Refrigeration equipment and storage equipment

Abstract

To provide a refrigerating device that can restrain a decrease in the capacity of a cooling storage cabinet and freezing of a drain pan.SOLUTION: A refrigerating device generates cooling air for cooling articles in a cooling storage cabinet, and comprises a compressor for compressing an introduced refrigerant, a heat dissipation heat exchanger for cooling the refrigerant compressed by the compressor, a first throttle part for throttling the refrigerant cooled by the heat dissipation heat exchanger, a first heat exchanger for generating the cooling air by exchanging heat between the refrigerant throttled by the first throttle part and air, and a drain pan heat exchanger for heating a drain pan for receiving drain water of the first heat exchanger, by exchanging heat between the drain pan and the refrigerant flowing between the heat dissipation heat exchanger and the first throttle part.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present disclosure relates to a refrigeration device and a storage device.

Background Art

[0002] Conventionally, a cooling storage for storing foodstuffs at refrigeration temperature is known (see, for example, Patent Document 1). In the cooling storage of Patent Document 1, an evaporator, a defrost heater for defrosting the evaporator, and a drain pan for receiving drain water such as defrost water generated from the evaporator are arranged.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the cooling storage of Patent Document 1, since the evaporator and the drain pan are separated, the volume of the storage chamber becomes small. In order to secure the volume of the storage chamber, it may be considered to arrange the evaporator closer to the drain pan. In this case, however, the drain pan may be frozen due to heat conduction from the evaporator, and the defrosting time may become long.

[0005] The present disclosure solves the above problems, and an object thereof is to provide a refrigeration device and a storage device capable of suppressing a reduction in the volume of a cooling storage and freezing of a drain pan.

Means for Solving the Problems

[0006] The refrigeration apparatus of the present disclosure is a refrigeration apparatus for generating cooling air for cooling articles in a refrigerated storage cabinet, comprising: a compressor for compressing an introduced refrigerant; a heat exchanger for cooling the refrigerant compressed by the compressor; a first throttling section for restricting the refrigerant cooled by the heat exchanger; a first heat exchanger for generating the cooling air by exchanging heat between the refrigerant restricted by the first throttling section and air; and a drain pan heat exchanger for warming the drain pan by exchanging heat between a drain pan for receiving drain water from the first heat exchanger and the refrigerant flowing between the heat exchanger and the first throttling section. The cooling storage unit comprises a freezer storage unit cooled to freezing temperature by a first cooling air constituting the cooling air, and a refrigerated storage unit cooled to refrigeration temperature by a second cooling air constituting the cooling air, and the refrigeration device further comprises a second throttling unit that restricts the refrigerant flowing between the heat dissipation heat exchanger and the first throttling unit, and a second heat exchanger that generates the second cooling air by heat exchange between the refrigerant restricted in the second throttling unit and air, and the first throttling unit restricts the refrigerant cooled in the second heat exchanger, the drain pan heat exchanger cools the refrigerant flowing between the second heat exchanger and the first throttling unit by heat exchange, and the first heat exchanger generates the first cooling air by heat exchange between the refrigerant restricted in the first throttling unit and air. ru.

[0007] The storage device of the present disclosure comprises a cooling storage cabinet, a refrigeration device for generating cooling air to cool articles in the cooling storage cabinet, and a drain pan for receiving drain water, wherein the refrigeration device comprises a compressor for compressing an introduced refrigerant, a heat exchanger for cooling the refrigerant compressed by the compressor, a first throttling section for restricting the refrigerant cooled by the heat exchanger, a first heat exchanger for generating the cooling air by exchanging heat between the refrigerant restricted by the first throttling section and air, and a drain pan heat exchanger for warming the drain pan by exchanging heat between the drain pan that receives the drain water from the first heat exchanger and the refrigerant flowing between the heat exchanger and the first throttling section. The cooling storage unit comprises a freezer storage unit cooled to freezing temperature by a first cooling air constituting the cooling air, and a refrigerated storage unit cooled to refrigeration temperature by a second cooling air constituting the cooling air, and the refrigeration device further comprises a second throttling unit that restricts the refrigerant flowing between the heat dissipation heat exchanger and the first throttling unit, and a second heat exchanger that generates the second cooling air by heat exchange between the refrigerant restricted in the second throttling unit and air, and the first throttling unit restricts the refrigerant cooled in the second heat exchanger, the drain pan heat exchanger cools the refrigerant flowing between the second heat exchanger and the first throttling unit by heat exchange, and the first heat exchanger generates the first cooling air by heat exchange between the refrigerant restricted in the first throttling unit and air. ru. [Effects of the Invention]

[0008] The refrigeration apparatus and storage apparatus of this disclosure make it possible to reduce the volume of the refrigerated storage unit and prevent the freezing of the drain pan. [Brief explanation of the drawing]

[0009] [Figure 1] Vertical cross-sectional view showing the state of the storage device during cooling operation control according to the first and second embodiments. [Figure 2] Block diagrams of refrigeration systems according to the first and third embodiments. [Figure 3A] Diagram illustrating the flow of refrigerant during cooling operation control according to the first and third embodiments. [Figure 3B]Diagram illustrating the flow of refrigerant during defrosting operation control according to the first and third embodiments. [Figure 4] Vertical cross-sectional view showing the state of the storage device during defrosting operation control according to the first and second embodiments. [Figure 5] Block diagram of the refrigeration system according to the second embodiment [Figure 6] A schematic diagram showing the configuration of a heat exchanger for a drain pan according to the second embodiment. [Figure 7] A vertical cross-sectional view showing the state of the storage device during cooling operation control according to the third embodiment. [Figure 8] A vertical cross-sectional view showing the state of the storage device during defrosting operation control according to the third embodiment. [Figure 9] Longitudinal cross-sectional view of the storage device related to the modified example. [Figure 10] Block diagram of the refrigeration apparatus according to the above modified example. [Modes for carrying out the invention]

[0010] [First Embodiment] A first embodiment of this disclosure will be described.

[0011] <Configuration of the storage device> First, let's explain the configuration of the storage device. Figure 1 is a longitudinal cross-sectional view showing the state of the storage device during cooling operation control. The front side is the side that the user or the item transport device faces when items are loaded into or unloaded from the storage device's freezer or refrigerator compartment, and the rear side is the opposite side of the front side. The right side is the right side from the perspective of the user or transport device, and the left side is the opposite side of the right side. The top side is the top side in the posture when the user or transport device loads or unloads items, and the bottom side is the opposite side of the top side. Unless otherwise specified, "width" refers to the length in the left-right direction.

[0012] The storage device 1 shown in FIG. 1 stores the article Z at a refrigerated temperature (e.g., +1°C or more and +5°C or less) or a frozen temperature (e.g., about -20°C). The article Z is, for example, a daily necessity, fresh food, or frozen food. The storage of the article Z in the storage device 1 may be performed by the user's hand or by a transport device. The storage device 1 includes a main body portion 2 and an air curtain generation portion 3.

[0013] The main body portion 2 includes a housing 21. The housing 21 is formed in a rectangular parallelepiped box shape with an open front by an upper wall 211, a bottom wall 212, a rear wall 213, and left and right side walls 214 each having heat insulation properties.

[0014] It is possible to consider that a virtual freezer 22 and a refrigerator 23 are arranged in the internal space of the housing 21. In FIG. 1, the portions corresponding to the freezer 22 and the refrigerator 23 are indicated by a two-dot chain line. Of course, the freezer 22 and the refrigerator 23 as actual hardware may be arranged. The freezer 22 and the refrigerator 23 constitute the cooling storage of the present disclosure.

[0015] The freezer 22 stores the article Z at a frozen temperature. The freezer 22 is located above the internal space of the housing 21. The freezer 22 includes, for example, three shelves 221 arranged in the vertical direction and an upper back plate 222.

[0016] Each shelf 221 is arranged so as to span the left and right side walls 214. Each shelf 221 is configured to be able to place the article Z. The article Z placed on each shelf 221 may be stored in a storage box. The upper opening 22A, which is the front opening of the freezer 22, is not closed. The article Z is taken in and out of the freezer 22 through the upper opening 22A.

[0017] The upper back panel 222 separates the internal space of the freezer storage unit 22 from the portion located at the rear of the freezer storage unit 22 in the first flow path 311, which will be described later. The upper back panel 222 is provided to cover the portion of the rear opening, which is surrounded by the top wall 211, the left and right side walls 214, and the bottom shelf 221, except for the portion at the top end. In other words, a gap is formed between the top end of the upper back panel 222 and the top wall 211.

