JP2019020005A - Multi-tube type cooler and water cooler using the same - Google Patents

Abstract

To suppress variation in flow rate of fluid in a flow passage in which heat exchange is performed between the flow passage and refrigerant.SOLUTION: An inside flow passage 10c and outside flow passage 10d contacting with the radial inside and outside of a cooling coil 5 are separated from each other by the cooling coil 5 partitioning the radial inside and outside. These passage 10c, 10d communicate with each other over the whole circumference through a communication port 11c. Fluid introduced over the whole circumference from a communication port 11b evenly reciprocates in a set of the inside flow passage 10c and outside flow passage 10d along an axial direction. In that case, since reciprocated motion of fluid through a gap of the cooling oil 5 is regulated, turbulence hardly occurs in flow of the fluid along the axial direction.SELECTED DRAWING: Figure 8

Description

  The present invention relates to a multi-tube type cooler in which a plurality of tubes are arranged inside and outside in the radial direction, and a chilled water machine using the same.

  Conventionally, a multi-tube type cooler in which a plurality of tubes are arranged inside and outside in the radial direction is known. For example, as shown in FIG. 12, Patent Document 1 describes a cooler 34 in which a plurality of tubes 30 to 32 and a cooling coil 33 are arranged concentrically. The cooling coil 33 is in a state where there is a gap between adjacent coils, that is, the coil is wound sparsely, and is disposed in a substantially cylindrical space existing between the outer tube 30 and the inner tube 31. Has been. The fluid supplied from the inlet pipe 35 flows upward in the outermost space in which the cooling coil 33 is disposed, and then is guided radially inward while folding the inner space in the axial direction. It is discharged to the outside from the inner pipe 32 of the shaft core.

Japanese Patent Laid-Open No. 5-52486

  However, in the conventional cooler described above, in the space where the cooling coil is arranged, that is, in the flow path where heat exchange with the refrigerant flowing through the cooling coil is performed, the flow velocity of the fluid to be cooled varies, and the slow flow portion is Arise. This is because the cooling coil is sparsely wound, so that the fluid moves in the radial direction through the gap between adjacent coils, and the flow in the axial direction is disturbed. Thus, for example, when the fluid is cooled to near the solidification temperature, the fluid partially solidifies in the slow flow portion of the flow channel in contact with the cooling coil, and the solidified product grows rapidly and the flow channel is A situation such as blocking can occur. In order to prevent such a situation, the set temperature (target cooling temperature of the fluid) itself has to be set higher with a temperature margin that does not cause partial solidification. Also, the presence or absence of solidification in the flow path can be determined by detecting the temperature of the flow path using a temperature sensor installed in the flow path. However, when solidification occurs only in a part of the flow path, the temperature sensor does not always exist in that part, and providing an infinite number of temperature sensors in the entire flow path is realistic both in terms of structure and cost. It is difficult to properly determine partial coagulation because it is not appropriate.

  Therefore, an object of the present invention is to suppress variation in the flow rate of the fluid to be cooled in the flow path in which heat exchange with the refrigerant is performed.

  The first invention provides a multi-tube cooler in which a plurality of tubes are arranged inside and outside in the radial direction. The multi-tube cooler includes a cylindrical heat exchanger, a first pipe, a second pipe, an inner flow path, an outer flow path, a first communication port, and a second communication port. And have. The heat exchanger cools the fluid by exchanging heat with the refrigerant flowing inside. The 1st pipe | tube is arrange | positioned at the radial inside of a heat exchanger. The 2nd pipe | tube is arrange | positioned at the radial direction outer side of the heat exchanger. The inner flow path is a space between the inside of the heat exchanger and the outside of the first tube, and the fluid flows in one axial direction. The outer channel is a space between the outer side of the heat exchanger and the inner side of the second tube, and the fluid flows in the opposite direction to the inner channel. The first communication port is provided upstream of the inner channel and the outer channel, and introduces fluid over the entire circumference to one end side in the axial direction of the inner channel or the outer channel. The second communication port communicates the inner flow path and the outer flow path over the entire circumference on the other end side opposite to the one end side in the heat exchanger.

  Here, in the first invention, the first communication port may be provided in the first pipe. In this case, the fluid is introduced over the entire circumference of the inner channel through the first communication port, and reciprocates in the axial direction from the inner channel to the outer channel through the second communication port. On the top, it is released to the outside.

