JP2009243746A - Defrosting device of heat exchanger - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To achieve high defrosting effect by reducing a frost remaining amount as small as possible by scraping out frost to a front side by a brush without pushing the frost to a fin depth side, in defrosting by the brush, by a defrosting device using the brush. <P>SOLUTION: In this defrosting device for scraping out and removing the frost attached to surfaces of fins of a heat source side heat exchanger in a refrigerating device by a brush defrosting means comprising the brush and moved along the edge direction of the fins, the brush of the brush defrosting means is disposed so that the bristles of the brush have a prescribed scooping angle to a straight line orthogonal to the edge direction of the fins. According to this constitution, as the action for scraping out the frost to the front side of the fins acts on the frost by having the scooping angle, even when chip sections of the brush bristles are deflected to a back side in the moving direction when the frost is scraped out by the brush while moving the brush along the fin edge, the amount of frost remaining by being pushed to the fin depth side is reduced as small as possible, and defrosting effect is improved that much. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a defroster for a heat exchanger using a brush.

  Especially in cold district specification air conditioners, there is a problem of increased airflow resistance due to frost formation on the fin surface of the outdoor heat exchanger during heating operation or reduced heating capacity due to decreased heat transfer efficiency of the fins. . For this reason, it is necessary to remove frost formation on the fin surface of the outdoor heat exchanger, and as a defrosting method for that purpose, the high-temperature refrigerant discharged from the compressor is temporarily switched to the cooling operation during the heating operation. Conventionally, a defrosting operation by a so-called reverse cycle in which the frost on the fin surface is melted and removed by circulation to an outdoor heat exchanger has been common. However, when performing the defrosting operation by the reverse cycle, the heating operation is stopped during the defrosting operation, so that there is a problem that the comfort of heating in the room is impaired.

  As a technique to solve such a problem, a technique is proposed in which frost formation on the fin surface of the heat exchanger is mechanically defrosted from the outside without using refrigerant heat, thereby maintaining the comfort of heating. (See Patent Document 1).

  The defrosting device shown in this patent document 1 is a defrosting device using a brush, which moves the brush up and down along the surface of the heat exchanger, and the surface of the fin surface by the brush bristles inserted between the fins. It is configured to scrape and remove frost formation.

JP-A-4-353373

  By the way, the brush bristles are set to a hardness that causes a certain degree of bending because the surface of the fins is damaged if it is hardened more than necessary.

  However, the characteristics of the brush bristles are disadvantageous when the frost is scraped off by the bristles. That is, as shown in FIG. 4, for example, while the brush 134 is moved downward, the brush bristles 137 wipe the surface 102 a of the fin 102, and the attached frost Fa attached to the fin surface 102 a by the brush bristles 137 is removed. When scraping off, the bristles of the bristle 137 receive a contact pressure with the adhering frost Fa and bend backward in the movement direction. At this time, a part of the frost that has been scraped off is pushed into the back side of the fin 102 by the bent portion of the bristles 137, and as a result, the amount of residual frost Fb remaining between the adjacent heat transfer tubes 103 is reduced. There was a problem that the defrosting effect was diminished by increasing.

  Therefore, the present invention reduces the residual amount of frost as much as possible and reduces the residual amount of frost as much as possible by scraping the frost to the front side without pushing the frost into the fin back side by the brush at the time of defrosting with the brush. It was made for the purpose of obtaining.

  In the present invention, the following configuration is adopted as a specific means for solving such a problem.

  In the first invention of the present application, the frost adhering to the fin surface of the heat source side heat exchanger in the refrigeration apparatus is scraped off and removed by a brush defrosting means provided with a brush and moved along the edge direction of the fin. In the defrosting apparatus, the brush defrosting means is characterized in that the brush is arranged such that the brush bristles have a predetermined angle with respect to a straight line perpendicular to the edge direction of the fin. .

  The second invention of the present application is characterized in that, in the defroster for a heat exchanger according to the first invention, the crease angle of the brush can be changed and set according to the nature of the frost at the time of defrosting. Yes.

  According to a third invention of the present application, in the defroster for a heat exchanger according to the second invention, the rake angle of the brush is ensured both when the brush is moved up and down. The change setting can be made corresponding to the moving direction of the brush.

  According to a fourth invention of the present application, in the defroster for a heat exchanger according to the first, second or third invention, the vibration means for vibrating the brush using a variable mechanism for the rake angle of the brush. It is characterized by having.

  In the present invention, the following effects can be obtained.

