In order to improve the performance of vehicle radiators, a two-dimensional heat transfer steady-state model of the radiator was set up. The influence of the structural parameters (axial ratio) of the heat exchange tu...In order to improve the performance of vehicle radiators, a two-dimensional heat transfer steady-state model of the radiator was set up. The influence of the structural parameters (axial ratio) of the heat exchange tube on the windward side on the heat transfer performance of the radiator was studied. With the increase of the axial ratio of the heat exchange tube on the windward side, the heat exchange capacity of the heat exchange tube surface slightly decreases. The heat exchange area increases significantly, which increases the total heat exchange of the radiator and improves the heat transfer performance of the radiator. When the axial ratio increases from 1.0 to 2.0, the average surface heat transfer capacity decreases from 5664.16</span><span style="font-family:""> </span><span style="font-family:Verdana;">W/m<sup>2</sup> to 5623.57</span><span style="font-family:""> </span><span style="font-family:Verdana;">W/m<sup>2</sup>.展开更多
A system method is proposed to analyze pinch change of heat exchange problems with uncertain stream flowrates and temperatures. By an analysis of the maximum heating point and maximum cooling point of uncertain parame...A system method is proposed to analyze pinch change of heat exchange problems with uncertain stream flowrates and temperatures. By an analysis of the maximum heating point and maximum cooling point of uncertain parameters, existence of pinch jump can be determined. Based on the principle of reduced temperature interval analysis, a sufficient and necessary condition is derived for each stream supply temperature to determine if it is possible to become pinch within the specified range of uncertain parameters, then this range may be partitioned into different pinch regions. The study is a foundation for the flexibility analysis, synthesis, and retrofit of heat exchanger networks.展开更多
In this paper a lumped parameter model of a two-pass gas-to-gas crossflow heat exchanger with high speed air flow has been presented for the investigation of its transieat behaviours. The effects of both the changes o...In this paper a lumped parameter model of a two-pass gas-to-gas crossflow heat exchanger with high speed air flow has been presented for the investigation of its transieat behaviours. The effects of both the changes of inlet temperature and flow rate on outlet temperature can be predicted with this model.The calculation results under typical conditions are compared with experimental results and good agreements are obtained.展开更多
文摘In order to improve the performance of vehicle radiators, a two-dimensional heat transfer steady-state model of the radiator was set up. The influence of the structural parameters (axial ratio) of the heat exchange tube on the windward side on the heat transfer performance of the radiator was studied. With the increase of the axial ratio of the heat exchange tube on the windward side, the heat exchange capacity of the heat exchange tube surface slightly decreases. The heat exchange area increases significantly, which increases the total heat exchange of the radiator and improves the heat transfer performance of the radiator. When the axial ratio increases from 1.0 to 2.0, the average surface heat transfer capacity decreases from 5664.16</span><span style="font-family:""> </span><span style="font-family:Verdana;">W/m<sup>2</sup> to 5623.57</span><span style="font-family:""> </span><span style="font-family:Verdana;">W/m<sup>2</sup>.
文摘A system method is proposed to analyze pinch change of heat exchange problems with uncertain stream flowrates and temperatures. By an analysis of the maximum heating point and maximum cooling point of uncertain parameters, existence of pinch jump can be determined. Based on the principle of reduced temperature interval analysis, a sufficient and necessary condition is derived for each stream supply temperature to determine if it is possible to become pinch within the specified range of uncertain parameters, then this range may be partitioned into different pinch regions. The study is a foundation for the flexibility analysis, synthesis, and retrofit of heat exchanger networks.
文摘In this paper a lumped parameter model of a two-pass gas-to-gas crossflow heat exchanger with high speed air flow has been presented for the investigation of its transieat behaviours. The effects of both the changes of inlet temperature and flow rate on outlet temperature can be predicted with this model.The calculation results under typical conditions are compared with experimental results and good agreements are obtained.
基金Project(U0834002)supported by the Joint Funds of NSFC-Guangdong of ChinaProject(2009ZM0121)supported by the Fundamental Research Funds for the Central Universities,ChinaProjects(LYM09024)supported by Training Program for Excellent Young Teachers with Innovation of Guangdong University,China