[0018] The refrigerated storage unit 23 stores items Z at a refrigerated temperature. The refrigerated storage unit 23 is located in the lower part of the internal space of the enclosure 21, that is, below the freezer storage unit 22. The refrigerated storage unit 23 has, for example, four shelves 231 arranged vertically. Each shelf 231 is positioned to span the left and right side walls 214. Each shelf 231 is configured to hold items Z. The lower opening 23A, which is the front opening of the refrigerated storage unit 23, is not closed. Items Z are moved in and out of the refrigerated storage unit 23 through the lower opening 23A.

[0019] Furthermore, the housing 21 is further provided with a drain pan 223, a rear plate-shaped member 224, and a lower plate-shaped member 232.

[0020] The drain pan 223 is positioned to divide the internal space of the housing 21 vertically. The drain pan 223 is positioned at a predetermined distance below the lowest shelf 221, spanning the left and right side walls 214. The front end of the drain pan 223 is positioned in front of the front end of the shelf 221, and the rear end is positioned approximately midway between the upper back plate 222 and the rear wall 213. The drain pan 223 is configured to receive drain water generated during defrosting of the first heat exchanger 420. A drain pipe (not shown) is connected to the drain pan 223 for discharging the drain water from the drain pan 223. An extension portion 223A extending upward is formed at the front end of the drain pan 223. The extension portion 223A is formed in a plate shape with its front surface approximately parallel to the vertical direction and its width being the same as the width of the drain pan 223. The upper end of the extension 223A is located below the lowest shelf 221. The upper end of the extension 223A is located almost directly below the rear end of the duct projection 321B, which will be described later.

[0021] A rear plate-like member 224 is provided at the rear end of the drain pan 223, extending upward from the rear end. The rear plate-like member 224 is positioned to span the left and right side walls 214. In other words, the rear plate-like member 224 partitions the space in front of it and the space behind it, preventing air from freely moving between them.

[0022] The lower plate-like member 232 is positioned at a predetermined distance below the lowest shelf 231, bridging the left and right side walls 214. In other words, the lower plate-like member 232 partitions the space above and below it, preventing air from freely moving between them. The front end of the lower plate-like member 232 is located almost directly below the front end of the duct projection 321B, and its rear end is fixed to the rear wall 213.

[0023] The air curtain generation unit 3 generates a first air curtain C1 and a second air curtain C2. The first air curtain C1 cools the inside of the freezer storage unit 22 by covering the upper opening 22A, bringing the temperature of the freezer storage unit 22 to the freezing temperature. The second air curtain C2 cools the inside of the refrigerator storage unit 23 by covering the lower opening 23A, bringing the temperature of the refrigerator storage unit 23 to the refrigeration temperature. The air curtain generation unit 3 comprises a first air curtain generation unit 31 and a second air curtain generation unit 32.

[0024] The first air curtain generation unit 31 comprises a first flow path 311, a first heat exchanger 420 constituting the refrigeration device 4 (see Figure 2), and a first fan 312.

[0025] The first flow path 311 circulates the first cooling air A1 used to generate the first air curtain C1 and the air constituting the first air curtain C1 in the rear, upper, front of the upper opening 22A of the freezer storage unit 22, and in the space between the freezer storage unit 22 and the refrigerator storage unit 23. The first flow path 311 is composed of the bottom shelf 221, the drain pan 223, the upper back plate 222, the rear plate-like member 224, the upper wall 211, the duct projection 321B, and the left and right side walls 214.

[0026] Specifically, the portion of the first flow path 311 between the freezer storage compartment 22 and the refrigerated storage compartment 23, and the portion behind the freezer storage compartment 22, are composed of the internal space of the duct formed by the bottom shelf 221, the drain pan 223, the upper back plate 222, the rear plate-like member 224, and the left and right side walls 214. Furthermore, the portion above the freezer storage compartment 22 in the first flow path 311 is composed of the internal space of the housing 21 above the upper end of the upper back plate 222, in front of the rear plate-like member 224, and behind the duct projection 321B. In addition, the portion in front of the upper opening 22A in the first flow path 311 is composed of the internal space of the housing 21 in front of the shelf 221 and behind the virtual plane connecting the rear end of the duct projection 321B and the upper end of the extension 223A of the drain pan 223.

[0027] The first heat exchanger 420 is positioned above the drain pan 223, that is, in the lower part of the freezer storage compartment 22 within the first flow path 311. The first heat exchanger 420 cools the air surrounding it by heat exchange to generate first cooled air A1. The temperature of the first cooled air A1 is, for example, -25°C. The first heat exchanger 420 only needs to be positioned so that the drain water from the first heat exchanger 420 is received by the drain pan 223, and for example, it may be positioned so as not to come into contact with the drain pan 223.

[0028] The first fan 312 is positioned behind the first heat exchanger 420 above the drain pan 223. The first fan 312 pushes the first cooling air A1 obtained by heat exchange in the first heat exchanger 420 to the rear.

[0029] A drain pan heat exchanger 419 is positioned on the underside of the drain pan 223 to heat the drain pan 223. The drain pan heat exchanger 419 constitutes the refrigeration system 4. The drain pan heat exchanger 419 is positioned so as to be in contact with the portion of the underside of the drain pan 223 that corresponds to the first heat exchanger 420 (the portion below the first heat exchanger 420).

[0030] The first cooling air A1, sent to the rear by the first fan 312, flows along the rear and top sides of the freezer storage unit 22 guided by the rear plate-shaped member 224 and the upper wall 211, and then flows vertically downward guided by the rear end of the duct projection 321B. This vertically downward flowing first cooling air A1 covers the entire upper opening 22A and generates a first air curtain C1 that extends vertically downward. A portion of the air constituting the first air curtain C1 passes in front of the upper opening 22A, then flows to the rear guided by the extension 223A and the drain pan 223, and is used for heat exchange in the first heat exchanger 420. In this way, the first cooling air A1 and the air constituting the first air curtain C1 are guided by the first flow path 311 and circulate along the rear, top, front of the upper opening 22A, and bottom sides of the freezer storage unit 22.

[0031] The second air curtain generating unit 32 comprises a second flow path 321, a second heat exchanger 416 constituting the refrigeration device 4, and a second fan 322.

[0032] The second flow path 321 circulates the second cooling air A2 used to generate the second air curtain C2 and the air constituting the second air curtain C2 between the front of the upper opening 22A and the lower opening 23A, the lower side of the refrigerated storage unit 23, the rear sides of the refrigerated storage unit 23 and the freezer storage unit 22, and the upper side of the freezer storage unit 22. The second cooling air A2 and the first cooling air A1 constitute the cooling air of this disclosure. The second flow path 321 is composed of an upper duct 321A, a lower plate-shaped member 232, the bottom shelf 231, a rear wall 213, a rear plate-shaped member 224, and left and right side walls 214.

[0033] Specifically, the front portions of the upper opening 22A and lower opening 23A in the second flow path 321 are comprised of the space within the housing 21 that is in front of the imaginary plane connecting the rear end of the duct projection 321B and the upper end of the extension 223A of the drain pan 223, in front of the shelf 231, and behind the imaginary plane connecting the front end of the duct projection 321B and the front end of the lower plate-shaped member 232. The lower portion of the refrigerated storage compartment 23 in the second flow path 321 is comprised of the space within the housing 21 that is between the lower plate-shaped member 232 and the lowest shelf 231. The rear portion of the refrigerated storage compartment 23 in the second flow path 321 is comprised of the space within the housing 21 that is behind the shelf 231 and in front of the rear wall 213. The rear portion of the freezer storage compartment 22 in the second flow path 321 is comprised of the space within the housing 21 that is behind the rear plate-shaped member 224 and in front of the rear wall 213. The upper portion of the freezer storage compartment 22 in the second flow path 321 is comprised of the space within the upper duct 321A.

[0034] The upper duct 321A is positioned on top of the upper wall 211. The front end of the upper duct 321A is bent downwards. The portion of the upper duct 321A that extends downwards from the front end is inserted into an opening formed in the upper wall 211 and forms a duct projection 321B that protrudes downwards from the upper wall 211. The width of the opening of the duct projection 321B is greater than or equal to the width of the upper opening 22A of the freezer storage unit 22 and greater than or equal to the width of the lower opening 23A of the refrigerator storage unit 23. The opening at the rear end of the upper duct 321A is connected to the opening at the top of a cylindrical portion formed by the rear wall 213, the rear plate-like member 224, and the left and right side walls 214.

