JP4654073B2 - Refrigeration air conditioning system - Google Patents

Description

  The present invention relates to a refrigerating and air-conditioning system capable of reducing energy consumption due to operation of an air conditioner and a showcase by using cold air leaking from an opening of a refrigerated or frozen showcase having an opening on the front surface. Is.

  2. Description of the Related Art Conventionally, as an air conditioning system for performing indoor air conditioning, indoor air is exhausted to the outside, ventilation means for supplying the outside air to the room, indoor air exhausted to the outside by the ventilation means, and outdoor to be supplied to the room A sensible heat exchanger that exchanges sensible heat with other air and an air conditioner that cools or heats indoor air and outside air and supplies the air to the room are known.

Moreover, as a conventional showcase, a showcase body having an opening on the front surface and a cooler provided on the showcase body are formed, and air cooled by the cooler is circulated in the opening to form an air curtain. By doing so, the thing which cooled the inside of a showcase main body is known. However, in the showcase, since air with high enthalpy in the room enters from the opening of the showcase body, there is a possibility that the cooling efficiency is lowered and the power consumption is increased. Also, cold air leaks from the opening of the showcase body, and cold aisles occur when the leaked cold air stagnates in a passage located on the front side of the showcase body, which may result in an uncomfortable environment for the user. . Therefore, cold air stagnating from the lower part of the showcase body is inhaled, and cold air circulation means for circulating the inhaled cold air to the front side of the air curtain is provided to prevent the air curtain from contacting the air curtain with high enthalpy. What improved the cooling efficiency in a case main body and eliminated the cold aisle is known (for example, refer patent document 1).
Japanese Patent Laid-Open No. 6-241641

  However, the cold air leaked from the opening of the showcase body has a lower enthalpy than the indoor air, but the absolute humidity does not change, and condensation occurs at the air discharge port of the cold air circulation means to prevent condensation. In addition, a dew-proof heater must be used in the vicinity of the air discharge port, and there is a problem that it is not possible to reduce power consumption.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to prevent the occurrence of dew condensation in a showcase without using a dew-proof heater and to save energy. It is to provide a refrigeration air conditioning system.

In order to achieve the above object, the present invention provides a showcase in which an opening is provided on the front surface and an air curtain is formed in the opening by circulating air cooled by a cooler, and leaks from the opening of the showcase. A cool air suction means for sucking cool air stagnating on the front side of the showcase, a dehumidification means for dehumidifying the cool air sucked by the cool air suction means, and a front side of the air curtain formed in the showcase for the dehumidified cold air The sensible heat exchange means for sensible heat exchange, the sensible heat exchange means for showcase for sensible heat exchange between the cool air whose temperature has been increased by dehumidification by the dehumidification means and the cold air sucked by the cold air suction means, and sensible heat for the showcase and a cold air circulation means for circulating the cold air temperature rose to room showcase is installed by being sensible heat exchanged by the exchanging means The dehumidifying unit, adsorbs moisture in the air by the hygroscopic dehumidifying member, by heating the dehumidifying member by heat, and configured to play the dehumidifying member if moisture is the release of dehumidifying member.

As a result, the cold air leaking from the opening of the showcase and stagnating on the front side of the showcase is dehumidified, so that the front side of the air curtain of the showcase can be covered with the cold air having a low absolute humidity. Moreover, since the moisture of the dehumidifying member is released by heating the dehumidifying member by exhaust heat, it is not necessary to separately heat the dehumidifying member with a heater in order to regenerate the dehumidifying member. Further, since the cool air whose temperature has been increased by dehumidifying means and the cool air sucked by the cold air sucking means are sensible heat exchanged by the sensible heat exchanging means for the showcase, the temperature of the cold air dehumidified by the dehumidifying means is adjusted. The enthalpy of cold air can be reduced by lowering. In this case, cold air whose temperature has risen due to sensible heat exchange by the sensible heat exchange means for the showcase circulates in the room where the showcase is installed, and therefore air having a lower enthalpy than the indoor air is circulated in the room. Can be made.

According to the present invention, since the front side of the air curtain of the showcase can be covered with cool air having a low absolute humidity, condensation near the cool air discharge port from which cool air is discharged can be prevented. Moreover, inflow of the air with high absolute humidity to the ventilation path which forms an air curtain in the opening part of a showcase can be prevented, and the amount of frost formation of a cooler can be reduced. Furthermore, the cold air discharged by the cold air discharge means does not increase the enthalpy even if it is dehumidified by the dehumidifying member, so that the cooling load of the showcase does not increase. Further, it is not necessary to separately heat the dehumidifying member with a heater, so that energy saving can be achieved. Furthermore, since the enthalpy of the cold air can be lowered by lowering the temperature of the cold air dehumidified by the dehumidifying means, it is possible to further reduce the cooling load of the showcase. In this case, since air having a lower enthalpy than indoor air can be circulated in the room, the cooling load in the room can be reduced.

  1 to 10 show a first embodiment of the present invention. FIG. 1 is a schematic configuration diagram of a refrigerating and air conditioning system showing a wind circuit. FIG. 2 is a schematic configuration diagram of a refrigerating and air conditioning system showing a refrigerant circuit. 3 is a side sectional view of the showcase, FIG. 4 is a block diagram showing a control system, FIG. 5 is a schematic configuration diagram of a refrigeration air-conditioning system showing an air flow path during cold air circulation operation, and FIG. 6 is air during outdoor air circulation operation. FIG. 7 is an air line diagram showing the air state during the cold air circulation operation, FIG. 8 is an air line diagram showing the air state during the outdoor air circulation operation, and FIG. FIG. 10 is a flowchart relating to control of the ventilation amount of the showcase blower.

  This refrigeration air-conditioning system is applied to a store A of a retail store that sells foods and beverages, and has a ventilation unit 10 for ventilating the store A, and cooling and heating the store A. Air conditioner 20, a plurality of showcases 30 installed in store A, a refrigerant circuit 40 for configuring the refrigeration cycle of each showcase 30, and control for performing switching control of the operation of ventilation unit 10 Part 50.

