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144.
John A. Veil Markus G. Puder Debra J. Littleton David O. Moses 《Environmental Science & Policy》1999,2(6):515
Cooling water is used by many industrial facilities. The largest user of cooling water is the electric power industry, although other significant users include the pulp and paper, chemical, iron and steel, aluminum, and petroleum refining industries. The US Environmental Protection Agency (EPA) is currently developing regulations to implement section 316(b) of the Clean Water Act, which deals with cooling water intake structures. The EPA will examine cooling water use patterns at various industries. Data pertaining to cooling water use patterns at utility plants are readily available; however, no information has been assembled for cooling water use at electric power generating facilities owned or operated by entities other than utilities (nonutilities). This paper presents data concerning cooling water use from two subsets of the nonutility sector and focuses on plants using once-through cooling systems. The first subset includes 123 nonutility plants that each generate at least 150 MW of power. Collectively, they represent 41,494 MW of generating capacity, or about 56% of the total nonutility generating capacity. Approximately 17% of the installations within that subset utilize once-through cooling water. The second subset includes 58 waste-to-energy facilities, which individually produce less than 80 MW but collectively generate about 2200 MW. Only 11% of this subset of plants uses once-through cooling water. The total 15,372 MW generated by once-through nonutilities is equivalent to only 6% of the 258,906 MW generated by utilities utilizing once-through cooling. From a national perspective this share may appear relatively insignificant. However, in some states, the nonutility once-through total is equivalent to a more significant percentage of the utility once-through total. 相似文献
145.
再生水深度处理系统的设计简述,以及调试运行对设计参数的修正和调整,提出了对今后系统设计应注意的细节。 相似文献
146.
以某电厂冷却塔循环冷却水为处理对象,利用电絮凝法,以铝板为牺牲阳极去除水中的Ca2+和Mg2+,分别考察了电絮凝过程中不同电流密度、电解时间、溶液初始pH、阳极极板数量对总硬度去除率的影响。结果表明:增加电流密度、延长电解时间有利于Ca2+和Mg2+的去除;当电流密度为10 mA·cm−2,电解时间为90 min时,Ca2+和Mg2+去除率分别达到93.5%和95.8%,总硬度去除率为94.6%;相对于酸性和中性条件,碱性条件更有利于Ca2+和Mg2+的去除,当初始pH为10时,Ca2+和Mg2+去除率分别达到85.4%和97.7%,总硬度去除率为93.5%;随极板数量的增加,Ca2+和总硬度去除率均有所提高;投加Na2CO3有利于Ca2+和总硬度的去除。上述结果可为进一步提高电絮凝过程中总硬度的去除率提供参考。 相似文献
147.
炼钢连铸冷却喷淋水中的高含油量易形成黏性油泥团,堵塞管道和设备,导致处理后的水难以达到回用水质的要求,除油降浊是其处理稳定达标的关键环节。为了寻求对连铸含油冷却喷淋水处理工艺简单、投资少、费用低、效率高的絮凝/吸附处理工艺及方法,实验制备了粉煤灰/聚合硫酸铁复合材料(PFA),表征了其结构、形貌,研究了其除油降浊的最佳pH值、反应温度、最佳配比、最佳投加量等,并从处理效率、投药成本、除浊率等方面考虑,确定最佳运行条件:pH为7~8,反应温度为50℃,搅拌300 r·min-1左右,反应3 min,静置10 min,粉煤灰/聚合硫酸铁的配比为100:8~100:18,投加量为80~220 mg·L-1。处理后水样含油浓度为低于5 mg·L-1、循环水处理成本低于0.1元·(t水)-1,除浊率为89.5%,满足实际生产使用要求,达到炼钢废水循环利用的目的。 相似文献
148.
直升机蒸气循环制冷系统技术现状与展望 总被引:2,自引:0,他引:2
笔者主要从舱内环境控制方面 ,分析了高温对直升机飞行安全的影响 ,指出了直升机安装制冷系统的必要性 ,同时对国外现役直升机采用的两种制冷系统即蒸气循环制冷系统与空气循环制冷系统进行了性能对比。在此基础上 ,提出我国发展直升机制冷系统的主推方案是蒸气循环制冷系统 ,并对我国进行直升机蒸气循环制冷系统研究的技术关键和发展方向给予展望 ,为我国开展此领域的科学研究和技术创新提供一定的技术储备。 相似文献
149.
介绍了不锈钢电炉烟气的冷却降温方法设计参数,技术特点以及除尘系统的组成、每种设备的规格性能,特别是对脉冲除尘器做了详细阐述。对不锈钢电炉除尘工程的设计、管理,具有参考和借鉴作用。 相似文献
150.
Ahmed Elsayed Raya K. AL-Dadah Saad Mahmoud Waseem Kaialy 《International Journal of Green Energy》2018,15(5):277-285
Commercially available adsorption cooling systems use water/silica gel, water/zeolite and ammonia/ chloride salts working pairs. The water-based pairs are limited to work above 0°C due to the water high freezing temperature, while ammonia has the disadvantage of being toxic. Ethanol is a promising refrigerant due to its low freezing point (161 K), nontoxicity, zero ozone depletion, and low global warming potential. Activated carbon (AC) is a porous material with high degree of porosity (500–3000 m2/g) that has been used in wide range of applications. Using Dynamic Vapour Sorption (DVS) test facility, this work characterizes the ethanol adsorption of eleven commercially available activated carbon materials for cooling at low temperature of ?15°C. DVS adsorption results show that Maxsorb has the best performance in terms of ethanol uptake and adsorption kinetics compared to the other tested materials. The Maxsorb/ethanol adsorption process has been numerically modeled using computational fluid dynamics (CFD) and simulation results are validated using the DVS experimental measurements. The validated CFD simulation of the adsorption process is used to predict the effects of adsorbent layer thickness and packing density on cycle uptake for evaporating temperature of ?15°C. Simulation results show that as the thickness of the Maxsorb adsorbent layer increases, its uptake decreases. As for the packing density, the amount of ethanol adsorbed per plate increases with the packing density reaching maximum at 750 kg/m3. This work shows the potential of using Maxsorb/ethanol in producing low temperature cooling down to ?15°C with specific cooling energy reaching 400 kJ/kg. 相似文献