JP2506377B2 - Air conditioner and its control method - Google Patents
Air conditioner and its control methodInfo
- Publication number
- JP2506377B2 JP2506377B2 JP62180276A JP18027687A JP2506377B2 JP 2506377 B2 JP2506377 B2 JP 2506377B2 JP 62180276 A JP62180276 A JP 62180276A JP 18027687 A JP18027687 A JP 18027687A JP 2506377 B2 JP2506377 B2 JP 2506377B2
- Authority
- JP
- Japan
- Prior art keywords
- pressure
- superheat
- condensing pressure
- control valve
- 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 - Lifetime
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- Air Conditioning Control Device (AREA)
Description
【発明の詳細な説明】 （産業上の利用分野） 本発明は、通信機械室あるいは電算機室などのような
外気温が低い時でも冷房を必要とし、しかも、外気を直
接取り入れることができない部屋に通用される空気調和
機、及び外気温が低い時の空気調和機の制御方法に関す
るものである。DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention is a room, such as a communication machine room or a computer room, which requires cooling even when the outside temperature is low, and cannot take in outside air directly. The present invention relates to an air conditioner that is commonly used in air conditioners and a method for controlling the air conditioner when the outside air temperature is low.
（従来の技術） 外気温が低い時に、そのまま外気温が高い時と同じ様
に空気調和機を運転すると凝縮圧力が低くなり、蒸発圧
力との圧力差が小さくなって、冷凍サイクル中を循環す
る冷媒流量が減少してしまい過熱度が高くなる、あるい
は、圧縮比が圧縮機のもつ許容最低圧縮比以下になって
しまうという問題があった。これを解決するために、従
来までは、凝縮圧力調節弁（設定凝縮圧力不変）を用い
て、凝縮圧力をある一定値以下には下がらないように調
節して、過熱度が高くなるあるいは圧縮比が小さくなる
のを抑えていた。しかし、この方法は、外気温が低い時
に、凝縮圧力と蒸発圧力との圧力下が小さいため少ない
圧縮動力で空気調和機を運転できる機会を逃し、わざわ
ざ凝縮圧力を高くして蒸発圧力との圧力差を高めて、圧
縮動力を大きくして運転しており、経済的な運転方法と
は言えない。(Prior art) When the outside air temperature is low, operating the air conditioner as it is when the outside air temperature is high will lower the condensation pressure, reduce the pressure difference from the evaporation pressure, and circulate in the refrigeration cycle. There is a problem that the refrigerant flow rate decreases and the degree of superheat increases, or the compression ratio falls below the allowable minimum compression ratio of the compressor. In order to solve this, until now, the condensing pressure control valve (setting condensing pressure invariant) was used to adjust the condensing pressure so that it does not fall below a certain value, and the superheat becomes higher or the compression ratio becomes higher. Was suppressed from becoming small. However, this method misses the opportunity to operate the air conditioner with less compression power because the pressure under the condensation pressure and the evaporation pressure is small when the outside air temperature is low. The difference is increased and the compression power is increased, which is not an economical method of operation.
（発明が解決しようとする問題点） 本発明は、従来技術では外気温が低い場合に圧縮動力
を大きくしていた点に鑑みてなされたもので、設定凝縮
圧力可変の凝縮圧力調節弁を設け、圧縮動力の少ない経
済的な空気調和機とその制御方法を提供することを目的
とする。(Problems to be Solved by the Invention) The present invention has been made in view of the fact that in the prior art, the compression power was increased when the outside air temperature was low, and a condensation pressure control valve with a variable set condensation pressure was provided. An object of the present invention is to provide an economical air conditioner with low compression power and a control method thereof.
（問題点を解決するための手段と作用） 本発明は、外気温が低い時に、外気を直接取り入れる
ことなく室内の冷房をしなければならないような空気調
和機に関するもので、圧縮動力の少ない経済的な空気調
和機の運転を可能にするために、設定凝縮圧力可変の凝
縮圧力調節弁を設け、この凝縮圧力調節弁を制御する凝
縮圧力調節弁制御部を設けたことを特徴とする。このよ
うな空気調和機の制御方法は、 （１） 開度可変膨張弁を全開にしても凝縮圧力と蒸発
圧力の圧力差が小さくて冷凍サイクル中を循環する冷媒
流量が少なく過熱度が高くなり開度可変膨張弁による過
熱度制御ができない場合に、設定過熱度と測定過熱度の
差に比例して凝縮圧力調節弁を操作して、すなわち、設
定過熱度より測定過熱度が高い場合には、その差に比例
して設定凝縮圧力を高く設定し、設定過熱度より設定過
熱度が低い場合には、その差に比例して設定凝縮圧力を
低く設定して、過熱度を制御する。(Means and Actions for Solving Problems) The present invention relates to an air conditioner in which indoor air must be cooled without directly taking in outside air when the outside air temperature is low. In order to enable the operation of a typical air conditioner, a condensing pressure control valve having a variable set condensing pressure is provided, and a condensing pressure control valve control unit for controlling the condensing pressure control valve is provided. The control method of such an air conditioner is as follows: (1) Even when the variable opening expansion valve is fully opened, the pressure difference between the condensation pressure and the evaporation pressure is small, the refrigerant flow rate in the refrigeration cycle is small, and the superheat degree is high. When the degree of superheat control with the variable opening expansion valve is not possible, operate the condensation pressure control valve in proportion to the difference between the set superheat and the measured superheat, that is, when the measured superheat is higher than the set superheat. , The set condensing pressure is set high in proportion to the difference, and when the set superheat is lower than the set superheat, the set condensing pressure is set low in proportion to the difference to control the superheat.
