Modares Mechanical Engineering

Modares Mechanical Engineering

Parametric study of a rectangular single phase natural circulation loop at steady state

Authors
Seyyed Masoud Seyyedi 1
Mehdi Hashemi-Tilehnoee 2
1 Department of Mechanical Engineering, Aliabad Katoul Branch, Islamic Azad University, Aliabad Katoul, Iran
2 Department of Nuclear Engineering, Aliabad Katoul Branch, Islamic Azad Univerity, Aliabad Katoul, Iran
Abstract
A natural circulation loop receives heat from a high-temperature source and rejects it to a low-temperature source without using a mechanical pump. Single phase natural circulation loop has been applied in many industrial systems for cooling. The heat transport capability of natural circulation loops (NCLs) is directly proportional to the flow rate that it can generate. To establish the heat transport capability of a natural circulation loop, it is essential to know the flow rate. Friction force and gravitational force are balanced with each other along the loop at steady state. In this paper, firstly the governing equations have been written for a natural circulation loop. Then the governing equations have been rewritten in the dimensionless form. Then, effects of heater length, cooler length, tube diameter, loop height, loops inclination angle, the distance of heater from the right side or left side, the distance of cooler from right or left sides and power of the heater on the loop mass flow rate and loop temperature distribution have been investigated. The results show that increasing of loop height, loop diameter and power of heater increase the mass flow rate. Also, increasing or decreasing of heater length, has no effect on the mass flow rate, whereas increasing of loop inclination angle decreases the mass flow rate. In this study, the friction coefficient is considered as continues for all regimes. In addition, the position of the heater and cooler has been unsymmetrically investigated.
Keywords
Natural circulation loop
Single phase
Mass flow rate
Heater Power
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Modares Mechanical Engineering
Volume 18, Issue 2
April 2018
Pages 413-422