JPH076718B2 - Refrigeration equipment - Google Patents
Refrigeration equipmentInfo
- Publication number
- JPH076718B2 JPH076718B2 JP20582687A JP20582687A JPH076718B2 JP H076718 B2 JPH076718 B2 JP H076718B2 JP 20582687 A JP20582687 A JP 20582687A JP 20582687 A JP20582687 A JP 20582687A JP H076718 B2 JPH076718 B2 JP H076718B2
- Authority
- JP
- Japan
- Prior art keywords
- evaporator
- temperature
- inlet
- hot gas
- valve
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
Landscapes
- Defrosting Systems (AREA)
- Air Conditioning Control Device (AREA)
- Devices That Are Associated With Refrigeration Equipment (AREA)
Description
【発明の詳細な説明】 (産業上の利用分野) 本発明は、膨張機構に、蒸発器の出入口温度差に基づく
弁開度調節により過熱度制御する電動式膨張弁を用い、
且つ、フロスト時、圧縮機から吐出するホットガスを蒸
発器に導いてデフロストを行うようにした冷凍装置に関
する。DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention uses, as an expansion mechanism, an electric expansion valve that controls a superheat degree by adjusting a valve opening degree based on a difference in inlet and outlet temperatures of an evaporator
In addition, the present invention relates to a refrigerating apparatus that defrosts by introducing hot gas discharged from a compressor to an evaporator during frosting.
(従来の技術) 従来、膨張機構として電動式膨張弁を用い、蒸発器の出
入口温度を温度センサーで検出して、該検出出入口温度
差に基づいて膨張弁の開度調節を行い、所定の過熱度が
得られるようにしたものは、例えば特開昭61−36671号
公報等により知られている。(Prior Art) Conventionally, an electric expansion valve is used as an expansion mechanism, a temperature sensor detects the inlet / outlet temperature of the evaporator, and the opening degree of the expansion valve is adjusted based on the detected inlet / outlet temperature difference to prevent a predetermined overheat. A device capable of obtaining a degree is known, for example, from JP-A-61-36671.
又、圧縮機の吐出側から蒸発器の入口側にホットガスバ
イパス路を設けて、該バイパス路を介して導入するホッ
トガスの保有熱量を利用して、蒸発器のデフロストを行
うようにしたものは、例えば特開昭59−122863号公報等
により知られている。Further, a hot gas bypass passage is provided from the discharge side of the compressor to the inlet side of the evaporator, and the heat quantity of the hot gas introduced through the bypass passage is used to defrost the evaporator. Are known, for example, from Japanese Patent Application Laid-Open No. 59-122863.
そして、膨張機構に電動式膨張弁を用い、ホットガスバ
イパス方式によりデフロストを行うようにしたものにあ
っては、デフロストの完了後には、ホットガスの注入側
となる蒸発器の入口温度が、通常の冷却運転の場合の出
口温度よりも低い状態から出口温度よりも高い状態に逆
転してしまうことになるため、もはや出入口温度差に基
づく過熱度制御は行えなくなり、従って、一般には、該
膨張弁の弁開度を、運転再開当初の一定時間(例えば30
秒)にわたり、例えば75%程度の一定開度に強制的に固
定して、運転再開に伴う過渡的な対応を図るようにして
いる。Then, in the one in which the electric expansion valve is used for the expansion mechanism and the defrosting is performed by the hot gas bypass system, after the defrosting is completed, the inlet temperature of the evaporator on the hot gas injection side is usually In the case of the cooling operation of the above, since it will reverse from the state lower than the outlet temperature to the state higher than the outlet temperature, superheat control based on the inlet / outlet temperature difference can no longer be performed, and therefore, in general, the expansion valve The valve opening of the
For a second), it is forcibly fixed to a fixed opening of, for example, about 75%, so that a transient response can be made when the operation is restarted.
(発明が解決しようとする問題点) ところが、デフロスト完了後の運転再開時、前記電動式
膨張弁の弁開度を一定時間にわたり一定開度に固定する
ようにしても、外気条件によっては、下記の問題が起こ
るのであった。(Problems to be Solved by the Invention) However, even when the valve opening degree of the electric expansion valve is fixed to a constant opening degree for a certain period of time when the operation is restarted after the completion of defrosting, depending on the outside air condition, The problem of.
