JPH08200886A - Heat exchanger air conditioning - Google Patents

Abstract

PURPOSE: To provide a heat exchanger for air conditioning with excellent heat exchange efficiency by constructing the exchanger such that a refrigerant uniformly flows into each heat transfer pipe with reduced pressure loss. CONSTITUTION: A second distributor 5 and a third distributor 8 are mounted on lower ends of a first intermediate header 4 and a second intermediate header 7, and four conduits are branched and extended from each first distributor, six conduits 6 from each second distributor 5, and seven conduits 9 from each third distributor 8. A connection pipes 17 are connected with an outlet header 10 from each upper end of the second intermediate header 7.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the structure of a heat exchanger for an air conditioner.

[0002]

2. Description of the Related Art In a conventional heat exchanger attached to an outdoor unit of an air conditioner, as disclosed in Japanese Examined Patent Publication No. 3-45300, a refrigerant is distributed from a header of an inlet portion to a plurality of tubes and fin groups are provided. It was configured to pass.

[0003]

However, in the heat exchanger having the conventional structure, the refrigerant flowing into the intermediate header at the time of evaporation rises in the intermediate header and has a hole formed in the middle of the header. Since a large amount of refrigerant flows into the heat transfer tube on the lower side, the amount of inflow into the heat transfer tube decreases toward the top, and in the worst case, heat transfer did not occur in some heat transfer tubes. .

At the time of evaporation, the liquid refrigerant and the gas refrigerant are mixed in the heat transfer tube, but the gas refrigerant is mixed even though it hardly contributes to heat exchange. The heat exchange of the liquid refrigerant is also hindered, and the evaporation performance is deteriorated.

Further, the volume of the refrigerant passing through the heat exchanger increases as the evaporation proceeds. In this situation, if the divided tubes have the same diameter from the header of the inlet to the outlet like the conventional heat exchanger, the flow velocity increases and the pressure loss increases as they approach the outlet. .

[0006]

The present invention uses the following means in order to solve the above problems. That is, a plurality of intermediate headers are provided between an inlet distributor into which the refrigerant flows during evaporation and an outlet header from which the refrigerant also flows out, and a large number of heat transfer tubes are arranged so that a fin group is passed between these headers. In the heat exchanger for air conditioning connected to each other, a distributor was attached to one end of the intermediate header.

Similarly, in the heat exchanger for air conditioning, a distributor is attached to the lower part of the intermediate header.

Also, in the heat exchanger for air conditioning, the refrigerant flowing into the intermediate header is separated into a gas refrigerant and a liquid refrigerant, and only the liquid refrigerant is passed through the heat transfer tube.

Further, in an air conditioning heat exchanger in which a distributor is installed at one end (lower part) of the intermediate header, the distribution installed in the intermediate header is more than the number of heat transfer tubes that make the refrigerant flow into the intermediate header during evaporation. The number of conduits that allow the refrigerant to flow out of the container has been increased.

[0010]

Next, the operation of the present invention will be described. First,
By mounting the distributor on one end of the intermediate header, while maintaining the condensation performance using the intermediate header in the heat exchanger, the gas refrigerant and the liquid refrigerant that have flowed into the intermediate header at the time of evaporation are separated by the distributor. It is possible to make it evenly flow out to each heat transfer tube.

Further, in the above, when the distributor is mounted on the upper part of the intermediate header, the liquid refrigerant having a large specific gravity which has not yet evaporated and has flowed into the intermediate header at the time of evaporation flows upward in the intermediate header against gravity. Therefore, the pressure loss in the header increases, but if the distributor is mounted in the lower part of the intermediate header, the liquid refrigerant stays in the distributor and the pressure loss is reduced.

Further, by separating the refrigerant flowing into the intermediate header into a liquid refrigerant and a gas refrigerant and exchanging heat in the separated state, only the evaporable liquid refrigerant contributes to the heat exchange and the evaporation performance is improved.

