Heat exchange system and application equipment equipped with the same

Abstract

To promote defrosting from a surface of a heat exchanger to obtain excellent heat exchange efficiency for a long period, even when frost adheres to the surface of the heat exchanger, in a heat exchange system comprising a defrosting mechanism.SOLUTION: A heat exchange system comprises: a heat exchanger that is in contact with moisture-containing air and exchanges heat between a refrigerant flowing therein and the air to cool the air; a supply member holding an additive that reduces a contact angle of moisture adhering to the surface of the heat exchanger with respect to the surface of the heat exchanger; and a defrosting mechanism that defrosts frost generated by moisture adhering to the surface of the heat exchanger. During defrosting by the defrosting mechanism, the additive is supplied from the supply member to the surface of the heat exchanger.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a heat exchange system and an application device including the same, and more particularly to a technique for improving the heat exchange efficiency of a heat exchange system including a defrosting mechanism. [Background technology]

[0002] A heat exchange system includes, for example, a heat exchanger that exchanges heat between air and a heat medium. When a heat exchange system is used in a refrigeration system or the like, when the heat exchanger is cooled by heat exchange with a refrigerant, moisture in the air adheres to the surface of the heat exchanger. This moisture adhered to the surface of the heat exchanger forms frost or ice (hereinafter simply referred to as frost).

[0003] When frost forms on the surface of a heat exchanger, the heat exchange efficiency of the heat exchange system decreases due to the effects of the specific heat, thermal conductivity, latent heat, or sensible heat of water. Furthermore, when frost forms on the fins of a heat exchanger, the gaps between the fins are blocked by the frost. This impedes the flow of air within the heat exchanger, reducing its heat exchange efficiency. A similar problem can also occur in air conditioners used in cold regions when ice, snow, or other foreign matter adheres to the heat exchanger of a heat exchange system installed in the outdoor unit.

[0004] If the heat exchange system is equipped with a defrosting mechanism, the frost that has adhered to the surface of the heat exchanger can be removed to some extent by operating the defrosting mechanism. However, if the defrosting by the defrosting mechanism is incomplete, frost will accumulate on the surface of the heat exchanger.

[0005] For example, Patent Document 1 discloses a technology in which a hydrophilic film containing a hydrophilic resin and a silicone resin is formed on the surface of the fins of a heat exchanger, thereby quickly draining moisture adhering to the fins and imparting anti-fouling properties to the fins. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-29248 Summary of the Invention [Problem to be solved by the invention]

[0007] However, in the technology disclosed in Patent Document 1, the hydrophilicity of the hydrophilic film is reduced by the oil repellency of the silicone resin, and sufficient drainage cannot be achieved. Therefore, even in a heat exchange system equipped with a defrosting mechanism, it is difficult for the defrosting mechanism to stably defrost the frost that has adhered to the heat exchanger.

[0008] Therefore, the present disclosure aims to provide a heat exchange system equipped with a defrosting mechanism that promotes defrosting from the surface of a heat exchanger even when frost has formed on the surface of the heat exchanger, thereby enabling excellent heat exchange efficiency to be achieved over a long period of time. [Means for solving the problem]

[0009] A heat exchange system according to one aspect of the present disclosure includes a heat exchanger that comes into contact with air containing moisture and cools the air by exchanging heat between the air and a refrigerant circulating therethrough; a supply member that holds an additive that reduces the contact angle of the moisture adhering to the surface of the heat exchanger with the surface; and a defrosting mechanism that defrosts frost formed by the moisture adhering to the surface, and during defrosting by the defrosting mechanism, the additive is supplied from the supply member to the surface of the heat exchanger.

[0010] According to the above configuration, when the defrosting mechanism is activated in a state in which frost has formed on the heat exchanger surface due to moisture adhering thereto, the additive is supplied from the supply member to the heat exchanger surface during defrosting by the defrosting mechanism. When the moisture produced by melting the frost on the heat exchanger surface comes into contact with the additive, the contact angle of the moisture with respect to the heat exchanger surface decreases, improving the wettability of the heat exchanger surface. As a result, the drainage of moisture and frost from the heat exchanger surface is promoted, improving the defrosting effect. This prevents accumulative accumulation of frost on the heat exchanger surface and shortens the operating time of the defrosting mechanism. Furthermore, for example, by having the defrosting mechanism supply the additive from the supply member to the heat exchanger surface only during defrosting, the amount of additive retained in the supply member can be maintained for a long period of time. As a result, drainage and defrosting from the heat exchanger surface are promoted, and excellent heat exchange efficiency can be achieved for a long period of time.

[0011] Furthermore, the additive may be supplied from the supply member to the surface of the heat exchanger immediately before the defrosting period, which is immediately before the defrosting period starts. This allows the additive to be supplied more sufficiently to moisture adhering to the surface of the heat exchanger.

[0012] The additive may contain a surfactant, which can effectively reduce the contact angle of water adhering to the surface of the heat exchanger. Furthermore, by using an existing surfactant as the additive, the design flexibility of the heat exchange system can be improved.

[0013] In this case, the surfactant may contain a nonionic surfactant. This makes the surfactant less susceptible to the effects of electrolytes in the water, and the defrosting effect of the surfactant can be stably obtained. In this case, the concentration of the surfactant in the mixture of the additive supplied to the surface of the heat exchanger from the supply member and the water adhering to the surface of the heat exchanger may be a value in the range of 1 ppm or more. This allows, for example, a reduction in the amount of surfactant used and the effect of the additive to be obtained over a long period of time.

[0014] Furthermore, the defrosting mechanism may adjust the temperature of the surface to a temperature equal to or higher than the melting point of moisture adhering to the surface when defrosting. In this way, by supplying the additive to the surface of the heat exchanger from the supply member, the defrosting effect of the additive can be obtained quickly.

[0015] The supply member may include a plurality of carriers that carry the additive, and a support that supports the plurality of carriers in a dispersed state so that the additive can be released from the carriers to the outside of the supply member.

[0016] According to the above configuration, by carrying the additive on a plurality of dispersed carriers, it is possible to easily supply the additive from each carrier to a wide range of moisture adhering to the surface of the heat exchanger. Furthermore, by supporting the plurality of carriers with the support so that the additive can be released from the plurality of carriers to the outside of the supply member, it is possible to stably supply the additive from the supply member to the surface of the heat exchanger while supporting the carriers.

[0017] The support may be a porous granular material, which allows a large amount of additive to be held in the pores of the support, and the additive to be gradually released from the supply member onto the surface of the heat exchanger, thereby supplying the additive to the moisture adhering to the surface of the heat exchanger for a long period of time from the initial operation of the heat exchange system.

[0018] The additive may be dissolved, dispersed, or diffused in the moisture adhering to the surface of the heat exchanger, thereby allowing the additive to be rapidly distributed from the supply member to the moisture adhering to the surface of the heat exchanger.

