Cold insulation system

Abstract

To quickly decrease a temperature inside a heat insulating container.SOLUTION: A blower 35 is arranged in a heat insulating container, and blows air to a cold insulation material 34 stored in the heat insulating container, thereby circulating the air cooled by the cold insulation material 34 in the heat insulating container. The blower 35 blows air, for example, along a main surface of the cold insulation material 34. The blower 35 has, for example, a blowout port that blows air to be blown onto the cold insulation material 34, and a suction port that suctions the air blown out of the blowout port from a direction approximately perpendicular to a direction in which the air is blown out through the blowout port. The blower 35 is, for example, a blower fan.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a refrigeration system. [Background technology]

[0002] Patent Document 1 discloses an air conditioning unit having a blower means for circulating air inside a transport box, and a cooling agent for cooling the air circulated by the blower means. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 5743247 Summary of the Invention [Problem to be solved by the invention]

[0004] The air conditioning unit of Patent Document 1 can strictly control the temperature inside the transportation box and keep it within a predetermined range even during transportation when power cannot be obtained from the outside. However, if the temperature inside the transport box is high and far outside the target temperature range, it takes time to lower the temperature inside the transport box to within the target temperature range, so it is necessary to bring the temperature inside the transport box within the target temperature range in advance. The present invention aims to solve such problems, for example. [Means for solving the problem]

[0005] The cooling system includes a blower that is disposed in the thermal insulation container and blows air onto the cold insulation material contained in the thermal insulation container, thereby circulating the air cooled by the cold insulation material within the thermal insulation container. Effect of the Invention

[0006] The blower blows air onto the cold insulation material, promoting heat exchange between the air and the cold insulation material, and enabling the temperature inside the insulated container to be lowered quickly. [Brief description of the drawings]

[0007] [Figure 1] FIG. 1 is a perspective view showing an example of a cold storage system. [Diagram 2] FIG. 2 is a perspective view showing an example of a cooling unit. [Diagram 3] FIG. [Figure 4] FIG. 2 is a perspective view showing an example of a blower device. [Diagram 5] FIG. 4 is a perspective view showing an example of a holding member. [Figure 6] FIG. 4 is a side cross-sectional view showing an example of a cooling unit. [Figure 7] Graph showing experimental results. [Figure 8] FIG. 4 is a graph showing static pressure / air volume characteristics of the blower device. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] With reference to FIG. 1, a refrigeration system 10 will be described. The refrigeration system 10 is a system that keeps a relatively small amount of refrigerated objects, such as frozen foods, at or below -15 degrees Celsius in order to transport the objects for a relatively short period of time, such as one hour. The cold storage system 10 includes, for example, an insulated container 12 and cold storage units 13a and 13b.

[0009] The insulated container 12 is a container made of an insulating material such as a vacuum insulating material, and contains an object to be kept cold in its internal space. For example, the container has a substantially rectangular box shape having a top panel 21, a front panel 22, a back panel 23, a left side panel 24, a right side panel 25, and a bottom panel 26. The top panel 21 has, for example, a top door 27. Also, the front panel 22 has, for example, a front door 28. FIG. 1 shows the top door 27 and the front door 28 in an open state. The top door 27 can be closed by rotating to the front side (-Y side) around the edge of the lower side (-Z side) as an axis. The front door 28 can be closed by rotating to the upper side (+Z side) around the edge of the rear side (+Y side) as an axis. By opening the top door 27 and the front door 28, it is possible to put in and take out an object to be kept cold. Also, by closing the top door 27 and the front door 28, it is possible to seal the internal space of the thermal insulation container 12. The shape of the door is not limited to the shape shown in the figure, and may be, for example, a shape in which the entire top panel 21 opens to one side toward the top (+Z side), a shape in which the entire front panel 22 opens to the front (-Y side), a shape in which the front panel 22 opens like a double door to the left and right (±X directions), or some other shape.

