JP2018132225A

JP2018132225A - Open Showcase

Info

Publication number: JP2018132225A
Application number: JP2017024859A
Authority: JP
Inventors: 昌紀野口; Masanori Noguchi; 亘根岸; Wataru Negishi; 中西　一裕; Kazuhiro Nakanishi; 一裕中西; 早利中村; Satoshi Nakamura
Original assignee: Fukushima Industries Corp
Current assignee: Fukushima Galilei Co Ltd
Priority date: 2017-02-14
Filing date: 2017-02-14
Publication date: 2018-08-23
Anticipated expiration: 2037-02-14
Also published as: JP6752738B2

Abstract

PROBLEM TO BE SOLVED: To provide an open showcase capable of preventing incomplete cool air from being blown out of an outlet by performing defrosting operation, suppressing rise in temperature in a showroom, and maintaining freshness of products to be exhibited.SOLUTION: A controller C supplies, refrigerant liquid for a main evaporator 14 and blocks supply of the refrigerant liquid for the auxiliary evaporator 15 in the state that electrification to a heat source 38 is stopped during steady state operation and blocks supply of the refrigerant liquid for the main evaporator 14 and supplies the refrigerant liquid for the auxiliary evaporator 15 in the state that the heat source 38 is electrified during the defrosting operation. The controller C supplies the refrigerant liquid for the auxiliary evaporator 15 and starts precooling operation in prior to block of supply of the refrigerant liquid for the main evaporator 14 when the defrosting operation starts. Until a prescribed time passes after the refrigerant liquid supplied for the main evaporator 14 is started when defrosting operation is over, supply of the refrigerant liquid for the auxiliary evaporator 15 is continued to perform refrigerating operation.SELECTED DRAWING: Figure 3

Description

本発明は、主蒸発器の除霜時に冷気通路を流れる循環空気を冷却するための補助蒸発器を備えたオープンショーケースに関する。 The present invention relates to an open showcase provided with an auxiliary evaporator for cooling circulating air flowing through a cold air passage when a main evaporator is defrosted.

この種のオープンショーケースは、例えば本出願人に係る特許文献１に公知である。係る特許文献１の平型オープンショーケースでは、冷気循環通路（冷気通路）の内部に、主蒸発器と送風ファンとが配置されており、冷気循環通路の吹出口と主蒸発器との間に、主蒸発器から出る除霜用の温風を冷却する補助蒸発器が配置されている。定常運転時においては、主蒸発器は冷媒液が供給され、補助蒸発器は冷媒液の供給が停止されている。主蒸発器に付着した霜を融解除去するために、定常運転から除霜運転へと切り換わる際には、除霜ヒーターへの通電を開始したうえで、主蒸発器への冷媒液の供給を停止し、同時に補助蒸発器への冷媒液の供給を開始する。これにより、除霜ヒーターで加熱された循環空気で主蒸発器の霜を融解除去する。このとき、主蒸発器を通過した循環空気を、通路下流側の補助蒸発器で冷却して、吹出口から適正な温度の冷気が吹出されるようにしている。逆に除霜運転から定常運転へと切り換わる際には、除霜ヒーターへの通電を停止したうえで、主蒸発器への冷媒液の供給を開始すると同時に、補助蒸発器へ冷媒液の供給を停止している。 This type of open showcase is known, for example, from US Pat. In the flat open showcase of Patent Document 1, the main evaporator and the blower fan are arranged inside the cold air circulation passage (cold air passage), and between the outlet of the cold air circulation passage and the main evaporator. An auxiliary evaporator for cooling hot air for defrosting from the main evaporator is disposed. During steady operation, the main evaporator is supplied with refrigerant liquid, and the auxiliary evaporator is not supplied with refrigerant liquid. When switching from steady operation to defrosting operation in order to melt and remove frost adhering to the main evaporator, start supplying power to the defrosting heater and then supply the refrigerant liquid to the main evaporator. At the same time, supply of the refrigerant liquid to the auxiliary evaporator is started. Thereby, the frost of the main evaporator is thawed and removed by circulating air heated by the defrosting heater. At this time, the circulating air that has passed through the main evaporator is cooled by the auxiliary evaporator on the downstream side of the passage so that cool air at an appropriate temperature is blown out from the outlet. Conversely, when switching from the defrosting operation to the steady operation, the energization of the defrosting heater is stopped and the supply of the refrigerant liquid to the main evaporator is started at the same time as the supply of the refrigerant liquid to the auxiliary evaporator. Has stopped.

特開２００６−４６８４３号公報JP 2006-46843 A

特許文献１の平型オープンショーケースでは、定常運転から除霜運転へと切り換わるときには、主蒸発器への冷媒液の供給を停止するのと同時に、補助蒸発器への冷媒液の供給を開始する。また、除霜運転から定常運転へと切り換わるときには、主蒸発器への冷媒液の供給を開始するのと同時に、補助蒸発器への冷媒液の供給を停止する。そのため、除霜運転開始時における補助蒸発器、および除霜運転終了時における主蒸発器は、通過する循環空気を十分に冷却できる低温にまで温度が低下しておらず、通過する循環空気と熱交換を行って適正に冷却することができない。これにより、主蒸発器および補助蒸発器の温度が低下するまでのしばらくの間、吹出口から適正な温度より高温の冷気（以下、不完全冷気と言う）が吹出される問題があった。このように、不完全冷気が吹出口から吹出されると、陳列室内の温度が上昇し、それに伴って陳列された商品の温度が上昇するので、商品の鮮度が低下するのを避けられない。とくに陳列される商品が鮮魚、刺身あるいは精肉などの生鮮食品の場合には、温度上昇による鮮度低下が著しい。 In the flat open showcase of Patent Document 1, when switching from steady operation to defrosting operation, supply of refrigerant liquid to the auxiliary evaporator is started at the same time as supply of refrigerant liquid to the main evaporator is stopped. To do. Further, when switching from the defrosting operation to the steady operation, the supply of the refrigerant liquid to the auxiliary evaporator is stopped simultaneously with the start of the supply of the refrigerant liquid to the main evaporator. Therefore, the temperature of the auxiliary evaporator at the start of the defrosting operation and the main evaporator at the end of the defrosting operation are not lowered to a low temperature at which the circulating air passing therethrough can be sufficiently cooled. It cannot be cooled properly after replacement. As a result, there has been a problem that cold air (hereinafter referred to as incomplete cold air) having a temperature higher than an appropriate temperature is blown out from the air outlet for a while until the temperatures of the main evaporator and the auxiliary evaporator are lowered. As described above, when incomplete cold air is blown out from the air outlet, the temperature in the display chamber rises, and the temperature of the displayed merchandise rises accordingly, so that the freshness of the merchandise cannot be avoided. In particular, when the displayed product is a fresh food such as fresh fish, sashimi, or meat, the freshness is significantly reduced due to a rise in temperature.