[0019] An applied device according to one aspect of the present disclosure includes any one of the heat exchange systems described above. This applied device may be a refrigeration device that refrigerates or freezes objects and includes a defrosting mechanism that removes frost adhering to the heat exchanger. Furthermore, this applied device may be an air conditioning device that includes an outdoor unit and a defrosting mechanism that removes frost adhering to the heat exchanger, with the heat exchanger, the supply member, and the defrosting mechanism being disposed in the outdoor unit. [Effects of the Invention]

[0020] According to each aspect of the present disclosure, in a heat exchange system equipped with a defrosting mechanism, even if frost adheres to the surface of the heat exchanger, defrosting from the surface of the heat exchanger can be promoted, thereby achieving excellent heat exchange efficiency over a long period of time. [Brief explanation of the drawings]

[0021] [Figure 1] FIG. 1 is a front view of an application device according to a first embodiment. [Figure 2] FIG. 2 is a functional block diagram of the application device of FIG. [Figure 3] FIG. 3 is a schematic diagram showing how the additive is supplied from the supply member of FIG. 1 to the moisture adhering to the surface of the heat exchanger. [Figure 4] FIG. 4 is an enlarged view showing the internal structure of the supply member of FIG. [Figure 5] Figure 5 is a diagram showing the fins of a heat exchanger and their surroundings before and after conventional defrosting. Figure 5(a) shows moisture adhering to the fins. Figure 5(b) shows the moisture adhering to the fins melting and the moisture remaining on the fins. Figure 5(c) shows the frost accumulating on the fins. [Figure 6] Figure 6 is a diagram showing the fins of the heat exchanger and their surroundings before and after defrosting in the first embodiment. Figure 6(a) shows moisture adhering to the fins. Figure 6(b) shows moisture falling (sliding) off the fins. Figure 6(c) shows the defrosted fins. [Figure 7] FIG. 7 is a schematic diagram of an application device according to the second embodiment. [Figure 8] FIG. 8 is a graph showing the relationship between the eluted concentration of the additive and the defrosting time in the test results of Test 1. [Figure 9] FIG. 9 is a graph showing the relationship between the eluted concentration of the additive and the re-cooling time in the test results of Test 1. [Figure 10]FIG. 10 is a graph showing the relationship between the eluted concentration of the additive and the size of the falling droplets in the test results of Test 2. [Figure 11] FIG. 11 is a graph showing the relationship between the eluted concentration of the additive and the size of the falling water droplets in the test results of Test 2. [Figure 12] FIG. 12 is a photograph showing the state of the heat exchanger without the addition of additives in the test results of Test 1. [Figure 13] FIG. 13 is a photograph showing the state of the heat exchanger after the addition of the additive in the test results of Test 1 (when the eluted concentration of the additive was 2 ppm). [Figure 14] FIG. 14 is a photograph showing the state of the heat exchanger after the addition of the additive in the test results of Test 1 (when the eluted concentration of the additive was 6 ppm). [Figure 15] FIG. 15 is a photograph showing the state of the heat exchanger after the addition of the additive in the test results of Test 1 (when the eluted concentration of the additive was 330 ppm). [Figure 16] FIG. 16 is a graph showing the state of moisture adhesion to the test piece (using water containing no surfactant) in the test results of Test 3. [Figure 17] FIG. 17 is a graph showing the state of moisture adhesion to the test piece after adding a surfactant in the test results of Test 3 (using water containing 1 ppm of surfactant). [Figure 18] FIG. 18 is a graph showing the state of moisture adhesion to the test piece after adding a surfactant in the test results of Test 3 (using water containing 2 ppm of surfactant). [Figure 19] FIG. 19 is a graph showing the state of moisture adhesion to the test piece after adding a surfactant in the test results of Test 3 (using water containing 5 ppm of surfactant). DETAILED DESCRIPTION OF THE INVENTION

[0022] Hereinafter, each embodiment will be described with reference to the drawings. (First embodiment) [Applied equipment and heat exchange systems] FIG. 1 is a front view of an application device 1 according to a first embodiment. FIG. 2 is a functional block diagram of the application device 1 of FIG. 1. FIG. 3 is a schematic diagram showing how an additive is supplied from a supply member 6 of FIG. 1 to moisture adhering to the surface of a heat exchanger 3. The application device 1 shown in FIG. 1 is, for example, a refrigeration device that refrigerates or freezes objects. The application device 1 includes a heat exchange system 2 and a housing 7. The housing 7 has a plurality of internal spaces S1 to S4 provided therein. The internal spaces S1 to S4 include, for example, a refrigerator compartment, a freezer compartment, and a vegetable compartment. The heat exchange system 2 includes a heat exchanger (evaporator) 3, a defrosting mechanism 4, and a control unit 5. The heat exchange system 2 also includes a heat exchanger valve 10, a compressor 11, a condenser 12, and a fan 14.

[0023] The heat exchange system 2 exchanges heat between the air in the internal spaces S1 to S4 and a refrigerant to generate cool air. The heat exchanger 3 comes into contact with the moisture-containing air in the internal spaces S1 to S4 and cools the air by exchanging heat between the refrigerant circulating therein and the air. The heat exchanger 3 has a circulation pipe 30 through which the refrigerant flows and a plurality of fins 31 that exchange heat between the refrigerant in the circulation pipe 30 and the air. The plurality of fins 31 extend vertically, for example, and are arranged at intervals in a direction intersecting the vertical direction (here, horizontally). The fins 31 include, for example, a metal material (such as aluminum) with excellent thermal conductivity, but the material of the fins 31 is not limited thereto. The plurality of fins 31 are thermally coupled to the circulation pipe 30. For example, adjacent fins 31 have parallel surfaces.

[0024] The heat exchanger valve 10 is disposed midway through the circulation pipe 30 to adjust the flow rate within the circulation pipe 30. The compressor 11 compresses the liquid refrigerant that has passed through the heat exchanger 3. The condenser 12 cools and liquefies the gaseous refrigerant sent from the compressor 11, and causes the liquefied refrigerant to flow to the heat exchanger 3. The fan 14 circulates the air within the interior spaces S1 to S4 and the air around the heat exchanger 3.

[0025] The defrosting mechanism 4 defrosts by melting frost that has adhered to the surface of the heat exchanger 3. The objects to be defrosted by the defrosting mechanism 4 include frost and ice that adhere to the surface of the heat exchanger 3 as the heat exchange system 2 operates, as well as frost, ice, and snow that have entered the application equipment 1 from the outside into the application equipment 1 when the application equipment 1 is used in a cold climate, for example. Hereinafter, these will be collectively referred to simply as frost.

[0026] The defrosting mechanism 4 is, for example, a heater type and includes a defrost heater 13. During defrosting operation of the applied device 1, the air around the heat exchanger 3 is heated by the defrost heater 13 to become warm air, which then convects. This warm air comes into contact with the surface of the heat exchanger 3, thereby defrosting the heat exchanger 3. When defrosting, the defrosting mechanism 4 of this embodiment adjusts the surface temperature of the heat exchanger 3 to a temperature equal to or higher than the melting point of moisture adhering to the surface of the heat exchanger 3. The type of the defrosting mechanism 4 is not limited to a heater type, and may be any of other known types such as a hot gas type, a water spray type, or an off-cycle type.

[0027] The heat exchange system 2 also has a defrost temperature detection unit 15. The defrost temperature detection unit 15 detects whether or not the piping temperature of the heat exchange system 2 (for example, the temperature of the circulation pipe 30) has reached a predetermined temperature for terminating the defrosting operation of the defrosting mechanism 4. The defrost temperature detection unit 15 includes, for example, a known temperature sensor.

