JP2000266426A - Heat exchanger and cooling system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat exchanger and a cooling system in which the quantity of refrigerant can be reduced by enhancing the heat exchanging power and global warming can be prevented. SOLUTION: Inside diameter of heating tubes 11, 12, 13, 14, 15, 16 is decreased gradually from the gas refrigerant side G toward the liquid refrigerant side L. Since the inside diameter of heating tubes 11, 12 on the gas refrigerant side G is larger than the inside diameter of heating tubes 15, 16 on the liquid refrigerant side L, pressure loss of the gas refrigerant is reduced. Since condensed liquid refrigerant flows through the small diameter heating tubes 14, 15, 16 on the liquid refrigerant side L, heat exchange efficiency is enhanced on the liquid refrigerant side L while preventing shifted flow of the liquid refrigerant and dew formation.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat exchanger and a refrigeration apparatus capable of reducing the amount of refrigerant and preventing global warming.

[0002]

2. Description of the Related Art For example, a heat exchanger used in a cooling / heating air conditioner must serve as both an evaporator and a condenser. Conventionally, in this type of heat exchanger, a heat transfer tube of one kind of diameter is used, and emphasis is placed on the function of either the evaporator or the condenser, and the inner diameter of the heat transfer tube is reduced to prevent pressure loss and drift. It was determined from the viewpoint of performance and reliability.

[0003] In addition, although there are originally optimal paths for the heat transfer tubes (setting of the number of paths and arrangement of the paths) for each of the evaporator and the condenser, the heat exchanger is provided with the evaporator and the condenser. Since both functions of the evaporator and the condenser must be performed, the function of the evaporator or the condenser is emphasized.

[0004]

Since the Kyoto International Conference on Global Warming in December 1998, it has been recognized that it is extremely important to reduce the amount of refrigerant in order to prevent global warming. It has come to be.

In view of the above, the present inventor has conceived that, in the above-mentioned conventional heat exchanger, a heat transfer tube of one kind of pipe diameter is used, and a pass is taken with emphasis on the function of either the evaporator or the condenser. As a result, it was found that there was a problem that the effective heat transfer area could not be sufficiently increased, the heat exchange capacity was low, and the required refrigerant amount was large.

Accordingly, an object of the present invention is to provide a heat exchanger and a refrigeration apparatus that can increase the heat exchange capacity and reduce the amount of refrigerant to prevent global warming.

[0007]

According to a first aspect of the present invention, there is provided a heat exchanger, wherein the total cross-sectional area of the heat transfer tube on the liquid refrigerant side is equal to the total cross-sectional area of the heat transfer tube on the gas refrigerant side. It is characterized by being smaller than the cross-sectional area.

By the way, from the viewpoint of the flow resistance of the refrigerant, that is, the pressure loss, it is preferable that the heat transfer tube be thick. On the other hand, from the viewpoint of the efficiency of heat exchange and the prevention of liquid refrigerant drift, the narrower the heat transfer tube, the better.

On the other hand, when the heat exchanger functions as a condenser, the refrigerant flows in the heat transfer tube while changing from a gas state to a liquid state. On the other hand, when the heat exchanger functions as an evaporator, the refrigerant transfers heat. The liquid flows from the liquid state to the gas state in the pipe.

[0010] At this time, the flow resistance and pressure loss when the gas refrigerant flows through the heat transfer tube are significantly larger than the volume of the liquid refrigerant when the liquid refrigerant flows through the heat transfer tube. Greater than.

Therefore, in the first aspect of the present invention, the total cross-sectional area of the inner diameter of the heat transfer tube on the gas refrigerant side where the pressure loss usually increases is made larger than the total cross-sectional area of the inner diameter of the heat transfer tube on the liquid refrigerant side,
The pressure loss due to the heat transfer tube on the gas refrigerant side is reduced. Thus, the heat transfer tube according to the first aspect of the invention is the most effective setting from the viewpoint of reducing pressure loss.

On the other hand, the heat exchanger tubes of the heat exchanger are thinner and more efficient in heat exchange than thicker ones, are less likely to cause liquid refrigerant drift, and have no risk of dew condensation.

Therefore, in the invention of claim 1, the total cross-sectional area of the inner diameter of the heat transfer tube on the liquid refrigerant side is made smaller than the total cross-sectional area of the inner diameter of the heat transfer tube on the gas refrigerant side. Therefore, claim 1
In the prior art, the efficiency of heat exchange on the liquid refrigerant side of the heat exchanger is such that the total cross-sectional area of the inner diameter of the heat transfer tube on the liquid refrigerant side is equal to the total cross-sectional area of the inner diameter of the heat transfer tube on the gas refrigerant side. As compared with the above, it is possible to prevent the liquid refrigerant from drifting and prevent dew condensation.

Therefore, in the heat exchanger according to the first aspect of the present invention, the pressure loss can be effectively suppressed, the heat exchange efficiency can be increased, and the drift of the liquid refrigerant can be prevented.
The total heat exchange capacity is increased, and the amount of refrigerant in the refrigeration system using this heat exchanger can be reduced. Therefore, global warming can be prevented.

In the heat exchanger according to the first aspect of the present invention, the material for parts can be reduced and the cost can be reduced by reducing the total sectional area of the inner diameter of the heat transfer tube on the liquid refrigerant side.

Here, the liquid refrigerant side of the heat transfer tube of the heat exchanger means the inlet side of the heat transfer tube in the evaporator and the outlet side of the heat transfer tube in the condenser. The gas refrigerant side of the heat tube means the outlet side of the heat transfer tube in the evaporator and the inlet side of the heat transfer tube in the condenser.

The heat exchanger according to a second aspect of the present invention is the heat exchanger according to the first aspect, wherein the inner diameter of the heat transfer tube on the liquid refrigerant side is smaller than the inner diameter of the heat transfer tube on the gas refrigerant side. And

In the heat exchanger according to the second aspect of the present invention, the heat exchanger according to the first aspect is provided.
In this heat exchanger, the inner diameter of the heat transfer tube is smaller on the liquid refrigerant side and larger on the gas refrigerant side, so that the operational effect of claim 1 can be obtained with a simple configuration. That is, the following operation and effect can be obtained.