即ち、低外気時には、凝縮器での凝縮作用が促進されて
所定の冷凍能力を良好に引出せることから、蒸発器の出
入口温度は、比較的速やかに庫内設定温度に応じた低温
度状態へと低下するものであるが、それにも拘わらず、
固定弁開度(75%)が、この低外気時における比較的小
さい熱負荷に対して広過ぎるか、又は、弁開度固定時間
(30秒)が、蒸発器の温度低下時間に比べて長過ぎる
と、前記蒸発器の温度低下に伴ってやがては該蒸発器で
の冷媒の気化が十分なされなくなり、圧縮機に液冷媒が
返送されてしまうという液バックが起こるのであった。That is, when the outside air is low, the condensing action in the condenser is promoted and the predetermined refrigerating capacity can be satisfactorily drawn out, so the inlet / outlet temperature of the evaporator is relatively quickly brought to the low temperature state corresponding to the set temperature in the refrigerator. However, despite that,
The fixed valve opening (75%) is too wide for this relatively small heat load at low outside air, or the valve opening fixed time (30 seconds) is longer than the temperature decrease time of the evaporator. After that, with the temperature decrease of the evaporator, the vaporization of the refrigerant in the evaporator is not sufficiently performed, and the liquid refrigerant occurs in which the liquid refrigerant is returned to the compressor.
一方、高外気時には、冷凍能力のダウンにより蒸発器の
温度低下が遅いにも拘わらず、一定時間内にわたり固定
される固定弁開度が十分広くないか、又は、弁開度固定
時間が短いと、未だ十分に蒸発器が冷えていない状態で
通常の過熱度制御に移行されることになり、早々に弁開
度が絞られて、蒸発器への供給冷媒量が減少し、庫内を
設定温度まで温度低下させるプルダウン時間が長引いて
しまうのであった。On the other hand, when the outside air is high, the fixed valve opening fixed for a fixed time is not wide enough or the valve opening fixed time is short, even though the temperature of the evaporator slows down due to the reduction of the refrigerating capacity. If the evaporator is not sufficiently cooled, it will be shifted to normal superheat control, the valve opening will be throttled immediately, the amount of refrigerant supplied to the evaporator will decrease, and the inside of the refrigerator will be set. The pull-down time for lowering the temperature to temperature was prolonged.
上記問題は、海上コンテナ等に装載される冷凍装置にあ
っては一層顕著となるのであって、昼と夜あるいは地域
により外気温度が大きく変動してしまうため、画一的な
弁開度及び画一的な弁開度固定時間では外気条件にマッ
チした適切な運転再開が行いがたいのであった。The above problem becomes more remarkable in a refrigeration system mounted on a sea container or the like, and since the outside air temperature fluctuates greatly depending on the day and night or the area, a uniform valve opening and It was difficult to properly restart the operation that matched the outside air conditions with a fixed valve opening time.
本発明の目的は、デフロスト後の運転再開時における膨
張弁の弁開度調節の仕方と、通常の過熱度制御に移行さ
せるための条件とを工夫することにより、外気条件いか
んに拘わらず、液バックを回避できると共に、プルダウ
ン時間の短縮化を図り得る冷凍装置を提供する点にあ
る。The object of the present invention is to improve the liquid opening regardless of the outside air condition by devising a method for adjusting the valve opening degree of the expansion valve at the time of restarting operation after defrosting and a condition for shifting to normal superheat control. Another object of the present invention is to provide a refrigeration system capable of avoiding backing and shortening the pull-down time.
(問題点を解決するための手段) そこで本発明は、圧縮機(1)と凝縮器(2)と蒸発器
(5)及び該蒸発器(5)の出入口温度差に基づく弁開
度調節により過熱度制御する電動式膨張弁(4)とを備
え、前記圧縮機(1)から吐出するホットガスを前記凝
縮器(2)を側路して前記蒸発器(5)に導くホットガ
スバイパス路(8)と、該バイパス路(8)にホットガ
スをバイパスさせるホットガス弁(7)とを設けて、前
記蒸発器(5)のフロスト時、前記バイパス路(8)を
介して導入するホットガスにより前記蒸発器(5)のデ
フロストを行うようにした冷凍装置であって、デフロス
ト開始直前における前記蒸発器(5)の入口温度を記憶
する記憶手段と、デフロスト完了後の運転再開時、前記
膨張弁(4)の弁開度を、前記蒸発器(5)の検出出口
温度と、前記記憶手段に記憶した記憶入口温度との差に
基づいて疑似過熱度制御し、かつ、前記検出出口温度又
は検出入口温度が前記記憶入口温度近くに達した後、前
記膨張弁(4)の弁開度調節を前記蒸発器(5)の出入
口温度差に基づく過熱度制御に移行させる弁開度制御手
段とを備えていることを特徴とするものである。(Means for Solving Problems) Therefore, according to the present invention, a compressor (1), a condenser (2), an evaporator (5), and a valve opening adjustment based on a difference in inlet and outlet temperatures of the evaporator (5) are provided. An electric expansion valve (4) for controlling the degree of superheat, and a hot gas bypass passage for guiding hot gas discharged from the compressor (1) to the evaporator (5) by-passing the condenser (2). (8) and a hot gas valve (7) for bypassing hot gas in the bypass passage (8) are provided to introduce hot gas through the bypass passage (8) during frosting of the evaporator (5). A refrigerating apparatus for defrosting the evaporator (5) by gas, comprising a storage means for storing the inlet temperature of the evaporator (5) immediately before the start of defrosting, and a restarting operation after completion of defrosting. The valve opening of the expansion valve (4) is set to the evaporator ( After performing pseudo-superheat control based on the difference between the detected outlet temperature of 5) and the stored inlet temperature stored in the storage means, and after the detected outlet temperature or the detected inlet temperature reaches near the stored inlet temperature, A valve opening control means for shifting the valve opening adjustment of the expansion valve (4) to superheat control based on the inlet / outlet temperature difference of the evaporator (5).
