JP4086575B2 - Heat transfer device and operation method thereof - Google Patents

Description

蒸発器９に寝込んだ冷媒が追い出されたと推定し（Ｓ３）、冷媒調整弁１１を徐々に開放する（Ｓ５）。（１）式が成立しない場合、冷媒調整弁１１は全閉に維持される（Ｓ４）。冷媒調整弁１１が開放されると（Ｓ５）、この冷媒調整弁１１の弁開度は、Ｅ３−Ｅ１≧３℃を保つように制御される（Ｓ６）。
【００３０】
この冷媒調整弁１１は、吹出し空気温度Ｔｂと、予め設定された吹出し目標空気温度との温度差によって開閉される。具体的には、吹出し空気温度Ｔｂが予め設定された吹出し目標空気温度を下回った後、一定時間が経過したか否かが判定され（Ｓ７）、一定時間が経過した場合、冷媒調整弁１１が全閉にされる（Ｓ８）。吹出し空気温度ＴｂはセンサＴ２によって検出される。
【００３１】
冷媒調整弁１１が全閉にされた後（Ｓ８）、蒸発器９を再起動させる場合には、図２の各ステップが繰り返される。
【００３２】
いずれかの蒸発器９の運転が開始される場合、運転を停止中の蒸発器９が存在すれば、この停止中の蒸発器９に対しても冷媒追い出し制御が実行される。この場合、冷媒調整弁１１を全閉にした状態で、対応した送風機１３を一定時間の間、駆動することにより行われる。
【００３３】
本実施形態では、いずれかの蒸発器９の運転が開始される場合、停止中の蒸発器９を含めて、すべての蒸発器９内に滞留する冷媒が冷媒ガス本管１９Ａ内に追い出されるため、いわゆるガス欠状態が解消される。
【００３４】
また、冷媒液管の冷媒量が充足し、各蒸発器９に冷媒をほぼ均等に分流させることができる等の効果が得られる。
【００３５】
上記の構成によれば、大型の冷媒対水熱交換器５が必要な場合であっても、この１台の冷媒対水熱交換器５に対して複数の室内機７を備えたことから、室内機７を小型化でき、狭い天井裏１０にも設置可能となる。さらに、室内機７が小型化されたことで、エレベータでの搬入が可能となり、ビルの室内への室内機７の搬入が容易になる。
【００３６】
また、夫々の室内機７は、室内機７内の蒸発器９の吸込口が略同一の高さになるように設置されたことから、夫々の室内機７に流れ込む液冷媒の量が略均等になり、いずれの室内機７においても熱交換（冷房）能力が均等になるので、室内を均等に冷房できる。
【００３７】
以上、一実施形態に基づいて本発明を説明したが、本発明はこれに限定されるものではない。
【００３８】
上記実施形態において、夫々の室内機７は、天井裏１０に略同一の高さに設置された場合を説明したが、図示しないが例えば図１において、左側の室内機７が同一室内の熱負荷の大きい側に設置される室内機であり、他の室内機７が熱負荷の小さい側に設置される室内機であって、熱負荷の大きい側に設置される室内機は、熱負荷の小さい側に設置される室内機よりも低い位置で且つ凝縮器として機能する冷媒対水熱交換器５寄りに据え付けるようにすれば、熱負荷の大きい側の室内機に多量の液冷媒が流れ、冷房能力が上昇するため、理想的な冷房状態を得ることができる。
【００３９】
上記実施形態では、室内機７を、建屋の天井裏１０に設置しているが、これに限定されず、例えば、「フリーアクセスフロア」タイプの建屋にあっては、床下の空間内に室内機７を設置し、この室内機７の吹出口を、床面に形成された吹出口に接続し、この床面の吹出口を通じて、調温空気を被調和室内に吹き出すように構成してもよい。
【００４０】
【発明の効果】
本発明では、蒸発器の運転が開始される場合、蒸発器内に滞留する冷媒が冷媒ガス管内に追い出されるため、いわゆるガス欠状態が解消されると共に、冷媒液管の冷媒量が充足するため、各蒸発器に冷媒をほぼ均等に分流させることができる、等の効果が得られる。
【図面の簡単な説明】
【図１】本発明に係る熱移動装置の一実施の形態を示す回路図である。
【図２】本発明に係る熱移動装置の一実施の形態を示す制御フロー図である。
【符号の説明】
１ 熱移動装置
５ 冷媒対水熱交換器（凝縮器）
７ 室内機
９ 蒸発器
１１ 冷媒調整弁（制御弁）
１７ 冷媒液管
１９ 冷媒ガス管
３１ コントローラ（制御手段）[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a refrigerant natural circulation heat transfer device and an operation method.
