JP2010164257A

JP2010164257A - Refrigerating cycle device and method of controlling the refrigerating cycle device

Info

Publication number: JP2010164257A
Application number: JP2009007593A
Authority: JP
Inventors: Naofumi Takenaka; 直史竹中; Masanori Aoki; 正則青木; Takashi Okazaki; 多佳志岡崎; Yoshihiro Takahashi; 佳宏高橋; Kengo Takahashi; 建吾高橋; Kazuki Okada; 和樹岡田; Shinichi Uchino; 進一内野; So Nomoto; 宗野本; Shinichi Wakamoto; 慎一若本
Original assignee: Mitsubishi Electric Corp
Current assignee: Mitsubishi Electric Corp
Priority date: 2009-01-16
Filing date: 2009-01-16
Publication date: 2010-07-29

Abstract

<P>PROBLEM TO BE SOLVED: To provide a refrigerating cycle device improving average capacity and an average COP to save energy by reducing a change range between refrigerant distribution during normal operation and refrigerant distribution during defrosting operation within a refrigerating cycle. <P>SOLUTION: The refrigerating cycle device 100 includes a control device 20 for executing defrosting operation by closing a first expansion valve 3 and a second expansion valve 5 and controlling an opening of a bypass expansion valve 8 in accordance with superheating degree (SH) of a refrigerant sucked to a compressor 1 or a superheating degree (SH) of a refrigerant discharged from the compressor 1. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

本発明は、給湯運転を実行するヒートポンプ式給湯装置や空調運転（たとえば、暖房運転や冷房運転）を実行するヒートポンプ式空気調和装置等の冷凍サイクル装置及び冷凍サイクル装置の制御方法に関し、特に室外熱交換器の着霜状態を解消するデフロスト運転による性能低下を抑制するようにした冷凍サイクル装置及び冷凍サイクル装置の制御方法に関するものである。 The present invention relates to a refrigeration cycle apparatus such as a heat pump type hot water supply apparatus that performs a hot water supply operation and a heat pump type air conditioner that performs an air conditioning operation (for example, a heating operation or a cooling operation), and a control method for the refrigeration cycle apparatus, and particularly to outdoor heat. The present invention relates to a refrigeration cycle apparatus and a control method for the refrigeration cycle apparatus that suppress performance degradation due to defrost operation that eliminates the frosting state of the exchanger.

通常、冷凍サイクル装置において、外気温度が低い状態で給湯運転や暖房運転を行なっていると、蒸発器として機能している室外熱交換器に霜が付着する着霜現象が起きる。このような着霜現象が起きると、室外熱交換器における通風抵抗の増加及び熱抵抗の増加を招くことになり、熱交換効率が低下し、冷凍サイクル装置の性能が低下してしまう。そこで、冷凍サイクル装置では、一般的に、室外熱交換器に付着した霜を取り除くデフロスト運転を実行するようになっている。 Usually, in a refrigeration cycle apparatus, when hot water supply operation or heating operation is performed in a state where the outside air temperature is low, a frosting phenomenon in which frost adheres to an outdoor heat exchanger functioning as an evaporator occurs. When such a frosting phenomenon occurs, an increase in ventilation resistance and an increase in thermal resistance in the outdoor heat exchanger are caused, resulting in a decrease in heat exchange efficiency and a decrease in performance of the refrigeration cycle apparatus. Therefore, in the refrigeration cycle apparatus, generally, a defrost operation for removing frost attached to the outdoor heat exchanger is executed.

デフロスト運転の方法としては、圧縮機から吐出された冷媒を、凝縮器（室内熱交換器）をバイパスさせ、蒸発器（室外熱交換器）に直接流入させるホットガスバイパス運転が知られている（たとえば、特許文献１参照）。この特許文献１に記載されている冷媒回路には、圧縮機、水熱交換器、レシーバー、膨張弁、及び、室外熱交換器が備えられている。この冷媒回路に、レシーバーの上流に水熱交換器から流出した冷媒と室外熱交換器から流出した冷媒とで熱交換を行う冷媒―冷媒熱交換器と、圧縮機で吐出された冷媒を直接室外熱交換器に流入させるバイパス配管と、膨張弁（デフロスト弁）と、が設けられている。そして、デフロスト運転は、レシーバー出口の膨張弁を閉止して、バイパス配管の膨張弁を開けることにより行なわれるようになっている。 As a method of defrost operation, hot gas bypass operation is known in which refrigerant discharged from a compressor is bypassed through a condenser (indoor heat exchanger) and directly flows into an evaporator (outdoor heat exchanger) ( For example, see Patent Document 1). The refrigerant circuit described in Patent Document 1 includes a compressor, a water heat exchanger, a receiver, an expansion valve, and an outdoor heat exchanger. In this refrigerant circuit, the refrigerant-refrigerant heat exchanger that exchanges heat between the refrigerant that flows out of the water heat exchanger and the refrigerant that flows out of the outdoor heat exchanger upstream of the receiver, and the refrigerant discharged from the compressor directly A bypass pipe that flows into the heat exchanger and an expansion valve (defrost valve) are provided. The defrosting operation is performed by closing the expansion valve at the receiver outlet and opening the expansion valve at the bypass pipe.

また、四方弁を切り替え、凝縮器（室内熱交換器）と蒸発器（室外熱交換器）とを入れ替え、圧縮機から吐出した冷媒を室外熱交換器に流入させるリバース運転が知られている（たとえば、特許文献２参照）。この特許文献２に記載されている冷媒回路には、圧縮機、四方弁、水熱交換器、第１の膨張弁、レシーバー、第２の膨張弁、及び、室外熱交換器が備えられている。そして、デフロスト運転は、圧縮機から吐出された冷媒が、直接室外熱交換器に流入するように四方弁を切り替え、また、第１の膨張弁、及び、第２の膨張弁を全開することにより行なわれるようになっている。 Also, reverse operation is known in which the four-way valve is switched, the condenser (indoor heat exchanger) and the evaporator (outdoor heat exchanger) are replaced, and the refrigerant discharged from the compressor flows into the outdoor heat exchanger ( For example, see Patent Document 2). The refrigerant circuit described in Patent Document 2 includes a compressor, a four-way valve, a water heat exchanger, a first expansion valve, a receiver, a second expansion valve, and an outdoor heat exchanger. . In the defrost operation, the four-way valve is switched so that the refrigerant discharged from the compressor flows directly into the outdoor heat exchanger, and the first expansion valve and the second expansion valve are fully opened. It is supposed to be done.

特開２００３−６５６１６号公報（第４頁、第１図）JP 2003-65616 A (Page 4, FIG. 1) 特開２００８−８２６５３号公報（第１０頁、第１図）JP 2008-82653 A (page 10, FIG. 1)

通常運転（給湯運転や暖房運転）とデフロスト運転を含めた平均能力及び平均ＣＯＰを向上させるためには、通常運転時の冷媒分布とデフロスト運転時の冷媒分布をできるだけ変化させずに、通常運転への復帰後に素早く暖房能力を回復させることが要求される。しかしながら、特許文献１に記載されているような冷凍サイクル装置では、低圧側の冷媒と熱交換する要素機器（冷媒―冷媒熱交換器）が高圧側にあるため、高圧側の要素機器にある冷媒が冷やされ、高圧側圧力が低下してしまう。つまり、通常運転時の冷媒分布とデフロスト運転時の冷媒分布とが大きく変化してしまい、通常運転への復帰後に素早く暖房能力を回復させることができないことになる。 To improve the average capacity and average COP including normal operation (hot water supply operation and heating operation) and defrost operation, change the refrigerant distribution during normal operation and refrigerant distribution during defrost operation as much as possible to normal operation. It is required to quickly recover the heating capacity after returning to the factory. However, in the refrigeration cycle apparatus as described in Patent Document 1, since the element device (refrigerant-refrigerant heat exchanger) that exchanges heat with the low-pressure side refrigerant is on the high-pressure side, the refrigerant in the high-pressure side element device Is cooled, and the pressure on the high pressure side decreases. That is, the refrigerant distribution during the normal operation and the refrigerant distribution during the defrost operation greatly change, and the heating capacity cannot be quickly recovered after returning to the normal operation.

また、特許文献２に記載されているような冷凍サイクル装置では、デフロスト運転時に冷媒の流れを逆にするため、通常運転時の冷媒分布とデフロスト運転時の冷媒分布とが大きく変化してしまい、通常運転への復帰後に素早く暖房能力を回復させることができないことになる。このように、従来の技術では、冷凍サイクル内における通常運転時の冷媒分布とデフロスト運転時の冷媒分布とが大きく変化し、冷凍サイクル内の冷媒分布の変化によるエネルギーロスが発生してしまう。 Further, in the refrigeration cycle apparatus described in Patent Document 2, in order to reverse the flow of the refrigerant during the defrost operation, the refrigerant distribution during the normal operation and the refrigerant distribution during the defrost operation greatly change, The heating capacity cannot be quickly recovered after returning to normal operation. As described above, in the conventional technique, the refrigerant distribution during normal operation and the refrigerant distribution during defrost operation in the refrigeration cycle change greatly, and energy loss occurs due to the change in refrigerant distribution in the refrigeration cycle.

本発明は、上記のような課題を解決するためになされたもので、冷凍サイクル内における通常運転時の冷媒分布とデフロスト運転時の冷媒分布との変化幅を低減することで、平均能力及び平均ＣＯＰを向上させ、省エネルギー化を図るようにした冷凍サイクル装置及び冷凍サイクル装置の制御方法を提供することを目的としている。 The present invention has been made in order to solve the above-described problems, and by reducing the change width between the refrigerant distribution during normal operation and the refrigerant distribution during defrost operation in the refrigeration cycle, the average capacity and average are reduced. An object of the present invention is to provide a refrigeration cycle apparatus and a refrigeration cycle apparatus control method that improve COP and save energy.

本発明に係る冷凍サイクル装置は、圧縮機、負荷側熱交換器、第１膨張弁、レシーバー、第２膨張弁、及び、熱源側熱交換器が順次接続された冷媒回路を有し、前記第１膨張弁と前記第２膨張弁とを接続している中圧管を流れる冷媒と前記圧縮機の吸入配管を流れる冷媒とを熱交換させる冷媒−冷媒熱交換器と、前記圧縮機の吐出配管と、前記第２膨張弁と前記熱源側熱交換器とを接続している低圧管とを、接続するバイパス配管と、前記バイパス配管に設けられたバイパス膨張弁と、前記第１膨張弁及び前記第２膨張弁を閉止し、前記バイパス膨張弁の開度を前記圧縮機に吸入される冷媒の過熱度又は前記圧縮機を吐出した冷媒の過熱度に応じて制御することでデフロスト運転を実行する制御装置と、を備えたことを特徴とする。 A refrigeration cycle apparatus according to the present invention includes a refrigerant circuit in which a compressor, a load-side heat exchanger, a first expansion valve, a receiver, a second expansion valve, and a heat source-side heat exchanger are sequentially connected. A refrigerant-refrigerant heat exchanger for exchanging heat between the refrigerant flowing through the intermediate pressure pipe connecting the first expansion valve and the second expansion valve and the refrigerant flowing through the suction pipe of the compressor; and a discharge pipe of the compressor A bypass pipe connecting the second expansion valve and the low pressure pipe connecting the heat source side heat exchanger, a bypass expansion valve provided in the bypass pipe, the first expansion valve, and the first Control that performs defrost operation by closing the expansion valve and controlling the degree of opening of the bypass expansion valve in accordance with the degree of superheat of the refrigerant sucked into the compressor or the degree of superheat of the refrigerant discharged from the compressor And a device.