[0035] The second heat exchanger 416 is located within the upper duct 321A, that is, in the part of the second flow path 321 located above the freezer storage compartment 22. The second heat exchanger 416 cools the air surrounding it by heat exchange to generate second cooling air A2. The temperature of the second cooling air A2 is higher than the refrigeration temperature. The temperature of the second cooling air A2 is such that the temperature of the mixture of the first cooling air A1 and the second cooling air A2 reaches the refrigeration temperature, for example, +15°C. Note that the second cooling air A2 may be heated air depending on the set temperature of the freezer storage compartment 22, the set temperature of the freezer storage compartment 23, and the ambient temperature.

[0036] The second fan 322 is located behind the second heat exchanger 416 within the upper duct 321A. The second fan 322 sends the second cooling air A2 obtained by heat exchange in the second heat exchanger 416 forward.

[0037] The second cooling air A2, sent forward by the second fan 322, flows vertically downward guided by the duct projection 321B. This vertically downward flowing second cooling air A2 covers the entire upper opening 22A and the lower opening 23A, creating a second air curtain C2 that extends vertically downward. A portion of the air constituting the second air curtain C2 passes in front of the lower opening 23A, then flows backward and upward guided by the lower plate-shaped member 232 and the rear wall 213, flowing into the rear end of the upper duct 321A and being used for heat exchange in the second heat exchanger 416. In this way, the air constituting the second cooling air A2 and the second air curtain C2 is guided by the second flow path 321 and circulates between the front of the upper opening 22A and the lower opening 23A, the underside of the refrigerated storage unit 23, the rear sides of the refrigerated storage unit 23 and the freezer storage unit 22, and the upper side of the freezer storage unit 22.

[0038] The first air curtain C1 and the second air curtain C2 have the function of separating the inside of the housing 21 from the outside of the front side of the housing 21.

[0039] Figure 2 is a block diagram of the refrigeration system. Note that Figure 2 does not represent the actual shape, size, or positional relationship of each component of the refrigeration system. As shown in Figure 2, the storage device 1 further comprises a refrigeration system 4. The refrigeration system 4 cools the freezer storage compartment 22 and the refrigerator storage compartment 23. The refrigeration system 4 comprises various components that constitute the refrigeration circuit 41 and a control unit 45.

[0040] The refrigeration circuit 41 generates first cooling air A1 to raise the temperature of the freezer storage compartment 22 to the freezing temperature, and second cooling air A2 to raise the temperature of the refrigerator storage compartment 23 to the refrigeration temperature, by exchanging heat with the refrigerant. The refrigeration circuit 41 includes a compressor 411, a heat exchanger 412, a fan for the heat exchanger 413, a first three-way valve 414, a second throttling section 415, a second heat exchanger 416, a third throttling section 417, a first throttling section 418, a heat exchanger for the drain pan 419, a first heat exchanger 420, and a second three-way valve 421.

[0041] The compressor 411 is, for example, a rotary compressor. One end of the piping 431 is connected to the compressor 411. The compressor 411 compresses the refrigerant and sends it to the piping 431.

[0042] The heat exchanger 412 is connected to the other end of the pipe 431 and to one end of the pipe 432. The heat exchanger 412 cools the refrigerant compressed by the compressor 411 and sends it to the pipe 432.

[0043] The heat exchanger fan 413 improves the cooling efficiency of the heat exchanger 412 by blowing air onto it.

[0044] The first, second, and third pipe connection ports of the first three-way valve 414 are connected to the other end of pipe 432, one end of pipe 433, and one end of the first bypass pipe 434, respectively. The other end of the first bypass pipe 434 is connected to pipe 440, which connects the compressor 411 and the second three-way valve 421. Based on the control of the control unit 45, the first three-way valve 414 can be switched to a first state in which only pipe 432 and pipe 433 are connected, or to a second state in which only the first bypass pipe 434 and pipe 433 are connected.

[0045] The second throttling section 415 is, for example, an electric expansion valve. The other end of the piping 433 and one end of the piping 435 are connected to the second throttling section 415. The second throttling section 415 restricts the flow of the refrigerant cooled by the heat exchanger 412 and sends it to the piping 435.

[0046] The other end of pipe 435 and one end of pipe 436 are connected to the second heat exchanger 416. The second heat exchanger 416 exchanges heat between the refrigerant that has been restricted in the second throttling section 415 and the air, and sends the heat-exchanged refrigerant to pipe 436.

[0047] The third throttling section 417 is, for example, an electric expansion valve. The other end of the piping 436 and one end of the piping 437 are connected to the third throttling section 417. The third throttling section 417 restricts the refrigerant flowing in from the piping 437 and sends it to the piping 436.

[0048] The first throttling section 418 is, for example, an electric expansion valve. The other end of the piping 437 and one end of the piping 438 are connected to the first throttling section 418. The first throttling section 418 restricts the flow of the refrigerant that has undergone heat exchange in the second heat exchanger 416 and sends it to the piping 438.

[0049] The pipe 437 is bent in the middle, for example, to form five folded sections 437A. The drain pan heat exchanger 419 is composed of four straight sections that connect the folded sections 437A in the pipe 437. The shape of the section in the pipe 437 that constitutes the drain pan heat exchanger 419 may be of a different shape. The drain pan heat exchanger 419 heats the drain pan 223 by exchanging heat between the refrigerant flowing through the drain pan heat exchanger 419 and the drain pan 223.

[0050] The other end of pipe 438 and one end of pipe 439 are connected to the first heat exchanger 420. The first heat exchanger 420 exchanges heat between the refrigerant, which has been restricted in the first throttling section 418, and air, and sends the heat-exchanged refrigerant to pipe 439.

[0051] The first, second, and third pipe connections of the second three-way valve 421 are connected to the other end of pipe 439, one end of pipe 440, and one end of the second bypass pipe 441, respectively. The other end of the second bypass pipe 441 is connected to pipe 432. The other end of pipe 440 is connected to the compressor 411. With this configuration, the refrigerant sent from the first heat exchanger 420 is returned to the compressor 411. Based on the control of the control unit 45, the second three-way valve 421 can be switched between a first state in which only pipe 439 and pipe 440 are connected, and a second state in which only pipe 439 and the second bypass pipe 441 are connected.

[0052] In the refrigeration circuit 41, piping 431-433 and 435-440 constitute the first refrigerant circuit B1. Piping 431, 432, 441, 439, 438, 437, 436, 435, 433, 434, and 440 constitute the second refrigerant circuit B2. The first three-way valve 414 and the second three-way valve 421 constitute the switching section 422.

[0053] The control unit 45 performs cooling operation control to generate first cooling air A1 and second cooling air A2 in the refrigeration circuit 41, and defrosting operation control to generate second cooling air A2 in the refrigeration circuit 41 and melt the frost on the first heat exchanger 420. The cooling operation control is an example of the first operation control, and the defrosting operation control is an example of the second operation control.

[0054] <Operation of the storage device> Next, the operation of the storage device 1 will be explained.

[0055] <Cooling operation control> First, let's explain the cooling operation control as part of the operation of the storage device 1. Figure 3A is an explanatory diagram of the refrigerant flow during cooling operation control.

[0056] In cooling operation control, the refrigeration system 4 cools the inside of the freezer storage 22 and the refrigerator storage 23 by generating first cooling air A1 in the first heat exchanger 420 and second cooling air A2 in the second heat exchanger 416, as shown in Figures 1 and 3A, through the control unit 45 controlling the refrigeration circuit 41. Specifically, the control unit 45 of the refrigeration system 4 sets the first three-way valve 414 and the second three-way valve 421 to the first state. As shown in Figure 3A, in the first state, the refrigerant flowing into the first three-way valve 414 no longer flows through the first bypass piping 434 shown by the dashed line. Also, the refrigerant flowing into the second three-way valve 421 no longer flows through the second bypass piping 441 shown by the dashed line. Therefore, the refrigerant flows through the first refrigerant circuit B1 in the direction indicated by arrow Y, and after exiting the compressor 411, it passes through the heat exchanger 412, the second throttling section 415, the second heat exchanger 416, the third throttling section 417, the heat exchanger for the drain pan 419, the first throttling section 418, and the first heat exchanger 420 in that order, before returning to the compressor 411.

[0057] Then, under the control of the control unit 45, the heat exchanger fan 413 and the first and second fans 312 and 322 are driven, and the amount of throttling (valve opening) of the refrigerant in the first and second throttling sections 418 and 415 is set to a predetermined state, and the amount of throttling in the third throttling section 417 is set to 0 (valve fully open), at which point the compressor 411 is driven at a predetermined operating frequency to compress the refrigerant. The heat exchanger 412 cools the refrigerant compressed by the compressor 411. The second throttling section 415 further lowers the temperature of the refrigerant by throttling the refrigerant cooled in the heat exchanger 412. The second heat exchanger 416 generates second cooling air A2 by exchanging heat between the refrigerant, which has been depressurized by the second throttling section 415 and reached a predetermined temperature, and air.

