Unit cooler

Abstract

To provide a unit cooler which prevents radiation of heat generated during defrosting and can effectively achieve defrosting effect.SOLUTION: A unit cooler includes: a fan module having a fan; a housing which encloses a heat exchanger; and a damper unit. The housing has: a first chamber which houses the heat exchanger; a second chamber which is disposed above the first chamber and leads to the fan module; and a partition wall formed between the first chamber and the second chamber. The partition wall includes an opening allowing the first chamber and the second chamber to communicate with each other. The damper unit has blades which open the opening when the fan rotates and close the opening when the fan is at rest.SELECTED DRAWING: Figure 1

Description

[Technical Field]

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

[0002] A unit cooler that supplies cold air to a large freezer or the like is configured to take in outside air from outside the housing, cool it through a heat exchanger inside the housing, and supply the cold air to the freezer. In such a unit cooler, when moisture contained in the outside air is cooled, it can adhere to the surfaces of the heat exchanger fins and other components as frost or ice.

[0003] Therefore, in order to remove frost that has accumulated on the heat exchanger, defrosting is performed periodically in the unit cooler. Patent Document 1 discloses a unit cooler with a defrosting mechanism. Examples of mechanisms that achieve defrosting include a heater and a hot gas supply system. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 11-257826 Summary of the Invention [Problem to be solved by the invention]

[0005] In the unit cooler of Patent Document 1, during defrosting, the damper closes the cooling air outlet, preventing hot air from the heater or hot gas inside the unit cooler from flowing through the outlet into the freezer.

[0006] On the other hand, even during defrosting, the temperature outside the unit cooler is maintained at a low temperature of 0°C to -60°C. Therefore, in order to maximize the effect of defrosting, it is necessary to devise a way to prevent the heat generated during defrosting from dissipating outside the unit cooler as much as possible. However, the unit cooler in Patent Document 1 does not have sufficient measures in place.

[0007] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a unit cooler that can prevent the dissipation of heat generated during defrosting and effectively exert the defrosting effect. [Means for solving the problem]

[0008] In order to achieve the above object, the unit cooler of the present invention comprises: a fan module having a fan; a housing enclosing the heat exchanger; a damper unit; the housing includes a first chamber that houses the heat exchanger, a second chamber that is disposed above the first chamber and is connected to the fan module, and a partition wall that is formed between the first chamber and the second chamber; the partition wall has an opening that communicates the first chamber with the second chamber, The damper unit has a blade that opens the opening when the fan is rotating and closes the opening when the fan is stationary. [Effects of the Invention]

[0009] According to the present invention, it is possible to provide a unit cooler that can prevent the dissipation of heat generated during defrosting and effectively exert the defrosting effect. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a front cross-sectional view showing an outline of a unit cooler according to an embodiment of the present invention. [Figure 2] FIG. 2 is a side view of the unit cooler of FIG. 1 taken along the line AA. [Figure 3] FIG. 3 is a view of the damper unit as seen from the front side of the unit cooler. [Figure 4] FIG. 4 is a plan view of the damper unit. [Figure 5] FIG. 5 is a perspective view schematically showing the damper unit. [Figure 6] FIG. 6 is a perspective view schematically showing the damper unit. [Figure 7] FIG. 7 is an enlarged view of the second side chamber shown in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0011] In this specification, "upward" and "downward" mean upward in the direction of gravitational acceleration (or anti-gravity direction) and downward in the direction of gravitational acceleration (or gravity direction), respectively. In addition, the drawings show outlines of each part and may not represent actual dimensions or proportions.

[0012] (Unit cooler configuration) Fig. 1 is a front cross-sectional view showing an outline of a unit cooler 10 according to an embodiment of the present invention, with piping and a heater being shown schematically. Fig. 2 is a side view of the AA cross section of the unit cooler 10 in Fig. 1. The left-right direction in Fig. 1 corresponds to the longitudinal direction of the housing and the drain pan, and the left-right direction in Fig. 2 corresponds to the width direction of the housing and the drain pan.

[0013] In the figure, the unit cooler 10 comprises a housing 12, a heat exchanger 20 enclosed by the housing 12, two duct fan modules 30 as fan modules attached to the ceiling wall 12e of the housing 12, and a drain pan 40 arranged below the housing 12.

[0014] Each duct fan module 30 has a substantially cylindrical duct 31, a motor disposed within the duct 31, and a fan driven by the motor. The lower end of the duct 31 is connected to the periphery of a circular air outlet 12g formed in the ceiling wall 12e. Note that instead of the duct fan module 30, a fan module in which a fan is fixed to the ceiling wall 12e without a duct may be used.

