CN109154445B

CN109154445B - Indoor unit of air conditioner

Info

Publication number: CN109154445B
Application number: CN201780011595.2A
Authority: CN
Inventors: 熊本光佑; 田中幸范; 粟野真和; 吉田和正; 能登谷义明
Original assignee: Hitachi Johnson Controls Air Conditioning Inc
Current assignee: Hitachi Johnson Controls Air Conditioning Inc
Priority date: 2017-04-28
Filing date: 2017-10-03
Publication date: 2020-02-04
Anticipated expiration: 2037-10-03
Also published as: EP3438559B1; TWI644063B; JP6340111B1; WO2018198400A1; EP3438559A1; EP3438559A4; CN109154445A; JP2018189271A; MY173637A; TW201839330A

Abstract

The invention provides an indoor unit of an air conditioner, which prevents water from leaking to the outside during freezing and cleaning. An indoor unit (2) of an air conditioner is provided with a heat exchanger (16) that exchanges heat between air and a refrigerant, a drain pan (17) that receives drain water dripping from the heat exchanger (16), and a control unit that controls a freezing operation in which frost or ice adheres to the surface of the heat exchanger. The volume of the drain pan (17) is equal to or more than the total adhering amount of frost or ice adhering to the heat exchanger (16) during freezing operation. Considering the case where the drain water is discharged to the outside of the indoor unit (2) through the drain pipe, the indoor unit (2) may preferably be configured such that the volume of the drain pan (17) is equal to or more than [ the total adhering amount of frost or ice-the drain amount of the drain pipe per unit time × the shorter time of the time required for thawing all frost or ice and the time required for all frost or ice to fall down to the drain pan ].

Description

Indoor unit of air conditioner

Technical Field

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

Background

An indoor unit of an air conditioner sucks indoor air into the interior, passes the sucked indoor air through a heat exchanger to obtain conditioned air subjected to any one of heating, cooling, and dehumidification, and blows out the obtained conditioned air into the room to condition the air in the room.

In an indoor unit of an air conditioner, a filter is disposed so as to block a space between an air inlet for sucking indoor air and a heat exchanger so that dust contained in the indoor air does not enter the indoor unit, and most of the dust is collected by the filter. However, dust finer than the mesh of the filter is hidden in the mesh of the filter and enters the inside of the indoor unit.

In the indoor unit, static electricity is generated around the heat exchanger due to friction when the sucked indoor air collides with the heat exchanger. In addition, the fine dust entering the indoor unit often contains oil. Therefore, the dust entering the indoor unit adheres to the heat exchanger due to static electricity and oil.

The dust adhering to the heat exchanger contains a component that serves as a nutrient for miscellaneous bacteria (including mold). Therefore, if the air conditioner performs the cooling operation or the dehumidifying operation in summer, for example, moisture in the air is condensed on the fins of the heat exchanger, and the periphery of the heat exchanger is in a high-humidity state. Therefore, if dust continues to adhere to the heat exchanger, undesired bacteria (including mold) may propagate and cause an offensive odor. Therefore, it is desirable that the air conditioner remove dust attached to the heat exchanger and keep the heat exchanger clean over the course of one year.

For this reason, for example, patent document 1 proposes an air conditioner in which a cooling operation or a dehumidifying operation is performed after a heating operation, water is attached to the surfaces of fins of a heat exchanger, and oil-containing dust attached to the surfaces of the fins is caused to flow down by the attached water. However, in the air conditioner described in patent document 1, in order to cause dust to flow off by water adhering to the surfaces of the fins, it is necessary to perform an antifouling treatment on the surfaces of the fins.

Thus, for example, the following techniques are studied: the operation of reducing the temperature of the heat exchanger is performed to adhere frost or ice to the surfaces of the fins, and then the operation of increasing the temperature of the heat exchanger is performed to thaw the frost or ice and to cause dust adhering to the heat exchanger to flow down by the potential head of the thawed water falling. Hereinafter, the process of cleaning the heat exchanger in this way is referred to as "freeze cleaning". This freeze cleaning can cause a large amount of frost (including ice) to adhere to the surfaces of the fins, which is larger than the amount of water adhering to the surfaces of the fins per unit time in the normal cooling operation or dehumidifying operation. Therefore, even if the surface of the fin is not subjected to the stain-proofing treatment, the dust attached to the heat exchanger can be caused to flow down by the freeze cleaning.

Documents of the prior art

Patent document

Patent document 1: japanese laid-open patent publication No. 2008-138913

Disclosure of Invention

Problems to be solved by the invention

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

The present invention has been made to solve the above problems, and a main object of the present invention is to provide an indoor unit of an air conditioner that does not leak water to the outside during freezing and washing.

Means for solving the problems

In order to achieve the above object, the present invention provides an indoor unit of an air conditioner, comprising: a rear heat exchanger disposed behind the apparatus and exchanging heat between the air and the refrigerant; a front heat exchanger disposed in front of the apparatus and exchanging heat between air and the refrigerant; a control unit for controlling a freezing operation for causing frost or ice to adhere to the surfaces of the rear heat exchanger and the front heat exchanger, and a rear drain pan for receiving drain water dripping from the rear heat exchanger; a front drain pan for receiving drain water dropped 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; and a drain pipe for discharging drain water stored in the front drain pan from the front drain pan to the outside of the apparatus, the drain water being larger than a surface area x (m) of the entire heat exchanger in which the rear heat exchanger and the front heat exchanger are added together²) To therebyAnd the amount of water discharged from the water discharge pipe per unit time (m)³/s) is multiplied by a value z × 10 obtained by multiplying a shorter time(s) of a time(s) required for thawing all of the frost or ice and a time(s) required for all of the frost or ice to fall down to the front drain pan or the rear drain pan^-6(m³) The volume (m) of the whole drain pan combined with the rear drain pan and the front drain pan³) Is [ 2.28X 10]^-6(m)×x(m²)-z×10^-6(m³)]The above.

Other schemes are described later.

Effects of the invention

According to the present invention, water can be prevented from leaking to the outside during freeze washing.

Drawings

Fig. 1 is a configuration diagram of an air conditioner according to embodiment 1.

Fig. 2 is a sectional view of an indoor unit of an air conditioner according to embodiment 1.

Fig. 3 is a perspective view of a drain pan portion of a casing used in the indoor unit according to embodiment 1.

Fig. 4 is a partially enlarged view of a front drain pan of the drain pan portion.

Fig. 5 is a graph showing a relationship between the surface area of the heat exchanger and the amount of drain water generated by freeze cleaning.

Fig. 6 is a schematic diagram showing the arrangement structure of the drain pipe of the drain pan portion.

Fig. 7 is a schematic diagram showing another arrangement configuration of the drain pipe of the drain pan portion.

Fig. 8 is a schematic diagram showing an inlet structure of a drain pipe of the drain pan portion.

FIG. 9 is a schematic diagram showing an alternative inlet configuration for the drain pipe of the drain pan section.

Fig. 10A is a schematic view (1) of a drain pan portion of a tank of a modification.

