JP6340111B1 - Air conditioner indoor unit - Google Patents

Abstract

To prevent water from leaking outside during freezing and cleaning. An indoor unit 2 of an air conditioner includes a heat exchanger 16 that exchanges heat between air and a refrigerant, a drain pan 17 that receives drain water dripped from the heat exchanger 16, and a surface of the heat exchanger. And a control unit for controlling a freezing operation in which frost or ice is attached thereto. The volume of the drain pan 17 is equal to or greater than the total amount of frost or ice attached to the heat exchanger 16 during the freezing operation. The indoor unit 2 preferably has a capacity of the drain pan 17 (total amount of frost or ice-per unit time in consideration of drain water being drained to the outside of the indoor unit 2 through the drain pipe. It may be configured to be equal to or greater than the amount of drainage of the drain pipe × the time required for thawing all frost or ice or the time required for all frost or ice to fall to the drain pan. [Selection] Figure 2

Description

  The present invention relates to an indoor unit of an air conditioner.

  An indoor unit of an air conditioner sucks indoor air into the interior, passes the sucked indoor air through a heat exchanger, obtains conditioned air that has been subjected to any treatment of heating, cooling, and dehumidification. By blowing out the conditioned air into the room, the room is conditioned.

  The indoor unit of an air conditioner has a filter arranged so as to block between the air intake port that sucks room air and the heat exchanger so that dust contained in the room air does not enter the interior, Collect most of the. However, dust finer than the mesh of the filter enters the interior of the indoor unit through the mesh of the filter.

  Inside the indoor unit, static electricity is generated around the heat exchanger due to friction generated when the sucked room air collides with the heat exchanger. In addition, fine dust that has entered the interior of an indoor unit often contains oil. Therefore, dust that has entered the interior of the indoor unit adheres to the heat exchanger due to static electricity or oil.

  The dust adhering to the heat exchanger contains components that serve as nutrients for germs (including molds). For example, when the air conditioner performs a cooling operation or a dehumidifying operation in summer, moisture in the air condenses on the fins of the heat exchanger, so that the surroundings of the heat exchanger are in a high humidity state. Therefore, if dust continues to adhere to the heat exchanger, various germs (including molds) may grow and a bad odor may be generated. Therefore, it is desired that the air conditioner removes dust adhering to the heat exchanger and keeps the heat exchanger clean throughout the year.

  Therefore, for example, in Patent Document 1, by performing a cooling operation or a dehumidifying operation after the heating operation, water is attached to the surface of the fin of the heat exchanger, and the dust containing the oil component attached to the surface of the fin with the attached water is used. An air conditioner that flushes the air has been proposed. However, the air conditioner described in Patent Document 1 needs to perform antifouling treatment on the fin surface in order to wash off dust with water attached to the fin surface.

  Therefore, for example, an operation of lowering the temperature of the heat exchanger is performed, frost or ice is attached to the surface of the fin, and then an operation of raising the temperature of the heat exchanger is performed to defrost and defrost the frost or ice. It has been studied to remove dust adhering to the heat exchanger using the momentum of falling water. Hereinafter, the process of cleaning the heat exchanger in this way is referred to as “freezing cleaning”. In this freezing and washing, a larger amount of frost (including ice) than the amount of water attached to the fin surface per unit time in a normal cooling operation or dehumidifying operation can be attached to the fin surface. Therefore, with this freezing and cleaning, dust attached to the heat exchanger can be washed away without performing antifouling treatment on the fin surface.

JP 2008-138913 A

  However, in the freezing cleaning, a larger amount of water (drain water) is generated than the amount of water generated per unit time in a normal cooling operation or dehumidifying operation. It is desired that the air conditioner does not leak a large amount of water (drain water) to the outside of the indoor unit.

  The present invention has been made to solve the above-described problems, and has as its main object to provide an indoor unit of an air conditioner that does not leak water to the outside during freeze cleaning.

In order to achieve the above object, the present invention provides a rear heat exchanger that is disposed at the rear of the apparatus and performs heat exchange between the air and the refrigerant, and a heat exchanger that is disposed at the front of the apparatus and between the air and the refrigerant. A pre-heat exchanger for exchanging, a control unit for controlling a freezing operation for attaching frost or ice to the surface of the post-heat exchanger and the front heat exchanger, and drain water dripped from the post-heat exchanger. A rear drain pan, a front drain pan that receives drain water dripping from the front heat exchanger and drain water flowing from the rear drain pan, a communication path that connects the rear drain pan and the front drain pan, and a reservoir in the front drain pan. A drain pipe for draining the drain water from the front drain pan to the outside of the apparatus, and the volume (m ³ ) of all the drain pans including the rear drain pan and the front drain pan is the same as that of the rear heat exchanger. Before Exchanger and the combined all the heat exchanger surface area x (m ^2), and, wastewater from the drainage pipe per unit time (m 3 ^{/ s)} and thawing time required or all of all frost or ice The value z × 10 ⁻⁶ (m ³ ) multiplied by the short time (s) of the time required for the frost or ice to fall to the front drain pan or the rear drain pan, (2.28 × 10 ^{− 6} (m) × x (m ² ) −z × 10 ⁻⁶ (m ³ )) or more.
Other means will be described later.

  According to the present invention, it is possible to prevent water from leaking outside during freeze cleaning.

1 is a configuration diagram of an air conditioner according to Embodiment 1. FIG. It is sectional drawing of the indoor unit of the air conditioner which concerns on Embodiment 1. FIG. It is a perspective view of the drain pan part of the housing | casing used for the indoor unit which concerns on Embodiment 1. FIG. It is the elements on larger scale of the front drain pan in a drain pan part. It is a graph which shows the relationship between the surface area of a heat exchanger, and the amount of drain water which arises by freeze cleaning. It is the schematic which shows the arrangement structure of the drain pipe in a drain pan part. It is the schematic which shows another arrangement structure of the drain pipe in a drain pan part. It is the schematic which shows the inlet_port | entrance structure of the drain pipe in a drain pan part. It is the schematic which shows another inlet_port | entrance structure of the drain pipe in a drain pan part. It is the schematic (1) of the drain pan part of the housing | casing which concerns on a modification. It is the schematic (2) of the drain pan part of the housing | casing which concerns on a modification. It is the schematic (3) of the drain pan part of the housing | casing which concerns on a modification. It is a perspective view of the drain pan part of the housing | casing used for the indoor unit which concerns on Embodiment 2. FIG. It is the elements on larger scale of the front drain pan in a drain pan part. It is a perspective view of the heat insulating material used in Embodiment 2. It is the elements on larger scale (1) of the drainage part of a front drain pan. It is the elements on larger scale (2) of the drainage part of a front drain pan. It is the schematic which shows the arrangement | positioning relationship between a heat exchanger and a front drain pan. It is the schematic (1) of the heat insulating material which concerns on a modification. It is the schematic (2) of the heat insulating material which concerns on a modification. It is the schematic of the drainage part of the front drain pan which concerns on a modification.

  Hereinafter, an embodiment of the present invention (hereinafter referred to as “the present embodiment”) will be described in detail with reference to the drawings. Each figure is only schematically shown so that the present invention can be fully understood. Therefore, the present invention is not limited to the illustrated example. Moreover, in each figure, the same code | symbol is attached | subjected about the common component and the same component, and those overlapping description is abbreviate | omitted.

[Embodiment 1]
<Configuration of air conditioner>
Hereinafter, with reference to FIG.1 and FIG.2, it demonstrates per structure of the air conditioner 1 which concerns on this Embodiment 1. FIG. FIG. 1 is a configuration diagram of an air conditioner 1 according to the first embodiment. FIG. 2 is a cross-sectional view of the indoor unit 2 of the air conditioner 1.

