JPH10176897A - Horizontal condenser - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize a condenser wherein deterioration of a condensation characteristic is difficult to happen owing to a condensed fluid adhering to a heat transfer pipe. SOLUTION: A condenser 1 includes a heat transfer tube 3 disposed in a container 2. The heat transfer tube 3 comprises a series of tubular members and includes a plurality of horizontally extending main part 6 coupled with each other through a coupling part 7 and disposed at an interval longitudinally. Such a coupling tube 3 includes a water repulsion layer on an outer periphery surface, and once condensable gas such as steam touches the outer periphery surface and is condensed, the gas becomes rapidly droplets and falls because of a water repulsing property of the outer periphery surface. The condensate formed in the main part 6 on a lower side of the heat transfer tube 3 collides the condensate falling from an upper portion and is effecutally shaken down from the heat transfer tube 4 because of the outer periphery surface of the coupling pipe 3 being water replusive.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a condenser, and more particularly to a horizontal condenser for cooling and condensing a condensable gas.

[0002]

2. Description of the Related Art Condensers used in absorption-type and compression-type refrigerators, condensers, electric refrigerators, heat pump electric heaters, etc. are usually used for cooling condensable gas such as water vapor. It has a heat transfer tube. The heat transfer tube is a tubular member mainly formed of a material having high thermal conductivity, for example, copper, and is configured such that a coolant such as cooling water can circulate therein. Such a heat transfer tube is cooled by a coolant whose outer peripheral surface circulates inside. As a result, the condensable gas is cooled when it touches the outer peripheral surface, and is condensed there.

In the above-described heat transfer tubes, condensed liquid formed by condensing condensable gas often forms a film and adheres to the outer peripheral surface. The condensed liquid adhered to the outer peripheral surface of the heat transfer tube impedes heat transfer between the heat transfer tube and the condensable gas, and causes a reduction in the condensation characteristics of the condensable gas by the heat transfer tube. In particular, in the case of a condenser in which the heat transfer tubes extend in the horizontal direction and are arranged in multiple stages in the vertical direction with an interval, the film thickness of the condensed liquid adhering to the surface of the lower heat transfer tube is higher than that of the upper heat transfer tube. The heat transfer resistance of the lower heat transfer tube is increased by the condensed liquid attached thereto, and the condensed liquid is easily reduced due to the condensed liquid dropped from the heat transfer tube.

[0004] An object of the present invention is to realize a condenser in which the condensed liquid adhering to the heat transfer tube is unlikely to deteriorate the condensation characteristics.

[0005]

SUMMARY OF THE INVENTION A horizontal condenser according to the present invention is for cooling and condensing a condensable gas. The horizontal condenser includes a heat transfer tube having a water-repellent layer on an outer peripheral surface for cooling and condensing a condensable gas. The heat transfer tubes extend in the horizontal direction and are provided in multiple stages in the vertical direction at intervals. In such a condenser, the water-repellent layer of the heat transfer tube is, for example, a thin film in which a water-repellent polymer is dispersed and mixed in a metal matrix.

Another horizontal condenser according to the present invention is for cooling and condensing a condensable gas. This horizontal condenser cools the condensable gas and condenses it.
A series of heat transfer tubes having a water-repellent layer on the outer peripheral surface are provided. The heat transfer tube has a plurality of main parts extending in the horizontal direction and arranged in parallel with each other at intervals in the vertical direction, and a connecting part for connecting the main parts adjacent to each other.

[0007] Still another horizontal condenser according to the present invention comprises:
This is a horizontal condenser for cooling and condensing condensable gas. The horizontal condenser includes a series of heat transfer tubes having a water-repellent layer on an outer peripheral surface for cooling and condensing a condensable gas. The heat transfer tube is formed in a coil shape whose axis is vertical.

