JP3262027B2 - Indoor unit and air conditioner using the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air conditioner such as a ceiling-mounted cassette type and an indoor unit thereof, and more particularly, to the protection of the global environment, there is no danger of depletion of the ozone layer, It is suitable for those with little condensation.

[0002]

2. Description of the Related Art As a measure for environmental protection of an air conditioner, it is required that the ozone layer is not destroyed, and an alternative chlorofluorocarbon-free chlorofluorocarbon, specifically, an HFC-based refrigerant (R40) is used.
7C) is being considered for use. However, in order to consider the environment, it is necessary not only to use an HFC-based refrigerant but also to reduce noise and dew as adverse effects on the surrounding environment.

[0003] In particular, with regard to noise, a plurality of heat insulating materials cut in a predetermined shape in advance are adhered to a steel plate case of a cabinet accommodating a blower fan and a heat exchanger of an indoor unit. I have.

It is also known that a heat insulating resin material such as foamed polyethylene is formed in advance and integrally molded, and then incorporated in a cabinet formed of a steel plate into a box shape.
No. 431.

[0005]

In the above-mentioned conventional technology, the heat-insulating material to which the heat-insulating material is adhered is not only high in material and processing costs such as cutting and coating, but also difficult to recycle in view of environmental protection. There is a problem.

Further, those using foamed polyethylene or styrofoam as a heat insulating material inside the cabinet have low sound absorption performance, and are not sufficient to reduce the wind noise of a blower fan during operation or the ventilation sound of a heat exchanger. There is a problem that adversely affects the surrounding environment.

Further, an alternative chlorofluorocarbon-free chlorofluorocarbon, HF
When a C-based refrigerant (R407C) is used, the efficiency of heat exchange decreases, and the temperature of components such as a heat exchanger rises. In this case, there is a problem in that a gap is generated between the components due to the separation of the steel plate and the heat insulating material of the cabinet and the temperature difference, the occurrence of rubbing noise, and the deterioration of the heat insulating performance due to the penetration of dew condensation water.

Further, when an HFC-based refrigerant is used, the heat exchange efficiency of the heat exchanger is reduced, so that it is necessary to increase the rotation speed of the blower fan to increase the air volume. There is.

An object of the present invention is to solve the above problems and to provide an indoor unit suitable for environmental protection, recycling, and little influence on the surrounding environment, and an air conditioner using the same. The present invention provides at least one of the above objects.
Is to solve one.

[0010]

In order to achieve the above object, the present invention provides a suction grill provided at the center of a panel.
And a centrifugal blower fan, and
A box-shaped cabinet containing the placed heat exchanger,
Air conditioner having air outlets provided on four sides of the outer periphery
In the indoor unit of
The case is made of steel and the side and ceiling of the case
Foam on the inner surface of the
The inner insulation and the case side and ceiling
Polyurethane on the outer surface of the part forms a skin layer on the outer surface
External insulation foamed on the surface and integrally molded
Material and dimensions so that the inner insulation can be compressed and incorporated
And a finished panel. As a result,
The inside of the side and ceiling of the base is made of soft polyurethane
Because it foams, it can increase the sound absorption coefficient while being a heat insulating material,
Parts such as heat exchangers become hot,
Even if the air volume is increased, the noise is sufficiently reduced
Adverse effects on the environment can be avoided. Also, the inner insulation is
Since it is compressed and incorporated into the panel,
No gap due to peeling or temperature difference, no peeling, no rubbing
Prevents deterioration of insulation performance due to penetration of raw and dew water
You. In addition, the outer surface has an outer heat insulating skin on the outer surface.
It is foamed on the surface so that a layer is formed,
Surface strength and prevent condensation water from entering.
You. As described above, the heat exchange efficiency of the HFC-based refrigerant decreases.
Even if the air volume is increased by using it, the increase in noise is prevented, and the insulation performance is improved.
Can be secured. Therefore, suitable for environmental protection and recycling,
The influence on the surrounding environment can be reduced.

