JP2023137748A - Heat exchange unit and dehumidifier - Google Patents

Abstract

To provide a heat exchange unit capable of suppressing corrosion in a condenser having an aluminum pipe due to the influence of dew condensation water generated in an evaporator having a copper pipe.SOLUTION: A heat exchange unit includes: an evaporator 121 arranged in an air passage formed inside a housing; a first condenser 122 arranged on the downstream side of the evaporator 121 in the air passage; and a second condenser 123 arranged on the downstream side of the first condenser 122 in the air passage. Each of the evaporator 121, the first condenser 122 and the second condenser 123 includes a heat transfer pipe 130 in which a refrigerant circulates inside. The heat transfer pipe 130 includes a plurality of linear parts 132 and a U-shaped part 131 for connecting the linear parts 132 with each other. The heat transfer pipe 130 of the evaporator 121 is a copper pipe. The heat transfer pipe of the first condenser 122 is a copper pipe or an aluminum pipe. The heat transfer pipe of the second condenser 123 is an aluminum pipe. In the heat transfer pipe 130 which is the copper pipe, a hydrophilic layer 200 is formed on an outside surface of the U-shaped part 131.SELECTED DRAWING: Figure 4

Description

The present disclosure relates to heat exchange units and dehumidifiers.

An evaporator is known that includes a refrigerant pipe through which a refrigerant flows and exchanges heat with surrounding air, and the outer peripheral surface of the refrigerant pipe has a hydrophobic surface (for example, see Patent Document 1).

Special Publication No. 2014-524984

However, when the technology shown in Patent Document 1 is applied to a heat exchange unit in which a plurality of heat exchangers are arranged in the direction of air flow in the air passage, the condensed water adhering to the surface of the evaporator flows into the air passage. Easily blown away by air currents inside. The condensed water adhering to the surface of the evaporator contains metal ions of the metals that make up the evaporator. When a heat exchange unit includes a heat exchanger made of a metal material different from that of the evaporator, if condensed water adhering to the surface of the evaporator scatters and adheres to other heat exchangers, the refrigerant pipes of other heat exchangers may There is a concern that catalytic corrosion of dissimilar metals may occur and refrigerant leakage may occur. Specifically, if there is an evaporator with copper heat transfer tubes on the upstream side and a condenser with aluminum heat transfer tubes on the downstream side, if condensed water containing copper ions adheres to the condenser, the aluminum tubes of the condenser will is corroded.

The present disclosure has been made to solve such problems. The purpose is to provide a heat exchange unit and a dehumidifier that can suppress corrosion in a condenser having a heat transfer tube made of aluminum due to the influence of condensed water generated in an evaporator having heat transfer tubes made of copper.

The heat exchange unit according to the present disclosure includes: an evaporator disposed in an air passage formed inside a housing; a first condenser disposed downstream of the evaporator in the air passage; a second condenser disposed downstream of the first condenser in the air path, each of the evaporator, the first condenser, and the second condenser having a refrigerant flowing therein. a heat exchanger tube, the heat exchanger tube includes a plurality of straight parts and a U-shaped part connecting the straight parts, the heat exchanger tube of the evaporator is a copper tube, and the first The heat exchanger tube of the condenser is a copper tube or an aluminum tube, the heat exchanger tube of the second condenser is an aluminum tube, and the heat exchanger tube that is a copper tube has an outer surface of the U-shaped portion. A hydrophilic layer is formed.

Further, a dehumidifier according to the present disclosure includes a heat exchange unit configured as described above.

According to the heat exchange unit and dehumidifier according to the present disclosure, corrosion in a condenser having a heat transfer tube made of aluminum can be suppressed due to the influence of condensed water generated in an evaporator having a heat transfer tube made of copper. .

