Termodinámica

 

Thermophysical properties of R744 in supercritical region during the startup of gas cooling process

 

Propiedades termofísicas del R744 en la región supercrítica durante el proceso del arranque del gas cooler

 

J.F. Ituna-Yudonago and J.M. Belman-Flores*

 

Department of Mechanical Engineering, Engineering Division, Campus Irapuato-Salamanca, Universidad de Guanajuato, Salamanca, Gto., Mexico. *Corresponding author. E-mail: jfbelman@ugto.mx

 

Received April 19, 2014
Accepted february 23, 2015

 

Abstract

In this paper, the thermophysical properties of carbon dioxide (R744) in supercritical region during the startup of gas cooling process were widely investigated in a horizontal hairpin gas cooler. The dynamic model was discretized by the fully implicit finite volume method. The thermophysical properties were evaluated through the REFPROP dynamic libraries linked to Matlab. The results showed that, the thermophysical properties of R744 are characterized by large variations along the gas cooler during the transient period. In the pseudo-critical region, the behavior of the specific heat, thermal conductivity, density and dynamic viscosity is characterized by an instantaneous change in the amplitude. The specific heat is the property most affected by the transient phenomenon in the gas cooler. Its behavior has a great impact on the local heat transfer coefficient of R744.

Key words: gas cooler, carbon dioxide, thermophysical properties, transient phenomenon, transcritical system.

 

Resumen

En este trabajo, se investigan ampliamente las propiedades termofísicas del dióxido de carbono (R744) en la región supercrítica durante el arranque del proceso de enfriamiento de gas, en un enfriador horizontal de tipo horquilla. El modelo dinámico fue discretizado mediante el método de volúmenes finitos completamente implícito. Las propiedades termofísicas se evaluaron a través de las bibliotecas dinámicas REFPROP vinculadas a Matlab. Los resultados mostraron que, las propiedades termofísicas del R744 se caracterizan por grandes variaciones a lo largo del enfriador de gas durante el período transitorio. En la región pseudo-crítica, el comportamiento del calor específico, conductividad térmica, densidad y viscosidad dinámica se caracteriza por un cambio instantáneo en la amplitud. El calor específico es la propiedad más afectada por el fenómeno transitorio en el enfriador de gas. Su comportamiento tiene un gran impacto en el coeficiente de transferencia de calor local del R744.

Palabras clave: enfriador de gas, dióxido de carbono, propiedades termofísicas, fenómeno transitorio, sistema transcrítico.

 

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References

Adam-Medina M., Escobar, R.F., Juárez-Romero, D., Guerrero-Ramírez, G.V., López-Zapata, B., (2013). Fault detection in a heat exchanger using second order sliding mode observers. Revista Mexicana de Ingeniería Química 12, 327-336.         [ Links ]

ASHRAE. (2009). Position Document on Natural Refrigerants, Carbon Dioxide, R744, 4. Available from: http://www2.epa.gov/sites/production/files/documents/ASHRAE_PD_Natural_Refrigerants_2011.pdf        [ Links ]

Belman-Flores, J.M. Gallegos-Muñoz, A., Riesco-Ávila, J.M., Zaleta-Aguilar, A., Mendoza-Miranda, J.M., (2014). Exergetic analysis of a refrigeration system. Revista Mexicana de Ingeniería Química 13, 957-968.         [ Links ]

Björn, P., (2008). Ammonia in low capacity refrigeration and heat pump systems. International Journal of Refrigeration 31, 709-715.         [ Links ]

Bolaji, B.O., Huan, Z., (2013). Ozone depletion and global warming: Case for the use of natural refrigerant - a review. Renewable and Sustainable Energy Reviews 18, 49-54.         [ Links ]

Butler, D.J.G., Gigiel, A., Russell, S., (2001). Using air for cooling, Building Research Establishment, BRE Publication Draft number 202-296.         [ Links ]

Cariaga, E., Vergara-Fernandez, A., Levano, M., Vergaray, N., (2013). Numerical simulation of the water saturation at the interface between homogeneous porous medium. Revista Mexicana de Ingeniería Química 12, 527-539.         [ Links ]

