Development of a virtual variable-speed compressor power sensor for variable refrigerant flow air conditioning system

This paper proposed a universal virtual variable-speed compressor power (VVCP) sensor for VRF system based on 20-coefficient model. Compressor power can be obtained by the VVCP sensor using three input parameters (frequency, condensing temperature and evaporation temperature) which are measured by system itself. The performance of the proposed VVCP sensor is evaluated using experiments data. Experimental conditions include cooling, heating and non-standard refrigerant charge levels. The result shows that the mean square percentage errors (MSPE) are 9.9% under cooling conditions and 7.96% under heating conditions. The MSPE are 9.88% at steady state and 9.75% at dynamic state when the VVCP sensor is applied under nine different refrigerant charge levels. It demonstrated that the proposed VVCP sensor can obtain compressor power under cooling, heating and non-standard refrigerant charge levels, which could be applied to do operational monitoring and fault detection and diagnosis for VRF system at low cost.

[1]  Eric Dumont,et al.  Modeling of scroll compressors – Improvements , 2010 .

[2]  James E. Braun,et al.  Virtual Refrigerant Pressure Sensors for Use in Monitoring and Fault Diagnosis of Vapor-Compression Equipment , 2009 .

[3]  James E. Braun,et al.  Decoupling features and virtual sensors for diagnosis of faults in vapor compression air conditioners , 2007 .

[4]  Spilios D. Fassois,et al.  Aircraft Virtual Sensor Design Via a Time-Dependent Functional Pooling NARX Methodology , 2013 .

[5]  Woohyun Kim,et al.  Virtual Refrigerant Mass Flow and Power Sensors for Variable-Speed Compressors , 2012 .

[6]  Savvas A. Tassou,et al.  Mathematical modelling of supermarket refrigeration systems for design, energy prediction and control , 2000 .

[7]  Seo Young Kim,et al.  Indoor unit fault detector for a multi-split VRF system in heating mode , 2014 .

[8]  Reinhard Radermacher,et al.  Experimental investigation of multifunctional VRF system in heating and shoulder seasons , 2014 .

[9]  James E. Braun,et al.  Mathematical modeling of scroll compressors — part II: overall scroll compressor modeling , 2002 .

[10]  Shuangquan Shao,et al.  Performance representation of variable-speed compressor for inverter air conditioners based on experimental data , 2004 .

[11]  Reinhard Radermacher,et al.  Field performance measurements of a VRF system with sub-cooler in educational offices for the cooling season , 2012 .

[12]  Mo Yang,et al.  A virtual condenser fouling sensor for chillers , 2012 .

[13]  James E. Braun,et al.  A review of virtual sensing technology and application in building systems , 2011, HVAC&R Research.

[14]  James E. Braun,et al.  Development, Evaluation, and Demonstration of a Virtual Refrigerant Charge Sensor , 2009 .

[15]  Arne Jakobsen,et al.  REVIEW OF COMPRESSOR MODELS AND PERFORMANCE CHARACTERIZING VARIABLES , 2000 .

[16]  M. Zaheer-uddin,et al.  Dynamic simulation of energy management control functions for HVAC systems in buildings , 2006 .

[17]  Ali Charara,et al.  Virtual sensors, application to vehicle tire-road normal forces for road safety , 2009, 2009 American Control Conference.

[18]  Ashok N. Srivastava,et al.  Improvements in virtual sensors: using spatial information to estimate remote sensing spectra , 2005, Proceedings. 2005 IEEE International Geoscience and Remote Sensing Symposium, 2005. IGARSS '05..

[19]  Mingsheng Liu,et al.  Development of a variable speed compressor power model for single-stage packaged DX rooftop units , 2015 .

[20]  James E. Braun,et al.  Virtual Power Consumption and Cooling Capacity Virtual Sensors for Rooftop Units , 2014 .