1 is a diagram schematically showing the overall configuration of a dehumidifier including a heat exchange unit according to Embodiment 1 of the present invention. FIG. 2 is a front view of a heat exchanger included in the heat exchange unit according to Embodiment 1 of the present invention. It is a figure which shows typically the modification of the heat exchange unit based on Embodiment 1 of this invention. It is a figure explaining the state of the dew condensation water adhering to the heat exchanger tube U-shaped part of the heat exchange unit based on Embodiment 1 of this invention, together with a comparative example and a modification. It is a figure which shows typically the modification of the dehumidifier provided with the heat exchange unit based on Embodiment 1 of this invention. It is a figure which shows typically the modification of the dehumidifier provided with the heat exchange unit based on Embodiment 1 of this invention. It is a figure which shows typically the modification of the dehumidifier provided with the heat exchange unit based on Embodiment 1 of this invention.

Embodiments of a heat exchange unit and a dehumidifier according to the present disclosure will be described with reference to the accompanying drawings. In each figure, the same or corresponding parts are given the same reference numerals, and overlapping explanations will be simplified or omitted as appropriate. In the following description, for convenience, the positional relationship of each structure may be expressed based on the illustrated state. Note that the present disclosure is not limited to the following embodiments, and any combination of embodiments, modification of any component of each embodiment, or modification of each embodiment may be made without departing from the spirit of the present disclosure. Any component of the embodiment can be omitted.

Embodiment 1.
Embodiment 1 of the present disclosure will be described with reference to FIGS. 1 to 7. FIG. 1 is a diagram schematically showing the overall configuration of a dehumidifier including a heat exchange unit. FIG. 2 is a front view of a heat exchanger included in the heat exchange unit. FIG. 3 is a diagram schematically showing a modification of the heat exchange unit. FIG. 4 is a diagram illustrating the state of condensed water adhering to the U-shaped portion of the heat exchanger tube of the heat exchange unit, together with a comparative example and a modified example. 5 to 7 are diagrams schematically showing modified examples of a dehumidifier equipped with a heat exchange unit.

What is shown in FIG. 1 is a dehumidifier 100 that is an example of a device equipped with a heat exchange unit according to this embodiment. As shown in the figure, a dehumidifier 100 equipped with a heat exchange unit according to this embodiment includes a housing 110. The housing 110 is formed to be self-supporting. The housing 110 is formed with an inlet and an outlet. The suction port is an opening for sucking air into the housing 110 from outside. The suction port is arranged on the back side of the housing 110. The air outlet is an opening for blowing air from the inside of the housing 110 to the outside. The air outlet is arranged at the top of the housing 110.

An air path leading from the suction port to the air outlet is formed inside the housing 110. Inside the housing 110, a blower fan 112 and a heat exchange unit are provided. The blower fan 112 is arranged in an air path inside the housing 110. The blower fan 112 is used to generate an air flow that is sucked in from an inlet, passes through an air path, and is blown out from an outlet.

A heat exchange unit is arranged between the blower fan 112 and the suction port in the air path inside the housing 110. The heat exchange unit includes an evaporator 121, a first condenser 122, and a second condenser. A second condenser 123 is disposed upstream of the blower fan 112 in the air path inside the housing 110 . The first condenser 122 is arranged upstream of the second condenser 123 in the air path inside the housing 110 . An evaporator 121 is arranged upstream of the first condenser 122 in the air path inside the housing 110. That is, in the air path, the evaporator 121, the first condenser 122, and the second condenser 123 are arranged adjacent to each other in this order from the upstream side. In this way, the air path where the air sucked in from the suction port passes through the evaporator 121, the first condenser 122, the second condenser 123, and the blower fan 112 in this order and blows out from the air outlet is formed in the housing. 110.

Inside the housing 110, a compressor 111, a drain pan 150, and a water storage tank 160 are further provided. The compressor 111 is for circulating refrigerant through the heat exchange units, ie, the evaporator 121, the first condenser 122, and the second condenser 123. Drain pan 150 is provided at least below evaporator 121. In the illustrated configuration example, the drain pan 150 is arranged below the evaporator 121, the first condenser 122, and the second condenser 123. As will be described later, the air passing through the evaporator 121 is cooled. At this time, condensation water may occur. Drain pan 150 is for receiving condensed water generated in evaporator 121.

