EP2767767A1

EP2767767A1 - Outdoor unit for air conditioning device

Info

Publication number: EP2767767A1
Application number: EP12835730.8A
Authority: EP
Inventors: Hiroshi YOU; Tadafumi Nishimura; Mamoru Okumoto; Yutaka Shibata
Original assignee: Daikin Industries Ltd
Current assignee: Daikin Industries Ltd
Priority date: 2011-09-30
Filing date: 2012-09-27
Publication date: 2014-08-20
Anticipated expiration: 2032-09-27
Also published as: CN103857964A; EP2767767A4; US20140263765A1; ES2747474T3; WO2013046689A1; JP2013083431A; JP5310917B2; CN103857964B; EP2767767B1

Abstract

A spray nozzle (21) of an outdoor unit (11) is provided with: an air guide portion (30) through which air flows; a water guide portion (40) through which water flows and which causes the air flowing through the air guide portion (30) to flow into water to form water containing a large number of bubbles; and a spray portion (51) that is located downstream of the water guide portion (40) in a direction of water flow and sprays, to the outside, the water containing a large number of bubbles which is formed in the water guide portion (40).

Description

Technical Field

The present invention relates to an outdoor unit for an air conditioning device.

Background Art

There has conventionally been known an outdoor unit for an air conditioning device that has a spray device for auxiliary cooling a heat exchanger by spraying water from a spray nozzle to the heat exchanger. Cooling the heat exchanger by means of the sprayed water in this outdoor unit can effectively reduce the power (power consumption) required by the air conditioning device. In this type of air conditioning device, unfortunately, droplets of the water adhering to the surface of the heat exchanger often leads to corrosion of the heat exchanger.
Patent Document 1 discloses an outdoor unit provided with a fine mist generating nozzle. This fine mist generating nozzle is located on the upstream side of a heat exchanger and away therefrom, and generates fine mist having a particle diameter of 10 µm or less by injecting air and water simultaneously. Patent Document 1 describes that the fine mist injected from the fine mist generating nozzle evaporates prior to reaching the heat exchanger, preventing adherence of the droplets to the heat exchanger.
Patent Document 1: Japanese Patent Application Publication No. 2008-128500
However, a spray nozzle that injects air and water simultaneously from its spray hole is a conventional two-fluid nozzle that creates fine droplets by adding shear force to the water at the pressure of the air. For this reason, the spray nozzle requires large power for the purpose of injecting air at high speeds. In such a case, the power reduction effect of the entire air conditioning device might not be accomplished adequately.

Summary of the Invention

An object of the present invention is to provide an outdoor unit that is capable of reducing the power of the entire air conditioning device while preventing corrosion of a heat exchanger.
An outdoor unit for an air conditioning device according to the present invention has a heat exchanger and a spray nozzle for spraying water to air flowing toward the heat exchanger. The spray nozzle is provided with an air guide portion through which the air flows, a water guide portion through which water flows and in which the air flowing through the air guide portion flows into the water to form water which contains a large number of bubbles, and a spray portion which is located downstream of the water guide portion in a direction of water flow and which sprays to the outside the water formed in the water guide portion and containing a large number of bubbles.

Brief Description of the Drawings

[Fig. 1] Fig. 1 is a schematic diagram showing an outdoor unit according to a first embodiment of the present invention.
[Fig. 2] Fig. 2 is a perspective view showing how a heat exchanger and spray nozzles are arranged in the outdoor unit.
[Fig. 3] Fig. 3 is a cross-sectional diagram of one of the spray nozzles.
[Fig. 4] Fig. 4 is a cross-sectional diagram of a spray nozzle of an outdoor unit according to a second embodiment of the present invention.
[Fig. 5] Fig. 5 is a cross-sectional diagram of a spray nozzle of an outdoor unit according to a third embodiment of the present invention.
[Fig. 6] Fig. 6A is a perspective view showing an air guide pipe of the spray nozzle according to the third embodiment, Fig. 6B a perspective view showing modification 1 of the air guide pipe, and Fig. 6C a perspective view showing modification 2 of the air guide pipe.
[Fig. 7] Fig. 7 is a schematic diagram showing an outdoor unit according to another embodiment of the present invention.
[Fig. 8] Fig. 8 is a perspective view showing how a heat exchanger and spray nozzles are arranged in the outdoor unit.
[Fig. 9] Fig. 9 is a schematic diagram for explaining an example of the arrangement of spray nozzles in relation to the heat exchanger.
[Fig. 10] Fig. 10 is a schematic diagram showing an outdoor unit according to yet another embodiment of the present invention.
[Fig. 11] Fig. 11 is a diagram for explaining the relationship between a distribution of wind velocity of air flowing toward a heat exchanger in the outdoor unit and the distance between a spray nozzle and each of various sections of the heat exchanger.
[Fig. 12] Fig. 12A is a schematic diagram for explaining modification 1 of a charging mechanism, and Fig. 12B an enlarged perspective view for explaining a spray nozzle and an induction electrode.
[Fig. 13] Fig. 13 is a schematic diagram for explaining modification 2 of the charging mechanism.

