JP2017524856A - Exhaust gas system, method for controlling exhaust gas system and computer program product - Google Patents

Abstract

The present invention relates to a thermal energy recovery system (100) in a vehicle (500) including an internal combustion engine (12) such as a diesel engine. The invention relates to a method of operating such a system (100), the method comprising detecting the pressure of the working fluid in the gas phase in the working fluid circulation circuit (11) and the vehicle (500). Adjusting the pressure to meet one of a plurality of predetermined conditions that depend on different operating conditions. [Selection] Figure 6

Description

  The present invention generally relates to a thermal energy recovery system in a vehicle including an internal combustion engine such as a diesel engine. The invention also relates to a method of operating such a system.

  Recent advances in the efficient operation of internal combustion engines include the use of thermodynamic engines, particularly Rankine cycle engines, for waste heat regeneration. As is generally known, the Rankine cycle engine is an engine that converts heat into work. Heat is applied externally to a closed working fluid circulation circuit, which may use water or other suitable liquid as the working fluid. The pump is used to pressurize the liquid phase working fluid received from the condenser, after which the liquid phase working fluid is heated and thereby converted to the gas phase. Subsequently, the gas phase working fluid is transferred to the steam engine where thermal energy is converted to kinetic energy. In a further step, the gas phase working fluid is converted back to its liquid phase in the condenser.

  A common working fluid is water that is easy to supply, is already present in the vehicle and is harmless to the environment. Even with the attractive properties of water, there are some drawbacks. For example, when steam is mixed with air, the functionality of the steam engine decreases. Furthermore, a small amount of air in the steam can be quite aggressive against the construction material. In order to avoid the accumulation of air in the steam, it has been proposed to keep the pressure of the working fluid above atmospheric pressure. This disadvantageously results in constraining efficiency as the condensation temperature needs to be relatively high (especially above 100 ° C.). However, during longer stops (nighttime, weekends, etc.) it is difficult to avoid a pressure drop below ambient pressure in the system, resulting in air leaking into the system. Furthermore, in some designs it is further preferred to have a pressure lower than ambient pressure in some parts of the Rankine cycle for good efficiency.

  Furthermore, water becomes a problem as a working fluid, for example, water freezes at 0 ° C. In US201012304, the freezing point is lowered by trying to solve the freezing problem by mixing a small amount of ammonia or alcohol with water. In addition, since ammonia or alcohol lowers the dew point, condensation can be performed at low temperatures.

  Disadvantageously, ammonia is corrosive and harmful. Therefore, ammonia must be handled with great care and must not be released to the environment. However, such emissions can occur, for example, in the event of an accident involving a thermodynamic engine or a vehicle containing such an engine (eg, a collision of a vehicle with another vehicle) or maintenance of a thermodynamic engine and / or vehicle. Inevitable inside. In the past, expander device bypasses have been used to release working fluid pressure and provide the possibility of safe maintenance. Disadvantageously, this procedure is very time consuming, the vehicle stationary time in the workplace is unnecessarily long, and / or the waiting time for the rescue team to access the vehicle safely is unacceptable, for example. It becomes long to the extent.

  According to one aspect of the present invention, the foregoing is at least partially mitigated by a vehicle exhaust gas system, and a mechanism for transmitting an exhaust gas flow and an exhaust gas flow for recovering heat from the exhaust gas flow. A thermodynamic engine including a working fluid circulation circuit holding a working fluid containing a heat exchanger disposed therein and a first basic component mixed with a first additional component at a selected concentration; and at least of the working fluid And a first container fluidly connected to the working fluid circulation circuit for storing a quantity of the first additional component, wherein the first container is the working fluid circulation circuit. The working fluid pressure in the gas phase within the working fluid circulation circuit is adapted to meet one of a plurality of predetermined conditions. The multiple predetermined conditions are Depending on the different operating conditions of the vehicle.

  A common use of the exhaust gas system according to the present invention is to achieve useful recovery of waste heat from an internal combustion engine typically installed in a vehicle. By advantageously introducing a first vessel fluidly connected to the gas phase in the working fluid circulation circuit, it is possible to typically quickly change the gas pressure in the event of a deviation from one of the predetermined conditions can do. Thus, the working fluid to be optimized can be fine-tuned towards the operating state of the vehicle and can include, for example, conditions in the surroundings of the vehicle in relation to temperatures in the surrounding environment.