本発明の目的は、除霜運転を行うことにより、吹出口から不完全冷気が吹出されるのを防止して、陳列室内の温度の安定化を図り、従って陳列された商品の鮮度を維持することができるオープンショーケースを提供することにある。 An object of the present invention is to perform a defrosting operation to prevent incomplete cold air from being blown out from the air outlet, thereby stabilizing the temperature in the display room and thus maintaining the freshness of the displayed goods. It is to provide an open showcase that can.

本発明は、吸込口４から吹出口５へと至る冷気通路６に配置される、主蒸発器１４、補助蒸発器１５、および主蒸発器１４を加熱する熱源３８と、これらの機器の作動状態を制御する制御装置Ｃとを含み、補助蒸発器１５が、主蒸発器１４と吹出口５の間の冷気通路６に配置されているオープンショーケースを対象とする。制御装置Ｃは、定常運転時には、熱源３８への通電を停止した状態で、主蒸発器１４へ冷媒液を供給し、かつ補助蒸発器１５への冷媒液の供給を遮断するように構成され、除霜運転時には、熱源３８へ通電した状態で、主蒸発器１４への冷媒液の供給を遮断し、かつ補助蒸発器１５へ冷媒液を供給するように構成されている。制御装置Ｃは、除霜運転開始時における主蒸発器１４への冷媒液の供給の遮断に先行して、補助蒸発器１５へ冷媒液を供給して予冷運転を開始し、除霜運転終了時における主蒸発器１４への冷媒液の供給開始から所定時間が経過するまで、補助蒸発器１５への冷媒液の供給を継続して保冷運転を行うように構成されていることを特徴とする。 The present invention includes a main evaporator 14, an auxiliary evaporator 15, and a heat source 38 for heating the main evaporator 14, which are disposed in a cool air passage 6 extending from the suction port 4 to the blower outlet 5, and operating states of these devices. The auxiliary evaporator 15 is an open showcase disposed in the cool air passage 6 between the main evaporator 14 and the outlet 5. The control device C is configured to supply the refrigerant liquid to the main evaporator 14 and shut off the supply of the refrigerant liquid to the auxiliary evaporator 15 in a state where the energization to the heat source 38 is stopped during the steady operation. During the defrosting operation, the supply of the refrigerant liquid to the main evaporator 14 is shut off and the refrigerant liquid is supplied to the auxiliary evaporator 15 while the heat source 38 is energized. Prior to the interruption of the supply of the refrigerant liquid to the main evaporator 14 at the start of the defrosting operation, the controller C supplies the refrigerant liquid to the auxiliary evaporator 15 to start the precooling operation, and at the end of the defrosting operation. In this embodiment, the refrigerant liquid is continuously supplied to the auxiliary evaporator 15 until a predetermined time elapses from the start of supply of the refrigerant liquid to the main evaporator 14.

制御装置Ｃは、主蒸発器１４への着霜の有無にかかわらず、等時間間隔Ｔ毎に所定時間だけ除霜運転を行うように構成することができる。 The control device C can be configured to perform the defrosting operation for a predetermined time every equal time interval T regardless of whether or not the main evaporator 14 is frosted.

制御装置Ｃは、２４時間毎に、両蒸発器１４・１５への冷媒液の供給を遮断した状態で、主蒸発器１４の着霜が無くなったことを、主蒸発器１４に配置した着霜センサ３９で検知するまで熱源３８への通電を継続する完全霜取り運転を行うように構成することができる。 The control device C indicates that the main evaporator 14 has no frost every 24 hours while the supply of the refrigerant liquid to both the evaporators 14 and 15 is cut off. A complete defrosting operation in which energization of the heat source 38 is continued until detection by the sensor 39 can be performed.

本発明に係るオープンショーケースにおいては、除霜運転開始時における主蒸発器１４への冷媒液の供給の遮断に先行して、補助蒸発器１５の予冷運転を行い、除霜運転終了時における主蒸発器１４への冷媒液の供給開始後も、補助蒸発器１５の保冷運転を行うようにした。このように、補助蒸発器１５の予冷運転を行うと、除霜運転が開始されたときには、補助蒸発器１５は十分に温度が低下しているので、補助蒸発器１５を通過する循環空気を確実に冷却して、吹出口５から適正な温度の冷気を吹出すことができる。また、補助蒸発器１５の保冷運転を行うと、主蒸発器１４の温度が十分に低下するまで、主蒸発器１４を通過した循環空気を補助蒸発器１５で再度冷却して、吹出口５から適正な温度の冷気を吹出すことができる。以上のように、本発明のオープンショーケースによれば、除霜運転開始後および終了後のしばらくの間、吹出口５から不完全冷気が吹出されるという従来のオープンショーケースの問題を解決することができる。これにより、陳列室３内の温度の安定化を図り、従って陳列された商品の鮮度を維持することができる。 In the open showcase according to the present invention, the auxiliary evaporator 15 is precooled before the refrigerant liquid supply to the main evaporator 14 is interrupted at the start of the defrosting operation, and the main defrosting operation is completed. Even after the supply of the refrigerant liquid to the evaporator 14 was started, the auxiliary evaporator 15 was kept cold. Thus, when the precooling operation of the auxiliary evaporator 15 is performed, when the defrosting operation is started, the temperature of the auxiliary evaporator 15 is sufficiently lowered, so that the circulating air passing through the auxiliary evaporator 15 is surely obtained. Then, the cool air at an appropriate temperature can be blown out from the outlet 5. When the auxiliary evaporator 15 is kept cold, the circulating air that has passed through the main evaporator 14 is cooled again by the auxiliary evaporator 15 until the temperature of the main evaporator 14 is sufficiently lowered. Cold air at an appropriate temperature can be blown out. As described above, according to the open showcase of the present invention, the problem of the conventional open showcase in which incomplete cold air is blown out from the outlet 5 for a while after the start of the defrosting operation and after the end of the defrosting operation is solved. be able to. As a result, the temperature in the display chamber 3 can be stabilized, and thus the freshness of the displayed goods can be maintained.

