JPS61256160A - Heat pump type air conditioner - Google Patents

Abstract

(57)【要約】本公報は電子出願前の出願データであるた
め要約のデータは記録されません。(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

【発明の詳細な説明】 産業上の利用分野 本発明は、空気を熱源とするヒートポンプ式空調機に関
するもので、詳しくは低外気時に室外熱交換器に付着す
る霜を融解する除霜制御に関するものである。DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a heat pump type air conditioner that uses air as a heat source, and more specifically to defrosting control that melts frost adhering to an outdoor heat exchanger when the outside air temperature is low. It is.

従来の技術 従来空気熱源ヒートポンプ式空調機の室外熱交換器の除
霜方式は、大半が四方弁を切換えて冷房サイタルさし、
室外熱交換器を凝縮器、室内熱交換器を蒸発器とする逆
サイクル除霜方式で、この時コールドドラフト防止の為
に室内ファンを停止していた。Conventional technology Most defrosting methods for outdoor heat exchangers in conventional air-source heat pump air conditioners operate by switching a four-way valve to direct the cooling site.
It uses a reverse cycle defrosting system in which the outdoor heat exchanger is used as a condenser and the indoor heat exchanger is used as an evaporator, and the indoor fan was stopped at this time to prevent cold drafts.

この方式では基本的に冷媒循環が少なく圧縮機入力の増
大がそれほど期待できないので、除霜時間が長くなるこ
と、並びに除霜運転中の数分間は室内ファンが停止する
ので暖房感が欠如し快適性が損なわれること、さらには
除霜運転終了後の四方弁が切換わって暖房運転に復帰し
てからも室内熱交換器の温度が上昇するまでに時間を要
するなど使用者からすれば満足できるものではなかった
。With this method, there is basically little refrigerant circulation and it is not possible to expect much increase in compressor input, so the defrosting time becomes longer, and the indoor fan stops for several minutes during defrosting operation, so there is no feeling of heating and comfort. This is not satisfactory from the user's point of view, as it takes time for the temperature of the indoor heat exchanger to rise even after the four-way valve switches after defrosting operation and returns to heating operation. It wasn't something.

近年このような欠点を有する逆サイクル除霜方式に代わ
って、除霜運転時にも四方弁は暖房運転時のままとし、
圧縮機からの吐出ガスの一部を室内熱交換器に流して若
干の暖房能力を維持しながら、吐出ガスの残りを室外熱
交換器の入口に導き除霜を行なうホットガスバイパス除
霜方式が提案されている（例えば「日本冷凍協会講演論
文集」。In recent years, in place of the reverse cycle defrosting system which has these drawbacks, the four-way valve is kept as it is in heating operation even during defrosting operation.
A hot gas bypass defrosting system allows part of the discharged gas from the compressor to flow through the indoor heat exchanger to maintain some heating capacity, while the rest of the discharged gas is guided to the inlet of the outdoor heat exchanger for defrosting. (e.g. ``Japan Refrigeration Association Lecture Proceedings'').

５５９−１１．Ｐ、５３）。559-11. P, 53).

以下図面を参照しながら上述の従来のヒートポンプ式空
調機の一例について説明する。An example of the above-mentioned conventional heat pump type air conditioner will be described below with reference to the drawings.

第４図は従来のヒートポンプ式空調機の冷凍サイクル図
を示すものである。FIG. 4 shows a refrigeration cycle diagram of a conventional heat pump type air conditioner.

同図において１は容量制御可能な周波数可変圧縮機、２
は四方弁、３は室内熱交換器、４は弁開度を可変できる
電動膨張弁、５ＴＩ′ｉ室外熱交換器、６はホットガス
バイパス回路、７は二方弁である。In the figure, 1 is a variable frequency compressor with capacity control;
3 is a four-way valve, 3 is an indoor heat exchanger, 4 is an electric expansion valve whose valve opening degree can be varied, 5TI'i is an outdoor heat exchanger, 6 is a hot gas bypass circuit, and 7 is a two-way valve.

ホットガスバイパス回路６は、周波数可変圧縮機１の吐
出側と室外熱交換器５の暖房運転時に入口側となる配管
とを連結し、途中に二方弁７を備えて構成されている。The hot gas bypass circuit 6 connects the discharge side of the variable frequency compressor 1 to a pipe that becomes the inlet side during heating operation of the outdoor heat exchanger 5, and includes a two-way valve 7 in the middle.

