Abstract:
A packaged engine working machine is provided. The machine includes an electrical component containing space partitioned into two spaces and a cooling air intake port. An engine disposed in the lower space of a package and electrical components disposed in the upper space, the upper space being partitioned into a high heat generation chamber containing high heat components, a low heat generation chamber containing low heat components, and an intake fan chamber provided with an intake fan for drawing outside air through the intake port. A high heat generation chamber cooling path and a low hear generation chamber cooling part are provided in which outside air reaching the intake fan chamber passes through the chambers via first, second and third communication ports.

Description:
TECHNICAL FIELD 
     The present invention relates to a packaged engine working machine in which an engine, a working machine driven by the engine, and electrical components for the engine and the working machine are stored inside a package. 
     BACKGROUND ART 
     A packaged engine working machine is known as a cogeneration apparatus in which a generator and/or a refrigerant compressor serving as working machine(s) are/is driven by an engine to perform electric power generation and/or heat pump air conditioning and to produce warm water by utilizing exhaust heat generated in electric power generation and/or heat pump air conditioning. Such a packaged engine working machine is adapted so that an engine, a working machine driven by the engine, and electrical components for the engine and the working machine are stored inside a package. 
     For example, Patent Document 1 discloses an electrical component box for an outdoor unit adapted so that an inner space of the electrical component box for storing electrical components are partitioned into two spaces. 
     PRIOR ART REFERENCE 
     Patent Document 
     Patent Document 1: Japanese Patent Application Laid-open No. 2000-88281 
     SUMMARY 
     Technical Problem 
     The electrical component box disclosed in Patent Document 1 is adapted so as to be partitioned by a composite molded substrate into: an upper space in which low current circuit components such as a microcomputer and a peripheral circuit component, etc., are disposed; and a lower space in which high current circuit components such as a power relay and a choke coil, etc., are disposed. Right walls of upper and lower lids of the electrical component box are provided with an outside air inlet for the upper space and an outside air inlet for the lower space, respectively, and a lower left wall of the lower lid is provided with an outside air outlet. 
     In the electrical component box disclosed in Patent Document 1, the single outside air outlet is used for both of the lower space and the upper space, while the two outside air inlets are separately used for the lower space and the upper space. Therefore, in the electrical component box disclosed in Patent Document 1, a filter has to be disposed for each of the two outside air inlets, which disadvantageously increases the number of assembly steps and the number of maintenance steps for the filters, and thus contributes to cost increase. 
     Accordingly, the present invention solves the above-mentioned technical problems by providing a packaged engine working machine adapted so that an electrical component storage space for storing electrical components is partitioned into two spaces but a cooling air intake port is provided at a single position in a concentrated manner. 
     Solution to the Problems 
     To solve the above-mentioned technical problems, the present invention provides the following packaged engine working machine. 
     Specifically, a packaged engine working machine according to Claim  1  of the present invention is a packaged engine working machine in which an engine and a working machine driven by the engine are disposed in a lower space of a package, and electrical components for the engine and the working machine are disposed in an upper space of the package, wherein the upper space is partitioned into: a high heat generation chamber in which high heat generation components included in the electrical components are collectively disposed; a low heat generation chamber in which low heat generation components included in the electrical components and having amounts of heat smaller than those of the high heat generation components are collectively disposed; and an intake fan chamber provided with an intake fan for sucking outside air through a single intake port provided in a panel constituting a wall surface of the high heat generation chamber, wherein the high heat generation chamber and the low heat generation chamber are extended in a longitudinal direction of the upper space and adjacent to each other in a width direction of the upper space, and the intake fan chamber is adjacent to the high heat generation chamber and the low heat generation chamber, wherein a first wall serving as a partition between the high heat generation chamber and the intake fan chamber includes a first communication port through which the high heat generation chamber and the intake fan chamber are communicated with each other, wherein a second wall serving as a partition between the high heat generation chamber and the low heat generation chamber includes a second communication port through which the high heat generation chamber and the low heat generation chamber are communicated with each other, wherein a third wall serving as a partition between the low heat generation chamber and the intake fan chamber includes a third communication port through which the low heat generation chamber and the intake fan chamber are communicated with each other, and wherein the packaged engine working machine includes: a high heat generation chamber cooling path through which the outside air from the intake port reaches the intake fan chamber via the high heat generation chamber and the first communication port; and a low heat generation chamber cooling path through which the outside air from the intake port reaches the intake fan chamber via the high heat generation chamber, the second communication port, the low heat generation chamber and the third communication port. 