[0010] The cold storage units 13a and 13b are disposed in the insulated container 12 and cool an object to be kept cold that is accommodated in the insulated container 12. Cold insulation units 13a and 13b are arranged, for example, on bottom plate 26. In this case, it is preferable to arrange a rack or the like (not shown) on cold insulation units 13a and 13b to create a gap between the objects to be kept cold contained in insulated container 12 and cold insulation units 13a and 13b, so that the weight of the objects to be kept cold is not applied to cold insulation units 13a and 13b. The positions of cold storage units 13a and 13b are not limited to those shown in the figure, and may be, for example, inside front panel 22, back panel 23, left side panel 24, or right side panel 25, or may be below top panel 21. Cold storage units 13a and 13b may be disposed in different positions. Furthermore, the number of cold storage units is not limited to two, but may be only one, or may be three or more.

[0011] The cold insulation unit 13a will be described with reference to Fig. 2. The cold insulation unit 13b is similar, and therefore its description will be omitted. The cold insulation unit 13a includes, for example, a cold insulation material , a blower 35, and a holding member . The cold insulation material 34 is held by a holding member 36. The air blower 35 is fixed to the holding member 36, and is positioned on the rear side (+Y direction) when viewed from the cold insulation material 34.

[0012] The cold insulation material 34 will be described with reference to FIG. The ice pack 34 has, for example, a sealed case 41 filled with ice packs (not shown), and the ice packs are frozen by cooling in a refrigerator or the like, and then placed in the insulated container 12, where the heat of fusion absorbed by the ice packs as they melt cools the inside of the insulated container 12. The case 41 has, for example, a substantially rectangular plate shape perpendicular to the ±Z directions, and has four legs 42 and six through holes 43. The legs 42 are disposed at the four corners of the case 41 and protrude upward and downward (in the ±Z direction). This makes it possible to ensure a gap around the case 41. The through holes 43 penetrate the case 41 vertically (in the ±Z direction), which increases the surface area of ​​the case 41 and facilitates freezing and melting of the ice pack.

[0013] The blower 35 will be described with reference to FIG. The blower 35 blows wind (air) onto the cold insulation material 34 , thereby circulating the air cooled by the cold insulation material 34 within the heat-insulating container 12 . The blower 35 is, for example, a blower fan, and includes, for example, a case 51, a motor 54, and a fan (not shown). The case 51 is a hollow, generally cylindrical shape centered on an axis extending in the ±Z direction, and has, for example, an intake port 52 and an outlet port 53. The outlet port 53 protrudes, for example, toward the front (-Y direction) from a side surface of the case 51, and blows out air toward the front. As a result, the air blown out from the outlet port 53 is blown onto the cold insulation material 32. The intake port 52 is a generally circular hole provided near the center of the upper surface of the case 51, and draws in air, for example, from above (+Z direction). In this way, by drawing in air from a direction generally perpendicular to the direction in which air is blown out from the outlet port 53, the air in the heat-insulating container 12 can be efficiently circulated even if the internal space of the heat-insulating container 12 is narrow. Motor 54 is powered by power supplied from a storage battery (not shown) and rotates a fan arranged inside case 51, thereby drawing in air through intake port 52 and blowing the air drawn in through intake port 52 out through outlet port 53. The storage battery may be placed inside the thermal insulation container 12, but it is preferable to pull out the wiring from the thermal insulation container 12 and place it outside the thermal insulation container 12. This makes it possible to prevent a decrease in cooling efficiency due to heat generation from the storage battery.

