Abstract
Condenser thermal performances, such as the back pressure and venting rate, are strongly affected by the tube arrangement. Condensers have three irreversible processes for the fluid flow, heat transfer and mass diffusion. The condenser venting rate is studied here based on an air mass entransy analysis. The air mass entransy increment rate for the steam and air mixture on the condenser shell side is expressed as a function of the distributed air mass fraction and the steam condensation rate to define the relationship between the condenser venting rate and the flow parameters. Condensers with three typical tube arrangements were analyzed numerically using the porous medium model. The results show that a bigger venting rate always corresponds to a smaller air mass entransy increment rate. The air mass entransy generally decreases in the air concentration region and increases in the air cooling region under the combined action of the air diffusion and steam condensation. The numerical results indicate that the air cooling region of a condenser should be carefully designed and the cooling tubes should be properly arranged to guide the steam flow so as to weaken air concentration, and consequently to decrease the venting rate.
Similar content being viewed by others
References
Heat Exchange Institute (2006) Standards for steam surface condensers
Zhang C, Sousa A, Venart J (1991) Numerical simulation of different types of steam surface condensers. J Energy Resour-ASME 113:63–70
Zhang C, Sousa A, Venart J (1993) The numerical and experimental study of a power plant condenser. J Heat Trans-T ASME 115:435–445
Zhang C (1994) Numerical modeling using a quasi-3-dimensional procedure for large power plant condensers. J Heat Trans-T ASME 116:180–188
Malin MR (1997) Modelling flow in an experimental marine condenser. Int Commun Heat Mass 24:597–608
Zhang C, Bokil A (1997) A quasi-three-dimensional approach to simulate the two-phase fluid flow and heat transfer in condensers. Int J Heat Mass Transf 40:3537–3546
Sato K, Taniguchi A, Kamada T et al (1998) New tube arrangement of condenser for power stations. Fluids Therm Eng 41:752–758
Roy RP, Ratisher M, Gokhale VK (2001) A computational model of a power plant steam condenser. J Energy Resour-ASME 123:81–91
Ramon IS, Gonzalez MP (2001) Numerical study of the performance of a church window tube bundle condenser. Int J Therm Sci 40:195–204
Prieto MM, Suarez IM, Montanes E (2003) Analysis of the thermal performance of a church window steam condenser for different operational conditions using three models. Appl Therm Eng 23:163–178
Guo ZY, Zhu HY, Liang XG (2007) Entransy—a physical quantity describing heat transfer ability. Int J Heat Mass Transf 50:2545–2556
Wei SH, Chen LG, Sun FR (2008) “Volume-point” heat conduction constructal optimization with entransy dissipation minimization objective based on rectangular element. Sci China Ser E Technol Sci 51:1283–1295
Wei SH, Chen LG, Sun FR (2010) Constructal entransy dissipation minimisation for ‘volume-point’ heat conduction without the premise of optimised last-order construct. Int J Energy 7:627–639
Wei SH, Chen LG, Sun FR (2010) Constructal entransy dissipation minimization for “volume-point” heat conduction based on triangular element. Therm Sci 14:1075–1088
Xiao QH, Chen LG, Sun FR (2011) Constructal entransy dissipation rate minimization for “disc-to-point” heat conduction. Chin Sci Bull 56:102–112
Xiao QH, Chen LG, Sun FR (2011) Constructal entransy dissipation rate minimization for umbrella-shaped assembly of cylindrical fins. Sci China Tech Sci 54:211–219
Xie ZH, Chen LG, Sun FR (2011) Comparative study on constructal optimizations of t-shaped fin based on entransy dissipation rate minimization and maximum thermal resistance minimization. Sci China Tech Sci 54:1249–1258
Xiao QH, Chen LG, Sun FR (2011) Constructal entransy dissipation rate minimization for heat conduction based on a tapered element. Chin Sci Bull 56:2400–2410
Chen LG, Wei SH, Sun FR (2011) Constructal entransy dissipation rate minimization of a disc. Int J Heat Mass Transf 54:210–216
Meng JA, Liang XG, Li ZX (2005) Field synergy optimization and enhanced heat transfer by multi-longitudinal vortexes flow in tube. Int J Heat Mass Transf 48:3331–3337
Chen Q, Ren JX, Meng JA (2007) Field synergy equation for turbulent heat transfer and its application. Int J Heat Mass Transf 50:5334–5339
Chen Q, Ren JX (2008) Generalized thermal resistance for convective heat transfer and its relation to entransy dissipation. Chin Sci Bull 53:3753–3761
Chen Q, Wang MR, Pan N et al (2009) Optimization principles for convective heat transfer a-1150-2010, b-1315-2008. Energy 34:1199–1206
Wu J, Liang XG (2008) Application of entransy dissipation extremum principle in radiative heat transfer optimization. Sci China Ser E-Tech Sci 51:1306–1314
Guo JF, Cheng L, Xu MT (2009) Entransy dissipation number and its application to heat exchanger performance evaluation. Chin Sci Bull 54:2708–2713
Liu XB, Meng JA, Guo ZY (2009) Entropy generation extremum and entransy dissipation extremum for heat exchanger optimization. Chin Sci Bull 54:943–947
Xia SJ, Chen LG, Sun FR (2009) Optimization for entransy dissipation minimization in heat exchanger. Chin Sci Bull 54:3587–3595
Qian XD, Li ZX (2011) Analysis of entransy dissipation in heat exchangers. Int J Therm Sci 50:608–614
Qian XD, Li Z, Li ZX (2011) Entransy-dissipation-based thermal resistance analysis of heat exchanger networks. Chin Sci Bull 56:3289–3295
Guo JF, Xu MT, Cheng L (2011) The influence of viscous heating on the entransy in two-fluid heat exchangers. Sci China Tech Sci 54:1267–1274
Guo JF, Xu MT, Cheng L (2010) Principle of equipartition of entransy dissipation for heat exchanger design. Sci China Tech Sci 53:1309–1314
Li XF, Guo JF, Xu MT et al (2011) Entransy dissipation minimization for optimization of heat exchanger design. Chin Sci Bull 56:2174–2178
Chen Q, Wu J, Wang MR et al (2011) A comparison of optimization theories for energy conservation in heat exchanger groups. Chin Sci Bull 56:449–454
Chen Q, Ren JX, Guo ZY (2008) Field synergy analysis and optimization of decontamination ventilation designs. Int J Heat Mass Transf 51:873–881
Chen Q, Meng JA (2008) Field synergy analysis and optimization of the convective mass transfer in photocatalytic oxidation reactors. Int J Heat Mass Transf 51:2863–2870
Chen Q, Ren JX, Guo ZY (2008) Fluid flow field synergy principle and its application to drag reduction. Chin Sci Bull 53:1768–1772
Zeng H, Meng JA, Li ZX (2012) Analysis of condenser shell side pressure drop based on the mechanical energy loss. Chin Sci Bull 57:4718–4725
Yakhot V, Orszag SA (1986) Renormalization-group analysis of turbulence. Phys Rev Lett 57:1722–1724
Acknowledgements
The work was supported by the National Key Basic Research Program of China (2013CB228301) and the National Natural Science Foundation of China (51036003).
Author information
Authors and Affiliations
Corresponding author
About this article
Cite this article
Meng, J., Zeng, H. & Li, Z. Analysis of condenser venting rates based on the air mass entransy increases. Chin. Sci. Bull. 59, 3283–3291 (2014). https://doi.org/10.1007/s11434-014-0329-z
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s11434-014-0329-z