JPS622675B2 - - Google Patents
Info
- Publication number
- JPS622675B2 JPS622675B2 JP55137113A JP13711380A JPS622675B2 JP S622675 B2 JPS622675 B2 JP S622675B2 JP 55137113 A JP55137113 A JP 55137113A JP 13711380 A JP13711380 A JP 13711380A JP S622675 B2 JPS622675 B2 JP S622675B2
- Authority
- JP
- Japan
- Prior art keywords
- temperature
- refrigerator
- refrigeration
- evaporator
- compressor
- 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
Links
- 238000005057 refrigeration Methods 0.000 claims description 47
- 239000003507 refrigerant Substances 0.000 claims description 37
- 239000007788 liquid Substances 0.000 claims description 13
- 230000007423 decrease Effects 0.000 description 32
- 238000010586 diagram Methods 0.000 description 5
- 238000000034 method Methods 0.000 description 5
- 230000008020 evaporation Effects 0.000 description 4
- 238000001704 evaporation Methods 0.000 description 4
- 238000001514 detection method Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 238000013459 approach Methods 0.000 description 1
- 230000005494 condensation Effects 0.000 description 1
- 238000009833 condensation Methods 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 238000006073 displacement reaction Methods 0.000 description 1
- 235000013399 edible fruits Nutrition 0.000 description 1
- 238000007710 freezing Methods 0.000 description 1
- 230000008014 freezing Effects 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 235000013372 meat Nutrition 0.000 description 1
- 235000013311 vegetables Nutrition 0.000 description 1
- 239000002699 waste material Substances 0.000 description 1
Landscapes
- Devices That Are Associated With Refrigeration Equipment (AREA)
Description
本発明は、冷凍装置に関する。
例えば、コンテナ用冷凍装置は、コンテナ庫内
の温度を−５℃〜−６℃以下、通常は−18℃に制
御する冷凍運転と、−５℃〜−６℃以上、通常は
０℃〜５℃に制御し、積荷を氷結せずに保存する
冷蔵運転が行なわれるものであつて、本発明は以
上の如く行なう各運転のうち、特に冷蔵運転にお
ける従来装置の問題を解決しようとするものであ
る。
即ち、コンテナ用冷凍装置は、通常前記した冷
凍運転時における所要冷凍能力を基準に設計され
ており、多くは、外気温度38℃で庫内温度が−18
℃に保持できる冷凍能力（約2500Kcal／ｈ）に
設計されている。従つて、冷蔵運転においては、
蒸発温度が高くなるため約２〜３倍の冷凍能力で
運転されることになり、そのため、冷蔵運転時に
おける庫内温度の制御が粗になり、場合によつて
は、肉、野菜、果物等の積荷が冷えすぎて、その
品質が低下することがあつた。
しかして、従来以上の如きコンテナ冷凍装置に
おいて、庫内温度の温度制御を行なう方法とし
て、蒸発器の吹出空気温度を感知して、サーモス
タツトにより圧縮機の運転をオン、オフさせる方
法や、また、高圧ガス管と低圧液管との間にキヤ
ピラリーチユーブ又は膨張弁をもつたホツトガス
バイパス管を介装して、ホツトガスを直接蒸発器
に流して庫内温度を制御する方法が知られてい
る。
しかしながら、圧縮機をオン、オフさせて行な
う制御方式によれば、庫内温度の設定値に対し庫
内における実際の温度の振れが大きく、所謂設定
値に対する温度のハンチング幅が大きい問題があ
り、また、ホツトガスバイパス方式によれば、前
記した圧縮機のオン、オフ方式に比較して、温度
設定値に対するハンチング幅を狭くできるのであ
るが、前記ホツトガスバイパス管を特別に設ける
必要があるし、その上単にホツトガスをバイパス
させるだけであるから、第５図点線の如く外気温
度が低い場合冷凍能力が大きくなり過ぎ、ホツト
ガスをバイパスさせても、前記したハンチング幅
が大きくなる問題があつた。
以上の如く、従来装置によれば、例えホツトガ
スをバイパスさせても、外気温度が低下すると冷
凍能力が大きくなり過ぎるため、温度の制御性が
悪く、消費動力が無駄になると同時に、積荷が冷
えすぎて品質低下を与える問題があつた。
以上の問題は、第５図点線に示した如く、外気
温度が低くなるにつれて、熱負荷は小さくなるの
に対し、冷凍能力は逆に大きくなるもので、負荷
特性と冷凍能力特性とが逆方向の傾向になつてい
ることによるものである。
そこで、本発明は以上の問題点に鑑み発明した
ものであつて、従来装置の如くホツトガスを用い
ないで、第５図実線に示した如く負荷の減少に合
わせて冷凍能力も減少させるようにして、前記し
た消費動力の無駄をなくすると同時に、庫内の温
度制御を良好に行なえ、外気温度の如何に拘わら
ず、常に、設定値に対する温度のハンチング幅を
狭くできるようにしたものであつて、圧縮機と凝
縮器及び蒸発器とを備え、前記凝縮器と蒸発器と
の間に冷凍運転可能とする膨張機構を介装した冷
凍装置において、前記凝縮器と膨張機構とを結ぶ
高圧液管に制御対象空気温度が所定の温度より高
いとき開となり、前記所定温度以下のとき閉とな
る第１開閉弁を介装すると共に、前記蒸発器へ流
れる液冷媒に前記膨張機構による抵抗より大きい
抵抗を与える固定絞り機構を設けて、この固定絞
り機構を前記第１開閉弁と並列に接続したことを
特徴とするものである。
次に本発明装置の実施例を第１図に基づいて説
明する。
第１図において、１は圧縮機、２は凝縮器、３
は膨張機構、４は分流器、５は蒸発器であつて、
これら各機器は冷媒配管６によりそれぞれ連結
し、前記蒸発器５によりコンテナ庫内を冷却する
冷凍サイクルを形成している。
そして以上の如く構成する冷凍サイクルにおけ
る高圧液管６１に制御対象空気温度が所定の温度
より高いとき開となり、前記所定温度以下のとき
閉となる第１開閉弁７を介装すると共に、前記膨
張機構３より絞り抵抗の大きいキヤピラリーチユ
ーブやオリフイスなどの固定絞り機構９（以下単
にキヤピラリーチユーブという）を前記第１開閉
弁７と並列に接続したのである。
前記直列回路１０の出口側は、第１図において
は前記膨張機構３の入口側に接続したが、第２図
の如く前記膨張機構３の出口側でもよいし、前記
蒸発器５の入口側でもよい。
又、前記第１及び第２開閉弁７，８は、何れも
主として電磁開閉弁を用いるもで、以下実施例の
説明では、単に電磁弁と称する。
しかして、前記第１及び第２電磁弁７，８は、
庫内温度を検出し、この検出信号をもとに開閉制
御するのであつて、前記第１電磁弁７は、庫内温
度が設定温度（例えば０℃）に対し適温上限L1
以上において、開となり適温上限L1以下で閉と
なる如く制御すると共に、前記第２電磁弁８は、
前記設定温度以上において開となり、設定温度以
下で閉となる如く制御するのである。
しかして前記第１電磁弁７を閉操作して前記固
定絞り機構を機構を構成するキヤピラリーチユー
ブ９に冷媒を流した場合、該キヤピラリーチユー
ブ９により、前記蒸発器５を流れる液冷媒に、前
記膨張機構３による抵抗よりも大きい抵抗を与え
るのである。
以上の構成において、庫内温度を０℃の設定温
度に制御すべく冷蔵運転を行なう場合、庫内温度
が、適温上限より高いプルダウン時、前記第１電
磁弁７は開となり、通常の冷凍サイクルにより、
庫内を冷却するのである。
そして、第３図の如く庫内温度が設定温度に近
づき適温上限（第３図イ点）になると、前記第１
