Unit cooler

Abstract

The present invention provides a unit cooler that reduces equipment costs and reliably closes the outlet with a door without increasing the warehouse load during defrosting, thereby preventing the defrost heat from leaking into the warehouse. [Solution] The system comprises a housing 2, a discharge hood 10 provided at the outlet 4 of the housing 2, a fan 5 provided at the discharge hood 10 which draws air from inside the refrigerated warehouse F into the housing 2 via the intake port 3 of the housing 2 and blows the air into the refrigerated warehouse F via the outlet 4, a heat exchanger 6 provided inside the housing 2 which cools the air drawn into the housing 2 and generates cold air, a defrosting device 7 which defrosts the heat exchanger 6, and a damper 8 provided at the outlet 4 so as to be openable and closable, which is opened during the cooling operation of the refrigerated warehouse F to allow cold air to be blown out from the outlet 4. When the defrosting device 7 is started, the fan 5 is reversed and a backflow W2 is generated which causes the damper 8 to close the outlet 4.

Description

Technical Field

[0001] The present invention relates to a unit cooler.

Background Art

[0002] A unit cooler that blows out cooled air (hereinafter simply referred to as cold air) into a refrigerated warehouse (hereinafter simply referred to as a warehouse) includes a housing, a heat exchanger provided inside the housing, a suction port and a blowout port provided in the housing, and a fan. It sucks in the air inside the warehouse from the suction port, generates cold air in the heat exchanger, and then blows out the cold air from the blowout port by the fan.

[0003] In such a unit cooler, when the moisture contained in the air becomes cold air, it may turn into frost and adhere to the heat exchanger or the like. In order to prevent the cooling capacity of the unit cooler from decreasing due to this, defrosting is performed regularly. As defrosting methods, there are various methods such as a heater heating method in which a heater is provided and heated, a water spraying method in which water is sprayed, and a warm brine method in which heated brine is circulated.

[0004] For example, in the case of the heater heating method, in order to increase the defrosting efficiency and prevent the heat of the heater from flowing out into the warehouse and the temperature in the warehouse from rising, a door (damper) that opens and closes the blowout port may be provided. The door opens the blowout port by the wind pressure of the cold air during the operation of the unit cooler. On the other hand, when defrosting is performed, the operation of the unit cooler is stopped, so the wind pressure of the cold air does not act and the door closes the blowout port by its own weight.

[0005] In this case, frost could accumulate on the door, preventing it from functioning properly and sometimes preventing it from completely closing the air outlet during defrosting. Therefore, various technologies have been proposed to prevent frost buildup on the door. For example, a technology has been disclosed in which a heater is installed within the shaft that rotatably supports the door (see, for example, Patent Document 1). With this configuration, the heater heats the rotating part of the door, preventing frost buildup on this rotating part. As a result, the door can always be operated normally. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2010-261661 [Overview of the Initiative] [Problems that the invention aims to solve]

[0007] However, the conventional technology described above had several drawbacks: the cost of the unit cooler was increased due to the heater being installed in the door, the heat from the heater increased the load on the warehouse, and the door would not be able to completely block the air outlet because it was closed by its own weight.

[0008] Therefore, the present invention provides a unit cooler that reduces equipment costs and reliably closes the outlet with a door without causing an increase in warehouse load during defrosting, thereby preventing the defrosting heat from leaking into the warehouse. [Means for solving the problem]

[0009] To solve the above problems, the unit cooler according to the present invention is a unit cooler installed in a cold storage warehouse, comprising: a housing; an intake port and an outlet port provided in the housing; an outlet hood provided in the outlet; a fan provided in the outlet hood that draws air from inside the cold storage warehouse into the housing via the intake port and blows the air into the cold storage warehouse via the outlet; a heat exchanger provided in the housing that cools the air drawn into the housing and generates cold air; a defrosting device that defrosts the heat exchanger; and a door provided at the outlet port that can be opened and closed, which is opened during the cooling operation of the cold storage warehouse to allow the cold air to be blown out from the outlet, wherein the outlet port is closed by the door using a backflow generated by reversing the fan when the defrosting device is started.

[0010] This configuration allows the door to be forcibly closed by a fan during defrosting. Therefore, it eliminates the need to install heaters or other components on the door, as was done in conventional systems, thus reducing equipment costs.

[0011] In the above configuration, the rotational speed of the fan when the defrosting device is started is lower than the rotational speed of the fan when blowing the cold air into the refrigerated warehouse.

[0012] This configuration prevents excessively strong headwinds. It also minimizes the impact when closing the door, preventing damage to the unit cooler. By changing the rotation speed in accordance with the forward and reverse rotation of the fan, it becomes possible to reduce the running costs of the unit cooler.

[0013] In the above configuration, when blowing the cold air into the refrigerated warehouse, the fan is positioned downstream of the door from the cold air.

[0014] This configuration allows the fan to be positioned as far away as possible from the defrosting device and heat exchanger. This prevents, for example, the steam generated during defrosting from adhering to the fan and freezing on it. As a result, the fan can operate stably.

