JP2014180608A - Method of manufacturing cooler and heat exchanger of compressed air dehumidifier - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of manufacturing a cooler contained in a heat exchanger of a compressed air dehumidifier, with which it is possible to reduce time required for manufacturing and reduce cost.SOLUTION: In a heat exchanger 1 that includes a cooler 2 contained in a pressure vessel 20 provided with a compressed-air inlet port 21 and a compressed-air discharge port 22, and that exchanges heat with compressed air as an evaporator in a refrigeration cycle 30 to cool and dehumidify the compressed air, and that is configured to be able to discharge drain generated in the cooler 2 at a time of cooling the compressed air to outside of the vessel 20, the cooler 2 comprises a plurality of cooler blocks 2 each including: heat exchange fins 10; a meander refrigerant pipe 11 penetrating these heat exchange fins 10; and side plates 13 provided on both ends of each of the heat exchange fins 10, respectively, and common pipe plates 14 and 15 hold both ends of the cooler blocks 2, respectively.

Description

  The present invention relates to a method of manufacturing a cooler housed in a heat exchanger of a compressed air dehumidifier that dehumidifies by cooling compressed air by a refrigeration cycle.

  There is a compressed air dehumidifying apparatus (hereinafter referred to as “dehumidifying apparatus”) that dehumidifies by cooling compressed air by a refrigeration cycle. In this dehumidifier, the compressed air is cooled by exchanging heat with the refrigerant in the heat exchanger, the moisture contained in the compressed air is condensed, and dehumidified by separating and discharging the condensed moisture (hereinafter, compressed air). The separated water is called "drain").

A portion of the heat exchanger that is cooled by the refrigerant (hereinafter referred to as “cooler”) is a fin-and-tube type that includes a plurality of heat exchange fins and a refrigerant pipe that penetrates the heat exchange fins. A cooler is used. Conventionally, this type of cooler includes a plurality of heat exchange fins arranged at predetermined intervals, and a tube plate for fixing a refrigerant pipe that is provided at both ends of the heat exchange fins and is thicker and stronger than the heat exchange fins. And meandering refrigerant pipes that pass through the heat exchange fins and the tube sheet. When this cooler is manufactured, a through hole larger than the outer diameter of the refrigerant pipe is formed in the heat exchange fin and the tube plates at both ends of the heat exchange fin, and a plurality of straight main pipes are formed in the through hole. Is inserted. In this state, an expansion jig is inserted into the main pipe, and the main pipe is expanded from the inside by expanding. Thereby, the outer surface of the main pipe is brought into close contact with the through hole, and the main pipe, the heat exchange fin and the tube plate are fixed.
Next, the end portion of the bend pipe curved in a U-shape is inserted into the end portion of the straight tubular main pipe, and both are fixed by welding with a brazing material (welding material), whereby a meandering refrigerant pipe The fin and tube type cooler was assembled.

  However, in the manufacture by the pipe expansion as described above, there is a limit to the size of the cooler that can be expanded by the pipe expansion jig, and the cooler used in the large dehumidifier cannot be expanded by the pipe expansion jig. Therefore, when manufacturing a large cooler, a pipe expansion method using water pressure is employed. Before expanding the pipe, the main pipe and the bend pipe are fixed by welding with a brazing material, and water is filled in a meandering refrigerant pipe made into a closed circuit to apply pressure, and the main pipe is expanded by water pressure from the inside. To do. As a result, the outer surface of the main pipe is brought into close contact with and in contact with the through hole in the same manner as in the pipe expansion method using the pipe expansion jig, and the main pipe, the heat exchange fin, and the tube plate are fixed.

  In the cooler, the main pipe and the bend pipe, which are copper materials that compose the refrigerant pipe of the cooler, are corroded by the compressed gas mixed with the corrosive gas of the surrounding environment and the drain containing the corrosive substance. May leak. The reason why there are more leaks due to corrosion in the cooler than other parts of the dehumidifying device is that the corrosive substance is compressed and concentrated from the atmosphere, and the corrosive substance is concentrated by drain (condensed water). It is thought that corrosion is promoted by having been in the state.

  When installing a dehumidifier in a place where corrosive gas is already known in the surrounding environment, such as a chemical factory, to prevent the refrigerant piping of the cooler from corroding, the material of the main piping and bend piping should be made of copper. It has been changed to stainless steel to improve corrosion resistance and prevent corrosion.

