JP2008232465A - Storage equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a showcase capable of stably controlling a temperature in a display chamber. <P>SOLUTION: The showcase 1 comprises a first discharge opening 25 for supplying the first cold air A1 to an opening 2 of the display chamber 3, and a second discharge opening 26 for supplying the second cold air A2 of lower temperature to an inner side of the first cold air A1. The first cold air A1 and the second cold air A2 can be produced by a refrigerant cycle 40 including an ejector 60, and both of cooling effect and energy saving effect can be achieved by an air curtain. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a storage device such as a showcase suitable for displaying products in a cooled or frozen state.

  Patent Document 1 describes that energy conversion efficiency is improved by applying an ejector cycle in a refrigeration cycle. For example, the first evaporator is disposed between the refrigerant downstream side of the ejector serving as the refrigerant decompression means and the refrigerant circulation means and the gas-liquid separator, and the liquid refrigerant outlet side of the gas-liquid separator and the refrigerant suction of the ejector An ejector cycle is described in which a second evaporator is placed between the mouth. According to this ejector cycle, the vapor pressure refrigerant discharged from the second evaporator is sucked using the pressure drop caused by the high-speed refrigerant flow during expansion, and the velocity energy of the refrigerant during expansion is Since the refrigerant pressure is increased by converting into pressure energy in the diffuser portion, the driving power of the compressor can be reduced. For this reason, cycle operation efficiency can be improved.

In Patent Document 2, two evaporators are used in an ejector cycle in which a common cooling target air is cooled by combining an ejector downstream-side evaporator (first evaporator) and an ejector suction-side evaporator (second evaporator). It is described that the cooling performance by the vessel is improved. Since the refrigerant evaporation temperature of the second evaporator is lower than the refrigerant evaporation temperature of the first evaporator included in the ejector cycle, the first evaporator is arranged upstream in the flow direction of the air to be cooled, It is described that the second evaporator is disposed on the downstream side in the air flow direction.
JP 2002-318019 A JP 2005-308384 A

  Patent Document 1 describes that separate spaces can be cooled by two evaporators. Patent Document 2 describes cooling common air to be cooled by two evaporators. That is, in Patent Document 2, in an ejector cycle having two evaporators, two evaporators having different refrigerant evaporation temperatures are arranged above and below the air flow so that a common space is created by air that does not have different temperature conditions. It is described to cool.

  However, it is not described that air (cold air) having different temperature conditions is obtained by each evaporator and that the cold air is actively used.

  One embodiment of the present invention is a storage that includes a display chamber that is displayed in a state of being refrigerated and / or frozen, and that is surrounded by a wall so that at least a part of the front and / or upper part is an opening through which the product can be taken in and out. Device. The wall of the display chamber is provided with a discharge portion that blows out cold air so as to form an air curtain in the opening. The storage device further includes a duct for supplying cold air to the discharge unit and a refrigerant cycle for cooling the air in the duct, and the discharge unit discharges the first cold air. An outlet and a second discharge port for blowing out second cold air having a temperature lower than that of the first cold air are provided inside the first cold air.

  In this storage device, an air curtain including an outer first cold air and an inner second cold air that is lower in temperature than the first cold air is formed in the opening of the display chamber. Therefore, since the temperature of the first cold air that contacts the outside air (the air outside the display room) is higher than the temperature of the second cold air inside, even if the first cold air outside the air curtain entrains the outside air, There is little influence on the temperature of the second cold air, and the inside of the display room can be efficiently cooled. Moreover, since the temperature of the 1st cold wind of the outer side of an air curtain is higher than the temperature of the 2nd cold wind of an inner side, even if the 1st cold wind leaks outside, it has little influence on the cooling performance of the interior of a display room. . In addition, since the temperature drop outside the storage device due to the first cold air leaking outside is small, the influence of the cold air leaking from the air curtain on the environment of the store where the storage device is installed can be reduced.