  (A) According to the defroster for a heat exchanger according to the first invention of the present application, the brush defrosting means has a predetermined brush with respect to a straight line whose brush hairs are orthogonal to the edge direction of the fin. When the frost is scraped off by moving the brush along the fin edge, for example, the tip of the bristle is bent backward in the moving direction. However, since the above-mentioned scooping angle works to scrape the frost toward the front side of the fin, the amount of frost that is pushed into the back side of the fin is reduced as much as possible, and the defrosting effect is correspondingly reduced. Will improve.

  (B) According to the defroster for a heat exchanger according to the second invention of the present application, in addition to the effect described in the above (a), the following specific effects can be obtained. In other words, in the present invention, the crease angle of the brush can be changed and set according to the nature of the frost at the time of defrosting.

  Here, the nature of frost adhering to the fin surface of the heat exchanger is not constant, and it varies depending on the environmental conditions at the time of frost generation, such as the ambient temperature of the fin, the ambient humidity, the surface temperature of the fin, etc. It becomes a property. For example, when the outside air temperature is below the freezing point, the water adhering to the fin surface gradually freezes to become large ice, and frost is generated on this ice. Increases adhesion to the surface. On the other hand, when the outside air temperature is below freezing point, the water adhering to the fin surface freezes in a short time to become small ice, and frost is generated on this ice. The frost in is weak in adhesion to the fin surface. Moreover, the scooping angle | corner of the said brush increases the scraping action to the near side with respect to the frost scraped off, so that this is large.

  Therefore, more effective defrosting is realized by changing and setting the scooping angle of the brush according to the nature of the frost at the time of defrosting, and further improvement of the defrosting effect can be expected.

  (C) According to the defroster for a heat exchanger according to the third invention of the present application, in addition to the effect described in (b) above, the following specific effect is obtained. That is, in the present invention, the brush angle can be changed and set in accordance with the moving direction of the brush so as to be ensured both when the brush moves up and down. Without being influenced by the movement direction, effective defrosting is possible during both the upward movement and the downward movement, and a high defrosting effect can always be obtained.

  (D) According to the defroster for a heat exchanger according to the fourth invention of the present application, in addition to the effects described in (a), (b) or (c), the following specific effects are obtained. It is done. That is, in the present invention, since the brush is provided with a vibrating means that vibrates the brush by using the variable mechanism of the rake angle of the brush, the fixing force of frost formation on the fin surface is reduced by the vibration of the brush. Since the scraping action by the brush works above, the scraping action is further promoted, and further improvement of the defrosting effect can be expected.

  Hereinafter, the present invention will be specifically described based on preferred embodiments.

  FIG. 1 shows a defroster Z according to an embodiment of the present invention. This defroster Z is a cross-fin type heat formed by arranging a plurality of fins 2 that are sequentially opposed to each other at a predetermined interval and a plurality of heat transfer tubes 3 arranged in parallel in a state of passing through the fins 2. A brush defrosting means 4 for mechanically removing frost adhering to the surface of each fin 2 of the exchanger 1 is provided. In particular, the brush defrosting means 4 is provided with a fixed brush 34. It is configured.

  1-3, the brush defrosting means 4 wipes the surface of the fin 2 of the heat exchanger 1 and scrapes and removes the frost adhering to the fixed brush 34 and the fixed brush. 34 is provided with a driving means 50 that drives the heat exchanger 1 to move up and down along the ventilation surface 1a.

  The fixed brush 34 is configured by implanting a large number of brush hairs 37 on one surface of a rod-like support 35 having a length dimension substantially equal to the width of the heat exchanger 1. In addition, rotation shafts 36 are provided at both ends of the support 35. In addition, the kind, shape, etc. of the said bristle 37 are suitably selected according to the property etc. of the frost made into removal object.

  As shown in FIG. 1, the driving means 50 includes slide guides 51, 52 erected on both sides in the width direction of the heat exchanger 1. Of these slide guides 51 and 52, one slide guide 51 includes, for example, a ball screw type slide actuator (not shown). This slide actuator is driven by a reversible rotary motor 53 disposed at the upper end of the slide guide 51 so that the slider 55 can be moved up and down. A bearing 57 is attached to the slider 55. On the other hand, a slider 56 having a bearing 57 is attached to the other slide guide 52.

  The fixed brush 34 is rotatably supported at one rotating shaft 36 by a bearing 57 on the slide guide 51 side and the other rotating shaft 36 by a bearing 57 on the slide guide 52 side, and the slide brush It is rotated by a stepping motor 58 disposed on the guide 51 side (see FIG. 2). By this rotation, the angle (α, β) of the fixed brush 34 with respect to the heat exchanger 1 can be changed.

