Free convection heat transfer with internal sources of heat in a liquid core of the Earth by the account of magnetic forces is considered. The core of the Earth is considered as a spherical layer. For temperature the ...Free convection heat transfer with internal sources of heat in a liquid core of the Earth by the account of magnetic forces is considered. The core of the Earth is considered as a spherical layer. For temperature the boundary conditions Ⅰ, Ⅱ, Ⅲ sorts were considered. As a result of the numerical decision of a task the fields of temperature, stream function, local and average of Nusselt number are obtained.展开更多
The safety analysis code SCTRAN for SCWR(Super Critical Water Reactor) is modified to own the capability to assess the radiation heat transfer with developing a two-dimensional heat conduction solution scheme and inco...The safety analysis code SCTRAN for SCWR(Super Critical Water Reactor) is modified to own the capability to assess the radiation heat transfer with developing a two-dimensional heat conduction solution scheme and incorporating a radiation heat transfer model. The verification of the developed radiation heat transfer model is conducted through code-to-code comparison with CATHENA. The results show that the modified SCTRAN code is successful for that the maximum absolute error and relative error of the surface temperature between results of SCTRAN and CATHENA are 6.1°C and 0.9%, which are acceptable in temperature prediction. Then,with the modified SCTRAN code, the loss of coolant accident with a total loss of emergency core cooling system(LOCA/LOECC) of Canadian-SCWR is carried out to evaluate its "no-core-melt" concept. The following conclusions are achieved: 1) in the process of LOCA, the decay heat can be totally removed by the radiation heat transfer and the natural convection of the high-temperature coolant, even without an intervention of ECCS(Emergency Core Cooling System); 2) The peak cladding temperature of the fuel pins in the inner and outer rings of the high power group are 1236°C and 1177°C respectively, which are much lower than the melting point of the fuel sheath. It indicates that the Canadian-SCWR can achieve "no-core-melt" concept under LOCA/LOECC.展开更多
The present study introduces the principles of enhanced heat transfer in the core flow to form an equivalent thermal boundary layer in the fully developed laminar tube flow, which consequently enlarges the temperature...The present study introduces the principles of enhanced heat transfer in the core flow to form an equivalent thermal boundary layer in the fully developed laminar tube flow, which consequently enlarges the temperature gradient of the fluid near the tube wall, and thereby enhances the heat transfer between the fluid and the tube wall. At the same time, the increase of flow resistance in the tube is not so obvious. Mechanism analysis and numerical calculation based on air and water have been carried out to verify the principle and method presented in this paper, which may bring positive effects to the design of heat exchanger with high heat transfer efficiency and low flow resistance.展开更多
文摘Free convection heat transfer with internal sources of heat in a liquid core of the Earth by the account of magnetic forces is considered. The core of the Earth is considered as a spherical layer. For temperature the boundary conditions Ⅰ, Ⅱ, Ⅲ sorts were considered. As a result of the numerical decision of a task the fields of temperature, stream function, local and average of Nusselt number are obtained.
基金Supported by the Doctoral Program of Higher Education of China(No.20120201110043)Atomic Energy of Canada Limited(AECL)
文摘The safety analysis code SCTRAN for SCWR(Super Critical Water Reactor) is modified to own the capability to assess the radiation heat transfer with developing a two-dimensional heat conduction solution scheme and incorporating a radiation heat transfer model. The verification of the developed radiation heat transfer model is conducted through code-to-code comparison with CATHENA. The results show that the modified SCTRAN code is successful for that the maximum absolute error and relative error of the surface temperature between results of SCTRAN and CATHENA are 6.1°C and 0.9%, which are acceptable in temperature prediction. Then,with the modified SCTRAN code, the loss of coolant accident with a total loss of emergency core cooling system(LOCA/LOECC) of Canadian-SCWR is carried out to evaluate its "no-core-melt" concept. The following conclusions are achieved: 1) in the process of LOCA, the decay heat can be totally removed by the radiation heat transfer and the natural convection of the high-temperature coolant, even without an intervention of ECCS(Emergency Core Cooling System); 2) The peak cladding temperature of the fuel pins in the inner and outer rings of the high power group are 1236°C and 1177°C respectively, which are much lower than the melting point of the fuel sheath. It indicates that the Canadian-SCWR can achieve "no-core-melt" concept under LOCA/LOECC.
基金Supported by the National Key Basic Research Development Program of China (Grant No. 2007CB206903)
文摘The present study introduces the principles of enhanced heat transfer in the core flow to form an equivalent thermal boundary layer in the fully developed laminar tube flow, which consequently enlarges the temperature gradient of the fluid near the tube wall, and thereby enhances the heat transfer between the fluid and the tube wall. At the same time, the increase of flow resistance in the tube is not so obvious. Mechanism analysis and numerical calculation based on air and water have been carried out to verify the principle and method presented in this paper, which may bring positive effects to the design of heat exchanger with high heat transfer efficiency and low flow resistance.
