Abstract: Methods and systems are provided for EGR valve diagnostic. In one example, a method includes providing a correction to a position of the EGR valve to compensate for an altitude of the vehicle. The compensation is based on a comparison of a pressure ratio to a curve rationalized with a barometric pressure.

Abstract: A turbocharged engine system with electric compressor arranged to inject a compressed fluid into the exhaust subsystem upstream of the turbine of the turbocharger such that, in use, the compressed fluid injected by the electric compressor into the exhaust subsystem maintains the speed of or accelerates the turbine, thereby maintaining or increasing the boost pressure supplied to the turbocharged internal combustion engine. A method of controlling the boost pressure supplied to an internal combustion engine by a turbocharger, said method comprising the steps of: producing a stream of compressed fluid; injecting the stream of compressed fluid into an exhaust stream of the internal combustion engine to produce a pressure-boosted exhaust stream; and controlling the speed of a turbine of the turbocharger using the pressure-boosted exhaust stream to control the boost pressure supplied to the internal combustion engine.

Abstract: A system comprising an electronic control unit configured to provide an intake manifold of an internal combustion engine with a mixture of fuel gas, air and exhaust gas with a lambda (?) of approximately 1 and an exhaust gas recirculation (EGR) content of about 10% to about 45%, wherein the internal combustion engine comprises a prechamber coupled to a main combustion chamber, wherein the main combustion chamber is formed in a cylinder by a piston and at least one cylinder head, wherein a source of a gas-air mixture into the prechamber comprises: an intake port of the main combustion chamber and a connection line between the intake port and a prechamber gas valve of the prechamber; or an intake manifold and a connection line between the intake manifold and the prechamber gas valve of the prechamber.

Abstract: An internal combustion engine for a motor vehicle includes an output shaft, an intake manifold, an exhaust manifold, an exhaust gas aftertreatment device disposed in the exhaust manifold, a heating element disposed in the exhaust manifold upstream of the exhaust gas aftertreatment device, an electrically assisted exhaust gas turbocharger, and a conduit element that extends inside the exhaust gas turbocharger and through which a heating medium is flowable. Via the conduit element at least a part of the heating medium is guidable through the exhaust gas turbocharger from the intake manifold into the exhaust manifold.

Abstract: A variable capacity turbocharger includes a turbine impeller, a gas inlet passage fluidly coupled to the turbine impeller, a nozzle vane located in the gas inlet passage, a drive assembly that rotates the nozzle vane, a drive chamber accommodating the drive assembly and including a region configured to store liquid in the drive chamber, and a liquid passage fluidly coupled with the drive chamber and configured to discharge the liquid from the drive chamber. A surface of the liquid passage has a greater surface roughness than the region of the drive chamber.

Abstract: Systems and methods regarding a ducted fuel injection (DFI) combustion system for an internal combustion engine can control an injection timing of a fuel injector to output fuel injections through at least one duct and into a combustion chamber of the internal combustion engine. The injection timing can include one or more pilot injections according to a predetermined range before top dead center (BTDC) for a combustion cycle; and a main injection into the combustion chamber for the combustion cycle after all of the one or more pilot injections. A first amount of the fuel injected for the main injection can be greater than a second amount of fuel injected for the one or more pilot injections. The predetermined range before top dead center (BTDC) of the one or more pilot injections can be from 85 to 40 degrees BTDC.

Abstract: Provided is an internal combustion engine control device capable of appropriately correcting a flow rate of EGR gas. Therefore, an internal combustion engine control device 20 includes moisture amount calculation units 301 and 302, a dew condensation calculation unit 303, and an EGR correction unit 304. The moisture amount calculation unit 301 calculates a total moisture amount contained in the mixed gas. The dew condensation calculation unit 303 calculates a dew condensation generation amount WQcon in an intercooler based on the total moisture amount. The EGR correction unit 304 corrects a flow rate of the EGR gas based on the dew condensation generation amount WQcon.

Abstract: The subject matter of this application is using novel biological reactors for the fermentation of gases into liquid products. More specifically, the subject matter relates to the use of a Multiple-Pass Trickle Bed Reactor (MP-TBR) for the anaerobic or aerobic and biological fermentation of gases generated from industrial processes and/or from the gasification of biomass and other organic carbon sources. The products may include, but are not limited to, ethanol and other valuable chemicals.

