JP2019116993A - Air conditioner - Google Patents

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JP2019116993A
JP2019116993A JP2017250547A JP2017250547A JP2019116993A JP 2019116993 A JP2019116993 A JP 2019116993A JP 2017250547 A JP2017250547 A JP 2017250547A JP 2017250547 A JP2017250547 A JP 2017250547A JP 2019116993 A JP2019116993 A JP 2019116993A
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outdoor
fan
heat exchanger
defrosting operation
amount
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光将 榎本
Mitsumasa Enomoto
光将 榎本
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Fujitsu General Ltd
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Fujitsu General Ltd
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Abstract

To provide an air conditioner capable of controlling a fan defrosting operation time to an optimum length.SOLUTION: A CPU 210 stops an outdoor fan 27, and executes a fan defrosting operation for defrosting an outdoor fan 27 by driving the outdoor fan 27 while making a refrigerant discharged from a compressor 21 direct to an outdoor heat exchanger 23, after termination of a heat exchange defrosting operation to make the refrigerant discharged from the compressor 21 direct to the outdoor heat exchanger 23 by switching a four-way valve 22, in a heating operation, and terminates the fan defrosting operation when a heat reception amount Hn as an estimation value of a heat amount applied to the outdoor fan 27 from the outdoor heat exchanger 23 becomes a necessary heat amount Ht or more as an estimated value of the heat amount necessary for melting frost generated on the outdoor fan 27 during the fan defrosting operation.SELECTED DRAWING: Figure 3

Description

本発明は、暖房運転時に逆サイクル除霜運転を行う空気調和機に関するものである。   The present invention relates to an air conditioner that performs reverse cycle defrosting operation during heating operation.

空気調和機は、外気温度が低いときに暖房運転が行われると、蒸発器として機能する室外熱交換器に霜が発生する。暖房運転において室外熱交換器に発生した霜は、逆サイクル除霜運転を行うことによって融かされる。その後、霜は室外熱交換器の下方に配置されている室外ユニットの底板を通じて、ドレン水として排出される。逆サイクル除霜運転を行うときは、空気調和機は、室外ファンを停止するとともに冷凍サイクルを暖房サイクルから冷房サイクルに切り替える。そして、空気調和機は圧縮機によって圧縮されて高温となった冷媒を室外熱交換器に流入させる。これにより、室外熱交換器が加熱されて、室外熱交換器に発生した霜が融かされる。   In the air conditioner, when the heating operation is performed when the outside air temperature is low, frost is generated in the outdoor heat exchanger functioning as an evaporator. The frost generated in the outdoor heat exchanger in the heating operation is melted by performing the reverse cycle defrosting operation. Thereafter, the frost is discharged as drain water through the bottom plate of the outdoor unit disposed below the outdoor heat exchanger. When performing reverse cycle defrosting operation, the air conditioner stops the outdoor fan and switches the refrigeration cycle from the heating cycle to the cooling cycle. Then, the air conditioner causes the refrigerant compressed by the compressor to have a high temperature to flow into the outdoor heat exchanger. Thereby, the outdoor heat exchanger is heated and the frost generated in the outdoor heat exchanger is melted.

ところで、外気温度が0℃付近で暖房運転を行うときは、室外熱交換器を通過した空気が0℃以下となって室外ファンに当たる。また、室外熱交換器に発生した霜によって室外熱交換器が目詰まりして空気が通らなくなると、吹出口から流入した室外熱交換器を通らない空気が室外ファンに当たる。これらにより、室外熱交換器だけでなく室外ファンにも霜が発生する場合がある。   By the way, when the heating operation is performed at the outside air temperature around 0 ° C., the air passing through the outdoor heat exchanger becomes 0 ° C. or less and hits the outdoor fan. In addition, when the outdoor heat exchanger is clogged by the frost generated in the outdoor heat exchanger and the air can not pass through, the air that does not pass through the outdoor heat exchanger that has flowed in from the outlet hits the outdoor fan. As a result, frost may be generated not only on the outdoor heat exchanger but also on the outdoor fan.

室外ファンに発生した霜は、室外ファンを停止させて実行する上述した逆サイクル除霜運転では融けない。そこで、室外ファンで発生した霜を融かすためにファン除霜運転を行う空気調和機が提案されている。例えば、特許文献1に示す空気調和機では、逆サイクル除霜運転を行って室外熱交換器の除霜を行った後に、圧縮機から吐出された冷媒が室外熱交換器に流入する状態のままで室外ファンを一定時間回転させることが記載されている。これにより、室外熱交換器で加熱された温かい空気を室外ファンに当てて、室外ファンで発生した霜を融かすことができる。   The frost generated in the outdoor fan can not be melted in the above-described reverse cycle defrosting operation performed by stopping the outdoor fan. Therefore, there has been proposed an air conditioner that performs a fan defrosting operation in order to melt the frost generated by the outdoor fan. For example, in the air conditioner shown in Patent Document 1, after performing reverse cycle defrosting operation and defrosting the outdoor heat exchanger, the refrigerant discharged from the compressor remains in the state of flowing into the outdoor heat exchanger It is described that the outdoor fan is rotated for a certain period of time. Thereby, warm air heated by the outdoor heat exchanger can be applied to the outdoor fan to melt the frost generated by the outdoor fan.

特開2010−121789号公報JP, 2010-121789, A

特許文献1に示す空気調和機では、室外熱交換器の除霜運転やファン除霜運転を予め定められた時間だけ行っていた。この時間は予め試験等により定められており、想定された室外ファンで発生する最大量の霜を完全に除去できるように設定された時間である。従って、実際に室外ファンで発生した霜の量が想定していた最大量より少ないと、室外ファンで発生した霜が融けきったにもかかわらずファン除霜運転を継続してしまい(いわゆる、空除霜運転)、暖房運転の再開時期を遅らせていた。   In the air conditioner shown in Patent Document 1, the defrosting operation and the fan defrosting operation of the outdoor heat exchanger are performed only for a predetermined time. This time is previously determined by a test or the like, and is a time set so as to completely remove the maximum amount of frost generated by the assumed outdoor fan. Therefore, if the amount of frost actually generated by the outdoor fan is smaller than the expected maximum amount, the fan defrosting operation is continued even though the frost generated by the outdoor fan is melted (so-called, empty) Defrosting operation) delayed the heating operation restart timing.

本発明は以上述べた問題点を解決するものであって、ファン除霜運転時間を最適な長さにすることができる空気調和機を提供することを目的とする。   An object of the present invention is to solve the above-mentioned problems, and it is an object of the present invention to provide an air conditioner capable of setting the fan defrosting operation time to an optimum length.

上記の課題を解決するために、本発明の空気調和機は、暖房運転時に、圧縮機、室内熱交換器、膨張弁、室外熱交換器の順で冷媒が循環する冷媒回路と、前記冷媒回路に備えられ、前記圧縮機から吐出された冷媒の流れる方向を切り替える流路切替手段と、前記室外熱交換器に送風する室外ファンと、外気温度を検出する外気温度検出手段を有し、前記暖房運転時に、前記室外ファンを停止させるとともに、前記流路切替手段を切り替えて前記圧縮機から吐出された冷媒を前記室外熱交換器に向かわせる熱交除霜運転と、前記熱交除霜運転が終了した後に、前記圧縮機から吐出された冷媒を前記室外熱交換器に向かわせたまま、前記室外ファンを駆動して同室外ファンを除霜するファン除霜運転を行う制御手段と、を有する。前記制御手段は、前記ファン除霜運転中、前記室外熱交換器から前記室外ファンに与えられた熱量の推定値である受熱量が、前記室外ファンで発生した霜を融かすために必要な熱量の推定値である必要熱量以上となったら前記ファン除霜運転を終了する。   In order to solve the above problems, the air conditioner according to the present invention comprises a refrigerant circuit in which a refrigerant circulates in the order of a compressor, an indoor heat exchanger, an expansion valve, and an outdoor heat exchanger during heating operation, and the refrigerant circuit And an outdoor fan for blowing air to the outdoor heat exchanger, and an outside air temperature detection means for detecting an outside air temperature, and During operation, the heat exchange defrosting operation for stopping the outdoor fan and switching the flow path switching means to direct the refrigerant discharged from the compressor to the outdoor heat exchanger, and the heat exchange defrosting operation And control means for performing a fan defrosting operation for driving the outdoor fan to defrost the outdoor fan while the refrigerant discharged from the compressor is directed to the outdoor heat exchanger after the completion. . In the fan defrosting operation, the control means is a heat amount required for the heat reception amount, which is an estimated value of the heat amount given from the outdoor heat exchanger to the outdoor fan, to melt the frost generated in the outdoor fan. The fan defrosting operation is ended when the required amount of heat, which is an estimated value of.

上記のように構成した本発明の空気調和機によれば、ファン除霜運転時に、室外ファンで発生した霜を融かすために必要な熱量を算出し、室外ファンが受けた熱量が必要な熱量以上となっていればファン除霜運転を終了させる。これにより、ファン除霜運転時間を最適な長さにすることができる。   According to the air conditioner of the present invention configured as described above, the amount of heat required to melt the frost generated by the outdoor fan during the fan defrosting operation is calculated, and the amount of heat received by the outdoor fan is required If it is above, the fan defrosting operation is ended. Thereby, fan defrosting operation time can be made into optimal length.

本発明の実施形態における、空気調和機の説明図であり、(A)は冷媒回路図、(B)は室外機制御手段のブロック図である。It is explanatory drawing of the air conditioner in embodiment of this invention, (A) is a refrigerant circuit figure, (B) is a block diagram of outdoor unit control means. 本発明の実施形態における、ファン除霜制御テーブルである。It is a fan defrost control table in embodiment of this invention. 本発明の実施形態における、熱交除霜運転時およびファン除霜運転時の室外機制御手段での処理を説明するフローチャートである。It is a flowchart explaining the process in the outdoor unit control means at the time of heat exchange defrost operation and fan defrost operation in an embodiment of the present 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、室外機と室内機が2本の冷媒配管で接続された空気調和機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。   Hereinafter, embodiments of the present invention will be described in detail based on the attached drawings. As an embodiment, an air conditioner in which an outdoor unit and an indoor unit are connected by two refrigerant pipes will be described as an example. The present invention is not limited to the following embodiments, and various modifications can be made without departing from the spirit 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機1は、屋外に設置される室外機2と、室内に設置され室外機2に液管4およびガス管5で接続された室内機3を備えている。詳細には、室外機2の閉鎖弁25と室内機3の液管接続部33が液管4で接続されている。また、室外機2の閉鎖弁26と室内機3のガス管接続部34がガス管5で接続されている。以上により、空気調和機1の冷媒回路10が形成される。   As shown in FIG. 1 (A), the air conditioner 1 in this embodiment includes an outdoor unit 2 installed outdoors, and an indoor unit installed indoors and connected to the outdoor unit 2 by a liquid pipe 4 and a gas pipe 5. The machine 3 is provided. In detail, the closing valve 25 of the outdoor unit 2 and the liquid pipe connection portion 33 of the indoor unit 3 are connected by the liquid pipe 4. Further, the closing valve 26 of the outdoor unit 2 and the gas pipe connection portion 34 of the indoor unit 3 are connected by the gas pipe 5. Thus, the refrigerant circuit 10 of the air conditioner 1 is formed.

