A heating system includes at least one electric heater disposed within the fluid flow system. A control device includes a microprocessor and is configured to determine a temperature of the at least one electric heater based on a model and at least one input from the fluid flow system. The control device is configured to provide power to the at least one electric heater based on the temperature of the at least one electric heater.

An exhaust system is provided that includes an exhaust aftertreatment unit, first and second exhaust pathway in communication with and upstream of the exhaust aftertreatment unit, a thermally activated flow control device operable in a first and second mode, and a thermal storage device. In the first mode, the flow control device permits exhaust to flow to the aftertreatment unit through the first pathway and inhibits flow through the second pathway. In the second mode, the flow control device permits exhaust flow to the aftertreatment unit through the second pathway and inhibits flow through the first pathway. The flow control device may switch between the first and second modes based on a change of temperature. The thermal storage device is within the second pathway, stores thermal mass, and provides thermal insulation to enable a catalyst of the aftertreatment unit to maintain a predetermined temperature for a predetermined time.

A heater system for an LED light assembly having a lens includes a flexible composite positioned around an outer surface of the lens. The flexible composite includes a polymer base layer, a plurality of conductive buses provided on the base layer, and a resistive layer electrically connecting the plurality of buses to form a circuit. The resistive layer includes conductor particles dispersed in a polymer matrix. The resistive layer has a crystalline first condition prior to applying electricity to one of the buses and an amorphous second condition in response to applying electricity to one of the buses.

A control system for use in a fluid flow application includes a heater and a control device. The heater has at least one resistive heating element and the heater is operable to heat fluid. The control device determines at least one flow characteristic of a fluid flow based on a heat loss of the at least one resistive heating element and determines a mass flow rate of the fluid based on the at least one flow characteristic and a property of the at least one resistive heating element. And the property of the at least one resistive heating element includes a change in resistance of the at least one resistive heating element under a given heat flux density.

A method for operating a heater system including a resistive heating element having a material with a non-monotonic resistivity vs. temperature profile is provided. The method includes heating the resistive heating element to within a limited temperature range in which the resistive heating element exhibits a negative dR/dT characteristic, operating the resistive heating element within an operating temperature range that at least partially overlaps the limited temperature range, and determining a temperature of the resistive heating element such that the resistive heating element functions as both a heater and a temperature sensor. The resistive heating element can function as a temperature sensor in a temperature range between about 500 C. and about 800 C., and the non-monotonic resistivity vs. temperature profile for the material of the resistive heating element can have a local maximum and a local minimum.

A heater is provided that includes at least one resistive heating element having a material with a non-monotonic resistivity vs. temperature profile and exhibiting a negative dR/dT characteristic over a predetermined operating temperature range along the profile. The heater can include a plurality of circuits disposed in a fluid path to heat fluid flow.

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 control system for use in a fluid flow application is provided. The control system includes a heater having at least one resistive heating element. The heater is adapted to heat the fluid flow. The control system further includes a control device that uses heat loss from at least one resistive heating element to determine flow characteristics of the fluid flow.

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 method of predicting temperature of at least one location in a fluid flow system that has a heating system for heating fluid. The method includes obtaining a mass flow rate of fluid flow of the fluid flow system, obtaining at least one of a fluid outlet temperature and a fluid inlet temperature of a heater of the heating system, obtaining power provided to the heater, and calculating temperature at the at least one location based on a model of the fluid flow system and the obtained mass flow rate, fluid outlet temperature, and fluid inlet temperature.