Further, the present invention is the one described above, the inner
The foaming condition of the surface insulation material is the liquid ratio (polyol / isocyanate).
G) is 100/28, the mold temperature is about 60 ° C.
The foaming condition of the outer heat insulating material is the liquid ratio (polyol / isocyanate
100) and mold temperature around 40 ° C.
Is desirable.

[0012]

Further, the present invention provides an outdoor unit and a panel.
Suction grill at the center of the
And the heat exchangers arranged all around the blower fan.
A box-shaped cabinet that has been stored, and
Refrigeration connected to an indoor unit having a closed outlet
In an air conditioner with a cycle, the cabinet
A case made of steel plate, which is composed and incorporates panels, and a case
The inside of the side and ceiling is made of soft polyurethane
Inner insulation material foamed on the surface and integrally molded, and case
Polyurethane on the outside of the sides and ceiling of the
Foamed on the surface so that an aqueous skin layer is formed
Compression of the outer insulation material and the inner insulation material
Panels dimensioned to be incorporated
HFC refrigerant that circulates the freezing cycle
The number of rotations was increased to increase the air volume.

Since an alternative chlorofluorocarbon-free HFC-based refrigerant (R407C) circulates through the refrigeration cycle, there is no danger that the ozone layer will be destroyed due to leakage of the refrigerant during recycling such as installation and decomposition. Further, even when the HFC-based refrigerant is used in the refrigeration cycle, it is possible to avoid the peeling of the heat insulating material of the cabinet, the generation of rubbing noise due to the gap, the infiltration of dew condensation water, and the increase in noise due to an increase in air volume.

[0015] Further, in the above, the heat exchanger
R407C refrigerant flows through the inner heat insulator and outer heat insulator
Is desirably 4 to 20 mm.

[0016]

[0017]

A cabinet is arranged in a box shape so as to surround the blower fan and the heat exchanger, and has a thickness of 4 to 20 mm.
Since the foamed polymer heat insulating material is closely attached to the inner or outer surface of the box, noise can be reduced without impairing downsizing of the indoor unit. Therefore, R407C is used as a refrigerant.
Since it is used, it can be made particularly suitable for recycling.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is an exploded perspective view showing an indoor unit of a ceiling embedded cassette type in a separate type air conditioner, FIG. 2 is a sectional view of the indoor unit, FIG. Is a perspective view showing the structure of the cabinet, and FIG. 5 is a characteristic diagram showing the reverberation sound absorption coefficient of the heat insulating material provided in the cabinet.

The main body of the indoor unit is installed from a ceiling (not shown) via hanging bolts 13 and hanging brackets 14 by means of hanging bolts 15. This indoor unit has a cabinet 4 embedded in the ceiling, a decorative panel 9 installed substantially flush with the ceiling surface 8, a suction grill 10 in the center of the decorative panel 9, and four sides in the outer peripheral portion. Each of the air outlets 11 is provided. Reference numeral 5 denotes a centrifugal blower fan made of synthetic resin having a single suction and called a turbo fan.
Is a motor mounted on the top plate of the cabinet 4 to rotationally drive the blower fan 6, 12 is a drain pan formed in an annular shape, and 7 is disposed in a discharge-side ventilation passage through which air is discharged from the blower fan 5 in all circumferential directions. It is an annular heat exchanger.

When the blower fan 5 is rotated and operated, the room air sucked into the blower fan 5 from the suction grill 10 is discharged from the blower fan 5 in all circumferential directions, and the discharged air is guided to the heat exchanger 7. Then, it is cooled or heated and blown out from blowout ports 11 provided in four directions. During the operation of the air conditioner, the rotation noise of the motor 6 and the wind noise of the blower fan 5 and the ventilation noise in the heat exchanger 7 are generated, reflected on the inner wall surface of the cabinet 4 and reflected on the outlet 11 and the suction grill 10.
It is emitted as more noise. The cabinet is mainly composed of a case 1 and a heat insulating material, in which a steel plate is generally used for the purpose of, for example, preventing the spread of fire at the time of ignition and maintaining the rigidity.

