Relationship between Formation Water Rate,Equivalent Penetration Rate and Volume Flow Rate of Air in Air Drilling

Formation water invasion is the most troublesome problem associated with air drilling. However, it is not economical to apply mist drilling when only a small amount of water flows into wellbore from formation during air drilling. Formation water could be circulated out of the wellbore through increasing the gas injection rate. In this paper, the Angel model was modified by introducing Nikurade friction factor for the flow in coarse open holes and translating formation water rate into equivalent penetration rate. Thus the distribution of annular pressure and the relationship between minimum air injection rate and formation water rate were obtained. Real data verification indicated that the modified model is more accurate than the Angel model and can provide useful information for air drilling.

Study on the Relationship between the Oceanic Nino Index and Surface Air Temperature and Precipitation Rate over the Kingdom of Saudi Arabia

Abnormal weather conditions and extreme weather existed over the Kingdom Saudi Arabia (KSA) through the last decades. The present paper investigates the relationship between the Oceanic Nino Index (ONI) and variability of surface air temperature and precipitation rate over KSA through the period from 1950 to 2015 year. The NCEP/NCAR Reanalysis of monthly data sets of the mean surface air temperature and precipitation rate for the domain of the KSA is used. In addition, El Nino3.4 monthly data through the period (1950-2015) are used. For that period, the data set of the three months moving average of Nino3.4 anomaly, Oceanic Nino index (ONI), is used and analyzed. The time series, anomaly and correlation coefficient techniques are used to analyze the data sets through the present study. The results revealed that the KSA climate parameters, temperature and precipitation rates are controlled by ONI mainly in the autumn and winter seasons.

Measurement of air kerma rate and ambient dose equivalent rate using the G(E) function with hemispherical CdZnTe detector

Since the room-temperature detector CdZnTe(CZT) has advantages in terms of detection efficiency,energy resolution, and size, it has been extensively used to detect X-rays and gamma-rays. So far, nuclear radiation detectors such as cerium chloride doped with lanthanum bromide(LaBr_3(Ce)), thallium doped with cesium iodide(sI(Tl)), thallium doped with sodium iodide(NaI(Tl)),and high-purity germanium(HPGe) primarily use the spectroscopy-dose rate function(G(E)) to achieve the accurate measurement of air kerma rate(K_a) and ambient dose equivalent rate(H*(10)). However, the spectroscopy-dose rate function has been rarely measured for a CZT detector. In this study, we performed spectrum measurement using a hemispherical CZT detector in a radiation protection standards laboratory. The spectroscopy-dose rate function G(E) of the CZT detector was calculated using the least-squares method combined with the standard dose rate at the measurement position. The results showed that the hemispherical CZT detector could complete the measurement of air kerma rate(K_a) and ambient dose equivalent rate(H*(10)) by using the G(E) function at energies between 48 keV and 1.25 MeV, and the relative intrinsic errors were, respectively, controlled within ± 2. 3 and ± 2. 1%.

Improvement of uniformity in cultivation environment and crop growth rate by hybrid control of air flow devices

A complete control type plant factory has high efficiency in terms of cultivation area by constructing vertical multiple layered cultivation beds.However,it has a problem of irregular crop growth due to temperature deviation at upper and lower beds and increases in energy consumption by a prolonged cultivation period.In this work,air flow rate inside a facility was improved by a hybrid control of air flow devices like air conditioning and air circulation fan with an established wireless sensor network to minimize temperature deviations between upper and lower beds and to promote crop growth.The performance of proposed system was verified with an experimental environment or Case A wherein air conditioning device was operated without a control algorithm and Case B wherein air conditioning and circulation fans were alternatively operated based on the hybrid control algorithm.After planting leafy vegetables under each experimental condition,crops were cultivated for 21 days.As a result,Case B wherein AC(air conditioning) and ACF(air-circulation fan) were alternatively operated based on the hybrid control algorithm showed that fresh mass,number of leaves,and leaf length for the crops grown were increased by 40.6%,41.1%,and 11.1%,respectively,compared to Case A.

Influence of Air Flow Rate on Functional Evaluation of Semicircular Canals

Objective To study the influence of unilateral air flow rate change on the result of caloric test.Materials and Methods The unilateral weakness(UW) index was calculated when the air flow rate was set at 6 L /min in both ears(called symmetric stimulation) and again when it was set at 6 L /min in left ear and 3 L /min in the right ear(called asymmetric stimulation).Each individual subject was tested with both symmetrical and asymmetrical stimulations.Paired t test was used to examine the differences between results from symmetrical and asymmetrical stimulations.Result UW index decreased in response to asymmetrical stimulation.Conclusion Unilaterally decreased air flow rate can produce indices suggesting ipsilateral UW,which can be misleading.

