JP2010236826A - Fin coil device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fin coil device suppressing precipitation of scale in clearance gaps of fins by preventing accumulation of water at a lower part of a fin coil, and preventing corrosion of the fin coil even in a part where the contact of the fin coil with moist air and water droplet is not avoided. <P>SOLUTION: A spacial section 15 through which the air venting for heat exchange passes, is disposed between a casing lower frame section 13a at a lower section of the fin coil surrounded by a frame-shaped casing 13, and the fin 12 and a tube 11, so that a region surrounded by a lower end section of the fin 12 and a casing lower frame section 13a, where the water does not smoothly flows, is eliminated, and the water flows down to a spatial section 15 side from the tube 11 and the fin 12 without blocking the lower end section of the fin 12, thus the water surely flows down without retained, the generation of scale in accompany with retention of the water is suppressed, and the corrosion of the fin 12 and the like due to the scale is prevented, under a situation that the tube 11 and the fin 12 are kept into contact with the moist air and/or water droplet. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to the structure of a fin coil device used as a dry heat exchange section or the like in a cooling tower.

  Generally, for cooling towers installed outdoors for the purpose of cooling water used for circulation in factories and air conditioning equipment, air and water are brought into direct contact at the heat exchange part inside the cooling tower, resulting in a temperature difference between the water and air. With an open-type cooling tower that combines heat transfer utilizing sensible heat, that is, cooling by sensible heat, and evaporation by water itself, that is, cooling by latent heat (evaporation heat), and direct contact between air and circulating water with a heat exchanger There is a closed cooling tower that does not.

  In such a cooling tower, circulating water in the case of an open-type cooling tower and sprayed water that is sprayed on the heat exchange part and adds a cooling effect due to latent heat in the case of a closed cooling tower are in direct contact with the atmosphere and partially evaporate. Therefore, the exhaust air from the cooling tower is heated by heat exchange and is in a wet state containing a large amount of water vapor. As a result, when the ambient air temperature is low and the exhaust air temperature is relatively high, such as in winter, or when the humidity of the external air is high, such as during the rainy season, moisture cannot be properly dissipated to the surroundings, As a result, the water in the exhaust air became supersaturated and became condensed water droplets, which became visible and a phenomenon was seen as if white smoke was blowing out from the cooling tower. Such so-called white smoke generation causes misidentification of fire, air pollution, etc., causes anxiety about the use of cooling towers in the surrounding area, and hinders visibility and becomes a major problem in using cooling towers. It was.

  In order to prevent the generation of such white smoke, conventionally, when the outside air temperature is low, the humidity of the exhaust air is suppressed to prevent condensation due to supersaturation of the moisture in the exhaust air. Various towers are used, for example, the air that has passed through the heat exchange section is heated by a dry heat exchanger provided separately to sufficiently raise the temperature of the exhaust air, and the exhaust air before the exhaust air becomes below the saturation temperature Cooling towers that diffuse water into the outside air have been put into practical use. In general, the dry heat exchanger used is one in which circulating water having a high temperature immediately after the introduction of the cooling tower is introduced and heat is exchanged with the air to warm it. As an example of a white smoke prevention type cooling tower using such a dry heat exchanger, there are those disclosed in JP-A-6-221793 and JP-A-2-109167.

JP-A-6-221793 Japanese Utility Model Publication No. 2-109167

  Conventional white smoke prevention type cooling towers are configured as described in the above-mentioned patent documents, and fin coil type (fin tube type) is often used as a dry heat exchanger used in such cooling towers. The fin coil type heat exchanger 100 is generally configured such that a frame-shaped casing 103 surrounds the upper and lower sides and the right and left sides of a fin coil main body portion composed of a tube 101 and fins 102 to form one unit. In the lower part, the casing lower frame 104 and the lower end of the fin 102 were in contact with each other (see FIGS. 6 and 7).

  On the other hand, the air whose temperature has risen after passing through the wet heat exchange section of the cooling tower is humid air, and may contain some water droplets of the circulating water. On the surface, condensation of water and adhesion of water droplets occur, and these water droplets flow down the surfaces of the tubes and fins forming the coil. The water droplets that flow down eventually reach the lower frame of the casing, but the water enters the region surrounded by the lower fins and the upper surface of the lower casing frame that is difficult to flow out of the water. It stays in the upper part. When moisture evaporates from the water thus retained, scale components such as calcium dissolved in the circulating water are deposited to form scale. This scale accumulates in the area surrounded by the upper surface of the casing lower frame part and the fins, and when such a scale is in a state of forming an oxygen concentration cell together with the metal parts forming the members such as tubes and fins, the fins etc. There was a problem that the corrosion of the metal member would proceed.