  In one exemplary embodiment, the pressure detector may be included in the exhaust gas system and placed in the gas phase within the working fluid circulation circuit. However, instead of being explicitly provided for use in exhaust gas systems, it is also possible to obtain the detected pressure using a pressure detector that is alternatively arranged as a component of a complete vehicle system It is.

The first vessel can preferably be configured to provide both an increase and a decrease in pressure in the gas phase in the working fluid circulation circuit, for example using a connected pump. Thus, the first container may include a bidirectional valve control connection to the working fluid circulation circuit.
However, in a preferred embodiment of the present invention, the exhaust gas system further comprises a second vessel connected to the working fluid circulation circuit in the gas phase within the working fluid circulation circuit, the second container in several operating stages of the system. This container is used to reduce the gas pressure in the working fluid circulation circuit, for example using a pump. Thus, in such embodiments, the first vessel is essentially used to increase the gas pressure in the working fluid circulation circuit (eg, introduction of an “excessive amount” of working fluid).
Thus, the first and second containers work together to optimize the gas pressure in the working fluid circulation circuit to meet at least one of the predetermined conditions.

  Such predetermined conditions may further extend to the above general introduction in relation to vehicle safety conditions. For example, in the case of inspection or maintenance of a vehicle or an exhaust gas system, it is desirable to reduce the pressure in the working fluid circulation circuit, thus making it easier to check the exhaust gas system. Similarly, in the event of an emergency or accident, such a pressure drop is also desirable to reduce the risk of response personnel involved in handling the following emergency / accident procedures.

  Further, introducing an excessive amount of working fluid into the gas phase in the working fluid circulation circuit may allow a reduction in the air accumulation tendency of the thermodynamic engine due to ambient air leaking into the system. Such conditions typically occur when the vehicle is stationary (shutdown), such as at night and weekends when the vehicle is not in use. Preferably, this supply occurs when a pressure below ambient pressure is detected on the high pressure side in the circulation circuit and an additional amount of working fluid can compensate for the pressure drop.

  Within the context of the present invention, pressure is introduced by introducing an additional amount of working fluid into the working fluid circulation circuit or by adjusting the selected concentration of the first additional component relative to the first basic component. Can be adjusted. A typical scenario where this is possible is when the first basic component of the working fluid is water and the first additional component of the working fluid is ammonia.

In a preferred embodiment of the present invention, the exhaust gas system further comprises a working fluid discharge means such as a selective catalytic reduction (SCR) unit and an exhaust treatment unit. Thereby, the SCR can be used to temporarily store excess working fluid to reduce the pressure in the working fluid circulation circuit. This is particularly advantageous when the working fluid contains a combination or water and ammonia. Specifically, by using a selective catalytic reduction unit that uses ammonia to reduce nitrogen oxide (NO _x ) emissions, the catalytic component of the SCR temporarily stores ammonia, which is the using in _the nO _x reduction step, i.e., direct, since the environment is not released, allowing the possibility of advantageous use of the "released" temporarily excessive working fluid.

  In some embodiments, the SCR is fed not only with water / ammonia from the working fluid circulation circuit through the working fluid discharge means, but also with an additional source of ammonia. Thereby, a synergistic effect is provided, enabling a system that not only regenerates the waste energy of the internal combustion engine but also provides a working fluid release without problems.

  However, in some conditions it is possible to utilize water / ammonia from the working fluid circulation circuit rather than obtaining ammonia from an additional source (eg, an externally disposed tank on the vehicle). possible. Such a condition is associated with, for example, a cold start of a vehicle, and a warm provision of ammonia can be released from the working fluid circulation circuit compared to what can be achieved in a discharge from another source. .

  According to the present invention, it is possible to “replenish” ammonia from a further source, for example, from a tank provided on the vehicle and arranged externally, for example to the first and / or second container. Please note that. There may be a direct connection between the external tank and the first and / or second container, or alternatively, an intermediate process to “rebuild” the urea stored in the tank. A process may be introduced and supplied to the working fluid circulation circuit.

In addition, the use of ammonia as the first additional component of the working fluid minimizes the risk of problems when operating a cold vehicle, for example in winter conditions, because ammonia acts as an anti-freeze component . It is of course possible to use other (or further combined) types such as alcohols or antifreeze components.
Preferably, the concentration of ammonia and / or alcohol is measured, for example using a temperature sensor that measures the ambient temperature around the vehicle, and adapted to daily, weekly and / or monthly standards depending on the expected temperature fluctuations. Can do. Of course, it is also possible to adapt the concentration on a shorter or longer time scale.

