Abstract
As an environmentally friendly low global warming potential (GWP) refrigerant, Carbon dioxide (CO2) has continuously gained popularity and research attention as alternative refrigerant for supermarket refrigeration system. In this paper, to fulfill the increasing need of accurate Low-GWP supermarket refrigeration models for development of supervisory level control and optimization strategies, a high fidelity model is developed for CO2 transcritical supermarket refrigeration system which includes compressor rack of low temperature (LT) compressors and medium temperature (MT) compressors, air-cooled gas cooler, evaporator, expansion valves and other auxiliary equipment. A resistance-capacity model structure is proposed to simulate the display cases. Semi-thermodynamic models are proposed to estimate reciprocating compressors volumetric efficiency and power consumption. The zone modeling approach is used for evaporator simulation, and air-cooled gas cooler is modeled with distributed modeling method. The expansion valve simulation is based on orifice flow model. To calibrate these models, both manufacture performance data and experimental data are used. The experiments are conducted with a full instrumental CO2 supermarket refrigeration system installed in Oak Ridge National Lab Flexible Research Platform (FRP). The simulation model can predict the system performance, including power consumption, cooling capacity, mass flow rate, temperature, and pressure, with high accuracy (within ±4%) compared to experimental data. In addition, this developed model has been used to create the system optimum high side pressure for high side expansion valve control, and to generate wide operating range simulation data for developing the batter-equivalent commercial refrigeration system model which can be used in grid interactive control development.
| Original language | English |
|---|---|
| Pages (from-to) | 195-209 |
| Number of pages | 15 |
| Journal | International Journal of Refrigeration |
| Volume | 126 |
| DOIs | |
| State | Published - Jun 2021 |
Funding
This manuscript has been authored in part by UT-Battelle, LLC, under contract DE-AC05-00OR22725 with the US Department of Energy (DOE). The US government retains and the publisher, by accepting the article for publication, acknowledges that the US government retains a nonexclusive, paid-up, irrevocable, worldwide license to publish or reproduce the published form of this manuscript, or allow others to do so, for US government purposes. DOE will provide public access to these results of federally sponsored research in accordance with the DOE Public Access Plan ( http://energy.gov/downloads/doe-public-access-plan ). This material is based upon work supported by the U.S. Department of Energy (DOE), Grid Modernization Laboratory Consortium (GMLC), DOE Office of Electricity and Office of Energy Efficiency and Renewable Energy Funding for this research was provided by the US Department of Energy (DOE), Grid Modernization Laboratory Consortium (GMLC), DOE Office of Electricity, Office of Energy Efficiency and Renewable Energy, Vehicle Technologies Program. The authors would like to thank Lee Slezak, Vehicle Systems and Testing Manager in the Vehicle Technologies Program, for his support of this work, and thank Dr. Brain Flake, Mr. Vishaldeep Sharma from Oak Ridge National Lab for providing part of testing data. This manuscript has been authored in part by UT-Battelle, LLC, under contract DE-AC05-00OR22725 with the US Department of Energy (DOE). The US government retains and the publisher, by accepting the article for publication, acknowledges that the US government retains a nonexclusive, paid-up, irrevocable, worldwide license to publish or reproduce the published form of this manuscript, or allow others to do so, for US government purposes. DOE will provide public access to these results of federally sponsored research in accordance with the DOE Public Access Plan (http://energy.gov/downloads/doe-public-access-plan). This material is based upon work supported by the U.S. Department of Energy (DOE), Grid Modernization Laboratory Consortium (GMLC), DOE Office of Electricity and Office of Energy Efficiency and Renewable Energy
| Funders | Funder number |
|---|---|
| DOE Public Access Plan | |
| Grid Modernization Laboratory Consortium | |
| Lee Slezak | DE-AC05-00OR22725 |
| U.S. Department of Energy | |
| Office of Energy Efficiency and Renewable Energy | |
| Office of Electricity |
Keywords
- Carbon dioxide (CO)
- GWP (global warming potential)
- Optimum high-side pressure
- Supermarket refrigeration