     In the packaged engine working machine according to Claim  2  of the present invention, the high heat generation chamber cooling path is shorter than the low heat generation chamber cooling path. 
     In the packaged engine working machine according to Claim  3  of the present invention, the low heat generation chamber is disposed in a front of the packaged engine working machine. 
     In the packaged engine working machine according to Claim  4  of the present invention, the intake port is provided at a position distant from the intake fan chamber. 
     In the packaged engine working machine according to Claim  5  of the present invention, the first communication port is provided close to the first wall. 
     In the packaged engine working machine according to Claim  6  of the present invention, the second communication port is provided at a position distant from the intake fan chamber. 
     In the packaged engine working machine according to Claim  7  of the present invention, the third communication port is provided at a position distant from the second communication port. 
     Advantageous Effects of the Invention 
     In the invention according to Claim  1 , the outside air sucked through the single intake port is diverted as an airflow flowing through the high heat generation chamber cooling path and an airflow flowing through the low heat generation chamber cooling path, and then the diverted airflows are merged in the intake fan chamber. Since it is only necessary to dispose a single filter for the single intake port, the number of assembly steps and the number of maintenance steps for the filter can be reduced, thus achieving the effect of enabling cost reduction. 
     When the same quantity of air flows to the high heat generation chamber cooling path and the low heat generation chamber cooling path, pressure loss that occurs during flowing of the outside air through the cooling path is reduced in the shorter cooling path, thus increasing the resulting cooling effect. Accordingly, in the invention according to Claim  2 , the high heat generation chamber cooling path is shorter in length than the low heat generation chamber cooling path that extends via, for example, the second communication port, thus achieving the effect of more effectively cooling the high heat generation components disposed in the high heat generation chamber. 
     A working surface is disposed in the front in a usual layout, but when the high heat generation chamber is disposed in the front, an operator might mistakenly come into contact with the high heat generation chamber. The invention according to Claim  3  achieves the effect of preventing the operator from mistakenly coming into contact with the high heat generation chamber. 
     In the invention according to Claim  4 , the intake port is located at a position distant from the intake fan chamber, thus achieving the effect of ensuring the longest possible cooling path in each of the high heat generation chamber and the low heat generation chamber, and the effect of cooling the high heat generation components and the low heat generation components disposed in the high heat generation chamber and the low heat generation chamber, respectively, as uniformly as possible. 
     In the invention according to Claim  5 , the outside air flowing through the high heat generation chamber will flow along the first wall, thus achieving the effect of cooling the high heat generation components, disposed in the high heat generation chamber, as uniformly as possible. 
     In the invention according to Claim  6 , the inlet through which the outside air is introduced into the low heat generation chamber is far away from the intake fan chamber, thus achieving the effect of cooling the low heat generation components, disposed in the low heat generation chamber, as uniformly as possible. 
     In the invention according to Claim  7 , the inlet through which the outside air is introduced into the low heat generation chamber and the outlet through which the outside air is discharged from the low heat generation chamber are farther away from each other, thus achieving the effect of cooling the low heat generation components, disposed in the low heat generation chamber, as uniformly as possible. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an overall front perspective view illustrating a cogeneration apparatus according to one embodiment of the present invention. 
         FIG. 2  is an overall rear perspective view illustrating the cogeneration apparatus. 
         FIG. 3  is a front view illustrating an inner structure of the cogeneration apparatus. 
         FIG. 4  is a plan view illustrating the inner structure of the cogeneration apparatus. 
