JPS621520B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a heat exchanger for a cooling machine such as a separate air conditioner. The purpose is to measure the improvement of heat exchange efficiency.

A plate-type heat exchanger commonly used in the past has plate fins 1 as shown in FIGS. 1 and 2.
On the other hand, an expanded copper tube 2 is formed, and when the refrigerant flows in from the refrigerant inlet tube 3, it passes through the copper tube 2, which is a single path, and is connected to an expansion mechanism (not shown) etc. from the refrigerant outlet tube 4. It flows to However, due to the configuration of the outdoor unit, the ventilation path by the blower is determined from the direction of ventilation arrow A, so the heat exchange efficiency can only be obtained by the size of the heat exchanger determined in the design, and the heat exchange efficiency is limited. It had the disadvantage that it was not able to fully demonstrate the performance of the device.

That is, in FIG. 2, the refrigerant flows in from the refrigerant inlet pipe 3, goes down the single-pass copper pipe 2 one after another, and heads for the capillary tube etc. from the refrigerant outlet 4, whereas when it is cooled from the air blowing arrow A, the heat is released. Exchange rate distribution 5
The efficiency is high in the vicinity of the upper part 6 because it is near the inlet where the gas flows in, and is low in the vicinity of the lower part 7. This means that the refrigerant entering from the refrigerant inlet pipe 3 is
Since it is a high-temperature, high-pressure refrigerant gas sent from a compressor, the heat exchange efficiency is high in the upper part 6, and as it flows downward 7, the difference in temperature with the blast air becomes smaller. As the distance increases, the heat exchange efficiency decreases. However, at this time, although the refrigerant is condensed from a gaseous state, the entire condensation point is almost entirely condensed in the lower part 7 before the refrigerant outlet pipe 4. This is shown in Figure 6. Conventionally, as shown by the dotted line, the initial heat exchange rate is fast, but the final total condensation point is slow, so the length of the copper tube is required to reach outlet B. It is.

The present invention solves the above-mentioned conventional drawbacks, and one embodiment thereof will be described below with reference to FIGS. 3 to 5.

In the figure, reference numeral 11 denotes a first heat exchanger, and plate fins 12 are provided with a large pitch interval. 13
is a second heat exchanger, and the pitch interval of the plate fins 14 is set small. High-temperature, high-pressure refrigerant from a compressor (not shown) flows into the refrigerant inlet pipe 15 of the first heat exchanger 11 and passes through the usual copper pipe 1 arranged in a meandering manner.
6, from the lower side 18 through the connecting pipe 17 to the upper side 19 of the second heat exchanger 13, and in the second heat exchanger, the refrigerant passes through the inner wall grooved copper tube 20 and heads toward the expansion mechanism (not shown). It is designed to reach an outlet pipe 22. The well-known grooved tube 21 shown in FIG. 4 is used as the inner wall grooved copper tube 20, and in the second heat exchanger 13, the flow is from the upper side to the lower side to reduce resistance loss. Note that, as in the conventional case, arrow B indicates the air flow path from the same direction by the blower, and 23 in FIG. 5 indicates the heat exchange coefficient distribution.

In the above configuration, the high-temperature, high-pressure refrigerant enters from the refrigerant inlet pipe 15, passes through the copper pipe 16 of the first heat exchanger 11, and undergoes heat exchange by blowing air.While being condensed, the refrigerant passes through the connecting pipe 17 extending from the bottom to the top. Head to the heat exchanger 13. In this almost condensed state, when it flows to the second heat exchanger 13, it flows intensively to the heat exchange section where the pitch interval is small and the efficiency is improved by flowing it through the grooved copper tube 20. The condensation of the refrigerant is accelerated as it moves towards the refrigerant outlet pipe 22. Therefore, the refrigerant inlet pipe 15
The high-temperature, high-pressure refrigerant that has entered is first transferred to the first heat exchanger 1.
At step 3, the air passes through the copper pipe 16 at a high speed, quickly reducing the difference in temperature with the blown air, and is directed to the highly efficient second heat exchanger 13, where intensive heat exchange is performed. let

To explain this in Fig. 6, as shown by the solid line, the heat exchange efficiency in the first heat exchanger is slower than in the past, but in the second heat exchanger,
They obtained experimental results that the speed was increased and the final total condensation point was earlier.

As described above, according to the present invention, in order to improve the heat exchange efficiency of the refrigerant, in order to cool or heat the mixed state of gas and liquid, the copper tubes are divided into sections, rather than having a uniform arrangement. The heat exchanger has a large fin pitch and uses regular copper tubing to keep costs low. On the other hand, in other heat exchangers, by reducing the fin pitch and using grooved copper tubes, the second heat exchanger allows the flow to flow from the top to the bottom, reducing loss resistance and increasing the total heat This made it possible to increase exchange efficiency. This is the 6th
As shown in the figure, the total length of the copper tube can be shortened by about 10% compared to the conventional one by moving from outlet B at the point of full condensation to outlet A. It also exhibits effects such as being advantageous in terms of cost.

[Brief explanation of the drawing]

Fig. 1 is a perspective view of a conventional heat exchanger, Fig. 2 is an explanatory view of the same, Fig. 3 is a perspective view of a heat exchanger according to an embodiment of the present invention, and Fig. 4 is a perspective view of a heat exchanger used in the second heat exchanger. FIG. 5 is an explanatory diagram of heat exchange efficiency, and FIG. 6 is a comparison diagram of the conventional example and the embodiment of the present invention at the time of complete condensation of the refrigerant. 11...First heat exchanger, 13...Second heat exchanger, 16...Ordinary copper pipe, 17...Connecting pipe, 21
...Grooved copper tube.

Claims (1)

[Claims] 1. In a heat exchanger for an outdoor unit such as a separate air conditioner, the heat exchanger is divided into a first heat exchanger and a second heat exchanger, and the first heat exchanger has a large fin pitch. The second heat exchanger uses a copper tube with a grooved inner wall with a small fin pitch, and the second heat exchanger has a small fin pitch and a grooved copper tube. A heat exchanger in which the first heat exchanger and the second heat exchanger are arranged in parallel, connected in series through connecting pipes piped from the bottom to the top.