  As shown in FIG. 1, the ventilation unit 10 includes a first ventilation path 11 for discharging the return air (RA) in the store A to the outside and a lower part of the passage located in front of the outside air (OA) or the showcase 30. A second ventilation path 12 for circulating the cool air to the air suction side of the air conditioner 20, and a third ventilation path 13 for circulating the cool air in front of the showcase 30 to the air suction side of the air conditioner 20; And a fourth ventilation path 14 for circulating cool air in the lower part of the passage located in front of the showcase 30 to the upper part on the front side of the showcase 30, and the ventilation paths 11, 12, 13, and 14 each have a first ventilation path 14. -4th air blower 11a, 12a, 13a, 14a is provided. The first ventilation path 11 has an inflow side connected to an air suction port 11b provided on a ceiling in the store A, and an outflow side connected to an exhaust louver or a vent cap (not shown) provided on the outer wall of the store A. The second ventilation path 12 is connected in parallel to the fifth ventilation path 15 for circulating the outside air (OA) on the inflow side and the sixth ventilation path 16 for circulating the cool air in front of the showcase 30, and the outflow side thereof. It is connected to the air intake side of the air conditioner 20. The third ventilation path 13 has an inflow side connected to the sixth ventilation path 16 and an outflow side connected to the air suction side of the air conditioner 20. The fourth ventilation path 14 has an inflow side connected to the sixth ventilation path 16 and an outflow side connected to a seventh ventilation path 17 that circulates air for covering the outside of the air curtain formed in the opening of the showcase 30. ing. Further, the fifth ventilation path 15 is connected to an intake gallery (not shown) provided on the outer wall of the store A on the inflow side, and the outflow side is provided on the suction side of the second ventilation path 12 and the outflow side of the fourth ventilation path 14. Further, they are branched and connected to the upstream side of the fourth blower 14a. The 5th ventilation path 15 is provided with the 1st damper 15a, The flow path of the 5th ventilation path 15 can be switched to the 2nd ventilation path 12 side and the 4th ventilation path 14 side by the 1st damper 15a. Moreover, the 6th ventilation path 16 is provided with the 2nd damper 16a, and the flow path of the 6th ventilation path 16 is made into the 2nd ventilation path 12 side and the 3rd and 4th ventilation paths 13 and 14 side by the 2nd damper 16a. Switching is possible. Furthermore, a third damper 13 b that can close an end portion is provided on the discharge side of the third ventilation path 13. The first damper 15a, the second damper 16a, and the third damper 13b are each driven by a motor (not shown). Here, the 5th ventilation path 15 is set to the 2nd ventilation path 12 side by the 1st damper 15a, and the 6th ventilation path 16 is set to the 3rd and 4th ventilation paths 13 and 14 side by the 2nd damper 16a. By opening the 3rd ventilation path 13 with the 3rd damper 13b, the wind circuit for cold air circulation operation is comprised in the ventilation unit 10. FIG. The fifth damper 15a sets the fifth ventilation path 15 to the fourth ventilation path 14 side, the second damper 16a sets the sixth ventilation path 16 to the second ventilation path 12 side, and the third damper 13b sets the second ventilation path 12 side. By closing the three ventilation paths 13, the ventilation unit 10 is configured with a wind circuit for an outside air circulation operation.

  The first ventilation path 11 and the second ventilation path 12 are provided with a first sensible heat exchanger 10a to exchange heat between the air flowing through the first ventilation path 11 and the sensible heat of the air flowing through the second ventilation path 12. It is like that. The third ventilation path 13 and the fourth ventilation path 14 are provided with a second sensible heat exchanger 10b to exchange heat between the air flowing through the third ventilation path 13 and the sensible heat of the air flowing through the fourth ventilation path 14. It is like that. The first sensible heat exchanger 10a and the second sensible heat exchanger 10b are fixed cross-flow sensible heat exchangers formed of a member such as aluminum, and only sensible heat is obtained without performing heat exchange of latent heat. Heat exchange is performed.

  A desiccant rotor 10c as a dehumidifying means is provided on the downstream side of the first sensible heat exchanger 10a in the first ventilation path 11 and the upstream side of the second sensible heat exchanger 10b in the fourth ventilation path 14, and the fourth ventilation path. The moisture in the air flowing through the air 14 is released into the air flowing through the first ventilation path 11. The desiccant rotor 10c is made of a member in which an element containing a hygroscopic agent such as silica gel or zeolite is formed in a disk shape, and the element rotates between the first ventilation path 11 and the fourth ventilation path 14 by a motor (not shown). While moving. A heating means for heating the air flowing through the first ventilation path 11 is provided between the desiccant rotor 10 c of the first ventilation path 11 and the first sensible heat exchanger 10 a. The air flowing through the first ventilation path 11 is heated by the heating means and then passes through the desiccant rotor 10c to release the moisture adsorbed on the element. The heating means is connected to a refrigerant circuit 40 constituting a refrigeration cycle of the showcase 30 to be described later, and a regeneration condenser 10d for releasing a part of exhaust heat generated during the cooling operation of the showcase 30 is used.

  The air conditioner 20 includes a blower 21 and a heat exchanger 22, and sucks in air (RA) in the store A from an air suction port 23 provided on the ceiling surface in the store A, and the sucked air (RA). It cools or heats and it discharges in store A as supply air (SA) from the air discharge port 24 provided in the ceiling surface in store A. Moreover, the heat exchanger 22 used here may exchange heat between natural refrigerants such as chlorofluorocarbon refrigerant or carbon dioxide distributed by a compressor (not shown) and air (RA) in the store A, or a pump (not shown). The chilled water or hot water generated by a turbo chiller and a boiler or a cold / hot water generator, etc., and the air (RA) in the store A may be heat-exchanged.

  As shown in FIG. 3, each showcase 30 has a showcase body 31 having an opening on the front surface, and a product cooling ventilation path 32 formed along the bottom surface side, the back surface side, and the top surface side in the showcase body 31. It has.

  The showcase body 31 is formed with heat insulating walls 31a on the upper surface side, the back surface side, the bottom surface side, and the left and right side surfaces. In the showcase body 31, a top plate 31b, a back plate 31c, and a bottom plate 31d are provided on the top surface side, the back surface side, and the bottom surface side, respectively, spaced from the inner surface of the heat insulating wall 31a, and a product storage portion 31e is provided therein. Is provided. In the product storage unit 31e, a plurality of product shelves 31f are provided in the vertical direction at intervals, and the products are displayed on each product shelf 31f. The showcase body 31 is provided with a cold air inflow passage 31g along the bottom surface side and the back surface side, and the air sucked from the cold air inlet 31h provided below the opening of the showcase main body 31 is supplied to the cold air inflow passage 31g. The air is sucked in and distributed to the sixth ventilation path 16. Further, the showcase body 31 is provided with a cold air outflow path 31 i along the upper surface, and the cold air outflow path 31 i is connected to the seventh ventilation path 17. A cold air outlet 31j is provided on the front end side of the cold air outlet 31i downward, and air discharged from the cold air outlet 31j covers the front side of the opening.

