NOVELTY - A thermodynamic cycle device is formed by coupling a chemical regeneration cycle system and a low-temperature multi-effect distillation seawater desalting system. It includes an air compressor, a fuel compressor, fresh water pressure-increasing pumps, a reforming device, a fuel turbine powered through swelling of the high-temperature fuel, a generator connected with the fuel turbine, a waste heat boiler supplied with heat by the smoke, and a steam ejector using the margin pressure head of the dynamic steam for injecting and compressing the steam in the distillation device.    USE - A thermodynamic cycle device for realizing regeneration cycle and low-temperature multi-effect distillation seawater desalting, where methane and methyl alcohol are used as fuel (claimed).    ADVANTAGE - The regeneration cycle system and the low-temperature multi-effect distillation seawater desalting system can be complementary, thus the system can be integrally optimized. Different fuel, e.g. natural gas and methyl alcohol is changed in reforming temperature, thus the system structure demands to be adjusted to realize the excellent heat exchange matching. The efficiency is improved by 5-9% points. The saving ratio of the fossil energy can reach 11-19%. The device has excellent economical efficiency and a good prospect of engineering application.    DETAILED DESCRIPTION - A thermodynamic cycle device combined with a regeneration cycle system and a low-temperature multi-effect distillation seawater desalting system, comprises an air compressor for boosting air to a highest pressure in Brayton circulation. A fuel compressor is used for boosting fuel to the pressure in a reforming reaction. Two fresh water pressure-increasing pumps are used for boosting fresh water to the pressure in the reforming reaction and dynamic steam, respectively. A mixing chamber conveys compressed fuel and over-heat steam into a reforming device that is supplied with heat by smoke, so that fuel and steam can be reformed. A burning chamber is provided, in which synthesis gas and air are burnt to obtain high-temperature gas. A fuel turbine is powered through swelling of the high-temperature fuel. A heat regenerator heats the synthesis gas and partial compressed air and cools the fuel turbine to discharge gas. A generator connected with the fuel turbine can convert the mechanical power generated by the fuel turbine into electric energy, then output the electric energy. A waste heat boiler is supplied with heat by the smoke for heating the fresh water stream to generate power steam. A steam ejector uses the margin pressure head of the dynamic steam for injecting and compressing the steam in the distillation device. The steam is used as the heating steam to be conveyed to the first-effect distillation system to heat the seawater. An evaporator evaporates at low temperature under saturation pressure after the seawater is heated by steam.    DESCRIPTION OF DRAWING(S) - The drawing is a sectional view of a thermodynamic cycle device.