本発明に係る冷凍サイクル装置の制御方法は、圧縮機、負荷側熱交換器、第１膨張弁、レシーバー、第２膨張弁、及び、熱源側熱交換器が順次接続された冷媒回路を有し、前記第１膨張弁と前記第２膨張弁とを接続している中圧管を流れる冷媒と前記圧縮機の吸入配管を流れる冷媒とを熱交換させる冷媒−冷媒熱交換器と、前記圧縮機の吐出配管と、前記第２膨張弁と前記熱源側熱交換器とを接続している低圧管とを、接続するバイパス配管と、前記バイパス配管に設けられたバイパス膨張弁と、前記圧縮機の周波数、前記第１膨張弁の開度、前記第２膨張弁の開度、及び、前記バイパス膨張弁の開度を制御する制御装置と、を備え、前記制御装置は、前記第１膨張弁及び前記第２膨張弁を閉止し、前記バイパス膨張弁の開度を前記圧縮機に吸入される冷媒の過熱度又は前記圧縮機を吐出した冷媒の過熱度に応じて制御することでデフロスト運転を実行することを特徴とする。 The control method of the refrigeration cycle apparatus according to the present invention includes a refrigerant circuit in which a compressor, a load side heat exchanger, a first expansion valve, a receiver, a second expansion valve, and a heat source side heat exchanger are sequentially connected. A refrigerant-refrigerant heat exchanger for exchanging heat between the refrigerant flowing through the intermediate pressure pipe connecting the first expansion valve and the second expansion valve and the refrigerant flowing through the suction pipe of the compressor; A bypass pipe for connecting a discharge pipe, a low-pressure pipe connecting the second expansion valve and the heat source side heat exchanger, a bypass expansion valve provided in the bypass pipe, and a frequency of the compressor A control device that controls the opening of the first expansion valve, the opening of the second expansion valve, and the opening of the bypass expansion valve, and the control device includes the first expansion valve and the The second expansion valve is closed and the opening of the bypass expansion valve is set to the compressor. And executes the defrosting operation by controlling in accordance with the degree of superheat or the degree of superheat of refrigerant discharged the compressor of the refrigerant inlet.

本発明に係る冷凍サイクル装置によれば、デフロスト運転中、レシーバー内に閉じ込められた冷媒が、圧縮機に吸入される冷媒と熱交換するため、冷熱をレシーバーに溜めることができる。また、凝縮器として機能する負荷側熱交換器に滞留した冷媒の状態は変化しないため、運転の切り替えによる冷媒の移動を最小限に抑えることができ、性能の低下を小さくできる。 According to the refrigeration cycle apparatus according to the present invention, during the defrost operation, the refrigerant confined in the receiver exchanges heat with the refrigerant sucked into the compressor, so that cold heat can be stored in the receiver. Further, since the state of the refrigerant staying in the load-side heat exchanger functioning as a condenser does not change, the movement of the refrigerant due to the switching of operation can be suppressed to a minimum, and the performance degradation can be reduced.

本発明に係る冷凍サイクル装置の制御方法によれば、デフロスト運転中、レシーバー内に閉じ込められた冷媒が、圧縮機に吸入される冷媒と熱交換するため、冷熱をレシーバーに溜めることができる。また、凝縮器として機能する負荷側熱交換器に滞留した冷媒の状態は変化しないため、運転の切り替えによる冷媒の移動を最小限に抑えることができ、性能の低下を小さくできる。 According to the control method of the refrigeration cycle apparatus according to the present invention, during the defrost operation, the refrigerant confined in the receiver exchanges heat with the refrigerant sucked into the compressor, so that cold heat can be stored in the receiver. Further, since the state of the refrigerant staying in the load-side heat exchanger functioning as a condenser does not change, the movement of the refrigerant due to the switching of operation can be suppressed to a minimum, and the performance degradation can be reduced.

実施の形態１に係るヒートポンプ式給湯装置のヒートポンプ部分を示す冷媒回路図である。3 is a refrigerant circuit diagram illustrating a heat pump portion of the heat pump hot water supply apparatus according to Embodiment 1. FIG. 給湯運転時における各アクチュエータの制御パターンを示す表である。It is a table | surface which shows the control pattern of each actuator at the time of hot water supply driving | operation. 第１のデフロスト運転時における各アクチュエータの制御パターンを示す表である。It is a table | surface which shows the control pattern of each actuator at the time of a 1st defrost driving | operation. Ｒ４１０Ａ冷媒の状態を示すＰ−ｈ線図である。It is a Ph diagram which shows the state of R410A refrigerant. レシーバーの熱容量と冷媒密度との関係を示すグラフである。It is a graph which shows the relationship between the heat capacity of a receiver, and a refrigerant density. 第２のデフロスト運転時における各アクチュエータの制御パターンを示す表である。It is a table | surface which shows the control pattern of each actuator at the time of a 2nd defrost driving | operation. 給湯運転とデフロスト運転との切り替えの際の処理の流れを示すフローチャートである。It is a flowchart which shows the flow of the process in the case of switching to hot water supply operation and defrost operation. 実施の形態２に係るヒートポンプ式給湯装置のヒートポンプ部分を示す冷媒回路図である。6 is a refrigerant circuit diagram illustrating a heat pump portion of a heat pump hot water supply apparatus according to Embodiment 2. FIG.

以下、本発明の実施の形態を図面に基づいて説明する。
実施の形態１．
図１は、本発明の実施の形態１に係るヒートポンプ式給湯装置１００のヒートポンプ部分を示す冷媒回路図である。図１に基づいて、冷凍サイクル装置の１つであるヒートポンプ式給湯装置１００の冷媒回路構成及び動作について説明する。なお、ヒートポンプ式給湯装置１００の通常運転（給湯運転）時における冷媒の流れを実線矢印Ａで、ホットガス方式でのデフロスト運転時の冷媒の流れを破線矢印Ｂで、リバース方式でのデフロスト運転時の冷媒の流れを破線矢印Ｃで、それぞれ表している。また、図１を含め、以下の図面では各構成部材の大きさの関係が実際のものとは異なる場合がある。 Hereinafter, embodiments of the present invention will be described with reference to the drawings.
Embodiment 1 FIG.
FIG. 1 is a refrigerant circuit diagram showing a heat pump portion of heat pump hot water supply apparatus 100 according to Embodiment 1 of the present invention. Based on FIG. 1, the refrigerant circuit configuration and operation of a heat pump hot water supply apparatus 100, which is one of the refrigeration cycle apparatuses, will be described. The refrigerant flow during normal operation (hot water supply operation) of the heat pump hot water supply apparatus 100 is indicated by a solid line arrow A, the refrigerant flow during hot gas type defrost operation is indicated by a broken line arrow B, and during reverse mode defrost operation. The flow of the refrigerant is indicated by a broken line arrow C. Moreover, in the following drawings including FIG. 1, the relationship of the size of each component may be different from the actual one.

ヒートポンプ式給湯装置１００は、図１に示すように、冷媒回路Ａと、水回路Ｂと、を有している。冷媒回路Ａ及び水回路Ｂは、水熱交換器２で互いの冷媒や水が混ざることなく熱交換を行なうようになっている。冷媒回路Ａは、通常運転時において、圧縮機１と、四方弁９と、水熱交換器２の冷媒側と、第１膨張弁３と、レシーバー４と、第２膨張弁５と、室外熱交換器６と、冷媒−冷媒熱交換器７と、が冷媒配管（吐出配管１０、中圧管１１、低圧管１２及び吸入配管１３）で直列に接続されているとともに、圧縮機１と四方弁９との間と、第２膨張弁５と室外熱交換器６と、の間を接続したバイパス配管１４にバイパス膨張弁８を設けることで構成されている。水回路Ｂは、ポンプ２ａと、水熱交換器２の水側と、図示省略の貯湯タンクと、が水配管１６で直列に接続されて構成されている。 The heat pump hot water supply apparatus 100 has a refrigerant circuit A and a water circuit B as shown in FIG. The refrigerant circuit A and the water circuit B perform heat exchange in the water heat exchanger 2 without mixing each other's refrigerant and water. The refrigerant circuit A includes the compressor 1, the four-way valve 9, the refrigerant side of the water heat exchanger 2, the first expansion valve 3, the receiver 4, the second expansion valve 5, and the outdoor heat during normal operation. The exchanger 6 and the refrigerant-refrigerant heat exchanger 7 are connected in series by refrigerant pipes (discharge pipe 10, intermediate pressure pipe 11, low pressure pipe 12 and suction pipe 13), and the compressor 1 and the four-way valve 9 are connected. The bypass expansion valve 8 is provided in a bypass pipe 14 that connects between the second expansion valve 5 and the outdoor heat exchanger 6. The water circuit B includes a pump 2 a, a water side of the water heat exchanger 2, and a hot water storage tank (not shown) connected in series by a water pipe 16.

ヒートポンプ式給湯装置１００には、室外ファン６ａが室外熱交換器６の近傍に設けられている。また、ヒートポンプ式給湯装置１００には、制御装置２０がたとえば図示省略の室外機等に設けられている。さらに、ヒートポンプ式給湯装置１００には、吸入圧力検出器２１が吸入配管１３に、吐出圧力検出器２２が吐出配管１０に、第１温度検出器２３が吸入配管１３に、第２温度検出器２４が吐出配管１０に、第３温度検出器２５が水熱交換器２の通常運転時における液側配管に、第４温度検出器２６が室外熱交換器６の通常運転時における入口側に、第５温度検出器２７が室外熱交換器６の通常運転時における出口側に、第６温度検出器２８が室外熱交換器６の空気側に、それぞれ設けられている。 In the heat pump hot water supply apparatus 100, an outdoor fan 6 a is provided in the vicinity of the outdoor heat exchanger 6. Moreover, in the heat pump hot water supply apparatus 100, the control apparatus 20 is provided in, for example, an outdoor unit (not shown). Further, in the heat pump hot water supply apparatus 100, the suction pressure detector 21 is in the suction pipe 13, the discharge pressure detector 22 is in the discharge pipe 10, the first temperature detector 23 is in the suction pipe 13, and the second temperature detector 24. Is connected to the discharge pipe 10, the third temperature detector 25 is connected to the liquid side pipe during the normal operation of the water heat exchanger 2, and the fourth temperature detector 26 is connected to the inlet side during the normal operation of the outdoor heat exchanger 6. The fifth temperature detector 27 is provided on the outlet side of the outdoor heat exchanger 6 during normal operation, and the sixth temperature detector 28 is provided on the air side of the outdoor heat exchanger 6.