Fig. 10B is a schematic view (2) of a drain pan portion of the tank of the modification.

Fig. 10C is a schematic view (3) of a drain pan portion of the tank of the modification.

Fig. 11 is a perspective view of a drain pan portion of a casing used in an indoor unit according to embodiment 2.

Fig. 12 is a partially enlarged view of a front drain pan of the drain pan portion.

Fig. 13 is a perspective view of the heat insulator used in embodiment 2.

Fig. 14 is a partially enlarged view (1) of the drain portion of the front drain pan.

Fig. 15 is a partially enlarged view (2) of the drain portion of the front drain pan.

Fig. 16 is a schematic diagram showing the arrangement relationship between the heat exchanger and the front drain pan.

Fig. 17 is a schematic view (1) of a heat insulator according to a modification.

Fig. 18 is a schematic view (2) of an insulator according to a modification.

Fig. 19 is a schematic view of a drain portion of a front drain pan of a modification.

Detailed Description

Hereinafter, embodiments of the present invention (hereinafter, referred to as "the present embodiment") will be described in detail with reference to the drawings. The drawings are only schematic to the extent that the present invention can be fully understood. Therefore, the present invention is not limited to the illustrated examples. In the drawings, the same reference numerals are given to the common components and the same components, and redundant description thereof will be omitted.

[ embodiment 1]

< Structure of air conditioner

The structure of the air conditioner 1 according to embodiment 1 will be described below with reference to fig. 1 and 2. Fig. 1 is a configuration diagram of an air conditioner 1 according to embodiment 1. Fig. 2 is a sectional view of the indoor unit 2 of the air conditioner 1.

As shown in fig. 1, the air conditioner 1 includes an indoor unit 2 disposed indoors, an outdoor unit 3 disposed outdoors, and a remote controller 12 disposed near the user's hand in the room.

The indoor unit 2 sucks indoor air into the interior, passes the sucked indoor air through the heat exchanger 16 (see fig. 2), obtains conditioned air subjected to any one of heating, cooling, and dehumidification, and blows out the obtained conditioned air into the room to condition the air in the room. The indoor unit 2 is connected to the outdoor unit 3 via a connection pipe 5, and circulates a refrigerant with the outdoor unit 3. The outdoor unit 3 exchanges heat with the circulating refrigerant.

The indoor unit 2 includes a casing 7 and a decorative frame 8, and structural members such as a blower fan 14 (see fig. 2) and a heat exchanger 16 (see fig. 2) are incorporated therein. The blower fan 14 is a cross-flow fan that sends air from the air inlet 6 side to the air outlet 13 side. The heat exchanger 16 exchanges heat with the refrigerant.

In the example shown in fig. 1, the front surface of the bezel 8 has a shape including an upper portion extending in the vertical direction and a lower portion extending in the oblique rear direction. A front surface panel 9 is attached to an upper portion of the front surface of the bezel 8. The front panel 9 is a member that covers the front surface of the indoor unit 2. Further, a receiving portion 10, a display portion 11, and a vertical wind direction plate 18 are attached to a lower portion 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 receiver 10 is electrically connected to a control unit CL built in the indoor unit 2. The control unit CL controls the operation of the air conditioner 1 based on the operation signal received from the remote controller 12 via the receiving unit 10. The display unit 11 is a device for displaying the operating state.

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 up-down wind direction plate 18 is pivotally supported near the lower end by the decorative frame 8 (or the casing 7) so that the upper portion is opened and closed in the up-down direction, and is configured to be rotatable by a drive unit (not shown). The indoor unit 2 opens the vertical wind direction plate 18 to form the air outlet 13.

As shown in fig. 2, the indoor unit 2 includes, inside thereof, a filter 15, a drain pan 17, and a horizontal wind direction plate 19 in addition to the above-described blower fan 14, the above-described heat exchanger 16, and the above-described vertical wind direction plate 18.

The filter 15 is a member for preventing dust from entering the case 7. The drain pan 17 is a member that receives water (drain water) that has condensed on the surface of the fin 20 of the heat exchanger 16 and has fallen. The horizontal air vanes 19 are members that define the direction of the conditioned air discharged from the air outlet 13 in the horizontal direction.

The filter 15 is disposed so as to block a space between the air intake port 6 and the heat exchanger 16. The air conditioner 1 is configured such that the filter 15 prevents dust larger than the mesh size of the filter 15 from entering the inside of the casing 7, and such that dust smaller than the mesh size of the filter 15 that has passed through the mesh size of the filter 15 is washed away by freeze washing, which will be described later. The air conditioner 1 is preferably configured to have a filter cleaning mechanism (not shown) and automatically (more preferably, periodically) clean the filter 15 by the filter cleaning mechanism.

The blower fan 14 is disposed in the vicinity of the substantial center of the inside of the indoor unit 2 so as to be able to suck air from the air inlet 6 and blow out the air from the air outlet 13. The heat exchanger 16 is disposed on the upstream side (on the side closer to the air inlet 6) of the blower fan 14, 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 is constituted by a front heat exchanger 16F and a rear heat exchanger 16R. The front heat exchanger 16F and the rear heat exchanger 16R are each provided with a plurality of fins (heat exchange plates) 20 and a plurality of tubes 40 penetrating the fins 20. The fins 20 are long, thin plate-like members for exchanging heat between the refrigerant and the air. The fin 20 is made of, for example, an aluminum alloy. The tube 40 is a member for flowing the refrigerant.

In this configuration, the indoor unit 2 collects most of dust in the indoor air sucked into the interior by the filter 15. However, a part of the dust is not collected by the filter 15, but enters the indoor unit 2 through the mesh hidden in the filter 15, and adheres to the heat exchanger 1. If the dust continues to adhere to the heat exchanger 16, there is a possibility that bacteria (including mold) may propagate to generate offensive odor. Therefore, the air conditioner 1 is preferably configured to remove dust adhering 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 the following operations: the operation of lowering the temperature of the heat exchanger 16 is performed to rapidly cool the heat exchanger 16, and frost or ice is attached to the surface of the fins 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".

Further, it can be considered that: in the freezing operation, frost (including ice) is directly attached to the surface of the fin 20 of the heat exchanger 16 by sublimating moisture in the air without passing through water droplets. However, there is a possibility that frost (ice) is condensed on the surfaces of the fins 20 of the heat exchanger 16 by moisture in the air and the condensed moisture is frozen, and the frost (ice) passes through water droplets and adheres to the surfaces of the fins 20 of the heat exchanger 16.

In the freezing operation, unlike the normal cooling operation, the air conditioner 1 does not operate the blower fan 14. Thus, the air conditioner 1 can suppress the drop (dripping) of water (condensed water) condensed on the surfaces of the fins 20 of the heat exchanger 16, and can extend the residence time of the water (condensed water) on the surfaces of the fins 20. As a result, the air conditioner 1 can ensure a stable amount of water frozen.

