DE102018209398A1 - dosing - Google Patents

Abstract

Dosing module (1) for feeding a reducing agent (10) into an exhaust gas duct (3) of an internal combustion engine (4) with an injection valve (6) for setting the amount of the reducing agent (10) dispensed by the dosing module (1), a dosing module base body (5), on which the injection valve (6) is arranged, at least one annular cooling fluid channel (16) in the dosing module base body (5) for passing a cooling fluid (22), a cooling fluid supply channel (18) for supplying the cooling fluid (22) to the cooling fluid channel (16), a cooling fluid discharge channel (20) for removing the cooling fluid (22) from the cooling fluid channel (16), and a guide plate (27) which runs through the cooling fluid channel (16). The guide plate (27) divides the annular cooling fluid channel (16) at least in sections into an outer cooling fluid channel area (16a) in the radial direction and an inner cooling fluid channel area (16b) in the radial direction. The cooling fluid supply channel (18) is led horizontally or obliquely from below to a cooling fluid supply connection point (25a) on the dosing module base body (5), and the cooling fluid supply channel (20) is connected from a cooling fluid discharge line connection point (25b) adjacent to the radially outer cooling channel area (16a) on the dosing module base body. 5) led upwards.

Description

The invention relates to a metering module for feeding a reducing agent into the exhaust line of an internal combustion engine. The invention also relates to an exhaust line with such a metering module.

State of the art

In the field of exhaust gas aftertreatment, SCR (Selective Catalytic Reduction) systems are known which have the task of reducing nitrogen oxides (NO _x ) in the exhaust gas of an internal combustion engine, in particular a diesel engine, of a motor vehicle.

Using a so-called dosing module, these systems inject a urea water solution upstream of an SCR catalytic converter into the exhaust system of the internal combustion engine. In chemical processes, the urea is then converted into nitrogen (N ₂ ) and water (H ₂ O) in cooperation with the SCR catalyst. The nitrogen content in the exhaust gas is reduced.

During operation of the vehicle, temperatures of a few hundred degrees Celsius arise at the position of the dosing module. Therefore, cooling is provided on the metering module in the prior art in order to prevent temperature damage thereon and to ensure its functionality. This is done less widely with air cooling, but more often with water cooling.

Especially in the so-called "hot shutdown" (vehicle is switched off, and cooling water no longer circulates in the cooling circuit when the exhaust system is hot, because the cooling water pump was also switched off when the combustion engine was stopped), the injection valve inside the metering module is subjected to high thermal stresses, because the cooling effect in This phase is only reduced and the exhaust system is still hot. Furthermore, in this case only the cooling water in the metering module itself is available for cooling and it is possible that this cooling water starts to boil and the steam pushes cooling water out of the metering module, which additionally has an unfavorable effect on the cooling effect. The functionality of the injection valve as part of the dosing module can be impaired by overheating.

Disclosure of the Invention:

It is therefore an object of the invention to provide a metering module with improved cooling when the internal combustion engine is switched off.

This object is achieved by the subject matter of the independent patent claim. Advantageous further developments result from the dependent claims.

A dosing module according to the invention for feeding a reducing agent into the exhaust line of an internal combustion engine, in particular a diesel engine, has the following: an injection valve for setting the amount of the reducing agent dispensed by the dosing module, a dosing module base body on which the injection valve is arranged, at least one annular cooling fluid channel in the dosing module base body for passing a cooling fluid, in particular cooling water, and thereby cooling the metering module, a cooling fluid supply duct for supplying the cooling fluid to the cooling fluid duct, a cooling fluid discharge duct for discharging the cooling fluid from the cooling fluid duct, and a guide plate which runs through the cooling fluid duct for guiding the flow of the cooling fluid. The guide plate divides the annular cooling fluid channel at least in sections into an outer cooling fluid channel region in the radial direction (radial direction) and an inner cooling fluid channel region in the radial direction. If the metering module is installed in a ready-to-use installation position on the exhaust line, the cooling fluid supply channel is led horizontally or obliquely from below to a cooling fluid supply connection point on the metering module base body, and the cooling fluid discharge channel is adjacent to the radially outer cooling channel area from a cooling fluid discharge line connection point on the metering module base body, so that it is possible to lead away from the metering module base Steam can rise in the cooling fluid.