  The product cooling air passage 32 is formed between the inner surface of the heat insulating wall 31a and the top plate 31b, the back plate 31c, and the bottom plate 31d. The back side and the top surface of the product cooling air passage 32 are on the product storage portion 31e side by the partition plate 32a. And the heat insulating wall 31a side. Also, the product cooling ventilation path 32 on the bottom side is provided with a showcase blower 32b for circulating air, and cooling for cooling air is provided on the product storage section 31e side of the product cooling ventilation path 32 on the back side. A container 32c is provided. The air flow rate of the showcase blower 32b used here can be changed. Further, an air suction port 32d is provided at the end of the product cooling air passage 32 located on the lower end side of the opening of the showcase body 31, and is provided at the end of the product cooling air passage 32 located on the upper end side of the opening. Is provided with an air discharge port 32e.

  As shown in FIG. 2, the refrigerant circuit 40 includes a regeneration condenser 10d, each cooler 32c, a compressor 41, each electromagnetic valve 42, an expansion valve 43, and a condenser 44, which are pipes for refrigerant circulation. Connected by. That is, the discharge side of the compressor 41 is connected to the inflow side of the regeneration condenser 10d provided in the first ventilation path 11, and the inflow side of the condenser 44 is connected to the outflow side of the regeneration condenser 10d. ing. The inflow side of each cooler 32c is connected in parallel to the outflow side of the condenser 44. Each electromagnetic valve 42 and expansion valve 43 are connected between the outflow side of the condenser 44 and the inflow side of each cooler 32c. The suction side of the compressor 41 is connected in parallel to the outflow side of each cooler 32c.

  The control unit 50 is configured by a microcomputer, and in its memory, a program for calculating enthalpy from temperature and relative humidity data is stored in addition to a program related to operation control of the ventilation unit 10. Further, as shown in FIG. 4, the control unit 50 includes first to third dampers 15a, 16a, 13b, first to fourth blowers 11a, 12a, 13a, 14a, a showcase blower 32b, a cold air outflow passage. The first temperature / humidity detector 51 for detecting the temperature and humidity of the air flowing through 31i, the second temperature / humidity detector 52 for detecting the temperature and humidity of the outside air (OA), and the product storage of the showcase body 31 A first temperature detector 53 for detecting the temperature of the upper part of the part 31e, a second temperature detector 54 for detecting the temperature of the lower part of the product storage part 31e of the showcase body 31, and a first during cold air circulation operation. A storage unit 55 for storing enthalpy data calculated from the temperature T1 and the relative humidity H1 detected by the temperature and humidity detector 51 is connected. The first and second temperature / humidity detectors 51 and 52 are well-known temperature / humidity sensors in which the temperature detection unit is made of a platinum-side temperature resistor, thermistor, or the like, and the humidity detection unit is made of ceramic, polymer polymer, or the like. The first and second temperature detectors 53 and 54 are well-known temperature sensors including a platinum side temperature resistor and a thermistor.

  In the refrigerating and air conditioning system configured as described above, the showcase 30 is cooled by operating the compressor 41 of the refrigerant circuit 40. The refrigerant discharged from the compressor 41 flows through the regeneration condenser 10 d and the condenser 44, then flows through the cooler 32 c via the electromagnetic valves 42 and the expansion valves 43, and is sucked into the compressor 41.

  In each showcase 30, the air in the product storage portion 31e is sucked into the product cooling air passage 32 from the air suction port 32d by the showcase blower 32b. A part of the air flowing into the product cooling air passage 32 flows through the product storage portion 31e side and is cooled by the cooler 32c, and the other air flows through the heat insulating wall 31a side without being cooled by the cooler 32c. The air discharged from the air discharge port 32e forms air curtains having different temperatures between the inside and the outside of the product storage portion 31e, and cools the product storage portion 31e. At this time, an air curtain is formed in the opening portion of the showcase body 31, but the cool air in the product storage portion 31 e leaks or the air around the opening portion is cooled to the front of the showcase body 31. Cold air whose temperature is lower than the air in the store A stagnates in the lower part of the passage.

  The air conditioner 20 cools or heats the air in the store A sucked from the air suction port 23 by the blower 21 by the heat exchanger 22 and discharges it from the air discharge port 24 to cool or heat the store A.

  Further, when the temperature and humidity of the outside air is high in summer or the like, the air conditioner 20 performs a cooling operation, and the ventilation unit 10 performs a cold air circulation operation. That is, the flow path of the fifth ventilation path 15 is set to the second ventilation path 12 side by the first damper 15a, and the flow path of the sixth ventilation path 16 is set by the second damper 16a to the third and fourth ventilation paths 13, The first to fourth blowers 11a, 12a, 13a, 14a and the desiccant rotor 10c are operated. The third damper 13b opens the third ventilation path.

  The operation of the ventilation unit 10 at this time will be described with reference to the schematic configuration diagram showing the air flow path in the cold air circulation operation of FIG. 5 and the air diagram of FIG. In the 1st ventilation path 11, the return air (RA) in the store A of the state A which flows in from the air inlet 11b by the 1st air blower 11a passes through the 1st sensible heat exchanger 10a, and thereby the 2nd ventilation path. Heat is exchanged with the outside air (OA) flowing through 12 to state B. Further, the air in the state B passes through the regeneration condenser 10d, and is heated up to the state C by exchanging heat with the refrigerant flowing through the regeneration condenser 10d. Further, the air in the state C passes through the desiccant rotor 10c, thereby releasing the moisture adsorbed by the desiccant rotor 10c to be humidified to the state D and being cooled by the heat of evaporation of moisture. The air in this state D is discharged outdoors as exhaust (EA). Moreover, in the 2nd ventilation path 12, the external air (OA) of the state E which flows in through the 5th ventilation path 15 by the 2nd air blower 12a passes through the 1st sensible heat exchanger 10a, and thereby the 1st ventilation path. Heat is exchanged with the return air (RA) in the store A that circulates 11 and cooled to the state F. The air in this state F is distributed to the air intake side of the air conditioner 20 and supplied into the store A. Moreover, in the 3rd ventilation path 13, the cold air of the state G which flows in through the cold air inflow path 31g and the 6th ventilation path 16 from the cold air inlet 31h by the 3rd air blower 13a passes the 2nd sensible heat exchanger 10b. As a result, heat is exchanged with the cold air flowing through the fourth ventilation path 14 and the state H is heated. The air in this state H is distributed to the air intake side of the air conditioner 20 and supplied into the store A. Moreover, in the 4th ventilation path 14, the cold air of the state G which flows in through the cold air inflow path 31g and the 6th ventilation path 16 from the cold air inlet 31h by the 4th air blower 14a passes through the desiccant rotor 10c, While being dehumidified to I, it is heated by the heat of condensation of moisture. The air in the state I passes through the second sensible heat exchanger 10b, and is cooled to the state J through heat exchange with the cold air flowing through the third ventilation path 13. Air in this state J is discharged from the cold air discharge port 31j through the seventh ventilation path 17 and the cold air outflow path 31i.

