JP2009198050A

JP2009198050A - Precision air conditioner

Info

Publication number: JP2009198050A
Application number: JP2008038560A
Authority: JP
Inventors: Katsuhiko Mochizuki; 克彦望月
Original assignee: APISUTE KK; Apiste Corp
Current assignee: APISUTE KK; Apiste Corp
Priority date: 2008-02-20
Filing date: 2008-02-20
Publication date: 2009-09-03

Abstract

<P>PROBLEM TO BE SOLVED: To enhance a dehumidifying capacity, without freezing an evaporator, in a precision air conditioner for blowing a specific air volume in a specific temperature and humidity. <P>SOLUTION: In the precision air conditioner, a hot gas bypass HGB is provided, a refrigerant not passing through a condenser 1 is guided to the evaporator 3, and a control is made so that the temperature of the evaporator 3 does not become lower than a first lower limit value L1, and that the inlet temperature of the evaporator 3 becomes the first target temperature T1. Thus, freezing of the evaporator 3 is prevented. A refrigerant in a third conduit 13 of returning the refrigerant to a compressor 4 from the evaporator 3, is raised in the temperature by the refrigerant in the hot gas bypass HGB. Thus, there is no risk of causing a liquid explosion in the compressor 4. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

本発明は、主として工業用に用いられる精密空調機に関するものである。 The present invention relates to a precision air conditioner mainly used for industrial use.

従来より、冷凍サイクルのみで除湿を行う空調機が知られている（特許文献１）。
特開平５−９９５１４号 Conventionally, an air conditioner that performs dehumidification only by a refrigeration cycle is known (Patent Document 1).
JP-A-5-99514

この種の空調機の場合、除湿能力を高くするために蒸発器の設定温度を下げると、蒸発器が凍結し、除湿能力が著しく低下するので、蒸発器の温度を下げることができず、それ故、除湿能力を今一つ高めることができない。 In the case of this type of air conditioner, if the preset temperature of the evaporator is lowered to increase the dehumidifying capacity, the evaporator will freeze and the dehumidifying capacity will be significantly reduced, so the temperature of the evaporator cannot be lowered. Therefore, the dehumidifying capacity cannot be increased one more time.

一方、工業用の空調機においては、家庭用のものと異なり、常に一定の風量が要求されるので、ファンの回転数を高めて蒸発器の凍結防止を図るなどの方法は採用できない。つまり、工業用の精密空調機では冷凍サイクルのみで除湿する必要がある。 On the other hand, an industrial air conditioner, unlike a household air conditioner, always requires a constant air volume, and therefore cannot adopt a method such as increasing the number of rotations of the fan to prevent the evaporator from freezing. In other words, industrial precision air conditioners need to be dehumidified only by the refrigeration cycle.

したがって、本発明の目的は、一定の温度および湿度で一定の風量を送風する精密空調機において、蒸発器が凍結することなく除湿能力を高めることである。 Accordingly, an object of the present invention is to increase the dehumidifying capacity of a precision air conditioner that blows a constant air volume at a constant temperature and humidity without freezing the evaporator.