(作用) デフロスト完了後には、ホットガスの注入側となる蒸発
器(5)の入口側の温度が、出口温度よりも高くなる
が、記憶手段に記憶するデフロスト開始直前の入口温度
は、庫内設定温度に応じた冷却運転時の低温値であっ
て、その温度差に基づく疑似過熱度制御により、膨張弁
(4)の弁開度は調節されることになる。(Operation) After the defrosting is completed, the temperature on the inlet side of the evaporator (5) on the hot gas injection side becomes higher than the outlet temperature, but the inlet temperature immediately before the start of defrost stored in the storage means is The valve opening degree of the expansion valve (4) is adjusted by the pseudo superheat control based on the temperature difference during the cooling operation according to the set temperature and the temperature difference.
この場合、疑似過熱度制御を行うための前記温度差は、
デフロスト完了直後に最も大きく、蒸発器(5)が高温
状態にある時に、膨張弁(4)の弁開度が最も広開度に
調節されて、前記蒸発器(5)に多量の冷媒を供給し、
その温度低下を促進できるのであり、又、時間経過に伴
って前記蒸発器(5)が温度低下してくると、検出出口
温度もそれに応じて低下していき、前記温度差が小さく
なると、弁開度は徐々に狭く制御されてきて、前記蒸発
器(5)への供給冷媒量が減少され、これにより、液バ
ックを回避し得るのである。In this case, the temperature difference for performing the pseudo superheat control is
Immediately after the completion of defrost, when the evaporator (5) is in a high temperature state, the valve opening of the expansion valve (4) is adjusted to the widest opening to supply a large amount of refrigerant to the evaporator (5). Then
The temperature decrease can be promoted, and when the temperature of the evaporator (5) decreases with the lapse of time, the detection outlet temperature also decreases accordingly, and when the temperature difference decreases, the valve The opening degree is gradually controlled to be narrow, and the amount of refrigerant supplied to the evaporator (5) is reduced, whereby liquid back can be avoided.
そして、検出出口温度又は検出入口温度が記憶入口温度
近くにまで低下し、前記温度差が通常の過熱度制御を行
い得る範囲まで低下すると、通常の過熱度制御に移行さ
れるのであって、該通常の過熱度制御への移行は、外気
温度いかんに拘わらず、蒸発器(5)の検出出口温度又
は検出出口温度と、デフロスト直前における前記記憶入
口温度つまりは庫内設定温度に応じて定められる冷却運
転時の入口温度との比較に基づいて行われるものであ
り、しかも、前記蒸発器(5)はすでに十分に温度低下
しているため、通常の過熱度制御に移行されても、すぐ
に庫内設定温度に応じた所定の低温状態にまで到達で
き、プルダウン時間の遅延も無くし得るものである。Then, when the detected outlet temperature or the detected inlet temperature is reduced to near the stored inlet temperature, and the temperature difference is reduced to a range in which the normal superheat degree control can be performed, the normal superheat degree control is performed. Regardless of the outside air temperature, the transition to the normal superheat degree control is determined according to the detection outlet temperature or the detection outlet temperature of the evaporator (5) and the storage inlet temperature immediately before defrosting, that is, the set temperature inside the refrigerator. This is performed based on the comparison with the inlet temperature during the cooling operation, and since the temperature of the evaporator (5) has already dropped sufficiently, even if the normal superheat control is performed, immediately. It is possible to reach a predetermined low temperature state according to the set temperature in the refrigerator and eliminate the delay of pull-down time.
(実施例) 第1図に示すものは例えば海上コンテナ等に装載される
冷凍装置であり、圧縮機(1)の吐出ガス管(11)側か
ら、ファン(F2)を付設する凝縮器(2)、受液器
(3)、電動式膨張弁(4)、ファン(F)を付設する
蒸発器(5)、アキュムレータ(6)を順次冷媒配管
(10)を介して接続すると共に、前記吐出ガス管(11)
と蒸発器(5)の入口に介装する分流器(45)との間
に、ホットガス弁(7)を介して圧縮機(1)から吐出
されるホットガスを凝縮器(2)及び膨張弁(4)を側
路して蒸発器(5)に導くホットガスバイパス路(8)
を設けたものである。(Embodiment) FIG. 1 shows a refrigerating apparatus mounted on, for example, a marine container, and a condenser (a fan (F2) is attached from the discharge gas pipe (11) side of the compressor (1) ( 2), a liquid receiver (3), an electric expansion valve (4), an evaporator (5) with a fan (F) attached, and an accumulator (6) are sequentially connected through a refrigerant pipe (10), and Discharge gas pipe (11)
The hot gas discharged from the compressor (1) via the hot gas valve (7) between the condenser and the flow divider (45) installed at the inlet of the evaporator (5) and the condenser (2) and expansion. Hot gas bypass passage (8) which leads the evaporator (5) by bypassing the valve (4)
Is provided.