[0058] Since the throttling amount of the third throttling section 417 is set to 0, the refrigerant that has undergone heat exchange in the second heat exchanger 416 flows into the drain pan heat exchanger 419 at almost the same temperature (for example, 15°C). Then, the drain pan 223 is heated by the heat exchange between the refrigerant that has flowed into the drain pan heat exchanger 419 and the drain pan 223. As a result, freezing of the drain pan 223 due to heat conduction from the first heat exchanger 420 is suppressed.

[0059] The first throttling section 418 further lowers the temperature of the refrigerant by throttling the refrigerant, for example, which has been heat-exchanged in the drain pan heat exchanger 419 and is at 0°C. The first heat exchanger 420 generates first cooling air A1 by heat-exchanging the refrigerant, whose temperature has been lowered by the first throttling section 418, with air. The refrigerant that has been heat-exchanged in the first heat exchanger 420 is returned to the compressor 411.

[0060] The first cooling air A1 generated by the first heat exchanger 420 at the bottom of the freezer storage unit 22 is sent to the rear by the first fan 312, and then flows from bottom to top at the rear of the freezer storage unit 22. The first cooling air A1 that has flowed at the rear of the freezer storage unit 22 then flows in front of the upper opening 22A via the top of the freezer storage unit 22, thereby generating a first air curtain C1 that covers the entire upper opening 22A.

[0061] The second cooling air A2 generated by the second heat exchanger 416 above the freezer storage unit 22 is sent forward by the second fan 322 and then flows in front of the upper opening 22A and the lower opening 23A, thereby generating a second air curtain C2. Preferably, the air velocity of the second air curtain C2 when flowing in front of the upper opening 22A is the same as the air velocity of the first air curtain C1 flowing in front of the upper opening 22A.

[0062] When the air from the second air curtain C2 passes in front of the freezer storage unit 22, heat exchange occurs between the air from the first air curtain C1 and the air from the second air curtain C2. This heat exchange lowers the temperature of the air in the second air curtain C2 to the refrigeration temperature. A portion of the air that has passed in front of the freezer storage unit 22 is guided to the rear below the freezer storage unit 22 by the drain pan 223 and reused for heat exchange in the first heat exchanger 420. At this time, the extension 223A separates the first air curtain C1 and the second air curtain C2, which are flowing downward in parallel, again into two, preventing the relatively cooler air at the rear from flowing into the front portion that has reached the refrigeration temperature.

[0063] The air in the second air curtain C2, which has undergone heat exchange with the air in the first air curtain C1, covers the entire lower opening 23A. The air in the second air curtain C2, having passed in front of the refrigerated storage unit 23, flows backward and upward in that order due to the lower plate-shaped member 232 and the rear wall 213, and is then guided to the upper duct 321A and reused for heat exchange in the second heat exchanger 416.

[0064] Finally, the temperature inside the freezer 22 is adjusted to the freezing temperature (for example, -20°C), and the temperature inside the refrigerator 23 is adjusted to the refrigeration temperature (for example, +3°C).

[0065] <Defrosting operation control> Next, we will explain the defrosting operation control. Figure 3B is an explanatory diagram of the refrigerant flow during defrosting operation control. Figure 4 is a longitudinal cross-sectional view showing the state of the storage device during defrosting operation control.

[0066] In defrosting operation control, the control unit 45 of the refrigeration unit 4 sets the first three-way valve 414 and the second three-way valve 421 to the second state. As shown in Figure 3B, in the second state, the refrigerant flowing into the first three-way valve 414 does not flow through a portion of the piping 432 shown by the dashed line. Also, the refrigerant flowing into the second three-way valve 421 does not flow through a portion of the piping 440 shown by the dashed line. Therefore, the refrigerant flows through the second refrigerant circuit B2 in the direction indicated by the arrow Y, and after exiting the compressor 411, it passes through the heat exchanger 412, the first heat exchanger 420, the first throttling section 418, the drain pan heat exchanger 419, the third throttling section 417, the second heat exchanger 416, and the second throttling section 415 in that order, before returning to the compressor 411.

[0067] Next, the control unit 45 stops the operation of the heat exchanger fan 413 and the first fan 312, while keeping the second fan 322 running. With this control, as shown in Figure 4, the second cooling air A2 used to generate the second air curtain C2 and the air constituting the second air curtain C2 circulate through the second flow path 321, while the first cooling air A1 used to generate the first air curtain C1 and the air constituting the first air curtain C1 do not circulate through the first flow path 311. The control unit 45 controls the first and second throttling sections 418 and 415 so that the amount of throttling of the refrigerant in the first and second throttling sections 418 and 415 is smaller than during cooling operation control, for example, by setting the throttling amount to 0 (opening the valves completely). The control unit 45 controls the amount of throttling of the third throttling section 417 so that when the second heat exchanger 416 exchanges heat between the refrigerant throttled by the third throttling section 417 and the air, a second cooling air A2 at a temperature lower than the refrigeration temperature (for example, -30°C) is generated, that is, a second cooling air A2 at a temperature lower than the temperature of the second cooling air A2 during cooling operation control is generated.

[0068] When the above control is performed, the rotation speed of the heat exchanger fan 413 is controlled so that the temperature of the refrigerant coming out of the heat exchanger 412 is controlled to be around 50°C. In the following, the refrigerant coming out of the heat exchanger 412 during defrosting operation control may be referred to as "worm gas". The worm gas passes through the second three-way valve 421 and flows into the first heat exchanger 420. The frost that has formed on the first heat exchanger 420 melts due to the heat of the worm gas. The drain pan 223 is heated by the first heat exchanger 420, which has been heated by the worm gas. At this time, heat exchange between the worm gas and air takes place in the first heat exchanger 420, but since the first fan 312 is stopped, the first air curtain C1 of air heated by the worm gas is not generated.

[0069] Since the throttling amount of the first throttling section 418 is set to 0, the refrigerant that has cooled and liquefied by melting the frost on the first heat exchanger 420 flows into the drain pan heat exchanger 419 at its original temperature (for example, 15°C). Then, the drain pan 223 is warmed by the heat exchange between the refrigerant that has flowed into the drain pan heat exchanger 419 and the drain pan 223. As a result, freezing of the drain pan 223 is suppressed. In addition, the inside of the refrigerated storage unit 23 is warmed by the heat exchange between the refrigerant that has flowed into the drain pan heat exchanger 419 and the air inside the refrigerated storage unit 23.

[0070] The third throttling section 417 further lowers the temperature of the refrigerant by throttling the refrigerant that has been heat-exchanged in the drain pan heat exchanger 419. The second heat exchanger 416 generates second cooling air A2 by exchanging heat between the refrigerant, whose temperature has been lowered by the third throttling section 417, and air. The second cooling air A2 is sent forward by the second fan 322, generating a second air curtain C2. As the second air curtain C2 passes in front of the freezer storage 22 and the refrigerator storage 23, temperature changes in the freezer storage 22 are suppressed. In addition, although the temperature of the air in the second air curtain C2 passing in front of the refrigerator storage 23 is lower than during cooling operation control (for example, -20°C), temperature changes in the refrigerator storage 23 are suppressed because the air inside the refrigerator storage 23 is warmed by heat exchange with the refrigerant in the drain pan heat exchanger 419.

[0071] The refrigerant that has undergone heat exchange in the second heat exchanger 416 returns to the compressor 411 with little to no throttling, or no throttling at all, in the second throttling section 415.

[0072] Based on the temperature of the first heat exchanger 420 detected by a temperature sensor (not shown), the timer setting time, the detection results of the defrosting status, etc., the control unit 45 determines that it is time to terminate the defrosting operation control and returns the first and second three-way valves 414, 421, the heat exchanger fan 413, the first fan 312, and the first, second, and third throttle sections 418, 415, 417 to the state they were in during the cooling operation control.