  By operating the ventilation unit 10 as described above, the outside air (OA) is supplied to the air intake side of the air conditioner 20 by reducing enthalpy by sensible heat exchange with the return air (RA). The return air (RA) is heated by exhaust heat generated by the operation of the showcase 30, and is then used as regeneration air for the desiccant rotor 10c and then discharged to the outdoors as exhaust (EA). Further, a part of the cool air in the lower part of the passage located in front of the showcase 30 is dehumidified by the desiccant rotor 10c and then exchanged with other cool air to reduce the enthalpy so that the outside of the air curtain of the showcase 30 Circulate. Further, the other cold air is supplied to the air intake side of the air conditioner 20 by increasing the enthalpy by heat exchange with a part of the cold air. At this time, the other cold air supplied to the air intake side of the air conditioner 20 increases the enthalpy by heat exchange with some of the cool air, but the enthalpy is smaller than the air in the store A, so the air conditioning load is small. There is no increase.

  Further, when the temperature and humidity of the outside air is low in winter or the like and the enthalpy of the outside air (OA) is less than the enthalpy of the air in the state J in the cold air circulation operation, the air conditioner 20 performs the heating operation and the ventilation unit 10 distributes the outside air. Do the driving. That is, the flow path of the fifth ventilation path 15 is set on the fourth ventilation path 14 side by the first damper 15a, and the flow path of the sixth ventilation path 16 is set on the second ventilation path 12 side by the second damper 16a. The first blower 11a, the second blower 12a, and the fourth blower 14a are operated to stop the third blower 13a and the desiccant rotor 10c. The third damper 13 b closes the third ventilation path 13.

  The operation of the ventilation unit 10 at this time will be described with reference to the schematic configuration diagram showing the air flow path in the outside air circulation operation of FIG. 6 and the air diagram of FIG. In the first ventilation path 11, the return air (RA) in the store A in the state A ′ flowing from the air suction port 11b by the first blower 11a passes through the first sensible heat exchanger 10a, and thereby the second ventilation Heat is exchanged with the cold air flowing through the passage 12 to cool to the state B ′. In addition, the air in the state B ′ passes through the regeneration condenser 10d, and is heated to the state C ′ through heat exchange with the refrigerant flowing through the regeneration condenser 10d. The air in this state C ′ is discharged outdoors as exhaust (EA). Further, in the second ventilation path 12, the cold air in the state D ′ flowing from the cold air inlet 31h through the cold air inlet 31h and the sixth ventilation path 16 by the second blower 12a passes through the first sensible heat exchanger 10a. As a result, heat is exchanged with the return air (RA) in the store A that circulates through the first ventilation path 11, and the state is heated to the state E '. The air in this state E ′ is distributed to the air intake side of the air conditioner 20 and supplied into the store A. Further, in the fourth ventilation path 14, the outside air (OA) in the state F ′ that flows in through the fifth ventilation path 15 by the fourth blower 14a is cooled and discharged through the seventh ventilation path 17 and the low-humidity ventilation path 31i. It distribute | circulates the outer side of an air curtain toward the downward direction from the exit 31j.

  By operating the ventilation unit 10 as described above, the outside air (OA) circulates outside the air curtain of the showcase 30 without being subjected to heat exchange and dehumidification. The return air (RA) is exhausted outdoors as exhaust (EA) after heat exchange with the cold air in front of the showcase 30 by the first sensible heat exchanger 10a. Further, the cool air in front of the showcase 30 is supplied to the air intake side of the air conditioner 20 by increasing the enthalpy by exchanging heat with the return air (OA) by the first sensible heat exchanger 10a.

  Next, the operation of the control unit 50 relating to the operation switching control between the cold air circulation operation and the outside air circulation operation will be described with reference to the flowchart of FIG. First, the ventilation unit 10 is circulated in cold air (step S1), and the enthalpy E1 is calculated from the detected temperature T1 and the detected humidity H2 of the first temperature / humidity detector 51 at that time (step S2). Remember. Next, the enthalpy E2 of the outside air (OA) is calculated from the detected temperature T2 and the detected humidity H2 of the second temperature / humidity detector 52 (step S3). When the stored enthalpy E1 is equal to or lower than the enthalpy E2 of the outside air (step S4), a cold air circulation operation is performed (step S1). When the stored enthalpy E1 is larger than the enthalpy E2 of the outside air (OA) (step S4), the outside air circulation operation is performed (step S5).

  The operation of the control unit 50 relating to the control of the air flow rate of the showcase blower 32b will be described with reference to the flowchart of FIG. First, a temperature difference ΔT between the detected temperature T3 of the first temperature detector 53 and the detected temperature T4 of the second temperature detector 54 is calculated (step S11). When the temperature difference ΔT is smaller than the predetermined set temperature difference ΔT1 (step S12), the air flow rate of the showcase blower 32b is decreased (step S13). When the temperature difference ΔT is equal to or larger than the predetermined set temperature difference ΔT1 (step S12) and the temperature difference ΔT is larger than the predetermined set temperature difference ΔT2 (ΔT1 <ΔT2) (step S14), the showcase blower 32b. Is increased (step S15).

  Thus, according to the refrigerating and air-conditioning system of the present embodiment, the cold air leaking from the opening of the showcase 30 and stagnating on the front side of the showcase 30 is sucked from the cold air inlet 31h, and the sucked cold air is removed from the desiccant rotor. Since the air is discharged so as to cover the front side of the air curtain from the cold air discharge port 31j after dehumidification by 10c, the front side of the air curtain of the showcase 30 can be covered with the cool air having a low absolute humidity. Condensation near 31j can be prevented. Moreover, inflow of air with high absolute humidity from the air inlet 32d of the showcase 30 to the product cooling air passage 32 can be prevented, and the amount of frost formation on the cooler 32c can be reduced. Furthermore, since the enthalpy does not change even if the cold air discharged from the cold air discharge port 31j is dehumidified by the desiccant rotor 10c, the cooling load of the showcase 30 does not increase.