  Furthermore, the quality of circulating water in the cooling tower has deteriorated as the frequency of water exchange has decreased due to the recent trend toward water conservation, and the concentration rate of dissolved components has increased significantly, and such water accumulates at the bottom of the fin coil. A fin coil that uses a metal material that is easily corroded, such as aluminum, that is relatively corrosive as a standard component, has a high risk of corroding in a short time due to this scale, and countermeasures have been strongly demanded. .

  The present invention has been made to solve the above-mentioned problems, and prevents water from accumulating in the lower portion of the fin coil, suppresses the deposition of scale in the gaps between the fins, and avoids contact with damp air or water droplets. An object of the present invention is to provide a fin coil device capable of preventing corrosion of a fin coil even at a place where it cannot be done.

  A fin coil device according to the present invention includes a coil for heat exchange assembled with a tube having plate-shaped fins around it, and a frame-shaped casing integrated with the coil, and a predetermined heat flowing through the coil. In the fin coil device for exchanging heat between the exchange medium and air passing around the coil, at least a predetermined dimension larger than the tube diameter is provided between the lower end portion of the fin and the lower frame portion of the casing, and the lower side of the fin The space through which air passes is set.

  As described above, according to the present invention, the space portion through which air to be ventilated for heat exchange passes is provided between the casing lower frame portion and the fin in the lower portion of the fin coil surrounded by the frame-shaped casing, The area surrounded by the lower end and the casing lower frame is less likely to flow of water, and the lower end of the fin is not blocked, allowing water to flow down from the tube or fin toward the space. And / or in the state of contact with water droplets, water generated on the surface of the tube or fin can be surely flowed down so as not to stay between the fins, and generation of scale due to water retention can be suppressed. , It is possible to prevent the corrosion of tubes and fins that progress due to the scale, and the maintenance effort and cost for corrosion can be reduced.

Moreover, the fin coil device according to the present invention does not provide the tube in a region between the lower end portion of the fin where the space portion is set and the casing lower frame portion, if necessary.
As described above, according to the present invention, the tube is also excluded from between the casing lower frame portion and the fin lower end portion to secure a wide space portion, thereby facilitating the further flow of water downward from the tube or the fin. The water generated on the surfaces of the tubes and fins can surely reach the lower frame of the casing to be eliminated, and the generation of scales and the corrosion of the tubes and fins that progress due to the scales can be more reliably prevented.

Further, the fin coil device according to the present invention includes a resistor that has a ventilation structure and covers the space portion as necessary.
As described above, according to the present invention, the resistor that covers the space portion between the casing lower frame portion and the fins and the tube is disposed, and accompanying the passage of the resistor to the air that is about to pass through the space portion. By giving a predetermined ventilation resistance, the amount of air flowing in the space can be adjusted, and the amount of air passing through the area inside the casing can be equalized in each part in the vertical direction. Inflow can be prevented, and air can be evenly passed through the fin coil portion as the heat exchange portion, so that the heat exchange efficiency can be improved.

In addition, the fin coil device according to the present invention may be configured such that the second fin made of a hardly corrosive material having good thermal conductivity is capable of conducting heat to the fin and / or the tube in the space portion as necessary. A plurality are arranged.
As described above, according to the present invention, the second fin that is unlikely to be corroded and has good thermal conductivity is disposed in the space portion in a state where heat can be transferred from the tube or the fin. By ensuring that heat exchange between the internal heat exchange medium and air can be performed via the second fin even in the space, the maximum contact area with the air as a heat exchanger is ensured while avoiding corrosion of the tubes and fins. Thus, the heat exchange performance can be further improved.

Further, the fin coil device according to the present invention has a shape in which the upper surface of the lower frame portion of the casing is inclined with respect to the air passing direction, if necessary.
As described above, according to the present invention, the upper surface of the casing lower frame portion is inclined to facilitate the flow of water on the upper surface of the lower frame portion, so that the water flowing down from the fin coil can be hardly accumulated on the lower frame portion, Scaling on the lower frame and the accompanying corrosion can be suppressed.

