JP7133293B2 - Multi-tube cooler and water chiller using the same - Google Patents

Description

The present invention relates to a multi-tube cooler in which a plurality of tubes are arranged radially inside and outside, and a water chiller using the same.

2. Description of the Related Art Conventionally, a multi-tube cooler is known in which a plurality of tubes are arranged inside and outside in the radial direction. 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 concentrically arranged. The cooling coil 33 is in a state where there is a gap between adjacent coils, that is, the coil is sparsely wound, and is arranged in a substantially cylindrical space existing between the outer tube 30 and the inner tube 31. It is The fluid supplied from the inlet pipe 35 flows upward through the outermost space in which the cooling coil 33 is arranged, and then is guided radially inward while axially folding back the inner space. It is discharged to the outside from the inner tube 32 of the shaft core.

JP-A-5-52486

However, in the above-described conventional cooler, the flow velocity of the fluid to be cooled varies in the space where the cooling coil is arranged, that is, the flow path where heat is exchanged with the refrigerant flowing through the cooling coil, and there are portions where the flow is slow. occur. This is because the cooling coils are sparsely wound, so the fluid flows radially through the gaps between the adjacent coils, causing turbulence in the flow in the axial direction. As a result, for example, when the fluid is cooled to near the solidification temperature, the fluid is partially solidified in a portion of the flow path in contact with the cooling coil, the flow of which is particularly slow, and the solidified material rapidly grows to fill the flow path. A clogging situation may occur. In order to prevent such a situation, the set temperature (the target cooling temperature of the fluid) itself must be set higher, taking into account a temperature margin that prevents partial solidification. Further, the presence or absence of coagulation in the channel can be determined by detecting the temperature of the channel using a temperature sensor installed in the channel. However, if solidification occurs only in a part of the flow path, the temperature sensor may not necessarily exist in that part, and it is realistic in terms of structure and cost to provide an innumerable number of temperature sensors in the entire flow path. It is difficult to adequately discriminate partial clotting because it is not targeted.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to suppress variations in flow velocity of a fluid to be cooled in a flow path where heat exchange with a refrigerant is performed.

A first invention provides a multi-tube cooler in which a plurality of tubes are arranged inside and outside in the radial direction. This multi-tube cooler includes a cylindrical heat exchanger, a first tube, a second tube, an inner channel, an outer channel, a first communication port, and a second communication port. and a third communication port. The heat exchanger is separated from the inside and outside in the radial direction of the coil, and cools the fluid to be cooled by heat exchange with the refrigerant flowing through the coil. The first tube is concentrically arranged radially inside the heat exchanger. The second tube is concentrically arranged radially outwardly of the heat exchanger. The inner flow path is the cylindrical space between the inside of the heat exchanger and the outside of the first tube through which fluid flows in one axial direction. The outer flow path is the cylindrical space between the outside of the heat exchanger and the inside of the second tube through which fluid flows in the opposite direction to the inner flow path. The first communication port introduces fluid over the entire circumference on one end side in the axial direction of one of the inner flow passage and the outer flow passage. 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 of the heat exchanger. The third communication port discharges the fluid along the entire circumference of the one end side of the other of the inner channel and the outer channel.

Here, in the first invention, the first communication port may be provided in the first pipe. In this case, the fluid was introduced over the entire circumference of the inner channel through the first communication port, and axially reciprocated from the inner channel toward the outer channel through the second communication port. Above, it is released to the outside.

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

In the first invention, a heat transfer member through which no refrigerant flows may be attached along the axial direction to at least one of the inner peripheral surface and the outer peripheral surface of the heat exchanger. Also, at least one of the inner channel and the outer channel may be provided with a temperature sensor for detecting the temperature of this channel. Additionally, a third tube may be positioned inside the first tube and/or outside the second tube. In this case, the third pipe and the pipes adjacent thereto (at least one of the first pipe and the second pipe) form a multi-pipe structure, and the fluid flows axially through the space.

