Patent Publication Number: US-11639702-B2

Title: Fuel evaporation gas treatment system

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims under 35 U.S.C. § 119(a) the benefit of priority from Korean Patent Application No. 10-2021-0085212, filed on Jun. 30, 2021, the entire contents of which are incorporated herein by reference. 
     TECHNICAL FIELD 
     The present disclosure relates to a fuel evaporation gas treatment system for a vehicle, and more particularly to a fuel evaporation gas treatment system for a vehicle capable of solving problems such as failure to satisfy evaporation gas regulations and generation of a fuel smell due to the inability to purge a fuel evaporation gas when a turbocharger is operated in a vehicle equipped with a turbocharger. 
     BACKGROUND 
     In general, the fuel system for a vehicle includes a fuel tank for storing fuel, a fuel pump module for supplying the fuel stored in the fuel tank to an engine, a fuel filter for removing foreign substances from the fuel supplied to the engine, and a fuel line for transferring fuel, including a fuel supply line and a fuel return line. 
     In addition, the fuel system for a vehicle further includes a fuel evaporation gas treatment system for treating and controlling fuel evaporation gas (HC gas) generated in the fuel tank.  FIG.  1    schematically shows the configuration of a fuel evaporation gas treatment system. In  FIG.  1   , reference numeral ‘ 1 ’ denotes a fuel tank, reference numeral ‘ 2 ’ denotes a fuel pump module installed in the fuel tank  1 , and reference numeral ‘ 3 ’ denotes a filler neck assembly for injecting fuel into the fuel tank. 
     As shown therein, the fuel evaporation gas treatment system includes a canister  10  for adsorbing and collecting a fuel evaporation gas generated in the fuel tank  1 , an air filter  13  for removing foreign substances from the air sucked into the canister  10 , a canister close valve  12  for opening and closing a pipe (an ambient atmosphere line)  11  between the canister  10  and the air filter  13 , and a purge control solenoid valve (PCSV)  15  for opening and closing a pipe (a purge line)  14  between the canister  10  and the engine intake system  4  or adjusting the extent of opening of the pipe. 
     Describing the configuration thereof in more detail, a gas resulting from evaporation of fuel, that is, a fuel evaporation gas including fuel components such as hydrocarbon (HC) and the like, is generated in the fuel tank  1 . Accordingly, in order to prevent air pollution due to the fuel evaporation gas generated in the fuel tank  1 , a canister  10  for collecting and storing the fuel evaporation gas from the fuel tank is installed in the vehicle. 
     The canister  10  is configured such that a case thereof is filled with an adsorbent material capable of adsorbing the fuel evaporation gas moved from the fuel tank  1 , and the adsorbent material that is widely used therefor is activated carbon. The activated carbon functions to adsorb fuel components, that is, hydrocarbons (HC) or the like, in the fuel evaporation gas introduced into the case of the canister  10 . 
     The canister  10  adsorbs the fuel evaporation gas to the adsorbent material in the state in which the engine is stopped. Also, when the engine is run, the canister  10  desorbs the fuel evaporation gas adsorbed to the adsorbent material using the pressure of the air sucked from the outside (ambient atmosphere) to thus supply the desorbed gas together with the air to the engine intake system. 
     The operation of sucking the collected fuel evaporation gas from the canister  10  into the engine is called a purge operation, and the gas that is sucked from the canister into the engine is called purge gas. The purge gas may be a gas in which fuel components such as hydrocarbons (HC) or the like desorbed from the adsorbent material of the canister and air are mixed. 
     The PCSV  15  for controlling a purge operation is installed in the purge line  14 , which is the pipe connecting the canister  10  and the engine intake system  4 . The PCSV  15  is opened upon a purge operation while the engine is running. The fuel evaporation gas generated in the fuel tank  1  is collected in the canister  10 , purged to the engine intake system  4  through the PCSV  15  in an open state while the engine is running, and then burned in the engine. 
     The PCSV  15  is controlled by a control unit (not shown), for example, an engine control unit (ECU). The control unit controls opening or closing of the PCSV  15  (turns on/off the purge operation) or the extent of opening (gas flow rate) of the PCSV depending on the conditions under which the vehicle is being driven in order to control the fuel evaporation gas. 
     More specifically, the canister  10  includes a case filled with an adsorbent material (e.g. activated carbon). The case includes a loading port  10   a  connected to the fuel tank  1  and configured to introduce the fuel evaporation gas from the fuel tank, a purge port  10   b  connected to the engine intake system  4  and configured to supply the fuel evaporation gas to the engine side, and an ambient atmosphere port  10   c  connected to the air filter (canister filter)  13  and configured to suck air from the ambient atmosphere. 
     The loading port  10   a  of the canister  10  is connected to the fuel tank  1  through a loading line  16 , and the purge port  10   b  of the canister is connected to the engine intake system  4  through the purge line  14 . An ambient atmosphere line (vent line)  11 , which is the pipe connected to the air filter  13 , is connected to the ambient atmosphere port  10   c  of the canister. 