         FIG. 5  is a rear view illustrating the inner structure of the cogeneration apparatus. 
         FIG. 6  is a right side view illustrating the inner structure of the cogeneration apparatus. 
         FIG. 7  is a left side view illustrating the inner structure of the cogeneration apparatus. 
         FIG. 8  is a front perspective view schematically illustrating an upper space of the cogeneration apparatus. 
         FIG. 9  is a front view schematically illustrating the upper space of the cogeneration apparatus. 
         FIG. 10  is a top view schematically illustrating the upper space of the cogeneration apparatus. 
         FIG. 11  is a front perspective view schematically illustrating a low heat generation chamber in the upper space of the cogeneration apparatus. 
         FIG. 12  is a rear perspective view schematically illustrating a high heat generation chamber in the upper space of the cogeneration apparatus. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     Hereinafter, a cogeneration apparatus  1  serving as a packaged engine working machine according to one embodiment of the present invention will be described in detail with reference to  FIGS. 1 to 12 . Note that the cogeneration apparatus  1  is a system in which an electric power transmission line to an electric power consumption device (load) is connected with a commercial power line for an external commercial power source and an electric power generation power line for a generator so as to cover the demand for electric power for the load and so as to recover exhaust heat incident to electric power generation to utilize the recovered heat. 
     As illustrated in  FIGS. 1 and 2 , the cogeneration apparatus  1  includes a substantially rectangular parallelepiped package (housing)  2 . As illustrated in  FIG. 2 , an outer surface of the package  2  is covered with a plurality of panels. A right side lower panel  10   a  is provided with a ventilation intake port  39   a , a right side upper panel  10   b  is provided with a ventilation exhaust port  39   b , and a rear upper panel  10   c  is provided with an engine intake port  39   c  and an electrical component cooling intake port  39   d . These air vents  39   a ,  39   b ,  39   c  and  39   d  each include a louver, perforated metal or a mesh. 
     As illustrated in  FIG. 3  and  FIGS. 5 to 7 , an inside of the package  2  is divided into two spaces, i.e., an upper space  3  and a lower space  4 , by a middle wall  20  (illustrated in  FIG. 4 ) located somewhere along a vertical direction of the package  2 . As illustrated in  FIGS. 4 to 7 , the upper space  3  is partitioned by dividing walls into an intake chamber  31 , a high heat generation chamber  33 , a low heat generation chamber  34 , an intake fan chamber  35  and a device storage chamber  38 . As illustrated in  FIG. 5 , an intake silencer  13  having an intake port  13   a  is disposed in the intake chamber  31 . Another intake silencer  13  communicated with the intake silencer  13  in the intake chamber  31  is disposed in the high heat generation chamber  33 ; in addition, high heat generation components included in electrical components for an engine  5  and a generator  6  are collectively disposed in the high heat generation chamber  33 . As illustrated in  FIGS. 3 to 6 , low heat generation components included in the electrical components for the engine  5  and the generator  6  are collectively disposed in the low heat generation chamber  34 , and a mist separator  8  and a cooling water tank  11  are disposed in the device storage chamber  38 . 
     As illustrated in  FIG. 3 , the engine  5 , the generator  6 , an air cleaner  12 , an intake silencer  14 , a starting transformer (starter)  15 , a cooling water pump  16  and a drain filter  17  are disposed in the lower space  4 . As illustrated in  FIG. 5 , an exhaust silencer  19  and an exhaust gas heat exchanger  22  are disposed in the lower space  4 . As illustrated in  FIG. 6 , a ventilation duct  60  and a water-water heat exchanger  21  are disposed in the lower space  4 . As illustrated in  FIG. 7 , a storage box  50  is disposed in the lower space  4 . Note that a gas engine, for example, is used as the engine  5 . A crankshaft of the engine  5  is driven and rotated, which rotates a generator shaft of the generator  6  serving as a working machine, and thus generates electric power. 