前記電動式膨張弁(4)は、弁開度を駆動調節する弁駆
動部(40M)を備え、前記蒸発器(5)の入口管(51)
及び出口管(52)にそれぞれ付設する入口温度センサー
(41)及び出口温度センサー(42)により、前記蒸発器
(5)の出入口温度を検出して、該検出出入口温度差に
基づいて弁開度を調節し、適性過熱度を得るようにして
いる。The electric expansion valve (4) includes a valve drive section (40M) for driving and adjusting a valve opening degree, and the inlet pipe (51) of the evaporator (5).
The inlet and outlet temperatures of the evaporator (5) are detected by an inlet temperature sensor (41) and an outlet temperature sensor (42) attached to the outlet pipe (52) and the valve opening degree based on the detected inlet and outlet temperature difference. Is adjusted to obtain an appropriate degree of superheat.
又、前記ホットガス弁(7)は、前記バイパス路(8)
に対する弁開度を0%〜100%に制御可能とした電動式
三方比例弁を用い、その電動部(20M)の駆動により、
前記蒸発器(5)へのホットガスのバイパス量を調節す
ると共に、前記蒸発器(5)のフロスト時、前記ホット
ガス弁(7)をバイパス路(8)に対して100%開い
て、循環するホットガスの全量を前記蒸発器(5)に導
入し、該ホットガスによりデフロストを行うようにして
いる。The hot gas valve (7) is connected to the bypass passage (8).
Using an electric three-way proportional valve that can control the valve opening to 0% to 100% by driving its electric part (20M),
The hot gas bypass amount to the evaporator (5) is adjusted, and when the evaporator (5) is frosted, the hot gas valve (7) is opened 100% to the bypass passage (8) to circulate. The entire amount of the hot gas used is introduced into the evaporator (5), and the hot gas is used for defrosting.
以上の構成において、デフロスト完了後の運転再開時、
外気温度いかんに拘わらず適正な運転再開が図れるよ
う、デフロスト開始直前における前記蒸発器(5)の入
口温度を記憶する記憶手段と、デフロスト完了後の運転
再開時、前記膨張弁(4)の弁開度を、前記蒸発器
(5)の検出出口温度と、前記記憶手段に記憶した記憶
入口温度との差に基づいて疑似過熱度制御し、かつ、前
記検出出口温度又は検出入口温度が前記記憶入口温度近
くに達した後、前記膨張弁(4)の弁開度調節を前記蒸
発器(5)の出入口温度差に基づく過熱度制御に移行さ
せる弁開度制御手段とを形成して、第2図に示すコント
ローラ(100)内に具備させるのである。With the above configuration, when the operation is restarted after the completion of defrost,
A storage means for storing the inlet temperature of the evaporator (5) immediately before the start of defrosting and a valve of the expansion valve (4) at the time of restarting operation after the completion of defrosting so that the operation can be properly restarted regardless of the outside air temperature. The opening degree is pseudo-superheated on the basis of the difference between the detected outlet temperature of the evaporator (5) and the stored inlet temperature stored in the storage means, and the detected outlet temperature or the detected inlet temperature is stored in the memory. Valve opening control means for shifting the valve opening adjustment of the expansion valve (4) to superheat control based on the inlet / outlet temperature difference of the evaporator (5) after reaching the temperature near the inlet, It is provided in the controller (100) shown in FIG.
前記コントローラ(100)は、マイクロコンピュータ等
を用いて構成するものであり、その入力側には、デフロ
スト開始指令を取込むために、前記蒸発器(5)を通過
する空気の出入口圧力差に基づき作動するエアプレッシ
ャスイッチ(APS)並びに、例えば12時間をセット時間
とするデフロストタイマスイッチ(2D)及びマニュアル
操作によりデフロストを行う手動デフロストスイッチ
(3D)を接続すると共に、デフロストの完了検知を行う
ために、前記出口管(52)の温度を検出するサーミスタ
(Th)を接続する。又、前記蒸発器(5)の吸込及び吹
出空気温度を検出するリターン及びサプライセンサー
(RS)(SS)と、庫内温度を設定する温度設定器(55)
とを接続すると共に、前記蒸発器(5)の入口及び出口
温度を検出する温度センサー(41)(42)、並びに、外
気温度を検出する外気温度検出器(60)を接続する。The controller (100) is configured by using a microcomputer or the like, and its input side is based on the inlet / outlet pressure difference of the air passing through the evaporator (5) in order to receive a defrost start command. In order to connect the operating air pressure switch (APS), the defrost timer switch (2D) with a set time of 12 hours, and the manual defrost switch (3D) that performs defrost by manual operation, and to detect the completion of defrost , A thermistor (Th) for detecting the temperature of the outlet pipe (52) is connected. Further, a return and supply sensor (RS) (SS) for detecting the temperature of intake and blown air of the evaporator (5), and a temperature setter (55) for setting the temperature inside the refrigerator.
