Air conditioning device

Abstract

To provide an air conditioner having a freeze destruction prevention function that prevents destruction of a heat exchange coil of a heat exchanger even if residual water in the heat exchange coil freezes. [Solution] The above problem is solved by the following: a first chamber 21, a second chamber 22, and a partition plate 20 separating the first chamber 21 and the second chamber 22 are installed in the housing 2 inside the air conditioning unit 1; and the heat exchanger 4 is arranged in the first chamber 21 so that the peripheral portion 29 of the outside air outlet surface 18 of the heat exchanger 4 is in close contact with the edge of the opening 23 of the partition plate 20. As a result, the straight pipe section 8 and the U-bend section 10 are exposed to the outside air and freeze at the same time, making it less likely that unfrozen areas will occur in the heat exchange coil 13, and as a result, freezing damage to the heat exchange coil 13 is less likely to occur.

Description

[Technical field]

[0001] The present invention relates to an air conditioner. [Background technology]

[0002] Air conditioners are devices that circulate outdoor air and indoor air, and supply outdoor air that has been cooled or heated by a heat exchanger to the room. Air conditioners need to operate stably regardless of the season, but particularly in cold regions in winter, when the temperature drops below freezing, there are frequent accidents in which the water in the heat exchanger coils installed in the air conditioner freezes and the coils are destroyed. Such freezing accidents lead to the stop of the air conditioning function, and the coils need to be repaired or replaced, etc., and recovery takes time, which develops into a serious problem in cold regions.

[0003] In such areas, measures are taken to prevent the heat exchanger coil from freezing, such as using refrigerants, anti-freeze heaters, operating a circulation pump to keep water flowing continuously, or conversely, draining the water from inside the coil. However, once the water in the coil freezes, the heat exchanger coil can be destroyed or the water can thaw due to rising temperatures, causing water leaks.

[0004] Methods for preventing freezing of water inside a heat exchanger coil in winter are disclosed in Patent Documents 1 and 2 listed below.

[0005] The method of preventing freezing of a heat exchanger disclosed in Patent Document 1 is characterized by comprising a heat exchanger and a blower that exchange heat between cooling water, which is a heat medium, and air, and supplying nitrogen gas at a predetermined pressure to a coil through which the cooling water that constitutes the heat exchanger flows to drain the cooling water inside the coil, and after draining the cooling water, maintaining the coil in a state in which nitrogen gas is pressurized and sealed at a predetermined pressure.

[0006] The anti-freezing operation method for a cooling heat exchanger disclosed in Patent Document 2 shows a method in which the ventilation and water flow mode of the cooling heat exchanger is switched to a parallel flow mode and the amount of anti-freezing water flowing is adjusted to adjust the temperature of the outside air at the ventilation duct outlet of the cooling heat exchanger or the temperature of the anti-freezing water at the water passage outlet of the cooling heat exchanger to a set anti-freezing temperature. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] JP 2006-57867 A [Patent Document 2] JP 2012-154543 A Summary of the Invention [Problem to be solved by the invention]

[0008] In the method for preventing freezing of a heat exchanger in Patent Document 1, in order to supply nitrogen gas at a predetermined pressure into the coil and drain the cooling water remaining in the coil, it is necessary to provide a nitrogen gas supply source, a supply pipe, and a pressure regulating valve, and the nitrogen gas supply pressure during drainage is adjusted to be higher than the pressure of the nitrogen gas when pressurized and sealed in. In addition, in order to maintain the state in which nitrogen gas is pressurized and sealed in the coil after drainage, it is necessary to supply nitrogen gas continuously.

[0009] The cooling heat exchanger of Patent Document 2 adjusts the opening of an anti-freeze control valve based on detection information from an outlet temperature sensor, and adjusts the amount of anti-freeze water flowing through the water passage of the cooling heat exchanger, thereby adjusting the temperature of the outside air at the ventilation channel side outlet of the cooling heat exchanger to a set anti-freeze temperature.

[0010] Furthermore, during anti-freeze operation, the amount of anti-freeze water passing through the water passage of the cooling heat exchanger is adjusted by adjusting the opening of the anti-freeze control valve, and the adjustment range of the opening of the anti-freeze control valve is specified to a range above the set lower limit opening so that the adjustment range of the water flow rate is limited to a water volume range where the flow velocity of the anti-freeze water in the water passage of the cooling heat exchanger is equal to or higher than the set lower limit flow velocity.

[0011] The operation control device of the outdoor air-conditioning unit in Patent Document 2 increases the above-mentioned set lower limit opening degree based on the detection information of the inlet temperature sensor that detects the temperature of the outside air at the ventilation duct inlet of the cooling heat exchanger, as the temperature of the outside air at the ventilation duct inlet becomes lower.

[0012] That is, to perform anti-freeze operation for the cooling heat exchanger, it is necessary to adjust the amount and speed of water flow based on information obtained from a temperature sensor that detects the outside air temperature.

[0013] However, the methods for preventing freezing of heat exchange coils as described in Patent Documents 1 and 2 involve adjusting various devices installed in the air conditioning system according to the situation each time in order to prevent freezing, and even if such measures are taken, no disclosure is made about what to do if freezing does occur.

[0014] SUMMARY OF THE PRESENT EMBODIMENT An object of the present invention is to provide an air conditioner having a freeze damage prevention function that prevents the coil from being destroyed even if the residual water in the heat exchanger coil freezes in winter. [Means for solving the problem]

[0015] The present invention, which has solved the above problems, is as follows.

