JP5994809B2 - Impeller and hot water supply apparatus provided with the impeller - Google Patents

Description

  The present invention relates to an impeller and a hot water supply apparatus including the impeller.

  When replacing an installed hot water storage type hot water supply device with an instantaneous type hot water supply device, there is a site where the installed exhaust pipe cannot be removed from the viewpoint of maintaining the appearance of the building.

  In the field as described above, it is possible to cope with replacement of the hot water supply apparatus by leaving the existing exhaust pipe and inserting the exhaust pipe into the exhaust pipe. However, if the outer diameter of the exhaust pipe is large, the exhaust pipe cannot be installed in the exhaust cylinder, so it is necessary to reduce the diameter of the exhaust pipe. In order to maintain a stable combustion state even when the diameter of the exhaust pipe is reduced, it is necessary to employ an exhaust suction combustion system in the hot water supply apparatus.

  This exhaust suction combustion type hot water supply apparatus is disclosed in, for example, Japanese Patent Application Laid-Open No. 60-186617. In the hot water supply apparatus described in this publication, a heat exchanger for recovering sensible heat, a heat exchanger for recovering latent heat, and a fan are disposed downstream of the flow of combustion gas generated in the burner. Arranged in order. That is, in this type of hot water supply apparatus, the fan is disposed downstream of the flow of the combustion gas from the heat exchanger.

JP-A-60-186617

  In the exhaust suction combustion type hot water supply apparatus described above, the fan is disposed downstream of the heat exchanger. For this reason, the fan needs to suck the combustion gas after passing through the heat exchanger and discharge it to the hot water supply apparatus. In such a configuration, when the blowing power of the fan is not sufficient, the discharge of the combustion gas to the outside becomes unstable, which may lead to vibration combustion. For this reason, the suction force of the fan needs to be maintained sufficiently high.

  This invention is made | formed in view of said subject, The objective is to provide the impeller which can exhibit high ventilation power, and a hot water supply apparatus provided with the same.

  The impeller of the present invention includes a main plate having a first surface, a plurality of first blades extending from the inner peripheral side of the first surface to the outer peripheral side and protruding from the first surface, and the first surface A plurality of second blades extending from the inner peripheral side to the outer peripheral side and protruding from the first surface and provided on the inner peripheral side of the first blade. The length obtained by subtracting the radius of the virtual first inscribed circle connecting the inner ends of the plurality of first blades from the radius of the virtual first circumscribed circle connecting the outer ends of the plurality of first blades is first. The height in the protruding direction of the second blade is larger than the radius of the inscribed circle, and is smaller than the height in the protruding direction of the inner end portion of the first blade.

  The impeller of the present invention has a plurality of first blades from the radius of a virtual first circumscribed circle that has a plurality of first blades on the first surface of the main plate and connects the outer ends of the plurality of first blades. The length obtained by subtracting the radius of the virtual first inscribed circle connecting the inner ends of the first inscribed circle is larger than the radius of the first inscribed circle. For this reason, it has the ventilation capability which sends out gas toward the outer peripheral side from the inner peripheral side. Furthermore, the 2nd blade | wing with which the impeller of this invention is provided in the position where the ventilation force of a 1st blade | wing does not reach easily, in such a position, it is gas from the inner edge part side to the outer edge part side of a 2nd blade | wing The blasting force to send out can be demonstrated. Therefore, according to the impeller of this invention, since it can have the high capability which discharges | emits gas from the inner peripheral side of the 1st surface to the outer peripheral side, it can exhibit a high ventilation power.

  In the impeller, the height of the second blade in the protruding direction is preferably not more than half the height of the inner end of the first blade in the protruding direction. Thereby, it can suppress that a 2nd blade | wing becomes air intake resistance with respect to the gas attracted | sucked between the inner edge parts of the 1st blade | wing adjacent by the ventilation force of a 1st blade | wing.

  In the impeller, on the first surface, it is preferable that a virtual second circumscribed circle connecting outer end portions of the plurality of second vanes is located on the inner peripheral side of the first inscribed circle. Thereby, it can suppress that a 2nd blade | wing becomes air intake resistance with respect to the gas attracted | sucked between the inner edge parts of the 1st blade | wing adjacent by the ventilation force of a 1st blade | wing.

  In the impeller, the height of the first blade in the protruding direction is preferably continuously reduced from the inner end portion of the first blade toward the outer end portion of the first blade. Thereby, while the ventilation force of a 1st blade | wing improves, the effect by the ventilation force of a 2nd blade | wing can be heightened.

  In the impeller, it is preferable that a virtual extension line formed by extending the outer end portion of the second blade in the extending direction is located between adjacent inner end portions of the first blade. Thereby, it can suppress that the gas sent out to the outer-end part side of the 2nd blade | wing by the ventilation force of the 2nd blade | wing collides with the inner-end part of a 1st blade | wing, and suppresses generation | occurrence | production of a noise. Can do.

  In the impeller, the first blade is located on the outer peripheral side of the curved extended region, the curved extended region extending from the inner peripheral side to the outer peripheral side of the first surface, and the first surface. It is preferable that the linearly extending region extends linearly from the inner peripheral side toward the outer peripheral side, and the extension line intersects the linearly extended region. In this case, after the gas sent out by the second blade reaches the curve extending region of the first blade, it is discharged so as to go to the outer end side of the first blade along the side surface of the first blade. It becomes. Near the side surface of the first blade, there is a tendency that a gas flow (back flow) from the outer peripheral side to the inner peripheral side of the first surface tends to occur, but the occurrence of this reverse flow can be suppressed by the blowing force of the second blade. .

  In the impeller, the height in the protruding direction of the second blade is preferably continuously reduced from the inner end portion of the second blade toward the outer end portion of the second blade. Thereby, the said impeller is further excellent in the ventilation force which sends out gas from the inner peripheral side of the 1st surface to the outer peripheral side.