電磁弁７が閉じる。このとき、前記第２電磁弁８
は開であるから、凝縮器２からの高圧液冷媒が前
記キヤピラリーチユーブ９を介装した直列回路１
０を経て前記膨張弁３から蒸発器５に流れる制御
回路が形成され、この制御回路を流れる冷凍サイ
クルにより冷凍能力が減少傾向に制御された状態
で、庫内を冷却するのである。
従つて、庫内温度の低下は、前記適温上限イか
ら緩慢となり、ゆるやかな温度低下で設定温度
（第３図ロ点）に至るのである。
又、庫内温度が設定温度になると、前記第２電
磁弁８が閉じるのであつて、この第２電磁弁８の
閉鎖により、低圧が低下し、低圧カツトによりポ
ンプダウンして前記圧縮機１の運転が停止するの
である。
この圧縮機１の停止により冷媒の循環はなくな
るが、オーバーシユートにより庫内温度は設定温
度以下となる。
その後庫内温度が上昇し、前記適温上限L1以
下の第３図ハ点になると、前記圧縮機１が運転さ
れるのであるが、この場合前記第２電磁弁８が開
いた状態で運転されるのであつて、前記した適温
上限L1から設定温度に制御する冷凍サイクルと
同じサイクルで庫内を冷却するのであり、以後以
上の運転を繰返して、庫内温度を制御するのであ
る。
又、前記蒸発器５には、図示していないが電気
ヒータを付設し、このヒータを、庫内温度の検出
信号でオン、オフさせる如く成すのであつて、外
気温度が設定温度より低く、庫内温度が外気温度
の影響を受けて設定温度より低い適温下限L2以
下になると、前記第１電磁弁７と共に前記第２電
磁弁８も閉じた状態で、前記蒸発器５に付設する
前記電気ヒータをオンして、該ヒータにより庫内
を加熱するのである。
しかして、以上の運転において、庫内温度が適
温範囲L1〜L2になると、前記したキヤピラリー
チユーブ９を通る制御回路により運転し、冷凍能
力を低く制御するので、圧縮機１の入力を減少
し、消費動力を少なくできると共に、第５図実線
で示した如く冷凍能力を負荷に追従して制御でき
るのであり、従つて、オーバーシユートを少なく
し、設定温度に対する温度のハンチング幅を狭
く、庫内温度を精度よく制御できるのである。
因みに、前記キヤピラリーチユーブ９を、直径
２mm長さ500mmとし、庫内温度の設定温度を０℃
とした場合、その圧縮機入力KWは第４図の如く
なり、外気温度10℃〜40℃まで変化させた平均で
は、第４図点線で示した、ホツトガスバイパス方
式の従来装置によると、5.37KWであるのに対
し、実線で示した本発明装置によると、
3.475KWとなり、従来装置を100％とした場合、
本発明装置は65％となり、35％の消費動力の無駄
を省くことができたのである。
次に以上の如く圧縮機入力が減少する理由及び
冷凍能力を負荷に追従できる理由について説明す
る。
先ず、圧縮機入力が減少する理由について説明
する。
ホツトガスをバイパスさせて、庫内温度の温度
制御を行なう従来装置によれば、外気温度が低い
場合や、庫内温度が適温範囲に入つてホツトガス
のバイパスにより温度制御する場合など熱負荷が
少ない場合でも、外気温度が高く、また庫内温度
が適温範囲より高くプルダウン運転を行なう場合
と同様、冷媒の循環量は変らず多く流れると共
に、冷却能力も変化せず大きいため、ホツトガス
による加熱能力もヒートバランスを行なう必要
上、多く要求し、その結果、冷媒循環量が多くな
り、それだけ圧縮機入力も大きくなるのである。
之に対し本発明装置では、外気温度が低い場合
や庫内温度が適温範囲に入つて熱負荷が少なくな
る場合、第１電磁弁７が閉じ、冷媒はその全量が
第２電磁弁８からキヤピラリーチユーブ９を通つ
て蒸発器５に至る制御回路が形成されるので、前
記第１電磁弁７が開いてプルダウン運転を行なう
場合に対し、キヤピラリーチユーブ９で絞られた
分だけ低圧圧力が低下して、蒸発器５によりガス
化する冷媒の比体積が増大し、冷媒循環量が減少
すると共に、冷凍能力も減少するのである。
従つて、冷媒循環量は、必要最少限に制御さ
れ、圧縮機入力が減少するのである。
今、外気温度が38℃、庫内の設定温度を０℃し
た場合について、従来装置と本発明装置とを比較
すると次表の通りとなる。
TECHNICAL FIELD The present invention relates to a refrigeration device. For example, a container refrigeration system has two functions: a refrigeration operation that controls the temperature inside the container at -5°C to -6°C or lower, usually -18°C, and a refrigeration operation that controls the temperature inside the container to -5°C to -6°C or higher, usually 0°C to 5°C. Refrigeration operation is carried out to control the temperature at ℃ and preserve the cargo without freezing.The present invention is intended to solve the problems of conventional devices in refrigeration operation among the above-mentioned operations. be. In other words, container refrigeration equipment is usually designed based on the required refrigeration capacity during the above-mentioned refrigeration operation, and in many cases, the outside temperature is 38°C and the internal temperature is -18°C.
It is designed to have a refrigeration capacity (approximately 2500Kcal/h) that can maintain the temperature at ℃. Therefore, in refrigeration operation,
As the evaporation temperature increases, the refrigerator will be operated at approximately 2 to 3 times the refrigeration capacity, and as a result, the temperature inside the refrigerator will be loosely controlled during refrigeration operation, and in some cases, meat, vegetables, fruits, etc. In some cases, cargoes became too cold and their quality deteriorated. Therefore, in conventional container refrigeration systems, methods for controlling the internal temperature include sensing the temperature of the air blown from the evaporator and turning on and off the compressor using a thermostat; A known method is to interpose a hot gas bypass pipe with a capillary reach tube or an expansion valve between the high pressure gas pipe and the low pressure liquid pipe to flow the hot gas directly to the evaporator to control the temperature inside the refrigerator. There is. However, according to the control method in which the compressor is turned on and off, there is a problem that the actual temperature inside the refrigerator fluctuates widely with respect to the set value of the temperature inside the refrigerator, and the so-called hunting width of the temperature with respect to the set value is large. Furthermore, according