[0002]
[Prior art]
In general, a heat transfer device using a heat pipe system in which a refrigerant is naturally circulated by changing a gas-liquid phase in a cycle is known. This type includes, for example, one condenser and one evaporator at a lower position than the condenser, and the refrigerant liquid pipe and the gas-phase refrigerant flow between them. A natural circulation cycle is formed by connecting with the rising refrigerant gas pipe. A refrigerant is enclosed in the natural circulation cycle. The evaporator is housed in an indoor unit, which cools the room. In the above configuration, in recent years, it has been proposed that a condenser and a plurality of evaporators are provided and these evaporators are separately installed in a plurality of indoor units.
[0003]
[Problems to be solved by the invention]
However, when the evaporators are separately installed in the plurality of indoor units, there is a problem that the refrigerant stagnates in the evaporator that has stopped operating, and a so-called gas shortage occurs in the operating evaporator. In addition, if the amount of refrigerant on the refrigerant liquid pipe side is insufficient, there is a problem that the refrigerant cannot be divided almost uniformly into each evaporator.
[0004]
Accordingly, an object of the present invention is to solve the problems of the prior art described above, heat transfer that does not cause out of gas in the operating evaporator, and allows the refrigerant to be divided almost evenly into each evaporator. It is to provide an apparatus and an operation method.
[0005]
[Means for Solving the Problems]
The invention according to claim 1 includes a condenser and a plurality of evaporators, and a natural liquid circulation cycle is formed by connecting a refrigerant liquid pipe and a refrigerant gas pipe therebetween, and the refrigerant is enclosed in the natural circulation cycle. The heat transfer device is provided with a control valve upstream of the plurality of evaporators, and has a control means for controlling each control valve at the start of operation. The control means fully closes the control valve of the evaporator to start operation. The fan is driven .
[0007]
According to a second aspect of the present invention, in the first aspect of the present invention, the control means fully closes the control valve of the evaporator to start operation, drives the blower, sucks the air temperature, the refrigerant inlet temperature, and the refrigerant When the comparison temperature difference using the outlet temperature reaches within a predetermined temperature, the control valve is gradually opened.
[0008]
According to a third aspect of the present invention, in the apparatus according to the first or second aspect , when there is an evaporator whose operation is stopped, the control means is configured to perform a predetermined time after any of the evaporators starts operating. The control valve of the evaporator during operation stop is fully closed to drive the blower during operation stop.
[0009]
According to a fourth aspect of the present invention, in the apparatus according to any one of the first to third aspects, the air conditioning of the building is performed by being installed on a ceiling or a floor portion of the building.
[0010]
The invention according to claim 5 includes a condenser and a plurality of evaporators, and a natural circulation cycle is formed by connecting a refrigerant liquid pipe and a refrigerant gas pipe therebetween, and the refrigerant is enclosed in the natural circulation cycle. In the operation method of the heat transfer apparatus, a control valve is provided upstream of the plurality of evaporators , each control valve is controlled at the start of operation, the control valve of the evaporator to be started is fully closed, and the blower is driven. It is characterized by that.
[0012]
The invention according to claim 6 is the apparatus according to claim 5 , wherein the control valve of the evaporator to be started is fully closed, the blower is driven, and the intake air temperature, the refrigerant inlet temperature, and the refrigerant outlet temperature are used. The control valve is gradually opened when the comparison temperature difference reaches within a predetermined temperature.
