JP2009236446A - Showcase - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a showcase for smoothly defrosting an evaporator while minimizing temperature change in a display chamber. <P>SOLUTION: This showcase 1 includes the display chamber 8, a plurality of cooling devices R1, R2 respectively composed of a cooling circuit 16 composed of a compressor 24, a radiator 22, a pressure reducing device 20, the evaporator 19 and the like, and a blower 18 for supplying the cold air exchanging heat with the evaporator 19 into the display chamber 8, and a control device C for controlling operations of the cooling devices, the cooling device C continues the cooling operation by the other cooling device when the evaporator 19 of either of the cooling devices R1, R2 is defrosted, and increases a rotational frequency of the blower and a rotational frequency of the compressor of the other cooling device. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a showcase for selling products while cooling products such as food in a display room.

  Conventionally, this type of showcase has been installed in stores such as supermarkets and convenience stores, and is used for display and sale of various foods. For example, in a showcase as shown in Patent Document 1, an evaporator and a blower are disposed in each of an inner layer duct and an outer layer duct, and circulating air passing through each of the inner layer duct and the outer layer duct is cooled to form two layers in the opening. An air curtain is formed.

In such a showcase, since a large opening is formed on the front surface, outside air containing a lot of moisture is easily taken into the display chamber, and remarkable frost formation occurs in the evaporator. Therefore, in order to remove the frost, a defrosting operation is performed in which the high-temperature and high-pressure refrigerant (hot gas) discharged from the compressor flows into the evaporator every certain period.
Japanese Unexamined Patent Publication No. 64-46562

  At this time, since the circulating air passing through the duct has no cold heat source, the temperature of the circulating air and the air in the display chamber rises, and an unfavorable situation occurs for the commodity to be stored. Therefore, in the conventional showcase, an increase in the temperature in the display room during the defrosting operation is predicted, excessive cooling is performed to lower the display room temperature below the set temperature, and the display room temperature is reduced during the defrosting operation. The inconvenience that the temperature rises higher than the set temperature was avoided.

  However, in such a configuration, since the temperature in the display room is once greatly lowered from the set temperature, depending on the type of product to be displayed and the display position of the product, the quality of the product can be reduced by freezing the refrigerated product. There was a problem that caused the deterioration.

  Therefore, it is conceivable to provide a plurality of cooling devices for cooling the same display room. For example, a cooling device has been developed in which carbon dioxide, which is a natural refrigerant, is sealed as a refrigerant in a refrigerant pipe constituting the cooling device, and the high pressure side is operated at a supercritical pressure. In this case, the refrigerant pipe has a remarkably high pressure as compared with the case where chlorofluorocarbon gas is used as the refrigerant, so that the cooling apparatus including the evaporator is disposed in the showcase body as a unit.

  Therefore, the drain water discharged from the evaporator constituting each cooling device is subjected to an evaporation process in the drain evaporation device configured integrally with any one of the cooling devices. However, if the drain water flows into only one drain evaporator depending on the installation situation, the treatment load in the drain evaporator increases, and smooth drain water treatment cannot be performed, while the other drain evaporator In the apparatus, since drain water does not flow in, the evaporation capacity is surplus.

  The present invention has been made to solve the conventional technical problem, and provides a showcase capable of smoothly defrosting an evaporator while minimizing temperature changes in the display chamber as much as possible. .

  The showcase of the present invention supplies a display room configured in a heat insulating wall, a refrigerant circuit configured by a compressor, a radiator, a decompression device, an evaporator, and the like, and cold air exchanged heat with the evaporator into the display chamber. A plurality of cooling devices composed of a blower and a control device that controls the operation of each cooling device. When the control device defrosts the evaporator of any of the cooling devices, the other cooling device The cooling operation by the apparatus is continued, and the rotation speed of the blower and / or the rotation speed of the compressor of the other cooling apparatus is increased.

  In the showcase of the invention of claim 2, in the above invention, when the temperature in the display chamber is higher than a predetermined value, the control device stops the cooling operation of the cooling device for defrosting the evaporator and operates only the blower The off-cycle defrosting is performed, and when the temperature in the display room is equal to or lower than a predetermined value, the blower of the cooling device that performs defrosting of the evaporator is stopped.

  A showcase according to a third aspect of the present invention, in each of the above-mentioned inventions, is configured between the rear plate of the display chamber whose front is open and the heat insulating wall, a duct in which the evaporator and the blower of each cooling device are installed, A cool air discharge port and a cool air suction port formed above and below the front opening, a partition plate provided with a plurality of vent holes provided in a duct on the cool air outlet side of each evaporator, and a space between the partition plate A partition plate provided between the evaporators, a closing plate that covers the front surface of each evaporator and is provided with a space between the rear plate and the partition plate, and a rear blower formed on the partition plate. And an outlet.