to the hot gas bypass method, the hunting width for the temperature set value can be narrowed compared to the compressor on/off method described above, but it is necessary to specially provide the hot gas bypass pipe. Moreover, since the hot gas is simply bypassed, the refrigeration capacity becomes too large when the outside temperature is low as shown by the dotted line in Figure 5, and even if the hot gas is bypassed, there is a problem that the hunting width described above increases. As described above, with conventional equipment, even if the hot gas is bypassed, the refrigeration capacity becomes too large when the outside temperature drops, making it difficult to control the temperature, wasting power consumption, and causing the cargo to become too cold. There was a problem with quality deterioration. As shown by the dotted line in Figure 5, the above problem is that as the outside temperature decreases, the heat load decreases, but the refrigerating capacity increases, and the load characteristics and the refrigerating capacity characteristics are in opposite directions. This is due to the fact that this is becoming a trend. Therefore, the present invention was devised in view of the above problems, and instead of using hot gas as in the conventional system, the refrigerating capacity is reduced in accordance with the reduction in load as shown by the solid line in Figure 5. , which eliminates the waste of power consumption as described above, and at the same time, can perform good temperature control inside the refrigerator, and can always narrow the temperature hunting range with respect to the set value, regardless of the outside temperature. In a refrigeration system comprising a compressor, a condenser, and an evaporator, and an expansion mechanism interposed between the condenser and the evaporator to enable refrigeration operation, a high-pressure liquid pipe connecting the condenser and the expansion mechanism is provided. A first on-off valve is provided that opens when the temperature of the air to be controlled is higher than a predetermined temperature and closes when the temperature is below the predetermined temperature, and a resistance greater than the resistance caused by the expansion mechanism is provided to the liquid refrigerant flowing to the evaporator. The present invention is characterized in that a fixed throttle mechanism is provided, and the fixed throttle mechanism is connected in parallel with the first on-off valve. Next, an embodiment of the device of the present invention will be described based on FIG. In Fig. 1, 1 is a compressor, 2 is a condenser, and 3 is a compressor.
is an expansion mechanism, 4 is a flow divider, 5 is an evaporator,
These devices are connected to each other by refrigerant pipes 6, and form a refrigeration cycle in which the evaporator 5 cools the inside of the container. The high-pressure liquid pipe 61 in the refrigeration cycle configured as described above is provided with a first on-off valve 7 that opens when the temperature of the air to be controlled is higher than a predetermined temperature and closes when the temperature is below the predetermined temperature. A fixed throttle mechanism 9 (hereinafter simply referred to as capillary reach tube), such as a capillary reach tube or orifice, which has a larger throttle resistance than the mechanism 3, is connected in parallel with the first on-off valve 7. Although the outlet side of the series circuit 10 is connected to the inlet side of the expansion mechanism 3 in FIG. 1, it may be connected to the outlet side of the expansion mechanism 3 as shown in FIG. 2, or the inlet side of the evaporator 5. good. The first and second on-off valves 7 and 8 are both mainly electromagnetic on-off valves, and will be simply referred to as electromagnetic valves in the following description of the embodiments. Therefore, the first and second solenoid valves 7 and 8 are
The first solenoid valve 7 detects the temperature inside the refrigerator and controls opening and closing based on this detection signal .