JP 2000-18882 A

  However, the heat exchanger of the conventional dehumidifier has the following problems to be improved.

  In the case of manufacturing a large cooler, pipe expansion by a water pressure is performed because pipe expansion by a pipe expansion jig cannot be performed as described above. When the refrigerant pipe of the cooler is made of stainless steel, the stainless steel is harder than copper, so the water pressure required to expand the pipe must be increased. The yield was difficult. In addition, the expansion by water pressure cannot be expanded uniformly, and the adhesion between the main piping and the heat exchange fins varies, which may affect the heat exchange performance of the cooler. Furthermore, the main pipe may swell due to the expansion of the water pressure, and the heat exchange fins may be expanded to distort the shape of the cooler. Therefore, after setting the frame-shaped jig to constrain the cooler after pipe expansion to the intended shape, pipe expansion is performed by water pressure, but it took time to set the frame-type jig. . Furthermore, after pipe expansion by water pressure, water remains in the refrigerant piping of the cooler, so that time and cost required for drying in the piping are required.

  The present invention has been made in view of the problems to be improved, and in the case of manufacturing a large-sized cooler using a stainless steel refrigerant pipe, the yield is good and the time required for manufacturing is shortened to reduce the cost. It is a main object of the present invention to provide a heat exchanger for a dehumidifying device.

  In order to achieve the above object, the heat exchanger of the compressed air dehumidifying device according to claim 1 is a cooler that cools and dehumidifies by exchanging heat with compressed air as an evaporator of a refrigeration cycle, and the cooler includes a plurality of coolers. It comprises a plurality of cooler blocks composed of heat exchange fins, meandering refrigerant pipes passing through the heat exchange fins, and side plates provided at both ends of the heat exchange fins. It is formed by inserting an expansion jig to fix the heat exchange fin, the refrigerant pipe, and the side plate, and holding both ends of the plurality of cooler blocks with a common tube plate, respectively. .

  The heat exchanger of the compressed air dehumidifying device according to claim 2, wherein the cooler is accommodated in a pressure vessel having an inlet and an outlet for compressed air, and the pressure vessel is cooled when the compressed air is cooled. The drain generated by the cooler is configured to be discharged to the outside of the pressure vessel.

  According to the method for manufacturing a cooler according to claim 1, since the cooler is divided into a plurality of cooler blocks and is expanded by a tube expansion jig, the time required for manufacturing is shortened compared to expansion by water pressure. This can eliminate the burst of the refrigerant pipe and improve the yield. Moreover, since the main pipe is uniformly expanded, the main pipe and the heat exchange fins are in close contact with each other, so that variations in the heat exchange performance of the cooler can be eliminated. Furthermore, since it is not necessary to use a frame-shaped jig that was necessary for the expansion by water pressure, the time required for setting the frame-shaped jig can be reduced. Moreover, since water is not used, it is not necessary to dry the inside of the pipe, and the time and cost required for drying can be reduced. Moreover, since each cooler block is hold | maintained by the common tube board, a some cooler block can be hold | maintained integrally and it can be set as one cooler.

  Moreover, according to the heat exchanger of the compressed air dehumidification apparatus of Claim 2, it can be set as the heat exchanger of a compressed air dehumidification apparatus by accommodating a cooler in a pressure vessel.

It is a figure which shows the outline | summary of the heat exchange apparatus of the compressed air dehumidification apparatus of this invention. It is a figure which shows the structure of the cooler of this invention. It is an exploded view which shows the structure of the cooler of this invention.

  Hereinafter, an embodiment of a heat exchange device of a compressed air dehumidifier according to the present invention will be described with reference to the drawings.

  First, the configuration of a compressed air dehumidifying device and a heat exchange device will be described with reference to the drawings.

  The compressed air dehumidifying device 3 (hereinafter also referred to as “dehumidifying device 3”) shown in FIG. 1 is an example of a heat exchange device of the compressed air dehumidifying device of the present invention, and includes a refrigeration cycle 30, a compressed air inlet 21 and A pressure vessel 20 having a discharge port 22 and a drain port 27 is provided with a heat exchanger 1 and a drain discharger 28 in which a cooler 2 as an evaporator of a refrigeration cycle 30 is housed.