（２） 凝縮圧力が低下して、圧縮機の吸入圧力と吐出
圧力との差が圧縮機のもつ許容最低圧縮比より小さくな
った場合に、設定圧力可変の凝縮圧力調節弁で凝縮器を
バイパスする冷媒流量を調節することにより、凝縮圧力
を圧縮機の許容最低圧縮比以上となる最低の圧力まで高
める。(2) When the condensation pressure drops and the difference between the suction pressure and the discharge pressure of the compressor becomes smaller than the allowable minimum compression ratio of the compressor, the condenser is bypassed by the condensation pressure control valve with variable set pressure. The condensing pressure is increased to a minimum pressure equal to or higher than the allowable minimum compression ratio of the compressor by adjusting the refrigerant flow rate.
ことを特徴とするものである。It is characterized by that.
従来の技術とは、外気温が低い時に凝縮圧力が低いこ
とを有効に利用し、圧縮動力の少ない経済的な運動がで
きる点が異なる。This is different from the conventional technique in that the low condensing pressure is effectively used when the outside temperature is low, and economical movement with less compression power can be performed.
（実施例） 以下図面を参照して本発明の実施例を詳細に説明す
る。Embodiments Embodiments of the present invention will be described in detail below with reference to the drawings.
第１図は本発明空気調和機の一実施例を示す。即ち、
回転数制御手段30を有する圧縮機21と、凝縮機22と室外
側送風機27からなる室外熱交換器と、蒸発器24と室内側
送風機28からなる室内熱交換器と、上記室外熱交換器の
バイパス経路36と、上記室外熱交換器を経由する経路
（Ｃ−Ｒ回路）と上記バイパス経路36（Ｂ−Ｒ回路）と
の合流点に設けた凝縮圧力調節弁25と、上記凝縮圧力調
節弁25と上記室内熱交換器の間に設けた開度可変膨張弁
23で構成された冷凍サイクルの空気調和機において、上
記圧縮機21の吐出（凝縮）圧力と、吸入（蒸発）圧力の
比を検出する圧力検出部34と、上記圧縮機21の吸入口で
の過熱度を検出する過熱度検出部33と、上記凝縮圧力調
節弁25を制御するヒータ印加電圧制御手段よりなる凝縮
圧力調節弁制御部29と、上記開度可変膨張弁23を制御す
る膨張弁開度制御手段よりなる開度可変膨張弁制御部31
と、上記圧力検出部34からの吐出（凝縮）圧力信号、吸
入（蒸発）圧力信号並びに、上記過熱度検出部33からの
過熱度信号の三つの信号を演算処理して、上記開度可変
膨張弁制御部31並びに凝縮圧力調節弁制御部29に制御信
号を送出する機能と、予め設定した過熱度設定値並びに
上記圧縮機21の許容最低圧縮比と、上記冷凍サイクル運
転中での過熱度検出部33からの測定過熱度並びに上記圧
力検出部34からの測定圧力比を比較演算して、上記凝縮
圧力調節弁制御部29並びに開度可変膨張弁制御部31に制
御信号を送出する機能とを有する制御装置部35とから空
気調和機が構成される。26はレシーバ、32は室温検出手
段である。FIG. 1 shows an embodiment of the air conditioner of the present invention. That is,
A compressor 21 having a rotation speed control means 30, an outdoor heat exchanger consisting of a condenser 22 and an outdoor blower 27, an indoor heat exchanger consisting of an evaporator 24 and an indoor blower 28, and the outdoor heat exchanger. Condensation pressure control valve 25 provided at the confluence of the bypass path 36, the path (CR circuit) passing through the outdoor heat exchanger, and the bypass path 36 (BR circuit), and the condensation pressure control valve Variable opening expansion valve provided between the indoor heat exchanger 25 and the indoor heat exchanger
In the air conditioner of the refrigeration cycle configured by 23, the pressure detection unit 34 that detects the ratio of the discharge (condensing) pressure of the compressor 21 and the suction (evaporating) pressure, and the suction port of the compressor 21 A superheat detection unit 33 for detecting the degree of superheat, a condensing pressure control valve control unit 29 including heater applied voltage control means for controlling the condensing pressure control valve 25, and an expansion valve opening for controlling the opening degree variable expansion valve 23. Degree-variable expansion valve control unit 31 including a degree control means
And the discharge (condensation) pressure signal, the suction (evaporation) pressure signal from the pressure detection unit 34, and the superheat degree signal from the superheat degree detection unit 33 are arithmetically processed to obtain the variable opening degree expansion. A function of sending a control signal to the valve control unit 31 and the condensing pressure control valve control unit 29, a preset superheat degree setting value, an allowable minimum compression ratio of the compressor 21, and a superheat detection during the refrigeration cycle operation. A function of sending a control signal to the condensation pressure control valve control unit 29 and the opening degree variable expansion valve control unit 31 by comparing and calculating the measured superheat degree from the unit 33 and the measured pressure ratio from the pressure detection unit 34. An air conditioner is configured from the control device unit 35 included therein. 26 is a receiver and 32 is a room temperature detecting means.