圧縮機１は、吸入配管１３を流れる冷媒を吸入し、その冷媒を圧縮して高温・高圧の状態とし、吐出配管１０に吐出するものであり、たとえば容量制御可能なインバーター圧縮機等で構成するとよい。四方弁９は、運転モード切り替えを行なう流路切替装置として機能し、給湯運転時における冷媒の流れと、冷水運転時又はリバース方式のデフロスト運転時における冷媒の流れと、を切り替えるものである。つまり、四方弁９が実線矢印Ａのように切り替えられた場合には、給湯運転が行なわれ、破線矢印Ｃのように切り替えられた場合には、冷水運転又はリバース方式のデフロスト運転が行なわれる。 The compressor 1 sucks the refrigerant flowing through the suction pipe 13, compresses the refrigerant to a high temperature / high pressure state, and discharges the refrigerant to the discharge pipe 10. For example, the compressor 1 is configured by a capacity-controllable inverter compressor or the like. Good. The four-way valve 9 functions as a flow path switching device that switches the operation mode, and switches between a refrigerant flow during hot water supply operation and a refrigerant flow during cold water operation or reverse defrost operation. That is, when the four-way valve 9 is switched as indicated by the solid arrow A, a hot water supply operation is performed, and when it is switched as indicated by the broken line arrow C, a cold water operation or a reverse defrost operation is performed.

水熱交換器２は、負荷側熱交換器であり、蒸発器や放熱器（凝縮器）として機能し、水回路Ｂを循環する水と、冷媒回路Ａを循環する冷媒との、間で熱交換を行なうものである。この水熱交換器２によって、冷媒回路Ａと水回路Ｂとは、水熱交換器２で接続されている。第１膨張弁３は、高圧状態の冷媒を減圧して中圧状態にするものであり、たとえば開度が可変に制御可能な電子式膨張弁等で構成するとよい。レシーバー４は、中圧管１１を流れる冷媒のうち冷媒液を貯留するものである。第２膨張弁５は、中圧状態の冷媒を減圧して低圧状態にするものであり、たとえば開度が可変に制御可能な電子式膨張弁等で構成するとよい。 The water heat exchanger 2 is a load-side heat exchanger that functions as an evaporator or a radiator (condenser), and heats between the water circulating in the water circuit B and the refrigerant circulating in the refrigerant circuit A. Exchange. The refrigerant circuit A and the water circuit B are connected by the water heat exchanger 2 by the water heat exchanger 2. The first expansion valve 3 is configured to depressurize the high-pressure refrigerant to an intermediate pressure state, and may be configured, for example, as an electronic expansion valve whose opening degree can be variably controlled. The receiver 4 stores refrigerant liquid among refrigerants flowing through the intermediate pressure pipe 11. The second expansion valve 5 is for depressurizing the medium-pressure refrigerant to make it into a low-pressure state. For example, the second expansion valve 5 may be composed of an electronic expansion valve whose opening degree can be variably controlled.

室外熱交換器６は、熱源側熱交換器であり、蒸発器や放熱器（凝縮器）として機能し、室外ファン６ａから供給される空気と冷媒との間で熱交換を行ない、冷媒を蒸発ガス化又は凝縮液化するものである。冷媒−冷媒熱交換器７は、レシーバー４内に設けられ、レシーバー４内に貯留されている冷媒液と圧縮機１に吸入される冷媒との間で熱交換させるものである。圧縮機１からの吐出冷媒が導通する吐出配管１０が圧縮機１の吐出側に、第１膨張弁３で減圧された冷媒が導通する中圧管１１が第１膨張弁３と第２膨張弁５との間に、第２膨張弁５で減圧された冷媒が導通する低圧管１２が第２膨張弁５と室外熱交換器６との間に、圧縮機１に吸入される冷媒が導通する吸入配管１３が圧縮機１の吸入側に、それぞれ設けられている。 The outdoor heat exchanger 6 is a heat source side heat exchanger, functions as an evaporator or a radiator (condenser), exchanges heat between the air supplied from the outdoor fan 6a and the refrigerant, and evaporates the refrigerant. It is gasified or condensed into liquid. The refrigerant-refrigerant heat exchanger 7 is provided in the receiver 4 and exchanges heat between the refrigerant liquid stored in the receiver 4 and the refrigerant sucked into the compressor 1. The discharge pipe 10 through which the refrigerant discharged from the compressor 1 conducts is connected to the discharge side of the compressor 1, and the intermediate pressure pipe 11 through which the refrigerant decompressed by the first expansion valve 3 conducts is the first expansion valve 3 and the second expansion valve 5. Between the second expansion valve 5 and the outdoor heat exchanger 6, the refrigerant sucked into the compressor 1 is conducted between the low pressure pipe 12 through which the refrigerant decompressed by the second expansion valve 5 is conducted. Pipes 13 are respectively provided on the suction side of the compressor 1.

バイパス配管１４は、圧縮機１と四方弁９との間と、第２膨張弁５と室外熱交換器６と、の間を接続し、ホットガス方式でのデフロスト運転時において圧縮機１からの吐出冷媒を室外熱交換器６に導くものである。バイパス膨張弁８は、高圧状態の冷媒を減圧して膨張させるものであり、たとえば開度が可変に制御可能な電子式膨張弁等で構成するとよい。また、ポンプ２ａは、水駆動手段として機能し、水配管１６を導通している水を吸入し、その水を加圧し、水回路Ｂ内を循環させるものであり、たとえばインバーターにより回転数が制御されるタイプのもので構成するとよい。さらに、室外ファン６ａは、室外熱交換器６に空気を供給するものである。 The bypass pipe 14 connects between the compressor 1 and the four-way valve 9, and between the second expansion valve 5 and the outdoor heat exchanger 6, and from the compressor 1 during the defrost operation in the hot gas system. The discharged refrigerant is guided to the outdoor heat exchanger 6. The bypass expansion valve 8 expands the high-pressure refrigerant by depressurizing it. For example, the bypass expansion valve 8 may be composed of an electronic expansion valve whose opening degree can be variably controlled. The pump 2a functions as a water drive means, sucks water that is conducted through the water pipe 16, pressurizes the water, and circulates the water circuit B. For example, the rotation speed is controlled by an inverter. It is good to comprise with the type of being done. Further, the outdoor fan 6 a supplies air to the outdoor heat exchanger 6.

吸入圧力検出器２１は、低圧冷媒の測定装置として圧縮機１に吸入される冷媒の吸入圧力を検出するものである。吐出圧力検出器２２は、高圧冷媒の測定装置として圧縮機１から吐出される冷媒の吐出圧力を検出するものである。第１温度検出器２３は、冷媒温度の測定装置として圧縮機１に吸入される冷媒の温度を検出するものである。第２温度検出器２４は、冷媒温度の測定装置として圧縮機１から吐出される冷媒の温度を検出するものである。第３温度検出器２５は、冷媒温度の測定装置として水熱交換器２の通常運転時における液側配管を導通する冷媒の温度を検出するものである。 The suction pressure detector 21 detects the suction pressure of the refrigerant sucked into the compressor 1 as a low-pressure refrigerant measuring device. The discharge pressure detector 22 detects the discharge pressure of the refrigerant discharged from the compressor 1 as a high-pressure refrigerant measuring device. The first temperature detector 23 detects the temperature of the refrigerant sucked into the compressor 1 as a refrigerant temperature measuring device. The 2nd temperature detector 24 detects the temperature of the refrigerant | coolant discharged from the compressor 1 as a refrigerant | coolant temperature measuring apparatus. The 3rd temperature detector 25 detects the temperature of the refrigerant | coolant which conducts | connects the liquid side piping at the time of the normal driving | operation of the water heat exchanger 2 as a refrigerant | coolant temperature measuring apparatus.

第４温度検出器２６は、冷媒温度の測定装置として室外熱交換器６の通常運転時における入口側の冷媒の温度を検出するものである。第５温度検出器２７は、冷媒温度の測定装置として室外熱交換器６の通常運転時における出口側の冷媒の温度を検出するものである。第６温度検出器２８は、空気温度の測定装置として、空気側の代表温度、たとえば吸い込み温度を検出するものである。これらの検出器で検出された測定情報は、検出信号として制御装置２０に送られるようになっている。 The 4th temperature detector 26 detects the temperature of the refrigerant | coolant of the inlet side at the time of the normal driving | operation of the outdoor heat exchanger 6 as a refrigerant | coolant temperature measuring apparatus. The 5th temperature detector 27 detects the temperature of the refrigerant | coolant of the exit side at the time of the normal driving | operation of the outdoor heat exchanger 6 as a refrigerant | coolant temperature measuring apparatus. The sixth temperature detector 28 is a device for measuring an air temperature, and detects a representative temperature on the air side, for example, a suction temperature. Measurement information detected by these detectors is sent to the control device 20 as a detection signal.

制御装置２０は、たとえばマイクロコンピューター等で構成されており、上述した各検出器からの検出信号（冷媒圧力検出値、冷媒温度検出値、及び、空気温度検出値）に基づいて圧縮機１の駆動、室外ファン６ａのファンモーターの駆動、四方弁９の切り替え、第１膨張弁３の開度、第２膨張弁５の開度、バイパス膨張弁８の開度、及び、ポンプ２ａの駆動周波数等を制御する機能を有している。また、制御装置２０は、各検出器からの検出信号から各制御値を決定する関数等が格納されたメモリ２０ａを備えている。このメモリ２０ａは、たとえばハードディスク装置（ＨＤＤ）や不揮発メモリ等で構成するとよい。 The control device 20 is composed of, for example, a microcomputer, and drives the compressor 1 based on detection signals (refrigerant pressure detection value, refrigerant temperature detection value, and air temperature detection value) from each detector described above. , Driving of the fan motor of the outdoor fan 6a, switching of the four-way valve 9, opening of the first expansion valve 3, opening of the second expansion valve 5, opening of the bypass expansion valve 8, driving frequency of the pump 2a, etc. It has a function to control. In addition, the control device 20 includes a memory 20a in which a function for determining each control value from a detection signal from each detector is stored. The memory 20a may be composed of, for example, a hard disk device (HDD) or a nonvolatile memory.

なお、図１では、冷媒−冷媒熱交換器７がレシーバー４内に設けられている場合を例に示しているが、これに限定するものではなく、たとえばレシーバー４と同じ圧力の冷媒が導通している中圧管１１と熱交換するような位置に設けてもよい。また、冷凍サイクル装置がヒートポンプ式給湯装置１００であるとして説明しているが、これに限定するものではなく、冷凍サイクル装置が空気調和装置であってもよい。空気調和装置を冷凍サイクル装置の一例とする場合には、水熱交換器２が室内熱交換器となり、ポンプ２ａが室内ファンとなる。そして、通常運転が暖房運転となり、冷水運転が冷房運転となる。 1 shows an example in which the refrigerant-refrigerant heat exchanger 7 is provided in the receiver 4. However, the present invention is not limited to this. For example, a refrigerant having the same pressure as the receiver 4 is conducted. You may provide in the position which heat-exchanges with the intermediate pressure pipe 11 currently provided. Moreover, although demonstrated that the refrigeration cycle apparatus is the heat pump type hot water supply apparatus 100, it is not limited to this, A refrigeration cycle apparatus may be an air conditioning apparatus. When the air conditioner is an example of a refrigeration cycle apparatus, the water heat exchanger 2 is an indoor heat exchanger, and the pump 2a is an indoor fan. The normal operation is the heating operation, and the cold water operation is the cooling operation.