In the heat exchanger according to the second aspect of the present invention, the inner diameter of the heat transfer tube on the gas refrigerant side, which is significantly larger than the volume of the liquid refrigerant, is larger than the inner diameter of the heat transfer tube on the liquid refrigerant side. Loss is reduced. Therefore, the heat transfer tube of the heat exchanger according to the second aspect of the present invention can effectively reduce pressure loss with a simple configuration.

Further, in the heat exchanger according to the second aspect of the present invention, since the inner diameter of the heat transfer tube on the liquid refrigerant side is smaller than the inner diameter of the heat transfer tube on the gas refrigerant side, the heat transfer on the liquid refrigerant side of the heat exchanger is performed. The exchange efficiency is higher than the conventional example in which the inner diameter of the heat transfer tube on the liquid refrigerant side is equal to the inner diameter of the heat transfer tube on the gas refrigerant side, and the drift of the liquid refrigerant can be prevented, and dew condensation can be prevented. Can be prevented.

Therefore, in the heat exchanger according to the second aspect of the present invention, the pressure loss can be effectively suppressed, the heat exchange efficiency can be increased, and the drift and dew condensation of the liquid refrigerant can be prevented. Therefore, the heat exchange capacity is increased, and the amount of refrigerant in the refrigeration system using this heat exchanger can be reduced.
Therefore, global warming can be prevented.

A heat exchanger according to a third aspect of the present invention is the heat exchanger according to the first or second aspect, wherein the heat transfer tubes have the same number of paths on the liquid refrigerant side and the gas refrigerant side. I have.

According to the heat exchanger of the third aspect of the present invention, since the heat transfer tubes have the same number of passes on the liquid refrigerant side and the gas refrigerant side, the arrangement of the heat transfer tubes is simplified and the heat exchange is performed. The vessel can be manufactured simply and inexpensively.

According to a fourth aspect of the present invention, in the heat exchanger of the first or second aspect, the number of the heat transfer tubes on the liquid refrigerant side is smaller than that on the gas refrigerant side. And

In the heat exchanger according to the fourth aspect of the present invention, since the number of passes on the liquid refrigerant side is smaller than the number of passes on the gas refrigerant side, for example, the heat transfer tubes have the same inner diameter on the liquid refrigerant side and the gas refrigerant side. Even if a heat transfer tube having the following formula is used, the total cross-sectional area of the inner diameter of the heat transfer tube on the liquid refrigerant side can be easily made smaller than the total cross-sectional area of the inner diameter of the heat transfer tube on the gas refrigerant side.

Further, as in the heat exchanger according to the second aspect of the present invention,
After reducing the inner diameter of the heat transfer tube on the liquid refrigerant side and increasing the inner diameter of the heat transfer tube on the gas refrigerant side, if the number of passes on the liquid refrigerant side is smaller than the number of passes on the gas refrigerant side, simply The total cross-sectional area of the inner diameter of the heat transfer tube can be made extremely smaller than the total cross-sectional area of the inner diameter of the heat transfer tube on the gas refrigerant side.

The heat exchanger according to the fifth aspect of the present invention is characterized in that the inner diameter of the heat transfer tube on the liquid refrigerant side is smaller than the inner diameter of the heat transfer tube on the gas refrigerant side.

In the heat exchanger according to the fifth aspect of the present invention, the inner diameter of the heat transfer tube on the gas refrigerant side, which is significantly larger than the volume of the liquid refrigerant, is larger than the inner diameter of the heat transfer tube on the liquid refrigerant side. The loss can be made extremely small. Therefore, the heat transfer tube of the heat exchanger according to the fifth aspect of the invention has the simplest configuration and is the most effective setting from the viewpoint of reducing pressure loss.

According to the fifth aspect of the present invention, since the inner diameter of the heat transfer tube on the liquid refrigerant side is smaller than the inner diameter of the heat transfer tube on the gas refrigerant side, the efficiency of heat exchange on the liquid refrigerant side of the heat exchanger is reduced. As compared with the conventional example in which the inner diameter of the heat transfer tube on the gas refrigerant side is made equal to the inner diameter of the heat transfer tube on the gas refrigerant side, the liquid refrigerant can be prevented from drifting and dew condensation can be prevented.

Therefore, according to the fifth aspect of the present invention, since the efficiency of heat exchange can be increased while the pressure loss is reduced, and the drift and dew condensation of the liquid refrigerant can be prevented, the heat exchange ability can be increased as a whole. In addition, the amount of refrigerant in a refrigeration apparatus using this heat exchanger can be reduced. Therefore, global warming can be prevented.

Further, in the heat exchanger according to the fifth aspect of the present invention, the material of parts can be reduced and the cost can be reduced by reducing the inner diameter of the heat transfer tube on the liquid refrigerant side.

A heat exchanger according to a sixth aspect of the present invention is the heat exchanger according to any one of the first to fifth aspects, further comprising a plurality of blocks each having a heat transfer tube inserted through a plurality of fins.
The fins of at least two blocks of the plurality of blocks are different from each other in at least one of a fin pattern and a fin width.

A heat exchanger according to a sixth aspect of the present invention includes the plurality of blocks, and fins of at least two blocks of the plurality of blocks are different from each other in at least one of a fin pattern and a fin width. Therefore, even when the inner diameter or the number of passes differs between the liquid refrigerant side and the gas refrigerant side of the heat transfer tube, the heat transfer tube can be easily adapted to the fin.

A heat exchanger according to a seventh aspect of the present invention is the heat exchanger according to any one of the first to fifth aspects, wherein the heat exchanger comprises only one block formed by inserting a heat transfer tube through a plurality of fins. The plurality of fins have substantially the same outer peripheral shape, and the fin patterns of at least two of the plurality of fins are different from each other.

The heat exchanger according to the invention of claim 7 comprises only one block, the plurality of fins have substantially the same outer peripheral shape, and at least two fins of the plurality of fins are provided. Fin patterns are different from each other,
Even if the inner diameter or the number of passes differs between the liquid refrigerant side and the gas refrigerant side of the heat transfer tube, the heat transfer tube can be simply and inexpensively adapted to the fin.

The heat exchanger according to the invention of claim 8 is the heat exchanger according to any one of claims 1 to 7, wherein the heat transfer tubes are arranged in two or more rows in a direction crossing the direction of wind flow. It is characterized by:

According to the heat exchanger of the present invention, since the heat transfer tubes are arranged in two or more rows in a direction crossing the traveling direction of the wind, the inner diameter or the inner side of the heat transfer tubes on the liquid refrigerant side and the gas refrigerant side is reduced. Even if the number of passes is different, arrange the heat transfer tubes optimally,
Heat exchange efficiency can be increased and noise can be reduced.

