基于低油价下一种低成本储层钻井新技术

采用氮气作为钻井循环介质能有效保护油气储层,但氮气设备成本较高,限制了氮气钻井的推广应用。针对这些问题和氮气钻井的特点,探索基于低油价形势下,给出现场采用技术套管作为氮气储存容器的新技术,通过测算每口井可节省2×10~4m~3氮气,降低氮气钻井的设备成本150万元,为氮气钻井在中浅层储层大面积推广应用提供技术支持。     

输气管线氮气置换分析

以重庆市西彭至永川天然气输气管线三标段工程全程氮气置换为例,对从如何选择置换方式、氮气置换设备的选择、置换对氮气的要求及氮气量的计算、氮气置换过程等几个方面进行分析,对输气管线如何进行氮气置换进行分析总结。     

城镇燃气行业制备氮气的技术经济性分析

简述膜分离制氮、碳分子筛制氮、液氮气化制氮及瓶装高压氮气充装4种制备氮气方法的原理和流程,分析4种制备氮气方法的经济性和适用性,得出了在不同用氮气量的条件下各方法的单位气体综合成本.     

氮气在七氟丙烷中的溶解度测定及计算

为研究氮气在七氟丙烷内的溶解度,利用PVT实验装置测定了在不同温度和压力下氮气在七氟丙烷内的溶解度,并系统讨论了温度、压力对溶解度及亨利系数的影响,结合实验数据,建立了氮气在七氟丙烷内的溶解模型。研究表明,温度有利于氮气在七氟丙烷中的溶解;压力不利于氮气在七氟丙烷中的溶解;氮气在七氟丙烷中的溶解模型拟合数据效果较高,最大偏差未超过3%。     

氮气灭火系统分析

氮气灭火系统是向防护区内释放纯氮气,将防护区内的氧气体积分数降低到物质持续燃烧所必须的体积分数 (15％)以下而达到灭火目的的新一代灭火系统。氮气对臭氧层破坏系数(ODP值)为0,地球温暖化系数为0,是对人安全、对地球生态环境没有污染的环保产品。空气中所含氮气的比例为 78％,灭火剂使用纯氮气,降低了灭火剂的充装使用成本。     

氮气置换技术在液化石油气槽车事故处置中的应用

介绍了氮气置换装置的组成、操作方法以及使用氮气置换技术应注意的问题,并结合具体案例分析了氮气置换技术在处置液化石油气槽车事故倒罐应用中的优越性。     

天然气管道或储罐停产置换方案的探讨

根据甲烷与氮气混合气体在空气中的爆炸范围,制订天然气管道停产置换的操作流程,进而确定置换过程的氮气用量,以确保氮气用量既满足安全性,又符合经济性。     

中浅层氮气钻井可混空气量临界值计算模型及应用

由于氮气钻井需要制氮设备造成钻井成本高,在不发生燃爆的前提下,应用可混空气临界浓度计算模型和编制的计算软件计算确定了可混入空气的气量临界值,并优化配置了中浅层储层氮气钻井配套设备,减少氮气设备的使用。通过现场4口井的应用,节约柴油8.8 t,有效降低成本,为氮气钻井的经济应用提供了依据。     

移动制氮灭火装备在灭火救援实战中的设计应用

针对氮气灭火剂因投送方式单一且补给困难的行业痛点,提出了集制氮、储氮、供氮、输氮、保氮、联氮等功能于一体的移动式氮气灭火装置的设计理念和集成工艺,并将设计的移动式氮气灭火装置应用于大跨度举高喷射消防车。移动式氮气灭火装置兼具水、泡沫、粉剂、压缩氮气泡沫、氮气等灭火功能,可充分发挥“工艺处置与消防处置相结合”和“固/气和液/气灭火协同”的技战术,适用于消防水源不足和水灭火剂不适用场景的灭火救援需求。移动制氮灭火装备的研制和应用可为各类化工及特殊火灾事故的救援提供消防装备保障和灭火技战术支撑。     

氮气灭火系统对受限空间木垛火的窒息特性研究

氮气灭火系统因其环保节能、稳定性高等特点,在建筑消防领域展现出巨大的发展空间。为进一步拓宽氮气灭火系统的应用领域,通过缩尺寸模型实验分析了氮气灭火系统对受限空间木垛火的灭火时间、氧气浓度、火焰温度等窒息特性参数的影响。结果表明,氮气灭火系统对受限空间中木垛火展现了良好的窒息灭火效果,其中不同火源功率的木垛火在受限空间中的灭火时间接近。     

Development of physicochemical nitrogen removal process for high strength industrial wastewater

The biological nitrogen removal (BNR) process is the most common method for removing low quantities of ammonium from wastewater, but this method is not used for wastewater rich with ammonium. In this study, we have developed the physicochemical nitrogen removal process to remove the nitrogen content for a real industrial wastewater. The denitrification was accomplished by the physicochemical denitrification process using zinc powder and sulfamic acid in pH 2-4. The experimental parameters were examined by varying various reaction conditions such as pH, zinc feeding time, amount of sulfamic acid, and amount of nitrate concentration. For each experimental condition, the physicochemical denitrification process was determined by pH, amount of zinc powder and sulfamic acid, zinc feeding time and nitrate concentration.     

