• <tr id="yyy80"></tr>
  • <sup id="yyy80"></sup>
  • <tfoot id="yyy80"><noscript id="yyy80"></noscript></tfoot>
  • 99热精品在线国产_美女午夜性视频免费_国产精品国产高清国产av_av欧美777_自拍偷自拍亚洲精品老妇_亚洲熟女精品中文字幕_www日本黄色视频网_国产精品野战在线观看 ?

    Abstracts and Key Words

    2020-02-26 12:50:53
    煤氣與熱力 2020年4期
    關鍵詞:玩玩氣力孫思邈

    Heat-supplyNetwork,Cooling-supplyNetworkandSubstationSimulationCalculationofLocalResistanceCoefficientofConfluenceTeewithLargerPipeDiameterCHEN Youqian,CUI Xuyang,YANG Di, LEI Wanning,HUANG Tao,BAI Chao, GAO Lin,YANG Junhong

    Abstract: The Fluent software is used to analyze the effects of Reynolds number of main pipe,split ratio (mass flow ratio of side branch pipe to main pipe),pipe diameter ratio (internal diameter ratio of side branch pipe to main pipe),intersection angle (angle between side branch pipe and straight branch pipe) on local resistance coefficient of confluence tee and fluid velocity field in the tee. The research objects are the local resistance coefficient (called resistance coefficient 1) between the side branch pipe and the main pipe of DN 400 mm and above equal diameter and reducing tee,and the local resistance coefficient (called resistance coefficient 2) between the straight branch pipe and the main pipe. The variation range of Reynolds number of main pipe is 2×105to 106(the water velocity range of corresponding main pipe is 0.5 to 2.5 m/s),the variation range of split ratio is 0.2 to 1.0,the variation range of pipe diameter ratio is 0.38 to 1.00,and the variation range of intersection angle is 30° to 90°. The influence of Reynolds number of main pipe: when the split ratio is constant,and the Reynolds number of main pipe is greater than 4×105,the resistance coefficients 1 and 2 basically do not change with the increase of Reynolds number of main pipe,that is,the local resistance coefficient enters the resistance square area. When the Reynolds number of main pipe is constant,the larger the split ratio is,the larger the resistance coefficients 1 and 2 are. When the split ratio is relatively large,especially when the split ratio is 1.0,a low-speed reflux area of large range appears in the upper part of the main pipe,and an obvious velocity gradient appears in the main pipe. The influence of pipe diameter ratio: when the split ratio is constant,the resistance coefficients 1 and 2 decrease with the increase of pipe diameter ratio. The larger the pipe diameter ratio is,the smaller the decrease in the resistance coefficients 1 and 2 is. When the pipe diameter ratio is greater than 0.8,the influence on the two is no longer significant. The smaller the split ratio is,the smaller the influence of the pipe diameter ratio is. When the pipe diameter ratio is 0.38,the water velocity in the oblique branch pipe is relatively high,and the water velocity distribution in the tee is very uneven. The larger the diameter ratio,the more uniform the pipe diameters of the straight branch,the oblique branch,and the main pipe,and the more uniform the velocity distribution,and the low-speed return area at the upper part of main pipe has also been reduced.. The influence of intersection angle: when the split ratio is constant,the resistance coefficients 1 and 2 increase with the increase of intersection angle. With the increase of the intersection angle,the low-speed reflux area in the upper part of the main pipe increases,and a significant speed gradient appears.

    Keywords: confluence tee; local resistance coefficient; velocity field; numerical simulation

    BuildingHeating,AirConditioning,VentilationandThermalEnvironmentEffectofFinArrangementonMeltingofPhaseChangeMaterialinRectangularCavityCHENG Suya,CHEN Baoming, GUO Mengxue,ZHANG Yanyong,LI Jiayang

    Abstract: The rectangular cavity filled with paraffin (divided into a rectangular cavity without fins and a rectangular cavity with fins) was used as the research object to establish a mathematical model. The finite element software COMSOL Multiphysics was used to simulate the melting behavior of paraffin in the rectangular cavity,and the influence of different fin arrangements on the melting behavior of paraffin was analyzed,so as to screen the fin arrangement that help enhance the paraffin melting. The right wall of the rectangular cavity is the heating surface,and the other three walls are adiabatic surfaces. The fins of the rectangular cavity with fins are arranged inside the heating surface. On the premise that the number of fins (3 fins) and the same interval,the total length of fins in the rectangular cavity remains unchanged,and four fin arrangement modes are set. Arrangement mode 1: The length of each fin is 32 mm. Arrangement 2 mode: The lengths of the bottom-up fins are 41,32 and 23 mm,respectively. Arrangement 3 mode: The lengths of the bottom-up fins are 23,32 and 41 mm,respectively. Arrangement 4 mode: The lengths of the bottom-up fins are 29,38 and 29 mm,respectively. For the rectangular cavity without fins,under the action of natural convection heat transfer,the paraffin in the upper right corner melts first,then the melted part diffuses to the center of the rectangular cavity until the paraffin in the lower left corner of the rectangular cavity completely melts. Adding fins in rectangular cavity can improve the melting uniformity of paraffin and shorten the melting time of paraffin in rectangular cavity. The arrangement mode 2 has the best effect on improving the melting uniformity of paraffin in the rectangular cavity,and the time of complete melting of paraffin is the shortest. Under the same heating time,the liquid phase area ratio (ratio of liquid phase paraffin area to rectangle area) of paraffin in the rectangular cavity with fins is significantly higher than that in the rectangular cavity without fins. The heating time of paraffin in the rectangular cavity without fins is 3 522 s,and the heating times of paraffin in rectangular cavity with fins arranged in 1 to 4 are 1 874,1 674,2 082 and 1 910 s,respectively. The effect of the other three fin arrangement modes on the enhancement of paraffin melting in the rectangular cavity is evaluated with the equal-length fin arrangement mode 1 as the reference. Fin arrangement 2 has obvious enhancement effect on paraffin melting in rectangular cavity,and the enhancement effect is concentrated in the middle and later stage of melting process. Arrangement modes 3 and 4 play the opposite role.