Best Mode for Carrying Out the Invention

An outdoor unit according to a first embodiment of the present invention is now described hereinafter with reference to the drawings.
An outdoor unit 11 according to the first embodiment is used in an air conditioning device. The air conditioning device has the outdoor unit 11 shown in Fig. 1, an indoor unit which is not shown, and a refrigerant pipe section, not shown, which connects the outdoor unit 11 and the indoor unit to each other. As shown in Fig. 1, the outdoor unit 11 has a case 12, a heat exchanger 13, a fan 14, a compressor 15, a spray device 20, an outside air temperature sensor 18, a controller 16 and the like. The heat exchanger 13, the fan 14, the compressor 15, and the controller 16 are disposed inside the case 12. The fan 14, the compressor 15, and the spray device 20 are controlled by the controller 16. The compressor 15 and the heat exchanger 13 are provided in a refrigerant circuit of the air conditioning device.
Examples of the heat exchanger 13 include, but are not limited to, a cross fin coil-type heat exchanger. The cross fin coil-type heat exchanger has heat-transfer pipes and a large number of plate fins through which the heat-transfer pipes penetrate. A refrigerant flows inside the heat-transfer pipes, and outside air flows between the plate fins. As a result, heat exchange between the refrigerant and the outside air takes place.
As shown in Fig. 2, the heat exchanger 13 extends upward from a bottom panel of the case 12 and formed in substantially a U-shape as planarly viewed. In other words, the heat exchanger 13 is provided upright with respect to an installation surface (horizontal surface) of the outdoor unit 11. Of the four side panels of the case 12, the three side panels facing the heat exchanger 13 are each provided with an air inlet, not shown, which draws in outside air into the case 12. The top panel of the case 12 is provided with an air outlet 17 for blowing the air of the case 12 to the outside.
A centrifugal fan, an axial fan, a diagonal flow fan or the like can be used as the fan 14. The fan 14 has an impeller 14a and a motor, not shown, which rotates the impeller 14a. The fan 14 is disposed inward of the heat exchanger 13 in a horizontal direction in the outdoor unit 11 and above the heat exchanger 13. More specifically, the fan 14 is provided in an upper part of the case 12, as shown in Fig. 1, and is disposed immediately below the air outlet 17 shown in Fig. 2. The fan 14 emits upward, from the outdoor unit 11 (the case 12) to the outside, air that flew into the outdoor unit 11 (the case 12) and was subjected to heat exchange by the heat exchanger 13. In other words, the fan 14 is located downstream of the heat exchanger 13 in a direction of airflow.
When the air conditioning device is running, the compressor 15 receives power, which consequently allows the refrigerant to circulate in the refrigerant circuit between the outdoor unit 11 and the indoor unit, and at the same time power is applied to the motor of the fan 14 to rotate the impeller 14a, thereby drawing in outside air through the air inlet into the case 12. Subsequent to heat exchange between the outside air drawn into the case 12 and the refrigerant in the heat exchanger 13 as described above, the outside air is blown to the outside of the case 12 via the air outlet 17. More specifically, during, for example, a cooling operation of the air conditioning device, heat exchange takes place between the outside air drawn into the case 12 and the high-temperature, high-pressure refrigerant via the heat-transfer pipe of the heat exchanger 13 functioning as a condenser, the refrigerant flowing through the heat-transfer pipe. In other words, the outside air cools the heat-transfer pipe of the heat exchanger 13 and the refrigerant. As a result, the refrigerant flowing through the heat-transfer pipe is cooled and condensed.
The spray device 20 is described next. The spray device 20 is capable of cooling the outside air flowing toward the heat exchanger 13 during the cooling operation. In other words, the spray device 20 lowers the temperature of the outside air flowing toward the heat exchanger 13. In this manner, the effect of cooling the heat-transfer pipe of the heat exchanger 13 and the refrigerant can be enhanced. The spray device 20 can therefore improve the cooling performance of the air conditioning device by auxiliary cooling the heat exchanger 13 and the refrigerant.
As shown in Figs. 1 to 3, the spray device 20 has a plurality of spray nozzles 21, a water supply mechanism 60, an air supply mechanism 70, and a charging mechanism 80 as a charger.
The plurality of spray nozzles 21 are each supported by a supporting member, not shown, which is provided separately on each side panel of the case 12 or in the case 12. Each of the spray nozzles 21 is located upstream of the heat exchanger 13 in a direction of an air stream which is formed as the impeller 14a of the fan 14 rotates. In the present embodiment, each of the spray nozzles 21 is disposed on the outside of and above the heat exchanger 13 in the outdoor unit 11, in such a manner as to spray droplets (water drops, in the present embodiment) downward. In other words, each of the spray nozzles 21 is disposed such that an axial direction thereof is substantially perpendicular to the direction of outside air (the air) flowing substantially horizontally toward the heat exchanger 13. Water drops that are sprayed from each of the spray nozzles 21 are spread radially downward and moved toward the heat exchanger 13 by the flow of air. All or most of the water drops vaporize prior to reaching the heat exchanger 13.
Because each of the spray nozzles 21 sprays water drops downward, even those large water drops that do not vaporize quickly are dropped downward (onto the installation surface of the outdoor unit 11 or the like) across the flow of outside air by the force of the downward spray motion and gravity added to these water drops. This can prevent adherence of the large water drops to the heat exchanger 13, whereby the heat exchanger 13 is prevented from being wet.
As shown in Fig. 2, the plurality of spray nozzles 21 are disposed horizontally at intervals on three side panels 12a, 12b, 12c facing the heat exchanger 13 so as to provide the cooling effect of the spray device 20 to substantially the entire heat exchanger 13. Specifically, the plurality of nozzles 21 are disposed horizontally at an interval of, for example, several tens of centimeters based on a range in which the water drops from each spray nozzle 21 are spread, i.e., a range in which the outside air flowing toward the heat exchanger 13 is cooled by each spray nozzle 21.
The present embodiment illustrates a case in which the range in which the water drops from each spray nozzle 21 are spread (the horizontal range) is, for example, approximately 50 cm, the width of the side panel 12a approximately, for example, 100 cm, and the width of the side panels 12b, 12c approximately 30 cm. Two spray nozzles 21 are disposed horizontally at intervals on the side panel 12a, and one spray nozzle 21 on each of the side panels 12b and 12c. Note that these spray nozzles 21 are disposed at the same height.
The water supply mechanism 60 includes a liquid feed piping section 61 and a liquid feed pump 62. The liquid feed piping section 61 connects a water source, not shown, such as a water line, and each spray nozzle 21 to each other. The liquid feed piping section 61 includes a conductive piping section 61 a (a metal piping section 61a, in the present embodiment) that is located on the upstream side of flow of water, and an insulating piping section 61b (a resin piping section 61b, in the present embodiment) that is located on the downstream of the same. The liquid feed pump 62 feeds the water to each of the spray nozzles 21 via the liquid feed piping section 61.
The air supply mechanism 70 includes an air feed pump 72 such as a compressor, and an air feed piping section 71. The air feed piping section 71 connects the air feed pump 72 and each of the spray nozzles 21 to each other.
The charging mechanism 80 includes a charging power supply (a high-voltage power supply) 81, wiring sections 82, 83, and an output regulator 84. The wiring section 82 connects a positive electrode of the charging power supply 81 to a leading end portion of each spray nozzle 21. The wiring section 83 connects a negative electrode of the charging power supply 81 to the conductive piping section 61a of the liquid feed piping section 61. This configuration positively charges the water (water drops) sprayed from the spray nozzle 21. The positive electrode of the charging power supply 81 is grounded in such a manner that the spray nozzle 21 becomes a ground potential. The resin piping section 61b is made of electric insulating synthetic resin and is located downstream of the connection between the wiring section 83 and the liquid feed piping section 61. The output regulator 84 regulates an output of the charging power supply 81.
Although Fig. 1 shows a state in which the water supply mechanism 60, the air supply mechanism 70, and the charging mechanism 80 are connected a single spray nozzle 21, and omits illustration of the other spray nozzles 21, the water supply mechanism 60, the air supply mechanism 70, and the charging mechanism 80 are connected to the other spray nozzles 21 in the same manner as the one shown in Fig. 1. More specifically, for example, the liquid feed piping section 61 of the water supply mechanism 60 branches off in the middle, to be connected to the plurality of spray nozzles 21, and the air feed piping section 71 of the air supply mechanism 70 also branches off in the middle, to be connected to the plurality of spray nozzles 21. For instance, the plurality of spray nozzles 21 are connected in parallel to one another with respect to the charging power supply 81 of the charging mechanism 80.
The outside air temperature sensor 18 is capable of detecting the outside air temperature. For instance, when the outside air temperature sensor 18 detects that the outside air temperature reaches a predetermined temperature or higher, the controller 16 determines that the load of the cooling operation exceeds a predetermined level set beforehand, and then controls the liquid feed pump 62 and the air feed pump 72 to start spraying water from the plurality of spray nozzles 21. For example, during a predetermined time period, the controller 16 controls the liquid feed pump 62 and the air feed pump 72 so that the water is sprayed continuously or intermittently from each of the spray nozzles 21. The controller 16 also controls the output regulator 84 of the charging mechanism 80 and applies a voltage to each of the spray nozzles 21 by means of the charging power supply 81 in order to electrically charge water drops sprayed from each of the spray nozzles 21.
Next, the structure of the plurality of spray nozzles 21 is described in detail. In the present embodiment the plurality of spray nozzles 21 have structures identical to one another. Fig. 3 is a cross-sectional diagram showing one of the spray nozzles 21. As shown in Fig. 3, the spray nozzle 21 has a body 10, and an orifice 50 located downstream of the body 10 (on the downstream side of the direction of water flow).
