The present invention relates to an outdoor unit of an air conditioning apparatus and, more particularly, to improvement of a drain water discharge structure.
When a heating mode of operation is performed in an outdoor unit of a separate type air conditioning apparatus, a heat exchanger is deprived of heat by a turning fan. At this time, the heat exchanger condenses the water vapor in the air, causing its surface to be frosted. As time progresses, such frost develops and finally impedes air flow through the heat exchanger and prevents heat from moving. This inhibits heat exchange and heating in a room. To avoid this, the outdoor unit generally performs defrosting operation for a predetermined period of time, thereby melting the frost for resumption of heat exchange. After that, heating and defrosting modes of operation are repeated.
During the defrosting mode of operation, the frost on the external surface of the heat exchanger melts and drops down as drain water droplets. Conventional outdoor units have a drain water discharge conduit provided on its bottom plate beneath the heat exchanger for discharging the drain water. Such a drain water discharge conduit has a horizontal section formed at a lowest portion thereof, the horizontal section having a drain hole through which the drain water is discharged (for example, see Japanese Unexamined Patent Application Publication No.
Drain water droplets from such an outdoor unit drop onto the discharge conduit into the drain hole through which the drain water is discharged to the outside. However, in a cold area the drain water may freeze before reaching the drain hole at low ambient temperatures. In particular, the drain water may freeze in the horizontal section around the drain hole, blocking the drain hole or the drain water discharge conduit. If this happens, not only does the frozen drain water inhibit the discharge of the drain water to the outside, but also may cause the horizontal section to further expand to such a degree that the flow of the drain water is degraded, which causes a great amount of water remaining inside the unit to more and more tend to freeze. In addition, each time heating and defrosting modes of operation are repeated, the frozen drain water further develops, causing the heat exchanger to malfunction and damaging the outdoor unit.
The present invention has been achieved to solve the above-described problems. A first object of the present invention is to provide an outdoor unit which ensures that drain water is discharged on a rapid manner, and a drain hole is prevented from freezing so that the drain water can be discharged even in a cold area.
A second object of the present invention is to provide an outdoor unit which has a bottom plate having a shallow depth, thereby improving the workability as well as strength.
An outdoor unit of the present invention is described in the independent claim 1. Therein, aspects of the present invention are as follows:
According to an outdoor unit of an air conditioning apparatus of the present invention, a bottom plate has a conduit forming wall formed upright thereon along the heat exchanger, and a water conduit formed by the conduit forming wall has a drain hole and a downwardly tilted surface continuous with the drain hole, which allows drain water droplets to flow to the drain hole without reducing its flow rate. This ensures that drain water passages concentrate and that drain water reaches the drain hole without freezing, thereby preventing the blockage of the drain hole or the water conduit. Also, the conduit forming wall formed upright on the bottom plate along the heat exchanger serves as a reinforcement rib of the bottom plate. Accordingly, workability as well as strength can be improved without deepening the bottom plate in the direction of the depth.
The present invention is described based on an embodiment as shown in the figures.
An outdoor unit 100 of an air conditioning apparatus according to this embodiment includes a heat exchanger 2, a compressor 3, a blower 4, and a partition 5 mounted on a steel bottom plate 1 in the form of a rectangular solid, as shown in
The bottom plate 1 includes a frame la (hereinafter referred to as "peripheral frame") surrounding the bottom plate 1 and a conduit forming wall 1c formed upright along the heat exchanger 2. A water conduit 1d is formed by partitioning with the conduit forming wall 1c and the peripheral frame 1a. The conduit forming wall 1c prevents drain water from flowing into below the heat exchanger 2 or out of the water conduit.1d. The water conduit 1d has a normally open drain hole 1b for discharging drain water to the outside and a downwardly tilted surface 1e (equal to the bottom face of the water conduit) continuous with the drain hole lb. The bottom plate 1 is also formed as a whole to be downwardly tilted toward the drain hole 1b.
The water conduit 1d has a plurality of heat exchanger mounting bases 1f formed at an edge and a corner thereof. The heat exchanger 2 is placed and secured on the mounting bases 1f. The mounting bases 1f are formed to have a height smaller than that of the adjacent conduit forming wall 1c or the peripheral frame 1a. The bottom plate 1 has the peripheral frame 1a, the conduit forming wall 1c, the tilted surface 1e, and the heat exchanger mounting bases 1f integrally formed thereon by press working.
When the air conditioning apparatus according to this embodiment performs heating operation, the surface of the heat exchanger 2 in the outdoor unit 100 becomes frosted. Defrosting mode of operation is performed for a certain period of time to melt the frost on the surface. Water generated by such defrosting mode of operation drops as drain water onto the downwardly tilted surface 1e continuous with the drain hole 1b in the water conduit 1d on the bottom plate 1 and is guided to the drain hole 1b. Accordingly, such drain water flows at a high rate only below the heat exchanger 2, while concentrating. This prevents the drain water from freezing in the water conduit 1d before it reaches the drain hole 1b even at low ambient temperatures in a cold area, thereby securely discharging the drain water.
The mounting bases 1f formed to have a height smaller than that of the adjacent conduit forming wall 1c or the peripheral frame 1a ensures that the drain water downwardly flowing on the external surface of the heat exchanger 2 drops onto the water conduit 1d through the lower end of the heat exchanger 2.
As described above, the outdoor unit of an air conditioning apparatus according to this embodiment includes the downwardly tilted surface 1e continuous with the drain hole 1b and the conduit forming wall 1c formed upright along the heat exchanger 2 so as to prevent the drain water from flowing other than below the heat exchanger 2, which allows drain water passages to concentrate, raises the drain water flow rate, and prevents the drain water from freezing before it reaches the drain hole 1b, thereby securing that the drain water is discharged to the outside. This prevents the drain hole 1b and the water conduit 1d from being blocked.
The conduit forming wall 1c formed to have an upright structure also serves as a reinforcement rib of the bottom plate 1. This improves workability of steel sheet working (sheet metal working) as well as the strength of the bottom plate 1 without deepening the bottom plate 1 in the direction of the depth.
This list of references cited by the applicant is for the reader's convenience only. It does not form part of the European patent document. Even though great care has been taken in compiling the references, errors or omissions cannot be excluded and the EPO disclaims all liability in this regard.