炼化企业低温余热利用技术探讨＊

目前炼化企业有大量的低温余热需要回收,了解低温余热的来源、回收途径和技术,对提高低温余热利用效率十分重要。文章对炼厂低温余热的主要来源、利用途径和技术进行综合分析,提出炼厂低温余热回收利用的一些建议。     

利用炼化RO浓水再生阳离子树脂研究

对几种树脂的吸附容量开展进水浓度梯度实验.考察常见干扰因子对树脂吸附的影响情况·并使用现场水样考察了实际情况下的树脂可重复利用性,筛选出适用于本实验的树脂。使用NaCl对饱和树脂进行再生.寻找浓度和用量对树脂再生效果的影响。最终,使用炼化反渗透(RO)浓水对饱和树脂进行再生,分析得出可以使用炼化RO浓水再生树脂的结论。     

燃煤锅炉低温烟气余热利用探讨

针对燃煤锅炉燃烧产生的低温烟气仍具有一定温度的现象,提出通过增设超导热管空气预热器对这部分低温烟气余热加以回收的设想,对锅炉送风进行预热,探讨烟气余热利用可达到的送风温度、节能效果及可能产生的经济效益。     

关于炼化企业水资源利用的几点思考

通过对我国水资源状况及石化行业水消耗情况分析,找出我国石化企业新鲜水用量,污水排放在绝对量,吨原油、万元产值的单耗,单排等方面与国外相比较存在的差距。指出存在的主要问题是:清污分流不彻底;污污分流不健全;汽提后的净化水回用量小;新鲜水冲洗地面及作为机泵冷却水直排,导致新鲜水的浪费。同时针对以上问题提出相应的建议参考指标及对应措施。     

污水深度处理及回收利用的可行性分析

大庆炼化公司从单一化工污水深度处理及回收利用发展为炼油、化工、生活污水统一处理和回用于循环水,既充分利用了现有污水处理场的处理余量,同时由于生活污水中含有比例适当的微生物需要的营养物质,对炼油和化工污水起到补充和稀释作用。这种处理方法既降低了工业污水对污水处理场的冲击,又起到了稳定水质的作用。     

高含盐水利用余热浓缩减排技术试验研究

风城油田稠油以SAGD开采方式为主,对蒸气过热度提出了更高要求。目前生产区域采出液余 热利用效率低,系统排放高含盐水得不到有效处置。文章通过对地面水-热综合系统分析,提出高含盐水利用余 热浓缩减排的技术路线,采用空气蒸发技术实现高含盐水减量化,水蒸发进入空气,空气中水蒸气冷凝回收。现场试验结果表明：采用该技术可实现采出液所携带的低品质热能再利用,能将高含盐水转化为满足锅炉用水 指标的冷凝水,其高含盐水减量＞60％,冷凝水矿化度≤600mg/L,水处理成本＜10元/m3。     

气田增压机组烟气余热利用技术

综述国内外烟气余热利用技术的研究及应用现状,主要包括热能直接回收、吸收式制冷、有机朗肯循环和温差发电等方式。结合气田开采实际,分析讨论各类余热利用技术在气田增压机组烟气余热利用中的应用潜力和发展方向。在选择余热利用方案时,应结合气田增压机组现有条件、机组性能以及运行模式等因素进行综合评估。     

对完善炼化企业HSE管理体系的思考

针对部分中国石油炼化企业HSE管理体系存在的管理层认识不到位、管控能力和执行力不足、管理重复、资源浪费、安全生产基础薄弱、安全生产责任履行不到位、作业管理过程不规范、体系推进工作急于求成、培训和评估不够等问题,对炼化企业HSE管理体系的完善提出建议。     