  As shown in FIG. 1, the air conditioner 1 has an indoor unit 2 arranged indoors, an outdoor unit 3 arranged outdoor, and a remote controller 12 arranged near the user's hand in the room. doing.

  The indoor unit 2 sucks indoor air into the interior, passes the sucked indoor air through the heat exchanger 16 (see FIG. 2), and obtains conditioned air subjected to any treatment of heating, cooling, and dehumidification. Then, the conditioned air thus obtained is blown into the room, thereby air-conditioning the room. The indoor unit 2 is connected to the outdoor unit 3 through the connection pipe 5, and the refrigerant is circulated with the outdoor unit 3. The outdoor unit 3 exchanges heat with the circulated refrigerant.

  The indoor unit 2 includes a housing 7 and a decorative frame 8 and includes structures such as a blower fan 14 (see FIG. 2) and a heat exchanger 16 (see FIG. 2). The blower fan 14 is a once-through fan that sends air from the air inlet 6 side to the air outlet 13 side. The heat exchanger 16 is a unit that performs heat exchange with the refrigerant.

  In the example shown in FIG. 1, the front surface of the decorative frame 8 has a shape including an upper part extending in the up-down direction and a lower part extending below in the diagonally backward direction. A front panel 9 is attached to the upper part of the front surface of the decorative frame 8. The front panel 9 is a member that covers the front surface of the indoor unit 2. A receiving unit 10, a display unit 11, and a vertical wind direction plate 18 are attached to the lower part of the front surface of the decorative frame 8.

The receiving unit 10 is a device that receives an operation signal transmitted from the remote controller 12. The receiving unit 10 is electrically connected to a control unit CL built in the indoor unit 2. The controller CL controls the operation of the air conditioner 1 based on the operation signal received from the remote controller 12 via the receiver 10.
The display unit 11 is a device that displays the driving situation.

  The vertical wind direction plate 18 is a member that defines the vertical direction of the conditioned air discharged from the air outlet 13. The vertical wind direction plate 18 is pivotally supported by the decorative frame 8 (or the casing 7) in the vicinity of the lower end so that the upper portion thereof opens and closes in the vertical direction, and is rotated by a drive unit (not shown). ing. The indoor unit 2 forms the air outlet 13 by opening the up-and-down wind direction plate 18.

  As shown in FIG. 2, the indoor unit 2 includes a filter 15, a drain pan 17, and left and right wind direction plates in addition to the blower fan 14, the heat exchanger 16, and the vertical wind direction plate 18 described above. 19.

The filter 15 is a member that prevents dust from entering the inside of the housing 7.
The drain pan 17 is a member that receives water (drain water) that condenses and falls on the surfaces of the fins 20 of the heat exchanger 16.
The left and right wind direction plates 19 are members that define the direction of the conditioned air discharged from the air outlet 13 in the left-right direction.

  The filter 15 is disposed so as to block between the air suction port 6 and the heat exchanger 16. The air conditioner 1 prevents the dust larger than the mesh of the filter 15 from entering the inside of the housing 7 by the filter 15, and further describes dust finer than the mesh of the filter 15 that has passed through the mesh of the filter 15. It is configured to be washed away by freeze washing. The air conditioner 1 is preferably configured to have a filter cleaning mechanism (not shown), and the filter 15 may be automatically (more preferably, periodically) cleaned by the filter cleaning mechanism.

  The blower fan 14 is arranged in the vicinity of the center of the interior of the indoor unit 2 so that air can be sucked from the air inlet 6 and blown out from the air outlet 13. The heat exchanger 16 is arranged on the upstream side of the blower fan 14 (the side close to the air suction port 6), and is formed in a substantially inverted V shape so as to cover the upstream side of the blower fan 14.

  The heat exchanger 16 includes a front heat exchanger 16F and a rear heat exchanger 16R. Each of the front heat exchanger 16F and the rear heat exchanger 16R includes a plurality of fins (heat exchange plates) 20 and a plurality of pipes 40 penetrating the fins 20. The fin 20 is a long thin plate-shaped member for performing heat exchange between the refrigerant and the air. The fin 20 is made of, for example, an aluminum alloy. The pipe 40 is a member for causing the refrigerant to flow.

  In such a configuration, the indoor unit 2 collects most of the dust in the indoor air sucked into the interior by the filter 15. However, some of the dust cannot be collected by the filter 15, enters the interior of the indoor unit 2 through the mesh of the filter 15, and adheres to the heat exchanger 16. If dust continues to adhere to the heat exchanger 16, miscellaneous bacteria (including molds) may grow and a bad odor may be generated. Therefore, the air conditioner 1 is preferably configured to remove dust attached to the heat exchanger 16. Therefore, in the present embodiment, the air conditioner 1 performs the following cleaning process on the heat exchanger 16 by operation control.

  That is, first, the air conditioner 1 performs an operation of lowering the temperature of the heat exchanger 16 to rapidly cool the heat exchanger 16 and attach frost or ice to the surface of the fin 20 of the heat exchanger 16. (Hereinafter referred to as “freezing operation”). In the present embodiment, the operation for performing the freezing operation is referred to as “freezing operation”.

  In the freezing operation, frost (including ice) is considered to adhere directly to the surface of the fin 20 of the heat exchanger 16 without passing through water droplets due to sublimation of moisture in the air. However, frost (ice) is caused by moisture in the air condensing on the surfaces of the fins 20 of the heat exchanger 16, and the condensed moisture freezes to form water droplets. It may adhere to the surface.

  In the freezing operation, unlike the normal cooling operation, the air conditioner 1 does not operate the blower fan 14. Thereby, the air conditioner 1 suppresses the fall (water dripping) of the water (condensation water) condensed on the surface of the fin 20 of the heat exchanger 16, and the water (condensation water) stays on the surface of the fin 20. The time can be lengthened. As a result, the air conditioner 1 can ensure a stable amount of water frozen.

  After the freezing operation, the air conditioner 1 performs an operation for raising the temperature of the heat exchanger 16 and rapidly heats the heat exchanger 16 to thaw (melt) frost (ice) (hereinafter, “thawing”). Operation). In the present embodiment, the operation for performing the thawing operation is referred to as “thawing operation”. The air conditioner 1 returns frost (ice) to water by performing a thawing operation. At that time, the air conditioner 1 uses the momentum at which the thawed (melted) water falls to wash away the fine dust adhering to the heat exchanger 16. Thereby, the air conditioner 1 can improve the maintainability of the heat exchanger 16, and can wash | clean the heat exchanger 16 efficiently. Hereinafter, this cleaning process (a cleaning process performed by a freezing operation and a thawing operation) is referred to as “freezing cleaning”.

  In addition, the air conditioner 1 receives the water (drain water) that flows out during the thawing operation by the drain pan 17. The drain pan 17 is formed with a flow path for flowing water (drain water). The inner wall surface of the flow path is mirror-finished to facilitate the flow of water (drain water). A drain pipe is connected to the flow path. The air conditioner 1 drains water (drain water) flowing out through the drain pipe to the outside of the housing 7.

<Drain pan configuration>
Hereinafter, the configuration of the drain pan 17 will be described with reference to FIGS. 3 to 6. In the present embodiment, the drain pan 17 is described as being integrally formed with the housing 7. FIG. 3 is a perspective view of a drain pan portion of the housing 7. FIG. 4 is a partially enlarged view of the front drain pan 17F in the drain pan portion. FIG. 5 is a graph showing the relationship between the surface area of the heat exchanger 16 and the amount of drain water generated by freeze cleaning. FIG. 6 is a schematic view showing an arrangement structure of the drain pipe 22 in the drain pan portion.

