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JP2019020061A - Air conditioner - Google Patents

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JP2019020061A
JP2019020061A JP2017139613A JP2017139613A JP2019020061A JP 2019020061 A JP2019020061 A JP 2019020061A JP 2017139613 A JP2017139613 A JP 2017139613A JP 2017139613 A JP2017139613 A JP 2017139613A JP 2019020061 A JP2019020061 A JP 2019020061A
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temperature
defrosting operation
indoor
outdoor
outdoor heat
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JP7009808B2 (en
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英司 滝
Hideji Taki
英司 滝
前田 訓孝
Kunitaka Maeda
訓孝 前田
康裕 落合
Yasuhiro Ochiai
康裕 落合
芳剛 佐藤
Yoshitake Sato
芳剛 佐藤
孝行 ▲高▼橋
孝行 ▲高▼橋
Takayuki Takahashi
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Fujitsu General Ltd
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    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02EREDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10Energy storage using batteries

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Abstract

【課題】暖房運転時に室外熱交換器での着霜量に応じた適切な除霜運転が行える空気調和装置を提供する。【解決手段】暖房運転を中断して除霜運転を行うとき、CPU210は、運転室内機台数Dを読み出すとともに、外気温度Toを取り込む。具体的には、CPU210は、外気温度センサ38で検出した温度をセンサ入力部240を介して取り込み、これら運転室内機台数Dと外気温度Toを用い除霜運転終了条件テーブル300を参照して除霜運転終了温度Teを抽出する。その後、CPU210は除霜運転を開始し、室外熱交温度Tcを取り込んで除霜運転終了温度Teと比較し、室外熱交温度Tcが除霜運転終了温度Te以上であれば、除霜運転を停止する。また、CPU210は、室外熱交温度Tcが除霜運転終了温度Te以上でなければ、除霜運転を継続する。【選択図】図2PROBLEM TO BE SOLVED: To provide an air conditioner capable of performing an appropriate defrosting operation according to the amount of frost formed in an outdoor heat exchanger during a heating operation. SOLUTION: When the heating operation is interrupted and the defrosting operation is performed, the CPU 210 reads out the number of units D in the cab and takes in the outside air temperature To. Specifically, the CPU 210 takes in the temperature detected by the outside air temperature sensor 38 via the sensor input unit 240, and removes the temperature by referring to the defrosting operation end condition table 300 using the number of indoor units D and the outside air temperature To. The frost operation end temperature Te is extracted. After that, the CPU 210 starts the defrosting operation, takes in the outdoor heat exchange temperature Tc, compares it with the defrosting operation end temperature Te, and if the outdoor heat exchange temperature Tc is equal to or higher than the defrosting operation end temperature Te, performs the defrosting operation. Stop. Further, if the outdoor heat exchange temperature Tc is not equal to or higher than the defrosting operation end temperature Te, the CPU 210 continues the defrosting operation. [Selection diagram] Fig. 2

Description

本発明は、除霜運転が行える空気調和装置に関する。   The present invention relates to an air conditioner capable of performing a defrosting operation.

空気調和装置が暖房運転を行っているときに外気温度が低いと、蒸発器として機能する室外熱交換器に霜が発生する。室外熱交換器に発生する霜の量が多いと、室外熱交換器における熱交換能力が低下する。   If the outside air temperature is low when the air conditioner is performing heating operation, frost is generated in the outdoor heat exchanger that functions as an evaporator. When there is much quantity of frost which generate | occur | produces in an outdoor heat exchanger, the heat exchange capability in an outdoor heat exchanger will fall.

このため、空気調和装置が暖房運転を行っているときには、室外熱交換器で発生した霜を溶かすために除霜運転が行われる。除霜運転は、暖房運転時間が3時間以上継続しているときや、室外熱交換器の温度が外気温度より5℃以上低い状態が10分間継続する等、室外熱交換器における着霜量が暖房能力に支障をきたすレベルとなっている恐れがあるときに行われる。   For this reason, when the air conditioner is performing the heating operation, the defrosting operation is performed in order to melt the frost generated in the outdoor heat exchanger. In the defrosting operation, when the heating operation time is continued for 3 hours or more, or when the temperature of the outdoor heat exchanger is lower than the outside air temperature by 5 ° C. or more for 10 minutes, the amount of frost formation in the outdoor heat exchanger is This is done when there is a risk of disturbing the heating capacity.

例えば、特許文献1には、室外機に複数台の室内機が接続されて、全ての室内機で暖房運転あるいは冷房運転が行える多室型空気調和装置が、暖房運転中に除霜運転を行うことについて記載されている。具体的には、除霜運転を行うときは、暖房運転を中断して室外熱交換器を蒸発器として機能する状態から凝縮器として機能する状態に切り換え、圧縮機から吐出される高温の冷媒を室外熱交換器に流入させて発生した霜を溶かす。そして、室外熱交換器の温度が例えば10℃以上となれば、室外熱交換器で発生した霜が全て溶けたと判断して除霜運転を終了し、暖房運転に復帰する。   For example, in Patent Document 1, a multi-room air conditioner in which a plurality of indoor units are connected to an outdoor unit and a heating operation or a cooling operation can be performed in all the indoor units performs a defrosting operation during the heating operation. Is described. Specifically, when performing the defrosting operation, the heating operation is interrupted and the outdoor heat exchanger is switched from the state functioning as an evaporator to the state functioning as a condenser, and the high-temperature refrigerant discharged from the compressor is changed. Melts frost generated by flowing into the outdoor heat exchanger. And if the temperature of an outdoor heat exchanger will be 10 degreeC or more, for example, it will judge that all the frost which generate | occur | produced in the outdoor heat exchanger has melted, will complete | finish a defrost operation, and will return to heating operation.

特開平6−26689号公報JP-A-6-26689

ところで、特許文献1に記載の多室型空気調和装置が暖房運転を行うときは、暖房運転を行っている室内機の合計能力によって、室外熱交換器における着霜量が異なる。   By the way, when the multi-room air conditioner described in Patent Document 1 performs the heating operation, the amount of frost formation in the outdoor heat exchanger varies depending on the total capacity of the indoor units performing the heating operation.

暖房運転を行っている室内機の台数が多くて室内機の合計能力が大きい場合は、凝縮器として機能している室内熱交換器における凝縮能力の合計値が大きくなる。一方、暖房運転を行っている室内機の台数が少なくて室内機の合計能力が小さい場合は、凝縮器として機能している室内熱交換器における凝縮能力の合計値が小さくなる。そして、凝縮能力の合計値が小さい場合と比べて、凝縮能力の合計値が大きい場合のほうが凝縮圧力が低くなる。   When the number of indoor units performing the heating operation is large and the total capacity of the indoor units is large, the total value of the condensation capacity in the indoor heat exchanger functioning as a condenser is large. On the other hand, when the number of indoor units performing the heating operation is small and the total capacity of the indoor units is small, the total value of the condensation capacity in the indoor heat exchanger functioning as a condenser is small. And compared with the case where the total value of a condensation capacity is small, the direction where a total value of a condensation capacity is large becomes low.

つまりは、暖房運転を行っている室内機の合計能力が小さい場合と比べて、暖房運転を行っている室内機の合計能力が大きい場合のほうが凝縮圧力が低くなる。凝縮圧力が低くなれば蒸発圧力も低くなって、蒸発圧力と相関のある蒸発温度と外気温度との温度差も大きくなる。従って、暖房運転を行っている室内機の合計能力が小さい場合と比べて、暖房運転を行っている室内機の合計能力が大きい場合のほうが、室外熱交換器での着霜量が多くなる。   In other words, the condensation pressure is lower when the total capacity of the indoor units performing the heating operation is larger than when the total capacity of the indoor units performing the heating operation is small. As the condensing pressure decreases, the evaporating pressure also decreases, and the temperature difference between the evaporating temperature and the outside air temperature that correlates with the evaporating pressure also increases. Therefore, the amount of frost formation in the outdoor heat exchanger is larger when the total capacity of the indoor units performing the heating operation is larger than when the total capacity of the indoor units performing the heating operation is small.

このように、暖房運転している室内機の合計能力によって室外熱交換器での着霜量が異なる多室型空気調和装置で除霜運転を行うとき、特許文献1に記載の空気調和装置のように除霜運転中に室外熱交換器の温度が10℃となったことを条件に除霜運転を終了すると、運転している室内機の合計能力が大きくて室外熱交換器での着霜量が多い場合は、霜の溶け残りが生ずる恐れがあった。また、運転している室内機の合計能力が小さくて室外熱交換器での着霜量が少ない場合は、室外熱交換器の温度が10℃に到達する前に霜が全て溶けている可能性があり、霜が全て溶けてから室外熱交換器の温度が10℃に到達するまでの除霜運転が無駄になっている恐れがあった。   As described above, when the defrosting operation is performed in the multi-room type air conditioner in which the amount of frost formation in the outdoor heat exchanger is different depending on the total capacity of the indoor units performing the heating operation, the air conditioner described in Patent Literature 1 is used. As described above, when the defrosting operation is terminated under the condition that the temperature of the outdoor heat exchanger becomes 10 ° C. during the defrosting operation, the total capacity of the indoor units being operated is large, and the frost formation in the outdoor heat exchanger is performed. When the amount was large, there was a risk that frost would remain unmelted. Moreover, when the total capacity of the indoor units in operation is small and the amount of frost formation in the outdoor heat exchanger is small, there is a possibility that all the frost has melted before the temperature of the outdoor heat exchanger reaches 10 ° C. There was a possibility that the defrosting operation until the temperature of the outdoor heat exchanger reached 10 ° C. after all the frost melted was wasted.

本発明は以上述べた問題点を解決するものであって、暖房運転時に室外熱交換器での着霜量に応じた適切な除霜運転が行える空気調和装置を提供することを目的とする。   The present invention solves the above-described problems, and an object thereof is to provide an air conditioner that can perform an appropriate defrosting operation according to the amount of frost formation in an outdoor heat exchanger during heating operation.

上記の課題を解決するために、本発明の空気調和装置は、圧縮機と四方弁と室外熱交換器と室外熱交換器の温度である室外熱交温度を検出する室外熱交温度検出手段と外気温度を検出する外気温度検出手段を有する室外機と、室内熱交換器を有する複数台の室内機と、圧縮機や四方弁を制御する制御手段を有する。制御手段は、暖房運転を行っているときに室外熱交換器で霜が発生したことを検知すれば、室外熱交換器の除霜運転を開始する。制御手段は、暖房運転中に室外熱交換器で発生した霜を溶かす除霜運転を行うとき、除霜運転を開始する時点で暖房運転を行っている室内機の合計能力と、前記除霜運転を開始する時点で前記外気温度検出手段で検出した外気温度に応じて除霜運転終了温度を決定する。そして、制御手段は、除霜運転中に室外熱交温度検出手段で検出した室外熱交温度を取り込み、取り込んだ室外熱交温度が除霜運転終了温度より高くなれば、除霜運転を終了する。   In order to solve the above problems, an air conditioner of the present invention includes an outdoor heat exchanger temperature detecting means for detecting an outdoor heat exchanger temperature that is a temperature of a compressor, a four-way valve, an outdoor heat exchanger, and an outdoor heat exchanger. It has an outdoor unit having an outside air temperature detecting means for detecting the outside air temperature, a plurality of indoor units having an indoor heat exchanger, and a control means for controlling the compressor and the four-way valve. The control means starts the defrosting operation of the outdoor heat exchanger if it detects that frost is generated in the outdoor heat exchanger during the heating operation. The control means, when performing the defrosting operation to melt the frost generated in the outdoor heat exchanger during the heating operation, the total capacity of the indoor units performing the heating operation at the time of starting the defrosting operation, and the defrosting operation The defrosting operation end temperature is determined according to the outside air temperature detected by the outside air temperature detecting means at the time of starting the operation. Then, the control means takes in the outdoor heat exchange temperature detected by the outdoor heat exchange temperature detection means during the defrosting operation, and ends the defrosting operation when the taken outdoor heat exchange temperature becomes higher than the defrosting operation end temperature. .