上海LNG液氮储罐控制原理及改造

在我国有很多小型化工厂,日常使用氮气量不大,所以大都没有设置专业生产氮气的装置,一般采用设置液氮储罐和环境气化器的方式,通过外购液氮存储,再气化后供各设备使用。文章以上海液化天然气有限责任公司的液氮存储和气化工艺为例,介绍液氮存储及其控制原理,在使用中存在较普遍问题及解决办法。     

Improving the nitrogen removal efficiency of an A2/O based WWTP by using an on-line knowledge based expert system

The results obtained using an expert system to control an activated sludge process involving nutrient removal are reported. The study was conducted at a pilot plant using an Anaerobic/Anoxic/Oxic (A2/O) scheme for which a distributed control system was specially developed. The system allows various expert operational approaches to be developed with a view to minimize nitrogen levels in the outlet while using the minimum amount of energy. The proposed distributed control system is supervised by a Knowledge Based Expert System (KBES) constructed with G2 (a tool for expert system development) and permits the on-line implementation of every operating strategy of the experimental system. A set of experiments involving variable loads and flow-rates was carried out. It revealed that the amount of removed nitrogen could be increased by 11% compared to the usual operating conditions. This increase resulted in a decrease in the amount of total nitrogen and ammonium nitrogen in the outlet by 49% and 64%, respectively. These improvements were achieved with little energy cost because the performance of the treatment plant was optimised using operating rules implemented in real time.     

进水氨氮对厌氧同步脱氮除硫工艺的影响

通过比较含氨氮和不含氨氮两种进水水质条件下接种物不同的两个反应器的脱氮除硫特性,研究进水氨氮对厌氧同步脱氮除硫性能的影响。结果表明,进水未加氨氮的反应器对硫化物和硝态氮的去除率均高达95%,当加入氨氮后,仅有40%～50%的硝态氮被去除,消耗1 g硫化物所还原的硝态氮量减少,去除硝态氮的能力降低了近50%,然而对硫化物的去除率仍维持在90%左右,表明脱氮过程比脱硫过程受进水氨氮的影响大。扫描电镜观察结果证实,当进水中存在氨氮时硫化物的毒性增大,杀死了大量的脱氮硫杆菌,降低了硫化物转化为单质硫的能力,干扰了系统的反硝化脱氮过程,这是导致体系脱氮能力降低的主要原因。     

HA-A/A-MCO工艺水解酸化单元运行性能研究

针对现有污泥减量技术中存在的氮、磷去除率低的问题,开发了一个新型的具有同步除磷脱氮和污泥减量功能的HA-A/A-MCO工艺,对回流污泥种类及比例对水解酸化池产酸、污泥减量及系统释磷效果进行研究,结果发现：回流污泥种类及比例影响水解酸化出水VFA总量进而影响释磷效果,回流2%厌氧释磷污泥水解产生的VFA总量最大（275 mg/L）,系统释磷量也最大（57 mg/L）。     

Long-term changes in pollutant load outflows and purification function in a paddy field watershed using a circular irrigation system

A long-term investigation on the water quality and hydrology was carried out for 8 years and 7 months (from October 1991 to April 2000) in a paddy field watershed using a circular irrigation system. The annual amount of rainfall ranged from 1270 to 2226 mm and it was found that the amount of irrigation water tended to decrease as rainfall increased. Phosphorus and chemical oxygen demand (COD) concentrations tended to decrease with the river flowing down, whereas nitrogen concentrations showed no significant difference. The annual outflow loads (sum of the net-outflow load during irrigation periods and the outflow load during non-irrigation periods) of total nitrogen (T-N), total phosphorus (T-P), and COD ranged from 13.6 to 75.3 kg ha(-1)yr(-1), -3.55 to 2.21 kg ha(-1)yr(-1), and -24.7 to 48.5 kg ha(-1)yr(-1), respectively. The negative values for T-P and COD loads indicated that the study watershed performed a purification function. The change in annual pollutant loads was primarily attributed to the amount of hydrological water volumes (the annual amount of rainfall or that of rainfall plus irrigation water) for T-N and COD loads and partially for T-P load. In addition, the purification function was related to the hydraulic retention time, and the study watershed allows sufficient retention for pollutant purification for phosphorus and COD contents and partially for nitrogen content.     

