JP2009243748A - Defrosting device of heat exchanger - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a defrosting device achieving high defrosting effect by promoting discharge of frost scraped off by a rotary brush to the outside of fins. <P>SOLUTION: In this defrosting device comprising a brush defrosting means 4 for scraping off and removing the frost Fa formed on fin surfaces 2c by vertically moving the rotary brush 41 along a ventilation face 1a of a heat exchanger 1, the rotary brush 41 is constituted to be rotated to a front side from a back side in the traveling direction at a heat exchanger 1 side. According to this constitution, as the rotary brush 41 is constantly rotated from the back side in the traveling direction to the front side at the heat exchanger 1 side in both of its upward movement and downward movement, the frost scraped off from the fin surfaces 2c by the rotary brush 41 receives the action to be scraped out to the outside of the fins from between the fins by the rotating force of the rotary brush 41. As a result, the amount of frost Fb remaining on the fin surfaces 2c is reduced as small as possible, and high defrosting effect is obtained, thus a heat exchanging capacity of the heat exchanger 1 is kept at a high level. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

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

Japanese Utility Model Publication No. 6-59769

  The defrosting device shown in this Patent Document 1 is a defrosting device using a rotating brush, which moves the rotating brush in the vertical direction along the ventilation surface of the heat exchanger while rotating the rotating brush, and between the fins. It is comprised so that the frost formation of the fin surface may be scraped off and removed with the brass hair of the inserted rotating brush.

  However, in the defrosting device described in Patent Document 1, a rotating brush arranged in a horizontal state on the upstream side of the ventilation surface of the heat exchanger is set up vertically on both sides of the heat exchanger. As shown in FIG. 7, the rotating direction of the rotating brush 110 is the moving direction (that is, the moving direction (that is, the rack and pinion mechanism comprising a rack and a pinion attached to the rotating brush). The ascending direction and the descending direction) are always constant, and on the front edge 102a side of the fin 102 of the heat exchanger 101, the rotating brush 110 rotates from the front side to the rear side in the traveling direction. Yes.

  When the rotating brush 110 rotates in this way, when the adhering frost Fa on the fin surface 2c is scraped off by the bristles 111 of the rotating brush 110, the rotating brush 110 is rotated as indicated by an arrow V0 in FIG. Along with this, the bristle 111 causes a force to push the adhering frost Fa toward the back side of the fin (the rear edge 102b side). A part of the frost scraped off from the adhering frost Fa by this pushing action is pushed and hardened to the heat transfer tube 103 side without being discharged from between the fins to the outside, and a relatively large amount of residual frost Fb remains here. It will be. As the residual frost Fb increases in this way, the defrosting effect on the fin surface 2c is reduced, the heat transfer efficiency of the fin 102 is not recovered, and the heat exchange capacity of the heat exchanger 101 cannot be sufficiently obtained. It will be.

  Then, this invention is made | formed for the purpose of providing the defrosting apparatus which acquired the high defrosting effect by promoting discharge | emission of the frost scraped off with the rotating brush out of the fin.

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

  In 1st invention of this application, in the defroster of the heat exchanger which removes the frost adhering to the fin surface of the heat source side heat exchanger in a refrigerating apparatus, the rotary brush driven to rotate is made into the ventilation surface of the said heat exchanger. And a brush defrosting means that scrapes and removes frost formation on the fin surface by moving up and down along, and is configured to rotate the rotating brush from the rear side in the traveling direction to the front side on the heat exchanger side. It is characterized by that.

  In the second invention of the present application, in the defrosting device for the heat exchanger according to the first invention, the defrosting frost means for melting and removing frost formation on the fin surface by the heat of the high-temperature refrigerant discharged from the compressor. And the defrosting frosting means is operated when only the brush defrosting means has insufficient defrosting capability.

  In a third invention of the present application, in the defrosting device for a heat exchanger according to the second invention, the lack of the defrosting capacity is caused by an increase in driving input of a fan attached to the heat exchanger or the heat. The determination is based on a decrease in the heat exchange capacity of the exchanger.

  According to a fourth invention of the present application, in the heat exchanger defrosting device according to the second or third invention, the defrosting frost means is used, and the high-temperature refrigerant from the compressor in the heating operation cycle is used as the heat exchanger side. It is characterized in that it is configured to supply to.