上記のように構成した本発明の空気調和装置は、除霜運転前に暖房運転を行っている室内機の合計能力と、除霜運転を開始する時点で外気温度検出手段で検出した外気温度に応じて除霜運転の終了条件を異ならせることで、暖房運転時に室外熱交換器での着霜量に応じた適切な除霜運転が行える。   The air conditioner of the present invention configured as described above has the total capacity of the indoor units that are performing the heating operation before the defrosting operation and the outside air temperature detected by the outside air temperature detecting means at the start of the defrosting operation. Accordingly, by changing the end condition of the defrosting operation, an appropriate defrosting operation can be performed according to the amount of frost formation in the outdoor heat exchanger during the heating operation.

本発明の実施形態である空気調和装置の説明図であり、(A)が冷媒回路図、(B)が室外機制御手段のブロック図である。It is explanatory drawing of the air conditioning apparatus which is embodiment of this invention, (A) is a refrigerant circuit figure, (B) is a block diagram of an outdoor unit control means. 本発明の実施形態における除霜運転の終了条件を示す図面であり、(A)は除霜運転終了条件テーブル、(B)は除霜運転の終了条件を図化したものである。It is drawing which shows the completion | finish conditions of a defrost operation in embodiment of this invention, (A) is a defrost operation completion | finish condition table, (B) illustrates the completion | finish conditions of a defrost operation. 本発明の実施形態における、除霜運転時の処理を示すフローチャートである。It is a flowchart which shows the process at the time of a defrost driving | operation in embodiment of this invention.

以下、本発明の実施の形態を、添付図面に基づいて詳細に説明する。実施形態としては、1台の室外機に3台の室内機が冷媒配管で並列に接続され、全ての室内機で同時に冷房運転あるいは暖房運転が行える空気調和装置を例に挙げて説明する。尚、本発明は以下の実施形態に限定されることはなく、本発明の主旨を逸脱しない範囲で種々変形することが可能である。   Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. As an embodiment, an air conditioner will be described as an example in which three indoor units are connected to one outdoor unit in parallel through refrigerant pipes, and all the indoor units can simultaneously perform a cooling operation or a heating operation. The present invention is not limited to the following embodiments, and can be variously modified without departing from the gist of the present invention.

図1(A)に示すように、本実施形態における空気調和装置1は、3個の液側閉鎖弁27a〜27cと3個のガス側閉鎖弁28a〜28cを有する1台の室外機2と、3台の室内機5a〜5cの室内機を有する。   As shown in FIG. 1 (A), an air conditioner 1 according to the present embodiment includes one outdoor unit 2 having three liquid side closing valves 27a to 27c and three gas side closing valves 28a to 28c. There are three indoor units 5a to 5c.

液管8aの一端は室内機5aの液管接続部52aに接続され、液管8aの他端は室外機2の液側閉鎖弁27aに接続されている。また、液管8bの一端は室内機5bの液管接続部52bに接続され、液管8bの他端は室外機2の液側閉鎖弁27bに接続されている。そして、液管8cの一端は室内機5cの液管接続部52cに接続され、液管8cの他端は室外機2の液側閉鎖弁27cに接続されている。   One end of the liquid pipe 8a is connected to the liquid pipe connecting portion 52a of the indoor unit 5a, and the other end of the liquid pipe 8a is connected to the liquid side closing valve 27a of the outdoor unit 2. Further, one end of the liquid pipe 8b is connected to the liquid pipe connecting portion 52b of the indoor unit 5b, and the other end of the liquid pipe 8b is connected to the liquid side closing valve 27b of the outdoor unit 2. One end of the liquid pipe 8 c is connected to the liquid pipe connection part 52 c of the indoor unit 5 c, and the other end of the liquid pipe 8 c is connected to the liquid side closing valve 27 c of the outdoor unit 2.

ガス管9aの一端は室内機5aのガス管接続部53aに接続され、ガス管9aの他端は室外機2のガス側閉鎖弁28aに接続されている。また、ガス管9bの一端は室内機5bのガス管接続部53bに接続され、ガス管9bの他端は室外機2のガス側閉鎖弁28bに接続されている。そして、ガス管9cの一端は室内機5cのガス管接続部53cに接続され、ガス管9cの他端は室外機2のガス側閉鎖弁28cに接続されている。   One end of the gas pipe 9 a is connected to the gas pipe connection part 53 a of the indoor unit 5 a, and the other end of the gas pipe 9 a is connected to the gas side closing valve 28 a of the outdoor unit 2. In addition, one end of the gas pipe 9b is connected to the gas pipe connection portion 53b of the indoor unit 5b, and the other end of the gas pipe 9b is connected to the gas side shut-off valve 28b of the outdoor unit 2. One end of the gas pipe 9c is connected to the gas pipe connection portion 53c of the indoor unit 5c, and the other end of the gas pipe 9c is connected to the gas side closing valve 28c of the outdoor unit 2.

以上のように、室外機2に室内機5a〜5cが液管8a〜8cおよびガス管9a〜9cでそれぞれ接続されて、空気調和装置1の冷媒回路10が構成されている。
<室外機2の構成>
As described above, the indoor units 5a to 5c are connected to the outdoor unit 2 through the liquid pipes 8a to 8c and the gas pipes 9a to 9c, respectively, so that the refrigerant circuit 10 of the air conditioner 1 is configured.
<Configuration of outdoor unit 2>

室外機2は、圧縮機21と、四方弁22と、室外熱交換器23と、3個の膨張弁24a〜24cと、アキュムレータ25と、室外ファン26と、上述した3個の液側閉鎖弁27a〜27cおよび3個のガス側閉鎖弁28a〜28cと、室外機制御手段200を備えている。そして、室外ファン26および室外機制御手段200を除くこれら各装置が、以下で詳述する各冷媒配管で相互に接続されて、冷媒回路10の一部をなす室外機冷媒回路20を構成している。   The outdoor unit 2 includes a compressor 21, a four-way valve 22, an outdoor heat exchanger 23, three expansion valves 24a to 24c, an accumulator 25, an outdoor fan 26, and the three liquid-side closing valves described above. 27a to 27c, three gas side closing valves 28a to 28c, and an outdoor unit control means 200. These devices other than the outdoor fan 26 and the outdoor unit control means 200 are connected to each other through refrigerant pipes described in detail below to form an outdoor unit refrigerant circuit 20 that forms part of the refrigerant circuit 10. Yes.

圧縮機21は、インバータにより回転数が制御される図示しないモータによって駆動されることで運転能力を可変できる能力可変型圧縮機である。圧縮機21の冷媒吐出口と四方弁22のポートaが吐出管41で接続されている。また、圧縮機21の冷媒吸入側とアキュムレータ25の冷媒流出側が吸入管42で接続されている。   The compressor 21 is a variable capacity compressor that can be driven with a motor (not shown) whose rotation speed is controlled by an inverter to vary the driving capacity. A refrigerant discharge port of the compressor 21 and a port a of the four-way valve 22 are connected by a discharge pipe 41. The refrigerant suction side of the compressor 21 and the refrigerant outflow side of the accumulator 25 are connected by a suction pipe 42.

四方弁22は、冷媒の流れる方向を切り換えるための弁であり、a、b、c、dの4つのポートを備えている。上述したように、ポートaと圧縮機21の冷媒吐出口が吐出管41で接続されている。ポートbと室外熱交換器23の一方の冷媒出入口が冷媒配管43で接続されている。ポートcとアキュムレータ25の冷媒流入側が冷媒配管46で接続されている。そして、ポートdには室外機ガス管45の一端が接続されている。   The four-way valve 22 is a valve for switching the direction in which the refrigerant flows, and includes four ports a, b, c, and d. As described above, the port a and the refrigerant discharge port of the compressor 21 are connected by the discharge pipe 41. The refrigerant outlet 43 is connected to the port b and one refrigerant inlet / outlet of the outdoor heat exchanger 23. The port c and the refrigerant inflow side of the accumulator 25 are connected by a refrigerant pipe 46. One end of the outdoor unit gas pipe 45 is connected to the port d.

室外機ガス管45の他端には、3本の室外機ガス分管45a〜45cの各々の一端が接続されている。室外機ガス分管45aの他端はガス側閉鎖弁28aに接続されている。室外機ガス分管45bの他端はガス側閉鎖弁28bに接続されている。室外機ガス分管45cの他端はガス側閉鎖弁28cに接続されている。   One end of each of the three outdoor unit gas distribution pipes 45 a to 45 c is connected to the other end of the outdoor unit gas pipe 45. The other end of the outdoor unit gas distribution pipe 45a is connected to the gas side closing valve 28a. The other end of the outdoor unit gas distribution pipe 45b is connected to the gas side closing valve 28b. The other end of the outdoor unit gas distribution pipe 45c is connected to the gas side closing valve 28c.

室外熱交換器23は、室外ファン26の回転により図示しない吸込口から室外機2の内部に取り込まれた外気と冷媒を熱交換させる。上述したように、室外熱交換器23の一方の冷媒出入口と四方弁22のポートbが冷媒配管43で接続されている。また、室外熱交換器23の他方の冷媒出入口には室外機液管44の一端が接続されている。室外熱交換器23は、冷媒回路10が冷房サイクルとなる場合は凝縮器として機能し、冷媒回路10が暖房サイクルとなる場合は蒸発器として機能する。   The outdoor heat exchanger 23 exchanges heat between the outside air taken into the outdoor unit 2 from the suction port (not shown) and the refrigerant by the rotation of the outdoor fan 26. As described above, one refrigerant inlet / outlet of the outdoor heat exchanger 23 and the port b of the four-way valve 22 are connected by the refrigerant pipe 43. One end of the outdoor unit liquid pipe 44 is connected to the other refrigerant inlet / outlet of the outdoor heat exchanger 23. The outdoor heat exchanger 23 functions as a condenser when the refrigerant circuit 10 is in a cooling cycle, and functions as an evaporator when the refrigerant circuit 10 is in a heating cycle.

室外機液管44の他端には、3本の室外機液分管44a〜44cの各々の一端が接続されている。室外機液分管44aの他端は液側閉鎖弁27aに接続されている。室外機液分管44bの他端は液側閉鎖弁27bに接続されている。室外機液分管44cの他端は液側閉鎖弁27cに接続されている。   One end of each of the three outdoor unit liquid distribution tubes 44 a to 44 c is connected to the other end of the outdoor unit liquid tube 44. The other end of the outdoor unit liquid distribution pipe 44a is connected to the liquid side closing valve 27a. The other end of the outdoor unit liquid distribution pipe 44b is connected to the liquid side closing valve 27b. The other end of the outdoor unit liquid distribution pipe 44c is connected to the liquid side closing valve 27c.

3個の膨張弁24a〜24cは、各々が図示しないパルスモータにより駆動される電子膨張弁であり、パルスモータに与えられるパルス数によって開度が調整される。膨張弁24aは室外機液分管44aに設けられる。膨張弁24bは室外機液分管44bに設けられる。膨張弁24cは室外機液分管44cに設けられる。膨張弁24a〜24cの開度をそれぞれ調整することによって、室内機5a〜室内機5cに流れる冷媒量がそれぞれ調整される。   Each of the three expansion valves 24a to 24c is an electronic expansion valve that is driven by a pulse motor (not shown), and the opening degree is adjusted by the number of pulses applied to the pulse motor. The expansion valve 24a is provided in the outdoor unit liquid distribution pipe 44a. The expansion valve 24b is provided in the outdoor unit liquid distribution pipe 44b. The expansion valve 24c is provided in the outdoor unit liquid distribution pipe 44c. By adjusting the opening degree of each of the expansion valves 24a to 24c, the amount of refrigerant flowing through the indoor units 5a to 5c is adjusted.