Study on the Relationship of Spray Rate to Air Pressure and Gravity Drop of Siphonic Nozzle

In order to further clarify the spraying performance of siphonic nozzle, the spray rate of siponic cone nozzle with aperture of 1.0 mm was determined at 15 different air pressure levels and 12 gravity drop levels, and DPS and SPSS were used to make the difference analysis and modeling, which clarified the relationship between the spray rate of the siphonic cone nozzle with aperture of 1.0 mm and air pressure and gravity drop, getting the regression equation of Y=406.854P＋ 1.904G＋77.524. The study could provide a theoretical basis for the optimization and improvement of plant protection spraying equipment.

Air pressure law of a reservoir constructed in karst sinkholes

Karst sinkholes with natural negative landform provide favorable conditions for the pumped storage reservoir construction for less excavation work.However,the construction of the reservoir would plug the natural karst channels for water and air,which would cause remarkable air pressure in karst channels when the groundwater level fluctuates.A large laboratory simulation test was carried out to study the air pressure variation of a reservoir built on the karst sinkhole.The air pressure in the karst channel and inside the model was monitored during the groundwater rising and falling process.Result showed that the variation of air pressure in the karst channel and the surrounding rock exhibited a high degree of similarity.The air pressure increased rapidly at the initial stage of water level rising,followed by a slight decrease,then the air pressure increased sharply when the water level approached the top of the karst cave.The initial peak of air pressure and the final peak of air pressure were defined,and both air pressure peaks were linearly increasing with the water level rising rate.The negative air pressure was also analyzed during the drainage process,which was linearly correlated with the water level falling rate.The causes of air pressure variation in karst channels of a pumped storage reservoir built on the karst sinkhole were discussed.The initial rapid increase,then slight decrease and final sudden increase of air pressure were controlled by the combined effects of air compression in karst channel and air seepage into the surrounding rock.For the drainage process,the instant negative air pressure and gradual recovering of air pressure were controlled by the combined effects of negative air pressure induced by water level falling and air supply from surrounding rock.This work could provide valuable reference for the reservoir construction in karst area.

The Comparison of Measurement Methods for Air-Kerma Rate in Narrow-Spectrum Series

The air-kerma is one of the most important physical quantities in ionizing radiation dosimetry. The measurement of airkerma rate in narrow-spectrum series is the basis to determine the radiation dose at protection level. In this article, the absolute measurement method is used to derive the standard air-kerma rate of the ISO 4037 narrow-spectrum series that ranges from 60 kV to 150 kV by a primary standard ionization chamber,it is used in direct comparison for air kerma. The indirect method is used to obtain the air-kerma rate by a secondary standard transfer ionization chamber named A5 chamber with calibration factors of the corresponding reference qualities. The results are very similar comparing between absolute and indirect methods for air-kerma rate, all the differences are within ±3.3%.

新型深井立式车库通风设计优化

针对深井立式车库与普通车库相比存在无人员驾驶车辆进出、无污染物排放等特点,探究了新型的适用于深井立式车库的通风设计原则,以满足安全通风要求。首先提出了2种通风设计原则(常规车库CO释放量、深井立式车库非火灾事故检修通风)及判定标准;然后以某深井立式车库为原型,通过数值模拟分别确定了2种通风设计原则情况下的最佳通风换气次数,并探究了以常规车库CO释放量为设计原则情况下燃油车占比对换气次数的影响。结果表明:以常规车库CO释放量为原则通风,当深井立式车库内全部为燃油车时,车库最佳通风换气次数为3 h^(-1);当深井立式车库内满足通风换气次数为2、1、0 h^(-1)时,车库内燃油车占比分别为70%、50%、40%。以非火灾事故检修通风为原则通风时,深井立式车库内最佳通风换气次数为4 h^(-1)。

节能技术助力实验动物设施环境控制与绿色低碳

在现场调研、检测北京、上海10多家实验动物设施环境控制及能耗水平的基础上,研究了实验动物设施净化空调系统的排风热回收、降低换气次数冗余度、新风集中+室内自循环净化机系统的昼夜不同运行模式,以及多功能四管制热泵冷凝热用于除湿再热和其他清洗用热等节能技术,并应用于北京、上海的2个典型实验动物中心,通过实时能耗监控平台的全年运行数据可知,全年节能率均超过30%。结果表明,该节能技术有效适用于实验动物设施,对实验动物设施的节能降耗提供了技术支撑,有助于在新建、改扩建实验动物设施中的推广与应用。