  In addition, the relative space | interval of this heat exchanger 1 and the said fixed brush 34 in the ventilation direction of the said heat exchanger 1 is a fixed brush arrange | positioned at the front edge 2a side of the said fin 2, as shown in FIG.2 and FIG.3. The tip of the 34 bristle 37 is set to a dimension that can reach at least the vicinity of the axial center of the heat transfer tube 3 of the heat exchanger 1.

  With the above configuration, the fixed brush 34 scrapes and removes frost attached to the surface 2 a of the fin 2 of the heat exchanger 1 while moving on and off by the motor 53, and corresponds to the moving direction. The stepping motor 58 changes and sets the crawl angle with respect to the heat exchanger 1.

  In this case, the relationship between the rotation direction of the fixed brush 34 and the traveling direction is set as follows. That is, in the brush defrosting means 4, the fixed brush 34 is moved down and moved up, and the fixed brush 34 scrapes and removes frost formation on the fin surface 2 c of the heat exchanger 1. In any of these cases, the required rake angle can be secured.

  Specifically, as shown in the middle part of FIG. 2, when the fixed brush 34 moves downward (in the direction of arrow D), the neutral state (the state indicated by the solid line in the lower part of FIG. 2) moves in the direction of arrow m. Rotate to secure the ugly angle (α). On the other hand, when the fixed brush 34 moves upward (in the direction of arrow U), as shown in the upper part of FIG. 2, it is rotated from the neutral state in the direction of arrow n so as to secure a scooping angle (β). It has become.

  In addition, the sizes of these scooping angles (α) and (β) are set to increase or decrease according to the environmental conditions during frost formation, as will be described later.

  Here, the defrosting effect | action using the said fixed brush 34 is demonstrated with reference to FIG.2 and FIG.3.

  As shown in FIG. 2, when the fixed brush 34 moves down, the bristle 37 of the fixed brush 34 moves down while entering between the fins, and sequentially scrapes the attached frost Fa adhering to the fin surface 2 c. . In this case, the fixed brush 34 is scraped off in a state having a scooping angle (α) as described in the middle part of FIG. 2, so that the fixed brush 34 sequentially scrapes the adhering frost Fa on the fin surface. The frost dropped is subjected to a discharge action forwardly downward (see arrow P) in the traveling direction. Therefore, the amount of residual frost Fb remaining between the adjacent heat transfer tubes 3 is reduced, and the defrosting efficiency is increased accordingly.

  On the other hand, when the fixed brush 34 moves up, the bristle 37 of the fixed brush 34 moves up while entering between the fins, and sequentially scrapes the attached frost Fa adhering to the fin surface 2c. In this case, the fixed brush 34 is scraped off in a state having a scooping angle (β) as described in the upper part of FIG. 2, so that the fixed brush 34 sequentially scrapes the adhering frost Fa on the fin surface. The frost that is dropped is subjected to a discharge action forward in the forward direction (see arrow Q). Therefore, the amount of residual frost Fb remaining between the adjacent heat transfer tubes 3 is reduced, and the defrosting efficiency is increased accordingly.

  And the magnitude | size of the said scooping angle is changed according to the ambient temperature of the fin 2, for example. That is, as described above, when the ambient temperature of the fin is lower than the predetermined temperature near the freezing point, the frost adheres strongly to the fin surface, and when the ambient temperature of the fin is higher than the predetermined temperature near the freezing point, The adhesion force of the frost to the fin surface is weak. Therefore, when the fin ambient temperature is equal to or lower than the predetermined temperature near the freezing point, the above landing angle is set to a smaller value than when the fin ambient temperature is equal to or higher than the predetermined temperature near the freezing point. The frost can be removed, and as a result, a high defrosting effect can be obtained while suppressing the driving input of the fixed brush 34.

  The ambient temperature of the above-described fin 2 affects the property of frost formation (mainly the adhesion force to the fin surface 2c). Similarly, the ambient humidity of the fin 2 determines the property of frost formation. There is a fin surface temperature, and accordingly, the above-mentioned crawl angle can be changed based on the ambient humidity of the fin 2 or the fin surface temperature. The ambient temperature, ambient humidity, or fin surface temperature of the fins 2 is also used for setting the moving speed and operating frequency of the fixed brush 34 as described below.

  In other words, the change in the crawl angle is one of the changes in the operation mode of the fixed brush 34. In addition, the operation mode of the fixed brush 34 includes the moving speed and the operation frequency of the fixed brush 34. The defrosting efficiency depends on whether the moving speed and operation frequency of the fixed brush 34 are set appropriately.

