The air oxidation of super-heavy oil at low temperature was studied in laboratory and its influences on oil viscosity, component and steam sweep efficiency before and after air-injection were analyzed. The feasibility...The air oxidation of super-heavy oil at low temperature was studied in laboratory and its influences on oil viscosity, component and steam sweep efficiency before and after air-injection were analyzed. The feasibility, operation mode and air flooding effect at the late stage of steam assisted gravity drainage(SAGD) were investigated by numerical simulation. The experimental results show for vertical-horizontal well pair SAGD test area of Xing VI Formation in Block Du 84 of Liaohe Oilfield, the low temperature oxidation occurred between 150-250 ?C(steam chamber temperature), the oil viscosity increased greatly after low temperature oxidation, consequently, the oil displacement efficiency dropped sharply. Three development methods in the late stage of SAGD were simulated, i.e., steam + air low temperature oxidation, only air low temperature oxidation and only air high temperature oxidation. By comparing production dynamic curves and residual oil distribution etc., high temperature oxidation reduced the heat loss in late stage of SAGD, recovered the residual oil effectively, and prolonged reservoir development time.展开更多
This study investigated the effects of gaseous emissions from crude storage tank and gas flaring on air and rainwater quality in Bonny Industrial Island. Ambient air quality parameters, rainwater and weather parameter...This study investigated the effects of gaseous emissions from crude storage tank and gas flaring on air and rainwater quality in Bonny Industrial Island. Ambient air quality parameters, rainwater and weather parameters were collected at 60 m, 80 m, 100 m, 200 m and control plot for 4 weeks at the Bonny. Rainwater parameters were investigated using standard laboratory tests. Data analyses were done using Analysis of variance, pairwise t-test and Pearson’s correlation statistical tools. Results show that emission rates, volatile organic compound (VOC) noise and flare temperature decreased with increasing distance from flare points and crude oil storage tanks. Findings further revealed the emission rates varied significantly with distance away from the gas flaring point (F = 6.196;p = 0.004). The mean concentration of pollutants between gas flare site and crude oil storage tank showed that CO (0.02 ± 0.001 - 0.002 ±0.001), SPM (0.011 ± 0.001 - 0.01 ± 0.001), VOC (0.005 ± 0.001 - 0.01 ± 0.001) and NO<sub>2</sub> (0.04 ± 0.001 - 0.005 ± 0.000) had significant variations (p > 0.05) with CO, O<sub>3</sub> and NO<sub>2</sub> having higher concentrations at the gas flare site while SPM, and VOC were higher around the crude oil storage tank site. Wind turbulence was higher around the gas flaring point (4.93 TKE) than the crude oil storage tank (4.55 TKE). Similarly, there was significant variation in the sun radiation, precipitation, and wind speed caused by gas flaring (1582.25 w/m<sup>2</sup>, 436.25 mm, 0.53 m/s) and crude oil storage tank (1536.25 w/m<sup>2</sup>, 3.91.41 mm, 0.51 m/s). There were also significant variations in flared temperature (F = 22.144;p = 0.001);NO<sub>2</sub> (F = 8.250;p = 0.001), CO (F = 6.000;p = 0.004) and VOC (F = 5.574;p = 0.006) with distance from the gas flaring point. The variation in the rainwater parameters with distance from the gas flaring indicated significant variations in pH (F = 5.594;p = 0.006). The study showed that the concentration of VOC and particulates were high in the supposedly control area which is perceived to be safe for human habitation. Significant variations exist in emission rate (p = 0.015), flare temperature (p = 0.001), NO<sub>2</sub> (p = 0.003), VOC (p = 0.001), noise (p = 0.041), hydrogen carbonate (p = 0.037) and chromium (p = 0.032) between the gas flaring and crude oil storage tank. Regular monitoring is advocated to mitigate the harmful effects of the pollutants.展开更多