After the freezing operation, the air conditioner 1 performs the following operations: the operation of raising the temperature of the heat exchanger 16 is performed to rapidly heat the heat exchanger 16 and thaw (melt) the frost (ice) (hereinafter, referred to as "thawing operation"). In the present embodiment, the operation for performing the thawing operation is referred to as "thawing operation". The air conditioner 1 performs a defrosting operation to return frost (ice) to water. At this time, the air conditioner 1 causes fine dust adhering to the heat exchanger 16 to flow down by the falling potential of thawed (melted) water. This improves the maintainability of the heat exchanger 16, and enables the air conditioner 1 to efficiently clean the heat exchanger 16. Hereinafter, this cleaning process (cleaning process by the freezing operation and the thawing operation) is referred to as "freeze cleaning".

The drain pan 17 for the air conditioner 1 receives water (drain water) flowing out during the defrosting operation. A flow path through which water (drain water) flows is formed in the drain pan 17. 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 discharges the outflow water (drain water) to the outside of the casing 7 through the drain pipe.

< Structure of drainage tray >

The structure of the drain pan 17 will be described below with reference to fig. 3 to 6. In the present embodiment, a structure in which the drain pan 17 is formed integrally with the case 7 will be described. Fig. 3 is a perspective view of the drain pan portion of the tank 7. Fig. 4 is a partially enlarged view of the front drain pan 17F of the drain pan portion. Fig. 5 is a graph showing a relationship between the surface area of the heat exchanger 16 and the amount of drain water generated by freeze washing. Fig. 6 is a schematic diagram showing the arrangement structure of the drain pipe 22 of the drain pan section.

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 17F disposed below the front heat exchanger 16F (see fig. 2). In the present embodiment,

communication passages

21a, 21b are provided on both sides of the rear drain pan 17R. In addition,

drain pipes

22a and 22b are provided on both sides of the front drain pan 17F. Hereinafter, the

communication paths

21a and 21b will be collectively referred to as "communication paths 21". When the

drain pipes

22a and 22b are collectively referred to, the drain pipe 22 is referred to as "drain pipe".

The rear drain pan 17R receives water dropped from the rear heat exchanger 16R (see fig. 2). The bottom surface of the rear drain pan 16R is inclined downward from the side far from the communication path 21 toward the side close thereto. In the present embodiment, the bottom surface of the rear drain pan 16R is formed in a shape that is higher near the approximate center in the left-right direction and lower at the left and right ends than the bottom. Thus, water dropping 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 communication path 21 is inclined downward from the rear drain pan 16R side toward the front drain pan 16F side. Thus, water dropping 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 17F communicates with the drain pipe 22. In the present embodiment, the drain pipe 22 is formed as a circular pipe integral with the casing 7, and has a structure in which an inlet 23 thereof opens into the front drain pan 17F.

The front drain pan 17F receives water dropped from the front heat exchanger 16F (see fig. 2). Further, water dropping from the rear heat exchanger 16R (see fig. 2) flows from the rear drain pan 16R side into the front drain pan 17F. 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 discharged to the outside of the indoor unit 2 through the drain pipe 22. Hereinafter, 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 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) greater 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 the dehumidifying operation adheres to the rear heat exchanger 16R and the front heat exchanger 16F. During the defrosting operation, frost (ice) adhering to the rear heat exchanger 16R and the front heat exchanger 16F is defrosted at the same time. As a result, during freeze cleaning, a large amount of drain water is generated, which is larger than the amount of water generated per unit time in the normal cooling operation or dehumidifying operation, and drops to both the rear drain pan 17R and the front drain pan 17F.

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 defrosting operation, the drain water overflows from the front drain pan 17F or the rear drain pan 17R until the drain water is discharged to the outside of the indoor unit 2 through the

drain pipes

22a and 22 b. As a result, the drain water leaks to the outside of the indoor unit 2. Therefore, it is desirable that the air conditioner 1 does not leak a large amount of drain water generated during the defrosting operation to the outside of the indoor unit 2. Therefore, the drain pan 17 is desirably provided with a volume that does not overflow a large amount of drain water generated during the defrosting operation.

Therefore, in the indoor unit 2 of the present embodiment, the volume of all the drain pans 17 added together between the rear drain pan 17R and the front drain pan 17F is equal to or greater than the total adhering amount of frost or ice adhering to the heat exchanger 16 during the freezing operation. However, when the drain water is discharged to the outside of the indoor unit 2 through the drain pipe 22, the indoor unit 2 is preferably configured such that the volume of the drain pan 17 is equal to or greater than [ the total amount of frost or ice adhering to the heat exchanger 16 during the freezing operation, the drain amount per unit time of the drain pipe × the shorter time required for thawing all of the frost or ice, and the shorter time required until all of the frost or ice falls to the drain pan ]. This point will be described in detail below.

Fig. 5 shows a relationship between the surface area of all the heat exchangers 16, which are the sum of the rear heat exchanger 16R and the front heat exchanger 16F, and the amount of drain water (the total amount of frost or ice adhering) generated during freeze washing. Fig. 5 shows the experimental results measured when the air conditioner 1 was subjected to freeze washing under the conditions of an indoor temperature of 27 ℃ and an indoor humidity of 35%. As shown in FIG. 5, according to the experiment, for example, the surface area of the entire heat exchanger 16 in which the rear heat exchanger 16R and the front heat exchanger 16F are added up is 15 (m)²) In the case of (2), 34.2(ml) ═ 34.2 × 10 was produced^-6(m³) The drain water of (1). That is, the amount of drain water (the total amount of frost or ice adhered) generated during the defrosting operation is w (m)³) And the surface area of the heat exchanger 16 is x (m)²) In the case of (2), the amount w (m) of drain water³) Relative to the surface area x (m) of the heat exchanger 16²) Is [ w ═ 2.28 (m). times.10^-6×x(m²)]The relationship (2) of (c). In addition, the coefficient 2.28 has a dimension (dimension: unit) of length (here, m (meters)), so that the dimension of w is the volume (m (meters)), and thus³)。

In the case where freeze cleaning is performed in an environment where the indoor humidity is lower than that in the experiment of fig. 5, the surface area x (m) of the heat exchanger 16 is also used²) Similarly, the same freezing time also reduces the amount of drain water generated after defrosting of frost (ice). In the case of performing freeze washing in an environment having a higher indoor humidity than in the experiment of fig. 5, the drain water generated after defrosting of frost (ice) can be adjusted by adjusting the freezing time. Therefore, in the indoor unit 2, if the volume y of the drain pan 17 is the sum of the rear drain pan 17R and the front drain pan 17F₀(m³) Is w (m)³) Above, i.e., [ y₀＝2.28×10^-6×x](m³) As described above, the drain water generated by the freeze washing can be prevented from leaking to the outside. Thus, the volume y of the drain pan 17₀(m³) Preferably 2.28 (m). times.10^-6×x(m²) The above.

However, the value y mentioned above₀(m³) Is the volume of the drain pan 17 when the drain water is drained from the front drain pan 17F to the outside of the outdoor unit 2 by the drain pipe 22 without consideration. In contrast, the indoor unit 2 performs a drainage process of draining water from the front drain pan 17F to the outside of the outdoor unit 2 through the drain pipe 22 in parallel with the defrosting process of frost (ice).

