JPH0252793B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a heat exchanger for refrigeration, such as an evaporator for a refrigerator-freezer, in which air is ventilated and generates a refrigeration temperature, thereby causing frost formation.

This type of heat exchanger is generally known as a finch-tube heat exchanger in which fins and pipes are arranged orthogonally, and the arrangement of the fins and the pipes inserted through the fins is shown in Figures 1 and 2. The following are known. That is, in Fig. 1, the pipes b are arranged in a grid pattern with respect to the fins a, and in this case, the pipes b are arranged in a straight line with respect to the air flow (indicated by arrows in the figure). Therefore, even if frost forms on pipe b' on the inflow side, the air volume is unlikely to decrease, but on the other hand, there are fewer opportunities for circulating air to come into contact with the pipe on the leeward side, and the absolute value of the refrigerating capacity decreases. will also become smaller. On the other hand, in Fig. 2, the pipes d are arranged in a staggered manner with respect to the fins c, and in this case, the pipes in the previous stage are prevented from coming into contact with the air flow (indicated by arrows in the figure). The absolute value of the refrigerating capacity is large, but once frost forms on the pipe d′ or d″ on the air inlet side, the airflow is greatly obstructed and the number of times defrosting is increased. ing.

The present invention has been accomplished in an effort to eliminate such drawbacks and provide a new refrigeration heat exchanger that has sufficient refrigeration capacity and is less likely to reduce air volume during frosting.
One embodiment of the present invention will be described below with reference to the accompanying drawings.

In the figure, 1 indicates a refrigeration heat exchanger main body as an evaporator for a refrigerator-freezer, with end plates 2 and 3 on both sides and a large number of plates arranged in parallel at approximately equal intervals between the end plates 2 and 3. shape fin 4,
4... and a pipe 5 as a refrigerant passage which is meanderingly inserted through the end plates 2, 3 and the fins 4, 4... in a perpendicular manner. Reference numeral 6 denotes an accumulator which is interposed in a part of a pipe serving as a refrigerant outlet. The arrangement of the pipes 5 to the fins 4, 4... and the end plates 2, 3 is such that the front two rows on the air inflow side are arranged in a checkerboard pattern with respect to the air flow toward the main body 1 (indicated by arrows in the figure). The front three and subsequent rows are arranged in a so-called staggered pattern, with the arrangement changing for each row. That is, from the air inflow side, the pipes 5b in the second row are aligned on the same straight line with respect to the pipes 5a in the front row, and the pipes 5c in the third row are aligned in the same straight line with the pipes 5a and 5b in the two rows. However, the pipe 5d in the fourth row is also the same as above 3.
The pipes 5a, 5b, and 5c of the row are not in the same straight line. Further, the pipe 5e in the fifth row is aligned with the pipe 5c in the third row, and the pipe 5f in the sixth row.
are aligned in the same straight line as the fourth row of pipes 5d, and have a similar arrangement pattern. In order to obtain the above-mentioned piping means, the end plates 2, 3 and the fins 4, 4... have holes 7, 7 for inserting the pipes 5.
... are drilled regularly in advance, and the pipe 5
The piping is not done so that all of these holes 7, 7... are inserted, but the piping is done according to the amount of frost in the system, but at least the front two rows should be sparser than the third and subsequent rows. is preferable. Therefore, this piping means and further pipes 5a arranged in a grid pattern,
5b has up to two rows, whereas the staggered pipes 5c, 5d, 5e... are formed over three or more rows, so the latter pipe density is greater than the former pipe density. It's getting bigger in width. Furthermore, the fins 4, 4... are not a single piece that exists continuously from the air inflow side to the air outflow side.
fins 4a and fins 4b in the staggered pipe arrangement section.

Therefore, when the heat exchanger main body 1 is used as a refrigeration system and is equipped with piping such as a compressor, a condenser, a pressure reducer (all not shown), etc., and is installed in a refrigerator as shown by the arrow in the figure, , frost formation starts on the main body 1 from the air inflow side. However, the grid-like arrangement of pipes 5a and 5b reduces the amount of airflow even when frost forms, and the staggered arrangement of pipes 5c and 5
d, 5e...The opportunity for air circulation increases with respect to the array, and the absolute value of the refrigerating capacity increases. In addition, to prevent the air volume from decreasing, the pipes 5a and 5 are arranged in a grid pattern.
This also contributes to the fact that b is sparse, and the staggered arrangement of pipes 5c, 5d, 5e, . . . is dense, so that the refrigerating capacity does not decrease. Furthermore, the fins 4, 4... are the fins 4a of the grid-like pipe arrangement part.
Since the pipes are separated by the fins 4b of the staggered pipe arrangement section, the capacity is improved due to the front boundary layer effect.
When frost forms on the fins 4a, it is difficult for the frost to transfer to the fins 4b, and the amount of frost can be maintained at a low level in the staggered arrangement where ventilation is likely to be obstructed by frost, greatly improving the refrigeration capacity during frost formation. can be expected.

As is clear from the above description, according to the present invention, the pipe arrangement is arranged in a checkerboard pattern on the inlet side of the heat exchanger where air is likely to form frost, and in other parts where frost is difficult to form, it is arranged in a staggered pattern. Since the pipe density in the grid section is higher than that in the grid section, the air volume is less likely to decrease during frost formation, and the capacity can be expected to increase at this time. This prevents deterioration in performance and also enables miniaturization as a whole.

[Brief explanation of the drawing]

1 and 2 are explanatory diagrams of the piping pattern to the fins in a conventional heat exchanger, FIG. 3 is a plan view of a refrigeration heat exchanger according to an embodiment of the present invention, and FIG. 4 is a diagram of FIG. A cross-sectional view taken along the line ' is shown. 4...Fin, 5...Pipe, 5a, 5b...
Checkerboard arrangement pipes, 5c, 5d, 5e... staggered arrangement pipes.

Claims (1)

[Claims] 1 Consisting of a large number of fins arranged in parallel and pipes inserted perpendicularly through these fins, the pipe arrangement to the fins is arranged in parallel on the same straight line with respect to the air flow on the air inflow side. A heat exchanger for refrigeration, characterized in that the pipes are arranged in a grid pattern and the others in a staggered pattern, and the density of the pipes arranged in a staggered pattern is greater than the density of the pipes arranged in a grid pattern. vessel.