アキュムレータ25は、上述したように、冷媒流入側と四方弁22のポートcが冷媒配管46で接続され、冷媒流出側と圧縮機21の冷媒吸入口が吸入管42で接続されている。アキュムレータ25は、流入した冷媒をガス冷媒と液冷媒とに分離し、ガス冷媒のみを吸入管42を介して圧縮機21に吸入させる。   As described above, in the accumulator 25, the refrigerant inflow side and the port c of the four-way valve 22 are connected by the refrigerant pipe 46, and the refrigerant outflow side and the refrigerant suction port of the compressor 21 are connected by the suction pipe 42. The accumulator 25 separates the inflowing refrigerant into a gas refrigerant and a liquid refrigerant, and causes the compressor 21 to suck only the gas refrigerant through the suction pipe 42.

室外ファン26は、室外熱交換器23の近傍に配置される樹脂材で形成されたプロペラファンであり、図示しないファンモータによって室外ファン26が回転することで、室外機2に設けられた図示しない吸込口から室外機2の内部に外気を取り込み、室外熱交換器23を流れる冷媒と熱交換した外気を室外機2に設けられた図示しない吹出口から室外機2の外部へ放出する。   The outdoor fan 26 is a propeller fan formed of a resin material disposed in the vicinity of the outdoor heat exchanger 23, and the outdoor fan 26 is rotated by a fan motor (not shown) so that the outdoor fan 2 is not shown. Outside air is taken into the interior of the outdoor unit 2 from the suction port, and the outside air heat-exchanged with the refrigerant flowing in the outdoor heat exchanger 23 is discharged to the outside of the outdoor unit 2 from a blower outlet (not shown) provided in the outdoor unit 2.

以上説明した構成の他に、室外機2には各種のセンサが設けられている。図1(A)に示すように、吐出管41には、圧縮機21から吐出される冷媒の圧力を検出する高圧センサ31と、圧縮機21から吐出される冷媒の温度を検出する吐出温度センサ33が設けられている。   In addition to the configuration described above, the outdoor unit 2 is provided with various sensors. As shown in FIG. 1A, a discharge pipe 41 includes a high-pressure sensor 31 that detects the pressure of refrigerant discharged from the compressor 21, and a discharge temperature sensor that detects the temperature of refrigerant discharged from the compressor 21. 33 is provided.

冷媒配管46におけるアキュムレータ25の冷媒流入側近傍には、圧縮機21に吸入される冷媒の圧力を検出する低圧センサ32と、圧縮機21に吸入される冷媒の温度を検出する吸入温度センサ34が設けられている。   In the refrigerant pipe 46, near the refrigerant inflow side of the accumulator 25, there are a low-pressure sensor 32 that detects the pressure of the refrigerant sucked into the compressor 21 and a suction temperature sensor 34 that detects the temperature of the refrigerant sucked into the compressor 21. Is provided.

室外機液管44における室外熱交換器23の近傍には、室外熱交換器23が凝縮器として機能する際に室外熱交換器23から流出する冷媒の温度、あるいは、室外熱交換器23が蒸発器として機能する際に室外熱交換器23に流入する冷媒の温度、つまり、室外熱交換器23の温度(以降、室外熱交温度と記載する)を検出する室外熱交温度検出手段である冷媒温度センサ35が設けられている。また、室外機2の図示しない吸込口付近には、室外機2の内部に流入する外気の温度、すなわち外気温度を検出する外気温度検出手段である外気温度センサ38が設けられている。   In the vicinity of the outdoor heat exchanger 23 in the outdoor unit liquid pipe 44, the temperature of the refrigerant flowing out of the outdoor heat exchanger 23 when the outdoor heat exchanger 23 functions as a condenser, or the outdoor heat exchanger 23 evaporates. Refrigerant which is an outdoor heat exchanger temperature detecting means for detecting the temperature of the refrigerant flowing into the outdoor heat exchanger 23 when functioning as an oven, that is, the temperature of the outdoor heat exchanger 23 (hereinafter referred to as the outdoor heat exchanger temperature). A temperature sensor 35 is provided. In addition, an outdoor air temperature sensor 38 serving as an outdoor air temperature detecting means for detecting the temperature of the outdoor air flowing into the outdoor unit 2, that is, the outdoor air temperature, is provided in the vicinity of a suction port (not shown) of the outdoor unit 2.

室外機液分管44aにおける膨張弁24aと液側閉鎖弁27aの間には、室外機液分管44aを流れる冷媒の温度を検出する液側温度センサ36aが設けられている。室外機液分管44bにおける膨張弁24bと液側閉鎖弁27bの間には、室外機液分管44bを流れる冷媒の温度を検出する液側温度センサ36bが設けられている。室外機液分管44cにおける膨張弁24cと液側閉鎖弁27cの間には、室外機液分管44cを流れる冷媒の温度を検出する液側温度センサ36cが設けられている。   Between the expansion valve 24a and the liquid side closing valve 27a in the outdoor unit liquid distribution pipe 44a, a liquid side temperature sensor 36a for detecting the temperature of the refrigerant flowing through the outdoor unit liquid distribution pipe 44a is provided. Between the expansion valve 24b and the liquid side closing valve 27b in the outdoor unit liquid distribution pipe 44b, a liquid side temperature sensor 36b for detecting the temperature of the refrigerant flowing through the outdoor unit liquid distribution pipe 44b is provided. Between the expansion valve 24c and the liquid side closing valve 27c in the outdoor unit liquid distribution pipe 44c, a liquid side temperature sensor 36c for detecting the temperature of the refrigerant flowing through the outdoor unit liquid distribution pipe 44c is provided.

室外機ガス分管45aには、室外機ガス分管45aを流れる冷媒の温度を検出するガス側温度センサ37aが設けられている。室外機ガス分管45bには、室外機ガス分管45bを流れる冷媒の温度を検出するガス側温度センサ37bが設けられている。室外機ガス分管45cには、室外機ガス分管45cを流れる冷媒の温度を検出するガス側温度センサ37cが設けられている。   The outdoor unit gas distribution pipe 45a is provided with a gas side temperature sensor 37a that detects the temperature of the refrigerant flowing through the outdoor unit gas distribution pipe 45a. The outdoor unit gas distribution pipe 45b is provided with a gas side temperature sensor 37b that detects the temperature of the refrigerant flowing through the outdoor unit gas distribution pipe 45b. The outdoor unit gas distribution pipe 45c is provided with a gas side temperature sensor 37c that detects the temperature of the refrigerant flowing through the outdoor unit gas distribution pipe 45c.

また、室外機2には、本発明の制御手段である室外機制御手段200が備えられている。室外機制御手段200は、室外機2の図示しない電装品箱に格納された制御基板に搭載されており、図1(B)に示すように、CPU210と、記憶部220と、通信部230と、センサ入力部240とを備えている。   Further, the outdoor unit 2 is provided with an outdoor unit control means 200 which is a control means of the present invention. The outdoor unit control means 200 is mounted on a control board stored in an electrical component box (not shown) of the outdoor unit 2, and as shown in FIG. 1B, a CPU 210, a storage unit 220, a communication unit 230, The sensor input unit 240 is provided.

記憶部220は、ROMやRAMで構成されており、室外機2の制御プログラムや各種センサからの検出信号に対応した検出値、圧縮機21や室外ファン26の駆動状態、室内機5aや室内機5b、5cから送信される運転情報(運転/停止情報や設定温度情報等を含む)等を記憶する。通信部230は、各室内機との通信を行うインターフェイスである。センサ入力部240は、室外機2の各種センサでの検出結果を取り込んでCPU210に出力する。   The storage unit 220 includes a ROM and a RAM, and includes detection values corresponding to control programs for the outdoor unit 2 and detection signals from various sensors, driving states of the compressor 21 and the outdoor fan 26, the indoor unit 5a and the indoor unit. Operation information (including operation / stop information, set temperature information, etc.) transmitted from 5b and 5c is stored. The communication unit 230 is an interface that performs communication with each indoor unit. The sensor input unit 240 captures detection results from various sensors of the outdoor unit 2 and outputs them to the CPU 210.

CPU210は、センサ入力部240を介して各種センサでの検出値を定期的(例えば、30秒毎)に取り込むとともに、室内機5a〜5cから送信される運転開始/停止を示す運転状態や運転情報(冷房/暖房といった運転モードや設定温度等)を含んだ信号が通信部230を介して入力される。CPU210は、これら入力された各種情報に基づいて、膨張弁24a〜24cの開度調整、圧縮機21や室外ファン26の駆動制御を行う。
<室内機5a〜5cの構成>
The CPU 210 fetches detection values from various sensors periodically (for example, every 30 seconds) via the sensor input unit 240, and also indicates an operation state and operation information indicating operation start / stop transmitted from the indoor units 5a to 5c. A signal including an operation mode such as cooling / heating and a set temperature is input via the communication unit 230. The CPU 210 adjusts the opening degree of the expansion valves 24 a to 24 c and controls the drive of the compressor 21 and the outdoor fan 26 based on these various pieces of input information.
<Configuration of indoor units 5a to 5c>

次に、室内機5a〜5cについて説明する。室内機5a〜5cは、室内熱交換器51a〜51cと、液管接続部52a〜52cと、ガス管接続部53a〜53cと、室内ファン54a〜54cを備えている。そして、室内ファン54a〜54cを除くこれら各構成装置が以下で詳述する各冷媒配管で相互に接続されて、冷媒回路10の一部をなす室内機冷媒回路50a〜50cを構成している。   Next, the indoor units 5a to 5c will be described. The indoor units 5a to 5c include indoor heat exchangers 51a to 51c, liquid pipe connection parts 52a to 52c, gas pipe connection parts 53a to 53c, and indoor fans 54a to 54c. These constituent devices other than the indoor fans 54 a to 54 c are connected to each other through refrigerant pipes that will be described in detail below, thereby constituting indoor unit refrigerant circuits 50 a to 50 c that form part of the refrigerant circuit 10.

尚、室内機5a〜5cは全て同じ構成を有するため、以下の説明では室内機5aについてのみ各構成の説明を行い、室内機5b、5cの各構成については説明を省略する。尚、図1(A)では、室内機5aの各構成装置に付与した各番号の末尾をaからbあるいはcにそれぞれ変更したものが、室内機5aの各構成装置と対応する室内機5b、5cの各構成装置となる。   Since all the indoor units 5a to 5c have the same configuration, in the following description, only the configuration of the indoor unit 5a will be described, and the description of each configuration of the indoor units 5b and 5c will be omitted. In FIG. 1 (A), the numbers assigned to the constituent devices of the indoor unit 5a are changed from a to b or c, respectively, so that the indoor units 5b corresponding to the constituent devices of the indoor unit 5a, It becomes each component apparatus of 5c.

また、本実施形態の室内機5a〜5cは全て同じ定格能力(以降、能力と記載する)を有するものである。従って、室内機5a〜5cのいずれか2台が運転している場合の定格能力の合計値(以降、合計能力と記載する)は、いずれか1台のみ運転している場合の能力の2倍となり、全ての室内機5a〜5cが運転している場合の合計能力は、いずれか1台のみ運転している場合の能力の3倍となる。   Moreover, all the indoor units 5a to 5c of the present embodiment have the same rated capacity (hereinafter referred to as capacity). Therefore, the total value of the rated capacity when any two of the indoor units 5a to 5c are operating (hereinafter referred to as the total capacity) is twice the capacity when only one of the indoor units is operating. Thus, the total capacity when all the indoor units 5a to 5c are operating is three times the capacity when only one of them is operating.