[0015] The housing 12 has side walls 12b and 12c installed at both ends in the longitudinal direction, a front wall 12a, a rear wall 12d, and a ceiling wall 12e, which are joined together by welding, etc. A plurality of (six in this example) support legs 17 are attached to the front wall 12a and the rear wall 12d, and the lower ends of the support legs 17 are connected to the drain pan 40, thereby supporting the housing 12 with respect to the drain pan 40.

[0016] A heat exchanger 20 is disposed within the metal housing 12. The heat exchanger 20 has a number of fins arranged in parallel at a predetermined pitch along the longitudinal direction and a pipe (piping) 21 (see FIG. 7) that penetrates the fins in the fin arrangement direction. The pipe (piping) 21 passes through the entire fin, then turns back and passes through the fins again. A defrosting heater 22 is disposed parallel to the pipe 21 and penetrates the fins. Although FIG. 1 shows one heater 22, in practice, multiple heaters 22 are installed in parallel. The heater 22 is preferably a sheathed heater, for example. The underside of the heat exchanger 20 is exposed to the space between the housing 12 and the drain pan 40 (which is connected to the space outside the unit cooler 10).

[0017] Horizontal partition walls 12f are disposed below ceiling wall 12e and above heat exchanger 20, with a gap therebetween, and the outer periphery of horizontal partition wall 12f is connected to side walls 12b, 12c, front wall 12a, and rear wall 12d along the entire periphery. Horizontal partition wall 12f divides the space within housing 12 into a lower space LS where heat exchanger 20 is disposed, and an upper space (second chamber) US between ceiling wall 12e and horizontal partition wall 12f.

[0018] An inspection hatch 12m is provided on the rear wall 12d (and the front wall 12a) facing the upper space US, and is shielded by an inspection door.

[0019] Below each duct fan module 30, a pair of rectangular openings 12h, 12h is formed in the horizontal partition wall 12f, with a horizontal beam 12i between the pair of rectangular openings 12h. A damper unit 50 is attached to each horizontal beam 12i. The opening ratio of the rectangular openings 12h can be expressed as equal to or greater than the inner diameter of the fan, and the opening ratio is preferably 1.0 to 1.5 times the inner diameter of the fan.

[0020] Fig. 3 is a view of the damper unit 50 as seen from the front side of the unit cooler 10. Fig. 4 is a plan view of the damper unit 50, with the rectangular opening 12h indicated by a dotted line. Figs. 5 and 6 are perspective views schematically showing the damper unit 50.

[0021] The damper unit 50 includes a pair of case-like bases 51 installed on the horizontal beams 12i, a straight pipe 52 supported at both ends by the bases 51, a pair of rectangular vanes 53 arranged above the rectangular opening 12h, a mounting bracket 54 that pivotally connects the vanes 53 to the straight pipes 52, and a stopper member 55. A heater 56 for heating the damper is inserted inside the straight pipe 52. The mounting bracket 54 is attached to the vanes 53 and forms part of them. The heater 56 is preferably a sheathed heater, for example.

[0022] A receiving plate 53a is attached to the lower surface of each of the vanes 53 in parallel with the straight pipe 52. The receiving plate 53a has a receiving surface extending in the normal direction of the vane 53. A bent portion 53b (not shown in FIGS. 5 and 6) is formed on the edge of the vane 53 other than the edge on the straight pipe 52 side.

[0023] 5 and 6, a plurality of mounting brackets 54 (three in this example) are arranged on one vane plate 53, and each mounting bracket has a base 54a attached to the center and both ends of the vane plate 53, a mounting portion 54b bent at a right angle to the base 54a, and a circular opening 54c formed in the mounting portion 54b. The straight pipe 52 passes through the circular opening 54c so as to be rotatable and slidable.

[0024] The stopper member 55 has a bottom wall 55a and side walls 55b extending upward from both sides of the bottom wall 55a. As shown in Figures 5 and 6, the stopper member 55 is installed on the base 51 after the slats 53 and the mounting brackets 54 are attached to the horizontal partition wall 12f.

[0025] The slats 53 connected to the mounting bracket 54 have an area larger than the area of ​​the rectangular opening 12h and are pivotable around the central axis of the straight pipe 52 between a closed position and a maximum open position shown in FIG. 3. When in the closed position, the slats 53 are substantially parallel to the upper surface of the horizontal partition wall 12f and are positioned around the rectangular opening 12h, thereby shielding the rectangular opening 12h. On the other hand, when the slats 53 pivot to the maximum open position, the upper edges of the mounting portions 54b of the mounting bracket 54 abut against the lower part of the stopper member 55, thereby restricting further pivoting. When the slats 53 pivot (move) to the maximum open position, the angle θ (FIG. 3) with respect to the vertical line (normal to the horizontal partition wall 12f) is preferably 20 to 40 degrees. The opening and closing structure of the vane plate 53 of the damper unit 50 is not limited to a hinge mechanism via the circular opening 54c. For example, a mechanism in which the vane plate 53 moves vertically while being guided by a vertical rail may be employed.

