Numerically-based parametric analysis of plain fin and tube compact heat exchangers

Abstract

In the present study, the hydrodynamic and heat transfer characteristics of six-tube-row compact fin and tube heat exchangers have been investigated numerically by introducing a methodology of analysis based on local and global energy balances, from three-dimensional velocity and temperature fields. The aim is to analyze the influence of operating conditions and the geometry to design more efficient devices. Tube diameter, fin spacing and tube layout are the geometrical parameters; the over-tube fluid velocity, via Reynolds number, is used as the parameter of operation. Using the procedure, along with the concept of fraction of the total heat rate available for the specific device, the results have shown that, fluid velocity plays an important role, whereas the role of tube layout is minor, and that the effects of tube diameter and fin spacing being closely related to the magnitude of the fluid velocity. For small velocities, 99% of the heat rate that could be potentially achieved occurs closer to the inlet of the device, whereas for large velocity-values, nearly the entire length is necessary. In addition, the influence of the tube-diameter on both heat transfer and pressure drop is negligible at small velocities but progressively increases at bigger velocity-values; a similar -but less pronounced-effect is produced by fin spacing, where the influence of tubediameter is relevant only for larger fin spacings. The approach introduced here is useful in providing, at the expense of some generality, high accuracy and clear information on the thermal convection process in these devices, since intermediate steps via Nusselt numbers and heat transfer coefficients are not needed.

Cooling system optimization for a terahertz radiation detector via parametric analysis of the fluid-solid interaction problem

“…The governing equations were discretized on the computational domain, which is the minimum required to accurately resemble the entire system and ensure accurate results while maintaining a manageable CPU time [26,27]. for both the fluid flow inside the channel and the TLC-Mylar layer, and solved by the well-known finite element method using the general software COMSOL Multiphysics (http://www.comsol.com).…”

Optimisation of Thermal and Geometric Parameters of Cylindrical Fins during Natural Convection

“…More precisely, the melting and solidification processes have been numerically studied to determine an accurate model for describing the charging and discharging of the system. The study presented in [17] conducts a numerical investigation of the hydrodynamics and heat transfer of a six-tube-row compact fin and tube heat exchangers. The aim of the analysis was to identify the interaction between the geometry and the operating conditions to design more efficient devices.…”

Numerical Study of Fin-and-Tube Heat Exchanger in Low-Pressure Environment: Air-Side Heat Transfer and Frictional Performance, Entropy Generation Analysis, and Model Development

“…It was found that fin tubes at the downstream region contribute to high heat exchange efficiency. Based on the local and global energy balances analysis method, Cobian-Iñiguez et al [ 14 ] developed a 3D model to study the characteristic of compact finned tube heat sink with six tube rows. Their study emphasized the influence of operating conditions and the geometry and reporting changes in flow velocity considerably affected temperature fields and thermal performance.…”

“…5.86 (0 kPa < p < 25 kPa)(13) h = 2.2895(p/p 0 ) −0.0328 Re 0.7816 Pr 8.39 (25 kPa ≤ p < 101 kPa)(14) where p is equal to the environment pressur, and p 0 is the normal pressure of 101 kPa. = 0.04588Re −0.1425 (p/p 0 )0.0134 (200 < Re < 11136) (16) f = 76.4078Re −0.99738 (p/p 0 ) −0.01076 (Re < 500) (17) f = 2.8069Re −0.47 (p/p 0 ) −0.0063 (500 ≤ Re < 11136)…”