Abstract: The invention relates to a fluid valve, in particular for the exhaust gas from a motor vehicle engine, comprising a body (30) defining a main duct (31) and an auxiliary duct (32) for the flow of fluid, which auxiliary duct opens into the main duct (31). The valve also comprises: a flap (1) that can move between a closed position, preventing communication between the two ducts (31, 32), and an open position, allowing communication between said ducts (31, 32); and a gasket (2) against which the flap (1) bears when in the closed position. In addition, the above-mentioned body comprises a housing (37) for a motor for actuating the flap (1). According to the invention, the body (30) is configured to define a fluid lamina (38) between the gasket (2) and the housing (37).

Abstract: A cooler arrangement for connection to an exhaust gas manifold or to an exhaust gas outlet of an engine block of an internal combustion machine includes an exhaust gas cooler comprising at least one exhaust gas duct and a coolant jacket. The exhaust gas cooler is configured to be mounted at the engine block or at the exhaust gas manifold. An exhaust gas recirculation valve is configured to regulate an exhaust gas flow. An actuator is disposed on a side of the exhaust gas recirculation valve opposite the exhaust gas cooler. The actuator is configured to actuate the exhaust gas recirculation valve. A coolant duct segment is arranged between the exhaust gas manifold or the engine block and the actuator. The coolant duct segment is fluidically connected to the coolant jacket.

Abstract: A system and methods for routing condensate collected in a heat exchanger reservoir to either an air intake system or a position in the engine exhaust based on the type of contaminate in the condensate and operating parameters of the engine or the catalyst are described. In one particular example, condensate is routed to a first position along the engine air intake system in a first mode of operation, and a second position upstream of the catalyst along the engine exhaust in a second mode of operation, and a third position downstream of the catalyst along the engine exhaust in a third mode of operation. When substantially no contaminates are detected, the condensate may be routed into the engine exhaust upstream of the catalyst in order to cool the catalyst.

Abstract: An air induction system for a power source including a first compressor and a second compressor is disclosed. The air induction system includes an air feed passageway that directs compressed air from the second compressor to an area between a compressor wheel and a center housing in the first compressor to reduce oil consumption in the first compressor.

Abstract: Embodiments for controlling condensate in an engine heat exchanger are disclosed. In one example, a method for an engine comprises increasing exhaust gas recirculation (EGR) flow responsive to condensation in an EGR cooler. In this way, condensate in the EGR cooler may be controlled via modulation of EGR flow.

Abstract: A heat exchanger (28) has a first inlet (29) and a first outlet (30), which are fluidically connected with one another via a first path (31) carrying for a first medium to be cooled. A second inlet (32) and a second outlet (33) are fluidically connected with one another via a second path (34) carrying a second medium. A third inlet (35) and a third outlet (36) are fluidically connected with one another via a third path (37) carrying a third medium. The first path (31) is coupled with the second path (34) and with the third path (37) in a heat-transferring manner and in such as way that the media are separated. The heat-transferring coupling between the first path and the second path takes place upstream of the heat-transferring coupling between the first path and the third path relative to the direction of flow of the first medium.

Abstract: An exhaust gas cooling module for an internal combustion engine includes an exhaust gas recirculation valve comprising an exhaust gas recirculation valve housing having an inlet, an exhaust gas heat exchanger, an exhaust gas non-return valve comprising an exhaust gas non-return valve housing, and two exhaust gas channels. The two exhaust gas channels are arranged in the exhaust gas cooling module so as to separately extend from the inlet of the exhaust gas recirculation valve housing to the exhaust gas non-return valve housing via the exhaust gas heat exchanger.

Abstract: Embodiments for controlling an exhaust back-pressure valve are provided. In one example, a method for operating an engine comprises closing an exhaust back-pressure valve in response to a component temperature, adjusting intake and/or exhaust valve operation in response to closing the exhaust back-pressure valve to reduce cylinder internal exhaust gas recirculation (EGR), and while the exhaust back-pressure valve is closing, indicating degradation of an exhaust back-pressure system if a designated engine operating parameter remains constant. In this way, degradation of the exhaust back-pressure system may be diagnosed while maintaining combustion stability.

Abstract: A charge air cooler, a system to control condensation within a plurality of cooling tubes of a charge air cooler, and a method are disclosed. The system includes an air flow control arrangement configured to selectively ensure a flow rate of charge air through each individual cooling tube is either essentially zero or above a predetermined minimum flow rate in accordance with predetermined operating conditions of the engine.