前記目的を達成するために、本発明の精密空調機は、図１に示すように、冷媒を冷却するための凝縮器１と、冷媒に流れ抵抗を与えるための膨張弁２と、冷媒で周囲の空気を冷却するための蒸発器３と、前記蒸発器３から凝縮器１および膨張弁２を通って再び蒸発器３に冷媒が循環するように蒸発器３からの冷媒を凝縮器１に圧送する圧縮機４と、前記蒸発器３で除湿すると共に冷却した空気Ａを送風するファン５と、前記空気Ａを加熱して所定の温度まで昇温させるヒータ６とを備えた精密空調機において、前記圧縮機４から凝縮器１に冷媒を導く第１導管１１と、前記凝縮器１から前記蒸発器３に冷媒を導く第２導管１２とを連ねて前記圧縮機４で圧縮された冷媒を前記蒸発器３に導くホットガスバイパスＨＧＢと、前記ホットガスバイパスＨＧＢの流量を制御する制御弁７と、前記ホットガスバイパスＨＧＢを流れる冷媒の熱で前記蒸発器３から前記圧縮機４に戻る冷媒を昇温させる熱交換器８と、前記膨張弁２の出口から前記蒸発器３の入口までにおける任意の部位における冷媒の温度を測定する第１温度センサ２１と、前記熱交換器８の出口から前記圧縮機４の入口までの任意の部位における冷媒の温度を測定する第２温度センサ２２と、前記蒸発器３の入口温度である第１目標温度Ｔ１と、前記蒸発器３の入口温度の第１下限値Ｌ１と、前記圧縮機４の入口温度である第２目標温度Ｔ２と、前記圧縮機４の入口温度の第２下限値Ｌ２とを記憶する制御手段９とを備え、前記第１および第２目標温度Ｔ１、Ｔ２が氷点下に設定され、かつ、前記第１および第２下限値Ｌ１、Ｌ２が前記第１および第２目標温度Ｔ１、Ｔ２よりも低い温度に設定され、前記第１温度センサ２１により第１測定温度Ｓ１が前記第１下限値Ｌ１よりも低くなると当該第１測定温度Ｓ１が前記第１目標温度Ｔ１に近づくように、前記制御弁７の開度を制御してホットガスバイパスＨＧＢの流量が大きくなるように、かつ、前記第２温度センサ２２による第２測定温度Ｓ２が前記第２下限値Ｌ２よりも低くなると当該第２測定温度Ｓ２が前記第２目標温度Ｔ２に近づくように、前記制御弁７の開度を制御してホットガスバイパスＨＧＢの流量が大きくなるように前記制御手段９が制御弁の開度を制御する。 In order to achieve the above object, the precision air conditioner of the present invention includes a condenser 1 for cooling the refrigerant, an expansion valve 2 for giving flow resistance to the refrigerant, and surroundings with the refrigerant as shown in FIG. The evaporator 3 for cooling the air, and the refrigerant from the evaporator 3 is pumped to the condenser 1 so that the refrigerant circulates again from the evaporator 3 through the condenser 1 and the expansion valve 2 to the evaporator 3. In a precision air conditioner including a compressor 4 that performs the above operation, a fan 5 that blows air A that has been dehumidified and cooled by the evaporator 3, and a heater 6 that heats the air A and raises the temperature to a predetermined temperature. The refrigerant compressed by the compressor 4 is connected to the first conduit 11 that guides the refrigerant from the compressor 4 to the condenser 1 and the second conduit 12 that guides the refrigerant from the condenser 1 to the evaporator 3. A hot gas bypass HGB leading to the evaporator 3, and the hot gas bypass A control valve 7 for controlling the flow rate of the gas HGB, a heat exchanger 8 for raising the temperature of the refrigerant returning from the evaporator 3 to the compressor 4 by the heat of the refrigerant flowing through the hot gas bypass HGB, A first temperature sensor 21 that measures the temperature of the refrigerant at an arbitrary position from the outlet to the inlet of the evaporator 3, and the temperature of the refrigerant at an arbitrary position from the outlet of the heat exchanger 8 to the inlet of the compressor 4 A first target temperature T1 that is the inlet temperature of the evaporator 3, a first lower limit value L1 of the inlet temperature of the evaporator 3, and an inlet temperature of the compressor 4. Control means 9 for storing a second target temperature T2 and a second lower limit value L2 of the inlet temperature of the compressor 4, wherein the first and second target temperatures T1, T2 are set below freezing point, and The first and second lower limit values L1 When L2 is set to a temperature lower than the first and second target temperatures T1 and T2, and the first measured temperature S1 becomes lower than the first lower limit L1 by the first temperature sensor 21, the first measured temperature S1 is set. So that the flow rate of the hot gas bypass HGB is increased by controlling the opening degree of the control valve 7 so that the second measured temperature S2 by the second temperature sensor 22 is close to the first target temperature T1. When the temperature falls below the second lower limit L2, the opening of the control valve 7 is controlled so that the flow rate of the hot gas bypass HGB is increased so that the second measured temperature S2 approaches the second target temperature T2. The control means 9 controls the opening degree of the control valve.

図１において、圧縮機４は、蒸発器３において気体となった冷媒を、第１導管１１を介して凝縮器１に圧送し、さらに、凝縮器１から第２導管１２を介して膨張弁２に圧送して循環させる。この際、冷媒は凝縮器１および膨張弁２において、徐々に液化する。冷媒は、膨張弁２から出て、蒸発器３内の比較的太い管内で低圧となって、再び気化することにより、蒸発器３の周囲の熱を奪い、周囲温度を低下させる。一方、ファン５により送風された空気Ａは蒸発器３によって冷やされた後、ヒータ６により所定の温度まで加熱されると共に湿度の低い空気となって吹出口３０から所定のエリアに供給される。 In FIG. 1, the compressor 4 pumps the refrigerant that has become gas in the evaporator 3 to the condenser 1 via the first conduit 11, and further expands the expansion valve 2 from the condenser 1 via the second conduit 12. Circulate by pressure. At this time, the refrigerant gradually liquefies in the condenser 1 and the expansion valve 2. The refrigerant exits from the expansion valve 2, becomes a low pressure in a relatively thick pipe in the evaporator 3, and vaporizes again, thereby taking away the heat around the evaporator 3 and lowering the ambient temperature. On the other hand, after the air A blown by the fan 5 is cooled by the evaporator 3, the air A is heated to a predetermined temperature by the heater 6 and is supplied to a predetermined area from the outlet 30 as air having low humidity.