  In the first invention, the distance between the outer side of the heat exchanger and the inner side of the second pipe is preferably narrower than the distance between the outer side of the first pipe and the inner side of the heat exchanger. More preferably, the radial cross-sectional area of the outer channel (the space formed between the outside of the heat exchanger and the inside of the second tube) is set to the inner channel (the inside of the heat exchanger, the first Is set to be substantially the same as the radial cross-sectional area of the space formed between the outside of the tube.

  In 1st invention, you may attach the heat-transfer member which a refrigerant | coolant does not flow to at least one of the internal peripheral surface and outer peripheral surface of a heat exchanger along an axial direction. In addition, a temperature sensor that detects the temperature of the channel may be provided in at least one of the inner channel and the outer channel. Furthermore, a third tube may be arranged on at least one of the inside of the first tube and the outside of the second tube. In this case, the third tube and the adjacent tube (at least one of the first tube and the second tube) form a multi-tube structure, and the fluid flows in the axial direction in the space.

  2nd invention provides the cold water machine which cools the water as said fluid using the multipipe-type cooler which concerns on the said 1st invention. This cold water machine has a water tank in which water as a fluid is stored, and the multi-tube cooler disposed in the water tank.

  Here, in the second invention, the water chiller pumps out the water stored in the water tank, cools the pumped water with a multi-tube cooler, and then discharges the water into the water tank. You may further have the water supply system which sends the water stored in the water tank directly to the exterior, without passing through a multi-tube type cooler.

  According to the first invention, the inside and outside in the radial direction are partitioned by the heat exchanger and separated into the inner flow path and the outer flow path, and through the second communication port provided at the other end in the axial direction, The inner path and the outer path are communicated over the entire circumference via the second communication port. The fluid introduced over the entire circumference from the first communication port provided on one end side in the axial direction passes through the inner channel and the outer channel in which the radial flow of the heat exchanger is restricted in the axial direction. Make a round trip uniformly along. By rectifying the fluid in this way, it is possible to effectively suppress variations in the flow velocity of the fluid in the inner channel and the outer channel in contact with the heat exchanger.

  According to the second invention, by using the multi-tube cooler according to the first invention, variation in the flow rate of water in the flow path in contact with the heat exchanger is suppressed, so that water partially freezes. In addition, it is possible to effectively suppress the ice generated by freezing from rapidly growing and blocking the flow path. Thereby, the temperature margin for preventing partial solidification is eased, and it becomes possible to efficiently generate cooler cooling water.

Overall view of multi-tube cooler according to the first embodiment 1 is a developed perspective view of a multi-tube cooler according to a first embodiment. Radial direction sectional view of a multiple tube type cooler concerning a 1st embodiment The figure which shows the 1st example of the shape of a communicating port The figure which shows the 2nd example of the shape of a communicating port The figure which shows the 3rd example of the shape of a communicating port External perspective view of cooling coil Diagram showing the flow of fluid inside the multi-tube cooler Diagram showing fluid flow around cooling coil Schematic of multi-tube cooler according to the second embodiment Schematic general view of a chiller according to the third embodiment Explanatory drawing of cooler in the prior art

(First embodiment)
FIG. 1 is an overall view of a multi-tube cooler according to a first embodiment. The multi-tube cooler 1 is used for cooling a fluid to be cooled (for example, water). The figure shows a state in which each member is slightly expanded in the axial direction so that the positional relationship between the members constituting the multi-tube cooler 1 can be easily understood. The plurality of members 2, 3, 5 are completely accommodated inside the tube 4, and the opening at the upper end is closed by the transparent lid 6.

  The multi-tube cooler 1 has a plurality of tubes 2 to 4 and a cooling coil 5 as an example of a heat exchanger, and these are arranged inside and outside in the radial direction. In this embodiment, a total of three tubes are arranged, two inside the cooling coil 5 and one outside. Specifically, the first inner tube 2 is disposed on the axial center of the multi-tube cooler 1. The second inner pipe 3 is arranged on the outer side in the radial direction of the first inner pipe 2 at a predetermined interval so as to surround the entire circumference. A cooling coil 5 is arranged on the outer side in the radial direction of the second inner pipe 3 with a predetermined interval so as to surround the entire circumference. Further, an outer tube 4 is arranged on the outer side in the radial direction of the cooling coil 5 with a predetermined interval so as to surround the entire circumference. In this way, the opening at the upper end is closed by the transparent lid 6 in a state where the three tubes 2 to 4 and the cooling coil 5 are arranged concentrically. The reason for using the transparent lid 6 is to make it possible to visually check the internal state from the outside during the operation of the multi-tube cooler 1, and thereby, for example, whether or not the solidification of the fluid has occurred in the internal flow path. It can be determined without disassembling.

