Mechanical pump type SCR urea spraying system

The invention relates to a mechanical pump type SCR urea spraying system, consisting of a urea tank, a urea tank switch valve, a filter, a urea pump, an energy accumulator, a urea nozzle, a heat exchanger, a pressure regulating valve, a cooling device, and an electronic control unit. The system is characterized in that the urea pump is a mechanical pump, and the driving wheel of a diesel engine drives the transmission shaft of the urea pump through a pulley. A urea cooling device consists of the cooling device, a temperature control valve, a refrigerant inlet pipe and a refrigerant outlet pipe. The urea cooling device is arranged between the pressure regulating valve and the switch valve of the main pipeline. The energy accumulator is arranged on the pipeline between the outlet of the urea nozzle and the pressure regulating valve. The refrigerant inlet pipe of the urea cooling device is connected with the high pressure pipe of the automotive air conditioning, the refrigerant outlet pipe is connected with the low pressure pipe of the air conditioning, and the flow direction of the refrigerant fluid is opposite to the flow direction of the urea solution. The system of the invention reduces the energy consumption, and the flow rate of the urea solution is regulated in real time according to the engine speed, thereby avoiding the waste of the energy. The mechanical pump also has the advantages of low cost, long service life and is convenient to maintain.