[0073] <Effects of the First Embodiment> The refrigeration system 4 includes a compressor 411, a heat exchanger 412, a first throttling section 418, a first heat exchanger 420 that generates first cooling air A1 by exchanging heat between the refrigerant throttled in the first throttling section 418 and air, and a drain pan heat exchanger 419 that heats the drain pan 223 by exchanging heat between the refrigerant flowing between the heat exchanger 412 and the first throttling section 418 and the drain pan 223. With this configuration, the drain pan heat exchanger 419 can always heat the drain pan 223 by heat exchange using the refrigerant before it is throttled in the first throttling section 418, while the inside of the refrigerated storage unit 22 is being cooled by the first cooling air A1. Therefore, even if the first heat exchanger 420 is positioned close to the drain pan 223, the decrease in the temperature of the drain pan 223 due to heat conduction from the first heat exchanger 420 can be suppressed, thereby preventing a reduction in the volume of the freezer storage unit 22 and preventing the freezing of the drain pan 223. Furthermore, in configurations using a heating element such as a heater, the defrosting time for the frozen drain pan 223 becomes longer, and there is a risk that the temperature of the freezer storage unit 22 will rise due to the heat generated by the heating element. However, in the configuration of the first embodiment, the freezing of the drain pan 223 can be suppressed without using a heating element, thus suppressing the temperature rise of the freezer storage unit 22. Therefore, it is possible to prevent the items Z inside the freezer storage unit 22 from melting or the quality of the items Z from deteriorating. In addition, since the freezing of the drain pan 223 can be suppressed without using a heating element, an increase in power consumption can be suppressed.

[0074] The refrigeration device 4 further includes a second throttling section 415 and a second heat exchanger 416 that generates second cooling air A2 by heat exchange between the refrigerant throttled in the second throttling section 415 and air. With this configuration, the drain pan heat exchanger 419 can keep the drain pan 223 warm at all times to prevent it from freezing while the inside of the freezer storage 22 is being cooled using the first cooling air A1 and the inside of the refrigerator storage 23 is being cooled using the second cooling air A2. In addition, because the drain pan 223 is warmed, the temperature difference between the drain pan 223 and the inside of the refrigerator storage 23 can be reduced, and the occurrence of condensation can be suppressed. Therefore, it is possible to prevent the drain pan 223, which has been cooled by heat conduction from the first heat exchanger 420, from freezing, or the items Z inside the refrigerator storage 23 from getting wet or the quality of the items Z from deteriorating due to condensation.

[0075] The heat exchanger 419 for the drain pan is composed of a portion of the piping 437. Therefore, freezing of the drain pan 223 can be suppressed with an even simpler configuration, without the need to use a heat exchanger that is separate from the piping.

[0076] The portion of the drain pan heat exchanger 419 in the piping 437 is positioned to be in contact with the lower surface of the drain pan 223. Therefore, the drain pan 223 can be heated almost uniformly by heat conduction in the drain pan 223, preventing localized freezing of the drain pan 223. Furthermore, since the drain pan heat exchanger 419 does not come into contact with the drain water, even if copper, which is commonly used as the material for the piping 437, is used, and iron, which is commonly used as the material for the drain pan 223, corrosion of the drain pan heat exchanger 419 can be suppressed.

[0077] The refrigeration system 4 further comprises a first refrigerant circuit B1, a second refrigerant circuit B2, a switching unit 422, and a control unit 45. The control unit 45 performs cooling operation control, which controls the switching unit 422 so that the refrigerant flows through the first refrigerant circuit B1, and defrosting operation control, which controls the switching unit 422 so that the refrigerant flows through the second refrigerant circuit B2. Therefore, in cooling operation control, the inside of the freezer storage 22 and the refrigerator storage 23 can be cooled using the first and second cooling airs A1 and A2. In addition, in defrosting operation control, the first heat exchanger 420 can be defrosted, and temperature changes in the freezer storage 22 and the refrigerator storage 23 can be suppressed using the second cooling air A2. Thus, without using a heater or a fan that circulates hot air, the first heat exchanger 420 can be defrosted with a simple configuration that only involves switching the flow path of the refrigerant and changing the control state of the refrigeration circuit 41. Furthermore, in both cooling operation control and defrosting operation control, the drain pan heat exchanger 419 can suppress freezing of the drain pan 223. Also, during defrosting operation control, the drain pan 223 can be heated from above by the first heat exchanger 420 heated by the worm gas, and the drain pan heat exchanger 419 can be heated from below. In particular, since the control unit 45 controls the switching unit 422, the administrator of the storage device 1 can have the refrigeration device 4 perform cooling operation control or defrosting operation control without having to operate the switching unit 422.

[0078] The refrigeration unit 4 further includes a third throttling section 417. When performing cooling operation control, the control unit 45 controls the first throttling section 418 and the second throttling section 415 to restrict the refrigerant flow, while controlling the third throttling section 417 not to restrict the refrigerant flow. When performing defrosting operation control, the control unit 45 controls the third throttling section 417 to restrict the refrigerant flow, while controlling the first throttling section 418 not to restrict the refrigerant flow. In this way, when performing defrosting operation control, by not restricting the refrigerant flow at the first throttling section 418, high-temperature refrigerant can be flowed to the drain pan heat exchanger 419, and the drain pan 223 can be heated efficiently. Also, when performing defrosting operation control, by restricting the refrigerant flow at the third throttling section 417 to lower the refrigerant temperature, the second heat exchanger 416 can generate second cooling air A2 at an appropriate temperature.

[0079] [Second Embodiment] Next, a second embodiment of this disclosure will be described.

[0080] <Configuration of the storage device> First, let's explain the configuration of the storage device. Figure 5 is a block diagram of the refrigeration system. Figure 6 is a schematic diagram showing the configuration of the heat exchanger for the drain pan. As shown in Figure 1, the difference between the storage device 1 of the first embodiment and the storage device 1A of the second embodiment is the configuration of the heat exchanger 423 for the drain pan of the refrigeration system 4, so we will explain mainly the configuration of the heat exchanger 423 for the drain pan. Also, Figure 5 does not represent the actual shape, size, or positional relationship of each component of the refrigeration system. Furthermore, the positional relationships of the components other than the drain pan 223, the first heat exchanger 420, and the heat exchanger 423 for the drain pan shown in Figure 6 do not represent the actual positional relationships.

[0081] As shown in Figures 5 and 6, the portion of the drain pan heat exchanger 423 in the piping 437 comprises a first branch pipe 437B and a second branch pipe 437C, with one end of each connected to the first branch pipe and the other end of each connected to the second branch pipe. The first branch pipe 437B and the second branch pipe 437C are in contact with the lower surface of the drain pan 223 and are arranged side by side in the left-right direction.

[0082] One end of the first branch pipe 437B and the second branch pipe 437C are connected at connection position P1, and the other end is connected at connection position P2. The refrigerant that has undergone heat exchange in the second heat exchanger 416 flows into the first and second branch pipes 437B and 437C via connection position P1 and flows out from the first and second branch pipes 437B and 437C via connection position P2. The first and second branch pipes 437B and 437C each consist of a first and second outer section 437B1 and 437C1, and a first and second inner section 437B2 and 437C2, respectively. The first and second outer sections 437B1 and 437C1 are configured to guide the refrigerant that has flowed in from one end (connection position P1) of the first and second branch pipes 437B and 437C in the rearward direction indicated by arrow Y1 in Figure 6. The first and second inner portions 437B2 and 437C2 are positioned closer to the center of the drain pan 223 than the first and second outer portions 437B1 and 437C1. The first and second inner portions 437B2 and 437C2 are configured to guide the refrigerant, which has been guided backward by the first and second outer portions 437B1 and 437C1, forward in the direction indicated by arrow Y2 to the other end (connection position P2). The backward direction indicated by arrow Y1 is an example of the first direction of this disclosure, and the forward direction indicated by arrow Y2 is an example of the second direction of this disclosure.

[0083] For example, the first and second branch pipes 437B and 437C may be arranged in a front-to-back direction, and the refrigerant that has undergone heat exchange in the second heat exchanger 416 may be guided in one of the right and left directions (first direction), then in the other of the right and left directions (second direction) at the center of the drain pan 223, before being guided to the first throttling section 418.

[0084] <Operation of the storage device> Next, the operation of the storage device 1A, specifically the cooling operation control and the defrosting operation control, will be described. The difference between the first and second embodiments lies in the heating state of the drain pan 223 by the drain pan heat exchanger 423; therefore, this difference will be the focus of the explanation.

[0085] <Cooling operation control> First, the cooling operation control will be explained. In the cooling operation control, the control unit 45 of the refrigeration device 4 controls the refrigeration circuit 41 and the first and second fans 312 and 322 in the same manner as the cooling operation control of the first embodiment. Through this control, the temperature inside the freezer storage compartment 22 is adjusted to the freezing temperature, and the temperature inside the refrigerator storage compartment 23 is adjusted to the refrigeration temperature, just as when the cooling operation control of the first embodiment was performed.