  FIG. 2 is a developed perspective view of the multi-tube cooler 1, and FIG. 3 is a radial cross-sectional view thereof. In the present embodiment, since the multi-tube cooler 1 is assumed to be used in a storage tank that stores fluid, the multi-tube cooler 1 is mounted on the bottom surface 7a of the storage tank. The partition part 8 to be placed is provided, and this partition part 8 also constitutes a part of the constituent members of the multi-tube cooler 1. The first inner pipe 2 itself or another pipe connected thereto penetrates the bottom surface 7a of the storage tank vertically as an inlet pipe 9 to which a fluid to be cooled is supplied from the outside.

  The multi-tube cooler 1 can be used alone without being arranged in the storage tank. In that case, a closing member corresponding to the partition portion 8 is used to close the opening at the lower end of the multi-tube cooler 1, and an outlet pipe for discharging the fluid can be separately attached in addition to the inlet pipe 9 for introducing the fluid. That's fine.

  The first inner pipe 2 communicates with the inlet pipe 9 at the lower end side in the axial direction, and has a small diameter communication port 11a penetrating the inner and outer sides in the radial direction at the upper end side closed by the transparent lid 6. A plurality of them are arranged uniformly over the circumference. In the assembled state in which the opening at the upper end is closed by the transparent lid 6, the inner and outer spaces in the radial direction of the first inner tube 2 become flow paths 10a and 10b through which fluid flows. That is, the internal space of the first inner tube 2 corresponds to the flow path 10a, and a substantially cylindrical space existing between the outside of the first inner tube 2 and the inside of the second inner tube 3 is It corresponds to the flow path 10b. These flow paths 10a and 10b communicate with each other on the upper end side through the communication port 11a.

  The second inner pipe 3 is closed at its upper end side by a transparent lid 6, and at its lower end side, a communication port 11b (see FIG. 8) penetrating the inside and outside in the radial direction is provided over the entire circumference. It has been. Thereby, the inner and outer spaces in the radial direction in the second inner pipe 3 communicate with each other on the lower end side through the communication port 11b. When the fluid introduced from the axial inlet pipe 9 is discharged from the outside in the radial direction, the communication port 11b is located upstream of the flow paths 10c and 10d in contact with the cooling coil 5, and the fluid flows into these flow paths 10c and 10d. It becomes the introduction port to introduce.

  Various shapes can be used as the shape of the communication port 11b for guiding the fluid over the entire circumference. For example, as shown in FIG. 4, the second inner tube 3 may be arranged so that the lower end of the second inner tube 3 is positioned slightly above the bottom surface 7a of the storage tank. In this case, a gap (opening) generated over the entire circumference between the bottom surface 7a of the storage tank and the lower end of the second inner tube 3 becomes the communication port 11b. Further, the lower end of the second inner tube 3 may be closed by contacting the bottom surface 7a, and the communication port 11b may be provided in the inner tube 3 itself. For example, as shown in FIG. 5, on the lower end side of the second inner pipe 3, a plurality of substantially rectangular openings extending in the circumferential direction are provided at equal intervals so that the entire circumference opens substantially equally. These are defined as the communication port 11b. Furthermore, as shown in FIG. 6, on the lower end side of the second inner pipe 3, a large number of small holes may be provided uniformly over the entire circumference, and these may be used as communication ports 11b. The shape as described above can be similarly applied to the other communication ports 11a, 11c, and 11d (see FIG. 8).

  As shown in FIGS. 2 and 3, the cooling coil 5 is disposed in a substantially cylindrical space existing between the outside of the second inner tube 3 and the inside of the outer tube 4. This space is partitioned on the inside and outside in the radial direction by the cooling coil 5, and as a flow path through which the fluid flows, the inner flow path 10 c in contact with the inner peripheral surface of the cooling coil 5 and the outer flow in contact with the outer peripheral surface thereof. The path 10d is separated.