制御装置Ｃは、主蒸発器１４への着霜の有無にかかわらず、等時間間隔Ｔ毎に所定時間だけ除霜運転を行うように構成した。このように、等時間間隔Ｔ毎に除霜運転を行うと、主蒸発器１４において霜が大きく成長するのを阻止できる。これにより、多量の霜が主蒸発器１４に付着することによる、主蒸発器１４と循環空気との熱交換効率の低下を防止でき、吹出口５から不完全冷気が吹出されるのを防止できる。また、本発明のオープンショーケースは、除霜運転を行った際でも適正な温度の冷気を吹出すことができるので、短いサイクルで除霜運転を行った場合でも、陳列室３内の温度が上昇するのを抑制できる。これにより、頻繁に除霜運転を行うことができるので、多量の霜が主蒸発器１４に付着するのを確実に阻止し、効率よく主蒸発器１４と循環空気との熱交換を行って、常に吹出口５から適正な温度の冷気を安定して吹出すことができる。 The control device C is configured to perform the defrosting operation for a predetermined time at every equal time interval T regardless of the presence or absence of frost formation on the main evaporator 14. As described above, when the defrosting operation is performed at regular time intervals T, it is possible to prevent frost from growing largely in the main evaporator 14. Thereby, the fall of the heat exchange efficiency of the main evaporator 14 and circulating air by a large amount of frost adhering to the main evaporator 14 can be prevented, and incomplete cold air can be prevented from being blown out from the outlet 5. . In addition, since the open showcase of the present invention can blow out cold air at an appropriate temperature even when performing the defrosting operation, the temperature in the display chamber 3 can be maintained even when the defrosting operation is performed in a short cycle. The rise can be suppressed. As a result, frequent defrosting operations can be performed, so that a large amount of frost is reliably prevented from adhering to the main evaporator 14, and heat exchange between the main evaporator 14 and the circulating air is performed efficiently. It is always possible to stably cool air having an appropriate temperature from the air outlet 5.

制御装置Ｃは、２４時間毎に、両蒸発器１４・１５への冷媒液の供給を遮断した状態で、主蒸発器１４の着霜が無くなったことを、主蒸発器１４に配置した着霜センサ３９で検知するまで熱源３８への通電を継続する完全霜取り運転を行うように構成した。このように、２４時間毎に完全霜取り運転を行うと、除霜運転で主蒸発器１４の霜を完全に融解除去できなかった場合でも、２４時間毎に主蒸発器１４に付着した霜をすべて融解除去できる。従って、２４時間に１回、主蒸発器１４の霜を完全に除去して、定常運転の間に、主蒸発器１４において霜が大きく成長するのを確実に阻止できる。なお、完全霜取り運転は両蒸発器１４・１５への冷媒液の供給を遮断して行うので、吹出口５から不完全冷気が吹出されるおそれがある。そのため、完全霜取り運転は店舗の閉店時間内に設定しておくことが好ましい。これは、店舗の閉店時間においては、陳列室３の商品は回収されて空の状態であるか、あるいは陳列商品は僅かであるため、仮に陳列室３の温度が上昇したとしても商品に与える影響を抑えることができるからである。 The control device C indicates that the main evaporator 14 has no frost every 24 hours while the supply of the refrigerant liquid to both the evaporators 14 and 15 is cut off. A complete defrosting operation in which energization to the heat source 38 is continued until detection by the sensor 39 is performed. As described above, when the complete defrosting operation is performed every 24 hours, even if the frost of the main evaporator 14 cannot be completely thawed and removed by the defrosting operation, all the frost adhered to the main evaporator 14 every 24 hours is removed. Can be thawed away. Therefore, once every 24 hours, the frost of the main evaporator 14 is completely removed, and it is possible to reliably prevent the frost from growing greatly in the main evaporator 14 during the steady operation. In addition, since the complete defrosting operation is performed by shutting off the supply of the refrigerant liquid to both the evaporators 14 and 15, incomplete cold air may be blown out from the outlet 5. Therefore, it is preferable to set the complete defrosting operation within the store closing time. This is because, during the closing time of the store, the goods in the display room 3 are collected and empty, or the display goods are few, so even if the temperature of the display room 3 rises, it has an effect on the goods. It is because it can suppress.

本発明に係るオープンショーケースの運転動作を示すタイミングチャートである。It is a timing chart which shows the driving | running operation | movement of the open showcase which concerns on this invention. オープンショーケースの概略構成を示す縦断側面図である。It is a vertical side view which shows schematic structure of an open showcase. 冷凍機器を構成する機器の接続形態を示す説明図である。It is explanatory drawing which shows the connection form of the apparatus which comprises refrigeration equipment.