The body 10 functions to guide to the orifice 50 water supplied from the water source, not shown, and to mix fine bubbles with the water supplied to the body 10. The body 10 of the present embodiment extends perpendicularly (vertically) and has the orifice 50 disposed downside thereof. In other words, the body 10 of the present embodiment guides, downward, the water supplied from the water source that is not shown. The orifice 50 functions to receive the water that has bubbles mixed therein by the body 10 and is guided to the orifice 50, stably feed this water mixed with bubbles to the outside of the spray nozzle 21, and expand the bubbles discharged from the orifice by taking advantage of the difference in pressure between the front and back of the orifice, to produce fine water drops to be sprayed.
The body 10 has a cylindrical contour with its axis longer than its diameter. In other words, the body 10 has a cylindrical contour extending perpendicularly. The body 10 has an air guide pipe (an outer tubal portion) 31 with a pipe wall formed into the shape of a pipe, and a water guide pipe (an inner tubal portion) 41 that has a pipe wall formed into the shape of a pipe and is disposed on the inside of the air guide pipe 31. In other words, the water guide pipe 41 is inserted into the air guide pipe 31.
The water guide pipe 41 is provided with a plurality of air introduction holes 43a pierced through the pipe wall thereof in a thickness direction. The pipe wall of the air guide pipe 31 is provided with an air supply portion 32 for supplying air to an air flow path F 1. The air supply portion 32 has a cylindrical shape in which is formed an air supply hole 32a communicating with the air flow path F1. The air feed piping section 71 shown in Fig. 1 is connected to this air supply portion 32.
An axial direction of the air guide pipe 31 corresponds to that of the water guide pipe 41. These axes are substantially aligned on the same straight line. In other words, the air guide pipe 31 and the water guide pipe 41 are formed into a pipe extending perpendicularly and are disposed in such a manner that the central axes thereof completely or roughly coincide with each other. The water guide pipe 41 has a cylindrical shape with an inner diameter D1 and outer diameter D2. The air guide pipe 31 has a cylindrical shape with an inner diameter D3, an outer diameter D4, and a length L1. The inner diameter D3 of the air guide pipe 31 is greater than the outer diameter D2 of the water guide pipe 41. An inner circumferential surface of the air guide pipe 31 and an outer circumferential surface of the water guide pipe 41 are separated from each other in a radial direction.
One end of the air guide pipe 31 (a downstream end: a lower end, in the present embodiment) and one end of the water guide pipe 41 (a downstream end: a lower end, in the present embodiment) are located at substantially the same position in the axial direction, and the other end of the water guide pipe 41 (an upstream end: an upper end, in the present embodiment) is located upstream of the other end of the air guide pipe 31 (an upstream end: an upper end, in the present embodiment). Specifically, the section near the other end of the water guide pipe 41 projects from the other end of the air guide pipe 31 to the upstream side. One end of the air flow path F1 (a lower end, in the present embodiment) is closed by the orifice 50, and the other end of the air flow path F1 (an upper end, in the present embodiment) is closed by a closing member 33.
The body 10 has an air guide portion 30, a water guide portion 40, and a bubble formation portion 43. In the present embodiment, the water guide portion 40 corresponds to a water flow path F2 which is defined by an inner circumferential surface of the pipe wall of the water guide pipe 41. The air guide portion 30 corresponds to the air flow path F1 which is defined by the outer circumferential surface of the water guide pipe 41 and an inner circumferential surface of the pipe wall of the air guide pipe 31. The bubble formation portion 43 has the plurality of air introduction holes 43a. The plurality of air introduction holes 43a are disposed at intervals in the circumferential direction and axial direction of the water guide pipe (the inner tubal portion) 41. The bore diameter of each of the air introduction holes 43a is smaller than that of the supply hole 32a of the air supply portion 32. The bubble formation portion 43 of the water guide pipe 41 corresponds to a cylindrical section between the air introduction hole 43a located at the uppermost stream and the air introduction hole 43a located at the lowermost stream. In the present embodiment, the water guide portion 40 guides, toward the orifice 50 disposed on the lower side of the body 10, water and air that is supplied from the air guide portion 30 into the water guide portion 40 via each of the air introduction holes 43a of the bubble formation portion 43 (i.e., water containing bubbles is guided perpendicularly downward). As a result, the water and the air (bubbles) are prevented from drifting as the water with bubbles in the water guide portion 40 flows. This consequently provides a great range of stability conditions in which sufficiently fine water drops are stably sprayed from a spray portion 51 (i.e., a range in which sufficiently fine water drops are stably sprayed remains wide even when the flow rates of the water and air supplied to the spray nozzle 21 are changed).
The orifice 50 has the spray portion 51 that produces fine water drops by expanding the bubbles by means of the difference in pressure between the front and back of the orifice 50 and sprays the fine water drops, and a closing portion 52 for closing one end of the air flow path F1. The spray portion 51 of the present embodiment sprays the fine water drops downward.
The closing portion 52 is a ring-shaped area located radially outward, and the spray portion 51 is an area located radially inward of the closing portion 52. The closing portion 52 has an inner surface (a surface on the upstream side) 52a that comes into abutment with one end of the air guide pipe 31 and one end of the water guide pipe 41 to close the end of the air flow path F 1.
The spray portion 51 has a communication hole communicating with the water flow path F2 and an external portion of the spray nozzle 21. The communication hole includes a tapering hole 51a with a tapering surface, which has an inner diameter becoming smaller toward the downstream side, and a spray hole 51 b that is located on the downstream side of the tapering hole 51a and sprays water. The distance between the spray hole 51 b and the heat exchanger 13 and the bore diameter of the spray hole 51b are set so that all or most of water drops sprayed from the spray hole 51b evaporates (vaporizes) while moving toward the heat exchanger 13. The bore diameter of the spray hole 51b is smaller than that of the air introduction holes 43a described hereinbelow.
The inner diameter of an upstream-side end portion of the tapering hole 51a is set to be approximately equal to or slightly smaller than the inner diameter D1 of one end of the water guide pipe 41. It is preferred that the end of the water guide pipe 41 and the upstream-side end portion of the tapering hole 51a be connected smoothly without a difference in height. An axial length of the tapering hole 51a is greater than an axial length L4 of the spray hole 51b. Water that flows through the tapering hole 51 a along the tapering surface toward the downstream side reaches the spray hole 51 b, with the flow velocity thereof gradually increased. The water reaching the spray hole 51b contains a large number of fine bubbles and is sprayed to the outside of the spray nozzle 21 along with these bubbles. When or after the water containing a large number of bubbles is sprayed from the spray hole 51b, the bubbles expand and burst, creating fine water drops.
Each of the spray nozzle 21 of the present embodiment includes a supply region A1 provided with the air supply hole 32a, a bubble formation region A2 provided with the plurality of air introduction holes 43a, and a guide region A3 for guiding to the spray portion 51 water that contains a large number of bubbles formed in the bubble formation region A2. The guide region A3 of the present embodiment guides downward (specifically, toward the spray portion 51 provided on the lower side of the body 10) the water containing a large number of bubbles. The guide region A3 also functions as a dispersion region (a mixing region) for dispersing a large number of bubbles in the water to some extent. This guide region A3 is located between the bubble formation region A2 and the spray portion 51. The bubble formation region A2 is located downstream of the supply region A1. In other words, the supply region A1, the bubble formation region A2, the guide region A3, and the spray portion 51 are arranged axially in this order toward the downstream side.
In the present embodiment, a length L2 of the bubble formation region A2 is greater than the inner diameter D1 of the water guide pipe 41, in the axial direction of the water guide pipe 41. Therefore, in a wide section in the axial direction, air is mixed into the water that flows through the water guide pipe 41. This can efficiently disperse and mix a large number of bubbles into the water. In addition, a length L3 of the guide region A3 is greater than the inner diameter D1 of the water guide pipe 41, in the axial direction of the water guide pipe 41. Therefore, the large number of bubbles mixed with the water in the bubble formation region A2 can effectively be dispersed in the water in the guide region A3.
Examples of the water source include a water line such as a water supply system. In this case, the liquid feed piping section 61 is connected to an upstream-side end portion of the water guide pipe 41. The liquid feed piping section 61 is connected to a hydrant, not shown. The water is sprayed from the spray nozzle 21 by driving the liquid feed pump 62 and the air feed pump 72. It should be noted that the liquid feed pump 62 can be omitted, and the water can be sprayed from the spray nozzle 21 by using the water pressure of a water line. In this case, the cost for installing the liquid feed pump 62 and the running cost for driving the liquid feed pump 62 can be reduced. A tank with water pooled therein may be used as the water source. In this case, the liquid feed piping section 61 is connected to a water inlet provided to the tank.
It is preferred that the average particle diameter of the water drops be, for example, 25 µm or less (it takes approximately 0.3 seconds or less for the water drops to evaporate). The average particle diameter of the water drops can be adjusted by adjusting the bore diameter of the spray hole 51b, the bore diameter of the air introduction hole 43a, the pressure applied to the water flow path F2, the pressure applied to the air flow path F1, and the like.
It is preferred that the ratio between a water supply amount and an air supply amount be, for example, 0.1 or less in weight ratio (weight of air/weight of water). Power required to supply air can be made small by adjusting the weight ratio to this range. Because the conventional two-fluid nozzle that injects air and water simultaneously from the spray hole creates fine water drops by adding shear force to the water at the pressure of the air, the air needs to be injected at high speeds, requiring a weight ratio (weight of air/weight of water) of 0.4 or more. For this reason, the conventional two-fluid nozzle requires great power to supply air.