[0013]
The invention according to claim 7 is the invention according to claim 5 or 6 , wherein when there is an evaporator whose operation is stopped, the evaporation during operation is stopped for a predetermined time after any evaporator starts operation. The control valve of the fan is fully closed to drive the blower that is stopped.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
[0015]
In FIG. 1, reference numeral 1 denotes a heat transfer device. The heat transfer device 1 includes a refrigerator 3 that cools water, a refrigerant-to-water heat exchanger 5 that functions as a condenser, and a plurality of indoor units 7. The indoor unit 7 houses an evaporator 9, a refrigerant adjustment valve (control valve) 11, and a blower 13 for blowing air into the room. The refrigerant | coolant versus water heat exchanger 5 is installed in high places, such as the rooftop of a building, for example. The indoor unit 7 is installed on the ceiling 10 of the ceiling board 8 in the building room, which is lower than the refrigerant-to-water heat exchanger 5, so that the suction ports of the evaporator 9 have substantially the same height. The ceiling plate 8 has a discharge port 12 corresponding to each indoor unit 7. The refrigerator 3 is, for example, an absorption refrigerator, and the refrigerator 3 and the refrigerant-to-water heat exchanger 5 are connected in a loop by a water pipe 15.
[0016]
The indoor unit 7 is connected to the refrigerant-to-water heat exchanger 5 through a refrigerant liquid pipe 17 and a refrigerant gas pipe 19 to form a natural circulation cycle. And the refrigerant | coolant is enclosed inside this natural circulation cycle.
[0017]
The refrigerant liquid pipe 17 includes a refrigerant liquid main pipe 17A and a plurality of refrigerant liquid branch pipes 17B connected to the refrigerant liquid main pipe 17A. The refrigerant gas pipe 19 includes a refrigerant gas main pipe 19A and a plurality of refrigerant gas pipes 19B connected to the refrigerant gas main pipe 19A. The refrigerant liquid main pipe 17A and the refrigerant gas main pipe 19A are connected to the refrigerant-to-water heat exchanger 5, and each refrigerant liquid branch pipe 17B and each refrigerant gas branch pipe 19B are connected to the evaporator 9 of each indoor unit 7. Due to these connection relationships, the evaporators 9 are parallel to each other. The refrigerant adjustment valve 11 is connected to the refrigerant liquid branch pipe 17B. Further, a booster pump 21 for forcibly circulating the refrigerant is connected to the refrigerant liquid main pipe 17A.
[0018]
Here, the refrigerant liquid pipe connection point R between the refrigerant liquid main pipe 17A and the refrigerant liquid branch pipe 17B and the refrigerant gas pipe connection point S between the refrigerant gas main pipe 19A and the refrigerant gas pipe 19B are located higher than the evaporator 18. To position. It is sufficient that at least the refrigerant gas pipe connection point S is located higher than the evaporator 18.
[0019]
Next, the operation of the heat transfer apparatus 1 will be described.
[0020]
When the refrigerator 3 is operated, cold water at 5 ° C., for example, is given to the refrigerant-to-water heat exchanger 5. Then, the refrigerant condenses in the refrigerant-to-water heat exchanger 5, becomes a liquid refrigerant having a large specific gravity, and flows through the refrigerant liquid main pipe 17 </ b> A of the refrigerant liquid pipe 17. The liquid refrigerant reaching the refrigerant liquid pipe connection point R of the refrigerant liquid main pipe 17A flows through the refrigerant liquid branch pipes 17B from the high place to the low place by its own weight, and then flows into the indoor units 7.
[0021]
The liquid refrigerant whose refrigerant amount is appropriately adjusted by the refrigerant adjustment valve 11 of the indoor unit 7 flows into the evaporator 9, where the liquid refrigerant evaporates at an evaporation temperature of 12 ° C., for example. In this process, the liquid refrigerant becomes a gas refrigerant having an extremely small specific gravity. Because of the light weight of the gas refrigerant, the refrigerant flows through each refrigerant gas branch pipe 19B from the low place to the high place and passes through each refrigerant gas pipe connection point S. It flows into the refrigerant gas main pipe 19 </ b> A and is returned to the refrigerant-to-water heat exchanger 5. That is, in this system, the refrigerant is naturally circulated by changing the gas-liquid phase within the natural circulation cycle.
[0022]
The indoor air passes through the ventilation openings 23 provided in the ceiling plate 8, is sucked into each indoor unit 7, is cooled by the evaporator 9, and is blown into the room from the discharge port 12 by the blower 13. Is done.
[0023]
In such a natural circulation system, the refrigerant in the cycle is naturally circulated according to the difference in specific gravity between the liquid refrigerant and the gas refrigerant. Therefore, a circulation pump or the like is unnecessary in the original case. However, when constructing this natural circulation system, a booster pump 21 is used as an example when it is difficult to make a drop between the refrigerant-to-water heat exchanger 5 and the evaporator 9.