[0008]

In the horizontal condenser according to the present invention, the condensable gas is cooled and condensed on the outer peripheral surface of the heat transfer tube. The condensed liquid formed at this time quickly becomes droplets because the outer peripheral surface of the heat transfer tube has a water-repellent layer, and easily falls from the heat transfer tube.
In particular, of the heat transfer tubes provided in multiple stages, the condensate formed on the outer peripheral surface of the lower heat transfer tube is a condensate that falls from the upper heat transfer tube because the surface of the heat transfer tube is water repellent. Since it is easy to be hit off by collision, it is hard to remain in the heat transfer tube. As a result, the heat transfer tube hardly causes an increase in heat transfer resistance due to adhesion of the condensed liquid, and can maintain good condensation characteristics of the condensable gas.

In another horizontal condenser according to the present invention, the condensable gas is cooled and condensed on the outer peripheral surface of the heat transfer tube. The condensed liquid formed at this time quickly becomes droplets because the outer peripheral surface of the heat transfer tube has a water-repellent layer, and easily falls from the heat transfer tube. In particular, the condensate formed on the outer peripheral surface of the lower main portion of the plurality of main portions constituting the heat transfer tube, which are arranged in parallel with each other, collides with the condensate falling from the upper main portion. It is easy to be wiped off, so it hardly remains in the heat transfer tube. As a result, the heat transfer tube hardly causes an increase in heat transfer resistance due to adhesion of the condensed liquid, and can maintain good condensation characteristics of the condensable gas.

In still another horizontal condenser according to the present invention, the condensable gas is cooled and condensed on the outer peripheral surface of the heat transfer tube. The condensed liquid formed at this time quickly becomes droplets because the outer peripheral surface of the heat transfer tube has a water-repellent layer, and easily falls from the heat transfer tube. In particular, in a heat transfer tube in which the axis is formed in the shape of a coil having a vertical direction, the condensate formed on the outer peripheral surface of the lower portion is liable to collide with the condensate falling from the outer peripheral surface of the upper portion and be easily wiped off. , Hardly remains in the heat transfer tube. As a result, the heat transfer tube hardly causes an increase in heat transfer resistance due to adhesion of the condensed liquid, and can maintain good condensation characteristics of the condensable gas.

[0011]

FIG. 1 shows a condenser according to an embodiment of the present invention. In the figure, a condenser 1 comprises a container 2
And a heat transfer tube 3.

The container 2 has an inlet 4 for introducing a condensable gas such as water vapor at an upper portion, and an outlet 5 for discharging a condensed liquid obtained by condensing the condensable gas. It is formed on the bottom.

The heat transfer tube 3 is made up of a series of tubular members arranged in the container 2 and has a plurality of main parts 6 extending in the horizontal direction. The plurality of main parts 6 are arranged in the container 2 in parallel with each other with a constant interval in the vertical direction (up and down direction). Adjacent main parts 6 are mutually connected by a connection part 7. In such a heat transfer tube 3, one end 3 a extends from the lower part of the container 2 to the outside, and the other end 3 b extends from the upper part of the container 2 to the outside.

The heat transfer tube 3 preferably has five or more main portions 6. When the number of the main parts 6 is less than five, the condensed liquid on the surface of the heat transfer tube 3 may be difficult to drop efficiently according to the operation described later. Also, the interval X between the main parts 6
Is usually preferably set to 2 to 50 mm, and 3 to 50 mm.
More preferably, it is set to 20 mm. This interval is 2m
If it is less than m, the condensed liquid may be in a bridging state between the upper and lower main parts 6 and may not be easily dropped. Conversely, 50mm
Is exceeded, the density of the main part 6 decreases, so that the condenser 1
Becomes large.

The above-described heat transfer tube 3 is made of a metal material having a high thermal conductivity such as, for example, copper. As shown in FIG. It has a channel 8 for circulation. A water-repellent layer 9 is formed on the outer peripheral surface of the heat transfer tube 3. It should be noted that the thickness of the water-repellent layer 9 is emphasized in FIG.

