DE102019206104A1 - Supercharged internal combustion engine with exhaust gas recirculation and method for operating such an internal combustion engine - Google Patents

Abstract

The invention relates to a supercharged internal combustion engine (1) with a liquid cooling system (10) comprising a coolant circuit (10a) that carries a coolant, an intake system (2) for supplying charge air, - an exhaust gas discharge system (3) for discharging exhaust gas, - At least one compressor (4) which is arranged to compress the charge air in the intake system (2) and comprises at least one impeller mounted in a compressor housing on a rotatable shaft and equipped with rotor blades, - an exhaust gas recirculation system (6) including a return line (6a) which upstream of the at least one compressor impeller with the formation of a first node (6 ') opens into the intake system (2), and - a heat exchanger (7) which is arranged upstream of the first node (6') in the intake system (2) and enters the coolant circuit ( 10a) is incorporated and a heat transfer between the charge air and the coolant is used. It should be an internal combustion engine of the type mentioned This is achieved by an internal combustion engine, which is characterized in that an electrically operated heating device (11) is arranged in the coolant circuit (10a) upstream of the heat exchanger (7), with which the formation of condensate in the intake system (2) can be counteracted.

Description

• - einer Flüssigkeitskühlung umfassend einen - ein Kühlmittel führenden - Kühlmittelkreislauf,
• - einem Ansaugsystem zum Zuführen von Ladeluft,
• - einem Abgasabführsystem zum Abführen von Abgas,
• - mindestens einem zur Kompression der Ladeluft im Ansaugsystem angeordneten Verdichter, der mindestens ein in einem Verdichtergehäuse auf einer drehbaren Welle gelagertes und mit Laufschaufeln ausgestattetes Laufrad umfasst,
• - einer Abgasrückführung umfassend eine Rückführleitung, die stromaufwärts des mindestens einen Verdichterlaufrades unter Ausbildung eines ersten Knotenpunktes in das Ansaugsystem mündet, und
• - einem Wärmetauscher, der stromaufwärts des ersten Knotenpunktes im Ansaugsystem angeordnet und in den Kühlmittelkreislauf eingebunden ist und einem Wärmeübergang zwischen der Ladeluft und dem Kühlmittel dient.

The invention relates to a supercharged internal combustion engine

• - a liquid cooling system comprising a - a coolant carrying - coolant circuit,
• - an intake system for supplying charge air,
• - an exhaust gas removal system for removing exhaust gas,
• - At least one compressor arranged for compressing the charge air in the intake system, comprising at least one impeller which is mounted in a compressor housing on a rotatable shaft and equipped with rotor blades,
• an exhaust gas recirculation system comprising a recirculation line which opens into the intake system upstream of the at least one compressor impeller, forming a first junction, and
• - A heat exchanger, which is arranged upstream of the first node in the intake system and integrated into the coolant circuit and serves to transfer heat between the charge air and the coolant.

The invention also relates to a method for operating such an internal combustion engine.

An internal combustion engine of the type mentioned is used as a motor vehicle drive. In the context of the present invention, the term internal combustion engine relates to diesel engines and Otto engines, but also to hybrid internal combustion engines, i.e. Internal combustion engines that are operated with a hybrid internal combustion process, as well as hybrid drives that, in addition to the internal combustion engine, comprise at least one further torque source for driving a motor vehicle, for example an electric machine that can be drive-connected or drive-connected to the internal combustion engine, which instead of the internal combustion engine or in addition to Internal combustion engine outputs power.

Modern internal combustion engines are usually subjected to higher thermal loads and therefore also place increased demands on cooling, especially if the cylinder head is equipped with an integrated exhaust manifold and / or the internal combustion engine is a supercharged internal combustion engine.

If the internal combustion engine has liquid cooling, a plurality of coolant ducts are regularly formed in the cylinder head and / or cylinder block, or at least one coolant jacket that guides the coolant through the cylinder head or cylinder block.

In the development of internal combustion engines, constant efforts are made to minimize fuel consumption. In addition, a reduction in pollutant emissions is sought in order to be able to comply with future limit values for pollutant emissions.