ここから、このヒートポンプ式給湯装置１００の冷媒回路における各種運転時の冷媒の流れを、制御装置２０が実行する各構成部品（アクチュエーター）の制御についてとともに説明する。最初に、通常運転である給湯運転について説明する。ヒートポンプ式給湯装置１００が給湯運転を実行する場合、制御装置２０は、四方弁９の接続配管が実線矢印Ａのように接続されるように冷媒流路を切り替える。このような冷媒流路にしてから給湯運転が開始される。ヒートポンプ式給湯装置１００が給湯運転を開始すると、まず圧縮機１が駆動される。 From here, the flow of the refrigerant | coolant at the time of various driving | operations in the refrigerant circuit of this heat pump type hot water supply apparatus 100 is demonstrated with control of each component (actuator) which the control apparatus 20 performs. First, a hot water supply operation that is a normal operation will be described. When the heat pump hot water supply apparatus 100 executes the hot water supply operation, the control apparatus 20 switches the refrigerant flow path so that the connection pipe of the four-way valve 9 is connected as indicated by the solid line arrow A. The hot water supply operation is started after the refrigerant passage is formed. When the heat pump hot water supply apparatus 100 starts a hot water supply operation, the compressor 1 is first driven.

圧縮機１に吸入された冷媒は、圧縮機１で高温・高圧のガス状態となって吐出され、吐出配管１０を流れて、四方弁９を介し水熱交換器２に流入する。この水熱交換器２では、流入した冷媒が水を加熱しながら冷却され、中温・高圧の液冷媒となる。この冷媒は、水熱交換器２から流出し、第１膨張弁３で中圧に減圧される。そして、この中温・中圧の液冷媒は、中圧管１１を流れ、冷媒−冷媒熱交換器７で圧縮機１に吸入される冷媒と熱交換し、更に冷却されることになる。 The refrigerant sucked into the compressor 1 is discharged in a high-temperature and high-pressure gas state in the compressor 1, flows through the discharge pipe 10, and flows into the water heat exchanger 2 through the four-way valve 9. In the water heat exchanger 2, the refrigerant that has flowed in is cooled while heating water, and becomes a medium-temperature / high-pressure liquid refrigerant. This refrigerant flows out of the water heat exchanger 2 and is reduced to an intermediate pressure by the first expansion valve 3. The medium-temperature / medium-pressure liquid refrigerant flows through the intermediate-pressure pipe 11, exchanges heat with the refrigerant sucked into the compressor 1 by the refrigerant-refrigerant heat exchanger 7, and is further cooled.

冷媒−冷媒熱交換器７で冷却された中圧の液冷媒は、レシーバー４を介し、第２膨張弁５で再び減圧され、低温・低圧の冷媒となる。この低温・低圧の冷媒は、低圧管１２を流れて室外熱交換器６に流入する。室外熱交換器６に流入した冷媒は、室外ファン６ａから供給される室外空気を冷却しながら加熱され、低温・低圧のガス冷媒となる。このガス冷媒は、室外熱交換器６から流出し、四方弁９を介して冷媒−冷媒熱交換器７に流入する。冷媒−冷媒熱交換器７に流入した冷媒は、前述した中圧管１１を流れる中圧の冷媒と熱交換し加熱され、吸入配管１３を流れて圧縮機１に再度吸入される。 The medium-pressure liquid refrigerant cooled by the refrigerant-refrigerant heat exchanger 7 is decompressed again by the second expansion valve 5 via the receiver 4 and becomes a low-temperature / low-pressure refrigerant. The low-temperature and low-pressure refrigerant flows through the low-pressure pipe 12 and flows into the outdoor heat exchanger 6. The refrigerant flowing into the outdoor heat exchanger 6 is heated while cooling the outdoor air supplied from the outdoor fan 6a, and becomes a low-temperature and low-pressure gas refrigerant. This gas refrigerant flows out of the outdoor heat exchanger 6 and flows into the refrigerant-refrigerant heat exchanger 7 through the four-way valve 9. The refrigerant that has flowed into the refrigerant-refrigerant heat exchanger 7 is heated by exchanging heat with the medium-pressure refrigerant that flows through the intermediate-pressure pipe 11 described above, flows through the suction pipe 13, and is sucked into the compressor 1 again.

図２は、給湯運転時における各アクチュエータの制御パターンを示す表である。図２に基づいて、制御装置２０が実行する給湯運転時における各アクチュエータの制御について説明する。この表には、制御装置２０によって実行される圧縮機１の周波数［Ｈｚ］、第１膨張弁３の開度、第２膨張弁５の開度、バイパス膨張弁８の開度、及び、室外ファン６ａの回転速度の制御パターンを図示している。 FIG. 2 is a table showing a control pattern of each actuator during a hot water supply operation. Based on FIG. 2, the control of each actuator during the hot water supply operation executed by the control device 20 will be described. In this table, the frequency [Hz] of the compressor 1 executed by the control device 20, the opening degree of the first expansion valve 3, the opening degree of the second expansion valve 5, the opening degree of the bypass expansion valve 8, and the outdoor The control pattern of the rotational speed of the fan 6a is illustrated.

表に示すように、給湯運転時において制御装置２０は、圧縮機１を水側（水回路Ｂ）の負荷に応じて周波数制御し、第１膨張弁３を水熱交換器２の出口における冷媒の過冷却度（ＳＣ）に応じてＳＣ制御し、第２膨張弁５を圧縮機１に吸入される冷媒の過熱度（ＳＨ）又は圧縮機１を吐出した冷媒の過熱度（ＳＨ）に応じてＳＨ制御し、バイパス膨張弁８を閉止するように制御し、室外ファン６ａを室外熱交換器６における冷媒の蒸発温度、すなわち冷媒の吸入圧力に応じて制御している。 As shown in the table, during the hot water supply operation, the control device 20 controls the frequency of the compressor 1 according to the load on the water side (water circuit B), and the first expansion valve 3 is a refrigerant at the outlet of the water heat exchanger 2. The second expansion valve 5 is controlled according to the degree of supercooling (SC), and the second expansion valve 5 depends on the degree of superheat (SH) of the refrigerant sucked into the compressor 1 or the degree of superheat (SH) of the refrigerant discharged from the compressor 1. The SH is controlled to close the bypass expansion valve 8, and the outdoor fan 6a is controlled according to the refrigerant evaporation temperature in the outdoor heat exchanger 6, that is, the refrigerant suction pressure.

なお、水熱交換器２の出口における冷媒の過冷却度ＳＣは、吐出圧力検出器２２で検出される冷媒の圧力値から求められる冷媒の高圧側の飽和温度と、第３温度検出器２５で検出される冷媒温度と、の差で算出される。また、圧縮機１に吸入される冷媒の過熱度ＳＨは、第１温度検出器２３で検出される冷媒温度と、吸入圧力検出器２１で検出される圧力値から求められる冷媒の低圧側の飽和温度と、の差から算出される。さらに、圧縮機１から吐出される冷媒の過熱度ＳＨは、第２温度検出器２４で検出される冷媒温度と、吐出圧力検出器２２で検出される圧力値から求められる高圧側の飽和温度と、の差から算出される。 The supercooling degree SC of the refrigerant at the outlet of the water heat exchanger 2 is determined by the saturation temperature on the high pressure side of the refrigerant obtained from the pressure value of the refrigerant detected by the discharge pressure detector 22 and the third temperature detector 25. It is calculated by the difference between the detected refrigerant temperature. Further, the superheat degree SH of the refrigerant sucked into the compressor 1 is determined by saturation of the refrigerant on the low pressure side obtained from the refrigerant temperature detected by the first temperature detector 23 and the pressure value detected by the suction pressure detector 21. It is calculated from the difference between the temperature. Further, the superheat degree SH of the refrigerant discharged from the compressor 1 is determined by the refrigerant temperature detected by the second temperature detector 24 and the saturation temperature on the high pressure side obtained from the pressure value detected by the discharge pressure detector 22. It is calculated from the difference between.

次に、室外熱交換器６に着霜して冷媒の蒸発温度が低下して暖房性能が低くなってきたときのデフロスト運転について説明する。デフロスト運転には２パターンあるため、それぞれの運転パターンに分けて説明する。第１のデフロスト運転は、着霜量が少ない場合や外気温度が所定温度より高い場合、つまり除霜に必要なエネルギーが少ない場合に実行するパターンである（破線矢印Ｂ）。この場合、制御装置２０は、第１膨張弁３及び第２膨張弁５を閉止し、バイパス膨張弁８の開度を制御して、主に圧縮機入力によりデフロスト運転を行なうようになっている。ヒートポンプ式給湯装置１００が第１のデフロスト運転を開始すると、まず圧縮機１が駆動される。 Next, defrosting operation when the outdoor heat exchanger 6 is frosted and the evaporation temperature of the refrigerant is lowered to lower the heating performance will be described. Since there are two patterns in defrost operation, each operation pattern will be described separately. The first defrost operation is a pattern executed when the amount of frost formation is small or when the outside air temperature is higher than a predetermined temperature, that is, when the energy required for defrosting is small (broken arrow B). In this case, the control device 20 closes the first expansion valve 3 and the second expansion valve 5, controls the opening degree of the bypass expansion valve 8, and performs the defrost operation mainly by the compressor input. . When the heat pump hot water supply apparatus 100 starts the first defrost operation, the compressor 1 is first driven.

圧縮機１に吸入された冷媒は、圧縮機１で高温・高圧のガス状態となって吐出され、吐出配管１０及びバイパス配管１４を流れて、バイパス膨張弁８で減圧され、中温・低圧のガス冷媒となる。この中温・低圧のガス冷媒は、低圧管１２を流れて、室外熱交換器６に流入し、室外熱交換器６の表面に付着した霜を溶かしながら冷却される。この冷媒は、室外熱交換器６から流出し、四方弁９を介して冷媒−冷媒熱交換器７に流入する。冷媒−冷媒熱交換器７に流入した冷媒は、中圧管１１を流れる中圧の冷媒と熱交換し加熱され、吸入配管１３を流れて圧縮機１に再度吸入される。圧縮機１へ吸入される冷媒は、冷媒−冷媒熱交換器７により加熱されるようになっているため、圧縮機１への液バックを防ぐことができる。 The refrigerant sucked into the compressor 1 is discharged in a high-temperature / high-pressure gas state in the compressor 1, flows through the discharge pipe 10 and the bypass pipe 14, is decompressed by the bypass expansion valve 8, and is medium-temperature / low-pressure gas. Becomes a refrigerant. The medium temperature / low pressure gas refrigerant flows through the low pressure pipe 12 and flows into the outdoor heat exchanger 6, and is cooled while melting frost adhering to the surface of the outdoor heat exchanger 6. This refrigerant flows out of the outdoor heat exchanger 6 and flows into the refrigerant-refrigerant heat exchanger 7 through the four-way valve 9. The refrigerant that has flowed into the refrigerant-refrigerant heat exchanger 7 is heated by exchanging heat with the medium-pressure refrigerant that flows through the intermediate-pressure pipe 11, flows through the suction pipe 13, and is sucked into the compressor 1 again. Since the refrigerant sucked into the compressor 1 is heated by the refrigerant-refrigerant heat exchanger 7, liquid back to the compressor 1 can be prevented.