[0028] The control unit 5 individually controls the heat exchanger valve 10, the compressor 11, the defrost heater 13, and the fan 14. For example, the control unit 5 has a timer function, and uses this timer function to automatically activate the defrosting mechanism 4 every time the cooling operation time of the application device 1 reaches a certain time (e.g., 13 hours). The control unit 5 also receives a detection signal from the defrost temperature detection unit 15. For example, the control unit 5 automatically stops the defrosting mechanism 4 based on the detection signal from the defrost temperature detection unit 15. The control unit 5 of this embodiment is realized by a computer including a processor including a CPU and a recording medium including a ROM, a RAM, and the like. The recording medium stores a plurality of control programs, including a heat exchanger control program for the CPU to control the heat exchanger valve 10, the compressor 11, the fan 14, and the like, and a defrost control program for controlling the defrosting mechanism 4 during defrosting operation. If the application device 1 includes a pump for circulating a refrigerant through the circulation pipe 30 of the heat exchanger 3, the control unit 5 may control the pump.

[0029] The heat exchange system 2 includes at least one supply member 6. The supply member 6 holds an additive that reduces the contact angle of water adhering to the surface of the heat exchanger 3 with the surface. The additive facilitates spreading of the water film formed on the surface of the heat exchanger 3, thereby thinning the water film. The supply member 6 disperses the additive in the water and releases the additive to the outside by contacting the water. In this embodiment, as described below, the additive is supplied from the supply member 6 to the surface of the heat exchanger 3 during defrosting by the defrosting mechanism 4. During this supply, the additive is supplied by free fall to the water adhering to the surface of the heat exchanger 3, for example. Here, the defrosting period does not refer to the duration of the defrosting operation, but rather refers to the period from when the frost begins to melt to when the melted water is completely solidified by the re-cooling operation. The additive may be supplied at any timing during the defrosting period. For example, the additive may be supplied at the beginning or near the end of the defrosting period, or throughout the entire defrosting period. In the heat exchange system 2, the additive is gradually released from the moisture adhering to the surface of the heat exchanger 3 every time the defrosting mechanism 4 performs defrosting so that the additive is supplied over a predetermined period (for example, about several years).

[0030] The supply member 6 is, for example, elongated and arranged so as to contact the surface of the heat exchanger 3 (for example, the end face of each fin 31). The supply member 6 of this embodiment is formed in a strip shape and arranged so that its longitudinal direction is along the arrangement direction of the multiple fins 31. The supply member 6 is arranged so as to be detachable in the heat exchange system 2. That is, the supply member 6 can be replaced with respect to the heat exchanger 3 at a predetermined timing. The heat exchange system 2 of this embodiment includes multiple supply members 6 arranged at a distance from each other. One supply member 6 extends in the thickness direction of the multiple fins 31 of the heat exchanger 3 and contacts the end face of each fin 31.

[0031] Here, the applied device 1 is a refrigeration device, and therefore, when the applied device 1 (heat exchange system 2) is operating, the surface of the heat exchanger 3 is cooled to a temperature below freezing through heat exchange with the refrigerant. However, in the applied device 1, the defrosting mechanism 4 is driven during defrosting operation, which warms the air around the supply member 6. The air around the supply member 6 becomes hot and humid. As a result, in the heat exchange system 2, when the defrosting mechanism 4 is defrosting, the additive can be supplied from the supply member 6 to the surface of the heat exchanger 3.

[0032] When the applied device 1 is operating, the supply member 6 may freeze while containing moisture in the air. In such a case, the applied device 1 operates the defrosting mechanism 4 during defrosting operation, causing the air around the supply member 6 to become hot and humid, melting the ice of moisture contained in the supply member 6. Therefore, even if the supply member 6 freezes while the applied device 1 is operating, the additive can be supplied from the supply member 6 to the surface of the heat exchanger 3.

[0033] [Specific examples of supply materials] Fig. 4 is an enlarged view showing the internal structure of the supply member 6 of Fig. 1. As shown in Fig. 4, the supply member 6 contains a plurality of carriers 60 that carry additives, and a support 61 that supports the plurality of carriers 60 in a dispersed state so that the additives can be released from the carriers 60 to the outside of the supply member 6.

[0034] The support 60 of this embodiment is a porous granular material. The outer diameter of this granular material can be set appropriately, for example, to a value of several μm. As an example, this granular material may have a pore volume of several mL / g, a pore diameter of several tens of nm, and a specific surface area of ​​several hundred m. 2 / g. The particle size, specific surface area, and pore size of the granular material are set to values ​​suitable for the sustained release of additives required for the supply member 6, for example. As an example, by forming the support 60 from porous granular material, it is possible to support a large amount of additives inside the support 60. The support 60 of this embodiment contains an inorganic component. As an example, the support 60 is made of porous glass containing glass such as amorphous silica. Examples of materials for the support 60 include at least one of porous glass, activated carbon, zeolite, and porous concrete.

[0035] The support 61 of this embodiment contains a water-insoluble component. As an example, this water-insoluble component is a water-insoluble resin. Examples of the water-insoluble resin include at least one of polyethylene, polypropylene, polyamide, polyethylene terephthalate, polybutylene terephthalate, and acrylic-modified polyethylene (for example, "Acryft" manufactured by Sumitomo Chemical Co., Ltd.).

[0036] In the supply member 6, the gaps between the multiple supports 60 are filled with supports 61. As a result, the multiple supports 60 are supported by the supports 61 while being in contact with or spaced apart from one another. When the supply member 6 comes into contact with moisture, for example, additives are supplied from the supports 60 located on the surface of the supply member 6 and dissolved into the moisture. This reduces the additive concentration in the surface supports 60. Subsequently, the additives move from the supports 60 located inside the supply member 6 to the supports 60 located on the surface of the supply member 6, increasing the additive concentration in the surface supports 60. The additives in the surface supports 60 are again dissolved into the moisture. This process is repeated, and the additive is supplied from the supply member 6 to the external moisture. The additive can be appropriately selected from additives that can reduce the contact angle of moisture adhering to the surface of the heat exchanger 3 with the surface of the heat exchanger 3. As an example, the additive contains a surfactant. Here, the surfactant refers to a compound having a molecular structure containing a hydrophilic group and a hydrophobic group.

[0037] Examples of surfactants include anionic surfactants such as fatty acid salts, N-acylsarcosinates, N-acylglutamates, alkylbenzenesulfonates, malic acid amides, alkanesulfonates, alkyl sulfates, polyoxyethylene alkyl ether sulfates, α-olefin sulfonates, N-acyl-N-methyltaurates, N-sulfofatty acid esters, and alkylphosphates. Examples of cationic surfactants include alkyltrimethylammonium salts, alkylbenzalkonium chloride, fatty acid amidopropyl cations, fatty acid amidobutylguanidine, and dialkyldimethylammonium salts. Examples of amphoteric surfactants include alkyldimethylacetate betaines, fatty acid amidopropyl betaines, alkyldimethylhydroxysulfobetaines, amide amino acid salts, alkylamine oxides, and alkylimidazolinium betaines.