次に、設定凝縮圧力可変の凝縮圧力調節弁25について
説明する。第３図に凝縮圧力調節弁25の内部構造図を示
す。ダイヤフラム内室２は導管11によって感熱筒９に通
じている。感熱筒９内には温度によりその圧力が変化す
る液ガス混合体が密封されており、この中に埋め込まれ
たヒーター10に通電するとガス体の温度が上昇し、結果
としてダイヤフラム室２の圧力も上昇する。従って、ヒ
ーター10への電力量を加減することによりダイヤフラム
室２の圧力を任意に調節することができ、そのため、凝
縮器22の圧力も任意に調節することができる。例えば、
外気温が低いために凝縮圧力が下がり過ぎていて凝縮圧
力を高くする必要がある場合には、ヒーター10への電力
量を増すことにより弁部５は室外熱交換器を経由する経
路（Ｃ−Ｒ回路）を閉じ、バイパス経路（Ｂ−Ｒ回路）
を開にする。Ｃ−Ｒ回路が閉ざされると凝縮器22内に液
冷媒が蓄積し、凝縮器22の有効面積を減少させることに
より、凝縮圧力を上昇させる。凝縮圧力が上昇して設定
圧力を越えると弁部５が上昇し、Ｃ−Ｒ回路を開き、Ｂ
−Ｒ回路を閉じる。このようにして、ヒーター10への加
熱量を調節することにより任意の値に凝縮圧力を設定す
ることができる。第３図中、１は冷媒入口、３はダイヤ
フラム外室、４はスプリング、６は冷媒出口、７は本
体、８はダイヤフラム、12は制御装置部からの制御信号
にもとづき、ヒーターを制御するコントローラである。Next, the condensing pressure control valve 25 with variable set condensing pressure will be described. FIG. 3 shows the internal structure of the condensing pressure control valve 25. The diaphragm inner chamber 2 communicates with the heat-sensitive cylinder 9 by a conduit 11. A liquid-gas mixture, the pressure of which changes depending on the temperature, is sealed in the heat-sensitive cylinder 9, and when the heater 10 embedded therein is energized, the temperature of the gas body rises, and as a result, the pressure of the diaphragm chamber 2 also increases. To rise. Therefore, the pressure of the diaphragm chamber 2 can be arbitrarily adjusted by adjusting the amount of electric power to the heater 10, and therefore the pressure of the condenser 22 can also be arbitrarily adjusted. For example,
When the condensing pressure is too low because the outside air temperature is low and the condensing pressure needs to be increased, the valve unit 5 passes through the outdoor heat exchanger by increasing the electric power to the heater 10 (C- R circuit) closed, bypass path (BR circuit)
Open. When the CR circuit is closed, liquid refrigerant accumulates in the condenser 22 and reduces the effective area of the condenser 22, thereby increasing the condensation pressure. When the condensing pressure rises and exceeds the set pressure, the valve section 5 rises, the CR circuit is opened, and B
-Close the R circuit. In this way, the condensation pressure can be set to an arbitrary value by adjusting the heating amount to the heater 10. In FIG. 3, 1 is a refrigerant inlet, 3 is a diaphragm outer chamber, 4 is a spring, 6 is a refrigerant outlet, 7 is a main body, 8 is a diaphragm, and 12 is a controller that controls a heater based on a control signal from a control unit. Is.