     A partition wall (not shown) is provided in the inner space of the case in order to partition a space in which the ambient atmosphere port  10   c  is located from a space in which the purge port  10   b  and the loading port  10   a  are located. Accordingly, while the fuel evaporation gas introduced from the fuel tank  1  through the loading port  10   a  passes along the inner space partitioned by the partition wall, fuel components, that is, hydrocarbons (HC), are adsorbed onto the adsorbent material. 
     Also, when the PCSV  15  is opened by the control unit while the engine is running and the suction pressure, namely the engine negative pressure, acts on the inner space of the canister  10  through the purge port  10   b  from the engine intake system  4 , air is sucked through the air filter  13  and through the ambient atmosphere port  10   c , and the gas desorbed from the adsorbent material by the air is discharged through the purge port  10   b  and sucked into the engine intake system  4 . 
     In this way, for the purge operation in which the fuel component such as hydrocarbon or the like is desorbed from the adsorbent material in the canister  10  and is then sucked into the engine intake system  4 , the engine negative pressure has to act on the canister  10  through the purge line  14  and the purge port  10   b.    
     Meanwhile, even when the vehicle is equipped with the fuel evaporation gas treatment system, a problem in which a fuel smell occurs in the vehicle occurs. Specifically, when the vehicle is stopped, the fuel evaporation gas (HC gas) is released to the outside, so the driver or passenger may detect a fuel smell. Such a fuel smell mainly occurs under hot and high conditions, and in particular, the driver or passenger may easily smell the fuel when the vehicle is stopped. 
     Under hot conditions in which the outdoor temperature is high, the transfer of external heat such as engine heat, exhaust heat, geothermal heat, etc. increases, thereby increasing the internal temperature of the fuel tank, and vapor pressure decreases under high conditions. Accordingly, the amount of fuel evaporation gas (HC) that is generated increases in the fuel tank, and when the amount of fuel evaporation gas that is generated increases, the collection capacity of the canister is exceeded, and thus the fuel evaporation gas may be discharged to the outside. Ultimately, the driver or the passenger may smell the fuel evaporation gas (fuel smell) released to the outside when the vehicle is stopped. 
     Moreover, in a vehicle equipped with a turbocharger, when the turbocharger is operated (supercharged), positive pressure, rather than negative pressure, is formed in the engine intake system, so the suction of fuel evaporation gas by the negative pressure does not occur, making it impossible to purge the fuel evaporation gas collected in the canister. As described above, when the fuel evaporation gas is not consumed in the engine due to impossibility of purging, the amount of the fuel evaporation gas present in the fuel tank may increase, and the likelihood of the amount of the fuel evaporation gas exceeding the collection capacity in the canister may increase. 
     Hence, the vehicle may fail to satisfy evaporation gas regulations under hot weather conditions with a high outdoor temperature, and a fuel smell may occur in the vehicle due to the release of the fuel evaporation gas to the outside. Accordingly, there is a need for a technology capable of alleviating problems due to the generation of the fuel smell. 
     SUMMARY 
     Therefore, the present disclosure has been made keeping in mind the problems encountered in the related art, and an objective of the present disclosure is to provide a fuel evaporation gas treatment system for a vehicle capable of solving problems such as failure to satisfy evaporation gas regulations and generation of a fuel smell due to the inability to purge a fuel evaporation gas when a turbocharger is operated in a vehicle equipped with a turbocharger. 
     The objectives of the present disclosure are not limited to the foregoing, and objectives not mentioned herein will be able to be clearly understood from the following description by those of ordinary skill in the art to which the present disclosure belongs (hereinafter referred to as ‘person of ordinary skill’). 
     In order to accomplish the above objective, an embodiment of the present disclosure provides a fuel evaporation gas treatment system including a sub-purge system configured such that a fuel evaporation gas adsorbed in a canister is recovered into a fuel tank, the sub-purge system including a recovery port formed in the canister, a recovery line connected to the recovery port, an ejector provided to receive fuel delivered by a fuel pump as a driving fluid, to suck a fuel evaporation gas collected in the canister through the recovery line and the recovery port when negative pressure is generated by the driving fluid, and to discharge the fuel evaporation gas to the fuel tank, a driving fluid hose connecting the discharge port of the fuel pump to the driving inlet of the ejector to supply fuel delivered by the fuel pump as a driving fluid to the ejector, and a recovery control valve for opening and closing a fuel passage through which the fuel is supplied to the ejector so that the fuel delivered by the fuel pump is selectively supplied to the ejector. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above and other features of the present disclosure will now be described in detail with reference to certain exemplary embodiments thereof illustrated in the accompanying drawings, which are given hereinbelow by way of illustration only, and thus are not limitative of the present disclosure, and wherein: 
         FIG.  1    schematically shows a conventional fuel system; 
         FIG.  2    shows the configuration of a fuel evaporation gas treatment system according to an embodiment of the present disclosure; 
         FIG.  3    shows a fuel pump module provided with the ejector of the fuel evaporation gas treatment system according to an embodiment of the present disclosure; 
         FIG.  4    is a perspective view showing the canister of the fuel evaporation gas treatment system according to an embodiment of the present disclosure; 