Abstract: A heat exchanger associated with an exhaust gas recirculation system cools the exhaust gasses before directing them to an internal combustion engine. The heat exchanger can include a tube core having a plurality of exhaust gas tubes that can extend along a longitudinal axis. The tube core can also include a plurality of coolant channels disposed between and spacing apart the plurality of exhaust gas tubes. A coolant inlet line is disposed about at least a portion of the tube core to direct coolant inwardly toward the coolant channels. At least a portion of the coolant can converge approximately at the longitudinal axis line.

Abstract: A dual EGR loop exhaust gas recirculation (EGR) system for an internal combustion engine. The engine has both a dedicated EGR loop and a low pressure EGR loop. This means that one or more engine cylinders is operable as a dedicated EGR cylinder, such that all of its exhaust is recirculated via the dedicated EGR loop. The other cylinders are operable as main cylinders having two intake ports, such that each main cylinder may receive a mixture of fresh air and dedicated EGR through one intake port and a mixture of fresh air and low pressure EGR through the other intake port. A control unit controls this dual loop EGR system to either provide EGR only from the dedicated EGR loop or to also provide additional EGR from the low pressure EGR loop.

Abstract: An engine protection system and methods for preventing intake condensation are disclosed. In a system and various of the methods, an exhaust gas recirculation (EGR) valve is positioned within an EGR passage fluidly connecting an engine exhaust stream and an engine intake stream, while a waste heat recovery (WHR) system is used to recover heat from the EGR stream. An engine control unit (ECU) is coupled to various sensors and valves to divert working fluid from the WHR system from cooling the EGR exhaust flow below a level which favors production of condensation in the engine intake system. The ECU operates to divert working fluid flow when sensors indicate characteristics of either the exhaust flow or the intake stream which might lead to heavy condensation. A three-way valve is also used to divert the working fluid to a variable expansion valve fluidly coupled to the three-way valve in response to a signal from one of the sensors to prevent damage to the system turbine.

Abstract: Systems and methods for operating an engine include controlling a temperature of recirculated exhaust gas to achieve a predetermined recirculated exhaust gas temperature. A mixture of air and temperature-controlled recirculated exhaust gas are admitted in a combustion chamber and a gaseous fuel injector delivers gaseous fuel during an intake stroke. A diesel fuel injector is activated for a first time to deliver a pre-pilot diesel quantity directly into the combustion chamber at an early stage of a compression stroke, and is activated again for a second time to deliver a pilot diesel quantity directly into the combustion chamber at a later stage of the compression stroke. A total air/fuel ratio within the combustion chamber upon completion of the second diesel fuel injector activation is lean. The air/fuel mixture is combusted during a combustion stroke, and combustion products are removed during an exhaust stroke.

Abstract: Presently disclosed are methods and systems for detecting and diagnosing a coolant leak of an engine. A method may include diagnosing a coolant leak of the engine based on a low frequency pressure response of a measured engine coolant pressure. A vehicle system is also disclosed, including an engine, a coolant system operatively connected to the engine. The coolant system includes a coolant reserve and a coolant pump between the engine and the coolant reserve. The vehicle also includes a coolant pressure sensor to measure coolant pressure, and a controller configured to measure an engine coolant pressure and diagnose a coolant leak of the coolant system based on a low frequency pressure response of the measured engine coolant pressure.

Abstract: An internal combustion engine includes at least one cylinder having a reciprocable piston, an intake system directing intake air to the at least one cylinder, and an exhaust system directing exhaust gasses from the at least one cylinder. A first fuel injector disposed to inject a first fuel into the cylinder, and a second fuel injector disposed to inject a second fuel into said cylinder. At least one intake valve of said cylinder is configured to open and close with a variable timing in accordance with a Miller thermodynamic cycle. An exhaust gas recirculation system, provides exhaust gas to said cylinder through the intake valve. An electronic controller is disposed to monitor and receive at least one input signal indicative of the operating conditions of the internal combustion engine, and adjusts at least the amount of exhaust gas recirculation.

Abstract: An exhaust gas recirculation cooler for internal combustion engines and a method of forming same. One or more cooler tubes incorporate a flexible section, comprised of one or more integrally formed convolutions, with a tube and fin architecture. The exhaust gas recirculation cooler provides thermal compensation, on a per-tube basis, with the flexible sections of the one or more cooler tubes individually displacing upon the thermal expansion of any of the respective tubes.

