scholarly journals Heat Transfer Parameterization towards Enhancing Shelf Life of Vegetables in Low Cost Cold Chain with FACCC

2020 ◽  
Vol 9 (4) ◽  
pp. 822-829
Keyword(s):  
Heat Transfer ◽  
Nusselt Number ◽  
Shelf Life ◽  
Temperature Control ◽  
Low Cost ◽  
Surface Heat ◽  
Cold Chain ◽  
Air Flow Rate ◽  
Surface Heat Transfer Coefficient ◽  
And Storage

India is the second-largest vegetable producing country after China. It is observed that there is a huge loss of vegetables due to the lack of low-cost cold chain for its storage & transportation after harvesting from agriculture land to vegetable market. The shelf life of these vegetables is less due to poor temperature control during transportation and storage. If vegetables are not maintained at their prudent temperature, then they will lose their potency, which will lead to enormous economic loss. Therefore, it is observed that temperature control of vegetables and their heat transfer characteristics are a major factor to maintain potency and increase their shelf life. This paper proposed a low-cost design of FACCC for temperature control of vegetables during transportation and storage with the help of Chillers. Further, the effect of air velocity on heat transfer rate and Nusselt number of various vegetables was evaluated to predict the performance of FACCC for enhancing the shelf life of vegetables.Thermophysical characteristics of these vegetables have been calculated at different air flow rate with the help of Reynolds analogy as a function of Stanton Number, Reynold’s Number and Prandtl Number.The airflow rate was maintained between 0.2065 m/s - 0.413 m/s inside FACCC. Experimental study reveals that the average Nusselt Number of these vegetables lies in the range of 57.9 - 115.74 and the range of Surface heat transfer coefficient is 54.48-108.96 W/m2K. Validation of FACCC performance has been done by comparing the heat transfer rate and Nusselt number from published literature. These results are obtained by temperature control of vegetables by varying air flow rate through four fans fitted inside FACCC. It results in higher shelf life due to favourable maintenance of thermodynamic parameters such as surface heat transfer coefficient, Nusselt number, Reynold number and preferable temperature for specific commodities.Thus, the proposed FACCC model can be an effective tool for enhancement of low-cost cold chain for vegetables in future.

The Research on the Key Factor Affect the Precision in Stress Analysis for the Rotor of Steam Turbine

2013 ◽  
Vol 275-277 ◽  
pp. 83-86
Author(s):  
Chun Lin Zhang ◽  
Nian Su Hu ◽  
Wen Yang ◽  
Jian Mei Wang ◽  
Min Li ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Numerical Calculation ◽  
Transfer Coefficient ◽  
Stress Analysis ◽  
Surface Heat ◽  
Flow State ◽  
Surface Heat Transfer ◽  
Surface Heat Transfer Coefficient ◽  
Key Factor

With the development of the power grid, the proportion of large capacity unit is increasing rapidly. It requires a more in-depth study on the reliability of the unit, especially for the unit adjusting the peak. This paper concerned on the research of the surface heat transfer coefficient, which is the key factor affect the precision in thermal stress analysis. The surface heat transfer coefficient is obtained via the numerical calculation for the steam’s flow state and the transient heat transfer between rotor. This paper mainly describes the steam’s flow state and the transient heat transfer with the steam seal, and the results show that the direct numerical calculation is resultful in this subject.

Computational Study on Estimating the Surface Heat Transfer Coefficient of Absorber Tube in Solar Parabolic Trough Collector

2013 ◽  
Vol 446-447 ◽  
pp. 1546-1551
Author(s):  
Harshit Saxena ◽  
Arpit Santoki ◽  
Nimish Awalgaonkar ◽  
Arpan Jivani ◽  
Ganni Gowtham ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Solar Radiation ◽  
Computational Study ◽  
Surface Heat ◽  
Parabolic Trough ◽  
Flow Rates ◽  
Surface Heat Transfer Coefficient ◽  
Mass Flow Rates ◽  
The Given

Solar Parabolic Trough collectors are commonly used to harness the solar power for power generating applications involving high temperatures. In the given paper study we have made use of the SolTrace software which uses the Monte Carlo algorithm for finding out the radiation received on the absorber tube of the collector. The computational study was performed taking into account the solar radiation received at Vellore city in India (12.92oN, 79.13oE) as on 16th February 2013. Further a 3D model of the absorber tube used in the parabolic trough collector was created and meshed with the help of the Ansys Gambit software. The absorber tube which we considered for our study is made up of Stainless Steel AISI 302 material. The meshed model so created was then exported to the Ansys Fluent 6.3 software and simulations were performed for different mass flow rates of the fluid. The fluid which we used in the computational analysis study is Therminol 55. The temperature differences for different mass flow rates of the liquid passing through the absorber tube were found out and based on the temperature rise contours plots so obtained, we have plotted the surface heat transfer coefficient for the absorber tube. We also found out the static temperature contour plot for the fluid flowing through the given absorber tube taking into account the heat flux acting on the absorber tube due to the hourly and daily average solar radiation.

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