Further, by increasing the number of conduits through which the refrigerant flows out from the distributor, as compared with the heat transfer tubes through which the refrigerant flows into the intermediate header at the time of evaporation, the volume increases as the evaporation progresses while passing through the heat exchanger. The pressure loss of the refrigerant is reduced.

[0014]

The problems and configurations to be solved by the present invention are as described above, and the embodiments of the present invention shown in the accompanying drawings will be described below. FIG. 1 is a front view of the inside of a heat exchanger for air conditioning of the present invention,
2 is an internal front view showing an embodiment configured to separate the gas refrigerant from the intermediate header, FIG. 3 (a) is a plan view of an air conditioning heat exchanger, FIG. 3 (b) is the same internal plan view, and FIG. 3A is an internal front view of the air conditioning heat exchanger taken along the line EE in FIG. 3A, FIG. 5 is a left side view of the air conditioning heat exchanger taken along the line AA, and FIG. 6 is taken along the line BB. FIG. 7 is a left side view taken along the line CC of FIG. 7, FIG. 7 is a left side view taken along the line D-D of FIG. 8, and FIG.
FIG. 9B is a view including the second intermediate header 7 and the outlet header 10, FIG. 9 is a right side view, and FIG. 10 is a partial front sectional view of the distributor.

The structure of the air conditioning heat exchanger of the present invention will be described. The main body 1 of the heat exchanger has a fin group sandwiched between a left side plate 1L and a right side plate 1R on the header side,
As shown in FIG. 3B, three rows of heat transfer tubes are penetrating in the fin group of the main body 1 in the left-right direction in a plan view, and the heat transfer tubes are arranged on the vertical surface of the row closest to the rear surface. The heat transfer tubes 14 are the ones, the heat transfer tubes 15 are those arranged on the vertical surface of the middle row, and the heat transfer tubes 16 are those arranged on the vertical surface of the row closest to the front. b), as shown in FIGS. 4 and 9, the heat transfer tube 14 and the heat transfer tube 15 are provided outside the right side plate 1R of the main body 1.
1 and 2 are connected by a U-shaped connecting pipe 11, and also outside the right side plate 1R, as shown in FIG. 1 (FIG. 2), FIG. 3 (b),
As shown in FIG. 9, the upper and lower heat transfer pipes 16 and 16 are connected by the U-shaped connecting pipe 13, and the upper and lower heat transfer pipes 16 and 16 are connected outside the left side plate 1L as shown in FIGS. 3B, 4 and 5. Book heat transfer tube 1
5 and 15 are connected by a U-shaped connecting pipe 12.

In the heat exchanger having the heat transfer tubes thus arranged, as shown in FIG. 4, four conduits 3, 3 ... Are extended from the two first (inlet) distributors 2, respectively. As shown in FIG. 8, it is connected to the left end portion of the heat transfer tube 14 penetrating so as to pass through the fin group in the main body 1 through the inlet hole 1a formed in the left side plate 1L of the main body 1. , Moreover, U-shaped connecting tube 1
1, the heat transfer tube 15, the U-shaped connection tube 12, the heat transfer tube 15, the U-shaped connection tube 11, and the heat transfer tube 14, and an exit hole formed in the left side plate 1L of the main body 1 as shown in FIGS. 4 introduction pipes 4 extended from the first intermediate header 4 of a vertical pipe via 1b
It is connected to the right end of one of a. Therefore, the refrigerant introduced from each conduit 3 extending from the first distributor 2 makes two round trips through the heat transfer tubes 14 and 15 in the fin group of the main body 1 until reaching the first intermediate header 4. It is composed.

The first intermediate header 4 is provided in upper and lower two, and the second distributor 5 is attached to one end of the first intermediate header 4. In the present embodiment, FIGS. As shown in FIG. 8, it is attached to the lower end of the first intermediate header 4 (the upper end is closed). Six conduits 6, 6 ... Are extended from the lower part of the second distributor 5, and each conduit 6 is shown in FIG.
(B), as shown in FIG. 4 and FIG. 8, it is connected to the heat transfer tube 14 through the inlet hole 1c formed in the left side plate 1L of the main body 1, and further through the U-shaped connection tube 11 and the heat transfer tube 15. As shown in FIG. 3 (b), FIG. 4, FIG. 7, and FIG.
It is connected to one of the right ends of the six introducing pipes 7a, 7a, ... Extending from the second intermediate header 7 through an outlet hole 1d formed in the left side plate 1L.