  When ammonia is used as the first additional component of the working fluid, the first container is heated so that the ammonia in the first container is at a pressure higher than atmospheric pressure and / or higher than the working pressure. A fluid path that can be adapted to is provided at the connection of the first container. This has the advantage that no additional pump (as described above) is required to drive the flow of ammonia from the ammonia reservoir / tank to the working fluid circulation circuit. Ammonia is preferably provided in the form of urea.

According to a further preferred embodiment, the second container comprises liquid ammonia and / or an ammonia adsorbing material, preferably CaCl ₂ and / or MgCl ₂ and / or SRCl ₂ , an ammonia compound, preferably urea, ammonium carbamate and / or Or ammonium carbonate. Preferably, an ammonia adsorbing material or an ammonia compound is used. This is because the work with liquid ammonia requires additional safety precautions.

  In a preferred embodiment of the invention, the exhaust gas system further comprises a control unit electrically connected to the pressure detector, and using at least one controllable valve operatively connected to the control unit, The pressure of the working fluid is adjusted in a gas phase in the working fluid circulation circuit. Accordingly, the control unit is typically electrically connected to a pressure detector for obtaining the current pressure in the working fluid circulation circuit, and this measurement, the first and second containers, and the working fluid. An input for controlling the valve associated with the discharge means is used to provide a controllable connection between the working fluid circulation circuit and the SCR. The control unit typically includes processing means for adjusting the pressure in the working fluid circulation circuit to correspond to at least one of a plurality of predetermined vehicle conditions as described above. In addition, the control unit typically controls the concentration of the antifreeze component within the working fluid circulation circuit.

  In accordance with another aspect of the invention, a method is provided for controlling an exhaust gas system for a vehicle, the exhaust gas system having a mechanism for transmitting an exhaust gas stream and for recovering heat from the exhaust gas stream. A thermodynamic engine including a heat exchanger disposed in the exhaust gas stream and a working fluid circulation circuit holding a working fluid containing a first basic component mixed with a first additional component at a concentration; A first container for storing at least a quantity of the first additional component, wherein the first container is fluidly connected to the working fluid circulation circuit, the method in the gas phase in the working fluid circulation circuit Detecting the pressure of the working fluid and adjusting the pressure to meet one of a plurality of predetermined conditions that depend on different operating conditions of the vehicle. This aspect of the invention provides similar advantages as described above with respect to the above aspects of the invention.

  In one embodiment, the method further comprises disposing a pressure detector downstream of the heat exchanger in the gas phase within the working fluid circulation circuit, wherein the step of adjusting the pressure comprises a pressure detected by the pressure detector. Depends on.

  In another embodiment, adjusting the pressure depends on the ambient temperature detected by the temperature sensor. The pressure can be adjusted by adjusting the selected concentration of the first additional component with respect to the first basic component.

  In one embodiment, the method further comprises fluidly connecting the second container to the working fluid circulation circuit in a gas phase within the working fluid circulation circuit, wherein the first container is a pressure at one of the predetermined conditions. And the second container is configured to reduce pressure at another one of the predetermined conditions.

  According to yet another aspect of the present invention there is provided a computer program product comprising a computer readable medium having stored thereon computer program means for controlling an exhaust gas system for a vehicle, the computer program product being the above of the present invention. Includes code for performing the steps described above with respect to an aspect. This other aspect also provides the same advantages as discussed with respect to the above aspects of the invention.

  The computer program product is typically implemented using a control unit that preferably includes a microprocessor or any other type of computing device. Similarly, software executed by the control unit to operate the exhaust system of the present invention includes removable non-volatile random access memory, hard disk drive, floppy disk (registered trademark), CD-ROM, DVD-ROM, It can be stored on a computer readable medium that is any type of memory device including a USB memory, an SD memory card, or one of similar computer readable media known in the art. Thus, the present invention can be implemented using a combination of software and hardware elements.

  Additional features and advantages of the invention will be apparent from a review of the appended claims and the following description. Those skilled in the art will appreciate that different features of the present invention can be combined to create embodiments other than those described below without departing from the scope of the present invention.

  Various aspects of the invention, including its particular features and advantages, will be readily understood from the following detailed description and the accompanying drawings.

1 shows a vehicle equipped with an exhaust gas system according to a preferred embodiment of the present invention. It is a figure which shows an example of the conventional exhaust gas system. 1 is a schematic diagram of an exhaust gas system according to a preferred embodiment of the present invention. 1 is a schematic diagram of an exhaust gas system according to a preferred embodiment of the present invention. 1 is a schematic diagram of an exhaust gas system according to a preferred embodiment of the present invention. 1 is a schematic diagram of an exhaust gas system according to a preferred embodiment of the present invention.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the invention can be implemented in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided for completeness and completeness, and fully convey the scope of the invention to those skilled in the art. Like reference numerals refer to like elements.