Abstract: A waste heat recovery (WHR) system connects a working fluid to fluid passages formed in an engine block and/or a cylinder head of an internal combustion engine, forming an engine heat exchanger. The fluid passages are formed near high temperature areas of the engine, subjecting the working fluid to sufficient heat energy to vaporize the working fluid while the working fluid advantageously cools the engine block and/or cylinder head, improving fuel efficiency. The location of the engine heat exchanger downstream from an EGR boiler and upstream from an exhaust heat exchanger provides an optimal position of the engine heat exchanger with respect to the thermodynamic cycle of the WHR system, giving priority to cooling of EGR gas. The configuration of valves in the WHR system provides the ability to select a plurality of parallel flow paths for optimal operation.

Abstract: Methods are provided for controlling a turbocharged engine having an additional throttle located between an intake manifold of the engine and an outlet of a compressor. In one example approach a method comprises, during a cold start condition, diverting a portion of compressed air from downstream a compressor to a heat exchanger, and heating vehicle components with the heat exchanger.

Abstract: An exhaust gas recirculation (EGR) cooler for cooling exhaust gas includes at least one channel configured to allow the exhaust gas to flow through it, and a casing defining a cooling chamber around the at least one channel. The cooling chamber is configured to enable heat transfer between the exhaust gas and the coolant. The at least one channel has an interior surface and an exterior surface made of a first metal and a second metal, respectively, and configured to be in contact with the exhaust gas and the coolant, respectively. The second metal has a higher thermal conductivity than the first metal. The casing includes a coolant inlet and a coolant outlet configured to enable the coolant to enter and exit the cooling chamber, and an exhaust gas inlet and an exhaust gas outlet configured to enable the exhaust gas to enter and exit the at least one channel.

Abstract: A device is provided for compressor and charge air cooler protection in an internal combustion engine, such as a Diesel engine. The engine having an intake manifold and an exhaust manifold, first and second EGR routes, a charge air cooler, a turbocharger having a compressor and a turbine. A regulator is also provided for regulating the flow rate of exhaust gas and the splitting of exhaust gas between the first and second EGR route. A temperature sensor is also provided for sensing output temperature of gas at the outlet of said compressor. A method and computer readable medium embodying a computer program product are also provided that have a first phase of monitoring a parameter representative of the gas temperature at the output of the compressor and a second phase in which an activity involving engine components operation is performed. The activity is performed using temperature information determined in the monitoring phase.

Abstract: Embodiments for a charge air cooler are provided. In one example, an engine method comprises increasing intake air flow velocity through a charge air cooler and coordinately adjusting a position of one or more of an intake manifold throttle and a turbocharger wastegate in response to the increased intake air flow velocity to maintain torque. In this way, intake air flow velocity may be increased while maintaining desired torque.

Abstract: An attaching system of an exhaust gas recirculation valve includes: an attachment unit 2 to be communicated with an exhaust gas circulation passage of an internal combustion engine; and an exhaust gas recirculation valve 1 that is fitted to the attachment unit and that has an exhaust gas passage to be communicated with the exhaust gas circulation passage, wherein the exhaust gas recirculation valve has a water-cooled passage 12 to be communicated with a water-cooled passage 15 for cooling the exhaust gas passage provided with the attachment unit, when fitted to the attachment unit.

Abstract: Methods and systems are provided for estimating water storage in a charge air cooler (CAC). In one example, an amount of water accumulating in the CAC may be based on an output of an oxygen sensor positioned downstream of the CAC and ambient humidity. Further, engine actuators may be adjusted to purge condensate from the CAC and/or reduce condensate formation based on the amount of water inside the CAC.

Abstract: Various systems and methods are described for an exhaust gas recirculation (EGR) system coupled to an engine in a vehicle. One example method comprises, controlling an amount of EGR according to a minimum of a first EGR amount corresponding to a temperature of a first location and a second EGR amount corresponding to a condensate formation of a second location.

Abstract: An EGR gas cooling device for hybrid vehicle provided in an EGR system for refluxing a part of exhaust gas of an engine as EGR gas to an intake passage and configured to cool the EGR gas in a hybrid vehicle including the engine and a motor as travel drive sources of the vehicle includes an EGR cooler for cooling the EGR gas using a refrigerant flowing in a strong electric cooling circuit for cooling the motor.