室内熱交換器51aは、冷媒と、室内ファン54aの回転により室内機5aに備えられた図示しない吸込口から室内機5aの内部に取り込まれた室内空気を熱交換させるものである。室内熱交換器51aの一方の冷媒出入口と液管接続部52aが室内機液管71aで接続されている。室内熱交換器51aの他方の冷媒出入口とガス管接続部53aが室内機ガス管72aで接続されている。尚、液管接続部52aやガス管接続部53aには、各冷媒配管が溶接やフレアナット等によって接続されている。   The indoor heat exchanger 51a exchanges heat between the refrigerant and indoor air taken into the indoor unit 5a from a suction port (not shown) provided in the indoor unit 5a by rotation of the indoor fan 54a. One refrigerant inlet / outlet of the indoor heat exchanger 51a and the liquid pipe connecting portion 52a are connected by an indoor unit liquid pipe 71a. The other refrigerant inlet / outlet of the indoor heat exchanger 51a and the gas pipe connecting portion 53a are connected by an indoor unit gas pipe 72a. Each refrigerant pipe is connected to the liquid pipe connecting part 52a and the gas pipe connecting part 53a by welding, a flare nut or the like.

室内熱交換器51aは、室内機5aが冷房運転を行う場合は蒸発器として機能し、室内機5aが暖房運転を行う場合は凝縮器として機能する。   The indoor heat exchanger 51a functions as an evaporator when the indoor unit 5a performs a cooling operation, and functions as a condenser when the indoor unit 5a performs a heating operation.

室内ファン54aは、室内熱交換器51aの近傍に配置される樹脂材で形成されたクロスフローファンであり、図示しないファンモータによって回転することで、図示しない吸込口から室内機5aの内部に室内空気を取り込み、室内熱交換器51aにおいて冷媒と熱交換した室内空気を室内機5aに備えられた図示しない吹出口から室内へ供給する。   The indoor fan 54a is a cross flow fan formed of a resin material disposed in the vicinity of the indoor heat exchanger 51a, and is rotated by a fan motor (not shown) to enter the indoor unit 5a from the suction port (not shown). Air is taken in and the indoor air heat-exchanged with the refrigerant in the indoor heat exchanger 51a is supplied to the room from an unillustrated air outlet provided in the indoor unit 5a.

以上説明した構成の他に、室内機5aの図示しない吸込口付近には、室内機5aの内部に流入する室内空気の温度、すなわち室内温度を検出する室内温度センサ61aが備えられている。
<冷媒回路10の動作>
In addition to the configuration described above, an indoor temperature sensor 61a for detecting the temperature of indoor air flowing into the indoor unit 5a, that is, the indoor temperature, is provided near the suction port (not shown) of the indoor unit 5a.
<Operation of Refrigerant Circuit 10>

次に、本実施形態の空気調和装置1が空調運転を行うときの冷媒回路10における冷媒の流れや各部の動作を、図1(A)を用いて説明する。尚、以下の説明では、まず、室内機5a〜5cが暖房運転を行う場合について説明し、次に、室内機5a〜5cが冷房運転あるいは除霜運転を行う場合について説明する。ここで、図1(A)における実線矢印は、冷媒回路10における暖房運転時の冷媒の流れを示している。また、図1(A)における破線矢印は、冷媒回路10における冷房運転時あるいは除霜運転時の冷媒の流れを示している。
<暖房運転>
Next, the flow of the refrigerant and the operation of each part in the refrigerant circuit 10 when the air-conditioning apparatus 1 of the present embodiment performs the air conditioning operation will be described with reference to FIG. In the following description, first, the case where the indoor units 5a to 5c perform the heating operation will be described, and then the case where the indoor units 5a to 5c perform the cooling operation or the defrosting operation will be described. Here, the solid line arrow in FIG. 1 (A) indicates the flow of the refrigerant during the heating operation in the refrigerant circuit 10. Moreover, the broken line arrow in FIG. 1 (A) has shown the flow of the refrigerant | coolant at the time of the air_conditionaing | cooling operation in the refrigerant circuit 10, or a defrost operation.
<Heating operation>

空気調和装置1が暖房運転を行う場合、四方弁22が図1(A)に実線で示す状態、すなわち、四方弁22のポートaとポートdが連通するように、また、ポートbとポートcが連通するように切り換えられる。これにより、冷媒回路10が図1(A)に実線矢印で示す方向に冷媒が流れる状態となり、室外熱交換器23が蒸発器として機能するとともに、室内熱交換器51a〜51cがそれぞれ凝縮器として機能する暖房サイクルとなる。   When the air conditioner 1 performs the heating operation, the four-way valve 22 is in the state indicated by the solid line in FIG. 1A, that is, the port a and the port d of the four-way valve 22 communicate with each other, and the port b and the port c. Is switched to communicate. Thereby, the refrigerant circuit 10 enters a state in which the refrigerant flows in the direction indicated by the solid line arrow in FIG. 1A, the outdoor heat exchanger 23 functions as an evaporator, and the indoor heat exchangers 51a to 51c each function as a condenser. It becomes a functioning heating cycle.

上記のような冷媒回路10の状態で圧縮機21が起動すると、圧縮機21から吐出された高圧の冷媒は吐出管41から四方弁22に流入し、四方弁22から室外機ガス管45を流れて室外機ガス分管45a〜45cに分流する。室外機ガス分管45a〜45cに分流した冷媒は、ガス側閉鎖弁28a〜28cを介してガス管9a〜9cに流入する。   When the compressor 21 is started in the state of the refrigerant circuit 10 as described above, the high-pressure refrigerant discharged from the compressor 21 flows into the four-way valve 22 from the discharge pipe 41 and flows through the outdoor unit gas pipe 45 from the four-way valve 22. To the outdoor unit gas distribution pipes 45a to 45c. The refrigerant branched into the outdoor unit gas distribution pipes 45a to 45c flows into the gas pipes 9a to 9c via the gas side closing valves 28a to 28c.

ガス管9aを流れる冷媒は、室内機5aのガス管接続部53aを介して室内機5aに流入する。室内機5aに流入した冷媒は、室内機ガス管72aを流れて室内熱交換器51aに流入し、室内ファン54aの回転により室内機5aの内部に取り込まれた室内空気と熱交換を行って凝縮する。また、ガス管9bを流れる冷媒は、室内機5bのガス管接続部53bを介して室内機5bに流入する。室内機5bに流入した冷媒は、室内機ガス管72bを流れて室内熱交換器51bに流入し、室内ファン54bの回転により室内機5bの内部に取り込まれた室内空気と熱交換を行って凝縮する。そして、ガス管9cを流れる冷媒は、室内機5cのガス管接続部53cを介して室内機5cに流入する。室内機5cに流入した冷媒は、室内機ガス管72cを流れて室内熱交換器51cに流入し、室内ファン54cの回転により室内機5cの内部に取り込まれた室内空気と熱交換を行って凝縮する。   The refrigerant flowing through the gas pipe 9a flows into the indoor unit 5a through the gas pipe connection part 53a of the indoor unit 5a. The refrigerant flowing into the indoor unit 5a flows through the indoor unit gas pipe 72a, flows into the indoor heat exchanger 51a, and condenses by exchanging heat with the indoor air taken into the indoor unit 5a by the rotation of the indoor fan 54a. To do. Moreover, the refrigerant | coolant which flows through the gas pipe 9b flows in into the indoor unit 5b via the gas pipe connection part 53b of the indoor unit 5b. The refrigerant flowing into the indoor unit 5b flows through the indoor unit gas pipe 72b and flows into the indoor heat exchanger 51b, and condenses by exchanging heat with the indoor air taken into the indoor unit 5b by the rotation of the indoor fan 54b. To do. And the refrigerant | coolant which flows through the gas pipe 9c flows in into the indoor unit 5c via the gas pipe connection part 53c of the indoor unit 5c. The refrigerant flowing into the indoor unit 5c flows through the indoor unit gas pipe 72c and flows into the indoor heat exchanger 51c, and condenses by exchanging heat with the indoor air taken into the indoor unit 5c by the rotation of the indoor fan 54c. To do.

このように、室内熱交換器51a〜51cがそれぞれ凝縮器として機能し、室内熱交換器51a〜51cで冷媒と熱交換を行った室内空気が図示しない室内機5a〜5cの吹出口から室内に吹き出されることによって、室内機5a〜5cが設置された各部屋の暖房が行われる。   Thus, the indoor heat exchangers 51a to 51c each function as a condenser, and the indoor air that has exchanged heat with the refrigerant in the indoor heat exchangers 51a to 51c enters the room from the outlets of the indoor units 5a to 5c (not shown). By blowing out, each room in which the indoor units 5a to 5c are installed is heated.

室内熱交換器51aから流出した冷媒は室内機液管71aを流れ、液管接続部52aを介して液管8aに流出する。液管8aを流れる冷媒は、液側閉鎖弁27aを介して室外機2に流入し、液側閉鎖弁27aから室外機液分管44aに流入する。また、室内熱交換器51bから流出した冷媒は室内機液管71bを流れ、液管接続部52bを介して液管8bに流出する。液管8bを流れる冷媒は、液側閉鎖弁27bを介して室外機2に流入し、液側閉鎖弁27bから室外機液分管44bに流入する。また、室内熱交換器51cから流出した冷媒は室内機液管71cを流れ、液管接続部52cを介して液管8cに流出する。液管8cを流れる冷媒は、液側閉鎖弁27cを介して室外機2に流入し、液側閉鎖弁27cから室外機液分管44cに流入する。   The refrigerant that has flowed out of the indoor heat exchanger 51a flows through the indoor unit liquid pipe 71a, and flows out to the liquid pipe 8a through the liquid pipe connecting portion 52a. The refrigerant flowing through the liquid pipe 8a flows into the outdoor unit 2 through the liquid side closing valve 27a, and flows into the outdoor unit liquid distribution pipe 44a from the liquid side closing valve 27a. In addition, the refrigerant that has flowed out of the indoor heat exchanger 51b flows through the indoor unit liquid pipe 71b, and flows out to the liquid pipe 8b through the liquid pipe connecting portion 52b. The refrigerant flowing through the liquid pipe 8b flows into the outdoor unit 2 through the liquid side closing valve 27b, and flows into the outdoor unit liquid distribution pipe 44b from the liquid side closing valve 27b. In addition, the refrigerant that has flowed out of the indoor heat exchanger 51c flows through the indoor unit liquid pipe 71c, and flows out to the liquid pipe 8c through the liquid pipe connecting portion 52c. The refrigerant flowing through the liquid pipe 8c flows into the outdoor unit 2 through the liquid side closing valve 27c, and flows into the outdoor unit liquid distribution pipe 44c from the liquid side closing valve 27c.

室外機液分管44a〜44cを流れる冷媒は、膨張弁24a〜24cによりそれぞれ減圧されて室外機液管44で合流する。室外機液管44で合流した冷媒は、室外機液管44を流れて室外熱交換器23に流入する。室外熱交換器23に流入した冷媒は、室外ファン26の回転により室外機2の内部に取り込まれた外気と熱交換を行って蒸発する。   Refrigerant flowing through the outdoor unit liquid distribution pipes 44 a to 44 c is decompressed by the expansion valves 24 a to 24 c and joined by the outdoor unit liquid pipe 44. The refrigerant merged in the outdoor unit liquid pipe 44 flows through the outdoor unit liquid pipe 44 and flows into the outdoor heat exchanger 23. The refrigerant flowing into the outdoor heat exchanger 23 evaporates by exchanging heat with the outside air taken into the outdoor unit 2 by the rotation of the outdoor fan 26.

