EP2719970A2

EP2719970A2 - Indoor unit of air conditioner

Info

Publication number: EP2719970A2
Application number: EP13186579.2A
Authority: EP
Inventors: Kunihiro Hashiura; Yasuhiro Naito; Hironori Mori
Original assignee: Mitsubishi Heavy Industries Ltd
Current assignee: Mitsubishi Heavy Industries Thermal Systems Ltd
Priority date: 2012-10-11
Filing date: 2013-09-30
Publication date: 2014-04-16
Also published as: JP6112540B2; EP2719970A3; JP2014077591A

Abstract

The indoor unit (1) of an air conditioner includes a unit body (2) equipped with an indoor heat exchanger (4,4A,4B) and an indoor fan (5) therein; and at least one drain pan (6) disposed under the indoor heat exchanger, wherein the drain pan is provided with a foam thermal insulation member (19) integrally formed with an inner surface of the drain pan, a seat (20) on which the lower end of the indoor heat exchanger (4A) is placed is formed on the inner surface of the foam thermal insulation member, and an air shield wall (21) having a predetermined height for covering the front portion of the lower end portion of the indoor heat exchanger is uprightly disposed at a front of the seat.

Description

Technical Field

The present invention relates to an indoor unit of an air conditioner in which drain pans each having a thermal insulation structure are provided under an indoor heat exchanger.

Background Art

In an indoor unit of an air conditioner, there is provided under an indoor heat exchanger with a drain pan for collecting drain water generated from dew-condensed moisture in the air on a surface of an indoor heat exchanger in cooling or humidifying operation, and for draining collected water outside the room. The drain pan is cooled by drain water dropping from the indoor heat exchanger, so that dew-condensation is caused on a surface of the drain pan when the surrounding air comes in contact with the surface of the drain pan, and the dew-condensed water may drop down to the room. Hence, the drain pan has a thermal insulation structure in which a thermal insulation member is installed.
The insulating member is installed on an outer surface of the drain pan in some cases, and on an inner surface thereof in other cases, and other component members constituting an air outlet port and the like are often integrally formed on the outer surface of the drain pan, which makes it significantly difficult to install the insulating member on the outer surface, so that the thermal insulation member should be divided into some pieces to be installed. Furthermore, on the inner surface of the drain pan, it is necessary to insert an insulation material (cushion material) in a gap between a lower end of the indoor heat exchanger and the drain pan in order to block air flow through the gap, so as to prevent a bypass of the air flow.
Meanwhile, to address problems of difficulty in installation of the thermal insulation member, and increase in number of man-hour, Patent Literature 1 provides such a drain pan whose inner surface is provided with a thermal insulation member integrally made of a foam thermal insulation member.