The second intermediate header 7 is shown in FIG. 1, FIG. 4, FIG.
As shown in FIG. 8, two upper and lower parts are arranged, the lower end of each second intermediate header 7 is open (the upper end is closed), and the third distributor 8 is mounted. Seven conduits 9, 9 ... Are extended from the lower part of the third distributor 8, and each conduit 9 is located on the left side of the main body 1 as shown in FIGS. 1, 3 (b) and 7. It is connected to the left end of the heat transfer tube 16 via an inlet hole 1e formed in the plate 1L, and further has a U-shaped connecting tube 13 and the heat transfer tube 1.
1 and 3 (through one round trip within the fin group) via 6
(B) As shown in FIG. 6, each of the 14 inlet pipes 10a, 10a, ... Extending from the outlet header 10 is connected via an outlet hole 1f formed in the left side surface of the main body 1. .

Further, in the embodiment shown in FIG. 2, the upper ends of the first intermediate header 4 and the second intermediate header 7 are opened, and the connecting pipes 17, 17 ...
Of the first intermediate header 4 and the second intermediate header 7, and the gas refrigerant is introduced from the liquid / gas mixed refrigerant in the first intermediate header 4 and the second intermediate header 7 to flow out into the outlet header 10.

The flow of the refrigerant in the heat exchanger having the above structure will be described. First, in the embodiment shown in FIG. 1, the saturated gas and liquid refrigerant flow into the first distributor 2 during evaporation, and flow into the first intermediate header 4 via the conduit 3, the heat transfer tubes 14 and 15, and the like. , And are evenly distributed from the second distributor 5 to the respective conduits 6, 6, ... Outgoing, again flowing into the second intermediate header 7 and mixed, and then being supplied from the third distributor 8 to the conduit 9.・ Distributed evenly to 9 ...

As described above, in the embodiment shown in FIG. 1, the liquid / gas two-phase refrigerant passes through the heat transfer tube.
In the illustrated embodiment, of the two-phase refrigerants that have flowed into the first intermediate header 4 and the second intermediate header 7, the gas refrigerant has a small specific gravity, so it rises and flows out into the connection pipe 17 from each upper end. On the other hand, since the liquid refrigerant has a large specific gravity, it drops downward and flows into the second distributor 5 / third distributor 8 and thus into the heat transfer pipes 14, 15/16 through the conduits 6/9. The refrigerant that flows in is mainly a liquid refrigerant, which reduces pressure loss (increased pressure) and increases the probability that the liquid refrigerant that absorbs the heat of evaporation directly contacts the inner wall of the heat transfer tube, so that the heat exchange efficiency is improved. improves.

Further, in both the embodiments shown in FIGS. 1 and 2, by mounting the second distributor 5 and the third distributor 8 on one end of the first intermediate header 4 and the second intermediate header 7, respectively. Heat transfer tube 1 that branches and extends after each intermediate header 4 and 7
Since the refrigerant is evenly distributed in 4.15.16, the heat generated by the deviation of the refrigerant flowing into the heat transfer tube, such that the refrigerant hardly flows into a certain heat transfer tube and heat exchange is not performed, The adverse effect of the deterioration of the exchange efficiency is reduced.

In the heat exchanger, the volume of the heat exchanger increases due to vaporization of the refrigerant while passing from the inlet portion (first distributor 2) to the outlet portion (outlet header 10) during evaporation. If the increase in pressure loss is not suppressed by increasing the passage capacity of the refrigerant in proportion to the increase, the pressure of the refrigerant will increase on the upstream side. That is, the temperature of the refrigerant on the upstream side increases as compared with the temperature on the downstream side. Therefore, the difference between the temperature of the upstream side refrigerant and the temperature of the air passing through the fin group 1 becomes small, and the heat exchange efficiency decreases. Therefore, the flow velocity of the refrigerant is suppressed as much as possible at the outlet portion. That is, it is necessary to have a structure with less pressure loss.

