The Experimental Investigation of Double Pipe Heat Exchangers Prepared from Two Techniques

9th Thai Society of Mechanical Engineers, International Conference on Mechanical Engineering, TSME-ICoME (2018: Tavorn Palm Beach Resort Phuket, Thailand)Heat exchangers are the equipment used in variety of industries at all levels related to heat and thermal systems. Using heat exchangers at maximum efficiency are to reduce the amount of energy lost that impacts on environment and manufacturing cost in the industry. This research focused on comparing performances of two heat exchangers; two double-pipe heat exchangers were fabricated domestically with two different welding techniques (flare and Argon welding techniques). Both heat exchangers were tested on the same experimental setup and investigated for their thermal efficiency. Their working fluid was water, hot water and cold water flowed inside the heat exchangers were arranged as parallel (co-current) and counter flow configurations. Thermal efficiency when hot water and cold water flow rates varied in the range from 0.5 to 2 liters per minute, were also investigated. The results showed that the second heat exchanger fabricated with the Argon-welding technique showed the better thermal performance than that of the first heat exchanger fabricated with the flare technique. The thermal performances of the second heat exchanger were varied from 92% to 99% while the performances of another heat exchanger were varied from 32% to 38%. Therefore, the heat exchanger manufacturing played an important role to the heat exchanger performance. The same heat exchanger design but different fabricating technique caused lost in heat transfer process which affected the thermal performance and operating cost of the industry. © Published under licence by IOP Publishing Ltd.We would like to thank our students; Patpong WONGTHAM, Phathai KOONCHONNABOT, Apichat KEAWHON., The research described in this paper was financially supported by Faculty of Science and Engineering and Office of Campus, Kasetsart University, Chalermphrakiat Sakon Nakhon Province Campus, and Kasetsart University Research and Development Institute, Kasetsart University

Evolution Of The Science Of Thermodynamics: The History

Until late in the 18th century, thermodynamics was seen as science of energy-Science of heat and work. During the eighteen century- or until late in the 18th century, heat was seen as a weightless fluid called "caloric". Heat will flow from high temperature to a low temperature producing useful work output conserving heat. 18th century engineers knew that machinery can be designed, and this heat flow can be used to produce useful work HEAT ENGINE. In this study, it will be shown how science of thermodynamics evolved within almost a century, as the science of energy, absolute temperature and entropy. It is also shown that how the availability (Exergy) is introduced as the second law analysis at the school of thermodynamics at MIT and now it can be used in Constructal thermodynamics as workable, efficient,solutions in analyzing energy systems and all components of all energy systems while protecting the environment

Single-phase and two-phase treatments of convective heat transfer enhancement with nanofluids - A state-of-the-art review

Nanofluids have shown their advantages and potentials in improving heat transfer rates when the nanofluids are applied as working fluids in thermal systems. Researcher groups concentrating on the nanofluids have increased continuously and focused deeply into various fields; theoretically, experimentally and numerically. This review summarized the important published works on nanofluid preparations, properties, experimental and numerical heat transfer behaviors. In the simulations, two main categories were discussed in detail as the single-phase modeling which the combination of nanoparticle and base fluid is considered as a single-phase mixture with steady properties and the two-phase modeling which the nanoparticle properties and behaviors are considered separately from the base fluid properties and behaviors. (C) 2015 Elsevier Masson SAS. All rights reserved

Numerical Study Of Turbulence Nanofluid Flow To Distinguish Multiphase Flow Models For In-House Programming

ASME International Mechanical Engineering Congress and Exposition (IMECE2016), NOV 11-17, 2016, Phoenix, AZ, Amer Soc Mech EngineersFluid flow with particles are found in many engineering applications such as flows inside lab-on-a-chips and heat exchangers. In heat exchangers, nanofluids or base fluids mixed with nanoparticles are applied to be used as the working fluid instead of the traditional base fluids which have low thermal physical properties. The nanoparticle diameters are in the range from 1 to 100 nanometers are mixed with the traditional base fluids before they are applied inside the heat exchangers and the nanofluids have been proved continually that they enhance heat transfer rates of the heat exchangers. Turbulent and laminar nanofluid flows have shown different enhancements in different conditions. This work focused on comparing different turbulent nanofluid simulations which used the computational fluid dynamics, CFD, with different multiphase models. The Realizable k-s turbulence model coupled with three multiphase models; Volume of Fluid (VOF) model, Mixture model and Eulerian model, were considered and compared. The heat exchanger geometry in the work was rectangular as in the electrical device application and the nanofluid was a mixture between A1203 and water. All simulated results, then, were compared with experimental results. The comparisons showed that numerical results did not deviate from each other but their delivered-time consumptions and complications were different. If one develops his own code, Eulerian model was the most complicated while Mixture model and Eulerian model consumed longer performing times. Although the Eulerian model delivered-time consumption was long but it provided the best results, so the Eulerian model should be chosen when time consumption and errors play important roles. From this ordinary study, the first significant step of in-house program developments has started. The time consumption still indicated that the high performance computers should be selected, and properties obtained from the experimental studies should be imported to the simulation to increase the result accuracy.The authors gratefully acknowledge supports from TOBB University of Economics and Technology, Ankara, Turkey, Department of Mechanical and Manufacturing Engineering, Faculty of Science and Engineering, and Office of Chalermphrakiat Sakon Nakhon Province Campus, Kasetsart University, Chalermphrakiat Sakon Nakhon Province Campus, Thailand