Abstract: An internal combustion engine system includes an internal combustion engine having a cylinder, an air intake system to feed air to the cylinder, an exhaust gas system to feed exhaust gas away from the cylinder, a turbocharger including a turbocharger turbine operatively connected to a turbocharger compressor, wherein the air intake system is arranged to feed intake air via the turbocharger compressor and wherein the exhaust gas system is arranged to feed exhaust gas via the turbocharger turbine so as to drive the turbocharger compressor, and wherein the internal combustion engine system further includes a positive displacement machine arranged in the exhaust gas system downstream of the turbocharger turbine. The internal combustion engine system further includes a variable drive unit to drive the positive displacement machine. The internal combustion engine system controls the drive unit so as to control a flow of exhaust gas through the positive displacement machine.

Abstract: An engine system has an internal combustion engine, a turbocharger provided with a compressor and with a turbine; and a supply line, which supplied air to the engine through said compressor; the supply line has a supplementary compression stage, which is distinct from the compressor and is controlled in combination with and adjustment of the turbine, in order to limit the back pressure of the exhaust gases flowing out of the engine; in particular, said compression stage is defined by an ejector.

Abstract: In an opposed-piston engine which includes a catalytic aftertreatment device in its exhaust system an exhaust gas condition indicating a catalyst temperature of the aftertreatment device is monitored. When the catalyst temperature is near or below a light-off temperature, a catalyst light-off procedure is executed to elevate the temperature of the catalyst.

Abstract: Systems and methods for treated exhaust gas recirculation (EGR) for an internal combustion engine are disclosed. The internal combustion engine has an exhaust manifold discharging exhaust gas and an intake manifold receiving forced air from a compressor. One or more exhaust treatment devices treat the exhaust gas and produce a treated exhaust gas. The EGR system includes an EGR line downstream of the one or more exhaust treatment devices and connected to the engine intake line downstream of the compressor, wherein the treated EGR line recirculates the treated exhaust gas to the intake manifold of the engine without passing through the compressor.

Abstract: An internal combustion engine includes a four-stroke combustion cylinder assembly configured for combustion of hydrogen gas within at least one combustion chamber of the combustion cylinder assembly such as to drive a crankshaft of the engine, an intake passage upstream of the cylinder assembly and an exhaust passage downstream of the cylinder assembly; a displacement compressor arranged within the intake passage, the displacement compressor being configured for compression of intake gas, an exhaust gas recirculation system configured for recirculating at least a portion of the exhaust from the exhaust passage to the displacement compressor.

Abstract: An EGR estimation method for estimating an EGR rate in an intake and exhaust system of an internal combustion engine, the intake and exhaust system including: an intake system including an air cleaner and an intake passage that connects the air cleaner and the engine, an exhaust system including an exhaust passage, and a supercharger that is provided in the intake passage and the exhaust passage, the intake and exhaust system including an EGR device including an EGR passage that connects the intake passage and the exhaust passage and an EGR valve, and the intake system including an intake bypass passage that connects an upstream pressure portion and a downstream pressure portion of the supercharger and a recirculation valve. The EGR estimation method includes: opening the recirculation valve during supercharging, and estimating the EGR rate after closing the EGR valve based on the EGR rate before opening the recirculation valve.

Abstract: A method of operating exhaust gas recirculation pump for an internal combustion engine including: providing an EGR pump assembly including an electric motor coupled to a roots device having rotors, the EGR pump operably connected to an internal combustion engine; providing an system controller; providing an EGR control unit linked to the EGR pump assembly; sending a speed command from the system controller to the EGR control unit; determining if a motor temperature and module temperature is within a predetermined target; outputting a desired speed signal; determining if a motor speed is within a predetermined target; determining if a motor voltage is within a predetermined target; and outputting a current to the electric motor controlling the speed of the electric motor and regulating an EGR mass flow rate.

Abstract: The subject matter of this specification can be embodied in, among other things, a gas mixer that includes a convergent-divergent nozzle comprising a convergent portion and a divergent portion and defining a first gas flow path, an air housing comprising an air inlet configured to supply air to the first gas flow path upstream of the convergent-divergent nozzle, a gas housing defining a second gas flow path and including a first gas inlet configured to receive a secondary gas and allow the secondary gas into a second gas flow path, and a gas nozzle positioned parallel to and centrally within the first gas flow path in a convergent portion of the convergent-divergent nozzle, the gas nozzle configured to supply the secondary gas to the first gas flow path upstream of the divergent portion.