         FIG.  5    is a cross-sectional view showing the configuration of an ejector and a recovery control valve in the fuel evaporation gas treatment system according to an embodiment of the present disclosure; 
         FIG.  6    is a perspective view showing a pump control unit provided with the solenoid of the fuel evaporation gas treatment system according to an embodiment of the present disclosure; 
         FIG.  7    is a perspective view showing the ejector of a sub-purge system in the fuel evaporation gas treatment system according to an embodiment of the present disclosure; 
         FIG.  8    illustrates the state of operation of the recovery control valve in a closed state according to an embodiment of the disclosure; 
         FIG.  9    illustrates the state of operation of the recovery control valve in an open state according to an embodiment of the disclosure; 
         FIG.  10    illustrates a fuel supply state and a purge operation state in the fuel evaporation gas treatment system in which the turbocharger is not operated according to an embodiment of the disclosure; 
         FIG.  11    illustrates a fuel supply state and a purge operation state in the fuel evaporation gas treatment system in which the turbocharger is operated according to an embodiment of the disclosure; 
         FIG.  12    illustrates the state of movement of fuel discharged from a fuel pump in the fuel evaporation gas treatment system in which the turbocharger is not operated according to an embodiment of the disclosure; 
         FIG.  13    illustrates the state of movement of fuel discharged from a fuel pump in the fuel evaporation gas treatment system in which the turbocharger is operated according to an embodiment of the disclosure; and 
         FIG.  14    is a flowchart showing a process for a purge operation of the fuel evaporation gas treatment system according to an embodiment of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     Specific structural or functional descriptions presented in the embodiments of the present disclosure are only illustrated for the purpose of describing the embodiments according to the concept of the present disclosure, and embodiments according to the concept of the present disclosure may be implemented in various forms. In addition, the present disclosure should not be construed as being limited to the embodiments described herein, but should be understood to include all modifications, equivalents, and substitutes included in the spirit and scope of the present disclosure. 
     It will be understood that, although the terms “first,” “second,” etc. may be used herein to describe various elements, these elements are not limited by these terms. These terms are only used to distinguish one element from another element. For instance, a first element discussed below could be termed a second element without departing from the scope of the present disclosure. Similarly, the second element could also be termed the first element. 
     It will be understood that when an element is referred to as being “joined” or “connected” to another element, it can be directly joined or connected to the other element, or intervening elements may be present therebetween. In contrast, it should be understood that when an element is referred to as being “directly connected” or “directly coupled” to another element, there are no intervening elements present. Other expressions that explain the relationships between elements, such as “between,” “directly between,” “adjacent to,” or “directly adjacent to,” should be construed in the same way. 
     Throughout the specification, the same reference numerals will refer to the same or like elements. The terminology used herein is for the purpose of describing the embodiments, and is not intended to limit the present disclosure. As used herein, the singular forms are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprise”, “include”, “have”, etc., when used in this specification specify the presence of stated elements, steps, operations, and/or devices, but do not preclude the presence or addition of one or more other elements, steps, operations, and/or devices. 
     Hereinafter, a detailed description will be given of embodiments of the present disclosure with reference to the appended drawings. 
     The present disclosure is intended to provide a fuel evaporation gas treatment system capable of solving problems such as failure to satisfy evaporation gas regulations and generation of a fuel smell due to the inability to purge a fuel evaporation gas when a turbocharger is operated in a vehicle equipped with a turbocharger. 
     In order to solve the above problems, the fuel evaporation gas treatment system according to the present disclosure includes a sub-purge system configured such that a fuel evaporation gas (including fuel components such as hydrocarbons or the like) may be recovered from the canister to the inside of the fuel tank during operation of the turbocharger, and may be purged. 
       FIG.  2    shows the configuration of a fuel evaporation gas treatment system according to an embodiment of the present disclosure, particularly the configuration of a fuel evaporation gas treatment system including a sub-purge system and the configuration of a fuel system. First, the fuel system for a vehicle includes a fuel tank  1  for storing fuel, a fuel pump module  2  for supplying the fuel stored in the fuel tank  1  to an engine  7 , and a fuel supply line  6  connected to supply fuel from the fuel pump module  2  to the engine  7 . 
     In addition, the fuel system for a vehicle further includes a fuel evaporation gas treatment system for treating and controlling the fuel evaporation gas (HC gas) generated in the fuel tank  1 . The fuel evaporation gas treatment system includes a canister  10  for adsorbing and collecting a fuel evaporation gas generated in the fuel tank  1 , an air filter  13  for removing foreign substances from the air sucked into the canister  10 , a canister close valve  12  for opening and closing a pipe (an ambient atmosphere line)  11  between the canister  10  and the air filter  13 , and a purge control solenoid valve (PCSV)  15  for opening and closing a pipe (a purge line)  14  between the canister  10  and the intake system of the engine  7  or adjusting the extent of opening of the pipe. 
