The pressure characteristics inside single loop oscillating heat pipe （OHP） having 4.5 mm inner diameter copper tube with the loop height of 440 mm were addressed. Distilled water was used as working fluid inside th...The pressure characteristics inside single loop oscillating heat pipe （OHP） having 4.5 mm inner diameter copper tube with the loop height of 440 mm were addressed. Distilled water was used as working fluid inside the OHP with different filling ratios of 40%, 60% and 80% of total inside volume. Experimental results show that the thermal characteristics are significantly inter-related with pressure fluctuations as well as pressure frequency. And the pressure frequency also depends upon the evaporator temperature that is maintained in the range of 60-96 ℃. Piezoresistive absolute pressure sensor （Model-Kistler 4045A5） was used to take data. The investigation shows that the filling ratio of 60% gives the highest inside pressure magnitude at maximum number of pressure frequency at any of set evaporator temperature and the lowest heat flow resistance is achieved at 60% filling ratio.展开更多
Effects of the flow pattern of intertubular liquid film on mass and heat transfer synergies in a falling-film dehumidification system with horizontal pipes are studied.A flow model of the dehumidifying solution betwee...Effects of the flow pattern of intertubular liquid film on mass and heat transfer synergies in a falling-film dehumidification system with horizontal pipes are studied.A flow model of the dehumidifying solution between horizontal pipes is established using Fluent software,the rule of transitions of the flow pattern between pipes is studied,critical Reynolds numbers of flow pattern transitions are obtained,and the accuracy of the model is verified by experiments.The mass transfer synergy angle and heat transfer synergy angle are respectively used as evaluation criteria for the mass transfer synergy and heat transfer synergy,and distribution laws of the synergy angles for droplet,droplet columnar and curtain flow patterns are obtained.Simulation results show that the mass transfer synergy angles corresponding to droplet,droplet columnar and curtain flow patterns all rise to a plateau with time.The mean mass-transfer synergy angle is 98°for the droplet flow pattern,higher than 96.5°for the droplet columnar flow pattern and 95°for the curtain flow pattern.The results show that the mass transfer synergy of the droplet flow pattern is better than that of the droplet columnar flow pattern and that of the curtain flow pattern.展开更多
Quench chamber is the most important component in the coal gasifier,and is easy to break.In order to find the pattern of turbulent flow and heat transfer of synthetic gas in the Vertical downward pipe,a numerical mode...Quench chamber is the most important component in the coal gasifier,and is easy to break.In order to find the pattern of turbulent flow and heat transfer of synthetic gas in the Vertical downward pipe,a numerical model based on analyzing the flow and heat transfer features of the vertical pipe in quench chamber is first presented.The variations of temperature,velocity of synthetic gas with the change in length and radius of the vertical pipe and the velocity of the gas are obtained,and the effect of radiation is found. The pattern of turbulent flow and heat transfer of synthetic gas in the vertical pipe is further revealed.展开更多
基金Project(2011-0009022) supported by Basic Science Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education,Science and Technology of Korea
文摘The pressure characteristics inside single loop oscillating heat pipe （OHP） having 4.5 mm inner diameter copper tube with the loop height of 440 mm were addressed. Distilled water was used as working fluid inside the OHP with different filling ratios of 40%, 60% and 80% of total inside volume. Experimental results show that the thermal characteristics are significantly inter-related with pressure fluctuations as well as pressure frequency. And the pressure frequency also depends upon the evaporator temperature that is maintained in the range of 60-96 ℃. Piezoresistive absolute pressure sensor （Model-Kistler 4045A5） was used to take data. The investigation shows that the filling ratio of 60% gives the highest inside pressure magnitude at maximum number of pressure frequency at any of set evaporator temperature and the lowest heat flow resistance is achieved at 60% filling ratio.
基金Project(2016YFC0700100)supported by the National Key R&D Program of ChinaProject(JDJQ20160103)supported by the Promotion of the Connotation Development Quota Project of Colleges and Universities-Outstanding Youth of Architectural University,China。
文摘Effects of the flow pattern of intertubular liquid film on mass and heat transfer synergies in a falling-film dehumidification system with horizontal pipes are studied.A flow model of the dehumidifying solution between horizontal pipes is established using Fluent software,the rule of transitions of the flow pattern between pipes is studied,critical Reynolds numbers of flow pattern transitions are obtained,and the accuracy of the model is verified by experiments.The mass transfer synergy angle and heat transfer synergy angle are respectively used as evaluation criteria for the mass transfer synergy and heat transfer synergy,and distribution laws of the synergy angles for droplet,droplet columnar and curtain flow patterns are obtained.Simulation results show that the mass transfer synergy angles corresponding to droplet,droplet columnar and curtain flow patterns all rise to a plateau with time.The mean mass-transfer synergy angle is 98°for the droplet flow pattern,higher than 96.5°for the droplet columnar flow pattern and 95°for the curtain flow pattern.The results show that the mass transfer synergy of the droplet flow pattern is better than that of the droplet columnar flow pattern and that of the curtain flow pattern.
文摘Quench chamber is the most important component in the coal gasifier,and is easy to break.In order to find the pattern of turbulent flow and heat transfer of synthetic gas in the Vertical downward pipe,a numerical model based on analyzing the flow and heat transfer features of the vertical pipe in quench chamber is first presented.The variations of temperature,velocity of synthetic gas with the change in length and radius of the vertical pipe and the velocity of the gas are obtained,and the effect of radiation is found. The pattern of turbulent flow and heat transfer of synthetic gas in the vertical pipe is further revealed.