図３は、第１のデフロスト運転時における各アクチュエータの制御パターンを示す表である。図３に基づいて、制御装置２０が実行する第１のデフロスト運転時における各アクチュエータの制御について説明する。この表には、制御装置２０によって実行される圧縮機１の周波数［Ｈｚ］、第１膨張弁３の開度、第２膨張弁５の開度、バイパス膨張弁８の開度、及び、室外ファン６ａの回転速度の制御パターンを図示している。 FIG. 3 is a table showing a control pattern of each actuator during the first defrost operation. Based on FIG. 3, the control of each actuator during the first defrost operation performed by the control device 20 will be described. In this table, the frequency [Hz] of the compressor 1 executed by the control device 20, the opening degree of the first expansion valve 3, the opening degree of the second expansion valve 5, the opening degree of the bypass expansion valve 8, and the outdoor The control pattern of the rotational speed of the fan 6a is illustrated.

表に示すように、第１のデフロスト運転時において制御装置２０は、圧縮機１の周波数を一定速（たとえば、全速）に制御し、第１膨張弁３及び第２膨張弁５を閉止するように制御し、バイパス膨張弁８を圧縮機１に吸入される冷媒の過熱度（ＳＨ）又は圧縮機１を吐出した冷媒の過熱度（ＳＨ）に応じてＳＨ制御し、室外ファン６ａを停止するように制御している。なお、圧縮機１に吸入される冷媒の過熱度ＳＨは、吸入圧力検出器２１及び第１温度検出器２３の検出値から、圧縮機１から吐出される冷媒の過熱度ＳＨは、吐出圧力検出器２２及び第２温度検出器２４の検出値から算出される。 As shown in the table, during the first defrost operation, the control device 20 controls the frequency of the compressor 1 to a constant speed (for example, full speed) so as to close the first expansion valve 3 and the second expansion valve 5. And the bypass expansion valve 8 is SH controlled according to the degree of superheat (SH) of the refrigerant sucked into the compressor 1 or the degree of superheat (SH) of the refrigerant discharged from the compressor 1, and the outdoor fan 6a is stopped. So that it is controlled. The superheat degree SH of the refrigerant sucked into the compressor 1 is detected from the detection values of the suction pressure detector 21 and the first temperature detector 23, and the superheat degree SH of the refrigerant discharged from the compressor 1 is detected as a discharge pressure. It is calculated from the detected values of the device 22 and the second temperature detector 24.

ただし、水熱交換器２等の高圧側の要素機器に冷媒が溜まりすぎて吐出圧力が上昇し、高圧側圧力が所定の圧力値より上昇した場合には、一時的に、第１膨張弁３を開いて中間圧のレシーバー４に冷媒を移動させて高圧側の圧力、すなわち吐出圧力を下げるように制御するとよい。このように第１膨張弁３で高圧側回路の冷媒量を調整することで、水熱交換器２に流入する冷媒により水熱交換器２内の冷媒密度が変化し、吐出圧力が変化した場合にも、適正な圧力に制御でき、安定したデフロスト運転を実現できる。 However, when the refrigerant accumulates excessively in the high-pressure side element device such as the water heat exchanger 2 and the discharge pressure rises and the high-pressure side pressure rises above a predetermined pressure value, the first expansion valve 3 is temporarily stored. And the refrigerant is moved to the intermediate pressure receiver 4 to control the pressure on the high pressure side, that is, the discharge pressure to be lowered. When the refrigerant density in the water heat exchanger 2 is changed by the refrigerant flowing into the water heat exchanger 2 and the discharge pressure is changed by adjusting the amount of refrigerant in the high pressure side circuit with the first expansion valve 3 in this way. In addition, it can be controlled to an appropriate pressure, and a stable defrost operation can be realized.

また、室外熱交換器６で霜と熱交換することにより冷媒が液化してガスの密度が小さくなり、吸入圧力が低下する場合には、一時的に、第２膨張弁５を開いて中間圧のレシーバー４の冷媒を移動させて低圧側の圧力、すなわち吸入圧力を上げるように制御するとよい。このように第１膨張弁３で低圧側回路の冷媒量を調整することで、室外熱交換器６で冷媒が凝縮することで吸入圧力が低下した場合に、レシーバー４から冷媒の供給を行ない、吸入圧力を維持し、圧縮機入力を確保することができ、安定したデフロスト運転を実現できる。 Further, when the refrigerant is liquefied by the heat exchange with frost in the outdoor heat exchanger 6 to reduce the density of the gas and the suction pressure is reduced, the second expansion valve 5 is temporarily opened and the intermediate pressure is reduced. The refrigerant of the receiver 4 may be moved so as to increase the pressure on the low pressure side, that is, the suction pressure. In this way, by adjusting the amount of refrigerant in the low-pressure side circuit with the first expansion valve 3, when the intake pressure is reduced due to condensation of the refrigerant in the outdoor heat exchanger 6, the refrigerant is supplied from the receiver 4, The suction pressure can be maintained, the compressor input can be secured, and stable defrosting operation can be realized.

第１のデフロスト運転中、基本的にレシーバー４の入口の第１膨張弁３、及び、出口の第２膨張弁５が閉止されている。この状態では、中圧管１１を流れる冷媒は、冷媒−冷媒熱交換器７により圧縮機１に吸入される低温・低圧の冷媒と熱交換するため、中間圧ライン（中圧管１１）、特にレシーバー４内に冷熱が溜まることになっている。そこで、第１のデフロスト運転中、中間圧ラインのレシーバー４内に溜められる冷熱の量について検討する。 During the first defrosting operation, the first expansion valve 3 at the inlet of the receiver 4 and the second expansion valve 5 at the outlet are basically closed. In this state, since the refrigerant flowing through the intermediate pressure pipe 11 exchanges heat with the low-temperature and low-pressure refrigerant sucked into the compressor 1 by the refrigerant-refrigerant heat exchanger 7, the intermediate pressure line (intermediate pressure pipe 11), particularly the receiver 4. Cold heat is to accumulate inside. Therefore, the amount of cold stored in the receiver 4 of the intermediate pressure line during the first defrost operation will be examined.

図４は、Ｒ４１０Ａ冷媒の状態を示すＰ−ｈ線図である。図４に基づいて、ヒートポンプ式給湯装置１００の運転に応じたＲ４１０Ａ冷媒の状態について説明する。この図４では、縦軸が圧力［ＭＰａ］を、横軸がエンタルピ［ｋＪ／ｋｇ］を、それぞれ表している。また、図４には、等密度線（線（ア）〜線（ウ））、及び、等温線（線（カ）〜線（コ））を併せて図示している。線（ア）が１０００ｋｇ／ｍ³の等密度線を、線（イ）が６００ｋｇ／ｍ³の等密度線を、線（ウ）が３００ｋｇ／ｍ³の等密度線を、それぞれ示している。線（カ）が４５℃の等温線を、線（キ）が３０℃の等温線を、線（ク）が１５℃の等温線を、線（コ）が０℃の等温線を、それぞれ示している。 FIG. 4 is a Ph diagram illustrating the state of the R410A refrigerant. Based on FIG. 4, the state of the R410A refrigerant according to the operation of the heat pump hot water supply apparatus 100 will be described. In FIG. 4, the vertical axis represents pressure [MPa] and the horizontal axis represents enthalpy [kJ / kg]. FIG. 4 also shows isodensity lines (line (A) to line (C)) and isothermal lines (line (F) to line (C)). Line (a) shows an isodensity line of 1000 kg / m ³ , line (a) shows an isodensity line of 600 kg / m ³ , and line (c) shows an isodensity line of 300 kg / m ³ . Line (f) shows an isotherm at 45 ° C, line (ki) shows an isotherm at 30 ° C, line (ku) shows an isotherm at 15 ° C, and line (ko) shows an isotherm at 0 ° C. ing.

第１のデフロスト運転中においては、第１膨張弁３及び第２膨張弁５は閉止しているため、中圧管１１を流れる冷媒の密度は変化しない。そのため、中圧管１１を流れる冷媒は、冷媒−冷媒熱交換器７により圧縮機１に吸入される冷媒と熱交換し、冷却されると図中の（１）→（２）のように線（ウ）の等密度線上で変化することになる。この間にレシーバー４内に溜められる熱量、つまりレシーバー４の熱容量Ｑは、以下の式で表される。
Ｑ＝ρＶΔｈ During the first defrost operation, since the first expansion valve 3 and the second expansion valve 5 are closed, the density of the refrigerant flowing through the intermediate pressure pipe 11 does not change. Therefore, the refrigerant flowing through the intermediate pressure pipe 11 exchanges heat with the refrigerant sucked into the compressor 1 by the refrigerant-refrigerant heat exchanger 7, and when cooled, the line (1) → (2) in the figure ( It will change on the isodensity line of c). The amount of heat stored in the receiver 4 during this period, that is, the heat capacity Q of the receiver 4 is expressed by the following equation.
Q = ρVΔh

ここで、ρはレシーバー４内の密度［ｋｇ／ｍ³］を、Ｖはレシーバー４の容積［ｍ³］を、Δｈはエンタルピ変化量［ｋＪ／ｋｇ］を、それぞれ示している。たとえば、容積が２．３Ｌのレシーバー４を用い、通常運転ではレシーバー４内の温度が２５℃で、冷媒密度ρが８００［ｋｇ／ｍ³］であった場合、第１のデフロスト運転によりレシーバー４内の温度が０℃まで下がると、Ｑ＝７５．６［ｋＪ］となる。 Here, ρ represents the density [kg / m ³ ] in the receiver 4, V represents the volume [m ³ ] of the receiver 4, and Δh represents the enthalpy change [kJ / kg]. For example, when the receiver 4 having a volume of 2.3 L is used, and the temperature in the receiver 4 is 25 ° C. and the refrigerant density ρ is 800 [kg / m ³ ] in normal operation, the receiver 4 is subjected to the first defrost operation. When the temperature inside falls to 0 ° C., Q = 75.6 [kJ].

