JP4995308B2 - Air conditioner indoor unit - Google Patents

Description

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

  A heat exchanger and a fan are essential elements of an air conditioner. In an indoor unit of a separate type air conditioner, a crossflow fan is usually used as a fan for circulating indoor air. The heat exchanger disposed on the upstream side of the crossflow fan is often a plurality of heat exchangers that cover the crossflow fan so as to surround the crossflow fan. Examples of the indoor unit of an air conditioner having such a configuration can be seen in Patent Documents 1 and 2.

  Patent Document 1 discloses a plurality of fins arranged in parallel along the airflow direction, a plurality of heat transfer tube groups arranged in a direction orthogonal to the fins and in which a refrigerant flows, and ends of the heat transfer tube groups. Describes an indoor unit of an air conditioner in which a plurality of heat exchangers each having a first header and a second header connected to each part are arranged so as to surround a cross flow fan.

  Patent Document 2 discloses an air conditioner in which a fin-and-tube heat exchanger is divided into three in the horizontal direction, and is folded in three so that the upper two surfaces are inverted V-shaped, and a crossflow fan is disposed therein. An indoor unit is described.

  When the heat exchanger is used as an evaporator, moisture in the atmosphere condenses on the surface of the heat exchanger that has become a low temperature, and condensed water is generated. When the temperature is low, the condensed water turns into frost on the surface of the heat exchanger. Frost can travel to ice. In the present specification, the term “condensed water” is used to include water in which such frost and ice are melted, so-called defrosted water.

  In an indoor unit of a type in which a cross flow fan is surrounded by a heat exchanger, such as an indoor unit of an air conditioner described in Patent Document 1 and Patent Document 2, consideration is given to preventing condensed water from dripping onto the cross flow fan. Necessary. If it drips, water droplets will be blown out together with the air current. If it hits the user, the user will feel uncomfortable, and if it hits the furniture etc., they will get wet.

  When the heat exchanger is a parallel flow type heat exchanger, if the condensed water stays on the surface of the flat tube or corrugated fin, the cross-sectional area of the air flow passage is narrowed by the water, and the heat exchange performance is reduced. There is also a problem. Condensed water retention is a problem particularly in a side flow parallel flow heat exchanger.

  Patent Documents 3 and 4 propose measures for promoting drainage from a side flow parallel flow heat exchanger. In the heat exchanger described in Patent Document 3, each flat section of a plurality of tubes is inclined with respect to the horizontal direction in which the outside air flows. In the heat exchanger described in Patent Document 4, flat heat transfer tubes arranged in a two-row multiple-stage zigzag pattern are arranged so as to be inclined with respect to the main flow direction of the gas.

JP 2005-265263 A Japanese Utility Model Publication No. 4-69921 JP 2004-69228 A JP 2007-183088 A

  Air conditioner indoor units are often equipped with fin-and-tube heat exchangers.

  The present invention improves the performance of an air conditioner by installing a parallel flow heat exchanger having higher heat exchange efficiency in an indoor unit than a fin-and-tube heat exchanger, and is generated by a parallel flow heat exchanger. Condensed water is applied to the fan so that water drops are not blown out along with the air current.

According to a preferred embodiment of the present invention, an indoor unit of an air conditioner includes a cross flow fan that circulates indoor air, and a heat exchange unit that is disposed upstream of the cross flow fan, and the heat exchange unit includes: A plurality of parallel flow heat exchangers that are arranged above the cross flow fan and that form a roof shape whose upper ends are close to each other, and each of the plurality of parallel flow heat exchangers is a side flow system. A plurality of flat tubes extending left and right when viewed from the front , corrugated fins are disposed between the flat tubes, and the flat tubes are high in the front-rear direction and close to the cross flow fan, and vice versa. It has a slope that becomes lower on the side.

According to a preferred embodiment of the present invention, in the indoor unit of the air conditioner configured as described above, the end of the corrugated fin that is far from the cross flow fan is protruded from the end of the flat tube, and A linear water guide member was inserted into the gap formed, and the distance between the water guide member and the protruding end of the corrugated fin positioned thereon was a distance at which the surface tension of water could work.

  According to a preferred embodiment of the present invention, in the indoor unit for an air conditioner configured as described above, the water guiding member is formed by twisting wires.