[0014] The holding member 36 will be described with reference to FIG. The holding member 36 holds the cold insulation material 34 at a position where it is hit by the air blown out from the blower 35. The holding member 36 has a shape, for example, of a folded plate, and has, for example, a bottom surface portion 61, side surface portions 62 and 63, and edge portions 64 and 65. The bottom surface portion 61 is a substantially rectangular plate perpendicular to the ±Z direction. The bottom surface portion 61 may have a relatively large opening at a position where the cold insulation material 34 is held. In this way, when the bottom surface portion 61 of the holding member 36 is disposed at a position away from the inner surface of the insulating container 12, the air cooled by the cold insulation material 34 can go out of the holding member 36 through the opening. The side surface portion 62 has a generally rectangular plate shape perpendicular to the ±X directions, and extends from the edge on the −X side of the bottom surface portion 61 toward the +Z direction. The side surface portion 63 has a generally rectangular plate shape perpendicular to the ±X directions, and extends from the +X side edge of the bottom surface portion 61 in the +Z direction. The edge portion 64 has a generally rectangular plate shape perpendicular to the ±Z directions, and extends from the edge on the +Z side of the side portion 62 in the +X direction. The edge portion 65 has a generally rectangular plate shape perpendicular to the ±Z directions, and extends from the edge of the +Z side portion 63 toward the −X direction. The height (length in ±Z directions) of the side portions 62 and 63 is slightly larger than the thickness (length in ±Z directions) of the cold insulation material 34. Also, the width (length in ±X directions) of the bottom portion 61 is slightly larger than the width (length in ±X directions) of the cold insulation material 34. This allows the side portions 62 and 63 and the edge portions 64 and 65 to function as guide rails, and the cold insulation material 34 can be inserted and held between the bottom portion 61 and the edge portions 64 and 65, and between the side portions 62 and 63. Instead of the edges 64 and 65, a top surface portion of the same size as the bottom surface portion 61 may be provided. In this case, a relatively large opening is provided in the top surface portion so that the air cooled by the cold insulation material 34 can go out of the holding member 36. Also, an opening is provided at a position corresponding to the intake port 52 so as not to hinder the air blower 35 from drawing in air. In this way, if the structure is such that the air blower 35 is covered with the holding member 36, the air blower 35 can be protected. The cover protecting the air blower 35 may be a member different from the holding member 36. In order to prevent the opening at the position corresponding to the intake port 52 from being blocked by an object to be kept cool placed on the cover protecting the air blower 35, protrusions of, for example, 5 mm in height protruding upward from the top surface of the cover may be provided, for example, at the four corners of the cover. Also, in order to facilitate wiring from the storage battery to the air blower 35, a power jack connected to the air blower 35 may be provided. In addition, instead of a guide rail, for example, a protrusion that fits into through hole 43 may be provided at a position corresponding to through hole 43 of ice pack 34 so that ice pack 34 can be held in the correct position, or other means may be used to hold ice pack 34 in the correct position.

[0015] The operation of cold insulation unit 13a will be described with reference to Fig. 6. Note that the operation of cold insulation unit 13b is similar, so the description will be omitted. The blower 35 is fixed to the bottom surface portion 61 of the holding member 36 so that the center of the cold insulation material 34 held by the holding member 36 is positioned in front of the air outlet 53. This allows the cold insulation material 34 to be accurately positioned in a correct position. The blower 35 may be detachably fixed to the holding member 36 by a fixing means such as double-sided tape or hook-and-loop fastener. As described above, air that is sucked into blower 35 from the +Z direction through intake port 52 is blown out from outlet 53 in the -X direction. The air blown out from the air outlet 53 is divided into the upper and lower parts of the cold insulation material 34, one of which travels along the upper (+Z side) surface of the cold insulation material 34, and the other travels along the lower (-Z side) surface of the cold insulation material 34. This promotes heat exchange between the air blown out from the air outlet 53 and the cold insulation material 34, and the air blown out from the air outlet 53 is cooled. Then, the air cooled by the cold insulation material 34 diffuses into the insulated container 12, so that the entire internal space of the insulated container 12 is quickly cooled, and the object to be cooled contained therein can be kept cool.

[0016] The surfaces of the cold insulation material 34 face in various directions, but the surface with the largest area facing the same direction is called the "main surface." In the case of the cold insulation material 34 in this example, the surface facing the +Z direction and the surface facing the -Z direction are the "main surfaces." In this way, by blowing air along the main surfaces of the cold insulation material 34, the air blown out from the air outlet 53 can be efficiently cooled.

[0017] The height (length in the ±Z direction) of the air outlet 53 is preferably greater than the height (length in the ±Z direction) of the cold insulation material 34. In this way, part of the air blown out from the air outlet 53 travels straight without hitting the +X side surface of the cold insulation material 34 and can proceed along the +Z side surface of the cold insulation material 34, so that the cold insulation material 34 efficiently cools the air. However, if the height of the air outlet 53 is too high, part of the air blown out from the air outlet 53 travels to a position away from the cold insulation material 34 in the +Z direction and cannot exchange heat with the cold insulation material 34. For this reason, the height of the air outlet 53 is preferably 1.5 times or less the height of the cold insulation material 34.