次に、本発明による空気調和機運転方法について説明
する。第２図の操作の流れ図を、第１図に操作対象とな
る冷凍サイクルの一例を示す。外気温が低い場合、本運
転方法では、凝縮圧力は成行きにまかせ、できるだけ開
度可変膨張弁23の開度を開けることにより過熱度を制御
する。膨張弁23の開度を大きくする方法としては膨張弁
を複数個並列に並べる方法や所定能力より大きい膨張弁
を取り付ける（例えば冷房能力５［RT］の空調機に冷房
能力10［RT］用の膨張弁を取り付ける）といった方法が
ある。膨張弁23の開度を大きくすることにより、凝縮圧
力が低いため、圧縮機21での圧縮動力が少ない運転がで
きる。しかし、この運転方法も 膨張弁23の開度には限りがあり、膨張弁の数を増や
しすぎる（３個あるいは４個取り付ける）、あるいは能
力のあまりにも大きい膨張弁（冷房能力５［RT］の空調
機に15［RT］用の膨張弁をとりつける）を使うと、過熱
度制御が精度よく行えないためこの方法にも限度があ
る。Next, an air conditioner operating method according to the present invention will be described. FIG. 2 is a flow chart of the operation, and FIG. 1 shows an example of the refrigeration cycle to be operated. When the outside air temperature is low, in the present operating method, the condensing pressure is allowed to reach the limit and the degree of superheat is controlled by opening the opening degree of the opening degree variable expansion valve 23 as much as possible. As a method of increasing the opening degree of the expansion valve 23, a method of arranging a plurality of expansion valves in parallel or mounting an expansion valve having a capacity larger than a predetermined capacity (for example, for an air conditioner having a cooling capacity of 5 [RT], a cooling capacity of 10 [RT] There is a method such as installing an expansion valve). By increasing the opening degree of the expansion valve 23, the condensing pressure is low, so that the compressor 21 can be operated with less compression power. However, in this operating method, the opening degree of the expansion valve 23 is also limited, and the number of expansion valves is increased too much (3 or 4 are installed), or the expansion valves with too large capacity (cooling capacity 5 [RT] If a 15 [RT] expansion valve is attached to the air conditioner), the superheat control cannot be performed accurately, so there is a limit to this method.
圧縮機21には冷凍機油の関係で許容できる最低の圧
縮比がある。The compressor 21 has the lowest allowable compression ratio in relation to the refrigerating machine oil.
などの理由により、外気温が例えば10［℃］以下に下が
ったような場合には、次のような問題が起こる。For example, when the outside temperature drops below 10 degrees Celsius, the following problems occur.
凝縮圧力が下がり過ぎて膨張弁23を全開にしても冷
媒循環量が減少し過熱度が高くなる。Even if the expansion valve 23 is fully opened because the condensing pressure is too low, the refrigerant circulation amount decreases and the degree of superheat increases.
吸入圧力と吐出圧力の圧力比が圧縮機21の許容最低
圧縮比以下になる。The pressure ratio between the suction pressure and the discharge pressure becomes equal to or less than the allowable minimum compression ratio of the compressor 21.
このような状況を回避するためには、凝縮圧力を高く
するより方法がない。しかし、従来までの凝縮圧力調節
弁では設定できる凝縮圧力が一定であるため、これをそ
のまま用いると凝縮圧力は必要以上に高くなり、圧縮動
力が大きくなってしまう。そこで、設定できる凝縮圧力
が変えられる凝縮圧力調節弁25を用いて、必要である最
低の圧力に凝縮圧力を設定する。この方法により、凝縮
圧力をできるだけ低く抑えることができ、圧縮動力の削
減を図ることができる。There is no better way to avoid this situation than to increase the condensing pressure. However, since the condensing pressure that can be set by the conventional condensing pressure control valve is constant, if this is used as it is, the condensing pressure becomes unnecessarily high and the compression power becomes large. Therefore, the condensing pressure control valve 25, which can change the condensing pressure that can be set, is used to set the condensing pressure to the required minimum pressure. By this method, the condensing pressure can be suppressed as low as possible, and the compression power can be reduced.
