The heat insulation structure for a component of an exhaust system of a piston engine is arrangeable around the component such that an air space is formed between the component and the heat insulation structure, and includes an outer shell layer a middle shell layer that is arranged inside the outer shell layer, and a first inner shell layer that is arranged inside the middle shell layer. A first air gap is arranged between the outer shell layer and the middle shell layer, a first insulation layer is arranged between the middle shell layer and the first inner shell layer, and the outer shell layer is provided with venting apertures for natural ventilation of the first air gap.

A system includes a first heater positioned in or proximate to an exhaust aftertreatment system in exhaust gas-receiving communication with an engine, a second heater positioned downstream of the first heater, and a controller coupled to the first and second heaters. The controller is structured to activate the second heater in response to determining that a compound deposit is likely present.

An exhaust heat recovery device including a heat exchange portion, an exhaust branch portion, and an exhaust distribution portion, wherein the heat exchange portion comprises a pillar-shaped honeycomb body having a first end face and a second end face, and a casing accommodating the honeycomb body, the exhaust branch portion has a branch path that branches a path of exhaust gas flowing into the honeycomb body into a central portion and an outer circumferential portion in a cross-section orthogonal to an axial direction of the honeycomb body, and the exhaust distribution portion has an exhaust distribution mechanism that adjusts a heat recovery amount by changing an airflow resistance of the path of the exhaust gas in the central portion of the honeycomb body and varying the exhaust amount passing through the path of the exhaust gas in the outer circumferential portion of the honeycomb body.

An engine exhaust system is accommodated in a counterweight portion without reducing either the efficiency of cooling by a radiator or the efficiency of purifying exhaust gas by an exhaust gas purification device. A body has a work device provided at the front and the counterweight portion at the rear. A ventilation path provided in the counterweight portion includes an elevated part formed between a bottom of a front portion and a bottom of a rear portion. The purification device and a muffler are disposed in the rear portion of the ventilation path so as to be positioned one above the other with the purification device lying above the muffler and having an upper portion protruding above the bottom of the front portion of the ventilation path. A windbreak plate made from a heat insulating material is disposed forward from the purification device so as to face the latter.

A catalyst device includes a catalyst, a heating element, and a case. A direction in which exhaust gas flows through an exhaust passage is defined as a gas discharging direction. The case includes an end portion on an upstream side in the gas discharging direction. The heating element includes an end on an upstream side in the gas discharging direction. The end portion of the case is an insulating portion that insulates electricity and protrudes toward an upstream side of the end of the heating element in the gas discharging direction. The catalyst device further includes an outer tube that is separated from the end portion of the case in a radial direction to cover the end portion. The outer tube is formed by a turbine housing that houses a turbine wheel of the forced-induction device.

A catalyst device includes a catalyst support, a tubular portion, which accommodates the catalyst support, a holding mat, which holds the catalyst support, an insulator provided over the outer circumferential surface of the tubular portion, and a heat insulating member arranged between the insulator and the tubular portion. The region of the outer circumferential surface of the tubular portion between the upstream end and the downstream end in the exhaust gas flowing direction is divided into two subregions arranged in a direction of the axis of the tubular portion. Of the two subregions, the subregion on the upstream side is defined as an upstream subregion, and the subregion on the downstream side is defined as a downstream subregion. The area that is covered with the heat insulating member in the downstream subregion is smaller than the area that is covered with the heat insulating member in the upstream subregion.

A system includes a first heater positioned in or proximate to an exhaust aftertreatment system in exhaust gas-receiving communication with an engine, a second heater positioned downstream of the first heater, and a controller coupled to the first and second heaters. The controller is structured to: determine, based on information indicative of a temperature regarding the exhaust aftertreatment system, that the temperature regarding the exhaust aftertreatment system is below a predefined temperature threshold; determine that the second heater is in or likely in an error state; and control a temperature regarding the exhaust aftertreatment system using the first heater in response to determining that the second heater is in or likely in the error state, wherein the first heater controls the temperature regarding the exhaust aftertreatment system after a temperature regarding an engine intake air is at or above a predefined air intake temperature threshold.

An engine exhaust system is accommodated in a counterweight portion without reducing either the efficiency of cooling by a radiator or the efficiency of purifying exhaust gas by an exhaust gas purification device. A body has a work device provided at the front and the counterweight portion at the rear. A ventilation path provided in the counterweight portion includes an elevated part formed between a bottom of a front portion and a bottom of a rear portion. The purification device and a muffler are disposed in the rear portion of the ventilation path so as to be positioned one above the other with the purification device lying above the muffler and having an upper portion protruding above the bottom of the front portion of the ventilation path. A windbreak plate made from a heat insulating material is disposed forward from the purification device so as to face the latter.

A processing system 100 includes a heat insulating pipe 12, a temperature measuring device 19, and a control device 20. The heat insulating pipe 12 has an inner pipe and an outer pipe. An airtight space is formed between the inner pipe and the outer pipe. A fluid having a temperature lower than that of an indoor space in which the heat insulating pipe 12 is placed is flown within the inner pipe. The temperature measuring device 19 measures a temperature of a surface of the heat insulating pipe 12. The control device 20 is controls a pressure within the airtight space by controlling an exhaust device 16 configured to exhaust a gas within the airtight space based on the temperature of the surface of the heat insulating pipe 12 and a dew-point temperature calculated from a humidity and the temperature of the indoor space.

A heat recovery device comprises a valve body inwardly defining a direct flow path for exhaust gases from an inlet to an outlet, a heat exchanger comprising a flow passage for the exhaust gases emerging in an inlet zone of the valve body, and a gate positioned in the valve body. The heat recovery device comprises a guide wall positioned in the direct flow path at the inlet zone, arranged to guide the exhaust gases from the inlet toward the cutoff section away from the inlet zone when the gate frees the direct flow path, and delimiting at least one orifice to allow the exhaust gases to go to the inlet zone when the gate closes off the direct flow path.