室外熱交換器23から冷媒配管43に流出した冷媒は、四方弁22、冷媒配管46、アキュムレータ28、吸入管42の順に流れ、圧縮機21に吸入されて再び圧縮される。
<冷房運転/除霜運転>
The refrigerant that flows out of the outdoor heat exchanger 23 into the refrigerant pipe 43 flows in the order of the four-way valve 22, the refrigerant pipe 46, the accumulator 28, and the suction pipe 42, and is sucked into the compressor 21 and compressed again.
<Cooling operation / Defrosting operation>

空気調和装置1が冷房運転あるいは除霜運転を行う場合、四方弁22が図1(A)に破線で示す状態、すなわち、四方弁22のポートaとポートbが連通するように、また、ポートcとポートdが連通するように切り換えられる。これにより、冷媒回路10が図1(A)に破線矢印で示す方向に冷媒が流れる状態となり、室外熱交換器23が凝縮器として機能するとともに、室内熱交換器51a〜51cがそれぞれ蒸発器として機能する冷房サイクルとなる。   When the air conditioner 1 performs a cooling operation or a defrosting operation, the four-way valve 22 is in a state indicated by a broken line in FIG. 1A, that is, the port a and the port b of the four-way valve 22 communicate with each other. It is switched so that c and port d communicate. As a result, the refrigerant circuit 10 enters a state in which the refrigerant flows in the direction indicated by the broken line arrow in FIG. 1A, the outdoor heat exchanger 23 functions as a condenser, and the indoor heat exchangers 51a to 51c each function as an evaporator. It becomes a functioning cooling cycle.

上記のような冷媒回路10の状態で圧縮機21が起動すると、圧縮機21から吐出された高圧の冷媒は吐出管41から四方弁22に流入し、四方弁22から冷媒配管43を流れて室外熱交換器23に流入する。冷房運転の場合は、室外熱交換器23に流入した冷媒は、室外ファン26の回転により室外機2の内部に取り込まれた外気と熱交換を行って凝縮する。一方、除霜運転の場合は、室外熱交換器23に流入した冷媒は、室外熱交換器23に発生している霜を溶かす。尚、除霜運転の際は、室外ファン24は停止している。   When the compressor 21 is started in the state of the refrigerant circuit 10 as described above, the high-pressure refrigerant discharged from the compressor 21 flows into the four-way valve 22 from the discharge pipe 41 and flows through the refrigerant pipe 43 from the four-way valve 22 to the outdoor. It flows into the heat exchanger 23. In the case of the cooling operation, the refrigerant flowing into the outdoor heat exchanger 23 is condensed by exchanging heat with the outside air taken into the outdoor unit 2 by the rotation of the outdoor fan 26. On the other hand, in the case of the defrosting operation, the refrigerant flowing into the outdoor heat exchanger 23 melts the frost generated in the outdoor heat exchanger 23. Note that the outdoor fan 24 is stopped during the defrosting operation.

室外熱交換器23から室外機液管44に流出した冷媒は、室外機液分管44a〜44cに分流する。室外機液分管44aに流入した冷媒は、全開とされている膨張弁24aを通過し、閉鎖弁27aを介して液管8aに流入する。室外機液分管44bに流入した冷媒は、全開とされている膨張弁24bを通過し、閉鎖弁27bを介して液管8bに流入する。室外機液分管44cに流入した冷媒は、全開とされている膨張弁24cを通過し、閉鎖弁27cを介して液管8cに流入する。   The refrigerant that has flowed out of the outdoor heat exchanger 23 into the outdoor unit liquid pipe 44 is branched into the outdoor unit liquid distribution pipes 44a to 44c. The refrigerant that has flowed into the outdoor unit liquid distribution pipe 44a passes through the fully opened expansion valve 24a, and then flows into the liquid pipe 8a through the closing valve 27a. The refrigerant that has flowed into the outdoor unit liquid distribution pipe 44b passes through the fully opened expansion valve 24b and flows into the liquid pipe 8b through the closing valve 27b. The refrigerant flowing into the outdoor unit liquid distribution pipe 44c passes through the fully opened expansion valve 24c and flows into the liquid pipe 8c through the closing valve 27c.

液管8aを流れる冷媒は、室内機5aの液管接続部52aを介して室内機5aに流入する。液管8bを流れる冷媒は、室内機5bの液管接続部52bを介して室内機5bに流入する。液管8cを流れる冷媒は、室内機5cの液管接続部52cを介して室内機5cに流入する。   The refrigerant flowing through the liquid pipe 8a flows into the indoor unit 5a through the liquid pipe connection part 52a of the indoor unit 5a. The refrigerant flowing through the liquid pipe 8b flows into the indoor unit 5b through the liquid pipe connection part 52b of the indoor unit 5b. The refrigerant flowing through the liquid pipe 8c flows into the indoor unit 5c through the liquid pipe connection part 52c of the indoor unit 5c.

冷房運転では、室内機5aに流入した冷媒は、室内機液管71aを流れて室内熱交換器51aに流入し、室内ファン54aの回転により室内機5aの内部に取り込まれた室内空気と熱交換を行って蒸発する。また、室内機5bに流入した冷媒は、室内機液管71bを流れて室内熱交換器51bに流入し、室内ファン54bの回転により室内機5bの内部に取り込まれた室内空気と熱交換を行って蒸発する。また、室内機5cに流入した冷媒は、室内機液管71cを流れて室内熱交換器51cに流入し、室内ファン54cの回転により室内機5cの内部に取り込まれた室内空気と熱交換を行って蒸発する。このように、室内熱交換器51a〜51cがそれぞれ蒸発器として機能し、室内熱交換器51a〜51cで冷媒と熱交換を行った室内空気が図示しない室内機5a〜5cの吹出口から室内に吹き出されることによって、室内機5a〜5cが設置された各部屋の冷房が行われる。   In the cooling operation, the refrigerant flowing into the indoor unit 5a flows through the indoor unit liquid pipe 71a, flows into the indoor heat exchanger 51a, and exchanges heat with the indoor air taken into the indoor unit 5a by the rotation of the indoor fan 54a. To evaporate. The refrigerant flowing into the indoor unit 5b flows through the indoor unit liquid pipe 71b and flows into the indoor heat exchanger 51b, and exchanges heat with the indoor air taken into the indoor unit 5b by the rotation of the indoor fan 54b. Evaporate. The refrigerant flowing into the indoor unit 5c flows through the indoor unit liquid pipe 71c and flows into the indoor heat exchanger 51c, and exchanges heat with indoor air taken into the indoor unit 5c by the rotation of the indoor fan 54c. Evaporate. Thus, the indoor heat exchangers 51a to 51c each function as an evaporator, and the indoor air that has exchanged heat with the refrigerant in the indoor heat exchangers 51a to 51c enters the room from the outlets of the indoor units 5a to 5c (not shown). By blowing out, each room in which the indoor units 5a to 5c are installed is cooled.

一方、除霜運転では、室内機5a〜5cにおいて室内ファン54a〜54cが停止しているので、室内機5a〜5cの室内熱交換器51a〜51cに流入した冷媒は、室内熱交換器51a〜51cでほとんど室内空気と熱交換を行わない。   On the other hand, in the defrosting operation, since the indoor fans 54a to 54c are stopped in the indoor units 5a to 5c, the refrigerant flowing into the indoor heat exchangers 51a to 51c of the indoor units 5a to 5c is changed to the indoor heat exchangers 51a to 51c. 51c hardly exchanges heat with room air.

室内熱交換器51aから流出した冷媒は室内機ガス管72aを流れ、ガス管接続部53aを介してガス管9aに流出する。ガス管9aを流れる冷媒は、ガス側閉鎖弁28aを介して室外機2に流入し、ガス側閉鎖弁28aから室外機ガス分管45aに流入する。また、室内熱交換器51bから流出した冷媒は室内機ガス管72bを流れ、ガス管接続部53bを介してガス管9bに流出する。ガス管9bを流れる冷媒は、ガス側閉鎖弁28bを介して室外機2に流入し、ガス側閉鎖弁28bから室外機ガス分管45bに流入する。そして、室内熱交換器51cから流出した冷媒は室内機ガス管72cを流れ、ガス管接続部53cを介してガス管9cに流出する。ガス管9cを流れる冷媒は、ガス側閉鎖弁28cを介して室外機2に流入し、ガス側閉鎖弁28cから室外機ガス分管45cに流入する。   The refrigerant that has flowed out of the indoor heat exchanger 51a flows through the indoor unit gas pipe 72a, and flows out to the gas pipe 9a through the gas pipe connecting portion 53a. The refrigerant flowing through the gas pipe 9a flows into the outdoor unit 2 through the gas side closing valve 28a, and flows into the outdoor unit gas distribution pipe 45a from the gas side closing valve 28a. In addition, the refrigerant that has flowed out of the indoor heat exchanger 51b flows through the indoor unit gas pipe 72b, and flows out to the gas pipe 9b through the gas pipe connecting portion 53b. The refrigerant flowing through the gas pipe 9b flows into the outdoor unit 2 through the gas side closing valve 28b, and flows into the outdoor unit gas distribution pipe 45b from the gas side closing valve 28b. And the refrigerant | coolant which flowed out from the indoor heat exchanger 51c flows through the indoor unit gas pipe 72c, and flows out into the gas pipe 9c via the gas pipe connection part 53c. The refrigerant flowing through the gas pipe 9c flows into the outdoor unit 2 through the gas side closing valve 28c, and flows into the outdoor unit gas distribution pipe 45c from the gas side closing valve 28c.

室外機ガス分管45a〜45cを流れる冷媒は、室外機ガス管45で合流する。室外機ガス管45を流れる冷媒は、四方弁22、冷媒配管46、アキュムレータ28、吸入管42の順に流れ、圧縮機21に吸入されて再び圧縮される。
<除霜運転終了条件>
The refrigerant flowing through the outdoor unit gas distribution pipes 45 a to 45 c merges in the outdoor unit gas pipe 45. The refrigerant flowing through the outdoor unit gas pipe 45 flows in the order of the four-way valve 22, the refrigerant pipe 46, the accumulator 28, and the suction pipe 42, and is sucked into the compressor 21 and compressed again.
<Defrosting operation end condition>

次に、図2を用いて、除霜運転終了条件について説明する。この除霜運転終了条件は、図2(A)に示す除霜運転終了条件テーブル300として室外機制御手段200の記憶部220に予め記憶されているものである。尚、以下の説明では、運転している室内機5a〜5cの合計能力の代わりに、室内機5a〜5cの運転台数を用いる。これは、前述したように本実施形態の室内機5a〜5cが全て同じ能力であることから、合計能力を運転台数と読み替えることができるために可能となる。   Next, the defrosting operation end condition will be described with reference to FIG. This defrosting operation end condition is stored in advance in the storage unit 220 of the outdoor unit control means 200 as the defrosting operation end condition table 300 shown in FIG. In the following description, the number of operating indoor units 5a to 5c is used instead of the total capacity of the operating indoor units 5a to 5c. This is possible because the indoor units 5a to 5c of the present embodiment all have the same capacity as described above, and the total capacity can be read as the number of operating units.

