A Simulation Research on NH3/CO2 Cascade Refrigeration System Based on Theoretical Model

Abstract

The rapid development of the refrigeration industry has benefited production and life, and has also brought irreversible negative impacts on the current environment. Finding environment friendly, energy-saving, stable, and new-type alternative refrigerants has become a common concern and research hot spot of researchers and the refrigeration industry around the world. In this article, a NH₃/CO₂ cascade refrigeration system model is established. CO₂ is used as the refrigerant in the low temperature cycle, NH₃ is used as the refrigerant in the high temperature cycle, and the condensing evaporator is used to couple the heat exchange between the high and low temperature circuits. Based on the first law of thermodynamics and the second law of thermodynamics, the author carries out the energy analysis and exergy analysis of the cascade system. Applying MATLAB software to establish the simulation calculation of NH₃/CO₂ cascade cycle. Through simulation, the author explores the effects of low temperature cycle CO₂ evaporation temperature and high temperature cycle NH₃ condensation temperature cycle parameters on the system cycle performance and system exergy efficiency. This paper provides a certain theoretical basis for improving the design of system structure and the system performance coefficient through simulation calculation.