[0016] (First aspect) The device has a housing, the housing includes a first chamber, a second chamber, and a partition plate having an opening that separates the first chamber from the second chamber; A heat exchanger is installed in the first chamber, The heat exchanger has a fin portion formed by stacking a plurality of fins and a heat exchange coil, and exchanges heat between outside air and a circulating fluid flowing through the heat exchange coil, The heat exchange coil has a continuous flow path formed by a straight pipe section made of a plurality of straight pipes and a U-bend section made of a plurality of U-bend pipes, both ends of the heat exchange coil are joined to a header section, the straight pipe section is provided penetrating through the fin section, and the U-bend section protrudes outward from the fin section, The straight pipe portion has a cross section that can expand under internal pressure, Outside air enters the first chamber, passes through the fin portion, enters the second chamber through the opening, and exits the second chamber, The periphery of the surface of the fin portion on the outside air outlet side is closed by the edge of the opening. An air conditioning device characterized by:

[0017] (Action and effect) Heat exchange occurs between the outside air and the circulating fluid within the air conditioning system. Specifically, the circulating fluid flows through the heat exchange coil of the heat exchanger, and the warmed outside air can be brought into the room as it passes through the coil. Because the heat exchanger's fins are made up of multiple layers, it is possible to ensure a wide passage for the outside air and increase the area in which heat exchange occurs, making it easier to exchange heat efficiently. For this reason, heat exchange is more likely to occur in the straight pipe section of the heat exchange coil where the fins penetrate, and less likely to occur in the U-bend section protruding from the fins. The straight pipe section of the heat exchange coil of the first embodiment has a cross-section that can expand when subjected to internal pressure, so that even if outside air that has dropped below freezing passes through the straight pipe section, causing the residual water in the circulating fluid in the coil to freeze and causing the pressure of the residual water in the unfrozen section to rise, there is a high probability that the pipe will expand and release the pressure, making it easier to prevent the pipe from being destroyed. The heat exchange coil has multiple U-bend pipes joined to the ends of multiple straight pipes, and the pipe end faces to which the U-bend pipes are not joined are joined to a header section, thereby forming a continuous flow path. The ends of the straight pipes and the header section can also be joined via a header connection pipe.

[0018] In the air conditioner of the present invention, the first and second chambers and the partition plate separating the first and second chambers are housed in the housing. Outside air enters from the first chamber, passes between the stacked fins of the heat exchanger, passes through the opening of the partition plate, enters the second chamber, and exits from the second chamber to the outside of the air conditioner. Since the heat exchanger is installed in the first chamber, the entire heat exchanger is exposed to the outside air. The edge of the opening of the partition plate covers the periphery of the surface of the outside air outlet side of the fin part of the heat exchanger, so that the outside air passes through the fin and enters the second chamber. Therefore, when the outside air drops below freezing point, the entire heat exchanger is cooled, and the outside air passes not only through the straight pipe part where the fin part is present, but also through the U-bend part where the outside air does not normally pass, and the straight pipe part and the U-bend part of the heat exchanger coil are cooled uniformly, the residual water in the coil freezes uniformly, and unfrozen parts are unlikely to exist, so that the pressure of the residual water in the unfrozen part is unlikely to increase, and the coil is unlikely to be destroyed by freezing.

[0019] (Second Aspect) The device has a housing, The heat exchanger is installed in the housing, The heat exchanger has a fin portion formed by stacking a plurality of fins and a heat exchange coil, and exchanges heat between outside air and a circulating fluid flowing through the heat exchange coil, The heat exchange coil has a continuous flow path formed by a straight pipe section made of a plurality of straight pipes and a U-bend section made of a plurality of U-bend pipes, both ends of the heat exchange coil are joined to a header section, and the entire U-bend section and the straight pipe section are provided within the fin section, Both ends of the heat exchange coil are joined to the header portion, The straight pipe portion has a cross section that is expandable under internal pressure. An air conditioning device characterized by:

[0020] (Action and effect) As in the first embodiment, heat exchange occurs between the outside air and the circulating fluid within the air conditioning system. Specifically, the circulating fluid flows through the heat exchange coil of the heat exchanger, and the warmed outside air can be brought into the room as it passes through the coil. Since the fins of the heat exchanger are arranged in a stacked manner, a wide passage for outside air can be secured, and the area for heat exchange is increased, making it easy to perform heat exchange efficiently. Unlike the first embodiment, in the second embodiment, the fins penetrate not only the straight pipe section of the heat exchange coil but also the U-bend section, and the fins cover the entire coil, so the number of fins is increased compared to the first embodiment, making it easier to perform heat exchange in the entire heat exchange coil. In this embodiment, when the outside air that has dropped below freezing passes through the fins, the temperature of the entire U-bend section and the straight pipe section of the heat exchange coil through which the fins penetrate drops at the same time, and the entire U-bend section and the straight pipe section can be frozen at the same time, so that unfrozen sections are less likely to occur, and pressure rise in the unfrozen sections is less likely to occur, resulting in an effect that the coil is less likely to be destroyed.

[0021] As with the heat exchange coil of the first embodiment, the straight tube of the straight tube section has a cross-section that can expand when subjected to internal pressure, so that even if outside air that has dropped below freezing passes through the straight tube section, causing the residual water in the circulating fluid in the coil to freeze and causing the pressure of the residual water in the unfrozen section to rise, there is a high probability that the tube will expand and release the pressure, making it easier to prevent the tube from being destroyed. The heat exchange coil has multiple U-bend pipes joined to the ends of multiple straight pipes, and the pipe end faces to which the U-bend pipes are not joined are joined to a header section, thereby forming a continuous flow path. The ends of the straight pipes and the header section can also be joined via a header connection pipe.

[0022] (Third Aspect) the housing includes a first chamber, a second chamber, and a partition plate having an opening that separates the first chamber from the second chamber; The heat exchanger is disposed in the first chamber, Outside air enters the first chamber, passes through the fin portion, enters the second chamber through the opening of the partition plate, and exits the second chamber, An air conditioner according to a second aspect, wherein a peripheral portion of a surface of the fin portion on the outside air outlet side is closed by an edge of the opening.

