| 摘要 |
<p>A reductant delivery system for a SCR system in an internal combustion engine comprises a reductant tank (52) and a dosing valve (54) connected via a feed line (53). A coolant loop (60) using hot engine coolant comprises: flow restrictor means (68) dividing the coolant loop (60) in an upstream, first section (62a) on the inlet side, and a downstream, second section (62b); a tank loop (64) connected to the coolant loop (60) upstream and downstream of the flow restrictor means (68) and passing through the reductant tank (52) for thawing frozen reductant solution; a doser section (66), downstream of the tank loop (64), to carry engine coolant of the second section (62b) and arranged in thermal exchange relationship with said dosing valve (54) for cooling thereof; and valve means (70; 72; 76; 80) operable to allow or stop the flow of engine coolant through said tank loop (64).</p> |
