Entransy analysis on boiler air pre-heater with multi-stage LHS unit

Abstract Boiler air pre-heater with multi-stage LHS unit is investigated with entransy analysis. Optimum melting temperature match is derived. It is concluded that optimum melting temperature decreases alongside flow direction of flue gas. Optimum melting temperature at inlet increases with stage number, while that at outlet decreases. Temperature difference of PCMs in two nearby portions is the same but decreases with stage number. Entransy dissipation in LHS unit is compared with that in LHS unit. It is concluded that normalized entransy dissipation is not always reduced in LHS unit in the whole period, due to the decrease of heat transfer rate in SHS unit. However, entransy dissipation is always reduced in LHS unit, except single-stage unit, when heat storage amount is constrained. Reduction degree increases with stage number. Therefore, air pre-heater with multi-stage LHS unit is favored for recovery of waste heat in flue gas and improvement of boiler efficiency.

[1]  Zhen-Xiang Gong,et al.  Finite element analysis of a multistage latent heat thermal storage system , 1996 .

[2]  Viktoria Martin,et al.  Multistage latent heat cold thermal energy storage design analysis , 2013 .

[3]  Fengrui Sun,et al.  Constructal entransy dissipation rate minimization for solid–gas reactors with heat and mass transfer in a disc-shaped body , 2015 .

[4]  Yue Hu,et al.  New heat integration system with bypass flue based on the rational utilization of low-grade extraction steam in a coal-fired power plant , 2017 .

[5]  Sheng Li,et al.  Upgrading Low-temperature Steam to Match CO2 Capture in Coal-fired Power Plant Integrated with Double Absorption Heat Transformer , 2017 .

[6]  Luisa F. Cabeza,et al.  Review on thermal energy storage with phase change: materials, heat transfer analysis and applications , 2003 .

[7]  Pablo Eguía,et al.  A simplified method for modeling the thermal performance of storage tanks containing PCMs , 2016 .

[8]  C. Wang,et al.  Optimization of double-stage latent heat storage unit in whole cycle with entransy analysis , 2017 .

[9]  Mingtian Xu,et al.  The Application of Entransy Dissipation Theory in Optimization Design of Heat Exchanger , 2012 .

[10]  Defu Che,et al.  Thermal deformation prediction based on the temperature distribution of the rotor in rotary air-preheater , 2015 .

[11]  Lin Cheng,et al.  Optimization design based on the thermal resistance analyses of heat recovery systems for rotary kilns , 2017 .

[12]  XueTao Cheng,et al.  Radiative entransy flux in enclosures with non-isothermal or non-grey, opaque, diffuse surfaces and its application , 2011 .

[13]  Fengrui Sun,et al.  Constructal entransy dissipation rate minimization for triangular heat trees at micro and nanoscales , 2015 .

[14]  Xianting Li,et al.  A Deep Heat Recovery Device between Flue Gas and Supply Air of Gas-fired Boiler by Using Non-contact Total Heat Exchanger , 2017 .

[15]  Ming Liu,et al.  Investigation on the off-design performances of flue gas pre-dried lignite-fired power system integrated with waste heat recovery at variable external working conditions , 2015 .

[16]  Zhixin Li,et al.  Optimization of flue gas turbulent heat transfer with condensation in a tube , 2011 .

[17]  Zhixin Li,et al.  Optimization of flue gas convective heat transfer with condensation in a rectangular channel , 2011 .

[19]  Gennady Ziskind,et al.  Analysis and optimization of melting temperature span for a multiple-PCM latent heat thermal energy storage unit , 2016 .

[20]  Ruzhu Wang,et al.  Review of Recent Patents on Chemical Heat Pump , 2008 .

[21]  W. Tao,et al.  Performance optimization of two-stage latent heat storage unit based on entransy theory , 2014 .

[22]  Fengrui Sun,et al.  Constructal design for blast furnace wall based on the entransy theory , 2016 .

[23]  Ruzhu Wang,et al.  Investigation of solid–gas reaction heat transformer system with the consideration of multistep reactions , 2008 .

[24]  Changying Zhao,et al.  Thermodynamic analysis and optimization of cascaded latent heat storage system for energy efficient utilization , 2015 .

[25]  Jian Sun,et al.  New district heating system based on natural gas-fired boilers with absorption heat exchangers , 2017 .

[26]  Ruzhu Wang,et al.  Performance of solid–gas reaction heat transformer system with gas valve control , 2010 .

[27]  Qun Chen,et al.  Entransy dissipation-based constraint for optimization of heat exchanger networks in thermal systems , 2015 .

[28]  P. Feron,et al.  Simultaneous heat and water recovery from flue gas by membrane condensation: Experimental investigation , 2017 .

[29]  Ratchaphon Suntivarakorn,et al.  Improvement of Boiler's Efficiency Using Heat Recovery and Automatic Combustion Control System , 2016 .

[30]  Fengrui Sun,et al.  Entransy dissipation minimization for generalized heat exchange processes , 2016 .

[31]  Bo Zhang,et al.  Application of field synergy principle for optimization fluid flow and convective heat transfer in a tube bundle of a pre-heater , 2014 .

[32]  M. Farid,et al.  Performance of direct contact latent heat storage units with two hydrated salts , 1994 .

[33]  Ebrahim Hajidavalloo,et al.  Three-dimensional simulation of rotary air preheater in steam power plant , 2014 .

[34]  XinGang Liang,et al.  Entransy—A physical quantity describing heat transfer ability , 2007 .

[35]  Yi Jiang,et al.  Exergy and entransy analyses in air-conditioning system part 1—Similarity and distinction , 2016 .

[37]  XinGang Liang,et al.  Application of entransy dissipation extremum principle in radiative heat transfer optimization , 2008 .

[38]  Maciej Jaworski,et al.  Experimental investigation of thermoelectric generator (TEG) with PCM module , 2016 .

[39]  Tao Yu.  Application of Entransy Dissipation Theory in Optimization of Latent Heat Storage Process , 2014 .

[40]  Ming Li,et al.  Effective thermal conductivity of open-cell metal foams impregnated with pure paraffin for latent heat storage , 2014 .

[41]  Jiateng Zhao,et al.  Experimental investigation on thermal performance of phase change material coupled with closed-loop oscillating heat pipe (PCM/CLOHP) used in thermal management , 2016 .