<室外機の構成>
まずは、室外機2について説明する。室外機2は、圧縮機21と、四方弁22と、室外熱交換器23と、膨張弁24と、液管4が接続された閉鎖弁25と、ガス管5が接続された閉鎖弁26と、室外ファン27を備えている。そして、室外ファン27を除くこれら各装置が後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10aを形成している。
<Configuration of outdoor unit>
First, the outdoor unit 2 will be described. The outdoor unit 2 includes a compressor 21, a four-way valve 22, an outdoor heat exchanger 23, an expansion valve 24, a closing valve 25 to which the liquid pipe 4 is connected, and a closing valve 26 to which the gas pipe 5 is connected. The outdoor fan 27 is provided. Then, the respective units other than the outdoor fan 27 are mutually connected by respective refrigerant pipes to be described later to form an outdoor unit refrigerant circuit 10 a which forms a part of the refrigerant circuit 10.

圧縮機21は、図示しないインバータにより回転数が制御されることで、運転容量を変えることができる容量可変型圧縮機である。圧縮機21の冷媒吐出側は、四方弁22のポートaと吐出管61で接続されている。また、圧縮機21の冷媒吸入側は、四方弁22のポートcと吸入管66で接続されている。   The compressor 21 is a variable displacement compressor capable of changing the operating capacity by controlling the rotation speed by an inverter (not shown). The refrigerant discharge side of the compressor 21 is connected to a port a of the four-way valve 22 by a discharge pipe 61. The refrigerant suction side of the compressor 21 is connected to a port c of the four-way valve 22 by a suction pipe 66.

四方弁22は、冷媒の流れる方向を切り替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。ポートaは、上述したように圧縮機21の冷媒吐出側と吐出管61で接続されている。ポートbは、室外熱交換器23の一方の冷媒出入口と冷媒配管62で接続されている。ポートcは、上述したように圧縮機21の冷媒吸入側と吸入管66で接続されている。そして、ポートdは、閉鎖弁26と室外機ガス管64で接続されている。尚、四方弁22が、本発明の流路切替手段である。   The four-way valve 22 is a valve for switching the flow direction of the refrigerant, and has four ports a, b, c, d. The port a is connected to the refrigerant discharge side of the compressor 21 by the discharge pipe 61 as described above. The port b is connected to one refrigerant inlet / outlet of the outdoor heat exchanger 23 by a refrigerant pipe 62. The port c is connected to the refrigerant suction side of the compressor 21 by the suction pipe 66 as described above. The port d is connected to the closing valve 26 by the outdoor unit gas pipe 64. The four-way valve 22 is the flow channel switching means of the present invention.

室外熱交換器23は、冷媒と、後述する室外ファン27の回転により室外機2の内部に取り込まれた外気を熱交換させるものである。室外熱交換器23の一方の冷媒出入口は、上述したように四方弁22のポートbと冷媒配管62で接続され、他方の冷媒出入口は閉鎖弁25と室外機液管63で接続されている。室外熱交換器23は、後述する四方弁22の切り替えによって、冷房運転時は凝縮器として機能し、暖房運転時は蒸発器として機能する。   The outdoor heat exchanger 23 exchanges heat between the refrigerant and the outside air taken into the outdoor unit 2 by the rotation of the outdoor fan 27 described later. One refrigerant inlet / outlet of the outdoor heat exchanger 23 is connected with the port b of the four-way valve 22 by the refrigerant pipe 62 as described above, and the other refrigerant inlet / outlet is connected with the closing valve 25 by the outdoor unit liquid pipe 63. The outdoor heat exchanger 23 functions as a condenser during cooling operation and functions as an evaporator during heating operation by switching the four-way valve 22 described later.

膨張弁24は、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る。具体的には、パルスモータに加えられるパルス数によりその開度が調整される。膨張弁24は、暖房運転時は圧縮機21から吐出される冷媒の温度である吐出温度が所定の目標温度となるように、その開度が調整される。また、膨張弁24は、冷房運転時は凝縮器として機能する後述する室内熱交換器31の冷媒出口側における冷媒過冷却度が所定の目標過冷却度となるように、その開度が調整される。   The expansion valve 24 is an electronic expansion valve driven by a pulse motor (not shown). Specifically, the degree of opening is adjusted by the number of pulses applied to the pulse motor. The degree of opening of the expansion valve 24 is adjusted such that the discharge temperature, which is the temperature of the refrigerant discharged from the compressor 21 during the heating operation, becomes a predetermined target temperature. Further, the degree of opening of expansion valve 24 is adjusted such that the degree of refrigerant supercooling on the refrigerant outlet side of indoor heat exchanger 31 described later, which functions as a condenser, during cooling operation becomes a predetermined target degree of subcooling. Ru.

室外ファン27は樹脂材で形成されており、室外熱交換器23の近傍に配置されている。室外ファン27は、その中心部がファンモータ27aの図示しない回転軸に接続されている。ファンモータ27aが回転することで室外ファン27が回転する。室外ファン27の回転によって、室外機2の図示しない吸込口から室外機2の内部へ外気を取り込み、室外熱交換器23において冷媒と熱交換した外気を、室外機2の図示しない吹出口から室外機2外部へ放出する。   The outdoor fan 27 is formed of a resin material and disposed in the vicinity of the outdoor heat exchanger 23. A central portion of the outdoor fan 27 is connected to a rotating shaft (not shown) of the fan motor 27a. The outdoor fan 27 rotates as the fan motor 27a rotates. By the rotation of the outdoor fan 27, outside air is taken into the interior of the outdoor unit 2 from a suction port (not shown) of the outdoor unit 2 and heat exchange is performed with the refrigerant in the outdoor heat exchanger 23 Release to the outside of machine 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61には、圧縮機21から吐出される冷媒の圧力を検出する吐出圧力センサ71と、圧縮機21から吐出される冷媒の温度(上述した吐出温度)を検出する吐出温度センサ73が設けられている。吸入管66には、圧縮機21に吸入される冷媒の圧力を検出する吸入圧力センサ72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74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, the discharge pipe 61 is provided with a discharge pressure sensor 71 for detecting the pressure of the refrigerant discharged from the compressor 21 and the temperature of the refrigerant discharged from the compressor 21 (the discharge temperature described above A discharge temperature sensor 73 is provided to detect. The suction pipe 66 is provided with a suction pressure sensor 72 for detecting the pressure of the refrigerant sucked into the compressor 21 and a suction temperature sensor 74 for detecting the temperature of the refrigerant sucked into the compressor 21.

室外熱交換器23の図示しない冷媒パスの略中間部には、室外熱交換器23の温度である室外熱交温度を検出する熱交温度センサ75が設けられている。そして、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センサ76が備えられている。   A heat exchange temperature sensor 75 for detecting an outdoor heat exchange temperature, which is a temperature of the outdoor heat exchanger 23, is provided at a substantially middle portion of a refrigerant path (not shown) of the outdoor heat exchanger 23. Then, near the suction port (not shown) of the outdoor unit 2, an outside air temperature sensor 76 is provided which detects the temperature of the outside air flowing into the interior of the outdoor unit 2, that is, the outside air temperature.

また、室外機2には、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ている制御基板に搭載されている。図1(B)に示すように、室外機制御手段200は、CPU210と、記憶部220と、通信部230と、センサ入力部240を備えている。   In addition, the outdoor unit 2 is provided with an outdoor unit control means 200. The outdoor unit control means 200 is mounted on a control board stored in an electric component box (not shown) of the outdoor unit 2. As shown in FIG. 1B, the outdoor unit control means 200 includes a CPU 210, a storage unit 220, a communication unit 230, and a sensor input unit 240.

記憶部220は、フラッシュメモリで構成されており、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27等の制御状態等を記憶している。また、図示は省略するが、記憶部220には室内機3から受信する要求能力に応じて圧縮機21の回転数を定めた回転数テーブルが予め記憶されている。   The storage unit 220 is configured by a flash memory, and stores detection values corresponding to control programs of the outdoor unit 2 and detection signals from various sensors, control states of the compressor 21 and the outdoor fan 27, and the like. Moreover, although illustration is abbreviate | omitted, the rotation speed table which defined the rotation speed of the compressor 21 according to the request | requirement capability received from the indoor unit 3 is stored beforehand by the memory | storage part 220. FIG.

通信部230は、室内機3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 communication unit 230 is an interface that communicates with the indoor unit 3. The sensor input unit 240 takes in detection results of various sensors of the outdoor unit 2 and outputs the detection results to the CPU 210.

CPU210は、前述した室外機2の各センサでの検出結果を、センサ入力部240を介して取り込む。さらには、CPU210は、室内機3から送信される制御信号を、通信部230を介して取り込む。CPU210は、取り込んだ検出結果や制御信号等に基づいて、圧縮機21や室外ファン27の駆動制御を行う。また、CPU210は、取り込んだ検出結果や制御信号に基づいて、四方弁22の切り替え制御を行う。さらには、CPU210は、取り込んだ検出結果や制御信号に基づいて、膨張弁24の開度調整を行う。   The CPU 210 takes in the detection result of each sensor of the outdoor unit 2 described above via the sensor input unit 240. Furthermore, the CPU 210 takes in a control signal transmitted from the indoor unit 3 via the communication unit 230. The CPU 210 performs drive control of the compressor 21 and the outdoor fan 27 based on the captured detection result, control signal, and the like. The CPU 210 also performs switching control of the four-way valve 22 based on the captured detection result and control signal. Furthermore, the CPU 210 adjusts the opening degree of the expansion valve 24 based on the captured detection result and control signal.