  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 rotary brush that is rotationally driven is moved up and down along the ventilation surface of the heat exchanger to scrape the frost on the fin surface. The rotary brush has a defrosting means for dropping and removing, and the rotary brush is configured to rotate from the rear side in the traveling direction to the front side on the heat exchanger side. The frost that is scraped off from the fin surface by the rotating brush by the rotational force of the rotating brush is always rotated by the rotating brush because the rotating direction always rotates from the rear side to the front side on the heat exchanger side. As a result, the amount of frost remaining on the fin surface is reduced as much as possible, a high defrosting effect is obtained, and the heat transfer efficiency of the fin is restored. And then heat Heat exchange capacity of the exchanger is to be maintained at high levels.

  (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. That is, according to the present invention, the defrosting frost means for melting and removing the frost formation on the fin surface by the heat of the high-temperature refrigerant discharged from the compressor is provided. Driving is performed when the defrosting capacity is insufficient.

  Here, in particular, when the outside air temperature is below the freezing point, the moisture adhering to the fin surface freezes and frost is generated thereon, so that the frost under such generation conditions has a fixing force to the fin surface. Strongly, it may happen that the defrosting means cannot perform sufficient defrosting only by the scraping action of the rotating brush. That is, the defrosting capability of the brush defrosting means may be insufficient with respect to the required defrosting capability from the heat exchanger side.

  In this case, in addition to the defrosting by the brush defrosting means, the fixing force to the fin surface of the frost is reduced by operating the defrosting frosting means to melt the frost, and the brush defrosting means scrapes off. The frost can be effectively removed by the action, the residual frost on the fin surface can be reduced as much as possible, and a high defrosting effect can be obtained.

  Further, the defrosting frost means is operated only when the defrosting capacity of the brush defrosting means is insufficient with respect to the required defrosting capacity, so that the heat exchange capacity due to a decrease in the refrigerant temperature in the cycle. As a result, the defrosting effect and the maintenance of the heat exchange capacity are compatible.

  (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 lack of defrosting capacity is determined based on an increase in driving input of a fan attached to the heat exchanger or a decrease in heat exchange capacity of the heat exchanger. The frost formation amount on the fin surface (including the residual frost amount), that is, the lack of defrosting capability is accurately judged, and the defrosting frosting means can be operated only when necessary. A high defrosting effect can be obtained while keeping the running cost associated with.

  (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 (b) or (c), the following specific effects can be obtained. That is, in the present invention, since the defrosting frost means supplies the high-temperature refrigerant from the compressor to the heat exchanger side in the heating operation cycle, the defrosting frost means continues with heating operation being continued. A defrosting effect can be obtained, thereby realizing non-stop heating, and it is possible to achieve both the comfort of heating and the maintenance of the heating capacity by defrosting.

  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. The brush defrosting means 4 that mechanically removes frost attached to the surface of each fin 2 of the exchanger 1 and the frost attached to the surface of each fin 2 are melted by the heat of the refrigerant circulating in the cycle. It comprises a defrosting frost means 5 to be removed.

  Of the brush defrosting means 4 and the defrosting frosting means 5, the brush defrosting means 4 is continuously operated during defrosting using this as the main defrosting means, and the defrosting frosting means 5 is the secondary defrosting means. As the frosting means, only the brush defrosting means 4 is operated supplementarily only when the defrosting ability is insufficient.

  FIG. 5 shows a refrigerant circuit of the air conditioner. In this air conditioner, a compressor 12, an indoor heat exchanger 13, an expansion valve 14, and an outdoor heat exchanger 11 are connected by a refrigerant pipe 21 to form a cycle. As the outdoor heat exchanger 11, The heat exchanger 1 is applied. Accordingly, the outdoor heat exchanger 11 is provided with the brush defrosting means 4 described below, and the outdoor heat exchanger 11 side from the three-way valve 15 provided on the discharge side of the compressor 12 via the bypass line 22. The three-way valve 15 and the bypass line 22 constitute the above-mentioned melt-releasing frost means 5.

  In FIG. 5, reference numeral 17 denotes a fan for an outdoor unit that is rotationally driven by a fan motor 18, 16 is a controller that performs operation control of the brush defrosting means 4 and start / stop control of the defrosting frost means 5, 19 Is a temperature sensor provided in the heat exchanger 1.

  Hereinafter, the configuration, control mode, and the like of the brush defrosting unit 4 and the defrosting frosting unit 5 will be specifically described.

A: Brush defrosting means 4
1 to 4, the brush defrosting means 4 wipes the surface of the fin 2 of the heat exchanger 1 and scrapes and removes the frost adhering thereto, and the rotation brush 41 A drive means 50 for moving the brush 41 up and down is provided.