  As shown in FIG. 3, the drain pan 17 includes a rear drain pan 17R disposed below the rear heat exchanger 16R (see FIG. 2) and a front drain pan disposed below the front heat exchanger 16F (see FIG. 2). 17F. In the present embodiment, communication passages 21a and 21b are provided on both sides of the rear drain pan 17R. Further, drain pipes 22a and 22b are provided on both sides of the front drain pan 17F. Hereinafter, the communication paths 21a and 21b are collectively referred to as “communication path 21”. Further, when the drain pipes 22a and 22b are generically referred to as “drain pipe 22”.

  The rear drain pan 17R receives water dripped from the rear heat exchanger 16R (see FIG. 2). The bottom surface of the rear drain pan 16R is inclined downward toward the side closer to the communication path 21 from the far side. In the present embodiment, the bottom surface of the rear drain pan 16R is high near the substantially center in the left-right direction, and the left end and the right end are lower than that. Thereby, the water dripped from the rear heat exchanger 16R (see FIG. 2) flows out from the rear drain pan 16R to the communication passage 21.

  The bottom surface of the communication path 21 is inclined downward from the rear drain pan 16R side toward the front drain pan 16F side. Thereby, the water dripped from the rear heat exchanger 16R (see FIG. 2) flows out from the communication passage 21 to the front drain pan 17F.

  As shown in FIG. 4, the front drain pan 17 </ b> F communicates with the drain pipe 22. In the present embodiment, the drain pipe 22 is formed as a circular pipe integral with the housing 7, and has a structure in which the inlet 23 is opened inside the front drain pan 17 </ b> F.

  The front drain pan 17F receives water dripped from the front heat exchanger 16F (see FIG. 2). Further, water dripped from the rear heat exchanger 16R (see FIG. 2) flows into the front drain pan 17F from the rear drain pan 16R side. The water dropped from the front heat exchanger 16F (see FIG. 2) and the water dropped from the rear heat exchanger 16R (see FIG. 2) are drained to the outside of the indoor unit 2 through the drain pipe 22. Hereinafter, the water dripped from the front heat exchanger 16F (see FIG. 2) and the water dripped from the rear heat exchanger 16R (see FIG. 2) are collectively referred to as “drain water”.

<Volume of drain pan>
In the indoor unit 2, during the freezing operation, a large amount of frost (ice) larger than the amount of water adhering to the rear heat exchanger 16R and the front heat exchanger 16F per unit time in the normal cooling operation or dehumidifying operation is It adheres to the exchanger 16R and the pre-heat exchanger 16F. During the thawing operation, frost (ice) adhering to the rear heat exchanger 16R and the front heat exchanger 16F is thawed all at once. As a result, a larger amount of drain water than the amount of water generated per unit time during normal cooling operation or dehumidifying operation is generated during freezing washing, and dripped onto the rear drain pan 17R and the front drain pan 17F all at once.

  Therefore, if the rear drain pan 17R and the front drain pan 17F do not have a volume capable of storing a large amount of drain water generated during the thawing operation, the drain water passes through the drain pipes 22a and 22b and flows into the indoor unit 2. Until it is drained to the outside, it overflows from the front drain pan 17F or the rear drain pan 17R. As a result, the drain water leaks out of the indoor unit 2. Therefore, it is desirable for the air conditioner 1 not to leak a large amount of drain water generated during the thawing operation to the outside of the indoor unit 2. Therefore, it is desirable that the drain pan 17 has a volume that does not overflow a large amount of drain water generated during the thawing operation.

  Therefore, in the present embodiment, in the indoor unit 2, the volume of all the drain pans 17 including the rear drain pan 17R and the front drain pan 17F exceeds the total amount of frost or ice attached to the heat exchanger 16 during the freezing operation. It is configured as such. However, when it is considered that drain water is drained to the outside of the indoor unit 2 through the drain pipe 22, the indoor unit 2 has a total amount of frost or ice attached to the heat exchanger 16 during the freezing operation. On the other hand, the volume of the drain pan 17 is (total amount of frost or ice attached−the amount of drainage of the drain pipe 22 per unit time × the time required to thaw all the frost or ice, or until all the frost or ice falls on the drain pan 17. It is good to be configured so as to be more than a short time). This point will be described in detail below.

Here, FIG. 5 shows the relationship between the surface area of all the heat exchangers 16 including the rear heat exchanger 16R and the front heat exchanger 16F and the amount of drain water (the total amount of frost or ice) generated during freeze washing. Show. FIG. 5 shows experimental results measured when the air conditioner 1 is subjected to freeze cleaning under conditions of an indoor temperature of 27 ° C. and an indoor humidity of 35%. As shown in FIG. 5, according to the experiment, for example, when the surface area of all the heat exchangers 16 including the rear heat exchanger 16R and the front heat exchanger 16F is 15 ( m ² ) , 34. 2 ( ml ) = 34.2 × 10 ⁻⁶ (m ³ ) of drain water is generated. That is, when the drain water amount (frost or ice total adhesion amount) generated during the thawing operation is w (m ³ ) and the surface area of the heat exchanger 16 is x (m ² ) , the drain water amount w (m ³ ). Is in a relationship of (w = 2.28 (m) × 10 ⁻⁶ × x (m ² ) ) with respect to the surface area x (m ² ) of the heat exchanger 16. The coefficient 2.28 has a dimension of length (here, m (meter)), so that the dimension of w becomes the volume (m ³ ).

In addition, even if the surface area x (m ² ) of the heat exchanger 16 is the same and the freezing time is the same when the freezing cleaning is performed in an environment where the indoor humidity is lower than that in the experiment of FIG. The amount of drain water generated after frost (ice) thaws decreases. Further, when freezing washing is performed in an environment where the indoor humidity is higher than in the experiment of FIG. 5, the drain water generated after the frost (ice) is thawed can be adjusted by adjusting the freezing time. . Therefore, in the indoor unit 2, the volume y ₀ (m ³ ) of all the drain pans 17 including the rear drain pan 17R and the front drain pan 17F is equal to or greater than w (m ³ ) , that is, (y ₀ = 2.28 × 10 ^{− If it is 6} × x) (m ³ ) or more, it is possible to prevent the drain water generated by freeze washing from leaking to the outside. Therefore, the volume y ₀ (m ³ ) of the drain pan 17 is preferably 2.28 (m) × 10 ⁻⁶ × x (m ² ) or more.

However, the above-described value y ₀ (m ³ ) is the volume of the drain pan 17 when the drain water draining treatment from the front drain pan 17F to the outside of the outdoor unit 2 by the drain pipe 22 is not considered. In contrast, the indoor unit 2 performs drain water drainage processing from the front drain pan 17F through the drain pipe 22 to the outside of the outdoor unit 2 in parallel with the frost (ice) thawing process.

Therefore, when considering the drain water drainage treatment, the indoor unit 2 uses the drainage amount of drain water drained by the drainage treatment from the above-described value y ₀ (m ³ ) (for example, z × 10 ⁻⁶ (m ³ )). ) The value y ₁ (m ³ ) obtained by subtracting by the amount can be set as the volume of the drain pan 17. That is, when considering drain water drainage treatment, the indoor unit 2 has a volume y ₁ (m ³ ) of all drain pans 17 including the rear drain pan 17R and the front drain pan 17F (wz × 10 ^−6). ) ( M ³ ) or more, that is, (y ₁ = 2.28 × 10 ⁻⁶ × x−z × 10 ⁻⁶ = (2.28x−z) × 10 ⁻⁶ ) (m ³ ) or more, It is possible to prevent drain water generated by freezing and washing from leaking outside. Therefore, the volume y ₁ (m ³ ) of the drain pan 17 in consideration of drain water drainage treatment is preferably ( 2.28x−z ) × 10 ⁻⁶ (m ³ ) or more.

