Patent Publication Number: US-2019178149-A1

Title: Energy supercharger system and method

Description:
TECHNICAL FIELD 
     The present disclosure generally relates to a supercharger system and a method for operating an internal combustion engine. More particularly, the present disclosure relates to a supercharger system and a method for improved engine transient response. 
     BACKGROUND 
     Generally, a turbocharger is employed on an engine for increasing a pressure of intake air (boost) entering combustion chambers of the engine. The turbocharger may be typically driven by a stream of exhaust gases exiting the combustion chambers of the engine. When the engine is operating on a low load, the turbocharger may not be able to provide a desired pressure to the intake air to meet any sudden load applied on the engine. 
     In some applications, the engine may be used to drive an electrical generator. When a sudden electrical load is applied on the generator, the engine may be required to quickly ramp up a speed of the engine, so that the generator output meets a minimum frequency and′ voltage requirements associated with the electrical load. However, the turbocharger associated with the engine may not be able to provide enough pressure to the intake air for combustion of a required amount of fuel to quickly increase the speed of the engine. 
     U.S. Pat. No. 9,228,487 (hereinafter referred to as “the &#39;487 patent”) describes an engine having a turbocharger and a supercharger. The &#39;487 patent discloses that compressed air from the supercharger is being fed to a suction side (i.e. air inlet side) of a compressor associated with the turbocharger in order to meet a sudden increase in load demand on the engine. However, in this kind of arrangement, for the supercharger to provide a boost pressure equivalent to that of the turbocharger running at high speeds may require higher capacity superchargers, requiring larger space and higher cost. 
     SUMMARY OF THE DISCLOSURE 
     In one aspect of the present disclosure, a supercharger system for an engine having a turbocharger is provided. The supercharger system includes a supercharger driver and an air inlet. The supercharger system also includes a supercharger compressor mechanically coupled to the supercharger driver. The supercharger compressor includes a supercharger compressor inlet and a supercharger compressor outlet. The supercharger compressor inlet is in fluid communication with the air inlet. The supercharger compressor outlet is in fluid communication with a turbocharger turbine inlet. 
     In another aspect of the present disclosure, an engine is provided. The engine includes a plurality of combustion chambers. Each of the plurality of combustion chambers is in fluid communication with an air intake manifold and an exhaust manifold of the engine. The engine also includes a turbocharger having a turbocharger turbine. The turbocharger turbine includes a turbocharger turbine inlet in fluid communication with the exhaust manifold of the engine. The engine further includes a supercharger system. The supercharger system includes a supercharger driver and an air inlet. The supercharger system also includes a supercharger compressor mechanically coupled to the supercharger driver. The supercharger compressor includes a supercharger compressor inlet and a supercharger compressor outlet. The supercharger compressor inlet is in fluid communication with the air inlet. The supercharger compressor outlet is in fluid communication with the turbocharger turbine inlet. 
     A method is provided for operating an engine having a turbocharger and a supercharger and the engine is coupled to a generator. The method includes determining, by means of a controller, whether an intake air pressure or intake air flow rate of an air intake manifold is below a threshold, when the engine is running at low load. The method includes driving a supercharger compressor. The method includes receiving a flow of ambient air into the supercharger compressor. The method further includes pressurizing the received ambient air by the supercharger compressor. The method further includes providing pressurized air from the supercharger compressor to an exhaust manifold of the engine to provide a flow of pressurized air to turbocharger turbine inlet. The method further includes sensing, by means of a controller, a sudden additional load on the engine. The method includes increasing an amount of fuel into a plurality of the combustion chambers of the engine. 
     Other features and aspects of this disclosure will be apparent from the following description and the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The features and advantages of the present disclosure will become more apparent from the detailed description set forth below when taken in conjunction with the drawings. 
         FIG. 1  is a schematic illustration of an engine having a turbocharger and a supercharger system, according to an aspect of the present disclosure; and 
         FIG. 2  is a flowchart depicting a method for operating the supercharger system of the engine, according to an aspect of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     Wherever possible, the same reference numbers will be used throughout the drawings to refer to same or like parts.  FIG. 1  illustrates an engine  102  according to an embodiment of the present disclosure. As shown, the engine  102  includes multiple combustion chambers  104 . In the illustrated embodiment of  FIG. 1 , the engine  102  has four combustion chambers  104 . However, in other embodiments, the engine  102  may be configured to include fewer or more combustion chambers  104 . 
