Evaporative Cooling Applied in Thermal Power Plants:A Review of the State-ofthe-Art and Typical Case Studies

A review is conducted about the application of the evaporative cooling technology in thermal power plants.Different case studies are considered,namely,evaporative air conditioners,evaporative cooling in direct air-cooled systems,gas turbine inlet cooling,wet cooling towers,and hybrid cooling towers with a crosswind effect.Some effort is provided to describe the advantages related to direct evaporative cooling when it is applied in thermal power plants and illustrate the research gaps,which have not been filled yet.In particular,typical case studies are intentionally used to compare the cooling performances when direct evaporative cooling is implemented in different types of cooling towers,including the natural draft wet cooling tower(NDWCT)and the pre-cooled natural draft dry cooling tower(NDDCT).It is shown that the NDWCT provides the best cooling performance in terms of power station cooling,followed by the pre-cooled NDDCT,and the NDDCT;moreover,the evaporative pre-cooling is able to enhance the cooling performance of NDDCT.Besides,on a yearly basis,better NDDCT cooling performances can be obtained by means of a spray-based pre-cooling approach with respect to wet media pre-cooling.Therefore,the use of nozzle spray is suggested for improvement in the performance of indirect/direct air-cooling systems with controlled water consumption.

Atmospheric Dry Deposition in the Proximity of Oil-Fired Power Plants at Mexican Pacific Coast

Dry deposition samples were collected in a weekly basis during 2010 in a site located at the Mexican Pacific Coast: Manzanillo, Colima. Samples were collected with an automatic wet/dry deposition sampler using nylon filters as surrogate surfaces. Samples were extracted with deionized water and analyzed for pH, conductivity, Na+, K+, Ca2+, Mg2+, NH4-, NO3-, SO42- and Cl-. Nitrate and sulfate were the most abundant ions, contributing with 53% to the total ionic mass;and their levels exceeded the hemispheric background concentrations proposed for marine remote sites. The influence of the power plants burning combustoleo located upwind the sampling site was completely evident. From meteorological analysis, it could be observed that the sampling site was all time under the influence of power plants as a result of the effect of breezes. However, in spite of the high levels of NO3- and SO42- found in the samples collected, pH value average was almost neutral, with 28% of samples slightly acid. Potassium was the most abundant cation and from the quantification of the neutralization effect of the main alkaline components, the prevalence role of K+ was completely evident, suggesting the influence of the mining complex Pe?a Colorada located upwind the sampling site, where amyl xanthate potassium is used as collector in tailing dams. Dry deposition fluxes were estimated for all ions measured. Nitrogen dry deposition at Manzanillo is already in the upper extreme of the threshold value reported for sensible ecosystems. On the other hand, sulfur deposition exceeded slightly the critical load value reported for some ecosystems in Europe. Even at this moment, nitrogen and sulfur deposition is not a problem, it is necessary to take steps to avoid that total deposition of these elements exceeds critical loads, considering that results reported in this study not include the wet deposition fluxes.

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.

Modeling the Effect of Thermal Diffusion Process from Nuclear Power Plants in Vietnam

In this study, we evaluate the ecological impact of effluent cooling water from the Ninh Thuan nuclear power plant II, using a two-dimensional hydraulic model to simulate thermal diffusion from the effluent outfall. Sites selected for this study were Ninh Thuan nuclear power plant and Vinh Hai seawater in four different scenarios. This paper utilized the relationship between surface water temperature and the water temperature at a depth of -15 m to calculate the water temperature at intake and outlet at a depth of -14 m. A combination between the results of interpolated and results of model showed that effluent cooling water from Ninh Thuan plant affected the largest incidence about 2450 m in the North, 880 m in the South and 960 m in the West. It can be considered as safe distance to not to affect the coral reefs ecosystem in the North and sea turtle conservation area in the South. This study was first in this region to have an integrated approach using two-dimensional model.

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.

A New Water Saving Device of Swirling Flow for Cooling Towers

This paper is concerned with water saving for water-loop cooling tower system in power plants. A newly developed water saving device of swirling flow is presented. The key point is that the new water saving device makes the steam swirl up along the device wall rather than engender laminar flow in a corrugated plate. The corrugated plate device can save approximately 10 percent of the total lost water. In contrast to the scale model of corrugated plate water saving device, experimental analyses have demonstrated that the new water saving device of swirling flow is more efficient, with a capacity of saving more than 20 percent of water.