[0015] In the above configuration, the temperature range of the refrigerated warehouse is -40°C or lower.

[0016] Thus, by providing the above configuration to a unit cooler used at extremely low temperatures of -40°C or below, where there is a high risk of door freezing, it is possible to effectively prevent the heat generated during defrosting from leaking into the warehouse.

[0017] In the above configuration, the defrosting is performed using heated warm brine.

[0018] By configuring it in this way, defrosting can be performed using warm brine, which has a lower heating temperature compared to a heater, thus effectively preventing the heat generated during defrosting from leaking into the warehouse.

[0019] In the above configuration, the heat exchanger comprises a fin module having a plurality of fins, each having a first through-hole and a second through-hole formed at offset positions from each other when viewed from a first direction, and the plurality of fins being spaced apart in the first direction; a refrigerant flow path provided in the fin module so as to penetrate the first through-hole of each of the plurality of fins in the first direction, and through which the refrigerant flows; and a warm brine flow path provided in the fin module so as to penetrate the second through-hole of each of the plurality of fins in the first direction, and through which the warm brine flows, wherein the outer diameter of the warm brine flow path is smaller than the outer diameter of the refrigerant flow path.

[0020] By configuring it in this way, the heat of the warm brine can be efficiently transferred to the fins of the heat exchanger or the like. As a result, after making the outer diameter of the warm brine flow path smaller than the outer diameter of the refrigerant flow path, it is possible to exhibit desired defrost performance. And by making the outer diameter of the warm brine flow path smaller than the outer diameter of the refrigerant flow path, since the flow rate of the brine flowing through the warm brine flow path can be suppressed, a defrost device with reduced device cost can be provided. By making the outer diameter of the warm brine flow path smaller than the outer diameter of the refrigerant flow path, an increase in the size of the heat exchanger associated with providing the warm brine flow path can also be suppressed.

Effect of the Invention

[0021] According to the present invention, the device cost of the unit cooler can be reduced, and it is possible to prevent the warm heat during defrost from flowing out into the warehouse.

Brief Description of the Drawings

[0022] [Figure 1] It is a schematic configuration diagram of a unit cooler in an embodiment of the present invention. [Figure 2] It is a view taken in the direction of arrow II in FIG. 1. [Figure 3] It is a plan view of the heat exchanger in an embodiment of the present invention as viewed from the horizontal direction. [Figure 4] It is a cross-sectional view taken along line IV-IV in FIG. 3. [Figure 5] It is a perspective view of the blow-off hood and the damper in an embodiment of the present invention as viewed from the fan side, showing the closed state of the damper. [Figure 6] It is a perspective view of the blow-off hood and the damper in an embodiment of the present invention as viewed from the fan side, showing the open state of the damper.

Mode for Carrying Out the Invention

[0023] Next, embodiments of the present invention will be described based on the drawings.

[0024] <Unit Cooler> Figure 1 is a schematic diagram of the unit cooler 1. Figure 1 corresponds to a plan view of the unit cooler 1. Figure 2 is a view taken along arrow II in Figure 1. As shown in Figures 1 and 2, the unit cooler 1 is installed in warehouse F and blows cool air into warehouse F. The unit cooler 1 comprises a housing 2, an intake port 3 and an outlet port 4 provided in the housing 2, an outlet hood 10 provided in the outlet port 4, a fan 5 provided in the outlet hood 10, a heat exchanger 6 provided inside the housing 2, a defrosting device 7 for defrosting the heat exchanger 6, and a damper (door) 8 for opening and closing the outlet port 4. Hereinafter, the vertical and horizontal directions refer to the state with the unit cooler 1 installed in warehouse F.

[0025] <Enclosure> The housing 2 is formed in the shape of a rectangular box. Of the two horizontally opposing sides 2a and 2b (first side 2a and second side 2b) of the housing 2, the intake port 3 is formed on the first side 2a. Of the two sides 2a and 2b, the outlet port 4 is formed on the second side 2b. The inside and outside of the housing 2 are in communication through these intake port 3 and outlet port 4. A suction hood 9, formed in a rectangular cylindrical shape, is provided on the first side surface 2a, surrounding the suction port 3. The suction hood 9 protrudes outward, extending diagonally downward from the first side surface 2a. An opening 9a is formed on the lower surface of the suction hood 9 opposite to the suction port 3.

[0026] A cylindrical discharge hood 10 is provided on the second side surface 2b, surrounding the outlet 4. The discharge hood 10 protrudes outward, extending diagonally upward from the second side surface 2b. An opening 10a is formed on the side of the discharge hood 10 opposite the outlet 4. A fan 5 is also provided on the discharge hood 10. In this embodiment, as shown in Figure 2, two discharge hoods 10 are provided side by side horizontally, and a fan 5 is provided on each discharge hood 10.