[0024]
In the present embodiment, as described above, the refrigerant adjustment valves (control valves) 11 are provided upstream of the plurality of evaporators 9, respectively, and a controller (control means) 31 that controls each refrigerant adjustment valve 11 at the start of system operation. Is provided.
[0025]
FIG. 2 shows a control flow by the controller 31.
[0026]
This control flow is a flow focusing on one evaporator 9. When starting the operation of the system, first, the refrigerant adjustment valve 11 of the evaporator 9 to be started is fully closed, and the corresponding blower 13 is driven (S1). The process here is a process in which the liquid refrigerant that has fallen into the evaporator 9 is vaporized and the gas refrigerant is expelled from the evaporator 9 to the refrigerant gas branch 19B side. It is determined whether or not this process has been performed for a certain period of time (S2).
[0027]
In S <b> 3, it is determined whether or not the refrigerant stagnated in the evaporator 9 that starts operation has been driven out to the refrigerant gas branch 19 </ b> B side.
[0028]
When the refrigerant adjusting valve 11 is fully closed and the blower 13 is driven without flowing the refrigerant, the refrigerant that has fallen into the evaporator 9 is gasified by the heat radiation action of the blower 13 and is completely transferred to the refrigerant gas branch 19B side. Get kicked out. In this case, finally, the intake air temperature Ta, the refrigerant inlet temperature E1, and the refrigerant outlet temperature E3 all become equal. The intake air temperature Ta is detected by the sensor T1, the refrigerant inlet temperature E1 is detected by the sensor T3, and the refrigerant outlet temperature E3 is detected by the sensor T4.
[0029]
In S3, the intake air temperature Ta, the refrigerant inlet temperature E1, and the refrigerant outlet temperature E3 are always detected in the processes of S1 and S2, and the detected intake air temperature Ta, refrigerant inlet temperature E1, and refrigerant outlet temperature E3 are detected. When the maximum value Max (Ta, E1, E3) is compared with any minimum value Min (Ta, E1, E3), and the temperature difference is within a certain value α, When the comparison temperature difference using the intake air temperature Ta, the refrigerant inlet temperature E1, and the refrigerant outlet temperature E3 reaches within a predetermined temperature α, and the following equation (1) is satisfied:

It is estimated that the refrigerant that has fallen into the evaporator 9 has been expelled (S3), and the refrigerant adjustment valve 11 is gradually opened (S5). If the expression (1) is not satisfied, the refrigerant adjustment valve 11 is kept fully closed (S4). When the refrigerant adjustment valve 11 is opened (S5), the opening degree of the refrigerant adjustment valve 11 is controlled so as to maintain E3-E1 ≧ 3 ° C. (S6).
[0030]
The refrigerant regulating valve 11 is opened and closed by a temperature difference between the blown air temperature Tb and a preset blow target air temperature. Specifically, after the blown air temperature Tb falls below the preset blow target air temperature, it is determined whether or not a certain time has passed (S7). Fully closed (S8). The blown air temperature Tb is detected by the sensor T2.
[0031]
After the refrigerant regulating valve 11 is fully closed (S8), when the evaporator 9 is restarted, each step of FIG. 2 is repeated.
[0032]
When the operation of any of the evaporators 9 is started, if there is an evaporator 9 whose operation is stopped, the refrigerant discharge control is also executed for the stopped evaporator 9. In this case, it is performed by driving the corresponding blower 13 for a certain period of time with the refrigerant adjustment valve 11 fully closed.
[0033]
In the present embodiment, when any of the evaporators 9 is started, the refrigerant staying in all the evaporators 9 including the stopped evaporators 9 is expelled into the refrigerant gas main pipe 19A. The so-called out-of-gas condition is eliminated.
[0034]
Further, the refrigerant amount in the refrigerant liquid pipe is satisfied, and an effect that the refrigerant can be divided into the respective evaporators 9 almost uniformly is obtained.
[0035]
According to the above configuration, even when a large refrigerant-to-water heat exchanger 5 is required, a plurality of indoor units 7 are provided for the one refrigerant-to-water heat exchanger 5, The indoor unit 7 can be reduced in size and can be installed in a narrow ceiling 10. Furthermore, since the indoor unit 7 is downsized, it can be carried in by an elevator, and the indoor unit 7 can be easily carried into the building.