A second invention provides a water chiller that cools water as the fluid by using the multi-tube cooler according to the first invention. This water cooler has a water tank in which water as a fluid is stored, and the multi-pipe cooler arranged in the water tank.

Here, in the second invention, the water cooler draws out the water stored in the water tank, cools the pumped-out water with a multi-tube cooler, and discharges the water into the water tank; It may further have a water supply system for directly supplying the water stored in the water tank to the outside without passing through the multi-pipe cooler.

According to the first invention, the inside and outside of the heat exchanger in the radial direction are separated into an inner flow channel and an outer flow channel, and through the second communication port provided at the other end in the axial direction, The inner path and the outer path are communicated with the second communication port over the entire circumference. The fluid introduced over the entire circumference from the first communication port provided at one end in the axial direction flows along the axial direction through the inner flow channel and the outer flow channel in which traffic in the radial direction of the heat exchanger is restricted. After reciprocating uniformly, the fuel is discharged over the entire circumference from the third communication port provided at one end side in the axial direction . By rectifying the fluid in this way, it is possible to effectively suppress variations in the flow velocity of the fluid in the inner and outer channels that are in contact with the heat exchanger.

According to the second invention, by using the multi-tube cooler according to the first invention, variations in the flow velocity of water in the flow path in contact with the heat exchanger are suppressed, so that the water is partially frozen. In addition, it is possible to effectively suppress the rapid growth of ice caused by freezing to block the flow path. As a result, the temperature margin for preventing partial solidification is relaxed, making it possible to efficiently generate cooling water at a lower temperature.

General view of multi-tube cooler according to the first embodiment 1 is an exploded perspective view of a multi-tube cooler according to the first embodiment; FIG. Radial cross-sectional view of a multi-tube cooler according to the first 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 communication port. The figure which shows the 3rd example of the shape of a communication port. Appearance perspective view of cooling coil Diagram showing fluid flow inside a multi-tube cooler Diagram showing fluid flow around the cooling coil Schematic diagram of a multi-tube cooler according to the second embodiment Schematic overall view of a water cooler according to a third embodiment Explanatory drawing of a cooler in the prior art

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

A multi-tube cooler 1 has a plurality of tubes 2 to 4 and a cooling coil 5 as an example of a heat exchanger, which 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, a first inner tube 2 is arranged in the axial center of the multi-tube cooler 1 . A second inner pipe 3 is arranged radially outwardly of the first inner pipe 2 with a predetermined interval so as to surround the entire circumference. Cooling coils 5 are arranged radially outwardly of the second inner tube 3 at predetermined intervals so as to surround the entire circumference. Furthermore, the outer tube 4 is arranged radially outwardly of the cooling coil 5 with a predetermined interval therebetween so as to surround the entire circumference. In this way, the three tubes 2 to 4 and the cooling coil 5 are concentrically arranged, and the opening at the upper end is closed by the transparent lid 6 . The reason for using the transparent lid 6 is to allow the internal state to be visually observed from the outside during the operation of the multi-tube cooler 1. This allows, for example, whether or not the fluid is solidified in the internal flow path. , can be determined without disassembly.

FIG. 2 is an exploded perspective view of the multi-tube cooler 1, and FIG. 3 is a radial sectional view thereof. In the present embodiment, it is assumed that the multi-pipe cooler 1 is placed in a storage tank for storing fluid, so the multi-pipe cooler 1 is mounted on the bottom surface 7a of the storage tank. A partitioning portion 8 is provided, and this partitioning portion 8 also constitutes a part of the constituent members of the multi-tube cooler 1 . The first inner pipe 2 itself or a separate pipe connected thereto penetrates vertically through the bottom surface 7a of the storage tank as an inlet pipe 9 to which the fluid to be cooled is supplied from the outside.