[0018] The width (length in the ±Y direction) of the air outlet 53 is preferably smaller than the width (length in the ±Y direction) of the cold insulation material 34. If the width of the air outlet 53 is larger than the width of the cold insulation material 34, part of the air blown out from the air outlet 53 will proceed straight without hitting the +X side surface of the cold insulation material 34 and will proceed along the ±X side surfaces of the cold insulation material 34, and the efficiency of heat exchange will be lower than when the air proceeds along the ±Z side surfaces of the cold insulation material 34. However, if the width of the air outlet 53 is too narrow, a range will be generated on the ±Z side surface of the cold insulation material 34 that does not exchange heat with the air blown out from the air outlet 53. For this reason, the width of the air outlet 53 is preferably 0.2 times or more the width of the cold insulation material 34.

[0019] Furthermore, when the cold insulation material 34 is in the shape of a substantially rectangular plate as in this example, it is preferable to arrange the long side direction of the rectangle parallel to the direction in which air is blown out from the air outlet 53. This can lengthen the time for the air blown out from the air outlet 53 to exchange heat with the cold insulation material 34, and can efficiently cool the air blown out from the air outlet 53. To generalize this, it is preferable to arrange the cold insulation material 34 in an orientation such that the length of its main surface in the direction parallel to the direction in which air is blown out from the air outlet 53 is as long as possible.

[0020] It is important that the air blown out from the air outlet 53 exchanges heat with the cold insulation material 34 for as long as possible. Therefore, it is preferable that the air blowing device 35 is one that blows out air with high directionality, such as a blower fan.

[0021] It is preferable that the direction in which intake port 52 draws in air is the direction that is as open as possible inside thermal insulation container 12. For example, if cold storage units 13a and 13b are disposed below top panel 21 (-Z side), intake port 52 is disposed so as to draw in air from the -Z direction. Similarly, if cold storage units 13a and 13b are disposed inside back panel 23 (-Y side), intake port 52 is disposed so as to draw in air from the -Y direction.

[0022] It is preferable that cold insulation units 13a and 13b are detachably fixed in thermal insulation container 12. This facilitates the work of attaching and detaching cold insulation material 34 to and from cold insulation units 13a and 13b. For example, cold insulation units 13a and 13b are provided with wings, and cold insulation units 13a and 13b are fixed to thermal insulation container 12 by hooking the wings to the inside of thermal insulation container 12.

[0023] When the cold insulation material 34 is arranged vertically (parallel to the ±Z directions), such as by arranging the cold insulation units 13a and 13b inside the front panel 22, the back panel 23, the left side panel 24, and the right side panel 25, if the cold insulation material 34 is arranged on the upper side (+Z side) of the blower 35, the cold insulation material 34 can be replaced without removing the cold insulation units 13a and 13b from the insulated container 12. Conversely, if the cold insulation material 34 is arranged on the lower side (-Z side) of the blower 35, it is possible to prevent condensation generated on the cold insulation material 34 from scattering. Alternatively, the cold insulation material 34 may be arranged next to the blower 35.

[0024] Also, it is preferable that the gap between the cold storage units 13a and 13b and the inner wall of the heat-insulating container 12 is as narrow as possible, because air remaining in the gap does not contribute to cooling the object to be kept cold.

[0025] The ice pack to be filled in ice pack 34 is selected to have an appropriate melting point based on the properties of the object to be kept cold. For example, frozen foods are required by law to be stored at or below -15 degrees Celsius, so the melting point of the ice pack needs to be -15 degrees Celsius or lower, and it is preferable for the melting point to be even lower in order to maintain the temperature at or below -15 degrees Celsius even when the door is opened and closed during transportation. However, if the melting point is too low, it becomes difficult to freeze the ice pack, so it is preferable that the melting point is -30 degrees C. In this way, the ice pack can be easily frozen in an ice pack freezer with an internal temperature of -35 degrees to -40 degrees C.

[0026] Also, a sensor may be provided to detect when the top door 27 or the front door 28 of the insulated container 12 is opened, and when it detects that the door is open, the blower 35 may be stopped. In this way, the amount of cold air flowing out of the insulated container 12 can be minimized.