ここで、蒸発器３の第１目標温度Ｔ１は氷点下に設定されているので、空気Ａの冷却能力が高まり、そのため、除湿能力も高まる。 Here, since the first target temperature T1 of the evaporator 3 is set below the freezing point, the cooling capacity of the air A is increased, and therefore the dehumidifying capacity is also increased.

一方、蒸発器３の第１目標温度Ｔ１は−０℃よりも低いので、蒸発器３の温度が低くなりすぎると蒸発器３の凍結の問題が生じる。これに対し、本精密空調機では、ホットガスバイパスＨＧＢを設け、凝縮器１を通らない冷媒を蒸発器３に導入し、蒸発器３の温度が第１下限値Ｌ１よりも低くならないように制御すると共に、蒸発器３の入口温度が第１目標温度Ｔ１となるように制御する。したがって、蒸発器３の凍結を防止し得る。 On the other hand, since the first target temperature T1 of the evaporator 3 is lower than −0 ° C., if the temperature of the evaporator 3 becomes too low, a problem of freezing of the evaporator 3 occurs. On the other hand, in this precision air conditioner, a hot gas bypass HGB is provided, and a refrigerant that does not pass through the condenser 1 is introduced into the evaporator 3 so that the temperature of the evaporator 3 does not become lower than the first lower limit value L1. At the same time, the inlet temperature of the evaporator 3 is controlled to be the first target temperature T1. Therefore, freezing of the evaporator 3 can be prevented.

なお、第１目標温度Ｔ１および第１下限値Ｌ１は、ファン５による風量、空気Ａの供給時の温度などにより蒸発器３が凍結しない、かつ、できるだけ低い温度に設定する。 The first target temperature T1 and the first lower limit value L1 are set as low as possible without causing the evaporator 3 to freeze due to the air volume by the fan 5, the temperature when the air A is supplied, and the like.

一方、圧縮機４に戻ってくる冷媒の温度が低すぎて流体のまま圧縮機４に戻ってくると、圧縮機４において液バックと呼ばれる不具合が発生する。これに対し、本精密空調機は蒸発器３から圧縮機４に戻る第３導管１３内の冷媒をホットガスバイパスＨＧＢ内の冷媒で昇温させる。そのため、圧縮機４において液バックの生じるおそれもない。 On the other hand, if the temperature of the refrigerant returning to the compressor 4 is too low and returns to the compressor 4 while being fluid, a problem called a liquid back occurs in the compressor 4. In contrast, the precision air conditioner raises the temperature of the refrigerant in the third conduit 13 that returns from the evaporator 3 to the compressor 4 with the refrigerant in the hot gas bypass HGB. Therefore, there is no possibility of liquid back in the compressor 4.

このように本精密空調機は、精密に温度・湿度を制御できる上、複数の蒸発器を設けたり、あるいは、圧縮機４をインバータ制御する必要がないなど設備コストが安い上、熱交換器８により冷媒の過冷却を防止するので、省エネにも役立つ。 As described above, this precision air conditioner can precisely control the temperature and humidity, and has a low equipment cost such as providing a plurality of evaporators or controlling the compressor 4 with an inverter, and the heat exchanger 8. Prevents overcooling of the refrigerant, which is also useful for energy saving.

本発明の好ましい実施例では、圧縮機４の入口の第２目標温度Ｔ２が蒸発器３の入口の第１目標温度Ｔ１と同じ値か、または、第１目標温度Ｔ１よりも低い温度に設定される。
この場合、第１下限値Ｌ１が第２下限値Ｌ２よりも高い温度に設定されているのが更に好ましい。蒸発器３の凍結防止を確実に図るためである。 In a preferred embodiment of the present invention, the second target temperature T2 at the inlet of the compressor 4 is set to the same value as the first target temperature T1 at the inlet of the evaporator 3 or lower than the first target temperature T1. The
In this case, it is more preferable that the first lower limit value L1 is set to a temperature higher than the second lower limit value L2. This is for surely preventing the evaporator 3 from freezing.