Abstract: In a turbocharged internal combustion engine system including an eCompressor as a secondary air pump (SAP) for injecting air into an exhaust system of the ICE, controllable valves enable the turbocharger compressor and the SAP to provide two-stage compressed air to the intake of the ICE in certain operating conditions, or to feed the air via a secondary air injection line (SAI line) into the exhaust system in other conditions. A conduit is tapped off the discharge of the SAP and connects with discharge ducting from the turbocharger compressor, and an on/off valve configured for defined leakage in the “off” position controls flow through the conduit. When the air from the SAP is needed only for injection air, the leakage through the leaky valve into the intake system suppresses surge of the SAP.

Abstract: Upon a predetermined first diagnosis execution condition being met, an electronic control unit executes a first diagnosis process of diagnosing whether an exhaust gas recirculation device has an abnormality based on an amount of change that a measured value of an intake air pressure undergoes as a result of a change in an EGR valve position. When a predetermined second diagnosis execution condition is met and, moreover, the first diagnosis process is not being executed, the electronic control unit executes a second diagnosis process of diagnosing whether an exhaust gas cleaning filter has a fracture based on measured values of an incoming gas temperature and an outgoing gas temperature.

Abstract: An engine assembly comprising an internal combustion engine having a combustion chamber; an intake manifold for supplying air to the combustion chamber; a fuel injector for supplying fuel to the combustion chamber; an exhaust manifold for receiving exhaust gas released from the combustion chamber and a rotatable drive shaft, wherein combustion of fuel in air within the combustion chamber results in rotation of the drive shaft. The engine assembly further comprises a turbocharger system comprising a turbine and a compressor, wherein the turbine is configured to receive exhaust gas from the exhaust manifold, to recover energy from the exhaust gas, and to release the exhaust gas via a turbine outlet; and wherein the compressor is configured to receive energy from the turbine and thereby to compress air for use in combustion of fuel in the combustion chamber.

Abstract: Methods and systems are provided for merging recirculated exhaust gas (EGR) with fresh intake air in an intake passage. In one example, a method may include introducing EGR to the intake passage via an angled annular slot and flowing unmixed EGR and ambient air through an intake compressor inlet. Ambient air may flow to a center of the intake compressor while the EGR may flow along a periphery of the intake compressor inlet.

Abstract: A recirculation system for a power system is disclosed. The recirculation system may determine, according to a sequence for individually activating a plurality of turbochargers of an engine, that a designated turbocharger of the plurality of turbochargers is to be activated. The recirculation system may cause a recirculation valve of a recirculation line to open to increase an airflow between an intake manifold and a compressor of the designated turbocharger.

Abstract: A first intake manifold is connected to a first group of cylinders, a second distinct intake manifold is connected to a second group of cylinders and a first, respectively a second, exhaust manifold for receiving the exhaust gas emitted from the first, respectively the second, group of cylinders. An EGR line is connected to the first and second exhaust manifolds. A mixing unit includes a four-way valve having a first inlet connected to an air line, a second inlet connected to the EGR line, a first outlet connected to the first intake manifold and a second outlet connected to the second intake manifold. The first inlet is connected to the air line, the second inlet is connected to the EGR line. The first outlet and said second outlet form a substantially X-shape. The first inlet and said second inlet are coaxial. The first outlet and second outlet are coaxial such that the first inlet is diagonally facing the second inlet and the first outlet is diagonally facing the second outlet.

Abstract: An engine system includes an engine with an intake manifold and an exhaust manifold, a turbocharger including a turbine in communication with the exhaust manifold and a compressor in communication with the intake manifold, and a regulator configured to control a flow of exhaust gas through the turbine. A controller of the engine system is operably connected with the regulator and is configured to monitor an engine load and an exhaust gas temperature during operation of the engine, identify a proscribed engine NOx emissions level based on the engine load and the exhaust gas temperature and, when the proscribed engine NOx emissions level is identified, modify the flow of exhaust gas through the turbine to reduce the energy extracted from the exhaust gas by the turbine and reduce a drive power provided to the compressor, thereby reducing a flow of intake air provided to the intake manifold by the compressor.

