JPS6229868A - 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、詳しくは低外気温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 relates to defrosting control for melting frost adhering to an outdoor heat exchanger at low outside temperatures. It is something.

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、大半が四方弁を切り換えて冷房サイクルとし
、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
ために室内ファンを停止していた。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
方弁が切り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。Conventional technology Most of the defrosting methods for outdoor heat exchangers in conventional air source heat pump air conditioners are reversed, in which a four-way valve is switched to create a cooling cycle, and the outdoor heat exchanger is used as a condenser and the indoor heat exchanger is used as an evaporator. It was a cyclic defrost system, and the indoor fan was stopped at this time to prevent cold drafts. 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. Users are not satisfied with the fact that 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、吐出ガスの残シを室外熱
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 in which a portion of the discharged gas from the compressor is passed through the indoor heat exchanger to maintain some heating capacity, while the remainder of the discharged gas is guided to the inlet of the outdoor heat exchanger for defrosting. have been proposed (for example, ``Japan Refrigeration Association Lecture Proceedings'').

９５９−１１．　　Ｐ、５３　）。959-11. 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、５は室外熱交換器、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, 5 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、低外気温時に室外熱交換器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。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 at low outside temperatures, the heating capacity decreases and a defrosting operation becomes necessary. The two-way valve 7 is opened to direct most of the high temperature discharged gas to the inlet side of the outdoor heat exchanger 5 via the hot gas bypass circuit 6.

同時に高温の吐出ガスの残シ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
を除霜した後、四方弁２を経て周波数可変圧縮機１に戻
シ除霜サイクルを完結する。At the same time, the remaining high-temperature discharged gas is passed through the four-way valve 2, the indoor heat exchanger 3, and the electric expansion valve 4 in the same way as during the heating operation, and a slight heating operation is continued, and the inlet side of the outdoor heat exchanger 5 is At a certain point C, most of the refrigerant branched on the high pressure side is merged with the refrigerant. After this combined refrigerant defrosts the outdoor heat exchanger with its own heat of condensation, it returns to the variable frequency compressor 1 via the four-way valve 2, completing the defrosting 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
。Problems to be Solved by the Invention However, the above configuration has the following problems.

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サイクルをモリエル線図上に示した
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。FIG. 5 is a Mollier diagram showing the cycle during defrosting operation of the conventional heat pump type air conditioner shown in FIG. Symbols a to 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５の入口側の点Ｃで合流し、この点Ｃ
は温度の高い過熱域に存在する。In other words, 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 5;
exists in the superheated region.

ここで冷媒はｉｃなるエンタルピを持つ。そして凝縮後
、つまシ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となシ、この液分の多い乾
き度Ｘ。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憂ζなる。Here, the refrigerant has an enthalpy of ic. After condensation, the state of the refrigerant after defrosting changes to a point d with a high liquid content in the two-phase region, and reaches a point e after pressure loss, which is the dryness X with a high liquid content. It is a concern that the refrigerant is sucked into the variable frequency compressor 1 as it is, so a considerable amount of liquid compression is 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一点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, considering the usage status of refrigerant during defrosting (points C and d), the sensible heat (superheat region) and latent heat (two-phase region) of the refrigerant are used, and when the frost melts, drain water begins to drip. Outdoor heat exchanger 5 during late frost
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図は前記従来のヒートポンプ式空調機の除霜運
転時の室内熱交換器３内の冷媒圧力と室外熱交換器５内
の冷媒圧力の変化を示す。Further, FIG. 6 shows changes in the refrigerant pressure in the indoor heat exchanger 3 and the refrigerant pressure in the outdoor heat exchanger 5 during defrosting operation of the conventional heat pump type air conditioner.

