Volume 39: Energy Transitions toward Carbon Neutrality: Part II

Experimental Investigation of CO2/R32 Mixture Combined Cooling and Power Cycle under Variable Heat Source Conditions Yu Yao, Xiaocun Sun, Jintao He, Bowen Lu, Lingfeng Shi, Gequn Shu

Abstract

CO2 owing to its excellent heat transfer properties and environmental sustainability, has been extensively explored for integration into future energy systems. CO2-based combined cooling and power cycles exhibit great potential for diverse multi-energy complementarity scenarios, offering high source-sink matching and adjustability. However, they face challenges related to stringent condensation requirements and suboptimal energy conversion. In response, CO2/R32 mixture systems have emerged as a promising solution to enhance efficiency and condensation performance. This paper presents preliminary experimental research results on the CO2/R32 mixture combined cooling and power cycle. It showcases the performance of CO2/R32 system under varying heat source conditions and its impact on power and cooling sub-cycles. CO2/R32 demonstrates excellent thermal matching performance and outstanding potential for utilizing medium and low-temperature thermal energy. The CCPC system can simultaneously produce 536W of predicted net power and 1550W of cooling capacity with an energy efficiency of 13.91% and a COP of 4.71. Additionally, the reduction in critical pressure and the increase in critical temperature have effectively improved the operating pressure and condensing conditions of the system. Under the same condensing conditions, the condensing pressure has decreased from 6.7MPa to 3.0MPa, and the operable condensing temperature range has significantly expanded.

Keywords clean energy conversion technology, CO2-based mixture, cogeneration and polygeneration, combined cooling and power cycle, experimental investigation