  According to the present invention, the heat exchange efficiency of the indoor unit of the air conditioner can be increased by mounting the parallel flow heat exchanger having high heat exchange efficiency. And, since the flat tube of the parallel flow type heat exchanger of the side flow method that forms the roof shape above the cross flow fan has a gradient that the side close to the cross flow fan is high in the front-rear direction and the opposite side is low, Even if condensate is generated in the parallel flow heat exchanger, it flows in the direction away from the cross flow fan along the slope of the flat tube and does not hit the cross flow fan. For this reason, the situation where a water droplet blows off with an air current can be avoided.

It is a schematic sectional drawing of the indoor unit of the air conditioner which concerns on embodiment of this invention. It is a typical vertical sectional view of the heat exchanger mounted in the indoor unit of FIG. It is a partial expanded vertical sectional view of the heat exchanger mounted in the indoor unit of FIG. It is a schematic block diagram of the air conditioner which concerns on embodiment of this invention, and shows the state at the time of air_conditionaing | cooling operation. It is a schematic block diagram of the air conditioner which concerns on embodiment of this invention, and shows the state at the time of heating operation.

  First, a basic configuration of a separate type air conditioner that uses a heat pump cycle as a refrigeration cycle will be described with reference to FIGS. 4 and 5. The heat pump cycle 1 includes a compressor 2, a four-way valve 3, an outdoor heat exchange unit 4, a decompression expansion device 5, and an indoor heat exchange unit 6 connected in a loop.

  The compressor 2, the four-way valve 3, the heat exchange unit 4, and the decompression / expansion device 5 are accommodated in the casing of the outdoor unit 10, and the heat exchange unit 6 is accommodated in the casing of the indoor unit 20. A fin-and-tube heat exchanger is used for the heat exchange unit 4, and a parallel flow type heat exchanger is used for the heat exchange unit 6.

  The heat exchanger 4 is combined with an outdoor fan 11, and the heat exchanger 6 is combined with an indoor fan 21. The fan of the blower 11 is a propeller fan 12, and the fan of the blower 21 is a cross flow fan 22. Both the blower 11 and the blower 21 are disposed downstream of the heat exchange units 4 and 6 with respect to the airflow generated by them.

  FIG. 4 shows a state during cooling operation or defrosting operation. At this time, the high-temperature and high-pressure refrigerant discharged from the compressor 2 enters the heat exchange section 4 on the outdoor side, where it dissipates heat and condenses. The refrigerant exiting the heat exchanging unit 4 enters the indoor heat exchanging unit 6 from the decompression / expansion device 5 and expands there, absorbs heat from the indoor air, and then returns to the compressor 2. The airflow generated by the outdoor blower 11 promotes heat dissipation from the heat exchange unit 4, and the airflow generated by the indoor blower 21 promotes heat absorption of the heat exchange unit 6.

  FIG. 5 shows a state during heating. At this time, the four-way valve 3 is switched so that the refrigerant flow is reversed during the cooling operation or the defrosting operation. That is, the high-temperature and high-pressure refrigerant discharged from the compressor 2 enters the indoor heat exchanging section 6 where it dissipates heat and condenses. The refrigerant exiting the heat exchange unit 6 enters the outdoor heat exchange unit 4 from the decompression / expansion device 5 and expands there, absorbs heat from the outdoor air, and returns to the compressor 2. The airflow generated by the blower 21 on the indoor side promotes heat radiation from the heat exchange unit 6, and the airflow generated by the blower 11 on the outdoor side promotes heat absorption of the heat exchange unit 4.

  The heat exchanging unit 6 includes two side flow parallel flow type heat exchangers 30 and 40. As shown in FIG. 1, the parallel flow type heat exchanger 30 is configured by stacking two unit heat exchangers 100A, and the parallel flow type heat exchanger 40 is configured by stacking two unit heat exchangers 100B. The The structure of the unit heat exchanger 100A will be described with reference to FIG.

  The unit heat exchanger 100A is a side flow type parallel flow type heat exchanger, and two vertical header pipes 101 and 102 are arranged in parallel at intervals in the horizontal direction, and between the header pipes 101 and 102. A plurality of horizontal flat tubes 103 are arranged at a predetermined pitch in the vertical direction. The flat tube 103 extends left and right when the unit heat exchanger 100A is viewed from the front.