[0027] <Fan> The two fans 5 have identical configurations. Therefore, only one of the two fans 5 will be described below. The other fan 5 will be given the same reference numeral as the other fan 5 and its description will be omitted. The fan 5 comprises a fan motor 13 and fan blades 14 attached to the fan motor 13. The fan motor 13 is connected to a control unit (not shown).

[0028] When the control unit rotates the fan motor 13 in the forward direction, a negative pressure is created on the housing 2 side relative to the fan motor 13. As a result, air from inside the warehouse F is drawn into the housing 2 via the intake hood 9 and intake port 3, and then passes through the housing 2. After that, the air is blown out of the housing 2 via the outlet port 4 and discharge hood 10 (see arrow W1 in Figure 1). Hereafter, this airflow will be referred to as the forward airflow W1. When the control unit reverses the rotation of the fan motor 13, the pressure on the housing 2 side becomes positive relative to the fan motor 13. As a result, air from inside the warehouse F is drawn into the housing 2 via the discharge hood 10 and the discharge port 4, and then passes through the housing 2. After that, the air is blown out of the housing 2 via the intake port 3 (see arrow W2 in Figure 1). Hereafter, this airflow will be referred to as the reverse wind W2. The rotational speed when the fan motor 13 is reversed is lower than the rotational speed when the fan motor 13 is rotating forward.

[0029] <Heat exchanger> Figure 3 is a plan view of the heat exchanger 6 as seen from the horizontal. Figure 4 is a cross-sectional view along the line IV-IV in Figure 3. As shown in Figures 1, 3, and 4, the heat exchanger 6 is connected to a refrigeration unit 16 equipped with a compressor (not shown) via a connecting refrigerant flow path 15. The heat exchanger 6, together with the connecting refrigerant flow path 15 and the refrigeration unit 16, constitutes a refrigeration cycle in which the refrigerant is circulated and functions as an evaporator. In other words, the heat exchanger 6 exchanges heat with the air inside the housing 2 (inside the warehouse F) to generate cold air.

[0030] The heat exchanger 6 comprises a fin module 80 and a refrigerant flow path 81 fixed to the fin module 80. The refrigerant flow path 81 is connected to a connecting refrigerant flow path 15. Refrigerant circulates through each of the refrigerant flow paths 15 and 81. The heat exchanger 6 is a so-called full-liquid type heat exchanger. A full-liquid type heat exchanger 6 performs heat exchange between liquid-phase refrigerant and air when a predetermined amount of liquid-phase refrigerant is filled in the refrigerant flow path 81.

[0031] The fin module 80 comprises a plurality of fins 90. Each fin 90 is made of a material with excellent thermal conductivity, such as aluminum. Each fin 90 is formed in the shape of a thin plate with the horizontal direction as the thickness direction. Each fin 90 is arranged with spacing in the horizontal direction. Air passes between adjacent fins 90. Hereinafter, the direction in which each fin 90 is arranged will be referred to as the X direction. The direction that is horizontal and intersects the X direction will be referred to as the Y direction.

[0032] Each fin 90 has a first refrigerant pore row 91, a second refrigerant pore row 92, and a warm brine pore row 93. In each fin 90, the corresponding refrigerant pore rows 91 and 92 and the warm brine pore rows 93 overlap each other when viewed from the X direction. Therefore, in the following description, the details of the refrigerant pore rows 91 and 92 and the warm brine pore row 93 will be explained using one fin 90 as an example.

[0033] The first refrigerant hole rows 91 and the second refrigerant hole rows 92 are used to perform the function of a heat exchanger 6. The first refrigerant hole rows 91 and the second refrigerant hole rows 92 are arranged alternately with spacing between them in the Y direction. Adjacent first refrigerant hole rows 91 and second refrigerant hole rows 92 constitute a set of refrigerant hole groups 94. That is, multiple refrigerant hole groups 94 are arranged in the Y direction.

[0034] The row of holes 93 for warm brine is used to function as a defrosting device 7. The row of holes 93 for warm brine is provided between adjacent rows of first refrigerant holes 91 and second refrigerant holes 92 that constitute a single refrigerant hole set 94. In this case, the row of holes 93 for warm brine is not provided between adjacent rows of refrigerant holes 94. However, it is not limited to this, and the row of holes 93 for warm brine may be provided alternately with respect to all refrigerant hole sets 91 and 92.

[0035] The first refrigerant hole row 91 comprises a plurality of first refrigerant holes 95. The plurality of first refrigerant holes 95 are arranged in a straight line with spacing in the vertical direction. Each first refrigerant hole 95 penetrates the fin 90 in the X direction. Each first refrigerant hole 95 is a round hole formed with the same outer diameter D1. The plurality of first refrigerant holes 95 constituting the first refrigerant hole row 91 are arranged at equal intervals.

[0036] The second refrigerant hole row 92 comprises a plurality of second refrigerant holes 96. The plurality of second refrigerant holes 96 are arranged in a straight line with spacing in the vertical direction. Each second refrigerant hole 96 penetrates the fin 90 in the X direction. Each second refrigerant hole 96 is a round hole formed with an outer diameter D1 equivalent to that of each first refrigerant hole 95. The plurality of second refrigerant holes 96 constituting the second refrigerant hole row 92 are arranged at equal intervals. The shape of each refrigerant hole 95,96 is not limited to a perfect circle, but can be changed as appropriate to an elliptical shape, etc.