The metering module is arranged on the exhaust line of a motor vehicle in front of an SCR catalytic converter, which has the task of reducing nitrogen oxides (NO _x ) in the exhaust gas of the internal combustion engine, in particular the diesel engine. By means of the metering module, a reducing agent, for example a urea water solution, is fed into the exhaust line before the SCR catalytic converter. Together with the SCR catalyst, the urea is converted into nitrogen (N ₂ ) and water (H ₂ O). This reduces the nitrogen content in the exhaust gas.

In the context of the present description, the information “horizontal”, “vertical”, “top” and “bottom” is understood to refer to the metering module that is operationally installed on an exhaust system of a motor vehicle. The motor vehicle is at ground level for this, i.e. not on a slope.

The cooling fluid used is preferably cooling water, ie water to which corrosion inhibitors, antifreeze, boiling point boosters and the like can be added. Likewise, other fluids, for example at room temperature are liquid, and pass into their gas phase at a boiling temperature, are used to cool the metering module.

The cooling fluid supply duct and the cooling fluid discharge duct can, for example, be formed in sections by hoses or pipes.

Steam in the cooling fluid channel can rise upward in the cooling fluid discharge channel, thus moving in the flow direction of the cooling fluid and can thereby support or drive the cooling fluid transport through the cooling fluid discharge channel. This also improves the cooling fluid circulation in the cooling fluid channel. This has a positive effect on the cooling of the dosing module.

Since the cooling fluid supply duct is guided horizontally or from below to the dosing module base body, the probability of steam flowing into the cooling fluid supply duct is reduced. A braking of the flow of the cooling fluid by steam rising counter to the flow direction is thus avoided and the flow of the cooling fluid through the cooling fluid supply duct, the cooling fluid duct and the cooling fluid discharge duct is improved.

The baffle runs in the cooling fluid channel and serves to guide the flow of the cooling fluid or cooling water. Because the guide plate divides the annular cooling fluid channel at least in sections into an outer cooling fluid channel region in the radial direction and an inner cooling fluid channel region in the radial direction, the cooling fluid is likewise divided into two annular shells. In the radial direction on the inside meant with regard to the cooling channel running in a ring around the injection valve, near the injection valve and in the radial direction on the outside means further away. The heat on the exhaust line comes from the outside of the metering module, whereby vapor bubbles are also preferably generated in the outer ring shell of the metering module. The baffle keeps these vapor bubbles outside in the radially outer cooling fluid channel area, from where they are discharged upwards into the cooling fluid discharge channel. The vapor bubbles in the cooling fluid rise upward, are transported through the cooling fluid channel and preferably reach the cooling fluid discharge channel connected continuously to the cooling fluid channel. The vapor bubbles drive the transport of the fluid through their rise in the rising cooling fluid discharge channel.

For example, the baffle plate is designed as a grid and allows cooling fluid to flow through to a certain extent, with a separating effect from cooling fluid that is heated in the radial direction to less heating in the radial direction inside is nevertheless achieved. Likewise, the baffle plate can only be provided in an upper area of the cooling channel and, for example, can be led to a height just below, for example 1 cm below, the cooling fluid supply connection point, in order to enable a cooling fluid exchange between the cooling fluid channel area that is in the radial direction and the cooling fluid channel area that is in the radial direction ,

According to one embodiment of the metering module, the cooling fluid supply duct opens into the cooling fluid duct region that is inner in the radial direction. Part of the cooling fluid supply channel is formed, for example, by means of a sleeve which projects from the outside in the radial direction into the metering module base body into the cooling fluid channel region which is inner in the radial direction. The protrusion of the cooling fluid supply channel into the cooling fluid channel region, which is inner in the radial direction, improves a separation of the cooling fluid flowing into the cooling channel from the cooling fluid, which is arranged radially on the outside in the cooling channel, is strongly heated and can therefore contain steam. The probability of an inflow of steam from this heated, radially outer cooling fluid into the cooling fluid supply channel is thereby reduced.