In the above, the second solenoid valve 8 is controlled so as to be opened and closed when the upper limit of optimum temperature L1 is below, and the second solenoid valve 8 is
It is controlled so that it is open when the temperature is above the set temperature and closed when the temperature is below the set temperature. When the first electromagnetic valve 7 is closed to cause the refrigerant to flow through the capillary reach tube 9 that constitutes the fixed throttle mechanism, the capillary reach tube 9 causes the liquid refrigerant flowing through the evaporator 5 to This provides a resistance greater than the resistance provided by the expansion mechanism 3. In the above configuration, when performing a refrigeration operation to control the temperature inside the refrigerator to a set temperature of 0° C., when the temperature inside the refrigerator is pulled down to a temperature higher than the upper limit of the optimum temperature, the first solenoid valve 7 is opened and the normal refrigeration cycle is resumed. According to
This cools the inside of the refrigerator. As shown in Fig. 3, when the temperature inside the refrigerator approaches the set temperature and reaches the upper limit of the optimum temperature (point A in Fig. 3), the first
Solenoid valve 7 closes. At this time, the second solenoid valve 8
is open, the high-pressure liquid refrigerant from the condenser 2 flows into the series circuit 1 with the capillary reach tube 9 interposed.
A control circuit is formed in which the flow flows from the expansion valve 3 to the evaporator 5 via the expansion valve 3, and the inside of the refrigerator is cooled while the refrigeration capacity is controlled to decrease by the refrigeration cycle flowing through this control circuit. Therefore, the internal temperature decreases slowly from the above-mentioned upper limit of optimum temperature A, and the temperature gradually decreases to reach the set temperature (point B in FIG. 3). Furthermore, when the temperature inside the refrigerator reaches the set temperature, the second solenoid valve 8 is closed. Due to the closing of the second solenoid valve 8, the low pressure is lowered, and the low pressure is pumped down by the low pressure cut, and the compressor 1 is pumped down. The operation will stop. By stopping the compressor 1, the circulation of refrigerant is stopped, but due to overshoot, the temperature inside the refrigerator falls below the set temperature. Thereafter, when the temperature inside the refrigerator rises and reaches point C in FIG. 3 , which is below the upper limit L1 of the optimum temperature, the compressor 1 is operated, but in this case, the compressor 1 is operated with the second solenoid valve 8 open. Therefore, the inside of the refrigerator is cooled in the same cycle as the refrigeration cycle that controls the temperature from the upper limit L1 of the optimum temperature to the set temperature, and the above operation is repeated thereafter to control the temperature inside the refrigerator. Further, the evaporator 5 is equipped with an electric heater (not shown), and this heater is turned on and off by a detection signal of the temperature inside the refrigerator. When the internal temperature becomes equal to or lower than the appropriate temperature lower limit L2 , which is lower than the set temperature due to the influence of the outside air temperature, the second solenoid valve 8 is closed together with the first solenoid valve 7, and the electric power attached to the evaporator 5 is closed. The heater is turned on and the inside of the refrigerator is heated by the heater. In the above operation, when the temperature inside the refrigerator reaches the appropriate temperature range L 1 to L 2 , the control circuit passing through the capillary reach tube 9 operates to control the refrigerating capacity to a low level, so that the input to the compressor 1 is reduced. In addition to reducing power consumption, the refrigeration capacity can be controlled to follow the load as shown by the solid line in Figure 5. Therefore, overshoot can be reduced and the hunting width of the temperature relative to the set temperature can be narrowed. , the temperature inside the refrigerator can be controlled with high precision. Incidentally, the capillary reach tube 9 has a diameter of 2 mm and a length of 500 mm, and the temperature inside the refrigerator is set to 0°C.
In this case, the compressor input KW will be as shown in Figure 4, and on average when the outside air temperature is varied from 10℃ to 40℃, it will be 5.37 according to the conventional hot gas bypass system shown by the dotted line in Figure 4. KW, whereas according to the device of the present invention shown by the solid line,
It becomes 3.475KW, and when the conventional equipment is taken as 100%,
The device of the present invention was able to save 35% of power consumption by 65%. Next, the reason why the compressor input decreases as described above and the reason why the refrigerating capacity can follow the load will be explained. First, the reason why the compressor input decreases will be explained. According to the conventional device that controls the temperature inside the refrigerator by bypassing the hot gas, it is possible to control the temperature inside the refrigerator by bypassing the hot gas when the heat load is small, such as when the outside air temperature is low or when the temperature inside the refrigerator falls within the appropriate temperature range and controls the temperature by bypassing the hot gas. However, as in the case of pull-down operation when the outside temperature is high and the internal temperature is higher than the appropriate temperature range, the amount of refrigerant circulating remains unchanged and increases, and the cooling capacity remains unchanged and large, so the heating capacity of hot gas also increases. The need for balancing requires more, resulting in a greater amount of refrigerant circulation and a correspondingly greater compressor input. In contrast, in the device of the present invention, when the outside temperature is low or when the internal temperature falls within the appropriate temperature range and the heat load decreases, the first solenoid valve 7 closes and the entire amount of refrigerant is discharged from the second solenoid valve 8. Since a control circuit is formed that passes through the capillary reach tube 9 and reaches the evaporator 5, when the first solenoid valve 7 is opened to perform a pull-down operation, the low pressure decreases by the amount throttled by the capillary reach tube 9. As a result, the specific volume of the refrigerant gasified by the evaporator 5 increases, the amount of refrigerant circulation decreases, and the refrigerating capacity also decreases. Therefore, the refrigerant circulation amount is controlled to the minimum necessary amount, and the compressor input is reduced. Now, when the outside temperature is 38°C and the set temperature inside the refrigerator is 0°C, the conventional device and the device of the present invention are compared as shown in the following table.