Conventionally, the heat insulating material is bonded and attached to the case 1 for the purpose of preventing dew condensation on the surface of the steel sheet case due to the air discharged during the cooling operation. Therefore, the temperature of the heat exchanger 7 and the like becomes high during the heating operation, and the temperature of the case 1 made of steel plate becomes high.
The heat insulating material is easily peeled off from the case 1, and a temperature difference with other low-temperature unit component parts such as an air suction port and a water receiver is generated.
A rubbing sound is generated by vibrations caused by the operation of the blower fan or the like.

The configuration of the cabinet 4 according to the embodiment will be described in detail. The case 1 made of a steel plate of the cabinet 4 is formed by foaming an inner heat insulating material 2 and an outer heat insulating material 3 on the inner surface and the outer surface of the cabinet 1 with a continuous and unified material on the surface of the case 1 using polyurethane. The inner heat insulating material 2 and the outer heat insulating material 3 are made of soft or polyurethane having continuous cells and a case 1.
Is molded in a mold.

The polyurethane can have a soft property of continuous bubbles by setting the liquid ratio of the polyol as a raw material liquid to the isocyanate to 2: 1 or more. The wind noise of the blower fan 5 and the ventilation sound of the heat exchanger 7 during operation are 1kHz to 4k.
It is noise generated at about Hz. On the other hand, from the reverberation sound absorption coefficient characteristics of each heat insulating material in FIG. 5, the sound absorption coefficient of the styrene foam in this band is about 0 to 0.2, and the sound absorption coefficient of the urethane foam that has been pasted is about 0.2 to 0.8. On the other hand, the sound absorption coefficient of soft urethane foam is 0.2 to 1, which is improved to about 5 times as compared with that of polystyrene foam.

Further, polyurethane has a higher adhesive strength than polystyrene foam, and the inner heat insulating material 2 and the outer heat insulating material 3 are fixed to the case 1 with high adhesive strength by foaming the foam on the surface of the case 1. No need to apply. The adhesive strength to the case 1 is as high as about 1 kg / cm ^{2 according to} the test method described in JIS A-9526, paragraph 3-9, and is formed as a continuous and integral body.

During the heating operation, the temperature of the heat exchanger 7 and the like becomes high, so that the temperature of the steel plate of the case 1 becomes high. Since the dimensions of the panel 9 and the drain pan 12 are set so that the cabinet 2 is compressed and incorporated, it is possible to add flexibility that a gap does not occur even if the dimensions of the cabinet 7 change due to thermal expansion.

The outer heat insulating material 3 forms a thick waterproof waterproof skin layer on the outer surface of the polyurethane portion by a method called polyurethane integral foam so that the skin portion becomes thicker. Therefore, the surface strength can be improved, and breakage damage due to impact or the like at the time of transportation, installation work, or the like, and intrusion of moisture from the broken portion can be prevented. In particular, since the flexible foamed polyurethane has a structure having continuous cells, there is a possibility that the dewed water may seep and the heat insulating performance may be reduced, but this can prevent the dewed water from entering.

The polyurethane integral foam has an arbitrary thickness by adjusting the foaming conditions such that the liquid ratio of the polyol as the raw material liquid to the isocyanate is close to 2: 1 and the mold temperature is different from the mold temperature by about 40 ° C. Can be obtained. The inner heat insulating material 2 and the outer heat insulating material 3 are made of polyurethane integral foam and have a skin layer thickness of 0.1 to 2 with respect to a foamed polyurethane thickness of about 4 to 20 mm.
mm. On the other hand, the skin layer obtained by general foaming is 0.1 mm or less. Here, if the thickness of the foamed polyurethane (foamed polymer insulating material) is smaller than 4 mm, the sound absorption is insufficient, and if the thickness is 20 mm or more, the miniaturization of the indoor unit is impaired.