<室内機の構成>
次に、図1(A)を用いて、室内機3について説明する。室内機3は、室内熱交換器31と、室内ファン32と、液管4の他端が接続された液管接続部33と、ガス管5の他端が接続されたガス管接続部34を備えている。そして、室内ファン32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の一部をなす室内機冷媒回路10bを形成している。
<Configuration of indoor unit>
Next, the indoor unit 3 will be described with reference to FIG. The indoor unit 3 includes an indoor heat exchanger 31, an indoor fan 32, a liquid pipe connecting portion 33 to which the other end of the liquid pipe 4 is connected, and a gas pipe connecting portion 34 to which the other end of the gas pipe 5 is connected. Have. Then, the respective units other than the indoor fan 32 are mutually connected by respective refrigerant pipes which will be described in detail below to form the indoor unit refrigerant circuit 10b which forms a part of the refrigerant circuit 10.

室内熱交換器31は、冷媒と後述する室内ファン32の回転により室内機3の図示しない吸込口から室内機3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31の一方の冷媒出入口は、液管接続部33と室内機液管67で接続されている。室内熱交換器31の他方の冷媒出入口は、ガス管接続部34と室内機ガス管68で接続されている。室内熱交換器31は、室内機3が冷房運転を行う場合は蒸発器として機能し、室内機3が暖房運転を行う場合は凝縮器として機能する。尚、液管接続部33やガス管接続部34では、各冷媒配管が溶接やフレアナット等により接続されている。   The indoor heat exchanger 31 exchanges heat between the refrigerant and indoor air taken into the interior of the indoor unit 3 from a suction port (not shown) of the indoor unit 3 by rotation of the indoor fan 32 described later. One refrigerant inlet / outlet of the indoor heat exchanger 31 is connected to the liquid pipe connection portion 33 by an indoor unit liquid pipe 67. The other refrigerant inlet / outlet of the indoor heat exchanger 31 is connected to the gas pipe connection portion 34 by an indoor unit gas pipe 68. The indoor heat exchanger 31 functions as an evaporator when the indoor unit 3 performs the cooling operation, and functions as a condenser when the indoor unit 3 performs the heating operation. In the liquid pipe connection portion 33 and the gas pipe connection portion 34, respective refrigerant pipes are connected by welding, a flare nut or the like.

室内ファン32は樹脂材で形成されており、室内熱交換器31の近傍に配置されている。室内ファン32は、図示しないファンモータによって回転することで、室内機3の図示しない吸込口から室内機3の内部に室内空気を取り込み、室内熱交換器31において冷媒と熱交換した室内空気を室内機3の図示しない吹出口から室内へ吹き出す。   The indoor fan 32 is formed of a resin material and disposed in the vicinity of the indoor heat exchanger 31. The indoor fan 32 is rotated by a fan motor (not shown) to take in indoor air from the suction port (not shown) of the indoor unit 3 into the interior of the indoor unit 3, and heats room air exchanged with refrigerant in the indoor heat exchanger 31. The air is blown out into the room from the air outlet of the machine 3 (not shown).

以上説明した構成の他に、室内機3には各種のセンサが設けられている。室内機液管67には、室内熱交換器31に流入あるいは室内熱交換器31から流出する冷媒の温度を検出する液側温度センサ77が設けられている。室内機ガス管68には、室内熱交換器31から流出あるいは室内熱交換器31に流入する冷媒の温度を検出するガス側温度センサ78が設けられている。そして、室内機3の図示しない吸込口付近には、室内機3の内部に流入する室内空気の温度、すなわち室温を検出する室温センサ79が備えられている。   In addition to the configuration described above, the indoor unit 3 is provided with various sensors. The indoor unit liquid pipe 67 is provided with a liquid side temperature sensor 77 for detecting the temperature of the refrigerant flowing into the indoor heat exchanger 31 or flowing out from the indoor heat exchanger 31. The indoor unit gas pipe 68 is provided with a gas side temperature sensor 78 for detecting the temperature of the refrigerant flowing out of the indoor heat exchanger 31 or flowing into the indoor heat exchanger 31. A room temperature sensor 79 for detecting the temperature of room air flowing into the interior of the indoor unit 3, that is, the room temperature, is provided in the vicinity of a suction port (not shown) of the indoor unit 3.

<冷媒回路の動作>
次に、本実施形態における空気調和機1の空調運転時の冷媒回路10における冷媒の流れや各部の動作について、図1(A)を用いて説明する。以下の説明では、まず、室内機3が暖房運転を行う場合について説明し、次に、冷房運転を行う場合について説明する。そして、室外熱交換器23で発生した霜を溶かす熱交除霜運転と、室外ファン27で発生した霜を溶かすファン除霜運転からなる除霜運転を行う場合について説明する。
<Operation of refrigerant circuit>
Next, the flow of the refrigerant in the refrigerant circuit 10 at the time of the air conditioning operation of the air conditioner 1 in the present embodiment and the operation of each part will be described with reference to FIG. In the following description, first, the case where the indoor unit 3 performs the heating operation will be described, and then, the case where the cooling operation is performed will be described. A heat removal defrosting operation for melting the frost generated in the outdoor heat exchanger 23 and a defrosting operation including the fan defrosting operation for melting the frost generated in the outdoor fan 27 will be described.

<暖房運転>
室内機3が暖房運転を行う場合、CPU210は、図1(A)に示すように四方弁22を実線で示す状態、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、また、ポートbとポートcが連通するよう、切り替える。これにより、冷媒回路10において実線矢印で示す方向に冷媒が循環し、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31が凝縮器として機能する暖房サイクルとなる。
<Heating operation>
When the indoor unit 3 performs the heating operation, as shown in FIG. 1A, the CPU 210 shows a state in which the four-way valve 22 is indicated by a solid line, that is, port a and port d of the four-way valve 22 communicate with each other. Switch so that b and port c communicate. Thus, the refrigerant circulates in the direction indicated by the solid line arrow in the refrigerant circuit 10, and the outdoor heat exchanger 23 functions as an evaporator, and the indoor heat exchanger 31 functions as a condenser as a heating cycle.

圧縮機21から吐出された高圧の冷媒は、吐出管61を流れて四方弁22に流入し、四方弁22から室外機ガス管64を流れて、閉鎖弁26を介してガス管5に流入する。ガス管5を流れる冷媒は、ガス管接続部34を介して室内機3に流入する。   The high-pressure refrigerant discharged from the compressor 21 flows through the discharge pipe 61 and flows into the four-way valve 22, flows from the four-way valve 22 through the outdoor unit gas pipe 64, and flows into the gas pipe 5 via the closing valve 26. . The refrigerant flowing through the gas pipe 5 flows into the indoor unit 3 through the gas pipe connection portion 34.

室内機3に流入した冷媒は、室内機ガス管68を流れて室内熱交換器31に流入し、室内ファン32の回転により室内機3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。このように、室内熱交換器31が凝縮器として機能し、室内熱交換器31で冷媒と熱交換を行った室内空気が図示しない吹出口から室内に吹き出されることによって、室内機3が設置された室内の暖房が行われる。   The refrigerant flowing into the indoor unit 3 flows through the indoor unit gas pipe 68, flows into the indoor heat exchanger 31, and exchanges heat with the indoor air taken into the interior of the indoor unit 3 by the rotation of the indoor fan 32 to condense Do. Thus, the indoor unit 3 is installed by the indoor heat exchanger 31 functioning as a condenser, and the indoor air heat-exchanged with the refrigerant in the indoor heat exchanger 31 is blown out into the room from an outlet (not shown). The room is heated.

室内熱交換器31から流出した冷媒は、室内機液管67を流れ、液管接続部33を介して液管4に流入する。液管4を流れ、閉鎖弁25を介して室外機2に流入した冷媒は、室外機液管63を流れて膨張弁24を通過する際に減圧される。上述したように、暖房運転時の膨張弁24の開度は、圧縮機21の吐出温度が所定の目標温度となるように調整される。   The refrigerant flowing out of the indoor heat exchanger 31 flows through the indoor machine liquid pipe 67 and flows into the liquid pipe 4 through the liquid pipe connection portion 33. The refrigerant flowing through the liquid pipe 4 and flowing into the outdoor unit 2 via the closing valve 25 is decompressed when flowing through the outdoor unit liquid pipe 63 and passing through the expansion valve 24. As described above, the opening degree of the expansion valve 24 during the heating operation is adjusted so that the discharge temperature of the compressor 21 becomes the predetermined target temperature.

膨張弁24を通過して室外熱交換器23に流入した冷媒は、室外ファン27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。室外熱交換器23から冷媒配管62に流出した冷媒は、四方弁22、吸入管66を流れ、圧縮機21に吸入されて再び圧縮される。   The refrigerant passing through the expansion valve 24 and flowing into the outdoor heat exchanger 23 exchanges heat with the outside air taken into the interior of the outdoor unit 2 by the rotation of the outdoor fan 27 and evaporates. The refrigerant that has flowed out of the outdoor heat exchanger 23 into the refrigerant pipe 62 flows through the four-way valve 22 and the suction pipe 66, and is drawn into the compressor 21 and compressed again.

<冷房運転>
室内機3が冷房運転あるいは除霜運転を行う場合、CPU210は、図1(A)に示すように四方弁22を破線で示す状態、すなわち、四方弁22のポートaとポートbとが連通するよう、また、ポートcとポートdとが連通するよう、切り替える。これにより、冷媒回路10において破線矢印で示す方向に冷媒が循環し、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31が蒸発器として機能する冷房サイクルとなる。
<Cooling operation>
When the indoor unit 3 performs the cooling operation or the defrosting operation, the CPU 210 shows a state in which the four-way valve 22 is indicated by a broken line as shown in FIG. 1A, that is, the port a and the port b of the four-way valve 22 communicate. Also, the ports c and d are switched so as to communicate with each other. As a result, the refrigerant circulates in the direction indicated by the broken line arrow in the refrigerant circuit 10, and the outdoor heat exchanger 23 functions as a condenser and the indoor heat exchanger 31 functions as an evaporator.