    Keywords: rectangular cavity; paraffin phase change heat storage; equal-length fin; non-equal fin; melting

    InvestigationonRuralAir-sourceHeatPumpUsersinHebeiProvinceMA Kunru,LI Xuefeng,LI Siqi

    Abstract: For the pilot users (total of 412 households) of coal-to-electricity conversion in Shijiazhuang and Baoding rural areas (newly added air-source heat pump hot water units to prepare hot water,using original indoor radiators and pipes of rural users to realize heating),the thermal habits,modification effects,and user satisfaction of rural users after the coal-to-electricity conversion were investigated,and the economic and environmental protection analysis of coal-to-electricity conversion was carried out. For the thermal habits: because the air source heat pump can be started and stopped flexibly by the user according to the comfort requirements,whether there is anyone in the home,the number of users using 24 h a day heating is declined. Most of the users who do not use auxiliary heating methods are relatively rich in economic conditions. When configuring air-source heat pumps,they have the economic ability to choose units with relatively high heating power,and their ability to cope with severe cold periods is relatively strong. Among the users who use auxiliary heating,the household conditions of users who use bulk coal and fuel wood are the least desirable. For the modification effect and satisfaction degree: the indoor temperature is 13 to 16 ℃ before the coal-to-electricity conversion,and the indoor temperature reaches 17 to 20 ℃ after the coal-to-electricity conversion,the indoor comfort is significantly improved. During the heating period,11 households reported air source heat pumps for repair,accounting for only 2.67% of the total users. 71.1% of users are very satisfied with the heating effect,and 22.1% are satisfied with it. The main reason for unsatisfactory heating effect is that it is difficult to achieve balance between heating effect and heating electricity bill. For economy and environmental protection: not only the purchase cost of air-source heat pump is favorable to rural users,but also the heating cost is greatly reduced on the basis of effectively improving the heating effect. The emission reduction effect of coal-to-electricity conversion is very obvious,if considering the centralized and efficient flue gas treatment in power plant,the emission reduction effect is more remarkable.

    Keywords: rural clean heating; air-source heat pump; coal-to-electricity conversion

    RenewableEnergyDistributedEnergySourceandCombinedCooling,HeatingandPowerPerformanceComparisonofMCCHPSystemandInfluenceofLoadVariationunderWinterandSummerConditionsQU Ying,WEI Fan,WANG Xiaoming

    Abstract: Aiming at the performance characteristics of the MCCHP system,a system based on gas combustion engine and a dual-effect lithium bromide absorption heat pump was built,and the system model was established. Through mathematical simulation,the system performance of cold water backwater temperature in summer working condition,hot water backwater temperature in winter working condition,internal combustion engine speed and internal combustion engine load rate change is analyzed. The results show that the performance of the MCCHP system under the summer condition is higher than that under the winter condition,and the COP of the system under the summer condition is 2.2 times that under the winter condition. The reduction of the user hot and cold load and the reduction of the gas engine speed will cause the COP of the system to decrease,and the reduction range of the COP of the system is greater than the primary energy utilization rate. The low load rate operation of the gas combustion engine will cause the COP of the system to decrease,and the primary energy utilization rate is also slightly decreased.

    Keywords: micro distributed system; MCCHP system; primary energy utilization rate; COP; variable condition

    ComparisonofOrganicRankineCycleWorkingFluidsofMediumTemperatureWasteHeatSourceZHANG Jianliang

    Abstract: Based on the calculation model of Levelized Electricity Costs (LEC),the subcritical cycle,supercritical cycle thermal efficiency and LEC of 7 working fluids (2-methylbutane,dichlorofluoroethane,acetone,n-heptane,benzene,octane and toluene) were investigated by the example,and the applicability of working fluids to organic Rankine cycle of medium temperature waste heat source was evaluated considering the environmental protection and safety of working fluids. The thermal efficiency of the subcritical cycle of the 7 working fluids increases with the increase of evaporation temperature,while the LEC decreases with the increase of evaporation temperature. The maximum thermal efficiency of supercritical cycle of 7 working fluids is higher than that of subcritical cycle,and the LEC is lower than that of subcritical cycle. The comprehensive performance of supercritical cycle is better than that of inlet pressure of 6.0 MPa under the condition that the inlet pressure of the expander is 5.5 MPa. Regardless of subcritical cycle or supercritical cycle,benzene and toluene show the best comprehensive performance in terms of thermal efficiency and LEC,and the comprehensive performance of dichlorofluoroethane is in the middle. Although the toxicity of benzene and toluene is low,but the flammability is high,there is a greater risk in the engineering application,which puts forward higher requirements for the sealing of pipes and equipment. Dichlorofluoroethane is not only environmentally friendly,but also has low toxicity and does not spread flame. At this stage,it is suitable as an organic Rankine cycle working fluid of medium temperature waste heat source.

    Keywords: medium temperature waste heat source; organic Rankine cycle; subcritical cycle; supercritical cycle; working fluid

    ReviewandProspectofNaturalGasDistributedEnergyDevelopmentinShanghaiGUO Jiasheng

    Abstract: The development of natural gas distributed energy started earlier in Shanghai,and is at the leading level in China. The natural gas distributed energy projects that have been completed and under construction in Shanghai from 1999 to 2019 are sorted out,and analyzed from the perspectives of operation time,operation status,prime mover types,application scenarios and geographical distribution. The policy path of distributed energy development is summarized,and the natural gas utilization history of Shanghai is introduced. Suggestions for the follow-up projects are made from the aspects of energy price impact,technical equipment upgrading,productization of engineering projects,operation management specialization and continuous optimization of business environment. The development trend of natural gas distributed energy is prospected.