次に、この操作方法を第２図（ａ），（ｂ）の操作の
流れ図に沿って説明する。空気調和機を起動して運転を
開始し定常状態に達した後、圧縮機21の吸入圧力と吐出
圧力の測定値から圧縮比を算出し、記憶している許容最
低圧縮比と比較する。ここでもし測定圧縮比が許容最低
圧縮比より小さい場合（Ｙ）には、測定圧縮比と許容最
低圧縮比との差に比例して凝縮圧力調節弁25のヒーター
電圧を増し、設定凝縮圧力を高くして圧縮比が許容最低
圧縮比以上となるようにする。しかし、測定圧縮比が許
容最低圧縮比以上（Ｎ）であってもそれが大きすぎるよ
うな場合、たとえば、許容最低圧縮比が2.0なのに設定
凝縮圧力を高くして3.0の圧縮比で運転したような場合
には圧縮動力が大きくなり不経済な運転になる。そこ
で、許容最低圧縮比より測定圧縮比が大きい場合にはそ
の差に比例して凝縮圧力調節弁25のヒーター電圧を減ら
して凝縮圧力を下げ、常に許容最低圧力比付近の圧力比
で空気調和機を運転させる。外気温が高い時で凝縮圧力
調節弁25を働かせないとき（Ｎ）にはそのまま運転す
る。Next, this operation method will be described with reference to the operation flow charts of FIGS. 2 (a) and 2 (b). After the air conditioner is started to start the operation and reaches the steady state, the compression ratio is calculated from the measured values of the suction pressure and the discharge pressure of the compressor 21, and compared with the stored minimum allowable compression ratio. If the measured compression ratio is smaller than the minimum allowable compression ratio (Y), the heater voltage of the condensation pressure control valve 25 is increased in proportion to the difference between the measured compression ratio and the minimum allowable compression ratio to set the set condensation pressure. Increase it so that the compression ratio becomes equal to or higher than the allowable minimum compression ratio. However, if the measured compression ratio is more than the allowable minimum compression ratio (N) and it is too large, for example, even if the allowable minimum compression ratio is 2.0, the set condensing pressure is increased to operate at the compression ratio of 3.0. In that case, the compression power becomes large and the operation becomes uneconomical. Therefore, when the measured compression ratio is larger than the minimum allowable compression ratio, the heater voltage of the condensation pressure control valve 25 is reduced in proportion to the difference to reduce the condensation pressure, and the air conditioner is always operated at a pressure ratio near the minimum allowable compression ratio. To drive. When the outside air temperature is high and the condensation pressure control valve 25 does not work (N), it is operated as it is.
次に、過熱度の制御を行なう。通常の過熱度制御は、
一般に知られているように測定過熱度が設定過熱度より
高ければその差に比例して膨張弁23を開き、逆に、測定
過熱度が設定過熱度より低ければその差に比例して膨張
弁23を閉じる。しかし、外気温が低くなりそれとともに
凝縮圧力も低くなった場合、これまでの説明の通り、膨
張弁23による過熱度制御ができなくなる場合がある。そ
こで、もし、測定過熱度が設定過熱度よりも高く（Ｙ）
しかも膨張弁23が全開（Ｙ）だった場合には、その差に
比例して凝縮圧力調節弁25のヒーター電圧を増して、設
定凝縮圧力を高くして、過熱度を下げる。逆に、測定過
熱度が設定過熱度より低く（Ｎ）しかも凝縮圧力調節弁
25を働かせて（Ｙ）凝縮圧力を高くしている場合には、
測定過熱度と設定過熱度の差に比例して凝縮圧力調節弁
25のヒーター電圧を減らし、過熱度を高くする。この方
法により膨張弁23により過熱度制御ができない場合には
凝縮圧力調節弁25により過熱度制御が行える。Next, the degree of superheat is controlled. Normal superheat control is
As is generally known, if the measured superheat is higher than the set superheat, the expansion valve 23 is opened in proportion to the difference, and conversely, if the measured superheat is lower than the set superheat, the expansion valve is opened in proportion to the difference. Close 23. However, when the outside air temperature becomes low and the condensing pressure also becomes low, the superheat degree control by the expansion valve 23 may not be possible as described above. Therefore, if the measured superheat is higher than the set superheat (Y)
Moreover, when the expansion valve 23 is fully opened (Y), the heater voltage of the condensing pressure control valve 25 is increased in proportion to the difference and the set condensing pressure is increased to reduce the superheat degree. Conversely, the measured superheat is lower than the set superheat (N) and the condensation pressure control valve
When 25 is activated (Y) to increase the condensing pressure,
Condensing pressure control valve proportional to the difference between the measured superheat and the set superheat
Reduce heater voltage at 25 to increase superheat. By this method, when the expansion valve 23 cannot control the superheat degree, the condensing pressure control valve 25 can control the superheat degree.
（発明の効果） 以上の説明より本発明から次のような効果が得られ
る。(Effects of the Invention) From the above description, the following effects can be obtained from the present invention.