     The canister  10  includes a case filled with an adsorbent material (e.g. activated carbon). The case includes a loading port  10   a  connected to the fuel tank  1  to introduce the fuel evaporation gas from the fuel tank, a purge port  10   b  connected to the engine intake system  4  ( FIG.  1   ) of the engine  7  to supply the fuel evaporation gas to the engine side, and an ambient atmosphere port  10   c  connected to the air filter (canister filter)  13  to suck air from the ambient atmosphere. 
     Moreover, in the present disclosure, the case of the canister  10  is further provided with a recovery port  10   d , and the recovery port  10   d  will be described again when the sub-purge system is described later. 
     The loading port  10   a  of the canister  10  is connected to the fuel tank  1  through a loading line  16 , and the purge port  10   b  of the canister  10  is connected to the intake system of the engine  7  through a purge line  14 . The ambient atmosphere line (vent line)  11 , which is the pipe connected to the air filter  13 , is connected to the ambient atmosphere port  10   c  of the canister  10 . 
     A partition wall (not shown) is provided in the inner space of the case in order to partition a space in which the ambient atmosphere port  10   c  is located from a space in which the purge port  10   b  and the loading port  10   a  are located. The fuel evaporation gas introduced through the loading port  10   a  from the fuel tank  1  sequentially passes through the inner space partitioned by the partition wall. Here, the hydrocarbons, which are fuel components, are adsorbed to the adsorbent material. 
     Also, when the PCSV  15  is opened by the control unit (which may be a pump control unit) while the engine  7  is running and thus the suction pressure, namely the engine negative pressure, acts on the inner space of the canister  10  from the intake system of the engine  7  through the purge port  10   b , air is sucked through the air filter  13  and the ambient atmosphere port  10   c , and the fuel component is desorbed from the adsorbent material of the canister  10  by the sucked air. Moreover, the gas including the fuel component desorbed from the adsorbent material is discharged through the purge port  10   b  and is sucked into the intake system of the engine  7 . 
     In  FIG.  2   , reference numeral ‘ 3 ’ denotes a filler neck assembly for injecting fuel into the fuel tank  1 . In  FIG.  2   , reference numeral ‘ 5 ’ denotes a valve installed in the fuel tank  1  to which the loading line  16  is connected, which may be a typical roll-over valve. 
     Meanwhile, the fuel evaporation gas treatment system according to an embodiment of the present disclosure further includes a sub-purge system capable of recovering the collected fuel evaporation gas from the canister into the fuel tank and purging the fuel evaporation gas under predetermined driving conditions for a vehicle (e.g. conditions for operation of a turbocharger). 
     The fuel evaporation gas treatment system including the sub-purge system may be applied to a vehicle equipped with a turbocharger. Furthermore, the fuel evaporation gas treatment system including the sub-purge system is capable of solving problems such as failure to satisfy evaporation gas regulations and generation of a fuel smell, which conventionally occur due to impossibility of purging when the turbocharger is operated, as described below. 
     In an embodiment of the present disclosure, the sub-purge system includes a recovery port  10   d  provided at one side of the case of the canister  10 , an ejector  140  connected to the recovery port  10   d  through a recovery line  17  and configured such that the fuel delivered by the fuel pump  120  is received as a driving fluid and the fuel evaporation gas collected in the canister  10  is sucked through the recovery line  17  and is then discharged into the fuel tank during operation thereof, and a recovery control valve  150  configured such that the fuel, serving as a driving fluid, delivered by the fuel pump  120  is selectively supplied or not supplied to the ejector  140 . 
       FIG.  3    is a perspective view showing a fuel pump module provided with the ejector of the fuel evaporation gas treatment system according to an embodiment of the present disclosure, and  FIG.  4    is a perspective view showing the canister of the fuel evaporation gas treatment system according to an embodiment of the present disclosure. 
     With reference to  FIG.  3   , the fuel pump module  2  includes a fuel pump  120  for sucking and delivering fuel charged in the fuel tank  1  ( FIG.  2   ) while the impeller mounted on the motor shaft rotates during operation of the pump motor. The fuel pump  120  may be fixedly joined to the inside of a reservoir cup  130 . Also, the reservoir cup  130  is connected to a fuel pump plate  110  at the upper side via a support bar  131 . 
     The fuel pump plate  110  is mounted over the opening in the fuel tank  1  to seal the inside of the fuel tank, and serves to support and fix the fuel pump  120  and the reservoir cup  130  inserted into the fuel tank through the support bar  131  in the state of being fixedly mounted over the opening in the fuel tank  1 . 
     Also, in the fuel pump module  2 , a fuel hose  122  is connected to the discharge port of the fuel pump  120 , and the fuel hose  122  is connected to the inner surface (the lower surface) of the fuel pump plate  110  inside the fuel tank  1 . Here, a through-hole is formed in the fuel pump plate  110 , and the fuel hose  122  is connected to communicate with a fuel supply port  111  ( FIG.  6   ) formed in the outer surface (the upper surface) of the fuel pump plate  110  via the through-hole. 
     Also, a fuel supply line  6  ( FIG.  2   ) is connected to the fuel supply port  111 , and the fuel supply line  6  is connected to the engine  7  ( FIG.  2   ). Accordingly, when the fuel pump  120  is operated, the fuel sucked into the reservoir cup  130  by the fuel pump  120  is discharged through the discharge port of the fuel pump  120  and is then pumped into the engine  7  along the pathway of the fuel hose  122 , the fuel supply port  111 , and the fuel supply line  6 . 