  Referring now to the drawings and in particular to FIG. 1, an exemplary vehicle, shown here as a truck 500, is shown. The truck 500 is provided with a power source (12) that propels the truck through a drive line that connects the power source to the wheels. The power source (12) is constituted by an internal combustion engine in the form of a diesel engine. The vehicle (500) is provided with a storage tank 502 that holds the amount of urea used in the emission reduction process as described above.

FIG. 2 applies to the regeneration of waste energy of the internal combustion engine 12, enables reduction of nitrogen oxide (NO _x ) emissions by the exhaust treatment unit 20, and preferably is prior art for use with the internal combustion engine 12. 1 shows an example of the exhaust gas system 100. Exhaust treatment unit 20 is formed by using a selective catalytic reduction unit using ammonia to reduce the amount of NO _x in the exhaust. Ammonia is stored in an external storage tank 502, typically in the form of urea.

The exhaust gas system 100 includes a mechanism 17 for transmitting an exhaust gas flow 80 to the exhaust treatment unit 20, and the exhaust treatment unit 20 is included in the mechanism 17.
The exhaust gas system 100 further includes a thermodynamic engine 1 that operates in parallel with the exhaust treatment unit 20, and the thermodynamic engine 1 recovers heat from the exhaust gas flow 80 so that the exhaust gas flow transmission mechanism (17). It is connected to the. The thermodynamic engine 1 includes a working fluid circulation circuit 11. The thermodynamic engine 1 can operate according to the Rankine cycle, for example. In the embodiment shown in FIG. 2, the working fluid circulation circuit 11 is closed.

  The exhaust gas flow transmission mechanism (17) is arranged to receive the exhaust from the internal combustion engine 12. Furthermore, the waste heat of the internal combustion engine 12 is used as a heat source for the thermodynamic engine 1, which forms at least part of a waste heat recovery system for the internal combustion engine.

  The thermodynamic engine 1 moves the heat energy of the gas-phase working fluid, the pump device 2 that circulates the working fluid, the heating device (4) that heats the working fluid and converts the liquid-phase working fluid into the gas-phase working fluid Further included is an expander device 8 for converting to energy and a condensing device 10, which are interconnected by a working fluid circulation circuit 11. The heating device (4) is formed by a first heat exchanger arranged in the exhaust gas flow 80 from the internal combustion engine 12. In other words, the first heat exchanger 4 is connected to the exhaust side of the internal combustion engine 12 for heat exchange.

  The turbocharger 13 is disposed so as to be filled with air flowing into the internal combustion engine 12. The turbocharger 13 includes a turbine 14 disposed in the exhaust gas flow 80 from the internal combustion engine 12 and a compressor 15 disposed in the incoming air flow to the internal combustion engine 12. Turbine 14 and compressor 15 are firmly interconnected to rotate through a shaft in a known manner. The exhaust gas flow 80 is transmitted through the exhaust duct 18. Further, the internal combustion engine 12 includes a gas intake side, where fuel and air are mixed and supplied to the internal combustion engine 12 in a known manner.

Those skilled in the art will appreciate that the exhaust aftertreatment system can include multiple units, even though the exhaust treatment unit 20 is shown as a single unit in the drawing. Preferably, the exhaust aftertreatment system includes at least a particulate filter for removing particulates from the exhaust gas stream 80 entering the atmosphere, the filter being disposed after the selective catalytic reduction unit in the direction of the exhaust gas stream 80. The
The exhaust treatment unit 20 and the heat exchanger 4 can be integrated into a single device. In the case of a single heat exchanger 4 in the exhaust gas stream 80, this is arranged downstream of the exhaust aftertreatment system (20), the exhaust of the internal combustion engine 12 before reaching the exhaust aftertreatment system (20). Not cooled down.

  The thermodynamic engine 1 has at least four stages. In the first stage I, the working fluid of the thermodynamic engine 1 is in the liquid phase upstream of the pump device 2 and has a pressure near atmospheric pressure (ambient air pressure). In the second stage II downstream of the pump device 2, the working fluid is still in its liquid phase, but is pressurized to a predetermined pressure by the pump device 2. In the stage III downstream (rear stage) of the heat exchanger 4, the working fluid moves to the gas phase and is pressurized to a predetermined pressure higher than the atmospheric pressure. In the fourth stage downstream of the expander device 8, the working fluid is still in its gas phase but has a pressure of atmospheric pressure.