  In the impeller, the number of second blades is preferably a divisor of the number of first blades. Thereby, the ventilation force of an impeller can be made uniform on the 1st surface.

  The impeller preferably further includes a shroud that covers an end portion of the first blade in the protruding direction. Thereby, the ventilation force of a 1st blade | wing is further excellent.

  A hot water supply apparatus of the present invention includes a burner that generates combustion gas, a heat exchanger that heats hot water flowing through the heat exchange with the combustion gas, and hot water supply that sucks the combustion gas after passing through the heat exchanger. And a fan for discharging to the outside of the apparatus. The fan includes a fan case, an impeller housed in the fan case, a drive source attached to the fan case for driving the impeller, and a rotating shaft that connects the impeller and the drive source. This impeller is the above-described impeller.

  According to the hot water supply apparatus of the present invention, since the fan having the above-described impeller is provided, a high suction force can be provided. Therefore, the ability to suck the combustion gas after passing through the heat exchanger and discharge it to the hot water supply device is excellent.

  In the above hot water supply apparatus, the fan case has a back wall provided with a through hole, and the impeller extends from the inner peripheral side to the outer peripheral side of the second surface of the main plate opposite to the first surface. It further has a plurality of third blades provided so as to protrude from the second surface, and the second surface is disposed so as to face the back wall, and between the rotating shaft penetrating the through hole and the back wall, A gap is provided for sucking air outside the fan case into the fan case. Thereby, the gas outside the fan case can be caused to flow into the fan case by the blowing force of the third blade, and thus the fan can be cooled.

  ADVANTAGE OF THE INVENTION According to this invention, an impeller which can exhibit high suction | attraction force, and a hot water supply apparatus provided with the same can be provided.

It is a front view which shows roughly the structure of the hot water supply apparatus in one embodiment of this invention. It is a partial cross section side view which shows the structure of the hot water supply apparatus shown in FIG. It is a fragmentary sectional view which shows schematically the fan and exhaust box for demonstrating the structure of the fan of the hot water supply apparatus shown in FIG. It is a perspective view which shows roughly the structure of the impeller of the hot water supply apparatus shown in FIG. It is a side view which shows roughly the structure of the impeller of the hot water supply apparatus shown in FIG. It is sectional drawing which shows schematically the structure of the impeller of the hot water supply apparatus shown in FIG. It is a perspective view which shows roughly the structure of the 1st blade | wing and 2nd blade | wing which the impeller of the hot water supply apparatus shown in FIG. 1 has. It is a top view which shows roughly the structure of the 1st blade | wing and 2nd blade | wing which the impeller of the hot-water supply apparatus shown in FIG. 1 has. It is a top view which shows roughly the structure of the 1st blade | wing and 2nd blade | wing which the impeller of the hot-water supply apparatus shown in FIG. 1 has. It is a partial top view which shows roughly the structure of the 1st blade | wing and 2nd blade | wing which the impeller of the hot water supply apparatus shown in FIG. 1 has. It is a top view which shows roughly the structure of the 3rd blade | wing which the impeller of the hot-water supply apparatus shown in FIG. 1 has. It is the schematic which shows typically the air flow which generate | occur | produces on the 1st surface side with an impeller.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the drawings, the same reference numerals represent the same or corresponding parts. In addition, dimensional relationships such as length, width, thickness, and depth are changed as appropriate for clarity and simplification of the drawings, and do not represent actual dimensional relationships.

  The structure of the hot water supply apparatus in one embodiment of the present invention will be described with reference to FIGS. In each figure, the same element is denoted by the same reference numeral, and the description thereof is not repeated.

  Referring mainly to FIGS. 1 and 2, hot water supply apparatus 100 of the present embodiment is an exhaust suction combustion type latent heat recovery type hot water supply apparatus. The hot water supply apparatus 100 includes a housing 1, a burner 2, a primary heat exchanger 3, a secondary heat exchanger 4, an exhaust box 5, a fan 6, an exhaust pipe 7, a drain tank 8, and a pipe. 9 to 15 mainly.

  The burner 2 is for generating combustion gas by burning fuel gas. A gas supply pipe 10 is connected to the burner 2. The gas supply pipe 10 is for supplying fuel gas to the burner 2. For example, a gas valve (not shown) made of an electromagnetic valve is attached to the gas supply pipe 10.

  Above the burner 2, a spark plug 2a is arranged. The spark plug 2a is for generating a flame in the fuel-air mixture jetted from the burner 2 by generating an ignition spark with a target (not shown) provided in the burner 2. is there. The burner 2 generates heat by burning the fuel gas supplied from the gas supply pipe 10 (this is called combustion operation).

  Referring mainly to FIG. 2, the primary heat exchanger 3 is a sensible heat recovery type heat exchanger. The primary heat exchanger 3 mainly includes a plurality of plate-like fins 3b, a heat transfer tube 3a that penetrates the plurality of plate-like fins 3b, and a case 3c that accommodates the fins 3b and the heat transfer tubes 3a therein. Have. The primary heat exchanger 3 performs heat exchange with the combustion gas generated in the burner 2, and specifically, in the heat transfer tube 3 a of the primary heat exchanger 3 by the amount of heat generated by the combustion operation of the burner 2. It is for heating the hot water flowing through.

  Referring mainly to FIG. 2, the secondary heat exchanger 4 is a latent heat recovery type heat exchanger. The secondary heat exchanger 4 is located downstream of the primary heat exchanger 3 in the flow of the combustion gas, and is connected to the primary heat exchanger 3 in series with each other. Thus, since the hot water supply apparatus 100 of this Embodiment has the latent heat recovery type secondary heat exchanger 4, it is a latent heat recovery type hot water supply apparatus.

  The secondary heat exchanger 4 mainly has a drain outlet 4a, a heat transfer tube 4b, a side wall 4c, a bottom wall 4d, and an upper wall 4g. The heat transfer tubes 4b are stacked by being spirally wound. The side wall 4c, the bottom wall 4d, and the upper wall 4g are arranged so as to surround the periphery of the heat transfer tube 4b.