It should be noted that the multi-pipe cooler 1 can also be used alone without being placed in the storage tank. In that case, a closing member corresponding to the partition part 8 is used to block the opening at the lower end of the multi-tube cooler 1, and an outlet pipe for discharging the fluid is separately attached in addition to the inlet pipe 9 for introducing the fluid. Just do it.

The first inner pipe 2 communicates with the inlet pipe 9 at its lower end in the axial direction, and has a small-diameter communication port 11a penetrating inside and outside in the radial direction at its upper end closed by the transparent lid 6. A plurality of them are arranged evenly 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 serve as channels 10a and 10b through which the fluid flows. That is, the internal space of the first inner tube 2 corresponds to the flow path 10a, and the 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 via a communication port 11a.

The upper end of the second inner tube 3 is closed by a transparent lid 6, and the lower end of the second inner tube 3 is provided with a communication port 11b (see FIG. 8) extending radially from inside to outside. It is As a result, the inner and outer spaces in the radial direction of the second inner tube 3 communicate with each other on the lower end side via the communication port 11b. When the fluid introduced from the axial inlet pipe 9 is discharged from the radially outer side, the communication port 11b is positioned upstream of the flow paths 10c and 10d in contact with the cooling coil 5, and the fluid flows through these flow paths 10c and 10d. It becomes an 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 such 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) formed along the entire circumference between the bottom surface 7a of the storage tank and the lower end of the second inner tube 3 serves as the communication port 11b. Alternatively, the communication port 11b may be provided in the inner tube 3 itself after the lower end of the second inner tube 3 is closed by contacting the bottom surface 7a. For example, as shown in FIG. 5, a plurality of substantially rectangular openings extending in the circumferential direction are provided at equal intervals on the lower end side of the second inner tube 3 so that substantially the entire circumference is evenly opened. , and these are referred to as communication ports 11b. Furthermore, as shown in FIG. 6, a large number of small holes may be uniformly provided on the lower end side of the second inner pipe 3 over the entire circumference, and these may be used as the communication ports 11b. The shape as described above can be similarly applied to other communication ports 11a, 11c, and 11d (see FIG. 8).

As shown in FIGS. 2 and 3 , the cooling coil 5 is arranged 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 radially inside and outside by the cooling coil 5. As a fluid flow passage, an inner flow passage 10c in contact with the inner peripheral surface of the cooling coil 5 and an outer flow passage 10c in contact with the outer peripheral surface of the cooling coil 5 are provided. 10d are separated.

FIG. 7 is an external perspective view of the cooling coil 5. FIG. As the structure of the cooling coil 5 in which the inner and outer sides are separated in the radial direction, a densely wound coil as shown in the figure can be used. The reason why the radial direction of the coil is divided into the inner and outer sides is to restrict the flow of fluid 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 to such an extent that the fluid does not substantially flow back and forth, and it is not required that the coils are completely closed by welding or the like. In addition, by preparing a plurality of sparsely wound coils and arranging the plurality of coils in a nested manner so that the other coil enters the gap between the adjacent coils, the coils can be wound densely. 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 attaching or welding a sheet-like member to at least one of the inner and outer peripheral surfaces of the wound coil. In this case, it is preferable to use a material with high heat conductivity (for example, aluminum foil, etc.) as the sheet-like member in order to suppress a decrease in cooling efficiency. As for the flow of the coolant in the cooling coil 5, the coolant supplied from the inlet 5a spirally flows 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, a rod-shaped heat transfer member 5c through which no coolant flows is attached along the axial direction to at least one of the inner and outer peripheral surfaces of the cooling coil 5 in order to improve the cooling performance. It is The inner and outer channels 10c and 10d 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. flow uniformly along the direction. By extending the heat transfer member 5c along the axial direction, it is possible to increase the cooling efficiency by heat exchange without impeding the flow in the axial direction in these flow paths 10c and 10d. Similar to the material of the cooling coil 5, it is preferable to use a metal (for example, copper) with high thermal conductivity as the heat transfer member 5c. Alternatively, a plurality of heat transfer members 5c may be used and evenly attached to the entire circumference of the inner and outer peripheral surfaces of the cooling coil 5 .

