Patent Publication Number: US-2022220877-A1

Title: Systems and methods for heating an aftertreatment system

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims priority to U.S. patent application Ser. No. 16/915,211, filed Jun. 29, 2020, the complete disclosure of which is incorporated herein by reference in its entirety. 
     TECHNICAL FIELD OF THE DISCLOSURE 
     The present disclosure relates to systems and methods for heating an aftertreatment system, and specifically to systems and methods for heating ail aftertreatment system while the engine is not running or by circumventing the engine while it is running. 
     BACKGROUND OF THE DISCLOSURE 
     In engine systems with internal combustion engines and aftertreatment systems, the aftertreatment systems must be warm for emissions to be treated or converted. However, current systems are unable to warm up aftertreatment systems without the engine running such that fuel is burned and emissions are created while the aftertreatment system is not at a sufficient temperature. This results in a period of emissions that cannot be treated prior to leaving the engine system. Thus, a system and method for heating an aftertreatment system while the engine is not running or by circumventing the engine when it is running to heat up the aftertreatment system faster is needed. 
     SUMMARY OF THE DISCLOSURE 
     In one embodiment of the present disclosure, a method for warming an aftertreatment system of an engine system while an engine of the engine system is not running is provided. The method comprises starting the electric compressor using stored electrical energy and passing air through an exhaust gas recirculation system of the engine system to at least a portion of the aftertreatment system, wherein the air is passed in a direction opposite to a direction of exhaust flow through the exhaust gas recirculation system when the engine of the engine system is running. 
     In another embodiment of the present disclosure, a method for warming an aftertreatment system of an engine system while an engine of the engine system is not running, where the engine system includes at least one of an electric compressor and an electric heater is provided. The method includes starting the at least one of the electric compressor and the electric heater using stored electrical energy and passing air to at least a portion of the aftertreatment system through an engine bypass channel when the engine is not running. 
     In a further embodiment of the present disclosure, a method for warming an aftertreatment system of an engine system while an engine of the engine system is not running, where the engine system includes at least one of an electric compressor and an electric heater is provided. The method comprises starting the at least one of the electric compressor and the electric heater using stored electrical energy and passing air to at least a portion of the aftertreatment system through at least one valve of at least one cylinder of the engine when the engine is not running. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Advantages and features of the embodiments of this disclosure will become more apparent from the following detailed description of exemplary embodiments when viewed in conjunction with the accompanying drawings, wherein: 
         FIG. 1  shows a schematic diagram of a first embodiment of an engine system of the present disclosure configured to heat an aftertreatment system of the engine system when the engine is not running; 
         FIG. 2  shows a schematic diagram of a second embodiment of an engine system of the present disclosure configured to heat an aftertreatment system of the engine system when the engine is not running; and 
         FIG. 3  shows a schematic diagram of a third embodiment of an engine system of the present disclosure configured to heat an aftertreatment system of the engine system when the engine is not running. 
     
    
    
     Corresponding reference characters indicate corresponding parts throughout the several views. Although the drawings represent embodiments of the present disclosure, the drawings are not necessarily to scale and certain features may be exaggerated in order to better illustrate and explain the present disclosure. The exemplifications set out herein illustrate embodiments of the disclosure, in one form, and such exemplifications are not to be construed as limiting the scope of the disclosure in any manner. 