[0037] In the first row of refrigerant holes 91 and the second row of refrigerant holes 92 that constitute a single refrigerant hole set 94, the first refrigerant holes 95 and the second refrigerant holes 96 are arranged with a half-pitch offset in the vertical direction. Specifically, the arrangement pitch of the first refrigerant holes 95 (the distance between adjacent first refrigerant holes 95 in the vertical direction) and the arrangement pitch of the second refrigerant holes 96 (the distance between adjacent second refrigerant holes 96 in the vertical direction) are equal. Furthermore, in the first row of refrigerant holes 91 and the second row of refrigerant holes 92 that constitute a single refrigerant hole set 94, the first refrigerant holes 95 and the second refrigerant holes 96 are arranged in a staggered (alternating) pattern when viewed from the X direction. However, the arrangement pitch of the multiple refrigerant holes 95 and 96 that constitute each refrigerant hole set 91 and 92 can be changed as appropriate.

[0038] The row of warm brine holes 93 comprises a plurality of warm brine holes 105. The plurality of warm brine holes 105 are arranged in a straight line with spacing in the vertical direction. Each warm brine hole 105 penetrates the fin 90 in the X direction. Each warm brine hole 105 is a round hole formed with an outer diameter D2 smaller than the outer diameter D1 of the refrigerant holes 95, 96. The outer diameter D1 is set to, for example, 15.88 mm. The outer diameter D2 is set to, for example, 12.70 mm. It is preferable that both outer diameters D1 and D2 are set within the range of 9 mm to 16 mm. The shape of the hot brine hole 105 is not limited to a perfect circle; it can be changed as appropriate to an elliptical shape, etc. In this case, the opening area of ​​the hot brine hole 105 should be smaller than the opening area of ​​the refrigerant holes 95 and 96. Also, the hot brine hole 105 and the refrigerant holes 95 and 96 do not necessarily have similar shapes.

[0039] Each of the warm brine holes 105 constituting a row of warm brine holes 93 is arranged at equal intervals. The arrangement pitch of each warm brine hole 105 is greater than the arrangement pitch of the refrigerant holes 95 and 96. That is, the number of warm brine holes 105 constituting a row of warm brine holes 93 is less than the number of refrigerant holes 95 and 96 constituting refrigerant hole rows 91 and 92. The warm brine holes 105 are located between vertically adjacent first refrigerant holes 95 in the first refrigerant hole row 91, and between vertically adjacent second refrigerant holes 96 in the second refrigerant hole row 92. Therefore, each warm brine hole 105 is surrounded by four refrigerant holes 95 and 96.

[0040] The refrigerant flow path 81 is equipped with two coils 110, 111 (first coil 110 and second coil 111) for each row of refrigerant holes 91, 92. Each coil 110, 111 is a tubular material (heat transfer tube) having an outer diameter that can be pressed into each refrigerant hole 95, 96. In the following, the coils 110, 111 provided in the first row of refrigerant holes 91 will be used as an example to explain the details of the coils 110, 111, and the second row of refrigerant holes 92 will be given the same reference numerals as the coils 110, 111 provided in the first row of refrigerant holes 91 and its explanation will be omitted.

[0041] Each coil 110, 111 penetrates the refrigerant holes 95 facing each other in the X direction between adjacent fins 90, and extends upward in a meandering manner in the X direction by being folded back on both sides in the X direction relative to the fin module 80. The lower and upper ends of each coil 110, 111 are connected to the connecting refrigerant flow path 15. Each coil 110, 111 extends parallel to the same first row of refrigerant holes 91, forming a so-called double circuit structure (parallel structure).

[0042] As shown in Figure 3, the first coil 110 comprises a first straight section 110a, a second straight section 110b, a first folded section 110c, and a second folded section 110d. The second coil 111 includes a third straight section 111a, a fourth straight section 111b, a third folded section 111c, and a fourth folded section 111d.

[0043] The first straight section 110a is assembled in a state where it is in contact with the inner periphery of the first through-hole 95a by being press-fitted into the first through-hole 95a of the first refrigerant hole 95. The first straight section 110a is provided between adjacent fins 90 so as to penetrate each of the first through-holes 95a that are facing each other in the X direction. The second straight section 110b is assembled in a state where it is in contact with the inner periphery of the second through-hole 95b by press-fitting it into the second through-hole 95b which is adjacent to the first through-hole 95a above the first refrigerant hole 95. The second straight section 110b is provided so as to penetrate each of the second through-holes 95b that are facing each other in the X direction between adjacent fins 90.