同図においてＡは室内熱交換器３内の冷媒圧力、Ｂは室
外熱交換器ｓ内の冷媒圧力を示しておシ、圧力Ｂは除霜
運転を開始すると約０℃の飽和圧力となシ、時刻ｔ、ま
でほぼその状態を保つ。時刻ｔ１　になるまでには室外
熱交換器５の表面に付着した霜はほとんど融解し、ドレ
ン水が滴下している。したがってそれ以降、圧力Ｂは徐
々に上昇するが、ドレン水を完全に滴下させ、室外熱交
換器５の表面を乾燥させるために室外熱交換器５が所定
の温度または圧力になるまで除霜運転を続ける。In the figure, A indicates the refrigerant pressure in the indoor heat exchanger 3, B indicates the refrigerant pressure in the outdoor heat exchanger s, and the pressure B is the saturated pressure of about 0°C when defrosting operation starts. , and maintains almost the same state until time t. By time t1, most of the frost adhering to the surface of the outdoor heat exchanger 5 has melted, and drain water is dripping. Therefore, from then on, the pressure B gradually increases, but in order to completely drip the drain water and dry the surface of the outdoor heat exchanger 5, the defrosting operation is performed until the outdoor heat exchanger 5 reaches a predetermined temperature or pressure. Continue.

しかし、この時室内熱交換器ａと電動膨張弁４を結ぶ配
管や電動膨張弁４と室外熱交換器５を結ぶ配管等を冷媒
が通る際の圧力損失のために圧力Ｂは常に圧力Ａより小
さく、したがって室外熱交換器５が所定の温度または圧
力になるまでにかなシの時間を要する。このために全体
の除霜時間が長くなシ、また室外熱交換器５の表面から
大気への自然放熱量も大きくなって除霜性能を低下させ
ている。However, at this time, the pressure B is always lower than the pressure A due to pressure loss when the refrigerant passes through the pipes connecting the indoor heat exchanger a and the electric expansion valve 4 and the pipes connecting the electric expansion valve 4 and the outdoor heat exchanger 5. It is small, so it takes a long time for the outdoor heat exchanger 5 to reach a predetermined temperature or pressure. For this reason, the entire defrosting time is long, and the amount of natural heat radiated from the surface of the outdoor heat exchanger 5 to the atmosphere is also increased, reducing the defrosting performance.

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シや液圧縮を軽減し、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、除霜運転終了前に室外熱交換器より圧縮
機に至る配管に設けた開閉弁を閉とすることで室外熱交
換器の温度、圧力を急速に上昇させて除霜時間を短縮し
、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 even during defrosting operation, allowing heating operation to continue, thereby reducing a large amount of liquid returned 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, and closes the on-off valve installed in the piping from the outdoor heat exchanger to the compressor before the end of defrosting operation. This provides a heat pump type air conditioner that rapidly increases the temperature and pressure of the outdoor heat exchanger, shortens the defrosting time, and improves the defrosting efficiency.

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、暖房運転時に低圧となる
前記室外熱交換器より圧縮機に至る配管に第１の開閉弁
を設け、さらに暖房運転時（こ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〔
こ低圧となる前記室外熱交換器より圧縮機（ζ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第
２の開閉弁を設けて、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凰より
も小さくして前記第２の開閉弁を開とし、除霜運転終了
前に前記第１の開閉弁を閉としたものである。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 first on-off valve is provided in the piping leading from the outdoor heat exchanger, which is at low pressure during heating operation, to the compressor. The piping from the compressor to the indoor heat exchanger is also connected during heating operation [
A bypass circuit is formed that connects the outdoor heat exchanger to the compressor (ζ), which has a low pressure, and a second on-off valve is provided in the bypass circuit, so that when the outdoor heat exchanger starts defrosting operation, the The second opening/closing valve is opened by making the throttling amount of the throttle device smaller than that during heating operation, and the first opening/closing valve is closed before the end of defrosting operation.

作　　用 本発明は上記構成により、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
、絞り装置の絞りを小さくして、高温の吐出ガスの残シ
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が乾き度を大きくでき、液戻シ
や液圧縮を軽減できる。Effect of the Invention With the above-mentioned configuration, the present invention allows part of the high temperature discharged gas to flow into the indoor heat exchanger even during defrosting operation to continue the heating operation, and reduces the diaphragm of the throttle device to remove the remaining high temperature discharged gas. Since the refrigerant is returned directly to the outdoor heat exchanger outlet, which is the compressor suction side, the refrigerant circulation is good, and while the compressor input is maintained, the dryness of the compressor suction refrigerant can be increased, although it is two-phase. and liquid compression can be reduced.