     DETAILED DESCRIPTION OF THE DRAWINGS 
     Referring now to  FIGS. 1-3 , a schematic diagram of an engine system  100  is shown. Engine system  100  generally comprises an engine  10 , which includes an intake  12  and an exhaust  14 , and an aftertreatment system  30 , which may comprise a diesel oxidation catalyst (DOC)  32 , a diesel particulate filter (DPF)  34 , and/or a selective catalytic reduction (SCR) system  36 . Engine system  100  may further include a turbocharger  16  having a compressor  18  and a turbine  20 , an electric compressor  37 , and/or an electric heater  38 . For example, engine system  100  may include each of turbocharger  16 , electric compressor  37 , and electric heater  38 , while in other various embodiments, engine system  100  may only include turbocharger  16  and electric heater  38  or compressor  37  and electric heater  38  or compressor  37  or turbocharger  16  alone. In various embodiments, turbocharger  16  is an electric turbocharger including a motor  17 , and compressor  18  is an electric compressor. Motor  17  of electric turbocharger  17  may be coupled between compressor  18  and turbine  20  ( FIG. 1 ) or to compressor  18  alone ( FIG. 2 ). Motor  17  of electric turbocharger  16  (and therefore compressor  18  and/or turbine  20 ), electric compressor  37 , and/or electric heater  38  may run off stored electrical energy from an electrical system containing a battery (not shown) while engine  10  is not running. Turbocharger  16  and/or electric compressor  37  are generally configured to move air through engine system  100  when engine  10  is not running, while heater  38  is configured to heat air passed through heater  38 . 
     Furthermore, in various embodiments, SCR system  36  is coupled to an injector  40  configured to provide diesel exhaust fluid (DEF), ammonia (NH 3 ), or another reactant to SCR system  36 . Injector  40  may be controlled such that SCR system  36  is preloaded with DEF, NH 3 , or another reactant while engine  10  is not running. 
     Engine system  100  generally also includes an engine control module (ECM) (not shown) that is configured to control the various components of engine system  100 . For instance, the ECM may be configured to understand a need for engine  10  to be started up, to determine a temperature of aftertreatment system  30 , to determine an amount of electrical energy available to run the various components of system  100  such as turbocharger  16 , electric heater  38  and/or injector  40 , and to determine when the various components of system  100  such as turbocharger  16 , electric heater  38 , and/or injector  40  should be turned on, to properly heat aftertreatment system  30  prior to igniting engine  10 . The ECM may further be configured to determine when to open the cylinder valves or other valves of system  100  described further below for driving air through the cylinders or other component of system  100  or when to stop engine  10  such that the valves of the cylinders overlap. 
     With reference to  FIG. 1 , a first embodiment 100a of engine system  100  is shown that is configured to heat aftertreatment system  30  while engine  10  is not running. Engine system  100   a  allows air to enter through compressor  18  of turbocharger  16  and/or electric compressor  37 , and to flow through cylinders of engine  10  while engine  10  is not running such that the air can flow to aftertreatment system  30 . In various embodiments, air may flow through the cylinder(s) of engine  10  by controlling the valves of the cylinder(s) via the ECM to overlap when engine  10  is shut down previously. In other various embodiments, engine system  100   a  may further include a variable valve system  42  configured to open the valve(s) of the cylinder(s) to allow air through. Variable valve system  42  may include an oil accumulator or a piezo system to allow the valves to be opened while engine  10  is not running. In various embodiments, once air passes through the cylinder(s) of engine  10 , this air may flow through turbine  20  of turbocharger  16  and then to aftertreatment system  30 , or flow around or bypass turbine  20  of turbocharger  16  via bypass channel  44  and go directly to aftertreatment system  30 . 
     Referring now to  FIG. 2 , a second embodiment 100b of engine system  100  is shown that is configured to heat aftertreatment system  30  while engine  10  is not running or while engine  10  is running off of electrical energy prior to burning any fuel. Engine system  100   b  includes an engine bypass  50  configured to allow air received from compressor  18  of turbocharger  16  and/or electric compressor  37  to route past engine  10  and either flow through turbine  20  of turbocharger  16  or bypass turbocharger  16  via bypass channel  44  and flow to aftertreatment system  30 . 