[0026] 1, a first vertical partition wall 12j and a second vertical partition wall 12k extend from both longitudinal ends of the heat exchanger 20 to the horizontal partition wall 12f. The lower space LS is divided into three by the first vertical partition wall 12j and the second vertical partition wall 12k, and more specifically, a central chamber (first chamber) LS0 accommodating the heat exchanger 20, a first side chamber LS1 between the first vertical partition wall 12j and the side wall 12b, and a second side chamber (third chamber) LS2 between the second vertical partition wall 12k and the side wall 12c are formed.

[0027] The central chamber LS0 communicates with the upper space US through a rectangular opening 12h, and the upper space US communicates with the outside of the unit cooler 10 through an outlet 12g, but is sealed from the outside so as not to communicate with anything else.

[0028] Fig. 7 is an enlarged view of the second side chamber LS2 shown in Fig. 1. The second side chamber LS2 is provided with a distributor 23, a header 24, and the like. The distributor 23 and the header 24 have the function of distributing and supplying the refrigerant supplied from the outside to the pipes 21. The distributor 23 and the header 24 are called a piping assembly.

[0029] A side chamber 13 is formed adjacent to the lower end of the second side chamber LS2. The side chamber (third chamber) 13 has a metal upper wall 13a that extends across the width of the housing 12 and connects the support leg 17 and the side wall 12c, a metal lateral wall 13b that extends downward from the end of the upper wall 13a on the support leg 17 side, a metal lateral wall 13c that extends downward from the end of the upper wall 13a on the side wall 12c side, and a metal lower wall 13d that connects the lower edges of the lateral walls 13b and 13c and is parallel to the upper wall 13a. The end of the side chamber 13 on the front wall 12a side and the end on the rear wall 12d side are each closed by a flat plate, except for an outlet for a heater 14, which will be described later.

[0030] Two side chamber heaters (third chamber heaters) 14 are disposed in the side chamber 13. The heaters 14 are preferably sheathed heaters and are attached to the upper wall 13a by fixing brackets (not shown). A chamber similar to the side chamber 13 may also be provided at the lower end of the first side chamber LS1.

[0031] 1, a metal drain pan 40 has a bottom wall 41 that is placed on the floor of a freezer or the like, and a peripheral wall 42 that extends in a rectangular frame shape from the periphery of the bottom wall 41. A drain pipe 44 is provided in the peripheral wall 42. A drain pan space (fourth chamber) DS that is surrounded by the bottom wall 41 and the peripheral wall 42 is formed inside the drain pan 40.

[0032] When the unit cooler 10 is viewed from above, the drain pan 40 extends beyond the housing 12 in the longitudinal direction and width direction (see FIGS. 1 and 2).

[0033] (Unit cooler operation) Next, we will explain the operation of the unit cooler 10. In Fig. 1, during cooling operation of the unit cooler 10, cooled refrigerant is introduced into the pipe 21 of the heat exchanger 20 and cools the air in the central chamber LS0 of the lower space LS via the fins.

[0034] Furthermore, when the motor of the duct fan module 30 rotates the fan, air in the upper space US is sucked in through the outlet 12g, causing the internal pressure of the upper space US to drop relative to the internal pressure of the central chamber LSO. This pressure difference causes air to flow from the central chamber LSO toward the upper space US, and this air causes the blades 53 of the damper unit 50 to pivot upward. This opens the rectangular opening 12h, allowing the cooled air in the central chamber LSO to pass through the upper space US and flow out of the unit cooler 10 through the outlet 12g, thereby cooling the inside of the freezer.

[0035] As the air in the central chamber LS0 flows into the upper space US, the air inside the freezer enters the central chamber LS0 through the space between the housing 12 and the drain pan 40, and is cooled as it passes through the heat exchanger 20.

[0036] The pivoted vane plate 53 of the damper unit 50 is restricted from pivoting beyond a predetermined angle by the stopper member 55, so that even if pulsation or the like occurs in the air passing through, vibration of the vane plate 53 is suppressed. Furthermore, since the receiving plate 53a is provided on the underside of the vane plate 53, the buoyancy of the vane plate 53 can be increased by the receiving plate 53a receiving the air flowing upward along the underside of the vane plate 53, and the rectangular opening 12h can be kept open even if the rotation speed of the fan of the duct fan module 30 is low.

