Research on the Performance of Carbon Dioxide Heat Pump for Gravure Printing Machine Drying System

This study addresses the issues of low energy efficiency and high energy consumption in traditional gravure printing machine drying systems by proposing an optimization approach using transcritical CO<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> heat pump technology. Through the establishment of a mathematical model for the CO<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> transcritical heat pump system, the influence of key parameters such as inlet air temperature and airflow rate in evaporators and gas coolers on the system's Coefficient of Performance (COP) and outlet air temperature was systematically analyzed. The results demonstrate that when the evaporator inlet air temperature increases from 20°C to 40°C, the system COP improves from 3.489 to 4.096. Similarly, increasing the evaporator airflow rate from 2000 mvh to 4000 m<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup>/h elevates the COP to 4.096. Conversely, raising the gas cooler inlet air temperature from 31°C to 50°C causes a significant COP decline from 4.096 to 1.808. Furthermore, enhancing the gas cooler airflow rate effectively improves COP. These findings indicate that optimizing inlet air parameters can substantially enhance system energy efficiency. The research provides theoretical foundations for energy-efficient design of gravure printing machine drying systems and promotes industrial applications of transcritical CO<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> heat pump technology.