scholarly journals Numerical Simulation on the Influence of the Longitudinal Fins on the Enhancement of a Shell-and-Tube Ice Storage Device

2020 ◽  
Vol 12 (6) ◽  
pp. 2292
Author(s):  
Pei Cai ◽  
Youxue Jiang ◽  
He Wang ◽  
Liangyu Wu ◽  
Peng Cao ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Liquid Fraction ◽  
Solidification Process ◽  
Storage Device ◽  
Ice Storage ◽  
Structure Parameters ◽  
Water Ice ◽  
Negative Effect ◽  
Higher Temperature ◽  
Shell And Tube

The theoretical model of the solidification process of a shell-and-tube ice storage (STIS) device with longitudinal fins is established. The liquid fraction, the energy-discharging rate and the ice storage ratio are investigated, with particular focus on the effects of the fin structure parameters on the solidification process. Furthermore, the temperature and the streamline distributions are discussed to reveal the mechanism of the solidification process in the STIS device and the negative effect of natural convection (NC). It is indicated that the solidification process of the STIS device is dominated by the heat transfer via the fins at the beginning, and then by the heat transfer at the water–ice interface. The ice storage is negatively affected by the NC, for the reason that the water with a higher temperature stays in the lower part of the STIS device and the temperature gradient at the water–ice interface is small. The ice storage performance can be enhanced by increasing the fin structure parameters, including height, thickness and number.

scholarly journals Numerical Study of a Horizontal and Vertical Shell and Tube Ice Storage Systems Considering Three Types of Tube

2020 ◽  
Vol 10 (3) ◽  
pp. 1059 ◽  
Author(s):  
Seyed Soheil Mousavi Ajarostaghi ◽  
Kurosh Sedighi ◽  
Mojtaba Aghajani Delavar ◽  
Sébastien Poncet
Keyword(s):  
Energy Storage ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Energy Demand ◽  
Numerical Study ◽  
Liquid Fraction ◽  
Storage System ◽  
Ice Storage ◽  
Shaped Tube ◽  
Shell And Tube

There is a growing interest in sustainable energy sources for energy demand growth of power industries. To align the demand and the consumption of electrical energy, thermal energy storage appears as an efficient method. In the summer days, by using a cold storage system like ice storage, peaks of the energy usage shift to low-load hours of midnights. Here, we investigate the charging process (namely solidification) numerically in an ice-on-coil thermal energy storage configuration, where ice is formed around the coil or tube to store the chilled energy. The considered ice storage system is a shell and tube configuration, with three kinds of tubes including a U-shaped tube, a coil tube with an inner return line, and a coil tube with an outer return line. Advanced 3D unsteady simulations are achieved to determine the effects of tube type and position of the ice storage (horizontal or vertical) on the solidification process. Results indicate that using a coil tube speeds up the ice formation, as compared with the simple U-shaped tube. The coil tube with an outer return line exhibits a better performance (more produced ice), as compared with the coil tube with an inner return line. After 16 h of solidification, the coil tube with the outer return line has about 1.057% and 1.32% lower liquid fraction in comparison with the coil tube with the inner return line and U-shaped tube, respectively, for both positions (vertical and horizontal).

Numerical Simulation of Solidification Process for a Machine Tool Bed

2011 ◽  
Vol 675-677 ◽  
pp. 987-990
Author(s):  
Ling Tang ◽  
Xu Dong Wang ◽  
Hai Jing Zhao ◽  
Man Yao
Keyword(s):  
Heat Transfer ◽  
Temperature Field ◽  
Temperature Distribution ◽  
Machine Tool ◽  
Computation Time ◽  
Solidification Process ◽  
Field Calculation ◽  
Original Design ◽  
Calculation Results ◽  
Improved Design