Internal combustion engines are increasingly being equipped with a supercharger, the supercharging primarily being a process for increasing performance in which the charge air required for the engine combustion process is compressed, so that a larger charge air mass can be supplied to each cylinder per work cycle. This allows the fuel mass and thus the mean pressure to be increased.

Supercharging is a suitable means of increasing the output of an internal combustion engine with unchanged cubic capacity or reducing the cubic capacity with the same output. In any case, the charging leads to an increase in the installation space performance and a more favorable power mass. If the displacement is reduced, the load spectrum can be shifted towards higher loads, at which the specific fuel consumption is lower. By means of supercharging in combination with a suitable gear design, so-called downspeeding can also be achieved, in which a lower specific fuel consumption can also be achieved.

Supercharging thus supports the constant effort in the development of internal combustion engines to minimize fuel consumption, i. to improve the efficiency of the internal combustion engine.

Often an exhaust gas turbocharger is used for charging, in which a compressor and a turbine are arranged on the same shaft. The hot exhaust gas flow is fed to the turbine and relaxes with the release of energy in the turbine, causing the shaft to rotate. The energy released by the exhaust gas flow to the turbine and finally to the shaft is used to drive the compressor, which is also located on the shaft. The compressor conveys and compresses the charge air supplied to it, as a result of which the cylinders are charged.

A charge air cooler is advantageously provided downstream of the compressor in the intake system, with which the compressed charge air is cooled before it enters the at least one cylinder. The cooler lowers the temperature and thus increases the density of the charge air, so that the cooler also closes a better filling of the cylinder, ie to a larger air mass contributes. There is a compression by cooling.

The advantage of an exhaust gas turbocharger compared to a - mechanical - charger is that an exhaust gas turbocharger uses the exhaust gas energy of the hot exhaust gases, while a mechanical charger draws the energy required for its drive directly or indirectly from the internal combustion engine and thus, at least as long as the drive energy does not originates from energy recovery, adversely affects the efficiency, ie diminishes. As a rule, a mechanical connection, such as a traction drive, is required for power transmission between the charger and the internal combustion engine.

The advantage of a mechanical supercharger compared to an exhaust gas turbocharger is that the mechanical supercharger can generally generate and provide the required boost pressure regardless of the current operating state of the internal combustion engine, in particular even at low speeds of the crankshaft. The advantage of a charger over an exhaust gas turbocharger is that the charger can always generate and provide the requested boost pressure, regardless of the operating state of the internal combustion engine. This applies in particular to a charger that can be driven electrically by means of an electric machine and is therefore independent of the speed of the crankshaft.

According to the prior art, it is difficult to increase the performance by means of exhaust gas turbocharging in all speed ranges. A greater drop in torque is observed when the speed falls below a certain level. This torque drop becomes understandable if it is taken into account that the boost pressure ratio depends on the turbine pressure ratio. If the engine speed is reduced, this leads to a smaller exhaust gas mass flow and thus to a smaller turbine pressure ratio, which is why the boost pressure ratio also decreases towards lower speeds. This is equivalent to a torque drop.

The supercharged internal combustion engine, which is the subject of the present invention, has at least one compressor for the purpose of supercharging, which can be a mechanical charger, an electric charger or the compressor of an exhaust gas turbocharger.

Problems can arise upstream of the compressor, especially if the internal combustion engine is equipped with exhaust gas recirculation, in which the exhaust gas is introduced into the intake system upstream of the compressor. This is because condensate can form. There are several scenarios to consider.

On the one hand, condensate can form when recirculated hot exhaust gas meets cool fresh air and is mixed. The exhaust gas cools down, whereas the temperature of the fresh air is raised. The temperature of the mixture of fresh air and recirculated exhaust gas, i.e. the charge air temperature is below the exhaust gas temperature of the recirculated exhaust gas. As part of the cooling of the exhaust gas, liquids previously contained in gaseous form in the exhaust gas, in particular water, can condense out if the temperature of a component of the gaseous charge air flow falls below the dew temperature.

Condensation forms in the free flow of charge air, with impurities in the charge air frequently forming the starting point for the formation of condensate droplets.

On the other hand, condensate can form when recirculated hot exhaust gas or the charge air hits the inner wall of the intake system or the inner wall of the compressor housing, since the wall temperature is usually below the dew temperature of the relevant gaseous components.