     Also, one end of a driving fluid hose  125  is connected to the discharge port of the fuel pump  120 , and one end of the driving fluid hose  125  is connected to the discharge port of the fuel pump  120  via a 3-way connector  121 . Here, both the fuel hose  122  and the driving fluid hose  125  may be connected to the discharge port of the fuel pump  120  via the 3-way connector  121 . Specifically, the inlet of the 3-way connector  121  is connected to the discharge port of the fuel pump  120 , the fuel hose  122  is connected to one of two outlets of the 3-way connector  121 , and the driving fluid hose  125  is connected to the remaining outlet of the 3-way connector  121 . Alternatively, the driving fluid hose  125  may be a hose that branches from the fuel hose  122 . 
     The remaining end of the driving fluid hose  125  is connected to the driving inlet  143  ( FIG.  5   ) of the ejector  140 . Accordingly, when the fuel pump  120  is operated, some of the fuel discharged through the discharge port of the fuel pump  120  may be supplied as a driving fluid to the driving inlet  143  of the ejector  140  through the driving fluid hose  125 . 
       FIG.  5    is a cross-sectional view showing the configuration of the ejector  140  and the recovery control valve  150  installed in the fuel pump module  2  in the fuel evaporation gas treatment system according to an embodiment of the present disclosure. In order to show the inner configuration of the recovery control valve  150 , the housing  141  of the ejector  140  in which the recovery control valve is installed and the housing  161  of the pump control unit  160  are shown in cross section. 
       FIG.  6    is a perspective view showing the fuel pump plate  110  provided with the solenoid  151  of the recovery control valve  150  of the fuel evaporation gas treatment system according to an embodiment of the present disclosure. In  FIG.  6   , a cover  163  ( FIG.  5   ) installed on the upper surface of the housing body to seal the inner space of the housing body  162  in the housing  161  of the pump control unit  160  is not shown. As shown in the drawing, the pump control unit  160  is integrally installed to the fuel pump plate  110  of the fuel pump module  2 . 
     With reference to  FIGS.  2  and  6   , the fuel supply port  111  and the suction port  112  are integrally formed on the outer surface (the upper surface) of the fuel pump plate  110 . The fuel supply line  6  for supplying fuel to the engine  7  is connected to the fuel supply port  111 , and the recovery line  17  for sucking the fuel evaporation gas collected in the canister  10  and recovering the same to the fuel tank  1  is connected to the suction port  112 . 
     In the present disclosure, the ejector  140  generates negative pressure using the fuel delivered by the fuel pump  120  as a driving fluid, and the negative pressure thus generated is used as a power source for purging the fuel evaporation gas in the canister  10 . The ejector  140  is installed inside the fuel tank  1 , and may be fixedly installed to the fuel pump module  2  even inside the fuel tank  1 . Also, the ejector  140  is provided to eject and discharge the fuel used as the driving fluid and the fuel evaporation gas purged from the canister  10  into the fuel tank  1  through a nozzle  145 . 
       FIG.  7    is a perspective view showing the ejector of the sub-purge system in the fuel evaporation gas treatment system according to an embodiment of the present disclosure. Here, the ejector  140  may include a housing  141  having an inner passage  142  ( FIG.  5   ), a driving inlet  143  formed in the housing  141  and connected with the driving fluid hose  125  ( FIG.  5   ) to supply fuel delivered through the driving fluid hose  125  from the fuel pump  120  as a driving fluid, a suction inlet  144  formed in the housing  141  and into which the fuel evaporation gas (HC gas) desorbed from the adsorbent material of the canister  10  as a suction fluid is sucked, and a nozzle  145  which is formed in the housing  141  and discharges a mixture of the fuel that is supplied through the driving inlet  143  and is then passed through the inner passage  142  of the housing  141  and the fuel evaporation gas sucked into the inner passage  142  of the housing  141  through the suction inlet  144 . 
     In the ejector  140 , when the fuel discharged from the fuel pump  120  is supplied to the inner passage  142  of the ejector  140  through the driving fluid hose  125 , the supplied fuel passes through the inner passage  142  of the ejector  140  at a high speed. Also, negative pressure is generated in the inner passage  142  of the ejector  140  while the fuel passes through the inner passage  142  of the ejector  140  at a high speed. 
     Ultimately, the negative pressure generated in the inner passage  142  of the ejector  140  enables the fuel evaporation gas collected in the canister  10  to be sucked into the inner passage  142  of the ejector  140  through the recovery port  10   d , the recovery line  17 , the suction port  112 , the suction hose  123 , the check valve  124 , and the suction inlet  144  of the ejector  140 . The fuel evaporation gas thus sucked passes through the inner passage  142  of the ejector  140  together with the fuel supplied as a driving fluid to the ejector  140 , and is then discharged into the fuel tank  1  through the nozzle  145 . 