本発明の別の好ましい実施例では、第１測定温度Ｓ１が第１下限値Ｌ１よりも低く、かつ、第２測定温度Ｓ２が第２下限値Ｌ２よりも低い場合には、第１測定温度Ｓ１が目標温度Ｔ１に近づくように制御弁７の開度を制御する。
この場合、優先的に蒸発器３の凍結防止が図られる。 In another preferred embodiment of the present invention, when the first measurement temperature S1 is lower than the first lower limit value L1 and the second measurement temperature S2 is lower than the second lower limit value L2, the first measurement temperature S1 Controls the opening of the control valve 7 so as to approach the target temperature T1.
In this case, the evaporator 3 is preferentially prevented from freezing.

本発明の好ましい実施例においては、前記ホットガスバイパスＨＧＢが前記膨張弁２の下流端から蒸発器３の入口までの部位において前記第２導管１２に接続されている。
この場合、ホットガスバイパスＨＧＢからの冷媒が膨張弁２を通ることなく、蒸発器３に流入するので、温度制御の応答が早くなるなど、より効果的である。 In a preferred embodiment of the present invention, the hot gas bypass HGB is connected to the second conduit 12 at a site from the downstream end of the expansion valve 2 to the inlet of the evaporator 3.
In this case, since the refrigerant from the hot gas bypass HGB flows into the evaporator 3 without passing through the expansion valve 2, it is more effective such as quick response of temperature control.

以下、本発明の一実施例を図面にしたがって説明する。
凝縮器１は、図示しない冷却装置の冷却水により冷却される。膨張弁２としてはキャピラリを用いるが電子膨張弁を用いることもできる。 Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
The condenser 1 is cooled by cooling water from a cooling device (not shown). A capillary is used as the expansion valve 2, but an electronic expansion valve can also be used.

ヒータ６は、空気Ａを加熱するものであるが、空気Ａの温度を測定する第３温度センサ（図示せず）の測定値と設定温度との差に応じて、出力が制御手段により制御される。これにより、吹出口３０から吹出す空気の温度が所定温度となるように制御される。 The heater 6 heats the air A. The output is controlled by the control means according to the difference between the measured value of a third temperature sensor (not shown) that measures the temperature of the air A and the set temperature. The Thereby, the temperature of the air which blows off from the blower outlet 30 is controlled so that it may become predetermined temperature.

制御弁７はホットガスバイパスＨＧＢに設けているが、第１導管１１に設けることも可能である。 Although the control valve 7 is provided in the hot gas bypass HGB, it can also be provided in the first conduit 11.

本発明においては、蒸発器３および圧縮機４に流入する冷媒の温度が低下しすぎるのを防止するものであるのに対し、熱交換器８は、ホットガスバイパスＨＧＢから蒸発器３に流入する冷媒を冷却し、一方、圧縮機４に戻る冷媒を昇温させる。そのため、熱交換器８の容量を適切な値に設定する必要がある。熱交換器８の容量は、系に挿入する熱交換器８を順次追加ないし交換し試行錯誤により求める。 In the present invention, the temperature of the refrigerant flowing into the evaporator 3 and the compressor 4 is prevented from excessively decreasing, whereas the heat exchanger 8 flows into the evaporator 3 from the hot gas bypass HGB. The refrigerant is cooled, while the refrigerant returning to the compressor 4 is heated. Therefore, it is necessary to set the capacity of the heat exchanger 8 to an appropriate value. The capacity of the heat exchanger 8 is obtained by trial and error by sequentially adding or replacing the heat exchanger 8 to be inserted into the system.

筐体４１は区画壁４２によって、第１チャンバ４３と第２チャンバ４４とに区画されている。前記第１チャンバ４３には、前記蒸発器３およびファン５が収容されている。一方、第２チャンバ４４には、前記圧縮機４、凝縮器１および水冷式の冷却装置などが収容されている。 The housing 41 is partitioned into a first chamber 43 and a second chamber 44 by a partition wall 42. The first chamber 43 accommodates the evaporator 3 and the fan 5. On the other hand, the second chamber 44 accommodates the compressor 4, the condenser 1, and a water-cooled cooling device.