図2(A)に示すように、除霜運転終了条件テーブル300には、除霜運転を開始する時点(以降、除霜運転開始時点と記載する)で暖房運転を行っている室内機5a〜5cの台数(単位:台。以降、運転室内機台数Dと記載する)と、除霜運転開始時点の外気温度(単位:℃。以降、外気温度Toと記載する)に応じて、除霜運転終了温度(単位:℃。以降、除霜運転終了温度Teと記載する)が定められている。   As shown in FIG. 2A, in the defrosting operation end condition table 300, the indoor units 5a to 5a that are performing the heating operation at the time of starting the defrosting operation (hereinafter referred to as the time of starting the defrosting operation). The defrosting operation is performed according to the number of units 5c (unit: unit; hereinafter referred to as the number D of operating indoor units) and the outside air temperature at the time of starting the defrosting operation (unit: ° C. Hereinafter referred to as the outside temperature To). An end temperature (unit: ° C., hereinafter referred to as a defrosting operation end temperature Te) is defined.

ここで、除霜運転開始時点とは、暖房運転中に除霜運転開始条件が成立した時点である。除霜運転開始条件とは、予め試験等を行って定められて記憶部220に記憶されているものであり、室外熱交換器23での着霜量が暖房運転に支障をきたすレベルであることを示すものである。尚、除霜運転開始条件としては、例えば、暖房運転が180分間継続されている場合や、暖房運転が30分間継続されたときの室外熱交温度Tsが外気温度Toよりも5℃以上低い状態が10分間継続した場合、等である。尚、暖房運転中に上記除霜運転開始条件が成立すれば、暖房運転を中断して除霜運転が実行される。   Here, the defrosting operation start time is the time when the defrosting operation start condition is satisfied during the heating operation. The defrosting operation start condition is determined in advance by performing a test or the like and stored in the storage unit 220, and the amount of frost formation in the outdoor heat exchanger 23 is at a level that interferes with the heating operation. Is shown. In addition, as a defrosting operation start condition, for example, when the heating operation is continued for 180 minutes, or when the outdoor heat exchange temperature Ts when the heating operation is continued for 30 minutes is lower than the outside air temperature To by 5 ° C. or more For 10 minutes, etc. In addition, if the said defrost operation start conditions are satisfied during heating operation, heating operation will be interrupted and defrost operation will be performed.

また、除霜運転終了温度Teとは、除霜運転時の室外熱交換器23の温度(単位:℃。以降、室外熱交温度Tcと記載する)の目標値であり、除霜運転を行って室外熱交温度Tcが除霜運転終了温度Te以上の温度となれば、室外熱交換器23で発生した霜が全て溶けたと判断して除霜運転を終了する温度である。尚、除霜運転開始時点の外気温度Toを用いるのは、室外熱交換器23で霜が発生しているときの実際の外気温度であることと、除霜運転時は室外ファン26を停止させるために外気温度Toを正確に検出できない恐れがあるためである。   The defrosting operation end temperature Te is a target value of the temperature of the outdoor heat exchanger 23 (unit: ° C., hereinafter referred to as the outdoor heat exchange temperature Tc) during the defrosting operation, and the defrosting operation is performed. If the outdoor heat exchange temperature Tc is equal to or higher than the defrosting operation end temperature Te, it is determined that all the frost generated in the outdoor heat exchanger 23 has melted and the defrosting operation is ended. Note that the use of the outside air temperature To at the start of the defrosting operation is the actual outside air temperature when frost is generated in the outdoor heat exchanger 23, and the outdoor fan 26 is stopped during the defrosting operation. For this reason, the outside air temperature To may not be detected accurately.

具体的には、運転室内機台数Dが2台超(D>2)であるときに、外気温度Toが−20℃未満である場合の除霜運転終了温度Teが7℃、外気温度Toが10℃以上である場合の除霜運転終了温度Teが16℃と定められている。そして、外気温度Toが−20℃以上10℃未満である場合の除霜運転終了温度Teは、計算式:Te=0.3×To+13(℃)で求められる温度と定められている。   Specifically, when the number D of operating indoor units is more than two (D> 2), the defrosting operation end temperature Te when the outside air temperature To is less than −20 ° C. is 7 ° C., and the outside air temperature To is The defrosting operation end temperature Te when the temperature is 10 ° C. or higher is set to 16 ° C. The defrosting operation end temperature Te when the outside air temperature To is −20 ° C. or higher and lower than 10 ° C. is determined as a temperature obtained by the calculation formula: Te = 0.3 × To + 13 (° C.).

一方、運転室内機台数Dが2台以下(D≦2)であるときに、外気温度Toが−20℃未満である場合の除霜運転終了温度Teが5℃、外気温度Toが0℃以上である場合の除霜運転終了温度Teが13℃と定められている。そして、外気温度Toが−20℃以上0℃未満である場合の除霜運転終了温度Teは、計算式:Te=0.4×To+13(℃)で求められる温度と定められている。   On the other hand, when the operating indoor unit number D is 2 or less (D ≦ 2), the defrosting operation end temperature Te is 5 ° C. and the outside air temperature To is 0 ° C. or more when the outside air temperature To is less than −20 ° C. In this case, the defrosting operation end temperature Te is determined to be 13 ° C. The defrosting operation end temperature Te when the outside air temperature To is −20 ° C. or higher and lower than 0 ° C. is determined as a temperature obtained by the calculation formula: Te = 0.4 × To + 13 (° C.).

以上説明した除霜運転終了条件テーブル300を図示したものが図2(B)である。図2(B)において、縦軸が除霜運転終了温度Teであり、横軸が外気温度である。そして、図2(B)のうち、上図は運転室内機台数Dが2台超(D>2)の場合を、下図は運転室内機台数Dが2台以下(D≦2)である場合を、それぞれ示している。いずれの図においても、除霜運転中に室外熱交温度Tcが、外気温度Toに対する除霜運転終了温度Teの変化を示す折れ線より上の温度となれば、除霜運転を終了する。   FIG. 2B illustrates the defrosting operation end condition table 300 described above. In FIG. 2B, the vertical axis is the defrosting operation end temperature Te, and the horizontal axis is the outside air temperature. In FIG. 2B, the upper figure shows the case where the number D of operating indoor units is more than two (D> 2), and the lower figure shows the case where the number D of operating indoor units is two or less (D ≦ 2). Respectively. In any figure, if the outdoor heat exchanger temperature Tc becomes a temperature above the broken line which shows the change of the defrosting operation end temperature Te with respect to the outside air temperature To during the defrosting operation, the defrosting operation is ended.

尚、上述した運転室内機台数Dが2台超であるとき、および、運転室内機台数Dが2台以下であるときの外気温度To=−20℃が、本発明の第1外気温度To1である。また、運転室内機台数Dが2台超であるときの外気温度To=10℃、および、運転室内機台数Dが2台以下であるときの外気温度To=0℃が、本実施形態の第2外気温度To2である。また、除霜運転終了条件テーブル300を区分する運転室内機台数D=2台が、本実施形態の閾台数である。   In addition, when the number D of driving indoor units mentioned above is more than two, and when the number D of driving indoor units is two or less, the outside air temperature To = -20 degreeC is 1st outside air temperature To1 of this invention. is there. In addition, the outside air temperature To = 10 ° C. when the number of operating indoor units D is more than two and the outside air temperature To = 0 ° C. when the number of operating indoor units D is two or less are the first of the present embodiment. 2 The outside air temperature To2. In addition, the number D of indoor operating units D = 2 in the defrosting operation end condition table 300 is the threshold number in the present embodiment.

以上説明した各除霜運転終了温度Teのうち第1外気温度To1以上第外気温度To2未満では、上述したように、運転室内機台数Dと外気温度Toに応じて除霜運転終了温度Teを異ならせている。これは、以下に記載する理由による。   Of the defrosting operation end temperatures Te described above, when the temperature is equal to or greater than the first outside air temperature To1 and less than the first outside air temperature To2, the defrosting operation end temperature Te is different depending on the number of operating indoor units D and the outside air temperature To as described above. It is This is due to the reason described below.

空気調和装置1が暖房運転を行っているときは、前述したように室外熱交換器23が蒸発器として機能する。このとき、外気温度Toより暖房運転時の室外熱交換器23の温度(単位:℃。以降、除霜運転時の室外熱交温度Tcと区別するために、暖房運転時の室外熱交温度をTsと記載する)が所定温度、例えば、5℃以上低くなると、室外熱交換器23に霜が発生する。   When the air conditioner 1 is performing the heating operation, the outdoor heat exchanger 23 functions as an evaporator as described above. At this time, the temperature of the outdoor heat exchanger 23 during heating operation (unit: ° C.) from the outdoor air temperature To, in order to distinguish the outdoor heat exchange temperature during heating operation from the outdoor heat exchange temperature Tc during defrosting operation. When Ts) is lowered by a predetermined temperature, for example, 5 ° C. or more, frost is generated in the outdoor heat exchanger 23.

暖房運転中の室外熱交換器23における着霜量は、外気温度Toと室外熱交温度Tsの温度差に応じて変化する。具体的には、外気温度Toが同じである場合は、室外熱交温度Tsが低いほど着霜量が多くなる。また、室外熱交温度Tsが同じである場合は、外気温度Toが高いほど着霜量が多くなる。つまり、外気温度Toから室外熱交温度Tsを減じた温度差が大きいほど着霜量が多くなる。   The amount of frost formation in the outdoor heat exchanger 23 during the heating operation changes according to the temperature difference between the outdoor temperature To and the outdoor heat exchange temperature Ts. Specifically, when the outdoor air temperature To is the same, the lower the outdoor heat exchange temperature Ts, the greater the amount of frost formation. Moreover, when the outdoor heat exchange temperature Ts is the same, the amount of frost formation increases as the outdoor air temperature To increases. That is, the amount of frost formation increases as the temperature difference obtained by subtracting the outdoor heat exchange temperature Ts from the outside air temperature To increases.

ここで、暖房運転時の室外熱交温度Tsは、蒸発器として機能している室外熱交換器23での蒸発圧力と相関のある温度であり、蒸発圧力が上がれば室外熱交温度Tsも上がり、蒸発圧力が下がれば室外熱交温度Tsも下がる。そして、蒸発圧力は運転室内機台数Dに応じて変化する。   Here, the outdoor heat exchange temperature Ts during the heating operation is a temperature correlated with the evaporation pressure in the outdoor heat exchanger 23 functioning as an evaporator. If the evaporation pressure increases, the outdoor heat exchange temperature Ts also increases. If the evaporation pressure decreases, the outdoor heat exchange temperature Ts also decreases. Then, the evaporation pressure changes according to the number D of indoor operating units.

暖房運転時に凝縮器として機能する室内熱交換器の台数が多いと、室内熱交換器の凝縮能力が大きくなって凝縮圧力が低くなり、これに伴って蒸発圧力も低くなる、つまり、室外熱交温度Tsも下がる。これに対し、暖房運転時に凝縮器として機能する室内熱交換器の台数が少ないと、室内熱交換器の凝縮能力が小さくなって凝縮圧力が高くなり、これに伴って蒸発圧力も高くなる、つまり、室外熱交温度Tsも上がる。   If there are many indoor heat exchangers that function as condensers during heating operation, the condensation capacity of the indoor heat exchanger will increase and the condensation pressure will decrease, and the evaporation pressure will decrease accordingly. The temperature Ts also decreases. On the other hand, if the number of indoor heat exchangers functioning as condensers during heating operation is small, the condensation capacity of the indoor heat exchanger is reduced and the condensation pressure is increased, and accordingly, the evaporation pressure is also increased. The outdoor heat exchange temperature Ts also increases.