[0038] Examples of nonionic surfactants include oxyalkylene alkyl ether surfactants such as fatty acid glycerin esters, fatty acid sorbitan esters, fatty acid sucrose esters, alkyl polyglucosides, polyoxyethylene propylene alkyl ethers, polyoxyethylene alkyl ethers, polyoxyethylene alkyl phenyl ethers, and polyoxyethylene polyoxypropylene glycols. The surfactants are not limited to these and can be suitably selected depending on the object of use, the environment, and the like.

[0039] The supply member 6 contains, for example, 20% by weight to 50% by weight of the support 61, 10% by weight to 30% by weight of the carrier 60, and a composition formed from the remainder. The additive is contained in this remainder. The composition ratio of the supply member 6 is not limited to this.

[0040] By using a surfactant as an additive, when the additive is supplied to moisture adhering to the surfaces of multiple heat exchangers 3, the contact angle can be effectively reduced, and the additive can be dispersed over a wide area of ​​the surface of each heat exchanger 3. In addition to surfactants, examples of additives include water-soluble organic solvents. Examples of organic solvents include alcohols, ketones, esters, and ethers. Of these, for example, lower alcohols are preferred. Examples of lower alcohols include ethanol, propanol, isopropyl alcohol, and butanol.

[0041] The additive of this embodiment dissolves, disperses, or diffuses in the moisture adhering to the surface of the heat exchanger 3. This allows the additive to be rapidly distributed from the supply member 6 to the moisture adhering to the surface of the heat exchanger 3, even in a direction intersecting the vertical direction. As an example, the additive of this embodiment contains only a surfactant. The surfactant concentration in the mixture of the additive supplied to the surface of the heat exchanger 3 from the supply member 6 and the moisture adhering to the surface of the heat exchanger 3 (hereinafter simply referred to as the surfactant concentration in the mixture) can be appropriately set. As an example, the surfactant concentration in the mixture is preferably 1 ppm or more. As another example, the surfactant concentration in the mixture is preferably greater than 0 ppm and less than or equal to 330 ppm. As will be described later in the confirmation test, a good drainage effect can be achieved even when the surfactant concentration in the mixture is between 1 ppm and 6 ppm.

[0042] Next, an example of a method for manufacturing the supply member 6 will be described. As an example, a support 60, a support 61, and an additive are heated and kneaded to form a strand. This strand is then cut to a predetermined size, and the slices are then injection molded to obtain a supply member 6 of a desired shape. If the supply member 6 is manufactured by injection molding, the shape and size of the supply member 6 can be easily set to match, for example, the internal space of the heat exchange system 2, such as the shape of the heat exchanger 3. When manufacturing the supply member 6 by heating and kneading materials and then injection molding them, the material for the support 60 is preferably one that has strength sufficient to withstand the kneading and heat resistance in the temperature range used during injection molding. The material for the support 61 and the additive is preferably one that has heat resistance in the temperature range used during injection molding.

[0043] The shape of the supply member 6 is not limited to an elongated shape, and may be, for example, a spherical shape such as an oval sphere, a rectangular parallelepiped, etc. For example, by arranging a cylindrical supply member 6 at the top of the heat exchanger 3 so that its longitudinal direction is aligned with the arrangement direction of the multiple fins 31, the additive can be efficiently diffused over a wide area of ​​the surface of each heat exchanger 3.

[0044] The supply member 6 may contain other components. Examples of such components include, but are not limited to, at least one of surfactants other than the additives, esters, salts, antifoaming agents, viscosity modifiers, fragrances, colorants, pH adjusters, antioxidants, and inorganic substances such as talc and silica. The number of supply members 6 included in the heat exchange system 2 is not limited.

[0045] [Heat exchange systems and application equipment] During cooling operation of the application equipment 1, the gaseous refrigerant discharged from the heat exchanger 3 is compressed by the compressor 11 to a high-temperature, high-pressure state, and then sent to the condenser 12. The gaseous refrigerant is cooled by the condenser 12 to become a liquid refrigerant. This liquid refrigerant flows through a capillary tube separately provided in the application equipment 1, becoming a low-temperature, low-pressure state, and then is supplied to the heat exchanger 3.

[0046] Additionally, by driving the fan 14, air from the internal spaces S1 to S4 is supplied to the periphery of the heat exchanger 3 and comes into contact with the fins 31. As a result, the air around the heat exchanger 3 exchanges heat with the refrigerant circulating inside the heat exchanger 3 via the fins 31, becoming cold air. By driving the fan 14, the cold air is supplied to the internal spaces S1 to S4 and used to cool objects. The refrigerant used for heat exchange flows through the circulation pipe 30 and is then sent back to the compressor 11.

[0047] The air in the interior spaces S1 to S4 contains moisture. When the air comes into contact with the surface of the heat exchanger 3, which has been cooled by heat exchange with the refrigerant, moisture adheres to the surface. This moisture condenses into droplets. The droplets are cooled by the heat exchanger 3 and freeze. The frozen droplets accumulate and adhere to the surface of the heat exchanger 3, causing frost to form on the surface of the heat exchanger 3.

[0048] Conventionally, when frost forms on the surface of the heat exchanger 3, the heat exchange efficiency of the heat exchanger decreases due to the influence of the specific heat, thermal conductivity, latent heat, or sensible heat of water. Furthermore, when the gaps between the fins 31 are blocked by frost, the flow of air inside the heat exchanger is hindered, thereby decreasing the heat exchange efficiency.

[0049] When the control unit 5 determines that the cooling operation time of the application device 1 has reached a predetermined time, the control unit 5 controls the defrosting mechanism 4 to start a defrosting operation. As an example, the defrosting mechanism 4 heats the air around the heat exchanger 3 using the defrost heater 13 and causes the heated air to circulate inside the housing 7. As a result, the frost on the surface of the heat exchanger 3 comes into contact with the heated air and melts. In addition, the air around the supply member 6 becomes hot and humid. As a result, the additive is supplied from the supply member 6 to the surface of the heat exchanger 3.

[0050] The additive supplied from the supply member 6 reduces the contact angle of water with the surface of the heat exchanger 3, improving the wettability (hydrophilicity) of the surface. This reduces the thickness of the water film formed on the surface of the heat exchanger 3. Furthermore, the surface tension of the water is reduced (in other words, the surface energy of the water is reduced). Therefore, even if the water droplets are quite small, they easily roll off the surface of the fins 31. Furthermore, the water droplets easily fall from the vertical lower ends of the fins 31. This promotes drainage from the surface of the heat exchanger 3. As a result, a decrease in the heat exchange efficiency of the heat exchange system 2 due to frost formation on the surface of the heat exchanger 3 or frost obstructing the flow of air near the surface of the heat exchanger 3 is prevented. Furthermore, since a thin water film is formed on the surface of the heat exchanger 3, even if impurities in the air adhere to the surface of the heat exchanger 3, the impurities are quickly discharged along with the water film, thereby maintaining the surface of the heat exchanger 3 in a clean state.

