| Title of Invention | INTEGRATED TYPE AIR CONDITIONER |
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| Abstract | In an integrated type air conditioner wherein air suction port is formed in a room-side front face of the unit and air blow-out ports are formed on both sides of the air suction port, when the blow-out ports are narrowed, the air blow-out velocity increases, with consequent increase of pressure and noise, while when the blow-out port s are widened, the width of a heat exchanger becomes narrow and the cycle capacity is deteriorated. To avoid this problem, the width of the heat exchanger to the unit width in the integrated type air conditioner is set at a value in the range of 0.6 to 0.75. |
| Full Text | FIELD OF THE INVENTION The present invention relates to an integrated type air conditioner. BACKGROUND OF THE INVENTION On a room interior side of a conventional integrated type air conditioner, an interior heat exchanger is disposed centrally of a front face of the unit and a centrifugal fan such as Sirocco fan or turbofan is disposed downstream of the interior heat exchanger, and blow-out ports are disposed on both sides of the interior heat exchanger. More particularly, as described in Patent Literatures 1 and 2, an air suction port is disposed on the front side of the integrated type air conditioner so as to be opposed to the interior heat exchanger, and air sucked in from the air suction port is sucked into the centrifugal fan through the interior heat exchanger, then passes through an air path, and is blown out from air blow-out ports formed on both sides of the air suction port. [Patent Literature 1] Japanese Utility Model Laid-Open No. S53(1978)-157549 [Patent Literature 2] Japanese Patent Laid-Open No. Hll(1999)-325505 SUMMARY OF THE INVENTION In the above conventional integrated type air conditioner, despite the unit width cannot be made large and is originally narrow, a square air suction port is disposed on a front side when seen from the interior of a room and vertically long, rectangular air blow-out ports are disposed on the right and left sides of the air suction port. Therefore, in order to obtain a predetermined air volume for ensuring a required heat exchange quantity, it has been necessary to use a high-pressure fan (Sirocco fan) because the pressure loss of the heat exchanger is larger. As a result, there arise problems. For example, the noise of the fan is high and the input of a fan motor is high, with consequent increase of unit power consumption and deteriorated COP (coefficient of output performance = capacity/electric input). This is for the following reason. As a room fan there is used a multiblade fan of a large inside diameter wherein blades capable of outputting high air volume and high pressure are inclined largely in a rotational direction, so that the blow-out speed at a fan outlet is high and the loss at blow-out ports becomes large. The blow-out ports disposed on both sides of the front face of the unit cannot be made small. Consequently, the width of the interior heat exchanger cannot be made large inevitably. This problem has led to further problems. For example. since the air blow-out speed in the blow-out ports is low, cold air does not spread throughout the whole of the room, with consequent unevenness in room temperature and prolonged time until reaching a predetermined temperature. More particularly, when the width of the interior heat exchanger is increased in order to improve the heat exchanging performance of the interior heat exchanger, the width of each air blow-out port is reduced, resulting in an increase of noise, while when the width of each air blow-out port is increased for the purpose of reducing noise, the width of the interior heat exchanger becomes smaller, with consequent deterioration of its heat exchanging performance. It is an object of the present invention to provide an integrated type air conditioner having an air suction port formed in a front face of the unit and air blow-out ports formed on the right and left sides of the air suction port, the air conditioner being capable of reducing noise and attaining a satisfactory heat exchanging performance which are antagonistic phenomena. The above object is achieved by an integrated type air conditioner comprising a compressor installed within a unit, an exterior heat exchanger, an interior heat exchanger, an exterior fan, an air suction port formed in a front face of the unit, and air blow-out ports formed on the right and left sides by the air suction port, wherein the interior heat exchanger is disposed in opposition to the air suction port and has U bends at both ends thereof and also has fins at the portion located between the U bends, and the ratio of the width of the fin portion of the interior heat exchanger to the width of the unit is in the range of 0.60 to 0.75. The above object is also achieved by an integrated type air conditioner comprising a compressor installed within the unit, an exterior heat exchanger, an interior heat exchanger, an exterior fan, an air suction port