According to one embodiment of the dosing module, the dosing module additionally comprises a heat store, which is connected in a thermally conductive manner to the cooling fluid discharge duct in order to cool the cooling fluid discharge duct and thus to condense possible steam in the cooling fluid. In order to prevent even more effectively that steam or gas bubbles can collect in the cooling fluid discharge duct, in particular in the region of a highest point of the cooling fluid discharge duct, and that these hinder the flow there, the heat store is additionally provided. The heat accumulator is cooler in operation than the temporarily heated cooling fluid discharge duct and can therefore absorb heat from it and thus cool it. By cooling the cooling fluid discharge channel, gas bubbles in the cooling fluid discharge channel are condensed and removed. The heat store is arranged, for example, above the base of the metering module. Furthermore, the heat accumulator is preferably arranged at or below the highest point of the cooling fluid discharge duct in order to remove gas bubbles in the cooling fluid by condensation before they can accumulate there. The heat accumulator offers the advantage of a technically simple, fault-resistant construction and a small space requirement. The heat storage differs from cooling fins in that it is more solid, therefore has a high heat capacity and can absorb a lot of heat energy in a short time.

According to a further embodiment of the metering module, the heat store is as Heat storage plate, in particular essentially made of steel or aluminum. The plate-like structure allows heat to be dissipated well from the cooling fluid discharge duct. The heat capacity relevant volume of the heat accumulator can be provided away from the actual cooling fluid discharge duct. This offers advantages in terms of spatial arrangement. Furthermore, a plate-shaped, ie flat, heat accumulator can be attached particularly well to a motor vehicle and can also serve as a holder for a tube or a hose in which the cooling fluid discharge duct is formed. The material thickness of the heat storage plate can be, for example, 4 to 20 mm in order to offer a large heat dissipation capacity.

The functionality of removing the gas bubbles by means of the heat store is not limited by the amount of gas. Both steel and aluminum as a material for the heat store have a high specific heat capacity, so that the heat store can offer a high heat capacity with small desired dimensions. Steel offers a particularly high strength as a material and enables a variety of connection options for the heat accumulator, since it is particularly easy to weld. Aluminum has the advantage of low weight. Alloys of steel or aluminum can also be used.

According to a further embodiment of the metering module, the heat store has a volume of 20 to 90 cm ³ . A volume of the heat accumulator of 20 to 90 cm ³ offers a good heat capacity in a small installation space in order to rapidly cool temperature peaks in the cooling fluid discharge duct in order to reduce steam in the cooling water by condensation.

According to a further embodiment of the metering module, cooling fins are provided on the cooling fluid discharge duct. Due to their large surface area, the cooling fins enable good heat dissipation of heat from the cooling fluid discharge duct to the surroundings. A combination of the heat accumulator and the cooling fins can also be used.

According to a further embodiment of the dosing module, the cooling fluid discharge channel runs between the cooling fins and the heat accumulator. This arrangement achieves particularly good cooling of the cooling fluid discharge duct, since heat can be given off to the heat accumulator, for example the heat storage plate, on one side of the cooling fluid discharge duct circumference and heat can be emitted by means of the cooling ribs on the other side of the cooling fluid discharge duct circumference. The cooling by the heat accumulator and the cooling fins complement each other well. While short-term temperature peaks can be released into the heat accumulator with its high heat capacity due to its material thickness, the cooling fins can release a large amount of thermal energy into the environment over time thanks to their large surface area. With this arrangement, this results in a good time behavior of the cooling of the cooling fluid discharge channel, both in the case of temperature peaks in the cooling fluid and with regard to the constant heat dissipation.

