Patent Publication Number: US-9421983-B2

Title: Active pressurization system making use of platform track area upper slab of underground train station

Description:
This application claims the priority of Korean Patent Application No. 10-2011-0138704, filed on Dec. 20, 2011 in the KIPO (Korean Intellectual Property Office), the disclosure of which is incorporated herein entirely by reference. Further, this application is the National Stage application of International Application No. PCT/KR2012/004333, filed Jun. 1, 2012, which designates the United States and was published in Korean. Each of these applications is hereby incorporated by reference in their entirety into the present application. 
     TECHNICAL FIELD 
     The present invention relate to an active pressurization system utilizing an upper slab of a platform track in an underground train station, and more particularly to an active pressurization system utilizing an upper slab of a platform track area in an underground train station, which can reduce an air pressure generated by a fast train passing through the underground train station when a slow train waits while the fast train passes through the train station, to solve a problem of ear-discomfort of a waiting passenger, and can allow passengers to be safely evacuated by facilitating ventilation of smoke generated in the train station in an event of a train fire. 
     BACKGROUND ART 
     Among underground train stations having recently been constructed or opened for traffic in Korea, fast trains going direct to only primary transfer stations (e.g., Seoul Metro Line 9 or Incheon International Airport Train of Korea) are under operation, and for traffic operation of fast trains, a construction of 4-line-2-platforms type underground train stations has been planned. 
     However, even if the passing speed of the fast train currently in operation in underground train station is lower than or equal to 100 km/h, air pressure problems occurring in the platform are being reported. In future, an air pressure problem of a passenger waiting space may be raised in the underground train station where high-speed trains are running. 
     Meanwhile, in Hong Kong, ΔP of 700 Pa has been stipulated as the standard for ear-discomfort of a waiting passenger. In the underground train station where fast trains pass through, the problem of ear-discomfort of a waiting passenger may be solved by means of the structural methods such as increase of the number of vertical pits and ventilation pits or an adjustment of a tunnel pit mouth, which may, however, considerably increase the construction cost of underground train station. 
     DISCLOSURE OF THE INVENTION 
     Technical Problem 
     Aspects of the present invention provide an active pressurization system utilizing an upper slab of a platform track area of an underground train station, which can solve a problem of ear-discomfort of a waiting passenger by reducing an air pressure generated when a fast train passes through the underground train station, where a slow train can wait while the fast train passes through the train station, and can improve the safety of evacuated passengers by facilitating ventilation of smoke generated in the train station in an event of a train fire in the underground train station. 
     Technical Solution 
     To solve the above noted problems, the present invention is provided as follows. 
     In accordance with one aspect of the present invention, there is provided an active pressurization system utilizing an upper slab of a platform track area of an underground train station, wherein a track area, where a fast train and a slow train pass through in the station of an underground train station, is divided into a fast-train running space and a slow-train running space by means of a partition wall, a first and a second air-stream out- and in-flow space respectively linking through to the fast-train running space and the slow-train running space are formed in an upper slab of the train station. 
     Here, the front end of the second air-stream out- and in-flow space may be provided with a first port and a first damper, while the rear end is provided with a second port and a second damper, the second air-stream out- and in-flow space may be provided with a third port for venting of the slow-train running space, and the first air-stream out- and in-flow space may be provided with a fourth port for venting of the fast-train running space. 
     In addition, when a fast train is running, a control panel that receives sensing signals input from pressure sensors for sensing pressure ensures that, on the slow-train running space where there is no slow train waiting, the first and second ports are closed and the first and second dampers are open and the third port is open and on the fast-train running space the fourth port is open, while on the slow-train running space where there is a slow train waiting, the first and second ports are open and the first and second dampers are closed and an air supplying and venting fan is driven in such a way as to supply air to the slow-train running space where there is a slow train waiting. 
     Here, the first and second air-stream out- and in-flow spaces may be provided only on the underground train station where fast train and slow train run. 
     In addition, the air supplying and venting fan may be a ventilating fan installed in an adjacent ventilating plant of the underground train station. 
     The pressure sensors may be equidistantly installed from a location more than 3 km apart from the main-line section connected to the underground train station. 
     Here, if there is an adjacent underground train station, a pressure sensor may be installed in the main line section which enters or exits from the underground train station. 
     A fire detecting device for sensing a fire may be provided in the underground train station, and if a sensing signal is input from the fire detecting device, the control panel may control the third or fourth port to be opened to vent smoke in the fast-train running space and the slow-train running space. 
     In particular, the fire detecting device may be one of a heat sensor, a gas sensor and a thermal image camera. 
     Advantageous Effects 
     As described above, according to the present invention, the problem of ear-discomfort of waiting passengers by providing the fast-train running space where fast trains pass through and the slow-train running space where slow trains either stop or pass through, and by actively adjusting the supply and venting of air. In addition, the safety of evacuated passengers can be improved by facilitating ventilation of smoke generated in the station in an event of a train fire in the underground train station. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a cross-sectional view of a platform of an underground train station for an active pressurization system utilizing an upper slab of a platform track area of the underground train station according to the present invention; 
         FIG. 2  is a plan view illustrating an upper portion of the platform of an underground train station for illustrating the active pressurization system active pressurization system utilizing an upper slab of a platform track area of the underground train station according to the present invention; 
         FIG. 3  is a view illustrating an installation position of a pressure sensor for the active pressurization system utilizing an upper slab of a platform track area of an underground train station according to the present invention; 
         FIG. 4  is a schematic diagram illustrating a control operation of the active pressurization system utilizing an upper slab of a platform track area of an underground train station according to the present invention; 
         FIG. 5  is a schematic diagram for explaining behavior characteristics of compression waves and expansion waves generated when a train enters and passes through a station at a high speed; 
         FIG. 6  is a diagram illustrating computational fluid dynamics (CFD) analysis result for ear-discomfort depending on presence or absence of the active pressurization system (APS) utilizing an upper slab of a platform track area of an underground train station according to the present invention; and 
         FIG. 7  is a diagram illustrating CFD analysis result for smoke-ventilating performance in an event of a fire depending on presence or absence of the active pressurization system (APS) utilizing an upper slab of a platform track area of an underground train station according to the present invention. 
     