Fig. 4 is a cross-sectional diagram showing a spray nozzle 21 of an outdoor unit 11 according to a second embodiment of the present invention. The outdoor unit 11 according to the second embodiment is different from the outdoor unit 11 of the first embodiment in terms of the structure of the spray nozzle 21. The same reference numerals as those shown in Fig. 3 are applied to the components of the second embodiment that are the same as those of the first embodiment, and hence descriptions thereof are omitted accordingly.
As shown in Fig. 4, the spray nozzle 21 according to the second embodiment has the supply region A1 provided with the air supply hole 32a, the bubble formation region A2, and the guide region A3 for guiding, to the spray portion 51, water containing a large number of bubbles formed in the bubble formation region A2, as with the first embodiment.
As shown in Fig. 4, the water guide pipe 41 is provided with the bubble formation portion 43. The bubble formation portion 43 includes a porous portion 42 made of a porous material. The porous portion 42 is formed from, for example, foam metal. The porous portion 42 has a large number of air introduction holes 43a. The bubble formation portion 43 corresponds to the region between the uppermost stream end of the porous portion 42 and the lowermost stream end of the same in the water guide pipe 41.
The porous portion 42 according to the present embodiment has a cylindrical shape with substantially the same diameter as the other parts of the water guide pipe 41; however, the shape of the porous portion 42 is not limited to a cylindrical shape. For instance, the water guide pipe 41 may be provided with a plurality of porous portions 42 that are disposed independently from each other in a scattering manner in a circumferential direction and/or a direction in which the water guide pipe 41 extends.
The porous portion 42 has a large number of continuous pores (the large number of air introduction holes 43a) configured by a series of pores. Therefore, air flowing through the air flow path F1 flows into the water flow path F2 via the large number of air introduction holes 43a. In the second embodiment, the presence of such porous portion 42 can make the porosity (void ratio) in the bubble formation region A2 greater than that of the first embodiment.