     The above-mentioned water-water heat exchanger  21  and exhaust gas heat exchanger  22  serve to produce warm water by utilizing heat generated from the engine  5 . As illustrated in  FIGS. 3 ,  5  and  6 , a water supply port  9   a  through which cold water is supplied to the heat exchangers  21  and  22 , and a warm water outlet  9   b  through which warm water produced by the heat exchangers  21  and  22  is taken out are disposed vertically side by side at a right lateral surface of the lower space  4 . 
     The storage box  50  illustrated in  FIG. 7  stores, as a non-heat-generating electrical component, at least one of a terminal block  53 , a relay, a fuse and a breaker. As illustrated in  FIG. 3 , three external wiring holes  18  through which external input wires and external output wires are connected to, for example, the terminal block  53  of the storage box  50  are disposed vertically side by side at an upper left end portion of the lower space  4 . 
     As illustrated in  FIG. 4 , an air vent  37  through which the upper space  3  and the lower space  4  are communicated with each other vertically is provided in a substantially center region of the middle wall  20 . Outside air taken into the lower space  4  from the ventilation intake port  39   a  through the ventilation duct  60  flows upward while cooling the engine  5 , etc., flows into the device storage chamber  38  of the upper space  3  through the air vent  37 , and is then discharged to an outside space from the ventilation exhaust port  39   b.    
     Next, referring to  FIGS. 8 to 12 , how the high heat generation chamber  33  and the low heat generation chamber  34  are provided in the upper space  3  will be described in detail. Note that a second wall  78  is not illustrated in  FIGS. 11 and 12 . 
     As illustrated in  FIG. 8 , an inside of the upper space  3  is partitioned by a plurality of wall bodies into: the high heat generation chamber  33  disposed in a left region of the upper space  3  and close to its rear in plan view; the low heat generation chamber  34  disposed in a front of the upper space  3  from its left region to its center region; the intake chamber  31  disposed rearward of the center region; the air vent  37  (illustrated in  FIG. 10 ) disposed in the center region and forward of the intake chamber  31 ; the intake fan chamber  35  disposed in the center region and forward of the air vent  37 ; and the device storage chamber  38  disposed in a right region of the upper space  3 . 
     The high heat generation chamber  33  is defined by the rear upper panel  10   c , a left side upper panel  10   e , a first wall  70 , and the second wall  78 . The low heat generation chamber  34  is defined by a front upper panel  10   d , the left side upper panel  10   e , the first wall  70 , and a third wall  79 . 
     The high heat generation chamber  33  and the low heat generation chamber  34  are extended in a right-left direction of the upper space  3 , and are adjacent to each other in a front-rear direction thereof. A length of the low heat generation chamber  34  in the right-left direction is longer than that of the high heat generation chamber  33  in the right-left direction, and the intake fan chamber  35  is disposed adjacent to a rear of the low heat generation chamber  34  on the right of the high heat generation chamber  33 . Note that in this example, the right-left direction is defined as a longitudinal direction, and the front-rear direction is defined as a width direction. 
     In this example, when the high heat generation chamber  33  is disposed rearward of the low heat generation chamber  34  and a front surface serving as a working surface is opened, an operator is prevented from mistakenly coming into contact with the high heat generation chamber  33 . 
     As illustrated in  FIG. 10 , the electrical component cooling intake port  39   d  is provided in a left portion of the rear upper panel  10   c , and a dust-proof filter  32  is disposed inward of the rear upper panel  10   c . Accordingly, outside air F is introduced into the high heat generation chamber  33  through the electrical component cooling intake port  39   d  and the dust-proof filter  32 . The electrical component cooling intake port  39   d  is disposed as far away from the intake fan chamber  35  as possible, thus making it possible to ensure the longest possible cooling path; hence, as illustrated in  FIG. 10 , the electrical component cooling intake port  39   d  is preferably disposed close to a left end of the upper space  3  in plan view. For the sake of clarity of the high heat generation chamber  33 , the intake silencer  13 , and a utility box  13   b  used to support or fix the intake silencer  13  and to store an additional device are not illustrated in  FIGS. 8 and 10 . The intake silencer  13  is illustrated in  FIGS. 4 and 5 , and the utility box  13   b  is illustrated in  FIGS. 4 and 7 . 