According to a ninth aspect of the present invention, in the heat exchanger of any one of the first to eighth aspects, the heat exchanger has a J-shape, an L-shape, or a U-shape. I have.

In the heat exchanger according to the ninth aspect of the present invention, since at least one of the inner diameter and the number of passes differs between the liquid refrigerant side and the gas refrigerant side of the heat transfer tube, the heat exchange capacity is improved. Since it is J-shaped, L-shaped or U-shaped, the structure is compact.

According to a tenth aspect of the present invention, in the heat exchanger according to any one of the first to ninth aspects, the inner peripheral surface of the heat transfer tube continuously changes in a conical shape. It is characterized by.

According to the heat exchanger of the tenth aspect, the inner peripheral surface of the heat transfer tube continuously changes in a conical shape. Therefore, the pressure loss in the heat transfer tube is further reduced, and the performance of the heat exchanger is improved.

The heat exchanger according to the eleventh aspect is characterized in that the number of heat transfer tubes on the liquid refrigerant side is smaller than the number of heat transfer tubes on the gas refrigerant side.

According to the heat exchanger of the eleventh aspect, the same operation and effect as those of the heat exchanger of the fourth aspect can be obtained.

A refrigeration apparatus according to a twelfth aspect of the present invention includes the heat exchanger according to any one of the first to eleventh aspects,
It is characterized by being filled with a C (hydrofluorocarbon) 32 type refrigerant.

In the refrigeration apparatus according to the twelfth aspect of the present invention, since the heat exchanger according to any one of the first to eleventh aspects is provided, the pressure loss of the heat transfer tube on the gas refrigerant side is small and the transfer loss on the liquid refrigerant side is small. Due to the high heat exchange efficiency and the effect of preventing drifting due to the small inner diameter of the heat tube or its total cross-sectional area, the heat exchanger has the effect of having a high heat exchange capacity. In addition, the HFC32-based refrigerant itself has a function of reducing pressure loss due to low viscosity, making it possible to reduce the diameter of the heat transfer tube, and having a high coefficient of performance (COP) and a low global warming coefficient (GWP). Any one of claims 1 to 10
By the synergistic effect of the operation effect of the two heat exchangers and the operation effect of the HFC32-based refrigerant itself, this refrigeration apparatus can significantly reduce the amount of the refrigerant, for example, the conventional refrigerant using HCFC (hydrochlorofluorocarbon) 22-based refrigerant. It was found that the global warming effect was lower than 1/12 as compared with the refrigeration system.

Here, the HFC32-based refrigerant is HFC3
Two refrigerants alone or a mixed refrigerant partially containing HFC32 refrigerant.

Further, the heat exchanger according to the thirteenth aspect is characterized in that the number of heat transfer tube paths differs between one end and the other end of the refrigerant inlet / outlet of the heat exchanger.

According to the heat exchanger of the thirteenth aspect, the one end having a large number of passes is connected to the gas refrigerant side and the other end having a small number of passes is connected to the liquid refrigerant side. The same operation and effect as those of the heat exchanger can be obtained.

Further, the heat exchanger of the invention according to claim 14 is the heat exchanger according to claim 13, wherein the number of passes of the heat transfer tube is three.
It is characterized by more than one stage.

According to the heat exchanger of the fourteenth aspect, if one end having a large number of passes is connected to the gas refrigerant and the other end having a small number of passes is connected to the liquid refrigerant, The same operation and effect as those of the heat exchanger can be obtained. Moreover, since the number of passes is three or more, the number of passes can be gradually changed.

Further, the heat exchanger according to the fifteenth aspect is characterized in that one end side and the other end side of the heat transfer tube have different inner cross-sectional areas.

According to the heat exchanger of the present invention, one end of the heat transfer tube having a large total cross-sectional area is connected to the gas refrigerant side, and the other end of the heat transfer tube having a small total cross-sectional area is connected to the liquid refrigerant side. With this, the same operation and effect as those of the heat exchanger of the first aspect can be obtained.

The heat exchanger according to the sixteenth aspect of the present invention is characterized in that heat exchanger tubes having different inner diameters are used.

According to the heat exchanger of the sixteenth aspect, the heat transfer tube on one end having a large inner diameter is connected to the gas refrigerant, and the heat transfer tube on the other end having a small inner diameter is connected to the liquid refrigerant. The same operation and effect as those of the heat exchanger of the fifth aspect can be obtained.

The heat exchanger according to the seventeenth aspect of the present invention has
It is characterized by the use of more than one type of heat transfer tubes with different inner diameters.

According to the heat exchanger of the seventeenth aspect, if the heat transfer tube at one end having a large inner diameter is connected to the gas refrigerant side and the heat transfer tube at the other end having a small inner diameter is connected to the liquid refrigerant side, The same operation and effect as those of the heat exchanger of the fifth aspect can be obtained. Moreover, since the heat transfer tubes have three or more inner diameters, the inner diameters can be gradually changed.

[0057]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the illustrated embodiments.

FIG. 1 shows a heat exchanger according to this embodiment. Although not shown, the heat exchanger 1 has a heat transfer tube inserted through a fin. The inner diameter of the heat transfer tube on the liquid refrigerant side L is smaller than the inner diameter of the heat transfer tube on the gas refrigerant side G. Further, in this heat exchanger 1, the number of heat transfer tubes on the liquid refrigerant side L is smaller than the number of heat transfer tubes on the gas refrigerant side G. Therefore, in this heat exchanger 1, the total cross-sectional area of the inner diameter of the heat transfer tube on the liquid refrigerant side L is significantly smaller than the total cross-sectional area of the inner diameter of the heat transfer tube on the gas refrigerant side G.

When the heat exchanger 1 functions as a condenser, the refrigerant flows as shown by a solid arrow in FIG. 1, while when it functions as an evaporator, the refrigerant flows as shown by a dashed arrow in FIG. Flows. That is,
When the heat exchanger 1 is a condenser, the gas refrigerant G
The end of the heat transfer tube on the liquid refrigerant side L is the inlet, and the end of the heat transfer tube on the liquid refrigerant side L is the outlet. On the other hand, when the heat exchanger 1 is an evaporator, the end of the heat transfer tube on the liquid refrigerant side L is the inlet. Thus, the end of the heat transfer tube on the gas refrigerant side G becomes the outlet.