The problem described above is exacerbated as the recirculation rate increases, since the proportions of the individual exhaust gas components in the charge air inevitably increase with the increase in the amount of recirculated exhaust gas, in particular the proportion of the water contained in the exhaust gas. According to the prior art, the amount of exhaust gas recirculated by means of the low-pressure EGR is therefore often limited in order to prevent or reduce the condensation. The necessary limitation of the low-pressure EGR on the one hand and the high exhaust gas recirculation rates required for a significant reduction in nitrogen oxide emissions on the other hand lead to different objectives when measuring the amount of recirculated exhaust gas. The legal requirements for the reduction of nitrogen oxide emissions illustrate the high relevance of this problem in practice.

In addition, the problem of condensate formation becomes more relevant as the ambient temperature falls. The lower the ambient temperature, the higher the probability of condensation and the more condensation will be formed. This is particularly important with regard to the test cycles proposed by the legislator under real conditions.

The effects described above in connection with the recirculation of hot exhaust gas also apply in an analogous manner to the venting flow, which is usually taken from the crankcase and introduced into the intake system upstream of the compressor.

Condensate and condensate droplets are undesirable and lead to increased noise emissions in the intake system, possibly damaging the blades of the at least one compressor impeller. The latter is associated with a reduction in the efficiency of the compressor.

The US 8,297,922 B1 describes a hood that is intended to protect the compressor impeller from damage and deposits. The hood represents an additional weight that rotates with the rotating impeller of the compressor, with correspondingly high forces acting on the compressor shaft and in the bearing. Since the heavy hood must also be accelerated and decelerated with the rotating impeller of the compressor, the response behavior of the compressor deteriorates in a not inconsiderable way.

The impeller of the compressor can also be coated or surface-treated, in particular hardened.

Alternatively, according to the prior art, the compressor is equipped with a heating device with which the temperature of the inner wall of the compressor housing can be increased. The formation of condensation on the inner wall of the intake system or on the inner wall of the compressor housing can be avoided or reduced in this way. This is a complex and cost-intensive concept.

Another concept from the prior art provides for a heat exchanger to be arranged upstream of the compressor in the intake system. The heat exchanger is integrated into the coolant circuit of the internal combustion engine so that heat can be introduced into the cooler charge air by means of heated coolant. The disadvantage of this concept is that it is not possible to heat the charge air using coolant after a cold start of the internal combustion engine, since after a cold start the coolant itself usually does not have the higher temperature required to heat the charge air, especially not at low ambient temperatures.

Against this background, it is an object of the present invention to provide a supercharged internal combustion engine according to the preamble of claim 1, with which the disadvantages known from the prior art are overcome and with which condensate formation in the intake system can be counteracted.

Another sub-object of the present invention is to provide a method for operating such an internal combustion engine.

• - einer Flüssigkeitskühlung umfassend einen - ein Kühlmittel führenden - Kühlmittelkreislauf,
• - einem Ansaugsystem zum Zuführen von Ladeluft,
• - einem Abgasabführsystem zum Abführen von Abgas,
• - mindestens einem zur Kompression der Ladeluft im Ansaugsystem angeordneten Verdichter, der mindestens ein in einem Verdichtergehäuse auf einer drehbaren Welle gelagertes und mit Laufschaufeln ausgestattetes Laufrad umfasst,
• - einer Abgasrückführung umfassend eine Rückführleitung, die stromaufwärts des mindestens einen Verdichterlaufrades unter Ausbildung eines ersten Knotenpunktes in das Ansaugsystem mündet, und
• - einem Wärmetauscher, der stromaufwärts des ersten Knotenpunktes im Ansaugsystem angeordnet und in den Kühlmittelkreislauf eingebunden ist und einem Wärmeübergang zwischen der Ladeluft und dem Kühlmittel dient,

die dadurch gekennzeichnet ist, dass

• - stromaufwärts des Wärmetauschers eine elektrisch betriebene Heizeinrichtung im Kühlmittelkreislauf angeordnet ist.