（実施例）図１から図３に、本発明を多段型のオープンショーケースに適用した実施例を示す。本実施例における前後、左右、上下とは、図２に示す交差矢印と、各矢印の近傍に表記した前後、左右、上下の表示に従う。図２においてオープンショーケースは、前面が開口する断熱箱体で形成される本体ケース１と、本体ケース１の内側に配置される内ケース２とを備えており、内ケース２の内部が陳列室３として区画されている。両ケース１・２の間には、陳列室３の下側前縁に設けられる吸込口４から陳列室３の上側前縁に設けられる吹出口５へと至る冷気通路６が区画されている。符号７は上下多段状に設けられる板ガラス製の棚板であり、棚板７の左右端にそれぞれ固定された棚ブラケット８の後端が内ケース２の後壁で支持されている。 (Embodiment) FIGS. 1 to 3 show an embodiment in which the present invention is applied to a multistage open showcase. In the present embodiment, front and rear, left and right, and up and down follow the cross arrows shown in FIG. In FIG. 2, the open showcase includes a main body case 1 formed of a heat insulating box whose front surface is open, and an inner case 2 disposed inside the main body case 1, and the inside of the inner case 2 is a display chamber. It is divided as 3. A cool air passage 6 is defined between the cases 1 and 2 from the suction port 4 provided at the lower front edge of the display chamber 3 to the air outlet 5 provided at the upper front edge of the display chamber 3. Reference numeral 7 denotes a shelf made of flat glass provided in upper and lower stages, and the rear ends of the shelf brackets 8 fixed to the left and right ends of the shelf plate 7 are supported by the rear wall of the inner case 2.

本体ケース１の下方に設けられた機械室１１には、冷凍機器を構成する圧縮機１２、凝縮器１３などが配置されており、圧縮機１２は制御装置Ｃで制御されている。冷気通路６の縦通路部分には主蒸発器１４および補助蒸発器１５が上下に配置されており、補助蒸発器１５は、後述する主蒸発器１４の除霜時に冷気通路６を流れる循環空気を冷却するために設けられている。これら圧縮機１２、凝縮器１３、主蒸発器１４、補助蒸発器１５は冷媒配管１６で接続されており、詳細な接続形態は後述する。符号１７は、圧縮機１２および凝縮器１３を空冷するための空冷ファンである。主蒸発器１４および補助蒸発器１５は、いずれも蛇行状に折り曲げた冷媒管に一群のフィンを備えている。 In the machine room 11 provided below the main body case 1, a compressor 12, a condenser 13, and the like constituting refrigeration equipment are arranged, and the compressor 12 is controlled by the control device C. A main evaporator 14 and an auxiliary evaporator 15 are arranged vertically in the vertical passage portion of the cold air passage 6. The auxiliary evaporator 15 circulates the circulating air flowing through the cold air passage 6 during defrosting of the main evaporator 14 described later. It is provided for cooling. The compressor 12, the condenser 13, the main evaporator 14, and the auxiliary evaporator 15 are connected by a refrigerant pipe 16, and a detailed connection form will be described later. Reference numeral 17 denotes an air cooling fan for air cooling the compressor 12 and the condenser 13. The main evaporator 14 and the auxiliary evaporator 15 are each provided with a group of fins in a refrigerant pipe bent in a meandering manner.

冷気通路６の下通路には制御装置Ｃで制御される送風ファン２０が配置されており、オープンショーケースの電源が投入されている状態において送風ファン２０は常時駆動されている。送風ファン２０が駆動されると、吸込口４から冷気通路６へと導入された循環空気が、主蒸発器１４および補助蒸発器１５を通過する際に熱交換されて冷却され、冷気通路６の上通路を経て吹出口５から冷気が吹出される。吹出口５から吹出された冷気は、陳列室３の前面を覆うようにエアカーテンを形成し、再び吸込口４から冷気通路６へと導入される。熱交換前の循環空気の一部は、冷気通路６の縦通路および上通路に仕切壁２１で区画されたバイパス通路２２を介して吹出口５の前側に隣接する吹出口２３から吹出される。これにより、吹出口５から吹出される冷気によるエアカーテンの外側に、さらにエアカーテンを形成している。このように、エアカーテンを２重に形成すると、吹出口５から吹出された冷気と周囲の外気とが混ざり合うのを外側のエアカーテンで可及的に阻止できるので、陳列室３の温度の安定化を図ることができる。 A blower fan 20 controlled by the control device C is disposed in the lower passage of the cool air passage 6, and the blower fan 20 is always driven in a state where the power of the open showcase is turned on. When the blower fan 20 is driven, the circulating air introduced from the suction port 4 to the cold air passage 6 is cooled by heat exchange when passing through the main evaporator 14 and the auxiliary evaporator 15. Cold air is blown out from the outlet 5 through the upper passage. The cold air blown out from the air outlet 5 forms an air curtain so as to cover the front surface of the display chamber 3, and is again introduced from the suction port 4 into the cold air passage 6. A part of the circulating air before heat exchange is blown out from the outlet 23 adjacent to the front side of the outlet 5 through the bypass passage 22 partitioned by the partition wall 21 in the vertical passage and the upper passage of the cold passage 6. Thereby, the air curtain is further formed in the outer side of the air curtain by the cold air which blows off from the blower outlet 5. FIG. In this way, when the air curtain is doubled, the outer air curtain can prevent the cold air blown out from the outlet 5 and the surrounding outside air from being mixed as much as possible. Stabilization can be achieved.

図３に示すように、圧縮機１２、凝縮器１３、主蒸発器１４、および補助蒸発器１５などは、冷媒配管１６でループ状に接続されている。冷媒配管１６の一部は、第１分岐管路２６と第２分岐管路２７の二股状に分岐しており、第１分岐管路２６に主蒸発器１４が接続され、第２分岐管路２７に補助蒸発器１５が接続されて、主蒸発器１４と補助蒸発器１５とは冷媒配管１６に並列に接続されている。また、凝縮器１３の下流側にはドライヤ２８が接続され、各蒸発器１４・１５の上流側には、キャピラリチューブからなる膨張部２９がそれぞれ接続され、圧縮機１２の上流側にはアキュムレータ３０が接続されている。 As shown in FIG. 3, the compressor 12, the condenser 13, the main evaporator 14, the auxiliary evaporator 15, and the like are connected in a loop with a refrigerant pipe 16. A part of the refrigerant pipe 16 branches into a bifurcated shape of a first branch pipe 26 and a second branch pipe 27, the main evaporator 14 is connected to the first branch pipe 26, and the second branch pipe 27 is connected to the auxiliary evaporator 15, and the main evaporator 14 and the auxiliary evaporator 15 are connected in parallel to the refrigerant pipe 16. Further, a dryer 28 is connected to the downstream side of the condenser 13, an expansion part 29 made of a capillary tube is connected to the upstream side of each evaporator 14, 15, and an accumulator 30 is connected to the upstream side of the compressor 12. Is connected.

