Mathematical modeling and analysis of steady state performance of a heat pipe network

Abstract In the current study, the thermal-fluid phenomenon inside a heat pipe network is simulated numerically. The heat pipe is specially configured to be implemented in thermal energy storage units for a concentrating solar power system. It composed of a main heat pipe and an array of secondary heat pipes. The applied thermal energy to the disc-shaped evaporator is transferred to the heat engine by the primary heat pipe. The extra heat is delivered to the phase change material through the concentric secondary heat pipes. The vapor flow leaving the adiabatic pipe section of the primary heat pipe to the disc-shaped condenser behaves similarly to the confined jet impingement. Therefore, the condensation is not uniform over the main condenser. In order to model the physical phenomenon inside the heat pipe network, a new numerical procedure was developed. The feature that makes the procedure distinguished from other available techniques is its ability to simulate non-uniform condensation of the working fluid in the condenser section. The vapor jet impingement on the condenser surface along with condensation was modeled by attaching a porous layer adjacent to the condenser wall. This porous layer acts as a wall and let the vapor flow to split out radially while it allows mass transfer through it. The effects on the pressure and temperature distributions from the heat input, portion of heat transferred to the phase change material, main condenser geometry and secondary heat pipe configurations have been investigated. The result showed that the temperature distributions of main and secondary heat pipes are greatly affected by the geometrical features. The formed recirculation zones in the main condenser region, which depend on geometrical parameters, make the performance of heat pipes convoluted. For the case with one secondary heat pipe, placing it away from the primary heat pipe provides higher temperatures at the primary and the secondary heat pipes. It also yields more uniform temperature at the main condenser. For cases with two and three secondary heat pipes, the temperature of the secondary heat pipes highly depends on the secondary heat pipes position and the ratio of heat transfer to the PCM.

[1]  K. Sopian,et al.  Internal and external fin heat transfer enhancement technique for latent heat thermal energy storage in triplex tube heat exchangers , 2013 .

[2]  Charles J. Hoogendoorn,et al.  Vapor Flow Calculations in a Flat-Plate Heat Pipe , 1979 .

[3]  Amir Faghri,et al.  A three-dimensional thermal-fluid analysis of flat heat pipes , 2008 .

[4]  Jung-Chang Wang.  L-type heat pipes application in electronic cooling system , 2011 .

[5]  Amir Faghri,et al.  Performance characteristics of cylindrical heat pipes with multiple heat sources , 2011 .

[6]  Songgang Qiu,et al.  Phase Change Material Thermal Energy Storage System Design and Optimization , 2013 .

[7]  Pradit Terdtoon,et al.  Effect of capillary pressure on performance of a heat pipe: Numerical approach with FEM , 2012 .

[8]  Vapor Flow in Cylindrical Heat Pipes , 1973 .

[9]  S. Kumar,et al.  Numerical simulation of cylindrical heat pipe considering non-Darcian transport for liquid flow inside wick and mass flow rate at liquid–vapor interface , 2014 .

[10]  E. Levy.  Theoretical Investigation of Heat Pipes Operating at Low Vapor Pressures , 1968 .

[11]  Amir Faghri,et al.  Heat Pipe Science And Technology , 1995 .

[12]  Manish K. Rathod,et al.  Thermal performance enhancement of shell and tube Latent Heat Storage Unit using longitudinal fins , 2015 .

[13]  John Goldak,et al.  Three-dimensional numerical analysis of heat and mass transfer in heat pipes , 2007 .

[14]  Jung-Chang Wang,et al.  U- and L-shaped heat pipes heat sinks for cooling electronic components employed a least square smoothing method , 2014, Microelectron. Reliab..

[15]  Amir Faghri,et al.  An analysis of the vapor flow and the heat conduction through the liquid-wick and pipe wall in a heat pipe with single or multiple heat sources , 1990 .

[16]  Zhuo Li,et al.  Numerical study on the thermal behavior of phase change materials (PCMs) embedded in porous metal matrix , 2014 .

[17]  A. Faghri,et al.  Conjugate Modeling of High-Temperature Nosecap and Wing Leading Edge Heat Pipes , 1993 .

[18]  E. Jung,et al.  Thermal analytical model of latent thermal storage with heat pipe heat exchanger for concentrated solar power , 2014 .

[19]  Adriano Sciacovelli,et al.  Maximization of performance of a PCM latent heat storage system with innovative fins , 2015 .

[20]  Mahboobe Mahdavi,et al.  Numerical investigation of hydrodynamics and thermal performance of a specially configured heat pipe for high-temperature thermal energy storage systems , 2015 .

[21]  Chakravarthy Balaji,et al.  Experimental investigations on thermal performance enhancement and effect of orientation on porous matrix filled PCM based heat sink , 2013 .

[22]  A. Faghri,et al.  Experimental and Numerical Analysis of Low-Temperature Heat Pipes With Multiple Heat Sources , 1991 .

[23]  Yu.F. Maydanik,et al.  Copper–water loop heat pipes for energy-efficient cooling systems of supercomputers , 2014 .

[24]  Leonard L. Vasiliev,et al.  Heat pipes in modern heat exchangers , 2005 .

[25]  S. Tiari,et al.  Numerical study of finned heat pipe-assisted thermal energy storage system with high temperature phase change material , 2015 .

[26]  Tănase Dobre,et al.  Characterization of cooling systems based on heat pipe principle to control operation temperature of high-tech electronic components , 2010 .

[27]  Amir Faghri,et al.  Numerical analysis of laminar flow in a double-walled annular heat pipe , 1987 .

[28]  K. Vafai,et al.  Analysis of Asymmetric Disk-Shaped and Flat-Plate Heat Pipes , 1995 .

[29]  Masataka Mochizuki,et al.  Numerical analysis and experimental verification on thermal fluid phenomena in a vapor chamber , 2006 .

[30]  E. Jung,et al.  Thermal numerical model of a high temperature heat pipe heat exchanger under radiation , 2014 .

[31]  S. Tiari,et al.  Numerical investigation of high temperature heat pipe incorporated in thermal energy storage systems , 2014 .

[32]  A. Elgafy,et al.  Numerical Study for Enhancing the Thermal Conductivity of Phase Change Material (PCM) Storage using High Thermal Conductivity Porous Matrix , 2005 .

[33]  Amir Faghri,et al.  Analysis of flat heat pipes with various heating and cooling configurations , 2011 .

[34]  Yiding Cao,et al.  TRANSIENT TWO-DIMENSIONAL COMPRESSIBLE ANALYSIS FOR HIGH-TEMPERATURE HEAT PIPES WITH PULSED HEAT INPUT , 1991 .

[35]  Jong Heung Park Park,et al.  A Study on Thermal Performance of Heat Pipe for Optimum Placement of Satellite Equipment , 1997 .

[36]  I. V. Yagodkin,et al.  Physical principles of heat pipes , 1982 .

[37]  Amir Faghri,et al.  Simulation of heat pipe-assisted latent heat thermal energy storage with simultaneous charging and discharging , 2015 .