The Experts below are selected from a list of 89760 Experts worldwide ranked by ideXlab platform

Mingjun Yang - One of the best experts on this subject based on the ideXlab platform.

  • Heat Transfer Analysis of methane hydrate sediment dissociation in a closed reactor by a thermal method
    Energies, 2012
    Co-Authors: Jiafei Zhao, Chuanxiao Cheng, Yongchen Song, Zhi Yang, Dayong Wang, Mingjun Yang
    Abstract:

    The Heat Transfer Analysis of hydrate-bearing sediment involved phase changes is one of the key requirements of gas hydrate exploitation techniques. In this paper, experiments were conducted to examine the Heat Transfer performance during hydrate formation and dissociation by a thermal method using a 5L volume reactor. This study simulated porous media by using glass beads of uniform size. Sixteen platinum resistance thermometers were placed in different position in the reactor to monitor the temperature differences of the hydrate in porous media. The influence of production temperature on the production time was also investigated. Experimental results show that there is a delay when hydrate decomposed in the radial direction and there are three stages in the dissociation period which is influenced by the rate of hydrate dissociation and the Heat flow of the reactor. A significant temperature difference along the radial direction of the reactor was obtained when the hydrate dissociates and this phenomenon could be enhanced by raising the production temperature. In addition, hydrate dissociates homogeneously and the temperature difference is much smaller than the other conditions when the production temperature is around the 10 °C. With the increase of the production temperature, the maximum of Δ T oi grows until the temperature reaches 40 °C. The period of Δ T oi have a close relation with the total time of hydrate dissociation. Especially, the period of Δ T oi with production temperature of 10 °C is twice as much as that at other temperatures. Under these experimental conditions, the Heat is mainly Transferred by conduction from the dissociated zone to the dissociating zone and the production temperature has little effect on the convection of the water in the porous media.

  • Heat Transfer Analysis of methane hydrate sediment dissociation in a closed reactor by a thermal method
    Energies, 2012
    Co-Authors: Jiafei Zhao, Chuanxiao Cheng, Yongchen Song, Zhi Yang, Dayong Wang, Weiguo Liu, Yu Liu, Kaihua Xue, Zihao Zhu, Mingjun Yang
    Abstract:

    The Heat Transfer Analysis of hydrate-bearing sediment involved phase changes is one of the key requirements of gas hydrate exploitation techniques. In this paper, experiments were conducted to examine the Heat Transfer performance during hydrate formation and dissociation by a thermal method using a 5L volume reactor. This study simulated porous media by using glass beads of uniform size. Sixteen platinum resistance thermometers were placed in different position in the reactor to monitor the temperature differences of the hydrate in porous media. The influence of production temperature on the production time was also investigated. Experimental results show that there is a delay when hydrate decomposed in the radial direction and there are three stages in the dissociation period which is influenced by the rate of hydrate dissociation and the Heat flow of the reactor. A significant temperature difference along the radial direction of the reactor was obtained when the hydrate dissociates and this phenomenon could be enhanced by raising the production temperature. In addition, hydrate dissociates homogeneously and the temperature difference is much smaller than the other conditions when the production temperature is around the 10 °C. With the increase of the production temperature, the maximum of Δ T oi grows until the temperature reaches 40 °C. The period of Δ T oi have a close relation with the total time of hydrate dissociation. Especially, the period of Δ T oi with production temperature of 10 °C is twice as much as that at other temperatures. Under these experimental conditions, the Heat is mainly Transferred by conduction from the dissociated zone to the dissociating zone and the production temperature has little effect on the convection of the water in the porous media.

Silvio Vaschetto - One of the best experts on this subject based on the ideXlab platform.