主蒸発器１４および補助蒸発器１５への冷媒液の流れを切り換えるために、凝縮器１３と、両蒸発器１４・１５との間に、制御装置Ｃで制御される流路切換弁３３が設けられている。具体的には、流路切換弁３３は、第１分岐管路２６の膨張部２９の上流側に設けられて主蒸発器１４への冷媒液の供給と遮断を行う第１電磁弁３４と、第２分岐管路２７の膨張部２９の上流側に設けられて補助蒸発器１５への冷媒液の供給と遮断を行う第２電磁弁３５とで構成されている。これら両電磁弁３４・３５の開閉状態を切り換えることで、主蒸発器１４および補助蒸発器１５への冷媒液の供給と遮断を、それぞれ独立して行えるようになっている。 In order to switch the flow of the refrigerant liquid to the main evaporator 14 and the auxiliary evaporator 15, a flow path switching valve 33 controlled by the control device C is provided between the condenser 13 and both the evaporators 14 and 15. It has been. Specifically, the flow path switching valve 33 is provided on the upstream side of the expansion portion 29 of the first branch pipe 26, and the first electromagnetic valve 34 that supplies and blocks the refrigerant liquid to the main evaporator 14, A second electromagnetic valve 35 is provided on the upstream side of the expansion portion 29 of the second branch pipe 27 and supplies and shuts off the refrigerant liquid to the auxiliary evaporator 15. By switching the open / closed state of these electromagnetic valves 34 and 35, the supply and shutoff of the refrigerant liquid to the main evaporator 14 and the auxiliary evaporator 15 can be performed independently.

オープンショーケースの定常運転時においては、第１電磁弁３４を開状態として主蒸発器１４に冷媒液が供給され、第２電磁弁３５を閉状態として補助蒸発器１５への冷媒液の供給が遮断されており、送風ファン２０で送給される循環空気は、主蒸発器１４を通過する際に熱交換されて冷却され吹出口５から吹出される。低温に維持された主蒸発器１４では、定常運転の継続に伴って通過する循環空気に含まれる水分が冷媒管およびフィンの表面で氷結して霜が付着する。霜が大きく成長すると、循環空気と冷媒管およびフィンとの接触機会が減少するので熱交換効率が低下する。これを防止するために主蒸発器１４の下面に正対する位置と、主蒸発器１４の内部に配置された除霜ヒーター（熱源）３８に通電して主蒸発器１４を加熱し、霜を融解除去する除霜運転を行う。除霜ヒーター３８に対する通電は制御装置Ｃで制御されている。除霜運転時においては、除霜ヒーター３８に通電したうえで、第１電磁弁３４を閉状態として主蒸発器１４への冷媒液の供給が遮断され、第２電磁弁３５を開状態として補助蒸発器１５に冷媒液が供給されている。送風ファン２０で送給される循環空気は、補助蒸発器１５を通過する際に熱交換されて冷却され吹出口５から吹出される。除霜運転が終了すると、第１電磁弁３４を開状態、第２電磁弁３５を閉状態として定常運転へと移行する。 During steady operation of the open showcase, the first electromagnetic valve 34 is opened and the refrigerant liquid is supplied to the main evaporator 14, and the second electromagnetic valve 35 is closed and the refrigerant liquid is supplied to the auxiliary evaporator 15. The circulating air that is shut off and fed by the blower fan 20 is heat-exchanged when passing through the main evaporator 14, cooled, and blown out from the outlet 5. In the main evaporator 14 maintained at a low temperature, moisture contained in the circulating air passing along with the continuation of the steady operation freezes on the surfaces of the refrigerant pipes and the fins, and frost adheres. If the frost grows greatly, the chance of contact between the circulating air and the refrigerant pipes and the fins decreases, so that the heat exchange efficiency decreases. In order to prevent this, the main evaporator 14 is heated by energizing the position facing the lower surface of the main evaporator 14 and the defrosting heater (heat source) 38 disposed inside the main evaporator 14 to melt the frost. Perform defrosting operation to remove. Energization of the defrosting heater 38 is controlled by the control device C. During the defrosting operation, the defrosting heater 38 is energized, the first electromagnetic valve 34 is closed, the supply of refrigerant liquid to the main evaporator 14 is shut off, and the second electromagnetic valve 35 is opened to assist. A refrigerant liquid is supplied to the evaporator 15. The circulating air fed by the blower fan 20 is heat-exchanged when passing through the auxiliary evaporator 15, cooled, and blown out from the outlet 5. When the defrosting operation is completed, the first electromagnetic valve 34 is opened and the second electromagnetic valve 35 is closed, and the operation proceeds to the steady operation.