（１） 外気温が低い時に空気調和機を運転する場合、
設定圧力可変の凝縮圧力調節弁を用いることにより、膨
張弁が全開になって冷媒循環流量が少なくて過熱度が高
い場合にも、凝縮器をバイパスする冷媒流量を調節して
過熱度制御が行え、しかも、凝縮圧力は必要最低な圧力
に抑えられるため省エネルギーな運転が可能になる。(1) When operating the air conditioner when the outside temperature is low,
By using the condensing pressure control valve with variable set pressure, even if the expansion valve is fully opened and the refrigerant circulation flow rate is low and the superheat degree is high, the superheat degree can be controlled by adjusting the refrigerant flow rate bypassing the condenser. Moreover, since the condensing pressure is suppressed to the necessary minimum pressure, energy-saving operation becomes possible.
（２） 外気温が低い時に空気調和機を運転する場合、
吸入圧力と吐出圧力との比が圧縮機の許容最低圧力比よ
り小さくなっても、設定圧力可変の凝縮圧力調節弁を用
いることにより必要とする最低の圧力に凝縮圧力を設定
することができ、圧縮機を保護しながら省エネルギーな
運転が可能となる。(2) When operating the air conditioner when the outside temperature is low,
Even if the ratio of the suction pressure and the discharge pressure becomes smaller than the allowable minimum pressure ratio of the compressor, the condensation pressure can be set to the minimum required pressure by using the condensation pressure control valve with the variable set pressure. Energy-saving operation is possible while protecting the compressor.
第１図は本発明の一実施例を示す構成説明図、第２図は
本発明の空気調和機の運転操作の一例を示す流れ図、第
３図は本発明に係る凝縮圧力調節弁の一例を示す構造図
である。 １……冷媒入口、２……ダイヤフラム内室、３……ダイ
ヤフラム外室、４……スプリング、５……弁部、６……
冷媒出口、７……本体、８……ダイヤフラム、９……感
熱筒、10……ヒーター、11……導管、12……コントロー
ラ、21……圧縮機、22……凝縮器、23……開度可変膨張
弁、24……蒸発器、25……凝縮圧力調節弁、26……レシ
ーバ、27……室外側送風機、28……室内側送風機、29…
…凝縮圧力調節弁制御部、30……圧縮機回転数制御手
段、31……開度可変膨張弁制御部、32……室温検出手
段、33……過熱度検出部、34……圧力検出部、35……制
御装置部。FIG. 1 is a structural explanatory view showing an embodiment of the present invention, FIG. 2 is a flow chart showing an example of an operation operation of an air conditioner of the present invention, and FIG. 3 is an example of a condensation pressure control valve according to the present invention. FIG. 1 ... Refrigerant inlet, 2 ... Diaphragm inner chamber, 3 ... Diaphragm outer chamber, 4 ... Spring, 5 ... Valve part, 6 ...
Refrigerant outlet, 7 ... Main body, 8 ... Diaphragm, 9 ... Heat sensitive tube, 10 ... Heater, 11 ... Conduit, 12 ... Controller, 21 ... Compressor, 22 ... Condenser, 23 ... Open Degree variable expansion valve, 24 …… evaporator, 25 …… condensing pressure control valve, 26 …… receiver, 27 …… outdoor blower, 28 …… indoor blower, 29 ・ ・ ・
… Condensation pressure control valve control unit, 30 …… Compressor rotation speed control unit, 31 …… Variable opening expansion valve control unit, 32 …… Room temperature detection unit, 33 …… Superheat detection unit, 34 …… Pressure detection unit , 35 …… Control unit.
