The Experimental Investigation of Recirculation of Air-Cooled System for a Large Power Plant

The paper introduces thermal buoyancy effects to experimental investigation of wind tunnel simulation on direct air-cooled condenser for a large power plant. In order to get thermal flow field of air-cooled tower, PIV experiments are carried out and recirculation ratio of each condition is calculated. Results show that the thermal flow field of the cooling tower has great influence on the recirculation under the cooling tower. Ameliorating the thermal flow field of the cooling tower can reduce the recirculation under the cooling tower and improve the efficiency of air-cooled condenser also.

Air Compressor Control System for Energy Saving in Locomotive Service Plant

The actuality and disadvantages of traditional high power asynchronism motor drive air compressor in locomotive ser-vice plant are discussed. In order to reduce the energy consumption and obtain safe running, a variable frequency con-trol method to the motor is supplied. A PLC with touch screen is used for monitoring the status of the compressor and its control system. It also presents energy consumption analysis caused by the variable frequency control method in a locomotive service plant.

Forced Compressed Air Cooling System for a 300 MW Steam Turbine in Waigaoqiao Power Plant

The 300 MW steam turbine installed in Waigaoqiao Power Plant with combined HPIP cylinders of double casing structure is a product of the Shanghai Turbine Works utilizing licensed technology. It has a large heat storage capacity and good thermal insulation, so the metal temperature of first stage of HP cylinder (FSMTI) may reach 400-450℃ after shut down and it takes 7-8 days to cool to 150℃ by natural cooling, Now with a forced cooling system the cooling time may be reduced to 40 hours, so that the turbine may be opened for repair work in about 5-6 days. The cooling system for #2 unit and test procedure are briefly described below.

风冷式干除渣系统在1×330 MW机组中的应用与优化改造

东海热电330 MW机组采用传统的水力除渣方式,存在水资源浪费、能耗高、安全性差、维护费用高等问题。对电厂生产过程中炉渣的排放方式及提高炉渣的综合率方面进行研究论证,将水力除渣系统改造成风冷式干除渣系统,改造后简化了排渣系统,提高了能源利用率及锅炉的效率。风冷式干除渣系统灰渣燃烧充分、含碳量低,保留了炉渣的活性,利于灰渣综合的利用,提高了社会效益及经济效益,对提高整个电厂的经济运行水平具有非常重要的意义。

空分压缩机厂房噪音治理防范策略

随着化工生产技术的不断进步,化工厂空分装置的噪声问题也越来越引发公众的关注和企业的重视。为此,文章通过对空分装置噪声特性的分析,明确了空分装置在运转过程中产生噪声的危害影响因素,提出了空分装置噪声控制防范及治理措施。

空压机冷却系统节能改造

针对空压机冷却系统存在水泵、风机功率大,用电、水单耗高和冷却器易结垢堵塞,运行风险、成本高问题,采用将原来水(自来水)—风露天集中式冷却塔(一用一备),改造升级为一台空压机配置一台小型水(纯水)—水(自来水)闭式冷却塔的措施,达到空压机正常运行时一级、二级排气温度小于35°C,用电量节约40000 kWh/月,用水量节约3000m^(3)/月的效果,每年可节约用电、用水和冷却器更换成本共计约73.2万元。

离心式空压机进气预处理节能优化研究

从某制氧企业离心式空压机应用角度出发,利用冷却装置降低空压机进气口气体的温度和湿度,在实验中对进气预处理的节能效果进行验证。验证完成后,将其应用于该企业所有空压机当中,节能优化经济效果十分显著。

大功率水冷螺杆空压机换热分析与研究

功率为315 kW及以上的螺杆空压机在运行时会释放出大量的热量,为保证螺杆空压机的稳定运行,根据热力学第一定律及对流换热公式,通过对大功率水冷螺杆空压机热量分布及传热过程进行分析与研究,给出了螺杆压缩机组其冷却系统的设计计算方法:包括空压机的循环喷油量,油冷却器换热面积,后冷却器换热面积,冷却水进出水温度,冷却水塔换热参数,冷却水泵流量与扬程等参数进行了分析与计算,能够为大功率水冷螺杆空压机冷却系统的设计提供了较好的指导意义。

深冷空分装置工艺优化分析研究

以某工厂60000m3/h深冷空分装置为研究对象,利用Aspen Plus软件建立空分装置模型,并利用Aspen Plus灵敏度模块对模型中主精馏塔下塔的各部分工艺进行分析,提出优化方案.最后将优化工艺操作流程应用于某工厂中,通过不同负荷验证分析空分装置的节能效果,并探究具体产生的经济收益.

