KR100564877B1 - Composition for ultra hydrophilicity, hydrophilic heat exchanging pipe and method for coating hydrophilic film - Google Patents

Abstract

The present invention relates to a superhydrophilic coating composition and a coating method thereof, thereby providing a superhydrophilic heat transfer tube. After the metal oxide sol is prepared by varying the particle size distribution, it may be coated on at least one or more times on the surface of the heat pipe to prepare a superhydrophilic heat pipe having excellent hydrophilicity and durability. Therefore, the thermal efficiency of the refrigerating device and the heating device can be further maximized.

Super hydrophilic coating, metal oxide sol, heat pipe

Description

Superhydrophilic coating composition, superhydrophilic heat pipe and coating method thereof {COMPOSITION FOR ULTRA HYDROPHILICITY, HYDROPHILIC HEAT EXCHANGING PIPE AND METHOD FOR COATING HYDROPHILIC FILM}

1 is a schematic diagram showing the configuration of a typical refrigeration apparatus.

2A is a perspective view showing an example of a heat transfer pipe.

Figure 2b is a photograph showing the groove of the grid pattern formed on the surface of the heat pipe.

Figure 3a is a photograph showing the results of the contact angle test of the coating tube without a coating.

Figure 3b is a photograph showing the contact angle test results of the hydrophilic coated heat pipe according to the present invention.

The present invention relates to a superhydrophilic coating composition, a superhydrophilic heat exchanger tube and a coating method thereof, by providing a hydrophilic function by coating the superhydrophilic composition on the surface of a heat exchanger pipe used in an evaporator, an absorber, a regenerator, etc. of a refrigerating device or a heating device. Significantly improve the thermal efficiency of refrigeration or heating systems.

The superhydrophilic coating composition according to the invention is particularly suitable for the hydrophilic coating of evaporator heat transfer tubes of absorption chillers.

Absorption refrigerator is a refrigerator using the liquid solubility of refrigerant gas according to temperature and pressure, and has an absorber and a regenerator instead of a compressor of a vapor compression refrigerator, using water or ammonia as a refrigerant, and a lithium bromide solution as a solution. Or water is mainly used. In the absorption refrigerator, the refrigerant is absorbed in the concentrated solution without mechanically compressing the compressor, and the lean solution formed is sent to the regenerator by a pump. In the regenerator, the lean solution is separated back into steam as it is heated, and the refrigerant is condensed in the condenser and then sent to the evaporator. In general, the pressure in the evaporator is a vacuum state, and water as a refrigerant flows in the tube of the heat transfer tube, and distilled water is dispersed as a refrigerant outside the tube. The water in the tube is cooled by the latent heat of evaporation of the refrigerant vapor generated as the refrigerant outside the tube is evaporated. It is supplied to an air conditioner in cold water.

FIG. 1 is a view schematically showing a configuration and a refrigeration cycle of a general absorption chiller. As shown in the drawings, a conventional absorption chiller includes a high temperature regenerator 1 and a low temperature regenerator 2 for heating a refrigerant, and these high temperature regenerators 1. ) And a condenser (3) for condensing and liquefying the refrigerant sent from the low temperature regenerator (2), and an evaporator (4) for absorbing the surrounding heat of the refrigerant condensed and condensed by the condenser (3) and evaporating it into steam at low and low pressure. And an absorber (5) for absorbing refrigerant vapor evaporated by the evaporator (4) into the solution, a low temperature solution heat exchanger (6) and a high temperature solution heat exchanger (7) for exchanging the solution. (8) has a structure interconnected by each other, inside the evaporator (4) and the absorber (5) is carried through the heat pipes (9a) (9b) and the respective piping (8) through which cold water and cooling water flow, respectively. Injectors for spreading refrigerant or solution 0a) and 10b are provided, respectively.

In addition, the absorption chiller includes a refrigerant pump 11 for pumping refrigerant from the lower part of the evaporator 4 and transferring the refrigerant to the injector 10a, a shutoff valve 12 for bypassing the refrigerant to the absorber 5, and A solution circulation pump 13 for pumping an aqueous lithium embrittlement (LiBr) solution from the lower part of the absorber (5) to the high temperature regenerator (1) and the low temperature regenerator (2) side, and the solution circulating pump (13) The solution spray pump 14 which injects a solution to the absorber 5 side is provided.