In the present work, the performance of oil-air two-phase flow under different lubricant oils was investigated. The simulation method was applied to study the influence of the oil viscosity on the flow pattern, veloci...In the present work, the performance of oil-air two-phase flow under different lubricant oils was investigated. The simulation method was applied to study the influence of the oil viscosity on the flow pattern, velocity distribution and Re number in oil-air lubrication by FLUENT software with VOF model to acquire the working performance of oil-air lubrication for high-speed ball bearing. This method was used to obtain the optimum lubrication conditions of high-speed ball bearing. The optimum operating conditions that produce the optimum flow pattern were provided. The optimum annular flow was obtained by PAO6 oil with the low viscosity. Reynolds number influences the fluid shape and distribution of oil and air in pipe. The annular flow can be formed when Reynolds number is an appropriate value. The velocity distribution of oil-air two-phase flow at outlet was also discussed by different oil viscosities. The simulating results show that due to the effect of the oil viscosity and flow pattern the velocity decreased and expanded gradually close to the pipe wall, and the velocity increased close to the central pipe. The simulation results provide the proposal for the design and operation of oil-air two-phase flow lubrication experiments in the present work. This work provides a useful method in designing oil-air lubrication with the optimum flow pattern and the optimum operating conditions.展开更多
Air emissions during palm oil processing by smallholders are issues of public health concern demanding urgent intervention by environmentalist. In this study, six smallholder oil palm processing mills were studied inE...Air emissions during palm oil processing by smallholders are issues of public health concern demanding urgent intervention by environmentalist. In this study, six smallholder oil palm processing mills were studied inElele,Nigeria. Air emission parameters (NO2, NH3, CO, H2S, SO2, VOC), noise and meteorology (wind speed, temperature, relative humidity and pressure) were determined at three distances (10 ft,25 ftand50 ft) in both wind ward and lee ward directions from the mills covering boiling and digestion activities. The emissions from biomass were found to be significantly higher than that from fossil diesel, while noise was higher during digestion. The health implications of air emissions were discussed. The study concluded by directing attentions of regulatory agencies to monitor the activities of smallholder oil palm processing to ensure the environmental sustainability of their operations. In summary, evidence during boiling activity revealed that: · H2S ranged from - 2.400 ppm at10 ft, - 2.067 ppm at25 ftand - 0.833 ppm at50 ftfrom the mills in the wind ward direction, and - 1.167 ppm at10 ft, - 0.567 ppm at25 ftand - 0.367 ppm at50ftdistance from the mills in lee ward direction and was significantly lower during digestion. · SPM ranged from 1634 - 7853 μg/m3 at10 ft, 657 - 1110 μg/m3 at25 ftand 81 - 854 μg/m3 at50 ftfrom the mills in the wind ward direction, and 46 - 236 μg/m3 at10 ft, 44 - 120 μg/m3 at25 ftand 30 - 58 μg/m3 at50 ftfrom the mills in lee ward direction. SPM was significantly lower during digestion. · VOC ranged from 67 - 13.933 ppm at10 ft, 1.033 - 13.133 ppm at25ftand 0.500 -展开更多