直接空冷火电机组乏汽余热利用技术

火电厂汽轮机排汽(乏汽)需要冷凝成液态水用于系统循环,湿冷、干冷机组都需要消耗大量能量来冷凝乏汽。北方缺水地区采用直接空冷火电机组,大量乏汽通过空冷岛散热。从热力学第二定律来看,乏汽已无做功能力,但是汽化潜热与做功能力无关,在能够提供真空环境确保乏汽流动性和需要加热远低于乏汽温度的工质的情况下,乏汽中的汽化潜热仍具有很高的回收价值。尤其对于直接空冷火电机组,其汽轮机排汽压力和温度均高于湿冷机组,可以采用汽水换热器直接回收乏汽热量加热厂区生水,降低电厂辅助蒸汽的消耗量,提高电厂收益。

Measures against the adverse impact of natural wind on air-cooled condensers in power plant

The natural wind plays disadvantageous roles in the operation of air-cooled steam condensers in power plant.It is of use to take various measures against the adverse effect of wind for the performance improvement of air-cooled condensers.Based on representative 2×600 MW direct air-cooled power plant,three ways that can arrange and optimize the flow field of cooling air thus enhance the heat transfer of air-cooled condensers were proposed.The physical and mathematical models of air-cooled condensers with various flow leading measures were presented and the flow and temperature fields of cooling air were obtained by CFD simulation.The back pressures of turbine were calculated for different measures on the basis of the heat transfer model of air-cooled condensers.The results show that the performance of air-cooled condensers is improved thus the back pressure of turbine is lowered to some extent by taking measures against the adverse impact of natural wind.

R1234yf电动汽车空调系统制冷性能的试验研究

为了实现汽车空调环保制冷剂要求,选用低全球变暖潜能值(GWP)制冷剂R1234yf,研究了环境温度对R1234yf空调系统制冷性能的影响,并在不同电子膨胀阀(EXV)开度和压缩机转速下对比了R1234yf系统和R134a系统的制冷性能。结果表明:当环境温度从27℃升至43℃,R1234yf系统排气温度升高18℃,功耗增大36.6%,制冷量和COP分别降低13.9%和55.7%;随着电子膨胀阀开度的增加,吸气过热度降低,制冷量和COP先增大后减小,各个转速下均存在一个最佳开度对应制冷性能最优;随着压缩机转速提高,排气温度升高,制冷量增大,但COP降低。当汽车空调系统中采用R1234yf制冷剂直接替代R134a时,虽然R1234yf系统的制冷量和COP比R134a系统分别平均降低4.5%和14.9%,但排气温度比R134a系统平均低5.2℃。该研究结果可为电动汽车空调系统制冷剂的替代研究提供参考。

Hybrid Chiller Plant Optimization Strategies for Hotel Building on Nile River of Egypt

Hybrid chiller plants (HCPs) using multiple chillers and different energy sources are highly recommended in several energy applications in non-residential buildings such as hospitals and hotels. Time of use and cooling load profiles are significant factors that should be carefully considered either in chiller plant design or in chiller sequencing operation. This article aims to present an operation planning of HCP which consists of both electric and non-electric chillers. Four operational strategies are proposed and solved to compare their coefficients of performance and economics of running costs. A typical hotel building located on the Nile river in Egypt is selected to perform the current thermal and economic case study. The total cooling load profile of this hotel building is 4000 refrigeration tonnage (TR), which is simulated to optimize chiller sequence of operation and to select optimal design conditions of both numbers for electric and non-electric chillers used in HCP. The results of this comparative study for running cost are defined using various design configurations with different several chiller sequences available for each configuration. Then, the results of COPs, and operational running cost and initial cost are presented in this article also. The comparison aims to find the optimal design and operational sequencing for HCPs on thermal basis and economic analysis which were attached in this article. Recommendations and suggestions for future work are attached at the end of this article.