通常の暖房運転時には二方弁７は閉の状態で暖房サイク
ルを形成するが、低外気時に室外熱交換器５に着霜が生
じ、暖房能力が低下して除霜運転が必要になると、二方
弁７を開いて高温の吐出ガスの大部分をホットガスバイ
パス回路６を経て室外熱交換器５の入口側へ導く。同時
に高温の吐出ガスの残りを暖房運転時と同様に四方弁２
、室内熱交換器３、電動膨張弁４と流し、若干の暖房運
転を継続して行ない、室外熱交換器５の入口側である点
Ｃにて高圧側で分岐した大部分の冷媒と合流させる。こ
の合流後の冷媒は自身の持つ凝縮熱で室外熱交換器５を
除霜した後、四方弁２を経て周波数可変圧縮機１に戻り
除霜サイ・クルを完結する。During normal heating operation, the two-way valve 7 is closed to form a heating cycle, but when frost forms on the outdoor heat exchanger 5 when the outside air temperature is low, the heating capacity decreases and a defrosting operation becomes necessary. The diverter valve 7 is opened to guide most of the high temperature discharged gas to the inlet side of the outdoor heat exchanger 5 via the hot gas bypass circuit 6. At the same time, the remainder of the high-temperature discharged gas is removed from the four-way valve 2 in the same way as during heating operation.
, the indoor heat exchanger 3 and the electric expansion valve 4, continue to perform a slight heating operation, and merge with most of the refrigerant branched on the high pressure side at point C, which is the inlet side of the outdoor heat exchanger 5. . After this combined refrigerant defrosts the outdoor heat exchanger 5 with its own condensation heat, it returns to the variable frequency compressor 1 via the four-way valve 2 and completes the defrost cycle.

発明が解決しようとする問題点 しかしながら上記構成では以下のような問題点があった
。第５図は第４図に示すヒートポンプ式空調機の従来例
の除霜運転時におけるモリエル線図を示したものである
。同図に示す記号ａ　”−’　ｅは第４図に示したもの
と対応する。Problems to be Solved by the Invention However, the above configuration has the following problems. FIG. 5 shows a Mollier diagram of the conventional heat pump type air conditioner shown in FIG. 4 during defrosting operation. The symbols a''-'e shown in the figure correspond to those shown in FIG.

すなわち除霜運転時に圧縮機吐出側の点ａで分岐した冷
媒は室外熱交換器５０入口側の点Ｃで合流し、この点Ｃ
は温度の高い過熱域に存在する。That is, during defrosting operation, the refrigerant branched at point a on the compressor discharge side joins at point C on the inlet side of the outdoor heat exchanger 50, and this point C
exists in the superheated region.

ここで冷媒は１０なるエンタルピを持つ。そして凝縮後
、つまり除霜後の冷媒状態は二相域の液分の多い点ｄま
で変化して圧力損失後の点ｅとなり、この液分の多い乾
き度ｘ１１なる冷媒をそのまま周波数可変圧縮機１に吸
入されるので相当の液圧縮を行なっていることになる。Here, the refrigerant has an enthalpy of 10. After condensation, that is, after defrosting, the refrigerant state changes to point d with a high liquid content in the two-phase region and reaches point e after pressure loss. 1, so a considerable amount of liquid compression is being performed.

これは年間のヒートポンプシーズンの除霜回数を考慮す
ると圧縮機信頼性上大きな問題となる。さらに除霜時の
冷媒の利用状況（点Ｃ→点ｄ）からすると、冷媒の顕熱
（過熱域）と潜熱（二相域）を利用しており、霜が融解
しドレン水が滴下し始める除霜後期には室外熱交換器５
の表面に温度分布を生じるので、室外熱交換器５の表面
の高温部からは周囲の大気に対流放熱し除霜性能を落と
していることにもなる。This poses a major problem in terms of compressor reliability, considering the number of defrosting operations during the annual heat pump season. Furthermore, looking at the usage status of the refrigerant during defrosting (point C → point d), the sensible heat (superheat region) and latent heat (two-phase region) of the refrigerant are used, and as the frost melts, drain water begins to drip. In the later stages of defrosting, the outdoor heat exchanger 5
Since a temperature distribution occurs on the surface of the outdoor heat exchanger 5, convective heat is radiated from the high temperature portion of the surface of the outdoor heat exchanger 5 to the surrounding atmosphere, which also reduces the defrosting performance.