[0027] There are two aspects to "cold storage." One is the "cooling power" that lowers the temperature from a high temperature to a low one. The other is the "cold retention power" that maintains an environment at a lower temperature than the surroundings. Ice packs are better at "cold retention power" than dry ice, but their "cooling power" is inferior. In particular, to maintain a low temperature, such as when keeping frozen foods cold, the "cooling power" that cools the inside of an insulated container from the environmental temperature is important. The reason why ice packs have a weak cooling power is that they are a phase transition phenomenon that does not involve evaporation. However, the characteristics of air itself also have an effect. In other words, air has an extremely low thermal conductivity, so it is used as an insulating material, and it does not transmit heat well. For this reason, ice packs can only absorb the surrounding heat in the immediate vicinity of the case in which they are filled, and the cold of the cooled air is not easily transferred to or mixed with the surrounding air. Air also has the characteristic of having a low specific heat, meaning that it heats up and cools down easily. This is because when freely moving air molecules come into contact with a stationary object, they can easily cause the molecules in the other object to vibrate. Air molecules do not easily transfer heat to each other because they are constantly moving around, whereas air transfers heat easily to the molecules of stationary objects.

[0028] Therefore, by blowing air directly onto the ice pack, the air being cooled by the ice pack is constantly replaced. By creating a flow near the ice pack, the speed of heat exchange between the air and the ice pack is improved, and the cooling power of the ice pack can be increased.

[0029] In contrast, the conventional blower is used to stir the air in the insulated container and mix it with the air cooled by the ice pack, so it is not possible to improve the heat exchange speed between the air and the ice pack, and therefore it is not possible to increase the cooling power.

[0030] In order to confirm the effect of the cooling system 10, the following experiment was carried out. <Experiment 1> The insulated container was made of a board made of 50 mm of rigid polyurethane foam covered with a laminated sheet of polyethylene (PE) cloth. The inside dimensions of the insulated container 12 were 720 mm x 620 mm x 880 mm. The cooling unit's blower device was a blower fan manufactured by Sanyo Denki Co., Ltd. (product name "San Ace B97", model number "109BM12GC2-1"). A mobile battery was used as a storage battery to power the blower. However, because the input voltage of the blower fan used was 12V DC, a boost circuit was inserted between the mobile battery and the blower fan. The battery box containing the mobile battery and boost circuit was stored in a pocket on the outside of the insulated container, and connected to the blower fan with a lead wire. The cooling material used in the cooling unit was a cooling material manufactured by Sugiyamagen Co., Ltd. (product name "Cool Lab (registered trademark) -31"). The size of the cooling material was 285 mm x 210 mm x 32 mm. The melting point of the cooling material was -31 degrees Celsius, and the amount of cooling material filled was 800 g. The distance between the blower fan outlet and the cooling material was 8 cm. The three cooling units were placed on the bottom plate of the insulated container, and a tray-like cover was placed on top of them. Additionally, three cooling materials (cooling materials manufactured by Sugiyamagen Corporation (product name "Cool Lab (registered trademark) -31")) were placed in pockets provided under the top panel of the insulated container as auxiliary insulation materials.

[0031] The thus constructed cooling system (excluding the cooling material) was left in a temperature-controlled room (room temperature 35 degrees Celsius) for 20 minutes with the door fully open, until the internal space of the insulated container was at 35 degrees Celsius. After that, the six ice packs that had been completely frozen in a quick-freezing ice pack freezer (internal temperature -35°C) were placed in the above-mentioned positions, the door was closed, and the container was left in a temperature-controlled room (internal temperature 35°C) while the temperature inside the insulated container was measured with a temperature logger. The measurement positions were eight points: the center of the top surface of the bottom panel, the center of the inside surface of the front panel, the lower and upper centers of the inside surfaces of the left and right side panels, the center of the inside surface of the back panel, and the center of the bottom surface of the top panel.

[0032] <Experiment 2> The insulated container used was the same as in Experiment 1. Two cooling units, the same as in Experiment 1, were installed on the bottom plate of the insulated container, and four supplementary cooling materials were installed in pockets under the top plate. In other words, the number of cooling materials was kept the same, but the number of cooling units was reduced by one. Using the cooling system constructed in this way, the temperature inside the insulated container was measured under the same conditions as in Experiment 1.

