When a gas-liquid two-phase flow(GLTPF)enters a parallel separator through a T-junction,it generally splits unevenly.This phenomenon can seriously affect the operation efficiency and safety of the equipment located do...When a gas-liquid two-phase flow(GLTPF)enters a parallel separator through a T-junction,it generally splits unevenly.This phenomenon can seriously affect the operation efficiency and safety of the equipment located downstream.In order to investigate these aspects and,more specifically,the so-called bias phenomenon(all gas and liquid flowing to one pipe,while the other pipe is a liquid column that fluctuates up and down),laboratory experiments were carried out by using a T-junction connected to two parallel vertical pipes.Moreover,a GLTPF prediction model based on the principle of minimum potential energy was introduced.The research results indicate that this model can accurately predict the GLTPF state in parallel risers.The boundary of the slug flow and the churn flow in the opposite pipe can be predicted.Overall,according to the results,the pressure drop curves of the two-phase flow in the parallel risers are basically the same when there is no bias phenomenon,but the pressure drop in the parallel riser displays a large deviation when there is a slug flow-churn flow.Only when the parallel riser is in a state of asymmetric flow and one of the risers produces churn flow,the two-phase flow is prone to produce the bias phenomenon.展开更多
The single well geothermal heating(SWGH)technology has attracted extensive attention.To enhance heat extraction from SWGH,a mathematical model describing heat transfer is set up,and the key influence factor and heat t...The single well geothermal heating(SWGH)technology has attracted extensive attention.To enhance heat extraction from SWGH,a mathematical model describing heat transfer is set up,and the key influence factor and heat transfer enhancement method are discussed by thermal resistance analysis.The numerical results show that the thermal resistance of rock is far greater than that of well wall and fluid.So,reducing rock thermal resistance is the most effective method for enhancing the heat extraction power.For geothermal well planning to drill:rock thermal resistance can be reduced by increasing well diameter and rock thermal conductivity;the temperature difference between liquid and rock can be raised by increasing well depth.For already existing geothermal well:an insulator with thermal conductivity of 0.2 W/(mK)is sufficient to preserve fluid enthalpy;a decrease in injection water temperature causes the increase of heat extraction power from geothermal well and heat output from heat pump simultaneously;increasing injection velocity causes the increase of pump power consumption and heat extraction power from geothermal well as well as net heat output between them.The entrepreneurs may refer to the above data in actual project.Furthermore,filling composite materials with high thermal conductivity into leakage formation is proposed in order to reduce the thermal resistance of rocks.展开更多
基金supported by the Research Project of the Technical Inspection Center of Sinopec Shengli Oilfield Company.
文摘When a gas-liquid two-phase flow(GLTPF)enters a parallel separator through a T-junction,it generally splits unevenly.This phenomenon can seriously affect the operation efficiency and safety of the equipment located downstream.In order to investigate these aspects and,more specifically,the so-called bias phenomenon(all gas and liquid flowing to one pipe,while the other pipe is a liquid column that fluctuates up and down),laboratory experiments were carried out by using a T-junction connected to two parallel vertical pipes.Moreover,a GLTPF prediction model based on the principle of minimum potential energy was introduced.The research results indicate that this model can accurately predict the GLTPF state in parallel risers.The boundary of the slug flow and the churn flow in the opposite pipe can be predicted.Overall,according to the results,the pressure drop curves of the two-phase flow in the parallel risers are basically the same when there is no bias phenomenon,but the pressure drop in the parallel riser displays a large deviation when there is a slug flow-churn flow.Only when the parallel riser is in a state of asymmetric flow and one of the risers produces churn flow,the two-phase flow is prone to produce the bias phenomenon.
基金National Natural Science Foundation of China(No.41972314).
文摘The single well geothermal heating(SWGH)technology has attracted extensive attention.To enhance heat extraction from SWGH,a mathematical model describing heat transfer is set up,and the key influence factor and heat transfer enhancement method are discussed by thermal resistance analysis.The numerical results show that the thermal resistance of rock is far greater than that of well wall and fluid.So,reducing rock thermal resistance is the most effective method for enhancing the heat extraction power.For geothermal well planning to drill:rock thermal resistance can be reduced by increasing well diameter and rock thermal conductivity;the temperature difference between liquid and rock can be raised by increasing well depth.For already existing geothermal well:an insulator with thermal conductivity of 0.2 W/(mK)is sufficient to preserve fluid enthalpy;a decrease in injection water temperature causes the increase of heat extraction power from geothermal well and heat output from heat pump simultaneously;increasing injection velocity causes the increase of pump power consumption and heat extraction power from geothermal well as well as net heat output between them.The entrepreneurs may refer to the above data in actual project.Furthermore,filling composite materials with high thermal conductivity into leakage formation is proposed in order to reduce the thermal resistance of rocks.