Abstract: Systems, apparatus, and methods are disclosed that include a divided exhaust engine with at least one pair of primary EGR cylinders and a plurality of pairs of non-primary EGR cylinders. The pair of primary EGR cylinders can be connected to an intake with an EGR system that lacks an EGR cooler. In another embodiment, the cylinder pairs include exhaust flow paths that join in the cylinder head to form a common exhaust outlet for each cylinder pair in the cylinder head that is connected directly to the EGR system or to the exhaust system without an exhaust manifold.

Abstract: An exhaust gas recirculation system includes a first turbocharger and a second turbocharger connected in series. An outlet of a turbine of the second turbocharger is connected to an exhaust pipe. An inlet of a compressor of the second turbocharger is connected to the exhaust pipe by means of an EGR gas collection pipe, and an outlet of the compressor of the second turbocharger is connected to an intake manifold by means of a low-pressure EGR exhaust pipe. The system employs energy of exhaust gas to drive turbines of a two-stage turbocharging system, thereby increasing utilization of the exhaust gas and improving the economic efficiency of an engine. An engine is also disclosed.

Abstract: A system and method of integrating an engine having dynamic skip fire control with an exhaust gas recirculation system in a turbocharged internal combustion engine is described. An engine control system determines an appropriate firing pattern based at least in part on a desired exhaust gas recirculation flow rate. Signals from sensors in the intake manifold and exhaust system may also be used as part of a feedback loop to determine a desired exhaust gas recirculation flow rate.

Abstract: The invention relates to an internal combustion engine comprising a crankshaft, one or more cylinders including a cylinder head, a piston, a combustion chamber, one or more intake valves, one or more exhaust valves, an intake system configured for feeding intake air to the engine, an exhaust system configured for conveying exhaust gas away from the engine, a pressure charging system connected to the intake system and an exhaust gas recirculation (EGR) system arranged to feed branched off exhaust gas from the exhaust system to the intake system via an EGR conduit wherein: —the internal combustion engine includes a valve actuation device configured to allow for late or early closing of the intake valves in accordance with late or early Miller-type valve timing, and wherein—the EGR system includes a gas feeding device configured to feed exhaust gas through the EGR conduit in modes of operation wherein the pressure in the intake system exceeds the pressure in the exhaust system.

Abstract: In accordance with one aspect of the present disclosure, a turbocharger includes a compressor having a compressor wheel, a turbine provided within a housing, and an exhaust gas recirculation (EGR) flow path. The EGR flow path includes a first fluid connection in the housing and located in proximity to the turbine, a second fluid connection located in proximity to a trailing edge of the compressor wheel, an EGR control valve disposed between the first fluid connection and the second fluid connection, the EGR control valve configured to selectively operate the turbocharger in a low-heat mode having an EGR up to 50% and an operational mode having an EGR rate typically less than 35%.

Abstract: The present invention is related to the housing (60) of an exhaust turbine (32) of a turbocharger comprising a first volute (61) and a second volute (62), each of the volutes (61,62) ending in respective first and second guide tongues (64,66). The gap between the first guide tongue (64) and turbine wheel is smaller than the gap between the second guide tongue (66) and turbine wheel. This tongue asymmetry allows for control of the pulse amplitude emitted when a blade of the turbine wheel passes by each respective tongue. Moreover, by increasing the wheel-to-tongue distance of only the second guide tongue (66) durability requirements can be met.

Abstract: Systems and methods for treated exhaust gas recirculation (EGR) for an internal combustion engine are disclosed. The internal combustion engine has an exhaust manifold discharging exhaust gas and an intake manifold receiving forced air from a compressor. One or more exhaust treatment devices treat the exhaust gas and produce a treated exhaust gas. The EGR system includes an EGR line downstream of the one or more exhaust treatment devices and connected to the engine intake line downstream of the compressor, wherein the treated EGR line recirculates the treated exhaust gas to the intake manifold of the engine without passing through the compressor.