The water-repellent layer 9 is a thin-film plating layer in which particles of a water-repellent polymer are dispersed and mixed in a metal matrix.
Here, as the water-repellent polymer, for example, a fluorine-containing polymer, a chain fatty acid, a silicone resin, and the like are preferably used. In particular, a fluorine-containing polymer is preferably used. Examples of the fluorine-containing water-repellent polymer include tetrafluoroethylene polymer (PTFE), tetrafluoroethylene-fluoroalkylvinylether copolymer (PFA) and tetrafluoroethylene-
Examples include fluorine-based resins such as hexafluoropropylene copolymer (FEP), pitch fluoride, and graphite fluoride. The average particle size of such water-repellent polymer particles is preferably 5 μm or less, particularly preferably 2 μm or less.
When the average particle size exceeds 5 μm, the water-repellent polymer particles may be difficult to be uniformly dispersed in the metal matrix, and the water-repellent polymer particles may easily fall off from the water-repellent layer 9. is there.

On the other hand, as the metal constituting the metal matrix, for example, nickel is preferably used because it has a high adhesion strength and thermal conductivity to copper constituting the heat transfer tube 3 and is relatively inexpensive.

The content of the particles of the water-repellent polymer in the metal matrix is usually 10 to 50% by volume, especially 15% by volume.
~ 40% by volume is preferred. If the content is less than 10% by volume, it may be difficult to impart sufficient water repellency to the water repellent layer 9. As a result, the condensed liquid formed on the surface of the water-repellent layer 9 is less likely to quickly become droplets, and the heat conductivity of the heat transfer tube 3 may be reduced, thereby lowering the cooling efficiency of the condensable gas. Conversely, when the content of the water-repellent polymer particles is 5
If it exceeds 0% by volume, the adhesion between the metal material constituting the heat transfer tube 3 and the water-repellent layer 9 is reduced, and the water-repellent layer 9 may be easily separated from the heat transfer tube 3. Further, the thermal conductivity of the water-repellent layer 9 may be reduced, and the cooling efficiency of the condensable gas may be reduced.

The water-repellent layer 9 has a thickness of 50 μm or less.
In particular, it is preferably set to 10 μm or less and more than the average particle size of the water-repellent polymer particles. This film thickness is 50 μm
If the value exceeds, the uniformity of the particles of the water-repellent polymer in the metal matrix is reduced, and the density of the water-repellent layer 9 is impaired. As a result, the thermal conductivity of the water-repellent layer 9 may be reduced. is there. Even in such a case, since the heat transfer resistance increases in proportion to the film thickness, the heat transfer resistance of the water-repellent layer 9 itself cannot be ignored. Conversely, when the film thickness is less than the average particle size of the water-repellent polymer particles, the water-repellent polymer particles are easily detached from the water-repellent layer 9.

The water-repellent layer 9 can be formed, for example, by a wet method. Specifically, using a plating bath in which a powder of the above-described water-repellent polymer and a solution of the metal constituting the metal matrix are mixed, the outer peripheral surface of the metal material tube constituting the heat transfer tube 3 is subjected to electrolytic plating or non-plating. It can be formed by applying electrolytic plating.

Next, the operation of the condenser 1 will be described. First, a coolant such as cooling water is continuously supplied to the heat transfer tube 3 of the condenser 1 from the end 3a to the end 3b. Thereby, the heat transfer tube 3 is cooled from the inside, and the temperature of the outer peripheral surface of the water-repellent layer 9 decreases. In this state,
When a condensable gas such as water vapor is introduced into the container 2 through the inlet 4, the condensable gas diffuses in the container 2 and touches the heat transfer tube 3 to be cooled. As a result, the condensable gas is condensed and turns into condensed liquid on the outer peripheral surface of the heat transfer tube 3. On this occasion,
Since the outer peripheral surface of the heat transfer tube 3 is formed of the water-repellent layer 9 as described above, the condensed liquid quickly drops and falls quickly from the heat transfer tube 3.