Incidentally, there is a phenomenon as shown in FIG.
That is, in order to maximize the capacity (capacity considering heat exchange capacity and pressure loss) of the condenser and the evaporator, there is an optimum inner diameter of the heat transfer tube and the number of passes. Furthermore, the inside diameter and the number of passes of the heat transfer tubes that maximize the capacity of the condenser are respectively smaller than the inside diameter and the number of passes of the heat transfer tubes that maximize the capacity of the evaporator. Based on these phenomena, the present inventor has made the heat exchanger 1 of the above-described embodiment maximize the capacity regardless of whether it is used as a condenser or an evaporator.

In the above embodiment, the total cross-sectional area of the inner diameter of the heat transfer tube on the gas refrigerant side G is defined by the total cross-sectional area of the inner diameter of the heat transfer tube on the liquid refrigerant side L, through which the gas refrigerant having a significantly larger volume than the liquid refrigerant flows. The pressure loss of the gas refrigerant in the heat transfer tube on the gas refrigerant side G is reduced. As described above, since the generally large pressure loss on the gas refrigerant side G is reduced, the effect of reducing the pressure loss is large.

In the above embodiment, the total cross-sectional area of the heat transfer tube on the liquid refrigerant side L is smaller than the total cross-sectional area of the inner diameter of the heat transfer tube on the gas refrigerant side G. Heat exchange efficiency is higher than that of the conventional example in which the total cross-sectional area of the inner diameter of the heat transfer tube on the liquid refrigerant side is equal to the total cross-sectional area of the inner diameter of the heat transfer tube on the gas refrigerant side, and the liquid refrigerant is higher. Can be prevented and dew condensation can be prevented.

Therefore, the heat exchanger 1 of this embodiment
Therefore, the pressure loss can be effectively reduced, the efficiency of heat exchange can be increased, and the drift and dew condensation of the liquid refrigerant can be prevented. The amount of refrigerant in the refrigeration system used can be reduced. Therefore, global warming can be prevented.

Further, in the heat exchanger 1, the amount of component materials can be reduced and the cost can be reduced by reducing the total cross-sectional area of the inner diameter of the heat transfer tube on the liquid refrigerant side L.

FIG. 3 shows a heat exchanger 10 according to another embodiment. In this heat exchanger 10, the fins 9 are connected to the heat transfer tubes 1
1, 12, 13, 14, 15, 16 penetrate and heat transfer tube 1
1 and 12 are connected by a U vent 17, heat transfer tubes 13 and 14 are connected by a U vent 18, and heat transfer tubes 15 and 16 are connected by a U vent 1
9 is connected. The heat transfer tubes 11, 12, 13, 1
4, 15 and 16 constitute one pass, and are tapered from the gas refrigerant side G to the liquid refrigerant side L stepwise. That is,
The inner diameter of each of the heat transfer tubes 11, 12, 13, 14, 15, 16 is gradually reduced from the heat transfer tube 11 to the heat transfer tube 16.

Now, suppose that the gas refrigerant flows into the large-diameter heat transfer tube 11, condenses, and the liquid refrigerant flows out of the small-diameter heat transfer tube 16 using the heat exchanger 10 as a condenser.

At this time, the heat transfer tubes 11, 1 on the gas refrigerant side G are
2 is larger than the inner diameter of the heat transfer tubes 15 and 16 on the liquid refrigerant side L, the volume of the gas refrigerant is significantly larger than the volume of the liquid refrigerant, but the inner diameter of the heat transfer tubes is the same throughout. The pressure loss of the gas refrigerant is extremely small as compared with the case where the pressure is low. Thus, the heat transfer tubes 11, 12, 13,
The pressure loss on the gas refrigerant side G can be reduced with a simple and inexpensive configuration in which the inner diameters of 14, 15, and 16 are gradually reduced.

On the other hand, the condensed liquid refrigerant flows through the small-diameter heat transfer tubes 14, 15, 16 on the liquid refrigerant side L.
Since the inner diameter of the heat transfer tubes 14, 15, 16 is smaller than the inner diameter of the heat transfer tubes 11, 12, 13 on the gas refrigerant side,
The efficiency of heat exchange on the liquid refrigerant side L is higher than when the inner diameter of the heat transfer tube on the liquid refrigerant side is equal to the inner diameter of the heat transfer tube on the gas refrigerant side, and the drift of the liquid refrigerant can be prevented. In addition, dew condensation can be prevented.

Therefore, the heat exchanger 1 of this embodiment
0, the gas refrigerant side G and the liquid refrigerant side L have the same number of passes, and the heat transfer tubes 11, 12, 13, 14, 15, 16 have a simple and inexpensive configuration in which the inner diameter of the heat transfer tubes 11, 12, 13, 14, 15, 16 is gradually reduced. Can be effectively reduced, and the efficiency of heat exchange can be increased,
In addition, since the drift and dew condensation of the liquid refrigerant can be prevented, the heat exchange ability is increased in total. Therefore, the amount of refrigerant in the refrigerating apparatus using the heat exchanger 10 can be reduced.
Therefore, global warming can be prevented.

Further, in the heat exchanger 10, parts materials can be reduced and the cost can be reduced by reducing the inner diameter of the heat transfer tubes 14, 15, 16 on the liquid refrigerant side L.

When the heat exchanger 10 is used as an evaporator, the liquid refrigerant flows into the small-diameter heat transfer tube 16 and the evaporated gas refrigerant flows out from the large-diameter heat transfer tube 11.

FIG. 4 shows a heat transfer tube 20 as an example used in the heat exchanger of the present invention. The heat transfer tube 20 has an inner diameter of 4 mm, 6 mm, from the liquid refrigerant side L to the gas refrigerant side G.
It is gradually increased to 7 mm, 8 mm, and 9.5 mm. This heat transfer tube 20 can be manufactured simply and at low cost.

Although not shown, it is desirable that the inner peripheral surface of the heat transfer tube changes continuously in a conical shape. In this case, the pressure loss in the heat transfer tube is further reduced, and the performance of the heat exchanger is further improved.