【表】【table】
【表】
以上の表から明らかな通り、本発明装置におけ
る冷媒循環量は、従来装置を100％とした場合、
33.5％に減少でき、圧縮機入力は従来装置を100
％としたとき、計算値では52.6％、実測値では
57.7％に減少できるのである。
尚、以上の表におけるピストンの理論押しのけ
量は、シリンダ内径58mm、ストローク60mm、気筒
数２、回転数1750rpmで計算したものである。
次に本発明において、冷凍能力を負荷に追従し
て制御できる理由を説明する。
一般に、冷凍能力は、蒸発温度が一定であれ
ば、凝縮温度が低下する毎に大きくなると共に、
蒸発温度が低下すれば冷凍能力も小さくなるので
あり、また、冷凍能力（Kcal／ｈ）は、冷媒循
環量（Kg／ｈ）と冷凍効果（Kcal／Kg）との積
であり、冷媒循環量が減少すれば、冷凍能力も小
さくなるのである。
しかして、本発明装置は、庫内温度が適温範囲
に入ると、第１電磁弁７が閉じ、キヤピラリーチ
ユーブ９を通る制御回路が形成されるので、前記
した如く冷媒循環量が減り、低圧も低くなつて蒸
発温度が低下し、冷凍能力は低くなる。
そして、この状態で外気温度が低くなると、高
圧が低下し、前記キヤピラリーチユーブ９を流れ
る冷媒量（Kg／ｈ）が少なくなる。
又、前記キヤピラリーチユーブ９を流れる冷媒
量により冷媒循環量が決定されるが、この循環量
Ｇは次式により概算できる。
但しΔＰは、キヤピラリーチユーブ９における
前後の差圧であり、γはキヤピラリーチユーブ９
の入口における冷媒の比体積（cm3／Kg）である。
従つて、外気温度が高いと、高圧も高くなつ
て、前記差圧（ΔＰ）は大きくなると共に、外気
温度が低くなると高圧が低くなつて、前記差圧
（ΔＰ）は小さくなるのであり、また、キヤピラ
リーチユーブ９を通る冷媒は何れも液冷媒であつ
て、比体積はほゞ同じであるから、外気温度が低
い方が冷媒循環量がより多く減少し、しかも低圧
低下も大きいから、冷凍能力は第５図実線に示し
た如く、外気温度の低下に伴ない小さくなる如く
制御でき、第５図斜線で示した熱負荷に追従させ
られるのである。
しかして、以上の構成において、前記キヤピラ
リーチユーブ９を、適正な絞り抵抗のものを選択
することにより、第５図実線で示した冷凍能力特
性を負荷特性に近似させることが可能となるので
ある。
即ち、キヤピラリーチユーブ９の抵抗が小さい
場合、高低圧力差が小さくなつて、キヤピラリー
チユーブ９の流量も大きくなり、冷凍能力の減少
はそれ丈少ないため、冷凍能力の特性は、第５図
点線で示した従来装置における冷凍能力の特性と
同様右下りとなる。之に対し、前記キヤピラリー
チユーブ９の抵抗を大きくすると、それ丈低圧の
低下も大きくでき、高低圧力差が大きくなつてキ
ヤピラリーチユーブ９の流量を減少できるので、
冷凍能力の減少を大きくでき、冷凍能力の特性を
第５図実線の如く左下りの特性に制御できる。
従つて、キヤピラリーチユーブ９の抵抗は、冷
凍能力が第５図実線の如く左下りの特性となる如
く選択するのである。
今、前記した如く、直径２mm、長さ500mmとし
たキヤピラリーチユーブ９を用いた構成におい
て、外気温度9.55℃の場合Ａと31.06℃の場合Ｂ
とを比較すると、次表の如くなる。[Table] As is clear from the table above, the refrigerant circulation amount in the device of the present invention is 100% compared to the conventional device.
The compressor input can be reduced to 33.5% compared to the conventional equipment.
When expressed as %, the calculated value is 52.6%, and the actual measured value is 52.6%.
This can be reduced to 57.7%. The theoretical displacement of the piston in the above table was calculated using a cylinder inner diameter of 58 mm, stroke of 60 mm, number of cylinders: 2, and rotation speed of 1750 rpm. Next, in the present invention, the reason why the refrigerating capacity can be controlled in accordance with the load will be explained. Generally, if the evaporation temperature is constant, the refrigeration capacity increases as the condensation temperature decreases.
