A urea water agitation control device has an agitation control portion and a temperature sensor which detects a temperature of a urea water. The agitation control portion operates an agitation portion in a specified period which includes a part of a period in which the urea water temperature detected by the temperature sensor is kept at a eutectic point and the urea water radiates a latent heat of solidification.

Methods and systems are provided for a single heat exchanger coupled to a main exhaust passage upstream of one or more exhaust catalysts or in between two exhaust catalysts for exhaust heat recovery and exhaust gas recirculation (EGR) cooling. In one example, in the pre-catalyst configuration of the heat exchanger, during exhaust heat recovery, a portion of exhaust may be routed via the heat exchanger while the remaining portion of exhaust may be routed directly to the exhaust catalysts, and fueling may be adjusted on a per-cylinder basis to maintain a target exhaust air-fuel-ratio at the exhaust catalysts.

Methods and systems are provided for exhaust gas heat recovery using a bottoming cycle comprising an exhaust heat exchanger. In one example, a method may include maintaining a target thermal energy input to the heat exchanger by opportunistically flowing exhaust through the heat exchanger after storing a portion of thermal energy from the exhaust in a thermal storage device or prior to flowing exhaust through the heat exchanger, heating the exhaust by drawing thermal energy from the thermal storage device.

A chemical heat storage device includes a reactor which has a heat storage material which generates heat by a chemical reaction with a reactive medium and desorbs the reactive medium by heat absorption, and a receptacle which houses the heat storage material therein; a reservoir which stores the reactive medium; a connecting pipe through which the reactor and the reservoir communicate with each other and the reactive medium is allowed to flow between the reactor and the reservoir, wherein the reactive medium is ammonia, the receptacle is made of a metallic material (for example, stainless steel), and at least a portion of an inner surface of the receptacle which comes into contact with the ammonia is formed with a nickel layer containing 90% nickel by mass or more.

A chemical heat storage device includes a reaction vessel accommodating a heat storage material, a heat exchange flow path provided so that a heat-exchange fluid flows along an outer surface of the reaction vessel, and the chemical heat storage device being configured in such a manner that the reaction vessel is rotated and the heat storage material is agitated, by a flow force of the heat-exchange fluid.

A method of predicting the temperature of a resistive heating element in a heating system is provided. The method includes obtaining resistance characteristics of resistive heating elements and compensating for variations in the resistance characteristics over a temperature regime. The resistance characteristics of the resistive heating element include, but are not limited to, inaccuracies in resistance measurements due to strain-induced resistance variations, variations in resistance due to the rate of cooling, shifts in power output due to exposure to temperature, resistance to temperature relationships, non-monotonic resistance to temperature relationships, system measurement errors, and combinations of resistance characteristics. The method includes interpreting and calibrating resistance characteristics based on a priori measurements and in situ measurements.

An exhaust system is provided that includes at least one exhaust aftertreatment unit provided in an exhaust fluid flow pathway and a thermal storage device disposed upstream from the exhaust aftertreatment unit. The thermal storage device is operable to store thermal mass and provide thermal insulation to enable a catalyst to maintain a minimum predetermined temperature for a minimum predetermined time. In one form, a heater is also provided proximate the thermal storage device, along with variations that include a secondary flow pathway for the thermal storage device.

A susceptor for use in a heated fluid flow system is provided. In one form, a susceptor is arranged within a conduit and adapted to absorb radiant energy from at least one heating element and inhibit the radiant energy from being absorbed by the at least one wall of the conduit and/or other components. In another form, the susceptor absorbs and inhibits the radiant energy from being absorbed by the outer wall of the conduit.

A heater system for an exhaust system is provided. The heater system includes a heater disposed in an exhaust conduit. The heater includes a plurality of heating elements disposed in the exhaust conduit. A heating control module controls the plurality of heating elements differently according to operating conditions specific to each heating element. In other forms, the heater system for an exhaust system has a plurality of heating zones, instead of a plurality of heating elements. The heating control module controls the plurality of heating zones differently according to operating conditions specific to each heating zone.

A fluid control system is provided that in one form includes a first flow channel, a second flow channel, a heater disposed in the second flow channel, and a fluid control device disposed upstream from the first and second flow channels. When the heater is turned on, the fluid control device changes a fluid flow rate through at least one of the first flow channel and the second flow channel. In another form, the fluid control system includes a bypass conduit, a heater disposed within the bypass conduit, and a fluid control device disposed near the inlet and outlet of the bypass conduit. In still another form, the fluid control system includes a regeneration device disposed downstream from at least one exhaust aftertreatment system and closes an outlet of the exhaust pipe.