The evaporator 4 and the absorber 5 are provided in contact with each other, and an eliminator 15 is disposed therebetween so that the evaporator 4 and the absorber 5 can communicate with each other. In general, the role of the eliminator 15 in the absorption chiller allows only the refrigerant vapor evaporated in the evaporator 4 to flow to the absorber 5 side, while spraying in the absorber 5 to effectively absorb the refrigerant vapor. By preventing the solution to be infiltrated into the evaporator 4, the refrigerant in the evaporator 4 is contaminated to prevent the evaporation capacity from being sharply reduced. In other words, the eliminator 15 facilitates the movement of the refrigerant vapor, while blocking the absorption solution in the absorber 5 from entering the evaporator 4.

As described above, the cold water used for absorption cooling passes through the heat transfer pipe 9a in the evaporator 4 to be deprived of heat by the latent heat of evaporation of the refrigerant, and the refrigerant vapor evaporated in the evaporator 4 is cooled. The heat of absorption flows into the absorber 5 and is dispersed in the tube outer surface of the heat transfer tube 9b and absorbed by the concentrated solution in the absorber 5, and the heat of absorption generated when absorbing the refrigerant vapor is supplied into the tube of the heat transfer tube 9b. The rich solution in the absorber 5 is always kept at a constant temperature as it is removed by the cooled cooling water. The concentrated solution in the absorber (5) absorbing the refrigerant vapor is diluted to produce a dilute action, which becomes a lean solution, which is pumped by the solution circulation pump (13) to pass through the low temperature solution heat exchanger (6) After being preheated by the high temperature solution recovered from (1) and the low temperature regenerator (2), it is divided into two parts, partly introduced into the low temperature regenerator (2), and the other part is passed through the high temperature solution heat exchanger (7). Flows into 1). The solution introduced into the high temperature regenerator 1 is heated by combustion gas, steam or the like supplied from the heating means 17 to form a high temperature concentrated solution while generating a high temperature refrigerant vapor.

The water level of the solution in the high temperature regenerator 1 is controlled by using a known float valve 16 provided in the high temperature regenerator 1, and this float valve 16 has a large flow rate in the high temperature regenerator 1 The opening degree of the inlet pipe 21 is gradually reduced, and when the inflow flow rate is small, the opening degree of the inlet pipe 21 is gradually enlarged to automatically maintain the level of the solution in the high temperature regenerator 1. Controlled.

On the other hand, the lean solution entering the low temperature regenerator (2) is heated by the refrigerant vapor generated by the high temperature regenerator (1) and is concentrated to a solution of medium concentration while generating a refrigerant vapor, the high temperature regenerator (1) The concentrated hot concentrated solution is discharged through the outlet pipe 22, passed through the hot solution heat exchanger 7, and then mixed with the intermediate solution refluxed from the cold regenerator 2 to be mixed with the cold solution heat exchanger 6 It is withdrawn to the absorber 5 side through. At this time, the recovered solution is pumped by the solution spray pump 14 and injected into the absorber 5 through the injector 10b.

The high temperature regenerator 1 heats the solution inside the high temperature regenerator 1 by the heating means 17 to generate refrigerant vapor, and the generated refrigerant vapor is used as a heat source for heating the low temperature regenerator 2. . The refrigerant used for heating the low temperature regenerator 2 and the refrigerant generated in the low temperature regenerator 2 are cooled by the cooling water in the condenser 3 and condensed. The refrigerant condensed in the condenser 3 is subjected to the gravity and pressure difference. The condensation refrigerant introduced into the evaporator (4), the condensation refrigerant introduced from the condenser (3) to the evaporator (4) is pumped again by the refrigerant pump (11) in a state filled up to a constant refrigerant level to the evaporator (10a) through the injector (10a) 4) It is sprayed inside to obtain cold water required for cooling. In addition, some of the refrigerant liquid injected through the injector (10a) is evaporated to move through the eliminator 15 to the absorber (5), the remaining refrigerant liquid is collected at the bottom of the evaporator (4) again the refrigerant pump (11) Is inhaled.

In order to increase the thermal efficiency in such a refrigerator, various conditions must be well equipped, in particular, the heat exchange characteristics of the heat exchanger is important, and among them, the evaporation capacity of the heat transfer tube of the evaporator is very important.

As described above, the heat transfer tube in the evaporator evaporates the refrigerant (mainly water) transferred from the condenser to the absorber by heat exchange with the cooling water flowing in the heat transfer tube, and sends it to the absorber again. The heat exchange capacity varies greatly depending on the hydrophilicity.