The first sub-task is also solved by a supercharged internal combustion engine

• - a liquid cooling system comprising a - a coolant carrying - coolant circuit,
• - an intake system for supplying charge air,
• - an exhaust gas removal system for removing exhaust gas,
• - At least one compressor arranged for compressing the charge air in the intake system, comprising at least one impeller which is mounted in a compressor housing on a rotatable shaft and equipped with rotor blades,
• an exhaust gas recirculation system comprising a recirculation line which opens into the intake system upstream of the at least one compressor impeller, forming a first junction, and
• - a heat exchanger, which is arranged upstream of the first node in the intake system and integrated into the coolant circuit and serves to transfer heat between the charge air and the coolant,

which is characterized in that

• - An electrically operated heating device is arranged in the coolant circuit upstream of the heat exchanger.

According to the invention, the liquid cooling of the internal combustion engine is equipped with an electrically operated heating device which is arranged upstream of the heat exchanger in the coolant circuit and with which - if necessary - the temperature of the coolant can be increased before it enters the heat exchanger, for example when the internal combustion engine is cold started or the ambient temperature is low . The coolant temperature can be adjusted by means of the heating device via the charge air temperature, i. the temperature of the ambient air can also be raised, so that using the heated coolant, heat can be introduced into the charge air as it flows through the heat exchanger.

A formation of condensate on the inner wall of the intake system or the compressor housing as well as a formation of condensate in the free charge air flow can be avoided or reduced in this way.

By preventing the formation of condensate in the intake system and in the inlet area of the compressor, there is no increased noise emission due to condensate droplets. The risk of damage to the impeller blades of the at least one compressor is eliminated.

With the internal combustion engine according to the invention, the first object on which the invention is based is achieved, namely an internal combustion engine according to the preamble of claim 1 with which the disadvantages known from the prior art are overcome and with which the formation of condensation in the intake system can be counteracted.

In the context of the present invention, low ambient temperatures relate in particular to temperatures below freezing point, for example minus 7 ° C.

An electrical heating device can be activated and used at any time to heat the coolant by supplying heat. This electrical heating device can be supplied with energy independently of the operating state of the internal combustion engine, for example by means of the on-board battery of a vehicle.

Further advantageous embodiments of the supercharged internal combustion engine are discussed in connection with the subclaims.

Embodiments of the supercharged internal combustion engine are advantageous in which the return line branches off from the exhaust gas discharge system with the formation of a second junction.

In the present case, the exhaust gas recirculation can be, for example, a high-pressure EGR that takes exhaust gas from the exhaust gas removal system upstream of the turbine of an exhaust gas turbocharger and introduces it into the intake system, or a low-pressure EGR that recirculates exhaust gas to the inlet side that has already flowed through the turbine. A low-pressure EGR comprises a return line, which branches off from the exhaust gas removal system downstream of the turbine and opens into the intake system upstream of the compressor.

The main advantage of low-pressure EGR compared to high-pressure EGR is that the exhaust gas flow introduced into the turbine is not reduced by the amount of exhaust gas that is recirculated in the event of exhaust gas recirculation. The entire exhaust gas flow is always available at the turbine to generate a sufficiently high boost pressure.

The exhaust gas, which is returned to the inlet side by means of low-pressure EGR and, in individual cases, cooled, is mixed with fresh air upstream of the compressor. The mixture of fresh air and recirculated exhaust gas produced in this way forms the charge air, which is fed to the compressor and compressed.

It is harmless here that, as part of the low-pressure EGR, exhaust gas is passed through the compressor, since exhaust gas is preferably used which has been subjected to exhaust gas aftertreatment, in particular in a particle filter, downstream of the turbine. Deposits in the compressor which change the geometry of the compressor, in particular the flow cross-sections and in this way impair the efficiency of the compressor, are therefore not to be feared.

According to the invention, condensation can be avoided or reduced. In this respect, it is not necessary to limit the amount of exhaust gas recirculated by means of low-pressure EGR, so that high recirculation rates can be achieved by means of low-pressure EGR in order to significantly reduce nitrogen oxide emissions.

Nonetheless, in addition to the low-pressure EGR, a high-pressure EGR can also be used, in which exhaust gas is removed from the exhaust gas discharge system upstream of the turbine of an exhaust gas turbocharger and introduced into the intake system downstream or upstream of the compressor.