According to a further embodiment of the dosing module, the cooling fluid supply channel is led from the dosing module base body at a first angle of 0 to 80 degrees to the horizontal and / or the cooling fluid discharge channel is led away from the dosing module base body at a second angle from 0 to 80 degrees to the vertical.

According to a further embodiment of the dosing module, the cooling fluid supply connection point is arranged in such a way that an upper part of the cooling fluid channel lies higher than the cooling fluid supply connection point and a lower part of the cooling fluid channel lies lower than the cooling fluid supply connection point. If it happens that the steam cannot be completely absorbed by the cooling fluid supply duct leading upwards, the lateral connection of the cooling fluid supply duct prevents the entire cooling water volume of the cooling duct from draining, since at least in the area that is deeper than the connection point of the side connection Cooling fluid supply channel is on the dosing module base body, cooling fluid remains. The steam can flow over the remaining cooling water volume in the area below the cooling fluid supply connection point without forcing it out of the cooling fluid channel.

An exhaust line according to the invention for removing the exhaust gases from an internal combustion engine, in particular a diesel engine, has a metering module according to the invention and an SCR catalytic converter. The dosing module is arranged upstream of the SCR catalytic converter.

list of figures

• 1 shows an exhaust system of an internal combustion engine with a metering module for injecting a reducing agent into an exhaust duct of the exhaust system in a schematic representation.
• 2 shows a dosing module according to the prior art in a schematic representation;
• 3 shows a dosing module according to a first embodiment in a schematic representation;
• 4 shows the dosing module according to the first embodiment in a schematic representation;
• 5 shows the dosing module according to the first embodiment with two alternative courses of the cooling fluid supply channel and the cooling fluid discharge channel in a schematic representation;
• 6 shows a dosing module according to a second embodiment in a schematic representation;
• 7 shows a dosing module according to the second embodiment in a schematic sectional view; and
• 8th shows a dosing module according to a third embodiment in a schematic sectional view.

figure description

Several embodiments of the invention are described below with reference to the accompanying figures.

In the figures, the same reference numerals designate identical or functionally identical components, unless stated otherwise.

1 shows an exhaust line 2 of an internal combustion engine 4 with a dosing module 1 for injecting a reducing agent into an exhaust duct 3 of the exhaust line 2 in a schematic representation.

The dosing module 1 is between the internal combustion engine 4 and an SCR catalyst 7 , ie the SCR catalytic converter 7 upstream, arranged. The dosing module 1 includes an injector 6 for setting the delivery quantity of a reducing agent 10 through the dosing module 1 , By a pre-feed pump 8th becomes the reducing agent to be injected 10 from a storage tank 12 removed and the dosing module 1 , for example, at a pressure of 2 to 3 bar. The dosing module 1 injects the reducing agent 10 with a high pressure, for example a pressure of 10 bar, in the exhaust duct 3 of the exhaust line 2 on. In the exhaust duct 2 the injected reducing agent mixes with those through the exhaust duct 3 flowing exhaust gases 14 and reacts in the downstream of the dosing module 1 arranged SCR catalyst 7 with those in the exhaust 14 contained nitrogen oxides (NO _x ), so that they are reduced to N ₂ and H ₂ O.

2 shows a dosing module 1 according to the prior art in a schematic representation.

The dosing module 1 has a cooling fluid channel 16 on that in a dosing module base body 5 of the dosing module 1 is provided and is shown in a ring shape in the picture. A cooling fluid supply channel 18 and a cooling fluid drainage channel 20 of the dosing module 1 protrude from the dosing module base body 5 up away. In the picture is the direction of gravity, ie the direction downwards, by an arrow G displayed. The cooling fluid channel 16 is used to pass a cooling fluid 22 and thus cooling the dosing module 1 , This enables the dosing module 1 cooled and operated in an advantageous temperature range. The cooling fluid 22 is cooling water according to this embodiment, for example from the cooling circuit of the cooling of the internal combustion engine 4 is branched off.