If the evaporation temperature decreases, the refrigerating capacity also decreases, and the refrigerating capacity (Kcal/h) is the product of the refrigerant circulation amount (Kg/h) and the refrigeration effect (Kcal/Kg), and the refrigerant circulation amount If the amount decreases, the refrigeration capacity also decreases. Therefore, in the device of the present invention, when the temperature inside the refrigerator falls within the appropriate temperature range, the first solenoid valve 7 closes and a control circuit passing through the capillary reach tube 9 is formed. As the temperature decreases, the evaporation temperature decreases, and the refrigerating capacity decreases. In this state, when the outside air temperature becomes low, the high pressure decreases and the amount of refrigerant flowing through the capillary reach tube 9 (Kg/h) decreases. Further, the amount of refrigerant circulating is determined by the amount of refrigerant flowing through the capillary reach tube 9, and this circulating amount G can be approximately estimated by the following equation. However, ΔP is the differential pressure before and after the capillary reach tube 9, and γ is the pressure difference between the front and rear of the capillary reach tube 9.
is the specific volume of refrigerant (cm 3 /Kg) at the inlet of Therefore, when the outside air temperature is high, the high pressure also becomes high and the differential pressure (ΔP) becomes large, and when the outside temperature becomes low, the high pressure becomes low and the differential pressure (ΔP) becomes small. , the refrigerant passing through the capillary reach tube 9 is a liquid refrigerant and has almost the same specific volume, so the lower the outside temperature, the more the refrigerant circulation amount decreases, and the lower the pressure drop is also larger, so the refrigeration As shown by the solid line in FIG. 5, the capacity can be controlled to decrease as the outside temperature decreases, and can be made to follow the heat load shown by the diagonal line in FIG. Therefore, in the above configuration, by selecting the capillary reach tube 9 with an appropriate throttling resistance, it is possible to approximate the refrigerating capacity characteristic shown by the solid line in FIG. 5 to the load characteristic. . That is, when the resistance of the capillary reach tube 9 is small, the difference between high and low pressures becomes small and the flow rate of the capillary reach tube 9 becomes large, and the reduction in the refrigerating capacity is small, so the characteristics of the refrigerating capacity are as shown by the dotted line in Figure 5. Similar to the characteristics of the refrigerating capacity in the conventional device shown in , it slopes downward to the right. On the other hand, if the resistance of the capillary reach tube 9 is increased, the drop in the low pressure can be increased, and the difference between high and low pressures is increased, and the flow rate of the capillary reach tube 9 can be reduced.
The reduction in the refrigerating capacity can be increased, and the characteristic of the refrigerating capacity can be controlled to a downward-sloping characteristic to the left as shown by the solid line in FIG. Therefore, the resistance of the capillary reach tube 9 is selected so that the refrigerating capacity has a downward-sloping characteristic as shown by the solid line in FIG. As mentioned above, in the configuration using the capillary reach tube 9 with a diameter of 2 mm and a length of 500 mm, case A when the outside temperature is 9.55°C and case B when the outside temperature is 31.06°C.
A comparison is made as shown in the following table.
【表】【table】
【表】
以上の表から明らかな通り、外気温度がＢから
Ａへと約22.5℃低下した場合、冷媒循環量は、外
気温度の高いＢを100％とすると約26％減少し、
逆に冷凍効果は、外気温度の高いＢを100％とす
ると約18％増加するが、冷媒循環量の減少率の方
が大きいため、冷凍能力は、計算値で約13％、実
測値で約20％低下するのである。
又、前記した能力のキヤピラリーチユーブ９を
用い、第１図に示した構成の本発明装置と膨張弁
をもつホツトガスバイパス管を用いた従来装置と
の外気温度変化に対する冷凍能力の変化を比較し
てみると次表の如くなる。
この表は、何れも庫内温度が適温範囲にあつ
て、本発明装置では、キヤピラリーチユーブ９を
もつ制御回路を用いて温度制御を行ない、また従
来装置ではホツトガスをバイパスして温度制御を
行なつている場合の比較である。[Table] As is clear from the table above, when the outside air temperature decreases by approximately 22.5°C from B to A, the refrigerant circulation amount decreases by approximately 26%, assuming B, which has the highest outside air temperature, as 100%.
Conversely, the refrigeration effect will increase by approximately 18% if B, where the outside temperature is high, is taken as 100%, but the reduction rate in the amount of refrigerant circulation is greater, so the refrigeration capacity will be approximately 13% in the calculated value and approximately 18% in the actual value. That's a 20% decrease. Furthermore, using the capillary reach tube 9 with the above-mentioned capacity, a comparison was made of changes in refrigerating capacity with respect to changes in outside air temperature between the apparatus of the present invention having the configuration shown in FIG. 1 and a conventional apparatus using a hot gas bypass pipe with an expansion valve. The result will be as shown in the following table. This table shows that the temperature inside the refrigerator is within the appropriate temperature range, and the device of the present invention performs temperature control using a control circuit with a capillary reach tube 9, while the conventional device performs temperature control by bypassing hot gas. This is a comparison when it is warm.