したがって、ファン５により、外気が、取込孔から第１チャンバ４３内に取り込まれ、蒸発器３を通ると、前記外気が蒸発器３で除湿されると共に冷却される。除湿および冷却された空気は、前記ファン５により筐体４１の吹出口３０から送出される。一方、第２チャンバ４４内に設けた凝縮器１においては、冷媒が圧縮されて高温になるのに対し、冷却水により、凝縮器１を冷やすことで放熱を促して、冷媒の温度を低下させている。 Therefore, when the outside air is taken into the first chamber 43 from the taking-in hole by the fan 5 and passes through the evaporator 3, the outside air is dehumidified and cooled by the evaporator 3. The dehumidified and cooled air is sent out from the outlet 30 of the housing 41 by the fan 5. On the other hand, in the condenser 1 provided in the second chamber 44, the refrigerant is compressed and becomes high temperature, whereas cooling the condenser 1 with cooling water promotes heat radiation and lowers the temperature of the refrigerant. ing.

前記ファン５により送出される空気の流路には、湿度センサ（図示せず）およびヒータ６が設けられている。前記湿度センサは、前記蒸発器３により除湿された空気の湿度を検出する。前記ヒータ６は、前記蒸発器３により冷却された空気を所定の温度に昇温する。前記湿度センサおよびヒータ６を通過した空気は、吹出口３０を通って所定の領域Ｓに排出される。 A humidity sensor (not shown) and a heater 6 are provided in the flow path of the air sent out by the fan 5. The humidity sensor detects the humidity of the air dehumidified by the evaporator 3. The heater 6 raises the temperature of the air cooled by the evaporator 3 to a predetermined temperature. The air that has passed through the humidity sensor and the heater 6 is exhausted to a predetermined region S through the air outlet 30.

前記領域Ｓには、当該領域Ｓの温度Ｔｓを検出するための第３温度センサが設けられている。前記第３温度センサは、検出した温度Ｔｓを温度調節回路（図示せず）に出力する。前記温度調節回路は、前記第３温度センサの検出値Ｔｓに基づいて、前記領域Ｓの温度Ｔｓが設定値となるように、前記ヒータ６の発熱量を制御する。すなわち、前記領域Ｓの温度Ｔｓが設定値よりも高い場合には、前記ヒータ６の発熱量を小さくし、一方、前記領域Ｓの温度Ｔｓが設定値よりも低い場合には、前記ヒータ６の発熱量を大きくする。 In the area S, a third temperature sensor for detecting the temperature Ts of the area S is provided. The third temperature sensor outputs the detected temperature Ts to a temperature adjustment circuit (not shown). The temperature adjusting circuit controls the amount of heat generated by the heater 6 based on the detection value Ts of the third temperature sensor so that the temperature Ts of the region S becomes a set value. That is, when the temperature Ts of the region S is higher than a set value, the amount of heat generated by the heater 6 is reduced. On the other hand, when the temperature Ts of the region S is lower than the set value, the heater 6 Increase calorific value.

前記第１温度センサ２１は、第２導管１２の膨張弁２よりも下流であってホットガスバイパスＨＧＢとの合流点Ｏから蒸発器３の入口部分までの間に設けられ、例えば蒸発器３の入口近傍に設けられる。前記蒸発器３の入口温度としては、たとえば、第１目標温度Ｔ１が−１℃に設定され、第１下限値Ｌ１が−２℃に設定される。 The first temperature sensor 21 is provided downstream from the expansion valve 2 of the second conduit 12 and between the junction O with the hot gas bypass HGB and the inlet portion of the evaporator 3. Provided near the entrance. As the inlet temperature of the evaporator 3, for example, the first target temperature T1 is set to -1 ° C, and the first lower limit L1 is set to -2 ° C.

前記第２温度センサ２２は例えば圧縮機４の吸入口近傍に設けられる。前記圧縮機４の吸入口温度としては、たとえば、第２目標温度Ｔ２が−１℃に設定され第２下限値Ｌ２が−３℃に設定される。 The second temperature sensor 22 is provided, for example, in the vicinity of the suction port of the compressor 4. As the inlet temperature of the compressor 4, for example, the second target temperature T2 is set to -1 ° C, and the second lower limit L2 is set to -3 ° C.