探究火电厂水耗降低方案及实施方法

火电厂水耗量过大时,将会影响厂内效益,不利于促进可持续发展。基于此,本文主要针对火电厂水耗降低方案及实施方法进行探讨,首先分析了水耗来源,基于水耗降低意义探究实际方案与实施方法,重点阐述了锅炉、冷却系统、废水处理技术改进方法,最后结合实际案例剖析水耗降低实施内容,以增强技术参考性。研究发现,火电厂水耗降低有利于降低成本费用,推动全厂实现绿色发展,类似工厂应持续加强水耗控制,实现生态生产。

Considering for the blanket structure scheme of HCCB DEMO

For the solid blanket concept of helium cooled ceramic breeder (HCCB) demonstration fusion power plant (DEMO), a feasible blanket structure with configuration 2×X is proposed as considering relatively low temperature limit of neutron multiplier beryllium pebbles. Based on that, preliminary design for the typical blanket module of HCCB DEMO has been carried out and verified by thermal-hydraulic analysis and structural analysis. Furthermore, the specific relationship of maximum temperature depended on the surface heating of blanket key part first wall (FW) is also analyzed.

Water-Energy Prototype Model for the NEMS Modeling Platform: Thermoelectric Water Demand and Its Implications on Regional Electricity Market

A simplified energy-water prototype model has been developed at the National Energy Technology Laboratory (NETL) as a part of a larger effort to comprehensively model energy-water interactions. The NETL Water-Energy Model (NWEM) prototype passively couples a variety of data on water supply, water availability, and power plant water use with the National Energy Modeling System (NEMS) power generation forecasts. NWEM operates at a watershed level and its efficacy in resolving local water supply and water-use trade-offs was demonstrated using data from Sandia National Laboratory along with a water supply scenario projected by the World Resources Institute (WRI). The prototype model only passively utilized a forecast of power generation from an existing forecast;the model’s choices were limited to purchases or retrofitting to meet future water supply constraints. NETL is continuing to integrate the water sub-module into the NEMS framework, which will allow active interaction between the water market and power markets, extending the industry’s ability to re-dispatch its generating units with the price of water as one of the variable costs.

Radiative cooling and cold storage for concentrated solar power plants

Concentrated solar power(CSP)plants are generally located in solar-abundant yet hot and water-stressed loca-tions.In such circumstances,efficient but water-intensive once-through wet cooling and water-free but inefficient air cooling are both unfavorable.Considering both thermal efficiency and water availability/temperature,recir-culating evaporative cooling is a better alternative.However,evaporative cooling still loses large amounts of water into the atmosphere and thus requires a nonstop water supply.Therefore,simultaneously reducing water loss and maintaining thermal efficiency requires efficient means of supplemental cooling for CSP plants.Follow-ing our previous work on scalable radiative cooling films and a kW-scale radiative cooling system,we explore the potential of consumptive water use reduction in recirculating wet-cooled CSP plants by integrating supplemental radiative cooling and cold storage.Through modeling of a reference CSP plant with a supplemental radiative cooling system as large as the plant solar field,the results show that 40%-60%of the annual consumptive water use can be potentially reduced in the hot southwestern U.S.region with daytime-only radiative cooling,whereas the annual potential water saving can be as much as 65%-85%if the radiative cooling system works both day and night with cold storage.

电化学循环水阻垢技术在电力行业的应用展望

在工业发展中,循环冷却水的结垢问题一直备受关注,有效的阻垢技术对降低生产能耗和减少水资源的浪费具有重要意义。电化学阻垢技术因具有高效、无需投加药剂、同步杀菌等优点受到了广泛的关注。从电化学阻垢技术的发展、原理以及实际应用等方面,综述了电化学阻垢技术在循环冷却水处理中的应用情况并展望了在电力行业冷却水处理中的应用前景。包括以时间为向导结合文献计量学可视化分析,比较了近十年阻垢技术相关研究热点;进一步从电化学阻垢技术的简介、与传统阻垢技术的比较、研究现状以及影响因素出发,并结合实际应用情况,提出了电化学阻垢技术尚且存在的困难和挑战,最后对电化学阻垢技术在电力行业中的应用前景进行了展望。