[0037] When the fan of the duct fan module 30 is stopped, air in the upper space US is no longer drawn in through the outlet 12g, so the internal pressure of the central chamber LSO and the internal pressure of the upper space US become approximately equal, and the air flow through the rectangular opening 12h stops. As a result, the buoyancy of the vane plate 53 disappears, causing it to pivot downward under its own weight and come into close contact with the upper surface of the horizontal partition wall 12f. This closes the rectangular opening 12h, cutting off communication between the central chamber LSO and the upper space US.

[0038] (When defrosting) After the unit cooler 10 has been in operation for a certain period of time, frost and ice build up on the heat exchanger 20, reducing its cooling efficiency. Therefore, it is necessary to periodically defrost the unit cooler 10. Defrosting is performed by interrupting the supply of refrigerant from the outside and stopping the fan of the duct fan module 30, while energizing the heater 22 to heat the heat exchanger 20. Defrosting melts the frost and ice that has built up on the heat exchanger 20, turning it into water, which falls into the drain pan 40 and is drained through the drain pipe 44.

[0039] At this time, the heater 22 generates heat to approximately 200°C, generating mist from the heated heat exchanger 20, which rises within the central chamber LS0 along with the heated surrounding air. Meanwhile, even during defrosting, the outside of the unit cooler 10 is maintained at a low temperature of 0°C to -60°C. Therefore, if the rectangular opening 12h were left open, the mist would pass through the rectangular opening 12h and enter the upper space US, where it would freeze onto the underside of the ceiling wall 12e and the upper inner surfaces of the front wall 12a, side walls 12b and 12c, and rear wall 12d, forming ice blocks that would require removal. Furthermore, the rising mist could come into contact with the motor of the duct fan module 30, potentially causing the motor to deteriorate.

[0040] In contrast, according to this embodiment, stopping the operation of the duct fan module 30 causes the blades 53 of the damper unit 50 to close the rectangular opening 12h, so that even if mist is generated during defrosting, it cannot move from the central chamber LS0 to the upper space US. As a result, no icing occurs in the upper space US, preventing a decrease in the operating efficiency of the unit cooler 10 and reducing the burden on the operator. Furthermore, because mist generated during defrosting does not come into contact with the motor of the duct fan module 30, deterioration of the motor can be suppressed, improving the durability of the duct fan module 30.

[0041] Furthermore, according to this embodiment, when the fan of the duct fan module 30 is rotating, the vane 53 pivots to an open position where it opens the rectangular opening 12h due to the pressure of the air flowing from the central chamber LS0 to the upper space US, and when the fan comes to a standstill, it pivots to a closed position where it closes the rectangular opening 12h due to its own weight. This eliminates the need to provide the damper unit 50 with an actuator for driving the vane, thereby achieving a simple structure and reducing costs.

[0042] Furthermore, since an upper space US is formed between the ceiling wall 12e and the horizontal partition wall 12f, it functions as a heat insulating layer, preventing the horizontal partition plate 12f from being cooled too much, and even if mist adheres to the underside of the horizontal partition plate 12f, it is possible to prevent the growth of ice blocks. Furthermore, the first side chamber LS1 and the second side chamber LS2, which are adjacent to the central chamber LS0 via the first vertical partition wall 12j and the second vertical partition wall 12k, also function as heat insulating layers, thereby preventing the first vertical partition wall 12j and the second vertical partition wall 12k from being cooled too much, and preventing mist generated in the central chamber LS0 from freezing even if it comes into contact with them.

[0043] In addition, the side chamber 13 formed below the second side chamber LS2 (and the first side chamber LS1) functions as a heat insulating layer, which further prevents the second vertical partition wall 12k (and the first vertical partition wall 12j) from being overcooled. At this time, by operating the heater 14, the inside of the second side chamber LS2 is heated via the upper wall 13a, and also the inside of the side chamber 13 is heated, which can enhance the effect of preventing the second vertical partition wall 12k etc. from being overcooled. Furthermore, by providing the heater 14 inside the side chamber 13, which is a smaller space than the second side chamber LS2 (first side chamber LS1), it is possible to heat the entire air inside the side chamber 13 and make the temperature of the entire surface of the upper wall 13a that contacts the underside of the second side chamber LS2 (first side chamber LS1) uniform. This not only prevents icing on the upper wall 13a, but also improves the ability to maintain an appropriate temperature inside the second side chamber LS2 (first side chamber LS1) even when there is a considerable temperature difference between the heat exchanger 20 during defrosting and the outside (inside the freezer), making it possible to perform defrosting inside a freezer that is even colder.