Fig. 5 is a cross-sectional diagram showing a spray nozzle 21 of an outdoor unit 11 according to a third embodiment of the present invention. The outdoor unit 11 according to the third embodiment is different from the outdoor unit 11 of the first embodiment in terms of the structure of the spray nozzle 21.
As shown in Fig. 5, the spray nozzle 21 according to the third embodiment includes the air guide portion 30, the water guide portion 40, the bubble formation portion 43, and the spray portion 51. The water guide portion 40 includes a cylindrical water guide pipe 44. The air guide portion 30 includes a cylindrical air guide pipe 34 connected to a side (pipe wall) of the water guide pipe 44. A leading end portion of the air guide pipe 34 is embedded in the water guide pipe 44. The spray portion 51 is provided at a leading end portion (downstream-side end portion) of the water guide pipe 44.
The spray nozzle 21 has the air flow path F1 and the water flow path F2. The water flow path F2 is a space defined by an inner circumferential surface of the water guide pipe 44. The air flow path F1 is a space defined by an inner circumferential surface of the air guide pipe 34. The outer diameter of the air guide pipe 34 is smaller than the outer diameter of the water guide pipe 44.
The spray portion 51 has a communication hole communicating with the water flow path F2 and an external portion of the spray nozzle 21. The communication hole includes the tapering hole 51 a with a tapering surface, which has an inner diameter becoming smaller toward the downstream side, and the spray hole 51b that is located on the downstream side of the tapering hole 51a and sprays water to the outside.
The air feed piping section 71 shown in Fig. 1 is connected to an upstream-side end portion of the air guide pipe 34, and the liquid feed piping section 61 shown in Fig. 1 is connected to an upstream-side end portion of the water guide pipe 44. Air supplied from an air source flows through the air guide pipe 34 and is then introduced into water through the plurality of air introduction holes 43a, the water flowing through the water guide pipe 44.
Fig. 6A is a perspective view showing the air guide pipe 34 of the spray nozzle 21 according to the third embodiment. As shown in Fig. 6A, the air guide pipe 34 has a cylindrical shape with outer and inner diameters set to be substantially uniform in an axial direction.
The bubble formation portion 43 is located at the leading end portion of the air guide pipe 34. The bubble formation portion 43 is a circular plate-like body which is disposed in such a manner as to cover an opening of the leading end portion of the air guide pipe 34. The plurality of air introduction holes 43a are formed in a scattering manner throughout the entire area of this plate-like body. This bubble formation portion 43 is disposed in the water flow path F2 of the water guide pipe 44.
In this spray nozzle 21, air is blown out of the plurality of air introduction holes 43a of the bubble formation portion 43 in a direction that intersects with a direction in which the water flows through the water flow path F2 (in a direction perpendicular to a direction of the water flow, in the present embodiment). According to such a configuration, the air blown out of the plurality of air introduction holes 43a can be made fine by shear force of the water flow. As a result, finer bubbles can be produced as compared to a case where the air is blown out of the plurality of air introduction holes 43a toward the downstream side in a direction parallel to the direction of the water flow in the water flow path F2.
Fig. 6B is a perspective view showing modification 1 of the air guide pipe 34. In this modification 1, an upstream-side section of the air guide pipe 34 has a cylindrical shape with the outer and inner diameters set to be substantially uniform in the axial direction, and a downstream-side (leading end-side) section of the air guide pipe 34 has a flare shape with the outer and inner diameters becoming large gradually toward the downstream side. The leading end portion of the air guide pipe 34 is provided with the bubble formation portion 43 having the plurality of air introduction holes 43a.
Compared to the aspect shown in Fig. 6A, the area of the plate-like bubble formation portion 43 can be made greater than that illustrated in modification 1 shown in Fig. 6B. Thus, when the number of air introduction holes 43a shown in Fig. 6A is same as that shown in Fig. 6B, the space between the air introduction holes 43a illustrated in modification 1 can be made wider than that illustrated in the aspect shown in Fig. 6A, preventing reaggregation of the bubbles.
Fig. 6C is a perspective view showing modification 2 of the air guide pipe 34. In this modification 2, the air guide pipe 34 has a cylindrical shape with the outer and inner diameters set to be substantially uniform in the axial direction. The leading end portion of the air guide pipe 34 is provided with the bubble formation portion 43. This bubble formation portion 43 is a porous body (porous portion) made of a porous material. The porous portion has the large number of air introduction holes 43a. The porous body is formed from, for example, foam metal. The porous body has a large number of continuous pores (the large number of air introduction holes 43a) configured by a series of pores. In modification 2, the presence of such porous portion can make the porosity (void ratio) in the bubble formation portion 43 greater than that illustrated in the aspects shown in Figs. 6A and 6B.
As described above, in each of the embodiments, each spray nozzle 21 has the air guide portion 30 through which air flows, the water guide portion 40 through which water flows, the bubble formation portion 43 that forms a large number of bubbles in the water by allowing the air of the air guide portion 30 to flow into the water of the water guide portion 40, and the spray portion 51 that is located downstream of the water guide portion 40 in the direction of water flow and sprays, to the outside, the water containing the large number of bubbles which is in the water guide portion 40. Therefore, each of the embodiments can reduce the power of the entire air conditioning device while preventing corrosion of the heat exchanger.
The first and second embodiments each employ the double pipe structure in which the air guide pipe 31 is disposed in such a manner as to surround the outer circumference of the water guide pipe 41 provided with one or more air introduction holes 43a. Therefore, each of the spray nozzles 21 having the water guide portion 40, the air guide portion 30, and the bubble formation portion 43 can be produced inexpensively.
In the first and second embodiments, the plurality of air introduction holes 43a are disposed at intervals in the circumferential direction of the water guide pipe 41 and the direction in which the water guide pipe 41 extends. Therefore, unlike a configuration in which only one air introduction hole 43a is provided in the water guide pipe 41, the air can be let flow into the water of the water guide pipe 41 from a plurality of sections that are disposed at intervals in the circumferential direction and the direction in which the water guide pipe 41 extends. As a result, the water flowing through the water guide pipe 41 can have bubbles dispersed efficiently therein. In addition, compared to the configuration in which only one air introduction hole 43a is provided, the resistance for letting the air flow into the water is smaller, and the pressure required to let the air flow into the water can be set lower, further reducing the power.
In the second embodiment, the porosity in the bubble formation portion 43 can be increased because the bubble formation portion 43 includes the porous portion 42 with the plurality of air introduction holes 43a. Such configuration can further reduce the resistance created when the air is introduced into the water of the water guide pipe 41 via the bubble formation portion 43. This can further reduce the pressure required to let the air flow into the water.
In the second embodiment, variations in bore diameter of the plurality of air introduction holes (43a) can be prevented by forming the porous portion 42 with foam metal, so that the diameter of bubbles to be formed in the bubble formation portion 43 can be made somewhat uniform, reducing variations in diameter of water drops sprayed by the spray portion 51.
The third embodiment has the water guide pipe 44, and the air guide pipe 34 that is connected to the water guide pipe 44 and has one or more air introduction holes 43a at the end portion thereof on the water guide pipe 44 side. The water guide portion 40 includes the water flow path F2 defined by the inner circumferential surface of the water guide pipe 44. The air guide portion 30 has the air flow path F1 defined by the inner circumferential surface of the air guide pipe 34. The bubble formation portion 43 includes one or more air introduction holes 43a. In the third embodiment, the spray nozzle 21 can be configured with such a simple structure.
Each of the embodiments further has the charging mechanism 80 for electrically charging the water sprayed from each spray nozzle 21. Each of the water drops sprayed from the spray portion 51 moves through the air while being electrically charged. As a result, the water drops repel each other with a force of electrostatic repulsion, preventing reaggregation of the water drops. This can also prevent an increase in water drop diameters due to reaggregation. The electrostatic repulsion between the water drops can spread the water drops across a wide area.
In each of the embodiments, the water guide portion 40 vertically guides the water containing bubbles. Such configuration can prevent the water and the air (bubbles) from drifting as the water with bubbles in the water guide portion 40 flows. This consequently provides a great range of stability conditions in which sufficiently fine water drops are stably sprayed from the spray portion 51 (i.e., a range in which sufficiently fine water drops are stably sprayed remains wide even when the flow rates of the water and air supplied to the spray nozzles 21 are changed). In other words, when vertically guiding the water containing bubbles, such configuration can prevent the air (bubbles) from coming together on the upper side when the water containing the bubbles flows through the water guide portion 40, and from flowing out of balance along with the water (drifting), as in a case where the water containing the bubbles is guided in another direction (i.e., horizontally). Consequently, even with different flow rates of the water and air or other conditions for supplying the water and air to the spray nozzles 21, defective spray (where sufficiently fine water drops are not produced or where the size of the water drops fluctuates, etc.) caused due to the drift can be minimized on a wide scale. As a result, sufficiently fine water drops can stably be sprayed from the spray portion 51.
Moreover, according to each of the embodiments, the water guide portion 40 guides the water containing bubbles downward, and the spray portion 51 sprays this water downward. Thus, compared to the configuration in which the water guide portion 40 guides the water containing bubbles in a different direction (e.g., upward or horizontally) and the spray portion 51 sprays this water in the direction, the maximum range of stability conditions (the water/air supply conditions in which sufficiently fine water drops are stably sprayed from the spray portion 51) can be obtained.
In addition, even when the water drops are large and cannot evaporate easily, the spray portion 51 sprays such large water drops downward, and the resultant force of the downward spray motion and gravity added to the water drops cause the water drops to fall downward (e.g., onto the installation surface of the outdoor unit 11 or the like) across substantially the horizontal flow of air directed toward the heat exchanger 13. This configuration can prevent the heat exchanger 13 from getting wet by the large water drops.

