Modeling of the Compression Process for Refrigerants R134a and R1234yf of a Variable Speed Reciprocating Compressor
Keywords:Vapour compression, refrigeration, energy, thermodynamic analysis.
This paper presents a robust computational model to predict the behavior of a variable speed reciprocatingcompressor, incorporating infinitesimal displacements to calculate state by state according to the piston movement. Thephilosophy of the model is to consider eight sub internal processes: heat transfer on the suction and discharge internallines, pressure drop across the suction and discharge valves, expansion, suction, compression and discharge. The inputvariables are: pressure and temperature on the suction (before starting the compression process), discharge pressure(after the compression process completed) and rotation speed, with this the model is able to compute the outputparameters like: mass flow rate, power consumption and discharge temperature. With the development of the model, thebehaviors of R1234yf and R134a are analyzed. Then the model is validated with experimental data using these bothrefrigerants, concluding that the model predict with an error of Â±10% for the mass flow rate and power consumption, andwith an error of Â±1 K for the discharge temperature. In the validation, differences in energy behavior for the tworefrigerants are discussed; the compressor with R1234yf as working fluid increases its power consumption and deliversgreater mass flow rate with low temperature compared when the working fluid on the compressor is R134a.
Minor B, Spatz M. HFO-1234yf Low GWP Refrigerant Update. International Journal and Air Conditioning Conference 2008; pp 1-8.
Akasaka R, Tanaka K, Higashi Y. Thermodynamic property modeling for 2,3,3,3 tetrafluoropropene (HFO-1234yf). International Journal of Refrigeration 2010; 33: pp 52-60. http://dx.doi.org/10.1016/j.ijrefrig.2009.09.004
Tanaka K, Higashi Y. Thermodynamic properties of HFO- 1234yf (2,3,3,3-tetrafluoropropane). International Journal of Refrigeration 2010; 33: pp 474-479. http://dx.doi.org/10.1016/j.ijrefrig.2009.10.003
Lai N, Vrabec J, Raabe G, Fischer J, Wendland M. Description of HFO-1234yf with BACKONE equation of state. Fluid Phase Equilibria 2011; 305: pp 2014-2020. http://dx.doi.org/10.1016/j.fluid.2011.04.005
Zilio C, Steven B, Schichet G, Cavallini A. The refrigerant R1234yf in air conditioning systems. Energy 2011; 36: pp 6110-6120. http://dx.doi.org/10.1016/j.energy.2011.08.002
Navarro E, Mendoza J, Mota A, Barragán A, Belman JM. Experimental analysis of R1234yf as a drop-in replacement or R134a in a vapor compression system. International Journal of Refrigeration 2013; 36: pp 870-880. http://dx.doi.org/10.1016/j.ijrefrig.2012.12.014
Navarro E, Molés F, Barragán C. Experimental analysis of the internal heat exchanger influence on a vapour compression system performance working with R1234yf as a drop-in replacement for R134a. Applied Thermal Engineering 2013; 59: pp 153-161. http://dx.doi.org/10.1016/j.applthermaleng.2013.05.028
Ledesma S, Belman-Flores JM. Application of artificial neural networks for generation of energetic maps of a variable speed compression system working with R1234yf. Applied Thermal Engineering 2014; 69: pp 105-112. http://dx.doi.org/10.1016/j.applthermaleng.2014.04.050
Damle R, Rigola J, Pérez C, Castro J, Oliva A. Objectoriented simulation of reciprocating compressors: Numerical verification and experimental comparison. International Journal of Refrigeration 2011; 34: pp 1989-1998. http://dx.doi.org/10.1016/j.ijrefrig.2011.02.006
Rigola J, Pérez CD, Oliva A. Parametric studies on hermetic reciprocating compressors. International Journal of Refrigeration 2005; 28: pp 253-266. http://dx.doi.org/10.1016/j.ijrefrig.2004.06.013
Peskin A. The effects of different property models in a computational fluid dynamics simulation of a reciprocating compressor. International Journal of Thermophysics 1999; 20: pp 175-186. http://dx.doi.org/10.1023/A:1021442616990
Matos F, Prata A, Deschamps C. A numerical methodology for the analysis of valve dynamics. Proceedings of the International Compressor Engineering Conference. Purdue 2000; 391-396.
Libera, Faraon, Solari. A complete analysis of dynamic behavior of hermetic compressor cavity to improve the muffler design. Proceedings of the International Compressor Engineering Conference. Purdue 2000; pp 665-669.
Ma Y, Min O. On study of pressure pulsation using a modified Helmholtz method. Proceedings of the International Compressor Engineering Conference. Purdue 2000; pp 657- 664.
Gonzalves J, Hermes C, Melo C, Knaben F. A simplified steady state model for prediction the energy consumption of household refrigerators and freezers. International Refrigeration and Air Conditioning Conference at Purdue 2008; pp 1-9.
Navarro E, Granryd E, Urchueguía JF, Corberán J. A phenomenological model for analyzing reciprocating compressors. International Journal of Refrigeration 2007; 30: pp 1254-1265. http://dx.doi.org/10.1016/j.ijrefrig.2007.02.006
Navarro E, Granryd E, Urchueguía JF, Corberán J. Performance analysis of a series of hermetic reciprocating working with R290 (propane) and R407C. International Journal of Refrigeration 2007; 30: pp 1254-1265. http://dx.doi.org/10.1016/j.ijrefrig.2007.02.006
Duprez M, Dumont E, Frere M. Modelling of reciprocating and scroll compressors. International Journal of Refrigeration 2007; 30: pp 873-886. http://dx.doi.org/10.1016/j.ijrefrig.2006.11.014
Wynandi E, Saavedra O, Lebrun J. Simplified modelling of an open type reciprocating compressor. International Journal of Thermal Science 2002; 41: pp 183-192. http://dx.doi.org/10.1016/S1290-0729(01)01296-0
Yang B, Bradshaw C, Groll E. Modeling of a semi-hermetic CO2 reciprocating compressor including lubrication submodels for piston rings and bearings. International Journal of Refrigeration 2012; 30: pp 1-13.
Fagotti, Prata. A New Correlation for Instantaneous Heat Transfer Between Gas and Cylinder in Reciprocating Compressors. International Compressor Engineering Conference, Purdue 1998; pp 871-876.
Disconzi F, Deschamps C, Pereira E. Development of an In- Cylinder Heat Transfer Correlation for Reciprocating Compressors. International Compressor Engineering Conference, Purdue 2012; pp 1-10.
Adair R, Qvale E, Pearson J. Instantaneous heat transfer to the cylinder wall in reciprocating compressors. International Compressor Engineering Conference, Purdue 1972; pp 521-526.
Incropera FP, Dewitt DP, Bergman TL, Lavine AS. Introduction to Heat Transfer. 5th Edition. John Wiley and Sons 2007.
Petukhov BS, Popov VN. Theoretical calculation of heat exchange and frictional resistance in turbulent flow in tubes of an incompressible fluid with variable physical properties (Heat exchange and frictional resistance in turbulent flow of liquids with variable physical properties through tubes). High Temperature 1963; 1: pp 69-83.
Hanne E. Tetchiness Thermodynamic. Addison-Wesley Publishing Company. Bonn. 2nd Edition 1993.