|
(11) | EP 3 088 806 A1 |
(12) | EUROPEAN PATENT APPLICATION |
published in accordance with Art. 153(4) EPC |
|
|
|
|
|||||||||||||||||||||||
(54) | INDOOR AIR CONDITIONER |
(57) To provide both surging proof stress and energy conservation properties in a wall-mounted
air-conditioning indoor machine, a stabilizer (17), a rear guider (18), and a cross-flow
fan (30) are arranged so that three expressions, (θa - θ0) > 16°, 17° < (θb - θ0) < 26°, and θb ≥ θa, are satisfied by a reference angle (θ0) formed by a fan-referencing horizontal line (L1) and a scroll-referencing line
(L2), a first angle (θa) formed by the fan-referencing horizontal line (L1) and a first straight line (SL1)
connecting a fan center point (O) and a front-surface-side closest point (P7) of the
stabilizer (17), and a second angle (θb) formed by the fan-referencing horizontal line (L1) and a second straight line (SL2)
connecting the fan center point (O) and a back-surface-side closest point (P8) of
the rear guider (18). |
TECHNICAL FIELD
BACKGROUND ART
SUMMARY OF THE INVENTION
<Technical Problem>
<Solution to Problem>
First angle relational expression: (θa - θ0) > 16°
Second angle relational expression: 17° < (θb - θ0) < 26°
Third angle relational expression: θb ≥ θa
Fourth angle relational expression: θc > θa
Fifth angle relational expression: θd < θb
<Advantageous Effects of Invention>
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is configuration drawing of an air-conditioning apparatus composed of an air-conditioning outdoor machine and an air-conditioning indoor machine.
FIG. 2 is a longitudinal cross-sectional view (a cross-sectional view along line II-II in FIG. 1) of the air-conditioning indoor machine, intended to illustrate the arrangement of the front surface panel, the filter, and the heat exchanger.
FIG. 3 is a longitudinal cross-sectional view of the air-conditioning indoor machine, intended to illustrate the arrangement of the stabilizer and the rear guider.
FIG. 4 is a graph showing the relationship between the arrangement of the stabilizer and the improvement in fan power efficiency.
FIG. 5 is a graph showing the relationship between the arrangement of the rear guider and the improvement in fan power efficiency.
DESCRIPTION OF EMBODIMENTS
(1) Configuration of Air-Conditioning Indoor Machine
(1-1) Casing
(1-2) Heat Exchanger and Filter
(1-3) Cross-Flow Fan
(2) Details of Arrangement of Front Surface Panel, Filter, and Heat Exchanger
First expression: θe > (θc × 0.4)
Second expression: D3 > D2 > D1
Third expression: D1 > (0.3 × R)
Heat exchanger bottom part angle θc = 52°
Filter bottom part angle θe = 23° > (θc × 0.4)
Fan radius R = 52 mm
First distance D1 = 16 mm > (0.3 × R)
Second distance D2 = 22 mm > D1
Third distance D3 = 27 mm > D2
Fourth expression: D4 < (3 × R)
(3) Details of Arrangement of Stabilizer and Rear Guider
First angle relational expression: (θa - θ0) > 16°
Second angle relational expression: 17° < (θb - θ0) < 26°
Third angle relational expression: θb ≥ θa
Fourth angle relational expression: θc > θa
Fifth angle relational expression: θd < θb
Reference angle θ0 = 28°
First angle θa = 48°
Second angle θb = 51°
Third angle θc = 52°
Fourth angle θd = 31 °
(4) Characteristics
(4-1) In the air-conditioning indoor machine 92 according to the present embodiment,
the stabilizer 17, the rear guider 18, and the cross-flow fan 30 are arranged not
so that any one of the first angle relational expression, the second angle relational
expression, and the third angle relational expression described above is satisfied,
but so that the first angle relational expression, the second angle relational expression,
and the third angle relational expression are all satisfied.
