| 摘要 |
Disclosed is an SCR thawing control system that can distinguish between thawing failures and malfunctions and can prevent SM pump malfunctions. If an aqueous urea solution freezes in a urea tank (105) that stores said aqueous urea solution, within feed/pumping/collection lines (116, 117, and 118) between the urea tank (105) and a dosing valve (104) that sprays the aqueous urea solution upstream of an SCR device (103), or in a supply module (106) connected to the feed/pumping/collection lines (116, 117, and 118), the disclosed SCR thawing control system (127) thaws the aqueous urea solution using engine cooling water and then runs an SM pump (112) in the supply module (106) to spray the thawed aqueous urea solution from the dosing valve (104). Said SCR thawing control system (127) is provided with a thawing control unit (128) that detects the pressure inside the supply module (106) when the SM pump (112) is run, and if said pressure is less than a given value, the thawing control unit (128) stops the SM pump (112) and resumes the process of thawing the aqueous urea solution. |