  By making the wind speed of the first cold air discharged from the first discharge port slower than the wind speed of the second cold air discharged from the second discharge port, the entrainment of outside air can be suppressed, and the outside The amount of cold air that leaks can be reduced. On the other hand, the cooling efficiency inside the display chamber can be increased by not reducing the wind speed of the second cold air. An example of a means for making the wind speed of the first cold air discharged from the first discharge port slower than the speed of the second cold air discharged from the second discharge port is the first discharge port and the first It is to change the pressure loss (pressure resistance) of the duct leading to the discharge port. Different fans may be arranged to output the first cold air and the second cold air.

  Examples of means for generating the first cold air and the second cold air having different temperatures are provided with an evaporator having a different heat transfer area, or an evaporator for excessively cooling the second cold air. It is. An ejector cycle including a first evaporator and a second evaporator having different refrigerant evaporation temperatures is a suitable means for generating first and second cold air having different temperatures. That is, the refrigerant cycle of the storage device includes a compressor for sucking and compressing the refrigerant, a radiator for radiating heat of the high-pressure refrigerant discharged from the compressor, and decompressing and expanding the high-pressure refrigerant discharged from the radiator. And an ejector for sucking the refrigerant from the refrigerant suction port, and the air that is connected between the ejector and the compressor, and the air on the side where the first cold air is guided to the first discharge port among the air flowing through the duct. At least the first evaporator arranged to cool, and the radiator is connected between the radiator and the refrigerant suction port of the ejector, and the second cold air is led to the second discharge port among the air flowing through the duct. And a second evaporator arranged to cool the side air.

  FIG. 1 is a sectional view showing a schematic configuration of a storage device according to an embodiment of the present invention. This storage device 1 is an open type frozen showcase suitable for storing and displaying ice cream, frozen foods, etc., and is a flat type (flat rectangular parallelepiped shape) with a floor-standing type and an opening 2 at the top. The center of the housing 10 is a display chamber (storage space, storage area, storage) 3 having a substantially U-shaped cross-section with the top open. The showcase 1 further includes a duct system 20 that supplies cool air A1 and A2 to the display room 3 and sucks air B from the display room 3, and the duct system 20 includes an inner wall that constitutes the display room 3. 5 and the housing 10.

  The duct system 20 includes a supply duct 21 for supplying cool air (supply air) A1 and A2 to the display chamber 3, a suction duct 22 for sucking air (intake air) B from the display chamber 3, and a suction duct 22. A connection duct 23 for connecting the supply duct 21 is provided. The connection duct 23 incorporates evaporators (evaporators) 41 and 42 for cooling the intake air B to generate cool air A1 and A2, and a fan 32 for blowing air. The connection duct 23 extends along the bottom 5b on the opposite side of the bottom 5b of the inner wall 5 constituting the display chamber 3, and the supply duct 21 and the suction duct 22 are the side portions (side walls) 5a and 5c of the inner wall 5. Standing up along. The supply duct 21 and the suction duct 22 are connected to the discharge ports 25 and 26 and the suction port 27 provided in the upper portions of the opposing side walls 5a and 5c, respectively, supply cold air A1 and A2, and air B from the display chamber 3 By sucking the air curtain, an air curtain can be formed in the upper opening of the display chamber 3.

  The showcase 1 further includes a refrigerant cycle (cooling cycle, refrigeration cycle) including a first evaporator (first evaporator) 41 and a second evaporator (second evaporator) 42 disposed in the duct system 20. 40. The refrigerant cycle 40 further includes a compressor (compressor) 45 for sucking and compressing refrigerant supplied to the evaporators 41 and 42, and a radiator (condenser) for releasing heat of the high-pressure refrigerant discharged from the compressor 45. 46. The compressor 45 and the condenser 46 are arranged in a heat radiation section 35 further below the duct system 20 of the showcase 1. Further, the heat radiating section 35 is further provided with a heat radiating fan 31 for introducing outside air to cool the capacitor 46. In addition, the heat radiating section 35 is provided with a drain pan 33 for self-evaporating the drain so that the drain can be received from the connection duct 23 through the drain pipe 39.