圧縮機21から吐出された高圧の冷媒は、吐出管61を流れて四方弁22に流入し、四方弁22から冷媒配管62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27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。   The high-pressure refrigerant discharged from the compressor 21 flows through the discharge pipe 61 and flows into the four-way valve 22, and flows from the four-way valve 22 through the refrigerant pipe 62 and flows into the outdoor heat exchanger 23. The refrigerant flowing into the outdoor heat exchanger 23 exchanges heat with the outside air taken into the interior of the outdoor unit 2 by the rotation of the outdoor fan 27 and condenses.

室外熱交換器23から流出した冷媒は室外機液管63を流れ、膨張弁24を通過する際に減圧される。上述したように、冷房運転時の膨張弁24の開度は、凝縮器として機能する室内熱交換器31の冷媒出口側における冷媒過冷却度が所定の目標過冷却度となるように、調整される。   The refrigerant flowing out of the outdoor heat exchanger 23 flows through the outdoor unit liquid pipe 63 and is decompressed when passing through the expansion valve 24. As described above, the opening degree of the expansion valve 24 during the cooling operation is adjusted so that the degree of refrigerant supercooling on the refrigerant outlet side of the indoor heat exchanger 31 functioning as a condenser becomes a predetermined target degree of subcooling. Ru.

膨張弁24を通過した冷媒は、閉鎖弁25を介して液管4に流出する。液管4を流れ、液管接続部33を介して室内機3に流入した冷媒は、室内機液管67を流れて室内熱交換器31に流入する。   The refrigerant that has passed through the expansion valve 24 flows out to the liquid pipe 4 via the closing valve 25. The refrigerant flowing through the liquid pipe 4 and flowing into the indoor unit 3 through the liquid pipe connection portion 33 flows through the indoor machine liquid pipe 67 and flows into the indoor heat exchanger 31.

室内熱交換器31に流入した冷媒は、室内ファン32の回転により室内機3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31が蒸発器として機能し、冷房運転の場合は、室内熱交換器31で冷媒と熱交換を行った室内空気が図示しない吹出口から室内に吹き出されることによって、室内機3が設置された室内の冷房が行われる。   The refrigerant flowing into the indoor heat exchanger 31 exchanges heat with the indoor air taken into the interior of the indoor unit 3 by the rotation of the indoor fan 32 and evaporates. As described above, the indoor heat exchanger 31 functions as an evaporator, and in the case of the cooling operation, the indoor air heat-exchanged with the refrigerant in the indoor heat exchanger 31 is blown out into the room from the outlet (not shown). Cooling of the room in which the indoor unit 3 is installed is performed.

室内熱交換器31から流出した冷媒は、室内機ガス管68を流れ、ガス管接続部34を介してガス管5に流出する。ガス管5を流れる冷媒は、閉鎖弁26を介して室外機2に流入し、室外機ガス管64、四方弁22、吸入管66の順に流れ、圧縮機21に吸入されて再び圧縮される。   The refrigerant flowing out of the indoor heat exchanger 31 flows through the indoor unit gas pipe 68 and flows out to the gas pipe 5 via the gas pipe connection portion 34. The refrigerant flowing through the gas pipe 5 flows into the outdoor unit 2 through the closing valve 26, flows through the outdoor unit gas pipe 64, the four-way valve 22, and the suction pipe 66 in this order, and is sucked into the compressor 21 and compressed again.

<除霜運転>
除霜運転は、室外熱交換器23に発生した霜を融かす熱交除霜運転と、室外ファン27で発生した霜を融かすファン除霜運転で構成されている。熱交除霜運転では、冷媒回路10が前述した冷房サイクルとされ、室外ファン27を停止させた状態で圧縮機21から吐出される高温の冷媒を室外熱交換器23に流すことで、室外熱交換器23に発生した霜を融かす。また、ファン除霜運転は、後述する所定の条件が成立した場合に、熱交除霜運転に引き続いて行われる運転である。ファン除霜運転では、冷媒回路10が熱交除霜運転と同じ冷房サイクルのままで室外ファン27を駆動するとともに、後述するファン回転数調整制御テーブル300を用いて、圧縮機21と室内ファン32と膨張弁24の各々が制御される。
<Defrosting operation>
The defrosting operation is composed of a heat exchange defrosting operation for melting the frost generated in the outdoor heat exchanger 23 and a fan defrosting operation for melting the frost generated in the outdoor fan 27. In the heat exchange defrosting operation, the refrigerant circuit 10 is in the cooling cycle described above, and the high temperature refrigerant discharged from the compressor 21 is allowed to flow to the outdoor heat exchanger 23 in a state in which the outdoor fan 27 is stopped. The frost generated in the exchanger 23 is melted. Further, the fan defrosting operation is an operation performed subsequently to the heat exchange defrosting operation when a predetermined condition described later is satisfied. In the fan defrosting operation, the refrigerant circuit 10 drives the outdoor fan 27 with the same cooling cycle as the heat exchange defrosting operation, and the compressor 21 and the indoor fan 32 are controlled using the fan rotational speed adjustment control table 300 described later. And each of the expansion valves 24 are controlled.

以下の説明では、まずは、ファン除霜運転の終了時期を判断するための熱量の算出及び設定方法について説明する。次に、ファン除霜運転中に室外ファン27の回転数を調整する際に使用するファン回転数調整制御テーブル300について、図2を用いて説明する。そして、除霜運転時に室外機制御手段200のCPU210が行う処理の流れについて、図3を用いて説明する。尚、以下の説明では、ファン除霜運転時の室外ファン27で発生した霜を完全に融かすために必要な熱量の推定値である必要熱量をHt(単位:J)、ファン除霜運転時の室外ファン27が室外熱交換器23から受ける熱量の推定値である受熱量をHn(単位:J)、ファン除霜運転時の室外熱交換器23の温度である室外熱交温度をTc(単位:℃)、ファン除霜運転時の室外熱交換器23の目標温度である目標室外熱交温度をTct(単位:℃)、ファン除霜運転時の圧縮機21の回転数をRc(単位:rps)、ファン除霜運転時の室外ファン27の回転数をRfo(単位:rpm)とする。   In the following description, first, a method of calculating and setting the amount of heat for determining the end time of the fan defrosting operation will be described. Next, a fan rotation number adjustment control table 300 used when adjusting the rotation number of the outdoor fan 27 during the fan defrosting operation will be described with reference to FIG. And the flow of the processing which CPU210 of outdoor unit control means 200 performs at the time of defrosting operation is explained using FIG. In the following description, the necessary heat quantity, which is an estimated value of the heat quantity necessary to completely melt the frost generated by the outdoor fan 27 during the fan defrosting operation, is Ht (unit: J), during the fan defrosting operation Hn (unit: J), which is an estimated value of the amount of heat received by the outdoor fan 27 from the outdoor heat exchanger 23, Hc (unit: J), Tc (the outdoor heat exchange temperature which is the temperature of the outdoor heat exchanger 23 during the fan defrosting operation) Unit: ° C., target outdoor heat exchange temperature which is the target temperature of the outdoor heat exchanger 23 at the time of fan defrosting operation Tct (unit: ° C.), Rc of the rotational speed of the compressor 21 at the time of fan defrosting operation : Rps), The rotational speed of the outdoor fan 27 at the time of fan defrosting operation is Rfo (unit: rpm).

<熱量の算出・設定方法について>
ファン除霜運転時、室外熱交換器23で加熱された温かい空気は室外ファン27に当てられて、室外ファン27に発生した霜を融かす。すなわち、室外熱交換器23の持つ熱量が室外ファン27に発生した霜の融解に影響を与える。室外ファン27が室外熱交換器23から受けた熱量である受熱量Hnが、室外ファン27に発生した霜を完全に融かすために必要な熱量である必要熱量Ht以上となれば、室外ファン27に発生した全ての霜が融けたと推定することができる。
<How to calculate and set the amount of heat>
During the fan defrosting operation, the warm air heated by the outdoor heat exchanger 23 is applied to the outdoor fan 27 and melts the frost generated on the outdoor fan 27. That is, the heat amount of the outdoor heat exchanger 23 affects the melting of the frost generated in the outdoor fan 27. If the amount of received heat Hn, which is the amount of heat received by the outdoor fan 27 from the outdoor heat exchanger 23, is equal to or greater than the amount of necessary heat Ht necessary to completely melt the frost generated in the outdoor fan 27, the outdoor fan 27 It can be inferred that all the frost generated on the surface has melted.

必要熱量Htは室外ファン27で発生した霜を完全に融かすために必要な熱量の推定値である。室外ファン27で発生する霜の量は、構造的要因と環境的要因から推定できる。構造的要因として、室外ファン27で発生する霜の量は、室外ファン27の大きさや、室外熱交換器23及び室外機2筐体内の通風抵抗によって異なる。具体的には、室外ファン27の径が大きい程室外ファン27の表面積が大きくなるため、室外ファン27で発生する霜の量は多くなる。また、室外熱交換器23及び室外機2筐体内の通風路(図示しない吸込口と図示しない吹出口を筐体内で接続する通路であって、同通風路内に室外熱交換器23及び室外ファン27が設けられている)通風抵抗が小さい程室外熱交換器23及び室外機筐体内で発生する霜の量が少なくなる。すなわち、外気が筐体外から室外ファン27に至るまでに室外熱交換器23及び室外機筐体内で発生する霜の量が少なくなれば水分を多く含んだ状態のままの空気が室外ファン27に到達しやすくなるため、室外ファン27で発生する霜の量は多くなる。   The required heat amount Ht is an estimated value of the heat amount required to completely melt the frost generated by the outdoor fan 27. The amount of frost generated by the outdoor fan 27 can be estimated from structural factors and environmental factors. As a structural factor, the amount of frost generated by the outdoor fan 27 varies depending on the size of the outdoor fan 27 and the ventilation resistance in the outdoor heat exchanger 23 and the outdoor unit 2 casing. Specifically, since the surface area of the outdoor fan 27 increases as the diameter of the outdoor fan 27 increases, the amount of frost generated by the outdoor fan 27 increases. In addition, an outdoor heat exchanger 23 and an air passage in the outdoor unit 2 casing (a passage connecting an air inlet not shown and an air outlet not shown in the enclosure, the outdoor heat exchanger 23 and the outdoor fan in the air passage As the ventilation resistance decreases, the amount of frost generated in the outdoor heat exchanger 23 and the outdoor unit casing decreases. That is, if the amount of frost generated in the outdoor heat exchanger 23 and the outdoor unit casing from the outside of the housing to the outdoor fan 27 decreases, the air still containing a large amount of water reaches the outdoor fan 27 Since it becomes easy to do, the quantity of the frost generated with outdoor fan 27 increases.