  According to a fourth aspect of the present invention, there is provided the showcase according to any one of the above-mentioned inventions, wherein the control device has temperature sensors that respectively detect the temperatures of the regions in the display chamber cooled by the evaporator of each cooling device. Rotational speed control of the compressor is started on the condition that the temperature detected by reaches the set value.

  According to the showcase of the present invention, the display chamber configured in the heat insulating wall, the refrigerant circuit configured by the compressor, the radiator, the decompression device, the evaporator, and the like, respectively, and the cold air heat-exchanged with the evaporator are displayed in the display chamber. A plurality of cooling devices composed of a blower for supplying the cooling device, and a control device for controlling the operation of each cooling device, the control device, when defrosting the evaporator of any of the cooling devices, The cooling operation by the other cooling device is continued, and the defrosting of any evaporator is performed by increasing the rotational speed of the blower and / or the rotational speed of the compressor of the other cooling device. The cooling capacity that decreases in the entire case can be compensated for by continuing the cooling operation by another cooling device and increasing the rotational speed of the blower and / or the rotational speed of the compressor.

  As a result, the temperature rise in the display room due to the effect of defrosting can be minimized as much as possible, and the power consumption of the entire showcase can be reduced.

  According to invention of Claim 2, in the said invention, when the temperature in a display room is higher than predetermined value, a control apparatus stops the cooling operation of the cooling device which defrosts an evaporator, and drives only a fan. When off-cycle defrosting is performed and when the temperature in the display room is equal to or lower than a predetermined value, the blower of the cooling device that performs defrosting of the evaporator is stopped, so the defrosting mode is changed according to the temperature in the display room As a result, a more efficient defrosting operation can be realized, and a temperature rise in the display room can be suppressed as much as possible.

  According to invention of Claim 3, in said each invention, it is comprised between the backplate and heat insulation wall of the display chamber which a front surface opens, and the duct in which the evaporator and fan of each cooling device are installed, and the front surface of a display chamber A cold air discharge port and a cold air suction port formed above and below the opening, a partition plate provided with a plurality of vent holes provided in a duct on the cold air outlet side of each evaporator, and a gap with the partition plate A partition plate provided between the evaporators, a closing plate that covers the front surface of each evaporator and is provided with a space between the back plate and the partition plate, and a rear outlet formed in the partition plate Therefore, the cold air exchanged heat in each evaporator is discharged from the space between the partition plate and the partition plate, and a part of the cold air is discharged from the vent hole of the partition plate upward in the duct. A part of the remaining cold air flows out from the gap between the back plate and the closing plate to the lower part of the duct. It can be supplied to cold air in the display chamber from the rear air outlet formed.

  At this time, the cold air exchanged with each evaporator is stirred and mixed in the duct with the cold air exchanged with other evaporators. As a result, the temperature of the cool air supplied into the display room can be made uniform, and uneven cooling of the display room can be prevented. In particular, since the cool air discharged upward in the duct is discharged through the ventilation holes of the partition plate, it is possible to obtain the effect of stirring the cool air discharged from each evaporator.

  According to the invention of claim 4, in each of the above-mentioned inventions, the control device has a temperature sensor for detecting the temperature of the area in the display chamber cooled by the evaporator of each cooling device, and all the temperature sensors are Compressor speed control is started on the condition that the detected temperature has reached the set value, so use the ability of the cooling device in the cold area first to help cool the cold area. Is possible.

  As a result, the entire display room can be efficiently cooled, and the entire display room can be cooled to the set temperature at an early stage.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 shows a vertical side view of a showcase 1 to which the present invention is applied. The showcase 1 of the present embodiment has a main body composed of a heat insulating wall 6 having a substantially U-shaped cross section and side plates 7 and 7 attached to both sides of the heat insulating wall 6. A back plate 4 is attached to the inside of the heat insulating wall 6 with a space therebetween. Between the back plate 4 and the heat insulating wall 6, a duct 5 in which an evaporator 19 constituting the cooling device R is provided vertically is provided. A compartment is formed.

  A bottom plate 10 is attached in front of the lower end of the back plate 4 with a space for forming a duct 5 between the bottom wall 6A of the heat insulating wall 6 and is displayed inside the back plate 4 and the bottom plate 10. The chamber 8 is partitioned. A cold air discharge port 14 provided with a honeycomb material 13 is formed at the upper edge of the front opening 12 of the heat insulating wall 6, and the cold air discharge port 14 communicates with the duct 5. A cold air inlet 15 is formed at the lower edge of the opening 12. Further, a plurality of shelves 9... For displaying merchandise are installed in the display room 8 in the vertical direction.