  FIG. 7 is an external perspective view of the cooling coil 5. As the structure of the cooling coil 5 in which the inside and the outside in the radial direction are partitioned, a structure in which the coil is wound tightly as shown in the figure can be used. The reason for partitioning the radial direction of the coil into the inside and the outside is to restrict the fluid from passing in the radial direction between the inner flow path 10c and the outer flow path 10d. Therefore, it is sufficient that the coils are in contact with each other so that the fluid does not substantially pass, and it is not required that the coils be completely closed by welding or the like. In addition, a plurality of sparsely wound coils are prepared, and a plurality of coils are nested so that the other coil enters the adjacent gap of one coil, thereby being densely wound. Alternatively, a coil structure may be prepared and used as the cooling coil 5. Furthermore, regardless of the density of the coil, the gap between the coils may be closed by sticking or welding a sheet-like member to at least one of the inner peripheral surface and the outer peripheral surface of the wound coil. In this case, in order to suppress a decrease in cooling efficiency, it is preferable to use a highly heat-conductive material (for example, an aluminum foil) as the sheet-like member. As the flow of the refrigerant in the cooling coil 5, the refrigerant supplied from the inlet 5a flows spirally along the flow path of the cooling coil 5 and is discharged to the outside from the outlet 5b.

  Further, as shown in FIG. 7, at least one of the inner peripheral surface and the outer peripheral surface of the cooling coil 5 is attached with a rod-shaped heat transfer member 5 c that does not flow a refrigerant along the axial direction in order to improve cooling performance. It has been. The internal and external flow paths 10c and 10d that are in contact with the cooling coil 5 communicate only through the communication port 11c on the upper end side, and are otherwise separated from each other. Therefore, in each of the flow paths 10c and 10d, the fluid is axial. Flows uniformly along the direction. By extending the heat transfer member 5c along the axial direction, the cooling efficiency by heat exchange can be enhanced without impeding the axial flow in the flow paths 10c and 10d. As the heat transfer member 5c, it is preferable to use a metal (for example, copper) having a high thermal conductivity, like the material of the cooling coil 5. Moreover, you may attach to the perimeter of the inner peripheral surface / outer peripheral surface of the cooling coil 5 equally using the multiple heat-transfer member 5c.

  As shown in FIG. 3, the outer flow path 10d is provided with at least one temperature sensor 12 for detecting the temperature of the flow path in order to detect the presence or absence of solidification in the flow path. The temperature sensor 12 may be provided not in the outer flow path 10d but in the inner flow path 10c, or may be provided in both the inner flow path 10c and the outer flow path 10d.

  The lower end surface of the cooling coil 5 is in contact with the upper end surface of the partition portion 8 provided in the bottom portion 7a of the storage tank, thereby restricting the fluid in the radial direction on the lower end side of the cooling coil 5. In addition, a communication port 11c penetrating the inside and outside in the radial direction is provided on the upper end side of the cooling coil 5 over the entire circumference. By this communication port 11c, the inner flow path 10c, which is a substantially cylindrical space between the inside of the cooling coil 5 and the outside of the second inner tube 3, and the outside of the cooling coil 5 and the inside of the outer tube 4 are connected. The outer flow path 10d, which is a substantially cylindrical space, communicates with each other on the upper end side. Further, a communication port 11d penetrating the inside and outside in the radial direction is provided on the lower end side of the outer tube 4 over the entire circumference. When the fluid introduced from the axial inlet pipe 9 is discharged from the outside in the radial direction, the communication port 11d is located downstream of the flow paths 10c and 10d in contact with the cooling coil 5, and passes through these flow paths 10c and 10d. It becomes the discharge port which discharges the cooled fluid. It should be noted that the outermost communication port 11d is no longer required to be opened in the radial direction because the flow path no longer exists on the radially outer side, and is not necessarily opened in the axial direction. Fluid may be released.

  The plurality of tubes 2 to 4 constituting the multi-tube cooler 1 are screwed through the transparent lid 6 in a concentrically arranged state, whereby the multi-tube cooler 1 is integrated as a whole. It becomes. During maintenance of the multi-tube cooler 1, each member can be easily disassembled by removing the screws. If there is no need to consider maintainability, the openings of the plurality of tubes 2 to 4 may be closed by a method other than screwing, for example, a form in which a lid is welded to the openings. That is, you may use the obstruction | occlusion pipe | tube which does not have an opening part. In this sense, in this specification, “tube” is used as a term having the same meaning as a cylindrical body regardless of whether or not there is an opening.