formed in a front face of the unit, and air blow-out ports formed on the right and left sides by the air suction port, wherein the interior heat exchanger is disposed in opposition to the air suction port and has U bends at both ends thereof and also has fins at the portion located between the U bends, and the ratio of the overall width of the interior heat exchanger to the width of the unit is in the range of 0.70 to 0.85. According to the present invention it is possible to provide an integrated type air conditioner comprising an air suction port formed in a front face of a unit and air blow-out ports formed on the right and left sides of the air suction port, the air conditioner permitting both reduction of noise and the attainment of a satisfactory heat exchanging performance. BREIF DESCRIPTION OF THE DRAWINGS FIG. 1 is a sectional plan view of an integrated type air conditioner according to an embodiment of the present invention; FIG. 2 is a front view thereof; FIG. 3 is a diagram showing a relation between the width of an interior fan and COP; and FIG. 4 is a diagram showing a modification of air blow-out ports in the integrated type air conditioner. DETAILED DESCRIPTION OF A PREFERRED EMBODIEMNT FIG. 1 shows an integrated type air conditioner according to an embodiment of the present invention. The numeral 1 denotes a unit base on which components of the integrated type air conditioner are mounted. Those components are covered with a cabinet 2. An exterior partition wall 6 serves as a partition between a discharge space and a suction space, and a mouth ring 3 for exterior use is provided as a suction port in the exterior partition wall 6. The discharge space is enclosed with the exterior partition wall 6 and an exterior heat exchanger 5, and air fed from an exterior fan 4 disposed downstream of the mouth ring 3 is discharged to the discharge space. A compressor 8, a suction tank 7, and a fan motor 11 for driving the exterior fan 4 and an interior fan 12 through two shafts, are disposed upstream of the exterior fan 4. The fan motor 11 is fixed to the unit base 1 through a fan motor support base 10. When the exterior fan 4 rotates, air is sucked into the air conditioner from a room in which the compressor 8 is installed, then passes through the exterior heat exchanger 5 installed downstream of the exterior fan 4, whereby heat is released to the exterior of the room. A front grille 19, a filter 15 and an interior heat exchanger 21 are disposed on the room side of an interior/ exterior partition wall 9. A suction casing 20 is provided which also serves as apart of an interior casing 17 for conducting air from the interior heat exchanger 21 to the interior fan 12. Air sucked in from the interior mouth ring 13 enters the interior fan 12 and the flow of air from the fan 12 is divided to both sides of the unit by noses 22. Further, lateral wind direction adjusting plates 16 and vertical wind direction adjusting plates 18 are mounted downstream of the noses 22. Upon rotation of the interior fan, air is sucked in through the front grille 19 and the filter 15, absorbs heat in the interior heat exchanger 21, then is divided by the plural noses 22 and the interior casing 17 which determine a blow-out air flow on the downstream side of the fan, and cold air is discharged to the interior of the room from blow-out ports 14 disposed on both sides of the interior heat exchanger 21. The interior heat exchanger 21 comprises a central fin portion which mainly performs heat exchange, a refrigerant flowing pipe, and U-bend portions 23 for return of the pipe on both sides of the fin portion. The width of the fin portion is assumed to be Wexf and the overall width of both fin portion and U bend portions is assumed to be Wex. In the integrated type air conditioner, air sucked in from the air suction port formed in the front face on the room side is heat-exchanged through the width Wexf of the fin portion out of the overall width Wex of the interior heat exchanger 21 and is sucked into the interior fan 12. The thus-conditioned air is blown of f into the room from the blow-out ports 14 formed on both outer sides of the interior heat exchanger 21 and on both sides of the air suction port which is formed in the front face of the unit. Though not shown, a drain pan for receiving condensate and a water conduit for conducting water from the drain pan to an exterior lower portion of the unit 1 are provided under the interior heat exchanger 21. As described above, the interior heat exchanger is made up of fins, a pipe which is in close contact with the fins, and both-end U bends for multi-return of the pipe. Thus, the fin portion sandwiched in between the both-end U bends substantially functions as a heat exchange portion, while the U bend portions at both ends scarcely contribute to heat exchange in comparison with the fin portion. In many integrated type air conditioners, the unit width is 470 mm to 660 mm (depending on cooling capacity) , the width of the fin portion in the interior heat exchanger is 270 mm in the former, 375 mm in the