  The showcase 1 further has defrosting electric heaters 38 a and 38 b arranged at several locations in the duct system 20. These electric heaters 38a and 38b are arranged in a region where frost or ice is likely to accumulate inside the duct system 20, and are used when performing a defrosting operation for removing frost and / or ice regularly.

  FIG. 2 shows the refrigerant cycle and control configuration of the showcase 1. In addition to the first evaporator 41, the second evaporator 42, the compressor 45 and the condenser 46, the refrigerant cycle 40 of the showcase 1 decompresses and expands the high-pressure refrigerant discharged from the condenser 46 and sucks the refrigerant from the refrigerant suction port 63. It has the ejector 60 for doing. The first evaporator 41 is connected between the ejector 60 and the compressor 45. Of the air flowing through the duct system 20, the side on which the first cold air A1 is guided to the first discharge port 25, that is, the connection duct 23. It arrange | positions so that the air of the outer side (lower side) may be cooled at least. The second evaporator 42 is connected between the condenser 46 and the refrigerant suction port 63 of the ejector 60. Of the air flowing through the duct system 20, the second cold air A 2 is guided to the second discharge port 26. That is, it arrange | positions so that the air inside the connection duct 23 (upper side) may be cooled.

  If the refrigerant used in the refrigerant cycle 40 is a refrigerant whose high pressure does not exceed the critical pressure, such as a fluorocarbon refrigerant, the refrigerant cycle 40 is a subcritical cycle. Therefore, the capacitor 46 serves to condense the refrigerant. On the other hand, if the refrigerant is a refrigerant whose high pressure exceeds the critical pressure, such as carbon dioxide, the refrigerant cycle 40 becomes a supercritical cycle. Therefore, the refrigerant remains supercritical in the capacitor 46 and is not condensed even if liquefied by heat dissipation. The refrigerant cycle 40 of the present specification includes any cycle, and even if it is a supercritical cycle, the radiator is described as a capacitor.

  The refrigerant cycle 40 further includes a receiver 47 disposed downstream (discharge side) of the condenser 46, an accumulator 48 disposed upstream of the compressor 45 (suction side), and a liquid / gas heat exchanger 49. A liquid / gas (liquid vapor) heat exchanger 49 exchanges heat between a high-pressure refrigerant in the liquid phase downstream of the receiver 47 and a low-pressure / low-temperature refrigerant in the gas phase upstream of the accumulator 48. The high-pressure refrigerant is further cooled, and the cooling efficiency by the refrigerant cycle 40 is increased.

  In the refrigerant cycle 40, a part of the liquid refrigerant cooled by the liquid-vapor heat exchanger 49 is guided to the second evaporator 42 via the expansion valve 43, and is evaporated (phase change) by the second evaporator 42. The second cold air A2 is generated. The gas-phase refrigerant output from the second evaporator 42 is guided to the refrigerant suction port 63 of the ejector 60.

  The remaining liquid refrigerant cooled by the liquid-vapor heat exchanger 49 is guided to the nozzle portion 61 of the ejector 60. In the nozzle part 61 of the ejector 60, the high-pressure refrigerant is decompressed and expanded, sucks the gas-phase refrigerant from the refrigerant suction port 63, and blows it out to the diffuser part 62 of the ejector 60. The diffuser portion 62 has a gradually increasing refrigerant passage area, and decelerates the refrigerant flow to increase the refrigerant pressure. Therefore, in the ejector 60, the velocity energy of the refrigerant expanded from the high-pressure refrigerant is converted into pressure energy and output. The refrigerant blown out from the ejector 60 is guided to the first evaporator 41 and is evaporated (phase change) to generate the first cold air A1. The gas-phase refrigerant output from the first evaporator 41 is guided to the compressor 45 through the liquid-vapor heat exchanger 49 and the accumulator 48 and is sucked and compressed.