[0044] The third straight section 111a is assembled in a state where it is in contact with the inner periphery of the third through-hole 95c by press-fitting it into the third through-hole 95c, which is adjacent to the second through-hole 95b above the first refrigerant hole 95. The third straight section 111a is provided between adjacent fins 90 so as to penetrate each of the third through-holes 95c that are facing each other in the X direction. The fourth straight section 111b is assembled in a state where it is in contact with the inner periphery of the fourth through-hole 95d by press-fitting it into the fourth through-hole 95d, which is adjacent to the third through-hole 95c above among the first refrigerant holes 95. The fourth straight section 111b is provided so as to penetrate each of the fourth through-holes 95d that are facing each other in the X direction between adjacent fins 90.

[0045] The first refrigerant holes 95 consist of two through-holes (first through-hole 95a and second through-hole 95b) through which the first coil 110 (first straight section 110a and second straight section 110b) passes, and two through-holes (third through-hole 95c and fourth through-hole 95d) through which the second coil 111 (third straight section 111a and fourth straight section 111b) passes, arranged alternately. In the following description, the first through-hole 95a and second through-hole 95b will be referred to as the first hole set 115, and the third through-hole 95c and fourth through-hole 95d will be referred to as the second hole set 116. In this case, the first refrigerant hole row 91 will consist of the first hole set 115 and the second hole set 116 arranged alternately in the vertical direction.

[0046] The first folded portion 110c is provided on one side in the X direction relative to the fin module 80. The first folded portion 110c connects the X-direction ends of the first straight portion 110a and the second straight portion 110b, which are provided in the same first hole set 115. The second folded portion 110d is provided on the other side in the X direction relative to the fin module 80. The second folded portion 110d connects the other end in the X direction of the second straight portion 110b provided on one first hole set 115 and the first straight portion 110a provided on another first hole set 115 located, for example, above the first first hole set 115.

[0047] The third folded portion 111c is provided on one side in the X direction relative to the fin module 80. The third folded portion 111c connects the X-side ends of the third straight portion 111a provided in one second hole set 116 and the fourth straight portion 111b provided in another second hole set 116 located, for example, below the first second hole set 116. In the illustrated example, the third folded portion 111c wraps around the outside of the first folded portion 110c.

[0048] The fourth folded portion 111d is provided on the other side in the X direction relative to the fin module 80. The fourth folded portion 111d connects the other ends in the X direction of the third straight portion 111a and the fourth straight portion 111b, which are provided in the same second hole set 116. In the illustrated example, the second folded portion 110c wraps around the outside of the fourth folded portion 111d.

[0049] <Defrosting device> The defrosting device 7 comprises a hot brine channel 82 fixed to the fin module 80 of the heat exchanger 6, and a defrosting device body 18 connected to the hot brine channel 82 via a brine circulation channel 17. Brine (antifreeze) used for defrosting the heat exchanger 6 flows through the warm brine channel 82. In this embodiment, the brine used is a material with a freezing point lower than the triple point of carbon dioxide, such as an HCFO-based brine.

[0050] The warm brine channel 82 extends upward in a meandering manner in the X direction, passing through opposing warm brine holes 105 in the X direction between adjacent fins 90, and being folded back on both sides in the X direction relative to the fin module 80. Specifically, the warm brine channel 82 comprises a straight section 82a, a folded-back section 82b on one side, and a folded-back section 82c on the other side.

[0051] The straight section 82a is assembled in contact with the inner periphery of the warm brine hole 105 by press-fitting it into the warm brine hole 105 or the like. The straight section 82a is provided between adjacent fins 90 so as to penetrate the warm brine holes 105 that are opposite each other in the X direction. The one-sided folded portion 82b is provided on one side in the X direction relative to the fin module 80. The one-sided folded portion 82b connects the one-sided ends in the X direction of one straight portion 82a and a straight portion 82a located above the first straight portion 82a. In the illustrated example, the one-sided folded portion 82b is provided so as to straddle the second hole set 116 in the vertical direction.

[0052] The other-side folded portion 82c is provided on the other side in the X direction relative to the fin module 80. The one-side folded portion 82c connects the other end in the X direction of one straight portion 82a and a straight portion 82a located, for example, below the first straight portion 82a. In the illustrated example, the other-side folded portion 82c is provided so as to straddle the first hole set 115 in the vertical direction. The defrosting device body 18 circulates brine between itself and the heat exchanger 6 when defrosting the heat exchanger 6.

[0053] <Dampa> Figures 5 and 6 are perspective views of the damper 8 installed at the air outlet 4, as seen from the fan 5 side. Figure 5 shows the damper 8 in the closed state. Figure 6 shows the damper 8 in the open state. As shown in Figures 5 and 6, the air outlet 4 is formed in a circular shape in plan view, and a damper 8 is provided to correspond to this shape of air outlet 4. More specifically, the damper 8 comprises a support shaft 21 that passes through the radial center of the air outlet 4 and extends radially, two door bodies 22 that are rotatably supported on the support shaft 21, and a rod-shaped stopper 23 arranged parallel to the support shaft 21.