  FIG. 8 is a diagram showing the flow of fluid inside the multi-tube cooler 1. The fluid supplied from the axial inlet pipe 9 flows upward in the axial direction through a flow path 10 a formed inside the first inner pipe 2. The fluid guided to the upper end side through the flow path 10a is uniformly guided over the entire circumference radially outward through the communication port 11a on the upper end side, and then moves downward in the axial direction through the flow path 10b. Flowing. The fluid guided to the lower end side through the flow path 10b is uniformly guided over the entire circumference radially outward through the communication port 11b on the lower end side, and then the inner flow path 10c is moved upward in the axial direction. It flows toward. Since the inner flow path 10c is in contact with the cooling coil 5, heat exchange is performed between the refrigerant flowing through the cooling coil 5 and the fluid flowing through the inner flow path 10c, thereby cooling the fluid. The fluid guided to the upper end side through the inner channel 10c is uniformly guided over the entire circumference radially outward through the communication port 11c on the upper end side, and then the outer channel 10d is moved downward in the axial direction. It flows toward. Since the outer flow path 10d is in contact with the cooling coil 5 similarly to the inner flow path 10c, the fluid flowing through the outer flow path 10d is further cooled. Then, the fluid guided to the lower end side through the outer flow path 10d is uniformly discharged over the entire circumference radially outward through the communication port 11d (release port) on the lower end side. Thus, in the inner flow paths 10a to 10d of the multi-tube cooler 1, the fluid is guided radially outward while reciprocating in the axial direction.

  As described above, according to the present embodiment, the inside and outside of the cooling coil 5 are partitioned to be separated into the inner flow path 10c and the outer flow path 10d, and all of the paths 10c and 10d are connected via the communication port 11c. Communicate over the circumference. As a result, the fluid introduced over the entire circumference from the communication port 11b (immediately upstream of the cooling coil 5) serving as an inlet for introducing the fluid into the cooling coil 5, the inner flow as shown by the arrows in FIG. A series of flow paths including the path 10c and the outer flow path 10d are uniformly reciprocated along the axial direction. At that time, since the flow of the fluid through the gap of the cooling coil 5 is restricted, the fluid flow along the axial direction is hardly disturbed. By rectifying the fluid in this way, it is possible to effectively suppress variations in the flow velocity of the fluid in the inner channel 10c and the outer channel 10d that are in contact with the cooling coil 5.

  Suppressing the variation in flow rate is particularly advantageous when cooling the fluid to near the solidification temperature in that it can prevent unexpected solidification at a low flow rate portion. This is because a temperature margin that does not cause partial solidification is not required, and the set temperature (the target cooling temperature of the fluid) can be set lower accordingly. In addition, even if solidification occurs, the solidification of the entire heat transfer surface of the cooling coil 5 is uniform, not partial solidification. Therefore, the solidification state can be accurately performed with a small number without installing a large number of temperature sensors 12. It becomes possible to discriminate.

  Further, according to the present embodiment, when the inside and outside of the cooling coil 5 are partitioned and separated into the inner channel 10c and the outer channel 10d, a single channel is formed without partitioning the inside and outside of the cooling coil 5. Compared with, the cross-sectional area of a flow path becomes small and a fluid flows quickly. Thereby, the cooling efficiency of the fluid by the cooling coil 5 can be improved.

  In the present embodiment, the radially inner side of the cooling coil 5 has a double pipe structure (inner pipes 2 and 3), and the fluid reciprocates in the axial direction. As a result, the inner flow path 10c and the flow path 10b located immediately inside thereof are in contact with each other via the wall portion of the inner tube 3, and heat exchange occurs between the fluids flowing through the inner flow path 10c. Even if this occurs, rapid growth of the solidified product can be suppressed.

  In addition, according to the present embodiment, the communication port 11d (direct downstream side of the cooling coil 5) serving as a discharge port for discharging the fluid cooled by the cooling coil 5 to the outside is open over the entire circumference. It is difficult for the fluid to stay on the downstream side of the cooling coil 5, and the upstream side is not adversely affected. As a result, it is possible to more effectively suppress variations in flow velocity in the inner flow path 10c and the outer flow path 10d.