[0023] (Action and effect) This refers to a form that combines the features of the first and second forms. In other words, this is an air conditioner in which the fins of the heat exchanger are inserted into the entire U-bend section and the straight pipe section, the first and second chambers of the air conditioner are separated by a partition plate with an opening, and the heat exchanger is disposed in the first chamber so that the periphery of the surface on the outside air outlet side of the heat exchanger contacts the edge of the opening of the partition plate. In addition to the ingenuity in the position of the partition plate, the entire U-bend section and the straight pipe section inserted into the fin are exposed to the outside air at the same time, which makes it more likely that the entire U-bend section and the straight pipe section will be brought into the same condition than in the first and second embodiments. This increases the likelihood that the straight pipe section and U-bend section will be cooled and frozen more evenly, further reducing the possibility of unfrozen sections being created, and makes it less likely that damage will occur due to an increase in pressure in the unfrozen part of the coil than in the first and second embodiments.

[0024] (Fourth aspect) the housing includes a first chamber, a second chamber, and a partition plate having an opening that separates the first chamber from the second chamber; The heat exchanger is disposed in the second chamber, Outside air enters the first chamber, enters the second chamber through the opening of the partition plate, passes through the fin portion, and exits the second chamber, An air conditioner according to a second aspect, wherein a peripheral portion of a surface of the fin portion on the outside air inlet side is closed by an edge of the opening portion.

[0025] (Action and effect) This is an embodiment that combines the features of the first and second embodiments and is different from the third embodiment. In other words, the fins of the heat exchanger are inserted into the entire U-bend section and the straight pipe section, the first and second chambers of the air conditioner are separated by a partition plate with an opening, and the heat exchanger is disposed in the second chamber so that the periphery of the surface on the outside air inlet side of the heat exchanger contacts the edge of the opening of the partition plate. The effects of the fourth aspect are similar to those of the third aspect.

[0026] (Fifth aspect) The air conditioning device according to the first or second aspect, wherein a cross section of at least one of the pipes of the U-bend portion or the header portion has a shape that can expand when subjected to internal pressure.

[0027] (Action and effect) In the fifth aspect, since the cross section of at least one of the pipes in the U-bend section or the header section is a shape that can expand under internal pressure, in the heat exchanger of the first or second aspect, even if the straight pipe section freezes first and at least one of the U-bend section or the header section remains unfrozen, and the internal pressure of the unfrozen section rises, the pipes in either the U-bend section or the header section, or both, are expandable, so that the increased internal pressure can be released into the pipe, and the coil is less likely to be destroyed. The expandable shape is, for example, an ellipse or an oval shape, and when it expands into an approximately circular shape such as a perfect circle or a circle, the cross-sectional area becomes large, so the internal pressure is easily released and the possibility of the coil being destroyed is low. Shapes close to disks such as ellipses and ovals are flattened shapes, so when internal pressure is applied, a force is applied in the direction in which it expands into an approximately circular shape and the cross-sectional area becomes large. Of course, the shape is not limited to these as long as it is expandable.

[0028] (Sixth aspect) The inspection tool for an air conditioner according to the first or second aspect, for checking the diameter of the straight pipe portion when the straight pipe portion is frozen.

[0029] (Action and effect) According to the sixth aspect, when a straight pipe section, whose cross section is shaped to be expandable under internal pressure, freezes, it is possible to easily check whether there is an expanded portion of the pipe, and to determine whether the pipe or the heat exchanger needs to be replaced or repaired. A tool having a space large enough to fit the diameter of the straight pipe can be inserted between the stacked fins to check whether the straight pipe section has expanded. If the tool can be inserted, the pipe maintains its original shape, and if the tool cannot be inserted, it is determined that the pipe has expanded and deformed, and it is possible to decide to replace or repair the heat exchange coil or the heat exchanger itself. Effect of the Invention

[0030] According to the present invention, it is possible to provide an air conditioner in which the coil is unlikely to be destroyed even if the water in the heat exchanger coil freezes. [Brief description of the drawings]

[0031] [Figure 1] FIG. 1 is a perspective view of a typical air conditioner. [Diagram 2] 1 is a schematic diagram of a heat exchanger according to the present invention; [Diagram 3] FIG. 3 is a side view of the heat exchanger in FIG. 2. [Figure 4] FIG. 2 is a front view of a fin according to the present invention. [Diagram 5] FIG. 1 is a plan view of a typical air conditioner. [Figure 6] FIG. 1 is a plan view of an air conditioner according to a first embodiment. [Figure 7] FIG. [Figure 8] FIG. 3 is a cross-sectional view of a typical heat exchanger taken along line WW in FIG. 2. [Figure 9] FIG. 9 is a cross-sectional view of the heat exchange coil of FIG. [Figure 10] FIG. 3 is a cross-sectional view of the heat exchanger according to the second, third and fourth embodiments taken along the line WW in FIG. 2. [Figure 11] FIG. 11 is a plan view of a heat exchanger according to a third embodiment. [Figure 12] FIG. 13 is a plan view of a heat exchanger according to a fourth embodiment. [Figure 13] FIG. 3 is a cross-sectional view of the heat exchanger according to the fifth embodiment taken along the line WW in FIG. 2. [Figure 14] 2. FIG. 5 is a cross-sectional view of a heat exchanger according to a fifth alternative embodiment taken along line WW in FIG. [Figure 15] FIG. 13 is a diagram showing the use of an inspection tool according to a sixth embodiment.

[0032] Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. Note that the following description and the drawings merely show one embodiment of the present invention, and the contents of the present invention should not be interpreted as being limited to this embodiment.