In this known metering module 1 protrude both the cooling fluid supply channel 18 as well as the cooling fluid drainage channel 20 upwards from the dosing module base body 5 path. Steam forms 24 , for example in the form of gas bubbles, in the cooling fluid 22 , the steam could 24 both in the cooling fluid supply line 18 as well as in the cooling fluid drainage channel 20 flow. In this case the steam would 24 in the cooling fluid supply channel 18 against the direction of flow of the cooling fluid 22 flow, which is negative in terms of a rapid and turbulence-free flow of the cooling fluid 22 and thus negatively affects the cooling of the dosing module 1 can impact.

3 shows a dosing module 1 according to a first embodiment in a schematic representation. The dosing module 1 comprises a dosing module base body 5 on which an injection valve 6 for setting the delivery quantity of a reducing agent 10 through the dosing module 1 is provided. Through the dosing module base body 5 runs a cooling fluid channel 16 for passing a cooling fluid 22 , The cooling fluid 22 is cooling water according to this embodiment. A cooling fluid supply channel 18 is in the picture coming from the right to the dosing module base 5 connected. The cooling fluid supply channel 18 runs in this embodiment in the last section, where it goes to the dosing module base 5 is, approximately horizontally. The direction of gravity is again shown by an arrow G in the image. The cooling fluid supply channel 18 is approximately horizontal to a cooling fluid supply connection point in this exemplary embodiment 25a on the dosing module base body 5 be led. The basic dosing module 5 includes a protruding first connection piece 26a in which the cooling fluid supply channel 18 runs into it. In this embodiment, the cooling fluid supply channel is 18 sectionally delimited by a hose that the connecting piece 26a is attached to the cooling fluid supply channel 18 tight with the cooling fluid channel 16 connect to. The first connector 26a is made of a rigid material and gives the cooling fluid supply channel 18 from the dosing module base body 5 starting a horizontal direction.

The cooling fluid drainage channel 20 is upward from a cooling fluid discharge line connection point in this embodiment 25b on the dosing module base body 5 led away. A second connection piece 26b of the dosing module base body 5 protrudes approximately vertically upwards in this embodiment and holds a hose which, in this embodiment, the cooling fluid discharge channel 20 limited, in the vertical direction upwards. The cooling fluid drainage channel 20 is like the cooling fluid supply channel 18 fluid technology with the cooling fluid channel 16 connected.

The cooling fluid flows during operation 22 through the cooling fluid supply channel 18 in the dosing module base body 5 cools down the injection valve in particular 6 of the dosing module 1 and then flows from the dosing module base body 5 into the cooling fluid drainage channel 20 , flow arrows S on the cooling fluid supply channel 18 and on the cooling fluid drainage channel 20 show the flow direction of the cooling fluid 22 ,

steam 24 rises in the cooling fluid drainage channel 20 up. The steam flows with it 24 in the same direction through the cooling fluid drainage channel 20 like the cooling fluid 22 and thus supports the movement of the cooling fluid 22 , Furthermore, the build-up of steam 24 in the cooling fluid drainage channel 20 avoided because of the steam 24 with the flow of the cooling fluid 22 is moved.

Because only the cooling fluid drainage channel 20 the steam comes up 24 preferably in the cooling fluid discharge channel 20 and not in the cooling fluid supply channel 18 what for the circulation of the cooling fluid 22 is beneficial.

A baffle 27 is through the cooling fluid channel 16 running to the flow of the cooling fluid 22 intended. The baffle 27 divides the annular cooling fluid channel 16 in a section in a radially outer cooling fluid channel region 16a and a radially inner cooling fluid channel region 16b on. The cooling fluid supply channel 18 In this exemplary embodiment, it opens directly into the cooling fluid channel region which is inner in the radial direction 16b on. Part of the cooling fluid supply channel 18 is in this embodiment by means of a sleeve as a connecting piece 26a formed in the radial direction from the outside in the dosing module base body 5 down to the radially inner cooling fluid channel area 16b protrudes. The protrusion of the cooling fluid supply channel 18 in the radially inner cooling fluid channel area 16b improves separation of the cooling fluid channel 16 incoming cooling fluid 22 of the cooling fluid 22 that in the cooling fluid channel 16 arranged in the radial direction on the outside, very hot and can therefore contain steam. The probability of an inflow of steam 24 from this heated external cooling fluid in the radial direction 22 into the cooling fluid supply channel 18 is reduced.