また第６図は前記従来のと一トポンプ式空調機の除霜運
転時の暖房能力の変化を示し、第７図は同じく除霜運転
時の高圧側圧力と低圧側圧力の変化を示す。第７図にお
いてＡは高圧側圧力、Ｂは低圧側圧力を示す。同図より
明らかなように除霜が進むにつれて高圧側圧力Ａと低圧
側圧力Ｂの比、すなわち圧縮比が小さくなり、また低圧
側圧力Ｂは上昇するので前記周波数可変圧縮機１の吸入
側の冷媒の比容積が小さくなって冷凍サイクル内の冷媒
の、循環量は増加し、したがって暖房能力は除霜開始時
一旦大きく低下した後後々に増加する。Further, FIG. 6 shows the change in the heating capacity of the conventional single-pump air conditioner during defrosting operation, and FIG. 7 similarly shows the change in high pressure side pressure and low pressure side pressure during defrosting operation. In FIG. 7, A indicates the high pressure side pressure, and B indicates the low pressure side pressure. As is clear from the figure, as defrosting progresses, the ratio of the high pressure side pressure A and the low pressure side pressure B, that is, the compression ratio, decreases, and the low pressure side pressure B increases, so that the suction side of the frequency variable compressor 1 decreases. As the specific volume of the refrigerant becomes smaller, the amount of refrigerant circulated within the refrigeration cycle increases, and therefore the heating capacity decreases significantly at the start of defrosting and then increases later.

このため除霜開始時、暖房能力が大きく低下して室内へ
吹き出す空気の温度も低下し、居住者に不快感を与える
恐れがあり、また除霜終了時近くになると暖房能力は除
霜開始時に比べて大きくなりすぎ、それだけ除霜時間も
長くなっていた。As a result, when defrosting begins, the heating capacity decreases significantly and the temperature of the air blown into the room also drops, potentially causing discomfort to the occupants. It was getting too big, and the defrosting time was getting longer.

本発明は上記問題点に鑑み、除霜運転時にも室内熱交換
器に高温の吐出ガスの一部を流して暖房運転継続可能と
して、圧縮機への多量の液戻りや液圧縮を軽減し、室外
熱交換器表面の温度分布を改善して一様温度とする均一
除霜を実現し１除霜運転開始時に室内ファンの風量分暖
房運転時より低下させ、除霜運転時に室内ファンの風量
を変化させて、長期にわたって信頼性の高い、しかも居
住者に不快感を与えることなく除霜効率を改善したヒー
トポンプ式空調機を提供するものである。In view of the above-mentioned problems, the present invention allows a portion of the high temperature discharged gas to flow through the indoor heat exchanger during defrosting operation to allow continued heating operation, thereby reducing a large amount of liquid returning to the compressor and liquid compression. Achieves uniform defrosting by improving the temperature distribution on the surface of the outdoor heat exchanger to achieve a uniform temperature. 1. At the start of defrosting operation, the air volume of the indoor fan is lowered than during heating operation, and during defrosting operation, the air volume of the indoor fan is reduced. To provide a heat pump air conditioner that is highly reliable over a long period of time and has improved defrosting efficiency without causing discomfort to residents.

問題点を解決するための手段 上記問題点を解決するために本発明のヒートポンプ式空
調機は、圧縮機、四方弁、室内熱交換器、絞り量を可変
とした絞り装置、室外熱交換器等を順次環状に配管で連
結して冷凍サイクルを構成し、暖房運転時に高圧となる
前記圧縮機より前記室内熱交換器に至る配管と、同じく
暖房運転時に低圧となる前記室外熱交換器より圧縮機に
至る配管とを結ぶバイパス回路を形成し、前記バイパス
回路に開閉弁を設けて、前記室外熱交換器の除霜運転開
始時には前記絞り装置の絞り量を暖房運転時の絞り量よ
りも小さく（７、さらに前記開閉弁を開とし、室内ファ
ンの除霜運転開始時には前記絞り低下させ、除霜運転時
に前記室内ファンの風量を変化させるものである。Means for Solving the Problems In order to solve the above problems, the heat pump air conditioner of the present invention includes a compressor, a four-way valve, an indoor heat exchanger, a throttling device with variable throttling amount, an outdoor heat exchanger, etc. A refrigeration cycle is constructed by sequentially connecting the pipes in an annular manner through piping, with piping leading from the compressor to the indoor heat exchanger, which is at high pressure during heating operation, and piping from the outdoor heat exchanger, which is at low pressure during heating operation, to the compressor. A bypass circuit is formed that connects the piping leading to the pipe, and an on-off valve is provided in the bypass circuit, and when the defrosting operation of the outdoor heat exchanger starts, the throttling amount of the throttling device is made smaller than the throttling amount during the heating operation. 7. Further, the opening/closing valve is opened, the aperture is lowered when the indoor fan starts defrosting operation, and the air volume of the indoor fan is changed during the defrosting operation.