[0086] In the cooling operation control, since the throttling amount of the third throttling section 417 is set to 0, the refrigerant that has undergone heat exchange in the second heat exchanger 416 flows into one end of the first and second branch pipes 437B and 437C that constitute the drain pan heat exchanger 423 at almost the same temperature (for example, 15°C). The refrigerant that has flowed into the first and second branch pipes 437B and 437C is first guided backward by the first and second outer sections 437B1 and 437C1. Heat exchange between the refrigerant and the drain pan 223 takes place in the first and second outer sections 437B1 and 437C1, so the left and right ends of the drain pan 223 are heated.

[0087] The refrigerant guided backward by the first and second outer sections 437B1 and 437C1 is guided forward by the first and second inner sections 437B2 and 437C2. Heat exchange between the refrigerant and the drain pan 223 takes place in the first and second inner sections 437B2 and 437C2, so the central part of the drain pan 223 in the left-right direction is heated. The refrigerant used for heat exchange in the first and second inner sections 437B2 and 437C2 is at a lower temperature than the refrigerant used for heat exchange in the first and second outer sections 437B1 and 437C1, that is, the refrigerant used for heat exchange in the first and second outer sections 437B1 and 437C1. For this reason, it can be considered that the amount of heat input due to heat exchange in the central part of the drain pan 223 in the left-right direction is less than the amount of heat input due to heat exchange in the parts at both ends. However, the rightmost part of the drain pan 223 is heated by the refrigerant flowing through the first outer part 437B1, the leftmost part is heated by the refrigerant flowing through the second outer part 437C1, while the central part is heated by the refrigerant flowing through the first and second inner parts 437B2 and 437C2, respectively. Therefore, the amount of heat input to the central part of the drain pan 223 in the left-right direction can be made approximately the same as the amount of heat input to the parts on both the left and right ends.

[0088] The refrigerant, which has undergone heat exchange with the drain pan 223, is guided to the first throttling section 418 via the other ends of the first and second branch pipes 437B and 437C. The temperature of the refrigerant guided to the first throttling section 418 is, for example, 3°C.

[0089] <Defrosting operation control> Next, the defrosting operation control will be described. In the defrosting operation control, the control unit 45 of the refrigeration system 4 controls the refrigeration circuit 41 and the first and second fans 312 and 322 in the same manner as the defrosting operation control of the first embodiment. This control defrosts the first heat exchanger 420, just as when the defrosting operation control of the first embodiment is performed, and also suppresses temperature changes in the freezer storage 22 and the refrigerator storage 23.

[0090] In the defrosting operation control, since the throttling amount of the first throttling section 418 is set to 0, the refrigerant that has cooled and liquefied by melting the frost on the first heat exchanger 420 flows into the other ends of the first and second branch pipes 437B and 437C that constitute the drain pan heat exchanger 423 at the same temperature (for example, 15°C). The refrigerant that has flowed into the first and second branch pipes 437B and 437C is first guided backward by the first and second inner sections 437B2 and 437C2. Heat exchange takes place between the refrigerant and the drain pan 223 in the first and second inner sections 437B2 and 437C2, so that the central part of the drain pan 223 in the left-right direction is heated.

[0091] The refrigerant, guided backward by the first and second inner portions 437B2 and 437C2, is guided forward by the first and second outer portions 437B1 and 437C1. Heat exchange occurs between the refrigerant and the drain pan 223 in the first and second outer portions 437B1 and 437C1, causing the left and right ends of the drain pan 223 to be heated.

[0092] As defrosting of the first heat exchanger 420 progresses, the heat from the worm gas in the first heat exchanger 420 causes the temperature of the refrigerant in the first and second branch pipes 437B and 437C to rise. The refrigerant that has undergone heat exchange with the drain pan 223 is guided to the third throttling section 417 through one end of the first and second branch pipes 437B and 437C.

[0093] <Effects of the second embodiment> According to the storage device 1A of the second embodiment, in addition to the same effects as the storage device 1 of the first embodiment, the following effects can be achieved. The first branch pipe 437B constituting the heat exchanger 423 for the drain pan is configured to guide the refrigerant that has been heat-exchanged in the second heat exchanger 416 in the rearward direction, then guide it in the forward direction on the second branch pipe 437C side, and then lead it to the first throttling section 418. The second branch pipe 437C is configured to guide the refrigerant that has been heat-exchanged in the second heat exchanger 416 in the rearward direction, then guide it in the forward direction on the first branch pipe 437B side, and then lead it to the first throttling section 418. With this configuration, as described above, the amount of heat input to the central part of the drain pan 223 in the left-right direction and the amount of heat input to the parts on both the left and right ends can be made approximately the same, and the entire drain pan 223 can be heated uniformly.

[0094] [Third Embodiment] Next, a third embodiment of this disclosure will be described.

[0095] <Configuration of the storage device> First, the configuration of the storage device will be described. Figure 7 is a longitudinal cross-sectional view showing the state of the storage device during cooling operation control. As shown in Figure 7, the differences between the storage device 1 of the first embodiment and the storage device 1B of the third embodiment are the arrangement of the lower back plate 233 and the third fan 33, and the shape of the rear plate-shaped member 225, so these differences will be the focus of the explanation. In addition, in the third embodiment, a configuration in which the drain pan heat exchanger 419 of the first embodiment is arranged in the storage device 1B is illustrated, but the drain pan heat exchanger 423 of the second embodiment may also be arranged.

[0096] The lower back plate 233 constitutes the refrigerated storage compartment 23 and separates the internal space of the refrigerated storage compartment 23 from the area located at the rear of the refrigerated storage compartment 23. The lower back plate 233 is provided to cover the rear opening, which is surrounded by the drain pan 223, the left and right side walls 214, and the bottom shelf 231, except for the uppermost predetermined area. The area between the upper end of the lower back plate 233 and the lower surface of the drain pan 223 functions as a circulation through-hole 233A. The circulation through-hole 233A is an example of a through-hole in this disclosure.

[0097] The third fan 33 constitutes the air curtain generation unit 3. The third fan 33 is positioned on the lower plate-shaped member 232 so as to be located in the lower part of the refrigerated storage unit 23 in the second flow path 321, and sends the air from the second air curtain C2 and the circulating air A3 to the rear.

[0098] The rear plate-shaped member 225 is formed to be longer downwards than the rear plate-shaped member 224 of the first embodiment. Specifically, the rear plate-shaped member 225 is formed so that its center is connected to the rear end of the drain pan 223, and its lower end is located at approximately the same height as the bottom shelf 231. The bottom shelf 231 of the refrigerated storage unit 23, the lower plate-shaped member 232, the lower back plate 233, the rear plate-shaped member 225, the drain pan 223, the circulation through hole 233A, and the left and right side walls 214 constitute a circulation channel 34. The circulation channel 34 circulates the air sent by the third fan 33 as circulating air A3 in the rear, upper, front, and lower parts of the refrigerated storage unit 23. In the third embodiment, the rear portion of the refrigerated storage unit 23 in the second channel 321 is composed of the space inside the housing 21 that is behind the rear plate-shaped member 225 and in front of the rear wall 213.

[0099] <Operation of the storage device> Next, the operation of the storage device 1B will be described, specifically the cooling operation control and the defrosting operation control.

[0100] <Cooling operation control> First, the cooling operation control will be explained. At the start of the cooling operation control, the control unit 45 of the refrigeration device 4 controls the refrigeration circuit 41 and the first and second fans 312 and 322 in the same manner as the cooling operation control of the first embodiment, while not driving the third fan 33. With this control, the first cooling air A1 used to generate the first air curtain C1 and the air constituting the first air curtain C1 circulate through the first flow path 311, and the second cooling air A2 used to generate the second air curtain C2 and the air constituting the second air curtain C2 circulate through the second flow path 321, just as when the cooling operation control of the first embodiment was performed. Through this circulation, the temperature inside the freezer storage compartment 22 is adjusted to the freezing temperature, and the temperature inside the refrigerator storage compartment 23 is adjusted to the refrigeration temperature.

[0101] Based on the detection results of a temperature sensor (not shown), the control unit 45 of the refrigeration device 4 determines that the temperature inside the refrigerated storage compartment 23 has fallen below the refrigeration temperature (for example, 3±2℃), and starts driving the third fan 33 while maintaining the control state of the refrigeration circuit 41 and the first and second fans 312 and 322. This control increases the airflow velocity along the lower plate-shaped member 232 due to the third fan 33. As shown in Figure 7, some of the air that has passed through the third fan 33 flows into the second flow path 321 and is reused to generate the second cooling air A2, while the remainder flows into the circulation flow path 34 as circulating air A3.