また室外熱交換器への流入冷媒も二相となシ、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
燥期ま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とがなくなシ、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。In addition, since the refrigerant flowing into the outdoor heat exchanger is two-phase, the temperature on the surface of the outdoor heat exchanger rises uniformly and evenly from the early and middle stages of defrosting, as well as from the latter stages when drain water is dripping after melting to the drying stage. This prevents the temperature of a portion from rising rapidly before returning to the heating operation, and convection heat loss to the surroundings is suppressed to the extent that the defrosting efficiency can be improved.

さらに、除霜運転終了前に室外熱交換器より圧縮機に至
る配管に設けた開閉弁を閉とすることで室外熱交換器の
温度、圧力を急速に上昇させ、除霜時間が短縮できるの
で、除霜効率を大巾に改善することができる。Furthermore, by closing the on-off valve installed in the piping from the outdoor heat exchanger to the compressor before the end of defrosting operation, the temperature and pressure of the outdoor heat exchanger can be rapidly increased, shortening the defrosting time. , the defrosting efficiency can be greatly 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は室外熱交換器、１６は第１の開閉弁、１７
はバイパス回路、１８は第２の開閉弁である。また１９
は室外熱交換器ＩＳＯ温度を検知する室外温度検出素子
であシ、２０はこの室外温度検出素子１９の温度信号を
受けて電動膨張弁１４の弁開度および第１．第２の開閉
弁１８．１８の開閉を制御する制御回路である。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, and 16 is a first on-off valve. , 17
18 is a bypass circuit, and 18 is a second on-off valve. Also 19
20 is an outdoor temperature detection element that detects the ISO temperature of the outdoor heat exchanger, and 20 receives the temperature signal from this outdoor temperature detection element 19 to determine the valve opening degree of the electric expansion valve 14 and the first. This is a control circuit that controls opening and closing of the second on-off valve 18.18.

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１６を順次環状に連結し
、室外熱交換器１５より圧縮機１１に至る配管に第１の
開閉弁１６を設け、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、その途中に第２の
開閉弁１８を備えたバイパス回路１７を設けたものであ
る。And a compressor 11, a four-way valve 12, an indoor heat exchanger 13,
The electric expansion valve 14 and the outdoor heat exchanger 16 are sequentially connected in an annular manner, and a first on-off valve 16 is provided in the pipe leading from the outdoor heat exchanger 15 to the compressor 11, so that the discharge side of the compressor 11 and the outdoor heat exchanger are connected. 15 is connected to the outlet side during heating operation, and a bypass circuit 17 provided with a second on-off valve 18 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第１の開閉弁１６は開、第２の開
閉弁１８は閉となっており、冷媒は圧縮機１１、四方弁
１２、室内交換器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１１ζこ戻シ暖房サイ
クルを形成し、〕寸イｔ＜’ス回路１７には冷媒は流れ
ない。During normal heating operation, the first on-off valve 16 is open and the second on-off valve 18 is closed, and the refrigerant is supplied to the compressor 11, four-way valve 12, indoor exchanger 13, electric expansion valve 14, and outdoor heat exchanger. The refrigerant flows through the compressor 11 and the four-way valve 12 to form a heating cycle, and no refrigerant flows into the space circuit 17.

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１９が設定値まで下がると制御回
路２０が除霜開始指令を発し、四方弁１２はそのままの
状態で第２の開閉弁１８を開として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、残シは室外熱交換器１５の出口側へ導くとともに、
電動脳張弁１４の弁開度を開方向にすることで絞り量を
小さくして除霜を開始する。However, when the outdoor temperature is low, frost forms on the outdoor heat exchanger 15, and when the outdoor temperature detection element 19 drops to the set value, the control circuit 20 issues a command to start defrosting, and the four-way valve 12 remains in the second position. The on-off valve 18 is opened to branch the high-temperature discharged gas at point a', a part of which flows directly to the indoor heat exchanger 13, and the remainder is guided to the outlet side of the outdoor heat exchanger 15.
Defrosting is started by reducing the throttle amount by setting the valve opening degree of the electric brain expansion valve 14 in the opening direction.

