北京市燃气集团2005年燃气发展实现双突破

在刚刚过去的2005年，首都燃气发展实现双突破：天然气用量达30．8亿m^3,全市燃气居民用户总数408万户。2005年，北京市天然气购入量在2004年天然气购入量25．5亿m^3的基础上，猛增了5．3亿m^3，达到30．8亿m^3，使北京市城市天然气发展在持续7年，实现购入量在每年稳步增长3亿m^3的基础上，再创历年增长新高。     

北京成为全国最大的管道天然气化城市

北京市2010年天然气用量达到68．1×10^8m^3／a,与2009年相比,增加了7．5×10^8m^3／a,成为全国最大的管道天然气化城市。十一五期间,北京市天然气居民用户新增115×10^4户,     

新密市天然气利用工程正在施工中

新密市天然气利用工程由新密中燃燃气发展有限公司投资建设，一期工程建设LNG-CNG气化站1座、中压管网15km。站内设LNG-CNG撬装气化装置1套，20m^3LNG储罐1台，其最大处理气量为1500m^3／h，同时设置相应的消防、控制、电气、计量阀组、加臭等配套设施，可满足1．2万户居民用气，并为二期工     

浅谈户内及外网管线的安检管理办法

四平华生天然气有限公司始建于1991年7月，公司拥有固定资产3亿元．业务范围包括天然气供应及相关的燃气工程设计、施工、燃气技术咨询等领域。现日供气6．5万m^3，供应居民用户84344户，工商用户1043户．工业用户9户，建成长输管网64．5km．中、低压输配管网500．7km。     

北京怀柔雁栖湖工业开发区压缩天然气工程准备施工

工程内容：敷设中压天然气管道约17km，建设2座压缩天然气供应站，总供气能力为2500m^3／h，其中一座为1500m^3／h，另一座为1000m^3／h，供气工艺为撬装CNG拖车储气、两级换热、两级调压、计量、加臭，所需主要设备为撬装CNG调压柜2座及撬装高一中压调压柜1座。站厂占地面积约5000m^2。     

数字2006

18367．6万t，原油产量，比上年增长1．7％，585．5亿m^3，天然气产量，比上年增长19．2％，23．25亿t．煤炭产量（初步统计），3．06506亿t，原油加工量，同比增长6．3％，1．82048亿t。成品油产量，同比增长4．5％，     

北京市天然气用量居全国之首天然气居民用户突破300万户

截至2006年5月31日，今年北京市的天然气用量已达到17．8亿m^3,使用天然气的居民用户总数已经突破300万户。达到301．8万户。目前北京市天然气用量和天然气居民用户数量．都高于天然气用量较大的上海、天津、重庆等城市在全国占居首位。北京市燃气集团已成为全国最大的城市天然气运营商。过去北京市的燃气气源一直以人工煤气和液化石油气为主。     

城市燃气节能应用研究

我国城市燃气应用状况 在国家加快发展城市燃气和节能政策的指导下，城市燃气得到了很大的发展．我国天然气资源的开发、建设和利用．将使城市燃气进入一个新的发展时期。2000年．全国城市人工煤气供应总量152亿m^3；天然气供应总量82亿m^3．液化石油气供应总量1054万吨。我国城市燃气只能以居民生活炊事和少量热水供应为主．规模较小．用气人口中人工煤气占23％，液化石油气占63％，天然气占13％左右。     

天津国庆节安全供气2121万m^3

在天津市人民欢庆建国60周年大庆和中秋节8天长假期间．天津市燃气集团数千名职工坚守岗位．兢兢业业搞好节日期间生产服务工作．安全供应天然气2121．55万m^3．为保障全市居民节日生活做出了贡献。其中．7日天然气用量达到279．89万m^3．为8天黄金周单日最高供气量。     

2007年北京市燃气集团购入天然气39.3亿m^3创历史新高

北京市燃气集团天然气发展又创历史新高,全年天然气购入达到39．3亿m^3,在2006年35．3亿m^3的基础上净曾4亿m^3,并保持了自市燃气集团成立后天然气供应连续9年高速发展的态势。目前全市天然气用户总数达到342万,使北京市成为全国较大的天然气用气城市。     