[0051] As the defrosting operation by the defrosting mechanism 4 continues, when the control unit 5 determines from the detection signal of the defrost temperature detection unit 15 that the piping temperature of the heat exchange system 2 has reached a predetermined temperature, the control unit 5 stops the defrosting mechanism 4. Thereafter, the control unit 5 controls the heat exchanger valve 10, the compressor 11, the fan 14, etc. to start a re-cooling operation.

[0052] (Details on the effects of additives) FIG. 5 is a diagram that schematically shows the state of the surface of a heat exchanger (here, fins as an example) and its surroundings before and after conventional defrosting. As shown in FIG. 5, in a conventional refrigeration system, the surface of the heat exchanger is cooled to below freezing and passes through a supercooled state. When the supercooled state is released, the moisture (condensed water) adhering to the fins freezes. This causes frost to form on the fins (FIG. 5(a)). If this frost formation on the fins is repeated, frost will accumulate on the fins. The accumulation of frost reduces the heat exchange efficiency. By operating the defrosting mechanism, the frost adhering to the fins melts and is removed.

[0053] However, it is difficult to completely remove frost using the defrosting mechanism's normal defrosting operation, and some moisture (frost or water droplets) remains on the fins. Water droplets also accumulate at the bottom of the fins (Fig. 5(b)). If moisture remains on the fins in this state and the refrigeration unit performs a re-cooling operation to re-cool the interior of the refrigerator to the set temperature after the defrosting operation, the moisture will refreeze and remain as ice on the surfaces and edges of the fins. Further frost will form on this ice, resulting in a cumulative buildup of frost (Fig. 5(c)). This prevents normal heat exchange in the heat exchanger and reduces the heat exchange rate of the refrigeration unit.

[0054] FIG. 6 is a diagram schematically illustrating the surface (here, fins 31 as an example) of the heat exchanger 3 and its surroundings before and after defrosting in the first embodiment. In contrast, as shown in FIG. 6, in the application device 1, heated air generated by the defrosting operation of the defrosting mechanism 4 comes into contact with frost, melting the frost and generating multiple water droplets ( FIG. 6(a) ). The moisture in the water droplets is modified by the additive supplied by the supply member 6. Adjacent water droplets are easily bonded due to their hydrophilicity and roll (slide) down the surface of the fins 31 due to their own weight. Even minute water droplets easily roll down the surface of the fins 31 because the additive reduces the surface tension of the water. This allows the surface of the fins 31 to be efficiently defrosted ( FIG. 6(b) ). Furthermore, the moisture on the surface of the fins 31 is modified to be hydrophilic by the additive, and spreads widely over the surface of the fins 31. This facilitates heat transfer of the heated air and the heat of the fins 31 heated by the heated air to the moisture spread widely over the surface of the fins 31. As a result, the defrosting effect is further enhanced, and most of the moisture is discharged from the fins 31 (FIG. 6(c)).

[0055] As a result, in the applied device 1, even when defrosting and re-cooling operations are repeatedly performed, cumulative accumulation of frost on the surface of the heat exchanger 3 is prevented. Therefore, an excellent heat exchange rate of the applied device 1 can be obtained over a long period of time. This improves the overall power saving of the applied device 1. Furthermore, by preventing cumulative accumulation of frost on the surface of the heat exchanger 3, the amount of frost to be defrosted in one defrosting operation can be reduced. This shortens the defrosting time. Furthermore, by reducing the amount of heat required for defrosting, the increase in the temperature inside the refrigerator during defrosting operation is relatively suppressed. Therefore, the temperature increase of the objects being refrigerated or frozen inside the refrigerator can also be suppressed. Furthermore, since the frequency of defrosting operations can be reduced, the above-mentioned effects can be further enhanced. Furthermore, by supplying additive from the supply member 6 to the surface of the heat exchanger 3 only during defrosting, the amount of additive retained in the supply member 6 can be maintained for a long period of time.

[0056] As described above, according to the heat exchange system 2 and the applied device 1, when the defrosting mechanism 4 is driven in a state in which frost has formed due to moisture adhering to the surface of the heat exchanger 3, the additive is supplied from the supply member 6 to the surface of the heat exchanger 3 during defrosting by the defrosting mechanism 4. The moisture produced by melting the frost on the surface of the heat exchanger 3 comes into contact with the additive, thereby reducing the contact angle of the moisture with the surface of the heat exchanger 3 and improving the wettability of the surface of the heat exchanger 3. As a result, the drainage of moisture from the surface of the heat exchanger 3 is promoted, improving the defrosting effect. This prevents the accumulation of frost on the surface of the heat exchanger 3 and shortens the operating time of the defrosting mechanism 4. Furthermore, for example, by having the defrosting mechanism 4 supply the additive from the supply member 6 to the surface of the heat exchanger 3 only during defrosting, the amount of additive retained in the supply member 6 can be maintained for a long period of time. As a result, drainage and defrosting from the surface of the heat exchanger 3 are promoted, and excellent heat exchange efficiency can be achieved for a long period of time.

[0057] As an example, the additive of this embodiment contains a surfactant, which can effectively reduce the contact angle of water adhering to the surface of the heat exchanger 3. Furthermore, by using an existing surfactant as the additive, the design freedom of the heat exchange system 2 can be improved.

[0058] As an example, the surfactant contains a nonionic surfactant. This makes the surfactant less susceptible to the effects of electrolytes in the water, allowing the surfactant to provide a stable defrosting effect. The concentration of the surfactant in the mixed solution is 1 ppm or higher. This allows the amount of surfactant used to be reduced, and the effects of the additive can be maintained for a long period of time.

[0059] Furthermore, in this embodiment, when defrosting, the defrosting mechanism 4 adjusts the surface temperature of the heat exchanger 3 to a temperature equal to or higher than the melting point of moisture adhering to the surface of the heat exchanger 3. As a result, by supplying the additive to the surface of the heat exchanger 3 from the supply member 6, the defrosting effect of the additive can be quickly obtained.

[0060] The supply member 6 also includes a plurality of carriers 60 that carry the additive, and a support 61 that supports the plurality of carriers in a dispersed state so that the additive can be released from the carriers to the outside of the supply member 6.

[0061] According to the above configuration, by carrying the additive on the dispersed plurality of supports 60, it becomes easy to supply the additive from each support 60 over a wide range to the moisture adhering to the surface of the heat exchanger 3. Furthermore, by using the support 61 to support the plurality of supports 60 so that the additive can be released from the plurality of supports 60 to the outside of the supply member 6, it is possible to stably supply the additive from the supply member 6 to the surface of the heat exchanger 3 while supporting the supports 60.

[0062] As another example, the support 60 is a porous granular material. This allows a large amount of additive to be held in the pores of the support 60, and the additive is gradually released from the supply member 6 to the surface of the heat exchanger 3, so that the additive can be supplied to the moisture adhering to the surface of the heat exchanger 3 for a long period of time from the initial stage of operation of the heat exchange system 2.

[0063] The additive is, for example, a surfactant, which can effectively reduce the contact angle of water adhering to the surface of the heat exchanger 3. Furthermore, by using an existing surfactant as the additive, the design freedom of the heat exchange system 2 can be improved.