     As shown in  FIG. 1 , the engine  102  may be provided with an air intake manifold  106  being in fluid communication with each of the combustion chambers  104  by a supply tube  108  corresponding to each of the combustion chambers  104 . The air intake manifold  106  may be configured to receive a supply of air or a premixed charge that may be operatively supplied to each of the combustion chambers  104  via the corresponding supply tube  108 . The engine  102  may also be provided with an exhaust manifold  110  being in fluid communication with the combustion chambers  104  by an exhaust tube  112  corresponding to each of the combustion chambers  104 . The exhaust manifold  110  may be configured to receive a stream of exhaust gases from each of the combustion chambers  104  via the corresponding exhaust tube  112 . 
     The engine  102  further includes a turbocharger  114  that is fluidly coupled to the engine  102 . The turbocharger  114  includes a turbocharger turbine  116  and a turbocharger compressor  118  mechanically coupled to the turbocharger turbine  116  through a connecting shaft  120 . The turbocharger turbine  116  includes a turbocharger turbine inlet  122  and a turbocharger turbine outlet  124 . The turbocharger turbine inlet  122  is in fluid communication with the exhaust manifold  110  of the engine  102  via an exhaust inlet line  121 . The turbocharger turbine outlet  124  may be fluidly coupled with an exhaust outlet line  126 , which may direct exhaust gases to an aftertreatment module, muffler exhaust stack, or other components (not shown). Further, in an embodiment, the engine  102  may include multiple turbochargers such as turbochargers  114 . Also, the exhaust manifold  110  may be divided into multiple sections (not shown), fluidly coupled with the turbocharger turbine inlet  122 . 
     The turbocharger compressor  118  includes a turbocharger compressor inlet  128  and a turbocharger compressor outlet  130 . The turbocharger compressor inlet  128  is fluidly coupled to an air intake line  132  (hereinafter referred to as “the first air intake line”). The first air intake line  132  is configured to receive a flow of ambient air from an air inlet  133  in fluid communication with an ambient air source. As shown in the illustrated embodiment of  FIG. 1 , a first filter  134  may be placed in the first air intake line  132  to filter contaminants, such as particulates, from the ambient air before it flows into the turbocharger compressor  118 . 
     Further as shown in the illustrated embodiment of  FIG. 1 , the turbocharger compressor outlet  130  is fluidly coupled to the air intake manifold  106  via an outlet line  136 . In an embodiment, the engine  102  may also be associated with other components including, but not limited to, an aftercooler, a gas admission valve, or an air throttle valve that may be in fluid communication with the outlet line  136 . 
     The engine  102  may also include a supercharger system  138 . The supercharger system  138  includes a supercharger driver  140 , and a supercharger compressor  144  mechanically coupled to the supercharger driver  140 . In the illustrated embodiment of  FIG. 1 , the supercharger driver  140  may be driven by any auxiliary power source including, but not limited to, an electric motor or a hydraulic motor. In another embodiment, the supercharger driver  140  may include a mechanical coupling  141  (shown in dotted line in  FIG. 1 ) between an engine output and the supercharger compressor  144 , such as a belt drive system, a chain drive system or a gear drive system. 
     The supercharger compressor  144  includes a supercharger compressor inlet  146  and a supercharger compressor outlet  148 . The supercharger compressor inlet  146  is in fluid communication with an air inlet  142  of the supercharger system  138 . As shown in the illustrated embodiment of  FIG. 1 , the supercharger compressor inlet  146  may be in fluid communication with the air inlet  142  in fluid communication with an ambient air source via an air intake line  150  (hereinafter referred to as “the second air intake line”). The supercharger system  138  may also include a second air filter  149  in fluid communication with the second air intake line  150  and located between the air inlet  142  and the supercharger compressor inlet  146 . The second air filter  149  filters any contaminants from the ambient air before it flows into the supercharger compressor  144  via the supercharger compressor inlet  146 . Although not shown in  FIG. 1 , it should be apparent that the first air intake line  132  and the second air intake line  150  are in fluid communication with the same ambient air source and may alternatively configured as branches of a single intake air line fluidly coupled to a single air inlet. 