[0054] The stopper 23 is positioned offset to the inside of the housing 2 (opposite side from the fan 5) compared to the support shaft 21. The stopper 23 also extends in the same direction as the support shaft 21. Each door body 22 is formed in a semicircular shape by dividing the circular shape corresponding to the air outlet 4 in half with the stopper 23 (support shaft 21) as the center. In other words, each door body 22 is formed symmetrically with respect to the stopper 23. Each door body 22 has a flat portion 22a along the stopper 23 and an arc portion 22b along the inner circumferential surface of the air outlet 4.

[0055] Each door body 22 is rotatably supported on the support shaft 21 via a plurality of brackets 24 (for example, three in this embodiment) provided along the flat portion 22a. This allows the air outlet 4 to be opened and closed by each door body 22. When each door body 22 is blocking the air outlet 4, each door body 22 is positioned offset inward from the support shaft 21 within the housing 2. In this state, each door body 22 and the stopper 23 are located on the same plane. This state is referred to as the blocked state (see Figure 5). Therefore, in the blocked state, the brackets 24 abut against the stoppers 23, and each door body 22 does not rotate further inward within the housing 2 than in the blocked state.

[0056] In contrast, each door body 22 is permitted to rotate toward the fan 5 side (towards the opening 10a of the outlet hood 10). Thus, as shown in Figure 6, the state in which each door body 22 is rotated so as to fold toward the fan 5 side is referred to as the open state.

[0057] <Operation of the unit cooler> Next, we will explain the operation of Unit Cooler 1. First, let's explain the cooling operation for cooling the inside of warehouse F. In this case, the refrigeration unit 16 is started and the defrosting device 7 is stopped. Then, a control unit (not shown) rotates the fan motor 13 in the forward direction, causing a forward airflow W1 to flow into the housing 2. The forward airflow W1 pushes the door body 22 of the damper 8 to the open side, opening it (see Figure 6). At this time, the cold air generated by the heat exchanger 6 as the refrigeration unit 16 is driven is blown out of the housing 2 through the outlet 4. As a result, the inside of warehouse F is cooled. The temperature inside warehouse F is below -40°C. In this way, when the favorable airflow W1 is present, cold air is blown into the warehouse F. The fan 5 is positioned downstream of the damper 8 (door body 22) in the favorable airflow W1.

[0058] Next, we will explain the defrosting operation for defrosting the heat exchanger 6. In this case, the refrigeration unit 16 is stopped and the defrosting device 7 is started. At this time, the brine circulated between the defrosting device body 18 and the heat exchanger 6 is heated to a temperature higher than the temperature of the refrigerant used in the refrigeration cycle (for example, about 25°C) by the defrosting device body 18. The brine is then supplied to the heat exchanger 6 (warm brine flow path 82) as so-called warm brine. The brine used for defrosting in the heat exchanger 6 is returned to the defrosting device body 18. By repeating this process, the heat exchanger 6 is defrosted.

[0059] More specifically, the defrosting of the heat exchanger 6 is performed by heating the heat exchanger 6 as the warm brine, heated to a desired temperature in the defrosting device body 18, passes through the heat exchanger 6. At this time, the warm brine flowing into the warm brine channel 82 flows upward while meandering in the X direction. The heat from the warm brine flowing through the warm brine channel 82 heats the warm brine channel 82 and the fins 90, etc. This melts the frost adhering to the warm brine channel 82 and the fins 90, etc., and defrosting is performed. The water generated by defrosting falls through the gaps between adjacent fins 90. This promotes the defrosting of the heat exchanger 6.

[0060] Here, the row of holes 93 for the warm brine is arranged alternately with the rows of holes 91 and 92 for the refrigerant that constitute the refrigerant hole set 94, so that the warm brine channel 82 and the refrigerant channel 81 are located in close proximity. Therefore, the heat of the warm brine flowing through the warm brine channel 82 is also transferred to the refrigerant channels 81 which are located on both sides of the warm brine channel 82 in the Y direction. Consequently, the refrigerant flowing through the refrigerant channel 81 is heated by the warm brine. In this case, for example, the latent heat of the refrigerant channel 81 and fins 90 can be used to heat the refrigerant channel 81 and the fins 90 when the liquid phase refrigerant flowing through the refrigerant channel 81 evaporates and then condenses again.

[0061] This allows frost adhering to the area surrounding the refrigerant flow path 81 to be melted using the latent heat of condensation of the refrigerant. As a result, the desired defrosting performance can be easily achieved while keeping the brine temperature relatively low. Therefore, evaporation of moisture present around the refrigerant flow path 81 due to the heat of the brine is suppressed, and frost formation in areas other than the heat exchanger 6 can be suppressed. This defrosting operation is terminated after the defrosting device body 18 has been operated for a predetermined time.

[0062] During defrosting, the heat exchanger 6 is heated. To prevent this heat from escaping to the outside of the housing 2, the outlet 4 is closed by the damper 8. However, there may be cases where, for example, frost has accumulated on the door body 22 and the outlet 4 cannot be completely closed by the damper 8. In such cases, the unit cooler 1 reverses the fan motor 13 using a control unit (not shown) to create a reverse airflow W2 into the housing 2. This reverse airflow W2 pushes the door body 22 of the damper 8 towards the closing side, resulting in a completely closed state (see Figure 5).

