A heat recovery device includes: a honeycomb structure including an outer peripheral wall having at least one outer peripheral surface, and partition walls arranged on an inner side of the outer peripheral wall, the partition walls defining a plurality of cells each extending from a first end face to a second end face to form a flow path for a first fluid; a thermoelectric conversion element arranged to face the outer peripheral surface of the outer peripheral wall; a cylindrical member that circumferentially covers the honeycomb structure in which the thermoelectric conversion element is arranged; a casing arranged at an interval so as to form a flow path for a second fluid, the casing being arrange on a radially outer side of the cylindrical member; and a pressing member being configured to press the cylindrical member against the thermoelectric conversion element. The cylindrical member has one or more slit portions.

An exhaust energy recovery system (EERS) and associated methods for an engine are disclosed. An embodiment of an EERS, for example, includes an inlet duct that is configured to divert exhaust gas from an exhaust duct of the engine into the recovery system and an outlet duct configured to return the exhaust gas to the exhaust duct downstream of the inlet duct. The recovery system is configured to heat components or fluids associated with engine to operating temperatures. The recovery system may be part of a mobile power system that is mounted to a single trailer and includes an engine and a power unit such as a high pressure pump or generator mounted to the trailer. Methods of operating and purging recovery systems are also disclosed.

An exhaust energy recovery system (EERS) and associated methods for an engine are disclosed. An embodiment of an EERS, for example, includes an inlet duct that is configured to divert exhaust gas from an exhaust duct of the engine into the recovery system and an outlet duct configured to return the exhaust gas to the exhaust duct downstream of the inlet duct. The recovery system is configured to heat components or fluids associated with engine to operating temperatures. The recovery system may be part of a mobile power system that is mounted to a single trailer and includes an engine and a power unit such as a high pressure pump or generator mounted to the trailer. Methods of operating and purging recovery systems are also disclosed.

A bottoming cycle power system includes a turbine-generator. The turbine-generator includes a turbo-expander and turbo-compressor disposed on a turbo-crankshaft. The turbo-expander is operable to rotate the turbo-crankshaft as a flow of exhaust gas from a combustion process passes through the turbo-expander. The turbo-compressor is operable to compress the flow of exhaust gas after the exhaust gas passes through the turbo-expander. An exhaust gas heat exchanger includes first and second flow paths operable to exchange heat therebetween. The first flow path is operable to receive the flow of exhaust gas from the turbo-expander prior to the exhaust gas being compressed by the turbo-compressor. The second flow path is operable to receive the flow of exhaust gas from the turbo-compressor after the exhaust gas has been compressed by the turbo-compressor.

A bottoming cycle power system includes a turbine-generator. The turbine-generator includes a turbo-expander and turbo-compressor disposed on a turbo-crankshaft. The turbo-expander is operable to rotate the turbo-crankshaft as a flow of exhaust gas from a combustion process passes through the turbo-expander. The turbo-compressor is operable to compress the flow of exhaust gas after the exhaust gas passes through the turbo-expander. An exhaust gas heat exchanger includes first and second flow paths operable to exchange heat therebetween. The first flow path is operable to receive the flow of exhaust gas from the turbo-expander prior to the exhaust gas being compressed by the turbo-compressor. The second flow path is operable to receive the flow of exhaust gas from the turbo-compressor after the exhaust gas has been compressed by the turbo-compressor.

A method for exhaust gas aftertreatment is provided, the method comprising: a) providing a nitrogen oxide-containing raw exhaust gas, b) introducing the nitrogen oxide-containing raw exhaust gas into a catalytic evaporator (1), c) introducing a urea solution and a fuel into the catalytic evaporator (1), as a result of which a reducing agent is obtained, and d) supplying the reducing agent to an exhaust gas aftertreatment system (8). Alternatively or in addition, a device for producing a reducing agent may be provided, a reducing agent produced with same, and the use of these objects.

An exhaust gas heat exchanger may include a tube bundle and a housing through which a coolant is flowable. The tube bundle may include a plurality of exhaust gas-conducting tubes held in a first tube base and a second tube base. The housing may enclose the tube bundle and may have face ends delimited by the first tube base and the second tube base. The housing may include a coolant inlet arranged in a region of the second tube base and a coolant outlet arranged in a region of the first tube base such that the coolant flows in counter flow relative to the exhaust gas. A plurality of coolant bypass passages may be arranged between the tube bundle and the housing. At least a subset of the plurality of coolant bypass passages may be at least partly blocked by an inlay structured and arranged to steer a coolant flow.

An exhaust gas heat exchanger may include a tube bundle and a housing through which a coolant is flowable. The tube bundle may include a plurality of exhaust gas-conducting tubes held in a first tube base and a second tube base. The housing may enclose the tube bundle and may have face ends delimited by the first tube base and the second tube base. The housing may include a coolant inlet arranged in a region of the second tube base and a coolant outlet arranged in a region of the first tube base such that the coolant flows in counter flow relative to the exhaust gas. A plurality of coolant bypass passages may be arranged between the tube bundle and the housing. At least a subset of the plurality of coolant bypass passages may be at least partly blocked by an inlay structured and arranged to steer a coolant flow.

A heat exchanger (4) has fluid flow channels (6) with at least one heat exchanging surface (10) which has an undulating surface section for which the surface profile varies along a predetermined direction such that at a first edge (E1) the surface profile follows a first transverse wave (20), at a second edge (E)2 the surface profile follows a second transverse wave (22) and at an intermediate point I between the edges the surface profile follows a third transverse wave (24). The third transverse wave (24) has a different phase, frequency or amplitude to the first and second transverse waves so that chevron-shaped ridges and valleys are formed. This improves the mixing of fluid passing through the channel and hence the heat exchange efficiency.

A heat exchanger (4) has fluid flow channels (6) with at least one heat exchanging surface (10) which has an undulating surface section for which the surface profile varies along a predetermined direction such that at a first edge (E1) the surface profile follows a first transverse wave (20), at a second edge (E)2 the surface profile follows a second transverse wave (22) and at an intermediate point I between the edges the surface profile follows a third transverse wave (24). The third transverse wave (24) has a different phase, frequency or amplitude to the first and second transverse waves so that chevron-shaped ridges and valleys are formed. This improves the mixing of fluid passing through the channel and hence the heat exchange efficiency.