Because this arrangement is used, the height position of the front-surface-side closest
point P7 of the stabilizer 17 is kept low, and the air flow from the lower part 21
a of the front-surface-side heat exchange section 21 to the cross-flow fan 30 is less
inhibited. In other words, a flow of air with little loss is created from the lower
part 21a of the front-surface-side heat exchange section 21 to the cross-flow fan
30. FIG. 4 shows data to be a base of the first angle relational expression. In the
graph of FIG. 4, the horizontal axis represents the angle difference (θa - θ0), and the vertical axis represents an efficiency improvement amount, which is the
ratio of fan power, i.e., the load imposed on the motor of the cross-flow fan 30,
to a certain predetermined reference value. As a result of testing, the efficiency
improvement amount is small when the angle difference (θa - θ0) is less than 16°, and the efficiency improvement amount is large when the angle
difference exceeds 16°. When the angle difference (θa - θ0) is either 17°, 20°, 24°, or 28°, the efficiency improvement amount is large and
the increase in fan power is suppressed.
Due to the arrangement used in this air-conditioning indoor machine 92, the "fan intake
angle" (the angle on the intake port 10a side formed by the first straight line SL1
and the second straight line SL2) can be increased within a range of no more than
180°. The fan intake angle in this embodiment is as follows.
The flow of air from the cross-flow fan 30 toward the blow-out port 10b is hindered
from flowing back to the intake port 10a. In other words, surging proof stress is
improved in the air-conditioning indoor machine 92. Past air-conditioning indoor machines
often have a fan intake angle of about 170°.
Furthermore, in the air-conditioning indoor machine 92, the height position of the
back-surface-side closest point P8 of the rear guider 18 is kept to an appropriate
range, thereby suppressing the increase in fan power caused by the rear guider 18
being too low, and improving the property of energy conservation. In other words,
when the height position of the back-surface-side closest point P8 of the rear guider
18 is too low, the scroll-shaped blown air channel 10c is shorter, less force maintains
the circular vortex created on the cross-flow fan 30 side of the back-surface-side
closest point P8, and turbulent flow in the surface of the scroll-shaped blown air
channel 10c increases as does fan power, but with the arrangement of the rear guider
18 and the cross-flow fan 30 described above, this manner of increase in fan power
is suppressed. FIG. 5 shows data to be a base of the second angle relational expression.
In the graph in FIG. 5, the horizontal axis represents the angle difference (θb - θ0), and the vertical axis represents the same efficiency improvement amount as FIG.
4. As a result of testing, the efficiency improvement amount is small when the angle
difference (θb - θ0) is less than 17° or greater than 26°, and the efficiency improvement amount is
large when the angle difference is within a range of 17° to 26°. When the angle difference
(θb - θ0) is either 18°, 22°, or 25°, the efficiency improvement amount is large and the
increase in fan power is suppressed.
As described above, in the air-conditioning indoor machine 92 according to the present
embodiment, surging proof stress is improved and the increase in fan power is suppressed
by arranging the stabilizer 17, the rear guider 18, and the cross-flow fan 30 so as
to satisfy the first angle relational expression, the second angle relational expression,
the and third angle relational expression all together.
(4-2) In the air-conditioning indoor machine 92, the lower part 21 a of the front-surface-side heat exchange section 21 is arranged in a low position so that the fourth angle relational expression is satisfied, and the lower part 22a of the back-surface-side heat exchange section 22 is arranged in a low position so that the fifth angle relational expression is satisfied; therefore, the capacity of the heat exchanger 20 increases. Particularly, a greater capacity of the heat exchanger 20 than those in the past is ensured because the third angle θc is at least 45° and the air-conditioning indoor machine 92 employs a structure in which the lower part 21a of the front-surface-side heat exchange section 21 is extended downward. When the air-conditioning indoor machine is equipped with this large heat exchanger 20, the distribution of the air flow through the heat exchanger is partially imbalanced, the air flow is inhibited, and fan power tends to be high, but because the air-conditioning indoor machine 92 employs a component arrangement that satisfies the first angle relational expression, the second angle relational expression, and the third angle relational expression all together as described above, the air flow from the lower parts 21a, 22a of the heat exchanger 20 to the cross-flow fan 30 is not readily inhibited, and air flows in large quantities to the lower parts 21a, 22a of the heat exchange sections 21, 22 as well. In other words, the property of energy conservation of the air-conditioning indoor machine 92 is improved.