[0102] The circulating air A3 that flows into the circulation channel 34 passes through the circulation through-hole 233A and flows forward. Upon reaching the lower opening 23A, it flows downward together with the air from the second air curtain C2. The air that reaches the lower plate-shaped member 232 then passes through the third fan 33, and a portion of it is reused to generate the second cooling air A2, while the remainder flows into the circulation channel 34 as circulating air A3. In this way, during cooling operation control, the circulating air A3 circulates through the circulation channel 34.

[0103] As the circulating air A3 passes over the upper part of the refrigerated storage compartment 23, heat exchange between the refrigerant in the drain pan heat exchanger 419 and the drain pan 223 is promoted, further suppressing the freezing of the drain pan 223. Also, as the circulating air A3 passes over the upper part of the refrigerated storage compartment 23, heat exchange occurs between the circulating air A3 and the refrigerant in the drain pan heat exchanger 419, causing the temperature of the circulating air A3 to rise. As this heated circulating air A3 passes in front of the lower opening 23A, the inside of the refrigerated storage compartment 23 is heated, and the temperature inside the refrigerated storage compartment 23 is maintained at the refrigeration temperature. In addition, the circulation of the circulating air A3 suppresses the occurrence of temperature unevenness inside the refrigerated storage compartment 23.

[0104] <Defrosting operation control> Next, we will explain the defrosting operation control. Figure 8 is a vertical cross-sectional view showing the state of the storage device during defrosting operation control.

[0105] In defrosting operation control, the control unit 45 of the refrigeration system 4 controls the refrigeration circuit 41 and the first and second fans 312 and 322 in the same manner as in the defrosting operation control of the first embodiment, while driving the third fan 33. With this control, as shown in Figure 8, the second cooling air A2 used to generate the second air curtain C2 and the air constituting the second air curtain C2 circulate through the second flow path 321, while the first cooling air A1 used to generate the first air curtain C1 and the air constituting the first air curtain C1 do not circulate through the first flow path 311, similar to when the defrosting operation control of the first embodiment is performed. As a result, the first heat exchanger 420 is defrosted, and temperature changes in the freezer storage 22 and the refrigerator storage 23 are suppressed.

[0106] Furthermore, similar to when the cooling operation control of the third embodiment is performed, the circulating air A3 circulates through the circulation channel 34. As a result, heat exchange between the refrigerant in the drain pan heat exchanger 419 and the drain pan 223 is promoted, further suppressing freezing of the drain pan 223, and the temperature inside the refrigerated storage unit 23 is maintained at the refrigeration temperature as the circulating air A3, whose temperature has risen, passes in front of the lower opening 23A. In addition, there is a risk of condensation occurring due to the temperature difference between the drain pan 223 (e.g., -20°C) cooled by heat conduction from the first heat exchanger 420 and the air inside the refrigerated storage unit 23 (e.g., +3°C), but the circulation of the circulating air A3 suppresses the occurrence of condensation.

[0107] When the control unit 45 determines to terminate the defrosting operation control based on the temperature of the first heat exchanger 420, the timer setting time, the detection result of the defrosting status, etc., it returns the first and second three-way valves 414, 421, the heat exchanger fan 413, the first fan 312, and the first, second, and third throttle sections 418, 415, 417 to the state they were in during the cooling operation control, while continuing to drive the third fan 33. Immediately after the termination of the defrosting operation control, at least one of the first heat exchanger 420 and the drain pan 223 may be wet with drain water. If the cooling operation control is restarted in this state, there is a risk that the drain water will freeze due to heat conduction from the first heat exchanger 420. In this third embodiment, since the third fan 33 is driven when the cooling operation control is restarted, the circulating air A3 promotes heat exchange between the refrigerant in the drain pan heat exchanger 419 and the drain pan 223, thereby suppressing the freezing of the drain water. For example, if the control unit 45 determines, based on the timer setting time, that the drain water adhering to the first heat exchanger 420 has fallen into the drain pan 223 and been discharged from the drain pan 223, it stops driving the third fan 33.

[0108] <Effects of the Third Embodiment> According to the third embodiment of the storage device 1B, in addition to the same effects as the storage device 1 of the first embodiment, the following effects can be achieved. The storage device 1B includes a lower back plate 233 that separates the internal space of the refrigerated storage compartment 23 from the part located at the rear of the refrigerated storage compartment 23. A circulation through-hole 233A is formed between the lower back plate 233 and the drain pan 223. A third fan 33 is arranged in the part of the second flow path 321 located at the bottom of the refrigerated storage compartment 23. In this configuration, by driving the third fan 33 during cooling operation control, as described above, the heat exchange between the refrigerant in the drain pan heat exchanger 419 and the drain pan 223 can be promoted due to the influence of the circulating air A3 passing through the upper part of the refrigerated storage compartment 23, and the freezing of the drain pan 223 can be further suppressed. Furthermore, as the circulating air A3 passes through the upper part of the refrigerated storage unit 23, the temperature of the circulating air A3 rises due to heat exchange with the refrigerant in the drain pan heat exchanger 419, thereby warming the inside of the refrigerated storage unit 23 and maintaining the temperature inside the refrigerated storage unit 23 at the refrigeration temperature.

[0109] [Modified examples of embodiments] This disclosure is not limited to the embodiments described herein, and various modifications can be made without departing from its spirit. Furthermore, the above embodiments and the modifications shown below may be combined in any way, as long as they function properly.

[0110] For example, in the first embodiment, a configuration in which a drain pan heat exchanger 419 is placed in a storage device 1 having both a freezer storage compartment 22 and a refrigerated storage compartment 23 was illustrated. However, as shown in Figure 9, the drain pan heat exchanger 419 may also be provided in a storage device 1C having only a freezer storage compartment 22 (the cooling storage compartment of this disclosure) and no refrigerated storage compartment 23. In this case, the second flow path 321, the second fan 322, and the second heat exchanger 416 become unnecessary. Also, as shown in Figure 10, the refrigeration circuit 41C of the refrigeration device 4C is configured to connect the other end of the piping 433 to the third throttling section 417 without the second throttling section 415 and the second heat exchanger 416 present in the refrigeration circuit 41 of the first embodiment. Furthermore, the drain pan heat exchanger 423 of the second embodiment may also be applied to a storage device 1C having only a freezer storage compartment 22, as shown in Figures 9 and 10. Furthermore, in the configuration shown in Figures 9 and 10, the first throttling section 418 and the first heat exchanger 420 may be controlled to generate a second cooling air A2, thereby allowing the freezer storage unit 22 to function as a refrigerated storage unit (a cooling storage unit according to this disclosure).

[0111] Although the example given shows that the heat exchangers 419 and 423 for the drain pan are composed of a portion of the piping 437, a heat exchanger composed separately from the piping 437 may also be used.

[0112] Although the example shows the drain pan heat exchangers 419 and 423 positioned so as to be in contact with the lower surface of the drain pan 223, they may also be positioned away from the drain pan 223 so that heat exchange with the drain pan 223 can be performed via the air present between them. Alternatively, the drain pan heat exchangers 419 and 423, which are made of a less corrosive material, may be placed on top of the drain pan 223.

[0113] Although the configuration shown illustrates that the control unit 45 switches the first and second three-way valves 414 and 421 to the first or second state, this may also be done by the administrators of the storage devices 1, 1A, and 1B.

[0114] The refrigeration circuit 41 may be configured to circulate the refrigerant using only the first refrigerant circuit B1, without providing the first and second three-way valves 414, 421 and the first and second bypass pipes 434, 441. In this case, since defrosting operation control using the second refrigerant circuit B2 cannot be performed, the third throttle section 417 does not need to be provided.