  Further, the refrigerant cycle 40 includes hot gas bypass valves 65 and 66 for guiding and circulating the refrigerant (hot gas) before being compressed by the compressor 45 and cooled by the condenser 46 to the evaporators 41 and 42. These bypass valves 65 and 66 are opened when the evaporators 41 and 42 are defrosted, and are closed in a normal service state in which cold air is supplied. In FIG. 2, the line (pipe) through which the refrigerant normally flows is indicated by a solid line, whereas the line (pipe) opened and closed by these hot gas bypass valves 65 and 66 is indicated by a broken line.

  The hot gas bypass valve 65 guides the hot gas at the outlet of the compressor 45 to the upstream of the first evaporator 41, that is, to the pipe connecting the ejector 60 and the first evaporator 41. Thus, a line is formed in which hot gas circulates in the forward direction through the first evaporator 41 by the compressor 45.

  The hot gas bypass valve 65 further guides the hot gas at the outlet of the compressor 45 to a pipe connecting the suction port 63 of the ejector 60 and the second evaporator 42 downstream of the second evaporator 42. The hot gas bypass valve 66 connects the upstream side of the second evaporator 42, that is, the pipe connecting the expansion valve 43 and the second evaporator 42 and the suction side of the compressor 45. Thus, a line is formed in which hot gas circulates in the reverse direction through the second evaporator 42 by the compressor 45.

  The showcase 1 further includes a control unit 50 having a function of controlling the fan 32 for blowing, the compressor 45, the fan 31 for exhaust heat, the hot gas bypass valves 65 and 66, and the electric heaters 38a and 38b. The control unit 50 includes a cold air supply control function 51 that controls the cold air supply mode, a defrost control function 52 that controls the defrost mode, and a water drain control function 53 that controls the water drain mode. In the cold air supply mode, as shown in FIG. 2, the blower fan 32, the exhaust heat fan 31 and the compressor 45 are turned on, the hot gas bypass valves 65 and 66 are closed, and the electric heaters 38a and 38b are turned on. Is turned off. Therefore, the air B sucked from the suction port 27 by the suction force of the blower fan 32 is guided to the connection duct 23 through the suction duct 22 and cooled by the evaporators 41 and 42.

  The first evaporator 41 is disposed outside the connection duct 23, and the second evaporator 42 is disposed inside the connection duct 23. The refrigerant cycle 40 includes an ejector 60. Therefore, the internal pressure of the second evaporator 42 on the side where the refrigerant is sucked by the ejector 60 is lower than the internal pressure of the first evaporator 41, and the evaporation temperature of the refrigerant in the second evaporator 42 is Lower than the evaporation temperature of the refrigerant in the evaporator 41. For this reason, the second cold air (cold air) A2 generated by the second evaporator 42 is lower in temperature than the first cold air (cold air) A1 generated by the first evaporator 41.

  Guides (vanes) 24a and 24b that guide the first cold air A1 to the outside and the second cold air A2 to the inside are attached to the connection duct 23 and the supply duct 21 at least at locations where the direction of the cold air changes. Yes. Accordingly, the first cold air A <b> 1 cooled by the first evaporator 41 is supplied to the display chamber 3 through the supply duct 21 from the outer discharge port 25 to the display chamber 3. On the other hand, the second cold air A <b> 2 cooled by the second evaporator 42 is supplied to the display chamber 3 through the supply duct 21 from the inner discharge port 26 to the display chamber 3. Therefore, the second cold air A2 is blown out from the inside of the first cold air A1. Instead of partially installing guides inside the connection duct 23 and the supply duct 21, the insides of these ducts can be completely separated, or the first cold air A1 and the second cold air A2 can be separately supplied. It is also possible to provide a duct.