FIG. 5 shows only a heat transfer tube system 30 of a heat exchanger according to another embodiment. In this heat exchanger, the heat transfer tubes 31, 32, 33, and 34 having the same inner diameter are connected in a cascade manner, and the heat transfer tube 31 or the heat transfer tubes 32, 3 on the liquid refrigerant side L are connected.
The total cross-sectional area of the inner diameter of the heat transfer tubes 34, 3 on the gas refrigerant side G is
4, 34, 34 are smaller than the total cross-sectional area of the inner diameter.

The heat transfer tubes 34, 34, 34, 34
Is connected to a header (not shown).

In this embodiment, the heat transfer tubes 3 having the same inner diameter are used.
1, 32, 33, 34, the gas refrigerant side G and the liquid refrigerant L
By changing the number of passes between the heat transfer tubes 3 and 34 on the gas refrigerant side G, the total cross-sectional area of the inner diameter of the heat transfer tubes 34 and 34 on the gas refrigerant side G is changed.
Since the diameter is larger than the total cross-sectional area of the inner diameter of the first or second 32, the pressure loss of the gas refrigerant in the heat transfer tubes 34, 34, 34, 34 on the gas refrigerant side G can be reduced with a simple and inexpensive configuration. .

In the above embodiment, the heat transfer tubes 31, 32, 33, and 34 having the same inner diameter are connected in a cascade manner, and the total cross-sectional area of the inner diameter of the heat transfer tube 31 or 32, 32 on the liquid refrigerant side L is reduced. Heat transfer tubes 34, 34, 34, 3 on the gas refrigerant side G
4 is smaller than the total cross-sectional area of the inner diameter of the liquid refrigerant, the heat exchange efficiency on the liquid refrigerant side L depends on the total cross-sectional area of the inner diameter of the heat transfer tube on the liquid refrigerant side. As compared with the case where the area is equal to the area, the height is higher, and the drift of the liquid refrigerant can be prevented, and the dew condensation can be prevented.

Therefore, in the heat exchanger of this embodiment, the pressure loss can be reduced, the heat exchange efficiency can be increased, and the drift of the liquid refrigerant can be prevented. Ability increases. Therefore, the amount of refrigerant in the refrigerating apparatus using the heat exchanger can be reduced. Therefore, global warming can be prevented.

FIG. 6 shows only a heat transfer tube system 40 of a heat exchanger according to another embodiment. In this heat exchanger, the inner diameter of the heat transfer tube 41 or the heat transfer tubes 42, 42, 42 on the liquid refrigerant side L and the total cross-sectional area of the inner diameter are respectively transferred to the heat transfer tubes 45, 45, 45 or 45 on the gas refrigerant side G. Each inner diameter of the heat pipe 46 and the total cross-sectional area of the inner diameter are made smaller. Further, the heat transfer tubes 42, 42, 42 and the heat transfer tubes 45, 45, 45 are connected by one heat transfer tube 43, and the heat transfer tubes 42, 42, 4 are connected.
The influence of the drift of the liquid refrigerant in the heat transfer tubes 45, 45, 45
Less.

In this embodiment, the total cross-sectional area of the inner diameter of the heat transfer tubes 45, 45, 45 or 46 on the gas refrigerant side G is changed to the total cross-sectional area of the inner diameter of the heat transfer tubes 41 or 42, 42, 42 on the liquid refrigerant side L. The pressure loss of the gas refrigerant in the heat transfer tubes 45, 45, 45 and 46 on the gas refrigerant side G can be reduced with a simple and inexpensive configuration.

Also, in the above embodiment, the total cross-sectional area of the inner diameter of the heat transfer tube 41 or 42, 42, 42 on the liquid refrigerant side L is determined by the heat transfer tube 45, 45, 45 or 46 on the gas refrigerant side G.
Is smaller than the total cross-sectional area of the inner diameter of the heat transfer tube on the liquid refrigerant side L, the total cross-sectional area of the inner diameter of the heat transfer tube on the liquid refrigerant side is the total cross-sectional area of the inner diameter of the heat transfer tube on the gas refrigerant side. As compared with the case where the pressure is equal to the above, it is possible to prevent the liquid refrigerant from drifting and to prevent dew condensation.

Therefore, in the heat exchanger of this embodiment, the pressure loss can be reduced, the heat exchange efficiency can be increased, and the drift of the liquid refrigerant can be prevented. Ability increases. Therefore, the amount of refrigerant in the refrigerating apparatus using the heat exchanger can be reduced. Therefore, global warming can be prevented.

FIG. 7 shows an indoor unit 50 of an air conditioner. The indoor unit 50 has a cross flow fan 52 and a heat exchanger 53 provided in a casing 51.

In the heat exchanger 53 of this embodiment, a plurality of fins 54 are stacked at predetermined intervals in a direction perpendicular to the plane of the paper, and heat transfer tubes 55, 56, and 5 are mounted on these fins 54.
It consists of one J-shaped block with 7, 58 inserted. The plurality of stacked fins 54 have substantially the same outer peripheral shape. The heat transfer tubes 55 and 56 on the liquid refrigerant side L have small inside diameters, and the heat transfer tubes 57 and 58 on the gas refrigerant side G have large inside diameters. Further, the heat transfer tubes 55, 57;
6, 58 are arranged in two rows in a direction crossing the direction W in which the wind flows.

The heat transfer tubes 55, 56, 57, 58
The inner diameter gradually changes continuously or stepwise in a direction perpendicular to the paper surface, so that the inner diameter increases as the gas refrigerant increases. Accordingly, the fin patterns of the plurality of fins 54 (the size of the holes for inserting the heat transfer tubes and the arrangement of the holes) are different.

In the heat exchanger 53 of the above embodiment, the inner diameter of the heat transfer tubes 55 and 56 on the liquid refrigerant side L is small,
Of the heat transfer tubes 55, 5 as the gas refrigerant increases in the direction orthogonal to the paper surface.
Since the inner diameter of 6, 57, 58 is increased, the pressure loss can be extremely reduced, the efficiency of heat exchange can be extremely increased, and the drift of the liquid refrigerant can be extremely prevented. Therefore, the heat exchanger 53 has an extremely high heat exchange capacity in total. Therefore, the heat exchanger 53 can greatly contribute to the reduction of the refrigerant amount of the air conditioner. Therefore, it is very useful for preventing global warming.