Abstract: The invention provides a method for controlling an internal combustion engine (2) for controlling an internal combustion engine (2) comprising at least one first cylinder (201) and at least one second cylinder (202) with respective reciprocating pistons, an intake guide (305) arranged to guide air from a fresh air intake arrangement (303) to the first and second cylinders (201, 202), a fuel system (801, 802) arranged to inject fuel into the first and second cylinders (201, 202), a first exhaust guide (401) and a second exhaust guide (402) arranged to guide gases from the first and second cylinders (201, 202), respectively, towards an exhaust after treatment system (7), the method comprising—receiving (S1) in the first cylinder (201), from the intake guide (305), air from the fresh air intake arrangement (303) or gases including air from the fresh air intake arrangement (303), —expelling from the first cylinder (201), to the first exhaust guide (401), gases in the form of the air received in the first cylinder

Abstract: An exhaust gas recirculation (EGR) passage is connected with an intake passage (a bypass passage bypassing a supercharger) of an engine. The EGR passage includes, in a position close to a connection port to the intake passage, an expanding portion in which a passage cross-sectional area expands and which lowers a flow speed of EGR gas so as to reduce an uneven flow, in the connection port, of the EGR gas flowing into the intake passage.

Abstract: A method and a turbine-compressor assembly of a system having an engine includes an upstream valve coupled with a compressor and a turbine-compressor device, a downstream valve coupled with a turbine and the device, and a controller to control the upstream, downstream, and a control valve. The controller selectively operates the device in a plurality of operating modes. In a turbine mode of operation, the upstream valve directs inlet air to the compressor, the turbine receives engine exhaust, the downstream valve directs first turbine exhaust from the turbine to the device, and the control valve directs second turbine exhaust from the device to an outlet. In a compressor mode of operation, the control valve directs the inlet air to the device, the upstream valve directs first compressed air from the device to the compressor, and the downstream valve directs the first turbine exhaust from the turbine to the outlet.

Abstract: A cooling system is mounted on an internal combustion engine equipped with an EGR device including an EGR passage. The cooling system includes: an intercooler disposed in the intake passage; an EGR cooler disposed in the EGR passage; a condensed water discharger configured to discharge condensed water generated in the EGR cooler from the EGR passage; a radiator configured to cool a first coolant to or below a dew point of the EGR gas flowing into the EGR cooler; a first circulation flow path configured to circulate the first coolant in the order of the radiator, the EGR cooler, and the intercooler; and a pump disposed in the first circulation flow path and configured to circulate the first coolant such that an outlet gas temperature of the EGR cooler is equal to or lower than the dew point of the EGR gas flowing into the EGR cooler.

Abstract: Methods and systems are provided for a turbocharger. A system comprises a variable geometry turbocharger comprising a plurality of vanes, wherein the plurality of vanes is operated during a low-load transient event to conserve boost pressure from a previous high-load transient event to reduce lag during a proceeding high-load transient event.

Abstract: Methods and systems are provided for an EGR system. In one example, a system comprises a first turbocharger configured to increase an intake gas pressure and a second turbocharger configured to increase an exhaust gas pressure. The second turbocharger is dedicated to only compressing exhaust gases flowing to an intake passage.

Abstract: A method for warming an aftertreatment system of an engine system while an engine of the engine system is not running comprising starting at least one of an electric compressor and an electric heater using stored electrical energy and passing air through the engine system to at least a portion of the aftertreatment system when the engine of the engine system is not running.

Abstract: The disclosure relates to a gasoline engine comprising an exhaust gas line which can be connected to an exhaust manifold of the gasoline engine, an intake line which can be connected to an intake manifold of the gasoline engine, a charge air compressor which is arranged in the intake line, and a turbine which is arranged in the exhaust gas line. The exhaust gas line has at least one bypass line with a bypass throttle valve, said line branching off from the exhaust gas line at a branch upstream of the turbine and branching back into the exhaust gas line at an opening downstream of the turbine.

Abstract: An internal combustion engine having a turbocharger with variability at the compressor inlet, and a turbocharger. An internal combustion engine having a turbocharger, and a turbocharger, are described. A device which both performs a change in the cross section of the compressor inlet and brings about an adjustment of the exhaust gas recirculation rate is arranged in the region of the compressor inlet. As a result, the turbocharger is of space-saving and low-cost construction in the compressor inlet region.

Abstract: An internal combustion engine system including an internal combustion engine and an exhaust gas recirculation circuit connecting an exhaust manifold of the engine to an intake manifold of the engine, the circuit including at least one reed valve, an EGR valve, that is arranged downstream of the reed valve on the path of exhaust gas flowing from the exhaust manifold to the intake manifold and an EGR line connecting the reed valve to the EGR valve. The system further includes a bypass line for gas, connecting the EGR line to an exhaust line of the engine and controller for controlling the flow of gas discharged through the bypass line.