  In addition, since the second sensible heat exchanger 10b that exchanges sensible heat of the cold air whose temperature has been increased by dehumidification by the desiccant rotor 10c is exchanged with the cold air drawn from the cold air inlet 31h, the cold air dehumidified by the desiccant rotor 10c By reducing the temperature, the enthalpy of the cold air can be reduced, and the cooling load of the showcase 30 can be further reduced.

  In addition, since the cool air whose temperature has been increased by the sensible heat exchange by the second sensible heat exchanger 10b is circulated in the store A via the air conditioner 20, the enthalpy is more enthalpy than the air in the store A. Low air can be circulated in the store A via the air conditioner 20, and the cooling load in the store A can be reduced.

  Further, when ventilating the store A, the first sensible heat is exchanged between the air in the store A exhausted to the outside by the first sensible heat exchanger 10a and the outside air supplied into the store A. Since the air in the store A heated by the exchanger 10a is heated as regeneration air for releasing the moisture adsorbed by the desiccant rotor 10c, the amount of heat necessary for heating the regeneration air to a predetermined temperature Can be reduced, and energy saving can be achieved. Further, air having a lower enthalpy than the outside air can be circulated in the store A, and the cooling load can be reduced.

  Further, since the regeneration air for releasing the moisture adsorbed by the desiccant rotor 10c is exhausted by the exhaust heat released from the regeneration condenser 10d connected to the refrigerant circuit 40, a separate heater is required. Therefore, the air for regeneration can be heated by the exhaust heat that has been exhausted outdoors, and energy saving can be further achieved.

  Further, since the outside air is discharged from the cold air discharge port 31j so as to cover the front side of the air curtain, for example, when the temperature and humidity of the outside air are low, such as in winter, the outside air having a low enthalpy is discharged from the cold air discharge port 31j. The cooling load of the showcase 30 can be further reduced.

  In addition, since the cold air sucked from the cold air inlet 31h is sensible heat exchanged with the air in the store A by the first sensible heat exchanger 10a, the cold air is circulated in the store A through the air conditioner 20. Cold air having a higher enthalpy than the outside air can be further circulated in the store A with a higher enthalpy, and the heating load can be reduced. In addition, since the air in the store A is sensible heat exchanged with the cold air by the first sensible heat exchanger 10a, the air is discharged to the outside, so the outside air discharged from the cold air discharge port 31j and the store A discharged to the outdoors. Ventilation can be performed with the air inside.

  Further, the enthalpy E1 of the cold air discharged from the cold air discharge port 31j during the cold air circulation operation stored in the storage unit 50 is compared with the enthalpy E2 of the outdoor air, and the enthalpy E1 of the cold air is more than the enthalpy E2 of the outdoor air. When it is small, the cold air circulation operation is performed, and when the cold enthalpy E1 is larger than the outdoor enthalpy E2, the outdoor air circulation operation is performed. Therefore, the operation of the ventilation unit 10 can be switched according to the temperature and humidity conditions of the outdoor air. The operation which always reduces the cooling load of the showcase 30 can be performed.

  Further, when the detected temperature difference ΔT between the temperature T3 in the upper part of the product storage unit 31e and the temperature in the lower part T4 of the product storage unit 31e is smaller than the predetermined first set temperature difference ΔT1, the air flow rate of the showcase blower 32b is reduced. When the detected temperature difference ΔT is larger than the predetermined second set temperature difference ΔT2, the air flow rate of the showcase blower 32b is increased, so that the temperature difference ΔT in the product storage portion 31e is set to a predetermined temperature. It can hold | maintain in the range of a difference, and can prevent the increase in the energy consumption by the inside of the goods storage part 31e being cooled more than necessary.

  FIGS. 11 to 13 show a second embodiment of the present invention, FIG. 11 is a schematic configuration diagram of a refrigeration air conditioning system showing a refrigerant circuit and a drain water circuit, and FIG. 12 is a first sensible heat exchange showing a bypass circuit. FIG. 13 is an air diagram showing the state of air during cold air circulation operation, and FIG. 14 is an air diagram showing the state of air when external air is circulated through the bypass circuit. In addition, the same code | symbol is attached | subjected and shown to the component similar to the said embodiment.

  As shown in FIG. 11, the refrigerating and air-conditioning system of the present embodiment includes a humidifier 60 for humidifying the air flowing upstream of the first sensible heat exchanger 10a in the first ventilation path 11, and each showcase is provided. The drain water generated by the dew condensation or defrosting operation generated in the cooler 32 c provided in the main body 31 is pumped by the pump 61, and the drain water pumped by the pump 61 is fed from the spray nozzle 62 into the first ventilation path 11. It comes to spray. Moreover, as shown in FIG. 12, the bypass ventilation path 18 is provided in the 2nd ventilation path 12 side of the 1st sensible heat exchanger 10a, and the bypass ventilation path 18 can be opened and closed by the 4th damper 18a. .

  In the refrigeration and air conditioning system configured as described above, the operation of the ventilation unit 10 during the cold air circulation operation will be described with reference to the air diagram of FIG. In the 1st ventilation path 11, the return air (RA) in the store A of the state a which flows in from the air inlet port 11b by the 1st air blower 11a is to the state b by the drain water sprayed from the spray nozzle 62 of the humidifier 60. While being humidified, it is cooled by the heat of evaporation of moisture. The air in the state b passes through the first sensible heat exchanger 10a, and is heated to the state c through heat exchange with the outside air (OA) flowing through the second ventilation path 12. Furthermore, the air in the state c passes through the regeneration condenser 10d, and is heated to the state d through heat exchange with the refrigerant flowing through the regeneration condenser 10d. In addition, the air in the state d passes through the desiccant rotor 10c, thereby releasing moisture adsorbed by the desiccant rotor 10c to humidify to the state e and cooling by the evaporation heat of moisture. The air in this state e is discharged outdoors as exhaust (EA). Moreover, in the 2nd ventilation path 12, the external air (OA) of the state f which flows in through the 5th ventilation path 15 by the 2nd air blower 12a passes through the 1st sensible heat exchanger 10a, and is by the humidifier 60. Heat is exchanged with the return air (RA) in the store A that circulates through the humidified first ventilation path 11, and is cooled to the state g. The air in this state g is distributed to the air intake side of the air conditioner 20 and supplied into the store A. Moreover, in the 3rd ventilation path 13, the cold air of the state h which flows in through the cold air inflow path 31g and the 6th ventilation path 16 from the cold air inlet 31h by the 3rd air blower 13a passes the 2nd sensible heat exchanger 10b. As a result, heat is exchanged with the cold air flowing through the fourth ventilation path 14, and the state i is heated. The air in this state i is distributed to the air intake side of the air conditioner 20 and supplied into the store A. Moreover, in the 4th ventilation path 14, the cold air of the state h which flows in through the cold air inflow path 31g and the 6th ventilation path 16 from the cold air inlet 31h by the 4th air blower 14a passes through the desiccant rotor 10c, and is in a state. It is dehumidified to j and heated by the heat of condensation of moisture. By passing through the second sensible heat exchanger 10b, the air in the state j is cooled to the state k through heat exchange with the cold air flowing through the third ventilation path 13. The air in this state k is discharged from the cold air discharge port 31j through the seventh ventilation path 17 and the cold air outflow path 31i.