上記のように、除霜運転の開始時および終了時に両電磁弁３４・３５の弁状態を同時に変更すると、冷媒液が供給された側の蒸発器は、通過する循環空気を十分に冷却できる低温にまで温度が低下していないので、しばらくの間循環空気を適正な温度まで冷却できない。そのため、吹出口から不完全冷気が吹出されてしまう。このように不完全冷気が吹出されるのを防止するために、本実施例においては、除霜運転開始時における主蒸発器１４への冷媒液の供給の遮断に先行して、補助蒸発器１５へ冷媒液を供給して予冷運転を開始し、除霜運転終了時における主蒸発器１４への冷媒液の供給開始から所定時間が経過するまで、補助蒸発器１５への冷媒液の供給を継続して保冷運転を行うようにした。 As described above, when the valve states of the electromagnetic valves 34 and 35 are simultaneously changed at the start and end of the defrosting operation, the evaporator on the side supplied with the refrigerant liquid has a low temperature that can sufficiently cool the circulating air passing therethrough. Since the temperature has not dropped to, the circulating air cannot be cooled to an appropriate temperature for a while. Therefore, incomplete cold air will be blown out from the blower outlet. In order to prevent incomplete cold air from being blown out in this way, in the present embodiment, the auxiliary evaporator 15 precedes the interruption of the supply of the refrigerant liquid to the main evaporator 14 at the start of the defrosting operation. The refrigerant liquid is supplied to the pre-cooling operation, and the supply of the refrigerant liquid to the auxiliary evaporator 15 is continued until a predetermined time has elapsed from the start of the supply of the refrigerant liquid to the main evaporator 14 at the end of the defrosting operation. The cold operation was performed.

具体的には、除霜運転の開始時間より所定時間前（例えば５分前）になると、第１電磁弁３４の開状態を維持したまま第２電磁弁３５を開状態として、補助蒸発器１５に冷媒液を供給する。これにより、除霜運転開始前の補助蒸発器１５は予冷される（予冷運転）。除霜運転の開始時刻になると、除霜ヒーター３８に通電したうえで、第１電磁弁３４を閉状態として主蒸発器１４への冷媒液の供給を遮断する。以降除霜運転が所定時間（例えば５分間）継続される。このとき、補助蒸発器１５は予冷運転により循環空気を十分に冷却できる低温にまで温度が低下しているので、循環空気は補助蒸発器１５を通過する際に適正な温度に冷却される。 Specifically, when a predetermined time before the start time of the defrosting operation (for example, 5 minutes before), the second electromagnetic valve 35 is opened while the first electromagnetic valve 34 is maintained open, and the auxiliary evaporator 15 is opened. Supply refrigerant liquid to Thereby, the auxiliary evaporator 15 before the start of the defrosting operation is precooled (precooling operation). At the start time of the defrosting operation, the defrosting heater 38 is energized and the first electromagnetic valve 34 is closed to cut off the supply of the refrigerant liquid to the main evaporator 14. Thereafter, the defrosting operation is continued for a predetermined time (for example, 5 minutes). At this time, since the temperature of the auxiliary evaporator 15 is lowered to a low temperature at which the circulating air can be sufficiently cooled by the pre-cooling operation, the circulating air is cooled to an appropriate temperature when passing through the auxiliary evaporator 15.

除霜運転終了時間になると、第２電磁弁３５の開状態を維持したまま、第１電磁弁３４を開状態として主蒸発器１４に冷媒液を供給する。これにより、除霜運転終了後の補助蒸発器１５は保冷される（保冷運転）。除霜運転中の主蒸発器１４は、冷媒液の供給が遮断され、さらに除霜ヒーター３８から熱の供給を受けて加熱されている。そのため、除霜運転終了直後の主蒸発器１４は、通過する循環空気を十分に冷却できるほどの低温ではない。しかし、補助蒸発器１５が保冷されているので、循環空気は補助蒸発器１５を通過する際に適正な温度に冷却される。除霜運転終了時間から所定時間経過（例えば１０分）すると、第１電磁弁３４の開状態を維持したまま第２電磁弁３５を閉状態とする。 When the defrosting operation end time is reached, the first electromagnetic valve 34 is opened and the refrigerant liquid is supplied to the main evaporator 14 while the second electromagnetic valve 35 is kept open. Thereby, the auxiliary evaporator 15 after the completion of the defrosting operation is kept cold (cooling operation). The main evaporator 14 during the defrosting operation is heated by being supplied with heat from the defrosting heater 38 while the supply of the refrigerant liquid is shut off. Therefore, the main evaporator 14 immediately after the end of the defrosting operation is not low enough to sufficiently cool the circulating air passing therethrough. However, since the auxiliary evaporator 15 is kept cold, the circulating air is cooled to an appropriate temperature when passing through the auxiliary evaporator 15. When a predetermined time elapses (for example, 10 minutes) from the defrosting operation end time, the second electromagnetic valve 35 is closed while the open state of the first electromagnetic valve 34 is maintained.

主蒸発器１４には、同蒸発器１４の表面の着霜の有無を検知する温度センサからなる着霜センサ３９が設けられている。この着霜センサ３９の検知結果に基づいて除霜運転を行うことも可能であるが、本実施例では、主蒸発器１４への着霜の有無にかかわらず、等時間間隔Ｔ毎に所定時間だけ除霜運転を行うようにした。このように、等時間間隔Ｔ毎に除霜運転を行うと、主蒸発器１４において霜が大きく成長するのを阻止できる。これにより、多量の霜が主蒸発器１４に付着することによる、主蒸発器１４と循環空気との熱交換効率の低下を防止でき、吹出口５から不完全冷気が吹出されるのを防止できる。また、本実施例のオープンショーケースは、除霜運転を行った際でも吹出口５から適正な温度の冷気を吹出すことができるので、短いサイクルで除霜運転を行った場合でも、陳列室３内の温度が上昇するのを抑制できる。これにより、頻繁に除霜運転を行うことができるので、多量の霜が主蒸発器１４に付着するのを確実に阻止し、効率よく主蒸発器１４と循環空気との熱交換を行って、常に吹出口５から適正な温度の冷気を安定して吹出すことができる。除霜運転を行う時間間隔Ｔは３時間程度に設定することが好ましく、より好ましくは２時間程度に設定するとよい。本実施例では、除霜運転を行う時間間隔Ｔを２時間に設定した。 The main evaporator 14 is provided with a frost sensor 39 including a temperature sensor that detects the presence or absence of frost on the surface of the evaporator 14. Although it is possible to perform a defrosting operation based on the detection result of the frosting sensor 39, in the present embodiment, a predetermined time every equal time interval T regardless of the presence or absence of frosting on the main evaporator 14. Only defrosting operation was performed. As described above, when the defrosting operation is performed at regular time intervals T, it is possible to prevent frost from growing largely in the main evaporator 14. Thereby, the fall of the heat exchange efficiency of the main evaporator 14 and circulating air by a large amount of frost adhering to the main evaporator 14 can be prevented, and incomplete cold air can be prevented from being blown out from the outlet 5. . Moreover, since the open showcase of a present Example can blow off the cold air of appropriate temperature from the blower outlet 5 even if it performs a defrosting operation, even if it performs a defrosting operation with a short cycle, a display room It can suppress that the temperature in 3 rises. As a result, frequent defrosting operations can be performed, so that a large amount of frost is reliably prevented from adhering to the main evaporator 14, and heat exchange between the main evaporator 14 and the circulating air is performed efficiently. It is always possible to stably cool air having an appropriate temperature from the air outlet 5. The time interval T for performing the defrosting operation is preferably set to about 3 hours, more preferably about 2 hours. In this example, the time interval T for performing the defrosting operation was set to 2 hours.