[0064] Furthermore, the additive of this embodiment dissolves, disperses, or diffuses in the moisture adhering to the surface of the heat exchanger 3. This allows the additive to be quickly distributed from the supply member 6 to the moisture adhering to the surface of the heat exchanger 3.

[0065] (Variation) Next, an application device according to a modification of the first embodiment will be described. The application device according to this modification has the same configuration as the application device 1 of the first embodiment, but furthermore, just before defrosting, which is just before the start of defrosting, an additive is supplied from the supply member 6 to the surface of the heat exchanger 3. The just before defrosting mentioned here can be set as appropriate. As an example, the just before defrosting refers to the period from a point several seconds or several minutes before the start of defrosting to the start of defrosting.

[0066] The applied device according to this modification achieves the same effects as the applied device 1. Furthermore, the additive can be supplied more sufficiently to the moisture adhering to the surface of the heat exchanger 3. As a result, drainage and defrosting from the surface of the heat exchanger 3 can be further promoted, and superior heat exchange efficiency can be obtained over a long period of time. When supplying the additive from the supply member 6 to the surface of the heat exchanger 3 immediately before defrosting, a heating device such as a defrost heater 13 may be used to raise the temperature of the air surrounding the supply member 6, making it easier to supply the additive from the supply member 6 to the surface of the heat exchanger 3. The second embodiment will be described below, focusing on the differences from the first embodiment.

[0067] (Second embodiment) FIG. 7 is a schematic diagram of an applied device 101 according to a second embodiment. The applied device 101 according to this embodiment shown in FIG. 7 is an air conditioner and includes a heat exchange system 102. The applied device 101 also includes an indoor unit 120 and an outdoor unit 121. The heat exchange system 102 includes an indoor heat exchanger 103 that exchanges heat between indoor air and a refrigerant, an outdoor heat exchanger 106 that exchanges heat between outdoor air and the refrigerant, a supply member 6 that holds the additive to be added to the outdoor heat exchanger 106, a defrosting mechanism 104 that defrosts the outdoor heat exchanger 106, and a control unit 105. The indoor unit 120 includes the indoor heat exchanger 103. The outdoor unit 121 includes the outdoor heat exchanger 106, the supply member 6, the defrosting mechanism 104, and the control unit 105.

[0068] The heat exchange system 102 also includes a defrost temperature detection unit 115 that detects whether the surface temperature of the outdoor heat exchanger 106 has reached a start temperature at which the defrosting mechanism 104 starts a defrosting operation. The heat exchange system 102 also includes a pressure reducer 107 that reduces the pressure of the refrigerant discharged from the indoor heat exchanger 103, and a compressor 111 that pressurizes the refrigerant discharged from the outdoor heat exchanger. The heat exchangers 103 and 106 are connected by pipes R1 and R2. The refrigerant circulates through the heat exchangers 103 and 106 through the pipes R1 and R2. The control unit 105 controls the defrosting mechanism 104. In the heat exchange system 102, during defrosting by the defrosting mechanism 104, an additive is supplied from the supply member 6 to the surface of the outdoor heat exchanger 106. Here, the defrosting mechanism 104 is, for example, composed of the compressor 111 and the pipes R1 and R2. The control unit 105 temporarily operates the application device 101 in cooling mode to warm the heat exchanger 106 .

[0069] As an example, the applied device 101 is a heating device that heats a room. During heating operation of the applied device 101, for example, in the indoor heat exchanger 103, heat is exchanged between a high-temperature, high-pressure gaseous refrigerant circulating inside the indoor heat exchanger 103 and low-temperature indoor air. This warms the indoor air. The refrigerant is discharged from the indoor heat exchanger 103 in a liquid state and sent to the outdoor unit through piping R2. In the outdoor unit, the refrigerant is decompressed by a pressure reducer 107 and sent to the outdoor heat exchanger 106. In the indoor heat exchanger, the refrigerant exchanges heat with the outdoor air and becomes gaseous. This heat exchange lowers the surface temperature of the outdoor cooler. The gaseous refrigerant discharged from the outdoor heat exchanger is compressed by a compressor 111 to a high-temperature, high-pressure state and sent to the indoor unit 120 through piping R1. The refrigerant is then used again to heat the room.

[0070] Here, when the surface of the outdoor heat exchanger 106 cooled by the refrigerant comes into contact with the outside air containing moisture, moisture adheres to the surface of the outdoor heat exchanger 106. During heating operation of the applied device 101, the outdoor heat exchanger 106 is cooled by heat exchange between the outside air and the refrigerant. As a result, the moisture adhered to the surface of the heat exchanger 106 freezes. As this frozen moisture accumulates, frost forms on the surface of the heat exchanger 106.

[0071] Furthermore, when the application device 1 is used in a cold region, the outside air may contain ice and snow. In this case, this ice and snow may adhere to the surface of the outdoor heat exchanger 106. In the application device 1, the adhesion of ice and snow also causes frost to form on the surface of the heat exchanger 106.

[0072] During heating operation of the applied device 101 of this embodiment, if the amount of frost on the surface of the heat exchanger 106 increases and the control unit 105 determines, based on a detection signal from the defrost temperature detection unit 115, that the temperature detected by the defrost temperature detection unit 115 exceeds a threshold, the control unit 105 controls the defrosting mechanism 104 to start a defrosting operation, similar to the control unit 5. The defrosting mechanism 104 warms the heat exchanger 106 by temporarily operating the applied device 101 in cooling mode. This melts the frost that has adhered to the heat exchanger 106. Furthermore, the frost that has adhered to the supply member 6 melts. As a result, the additive is supplied from the supply member 6 to the surface of the heat exchanger 106.

[0073] Therefore, the heat exchange system 102 and the applied equipment 101 also achieve the same effects as the heat exchange system 2 and the applied equipment 1. Specifically, when the defrosting mechanism 104 is driven in a state in which frost has formed due to moisture adhering to the surface of the outdoor heat exchanger 106, the additive is supplied from the supply member 6 to the surface of the outdoor heat exchanger 106 during defrosting by the defrosting mechanism 104. This reduces the contact angle of the moisture generated by melting the frost on the surface of the outdoor heat exchanger 106 with the surface of the outdoor heat exchanger 106, improving the wettability of the surface of the outdoor heat exchanger 106. As a result, the discharge of moisture from the surface of the outdoor heat exchanger 106 is promoted, improving the defrosting effect. This prevents the accumulation of frost on the surface of the outdoor heat exchanger 106 and shortens the operating time of the defrosting mechanism 104. Furthermore, since the defrosting mechanism 104 supplies the additive from the supply member 6 to the surface of the outdoor heat exchanger 106 only during defrosting, the amount of additive retained in the supply member 6 can be maintained for a long period of time. As a result, in the heat exchange system 102 and the applied equipment 101, drainage and defrosting from the surface of the outdoor heat exchanger 106 can be promoted, and excellent heat exchange efficiency can be obtained for a long period of time.

[0074] The applied device 101 driven as a heating device is not limited to a type that uses a refrigerant. The applied device 101 may be, for example, a heat pump water heater, a heat pump hot water heating device, a hot water heating device that supplies hot water, or a heat pump heating device dedicated to electric vehicles (EVs).