Therefore, in the present embodiment, first, as described above, in the structure in which the second distributor 5 and the third distributor 8 are attached to one end of the first intermediate header 4 and the second intermediate header 7, respectively, The second distributor 5 and the third distributor 8 are attached to the lower ends of the first intermediate header 4 and the second intermediate header 7. That is, of the liquid refrigerant / gaseous refrigerant flowing into the first intermediate header 4 / second intermediate header 7, the liquid refrigerant that contributes to evaporation for heat exchange falls downward because of its large specific gravity, It is configured to naturally flow into the second distributor 5 and the third distributor 8. If the second distributor 5 and the third distributor 8 are mounted on the upper ends of the first intermediate header 4 and the second intermediate header 7, the liquid refrigerant having a large specific gravity moves upward in the intermediate header against the gravity. Flowing into the second distributor 5 / third distributor 8, the pressure loss increases, but since it is attached to the lower end, such pressure loss is suppressed.

The conduits 3, 6.9 and 9 extending from the first distributor 2, the second distributor 5, and the third distributor 8 each have four upstream conduits 3 and downstream conduits. There are six conduits 6 and seven downstreammost conduits 9. That is, since the number of conduits extending from one distributor to the downstream side is increased to increase the passage capacity of the refrigerant, without increasing the flow rate of the refrigerant whose volume increases toward the downstream side, that is,
The pressure loss can be reduced.

Further, in the internal structure of each of the first distributor 2, the second distributor 5, and the third distributor 8, the opening diameter (or passage length) of the orifice 18 shown in FIG.
Is designed to be small in the first distributor 2 on the upstream side, slightly large in the second distributor 5, and maximized in the third distributor 8 on the most downstream side. The pressure loss can be reduced without increasing the flow velocity of the refrigerant, which has a larger passage capacity and increases in volume toward the downstream side, at the outlet portion.

In addition, if the inner diameters of the first intermediate header 4, the second intermediate header 7, and the outlet header 10 are increased as they move from the upstream first intermediate header 4 to the downstream outlet header 10, the same effect is obtained. Play.

The structure of the heat exchanger of the present invention has been described above on the basis of the flow of the refrigerant at the time of evaporation, but at the time of condensation, the superheated steam refrigerant flows from the outlet header 10,
It flows out of the first distributor 2 via the second intermediate header 7 and the first intermediate header 4 in the route opposite to the above. In this process, the refrigerant condenses and releases the heat of condensation to the outside. The first distributor 2 on the downstream side of the outlet header 10 which is on the upstream side of each conduit 9 and 6 and on the opposite side to the evaporation time. The number of conduits (the number of heat transfer tubes) decreases with the transition to. This is because the superheated vapor refrigerant flowing in from the outlet header 10 is condensed as it passes through the heat transfer tube and its volume is reduced, so that the pressure loss hardly rises even if it is reduced with each intermediate header used. is there.

The refrigerant flowing into the third distributor 8 and the second distributor 5 is mixed there and flows into the second intermediate header 7 and the first intermediate header 4, and the third distributor 8 and the second distributor Bowl 5
Are attached to the lower ends of the second intermediate header 7 and the first intermediate header 4, respectively, so that the heat transfer tubes connected to the upper ends of the second intermediate header 7 and the first intermediate header 4 are A large amount of gas refrigerant having a small specific gravity flows in. That is, the liquid refrigerant accumulates on the entire inner surface of the heat transfer tube immediately before the distributor to impede heat transfer, but the heat transfer tube connected to the upper ends of the second intermediate header 7 and the first intermediate header 4 transfers heat. The liquid film that inhibits is not deposited. Further, in the heat transfer tube connected to the lower end, liquid is deposited on the lower surface but not on the upper surface, and the condensation effect is high. As described above, the heat exchanger of the present invention also has an excellent effect on the condensation performance.

