The roof separation was investigated in a coal mine as part of the site charac- terization of roof strata deterioration in a longwall roadway. The separation of laminated, weak roof strata was initially characterized ...The roof separation was investigated in a coal mine as part of the site charac- terization of roof strata deterioration in a longwall roadway. The separation of laminated, weak roof strata was initially characterized as the maximum separation, effect of geologi- cal setting on separation and the effect of mining activities (heading development, time-dependent and longwall extraction) on separation. Then the separation process was studied, so as to answer the questions of: when the separation occurs;where the separa- tion is located and what geological setting it relates to;how large of the separation is;and how the separation propagates.展开更多
Based on the energy equation of gas-liquid flow in pipeline,the explicit temperature drop formula for gas-liquid steady state calculation was derived.This formula took into consideration the Joule-Thomson effect,impac...Based on the energy equation of gas-liquid flow in pipeline,the explicit temperature drop formula for gas-liquid steady state calculation was derived.This formula took into consideration the Joule-Thomson effect,impact of terrain undulation and heat transfer with the surroundings along the line.Elimination of temperature iteration loop and integration of the explicit temperature equation,instead of enthalpy energy equation,into the conjugated hydraulic and thermal computation have been found to improve the efficiency of algorithm.Then,the inner wall temperature of gas-liquid flow was calculated by using explicit temperature equation and inner wall convective heat transfer coefficient of mixed flow which can be obtained by liquid convective heat transfer coefficient and gas convective heat transfer coefficient on the basis of liquid holdup.The temperature results of gas-liquid flow and inner wall in the case example presented both agree well with those in professional multiphase computational software OLGA.展开更多
文摘The roof separation was investigated in a coal mine as part of the site charac- terization of roof strata deterioration in a longwall roadway. The separation of laminated, weak roof strata was initially characterized as the maximum separation, effect of geologi- cal setting on separation and the effect of mining activities (heading development, time-dependent and longwall extraction) on separation. Then the separation process was studied, so as to answer the questions of: when the separation occurs;where the separa- tion is located and what geological setting it relates to;how large of the separation is;and how the separation propagates.
基金Project(2011ZX05000-026-004) supported by the National Science & Technology Specific Program of ChinaProject(2010D-5006-0604) supported by the China National Petroleum Corporation (CNPC) Innovation FoundationProject(51004167) supported by the National Natural Science Foundation of China
文摘Based on the energy equation of gas-liquid flow in pipeline,the explicit temperature drop formula for gas-liquid steady state calculation was derived.This formula took into consideration the Joule-Thomson effect,impact of terrain undulation and heat transfer with the surroundings along the line.Elimination of temperature iteration loop and integration of the explicit temperature equation,instead of enthalpy energy equation,into the conjugated hydraulic and thermal computation have been found to improve the efficiency of algorithm.Then,the inner wall temperature of gas-liquid flow was calculated by using explicit temperature equation and inner wall convective heat transfer coefficient of mixed flow which can be obtained by liquid convective heat transfer coefficient and gas convective heat transfer coefficient on the basis of liquid holdup.The temperature results of gas-liquid flow and inner wall in the case example presented both agree well with those in professional multiphase computational software OLGA.