Citation List

Patent Literature

{PTL 1} Japanese Unexamined Patent Application, Publication No. 2006-300431

Summary of Invention

Technical Problem

According to Patent Literature 1 set forth above, it is possible to reduce the number of the thermal insulation members as well as the number of man-hours for installing the thermal insulation members. Accordingly, effects such as attaining reduction in cost can be expected, but simply installing the integrally formed foam thermal insulation member on the inner surface of the drain pan cannot completely block the air flow flowing through the gap between the lower end of the indoor heat exchanger and the foam thermal insulation member, and the air flow may bypass through the gap.
Specifically, a warp in the width direction is accepted on the manufacturing basis among the indoor heat exchanger, the drain pan, the integrally formed foam thermal insulation member, and others, and there is such a problem that the bypass of the air flow cannot be prevented as far as a gap generated by the acceptable warp is shielded, or the air flow flowing through this gap is blocked.
An object of the present invention, which has been made in order to solve the problems according to the conventional art, is to provide an indoor unit of an air conditioner including a drain pan provided with a foam thermal insulation member integrally formed with an inner surface of the drain pan, capable of reducing the number of thermal insulation members and the number of man-hours for installing the thermal insulation members, as well as capable of preventing a bypass of air flow at a lower end of an indoor heat exchanger. Solution to Problem
An indoor unit of an air conditioner according to the present invention includes a unit body equipped with an indoor heat exchanger and an indoor fan therein; and at least one drain pan disposed under the indoor heat exchanger, wherein the drain pan is provided with a foam thermal insulation member integrally formed with an inner surface of the drain pan, a seat on which a lower end of the indoor heat exchanger is placed is formed on the inner surface of the foam thermal insulation member, and an air shield wall having a predetermined height for covering a front of the lower end portion of the indoor heat exchanger is uprightly disposed at a front of the seat.
Through this configuration, even in the configuration of providing the integrally formed foam thermal insulation member on the inner surface of the drain pan, the gap generated with a warp acceptable in the manufacturing of the foam thermal insulation member and the lower end of the indoor heat exchanger can be covered by the air shield wall uprightly disposed at the front of the seat on which the lower end of the indoor heat exchanger is placed, thereby blocking the air flow flowing through this gap. Accordingly, it is possible to prevent the bypass of the air flow at the lower end portion of the indoor heat exchanger. In addition, thermal insulation members to be installed on the drain pan are limited to the foam thermal insulation member integrally formed with the inner surface of the drain pan, and thus it is possible to reduce the number and amount of the thermal insulation members to be used as well as the number of man-hours for installing the thermal insulation members.
In the above indoor unit of an air conditioner, the air shield wall may be extendedly disposed along the front of the lower end portion of the indoor heat exchanger across an entire width of the lower end portion of the indoor heat exchanger.
Through this configuration, it is possible to attain an air shielding effect for the gap generated with the above warp across the entire width of the lower end portion of the indoor heat exchanger. Accordingly, it is possible to securely prevent the bypass of the air flow at the lower end portion of the indoor heat exchanger.
In any one of the above indoor units of an air conditioner, the air shield wall is of a sufficient height to absorb a widthways warp, tolerable in the manufacturing of the indoor heat exchanger, the drain pan, the foam thermal insulation member, as well as at least to cover a gap generated by the warp.
Through this configuration, for example, if the widthways warp tolerable in the manufacturing (that is the warp due to tolerances in the manufacturing process, for example) of the indoor heat exchanger, the drain pan, and the foam thermal insulation member is assumed to be 1 mm, the height of the air shield wall is sufficiently higher than the warp, for example, 3 mm, thereby completely blocking the air flow likely to be generated through the gap due to the warp, thereby preventing air from passing.
In any one of the above indoor units of an air conditioner, the seat may have a thickness dimension to accept only a part of a front half of a thickness dimension in an air flow direction of the indoor heat exchange.
Through this configuration, it is possible to reduce as much as possible the amount of the foam thermal insulation member required for forming the seat and the air shield wall that are provided for blocking the air flow flowing between the foam thermal insulation member disposed on the inner surface of the drain pan and the lower end of the indoor heat exchanger by reducing the thickness dimension of the seat. Accordingly, it is possible to reduce the amount of the foam thermal insulation member to be used as much as possible, thereby saving the cost.

Advantageous Effects of Invention

According to the present invention, even in the configuration of providing the foam thermal insulation member integrally formed with the inner surface of the drain pan, the gap generated with warp acceptable in the manufacturing of the foam thermal insulation member and the lower end of the indoor heat exchanger can be covered by the air shield wall uprightly disposed at the front of the seat on which the lower end of the indoor heat exchanger is placed, thereby blocking the air flow flowing through this gap. Accordingly, it is possible to prevent the bypass of the air flow at the lower end portion of the indoor heat exchange, and thermal insulation members to be installed on the drain pan are limited to the foam thermal insulation member integrally formed with the inner surface of the drain pan; thus it is possible to reduce the number and amount of the thermal insulation members to be used as well as the number of man-hours for installing the thermal insulation members.

Brief Description of Drawings

{Fig. 1}
Fig. 1 is a front view of an indoor unit of an air conditioner according to one embodiment of the present invention with a front cover assembly of the indoor unit removed;
{Fig. 2}
Fig. 2 is a perspective view of the indoor unit of an air conditioner illustrated in Fig. 1 viewed from the right front of the indoor unit;
{Fig. 3}
Fig. 3 is a longitudinal section view showing the vicinity of a central portion of the indoor unit of an air conditioner illustrated in Fig. 1; and
{Fig. 4}
Fig. 4 is a partial enlarged view of the lower end portion of the indoor heat exchanger and the drain pan in Fig. 3.