他方、環境的要因として、室外ファン27で発生する霜の量は、ファン除霜運転開始時の外気温度や直前の暖房運転時の除霜運転開始条件によって変動する。具体的には、外気温度が低い程、霜の量は多くなる。除霜運転開始条件とは、具体的な例としては、暖房運転時間(空気調和機1を暖房運転で起動した時点、あるいは、除霜運転から暖房運転に復帰した時点から暖房運転を継続している時間)が30分以上経過した後で、かつ、熱交温度センサ75で検出した室外熱交温度Tcが外気温度センサ76で検出した外気温度よりも5℃以上低い状態が、10分以上継続した場合(以下、「温度条件」とする)と、前回の除霜運転が終了してから所定時間(例:180分)が経過した場合(以下、「時間条件」とする)の二つの条件がある。室外機制御手段200のCPU210は、除霜運転開始条件の「温度条件」または「時間条件」のいずれかが成立すれば除霜運転を開始する。直前の暖房運転時の除霜運転開始条件が「時間条件」の場合は室外熱交温度Tcによらず所定時間が経過すれば成立するため、霜の量が少ない場合も考えられる。したがって、直前の暖房運転時の除霜運転開始条件が「時間条件」の場合は室外ファン27で発生する霜の量が少なく、「温度条件」の場合は霜の量が多くなると推定できる。   On the other hand, as an environmental factor, the amount of frost generated by the outdoor fan 27 varies depending on the outside air temperature at the start of the fan defrosting operation and the defrosting operation start condition at the immediately preceding heating operation. Specifically, as the outside air temperature is lower, the amount of frost increases. As a specific example, the defrosting operation start condition is the heating operation time (the heating operation is continued from the time when the air conditioner 1 is started in the heating operation or the time when the defrosting operation is restored to the heating operation) Time has passed 30 minutes or more, and the state where the outdoor heat exchange temperature Tc detected by the heat exchange temperature sensor 75 is 5 ° C. or more lower than the outside air temperature detected by the outside air temperature sensor 76 continues for 10 minutes or more Case (hereinafter referred to as “temperature condition”) and two conditions (hereinafter referred to as “time condition”) when a predetermined time (for example, 180 minutes) has elapsed since the last defrost operation ended There is. The CPU 210 of the outdoor unit control means 200 starts the defrosting operation if either the "temperature condition" or the "time condition" of the defrosting operation start condition is satisfied. In the case where the defrosting operation start condition at the time of the heating operation immediately before is “time condition”, the condition is satisfied regardless of the outdoor heat exchange temperature Tc and a predetermined time elapses. Therefore, it can be estimated that the amount of frost generated by the outdoor fan 27 is small when the defrosting operation start condition at the time of the heating operation immediately before is “time condition” and the amount of frost is large when “temperature condition”.

必要熱量Htは、予め試験などを行って求められて、環境的要因に応じた必要熱量Htが定められた図示しないテーブルとして室外機制御手段200の記憶部220に記憶される。また、室外機2の機種の大きさや形状によって構造的要因が異なってくるため、機種毎に予め試験などを行って、その機種の構造的要因に対応させたテーブルが夫々作成されているものとする。   The required heat amount Ht is obtained by conducting a test in advance, and is stored in the storage unit 220 of the outdoor unit control means 200 as a table (not shown) in which the required heat amount Ht corresponding to the environmental factor is determined. In addition, since structural factors differ depending on the size and shape of the model of the outdoor unit 2, each table is tested in advance, and tables corresponding to the structural factors of the model are prepared. Do.

例えば、室外機制御手段200のCPU210が、直前の暖房運転時に外気温度センサ76で検出する外気温度を取り込み、記憶部220に記憶する。また、室外機制御手段200のCPU210は、直前の暖房運転時の除霜運転開始条件成立時に除霜運転開始条件が「温度条件」か「時間条件」のどちらであったかを記憶部220に記憶する。テーブルでは、外気温度が低い程必要熱量Htを大きく設定している。また、除霜運転開始条件が「時間条件」の場合と比べて「温度条件」の場合に必要熱量Htを大きく設定している。これにより、室外ファン27で実際に発生した霜の量に対応した必要熱量Htを設定できる。なお、本実施形態では、図示しないテーブルを用いて前述した構造的要因と環境的要因から必要熱量Htを設定しているが、構造的要因と環境的要因から必要熱量Htを設定する方法であればこの限りでない。例えば、構造的要因に応じた「熱量」が定められたテーブルと環境的要因に応じた「補正値」が定められたテーブルを夫々記憶部220し、当該「熱量」と「補正値」との積で必要熱量Htを推定するようにしても良い。   For example, the CPU 210 of the outdoor unit control means 200 takes in the outside air temperature detected by the outside air temperature sensor 76 at the time of the last heating operation, and stores the outside air temperature in the storage unit 220. Further, the CPU 210 of the outdoor unit control means 200 stores in the storage unit 220 whether the defrosting operation start condition is the “temperature condition” or the “time condition” when the defrosting operation start condition is satisfied at the previous heating operation. . In the table, the required heat quantity Ht is set larger as the outside air temperature is lower. Further, the required heat amount Ht is set larger when the defrosting operation start condition is the "temperature condition" than when the defrosting operation start condition is the "time condition". Thereby, the required heat amount Ht corresponding to the amount of frost actually generated by the outdoor fan 27 can be set. In the present embodiment, the necessary heat quantity Ht is set based on the structural factor and the environmental factor described above using a table (not shown), but it is a method of setting the necessary heat quantity Ht based on the structural factor and the environmental factor It is not this limitation. For example, the storage unit 220 stores a table in which the "heat amount" corresponding to the structural factor is determined and a table in which the "correction value" is determined according to the environmental factor. The required heat amount Ht may be estimated by the product.

受熱量Hnはファン除霜運転時の室外ファン27が室外熱交換器23から受ける熱量の推定値であり、受熱量Hnは、室外熱交温度Tcと構造的・環境的要因及びファン除霜運転開始時を起点とした室外ファン27の回転数(単位時間当たりの回転数ではなく実際の回転数の積算値)から推定できる。構造的要因として、受熱量Hnは、室外ファン27又は室外熱交換器23の性能や、室外機2筐体構造によって異なる。具体的には、室外ファン27の一回転当たりの風量が大きければ受熱量Hnは高くなる。また、室外熱交換器23の冷媒−空気間の熱交換性能が高ければ受熱量Hnは高くなる。また、室外機2の筐体外から室外熱交換器23を通過しないで室外ファン27に吸い込まれる空気(例えば、室外機2の図示しない底板に設けられた排水用の孔を介して吸い込まれた空気)の量が少なければ受熱量Hnは高くなる。また、室外ファン27と室外熱交換器23の間の距離が短ければ受熱量Hnは高くなる。   The amount of heat received Hn is an estimated value of the amount of heat received from the outdoor heat exchanger 23 by the outdoor fan 27 at the time of fan defrosting operation, and the amount of heat received Hn corresponds to the outdoor heat exchange temperature Tc, structural and environmental factors, and fan defrosting operation It can be estimated from the number of revolutions of the outdoor fan 27 starting from the start time (not the number of revolutions per unit time but an integrated value of the actual number of revolutions). As a structural factor, the received heat amount Hn differs depending on the performance of the outdoor fan 27 or the outdoor heat exchanger 23 and the structure of the outdoor unit 2 casing. Specifically, if the air volume per one rotation of the outdoor fan 27 is large, the received heat amount Hn becomes high. Further, if the heat exchange performance between the refrigerant and air of the outdoor heat exchanger 23 is high, the received heat amount Hn becomes high. Further, air sucked into the outdoor fan 27 without passing through the outdoor heat exchanger 23 from the outside of the casing of the outdoor unit 2 (for example, air sucked through a drainage hole provided in a bottom plate (not shown) of the outdoor unit 2) If the amount of) is small, the amount of heat received Hn will be high. Further, if the distance between the outdoor fan 27 and the outdoor heat exchanger 23 is short, the received heat amount Hn becomes high.

他方、環境的要因として、受熱量Hnは、外気温度や室外ファン27の風量によって変動する。具体的には、外気温度が高ければ受熱量Hnは高くなる。また、室外ファン27の回転数(風量)が大きければ受熱量Hnは高くなる。   On the other hand, as an environmental factor, the received heat amount Hn fluctuates depending on the outside air temperature and the air volume of the outdoor fan 27. Specifically, if the outside air temperature is high, the received heat amount Hn becomes high. Further, if the rotation speed (air volume) of the outdoor fan 27 is large, the received heat amount Hn becomes high.

受熱量Hnは、予め試験などを行って求められて、室外熱交温度Tcと環境的要因に応じた受熱量Hnが定められた図示しないテーブルとして室外機制御手段200の記憶部220に記憶される。また、室外機2の機種の大きさや形状によって構造的要因が異なってくるため、機種毎に予め試験などを行って、その機種の構造的要因に対応させたテーブルが夫々作成されているものとする。   The amount of heat received Hn is determined in advance by a test or the like, and is stored in the storage unit 220 of the outdoor unit control means 200 as a table (not shown) in which the amount of heat received Hn according to the outdoor heat exchange temperature Tc and environmental factors is determined. Ru. In addition, since structural factors differ depending on the size and shape of the model of the outdoor unit 2, each table is tested in advance, and tables corresponding to the structural factors of the model are prepared. Do.