[0033] (First aspect) (Air conditioner) An example of an air conditioner 1 is shown in FIG. 1. This air conditioner 1 has a housing 2 and, within the housing 2, a filter 3, a heat exchanger 4, and a fan 5, in that order from the windward side. In FIG. 1, the width direction of the housing 2 is X, the depth direction of the housing 2 is Y, and the up-down direction of the housing 2 is Z. The housing 2 has an outside air inlet 6 for letting in outside air and an outside air outlet 7, and the outside air flow AF is shown by arrows in FIG. 1. In other figures besides FIG. 1, the outside air flow is shown by white arrows AF. The outside air flow AF within the housing 2 flows in the Y direction in FIG. 1, although it is not shown by an arrow. Filter 3 works to increase the cleanliness of the outside air by removing pollutants contained in the outside air, such as dust, gas, and pollen, and the outside air that has passed through filter 3 is also good for the human body, making it possible to maintain the quality of the devices installed in air conditioner 1. Since filter 3 works to remove pollutants from the outside air, it is desirable for the outside air to pass through filter 3 before passing through other devices in the air conditioner, and filter 3 is often installed near outside air inlet 6 inside air conditioner 1. The material of filter 3 is generally polyester, modacrylic, etc., but is not limited to these, as the material to be used depends on the particle size of the pollutants to be removed. In order to create a flow of outside air AF, a fan 5 is installed near the outside air outlet of the air conditioner 1. This fan 5 draws outside air from inside the air conditioner 1 to outside the air conditioner 1. The size and number of units installed for each unit vary depending on the scale of the air conditioner 1. For example, air conditioners 1 used in laboratories and factories are large-scale, while air conditioners 1 used in homes are small-scale. Generally, when the wind speed of the outside air is 1 to 4 (m / s), and more preferably 2 to 3 (m / s), sufficient outside air can be taken in and heat can be exchanged efficiently. The air conditioner 1 of this embodiment includes an air conditioner, an outdoor air conditioner, etc., and may be anything that takes in outdoor air and exchanges heat. The air conditioner here is something that circulates outdoor air and indoor air, and the outdoor air conditioner is something that processes outdoor air. The present invention relates to a device that prevents rupture or destruction of a heat exchange coil 13 caused by freezing of water present in the heat exchanger 4 coil of an air conditioner or outdoor air conditioner, which is an air conditioning device 1, when the outside air temperature falls below freezing in cold regions in winter.

[0034] (heat exchanger) As shown in Figs. 2 and 3, the heat exchanger 4 is substantially rectangular and has a heat exchange coil 13 consisting of a straight pipe section 8 and a U-bend section 10, and a header section 12. Conventionally, the straight pipe section 8 is inserted into the fin section 14, and the U-bend section 10 protrudes outward from the fin 15 as shown in Fig. 3. As shown in Figs. 8 and 9, it is also possible to connect the straight pipe section 8 protruding outward from the fin 15 and the header section 12 with a header connection pipe 25. As shown in Figs. 1 and 2, the heat exchanger 4 in the air conditioner 1 is installed in the XZ plane with an interval between the outside air inlet surface 17 and the outside air outlet surface 18 of the heat exchange coil 13. The header section 12 has a first header 31 through which the circulating fluid flows into the heat exchange coil 13, and a second header 32 through which the circulating fluid flows out of the heat exchange coil 13. A circulating fluid flows within the heat exchanger 4, and as described above, this circulating fluid enters from the first header 31, passes through the header connecting pipe 25, flows through a continuous flow path formed by joining the straight pipes 9 and the U-bend pipes 11 in the straight pipe section 8 and the U-bend section 10, passes through the header connecting pipe 25, and exits from the second header 32. The circulating fluid is, for example, hot water or a refrigerant, but is not limited to these. The direction of the circulating fluid flowing through the flow path may be either from the top to the bottom or from the bottom to the top of the page in FIG. 2. In order to prevent the heat exchange coil 13 from freezing, water is drained from inside the coil, but after draining, water may remain in the lower part of the heat exchange coil 13 shown in FIG. 2. The lower part here refers to about the lower half to the lower third of the entire heat exchange coil 13 in the Z direction when the heat exchange coil 13 is provided with an outside air inlet surface 17 and an outside air outlet surface 18 on the XZ plane, that is, when the heat exchange coil 13 is installed so that the outside air inlet surface 17 and the outside air outlet surface 18 are perpendicular to the Y direction, which is the flow direction of the outside air. When water is drained from the header section 12, water is unlikely to remain, but when water is drained from the pipes connected to the outside from the header section 12, water tends to remain in the straight pipes 9 and the U-bend pipes 11 in the lower part of the heat exchange coil 13. When the outside air temperature falls below freezing, the water remaining in the pipes of the heat exchange coil 13 after draining is cooled by the outside air and freezes, expanding, causing the water pressure in the unfrozen parts of the pipes to increase and destroy the pipes.

[0035] (Fin part) The fin section 14 is formed by stacking a plurality of plate-like fins 15, and the outside air inlet surface 17 and the outside air outlet surface 18 are formed by connecting the edges of the stacked fins 15. As shown in FIG. 2, for example, the fins 15 are stacked to form a substantially rectangular parallelepiped as a whole, and the housing 16 of the heat exchanger 4 is present around the rectangular parallelepiped fin section 14. The heat exchanger 4 has an outside air inlet surface 17 through which the outside air enters and an outside air outlet surface 18 through which the outside air exits at a distance, and these two surfaces are perpendicular to the flow AF of the outside air passing through the fin section 14 and are positioned opposite each other. The size of the fin section 14 varies depending on the scale of the heat exchanger 4. In the present invention, the size of the fin section 14 varies depending on whether the straight pipe section 8 is covered with the fins 15 as in the first embodiment, or whether the entire U-bend section 10 and the straight pipe section 8 are covered with the fins 15 as in the second and third embodiments. Conventionally, in a heat exchange coil 13, as shown in Fig. 8, fins 15 are attached only to a straight pipe section 8, and heat exchange between the outside air and the circulating fluid is mainly performed in the straight pipe section 8. As shown in Fig. 4, one fin 15 has multiple mounting holes 19 through which a straight pipe 9 passes, and multiple fins 15 are stacked as shown in Figs. 2 and 3 so that the positions of the mounting holes 19 coincide with the direction perpendicular to the flow AF of the outside air and so that the outside air passes between the fins 15. The fins 15 are made of aluminum and therefore have good heat conductivity, but the material of the fins 15 is not limited to aluminum as long as it has good heat conductivity.