除霜運転においては、霜が大きく成長するのを阻止することが目的であり、主蒸発器１４に付着した霜の全部を融解除去できていないおそれがある。そこで本実施例のオープンショーケースでは、２４時間毎に、第１および第２電磁弁３４・３５を閉状態として両蒸発器１４・１５への冷媒液の供給を遮断した状態で、主蒸発器１４の着霜が無くなったことを、着霜センサ３９で検知するまで除霜ヒーター３８への通電を継続する完全霜取り運転を行うようにした。このとき、圧縮機１２の駆動は停止される。完全霜取り運転は、前後の除霜運転の間に行われるように設定されている。本実施例では、除霜運転を行う時間間隔Ｔを２時間に設定したので、２４時間の内に１２回の除霜運転が行われ、１回の完全霜取り運転が行われる。完全霜取り運転は両蒸発器１４・１５への冷媒液の供給を遮断して行うので、吹出口５から不完全冷気が吹出されるおそれがある。そのため、完全霜取り運転は店舗の閉店時間内に設定しておくことが好ましい。これは、店舗の閉店時間においては、陳列室３の商品は回収されて空の状態であるか、あるいは陳列商品は僅かであるため、仮に陳列室３の温度が上昇したとしても商品に与える影響を抑えることができるからである。 In the defrosting operation, the purpose is to prevent the frost from growing greatly, and there is a possibility that all of the frost adhering to the main evaporator 14 cannot be melted and removed. Therefore, in the open showcase of this embodiment, the main evaporator is closed every 24 hours with the first and second solenoid valves 34 and 35 closed and the supply of the refrigerant liquid to both the evaporators 14 and 15 is shut off. The defrosting operation in which the current supply to the defrosting heater 38 is continued until the frosting sensor 39 detects that the frosting 14 has disappeared is performed. At this time, the drive of the compressor 12 is stopped. The complete defrosting operation is set to be performed between the front and rear defrosting operations. In the present embodiment, since the time interval T for performing the defrosting operation is set to 2 hours, 12 defrosting operations are performed within 24 hours, and one complete defrosting operation is performed. Since the complete defrosting operation is performed by shutting off the supply of the refrigerant liquid to the evaporators 14 and 15, incomplete cold air may be blown out from the outlet 5. Therefore, it is preferable to set the complete defrosting operation within the store closing time. This is because, during the closing time of the store, the goods in the display room 3 are collected and empty, or the display goods are few, so even if the temperature of the display room 3 rises, it has an effect on the goods. It is because it can suppress.

上記のように、２４時間毎に完全霜取り運転を行うと、除霜運転で主蒸発器１４の霜を完全に融解除去できなかった場合でも、２４時間毎に主蒸発器１４に付着した霜をすべて融解除去できる。従って、２４時間に１回、主蒸発器１４の霜を完全に除去して、定常運転の間に主蒸発器１４において霜が大きく成長するのを確実に阻止できる。なお、完全霜取り運転は、前後の除霜運転の間に行われるように設定したが、１２回の除霜運転の内の１回を完全霜取り運転に切換えて行ってもよい。また、完全霜取り運転においても除霜運転における予冷運転と保冷運転のような制御を行ってもよい。 As described above, when the complete defrosting operation is performed every 24 hours, even if the frost of the main evaporator 14 cannot be completely thawed and removed by the defrosting operation, the frost adhered to the main evaporator 14 every 24 hours is removed. All can be thawed away. Therefore, once every 24 hours, the frost in the main evaporator 14 can be completely removed, and the frost can be reliably prevented from growing in the main evaporator 14 during the steady operation. The complete defrosting operation is set to be performed between the preceding and subsequent defrosting operations, but one of the 12 defrosting operations may be switched to the complete defrosting operation. Moreover, you may perform control like the pre-cooling driving | operation in a defrosting driving | operation, and a cold insulation driving | operation also in a complete defrosting driving | operation.