上記の構造的・環境的要因から室外ファン27の一回転当たりに室外ファン27が受ける熱量を推定し、「一回転当たりに受ける熱量」と「ファン除霜運転開始時を起点とした室外ファン27の回転数」との積でファン除霜運転開始時からの受熱量Hnを推定できる。例えば、室外機制御手段200のCPU210が、ファン除霜運転時に熱交温度センサ75で検出する室外熱交温度Tcと外気温度センサ76で検出する外気温度を取り込み、記憶部220に記憶する。また、室外機制御手段200のCPU210は、ファン除霜運転時に室外ファン27の単位時間当たりの回転数を記憶部220に記憶する。テーブルでは、室外熱交温度Tcが高い程「一回転当たりに受ける熱量」を高く設定している。また、外気温度が高い程「一回転当たりに受ける熱量」を高く設定している。また、室外ファン27の単位時間当たりの回転数が高い程「一回転当たりに受ける熱量」を高く設定している。「一回転当たりに受ける熱量」とファン除霜運転開始時を起点とした室外ファン27の回転数との積を算出することにより、室外ファン27が実際に室外熱交換器23から受ける熱量に対応した受熱量Hnを設定できる。なお、本実施形態では、図示しないテーブルを用いて室外熱交温度Tcと前述した構造的・環境的要因から室外ファン27の一回転当たりに室外ファン27が受ける熱量を推定し、「一回転当たりに受ける熱量」と「ファン除霜運転開始時を起点とした室外ファン27の回転数」との積で受熱量Hnを設定しているが、室外熱交温度Tcと構造的・環境的要因及びファン除霜運転開始時を起点とした室外ファン27の回転数(若しくは風量)から受熱量Hnを設定する方法であればこの限りでない。例えば、室外熱交温度Tcと霜の融解温度(0℃)との差を求め、構造的・環境的要因に応じた「補正値」が定められたテーブルを記憶部220し、「差」と「補正値」と「ファン除霜運転開始時を起点とした室外ファン27の回転数」との積で必要熱量Htを推定するようにしても良い。   The amount of heat received by the outdoor fan 27 per one rotation of the outdoor fan 27 is estimated from the structural and environmental factors described above, and "the amount of heat received per one rotation" and "the outdoor fan 27 starting from the start of the fan defrosting operation" The heat reception amount Hn from the start of the fan defrosting operation can be estimated by multiplying the rotational speed of For example, the CPU 210 of the outdoor unit control means 200 takes in the outdoor heat exchange temperature Tc detected by the heat exchange temperature sensor 75 and the outside air temperature detected by the outside air temperature sensor 76 during the fan defrosting operation, and stores them in the storage unit 220. Further, the CPU 210 of the outdoor unit control means 200 stores the number of revolutions per unit time of the outdoor fan 27 in the storage unit 220 during the fan defrosting operation. In the table, “the amount of heat received per one rotation” is set higher as the outdoor heat exchange temperature Tc is higher. Also, as the outside air temperature is higher, "the amount of heat received per one rotation" is set higher. Further, as the number of revolutions per unit time of the outdoor fan 27 is higher, “the amount of heat received per one revolution” is set higher. Corresponds to the amount of heat that the outdoor fan 27 actually receives from the outdoor heat exchanger 23 by calculating the product of “the amount of heat received per rotation” and the number of rotations of the outdoor fan 27 starting from the start of the fan defrosting operation. The received heat amount Hn can be set. In the present embodiment, the amount of heat received by the outdoor fan 27 per rotation of the outdoor fan 27 is estimated from the outdoor heat exchange temperature Tc and the structural and environmental factors described above using a table (not shown). The amount of heat received Hn is set by the product of the amount of heat received by the fan and the number of revolutions of the outdoor fan 27 starting from the start of the fan defrosting operation. However, the outdoor heat exchange temperature Tc, structural and environmental factors, This method is not limited as long as the received heat amount Hn is set based on the number of rotations (or the air volume) of the outdoor fan 27 starting from the start of the fan defrosting operation. For example, the difference between the outdoor heat exchange temperature Tc and the melting temperature of frost (0 ° C.) is determined, and the table in which the “correction value” according to structural and environmental factors is determined is stored in the storage unit 220. The necessary heat amount Ht may be estimated by the product of “correction value” and “the number of rotations of the outdoor fan 27 starting from the start of the fan defrosting operation”.

<ファン回転数調整制御テーブル300について>
図2に示すファン回転数調整制御テーブル300は、予め試験などを行って定められるものであり、温度差ΔTcに応じて、室外ファン回転数加減算値ΔRfo、および、圧縮機回転数加算値ΔRcがそれぞれ定められて、室外機制御手段200の記憶部220に記憶されているものである。
<About the fan rotational speed adjustment control table 300>
The fan rotation number adjustment control table 300 shown in FIG. 2 is determined in advance by a test or the like, and the outdoor fan rotation number addition / subtraction value ΔRfo and the compressor rotation number addition value ΔRc are determined according to the temperature difference ΔTc. They are respectively determined and stored in the storage unit 220 of the outdoor unit control means 200.

ファン回転数調整制御テーブル300における温度差ΔTcは、目標室外熱交温度Tctから室外熱交温度Tcを減じて算出される。目標室外熱交温度Tctは、室外機制御手段200の記憶部220から読み出され、室外熱交温度Tcは熱交温度センサ75で検出したものをCPU210が取り込む。   The temperature difference ΔTc in the fan rotational speed adjustment control table 300 is calculated by subtracting the outdoor heat exchange temperature Tc from the target outdoor heat exchange temperature Tct. The target outdoor heat exchange temperature Tct is read out from the storage unit 220 of the outdoor unit control means 200, and the outdoor heat exchange temperature Tc taken by the heat exchange temperature sensor 75 is taken in by the CPU 210.

ファン除霜運転中、室外熱交温度Tcが目標室外熱交温度Tctから離れていれば、室外熱交温度Tcを目標室外熱交温度Tctに近づけるように室外ファン27及び圧縮機21を制御することで、ファン除霜運転時間を短縮できる。そこで、ファン回転数調整制御テーブル300では、温度差ΔTcを5つの範囲(目標室外熱交温度Tctに比べて室外熱交温度Tcが低い範囲から順に、+10<ΔTc、+5<ΔTc≦+10、−5<ΔTc≦+5、−10<ΔTc≦−5、ΔTc≦−10)に分けている。すなわち、ファン回転数調整制御テーブル300では、室外熱交温度Tcが目標室外熱交温度Tctを大きく下回っているとき(+10<ΔTc)、室外熱交温度Tcを上昇させるために室外ファン回転数加減算値ΔRfo(−20rpm)を加えた室外ファン回転数Rfoは低下し、圧縮機回転数加算値ΔRc(+20rps)を加えた圧縮機回転数Rcは上昇する。すなわち、室外ファン27の回転数を低下させることで、室外熱交換器23を通過する空気の量が低下するため、室外熱交換器23での冷媒と空気との熱交換量が減ることで室外熱交温度Tcが上昇する。更に、圧縮機21の回転数を上昇させることで凝縮圧力が上昇するため、室外熱交温度Tcが上昇する。また、室外熱交温度Tcが目標室外熱交温度Tctを大きく上回っているとき(ΔTc≦−10)、室外熱交温度Tcが多少下がっても室外熱交換器23から室外ファン27へ伝える熱量を増やしたいので、室外ファン回転数加減算値ΔRfo(+20rpm)を加えた室外ファン回転数Rfoは上昇する。   If the outdoor heat exchange temperature Tc is apart from the target outdoor heat exchange temperature Tct during the fan defrosting operation, the outdoor fan 27 and the compressor 21 are controlled so that the outdoor heat exchange temperature Tc approaches the target outdoor heat exchange temperature Tct. Thus, the fan defrosting operation time can be shortened. Therefore, in the fan rotational speed adjustment control table 300, the temperature difference ΔTc is set in the order of the five ranges (the outdoor heat exchange temperature Tc is lower than the target outdoor heat exchange temperature Tct, +10 <ΔTc, +5 <ΔTc ≦ + 10, − 5 <ΔTc ≦ + 5, −10 <ΔTc ≦ −5, ΔTc ≦ −10). That is, in the fan rotational speed adjustment control table 300, when the outdoor heat exchange temperature Tc is much lower than the target outdoor heat exchange temperature Tct (+10 <ΔTc), the outdoor fan rotation speed addition / subtraction is performed to increase the outdoor heat exchange temperature Tc. The outdoor fan rotational speed Rfo to which the value ΔRfo (−20 rpm) is added is decreased, and the compressor rotational speed Rc to which the compressor rotational speed addition value ΔRc (+20 rps) is added is increased. That is, since the amount of air passing through the outdoor heat exchanger 23 is reduced by reducing the rotational speed of the outdoor fan 27, the amount of heat exchange between the refrigerant and the air in the outdoor heat exchanger 23 is reduced. Heat exchange temperature Tc rises. Furthermore, since the condensation pressure is raised by raising the rotational speed of the compressor 21, the outdoor heat exchange temperature Tc is raised. Further, when the outdoor heat exchange temperature Tc greatly exceeds the target outdoor heat exchange temperature Tct (ΔTc ≦ −10), even if the outdoor heat exchange temperature Tc drops a little, the amount of heat transferred from the outdoor heat exchanger 23 to the outdoor fan 27 Since it is desired to increase, the outdoor fan rotational speed Rfo to which the outdoor fan rotational speed addition / subtraction value ΔRfo (+20 rpm) is added is increased.

以上説明したように、ファン回転数調整制御テーブル300では、室外ファン回転数加減算値ΔRfo各値は、温度差ΔTcが正の値で大きくなる程大きい減算値が設定される。また、温度差ΔTcが負の値で小さくなる程大きい加算値が設定される。圧縮機回転数加算値ΔRc各値は、温度差ΔTcが正の値で大きくなる程大きい加算値が設定される。これにより、室外熱交温度Tcが目標室外熱交温度Tctに近づくように室外ファン27及び圧縮機21が制御されるので、ファン除霜運転時間を短縮できる。   As described above, in the fan rotation number adjustment control table 300, the outdoor fan rotation number addition / subtraction value ΔRfo is set to a large subtraction value as the temperature difference ΔTc becomes a positive value. Further, a larger added value is set as the temperature difference ΔTc becomes smaller at a negative value. Each value of the compressor rotation speed addition value ΔRc is set to be a larger addition value as the temperature difference ΔTc becomes a positive value. Thus, the outdoor fan 27 and the compressor 21 are controlled such that the outdoor heat exchange temperature Tc approaches the target outdoor heat exchange temperature Tct, so that the fan defrosting operation time can be shortened.

<除霜運転時の処理の流れ>
次に、図3に示すフローチャートを用いて、除霜運転、つまり、熱交除霜運転およびファン除霜制御テーブル300を用いたファン除霜運転を行う際に、室外機制御手段200のCPU210が実行する処理について説明する。尚、上記各除霜運転を行う際の冷媒回路100における冷媒の流れは前述した冷房運転時と同じであるため、詳細な説明を省略する。
<Flow of processing during defrosting operation>
Next, the CPU 210 of the outdoor unit control means 200 performs the defrosting operation, that is, the heat defrosting operation and the fan defrosting operation using the fan defrosting control table 300, using the flowchart shown in FIG. The processing to be performed will be described. In addition, since the flow of the refrigerant | coolant in the refrigerant circuit 100 at the time of performing said each defrosting operation is the same as the time of the air_conditioning | cooling operation mentioned above, detailed description is abbreviate | omitted.