    Keywords: Shanghai; natural gas distributed energy; policy pathway

    GasCombustion,GasAppliancesandGasConsumptionEquipmentEffectofExcessAirCoefficientandArrangementsofNozzlesonNOGenerationPathWANG Ge,CAO Yanguang, HE Tianzhi,CAI Lei

    Abstract: Numerical simulation is employed to study the NO generation path and key elementary reaction rates in a natural gas tunnel kiln. The influences of excess air coefficient and arrangements of nozzles (staggered arrangement of nozzles and relative arrangement of nozzles) on the NO generation path are analyzed. The results show that the main elementary reaction rates at excess air coefficient of 1.1 are lower than that of excess air coefficient of 6.0,resulting in less generation of NO. When excess air coefficient increases from 6.0 to 9.0,the reaction rate of the main elements for NO generation R251,R236,and R235 decreases and the NO generation decreases. When the nozzles are arranged in a staggered way,although the reaction direction of the R216 generating NO is opposite to the relative arrangement of the nozzles,the disturbance of the airflow in the kiln is enhanced,the main elementary reaction rate for NO generation increases,and the NO generation increases.

    Keywords: tunnel kiln; numerical simulation; NO generation path; excess air coefficient; arrangement of nozzles

    GasTransmission,Distribution,StorageandTransportationPracticeofRiskAssessmentofBuriedSteelGasPipelineZENG Rui

    Abstract: Combined with an example,the risk assessment of buried steel gas pipelines is discussed. The workflow of risk assessment of buried steel gas pipelines is introduced. The comprehensive inspection is used to collect various pipelines data required for risk pre-assessment. The risk value is calculated by scoring the probability of failure and the consequences of failure,and the risk level is determined. After the rectification of safety hidden dangers,the risk reassessment is conducted and then the risk level is re-determined. Gas enterprises use the four-color marking method to mark the gas pipeline of geographic information system and control the risk.

    孫思邈哈哈一笑:“老血不去,新血不生,沒事!這三個娃娃頭有點意思,老頭子我再領著幾位小兄小妹,陪他們玩玩,谷主你留好氣力,去對付方乾那難纏的老小子?!币贿吥ㄈプ爝叺难?,長吟道,“若夫乘天地之正,而御六氣之辯,以游無窮者,彼且惡乎待哉!變陣!”他一聲斷喝,其余六人重新步天踏斗,各歸其位,內(nèi)力一轉(zhuǎn),陣勢甫變!

    Keywords: buried steel gas pipeline; risk assessment; comprehensive inspection; risk control; four-color marking method

    ConditionsforMixingofBio-naturalGasintoUrbanGasPipelineNetworkWU Yuanyuan,ZHANG Jiawei, CHANG Xuning

    Abstract: The quality requirements and interchangeability of bio-natural gas mixed into the urban gas pipeline network are analyzed. The effects of impurities and pollutants in bio-natural gas on the use safety of gas appliances and the health of personnel are discussed. In order to comply with the quality requirements for the second class of natural gas inNaturalGas(GB 17820-2018),the bio-natural gas entering the urban gas pipeline network should meet at least the standards of the second class stipulated inStandardforQualityofBiomethane(NB/T 10136-2019). Liquid water and liquid hydrocarbons are not present in bio-natural gas under pressure and temperature conditions at the junction. Before the bio-natural gas is mixed into urban gas pipeline network,interchangeability evaluation work should be carried out to meet the requirements of the gas appliance in use. The content of impurities and pollutants in bio-natural gas should be strictly controlled,so as not to affect the use safety of gas appliances and the health of personnel.

    Keywords: bio-natural gas; urban gas pipeline network; quality; interchangeability

    GasPipelineProtectiveCulvertCrossingSubwayinImmersedAreaZHANG Yunyang

    Abstract: Combined with engineering examples,in view of city gas pipeline protective culvert crossing subway in immersed area (referring to area with higher groundwater level),the requirements of the standard for the design of protective culverts are analyzed. The key design points of semi-filled protective culvert are proposed. The cross section form of semi-filled protective culvert is given. The calculation method of anti-floating design of protective culvert in immersed area is discussed.

    Keywords: town gas pipeline crossing subway; protective culvert; semi-filled; fully immersed state; anti-floating design; immersed area

    LiquefiedNaturalGasSimulationofLow-temperatureColdStorageGroupBasedonLNGColdEnergyUtilizationHE Junyan,YU Kezhi

    Abstract: Based on the scheme of low-temperature cold storage group utilizing LNG cold energy,Aspen Hysys simulation software is used to build a complete process,compare and select 13 refrigerants,compare series and parallel connections,and analyze economic benefits. It is found that No.1 (R23),3 (R170),8 (R508A),11 (50% R170+50% R744),12 (45% R290+55% R744) and 13 (29% R290+71% R744) refrigerants are all optional. Among them,No. 11 and No. 13 refrigerants have better refrigeration effect,and No. 12 refrigerants have the best refrigeration effect. The scheme of using LNG cold energy to provide a cold source for the low-temperature cold storage group is suitable for adopting all parallel ways of different low-temperature cold storage.

