气源转换对炮气输配管网的影响及其对策

气源从工煤气转换为天然气或液化石油气后，对输配管网可能造成的影响包括１铸造管道接口漏气；２管道内尘土飞扬；３室内镀锌管丝扣拉头漏气；４室内镀锌管和气柜锈蚀加剧。文末提出３点对策。     

武汉市天然气气源分析

中国天然气行业已进入深化改革阶段,面对天然气管网的多气源供应局面,如何确保多种气源在城市燃气管网中安全、可靠地输送,是一个技术难题。本文以武汉市天然气有限公司为例,结合行业改革特点、上海石油天然气交易中心的建立以及武汉市气源的新特点,为公司科学开展气源调配工作提出了建议。     

天津市天然气输配系统规划

以天津市为例,介绍城市天然气输配系统现状,对气源及厂站规划、管网规划、调度抢险服务设施规划进行了探讨.     

天津市天然气气源与管网的合理布局

本文介绍了天津天然气气源现状，提出了编制城市燃气管网规划应注意的问题     

厦门市气源转换的技术分析

分析了气源转换时原有输配系统的管道、调压设备、计量设备、用气设备与天然气系统相适应的问题，提出了相应的措施。     

多气源燃气管网水力计算程序的开发

在单气源燃气管网水力计算程序的基础上,利用解节点方程法,采用管段、节点自动编号,开发了多气源水力计算程序,通过实例进行验证。     

贵阳市天然气输配系统规划探讨

贵州省内两条天然气长输管道已建成开通,贵阳市中心城区燃气气源转换为天然气。介绍贵阳市燃气输配系统现状,对供气规模和天然气气源、应急调峰规划、厂站规划、管网规划进行了探讨。     

天然气多气源混输系统的安全性分析

天然气省级管网是一个多气源混输系统,存在气源多元化、压力超高压化、管网结构复杂的特点,系统运行过程中可能出现输气能力、接收能力、调峰与气质互换性方面的安全性问题。对这些安全性问题进行分析,对提高系统安全性提出了建议。     

天然气转换与储气方案的分析

分析了厦门市现有气源(液化石油气混空气)向天然气转换后,燃气灶具、输配管网、调压装置再利用的可能性,对储气方式进行了技术经济比较,推荐了高压球罐与高压、次高压管道相结合的储气方案。     

杭州市燃气气源转换过程中有关问题的探讨

探讨了气源转换时原有输配系统的管道设施、调压设备、计量设备、用气设备与天然气系统相适应的问题,提出了相应的改造措施;分析了天然气门站置换、天然气置换空混气和人工煤气等气源置换技术。     

某地源热泵系统经济技术比较及节能分析

本文结合实际工程,通过对地源热泵、冷水机组+燃气锅炉、冷水机组+城市热网三种系统方案进行经济技术比较,确定采用地源热泵空调系统。根据DeST的模拟结果分析地下全年累积热量状况,确定了利用制取生活热水的方式平衡地下释热量和吸热量的方案,并分析了这种方案的节能性。     

严寒地区太阳能土壤源热泵季节性土壤蓄热

针对严寒地区太阳能-土壤源热泵初期冬季土壤温度过低导致供热不达标、土壤热量以年为周期不平衡等问题,提出利用太阳能-土壤源热泵现有装置进行太阳能季节性土壤蓄热的解决方案。进行了冬季供暖、太阳能季节性土壤蓄热实验和夏季供冷实验。太阳能季节性土壤蓄热对于供暖和供冷都有利。土壤温度在蓄热结束时明显高于初始温度,土壤热量得到了有效补充。季节性蓄热能够使太阳能一土壤源热泵系统更充分利用太阳能,在严寒地区得到更好应用。     

地源热泵-燃气锅炉供暖系统的动态经济评价

针对燃气锅炉能源利用率偏低、废气排放多等问题,结合工程实际,利用经济分析的方法,对燃气锅炉供暖系统和地源热泵供暖系统分别从初投资、年运行费用、维护费用等方面进行分析。结果表明,地源热泵系统的初投资比较高,但由于运行费较低,根据费用年值及费用现值的计算,地源热泵系统在整个寿命期内的费用明显低于燃气锅炉供暖系统,因此,地源热泵系统比燃气锅炉系统具有更高的经济效益。     