つぎに、本精密空調機の運転について説明する。
本精密空調機の運転を開始すると、図２のように、冷媒の温度が徐々に下る。運転当初は、第１測定温度Ｓ１が−２℃以上で、かつ、第２測定温度Ｓ２が−３℃以上であり、この場合、ホットガスバイパスＨＧＢの制御弁７は湿度制御のために機能する。
蒸発器３の第１測定温度Ｓ１が第１目標温度Ｔ１（−１℃）以上で、かつ、圧縮機４の第２測定温度Ｓ２が第２目標温度Ｔ２（−３℃）以上である場合、湿度制御をホットガスバイパスＨＧＢを用いて行う。
すなわち、吹出口３０の近傍に設けた湿度センサ（図示せず）の測定値Ｓ１０が湿度設定値Ｔ１０に比べ高い場合には、制御弁７を閉じて蒸発器３の温度を下げると共に吹出口３０の空気Ａの湿度を下げる。
一方、前記湿度センサ（図示せず）の測定値Ｓ１０が湿度設定値Ｔ１０に比べ低い場合には、制御弁７を開いて蒸発器３の温度を上げると共に吹出口３０の空気Ａの湿度を上げる。なお、蒸発器３の第１測定温度Ｓ１が第１目標温度Ｔ１（−１℃）よりも低い場合や、圧縮機４の第２測定温度Ｓ２が第２目標温度Ｔ２（−３℃）よりも低い場合には、前記湿度制御を行わない。 Next, the operation of this precision air conditioner will be described.
When the operation of the precision air conditioner is started, the temperature of the refrigerant gradually decreases as shown in FIG. At the beginning of operation, the first measurement temperature S1 is −2 ° C. or more and the second measurement temperature S2 is −3 ° C. or more. In this case, the control valve 7 of the hot gas bypass HGB functions for humidity control. .
When the first measured temperature S1 of the evaporator 3 is equal to or higher than the first target temperature T1 (−1 ° C.) and the second measured temperature S2 of the compressor 4 is equal to or higher than the second target temperature T2 (−3 ° C.), Humidity control is performed using a hot gas bypass HGB.
That is, when the measured value S10 of a humidity sensor (not shown) provided in the vicinity of the blower outlet 30 is higher than the humidity set value T10, the control valve 7 is closed to lower the temperature of the evaporator 3 and the blower outlet 30. Reduce the humidity of air A.
On the other hand, when the measured value S10 of the humidity sensor (not shown) is lower than the humidity set value T10, the control valve 7 is opened to raise the temperature of the evaporator 3 and raise the humidity of the air A at the outlet 30. . In addition, when the 1st measured temperature S1 of the evaporator 3 is lower than 1st target temperature T1 (-1 degreeC), or the 2nd measured temperature S2 of the compressor 4 is 2nd target temperature T2 (-3 degreeC). When it is low, the humidity control is not performed.

図２に示すように、やがて、第１測定温度Ｓ１が−２℃（第１下限値Ｌ１）になると、制御手段９が制御弁７を開弁し、第１測定温度Ｓ１が第１目標温度Ｔ１（−１℃）となるように制御弁７の開度を制御する。
この場合の制御方法としては、例えば、第１目標温度Ｔ１と第１測定温度Ｓ１との温度差ΔＴに前記制御弁７の開度を比例させる比例制御を採用することができる。 As shown in FIG. 2, when the first measured temperature S1 eventually reaches −2 ° C. (first lower limit L1), the control means 9 opens the control valve 7, and the first measured temperature S1 becomes the first target temperature. The opening degree of the control valve 7 is controlled to be T1 (−1 ° C.).
As a control method in this case, for example, proportional control in which the opening degree of the control valve 7 is proportional to the temperature difference ΔT between the first target temperature T1 and the first measured temperature S1 can be employed.

一方、第２測定温度Ｓ２が−３℃（第２下限値Ｌ２）以下になった場合も、制御手段９が制御弁７を開弁し、第２測定温度Ｓ２が第２目標温度Ｔ２（−１℃）となるように制御弁７の開度を制御する。 On the other hand, also when the second measured temperature S2 becomes −3 ° C. (second lower limit L2) or less, the control means 9 opens the control valve 7, and the second measured temperature S2 becomes the second target temperature T2 (− The opening degree of the control valve 7 is controlled to be 1 ° C.

前記第１測定温度Ｓ１が−２℃（第１下限値Ｌ１）以下で、かつ、前記第２測定温度Ｓ２が−３℃（第２下限値Ｌ２）以下である場合には、第２測定温度Ｓ２を無視し、第１測定温度Ｓ１が第１目標温度Ｔ１（−１℃）となるように制御弁７の開度を制御する。 When the first measurement temperature S1 is −2 ° C. (first lower limit L1) or lower and the second measurement temperature S2 is −3 ° C. (second lower limit L2) or lower, the second measurement temperature S2 is ignored and the opening degree of the control valve 7 is controlled so that the first measured temperature S1 becomes the first target temperature T1 (−1 ° C.).