[0036] (straight pipe section) The straight pipe section 8 has a plurality of straight pipes 9 and forms a part of the heat exchange coil 13. As shown in FIG. 4, the long axis (diameter L) of the cross section of the straight pipes 9 is aligned along the direction of the outside air flow AF. The straight pipes 9 used in the heat exchange coil 13 are copper pipes that are easy to conduct heat, since the passing outside air is heated by the water in the heat exchange coil 13 and then taken in. However, they are not limited to copper pipes as long as they have high thermal conductivity. The straight pipes 9 may have a circular cross section, but an expandable shape such as an elliptical or oval shape is preferable. This is because, when the straight pipe section 8 having the straight pipes 9 with an elliptical cross section is used, even if the water remaining in the straight pipe section 8 after draining freezes and the portion that did not freeze expands due to water pressure, the cross section of the straight pipes 9 at that portion is deformed from an elliptical shape to a substantially circular shape, so that the straight pipe section 8 of the heat exchange coil 13 is more likely to be prevented from being destroyed. When using a straight tube 9 with an elliptical cross section, the long / short axis ratio of the ellipse is preferably 1:1.65 or more, and more preferably 1:2 or more. If the ratio is within this range, the straight tube 9 of the heat exchange coil 13 will not be damaged. The inner surface of the straight tube 9 may be provided with grooves to increase the surface area available for heat exchange and improve thermal conductivity. Although not shown, the end of the straight pipe 9 to which the U-bend pipe 11 is joined is widened, and the end of the U-bend pipe 11 is inserted and welded by brazing. The welding method is not limited to brazing, and for example, fusion welding, pressure welding, etc. may be used. 8, in the conventional heat exchange coil 13, fins 15 are attached only to the straight pipe section 8, and heat exchange between the outside air and the circulating fluid is mainly performed in the straight pipe section 8. Therefore, in an environment where the air temperature is below freezing, the temperature of the straight pipe section 8, in which the fins 15 are inserted, becomes lower than the temperature of the U-bend section 10, in which the fins 15 are not present, and the straight pipe section 8 freezes before the U-bend section 10.

[0037] (U-bend section) As shown in Figs. 3 and 8, in a conventional heat exchanger 4, the U-bend section 10 protrudes from the housing 16 of the heat exchanger 4. In an environment where the air temperature is below freezing, as described above, the temperature of the straight pipe section 8 in which the fins 15 are inserted becomes lower than the temperature of the U-bend section 10 in which the fins 15 are not present, and the straight pipe section 8 freezes before the U-bend section 10. As a result, there are some parts that freeze (mainly the straight pipe section 8) and some parts that do not freeze (mainly the U-bend section 10), and the tube of the heat exchange coil 13 is likely to break in the unfrozen parts (mainly the U-bend section 10). In most cases of freezing and breaking, the U-bend pipe 11 breaks. If the U-bend pipe 11 breaks, the problem arises that the heat exchanger 4 cannot be used until the problem is solved by repair or replacement.

[0038] (Heat exchange coil) The heat exchange coil 13 exchanges heat between the outside air taken into the air conditioner 1 and the circulating fluid flowing inside the heat exchange coil 13 by passing the outside air through the heat exchange coil 13, and the outside air after heat exchange flows into the room. Although not shown here, in winter, the low-temperature outside air exchanges heat with the warm circulating fluid, the warmed outside air flows into the room, and the cooled circulating fluid leaves the second header 32 of the header section 12 of the heat exchange coil 13, is compressed by a compressor, heated by a boiler, etc., and its temperature is increased, and it flows again into the heat exchange coil 13 from the first header 31 of the header section 12 as warm circulating fluid. The heat exchange coil 13 forms a continuous flow path with the straight pipe section 8 and the U-bend section 10. Both ends of multiple adjacent straight pipes 9 are joined with U-bend pipes 11, and the heat exchange coil 13 consisting of the straight pipe sections 8, the U-bend section 10, and the header section 12 forms a continuous flow path. As shown in Figures 9 and 10, it is also possible to join the end of the straight pipe 9 to which the U-bend pipe 11 of the straight pipe section 8 is not joined and the header section 12 via a header connecting pipe 25. For example, in Figs. 2, 5, 8 and 9, the ends of four straight pipes 9 are joined by three U-bend pipes 11, and the ends of the straight pipes 9 to which the U-bend pipes 11 are not joined are joined to the header section 12 via the header connection pipe 25. The header section 12 is composed of a first header 31 and a second header 32. The flow paths composed of the four straight pipes 9 and the three U-bend pipes 11 overlap each other from the top to the bottom of Fig. 2 to form a continuous flow path. In other words, a plurality of flow paths composed of the four straight pipes 9 and the three U-bend pipes 11 are provided in the vertical direction to form a flow path group, and one end of each flow path is joined to the header connection pipe 25 and the first header 31, respectively, and the other end is joined to the header connection pipe 25 and the second header 32, respectively. Although not shown, pipes for introducing or discharging the circulating fluid are connected to the outside of the first header 31 and the second header 32. In this embodiment, the circulating fluid from the header 12 can be distributed to each flow path consisting of four straight pipes 9 and three U-bend pipes 11 overlapping from the top to the bottom of the heat exchanger 4, making it easier to perform heat exchange uniformly from the top to the bottom of the flow path. Also, in this embodiment, the heat exchange coil 13 is not only continuous in the vertical direction but also has a thickness in the YZ directions, making it easier to perform heat exchange efficiently all at once. The continuous flow path is not limited to the illustrated form, and may be a flow path formed only of straight pipes 9 and U-bend pipes 11 that are continuous only in the vertical direction and have no thickness in the YZ direction. In addition, all straight pipes 9 in this form may be connected by U-bend pipes 11, and only one end of the straight pipes 9 in the uppermost and lowermost stages of the heat exchange coil 13 may not be connected to the U-bend pipes 11 and may be a long continuous flow path connected to the header section 12 via the header connecting pipe 25. In this long flow path that is continuous from the uppermost stage to the lowermost stage of the heat exchange coil 13, there is one joint between the straight pipe section 8 and the first header 31 via the header connecting pipe 25, and one joint between the straight pipe section 8 and the second header 32 via the header connecting pipe 25. Therefore, the efficiency of heat exchange is improved compared to the forms of Figures 2, 5, and 8, etc., and the circulating liquid tends to flow smoothly to the end of the continuous flow path. The straight pipes 9 of the straight pipe section 8 may have a circular cross section or an elliptical, oval, or other shape that can expand under internal pressure. When a straight pipe section 8 having an expandable cross section is used, as shown in FIG. 4, the short axis S of the ellipse is perpendicular to the outside air flow AF and the long axis L of the ellipse is parallel to the outside air flow AF. Therefore, compared to when a circular straight pipe 9 is used, the outside air does not separate after passing through the straight pipe 9, which tends to reduce air resistance and facilitates more efficient heat exchange.