[0036]
In addition, since each indoor unit 7 is installed so that the suction ports of the evaporator 9 in the indoor unit 7 have substantially the same height, the amount of liquid refrigerant flowing into each indoor unit 7 is substantially equal. Thus, since the heat exchange (cooling) capacity is equalized in any of the indoor units 7, the room can be evenly cooled.
[0037]
As mentioned above, although this invention was demonstrated based on one Embodiment, this invention is not limited to this.
[0038]
In the above embodiment, the case where each indoor unit 7 is installed at substantially the same height on the ceiling 10 has been described. However, although not illustrated, for example, in FIG. Indoor unit installed on the side with a large heat load, the other indoor unit 7 is installed on the side with a small heat load, and the indoor unit installed on the side with a large heat load has a small heat load If the refrigerant is installed at a position lower than the indoor unit installed on the side and close to the refrigerant-to-water heat exchanger 5 functioning as a condenser, a large amount of liquid refrigerant flows into the indoor unit on the side with a large heat load, Since the capacity increases, an ideal cooling state can be obtained.
[0039]
In the above embodiment, the indoor unit 7 is installed on the ceiling 10 of the building. However, the present invention is not limited to this. For example, in a “free access floor” type building, the indoor unit 7 is located in the space under the floor. 7 may be installed, and the outlet of the indoor unit 7 may be connected to the outlet formed on the floor, and the temperature-controlled air may be blown out into the conditioned room through the outlet on the floor. .
[0040]
【The invention's effect】
In the present invention, when the operation of the evaporator is started, the refrigerant staying in the evaporator is expelled into the refrigerant gas pipe, so that the so-called out-of-gas condition is eliminated and the refrigerant amount in the refrigerant liquid pipe is satisfied. Thus, it is possible to obtain an effect such that the refrigerant can be divided almost uniformly into each evaporator.
[Brief description of the drawings]
FIG. 1 is a circuit diagram showing an embodiment of a heat transfer device according to the present invention.
FIG. 2 is a control flow diagram showing an embodiment of a heat transfer device according to the present invention.
[Explanation of symbols]
1 Heat transfer device 5 Refrigerant to water heat exchanger (condenser)
7 Indoor unit 9 Evaporator 11 Refrigerant adjustment valve (control valve)
17 Refrigerant liquid pipe 19 Refrigerant gas pipe 31 Controller (control means)

Claims (7)

In a heat transfer device that includes a condenser and a plurality of evaporators, connects between them by a refrigerant liquid pipe and a refrigerant gas pipe to form a natural circulation cycle, and encloses the refrigerant in the natural circulation cycle,
A control valve is provided upstream of each of the plurality of evaporators, and control means for controlling each control valve at the start of operation is provided . The control means fully closes the control valve of the evaporator to start operation and drives the blower. A heat transfer device characterized by the above. The control means fully closes the control valve of the evaporator to start operation, drives the blower, and the comparison temperature difference using the intake air temperature, the refrigerant inlet temperature, and the refrigerant outlet temperature has reached within a predetermined temperature. The heat transfer device according to claim 1 , wherein the control valve is gradually opened . When there is an evaporator whose operation is stopped, the control means fully closes the control valve of the evaporator whose operation has been stopped for a predetermined time after any of the evaporators has started operation. The heat transfer device according to claim 1 or 2 , wherein the blower is driven . The heat transfer device according to any one of claims 1 to 3, wherein the heat transfer device is installed on a ceiling or a floor portion of the building and performs air conditioning of the building . In a method of operating a heat transfer apparatus comprising a condenser and a plurality of evaporators, connecting a refrigerant liquid pipe and a refrigerant gas pipe between them to form a natural circulation cycle, and enclosing the refrigerant in the natural circulation cycle ,
A heat transfer device comprising a control valve upstream of each of the plurality of evaporators, controlling each control valve at the start of operation, fully closing the control valve of the evaporator to start operation, and driving a blower how to drive. When the control valve of the evaporator to be started is fully closed, the blower is driven, and the comparison temperature difference using the intake air temperature, the refrigerant inlet temperature, and the refrigerant outlet temperature reaches within a predetermined temperature, the control valve 6. The operation method according to claim 5 , wherein the is gradually opened . When there is a stopped evaporator, after any of the evaporators starts operation, the control valve of the stopped evaporator is fully closed for a predetermined time, and the stopped blower is driven. The operation method according to claim 5 or 6, wherein

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