JP2009030903A

JP2009030903A - Hot water storage type water heater

Info

Publication number: JP2009030903A
Application number: JP2007196561A
Authority: JP
Inventors: Satoshi Fujita; 聡藤田; Toshiyuki Sakuma; 利幸佐久間
Original assignee: Mitsubishi Electric Corp
Current assignee: Mitsubishi Electric Corp
Priority date: 2007-07-27
Filing date: 2007-07-27
Publication date: 2009-02-12

Abstract

PROBLEM TO BE SOLVED: To provide a hot water storage type water heater saving use amount of high temperature water consumed during operation to prevent freezing of a reheating heat source side circulation circuit and reducing running cost. SOLUTION: The hot water storage type water heater is provided with a hot water storage tank; the reheating heat source side circulation circuit for returning hot water in the hot water storage tank to the hot water storage tank; a reheating circulating pump for circulating hot water through the reheating heat source side circulation circuit; a bath water circulation circuit; and a heat exchanger performing heat exchange between the hot water in the reheating heat source side circulation circuit and bath water in the bath water circulation circuit. The hot water storage type water heater is further provided with a temperature sensor; a bath water detector for detecting presence/absence of bath water; and a control part for executing intermittent operation of the reheating circulating pump when the temperature of the temperature sensor becomes a predetermined temperature or lower, and reducing the amount of hot water made flow in the reheating heat source side circulation circuit when no bath water is detected by the bath water detector compared to when bath water is detected. COPYRIGHT: (C)2009,JPO&INPIT

Description

本発明は、浴槽水追焚き機能を備えた貯湯式給湯機に関するものである。 The present invention relates to a hot water storage type water heater having a bathtub water replenishing function.

風呂浴槽水の追焚き機能を備えた貯湯式給湯機は、一般的に、貯湯タンクから供給される高温水の熱でもって浴槽水の追焚きをする。具体的には、貯湯式給湯機が、追焚き循環ポンプにより貯湯タンクからの高温水を取り込んで循環させる追焚き熱源側循環回路と、浴槽水循環ポンプにより浴槽水を取り込んで循環させる浴槽水循環回路と、貯湯タンクからの高温水と浴槽水との間で熱交換を行う熱交換器とを有している。このような貯湯式給湯機においては、追焚きしていない場合、追焚き循環ポンプは停止しているので、追焚きしていない場合でかつ外気温が低下する場合、追焚き熱源側循環回路が凍結する危険に晒される。 In general, a hot water storage type water heater equipped with a bath tub water replenishment function replenishes bathtub water with the heat of high-temperature water supplied from a hot water storage tank. Specifically, a hot water storage type hot water supply device takes in and circulates hot water from a hot water storage tank by a recirculation circulation pump, and a tub water circulation circuit in which bath water is taken in and circulated by a bathtub water circulation pump. And a heat exchanger that exchanges heat between the hot water from the hot water storage tank and the bathtub water. In such a hot water storage type water heater, the recirculation circulation pump is stopped when not reheating, so when the reheating is not performed and the outside air temperature decreases, the recirculation heat source side circulation circuit is You are exposed to the risk of freezing.

そのため、特許文献１においては、外気温検出部が所定温度以下を検出すると、追焚き循環ポンプの運転を行い、貯湯タンク内の高温水を追焚き熱源側循環回路へ連続的または間欠的に循環して追焚き熱源側循環回路の凍結を防止している。 For this reason, in Patent Document 1, when the outside air temperature detection unit detects a predetermined temperature or lower, the recirculation circulation pump is operated, and high temperature water in the hot water storage tank is recirculated continuously or intermittently to the heat source side circulation circuit. Thus, freezing of the recirculation circuit on the heat source side is prevented.

特開２００６−３００４７０号公報JP 2006-300470 A

しかしながら、特許文献１に提案される方法では、貯湯式給湯機は浴槽における浴槽水の有無に関係なく追焚き循環ポンプを運転する。浴槽に浴槽水が有り、浴槽水循環回路が水で満たされている場合は、熱交換器部分に浴槽水が滞留しているので、追焚き熱源側循環回路の水の熱損失が大きいが、浴槽水が無い場合は、浴槽水循環回路内には水が無く、熱交換器部分の浴槽水も空になっているので、浴槽水が有る場合に比べて追焚き熱源側循環回路内の水の熱交換器での熱損失は小さい。従って、凍結予防運転時において、浴槽水が無しの場合、浴槽水が有りの場合よりも追焚き熱源側循環回路の温度低下が軽減されるため、浴槽水が有りの場合よりも追焚き熱源側循環回路での高温水の使用量は少なくてよい。特許文献１に提案されている追焚き熱源側循環回路の凍結防止制御においては、このことが考慮されていないため、凍結予防運転時の高温水のトータル使用量を考えると無駄があり、ランニングコストが大きいという問題があった。 However, in the method proposed in Patent Document 1, the hot water storage type hot water heater operates the recirculation circulation pump regardless of the presence or absence of bathtub water in the bathtub. When there is bathtub water in the bathtub and the bathtub water circulation circuit is filled with water, the heat loss in the heat source side circulation circuit is large because the bathtub water stays in the heat exchanger part. When there is no water, there is no water in the bathtub water circulation circuit, and the bathtub water in the heat exchanger is also empty, so the heat of the water in the additional heat source side circulation circuit is larger than when there is bathtub water. The heat loss in the exchanger is small. Therefore, during freezing prevention operation, when there is no bathtub water, the temperature drop of the circulation heat source side circulation circuit is reduced more than when there is bathtub water, so the additional heat source side than when there is bathtub water. The amount of hot water used in the circulation circuit may be small. In the antifreezing control of the additional heat source side circulation circuit proposed in Patent Document 1, this is not taken into consideration, so there is waste when considering the total amount of high-temperature water used in the freeze prevention operation, and the running cost There was a problem that was large.