Of the values ( 2.28x−z ) × 10 ^{−6 described} above, the value 2.28x × 10 ⁻⁶ corresponds to the “total amount of frost or ice (m ³ )”. Further, the value z × 10 ⁻⁶ is “the amount of drainage of the drain pipe 22 per unit time (m ³ / s) × the time required to thaw all the frost or ice or until all the frost or ice falls on the drain pan 17. This corresponds to a short time (s) among the time required for. Therefore, in other words, the indoor unit 2 has a volume y ₁ (m ³ ) of the drain pan 17 in consideration of drain water drainage treatment, (total amount of frost or ice (m ³ ) −drainage per unit time). If the amount of drainage of the tube 22 (m ³ / s) × the time required for thawing all frost or ice or the time required for all the frost or ice to fall into the drain pan 17 is a short time (s)) or more, It is possible to prevent drain water generated by freezing and washing from leaking outside.

Whether the above-described value y ₀ (m ³ ) or the above-described value y ₁ (m ³ ) is applied as the volume of the drain pan 17 can be selected according to the operation. When the above-described value y ₀ (m ³ ) is applied as the volume of the drain pan 17, the volume of the drain pan 17 increases, so that the drain water overflows from the drain pan 17 instead of increasing the size of the indoor unit 2. On the other hand, a large margin can be set. On the other hand, when the above-described value y ₁ (m ³ ) is applied as the volume of the drain pan 17, the volume of the drain pan 17 can be reduced, so that the indoor unit 2 can be downsized.

  The indoor unit 2 is not only provided with a volume in the drain pan 17 that does not overflow a large amount of drain water generated during the thawing operation, but also drains all the drain water from the front drain pan 17F without overflowing the drain water. It is good to make it the structure which can drain easily with the drain pipe 22 to the exterior of the machine 2. FIG. Here, “all drain water” means water that is a combination of drain water dropped from the post heat exchanger 16R and drain water dropped from the front heat exchanger 16F.

  Therefore, in the present embodiment, the indoor unit 2 is configured so that the inner diameter R (see FIG. 6) of the drain pipe 22 and the depth h (see FIG. 6) of the front drain pan 17F satisfy the relationship of Expression (9) described later. It shall be. This point will be described in detail below.

Here, the flow rate of the drain water flowing through the drain pipe 22 per unit time is the product of the cross-sectional area inside the drain pipe 22 that is a circular pipe and the drain water discharge speed. Therefore, the flow rate of drain water flowing through the drain pipe 22 per unit time is “Q” (m ³ / s), the inner diameter of the drain pipe 22 is “R” (m), and the radius is “r” (m). (That is, “R = 2r”) and the flow rate of drain water flowing through the drain pipe 22 per unit time is “Q” where the outflow speed of the drain water flowing through the drain pipe 22 is “v” ( m / s ). (M ³ / s) is represented by the following equation (1).

Also, assuming that the depth of the front drain pan 17F is “h” (m) and the gravitational acceleration is “g” (m / s ² ), from the “Trichelli's theorem”, the outflow rate “ “v” ( m / s ) is represented by the following equation (2). The “Trichelli's theorem” is a theorem concerning the flow rate of the liquid when a relatively small hole is made in the side surface of the container containing the liquid. Further, the depth “h” of the front drain pan 17F is a value from the upper limit surface where the drain water does not overflow to the bottom surface BS1 of the front drain pan 17F.

By substituting the above equation (2) into the above equation (1), the following equation (3) is obtained.

Here, the flow rate “Q” (m ³ / s) of drain water flowing through the drain pipe 22 per unit time is the amount of drain water generated during the thawing operation per hour (3600 seconds) (total amount of frost or ice attached) ) The flow rate of flowing “w” (m ³ ) . The drain water amount (total amount of frost or ice) “w” corresponds to the volume y ₀ (m ³ ) required for the drain pan 17. Therefore, the flow rate “Q” (m ³ / s) of the drain water flowing through the drain pipe 22 per unit time is represented by the following equation (4).

By substituting the above equation (4) into the above equation (3), the following equation (5) is obtained.

From the above equation (5), the following equation (6) is obtained.

From the above equation (6), the following equation (7) is further obtained.

Since the inner diameter “R” of the drain pipe 22 is “R = 2r”, the following equation (8) is further obtained from the above equation (7).

The drain pipe 22 makes all the drain water to the outside of the indoor unit 2 without overflowing the drain water from the front drain pan 17F by making the inner diameter “R” larger than that of the relationship of the above-described formula (8). The drainage pipe 22 can be easily drained. Therefore, by setting the inner diameter R (see FIG. 6) of the drain pipe 22 and the depth h (see FIG. 6) of the front drain pan 17F to satisfy the relationship of the following equation (9), the drain pipe 22 All drain water can be easily drained out of the indoor unit 2 through the drain pipe 22 without overflowing drain water from the drain pan 17F.

Y ₀ (m ³ ) is the volume of all the drain pans 17 including the rear drain pan 17R and the front drain pan 17F, and all the heat exchangers including the rear heat exchanger 16R and the front heat exchanger 16F. The relationship is (y ₀ = 2.28 × 10 ⁻⁶ × x) with respect to 16 surface areas x (m ² ) . The inner diameter R of the drain pipe 22 is preferably, for example, 11 ( mm ) or more.

  The indoor unit 2 is configured such that the inner diameter R of the drain pipe 22 and the depth h of the front drain pan 17F satisfy the relationship of the above-described formula (9). Such an indoor unit 2 can drain the drain water to the outside of the indoor unit 2 before the drain water overflows from the front drain pan 17F. Moreover, the indoor unit 2 can drain a large amount of drain water generated by freezing and washing without unnecessarily increasing the size of the housing 7.

  In addition, as shown in FIG. 6, the drain pipe 22 is good to arrange | position so that the center axis | shaft C22 may incline below toward the exit 24 from the inlet_port | entrance 23. FIG. Thereby, the indoor unit 2 can smoothly drain the drain water accumulated in the front drain pan 17F to the outside.

  In addition, at the time of freezing washing, the dust adhering to the front heat exchanger 16F and the rear heat exchanger 16R flows together with the drain water. Therefore, in the vicinity of the inlet 23 of the drain pipe 22, the drain water and dust are mixed and become sludge and easily collect. As a result, sludge-like drain water and dust may flow into the drain pipe 22.

  However, the indoor unit 2 makes it easy to drop the drain water and dust flowing into the drain pipe 22 by its own weight by arranging the drain pipe 22 at an inclination. Therefore, even if the drain water and dust that have become sludge flow into the drain pipe 22, the indoor unit 2 can send them out to the outside satisfactorily. Such an indoor unit 2 can maintain the inside of the drain pipe 22 in a state suitable for drain water drainage. Moreover, the indoor unit 2 can also suppress itself that drain water and dust accumulate in the vicinity of the inlet 23 of the drain pipe 22. As a result, the indoor unit 2 can improve the drainage efficiency of the drain water accumulated in the front drain pan 17F.

  Further, the bottom surface BS1 of the front drain pan 17F may be modified as shown in FIG. 7, for example. FIG. 7 is a schematic view showing another arrangement structure of the drain pipe 22. As shown in FIG. 7, the front drain pan 17 </ b> F has a structure in which the bottom surface BS <b> 2 in the vicinity of the inlet 23 of the drainage pipe 22 is inclined downward from the side far from the inlet 23 of the drainage pipe 22 toward the near side. That is, the front drain pan 17F has a shape in which a recess is formed on the bottom surface near the outlet of the flow path. The inclination angle α22 of the central axis C22 of the drainage pipe 22 is greater than or equal to the inclination angle α17 of the bottom surface BS1 of the front drain pan 17F in the vicinity of the inlet 23 of the drainage pipe 22. Such an indoor unit 2 makes it easy for drain water including dust collected in the front drain pan 17F to flow in the direction of the drain pipe 22 by its own weight. Therefore, the indoor unit 2 can drain the drain water collected in the front drain pan 17F more smoothly than the configuration shown in FIG. As a result, the indoor unit 2 can improve the drainage efficiency of the drain water accumulated in the front drain pan 17F.

