Urea heating system and heating method thereof

The present invention relates to a urea water heating apparatus and a method capable of preventing the freezing of the urea water with the exhaust gas of the engine. More specifically, the number to bypass a portion of exhaust gas components to perform a heat exchange between the exhaust gas and the number of elements by using the pressure difference between the exhaust gas pipe and muffler relates to a heating apparatus and method. Exhaust gas pipe urea heating apparatus according to an embodiment of the present invention, the exhaust gas of high temperature and high pressure discharged after combustion engine; Is connected to one end of the exhaust gas pipe, it is possible to reduce the pressure and temperature of the exhaust gas muffler for emission to the atmosphere; A first bypass pipe diverged from the exhaust gas pipe being a part of the exhaust bypass; The first being the exhaust gas is fed bypassing the first bypass pipe, the urea water tank, the number of elements stored therein; A second bypass pipe that supplies the exhaust gas that has passed through one end is connected to the urea water tank to the muffler to the silencer; And heat exchange tubes inside the tank element which is provided to the first bypass pipe and the second connection of the bypass pipe, and performing heat exchange of urea and exhaust gas; A part of the exhaust gas by a pressure difference of the exhaust gas pipe and the muffler can be bypassed, including but. The number of elements in accordance with an embodiment of the present invention, the heating method, the engine combustion exhaust gas after the exhaust gas pipe, the muffler connected to the exhaust gas pipe is discharged, the number of elements for storing the urea tank, and branched from the exhaust gas pipe can be the element determined according to the number of elements comprising a solenoid valve by way of the tank to selectively open and close the by-bass tube and the bypass pipe connected to the silencer a heating apparatus, the current rotational speed of the engine faster than idle rotational speed of the engine step (S100) to; Determining that the water temperature of the element is lower than the set temperature by a temperature sensor provided inside of the tank element (S110); The method comprising the current rotational speed of the engine is determined smaller than the maximum rotational speed of the engine (S120); Determining that the load of the engine is less than the allowable value (S130); After the S100, S110, S120 and S130 of the determination step are both satisfied, the step (S150) for opening said solenoid valve; If the S100, S110, S120 and S130 of one of the determining step is not satisfied even if the step (S160) of closing the solenoid valve; And a step (S170) to S150 or if the step S160 is performed, the process from the step S100 again; It may contain.