latter. and the ratio of a substantial heat exchanging portion to the unit width is about 0.57. The overall width of the interior heat exchanger as a total of the width of the fin portion and the total length of both-side U bends was about 330 mm in the former, 435 mm in the latter, (0.7 to 0.66 as the ratio to the unit width). This value has been determined taking into account the demand for ensuring a sufficient heat exchange quantity by increasing the front mounting area of the interior heat exchanger and the fear of eventual increase of noise and of power consumption caused by an increase of fan input which are attributable to an increase of the front area of the heat exchanger in the width direction with consequent narrowing of blow-out ports on the both sides of the unit and consequent rapid increase of the blow-out speed leading to a greater increase of fan pressure than necessary. However, this structure has involved the following problems. Despite the original small unit width, the front area of the fin portion in the interior heat exchanger is as small as 0 . 57 as referred to above, so that when a predetermined air volume for ensuring a required heat exchange quantity is provided, a large pressure loss of the heat exchanger results and therefore it is inevitably required to use a high-pressure fan (Sirocco fan). As a result, there arise the problem that the noise of the fan is loud and the problem that the input of the fan motor is high, with consequent increase in power consumption of the unit and deterioration of COP. FIG. 2 is a front view of the air conditioner of this embodiment, showing the unit width Wu versus the widths Wexf and Wex of the heat exchanger, an outlet width Bd of each blow-out port and the vertical direction of the unit. In this embodiment, an electric part 24 for operating the unit is disposed in the lower portion of the unit. The unit is formed in a rectangular shape having a width Wu and a height Hu. Likewise, the heat exchanger is formed in a rectangular shape having widths Wexf, Wex and a height Hex, and each blow-out port is formed in a rectangular shape having a width Bd and a height Hd. Therefore, it is necessary that the balance between the pressure loss of the heat exchanger and the pressure loss (dynamic pressure for blow-out of air) of the blow-out ports be determined taking characteristics of the fan into account. That is, when the widths Wexf and Wex of the interior heat exchanger 21 are set large to increase the heat exchange quantity, the blow-out speed of air from the blow-out ports 14 increases and a dynamic pressure thereof increases rapidly, with the result that a higher pressure than the pressure rising level of the fan is needed and hence air does not flow. When the outlet width Bd of each blow-out port 14 is increased for decreasing the dynamic pressure of the blow-out port 14 and for diminishing the loss of each wind direction adjusting plate 18, the width of the interior heat exchanger 21 becomes smaller, thus giving rise to the problem that not only the pressure loss of the heat exchanger increases but also it is impossible to ensure the required heat exchange quantity. Moreover, for ensuring a sufficient air volume it is necessary to increase the number of revolutions of the fan, which leads to a great increase of noise and hence to a rapid increase of the fan motor input, with consequent increase of power consumption. This is undesirable from the standpoint of power saving. That is , in the integrated type air conditioner, an optimum value which permits maximizing the air volume and maximizing the heat exchange quantity is present between the width Wexf or Wex of the interior heat exchanger 21 and the blow-out port width. FIG. 3 shows an effect obtained in this embodiment, more particularly, shows how the energy consumption efficiency (generally called COP) relative to the unit capacity is changed by varying fin portion widths (Wexf) relative to the unit width (Wu) and by consequent changes in air volume while adopting a conventional value as unit noise (the values described in the figure are of 1. 5 HP and higher models , assuming the capacity to be constant) . More particularly, the numerical values were calculated by experiment and simulation. The conventional maximum value of the fin portion width in the heat exchanger is about Wexf/Wu =0.57 and COP at this point is shown as COP = 1.0. As the fan there is used a centrifugal fan (turbofan) which is lower in absolute speed of the impeller outlet (impeller outlet angle is approximately within |32 = 130) in comparison with Sirocco fan. Consequently, the capacity is improved to a great extent at a heat exchanger width of Wexf/Wu = 0.60 or more which is larger than the conventional maximum value, and lowers rapidly at a Wexf/Wu value of 0.75 or more. The reason for such a rapid drop in capacity at Wexf/Wu of 0.75 or more is that the blow-out ports become relatively narrow with an increase of Wexf/Wu and a consequent increase of the blown-off air velocity leads to an increase of dynamic pressure and of loss