[0033] <Experiment 3> The insulated container used was the same as in Experiment 1. No cooling unit was installed, and six cooling materials were used separately, the same as in Experiment 1. The arrangement of the cooling materials was the same as in Experiment 1, with three installed above the bottom plate and three installed below the top plate. In other words, the number of cooling materials was the same as in Experiments 1 and 2. Using the cooling system constructed in this way, the temperature inside the insulated container was measured under the same conditions as in Experiment 1.

[0034] The experimental results will be described with reference to FIG. The horizontal axis indicates the time elapsed since the door of the insulated container was closed, and the vertical axis indicates the measured temperature. A solid line 91 represents the temperature measured at the center of the top surface in Experiment 1. The dashed line 92 represents the temperature measured at the center of the top surface, which is representative of the temperatures measured in Experiment 2. The dashed line 93 represents the temperature measured at the center of the top surface, which is representative of the temperatures measured in Experiment 3.

[0035] In experiment 1, it took about 14 minutes for the temperature inside the insulated container to reach -15 degrees Celsius at the center of the bottom, about 16 minutes at the center of the front, the center of the lower left and right sides, the center of the back, and the center of the top, and about 18 minutes at the center of the upper left and right sides. The temperature inside the insulated container eventually reached -19 degrees Celsius. This shows that it is possible to rapidly cool the inside of the insulated container and maintain a cold state even on a very hot day.

[0036] In experiment 2, the time it took for the temperature inside the insulated container to reach -15 degrees Celsius was approximately 27 minutes at the center of the bottom, approximately 28 minutes at the center of the front, the center of the lower left and right sides, the center of the back, and the center of the top, and approximately 33 minutes at the center of the upper left and right sides. Compared to experiment 1, the time it took to cool was longer, but it was found that the cooling effect was sufficient.

[0037] In experiment 3, the temperature inside the insulated container ultimately dropped to -8 degrees Celsius at the center of the bottom, and only 0 to -3 degrees Celsius at the center of the front, the center of the lower left and right sides, the center of the back, the center of the top, and the center of the upper left and right sides. Therefore, it was found that a sufficient cooling effect cannot be obtained without using a cooling unit.

[0038] <Test 4> The insulated container used was the same as in Experiment 1. No cooling unit was installed, and 16 sheets of the same cooling materials as in Experiment 1 were used alone. Four cooling materials were placed in a pocket under the top panel, two in each of the pockets on the inside of the left and right side panels, and four each in the pockets on the inside of the front and back panels. Using the cooling system constructed in this way, the temperature inside the insulated container was measured under the same conditions as in Experiment 1.

[0039] In experiment 4, it took about 18 minutes for the temperature inside the insulated container to reach -15 degrees Celsius. In this way, by increasing the number of ice packs, it is possible to obtain the same cooling speed and effect as in experiment 1 without using a cooling unit, but the number of ice packs required is about 2.5 times as many.

[0040] <Test 5> The insulated container used was the same as in Experiment 1. Three cooling units, the same as in Experiment 1, were installed under the top plate of the insulated container, and three supplementary cooling materials were installed on the bottom plate. In other words, the positions of the cooling units and the supplementary cooling materials were reversed. Using the cooling system constructed in this way, the temperature inside the insulated container was measured under the same conditions as in Experiment 1.

[0041] In experiment 5, it took about 35 minutes for the temperature inside the insulated container to reach -15 degrees Celsius. Compared to experiment 1, the cooling rate was slower, but the temperature unevenness was smaller and the temperature uniformity inside the insulated container was higher. Furthermore, in experiment 5, the ice pack in the cooling unit placed on the top melted faster than the supplementary ice pack placed on the bottom. The ice pack in the cooling unit placed on the top can be replaced without removing the object to be cooled from the insulated container, so if the ice pack in the cooling unit is replaced as needed during transport, it becomes possible to transport the goods when the door is opened and closed frequently or for long periods of time.

[0042] <Experiment 6> The insulated container used was the same as in Experiment 1. As the cooling unit's air blower, an axial fan manufactured by Sanyo Denki Co., Ltd. (product name "San Ace 80", model number "9GA0812P2S001") was used instead of a blower fan. The rated input power of the blower fan used in other experiments was 7.2 W, whereas the rated input power of the axial fan used in experiment 6 was 9.96 W. Therefore, in order to roughly match the power consumption, two axial fans were installed for each of the three cooling materials placed on the top surface. In addition, three supplementary cooling materials were placed on the bottom surface. Using the cooling system constructed in this way, the temperature inside the insulated container was measured under the same conditions as in Experiment 1.