  The flat tube 103 is an elongated molded product obtained by extruding a metal, and a refrigerant passage 104 through which a refrigerant flows is formed inside. Since the flat tube 103 is disposed so that the extrusion direction, which is the longitudinal direction, is horizontal, the refrigerant flow direction of the refrigerant passage 104 is also horizontal. A plurality of refrigerant passages 104 having the same cross-sectional shape and the same cross-sectional area are arranged in the depth direction of FIG. 2, so that the vertical cross section of the flat tube 103 has a harmonica shape. Each refrigerant passage 104 communicates with the inside of the header pipes 101 and 102. Corrugated fins 105 are arranged between adjacent flat tubes 103.

  A combination of corrugated fins 105 and side plates 106 is arranged on the flat surface facing the outside of the flat tube 103 located on the outermost side among the flat tubes 103 in which a plurality of tubes are arranged in a single vertical row.

  The header pipes 101 and 102, the flat tubes 103, the corrugated fins 105, and the side plates 106 are all formed of a metal having good thermal conductivity such as aluminum. The flat tube 103 is fixed to the header pipes 101 and 102, the corrugated fin 105 is fixed to the flat tube 103, and the side plate 106 is fixed to the corrugated fin 105 by brazing or welding.

  In the unit heat exchanger 100A, the refrigerant inlets and outlets 107 and 108 are provided only in the header pipe 101. That is, the header pipe 101 is a header pipe on the refrigerant pipe connection side. Inside the header pipe 101, two partition plates 109a and 109c are provided with a space in the vertical direction. Inside the header pipe 102, the partition plates are located at a height intermediate between the partition plates 109a and 109c. 109b is provided.

  When the unit heat exchanger 100A is used as an evaporator, the refrigerant flows from the lower refrigerant inlet / outlet port 108 as indicated by solid line arrows in FIG. The refrigerant entering from the refrigerant inlet / outlet 108 is blocked by the partition plate 109 c and travels to the header pipe 102 via the flat tube 103. This refrigerant flow is represented by a left-pointing block arrow. The refrigerant that has entered the header pipe 102 is blocked by the partition plate 109 b and travels toward the header pipe 101 via another flat tube 103. This refrigerant flow is represented by a right-pointing block arrow. The refrigerant that has entered the header pipe 101 is blocked by the partition plate 109 a and travels again to the header pipe 102 via another flat tube 103. This refrigerant flow is represented by a left-pointing block arrow. The refrigerant that has entered the header pipe 102 is folded back, and further travels toward the header pipe 101 via another flat tube 103. This refrigerant flow is represented by a right-pointing block arrow. The refrigerant that has entered the header pipe 101 flows out of the refrigerant inlet / outlet 107. In this way, the refrigerant follows the zigzag path and flows from the bottom to the top. Although the case where the number of partition plates is 3 is shown here, this is only an example, and the number of partition plates and the number of times the resulting refrigerant flow may be folded may be set as desired. it can.

  The structure of the unit heat exchanger 100B is the same as that of the unit heat exchanger 100A. However, since the unit heat exchanger 100B is longer in the vertical direction than the unit heat exchanger 100A, it is possible to set a larger number of zigzag folds than the unit heat exchanger 100A.

  As shown in FIG. 1, the parallel flow type heat exchangers 30 and 40 are disposed above the cross flow fan 22 so as to lean against each other and close to each other at the upper ends, thereby forming an inverted V-shaped roof shape. Form. The two unit heat exchangers 100A and the two unit heat exchangers 100B are connected in series, the refrigerant inlet / outlet serving as one end of the series connection is connected to the decompression / expansion device 5, and the refrigerant inlet / outlet serving as the other end has four sides. It is connected to the compressor 2 via the valve 3.

  During the cooling operation, the refrigerant flowing out from the decompression / expansion device 5 enters the parallel flow heat exchangers 30 and 40. The refrigerant that has entered the parallel flow heat exchangers 30 and 40 expands, takes heat from the indoor air, then moves toward the outdoor unit 10 and is sucked into the compressor 2 via the four-way valve 3.