vapor bubbles 24 when the metering module is exposed to external heat 1 preferably in the outer cooling fluid channel in the radial direction 16a of the dosing module 1 arise, are held by the baffle with the flow outside, from where it goes up into the cooling fluid drainage channel 20 be delivered.

4 shows the dosing module 1 according to the first embodiment in a schematic representation. Here the condition is shown when the steam 24 not completely from the upward cooling fluid drainage channel 20 can be included. If the steam 24 not completely from the upward cooling fluid drainage channel 20 can be accommodated, prevents the side connection of the cooling fluid supply channel 18 an empty running of the entire cooling water volume of the cooling fluid channel 16 , because at least in the area of the cooling fluid channel 16 that is deeper than the cooling fluid supply channel 18 in the area of the first connector 26a lies, cooling fluid 22 remains.

5 shows the dosing module 1 according to the first embodiment with two alternative courses of the cooling fluid supply channel 18 and the cooling fluid drainage channel 20 in a schematic representation. A variation of the cooling fluid supply channel 18 is with a double arrow W1 characterized. The cooling fluid supply channel 18 can be done directly horizontally or from below at an angle W1 coming to the horizontal to the dosing module base 5 be led there. A variation of the cooling fluid drainage channel 20 is with a double arrow W2 characterized. The cooling fluid drainage channel 20 is varied here by way of example and runs directly vertically upwards or alternatively can be at an angle W2 from the dosing module base body 5 be led away.

6 shows a dosing module 1 according to a second embodiment in a schematic representation. In addition to the elements known from the first exemplary embodiment, there is a heat store in this exemplary embodiment 28 at the cooling fluid drainage channel 20 intended. The heat storage 28 is thermally conductive with the cooling fluid drainage channel 20 connected to the cooling fluid drainage channel 20 to cool and steam 24 in the cooling fluid 22 to condense. In this embodiment, the cooling fluid drainage channel is 20 formed in a tube that connects to the heat accumulator 28 is welded, so that it also has the function of fixing the position of the cooling fluid discharge duct 20 takes over. The heat storage 28 can quickly absorb large amounts of thermal energy due to its heat capacity and thus temperature peaks in the cooling fluid discharge duct 20 avoid. In this embodiment, the heat accumulator 28 made of steel, square in shape, has an edge length of 5 cm by 10 cm, a thickness of 0.5 cm and thus a volume of 25 cm ³ . The heat storage 28 differs from conventional coolers in its larger material volume and thus the better absorption capacity with regard to thermal energy. A quick temporary cooling is through the heat accumulator 28 possible, even if it does not have a particularly large surface for heat emission. This allows technically simple, reliable, effective cooling of the cooling fluid discharge duct, which is compact in terms of installation space 20 to provide.

In this embodiment, the heat accumulator 28 at a highest point of the cooling fluid drainage channel 20 arranged. The highest point is particularly critical because the steam likes to be here 24 accumulates the drain of the cooling fluid 22 hampered and even blocked the cooling fluid drainage channel 20 can lead. Through the heat storage 28 becomes the steam 24 condensed there again, and a blockage of the cooling fluid discharge channel 20 through the steam 24 counteracted effectively.

7 shows a dosing module 1 according to the second embodiment in a schematic sectional view.