作　　用 本発明は北上構成により、除霜運転時にも高温の吐出ガ
スの一部を室内熱交換器に流して暖房運転継続可能とし
、第１の絞り装置の絞りを小さくして、高温の吐出ガス
の残りを室外熱交換器出口である圧縮機吸入側へ直接戻
すので、冷媒循環もよく圧縮機入力を維持した状態で、
圧縮機吸入冷媒も二相ではあるか乾き度を大きくでき、
液戻りや液圧縮を軽減できる。また室外熱交換器への流
入冷媒も二相となり、除霜初期、中期はもちろん融解後
のドレン水滴下中の後期から乾燥期寸で室外熱交換器表
面は温度ムラなく一様に温度上昇するので、暖房運転に
戻る復帰温度までに一部分がどんどん温度上昇するこ吉
がなくなり、それだけ周囲への対流放熱損失が押さえら
れて除霜効率も改善できる。さらに、除霜開始時に室内
ファンの風量を低下させ、除霜運転時にこの室内ファン
の風量を変化させることで除霜時居住者に不快感を与え
ることなくまだ不必要な暖房を行なわず、除霜効率をさ
らに改善できる。Effects The present invention has a kitakami configuration that allows part of the high temperature discharged gas to flow to the indoor heat exchanger even during defrosting operation to continue the heating operation, and reduces the aperture of the first throttle device to reduce the high temperature discharged gas. The remainder of the gas is returned directly to the compressor suction side, which is the outlet of the outdoor heat exchanger, so refrigerant circulation is good and the compressor input is maintained.
The compressor suction refrigerant is also two-phase, but the dryness can be increased,
Reduces liquid return and liquid compression. In addition, the refrigerant flowing into the outdoor heat exchanger becomes two-phase, and the temperature on the surface of the outdoor heat exchanger rises uniformly and evenly during the early and middle stages of defrosting, as well as from the latter stages during the dripping of drain water after melting to the drying stage. Therefore, there is no chance that the temperature in one part will rise rapidly until the temperature returns to heating operation, and the loss of convective heat radiation to the surroundings can be suppressed to the extent that the defrosting efficiency can be improved. Furthermore, by reducing the air volume of the indoor fan at the start of defrosting and changing the air volume of this indoor fan during defrosting operation, it is possible to eliminate unnecessary heating without causing discomfort to residents during defrosting. Frost efficiency can be further improved.

実施例 以下本発明の一実施例のヒートポンプ式空調機について
、図面を参照しながら説明する。EXAMPLE Hereinafter, a heat pump type air conditioner according to an example of the present invention will be described with reference to the drawings.

第１図は本発明の一実施例におけるヒートポンプ式空調
機の冷凍サイクル図を示すものである。FIG. 1 shows a refrigeration cycle diagram of a heat pump air conditioner according to an embodiment of the present invention.

同図において、１１は圧縮機、１２は四方弁、１３は室
内熱交換器、１４は電磁力で弁開度を可変できる電動膨
張弁、１５け室外熱交換器、１６はバイパス回路、１７
はバイパス回路に設けられた開閉弁、１８は室内熱交換
器１３と熱交換した空気を室内に吹き出す室内ファン、
１９はこの室内ファンを駆動するトランジスタモータ等
の速度可変の駆動モーフである。また２０は室内熱交換
器１３の温度を検知する室内温度検出素子、２１は室外
熱交換器１５の温度を検知する室外温度検出素子であり
、２２はこの室内温度検出素子２０、室外温度検出素子
２１の温度信号を受けて電動膨張弁１４、開閉弁１７、
駆動モータ１９を制御する制御回路である。そして、圧
縮機１１、四方弁１２、室内熱交換器１３、電動膨張弁
１４、室外熱交換器１５を順次環状に連結し、さらて圧
縮機１１の吐出側と、室外熱交換器１５の暖房運転時の
出口側とを結び、その途中に開閉弁１７を備えたバイパ
ス回路１６を設けたものである。In the figure, 11 is a compressor, 12 is a four-way valve, 13 is an indoor heat exchanger, 14 is an electric expansion valve whose valve opening can be varied by electromagnetic force, 15 is an outdoor heat exchanger, 16 is a bypass circuit, and 17
18 is an on-off valve provided in the bypass circuit; 18 is an indoor fan that blows air that has exchanged heat with the indoor heat exchanger 13 into the room;
Reference numeral 19 is a variable speed drive morph such as a transistor motor that drives this indoor fan. Further, 20 is an indoor temperature detection element that detects the temperature of the indoor heat exchanger 13, 21 is an outdoor temperature detection element that detects the temperature of the outdoor heat exchanger 15, and 22 is the indoor temperature detection element 20 and the outdoor temperature detection element. In response to the temperature signal of 21, the electric expansion valve 14, the on-off valve 17,
This is a control circuit that controls the drive motor 19. The compressor 11, the four-way valve 12, the indoor heat exchanger 13, the electric expansion valve 14, and the outdoor heat exchanger 15 are sequentially connected in an annular manner, and the discharge side of the compressor 11 and the outdoor heat exchanger 15 are heated. A bypass circuit 16 connected to the outlet side during operation and equipped with an on-off valve 17 is provided in the middle.