【表】【table】
【表】
以上の表から明らかな如く、従来装置では、外
気温度の低下に対し、冷凍能力が大きくなつてい
るが、本発明装置では、外気温度の低下に対し、
冷凍能力も小さくなつている。
以上の如く本発明は、圧縮機１と凝縮器２及び
蒸発器５とを備え、前記凝縮器２と蒸発器５との
間に冷凍運転可能とする膨張機構３を介装した冷
凍装置において、前記凝縮器２と膨張機構３とを
結ぶ高圧液管６１に制御対象空気温度が所定の温
度より高いとき開となり、前記所定温度以下のと
き閉となる第１開閉弁７を介装すると共に、前記
蒸発器５へ流れる液冷媒に前記膨張機構３による
抵抗より大きい抵抗を与える固定絞り機構９を設
けて、この固定絞り機構９を前記第１開閉弁７と
並列に接続したから、冷蔵運転時や、庫内温度が
設定温度に近い適温範囲になつた時などの熱負荷
が小さい場合に、前記キヤピラリーチユーブ９の
みを通る制御回路を形成できるのであり、庫内温
度が設定温度に近い適温範囲になつたとき、前記
制御回路により運転することにより、圧縮機入力
を減少し、消費動力の無駄を少なくできながら、
しかも、冷凍能力の制御は、熱負荷に追従させら
れるのである。その上、庫内温度が適温範囲にな
ると、前記した制御回路により温度制御するの
で、庫内温度の低下を緩慢にでき、因つて、オー
バーシユートを少なくできると共に圧縮機の発停
回数も少なくでき、かつ第３図及び第６図の比較
から明らかな通り、圧縮機の発停のデイフアレン
シヤルも小さくできるのであつて、設定温度に対
する庫内温度のハンチング幅を狭くし、庫内温度
を設定温度に近い温度に精度よく緻密に制御でき
るのである。
即ち、本願発明によると、冷蔵運転等の熱負荷
が小さい場合には、前記開閉弁７の閉操作をして
前記固定絞り機構９に冷媒を流すことにより、冷
凍運転等の熱負荷が大きい場合における前記膨張
機構３のみによる抵抗に比し、前記蒸発器５へ流
れる液冷媒に大きい抵抗を与えるものであるか
ら、前記絞り機構９で大きく絞られた分だけ低圧
圧力が低下することゝなり、この圧力低下に伴な
つて前記蒸発器５によりガス化され、かつ、圧縮
機１へ吸入されるガス冷媒の比体積が増大するこ
とゝなるのであり、また、前記圧縮機１の圧縮容
積は不変であることから、前記した冷媒の比体積
増大により結局冷媒循環量は減少することゝなる
のであつて、従つて、この冷媒循環量の減少によ
り冷凍能力が低減ができるのである。
斯くの如く、冷蔵運転等の熱負荷が小さい場合
には冷媒循環量を低減でき、それによつて冷凍能
力を低減できるのであるから、それだけ圧縮機入
力を減少できて消費動力の無駄を少なくできなが
ら、庫内温度の変化を緩慢にでき、因つて、温度
変化のオーバーシユートを少なくできると共に、
圧縮機１の発停頻度を少なくでき、かつ、圧縮機
の発停のデイフアレンシヤルも小さくできるので
あつて、設定温度に対する庫内温度のハンチング
幅を狭くし、庫内温度を設定温度に近い温度に精
度よく緻密に制御できるに至つたのである。
また、上記の通り、冷蔵運転等の熱負荷が小さ
い場合には、前記開閉弁７の閉操作をして前記絞
り機構９に冷媒を流すことにより、冷凍能力を低
減し、一方、冷凍運転等の熱負荷が大きい場合に
は、前記開閉弁７の開操作をして前記絞り機構９
への冷媒流れを中止して、前記膨張機構３の減圧
のみにより、冷凍能力をフルに発揮できるもので
あるから、従つて、冷凍能力を熱負荷に追従させ
て効率よく制御できるに至つたのである。[Table] As is clear from the above table, in the conventional device, the refrigeration capacity increases as the outside temperature decreases, but in the device of the present invention, the refrigeration capacity increases as the outside temperature decreases.
Refrigeration capacity is also decreasing. As described above, the present invention provides a refrigeration system including a compressor 1, a condenser 2, and an evaporator 5, and an expansion mechanism 3 interposed between the condenser 2 and the evaporator 5 to enable refrigeration operation. A first on-off valve 7 is interposed in the high-pressure liquid pipe 61 connecting the condenser 2 and the expansion mechanism 3, which opens when the temperature of the air to be controlled is higher than a predetermined temperature and closes when the temperature is lower than the predetermined temperature. A fixed throttle mechanism 9 is provided which provides a resistance greater than the resistance of the expansion mechanism 3 to the liquid refrigerant flowing into the evaporator 5, and this fixed throttle mechanism 9 is connected in parallel with the first on-off valve 7, so that during refrigeration operation When the heat load is small, such as when the temperature inside the refrigerator reaches an appropriate temperature range close to the set temperature, a control circuit that passes only through the capillary reach tube 9 can be formed, and the temperature inside the refrigerator reaches an appropriate temperature close to the set temperature. When the range is reached, by operating the control circuit, the compressor input can be reduced and wasteful power consumption can be reduced.
Moreover, the refrigeration capacity can be controlled to follow the heat load. Furthermore, when the temperature inside the refrigerator falls within the appropriate temperature range, the temperature is controlled by the control circuit described above, so the temperature inside the refrigerator decreases slowly, thereby reducing overshoot and the number of times the compressor starts and stops. As is clear from the comparison of Figures 3 and 6, the differential between starting and stopping of the compressor can be reduced, and the hunting width of the temperature inside the refrigerator relative to the set temperature can be narrowed, and the temperature inside the refrigerator can be reduced. The temperature can be precisely and precisely controlled to a temperature close to the set temperature. That is, according to the present invention, when the heat load is small, such as during refrigeration operation, by closing the on-off valve 7 to allow the refrigerant to flow through the fixed throttle mechanism 9, when the heat load is large, such as during refrigeration operation. Since it provides a large resistance to the liquid refrigerant flowing to the evaporator 5 compared to the resistance caused only by the expansion mechanism 3 in , the low pressure is reduced by the amount of the throttle mechanism 9. As this pressure decreases, the specific volume of the gas refrigerant gasified by the evaporator 5 and sucked into the compressor 1 increases, and the compressed volume of the compressor 1 remains unchanged. Therefore, due to the increase in the specific volume of the refrigerant described above, the amount of refrigerant circulation will eventually decrease, and therefore, the refrigerating capacity can be reduced by this reduction in the amount of refrigerant circulation. In this way, when the heat load such as during refrigeration operation is small, the amount of refrigerant circulated can be reduced, thereby reducing the refrigeration capacity, which can reduce the compressor input and reduce wasted power consumption. , it is possible to slow down the change in temperature inside the refrigerator, thereby reducing overshoot of temperature change,
The frequency of starting and stopping of the compressor 1 can be reduced, and the differential between starting and stopping of the compressor can also be reduced, and the hunting width of the temperature inside the refrigerator relative to the set temperature can be narrowed, and the temperature inside the refrigerator can be brought to the set temperature. This made it possible to precisely and precisely control temperatures close to each other. Furthermore, as mentioned above, when the heat load is small such as during refrigeration operation, the refrigerating capacity is reduced by closing the on-off valve 7 and allowing the refrigerant to flow through the throttle mechanism 9. When the heat load is large, the on-off valve 7 is opened and the throttle mechanism 9 is closed.
