CO2 Heat Pumps in the Drying Industry: Identifying the Break-Even Point Between Transcritical and Supercritical Operation

Abstract

In the drying industry, energy-efficient heat recovery systems are essential for optimizing thermal processes and reducing operational costs. High-temperature heat pumps, particularly CO2-based systems, offer promising potential due to their favourable thermodynamic properties and environmental benefits. Drying processes typically operate at temperatures ranging from 60°C to 220°C, with hot air commonly used as the medium for heat transfer. Transcritical and supercritical CO2 heat pumps each have unique advantages depending on the temperature and pressure conditions of the process. This research investigates the performance characteristics of trans-critical and supercritical CO2 heat pumps in industrial drying applications, while identifying the break-even point between these two configurations, focusing on key parameters such as system efficiency and operational conditions. Thermodynamic modelling and performance simulations are employed to assess how variations in source temperature, system design, and operating conditions affect the choice between transcritical and Supercritical operation. Understanding this break-even point is crucial for optimizing CO2 heat pump systems for drying processes, ensuring that the system operates at peak efficiency while meeting the thermal demands of industrial drying. By examining these configurations in-depth, the study aims to contribute valuable insights into the potential for CO2 heat pumps to enhance energy efficiency, reduce environmental impact, and support more sustainable practices in the drying industry.