Abstract: The engine boosting system includes an engine having an intake manifold, exhaust manifold and exhaust gas recirculation loop fluidly connected therebetween. A boost circuit including a storage vessel is in fluid communication with the intake manifold and with the exhaust manifold. A throttle is located downstream of the exhaust manifold, the exhaust gas recirculation loop, and the boost circuit. A connection between the boost circuit and the intake manifold is independent of a connection between the exhaust gas recirculation loop and the intake manifold.

Abstract: A sensor for detecting the oxygen content in the intake tract of an internal combustion engine includes: a sensor element having a measurement electrode; a metal cap that surrounds the sensor element; a heat dissipation element that connects the sensor element and the metal cap; and a bracket for the sensor element. The bracket is in the form of a plastic housing configured to accommodate evaluation electronics for the sensor element.

Abstract: An internal combustion engine system basically has an internal combustion engine, a reforming fuel injection device and a reformer. The internal combustion engine has an exhaust circulation path that is connected to an exhaust path and an intake path communicating with a combustion chamber. The reforming fuel injection device injects a reforming fuel into an exhaust gas flowing through the exhaust circulation path. The reformer has a reforming catalyst for generating a hydrogen-containing gas using the reforming fuel. The internal combustion engine system has a reforming catalyst regeneration device for causing an oxygen-containing gas to flow through the exhaust circulation path and thereby regenerate the reforming catalyst at a predetermined timing for regenerating the reforming catalyst.

Abstract: A method includes operating a spark ignition engine and flowing low pressure exhaust gas recirculation (EGR) from an exhaust to an inlet of the spark ignition engine. The method includes interpreting a parameter affecting an operation of the spark ignition engine, and determining a knock index value in response to the parameter. The method further includes reducing a likelihood of engine knock in response to the knock index value exceeding a knock threshold value.

Abstract: Methods and systems are provided for determining degradation of an EGR cooler based on differential pressure across the EGR cooler during EGR flow. In one example, the differential pressure across the EGR cooler may be based on differential pressure across an EGR valve and a pressure downstream from the EGR valve with and without EGR flow. The pressure downstream from the EGR valve may be a compressor inlet pressure or an intake manifold pressure in a low pressure EGR system or high pressure EGR system, respectively.

Abstract: Embodiments for heating a vehicle cabin are disclosed. In one example, a method for an engine comprises pumping coolant from a coolant reservoir to an exhaust component and then to a heater core, the coolant heated by the exhaust component, and during engine warm-up conditions, adjusting a flow rate of coolant into a heater core to maximize heat transfer to a vehicle cabin.

Abstract: An engine system for a machine is disclosed. The engine system may have an intake manifold configured to direct air into a donor cylinder and a non-donor cylinder of an engine. The engine system may also have a first exhaust manifold configured to direct exhaust from the non-donor cylinder to the atmosphere. The engine system may also have a second exhaust manifold configured to receive exhaust from the donor cylinder. The engine system may further have a control valve configured to selectively direct a first amount of exhaust from the second exhaust manifold to the intake manifold. In addition, the engine system may have an orifice configured to allow a second amount of exhaust to flow from the second exhaust manifold to the first exhaust manifold.

Abstract: Systems and method for extracting energy from a gas are disclosed herein. In particular, systems and methods for implementing a series of thermodynamic transformations by means of which it is possible to extract useful work from a gas carrying thermal energy due its thermodynamic state are disclosed. An example system for extracting energy from a cycle gas can include an expander for expanding the cycle gas, a heat exchanger in fluid connection with the expander for cooling the expanded cycle gas while maintaining the expanded cycle gas at an approximately constant pressure, and a compressor in fluid connection with the heat exchanger for compressing the cooled cycle gas.

Abstract: An exhaust gas recirculation (EGR) device includes an EGR passage, a cooling medium circuit, an EGR cooler, and an intercooler. A part of exhaust gas flowing through an exhaust passage of an internal combustion engine is recirculated as EGR gas into an intake passage of the engine through the EGR passage. A cooling medium flows through the cooling medium circuit. The EGR cooler performs a heat exchange between EGR gas flowing through the EGR passage and the cooling medium flowing through the cooling medium circuit so as to cool EGR gas. The intercooler is disposed at the intake passage on a downstream side of a merging part between the intake passage and the EGR passage in a flow direction of intake air, and performs a heat exchange between intake air including EGR gas and flowing through the intake passage, and the cooling medium flowing through the cooling medium circuit so as to cool intake air.

