A simulation model for a certain diesel engine cooling system is set up by using GT-COOL. The backwater temperature response in different operating conditions is simulated numerically. The effects of single or multipl...A simulation model for a certain diesel engine cooling system is set up by using GT-COOL. The backwater temperature response in different operating conditions is simulated numerically. The effects of single or multiple system parameters on the water temperature are analyzed. The results show that, changing different single parameters, the time taken for the steady backwater temperature is different, but relatively short;and if multiple parameters are changed, the time will be longer. Referred to the thermal balance test, the simulation results are validated and provide a basis for the intelligent control of the cooling system.展开更多
As an important high-energy chemical power source, lithium-ion power batteries come up to application problems of thermal performance, such as extended temperature range and high power charge ＆ discharge. LiFeP04 bat...As an important high-energy chemical power source, lithium-ion power batteries come up to application problems of thermal performance, such as extended temperature range and high power charge ＆ discharge. LiFeP04 battery is applied and developed well recently, its charge and discharge experiment at different temperatures and hybrid pulse power characterization （HPPC） test are analyzed, and the optimal temperature range of LiFeP04 battery is put forward. In order to provide experimental suggestion of power battery application and its thermal management, internal resistance, influencing factor of electromotive force and entropy change state of charge （SOC）, battery thermal characteristic of different charge ＆ discharge rates are summarized.展开更多
Because of the high cost of measuring the specific heat capacity and the difficulty in measuring the thermal conductivity of prismatic lithium-ion batteries,two devices with a sandwiched core of the sample-electric he...Because of the high cost of measuring the specific heat capacity and the difficulty in measuring the thermal conductivity of prismatic lithium-ion batteries,two devices with a sandwiched core of the sample-electric heating film-sample were designed and developed to measure the thermal properties of the batteries based on Fourier's thermal equation.Similar to electrical circuit modeling,two equivalent thermal circuits were constructed to model the heat loss of the self-made devices,one thermal-resistance steady circuit for the purpose of measuring the thermal conductivity,the other thermal-resistance-capacitance dynamic circuit for the purpose of measuring the specific heat capacity.Using the analytic method and recursive least squares,the lumped model parameters of these two thermal circuits were extracted to estimate the heat loss and correct the measured values of the self-made devices.Compared to the standard values of the reference samples of the glass and steel plates,the measured values were corrected to improve the measurement accuracies beyond 95% through steady thermal-circuit modeling.Compared to the measured value of the specific heat capacity of the battery sample at 50% state of charge using the calorimeter,the measured value using the self-made device was corrected in order to elevate the measurement accuracy by about 90% through dynamic thermal-circuit modeling.As verified through the experiments,it was reliable,convenient,and low cost for the proposed methodology to measure the thermal properties of prismatic lithium-ion batteries.展开更多
文摘A simulation model for a certain diesel engine cooling system is set up by using GT-COOL. The backwater temperature response in different operating conditions is simulated numerically. The effects of single or multiple system parameters on the water temperature are analyzed. The results show that, changing different single parameters, the time taken for the steady backwater temperature is different, but relatively short;and if multiple parameters are changed, the time will be longer. Referred to the thermal balance test, the simulation results are validated and provide a basis for the intelligent control of the cooling system.
基金Supported by the National High Technology Research and Development Programme of China (No. 2006AA11A192)
文摘As an important high-energy chemical power source, lithium-ion power batteries come up to application problems of thermal performance, such as extended temperature range and high power charge ＆ discharge. LiFeP04 battery is applied and developed well recently, its charge and discharge experiment at different temperatures and hybrid pulse power characterization （HPPC） test are analyzed, and the optimal temperature range of LiFeP04 battery is put forward. In order to provide experimental suggestion of power battery application and its thermal management, internal resistance, influencing factor of electromotive force and entropy change state of charge （SOC）, battery thermal characteristic of different charge ＆ discharge rates are summarized.
基金This work was supported by the National Key R&D Program of China(No.2018YFBO106104)the National Natural Science Foundation of China(No.51677006).
文摘Because of the high cost of measuring the specific heat capacity and the difficulty in measuring the thermal conductivity of prismatic lithium-ion batteries,two devices with a sandwiched core of the sample-electric heating film-sample were designed and developed to measure the thermal properties of the batteries based on Fourier's thermal equation.Similar to electrical circuit modeling,two equivalent thermal circuits were constructed to model the heat loss of the self-made devices,one thermal-resistance steady circuit for the purpose of measuring the thermal conductivity,the other thermal-resistance-capacitance dynamic circuit for the purpose of measuring the specific heat capacity.Using the analytic method and recursive least squares,the lumped model parameters of these two thermal circuits were extracted to estimate the heat loss and correct the measured values of the self-made devices.Compared to the standard values of the reference samples of the glass and steel plates,the measured values were corrected to improve the measurement accuracies beyond 95% through steady thermal-circuit modeling.Compared to the measured value of the specific heat capacity of the battery sample at 50% state of charge using the calorimeter,the measured value using the self-made device was corrected in order to elevate the measurement accuracy by about 90% through dynamic thermal-circuit modeling.As verified through the experiments,it was reliable,convenient,and low cost for the proposed methodology to measure the thermal properties of prismatic lithium-ion batteries.