Description of Embodiments

With reference to Fig. 1 to Fig. 4, description will be provided on one embodiment of the present invention, hereinafter.
Fig. 1 shows a front view showing an indoor unit of an air conditioner according to one embodiment of the present invention with a front cover assembly of the indoor unit removed, Fig. 2 is a perspective view thereof, Fig. 3 is a longitudinal section view showing the vicinity of a central portion of the indoor unit, and Fig. 4 is a partial enlarged view thereof.
The indoor unit 1 of an air conditioner includes a unit body 2 including a base 3 and a front cover assembly (not shown) detachably assembled at the front of the base 3.
As shown in Fig. 3, inside the unit body 2, an indoor heat exchanger 4 folded or divided in an approximate A (lambda) shape extending along the front face, the upper face, and the rear face of the unit body 2; an indoor fan 5 constituted by a cross flow fan horizontally disposed downstream of the indoor heat exchanger 4; a motor (not shown) for rotationally driving the indoor fan 5; an air outlet assembly 9 with which a drain pan 6 disposed at the lower front of the indoor heat exchanger 4 is integrally formed, and in which a louver 7 and a flap 8 for adjusting air flow direction are integrally incorporated; a control box 10, and others are assembled and disposed to the base 3 in a conventional manner.
In addition, the front cover assembly is assembled to the base 3 so as to cover the upper face, the front face, and the right and left faces of the above component members assembled to the base 3. This front cover assembly is provided with a suction grille for sucking room air into the unit body 2, and an air filter is disposed on the rear face of the grille, and further, a filter cleaning mechanism and the like for self-cleaning the air filter may be optionally disposed.
The indoor heat exchanger 4 is configured to be a plate fin and tube type heat exchanger, and air shield plates 11, 12 for blocking a bypass of air flow are disposed at the folded or divided portions of the indoor heat exchanger 4. The plate fin and tube type heat exchanger is usually configured in such a manner that multiple plate fins 13 are installed between right and left side plates of hair pin tubes, and thereafter each hair pin tube is expanded in diameter so as to allow the tube, the fin, and the side plates to tightly contact to one another, and opening ends of every two adjacent hair pin tubes are connected to each other through a U bent pipe 14, thereby forming a serpentine piping passage; and the heat exchanger piping 15 including the U bent pipes 14 and the bent portions of the hair pin tubes outwardly projects from the right and left side plates at the end portion of the heat exchanger.
A low pressure coolant flows through the indoor heat exchanger 4 when the indoor unit 1 equipped with the indoor heat exchanger 4 is in cooling or dehumidifying operation. Hence, moisture in the air becomes due-condensed on the surface of the plate fins 13, the surface of the heat exchanger piping 15 outwardly projecting from the end portion of the indoor heat exchanger 4, or the surface of others and then becomes water drops to drop down. If such water drops drop down on equipment below, and splashes to the surroundings, this may bring about various inconveniences. On the right side of the indoor heat exchanger 4 where the control box 10 is disposed, such water drops may cause disturbances on electric systems, or water leakage to the room, etc.; therefore, the front of the heat exchanger piping 15, that is, the front of the right end portion of the indoor heat exchanger 4 is covered with a pipe cover 16.
Meanwhile, of the water drops dew-condensed on the surface of the indoor heat exchanger 4, water drops generated on an indoor heat exchanger 4A forwardly disposed flow down along the surface of the plate fins 13, and are collected in the drain pan 6 disposed below. Water drops generated on an indoor heat exchanger 4B backwardly disposed flow down along the surface of the plate fins 13, and are collected in a backside drain pan 17 disposed on the base 3. And then the drain water collected in these drain pans 6, 17 is discharged outside the room through a drain hose (not shown).
Dew-condensed water at a low temperature is collected in the drain pans 6, 17. Consequently, if the surrounding air comes in contact with the outer surfaces of the drain pans 6, 17, there is a risk of generating dew-condensation, so that each of the drain pans 6, 17 should have a thermal insulation structure. The outer surface of the backside drain pan 17 has such a simple structure that a thermal insulation member 18 is installed on the outer surface of the drain pan 17 so as to obtain the thermal insulation structure. On the other hand, the drain pan 6 forwardly disposed is integrally formed with component members of an air outlet port as the air outlet assembly 9, and has such a complicated outer surface structure that it is difficult to install the thermal insulation member thereon.
Therefore the drain pan 6 is provided with a foam thermal insulation member 19 integrally formed with its inner surface using open-cell foam of resin non-permeable to water, such as polypropylene (PP) and polystyrene (PS). Furthermore, as shown in Fig. 3 and Fig. 4, in order to prevent a bypass of the air flow through a gap between the foam thermal insulation member 19 and the lower end of the indoor heat exchanger 4 (4A), that is, a gap likely generated with a warp in the width direction acceptable in the manufacturing of the indoor heat exchanger 4, the drain pan 6, the integrally formed foam thermal insulation member 19, and others, there is provided a seat 20 on which the lower end portion of the indoor heat exchanger 4 (4A) is placed, and an air shield wall 21 having a predetermined height for covering the front of the lower end portion of the heat exchanger is uprightly disposed at the front of the seat 20.
The air shield wall 21 is extendedly disposed along the front of the lower end portion of the indoor heat exchanger 4 (4A) across the entire width of this lower end portion of the indoor heat exchanger 4. The air shield wall 21 is configured to have such a height dimension from the upper surface of the seat 20 that is an enough height H to absorb the warp in the width direction acceptable in the manufacturing of the indoor heat exchanger 4, the drain pan 6, and the foam thermal insulation member 19, and at least to cover the gap generated with the warp. For example, if the warp in the width direction acceptable in the manufacturing of the indoor heat exchanger 4, the drain pan 6, and the foam thermal insulation member 19 is assumed to be 1 mm, it is sufficient to define the height H of the air shield wall 21 from the upper surface of the seat 20 to be more than 1 mm, that is, 3 mm, for example.