  The rotating brush 41 is constructed by implanting a large number of brush hairs 43 around the rotating shaft 42, and the type, shape, etc. of the brush hairs 43 are the properties of the frost to be removed. It is selected as appropriate.

  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 rotating brush 41 is rotatably supported on one end side of the rotating shaft 42 by a bearing 57 on the slide guide 51 side and on the other end side by a bearing 57 on the slide guide 52 side, and on the slide guide 51 side. Is driven to rotate by a reversible rotary motor 54 disposed in Here, as a means for rotating the rotating brush 41, in addition to using the reversible rotating motor 54 as described above, for example, as shown in FIG. 6, it is attached to the rack 25 and the rotating shaft 42 of the rotating brush 41. An idler gear 27 may be interposed in a rack and pinion mechanism including the pinion 26 formed.

  The relative distance between the heat exchanger 1 and the rotary brush 41 in the ventilation direction of the heat exchanger 1 is a rotary brush arranged on the front edge 2a side of the fin 2 as shown in FIGS. The tip of the 41 bristles 43 may be set so as to reach the vicinity of the axial center of the heat transfer tube 3 of the heat exchanger 1, or the bristles 43 may reach the back side of the heat exchanger 1. It may be set to.

  With the above configuration, the rotating brush 41 is rotationally driven by the motor 54 and wipes 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.

  In this case, the relationship between the rotation direction of the rotary brush 41 and the traveling direction is set as follows. That is, in the present invention, the rotating brush 41 moves down along the heat exchanger 1 as shown in FIG. 2 with the intention of scraping the frost scraped off by the rotating brush 41 out of the fins. In addition, as shown in FIG. 3, when the rotary brush 41 moves upward along the heat exchanger 1, the rotary brush 41 is moved from the rear side to the front side in the traveling direction on the heat exchanger 1 side. The rotation direction is set so as to rotate toward. Therefore, the rotation direction of the rotating brush 41 is opposite between the upward movement and the downward movement.

  Here, the defrosting action by the rotating brush 41 will be described with reference to FIGS.

  As shown in FIG. 2, when the rotary brush 41 moves downward, the bristles 43 of the rotary brush 41 rotate in a state of entering between the fins, and sequentially scrape the attached frost Fa adhering to the fin surface 2c. However, in this case, as indicated by the arrow R, the rotating brush 41 rotates from the rear side to the front side in the traveling direction (that is, the descending direction) on the heat exchanger 1 side. On the exit side of the fin 2 from the fin 2, the frost that is sequentially scraped off from the attached frost Fa on the surface of the fin by the rotating brush 41 undergoes a scraping action in the direction indicated by the arrow V <b> 1. It will be discharged smoothly.

  Further, as shown in FIG. 3, even when the rotary brush 41 moves upward, as shown by the arrow L, the rotary brush 41 is behind the heat exchanger 1 side in the traveling direction (that is, the upward direction). Since the rotating brush 41 rotates toward the front side, on the exit side of the rotating brush 41 from the fin 2, the frost that is sequentially scraped from the attached frost Fa on the fin surface by the rotating brush 41 is indicated by an arrow V2. As a result of the scraping action in the direction shown, the fins 2 are smoothly discharged outward.

  Therefore, the amount of residual frost Fb remaining on the fin surface 2c after the defrosting is the same as that of the conventional structure shown in FIG. Compared with the case where the fins are pushed into the back side of the fin and hardened due to the scraping action, the remarkably high defrosting effect is obtained.

  As a result, 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.

B: Melting-freezing frost means 5 By the way, in the outdoor heat exchanger, in particular, when the outside air temperature is below the freezing point, water adhering to the fin surface 2c is frozen, and frost is generated thereon. The frost under such generation conditions has a strong adhering force to the fin surface 2c, and it may happen that the frost cannot be sufficiently defrosted only by the scraping action by the rotating brush 41 in the brush defrosting means 4. That is, the defrosting capability of the brush defrosting means 4 may be insufficient with respect to the required defrosting capability from the heat exchanger 1 side.

  In such a case, if the adhesion force of the frost to the fin surface 2c is weakened, the frost can be easily scraped off by the rotating brush 41 of the brush defrosting means 4. In this embodiment, the defrosting frosting means 5 is provided as means for weakening the fixing force of the frosting on the fin surface 2c.

  As shown in FIG. 5, the defrosting frost means 5 is supplied from a three-way valve 15 provided on the discharge side of the compressor 12 to the heat exchanger 1 applied as the outdoor heat exchanger 11 during heating operation. As described above, the high-temperature refrigerant is supplied through the bypass line 22 and the frost adhering to the fin surface 2c is melted by the refrigerant heat.