  In the secondary heat exchanger 4, hot water flowing in the heat transfer pipe 4 b is preheated (heated) by heat exchange with the combustion gas after heat exchange in the primary heat exchanger 3. In this process, the temperature of the combustion gas is lowered to about 60 ° C., so that moisture contained in the combustion gas is condensed and latent heat can be obtained. Further, the latent heat is recovered by the secondary heat exchanger 4 and the moisture contained in the combustion gas is condensed to generate drain.

  The bottom wall 4 d is for partitioning between the primary heat exchanger 3 and the secondary heat exchanger 4, and is also an upper wall of the primary heat exchanger 3. An opening 4e is provided in the bottom wall 4d, and a space in which the heat transfer tube 3a of the primary heat exchanger 3 is arranged by this opening 4e and a space in which the heat transfer tube 4b of the secondary heat exchanger 4 is arranged. And communicate with each other.

  As shown by the white arrow in FIG. 2, the combustion gas can flow from the primary heat exchanger 3 to the secondary heat exchanger 4 through the opening 4 e. In this embodiment, for simplicity, the bottom wall 4d of the secondary heat exchanger 4 and the upper wall of the primary heat exchanger 3 are shared, but the primary heat exchanger 3 and the secondary heat exchanger 4 are the same. An exhaust collecting member may be connected between the two.

  An opening 4h is provided in the upper wall 4g, and the space in which the heat transfer tube 4b of the secondary heat exchanger 4 is arranged communicates with the internal space of the exhaust box 5 through the opening 4h. As indicated by white arrows in FIG. 2, the combustion gas can flow from the secondary heat exchanger 4 into the internal space of the exhaust box 5 through the opening 4 h.

  The drain outlet 4a is provided in the side wall 4c or the bottom wall 4d. This drain outlet 4a is the lowest position in the space surrounded by the side wall 4c, the bottom wall 4d, and the upper wall 4g (the lowest position in the vertical direction in the installed state of the hot water supply device), and is the lowest position of the heat transfer tube 4b. It opens below the lower end. As a result, the drain generated in the secondary heat exchanger 4 can be guided to the drain outlet 4a through the bottom wall 4d and the side wall 4c as shown by black arrows in FIG.

  Referring mainly to FIGS. 2 and 3, the exhaust box 5 constitutes a flow path of the combustion gas between the secondary heat exchanger 4 and the fan 6. With this exhaust box 5, it is possible to guide the combustion gas after heat exchange in the secondary heat exchanger 4 to the fan 6. The exhaust box 5 is attached to the secondary heat exchanger 4 and is located downstream of the secondary heat exchanger 4 in the flow of the combustion gas.

  The exhaust box 5 mainly has a box body 5a and a fan connection portion 5b. The internal space of the box body 5a communicates with the internal space where the heat transfer tube 4b of the secondary heat exchanger 4 is disposed through the opening 4h of the secondary heat exchanger 4. The fan connection portion 5b is provided so as to protrude from the upper portion of the box body 5a. The fan connecting portion 5b has, for example, a cylindrical shape, and the internal space 5ba communicates with the internal space of the box body 5a.

  Referring mainly to FIG. 1 and FIG. 3, the fan 6 mainly has a fan case 61, an impeller 62, a drive source 63, and a rotating shaft 64. The fan 6 is for sucking the combustion gas after passing through the secondary heat exchanger 4 (heat exchanged in the secondary heat exchanger 4) and discharging it to the outside of the hot water supply apparatus 100. It is connected to the exhaust pipe 7 located outside the 100.

  This fan 6 is located downstream of the exhaust box 5 and the secondary heat exchanger 4 in the flow of the combustion gas. That is, in the hot water supply device 100, the burner 2, the primary heat exchanger 3, the secondary heat exchanger 4, the exhaust box 5, and the fan 6 are arranged in order from the upstream side to the downstream side of the flow of combustion gas generated in the burner 2. Are lined up. In this arrangement, since the combustion gas is sucked and exhausted by the fan 6 as described above, the hot water supply device 100 of the present embodiment is an exhaust suction combustion type hot water supply device.

  Referring mainly to FIG. 3, the fan case 61 mainly has a back wall 61a provided with a through hole 61c and a peripheral wall 61b surrounding the back wall 61a, and the impeller 62 is rotated in the internal space 61d. Accommodate as possible. In FIG. 3, the back wall 61a and the peripheral wall 61b are formed of different members, but the back wall 61a and the peripheral wall 61b may be integrally formed.

  Referring mainly to FIGS. 3 to 10, an impeller 62 includes a disk-shaped main plate 62a, a plurality of first blades 62b, a plurality of second blades 62c, a plurality of third blades 62d, and a shroud 62e. And has mainly. The main plate 62a has a first surface 62aa and a second surface 62ab opposite to the first surface 62aa, and the first blade 62b and the second blade 62c are provided on the first surface 62aa. A third blade 62d is provided on the second surface 62ab.

  Referring mainly to FIGS. 6 to 9, the first blade 62 b is formed to extend from the inner peripheral side of the first surface 62 aa toward the outer peripheral side and protrude from the first surface 62 aa. The first blades 62b are individually provided on the first surface 62aa and do not contact each other. 7 and 8 show the impeller 62 from which the shroud 62e is omitted in order to facilitate understanding of the configuration of the first blade 62b and the second blade 62c.

  As shown in FIG. 6, the height of the first blade 62b in the protruding direction continuously decreases from the inner end portion 62bb of the first blade 62b toward the outer end portion ba. In particular, in the present embodiment, a curved region in which the height in the protruding direction of the first blade 62b decreases in a curved manner (relatively abruptly) from the inner end portion 62bb of the first blade 62b toward the outer end portion 62ba. A and a linear region B that is positioned on the outer peripheral side of the curved region A and linearly (relatively and gently) decreases linearly from the inner peripheral side to the outer peripheral side of the first surface 62aa. The width of the curved area A is smaller than the width of the curved area B (see, for example, FIG. 6).