  By operating the ventilation unit 10 as described above, the outside air (OA) is air-conditioned by reducing enthalpy by sensible heat exchange with the return air (RA) cooled by the evaporating heat by being humidified by the humidifier 60. Supplied to the air intake side of the machine 20. The return air (RA) is heated by exhaust heat generated by the operation of the showcase 30, and is then used as regeneration air for the desiccant rotor 10c and then discharged to the outdoors as exhaust (EA). Further, a part of the cool air in the lower part of the passage located in front of the showcase 30 is dehumidified by the desiccant rotor 10c and then exchanged with other cool air to reduce the enthalpy so that the outside of the air curtain of the showcase 30 Circulate. Further, the other cold air is supplied to the air intake side of the air conditioner 20 by increasing the enthalpy by heat exchange with a part of the cold air. At this time, the other cold air supplied to the air intake side of the air conditioner 20 increases the enthalpy by heat exchange with some of the cool air, but the enthalpy is smaller than the air in the store A, so the air conditioning load is small. There is no increase.

  Further, when the temperature and humidity of the outside air temperature in winter and the like are low and the enthalpy of the outside air (OA) is smaller than the enthalpy of the air in the cold air circulation operation state k, the ventilation unit 10 distributes the outside air as in the first embodiment. Do the driving.

  Further, when the air conditioner 20 performs the cooling operation and the ventilation unit 10 performs the cool air circulation operation, the enthalpy of the outside air (OA) becomes smaller than the enthalpy of the return air (RA) in the store A. In that case, the bypass ventilation path 18 is opened by the fourth damper 18a. As a result, as shown in the air diagram of FIG. 14, the outside air (OA) in the state 1 that circulates through the second ventilation path 12 is a bypass ventilation path that has a small pressure loss without flowing through the first sensible heat exchanger 10a. 18 is distributed in the store A without being heated by the return air (RA).

  Thus, according to the refrigerating and air-conditioning system of the present embodiment, the humidifier 60 for humidifying the air flowing through the upstream side of the first sensible heat exchanger 10a of the first ventilation path 11 is provided. The return air flowing through the first ventilation path 11 humidified by the vessel 60 can be cooled by the heat of evaporation of moisture, and the cooled return air is subjected to sensible heat exchange with the outside air by the first sensible heat exchanger 10a. Thus, the enthalpy of the outside air can be further reduced and distributed in the store A through the air conditioner 20. Thereby, reduction of the air-conditioning load in store A can further be aimed at.

  Further, since the bypass air passage 18 that can be opened and closed by the fourth damper 18a is provided in the first sensible heat exchanger 10a, the first sensible heat is generated when the enthalpy of the outside air is smaller than the enthalpy of the return air in the store A. The outside air can be circulated in the store A without performing heat exchange by the exchanger 10a, and an increase in the enthalpy of the outside air by the first sensible heat exchanger 10a can be prevented.

  In the first and second embodiments, the heating means for heating the air that releases the moisture adsorbed on the desiccant rotor 10c is connected to the refrigerant circuit 40 constituting the refrigeration cycle of the showcase 30, Although the thing using the condenser 10d for reproduction | regeneration for releasing the waste heat which generate | occur | produces at the time of the cooling operation of case 30 was shown, as shown in FIG. 15, the cooler 32c and compressor which were provided in each showcase 30 A low temperature side refrigerant circuit 71 composed of 71a, a high temperature side refrigerant circuit 72 composed of a compressor 72a, a condenser 72b and a regeneration condenser 10d, a high pressure side refrigerant of the low temperature side refrigerant circuit 71, and a low pressure side of the high temperature side refrigerant circuit 72. Even when the regeneration condenser 10d of the dual refrigeration cycle 70 provided with the heat exchanger 73 for heat exchange of the refrigerant is used as a heating means, the refrigerant is adsorbed on the desiccant rotor 10c in the same manner. It is possible to heat the air to release moisture. Further, as shown in FIG. 16, each of the showcases 30 includes a refrigerant circuit 81 including a cooler 32 c, a compressor 81 a and a condenser 81 b, and a compressor 82 a and a regeneration condenser 10 d. Of the supercooling refrigerant circuit 82 for supercooling the refrigerant flowing out of the condenser 81b, and heat exchange capable of heat exchange between the refrigerant discharged from the condenser 81b of the refrigerant circuit 81 and the low-pressure side refrigerant of the supercooling refrigerant circuit 82 Similarly, it is possible to heat the air for releasing the moisture adsorbed on the desiccant rotor 10c even if the regenerating condenser 10d of the refrigeration cycle provided with the vessel 83 is used as the heating means. In this case, when the cooling load of the showcase 30 is small during the winter season and the outside air circulation operation is performed, it is not necessary to supercool the refrigerant flowing through the refrigerant circuit 81 by the subcooling refrigerant circuit 82, and the desiccant rotor 10c is also configured. Since it has stopped, the compressor 82a can be stopped. Thereby, reduction of energy consumption can be aimed at.

  In the first and second embodiments, the cold air inflow passage 31g and the cold air outflow passage 31i are preliminarily incorporated in the showcase body 31. However, as shown in FIG. Further, the cool air inflow passage 33a and the cold air outflow passage 33b may be formed by attaching duct members to the upper surface and the back surface of the conventional showcase body 31 that does not have the cold air outflow passage 31i.