     With reference now to  FIG. 3 , a third embodiment 100c of engine system  100  is shown that is configured to heat aftertreatment system  30  while engine  10  is not running. Engine system  100   c  further includes an exhaust gas recirculation (EGR) system  22  having an EGR valve  24  and an EGR cooler  26 . In various embodiments, EGR valve  24  may be upstream of EGR cooler  26 , while in other various embodiments, EGR valve  24  may be downstream of EGR cooler  26 . Engine system  100   c  is configured to route air backwards through EGR system  22  such that the air received from compressor  18  of turbocharger  16  and/or electric compressor  37  bypasses engine  10  and either flows through turbine  20  of turbocharger  16  or bypasses turbocharger  16  and flows to aftertreatment system  30 . In other words, engine system  100   c  routes air through EGR system  22  in a direction opposite to the direction of exhaust flow through EGR system  22  when engine  10  is running. 
     When turbine  20  is bypassed via bypass channel  44  or air flows from engine bypass  50  to aftertreatment system  30  bypassing turbocharger  16 , this air may flow to a position upstream of DOC  32 , DPF  34  and/or SRC system  36  or to a position downstream of DOC  32 , and DPF  34  just upstream of or directly to SRC system  36 , or to any position therebetween. Heater  38  may be positioned at any position within engine system  100 . For example, heater  38  may be positioned upstream of DOC  32 , DPF  34 , and SRC system  36 , or heater  38  may be positioned downstream of DOC  32  and DPF  34  and upstream of SRC system  36 . Bypass channel  44  may include a valve  52  configured to direct air to the various positions of aftertreatment system  30 . 
     In various embodiments, engine system  100  may further include an electric motor (not shown) such that engine system  100  is a hybrid system. The electric motor may provide mechanical power to or absorb mechanical power from engine  10  in exchange for using or providing electrical energy to the electrical system of engine system  100 , which may be configured to run compressor  18  and/or turbine  20  of turbocharger  16 , compressor  37 , heater  38 , and/or other various components of engine system  100  off of stored electrical energy. For instance, electric energy provided to the electrical system of engine system  100  from the electric motor may run motor  17  of turbocharger  16 , compressor  37 , and/or heater  38  such that aftertreatment system  30  may be warmed up prior to any fuel being burned through the running of engine  10  from power produced by a fuel. 
     While various embodiments of the disclosure have been shown and described, it is understood that these embodiments are not limited thereto. The embodiments may be changed, modified and further applied by those skilled in the art. Therefore, these embodiments are not limited to the detail shown and described previously, but also include all such changes and modifications. 
     Furthermore, the connecting lines shown in the various figures contained herein are intended to represent exemplary functional relationships and/or physical couplings between the various elements. It, should be noted that, many alternative or additional functional relationships or physical connections may be present in a practical system. However, the benefits, advantages, solutions to problems, and any elements that may cause any benefit, advantage, or solution to occur or become more pronounced are not to be construed as critical, required, or essential features or elements. The scope is accordingly to be limited by nothing other than the appended claims, in which reference to an element in the singular is not intended to mean “one and only one” unless explicitly so stated, but rather “one or more.” Moreover, where a phrase similar to “at least one of A, B, or C” is used in the claims, it is intended that the phrase be interpreted to mean that A alone may be present in an embodiment, B alone may be present in an embodiment, C alone may be present in an embodiment, or that any combination of the elements A, B or C may be present in a single embodiment; for example, A and B, A and C, B and C, or A and B and C. 
     In the detailed description herein, references to “one embodiment,” “an embodiment,” “an example embodiment,” etc., indicate that the embodiment described may include a particular feature, structure, or characteristic, but every embodiment may not necessarily include the particular feature, structure, or characteristic. Moreover, such phrases are not necessarily referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with an embodiment, it is submitted that it is within the knowledge of one skilled in the art with the benefit of the present disclosure to affect such feature, structure, or characteristic in connection with other embodiments whether or not explicitly described. After reading the description, it will be apparent to one skilled in the relevant art(s) how to implement the disclosure in alternative embodiments. 
     Furthermore, no element, component, or method step in the present disclosure is intended to be dedicated to the public regardless of whether the element, component, or method step is explicitly recited in the claims. No claim element herein is to be construed under the provisions of 35 U.S.C. § 112(f), unless the element is expressly recited using the phrase “means for.” As used herein, the terms “comprises,” “comprising,” or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus.