Because pipeline has large pipe diameter, large throughout and high pressure, once pipeline leakage accident happens, the damage is quite serious. In addition, pipeline leakage accident caused by man-made drilling oil...Because pipeline has large pipe diameter, large throughout and high pressure, once pipeline leakage accident happens, the damage is quite serious. In addition, pipeline leakage accident caused by man-made drilling oil stolen every year results in huge economic losses on oilfield. Therefore, a real-time and accurate pipeline leak detection and location system not only can effectively decrease leakage loss and reduce the waste of manpower and material resources in patrolling work, but also is conductive to the management of oil pipeline and improvement of economic efficiency of enterprise. The paper determines leak detection and location project giving priority to negative pressure wave and supplemented by flow parameter analysis. The method not only can judge the accidence of leakage timely and accurately, but also can effectively avoid leakage false alarm caused by start or stop pumps in pipeline.展开更多
Falling film generation process in lithium bromide absorption refrigeration generation system is researched in thispaper. To describe the coupled heat and mass transfer of laminar falling film in vertical generation t...Falling film generation process in lithium bromide absorption refrigeration generation system is researched in thispaper. To describe the coupled heat and mass transfer of laminar falling film in vertical generation tube, a mathematicalmodel is developed, in which the effect of mass transfer on heat transfer is carefully evaluated. Moreover,an equation related Re number with solution volume flow was also obtained in given conditions. We carried outthe experiments with the mass fraction of the inlet solution LiBr being 49.5% and obtained an empirical correlationof heat transfer with the film Re number and heat flux in different volume flow. Specifically, when 5kW/m2<qw<25kW/m2 and Re<500 the heat transfer correlation is given as: h=14009.87qw0.0764Re-0.5391.展开更多
文摘Because pipeline has large pipe diameter, large throughout and high pressure, once pipeline leakage accident happens, the damage is quite serious. In addition, pipeline leakage accident caused by man-made drilling oil stolen every year results in huge economic losses on oilfield. Therefore, a real-time and accurate pipeline leak detection and location system not only can effectively decrease leakage loss and reduce the waste of manpower and material resources in patrolling work, but also is conductive to the management of oil pipeline and improvement of economic efficiency of enterprise. The paper determines leak detection and location project giving priority to negative pressure wave and supplemented by flow parameter analysis. The method not only can judge the accidence of leakage timely and accurately, but also can effectively avoid leakage false alarm caused by start or stop pumps in pipeline.
文摘Falling film generation process in lithium bromide absorption refrigeration generation system is researched in thispaper. To describe the coupled heat and mass transfer of laminar falling film in vertical generation tube, a mathematicalmodel is developed, in which the effect of mass transfer on heat transfer is carefully evaluated. Moreover,an equation related Re number with solution volume flow was also obtained in given conditions. We carried outthe experiments with the mass fraction of the inlet solution LiBr being 49.5% and obtained an empirical correlationof heat transfer with the film Re number and heat flux in different volume flow. Specifically, when 5kW/m2<qw<25kW/m2 and Re<500 the heat transfer correlation is given as: h=14009.87qw0.0764Re-0.5391.