Thus, the cycle can be split on different sides (see also Table 1). A low pressure side (stage II and stage III) downstream of the expander apparatus 8 and upstream of the pump apparatus 2, and a high pressure side (stage I and stage) downstream of the pump apparatus 2 and upstream of the expander apparatus 8 IV) or the low temperature side (stage I and stage II) downstream of the condenser 10 and upstream of the heat exchanger 4 and the high temperature side downstream of the heat exchanger 4 and upstream of the condenser 10 (Stage III and Step IV).

Hereinafter, the operation principle of the thermodynamic engine 1 will be described. In the first stage I, a low-temperature liquid-phase working fluid flows into the pump device 2, where the low-temperature liquid-phase working fluid is pressurized to a predetermined pressure higher than atmospheric pressure. Subsequently, the pressurized liquid phase working fluid is transmitted to the heat exchanger 4, and the heat exchanger 4 is heated and converted from the liquid phase to the gas phase. The pressure can be increased once again for conversion to the gas phase. The pressurized gas-phase working fluid then flows to the expander device 8, where the thermal energy is converted into mechanical or electrical energy. The mechanical energy can be generated, for example, by a displacement engine (not shown) such as a piston engine in which a pressurized working fluid operates the piston, or a turbine (not shown). Alternatively, the expander device 8 may operate a generator (not shown) for generating electrical energy. The pressure of the working fluid is used, for example, to displace the piston or operate the turbine or generator.
As a result, the pressure of the working fluid is reduced, and in the fourth stage IV, the working fluid is still in the gas phase but has a low pressure. Subsequently, the low pressure gas phase working fluid is transported to the condenser 10 and the hot working fluid is cooled below the dew point and thereby converted back to the liquid phase.

  Such a working fluid for the thermodynamic engine 1 can be a pure liquid, for example water or a mixture of water, and a first additional component, for example ammonia or ethanol. If additional components influence the thermodynamic phase transition point of the working fluid, as in the case of ammonia / water mixtures and / or ethanol / water mixtures, the first additional component is advantageously used, for example using water. It fulfills the function of preventing working fluid from freezing.

  As described above, the concentration of the antifreeze component can be adjusted, and the gas pressure in the gas phase of the thermodynamic engine 1, typically in stage III of the thermodynamic engine 1, can be adjusted. It is advantageous.

This has been achieved in accordance with the present invention, and with further reference to FIG. 3, a first container, shown as working fluid storage tank 40, is fluidly connected to provide a volume of working fluid (eg, It is a mixture of the first basic component and the first additional component) or only a certain amount of the first additional component, for example ethanol or ammonia.
As described above, the working fluid storage tank 40 is fluidly connected to the high pressure side of the working fluid circulation circuit 11, ie, stage III.
More specifically, the working fluid storage tank 40 is connected to the working fluid circulation circuit 11 upstream of the expander device 8 downstream of the heating device (4). The exhaust gas system 100 includes a working fluid storage tank valve 42 configured to control the working fluid flow between the working fluid storage tank 40 and the working fluid circulation circuit 11. The exhaust gas system 100 further includes a working fluid storage tank conduit 44 that fluidly connects the working fluid storage tank 40 with the working fluid circulation circuit 11. A valve 42 of the working fluid storage tank is disposed in the conduit 44.

  The working fluid storage tank 40 may be pressurized to a pressure higher than that present on the high pressure side III, or ammonia may be transported to the working fluid circulation circuit 11 by a pump (not shown).

  As mentioned above, air leakage is one of the main drawbacks of known thermodynamic engines, in addition to freezing. In particular, during shutdown, the high pressure side III can be cooled to such an extent that the pressure drops below atmospheric pressure. As a result, air leaks into the working fluid circulation circuit 11, which reduces the efficiency of the thermodynamic engine 1. In addition, air, especially in the form of bubbles or cavities, can be quite aggressive against the constituent materials of thermodynamic engine components.

  A valve 42 located in the conduit 44 between the working fluid storage tank 40 and the working fluid circulation circuit 11 was detected when the problem of air leakage occurred only during cooling and the pressure dropped below ambient pressure. Depending on the pressure drop or engine operating conditions, it is opened and additional ammonia can flow into the working fluid circulation circuit 11. Thereby, as described above, the pressure in the working fluid circulation circuit 11 can be increased to the level of atmospheric pressure, and air is prevented from leaking.