Chen, I.Y., Wang, C.C., Lin, S. Y., (2004). Measurements and correlations of frictional single-phase and two-phase pressure drops of R-410A flow in small U-type return bends. International Journal of Heat and Mass Transfer 47, 2241-2249.         [ Links ]

Churchill, S.W., (1977). Friction-factor equation spans all fluid flow regimes. Chemical Engineering Science 7, 91-92.         [ Links ]

Dang, C., Hihara, E., (2010). Numerical study on in tube laminar heat transfer of supercritical fluids. Applied Thermal Engineering 30, 1567-1573.         [ Links ]

Duffey, R.B., Pioro, I.L., (2005). Experimental heat transfer of supercritical carbon dioxide flowing inside channels (survey). Nuclear Engineering and Design 235, 913-924.         [ Links ]

Dull, D., Seidel, S., Wells, J., (1989). Moving Forward: Key Implications of the Montreal Protocol. Studies in Environmental Science 35, 775-784.         [ Links ]

Fang, X., Xu, Y., (2011). Modified heat transfer equation for in-tube supercritical CO₂ cooling. Applied Thermal Engineering 31, 3036-3042.         [ Links ]

Ge, Y.T., Cropper, R.T., (2009). Simulation and performance evaluation of finned-tube CO2 gas coolers for refrigeration systems. Applied Thermal Engineering 29, 957-965.         [ Links ]

Gnielinski, V., (1976). New equations for heat and mass transfer in turbulent pipe and channel flow. Int. Chem. Eng. 16, 359-68.         [ Links ]

Granryd, E., (2001). Hydrocarbons as refrigerants - an overview. International Journal of Refrigeration 24, 15-24.         [ Links ]

Hoo-Kyu, O., Chang-Hyo, S., (2010). New correlation to predict the heat transfer coefficient in-tube cooling of supercritical CO2 in horizontal macro-tubes. Experimental Thermal and Fluid Science 34, 1230-1241.         [ Links ]

Huai, X.L., Koyama, S., Zhao, T.S., (2005). An experimental study of flow and heat transfer of supercritical carbon dioxide in multi-port mini channels under cooling conditions. Chemical Engineering Science 60, 3337-3345.         [ Links ]

Kim, J.K., Jeon, H.K., Lee, J.S., (2007). Wall temperature measurement and heat transfer correlation of turbulent supercritical carbon dioxide flow in vertical circular/non-circular tubes. Nuclear Engineering and Design 237, 1795-1802.         [ Links ]

Kim, M.H., Pettersen, J., Bullard, C.W., (2004). Fundamentals process and system design issues in CO₂ vapor compression systems. Progress in Energy Combustion Science 30, 119-174.         [ Links ]

Lachner, B.F.J., Nellis, G.F., Reindl, D.T., (2007). The commercial feasibility of the use of water vapor as a refrigerant. International Journal of Refrigeration 30, 699-708.         [ Links ]

Lemmon, E.W., McLinden, M.O., Huber, M.L., (2007). REFPROP NIST Standard Reference Database 23, v. 8.0. National Institute of Standards; Gaithersburg, Maryland 20899, USA.         [ Links ]

Liao, S.M., Zhao, T.S., (2002). An experimental investigation of convection heat transfer to supercritical carbon dioxide in miniature tubes. International Journal of Heat and Mass Transfer 45, 5025-5034.         [ Links ]

Li., H., Kruizenga, A., Anderson, M., Corradini, M., Luo, Y., Wang, H., Li, H., (2011). Development of a new forced convection heat transfer correlation for CO₂ in both heating and cooling modes at supercritical pressures. International Journal ofThermal Sciences 50, 2430-2442.         [ Links ]

Lugo-Leyte, R., Salazar-Pereyra, M., Ruíz-Ramírez, O.A., Zamora-Mata, J.M., Torres-González, E.V. (2013). Exergoeconomic operation cost analysis to theoretical compression refrigeration cycle of HFC-134a. Revista Mexicana de Ingeniería Química 12, 361-370.         [ Links ]