  Next, the cooling device R will be described with reference to FIGS. 2 is a perspective front view of the showcase 1 showing the schematic arrangement of the evaporator and the cooling device, FIG. 3 is a refrigerant circuit diagram of the cooling device R1, FIG. 4 is a partial perspective view of the showcase 1, and FIG. 6 is a front view of FIG. 4, FIG. 7 is a plan view of FIG. 4, FIG. 8 is a vertically enlarged side view of the lower part of the showcase 1, FIG. 9 is a plan view of the cooling device R1, and FIG. The front view of R1 is shown, respectively. In the showcase 1 according to the present invention, a plurality of cooling devices R, in this embodiment, two cooling devices R1 and R2 are arranged side by side. In this embodiment, the number of cooling devices R provided in one showcase 1 is two. However, the number of cooling devices R is not limited to this and may be three or more.

  In each of the cooling devices R1 and R2, a refrigerant circuit 16 is configured by connecting a compressor 24, a radiator 22, a decompression device 20 such as a capillary tube or an electronic expansion valve, an evaporator 19 and the like in an annular manner by a refrigerant pipe. Yes. In FIG. 3, the cooling device R1 is illustrated, but the cooling device R2 has the same configuration, and thus the description thereof is omitted.

  The refrigerant discharge pipe 42 of the compressor 24 is connected to the inlet of the radiator 22 through the evaporation pipe 43. Here, the compressor 24 of the embodiment is an internal intermediate pressure type two-stage compression rotary compressor, and an electric element as a driving element in the hermetic container, and first and second rotations driven by the electric element. It is composed of compression elements.

  One end of the refrigerant introduction pipe 44 for introducing the refrigerant into the first rotary compression element of the compressor 24 is in communication with the cylinder of the first rotary compression element, and the other end is a low pressure of the internal heat exchanger 41. It is connected to the outflow side of the side channel 41A. On the other hand, the refrigerant introduction pipe 45 for introducing the refrigerant compressed by the second rotary compression element of the compressor 24 into the second rotary compression element passes through the intermediate cooling circuit 50 outside the compressor 24. Is provided. The intermediate cooling circuit 50 is provided with a heat exchanger 22A for cooling the refrigerant compressed by the first rotary compression element, and the intermediate pressure refrigerant compressed by the first rotary compression element is After being cooled by the heat exchanger 22A, the second rotary compression element is sucked. The heat exchanger 22A is formed integrally with the radiator 22, and the heat exchanger 22A and the radiator 22 are air-cooled by the radiator fans 25 and 25.

  On the other hand, the refrigerant pipe 46 connected to the outlet side of the radiator 22 is connected to the inflow side of the high-pressure side passage 41 </ b> B of the internal heat exchanger 41. In the internal heat exchanger 41, the low-pressure side channel 41A and the high-pressure side channel 41B are provided in a heat exchange manner, whereby the high-pressure side refrigerant and the evaporator 19 (in this case) discharged from the radiator 22 19A In the case of the cooling device R2, heat exchange is performed with the low-pressure side refrigerant discharged from the evaporator 19B). And the refrigerant | coolant piping 47 connected to the exit side of the high voltage | pressure side flow path 41B is connected to the evaporator 19A via the decompression device 20. FIG. The refrigerant pipe 48 connected to the outlet side of the evaporator 19 </ b> A is connected to the inlet side of the low-pressure side passage 41 </ b> A of the internal heat exchanger 41 and connected to the suction side of the compressor 24 via the refrigerant introduction pipe 44. Has been.

  Note that the refrigerant sealed in the refrigerant circuit 16 is non-flammable and non-corrosive, does not destroy ozone, and has a warming coefficient that is one-thousandth that of a fluorocarbon refrigerant. Is used, and the high pressure side of the refrigerant circuit has a supercritical pressure. Therefore, the cooling devices R1 and R2 constituting the refrigerant circuit 16 are subjected to a refrigerant leak inspection at the time of shipment in a state where they are integrally configured as a cooling unit.

  On the other hand, the evaporators 19 </ b> A and 19 </ b> B are arranged side by side in a duct 5 formed between the back plate 4 and the back surface of the heat insulating wall 6 as described above. Below the bottom plate 10, fan cases 17 and 17 are installed on the left and right sides of the bottom wall 6A of the heat insulating wall 6. Each fan case 17 and 17 has a cool air circulation blower corresponding to each of the evaporators 19A and 19B. 18A and 18B are attached. 4, 6 and 7, the left side shows a state where the back plate 4 is removed, and the fan case 17 and the blower 18 </ b> B are omitted.

  A partition plate 26 is provided in the duct 5 on the cold air outlet side of each of the evaporators 19A and 19B. As shown in FIGS. 4 and 6, the partition plate 26 has a plurality of vent holes 26A formed by punching. A partition plate 27 is provided between the evaporators 19A and 19B with a predetermined distance from the partition plate 26. Thereby, the bias of the circulating air heat-exchanged in each of the evaporators 19A and 19B is suppressed.