  As shown in FIG. 8, the first blade 62 b is formed from the inner peripheral side of the first surface 62 aa when the first surface 62 aa is viewed from the axial direction of the rotation shaft 64 (A axis indicated by a one-dot chain line in FIG. 3). A curve extending region C that extends in a curved manner toward the outer peripheral side, and is positioned on the outer peripheral side from the curved extending region C and extends linearly from the inner peripheral side to the outer peripheral side of the first surface 62aa. And a linearly extending region D. The bending direction of the curve extending region C is the same as the rotation direction of the impeller 62 (the direction indicated by the arrow in FIG. 8).

  Here, as shown in FIG. 9, a first circumscribed circle E that connects the outer end portions 62ba of the plurality of first blades 62b and a first inscribed circle F that connects the inner end portions 62bb of the plurality of first blades are hypothesized. . On the first surface aa, the length obtained by subtracting the radius of the first inscribed circle F from the radius of the first circumscribed circle E is larger than the radius of the first inscribed circle F. In the present embodiment, since the first blade 62b extends to the outer end of the main plate 62a, the first circumscribed circle E coincides with the outer end of the main plate 62a.

  Referring mainly to FIG. 6 to FIG. 9, the second blade 62 c extends from the inner peripheral side of the first surface 62 aa toward the outer peripheral side and is formed so as to protrude from the first surface 62 aa. The second blades 62c are individually provided on the first surface 62aa and do not contact each other. The second blade 62c is provided on the inner peripheral side of the first surface 62aa than the first blade 62b.

  The height of the second blade 62c in the protruding direction continuously decreases from the inner end 62cb to the outer end ca of the second blade 62c, and the height of the second blade 62c in the protruding direction is the first blade. It is smaller than the height in the protruding direction of the inner end 62bb of 62b. In the present specification, the height in the protruding direction of the second blade 62c means all the heights in the protruding direction of the second blade 62c unless the position is particularly defined.

  Further, as shown in FIG. 8, the second blade 62 c has an inner surface of the first surface 62 aa when the first surface 62 aa is viewed from the axial direction of the rotation shaft 64 (A-axis indicated by a one-dot chain line in FIG. 3). It extends linearly from the circumferential side toward the outer circumferential side, and the number of second blades 62c is a divisor of the number of first blades 62b.

  Here, as shown in FIG. 9, a second circumscribed circle G connecting the outer end portions 62ca of the plurality of second blades 62c is assumed. In this case, on the first surface 62aa, the second circumscribed circle G is located on the inner peripheral side with respect to the first inscribed circle F described above.

  Further, as shown in FIG. 10, an extension line H formed by extending the outer end portion 62 ca of the second blade 62 c in the extending direction of the second blade 62 c is assumed. On the first surface 62aa, the extension line H passes between adjacent inner end portions 62bb of the first blades 62b. Furthermore, the extension line H located between two adjacent first blades 62b is one of the first blades 62b positioned in the rotational direction (the direction in which the curve extending region C bends) of the two first blades 62b. Intersects the straight line extending region D.

  Referring mainly to FIGS. 4 to 6, the shroud 62 e is provided so as to be separated from the first surface 62 aa and to integrally cover the end portion of the first blade 62 b in the protruding direction, and at the central portion thereof. Has an opening 62ee. In the present embodiment, when the first surface 62aa is viewed from the axial direction of the rotation shaft 64, the entire second blade 62c can be looked down from the opening 62ee. This is because in the present embodiment, the position of the end of the opening 62ee substantially coincides with the position of the first inscribed circle F.

  In general, the shape of the “shroud” is formed along the height of the covering blades so as not to hinder the flow of gas passing between the blades. Therefore, in the hot water supply apparatus 100 of the present embodiment, the shroud 62e has a truncated cone shape with a narrowed slope so as to follow the change in the height of the first blade 62b.

  Referring mainly to FIGS. 4, 5 and 11, third blade 62 d extends from the inner peripheral side to the outer peripheral side of second surface 62 ab and is formed to protrude from second surface 62 ab. . The third blades 62d are individually provided on the second surface 62ab and do not contact each other. In the hot water supply apparatus 100 of the present embodiment, the height of the third blade 62d is constant.

  As shown in FIG. 3, the above-described impeller 62 is disposed in the fan case 61 so that the second surface 62ab of the main plate 62a faces the back wall 61a. Further, the opening 62ee of the shroud 62e is disposed so as to face the internal space 5ba.

  With the above configuration, the combustion gas is sucked into the fan case 61 from the box main body 5a of the exhaust box 5 through the fan connecting portion 5b as shown by the white arrows in FIG. 3 by the blowing capacity of the first blade 62b and the second blade 62c. It is possible. That is, in the hot water supply apparatus 100 of the present embodiment, the combustion gas in the exhaust box 5 is sucked to the inner peripheral side of the first surface 62aa of the impeller 62 and discharged to the outer peripheral side by the rotation of the impeller 62. .

  On the other hand, the second surface 62ab is disposed so as to be located on the back wall 61a side, and the third blade 62d on the second surface 62ab extends from the inner peripheral side to the entire outer peripheral side of the second surface 62ab. It faces the rear wall 61a without interposing other members. For this reason, the ventilation capacity of the 3rd blade | wing 62d reaches the whole space (gap 65c) between the back wall 61a and the 2nd surface 62ab. The gap 65c is connected to a gap 65b between the rotating shaft 64 and the back wall 61a. The gap 65b is connected to the gap 65a between the drive source 63 and the back wall 61a.

  With the above configuration, air can be sucked into the fan case 61 from the outside of the fan 6 through the gap 65b as shown by the black arrow in FIG. That is, in the hot water supply device 100 of the present embodiment, the air outside the fan 6 is sucked from the inner peripheral side of the second surface 62ab of the impeller 62 through the gap 65b and discharged to the outer peripheral side by the rotation of the impeller 62. Is done.