The heat exchanger 53 of the above embodiment is
Since only one J-shaped block is formed and the plurality of fins 54 have substantially the same outer peripheral shape, the structure can be made compact, simple, and inexpensive.

The plurality of stacked fins 54
Since the fin patterns of the fins are different from each other, even if the heat transfer tubes 55, 56, 57, and 58 have different inner diameters or the number of passes in the direction perpendicular to the plane of the paper, the heat transfer tubes 55, 5,
6, 57, 58 can be easily and inexpensively adapted to the fins 54.

In the heat exchanger 53, the heat transfer tubes 5
Since the heat transfer tubes 55, 56, 57, and 58 are arranged in two rows in a direction crossing the wind traveling direction W, the heat transfer tubes 55, 56, 57, and
8. Even if the inner diameter or the number of passes differs between the liquid refrigerant side and the gas refrigerant side of No. 8, the heat transfer tubes 55, 56, 57, 58 are optimally arranged to increase heat exchange efficiency and reduce noise. Can be.

FIG. 8 shows a heat exchanger 60 according to another embodiment. The heat exchanger 60 includes a plurality of blocks 61,
62, 63 and 64 are arranged in a J-shape. Each block 61, 62, 63, 64 has a respective fin 81, 82,
83, 84 are stacked at predetermined intervals in a direction perpendicular to the plane of the paper, and each fin 81, 82, 83, 84
1, 73, 74 and 75 are respectively inserted.

The fins 81, 82, 83, 84
Have different sizes (width and length) and different fin patterns.

In the block 61, the heat transfer tubes 71 are arranged in a row in a direction crossing the wind traveling direction W.
In the example, the heat transfer tubes 73 are arranged in two rows in the direction crossing the wind traveling direction W, in the block 63, the heat transfer tubes 74 are arranged in two rows in the direction crossing the wind traveling direction W, and in the block 64,
The heat transfer tubes 75 are arranged in three rows P in a direction crossing the wind traveling direction W,
Q and R are arranged. The heat transfer tubes 71, 73, 74,
At 75, the total cross-sectional area of the gas refrigerant side inner diameter is larger than the total cross-sectional area of the liquid refrigerant side inner diameter.

In the heat exchanger 60, the heat transfer tubes 71, 7
In 3, 74 and 75, since the total cross-sectional area of the inner diameter on the gas refrigerant side is larger than the total cross-sectional area of the inner diameter on the liquid refrigerant side, the pressure loss can be reduced and the efficiency of heat exchange can be reduced. In addition, it is possible to prevent the liquid refrigerant from drifting and dew condensation. Therefore, the heat exchange capacity becomes extremely high in total. Therefore, the heat exchanger 60 can greatly contribute to the reduction of the amount of refrigerant, and can greatly contribute to prevention of global warming.

Since the heat exchanger 60 is composed of a plurality of blocks 61, 62, 63, 64 arranged in a J-shape, it can be manufactured simply and inexpensively in block units.

The plurality of blocks 61, 62, 6
The heat transfer tubes 7 and 64 have different sizes and fin patterns of the fins 81, 82, 83 and 84, respectively.
The heat transfer tubes 71, 7, 7, and 75 have different inner diameters or different numbers of passes between the liquid refrigerant side and the gas refrigerant side.
3, 74, 75 can be easily adapted to the fins 81, 82, 83, 84.

In the heat exchanger 60, the block 6
In FIG. 1, the heat transfer tube 71 is moved in the direction crossing the wind traveling direction W by one.
In the block 62, the heat transfer tubes 73 are arranged in two rows in a direction crossing the wind traveling direction W, and in the block 63, the heat transfer tubes 74 are arranged in two rows in a direction crossing the wind traveling direction W. In the block 64, the heat transfer tubes 75 are arranged in three rows P, Q, and R in a direction crossing the wind traveling direction W.
Even if the inner diameter or the number of passes differs between the liquid refrigerant side and the gas refrigerant side of the heat transfer tubes 71, 73, 74, 75, the heat transfer tubes 7
1, 73, 74, and 75 can be optimally arranged to increase heat exchange efficiency and reduce noise.

FIG. 9 shows an air conditioner as an example of a refrigerating apparatus according to another embodiment. This air conditioner includes a compressor 91, a four-way switching valve 92, an indoor heat exchanger 93,
An expansion valve 94 as an example of a pressure reducing mechanism, and the outdoor heat exchanger 9
5 are connected in order to form a refrigerant circuit. The refrigerant circuit is filled with HFC32-based refrigerant. The refrigerant circuit is filled with HFC32-based refrigerant.

The indoor heat exchanger 93 and the outdoor heat exchanger 95
As in the heat exchanger of the previous embodiment, the total cross-sectional area of the heat transfer tube on the gas refrigerant side is large and the total cross-sectional area of the heat transfer tube on the liquid refrigerant side is small.

The indoor heat exchanger 93 and the outdoor heat exchanger 95
Since the total cross-sectional area of the inner diameter of the heat transfer tube on the gas refrigerant side is large, the pressure loss of the heat transfer tube on the gas refrigerant side is small, and
Since the total cross-sectional area of the inner diameter of the heat transfer tube on the liquid refrigerant side is small, the heat exchange capacity on the liquid refrigerant side is high, the drift of the liquid refrigerant is prevented, and dew condensation is prevented. Therefore, the heat exchange capacity of the indoor heat exchanger 93 and the outdoor heat exchanger 95 is high. In addition, the HFC32-based refrigerant itself has a function of reducing pressure loss due to low viscosity, making it possible to reduce the diameter of the heat transfer tube, and having a high coefficient of performance (COP) and a low global warming coefficient (GWP).

Therefore, the synergistic effect of the function of the indoor heat exchanger 93 and the function of the outdoor heat exchanger 95 and the function of the HFC32-based refrigerant significantly reduced the amount of refrigerant in this air conditioner. It has been found that this air conditioner has, for example, a global warming effect lower than 1/12 as compared with a conventional air conditioner using an HCFC22-based refrigerant.

In the above embodiment, the heat exchanger is a fin type, but the heat exchanger may be a mesh type. Further, the heat exchanger is not limited to the J shape, but may be an L shape or a U shape.