凉水塔变形监测与基坑敏感因子灰色关联分析

基坑开挖容易引起临近电厂凉水塔变形,是深基坑工程面临的主要难题之一。本文实地监测深基坑开挖对附近电厂凉水塔的影响,统计了基坑开挖过程中凉水塔地表垂直和水平位移、结构变形等参数。依托某实际工程,研究基坑开挖引起凉水塔变形预测方法,建立凉水塔地表垂直位移灰色预测模型。采用灰色关联分析确定基坑各敏感因素对凉水塔变形的影响程度,由大到小依次为:基坑与建筑物间距、土体弹性模量、围护结构厚度、土体内摩擦角、土体粘聚力。通过开展凉水塔变形监测与相关研究工作,相关研究理论能够为类似深基坑工程提供参考。

大型直流冷却火电厂用水特征分析

直流冷却火电厂是我国工业用水大户,随着水资源短缺问题日益严重、节水要求日益提高,开展直流冷却火电厂用水特征分析研究,为节水改造提供技术支撑,愈发紧迫。文章以中山嘉明电厂为例,对其开展水平衡测试工作,确定电厂用水结构,推演用水参数及各系统用水指标,进行节水潜力分析并提出节水措施。分析结果显示,直流冷却是该类电厂主要的用水、退水环节,电厂用水指标满足相关定额要求,但在除盐水回用等方面仍有一定的节水潜力。测试及分析的开展为大型直流冷却火电行业节水改造、节水企业创建提供了一定的参考和借鉴。

发电厂冷却工艺用水发展现状与展望

冷却工艺用水是发电厂总用水量的主要部分。随着全球淡水资源持续紧缺,改进冷却工艺系统、提高冷却水使用效率的必要性和迫切性日益凸显。从多个方面对发电厂冷却工艺节约用水进行了论述,概述了现有冷却工艺的局限性;介绍了对发电厂冷却系统进行改进和优化以实现节水、降耗的新工艺;探讨了以海水和再生水为代表的非传统水源应用于冷却系统的可能性,以及将其应用于冷却工艺时可能面临的复杂性和挑战;介绍了冷却水处理和水质监测的关键技术,阐述了相关技术改进所能带来的节水效果;最后提出了冷却水管理方面存在的机遇与挑战。

火电厂源侧综合能源系统集成及性能评估研究

本文建立了以火电厂为核心,消纳可再生能源并提供冷热电汽综合能源服务的一套能源系统,通过对整体系统及关键子系统热力性能分析,验证了提出模型和方法的有效性。并研究了一些关键运行参数对系统综合性能的影响,验证了提出模型和方法的有效性和优越性。结果表明:通过改变火电厂的源侧参数,可以提高综合能源系统荷侧的输出量;且生物质转化气对汽轮机发电功率的影响最大。热泵系统的负荷随着进入系统中的给水流量的增大而增大,利用汽轮机中的部分抽汽来驱动热泵系统,虽然发电功率下降了10.88%,但是却为用户提供了16.8MW的热负荷和16.2MW的冷负荷以及27.78t/h的蒸汽量。

基于热泵技术的余热回收供热系统

传统热电厂的循环冷却水中含有大量的低品位余热,利用热泵技术对其进行回收,能够显著提升供热系统的能源利用效率,有利于实现节能减排和“碳中和”目标。设计基于单、双吸收式热泵机组的余热回收供热系统,旨在有效利用循环冷却水中的余热,增加供热能力并分析系统性能。结果表明,与传统供热系统相比,两种余热回收供热系统均可显著回收循环冷却水的热量,提高系统供热量并大幅减少能源消耗,带来可观的经济收益;双吸收式热泵机组系统展现出更优异的热力性能,具备显著的节能减排优势。分析循环冷却水入口温度和一次网回水温度对双吸收式热泵机组性能的影响,发现循环冷却水温度对系统性能影响较大,随着循环冷却水温度的升高,系统的供热量增加比例、节约标煤量和新增供热面积均增加,而一次网回水温度对系统性能的影响较小,随一次网回水温度的升高,系统的供热量增加比例、节约标准煤量和新增供热面积几乎不变。

