Abstract: A vapour compression device including an internal heat exchanger, a low-pressure compressor and an associated gas cooler, a fluid distributor separating the fluid into a main circuit of the cycle and into an auxiliary cooling circuit of the cycle, an auxiliary expansion system placed on the auxiliary cooling circuit, and a main expansion system placed on the main circuit of the cycle. The device also includes a high-pressure compressor and an associated gas cooler placed on the main circuit of the cycle. A method for performing a transcritical fluid cycle including a substantially isentropic compression step of the fluid, on the main circuit of the cycle, to reach a maximum high pressure greater than a critical pressure of the fluid, and an isobaric cooling step of the fluid to substantially reach a cold source temperature.

Abstract: The vapour compression device according to the invention comprises an internal heat exchanger, a low-pressure compressor and an associated gas cooler, a fluid distributor separating the fluid into a main circuit of the cycle and into an auxiliary cooling circuit of the cycle, an auxiliary expansion system placed on the auxiliary cooling circuit, and a main expansion system placed on the main circuit of the cycle. The device also comprises a high-pressure compressor and an associated gas cooler placed on the main circuit of the cycle. The method for performing a transcritical fluid cycle according to the invention preferably comprises an isentropic compression step of the fluid, on the main circuit of the cycle, to reach a maximum high pressure greater than a critical pressure of the fluid, and an isobaric cooling step of the fluid to substantially reach a cold source temperature.