[0043] In experiment 6, it was found that the temperature inside the insulated container ultimately dropped to -8 degrees Celsius at the center of the bottom, and only to between 0 and -3 degrees Celsius at the center of the front, the center of the lower left and right sides, the center of the back, the center of the top, and the center of the upper left and right sides, meaning that a sufficient cooling effect could not be obtained.

[0044] In this way, it is preferable that the air blowing device of the cooling unit is a blower fan rather than an axial fan. The reason for this will be considered below.

[0045] The difference in static pressure / air volume characteristics between a blower fan and an axial flow fan will be described with reference to FIG. The horizontal axis indicates the air volume, and the vertical axis indicates the static pressure. A solid line 94 indicates the static pressure air volume characteristic of the blower fan. A solid line 95 indicates the static pressure air volume characteristic of the axial flow fan.

[0046] When the ventilation resistance is small, an axial fan will have a larger air volume, but when the ventilation resistance becomes large, a blower fan has a higher static pressure and therefore a larger air volume. For this reason, it can be said that a blower fan is more suitable for circulating air in the narrow internal space of an insulated container. In this experiment, no items to be kept cold were placed inside the insulated container, but in actual operation, items to be kept cold will be placed inside the insulated container for transportation, which would increase the ventilation resistance even further. Therefore, it can be said that a blower fan is more suitable. Furthermore, the static pressure airflow characteristics of the axial flow fan include a rotating stall region 96. Therefore, if the arrangement of the object to be kept cool changes, the condition may become unstable.

[0047] In addition, the direction in which the axial flow fan draws in and blows out the air is aligned in a straight line, so if the axial flow fan is installed on the same inner wall as the inner wall of the insulated container in which the cold pack is installed, the space on the side where the axial flow fan draws in the air becomes narrow, resulting in increased ventilation resistance. In contrast, the blower fan draws in and blows out air at a right angle, so even if the blower fan is installed on the same inner wall as the insulated container in which the cold pack is installed, the space on the side where the blower fan draws in air is large, preventing large ventilation resistance.

[0048] Axial fans have a large maximum air volume and are therefore suited to stirring the air inside an insulated container and mixing it with the air cooled by the ice packs; however, blower fans are more suited to increasing the cooling power of the ice packs.

[0049] The above-described embodiment is an example for facilitating understanding of the present invention. The present invention is not limited thereto, and includes various modifications, changes, additions, or deletions without departing from the scope defined by the appended claims. This can be easily understood by those skilled in the art from the above description. [Explanation of symbols]

[0050] 10 cold storage system, 12 insulated container, 13a, 13b cold storage unit, 21 top panel, 22 front panel, 23 rear panel, 24 left side panel, 25 right side panel, 26 bottom panel, 27 top door, 28 front door, 34 cold storage material, 35 blower, 36 retaining member, 41 case, 42 legs, 43 through hole, 51 case, 52 intake port, 53 exhaust port, 54 motor, 61 bottom portion, 62, 63 side portions, 64, 65 edges, 91, 94, 95 solid lines, 92, 93 dashed lines, 96 rotating stall area.

Claims

1. A blower device that is disposed in a thermal insulation container and blows air onto a cold insulation material contained in the thermal insulation container, thereby circulating the air cooled by the cold insulation material within the thermal insulation container. Equipped with a cooling system.

2. The air blower blows the air along a main surface of the cold insulation material. The cooling system of claim 1.

3. The blower device is An outlet for blowing the air onto the cooling material; an intake port that draws in the air blown out from the air outlet in a direction substantially perpendicular to the direction in which the air outlet blows out; The cooling system of claim 1 or 2, comprising:

4. The blower device is a blower fan.

3. The cooling system of claim 1 or 2.

5. a holding member for holding the cold insulation material at a position where the air blown out from the blower hits the cold insulation material; The refrigeration system of claim 1 or 2, further comprising:

6. A storage battery that supplies power for operating the air blower The refrigeration system of claim 1 or 2, further comprising:

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