  Further, a closing plate 28 is provided to cover the front surfaces of the evaporators 19A and 19B with a predetermined space between the back plate 4 and the partition plate 26. A plurality of rear outlets 29 are formed in the lower part of the rear plate 4 so as to be located on the front side of the closing plate 28. Thereby, it is set as the structure which can discharge a part of cool air which distribute | circulates the inside of the duct 5 in the display chamber 8 directly.

  Therefore, the cold air heat-exchanged with the respective evaporators 19A or 19B in the duct 5 surrounded between the partition plate 27, the closing plate 28, and the back surface of the heat insulating wall 6 is sent from the rear of each closing plate 28, 28. While being able to positively send out the cool air upward, a part of the cool air is branched at the interval between the upper ends of the closing plates 28, 28 and the partition plate 26 and lowered to the front side of the evaporators 19A, 19B. Cold air can be discharged from the front rear outlet 29 into the display chamber 8. A decompressor 20 is connected to the refrigerant inflow side of the evaporators 19A and 19B.

  Then, the cold air discharged through the air holes 26A of the partition plate 26 located on the cold air outlet side of the evaporators 19A and 19B and discharged upward in the duct 5 passes through the air holes 26A, thereby evaporating the other. The mixture is stirred and mixed with the cold air exchanged with the vessel 19A or 19B. The inside of the duct 5 is raised and discharged from the cold air discharge port 14 where the honeycomb material 13 is provided toward the display chamber 8.

  Thereby, the cold air heat-exchanged in the evaporators 19A and 19B is made uniform in the temperature of the cold air in the process of passing through the vent hole 26A, and the difference in the cold air temperature blown out in the entire display chamber 8 can be eliminated. Uneven cooling can be prevented.

  And as mentioned above, the drain pan D which receives the drain water from each evaporator 19A, 19B is provided in the bottom wall 6A upper surface of the heat insulation wall 6 in which the fan cases 17 and 17 are provided. On the upper surface of the drain pan D, a drain partition plate 32 that partitions the region on the drain pan D into a region corresponding to the evaporator 19A side and a region corresponding to the evaporator 19B is provided.

  In the drain pan D, a drain hole 34A is formed in the region on the cooling device R1 side partitioned by the drain partition plate 32, and a drain hole 34B is formed in the region on the cooling device R2 side partitioned by the drain partition plate 32. The drain holes 34A and 34B are connected to drain pipes 33A and 33B for discharging drain water to the drain evaporators 3 of the corresponding cooling devices R1 and R2, respectively.

  In the present embodiment, the drain pan D has a bottom surface formed low toward the drain holes 34A and 34B, and the drain water received on the drain pan D is smoothly guided to the drain holes 34A and 34B. Yes.

  On the other hand, the machine room 2 is formed on the base 21 below the bottom wall 6 </ b> A of the heat insulating wall 6. In the machine room 2, the radiator 22 of each cooling device R <b> 1, R <b> 2 is installed on the base 21 at a front portion, and a radiator fan 25 is attached to the rear side thereof. A drain evaporator 3 is installed on the base 21 behind the radiator fan 25, and the compressors 24 of the cooling devices R 1 and R 2 are on the base 21 at the side of the radiator 22 in the machine room 2. It is installed. Note that an electrical box 31 having a control panel 30 and a control device C is disposed on the side of the radiator 22 so as to face the front of the machine room 2.

  The drain evaporator 3 is configured to include two evaporating dishes 52 and 52 that are held by vertical columns 51 at a predetermined interval in the vertical direction. Each evaporating dish 52 has a rectangular shape with a predetermined depth, and the evaporating pipe 43 is disposed in a heat exchange manner.

  Each evaporating dish 52 is provided with an evaporating plate 53 for allowing drain water to permeate and easily diffuse from the surface thereof. In the present embodiment, uni-bex (trade name) is used as an example of the evaporation plate 53. This is formed by using a non-woven fabric such as polyester fiber as a base material, heat-curing fine phenol on the base material to form a fixing agent, further imparting hydrophilicity and immersing in an alcohol-based solvent, followed by drying. Is. In addition, the overflow pipe | tube 54 shall be attached to the evaporating dish 52 located in an upper side.

  Next, the control device C of the showcase 1 of the present embodiment will be described with reference to an electric block diagram of the control device C of FIG. The control device C is configured by a general-purpose microcomputer having a clock function inside, and a control panel 30 having various setting switches and a display unit is connected to the control device C. On the input side of the control device C, the inside temperature sensor 35A for detecting the temperature of the region in the display chamber 8 that is mainly cooled by the evaporator 19A of the cooling device R1, and the cooling by the evaporator 19B of the cooling device R2 are mainly used. An in-chamber temperature sensor 35B for detecting the temperature of the area in the display room 8 is connected.