     The left region of the upper space  3  is partitioned, by the first wall  70  extended in the right-left direction, into the high heat generation chamber  33  located in the rear of the upper space  3 , and the low heat generation chamber  34  located in the front of the upper space  3 . As illustrated in  FIG. 11 , the first wall  70  includes a lower vertical plate  71 , a horizontal plate  72  and an upper vertical plate  73 , and the upper vertical plate  73  is disposed forward of the lower vertical plate  71  so that the first wall  70  has a stepped shape. 
     Electrical components that generate a small amount of heat, i.e., low heat generation components, such as an ignition circuit board  86 , a control circuit board  87 , a relay  93 , a capacitor  94  and a relay  95  are placed on a front side of the lower vertical plate  71  which is included in the low heat generation chamber  34 . Similarly, electrical components that generate a small amount of heat, i.e., low heat generation components, such as a working circuit board  88 , a power source circuit board  89 , a noise filter  91  and a breaker  92  are placed on a front side of the upper vertical plate  73  which is included in the low heat generation chamber  34 . 
     As described above, the components such as the operation circuit board  88  and the breaker  92  are placed on the front side of the upper vertical plate  73  located forward of the lower vertical plate  71 , thus allowing an operator to operate these devices with ease. 
     As illustrated in  FIG. 12 , electrical components that generate a large amount of heat, i.e., high heat generation components, such as a DC reactor  81  and power source transformers  83  are placed on an upper surface of the horizontal plate  72  which is included in the high heat generation chamber  33 . Similarly, an electrical component that generates a large amount of heat, i.e., a high heat generation component, such as a rectifier  82  is placed on a rear side of the lower vertical plate  71  which is included in the high heat generation chamber  33 . Furthermore, electrical components that generate a large amount of heat, i.e., high heat generation components, such as regulators  84  are placed on a left lateral surface of the second wall  78  (illustrated in  FIG. 8 ) which is included in the high heat generation chamber  33 . 
     As illustrated in  FIG. 10 , the left region of the upper space  3  is partitioned into the high heat generation chamber  33  and the intake fan chamber  35  by the second wall  78  extended in the front-rear direction. Toward a front end  78   a  of the second wall  78  which is a front extremity thereof, an upper portion of the second wall  78  partially bites into the horizontal plate  72 . A gap is provided between the front end  78   a  and the upper vertical plate  73 . This gap is a first communication port  74  through which the high heat generation chamber  33  and the intake fan chamber  35  are communication with each other. 
     As illustrated in  FIG. 12 , a second communication port  75  is provided in a lower region of a left end portion of the lower vertical plate  71  of the first wall  70 . The high heat generation chamber  33  and the low heat generation chamber  34  are communicated with each other through the second communication port  75 . 
     As illustrated in  FIG. 10 , the upper vertical plate  73  of the first wall  70  is extended in the right-left direction, and a gap is provided between the third wall  79  and a right end  73   a  of the upper vertical plate  73  serving as a right extremity thereof. This gap is a third communication port  76  through which the low heat generation chamber  33  and the intake fan chamber  35  are communicated with each other. 
     The intake fan chamber  35  is a space defined by: the second wall  78  serving as a partition between the intake fan chamber  35  and the high heat generation chamber  33 ; the first wall  70  serving as a partition between the intake fan chamber  35  and the low heat generation chamber  34 ; the third wall  79  serving as a partition between the intake fan chamber  35  and the device storage chamber  38 ; and a fan support plate  36   a  to which an intake fan  36  is attached. The fan support plate  36   a  is fixed to a right surface of the second wall  78 , a left surface of the third wall  79  and the upper surface of the horizontal plate  72 . The intake fan  36  is attached to a rear side of the fan support plate  36   a . A plate-like fan cover  90  is provided rearward of the intake fan  36  at a distance therefrom. A negative pressure produced by the intake fan  36  causes the outside air F to be sucked into the intake fan chamber  35  via high heat generation chamber cooling path Q and a low heat generation chamber cooling path R which will be described below. 