基于纳滤的火电厂循环冷却水分质浓缩研究

推进分质梯级用水和废水近零排放是当前火力发电行业绿色转型阶段的重要发展方向.火电厂循环冷却水因水量大但循环利用不足而成为当前发展面临的瓶颈问题.本研究针对循环冷却水水质特点,提出基于纳滤技术进行冷却水分质浓缩的处理方案.对一、二价离子进行选择性分离,将富含Ca^(2+)、Mg^(2+)的浓水用于辅助烟气脱硫;将净水回用于循环冷却工段,旨在控制冷却塔结垢等问题的同时,提升火电厂整体水资源利用率.系统对比了5种商业纳滤膜(NF245、NF270、DF30、DF90、XCN)的分质浓缩特性.优选并使用XCN膜对实际循环冷却水进行纳滤分质浓缩,在10%水回收率时可实现对Ca^(2+)、Mg^(2+)大于97%的高截留,而对Na+的截留率稳定在20%,离子选择性S Na/Mg和S Na/Ca分别可达36.7和30.5,展现出良好的应用潜力.

2023年冬季宁德核电冷源海域棘头梅童鱼(Collichthys lucidus)资源声学评估

滨海核电厂冷却水源的取水安全正受到海洋生物暴发引起的堵塞威胁,鱼类堵塞核电冷源的事件时有发生。声学技术在海洋生物探测方面具有高效、实时的优势,因此,被广泛应用于海洋生态系统研究。为了解冬季宁德核电厂冷却水源取水海域棘头梅童鱼(Collichthys lucidus)的密度和运动规律,利用声学技术对相关海域冷却水源生物量进行了测量和评估。研究结果显示,棘头梅童鱼为研究海域的优势种,拖网调查显示平均尾数密度为1964尾·km^(-2),平均质量密度为0.483 kg·km^(-2)。棘头梅童鱼丰度在研究海域向核电厂方向减少,质量密度以核电厂温排水区域站点最高。通过对鱼类回波特征和个体轨迹的追踪统计,分析了该海域冬季内单体目标强度检测及其空间结构分布、资源现存量和资源丰度密度的时空分布变化。声学走航海域鱼类平均密度为2.78×10^(5)尾·n mile^(-2),生物量密度均值为1.41×10^(4) kg·n mile^(-2),棘头梅童鱼资源总量为7.47×10^(5) kg。研究表明,声学技术在宁德核电厂取水海域冬季冷却水源生物量测量中具有明显优势。通过不断改进和优化方法,声学技术将能更好地支持核电厂取水海域的生态环境监测与资源管理,为冷却水源取水安全提供科学依据。

核电厂温排水余热利用与集中供热供冷研究

针对核电厂的温排水直接排放造成热岛和能源浪费等问题,提出一种利用海水源热泵机组吸收核电温排水余热来制55℃热水的系统,同时利用该热泵机组吸收核电厂取用的冷海水制6℃的冷水或厂外冷水机组制冷水,详细介绍了利用该系统来制热水和冷水并进行集中供热、供冷的方案,并对其经济环保效应进行了分析。结果表明,该余热利用系统可实现核电厂区、生活区等多区域的集中供暖、供冷和卫生热水“三联供”服务;该余热利用方法的节能效果比传统空调和电热水器分别高39%和55%,且核电厂外用户区的经济性距离约为8 km;温排水余热利用必须统筹考虑供热、供冷及供卫生热水,供热与供冷的经济性贡献接近一半。研究结果可为核电余热利用提供重要参考。

基于相变蓄冷的核电厂主控室非能动冷却系统

为提高现有核电厂主控室紧急可居留系统的蓄冷能力及热舒适性水平,提出了基于定形相变蓄冷材料的核电厂主控室非能动冷却系统。基于主控室热负荷分布情况,该冷却系统在主控室顶板与吊顶之间、内墙面、地板底面及循环风道内,针对性地布置相应的含有定形相变材料的非能动冷却装置,进而实现事故工况下对主控室温度的精确控制。该非能动冷却系统无需引入额外冷源和管道,可靠性强,同时不破坏主体结构,且可灵活布置,解决了现有主控室非能动热阱时间余量小、热舒适性差的问题。