  Referring mainly to FIGS. 1 and 3, drive source 63 is provided outside fan case 61. In hot water supply apparatus 100 of the present embodiment, gap 65a between drive source 63 and rear wall 61a communicates with gap 65b.

  The rotary shaft 64 passes through the through hole 61 c of the fan case 61, thereby connecting the impeller 62 accommodated in the fan case 61 and the drive source 63 provided outside the fan case 61. As a result, the impeller 62 can rotate around the rotation shaft 64 by being given a driving force from the driving source 63.

  Referring mainly to FIG. 1, exhaust pipe 7 is disposed outside hot water supply apparatus 100 and connected to the outer peripheral side of fan case 61. For this reason, the combustion gas discharged to the outer peripheral side of the impeller 62 can be discharged to the outside of the hot water supply apparatus 100 through the exhaust pipe 7.

  Referring mainly to FIG. 1, the drain tank 8 is for storing drain generated in the secondary heat exchanger 4. The drain tank 8 and the drain outlet 4 a of the secondary heat exchanger 4 Are connected by a drain discharge pipe 9. The acidic drain stored in the drain tank 8 is, for example, temporarily stored in the internal space of the drain tank 8 and then normally discharged from the drain discharge pipe 14 to the outside of the hot water supply device 1.

  The lower portion of the drain tank 8 is connected to a drain removal pipe 15 separately from the drain discharge pipe 14. This drain drain pipe 15 (normally closed) can drain the drain tank 8 that cannot be drained from the drain drain pipe 14 by opening the drain drain pipe 15 during maintenance or the like. Designed to be able to. The interior space of the drain tank 8 may be filled with a neutralizing agent (not shown) for neutralizing acidic drain.

  Referring mainly to FIG. 1, the gas supply pipe 10 is connected to the burner 2. The water supply pipe 11 is connected to the heat transfer pipe 4b (see FIG. 2) of the secondary heat exchanger 4, and the hot water supply pipe 12 is connected to the heat transfer pipe 3a (see FIG. 2) of the primary heat exchanger 3. Further, the heat transfer tube 3 a of the primary heat exchanger 3 and the heat transfer tube 4 b of the secondary heat exchanger 4 are connected to each other by a connection pipe 13. Each of the gas supply pipe 10, the water supply pipe 11, and the hot water supply pipe 12 communicates with the outside at the upper part of the hot water supply apparatus 100, for example.

<Effect>
First, the effect of the impeller with which the hot water supply apparatus of this Embodiment is provided is demonstrated.

  The above-described impeller 62 includes a plurality of first blades 62b that extend from the inner peripheral side of the first surface 62aa of the main plate 62a to the outer peripheral side and that protrude from the first surface 62aa. Such an impeller 62 has a blowing force that discharges gas from the inner end portion 62bb side to the outer end portion 62ba side of the first blade 62b by rotating about the center line passing through the main plate 62a as the central axis. be able to.

  Further, from the radius of the virtual first circumscribed circle E connecting the outer end portions 62ba of the plurality of first blades 62b, the radius of the virtual first inscribed circle F connecting the inner end portions 62bb of the plurality of first blades 62b is changed. The reduced length is larger than the radius of the first inscribed circle F. For this reason, the ventilation force of the 1st blade | wing 62b is large, and can send out many gas rapidly toward the outer peripheral side from the inner peripheral side of a 1st surface. Such a configuration earns blowing power by the length in the extending direction of the blades, and is different from a sirocco fan that earns blowing force by the height in the protruding direction of the blades.

  The impeller 62 extends from the inner peripheral side of the first surface 62aa to the outer peripheral side and protrudes from the first surface 62aa, and is provided with a plurality of second wheels provided on the inner peripheral side of the first blade 62b. The blade 62c is further provided, and the height of the second blade 62c in the protruding direction is smaller than the height of the inner end portion 62bb of the first blade 62b in the protruding direction. Thereby, the impeller 62 can have an air blowing force superior to that of the related art. The reason for this will be described with reference to FIG.

  FIG. 12 is a schematic view schematically showing an air flow generated on the first surface 62aa side by the impeller 62. As shown in FIG. Referring to FIG. 12, airflows g1 to g4 (indicated by arrows in the figure) heading toward the inner peripheral side of the first surface 62aa of the impeller 62 are sucked to the inner peripheral side of the first surface 62aa through the opening 62ee. Further, it is discharged from the inner peripheral side to the outer peripheral side. The air flow g1 and the air flow g4 are sucked so as to be directed to a region near the inner end 62bb of the first blade 62b, and the air flow g2 and the air flow g3 are compared with the air flow g1 and the air flow g4 in the first surface 62aa. It is attracted | sucked so that it may go to the area | region (more central side of 1st surface 62aa) away from inner end part 62bb.

  Since the air flow g1 and the air flow g4 pass through a position close to the inner end portion 62bb, the blowing force of the first blade 62b is easy to reach. For this reason, it is easy to be drawn into the intake port which is a region sandwiched between the inner end portions 62bb of the adjacent first blades 62b, and is relatively easily discharged to the outer peripheral side of the first surface 62b. On the other hand, since the air flow g2 and the air flow g3 pass through a position farther from the inner end portion 62bb than the air flow g1 and the air flow g4, the blowing force of the first blade 62b is difficult to reach. For this reason, the airflow g2 and the airflow g3 tend not to be drawn into the intake port.

  In response to the above tendency, the impeller 62 extends from the inner peripheral side of the first surface 62aa to the outer peripheral side and protrudes from the first surface 62aa and is provided on the inner peripheral side of the first blade 62b. A plurality of second blades 62c are further provided. For this reason, the airflow g2 and the airflow g3 are more easily sent out from the inner peripheral side (center side) of the first surface 62aa to the outer peripheral side (circumferential side) as compared with the case where the second blade 62c is not provided.