[0075] (Confirmation test) Next, confirmation tests and their results for the present disclosure are described below, but the present disclosure is not limited to the configurations of the following examples. The additive stock solution used in this experiment contains only a surfactant. Furthermore, the "eluted concentration of additive" described below refers to the concentration of surfactant in the mixed solution. In other words, the "eluted concentration of additive" refers to the diluted concentration of surfactant when the additive supplied to the surface of the heat exchanger 3 from the supply member 6 is used as the stock solution and this stock solution is diluted with moisture adhering to the surface of the heat exchanger 3.

[0076] [Test 1] Applied equipment 1, which is a refrigeration device according to the first embodiment, was prepared as Examples 1 and 2. In each of Examples 1 and 2, six supply members 6, each with its longitudinal direction extending horizontally, were arranged relative to the heat exchanger 3. The configuration of the supply members 6 was set as follows. Examples 1 and 2 had the same configuration and experimental conditions. Shape: Cylinder with a diameter of 8 mm and a length of 14.7 mm Weight: approx. 7g / piece

[0077] Additionally, an applied appliance similar to those in Examples 1 and 2, except that it did not include the supply member 6, was prepared as Comparative Example 1. A Panasonic refrigerator "NR-F606WPX" was used as the base configuration for each of the applied appliances in Examples 1 and 2 and Comparative Example. Each of the applied appliances in Examples 1 and 2 and Comparative Example 1 was placed in a test room with an air-conditioned temperature set to 25°C and no humidity control (approximately 20-60% relative humidity). A total of five trays containing 200 g of water-soaked paper rags ("Kimtowel" manufactured by Nippon Paper Classia Co., Ltd.) were placed in the interior spaces S1-S4. The air in the interior spaces S1-S4 and around the heat exchanger was set to contain moisture, and a moisture load was applied to each applied appliance. In Examples 1 and 2, a nonionic surfactant was used as the surfactant, and the elution concentration of the additive was varied within a range of 0 ppm to 400 ppm. Each application device was set to start defrosting operation every time the cooling operation time reached 13 hours, to end defrosting operation when the pipe temperature of the heat exchange system reached 10°C during defrosting operation, and to start re-cooling operation after the defrosting operation.

[0078] Furthermore, the surfactant used in this experiment is an organic substance. Therefore, the elution concentration of the additive was calculated using the following method. First, drain water containing the additive and water resulting from melting frost generated during defrosting operation was collected, and the total organic carbon (TOC) in the drain water was measured. This TOC measurement value (ppm) was converted to concentration (ppm) using the calibration curve of the surfactant used in this experiment. In this calculation method, if the chemical structure (molecular weight and number of carbon atoms) of the surfactant used is similar to that of a known surfactant, the calibration curve of the known surfactant can be used as an approximation. The measurement results are shown in Figure 8.

[0079] FIG. 8 is a graph showing the relationship between the eluted concentration of additive and the defrosting time in the test results of Test 1. The eluted concentration of additive and the defrosting time in FIG. 8 each represent the average value when the applied equipment was subjected to three defrosting operations. As shown in FIG. 8, the defrosting time in Comparative Example 1 was approximately 35 minutes, whereas the defrosting times in Examples 1 and 2 were confirmed to be shorter by 10 minutes or more than that of Comparative Example 1. Furthermore, in Examples 1 and 2, it was confirmed that even when the eluted concentration of additive was an extremely low concentration of 2 ppm, the defrosting time was clearly shorter than that of Comparative Example 1. Furthermore, in Examples 1 and 2, it was confirmed that when the eluted concentration of additive increased to approximately 10 ppm, the defrosting time was shortened to nearly 10 minutes than that of Comparative Example 1.

[0080] 9 is a graph showing the relationship between the eluted concentration of additive and the re-cooling time in the test results of Test 2. As shown in FIG. 9, the re-cooling time in Comparative Example 1 was approximately 68 minutes, whereas in Examples 1 and 2, it was confirmed that the re-cooling time was shortened to 20 minutes or more compared to Comparative Example 1. Furthermore, similar to the defrosting time shown in FIG. 8, it was confirmed that the re-cooling times in Examples 1 and 2 were clearly shorter than in Comparative Example 1 even when the eluted concentration of additive was an extremely low concentration of 2 ppm. Furthermore, in Examples 1 and 2, it was confirmed that the re-cooling time was shortened to nearly 20 minutes compared to Comparative Example 1 when the eluted concentration of additive was increased to approximately 10 ppm.

[0081] [Test 2] Next, we investigated the relationship between the additive elution concentration when an additive was attached to a heat exchanger fin and the size of the water droplets that could roll off the surface when attached to a fin with its surface aligned parallel to the vertical direction. In this test, a smooth aluminum metal plate specimen was used as the fin. The test results are shown in Figure 10. Figure 10 is a graph showing the relationship between the additive elution concentration and the size of the rolling droplets in Test 2. As shown in Figure 10, when the additive elution concentration was 0 ppm, the size of the rolling droplets was approximately 36.4 μl. However, when the additive elution concentration reached a few ppm, the size of the rolling droplets rapidly decreased to approximately 12 μl. It was then confirmed that the size of the rolling droplets decreased to approximately 5.0 μl up to a concentration of 1000 ppm.

[0082] We also investigated the relationship between the additive elution concentration when an additive was attached to a heat exchanger fin and the size of the water droplets that could fall from the bottom or end of the fin when the surface of the fin was aligned parallel to the vertical direction. In this test, we also used aluminum metal plate specimens with smooth surfaces as fins. The results are shown in Figure 11. Figure 11 is a graph showing the relationship between the additive elution concentration and the size of the falling water droplets in Test 2. As shown in Figure 11, when the additive elution concentration was 0 ppm, the size of the falling water droplets was approximately 11.3 μl. However, when the additive elution concentration reached a few ppm, the size of the falling water droplets rapidly decreased. It was then confirmed that the size of the falling water droplets decreased to approximately 5.2 μl up to a concentration of 1000 ppm.

[0083] The reason for the results shown in Figures 10 and 11 is believed to be that the surface tension of the water on the fin surface is reduced by modifying it with the surfactant, making it easier for droplets to roll off and fall. Furthermore, in applied equipment, the hydrophilic effect of the water reduces the distance between droplets on the fin surface. This is believed to be because multiple droplets easily combine and grow, further improving drainage. This not only contributes to improving the defrosting effect, but also contributes to shortening the re-cooling operation time after a defrosting operation in applied equipment, for example.

[0084] Furthermore, even if the additive or the moisture containing the additive remaining on the surface of the fin freezes, a good defrosting effect can be achieved as long as the eluted concentration of the additive is at least several ppm. This is thought to be because the moisture on the surface of the fin is modified by the surfactant, causing the moisture to spread widely over the surface of the fin, facilitating heat transfer from the heated air used during defrosting and the fins heated by the heated air to the moisture on the surface of the fin. This contributes to a shorter defrosting time.