Quo vadis source tracking? Towards a strategic framework for environmental monitoring of fecal pollution

Advances in microbial source tracking (MST) have largely been driven by the need to comply with water quality standards based on traditional indicator bacteria. Recently, a number of culture-independent, and library-independent methods based on polymerase chain reaction (PCR) have been gaining popularity among source trackers. However, only a limited number of these methods have been successfully used in field applications, primarily due to the fact that many of them are still being developed. In this critical outlook, we examine different viewpoints associated with the practical use of MST to identify critical research gaps, propose a priority-based timeline to address them, and outline emerging technologies that will likely impact the future of source tracking. We propose that it is necessary to consider each of these aspects in order to advance towards a unifying framework in source identification, so that fecal pollution monitoring can be reliably used for comprehensive environmental microbial monitoring, to develop risk assessment models, and to implement and validate adequate management practices.     

燃气专项规划中气源与负荷的确定

探讨了某县城燃气专项规划中气源和负荷的确定,认为气源应以管道天然气为主、瓶装LPG为辅,负荷的预测参照现状用气负荷和规划人口进行计算。     

Novel application of a statistical technique, Random Forests, in a bacterial source tracking study

In this study, data from bacterial source tracking (BST) analysis using antibiotic resistance profiles were examined using two statistical techniques, Random Forests (RF) and discriminant analysis (DA) to determine sources of fecal contamination of a Texas water body. Cow Trap and Cedar Lakes are potential oyster harvesting waters located in Brazoria County, Texas, that have been listed as impaired for bacteria on the 2004 Texas 303(d) list. Unknown source Escherichia coli were isolated from water samples collected in the study area during two sampling events. Isolates were confirmed as E. coli using carbon source utilization profiles and then analyzed via ARA, following the Kirby-Bauer disk diffusion method. Zone diameters from ARA profiles were analyzed with both DA and RF. Using a two-way classification (human vs nonhuman), both DA and RF categorized over 90% of the 299 unknown source isolates as a nonhuman source. The average rates of correct classification (ARCCs) for the library of 1172 isolates using DA and RF were 74.6% and 82.3%, respectively. ARCCs from RF ranged from 7.7 to 12.0% higher than those from DA. Rates of correct classification (RCCs) for individual sources classified with RF ranged from 23.2 to 0.2% higher than those of DA, with a mean difference of 9.0%. Additional evidence for the outperformance of DA by RF was found in the comparison of training and test set ARCCs and examination of specific disputed isolates; RF produced higher ARCCs (ranging from 8 to 13% higher) than DA for all 1000 trials (excluding the two-way classification, in which RF outperformed DA 999 out of 1000 times). This is of practical significance for analysis of bacterial source tracking data. Overall, based on both DA and RF results, migratory birds were found to be the source of the largest portion of the unknown E. coli isolates. This study is the first known published application of Random Forests in the field of BST.     

天然气气源问题的分析

分析了天然气气源项目概况、天然气资源与国际交易市场、国际国内天然气价格水平等问题.     

佛山市某化工厂污水源热泵的节能分析

本文以佛山市某化工厂应用污水源热泵为例,对常规冷水机组+燃气锅炉与污水源热泵机组两种系统方案进行了经济性及节能减排性比较分析。结果表明,与常规冷水机组+燃气锅炉系统相比,采用污水源热泵系统后,初投资成本增加了1.8万元,但每年的运行费用节省了25.4万元。一次能源利用率提高16%,每年可节省天然气约38658 m^3,节能及环保效应显著。     

LPG混空气作为天然气紧急备用气源的可行性

利用燃气互换性判别方法分析了液化石油气混空气作为天然气紧急备用气源的可行性,结合具体的燃具用实验加以验证,提出了紧急备用气源中液化石油气与空气合适的比例。     

V锥流量计和止回阀检漏在双气源计量的应用

提出了双气源供气条件下受限场所V锥流量计的应用及止回阀检漏的改造方案,为双气源供气计量结算提供了经验.