  In addition to the above discussion, it is possible to prevent the leakage of air by overflowing the working fluid circulation circuit 11 with the working fluid by providing the working fluid storage tank 40. The concentration can be adapted to the local climate and / or the sensed ambient temperature. Advantageously, at low temperatures, high ammonia concentrations can be used as freeze protection, the amount of ammonia during low temperatures, i.e. in winter, can be increased, and the condenser can operate at high temperatures.

  Preferably, the ammonia concentration can be adapted to daily, weekly and / or monthly criteria depending on the expected temperature change. Of course, it is also possible to adapt the ammonia concentration on a shorter or longer time scale.

  The working fluid storage tank 40 is used, for example, when the pressure in the working fluid circulation circuit 11 exceeds a predetermined pressure threshold, and may be configured to receive an excess amount of working fluid in the working fluid circulation circuit 11. Such operating conditions of the truck 500 include, for example, starting the thermodynamic engine 1, where excess working fluid can be received again by the working fluid storage tank 40. In order to achieve such functionality, the above-described pump (not shown) can be used in the reverse manner, ie to transport the working fluid from the working fluid circulation circuit 11 to the working fluid storage tank 40. It can be. It may also be possible to regulate the temperature surrounding the working fluid storage tank 40, ie to cool the working fluid storage tank 40 so that only the pump is an optional component of the system 100.

  If it is desirable to reduce the pressure in the working fluid circulation circuit 11, for example for maintenance purposes in the event of a collision or maintenance of the thermodynamic engine 1, and / or for the purpose of maintenance of the truck 500, further An operating condition exists.

Reference is now made to FIG. 4 which shows a further development of the embodiment of FIG. The exhaust gas system 100 includes first and second additional second vessels implemented as a working fluid storage tank 40 and an additional working fluid storage tank 50, which are on the high pressure side of the working fluid circulation circuit 11. That is, it is fluidly connected to stage III.
The additional working fluid storage tank 50 forms a collector in this embodiment, so that the release of ammonia from the working fluid circulation circuit 11 to the working fluid storage tank 50 is the same way but the working fluid storage. It works in contrast to the general functionality of the tank 40. A controllable valve 52 is arranged in the connection duct 54 between the working fluid storage tank 50 and the working fluid circulation circuit 11.
Thus, the working fluid storage tank 40 is used to increase the pressure in the working fluid circulation circuit 11, and the working fluid storage tank 50 is used to decrease the pressure in the working fluid circulation circuit 11. . It may be possible to include an additional pump (not shown) with the working fluid storage tank 50. However, the working fluid storage tank 50 is cooled or kept cool so that a pressure difference between the working fluid circulation circuit 11 and the working fluid storage tank 50 is provided, i.e., to make the pump optional. May be.

Reference is now made to FIG. 5, which shows a further development of the embodiment of FIGS. Instead of using a working fluid storage tank 50 to reduce the amount of working fluid in the working fluid circulation circuit 11, the working fluid discharge includes a controllable valve 26 located on the high pressure side III of the working fluid circulation circuit 11. It may be possible to branch the working fluid circulation circuit 11 using means 24.
Accordingly, the working fluid, for example, ammonia, can be released from the working fluid circulation circuit 11 to the catalyst processing unit 20 in the exhaust aftertreatment system for catalytic treatment of the released working fluid. Thereby, the working fluid discharge means 24 may serve as a safe discharge of the working fluid or in general as a discharge possibility in a manner similar to that described above. However, as shown in FIG. 5, both the working fluid storage tank 50 and the working fluid discharge means 24 can be included in the system 100 (ie, further in the first working fluid storage tank 40). It should be noted that you get.
That is, the working fluid storage tank 50 and the working fluid discharge means 24 can be individually controlled according to different operating conditions of the truck 500, for example. In any case, the released working fluid can be used without being released to the atmosphere.

The catalyst component of the SCR temporarily stored significant amounts of ammonia, followed by it to use in _the NO _x reduction step, i.e. it should not be released directly into the atmosphere is enhanced. In general, the SCR will supply an additional source of ammonia, such as from a storage tank 502.

  It is advantageous to branch off the working fluid discharge means 24 upstream of the expander device 8 and downstream of the heat exchanger 4, and the highest pressure is expected. Since the pressure on the high pressure side is usually higher than the pressure in the exhaust duct 18, no further means for propelling the flow of working fluid into the exhaust duct 18 is necessary.