Embodiments of the charged internal combustion engine are advantageous in which no consumer is arranged in the coolant circuit between the heat exchanger and the electrically operated heating device. A consumer in the present sense is a unit that requires a heat input to maintain its function, for example a vehicle interior heater or an oil heater. In this respect, a shut-off element, for example a flap or a valve, is not a consumer.

A consumer would extract heat from the coolant before it enters the heat exchanger and in this way reduce the heat transfer from the coolant to the charge air.

Embodiments of the supercharged internal combustion engine are advantageous in which an air cleaning device is arranged upstream of the first node in the intake system. An air cleaning device filters particles and foreign bodies from the charge air flow, whereby not only contamination but also damage to the downstream intake system, the at least one compressor and the internal combustion engine can be prevented.

In this context, embodiments of the supercharged internal combustion engine are advantageous in which the air cleaning device and the heat exchanger are designed as a common, integrative component. Both the air cleaning device and the heat exchanger benefit from the largest possible area or surface. With the air cleaning device, a large filter surface ensures a sufficiently large charge air flow with a low pressure loss. In the case of a heat exchanger, the amount of heat that can be transferred increases the larger the heat transfer area.

An integrative component comprising the air cleaning device and the heat exchanger can be made available as a preassembled assembly and contributes to more effective packaging in the engine compartment.

Embodiments of the supercharged internal combustion engine are advantageous in which the at least one compressor has an inlet area which runs coaxially to the shaft of the compressor and is designed so that the charge air flows to the compressor essentially axially.

In the case of an axial flow towards the compressor, there is often no need to deflect or change direction of the charge air flow in the intake system upstream of the at least one compressor impeller, which avoids unnecessary pressure losses in the charge air flow due to flow deflection and increases the pressure of the charge air at the inlet to the compressor of the exhaust gas turbocharger. The lack of a change in direction also reduces the contact of the exhaust gas or the charge air with the inner wall of the intake system or with the inner wall of the compressor housing and thus reduces the heat transfer and the formation of condensate.

Embodiments of the supercharged internal combustion engine are advantageous in which the at least one compressor arranged in the intake system belongs to an exhaust gas turbocharger which comprises a turbine arranged in the exhaust gas discharge system and a compressor arranged in the intake system.

A turbine with variable turbine geometry allows further adaptation to the respective operating point of the internal combustion engine by adjusting the turbine geometry or the effective turbine cross-section, whereby to a certain extent a speed-dependent or load-dependent regulation of the turbine geometry can take place.

The torque characteristics of a supercharged internal combustion engine can be improved by using several turbochargers. In addition to an exhaust gas turbocharger, a mechanical or electrical charger can in principle also be provided. The advantages are those already mentioned above.

Embodiments of the supercharged internal combustion engine are advantageous in which the return line branches off from the exhaust gas discharge system downstream of the turbine of the exhaust gas turbocharger, forming a second junction. The advantages are those already mentioned in connection with the description of the low-pressure EGR.

In this context, embodiments of the supercharged internal combustion engine are advantageous in which a first shut-off element is arranged in the exhaust gas discharge system downstream of the second junction.

The return line branches off from the exhaust gas discharge system between the turbine and the first shut-off element. The first shut-off element can be used to increase the exhaust gas pressure upstream in the exhaust gas discharge system, and thus contribute to or be used to increase the pressure gradient between the exhaust gas discharge system and the intake system. This is particularly advantageous in the case of high return rates, which require a greater pressure gradient.

Embodiments of the charged internal combustion engine are also advantageous in which a second shut-off element is arranged in the intake system upstream of the first node.

The second shut-off element serves to reduce the pressure in the intake system on the inlet side and can thus - like the first shut-off element - contribute to an increase in the pressure gradient between the exhaust gas discharge system and the intake system.

Embodiments of the supercharged internal combustion engine are advantageous in which the first and / or second shut-off element is a pivotable flap.

Embodiments of the supercharged internal combustion engine in which an EGR cooler is arranged in the return line can be advantageous. The cooling of the recirculated exhaust gas is particularly recommended in the case of large amounts of exhaust gas to be recirculated or high recirculation rates.

Embodiments of the supercharged internal combustion engine are advantageous in which an EGR valve is arranged in the return line.