  The refrigeration cycle 30 includes a cooler 2 that functions as an evaporator, a compressor 31, a condenser 32, and an expansion valve 33. The cooler 2 is disposed in the secondary cooling unit 24 of the heat exchanger 1 and the refrigerant discharged from the expansion valve 33 is vaporized, whereby the surrounding compressed air (compressed air in the secondary cooling unit 24) is removed. Cooling. The compressor 31 pumps the refrigerant whose temperature has been increased by heat exchange with the compressed air in the cooler 2 toward the condenser 32. A fan 34 is attached to the condenser 32, and the high-temperature and high-pressure refrigerant pumped by the compressor 31 is cooled and condensed.

  The actual refrigeration cycle 30 includes a bypass pipe for returning a part of the refrigerant pumped by the compressor 31 between the cooler 2 and the compressor 31 or between the expansion valve 33 and the cooler 2. Although a capacity control valve is provided, the description and illustration thereof are omitted to facilitate understanding of the present invention.

  Next, the configuration of the heat exchanger 1 will be described.

  The heat exchanger 1 is composed of a pressure vessel 20 that is cylindrical as a whole and extends in the direction of the cylindrical axis, and has a cylindrical secondary cooling that communicates with the primary cooling unit 23 by a partition wall mounted in the pressure vessel 20. A front chamber 25 and a rear chamber 26 are provided across the portion 24. The front chamber 25 and the rear chamber 26 are connected to each other by a connecting pipe 29. In this case, the primary cooling unit 23 is provided with an introduction port 21 for introducing the compressed air to be processed, and is compressed through the connecting pipe 29 from the front chamber 25 toward the rear chamber 26 as described later. A primary cooling unit 23 that cools the compressed air introduced from the inlet 21 by air and a cooler 2 that functions as an evaporator of the refrigeration cycle 30 are housed to cool the compressed air discharged from the primary cooling unit 23. A secondary cooling unit 24 for discharging to the front chamber 25 is provided.

  The front chamber 25 is provided with a drain port 27 for draining water (drain) removed from the compressed air. The drain port 27 is provided at the bottom of the heat exchanger 1 and a drain discharger 28 for discharging the drain is attached. Further, the rear chamber 26 is provided with a discharge port 22 for discharging the compressed air after the dehumidifying treatment.

  The secondary cooler 24 shown in FIG. 1 houses the cooler 2 shown in FIG. Next, a detailed configuration of the cooler 2 and a manufacturing method will be described with reference to FIGS. FIG. 2 shows the overall configuration of the cooler 2, and FIG. 3 shows the configuration of the cooler 2 to which two cooler blocks 3 are integrally attached. Description is omitted.

  2 and 3, the cooler 2 includes two cooler blocks 3, tube plates 14 and 15 that hold the two cooler blocks from both sides, a plurality of partition plates 16, and two cooler blocks. 1 is connected to the respective refrigerant inlet openings 11b and the respective refrigerant outlet openings 11c of the three refrigerant pipes 11.

  The cooler block 3 includes a plurality of aluminum thin plate heat exchange fins 10 provided at predetermined intervals, and a pair of heat exchanger fins 10 that are disposed at both ends of the heat exchange fins 10 and are thicker and stronger than the heat exchange fins 10. The side plates 13a and 13b, and the so-called fin-and-tube type heat exchanger composed of the heat exchange fins 10 and the meandering stainless steel pipe refrigerant pipes 11 penetrating the side plates 13a and 13b.

  The meandering refrigerant pipe 11 constituting the cooler block 3 is heat-exchanged from the side pipe 13a with the main pipe 11a formed in a U shape by curving the longitudinal center of a plurality of straight pipes. It is comprised from the bend piping 12 which exhibited the U shape which connects the edge part of the main piping 11a located in the separation | spacing side of the fin 10 mutually. Specifically, the main pipe 11a of the present embodiment has a U-shaped curved portion located on the side of the heat exchange fin 10 away from the side plate 13b and between the side plates 13a and 13b. Reference numeral 10 denotes a linear portion having a linear shape.

  The manufacturing method of the cooler block 3 having the above configuration will be described. First, as shown in FIG. 3, a plurality of heat exchange fins 10 provided at predetermined intervals, and side plates 13 a provided on both sides of the heat exchange fins 10. 13b, a through hole slightly larger than the outer diameter of the main pipe 11a of the refrigerant pipe 11 is formed. Next, both ends of the main pipe 11a are inserted from the through holes formed in the side plate 13b, and the through holes and side plates formed in the heat exchange fins 10 arranged at a predetermined interval from the side plate 13b to the other side plate 13a. The main pipe 11a is sequentially inserted into the through hole 13a. At this time, both ends of the main pipe 11a are located on the side away from the heat exchange fin 10 with respect to the side plate 13a.