  The released working fluid or a portion of the released working fluid is then catalytically processed in the exhaust aftertreatment unit 20 and thereby converted into harmless compounds that can be released to the atmosphere. It should be noted that the location where a portion of the working fluid is thereby discharged to the exhaust aftertreatment system depends on the type of working fluid. For example, when ammonia is used, it is preferable to introduce discharged working fluid into the exhaust aftertreatment system upstream of the selective catalytic reduction unit. When alcohol is included in the working fluid, it is advantageous to release the working fluid into the exhaust aftertreatment system upstream of the oxidation catalyst.

  Dividing the working fluid discharge means 24 on the hot and high pressure side of the working fluid circulation circuit 11 has the further advantage that the exhaust flowing through the exhaust duct 18 is not excessively cooled, so that after exhaust The operating temperature of the processing system is not impaired. Typically, the operating temperature of an exhaust aftertreatment system is 250 degrees Celsius or higher.

Finally, reference is made to FIG. 6 which shows an additional further embodiment of FIGS. The exhaust gas system 100 includes a control unit 110 for implementing a control method as described above, and is operatively connected to the valves 42, 52 and 26 that are controllable to open and / or close the valves 42, 52 and 26. It is connected to the. The exhaust gas system 100 includes at least one pressure detector 102 disposed in the working fluid circulation circuit 11. Furthermore, the control unit 110 is operatively connected to a pressure detector 102 for controlling the opening and / or closing of the valves 42, 52 and 26 in response to the detected pressure.
More specifically, the pressure detector 102 is arranged on the high pressure side of the working fluid circulation circuit 11, that is, on the stage III. The control unit 110 is configured to control the valves 42, 52 and 26 in response to different operating conditions of the track 500 in the manner described above. Further, the exhaust gas system 100 includes manually operable means 106 connected to the control unit 110 for manually controlling the opening and / or closing of the valves 42, 52 and 26.

  Although the drawings may show a specific order of method steps, the order of steps may differ from that shown. Two or more steps may be executed in parallel, or may be partially executed simultaneously. Such changes depend on the selection software and hardware system and the designer's choice. All such variations are within the scope of this disclosure. Similarly, software embodiments can be achieved by standard programming techniques with rule-based logic and other logic to achieve various connection steps, processing steps, comparison steps, and decision steps. In addition, although the present invention has been described with reference to particular exemplary embodiments, many different changes, modifications, etc. will be apparent to those skilled in the art.

  Variations to the disclosed embodiments can be understood and attained by those skilled in the art in practicing the claimed invention, from a study of the drawings, the disclosure, and the appended claims. Further, in the claims, the word “comprising” does not exclude other elements or steps, and the indefinite article “a” or “an” does not exclude a plurality.

Disadvantageously, ammonia is corrosive and harmful. Therefore, ammonia must be handled with great care and must not be released to the environment. However, such emissions can occur, for example, in the event of an accident involving a thermodynamic engine or a vehicle containing such an engine (eg, a collision of a vehicle with another vehicle) or maintenance of a thermodynamic engine and / or vehicle. Inevitable inside. In the past, expander device bypasses have been used to release working fluid pressure and provide the possibility of safe maintenance. Disadvantageously, this procedure is very time consuming, the vehicle stationary time in the workplace is unnecessarily long, and / or the waiting time for the rescue team to access the vehicle safely is unacceptable, for example. It becomes long to the extent.
Additional attention is paid to US 2013/327041 regarding the use of waste heat in internal combustion engines, particularly motor vehicles with waste heat utilization circuits. The working medium is circulated in the waste heat utilization circuit by a pump device provided to pressurize the working medium. The waste heat utilization circuit is in communication with a pressure reservoir that can maintain pressure to set and ensure a predetermined minimum adjustable pressure of the working medium in the waste heat utilization circuit.