污泥减量化工艺:HA-A/A-MCO的除磷性能及磷回收

针对污泥减量技术中对氮、磷去除能力低的问题,开发了一种具有强化脱氮除磷功能、污泥减量化的HA-A/A-MCO工艺,其通过回流释磷污泥的水解酸化来刺激磷的厌氧释放并辅以外排富磷污水进行化学固定的方式除磷.研究发现:当进入水解酸化池的厌氧释磷污泥量为进水量的2%时,水解产生的VFA导致释磷量达57 mg/L,聚磷菌的生长得到促进而聚糖菌则受到抑制;当控制侧流除磷液量为进水量的13%、化学除磷池出水磷为5 mg/L时,系统处理出水TP<0.5 mg/L;提高厌氧释磷浓度并控制化学除磷池的出水磷浓度为5 mg/L,可以提高化学药剂利用率、减少药剂用量并提高化学污泥的含磷量,HA-A/A-MCO系统产生的化学污泥含磷率高达18%,接近纯含磷化合物的含磷率,可直接用作生产磷肥的原料.     

On the peroxodisulphate oxidation of total nitrogen in waters to nitrate

The method proposed by Koroleff of oxidizing total nitrogen in natural waters to nitrate by means of peroxodisulphate in alkaline medium at 120°C is studied in some detail applying earlier experiences concerning the reduction of nitrate by cadmium and the determination of nitrite formed as an azo dye. The choice of the proper concentrations of peroxodisulphate and sodium hydroxide for the digestion is critically discussed as well as the choice of the proper pH and buffer system for the reduction. As a result a new reagent is proposed whose concentrations of peroxodisulphate and sodium hydroxide are founded on the stoichiometric relations at the autodecomposition of the peroxodisulphate; the proper pH of 8.0 for the reduction is achieved by addition of the calculated amount of Tris(hydroximethyl)aminomethane hydrochloride. A method for the preparation of potassium peroxodisulphate of a very low nitrogen blank is given. The digestion is performed at 100° or at 120°C. The requisite digestion time, a function of the autodecomposition of the peroxodisulphate, is found to be 90 min at 100°C and 15 min at 120°C. The yields obtained by oxidation of various nitrogen compounds are studied. The same yields are obtained at both temperatures but are dependent on the form of the nitrogen linkage. Thus, for example, nitrate, nitrite, ammonia and urea give a yield of >99%, the yield for some aliphatic amino acids varies from 92 to >99% and the yield for some proteins from 92 to 95% while a double bond between nitrogen atoms seems entirely to prevent their oxidation to nitrate. The requisite excess of peroxodisulphate is dependent not only on the amount of nitrogen in the sample but rather on the total amount of oxidizable substances, primarily organic matter; the COD of the sample portion should not appreciably exceed 10% of the oxygen available from the peroxodisulphate. A study of the concentration dependence at constant ratio reagent to nitrogen compound shows that the yield as a rule decreases with increasing dilution (exceptions are glycine and ammonia) thus often preventing the use of large sample volumes at low nitrogen content in order to increase the accuracy. Aspects on the practical use of the method are presented together with some illustrations, also including its application on sea water which can be analyzed by the method if only care is taken to keep up the hydroxide ion concentration which is lowered by precipitation of magnesium hydroxide. The expected precision and accuracy are discussed. While the precision by analysis of clear waters of not too low nitrogen content need not be poorer than 1%, the accuracy will be dependent on the nature of the nitrogen compounds and their relative concentrations and a negative error varying from 0 to 8%, all according to these circumstances, seems probable.     

Nitrogen gas supersaturation in the recent sediments of lake erie and two polluted harbors

Nitrogen gas distributions in sediment pore water were determined for cores collected in Lake Erie and two nearby harbors. Concentrations of N₂ gas ranged from 11.9 to 37.0 ml l⁻¹ and from 8.9 to 58.3 ml l⁻¹ for open lake and polluted harbor sediments, respectively. Maximum concentrations in the harbor sediments were as high as 3.5 times N₂ saturation calculated for the overlying water. Indirect diffusive flux estimates for nitrogen gas ranged from 20 to 32% of the particulate nitrogen sedimentation rate in Lake Erie. At one location, the amount of nitrogen gas lost by diffusion was calculated to be greater than the nitrogen deposited to the sediments. Nitrogen gas production and diffusive loss from surficial sediments probably represents a major pathway for nitrogen removal from Lake Erie.     

液氮灭火装置灭火性能实验分析

以液氮作为灭火剂，对A类、B类和深位火灾进行了灭火实验，并与其它灭火剂在灭火时间和使用量方面进行比较。