本実施形態では、以上説明した外気温度Toおよび運転室内機台数Dと室外熱交換器23での着霜量の関係を考慮し、運転室内機台数Dが2台超である場合は外気温度Toが−20℃以上10℃未満、および、運転室内機台数Dが2台以下である場合は外気温度Toが−20℃以上0℃未満、のそれぞれで外気温度Toが高くなるにつれて除霜運転終了温度Teが高くなるようにしている。そして、運転室内機台数Dが2台超である場合の、外気温度Toが−20℃以上10℃未満で除霜運転終了温度Teを上昇させる度合(Te=0.3×To+13、の「0.3」)は、運転室内機台数Dが2台超である場合より室外熱交換器23での着霜量が少ないと考えられる運転室内機台数Dが2台以下である場合の、外気温度Toが−20℃以上0℃未満で除霜運転終了温度Teを上昇させる度合(Te=0.4×To+13、の「0.3」)よりも小さく設定している。   In the present embodiment, in consideration of the relationship between the outdoor air temperature To and the number of operating indoor units D described above and the amount of frost formation in the outdoor heat exchanger 23, the outdoor air temperature To when the number of operating indoor units D is more than two. Is -20 ° C. or more and less than 10 ° C. and the number of indoor units D in operation is 2 or less, the defrosting operation is finished as the outside air temperature To becomes higher in each of the outside air temperature To is −20 ° C. or more and less than 0 ° C. The temperature Te is set high. Then, when the number D of operating indoor units is more than two, the degree of increasing the defrosting operation end temperature Te when the outside air temperature To is −20 ° C. or more and less than 10 ° C. (Te = 0.3 × To + 13, “0 .3 ") is the outside air temperature when the number of operating indoor units D, which is considered to have a smaller amount of frost formation in the outdoor heat exchanger 23 than when the number of operating indoor units D is more than 2, is 2 or less. It is set to be smaller than the degree to which the defrosting operation end temperature Te is increased when To is −20 ° C. or more and less than 0 ° C. (Te = 0.4 × To + 13, “0.3”).

つまり、運転室内機台数Dが2台以下の場合は、室外熱交換器23での着霜量が少ないと考えて、除霜運転終了温度Te=5℃を下限温度として、運転室内機台数Dが2台超の場合よりも除霜運転終了温度Teを低くする。これにより、除霜運転終了温度Teを5℃以上として室外熱交換器23で発生した霜を確実に溶かしつつ、除霜運転を開始してから室外熱交温度Tcが除霜運転終了温度Teに到達するまでの時間が短くして無駄な除霜運転が行われることを防止できる。   That is, when the number D of operation indoor units is 2 or less, it is considered that the amount of frost formation in the outdoor heat exchanger 23 is small, and the defrosting operation end temperature Te = 5 ° C. is set as the lower limit temperature, and the number D of operation indoor units D The defrosting operation end temperature Te is made lower than in the case of more than two. As a result, the defrosting operation end temperature Te is set to 5 ° C. or higher and the outdoor heat exchanger temperature Tc is changed to the defrosting operation end temperature Te after starting the defrosting operation while reliably melting the frost generated in the outdoor heat exchanger 23. It is possible to prevent useless defrosting operation by shortening the time to reach.

一方、運転室内機台数Dが2台超の場合は、室外熱交換器23での着霜量が多いと考えて、除霜運転終了温度Teの下限温度を運転室内機台数Dが2台以下の場合の下限温度である5℃より高い7℃とし、かつ、運転室内機台数Dが2台以下の場合よりも除霜運転終了温度Teを高くする。これにより、運転室内機台数Dが2台以下の場合と比べて除霜運転を開始してから室外熱交温度Tcが除霜運転終了温度Teに到達するまでの時間が長くなり、かつ、運転室内機台数Dが2台以下の場合と比べて除霜運転時の室外熱交温度Tcが高くなるので、室外熱交換器23における霜の溶け残りを防止できる。   On the other hand, if the number of operating indoor units D is more than 2, the amount of frost formation in the outdoor heat exchanger 23 is considered to be large, and the lower limit temperature of the defrosting operation end temperature Te is set to 2 or less. In this case, the defrosting operation end temperature Te is set higher than that in the case where the lower limit temperature is set to 7 ° C higher than 5 ° C and the number D of operating indoor units is two or less. As a result, the time from when the defrosting operation is started to when the outdoor heat exchange temperature Tc reaches the defrosting operation end temperature Te becomes longer than when the number of operation indoor units D is two or less, and the operation Since the outdoor heat exchange temperature Tc at the time of defrosting operation becomes high compared with the case where the number D of indoor units is 2 or less, the frost remaining in the outdoor heat exchanger 23 can be prevented.

尚、各運転室内機台数Dにおける第1外気温度To1〜第外気温度To2の間の、除霜運転終了温度Teの算出式(D>2のとき:Te=0.3×To+13、D≧2のとき:Te=0.4×To+13)は、予め試験等を行って求められるものであり、除霜運転中に室外熱交温度Tcがこれらの算出式で求めた除霜運転終了温度Te以上となれば、室外熱交換器23で発生した霜が完全に溶けることが判明しているものである。   A calculation formula for the defrosting operation end temperature Te between the first outside air temperature To1 and the first outside air temperature To2 in each operating indoor unit number D (when D> 2: Te = 0.3 × To + 13, D ≧ 2) When: Te = 0.4 × To + 13) is obtained by conducting a test or the like in advance, and the outdoor heat exchange temperature Tc is equal to or higher than the defrosting operation end temperature Te obtained by these calculation formulas during the defrosting operation. Then, it has been found that the frost generated in the outdoor heat exchanger 23 is completely melted.

尚、運転室内機台数Dに関わらず外気温度Toが−20℃未満であれば、それぞれ除霜運転終了温度Teを一定としている(D>2ではTe=7℃、D≦2ではTe=5℃)。これは、外気温度Toが−20℃より低いと空気中に含まれる水蒸気量が少ないために、室外熱交換器23における着霜量が少なくなることを考慮したものであり、外気温度Toが−20℃より低いときの除霜運転中に室外熱交温度Tcが除霜運転終了温度Te(7℃あるいは5℃)以上となれば、室外熱交換器23で発生した霜が完全に溶けることが予め試験等を行って判明しているものである。   If the outside air temperature To is less than −20 ° C. regardless of the number of operating indoor units D, the defrosting operation end temperature Te is constant (Te = 7 ° C. for D> 2 and Te = 5 for D ≦ 2). ° C). This is because when the outside air temperature To is lower than −20 ° C., the amount of water vapor contained in the air is small, so that the amount of frost formation in the outdoor heat exchanger 23 is reduced, and the outside air temperature To is − If the outdoor heat exchange temperature Tc becomes equal to or higher than the defrosting operation end temperature Te (7 ° C or 5 ° C) during the defrosting operation at a temperature lower than 20 ° C, the frost generated in the outdoor heat exchanger 23 may be completely melted. It has been found by conducting a test or the like in advance.

また、運転室内機台数Dが2台超で外気温度Toが10℃以上の場合と、運転室内機台数Dが2台以下で外気温度Toが0℃以上の場合も、それぞれ除霜運転終了温度Teを一定としている(D>2ではTe=16℃、D≦2ではTe=13℃)。この場合の除霜運転終了温度Teも予め試験等を行って求められる温度であり、各運転室内機台数Dで外気温度Toが第2外気温度To2以上であるときの除霜運転中に室外熱交温度Tcが上記の除霜運転終了温度Te以上となれば、室外熱交換器23で発生した霜が完全に溶けることが判明している温度である。
<除霜運転時の制御の流れ>
The defrosting operation end temperature is also different when the number of operating indoor units D is more than two and the outside air temperature To is 10 ° C. or more, and when the number of operating indoor units D is 2 or less and the outside air temperature To is 0 ° C. or more. Te is constant (Te = 16 ° C. for D> 2 and Te = 13 ° C. for D ≦ 2). The defrosting operation end temperature Te in this case is also a temperature obtained by conducting a test or the like in advance, and the outdoor heat during the defrosting operation when the outdoor air temperature To is equal to or higher than the second outdoor air temperature To2 in each operating indoor unit number D. If the alternating temperature Tc is equal to or higher than the defrosting operation end temperature Te, the frost generated in the outdoor heat exchanger 23 has been found to be completely melted.
<Control flow during defrosting operation>

次に、図3を用いて、空気調和装置1が暖房運転中に除霜運転を行うときの制御について説明する。図3は、空気調和装置1が暖房運転中に除霜運転を行う際の、室外機制御手段200のCPU210が行う処理の流れを示すフローチャートである。図3において、STは処理のステップを表し、これに続く数字はステップの番号を表している。尚、図3は、本発明に関わる処理を中心に説明するものであり、これ以外の処理、例えば、空調運転時の使用者の要求に応じた圧縮機21の運転制御等といった、空気調和装置1の一般的な制御に関わる処理については説明を省略する。   Next, control when the air-conditioning apparatus 1 performs the defrosting operation during the heating operation will be described with reference to FIG. FIG. 3 is a flowchart showing a flow of processing performed by the CPU 210 of the outdoor unit control means 200 when the air conditioner 1 performs the defrosting operation during the heating operation. In FIG. 3, ST represents a process step, and the number following this represents a step number. Note that FIG. 3 mainly describes processing related to the present invention, and other processing, for example, an air conditioner such as operation control of the compressor 21 according to a user's request during air-conditioning operation. Description of processing related to general control 1 is omitted.

空気調和装置1が暖房運転を行っているとき、室外機制御手段200のCPU210は、除霜運転開始条件が成立しているか否かを判断する(ST1)。ここで、除霜運転開始条件とは、前述したように、予め試験等を行って定められて記憶部220に記憶されているものであり、室外熱交換器23での着霜量が暖房運転に支障をきたすレベルであることを示すものである。   When the air conditioner 1 is performing the heating operation, the CPU 210 of the outdoor unit control means 200 determines whether or not the defrosting operation start condition is satisfied (ST1). Here, as described above, the defrosting operation start condition is determined by performing a test or the like in advance and stored in the storage unit 220, and the amount of frost formation in the outdoor heat exchanger 23 is the heating operation. This indicates that the level is disturbing.

除霜運転開始条件が成立していなければ(ST1−No)、CPU210は、暖房運転を継続し(ST11)、ST1に処理を戻す。除霜運転開始条件が成立していれば(ST1−Yes)、CPU210は、運転室内機台数Dを記憶部220nより読みだす(ST2)。尚、記憶部220には、図示は省略するが、室内機5a〜5cの運転状態(運転/停止)や運転モード(冷房/暖房)、設定温度等を記憶するテーブルが記憶されており、CPU210はこのテーブルにアクセスして運転室内機台数Dを読み出す。   If the defrosting operation start condition is not satisfied (ST1-No), CPU 210 continues the heating operation (ST11) and returns the process to ST1. If the defrosting operation start condition is satisfied (ST1-Yes), the CPU 210 reads the number D of operating indoor units from the storage unit 220n (ST2). Although not shown, the storage unit 220 stores a table for storing the operation state (operation / stop) of the indoor units 5a to 5c, the operation mode (cooling / heating), the set temperature, and the like. Accesses this table and reads out the number D of indoor operating units.

次に、CPU210は、外気温度Toを取り込む(ST3)。具体的には、CPU210は、外気温度センサ38で検出した温度をセンサ入力部240を介して取り込み、取り込んだ外気温度Toを記憶部220に記憶する。   Next, the CPU 210 takes in the outside air temperature To (ST3). Specifically, the CPU 210 takes in the temperature detected by the outside air temperature sensor 38 via the sensor input unit 240 and stores the taken in outside temperature To in the storage unit 220.

次に、CPU210は、ST2で読みだした運転室内機台数DとST3で取り込んだ外気温度Toを用い、記憶部220に記憶している除霜運転終了条件テーブル300を参照して除霜運転終了温度Teを抽出する(ST4)。   Next, the CPU 210 uses the operating indoor unit number D read in ST2 and the outside air temperature To taken in ST3, and refers to the defrosting operation end condition table 300 stored in the storage unit 220 to end the defrosting operation. The temperature Te is extracted (ST4).