     The high heat generation chamber cooling path Q includes a path Q 1  in the high heat generation chamber  33 , a path Q 2  in the first communication port  74  and a path Q 3  in the intake fan chamber  35 , and thus serves as a path through which the high heat generation components are cooled by the outside air F sucked by the intake fan  36 . 
     The low heat generation chamber cooling path R includes a path R 1  in the high heat generation chamber  33 , a path R 2  in the second communication port  75 , a path R 3  in the low heat generation chamber  34 , a path R 4  in the third communication port  76  and a path R 5  in the intake fan chamber  35 , and thus serves as a path through which the low heat generation components are cooled by the outside air F sucked by the intake fan  36 . 
     Note that as illustrated in  FIG. 9 , the second communication port  75  (disposed in a lower left corner) through which the outside air F is introduced into the low heat generation chamber  34  and the third communication port  76  (disposed in an upper right corner) through which the outside air F is discharged from the low heat generation chamber  34  are disposed diagonally away from each other; therefore, the longer path R 3  can be ensured in the low heat generation chamber  34 , and thus the low heat generation components in the low heat generation chamber  34  can be cooled as uniformly as possible. 
     When a comparison is made between the high heat generation chamber cooling path Q and the low heat generation chamber cooling path R, a portion of the path R 3  in the low heat generation chamber  34  which is close to the third communication port  76  changes in length in accordance with the location and shape of the intake fan chamber  35 . However, the low heat generation chamber cooling path R makes a longer detour than the high heat generation chamber cooling path Q by at least the path R 2  in the second communication port  75  and the path R 4  in the third communication port  76 . When the same quantity of air flows to the high heat generation chamber cooling path Q and the low heat generation chamber cooling path R, pressure loss is reduced in the shorter cooling path, and therefore, cooling air flows to the shorter cooling path in an unbalanced manner. Accordingly, the quantity of cooling air in the high heat generation chamber cooling path Q having a shorter length is larger than the quantity of cooling air in the low heat generation chamber cooling path R having a longer length, thus performing more effective cooling. 
     Next, how the outside air taken in from the electrical component cooling intake port  39   d  by a suction force of the intake fan  36  flows through the upper space  3  of the package  2  will be described. 
     As illustrated in  FIG. 10 , dust or the like contained in the outside air F taken in from the electrical component cooling intake port  39   d  is removed by the dust-proof filter  32 . Then, the outside air F is diverted as: a high heat generation chamber cooling diverted flow G that flows along the high heat generation chamber cooling path Q; and a low heat generation chamber cooling diverted flow H that flows along the low heat generation chamber cooling path R. 
     The high heat generation chamber cooling diverted flow G flows through the high heat generation chamber  33  from its rear toward its front to collide against the first wall  70 , and then flows along a rear surface of the high heat generation chamber  33  from the left to the right (i.e., the path R 1  in the high heat generation chamber  33 ), thus cooling the various high heat generation components placed in the high heat generation chamber  33  (e.g., the above-mentioned components such as the DC reactor  81 , the power source transformers  83 , the regulators  84  and the rectifier  82 ). The high heat generation chamber cooling diverted flow G which has cooled the high heat generation components and increased in temperature is introduced into the intake fan chamber  35  (i.e., the path Q 3  in the intake fan chamber  35 ) through the first communication port  74  (i.e., the path Q 2  in the first communication port  74 ). 