[0039] (Partition plate) The inside of the air conditioner 1 is divided by a partition plate 20 into a first chamber 21 into which the outside air flows and a second chamber 22 into which the outside air heated after heat exchange is discharged. As shown in FIG. 5, the partition plate 20 generally installed in the air conditioner 1 or the outdoor air conditioner is located on the upstream side of the passage of the outside air relative to the heat exchanger 4, and as shown in FIG. 7, an opening 23 is provided that is slightly smaller than the size of the surface on which the fins 15 are arranged so that the outside air passes through the straight pipe section 8 into which the fins 15 are inserted. As shown in FIGS. 5 to 7, the partition plate 20 located on a surface perpendicular to the flow AF of the outside air is installed so that the edge of the opening 23 of the partition plate 20 is in close contact with the peripheral part 29 of the outside air inlet surface 17 of the heat exchanger 4 or the peripheral part 29 of the outside air outlet surface 18 facing it via a packing 24 or the like so that the outside air passes only through the fin section 14 and the straight pipe section 8 of the heat exchanger 4. This is to reliably guide the outside air to flow into the fin section 14 and the straight pipe section 8, and to prevent the outside air from leaking to other sections. In order to install the partition plate 20 in close contact with the heat exchanger 4, not only the packing 24 but also an elastic member having appropriate elasticity or an adhesive may be used.

[0040] In winter, the cause of freeze damage to the heat exchange coil 13 is that there is a temperature difference between the straight pipe section 8 and the U-bend section 10, which means that there are some parts that freeze (mainly the straight pipe section 8) and some parts that do not (mainly the U-bend section 10). As a result, the water pressure of the residual water rises in the unfrozen parts (mainly the U-bend section 10), making the pipes of the heat exchange coil 13 more likely to break. The applicant has confirmed through experiments that the heat exchange coil 13 does not break in the frozen parts, but freeze damage occurs in the unfrozen parts, because the water pressure in the unfrozen parts is higher than the pressure rise in the frozen parts. For this reason, the applicant thought that if the structure is designed to eliminate the temperature difference between the straight pipe section 8 and the U-bend section 10 and to prevent the creation of unfrozen parts, there will be no unfrozen parts, making freeze damage less likely to occur.

[0041] In the case of the positional relationship between the conventional partition plate 20 and the heat exchanger 4 shown in FIG. 5, the opening 23 of the partition plate 20 creates a temperature difference between the straight pipe section 8 located on the path of ventilation and the U-bend section 10 blocked from ventilation by the partition plate 20, so the straight pipe section 8 is likely to freeze before the U-bend section 10. When the straight pipe section 8 freezes and the U-bend section 10 is left unfrozen, the pipe is likely to break. For this reason, if a structure is used that cools the entire heat exchange coil 13 and the entire pipe freezes at the same time, pressure does not increase at a specific location and breakage is unlikely to occur. The first embodiment corresponds to this structure. It is easy to manufacture because it only requires changing the position of the conventional partition plate 20. In the first embodiment, as shown in FIG. 6, the partition plate 20 is installed downstream of the passage of outside air relative to the heat exchanger 4, so that the heat exchanger 4, which was conventionally located in the second chamber 22, is now located in the first chamber 21, and not only the straight pipe section 8 of the heat exchanger 4 coil but also the U-bend section 10 is exposed to the outside air. The outside air passes through the U-bend section 10, which was conventionally blocked by the partition plate 20 and did not allow the outside air to pass through, and the straight pipe section 8 and the U-bend section 10 of the heat exchanger 4 coil are uniformly cooled and frozen uniformly. In other words, when the outside air falls below freezing point, the temperature of both the straight pipe section 8 and the U-bend section 10 drops, and the remaining water in the pipes is frozen. For this reason, it is highly likely to prevent the phenomenon that has occurred in the past, in which the straight pipe section 8 is cooled before the U-bend section 10, the water in the straight pipe section 8 freezes and expands, the pressure of the unfrozen remaining water in the U-bend section 10 increases, and the U-bend section 10 is destroyed.