  For example, the inlet 23 of the drain pipe 22 may be modified as shown in FIG. FIG. 8 is a schematic view showing the inlet structure of the drain pipe 22. FIG. 9 is a schematic view showing another inlet structure of the drain pipe 22.

  In the example shown in FIG. 8, the inlet 23 of the drain pipe 22 has a shape in which the lower half circumference extends forward of the inlet 23 of the drain pipe 22. Thus, the indoor unit 2 is configured such that the opening area S23 of the inlet 23 of the drain pipe 22 is larger than the cross-sectional area S22M near the center of the drain pipe 22.

  In the example shown in FIG. 9, the inlet 123 of the drain pipe 22 is formed in an upward elliptical shape. Accordingly, the indoor unit 2 is configured such that the opening area S123 of the inlet 123 of the drain pipe 22 is larger than the cross-sectional area S22M near the center of the drain pipe 22.

  In the configuration shown in FIG. 8 or FIG. 9, the drain pipe 22 can efficiently take in drain water collected in the front drain pan 17F and drain it to the outside. Thereby, the indoor unit 2 can efficiently take in drain water containing dust into the drain pipe 22. For this reason, even if the indoor unit 2 may be mixed with drain water and dust in the vicinity of the inlet 23 of the drain pipe 22 to become a sludge and difficult to drain, it takes these into the drain pipe 22. It can be sent out well. Thereby, the indoor unit 2 can also suppress itself that drain water and dust accumulate in the vicinity of the inlet 23 of the drain pipe 22. As a result, the indoor unit 2 can improve the drainage efficiency of the drain water accumulated in the front drain pan 17F.

<Modification of the drain pan portion of the housing>
The drain pan portion of the housing 7 may be modified as, for example, the housings 7A, 7B, and 7C illustrated in FIGS. 10A to 10C. 10A to 10C are schematic views showing modifications of the drain pan portion of the housing 7 respectively.

  In the example shown in FIG. 10A, the housing 7A has a shape in which the rear drain pan 17R is extended in the left-right direction as compared with the housing 7 shown in FIG. 3, and the communication portions 21a and 21b are rear drain pans. It is different in that it is arranged at a position on the near side of 17R. Accordingly, in the housing 7A, the communication passages 21a and 21b are arranged at positions in the vicinity of the left and right sides of the rear drain pan 17R. The communication passages 21a and 21b are formed such that their bottom surfaces are inclined downward from the rear drain pan 17R side toward the front drain pan 17F side.

  In the example shown in FIG. 10B, the housing 7B is different from the housing 7 shown in FIG. 3 in that the communication path 21 is arranged only at the left and right side positions of the rear drain pan 17R. Further, the rear drain pan 17R is formed so that the bottom surface thereof is inclined downward from the side far from the communication path 21 toward the side close thereto.

  In the example shown in FIG. 10C, the housing 7A has a shape in which the rear drain pan 17R is extended in the left-right direction as compared with the housing 7B shown in FIG. 10B, and the communication path 21 is the rear drain pan 17R. It is different in that it is arranged at the front side position.

  Like the casings 7A, 7B, and 7C shown in FIGS. 10A to 10C, the communication passage 21 is not disposed on both sides of the front drain pan 17F and the rear drain pan 17R, but the positions near the left and right sides of the rear drain pan 17R, The rear drain pan 17R can be arranged at one of the left and right sides or a position near one side. Thereby, the communicating path 21 can connect the front drain pan 17F and the rear drain pan 17R. The bottom surface of the rear drain pan 17R is configured such that the side closer to the communication passages 21a and 21b is slightly lower than the side far from the communication passages 21a and 21b. Such casings 7A, 7B, and 7C shown in FIGS. 10A to 10C improve the degree of freedom of the arrangement structure of the communication passage 21, and drain the drain water dripped from the rear heat exchanger 16R to the rear drain pan 17R. Can be improved.

  The indoor unit 2 can suppress the accumulation of drain water and dust near the inlet 23 of the drain pipe 22 by appropriately combining the structures shown in FIGS. 6 to 10C. As a result, the indoor unit 2 can improve the drainage efficiency of the drain water accumulated in the front drain pan 17F.

<Main features of indoor unit>
(1) In the indoor unit 2 according to this embodiment, the volume of the drain pan 17 is greater than or equal to the total amount w of frost or ice attached to the heat exchanger 16 during the freezing operation. The indoor unit 2 is preferably configured so that the drain pan 17 has a volume (total amount of frost or ice-unit time per unit time) in consideration of drain water being drained to the outside of the indoor unit 2 through the drain pipe 22. Even if it is configured to be equal to or longer than the amount of time required for thawing all frost or ice or the time required for all frost or ice to fall on the drain pan 17) Good. In this case, the volume (m ³ ) of all the drain pans 17 including the rear drain pan 17R and the front drain pan 17F is equal to all the heat exchangers 16 including the rear heat exchanger 16R and the front heat exchanger 16F. Surface area x (m ² ), and the amount of drainage from the drain pipe per unit time (m ³ / s) and the time required to thaw all frost or ice, or all frost or ice For the value z × 10 ⁻⁶ (m ³ ) multiplied by the short time (s) of the time required to fall on the drain pan, (2.28 × 10 ⁻⁶ (m) × x (m ² ) − z × 10 ⁻⁶ (m ³ )) = (2.28x−z) × 10 ⁻⁶ (m ³ ) or more is preferable.

  In such an indoor unit 2, the drain pan 17 has a volume that does not overflow a large amount of drain water generated during the thawing operation. Therefore, the indoor unit 2 can prevent drain water from leaking to the outside during freeze cleaning.

(2) The communication path 21 is disposed at the left and right sides of the rear drain pan 17R or at positions near both sides, and the bottom surface thereof is inclined downward from the rear drain pan 17R side toward the front drain pan 17F side. (See FIG. 3 or FIG. 10A).
Alternatively, the communication path 21 is disposed at the left or right side of the rear drain pan 17R or at a position near one side, and the bottom surface thereof is inclined downward from the rear drain pan 17R toward the front drain pan 17F. It can be configured (see FIG. 10B or FIG. 10C). In the case of this configuration, the bottom surface of the rear drain pan 17R may be configured to incline downward from the side far from the communication path 21 toward the side close thereto.

  Such an indoor unit 2 can improve the degree of freedom of the arrangement structure of the communication passage 21 and can improve drainage of drain water dripped from the rear heat exchanger 16R to the rear drain pan 17R.

(3) When the gravitational acceleration is g (m / s ² ) , the inner diameter of the drain pipe 22 with respect to the volume y ₀ (m ³ ) of all the drain pans 17 including the rear drain pan 17R and the front drain pan 17F. R and the depth h (m) of the front drain pan 17F may satisfy the relationship of the following formula (10).

  Such an indoor unit 2 can drain the drain water to the outside of the indoor unit 2 before the drain water overflows from the front drain pan 17F. Moreover, the indoor unit 2 can drain a large amount of drain water generated by freezing and washing without unnecessarily increasing the size of the housing 7.

  (4) The bottom surface of the front drain pan 17F is inclined at least in the vicinity of the inlet 23 of the drainage pipe 22 from the side far from the inlet 23 of the drainage pipe 22 toward the side closer to the inlet 23 (see FIG. 7).