Further, the fin coil device according to the present invention has a drain hole formed in the upper surface of the lower frame portion of the casing as necessary.
As described above, according to the present invention, a water drainage hole is formed in the upper surface of the casing lower frame portion so that the water that has reached the lower frame portion can be easily discharged downward. It is possible to make it difficult to accumulate on the frame portion, and it is possible to suppress the generation of scale on the lower frame portion and the progress of corrosion associated therewith.

It is a schematic block diagram of the cooling tower using the fin coil apparatus which concerns on one Embodiment of this invention. It is a front view of the fin coil device concerning one embodiment of the present invention. It is a principal part enlarged front view of the fin coil apparatus which concerns on one Embodiment of this invention. It is AA sectional drawing of FIG. It is a principal part enlarged front view of the fin coil apparatus which concerns on other embodiment of this invention. It is a front view of the conventional fan coil apparatus. It is a principal part enlarged front view of the conventional fin coil apparatus.

  Hereinafter, an embodiment of the present invention will be described with reference to FIGS.

  As shown in the respective drawings, a fin coil device 10 according to this embodiment includes a tube 11 forming a flow path of circulating water as a heat exchange medium, and a plurality of plates that are integrated around the tube 11 and arranged in parallel. A fin-shaped fin 12, a frame-shaped casing 13 integrated with a coil composed of the tube 11 and the fin 12, and a resistor plate 14 as the resistor covering the space 15 above the lower frame portion 13a of the casing 13; As a dry heat exchange part of the cooling tower 20, heat exchange is performed between the circulating water circulating in the tube 11 and the air ventilated in the cooling tower 20.

  The tube 11 and the fins 12 are arranged in a state where a plurality of rows are arranged in parallel at predetermined intervals, and a large number of thin metal plate fins 12 perpendicular to the tube 11 are arranged in the longitudinal direction of the tube 11. The tube 11 is a well-known fin coil in which the tubes 11 and the fins 12 are combined together so that each row of the tubes 11 penetrates at a predetermined interval at a plurality of locations of one fin 12. Omitted.

  The casing 13 is formed of a metal rectangular frame having a size that surrounds the integrated tube 11 and the fins 12, and each end of the tube 11 in the longitudinal direction passes through the side frame portion so as to be integrated therewith. It is the structure which is made. Between the lower frame portion 13a of the casing 13 and the integrated tube 11 and the lower end of the fin 12, a space portion 15 has a predetermined dimension larger than the tube 11 diameter, preferably one or more of the tubes 11. A gap is provided by a predetermined dimension corresponding to the arrangement interval for the row, and air passes through the space portion 15 without contacting the tube 11 and the fins 12. Even if the space portion 15 is too large, the effective area of the fin coil portion is narrowed and the heat exchange efficiency is lowered.

  The resistance plate 14 is a plate-like body made of a porous material that allows air to pass, such as a punching plate that is sized to cover the space portion 15, and is attached to the lower frame portion 13 a of the casing 13. It is a configuration. In the space portion 15, since the tubes 11 and the fins 12 do not exist, the ventilation resistance is reduced as it is, and the air that is going to pass through the fin coil device 1 is concentrated and flows into the space portion 15. By providing the resistance plate 14 that covers the space portion 15, the air flow resistance in the fin coil portion inside the casing 13 is made uniform by giving the air passing through the space portion 15 the same ventilation resistance as that of the fin coil portion. It is. It is preferable that the ventilation resistance of the resistance plate 14 is substantially matched with the ventilation resistance of the fin coil portion.

  The lower portion of the resistor plate 14 is bent to have a shape along the surface of the casing lower frame portion 13a, and is arranged with a gap of a predetermined distance from the surface of the lower frame portion 13a. Through the gap portion, the lower frame portion 13a is disposed. The water that has reached the upper surface can flow out to the outside (see FIG. 4).

  The fin coil device 10 according to the present embodiment serves as a dry heat exchange unit of the cooling tower 20 to circulate the circulating water from the circulation path outside the cooling tower in the tube 11 in a state of contact with humid air or water droplets. Heat exchange is performed between the water and the air passing around the tube 11 through the tube 11 and the fins 12.