The water storage tank 160 is a water storage section that stores dew water generated in the evaporator 121. A drain port 151 is formed in the drain pan 150. The water storage tank 160 is arranged below the drain port 151 of the drain pan 150. The condensed water generated in the evaporator 121 falls and is received by the drain pan 150. The condensed water that has fallen onto the drain pan 150 passes through the drain port 151 and is collected in the water storage tank.

When the dehumidifier 100 configured as described above starts operating, the compressor 111 and the blower fan 112 operate. When the compressor 111 operates, it circulates refrigerant through the heat exchange units, namely the evaporator 121, the first condenser 122, and the second condenser 123. When the blower fan 112 operates, an air flow from the suction port to the blowout port is generated in the air path within the housing 110, and air is sucked in from the suction port and air is blown out from the blowout port.

Air sucked in from the suction port first passes through the evaporator 121. As the air passes through the evaporator 121, it is cooled. When the air is cooled to below the dew point temperature in the evaporator 121, condensation occurs. The moisture that becomes condensation water then falls out of the air. The condensed water is received by the drain pan 150 and stored in the water storage tank. The air that has passed through the evaporator 121 then passes through a first condenser 122 and a second condenser 123. When passing through the first condenser 122 and the second condenser 123, the air is heated and returned to room temperature. The room-temperature air from which moisture has been removed and dehumidified passes through the blower fan 112 and is returned indoors from the outlet.

The evaporator 121, the first condenser 122, and the second condenser 123 are heat exchangers that exchange heat between the surrounding air and the refrigerant. In the present disclosure, these evaporator 121, first condenser 122, and second condenser 123 are also collectively referred to as heat exchanger 120. Next, the configurations of the evaporator 121, the first condenser 122, and the second condenser 123, which are the heat exchanger 120, will be explained with reference to FIG. As shown in the figure, each of the evaporator 121, the first condenser 122, and the second condenser 123, which are the heat exchangers 120, includes heat transfer tubes 130 and fins 140. The refrigerant sent out from the compressor 111 flows inside the heat exchanger tube 130 .

The heat exchanger tube 130 includes a straight portion 132 and a U-shaped portion 131. The straight portion 132 has a straight shape. A plurality of straight portions 132 are provided. The plurality of straight portions 132 are arranged parallel to each other and aligned in the vertical direction. Each straight portion 132 is arranged so that its longitudinal direction is horizontal.

The U-shaped portion 131 is bent into a U-shape. The U-shaped portion 131 connects the ends of adjacent straight portions 132. The connecting portion between the straight portion 132 and the U-shaped portion 131 is joined by brazing, for example. That is, the joint portion 133 between the straight portion 132 and the U-shaped portion 131 is a brazed portion.

A plurality of fins 140 are provided. Each fin 140 is a flat metal plate. The plurality of fins 140 are arranged parallel to each other at intervals. Each fin 140 is arranged so that its longitudinal direction is vertical. The straight portion 132 of the heat exchanger tube 130 is provided to pass through the plurality of fins 140.

As shown in FIG. 3, the heat exchange unit of the dehumidifier 100 may further include radiation fins 124. The radiation fins 124 are arranged further upstream of the evaporator 121. The radiation fins 124 are provided in contact with one or both of the fins 140 of the evaporator 121 and the heat transfer tubes 130. By providing such a radiation fin 124, it is possible to improve the cooling efficiency of the air in the evaporator 121, and it is possible to improve the dehumidifying ability.

