Condensation Heat Transfer in Horizontal Micro-fin Tubes

Condensation Heat Transfer in Horizontal Micro-fin Tubes

Author:

Publisher:

Published: 2002

Total Pages:

ISBN-13:

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Three existing condensation heat transfer models are validated using 544 experimental data points for pure refrigerants and refrigerant mixtures. The Cavallini et al. (1999) model predicts well with the pure-refrigerant data sets. However, the Cavallini et al. (1999) model fails to predict the refrigerant-mixture data sets. The Yu and Koyama (1998) model, which is applicable for the pure refrigerants only, fails to predict most of the R22 data sets. The Kedzierski and Goncalves (1999) model, which is applicable for both pure refrigerants and refrigerant mixtures, yields relatively high mean absolute deviations for most of the pure-refrigerant data sets. The Kedzierski and Goncalves (1999) model does not account for the mass transfer thermal resistance in refrigerant mixtures. A new pure-refrigerant model and a new refrigerant-mixture semi-empirical model have been developed. Both the new models successfully predict the experimental data for pure refrigerant and for refrigerant mixtures.


Condensation Heat Transfer in Horizontal Micro-fin Tubes

Condensation Heat Transfer in Horizontal Micro-fin Tubes

Author: Chea-Chun Kung

Publisher:

Published: 2002

Total Pages:

ISBN-13:

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Three existing condensation heat transfer models are validated using 544 experimental data points for pure refrigerants and refrigerant mixtures. The Cavallini et al. (1999) model predicts well with the pure-refrigerant data sets. However, the Cavallini et al. (1999) model fails to predict the refrigerant-mixture data sets. The Yu and Koyama (1998) model, which is applicable for the pure refrigerants only, fails to predict most of the R22 data sets. The Kedzierski and Goncalves (1999) model, which is applicable for both pure refrigerants and refrigerant mixtures, yields relatively high mean absolute deviations for most of the pure-refrigerant data sets. The Kedzierski and Goncalves (1999) model does not account for the mass transfer thermal resistance in refrigerant mixtures. A new pure-refrigerant model and a new refrigerant-mixture semi-empirical model have been developed. Both the new models successfully predict the experimental data for pure refrigerant and for refrigerant mixtures.


Heat Transfer and Fluid Flow in Minichannels and Microchannels

Heat Transfer and Fluid Flow in Minichannels and Microchannels

Author: Satish Kandlikar

Publisher: Elsevier

Published: 2006

Total Pages: 492

ISBN-13: 9780080445274

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&Quot;This book explores flow through passages with hydraulic diameters from about 1 [mu]m to 3 mm, covering the range of minichannels and microchannels. Design equations along with solved examples and practice problems are also included to serve the needs of practicing engineers and students in a graduate course."--BOOK JACKET.


Industrial Heat Pump-Assisted Wood Drying

Industrial Heat Pump-Assisted Wood Drying

Author: Vasile Minea

Publisher: CRC Press

Published: 2018-08-06

Total Pages: 705

ISBN-13: 0429874065

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This book discusses conventional as well as unconventional wood drying technologies. It covers fundamental thermophysical and energetic aspects and integrates two complex thermodynamic systems, conventional kilns and heat pumps, aimed at improving the energy performance of dryers and the final quality of dried lumber. It discusses advanced components, kiln energy requirements, modeling, and software and emphasizes dryer/heat pump optimum coupling, control, and energy efficiency. Problems are included in most chapters as practical, numerical examples for process and system/components calculation and design. The book presents promising advancements and R&D challenges and future requirements.


The Principles and Practice of Heat Transfer

The Principles and Practice of Heat Transfer

Author: Ali H. Tarrad

Publisher: Cambridge Scholars Publishing

Published: 2022-12-21

Total Pages: 531

ISBN-13: 1527591883

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The imminent need to mitigate the global warming potential (GWP) and the impact of the ozone depletion potential (ODP) demand seeking more efficient uses of energy, new energy sources, and new technologies. Heat transfer plays a vital role in efficient power production with minimum investment, installation, and maintenance costs. This book deals with issues related to efficiently utilizing available energy by integrating the technology of heat exchangers into power production units. Further, it provides detailed descriptions of heat transfer applications commonly used in modern everyday life and industrial contexts, supported by practical and worked-out examples presented to facilitate learning.


A Review on Condensation Process of Refrigerants in Horizontal Microfin Tubes

A Review on Condensation Process of Refrigerants in Horizontal Microfin Tubes

Author: Thanh Nhan Phan

Publisher:

Published: 2022

Total Pages: 0

ISBN-13:

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Heat transfer performance of refrigerant on the condensation process is very important in the designing of condensation equipment, especially in air conditioning and refrigeration systems. The outstanding advantages of microfin tubes are reducing the weight and size of condensers and also reducing the amount of refrigerant on the system. Reviewing the general concept of condensation and detailing the formation of flow pattern map that is also the procedure to determine heat transfer coefficient and pressure drop during condensation process of refrigerant inside the horizontal microfin tubes would be considered. Also, a typical example will be presented to illustrate a detailed procedure to calculate the value of heat transfer coefficient and pressure drop during the condensation process in horizontal microfin tubes. The data results show that microfin tube J60 with 60 number of fins inside 8.96 mm inner diameter, 0.2 mm height of fin, 40o of apex angle and 18o of helix angle, the condensation procedure of R1234ze at 35°C, heat flux of 8.62 kW/m2, and mass flux of 222 kg/m2s that could be estimated with heat transfer coefficient would be reduced from 8160.4 [W/m2 K] to 1413.8 [W/m2 K] follow with quality x changes from 0.99 to 0.01, and the maximum pressure drop of this process is 3173.8 [Pa/m].