  On the other hand, on the output side of the control device C, a compressor motor 24MA that drives the compressor 24 of the cooling device R1, a compressor motor 24MB that drives the compressor 24 of the cooling device R2, and a cold air circulation on the cooling device R1 side. A blower motor 18MA for driving the blower 18A, a blower motor 18MB for driving the cooler circulation fan 18B on the cooling device R2, a blower motor 25M, 25M for driving the radiator fan 25 of each cooling device R1, R2, and the like. It is connected.

  Here, the compressor motors 24MA and 24MB are connected via the inverter devices 36 and 36, respectively, so that the operating frequencies of the compressor motors 24MA and 24MB can be arbitrarily changed. Further, the blower motors 18MA and 18MB of each cool air circulation blower are connected via a drive circuit 37 such as a chopper circuit, whereby the rotational speed of the blower motors 18MA and 18MB can be arbitrarily changed. . Similarly, the blower motors 25M and 25M of the radiator blower are connected via a drive circuit 38 such as a chopper circuit, whereby the rotational speed of the blower motors 25M and 25M can be arbitrarily changed.

  The control operation of the showcase 1 with the above configuration will be described. First, the control device C sets the cooling set temperature based on an input operation by the control panel 30 or the like. Based on this, the control device C controls the operation of the compressors 24 and 24 and the cooling air circulation fans 18A and 18B of the cooling devices R1 and R2. When the compressor 24 is operated, the low-pressure refrigerant gas is sucked into the first rotary compression element of the compressor 24 and compressed, becomes an intermediate pressure, and is discharged into the sealed container. The refrigerant discharged into the sealed container is temporarily discharged from the refrigerant introduction pipe 45 to the outside of the sealed container, enters the intermediate cooling circuit 50, and passes through the heat exchanger 22A. Therefore, the refrigerant dissipates heat by receiving ventilation from the blower.

  Thereafter, the refrigerant is sucked into the second rotary compression element and compressed, becomes a high-temperature and high-pressure refrigerant gas, and is discharged from the refrigerant discharge pipe 42 to the outside of the compressor 24. At this time, the refrigerant is compressed to an appropriate supercritical pressure.

  The refrigerant discharged from the refrigerant discharge pipe 42 flows into the radiator 22 through the evaporation pipe 43 provided in the drain evaporator 3, dissipates heat in the evaporation pipe 43 and the radiator 22, and then performs internal heat exchange. Flows into the high-pressure channel 41B of the vessel 41. Here, since the high-pressure side flow path 41B and the low-pressure side flow path 41A are arranged in a heat exchange manner, the refrigerant from the radiator 22 flowing through the high-pressure side flow path 41B flows through the low-pressure side flow path 41A. The refrigerant from 19 is deprived of heat and cooled.

  Thereafter, the refrigerant cooled by the internal heat exchanger 41 and flowing out from the high-pressure channel 41 </ b> B reaches the decompression device 20. At the inlet of the decompression device 20, the refrigerant gas is still in a gaseous state. The refrigerant is made into a gas / liquid two-phase mixture due to a pressure drop in the decompression device 20, and flows into the evaporator 19 (19A, 19B) in that state. Therefore, the refrigerant evaporates to exert a cooling action and cool the air in the duct 5.

  Thus, since the cool air circulation fans 18A and 18B are in operation, the cool air exchanged with the respective evaporators 19A and 19B is raised in the duct 5 toward the cool air suction port 15 from the cool air discharge port 14. Discharged. At this time, the cold air is stirred and mixed with the cold air heat-exchanged with the other evaporator 19A or 19B by passing through each vent 26A of the partition plate 26 located on the cold air outlet side of the evaporators 19A and 19B. . Therefore, the temperature of the cold air can be made uniform, the difference in the cold air temperature blown out in the entire display chamber 8 can be eliminated, and the uneven cooling can be prevented.

  Further, a part of the cool air heat-exchanged with the evaporator 19A or 19B is branched from the gap between the closing plate 28 and the partition plate 26 at the interval between the upper end of the closing plates 28 and 28 and the partition plate 26, and is evaporated. The cool air can be discharged into the display chamber 8 directly from the front rear outlet 29 by being lowered to the front side of the containers 19A and 19B.

  Then, the cold air sucked from the cold air inlet 15 is again accelerated by the respective cold air circulation fans 18A and 18B. As a result, a cool air curtain is formed in the opening 12, and a part of the cool air curtain is circulated in the display chamber 8 to cool the display chamber 8 to a predetermined temperature.