The heat storage 28 , executed as a steel plate, is clearly recognizable as a rectangle on the left in the picture. The cooling fluid drainage channel 20 is shown as a circle to the right of it. A welded joint 30 connects the heat storage 28 and the cooling fluid drainage channel 20 , The plate-shaped heat storage 28 in this exemplary embodiment also takes on the task of fixing the position of the cooling fluid discharge duct 20 ,

8th shows a dosing module 1 according to a third embodiment in a schematic sectional view. This third embodiment differs from the second embodiment in that in addition to the heat accumulator 28 , Cooling fins 32 thermally conductive with the cooling fluid drainage channel 20 are provided connected. The combination of heat storage 28 and cooling fins 32 offers particularly fast heat dissipation from the cooling fluid discharge duct 20 in the heat accumulator 28 combined with good heat dissipation to the environment via the cooling fins 32 ,

Claims (10)

Dosing module (1) for feeding a reducing agent (10) into an exhaust duct (3) of an exhaust line (2) of an internal combustion engine (4), in particular a diesel engine an injection valve (6) for adjusting the amount of the reducing agent (10) dispensed by the metering module (1), a dosing module base body (5) on which the injection valve (6) is arranged, at least one annular cooling fluid channel (16) in the dosing module base body (5) for passing a cooling fluid (22), in particular cooling water, for cooling the dosing module (1), a cooling fluid supply channel (18) for supplying the cooling fluid (22) to the cooling fluid channel (16), a cooling fluid discharge channel (20) for discharging the cooling fluid (22) from the cooling fluid channel (16), and a baffle (27) which runs through the cooling fluid channel (16) for guiding the cooling fluid (22), the guide plate (27) dividing the annular cooling fluid channel (16) at least in sections into a cooling fluid channel region (16a) which is outer in the radial direction and a cooling fluid channel region (16b) which is inner in the radial direction, wherein the cooling fluid supply channel (18) is guided horizontally or obliquely from below to a cooling fluid supply connection point (25a) on the dosing module base body (5) when the dosing module (1) is installed in an operational installation position on the exhaust line (2), and wherein the cooling fluid discharge duct (20) is led upwards from a cooling fluid discharge line connection point (25b), which adjoins the radially outer cooling duct region (16a) in the dosing module base body (5), when the dosing module (1) is in the ready-to-use installation position on the exhaust line (2) is installed. Dosing module (1) after Claim 1 , characterized in that the cooling fluid supply duct (18) opens into the radially inner cooling fluid duct region (16b). Dosing module (1) after Claim 1 or 2 , characterized in that the metering module (1) additionally comprises a heat accumulator (28) which is thermally conductively connected to the cooling fluid discharge duct (20) in order to cool the cooling fluid discharge duct (20) and thus possible steam (24) in the cooling fluid (22) to condense. Dosing module (1) after Claim 3 , characterized in that the heat accumulator (28) as a heat accumulator plate, in particular in the Made essentially of steel or aluminum. Dosing module (1) after Claim 3 or 4 , characterized in that the heat accumulator (28) has a volume of 20 to 90 cm ³ . Dosing module (1) according to one of the preceding claims, characterized in that cooling ribs (32) are provided on the cooling fluid discharge duct (20). Dosing module (1) after Claim 6 , characterized in that the cooling fluid discharge channel (20) runs between the cooling fins (32) and the heat accumulator (28). Dosing module (1) according to one of the preceding claims, characterized in that the cooling fluid supply duct (18) is guided at a first angle (W1) from 0 to 80 degrees to the horizontal to the dosing module base body (5) and / or the cooling fluid discharge duct (20) in one second angle (W2) of 0 to 80 degrees to the vertical is guided away from the dosing module base body (5). Dosing module (1) according to one of the preceding claims, characterized in that the cooling fluid supply connection point (25a) is arranged such that an upper part of the cooling fluid channel (16) is higher than the cooling fluid supply connection point (25a) and a lower part of the cooling fluid channel (16) is lower as the cooling fluid supply port (25a). Exhaust line (2) with an exhaust duct (3) for removing the exhaust gases of an internal combustion engine (4), in particular a diesel engine, with a metering module (1) according to one of the Claims 1 to 9 , The exhaust line has an SCR catalytic converter (7) and the metering module (1) is arranged upstream of the SCR catalytic converter (7).

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