TY - JOUR

T1 - Compressor power modeling

T2 - Part 1 thermodynamic efficiency determination from manufacturer's performance curves

AU - Kulkarni, Manohar R.

PY - 2001/12/1

Y1 - 2001/12/1

N2 - Compressor is at the heart of any refrigeration system and it is also the largest consumer of energy. Thus for an energy efficient operation of a refrigeration system it is imperative that compressor performance be understood and closely monitored. Further, as the current trend of the integrated electromechanical control becomes a common place there will be opportunities to utilize a switchover control strategy (or strategies), especially for the off-design or part-load system operations. Hence a compressor power model approach based on the manufacturer's data is proposed. Compressor performance curves are usually provided by the manufacturers. These curves give full load compressor power and the cooling capacity as a function of saturation evaporator and condenser temperatures for a specified amount of subcooling and for either a specified amount of superheat or for a specified compressor return temperature. The proposed modeling approach will work equally well with either compressor performance curves; however the efficiency determination procedure will be slightly different in each case. From the performance curves the rated compressor power and rated capacity are determined at specific saturation evaporator and condenser temperature. These values, the compressor specifications and the other thermodynamic property information are utilized to compute the volumetric and isentropic efficiencies. It is then assumed that these efficiencies remain invariant with respect to the amount of superheat and the amount of subcooling. Next, using a linear multi-variate regression analysis, curve-fits for the efficiencies as a function of saturation and condenser temperatures are developed.

AB - Compressor is at the heart of any refrigeration system and it is also the largest consumer of energy. Thus for an energy efficient operation of a refrigeration system it is imperative that compressor performance be understood and closely monitored. Further, as the current trend of the integrated electromechanical control becomes a common place there will be opportunities to utilize a switchover control strategy (or strategies), especially for the off-design or part-load system operations. Hence a compressor power model approach based on the manufacturer's data is proposed. Compressor performance curves are usually provided by the manufacturers. These curves give full load compressor power and the cooling capacity as a function of saturation evaporator and condenser temperatures for a specified amount of subcooling and for either a specified amount of superheat or for a specified compressor return temperature. The proposed modeling approach will work equally well with either compressor performance curves; however the efficiency determination procedure will be slightly different in each case. From the performance curves the rated compressor power and rated capacity are determined at specific saturation evaporator and condenser temperature. These values, the compressor specifications and the other thermodynamic property information are utilized to compute the volumetric and isentropic efficiencies. It is then assumed that these efficiencies remain invariant with respect to the amount of superheat and the amount of subcooling. Next, using a linear multi-variate regression analysis, curve-fits for the efficiencies as a function of saturation and condenser temperatures are developed.

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M3 - Article

AN - SCOPUS:0346151429

VL - 2

SP - 721

EP - 726

JO - Proceedings of the Intersociety Energy Conversion Engineering Conference

JF - Proceedings of the Intersociety Energy Conversion Engineering Conference

SN - 0146-955X

ER -