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 device and to a method are provided for using part of the heat given off by an internal combustion engine. A waste-heat-collecting housing surrounds at least part of an exhaust-gas manifold and/or at least part of an engine-side segment of an exhaust-gas system of the internal combustion engine. Air contained in the waste-heat-collecting housing is heated, and the heated air is used indirectly or directly to heat at least one of air that is introduced in a passenger compartment of the vehicle, cooling liquid of the internal combustion engine and oil in an oil circuit of the internal combustion engine. The waste-heat-collecting housing is similarly useable in a stationary apparatus having an internal combustion engine.

A device and to a method are provided for using part of the heat given off by an internal combustion engine. A waste-heat-collecting housing surrounds at least part of an exhaust-gas manifold and/or at least part of an engine-side segment of an exhaust-gas system of the internal combustion engine. Air contained in the waste-heat-collecting housing is heated, and the heated air is used indirectly or directly to heat at least one of air that is introduced in a passenger compartment of the vehicle, cooling liquid of the internal combustion engine and oil in an oil circuit of the internal combustion engine. The waste-heat-collecting housing is similarly useable in a stationary apparatus having an internal combustion engine.

A heat exchanger assembly includes a main heat exchanger that receives a main hot air; a secondary heat exchanger operatively adjacent to the main heat exchanger; wherein the secondary heat exchanger receives a secondary hot air; wherein the main hot air and the secondary hot air are from two different, direct air sources; wherein a hot air channel of only one of the main and the secondary heat exchangers includes a catalytic coating; and a temperature control that controls the temperature of only one of the main hot air and the secondary hot air into the hot air channel.

A heat exchanger assembly includes a main heat exchanger that receives a main hot air; a secondary heat exchanger operatively adjacent to the main heat exchanger; wherein the secondary heat exchanger receives a secondary hot air; wherein the main hot air and the secondary hot air are from two different, direct air sources; wherein a hot air channel of only one of the main and the secondary heat exchangers includes a catalytic coating; and a temperature control that controls the temperature of only one of the main hot air and the secondary hot air into the hot air channel.

An apparatus includes an exhaust gas and cabin air heat exchanger having an exhaust gas inlet, an exhaust gas outlet, a cabin air inlet and a cabin air outlet whereby heat is directly exchanged between exhaust gases and cabin air of a motor vehicle. A related method of heating cabin air in a motor vehicle is also disclosed.

An apparatus includes an exhaust gas and cabin air heat exchanger having an exhaust gas inlet, an exhaust gas outlet, a cabin air inlet and a cabin air outlet whereby heat is directly exchanged between exhaust gases and cabin air of a motor vehicle. A related method of heating cabin air in a motor vehicle is also disclosed.

A vehicular heat management system includes a heat medium circuit, a heat source portion, and a device. A heat medium cooling an engine circulates in the heat medium circuit. The heat source portion heats the heat medium. The device is configured to function and heat the heat medium when the heat medium flowing into the device is at or above a predetermined temperature. When the engine is being warmed up, heat generated by the heat source portion is supplied to the device in preference to the engine. According to this, since the heat generated by the heat source portion is supplied to the device in preference to the engine when the engine is being warmed up, the engine can be warmed up early.

A vehicular heat management system includes a heat medium circuit, a heat source portion, and a device. A heat medium cooling an engine circulates in the heat medium circuit. The heat source portion heats the heat medium. The device is configured to function and heat the heat medium when the heat medium flowing into the device is at or above a predetermined temperature. When the engine is being warmed up, heat generated by the heat source portion is supplied to the device in preference to the engine. According to this, since the heat generated by the heat source portion is supplied to the device in preference to the engine when the engine is being warmed up, the engine can be warmed up early.

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.