NOVELTY - Reducing energy consumption of urea device synthesis feeding system comprises synthesizing urea using carbon dioxide gas and liquid ammonia as raw materials. Under high pressure, the reaction of the carbon dioxide and liquid ammonia produces methyl amine. The methyl amine is dehydrated to obtain the urea.    USE - Method for reducing energy consumption of urea device synthesis feeding system.    ADVANTAGE - The method takes full use of the cooling energy of the low temperature liquid ammonia, heat energy of the natural environment and the waste heat of system to make the source be used properly; reduces the heating steam consumption by 22 kg/ton; and reduces the running parameter of the carbon dioxide compressor effectively. Under the same load, the compressor can reduce running at 60 revolutions/minute, and reduce steam consumption by 25 kg/ton.    DETAILED DESCRIPTION - Reducing energy consumption of urea device synthesis feeding system comprises synthesizing urea using carbon dioxide gas and liquid ammonia as raw materials, and under high pressure, the reaction of the carbon dioxide and liquid ammonia produces methyl amine. The methyl amine is dehydrated to obtain the urea. The carbon dioxide is cooled in the cooling device (2), condensed in the carbon dioxide compressor (3), and is sent to the urea synthesis reaction system. The liquid ammonia comes from the liquid ammonia storage of ammonia synthesis process system, and the liquid ammonia is firstly steam heated in the steam heater (4), then enters into the urea synthesis system, and a low temperature heat exchanger (1) is set in front of the carbon dioxide cooling device, the liquid ammonia exchanges the heat with the circulating water or the disposable water in the low temperature heat exchanger, then enters into the urea synthesis system. The circulating water or the disposable water in the low temperature heat exchanger after the heat exchanging is back to the circulating water system or enters into the cooling water inlet pipe of the carbon dioxide cooling device. The liquid ammonia inlet and outlet of the low temperature heat exchanger are connected with the liquid ammonia conveying pipe, which is in parallel with the steam heater in the liquid ammonia conveying pipe to form the liquid ammonia conveying ancillary line. The water inlet and outlet of low temperature heat exchanger are connected with the circulating water pipe and the cooling water inlet pipe of the carbon dioxide cooling device. The low temperature heat exchanger replaces steam heater as the main device to increase the temperature of the liquid ammonia.    DESCRIPTION OF DRAWING(S) - The drawing is a schematic diagram of the method for reducing energy consumption of urea device synthesis feeding system.    Low temperature heat exchanger (1)    Cooling device (2)    Carbon dioxide compressor (3)    Steam heater (4)    Low temperature heat exchanger baffle plate (5)