen production by bio-oil steam reforming is an advanced production technology. It is a good method of coupling waste heat utilization with bio-oil steam reforming to produce hydrogen, which increases the cleaning ability of the bio-oil steam reforming system. A multi-zone steam generator using waste heat has been proposed, which can produce the heat source and steam source of the hydrogen system. The DEM model of the multi-zone steam generator was set up. The model has been used to investigate the effects of particle sizes (40 mm–80 mm). With increasing particle size, the flow index and the flow uniformity gradually decrease, the vertical velocity gradient increases in the area on both side with the zone steam generator, and the vertical velocity fluctuation amplitude gradually increases. So, the hydrogen production decreases from the particle size increasing.