  When these cold air A1 and A2 are sucked from the suction port 27 as the intake air B, an air curtain is formed in the opening 2 by two layers of cold air of the cold air A1 and A2 having different temperatures. That is, the outer cold air A1 is caused to function as a secondary flow layer for forming an air curtain by the inner cold air A2. The first cold air A1 flowing outside the connection duct 23 and the supply duct 21 has a larger pressure loss than the second cold air A2 flowing inside these ducts. For this reason, in many cases, the wind speed of the first cold air A1 blown from the discharge port 25 is slower than the wind speed of the second cold air A2 blown from the discharge port 26, and the first cold air A1 It is blown out under conditions preferable as a fluidized bed. In this showcase 1, a damper 28 whose opening area can be adjusted is disposed in the vicinity of the discharge port 25, and the speed and amount of the first cold air A <b> 1 blown out from the discharge port 25 are in a more preferable range as a side flow. I can control it. It is also possible to dispose a damper in the vicinity of the discharge port 26 so that the speed, amount, and ratio of the first cold air A1 and the second cold air A2 can be controlled in more detail.

  For example, in this refrigeration showcase 1, the difference between the temperature at the time of blowing out the first cold air A1 as a side flow and the temperature at the time of blowing the second cold air A2 for the air curtain is about 5 ° C. . As an example of the blowing temperature in the refrigeration showcase 1, the temperature at the time of blowing the first cold air A1 as a side flow is about −25 ° C., and the temperature at the time of blowing the second cold air A2 for the air curtain is − It is about 30 ° C. In the refrigerant cycle (refrigeration cycle) 40 that generates cold air by two evaporators using the ejector 60, the cold air A1 and A2 having such a temperature difference can be efficiently generated. Therefore, by using the cold air A1 having a higher temperature as a stable side flow, it is possible to prevent the outside air (outside air) from being caught and to reduce the heat load of the outside air, thereby obtaining the maximum air curtain effect. be able to. That is, the greater the difference between the air curtain temperature and the outside temperature, the greater the effect of lowering the cooling efficiency due to the entrainment of outside air. Therefore, by providing a subflow layer having a temperature higher than the air curtain temperature on the outside of the air curtain, it is possible to suppress a decrease in efficiency due to the entrainment of outside air.

  In addition, the cold air forming the air curtain entrains outside air and leaks out of the cabinet (outside of the showcase 1 and outside) to cool the outside of the cabinet. Therefore, the temperature in the store where the showcase 1 is installed may decrease locally and affect air conditioning. By providing a high temperature side flow layer on the outside of the air curtain, the temperature of the cold air leaking out of the warehouse can be raised, so that the influence on the air conditioning in the store can also be suppressed.

  FIG. 3 shows the refrigerant cycle in the defrosting mode. In the defrost mode, the defrost control function 52 stops the blower fan 32, drives the exhaust heat fan 31 and the compressor 45, and opens the hot gas bypass valves 65 and 66 to heat the evaporators 41 and 42. . In the refrigerant cycle shown in FIG. 3, a line (pipe) through which hot gas flows is indicated by a solid line. Further, by turning on (energizing) the electric heaters 38 a and 38 b, a place where frost formation or icing is likely to occur such as the bottom surface 23 b of the connection duct 23 and the vicinity of the suction port 27 is heated. Frost or ice adhering to and / or depositing on the evaporators 41 and 42 is melted and drained, passes through the bottom surface 23b of the connection duct 23, is collected in the drain pan 33 through the drain pipe 39, and is evaporated. Further, frost or ice adhering to and / or depositing on the suction duct 22 and the connection duct 23 is melted and drained. At this time, since the blower fan 32 is stopped, the air flow (forced flow) inside the duct system 20 including the suction duct 22, the connection duct 23, and the supply duct 21 stops, and the display chamber 3 has no duct. Neither cold air nor hot air is supplied from the system 20.

  The defrost control function 52 melts frost and / or ice by the above control for a predetermined time, for example, about 15 minutes. Thereafter, the mode is switched to the draining mode, and the draining control function 53 stops the compressor 45, closes the hot gas bypass valves 65 and 66, turns off the electric heaters 38a and 38b, and drives the blower fan 32 for 2 minutes. Drain the water to the extent. Thereafter, the flow again enters the cold air supply mode. As a result, cool air A1 and A2 are supplied from the duct system 20 to the display chamber 3, an air curtain is formed in the opening 2 in the same manner as described above, and the display chamber 3 is cooled. This showcase 1 keeps the inside of the display chamber 3 at a low temperature by repeating a cold air supply mode of 8 hours, a defrosting mode of about 15 minutes, and a draining mode of about 2 minutes.