  Here, when the height in the protruding direction of the second blade 62c is equal to or higher than the height in the protruding direction of the inner end portion 62bb of the first blade 62b, the air flow is directed toward the outer peripheral side by the blowing force of the first blade 62b. There is a risk of being located in the flow paths of g1 and g4. If the 2nd blade | wing 62c is located in the flow path of an airflow, the 2nd blade | wing 62c will become an airflow intake resistance, and will cause the fall of the ventilation force of the 1st blade | wing 62b as a result.

  However, in the impeller 62 of the present embodiment, the height of the second blade 62c in the protruding direction is smaller than the height of the inner end portion 62bb of the first blade 62b in the protruding direction. With this configuration, it is possible to suppress the second blade 62c from becoming an airflow intake resistance, and thus it is possible to suppress a decrease in the blowing power as described above. Therefore, since the impeller 62 of this embodiment can have a high capability of discharging gas from the inner peripheral side of the first surface 62aa to the outer peripheral side, it can exhibit a high blowing power.

  In particular, the height of the second blade 62c in the protruding direction is preferably less than or equal to half the height of the inner end 62bb of the first blade 62b in the protruding direction. Thereby, generation | occurrence | production of the above intake resistance can be suppressed more fully.

  Further, in the impeller 62 of the present embodiment, the virtual second circumscribed circle G connecting the outer end portions 62ca of the plurality of second vanes 62c is on the inner peripheral side of the first inscribed circle F on the first surface 62aa. Located in. For example, when the second circumscribed circle G is located on the first surface 62aa at the same position as the first inscribed circle F or on the outer peripheral side of the first inscribed circle F, the outer end portion 62ca of the second blade 62c. Is positioned on the outer peripheral side of the inner end 62bb of the first blade 62b. In such a configuration, there is a concern that the second blade 62c becomes an intake resistance against the gas flowing between the end portions 62bb of the adjacent first blades 62b. On the other hand, since the second circumscribed circle G is located on the inner peripheral side with respect to the first inscribed circle F as in the present embodiment, the occurrence of the intake resistance as described above can be suppressed. In particular, the air blowing capability of the impeller 62 is improved.

  In the impeller 62 of the present embodiment, the height in the protruding direction of the first blade 62b continuously decreases from the inner end portion 62bb of the first blade 62b toward the outer end portion 62ba. Thereby, the gas flow path sandwiched between the opposing side surfaces of the adjacent first blades 62b is the largest on the inner end 62bb side (inner peripheral side), and becomes smaller toward the outer end 62ba side. For this reason, the flow velocity of the gas flowing through the gas flow path can be effectively increased, and thus the air blowing capability of the impeller 62 is improved.

  By the way, when the height in the protruding direction of the first blade 62b continuously decreases from the inner end 62bb of the first blade 62b toward the outer end 62ba, the inner surface and the first surface on the first surface 62aa. In the vicinity of 62aa, the air blowing capability of the first blade 62b tends to be difficult. On the other hand, the impeller 62 of the present embodiment includes the second blades 62c in a region where the air blowing capacity of the first blades 62b is difficult. For this reason, when the 1st blade | wing 62b is the above shapes, especially the improvement of the ventilation capability of the impeller 62 by the ventilation capability of the 2nd blade | wing 62c becomes remarkable.

  Further, in the impeller 62 of the present embodiment, a virtual extension line H formed by extending the outer end portion 62ca of the second blade 62c in the extending direction is between the adjacent inner end portions 62bb of the first blade 62b. Pass through. Thereby, the gas discharged from the inner peripheral side of the first surface 61aa toward the outer peripheral side by the second blade 62c, that is, the gas sent out from the inner end 62cb side of the second blade 62c toward the outer end 62cb side. However, it is possible to suppress the collision with the inner end 62bb of the first blade 62b. Therefore, generation of noise due to the gas colliding with the inner end portion 62bb can be suppressed.

  Further, in the impeller 62 of the present embodiment, the first blade 62b includes a curved extension region C that extends in a curve from the inner peripheral side to the outer peripheral side of the first surface 62aa, and a curved extension region C. Is also located on the outer peripheral side, and has a linearly extending region D extending linearly from the inner peripheral side of the first surface 62aa toward the outer peripheral side. Thereby, with respect to the gas flow path sandwiched between the opposing side surfaces of the adjacent first blades 62b, the inner peripheral side (gas inflow side) is formed to bend in the rotational direction of the main plate 62a, and the outer peripheral side (gas discharge side). Then, it is formed in a straight line. Therefore, the gas can be flowed more efficiently into the gas flow path by bending in the rotation direction of the impeller 62 where the inner peripheral side of the gas flow path rotates. Further, since the shape of the gas flow path and the direction in which the centrifugal force is applied can be approximated on the outer peripheral side where the centrifugal force is easily applied to the gas flowing in the flow path, the gas toward the outer peripheral side is efficiently absorbed by the centrifugal force. Accelerated. Therefore, as a result, the air blowing capability of the impeller 62 is improved.

  In particular, in the impeller 62 of the present embodiment, a virtual extension line H that is formed by extending the outer end 62ca of the second blade 62c in the extending direction intersects with the linear extension region D. More specifically, the extension line H that passes between the two adjacent first blades 62b is the first of the two first blades 62b that is located in the rotational direction (the direction in which the curve extending region C is bent). It intersects with the straight extension region D of the blade 62b. For this reason, the gas sent out between the adjacent first blades 62b by the blowing force of the second blades 62c is the rotation direction side of the two adjacent first blades 62b (the direction in which the curve extending region C is bent). The first blade 62b is discharged to the outer peripheral side of the first surface 62aa along the side surface of the first blade 62b.