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。同図（こ示す記号ａ′〜ｅ′は第１図に示
したものと対応する。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. 1 (the symbols a' to e' correspond to those shown in FIG. 1).

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°Ｃ）で凝縮放熱し、点ｂ’ｉこ移り図示しない
室内ファンのＯＮにより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ＣＩ
となり室外熱交換器１５（こ流入して、さらに霜の融解
温度である約０°Ｃで凝縮放熱して、除霜し点ｄ′に配
る。この時の除霜に利用する冷媒のエンタルピ差はΔ１
ｄｅｆ＝１ｏｔ−１ｄｌ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　ａＩ　−ｉ　ｂ／となる
。That is, during defrosting operation, the high temperature discharge gas that flows directly from point a' to the indoor heat exchanger 13 has a relatively low temperature (approximately 30
The heating operation can be continued by turning on the indoor fan (not shown) from point b'i. The pressure is reduced by the piping in the middle or a slight restriction of the electric expansion valve 14, and the pressure is reduced to point CI.
Then, it flows into the outdoor heat exchanger 15 (this heat is further condensed at about 0°C, which is the melting temperature of frost, and distributed to the defrosting point d'. At this time, the enthalpy difference of the refrigerant used for defrosting is is Δ1
def=1ot-1dl, and the state of the refrigerant flowing into the outdoor heat exchanger 15 is already two-phase as shown at point C'. Incidentally, the enthalpy difference of the refrigerant used for room heating is i aI - i b/ if heat loss during the process is ignored.

一方残シの高温の吐出ガスは室外熱交換器１５のムロ側
に導かれるのではゾ等エンタルピ変化後、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Ｘ。Ｉが大きく液分が少ないので液戻
りや液圧縮を軽減または実質的に回避することができる
。さらにまた除１ｉ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シ、同表面温
度にムラ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 muro side of the outdoor heat exchanger 15, and after undergoing a zoisoenthalpy 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. This point e' is the refrigerant dryness X even though it is in a two-phase state. Since I is large and the liquid content is small, liquid return and liquid compression can be reduced or substantially avoided. Furthermore, since the refrigerant flowing into the outdoor heat exchanger 15 during the 1i 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.

さて、除霜運転中は、室外熱交換器１５の表面に付着し
た箱がほとんど融解するまで室外熱交換器１５内の冷媒
圧力は約０°Ｃの飽和圧力を保つが、それ以降徐々に上
昇する。したがって室外熱交換器１５の温度も上昇し、
この温度上昇を室外温度　　　　゛検出素子１９で検知
し７て第１の開閉弁１６を閉とする。このため、室外熱
交換器１５内の冷媒圧力は高圧側の室内熱交換器１３内
の冷媒圧力と等しくなるまで急激）こ上昇し、室外熱交
換器１５の温度も急激（こ上昇し、設定温度になると室
外温度検出素子１９より信号を受けて制御回路は除霜終
了Ｉ旨令を発し、前述の通常の暖房運転に復帰する。Now, during defrosting operation, the refrigerant pressure inside the outdoor heat exchanger 15 maintains a saturation pressure of about 0°C until the box attached to the surface of the outdoor heat exchanger 15 is almost melted, but after that it gradually increases. do. Therefore, the temperature of the outdoor heat exchanger 15 also rises,
This temperature rise is detected by the outdoor temperature detection element 19, and the first on-off valve 16 is closed. Therefore, the refrigerant pressure in the outdoor heat exchanger 15 rises rapidly until it becomes equal to the refrigerant pressure in the indoor heat exchanger 13 on the high-pressure side, and the temperature of the outdoor heat exchanger 15 also rises rapidly and When the temperature reaches the temperature, the control circuit receives a signal from the outdoor temperature detection element 19, issues a defrosting end command I, and returns to the above-mentioned normal heating operation.

