Systems and apparatuses include a diesel exhaust fluid tank, a first temperature sensor positioned within the diesel exhaust fluid tank and structured to provide first temperature information indicative of a first temperature, and a second temperature sensor positioned within the diesel exhaust fluid tank and structured to provide second temperature information indicative of a second temperature. The systems and apparatuses further include one or more processing circuits including one or more memory devices coupled to one or more processors, the one or more memory devices configured to store instructions thereon that, when executed by the one or more processors, cause the one or more processors to provide energy to a heating system based on the first temperature information and the second temperature information.

A urea water solution injection system includes a urea water solution injection device for spraying a urea water solution into a portion of an exhaust passageway upstream of a selective catalytic reduction catalyst device, to reduce NOx in exhaust gas discharged from an internal combustion engine. Engine coolant is circulated through the urea water solution injection device to prevent freezing of the urea water solution. A crystal dissolution control unit performs crystal dissolution control on the urea water solution injection device by energizing at a preset amount of energization at a state where a urea water solution supply pump for supplying a urea water solution to the urea water solution injection device is kept stopped, and the crystal dissolution control unit performs the crystal dissolution control for a crystal dissolving energization time calculated in advance, after the engine is started but before a urea water solution is supplied.

A method of controlling a vehicle includes determining if a diesel emission fluid is at least partially frozen, and determining if the vehicle is currently operating in a low diesel emission fluid inducement protocol. If the vehicle is not currently operating in the low diesel emission fluid inducement protocol, and the diesel emission fluid is at least partially frozen, then a temporary minimum diesel emission fluid mass may be defined to prevent entry of the vehicle into the low diesel emission fluid inducement protocol.

A system and method for managing the temperature of a urea solution are thereby provided, in which air bubble formation in the urea solution caused by increases in the urea solution temperature is suppressed while thawing of the urea solution stored in the urea solution tank and used for NOx purification treatment is ensured, the concentration of the urea contained in the urea solution is accurately determined, and NOx is precisely reduced.

In an exhaust gas purification apparatus for an internal combustion engine which is provided with an NOx catalyst arranged in an exhaust passage of the internal combustion engine, the present invention has for its problem to be solved to suppress an increase in exhaust emissions, which results from processing for raising the temperature of the NOx catalyst, to a small level. In order to solve the above-mentioned problem, the exhaust gas purification apparatus for an internal combustion engine of the invention is constructed such that when an amount of increase in the NO.sub.X removal rate becomes smaller with respect to an amount of rise in the temperature of the NOx catalyst, the execution of temperature raising processing is deferred, and processing to make small the flow rate of exhaust gas discharged from the internal combustion engine and processing to make small the amount of smoke discharged from the internal combustion engine are executed.

A reducing agent injection device includes a honeycomb structure having a honeycomb structure body and a pair of electrode members arranged in a side surface of the honeycomb structure body and a urea spraying device spraying a urea water solution in mist form. The urea water solution sprayed from the urea spraying device is supplied inside cells from a first end face of the honeycomb structure body, and urea in the urea water solution supplied in the cells is heated and hydrolyzed inside the electrically heated honeycomb structure body to generate ammonia. The ammonia is discharged outside the honeycomb structure body from a second end face and injected outside. There is provided a reducing agent injection device that can generate and inject ammonia from a urea solution with less energy.

An exhaust gas purification apparatus includes: a reduction catalyst converter that reduces and purifies nitrogen oxides in exhaust gas; a tank that stores a liquid reducing agent or precursor thereof; and an injection nozzle that injects the liquid reducing agent or precursor thereof stored in the tank on an exhaust gas upstream side of the reduction catalyst converter. Some of the exhaust gas flowing through an exhaust pipe is diverted to the tank by a bypass pipe, to cause an exchange of heat between the diverted exhaust gas and the liquid reducing agent or precursor thereof stored in the tank, thereby thawing the liquid reducing agent or precursor thereof frozen in the tank.

A work vehicle includes a vehicle body, a guiding pipe, a first heating section, and a second heating section. The vehicle body has a partition wall that partitions a space in an inner section into a first region and a second region. The guiding pipe is configured to guide a reducing agent. The guiding pipe has a first pipe section and a second pipe section. The first pipe section is positioned inside the first region. The second pipe section is positioned in the second region. The first heating section heats the first pipe section. The second heating section heats the second pipe section and adjusts the temperature independently from the first heating section.

The control method for reducing agent supply apparatuses, when a liquid reducing agent is frozen, unfreezes the frozen liquid reducing agent using a heating device and enables the injection control of the liquid reducing agent in an exhaust passage of the internal combustion engine. The control method includes determining the necessity of unfreezing of the liquid reducing agent and calculating the necessary time required for the unfreezing when the speed of the internal combustion engine exceeds a predetermined threshold during startup of the internal combustion engine and permitting the injection control of the liquid reducing agent when the unfreezing is not necessary or the unfreezing is completed.

A vehicle includes a power converter that receives power, and has first and second outputs, a low voltage battery that receives power from the power converter via the first output, and a heating element that receives power from the power converter via the second output, and provides heat to a catalyst of an exhaust system. The vehicle also includes a controller that commands the converter to provide power to the heating element via the second output according to a temperature of the catalyst.