  Thereafter, the refrigerant flows out of the evaporator 19 (19A, 19B) and flows into the low-pressure channel 41A of the internal heat exchanger 41. Here, the refrigerant evaporated by the evaporator 19 (19A, 19B) and having a low temperature may be in a state where a liquid is mixed instead of a gas state, but the low-pressure side flow path of the internal heat exchanger 41 may be present. The refrigerant is heated by passing through 41A and exchanging heat with the refrigerant flowing through the high-pressure channel 41B. At this time, the degree of superheat of the refrigerant is ensured and the gas is completely in a gas state. The refrigerant heated by the internal heat exchanger 41 returns from the refrigerant introduction pipe 44 into the first rotary compression element of the compressor 24.

  The control device C operates the compressor motors 24MA and 24MB of the compressors 24 of the cooling devices R1 and R2 at the maximum operating frequency by the inverter devices 36 and 36 at the time of pull-down. Based on the detection of the temperature sensors 35A and 35B that detect the temperature of each region in the display chamber 8, the control device C detects that the temperature detected by all the temperature sensors 35A and 35B is a predetermined temperature. On condition that the set temperature has been reached, PID control is started on the operating frequencies of the compressor motors 24MA and 24MB by the inverter devices 36 and 36, and the inside of the display chamber 8 is maintained at the cooling set temperature.

  This PID control is executed by a PID arithmetic processing unit (not shown) provided inside the control device C, and the PID control arithmetic processing unit includes temperature sensors 35A, 35B corresponding to the respective cooling devices R1, R2. From the deviation e between the temperature (temperature in the display chamber 8) Tp detected by T and the target cooling set temperature Ts set by the control panel 30, the proportional (P), integral (I), and differential (I) The operation of D) is executed. Specifically, the PID calculation processing unit calculates a control amount in a direction in which the temperature Tp detected by the temperature sensor 35A or 35B is reduced in proportion to a deviation e between the target cooling set temperature Ts and Integral operation for calculating the control amount in the direction to reduce the integral value of deviation e (the value obtained by integrating deviation e with cooling set temperature Ts in the time axis direction), and the direction to reduce the slope (differential value) of change in deviation e The differential operation for calculating the control amount is performed, and the operating frequency of the compressor motor 24MA or 24MB of the compressor 24 of the corresponding cooling device R1, R2 is determined from the control amount obtained by adding these control amounts. The calculation formula is shown below.

Arithmetic Formula Kp × deviation e + Ki × integrated value of deviation e + Kd × differential value of deviation e = control amount Based on the calculated control amount, each inverter device 36 controls the operating frequency of each compressor motor 24MA, 24MB. As a result, the temperature in the display chamber 8 can be brought close to the target temperature with high accuracy, and overshooting, undershooting, and the occurrence of the hunting phenomenon associated therewith can be suppressed. It becomes possible to realize temperature control with high accuracy.

  Thus, in this embodiment, each cooling device R1 is provided on the condition that the temperatures detected by all the temperature sensors 35A and 35B provided in the regions corresponding to the respective cooling devices R1 and R2 have reached the cooling set value. Since the rotation speed control of the compressor 24 of R2 is started, it becomes possible to assist the cooling in the poorly cooled region by using the ability of the cooling device in the previously cooled region.

  Therefore, the entire display chamber 8 can be efficiently cooled, and the entire display chamber 8 can be cooled to the set temperature at an early stage.

  When the cooling operation as described above is performed, frost grows on the evaporators 19A and 19B of the respective cooling devices R1 and R2. Therefore, the control device C performs the defrosting operation of each of the evaporators 19A and 19B when the cooling operation has elapsed for a predetermined time. At this time, the control device C prohibits the evaporator 19 of each cooling device from performing the defrosting operation in an overlapping manner.

  Therefore, the control device C first performs a defrosting operation of any one cooling device, for example, the evaporator 19A of the cooling device R1. At this time, when the set temperature in the display chamber 8 or the temperature detected by the temperature sensor 35A is higher than a predetermined temperature (for example, a refrigeration temperature such as + 8 ° C.), the control device C is in the cooling device R1. The cooling operation is stopped, and off-cycle defrosting is performed in which only the cool air circulation fan 18A is operated (for example, the rotation speed is 1000 rpm).

  Thereby, since no refrigerant is supplied to the evaporator 19A of the cooling device R1, the frost on the evaporator 19A is gradually melted and removed by the circulating air in the display chamber 8. After the predetermined defrosting operation time has elapsed, the control device C ends the defrosting operation of the evaporator 19A of the cooling device R1 and returns to the cooling operation.