  In the first and second embodiments, a part of the cool air in the lower part of the passage located in front of the showcase 30 is dehumidified by the desiccant rotor 10c and then heat-exchanged with other cool air so that the air in the showcase 30 While the outside of the curtain is circulated and the cold air circulation operation and the outside air circulation operation can be switched, as shown in FIG. 18, the cold air in the lower part of the passage located in front of the showcase 30 is transferred to the desiccant rotor 10c. The absolute humidity of the cold air discharged from the cold air discharge port 31j can be reduced even if the ventilation unit 90 dedicated to the cold air circulation operation that is circulated outside the air curtain of the showcase 30 after being dehumidified by the Condensation near 31j can be prevented. Moreover, the absolute humidity of the air which flows into the product cooling ventilation path 32 from the air inlet 32d of the showcase 30 can be reduced, and the frosting amount of the cooler 32c can be reduced. Furthermore, since the enthalpy does not change even if the cold air discharged from the cold air discharge port 31j is dehumidified by the desiccant rotor 10c, the cooling load of the showcase 30 does not increase.

  Moreover, in the said 1st and 2nd embodiment, in order to heat the air which is provided between the desiccant rotor 10c of the 1st ventilation path 11, and the 1st sensible heat exchanger 10a, and distribute | circulates the 1st ventilation path 11. In FIG. 19, the regeneration condenser 10d is connected to the refrigerant circuit 40. As shown in FIG. 19, the second ventilation path 12 is provided downstream of the first sensible heat exchanger 10a. 12 is connected to the refrigerant circuit 40 in parallel with the regeneration condenser 10d, and the refrigerant flow path discharged from the compressor 41 by the on-off valves 45 and 46 is connected to the refrigerant circuit 40 in parallel with the regeneration condenser 10d. You may make it switchably provide in the condenser 10d for reproduction | regeneration, or the condenser 10e side for cold air heating. In this case, during the cold air circulation operation of the ventilation unit 10 in summer or the like, the flow path of the refrigerant circuit 40 is set on the regeneration condenser 10d side by opening the on-off valve 45 and closing the on-off valve 46, so that the winter season etc. During the outside air circulation operation of the ventilation unit 10, the on-off valve 45 is closed and the on-off valve 46 is opened, thereby setting the flow path of the refrigerant circuit 40 to the cold air heating condenser 10 e side. As a result, during the outdoor air circulation operation of the ventilation unit 10 such as in winter, the cold air in front of the showcase 30 that circulates through the second ventilation path 12 is heated by the cold air heating condenser 10e and the air in the air conditioner 20 Since it is inhaled to the inhalation side, it is possible to use the exhaust heat conventionally discharged to the outside for heating in the store A.

  In the first and second embodiments, the product cooling ventilation path 32 on the back side of the showcase 30 is partitioned by the partition plate 32a into the product storage portion 31e side and the heat insulating wall 31a side, and the product cooling ventilation on the back side. Although the cooler 32c is provided on the product storage portion 31e side of the path 32 to form an air curtain having different temperatures on the inside and outside of the product storage portion 31e, the product cooling ventilation path 32 on the back side is divided into the partition plate 32a. The cooler 32c may be provided without partitioning by the air curtain to form the air curtain.

  Further, in the first and second embodiments, the cold air and the outside air supplied into the store A are shown to flow into the air intake side of the air conditioner 20, but the ceiling or wall surface in the store A Even if the cold air and the outside air are directly discharged into the store A from the air discharge port provided in, the cooling load and the heating load can be similarly reduced.

  In the first and second embodiments, the desiccant rotor 10c is used as a dehumidifying member. However, a batch type in which the moisture adsorption side and the regeneration side of the element are switched by a damper may be used.

  In the first and second embodiments, the first and second sensible heat exchangers are fixed cross flow sensible heat exchangers. However, a rotary sensible heat exchanger may be used. .

  Moreover, in the said 2nd Embodiment, it provided in each showcase main body 31 as the humidifier 60 for humidifying the air which distribute | circulates the upstream of the 1st sensible heat exchanger 10a of the 1st ventilation path 11. As shown in FIG. The drain water generated by the dew condensation or defrosting operation generated in the cooler 32c is pumped by the pump 61, and the drain water pumped by the pump 61 is sprayed into the first ventilation path 11 from the spray nozzle 62. However, a humidifying material may be provided in the first ventilation path 11 and water may be dropped on the humidifying material, or water may be directly brought into contact with the first sensible heat exchanger 10a. Thereby, the air which distribute | circulates the upstream of the 1st sensible heat exchanger 10a of the 1st ventilation path 11 can be humidified like the said 2nd Embodiment. The water used for humidification may be general water supply.

Schematic block diagram of a refrigeration air conditioning system showing a wind circuit showing the first embodiment of the present invention Schematic configuration diagram of a refrigeration air conditioning system showing a refrigerant circuit Side cross-sectional view of showcase Block diagram showing the control system Schematic configuration diagram of a refrigeration air conditioning system showing the air flow path during cold air circulation operation Schematic configuration diagram of a refrigeration and air conditioning system showing air flow paths during outdoor air circulation operation Air diagram showing the air condition during cold air circulation operation Air diagram showing the air condition during outdoor air circulation operation Flow chart for control of operation switching of ventilation unit Flow chart regarding control of air flow rate of fan for showcase Schematic block diagram of the refrigerating and air-conditioning system showing the refrigerant circuit and drain water circuit showing the second embodiment of the present invention The perspective view of the 1st sensible heat exchanger which shows a bypass circuit Air diagram showing the air condition during cold air circulation operation Air diagram showing the state of air when outside air is circulated through the bypass circuit Schematic configuration diagram of a refrigerating and air-conditioning system showing other refrigerant circuits Schematic configuration diagram of a refrigerating and air-conditioning system showing other refrigerant circuits Side sectional view of showcase showing other examples Schematic configuration diagram of a refrigeration air conditioning system showing other wind circuits Schematic configuration diagram of a refrigerating and air-conditioning system showing other refrigerant circuits

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Ventilation unit, 10a ... 1st sensible heat exchanger, 10b ... 2nd sensible heat exchanger, 10c ... Desiccant rotor, 10d ... Regeneration condenser, 10e ... Condenser for cold air heating, 11 ... 1st ventilation path, 11a ... 1st blower, 12 ... 2nd ventilation path, 12a ... 2nd blower, 13 ... 3rd ventilation path, 13a ... 3rd blower, 14 ... 4th ventilation path, 14a ... 4th blower, 15 ... 5th ventilation Road, 15a ... 1st damper, 16 ... 6th ventilation path, 16a ... 2nd damper, 17 ... 7th ventilation path, 18 ... Bypass ventilation path, 18a ... 4th damper, 20 ... Air conditioner, 30 ... Showcase 31 ... Showcase body, 31g ... Cold air inlet, 31h ... Cold air inlet, 31i ... Cold air outlet, 31j ... Cold air outlet, 32 ... Merchandise cooling air passage, 32b ... Showcase blower, 32c ... Cooler, 32d ... Air intake port, 32e Air outlet, 40 ... refrigerant circuit, 41 ... compressor, 50 ... control unit, 51 ... first temperature / humidity detector, 52 ... second temperature / humidity detector, 53 ... first temperature detector, 54 ... second temperature Detector 55 ... Memory part 60 ... Humidifier 61 ... Pump 62 ... Spray nozzle 70 ... Dual refrigeration cycle 71 ... Low temperature side refrigerant circuit 71a ... Compressor 72 ... High temperature side refrigerant circuit 72a ... Compressor, 72b ... condenser, 73 ... heat exchanger.