  Furthermore, according to the present embodiment, a plurality of inner pipes 2 and 3 are arranged on the inner side in the radial direction of the cooling coil 5 so that the fluid supplied from the inlet pipe 9 spreads uniformly over the entire circumference of the cooling coil 5. Rectified. Thus, the multi-tube cooler 1 can be downsized by effectively utilizing the internal space of the cooling coil 5 and arranging the rectifying mechanism inside the cooling coil 5.

  In the above-described embodiment, the example in which the fluid introduced from the axial inlet pipe 9 is discharged from the radially outer side has been described. However, the fluid flow shown in FIGS. May be discharged from the inlet pipe 9 of the shaft core. In this case, the fluid stored in the storage tank is introduced into the inside of the multi-tube cooler 1 from the entire circumference through the communication port 11d located upstream of both the inner channel 10c and the outer channel 10d. The Further, in the case of the multi-tube cooler 1 that is used alone without being placed in the storage tank, the fluid introduced from one point of the inlet pipe 9 is rectified so as to spread uniformly over the entire circumference. It is sufficient to guide to the communication port 11d.

  Furthermore, from the viewpoint of suppressing variation in flow velocity in the inner flow path 10c and the outer flow path 10d, as shown in FIG. 3, the interval L1 between the outside of the cooling coil 5 and the inside of the outer pipe 4 is a cooling rate. It is preferable that the distance L2 between the inner side of the coil 5 and the outer side of the inner tube 3 is narrower (L1 <L2). This is because when the distances L1 and L2 are the same, the outer flow path 10d has a larger radial cross-sectional area than the inner flow path 10c, and the flow speed of the outer flow path 10d becomes relatively slow. . If L1 <L2, the difference in flow rate between the two can be reduced. In particular, if the intervals L1 and L2 are set so that the radial cross-sectional area of the inner flow path 10c and the radial cross-sectional area of the outer flow path 10d are substantially the same, the flow rate of the inner flow path 10c and the outer flow path The flow rate of 10d can be made approximately equal.

  Each of the modifications as described above can be similarly applied to a second embodiment to be described later.

(Second Embodiment)
FIG. 10 is a schematic view of a multi-tube cooler according to the second embodiment. This multi-tube cooler 1 is composed of a plurality of tubes 2 to 4 and a cooling coil 5 as in the first embodiment, but unlike the first example, the cooling coil 5 It is arranged between the tubes 2 and 3. Thus, the radially inner side of the cooling coil 5 has a single tube structure (inner tube 2), and the radially outer side thereof has a double tube structure (inner tube 3 and outer tube 4). Since the other points are the same as those in the first embodiment, the same reference numerals as those used in the first embodiment are attached, and the description thereof is omitted here.

  As indicated by an arrow in the figure, the fluid supplied from the inlet pipe 9 flows through the flow path 10a formed in the first inner pipe 2 toward the upper side in the axial direction. The fluid guided to the upper end side through this flow path 10a is uniformly guided over the entire circumference radially outward through the communication port 11a on the upper end side (introduction port of the cooling coil 5). It flows in the channel 10c downward in the axial direction. Since the inner flow path 10c is in contact with the cooling coil 5, the fluid is cooled by heat exchange with the refrigerant. The fluid guided to the lower end side through the inner flow path 10c is uniformly guided over the entire circumference in the radial direction via the communication port 11b on the lower end side, and then flows upward in the axial direction through the outer flow path 10d. It flows toward. Since the outer flow path 10d is in contact with the cooling coil 5, the fluid flowing through the outer flow path 10d is further cooled. The fluid guided to the upper end side through the outer flow path 10d is uniformly guided over the entire circumference in the radial direction via the communication port 11c on the upper end side, and then flows downward in the axial direction through the flow path 10e. Flowing. The fluid guided to the lower end side through the flow path 10e is uniformly discharged over the entire circumference radially outward through the communication port 11d (exit) on the lower end side.

  Thus, according to this embodiment, in addition to the same effects as those of the first embodiment described above, the radially outer side of the cooling coil 5 has a double tube structure (the inner tube 3 and the outer tube 4). Therefore, the fluid reciprocates in the axial direction. As a result, the outer flow path 10d and the flow path 10e on the outer side thereof are in contact with each other through the wall portion of the inner tube 3, and heat exchange occurs between the fluids flowing through both of them, so that the fluid is solidified in the outer flow path 10d. Even if this occurs, rapid growth of the solidified product can be suppressed.