Conventionally, in order to improve the heat exchange efficiency, efforts have been made to improve the thermal efficiency by maximizing the adsorption and evaporation of water in the heat transfer tubes to which hydrophilicity is formed by forming an iron oxide film on the heat transfer tube surface of the evaporator. Gases are generated in the interior, reducing the adsorption and evaporation efficiency of moisture.

Accordingly, an object of the present invention is to further improve the heat exchange characteristics of the heat transfer tubes in the evaporator of the refrigerating device or the heating device.

Another object of the present invention is to provide a hydrophilic coating composition that can be applied to all devices in which heat exchange occurs, such as an evaporator, a condenser, and an absorber.

Another object of the present invention is to provide a hydrophilic heat transfer tube excellent in durability, corrosion resistance and thermal shock.

Other objects and features of the present invention will become apparent from the following detailed description and claims.

In order to achieve the above object, the present invention is a general formula R ¹ _a Si (OR ² ) _4-a (wherein R ¹ and R ² are each independently a hydrocarbon having 1 to 6 carbon atoms, a is 0 to 3 20 to 75% by weight of a hydrolyzate or partial condensate of an organosilane represented by an integer) and at least one metal oxide selected from TiO ₂ , SiO ₂ , SnO ₂ , ZnO, ZrO ₂ , WO ₃ and V ₂ O ₅ . A sol solution composed of about 80% by weight; 50 to 200 parts by weight of alcohol having 1 to 4 carbon atoms based on 100 parts by weight of the sol solution, wherein the sol solution includes a particulate sol and a polymeric sol having different particle diameter distributions of metal oxide particles. It provides a super hydrophilic coating composition, characterized in that made of polymeric sol).

The organosilane may be methyltrimethoxysilane, methyltriethoxysilane, tetramethoxysilane, tetraethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, phenyltriethoxysilane, phenyltrimethoxysilane, diphenyl Dimethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, any one or more materials selected from, and the alcohol is any one or more materials selected from methanol, ethanol, butanol, isopropyl alcohol and these materials are illustrative Only listed and various other materials can be used.

The composition may also contain a silane containing an amino group, such as aminopropyltrimethoxysilane, aminopropyltriethoxysilane, aminopropylmethyldimethoxysilane, in order to maintain durability with hydrophilicity, in particular to express hot water resistance. Etc. may be additionally included in the main matrix, and may further include any one or more materials selected from Pt, Au, Ag, or Pd as a thermosetting catalyst in the range of 0.1 to 5%.

In addition, the present invention is represented by the general formula R ¹ _a Si (OR ² ) _4-a (wherein R ¹ and R ² are each independently hydrocarbon having 1 to 6 carbon atoms, a is an integer of 0 to 3) 20 to 75% by weight of the hydrolyzate or partial condensate of the organosilane and 25 to 80% by weight of at least one metal oxide selected from TiO ₂ , SiO ₂ , SnO ₂ , ZnO, ZrO ₂ , WO ₃ and V ₂ O ₅ A sol solution composed of a particulate sol and a polymeric sol having different particle diameter distributions of metal oxide particles is prepared by using a sol-gel method; Preparing a coating composition by mixing 50 to 200 parts by weight of an alcohol having 1 to 4 carbon atoms with respect to 100 parts by weight of the sol solution; Coating the composition on a surface of a heat pipe having grooves formed in a lattice pattern on the surface thereof; It provides a method for superhydrophilic coating of the heat transfer tube consisting of drying the coated heat transfer tube, and then heat treatment.

The coating step and the heat treatment step may be repeated two or more times in order to increase the thermal efficiency according to the improvement of the hydrophilicity.

The drying step is 0.5 to 2 hours at a temperature of 60 ~ 100 ℃, the heat treatment is preferably performed for 1 to 5 hours at a temperature of 150 ~ 250 ℃.

The metal oxide nanosol according to the present invention is used by mixing two kinds of particles having different particle size distributions to maximize the specific surface area during coating and to form a compact coating film by surface roughness produced by particles having different sizes.

In addition, in the case of the nanosol according to the present invention, by including an acid in excess of the stoichiometric amount during manufacture, the cross-linking density is further increased, and the density or hardness of the coating film can be increased even through low temperature heat treatment. have.