次に、CPU210は、除霜運転準備処理を行う(ST5)。ここで除霜運転準備処理とは、圧縮機21と室外ファン26を停止するとともに、通信部230を介して室内機5a〜5cに対し室内ファン54a〜54cを停止するよう指示して暖房運転を停止するとともに、四方弁22を切り替えて冷媒回路10を暖房サイクルから冷房サイクルに切り替えることである。   Next, the CPU 210 performs a defrosting operation preparation process (ST5). Here, the defrosting operation preparation process stops the compressor 21 and the outdoor fan 26 and instructs the indoor units 5a to 5c to stop the indoor fans 54a to 54c via the communication unit 230 to perform the heating operation. In addition to stopping, the four-way valve 22 is switched to switch the refrigerant circuit 10 from the heating cycle to the cooling cycle.

次に、CPU210は、圧縮機21を所定回転数、例えば70rpsで起動して(ST6)、除霜運転を開始する。尚、CPU210は、除霜運転を続けている間は、圧縮機21の回転数を上記所定回転数に維持する。   Next, the CPU 210 starts the compressor 21 at a predetermined rotation speed, for example, 70 rps (ST6), and starts the defrosting operation. The CPU 210 maintains the rotational speed of the compressor 21 at the predetermined rotational speed while continuing the defrosting operation.

次に、CPU210は、室外熱交温度Tcを取り込む(ST7)。具体的には、CPU210は、冷媒温度センサ36で検出した冷媒温度をセンサ入力部240を介して取り込み、取り込んだ冷媒温度を室外熱交温度Tcとして記憶部220に記憶する。   Next, the CPU 210 takes in the outdoor heat exchange temperature Tc (ST7). Specifically, the CPU 210 takes in the refrigerant temperature detected by the refrigerant temperature sensor 36 via the sensor input unit 240, and stores the taken-in refrigerant temperature in the storage unit 220 as the outdoor heat exchange temperature Tc.

次に、CPU210は、ST7で取り込んだ室外熱交温度Tcが、ST4で抽出した除霜運転終了温度Te以上であるか否かを判断する(ST8)。室外熱交温度Tcが除霜運転終了温度Te以上でなければ(ST8−No)、CPU210は、ST6に処理を戻して除霜運転を継続する。   Next, the CPU 210 determines whether or not the outdoor heat exchange temperature Tc captured in ST7 is equal to or higher than the defrosting operation end temperature Te extracted in ST4 (ST8). If the outdoor heat exchange temperature Tc is not equal to or higher than the defrosting operation end temperature Te (ST8-No), the CPU 210 returns the process to ST6 and continues the defrosting operation.

室外熱交温度Tcが除霜運転終了温度Te以上であれば(ST8−Yes)、CPU210は、除霜運転を停止して運転再開処理を行う(ST9)。ここで、運転再開処理とは、圧縮機21を停止するとともに、四方弁22を切り替えて冷媒回路10を冷房サイクルから暖房サイクルに切り替えることである。   If the outdoor heat exchange temperature Tc is equal to or higher than the defrosting operation end temperature Te (ST8-Yes), the CPU 210 stops the defrosting operation and performs an operation restart process (ST9). Here, the operation restart process is to stop the compressor 21 and switch the four-way valve 22 to switch the refrigerant circuit 10 from the cooling cycle to the heating cycle.

ST9の運転再開処理を終えたCPU210は、暖房運転を再開し(ST10)、ST1に処理を戻す。CPU210は、暖房運転再開時に圧縮機21および室外ファン26を室内機5a〜5cで要求される能力に応じた回転数で駆動するとともに、通信部230を介して室内機5a〜5cに対し室内ファン54a〜54cを回転させるよう指示する。   CPU210 which finished the operation resumption process of ST9 restarts heating operation (ST10), and returns a process to ST1. The CPU 210 drives the compressor 21 and the outdoor fan 26 at the number of rotations according to the capacity required of the indoor units 5a to 5c when resuming the heating operation, and also uses the indoor unit 5a to 5c to the indoor fan via the communication unit 230. Instruct to rotate 54a-54c.

以上説明したように、本実施形態の空気調和装置1では、暖房運転時の運転室内機台数Dと外気温度Toに応じて、除霜運転終了条件である除霜運転終了温度Teを異ならせる。これにより、暖房運転時の室外熱交換器23における着霜量に応じた除霜運転が行え、霜が全て溶けた後も除霜運転を続けるといった無駄がなくなるとともに、霜の溶け残りも防止できる。   As described above, in the air conditioner 1 of the present embodiment, the defrosting operation end temperature Te, which is the defrosting operation end condition, is varied according to the number D of operating indoor units during the heating operation and the outside air temperature To. Thereby, the defrosting operation according to the amount of frost formation in the outdoor heat exchanger 23 during the heating operation can be performed, and there is no waste of continuing the defrosting operation even after all the frost has melted, and the remaining frost can be prevented. .

尚、以上説明した実施形態では、暖房運転をしている室内機5a〜5cの合計能力に代えて、暖房運転時の運転室内機台数Dを用いて除霜運転終了温度Teを決定した。しかし、複数台の室内機の各能力が異なる場合は、暖房運転時の運転室内機台数ではなく、そのとき暖房運転している室内機の合計能力を用いて除霜運転終了温度Teを決定すればよい。この場合、前述した閾台数に代えて閾合計能力を定めて、この閾合計台数以上または未満のそれぞれで外気温度Toに応じた除霜運転終了温度Teを定めればよい。   In the embodiment described above, the defrosting operation end temperature Te is determined using the number D of operating indoor units during the heating operation, instead of the total capacity of the indoor units 5a to 5c performing the heating operation. However, when each of the indoor units has different capacities, the defrosting operation end temperature Te should be determined using the total capacity of the indoor units that are in the heating operation, not the number of operating indoor units in the heating operation. That's fine. In this case, instead of the threshold number described above, the threshold total capacity may be determined, and the defrosting operation end temperature Te corresponding to the outside air temperature To may be determined for each of the threshold total number or more.

1 空気調和装置
2 室外機
5a〜5c 室内機
21 圧縮機
23 室外熱交換器
35 冷媒温度センサ
38 外気温度センサ
51 室内熱交換器
200 室外機制御部
210 CPU
220 記憶部
240 センサ入力部
300 除霜運転終了条件テーブル
D 運転室内機台数
Tc 除霜運転時の室外熱交温度
Ts 暖房運転時の室外熱交温度
Te 除霜運転終了温度
To 外気温度
To1 第1外気温度
To2 第2外気温度
DESCRIPTION OF SYMBOLS 1 Air conditioning apparatus 2 Outdoor unit 5a-5c Indoor unit 21 Compressor 23 Outdoor heat exchanger 35 Refrigerant temperature sensor 38 Outside air temperature sensor 51 Indoor heat exchanger 200 Outdoor unit control part 210 CPU
220 Storage unit 240 Sensor input unit 300 Defrosting operation end condition table D Number of indoor units in operation Tc Outdoor heat exchange temperature during defrosting operation Ts Outdoor heat exchange temperature during heating operation Te Defrosting operation end temperature To Outside air temperature To1 First Outside temperature To2 Second outside temperature

Claims (2)

圧縮機と、四方弁と、室外熱交換器と、同室外熱交換器の温度である室外熱交温度を検出する室外熱交温度検出手段と、外気温度を検出する外気温度検出手段を有する室外機と、
室内熱交換器を有する複数台の室内機と、
前記圧縮機や前記四方弁を制御する制御手段と、
を有する空気調和装置であって、
前記制御手段は、
暖房運転中に前記室外熱交換器で発生した霜を溶かす除霜運転を行うとき、
前記除霜運転を開始する時点で暖房運転を行っている室内機の合計能力と、前記除霜運転を開始する時点で前記外気温度検出手段で検出した外気温度に応じて除霜運転終了温度を決定し、
前記除霜運転中に、前記室外熱交温度検出手段で検出した室外熱交温度を取り込み、取り込んだ同室外熱交温度が前記除霜運転終了温度より高くなれば、前記除霜運転を終了する、
ことを特徴とする空気調和装置。
Outdoor having a compressor, a four-way valve, an outdoor heat exchanger, an outdoor heat exchange temperature detecting means for detecting an outdoor heat exchange temperature that is the temperature of the outdoor heat exchanger, and an outdoor air temperature detecting means for detecting the outdoor air temperature Machine,
A plurality of indoor units having indoor heat exchangers;
Control means for controlling the compressor and the four-way valve;
An air conditioner comprising:
The control means includes
When performing defrosting operation to melt frost generated in the outdoor heat exchanger during heating operation,
The defrosting operation end temperature is determined according to the total capacity of the indoor units that are performing the heating operation at the time of starting the defrosting operation and the outside air temperature detected by the outside air temperature detecting means at the time of starting the defrosting operation. Decide
During the defrosting operation, the outdoor heat exchange temperature detected by the outdoor heat exchange temperature detecting means is captured, and if the captured outdoor heat exchange temperature becomes higher than the defrosting operation end temperature, the defrosting operation is terminated. ,
An air conditioner characterized by that.
前記合計能力が所定の前記閾合計能力より大きいときの除霜運転終了温度は、前記合計能力が前記閾合計能力より小さいときの除霜運転終了温度より高い温度であること、
を特徴とする請求項1に記載の空気調和装置。
The defrosting operation end temperature when the total capacity is greater than the predetermined threshold total capacity is higher than the defrosting operation end temperature when the total capacity is smaller than the threshold total capacity;
The air conditioning apparatus according to claim 1.
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Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN110260466A (en) * 2019-06-13 2019-09-20 珠海格力电器股份有限公司 air conditioner defrosting control method and device
CN110332653A (en) * 2019-07-10 2019-10-15 珠海格力电器股份有限公司 Outdoor unit defrosting control method, device and equipment
CN112484238A (en) * 2020-11-16 2021-03-12 珠海格力电器股份有限公司 Defrosting control method and device, multi-module unit and heating and ventilation equipment
CN114543185A (en) * 2022-02-16 2022-05-27 青岛海信日立空调系统有限公司 Air conditioning system

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2008215734A (en) * 2007-03-06 2008-09-18 Hitachi Appliances Inc Multi-type air conditioner
JP2010032063A (en) * 2008-07-25 2010-02-12 Daikin Ind Ltd Outdoor unit and heat pump device

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2008215734A (en) * 2007-03-06 2008-09-18 Hitachi Appliances Inc Multi-type air conditioner
JP2010032063A (en) * 2008-07-25 2010-02-12 Daikin Ind Ltd Outdoor unit and heat pump device

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN110260466A (en) * 2019-06-13 2019-09-20 珠海格力电器股份有限公司 air conditioner defrosting control method and device
CN110332653A (en) * 2019-07-10 2019-10-15 珠海格力电器股份有限公司 Outdoor unit defrosting control method, device and equipment
CN110332653B (en) * 2019-07-10 2020-07-24 珠海格力电器股份有限公司 Outdoor unit defrosting control method, device and equipment
CN112484238A (en) * 2020-11-16 2021-03-12 珠海格力电器股份有限公司 Defrosting control method and device, multi-module unit and heating and ventilation equipment
CN112484238B (en) * 2020-11-16 2021-11-23 珠海格力电器股份有限公司 Defrosting control method and device, multi-module unit and heating and ventilation equipment
CN114543185A (en) * 2022-02-16 2022-05-27 青岛海信日立空调系统有限公司 Air conditioning system
CN114543185B (en) * 2022-02-16 2023-09-26 青岛海信日立空调系统有限公司 Air conditioning system

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