电厂汽轮机空冷系统优化及节能降耗研究

汽轮机真空度是衡量汽轮机组运行效果的核心指标,真空系统的严密性则是影响汽轮机真空的重要因素。受凝汽器真空严密性差的影响,某电厂汽轮机组负荷逐年下降。本文结合该电厂汽轮机空冷系统运行现状,探寻电厂汽轮机空冷系统的优化方法,以期进一步降低汽轮机单位发电煤耗,有效促进电厂节能降耗,最终实现绿色发展。

纺织厂空压站通风降温与系统优化研究

为了改善陕西咸阳某纺织厂空压站内温度过高并且分布不均匀、现有通风系统对空压机组不能有效冷却降温的问题,在夏季测试了目前空压站内的温度和风速分布情况,借助CFD数值模拟作为辅助手段,用实测数据对空压站进行模拟,模拟结果与实测数据吻合,说明所建立模型是合适的。在此基础上,利用理论计算得出该空压站送风所需的最大风量,进而确定各个出风口的送风速度;用CFD来分析在最大风量下的温度场及速度场。结果表明:增大送风量、降低送风高度可对空压站有效散热、提升降温效果;同时从节能方面考虑,可采用在过渡季节将室外新风利用风管直接引入空压机吸入口的优化方案。

耦合碳捕集的直接空冷燃煤机组特性分析和背压优化

配置碳捕集技术将大幅改变直接空冷燃煤机组中汽机–给水和冷端系统的工质与能量分配,导致安全风险和经济损失。为提高耦合碳捕集的直接空冷燃煤机组发电效率,该文建立发电–碳捕集系统的全工况动态机理模型,分析变捕集率条件下子系统状态和整体经济性,揭示出捕集率对背压–发电功率和背压–风机耗功的影响规律,提出以热耗率最小为优化目标,以捕集率、锅炉负荷和环境参数为边界条件的背压优化方法。结果表明:每增大1%的CO_(2)捕集率对应1.06MW发电功率损失和15.2kJ/(kW·h)热耗率增量;背压优化降低了发电热耗约200~260kJ/(kW·h);捕集率为90%时,最优背压低至3.85kPa;高温、大风和高负荷时,捕集率的变化对最优背压影响较大。结果可为空冷燃煤–碳捕集整体系统的变工况高效运行提供决策依据。

空压机电气控制系统升级改造技术的研究与实践

某公司烧结空压机有4台美国复盛(FS-ELLIOTT P700)空压机,总功率6400KW,配套4台余热再生式空气干燥器,是公司最大的空压站。原为炼铁厂1、2#360烧结生产区、3#360烧结生产区、球团生产区和焦化厂提供生产用压缩空气,空压站与烧结余热发电机共用循环水冷却系统。随着公司转型升级的推进,发电机与烧结停产,但焦化厂、球团区域仍正常生产,空压站现有运行模式已无法满足转型生产的需要:空压机轴系密封存在缺陷,空压机软启动稳定性差,氮气气源停供,循环冷却系统与空压站不匹配,空压站系统运行稳定性差、供气单耗高等问题突出。为匹配公司生产模式,保证空压站高效稳定运行,为公司转型升级不间断提供生产用气,决定实施在线升级改造。

选煤厂压风管理系统智能化改造与应用

选煤厂压风系统给执行机构提供动力源。传统压风机组往往依据气路系统压力进行在线机组数量控制与出口压力调整,机组控制较为滞后,造成压缩机启停频繁,不利于系统风压稳定。通过对选煤厂压风管理系统的测压系统进行合理部署,对系统压力进行分析评估,获取系统的风压变化特性,结合压风机组状态,对压风机组进行智能控制,稳定系统压力的同时,达到节能增效的目的。

医药氯化钠生产厂房冷风系统设计优化及效果分析

某大型生产厂房主要生产氯化钠原料药,受到制备工艺及环境温湿度条件的影响,该原料药的生产及储存过程中存在盐粒受潮结块/潮解等问题。对产品生产及存储过程中的冷风系统进行设计优化,对比不同优化方案下原料药的品质。结果表明:采用恒温恒湿仓储系统及沸腾床新风预处理及低温除湿机优化相结合的优化方案能够使干燥的原料药含水量降低19.43%,内包的原料药含水量降低20.58%,使得月平均收益提升到原系统的5倍。

46^(#)螺杆空气压缩机冷却液的研制

针对用户的特殊需求,研究制定了高于国标要求的46^(#)螺杆空气压缩机冷却液的质量指标,通过选择基础油和筛选功能性添加剂,确定了产品最终的研制方案。所研制的产品各项性能均满足指标要求,且黏度指数、倾点、闪点等性能高于指标要求。该样品在螺杆空气压缩机上进行工业试用后,效果良好。