TY - JOUR
T1 - Variable speed liquid chiller drop-in modeling for predicting energy performance of R1234yf as low-GWP refrigerant
AU - Mendoza-Miranda, J. M.
AU - Salazar-Hernández, C.
AU - Carrera-Cerritos, R.
AU - Ramírez-Minguela, J. J.
AU - Salazar-Hernández, M.
AU - Navarro-Esbrí, J.
AU - Mota-Babiloni, A.
N1 - Publisher Copyright:
© 2018 Elsevier Ltd and IIR
PY - 2018/9
Y1 - 2018/9
N2 - This paper presents a model for a variable-speed liquid chiller integrating a compressor model based on Buckingham π-theorem to accurately predict the system performance when R134a is replaced with R1234yf, using a wide range of data obtained from an experimental setup. Relevant variables such as temperature, pressure, mass and volumetric flow rates, compressor power consumption and rotation speed were measured at several positions along the refrigeration and secondary circuits and were used to validate the developed model. Model results show that cooling capacity and power consumption predicted values are in good agreement with experimental data, within ±5%, being slightly higher for the deviation obtained for R134a than for R1234yf. Moreover, model results indicate that R1234yf has a reduction of coefficient of performance (COP) compared with R134a (between 2 and 11.3%), and that R1234yf COP reduction is diminished at intermediate volumetric flow rate and higher inlet temperature for the evaporator secondary fluid, respectively. On the other hand, an environmental analysis based on TEWI (total equivalent warming impact) method showed that direct emissions are almost negligible for R1234yf. However, there are no environmental benefits in terms of indirect greenhouse gas emissions using R1234yf without system modifications (as for instance the addition of internal heat exchanger or R1234yf new design components), which are required to reduce the liquid chiller climate change contribution using it as low GWP alternative in comparison with the typically used R134a refrigerant.
AB - This paper presents a model for a variable-speed liquid chiller integrating a compressor model based on Buckingham π-theorem to accurately predict the system performance when R134a is replaced with R1234yf, using a wide range of data obtained from an experimental setup. Relevant variables such as temperature, pressure, mass and volumetric flow rates, compressor power consumption and rotation speed were measured at several positions along the refrigeration and secondary circuits and were used to validate the developed model. Model results show that cooling capacity and power consumption predicted values are in good agreement with experimental data, within ±5%, being slightly higher for the deviation obtained for R134a than for R1234yf. Moreover, model results indicate that R1234yf has a reduction of coefficient of performance (COP) compared with R134a (between 2 and 11.3%), and that R1234yf COP reduction is diminished at intermediate volumetric flow rate and higher inlet temperature for the evaporator secondary fluid, respectively. On the other hand, an environmental analysis based on TEWI (total equivalent warming impact) method showed that direct emissions are almost negligible for R1234yf. However, there are no environmental benefits in terms of indirect greenhouse gas emissions using R1234yf without system modifications (as for instance the addition of internal heat exchanger or R1234yf new design components), which are required to reduce the liquid chiller climate change contribution using it as low GWP alternative in comparison with the typically used R134a refrigerant.
KW - COP
KW - Hydrofuoroolefin (HFO)
KW - R134a
KW - TEWI
KW - Vapor compression system
KW - Variable speed compressor
UR - http://www.scopus.com/inward/record.url?scp=85051395908&partnerID=8YFLogxK
U2 - 10.1016/j.ijrefrig.2018.06.016
DO - 10.1016/j.ijrefrig.2018.06.016
M3 - Artículo
SN - 0140-7007
VL - 93
SP - 144
EP - 158
JO - International Journal of Refrigeration
JF - International Journal of Refrigeration
ER -