  In the gas flow path sandwiched between the opposing side surfaces of the adjacent first blades 62b, the vicinity of the side surface of the first blade 62b located on the rotation direction side is a gas flow (back flow) from the outer peripheral side of the first surface 62aa to the inner peripheral side. ) Tends to occur. This is because the gas flowing through the gas flow path has a velocity distribution. Such a back flow causes a reduction in the blowing power of the impeller 62.

  On the other hand, according to the impeller 62 of the present embodiment, as described above, the gas is sent out along the side surface of the first blade 62b located on the rotation direction side by the blowing force of the second blade 62c. . For this reason, generation | occurrence | production of the above backflows can be suppressed with the ventilation force of a 2nd blade | wing, and the ventilation force of the impeller 62 improves accordingly.

  Further, in the impeller 62 of the present embodiment, the height in the protruding direction of the second blade 62c continuously decreases from the inner end portion 62cb of the second blade 62c toward the outer end portion 62ca. Thereby, since the 2nd blade | wing 62c can send out the gas which came to the inner peripheral side of 1st surface 62aa more smoothly toward the outer peripheral side of 1st surface 62aa, the ventilation force of the impeller 62 is further improves. In particular, the height in the protruding direction of the second blade 62c continuously decreases from the inner peripheral side toward the outer peripheral side, and the height of the outer end portion 62ca of the second blade 62c is as close to zero as possible. preferable. In this case, gas can be sent out more smoothly.

  In the impeller 62 of the present embodiment, the number of second blades 62c is a divisor of the number of first blades 62b. As a result, the balance between the blowing force of the first blade 62b and the blowing force of the second blade 62c on the first surface 62aa is improved. As a result, the blowing force of the impeller 62 is uniform on the first surface 62aa. Can be.

  The impeller 62 of the present embodiment further includes a shroud 62e that covers an end portion of the first blade 62b in the protruding direction. Thereby, since the gas flow path sandwiched between the opposing side surfaces of the adjacent first blades 62b is covered with the shroud 62e, the blockage of the gas flow path is enhanced. Therefore, the impeller 62 of the present embodiment improves the air blowing capability of the first blade 62b as compared to the case without the shroud 62e.

Next, the effect of the hot water supply apparatus of this Embodiment is demonstrated.
Since the hot water supply apparatus 100 of the present embodiment is an exhaust suction combustion type hot water supply apparatus, even if the diameter of the exhaust pipe 7 is reduced, the burner 2 is used in contrast to the so-called exhaust push type hot water supply apparatus. The combustion operation due to can be stabilized. This will be described below.

  In a so-called exhaust pushing hot water supply apparatus, a fan, a burner, a primary heat exchanger, and a secondary heat exchanger are arranged in this order from the upstream side to the downstream side of the flow of combustion gas. That is, the combustion gas generated in the burner flows into the exhaust pipe outside the hot water supply device through the primary heat exchanger and the secondary heat exchanger by the fan.

  The combustion gas pushed out of the fan is subjected to flow resistance by the primary heat exchanger and the secondary heat exchanger before reaching the exhaust pipe, so the blowing pressure of the combustion gas immediately before the exhaust pipe is equal to this flow resistance. Lower. For this reason, in order to push combustion gas into the exhaust pipe having a small diameter, it is necessary to increase the blowing pressure by the fan. However, if the fan blowing pressure is increased, the internal pressure in the burner case increases. For this reason, when the supply pressure of the fuel gas supplied to the burner is low, the combustion operation becomes unstable.

  On the other hand, according to the exhaust suction combustion system of the present embodiment, the burner 2, the primary heat exchanger 3, the secondary heat exchanger 4 and the fan 6 are arranged from the upstream side to the downstream side of the flow of the combustion gas. They are arranged in this order. In this system, the upstream side of the fan 6 has a negative pressure, so there is no need to increase the blowing pressure of the fan 6. Thereby, even when the diameter of the exhaust pipe 7 becomes small, the internal pressure in the burner case can be kept low, so that the combustion operation can be stabilized even if the supply pressure of the fuel gas supplied to the burner 2 is low.

  In particular, the hot water supply apparatus 100 of the present embodiment includes an impeller 62. Since the impeller 62 is excellent in air blowing capacity as described above, the hot water supply device 100 of the present embodiment is excellent in the ability to suck the combustion gas after passing through the heat exchanger and discharge it to the hot water supply device. it can.

  Further, in the fan 6 provided in the hot water supply device 100 of the present embodiment, the fan case 61 has a back wall 61a provided with a through hole 61c, and in the fan case 61, the second surface 62ab of the impeller 62 is the back surface. It arrange | positions so that the wall 61a may be faced. Further, a gap 65 b for sucking air outside the fan case 61 into the inside of the fan case 61 is provided between the rotating shaft 64 penetrating the through hole 61 c and the back wall 61 a. Furthermore, the impeller 62 includes a plurality of third blades 62d that extend from the inner peripheral side of the second surface 62ab to the outer peripheral side and that protrude from the second surface 62ab.

  With the above configuration, the air blowing capability of the third blade 62d reaches the region between the back wall 61a and the second surface 62ab. Then, air is sucked into the fan case 61 from the outside of the fan 6 through the gap 65b as shown by the black arrow in FIG. 3 due to the air blowing capability of the third blade 62d, and this air is sucked into the inner peripheral side of the second surface 62ab. Can be sucked out and discharged to the outer peripheral side. Further, due to the air blowing ability of the third blade 62d, the clearance 65c between the back wall 61a and the impeller 62 has a resistance pressure that opposes the gas flow from the outer peripheral side to the inner peripheral side of the second surface 62ab. Arise. Therefore, according to hot water supply apparatus 100 of the present embodiment, the fan can be cooled by the inflow of air while suppressing the backflow of the combustion gas.

  In addition, the impeller 62 of the hot water supply apparatus 100 according to the present embodiment has the shroud 62e. However, when the shroud 62e is not provided, the clearance between the end of the first blade 62b in the protruding direction and the fan case 62 is increased. It is preferable to arrange them as small as possible. The first inscribed circle F of the first blade 62b is preferably designed to approximate the cross-sectional shape of the internal space 5ba of the exhaust box 5.