In the heat exchange unit according to this embodiment, the evaporator 121, which is the heat exchanger 120 disposed most upstream, is made of copper. That is, the heat exchanger tube 130 of the evaporator 121 is a copper tube. The second condenser 123, which is the heat exchanger 120 disposed on the most downstream side, is made of aluminum. That is, the heat exchanger tube 130 of the second condenser 123 is an aluminum tube. Note that aluminum in the present disclosure also includes aluminum alloys. The first condenser 122, which is the intermediate heat exchanger 120, may be made of copper or aluminum. That is, the heat exchanger tube 130 of the second condenser 123 is a copper tube or an aluminum tube. Note that although the heat transfer tube 130 of the evaporator 121 is a copper tube, the fins 140 of the evaporator 121 may be made of aluminum instead of copper, for example.

In the heat exchange unit according to this embodiment, when the heat exchanger tubes 130 of the heat exchanger 120 are copper tubes, as shown in FIG. A hydrophilic layer 200 is formed on the outer surface of the shaped portion 131 . The hydrophilic layer 200 can be formed, for example, by subjecting the outer surface of the U-shaped portion 131 to a well-known hydrophilic coating treatment. As mentioned above, the heat exchanger tube 130 of the evaporator 121 is a copper tube. Therefore, a hydrophilic layer 200 is formed on the outer surface of the U-shaped portion 131 of the evaporator 121. Moreover, the heat exchanger tube 130 of the first condenser 122 may be a copper tube or an aluminum tube. When the heat exchanger tube 130 of the first condenser 122 is a copper tube, the hydrophilic layer 200 is also formed on at least the outer surface of the U-shaped portion 131 of the first condenser 122 . As described above, in the heat exchange unit according to this embodiment, at least the U-shaped heat exchanger 120 is located upstream of the second condenser 123 made of aluminum and the heat exchanger tube 130 is a copper tube. A hydrophilic layer 200 is formed on the outer surface of the portion 131.

The operation of the heat exchange unit according to this embodiment will be explained with reference to FIG. 4. FIG. 4A shows a U-shaped portion 131 of a conventional heat exchanger tube 130 shown as a comparative example. FIG. 4B shows the U-shaped portion 131 of the heat exchanger tube 130 of the heat exchange unit according to the present disclosure. In the evaporator 121, which is the heat exchanger 120 disposed on the most upstream side, air is cooled and dew condensation water is generated. The generated dew water adheres to the surface of the evaporator 121 including the heat transfer tubes 130 and the fins 140. A portion of the condensed water falls from the evaporator 121 into the drain pan 150. Further, another part of the condensed water is scattered downstream by the airflow in the air path and adheres to the surfaces of the first condenser 122 and the second condenser 123.

Here, since the refrigerant flows through the heat transfer tubes 130 of the evaporator 121, the temperature is the lowest, and dew condensation water is likely to occur. The surface of the U-shaped portion 131 of the heat exchanger tube 130 has a large curvature, especially at the tip, and water droplets attached to the surface tend to become spherical, as shown in FIG. 4(a) as a comparative example. When the water droplets adhering to the surface have a nearly spherical shape, they are more likely to be influenced by air currents and be scattered downstream. The condensed water adhering to the surface of the copper heat exchanger 120 contains copper ions eluted from the heat exchanger 120. When condensed water containing copper ions adheres to the surface of the second condenser 123 made of aluminum, the copper ions contained in the condensed water corrode the aluminum of the heat transfer tubes 130, potentially causing refrigerant leakage.

In contrast, in the heat exchange unit according to the present disclosure, a hydrophilic layer 200 is formed on the outer surface of the U-shaped portion 131 of the heat exchanger tube 130, as shown in FIG. 4(b). Therefore, the contact angle of the condensed water adhering to the U-shaped portion 131 becomes small, and the water droplets adhering to the surface are less likely to form a water film and become spherical. Therefore, it is possible to suppress the condensed water adhering to the surface of the U-shaped portion 131 from being scattered downstream due to the influence of airflow. In addition, it is possible for the condensed water adhering to the surface of the U-shaped portion 131 to easily flow down the surface of the heat exchanger 120 to the drain pan 150 below. Therefore, the aluminum of the second condenser 123 on the downstream side can be prevented from being corroded by copper ions contained in the dew condensation water.