Abstract: A connecting passage is formed inside a cylinder head, which extends rearward from an exhaust passage and connects to the exhaust passage. The connecting passage branches inside the cylinder head into two branch passages, which open at a rear end face of the cylinder head, respectively. An opening portion, one of opening portions of the branch passages, connects to an EGR cooler, and another opening portion, the other of opening portions of the branch passages, connects to a bypass pipe. Accordingly, the exhaust gas recirculation device of an engine which can restrain the device from being improperly large sized, providing the EGR cooler and the bypass pipe, can be provided.

Abstract: Methods and systems are provided for accurately learning the zero point of an intake gas oxygen sensor during selected idling conditions. The learned zero point is used to infer EGR flow and accordingly adjust EGR valve control. In addition, EGR valve leakage is diagnosed based on the zero point learned during an idle adaptation relative to a zero point learned during a DFSO adaptation.

Abstract: The invention relates to a fluid circulation valve, notably for a motor vehicle, comprising a body (2) and a shutoff element (3) able, by rotation of said element (3) with respect to said body (2), to occupy various angular positions, said body (2) having a first (6), a second (7), a third (21) and a fourth (22) inlet/outlet. Said valve is configured so that it: —in a first of said angular positions allows fluid to circulate from the first (6) to the second (7) inlet/outlet, —in a second of said angular positions allows fluid to circulate from the first (6) to the third (21) inlet/outlet, and from the fourth (22) to the second inlet/outlet (7), —in a third of said angular positions allows fluid to circulate from the first (6) to the fourth inlet/outlet (22) and from the third (21) to the second (7) inlet/outlet.

Abstract: Methods and systems are provided for accurately learning the zero point of an intake gas oxygen sensor during selected engine no-fueling conditions. The learned zero point is used to infer EGR flow and accordingly adjust EGR valve control. In addition, EGR valve leakage is diagnosed based on the zero point learned during a DFSO adaptation relative to a zero point learned during an idle adaptation.

Abstract: In an exemplary embodiment, an internal combustion engine includes an oxidation catalyst configured to receive an exhaust gas flow from the internal combustion engine, a urea injector positioned downstream of the oxidation catalyst to inject a urea flow into the exhaust gas flow and a mixer positioned downstream of the urea injector to mix the exhaust gas flow and the urea flow to form a mixed exhaust gas and urea flow. The engine also includes a particulate filter and catalytic reduction assembly positioned downstream of the mixer to receive the mixed exhaust and urea flow from the mixer to form a treated exhaust gas flow and an exhaust gas recirculation system coupled to the particulate filter to receive a portion of the treated exhaust gas flow and recirculate the portion of the exhaust gas flow to be mixed with a fresh air flow for the internal combustion engine.

Abstract: A waste heat recovery (WHR) system and method for regulating exhaust gas recirculation (EGR) cooling is described. More particularly, a Rankine cycle WHR system and method is described, including an arrangement to improve the precision of EGR cooling for engine efficiency improvement and thermal management.

Abstract: A method is provided. The method includes, during stopped engine operation, burning fuel in an engine intake heater to generate heated gas, the heated gas bypassing engine cylinders via an exhaust gas recirculation passage. The method further includes during combusting engine operation, burning fuel in the engine intake heater to generate heated gas, and flowing the heated gas through combusting engine cylinders.

Abstract: Methods and systems for metering at least one EGR valve to a position determined to pass a desired EGR flow for a given set of engine characteristics. The methods include determining the EGR valve position based on pipe flow characteristics, or determining the EGR valve position based on pipe flow characteristics when differential pressure across the EGR valve is less than a pressure threshold.

Abstract: A device for cooled recirculation of exhaust gas of an internal combustion engine charged with the aid of an exhaust gas turbocharger, the internal combustion engine having a fresh gas system and an exhaust gas system, which are connected to a two-stage exhaust gas cooler via an exhaust gas recirculation line. A device by way of which a sufficient amount of exhaust gas may be recirculated by simple means is provided. This is achieved in that exhaust gas recirculation line 8a, 8b is connected to an exhaust gas collecting line 7a, 7b of the exhaust gas system upstream from turbine 6 of exhaust gas turbocharger 5 in the direction of flow, an exhaust gas recirculation valve 9a, 9b being connected upstream from first stage 10a, 10b of the exhaust gas cooler in exhaust gas recirculation line 8a, 8b, and a nonreturn valve 11a, 11b is inserted into a continuation line 12a, 12b leading to the second stage of the exhaust gas cooler.