    Keywords: LNG cold energy; cold storage group; Aspen Hysys software; refrigerant

    DesignandResearchonaZero-dischargeLNGTankContainerZHANG Xiaoxue,TANG Xiaowei, WANG Yang,WANG Haiwei,ZHANG Jian

    Abstract: Aiming at the problems of energy waste and environmental pollution caused by the large amount of bog produced and emptied by LNG tank container during transportation and storage,a zero-discharge LNG tank container was developed using external refrigeration equipment of high-power Stirling refrigerator as the cold source. The structure and principle of the tank container are introduced. The LNG tank container with refrigerator can effectively realize the liquefaction and recovery of BOG to avoid the release of BOG. The heat absorbed by the tank container is calculated. Pro II software is used to simulate and calculate the pressure rise of the tank container when the refrigerator is not started or started. When the refrigerator is not started,the temperature and pressure in the tank container gradually rise over time. When the refrigerator is started,the tank container pressure fluctuates periodically,first decreasing and then increasing. The influencing factors of the tank container pressurization are analyzed,and the effects of the starting and stopping pressure of the refrigerator and the initial filling rate on the pressurization rate of the tank container are discussed. When the starting pressure is the same,the tank pressure will change periodically under different starting and stopping pressures. The smaller the starting and stopping pressure difference,the shorter the change period of the tank container pressure. The operation cost is the lowest when the starting and stopping pressures of the refrigerator are 0.79 and 0.70 MPa. The larger the initial filling rate is,the slower the pressurization speed of the tank container,and the longer the starting and stopping cycle of the refrigerator. Combining with the engineering example,the economic analysis of zero-discharge LNG tank container is carried out. The static investment payback period of the zero-discharge LNG tank container renovation project is 423 days,and the annual operation net income is about 7.77× 104yuan.

    AnalysisofMainFactorsAffectingAdvancementofCoal-to-gasPointSupplyProjectGAO Limin

    Abstract: The reasons for the slow advancement of the coal-to-gas point supply project are analyzed from the aspects of standard specification,institution and supply. The specification specially adapted to the point supply project is lagging behind,the natural gas policy is incomplete,and the natural gas supply gap is large. Suggestions are made.

    Keywords: coal-to-gas; point supply; standard specification; institution; supply

    GasVehicle,ShipandGasFuelingStationCalculationofBasicStateEquationandThermalPhysicalParametersofStandardHydrogen

    LI Jianxun

    Abstract: In the field of hydrogen refueling stations,hydrogen is generally regarded as standard hydrogen. Taking standard hydrogen as the research object,the calculation of the basic state equation and thermal physical parameters (compression factor,specific enthalpy and specific entropy) of standard hydrogen are analyzed. The variation trend of thermal physical parameters with pressure at different temperatures is given.

    Keywords: standard hydrogen; basic state equation; thermal physical parameters

    EngineeringPracticeofCommercialHydrogenRefuelingStationDI Wei,LIU Wei,LIU Fei,LI Yulei

    Abstract: Based on the engineering example of Rugao hydrogen refueling station,the engineering practice experience of commercial hydrogen refueling station is summarized,involving project approval,main standards and specifications,design and construction,safety control system,commissioning and trial operation,hydrogen quality management and so on.

    Keywords: commercial hydrogen refueling station; engineering practice; hydrogen quality management

    GasSourceandProcessingUtilizationErosionSimulationandStructureImprovementofSandyNaturalGasThrottleValve

    QIAN Dongliang,TIAN Huifang

    Abstract: In the oil and gas well surface equipment,natural gas contains mud and sand,and the pipeline transport medium is gas-solid two-phase flow. Inside the throttle valve,erosion damage will occur under the continuous impact and cutting action of the gas-solid two-phase flow (especially the sand particles therein). Based on conical throttle valve and wedge throttle valve,three improved structural forms are proposed: conical throttle valve of round table valve core,wedge throttle valve of round table valve core and wedge throttle valve of three section valve core. Taking the above-mentioned five types of throttle valves with a size of DN 50 mm as examples,a geometric model was established using Pro/E 5.0 software,and modeling analysis was performed using ANSYS Fluent 14.5 software. Natural gas is used as the continuous phase,sand is used as the discrete phase,RNGk-εturbulence model is used for the continuous phase,discrete phase model is used for the discrete phase,and erosion rate formula defined in ANSYS Fluent 14.5 is used for erosion rate model. The conclusions are as follows: Under the condition of gas-solid two-phase flow,erosion damage inside throttle valve is unavoidable. The locations of erosion damage inside the throttle valve are the facing wall of the valve core,the junction of the valve core and the throttle hole,and the inner wall surface of the outlet pipe section. The software simulation results are consistent with the field erosion failure. To some extent,the three modified valve core structures have changed the movement track of sand particles,reduced the erosion of the inner wall of the outlet pipe section,and played a certain protective role in the main area of throttle valve erosion control. In addition to adopting methods to improve the structure of the valve core,the erosion damage inside the throttle can also be slowed down by adopting measures such as erosion-resistant materials,coating protection,installation of hard alloy sleeves,and installation of anti-sprint short joints.

    Keywords: oil and gas well surface equipment; throttle valve; gas-solid two-phase flow; sandy natural gas; erosion rate

    GasInformatizationComprehensiveManagementofIndoorDataforGasResidents

    SHAN Luwei

    Abstract: Aiming at the development trend of indoor information diversification of residential users,a comprehensive consideration of user needs is proposed to provide integrated technical solutions for user data collection and processing. The concentrator is responsible for the collection,storage and uploading of all indoor data,and receives instructions from the comprehensive data management platform at any time. Relying on the existing management system of settlement and service of gas company to carry out value-added business development,the gas management,flammable gas monitoring and management,fire safety,water supply management,heating management and so on are designed and integrated in the data integrated management platform.