     The supercharger compressor outlet  148  may be in fluid communication with the exhaust manifold  110  of the engine  102 . As shown in the illustrated embodiment of  FIG. 1 , the supercharger compressor outlet  148  may be fluidly coupled to the exhaust manifold  110  of the engine  102  via an outlet line  160 . In an embodiment, in which the exhaust manifold  110  may include multiple sections, the supercharger compressor outlet  148  may be fluidly coupled to any one or more section of the exhaust manifold  110  via the outlet line  160 . Also, as shown in the  FIG. 1 , the exhaust manifold  110  is in fluid communication with the turbocharger turbine inlet  122  via an exhaust inlet line  121 . Thus, the supercharger compressor outlet  148  is in fluid communication with the turbine inlet  122  via the exhaust manifold  110 . 
     In the embodiment shown in  FIG. 1 , the supercharger system  138  may include a shut off valve  156  positioned in the outlet line  160 . The shut off valve  156  may be configured to open based on a pressure of the pressurized air in the outline line  160 . Thus, the shut off valve  156  remains open during an operation of the supercharger system  138  and closes when the supercharger system  138  is not in operation. 
     The engine  102  may be configured to operatively drive a load, for example, an electrical generator  158  as shown in  FIG. 1 . The engine  102  may be mechanically coupled to the generator  158  by an output shaft and may be driven by the engine  102  to convert mechanical energy output from the engine  102  into electrical energy. 
     As shown in the  FIG. 1 , there may be a controller  164  communicably coupled to the engine  102 , the generator  158 , the supercharger driver  140 , the shut off valve  156  and fuel injectors (not shown) for supplying the fuel to each of the combustion chambers  104 . In an embodiment, if the engine  102  is running at low load the controller  164  may determine, by means of one or more sensors (not shown), whether an intake air pressure in the air intake manifold  106 , a flow of intake air in the intake manifold  106 , or a speed of the turbocharger turbine  116  is below a threshold that may not enable the controller  164  to increase an amount of fuel to be supplied to each of the combustion chambers  104  in an event of a sudden increase in the load on the engine  102 . The controller  164  may start an operation of the supercharger system  138  based on the determination that the controller may not sufficiently increase the fuel to the combustion chambers  104  in the event of a transient (i.e. when the engine  102  needs to transition from the low load to meet the sudden increase in the load). 
     During the operation of the supercharger system  138 , the controller  164  may start the supercharger driver  140  to operate the supercharger compressor  144 . The supercharger compressor  144  receives a flow of ambient air from the air inlet  142  and pressurizes the received ambient air. Further, the shut off valve  156  is opened to provide a flow of the pressurized air from the compressor outlet  148  to the exhaust manifold  100  of the engine  102 , so that the flow of the pressurized air could be provided to the turbine inlet  122  associated with the turbocharger  114 . The addition of the compressed air from the supercharger compressor  144  into the exhaust manifold  110  and subsequently to the turbocharger turbine inlet  122  may impart an additional kinetic energy to the turbocharger turbine  116  thereby driving the turbocharger  114  at a speed greater than would be possible without the supercharger  138 . Accordingly, the turbocharger turbine  116  may be able to drive the turbocharger compressor  118  at a greater speed to provide a greater intake air pressure in the air intake manifold  106 . 
     As the supercharger system  138  is in continuous operation when the engine  102  is running at low load, there is sufficient air intake pressure in the air intake manifold  106  so that the controller  164  may increase an amount of fuel to be supplied to each of the combustion chambers  104  in an event of the sudden increase in the load on the engine  102 . This may enable the engine  102  to have a faster response during the transient condition (i.e. when the engine  102  is transitioning from the low load to meet the sudden application of load on the engine  102 ). This sudden additional load may be applied on the engine  102  because of a sudden increase in electrical load on the generator  158 . In an embodiment, the controller  164  increases the amount of fuel to be supplied to increase the speed of the engine  102  so that the generator  158  may respond to produce frequency and voltage associated with the required electrical load. 