The temperature sensors (41) (42) for detecting the inlet and outlet temperatures of the evaporator (5) and the outside air temperature detector (60) for detecting the outside air temperature are connected.
一方、出力側には、圧縮機(1)のモータ(MC)を発停
する電磁継電器(88C)、蒸発器側ファン(F)のモー
タ(MF)を発停する電磁継電器(88F)並びに該モータ
(MF)を極数変更等により回転数を変化させて蒸発器
(5)の通過空気を高風量と低風量とに切換える電磁継
電器(88FH)、凝縮器側ファン(F2)のモータ(MF2)
を発停する電磁継電器(88F2)、ホットガス弁(7)の
電動部(20M)、電動式膨張弁(4)の弁駆動部(40M)
を接続する。尚、前記継電器(88C)(88F)の励磁回路
には、吐出ガス管(11)に介装する高圧圧力検出器(HP
S)並びに、圧縮機モータ(MC)の過電流リレーの接点
(51C)及びサーモスイッチ(49C)を直列に介装してお
り、更に、ファン用の前記継電器(88F)には、そのフ
ァンモータ(MF)のサーモスイッチ(49CF)を直列に継
続している。On the other hand, on the output side, an electromagnetic relay (88C) that starts and stops the motor (MC) of the compressor (1), an electromagnetic relay (88F) that starts and stops the motor (MF) of the evaporator side fan (F), and the electromagnetic relay (88F). Electromagnetic relay (88FH), which changes the rotation speed of the motor (MF) by changing the number of poles, etc., to switch the air passing through the evaporator (5) between high air volume and low air volume, motor (MF2) of the condenser side fan (F2) )
Relay (88F2) for starting and stopping, electric part (20M) of hot gas valve (7), valve drive part (40M) of electric expansion valve (4)
Connect. In addition, in the exciting circuit of the relays (88C) (88F), a high pressure pressure detector (HP
S), the contact (51C) and the thermoswitch (49C) of the overcurrent relay of the compressor motor (MC) are connected in series, and further, the fan motor is connected to the fan relay (88F). The (MF) thermoswitch (49CF) continues in series.
そして、前記温度設定器(55)で設定される庫内設定温
度(SP)に基づいて−5℃〜−6℃以下のフローズン領
域からそれよりも高いチルド領域にわたる所定の冷却運
転が行われるのであり、この冷却運転時、前記蒸発器
(5)がフロストして、その通過空気の圧力変化により
前記エアプレッシャスイッチ(APS)は自動的に作動し
たり、又は、前記デフロストタイマスイッチ(2D)によ
り規定時間毎にデフロスト指令が出されたり、あるいは
デフロストスイッチ(3D)が手動操作されると、デフロ
スト運転へ移行されるのである。Then, the predetermined cooling operation is performed from the frozen region of -5 ° C to -6 ° C or less to the chilled region higher than that based on the internal temperature setting (SP) set by the temperature setting device (55). Yes, during this cooling operation, the evaporator (5) is frosted, and the air pressure switch (APS) is automatically actuated by the pressure change of the passing air, or the defrost timer switch (2D) is used. When a defrost command is issued or the defrost switch (3D) is manually operated at regular time intervals, the defrost operation is performed.
こうして、デフロストの開始指令が入ると、第3図に示
すフローチャートに従って処理が行われるのであって、
まず、前記入口温度センサー(41)で検出されるデフロ
スト開始直線における前記蒸発器(5)の入口温度(TR
I)を、前記コントローラ(100)内のメモリーに記憶
し、その後、前記ホットガス弁(7)の電動部(20M)
を駆動して、高圧ガス管(11)をバイパス路(8)に対
して100%開き、循環するホットガスの全量を蒸発器
(5)にバイパスさせてデフロスト運転を行うのであ
る。In this way, when the defrost start command is input, the processing is performed according to the flowchart shown in FIG.
First, the inlet temperature (TR) of the evaporator (5) on the defrost start line detected by the inlet temperature sensor (41)
I) is stored in the memory in the controller (100), and then the electric part (20M) of the hot gas valve (7) is stored.