第３図は、本実施例の除霜運転中の室外熱交換器１５内
および室内熱交換器１３内の冷媒圧力変化を示す。FIG. 3 shows changes in refrigerant pressure inside the outdoor heat exchanger 15 and inside the indoor heat exchanger 13 during the defrosting operation of this embodiment.

同図において圧力Ｃは室内熱交換器１３内の冷媒圧力を
示し、圧力りは室外熱交換器１５内の冷媒圧力を示し、
それぞれ実線が本実施例の場合、破線が従来の技術の項
で説明した実施例の場合を示す。In the figure, pressure C indicates the refrigerant pressure in the indoor heat exchanger 13, pressure C indicates the refrigerant pressure in the outdoor heat exchanger 15,
The solid line indicates this embodiment, and the broken line indicates the embodiment described in the prior art section.

除霜運転中　室外熱交換器１５の温度上昇を室外温度検
出素子１９より検知して時刻ｔ２で第１の開閉弁を閉と
する。このため、圧力りは急激に上昇し、室外熱交換器
１５の温度も急激に上昇するので、同図に示すように暖
房復帰温度又は圧力に速やかに到達し、従来より短時間
で除霜を終了した後暖房運転に復帰する。したがって室
外熱交換器１５の表面から大気への自然放熱量も少なく
除霜効率の改善を計ることができる。During defrosting operation, a temperature rise in the outdoor heat exchanger 15 is detected by the outdoor temperature detection element 19, and the first on-off valve is closed at time t2. For this reason, the pressure rises rapidly and the temperature of the outdoor heat exchanger 15 also rises rapidly, so that the heating return temperature or pressure is quickly reached as shown in the figure, and defrosting is completed in a shorter time than before. After finishing, heating operation will be resumed. Therefore, the amount of natural heat released from the surface of the outdoor heat exchanger 15 to the atmosphere is also small, and the defrosting efficiency can be improved.

なお、本発明は絞り量を可変とした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。また、室外温度検出素
子１９の温度信号により第１の開閉弁１６を閉としたが
、本発明はそれに限定されるものではなく、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。また除
霜開始時期、終了時期の決定についても同様である。Although the present invention has been described using an electric expansion valve 14 that uses electromagnetic force as a driving source and has a variable valve opening degree as the best form of a throttle device with a variable throttle amount, it is also possible to use a plurality of throttles such as capillaries. may be configured and controlled by appropriate switching.
Further, a bimetal, a shape memory alloy, or the like may be used as a means for varying the valve opening degree. Further, although the first on-off valve 16 was closed by the temperature signal from the outdoor temperature detection element 19, the present invention is not limited thereto, and the position and means for detecting pressure, temperature, etc. are arbitrary. The same applies to the determination of the defrosting start time and defrosting end time.

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、絞り量を可変とした絞り装誼
、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、暖房運転時警こ低圧となる前記室外熱交
換器より圧縮機に至る配管に第１の開閉弁を設け、さら
に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第２の開閉弁を設け
て前記室外熱交換器の徐開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第
２の開閉弁を開とし、除霜運転終了前に前記第１の開閉
弁を開としたもので、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シや液圧縮を軽減し、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、さらに除霜運転終了前に室外熱交換器より圧縮
機に至る配管に設けた開閉弁を閉とすることで室外熱交
換器の温度、圧力を急速に上昇させて除霜時間を短縮で
き、除霜効率を改善させる等の効果を有する。Effects of the Invention As described above, the heat pump air conditioner of the present invention sequentially connects a compressor, a four-way valve, an indoor heat exchanger, a throttling system with a variable throttling amount, an outdoor heat exchanger, etc. in an annular manner through piping. A first on-off valve is provided in the piping leading from the outdoor heat exchanger, which is at low pressure during heating operation, to the compressor, and the indoor heat exchanger is further connected to the indoor heat exchanger from the compressor, which is at high pressure during heating operation. A bypass circuit is formed between the piping leading to the compressor and the piping leading from the outdoor heat exchanger to the compressor, which also has low pressure during heating operation, and a second on-off valve is provided in the bypass circuit to reduce the outdoor heat. When starting the gradual opening operation of the exchanger, the throttling amount of the throttling device is made smaller than the throttling amount during the heating operation to open the second on-off valve, and before the end of the defrosting operation, the first on-off valve is opened. Even during defrosting operation, a portion of the high-temperature discharged gas is passed through the indoor heat exchanger to allow heating operation to continue.
It reduces the large amount of liquid returned to the compressor and liquid compression, improves the temperature distribution on the surface of the outdoor heat exchanger, achieves uniform defrosting with a uniform temperature, and also allows outdoor heat exchange before the end of defrosting operation. By closing the on-off valve installed in the piping from the heat exchanger to the compressor, the temperature and pressure of the outdoor heat exchanger can be rapidly increased, reducing defrosting time and improving defrosting efficiency. .