An EGR valve is used to adjust the amount of recirculated exhaust gas. Embodiments in which the EGR valve is arranged at the first node are particularly advantageous. Embodiments are particularly advantageous which are characterized in that the EGR valve is a combined valve with which both the amount of recirculated exhaust gas and the amount of fresh air can be adjusted.

The second sub-task on which the invention is based, namely to show a method for operating a supercharged internal combustion engine of the type described above, is achieved by a method which is characterized in that the electrically operated heating device is activated in order to increase the temperature of the coolant before it enters the To increase the heat exchanger and to introduce heat into the charge air using the heated coolant and to increase the charge air temperature in this way.

What has already been said for the internal combustion engine according to the invention also applies to the method according to the invention, which is why reference is generally made at this point to the statements made above with regard to the charged internal combustion engine. The various internal combustion engines sometimes require different process variants.

Process variants are advantageous in which the electrically operated heating device is activated if condensation is expected in the intake system.

Method variants in which the electrically operated heating device is activated after a cold start of the internal combustion engine are advantageous.

Method variants in which the electrically operated heating device is activated if the ambient temperature is below a predeterminable limit temperature are advantageous.

• 1 schematisch eine erste Ausführungsform der Brennkraftmaschine.

In the following the invention is based on an embodiment according to 1 described in more detail. Here shows:

• 1 schematically a first embodiment of the internal combustion engine.

1 shows schematically a first embodiment of the supercharged internal combustion engine 1 that with an exhaust gas turbocharger 5 is equipped, the one in the exhaust system 3 arranged turbine 5b with variable turbine geometry and one in the intake system 2 arranged compressor 4th , 5a includes. The hot exhaust gas expands in the turbine 5b under energy delivery. The compressor 4th , 5a compresses the charge air via the intake system 2 and the intercooler provided downstream 2a is supplied to the cylinders, whereby a supercharging of the internal combustion engine 1 is achieved. It is a four-cylinder in-line engine in which the four cylinders are arranged along the longitudinal axis of the cylinder head, ie in series.

The internal combustion engine 1 has liquid cooling 10 that have a coolant circuit 10a includes which carries a coolant.

In addition, the internal combustion engine 1 with exhaust gas recirculation 6 equipped, in this case a low-pressure EGR 6 that have a return line 6a includes, which is downstream of the turbine 5b with the formation of a second node 6 " from the exhaust system 3 branches off and upstream of the compressor 5a with the formation of a first node 6 ' into the intake system 2 flows out. In the return line 6a the low pressure EGR 6 are an EGR valve 6b and an EGR cooler 6c arranged.

The exhaust gas that the turbine 5b flows through is between the turbine 5b and the second node 6 " exhaust gas aftertreatment in a particulate filter 9 subjected so that by the compressor 4th , 5a only exhaust gas that has been cleaned of soot particles flows.

Upstream of the first junction 6 ' is a second shut-off element 2 B in the intake system 2 arranged, which can be used to reduce the pressure downstream in the intake system 2 to reduce, thereby reducing the pressure gradient between the exhaust gas removal system 3 and the intake system 2 is increased. This is particularly advantageous in the case of high return rates, which require a greater pressure gradient.

Upstream of the first junction 6 ' and - in the present case - upstream of the second shut-off element 2 B an assembly is provided which has an air purification device 8th in the form of a filter and a heat exchanger 7th includes, according to 1 the heat exchanger 7th upstream of the air cleaner 8th is arranged.

The heat exchanger 7th is in the coolant circuit 10a the liquid cooling 10 integrated and serves the heat transfer between the charge air and the coolant. The temperature of the via intake system 2 through the heat exchanger 7th flowing charge air can in this way be increased, that is to say raised, using the coolant.

Liquid cooling is used for this 10 the internal combustion engine 1 with an electrically operated heating device 11 equipped that upstream of the heat exchanger 7th in the coolant circuit 10a is arranged and with which the temperature of the coolant before entering the heat exchanger 7th can be increased. By means of a heating device 11 the coolant temperature can be raised above the temperature of the charge air so that, using the heated coolant, heat is introduced into the charge air as it flows through the heat exchanger 7th can be entered.

Formation of condensation in the suction system 2 can be avoided or reduced in this way.