  In such an indoor unit 2, it is assumed that drain water and dust are mixed in the vicinity of the inlet 23 of the drain pipe 22 to become a sludge shape, and the sludge-shaped drain water and dust are contained in the drain pipe 22. Even if they flow in, they can be sent out to the outside. Such an indoor unit 2 can maintain the inside of the drain pipe 22 in a state suitable for drain water drainage. Moreover, the indoor unit 2 can also suppress itself that drain water and dust accumulate in the vicinity of the inlet 23 of the drain pipe 22. As a result, the indoor unit 2 can improve the drainage efficiency of the drain water accumulated in the front drain pan 17F.

  (5) The drain pipe 22 is disposed such that the central axis C22 is inclined downward from the inlet 23 toward the outlet 24. The inclination angle α22 of the central axis C of the drain pipe 22 is equal to or greater than the inclination angle α17 of the bottom surface BS2 of the front drain pan 17F in the vicinity of the inlet 23 of the drain pipe 22 (see FIG. 7).

  Such an indoor unit 2 makes it easy for drain water including dust collected in the front drain pan 17F to flow in the direction of the drain pipe 22 by its own weight. Therefore, the indoor unit 2 can smoothly drain the drain water accumulated in the front drain pan 17F. As a result, the indoor unit 2 can improve the drainage efficiency of the drain water accumulated in the front drain pan 17F.

  (6) The indoor unit 2 can be configured such that the opening area S23 of the inlet 23 of the drain pipe 22 (or the opening area S123 of the inlet 123) is larger than the cross-sectional area S23M near the center of the drain pipe 22. (See FIGS. 8 and 9).

  Such an indoor unit 2 can efficiently take in drain water containing dust collected in the front drain pan 17F through the drain pipe 22 and drain it to the outside. Thereby, the indoor unit 2 can efficiently take in drain water containing dust into the drain pipe 22. For this reason, the indoor unit 2 takes the drain water and dust in the vicinity of the inlet 23 of the drain pipe 22 even if they become mixed and become difficult to be drained. Can be sent to the outside well. Thereby, the indoor unit 2 can also suppress itself that drain water and dust accumulate in the vicinity of the inlet 23 of the drain pipe 22. As a result, the indoor unit 2 can improve the drainage efficiency of the drain water accumulated in the front drain pan 17F.

  As described above, according to the indoor unit 2 of the air conditioner 1 according to Embodiment 1, it is possible to prevent water from leaking to the outside during freeze cleaning.

[Embodiment 2]
In the second embodiment, an indoor unit 2A in which the following points are taken into consideration is provided.
(1) If drain water or dust remains inside the drain pan 17, there is a concern that water overflow or miscellaneous bacteria (including mold) may occur during the next freezing and washing. . Therefore, the indoor unit 2A reduces the surface tension (binding force) of the drain water by providing an uneven portion 130 (see FIG. 11 and FIG. 12) to be described later in the drain pan 17 so that the drain water can easily flow. Accordingly, the indoor unit 2A facilitates the flow of dust together with the drain water, and reduces the amount of dust remaining in the drain pan 17. However, the concave and convex portion 130 (see FIG. 12) to be described later is not provided at a position immediately before the inlet 23 (see FIG. 12) of the drain pipe 22, so that dust is accumulated near the inlet 23 of the drain pipe 22. Suppress.

  (2) When cold drain water flows into the drain pan 17 during freezing and washing, moisture in the air may condense and adhere to each part of the drain pan 17 (for example, the lower surface side of the front drain pan 17F) as condensed water. There is. For example, when the dew condensation water adheres to the lower surface side of the front drain pan 17F, the dew condensation water may sag into the air outlet 13 (see FIG. 2) and be scattered in the room. Thereby, dew condensation water will leak out of the indoor unit 2A. Therefore, the indoor unit 2A is provided with a heat insulating material (foamed resin material) 111 (see FIGS. 11 and 12) and the like which will be described later in each part of the drain pan 17 in order to suppress the occurrence of condensation. However, in the indoor unit 2A, the arrangement position and shape of a heat insulating material (foamed resin material) 111, which will be described later, are taken into consideration so as not to lower the drain water drain rate during drainage and to reduce drainage efficiency. The configuration.

  (3) The casing 7 constituting the drain pan 17 is difficult to process. Therefore, when the indoor unit 2A is provided with an uneven portion 130 (see FIGS. 11 and 12) to be described later in the drain pan 17, the uneven portion to be described later using a different member from the casing 7 constituting the drain pan 17. 130 is provided. That is, the indoor unit 2 </ b> A arranges a heat insulating material (foamed resin material) 111 (see FIG. 11 and FIG. 12) and the like on which an uneven portion 130 to be described later is formed on the upper surface inside the lens pan 17. The uneven | corrugated | grooved part 130 mentioned later inside is provided.

  (4) If a gap is formed between the heat exchanger 16 and the drain pan 17, an air passage that does not pass through the heat exchanger 16 is formed, so that the heat exchange efficiency of the indoor unit 2A is improved. descend. In addition, the gap may cause dripping (water leakage to the outside of the indoor unit 2A). Therefore, the indoor unit 2A is configured such that the heat exchanger 16 and the drain pan 17 are in close contact with each other, and no gap is formed between the heat exchanger 16 and the drain pan 17 (see FIG. 16).

  Hereinafter, the configuration of the indoor unit 2A according to the second embodiment will be described with reference to FIGS. 11 to 16. FIG. 11 is a perspective view of a drain pan portion of the housing 107 used for the indoor unit 2A. FIG. 12 is a partially enlarged view of the front drain pan 17F in the drain pan portion. FIG. 12 is an enlarged view of the configuration near the portion A in FIG. FIG. 13 is a perspective view of a heat insulating material (foamed resin material) 111 used in the second embodiment. 14 and 15 are partially enlarged views of the drainage part 120 of the front drain pan 17F, respectively. FIG. 14 shows the configuration of the drainage section 120 cut along the line BB in FIG. FIG. 15 shows a configuration in the vicinity of the inlet 23 of the drain pipe 22 in the drain section 120 cut along the line CC in FIG. FIG. 16 is a schematic diagram showing the positional relationship between the heat exchanger 16F and the front drain pan 17F.

The indoor unit 2A according to the second embodiment is different from the indoor unit 2 according to the first embodiment (see FIG. 2) in the following points.
(1) The heat insulating material 111 in which the convex part 112 was formed in the front side of the saucer part 110 of the front drain pan 17F is attached (refer FIG.11 and FIG.12). The saucer part 110 is a channel part extending in the left-right direction of the front drain pan 17F.
(2) The convex part 122 is formed in the drainage part 120 of the front drain pan 17F (refer FIG.11 and FIG.12). The drainage part 120 is a flow path part extending in the front-rear direction (front and back directions) of the front drain pan 17F.
(3) The heat insulating material 161 in which the convex part 162 was formed is attached to the saucer part 160 of the back drain pan 17R (refer FIG. 11). The saucer portion 160 is a channel portion extending in the left-right direction of the rear drain pan 17R.
(4) The convex part 172 is provided in the communicating path 21 (refer FIG. 11).
(5) The heat insulating material 211 is attached to the back side of the drain part 120 of the front drain pan 17F in the vicinity of the inlet 23 of the drain pipe 22 (see FIG. 15).

  In the heat insulating material 111 (see FIGS. 11 and 12), the heat insulating material 161 (see FIG. 11), and the heat insulating material 211 (see FIG. 15), cold drain water flows into the drain pan 17 at the time of freeze cleaning. Thus, these are members attached to the housing 107A of the indoor unit 2A in order to prevent moisture in the air from condensing on each part of the drain pan 17. The indoor unit 2 </ b> A can suppress the moisture in the air from condensing and adhering to the drain pan 17 as condensed water by disposing the heat insulating materials 111, 161, and 211 in each part of the drain pan 17.