In the above embodiment, the air conditioner for both cooling and heating is described as the refrigerating device. However, the present invention is also applicable to an air conditioner dedicated to cooling or a refrigerating device such as an ice making machine other than the air conditioner. Of course, it can be applied.

In the above embodiment, the refrigerant is H
Although the FC32-based refrigerant was used, the present invention is not limited to this, and the heat exchanger of the present invention has an effect that the capacity is high regardless of the refrigerant.

[0104]

As is clear from the above, according to the heat exchanger of the first aspect of the present invention, the total cross-sectional area of the inner diameter of the heat transfer tube on the liquid refrigerant side is reduced by the total cross-sectional area of the inner diameter of the heat transfer tube on the gas refrigerant side. Smaller, the efficiency of heat exchange on the liquid refrigerant side is increased, and the drift of the liquid refrigerant can be prevented, dew condensation can be prevented, and the pressure loss on the gas refrigerant side can be reduced. In addition, the heat exchange capacity is increased, and the amount of refrigerant can be reduced. Therefore, the heat exchanger according to the first aspect of the present invention can prevent global warming.

In the heat exchanger according to the first aspect of the present invention, the material for parts can be reduced and the cost can be reduced by reducing the total sectional area of the inner diameter of the heat transfer tube on the liquid refrigerant side.

In the heat exchanger according to the second aspect of the present invention, in the heat exchanger according to the first aspect, the inner diameter of the heat transfer tube on the liquid refrigerant side is smaller than the inner diameter of the heat transfer tube on the gas refrigerant side.
The operation and effect of the first aspect can be obtained with a simple configuration.

The heat exchanger according to the third aspect of the present invention is the heat exchanger according to the first or second aspect, wherein the heat transfer tubes have the same number of paths on the liquid refrigerant side and the gas refrigerant side. Can be easily arranged, and can be manufactured easily and inexpensively.

Further, in the heat exchanger according to the fourth aspect of the present invention, in the heat exchanger according to the first or second aspect, the number of passes of the heat transfer tube on the liquid refrigerant side is smaller than the number of passes on the gas refrigerant side. Even if the heat transfer tubes having the same inner diameter on the liquid refrigerant side and the gas refrigerant side are used, simply, the total cross-sectional area of the inner diameter of the heat transfer tube on the liquid refrigerant side is simply the total cross-sectional area of the inner diameter of the heat transfer tube on the gas refrigerant side. Can be smaller than Further, the heat exchanger according to the fourth aspect of the present invention, when the inner diameter of the heat transfer tube on the liquid refrigerant side is reduced and the inner diameter of the heat transfer tube on the gas refrigerant side is increased, as in the second aspect of the invention, Since the number of passes is smaller than the number of passes on the gas refrigerant side, the total cross-sectional area of the inner diameter of the heat transfer tube on the liquid refrigerant side is simply extremely smaller than the total cross-sectional area of the inner diameter of the heat transfer tube on the gas refrigerant side. can do.

In the heat exchanger according to the fifth aspect of the present invention, since the inner diameter of the heat transfer tube on the liquid refrigerant side is smaller than the inner diameter of the heat transfer tube on the gas refrigerant side, the efficiency of heat exchange on the liquid refrigerant side increases. In addition, the drift of the liquid refrigerant can be prevented, dew condensation can be prevented,
In addition, the pressure loss on the gas refrigerant side can be reduced, and the heat exchange capacity can be increased as a whole, and the amount of refrigerant can be reduced. Therefore, the heat exchanger according to the fifth aspect can prevent global warming.

Further, in the heat exchanger according to the fifth aspect of the present invention, the material of parts can be reduced and the cost can be reduced by reducing the inner diameter of the heat transfer tube on the liquid refrigerant side.

A heat exchanger according to a sixth aspect of the present invention is the heat exchanger according to any one of the first to fifth aspects, further comprising a plurality of blocks formed by inserting a heat transfer tube through a plurality of fins.
The fins of at least two blocks of the plurality of blocks have at least one of a fin pattern and a fin width different from each other. Therefore, the inner diameter or the number of passes differs between the liquid refrigerant side and the gas refrigerant side of the heat transfer tube. Even
The heat transfer tubes can be easily adapted to the fins.

A heat exchanger according to a seventh aspect of the present invention is the heat exchanger according to any one of the first to fifth aspects, wherein the heat exchanger comprises only one block formed by inserting a heat transfer tube through a plurality of fins. The plurality of fins have substantially the same outer peripheral shape, and since the fin patterns of at least two of the plurality of fins are different from each other, the inner diameter of the heat transfer tube between the liquid refrigerant side and the gas refrigerant side is different. Alternatively, even if the number of passes is different, the heat transfer tube can be easily and inexpensively adapted to the fin.

Further, the heat exchanger of the invention according to claim 8 is the heat exchanger according to any one of claims 1 to 7, wherein the heat transfer tubes are arranged in two or more rows in a direction crossing the traveling direction of the wind. Therefore, even if the inner diameter or the number of passes is different between the liquid refrigerant side and the gas refrigerant side of the heat transfer tube, the heat transfer tube can be optimally arranged to increase heat exchange efficiency and reduce noise.

The heat exchanger according to the ninth aspect of the present invention is the heat exchanger according to any one of the first to eighth aspects, wherein the heat exchanger has a J-shape, an L-shape, or a U-shape. The liquid refrigerant side and the gas refrigerant side are different in at least one of the inner diameter or the number of passes, so that the heat exchange capacity is improved and the liquid refrigerant side has a J-shape, L-shape or U-shape. Therefore, the structure is compact.

The heat exchanger according to the tenth aspect of the present invention is the heat exchanger according to any one of the first to ninth aspects, wherein the inner peripheral surface of the heat transfer tube continuously changes in a conical shape. ,
The pressure loss in the heat transfer tube can be further reduced, and the performance of the heat exchanger can be further improved.

In the heat exchanger according to the eleventh aspect of the present invention, since one end side and the other end side of the heat transfer tube have different total cross-sectional areas of the inner diameter, one end of the heat transfer tube having a larger total cross-sectional area is connected to the gas refrigerant side. To
If the other end of the heat transfer tube having a small total cross-sectional area is connected to the liquid refrigerant side, the same operation and effect as the heat exchanger of the first aspect of the invention can be obtained.