なお、本発明の精密空調機において、ヒータ６の下部にはドレンパンを設置し、水漏れを防止してもよい。
また、本発明の精密空調機の底面のパネルを全面にわたってドレンパンとし、水漏れを防止してもよい。
さらに、冷却水の水温流量計を設置し、凝縮器１に流入する水温および水量を操作表示パネルに表示してもよい。 In the precision air conditioner of the present invention, a drain pan may be installed under the heater 6 to prevent water leakage.
In addition, the bottom panel of the precision air conditioner of the present invention may be a drain pan over the entire surface to prevent water leakage.
Furthermore, a water temperature flow meter for cooling water may be installed, and the temperature and amount of water flowing into the condenser 1 may be displayed on the operation display panel.

図３は他の例を示す。
この図に示すように、ホットガスバイパスＨＧＢを膨張弁２の上流の点Ｏに接続し、前記ホットガスバイパスＨＧＢの冷媒を膨張弁２を介して蒸発器３に導入してもよい。
また、図１において、ホットガスバイパスＨＧＢの熱交換器８の下流に別の膨張弁を設けた場合も本発明の範囲に含まれる。 FIG. 3 shows another example.
As shown in this figure, the hot gas bypass HGB may be connected to a point O upstream of the expansion valve 2, and the refrigerant of the hot gas bypass HGB may be introduced into the evaporator 3 via the expansion valve 2.
Moreover, in FIG. 1, the case where another expansion valve is provided downstream of the heat exchanger 8 of the hot gas bypass HGB is also included in the scope of the present invention.

本発明は工業用の精密空調機に利用することができる。 The present invention can be used for industrial precision air conditioners.

本発明の精密空調機の一実施例を示す概略構成図である。It is a schematic block diagram which shows one Example of the precision air conditioner of this invention. 制御方法を示す特性図である。It is a characteristic view which shows a control method. 他の例を示す精密空調機の概略構成図である。It is a schematic block diagram of the precision air conditioning machine which shows another example.

符号の説明Explanation of symbols

１：凝縮器
２：膨張弁
３：蒸発器
４：圧縮機
５：ファン
６：ヒータ
７：制御弁
８：熱交換器
９：制御手段
１１：第１導管
１２：第２導管
２１：第１温度センサ
２２：第２温度センサ
ＨＧＢ：ホットガスバイパス 1: Condenser 2: Expansion valve 3: Evaporator 4: Compressor 5: Fan 6: Heater 7: Control valve 8: Heat exchanger 9: Control means 11: First conduit 12: Second conduit 21: First temperature Sensor 22: Second temperature sensor HGB: Hot gas bypass