    Keywords: indoor data; comprehensive management; Internet of things gas meter; residential user

    GasEnterpriseManagementManagementDilemmaandCountermeasureofHighConsequenceAreaofUrbanGasPipeline

    WANG Chen

    Abstract: The identification of high consequence area of urban gas pipeline is introduced,the dilemma in the management of high consequence areas is analyzed,and the concept of management unit of high consequence areas is proposed. The management and control countermeasures for pipelines in high consequence areas are analyzed from the aspects of strengthening source control,focusing on the intrinsic safety of the pipeline,improving the level of technical prevention and application,and improving emergency response capabilities.

    Keywords: urban gas pipeline; high consequence area; control; dilemma; risk; countermeasure

    OverseasGasResearchonForeignGasTheftandControl

    ZHANG Xiongjun,LIU Xingwei, ZOU Geyang

    Abstract: The per capita natural gas consumption and prices of some countries in 2018 are given. The main body of theft,common theft behavior,theft loss,control costs and control measures for foreign gas are investigated and analyzed.

    Keywords: foreign; gas theft; unaccounted-for gas; control

    猜你喜歡
    玩玩氣力孫思邈
    基于重型裝備室內(nèi)搬運及移位的組合式氣力搬運裝置設計
    中醫(yī)導引法——八段錦(六) 攢拳怒目增氣力 背后七顛百病消
    孫思邈與屠蘇酒
    玩玩學學
    做個降落傘玩玩
    游樂園
    玩玩寫寫 有趣開心
    孫思邈的長生之道——飲食之道
    中國古典舞作品《月滿春江》的氣息運用研究
    藝術評鑒(2017年16期)2017-09-20 04:56:51
    氣力式靜電感應噴霧系統(tǒng)研究
    99国产精品一区二区蜜桃av| 香蕉久久夜色| 成年版毛片免费区| 91av网一区二区| 国产一区二区在线av高清观看| 99久久无色码亚洲精品果冻| 免费看日本二区| 日日摸夜夜添夜夜添小说| 国产视频一区二区在线看| 亚洲国产精品999在线| 九色成人免费人妻av| 色精品久久人妻99蜜桃| 久久久久精品国产欧美久久久| 欧美乱色亚洲激情| 国产三级中文精品| 宅男免费午夜| 一本久久中文字幕| 日本在线视频免费播放| 欧美日韩综合久久久久久 | 国产精品av久久久久免费| 香蕉国产在线看| 国产精品永久免费网站| 国产亚洲av高清不卡| 一区福利在线观看| 嫩草影院入口| 中文字幕最新亚洲高清| 亚洲熟女毛片儿| av欧美777| 偷拍熟女少妇极品色| 国产真实乱freesex| 国产在线精品亚洲第一网站| 亚洲中文字幕一区二区三区有码在线看 | 成人特级av手机在线观看| 给我免费播放毛片高清在线观看| 蜜桃久久精品国产亚洲av| 日韩国内少妇激情av| 人人妻,人人澡人人爽秒播| 日韩三级视频一区二区三区| 无人区码免费观看不卡| 亚洲av成人一区二区三| 亚洲成人精品中文字幕电影| 91在线精品国自产拍蜜月 | 亚洲无线观看免费| 91av网一区二区| 国产伦人伦偷精品视频| 狂野欧美激情性xxxx| 亚洲一区二区三区不卡视频| 一a级毛片在线观看| 两个人视频免费观看高清| 少妇的丰满在线观看| 国产免费男女视频| 久久精品夜夜夜夜夜久久蜜豆| 91在线精品国自产拍蜜月 | 手机成人av网站| 色噜噜av男人的天堂激情| av视频在线观看入口| 成人三级做爰电影| 手机成人av网站| 亚洲一区二区三区色噜噜| 久久天堂一区二区三区四区| 久久久国产成人免费| 真实男女啪啪啪动态图| 国内少妇人妻偷人精品xxx网站 | 国产精品99久久99久久久不卡| 国产一区二区在线观看日韩 | 99久久无色码亚洲精品果冻| av黄色大香蕉| 国产午夜福利久久久久久| 99热只有精品国产| 18禁黄网站禁片午夜丰满| 色综合婷婷激情| 日韩欧美国产一区二区入口| 日本a在线网址| 国产亚洲欧美98| 亚洲av中文字字幕乱码综合| 国内少妇人妻偷人精品xxx网站 | 日本黄色视频三级网站网址| 国产精品九九99| 国产美女午夜福利| 熟妇人妻久久中文字幕3abv| 久久久久久人人人人人| 欧美av亚洲av综合av国产av| 亚洲人成伊人成综合网2020| 美女 人体艺术 gogo| 欧美国产日韩亚洲一区| 欧美日韩亚洲国产一区二区在线观看| 国内久久婷婷六月综合欲色啪| 国产高清videossex| 丁香六月欧美| 亚洲av电影不卡..