On the other hand, addition of a catalyst such as platinum or palladium can maintain hydrophilicity for a long time even without light irradiation.

By coating such a superhydrophilic coating composition on a heat pipe coil, which is exemplarily shown in FIG. 2A, a heat exchanger coil was produced in which the thermal efficiency was significantly improved. This can maximize the energy efficiency to reduce the amount of fuel used, and to reduce the generation of toxic and energy costs. Such superhydrophilic heat pipes can be used as evaporators, absorbers or regenerators in refrigeration or heating devices.

On the other hand, in order to further improve the heat exchange capacity of the heat transfer tube, the grooves of the heat transfer tube were regularly formed to maximize the adsorption of condensed water by maintaining the grooves of the valley and the acid. FIG. 2B is an example showing the groove of the lattice pattern formed in the heat transfer tube surface A of FIG. 2A.

In the case of coating the superhydrophilic coating composition according to the present invention showed a very good hydrophilic properties. 3A and 3B are photographs showing the results of contact angle test of the uncoated copper tube and the coated copper tube according to the present invention, respectively. In the case of Figure 3b it can be seen that as soon as the water droplets fall on the surface of the copper tube spreads almost similar to the surface height has a very good adsorption capacity.

Hereinafter, the features of the present invention and the effects thereof will be described in more detail with reference to Examples.

Example 1.

4.5 g of polymeric TiO ₂ sol having an average particle diameter of 5 nm or less and 1.2 g of TiO ₂ fine powder having an average particle diameter of 10 nm were milled for 24 hours using 0.3 mm diameter zirconia beads. 4 g of TEOS and 1 g of APTMS (propyltrimethoxysilane) were added thereto, followed by stirring at room temperature for 3 hours. Platinum nitrate was added thereto in the range of 0.3 to 3% of the total solids and stirred for 2 hours. 10 g of isopropyl alcohol, 8 g of deionized water, 0.1 g of surfactant, and 0.5 g of sodium acetate as a latent thermosetting catalyst were added thereto, and the mixture was stirred for 1 hour.

The coating composition thus obtained was coated on the surface of the heat transfer tube, dried at 60 ° C. for 30 minutes, and then heat-treated at 180 ° C. for 2 hours.

Example 2.

4.5 g of polymeric TiO ₂ sol having an average particle diameter of 5 nm or less and 1.2 g of TiO ₂ fine powder having an average particle diameter of 10 nm were milled for 24 hours using 0.3 mm diameter zirconia beads. 4 g of TEOS and 1 g of APTMS were added thereto and stirred at room temperature for 3 hours. Palladium nitrate was added thereto in the range of 0.3 to 3% of the total solids and stirred for 2 hours. 10 g of isopropyl alcohol, 8 g of deionized water, 0.1 g of a surfactant, and 0.5 g of sodium acetate as a thermosetting latent catalyst were added and stirred for 1 hour.

The coating composition thus obtained was coated on the surface of the heat transfer tube, dried at 60 ° C. for 30 minutes, and then heat-treated at 180 ° C. for 2 hours.

Example 3.

1.2 g of TiO ₂ fine powder having an average particle diameter of 10 nm was mixed with 4 g of TEOS and 1 g of APTMS and stirred at room temperature for 3 hours. Platinum nitrate was added thereto in the range of 0.3 to 3% of the total solids and stirred for 2 hours. 10 g of isopropyl alcohol, 8 g of deionized water, 0.1 g of surfactant, and 0.5 g of sodium acetate as a latent thermosetting catalyst were added thereto, and the mixture was stirred for 1 hour.

The coating composition thus obtained was coated on the surface of the heat transfer tube, dried at 60 ° C. for 30 minutes, and then heat-treated at 180 ° C. for 2 hours.

Example 4.

4 g of TEOS and 1 g of APTMS were added to 4.5 g of polymeric TiO ₂ sol having an average particle diameter of 5 nm or less, and stirred at room temperature for 3 hours. Platinum nitrate was added thereto in the range of 0.3 to 3% of the total solids and stirred for 2 hours. 10 g of isopropyl alcohol, 8 g of deionized water, 0.1 g of surfactant, and 0.5 g of sodium acetate as a latent thermosetting catalyst were added thereto, and the mixture was stirred for 1 hour.

The coating composition thus obtained was coated on the surface of the heat transfer tube, dried at 60 ° C. for 30 minutes, and then heat-treated at 180 ° C. for 2 hours.