    
    
     MODE FOR CARRYING OUT THE INVENTION 
     Hereinafter, advantages and features of the active pressurization system utilizing an upper slab of a platform track area of an underground train station according to the present invention will be understood through specific embodiments of the present disclosure described in detail with reference to the accompanying drawings. 
     Referring to  FIGS. 1 to 4 , the active pressurization system (APS) utilizing an upper slab of a platform track area of an underground train station  1  according to the present invention may form a space (pressurization zone) capable of supplying or venting air to actively process the pressure for each track using the upper slab of the platform track area, and may actively control the pressure through the supplying or venting of the air. 
     Here, the pressure waves generated in the train station can be reduced or blocked by supplying or venting the air through ports installed on the upper slab of the train station using a venting fan installed in an adjacent ventilating plant  2  or by installing a fan for active pressurization. 
     In particular, if a propagation of the pressure wave is sensed by a pressure sensor  100  installed in a neighboring main-line section  3 , it is possible to reduce the magnitude of the pressure wave propagated from the main-line section  3  by venting the air through the port provided at an upper portion of a fast-train running space  110  of the underground train station  1 , through which a fast train  10  passes, and the propagated pressure wave is reduced or blocked by supplying the air to a slow-train running space  120  through which a slow train  20  passes, thereby preventing a problem of ear-discomfort from being caused to a passenger waiting in the underground train station  1 . 
     In addition, a fire-detecting device  102  is installed at an upper portion of the underground train station  1  and a location where a fire has broken out is sensed by the fire-detecting device to then open an upper port corresponding to the sensed fire location for evacuating smoke, thereby preventing the smoke from being propagated. 
     To this end, in the present invention, in a 4-line-2-platform type underground train station where fast trains and slow trains separately run, a space-dividing partition wall  119  can be installed in the track area to divide the fast-train running space  110  through which the fast train  10  passes and a slow-train running space  120  through which the slow train  20  passes, each of which acting as the pressurization zone. The fast train is an express train running with high speed and does not stop at every station for speedy operation. The slow train is an accommodation train running with low speed compared to the speed of the express train and stops at every station. 
     The space in the train station is divided into the fast-train running space  110  and the slow-train running space  120  by the space-dividing partition wall  119  to form the pressurization zones of the track area based on the upper active pressurization system (APS). 
     For the pressurization, a first and second air-stream out- and in-flow spaces  112  and  122 , which are connected to the fast-train running space  110  and the slow-train running space  120 , respectively, are formed at an upper slab of the train station on the track area to supply or vent the air to/from the fast-train running space  110  and the slow-train running space  120 . 
     The first and second air-stream out- and in-flow spaces  112  and  122  for supplying or venting the air to/from the fast-train running space  110  and the slow-train running space  120  are defined at only an upper portion of the train station in which the fast train  10  and the slow train  20  run, and spatial dimensions of the flow spaces may be determined according to the characteristics of the train station. Preferably, the first and second air-stream out- and in-flow spaces are preferably have the heights of 1 m or greater. 
     Meanwhile, an air supplying and venting fan  104  is provided to supply or vent the air to/from the first and second air-stream out- and in-flow spaces  112  and  122 . A ventilating fan installed in a ventilating plant  2  adjacent to the underground train station  1  may be used as the air supplying and venting fan  104  or separate fans may be installed to reduce a pressure applied to the train station. The number of fans is preferably determined according to the characteristics of tracks in the train station (for example, the numbers and arrangements of fast trains and slow trains). 
     At this time, the first and second air-stream out- and in-flow spaces  112  and  122  provided on the upper slab of the underground train station  1  are connected to the adjacent ventilating plant  2 , and the connection method thereof may be varied according to the planning characteristics of the pressurization zones in the underground train station  1 . 