在线观看| 99久久精品国产亚洲精品| 免费看十八禁软件| x7x7x7水蜜桃| 日本在线视频免费播放| 亚洲人成伊人成综合网2020| 这个男人来自地球电影免费观看| a在线观看视频网站| 免费看美女性在线毛片视频| 国产一区二区三区在线臀色熟女| 久久久久久大精品| 在线免费观看的www视频| 久久精品aⅴ一区二区三区四区| 精品人妻1区二区| 嫩草影视91久久| 免费看a级黄色片| 亚洲真实伦在线观看| 亚洲成人精品中文字幕电影| 性色av乱码一区二区三区2| 色av中文字幕| 九九在线视频观看精品| 亚洲中文av在线| aaaaa片日本免费| 国产精品亚洲美女久久久| 亚洲国产精品sss在线观看| 日本免费a在线| 欧美日韩亚洲国产一区二区在线观看| 日本黄大片高清| 久久久久久久午夜电影| 精品久久久久久成人av| 午夜福利在线观看免费完整高清在 | 日日摸夜夜添夜夜添小说| 男人舔奶头视频| 99国产综合亚洲精品| 午夜福利成人在线免费观看| 国产视频一区二区在线看| 久久精品影院6| 老司机午夜十八禁免费视频| 国语自产精品视频在线第100页| 国产精品,欧美在线| 精品欧美国产一区二区三| 美女被艹到高潮喷水动态| 波多野结衣高清无吗| 一个人免费在线观看电影 | 国产精品免费一区二区三区在线| 狂野欧美白嫩少妇大欣赏| 亚洲人成网站高清观看| 99视频精品全部免费 在线 | 一级毛片精品| 老汉色∧v一级毛片| 久久精品综合一区二区三区| 亚洲精品乱码久久久v下载方式 | 久久久精品欧美日韩精品| 久久草成人影院| 黄色日韩在线| 国产三级黄色录像| 精品久久蜜臀av无| 老汉色∧v一级毛片| or卡值多少钱| 欧美日韩亚洲国产一区二区在线观看| 国产高潮美女av| 中文字幕熟女人妻在线| 国产亚洲欧美98| 亚洲欧美精品综合一区二区三区| 久久久久久国产a免费观看| 国产69精品久久久久777片 | 久久久国产成人精品二区| 国产毛片a区久久久久| 亚洲,欧美精品.| 18禁黄网站禁片午夜丰满| 亚洲va日本ⅴa欧美va伊人久久| 日韩欧美一区二区三区在线观看| 国产精品美女特级片免费视频播放器 | 亚洲av美国av| 狂野欧美激情性xxxx| 麻豆成人av在线观看| 99在线人妻在线中文字幕| 97超级碰碰碰精品色视频在线观看| 国产精品一区二区三区四区免费观看 | a级毛片a级免费在线| 色综合欧美亚洲国产小说| 久久香蕉精品热| 亚洲无线在线观看| www.熟女人妻精品国产| 午夜影院日韩av| 嫩草影院入口| 国产午夜精品论理片| 狠狠狠狠99中文字幕| 丝袜人妻中文字幕| 高潮久久久久久久久久久不卡| 亚洲av成人不卡在线观看播放网| 日韩高清综合在线| 一本综合久久免费| 国产av不卡久久| 国产97色在线日韩免费| 色哟哟哟哟哟哟| 91av网站免费观看| 成人一区二区视频在线观看| 久久久成人免费电影| 亚洲人与动物交配视频| 婷婷精品国产亚洲av| 国产av不卡久久| 中出人妻视频一区二区| 成人特级黄色片久久久久久久| 亚洲无线在线观看| 国产在线精品亚洲第一网站| 亚洲自拍偷在线| 在线观看午夜福利视频| 亚洲最大成人中文| 亚洲中文av在线| 国产成人啪精品午夜网站| 午夜福利高清视频| 嫁个100分男人电影在线观看| 国产亚洲精品综合一区在线观看| 99久久精品热视频| 久久草成人影院| 国产一区二区三区视频了| 91av网站免费观看| 精品久久久久久久人妻蜜臀av| 97人妻精品一区二区三区麻豆| 国产精华一区二区三区| 网址你懂的国产日韩在线| 亚洲中文av在线| 国产精品久久电影中文字幕| 亚洲成人久久性| 亚洲精品中文字幕一二三四区| 亚洲国产精品久久男人天堂| 亚洲欧美日韩东京热| 午夜日韩欧美国产| 天天一区二区日本电影三级| 国产精品av视频在线免费观看| 精品熟女少妇八av免费久了| 99视频精品全部免费 在线 | 夜夜看夜夜爽夜夜摸| 俄罗斯特黄特色一大片| 亚洲在线观看片| 亚洲国产精品999在线| 真人一进一出gif抽搐免费| 天天一区二区日本电影三级| 国产一区二区三区在线臀色熟女| 国产精品一区二区免费欧美| 一区福利在线观看| 狂野欧美激情性xxxx| 1000部很黄的大片| 俺也久久电影网| 特级一级黄色大片| 88av欧美| 午夜久久久久精精品| 嫩草影视91久久| 又大又爽又粗| 手机成人av网站| 亚洲精品美女久久av网站| 校园春色视频在线观看| 12—13女人毛片做爰片一| 成人午夜高清在线视频| 香蕉久久夜色| 视频区欧美日本亚洲| 午夜成年电影在线免费观看| 日韩成人在线观看一区二区三区| 国产真实乱freesex| 