Therefore, the indoor unit 2 can set the value y described above in consideration of the drainage process of the drain water₀(m³) The amount of drainage of the drain water discharged by the drainage treatment (for example, z × 10)^-6(m³) Value y after (c)₁(m³) The volume of the drain pan 17 is set. That is, in consideration of the drainage processing of the drain water, in the indoor unit 2, if the volume y of all the drain pans 17 is the sum of the rear drain pan 17R and the front drain pan 17F₁(m³) Is [ w-zx 10]^-6](m³) Above, i.e., [ y₁＝2.28×10^-6×x-z×10^-6＝(2.28x-z)×10^-6](m³As described above, the drain water generated by the freeze washing can be prevented from leaking to the outside. Therefore, the volume y of the drain pan 17 in the case of considering the drainage processing of the drain water₁(m³) Preferably (2.28 x-z). times.10^-6(m³) The above.

The above-mentioned value (2.28 x-z). times.10^-6Value of (2.28x 10)^-6Corresponding to the total adhesion amount (m) of frost or ice³)]. In addition, the value z × 10^-6Corresponding to [ the amount of water discharged (m) of the drain pipe 22 per unit time ]³S) x the shorter time(s) of the time required for thawing the whole frost or ice and the time required until the whole frost or ice falls down to the drain pan 17]. Therefore, in other words, in the indoor unit 2, if the drainage processing of the drain water is considered, the volume y of the drain pan 17₁(m³) Is [ total attachment of frost or ice (m) ]³) Fluence (m)³) The displacement (m) of the drain pipe 22 per unit time³S) x time required for thawing the whole frost or ice and a shorter time(s) required until the whole frost or ice falls down to the drain pan 17]Thus, the freezing can be prevented from being clearedThe drain water generated by the washing leaks to the outside.

Further, as the volume of the drain pan 17, the above-described value y can be selectively applied according to the operation₀(m³) Or the above value y is applied₁(m³). In applying the above value y₀(m³) As the volume of the drain pan 17, since the volume of the drain pan 17 is large, a large limit can be set for the drain water overflowing from the drain pan 17, although the indoor unit 2 is large-sized. On the other hand, in applying the above value y₁(m³) As the volume of the drain pan 17, the volume of the drain pan 17 can be reduced, and therefore, the indoor unit 2 can be downsized.

In addition, in the indoor unit 2, it is preferable that the drain pan 17 is provided with a volume that prevents a large amount of drain water generated during the defrosting operation from overflowing, and that the drain water is allowed to easily drain all of the drain water to the outside of the indoor unit 2 through the drain pipe 22 without overflowing from the drain pan 17F. Here, the "entire drain water" refers to water obtained by adding the drain water dropped from the rear heat exchanger 16R and the drain water dropped from the front heat exchanger 16F.

Therefore, in the present embodiment, the indoor unit 2 is configured such 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 the expression (9) described later. 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 a product of the cross-sectional area of the inside of the drain pipe 22, which is a circular pipe, and the outflow speed of the drain water. Therefore, the flow rate of the drain water flowing through the drain pipe 22 per unit time is defined as "Q" (m)³S), the inner diameter of the drain pipe 22 is set to "R" (m), and the radius thereof is set to "R" (m) (that is, [ R ═ 2R ″)]) When the outflow speed of the drain water flowing through the drain pipe 22 is "v" (m/s), the flow rate "Q" (m) of the drain water flowing through the drain pipe 22 per unit time is set to³And/s) is a relationship of the following formula (1).

[ formula 1]

Q＝r²πv...(1)

In addition, if it is going to be beforeThe depth of the drain pan 17F is set to "h" (m), and the gravitational acceleration is set to "g" (m/s)²) Then, according to the "tolikeli theorem", the outflow velocity "v" (m/s) of the drain water flowing through the drain pipe 22 is in the relationship of the following expression (2). The "trinity theorem" relates to the outflow rate of liquid when a relatively small hole is formed in the side surface of a container in which liquid is placed. The depth "h" of the front drain pan 17F is a value from the upper limit of the amount of the drain water not to overflow to the bottom BS1 of the front drain pan 17F.

[ formula 2]

The following formula (3) is obtained by substituting the above formula (2) into the above formula (1).

[ formula 3]

Here, the flow rate "Q" (m) of the drain water flowing through the drain pipe 22 per unit time³(s) is the amount of drainage water (the total amount of adhered frost or ice) "w" (m) generated during the defrosting operation per hour (3600 seconds)³) The flow rate of (c). The amount of drain water (the total amount of frost or ice adhered) "w" corresponds to the required volume y of the drain pan 17₀(m³). Therefore, the flow rate "Q" (m) of the drain water flowing through the drain pipe 22 per unit time³And/s) is a relationship of the following formula (4).

[ formula 4]

The following formula (5) is obtained by substituting the above formula (4) into the above formula (3).

[ formula 5]

From the above formula (5), the following formula (6) can be obtained.

[ formula 6]

From the above formula (6), the following formula (7) can be further obtained.

[ formula 7]

Since the inner diameter "R" of the drain pipe 22 is [ R ═ 2R ], the following formula (8) can be obtained from the above formula (7).

[ formula 8]

By making the inner diameter "R" larger than the value of the relationship of the above equation (8), the drain water 22 can easily discharge all the drain water to the outside of the indoor unit 2 through the drain pipe 22 without causing the drain water to overflow from the front drain pan 17F. 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 following expression (9), the drain pipe 22 can easily discharge all of the drain water to the outside of the indoor unit 2 through the drain pipe 22 without allowing the drain water to overflow from the front drain pan 17F.

[ formula 9]

In addition, y₀(m³) The volume of the entire drain pan 17 obtained by adding the rear drain pan 17R and the front drain pan 17F to the surface area x (m) of the entire heat exchanger 16 obtained by adding the rear heat exchanger 16R and the front heat exchanger 16F²) Becomes [ y ]₀＝2.28×10^-6×x]The relationship (2) of (c). Further, the inner diameter R of the drain pipe 22 is preferably, for example, set to be11(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 equation (9). Such an indoor unit 2 can discharge drain water to the outside of the indoor unit 2 before the drain water overflows from the front drain pan 17F. Further, the indoor unit 2 can discharge a large amount of drain water generated in the freeze washing without inefficiently enlarging the casing 7.

Further, as shown in fig. 6, the drain pipe 22 is preferably configured such that the center axis C22 is inclined downward from the inlet 23 toward the outlet 24. This enables the indoor unit 2 to smoothly discharge the drain water stored in the front drain pan 17F to the outside.

During the freeze cleaning, dust adhering to the front heat exchanger 16F and the rear heat exchanger 16R together with the drain water also flows down. Therefore, the drainage water and dust are mixed together to form sludge near the inlet 23 of the drainage pipe 22, and easily accumulated. As a result, the sludge-like drainage water and dust may flow into the drainage pipe 22.