Is driven to open the high pressure gas pipe (11) 100% to the bypass passage (8), and the entire amount of circulating hot gas is bypassed to the evaporator (5) to perform the defrost operation.
こうして、前記蒸発器(5)は、ホットガスの保有熱量
によりデフロストされるのであり、デフロストが進行し
てきて、出口管(52)が加熱され、サーミスタ(Th)が
所定温度に達したことを検出すると該デフロスト運転は
完了されるのである。In this way, the evaporator (5) is defrosted by the heat quantity of the hot gas, and it is detected that the defrosting has progressed, the outlet pipe (52) has been heated, and the thermistor (Th) has reached a predetermined temperature. Then, the defrost operation is completed.
そして、このデフロスト完了後の運転再開時は、前記出
口温度センサー(42)により、蒸発器(5)の出口温度
を検出して、この検出出口温度(TRO)と、前記記憶手
段に記憶しておいたデフロスト開始直前の記憶入口温度
(TRI)との差(TRO−TRI)が、通常の過熱度制御を行
い得る所定の過熱度(α)、例えば4℃〜5℃の範囲内
に入るまでの間、前記温度差に基づいて、前記膨張弁
(4)の弁開度を、疑似過熱度制御するのである。When the operation is restarted after the completion of defrosting, the outlet temperature sensor (42) detects the outlet temperature of the evaporator (5) and stores the detected outlet temperature (TRO) in the storage means. Until the difference (TRO-TRI) with the memory inlet temperature (TRI) immediately before the start of Oita defrost falls within a predetermined superheat degree (α) that allows normal superheat control, for example, within the range of 4 ° C to 5 ° C. During this period, the valve opening degree of the expansion valve (4) is pseudo-superheat controlled based on the temperature difference.
これにより、デフロスト完了後においては、ホットガス
の注入側となる前記蒸発器(5)の入口側の温度が、出
口温度よりも高くなるという逆転現象が起こることにな
るが、記憶手段に記憶しておいたデフロスト開始直前の
入口温度(TRI)は、検出出口温度(TRO)よりも低い通
常冷却運転時の低温値であるために、その差(TRO−TR
I)に基づく疑似的な過熱度制御が可能となって、前記
膨張弁(4)の弁開度が調節されるのである。As a result, after the defrosting is completed, a reversal phenomenon occurs in which the temperature of the inlet side of the evaporator (5) on the hot gas injection side becomes higher than the outlet temperature, but this is stored in the storage means. The inlet temperature (TRI) just before the start of defrost is a low temperature value during normal cooling operation, which is lower than the detected outlet temperature (TRO), so the difference (TRO-TR
The pseudo superheat control based on I) becomes possible, and the valve opening of the expansion valve (4) is adjusted.
しかも、疑似過熱度制御を行うための前記温度差(TRO
−TRI)は、第4図に示すように、デフロスト完了直後
に最も大きく、前記蒸発器(5)が高温状態にある時
に、膨張弁(4)の弁開度が最も広開度に調節されて、
前記蒸発器(5)に多量の冷媒を供給し、その温度低下
を促進できるのであり、又、時間経過に伴って前記蒸発
器(5)が温度低下してくると、検出出口温度(TRO)
もそれに応じて温度低下していき、その温度差(TRO−T
RI)が小さくなると、弁開度は徐々に狭く制御されてき
て、前記蒸発器(5)への供給冷媒量が減少され、これ
により、液バックを回避し得るのである。Moreover, the temperature difference (TRO
-TRI) is the largest as shown in FIG. 4 immediately after the completion of defrosting, and the valve opening of the expansion valve (4) is adjusted to the widest opening when the evaporator (5) is in a high temperature state. hand,
A large amount of refrigerant can be supplied to the evaporator (5) to accelerate the temperature decrease, and when the temperature of the evaporator (5) decreases with time, the detection outlet temperature (TRO)
Also decreases accordingly, and the temperature difference (TRO-T
When RI) becomes smaller, the valve opening is controlled to be gradually narrowed and the amount of refrigerant supplied to the evaporator (5) is reduced, whereby liquid back can be avoided.