  In this state, an extension jig (not shown) is inserted from the openings at both ends of the main pipe 11a. Specifically, the expansion rod having an outer diameter slightly larger than the inner diameter of the main pipe 11a is aligned with the openings at both ends of the main pipe 11a. In this state, the expansion rod is inserted into the main pipe 11a. As a result, the main pipe 11a is expanded by being expanded from the inside by the expansion rod inserted into the main pipe 11a (expansion), and the outer peripheral surface of the main pipe 11a is connected to the heat exchange fin 10 and the side plates 13a and 13b. The main pipe 11a and the heat exchange fin 10, and the main pipe 11a and both side plates 13a and 13b are brought into close contact with the formed through hole.

  Thereafter, the extension rod of the extension jig is pulled out from the main pipe 11a, and the end of the bend pipe 12 curved in a U-shape is inserted into the opening of the end of the main pipe 11a, and the brazing material (welding material) is used. By fixing both by welding, a meandering refrigerant pipe 11 is formed. Thereby, the fin-and-tube heat exchanger (cooler block 3) is assembled.

  Next, the manufacturing method of the cooler 2 will be described with reference to FIG.

  As shown in the figure, two identical cooler blocks 3, 3 are brought into contact with the end portions of the side plates 13a, 13a of the cooler blocks 3, 3 and the end portions of the side plates 13b, 13b. Overlapping. The cylindrical secondary cooling portion 24 has a circular end portion 14a having substantially the same diameter as the cylinder, and the lower portion and the circular central portion of the circular end portion 14a are the cooler block 3. The tube plate 14 having an opening 14b that is open so as not to contact the main pipe 11a and the bend pipe 12 is arranged so that the tube plate 14 and the side plates 13a and 13a of the cooler blocks 3 and 3 partially overlap each other. To place. In this state, a screw (not shown) is inserted into the mounting hole 14d provided at the place where the tube plate 14 and the side plates 13a and 13a overlap each other, and both are fastened.

  Further, it has a circular end 15a having the same diameter as the circular end 14a of the tube sheet 14, an opening 15b in the lower portion of the circular end 15a, and the cooler block 3 The tube plate 15 having a plurality of openings 15c is arranged so as not to contact the main pipe 11a so that the tube plate 15 and the side plates 13b and 13b of the cooler blocks 3 and 3 partially overlap each other. In this state, a screw (not shown) is inserted into the mounting hole 15d provided at the place where the tube plate 15 and the side plates 13b and 13b overlap each other, and both are fastened.

  As shown in FIG. 2, a plurality of partition plates 16 are inserted between the heat exchange fins 10 and 10 of the cooler blocks 3 and 3 so as to form a meandering flow path of compressed air in the secondary cooling unit 24. And fix. Then, the refrigerant inlet openings 11b of the refrigerant pipes 11 and 11 of the respective cooler blocks 3 and 3 are connected to each other by welding the header pipe 17 with a brazing material, and the refrigerant pipes 11 of the respective cooler blocks 3 and 3 are connected. , 11 are also connected to each other by welding the header pipe 17 with a brazing material. Thereby, the cooler 2 is formed by making each refrigerant | coolant piping 11 and 11 of the two cooler blocks 3 and 3 into one refrigerant flow path.

  The cooler 2 is housed in the secondary cooling unit 24 of the pressure vessel 20 and functions as an evaporator of the refrigeration cycle 30 by connecting a refrigerant pipe of the refrigeration cycle 30.

  Subsequently, the dehumidifying process of the compressed air by the dehumidifying device 3 and the heat exchanger 1 will be specifically described with reference to the drawings.

  First, the compressor 31 is operated to circulate the refrigerant in the refrigeration cycle 30. At this time, as will be described later, the inside of the secondary cooling unit 24 is cooled by vaporization of the refrigerant in the cooler 2. The compressed air is introduced from the inlet 21 into the heat exchanger 1 (primary cooling unit 23). In this case, the compressed air introduced into the heat exchanger 1 is heated to a high temperature when compressed by an air compressor (not shown). This high-temperature compressed air is cooled in the dehumidifying process described later, and heat exchange is performed in the primary cooling unit 23 with the compressed air after the dehumidifying treatment that is passed through the connecting pipe 29 from the front chamber 25 toward the rear chamber 26. Cooled (cooled by compressed air after dehumidification). As a result, a part of the moisture contained in the compressed air introduced from the inlet 21 is condensed around the connecting pipe 29 in the primary cooling unit 23 and removed from the compressed air.