  FIG. 4A shows the on / off state of each device described above. FIG. 4B shows how the cold air supply mode 55, the defrosting mode 56, and the draining mode 57 transition in the control method of the showcase 1. When the showcase 1 is started, first, the cold air supply mode 55 is set. In this mode, the cool air supply control function 51 turns on the compressor 45 and the blower fan 32. Therefore, the refrigerant cycle 40 including the ejector 60 moves, and the cold air cooled by the evaporators 41 and 42 is supplied from the duct system 20 to the display chamber 3.

  When a predetermined service time T1, for example, 8 hours elapses, the defrosting mode 56 is entered. The timing for shifting to the defrosting mode 56 may be managed by the service time T1, or may be managed by factors such as a decrease in the amount of cold air supplied from the supply duct 21. In the defrost mode 56, the blower fan 32 is stopped by the defrost control function 52, the hot gas bypass valves 65 and 66 are opened, and the heaters 38a and 38b are turned on. Therefore, due to the hot gas and the heat of the heaters 38a and 38b, portions where frost or ice easily adheres or accumulates, that is, the evaporators 41 and 42 and a predetermined portion of the duct system 20 generate heat and the temperature rises. Melt frost or ice adhering to the part.

  In the defrost mode 56, the blower fan 32 is stopped by the defrost control function 52 of the control unit 50. By forcibly stopping the blower fan 32, hot air is not supplied to the display chamber 3 even if the temperature is suddenly raised inside the connection duct 23 during defrosting. For this reason, the evaporators 41 and 42 can be rapidly heated by hot gas, and the portion of the connection duct 23 where frost easily adheres and / or accumulates can be rapidly heated by the electric heaters 38a and 38b. Accordingly, the portion where frost and / or ice is attached or deposited can be concentrated and heated to rapidly melt the frost and / or ice. For this reason, time (defrosting time) T2 of a defrosting operation can be shortened.

  When defrosting time T2, for example, 15 minutes elapses, the process proceeds to draining mode 57. In the draining mode 57, the blower fan 32 is turned on by the draining control function 53, the compressor 45 is turned off, and the hot gas bypass valves 65 and 66 and the heaters 38a and 38b are also turned off. Therefore, since the refrigerant cycle 40 does not operate, it is not cooled or heated, and the heater does not generate heat. In this state, only air circulates through the duct system 20 and drains water. When the draining time T3, for example, 2 minutes elapses, the process proceeds to the cold air supply mode 55. Therefore, the refrigerant cycle 40 is moved again, and the cool air A1 and A2 cooled by the evaporators 41 and 42 are supplied from the duct system 20 to the display chamber 3 to form an air curtain.

  FIG. 5 is an enlarged sectional view of a part of the evaporators 41 and 42. The evaporators 41 and 42 are spine fin type heat exchangers in which a tube (spine fin tube) 79 provided with a spine fin 74 is bent in a direction crossing the connection duct 23 to form a plurality of pipe portions 76. Therefore, from each tube main body 72, the spine fin 74 of the shape interrupted in the longitudinal direction and the circumferential direction protrudes in the radial direction. The spine fin tube 79 can be manufactured by cutting a plate material into a strip shape, and winding a band-like member obtained by bending the plate material into a bowl shape around the tube body 72 as a fin 74 and joining them.

  The distance between the spine fins 74 is narrow at the root (the tube body 72 side) and wide at the tip. Therefore, in the evaporators 41 and 42 adopting the spine fin tube 79, even if frosting or icing progresses, the tips of the fins 74 are widened so that they are not easily blocked, and a decrease in the amount of cold air can be prevented. Furthermore, since the tips of the fins 74 are widened when rapidly heated with hot gas, frost or ice that has melted away from the tube main body 72 is easily separated from the fins 74. Therefore, frost or ice that has melted away from the tube, such as plate fins or corrugated fins, is sandwiched between the fins, and it is rarely difficult to improve the air volume. For this reason, it can heat rapidly by flowing hot gas to the evaporators 41 and 42, and can defrost in a short time. Further, even if the temperatures of the evaporators 41 and 42 are increased, the blower fan 32 is stopped, so that the heated air does not flow into the display chamber 3, the frozen food in the display chamber 3 melts, or the ice cream Softening can be prevented.