そして、検出出口温度(TRO)が記憶入口温度(TRI)近
くにまで低下し、その温度差(TRO−TRI=α)が4℃〜
5℃となると、通常の過熱度制御に移行されるのであっ
て、該過熱度制御への移行は、外気温度いかんに拘わら
ず、蒸発器(5)の検出出口温度(TRO)と、デフロス
ト直前における前記記憶入口温度(TRI)つまりは庫内
設定温度(SP)に応じて定められる冷却運転時の入口温
度との比較に基づいて行われるものであり、しかも、前
記蒸発器(5)はすでに庫内設定温度(SP)に応じた低
温状態となっているため、通常の過熱度制御に移行され
ても、すぐに庫内設定温度(SP)に応じた所定の温度
(おおむね庫内設定温度(SP)に対し5℃程度低い温
度)にまで到達できるのである。Then, the detection outlet temperature (TRO) decreases to near the memory inlet temperature (TRI), and the temperature difference (TRO-TRI = α) is 4 ° C ~
When the temperature reaches 5 ° C., the control is transferred to the normal superheat control, and the control is transferred to the detection outlet temperature (TRO) of the evaporator (5) and immediately before the defrost regardless of the outside air temperature. The stored inlet temperature (TRI), that is, the inlet temperature at the time of the cooling operation determined according to the set temperature (SP) in the refrigerator, and the evaporator (5) is already used. Since it is in a low temperature state that corresponds to the set temperature (SP) in the refrigerator, even if the control is switched to normal superheat control, the predetermined temperature (roughly the set temperature in the refrigerator) that corresponds to the set temperature (SP) in the refrigerator is immediately reached. (A temperature about 5 ° C lower than SP)).
従って、弁開度及び弁固定時間が画一的なものゝよう
に、液バックや、プルダウン時間の遅延といった問題を
無くし得て、外気温度いかんに拘わらず適切な運転再開
が行えるのである。Therefore, as in the case where the valve opening and the valve fixing time are uniform, it is possible to eliminate problems such as liquid backing and delay of pull-down time, and it is possible to appropriately restart the operation regardless of the outside air temperature.
尚、通常の過熱度制御に移行された後には、庫内設定温
度(SP)に基づいて、チルド又はフローズン領域での冷
却運転が行われるものであるが、チルド領域の運転で
は、前記電動部(20M)を、庫内設定温度(SP)とリタ
ーンセンサー(RS)との比較に基づいて所謂PID制御
し,熱負荷にマッチした所定量のホットガスをバイパス
させると共に、電磁継電器(88FH)をオンにして、蒸発
器(5)の通過風量を高風量とし、庫内空気の循環を良
くしている。又、フローズン領域の運転では、ホットガ
スのバイパスは行わずに、庫内設定温度(SP)とリター
ン又はサプライセンサー(RS又はSS)との比較に基づい
て圧縮機(1)の発停制御を行うと共に、電磁継電器
(88FH)をオフにして、蒸発器(5)の通過風量を低風
量にしている。After shifting to the normal superheat control, the cooling operation in the chilled or frozen region is performed based on the internal set temperature (SP). (20M) is so-called PID control based on the comparison between the set temperature (SP) and the return sensor (RS), bypasses a certain amount of hot gas that matches the heat load, and the electromagnetic relay (88FH) When turned on, the amount of air passing through the evaporator (5) is set to a high amount to improve the circulation of air in the refrigerator. Also, in the operation in the frozen region, hot gas bypass is not performed, and the start / stop control of the compressor (1) is performed based on the comparison between the internal set temperature (SP) and the return or supply sensor (RS or SS). At the same time, the electromagnetic relay (88FH) is turned off to reduce the amount of air passing through the evaporator (5).
以上説明した実施例では、通常の過熱度制御への移行条
件、すなわち、疑似過熱度制御の解除条件を、検出出口
温度(TRO)と記憶入口温度(TRI)との差が所定温度範
囲(α)に入った時としたが、前記入口温度センサー
(41)で検出する検出入口温度(TRI')と記憶入口温度
(TRI)との差が所定温度範囲(α)に入った時として
もよい。In the embodiment described above, the difference between the detected outlet temperature (TRO) and the memory inlet temperature (TRI) is set to the predetermined temperature range (α ), But the difference between the detected inlet temperature (TRI ') detected by the inlet temperature sensor (41) and the stored inlet temperature (TRI) may be within the predetermined temperature range (α). .
(発明の効果) 以上のように本発明では、デフロスト開始直前における
蒸発器(5)の入口温度を記憶し、デフロスト完了後の
運転再開時、電動式膨張弁(4)の弁開度を、前記蒸発
器(5)の検出出口温度と、記憶した記憶入口温度との
差に基づいて疑似過熱度制御し、かつ、前記検出出口温
度又は検出入口温度が前記記憶入口温度近くに達した
後、前記膨張弁(4)の弁開度調節を前記蒸発器(5)
の出入口温度差に基づく過熱度制御に移行させるように
したから、液バックやプルダウン時間の遅延といった問
題を回避でき、外気温度いかんに拘わらず適切な運転再
開が行えるのである。(Effect of the invention) As described above, in the present invention, the inlet temperature of the evaporator (5) immediately before the start of defrosting is stored, and when the operation is restarted after the completion of defrosting, the valve opening degree of the electric expansion valve (4) is set as follows. After performing pseudo-superheat control based on the difference between the detected outlet temperature of the evaporator (5) and the stored stored inlet temperature, and after the detected outlet temperature or the detected inlet temperature reaches near the stored inlet temperature, The opening degree of the expansion valve (4) is adjusted by adjusting the evaporator (5).