However, in the indoor unit 2, the drain pipe 22 is disposed at an angle, so that the drain water and dust flowing into the drain pipe 22 easily fall due to their own weight. Therefore, even if the sludge-like drainage water and dust flow into the inside of the drainage pipe 22, the indoor unit 2 can satisfactorily discharge them to the outside. Such an indoor unit 2 can maintain the inside of the drain pipe 22 in a state suitable for draining the drain water. In addition, the indoor unit 2 itself can suppress accumulation of drain water and dust 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 stored 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, and as shown in fig. 7, the front drain pan 17F is configured such that the bottom surface BS2 near the inlet 23 of the drain pipe 22 is inclined downward from the side away from the inlet 23 of the drain pipe 22 toward the side close thereto, that is, the front drain pan 17F has a shape in which a concave portion is formed in the bottom surface near the outlet of the flow path, and the inclination angle α 22 of the central axis C22 of the drain pipe 22 is equal to or greater than the inclination angle α 17 of the bottom surface BS1 of the front drain pan 17F near the inlet 23 of the drain pipe 22, and thus, in the indoor unit 2, the drain water containing dust accumulated in the front drain pan 17F is easily made to flow in the direction of the drain pipe 22 by its own weight, and as a result, the indoor unit 2 can more smoothly discharge the drain water accumulated in the front drain pan 17F than the structure shown in fig. 6, and as a result, the indoor unit 2 can improve the drain efficiency of.

The inlet 23 of the drain pipe 22 may also be deformed as shown in fig. 8 or 9, for example. Fig. 8 is a schematic diagram 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 of the periphery thereof 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. Thus, 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 9, the drain pipe 22 can effectively take the drain water stored in the front drain pan 17F and discharge the drain water to the outside. This enables the indoor unit 2 to efficiently introduce the drain water containing dust into the drain pipe 22. Therefore, even if the drainage water and dust are mixed together near the inlet 23 of the drainage pipe 22 and become a sludge and are difficult to discharge, the indoor unit 2 can guide them into the drainage pipe 22 and can satisfactorily send them out to the outside. This also suppresses the accumulation of drain water and dust in the vicinity of the inlet 23 of the drain pipe 22 in the indoor unit 2 itself. As a result, the indoor unit 2 can improve the drainage efficiency of the drain water stored in the front drain pan 17F.

< modification of drain pan part of tank >

The drain pan portion of the tank 7 may be deformed as in the case of the

tanks

7A, 7B, and 7C shown in fig. 10A to 10C, for example. Fig. 10A to 10C are schematic views each showing a modification of the drain pan portion of the case 7.

In the example shown in fig. 10A, the tank 7A is different from the tank 7 shown in fig. 3 in that: the rear drain pan 17R is formed in a shape elongated in the left-right direction; and the communicating

portions

21a, 21b are disposed at positions on the near side of the rear drain pan 17R. Therefore, in the case 7A, the

communication passages

21a and 21b are disposed in the vicinity of both the right and left sides of the rear drain pan 17R. The

communication passages

21a and 21b are formed such that the bottom surfaces thereof 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 case 7B is different from the case 7 shown in fig. 3 in that: the communication passage 21 is disposed only at one of the left and right sides of the rear drain pan 17R. The rear drain pan 17R is formed such that its bottom surface is inclined downward from the side away from the communication path 21 toward the side close thereto.

In the example shown in fig. 10C, the tank 7C is different from the tank 7B shown in fig. 10B in that: the rear drain pan 17R is formed in a shape elongated in the left-right direction; and the communication passage 21 is disposed at a position on the near side of the rear drain pan 17R.

As shown in the

cases

7A, 7B, and 7C shown in fig. 10A to 10C, the communication path 21 may be disposed not on both sides of the front drain pan 17F and the rear drain pan 17R but in the vicinity of both left and right sides of the rear drain pan 17R, at a left and right side position of the rear drain pan 17R, or at a position in the vicinity of one side thereof. Thereby, the communication passage 21 can communicate the front drain pan 17F and the rear drain pan 17R. The bottom surface of the rear drain pan 17R is configured to be slightly lower on the side closer to the

communication passages

21a and 21b than on the side farther from the communication passages. The

cases

7A, 7B, and 7C shown in fig. 10A to 10C can improve the degree of freedom of the arrangement structure of the communication path 21 and can improve the drainage of the drain water dripping from the rear heat exchanger 16R to the rear drain pan 17R.

Further, the indoor unit 2 can suppress the accumulation of drain water and dust in the vicinity of the inlet 23 of the drain pipe 22 by appropriately combining the configurations shown in fig. 6 to 10C. As a result, the indoor unit 2 can improve the drainage efficiency of the drain water stored in the front drain pan 17F.

< main characteristics of indoor unit >

(1) The true bookIn the indoor unit 2 according to the embodiment, the volume of the drain pan 17 is equal to or greater than the total adhering amount w of frost or ice adhering to the heat exchanger 16 during the freezing operation. Further, considering the case where the drain water is drained to the outside of the indoor unit 2 through the drain pipe 22, the indoor unit 2 may be configured such that the volume of the drain pan 17 is shorter than the total adhering amount of frost or ice, the drain amount per unit time of the drain pipe 22, the time required to thaw all of the frost or ice, and the time required until all of the frost or ice falls down to the drain pan 17]The above. In this case, the surface area x (m) of the entire heat exchanger obtained by adding the rear heat exchanger 16R and the front heat exchanger 16F may be set to be equal to the total surface area x of the heat exchangers²) And a discharge amount (m) per unit time from the drain pipe³/s) is multiplied by a value z × 10 obtained by multiplying a shorter time(s) of a time required for thawing all of the frost or ice and a time required until all of the frost or ice falls to the front drain pan or the rear drain pan^-6(m³) The total drain pan volume (m) of the rear drain pan 16R and the front drain pan 16F³) Is 2.28X 10^-6(m)×x(m²)-z×10^-6(m³)＝(2.28x-z)×10^-6(m³) The above.

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

(2) The communication path 21 may be disposed at both right and left sides of the rear drain pan 17R or at positions near both sides, and may be configured such that 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 may be disposed at a position on one side or a position near one side of the rear drain pan 17R, and the bottom surface thereof may be inclined downward from the rear drain pan 17R side toward the front drain pan 17F side (see fig. 10B or 10C). In this structure, the bottom surface of the rear drain pan 17R is preferably formed to be inclined downward from the side away 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 path 21 and can improve the drainage of the drain water dripping from the rear heat exchanger 16R to the rear drain pan 17R.

(3) The gravity acceleration is set as g (m/s)²) In the case of (1), the volume y of the drain pan 17 is set to the total volume y of the rear drain pan 17R and the front drain pan 17F₀(m³) The inner diameter R of the drain pipe 22 and the depth h (m) of the front drain pan 17F preferably satisfy the relationship of the following expression (10).

[ formula 10]

Such an indoor unit 2 can discharge drain water to the outside of the indoor unit 2 before the drain water overflows from the front drain pan 17F. Further, the indoor unit 2 can satisfactorily discharge a large amount of drain water generated by the freeze washing without unnecessarily enlarging the casing 7.