[0063] As described above, the unit cooler 1 is equipped with a damper 8 at the outlet 4, which opens and closes the outlet 4. The damper 8 opens the outlet 4 during cooling operation, allowing cold air to be blown out from the outlet 4. On the other hand, when the defrosting device 7 is started, the fan 5 is reversed, and the resulting backflow W2 is used by the damper 8 to completely close the outlet 4. Therefore, when defrosting the heat exchanger 6, the damper 8 can be forcibly closed by the fan 5. As a result, there is no need to provide a heater or the like in the damper 8 as in conventional systems, and the equipment cost of the unit cooler 1 can be reduced.

[0064] The rotational speed of the fan motor 13 when it is reversed is lower than the rotational speed when it is rotated forward. The fan motor 13 rotates forward during cooling operation and reverses during defrosting operation. In other words, the rotational speed of the fan motor 13 when it is reversed is lower than the rotational speed when it is rotated forward, which means that the rotational speed of the fan 5 when the defrosting device 7 is started is lower than the rotational speed of the fan 5 when cold air is blown into the warehouse F. This configuration prevents the backwind W2 from becoming stronger than necessary. As a result, the impact when the damper 8 is closed can be minimized, and damage to various parts of the unit cooler 1 (such as bearings not shown) can be prevented.

[0065] By reducing the rotational speed when reversing the fan motor 13, the torque of the fan motor 13 can be increased. This prevents, for example, the fan 5 from locking up due to frost buildup. By changing the rotation speed in accordance with the forward and reverse rotation of fan 5, it is possible to prevent excessive power consumption. This also makes it possible to reduce the running costs of unit cooler 1.

[0066] Fan 5 is positioned on the opening 10a side of the discharge hood 10. That is, when a forward airflow W1 is generated (when cold air is being blown into the warehouse F), fan 5 is positioned downstream of damper 8. This allows fan 5 to be positioned as far away from the defrosting device 7 and heat exchanger 6 as possible. This prevents steam generated during defrosting from adhering to fan 5 and freezing on fan 5. Thus, fan 5 can be operated stably.

[0067] The temperature range inside warehouse F is below -40°C. By providing the above configuration to the unit cooler 1, which is used at extremely low temperatures below -40°C where the risk of damper 8 freezing is high, it is possible to effectively prevent heat from leaking into the warehouse during defrosting. In other words, even when defrosting is started, it is possible to prevent steam from leaking into warehouse F or the inside of warehouse F from being heated, and to efficiently maintain the temperature range of warehouse F. Defrosting is performed using heated brine. Therefore, compared to conventional methods that use heaters, defrosting with warm brine at a lower heating temperature prevents the heat generated during defrosting from leaking into the warehouse.

[0068] The heat exchanger 6 has a plurality of fins 90, each with refrigerant holes (first through-holes) 95, 96 and warm brine holes (second through-holes) 105 formed at positions offset from each other when viewed from the X direction (first direction). The fin module 80 is provided with a refrigerant flow path 81 and a warm brine flow path 82, respectively, which penetrate the corresponding refrigerant holes 95, 96 of the plurality of fins 90 in the X direction. The outer diameter of the warm brine flow path 82 is smaller than the outer diameter of the refrigerant flow path 81.

[0069] Therefore, when frost forms on the heat exchanger 6, the heat from the warm brine is transferred to the fins 90, etc., by flowing brine through the warm brine channel 82. This allows the heat exchanger 6 to be defrosted. In addition, since the warm brine channel 82 penetrates the warm brine hole 105, the outer surface of the warm brine channel 82 comes into contact with the inner edge of the warm brine hole 105. This allows the heat from the warm brine channel 82 (warm brine) to be efficiently transferred to the fins 90.

[0070] As a result, the desired defrosting performance can be achieved while making the outer diameter of the warm brine channel 82 smaller than the outer diameter of the refrigerant channel 81. Furthermore, by making the outer diameter D2 of the warm brine channel 82 smaller than the outer diameter D1 of the refrigerant channel 81, the flow rate of warm brine flowing through the warm brine channel 82 can be reduced, thus providing a heat exchanger 6 with reduced equipment costs. By making the outer diameter D2 of the warm brine channel 82 smaller than the outer diameter D1 of the refrigerant channel 81, the increase in size of the heat exchanger 6 that would be required to provide the warm brine channel 82 can also be suppressed.

[0071] The present invention is not limited to the embodiments described above, but includes various modifications to the embodiments described above, without departing from the spirit of the invention. For example, in the embodiment described above, the damper 8 was described as comprising a support shaft 21 that passes through the radial center of the outlet 4 and extends radially, two door bodies 22 that are rotatably supported on the support shaft 21, and a rod-shaped stopper 23 arranged parallel to the support shaft 21. However, it is not limited to this, and the damper 8 only needs to be configured to open the outlet 4 when it receives a forward airflow W1 and to close the outlet 4 when it receives a reverse airflow W2.