次に、以上のように構成されたヒートポンプ式空調機に
ついてその動作を説明する。Next, the operation of the heat pump air conditioner configured as described above will be explained.

通常の暖房運転時には開閉弁１７は閉の状咀となってお
り、冷媒は圧縮機１１、四方弁１２、室内熱交換器１３
、電動膨張弁１４、室外熱交換器１５、四方弁１２と流
れて圧縮機１１に戻り暖房サイクルを形成し、バイパス
回路１６には冷媒は流れない。During normal heating operation, the on-off valve 17 is in a closed state, and the refrigerant flows through the compressor 11, four-way valve 12, and indoor heat exchanger 13.
, the electric expansion valve 14, the outdoor heat exchanger 15, and the four-way valve 12, and returns to the compressor 11 to form a heating cycle, and no refrigerant flows into the bypass circuit 16.

ところが低外気温時には、室外熱交換器１５に着霜が生
じ、室外温度検出素子２１の温度信号が設定値まで下が
ると制御回路２２が除霜開始指令を発し、四方弁１２け
そのままの状態で開閉弁１７を開とし、高温の吐出ガス
を点ａ′で分岐させ、一部はそのまま室内熱交換器１３
へ流し、残りは室外熱交換器１５の出口側へ導くととも
に、電動膨張弁１４の弁開度を全開気味にすることで絞
り量をほぼゼロとし、駆動モータ１９の回転数すなわち
室内ファン１８の回転数を暖房運転時より低下させて室
内へ吹き出す風量を低下させて除霜を開始する。However, when the outside temperature is low, frost forms on the outdoor heat exchanger 15, and when the temperature signal of the outdoor temperature detection element 21 drops to the set value, the control circuit 22 issues a command to start defrosting, and the four-way valve 12 remains in the same state. The on-off valve 17 is opened and the high-temperature discharged gas is branched at point a', and a portion is directly sent to the indoor heat exchanger 13.
The remainder is guided to the outlet side of the outdoor heat exchanger 15, and the amount of throttling is made almost zero by setting the valve opening of the electric expansion valve 14 to a slightly full open position, thereby reducing the rotation speed of the drive motor 19, that is, the indoor fan 18. Defrosting is started by lowering the rotation speed compared to during heating operation to reduce the amount of air blown into the room.

第２図は、第１図に示すヒートポンプ式空調機の一実施
例の除霜運転時におけるサイクルをモリエル線図に示し
たものである。FIG. 2 is a Mollier diagram showing a cycle during defrosting operation of one embodiment of the heat pump type air conditioner shown in FIG.

同図に示す記号ａ′〜ｅ′は第１図に示したものと対応
する。すなわち除霜運転時に点ａ′からそのまま室内熱
交換器１３へ流した高温の吐出ガスは、電動膨張弁１４
の弁開度が全開気味になっているので比較的低い温度（
約３０〜４０℃）で凝縮放熱し点ｂ′に移り室内ファン
を低速回転させて暖房運転継続可能となる。途中の配管
や電動膨張弁１４の若干の絞りで減圧して点Ｃ′となり
室外熱交換器１５に流入して、さらに霜の融解温度であ
る約０℃で凝縮放熱して除霜し点ｄ′に至る。この時の
除霜に利用する冷媒のエンタルピ差はΔ’ｄｅｆ”１ｃ
”ｄ’となり、室外熱交換器１５への流入冷媒状態は点
Ｃ′に示すように既に二相となっている。ちなみに室内
暖房に利用する冷媒のエンタルピ差は途中の熱ロスを無
視すればｉ　ａｌ−ｉ　ｂｌとなる。Symbols a' to e' shown in the figure correspond to those shown in FIG. That is, during the defrosting operation, the high temperature discharge gas that flows directly from point a' to the indoor heat exchanger 13 is transferred to the electric expansion valve 14.
Since the valve opening degree is almost fully open, the temperature is relatively low (
The heat is condensed and radiated at a temperature of about 30 to 40° C.), and the indoor fan is rotated at a low speed to continue the heating operation. The pressure is reduced by the pipes along the way and a slight restriction of the electric expansion valve 14, and the temperature reaches point C', which flows into the outdoor heat exchanger 15, where it is further condensed and radiated heat at about 0°C, which is the melting temperature of frost, to defrost it to point d. ′. The enthalpy difference of the refrigerant used for defrosting at this time is Δ'def"1c
d', and the state of the refrigerant flowing into the outdoor heat exchanger 15 is already two-phase as shown at point C'.By the way, the enthalpy difference of the refrigerant used for indoor heating is, if heat loss on the way is ignored. i al-i bl.