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

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
説明図、第３図は同ヒートポンプ式空調機の除霜運転時
の室内熱交換器内冷媒圧力および室外熱交換器内冷媒圧
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説明図、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室内熱交換器内冷
媒圧力および室外熱交換器内冷媒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・・・・・・電動膨張
弁（絞り装置）、１５・・・・・・室外熱交換器、１６
・・・・・第１の開閉弁、１７・・・・・バイパス回路
、１８・・団・第２の開閉弁。 代理人の氏名　弁理士　中　尾　敏　男　ほか１２勾　
　　　　　　　　〇− 第３図 第４図 第５図Fig. 1 is a refrigeration cycle diagram of a heat pump air conditioner according to an embodiment of the present invention, Fig. 2 is an explanatory diagram showing the cycle during defrosting operation of the heat pump air conditioner on a Mollier diagram, and Fig. 3 is an explanatory diagram showing changes in the refrigerant pressure in the indoor heat exchanger and the refrigerant pressure in the outdoor heat exchanger during defrosting operation of the heat pump air conditioner, and Figure 4 is a refrigeration cycle diagram of the conventional heat pump air conditioner. Figure 5 is an explanatory diagram showing the defrosting operation cycle of the conventional heat pump air conditioner shown in Figure 4 on a Mollier diagram, and Figure 6 is the same (defrosting operation cycle of the conventional heat pump air conditioner). It is an explanatory diagram showing changes in the refrigerant pressure in the indoor heat exchanger and the refrigerant pressure in the outdoor heat exchanger. 11... Compressor, 12... Four-way valve, 1
3...Indoor heat exchanger, 14...Electric expansion valve (throttle device), 15...Outdoor heat exchanger, 16
...First on-off valve, 17... Bypass circuit, 18... Group, second on-off valve. Name of agent: Patent attorney Toshio Nakao and 12 others
〇- Figure 3 Figure 4 Figure 5

Claims (1)

【特許請求の範囲】[Claims] 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、暖房運転時に低圧となる前記室外
熱交換器より圧縮機に至る配管に第１の開閉弁を設け、
さらに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第２の開閉弁を設
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
記第２の開閉弁を開とし、除霜運転終了前に前記第１の
開閉弁を閉としたヒートポンプ式空調機。A compressor, a four-way valve, an indoor heat exchanger, a throttling device with a variable throttling amount, an outdoor heat exchanger, etc. are sequentially connected in a ring shape with piping to form a refrigeration cycle, and the outdoor heat exchanger has a low pressure during heating operation. A first on-off valve is installed in the piping leading from the compressor to the compressor.
Furthermore, a bypass circuit is formed that connects piping from the compressor to the indoor heat exchanger, which is at high pressure during heating operation, and piping from the outdoor heat exchanger to the compressor, which is also at low pressure during heating operation, and a second on-off valve is provided in the circuit, 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 second on-off valve; A heat pump air conditioner in which the first on-off valve is closed before the defrosting operation ends.