The invention discloses a multi-mode combined
power cycle system based on transcritical CO2 and a method, and belongs to the field of
aviation power propulsion. According to the multi-mode combined
power cycle system based on transcritical CO2 and the method, a
turbine engine, a
ramjet and the supercritical CO2
Brayton cycle are coupled, so that a hypersonic aircraft can be switched in
multiple modes, and therefore the purpose of wider-range work is achieved. The
system comprises an air
inlet channel (1), an inner duct (2), an outer duct (3), a precooler (4), a compressor (5), a main
combustion chamber (6), an air
turbine (7), an
afterburner (8), a spray
pipe (9), a CO2
turbine (12), a condenser (13), a pump (14), a liquid CO2 tank (10), a
liquid oxygen tank (15), a first switch (11) and a second switch (16). According to the combined
power cycle, transcritical CO2 closed
heat energy gradient
recovery Brayton cycle is adopted in a super-precooling flight mode, and
liquid oxygen is utilized for condensation, so that the energy utilization of the system is maximized; and in addition, supercritical CO2 is adopted as a pre-cooling working medium to replace traditional
helium, the
system structure is more compact, the thrust is larger, and the wider-range working requirement can be rapidly met.