As shown in FIG. 3, at least one temperature sensor 12 for detecting the temperature of the flow path is provided in the outer flow path 10d in order to detect the presence or absence of coagulation in this flow path. The temperature sensor 12 may be provided in the inner flow path 10c instead of the outer flow path 10d, 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 on the bottom portion 7a of the reservoir, thereby restricting the movement of the fluid in the radial direction on the lower end side of the cooling coil 5. In addition, a communication port 11c penetrating inside and outside in the radial direction is provided over the entire circumference on the upper end side of the cooling coil 5 . The communication port 11c provides an 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 space between the outside of the cooling coil 5 and the inside of the outer tube 4. The outer flow path 10d, which is a substantially cylindrical space therebetween, communicates with each other on the upper end side. In addition, a communication port 11d penetrating radially inside and outside 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 radially outer side, 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 a discharge port for discharging cooled fluid. As for the outermost communication port 11d, since there is no longer a channel on the radially outer side, it is not always necessary to open in the radial direction. Fluid may be released.

A plurality of tubes 2 to 4 constituting the multi-tube cooler 1 are concentrically arranged and screwed via a transparent lid 6, whereby the multi-tube cooler 1 is integrated as a whole. become. At the time of 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 opening. That is, closed tubes without openings may be used. In this sense, the term "tube" is used in this specification as a synonym for a cylindrical body that may or may not have an opening.

FIG. 8 is a diagram showing the flow of fluid inside the multi-tube cooler 1. As shown in FIG. The fluid supplied from the axial inlet pipe 9 flows upward in the axial direction through the flow path 10a formed inside the first inner pipe 2 . The fluid guided to the upper end side through the flow path 10a is uniformly guided radially outward over the entire circumference through the communication port 11a on the upper end side, and then flows downward in the axial direction through the flow path 10b. flow. The fluid guided to the lower end side through the flow path 10b is uniformly guided radially outward over the entire circumference through the communication port 11b on the lower end side, and then flows upward in the axial direction through the inner flow path 10c. flow towards. Since the inner flow path 10c is in contact with the cooling coil 5, heat is exchanged between the coolant 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 flow path 10c is uniformly guided radially outward over the entire circumference through the communication port 11c on the upper end side, and then flows downward in the axial direction through the outer flow path 10d. flow towards. 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 radially outward over the entire circumference through the communication port 11d (discharge port) on the lower end side. In this way, in the inner channels 10a to 10d of the multi-tube cooler 1, the fluid is led 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 into the inner flow path 10c and the outer flow path 10d, and the path 10c and 10d are fully connected through the communication port 11c. Communicate all around. As a result, the fluid introduced over the entire circumference from the communication port 11b (immediately upstream side of the cooling coil 5) serving as an inlet for introducing the fluid into the cooling coil 5 flows inward as indicated by the arrow in FIG. It reciprocates uniformly along the axial direction through a series of flow paths consisting of the path 10c and the outer flow path 10d. At this time, since the movement of the fluid through the gaps of the cooling coils 5 is restricted, the flow of the fluid along the axial direction is less likely to be disturbed. By rectifying the fluid in this manner, variations in the flow velocity of the fluid can be effectively suppressed in the inner flow path 10 c and the outer flow path 10 d that are in contact with the cooling coil 5 .

Suppression of variations in flow velocity is particularly advantageous when cooling a fluid to near the solidification temperature in that unexpected solidification can be prevented in portions where the flow velocity is low. This is because a temperature margin that does not cause partial solidification is not required, so the set temperature (target cooling temperature of the fluid) can be set lower accordingly. Moreover, even if solidification occurs, the entire heat transfer surface of the cooling coil 5 is solidified uniformly rather than partially solidified. It is possible to discriminate.