at the wind direction adjusting plates. Theoretically, at Wexf/Wu = 1.0, there is neither blow-out area nor air volume, so that COP becomes equal to zero. When the Wexf/Wu value is small, there occur a decrease of the heat transfer area of the heat exchanger and a sudden increase of pressure loss of the heat exchanger, with consequent deterioration of capacity and a great increase of the fan motor input. At Wexf = 0 , the air volume becomes zero, thus resulting in COP becoming zero. From the above it is seen that, for ensuring a larger value than the conventional COP ratio of 1, the fin portion width (Wexf) of the heat exchanger relative to the unit width (Wu) should be in the range of Wexf/Wu = 0.60 to 0.75. In the air conditioner, it is important to improve 1% or more of COP. Besides, since the improvement of COP being considered is based on only the fan performance and the state of mounting of the heat exchanger, the above results which do not lead to a large increase of cost are important for power saving. In this sense, an optimum Wexf/Wu value permitting 1% or more improvement of COP relative to the value available at present may be set at 0.625 to 0.7. Further, it may be considered that an ultimate optimum value is in the range from 0.65 to 0.7. Since the above effects can be obtained on the basis of only the heat transfer area of the heat exchanger and the air volume of the fan under a constant noise level, any factor leading to a great increase of cost is constituted and it is possible to shorten the period for development. Thus, in the integrated type air conditioner, setting the fin portion width (Wexf) of the heat exchanger to a value in the range of 0.60 to 0.75 relative to the unit width or to a value in such a more suitable range as described above is advantageous in the aspect of noise and the aspect of unit cycle efficiency. Further, since the blow-out port width (Bd) can be made smaller than in the prior art, the blown-off air velocity increases and cold air spreads throughout the whole of the room. with consequent improvement of comfortableness. In the integrated type air conditioner of this embodiment, as described above, since the mounting width of the heat exchanger within the limited unit width is made 10% or more larger than in the prior art by optimization in relation to the dynamic pressure at the outlet of each blow-out port, it is possible to attain a high air volume under the same noise level condition to increase the interior heat exchange quantity and thereby possible to decrease the power consumption to a low level. Further, by narrowing the outlet width of each blow-out port as a result of the above, the air blow-out velocity is increased to let cold air spread throughout the whole of the room and the room temperature can be brought to a predetermined level after the start of operation. As a result, it is possible to prevent the occurrence of unevenness in temperature throughout the whole of the room. Thus, the optimum value of the fin portion width (Wexf) in the heat exchanger has been shown above, but in the actual heat exchanger, as shown in FIG. 1, the U bend pipe portions 23 are located on both sides of the fin portion and the U bends scarcely exhibit any heat exchanging effect, but are important portions for mounting the heat exchanger. The blow-out port width (Bd) depends on the fin portion width (Wexf) plus the width (Bd) of the U bends on both sides. According to the foregoing actual numerical values, the U bend width is about 22% to 16% of the find portion width (Wexf) , 13% to 9% of the unit width. Consequently, an optimum value of the overall heat exchanger width (Wex) is Wex/Wu = 0.70 to 0.85, which is a little higher than the above optimum value. It follows that, when the axis of abscissa in FIG. 3 is considered as the overall heat exchanger width, the width ratio which permits a more improvement of the heat exchange quantity than in the conventional range can be considered as Wex/Wu = 0.70 to 0.85. Also as to the optimum value of the overall heat exchanger width including the U bends, it is apparent that there exists an optimum range affording a higher energy consumption efficiency (COP) as in the optimum value of the fin portion width (Wexf) in the heat exchanger. By setting the heat exchanger width relative to the unit width at a value falling under the optimum range, the air velocity of the blow-out ports increases, whereby the room temperature distribution can be made uniform and it is possible to shorten the time required for reaching a predetermined temperature. This embodiment is for further enhancing this effect. According to the conventional structure, blow-out ports are located on the front side of the unit and cold air is blown off to the front side of the unit. On the other hand, according to a modification of blow-out ports shown in FIG. 4, blow-out ports 14 are enlarged sideways of the unit. With a swing motion of wind direction adjusting plates 18, cold air is blown off along both side faces of the unit. When the blow-out ports 14 are thus enlarged