Claims (15)

A mechanism (17) for transmitting the exhaust gas flow (80);
A heat exchanger (4) disposed within the exhaust gas stream (80) to recover heat from the exhaust gas stream (80) and a first base mixed with a first additional component at a selected concentration A thermodynamic engine (1) including a working fluid circulation circuit (11) holding a working fluid containing components;
A vehicle (500) for storing a quantity of at least the first additional component of the working fluid, the first container (40) fluidly connected to the working fluid circulation circuit (11); In the exhaust gas system (100),
The first container (40) is connected downstream of the heat exchanger (4) in a gas phase in the working fluid circulation circuit (11), and further, the first container (40) in the working fluid circulation circuit (11). The pressure of the working fluid in the gas phase is configured to be adapted to one of a plurality of predetermined conditions, the plurality of predetermined conditions depending on different operating conditions of the vehicle (500);
An exhaust gas system (100) characterized by that.   The gas phase in the working fluid circuit (11) further includes a pressure detector (102) disposed downstream of the heat exchanger (4), and the air in the working fluid circuit (11). The exhaust gas system (100) of claim 1, wherein the adjustment of the pressure of the working fluid in phase depends on the pressure detected by the pressure detector (102).   The pressure of the working fluid in the gas phase in the working fluid circulation circuit (11) adjusts the selected concentration of the first additional component relative to the first basic component. The exhaust gas system (100) according to claim 1 or 2, wherein the exhaust gas system (100) is adjusted.   4. The method according to claim 1, wherein the selected concentration of the first additional component relative to the first basic component is adjusted based on an ambient temperature detected by a temperature sensor. The described exhaust gas system (100). A second vessel (50) fluidly connected to the working fluid circulation circuit (11) in the gas phase in the working fluid circulation circuit (11);
The first container (40) is configured to allow an increase in the pressure under one of the predetermined conditions, and the second container (50) is configured with another of the predetermined conditions. The exhaust gas system (100) according to any of the preceding claims, wherein the exhaust gas system (100) is configured to reduce the pressure by one.   A working fluid discharge means (24) and an exhaust treatment unit (20) are further included. The working fluid discharge means (24) is disposed between the working fluid circulation circuit (11) and the exhaust treatment unit (20). Wherein the first vessel (40) is configured to allow the increase in pressure under one of the predetermined conditions, and the exhaust treatment unit (20 6) in combination with the working fluid discharge means (24), configured to reduce the pressure at another one of the predetermined conditions. An exhaust gas system (100) according to claim 1.   The exhaust gas system (100) of claim 6, wherein the exhaust treatment unit (20) is formed by a selective catalytic reduction unit (SCR).   The exhaust according to claim 6 or 7, wherein the working fluid discharge means (24) is connected downstream of the heat exchanger (4) in the gas phase in the working fluid circulation circuit (11). Gas system (100).   The exhaust gas system (100) according to any one of claims 1 to 8, wherein the first additional component is at least one of ammonia and alcohol.   The exhaust according to claim 9, wherein at least one of the first container (40) and the second container (50) is configured to store liquid ammonia and / or ammonia adsorbing material. Gas system (100).   At least one controllable valve (26, 42, 54) further comprising a control unit (110) electrically connected to the pressure detector (102) and operatively connected to the control unit (110). The exhaust gas system (100) according to claim 2, wherein the exhaust gas system (100) is configured to regulate the pressure of the working fluid in the gas phase of the working fluid circulation circuit (11). A method for controlling an exhaust gas system (100) for a vehicle (500) comprising:
A mechanism (17) for transmitting an exhaust gas stream (80), a heat exchanger (4) disposed in the exhaust gas stream (80) for recovering heat from the exhaust gas stream (80) and a concentration A thermodynamic engine (1) that includes a working fluid circulation circuit (11) that retains a working fluid containing a first basic component mixed with a first additional component; and at least the first additional component of the working fluid A first container (40) for storing a quantity of the first container, wherein the first container is fluidly connected to the working fluid circuit.
Detecting the pressure of the working fluid in the gas phase in the working fluid circulation circuit (11);
Adjusting the pressure to meet one of a plurality of predetermined conditions that depend on different operating conditions of the vehicle (500);
A method comprising the steps of: Further comprising fluidly connecting a working fluid discharge means (24) between the working fluid circulation circuit (11) and an exhaust treatment unit (20) provided in the vehicle (500);
The first container (40) is configured to allow the pressure to increase under one of the predetermined conditions, and the exhaust treatment unit (20) includes a discharge means (24) for the working fluid. The method of claim 12, configured in combination to reduce the pressure at another one of the predetermined conditions. Determining a current operating condition of the vehicle (500);
In the gas phase in the working fluid circulation circuit (11), at least one controllable valve depending on the determined current operating condition of the vehicle (500) to adjust the pressure of the working fluid in the gas phase Controlling (26, 42, 54);
The method according to claim 12 or 13, further comprising:   A computer program product comprising a computer readable medium having stored thereon computer program means for controlling an exhaust gas system (100) for a vehicle (500), the computer program comprising code for performing the steps of claim 12 Product.