Indoor carbon monoxide and PM2.5 concentrations by cooking fuels in Pakistan

Abstract Abstract In developing countries biomass combustion is a frequently used source of domestic energy and may cause indoor air pollution. Carbon monoxide (CO) and particulate matter with an aerodynamic diameter of 2.5 μm or less (PM_2.5) were measured in kitchens using wood or natural gas (NG) in a semi‐rural community in Pakistan. Daytime CO and PM_2.5 levels were measured for eight continuous hours in 51 wood and 44 NG users from December 2005 to April 2006. The laser photometer PM_2.5 (Dustrak, TSI) was calibrated for field conditions and PM_2.5 measurements were reduced by a factor of 2.77. CO was measured by an electrochemical monitor (Model T15v, Langan). The arithmetic mean for daytime CO concentration was 29.4 ppm in wood users; significantly higher than 7.5 ppm in NG users (P < 0.001). The arithmetic mean for daytime PM_2.5 concentrations was 2.74 mg/m³ in wood users; significantly higher than 0.38 mg/m³ in NG users (P < 0.001). Higher peak levels of CO and PM_2.5 were also observed in wood users. Time spent in the kitchen during fuel burning was significantly related to increasing CO and PM_2.5 concentrations in wood users. These findings suggest that cooking with wood fuel may lead to hazardous concentrations of CO and PM_2.5.     

Contribution of solid fuel, gas combustion, or tobacco smoke to indoor air pollutant concentrations in Irish and Scottish homes

There are limited data describing pollutant levels inside homes that burn solid fuel within developed country settings with most studies describing test conditions or the effect of interventions. This study recruited homes in Ireland and Scotland where open combustion processes take place. Open combustion was classified as coal, peat, or wood fuel burning, use of a gas cooker or stove, or where there is at least one resident smoker. Twenty-four-hour data on airborne concentrations of particulate matter<2.5 μm in size (PM2.5), carbon monoxide (CO), endotoxin in inhalable dust and carbon dioxide (CO2), together with 2-3 week averaged concentrations of nitrogen dioxide (NO2) were collected in 100 houses during the winter and spring of 2009-2010. The geometric mean of the 24-h time-weighted-average (TWA) PM2.5 concentration was highest in homes with resident smokers (99 μg/m3--much higher than the WHO 24-h guidance value of 25 μg/m3). Lower geometric mean 24-h TWA levels were found in homes that burned coal (7 μg/m3) or wood (6 μg/m3) and in homes with gas cookers (7 μg/m3). In peat-burning homes, the average 24-h PM2.5 level recorded was 11 μg/m3. Airborne endotoxin, CO, CO2, and NO2 concentrations were generally within indoor air quality guidance levels. PRACTICAL IMPLICATIONS: Little is known about indoor air quality (IAQ) in homes that burn solid or fossil-derived fuels in economically developed countries. Recent legislative changes have moved to improve IAQ at work and in enclosed public places, but there remains a real need to begin the process of quantifying the health burden that arises from indoor air pollution within domestic environments. This study demonstrates that homes in Scotland and Ireland that burn solid fuels or gas for heating and cooking have concentrations of air pollutants generally within guideline levels. Homes where combustion of cigarettes takes place have much poorer air quality.     

人工煤气转换成天然气后原燃气表检测误差

对在用 J4型家用膜式燃气表进行检测,分析了人工煤气转换成天然气后 J4型膜式燃气表的计量误差,对 J4型膜式燃气表的更换给出了建议。     

常低温下EGSB处理生活污水的影响因素研究

在15～26℃的常低温条件下,采用EGSB处理生活污水,考察了进水流量、回流比、液体上升流速(Vup)、温度等因素对运行效果的影响。结果表明,当温度为26℃左右时,对于9～11 L/h的低进水流量,宜采用高回流比(1.6～2.5),对COD的去除率最高可达90%;对于15～24L/h的高进水流量,宜采用低回流比(0～0.6),对COD的去除率最高可达84%;当进水流量提高至30 L/h时,不宜回流,对COD的去除率降至77%;当进水流量分别为9、11、15、24、30 L/h时,最佳Vup分别为4.0、(3.1～3.6)、(2.7～3.4)、3.0和3.8 m/h,此时对COD的去除率分别高达90%、(87%～89%)、(83%～84%)、83%和77%;在无回流的条件下,适宜的进水流量为15～24 L/h,相应的HRT为0.5～0.8 h。当温度为15～26℃时,EGSB适宜的运行条件是高进水流量(15～24L/h)、高Vup(3.0 m/h)和低回流比(0～0.6),此时对COD的去除率高达81.9%以上。     