Neil, A.R., Owen R.C., (2004). Energy saving refrigerant blends comprising R125, R134a, R600 or R600a. International Refrigeration and Air Conditioning Conference, 632.         [ Links ]

Park, C.Y., Hrnjak, P., (2007). Effect of heat conduction through the fins of a microchannel serpentine gas cooler of transcritical CO₂ system. International Journal of Refrigeration 30, 389-397.         [ Links ]

Patankar, V., Suhas, (1980). Numerical heat transfer and fluid flow. Hemisphere Publishing Corporation. USA.         [ Links ]

Peixue, J., Chenru, Z., Jianqiang, D., Wenxing, Z., (2008). Experimental Investigation of Local Heat Transfer of Carbon Dioxide at Super-Critical Pressures in a Vertical Tube and Multi-Port Mini-Channels Under Cooling Conditions. International Refrigeration and Air Conditioning Conference, Paper 892.         [ Links ]

Pérez-García, V., Belman-Flores, J.M., Navarro-Esbrí, J., Rubio-Maya, C., (2013). Comparative study of transcritical vapor compression configurations using CO₂ as refrigeration mode base on simulation. Applied Thermal Engineering 51, 1038-1046.         [ Links ]

Petukhov, B.S., Popov,VN., (1963). Theoretical calculation of heat exchanger and frictional resistance in turbulent flow in tubes of incompressible fluid with variable physical properties. High Temp 1, 69-83.         [ Links ]

Pitla, S.S., Groll, E.A., Ramadhyani, S., (2002). New correlation to predict the heat transfer coefficient during in-tube cooling of turbulent supercritical CO₂. International Journal of Refrigeration 25, 887-895.         [ Links ]

Rieberer, R., (1999). CO₂ Properties. 11R Workshop on CO₂ Technology in Refrigeration. Heat Pump and Air Conditioning Systems, Mainz, Germany.         [ Links ]

Sánchez, D., Cabello, R., Llopis, R., Torrella, E., (2012). Development and validation of a finite element model for water - CO₂ coaxial gas-coolers. Applied Energy 93, 637-647.         [ Links ]

Sarkar, J., Agrawal, N., (2010). Performance optimization of transcritical CO₂ cycle with parallel compression economization. International Journal of Thermal Sciences 49, 838-843.         [ Links ]

Son, C.-H., Park, S.-J., (2006). An experimental study on heat transfer and pressure drop characteristics of carbon dioxide during gas cooling process in a horizontal tube. International Journal of Refrigeration 29, 539-546.         [ Links ]

Tanaka, K., Higashi, Y., (2010). Thermodynamic properties of HFO-1234yf (2, 3, 3, 3-tetrafluoropropene). International Journal of Refrigeration 33, 474-479.         [ Links ]

Woerdman, E., (2000). Implementing the Kyoto protocol: why JI and CDM show more promise than international emissions trading. Energy Policy 28, 29-38.         [ Links ]

Wojtkowiak, J., Popiel, C.O., (2000). Effect of cooling on pressure losses in u-type wavy pipe flow. International Communications in Heat and Mass Transfer 27, 169-177.         [ Links ]

Yoon-Yeong, B., Hwan-Yeol, K., (2009). Convective heat transfer to CO₂ at a supercritical pressure flowing vertically upward in tubes and an annular channel. Experimental Thermal and Fluid Science 33, 329-339.         [ Links ]

Yun, R., Hwang, Y., Radermacher, R., (2007). Convective gas cooling heat transfer and pressure drop characteristics of supercritical CO₂/oil mixture in a minichannel tube. International Journal of Heat and Mass Transfer 50, 4796-4804.         [ Links ]

Zhao, Y., Ohadi, M.O., (2004). Experimental Study of Supercritical CO₂ Gas Cooling in a Microchannel Gas Cooler, ASHRAE.         [ Links ]