The lubrication design and heat transfer determination of bearing chambers in aeroengine require a sufficient understanding of the oil droplet-film interaction and physical characteristic in an oil/air two-phase flow ...The lubrication design and heat transfer determination of bearing chambers in aeroengine require a sufficient understanding of the oil droplet-film interaction and physical characteristic in an oil/air two-phase flow state. The analyses of oil droplet movement, mass and momentum transfer during the impingement of droplet/wall, as well as wall oil film thickness and flow velocity are very important for the bearing chamber lubrication and heat transfer calculation. An integrated model in combination with droplet movement, droplet/wall impact and film flow analysis is put forward initially based on the consideration of droplet size distribution. The model makes a contribution to provide more practical and feasible technical approach, which is not only for the study of droplet-film interaction and physical behavior in bearing chambers with oil/air two-phase flow phenomena, but also useful for an insight into the essence of physical course through droplet movement and deposition, film formation and flow. The influences of chamber geometries and operating conditions on droplet deposition mass and momentum transfer, and wall film thickness and velocity distribution are discussed. The feasibility of the method by theoretical analysis is also verified by the ex- isting experimental data. The current work is conducive to expose the physical behavior of wall oil film configuration and flow in bearing chamber, and also significant for bearing chamber lubrication and heat transfer study under oil/air two-phase flow conditions.展开更多
Beating chamber is one of important components that support aero-engine rotors and research on oil droplet and oil film motions is an important part of bearing chamber lubrication and heat transfer design. Consid- eri...Beating chamber is one of important components that support aero-engine rotors and research on oil droplet and oil film motions is an important part of bearing chamber lubrication and heat transfer design. Consid- ering the pressure of sealing air is an important operating condition that affects the oil droplet and oil film mo- tions, the effect of sealing air pressure on airflow in bearing chamber is investigated in this paper firstly ; and then based on the air velocity and air/wall shear force, the oil droplet moving in core air, deposition of oil droplet im- pact on wall as well as velocity and thickness of oil film are analyzed secondly; the effect of sealing air pressure on oil droplet velocity and trajectory, deposition mass and momentum, as well as oil film velocity and thickness is discussed. The work presented in this paper is conducive to expose the oil/air two phase lubrication mechanism and has certain reference value to guide design of secondary air/oil system.展开更多
分析磁悬浮无油空压机关键技术,包括磁悬浮轴承技术、高速永磁电机技术、气动优化技术,提出矿用无油超高速磁悬浮空压机系统设计方案。采用理论分析、数值仿真与实验验证相结合的方法,开展一体式多支撑磁悬浮轴承结构创新、离心三元流...分析磁悬浮无油空压机关键技术,包括磁悬浮轴承技术、高速永磁电机技术、气动优化技术,提出矿用无油超高速磁悬浮空压机系统设计方案。采用理论分析、数值仿真与实验验证相结合的方法,开展一体式多支撑磁悬浮轴承结构创新、离心三元流叶轮气动优化及三相高速永磁同步电机适配设计,构建“主动隔振+不间断电源(uninterruptible power supply, UPS)+机械保护轴承+自发电保护”四重安全防护机制。应用结果表明,设计的矿用无油超高速磁悬浮空压机系统能效较传统设备提升了20%,转子在超高速运行时的稳定性显著增强,噪声大幅降低,同时具备智能监控、远程运维及多层安全防护功能,解决了传统设备难以适配超高速柔性转子的技术难题。展开更多
基金Supported by the China National Oil and Gas Major Project(2016ZX05012-002)
文摘The air oxidation of super-heavy oil at low temperature was studied in laboratory and its influences on oil viscosity, component and steam sweep efficiency before and after air-injection were analyzed. The feasibility, operation mode and air flooding effect at the late stage of steam assisted gravity drainage(SAGD) were investigated by numerical simulation. The experimental results show for vertical-horizontal well pair SAGD test area of Xing VI Formation in Block Du 84 of Liaohe Oilfield, the low temperature oxidation occurred between 150-250 ?C(steam chamber temperature), the oil viscosity increased greatly after low temperature oxidation, consequently, the oil displacement efficiency dropped sharply. Three development methods in the late stage of SAGD were simulated, i.e., steam + air low temperature oxidation, only air low temperature oxidation and only air high temperature oxidation. By comparing production dynamic curves and residual oil distribution etc., high temperature oxidation reduced the heat loss in late stage of SAGD, recovered the residual oil effectively, and prolonged reservoir development time.