[0072] In the above-described embodiment, the case in which each outlet hood 10 is provided with one fan 5 was explained. However, the number of fans 5 is not limited to this, and can be determined arbitrarily. In the above-described embodiment, a configuration was described in which the refrigerant holes 95, 96 and the warm brine holes 105 are arranged alternately in the vertical direction. However, the configuration is not limited to this, and the refrigerant holes 95, 96 and the warm brine holes 105 may be arranged at the same position in the vertical direction.

[0073] In the above-described embodiment, a configuration was described in which the refrigerant holes 95, 96 and the warm brine holes 105 are at different positions in the Y direction and are arranged vertically. However, the configuration is not limited to this, and the refrigerant holes 95, 96 and the warm brine holes 105 may be at the same position in the Y direction and, for example, arranged alternately vertically.

[0074] In the above-described embodiment, a heat exchanger 6 with a so-called double-circuit structure, in which two coils 110 and 111 extend in parallel to one row of refrigerant holes 91 and 92, was explained as an example. However, the heat exchanger 6 is not limited to this, and may have a configuration in which one coil extends to one row of refrigerant holes 91 and 92, or a configuration in which three or more coils extend. However, compared to a configuration in which one coil extends, a configuration in which multiple coils 110 and 111 extend to one row of refrigerant holes 91 and 92, such as a double-circuit structure, makes it easier to reduce pressure loss because the length of each coil 110 and 111 can be reduced and the number of places where folded sections are formed can be reduced.

[0075] In the above-described embodiment, the refrigerant flow path 81 and the warm brine flow path 82 are assembled into the corresponding holes by press-fitting or the like, and are in direct contact with the inner periphery of each hole. However, the invention is not limited to this, and the refrigerant flow path 81 and the warm brine flow path 82 may be in contact with the inner periphery of the corresponding hole via an intermediate member such as an adhesive. The refrigerant flow path 81 and the warm brine flow path 82 only need to be in contact with at least a portion of the inner periphery of the corresponding hole. In the above-described embodiment, the heat exchanger 6 was described as a so-called liquid-filled heat exchanger 6. However, it is not limited to this, and the heat exchanger 6 may also be a dry type.

[0076] The above-described embodiment describes a configuration in which defrosting is performed by brine. However, it is not limited to this, and defrosting may also be performed by using a separate heater or by spraying brine or water onto the heat exchanger 6. [Explanation of Symbols]

[0077] 1…Unit cooler 2…Cabinet 3... Inlet 4…Air outlet 5…fan 6...Heat exchanger 7…Defrosting device 8...Damper (door) 22... Door body (door) 80... Fin Module 81... Refrigerant flow path 82...Warm brine channel 90... Finn 95...First refrigerant hole (first through hole) 96...Second refrigerant hole (first through hole) 105…Hot brine hole (second through hole) F...Frozen and refrigerated warehouse W1…Shunfu W2…Headwind

Claims

1. A unit cooler installed in a refrigerated warehouse, The casing and The housing includes an intake port and an outlet port, A discharge hood provided at the aforementioned outlet, A fan is provided in the aforementioned blowing hood, which draws air from inside the refrigerated warehouse into the housing through the intake port and blows the air into the refrigerated warehouse through the outlet, A heat exchanger provided within the housing cools the air drawn into the housing and generates cold air, A defrosting device for defrosting the heat exchanger, A door is provided at the aforementioned outlet so as to be openable and closable, and is opened during the cooling operation of the refrigerated warehouse to allow the cold air to be blown out from the outlet, Equipped with, When the defrosting device is started, the fan is reversed to generate a backflow, which causes the door to block the air outlet. A unit cooler characterized by the following features.

2. The rotational speed of the fan when the defrosting device is started is lower than the rotational speed of the fan when the cold air is blown into the refrigerated warehouse. The unit cooler according to feature 1.

3. When the cold air is blown into the cold storage warehouse, the fan is positioned downstream of the door from the cold air. A unit cooler according to claim 1 or 2, characterized by the above.

4. The temperature range of the aforementioned refrigerated warehouse is below -40°C. A unit cooler according to claim 1 or 2, characterized by the above.

5. The defrosting is carried out using heated warm brine. A unit cooler according to claim 1 or 2, characterized by the above.

6. The heat exchanger is, A fin module having a plurality of fins, each having a first through-hole and a second through-hole formed at positions offset from each other when viewed from a first direction, and the plurality of fins being arranged with spacing in the first direction, Of the plurality of fins, each of the first through-holes is provided in the fin module so as to penetrate in the first direction, and a refrigerant flow path is provided through which the refrigerant flows, The fin module is provided with a hot brine channel through which the hot brine flows, with each of the plurality of fins having a second through-hole that penetrates in the first direction, The outer diameter of the aforementioned warm brine channel is smaller than the outer diameter of the aforementioned refrigerant channel. The unit cooler according to feature 5.

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