A refrigeration apparatus according to a twelfth aspect of the present invention includes the heat exchanger according to any one of the first to eleventh aspects,
Since the refrigerant is filled with the C32-based refrigerant, the effect of the heat exchanger itself that the pressure loss of the heat exchanger according to any one of claims 1 to 11 is small and the heat exchange efficiency is high, and the HFC32
Since the viscosity of the system refrigerant itself is low, the pressure loss is small, the diameter of the heat transfer tube can be reduced, and the coefficient of performance is high. It can be extremely reduced and can contribute to the prevention of global warming.

According to the heat exchanger of the thirteenth aspect, if one end having a large number of passes is connected to the gas refrigerant and the other end having a small number of passes is connected to the liquid refrigerant, The same operation and effect as the heat exchanger of the invention can be obtained.

According to the heat exchanger of the fourteenth aspect, if one end having a large number of passes is connected to the gas refrigerant and the other end having a small number of passes is connected to the liquid refrigerant, The same operation and effect as the heat exchanger of the present invention can be obtained, and the number of passes can be gradually changed because the number of passes is three or more.

According to the heat exchanger of the fifteenth aspect, the same operation and effect as those of the heat exchanger of the fourth aspect can be obtained.

Further, since the heat exchanger of the present invention uses heat transfer tubes having different inner diameters, the heat transfer tube at one end having a larger inner diameter is connected to the gas refrigerant side, and the heat transfer tube at the other end having a smaller inner diameter is used. If connected to the liquid refrigerant side, the same function and effect as the heat exchanger according to the fifth aspect of the invention can be obtained.

The heat exchanger according to the seventeenth aspect of the present invention has
Since the heat transfer tubes having different inner diameters of more than one kind are used, the heat transfer tube at one end having a larger inner diameter is connected to the gas refrigerant side, and the heat transfer tube at the other end having the smaller inner diameter is connected to the liquid refrigerant side. The same operation and effects as those of the heat exchanger can be obtained, and the inner diameter of the heat transfer tube is three or more, so that the inner diameter can be gradually changed.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of a heat exchanger according to an embodiment of the present invention.

FIG. 2 is a graph showing the relationship between the number of passes and the capacity with respect to the inner diameter of a heat transfer tube for a condenser and an evaporator.

FIG. 3 is a partially sectional perspective view of a heat exchanger according to another embodiment of the present invention.

FIG. 4 is a view showing a heat transfer tube.

FIG. 5 is a view showing a path of a heat transfer tube system.

FIG. 6 is a view showing a heat transfer tube system.

FIG. 7 is a diagram showing an indoor unit.

FIG. 8 is a diagram showing a heat exchanger according to another embodiment of the present invention.

FIG. 9 is a circuit diagram of an air conditioner according to another embodiment of the present invention.

[Explanation of symbols]

1,10,53,60,93,95 Heat exchanger 11,12,13,14,15,16,20,31,3
2,33,34,41,42,43,45,46,5
5, 56, 57, 58 heat transfer tubes 54, 81, 82, 83, 84 fins 61, 62, 63, 64 blocks

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Masaaki Kitazawa 1000 Oya, Okamotocho, Kusatsu-shi, Shiga 2 Daikin Industries, Ltd. Shiga Works F-term (reference) 3L051 BE10

Claims (17)

[Claims] 1. A heat transfer tube (16, 31, 41,
A heat exchanger characterized in that the total cross-sectional area of the inner diameter of the heat transfer tubes (11, 34, 46, 58, 74) on the gas refrigerant side is smaller than the total cross-sectional area of the inner diameter of the heat transfer pipes (55, 71). 2. The heat exchanger according to claim 1, wherein an inner diameter of the heat transfer tube on the liquid refrigerant side is equal to an inner diameter of the heat transfer tube on the gas refrigerant side. A heat exchanger characterized by being smaller than the inner diameter. 3. The heat exchanger according to claim 1, wherein
A heat exchanger, wherein the heat transfer tubes (11, 16, 55, 58) have the same number of passes on the liquid refrigerant side and the gas refrigerant side. 4. The heat exchanger according to claim 1, wherein
The heat exchanger wherein the heat transfer tubes (31, 34) have a smaller number of passes on the liquid refrigerant side than a number of passes on the gas refrigerant side. 5. A heat transfer tube (16, 41, 55,
71) has a heat transfer tube (11, 46, 5) on the gas refrigerant side.
8, 74) smaller than the inner diameter of the heat exchanger. 6. The heat exchanger according to claim 1, wherein the plurality of fins are provided.
A plurality of blocks (61, 62, 63, 64) each having a heat transfer tube (71, 73, 74, 75) inserted therein, and at least two of the plurality of blocks (61, 62, 63, 64) are provided. The heat exchanger wherein the fins of the blocks differ from each other in at least one of a fin pattern and a fin width. 7. The heat exchanger according to claim 1, wherein the plurality of fins (54) are connected to the heat transfer tubes (55, 5).
6, 57, 58) through which only one block is inserted. The plurality of fins (54) have substantially the same outer peripheral shape and at least one of the plurality of fins (54). A heat exchanger wherein two fins have different fin patterns. 8. The heat exchanger according to claim 1, wherein the heat transfer tubes (55, 57, 56, 58, 7)
3, 74, 75) are arranged in two or more rows in a direction crossing the wind traveling direction. 9. The heat exchanger according to claim 1, wherein the heat exchanger has a J-shape, an L-shape, or a U-shape. 10. The heat exchanger according to claim 1, wherein an inner peripheral surface of the heat transfer tube continuously changes in a conical shape. 11. A heat exchanger wherein the number of passes of the heat transfer tubes on the liquid refrigerant side is smaller than the number of passes of the heat transfer tubes on the gas refrigerant side. 12. A refrigeration apparatus comprising the heat exchanger (93, 95) according to claim 1 and filled with an HFC32-based refrigerant. 13. The heat exchanger, wherein the number of passes of the heat transfer tube is different between one end and the other end of the refrigerant inlet / outlet of the heat exchanger. 14. The heat exchanger according to claim 13, wherein the number of passes of the heat transfer tube is three or more. 15. A heat exchanger characterized in that one end side and the other end side of the heat transfer tube have different total inner cross-sectional areas. 16. A heat exchanger using heat transfer tubes having different inner diameters. 17. A heat exchanger using three or more types of heat transfer tubes having different inner diameters.