[0115] Although the example shows the refrigeration device 4 being applied to storage devices 1, 1A, and 1B that do not have doors to close the front openings of the freezer storage compartment 22 and the refrigerator storage compartment 23, it may also be applied to storage devices such as refrigerators that have doors. [Industrial applicability]

[0116] This disclosure is applicable to refrigeration equipment and storage equipment. [Explanation of Symbols]

[0117] 1,1A,1B,1C Storage device 2 Main body 3. Air curtain generation unit 4,4C refrigeration equipment 21 cabinets 22 Freezer storage 22A Upper opening 23 Refrigerated storage 23A Lower opening 31. First air curtain generation unit 32 Second air curtain generation unit 33 Third Fan 34 Circulation channels 41,41C Refrigeration Circuit 45 Control Unit 211 Upper wall 212 Bottom wall 213 Back wall 214 Side wall 221,231 shelves 222 Upper back plate 223 Drain pan 223A Extension 224,225 Rear plate-shaped member 232 Lower plate-shaped member 233 Lower back plate 233A Circulation through hole 311 First channel 312 First Fan 321 Second channel 321A Upper duct 321B Duct protrusion 322 Second Fan 411 Compressor 412 Radiation heat exchanger 413 Heat exchanger fan 414 First three-way valve 415 Second aperture section 416 Second heat exchanger 417 Third aperture section 418 First aperture section 419,423 Heat exchanger for drain pan 420 1st heat exchanger 421 Second three-way valve 422 Switching section 431, 432, 433, 435, 436, 437, 438, 439, 440 Piping 434 First Bypass Piping 437A Folding section 437B First branch pipe 437B1 1st outer part 437B2 1st medial part 437C Second branch pipe 437C1 Second outer part 437C2 2nd medial part 441 Second Bypass Piping A1 First cooling air A2 Second cooling air A3 Circulating air B1 1st refrigerant circuit B2 2nd refrigerant circuit C1 First Air Curtain C2 Second Air Curtain P1, P2 connection location Z Goods

Claims

1. A refrigeration device that generates cooling air for cooling articles in a refrigerated storage cabinet, A compressor that compresses the refrigerant being introduced, A heat exchanger for cooling the refrigerant compressed by the compressor, A first throttling section that restricts the refrigerant cooled by the heat exchanger, A first heat exchanger that generates the cooling air by exchanging heat between the refrigerant restricted in the first throttling section and air, The system comprises a drain pan for receiving drain water from the first heat exchanger and a heat exchanger for the drain pan that heats the drain pan by exchanging heat between the heat dissipation heat exchanger and the refrigerant flowing between the first throttling section, The cooling storage unit comprises a freezing storage unit that is cooled to freezing temperature by a first cooling air that constitutes the cooling air, and a refrigerated storage unit that is cooled to refrigeration temperature by a second cooling air that constitutes the cooling air. The aforementioned refrigeration device is A second throttling section restricts the refrigerant flowing between the heat exchanger and the first throttling section, The system further comprises a second heat exchanger that generates the second cooling air by exchanging heat between the refrigerant restricted in the second throttling section and air, The first throttling section restricts the refrigerant cooled by the second heat exchanger. The heat exchanger for the drain pan cools the refrigerant flowing between the second heat exchanger and the first throttling section by heat exchange. The first heat exchanger generates the first cooling air by exchanging heat between the refrigerant narrowed at the first throttling section and the air. Refrigeration equipment.

2. The aforementioned heat exchanger for the drain pan is composed of piping for circulating the refrigerant. The refrigeration apparatus according to claim 1.

3. The part of the piping that constitutes the heat exchanger for the drain pan is located on the lower surface of the drain pan. The refrigeration apparatus according to claim 2.

4. The parts of the piping that constitute the heat exchanger for the drain pan include a first branch pipe and a second branch pipe that are arranged adjacent to each other and connected at one end to one end and at the other end to the other end, respectively. The first branch pipe is configured to guide the refrigerant, which has undergone heat exchange in the second heat exchanger, in a first direction, then guide it in a second direction opposite to the first direction on the second branch pipe side, and then lead it to the first throttling section. The second branch pipe is configured to guide the refrigerant, which has undergone heat exchange in the second heat exchanger, in the first direction, then guide it in the second direction on the first branch pipe side, and finally guide it to the first throttling section. The refrigeration apparatus according to claim 3.

5. A first refrigerant circuit is configured such that the refrigerant compressed by the compressor passes through the compressor, the heat exchanger, the second throttling section, the second heat exchanger, the heat exchanger for the drain pan, the first throttling section, and the first heat exchanger in that order, and returns to the compressor. A second refrigerant circuit is configured such that the refrigerant compressed by the compressor passes through the compressor, the heat exchanger, the first heat exchanger, the first throttling section, the heat exchanger for the drain pan, the second heat exchanger, and the second throttling section in that order, and returns to the compressor. The system further includes a switching unit that switches the refrigerant to flow through the first refrigerant circuit or through the second refrigerant circuit. A refrigeration apparatus according to any one of claims 1 to 4.

6. A first operation control that controls the switching unit so that the refrigerant compressed by the compressor flows through the first refrigerant circuit, thereby generating the first cooling air and the second cooling air, The system further includes a control unit that controls the switching unit so that the refrigerant compressed by the compressor flows through the second refrigerant circuit, thereby generating the second cooling air, and also performs a second operation control to melt the frost on the first heat exchanger. The refrigeration apparatus according to claim 5.

7. The system further includes a third throttling section that restricts the refrigerant flowing between the second heat exchanger and the heat exchanger for the drain pan, The control unit, When performing the first operation control, the first and second throttling sections are controlled to restrict the refrigerant flow, while the third throttling section is controlled not to restrict the refrigerant flow. When performing the second operation control, the third throttling section is controlled to restrict the refrigerant flow, while the first throttling section is controlled not to restrict the refrigerant flow. The refrigeration apparatus according to claim 6.

8. Cooling storage unit, A refrigeration device that generates cooling air for cooling articles in the aforementioned refrigerated storage cabinet, It includes a drain pan for receiving drain water, The aforementioned refrigeration device is A compressor that compresses the refrigerant being introduced, A heat exchanger for cooling the refrigerant compressed by the compressor, A first throttling section that restricts the refrigerant cooled by the heat exchanger, A first heat exchanger that generates the cooling air by exchanging heat between the refrigerant restricted in the first throttling section and air, The system includes a drain pan that receives drain water from the first heat exchanger, a drain pan heat exchanger that heats the drain pan by exchanging heat between the refrigerant flowing between the heat dissipation heat exchanger and the first throttling section, and The cooling storage unit comprises a freezing storage unit that is cooled to freezing temperature by a first cooling air that constitutes the cooling air, and a refrigerated storage unit that is cooled to refrigeration temperature by a second cooling air that constitutes the cooling air. The aforementioned refrigeration device is A second throttling section restricts the refrigerant flowing between the heat exchanger and the first throttling section, The system further comprises a second heat exchanger that generates the second cooling air by exchanging heat between the refrigerant restricted in the second throttling section and air, The first throttling section restricts the refrigerant cooled by the second heat exchanger. The heat exchanger for the drain pan cools the refrigerant flowing between the second heat exchanger and the first throttling section by heat exchange. The first heat exchanger generates the first cooling air by exchanging heat between the refrigerant narrowed at the first throttling section and the air. Storage device.

9. The freezer has an upper opening at the front that allows items to be put in and taken out, The aforementioned refrigerated storage unit has a lower opening at the front that allows items to be put in and taken out, and is positioned below the aforementioned freezer storage unit. The aforementioned storage device is The system further includes an air curtain generating unit that generates a first air curtain using the first cooling air to cool the inside of the freezer storage by covering the upper opening, and a second air curtain using the second cooling air to cool the inside of the refrigerated storage by covering the lower opening. The storage device according to claim 8.

10. The air curtain generating unit is The front side of the upper opening, the lower, rear, and upper sides of the freezer storage unit are configured to be circulated by a first flow path through which the first cooling air and the air constituting the first air curtain circulate. The front side of the upper opening and the lower opening, the lower side of the refrigerated storage unit, the rear side of the refrigerated storage unit and the frozen storage unit, and the upper side of the frozen storage unit are configured to be circulated by a second flow path configured for the circulation of the second cooling air and the air constituting the second air curtain, The first fan is placed on the drain pan, The second flow path further comprises a second fan, which is arranged together with the second heat exchanger, in a portion located above the freezer storage chamber in the second flow path, The drain pan is positioned between the freezer and the refrigerator, so as to constitute the lower portion of the first flow path in the freezer. The first heat exchanger is placed on the drain pan, The first fan is positioned to send the first cooling air obtained by heat exchange in the first heat exchanger to the rear side. The second fan is positioned to send the second cooling air obtained by heat exchange in the second heat exchanger forward. The storage device according to claim 9.

11. The storage device further comprises a lower back plate that separates the internal space of the refrigerated storage cabinet from the portion of the second flow path located at the rear of the refrigerated storage cabinet. The air curtain generating unit is located in the lower part of the second flow path of the refrigerated storage unit and further comprises a third fan that sends the air constituting the second air curtain backward. The heat exchanger for the drain pan is positioned on the lower surface of the drain pan. The lower back plate has through holes formed therein that guide a portion of the air flowing behind the lower back plate, which is supplied by the third fan, to the lower opening via the area below the drain pan and above the refrigerated storage unit. The storage device according to claim 10.

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