(4) The bottom surface of the front drain pan 17F is inclined downward from the side away from the inlet 23 of the drain pipe 22 toward the side close to the inlet 23 of the drain pipe 22 at least in the vicinity of the inlet 23 of the drain pipe 22 (see fig. 7).

In the indoor unit 2, even when the drainage water and the dust are mixed together to form a sludge near the inlet 23 of the drain pipe 22, the drainage water and the dust in the sludge state can be satisfactorily discharged into the drain pipe 22. Such an indoor unit 2 can maintain the inside of the drain pipe 22 in a state suitable for draining the drain water. In addition, the indoor unit 2 itself can suppress accumulation of drain water and dust 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 stored in the front drain pan 17F.

(5) The drain pipe 22 is arranged such that the center axis C22 is inclined downward from the inlet 23 toward the outlet 24, and the inclination angle α 22 of the center axis C of the drain pipe 22 is equal to or greater than the inclination angle α 17 of the bottom BS2 of the front drain pan 17F in the vicinity of the inlet 23 of the drain pipe 22 (see fig. 7).

In the indoor unit 2, the dust-containing drain water stored in the front drain pan 17F is easily caused to flow in the direction of the drain pipe 22 by its own weight. Therefore, the indoor unit 2 can smoothly discharge the drain water stored in the front drain pan 17F. As a result, the indoor unit 2 can improve the drainage efficiency of the drain water stored 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 fig. 8 and 9).

In the indoor unit 2, the drain pipe 22 can efficiently take out the dust-containing drain water stored in the front drain pan 17F and discharge the dust-containing drain water to the outside. This enables the indoor unit 2 to efficiently introduce the drain water containing dust into the drain pipe 22. Therefore, even if the drainage water and dust are mixed together in the vicinity of the inlet 23 of the drainage pipe 22 and are difficult to be discharged, the indoor unit 2 can introduce them into the drainage pipe 22 and can satisfactorily send them out to the outside. This also suppresses the accumulation of drain water and dust in the vicinity of the inlet 23 of the drain pipe 22 in the indoor unit 2 itself. As a result, the indoor unit 2 can improve the drainage efficiency of the drain water stored in the front drain pan 17F.

As described above, according to the indoor unit 2 of the air conditioner 1 of embodiment 1, water can be prevented from leaking to the outside during freeze washing.

[ embodiment 2]

In embodiment 2, an indoor unit 2A is provided in consideration of the following points.

(1) If drain water or dust remains in the drain pan 17, there is a concern that water will overflow or bacteria (including mold) will be generated in the next freeze washing. Therefore, in the indoor unit 2A, the surface tension (coupling force) of the drain water is reduced by providing the concave-convex portion 130 (see fig. 11 and 12) described later in the interior of the drain pan 17, and the drain water is made to flow easily. This makes it easier for the indoor unit 2A to flow dust together with the drain water, thereby reducing the amount of dust remaining in the drain pan 17. The concave-convex portion 130 (see fig. 12) described later is not provided at a position directly in front of the inlet 23 (see fig. 12) of the drain pipe 22, and the accumulation of dust in the vicinity of the inlet 23 of the drain pipe 22 is suppressed.

(2) Since the drain water that is cold at the time of freezing cleaning flows into the inside of the drain pan 17, moisture in the air condenses to form condensed water, and the condensed water may adhere to each part of the drain pan 17 (for example, the lower surface side of the front drain pan 17F). Therefore, for example, when the condensed water adheres to the lower surface side of the front drain pan 17F, the condensed water may drip into the air outlet 13 (see fig. 2) and be scattered into the room. This causes the condensed water to leak to the outside of the indoor unit 2A. Therefore, in order to suppress the occurrence of condensation, the indoor unit 2A is provided with a heat insulator (foamed resin material) 111 (see fig. 11 and 12) described later and the like at each part of the drain pan 17. The indoor unit 2A is configured to consider the arrangement position and shape of the heat insulating material (foamed resin material) 111 and the like described later so as not to reduce the outflow rate of the drain water during drainage and not to reduce drainage efficiency.

(3) It is difficult to process the case 7 constituting the drain pan 17. Therefore, in the indoor unit 2A, when the concave-convex portion 130 (see fig. 11 and 12) described later is provided in the drain pan 17, the concave-convex portion 130 described later is provided using a separate member from the casing 7 constituting the drain pan 17. That is, in the indoor unit 2A, the rear-mentioned uneven portion 130 is provided inside the drain pan 17 by disposing the rear-mentioned heat insulating material (foamed resin material) 111 (see fig. 11 and 12) and the like in which the rear-mentioned uneven portion 130 is formed on the upper surface inside the drain pan 17.

(4) If a gap is formed between the heat exchanger 16 and the drain pan 17, an air passage for air that does not pass through the heat exchanger 16 is formed, and therefore the heat exchange efficiency of the indoor unit 2A is reduced. In addition, there is a possibility that water drops (water leaks to the outside of the indoor unit 2A) may occur in the gap. Therefore, the indoor unit 2A is configured to closely contact the heat exchanger 16 and the drain pan 17, and a gap is not formed between the heat exchanger 16 and the drain pan 17 (see fig. 16).

The structure of the indoor unit 2A according to embodiment 2 will be described below with reference to fig. 11 to 16. Fig. 11 is a perspective view of a drain pan portion of the casing 107 used in the indoor unit 2A. Fig. 12 is a partially enlarged view of the front drain pan 17F of the drain pan portion. Fig. 12 shows the structure in the vicinity of the portion a of fig. 11 in an enlarged manner. Fig. 13 is a perspective view of a heat insulator (foamed resin material) 111 used in embodiment 2. Fig. 14 and 15 are partially enlarged views of the drain portion 120 of the front drain pan 17F. Fig. 14 shows the structure of the drain part 120 after cutting along the line B-B of fig. 12. Fig. 15 shows the structure of the drain portion 120 cut along the line C-C of fig. 12 in the vicinity of the inlet 23 of the drain pipe 22. Fig. 16 is a schematic diagram showing the arrangement relationship between the heat exchanger 16F and the front drain pan 17F.

The indoor unit 2A according to embodiment 2 differs from the indoor unit 2 (see fig. 2) according to embodiment 1 in the following points.

(1) A heat insulator 111 having a projection 112 formed thereon is attached to the front surface side of the tray portion 110 of the front drain pan 17F (see fig. 11 and 12). The tray portion 110 is a flow path portion extending in the left-right direction of the front drain pan 17F.

(2) A convex portion 122 is formed in the drain portion 120 of the front drain pan 17F (see fig. 11 and 12). The drain portion 120 is a flow path portion extending in the front-rear direction (front and rear direction) of the front drain pan 17F.

(3) A heat insulator 161 (see fig. 11) having a projection 162 formed thereon is attached to the tray portion 160 of the rear drain pan 17R. The tray portion 160 is a flow path portion extending in the left-right direction of the rear drain pan 17R.