Here, the condensed liquid that has fallen from the main part 6 of the heat transfer tube 3 collides with another main part 6 located below the main part 6. At this time, the condensed liquid adhering to the other main part 6 can be washed away by the condensed liquid that has fallen, and fall from the main part 6 more quickly. In other words, the condensed liquid that has adhered to the lower main portion 6 is efficiently removed by the condensed liquid that has fallen from the upper main portion 6.

As a result, since the condensed liquid is efficiently removed from the outer peripheral surface of the heat transfer tube 3, the condensed liquid hardly adheres to the outer peripheral surface, and the outer peripheral surface is easily in direct contact with the condensable gas. Kept in state. Therefore, the heat transfer tube 3 is less likely to lose its thermal conductivity due to the condensed liquid (in other words, it is difficult to increase the heat transfer resistance due to the adhesion of the condensed liquid), and to maintain a good condensing gas condensation efficiency. Can be.

The condensed liquid that has fallen from the heat transfer tube 3 is discharged from the discharge port 5 of the container 2 to the outside.

[Other Embodiments] (1) In the condenser 1 according to the above-described embodiment, a series of heat transfer tubes 3 are formed by a plurality of main parts 6 and a connecting part 7 connecting the main parts 6. Although configured, the present invention is not limited to this. For example, the heat transfer tubes 3 do not need to be formed in a series like this, and a plurality of (preferably three or more) heat transfer tubes 3 extending in the horizontal direction and independent from each other are arranged at intervals in the vertical direction. In this case, the present invention can be similarly implemented.

(2) A condenser according to still another embodiment will be described with reference to FIG. This condenser 10 has a container 2 configured similarly to the condenser 1 according to the above-described embodiment.
And a coil-shaped heat transfer tube 13 disposed in the container 2.

The coil-shaped heat transfer tube 13 is shown in FIGS.
As shown in (a plan view of the heat transfer tube 13), a tubular member similar to the heat transfer tube 3 employed in the condenser 1 according to the above-described embodiment is wound in a clockwise cylindrical shape. A water-repellent layer similar to the water-repellent layer 9 in the above-described heat transfer tube 3 is formed on the outer peripheral surface (not shown). Such a heat transfer tube 13
The container 2 is set upright so that the axis C is vertical.
And one end 13a extends from the lower part of the container 2 to the outside, and the other end 13b extends from the upper part of the container 2 to the outside.

It is preferable that such a heat transfer tube 13 is formed in a coil shape wound three or more times. 3
In the case of a coil wound less than the weight, the effect obtained by the present invention is reduced. The distance Y (FIG. 3) between tubes constituting the coil is preferably set to about 2 to 20 mm, more preferably about 3 to 20 mm. If this interval is less than 2 mm, the condensed liquid may be in a bridging state between the coils, making it difficult to fall. Conversely, if it exceeds 20 mm, heat transfer tube 1
Since the density of 3 is small, the condenser 10 becomes large.

In such a condenser 10, a coolant such as cooling water is continuously supplied from the end 13a of the heat transfer tube 13 to the end 13b. Thereby, the heat transfer tube 13
Is cooled from the inside, and the temperature of the water-repellent layer provided on the outer peripheral surface decreases. In this state, when a condensable gas such as water vapor is introduced into the container 2 through the inlet 4, the condensable gas diffuses in the container 2 and touches the heat transfer tube 13 to be cooled. As a result, the condensable gas is condensed and turns into a condensed liquid on the outer peripheral surface of the heat transfer tube 13. At this time, the condensed liquid quickly drops into droplets because the outer peripheral surface of the heat transfer tube 3 is formed of the above-described water-repellent layer, and drops quickly from the heat transfer tube 13.