図3に示すフローチャートは、CPU210が除霜運転を行う際の処理の流れを示すものであり、STはステップを表しこれに続く番号はステップ番号を表している。尚、図3では、本発明に関わる処理を中心に説明しており、これ以外の処理、例えば、使用者の指示した設定温度や風量等の運転条件に対応した冷媒回路100の制御といった、空気調和機1に関わる一般的な処理については説明を省略している。   The flowchart shown in FIG. 3 shows the flow of processing when the CPU 210 performs the defrosting operation, and ST represents a step and the subsequent number represents a step number. In FIG. 3, the process according to the present invention is mainly described, and other processes, for example, the control of the refrigerant circuit 100 corresponding to the operating conditions such as the set temperature and the air volume instructed by the user, etc. Description of the general processing relating to the conditioner 1 is omitted.

CPU210は、暖房運転を行っているときに、除霜運転開始条件が成立しているか否かを判断する(ST101)。ここで、除霜運転開始条件とは、予め試験等を行って定められたものであり、室外熱交換器23での着霜量が暖房能力に支障をきたすレベルであることを示すものである。除霜運転開始条件の具体的な例としては、前述したように、「温度条件」と「時間条件」がある。   When performing the heating operation, the CPU 210 determines whether the defrosting operation start condition is satisfied (ST101). Here, the defrosting operation start condition is determined in advance by a test or the like, and indicates that the amount of frost formation in the outdoor heat exchanger 23 is a level at which the heating capacity is impaired. . As a specific example of the defrosting operation start condition, as described above, there are "temperature condition" and "time condition".

除霜運転開始条件が成立していない場合は(ST101−No)、CPU210は、現在行っている暖房運転を継続する(ST102)。除霜運転開始条件が成立した場合は(ST101−Yes)、CPU210は、熱交除霜運転を実行する(ST103)。熱交除霜運転では、CPU210は、圧縮機21および室外ファン27を停止し、四方弁22を切り替えて、冷媒回路100を冷房運転時の状態とした後、圧縮機21を所定回転数で起動して室外熱交換器23の除霜を行う。熱交除霜運転を行っているときは、室外ファン27および室内ファン32は停止している。これにより、圧縮機21から吐出されて室外熱交換器23に流入した冷媒は、室外熱交換器23に発生した霜を融かす。尚、熱交除霜運転を行うときの圧縮機21の所定回転数は、できる限り高い回転数(例えば、90rps)であることが望ましい。   If the defrosting operation start condition is not satisfied (ST101-No), the CPU 210 continues the heating operation currently performed (ST102). If the defrosting operation start condition is satisfied (ST101-Yes), the CPU 210 executes the heat exchange defrosting operation (ST103). In the heat exchange defrosting operation, the CPU 210 stops the compressor 21 and the outdoor fan 27 and switches the four-way valve 22 to bring the refrigerant circuit 100 into the cooling operation state, and then starts the compressor 21 at a predetermined rotational speed. Then, the outdoor heat exchanger 23 is defrosted. When the heat exchange defrosting operation is performed, the outdoor fan 27 and the indoor fan 32 are stopped. As a result, the refrigerant discharged from the compressor 21 and flowing into the outdoor heat exchanger 23 melts the frost generated in the outdoor heat exchanger 23. In addition, as for the predetermined rotation speed of the compressor 21 when performing heat exchange defrost operation, it is desirable that it is rotation speed as high as possible (for example, 90 rps).

次に、CPU210は、熱交除霜運転終了条件が成立したか否かを判断する(ST104)。ここで、熱交除霜運転終了条件とは、予め試験等を行って定められたものであり、室外熱交換器23で発生した霜が融解したと考えられる条件である。熱交除霜運転終了条件の具体的な例としては、熱交温度センサ75で検出した室外熱交換器23から流出する冷媒温度が10℃以上となったか否か、や、室外熱交除霜運転を開始してから所定時間(例:10分)が経過したか否か等である。   Next, the CPU 210 determines whether the heat exchange defrosting operation end condition is satisfied (ST104). Here, the heat exchange defrosting operation end condition is a condition which is determined in advance by a test or the like, and is a condition considered to be a state where the frost generated in the outdoor heat exchanger 23 is melted. As a specific example of the heat exchange defrosting operation end condition, whether the temperature of the refrigerant flowing out of the outdoor heat exchanger 23 detected by the heat exchange temperature sensor 75 has become 10 ° C. or higher, or outdoor heat exchange defrosting It is whether or not a predetermined time (for example, 10 minutes) has elapsed since the start of operation.

熱交除霜運転終了条件が成立していなければ(ST104−No)、CPU210は、ST103に処理を戻し熱交除霜運転を継続する。熱交除霜運転終了条件が成立していれば(ST104−Yes)、CPU210は、ファン除霜運転開始条件が成立しているか否かを判断する(ST105)。ここで、ファン除霜運転開始条件とは、予め試験等を行って定められたものであり、室外ファン27で発生している霜の量が、室外ファン27の駆動に支障をきたすレベルであることを示すものである。ファン除霜運転開始条件の具体的な例としては、熱交除霜運転終了時に外気温度センサ76で検出した外気温度が−10℃以上かつ5℃以下の場合、等である。ファン除霜運転開始条件が成立していなければ(ST105−No)、つまり、室外ファン27で発生している霜の量が、室外ファン27の駆動に支障のないレベルであれば、CPU210は、ST112に処理を進める。   If the heat exchange defrosting operation end condition is not satisfied (ST104-No), the CPU 210 returns the process to ST103 and continues the heat exchange defrosting operation. If the heat removal defrosting operation end condition is satisfied (ST104-Yes), the CPU 210 determines whether the fan defrosting operation start condition is satisfied (ST105). Here, the fan defrosting operation start condition is determined in advance by a test or the like, and the amount of frost generated by the outdoor fan 27 is a level at which the driving of the outdoor fan 27 is hindered. It shows that. A specific example of the fan defrosting operation start condition is a case where the outside air temperature detected by the outside air temperature sensor 76 at the end of the heat exchange defrosting operation is -10 ° C. or more and 5 ° C. or less. If the fan defrosting operation start condition is not satisfied (ST105-No), that is, if the amount of frost generated by the outdoor fan 27 is a level that does not affect the driving of the outdoor fan 27, the CPU 210 The process proceeds to ST112.

ファン除霜運転開始条件が成立した場合は(ST105−Yes)、つまり、室外ファン27で発生している霜の量が、室外ファン27の駆動に支障のあるレベルであれば、CPU210は、室外ファン27を所定回転数Rfopで駆動して(ST106)、ファン除霜運転を開始する。ここで、所定回転数Rfopは、予め記憶部220に記憶されているものである。所定回転数Rfopに高い回転数を設定すると室内熱交換器23で空気と冷媒の熱交換が促進されて室外熱交温度Tcが下がってしまうため、ファン除霜運転で室外ファン27で発生した霜が溶けることが判明している低回転数にすることが望ましい。尚、所定回転数Rfopは例えば、室外ファン27の使用範囲の下限回転数(例えば、200rpm)である。   If the fan defrosting operation start condition is satisfied (ST105-Yes), that is, if the amount of frost generated by the outdoor fan 27 is at a level that interferes with the driving of the outdoor fan 27, the CPU 210 performs the outdoor operation. The fan 27 is driven at a predetermined rotation speed Rfop (ST106) to start the fan defrosting operation. Here, the predetermined rotation speed Rfop is stored in advance in the storage unit 220. When a high rotational speed is set to the predetermined rotational speed Rfop, heat exchange between the air and the refrigerant is promoted in the indoor heat exchanger 23 and the outdoor heat exchange temperature Tc falls, so the frost generated in the outdoor fan 27 in the fan defrosting operation It is desirable to have a low rotational speed that has been found to melt. The predetermined rotation speed Rfop is, for example, the lower limit rotation speed (for example, 200 rpm) of the use range of the outdoor fan 27.

次に、CPU210は、必要熱量Htを設定する(ST107)。前述したように、CPU210は、室外機制御手段200の記憶部220に記憶され、環境的要因に応じた必要熱量Htが定められた図示しないテーブルを用いて設定される。次に、CPU210は、受熱量Hnを算出する(ST108)。前述したように、CPU210は、室外機制御手段200の記憶部220に記憶され、環境的要因に応じた受熱量Hnが定められた図示しないテーブルを用いて設定される。   Next, the CPU 210 sets the required heat amount Ht (ST107). As described above, the CPU 210 is stored in the storage unit 220 of the outdoor unit control means 200, and is set using a table (not shown) in which the required heat quantity Ht corresponding to the environmental factor is determined. Next, the CPU 210 calculates the received heat amount Hn (ST108). As described above, the CPU 210 is stored in the storage unit 220 of the outdoor unit control means 200, and is set using a table (not shown) in which the received heat amount Hn according to the environmental factor is determined.