     Meanwhile, the pressure sensor  100  capable of sensing the pressure waves generated when a train passes through a tunnel is installed for the active pressurization system (APS). Here, the location to which the pressure sensor  100  is installed may be selected according to the train running speed and the presence or absence of an adjacent underground train station and may be equidistantly installed from a location more than 3 km apart from the main-line section. In addition, when there is an adjacent underground train station  1 ′, the sensor may also be installed in the underground train station  1 ′. The pressure sensor is installed in the main-line section which enters or exits from the underground train station  1 ′. 
     Meanwhile, the fire-detecting device  102  is installed in the underground train station  1  to sense occurrence of a fire. Here, even though a thermal sensor or a gas sensor may be utilized as the fire-detecting device  102 , a thermal image camera is preferably employed as the fire detecting device to grasp a location in which a fire is occurred. 
     In addition, the front end of the second air-stream out- and in-flow space  122  is provided with a first port  130  and a first damper  132  for the pressurization in the train station, and the rear end is provided with a second port  131  and a second damper  133 , the second air-stream out- and in-flow space  122  is provided with a third port  135  for venting of the slow-train running space  120 , and the first air-stream out- and in-flow space  112  is provided with a fourth port  136  for venting of the fast-train running space  110 . 
     At this time, opening/closing of the first to fourth ports  130 ,  131 ,  135  and  136  and the first and second dampers  132  and  133  may be controlled by a control panel  106 . Of course, when a sensing signal is input through the pressure sensor  100  and the fire-detecting device  102 , the control panel  106  selectively controls the first to fourth ports  130 ,  131 ,  135  and  136  and the first and second dampers  132  and  133  to be opened or closed and controls the air supplying and venting fan  104 . 
     In this case, in the slow-train running space  120 , an aperture ratio of the first port  130  for blocking the pressure wave is preferably adjusted to generate a pressure in proportion with the magnitude of the pressure wave sensed by the pressure sensor  100  in the main-line section. 
     With this configuration, the APS operates differently at normal times and in an event of a fire and is differently controlled according to the operating condition. 
     That is to say, when the fast train  10  enters a tunnel in a high speed at normal times, as shown in  FIG. 5 , compression waves are generated due to a piston phenomenon caused by the front end of the fast train  10 . The, gas-phase compression waves adiabatically change. 
     In addition, magnitudes of the compression waves generated when the train enters the tunnel are determined according to geometric structures of the tunnel and the train and the running speed of the train, and the compression waves generated when the train enters in the tunnel are propagated along the tunnel due to sonic characteristics. The compression waves are changed into expansion waves by the exit of the tunnel, a change in the geometric structure and the ventilating plant  2  in the tunnel. The compression waves and the expansion waves are repeatedly moved within the tunnel, causing an ear-discomfort to the waiting passenger. 
     Therefore, in order to solve the problem of ear-discomfort at normal times, first, when a propagation of the pressure wave is sensed by the pressure sensor  100 , the control panel  106  controls the first and second ports  130  and  131  positioned on both ends of the second air-stream out- and in-flow space  122  arranged on the track area of the slow-train running space  120 , where the slow train  20  is not waiting, to be closed, the first and second dampers  132  and  133  to be opened and the third port  135  to be opened, thereby relieving the pressure wave by venting air from the slow-train running space  120  in which the slow train  20  is not waited. 
     In this case, the control panel  106  controls the fourth port  136  provided on an upper portion of the fast-train running space  110 , where the fast train  10  runs, to be opened, thereby relieving the pressure wave by venting the air from the fast-train running space  110 . 
     At this time, the fourth port  136  is a pressure wave reducing port, and the pressure in the fast-train running space  110  is relieved by opening the fourth port  136 . 
     In addition, the control panel  106  drives the air supplying and venting fan  104 , opens the first and second ports  130  and  131  positioned on an upper portion of the track area of the slow-train running space  120  and closes the first and second dampers  132  and  133  to supply the air to the slow-train running space  120  in which the slow train  20  is waiting, thereby preventing the pressure wave generated when the fast train  10  runs from being propagated to the slow-train running space  120  in which the slow train  20  is waiting. 