Claims (4)
の合流点に設けた凝縮圧力調節弁と、 上記凝縮圧力調節弁と上記室内熱交換器の間に設けた開
度可変膨脹弁で構成された冷凍サイクルの空気調和機に
おいて、 上記圧縮機の吐出圧力と吸入圧力の比を検出する圧力検
出部と、 上記圧縮機の吸入口での過熱度を検出する過熱度検出部
と、 上記凝縮圧力調節弁を制御する凝縮圧力調節弁制御部
と、 上記開度可変熱膨脹弁を制御する開度可変膨脹弁制御部
と、 上記圧力検出部からの吐出圧力信号、吸入圧力信号並び
に、上記過熱度検出部からの過熱度信号の三つの信号を
演算処理して、上記開度可変膨脹弁制御部並びに凝縮圧
力調節弁制御部に制御信号を送出する機能と、予め設定
した過熱度設定値並びに上記圧縮機の許容最低圧縮比
と、上記冷凍サイクル運転中での過熱度検出部からの測
定過熱度並びに上記圧力検出部からの測定圧力比を比較
演算して、上記凝縮圧力調節弁制御部並びに開度可変膨
脹弁制御部に制御信号を送出する機能とを有する制御装
置部とからなり、 上記開度可変膨脹弁を全開にしても凝縮圧力と蒸発圧力
の圧力差が小さくて冷凍サイクル中を循環する冷媒流量
が少なく過熱度が高くなり開度可変膨脹弁による過熱度
制御ができない場合に、設定過熱度と測定過熱度の差に
比例して凝縮圧力調節弁を操作することにより、設定過
熱度より測定過熱度が高い場合には、設定過熱度と測定
過熱度の差に比例して設定凝縮圧力を高く設定し、設定
過熱度より測定過熱度が低い場合には、設定過熱度と測
定過熱度の差に比例して設定凝縮圧力を低く設定して、
過熱度を制御し、 凝縮圧力が低下して、圧縮機の吸入圧力と吐出圧力との
差が圧縮機のもつ許容最低圧縮比より小さくなった場合
に、設定圧力可変の凝縮圧力調節弁で凝縮器をバイパス
する冷媒流量を調節することにより、凝縮圧力を圧縮機
の許容最低圧縮比以上となる圧力まで高めることを特徴
とする空気調和機。1. A compressor having rotation control means, an outdoor heat exchanger comprising a condenser and an outdoor blower, an indoor heat exchanger comprising an evaporator and an indoor blower, and a bypass path for the outdoor heat exchanger. And a condensing pressure control valve provided at the confluence of the path passing through the outdoor heat exchanger and the bypass path, and a variable opening expansion valve provided between the condensing pressure control valve and the indoor heat exchanger. In a configured refrigeration cycle air conditioner, a pressure detection unit that detects a ratio between the discharge pressure and the suction pressure of the compressor, a superheat degree detection unit that detects a superheat degree at the suction port of the compressor, and A condensing pressure control valve control unit for controlling the condensing pressure control valve, a variable opening expansion valve control unit for controlling the variable opening thermal expansion valve, a discharge pressure signal from the pressure detecting unit, a suction pressure signal, and the overheat Superheat signal from the temperature detector And the function of sending a control signal to the variable opening expansion valve control unit and the condensing pressure control valve control unit, and the preset superheat setting value and the allowable minimum compression ratio of the compressor. And, by comparing and calculating the measured superheat degree from the superheat degree detection section and the measured pressure ratio from the pressure detection section during the refrigeration cycle operation, the condensation pressure control valve control section and the opening degree variable expansion valve control section And a control device having a function of sending a control signal. Even when the variable opening expansion valve is fully opened, the pressure difference between the condensation pressure and the evaporation pressure is small, the refrigerant flow rate in the refrigeration cycle is small, and the superheat degree is low. When the superheat degree cannot be controlled by the variable opening expansion valve by operating the condensation pressure control valve in proportion to the difference between the set superheat degree and the measured superheat degree, the measured superheat degree is higher than the set superheat degree. Set to If the set condensing pressure is set high in proportion to the difference between the superheat and the measured superheat, and the measured superheat is lower than the set superheat, the set condensing pressure is set in proportion to the difference between the set superheat and the measured superheat. Set it low,
When the difference between the suction pressure and the discharge pressure of the compressor is smaller than the allowable minimum compression ratio of the compressor by controlling the degree of superheat and the condensing pressure decreases, the condensation pressure control valve with variable set pressure condenses An air conditioner characterized by increasing the condensing pressure to a pressure equal to or higher than the allowable minimum compression ratio of the compressor by adjusting the flow rate of the refrigerant bypassing the compressor.
る経路と、バイパス経路との切り換えを行う弁部と、該
弁部に結合・連動されたダイヤフラムと、該ダイヤフラ
ムによって隔離されたダイヤフラム内室、並びにダイヤ
フラム外室と、該ダイヤフラム内室に上記凝縮圧力調節
弁制御部からのガスを導入する導管と、筺体とからなる
ことを特徴とする特許請求の範囲第１項記載の空気調和
機。2. A condensing pressure control valve is provided with a valve section for switching between a path passing through an outdoor heat exchanger and a bypass path, a diaphragm coupled to and interlocking with the valve section, and isolated by the diaphragm. The air according to claim 1, comprising a diaphragm inner chamber, a diaphragm outer chamber, a conduit for introducing gas from the condensing pressure control valve control unit into the diaphragm inner chamber, and a housing. Harmony machine.
熱筒内部に封入されたヒーターと、上記制御装置部から
の制御信号にもとづき、上記ヒーターを制御するコント
ローラと、上記凝縮圧力調節弁のダイヤフラム内室に導
かれる導管とからなることを特徴とする特許請求の範囲
第１項、又は第２項記載の空気調和機。3. A condensing pressure control valve control unit includes a heat sensitive cylinder, a heater enclosed in the heat sensitive cylinder, a controller for controlling the heater based on a control signal from the control unit, and the condensing pressure. The air conditioner according to claim 1 or 2, wherein the air conditioner comprises a conduit which is guided to the inner chamber of the diaphragm of the control valve.