Here, since the heat transfer tubes 13 are arranged upright so that their axes are perpendicular to each other, the condensate that has fallen from the upper portion of the heat transfer tubes 13 condenses on the outer peripheral surface of the lower portion of the heat transfer tubes 13. The liquid collides with the condensed liquid and flushes the condensed liquid. Therefore, the condensed liquid attached to the lower part of the heat transfer tube 13 is efficiently removed by the condensed liquid falling from the upper part of the heat transfer tube 13.

As a result, since the condensed liquid is efficiently removed from the outer peripheral surface of the heat transfer tube 13, the condensed liquid hardly adheres to the outer peripheral surface, and the outer peripheral surface is easily brought into direct contact with the condensable gas. Kept in state. Therefore, the heat transfer tube 13 is less likely to lose its thermal conductivity due to the condensed liquid (in other words, it is difficult for the heat transfer resistance to increase due to the adhesion of the condensed liquid), and to maintain good condensing gas condensation efficiency. Can be.

(3) In the above-described various embodiments, the water-repellent layer 9 disposed on the outer peripheral surface of the heat transfer tubes 3 and 13 is formed by plating a thin film in which particles of a water-repellent polymer are dispersed and mixed in a metal matrix. Although constituted by layers, the present invention is not limited to this. That is, the water-repellent layer 9 only needs to be formed using a material capable of imparting water-repellency to the outer peripheral surfaces of the heat transfer tubes 3 and 13. And a coating layer formed using a water-repellent nonmetal material such as a chain fatty acid and a silicone resin, or a water-repellent metal material such as gold, silver, chromium, rhodium and palladium.

[0033]

EXAMPLES Production Example 1 (Production of Heat Transfer Tube 1) A nickel plating bath comprising 350 g / l of nickel sulfate, 45 g / l of nickel chloride and 40 g / l of boric acid was prepared. 50 parts by weight of fluorinated pitch (FP) fine particles (average particle size = 0.3 μm) obtained from coal tar,
50 parts by weight of fine particles of tetrafluoroethylene-hexafluoropropylene copolymer resin (FEP) (average particle size = 0.2 to 0.3 μm) manufactured by Daikin Industries, Ltd.
Surfactant (trade name “MegaFac F15” manufactured by Dainippon Ink and Chemicals, Inc.) added at a ratio of 30 mg to 1 g of P and at a ratio of 65 mg to 1 g of FEP.
0 ″), the mixture containing FP: FEP: nickel = 1
It was added to the above-mentioned plating bath so that the ratio (weight ratio) was 5:15:70.

Next, a copper tube having an outer diameter of 16 mm, an inner diameter of 14 mm and an effective length of 100 mm was prepared, and the outer peripheral surface of the copper tube was subjected to electrolytic plating using the plating bath described above. At this time, the copper tube was set to the negative electrode, and the liquid temperature was 45 ± 5.
° C, pH = 3.8-4.2 and current density = 3 A / dm
^The plating bath was adjusted with a screw agitator so that the plating film thickness was 2 μm so that the condition ² was maintained.
Thereafter, the copper tube was further heat-treated to obtain a heat transfer tube 1 whose outer peripheral surface was plated.

Production Example 2 (Production of heat transfer tube 2) Fine particles of tetrafluoroethylene copolymer (PTFE) (average particle size = 0.3 μm) manufactured by Daikin Industries, Ltd.
FE: Nickel was added to the nickel plating bath prepared in Production Example 1 so as to have a ratio of 30:70 (weight ratio).
Further, the same surfactant as used in Production Example 1 was added to PT
FE was added to the nickel plating bath at a rate of 30 mg per 1 g.

Next, a copper tube similar to that used in Production Example 1 was prepared, and this copper tube was subjected to plating treatment under the same conditions as in Production Example 1 using the above-described plating bath. Thereafter, the copper tube was further heat-treated to obtain a heat transfer tube 2 whose outer peripheral surface was plated.