     The suction inlet  144  of the ejector  140  is connected to the suction port  112  provided in the fuel pump plate  110  through the suction hose  123 . Also, the recovery line  17  ( FIG.  2   ) is connected to the suction port  112  of the fuel pump plate  110 , and the recovery line  17  is connected to the recovery port  10   d  of the canister  10 , as described above. 
     The nozzle  145  corresponds to an outlet through which the fuel as the driving fluid and the fuel evaporation gas as the suction fluid are discharged in a mixed state from the housing  141 , and is provided to eject the fuel and the fuel evaporation gas into the fuel tank  1 . 
     The suction port  112  is installed on the outer surface (the upper surface) of the fuel pump plate  110 , and the inner passage  142  of the suction port  112  communicates with a through-hole that perforates the fuel pump plate  110 . Here, a check valve  124  is installed to the through-hole in the inner surface (the lower surface) of the fuel pump plate  110  to communicate with the suction port, and the suction hose  123  may be connected to the check valve  124 . 
     The check valve  124  is installed to the suction hose  123  to prevent the fuel supplied into the ejector  140  by the fuel pump  120  from flowing toward the canister  10  through the suction hose  123  and to enable only the fuel evaporation gas in the canister  10  to be sucked into the inner passage  142  of the ejector  140  by the negative pressure inside the ejector  140 . 
     In an embodiment of the present disclosure, the recovery control valve  150  may be an electromagnetic valve whose opening/closing operation is controlled in response to a control signal of the pump control unit  160 . Also, the recovery control valve  150  is a valve configured such that the driving fluid, that is, the fuel delivered along the driving fluid hose  125  by the fuel pump  120 , is selectively supplied or not supplied to the inner passage  142  of the ejector  140 . The recovery control valve  150  may be a solenoid valve configured to open or close the inlet  143  and the inner passage of the ejector  140  using a valve body  154  integrally installed to a plunger  152  by moving the plunger  152  back and forth through control of current supply to the solenoid  151  or interruption of the current supply. 
     Here, the fuel passage may be the inner passage  142  provided in the housing  141  of the ejector  140 . More specifically, the fuel passage may be the inner passage  142  that connects the suction inlet  144  and the nozzle  145  inside the housing  141  of the ejector  140 . As such, the lower end of the plunger  152  and the valve body  154  installed at the lower end of the plunger  152  are joined to thereby be inserted into the housing  141  of the ejector  140 . 
     In an embodiment of the present disclosure, a connection passage portion  146  may be formed to extend long in a predetermined direction, for example upwards, on the housing  141  of the ejector  140 , and the valve body  154  is located in the connection passage portion  146  to be able to slide along the inner surface thereof in the state in which the plunger  152  is inserted therein. Also, the connection passage portion  146  of the ejector  140  is joined to a guide passage portion  165 , formed to extend long downwards from the inner surface (the lower surface) of the fuel pump plate  110 . 
     Also, both the connection passage portion  146  and the guide passage portion  165  may be provided in a pipe form, and may be joined to each other such that the inner passages of the two passage portions  146 ,  165  are interconnected. Here, the guide passage portion  165  is joined to pass through the fuel pump plate  110  and the bottom of the housing  161  of the pump control unit  160 . The upper end of the guide passage portion  165  may be joined to the pump control unit  160 , and the guide passage portion  165  may be formed to extend long upwards from the bottom of the housing, even inside the housing  161  of the pump control unit  160 . 
     The pump control unit  160  receives a flow rate signal representing a fuel flow rate required for the engine from an engine control unit (not shown), and controls the driving speed (rpm) of the fuel pump  120  in response to the received flow rate signal. In this process, the pump control unit  160  drives the pump motor of the fuel pump  120  and outputs a PWM (pulse width modulation) signal for controlling the rotation speed thereof. 
     In an embodiment of the present disclosure, the housing  161  of the pump control unit  160  may be provided in a plate-integrated structure that is integrally fixed to the outer surface (the upper surface) of the fuel pump plate  110  via the guide passage portion  165 . Here, as described above, the guide passage portion  165  is formed to extend long upwards from the bottom of the housing  161 , even inside the housing  161  through the bottom of the housing  161  of the pump control unit  160 . 
     Also, the inner space of the housing  161  of the pump control unit  160  is provided with a printed circuit board (PCB)  164  and a solenoid (coil)  151  of the solenoid valve, which is the recovery control valve  150 . Also, a cover  163  constituting the housing  161  of the pump control unit  160  is installed on the upper surface of the housing body  162 , and a guide pin  156  may be fixed to be disposed vertically downwards from the inner surface of the cover  163 . 
     Also, the plunger  152  is slidably joined to the outer periphery of the guide pin  156  in the axial direction (the up and down direction in the drawing), and the plunger  152  is assembled to be disposed along the inner passages of the connection passage portion  146  and the guide passage portion  165 . Here, the upper portion of the plunger  152  may be disposed in the vicinity of the solenoid  151 , and specifically, may be disposed below the solenoid  151 , or may be disposed to pass through the solenoid  151 . 