一方残りの高温の吐出ガスは室外熱交換器１５の出口側
に導かれるのではソ等エンクルピ変化後、主回路を流れ
てきた液分の多い冷媒と合流し混合して点ｅ′となり、
圧縮機１１に吸入される。この点ｅ′は二相状態にある
ものの冷媒乾き度ｘｅ’が大きく液分が少ないので液戻
りや液圧縮を軒減または実質的に回避することができる
。さらにまた除霜運転時に室外熱交換器１５へ流入して
いる冷媒は基本的に二相状態であるため冷媒温度つまり
室外熱交換器１５の表面温度も一定となり、同表面温度
にむらがないため均一除霜が実現できる。On the other hand, the remaining high-temperature discharged gas is guided to the outlet side of the outdoor heat exchanger 15, and after undergoing an energy change, it joins and mixes with the liquid-rich refrigerant that has flowed through the main circuit and reaches point e'.
It is sucked into the compressor 11. At this point e', although the refrigerant is in a two-phase state, the refrigerant dryness xe' is large and the liquid content is small, so that liquid return and liquid compression can be reduced or substantially avoided. Furthermore, since the refrigerant flowing into the outdoor heat exchanger 15 during defrosting operation is basically in a two-phase state, the refrigerant temperature, that is, the surface temperature of the outdoor heat exchanger 15, is also constant, and there is no unevenness in the surface temperature. Uniform defrosting can be achieved.

また除霜運転開始時、開閉弁１７を開くことで高圧側圧
力が大きく低下して暖房能力が急激に低下するが、室内
ファン１８の回転数を暖房運転時より低下させるので、
室内側熱交換器１３と熱交換して室内に吹き出す空気の
温度の低下を少なくすることができ、居住者に不快感を
与えない。さらに、除霜が進行するにしたがって従来例
で示したのと同様に、次第に高圧側圧力が高くなって暖
房能力が大きくなるが、室内温度検出素子２１の温度信
号が設定値まで上昇すると制御回路２２により駆動モー
タ１９の回転数すなわち室内ファン１８の回転数を低下
させ、暖房能力の増加を押さえることで室外熱交換器１
５の除霜能力を増加させ、したがってさらに除霜効率の
改善が可能となる。Furthermore, when the defrosting operation starts, opening the on-off valve 17 greatly reduces the high-pressure side pressure and rapidly reduces the heating capacity, but since the rotation speed of the indoor fan 18 is lower than during heating operation,
It is possible to reduce the decrease in the temperature of the air blown into the room by exchanging heat with the indoor heat exchanger 13, so that the occupant does not feel uncomfortable. Furthermore, as defrosting progresses, the high-pressure side pressure gradually increases and the heating capacity increases, as shown in the conventional example, but when the temperature signal from the indoor temperature detection element 21 rises to the set value, the control circuit 22 reduces the rotation speed of the drive motor 19, that is, the rotation speed of the indoor fan 18, and suppresses an increase in heating capacity, thereby increasing the outdoor heat exchanger 1.
5, thereby making it possible to further improve the defrosting efficiency.

第３図の実線は、本発明の一実施例におけるヒートポン
プ式空調機の除霜運転時の暖房能力の変化を示すもので
、前記のように室内ファン１８の回転数を変化させるこ
とで破線で示す従来例のヒートポンプ式空調機の除霜時
の暖房能力の変化と比較して除霜終了時近くで不必要な
暖房を行なうことがない。The solid line in FIG. 3 shows the change in heating capacity during defrosting operation of the heat pump type air conditioner in one embodiment of the present invention. Compared to the change in heating capacity during defrosting of the conventional heat pump air conditioner shown in FIG. 1, unnecessary heating is not performed near the end of defrosting.