  As described above, the refrigerant cycle 40 including the ejector 60 and the two evaporators 41 and 42 can generate cold air having different temperatures and has high cooling efficiency, so that an air curtain including a side flow can be formed. Combined with the merit of energy saving. In the above system, the first evaporator 41 and the second evaporator 42 are arranged separately on the inner side and the outer side of the connection duct 23, but a part of the cold air cooled by the first evaporator 41 is used in the first system. It is also possible to employ an arrangement in which cooling is performed by the two evaporators 42. By further cooling the air cooled by the first evaporator 41 by the second evaporator 42, the cold air A2 having a lower temperature can be generated. Further, the number of mounted evaporators 41 and 42 is not limited to two.

  It is also possible to generate the cold air A1 and A2 having different temperatures using a refrigerant cycle (refrigeration cycle) other than the refrigerant cycle including the ejector 60. For example, cold air having different temperatures can be generated by providing adjustment valves for adjusting the pressures in the plurality of evaporators to control the evaporation temperature of the refrigerant in the evaporator.

  Furthermore, in the above description, the present invention has been described by taking a flat open showcase as an example. However, the present invention is not limited to a flat type, and may be an open showcase having a front opened.

Sectional drawing which shows schematic structure of a flat type showcase. It is a figure which shows the refrigerant cycle and system configuration | structure of the showcase shown in FIG. 1, and is a figure for demonstrating the state (cold air supply mode) of cold air supply. It is a figure which shows the refrigerant cycle and system configuration | structure of the showcase shown in FIG. 1, and is a figure for demonstrating the state (defrost mode) of a defrost. FIG. 4A shows the on / off status of the device in each mode, and FIG. 4B shows the transition to each mode. Sectional drawing which expands and shows the structure of an evaporator.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Showcase, 3 Display room (storage area), 5 Inner wall of display room 10 Housing 20 Duct system, 21 Supply duct, 22 Suction duct, 23 Connection duct 25, 26 Discharge port, 27 Suction port 31 Fan for exhaust heat, 32 Fan for blowing air (Blower fan)
40 Refrigerant cycle, 41, 42 Evaporator 45 Compressor, 46 Condenser, 60 Ejector 50 Control unit

Claims (3)

The product is displayed in a refrigerated and / or frozen state, and has a display room surrounded by a wall so that at least a part of the front and / or upper part is an opening through which the product can be taken in and out. The wall is provided with a discharge part that blows out cold air so as to form an air curtain in the opening, and
A duct for supplying cold air to the discharge part;
A storage device having a refrigerant cycle for cooling the air in the duct,
The discharge section has a first discharge port for blowing out first cold air, and a second discharge port for blowing out second cold air lower in temperature than the first cold air inside the first cold air. And a storage device.   2. The storage device according to claim 1, wherein a wind speed of the first cold air discharged from the first discharge port is slower than a wind speed of the second cold air discharged from the second discharge port. The refrigerant cycle according to claim 1 or 2, wherein:
A compressor for sucking and compressing refrigerant;
A radiator for radiating heat of the high-pressure refrigerant discharged from the compressor;
An ejector for decompressing and expanding the high-pressure refrigerant discharged from the radiator and sucking the refrigerant from the refrigerant suction port;
First, connected between the ejector and the compressor, and arranged to cool at least air on a side of the air flowing through the duct to which the first cold air is guided to the first discharge port. With an evaporator,
It is connected between the radiator and the refrigerant suction port of the ejector, and is arranged so as to cool the air on the side where the second cold air is guided to the second discharge port among the air flowing through the duct. And a second evaporator.

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