以上のように、本発明に係るオープンショーケースにおいては、除霜運転開始時における主蒸発器１４への冷媒液の供給の遮断に先行して、補助蒸発器１５の予冷運転を行い、除霜運転終了時における主蒸発器１４への冷媒液の供給後も、補助蒸発器１５の保冷運転を行うようにした。このように、補助蒸発器１５の予冷運転を行うと、除霜運転が開始されたときには、補助蒸発器１５は十分に温度が低下しているので、補助蒸発器１５を通過する循環空気を確実に冷却して、吹出口５から適正な温度の冷気を吹出すことができる。また、補助蒸発器１５の保冷運転を行うと、主蒸発器１４の温度が十分に低下するまで、主蒸発器１４を通過した循環空気を補助蒸発器１５で再度冷却して、吹出口５から適正な温度の冷気を吹出すことができる。従って、除霜運転開始後および終了後のしばらくの間、吹出口５から不完全冷気が吹出されるという従来のオープンショーケースの問題を解決することができる。これにより、陳列室３内の温度の安定化を図り、従って陳列された商品の鮮度を維持することができる。 As described above, in the open showcase according to the present invention, the precooling operation of the auxiliary evaporator 15 is performed prior to the interruption of the supply of the refrigerant liquid to the main evaporator 14 at the start of the defrosting operation, and the defrosting is performed. Even after the supply of the refrigerant liquid to the main evaporator 14 at the end of the operation, the auxiliary evaporator 15 is kept cold. Thus, when the precooling operation of the auxiliary evaporator 15 is performed, when the defrosting operation is started, the temperature of the auxiliary evaporator 15 is sufficiently lowered, so that the circulating air passing through the auxiliary evaporator 15 is surely obtained. Then, the cool air at an appropriate temperature can be blown out from the outlet 5. When the auxiliary evaporator 15 is kept cold, the circulating air that has passed through the main evaporator 14 is cooled again by the auxiliary evaporator 15 until the temperature of the main evaporator 14 is sufficiently lowered. Cold air at an appropriate temperature can be blown out. Therefore, the problem of the conventional open showcase that incomplete cold air is blown out from the outlet 5 for a while after the start and end of the defrosting operation can be solved. As a result, the temperature in the display chamber 3 can be stabilized, and thus the freshness of the displayed goods can be maintained.

上記の実施例以外に、流路切換弁３３は第１分岐管路２６と第２分岐管路２７とに分岐される分岐部分に設けたＴポート型の三方弁で構成することができる。熱源３８は除霜ヒーターに替えて、高温高圧の冷媒ガス（ホットガス除霜式）であってもよい。この場合には、圧縮機１２と凝縮器１３との間の冷媒配管１６と、流路切換弁３３と主蒸発器１４との間の第１分岐管路２６を接続する開閉可能なバイパス管路を設け、このバイパス管路を開放することにより、圧縮機１２から送給される高温高圧の冷媒ガスを主蒸発器１４に供給する。除霜運転を行う時間間隔Ｔおよび除霜、予冷、保冷の各運転時間は、上記したものに限られず、主蒸発器１４および補助蒸発器１５のサイズや、設置される店舗の店内環境に応じて適宜変更することができる。本発明は、多段型オープンショーケースに限らず、平型オープンショーケースにも適用できる。また、冷凍機器を構成する圧縮機１２および凝縮器１３が機械室１１の外部に設けられる、冷凍機別置仕様のオープンショーケースにも適用できる。 In addition to the above-described embodiment, the flow path switching valve 33 can be constituted by a T-port type three-way valve provided at a branch portion branched into the first branch pipe line 26 and the second branch pipe line 27. The heat source 38 may be a high-temperature and high-pressure refrigerant gas (hot gas defrosting type) instead of the defrosting heater. In this case, an openable and closable bypass pipe connecting the refrigerant pipe 16 between the compressor 12 and the condenser 13 and the first branch pipe 26 between the flow path switching valve 33 and the main evaporator 14. And by opening the bypass pipe, the high-temperature and high-pressure refrigerant gas fed from the compressor 12 is supplied to the main evaporator 14. The time interval T for performing the defrosting operation and the operating times for defrosting, precooling, and cold insulation are not limited to those described above, depending on the size of the main evaporator 14 and the auxiliary evaporator 15 and the in-store environment of the store to be installed. Can be changed as appropriate. The present invention can be applied not only to a multistage open showcase but also to a flat open showcase. Further, the present invention can also be applied to an open showcase of a refrigerator separate specification in which the compressor 12 and the condenser 13 constituting the refrigeration equipment are provided outside the machine room 11.

４吸込口
５吹出口
６冷気通路
１２圧縮機
１３凝縮器
１４主蒸発器
１５補助蒸発器
１６冷媒配管
２０送風ファン
２９膨張部
３３流路切換弁
３８熱源（除霜ヒーター）
３９着霜センサ
Ｔ時間間隔 4 Suction Port 5 Air Outlet 6 Cold Air Passage 12 Compressor 13 Condenser 14 Main Evaporator 15 Auxiliary Evaporator 16 Refrigerant Pipe 20 Blower Fan 29 Expanding Unit 33 Channel Switching Valve 38 Heat Source (Defrost Heater)
39 Frosting sensor T Time interval

Claims

A main evaporator (14), an auxiliary evaporator (15), and a heat source (38) for heating the main evaporator (14) disposed in the cool air passage (6) extending from the suction port (4) to the outlet (5). ) And a control device (C) for controlling the operating state of these devices,
The auxiliary evaporator (15) is an open showcase disposed in the cold air passage (6) between the main evaporator (14) and the outlet (5),
The control device (C) supplies the refrigerant liquid to the main evaporator (14) and supplies the refrigerant liquid to the auxiliary evaporator (15) in a state where the energization to the heat source (38) is stopped during the steady operation. In the defrosting operation, the supply of the refrigerant liquid to the main evaporator (14) is interrupted while the heat source (38) is energized, and the refrigerant liquid is supplied to the auxiliary evaporator (15). Configured to supply,
The control device (C) starts the pre-cooling operation by supplying the refrigerant liquid to the auxiliary evaporator (15) prior to the interruption of the supply of the refrigerant liquid to the main evaporator (14) at the start of the defrosting operation. The refrigerant liquid is continuously supplied to the auxiliary evaporator (15) until the predetermined time has elapsed from the start of supply of the refrigerant liquid to the main evaporator (14) at the end of the defrosting operation. An open showcase characterized by being constructed.

The control device (C) is configured to perform a defrosting operation for a predetermined time every equal time interval (T) regardless of the presence or absence of frost formation on the main evaporator (14). Open showcase.

The control device (C) confirms that the main evaporator (14) has no frosting in a state where the supply of the refrigerant liquid to both evaporators (14, 15) is cut off every 24 hours. The open showcase according to claim 1 or 2, configured to perform a complete defrosting operation in which energization to the heat source (38) is continued until detection by the frosting sensor (39) disposed in (14).