(4-3) The air-conditioning indoor machine 92 employs a structure in which indoor air
is drawn in through the intake port 10a formed in the ceiling of the casing 10, which
is in a higher position than the fan center point O, and also employs a structure
in which the lower part 21 a of the front-surface-side heat exchange section 21 and
the lower part 40a of the filter 40 are both positioned lower than the fan center
point O. Therefore, when past design methods are followed, less air passes through
the lower part 21 a of the front-surface-side heat exchange section 21, and the entire
heat exchanger 20 can no longer be effectively utilized.
In view of this, in the air-conditioning indoor machine 92, the lower part 40a of
the filter 40 is first extended downward to a lower position than in the past so as
to satisfy the first expression described above, and a channel is ensured for air
to flow through the lower part 40a of the filter 40 toward the lower part 21a of the
front-surface-side heat exchange section 21.
Furthermore, in the air-conditioning indoor machine 92, the cross-flow fan 30, the
heat exchanger 20, the filter 40, and the front surface panel 15 are arranged so that
the three gap distances D1, D2, and D3 satisfy the second expression described above,
and while the depth dimension of the air-conditioning indoor machine 92 is kept small,
there is little pressure loss in the channel for air flowing through the gap between
the filter 40 and the front surface panel 15 (of which the gap distance is the third
distance D3), from the intake port 10a to the lower part 40a of the filter 40 and
the lower part 21a of the front-surface-side heat exchange section 21. A sufficient
quantity of air passing through the lower part 21 a of the front-surface-side heat
exchange section 21 is thereby ensured, and a structure is achieved in which the entire
heat exchanger 20 is effectively utilized.
Employing an arrangement such as that described above makes it possible in the air-conditioning
indoor machine 92 to extend the width of the air channel leading to the lower part
21a of the front-surface-side heat exchange section 21 and to keep friction resistance
(pressure loss) low, without making the gap distance (the first distance D1) between
the heat exchanger 20 and the cross-flow fan 30 too small. The second distance D2
is greater than the first distance D1, the third distance D3 is greater than the second
distance D2, and the width is ensured to increase as the channel gets further away
from the cross-flow fan 30; therefore, there is no longer a space where the width
becomes small in the path from the intake port 10a to the lower part 21a of the front-surface-side
heat exchange section 21 as shown in FIG. 2, and fluid friction resistance is greatly
reduced in comparison with past structures.
(4-4) The air-conditioning indoor machine 92 employs a component arrangement that
satisfies the second expression in order to keep the depth dimension (the dimension
in the left-right direction in FIG. 2) small, but when the first distance D1 is too
small, the front-surface-side heat exchange section 21 and the cross-flow fan 30 are
too close together, and there may be sounds when air passes through the front-surface-side
heat exchange section 21. Particularly, in the air-conditioning indoor machine 92
which employs a fin-and-tube type heat exchanger 20 of which the tube outside diameter
is small (5 mm or 4 mm), there are fluctuations with strong turbulence at higher frequencies
among periodic flow rate fluctuations typified by Karman vortexes, and there is a
high risk of discrete frequency sounds at high frequencies due to interaction with
the periodic pressure fluctuation of the fan blades 31.
To keep these sounds to a minimum, the air-conditioning indoor machine 92 employs
a component arrangement that satisfies the third expression described above. In other
words, the first distance D1, which is the gap distance between the cross-flow fan
30 and the front-surface-side heat exchange section 21 at the same height position
as the fan center point O, is made to be greater than 30% of the fan radius R, whereby
the sounds are kept to an allowable range. If this size is ensured for the first distance
D1 of the air-conditioning indoor machine 92, the air flow that has passed through
the heat exchanger 20 can be changed to a non-periodic wide-range turbulent flow structure
and then made to collide with the fan blades 31, and the periodic sounds caused by
the interaction with the fan blades 31 can be reduced.