The embodiments of the present invention are described above; however, the present invention is not limited to these embodiments and can be modified and improved in various ways without departing from the scope of the present invention.
Each of the embodiments describes the example in which the spray nozzles 21 are disposed horizontally at intervals on the three side panels 12a, 12b, 12c facing the heat exchanger 13 so as to be able to spray water drops downward and to be at the same height, as shown in Fig. 2. However, the present invention is not limited to this configuration. As long as the cooling effect of the spray device 20 can be provided substantially uniformly to substantially the entire heat exchanger 13, the spray nozzles 21 may be disposed as shown in, for example, the outdoor unit 11A of Fig. 7, so as to be able to spray water drops toward the heat exchanger 13 (i.e., to spray water drops along the direction of the outside air flowing toward the heat exchanger 13). A specific example of this configuration is described below.
Each of the spray nozzles 21 is disposed in such a manner as to spray water drops toward the heat exchanger 13. In other words, each of the spray nozzles 21 is disposed, with an axial direction thereof being directed along the direction of the flow of air (air stream). The water drops sprayed from each spray nozzle 21 move toward the heat exchanger 13 along the air stream direction while spreading radially. All or most of the water drops vaporize prior to reaching the heat exchanger 13.
When disposing each of the spray nozzles 21 in the outdoor unit 11A in such a manner as to spray water drops horizontally or slightly obliquely as described above, it is preferred that the plurality of spray nozzles 21 be disposed at intervals on the three side panels 12a, 12b, 12c facing the heat exchanger 13, as shown in Fig. 8. More specifically, the plurality of spray nozzles 21 are disposed vertically and horizontally at an interval of, for example, several tens of centimeters in a scattering manner, based on the range in which the water drops from each spray nozzle 21 are spread, i.e., the range in which the air flowing toward the heat exchanger 13 is cooled by each spray nozzle 21. In this arrangement example, the diameter of the range in which the water drops sprayed from each spray nozzle 21 are spread is approximately 50 cm, the width of the side panel 12a approximately, for example, 100 cm, the width of the side panels 12b, 12c approximately 30 cm, and the height of each side panel approximately 80 cm. Four spray nozzles 21 are arranged vertically and horizontally on the side panel 12a, and two spray nozzles 21a are arranged vertically on each of the side panels 12b and 12c.
Arranging the spray nozzles 21 in this manner results in providing the cooling effect of the spray device 20 substantially uniformly to substantially the entire heat exchanger 13.
In a case where the spray nozzles 21 are disposed in such a manner as to spray water drops toward the heat exchanger 13 (i.e., along the direction of outside air flowing toward the heat exchanger 13), the plurality of spray nozzles 21 may be disposed unevenly so that, for example, a better cooling effect can be provided to some areas of the heat exchanger 13 than the other areas. A specific example of this configuration is described below.
Fig. 9 is a schematic diagram for explaining another example of the arrangement of the spray nozzles 21 in relation to the heat exchanger 13. The spray nozzles 21 are not shown in Fig. 9. The heat exchanger 13 shown in Fig. 9 has three heat-transfer pipes P1, P2, P3. These three heat-transfer pipes P1, P2, P3 each have an independent refrigerant path. Each of the heat-transfer pipes has a refrigerant path that meanders through the heat exchanger 13, with a part bent at either end in a width direction of the heat exchanger 13. Each heat-transfer pipe is provided with a refrigerant inlet at its one end (a right end, in Fig. 9), and a refrigerant outlet at its other end (a left end, in Fig. 9).
In order to change the refrigerant into supercooled liquid with a predetermined supercooling degree in the heat exchanger 13, it is preferred that supercooling regions (downstream-side end regions) SB1, SB2, SB3 in the vicinity of the refrigerant outlets of the heat-transfer pipes P1, P2, P3 be cooled intensively. In the arrangement example shown in Fig. 9, the plurality of spray nozzles 21 are disposed mainly at the positions that face the supercooling regions SB1, SB2, SB3 in the heat exchanger 13.
Specific examples of disposing the spray nozzles 21 mainly in some regions include, for example, an aspect in which the plurality of spray nozzles 21 are disposed only at the positions facing the supercooling regions SB1, SB2, SB3 in the heat exchanger 13, and an aspect in which the spray nozzles 21 are disposed more densely at the positions facing the supercooling regions SB1, SB2, SB3 than at the positions facing the other regions.
In addition, for example, each of the spray nozzles 21 may be disposed in such a manner as to spray water drops upward, as shown in Fig. 10.
In this case, the spray nozzles 21 are disposed outside and below the heat exchanger 13 in the outdoor unit 11B. In this configuration, in each spray nozzle 21 the water guide portion 40 guides the water containing bubbles upward, and the spray portion 51 sprays, upward, this water containing many bubbles which is guided by the water guide portion 40. The plurality of spray nozzles 21 are disposed horizontally at intervals on the three side panels 12a, 12b, 12c facing the heat exchanger 13, in such a manner as to spray water drops upward and to be at the same height (below the heat exchanger 13).
By allowing the water guide portion 40 to guide the water containing bubbles upward and allowing the spray portion 51 to spray this water upward, the air and water are prevented from drifting as the water with bubbles in the water guide portion 40 flows, allowing the spray portion 51 to stably spray sufficiently fine water drops.
Furthermore, because each spray nozzle 21 sprays the water drops upward from below toward the outside air flowing toward the heat exchanger 13 which has wind velocity distribution where the outside air accelerates on the upper side of the heat exchanger 13 (the wind velocity distribution resulting from the positional relationship between the heat exchanger 13 and the fan 14), flight durations that are long enough for the water drops to vaporize prior to reaching various sections of the heat exchanger 13 can be ensured as the water drops flow toward the various sections in a height direction of the heat exchanger 13. This mechanism is described below specifically.
In the outdoor unit 11B in which the heat exchanger 13 is provided upright with respect to the installation surface (horizontal surface) and the fan 14 is disposed above and horizontally inward of the heat exchanger 13 in the case 2 (see Fig. 10), a wind velocity distribution shown in Fig. 11 is formed in which the air flows non-uniformly toward the heat exchanger 13 and accelerates on the upper side of the heat exchanger 13. This is because the air suctioned through the air inlets (not shown) of the side panels 12a, 12b, 12c of the case 2 flows faster near the fan 14 (the upper side). Note that the horizontal arrows directed toward the heat exchanger 13 indicate flows of the outside air (air) formed as a result of discharging the air of the outdoor unit 11B (the case 2) to the outside by means of the fan 14 (see the upward arrows in Fig. 11), the outside air flowing toward the heat exchanger 13. The lengths of the arrows showing these flows of air represent the wind velocities in the corresponding height positions.
In this state, when each spray nozzle 21 sprays the water drops upward from below the heat exchanger 13, the distance between the spray nozzle 21 below the heat exchanger 13 and the upper part of the heat exchanger 13 increases. As a result, the flight durations that are long enough for the droplets to vaporize can be ensured, the droplets being the water drops sprayed from the spray nozzle 21 and flowing toward the upper part of the heat exchanger 13 (see the arrow α in Fig. 11). Therefore, despite the fast flow of the outside air flowing toward the upper part of the heat exchanger 13, the water drops can vaporize prior to reaching the upper part of the heat exchanger 13. On the other hand, although the distance between the spray nozzle 21 disposed below the heat exchanger 13 and the lower part of the heat exchanger 13 is short, the fact that the air flows slowly toward this section of the heat exchanger 13 can ensure the flight durations that are long enough for the water drops to evaporate, the water drops being sprayed from the spray nozzle 21 and flowing toward the lower part of the heat exchanger 13 (see the arrow β in Fig. 11). Consequently, the water drops can vaporize prior to reaching the lower part of the heat exchanger 13. As described above, in the outdoor unit 11B, the positional relationship between the heat exchanger 13 and the fan 14 creates the wind velocity distribution where the air flowing toward the heat exchanger 13 is faster at the upper side thereof. In such a configuration where the water drops are sprayed upward from below the heat exchanger 13, the distance between the spray nozzle 21 and the heat exchanger 13 in which the water drops travel to the heat exchanger 13 is longer toward the height positions of the heat exchanger 13 where the air flows at higher velocities, and the distance between the spray nozzle 21 and the heat exchanger 13 in which the water drops travel to the heat exchanger 13 is shorter toward the height positions of the heat exchanger 13 where the air flows at lower velocities. Owing to this configuration, the flight durations long enough for the water drops to vaporize can be ensured. Consequently, the water drops sprayed from the spray nozzle 21 vaporize prior to reaching the heat exchanger 13, resulting in preventing the heat exchanger 13 from getting wet by the water drops sprayed from the spray nozzle 21.
In each of the embodiments, each spray nozzle 21 is so shaped as to allow the entire water guide portion 40 to guide water vertically; however, the shape of the spray nozzle 21 is not limited thereto. In other words, each spray nozzle 21 may be configured to allow a section corresponding at least to the guide region A3 of the water guide portion 40 to guide water vertically (downward, in each of the embodiments). For example, in the water guide portion 40 described in each embodiment, a section downstream of at least the bubble formation portion 43 (to be more specific, a section of the water guide pipe 41 that is downstream of the lowermost stream air introduction hole 43 a) may guide at least, vertically, the water containing bubbles toward the spray portion 51. This configuration can effectively prevent the air and the water from drifting as the water with bubbles in the water guide portion 40 flows, and stably spray sufficiently fine water drops from the spray portion 51.
In each of the embodiments, an electric current is applied to the water supplied from the water supply mechanism 60 (electrifying the water) as shown in Fig. 1, to charge the water sprayed from the spray device 20. However, the mechanism of electrically charging the water is not limited thereto. For example, the water to be sprayed may be charged by means of static induction, as shown in Figs. 12A and 12B, or by discharging electricity in the air, as shown in Fig. 13. This mechanism is described below specifically.
First of all, the method of using static induction is described with reference to Figs. 12A and 12B. Fig. 12A is a schematic diagram for explaining modification 1 of a charging mechanism 80, and Fig. 12B an enlarged perspective view for explaining one of the spray nozzles 21 and an induction electrode 85.
The liquid feed piping section 61 of the water supply mechanism 60 of the spray device 20 does not have to be provided with the insulating piping section 61b described in the embodiments. In other words, the entire liquid feed piping section 61 is formed from a conductive member. It should be noted that, in the liquid feed piping section 61, at least the region between the spray nozzle 21 and the section connected to an electrode of the charging power supply 81 may be formed from a conductive member, and, for example, the upstream part of the section connected to the electrode may be formed from an insulating member.
The charging mechanism 80 has the charging power supply 81 and the induction electrode 85. The charging power supply 81 has one of its electrodes connected to the spray nozzle 21, and the other one to the induction electrode 85. The charging power supply 81 can therefore apply a voltage between the spray nozzle 21 and the induction electrode 85. In the present embodiment, the positive electrode is connected to the spray nozzle 21, and the negative electrode to the induction electrode 85. Therefore, the water (water drops) sprayed from the spray nozzle 21 is charged positively. The positive electrode of the charging power supply 81 is grounded such that the spray nozzle 21 becomes the ground potential.
The induction electrode 85 is disposed with a predetermined distance from the spray nozzle 21, and generates static induction in water passing through the spray nozzle 21, by means of a predetermined voltage applied between the induction electrode 85 and the spray nozzle 21. More specifically, the induction electrode 85 is an annular electrode with an inner diameter larger than an outer diameter of the spray nozzle 21 (see Fig. 12B). This induction electrode 85 is disposed at the leading end of the spray nozzle 21 in the axial direction of the spray nozzle 21 or at a position slightly close to the base end of the spray nozzle 21 with respect to the leading end, in such a manner that a central axis of the induction electrode 85 matches the axis (central axis) of the spray nozzle 21. The induction electrode 85 may be disposed in front of the spray nozzle 21 (toward the heat exchanger) in the axial direction of the spray nozzle 21. However, in view of the possibility of contamination of the induction electrode 85 by the mist-like water sprayed from the spray nozzle 21, it is preferred that the induction electrode 85 be disposed at the leading end of the spray nozzle 21 or at the position slightly close to the base end with respect to the leading end, as described above.
In this charging mechanism 80, the charging power supply 81 applies a predetermined voltage (e.g., 5000 V to 10000 V) between the spray nozzle 21 and the induction electrode 85, and thereby static induction is generated in the water passing through the spray nozzle 21. The water in this state is sprayed from the spray nozzle 21, charging the resultant water drops.
Next is described, with reference to Fig. 13, the method of discharging electricity to charge the water to be sprayed. Fig. 13 is a schematic diagram for explaining modification 2 of the charging mechanism 80.
As with the flow path portion of the static induction method, the liquid feed piping section 61 of the water supply mechanism 60 of the spray device 20 in this method does not have to be provided with the insulating piping section described in the embodiments.
The charging mechanism 80 has the charging power supply 81 and a pair of discharge electrodes (a first discharge electrode 86 and a second discharge electrode 87).
The charging power supply 81 has the positive electrode thereof connected to the first discharge electrode 86 and the negative electrode to the second discharge electrode 87. The negative electrode is grounded such that the second discharge electrode 87 becomes the ground potential. The charging power supply 81 therefore can apply a voltage between the first discharge electrode 86 and the second discharge electrode 87 (between the pair of discharge electrodes).
The pair of discharge electrodes 86, 87 is disposed in such a manner as to sandwich a region through which the mist-like water sprayed from the spray nozzle 21 passes.
In this charging mechanism 80, the charging power supply 81 applies a predetermined voltage (e.g., 5000 V to 10000 V) between the pair of the discharge electrodes 86, 87, and thereby a discharge (e.g., a corona discharge) is generated between the discharge electrodes 86, 87. Due to this discharge, the water drops passing between the discharge electrodes 86, 87 are charged. In this case, the water drops are charged positively.
In the charging mechanism (the charging mechanism in the method of electrifying the water) 80 according to each embodiment, the water flowing through the insulating piping section 61b is electrified due to the application of a voltage between the spray nozzle 21 and the metal piping section 61 a, with the insulating piping section 61b therebetween, as shown in Fig. 1. As a result, the water to be sprayed becomes charged, but the position to electrify the water is not limited to the insulating piping section 61 b. For instance, when the water supply mechanism 60 is provided with a water source such as a tank, water pooled in this water source may be electrified to charge the water, and the charged water may be supplied to the spray nozzle. This is a method of charging water through electrification, but in this case the water guide pipe of the water supply mechanism does not have to be provided with the insulating piping section.
Each of the embodiments describes the example in which the spray device 20 has the charging mechanism 80 as a charger; however, the charger is not a required component in the present invention and therefore can be omitted. In case of omitting the charger, the resin piping section 61b is not required, so the entire liquid feed piping section 61 can be formed using the metal piping section 61 a.
The first and second embodiments each describe the example of providing the guide region A3 between the bubble formation region A2 and the spray portion 51; however, the guide region A3 can be omitted. In such a case, the air introduction holes 43a can be formed in the vicinity of the tapering hole 51 a of the water guide pipe 41. However, in the aspect in which the guide region A3 is provided as shown in Fig. 3, the large number of bubbles mixed in the water can be dispersed in the water more easily than when the guide region A3 is not provided. Thus, more uniform water drops can be sprayed from the spray portion 51.
Each of the embodiments illustrates the example of positioning the fan 14 downstream of the heat exchanger 13 in the direction of the airflow. However, the present invention is not limited to this configuration. For example, the fan 14, the spray nozzles 21, and the heat exchanger 13 may be disposed in this order toward the downstream side in the direction of the airflow.
The second and third embodiments each describe the example of forming the porous portion 42 with foam metal. However, the present invention is not limited to this configuration. The porous portion 42 may not necessarily be formed from metal but can be formed from, for example, synthetic resin.
The third embodiment illustrates the situation where the air guide pipe (the second guide pipe) 34 is connected to a side of the water guide pipe (the first guide pipe) 44. However, the present invention is not limited to this configuration. For instance, the air guide pipe 34 may be connected to a longitudinal end portion (upstream-side end portion) of the water guide pipe 44. In this case, the direction in which the water guide pipe 44 extends is substantially the same as the direction in which the air guide pipe 34 extends.
The embodiments are summarized hereinbelow.