Further, according to the present embodiment, the inside and outside of the cooling coil 5 are partitioned to separate the inner flow path 10c and the outer flow path 10d, thereby forming a single flow path without partitioning the inside and the outside of the cooling coil 5. , the cross-sectional area of the flow path becomes smaller and the fluid flows faster. Thereby, the cooling efficiency of the fluid by the cooling coil 5 can be improved.

Further, in this embodiment, the radial inner side of the cooling coil 5 has a double pipe structure (the inner pipes 2 and 3), and the fluid axially reciprocates inside it. As a result, the inner flow path 10c and the flow path 10b immediately inside thereof come into contact with each other through the wall of the inner tube 3, and heat exchange occurs between the fluids flowing through both, so that the fluid solidifies in the inner flow path 10c. Even if this occurs, the rapid growth of the coagulum can be suppressed.

Further, according to the present embodiment, since the communication port 11d (immediately 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, Fluid is less likely to stagnate on the downstream side of the cooling coil 5 and does not adversely affect the upstream side. As a result, it becomes 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 radially inside 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. In this way, by effectively utilizing the internal space of the cooling coil 5 and arranging the rectifying mechanism inside the cooling coil 5, the multi-tube cooler 1 can be made smaller.

In the above-described embodiment, an example in which the fluid introduced from the inlet pipe 9 of the axial center is discharged from the radially outer side was described. may be discharged from the inlet pipe 9 of the shaft center. In this case, the fluid stored in the storage tank is introduced into the multi-tube cooler 1 from the entire circumference via the communication ports 11d located upstream of both the inner flow path 10c and the outer flow path 10d. be. In the case of a multi-pipe cooler 1 that is used alone without being placed in a storage tank, the fluid introduced from one point of the inlet pipe 9 is rectified so that it spreads uniformly over the entire circumference. , to the communication port 11d.

Furthermore, from the viewpoint of suppressing variations in flow velocity in the inner flow path 10c and the outer flow path 10d, as shown in FIG. It is preferably narrower than the distance L2 between the inside of the coil 5 and the outside of the inner tube 3 (L1<L2). This is because, if the intervals L1 and L2 are the same, the radial cross-sectional area of the outer flow path 10d is larger than that of the inner flow path 10c, and the flow velocity of the outer flow path 10d is relatively slow. . If L1<L2, the difference between the flow velocities of 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 velocity of the inner flow path 10c and the outer flow path 10d flow rate can be approximately equal.

Each modification as described above can be similarly applied to a second embodiment described later.

(Second embodiment)
FIG. 10 is a schematic diagram 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. It is arranged between the tubes 2,3. As a result, 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 other points are the same as those of the first embodiment, the same reference numerals as those used in the first embodiment are given, and explanations thereof are omitted here.

As indicated by arrows in the figure, the fluid supplied from the inlet pipe 9 flows upward in the axial direction through the channel 10a formed inside the first inner pipe 2. As shown in FIG. The fluid guided to the upper end side through this flow path 10a is uniformly guided radially outward over the entire circumference via the communication port 11a (introduction port of the cooling coil 5) on the upper end side, and then flows inward. It flows axially downward through the flow path 10c. Since this 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 radially outward over the entire circumference through the communication port 11b on the lower end side, and then flows upward in the outer flow path 10d in the axial direction. flowing towards 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 passage 10d is uniformly guided radially outward over the entire circumference through the communication port 11c on the upper end side, and then flows axially downward through the flow passage 10e. flow. Then, the fluid guided to the lower end side through the flow path 10e is uniformly discharged radially outward over the entire circumference through the communication port 11d (outlet) on the lower end side.

Thus, according to the present 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 immediately outside of it come into contact with each other through the wall of the inner tube 3, and heat exchange occurs between the fluids flowing through them, so that the fluid solidifies in the outer flow path 10d. Even if this occurs, the rapid growth of the coagulum can be suppressed.