基于生产过程的炼化企业碳源识别

参照国际标准,企业传统碳源划分为直接排放源、间接排放源和其他排放源,难以体现炼化企业碳排放多渠道、多元化的特征。结合炼化企业生产特点,从污染物全过程控制角度将碳源再划分为原材料及能源输入、产品生产、污水处理3个环节,提出原材料及能源输入低碳化,实现碳排放源的源头控制;产品生产环节低碳化,实现碳排放的过程控制;污水处理环节低碳化,实现碳排放的末端控制。基于生产过程的炼化企业碳源识别,以期协调解决能源生产和碳排放冲突的矛盾,为炼化企业开展节能减排提供依据。     

重庆市应用湖库水水源热泵系统条件分析

通过对重庆市气候条件、湖库水水资源状况以及湖库水水温和水质分析,结果显示:重庆地区采用传统空气源热泵系统已不适宜,而采用水源热泵系统具有较高的节能优势。丰富的湖库水水资源量以及重庆市建筑沿湖库水而建特点,为在重庆市开展湖库水水源热泵系统创造便利条件;湖库水水温和水质基本能满足地表水水源热泵系统的水源要求;湖库水藻类易爆发,因此发展湖库水水源热泵主要解决的水质问题是藻类的堵塞问题。     

Benefit‐Cost Analysis of Integrated Water Resource Management: Accounting for Interdependence in the Yakima Basin Integrated Plan

Integrated water resource management (IWRM) requires accounting for many interrelated facets of water systems, water uses and stakeholders, and water management activities. The consequence is that project analysis must account for the nonseparability among the component parts of IWRM plans. This article presents a benefit‐cost (B‐C) analysis of a set of projects included in the Yakima Basin Integrated Plan proposed for the Yakima Basin in south‐central Washington State. The analysis accounts for interdependence among proposed water storage projects and between water storage and water market development in the context of historical and more adverse projected future climate scenarios. Focusing on irrigation benefits from storage, we show that the value of a given proposed storage project is lower when other proposed storage projects in the basin are implemented, and when water markets are functioning effectively. We find that none of the water storage projects satisfy a B‐C criterion, and that assuring proposed instream flow augmentation is less expensive by purchasing senior diversion rights than relying on new storage to provide it.     

重点流域水生态环境保护“十四五”规划编制思路与重点

本文主要对《重点流域水生态环境保护"十四五"规划编制技术大纲》进行解读,在梳理当前我国流域水生态环境保护现状、问题以及形势的基础上,分析了重点流域水生态环境保护"十四五"规划的定位,介绍了规划编制的总体思路以及目标制定、问题和症结分析、规划任务设计和项目筛选等重点环节,并对做好规划编制工作提出了相关建议。     

A Comparison of Three Federal Datasets for Thermoelectric Water Withdrawals in the United States for 2010

Historically, thermoelectric water withdrawal has been estimated by the Energy Information Administration (EIA) and the U.S. Geological Survey's (USGS) water‐use compilations. Recently, the USGS developed models for estimating withdrawal at thermoelectric plants to provide estimates independent from plant operator‐reported withdrawal data. This article compares three federal datasets of thermoelectric withdrawals for the United States in 2010: one based on the USGS water‐use compilation, another based on EIA data, and the third based on USGS model‐estimated data. The withdrawal data varied widely. Many plants had three different withdrawal values, and for approximately 54% of the plants the largest withdrawal value was twice the smallest, or larger. The causes of discrepancies among withdrawal estimates included definitional differences, definitional noise, and various nondefinitional causes. The uncertainty in national totals can be characterized by the range among the three datasets, from 5,640 m³/s (129 billion gallons per day [bgd]) to 6,954 m³/s (158 bgd), or by the aggregate difference between the smallest and largest values at each plant, from 4,014 m³/s (92 bgd) to 8,590 m³/s (196 bgd). When used to assess the accuracy of reported values, the USGS model estimates identify plants that need to be reviewed.     