List of reference symbols

1

Supercharged internal combustion engine

2

Suction system

2a

Intercooler

2 B

second shut-off element

3

Exhaust gas removal system

4th

compressor

5

Exhaust gas turbocharger

5a

Compressor of the exhaust gas turbocharger

5b

Turbine of the exhaust gas turbocharger

6th

Exhaust gas recirculation

6 '

first junction

6 "

second junction

6a

Return line

6b

AGR valve

6c

EGR cooler

7th

Heat exchanger

8th

Air purification device

9

Particle filter

10

Liquid cooling

10a

Coolant circuit

11

Heating device

QUOTES INCLUDED IN THE DESCRIPTION

This list of the documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent literature cited

• US 8297922 B1 [0024]

Claims (15)

Supercharged internal combustion engine (1) with - a liquid cooling (10) comprising a - a coolant - coolant circuit (10a), - an intake system (2) for supplying charge air, - an exhaust gas removal system (3) for removing exhaust gas, - at least one for Compression of the charge air in the intake system (2) arranged compressor (4), which comprises at least one impeller mounted in a compressor housing on a rotatable shaft and equipped with rotor blades, - an exhaust gas recirculation (6) comprising a recirculation line (6a), the upstream of the at least one Compressor impeller opens into the intake system (2) with the formation of a first node (6 '), and - a heat exchanger (7) which is arranged upstream of the first node (6') in the intake system (2) and is integrated into the coolant circuit (10a) and a heat transfer between the charge air and the coolant, characterized in that - upstream of the heat exchanger (7) an e Electrically operated heating device (11) is arranged in the coolant circuit (10a). Supercharged internal combustion engine (1) after Claim 1 , characterized in that the return line (6a) branches off from the exhaust gas discharge system (3) with the formation of a second junction (6 "). Supercharged internal combustion engine (1) after Claim 1 or 2 , characterized in that no consumer is arranged in the coolant circuit (10a) between the heat exchanger (7) and the electrically operated heating device (11). Supercharged internal combustion engine (1) according to one of the preceding claims, characterized in that an air cleaning device (8) is arranged upstream of the first node (6 ') in the intake system (2). Supercharged internal combustion engine (1) after Claim 4 , characterized in that the air cleaning device (8) and the heat exchanger (7) are designed as a common, integrative component. Supercharged internal combustion engine (1) according to one of the preceding claims, characterized in that the at least one compressor (4) has an inlet area which runs coaxially to the shaft of the compressor (4) and is designed so that the charge air flows to the compressor ( 4) takes place essentially axially. Supercharged internal combustion engine (1) according to one of the preceding claims, characterized in that the at least one compressor (4) arranged in the intake system (2) belongs to an exhaust gas turbocharger (5) which has a turbine (5b) arranged in the exhaust gas discharge system (3) and a comprises the compressor (5a) arranged in the intake system (2). Supercharged internal combustion engine (1) after Claim 7 , characterized in that the return line (6a) branches off from the exhaust gas discharge system (3) downstream of the turbine (5b) of the exhaust gas turbocharger (5) to form a second node (6 "). Supercharged internal combustion engine (1) after Claim 8 , characterized in that a first shut-off element is arranged in the exhaust gas discharge system (3) downstream of the second node (6 "). Supercharged internal combustion engine (1) according to one of the preceding claims, characterized in that a second shut-off element (2b) is arranged in the intake system (2) upstream of the first node (6 '). Supercharged internal combustion engine (1) according to one of the preceding claims, characterized in that an EGR cooler (6c) is arranged in the return line (6a). Supercharged internal combustion engine (1) according to one of the preceding claims, characterized in that an EGR valve (6b) is arranged in the return line (6a). Method for operating a supercharged internal combustion engine (1) according to one of the preceding claims, characterized in that the electrically operated heating device (11) is activated in order to increase the temperature of the coolant before entering the heat exchanger (7) and using the heated coolant Bringing heat into the charge air and increasing the charge air temperature. Procedure according to Claim 13 , characterized in that the electrically operated heating device (11) is activated if condensation is expected in the intake system (2). Procedure according to Claim 13 or 14th , characterized in that the electrically operated heating device (11) is activated after a cold start of the internal combustion engine (1).

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