The invention relates to an arrangement and a method for converting
waste heat into
mechanical energy using supercritical sCO2, comprising a pump arrangement (1) for increasing the pressure of the CO2 through a line (2), two heat exchangers, a pre-heating device (7) and a main heating device (12), for transferring
waste heat from a
waste heat stream in a line (14, 15, 16) to the CO2 as working medium, such that the CO2 can be present in the supercritical state, an engine (17) for generating
mechanical energy by means of the sCO2, and an absorption cooling
system for controlled cooling of the CO2 from the engine (17), comprising an expeller (23) and an
evaporator (31), wherein a line for the CO2 (19) exiting the engine (17) goes from the engine (17) to the expeller (23) and to the
evaporator (31) of the absorption cooling
system. According to the invention, the absorption cooling
system keeps the temperature at the inlet of the pump arrangement (1) constantly below the critical temperature, a
recuperator (6) is arranged between the engine (17) and expeller (23) for the transfer of heat from the CO2 exiting the engine (17) to the sCO2 going to the engine (17), and a
flow divider (3) is arranged between the pump arrangement (1), the
recuperator (6) and the pre-heating device (7) to divide the
stream of CO2 into a first partial
stream to the
recuperator (6) and a second partial stream for the transfer of waste heat by means of the two heat exchangers (7, 12).