Abstract Supercritical CO2 (sCO2) power cycles have gained prominence for their expected excellent performance and compactness. Among benefits, they may potentially reduce the cost of Concentrated Solar Power (CSP) plants. Because critical temperature is close to ambient temperatures in areas with good solar irradiation, dry cooling penalise efficiency sCO2 CSP Recent research has investigated ...

We investigate dynamical system having a special structure namely a codimension-one invariant manifold that is preserved under the variation of parameters. We derive conditions such that bifurcations of codimension-one and of codimension-two occur in the system. The normal forms of these bifurcations are derived explicitly. Both local and global bifurcations are analysed and yield the transcrit...

This paper presents the experimental as well as the simulated performance studies on the transcritical CO2 heat pumps for simultaneous water cooling and heating; effects of water mass flow rates and water inlet temperatures of both evaporator and gas cooler on the cooling and heating capacities, system COP and water outlets temperatures are investigated. Study shows that both the water mass flo...

A transcritical heat pump (THP) cycle using carbon dioxide (CO2) as the refrigerant is known to feature an excellent coefficient of performance (COP) as a thermodynamic system. Using this feature, we are designing and building a system that combines a water-to-water CO2 heat pump with both hot and cold thermal storages know as Thermal Battery (TB) (Blarke, 2012). Smart and effective use of inte...

To investigate the performance of transcritical CO2 quasi-secondary compression cycle with ejector (TCIEJ) for heat pump water heaters, thermodynamic model TCIEJ is established based on pinch point, and TCEX, TCEJ, TCI are selected as comparisons. The effects changing high pressure ambient temperature heating COP compressor exhaust analyzed, influence cooling inlet outlet vapor injection furthe...

Energetic and exergetic analyses as well as optimization studies of a transcritical carbon dioxide heat pump system are presented in this article. A computer code has been developed to obtain sub-critical and super-critical thermodynamic and transport properties of carbon dioxide. Estimates for irreversibilities of individual components of the system lead to possible measures for performance im...

Theoretical and experimental studies are carried out on a transcritical CO2 based air-conditioning unit. Two configurations– system with single-stage expansion (SSE) two-stage (TSE) have been considered. Detailed numerical models developed for both configurations. Results obtained from simulations compared results. The performance of the is under different conditions refrigerant charge, receive...