文摘This study investigated the effects of gaseous emissions from crude storage tank and gas flaring on air and rainwater quality in Bonny Industrial Island. Ambient air quality parameters, rainwater and weather parameters were collected at 60 m, 80 m, 100 m, 200 m and control plot for 4 weeks at the Bonny. Rainwater parameters were investigated using standard laboratory tests. Data analyses were done using Analysis of variance, pairwise t-test and Pearson’s correlation statistical tools. Results show that emission rates, volatile organic compound (VOC) noise and flare temperature decreased with increasing distance from flare points and crude oil storage tanks. Findings further revealed the emission rates varied significantly with distance away from the gas flaring point (F = 6.196;p = 0.004). The mean concentration of pollutants between gas flare site and crude oil storage tank showed that CO (0.02 ± 0.001 - 0.002 ±0.001), SPM (0.011 ± 0.001 - 0.01 ± 0.001), VOC (0.005 ± 0.001 - 0.01 ± 0.001) and NO<sub>2</sub> (0.04 ± 0.001 - 0.005 ± 0.000) had significant variations (p > 0.05) with CO, O<sub>3</sub> and NO<sub>2</sub> having higher concentrations at the gas flare site while SPM, and VOC were higher around the crude oil storage tank site. Wind turbulence was higher around the gas flaring point (4.93 TKE) than the crude oil storage tank (4.55 TKE). Similarly, there was significant variation in the sun radiation, precipitation, and wind speed caused by gas flaring (1582.25 w/m<sup>2</sup>, 436.25 mm, 0.53 m/s) and crude oil storage tank (1536.25 w/m<sup>2</sup>, 3.91.41 mm, 0.51 m/s). There were also significant variations in flared temperature (F = 22.144;p = 0.001);NO<sub>2</sub> (F = 8.250;p = 0.001), CO (F = 6.000;p = 0.004) and VOC (F = 5.574;p = 0.006) with distance from the gas flaring point. The variation in the rainwater parameters with distance from the gas flaring indicated significant variations in pH (F = 5.594;p = 0.006). The study showed that the concentration of VOC and particulates were high in the supposedly control area which is perceived to be safe for human habitation. Significant variations exist in emission rate (p = 0.015), flare temperature (p = 0.001), NO<sub>2</sub> (p = 0.003), VOC (p = 0.001), noise (p = 0.041), hydrogen carbonate (p = 0.037) and chromium (p = 0.032) between the gas flaring and crude oil storage tank. Regular monitoring is advocated to mitigate the harmful effects of the pollutants.
文摘In the present work, the performance of oil-air two-phase flow under different lubricant oils was investigated. The simulation method was applied to study the influence of the oil viscosity on the flow pattern, velocity distribution and Re number in oil-air lubrication by FLUENT software with VOF model to acquire the working performance of oil-air lubrication for high-speed ball bearing. This method was used to obtain the optimum lubrication conditions of high-speed ball bearing. The optimum operating conditions that produce the optimum flow pattern were provided. The optimum annular flow was obtained by PAO6 oil with the low viscosity. Reynolds number influences the fluid shape and distribution of oil and air in pipe. The annular flow can be formed when Reynolds number is an appropriate value. The velocity distribution of oil-air two-phase flow at outlet was also discussed by different oil viscosities. The simulating results show that due to the effect of the oil viscosity and flow pattern the velocity decreased and expanded gradually close to the pipe wall, and the velocity increased close to the central pipe. The simulation results provide the proposal for the design and operation of oil-air two-phase flow lubrication experiments in the present work. This work provides a useful method in designing oil-air lubrication with the optimum flow pattern and the optimum operating conditions.