Further, when the heat transfer tube 130 of the first condenser 122 is an aluminum tube, the condensed water adhering to the surface of the U-shaped part 131 of the upstream evaporator 121 scatters, and the aluminum of the first condenser 122 is Corrosion caused by copper ions contained in condensed water can be suppressed. In this way, it is possible to suppress corrosion in the first condenser 122 or the second condenser 123 having a heat transfer tube made of aluminum due to the influence of the condensed water generated in the evaporator 121 having the heat transfer tube 130 made of copper. It is.

As a modification of the heat exchange unit according to the present disclosure, as shown in FIG. 4C, the outermost surface of the hydrophilic layer 200 of the U-shaped portion 131 may be made rough. For example, by subjecting the outer surface of the hydrophilic layer 200 to plasma treatment, the outermost surface of the hydrophilic layer 200 can be roughened. By doing so, the contact angle of the condensed water adhering to the U-shaped portion 131 can be further reduced, and the condensed water is further formed into a water film. Therefore, it is possible to further suppress the condensed water adhering to the surface of the U-shaped portion 131 from being scattered downstream due to the influence of the air current.

In addition, regarding the heat exchanger 120 in which the heat exchanger tube 130 is a copper tube, the hydrophilic layer 200 may be provided not only on the surface of the U-shaped portion 131 of the heat exchanger tube but also on the surface of the straight portion 132. Further, the hydrophilic layer 200 may be provided over the entire heat exchanger 120 including the fins 140. Furthermore, when the heat exchange unit includes the heat radiation fins 124 shown in FIG. 3, a hydrophilic layer 200 may be provided on the outer surface of the heat radiation fins 124.

The heat exchanger tubes 130 of the evaporator 121 and the heat exchanger tubes 130 of the first condenser 122 are connected by a connecting tube (not shown). Further, the heat exchanger tubes 130 of the first condenser 122 and the heat exchanger tubes 130 of the second condenser 123 are also connected by a connecting tube (not shown). A hydrophilic layer 200 may be provided on the outer surface of one or both of these connecting pipes.

Next, modifications of the heat exchange unit and dehumidifier 100 according to the present disclosure will be described with reference to FIGS. 5 to 7. In the modification shown in FIG. 5, the evaporator 121 is inclined. As shown in the figure, in this modification, the evaporator 121 is arranged so as to be inclined so that the upper end is on the downstream side than the lower end. By doing so, it is possible to make it easier for the dew water adhering to the surface of the evaporator 121 to flow downward. By making it easier for the condensed water to flow downward, it is possible to reduce the amount of the condensed water containing copper ions scattered to the second condenser 123 made of aluminum disposed downstream.

In the modification shown in FIGS. 6 and 7, the dehumidifier 100 is equipped with a copper ion removing means for removing copper ions contained in dew condensation water. First, in the modification shown in FIG. 6, a water conduit 161 is provided within the casing 110 of the dehumidifier 100. One end of the water pipe 161 is connected to the drain port 151 of the drain pan 150. The other end of the water conduit 161 is connected to the water storage tank 160. The water conduit 161 is an example of a water conduit leading from the drain pan 150 to the water storage tank 160, which is a water storage section. A copper ion processing section 170 is provided within the water conduit 161 . The copper ion processing section 170 is, for example, an ion exchange resin. A copper ion processing section 170 is provided in the water conduit 161 by filling an ion exchange resin so as not to impede the flow of condensed water. The copper ion processing unit 170 is an example of a copper ion removing means that removes copper ions contained in the dew water flowing through the water conduit 161. Thereby, the copper ion concentration of the condensed water stored in the water storage tank 160 can be reduced. In addition, it is possible to reduce the burden on the environment when disposing of water in the water storage tank.