  The compressed air primarily cooled in the primary cooling unit 23 is formed in a cylindrical shape extending from the primary cooling unit 23 in the same direction as the cylindrical axis of the pressure vessel 20, and the secondary cooling unit 24 in which the cooler 2 is accommodated. And is sufficiently cooled by the cooler 2 of the refrigeration cycle 30 in the secondary cooling unit 24. At this time, the compressed air introduced into the secondary cooling unit 24 includes the tube plate 14 and its opening 14b, the tube plate 15 and its opening 15b, and a plurality of partition plates 16 constituting the cooler 2. As a result, as shown by the arrow in FIG. 1, the cooling is efficiently performed while meandering and moving in the secondary cooling section 24. At this time, almost all of the moisture contained in the compressed air discharged from the primary cooling unit 23 is condensed around the cooler 2 in the secondary cooling unit 24 and removed from the compressed air. To be dehumidified. Further, the water removed from the compressed air in both the cooling units 23 and 24 is discharged from the drain 27 at the bottom of the heat exchanger 1 to the outside of the heat exchanger 1 through the drain discharger 28. On the other hand, when the low-temperature and low-humidity compressed air that has been cooled and dehumidified in both the cooling units 23 and 24 is discharged from the secondary cooling unit 24 to the front chamber 25 and then passed through the connecting pipe 29 in the primary cooling unit 23. Then, the temperature is raised by exchanging heat with the high-temperature compressed air introduced into the heat exchanger 1 (primary cooling unit 23) from the introduction port 21, and discharged to the rear chamber 26. And it is pumped out of the heat exchanger 1 from the discharge port 22.

  As described above in detail, according to the heat exchanger 1 of this compressed air dehumidifier, the cooler 2 is divided into a plurality of cooler blocks 3 and 3, so that the pipe expansion is performed by the pipe expansion jig. Can do. As a result, it is possible to shorten the time required for production compared to the expansion by water pressure, and it is possible to improve the yield by eliminating the rupture of the refrigerant pipe 11. Moreover, since the main pipe 11a is uniformly expanded, the main pipe 11a and the heat exchange fins 10 are in close contact with each other, so that variations in the heat exchange performance of the cooler can be eliminated. Furthermore, since it is not necessary to use a frame-shaped jig that was necessary for the expansion by water pressure, the time required for setting the frame-shaped jig can be reduced. Further, since water is not used, there is no need to dry the refrigerant pipe 11, and the time and cost required for drying can be reduced.

  Although the present invention has been described with reference to the embodiments, the present invention is not limited to the embodiments, and it goes without saying that many modifications can be made without departing from the spirit of the invention. .

DESCRIPTION OF SYMBOLS 1 Heat exchanger 2 Cooler 3 Cooler block 4 Compressed air dehumidifier 10 Heat exchange fin 11 Refrigerant piping 11a Main piping 11b Refrigerant inlet opening 11c Refrigerant outlet opening 12 Bend piping 13a, 13b Side plate 14, 15 Tube plate 14a, 15a End portion 14b, 15b, 15c Opening portion 16 Partition plate 17 Header piping 21 Inlet port 22 Outlet port 23 Primary cooling unit 24 Secondary cooling unit 25 Front chamber 26 Rear chamber 27 Drain pipe 28 Drain discharger 29 Connecting pipe 30 Refrigeration cycle 31 Compressor 32 Condenser 33 Expansion Valve 34 Fan

Claims (2)

  In a cooler that cools and dehumidifies by exchanging heat with compressed air as an evaporator of a refrigeration cycle, the cooler includes a plurality of heat exchange fins, meandering refrigerant piping that passes through the heat exchange fins, and the heat It comprises a plurality of cooler blocks composed of side plates provided at both ends of the exchange fin, and the cooler block inserts an extension jig to fix the heat exchange fin, the refrigerant pipe and the side plate. A method of manufacturing a cooler, wherein both ends of the plurality of cooler blocks are each held by a common tube plate.   The cooler is housed in a pressure vessel having an inlet and an outlet for compressed air, and the pressure vessel is configured to be able to discharge drain generated by the cooler to the outside of the pressure vessel when the compressed air is cooled. The heat exchanger of the compressed air dehumidifying device according to claim 1, wherein

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