(4) The communication path 21 is provided with a projection 172 (see fig. 11).

(5) A heat insulator 211 is provided on the rear side of the drain portion 120 of the front drain pan 17F in the vicinity of the inlet 23 of the drain pipe 22 (see fig. 15).

The heat insulator 111 (see fig. 11 and 12), the heat insulator 161 (see fig. 11), and the heat insulator 211 (see fig. 15) are members attached to the casing 107A of the indoor unit 2A to suppress condensation of moisture in the air at each part of the drain pan 17 due to inflow of cold drain water into the drain pan 17 during freeze cleaning. In the indoor unit 2A, the

heat insulators

111, 161, and 211 are disposed at each part of the drain pan 17, whereby the moisture in the air is prevented from being condensed to form condensed water and from adhering to the drain pan 17.

These heat insulating

members

111, 161, 211 are made of a foamed resin material having low moisture absorption, such as foamed styrene or foamed polyurethane. In particular, the

heat insulator

111, 161 in which the flow path through which the drain water flows is formed is made of a material having low hygroscopicity, and therefore the surface thereof has water repellency. Since

such heat insulators

111 and 161 contain no water, mold generation can be suppressed. In addition, the

heat insulators

111 and 161 can easily evaporate the drain water flowing into the flow path portion. Therefore, the

thermal insulators

111, 161 can contribute to downsizing of the drain pan 17. Further, it is preferable that the flow path portion of the

heat insulator

111, 161 is preferably mirror-finished to facilitate the flow of the drain water.

Fig. 13 shows an example of the heat insulator 111. The heat insulator 111 is configured to be attachable to the drain portion 120 extending in the front-rear direction (front-rear direction) inside the front drain pan 17F. As shown in fig. 13, a convex portion 112 is formed on the upper surface of the heat insulator 111. The convex portion 112 is formed to extend in the flow direction of the drain water (extending direction of the flow path). The convex portion 112 functions as an uneven portion 130 that reduces the surface tension (bonding force) of the drain water. In the indoor unit 2A, the surface tension (bonding force) of the drain water is reduced by the convex portions 112 of the heat insulator 111, and the drain water can easily flow in a state of small-sized water droplets even if the water droplets of the drain water are bonded to each other and grow into large-sized water droplets. This makes it possible for the indoor unit 2A to facilitate the flow of dust together with the drain water, thereby reducing the amount of dust remaining in the drain pan 17.

The heat insulator 161 (see fig. 11) has the same shape as the heat insulator 111. The heat insulator 161 is configured to be attachable to the inside of the rear drain pan 17R. On the upper surface of the heat insulator 161, a convex portion 162 similar to the convex portion 112 is formed. The convex portion 162 is formed to extend in the direction in which the drain water flows (the direction in which the flow path extends).

The heat insulator 211 (see fig. 15) is configured to be attachable to a space formed below the drain portion 120 of the front drain pan 17F in the vicinity of the inlet 23 of the drain pipe 22.

A convex portion 122 is formed in the drain portion 120 of the front drain pan 17F (see fig. 11 and 12). The convex portion 122 is formed to extend in the direction in which the drain water flows (the direction in which the flow path extends). In the present embodiment, the upper surface of the convex portion 122 is formed in a substantially flat planar shape (see fig. 14). The convex portions 122 function as the concave and convex portions 130 for reducing the surface tension (coupling force) of the drain water, similarly to the convex portions 112.

The projection 122 is formed to remove a position just before the inlet 23 of the drain pipe 22 (see fig. 12). This suppresses accumulation of dust in the vicinity of the inlet 23 of the drain pipe 22 in the indoor unit 2A.

In the present embodiment, the convex portion 122 is formed directly on the case 107 constituting the front drain pan 17F. However, in the indoor unit 2A, the convex portion 122 may be formed in advance in a separate member (not shown) from the casing 107, and the convex portion 122 may be arranged in the drain portion 120 by attaching the separate member to the drain portion 120.

The bottom surface of the drain portion 122 of the front drain pan 17F is shaped to be inclined downward toward the inlet 23 side of the drain pipe 22 (see fig. 12). That is, the drain portion 122 of the front drain pan 17F has a shape in which a concave portion is formed on the bottom surface near the outlet of the flow path. This allows the indoor unit 2A to facilitate the drain water to flow in the direction of the inlet 23 of the drain pipe 22.

The communication path 21 is provided with a projection 172 (see fig. 11). The convex portion 172 is formed to extend in the direction in which the drain water flows (the direction in which the flow path extends). In the present embodiment, the convex portion 172 is formed directly on the case 107 constituting the front drain pan 17F.

As shown in fig. 16, in the present embodiment, the heat exchanger 16 (in the illustrated example, the front heat exchanger 16F) and the drain pan 17 (in the illustrated example, the front drain pan 17F) are disposed in contact with each other, and block a space between the space where the air blowing fan 14 (see fig. 2) is disposed and the space outside thereof. Thus, 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, and a gap is not formed between the heat exchanger 16 and the drain pan 17. Such an indoor unit 2A can suppress the occurrence of water droplets (water leakage to the outside of the indoor unit 2A) due to a decrease in heat exchange efficiency caused by the formation of a gap between the heat exchanger 16 and the drain pan 17.

In the indoor unit 2A, the heat exchanger 16 and the drain pan 17 are in close contact with each other, so that the condensed water adhering to the fins 20 of the heat exchanger 16 can be easily moved from the fins 20 of the heat exchanger 16 to the drain pan 17. This enables the indoor unit 2A to improve the efficiency of allowing dust adhering to the heat exchanger 16 to flow down.

< modification example >

The heat insulator (foam resin material) 111 used for the tray portion 110 of the front drain pan 17F can be deformed as shown in fig. 17 and 18, for example. Fig. 17 is a schematic view of a heat insulator (foamed resin material) 111A according to a modification. Fig. 17(a) shows a top view shape of the thermal insulator 111A, and fig. 17(b) shows a cross-sectional shape of the thermal insulator 111A. Fig. 18 is a schematic view of a heat insulator (foamed resin material) 111B of a modification, showing a plan view shape of the heat insulator 111B.

In the example shown in fig. 17(a), the heat insulator 111A is configured such that a plurality of substantially rectangular protrusions 212 are arranged at equal intervals in the vertical and horizontal directions, and recesses 213 are formed between the protrusions 212 and the protrusions 212. As shown in fig. 17(b), the recess 213 has a substantially triangular shape that widens toward the upper side. The recesses 213 are formed at equal intervals of depth h213 and width t 213.

In the heat insulator 111A, the surface tension (bonding force) of the drain water is reduced by the convex portions 212, and the drain water can easily flow in a state of small-sized water droplets even if the water droplets of the drain water are not bound to each other and grow into large-sized water droplets. Therefore, in the indoor unit 2A, the use of the heat insulator 111A makes it easy for dust to flow together with the drain water, and the amount of dust remaining in the drain pan 17 can be reduced. In addition, since the heat insulator 111A has the convex portions 212 formed in the flow path portion, the surface area is larger than that of the heat insulator 111 (see fig. 13). This allows the drain water flowing into the flow path portion to evaporate more easily in the heat insulator 111A than in the heat insulator 111 (see fig. 13).