Note that it is preferable to lengthen the path by bending or winding the water conduit 161 in a spiral shape, for example, to increase the amount of ion exchange resin filled as the copper ion processing section 170. By doing so, the duration of the copper ion removal effect by the copper ion treatment section 170 is extended, the frequency of replacement of the water conduit 161 including the copper ion treatment section 170 is reduced, and maintenance work etc. is facilitated. be able to.

In the modification shown in FIG. 7, a copper ion processing section 170 is provided within the water storage tank 160. The copper ion processing section 170 is, for example, an ion exchange resin, as in the example of FIG. The copper ion processing section 170 is removably provided within the water storage tank 160. The copper ion processing unit 170 is an example of a copper ion removing means that removes copper ions contained in the dew water stored in the water storage tank 160. Thereby, the copper ion concentration of the condensed water stored in the water storage tank 160 can be reduced. In addition, it is possible to reduce the burden on the environment when disposing of water in the water storage tank. Although not shown, the copper ion treatment section 170 may be provided within the drain pan 150. By doing so, the copper ions contained in the condensed water in the drain pan 150 can be removed, and the copper ion concentration in the condensed water in the water storage tank 160 can be reduced.

Note that a shielding plate (not shown) may be provided between the first condenser 122 and the second condenser 123 and on the downstream side of the U-shaped portion 131 of the first condenser 122. Further, the shielding plate may be provided between the evaporator 121 and the first condenser 122 and on the downstream side of the U-shaped portion 131 of the evaporator 121. By providing such a shielding plate, the condensed water scattered from one or both of the U-shaped portion 131 of the first condenser 122 and the U-shaped portion 131 of the evaporator 121 is transferred to the second condenser 123 on the downstream side. This can be prevented by a shielding plate.

100 Dehumidifier 110 Housing 111 Compressor 112 Blow fan 120 Heat exchanger 121 Evaporator 122 First condenser 123 Second condenser 124 Radiation fins 130 Heat transfer tubes 131 U-shaped portion 132 Straight portion 133 Joint portion 140 Fin 150 Drain pan 151 Drain port 160 Water storage tank 161 Water pipe 170 Copper ion treatment section 200 Hydrophilic layer

Claims (8)

an evaporator placed in an air path formed inside the casing;
a first condenser disposed downstream of the evaporator in the air path;
a second condenser disposed downstream of the first condenser in the air path,
Each of the evaporator, the first condenser, and the second condenser includes a heat transfer tube through which a refrigerant flows,
The heat exchanger tube includes a plurality of straight parts and a U-shaped part connecting the straight parts,
The heat exchanger tube of the evaporator is a copper tube,
The heat exchanger tube of the first condenser is a copper tube or an aluminum tube,
The heat exchanger tube of the second condenser is an aluminum tube,
The heat exchanger tube, which is a copper tube, is a heat exchange unit in which a hydrophilic layer is formed on the outer surface of the U-shaped portion. The heat exchange unit according to claim 1, wherein the hydrophilic layer has a rough outermost surface. further comprising a radiation fin provided upstream of the evaporator in the air path,
3. The heat exchange unit according to claim 1, wherein the heat radiation fin has a hydrophilic layer formed on an outer surface. The heat exchange unit according to any one of claims 1 to 3, wherein the evaporator is arranged at an angle so that an upper end thereof is located more downstream than a lower end thereof. A dehumidifier comprising the heat exchange unit according to any one of claims 1 to 4. a water storage unit that stores dew condensation water generated in the evaporator;
The dehumidifier according to claim 5, further comprising a copper ion removing means provided in the water storage section and removing copper ions contained in dew condensation water. a drain pan provided below the evaporator;
The dehumidifier according to claim 5, further comprising a copper ion removing means provided in the drain pan and removing copper ions contained in dew condensation water. a water storage unit that stores dew condensation water generated in the evaporator;
a drain pan provided below the evaporator;
6. The dehumidifier according to claim 5, further comprising a copper ion removing means provided in a water conduit leading from the drain pan to the water storage section and removing copper ions contained in condensed water.

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