図５は、レシーバー４の熱容量と冷媒密度との関係を示すグラフである。図５に基づいて、レシーバー４内の温度が２５℃から０℃にまで下がった場合のレシーバー４内における冷媒密度に対するレシーバー４の熱容量Ｑについて説明する。この図５では、縦軸がレシーバー４の熱容量［ｋｊ］を、横軸が冷媒密度［ｋｇ／ｍ³］を、それぞれ表している。 FIG. 5 is a graph showing the relationship between the heat capacity of the receiver 4 and the refrigerant density. Based on FIG. 5, the heat capacity Q of the receiver 4 with respect to the refrigerant density in the receiver 4 when the temperature in the receiver 4 falls from 25 ° C. to 0 ° C. will be described. In FIG. 5, the vertical axis represents the heat capacity [kj] of the receiver 4 and the horizontal axis represents the refrigerant density [kg / m ³ ].

第１のデフロスト運転において２．５ｋｇの霜を融解しようとした場合、必要な熱量は、約８５０ｋＪである。このヒートポンプ式給湯装置１００の冷媒回路Ａの封入冷媒量を、ヒートポンプ式給湯装置が実行する運転のうちで最も多く冷媒を必要とする冷房運転に必要な冷媒量に合わせていれば、給湯運転では冷媒量が過剰となり、レシーバー４内に液として溜まることになる。レシーバー４中がほぼ液の状態となっていれば、この熱容量により、除霜に必要なエネルギー量の約１０％を一時的に溜めることができる。 When trying to melt 2.5 kg of frost in the first defrost operation, the required amount of heat is about 850 kJ. If the amount of refrigerant enclosed in the refrigerant circuit A of the heat pump hot water supply apparatus 100 is matched with the amount of refrigerant necessary for the cooling operation that requires the most refrigerant among the operations performed by the heat pump hot water supply apparatus, The amount of refrigerant becomes excessive and accumulates in the receiver 4 as a liquid. If the receiver 4 is almost in a liquid state, about 10% of the amount of energy required for defrosting can be temporarily stored by this heat capacity.

第１のデフロスト運転は、圧縮機入力のエネルギーにより行なわれるが、ヒートポンプ式給湯装置１００では、レシーバー４内に閉じ込められた冷媒が、圧縮機１に吸入される冷媒と熱交換して冷却されるため、冷熱をレシーバー４内に溜めることができる。つまり、第１のデフロスト運転に必要な圧縮機入力を減らすことができ、デフロストにかかる時間を短縮させられる。デフロストにかかる時間を短縮させることで、通常運転の時間を相対的に長くでき、平均能力および平均ＣＯＰを向上させることができる。第１のデフロスト運転中にレシーバー４内に溜められた冷熱は、通常運転復帰後に室外熱交換器６に移動し、室外の空気と熱交換することにより処理される。 The first defrost operation is performed by energy input from the compressor. In the heat pump hot water supply apparatus 100, the refrigerant confined in the receiver 4 is cooled by exchanging heat with the refrigerant sucked into the compressor 1. Therefore, cold heat can be stored in the receiver 4. That is, the compressor input required for the first defrosting operation can be reduced, and the time required for the defrosting can be shortened. By shortening the time required for defrosting, the normal operation time can be relatively increased, and the average capacity and the average COP can be improved. The cold heat accumulated in the receiver 4 during the first defrost operation moves to the outdoor heat exchanger 6 after returning to the normal operation, and is processed by exchanging heat with outdoor air.

第２のデフロスト運転は、着霜量が多い場合や外気温度が低い場合、つまり除霜に必要なエネルギーが多い場合に実行するパターンである（破線矢印Ｃ）。この場合、制御装置２０は、四方弁９の接続配管が破線矢印Ｃのように接続されるように冷媒流路を切り替え、除霜のために圧縮機入力と同時に、配管の熱容量、水熱交換器２における水の熱容量を利用することによりデフロスト運転を行なうようになっている。このとき、制御装置２０は、冷媒回路Ａ内の冷媒流量を増加させるために第１膨張弁３及び第２膨張弁５を全開にしておく。ヒートポンプ式給湯装置１００が第２のデフロスト運転を開始すると、まず圧縮機１が駆動される。 The second defrost operation is a pattern that is executed when the amount of frost formation is large or when the outside air temperature is low, that is, when the energy required for defrosting is large (dashed arrow C). In this case, the control device 20 switches the refrigerant flow path so that the connection pipe of the four-way valve 9 is connected as indicated by the broken line arrow C, and simultaneously with the compressor input for defrosting, the heat capacity of the pipe and the water heat exchange The defrosting operation is performed by utilizing the heat capacity of water in the vessel 2. At this time, the control device 20 fully opens the first expansion valve 3 and the second expansion valve 5 in order to increase the refrigerant flow rate in the refrigerant circuit A. When the heat pump hot water supply apparatus 100 starts the second defrost operation, the compressor 1 is first driven.

圧縮機１に吸入された冷媒は、圧縮機１で高温・高圧のガス状態となって吐出され、吐出配管１０を流れて、四方弁９を介して室外熱交換器６に流入する。室外熱交換器６に流入した冷媒は、室外熱交換器６の表面に付着した霜を溶かしながら冷却され、中温・高圧の液冷媒となる。この中温・高圧の冷媒は、室外熱交換器６から流出し、第２膨張弁５及び第１膨張弁３で減圧され、低圧・低温の液冷媒となる。この低圧・低温の液冷媒は、水熱交換器２に流入し、水を冷却しながら加熱され、低温・低圧のガス冷媒となる。このガス冷媒は、四方弁９を介し、吸入配管１３を流れて圧縮機１へ再度吸入される。 The refrigerant sucked into the compressor 1 is discharged in a high-temperature and high-pressure gas state in the compressor 1, flows through the discharge pipe 10, and flows into the outdoor heat exchanger 6 through the four-way valve 9. The refrigerant flowing into the outdoor heat exchanger 6 is cooled while melting frost adhering to the surface of the outdoor heat exchanger 6, and becomes a medium-temperature / high-pressure liquid refrigerant. This medium-temperature / high-pressure refrigerant flows out of the outdoor heat exchanger 6, is decompressed by the second expansion valve 5 and the first expansion valve 3, and becomes a low-pressure / low-temperature liquid refrigerant. The low-pressure / low-temperature liquid refrigerant flows into the water heat exchanger 2 and is heated while cooling the water to become a low-temperature / low-pressure gas refrigerant. The gas refrigerant flows through the suction pipe 13 through the four-way valve 9 and is sucked into the compressor 1 again.

図６は、第２のデフロスト運転時における各アクチュエータの制御パターンを示す表である。図６に基づいて、制御装置２０が実行する第２のデフロスト運転時における各アクチュエータの制御について説明する。この表には、制御装置２０によって実行される圧縮機１の周波数［Ｈｚ］、第１膨張弁３の開度、第２膨張弁５の開度、バイパス膨張弁８の開度、及び、室外ファン６ａの回転速度の制御パターンを図示している。表に示すように、第２のデフロスト運転時において制御装置２０は、圧縮機１の周波数を一定速（たとえば、全速）に制御し、第１膨張弁３及び第２膨張弁５を全開するように制御し、バイパス膨張弁８を閉止し、室外ファン６ａを停止するように制御している。 FIG. 6 is a table showing a control pattern of each actuator during the second defrost operation. Based on FIG. 6, the control of each actuator during the second defrost operation performed by the control device 20 will be described. In this table, the frequency [Hz] of the compressor 1 executed by the control device 20, the opening degree of the first expansion valve 3, the opening degree of the second expansion valve 5, the opening degree of the bypass expansion valve 8, and the outdoor The control pattern of the rotational speed of the fan 6a is illustrated. As shown in the table, during the second defrost operation, the control device 20 controls the frequency of the compressor 1 to a constant speed (for example, full speed) so that the first expansion valve 3 and the second expansion valve 5 are fully opened. The bypass expansion valve 8 is closed and the outdoor fan 6a is stopped.

続いて、給湯運転とデフロスト運転との切り替えについて説明する。図７は、給湯運転とデフロスト運転との切り替えの際の処理の流れを示すフローチャートである。図７に示すフローチャートを参照しつつ、給湯運転とデフロスト運転との切り替えの際の処理の流れについて説明する。なお、図７には、第１のデフロスト運転をホットガスバイパス方式デフロスト運転と称して、第２のデフロスト運転をリバース方式デフロスト運転と称して、図示している。 Next, switching between the hot water supply operation and the defrost operation will be described. FIG. 7 is a flowchart showing a process flow when switching between the hot water supply operation and the defrost operation. With reference to the flowchart shown in FIG. 7, the flow of processing when switching between the hot water supply operation and the defrost operation will be described. In FIG. 7, the first defrost operation is referred to as a hot gas bypass type defrost operation, and the second defrost operation is referred to as a reverse type defrost operation.

ヒートポンプ式給湯装置１００が給湯運転を開始する（ステップＳ１０１）。そうすると、制御装置２０は、デフロスト運転を実行するかどうかを判断する（ステップＳ１０２）。デフロスト運転を実行するかどうかの判断は、室外熱交換器６の蒸発温度、つまり第４温度検出器２６が検出した温度により行なう。通常、室外熱交換器６内を流れる冷媒の蒸発温度は、外気との熱交換を行うために第６温度検出器２８の温度よりも５℃程度低い。しかしながら、室外熱交換器６の表面に着霜して伝熱性能が下がると、外気温度と蒸発温度との差を大きくして熱交換量を維持しようとする。そこで、制御装置２０は、たとえば蒸発温度が外気温度から１０℃以上低い場合にデフロスト運転を実行すると判断する（ステップＳ１０２；Ｙｅｓ）。 The heat pump hot water supply apparatus 100 starts a hot water supply operation (step S101). Then, control device 20 determines whether or not to execute the defrost operation (step S102). Whether to perform the defrost operation is determined based on the evaporation temperature of the outdoor heat exchanger 6, that is, the temperature detected by the fourth temperature detector 26. Usually, the evaporation temperature of the refrigerant flowing in the outdoor heat exchanger 6 is about 5 ° C. lower than the temperature of the sixth temperature detector 28 in order to exchange heat with the outside air. However, when the heat transfer performance is reduced due to frost formation on the surface of the outdoor heat exchanger 6, the difference between the outside air temperature and the evaporation temperature is increased to maintain the heat exchange amount. Therefore, for example, the control device 20 determines that the defrost operation is performed when the evaporation temperature is 10 ° C. or more lower than the outside air temperature (step S102; Yes).

続いて、除霜負荷の状況により、制御装置２０は、ホットガスバイパス方式デフロスト運転（ステップＳ１０３）、あるいは、リバース方式のデフロスト運転（ステップＳ１０５）を実行する。除霜負荷の判断としては、着霜センサ（図示省略）による着霜量の監視や、第６温度検出器２８による外気温度に閾値を設け、デフロスト運転のパターンを変更すればよい。次に、制御装置２０は、デフロスト運転が終了したかどうかを判断する（ステップＳ１０４、ステップＳ１０６）。 Subsequently, the control device 20 executes a hot gas bypass type defrost operation (step S103) or a reverse type defrost operation (step S105) depending on the state of the defrost load. The determination of the defrost load may be performed by monitoring the amount of frost formed by a frost sensor (not shown) or by setting a threshold value for the outside temperature by the sixth temperature detector 28 and changing the defrost operation pattern. Next, the control device 20 determines whether or not the defrost operation has ended (steps S104 and S106).