Example 5.

4.5 g of polymeric TiO ₂ sol having an average particle diameter of 5 nm or less and 1.2 g of TiO ₂ fine powder having an average particle diameter of 10 nm were milled for 24 hours using 0.3 mm diameter zirconia beads. 4 g of TEOS was added thereto and stirred at room temperature for 3 hours. Platinum nitrate was added thereto in the range of 0.3 to 3% of the total solids and stirred for 2 hours. 10 g of isopropyl alcohol, 8 g of deionized water, 0.1 g of surfactant, and 0.5 g of sodium acetate as a latent thermosetting catalyst were added thereto, and the mixture was stirred for 1 hour.

The coating composition thus obtained was coated on the surface of the heat transfer tube, dried at 60 ° C. for 30 minutes, and then heat-treated at 180 ° C. for 2 hours.

Example 6.

4.5 g of polymeric TiO ₂ sol having an average particle diameter of 5 nm or less and 1.2 g of TiO ₂ fine powder having an average particle diameter of 10 nm were milled for 24 hours using 0.3 mm diameter zirconia beads. 1 g of APTMS was added thereto and stirred at room temperature for 3 hours. Platinum nitrate was added thereto in the range of 0.3 to 3% of the total solids and stirred for 2 hours. 10 g of isopropyl alcohol, 8 g of deionized water, 0.1 g of surfactant, and 0.5 g of sodium acetate as a latent thermosetting catalyst were added thereto, and the mixture was stirred for 1 hour.

The coating composition thus obtained was coated on the surface of the heat transfer tube, dried at 60 ° C. for 30 minutes, and then heat-treated at 180 ° C. for 2 hours.

Example 7.

4.5 g of polymeric TiO ₂ sol having an average particle diameter of 5 nm or less and 1.2 g of TiO ₂ fine powder having an average particle diameter of 10 nm were milled for 24 hours using 0.3 mm diameter zirconia beads. 4 g of MTMS (Methyltrimethoxysilane) and 1 g of APTMS were added thereto and stirred at room temperature for 3 hours. Platinum nitrate was added thereto in the range of 0.3 to 3% of the total solids and stirred for 2 hours. 10 g of isopropyl alcohol, 8 g of deionized water, 0.1 g of surfactant, and 0.5 g of sodium acetate as a latent thermosetting catalyst were added thereto, and the mixture was stirred for 1 hour.

The coating composition thus obtained was coated on the surface of the heat transfer tube, dried at 60 ° C. for 30 minutes, and then heat-treated at 180 ° C. for 2 hours.

Example 8.

4.5 g of polymeric TiO ₂ sol having an average particle diameter of 5 nm or less and 1.2 g of TiO ₂ fine powder having an average particle diameter of 10 nm were milled for 24 hours using 0.3 mm diameter zirconia beads. 4 g of TEOS and 1 g of APTMS were added thereto and stirred at room temperature for 3 hours. 10 g of isopropyl alcohol, 8 g of deionized water, 0.1 g of surfactant, and 0.5 g of sodium acetate as a latent thermosetting catalyst were added thereto, and the mixture was stirred for 1 hour.

The coating composition thus obtained was coated on the surface of the heat transfer tube, dried at 60 ° C. for 30 minutes, and then heat-treated at 180 ° C. for 2 hours.

After coating the coating composition obtained through the above examples on the heat transfer tube, the contact angle test with water, the adhesion test between the coating film and the heat transfer tube (Scotch tape adhesion test), the hot water resistance test (contact angle measurement after immersion in hot water at 80 ℃ for 24 hours ) Was performed. The test results are shown in the following table.

Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 Example 8 Contact angle (just after heat treatment)  3 °  3 °  5 °  5 °  5 °  3 °  15 °  7 ° After contact angle (90 days after dark)  9 °  10 °  13 °  13 °  23 °  9 °  43 °  24 ° Hot water resistance 3 ° 4 ° 3 ° 5 ° 7 ° 60 ° 45 ° 12 ° Adhesion 100/100 100/100 100/100 100/100 100/100 100/100 100/100 100/100

Examples 1 to 4 were found to be relatively superior in contact angle and hot water resistance.

On the other hand, the coated heat pipe was subjected to a thermal shock test in a total of 1000 cycles by varying the temperature between 0 ℃ and 80 ℃ every 30 minutes. The test showed no deterioration of hydrophilicity, and the surface coating state of the tube remained unchanged.