  During the heating operation, the high-temperature and high-pressure refrigerant discharged from the compressor 2 enters the parallel flow heat exchangers 30 and 40. The refrigerant that has entered the parallel flow heat exchangers 30 and 40 dissipates heat to the indoor air and condenses. Thereafter, the refrigerant goes to the outdoor unit 10 and flows into the heat exchange unit 4 on the outdoor side through the decompression and expansion device 5. The refrigerant expands inside the heat exchange unit 4, absorbs heat from the outdoor air, and returns to the compressor 2 via the four-way valve 3.

  The structure of the indoor unit 20 will be described with reference to FIG. The indoor unit 20 has an elongated casing 23 that extends in the depth direction of the paper surface, and a cross flow fan 22 is disposed therein in such a manner that the axis line coincides with the longitudinal direction of the casing 23. The housing 23 is attached to the wall surface in such a manner that the left side in FIG. 1 is the front side and the right side is the back side, and the back side is pressed against the wall surface.

  Suction ports 24 and 25 for sucking room air are formed on the top surface and the front surface of the housing 23, and a blow-out port 26 for blowing out the temperature-adjusted air is formed below the front surface. An air guide path 27 that guides air blown out from the cross flow fan 22 is connected to the air outlet 26. An electric louver 28 is disposed at the air outlet 26. The louver 28 closes the air outlet 26 as shown in FIG. 1 when the indoor unit 20 is in a stopped state. However, when the operation of the indoor unit 20 is started, the louver 28 rotates in the vertical plane to open the air outlet 26. open. The louver 28 also plays a role of changing the direction of the wind blown from the air outlet 26.

  When the cross flow fan 22 rotates, indoor air is sucked from the suction ports 24 and 25 and blown out from the air outlet 26, resulting in a circulating airflow in the room. When a low-temperature refrigerant flows through the heat exchanger 6, cold air blows out from the outlet 26, and when a high-temperature refrigerant flows through the heat exchanger 6, hot air blows out from the outlet 26.

  Inside the housing 23, a water receiving part for receiving the dew condensation water and defrost water dripping from the heat exchanger 6 is formed. A water receiver 50 is provided for the parallel flow heat exchanger 30, and a water receiver 51 is provided for the parallel flow heat exchanger 40. Each of the water receiving portions 50 and 51 has a shape like a bowl, and the water received by the water receiving portions 50 and 51 is drained outside the room through a drain pipe (not shown).

  In the present invention, when the flat tube 103 of the parallel flow heat exchangers 30 and 40 is incorporated in the casing 23 of the indoor unit 20 as described above, Then, in the depth direction of the paper surface, the side close to the crossflow fan 22 is high, and the opposite side is low in slope. FIG. 3 shows a part of the parallel flow heat exchanger 40. The flat tube 103 of the parallel flow heat exchanger 30 has a gradient opposite to that of the flat tube 103 shown in FIG.

  Since the flat tube 103 has the gradient as described above, even if condensed water is generated in the parallel flow heat exchangers 30 and 40, it is a direction away from the cross flow fan 22 along the gradient of the flat tube 103. And does not fall on the crossflow fan 22. For this reason, the situation where a water droplet blows off with an air current can be avoided.

  The cross flow fan 22 exerts a negative pressure on the side where the parallel flow heat exchangers 30 and 40 are present, and generates an airflow in a direction against water droplets flowing along the gradient of the flat tube 103. The slope value of the flat tube 103 is set so that water drops are not lost to the airflow and blown toward the cross flow fan 22.

  In the embodiment, in order to separate the condensed water from the cross flow fan 22, another contrivance is made.

  It is a water guide member 60 disposed at the end of the flat tube 103 on the side far from the cross flow fan 22. The corrugated fin 105 is fixed to the flat tube 103 so that the end far from the cross flow fan 22 protrudes from the end of the flat tube 103. The linear water guide member 60 is inserted into the gap formed by the protruding portions of the corrugated fins 105. And the space | interval of the water guide member 60 and the protrusion end of the corrugated fin 105 located on it is set to the distance which the surface tension of water can work between both.

  The water guide member 60 is formed by twisting two wires. The wire material is selected from the same material as the flat tube 103 and the corrugated fin 105, for example, aluminum in order to prevent electrolytic corrosion. The length of the water guiding member 60 is substantially the same as the length of the flat tube 103.