On the reoxygenation efficiency of diffused air aeration

One technique used to increase the dissolved oxygen concentration of polluted waters is the bubbling of air through a diffuser pipe located at depth, thereby producing a bubble curtain from which oxygen transfer to the water occurs.

The results of laboratory studies on the aeration efficiency of a diffuser placed along the entire width of a flume, perpendicular to a cross flow are presented (two dimensional aeration). Parameters investigated include (1) diffuser type-porous materials with mean pore sizes of 40, 90 and 180 μm and perforated pipes with 0.4, 0.6 and 1.0 mm diameter ports (2) air flow rate per unit width 3–53 m³ (m h)⁻¹ and (3) cross flow velocity (2.5–15 cm s⁻¹. The effect of variation from the two dimensional situation is also discussed as well as the consequence of using oxygen instead of air, and the sensitivity to discharge angle, port spacing and the free surface. The measured efficiencies are compared with theory as well as available laboratory and field data.

The major conclusions are (1) aeration efficiencies using diffused air aeration are on the order of 2–13%m⁻¹ (2) the aeration efficiency increases with increasing cross flow velocity and decreasing air flow rate per unit width (3) aeration efficiencies using porous filters, for air flow rates less than 40 m³ (m h)⁻¹, are significantly higher (a factor of 2–3) than those achieved using perforated pipes (4) changing the pore size from 40 to 180 μm, the port size from 0.4 to 1.0 mm or the port spacing does not significantly effect the aeration efficiency (5) aeration using oxygen is somewhat less efficient than that using air. However, since equivalent oxygen bubbles contain approximately five times more oxygen than air bubbles, more oxygen is transferred on an absolute basis at the same gas flow rate using compressed oxygen as opposed to air (6) aeration efficiency resulting from aeration over a portion of the entire width can be reasonably predicted using the results of the two dimensional studies and (7) the available laboratory and field data compare well with the results of these laboratory studies.     

The adverse effects of fine particle air pollution on respiratory function in the elderly

There is increasing concern that airborne particles are critical risk factors for adverse health conditions in susceptible populations. The objective of this panel study is to investigate an association between particulate matter and the peak expiratory flow rate (PEFR) in the elderly and to compare estimated risks using PM10 or PM2.5 levels as a measure of exposure. During a 2-year longitudinal follow-up study, we contacted subjects living in an asylum for the elderly, provided them with a mini-Wright peak flow meter, and instructed to record all the flow readings, any respiratory symptoms, passive smoking activity, and hours spent outdoors for that given day. Daily levels of particulate matter were measured by two separate mini-volume air samplers (for PM10 and PM2.5) placed on the rooftop of the two-story residence asylum building. In our statistical models, we assumed that the expected response varied linearly for each participant with a slope and intercept that depended on fixed or time-varying covariates using a mixed linear model. The daily mean levels of PM10 and PM2.5 were 78 microg/m3 and 56 microg/m3, respectively. For every 10 microg/m3 increase in PM10 and PM2.5 levels, there was an estimated PEFR change of -0.39 l/min (95% CI, -0.63, -0.14) and -0.54 l/min (95% CI, -0.89, -0.19), respectively. These data also suggest that fine particles have a more adverse respiratory health impact for sensitive individuals such as the elderly and that more research and control strategies should focus on the smaller particles associated with air pollution.     