[0085] [About the heat exchanger before defrosting] Here, Fig. 12 is a photograph showing the state of the heat exchanger without the addition of additive in the test results of Test 1. Fig. 13 is a photograph showing the state of the heat exchanger after the addition of additive (when the elution concentration of additive is 2 ppm) in the test results of Test 1. Fig. 14 is a photograph showing the state of the heat exchanger after the addition of additive (when the elution concentration of additive is 6 ppm) in the test results of Test 1. Fig. 15 is a photograph showing the state of the heat exchanger after the addition of additive (when the elution concentration of additive is 330 ppm) in the test results of Test 1. Figs. 12 to 15 show the state of the heat exchanger immediately before the 15th defrosting operation after the application equipment started operating.

[0086] In the comparative example shown in Figure 12, a considerable amount of droplet-like frost remained on the fin surface, and it was found that the frost accumulated cumulatively. It was also confirmed that large clumps of frost formed locally on the underside of the fin in the comparative example. In contrast, no frost or clumps of frost were observed in the examples shown in Figures 13 to 15, as in the comparative example. It was also confirmed that as the surfactant concentration increased, the amount of tiny droplets of ice adhering to the fin surface decreased.

[0087] The reason why the defrosting effect of the Example is so high is thought to be that the moisture adhering to the fins 31 is modified by the additive supplied by the supply member 6. That is, in the Example, the moisture adhering to the fins 31 is modified by contact with the additive, and the moisture falls from the fins 31, accelerating drainage (liquid drainage). In contrast, in the Comparative Example, the moisture is not modified by the additive, and therefore it is thought that moisture was relatively likely to adhere to the surface of the fins both before and after defrosting.

[0088] [Test 3] Next, we investigated the moisture adhesion state on the fin surface when water containing no surfactant was applied to the fin of a heat exchanger and when water containing surfactant was applied to the fin of a heat exchanger. In this test, aluminum metal plate test pieces with smooth surfaces were used as fins. Figure 16 is a graph showing the moisture adhesion state on the test piece (using water containing no surfactant) in the test results of Test 3. Figure 17 is a graph showing the moisture adhesion state on the test piece (using water containing 1 ppm surfactant) after the surfactant was added in the test results of Test 3. Figure 18 is a graph showing the moisture adhesion state on the test piece (using water containing 2 ppm surfactant) after the surfactant was added in the test results of Test 4. Figure 19 is a graph showing the moisture adhesion state on the test piece (using water containing 5 ppm surfactant) after the surfactant was added in the test results of Test 4. The arrows in Figures 17 to 19 indicate the top positions of the water films attached to the test pieces.

[0089] In the comparative example shown in Figure 16, large droplets of water adhered to the surface of the test piece, and it was found that the water did not easily spread over the surface of the fin. In contrast, in the examples shown in Figures 13 to 15, large droplets of water like those in the comparative example were not observed. It was also confirmed that as the surfactant concentration increased, a thin water film spread more easily over the surface of the test piece.

[0090] The reason why a thin water film easily spreads on the surface of the test specimen in the examples is thought to be that the additive supplied by the supply member modifies the moisture adhering to the test specimen, improving its hydrophilic effect. That is, in the examples, the moisture adhering to the test specimen is modified by contact with the additive, reducing the contact angle with the surface of the test specimen. This makes it easier for heat to be transferred from the heated air used during defrosting, or from the test specimen heated by the heated air, to the moisture on the surface of the fin, making it easier to shorten the defrosting time. In contrast, in the comparative examples, the moisture was not modified by the additive, so the contact angle with the surface of the test specimen was large, making it easier for large droplets of moisture to adhere.

[0091] The present disclosure is not limited to the above-described embodiments, and the configuration and method thereof may be changed, added, or deleted without departing from the spirit of the present disclosure. The additive supplied by the supply member 6 may contain multiple components. When the additive contains multiple components, the additive may include, for example, a first component that has the function of reducing the contact angle of water with the heat exchanger surface and a second component that activates the function of the first component to reduce the contact angle.

[0092] Furthermore, the supplying member 6 may be arranged so as to be able to supply the additive to the moisture adhering to the surface of the heat exchanger. Therefore, for example, the supplying member 6 may be arranged apart from the surface of the heat exchanger. In this case, the additive from the supplying member 6 may be dripped onto the moisture adhering to the surface of the heat exchanger, or the additive may be supplied via a member separate from the supplying member 6.

[0093] The applied devices 1, 101 are not limited to being configured to automatically start the defrosting operation, and may be configured to start the defrosting operation in response to, for example, a user instruction. In this case, when a user inputs a defrosting operation instruction into an input unit of the applied device 1, the control unit 5 may control the defrosting mechanism 4 to start the defrosting operation. The heat exchange system 102 may further include, in the indoor unit 120, a supply member 6 that holds an additive that reduces the contact angle of moisture adhering to the surface of the indoor heat exchanger 103 with respect to the surface. [Explanation of symbols]

[0094] 1, 101 Application equipment 2, 102 Heat exchange system 3, heat exchanger 4, 104 Defrosting mechanism 6 Supply materials 60 Support 61 Support 103 Indoor heat exchanger (heat exchanger) 106 Outdoor heat exchanger (heat exchanger) 121 Outdoor unit

Claims

1. a heat exchanger that comes into contact with moisture-containing air and cools the air by exchanging heat between the air and a refrigerant flowing therethrough; a supply member for holding an additive that reduces the contact angle of the water adhering to the surface of the heat exchanger with the surface; a defrosting mechanism that removes frost generated by the moisture adhering to the surface, the supply member includes a plurality of carriers that carry the additive, and a support that supports the plurality of carriers in a dispersed state so as to allow the additive to be released from the carriers to the outside of the supply member, The heat exchange system, wherein the additive is supplied from the supply member to the surface of the heat exchanger during defrosting by the defrosting mechanism.

2. The heat exchange system according to claim 1 , further comprising: a supply member that supplies the additive to the surface of the heat exchanger immediately before defrosting, the supply member being configured to supply the additive to the surface of the heat exchanger immediately before the defrosting period is started.

3. The heat exchange system according to claim 1 or 2, wherein the additive contains a surfactant.

4. The heat exchange system according to claim 3 , wherein the surfactant contains a nonionic surfactant.

5. 5. The heat exchange system according to claim 3, wherein a concentration of the surfactant in a mixture of the additive supplied from the supply member to the surface of the heat exchanger and the moisture adhering to the surface of the heat exchanger is in a range of 1 ppm or more.

6. The heat exchange system according to any one of claims 1 to 5, wherein the defrosting mechanism adjusts the temperature of the surface to a temperature equal to or higher than a melting point of moisture adhering to the surface when performing the defrosting.

7. A heat exchange system as described in claim 1, wherein the additive is supplied from the supply member to the surface of the heat exchanger only during defrosting.

8. 8. The heat exchange system according to claim 1, wherein the support is a porous granular material.

9. The heat exchange system according to any one of claims 1 to 8, wherein the additive dissolves, disperses, or diffuses in moisture adhering to the surface of the heat exchanger.

10. An application device comprising the heat exchange system according to any one of claims 1 to 9.

11. The application equipment according to claim 10, which is a refrigeration device for refrigerating or freezing an object.

12. An air conditioning device equipped with an outdoor unit, The application equipment according to claim 10 , wherein the heat exchanger, the supply member, and the defrosting mechanism are disposed in the outdoor unit.

Images