本発明は、上記に鑑みてなされたものであって、追焚き熱源側循環回路の凍結を予防する運転を行う際に消費する高温水の使用量を節約し、ランニングコストを低減する貯湯式給湯機を提供することを目的とする。 The present invention has been made in view of the above, and is a hot water storage type hot water supply system that saves the amount of high-temperature water consumed when performing an operation for preventing freezing of the additional heat source side circulation circuit and reduces running costs. The purpose is to provide a machine.

上述した課題を解決し、目的を達成するために、本発明は、加熱手段によって内部の水を加熱して得た湯水を内部に貯留する貯湯タンクと、前記貯湯タンクに貯留された湯水を前記貯湯タンクへ戻す追焚き熱源側循環回路と、この追焚き熱源側循環回路に湯水を循環させる追焚き循環ポンプと、浴槽に浴槽水を循環させる浴槽水循環回路と、この浴槽水循環回路に浴槽水を循環させる浴槽水循環ポンプと、前記追焚き熱源側循環回路を循環する湯水と前記浴槽水循環回路を循環する浴槽水との間で熱交換する熱交換器とを備える貯湯式給湯機において、所定の温度を検出する温度センサと、浴槽における浴槽水の有無を検出する浴槽水検出部と、前記温度センサが所定の温度以下になると前記追焚き循環ポンプの間欠運転を実行するとともに、前記浴槽水検出部が浴槽水がないことを検出した場合は、前記浴槽水検出部が浴槽水があることを検出した場合に比べ、前記追焚き熱源側循環回路に流す湯水の量が少なくなるように前記間欠運転を行う制御部と、を備えることを特徴とする。 In order to solve the above-described problems and achieve the object, the present invention provides a hot water storage tank for storing hot water obtained by heating internal water by a heating means, and hot water stored in the hot water storage tank. Reheating heat source side circulation circuit returning to the hot water storage tank, reheating circulation pump for circulating hot water in the reheating heat source side circulation circuit, bath water circulation circuit for circulating bath water in the bathtub, and bath water in the bathtub water circulation circuit In a hot water storage type hot water heater comprising a bathtub water circulation pump to be circulated, hot water circulating in the additional heat source side circulation circuit, and a heat exchanger exchanging heat between bathtub water circulating in the bathtub water circulation circuit, a predetermined temperature A temperature sensor for detecting the presence of water, a bath water detector for detecting the presence or absence of bathtub water in the bathtub, and intermittent operation of the recirculation circulation pump when the temperature sensor falls below a predetermined temperature. When the bathtub water detector detects that there is no bathtub water, the amount of hot water flowing through the reheating heat source side circulation circuit is smaller than when the bathtub water detector detects that there is bathtub water. And a controller that performs the intermittent operation.

本発明によれば、貯湯式給湯機は、追焚き熱源側循環回路の凍結予防を目的として追焚き熱源側循環回路の追焚き循環ポンプの運転を行う際、浴槽に浴槽水がない場合、浴槽に浴槽水がある場合に比べて、使用する高温水の量を少なくするように、追焚き循環ポンプの間欠運転を行う。これにより、追焚き熱源側循環回路の凍結を防止する運転を行う際に消費する高温水の使用量を節約し、ランニングコストを低減する貯湯式給湯機を提供することができる。 According to the present invention, when the hot water storage type hot water heater operates the additional circulation pump of the additional heat source side circulation circuit for the purpose of preventing freezing of the additional heat source side circulation circuit, The recirculation circulation pump is intermittently operated so as to reduce the amount of high-temperature water used compared to the case where there is bathtub water. Accordingly, it is possible to provide a hot water storage type hot water heater that saves the amount of high-temperature water consumed when performing an operation for preventing freezing of the additional heat source side circulation circuit and reduces the running cost.

以下に、本発明にかかる貯湯式給湯機の実施の形態を図面に基づいて詳細に説明する。なお、この実施の形態によりこの発明が限定されるものではない。 Embodiments of a hot water storage type water heater according to the present invention will be described below in detail with reference to the drawings. Note that the present invention is not limited to the embodiments.

