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.

Disclosed herein is an exhaust heat recovery apparatus for a vehicle, in which a heat accumulator has improved heat accumulation performance and heat exchange performance, whereby an engine can be rapidly warmed up in a cold start so that fuel efficiency can be enhanced, a pollutant emission rate can be reduced, and it is possible to heat a passenger compartment immediately after the engine starts.

Methods and systems are provided for a heat exchanger phase change material installed as a component of a variable exhaust tuning system. In one example, a method may include absorbing excess heat energy from exhaust gases during and after an engine-on event within a heat exchanger material, releasing heat energy stored in the heat exchanger material during and after an engine-off event, and heating an adjustable exhaust valve with the heat energy stored in the heat exchanger material.

Methods and apparatuses are provided for operating an internal combustion engine of a vehicle. The internal combustion engine includes an exhaust gas system having an air intake pipe configured to direct flow of air to an internal combustion engine and an exhaust pipe configured to direct flow of an exhaust gas from the internal combustion engine. The exhaust gas system also has an exhaust gas recirculation circuit to direct at least a portion of the flow of the exhaust gas from the exhaust pipe to the air intake pipe. A stimulus is generated via an event associated with an increased risk of condensation of exhaust gas constituents in an exhaust gas recirculation cooler. Heat is supplied to at least one of the air intake pipe, the exhaust pipe, or the exhaust gas recirculation circuit in response to the stimulus.

A vehicle exhaust system is provided and comprises a catalyst positioned in an exhaust passage of a vehicle. The catalyst is in the form of a washcoat supported on a substrate. The system includes a phase change material located adjacent to the catalyst to maintain the temperature of the catalyst between engine shut-down and subsequent start-up as well as to regulate the temperature during engine operation. In some embodiments, the phase change material comprises particles of a metal or metal alloy encapsulated in a ceramic material. The metal or metal alloy is adapted to have a phase change that occurs within a temperature range wherein the catalyst is active.

An exhaust system for a motor vehicle, with an exhaust pipe for discharging exhaust of a device that produces an exhaust. A heat accumulator, which surrounds the exhaust pipe in the peripheral direction with respect to a longitudinal central axis of the exhaust pipe, is present, at least in regions thereof, and, in the radial direction between the exhaust pipe and the heat accumulator over at least a portion of the longitudinal extension the heat accumulator, a cross-section adjusting element for adjusting a passage cross section is arranged between the exhaust pipe and the heat accumulator. The cross-section adjusting element has a first holed pipe, which surrounds the exhaust pipe, and a second holed pipe, which surrounds the first holed pipe. The first holed pipe and the second holed pipe can be shifted in position relative to each other for adjusting the passage cross section.

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 system and method for treating turbine exhaust gas includes an exhaust gas discharge structure, a catalytic exhaust gas treatment device, at least two heat exchangers and a district heating system. The catalytic exhaust gas treatment device is positioned at least partially within the exhaust gas discharge structure. A first heat exchanger is positioned at least partially within the exhaust gas discharge structure and upstream of the catalytic exhaust gas treatment device to remove heat from an exhaust gas by transferring heat to a working fluid. A second heat exchanger is positioned at least partially within the exhaust gas discharge structure downstream of the catalytic exhaust gas treatment device to remove heat from the exhaust gas that has passed though the device by transferring heat to the working fluid. A pump drives the working fluid between the first heat exchanger, the district heating system and the second heat exchanger.

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.

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.