Evaluation of the effectiveness-NTU method for countercurrent humidifier

Abstract An analytical method is advantageous in designing and optimizing the humidifier of the humid air turbine cycle. In this paper, the energy effectiveness-NTU model for the countercurrent humidifier is built and verified by the 141 groups of test data obtained from an experimental facility of pressurized packing humidifier. The effect of pressure and inlet conditions including water/air mass flow rate ratio, inlet water temperature and inlet air wet bulb temperature on the heat capacity rate ratio and the energy effectiveness is analyzed. A sensitivity analysis is performed in order to indicate the key inlet parameter to improve the energy effectiveness of countercurrent humidifier. It is shown that the maximum deviation of the energy effectiveness calculated by the analytical method is 22.7% comparing to the experimental data. However, the maximum deviation is not more than 16% when considering the actual operating conditions for the humidifier of heat capacity rate ratio being greater than1.5. Heat capacity rate ratio changes monotonically with pressure and inlet parameters, and the energy effectiveness has an inflection point of minimum value when heat capacity rate ratio is equal to 1. Sensitivity analysis shows that water/air mass flow rate ratio is the most critical factor.

[1]  Boris Halasz,et al.  Application of a general non-dimensional mathematical model to cooling towers , 1999 .

[2]  A. Wexler,et al.  FORMULATIONS FOR THE THERMODYNAMIC PROPERTIES OF THE SATURATED PHASES OF H2O FROM 173.15 TO 473.15 K. , 1983 .

[3]  Svend Bram,et al.  New concept of spray saturation tower for micro Humid Air Turbine applications , 2014 .

[4]  Shilie Weng,et al.  Experimental investigation of pressurized packing saturator for humid air turbine cycle , 2014 .

[5]  A. London,et al.  Compact heat exchangers , 1960 .

[6]  Ralph L. Webb,et al.  Design of Cooling Towers by the Effectiveness-NTU Method , 1989 .

[7]  Detlev G. Kro¨ger,et al.  Cooling tower performance evaluation: Merkel, Poppe, and e-NTU methods of analysis , 2005 .

[8]  Alberto Traverso,et al.  Implementation and experimental validation of a modeling tool for humid air turbine saturators , 2011 .

[9]  Hidefumi Araki,et al.  Design Study of a Humidification Tower for the Advanced Humid Air Turbine System , 2005 .

[10]  Alberto Traverso,et al.  Experimental analysis of pressurised humidification tower for humid air gas turbine cycles. Part A: Experimental campaign , 2008 .

[11]  John H. Lienhard,et al.  ENERGY EFFECTIVENESS OF SIMULTANEOUS HEAT AND MASS EXCHANGE DEVICES , 2010 .

[12]  Yingchun Xie,et al.  Hydrodynamic and heat and mass transfer performances of novel ceramic foam packing to humidification tower , 2015 .

[13]  R. Hyland,et al.  Formulations for the thermodynamic properties of dry air from 173.15 K to 473.15 K, and of saturated moist air from 173.15 K to 372.15 K, at pressures to 5 MPa , 1983 .

[14]  Paul N. Cheremisinoff,et al.  Cooling towers: Selection, design, and practice , 1981 .

[15]  Alberto Traverso,et al.  Saturator analysis for an evaporative gas turbine cycle , 2003 .

[16]  Marcus Thern,et al.  Experimental and Theoretical Results of a Humidification Tower in an Evaporative Gas Turbine Cycle Pilot Plant , 2002 .

[17]  Martin Belusko,et al.  An effectiveness-NTU technique for characterising tube-in-tank phase change thermal energy storage systems , 2012 .

[18]  Tomomi Koganezawa,et al.  Test Results From the Advanced Humid Air Turbine System Pilot Plant: Part 2—Humidification, Water Recovery and Water Quality , 2008 .

[19]  Martin Belusko,et al.  An effectiveness-NTU model of a packed bed PCM thermal storage system , 2014 .

[20]  Chengqin Ren,et al.  Corrections to the simple effectiveness-NTU method for counterflow cooling towers and packed bed liquid desiccant–air contact systems , 2008 .

[21]  Zhen Xu,et al.  Experimental and Theoretical Studies on Air Humidification by a Water Spray for Humid Air Turbine Cycle , 2006 .