[0030]

Since the present invention is constructed as described above,
The following effects are obtained. That is, in the heat exchanger at the time of evaporation, the refrigerant is evenly distributed to each heat transfer tube by configuring as in claim 1, and the pressure loss in each intermediate header by configuring as in claim 2. And also
According to the third aspect of the invention, a large amount of liquid refrigerant is sent into the heat transfer tube, the vaporizing effect is small, and the gas refrigerant that causes a pressure loss increase is separated and does not pass through the heat transfer tube. Further, with the structure according to claim 4, the flow velocity of the refrigerant whose volume increases toward the downstream side is reduced and the pressure loss is reduced.
As described above, since the pressure loss is small and the refrigerant is evenly distributed to the heat transfer tubes, it is possible to provide an excellent air conditioning heat exchanger having a very high heat exchange rate.

[Brief description of drawings]

FIG. 1 is an internal front view of a heat exchanger for air conditioning of the present invention.

FIG. 2 is an internal front view showing an embodiment similarly configured to separate the gas refrigerant from the intermediate header.

3A is a plan view of an air conditioning heat exchanger, and FIG. 3B is an internal plan view of the same.

FIG. 4 is an internal front view of the air conditioning heat exchanger taken along the line EE in FIG.

FIG. 5 is a left side view of the air conditioning heat exchanger taken along the line AA.

FIG. 6 is a left side view of the same taken along the line BB.

FIG. 7 is a left side view of the same taken along the line C-C.

8 is a left side view of the same taken along the line D-D, FIG. 8A is a diagram including a second intermediate header 7 and an outlet header 10, and FIG.
FIG. 6 is a diagram in which the second intermediate header 7 and the exit header 10 are removed.

FIG. 9 is a right side view of the same.

FIG. 10 is a partial front sectional view of the distributor.

[Explanation of symbols]

 1 Main Body 1L Left Side Plate 1R Right Side Plate 1a Inlet Hole 1b Outlet Hole 1c Inlet Hole 1d Outlet Hole 1e Inlet Hole 1f Outlet Hole 2 First Distributor 3 Conduit 4 First Intermediate Header 4a Inlet Pipe 5 Second Distributor 6 Conduit 7 Second intermediate header 7a Introducing pipe 8 Third distributor 9 Conduit 10 Outlet header 10a Introducing pipe 11 U-shaped connecting pipe 12 U-shaped connecting pipe 13 U-shaped connecting pipe 14 Heat transfer pipe 15 Heat transfer pipe 16 Heat transfer pipe 17 Connection pipe 18 Orifice

Claims (4)

[Claims] 1. An inlet distributor into which a refrigerant flows during evaporation,
Similarly, in an air-conditioning heat exchanger in which a plurality of intermediate headers are provided between the outlet headers from which the refrigerant flows and a large number of heat transfer tubes are connected so that fin groups pass between these headers, A heat exchanger for air conditioning, characterized in that a distributor is attached to one end of the. 2. An inlet distributor into which a refrigerant flows during evaporation,
Similarly, in an air-conditioning heat exchanger in which a plurality of intermediate headers are provided between the outlet headers from which the refrigerant flows and a large number of heat transfer tubes are connected so that fin groups pass between these headers, A heat exchanger for air conditioning, characterized in that a distributor is attached to the lower part of the. 3. An inlet distributor into which the refrigerant flows during evaporation,
Similarly, in an air-conditioning heat exchanger in which a plurality of intermediate headers are provided between the outlet headers from which the refrigerant flows and a large number of heat transfer tubes are connected so that fin groups pass between these headers, A heat exchanger for air conditioning, characterized in that the refrigerant flowing into is separated into a gas refrigerant and a liquid refrigerant, and only the liquid refrigerant is passed through the heat transfer tube. 4. The air conditioner heat exchanger according to claim 1, wherein the number of heat transfer tubes that allow the refrigerant to flow into the intermediate header during evaporation is greater than that of the conduits through which the refrigerant flows out from the distributor attached to the intermediate header. A heat exchanger for air conditioning characterized by increasing the number.