[0042] (Second Aspect) The second embodiment corresponds to a different structure in which the entire heat exchange coil 13 is cooled so that the entire tube freezes at the same time. As shown in Figure 10, fins 15 are attached not only to the straight tube section 8 but also to the U-bend section 10, and the entire heat exchange coil 13 is inserted into the fins 15. Comparing the first embodiment with the second embodiment, the heat exchange coil 13 is the same device. The position of the partition plate 20 is different, and may be the same as the partition plate 20 of the conventional air conditioner 1, but is not limited to this, and may be a different position. For example, it may be disposed on the outside air inlet surface 17 side of the heat exchanger 4, or on the outside air outlet surface 18 side of the heat exchanger 4. Since the number of stacked fins 15 is greater than in the first embodiment, the size of the fin portion 14 is larger, and the heat exchanger 4 is also different from that in the first embodiment. In the second embodiment, the straight pipe section 8 and the U bend section 10 are used as a heat exchange section between the outside air and water by providing aluminum fins 15 up to the U bend section 10 of the heat exchange coil 13. As shown in FIG. 10, the straight pipe section 8 and the U bend section 10 are included in the fin section 14. In this embodiment, the straight pipe section 8 and the U bend section 10 of the heat exchange coil 13 into which the fins 15 are inserted drop in temperature at the same time, and the straight pipe section 8 and the U bend section 10 can be frozen at the same time, so that a pressure rise at a specific location is unlikely to occur and the coil is unlikely to break. The straight pipe section 8 and the U bend section 10 are close in temperature, and they freeze at the same time, making it easier to prevent water confinement, so that a water pressure rise is unlikely to occur and pipe breakage is unlikely to be prevented.

[0043] (Third Aspect) The third embodiment combines the features of the first and second embodiments, and a cross-sectional view of the air conditioner 1 is shown in FIG. 11. The heat exchange coil 13 of the first, second, and third embodiments is the same device. The first embodiment and the third embodiment have the same position of the partition plate 20. In the third embodiment, similar to the first embodiment, outside air passes through the straight pipe section 8 and the U-bend section 10 of the heat exchange coil 13 after passing through the opening 23 of the partition plate 20. The second embodiment and the third embodiment have the same heat exchanger 4, since the number of layers of the fins 15 in the heat exchanger 4 is increased. In the third embodiment, as shown in Figures 10 and 11, the straight pipe section 8 and the U-bend section 10 are included in the fin section 14. As can be seen from Figure 11, outside air passes through the entire heat exchange coil 13 in the heat exchanger 4, and fins 15 are inserted into the straight pipe section 8 and the U-bend section 10, which makes it easier to freeze the straight pipe section 8 and the U-bend section 10 simultaneously more reliably, prevents residual water from being trapped, makes it less likely that water pressure will increase, and makes it even more difficult to prevent pipe damage.

[0044] (Fourth aspect) The fourth embodiment combines the features of the first and second embodiments and is different from the third embodiment. A cross-sectional view of the air conditioner 1 is shown in FIG. 11. The heat exchange coils 13 of the first, second, third, and fourth embodiments are the same device. The first embodiment and the fourth embodiment have the same position of the partition plate 20. In the fourth embodiment, similar to the first embodiment, the outside air passes through the straight pipe section 8 and the U-bend section 10 of the heat exchange coil 13 after passing through the opening 23 of the partition plate 20. The second and third embodiments have the same heat exchanger 4 as the fourth embodiment, since the number of layers of the fins 15 in the heat exchanger 4 is increased. In the fourth embodiment, as shown in Figures 10 and 12, the straight pipe section 8 and the U-bend section 10 are included in the fin section 14. As can be seen from Figure 12, the outside air that has entered the first chamber 21 passes through the opening 23 of the partition plate 20 and exits toward the second chamber 22, so that the outside air is concentrated on the fin section 14 of the heat exchange coil 13 in the heat exchanger 4 and reliably passes through. Furthermore, since the fins 15 are inserted into the straight pipe section 8 and the U-bend section 10, it becomes easier to freeze the straight pipe section 8 and the U-bend section 10 simultaneously more reliably, it is possible to prevent the trapping of residual water, it becomes less likely that water pressure will increase, and it becomes even more difficult to prevent the pipes from breaking.

[0045] (Fifth aspect) The applicant confirmed through experiments that when water is sealed in the straight pipe 9 and the U-bend pipe 11 with one end open and frozen uniformly, the water overflows from the open end of the straight pipe 9 and the coil is not destroyed by freezing. This shows that if there is a place for the pressure of the trapped water to escape, the heat exchange coil 13 is unlikely to be destroyed even if the water pressure of the remaining water increases. In the fifth embodiment, in order to provide a place for the water pressure to escape, the cross-sectional shape of the tube of the U-bend portion 10 or the header portion 12 of the heat exchange coil 13 in the first or second embodiment is an ellipse, an oval, or the like, whose internal volume is expanded. As an example, in FIG. 13, the cross-sectional shape of the tube of the header portion 12 of the heat exchange coil 13 in the first embodiment is an ellipse, an oval, or the like, whose internal volume is expanded. In FIG. 14, the cross-sectional shape of the tube of the header portion 12 of the heat exchange coil 13 in the second embodiment is an ellipse, an oval, or the like, whose internal volume is expanded. As a result of an increase in the water pressure of the U-bend portion 10 or the header portion 12, for example, the elliptical U-bend portion 10 or the header portion 12 becomes approximately circular, and the pressure escapes to the expanded place, making it easier to avoid destruction. The cross-sectional shape of the tube of the heat exchange coil 13 may be deformed to increase the volume, and is not limited to an ellipse or an oval. Shapes close to disks, such as ovals and ovals, are flattened shapes, so when internal pressure is applied, they expand into a roughly circular shape, and a force is applied in the direction of increasing the cross-sectional area. Since the destruction of the tubes of the heat exchange coil 13 in the unfrozen portion is due to the increase in pressure of the water that remains unfrozen, in order to alleviate this pressure increase, it is preferable that at least one of the unfrozen portions, the U-bend portion 10 or the header portion 12, has a shape that increases the possibility of releasing the increased pressure. It is more preferable to use tubes with both the U-bend portion 10 and the header portion 12 that are deformable shapes, as this provides more places for pressure to escape than when only one of the tubes is deformable.