Example 1 While maintaining the heat transfer tubes 1 obtained in Production Example 1 horizontally, three tubes were arranged side by side in a vacuum vessel with a vertical interval of 10 mm to constitute a condenser. Each heat transfer tube 1 has
The cooling water was set to flow independently and continuously.

Example 2 A condenser was constructed in the same manner as in Example 1 except that six heat transfer tubes 1 obtained in Production Example 1 were used.

Example 3 A condenser similar to that of Example 1 was constructed using three heat transfer tubes 2 obtained in Production Example 2.

Example 4 A condenser similar to that of Example 2 was constructed using six heat transfer tubes 2 obtained in Production Example 2.

Comparative Example 1 A condenser similar to that of Example 1 was constructed by using three copper tubes (not plated) used in Production Example 1 as heat transfer tubes.

COMPARATIVE EXAMPLE 2 A condenser similar to that of Example 1 was constructed using six copper tubes (not plated) used in Production Example 1 as heat transfer tubes.

With respect to the condensers obtained in Evaluation Examples 1 to 4 and Comparative Examples 1 and 2, the degree of vacuum in the vacuum vessel was set to 0.01 Torr or less, and cooling water was continuously supplied to each heat transfer tube. . In this state, pure steam having an absolute pressure of 1 kg / cm ² was introduced into the vacuum vessel. The condensed water thus obtained was received by a tray installed at the bottom of the vacuum vessel, and the amount of the condensed water was measured using a balance to examine the condensation characteristics of each condenser. Table 1 shows the results
Shown in

[0044]

[Table 1]

From Table 1, it can be seen that, in the case of the embodiment, as the number of heat transfer tubes increases, the overall heat transfer coefficient indicating the condensation characteristics increases. On the other hand, in the case of the comparative example, the larger the number of heat transfer tubes, the smaller the overall heat transfer coefficient indicating the condensation characteristics. From this, it can be seen that in the condenser according to the example, the condensate adhering to the heat transfer tube hardly causes the deterioration of the condensation characteristics.

[0046]

According to the horizontal condenser of the present invention, since the outer peripheral surface of the heat transfer tube has a water-repellent layer and the heat transfer tube is arranged as described above, the condensation by the condensed liquid adhering to the heat transfer tube is achieved. Deterioration of characteristics is unlikely to occur.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a condenser according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along line II-II of FIG.

FIG. 3 is a longitudinal sectional view of a condenser according to another embodiment of the present invention.

FIG. 4 is a plan view of a heat transfer tube employed in a condenser according to another embodiment.

[Explanation of symbols]

 1,10 Condenser 3,13 Heat transfer tube 6 Main part 7 Connecting part 9 Water repellent layer

Claims (4)

[Claims] 1. A horizontal condenser for cooling and condensing a condensable gas, comprising a heat transfer tube having a water-repellent layer on an outer peripheral surface for cooling and condensing the condensable gas, A horizontal condenser in which the heat transfer tubes extend in the horizontal direction and are provided in multiple stages in the vertical direction with intervals. 2. The horizontal condenser according to claim 1, wherein the water-repellent layer is a thin film in which a water-repellent polymer is dispersed and mixed in a metal matrix. 3. A horizontal condenser for cooling and condensing a condensable gas, comprising a series of heat transfer tubes having a water-repellent layer on an outer peripheral surface for cooling and condensing the condensable gas. The heat transfer tube has a plurality of main portions extending in the horizontal direction and arranged in parallel with each other at intervals in the vertical direction, and a connecting portion for connecting the main portions adjacent to each other. A horizontal condenser. 4. A horizontal condenser for cooling and condensing a condensable gas, comprising a series of heat transfer tubes having a water-repellent layer on an outer peripheral surface for cooling and condensing the condensable gas. The horizontal condenser, wherein the heat transfer tube has an axis formed in a coil shape with a vertical direction.