JPH05180537A - Condenser - Google Patents

Abstract

PURPOSE:To provide a condenser which can be able to provide refrigerant fluid with specified supercooling while reducing the manufacturing cost. CONSTITUTION:A heat transfer pipe having a greater fluid dropping performance is employed as an upper cooling pipe 21 disposed on a reference fluid surface, and a heat transfer pipe having a greater heat transfer area such as a fin tube is used as a lower cooling tube 22 disposed below the reference fluid surface. Hereby, the number of heat transfer tubes used and having an expensive fluid dropping performance is reduced to reduce the fabrication cost of a condenser.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a condenser having a plurality of cooling pipes.

[0002]

2. Description of the Related Art Conventionally, this type of condenser is disclosed, for example, in Japanese Examined Patent Publication No.
As disclosed in JP-A-0-51024, a plurality of cooling pipes are arranged in a condenser body having an inlet for refrigerant gas on the upper side and an outlet for refrigerant liquid on the lower side. It is known that the liquid level in the condenser body is controlled to supercool the refrigerant liquid passing through the condenser body. As the cooling pipe used as described above, for example, as shown in Japanese Patent Publication No. 60-11800, and as shown in FIG. 3, a spiral fin B is integrally formed on the outer peripheral portion of the pipe A. At the same time, a cut D is formed in the fin B in a direction opposite to the lead angle through a cutter C to increase the effective heat transfer area of the pipe A by the fin B, and a cut provided in the fin B. D
Then, in the gas condensation region, the liquid film thickness of the refrigerant liquid adhering to the outer peripheral portion of the pipe A is reduced to improve the liquid drop performance, and the heat exchange efficiency in the gas condensation region is increased to enhance the condensation capacity. There is.

[0003]

However, the heat transfer tube provided with the fin B on the outer peripheral portion of the tube A and the cut D formed on the fin B as described above can improve the condensing performance but is expensive. Therefore, when such a heat transfer tube is used as all the cooling tubes arranged in the condenser body, the manufacturing cost of the condenser becomes very high, and when supercooling is applied,
According to the above-mentioned structure of the heat transfer tube immersed in the liquid, since the flow rate of the refrigerant liquid is very low and the heat transfer area is small, heat exchange between the refrigerant liquid and the cooling liquid flowing through the heat transfer tube can be sufficiently performed. Therefore, there is a problem that it is difficult to provide supercooling in a limited heat transfer tube length.

The present invention has been made in view of the above problems, and an object thereof is to reduce the manufacturing cost.
An object of the present invention is to provide a condenser capable of applying a predetermined supercooling to a refrigerant liquid.

[0005]

In order to achieve the above object, in the present invention, a plurality of cooling pipes 2 are arranged, an inlet portion 3 for a refrigerant gas is provided at an upper portion, and an outlet portion 4 for a refrigerant liquid is provided at a lower portion. Upper cooling pipe 2 disposed on the reference liquid surface in the condenser
1 is a heat transfer tube having a large liquid drop performance, and the lower cooling pipe 22 arranged below the reference liquid surface is a heat transfer tube having a large heat transfer area.

As the lower cooling pipe 22, it is preferable to use a fin tube in which fins 22a are continuously provided on the outer circumference.

The reference liquid level is the liquid level at which the maximum cooling capacity is obtained.

[0008]

As described above, as the lower cooling pipe 22 arranged below the reference liquid surface, a heat transfer pipe having fins or the like and having a large heat transfer area is used, and the upper cooling portion arranged above the reference liquid surface is used. By using a heat transfer tube having a large liquid drop performance as the tube 21, it is possible to reduce the number of expensive heat transfer tubes to be used, and the manufacturing cost of the condenser can be reduced accordingly.
Further, the upper cooling pipe 21 having a large liquid drop performance on the reference liquid surface
By disposing the cooling pipe 21, the refrigerant liquid adhering to the outer peripheral portion of the cooling pipe 21 positively drops, the condensing performance of the cooling pipe 21 is enhanced, and a fin or the like is provided below the reference liquid surface. By disposing the lower cooling pipe 22 having a large heat transfer area, good heat exchange efficiency can be obtained, and the refrigerant liquid can be subjected to predetermined supercooling.

Further, by using as the lower cooling pipe 22 a fin tube in which fins 22a are continuously provided on the outer periphery, the heat exchange efficiency of the lower cooling pipe 22 below the reference liquid surface can be enhanced.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The condenser shown in FIG. 1 has a plurality of cooling pipes 2 arranged inside a condenser body 1 and the condenser body 1
The refrigerant gas inlet 3 is provided on the upper side and the refrigerant liquid outlet 4 is provided on the lower side to condense the refrigerant gas flowing from the inlet 3 and also cool the refrigerant liquid accumulated in the condenser body 1. I am trying. The height of the liquid surface a shown in FIG. 1 indicates a reference liquid surface that is determined by design conditions (standard conditions) such as temperature, flow rate and compression function of the cooling water, and the maximum cooling capacity (rated capacity) can be obtained. At the liquid level, the cooling pipe 2 located below the reference liquid level can provide necessary supercooling at the maximum cooling capacity.
In the normal case, when the cooling capacity becomes smaller, the amount of refrigerant held in the evaporator increases, so that the liquid level becomes lower than the reference liquid level. However, in this case, the expansion valve capacity is small,
Since the required degree of supercooling is also small, this is not a problem.