  The cooling tower 20 is provided with a heat exchange part 21 having a thin plate-like filler 21a arranged in parallel in a standing state, and is provided on the upper side of the heat exchange part 21 to be supplied with circulating water. The upper water tank 22 that is distributed and dropped to each part of the heat exchanging part 21, the lower water tank 23 that is disposed below the heat exchanging part 21 and collects the circulating water that has passed through the heat exchanging part 21, and the circulating water from the lower water tank 23 A fan 25 that is taken out and is repeatedly sent to the upper water tank 22 through a predetermined circulation path, and a fan 25 that is disposed above the center of the lower water tank 23 and that passes through each filler 21a of the heat exchanging portion 21 with an induced air. It is the structure of the well-known open type cooling tower provided with these.

  The heat exchanging portion 21 is formed by arranging a large number of substantially plate-like fillers 21a in parallel, and is disposed in a pair above the lower water tank 23 across the space below the fan 25, and circulates in a gap between the fillers 21a. This is a known configuration in which water is dropped and external air is passed in the lateral direction to exchange heat on the surface of the filler 21a, and detailed description thereof is omitted. The outside air that has passed through the heat exchanging portion 21 is passed to the fan 25 side along the outside air outlet portion inside the cooling tower of the heat exchanging portion 21, while water droplets scattered from the inside of the heat exchanging portion 21 are received. An eliminator 26 is provided to make it difficult for water droplets to scatter from the outside to the downstream side in the outside air outflow direction. The fin coil device 10 is disposed in the space in the cooling tower 20 further downstream of the eliminator 26.

  The upper water tank 22 is formed of a shallow box-like body having a large number of small holes at the bottom, and is supplied with circulating water that has left the lower water tank 23 and passed through a predetermined circulation path above the heat exchange section 21. The circulating water is a well-known configuration in which a predetermined amount of water is distributed and dropped uniformly from a large number of holes at the bottom toward each part of the heat exchanging portion 21, and detailed description thereof is omitted.

  The lower water tank 23 is disposed on a support frame 23a that is fixedly installed, receives the circulating water that has flowed down, and collects it while temporarily storing it. ), And pipes for introducing and sending circulating water (not shown), etc., are connected to each other, so that a predetermined amount of circulating water can be stored, and detailed description thereof is omitted. Further, the fan 25 passes outside air from the lateral direction to each heat exchanging portion 21 through the central space sandwiched between the pair of heat exchanging portions 21 below and passes through the heat exchanging portions 21 sideways. The exhaust is blown upward and discharged, and detailed description is omitted.

  Next, the usage state of the cooling tower using the fin coil apparatus based on the said structure is demonstrated. In a normal cooling tower operation state, heat is absorbed by a refrigerator or an air conditioner as a heat exchange medium, and when the circulating water to be cooled is taken out from a predetermined circulation path and returned to the cooling tower 20, the circulating water First enters the water distribution pipe 24 in the cooling tower 20, and the circulating water reaches the fin coil device 10 as a dry heat exchange section via this. The circulating water is heat-exchanged with air in the fin coil device 10 and then goes to the upper water tank 22. In addition, the distribution pipe 24 in the cooling tower 20 is provided with a switching portion between a pipe line that directly goes to the upper water tank 22 side and a pipe line that reaches the upper water tank 22 through the fin coil device 10, and generation of white smoke is expected. It is also possible to pass the circulating water through the fin coil device 10 only at a certain time.

  The circulating water that has reached the upper water tank 22 from the fin coil device 60 passes through the holes at the bottom in a predetermined time, and is dropped toward the heat exchanger 21 below. Circulating water dropped from the upper water tank 22 and reaching the heat exchanging portion 21 proceeds to the gaps between the fillers 21a and flows down along the filler 21a, while being transverse to the heat exchanging portion 21. Contact with external air to be introduced and ventilated. Circulating water is cooled mainly by the cooling action due to heat transfer (sensible heat) accompanying the temperature difference between air and circulating water and the cooling action due to the evaporation heat (latent heat) of the circulating water, while the air is reversed by heat exchange. The temperature will be raised. In this way, the circulating water is cooled by the heat exchanging unit 21 and then reaches the lower water tank 23 and is collected. The circulating water collected in the lower water tank 23 enters the circulation path again from the water tank outlet, absorbs heat by a refrigerator, an air conditioner, or the like as a heat exchange medium, and then enters the water distribution pipe 24 to repeat the above process.