In addition, it is unnecessary to place the entire lower end of the indoor heat exchanger 4(4A) on the seat 20, and only a part of a front half thickness of the lower end of the indoor heat exchanger 4, that is, a part of a front half of a thickness W1 in the air flow direction of the indoor heat exchanger 4 may be placed on the seat 20. Hence, it is sufficient just only to define a thickness W2 in the air flow direction of the seat 20 to be approximately 1/2 to 1/3 of the thickness dimension W1 in the air flow direction of the indoor heat exchanger 4.
Through the aforementioned configuration, the present embodiment attains the following advantageous effects.
When the air conditioner is in cooling or dehumidifying operation, the indoor heat exchanger 4 in the indoor unit 1 functions as an evaporator. Through this function, the room air circulating through the indoor fan 5 can be cooled and dehumidified, and the cooled and dehumidified air is allowed to blow into the room, thereby cooling and dehumidifying the room air. At this time, in the indoor heat exchanger 4 through which the low pressure coolant flows, moisture in the air becomes dew-condensed on the surface of the plate fins 13 and others, and then becomes water drops to drop down along the surface of the plate fins 13. The water drops are collected in the drain pans 6, 17 respectively, and discharged outside the room through the drain hose.
Then the drain pans 6, 17 have their insulation structures with the foam thermal insulation member 19 integrally formed with the inner surface of the drain pan 6, and with the thermal insulation member 18 installed on the outer surface of the drain pan 17, respectively; therefore, even if the surrounding air comes in contact with the drain pans 6, 17, there is no risk of generating dew condensation on the outer surfaces of these drain pans.
On the other hand, since the drain pan 6 has such an insulation structure that the foam thermal insulation member 19 is integrally formed with the inner surface of the drain pan 6, it is unnecessary to install plural divided pieces of the thermal insulation member on the outer surface of the drain pan 6 having a complicated structure because the outer surface of the drain pan 6 is integrally formed with the component members of the air outlet port, and thermal insulation members to be installed on the drain pan 6 can be limited to the foam thermal insulation member 19 integrally formed with the inner surface of the drain pan 6. Accordingly, it is possible to reduce the number and amount of the thermal insulation members to be used as well as the number of man-hours for installing the thermal insulation members, thereby attaining reduction in cost.
In addition, the seat 20 on which the lower end of the indoor heat exchanger 4 (4A) is placed is formed on the inner surface of the foam thermal insulation member 19, and the air shield wall 21 having the predetermined height H that covers the front of the lower end portion of the indoor heat exchanger 4 (4A) is further uprightly disposed at the front of the seat 20. Through this configuration, the gap, which is generated with the warp acceptable in the manufacturing of the indoor heat exchanger 4, the drain pan 6, the foam thermal insulation member 19 and others, between the foam thermal insulation member 19 and the lower end of the indoor heat exchanger 4 (4A) can be covered by the air shield wall 21 uprightly disposed at the front of the seat 20 on which the lower end of the indoor heat exchanger 4 (4A) is placed, thereby blocking the air flow flowing through this gap. Accordingly, it is possible to securely prevent the bypass of the air flow at the lower end portion of the indoor heat exchanger 4.
Moreover, the air shield wall 21 is extendedly disposed along the front of the lower end portion of the indoor heat exchanger 4 across the entire width of this lower end portion of the indoor heat exchanger 4; thus it is possible to attain the air shielding effect for the gap generated with the above warp across the entire width of this lower end portion of the indoor heat exchanger 4. Accordingly, it is possible to securely prevent the bypass of the air flow at the lower end portion of the indoor heat exchanger 4.
Furthermore, as aforementioned, in the present embodiment, the air shield wall 21 is configured to have an enough height dimension to absorb the warp in the width direction acceptable in the manufacturing of the indoor heat exchanger 4, the drain pan 6, and the foam thermal insulation member 19, and at least to cover the gap generated with the warp. For example, if the warp in the width direction acceptable in the manufacturing of the indoor heat exchanger 4, the drain pan 6, and the foam thermal insulation member 19 is assumed to be 1 mm, the height H of the air shield wall 21 is sufficiently higher than the warp, that is, 3 mm, for example, thereby completely blocking the air flow flowing through the gap likely generated with the warp. Accordingly, it is possible to securely attain the air shielding effect for the gap generated with the warp, thereby preventing the bypass of the air flow.
In the present embodiment, the seat 20 on which the lower end of the indoor heat exchanger 4 (4A) is placed is configured to have the thickness dimension W2 to accept only a part of the front half of the thickness dimension W1 in the air flow direction of the indoor heat exchanger 4. Through this configuration, it is possible to reduce as much as possible the amount of the foam thermal insulation member 19 required for forming the seat 20 and the air shield wall 21 that are provided for blocking the air flow flowing between the foam thermal insulation member 19 disposed on the inner surface of the drain pan 6 and the lower end of the indoor heat exchanger 4 (4A) by narrowing the thickness dimension W2 of the seat 20. Accordingly, it is possible to reduce the amount of the foam thermal insulation member 19 to be used as much as possible, thereby saving costs.
While the present invention is not limited to the aforementioned embodiment, various modifications may be made without departing from the scope of the present invention. For example, the aforementioned embodiment has been described by using an example of the drain pan 6 integrally formed with the air outlet assembly 9, but the present invention is applicable to the drain pan 6 having a standalone structure, of course. The present invention may also be applicable not only to the drain pan 6, but also to the backside drain pan 17 in the same manner. In addition, the aforementioned embodiment has been described by using an example of the indoor heat exchanger 4 folded or divided in the A shape, but the present invention may also be applicable to the indoor heat exchanger in a plane shape, of course.
Furthermore, the foam thermal insulation member 19 is not limited to that in the aforementioned embodiment as far as it is made of a foam resin material which is non-permeable to water. In addition, the seat 20 and the air shield wall 21 may be appropriately altered in shape, dimension, and others as far as the basic functions thereof described in the aforementioned embodiment are maintained.

