Selective catalytic reduction (SCR) urea heating/cooling system and method

Abstract

The invention relates to the field of tail gas treatment of engineering machinery, in particular to a selective catalytic reduction (SCR) urea heating / cooling system and method. The system comprises an engine and a radiator and further comprises a heating and cooling pipe disposed in a urea tank. The heating and cooling pipe is provided with a first water inlet port and a first water outlet port. The engine is provided with a second water inlet port and a second water outlet port. The radiator is provided with a third water inlet port and a third water outlet port. In addition, the second water outlet port is connected with the third water inlet port in a communicating mode, and the third water outlet port is connected with the second water inlet port in a communicating mode, so that heat dissipation is performed on the engine. The first water inlet port is connected with the second water outlet port and the third water inlet port in a communicating mode, and the first water outlet port is connected with the second water inlet port, so that urea is heated through hot water discharged from the engine and the urea is cooled through warm water discharged from the radiator. By means of the scheme, control can be performed according to the real-time temperature of the urea, so that the urea works at the appropriate temperature all the time, and the emission performance of a machine is guaranteed.

Description

technical field [0001] The invention relates to the field of exhaust gas treatment of engineering machinery vehicles, in particular to an SCR urea heating / cooling system and method. Background technique [0002] In the current construction machinery, with the upgrading of emissions, especially the installation of diesel engines in excavators. At present, ier4f engines that meet Euro IV emissions have been implemented in European and American markets. In order to meet the requirements of emission regulations, most engines use SCR systems, that is, selective catalytic reduction systems to reduce engine emissions. Urea is an odorless and non-toxic solution that is stored in specially configured urea tanks on diesel vehicles. When the exhaust gas is removed from the engine, it travels with the exhaust gas to the truck's catalytic converter, where the ammonia produced by pyrolysis converts nitrogen oxides into harmless nitrogen and water, greatly reducing exhaust emissions. Ure...

AI Technical Summary

Problems solved by technology

The urea solution is alkaline and highly corrosive to copper, cast iron, solder, and cast aluminum. It should not be lower than -11°C, because lower than -11°C will easily cause the urea solution to freeze, resulting in blockage of the urea pipe and urea tank, making the urea pump and urea nozzle unable to work, and affecting the exhaust function of the machine

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