  Here, since the defrosting frost means 5 uses the heat of the refrigerant in the cycle, for example, although there is no heat loss as in the case of performing the defrosting operation in the reverse cycle, the heat exchange capacity is lowered due to the lowering of the refrigerant temperature. Therefore, it is necessary to reduce the operation time as much as possible and to operate only when the operation is necessary (when the defrosting capability is insufficient only with the brush defrosting means 4). Is preferred.

  Therefore, in this embodiment, whether the defrosting capability of the brush defrosting means 4 is insufficient is determined by increasing the drive input of the fan 17 attached to the heat exchanger 1 or the heat exchange capability of the heat exchanger 1. It is done based on the decrease of The former is based on the fact that when the amount of frost formation on the fin surface 2c increases, the ventilation resistance between the fins increases and the drive input of the fan motor 18 increases accordingly. The latter is based on the fact that when the amount of frost formation on the fin surface 2c increases, the heat transfer efficiency of the fin 2 decreases and the heat exchange capacity of the heat exchanger 1 decreases.

  Specifically, as shown in FIG. 5, the condensation temperature detected by the temperature sensor 19 attached to the heat exchanger 1 is input to the controller 16, and if the condensation temperature is equal to or higher than a certain value, the defrosting capacity is insufficient. When the state is determined, or when the drive input of the fan motor 18 is taken into the controller 16 and the drive input is greater than a predetermined value, it is determined that the defrosting capacity is insufficient.

  If it is determined that the defrosting capability is insufficient, the defrosting frost means 5 is additionally operated in addition to the operation supply of the brush defrosting means 4, and the defrosting frost means 5 forms the frost. As a result, it is possible to obtain a high defrosting effect by weakening the adhesion force to the fin surface 2c and promoting the scraping action by the rotating brush 41 of the brush defrosting means 4.

It is a whole perspective view of the defroster of the heat exchanger which concerns on embodiment of this invention. It is defrost state explanatory drawing in the descent | fall process of the defrosting apparatus shown in FIG. It is a defrost state explanatory drawing in the raise process of the defroster shown in FIG. It is IV-IV sectional drawing of FIG. 1 is a refrigeration circuit diagram to which a defroster according to an embodiment of the present invention is applied. It is explanatory drawing of the other structural example of the rotation mechanism of a rotating brush. It is a defrost state explanatory drawing in the defroster of the conventional heat exchanger.

Explanation of symbols

1 .. Heat exchanger 2 .. Fin 3 .. Heat transfer tube 4 .. Brush defrosting means 5 .. Defrosting frost means 11 .. Outdoor heat exchanger 12 .. Compressor 13 .. Indoor heat exchanger 14・ Expansion valve 15 ・ ・ Three-way valve 16 ・ ・ Controller 17 ・ ・ Fan 18 ・ ・ Fan motor 19 ・ ・ Temperature sensor 21 ・ ・ Refrigerant line 22 ・ ・ Bypass line 41 ・ ・ Rotating brush 42 ・ ・ Rotating shaft 43 ・· Brush hair 50 · · Driving means 51 · · Slide guide 52 · · Slide guide 53 · · Lifting motor 54 · · Rotating motor 55 · · Slider 56 · · Slider 57 · · Bearing Fa · · Frozen frost Fb · · Residual frost

Claims (4)

A defroster for a heat exchanger that removes frost adhering to the fin surface of the heat source side heat exchanger in the refrigeration apparatus,
While having a brush defrosting means for raising and lowering the rotating brush to be rotated along the ventilation surface of the heat exchanger and scraping and removing frost formation on the fin surface,
The defroster for a heat exchanger, wherein the rotating brush is configured to rotate from the rear side in the traveling direction to the front side on the heat exchanger side. In claim 1,
While equipped with a defrosting frost means for melting and removing the frost on the fin surface by the heat of the high-temperature refrigerant discharged from the compressor,
The defrosting device for a heat exchanger, wherein the defrosting frost means is operated when the defrosting capability is insufficient with only the brush defrosting means. In claim 2,
The lack of defrosting capability is determined based on an increase in driving input of a fan attached to the heat exchanger or a decrease in heat exchange capability of the heat exchanger. apparatus. In claim 2 or 3,
The defrosting device for a heat exchanger, wherein the defrosting frost means is configured to supply high-temperature refrigerant from a compressor to the heat exchanger side in a heating operation cycle.

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