  These heat insulating materials 111, 161, and 211 are made of, for example, a foamed resin material having low hygroscopicity such as foamed polystyrene or foamed urethane. In particular, since the heat insulating materials 111 and 161 in which the flow path for drain water is formed are made of a material having low hygroscopicity, the surface thereof has water repellency. Since such a heat insulating material 111,161 does not contain water, generation | occurrence | production of mold | fungi can be suppressed. Moreover, the heat insulating materials 111 and 161 can make it easy to evaporate drain water flowing into the flow path portion. Therefore, the heat insulating materials 111 and 161 can contribute to the downsizing of the drain pan 17. In addition, it is good for the flow-path part of the heat insulating materials 111 and 161 to perform the mirror surface process for making it easy to flow drain water.

  FIG. 13 shows an example of the heat insulating material 111. The heat insulating material 111 is configured to be attachable to the drainage portion 120 extending in the front-rear direction (front and back directions) inside the front drain pan 17F. As shown in FIG. 13, a convex portion 112 is formed on the upper surface of the heat insulating material 111. The convex 112 is formed so as to extend along the direction in which drain water flows (the direction in which the flow path extends). The convex portion 112 functions as the concave-convex portion 130 that reduces the surface tension (binding force) of the drain water. The indoor unit 2A reduces the surface tension (bonding force) of the drain water by the convex portion 112 of the heat insulating material 111, so that the water droplets of the drain water do not have to wait to grow into large size water droplets. It is possible to facilitate the flow of drain water in the state of small sized water droplets. Accordingly, the indoor unit 2A facilitates the flow of dust together with the drain water, and reduces the amount of dust remaining in the drain pan 17.

  The heat insulating material 161 (see FIG. 11) has the same shape as the heat insulating material 111. The heat insulating material 161 is configured to be attached to the inside of the rear drain pan 17R. A convex portion 162 similar to the convex portion 112 is formed on the upper surface of the heat insulating material 161. The convex part 162 is formed so as to extend along the direction in which drain water flows (direction in which the flow path extends).

  The heat insulating material 211 (see FIG. 15) is configured to be attached to a space formed below the drainage portion 120 of the front drain pan 17F near the inlet 23 of the drainage pipe 22.

  A convex portion 122 is formed in the drainage portion 120 of the front drain pan 17F (see FIGS. 11 and 12). The convex portion 122 is formed so as to extend along the direction in which drain water flows (direction in which the flow path extends). In this embodiment, the upper surface of the convex part 122 is formed in a substantially flat surface shape (see FIG. 14). Similar to the convex portion 112, the convex portion 122 functions as the concave and convex portion 130 that reduces the surface tension (binding force) of the drain water.

  The convex part 122 is formed so as to exclude the position immediately before the inlet 23 of the drain pipe 22 (see FIG. 12). Accordingly, the indoor unit 2A suppresses accumulation of dust near the inlet 23 of the drain pipe 22.

  In the present embodiment, the convex portion 122 is directly formed on the housing 107 constituting the front drain pan 17F. However, in the indoor unit 2A, the convex portion 122 is formed in advance on a separate member (not shown) different from the housing 107, and the separate member is attached to the drainage portion 120, whereby the convex portion 122 is removed from the drainage portion 120. You may make it arrange | position to.

  In addition, the bottom face of the drainage part 122 of the front drain pan 17F has a shape inclined downward toward the inlet 23 side of the drainage pipe 22 (see FIG. 12). That is, the drainage part 122 of the front drain pan 17F has a shape in which a recess is formed on the bottom surface near the outlet of the flow path. As a result, the indoor unit 2A facilitates the flow of drain water in the direction of the inlet 23 of the drain pipe 22.

  The communication path 21 is provided with a convex portion 172 (see FIG. 11). The convex portion 172 is formed so as to extend along the direction in which drain water flows (direction in which the flow path extends). In the present embodiment, the convex portion 172 is directly formed on the housing 107 that constitutes the front drain pan 17F.

  As shown in FIG. 16, in the present embodiment, the heat exchanger 16 (the front heat exchanger 16F in the illustrated example) and the drain pan 17 (the front drain pan 17F in the illustrated example) are arranged so as to contact each other. As a result, the space between the space where the blower fan 14 (see FIG. 2) is disposed and the space outside the space is closed. As a result, the indoor unit 2A is configured such that the heat exchanger 16 (the front heat exchanger 16F in the illustrated example) and the drain pan 17 (the front drain pan 17F in the illustrated example) are in close contact with each other, so that the heat exchanger 16 and the drain pan 17 are in close contact with each other. No gap is formed between them. In such an indoor unit 2A, a gap is formed between the heat exchanger 16 and the drain pan 17, and heat exchange efficiency is reduced or water dripping (water leakage to the outside of the indoor unit 2A) occurs. Can be suppressed.

  In addition, 2A of indoor units make it easy to move the dew condensation adhering to the fin 20 of the heat exchanger 16 from the fin 20 of the heat exchanger 16 to the drain pan 17 by sticking the heat exchanger 16 and the drain pan 17 closely. Can do. Thereby, 2 A of indoor units can improve the efficiency which flows off the dust adhering to the heat exchanger 16.

<Modification>
The heat insulating material (foamed resin material) 111 used for the tray part 110 of the front drain pan 17F may be deformed as shown in FIGS. 17 and 18, for example. FIG. 17 is a schematic view of a heat insulating material (foamed resin material) 111A according to a modification. FIG. 17A shows a top view shape of the heat insulating material 111A, and FIG. 17B shows a cross-sectional shape of the heat insulating material 111A. FIG. 18 is a schematic view of a heat insulating material (foamed resin material) 111B according to a modification, and shows a shape of the heat insulating material 111B as viewed from above.

  In the example illustrated in FIG. 17A, the heat insulating material 111 </ b> A includes a plurality of substantially rectangular convex portions 212 arranged at equal intervals in the vertical direction and the horizontal direction, and a concave portion 213 between the convex portions 212. Is formed. As shown in FIG. 17B, the recess 213 has a substantially triangular shape widened upward. The recesses 213 have a depth h213 and a width t213, and are formed at equal intervals.

  Even if such a heat insulating material 111A does not wait for the water droplets of drain water to combine and grow into a large size water droplet by reducing the surface tension (binding force) of the drain water at the convex portion 212, It is possible to facilitate the flow of drain water in the state of small sized water droplets. Therefore, the indoor unit 2 </ b> A can use the heat insulating material 111 </ b> A to facilitate the flow of dust together with the drain water, and reduce the amount of dust remaining inside the drain pan 17. Moreover, since the convex part 212 is formed in the flow-path part, the heat insulating material 111A has a surface area larger than the heat insulating material 111 (refer FIG. 13). Thereby, 111 A of heat insulating materials can make it easier to evaporate the drain water which flowed into the flow-path part rather than the heat insulating material 111 (refer FIG. 13).

  In the example shown in FIG. 18, the heat insulating material 111 </ b> B is different from the heat insulating material 111 </ b> A (see FIG. 18) in that the convex portions 212 are arranged in a staggered arrangement. Similarly to the heat insulating material 111A, the heat insulating material 111B can reduce the surface tension (bonding force) of the drain water at the convex portion 212 and can easily flow the drain water. Further, the heat insulating material 111B has a surface area that is larger than that of the heat insulating material 111 (see FIG. 13) because the convex portion 212 is formed in the flow path portion, similarly to the heat insulating material 111A. Thereby, the heat insulating material 111B can make the drain water which flowed into the flow-path part easier to evaporate than the heat insulating material 111 (refer FIG. 13) similarly to the heat insulating material 111A.