In each of the above-described embodiments, the radially inner side of the cooling coil 5 has a double-tube structure (first embodiment), and the radially outer side of the cooling coil 5 has a double-tube structure ( 2nd embodiment), a multi-pipe structure using a plurality of pipes on both the inside and the outside may be adopted. However, the minimum requirement for the configuration of the present invention is that there are two pipes in total, one pipe inside and outside the cooling coil 5 in the radial direction, and at least one of the inside and the outside is multiplexed. A tubular structure is not essential as a generic concept of the present invention.

(Third embodiment)
FIG. 11 is a schematic general view of a water chiller according to the third embodiment. This water chiller 20 uses the multi-tube coolers 1 and 1' according to each of the above-described embodiments and their modifications (hereinafter collectively referred to as reference numeral "1") to cool water as a fluid to be cooled. It produces cold water at a low temperature close to the freezing temperature, which is used in various fields such as food, fisheries, physics and chemistry, as well as beverage applications. In this specification, "water" or "cold water" is used to mean a liquid containing water, and not only fresh water but also salt water, beverages (juice, beer, etc.), brine (containing water), etc. including.

The water chiller 20 mainly includes a water tank 7 , a multi-pipe cooler 1 , a water circulation system 21 , a water supply system 22 , a water supply system 23 , and a refrigerant circulation system 24 . Water cooled by the multi-pipe cooler 1 is stored in the water tank 7, and the multi-pipe cooler 1 is installed on the bottom surface 7a thereof. The water circulation system 21 is connected between the inlet and outlet of water in the multi-pipe cooler 1, pumps out the water stored in the water tank 7 with a pump 21a, supplies it to the multi-pipe cooler 1, and supplies the water to the multi-pipe cooler 1. The water cooled by the cooler 1 is discharged into the water tank 7. A temperature sensor 21b is provided in the cold water flow path of the water circulation system 21, and detects the temperature of the cold water flowing through the flow path, in other words, the temperature of the water tank 7. FIG. Furthermore, as described above, the multi-tube cooler 1 incorporates the temperature sensor 12 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 amount of water is reached when the level sensor 25 that detects the water level in the water tank 7 decreases the amount of water stored. The water supply system 23 directly supplies the cold water stored in the water tank 7 to the outside without passing through the multi-pipe cooler 1 . In this embodiment, the water supply system 23 is attached to the upstream side of the multi-pipe cooler 1 in the water circulation system 21, specifically, between the pump 21a and the multi-pipe cooler 1. The pumped cold water is sent to the outside.

The refrigerant circulation system 24 is connected to a refrigerant inlet/outlet of 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 into a high-temperature, high-pressure gas, condensed (liquefied) by the condenser, and released as a high-pressure liquid from the refrigerator 24a. The high-pressure liquefied refrigerant is decompressed by the expansion valve 24b and supplied to the cooler 1 as a low-pressure liquid. The low-pressure liquefied refrigerant evaporates (vaporizes) through heat exchange with water in the cooler 1, becomes low-pressure gas, and is returned to the refrigerator 24a. In such a refrigerant refrigeration cycle, the water flowing through the cooler 1 is cooled by the heat of vaporization when the low-pressure liquefied refrigerant undergoes a phase change to gas.

As described above, according to the present embodiment, by using the multi-tube cooler 1 described above, variations in the flow velocity on the flow path where heat exchange with the refrigerant is performed are suppressed, so that water is partially It is possible to effectively suppress freezing and rapid growth of ice caused by freezing to block the flow path.

Further, according to the present embodiment, the structure of the multi-pipe cooler 1 makes it difficult for water to partially freeze. need not be considered. As a result, the set temperature of the cold water can be set to a lower temperature (for example, 1° C. or less) than that of the conventional cold water machine, and such extremely low temperature cold water can be stored in the water tank 7 . As a result, cryogenic cold water can be sent as it is without passing through the multi-tube cooler 1 .