徐州地区公共建筑能效测评数据研究

针对徐州地区近十年来公共建筑能效测评数据进行了研究。主要研究了公共建筑节能设计标准的变化、建筑外围护结构保温材料的种类及热工性能、集中空调系统冷热源的类型及其制冷性能、建筑能耗强度及节能率的逐年分布。研究表明,开展能效测评工作,促进了外围护结构热工性能及集中空调系统冷热源制冷性能的提高,建筑能耗强度不断降低,建筑节能水平提升,可助力建筑“双碳”目标实现。

NUMERICAL RESEARCH ON IMPACT OF AIR SYSTEM BLEEDING ON COMPRESSOR PERFORMANCE

Bled air from the high pressure compressor takes up 3%—5% in the air system.However,there are not many studies on the compressor performance after bleeding.By analyzing the low-speed single-stage compressors,six bleeding structures are presented according to their influence mechanism on the compressor performance,and five kinds of bleeding rate are applied to one of the structures.A numerical simulation is performed to study the influence of bleeding rates and structures on the compressor performance.The results show that for the stators with the large flow separation in the corner,bleeding a small amount of air from the end-wall region can improve the total pressure increase and the stability margin.Moreover there is an optimum value of the bleeding rate in the stator casing.

吸风量对不同性质物料清粉效果的影响

以粗麦渣、粗麦心、细麦心3种物料作为原料,使用清粉机清粉,通过调节吸风量来研究吸风量对不同性质物料清粉效果的影响。结果表明:随着吸风量增加,粗麦渣物料筛出率先明显增加后明显减小,灰分降低率先显著增加后显著减小,清粉效率先显著增加后明显减小;粗麦心物料筛出率先明显增加后明显减小,灰分降低率先增加后降低,清粉效率先增加后减小,两种指标变化趋势并不显著;细麦心物料筛出率降低,灰分降低率增加,清粉效率先增加后减小,3项指标变化趋势均不显著。粗麦渣物料在吸风量2114~2509 m^(3)/h时、粗麦心物料在吸风量1978~2154 m^(3)/h时、细麦心在吸风量881~1041 m^(3)/h时有较好的清粉效果。3种物料分级效果从好到差依次为粗麦渣、粗麦心、细麦心。

热泵驱动型加湿-除湿废液处理系统的性能

基于加湿-除湿原理搭建了废液处理实验台,并利用热泵为系统同时提供热源和冷源。通过调节循环风机及溶液泵频率(25~50 Hz),着重研究了循环风量和废液流量对填料传热传质特性及废液处理性能参数的影响。结果表明,废液的初始pH、SS、COD分别为13.51、166 mg/L、2117 mg/L,系统分离出的清液pH、SS、COD分别为8.2、4.0 mg/L、53.2 mg/L,水质得到极大改善。填料传热传质系数随循环风量和空气侧雷诺数的增加而升高,净水产量(PWPA)、净水回收率(PWRR)也随循环风量的增加而升高,填料的增益输出比(GOR)随循环风量的增加先升高后降低。填料传热传质系数随废液流量和废液侧雷诺数的增加而升高,PWPA也随废液流量的增加而升高,但PWRR随废液流量的增加而降低,GOR随废液流量的增加先逐步提高,然后几乎保持不变。由于不同性能参数受循环风量和废液流量的影响规律并不一致,需根据优先考虑的性能参数选择合适的循环风量和废液流量。

液态空气储能系统的液化技术分析与展望

可再生能源的间歇性和波动性等特性给电网调度带来了挑战。液态空气储能系统不仅规模大、储能时间长,而且具有储能密度高、不受地理环境限制等特性,是解决这一问题的有效技术措施之一。首先,介绍了5种经典的空气液化循环技术的原理,分析了不同液化技术在空气液化方面的特点。然后,分析了2种空气液化循环的改进技术,比较了不同的空气液化技术在液化能力、经济性等方面的优势与不足。综述认为,如果综合考虑液化率、经济成本和安全性,应尽量采用Linde-Hampson循环和Claude循环。最后,分析了现有的空气液化技术在液化率、冷量缺口等方面存在的问题,探讨了液态空气储能系统空气液化技术的未来发展趋势。