     Also, a return spring  155  for elastically supporting the plunger  152  is installed inside the guide passage portion  165 , and the return spring  155  provides elastic restoring force for returning the plunger  152  downwards. Accordingly, the recovery control valve  150  becomes a normal close valve that maintains a closed state when power is turned off. 
     The solenoid  151  of the recovery control valve  150  is connected to the vehicle battery through a driving circuit unit (not shown), and the driving circuit unit is provided to selectively apply or not apply the current of the battery to the solenoid  151  in response to the control signal output by the pump control unit  160 . 
       FIGS.  8  and  9    show the state of operation of the recovery control valve  150 .  FIG.  8    shows the recovery control valve  150  in a closed state, and  FIG.  9    shows the recovery control valve  150  in an open state. When the recovery control valve  150  is closed, the ejector  140  enters an off state and does not operate, and negative pressure, which is a purge power source, is not generated inside the ejector  140 , so the fuel evaporation gas in the canister is not sucked into the ejector  140 . 
     On the other hand, when the recovery control valve  150  is opened, the ejector  140  enters an on state and operates, and negative pressure, which is a purge power source, is generated inside the ejector  140 , so the fuel evaporation gas in the canister may be sucked into the ejector  140 . 
     More specifically, when the pump control unit  160  outputs a control signal for maintaining the recovery control valve  150  in an open state to supply the fuel, which is the driving fluid, to the ejector  140 , the driving circuit unit performs control so that the current of the battery is applied to the solenoid  151  in response to this control signal. 
     Accordingly, the solenoid  151  is electrically charged, and electromagnetic force is generated in the solenoid thereby pulling the plunger  152  upwards in the drawing. Ultimately, the plunger  152  is pulled upwards by the electromagnetic force and ascends while exceeding the force of the return spring  155 . Accordingly, the inner passage of the inlet  143  and the inner passage (fuel passage)  142  of the ejector  140  are opened by the valve body  154 . 
     Here, the ejector  140  operates while the fuel delivered by the fuel pump  120  is supplied to the inner passage  142  of the ejector  140 . Negative pressure is generated in the inner passage of the ejector  140  while the fuel passes at a high speed. Ultimately, the fuel evaporation gas adsorbed in the canister  10  is sucked into the inner passage  142  of the ejector  140  through the recovery port  10   d , the recovery line  17 , the suction port  112 , the suction hose  123 , the check valve  124 , and the suction inlet  144 . 
     Also, the fuel evaporation gas sucked into the ejector  140  passes through the inner passage  142  of the ejector  140  together with the fuel as the driving fluid, and is discharged and recovered into the fuel tank  1  via the nozzle  145  of the ejector  140 . In this way, the ejector  140  acts as a kind of jet pump in a manner in which the fuel evaporation gas is sucked from the outside and is then transferred to the inside of the fuel tank  1 , in addition to generation of negative pressure therein using the fuel delivered by the fuel pump  120  as the driving fluid. 
     On the other hand, when the pump control unit  160  outputs a control signal for closing the recovery control valve  150  so that the fuel, which is the driving fluid, is not supplied to the ejector  140 , the driving circuit unit performs control so that the current of the battery is not applied to the solenoid  151  in response to this control signal. Accordingly, the solenoid  151  is not electrically charged, and thus the plunger  152  descends downwards due to the elastic restoring force of the return spring  155 . 
     When the plunger  152  descends in this way, the valve body  154  closes the fuel passage of the ejector  140 . Even when the fuel pump  120  is operated, the fuel delivered by the fuel pump  120  is not supplied to the inner passage  142  of the ejector  140 , so the ejector  140  does not operate, and the fuel evaporation gas adsorbed in the canister  10  is not sucked into the ejector  140 . 
     The configuration of the sub-purge system newly added in the fuel evaporation gas treatment system according to the embodiment of the present disclosure is specified above. Hereinafter, the control and operation of the sub-purge system are described in more detail. 
       FIGS.  10  and  11    show a fuel supply state and a purge operation state depending on whether or not a turbocharger is operated in the fuel evaporation gas treatment system according to an embodiment of the present disclosure.  FIG.  10    shows the turbocharger which is not operated and  FIG.  11    shows the turbocharger which is operated. 
     Also,  FIGS.  12  and  13    show the state of movement of the fuel discharged from the fuel pump  120  through the 3-way connector  121  in the fuel evaporation gas treatment system according to an embodiment of the present disclosure,  FIG.  12    showing the turbocharger which is not operated and  FIG.  13    showing the turbocharger which is operated. 
     Also,  FIG.  14    is a flowchart showing a purge operation process in the fuel evaporation gas treatment system according to an embodiment of the present disclosure. With reference to  FIGS.  2  and  10  to  14   , the fuel supply state, the purge operation state, and the purge operation process depending on whether or not the turbocharger is operated are described below. 
     First, when predetermined conditions for operation of the turbocharger are satisfied, the engine control unit initiates control for operation of the turbocharger, and simultaneously transmits a turbocharger operation signal to the pump control unit  160 . Also, a flow rate signal representing a fuel flow rate required for the engine while the engine is running is generated and output from the engine control unit. Accordingly, the pump control unit  160  receives the turbocharger operation signal and the flow rate signal. 