Claims

冷媒を冷却するための凝縮器１と、冷媒に流れ抵抗を与えるための膨張弁２と、冷媒で周囲の空気を冷却するための蒸発器３と、前記蒸発器３から凝縮器１および膨張弁２を通って再び蒸発器３に冷媒が循環するように蒸発器３からの冷媒を凝縮器１に圧送する圧縮機４と、前記蒸発器３で除湿すると共に冷却した空気Ａを送風するファン５と、前記空気Ａを加熱して所定の温度まで昇温させるヒータ６とを備えた精密空調機において、
前記圧縮機４から凝縮器１に冷媒を導く第１導管１１と、前記凝縮器１から前記蒸発器３に冷媒を導く第２導管１２とを連ねて前記圧縮機４で圧縮された冷媒を前記蒸発器３に導くホットガスバイパスＨＧＢと、
前記ホットガスバイパスＨＧＢの流量を制御する制御弁７と、
前記ホットガスバイパスＨＧＢを流れる冷媒の熱で前記蒸発器３から前記圧縮機４に戻る冷媒を昇温させる熱交換器８と、
前記膨張弁２の出口から前記蒸発器３の入口までにおける任意の部位における冷媒の温度を測定する第１温度センサ２１と、
前記熱交換器８の出口から前記圧縮機４の入口までの任意の部位における冷媒の温度を測定する第２温度センサ２２と、
前記蒸発器３の入口温度である第１目標温度Ｔ１と、前記蒸発器３の入口温度の第１下限値Ｌ１と、前記圧縮機４の入口温度である第２目標温度Ｔ２と、前記圧縮機４の入口温度の第２下限値Ｌ２とを記憶する制御手段９とを備え、
前記第１および第２目標温度Ｔ１、Ｔ２が氷点下に設定され、かつ、前記第１および第２下限値Ｌ１、Ｌ２が前記第１および第２目標温度Ｔ１、Ｔ２よりも低い温度に設定され、
前記第１温度センサ２１により第１測定温度Ｓ１が前記第１下限値Ｌ１よりも低くなると当該第１測定温度Ｓ１が前記第１目標温度Ｔ１に近づくように、前記制御弁７の開度を制御してホットガスバイパスＨＧＢの流量が大きくなるように、
かつ、前記第２温度センサ２２による第２測定温度Ｓ２が前記第２下限値Ｌ２よりも低くなると当該第２測定温度Ｓ２が前記第２目標温度Ｔ２に近づくように、前記制御弁７の開度を制御してホットガスバイパスＨＧＢの流量が大きくなるように前記制御手段９が制御弁７の開度を制御する精密空調機。 A condenser 1 for cooling the refrigerant, an expansion valve 2 for imparting flow resistance to the refrigerant, an evaporator 3 for cooling the surrounding air with the refrigerant, the condenser 1 and the expansion valve from the evaporator 3 2, the compressor 4 that pumps the refrigerant from the evaporator 3 to the condenser 1 so that the refrigerant circulates again to the evaporator 3, and the fan 5 that dehumidifies the evaporator 3 and blows the cooled air A And a precision air conditioner provided with a heater 6 that heats the air A and raises the temperature to a predetermined temperature.
The refrigerant compressed by the compressor 4 is connected to the first conduit 11 that guides the refrigerant from the compressor 4 to the condenser 1 and the second conduit 12 that guides the refrigerant from the condenser 1 to the evaporator 3. A hot gas bypass HGB leading to the evaporator 3;
A control valve 7 for controlling the flow rate of the hot gas bypass HGB;
A heat exchanger 8 that raises the temperature of the refrigerant returning from the evaporator 3 to the compressor 4 by the heat of the refrigerant flowing through the hot gas bypass HGB;
A first temperature sensor 21 that measures the temperature of the refrigerant at an arbitrary position from the outlet of the expansion valve 2 to the inlet of the evaporator 3;
A second temperature sensor 22 that measures the temperature of the refrigerant at any part from the outlet of the heat exchanger 8 to the inlet of the compressor 4;
The first target temperature T1 that is the inlet temperature of the evaporator 3, the first lower limit value L1 of the inlet temperature of the evaporator 3, the second target temperature T2 that is the inlet temperature of the compressor 4, and the compressor Control means 9 for storing the second lower limit value L2 of the inlet temperature of 4,
The first and second target temperatures T1, T2 are set below freezing point, and the first and second lower limit values L1, L2 are set to temperatures lower than the first and second target temperatures T1, T2.
When the first measured temperature S1 becomes lower than the first lower limit L1 by the first temperature sensor 21, the opening degree of the control valve 7 is controlled so that the first measured temperature S1 approaches the first target temperature T1. So that the flow rate of the hot gas bypass HGB is increased.
In addition, when the second measured temperature S2 by the second temperature sensor 22 becomes lower than the second lower limit value L2, the opening of the control valve 7 is adjusted so that the second measured temperature S2 approaches the second target temperature T2. The precision air conditioner in which the control means 9 controls the opening degree of the control valve 7 so that the flow rate of the hot gas bypass HGB is increased by controlling the flow rate.

請求項１において、前記第２目標温度Ｔ２が第１目標温度Ｔ１と同じ値か、または、第１目標温度Ｔ１よりも低い温度に設定されている精密空調機。 The precision air conditioner according to claim 1, wherein the second target temperature T2 is set to the same value as the first target temperature T1 or a temperature lower than the first target temperature T1.

請求項１もしくは２において、前記第１下限値Ｌ１が前記第２下限値Ｌ２よりも高い温度に設定されている精密空調機。 The precision air conditioner according to claim 1 or 2, wherein the first lower limit value L1 is set to a temperature higher than the second lower limit value L2.

請求項１、２もしくは３において、前記第１測定温度Ｓ１が第１下限値Ｌ１よりも低く、かつ、前記第２測定温度Ｓ２が第２下限値Ｌ２よりも低い場合には、前記第１測定温度Ｓ１が前記目標温度Ｔ１に近づくように前記制御弁７の開度を制御することを特徴とする精密空調機。 In Claim 1, 2, or 3, when said 1st measurement temperature S1 is lower than 1st lower limit L1, and said 2nd measurement temperature S2 is lower than 2nd lower limit L2, said 1st measurement A precision air conditioner that controls the opening degree of the control valve 7 so that the temperature S1 approaches the target temperature T1.

請求項１〜４のいずれか１項において、前記ホットガスバイパスＨＧＢが前記膨張弁２の下流端から蒸発器３の入口までの部位において前記第２導管１２に接続されている精密空調機。 The precision air conditioner according to any one of claims 1 to 4, wherein the hot gas bypass HGB is connected to the second conduit 12 at a portion from a downstream end of the expansion valve 2 to an inlet of the evaporator 3.