(1) According to each of the embodiments, the present invention can reduce the power of the entire air conditioning device while preventing corrosion of the heat exchanger thereof. This mechanism is described hereinafter specifically.

In other words, in each of the embodiments, water containing a large number of bubbles are formed in the water guide portion (40), and this water containing a large number of bubbles is sprayed from the spray portion (51). When or after the water containing bubbles is sprayed from the spray portion (51), the bubbles burst, creating fine droplets. Thus created fine droplets easily vaporize (evaporate) prior to reaching the heat exchanger (13), preventing adherence of the droplets to the heat exchanger (13). In this manner, corrosion of the heat exchanger (13) is prevented.
Once the droplets vaporize prior to reaching the heat exchanger (13), the air flowing toward the heat exchanger (13) is cooled by its latent heat (vaporization heat). Therefore, because the temperature of the air passing through the heat exchanger (13) becomes lower than that obtained when the water is not sprayed, the power required to drive the compressor, the fan and the like at the time of the cooling operation of the air conditioning device can be reduced. Moreover, in the present configuration, no large power is required to spray air to water at high speeds through the injection hole of the spray nozzle, as seen in the conventional two-fluid nozzle. In other words, because the present configuration only requires power for forming a large number of bubbles in the water flowing through the water guide portion (40), the amount of air required is lower than that of the conventional nozzle, enabling to make the power required to feed air lower than that required in the conventional nozzle. This configuration can effectively reduce the power of the entire air conditioning device.

(2) In the outdoor unit, as an example, the water guide portion (40) has a pipe wall shaped into a pipe, and also has one or more air introduction holes (43a) penetrating the pipe wall in the thickness direction. The air guide portion (30) is shaped into a pipe so as to surround the outer circumference of the water guide portion (40).

According to this configuration, each spray nozzle (21) can be produced at low costs by adopting the double pipe structure in which the air guide portion (30) is disposed so as to surround the outer circumference of the water guide portion (40) provided with one or more air introduction holes (43a).

(3) In the outdoor unit, it is preferred that the water guide portion (40) have the plurality of air introduction holes (43a) and that the plurality of air introduction holes (43a) be disposed at intervals in the circumferential direction of the water guide portion (40) and the direction in which the water guide portion (40) extends.

According to this configuration, because the plurality of air introduction holes (43a) are provided at intervals in the circumferential direction of the water guide portion (40) and the direction in which the water guide portion (40) extends, the air can be let flow into the water of the water guide portion (40) through the plurality of intervals provided in the circumferential direction and the direction in which the water guide portion (40) extends, unlike a configuration having one air introduction hole (43a). Therefore, the bubbles can efficiently be dispersed in the water flowing through the water guide portion (40). In addition, the resistance for letting the air flow in the water becomes smaller than that obtained in the configuration having one air introduction hole (43a), enabling to lower the pressure required to let the air flow into the water. As a result, the power can further be reduced.

(4) In the outdoor unit, the water guide portion (40) may be shaped into a pipe and have, at least partially, the porous portion (42), and the air guide portion (30) may be shaped into a pipe so as to surround the outer circumference of the water guide portion (40).

According to this configuration, because the water guide portion (40) has the porous portion (42), the bubbles can have a uniform diameter, reducing variations in diameter of droplets sprayed by the spray portion (51).

(5) In the outdoor unit, the porous portion (42) is formed from foam metal.

According to this configuration, the porous portion (42) is formed from foam metal. Owing to a large porosity of the porous portion (42), the resistance that is generated when introducing the air into the water of the water guide pipe (41) through the porous portion (42) can be reduced. As a result, the pressure required to let the air flow into the water can be lowered.

(6) In the outdoor unit, the water guide portion (40) may be shaped into a pipe. The air guide portion (30) may also be shaped into a pipe and have a leading end portion thereof connected to the water guide portion (40).

According to this configuration, each of the spray nozzles 21 can be configured with a simple structure in which the air guide portion (30) is connected to the water guide portion (40).

(7) In the outdoor unit, it is preferred that the air guide portion (30) have the porous portion (42) at the leading end portion thereof.

According to this configuration, because the air guide portion (30) has the porous portion (42), the bubbles can have a uniform diameter, reducing variations in diameter of droplets sprayed by the spray portion (51).

(8) It is preferred that the outdoor unit further have a charger (80) for electrically charging the water sprayed from the spray nozzle (21).

According to this configuration, the droplets to be sprayed from the spray portion (51) move through the air while being charged. This means that the droplets repel each other with a force of electrostatic repulsion, preventing reaggregation of the droplets. This can also prevent an increase in droplet diameters due to reaggregation. The electrostatic repulsion between the droplets can spread the droplets across a wide area.

(9) In the outdoor unit (11) of the air conditioning device, it is preferred that the water guide portion (40) vertically guide the water containing bubbles.

In such an aspect where the water guide portion (40) vertically guides the water containing bubbles, the water and the air (bubbles) are prevented from drifting as the water with bubbles in the water guide portion (40) flows. This consequently provides a great range of stability conditions in which sufficiently fine droplets are stably sprayed from the spray portion (51). In other words, a range in which sufficiently fine droplets are stably sprayed remains wide even when the flow rates of the water and air supplied to the spray nozzle (21) are changed. Specifically, when perpendicularly guiding the water containing bubbles, the above-described configuration can prevent the air (bubbles) from coming together on the upper side when the water containing the bubbles flows through the water guide portion (40), and then flowing out of balance along with the water (drifting), as in a case where the water containing bubbles is guided in another direction (i.e., horizontally). Consequently, even with different flow rates of the water and air or other conditions for supplying the water and air to the spray nozzle (21), defective spray (where sufficiently fine droplets are not produced or where the size of the droplets fluctuates, etc.) caused due to the drift can be minimized on a wide scale. As a result, sufficiently fine droplets can stably be sprayed from the spray portion (51).