  Here, when the fin ambient temperature is equal to or lower than the predetermined temperature near the freezing point, the frost is firmly attached to the fin surface, and when the fin ambient temperature is equal to or higher than the predetermined temperature near the freezing point, the frost against the fin surface is observed. As described above, the fixing force is weak.

  When the fixed brush 34 is moved up and down to defrost the fin surface 2c, the moving speed of the fixed brush 34 corresponds to the impact force of the fixed brush 34 on frost formation, and this moving speed. The higher the is, the higher the impact force applied to frost formation.

  The operation frequency of the fixed brush 34 corresponds to the accumulation of impact force applied to frost formation, and the higher this is, the greater the cumulative impact force applied to frost formation.

  Therefore, in the brush defrosting means 4 provided with the fixed brush 34, for example, when the fin ambient temperature is equal to or lower than a predetermined temperature near the freezing point, the fixing force of the frost to the fin surface 2c is weak. Even if the moving speed of the fixed brush 34 is set low or the operation frequency of the fixed brush 34 is set low, a high defrosting effect can be obtained.

  On the other hand, when the fin ambient temperature is equal to or higher than a predetermined temperature near the freezing point, the frosting is strongly fixed to the fin surface 2c, but the moving speed of the fixed brush 34 is set high or the operation of the fixed brush 34 is performed. By setting the frequency high, a high defrosting effect can be obtained.

  By obtaining such a high defrosting effect, the heat transfer efficiency in the fins 2 is restored, and the ventilation resistance between the fins is reduced. Due to these synergistic effects, the heat exchanger 1 has a high heat exchange. It will be.

  In addition, the change of the scooping angle, the moving speed of the fixed brush 34, and the operation frequency of the fixed brush 34 are arbitrary depending on the conditions on the frosting side, such as adopting any of these alone or combining them. Can be selected.

  Incidentally, as described above, the fixed brush 34 is appropriately rotated by the stepping motor 58. Therefore, by rotating the fixed brush 34 by the stepping motor 58 in small increments, it is possible to apply vibration to the fixed brush 34 while ensuring a predetermined angle, and the vibration of the fixed brush 34 is reduced. By being transmitted to frost formation via the brush bristles 37, the fixing force of the frost formation on the fin surface 2c is reduced. Thus, the scraping action is further promoted by scraping off the frost by the brush bristles 37 while reducing the fixing force with respect to the fin surface 2c, so that the brush defrosting means 4 can be defrosted at night. The effect will be further improved. In this embodiment, the stepping motor 58 corresponds to “vibration means” in the claims.

  As described above, in the defrosting device Z according to this embodiment, the provision of the groin angle to the fixed brush 34, the change setting of the groin angle, and the vibration action of the fixed brush 34 work synergistically. Thus, an extremely high defrosting effect is realized.

It is a whole perspective view of the defroster of the heat exchanger which concerns on embodiment of this invention. It is a defrosting state explanatory drawing of the defrosting apparatus shown in FIG. It is III-III sectional drawing of FIG. It is a defrosting state explanatory drawing of the conventional defrosting apparatus.

Explanation of symbols

1 .. Heat exchanger 2 .. Fin 3 .. Heat transfer tube 4 .. Brush defrosting means 34 .. Fixed brush 35 .. Support body 36 .. Rotating shaft 37 .. Brush hair 50 .. Driving means 51. Slide guide 52 .. Slide guide 53 .. Lifting motor 55 .. Slider 56 .. Slider 57 .. Bearing 58 .. Stepping motor Fa .. Adhering frost Fb.

Claims (4)

In the defrosting apparatus, the frost attached to the fin surface of the heat source side heat exchanger in the refrigeration apparatus is scraped and removed by a brush defrosting means that includes a brush and moves along the edge direction of the fin.
The defroster for a heat exchanger, wherein the brush defrosting means is arranged such that the brush bristles have a predetermined angle with respect to a straight line perpendicular to the edge direction of the fin. . In claim 1,
The scooping angle of the brush can be changed and set according to the nature of the frost at the time of defrosting. In claim 2,
The heat exchanging feature is characterized in that the scooping angle of the brush can be changed and set in accordance with the moving direction of the brush so as to be ensured both when the brush moves up and down. Defrosting device. In claim 1, 2 or 3,
A defroster for a heat exchanger, comprising a vibrating means that vibrates the brush by using a mechanism for changing the scooping angle of the brush.

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