浅析油气田回注污水余热的利用——以辽河油田公司沈阳采油厂为例

辽河油田公司沈阳采油厂的原油伴生水,平均温度47℃,若不加以利用地将温水直接回注到地层,将会造成热能浪费。如果通过余热利用,则节约能源。文章通过现状调查、经济、技术、政策可行性分析认为:沈阳采油厂污水余热的可挖潜力很大,回用污水余热在技术与政策方面均有较大的可行性且具有可观的经济效益。     

A System Dynamics Model for Conjunctive Management of Water Resources in the Snake River Basin

The Pacific Northwest is expected to witness changes in temperature and precipitation due to climate change. In this study, we enhance the Snake River Planning Model (SRPM) by modeling the feedback loop between incidental recharge and surface water supply resulting from surface water and groundwater extraction for irrigation and provide a case study involving climate change impacts and management scenarios. The new System Dynamics‐Snake River Planning Model (SD‐SRPM) is calibrated to flow at Box Canyon Springs located along a major outlet of the East Snake Plain Aquifer. A calibration of the model to flow at Box Canyon Springs, based on historic diversions (1950‐1995) resulted in an r² value of 0.74 and a validation (1996‐2005) r² value of 0.60. After adding irrigation entities to the model an r² value of 0.91, 0.88, and 0.87 were maintained for modeled vs. observed (1991‐2005) end‐of‐month reservoir content in Jackson Lake, Palisades, and American Falls, the three largest irrigation reservoirs in the system. The scenarios that compared the impacts of climate change were based on ensemble mean precipitation change scenarios and estimated changes to crop evapotranspiration (ET). Increased ET, despite increased precipitation, generally increased surface water shortages and discharge of springs. This study highlights the need to develop and implement models that integrate the human‐natural system to understand the impacts of climate change.     

A Water Yield‐Oriented Practical Approach for Multifunctional Forest Management and its Application in Dryland Regions of China

Mountainous forest areas are vitally important for water supply in dryland regions which suffer from high erosion risk and severe water shortage. Massive afforestation, mainly for erosion control, may reduce the water yield and threaten local water supply security. Moreover, many over‐dense forests due to a strict logging ban policy have produced remarkably negative impacts for both forests (e.g., low timber quality, restricted natural regeneration, and high stand instability) and water yield. To satisfy the rapidly increasing demands on water supply and other services, a practical approach for managing forest stands in a multifunctional way, which particularly addresses water yielding, is urgently required. For this purpose, we integrated the existing knowledge and experience, designed an “ideal” stand structure to represent multifunctional forest (MFF) and determined its key parameters (a ground coverage of >0.7, a canopy density around 0.7, and an H/DBH ratio (tree height [m] to the diameter at breast height [cm]) of <0.7). Moreover, a decision process for MFF stand management was recommended as: (1) investigating the site quality; (2) identifying the site‐specific main forest functions; (3) quantifying the stand structure; (4) diagnosing the stand structure by comparing with the “ideal” one; and (5) arranging the functions/structure‐oriented management measures. In this way, the water‐yielding function can be improved and meanwhile other forest functions can be promoted.     

A Hierarchical Model for Estimating Long‐Term Trend of Atrazine Concentration in the Surface Water of the Contiguous U.S.

Atrazine is a herbicide frequently detected in both surface and groundwater in the United States (U.S.), but its spatiotemporal distribution and concentration trends have only been analyzed recently at regional or local scales. We employed a Bayesian hierarchical modeling approach to assess spatial and seasonal variation in atrazine concentration trends between 1990 and 2010 for the contiguous U.S. A Markov chain Monte Carlo simulation algorithm was used to address the problem of left‐censored data (i.e., atrazine concentration values below method reporting levels). We observed opposing temporal trends in the northern (flat or decreasing) and southern (increasing) regions of the U.S. This spatial variation in temporal trends can be partially explained by the relative amount of cropland in the region. Flat or decreasing trends in the north are more likely in regions with high cropland coverage while positive trends in the south are more likely in regions with low cropland coverage.