抽油机日常维护过程中,为保证采油树井口不渗不漏,通常将盘根压得较紧,导致光杆与盘根间摩擦力增大,从而使抽油机电动机耗电量及盘根消耗量增加。为了掌握盘根在不同松紧状态下抽油机井的能耗情况,进行了盘根盒调整扭矩的多次试验,总结...抽油机日常维护过程中,为保证采油树井口不渗不漏,通常将盘根压得较紧,导致光杆与盘根间摩擦力增大,从而使抽油机电动机耗电量及盘根消耗量增加。为了掌握盘根在不同松紧状态下抽油机井的能耗情况,进行了盘根盒调整扭矩的多次试验,总结出盘根不同松紧度对能耗的影响规律。通过试验确定出光杆微带油状态为最节能状态,现场对比5644井次,共节电218.4×104k Wh,平均单井日节电1.06 k Wh,年创经济效益128.125万元;并制定了合理光杆盘根松紧度判定标准,使盘根管理进入常态化,达到在实际应用中节能降耗的目的。展开更多
Observational data of mesoscale surface weather stations and weather radars of Guangdong province are employed to analyze the asymmetric distribution of convection prior to, during and after landfall for tropical cycl...Observational data of mesoscale surface weather stations and weather radars of Guangdong province are employed to analyze the asymmetric distribution of convection prior to, during and after landfall for tropical cyclones of Chanchu and Prapiroon making landfall on the south China coast in 2006. The results showed that strong convection is located in the eastern and northern sectors of the landfalling Chanchu and Prapiroon, namely in the front and right portions of the TC tracks, for a period of time starting from 12 h prior to landfall to 6 h after it. Their convection also had distinct differences in the vertical direction. The analysis indicated that although the landfall of Chanchu and Prapiroon has the same asymmetric distribution of convection, the causes are not exactly the same. The asymmetric distribution of convection in the case of Chanchu is mainly correlated with the impacts of a strong environmental vertical wind shear, low-level horizontal wind shear, and low-level convergence and divergence. In the case of Prapiroon, however, the asymmetric distribution of convection is mainly associated with the impacts of low-level convergence and divergence.展开更多
For efficient utilization of a limited geothermal resource in practical projects,the cycle parameters were comprehensively analyzed by combining with the heat transfer performance of the plate heat exchanger,with a va...For efficient utilization of a limited geothermal resource in practical projects,the cycle parameters were comprehensively analyzed by combining with the heat transfer performance of the plate heat exchanger,with a variation of flowrate of R245 fa.The influence of working fluid flowrate on a 500 W ORC system was investigated.Adjusting the working fluid flowrate to an optimal value results in the most efficient heat transfer and hence the optimal heat transfer parameters of the plate heat exchanger can be determined.Therefore,for the ORC systems,optimal working fluid flowrate should be controlled.Using different temperature hot water as the heat source,it is found that the optimal flowrate increases by 6-10 L/h with 5 ℃ increment of hot water inlet temperature.During experiment,lower degree of superheat of the working fluid at the outlet the plate heat exchanger may lead to unstable power generation.It is considered that the plate heat exchanger has a compact construction which makes its bulk so small that liquid mixture causes the unstable power generation.To avoid this phenomenon,the flow area of plate heat exchanger should be larger than the designed one.Alternatively,installing a small shell and tube heat exchanger between the outlet of plate heat exchanger and the inlet of expander can be another solution.展开更多
As the operation time of heat exchanger is increased, the thermal performance of them is gradually degraded due to fouling generated by water-borne deposits which are known to reduce the thermal efficiencies. Currentl...As the operation time of heat exchanger is increased, the thermal performance of them is gradually degraded due to fouling generated by water-borne deposits which are known to reduce the thermal efficiencies. Currently, thermal performance management of heat exchangers is more importantly issued for long term operation. Therefore, the performance evaluation techniques are required to improve the present method for the integrity evaluation of heat exchangers because of the exclusion of fouling calculation and the uncertainty analysis. This paper describes the developed thermal performance evaluation technique applied to the safety-related heat exchangers such as component cooling heat exchangers in a nuclear power plants.展开更多