In the foam molding, the molds for molding the inner and outer heat insulating materials are held in the case 1 and the material of the foamed polymer heat insulating material is injected and molded. In particular, by using a soft polyurethane as the inner heat insulating material 2, excellent sound absorbing characteristics can be obtained. The foaming conditions of the inner heat insulator 2 and the outer heat insulator 3 are as follows. In the case of the inner heat insulating material 2, the liquid ratio (polyol / isocyanate) is 100/28 and the liquid temperature is 25.
° C, mold temperature 60 ° C, apparent density 0.058g / c
As m ³ , it is preferable to use a material having excellent sound absorption characteristics. In the case of the outer heat insulating material 3, the liquid ratio is 100/48, the liquid temperature is 25 ° C., the mold temperature is 40 ° C., and the apparent density is 0.160 g.
/ Cm ³ , it is desirable to have excellent moldability and dimensional stability. Here, the thickness of the outer heat insulating material 3 and the thickness of the skin layer are determined in consideration of external water absorption prevention and deterioration of appearance due to handling, etc., and the inner heat insulating material 2 has sound absorbing performance, heat resistance. Therefore, it is desirable that the thickness of the skin layer and the thickness of the skin layer be different from those of the outer heat insulating material 3.

Further, the indoor unit comprises a heat exchanger 7,
That is, the refrigerant circulating in the refrigeration cycle is replaced by HFC-based refrigerant (R407C), which does not contain chlorine, and the airflow of the blower fan is increased to improve the heat exchange performance. In other words, in the case of using a heat exchanger having a capacity equivalent to that of the R22 refrigerant, the capacity of the HFC-based refrigerant decreases when the heat exchanger having the same capacity as that of the R22 refrigerant is used, but in order to compensate for this, the rotation speeds of the blower fan 5 and the motor 6 are increased. The heat exchange efficiency is improved by increasing the air volume. At this time, the cabinet 4 in which the foamed polymer heat insulating material is integrally formed is arranged so as to surround the heat exchanger 7 so as to prevent the noise leaking out of the indoor unit from increasing, thereby suppressing an increase in the noise.

As described above, there is no danger that the refrigerant leaks and the ozone layer is destroyed even during recycling such as installation and disassembly, and the inner heat insulating material 2 and the outer heat insulating material 3 of the cabinet 4 are used while using the HFC-based refrigerant. The generation of rubbing noise due to peeling and gaps, the infiltration of dew condensation water, and the increase in noise due to the increase in air volume are avoided, and the effect on the surrounding environment is reduced.

[0032]

In the indoor unit according to the present invention, since the foamed urethane which is a heat insulating material and has a high sound absorption coefficient is integrally formed with the cabinet, the HFC which reduces the heat exchange efficiency is obtained.
Even if a system refrigerant is used, noise can be reduced to avoid adverse effects on the surrounding environment, and an indoor unit suitable for environmental protection and recycling can be obtained.

Further, the air conditioner according to the present invention has an HF
Since the C-based refrigerant circulates through the refrigeration cycle and the cabinet is integrally molded with foamed polymer insulation, there is no risk of destroying the ozone layer even if the refrigerant leaks even during recycling such as installation and disassembly. Avoid the occurrence of rubbing noise generated in the area, the penetration of dew condensation water, and the increase in noise,
An air conditioner suitable for environmental protection and recycling and an indoor unit used for the air conditioner can be obtained.

Further, the present invention provides a heat exchanger having R407.
Since the C refrigerant flows, the blower fan and the heat exchanger are formed in a box shape from a steel plate, and the polymer heat insulating material is surrounded by a cabinet closely adhered to the inner or outer surface of the box shape. Even if the temperature of the fan becomes high and the number of rotations of the blower fan is increased, noise can be sufficiently reduced, and an indoor unit suitable for environmental protection and recycling and having little influence on the surrounding environment can be obtained.

Further, according to the present invention, R407C
Is used, and a foamed polymer heat insulating material having a thickness of 4 to 20 mm is adhered to the inner or outer surface of the cabinet, so that the indoor unit can be reduced in size to reduce noise and obtain an indoor unit particularly suitable for recycling. Can be.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view showing an indoor unit of a ceiling embedded cassette type according to an embodiment.