along both side faces of the unit, the air velocity in the blow-out ports 14 is mitigated and the capacity can be improved by a still further increase of air volume. Since the front decorative frame portion is curved, it is preferable that the size (Dd) of the enlargement be set at 20% or more of the blow-out port width (Bd). As a result, the following effect is obtained in connection with the room temperature distribution. When the blow-out ports are enlarged sideways of the unit and cold air is blown off along both side faces through wind direction adjusting plates , the whole or walls of the room can be cooled with cold air without increase of loss at the wind direction adjusting plates because the blow-out ports are larger than in the prior art, whereby a panel cooling effect is created in a steady state. A description will now be given about the shape of the interior fan 12 with reference to FIG. 1. In the interior fan 12, the outside diameter of a shroud 26 is smaller than the inside diameter of a hub 25, and the outside diameter of each blade 24 is made smaller gradually from the hub 25 side toward the shroud 26. A fan motor input can be decreased by 10% or more in comparison with the case where the diameter of the blade 2 4 is constant axially. By adopting this mounting form of the interior heat exchanger and example of blow-out ports , the energy consumption efficiency (COP) shown in FIG. 3 is further improved. Although reference has been made to the integrated type air conditioner having blow-out ports on both right and left sides of the interior heat exchanger, the same effects as above can also be obtained even when there are other blow-out ports than those both-side blow-out ports. Thus, according to the above embodiment, since the heat exchanger mounting area can be set to a maximum within the limited unit width, it is possible to decrease the power consumption, increase the air volume and consequent improvement of cool feeling, assuming that the capacity is constant. Moreover, since the fan motor input decreases, it is possible to minimize the consumption of resources and reduce the cost and weight. WHAT IS CLAIMED IS: 1. An integrated type air conditioner comprising a compressor installed within the unit, an exterior heat exchanger, an interior heat exchanger, an exterior fan, an interior fan, an air suction port formed in a front face of the unit, and air blow-out ports formed on the right and left sides by the air suction port, wherein the interior heat exchanger is disposed in opposition to the air suction port and has U bends at both ends thereof and also has fins at the portion located between the U bends, and the ratio of the width of the fin portion of the interior heat exchanger to the width of the unit is in the range of 0.60 to 0.75. 2. The integrated type air conditioner according to claim 1, wherein the air blow-out ports are enlarged sideways of the unit. 3. An integrated type air conditioner comprising a compressor installed within the unit, an exterior heat exchanger, an interior heat exchanger, an exterior fan, an interior fan, an air suction port formed in a front face of the unit, and air blow-out ports formed on the right and left sides by the air suction port, wherein the interior heat exchanger is disposed in opposition to the air suction port and has U bends at both ends thereof and also has fins at the portion located between the U bends, and the ratio of the overall width of the interior heat exchanger to the width of the unit is in the range of 0.70 to 0.85. 4. The integrated type air conditioner according to claim 3, wherein the air blow-out ports are enlarged sideways of the unit. In an integrated type air conditioner wherein air suction port is formed in a room-side front face of the unit and air blow-out ports are formed on both sides of the air suction port, when the blow-out ports are narrowed, the air blow-out velocity increases, with consequent increase of pressure and noise, while when the blow-out port s are widened, the width of a heat exchanger becomes narrow and the cycle capacity is deteriorated. To avoid this problem, the width of the heat exchanger to the unit width in the integrated type air conditioner is set at a value in the range of 0.6 to 0.75. |
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| Patent Number | 271016 | ||||||||||||||||||
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| Indian Patent Application Number | 131/KOL/2005 | ||||||||||||||||||
| PG Journal Number | 06/2016 | ||||||||||||||||||
| Publication Date | 05-Feb-2016 | ||||||||||||||||||
| Grant Date | 29-Jan-2016 | ||||||||||||||||||
| Date of Filing | 25-Feb-2005 | ||||||||||||||||||
| Name of Patentee | HITACHI APPLIANCES, INC. | ||||||||||||||||||
| Applicant Address | 16-1,KAIGAN 1-CHOME MINATO-KU,TOKYO | ||||||||||||||||||
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| PCT International Classification Number | F24F 1/02 | ||||||||||||||||||
| PCT International Application Number | N/A | ||||||||||||||||||
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