なお１．本発明は絞り装置の最良の形態として電磁力を
駆動源として弁開度を可変とした電動膨張弁１４を用い
て説明したが、キャピラリ等の絞りを複数個用いて構成
し、適宜切換により制御してもよく、さらに弁開度を可
変する手段としてバイメタル若しくは形状記憶合金等を
用いてもよい。Note 1. The present invention has been described using an electric expansion valve 14 that uses electromagnetic force as a drive source to vary the valve opening as the best form of the throttle device. Furthermore, a bimetal, a shape memory alloy, or the like may be used as a means for varying the valve opening degree.

また、暖房能力の増加を室内熱交換器１３の温度を用い
て検知したが、本発明はそれに限定されるものではなく
、暖房能力の増加を検知できるものであれば、検出する
圧力、温度等の位置およびその手段は任意である。まだ
、除霜開始時期の決定についても同様である。Further, although the increase in heating capacity is detected using the temperature of the indoor heat exchanger 13, the present invention is not limited to this, and any pressure, temperature, etc. to be detected may be used as long as an increase in heating capacity can be detected. The location and means thereof are arbitrary. The same applies to the determination of when to start defrosting.

発明の効果 以上のように本発明のヒートポンプ式空調機は、圧縮機
、四方弁、室内熱交換器、絞り量を可変と転時に高圧と
なる前記圧縮機より前記室内熱交換器に至る配管と、同
じく暖房運転時に低圧となる前記室外熱交換器より圧縮
機に至る配管とを結ぶバイパス回路を形成し、前記バイ
パス回路に開閉弁を設け′て、前記室外熱交換器の除霜
運転開始時には前記絞り装置の絞り量を暖房運転時の絞
り量よりも小さくして前記開閉弁を開とし、室内ファン
の除霜運転開始時には前記絞り低下させ、除霜運転時に
前記室内ファンの風量を変化させたもので、除霜運転時
にも室内熱交換器に高温の吐出ガスの一部を流して暖房
運転継続可能として、圧縮機への多量の液戻りや液圧縮
を軽減し、室外熱交換器表面の温度分布を改善して一様
温度とする均一除霜を実現し、さらに室内ファンの風量
を可変として、長期にわたって信頼性が高く、しかも居
住者に不快感を与えることなく除霜効率を改善できる等
の種々の効果を有する。Effects of the Invention As described above, the heat pump air conditioner of the present invention includes a compressor, a four-way valve, an indoor heat exchanger, and piping from the compressor to the indoor heat exchanger that has a variable throttling amount and becomes high pressure when turned. Similarly, a bypass circuit is formed that connects the outdoor heat exchanger to the compressor, which has a low pressure during heating operation, and an on-off valve is provided in the bypass circuit, so that when the outdoor heat exchanger starts defrosting operation, The opening/closing valve is opened by making the throttling amount of the throttling device smaller than the throttling amount during heating operation, the throttling is lowered when defrosting operation of the indoor fan is started, and the air volume of the indoor fan is changed during defrosting operation. Even during defrosting operation, a portion of the high-temperature discharged gas is allowed to flow through the indoor heat exchanger to allow heating operation to continue, reducing the amount of liquid returned to the compressor and liquid compression, and reducing the amount of liquid on the outdoor heat exchanger surface. Improved temperature distribution to achieve uniform defrosting with a uniform temperature, and variable indoor fan air volume to improve defrosting efficiency with high reliability over a long period of time and without causing discomfort to occupants. It has various effects such as:

【図面の簡単な説明】[Brief explanation of drawings]