     Then, the pump control unit  160  increases the duty value of the PWM signal for driving the pump motor by a predetermined amount in consideration of the rate at which fuel is to be supplied to the ejector  140 , in addition to the fuel flow rate required for the engine  7  during operation of the turbocharger. In the state of running of the engine in which the turbocharger is operated, fuel must be supplied both to the engine  7  and to the ejector  140 , so the duty value of the PWM signal for driving the pump motor is increased. Accordingly, the driving speed (rpm) of the fuel pump  120  increases compared to when the turbocharger is not operated, and ultimately, the fuel may be supplied at a flow rate obtained by combining the fuel flow rate required for the engine  7  and the predetermined rate at which fuel is to be supplied to the ejector  140 , by the fuel pump  120  (S 11 , S 12 ). 
     Also, in the state of operation of the turbocharger, the pump control unit  160  performs control so that the recovery control valve  150  is opened (S 13 ). Specifically, the solenoid valve, which is the recovery control valve  150 , is turned on, and the pump control unit  160  generates and outputs a control signal for applying current to the solenoid  151 . When the current is applied to the solenoid  151  in this way, the plunger  152  of the solenoid valve is pulled upwards by the electromagnetic force of the solenoid  151  and ascends. As such, the inner passage of the inlet  143  and the inner passage (fuel passage) of the ejector  140  are opened while the valve body  154  ascends. 
     When the solenoid valve, which is the recovery control valve  150 , is opened in this way, some of the fuel delivered by the fuel pump  120  is supplied as a driving fluid to the ejector  140 , so the ejector  140  is operated. As such, the remaining fuel except for some fuel supplied to the ejector  140 , among the fuel delivered by the fuel pump  120 , is supplied to the engine  7 , and the fuel is simultaneously supplied to the engine  7  and the ejector  140  by the fuel pump  120  (S 14 ). 
     When the ejector  140  is operated in this way, the sub-purge system is operated. Specifically, while the fuel supplied as a driving fluid by the fuel pump  120  passes through the inner passage  142  of the ejector  140  at a high speed, the negative pressure serving as the purge power source is generated in the inner passage  142  of the ejector  140  (S 15 ), and the fuel evaporation gas collected in the canister  10  may be sucked into the inner passage  142  of the ejector  140  by this negative pressure. The fuel evaporation gas thus sucked moves toward the nozzle  145  together with the fuel in the inner passage  142  of the ejector  140 , and is then discharged into the fuel tank  1  through the nozzle (S 16 ). 
     In the state in which the turbocharger is operated, the fuel evaporation gas in the canister  10  is sucked by the negative pressure of the ejector  140  and is then purged to the inside of the fuel tank  1 , so conventional problems in which the fuel evaporation gas exceeding the collection capacity of the canister is released outside the vehicle may be solved. Moreover, problems such as failure to satisfy vehicle evaporation gas regulations and generation of a fuel smell may be solved. 
     Meanwhile, in the state of running of the engine in which the turbocharger is not operated, the driving speed (rpm) of the fuel pump  120  is controlled by the pump control unit  160  to supply only the fuel flow rate required for the engine based on the flow rate signal received from the engine control unit. 
     Also, in the state in which the turbocharger is not operated, the pump control unit  160  performs control so that the recovery control valve  150  is closed. Specifically, the solenoid valve, which is the recovery control valve  150 , is controlled in an off state (S 17 ). When the solenoid valve is controlled in the off state in this way, the fuel serving as the driving fluid is not supplied to the ejector  140 , and negative pressure is not generated inside the ejector  140  (S 18 ). Moreover, because the ejector  140  is not operating, the purge power source at this time is the engine negative pressure, and the fuel evaporation gas collected in the canister  10  is sucked into the engine  7  by the engine negative pressure and is then burned (S 19 ). 
     As described above, according to the fuel system of the present disclosure, even when the turbocharger is operated, the fuel evaporation gas collected in the canister may be sucked by the negative pressure generated in the ejector and purged into the fuel tank, ultimately satisfying vehicle evaporation gas regulations as well as solving problems related to the generation of a fuel smell. 
     Moreover, since the fuel is ejected at a high pressure into the fuel tank using the ejector, vaporization of the fuel may be induced in the fuel tank. Specifically, the fuel ejected into the fuel tank may be vaporized, whereby, when the temperature and pressure in the fuel tank are high, an effect of decreasing the temperature and pressure due to latent heat of evaporation may be expected. 
     As is apparent from the above description, in the fuel evaporation gas treatment system according to the present disclosure, the fuel evaporation gas collected in the canister is sucked by the ejector during operation of the turbocharger and is recovered into the fuel tank, thereby solving conventional problems such as failure to satisfy evaporation gas regulations and generation of a fuel smell due to the inability to purge a fuel evaporation gas. 
     The present disclosure has been described in detail with reference to preferred embodiments thereof. However, it will be appreciated by those skilled in the art that changes may be made in these embodiments without departing from the principles or spirit of the present disclosure, the scope of which is defined in the appended claims and their equivalents.