Claims (14)

An opening is provided on the front surface, and a showcase that forms an air curtain in the opening by circulating air cooled by a cooler;
Cold air suction means for sucking cold air leaking from the opening of the showcase and stagnating on the front side of the showcase;
A dehumidifying means for dehumidifying the cold air sucked by the cold air sucking means;
Cold air discharge means for discharging the dehumidified cold air so as to cover the front side of the air curtain formed in the showcase ;
Sensible heat exchange means for showcase for sensible heat exchange between cold air whose temperature has been increased by dehumidification means and cold air sucked by the cold air suction means;
Cold air circulation means for circulating cold air whose temperature has been increased by sensible heat exchange by the sensible heat exchange means for showcases, into the room where the showcase is installed ,
The dehumidifying means is configured to adsorb moisture in the air with a hygroscopic dehumidifying member and heat the dehumidifying member with exhaust heat to release the moisture of the dehumidifying member and regenerate the dehumidifying member. Refrigeration air conditioning system. Ventilation means for discharging indoor air in which the showcase is installed to the outside and supplying the outdoor air to the room;
Sensible heat exchange means for ventilation for exchanging sensible heat between indoor air exhausted outdoors by the ventilation means and outdoor air supplied indoors;
2. Heating means for heating indoor air that has undergone sensible heat exchange with outdoor air by means of sensible heat exchange means for ventilation as regeneration air that releases moisture adsorbed by the dehumidifying member. The refrigeration air conditioning system described. A refrigerant circuit comprising the cooler, a compressor for circulating the refrigerant, and a condenser for discharging the heat absorbed in the cooler;
The refrigerating and air-conditioning system according to claim 2, wherein a condenser of a refrigerant circuit is used as the heating means. The cooler and a low-temperature side refrigerant circuit comprising a compressor for circulating the refrigerant;
A high temperature side refrigerant circuit comprising a compressor for circulating the refrigerant, and a condenser for discharging the heat absorbed in the cooler;
A heat exchanger that exchanges heat between the refrigerant flowing through the low-temperature side refrigerant circuit and the refrigerant flowing through the high-temperature side refrigerant circuit;
The refrigerating and air-conditioning system according to claim 2, wherein a condenser of a high-temperature side refrigerant circuit is used as the heating means. The refrigerating and air-conditioning system according to claim 2, further comprising a humidifying unit that humidifies indoor air before sensible heat exchange is performed by the sensible heat exchange unit for ventilation. The refrigerating and air-conditioning system according to claim 5, wherein dew condensation water generated during indoor cooling operation or showcase cooling operation is used as the water used for the humidifying means. The refrigerating and air-conditioning system according to claim 2, wherein a sensible heat exchanger having a bypass passage is used as the sensible heat exchange means for ventilation. The refrigerating and air-conditioning system according to claim 1, further comprising outside air discharge means for discharging outdoor air so as to cover a front side of an air curtain formed in the showcase. Cold air inhaling means for inhaling cold air leaking from the opening of the showcase and stagnating on the front side of the showcase;
Sensible heat exchange means for air conditioning for sensible heat exchange between cold air sucked by the cold air suction means and room air; and
Cold air circulation means for circulating cold air heat-exchanged with indoor air by the sensible heat exchange means for air conditioning;
The refrigerating and air-conditioning system according to claim 8, further comprising exhaust means for discharging indoor air heat-exchanged with cold air by air-conditioning sensible heat exchange means to the outside. The refrigerating and air-conditioning system according to claim 9, further comprising cold air heating means for heating the cold air circulated indoors by the cold air circulation means. Comprising a refrigerant circuit having the cooler and a condenser for discharging the heat absorbed in the cooler;
The refrigerating and air-conditioning system according to claim 10, wherein a condenser of a refrigerant circuit is used as the cold air heating means. A cold air temperature / humidity detector for detecting the temperature and humidity of the cold air discharged by the cold air discharge means;
An outside air temperature and humidity detector for detecting the temperature and humidity of the outdoor air;
An enthalpy calculating means for calculating the enthalpy of cold air from the detected temperature and detected humidity of the cold air temperature / humidity detector, and calculating the enthalpy of outdoor air from the detected temperature and detected humidity of the outside air temperature / humidity detector,
Enthalpy storage means for storing the calculated cold enthalpy;
When the enthalpy of cool air stored in the enthalpy storage means is smaller than the enthalpy of outdoor air, the cool air discharge means discharges cool air so as to cover the front side of the air curtain, and the enthalpy of cool air stored in the enthalpy storage means is The refrigerating and air-conditioning system according to claim 8, further comprising discharge air switching control means for discharging the outdoor air so as to cover the front side of the air curtain by the outside air discharge means when it is larger than the enthalpy of the outdoor air. system. A blower with variable air flow to form the air curtain;
An upper temperature detector for detecting the temperature of the upper part in the showcase;
A lower temperature detector for detecting the lower temperature in the showcase;
When the detected temperature difference between the detected temperature of the upper temperature detector and the detected temperature of the lower temperature detector becomes smaller than a predetermined first set temperature difference, the air flow rate of the blower is decreased, and the detected temperature difference becomes the first set temperature. becomes greater than the second predetermined temperature difference is greater than the temperature difference, refrigeration and air conditioning system of claim 1 or 8, wherein in that a blowing amount control means for increasing the blowing rate of the blower. The refrigerating and air-conditioning system according to claim 1 or 8, wherein a ventilation path that is formed separately from the showcase body and discharges air to the front surface of the showcase is attached to the upper surface side of the showcase.

Images