In the above condenser, however, a heat transfer tube having a large liquid drop performance is used as the upper cooling pipe 21 arranged on the upper side of the reference liquid surface a in the condenser body 1.
Further, a heat transfer tube having a large heat transfer area is used as the lower cooling tube 22 arranged on the lower side of the reference liquid surface a.

As the upper cooling pipe 21 having a large liquid drop performance arranged on the reference liquid surface a of the condenser body 1, for example, a heat transfer pipe as shown in FIG. 3 is used, and this heat transfer pipe is cooled to the upper part. By disposing the pipe 21 in the gas condensing area formed on the reference liquid surface a of the condenser body 1, the refrigerant liquid adhering to the outer peripheral portion of the cooling pipe 21 due to heat exchange is positively downward. The cooling performance of the cooling pipe 21 is enhanced by being dropped.

Further, as the lower cooling pipe 22 having a large heat transfer area, which is disposed below the reference liquid surface a of the condenser body 1,
For example, as shown in FIG. 2, a fin tube having spirally connected fins 22a on the outer circumference is used, and the fin tube is formed below the reference liquid surface a of the condenser body 1. By arranging in the supercooling region of the refrigerant liquid, good heat exchange efficiency can be obtained, and in combination with the improvement of the condensing performance on the side of the upper cooling pipe 21, the refrigerant liquid is given a predetermined supercooling. Further, since the fin tube used as the lower cooling pipe 22 is relatively inexpensive, it is possible to reduce the manufacturing cost of the entire condenser, and as the upper cooling pipe 21, for example, a needle-like projection is formed in the longitudinal direction. When a heat transfer tube provided in series along the heat transfer tube is used, the heat transfer tube having the needle-shaped projections is also inexpensive, so that the manufacturing cost of the entire condenser can be further reduced.

That is, while considering the cost, by using a tube having a high condensing performance for condensing the gas refrigerant and a tube having a high heat exchange efficiency with the refrigerant liquid above and below the reference liquid level a, the entire condenser can be obtained. It is possible to add supercooling while reducing the manufacturing cost of.

Further, the upper cooling pipe 21 having a large liquid drop performance is not limited to the heat transfer pipe as shown in FIG. 3, but, for example, a saw-toothed projection having an hourglass-shaped side surface on the outer surface. It is also possible to use a plurality of heat transfer tubes integrally provided, and this heat transfer tube is expensive, but this expensive heat transfer tube is not arranged in the entire condenser main body 1 but Since it is arranged only on the upper side of the reference liquid surface a of the main body 1,
The manufacturing cost of the condenser as a whole can be reduced as compared with the conventional one.

Further, as the lower cooling pipe 22, in addition to the fin tube described above, for example, a corrugated tube having an uneven surface formed on its outer peripheral surface can be used.

[0017]

As described above, in the condenser of the present invention, a heat transfer tube having a large liquid drop performance is used as the upper cooling pipe 21 arranged above the reference liquid surface, and the condenser is arranged below the reference liquid surface. Since the heat transfer tube having a large heat transfer area is used as the lower cooling tube 22 to be installed, the number of expensive heat transfer tubes having a large liquid drop performance can be reduced, and the manufacturing cost can be reduced. Predetermined supercooling can be surely provided.

Further, as the lower cooling pipe 22, by using a fin tube in which fins 22a are continuously provided on the outer periphery, the heat exchange efficiency of the lower cooling pipe 22 below the liquid surface can be enhanced.

[Brief description of drawings]

FIG. 1 is a sectional view schematically showing a condenser according to the present invention.

FIG. 2 is a partial vertical cross-sectional view of a fin tube.

FIG. 3 is a partially cutaway front view of a high-performance heat transfer tube conventionally used for the entire condenser.

[Explanation of symbols]

 2 Cooling pipe 21 Upper cooling pipe 22 Lower cooling pipe 3 Inlet part 4 Outlet part

Claims (2)

[Claims] 1. A condenser having a plurality of cooling pipes 2, an inlet portion 3 for a refrigerant gas provided at an upper portion, and an outlet portion 4 for a refrigerant liquid provided at a lower portion, the condenser being provided on a reference liquid surface. Upper cooling pipe 21
Is a heat transfer tube having a large liquid drop performance, and the lower cooling pipe 22 arranged below the reference liquid surface is a heat transfer tube having a large heat transfer area. 2. The condenser according to claim 1, wherein the lower cooling pipe 22 discharges a fin tube in which fins 22a are continuously provided on the outer circumference.