Abstract: The present disclosure relates to exhaust treatment systems and engine systems. In one implementation, an engine system comprises an engine comprising an intake manifold and an exhaust manifold, the engine configured to combust a fuel-air mixture received via the intake manifold and produce a flow of exhaust gases via the exhaust manifold. The engine system also comprises a turbocharger comprising a turbine, an exhaust passageway fluidly connecting the exhaust manifold of the engine to the turbine and an intake passageway fluidly connected to the intake manifold of the engine for supplying the fuel-air mixture, a catalyzed member positioned along the exhaust passageway between the engine and the turbine, and an exhaust gas recirculation (EGR) loop fluidly connected downstream of the catalyzed member and fluidly connected to the exhaust passageway and the intake passageway.

Abstract: Various systems are provided for a charge-air cooler system. In one example, a system includes a turbocharger system having at least one compressor and one turbine and configured to provide charge air to an engine. The system also includes a charge-air cooler system having at least one charge-air cooler arranged below the at least one compressor, a turbocharger bracket arranged directly below the charge-air cooler system and shaped to mount the charge-air cooler and the turbocharger system to the engine, and a stator adapter physically coupling an alternator to the engine. The stator adapter includes an accessibility window arranged below the charge-air cooler system. The at least one charge-air cooler is closer to the accessibility window than the turbocharger system.

Abstract: The disclosure relates to an exhaust gas conduction system for a gasoline engine, comprising an exhaust gas line which can be connected to an exhaust manifold of the gasoline engine, an intake line which can be connected to an intake manifold of the gasoline engine, a charge air compressor which is arranged in the intake line, and a turbine which is arranged in the exhaust gas line. The exhaust gas line has at least one bypass line with a bypass throttle valve, said line branching off from the exhaust gas line upstream of the turbine and branching back into the exhaust gas line at an opening downstream of the turbine. At least one exhaust gas recirculation line with an EGR throttle valve is provided, said line opening into the intake line, wherein the exhaust gas recirculation line branches off from the bypass line at a branch, and the bypass throttle valve is arranged upstream of the branch of the exhaust gas recirculation line.

Abstract: Methods and systems for an engine controller are described. In one example, the engine controller includes a reference control system and a disturbance rejection control system. The engine controller avoids use of integral feedback in the reference control system, while permitting integral feedback in the disturbance rejection control system, to improve controller response without unduly increasing engine pumping work.

Abstract: Methods and systems are provided for an aftertreatment system. In one example, a method comprises regenerating a NOx trap during an engine shut-down event. The method further comprises reversing a direction of flow of a gas through a HP-EGR passage during the regenerating.

Abstract: A determination is made whether or not the condition that the amount V of condensed water remaining in an intake passage has exceeded a predetermined upper limit has been met, based on an input parameter associated with the amount V. If, during an engine operation in an unsupercharged mode, a determination is made that the condition has been met, a condensed water discharging operation of a supercharger is performed such that the condensed water remaining is discharged to a cylinder of the engine through operation of the supercharger.

Abstract: Methods are provided for engines. In one example, method, at higher engine load, cool compressed air is drawn into an engine via an air intake passage, and at lower engine load, ambient air is drawn into the engine via a duct while retaining cooled compressed air in the air intake passage. The compressed air may be released from the air intake passage based on heat transferred to the compressed air during the lower engine load, in at least one example.

Abstract: Systems, methods and apparatus are disclosed for producing a target compressor outlet pressure that is based on a desired pressure differential across an intake throttle of an internal combustion engine and an intake manifold pressure by opening or closing a compressor recirculation valve and a turbocharger wastegate to commanded positions based on the target compressor outlet pressure.

Abstract: A method for operating an engine that includes a turbocharger with a wastegate is described. In one example, the method includes oscillating a position of the wastegate during cold engine starting as a function of a speed of an engine. The wastegate position may be adjusted to follow a square wave, sinusoidal wave, or triangle wave.

Abstract: Methods and systems are provided for a cooling arrangement of an engine. In one example, a method comprises flowing coolant from a high temperature coolant circuit or a low temperature coolant circuit to a fresh air heat exchanger in response to a condensate likelihood.