第１図は本発明の一実施例におけるヒートポンプ式空調
機の冷凍サイクル図、第２図は同ヒートポンプ式空調機
の除霜運転時のサイクルをモリエル線図上にあられした
図、第３図は同ヒートポンプ式空調機の除霜運転時の暖
房能力の変化を示す説明図、第４図は従来のヒートポン
プ式空調機の冷凍サイクル図、第５図は第４図に示す従
来のヒートポンプ式空調機の除霜運転時のサイクルをモ
リエル線図上にあられした図、第６図は同じ〈従来のヒ
ートポンプ式空調機の除霜運転時の暖房能力の変化を示
す説明図、第７図は同じ〈従来のヒートポンプ式空調機
の除霜運転時の高圧側圧力と低圧側圧力の変化を示す説
明図である。 １１・・・・・・圧縮機、１２・・・・・・四方弁、１
３・・・・・・室内熱交換器、１４・・・・・・鵡＝電
動膨張弁（低±酋絞り装置）、１５・・・・・・室外熱
交換器、１６・・・・・・バイパス回路、１７・・・・
・・開閉弁、１８・・・・・・室内ファン。 代理人の氏名　弁理士　中　尾　敏　男　ほか１名／１
−−−スＥ犀り１イク梵 ／ｚ−−−＋ｖ方升 ／３−一一室内数欠、７夫芥 ／４−−一嘩乞動Ａ紗匁ヒ書゛（紋）範Ｌ）Ａ５−一一
室タト熊夕；月（Ｓ特訓 柩　１　図　　　　　　　　　　　　　７ロ一−−八イ
ハ゛人１２１外／７−−−開ｒ１１４Ｔ ／ｌ−ｍ−室内７７） 第２図 緯閏 ／−−一用；Ｌ恢′；ｒ麦り績目彎 ２・・−ツ亨升 どｉ・−ｔ　７）　！　タ；（季（１嘔１６−−シトフ
トク゛入ハ゛イバ入Ｉ！ｌｌ落第５図 第６図 吋関Fig. 1 is a refrigeration cycle diagram of a heat pump air conditioner according to an embodiment of the present invention, Fig. 2 is a diagram showing the cycle during defrosting operation of the heat pump air conditioner on a Mollier diagram, and Fig. 3 is a diagram showing the cycle during defrosting operation of the heat pump air conditioner. An explanatory diagram showing changes in heating capacity during defrosting operation of the heat pump air conditioner, Figure 4 is a refrigeration cycle diagram of a conventional heat pump air conditioner, and Figure 5 is a diagram of the conventional heat pump air conditioner shown in Figure 4. Figure 6 shows the cycle during defrosting operation on a Mollier diagram. Figure 6 is the same. Figure 7 is an explanatory diagram showing changes in heating capacity during defrosting operation of a conventional heat pump air conditioner. FIG. 2 is an explanatory diagram showing changes in high-pressure side pressure and low-pressure side pressure during defrosting operation of a conventional heat pump air conditioner. 11...Compressor, 12...Four-way valve, 1
3... Indoor heat exchanger, 14... Paramotor = electric expansion valve (low ± 100% throttle device), 15... Outdoor heat exchanger, 16...・Bypass circuit, 17...
...Opening/closing valve, 18...Indoor fan. Name of agent: Patent attorney Toshio Nakao and 1 other person
---Su E 犀り 1 Ikubon / z --- + v square / 3-11 room number missing, 7 husband / 4--Ichigobebe A samonhi sho ゛ (crest) range L) A5-Room 11 Tato Kumasu; Moon (S training coffin 1 Figure 7 Ro 1--8 high person 121 outside/7---Open r114T/l-m-Indoor 77) Figure 2 Latitude leap/--1用；L 恢′;r 彯恢目彎2...-ツ亨升DOi・-t 7)! Ta;

Claims (2)

【特許請求の範囲】[Claims] （１）圧縮機、四方弁、室内熱交換器、暖房運転時と除
霜運転時に絞り量の異なる絞り装置、室外熱交換器等を
順次環状に配管で連結して冷凍サイクルを構成し、暖房
運転時に高圧となる前記圧縮機より前記室内熱交換器に
至る配管と、同じく暖房運転時に低圧となる前記室外熱
交換器より圧縮機に至る配管とを結ぶバイパス回路を形
成し、前記バイパス回路に開閉弁を設けて、前記室外熱
交換器の除霜運転開始時には前記絞り装置の絞り量を暖
房運転時の絞り量よりも小さくして前記開閉弁を開とし
、さらに室内ファンの風量を暖房運転時より低下させ、
除霜運転時には前記室内ファンの風量を変化させるヒー
トポンプ式空調機。(1) Compressor, four-way valve, indoor heat exchanger, throttling device with different throttling amounts during heating operation and defrosting operation, outdoor heat exchanger, etc. are connected in a ring in order to form a refrigeration cycle, and heating A bypass circuit is formed that connects piping from the compressor to the indoor heat exchanger, which is at high pressure during operation, and piping from the outdoor heat exchanger to the compressor, which is also at low pressure during heating operation, and the bypass circuit is connected to An on-off valve is provided, and when the outdoor heat exchanger starts defrosting operation, the throttling amount of the throttling device is made smaller than the throttling amount during heating operation to open the on-off valve, and the air volume of the indoor fan is changed to heating operation. lower than time,
A heat pump air conditioner that changes the air volume of the indoor fan during defrosting operation. （２）除霜運転時、暖房能力が設定値以上になると前記
室内ファンの風量を除霜開始時より低下させる特許請求
の範囲第１項記載のヒートポンプ式空調機。(2) The heat pump air conditioner according to claim 1, wherein during defrosting operation, when the heating capacity exceeds a set value, the air volume of the indoor fan is lowered than when defrosting is started.