  In each of the above-described embodiments, a configuration in which the radially inner side of the cooling coil 5 has a double tube structure (first embodiment) and a configuration in which the radially outer side of the cooling coil 5 has a double tube structure ( Although the second embodiment) is illustrated, a multiple tube structure using a plurality of tubes may be employed on both the inside and the outside. However, the minimum requirement for the configuration of the present invention is that there are one tube each in the radial direction of the cooling coil 5 and a total of two tubes, and at least one of the inside and the outside is multiplexed. The pipe structure is not essential as a superordinate concept of the present invention.

(Third embodiment)
FIG. 11 is a schematic overall view of a water chiller according to the third embodiment. The chiller 20 cools water as a fluid to be cooled by using the multi-tube coolers 1, 1 ′ (hereinafter collectively referred to as “1”) according to the above-described embodiments and modifications thereof. In addition, it produces cold water of low temperature close to the freezing temperature used in various fields such as food, fisheries and physics and chemistry as well as beverage applications. In this specification, “water” or “cold water” is used to mean a liquid containing moisture, and not only fresh water but also salt water, beverages (juice, beer, etc.), brine (containing water), etc. including.

  The chilled water machine 20 is mainly composed of a water tank 7, a multi-tube cooler 1, a water circulation system 21, a water supply system 22, a water supply system 23, and a refrigerant circulation system 24. The water tank 7 stores water cooled by the multi-tube cooler 1, and the multi-tube cooler 1 is installed on the bottom surface 7a. The water circulation system 21 is connected between the inlets and outlets of the water in the multi-tube cooler 1, pumps out the water stored in the water tank 7 by the pump 21a, supplies the water to the multi-tube cooler 1, and multi-tube type The water cooled by the cooler 1 is discharged into the water tank 7. Moreover, the temperature sensor 21b is provided in the flow path of the cold water in the water circulation system 21, and thereby the temperature of the cold water flowing through the flow path, in other words, the water temperature of the water tank 7 is detected. Furthermore, as described above, the multi-tube cooler 1 includes the temperature sensor 12 in order to detect the frozen state of the internal flow path.

  The water supply system 22 supplies water into the water tank 7 until a predetermined storage amount is reached when the storage amount is reduced by the level sensor 25 that detects the water level in the water tank 7. The water supply system 23 directly supplies the cold water stored in the water tank 7 to the outside without going through the multi-tube cooler 1. In the present embodiment, the water supply system 23 is attached to the upstream side of the multi-tube cooler 1 in the water circulation system 21, specifically, between the pump 21 a and the multi-tube cooler 1. The pumped cold water is sent to the outside.

  The refrigerant circulation system 24 is connected to the refrigerant inlet / outlet in the cooler 1, and includes a refrigerator 24a including a compressor and a condenser, and an expansion valve 24b. During operation of the refrigerator 24a, the refrigerant circulates through the refrigerant circulation system 24 while repeating the refrigeration cycle. That is, the refrigerant supplied to the refrigerator 24a is compressed by the compressor to become high-temperature and high-pressure gas, condensed (liquefied) by the condenser, and then discharged from the refrigerator 24a as high-pressure liquid. The high-pressure liquefied refrigerant is depressurized by the expansion valve 24b and is supplied to the cooler 1 as a low-pressure liquid. The low-pressure liquefied refrigerant evaporates (vaporizes) by heat exchange with water in the cooler 1, and returns to the refrigerator 24a as low-pressure gas. In such a refrigerant refrigeration cycle, the water flowing in the cooler 1 is cooled by the heat of vaporization when the low-pressure liquefied refrigerant changes into a gas phase.

  As described above, according to the present embodiment, the use of the above-described multi-tube cooler 1 suppresses the variation in the flow velocity on the flow path where heat exchange with the refrigerant is performed. It is possible to effectively suppress freezing and the rapid growth of ice generated by freezing and blocking the flow path.

  In addition, according to the present embodiment, the structure of the multi-tube cooler 1 is such that partial freezing of water is unlikely to occur. Therefore, in controlling the chiller 1, a temperature margin that does not cause partial solidification occurs. There is no need to consider. Thereby, the preset temperature of cold water can be made into a low temperature (for example, 1 degrees C or less) rather than the conventional cold water machine, and such cryogenic cold water can be stored in the water tank 7. FIG. As a result, even if it does not go through the multi-tube type cooler 1, it is possible to send cryogenic cold water as it is.