文摘抽油机日常维护过程中,为保证采油树井口不渗不漏,通常将盘根压得较紧,导致光杆与盘根间摩擦力增大,从而使抽油机电动机耗电量及盘根消耗量增加。为了掌握盘根在不同松紧状态下抽油机井的能耗情况,进行了盘根盒调整扭矩的多次试验,总结出盘根不同松紧度对能耗的影响规律。通过试验确定出光杆微带油状态为最节能状态,现场对比5644井次,共节电218.4×104k Wh,平均单井日节电1.06 k Wh,年创经济效益128.125万元;并制定了合理光杆盘根松紧度判定标准,使盘根管理进入常态化,达到在实际应用中节能降耗的目的。
基金National Basic Research Program of China (973 program) (2009CB421500)National Natural Science Foundation of China (90715031+3 种基金 40875026 and 40730948)Project of City University of Hong Kong (7001994)Natural Science Foundation of Guangdong Province of China (8351030101000002)
文摘Observational data of mesoscale surface weather stations and weather radars of Guangdong province are employed to analyze the asymmetric distribution of convection prior to, during and after landfall for tropical cyclones of Chanchu and Prapiroon making landfall on the south China coast in 2006. The results showed that strong convection is located in the eastern and northern sectors of the landfalling Chanchu and Prapiroon, namely in the front and right portions of the TC tracks, for a period of time starting from 12 h prior to landfall to 6 h after it. Their convection also had distinct differences in the vertical direction. The analysis indicated that although the landfall of Chanchu and Prapiroon has the same asymmetric distribution of convection, the causes are not exactly the same. The asymmetric distribution of convection in the case of Chanchu is mainly correlated with the impacts of a strong environmental vertical wind shear, low-level horizontal wind shear, and low-level convergence and divergence. In the case of Prapiroon, however, the asymmetric distribution of convection is mainly associated with the impacts of low-level convergence and divergence.
基金Project (2012AA053001) supported by High-tech Research and Development Program of China
文摘For efficient utilization of a limited geothermal resource in practical projects,the cycle parameters were comprehensively analyzed by combining with the heat transfer performance of the plate heat exchanger,with a variation of flowrate of R245 fa.The influence of working fluid flowrate on a 500 W ORC system was investigated.Adjusting the working fluid flowrate to an optimal value results in the most efficient heat transfer and hence the optimal heat transfer parameters of the plate heat exchanger can be determined.Therefore,for the ORC systems,optimal working fluid flowrate should be controlled.Using different temperature hot water as the heat source,it is found that the optimal flowrate increases by 6-10 L/h with 5 ℃ increment of hot water inlet temperature.During experiment,lower degree of superheat of the working fluid at the outlet the plate heat exchanger may lead to unstable power generation.It is considered that the plate heat exchanger has a compact construction which makes its bulk so small that liquid mixture causes the unstable power generation.To avoid this phenomenon,the flow area of plate heat exchanger should be larger than the designed one.Alternatively,installing a small shell and tube heat exchanger between the outlet of plate heat exchanger and the inlet of expander can be another solution.
文摘As the operation time of heat exchanger is increased, the thermal performance of them is gradually degraded due to fouling generated by water-borne deposits which are known to reduce the thermal efficiencies. Currently, thermal performance management of heat exchangers is more importantly issued for long term operation. Therefore, the performance evaluation techniques are required to improve the present method for the integrity evaluation of heat exchangers because of the exclusion of fouling calculation and the uncertainty analysis. This paper describes the developed thermal performance evaluation technique applied to the safety-related heat exchangers such as component cooling heat exchangers in a nuclear power plants.