(4-5) In the air-conditioning indoor machine 92, the front surface panel 15 is arranged so as to satisfy the fourth expression described above, and the distance from the fan center point O to the front surface panel 15 (the fourth distance D4) is comparatively small. A thin air-conditioning indoor machine 92 with a minimized depth dimension is thereby achieved, but because a structure is employed which simultaneously satisfies the first through third expressions, the entire heat exchanger 20 can be effectively utilized even if the machine has a thin profile.
REFERENCE SIGNS LIST
CITATION LIST
PATENT LITERATURE
a cross-flow fan (30), for generating an air flow, the cross-flow fan having a plurality of blades (31) aligned along a circumference;
a casing (10) including a stabilizer (17) on the front-surface side and a rear guider (18) on the back-surface side, the stabilizer (17) being divided into a top part (72) and a bottom part (73) with a tongue part (71) in between, a blown air channel (10c) having a scroll shape through which air flows from the cross-flow fan to a blow-out port (10b) being formed in the casing (10) by the stabilizer and the rear guider; and
a heat exchanger (20) including a front-surface-side heat exchange section (21) and a back-surface-side heat exchange section (22), the heat exchanger (20) arranged on the airflow-upstream side of the cross-flow fan;
in a longitudinal cross-sectional view:a horizontal line through a fan center point (O), which is the rotational center of the cross-flow fan, being a fan-referencing horizontal line (L1);
a line designated as a scroll-referencing line (L2) being a straight line that, of any straight line tangent to a circle (30a) connecting the outer ends of the plurality of fan blades of the cross-flow fan and adjoining the bottom part of the stabilizer, forms the smallest angle with the fan-referencing horizontal line;
the angle formed by the fan-referencing horizontal line and the scroll-referencing line being a reference angle θ0;
an angle designated as a first angle θa being the angle formed by the fan-referencing horizontal line (L1) and a first straight line (SL1), which is a straight line connecting the fan center point and a front-surface-side closest point (P7) which is the point on the top part of the stabilizer that is closest to the cross-flow fan;
an angle designated as a second angle θb being the angle formed by the fan-referencing horizontal line (L1) and a second straight line (SL2), which is a straight line connecting the fan center point and a back-surface-side closest point (P8) which is the point on the rear guider that is closest to the cross-flow fan; and
the stabilizer, the rear guider, and the cross-flow fan being arranged so as to satisfya first angle relational expression: (θa - θ0) > 16°,
a second angle relational expression: 17° < (θb - θ0) < 26°, and
a third angle relational expression: θb ≥ θa.
a lower part (21a) of the front-surface-side heat exchange section is positioned lower than the fan-referencing horizontal line (L1);
a lower part (22a) of the back-surface-side heat exchange section is positioned higher than the fan-referencing horizontal line (L1);
a line designated as a third straight line (SL3) is a straight line that, of any straight line passing through the fan center point and the lower part of the front-surface-side heat exchange section, forms the largest angle with the fan-referencing horizontal line (L1);
the angle formed by the third straight line and the fan-referencing horizontal line is a third angle θc;
a line designated as a fourth straight line (SL4) is a straight line that, of any straight line passing through the fan center point and the lower part of the back-surface-side heat exchange section, forms the smallest angle with the fan-referencing horizontal line;
the angle formed by the fourth straight line and the fan-referencing horizontal line is a fourth angle θd; and
the stabilizer, the rear guider, the heat exchanger, and the cross-flow fan are arranged so as to satisfy
a fourth angle relational expression: θc > θa, and
a fifth angle relational expression: θd < θb.
REFERENCES CITED IN THE DESCRIPTION
Patent documents cited in the description