  • Conjugate Heat Transfer Analysis of Integrated Brushless Generators for More Electric Engines
    IEEE Transactions on Industry Applications, 2014
    Co-Authors: Marco Tosetti, Paolo Maggiore, Andrea Cavagnino, Silvio Vaschetto
    Abstract:

    In this paper, a complete conjugate Heat Transfer Analysis of a scaled-sized prototype of an integrated air-cooled surface-mounted permanent-magnet generator for the “more-electric engine” application is presented. The selected integration position inside the aircraft's main gas turbine engine imposes the use of an unconventional cooling system, where the coolant directly flows through the machine air gap. To predict and prevent the critical working conditions of the prototype, the adopted cooling system has been investigated using a complete fluid-thermal Analysis. Due to the capabilities of computational fluid dynamic software, it has been possible to analyze the temperature and flow fields inside the machine, giving an idea about the distribution of the thermal quantities both inside the solid materials and above the surfaces. The numerical model validation has been provided, comparing computed and experimental results, i.e., imposing the same working conditions, the predicted temperatures satisfactorily agree with the measured temperatures.

  • Conjugate Heat Transfer Analysis of integrated brushless generators for more electric engines
    2013 IEEE Energy Conversion Congress and Exposition, 2013
    Co-Authors: Marco Tosetti, Paolo Maggiore, Andrea Cavagnino, Silvio Vaschetto
    Abstract:

    In the paper a complete conjugate Heat Transfer Analysis of a scaled-size prototype of an integrated, air-cooled, surface mounted, PM generator for “More Electric Engine” application is presented. The selected integration position inside the aircraft main gas turbine engine imposes the use of a unconventional cooling system, where the coolant directly flows through the machine airgap. To predict and prevent critical working conditions of the prototype, the adopted cooling system has been investigated by means of a complete fluid-thermal Analysis. Thanks to the capabilities of computational fluid dynamic software, it has been possible to analyze the temperatures and flow fields inside the machine, giving an idea of the distribution of thermal quantities both inside the solid materials and above the surfaces. The numerical model validation has been provided comparing computed and experimental results: imposing the same working conditions, the predicted temperatures satisfactory agree with the measured ones.

Jiafei Zhao - One of the best experts on this subject based on the ideXlab platform.

  • Heat Transfer Analysis of methane hydrate sediment dissociation in a closed reactor by a thermal method
    Energies, 2012
    Co-Authors: Jiafei Zhao, Chuanxiao Cheng, Yongchen Song, Zhi Yang, Dayong Wang, Mingjun Yang
    Abstract:

    The Heat Transfer Analysis of hydrate-bearing sediment involved phase changes is one of the key requirements of gas hydrate exploitation techniques. In this paper, experiments were conducted to examine the Heat Transfer performance during hydrate formation and dissociation by a thermal method using a 5L volume reactor. This study simulated porous media by using glass beads of uniform size. Sixteen platinum resistance thermometers were placed in different position in the reactor to monitor the temperature differences of the hydrate in porous media. The influence of production temperature on the production time was also investigated. Experimental results show that there is a delay when hydrate decomposed in the radial direction and there are three stages in the dissociation period which is influenced by the rate of hydrate dissociation and the Heat flow of the reactor. A significant temperature difference along the radial direction of the reactor was obtained when the hydrate dissociates and this phenomenon could be enhanced by raising the production temperature. In addition, hydrate dissociates homogeneously and the temperature difference is much smaller than the other conditions when the production temperature is around the 10 °C. With the increase of the production temperature, the maximum of Δ T oi grows until the temperature reaches 40 °C. The period of Δ T oi have a close relation with the total time of hydrate dissociation. Especially, the period of Δ T oi with production temperature of 10 °C is twice as much as that at other temperatures. Under these experimental conditions, the Heat is mainly Transferred by conduction from the dissociated zone to the dissociating zone and the production temperature has little effect on the convection of the water in the porous media.