  When condensed water accumulates at the end of the corrugated fin 105, a bridge phenomenon (a film of water stretches) occurs on the end surface of the corrugated fin 105 due to the surface tension of the water. Not only the end face of the corrugated fin 105 but also a bridge phenomenon occurs between the water guide member 60 inserted under the corrugated fin 105 and the end of the corrugated fin 105. Further, a bridging phenomenon also occurs between the water guiding member 60 and the corrugated fin 105 located therebelow. By such a chain of bridging phenomena, a water conduit that extends from the upper part to the lower part is formed, and the condensed water quickly flows down. The water that has flowed down is dripped from the lower ends of the parallel flow heat exchangers 30 and 40, received by the water receivers 50 and 51, and drained.

  As described above, the flat tube 103 has a gradient in which the side close to the cross flow fan 22 is high and the opposite side is low, and the water guide member 60 is provided at the end of the flat tube 103 on the side far from the cross flow fan 22. The condensate generated in the parallel flow type heat exchangers 30 and 40 is caused to flow away from the cross flow fan 22 and further to the lower ends of the parallel flow type heat exchangers 30 and 40 at once. Since it can be dropped, the condensate does not hang down from the parallel flow heat exchangers 30 and 40 and is not applied to the cross flow fan 22. For this reason, the situation where a water droplet blows off with an air current can be avoided reliably.

  Since the water guide member 60 is formed by twisting wires, the water guide member 60 can be firmly fixed to the parallel flow heat exchangers 30 and 40. Mold does not easily occur.

  The outer diameter of the water guide member 60 is set to be slightly larger than the width of the gap (equal to the thickness of the flat tube 103) so that the water guide member 60 is not easily dropped from the inserted gap. Is good. Alternatively, the water guide member 60 may be waved and held by bending stress received from the corrugated fins 105.

  Although the embodiments of the present invention have been described above, the scope of the present invention is not limited to these embodiments, and various modifications can be made without departing from the spirit of the invention. For example, in the above embodiment, as shown in FIG. 1, the parallel flow heat exchanger 30 is configured by stacking two unit heat exchangers 100 </ b> A, but one of the two unit heat exchangers 100 </ b> A. It is good also considering a piece as an auxiliary heat exchanger. Similarly, although the parallel flow type heat exchanger 40 is configured by stacking two unit heat exchangers 100B, one of the two unit heat exchangers 100B may be used as an auxiliary heat exchanger.

  The present invention is widely applicable to indoor units of air conditioners.

1 Heat pump cycle (refrigeration cycle)
DESCRIPTION OF SYMBOLS 2 Compressor 3 Four-way valve 4 Outdoor heat exchange part 5 Depressurization expansion apparatus 6 Indoor heat exchange part 10 Outdoor unit 11 Outdoor blower 12 Propeller fan 20 Indoor unit 11 Indoor blower 22 Cross flow fan 30, 40 Parallel flow type heat exchanger 100A, 100B Unit heat exchanger 103 Flat tube 105 Corrugated fin 60 Water guide member

Claims (3)

In an indoor unit of an air conditioner including a cross flow fan that circulates indoor air and a heat exchanging unit arranged on the upstream side of the cross flow fan,
The heat exchange unit includes a plurality of parallel flow type heat exchangers that are arranged above the cross flow fan and form a roof shape in which upper ends approach each other. Is also a side flow system, and includes a plurality of flat tubes extending left and right when viewed from the front, and corrugated fins are disposed between the flat tubes, and the flat tubes are close to the cross flow fan in the front-rear direction. An indoor unit of an air conditioner characterized in that the side has a gradient that is high and the opposite side is low. Wherein the corrugated Fi down, the so protrude farther side end from the cross flow fan from the end of the flat tube, is inserted a linear water guide member to form a gap of the protruding portion to each other, and the water guide member, on which The indoor unit of an air conditioner according to claim 1 , wherein the distance from the protruding end of the corrugated fin located at a distance between the corrugated fins is a distance at which a surface tension of water can work. The indoor unit of an air conditioner according to claim 2 , wherein the water guiding member is formed by twisting wires.

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