     Meanwhile, the low heat generation chamber cooling diverted flow H flows through the high heat generation chamber  33  from its rear to its front (i.e., the path R 1  in the high heat generation chamber  33 ), and is introduced into the low heat generation chamber  34  through the second communication port  75  of the first wall  70  (i.e., the path R 2  in the second communication port  75 ). The low heat generation chamber cooling diverted flow H introduced through a lower left end portion of the low heat generation chamber  34  flows along a front surface of the low heat generation chamber  34  from the left to the right (i.e., the path R 3  in the low heat generation chamber  34 ), thus cooling the various low heat generation components placed in the low heat generation chamber  34  (e.g., the above-mentioned components such as the ignition circuit board  86 , the control circuit board  87 , the relay  93 , the capacitor  94 , the relay  95 , the operation circuit board  88 , the power source circuit board  89 , the noise filter  91  and the breaker  92 ). The low heat generation chamber cooling diverted flow H which has cooled the low heat generation components and increased in temperature is introduced into the intake fan chamber  35  (i.e., the path R 5  in the intake fan chamber  35 ) through the third communication port  76  in an upper right end portion of the low heat generation chamber  34  (i.e., the path R 4  in the third communication port  76 ). 
     The high heat generation chamber cooling diverted flow G and the low heat generation chamber cooling diverted flow H, which have been introduced into the intake fan chamber  35 , merge into intake cooling air I. The intake cooling air I flows substantially horizontally through the intake fan chamber  35  from its front toward its rear, and then collides against the fan cover  90 ; thus, a flow direction of the intake cooling air I changes to a downward direction. The intake cooling air I, which flows downward, is merged with ventilation air of the lower space  4  flowing into the device storage chamber  38  from the air vent  37 , and is discharged into the outside space through the ventilation exhaust port  39   b  of the right side upper panel  10   b.    
     In the above-described embodiment, the outside air F sucked through the single electrical component cooling intake port  39   d  is diverted as the high heat generation chamber cooling diverted flow G flowing along the high heat generation chamber cooling path Q and the low heat generation chamber cooling diverted flow H flowing along the low heat generation chamber cooling path R, and these diverted flows G and H are merged in the intake fan chamber  35 . Since it is only necessary to dispose the single dust-proof filter  32  for the single intake port  39   d , the number of assembly steps and the number of maintenance steps for the dust-proof filter  32  can be reduced, thus achieving the effect of enabling cost reduction. 
     Note that layouts of various constituent elements in the above-described embodiment, i.e., locations of the first communication port  74 , the second communication port  75  and the third communication port  76 , forms of the first wall  70 , the second wall  78  and the third wall  79 , forms of the high heat generation chamber cooling path Q and the low heat generation chamber cooling path R, and types and locations of the high heat generation components and low heat generation components placed in the high heat generation chamber and low heat generation chamber, respectively, for example, are provided by way of example only, and are not limited to those described in the foregoing embodiment. 
     In view of the amount of heat generated by the placed electrical components and the suction force of the intake fan  36 , an opening area of each of the first communication port  74 , the second communication port  75  and the third communication port  76  is appropriately decided to bring the quantity of air into balance in such a manner that the temperature of each of the high heat generation components in the high heat generation chamber  33  and the low heat generation components in the low heat generation chamber  34 , respectively, will not exceed a given temperature. 
     The foregoing embodiment has been described on the assumption that the generator  6  is used as a working machine of the packaged engine working machine  1 ; however, when the packaged engine working machine  1  serves as an engine heat pump, a compressor is installed instead of the generator  6 . Alternatively, both of the generator  6  and compressor may be installed as working machines of the packaged engine working machine  1 . 
     DESCRIPTION OF THE REFERENCE CHARACTERS 
       1  cogeneration apparatus (packaged engine working machine) 
       2  package (housing) 
       3  upper space 
       4  lower space 
       5  engine 
       6  generator (working machine) 
       32  dust-proof filter 
       33  high heat generation chamber 
       34  low heat generation chamber 
       35  intake fan chamber 
       36  intake fan 
       39   d  electrical component cooling intake port 
       70  first wall 
       74  first communication port 
       75  second communication port 
       76  third communication port 
       78  second wall 
       79  third wall 
     F outside air 
     Q high heat generation chamber cooling path 
     R low heat generation chamber cooling path