次に、CPU210は、ST108で算出した受熱量Hnが必要熱量Ht以上であるか否かを判断する(ST109)。受熱量Hnが必要熱量Ht以上でなければ(ST109−No)、つまり、ファン除霜運転を行ってもまだ室外ファン27で発生した霜が溶けきっていないと推定される場合は、CPU210は、ファン除霜運転を継続して、記憶部220に記憶しているファン回転数調整制御テーブル300を用いて、圧縮機21、室外ファン27を制御する(ST110)。具体的には、CPU210は、室外機制御手段200の記憶部220から目標室外熱交温度Tctを読み出し、熱交温度センサ75で検出した室外熱交温度Tcを取り込み、目標室外熱交温度Tctと室外熱交温度Tcの温度差である温度差ΔTcに応じた圧縮機回転数Rcをファン回転数調整制御テーブル300から抽出し、抽出した圧縮機回転数Rcで圧縮機21を駆動する。また、CPU210は、温度差ΔTcに応じた室外ファン回転数Rfoをファン回転数調整制御テーブル300から抽出し、抽出した室外ファン回転数Rfoで室外ファン27を駆動する。その後、所定時間経過を待ってから(ST111)、ST108に処理を戻して、再度「一回転当たりに受ける熱量」とファン除霜運転開始時を起点とした室外ファン27の回転数との積から受熱量Hnを算出する。所定時間は制御間隔であり、例えば1分である。尚、所定時間経過を待っている間もファン除霜運転開始時を起点とした室外ファン27の回転数は増加しているので、ST111で所定時間が経過した後にST108で再度算出された受熱量Hnは、前回算出された受熱量よりも大きい値になる。   Next, the CPU 210 determines whether the received heat amount Hn calculated in ST108 is the required heat amount Ht or more (ST109). If it is estimated that the heat reception amount Hn is not the required heat amount Ht or more (ST109-No), that is, it is estimated that the frost generated by the outdoor fan 27 is not completely melted even if the fan defrosting operation is performed, the CPU 210 The fan defrosting operation is continued, and the compressor 21 and the outdoor fan 27 are controlled using the fan rotation number adjustment control table 300 stored in the storage unit 220 (ST110). Specifically, the CPU 210 reads out the target outdoor heat exchange temperature Tct from the storage unit 220 of the outdoor unit control means 200, takes in the outdoor heat exchange temperature Tc detected by the heat exchange temperature sensor 75, and outputs the target outdoor heat exchange temperature Tct. The compressor rotation number Rc is extracted from the fan rotation number adjustment control table 300 according to the temperature difference ΔTc which is the temperature difference of the outdoor heat exchange temperature Tc, and the compressor 21 is driven at the extracted compressor rotation number Rc. Further, the CPU 210 extracts the outdoor fan rotational speed Rfo corresponding to the temperature difference ΔTc from the fan rotational speed adjustment control table 300, and drives the outdoor fan 27 with the extracted outdoor fan rotational speed Rfo. Then, after waiting for a predetermined time (ST111), the process returns to ST108, and again from the product of "the amount of heat received per one rotation" and the rotational speed of the outdoor fan 27 starting from the start of the fan defrosting operation. The amount of heat received Hn is calculated. The predetermined time is a control interval, for example, one minute. In addition, since the rotation speed of the outdoor fan 27 starting from the fan defrosting operation start time is increasing while waiting for the predetermined time to elapse, the heat receiving amount recalculated in ST108 after the predetermined time has elapsed in ST111. Hn is a value larger than the heat receiving amount calculated previously.

受熱量Hnが必要熱量Ht以上であれば(ST109−Yes)、つまり、ファン除霜運転を行ったことで、室外ファン27で発生した霜が溶けて室外ファン27の駆動に支障がなくなったと推定される場合は、CPU210は、暖房運転を再開する(ST112)。ここで、運転再開にあたって、CPU210は、圧縮機21および室外ファン27を停止し、四方弁22を切り替えて、冷媒回路100を暖房運転時の状態にする。   If the received heat amount Hn is equal to or more than the required heat amount Ht (ST109-Yes), that is, it is estimated that the frost generated in the outdoor fan 27 is melted and the driving of the outdoor fan 27 is not disturbed by performing the fan defrosting operation. If it is, the CPU 210 resumes the heating operation (ST112). Here, in resuming the operation, the CPU 210 stops the compressor 21 and the outdoor fan 27 and switches the four-way valve 22 to put the refrigerant circuit 100 in a heating operation state.

以上説明したように、本実施形態の空気調和機1では、ファン除霜運転の運転時間を室外ファン27の受熱量Hnが必要熱量Ht以上になるまでとしたので、ファン除霜運転の運転時間に室外ファン27で発生した霜を完全に融かすために必要最低限の時間を設定することができるので、ファン除霜運転時間を最適な長さにすることができる。   As described above, in the air conditioner 1 of the present embodiment, since the operation time of the fan defrosting operation is until the amount of heat received Hn of the outdoor fan 27 becomes the required heat amount Ht or more, the operation time of the fan defrosting operation Since it is possible to set the minimum necessary time to completely melt the frost generated by the outdoor fan 27, it is possible to make the fan defrosting operation time an optimal length.

1 空気調和機
2 室外機
3 室内機
21 圧縮機
23 室外熱交換器
24 膨張弁
27 室外ファン
27a ファンモータ
31 室内熱交換器
32 室内ファン
100 冷媒回路
200 室外機制御手段
210 CPU
220 記憶部
300 ファン回転数調整制御テーブル
Hn 受熱量
Ht 必要熱量
Rc 圧縮機回転数
ΔRc 圧縮機回転数加算値
Rfo 室外ファン回転数
ΔRfo 室外ファン回転数加減算値
Tc 室外熱交温度
Tct 目標室外熱交温度
ΔTc 目標室外熱交温度
1 air conditioner 2 outdoor unit 3 indoor unit 21 compressor 23 outdoor heat exchanger 24 expansion valve 27 outdoor fan 27a fan motor 31 indoor heat exchanger 32 indoor fan 100 refrigerant circuit 200 outdoor unit control means 210 CPU
220 storage unit 300 fan rotational speed adjustment control table Hn heat receiving amount Ht necessary heat amount Rc compressor rotational speed ΔRc compressor rotational speed additional value Rfo outdoor fan rotational speed ΔRfo outdoor fan rotational speed addition / subtraction value Tc outdoor heat exchange temperature Tct target outdoor heat exchange Temperature ΔTc Target outdoor heat exchange temperature

Claims (2)

暖房運転時に、圧縮機、室内熱交換器、膨張弁、室外熱交換器の順で冷媒が循環する冷媒回路と、
前記冷媒回路に備えられ、前記圧縮機から吐出された冷媒の流れる方向を切り替える流路切替手段と、
前記室外熱交換器に送風する室外ファンと、
外気温度を検出する外気温度検出手段を有し、
前記暖房運転時に、前記室外ファンを停止させるとともに、前記流路切替手段を切り替えて前記圧縮機から吐出された冷媒を前記室外熱交換器に向かわせる熱交除霜運転と、前記熱交除霜運転が終了した後に、前記圧縮機から吐出された冷媒を前記室外熱交換器に向かわせたまま、前記室外ファンを駆動して同室外ファンを除霜するファン除霜運転を行う制御手段と、
を有する空気調和機であって、
前記制御手段は、
前記ファン除霜運転中、前記室外熱交換器から前記室外ファンに与えられた熱量の推定値である受熱量が、前記室外ファンで発生した霜を融かすために必要な熱量の推定値である必要熱量以上となったら前記ファン除霜運転を終了する、
ことを特徴とする空気調和機。
A refrigerant circuit in which a refrigerant circulates in the order of a compressor, an indoor heat exchanger, an expansion valve, and an outdoor heat exchanger during heating operation;
Flow path switching means provided in the refrigerant circuit to switch the flow direction of the refrigerant discharged from the compressor;
An outdoor fan for blowing air to the outdoor heat exchanger;
It has an outside air temperature detection means for detecting the outside air temperature,
Heat exchange defrosting operation for stopping the outdoor fan at the time of the heating operation and switching the flow path switching means to direct refrigerant discharged from the compressor to the outdoor heat exchanger, and the heat exchange defrosting A control means for performing a fan defrosting operation for driving the outdoor fan and defrosting the outdoor fan while the refrigerant discharged from the compressor is directed to the outdoor heat exchanger after the operation is completed;
An air conditioner having
The control means
During the fan defrosting operation, the amount of heat received, which is an estimated value of the amount of heat given from the outdoor heat exchanger to the outdoor fan, is an estimated value of the amount of heat necessary to melt the frost generated by the outdoor fan. The fan defrosting operation is ended when the required heat quantity is exceeded,
An air conditioner characterized by
前記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を有し、
前記制御手段は、
ファン除霜運転中、前記室外熱交温度が目標室外熱交温度に近づくように、前記圧縮機及び前記室外ファンのうち少なくとも一つを制御する
ことを特徴とする請求項1に記載の空気調和機。
It has outdoor heat exchange temperature detection means which detects the outdoor heat exchange temperature which is the temperature of the said outdoor heat exchanger,
The control means
The air conditioning according to claim 1, wherein at least one of the compressor and the outdoor fan is controlled such that the outdoor heat exchange temperature approaches a target outdoor heat exchange temperature during a fan defrosting operation. Machine.
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Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN110454917A (en) * 2019-08-23 2019-11-15 四川长虹空调有限公司 Low ambient temperature air-source heat-pump air heater defrosting tonifying Qi electromagnetic valve control method
CN110848886A (en) * 2019-11-28 2020-02-28 广东美的制冷设备有限公司 Air conditioner, defrosting method thereof and computer readable storage medium
CN111023453A (en) * 2019-12-25 2020-04-17 宁波奥克斯电气股份有限公司 Air conditioner defrosting control method and device, air conditioner and storage medium
CN113465126A (en) * 2021-06-21 2021-10-01 青岛海尔空调电子有限公司 Defrosting control method and system for air conditioner outdoor unit and storage medium
CN114659234A (en) * 2022-02-28 2022-06-24 青岛海尔空调电子有限公司 Method and device for defrosting of air conditioner and air conditioner
WO2022242141A1 (en) * 2021-05-20 2022-11-24 青岛海尔空调器有限总公司 Control method and apparatus for implementing self-cleaning function of air conditioner, and air conditioner

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN110454917A (en) * 2019-08-23 2019-11-15 四川长虹空调有限公司 Low ambient temperature air-source heat-pump air heater defrosting tonifying Qi electromagnetic valve control method
CN110848886A (en) * 2019-11-28 2020-02-28 广东美的制冷设备有限公司 Air conditioner, defrosting method thereof and computer readable storage medium
CN111023453A (en) * 2019-12-25 2020-04-17 宁波奥克斯电气股份有限公司 Air conditioner defrosting control method and device, air conditioner and storage medium
WO2022242141A1 (en) * 2021-05-20 2022-11-24 青岛海尔空调器有限总公司 Control method and apparatus for implementing self-cleaning function of air conditioner, and air conditioner
CN113465126A (en) * 2021-06-21 2021-10-01 青岛海尔空调电子有限公司 Defrosting control method and system for air conditioner outdoor unit and storage medium
CN114659234A (en) * 2022-02-28 2022-06-24 青岛海尔空调电子有限公司 Method and device for defrosting of air conditioner and air conditioner
CN114659234B (en) * 2022-02-28 2024-02-23 青岛海尔空调电子有限公司 Method and device for defrosting air conditioner and air conditioner

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