[0044] Furthermore, by operating the heater 56 of the damper unit 50 during operation or defrosting of the unit cooler 10, it is possible to prevent the straight pipe 52 and the mounting bracket 54 from freezing and becoming stuck together, and to ensure smooth pivoting of the vanes 53 of the damper unit 50. Note that while the unit cooler 10 is stopped, an operator can open the inspection door, reach into the upper space US through the inspection hatch 12m, and perform inspections such as gripping the bent portions 53b of the vanes 53 with their fingers and lifting them up.

[0045] According to this embodiment, the sealable upper space US is formed above the lower space LS that houses the heat exchanger 20, so that the heat generated in the lower space LS during defrosting of the heat exchanger 20 remains in the upper space US and is prevented from being dissipated outside the unit cooler. This minimizes heat loss and maximizes the defrosting effect, thereby shortening the defrosting time and saving energy. Furthermore, the space of the unit cooler that is exposed to the low-temperature outside air through the wall of the housing 12 is reduced, so the risk of icing due to poor defrosting can be further reduced. Furthermore, by providing the upper space US, it is possible to prevent the hot air generated in the lower space LS from moving upward during defrosting, thereby preventing a rise in the temperature around the unit cooler.

[0046] The present invention is not limited to the above-described embodiment, and various modifications can be made. For example, instead of the heater, a hot gas defroster may be used in which hot gas flows through a pipe that penetrates the fins of a heat exchanger.

[0047] This specification includes the disclosure of the following inventions. (First aspect) a fan module having a fan; a housing enclosing the heat exchanger; a damper unit; the housing includes a first chamber that houses the heat exchanger, a second chamber that is disposed above the first chamber and is connected to the fan module, and a partition wall that is formed between the first chamber and the second chamber; the partition wall has an opening that communicates the first chamber with the second chamber, The damper unit has a blade that opens the opening when the fan is rotating and closes the opening when the fan is stationary. A unit cooler characterized by:

[0048] (Second aspect) The blades move to an open position where they open the opening by the pressure of air flowing from the first chamber to the second chamber when the fan is rotating, and move to a closed position where they close the opening by their own weight when the fan stops. The unit cooler of the first aspect is characterized by:

[0049] (Third aspect) The damper unit has a stopper member that comes into contact with the vane when the vane moves to a maximum open position and limits further movement of the vane. The unit cooler according to the first or second aspect, characterized in that:

[0050] (Fourth aspect) The blade has a receiving plate that receives air flowing from the first chamber to the second chamber and is disposed above the opening. The unit cooler according to any one of the first to third aspects, characterized in that:

[0051] (Fifth aspect) The housing has a third chamber adjacent to the first chamber and accommodating a piping assembly of the heat exchanger, and a third chamber accommodating a third chamber heater is formed at a lower end of the third chamber. The unit cooler according to any one of the first to fourth aspects, characterized in that: [Explanation of symbols]

[0052] 10 Unit Cooler 12. Case 12th floor horizontal partition wall 12h rectangular opening 13 Side Chamber 14 Heater for side chamber 20 Heat exchanger 22 Defrost heater 30 Ducted Fan Module 40 Drain pan 50 Damper unit 53 Slats 53a Receiving plate 55 Stopper member US upper space LS lower space LS0 Central Room LS1 First Concubine LS2 Second Concubine

Claims

1. a fan module having a fan; a housing enclosing the heat exchanger; a damper unit; the housing includes a first chamber that houses the heat exchanger, a second chamber that is disposed above the first chamber and is connected to the fan module, and a partition wall that is formed between the first chamber and the second chamber; the partition wall has an opening that communicates the first chamber with the second chamber, The damper unit has a blade that opens the opening when the fan is rotating and closes the opening when the fan is stationary. A unit cooler characterized by:

2. The blades move to an open position where they open the opening by the pressure of air flowing from the first chamber to the second chamber when the fan is rotating, and move to a closed position where they close the opening by their own weight when the fan is stopped.

2. The unit cooler according to claim 1.

3. The damper unit has a stopper member that comes into contact with the vane when the vane moves to a maximum open position and limits further movement of the vane.

3. The unit cooler according to claim 2.

4. The blade has a receiving plate that receives air flowing from the first chamber to the second chamber and is disposed above the opening.

3. The unit cooler according to claim 2.

5. The housing has a third chamber adjacent to the first chamber for accommodating a piping assembly of the heat exchanger, and a third chamber for accommodating a third chamber heater is formed at a lower end of the third chamber.

2. The unit cooler according to claim 1.

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