Reference Signs List

1: Indoor unit
2: Unit body
4, 4A, 4B: Indoor heat exchanger
5: Indoor fan
6: Drain pan
19: Foam thermal insulation member
20: Seat
21: Air shield wall
H: Height of air shield wall
W1: Thickness in the air flow direction of indoor heat exchanger
W2: Thickness in the air flow direction of seat

Claims

An indoor unit of an air conditioner comprising:
a unit body (2) equipped with an indoor heat exchanger (4,4A,4B) and an indoor fan (5) therein; and

at least one drain pan (6) disposed under the indoor heat exchanger,

characterized in that

the drain pan (6) is provided with a foam thermal insulation member (19) integrally formed with an inner surface of the drain pan,

a seat (20) on which a lower end of the indoor heat exchanger (4A) is placed is formed on the inner surface of the foam thermal insulation member (19), and

an air shield wall (21) having a predetermined height for covering a front of the lower end portion of the indoor heat exchanger (4A) is uprightly disposed at a front of the seat (25).
The indoor unit of an air conditioner according to claim 1, wherein
the air shield wall (21) is extendedly disposed along the front of the lower end portion of the indoor heat exchanger (4A) across an entire width of the lower end portion of the indoor heat exchanger.
The indoor unit of an air conditioner according to claim 1 or claim 2, wherein
the air shield wall (21) is of a sufficient height to absorb a widthways warp, tolerable in manufacturing an indoor heat exchanger (4,4A,4B), the drain pan (6), and the foam thermal insulation member (19), as well as at least to cover a gap generated by this warp.
The indoor unit of an air conditioner according to any one of claim 1 to claim 3, wherein
the seat (20) has a thickness dimension to accept only a part of a front half of a thickness dimension in an air flow direction of the indoor heat exchanger (4,4A,4B).