  On the other hand, the air passing through the heat exchanging unit 21 by the attraction of the fan 25 becomes wet air by taking in the evaporated circulating water in the heat exchanging unit 21 and reaches the fin coil device 10. Further, a part of the circulating water flowing down the surface of the filler 21a of the heat exchange unit 21 passes through the eliminator 26 together with the air passing through the heat exchange unit 21 as water droplets and reaches the fin coil device 10.

  The air that is ventilated through the fin coil device 10 undergoes non-contact dry heat exchange (sensible heat exchange) via the tube 11 and the fins 12 with the circulating water in the tube 11, and the temperature is kept while the moisture content in the air remains unchanged. By rising, the relative humidity of the exhaust air is sufficiently lowered.

  In this way, the water in the exhausted air that has passed through the heat exchange section is almost saturated, such as in the winter when the outside air temperature is low and in the rainy season when the outside air humidity is high. Even in the situation where white smoke is expected to occur, by passing the fin coil device 10, the moisture in the exhaust air whose temperature has risen is less likely to become saturated even if it comes into contact with the low temperature outside air immediately after being discharged from the fan 25, Exhaust air can be diffused to the outside air without generating white smoke.

  Further, in the fin coil device 10, water droplets formed by condensation in the fin coil portion in the casing 13 or water droplets carried along with the air and attached to the fin coil portion flow down the surface of the tube 11 or the fin 12 and the casing. 13 reaches the lower frame portion 13a, but the upper surface of the lower frame portion 13a is not in contact with the lower end portions of the tubes 11 and the fins 12, so that water hardly collects on the lower frame portion 13a, and the lower portion from the lower frame portion 13a. Will flow down into the lower water tank 23 of the tank. By preventing the water from collecting on the lower frame portion 13a in this way, scale deposition can be suppressed and corrosion of the tube 11 and the fin 12 can be prevented.

  Although the tube 11 and the fins 12 do not exist in the space portion 15 above the lower frame portion 13a, a large amount of air flows through the space portion 15 by providing the resistance plate 14 and providing appropriate ventilation resistance. The airflow state is made uniform over the entire fin coil portion in the casing 13 so that air can be passed smoothly and heat can be exchanged efficiently.

  As described above, in the fin coil device according to the present embodiment, ventilation is performed between the casing lower frame portion 13a, the fins 12 and the tubes 11 at the lower portion of the fin coil surrounded by the frame-shaped casing 13 for heat exchange. The space 15 through which the air passes through is provided, the area where the water does not flow easily surrounded by the lower end portion of the fin 12 and the casing lower frame portion 13a is eliminated, and the lower end portion of the fin 12 is not blocked. Therefore, in the situation where the tube 11 and the fin 12 are in contact with moist air and / or water droplets, the water generated on the surface of the tube 11 and the fin 12 is surely caused to flow down, thereby causing the tube 11 and the fin 12 to flow down. It is possible to prevent stagnation in the middle, and it is possible to suppress the generation of scale due to stagnation of water, and the progress of the scale is caused by the scale. And can prevent corrosion of the fins, it is suppressed labor and maintenance costs against corrosion. In addition, a resistance plate 14 that covers the space portion 15 is provided to give a predetermined ventilation resistance that accompanies the passage of the resistance plate 14 to the air that is about to pass through the space portion 15. By adjusting the inflow amount, the amount of air passing through the region inside the casing 13 can be equalized in each part in the vertical direction, preventing excessive air from flowing into the space portion 15, and the air being a heat exchange portion. As a result, the heat exchange efficiency can be increased.

  In the fin coil device according to the above-described embodiment, an example in which the fin coil device is installed in the cooling tower 20 as a dry heat exchange unit for preventing white smoke in the cooling tower 20 is shown. When heat exchange is performed without directly contacting the heat exchange medium and the gas, it can be widely used as a heat exchanger in situations where it can come into contact with gas containing moisture in the gas phase such as moist air or water droplets in the gas. Even if water adheres to the coil, the water can be prevented from accumulating in the casing lower frame portion, and corrosion of the tubes and fins can be prevented.