  Moreover, you may deform | transform the shape of the drainage part 120 of the front drain pan 17F, for example, as shown in FIG. FIG. 19 is a schematic view of the drainage section 120 of the front drain pan 17F according to a modification.

  In the example shown in FIG. 19, a plurality (two in the illustrated example) of convex portions 122 </ b> A are formed on the bottom surface of the drainage portion 120. The convex portion 122A has a substantially triangular shape with a reduced width on the upper side. The protrusion 122A is formed so as to extend along the direction in which drain water flows (direction in which the flow path extends). The convex portion 122A is formed with a depth h122A and a width t122A. Such a drainage part 120 can make the drain water flow easily by reducing the surface tension (binding force) of the drain water at the convex part 122A.

As described above, according to the indoor unit 2A according to the second embodiment, it is possible to prevent water from leaking to the outside during freeze cleaning, as with the indoor unit 2 according to the first embodiment.
And since indoor unit 2A can make drain water flow easily, it can improve drainage efficiency of drain water. In addition, the indoor unit 2A can suppress moisture in the air from condensing and adhering to the drain pan 17.

DESCRIPTION OF SYMBOLS 1 Air conditioner 2, 2A Indoor unit 3 Outdoor unit 5 Connection piping 6 Air inlet 7, 7A, 7B, 7C, 107 Case 8 Cosmetic frame 9 Front panel 10 Receiving part 11 Display part 12 Remote controller 13 Air blower 14 Blower 15 Filter 16 Heat exchanger 16F Front heat exchanger 16R Rear heat exchanger 17 Drain pan 17F Front drain pan 17R Rear drain pan 18 Vertical wind direction plate 19 Left and right wind direction plate 20 Fin 21 (21a, 21b) Communication path 22 (22a, 22b) Drainage pipe 23,123 Drainage pipe inlet 24 Drainage pipe outlet 40 Pipe 110,160 Receptacle part 111,111A, 111B, 161,211 Heat insulating material (foamed resin material)
112, 122, 122A, 162, 172, 212 Convex part 120 Drain part 130 Concave part 213 Concave part BS1 Bottom face of front drain pan BS2 Bottom face near drain pipe inlet of front drain pan CL control part C22 Central axis of drain pipe h122A Convex part height h213 Depth of recess S22M Cross-sectional area near the center of the drainpipe S23, S123 Opening area of the inlet of the drainpipe t122A Projection spacing t213 Depth width α22 Inclination angle of drain

Claims (16)

A rear heat exchanger disposed behind the device for exchanging heat between air and refrigerant;
A pre-heat exchanger that is arranged in front of the device and exchanges heat between air and refrigerant;
A control unit for controlling a freezing operation for attaching frost or ice to the surfaces of the rear heat exchanger and the front heat exchanger;
A post-drain pan that receives drain water dripping from the post-heat exchanger;
A front drain pan that receives drain water dripping from the front heat exchanger and drain water flowing from the rear drain pan;
A communication path connecting the rear drain pan and the front drain pan;
A drain pipe for draining drain water collected in the front drain pan from the front drain pan to the outside of the device,
The volume (m ³ ) of all the drain pans combined with the rear drain pan and the front drain pan is the surface area x (m ² ) of all the heat exchangers combined with the rear heat exchanger and the front heat exchanger, And the amount of drainage from the drain pipe per unit time (m ³ / s) and the time required for all frost or ice to thaw or the time required for all the frost or ice to fall to the front drain pan or the rear drain pan (2.28 × 10 ⁻⁶ (m) × x (m ² ) −z × 10 ⁻⁶ (m ³ ) with respect to the value z × 10 ⁻⁶ (m ³ ) multiplied by the short time (s). )) Air conditioner indoor unit characterized by the above. In the indoor unit of the air conditioner according to claim 1,
The communication path is disposed at a position on both the left and right sides of the rear drain pan or a position in the vicinity of both sides, and a bottom surface thereof is inclined downward from the rear drain pan side toward the front drain pan side. An air conditioner indoor unit. In the indoor unit of the air conditioner according to claim 1,
The communication path is arranged at a position on one side of the left or right side of the rear drain pan or a position in the vicinity of one side, and its bottom surface is inclined downward from the rear drain pan side toward the front drain pan side,
An indoor unit of an air conditioner, wherein a bottom surface of the rear drain pan is inclined downward from a side far from the communication path toward a side close thereto. In the indoor unit of the air conditioner according to claim 1,
When the gravitational acceleration is set to g (m / s ² ) , the inner diameter R of the drain pipe and the front of the drain pan with respect to the volume y ₀ (m ³ ) of all the drain pans including the rear drain pan and the front drain pan. An indoor unit of an air conditioner characterized in that the depth h (m) of the drain pan satisfies the relationship of the following expression (1).

In the indoor unit of the air conditioner according to claim 1,
The indoor unit of an air conditioner, wherein a bottom surface of the front drain pan is inclined at least in the vicinity of an inlet of the drain pipe and downward from a side far from the inlet of the drain pipe toward a side closer to the drain pipe. In the indoor unit of the air conditioner according to claim 5,
The drain pipe is arranged such that the central axis is inclined downward from the inlet toward the outlet,
An indoor unit of an air conditioner, wherein an inclination angle of a central axis of the drain pipe is equal to or greater than an inclination angle of a bottom surface of the front drain pan in the vicinity of an inlet of the drain pipe. In the indoor unit of the air conditioner according to claim 1,
An indoor unit of an air conditioner, wherein an opening area of an inlet of the drain pipe is larger than a cross-sectional area near a center of the drain pipe. In the indoor unit of the air conditioner according to any one of claims 1 to 7,
The indoor unit of an air conditioner characterized in that the volume of the drain pan is equal to or greater than the total amount of frost or ice attached to the heat exchanger during the freezing operation. In the indoor unit of the air conditioner according to any one of claims 1 to 8,
The rear drain pan, the front drain pan, and the communication path form a flow path of the drain water,
The indoor unit of an air conditioner, wherein the flow path has a concavo-convex portion formed on a bottom surface at an arbitrary location. The indoor unit of the air conditioner according to claim 9,
The indoor unit of an air conditioner, wherein the uneven portion is formed along a direction in which the flow path extends. In the indoor unit of the air conditioner according to claim 9 or 10,
An indoor unit of an air conditioner, wherein a part of the bottom surface of the front drain pan is inclined downward from a far side to a near side to the drain pipe. The indoor unit of the air conditioner according to any one of claims 9 to 11,
The drain pipe is arranged such that the central axis is inclined downward from the inlet toward the outlet,
An indoor unit of an air conditioner, wherein an inclination angle of a central axis of the drain pipe is equal to or greater than an inclination angle of a bottom surface of the front drain pan in the vicinity of an inlet of the drain pipe. The air conditioner indoor unit according to any one of claims 9 to 12,
An indoor unit of an air conditioner, wherein a recess is formed in a bottom surface near the outlet of the flow path. The indoor unit of the air conditioner according to any one of claims 9 to 13,
The indoor unit of an air conditioner, wherein a first heat insulating member is disposed on a back side of a flow path portion extending in the front-rear direction of the front drain pan. The indoor unit of the air conditioner according to any one of claims 9 to 14,
The indoor unit of an air conditioner, wherein a second heat insulating member is disposed on the front side of the flow path portion extending in the left-right direction of the front drain pan. The indoor unit of the air conditioner according to any one of claims 9 to 15,
Furthermore, it has a blower fan arranged between the rear heat exchanger and the front heat exchanger,
The front heat exchanger and the front drain pan are disposed so as to contact each other, thereby blocking a space between the space where the blower fan is disposed and a space outside the space. Air conditioner indoor unit.

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