     Meanwhile, in an event of a fire, a sensing signal transmitted from the fire-detecting device  102  installed in the train station is input to the control panel  106 . Although the fire is spread, the origin of fire can be discriminated by a plurality of fire-detecting devices  102  installed in the train station, thereby venting smoke by opening the third or fourth port  135 ,  136  provided above the origin of fire. 
     In a case where a fire breaks out in the fast-train running space  110 , the air is supplied to the slow-train running space  120  by opening the first or second port  130  or  131  positioned on an upper portion of the slow-train running space  120  and controlling driving of the air supplying and venting fan  104 , thereby forming a pressurized zone and allowing passengers staying in the slow-train running space  120  to be safely evacuated. 
     The aforementioned active pressurization system (APS) is installed in the underground train station and is subjected to computational fluid dynamics (CFD) analysis to analyze ear-discomfort. The CFD analysis result is shown in  FIG. 6 . The CFD analysis is conducted under the following assumptions: The running speed of the fast train  10  is 250 km/h to produce a pressure wave of 1500 Pa in the main-line section. The pressure of the first and second ports  130  and  131  for supplying the air to the slow-train running space  120  is maintained at 470 Pa. The ventilating plant  2  connected to the main-line section is not employed to prevent the behavior of the pressure wave from being affected by the ventilating plant. Waiting conditions of the slow train  20  are employed. The pressure wave produced in the slow-train running space  120  is propagated to the platform due to an opened platform screen door (PSD)  108  when the slow train  20  is waiting. The APS according to the present invention can obtain satisfactory CFD analysis by employing 700 Pa as the standard for ear-discomfort of a waiting passenger, like in Hong Kong. 
     In an event of a fire, the smoke venting performance evaluated by CFD analysis is shown in  FIG. 7 . That is to say, assuming that a fire broke out in the fast train  10 , the fast train stops in the underground train station, the fire volume is 15 MW and the fire broke out at the center of the train, a visibility reduction degree on a respiration safety line for evaluating the smoke venting performance was analyzed and compared with a time taken to reduce the visibility to 10 m or less, which is an evacuation limit condition. According to the CFD analysis result, in Case- 1 , the visibility on the respiration safety line in the main-line section of the underground train station was 10 m or less after the laps of 725 seconds. However, in Case- 2 , the visibility of 10 m or less was not demonstrated even after the laps of 1020 seconds. Therefore, when the APS according to the present invention is employed, refugees&#39; safety can be increased by preventing smoke from being propagated in an event of a fire. 
     Although exemplary embodiments of the present invention have been described in detail hereinabove, it should be understood that many variations and modifications of the basic inventive concept herein described, which may appear to those skilled in the art, will still fall within the spirit and scope of the exemplary embodiments of the present invention as defined by the appended claims. 
     
       
         
           
               
             
               
                   
               
               
                 Reference numerals 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
            
               
                 1: Underground train train station 
                 2: Ventilating plant 
               
               
                 3: Main-line section 
                 10: Fast-train 
               
               
                 20: Slow train 
                 100: Pressure sensor 
               
               
                 102: Fire-detecting device 
                 104: Air supplying and venting fan 
               
               
                 106: Control panel 
                 110: Fast-train running space 
               
               
                 112: First air-stream out- and in-flow 
                 119: Partition wall 
               
               
                 space 
                   
               
               
                 120: Slow-train running space 
                 122: Second air-stream out- and 
               
               
                   
                 in-flow space 
               
               
                 130: Firs port 
                 131: Seond port 
               
               
                 132: First damper 
                 133: Second damper 
               
               
                 135: Third port 
                 136: Fourth port