  Furthermore, according to the present embodiment, even when freezing occurs in the internal flow path of the multi-tube cooler 1, not the partial freezing, but the entire heat transfer surface of the cooling coil 5 is uniformly frozen. It is possible to accurately determine the frozen state with only the temperature sensor 12. Thereby, the cold water machine 1 can be continuously operated while a certain amount of ice is attached to the cooling coil 5.

  In each of the above-described embodiments, the cooling coil 5 in which the coil is tightly wound is used as a heat exchanger that cools the fluid by heat exchange with the refrigerant. However, the present invention is not limited to this. Rather, if it is of a cylindrical shape that partitions the inside and outside in the radial direction and separates the inner flow path and the outer flow path (it is not necessary to be a strict cylinder), including the refrigerant flow path inside, Any structure heat exchanger may be used.

1, 1 'multiple pipe type cooler 2 first inner pipe 3 second inner pipe 4 outer pipe 5 cooling coil 6 transparent lid 7 storage tank (water tank)
7a Bottom surface 8 Partition 9 Inlet pipe 10a-10e Flow path 11a-11d Communication port 12 Temperature sensor 20 Chilled water 21 Water circulation system 21a Pump 21b Temperature sensor 22 Water supply system 23 Water supply system 24 Refrigerant circulation system 24a Refrigerating machine 24b Expansion valve 25 Level Sensor

Claims (9)

In a multi-tube cooler in which a plurality of tubes are arranged inside and outside in the radial direction,
A cylindrical heat exchanger that cools the fluid by heat exchange with the refrigerant flowing in the interior, while the inside and outside in the radial direction are partitioned,
A first pipe disposed radially inward of the heat exchanger;
A second pipe disposed radially outside the heat exchanger;
An inner channel that is a space between the inside of the heat exchanger and the outside of the first tube, in which the fluid flows in one axial direction;
An outer channel that is a space between the outside of the heat exchanger and the inside of the second tube, and in which the fluid flows in a direction opposite to the inner channel;
A first communication port that is provided upstream of the inner channel and the outer channel, and that introduces the fluid over the entire circumference on one end side in the axial direction of the inner channel or the outer channel;
A multiplex having a second communication port that communicates the inner channel and the outer channel over the entire circumference on the other end side opposite to the one end side in the heat exchanger. Tube cooler. The first communication port is provided in the first pipe,
The fluid is introduced over the entire circumference of the inner channel through the first communication port, and axially from the inner channel to the outer channel through the second communication port. The multi-tube cooler according to claim 1, wherein the multi-tube cooler is discharged to the outside after reciprocating.   The distance between the outside of the heat exchanger and the inside of the second pipe is narrower than the distance between the outside of the first pipe and the inside of the heat exchanger. 2. A multi-tube type cooler described in 2.   The radial cross-sectional area of the outer flow path between the outside of the heat exchanger and the inside of the second tube is the inside of the heat exchanger and the outside of the first tube. 4. The multi-tube cooler according to claim 3, wherein the multi-tube cooler is substantially the same as a radial cross-sectional area of the inner flow path.   5. The heat transfer member through which the refrigerant does not flow is attached along at least one of an inner peripheral surface and an outer peripheral surface of the heat exchanger along an axial direction. The multi-tube type cooler described in 1.   6. The multiple tube according to claim 1, further comprising a temperature sensor that is provided in at least one of the inner channel and the outer channel and detects the temperature of the channel. Type cooler. A third tube disposed on at least one of the inside of the first tube and the outside of the second tube;
The fluid flows in an axial direction in a space between the first pipe or the second pipe adjacent to the third pipe and the third pipe. The multi-tube type cooler described in any of the above. In a chiller that cools water,
A water tank in which water as a fluid is stored;
A multi-tube cooler disposed in the water tank,
The chilled water machine, wherein the multi-tube cooler is a multi-tube cooler according to any one of claims 1 to 7. A water circulation system that pumps out water stored in the water tank, cools the pumped water by the multi-tube cooler, and discharges the water into the water tank;
9. The chiller according to claim 8, further comprising a water supply system that directly supplies water stored in the water tank to the outside without passing through the multi-tube cooler.

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