In the example shown in fig. 18, the heat insulator 111B is different from the heat insulator 111A (see fig. 18) in that: the convex portions 212 are arranged alternately. Similarly to the heat insulator 111A, the convex portions 212 of the heat insulator 111B can reduce the surface tension (bonding force) of the drain water, and the drain water can flow easily. In addition, since the heat insulator 111B has the convex portion 212 formed in the flow path portion, similarly to the heat insulator 111A, the surface area is larger than that of the heat insulator 111 (see fig. 13). Thus, the heat insulator 111B can evaporate the drain water flowing into the flow path portion more easily than the heat insulator 111 (see fig. 13) like the heat insulator 111A.

The shape of the drain portion 120 of the front drain pan 17F may be modified as shown in fig. 19, for example. Fig. 19 is a schematic view of the drain portion 120 of the front drain pan 17F of the modification.

In the example shown in fig. 19, a plurality of (two in the example shown in the figure) convex portions 122A are formed on the bottom surface of the drain portion 120. The convex portion 122A has a substantially triangular shape whose upper width is reduced. The convex portion 122A is formed to extend in the direction in which the drain water flows (the direction in which the flow path extends). The projections 122A are formed at a depth h122A and a web t 122A. In the drain portion 120, the convex portion 122A reduces the surface tension (bonding force) of the drain water, and the drain water can flow easily.

As described above, according to the indoor unit 2A of embodiment 2, water can be prevented from leaking to the outside during freeze washing, as in the indoor unit 2 of embodiment 1. In addition, since the indoor unit 2A can facilitate the flow of the drain water, the drainage efficiency of the drain water can be improved. In addition, the indoor unit 2A can suppress the condensation of moisture in the air and the adhesion to the drain pan 17.

Description of the symbols

1-air conditioner, 2A-indoor unit, 3-outdoor unit, 5-connecting piping, 6-air intake port, 7A, 7B, 7C, 107-cabinet, 8-decorative frame, 9-front panel, 10-receiving section, 11-display section, 12-remote controller, 13-air outlet port, 14-blower fan, 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-up-down wind direction pan, 19-left-right wind direction pan, 20-fin, 21(21A, 21B) -communication passage, 22(22A, 22B) -drain pipe, 23, 123-inlet of drain pipe, 24-outlet of drain pipe, 40-pipe, 110, 160-tray section, 111A, 111B, 161, 211-heat insulating member (foam resin member), 112, 122A, 162, 172-120-outdoor unit, 130-center drain pipe, 34-center drain pipe, 1, 123-center drain pipe, 1, 21 h-center drain pipe, 21 h, 21-center drain pipe, 21A, 21B, 22A, 22B, 23, 21B, 21.

Claims

1. An indoor unit of an air conditioner, comprising:

a rear heat exchanger disposed behind the indoor unit and exchanging heat between air and a refrigerant;

a front heat exchanger disposed in front of the indoor unit and configured to exchange heat between air and a refrigerant;

a control unit for controlling a freezing operation for adhering frost or ice to the surfaces of the rear heat exchanger and the front heat exchanger,

a rear drain pan that receives drain water dripping from the rear heat exchanger;

a front drain pan for receiving drain water dropped 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; and

a drain pipe for discharging drain water stored in the front drain pan from the front drain pan to the outside of the indoor unit,

the rear drain pan, the front drain pan and the communication path form a flow path of the drain water,

the surface area x (m) of the entire heat exchanger including the rear heat exchanger and the front heat exchanger²) And the amount of water discharged from the drain pipe per unit time (m)³/s), and a value z × 10 obtained by multiplying a shorter time(s) of a time required for thawing all of the frost or ice and a time required for all of the frost or ice to fall to the front drain pan or the rear drain pan by a shorter time^-6(m³) The volume (m) of the whole drain pan combined with the rear drain pan and the front drain pan³) Is [ 2.28X 10]^-6(m)×x(m²)-z×10^-6(m³)]The above.

2. An indoor unit of an air conditioner according to claim 1,

the communication path is disposed at a position on both right and left sides of the rear drain pan or at a position near both sides thereof, and a bottom surface thereof is inclined downward from the rear drain pan side toward the front drain pan side.

3. An indoor unit of an air conditioner according to claim 1,

the communication path is disposed at a position on one side or a position near one side of the rear drain pan, and a bottom surface thereof is inclined downward from the rear drain pan side toward the front drain pan side,

the bottom surface of the rear drain pan is inclined downward from the side away from the communication path toward the side close thereto.

4. An indoor unit of an air conditioner according to claim 1,

the gravity acceleration is set as g (m/s)²) In the case of (3), the volume y of the drain pan is set to the total volume of the drain pan including the rear drain pan and the front drain pan₀(m³) The inner diameter R of the drain pipe and the depth h (m) of the front drain pan satisfy the following relation of formula (1):

[ formula 1]

5. An indoor unit of an air conditioner according to claim 1,

the bottom surface of the front drain pan is inclined downward from the side far from the inlet of the drain pipe to the side near the inlet of the drain pipe.

6. An indoor unit of an air conditioner according to claim 5,

the drain pipe is configured such that the central axis is inclined downward from the inlet toward the outlet,

the inclination angle of the central axis of the drain pipe is greater than or equal to the inclination angle of the bottom surface of the front drain pan near the inlet of the drain pipe.

7. An indoor unit of an air conditioner according to claim 1,

the opening area of the inlet of the drain pipe is larger than the cross-sectional area near the center of the drain pipe.

8. An indoor unit of an air conditioner according to any one of claims 1 to 7,

the volume of the drain pan is equal to or more than the total adhering amount of frost or ice adhered to the heat exchanger during the freezing operation.

9. An indoor unit of an air conditioner according to any one of claims 1 to 7,

the flow path has a concave-convex portion formed on the bottom surface of an arbitrary portion.

10. An indoor unit of an air conditioner according to claim 9,

the uneven portion is formed along a direction in which the flow path extends.

11. An indoor unit of an air conditioner according to claim 9,

a part of the bottom surface of the front drain pan is inclined downward from the side far away from the drain pipe to the side close to the drain pipe.

12. An indoor unit of an air conditioner according to claim 9,

a recess is formed in a bottom surface of the flow path in the vicinity of the outlet.

13. An indoor unit of an air conditioner according to claim 9,

a first heat insulating member is disposed on a rear side of a flow path portion extending in the front-rear direction of the front drain pan.

14. An indoor unit of an air conditioner according to claim 9,

a second heat insulating member is disposed on the front surface side of the flow path portion extending in the left-right direction of the front drain pan.

15. An indoor unit of an air conditioner according to claim 9,

and a blower fan disposed between the rear heat exchanger and the front heat exchanger,

the front heat exchanger and the front drain pan are disposed in contact with each other so as to block a space between a space where the blower fan is disposed and a space outside the space.