  In the fin coil device according to the embodiment, the space portion 15 on the upper side of the casing lower frame portion 13a is not provided with either the tube 11 or the fin 12. However, the present invention is not limited thereto, and the upper fin for the tube is not limited thereto. It is possible to provide the same as the coil portion and not to provide only the fins. A coil made of a tube can be manufactured in the same manner as before, and heat exchange by the tube in the space can be expected.

  Further, in the fin coil device according to the embodiment, the resistance plate 14 is provided on the upper portion of the casing lower frame portion 13a so as to cover the space portion 15. However, the present invention is not limited thereto, and as shown in FIG. The second fin 16 made of, for example, stainless steel, titanium, copper, or the like, which is made of a material that is unlikely to corrode and has good thermal conductivity, is provided in FIG. Thus, heat exchange between the circulating water in the tube 11 and air can be performed also in the space portion 15 via the second fins 16, and the contact area with the air as a heat exchanger is avoided while avoiding corrosion of the tubes 11 and the fins 12. The heat exchange performance can be further improved by ensuring the maximum. The arrangement pitch of the second fins 16 is not limited to twice the pitch of the upper fins 12 as shown in FIG. It may be set appropriately so as to obtain a proper ventilation resistance. Furthermore, in the open state, the air inflow amount to the space portion 15 having a small ventilation resistance is not so large depending on the air flow path state on the upstream side or the downstream side of the fin coil device, and is excessive in terms of air inflow in the entire fin coil. If it is expected that the non-uniform state will not be brought about, a configuration may be adopted in which the space portion 15 is left open without providing a resistance plate or the like.

  In the fin coil device according to the embodiment, the arrangement relationship between the tube 11 and the fin 12 and the casing 13 is such that the space portion 15 is present between the upper side of the lower frame portion 13a and the tube 11 and the fin 12 from the beginning. However, the present invention is not limited to this, and in the fin coil of the conventional structure in which the lower ends of the tubes and fins reach the upper side of the lower frame portion of the casing, the lowermost tubes and fins are cut out to create a space portion. A resistance plate or the like can be attached. In particular, if it is applied as a countermeasure structure in the case where corrosion has already occurred in the lowermost tube and fin of the fin coil, further progress of corrosion can be reliably prevented.

  Further, in the fin coil device according to the embodiment, the upper surface of the lower frame portion 13a of the casing 13 is formed in a simple flat plate shape. It can also be configured to have a shape that is inclined with respect to the lower frame part, or a water drainage hole is formed in the upper surface of the lower frame part, so that water can flow downward from the upper surface of the casing lower frame part, thereby flowing down from the fin coil. Water is less likely to accumulate on the lower frame portion, and scale generation on the lower frame portion and the accompanying corrosion can be prevented.

DESCRIPTION OF SYMBOLS 10 Fin coil apparatus 11 Tube 12 Fin 13 Casing 13a Lower frame part 14 Resistance board 15 Space part 16 2nd fin 20 Eliminator 21 Heat exchange part 21a Filler 22 Upper water tank 23 Lower water tank 24 Water distribution pipe 25 Fan 26 Eliminator

Claims (6)

A coil for heat exchange assembled with a tube having plate-like fins around it, a frame-shaped casing integrated with the coil, a predetermined heat exchange medium circulating in the coil, and air passing around the coil In the fin coil device that exchanges heat with
A fin coil device characterized in that at least a predetermined dimension larger than a tube tube diameter is provided between the lower end portion of the fin and the lower frame portion of the casing, and a space portion through which air passes is set below the fin. The fin coil device according to claim 1,
The fin coil device is characterized in that the tube is not provided in a region between the lower end portion of the fin and the casing lower frame portion in which the space portion is set. In the fin coil device according to claim 1 or 2,
A fin coil device comprising a resistor having a ventilation structure and covering the space. In the fin coil device according to claim 1 or 2,
One or a plurality of second fins made of a hardly corrosive material having good thermal conductivity are disposed in the space so as to be capable of conducting heat to the fins and / or tubes. In the fin coil device according to any one of claims 1 to 4,
A fin coil device having a shape in which an upper surface of a lower frame portion of the casing is inclined in an air passage direction. In the fin coil device according to any one of claims 1 to 4,
A fin coil device, wherein a drain hole is formed in an upper surface of a lower frame portion of the casing.

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