[0046] (Sixth aspect) As a method for checking for deformation of the tube of the heat exchange coil 13 due to an increase in water pressure, a tool 26 as shown in Fig. 15 can be used. This tool 26 may be any tool that has a handle 27 and a checking section 28 that has a space slightly larger than or approximately the same size as the diameter of the tube of the heat exchange coil 13 for checking the diameter of the tube of the heat exchange coil 13. For example, a wrench falls under this category, but it is not limited to a wrench as long as it is capable of checking for deformation of the tube of the heat exchange coil 13. For example, in the case where a straight pipe 9 having an elliptical cross section is used in the heat exchange coil 13, when an instrument 26 having a space slightly larger than or approximately the same length as the minor axis S of the ellipse as shown in Fig. 15(b) is inserted into the straight pipe 9 as shown in Fig. 15(a), if the minor axis S of the straight pipe 9 does not fit within the space of the instrument 26 as shown in Fig. 15(c), it is understood that the straight pipe 9 has expanded due to water pressure. Although not shown, when an instrument 26 having a space slightly larger than the major axis L of the ellipse is inserted into the straight pipe 9, if the space between the instrument 26 and the straight pipe 9 becomes wider, it is understood that the straight pipe 9 has expanded due to water pressure. Here, a method for checking the diameter of the straight pipe 9 of the heat exchange coil 13 has been described, but the method is not limited to the straight pipe 9. When a U-bend pipe 11 having an elliptical cross section is used, the same method may be used to check the deformation of the U-bend pipe 11. When a header portion 12 having an elliptical cross section is used, the same method may also be used to check the deformation of the header portion 12. Once the cross section of the tube of the heat exchange coil 13 has expanded and deformed due to water pressure, it will never return to its original oval shape, so if the water pressure rises again as a result of the residual water freezing, and the deformed tube cannot withstand this rise, the heat exchange coil 13 will be destroyed. For this reason, before the heat exchange coil 13 is destroyed, an inspection can be performed using the device 26, and the timing for replacing the heat exchange coil 13 can be ascertained, allowing action to be taken before the air conditioner 1 breaks down. [Industrial Applicability]

[0047] The present invention is suitable for preventing freeze damage in heat exchange coils of heat exchangers provided in air conditioners and outdoor air conditioners in winter, as in the above-mentioned examples. [Explanation of symbols]

[0048] Reference Signs List 1...air conditioner, 2...air conditioner housing, 3...filter, 4...heat exchanger, 5...fan, 6...outdoor air inlet, 7...outdoor air outlet, 8...straight pipe section, 9...straight pipe, 10...U-bend section, 11...U-bend pipe, 12...header section, 13...heat exchange coil, 14...fin section, 15...fin, 16...heat exchanger housing, 17...outdoor air inlet surface, 18...outdoor air outlet surface, 19...mounting hole, 20...partition plate, 21...first chamber, 22...second chamber, 23...opening, 24...packing, 25...header connection pipe, 26...apparatus, 27...handle, 28...check section, 29...periphery, 31...first header, 32...second header, S...minor diameter, L...major diameter

Claims

1. The device has a housing, the housing includes a first chamber, a second chamber, and a partition plate having an opening that separates the first chamber from the second chamber; A heat exchanger is installed in the first chamber, The heat exchanger has a fin portion formed by stacking a plurality of fins and a heat exchange coil, and exchanges heat between outside air and a circulating fluid flowing through the heat exchange coil, The heat exchange coil has a continuous flow path formed by a straight pipe section made of a plurality of straight pipes and a U-bend section made of a plurality of U-bend pipes, both ends of the heat exchange coil are joined to a header section, the straight pipe section is provided penetrating through the fin section, and the U-bend section protrudes outward from the fin section, The straight pipe portion has a cross section that can expand under internal pressure, Outside air enters the first chamber, passes through the fin portion, enters the second chamber through the opening, and exits the second chamber, The periphery of the surface of the fin portion on the outside air outlet side is closed by the edge of the opening. An air conditioning device characterized by:

2. The device has a housing, A heat exchanger is installed in the housing, The heat exchanger has a fin portion formed by stacking a plurality of fins and a heat exchange coil, and exchanges heat between outside air and a circulating fluid flowing through the heat exchange coil, The heat exchange coil has a continuous flow path formed by a straight pipe section made of a plurality of straight pipes and a U-bend section made of a plurality of U-bend pipes, both ends of the heat exchange coil are joined to a header section, and the entire U-bend section and the straight pipe section are provided within the fin section, Both ends of the heat exchange coil are joined to the header portion, The straight pipe portion has a cross section that is expandable under internal pressure. An air conditioning device characterized by:

3. the housing includes a first chamber, a second chamber, and a partition plate having an opening that separates the first chamber from the second chamber; The heat exchanger is disposed in the first chamber, Outside air enters the first chamber, passes through the fin portion, enters the second chamber through the opening of the partition plate, and exits the second chamber, 3. The air conditioner according to claim 2, wherein a peripheral portion of a surface of said fin portion on the side of the outside air outlet is closed by an edge of said opening.

4. the housing includes a first chamber, a second chamber, and a partition plate having an opening that separates the first chamber from the second chamber; The heat exchanger is disposed in the second chamber, Outside air enters the first chamber, enters the second chamber through the opening of the partition plate, passes through the fin portion, and exits the second chamber, 3. The air conditioner according to claim 2, wherein a peripheral portion of a surface of said fin portion on the outside air inlet side is closed by an edge of said opening.

5. 3. An air conditioner according to claim 1, wherein a cross section of at least one of said pipes in said U-bend section and said header section has a shape capable of expanding when subjected to internal pressure.

Images