In addition, the superhydrophilic heat pipe according to the present invention showed an excellent adsorption capacity of almost 100% of the adsorption of condensed water as compared to the uncoated heat pipe (adsorption ratio of 60 to 70%).

As described above, according to the present invention, the superhydrophilic composition is coated on the surface of the heat pipe without high temperature, multi-step complex processing, thereby improving heat exchange capacity of the heat pipe by a simplification process. Even if it is used for a long time in a dark room without heat condition can maintain the heat exchange performance without deterioration of hydrophilicity. Thus, it is possible to provide a heat transfer tube having excellent thermal efficiency and excellent durability.

Claims (14)

Hydrolyzate of organosilane represented by general formula R ¹ _a Si (OR ² ) _4-a , wherein R ¹ and R ² are each independently hydrocarbons having 1 to 6 carbon atoms, and a is an integer of 0 to 3 Or 20 to 75% by weight of the condensate, and A sol solution composed of 25 to 80% by weight of at least one metal oxide selected from TiO ₂ , SiO ₂ , SnO ₂ , ZnO, ZrO ₂ , WO ₃ and V ₂ O ₅ ; Includes; 50 to 200 parts by weight of alcohol having 1 to 4 carbon atoms with respect to 100 parts by weight of the sol solution; The sol solution is characterized by consisting of a particle sol (particulate sol) and polymeric sol (polymeric sol) having a different particle diameter distribution of the metal oxide particles Superhydrophilic Coating Composition. The method of claim 1, wherein the organosilane is methyltrimethoxysilane, methyltriethoxysilane, tetramethoxysilane, tetraethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, phenyltriethoxysilane, phenyltri A superhydrophilic coating composition, which is any one or more materials selected from methoxysilane, diphenyldimethoxysilane, vinyltrimethoxysilane, and vinyltriethoxysilane. The superhydrophilic coating composition of claim 1, wherein the alcohol is at least one material selected from methanol, ethanol, butanol, and isopropyl alcohol. The superhydrophilic coating composition of claim 1, further comprising a silane comprising an amino group. The superhydrophilic coating composition according to claim 4, wherein the silane comprising an amino group is any one selected from aminopropyltrimethoxysilane, aminopropyltriethoxysilane, and aminopropylmethyldimethoxysilane. The superhydrophilic coating composition of claim 1, further comprising 0.1 to 5% of at least one material selected from Pt, Au, Ag, or Pd as a thermosetting catalyst. Superhydrophilic heat transfer tube, characterized in that the composition of claim 1 is coated on the surface. The superhydrophilic heat transfer tube according to claim 7, wherein grooves are formed in a lattice pattern on the surface of the heat transfer tube. 8. The superhydrophilic heat pipe of claim 7, wherein the heat pipe is a copper pipe. 8. The superhydrophilic heat transfer tube according to claim 7, wherein the heat transfer tube is used as an evaporator, absorber, or regenerator of a refrigerating device or a heating device. Hydrolyzate of organosilane represented by general formula R ¹ _a Si (OR ² ) _4-a , wherein R ¹ and R ² are each independently hydrocarbons having 1 to 6 carbon atoms, and a is an integer of 0 to 3 Or 20 to 75% by weight of the partial condensate and 25 to 80% by weight of any one or more metal oxides selected from TiO ₂ , SiO ₂ , SnO ₂ , ZnO, ZrO ₂ , WO ₃ and V ₂ O ₅ . Preparing a sol solution comprising a particle sol and a polymer sol having different particle size distributions by using a sol-gel method; Preparing a coating composition by mixing 50 to 200 parts by weight of an alcohol having 1 to 4 carbon atoms with respect to 100 parts by weight of the sol solution; Coating the composition on a surface of a heat pipe having grooves formed in a lattice pattern on the surface thereof; Drying the coated heat pipe, followed by heat treatment. Super hydrophilic coating method of heat pipe. 12. The method of claim 11, wherein the coating step and the heat treatment step are repeated two or more times. The method of claim 11, wherein the heat treatment is superhydrophilic coating method of the heat transfer tube is carried out for 1 to 5 hours at a temperature of 150 ~ 250 ℃. The method of claim 11, wherein the drying is carried out for 0.5 ~ 2 hours at a temperature of 60 ~ 100 ℃ superhydrophilic coating method of the heat transfer tube.

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