By stopping the refrigerant flow to the expansion mechanism 3 and depressurizing the expansion mechanism 3, the full refrigerating capacity can be achieved. Therefore, the refrigerating capacity can be efficiently controlled by following the heat load. be.
第１図は本発明装置の実施例を示す冷媒配管系
統図、第２図は別の実施例を示す冷媒配管系統
図、第３図は庫内温度の制御特性図、第４図は外
気温度に対する圧縮機入力の特性図、第５図は外
気温度に対する冷凍能力と熱負荷との特性図、第
６図は従来装置の庫内温度の制御特性図である。
１……圧縮機、２……凝縮器、３……膨張機
構、５……蒸発器、７……第１開閉弁、９……固
定絞り機構、６１……高圧液管。
Fig. 1 is a refrigerant piping system diagram showing an embodiment of the device of the present invention, Fig. 2 is a refrigerant piping system diagram showing another embodiment, Fig. 3 is a control characteristic diagram of the internal temperature, and Fig. 4 is the outside air temperature. FIG. 5 is a characteristic diagram of refrigerating capacity and heat load with respect to outside air temperature, and FIG. 6 is a characteristic diagram of control of internal temperature of a conventional device. DESCRIPTION OF SYMBOLS 1... Compressor, 2... Condenser, 3... Expansion mechanism, 5... Evaporator, 7... First on-off valve, 9... Fixed throttle mechanism, 61... High pressure liquid pipe.
Claims (1)
前記凝縮器２と蒸発器５との間に冷凍運転可能と
する膨張機構３を介装した冷凍装置において、前
記凝縮器２と膨張機構３とを結ぶ高圧液管６１に
制御対象空気温度が所定の温度より高いとき開と
なり、前記所定温度以下のとき閉となる第１開閉
弁７を介装すると共に、前記蒸発器５へ流れる液
冷媒に前記膨張機構３による抵抗より大きい抵抗
を与える固定絞り機構９を設けて、この固定絞り
機構９を前記第１開閉弁７と並列に接続したこと
を特徴とする冷凍装置。1 Comprising a compressor 1, a condenser 2, and an evaporator 5,
In a refrigeration system in which an expansion mechanism 3 is interposed between the condenser 2 and the evaporator 5 to enable refrigeration operation, a high-pressure liquid pipe 61 connecting the condenser 2 and the expansion mechanism 3 has a predetermined air temperature to be controlled. a fixed throttle that provides a first on-off valve 7 that opens when the temperature is higher than the predetermined temperature and closes when the temperature is lower than the predetermined temperature, and provides a resistance greater than the resistance caused by the expansion mechanism 3 to the liquid refrigerant flowing to the evaporator 5; A refrigeration system characterized in that a mechanism 9 is provided, and the fixed throttle mechanism 9 is connected in parallel with the first on-off valve 7.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP13711380A JPS5760161A (en) | 1980-09-30 | 1980-09-30 | Refrigerating plant for container |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP13711380A JPS5760161A (en) | 1980-09-30 | 1980-09-30 | Refrigerating plant for container |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS5760161A JPS5760161A (en) | 1982-04-10 |
| JPS622675B2 true JPS622675B2 (en) | 1987-01-21 |
Family
ID=15191133
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP13711380A Granted JPS5760161A (en) | 1980-09-30 | 1980-09-30 | Refrigerating plant for container |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS5760161A (en) |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS4329014Y1 (en) * | 1964-01-06 | 1968-11-28 | ||
| JPS4916036A (en) * | 1972-06-05 | 1974-02-13 | ||
| JPS5426021A (en) * | 1977-07-29 | 1979-02-27 | Nippon Kokan Kk | Channel steel with valve and method of making said steel |
| JPS5710258B2 (en) * | 1976-09-01 | 1982-02-25 |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS52165551U (en) * | 1976-06-08 | 1977-12-15 | ||
| JPS5710258U (en) * | 1980-06-20 | 1982-01-19 |
-
1980
- 1980-09-30 JP JP13711380A patent/JPS5760161A/en active Granted
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS4329014Y1 (en) * | 1964-01-06 | 1968-11-28 | ||
| JPS4916036A (en) * | 1972-06-05 | 1974-02-13 | ||
| JPS5710258B2 (en) * | 1976-09-01 | 1982-02-25 | ||
| JPS5426021A (en) * | 1977-07-29 | 1979-02-27 | Nippon Kokan Kk | Channel steel with valve and method of making said steel |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS5760161A (en) | 1982-04-10 |
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