Quantifying measuring errors of new residential water meters considering different customer consumption patterns

Water meter measuring errors vary depending on the water flow rate. The difference between water actually consumed and registered by a meter will differ depending on how water consumption is distributed by flow rates. Published studies assessing the performance of new residential meters have only analysed the error curves of the meters – without calculating the influence that consumption patterns have on their field performance. In most cases, research has been limited to analysing compliance with published standards. This work presents an evaluation of the actual commercial losses to be expected considering the consumption characteristic of domestic users. Several types of residential meters have been tested and the error curves obtained have been combined with measured consumption patterns of domestic users. As a result, this paper provides information about the order of magnitude of the initial measuring error as a function of the residential meter model and user characteristics.     

涡轮流量计计量稳定性影响成因分析

分析前置导流体出流速度对涡轮流量计计量精度影响成因,在流量测量范围内对某型号涡轮流量计前置导流体流道内的速度分布进行模拟。叶轮角速度与气体流入叶轮绝对流速成正相关,由于叶轮角速度直接影响涡轮流量计计量稳定性,因此研究前置导流体流道内的速度分布能为提高涡轮流量计计量稳定性提供理论依据。流道内空气流速随着流量的增大而增大,且最大流速区随流量的增大向前置导流体中心线偏移。空气流量8、32、64、160 m3/h对应的最大流速区的最大流速分别为0.86、3.61、7.37、18.92 m/s。     

Polycyclic and nitro musks in indoor air: a primary school classroom and a women's sport center

Indoor air gas and particulate-phase samples (PM(2.5) ) were collected from a primary school classroom and a women's sport center because children are one of the sensitive population subgroups and women are frequent users of personal care products in addition to the high level of activity in this specific microenvironment. PM(2.5) was collected with a Harvard impactor, and polyurethane foam was used for the gas phase. Samples were ultrasonically extracted, concentrated, and analyzed with a GC-MS. The mean gas-phase concentrations in the classroom ranged from 0.12 ± 0.2 ng/m(3) for MK to 267 ± 56?ng/m(3) for HHCB, while it was from 0.08 ± 0.10 ng/m(3) for AHMI to 144 ± 61 ng/m(3) for HHCB in the sports center. Particulate-phase average concentrations in the sports center ranged from 0.22 ± 0.11 ng/m(3) for ATII to 1.34 ± 071 ng/m(3) for AHTN, while it ranged from 0.05 ± 0.02 ng/m(3) (musk xylene) to 2.50 ± 0.94 ng/m(3) (HHCB) in the classroom. Exposure-risk assessment showed that inhalation route is most probably far less significant than the dermal route; however, it should be noted that the exposure duration covered in this study was not the larger fraction of the day. PRACTICAL IMPLICATIONS: Synthetic musk compounds (SMCs) are found everywhere because their use in household and personal care products (laundry detergents, carpet cleaners, cleaning agents, fabric softener soaps, shampoos, cosmetics, etc.) has been increasing. These compounds are semi-volatiles that may result in direct and indirect exposures through inhalation route. Although SMCs were found to be dominant in the gas phase, exposure via inhalable particles may be important as we found several compounds in the particulate phase (PM(2.5)).     

Characterization of two-phase flow in a single rock joint

An experimental study using a triaxial apparatus was used to analyze the two-phase flow patterns in jointed rock specimens. Rock specimens having a single natural fracture were tested for two-phase flow of water and air. Triaxial tests were conducted to characterize the two-phase flow through fractured granite specimens at low confining pressures. It was found that for a relatively smooth joint (JRC<6), bubble flow pattern occurred within the rock joint when the gas velocity is below 15 m/s. The average velocity of water usually varied between 0.1 and 0.5 m/s for bubble flow patterns. In this velocity range, air bubbles were able to form along the joint walls or to be randomly displaced within the water phase. When the gas velocity inside the rock joint exceeded 22 m/s, the flow patterns took annular form for non-zero capillary pressures (i.e., injected gas pressure is not equal to injected water pressure). At elevated (>0.25 MPa) gas injection pressures, the gas occupied the main part of the fracture and the liquid was able to flow as an unstable film forming an annular flow along the joint. When the annular flow developed, the mixture flow pattern was independent of the air flow velocity. This was due to the fact that once the injected air velocity reached a critical value (i.e., 20 m/s), water velocity inside the joint was negligible for a given confining pressure and injected water pressure. Further increase in inlet air pressures developed a single-phase air flow with no water flow.