  When the defrosting operation of the evaporator 19A of the cooling device R1 is being performed, the control device C continues the cooling operation of the other cooling device R2. At this time, the control device C uses the drive circuit 37 to set the rotation speed of the cooling air circulation fan 18B of the cooling device R2 to a normal rotation speed in normal cooling operation (for example, a rotation at which the discharge air speed is 1.00 m / s). Number), the auxiliary rotational speed is increased by a predetermined rotational speed (for example, the rotational speed at which the discharge wind speed is 1.60 m / s). Further, the control device C operates as an auxiliary rotational speed obtained by increasing the rotational speed of the compressor motor 24MB of the compressor 24 of the cooling device R2 by a predetermined rotational speed by the inverter 36 from the rotational speed in the normal cooling operation. . In this embodiment, the rotational speeds of both the blower 18B and the compressor 24 are increased. However, the present invention is not limited to this, and either one may be used.

  As a result, the defrosting of the evaporator 19A of the cooling device R1 causes the cooling of the area in the display chamber 8 that has been cooled by the evaporator 19A, but the cooling of the other cooling devices R2 A part of the cold air exchanged with the evaporator 19B by operation branches from the gap between the closing plate 28 and the partition plate 26 at the interval between the upper end of the closing plates 28 and 28 and the partition plate 26, and only the evaporator 19B. Instead, it can be lowered to the front side of the evaporator 19A and the cool air can be discharged directly into the display chamber 8 from the front rear outlet 29.

  Therefore, by continuing the cooling operation by the other cooling device R2 and increasing the rotational speed of the blower 18B and the rotational speed of the compressor motor 24MB of the compressor, it is possible to compensate for the cooling capacity that is reduced as a whole of the display chamber 8. . Thereby, the temperature rise in the entire display room 8 due to the influence of defrosting can be minimized as much as possible, and the reduction of the power consumption of the entire showcase 1 can be realized.

  The set temperature in the display chamber 8 or the temperature detected by the temperature sensor 35A during the defrosting operation of the evaporator 19A of the cooling device R1 is equal to or lower than a predetermined temperature (for example, a low temperature cooling temperature such as + 2 ° C.). In some cases, in addition to stopping the cooling operation of the cooling device R1, off-cycle defrosting in which the operation of the cool air circulation blower 18A is stopped is executed.

  Thereby, by changing the defrosting mode according to the temperature in the display chamber 8, a more efficient defrosting operation can be realized and the temperature rise in the display chamber 8 can be suppressed as much as possible. It becomes.

  Then, as described above, when the defrosting operation of the evaporator 19A of the cooling device R1 is completed, the control device C performs the cooling operation of the cooling device R1 that has finished the defrosting operation, and has not yet performed the defrosting operation. The defrosting operation of the evaporator 19B of any one of the apparatuses, in this case, the cooling apparatus R2, is executed.

  In this case, the defrosting operation of the cooling device R2 is performed in the same manner as the defrosting operation of the cooling device R1 as described above, and the cooling operation of the other cooling device R1 in this case is performed by the cooling device R2 as described above. Similarly to the cooling operation, the cooling air circulation fan 18A and the compressor motor 24MA of the compressor are operated at an increased rotational speed.

  Thereby, when the control device C defrosts the evaporator 19 of any one of the cooling devices R, the cooling operation by the other cooling devices R is continued, and the blower 18 and the compressor motor of the other cooling device R are continued. By increasing the rotational speed of 24M, the defrosting of any of the evaporators 19 is performed, so that the cooling performance that decreases in the entire showcase 1 is continued by the cooling operation by the other cooling device R, and the blower 18 It can be compensated by increasing the number of revolutions. Therefore, the temperature rise in the display room 8 due to the effect of defrosting can be minimized as much as possible, and the reduction of the power consumption of the entire showcase 1 can be realized.

  When the defrosting operation of each cooling device R1, R2 is executed as described above, the drain water from each of the evaporators 19A, 19B is received by the drain pan D. At this time, as described above, a drain partition plate 32 is provided on the upper surface of the drain pan D to partition the region on the drain pan D into a region corresponding to the evaporator 19A side and a region corresponding to the evaporator 19B. Therefore, the drain water received in the drain pan D is drained from the drain holes 34A and 34B provided in the areas corresponding to the respective evaporators 19A and 19B, and the drain evaporators 3 of the corresponding cooling devices R and R2. Drain water is discharged.

  The drain water that flows down from the discharge pipes 33A and 33B and flows into the uppermost evaporating dish 52 of the drain evaporating apparatus 3 passes through the evaporating pipe 43 that is exchanged heat on the lower surface of the evaporating dish 52. Evaporation is efficiently performed by exchanging heat with the flowing high-temperature refrigerant.

  Further, the drain water that could not be processed in the uppermost evaporating dish 52 flows down to the evaporating dish 52 provided below via the overflow pipe 54, and each evaporating dish 52 also exchanges heat with the lower surface. Evaporation is efficiently performed by exchanging heat with the high-temperature refrigerant flowing into the disposed evaporation pipe 43.