Furthermore, according to this embodiment, even if the internal flow path of the multi-tube cooler 1 freezes, the entire heat transfer surface of the cooling coil 5 freezes evenly instead of partially freezing. Only with the temperature sensor 12, it is possible to accurately determine the frozen state. As a result, the water chiller 1 can be operated continuously while the cooling coil 5 remains covered with ice to some extent.

In each of the above-described embodiments, the cooling coil 5 in which the coil is wound densely is used as the heat exchanger for cooling the fluid by heat exchange with the refrigerant, but the present invention is limited to this. Instead, if it is cylindrical (it does not have to be a strict cylinder) that separates the inner and outer channels by partitioning the inside and outside in the radial direction, including the coolant channel inside, Any structure of heat exchanger may be used.

Reference Signs List 1, 1' multi-tube cooler 2 first inner tube 3 second inner tube 4 outer tube 5 cooling coil 6 transparent lid 7 reservoir (water tank)
7a bottom surface 8 partition 9 inlet pipe 10a to 10e flow path 11a to 11d communication port 12 temperature sensor 20 water cooler 21 water circulation system 21a pump 21b temperature sensor 22 water supply system 23 water supply system 24 refrigerant circulation system 24a refrigerator 24b expansion valve 25 level sensor

Claims (9)

In a multi-tube cooler in which multiple tubes are arranged inside and outside in the radial direction,
a cylindrical heat exchanger that is partitioned radially inside and outside and that cools the fluid by heat exchange with the refrigerant flowing inside;
a first tube concentrically arranged radially inside the heat exchanger;
a second tube concentrically arranged radially outward of the heat exchanger;
a cylindrical space between the inside of the heat exchanger and the outside of the first tube, the inner channel through which the fluid flows in one axial direction;
a cylindrical space between the outside of the heat exchanger and the inside of the second tube, wherein the fluid flows in a direction opposite to the inner flow path;
a first communication port for introducing the fluid over the entire circumference on one axial end side of one of the inner flow channel and the outer flow channel;
a second communication port that 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 of the heat exchanger;
and a third communication port for discharging the fluid over the entire circumference at the one end of the other of the inner flow passage and the outer flow passage. The first communication port is provided in the first pipe,
The fluid is introduced along the entire circumference of the inner flow channel through the first communication port, and is introduced axially from the inner flow channel toward the outer flow channel through the second communication port. 2. The multi-tube cooler according to claim 1, wherein the cooling water is discharged to the outside after reciprocating to and from. 2. The space between the outside of the heat exchanger and the inside of the second tube is narrower than the space between the outside of the first tube and the inside of the heat exchanger. 2 multi-tube cooler. 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 equal to the radial cross-sectional area between the inside of the heat exchanger and the outside of the first tube. 4. The multi-tube cooler according to claim 3, wherein the radial cross-sectional area is the same as that of the inner channel. 5. The heat exchanger according to any one of claims 1 to 4, wherein a heat transfer member through which the refrigerant does not flow is attached along the axial direction to at least one of an inner peripheral surface and an outer peripheral surface of the heat exchanger. A multi-tube cooler as described in . 6. The multiplex pipe according to any one of claims 1 to 5, further comprising a temperature sensor provided in at least one of said inner flow channel and said outer flow channel to detect the temperature of said flow channel. formula cooler. further comprising a third tube positioned inside at least one of the first tube and outside the second tube;
7. The fluid flows axially through the space between the first or second pipe adjacent to the third pipe and the third pipe. A multi-tube cooler according to any one of . In a water chiller that cools water,
a water tank in which water as a fluid is stored;
a multi-tube cooler disposed in the water tank;
A water chiller, wherein the multi-pipe cooler is the multi-pipe cooler according to any one of claims 1 to 7. a water circulation system for pumping out the water stored in the water tank, cooling the pumped-out water with the multi-pipe cooler, and discharging it into the water tank;
9. The water chiller according to claim 8, further comprising a water supply system for directly supplying water stored in said water tank to the outside without passing through said multi-pipe cooler.

Images