  In the hot water supply apparatus 100 of the present embodiment, the number of the first blades 62b and the number of the third blades 62d are the same, but are not limited thereto. However, from the viewpoint of the uniformity of the blowing capacity of the impeller 62, the number of the third blades 62d is preferably a divisor of the first blades 62b.

  Moreover, the hot water supply apparatus 100 of the present embodiment is a latent heat recovery type hot water supply apparatus capable of heating hot water by recovering latent heat, and the impeller 62 is preferably made of a resin material having acid resistance. Thereby, the impeller 62 can have resistance to acidic drain. The fan case 61, the exhaust box 5, and the exhaust pipe 7 are preferably made of a resin material having acid resistance for the same reason. The impeller 62 may be made of acid-resistant stainless steel.

  Examples of the acid-resistant resin material include fluorine such as polyphenylene nylene sulfide (PPS), syndiotactic polystyrene (SPS), polyvinyl chloride (PVC), phenol resin, epoxy resin, silicone resin, and polytetrafluoroethylene. Resin, unsaturated polyester resin, melamine resin, polycarbonate resin, methacryl styrene (MS) resin, methacryl resin, AS resin (styrene acrylonitrile copolymer), ABS resin (acrylonitrile, butadiene, styrene copolymer synthetic resin), polyethylene, polypropylene, polystyrene And polyethylene terephthalate (PET). In particular, when the impeller 62 is made of a resin material, the impeller 62 having the above-described configuration can be easily manufactured.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  100 Hot-water supply device, 1 housing, 2 burner, 2a spark plug, 3 primary heat exchanger, 3a, 4b heat transfer tube, 3b fin, 3c case, 4 secondary heat exchanger, 4a drain outlet, 4c side wall, 4d bottom Wall, 4e, 4h Opening, 4g Upper wall, 5 Exhaust box, 5a Box body, 5b Fan connection, 5ba Internal space, 6 Fan, 7 Exhaust pipe, 8 Drain tank, 9 Piping, 10 Gas supply pipe, 11 Water supply Piping, 12 Hot water piping, 13 Connection piping, 14 Drain discharging piping, 15 Draining piping, 61 Fan case, 61a Back wall, 61b Perimeter wall, 61c Through hole, 61d Internal space, 62 Impeller, 62a Main plate, 62aa 1 surface, 62ab 2nd surface, 62b 1st blade, 62c 2nd blade, 62c 3rd blade, 62ba, 62ca, 62da Outer end, 62bb, 62cb, 62db Inner end, 62e shroud, 62ee opening, 63 motor, 64 rotating shaft, 65a-65c gap, 65ca space region, A curve region, B straight region, C curve extending region, D straight extension region, E first circumscribed circle, F first inscribed circle, G second circumscribed circle, H extension line.

Claims (9)

A main plate having a first surface;
A plurality of first blades provided so as to extend from the inner peripheral side of the first surface to the outer peripheral side and protrude from the first surface;
A plurality of second blades extending from the inner peripheral side of the first surface to the outer peripheral side and protruding from the first surface, and provided on the inner peripheral side of the first blade,
The length obtained by subtracting the radius of the virtual first inscribed circle connecting the inner end portions of the plurality of first blades from the radius of the virtual first circumscribed circle connecting the outer end portions of the plurality of first blades, Larger than the radius of the first inscribed circle,
The height in the protruding direction of the second blade is smaller than the height in the protruding direction of the inner end portion of the first blade,
On the first surface, a virtual second circumscribed circle connecting outer end portions of the plurality of second blades is located on an inner peripheral side than the first inscribed circle,
Extension of the virtual that can by extending the outer end portion of the second blade in the extending direction, Ri through between the inner end portion adjacent the first blade,
The first blade is located on the outer peripheral side of the curved surface extending from the inner peripheral side to the outer peripheral side of the first surface, and on the outer peripheral side of the curved extended region. A linearly extending region extending linearly from the inner peripheral side toward the outer peripheral side,
The virtual extension line is an impeller that coincides with a virtual extension line formed by extending the linear extension region in the extension direction .   The impeller according to claim 1, wherein the second blade extends linearly in a radial direction of the second circumscribed circle.   The impeller according to claim 1 or 2, wherein a height of the second blade in the protruding direction is not more than half of a height of the inner end portion of the first blade in the protruding direction.   The height of the protruding direction of the first blade is continuously reduced from the inner end portion of the first blade toward the outer end portion of the first blade. The impeller described in 1. The height of the second blade in the projecting direction, the second blade successively smaller toward the outer end portion of the second blade from the inner end portion of any one of claims 1 to 4 The impeller described in 1. The impeller according to any one of claims 1 to 5 , wherein the number of the second blades is a divisor of the number of the first blades. The said impeller is an impeller of any one of Claims 1-6 further provided with the shroud which covers the edge part of the protrusion direction of a said 1st blade | wing. A burner that generates combustion gas;
A heat exchanger for heating hot water flowing inside by heat exchange with the combustion gas;
A fan that sucks the combustion gas after passing through the heat exchanger and discharges it to the outside of the hot water supply device,
The fan is
A fan case,
An impeller housed in the fan case;
A drive source attached to the fan case to drive the impeller;
Anda rotary shaft connecting the impeller Contact and the drive source,
The impeller is an impeller according to any one of claims 1 to 7, a water heater. The fan case has a back wall provided with a through hole,
The impeller further includes a plurality of third blades provided so as to extend from the inner peripheral side of the second surface of the main plate opposite to the first surface to the outer peripheral side and to protrude from the second surface. And the second surface is arranged to face the back wall,
Wherein between the rotary shaft and the rear wall through the through hole, the gap for sucking outside air into the interior of the fan case of the fan case is provided, according to claim 8 Hot water supply device.

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