る圧力検出部と、 上記圧縮機の吸入口で過熱度を検出する過熱度検出部
と、 凝縮器と室外側送風機とからなる室外熱交換器と、 蒸発器と室内側送風機とからなる室内熱交換器と、 上記室外熱交換器のバイパス経路と、 上記室外熱交換器を経由する経路と上記バイパス経路と
の合流点に設けた凝縮圧力調節弁と、 上記凝縮圧力調節弁を制御する凝縮圧力調節弁制御部
と、 上記凝縮圧力調節弁と上記室内熱交換器の間に設けた開
度可変膨脹弁と、 上記開度可変膨脹弁を制御する開度可変膨張弁制御部と を有する空気調和機を、 上記開度可変膨脹弁を全開にしても、測定過熱度が予め
設定した設定過熱度より高いときには、設定過熱度と測
定過熱度の差に比例して設定凝縮圧力を高くするよう、
凝縮圧力調節弁制御部に制御信号を送出し、測定過熱度
が設定過熱度より低いときには、設定過熱度と測定過熱
度の差に比例して設定凝縮圧力を低くするよう、凝縮圧
力調節弁制御部に制御信号を送出し、 凝縮圧力が低下して、圧力検出部で検出される設定圧力
比が、予め圧縮機に設定した許容最低圧縮比より小さく
なった場合に、凝縮圧力が圧縮機の許容最低圧縮比より
大きくなるまで、設定圧力可変の凝縮圧力調節弁で凝縮
器をバイパスする冷媒流量を増加させるよう、開度可変
膨脹弁制御部に制御信号を送出する ことを特徴とする空気調和機の制御方法。4. A compressor having rotation control means, a pressure detector for detecting a measured pressure ratio of discharge pressure and suction pressure of the compressor, and superheat detection for detecting superheat at an inlet of the compressor. Section, an outdoor heat exchanger consisting of a condenser and an outdoor blower, an indoor heat exchanger consisting of an evaporator and an indoor blower, a bypass path of the outdoor heat exchanger, and a passage through the outdoor heat exchanger. A condensing pressure control valve provided at the confluence of the bypass passage and the bypass route, a condensing pressure control valve control unit that controls the condensing pressure control valve, and a condensing pressure control valve between the condensing pressure control valve and the indoor heat exchanger. An air conditioner having a variable opening expansion valve and a variable opening expansion valve control unit that controls the variable opening expansion valve, and the measured superheat is preset even when the variable opening expansion valve is fully opened. If it is higher than the set superheat To high setting condensing pressure in proportion to the difference between the constant superheat,
When a control signal is sent to the condensing pressure control valve control unit and the measured superheat degree is lower than the set superheat degree, the condensing pressure control valve is controlled so that the set condensing pressure is lowered in proportion to the difference between the set superheat degree and the measured superheat degree. When a control signal is sent to the compressor and the condensing pressure drops and the set pressure ratio detected by the pressure detector becomes smaller than the allowable minimum compression ratio preset in the compressor, the condensing pressure of the compressor An air conditioner characterized by sending a control signal to the variable opening expansion valve control unit so that the flow rate of the refrigerant bypassing the condenser is increased by the condensing pressure control valve with a variable set pressure until it exceeds the allowable minimum compression ratio. Control method.
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP62180276A JP2506377B2 (en) | 1987-07-20 | 1987-07-20 | Air conditioner and its control method |
| US07/620,374 US5168715A (en) | 1987-07-20 | 1990-11-29 | Cooling apparatus and control method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP62180276A JP2506377B2 (en) | 1987-07-20 | 1987-07-20 | Air conditioner and its control method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS6423060A JPS6423060A (en) | 1989-01-25 |
| JP2506377B2 true JP2506377B2 (en) | 1996-06-12 |
Family
ID=16080390
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP62180276A Expired - Lifetime JP2506377B2 (en) | 1987-07-20 | 1987-07-20 | Air conditioner and its control method |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2506377B2 (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH01273952A (en) * | 1988-04-27 | 1989-11-01 | Hitachi Ltd | Pressure controlling method in freezing cycle |
| JP4616461B2 (en) * | 2000-11-17 | 2011-01-19 | 三菱重工業株式会社 | Air conditioner |
| JP2009079815A (en) * | 2007-09-26 | 2009-04-16 | Sanyo Electric Co Ltd | Heat source side unit, air-conditioner, and air conditioning system |
-
1987
- 1987-07-20 JP JP62180276A patent/JP2506377B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JPS6423060A (en) | 1989-01-25 |
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