ホットガスバイパス方式のデフロスト運転を行っている場合（ステップＳ１０３）、制御装置２０は、たとえば室外熱交換器６の圧縮機１側の配管に設けられた第５温度検出器２７の温度が０℃を超えればデフロスト完了と判断して（ステップＳ１０４；Ｙｅｓ）、通常運転を再開する（ステップＳ１０７）。一方、リバース方式のデフロスト運転を行っている場合（ステップＳ１０５）、制御装置２０は、たとえば室外熱交換器６のレシーバー４側の配管に設けられた第４温度検出器２６の温度が０℃を超えればデフロスト完了と判断して（ステップＳ１０６；Ｙｅｓ）、通常運転を再開する。 When the hot gas bypass type defrost operation is performed (step S103), the control device 20 has a temperature of the fifth temperature detector 27 provided in the pipe on the compressor 1 side of the outdoor heat exchanger 6, for example, 0 ° C. Is exceeded, it is determined that the defrost is completed (step S104; Yes), and normal operation is resumed (step S107). On the other hand, when the reverse type defrost operation is performed (step S105), the control device 20 sets the temperature of the fourth temperature detector 26 provided in the pipe on the receiver 4 side of the outdoor heat exchanger 6 to 0 ° C., for example. If it exceeds, it is determined that the defrost is completed (step S106; Yes), and normal operation is resumed.

以上のように、ヒートポンプ式給湯装置１００では、給湯運転（通常運転）とデフロスト運転とを繰り返し、給湯が行なわれる。給湯運転とホットガスバイパス方式のデフロスト運転とを繰り返す場合、デフロスト運転でレシーバー４に溜められた（閉じ込められた）冷熱は、給湯運転復帰後にレシーバー４から室外熱交換器６に移動し、処理される。このデフロスト運転では、第１膨張弁３及び第２膨張弁５が閉止しているため、凝縮器（水熱交換器２）、レシーバー４、及び、室外熱交換器６それぞれの冷媒分布が給湯運転から変化しない。 As described above, in the heat pump hot water supply apparatus 100, hot water supply is performed by repeating the hot water supply operation (normal operation) and the defrost operation. When the hot water supply operation and the hot gas bypass type defrost operation are repeated, the cold heat stored (confined) in the receiver 4 in the defrost operation is transferred from the receiver 4 to the outdoor heat exchanger 6 and processed after the hot water supply operation is restored. The In this defrost operation, since the first expansion valve 3 and the second expansion valve 5 are closed, the refrigerant distributions of the condenser (water heat exchanger 2), the receiver 4 and the outdoor heat exchanger 6 are the hot water supply operation. Does not change.

したがって、ヒートポンプ式給湯装置１００、及び、このヒートポンプ式給湯装置１００が実行する制御方法では、第１のデフロスト運転方法により冷凍サイクル内における通常運転時の冷媒分布とデフロスト運転時の冷媒分布との変化幅を低減することができる。このとき、デフロスト中に発生した冷熱はレシーバー４に溜められている。この冷熱は冷媒回路から独立しており、水熱交換器２の能力の立ち上がりに影響を及ぼさない。これらのことから、通常運転への復帰後の水熱交換器２の能力の立ち上がりが早くなり、性能低下を抑制することができる。よって、平均能力及び平均ＣＯＰを大幅に向上させることが可能になるとともに、省エネルギー化に大きく寄与することになる。 Therefore, in the heat pump hot water supply apparatus 100 and the control method executed by the heat pump hot water supply apparatus 100, the first defrost operation method changes the refrigerant distribution during normal operation and the refrigerant distribution during defrost operation in the refrigeration cycle. The width can be reduced. At this time, the cold generated in the defrost is stored in the receiver 4. This cold heat is independent of the refrigerant circuit and does not affect the rise of the capacity of the water heat exchanger 2. From these things, the start-up of the capacity of the water heat exchanger 2 after returning to normal operation is quickened, and performance degradation can be suppressed. Therefore, it is possible to greatly improve the average capacity and the average COP, and greatly contribute to energy saving.

また、第２のデフロスト運転方法により、圧縮機入力と同時に、配管の熱容量、水熱交換器２における水の熱容量を利用してデフロスト運転を行なうようになっている。第２のデフロスト運転方法は第１のデフロスト運転方法よりも水などの熱容量分だけ除霜能力が大きく、デフロストに要する時間が短くなる。着霜量が多い場合や外気温度が低く、除霜に必要なエネルギーが多い場合には、通常運転への復帰時間が短くなる効果が、冷媒分布の変化幅を低減する効果よりも大きくなる。以上のように、圧縮機１の吐出側に四方弁９を設け、外気温度又は室外熱交換器６の着霜量に応じて四方弁９を制御することでデフロスト運転パターンを変更することにより、平均能力、平均ＣＯＰを向上させることができる。 Further, by the second defrost operation method, the defrost operation is performed using the heat capacity of the pipe and the heat capacity of water in the water heat exchanger 2 simultaneously with the input of the compressor. The second defrost operation method has a larger defrosting capacity by a heat capacity such as water than the first defrost operation method, and the time required for defrosting is shortened. When the amount of frost formation is large, or when the outside air temperature is low and the energy required for defrosting is large, the effect of shortening the return time to the normal operation becomes larger than the effect of reducing the change width of the refrigerant distribution. As described above, by providing the four-way valve 9 on the discharge side of the compressor 1 and changing the defrost operation pattern by controlling the four-way valve 9 according to the outside air temperature or the frost formation amount of the outdoor heat exchanger 6, Average capacity and average COP can be improved.

実施の形態２．
図８は、本発明の実施の形態２に係るヒートポンプ式給湯装置１００ａのヒートポンプ部分を示す冷媒回路図である。図８に基づいて、冷凍サイクル装置の１つであるヒートポンプ式給湯装置１００ａの冷媒回路構成及び動作について説明する。なお、ヒートポンプ式給湯装置１００ａの通常運転（給湯運転）時における冷媒の流れを実線矢印Ａで、ホットガス方式でのデフロスト運転時の冷媒の流れを破線矢印Ｂで、リバース方式でのデフロスト運転時の冷媒の流れを破線矢印Ｃで、それぞれ表している。なお、この実施の形態２では、実施の形態１と同一部分には同一符号を付し、実施の形態１との相違点を中心に説明するものとする。 Embodiment 2. FIG.
FIG. 8 is a refrigerant circuit diagram showing a heat pump portion of heat pump hot water supply apparatus 100a according to Embodiment 2 of the present invention. Based on FIG. 8, the refrigerant circuit structure and operation | movement of the heat pump type hot-water supply apparatus 100a which is one of the refrigerating cycle apparatuses are demonstrated. Note that the refrigerant flow during normal operation (hot water supply operation) of the heat pump hot water supply apparatus 100a is indicated by a solid arrow A, the refrigerant flow during hot gas defrost operation is indicated by a broken line arrow B, and during defrost operation using a reverse method. The flow of the refrigerant is indicated by a broken line arrow C. In the second embodiment, the same parts as those in the first embodiment are denoted by the same reference numerals, and differences from the first embodiment will be mainly described.

実施の形態２に係るヒートポンプ式給湯装置１００ａは、熱源側熱交換器である室外熱交換器が第１室外熱交換器６１と第２室外熱交換器６２に分割されて構成されている点で、実施の形態１に係るヒートポンプ式給湯装置１００と相違している。第２室外熱交換器６２は、第１室外熱交換器６１の鉛直方向上側に設置されている。第１室外熱交換器６１と第２室外熱交換器６２とは配管１５で接続されている。この配管１５には、絞り手段としての電磁弁３１が設けられている。また、配管１５と接続しているヘッダと第２室外熱交換器６２とを接続している伝熱管には、絞り手段としてのキャピラリー３０が設けられている。なお、その他の構成については、ヒートポンプ式給湯装置１００と同様に構成されている。 The heat pump hot water supply apparatus 100a according to the second embodiment is configured such that an outdoor heat exchanger that is a heat source side heat exchanger is divided into a first outdoor heat exchanger 61 and a second outdoor heat exchanger 62. This is different from the heat pump hot water supply apparatus 100 according to the first embodiment. The second outdoor heat exchanger 62 is installed on the upper side in the vertical direction of the first outdoor heat exchanger 61. The first outdoor heat exchanger 61 and the second outdoor heat exchanger 62 are connected by a pipe 15. This pipe 15 is provided with an electromagnetic valve 31 as a throttle means. In addition, the heat transfer pipe connecting the header connected to the pipe 15 and the second outdoor heat exchanger 62 is provided with a capillary 30 as a throttle means. In addition, about another structure, it is comprised similarly to the heat pump type hot-water supply apparatus 100. FIG.

実施の形態２に係るヒートポンプ式給湯装置１００において給湯運転を行なう場合、制御装置２０は、電磁弁３１を開くように制御する。そうすると、冷媒は、実線矢印Ａのように流れる。つまり、第２膨張弁５を通過した冷媒は、低圧管１２を流れて第１熱源側熱交換器である第１室外熱交換器６１に流入し、それから配管１５を流れて電磁弁３１を通過し、キャピラリー３０を介して第２熱源側熱交換器である第２室外熱交換器６２の順に流れることになる。 When performing a hot water supply operation in heat pump hot water supply apparatus 100 according to Embodiment 2, control apparatus 20 controls to open electromagnetic valve 31. Then, the refrigerant flows as indicated by a solid line arrow A. That is, the refrigerant that has passed through the second expansion valve 5 flows through the low pressure pipe 12 and flows into the first outdoor heat exchanger 61 that is the first heat source side heat exchanger, and then flows through the pipe 15 and passes through the electromagnetic valve 31. Then, the second outdoor heat exchanger 62 that is the second heat source side heat exchanger flows through the capillary 30 in this order.

電磁弁３１及びキャピラリー３０による圧力損失により、第１室外熱交換器６１における蒸発温度は、第２室外熱交換器６２の蒸発温度よりも高い。これにより、室外熱交換器の下側に設置されている第１室外熱交換器６１における外気との熱交換量は少なくなる。デフロスト運転時には第１室外熱交換器６１の鉛直方向上側にある第２室外熱交換器６２の霜が溶解し、第１室外熱交換器６１に水が滴下するが、第１室外熱交換器６１の通常運転時の熱交換量が少ないため、第１室外熱交換器６１表面に水が残っていても再凝固を緩和することができる。なお、電磁弁３１及びキャピラリー３０による圧力損失は、第１室外熱交換器６１の蒸発温度が外気温度よりも高くなって放熱することを防ぐため、定格冷媒流量において圧力損失が蒸発温度換算で１０℃以下となるように流動抵抗を設計するとよい。 Due to the pressure loss due to the solenoid valve 31 and the capillary 30, the evaporation temperature in the first outdoor heat exchanger 61 is higher than the evaporation temperature of the second outdoor heat exchanger 62. Thereby, the amount of heat exchange with the outside air in the first outdoor heat exchanger 61 installed on the lower side of the outdoor heat exchanger is reduced. During the defrosting operation, frost in the second outdoor heat exchanger 62 on the upper side in the vertical direction of the first outdoor heat exchanger 61 is melted and water is dripped into the first outdoor heat exchanger 61. However, the first outdoor heat exchanger 61 Since the amount of heat exchange during normal operation is small, resolidification can be mitigated even if water remains on the surface of the first outdoor heat exchanger 61. The pressure loss due to the solenoid valve 31 and the capillary 30 is 10% in terms of evaporation temperature at the rated refrigerant flow rate in order to prevent the evaporation temperature of the first outdoor heat exchanger 61 from becoming higher than the outside air temperature and dissipating heat. It is good to design the flow resistance so that it is below ℃.