  Furthermore, since each evaporating dish 52 is provided with an evaporating plate 53, when drain water permeates into the evaporating plate 53, it can diffuse from its surface and promote evaporation of the drain water.

  Thereby, it becomes possible to process the drain water discharged | emitted from corresponding evaporator 19A, 19B for every cooling device R1, R2. Accordingly, it is possible to eliminate the disadvantage that the drain water is supplied to the drain evaporator 3 of the one cooling device R in an uneven manner and a difference occurs in the evaporation capability of the drain evaporator.

  In particular, the refrigerant used in each of the cooling devices R1 and R2 in this embodiment has non-flammability and non-corrosion properties, does not destroy ozone, and has a global warming coefficient that is one-thousand that of chlorofluorocarbon refrigerants. The following carbon dioxide is used, and the high pressure side of the refrigerant circuit is at a supercritical pressure. Therefore, the cooling devices R1 and R2 constituting the refrigerant circuit 16 are integrally configured as a cooling unit, respectively, in order to perform a refrigerant leak inspection.

  Accordingly, in the showcase 1 where the cooling devices R1 and R2 that are integrally configured as a cooling unit are installed, the drain water discharged from the respective evaporators 19A and 19B is incorporated into the corresponding cooling devices R1 and R2. It is possible to perform processing in the drain evaporators 3 and 3, and it is possible to realize an appropriate evaporation treatment.

It is a vertical side view of a showcase to which the present invention is applied. It is a see-through | perspective front view of the showcase which shows the schematic arrangement | positioning state of an evaporator and a cooling device. It is a refrigerant circuit figure of a cooling device. It is a fragmentary perspective view in a showcase. FIG. 5 is a side view of FIG. 4. FIG. 5 is a front view of FIG. 4. FIG. 5 is a plan view of FIG. 4. It is a lower enlarged vertical side view of a showcase. It is a top view of a cooling device. It is a front view of a cooling device. It is an electrical block diagram of a control apparatus.

Explanation of symbols

R (R1, R2) Cooling device D Drain pan 1 Showcase 2 Machine room 3 Drain evaporator 4 Back plate 5 Duct 6 Thermal insulation wall 6A Bottom wall 8 Display chamber 12 Front opening 14 Cold air outlet 15 Cold air inlet 16 Refrigerant circuit 18A, 18B Cold air circulation blower 19 (19A, 19B) Evaporator 20 Pressure reducing device (electronic expansion valve or capillary tube)
22, 22A Radiator 24 Compressor 24MA, 24MB Compressor Motor 25 Radiator Blower 26 Partition Plate 26A Ventilation Hole 27 Partition Plate 28 Blocking Plate 29 Back Outlet 30 Control Panel 32 Drain Partition Plate 33A, 33B Drainage Pipes 34A, 34B Drainage Hole 35A, 35B Internal temperature sensor 36 Inverter device 37, 38 Drive circuit 43 Evaporating pipe 52 Evaporating dish

Claims (4)

A display room configured in an insulated wall;
A plurality of cooling devices each composed of a refrigerant circuit composed of a compressor, a radiator, a decompression device, an evaporator, and the like, and a blower for supplying cold air heat-exchanged with the evaporator into the display chamber;
A control device for controlling the operation of each cooling device,
When the control device defrosts the evaporator of any one of the cooling devices, the cooling operation by the other cooling device is continued, and the rotation speed of the blower and / or the compressor speed of the other cooling device is continued. A showcase characterized by raising the height.   When the temperature in the display chamber is higher than a predetermined value, the control device stops the cooling operation of the cooling device that performs defrosting of the evaporator, performs off-cycle defrosting that operates only the blower, and The showcase according to claim 1, wherein when the temperature in the display room is equal to or lower than the predetermined value, the blower of the cooling device that defrosts the evaporator is stopped. A duct configured between a rear plate of the display chamber whose front surface is open and the heat insulating wall, and in which an evaporator and a blower of each cooling device are installed;
A cold air outlet and a cold air inlet formed above and below the front opening of the display chamber;
A partition plate provided in the duct on the cold air outlet side of each evaporator, and provided with a plurality of vent holes;
A partition plate provided between each of the evaporators with an interval from the partition plate;
A closing plate that covers the front surface of each evaporator and is provided with a gap between the back plate and the partition plate;
The showcase according to claim 1, further comprising a rear outlet formed in the partition plate. The control device includes temperature sensors that respectively detect the temperatures of the regions in the display chamber cooled by the evaporator of each cooling device,
The showcase according to any one of claims 1 to 3, wherein the rotation speed control of the compressor is started on condition that the temperatures detected by all the temperature sensors have reached a set value.

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