     Further, the controller  164  may initiate a transition of operating conditions of the engine  102  to accommodate the sudden increase in the electrical load on the generator  158 . The controller  164  may determine whether the pressure of the air in the air intake manifold  106  is sufficient to burn enough amount of fuel to meet the sudden additional load applied on the engine  102 . The controller  164  may further determine whether the operating conditions of the engine  102  is transitioned to accommodate the sudden increase in the electrical load on the generator  158 . Accordingly, the controller  164  may close the shut-off valve  156  and disable the operation of the supercharger system  138 . 
     The controller  164  may also include various software and/or hardware components that are configured to perform functions consistent with the present disclosure. Moreover, the controller  164  may be a standalone control system or may be configured to cooperate with an existing electronic control module (ECM) (not shown) of a machine, for instance, an engine may be located onboard a vehicle, or an engine generator. Furthermore, it may be noted that the controller  164  may embody a single microprocessor or multiple microprocessors that include components for selectively and independently controlling operation of the supercharger compressor  144  and the shut off valve  156  associated with the supercharger system  138 . 
     INDUSTRIAL APPLICABILITY 
     The supercharger system  138  may be operated when the engine  102  is operating at a low load, at which the turbocharger  114  alone may not be able to provide the desired intake air pressure for combusting an amount of fuel to meet the sudden additional load, if applied, on the engine  102 . The sudden additional load on the engine  102  may be because of a sudden additional electric load on the generator  158  driven by the engine  102 . 
       FIG. 2  shows a flowchart of a method  200  for operating the supercharger system  138  of the engine  102 . As shown, at step  202 , the method  200  includes determining, when the engine  102  is running at a low load, whether an intake air pressure in the air intake manifold  106  or a speed of the turbocharger turbine  116  is below a threshold that may not enable to increase an amount of fuel to be supplied to each of the combustion chambers  104  in an event of a sudden increase in the load on the engine  102 . Based on the determination, at step  204 , the supercharger driver  140  initiates an operation of the supercharger compressor  144 . At step  206 , the supercharger compressor  144  receives a flow of ambient air through the air inlet  142 . At step  208 , the supercharger compressor  144  pressurizes the flow of the received ambient air. At step  210 , the shut off valve  156  is opened and the pressurized air form the supercharger compressor  144  is provided to the turbocharger turbine inlet  122  through the exhaust manifold  110  of the engine  102 . The flow of the pressurized air from the supercharger compressor  144  provided to the turbine inlet  122  may impart an additional kinetic energy to the turbocharger turbine  116  thereby driving the turbocharger  114  at a speed greater than would be possible without the supercharger  138 . Accordingly, the turbocharger turbine  116  may be able to drive the turbocharger compressor  118  at a greater speed to provide a greater intake air pressure in the air intake manifold  106 , and thus an increase in the pressurized air supplied to each of the combustion chambers  104 . 
     At step  212 , the method  200  includes sensing a sudden additional load on the engine  102 . Accordingly, at step  214 , the method  200  includes increasing an amount of fuel to be supplied to each of the combustion chambers  104 , as there is sufficient amount of pressurized air supplied to each of the combustion chambers  104  to combust the increased amount of fuel. In an embodiment, the increase in the amount of fuel supplied is to increase the speed of the engine  102  so that the generator  158  may respond to produce frequency and voltage associated with the required electrical load. Further, upon determining that the engine  102  is transitioned to accommodate the additional load, the shut off valve is closed  156  and the supercharger system  138  operation is disabled. 
     Embodiments of the present disclosure have applicability in preventing the engine  102  from lugging or stalling when a surge in the load demand occurs on the engine  102 , for instance, when the surge occurs in the amount of the electrical load on the generator  158  that is coupled to the engine  102 . Additionally, embodiments of the present disclosure also have applicability for use in continuously developing boost pressure for the intake air at the turbocharger  114  when associated engine  102  is suddenly required to transition from a low load operating condition to a high load operating condition to meet the surge in the load demand. Also, the supercharger system  138  of the present disclosure, provides a simple and compact arrangement resulting in lower space requirement around the engine  102  as compared to usage of storage tanks with the compressed air. 
     While aspects of the present disclosure have been particularly shown and described with reference to the embodiments above, it will be understood by those skilled in the art that various additional embodiments may be contemplated by the modification of the disclosed machines, systems and methods without departing from the spirit and scope of what is disclosed. Such embodiments should be understood to fall within the scope of the present disclosure as determined based upon the claims and any equivalents thereof