国产精品98久久久久久宅男小说| or卡值多少钱| 窝窝影院91人妻| 国产精品久久久久久精品电影| 三级毛片av免费| 一级黄色大片毛片| 岛国在线免费视频观看| 亚洲av中文字字幕乱码综合| 国产欧美日韩精品亚洲av| 欧洲精品卡2卡3卡4卡5卡区| 亚洲精品一区av在线观看| 午夜免费激情av| 亚洲国产精品合色在线| 少妇裸体淫交视频免费看高清| 高潮久久久久久久久久久不卡| 国内揄拍国产精品人妻在线| 99久国产av精品| 午夜福利高清视频| 麻豆国产av国片精品| 国产精品99久久99久久久不卡| 国产精品女同一区二区软件 | 精品免费久久久久久久清纯| 亚洲无线观看免费| 一个人免费在线观看的高清视频| 午夜精品一区二区三区免费看| 在线免费观看不下载黄p国产 | 99国产精品一区二区蜜桃av| 国产成人精品久久二区二区免费| 天堂√8在线中文| 国产成人啪精品午夜网站| 久久人人精品亚洲av| 欧美成狂野欧美在线观看| 激情在线观看视频在线高清| 中文字幕熟女人妻在线| 欧美最黄视频在线播放免费| 亚洲18禁久久av| 亚洲国产中文字幕在线视频| 久久人人精品亚洲av| 熟女人妻精品中文字幕| 成人av一区二区三区在线看| 免费观看的影片在线观看| 亚洲自偷自拍图片 自拍| 国产黄a三级三级三级人| 天堂影院成人在线观看| 久久这里只有精品中国| 欧美中文综合在线视频| 美女免费视频网站| 欧美色欧美亚洲另类二区| 老熟妇仑乱视频hdxx| 久久性视频一级片| 成年女人看的毛片在线观看| 麻豆av在线久日| 岛国在线观看网站| 偷拍熟女少妇极品色| 麻豆一二三区av精品| 99热只有精品国产| 91老司机精品| 亚洲精品色激情综合| 黄色丝袜av网址大全| 五月伊人婷婷丁香| 99久久综合精品五月天人人| av天堂在线播放| 精品熟女少妇八av免费久了| 人妻夜夜爽99麻豆av| 最近最新免费中文字幕在线| 亚洲国产精品合色在线| 国产成人精品无人区| 人人妻人人看人人澡| АⅤ资源中文在线天堂| 国产在线精品亚洲第一网站| 亚洲,欧美精品.| 伦理电影免费视频| 九九久久精品国产亚洲av麻豆 | 91字幕亚洲| 欧美成狂野欧美在线观看| av天堂中文字幕网| 久久精品91无色码中文字幕| 国产精品1区2区在线观看.| 在线观看美女被高潮喷水网站 | 桃色一区二区三区在线观看| 亚洲精品一区av在线观看| 美女 人体艺术 gogo| 久久久久久九九精品二区国产| 18禁裸乳无遮挡免费网站照片| 少妇熟女aⅴ在线视频| 淫秽高清视频在线观看| 亚洲av中文字字幕乱码综合| 露出奶头的视频| 国产欧美日韩精品一区二区| 国产午夜精品久久久久久| 亚洲精品456在线播放app | 国内精品久久久久久久电影| 午夜福利高清视频| 国产精品美女特级片免费视频播放器 | 搡老妇女老女人老熟妇| 国产午夜精品论理片| 国产精品爽爽va在线观看网站| 午夜精品一区二区三区免费看| 国产91精品成人一区二区三区| 又爽又黄无遮挡网站| av天堂在线播放| 国产成人一区二区三区免费视频网站| 日韩精品青青久久久久久| 后天国语完整版免费观看| 日韩中文字幕欧美一区二区| 国产亚洲av嫩草精品影院| 亚洲精品一卡2卡三卡4卡5卡| 亚洲av熟女| 成人永久免费在线观看视频| 性色av乱码一区二区三区2| 中文资源天堂在线| 99国产综合亚洲精品| 人人妻人人看人人澡| 亚洲中文av在线| 成人一区二区视频在线观看| 女生性感内裤真人,穿戴方法视频| 精品久久久久久成人av| 夜夜看夜夜爽夜夜摸| 午夜福利18| 国产综合懂色| 亚洲色图av天堂| 久久这里只有精品中国| 亚洲人成电影免费在线| 激情在线观看视频在线高清| 男女床上黄色一级片免费看| 亚洲国产色片| 搞女人的毛片| 午夜福利18| 国产精品一区二区三区四区久久| 性色av乱码一区二区三区2| 精品久久久久久成人av| 麻豆一二三区av精品| 久久人人精品亚洲av| 久久久精品欧美日韩精品| 最近在线观看免费完整版| 人妻丰满熟妇av一区二区三区| 亚洲精品在线美女| 久久精品夜夜夜夜夜久久蜜豆| 性色avwww在线观看| 制服人妻中文乱码| 午夜福利在线在线| 精品一区二区三区四区五区乱码| 久久久久亚洲av毛片大全| 精品一区二区三区四区五区乱码| 亚洲乱码一区二区免费版| 国产97色在线日韩免费| 97人妻精品一区二区三区麻豆| 少妇的丰满在线观看| 成人三级黄色视频| 国产精品久久电影中文字幕| 欧美午夜高清在线| 久久热在线av| 免费高清视频大片| 国产伦精品一区二区三区四那| 综合色av麻豆| 欧美日韩综合久久久久久 | 久久久精品大字幕| 亚洲乱码一区二区免费版| 亚洲人成电影免费在线| 久久香蕉精品热| 国产成人精品久久二区二区91| 国产亚洲精品av在线| 在线永久观看黄色视频| xxxwww97欧美| 一个人看的www免费观看视频| 噜噜噜噜噜久久久久久91| 91麻豆av在线| 欧美中文综合在线视频| 人人妻,人人澡人人爽秒播| 久久九九热精品免费| 久久久久免费精品人妻一区二区| 99热只有精品国产| 亚洲人成电影免费在线| 女同久久另类99精品国产91| 欧美日韩中文字幕国产精品一区二区三区| 又爽又黄无遮挡网站| 国产成+人综合+亚洲专区| 欧美在线黄色| 两性夫妻黄色片| 国产精品乱码一区二三区的特点| 午夜a级毛片| 成人av在线播放网站| 啦啦啦韩国在线观看视频| 国产精品久久久久久亚洲av鲁大| 