Modified duct heater heat dispersion system

The invention relates to a heat-radiating system which comprises an evaporator and a condensing device. The condensing device comprises a steam passage, a condensing zone, and a condensate passage arranged around the steam passage. One end of the steam passage is connected with the evaporator to transfer steams from the evaporator. The condensing zone is connected with the other end of the steam passage to condense the steams to produce a condensate. The condensate passage is arranged around the steam passage and connected with the condensing zone and the evaporator. The condensate flows through the condensate passage and returns to the evaporator wherein the condensate is converted into steams under the action of an external heat source, so as to realize the circulation of gas and liquid phases and ensure good heat-radiating or heat-transfer effect. The inventive heat-radiating system is practical and feasible and can increase heat-radiating efficiency and space utilization rate.