FIG. 2 is a cross-sectional view showing an indoor unit of a ceiling embedded cassette type according to one embodiment.

FIG. 3 is an enlarged sectional view of a part of FIG. 2;

FIG. 4 is a perspective view showing the structure of the cabinet of the indoor unit of the ceiling embedded cassette type according to the embodiment.

FIG. 5 is a characteristic diagram showing a comparison between reverberation sound absorption coefficients of a heat insulating material provided in a cabinet.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Case, 2 ... Inner heat insulating material, 3 ... External heat insulating material, 4 ... Cabinet, 5 ... Ventilation fan, 6 ... Motor, 7 ... Heat exchanger, 8 ... Ceiling surface, 9 ... Panel, 10 ... Suction grill, 11 … Outlet, 12… Drain pan, 13… Hanging fixture fixing bolt, 14…
Hanging brackets, 15 ... hanging bolts.

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Kingo Moriyama 390 Muramatsu, Shimizu-shi, Shizuoka Prefecture Air Conditioning Systems Division, Hitachi, Ltd. (56) References JP-A-7-167458 (JP, A) JP-A-8 JP-136064 (JP, A) JP-A-8-145489 (JP, A) JP-A-7-239132 (JP, A) JP-A-6-66431 (JP, A) JP-A-56-68736 (JP, A) JP-A-7-190517 (JP, A) JP-A-61-175817 (JP, U) JP-A-4-110319 (JP, U) JP-A-6-2018 (JP, U) JP-A 103515 (JP, U) Japanese Utility Model 2-81318 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) F24F 1/00 F24F 5/00

Claims (4)

(57) [Claims] 1. A suction grill provided in the center of a panel ,
A centrifugal fan and a fan arranged all around the fan
A box-shaped cabinet and has a storage heat exchanger, the outer periphery
In an indoor unit of an air conditioner having an outlet provided on four sides of a section, a steel constituting the cabinet and incorporating the panel is provided.
A plate-shaped case, and soft polyurethane on the inner surface of the side and ceiling of the case.
Inner insulation material foamed on the surface so as to be integrally molded
And polyurethane on the outer surface of the side and ceiling of the case.
Foamed on the surface so that a skin layer is formed on the outer surface
The external heat insulating material is integrally molded and has dimensions such that the internal heat insulating material can be compressed and incorporated.
Indoor units, comprising the, said panels. 2. The method according to claim 1, wherein said inner surface is formed.
The foaming condition of the heat insulating material is the liquid ratio (polyol / isocyanate).
G) is 100/28, the mold temperature is about 60 ° C.
The foaming condition of the outer heat insulating material is the liquid ratio (polyol / isocyanate
Over G) to 100/48, the indoor unit, wherein the this <br/> that the mold temperature of about 40 ° C.. 3. An outdoor unit and a panel provided at the center of the panel.
Suction grille, centrifugal blower fan, and blower fan
A box-shaped casing containing heat exchangers arranged in all directions
Has a vignette and outlets provided on the four sides of the outer periphery
In the air conditioner and the indoor unit is provided with a connected refrigeration cycle that, steel the panel constitutes the cabinet is incorporated
A plate-shaped case, and soft polyurethane on the inner surface of the side and ceiling of the case.
Inner insulation material foamed on the surface so as to be integrally molded
And polyurethane on the outer surface of the side and ceiling of the case.
On the surface so that a waterproof skin layer is formed on the outer surface
An outer heat insulating material which is foamed and integrally molded with a material having a size such that the inner heat insulating material is compressed and incorporated.
And a said panels, and HFC refrigerant circulating in the refrigeration cycle, the air conditioner being characterized in that increased air volume by increasing the rotational speed of the blower fan. 4. The method according to claim 1, wherein the heat exchange
R407C refrigerant flows through the heat exchanger, and the inner heat insulating material and
The indoor unit, wherein the thickness of the outer heat insulating material is 4 to 20 mm .