欧美激情在线99| 窝窝影院91人妻| 亚洲真实伦在线观看| 色精品久久人妻99蜜桃| 久久久久久久久免费视频了| 精华霜和精华液先用哪个| 在线观看午夜福利视频| 欧美乱色亚洲激情| 国产精品精品国产色婷婷| 99久久综合精品五月天人人| 国产野战对白在线观看| 一卡2卡三卡四卡精品乱码亚洲| 男女下面进入的视频免费午夜| 国产精品 欧美亚洲| 在线永久观看黄色视频| 一级毛片女人18水好多| 噜噜噜噜噜久久久久久91| 国产成+人综合+亚洲专区| 99国产精品一区二区蜜桃av| 全区人妻精品视频| 成年人黄色毛片网站| 免费在线观看影片大全网站| 97超级碰碰碰精品色视频在线观看| 五月伊人婷婷丁香| 日本一本二区三区精品| 久久久水蜜桃国产精品网| 在线国产一区二区在线| 99国产精品一区二区蜜桃av| 日韩中文字幕欧美一区二区| 狂野欧美白嫩少妇大欣赏| 色在线成人网| 在线播放国产精品三级| АⅤ资源中文在线天堂| 国产伦一二天堂av在线观看| 这个男人来自地球电影免费观看| 大型黄色视频在线免费观看| 午夜福利成人在线免费观看| 亚洲国产欧洲综合997久久,| 搡老熟女国产l中国老女人| 99久久无色码亚洲精品果冻| 日本黄大片高清| 精品无人区乱码1区二区| 国产不卡一卡二| 精品一区二区三区av网在线观看| 国产精品av久久久久免费| 一个人看的www免费观看视频| 久久午夜亚洲精品久久| 精品久久久久久,| 级片在线观看| 噜噜噜噜噜久久久久久91| 激情在线观看视频在线高清| 国产欧美日韩一区二区精品| 欧美av亚洲av综合av国产av| 久久热在线av| 叶爱在线成人免费视频播放| 在线观看免费视频日本深夜| x7x7x7水蜜桃| 他把我摸到了高潮在线观看| 国产成人啪精品午夜网站| 国产av不卡久久| 亚洲自偷自拍图片 自拍| 精品久久久久久久末码| 悠悠久久av| 久久草成人影院| 88av欧美| 国产免费男女视频| 国产亚洲av嫩草精品影院| 亚洲真实伦在线观看| 日本在线视频免费播放| 亚洲av日韩精品久久久久久密| 欧美激情久久久久久爽电影| 亚洲中文字幕日韩| 在线看三级毛片| 国产蜜桃级精品一区二区三区| 欧美最黄视频在线播放免费| 日日干狠狠操夜夜爽| 亚洲欧美精品综合一区二区三区| bbb黄色大片| av欧美777| 国产欧美日韩精品一区二区| 日韩av在线大香蕉| 久久久久久九九精品二区国产| 特大巨黑吊av在线直播| 国产成年人精品一区二区| 国产伦在线观看视频一区| 十八禁人妻一区二区| 神马国产精品三级电影在线观看| 午夜成年电影在线免费观看| 欧美日韩中文字幕国产精品一区二区三区| 国语自产精品视频在线第100页| 可以在线观看的亚洲视频| 最新中文字幕久久久久 | 久久久久亚洲av毛片大全| 欧美国产日韩亚洲一区| 淫秽高清视频在线观看| 搞女人的毛片| 国产欧美日韩一区二区精品| 日韩 欧美 亚洲 中文字幕| 国产探花在线观看一区二区| 欧美激情在线99| 亚洲中文字幕一区二区三区有码在线看 | 一个人看的www免费观看视频| 亚洲人成电影免费在线| 国内揄拍国产精品人妻在线| 一级毛片高清免费大全| 欧美日韩乱码在线| 亚洲色图av天堂| 久久性视频一级片| 国产精品综合久久久久久久免费| 老司机午夜十八禁免费视频| 亚洲成人中文字幕在线播放| av黄色大香蕉| АⅤ资源中文在线天堂| 91在线观看av| 欧美zozozo另类| 久久久久国产精品人妻aⅴ院| 国产成人影院久久av| 免费在线观看影片大全网站| 热99re8久久精品国产| 国产主播在线观看一区二区| 日韩欧美在线乱码| 欧美成人一区二区免费高清观看 | 欧美极品一区二区三区四区| 国产一区二区激情短视频| 国产乱人伦免费视频| 久久这里只有精品19| 国产精品久久久人人做人人爽| 欧美日本视频| 男人的好看免费观看在线视频| 欧美av亚洲av综合av国产av| 99热精品在线国产| 天天躁日日操中文字幕| 我的老师免费观看完整版| 欧美另类亚洲清纯唯美| 国产精品,欧美在线| 老司机深夜福利视频在线观看| 两性夫妻黄色片| 国产一区二区在线观看日韩 | 国产亚洲精品综合一区在线观看| 国模一区二区三区四区视频 | 国产 一区 欧美 日韩| 叶爱在线成人免费视频播放| 一区二区三区激情视频| 国产视频内射| 热99在线观看视频| 国内精品久久久久精免费| 中文字幕熟女人妻在线| 精品日产1卡2卡| 亚洲成av人片在线播放无| 91av网站免费观看| 国产精品98久久久久久宅男小说| 欧美xxxx黑人xx丫x性爽| 欧美日韩综合久久久久久 | 中国美女看黄片| 国产毛片a区久久久久| 中国美女看黄片| 1000部很黄的大片| 三级毛片av免费| 久久久久亚洲av毛片大全| 性欧美人与动物交配| 丰满的人妻完整版| 男女那种视频在线观看| 欧美黑人欧美精品刺激| 中文字幕高清在线视频| 岛国在线免费视频观看| 国产精品久久久久久久电影 | 性欧美人与动物交配| 国产伦精品一区二区三区视频9 | 久久草成人影院| 1024香蕉在线观看| 真人做人爱边吃奶动态| 亚洲精品中文字幕一二三四区| 国产视频一区二区在线看| 女警被强在线播放| 啦啦啦免费观看视频1| 99热这里只有是精品50| a级毛片a级免费在线| 国产精品一区二区三区四区免费观看 | 99久久久亚洲精品蜜臀av| 少妇的丰满在线观看| 美女黄网站色视频| 中文字幕高清在线视频|