CFD Aided Design Of Heat Transfer Plates For Gasketed Plate Heat Exchangers

12th ASME Biennial Conference on Engineering Systems Design and Analysis (ESDA2014), JUN 25-27, 2014, Copenhagen, DENMARK, ASMEIn this study, three-dimensional computational fluid dynamics (CFD) analyses are performed to assess the thermal-hydraulic characteristics of a commercial Gasketed Plate Heat Exchangers (GPHEx) with 30 degrees of chevron angle (Plate 1). The results of CFD analyses are compared with a computer. program (ETU HEX) previously developed based on experimental results. Heat transfer plate is scanned using photogrammetric scan method to model GPHEx. CFD model is created as two separate flow zones, one for each of hot and cold domains with a virtual plate. Mass flow inlet and pressure outlet boundary conditions are applied. The working fluid is water. Temperature and pressure distributions are obtained for a Reynolds number range of 700-3400 and total temperature difference and pressure drop values are compared with ETU HEX. A new plate (Plate2) with corrugation pattern using smaller amplitude is designed and analyzed. The thermal properties are in good agreement with experimental data for the commercial plate. For the new plate, the decrease of the amplitude leads to a smaller enlargement factor which causes a low heat transfer rate while the pressure drop remains almost constant

Experimental analysis of a mixed-plate gasketed plate heat exchanger and artificial neural net estimations of the performance as an alternative to classical correlations

In this study, experiments are performed to test the thermal and hydraulic performance of gasketed plate heat exchangers (GPHE). A heat exchanger composed of two different plate types is used for the experiments, for a Reynolds number range of 500-5000. The results are compared to the experimental results obtained for plate heat exchangers which are composed of plates that have the same geometry instead of mixing two different plates. Two methods are used to investigate the thermal and hydraulic characteristics based on the obtained experimental data. One of them is the classical correlation development for Nusselt number and friction factors. Artificial neural networks (ANNs) are also used to estimate the performance as an alternative to correlations. Different networks with various numbers of hidden neurons and layers are used to find the best configuration for predictions. The results show that, artificial neural networks can be an alternative to experimental correlations for predicting thermal and hydraulic characteristics of plate heat exchangers. They give better performance when compared to correlations which are very common in heat transfer applications. Especially for mixed plate configurations studied in this research, where different plate types are used as a combination in the complete heat exchanger, it is difficult to obtain a single correlation that represents all the plates in the heat exchanger. However, when ANN's are used, it is easier to predict the performance of mixed plate HEX and the predictions are more reliable when compared to correlations. (C) 2016 Elsevier Masson SAS. All rights reserved.This work is supported by Turkish Academy of Sciences (TUBA-GEBIP program) and Turkish Scientific and Research Council under grant 112M173

Heat Exchangers : Selection, Rating, and Thermal Design, Fourth Edition

Heat exchangers are essential in a wide range of engineering applications, including power plants, automobiles, airplanes, process and chemical industries, and heating, air-conditioning, and refrigeration systems. Revised and fully updated with new problem sets, Heat Exchangers: Selection, Rating, and Thermal Design, Fourth Edition presents a systematic treatment of heat exchangers, focusing on selection, thermal-hydraulic design, and rating. Topics discussed include Classification of heat exchangers Basic design methods of heat exchangers for sizing and rating problems Single-phase forced convection correlations for heat exchangers Pressure drop and pumping power for heat exchangers and piping circuits Design methods of heat exchangers subject to fouling Thermal design methods and processes for double-pipe, shell-and-tube, gasketed-plate, compact, and polymer heat exchangers Two-phase convection correlations for heat exchangers Thermal design of condensers and evaporators Micro/nanoheat transfer The Fourth Edition contains updated information about microscale heat exchangers and the enhancement heat transfer for applications to heat exchanger design and experiment with nanofluids. The Fourth Edition is designed for courses/modules in process heat transfer, thermal systems design, and heat exchanger technology. This text includes full coverage of all widely used heat exchanger types. A complete solutions manual and figure slides of the text’s illustrations are available for qualified adopting instructors