In this paper, the flow, heat transfer and stress during solidification process of the machine tool bed weighed about 2.5ton that has been optimized by structural topologymethod, was calculated with ProCAST software, and the causes of the crack forming in the casting of the machine tool bed was analysed. According to the calculation results, the structural design of the local part where cracks tends to form has been improved, and the heat transfer and the stress are calculated again. By comparing the temperature field with filling of molten cast iron and without filling, it has been found that there was little effect of filling on the results of temperature distribution of the cast, therefore the effect of filling can be ignored in the following temperature field calculation to save computation time. The model has been simplified in the stress field calculation with considering the complexity of the machine tool bed and the cost of computation. Then, the merits and demerits of the original design and the improved design are compared and analyzed depending on the calculated temperature and stress results. It is suggested that the improved one could get a more uniform temperature distribution and then the trend of the crack occurring can be greatly reduced. These results could provide a guide for the actual casting production, achieving the scientific control of the production of castings, ensuring the quality of the castings.

Numerical simulation of the effect of baffle cut and baffle spacing on shell side heat exchanger performance using CFD

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Swanand Gaikwad ◽  
Ashish Parmar
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Heat Exchanger ◽  
Pressure Drop ◽  
Transfer Coefficient ◽  
Numerical Results ◽  
Shell Side ◽  
Tube Heat Exchanger ◽  
Shell And Tube ◽  
Two Parameters

AbstractHeat exchangers possess a significant role in energy transmission and energy generation in most industries. In this work, a three-dimensional simulation has been carried out of a shell and tube heat exchanger (STHX) consisting of segmental baffles. The investigation involves using the commercial code of ANSYS CFX, which incorporates the modeling, meshing, and usage of the Finite Element Method to yield numerical results. Much work is available in the literature regarding the effect of baffle cut and baffle spacing as two different entities, but some uncertainty pertains when we discuss the combination of these two parameters. This study aims to find an appropriate mix of baffle cut and baffle spacing for the efficient functioning of a shell and tube heat exchanger. Two parameters are tested: the baffle cuts at 30, 35, 40% of the shell-inside diameter, and the baffle spacing’s to fit 6,8,10 baffles within the heat exchanger. The numerical results showed the role of the studied parameters on the shell side heat transfer coefficient and the pressure drop in the shell and tube heat exchanger. The investigation shows an increase in the shell side heat transfer coefficient of 13.13% when going from 6 to 8 baffle configuration and a 23.10% acclivity for the change of six baffles to 10, for a specific baffle cut. Evidence also shows a rise in the pressure drop with an increase in the baffle spacing from the ranges of 44–46.79%, which can be controlled by managing the baffle cut provided.

The Effect of Baffles in Shell and Tube Heat Exchangers

2009 ◽  
Vol 62-64 ◽  
pp. 694-699 ◽  
Author(s):  
E. Akpabio ◽  
I.O. Oboh ◽  
E.O. Aluyor
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Heat Exchangers ◽  
Proper Position ◽  
Process Industries ◽  
Overall Heat Transfer Coefficient ◽  
Shell And Tube ◽  
Optimal Values ◽  
Side Flow

Shell and tube heat exchangers in their various construction modifications are probably the most widespread and commonly used basic heat exchanger configuration in the process industries. There are many modifications of the basic configuration which can be used to solve special problems. Baffles serve two functions: Most importantly, they support the tubes in the proper position during assembly and operation and prevent vibration of the tubes caused by flow-induced eddies, and secondly, they guide the shell-side flow back and forth across the tube field, increasing the velocity and the heat transfer coefficient. The objective of this paper is to find the baffle spacing at fixed baffle cut that will give us the optimal values for the overall heat transfer coefficient. To do this Microsoft Excel 2003 package was employed. The results obtained from previous studies showed that to obtain optimal values for the overall heat transfer coefficient for the shell and tube heat exchangers a baffle cut of 20 to 25 percent of the diameter is common and the maximum spacing depends on how much support the tubes need. This was used to validate the results obtained from this study.

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