文摘Air emissions during palm oil processing by smallholders are issues of public health concern demanding urgent intervention by environmentalist. In this study, six smallholder oil palm processing mills were studied inElele,Nigeria. Air emission parameters (NO2, NH3, CO, H2S, SO2, VOC), noise and meteorology (wind speed, temperature, relative humidity and pressure) were determined at three distances (10 ft,25 ftand50 ft) in both wind ward and lee ward directions from the mills covering boiling and digestion activities. The emissions from biomass were found to be significantly higher than that from fossil diesel, while noise was higher during digestion. The health implications of air emissions were discussed. The study concluded by directing attentions of regulatory agencies to monitor the activities of smallholder oil palm processing to ensure the environmental sustainability of their operations. In summary, evidence during boiling activity revealed that: · H2S ranged from - 2.400 ppm at10 ft, - 2.067 ppm at25 ftand - 0.833 ppm at50 ftfrom the mills in the wind ward direction, and - 1.167 ppm at10 ft, - 0.567 ppm at25 ftand - 0.367 ppm at50ftdistance from the mills in lee ward direction and was significantly lower during digestion. · SPM ranged from 1634 - 7853 μg/m3 at10 ft, 657 - 1110 μg/m3 at25 ftand 81 - 854 μg/m3 at50 ftfrom the mills in the wind ward direction, and 46 - 236 μg/m3 at10 ft, 44 - 120 μg/m3 at25 ftand 30 - 58 μg/m3 at50 ftfrom the mills in lee ward direction. SPM was significantly lower during digestion. · VOC ranged from 67 - 13.933 ppm at10 ft, 1.033 - 13.133 ppm at25ftand 0.500 -
基金National Natural Science Foundation of China (50975233)
文摘The lubrication design and heat transfer determination of bearing chambers in aeroengine require a sufficient understanding of the oil droplet-film interaction and physical characteristic in an oil/air two-phase flow state. The analyses of oil droplet movement, mass and momentum transfer during the impingement of droplet/wall, as well as wall oil film thickness and flow velocity are very important for the bearing chamber lubrication and heat transfer calculation. An integrated model in combination with droplet movement, droplet/wall impact and film flow analysis is put forward initially based on the consideration of droplet size distribution. The model makes a contribution to provide more practical and feasible technical approach, which is not only for the study of droplet-film interaction and physical behavior in bearing chambers with oil/air two-phase flow phenomena, but also useful for an insight into the essence of physical course through droplet movement and deposition, film formation and flow. The influences of chamber geometries and operating conditions on droplet deposition mass and momentum transfer, and wall film thickness and velocity distribution are discussed. The feasibility of the method by theoretical analysis is also verified by the ex- isting experimental data. The current work is conducive to expose the physical behavior of wall oil film configuration and flow in bearing chamber, and also significant for bearing chamber lubrication and heat transfer study under oil/air two-phase flow conditions.
基金supported by the Natural Science Foundation of China under Grant No.51275411
文摘Beating chamber is one of important components that support aero-engine rotors and research on oil droplet and oil film motions is an important part of bearing chamber lubrication and heat transfer design. Consid- ering the pressure of sealing air is an important operating condition that affects the oil droplet and oil film mo- tions, the effect of sealing air pressure on airflow in bearing chamber is investigated in this paper firstly ; and then based on the air velocity and air/wall shear force, the oil droplet moving in core air, deposition of oil droplet im- pact on wall as well as velocity and thickness of oil film are analyzed secondly; the effect of sealing air pressure on oil droplet velocity and trajectory, deposition mass and momentum, as well as oil film velocity and thickness is discussed. The work presented in this paper is conducive to expose the oil/air two phase lubrication mechanism and has certain reference value to guide design of secondary air/oil system.
文摘分析磁悬浮无油空压机关键技术,包括磁悬浮轴承技术、高速永磁电机技术、气动优化技术,提出矿用无油超高速磁悬浮空压机系统设计方案。采用理论分析、数值仿真与实验验证相结合的方法,开展一体式多支撑磁悬浮轴承结构创新、离心三元流叶轮气动优化及三相高速永磁同步电机适配设计,构建“主动隔振+不间断电源(uninterruptible power supply, UPS)+机械保护轴承+自发电保护”四重安全防护机制。应用结果表明,设计的矿用无油超高速磁悬浮空压机系统能效较传统设备提升了20%,转子在超高速运行时的稳定性显著增强,噪声大幅降低,同时具备智能监控、远程运维及多层安全防护功能,解决了传统设备难以适配超高速柔性转子的技术难题。