Abstract: An exhaust gas cooling device, which cools exhaust gas from an internal combustion engine mounted on a vehicle through heat exchange between the exhaust gas and a coolant, includes: a plurality of tubes through which the exhaust gas flows; a tubular shell which houses the plurality of tubes and is configured to allow the coolant to flow therethrough; and a header plate disposed at an end portion in the shell to prevent the coolant from flowing out of the shell. The header plate includes support holes in which end portions of the plurality of the tubes are fitted and supported, and each of axial end faces of the plurality of tubes is located in the corresponding support hole at a position between both ends of the header plate in a thickness direction of the header plate.

Abstract: Methods and systems for controlling the conditions of a coolant for the cooler of an exhaust gas recirculation system are disclosed. The system determines coolant pressure at predetermined location of the cooler. The system also senses the actual temperature of the coolant at a predetermined location of the cooler. The system also determines a coolant boiling temperature at the determined coolant pressure. Using the determined coolant pressure, the system may control engine operation so as to prevent coolant from reaching boiling in the cooler. An engine derate power factor may be determined to control the amount of fuel delivered to the engine, such as reducing the amount of fuel delivered through the fuel injectors. The amount of delivered fuel may be derated until an adjusted coolant temperature falls a predetermined amount below the coolant boiling temperature.

Abstract: The invention relates to an exhaust gas recirculation cooling element (1) comprising a heat exchanger (2) having several heat exchange units (11, 12, 13) that are introduced between the inflow region (3) and the outflow region (7) of the exhaust gas (AG). Said units comprise cooling tubes with cooling ribs. The heat exchanger (2) is surrounded by a housing (16), the lateral walls thereof (19) being arranged at a distance in relation to the perforated lateral walls (10). Guide channels (28) are arranged between the closed lateral walls (9) of the heat exchanger (2) and the adjacent lateral walls (20) of the housing (16), said guide channels extending in a diagonal manner and being provided to direct the coolant (KM) from a coolant inlet to the coolant outflow through the individual heat exchange units (11, 12, 13).

Abstract: An exhaust gas recirculation (EGR) cooler for cooling exhaust gas via a coolant includes at least one channel having an inlet and an outlet, and a casing defining a cooling chamber for carrying the coolant around the at least one channel. The exhaust gas is flowable through the at least one channel from the inlet to the outlet. At least a portion of the at least one channel is variable between a fully compressed position and an uncompressed position. The casing includes a coolant inlet and a coolant outlet through which the coolant enters and exits the cooling chamber. The casing also includes an exhaust gas inlet from which the exhaust gas enters the at least one channel, and an exhaust gas outlet into which the exhaust gas exits the at least one channel.

Abstract: An EGR cooler mount comprising an inlet port, an outlet port positioned downstream of the inlet port, and a leak off passage. The inlet port is configured to receive fuel, and the outlet port is configured to distribute the fuel to a fuel tank. The leak passage is positioned fluidly between the inlet port and the outlet port, and is positioned in the EGR cooler mount.

Abstract: An EGR cooler and an EGR cooler device includes a pre-cooler which is located at a central region at which a cooling water chamber of an EGR cooler housing, in which cooling water circulates, is divided into two spaces, and in which hot exhaust gas introduced from an exhaust system is discharged as primary-cooled exhaust gas via heat-exchange with the cooling water. Therefore, it may be possible to reduce costs by a decrease in number of EGR tubes via optimal primary cooling performance for the exhaust gas in the pre-cooler and particularly to relieve damage by a thermal load generated due to the hot exhaust gas by fully surrounding an inlet and an outlet of the pre-cooler with the circulating cooling water.

Abstract: An exhaust gas recirculation cooler for an internal combustion engine is provided. The exhaust gas recirculation cooler includes an external casing with an inlet and an outlet for an exhaust gas flow. A first tube bundle and a second tube bundle, each with an inlet and an outlet for a coolant, are located inside the external casing so that the exhaust gas flow flows through the first tube bundle and the second tube bundle in series. A bypass passage conveys the exhaust gas flow from downstream the first tube bundle to the outlet of the external casing bypassing the second tube bundle. The bypass passage is located inside the external casing between the first tube bundle and the second tube bundle.