  • Heat Transfer Analysis of methane hydrate sediment dissociation in a closed reactor by a thermal method
    Energies, 2012
    Co-Authors: Jiafei Zhao, Chuanxiao Cheng, Yongchen Song, Zhi Yang, Dayong Wang, Weiguo Liu, Yu Liu, Kaihua Xue, Zihao Zhu, Mingjun Yang
    Abstract:

    The Heat Transfer Analysis of hydrate-bearing sediment involved phase changes is one of the key requirements of gas hydrate exploitation techniques. In this paper, experiments were conducted to examine the Heat Transfer performance during hydrate formation and dissociation by a thermal method using a 5L volume reactor. This study simulated porous media by using glass beads of uniform size. Sixteen platinum resistance thermometers were placed in different position in the reactor to monitor the temperature differences of the hydrate in porous media. The influence of production temperature on the production time was also investigated. Experimental results show that there is a delay when hydrate decomposed in the radial direction and there are three stages in the dissociation period which is influenced by the rate of hydrate dissociation and the Heat flow of the reactor. A significant temperature difference along the radial direction of the reactor was obtained when the hydrate dissociates and this phenomenon could be enhanced by raising the production temperature. In addition, hydrate dissociates homogeneously and the temperature difference is much smaller than the other conditions when the production temperature is around the 10 °C. With the increase of the production temperature, the maximum of Δ T oi grows until the temperature reaches 40 °C. The period of Δ T oi have a close relation with the total time of hydrate dissociation. Especially, the period of Δ T oi with production temperature of 10 °C is twice as much as that at other temperatures. Under these experimental conditions, the Heat is mainly Transferred by conduction from the dissociated zone to the dissociating zone and the production temperature has little effect on the convection of the water in the porous media.

Kemal Ermis - One of the best experts on this subject based on the ideXlab platform.

  • Heat Transfer Analysis of phase change process in a finned tube thermal energy storage system using artificial neural network
    International Journal of Heat and Mass Transfer, 2007
    Co-Authors: Aytunc Erek, Kemal Ermis, Ibrahim Dincer
    Abstract:

    In this study, a feed-forward back-propagation artificial neural network (ANN) algorithm is proposed for Heat Transfer Analysis of phase change process in a finned-tube, latent Heat thermal energy storage system. Heat storage through phase change material (PCM) around the finned tube is experimentally studied. A numerical study is performed to investigate the effect of fin and flow parameter by the solving governing equations for the Heat Transfer fluid, pipe wall and phase change material. Learning process is applied to correlate the total Heat stored in different fin types of tubes, various Reynolds numbers and different inlet temperatures. A number of hidden numbers of ANN are trained for the best output prediction of the Heat storage. The predicted total Heat storage values obtained by an ANN model with extensive sets of non-training experimental data are then compared with experimental measurements and numerical results. The trained ANN model with an absolute mean relative error of 5.58% shows good performance to predict the total amount of Heat stored. The ANN results are found to be more accurate than the numerical model results. The present study using ANN approach for Heat Transfer Analysis in phase change Heat storage process appears to be significant for practical thermal energy storage applications.

Min Zeng - One of the best experts on this subject based on the ideXlab platform.

  • Heat Transfer Analysis for shell and tube Heat exchangers with experimental data by artificial neural networks approach
    Applied Thermal Engineering, 2007
    Co-Authors: Qiuwang Wang, Min Zeng
    Abstract:

    This work applied Artificial Neural Network (ANN) for Heat Transfer Analysis of shell-and-tube Heat exchangers with segmental baffles or continuous helical baffles. Three Heat exchangers were experimentally investigated. Limited experimental data was obtained for training and testing neural network configurations. The commonly used Back Propagation (BP) algorithm was used to train and test networks. Prediction of the outlet temperature differences in each side and overall Heat Transfer rates were performed. Different network configurations were also studied by the aid of searching a relatively better network for prediction. The maximum deviation between the predicted results and experimental data was less than 2%. Comparison with correlation for prediction shows superiority of ANN. It is recommended that ANN can be used to predict the performances of thermal systems in engineering applications, such as modeling Heat exchangers for Heat Transfer Analysis.