(10) In such a case where the guide water portion (40) vertically guides the water containing bubbles, it is preferred that the spray nozzle (21) be disposed outside the heat exchanger (13) in the outdoor unit (11), that the water guide portion (40) guide the water containing bubbles downward, and that the spray portion (51) be disposed on the lower side of the water guide portion (40) and spray, downward, the water containing a large number of bubbles that is guided by the water guide portion (40).

Compared to a configuration in which the water guide portion (40) guides the water containing bubbles in a different direction (e.g., upward or horizontally) and the spray portion (51) sprays this water in the direction, allowing the water guide portion (40) to guide the water containing bubbles downward and the spray portion (51) to spray this water downward can provide the maximum range of stability conditions. In other words, this configuration can realize the maximum range of water/air supply conditions in which sufficiently fine droplets are stably sprayed from the spray portion (51).
Moreover, because even large droplets are sprayed downward from the spray portion (51), these large droplets are dropped across a substantially horizontal flow of air directed toward the heat exchanger (13) by the force of spray and gravity added to these droplets. Therefore, even when large droplets are sprayed, this configuration can prevent adherence of the large droplets to the heat exchanger (13), whereby the heat exchanger (13) is prevented from being wet

(11) When the water guide portion (40) vertically guides the water containing bubbles, the outdoor unit (11) may have the fan (14) that forms flow of air directed toward the heat exchanger (13), wherein the fan (14) is disposed above and inward of the heat exchanger (13) in the outdoor unit (11) and discharges upward, to the outside of the outdoor unit (11), air that has flowed into the outdoor unit (11) and been subjected to heat exchange by the heat exchanger (13), the spray nozzle (21) is disposed further toward an outer side than the heat exchanger (13) in the outdoor unit (11), the water guide portion (40) guides the water containing bubbles upward, and wherein the spray portion (51) is disposed on the upper side of the water guide portion (40) and sprays upward the water containing a large number of bubbles that is guided by the water guide portion (40).

By allowing the water guide portion (40) to guide the water containing bubbles upward and allowing the spray portion (51) to spray this water upward, the air and water are prevented from drifting as the water with bubbles in the water guide portion (40) flows, allowing the spray portion (51) to stably spray sufficiently fine droplets.
In addition, because the spray nozzle (21) sprays droplets upward with respect to the flow of air directed toward the heat exchanger (13), the flow of air having a wind velocity distribution where the air accelerates on the upper side of the heat exchanger (13) (the wind velocity distribution resulting from the positional relationship between the heat exchanger (13) and the fan (14): see Fig. 11), flight durations that are long enough for the droplets to vaporize prior to reaching various sections of the heat exchanger (13) can be ensured, the droplets flowing toward the various sections in a height direction of the heat exchanger (13). Such a configuration can prevent the heat exchanger (13) from getting wet by the droplets. This mechanism is described hereinbelow specifically.
The distance between the spray nozzle (21) below the heat exchanger (13) and the upper part of the heat exchanger (13) increases. As a result, flight durations that are long enough for the droplets to vaporize can be ensured as the droplets are sprayed from the spray nozzle (21) and flow toward the upper part of the heat exchanger (13). Therefore, despite the fast flow of the air flowing toward the upper part of the heat exchanger (13), the droplets can vaporize prior to reaching the upper part of the heat exchanger (13). On the other hand, although the distance between the spray nozzle (21) below the heat exchanger (13) and the lower part of the heat exchanger (13) is short, the fact that the air flows slowly toward this section can ensure the flight durations that are long enough for the droplets to vaporize as the droplets are sprayed from the spray nozzle (21) and flow toward the lower part of the heat exchanger (13). Consequently, the water drops can vaporize prior to reaching the lower part of the heat exchanger (13). As described above, in the outdoor unit (11), the positional relationship between the heat exchanger (13) and the fan (14) creates the wind velocity distribution where the air flowing toward the heat exchanger (13) is faster at the upper side thereof. In such a configuration where the droplets are sprayed upward from the spray nozzle (21), the distance between the spray nozzle (21) and the heat exchanger (13) in which the droplets travel to the heat exchanger (13) becomes longer toward the height positions of the heat exchanger (13) where the air flows at higher velocities, and the distance between the spray nozzle (21) and the heat exchanger (13) in which the droplets travel to the heat exchanger (13) becomes shorter toward the height positions of the heat exchanger (13) where the air flows at lower velocities. Owing to this configuration, the flight durations long enough for the droplets to vaporize can be ensured. Consequently, the droplets sprayed from the spray nozzle (21) vaporize prior to reaching the heat exchanger (13), resulting in preventing the heat exchanger (13) from getting wet by the droplets sprayed from the spray nozzle (2).
As described above, each of the embodiments can reduce the power of the entire air conditioning device while preventing corrosion of the heat exchanger thereof.

Explanation of Reference Numerals

11, 11 A, 11B: Outdoor unit
13: Heat exchanger
20: Spray device
21: Spray nozzle
30: Air guide portion
31: Air guide pipe
34: Air guide pipe (second guide pipe)
40: Water guide portion
41: Water guide pipe
42: Porous body
44: Water guide pipe (first guide pipe)
50: Orifice
51: Spray portion
80: Charger

Claims

An outdoor unit for an air conditioning device, comprising:
a heat exchanger; and

a spray nozzle for spraying water to air flowing toward the heat exchanger,

wherein the spray nozzle has:
an air guide portion through which air flows;

a water guide portion through which water flows and which causes the air flowing through the air guide portion to flow into water to form water containing a large number of bubbles; and

a spray portion that is located downstream of the water guide portion in a direction of water flow and sprays, to the outside, the water containing a large number of bubbles which is formed in the water guide portion.
The outdoor unit for an air conditioning device according to claim 1, wherein
the water guide portion has a pipe wall shaped into a pipe and also has one or a plurality of air introduction holes penetrating the pipe wall in a thickness direction, and
the air guide portion is shaped into a pipe so as to surround an outer circumference of the water guide portion.
The outdoor unit for an air conditioning device according to claim 2, wherein
the water guide portion has the plurality of air introduction holes, and
the plurality of air introduction holes are provided at intervals in a circumferential direction of the water guide portion and a direction in which the water guide portion extends.
The outdoor unit for an air conditioning device according to claim 1, wherein
the water guide portion is shaped into a pipe and has, at least partially, a porous portion, and
the air guide portion is shaped into a pipe so as to surround an outer circumference of the water guide portion.
The outdoor unit for an air conditioning device according to claim 4, wherein the porous portion is formed from foam metal.
The outdoor unit for an air conditioning device according to claim 1, wherein
the water guide portion is shaped into a pipe, and
the air guide portion is shaped into a pipe and has a leading end portion thereof connected to the water guide portion.
The outdoor unit for an air conditioning device according to claim 6, wherein the air guide portion has a porous portion at a leading end portion thereof.
The outdoor unit for an air conditioning device according to any one of claims 1 to 7, further comprising:
a charger that electrically charges water sprayed from the spray nozzle.
The outdoor unit for an air conditioning device according to any one of claims 1 to 8, wherein the water guide portion vertically guides water containing bubbles.
The outdoor unit for an air conditioning device according to claim 9, wherein
the spray nozzle is disposed outside the heat exchanger in the outdoor unit,
the water guide portion guides water containing bubbles downward, and
the spray portion is disposed on a lower side of the water guide portion and sprays, downward, the water containing a large number of bubbles which is guided by the water guide portion.
The outdoor unit for an air conditioning device according to claim 9, further comprising:
a fan that forms flow of air directed toward the heat exchanger,

wherein

the fan is disposed above and inward of the heat exchanger in the outdoor unit and discharges upward, to the outside of the outdoor unit, air that has flowed into the outdoor unit and been subjected to heat exchange by the heat exchanger,

the spray nozzle is disposed further toward an outer side than the heat exchanger in the outdoor unit,

the water guide portion guides water containing bubbles upward, and

the spray portion is disposed on an upper side of the water guide portion and sprays upward the water containing a large number of bubbles which is guided by the water guide portion.