煤粉掺氢燃烧技术试验研究

为研究煤粉掺氢燃烧技术作为减少煤燃烧碳排放的路径选项,关注其燃烧及NO排放特性,以及空气分级燃烧模式对NO排放的控制效果,在1台可实现煤粉自持燃烧的50 k W下行燃烧试验炉上进行煤粉掺氢燃烧试验,选用神府烟煤作为试验煤种,分别在不同掺氢比例和空气分级程度下,探究了NO生成量、主燃烧区温度变化以及燃烧沿程排放产物的情况。结果表明,掺氢在降碳的同时,并不会引起NO排放增加,当掺氢比例为50%时,NO的排放质量浓度下降达到27.55%。在高燃尽风率下此效果更为显著,燃煤掺氢在燃尽风率从39%提高至50%后,NO排放的降幅高达30%。煤粉掺氢燃烧技术在减少煤燃烧碳排放方面具有潜在的应用前景,可为燃煤电厂CO_(2)减排提供一种可行的技术路径选项。

Influence of environmental conditions on airborne infection risk in ward

In order to study the influence of parameters on airborne transmitted diseases in a hospital ward,a pollutant decay equation and a Wells-Riley model are adopted to study the relationship between the airborne infection risk and the parameters such as the ventilation rate,the number of susceptible persons and the volume of the ward.The results show that the airborne infection risk can be reduced by increasing the ventilation rate.For two wards with the same air change per hour（ACH）but different volumes,the ventilation rate in a large room is higher than that in a small one.The number of the infected persons in the ward increases with the increase in the susceptible persons when the ACH is a constant.Therefore,the ventilation rate in the ward is not only estimated by the ACH but also related to the volume of the ward and the number of the susceptible persons.

Effect of Air Injector on the Performance of an Air-lift for Conveying River Sand

An air-lift has been more recently applied in the dredging, deep-seated beach placer mining and underground mining engineering. However, the influence and mechanism of various parameters on the air-lift performance are not quite clear, especially the influence of flow pattern on lifting efficiency. Focusing on the problems mentioned above, the key part of the air-lift （namely, the air injector） was proposed aimed to reduce friction loss in the inner pipe according to improving flow field performance, thus increase the lifting efficiency. The study of relative factors of the performance of an air-lift is performed and the river sand is used as simulation of underground ore bed. The total lifting height of the experimental system is 3 m, the water flux, mass flow of solid particles, concentration of particles and lifting efficiency are measured under the same submergence ratios by changing the air injector, which is divided into nine specifications of air injection in this research. The experimental results indicate that the optimal air flow rate corresponding to excellent performance of the air-lift can be obtained in the range of 35-40 m3/h. The air injection method has a great effect on the performance of the air-lift, the air injector with three nozzles is better than that in the case of one or two nozzles. Further more, the air injection angle and arrangement of air injection pipes also have great effect on the performance of an air-lift. The proposed research results have guiding significance for engineering application.

Study on NOx Formation in CH4/Air Jet Combustion

With the development of reaction kinetics and transfer science, the modeling of NOx formation plays more and more important roles in the protection of environment and the design of combustion reactors; in this case,turbulence-chemistry model and NOx formation model are the two most important aspects. For thermal NOx mechanism, this article studied the CH4/air system and applied a set of latest NO formation rate constants published at the Leed University which replaced the original model code in FLUENT to increase its precision on prediction of NO concentration. The realizable k-ε model, Reynold Stress model and standard k-ε model were also investigated to predict the turbulent combustion reaction, which indicated that the simulation results of velocities, temperatures and concentrations of combustion productions by the standard k-ε model were in good accordance with the experimental data. With the application of the simulation results to the experimental data to fit some important kinetic parameters in the equation of O atom model and revision of the equation later, this article obtained a new NO formation rate model. It has been proved that the prediction of the developed model coincides well with the measurements.

DZ3型空气捻接器应用实践

为了提高纱线捻接质量,以DZ3型空气捻接器为例,介绍其工作原理及衡量捻接质量的4个指标,即捻接失败率、电清捻接粗节和细节的100 km切疵数、捻接强力和捻接外观;从调整捻接工艺参数、做好空气捻接器维护工作及关注捻接指标等方面,提出稳定捻接质量的措施,并针对不同种类纱线结构特点进行捻接工艺参数优选试验。指出:用好空气捻接器是保障纱线捻接质量的关键;捻接工艺参数设置对捻接质量、络筒效率影响较大,应根据原料、纺纱品种、车间温湿度变化等及时调整。