Since the control is shifted to the superheat degree control based on the inlet / outlet temperature difference, the problems such as liquid backing and delay of pull-down time can be avoided, and proper operation can be restarted regardless of the outside air temperature.
第1図は本発明に係る冷凍装置の冷媒配管系統図、第2
図は同制御回路図、第3図はデフロスト完了後の運転再
開時における制御手順を示すフローチャート図、第4図
は蒸発器の入口及び出口温度の変化を示す図である。 (1)……圧縮機 (2)……凝縮器 (4)……電動式膨張弁 (5)……蒸発器 (7)……ホットガス弁 (8)……ホットガスバイパス路FIG. 1 is a refrigerant piping system diagram of a refrigerating apparatus according to the present invention, and FIG.
The figure is the same control circuit diagram, FIG. 3 is a flow chart showing the control procedure at the time of restarting the operation after completion of defrosting, and FIG. 4 is a diagram showing changes in the inlet and outlet temperatures of the evaporator. (1) ...... Compressor (2) ...... Condenser (4) ...... Motorized expansion valve (5) ...... Evaporator (7) ...... Hot gas valve (8) ...... Hot gas bypass passage
Claims (1)
(5)及び該蒸発器(5)の出入口温度差に基づく弁開
度調節により過熱度制御する電動式膨張弁(4)とを備
え、前記圧縮機(1)から吐出するホットガスを前記凝
縮器(2)を側路して前記蒸発器(5)に導くホットガ
スバイパス路(8)と、該バイパス路(8)にホットガ
スをバイパスさせるホットガス弁(7)とを設けて、前
記蒸発器(5)のフロスト時、前記バイパス路(8)を
介して導入するホットガスにより前記蒸発器(5)のデ
フロストを行うようにした冷凍装置であって、デフロス
ト開始直前における前記蒸発器(5)の入口温度を記憶
する記憶手段と、デフロスト完了後の運転再開時、前記
膨張弁(4)の弁開度を、前記蒸発器(5)の検出出口
温度と、前記記憶手段に記憶した記憶入口温度との差に
基づいて疑似過熱度制御し、かつ、前記検出出口温度又
は検出入口温度が前記記憶入口温度近くに達した後、前
記膨張弁(4)の弁開度調節を前記蒸発器(5)の出入
口温度差に基づく過熱度制御に移行させる弁開度制御手
段とを備えていることを特徴とする冷凍装置。1. A motor-operated expansion valve (4) for controlling a superheat by controlling a valve opening of a compressor (1), a condenser (2), an evaporator (5) and a temperature difference between an inlet and an outlet of the evaporator (5). ) And a hot gas bypass passage (8) for guiding hot gas discharged from the compressor (1) to the evaporator (5) by-passing the condenser (2), and the bypass passage (8). ) Is provided with a hot gas valve (7) for bypassing hot gas, and when the evaporator (5) is frosted, hot gas introduced through the bypass passage (8) is used to defrost the evaporator (5). In the refrigerating apparatus, the storage means for storing the inlet temperature of the evaporator (5) immediately before the start of defrost, and the valve opening degree of the expansion valve (4) at the time of restarting the operation after the completion of defrost. A detection outlet temperature of the evaporator (5) and the storage means Pseudo-superheat control is performed based on the difference from the stored stored inlet temperature, and the valve opening adjustment of the expansion valve (4) is performed after the detected outlet temperature or the detected inlet temperature reaches near the stored inlet temperature. A refrigerating apparatus comprising: a valve opening control unit that shifts to superheat control based on a difference in inlet and outlet temperatures of the evaporator (5).
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP20582687A JPH076718B2 (en) | 1987-08-19 | 1987-08-19 | Refrigeration equipment |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP20582687A JPH076718B2 (en) | 1987-08-19 | 1987-08-19 | Refrigeration equipment |
Publications (2)
Publication Number | Publication Date |
---|---|
JPS6449869A JPS6449869A (en) | 1989-02-27 |
JPH076718B2 true JPH076718B2 (en) | 1995-01-30 |
Family
ID=16513348
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP20582687A Expired - Lifetime JPH076718B2 (en) | 1987-08-19 | 1987-08-19 | Refrigeration equipment |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPH076718B2 (en) |
Families Citing this family (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2607262Y2 (en) * | 1992-06-01 | 2001-05-28 | 新晃工業株式会社 | Control device for heat exchanger for air conditioning |
CN111271809A (en) * | 2019-12-20 | 2020-06-12 | 宁波奥克斯电气股份有限公司 | Control method and device, air conditioner and computer readable storage medium |
-
1987
- 1987-08-19 JP JP20582687A patent/JPH076718B2/en not_active Expired - Lifetime
Also Published As
Publication number | Publication date |
---|---|
JPS6449869A (en) | 1989-02-27 |
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