このヒートポンプ式給湯装置１００ａの冷媒回路Ａにおいて、ホットガスバイパス方式のデフロスト運転（第１のデフロスト運転）を行なう場合、第２室外熱交換器６２にホットガスを流入される必要があるため、バイパス配管１４は、吐出配管１０と配管１５とを接続するようになっている。また、ホットガスバイパス方式のデフロスト運転中は、電磁弁３１を閉じるように制御すれば、第２室外熱交換器６２に直接ホットガスが流入することになり、第２室外熱交換器６２に効率的にホットガスを流入させられる。 In the refrigerant circuit A of the heat pump hot water supply device 100a, when performing a hot gas bypass type defrost operation (first defrost operation), it is necessary to introduce hot gas into the second outdoor heat exchanger 62. The pipe 14 connects the discharge pipe 10 and the pipe 15. Further, during the hot gas bypass type defrost operation, if the solenoid valve 31 is controlled to be closed, the hot gas directly flows into the second outdoor heat exchanger 62, and the second outdoor heat exchanger 62 has an efficiency. Hot gas can be introduced.

以上のように、ヒートポンプ式給湯装置１００ａでは、ホットガス方式のデフロスト運転を実行する。したがって、給湯運転とホットガスバイパス方式のデフロスト運転とを繰り返す場合、デフロスト運転でレシーバー４に溜められた冷熱は、給湯運転復帰後にレシーバー４から室外熱交換器に移動し、処理される。このデフロスト運転では、第１膨張弁３及び第２膨張弁５が閉止しているため、凝縮器（水熱交換器２）、レシーバー４、及び、室外熱交換器それぞれの冷媒分布が給湯運転から変化しない。 As described above, in the heat pump hot water supply apparatus 100a, the hot gas type defrost operation is executed. Accordingly, when the hot water supply operation and the hot gas bypass type defrost operation are repeated, the cold heat accumulated in the receiver 4 in the defrost operation is transferred from the receiver 4 to the outdoor heat exchanger after the hot water supply operation is returned and processed. In this defrost operation, since the first expansion valve 3 and the second expansion valve 5 are closed, the refrigerant distribution of each of the condenser (water heat exchanger 2), the receiver 4, and the outdoor heat exchanger is changed from the hot water supply operation. It does not change.

したがって、ヒートポンプ式給湯装置１００ａ、及び、このヒートポンプ式給湯装置１００ａが実行する制御方法では、第１のデフロスト運転方法により冷凍サイクル内における通常運転時の冷媒分布とデフロスト運転時の冷媒分布との変化幅を低減することができる。また、デフロスト中に発生した冷熱はレシーバー４に溜められている。この冷熱は冷媒回路から独立しており、水熱交換器２の能力の立ち上がりに影響を及ぼさない。これらのことから、通常運転への復帰後の水熱交換器２の能力の立ち上がりが早くなり、性能低下を抑制することができる。よって、平均能力及び平均ＣＯＰを大幅に向上させることが可能になるとともに、省エネルギー化に大きく寄与することになる。 Therefore, in the heat pump hot water supply apparatus 100a and the control method executed by the heat pump hot water supply apparatus 100a, the first defrost operation method changes the refrigerant distribution during normal operation and the refrigerant distribution during defrost operation in the refrigeration cycle. The width can be reduced. Further, the cold generated during the defrost is stored in the receiver 4. This cold heat is independent of the refrigerant circuit and does not affect the rise of the capacity of the water heat exchanger 2. From these things, the start-up of the capacity of the water heat exchanger 2 after returning to normal operation is quickened, and performance degradation can be suppressed. Therefore, it is possible to greatly improve the average capacity and the average COP, and greatly contribute to energy saving.

実施の形態１及び実施の形態２では、冷媒回路Ａ内を循環する冷媒にＲ４１０Ａを使用した場合を例に説明したが、冷媒の種類を特に限定するものではなく、たとえば二酸化炭素や炭化水素、ヘリウム等のような自然冷媒、ＨＦＣ４０７Ｃ等の代替冷媒のような塩素を含まない冷媒、もしくは既存の製品に使用されているＲ２２やＲ１３４ａ等のフロン系冷媒のいずれでもよい。また、圧縮機１は、レシプロ、ロータリー、スクロール、あるいは、スクリュー等の各種タイプのいずれのものを用いてもよく、回転数可変可能のものでもよく、回転数固定のものでもよい。 In the first embodiment and the second embodiment, the case where R410A is used as the refrigerant circulating in the refrigerant circuit A has been described as an example. However, the type of the refrigerant is not particularly limited. For example, carbon dioxide, hydrocarbons, Either a natural refrigerant such as helium or the like, a refrigerant containing no chlorine such as an alternative refrigerant such as HFC407C, or a CFC-based refrigerant such as R22 or R134a used in existing products may be used. The compressor 1 may be any of various types such as a reciprocating, a rotary, a scroll, or a screw. The compressor 1 may be capable of changing the rotational speed or may be fixed.

１圧縮機、２水熱交換器、２ａポンプ、３第１膨張弁、４レシーバー、５第２膨張弁、６室外熱交換器、６ａ室外ファン、７冷媒−冷媒熱交換器、８バイパス膨張弁、９四方弁、１０吐出配管、１１中圧管、１２低圧管、１３吸入配管、１４バイパス配管、１５配管、１６水配管、２０制御装置、２０ａメモリ、２１吸入圧力検出器、２２吐出圧力検出器、２３第１温度検出器、２４第２温度検出器、２５第３温度検出器、２６第４温度検出器、２７第５温度検出器、２８第６温度検出器、３０キャピラリー、３１電磁弁、６１第１室外熱交換器、６２第２室外熱交換器、１００ヒートポンプ式給湯装置、１００ａヒートポンプ式給湯装置、Ａ冷媒回路、Ｂ水回路。 DESCRIPTION OF SYMBOLS 1 Compressor, 2 Water heat exchanger, 2a pump, 3 1st expansion valve, 4 Receiver, 5 2nd expansion valve, 6 Outdoor heat exchanger, 6a Outdoor fan, 7 Refrigerant-refrigerant heat exchanger, 8 Bypass expansion valve , 9 Four-way valve, 10 Discharge pipe, 11 Medium pressure pipe, 12 Low pressure pipe, 13 Suction pipe, 14 Bypass pipe, 15 Pipe, 16 Water pipe, 20 Control device, 20a Memory, 21 Suction pressure detector, 22 Discharge pressure detector , 23 First temperature detector, 24 Second temperature detector, 25 Third temperature detector, 26 Fourth temperature detector, 27 Fifth temperature detector, 28 Sixth temperature detector, 30 Capillary, 31 Solenoid valve, 61 1st outdoor heat exchanger, 62 2nd outdoor heat exchanger, 100 heat pump type hot water supply apparatus, 100a heat pump type hot water supply apparatus, A refrigerant circuit, B water circuit.

Claims

A compressor, a load side heat exchanger, a first expansion valve, a receiver, a second expansion valve, and a refrigerant circuit in which a heat source side heat exchanger is sequentially connected;
A refrigerant-refrigerant heat exchanger for exchanging heat between the refrigerant flowing through the intermediate pressure pipe connecting the first expansion valve and the second expansion valve and the refrigerant flowing through the suction pipe of the compressor;
A bypass pipe for connecting a discharge pipe of the compressor, and a low pressure pipe connecting the second expansion valve and the heat source side heat exchanger;
A bypass expansion valve provided in the bypass pipe;
The first expansion valve and the second expansion valve are closed, and the opening degree of the bypass expansion valve is controlled according to the degree of superheat of the refrigerant sucked into the compressor or the degree of superheat of the refrigerant discharged from the compressor. And a control device for performing defrosting operation.

The heat source side heat exchanger is divided into a first heat source side heat exchanger and a second heat source side heat exchanger,
A throttle means is provided between the first heat source side heat exchanger and the second heat source side heat exchanger,
The bypass pipe connects the discharge pipe and a pipe connecting the first heat source side heat exchanger and the second heat source side heat exchanger to each other. The refrigeration cycle apparatus described.

The refrigeration cycle apparatus according to claim 2, wherein the second heat source side heat exchanger is disposed vertically above the first heat source side heat exchanger.

A compressor, a load side heat exchanger, a first expansion valve, a receiver, a second expansion valve, and a refrigerant circuit in which a heat source side heat exchanger is sequentially connected;
A refrigerant-refrigerant heat exchanger for exchanging heat between the refrigerant flowing through the intermediate pressure pipe connecting the first expansion valve and the second expansion valve and the refrigerant flowing through the suction pipe of the compressor;
A bypass pipe for connecting a discharge pipe of the compressor, and a low pressure pipe connecting the second expansion valve and the heat source side heat exchanger;
A bypass expansion valve provided in the bypass pipe, and a control method of a refrigeration cycle apparatus comprising:
The first expansion valve and the second expansion valve are closed, and the opening degree of the bypass expansion valve is controlled in accordance with the degree of superheat of the refrigerant sucked into the compressor or the degree of superheat of the refrigerant discharged from the compressor. A control method for the refrigeration cycle apparatus, wherein the defrosting operation is executed by the control.

In the refrigeration cycle apparatus, the heat source side heat exchanger is divided into a first heat source side heat exchanger and a second heat source side heat exchanger,
A throttle means is provided between the first heat source side heat exchanger and the second heat source side heat exchanger,
The discharge pipe and the pipe connecting the first heat source side heat exchanger and the second heat source side heat exchanger are connected by the bypass pipe,
5. The refrigeration cycle apparatus according to claim 4, wherein the defrosting operation is performed so that the refrigerant discharged from the compressor flows into the second heat source side heat exchanger by closing the throttle means. Control method.

6. The refrigeration cycle according to claim 4, wherein when the high-pressure side pressure becomes larger than a predetermined value, the refrigerant amount in the high-pressure side circuit is adjusted by temporarily opening the first expansion valve. Device control method.

The refrigerant amount of the low-pressure side circuit is adjusted by temporarily opening the second expansion valve when the low-pressure side pressure becomes smaller than a predetermined value. A control method for the refrigeration cycle apparatus according to claim 1.

The refrigeration cycle apparatus is provided with a flow path switching device that switches a refrigerant flow path on the discharge side of the compressor,
The refrigeration operation pattern is changed by controlling the flow path switching device according to an outside air temperature or a frost formation amount of the outdoor heat exchanger. The refrigeration according to any one of claims 4 to 7, Control method for cycle equipment.