実施の形態１．
本発明に係る貯湯式給湯機の実施の形態１の構成および動作について説明する。図１は実施の形態１による貯湯式給湯機の構成を示す図である。 Embodiment 1 FIG.
The configuration and operation of Embodiment 1 of the hot water storage type hot water heater according to the present invention will be described. FIG. 1 is a diagram showing a configuration of a hot water storage type water heater according to the first embodiment.

まず、貯湯式給湯機の、貯湯タンクおよび貯湯タンク内の水を加熱する機能を持つ部分の構成について説明する。図１において、貯湯式給湯機１００は、湯水を貯留する貯湯タンク１と、貯湯タンク１内の水を加熱するヒートポンプユニット２と、貯湯タンク１の下部の低温水をヒートポンプユニット２に導くヒートポンプ往き配管３と、貯湯タンク１の下部より低温水を取水しヒートポンプユニット２に循環させる、ヒートポンプ往き配管３に設けられた加熱循環ポンプ４と、ヒートポンプユニット２により加熱された水を貯湯タンク１の上部に導くヒートポンプ戻り配管５とを有する。貯湯タンク１、ヒートポンプユニット２、ヒートポンプ往き配管３、およびヒートポンプ戻り配管５は貯湯タンク１内の湯水を循環させながら加熱する加熱循環水路を構成し、加熱循環ポンプ４は湯水循環の駆動力を与える。 First, the structure of the hot water storage water heater of the hot water storage tank and the portion having the function of heating the water in the hot water storage tank will be described. In FIG. 1, a hot water storage type hot water heater 100 includes a hot water storage tank 1 for storing hot water, a heat pump unit 2 for heating water in the hot water storage tank 1, and a heat pump going to guide the low temperature water in the lower part of the hot water storage tank 1 to the heat pump unit 2. A low-temperature water is taken from the pipe 3 and the lower part of the hot water storage tank 1 and is circulated to the heat pump unit 2. The heating circulation pump 4 provided in the heat pump outgoing pipe 3 and the water heated by the heat pump unit 2 are And a heat pump return pipe 5 leading to The hot water storage tank 1, the heat pump unit 2, the heat pump forward piping 3, and the heat pump return piping 5 constitute a heating circulation channel that heats while circulating the hot water in the hot water storage tank 1, and the heating circulation pump 4 provides a driving force for hot water circulation. .

次に、貯湯式給湯機１００に内蔵される貯湯タンク１への給水と、ユーザが給水栓（図示せず）から所定の温度の水を得るための機能をもつ部分の構成について説明する。図１において、貯湯式給湯機１００は、水源（図示せず）より水を取水する給水配管９と、貯湯タンク１の上部より高温水を取水する出湯配管１０と、給水配管９を経由して供給される水と出湯配管１０を経由して貯湯タンク１より取水される高温水とを所定の混合比で混合し所定温度に温度調整する混合弁１１と、混合弁１１により所定温度に温度調整された湯水をユーザに供給する給湯配管１２とを有する。給水配管９には、給水される水の温度を検出する給水温センサ１９が取り付けられている。給水配管９は、混合弁１１に接続される前に分岐し、分岐した一端が貯湯タンク１の下部に接続されており、貯湯タンク１にも水を供給する。 Next, the structure of the part which has the function for the water supply to the hot water storage tank 1 incorporated in the hot water storage type hot water supply apparatus 100 and a user to obtain the water of predetermined temperature from a water tap (not shown) is demonstrated. In FIG. 1, a hot water storage type hot water heater 100 passes through a water supply pipe 9 for taking water from a water source (not shown), a hot water supply pipe 10 for taking high temperature water from the upper part of the hot water storage tank 1, and a water supply pipe 9. Mixing the supplied water and high-temperature water taken from the hot water storage tank 1 via the hot water supply pipe 10 at a predetermined mixing ratio and adjusting the temperature to a predetermined temperature, and adjusting the temperature to the predetermined temperature by the mixing valve 11 And a hot water supply pipe 12 for supplying the hot water to the user. A water supply temperature sensor 19 for detecting the temperature of the supplied water is attached to the water supply pipe 9. The water supply pipe 9 branches before being connected to the mixing valve 11. One end of the branch is connected to the lower part of the hot water storage tank 1, and supplies water to the hot water storage tank 1.

次に、貯湯式給湯機１００が浴槽水を取水して追焚きをする機能を担う部分の構成について説明する。まず、貯湯式給湯機１００は、図１において、浴槽水循環回路１３と、浴槽水循環ポンプ１４とを有し、浴槽水循環回路１３は浴槽１６に２箇所で接続されている。浴槽水循環回路１３は、さらに熱交換器７に接続されている。熱交換器７、浴槽水循環回路１３、および浴槽１６は、浴槽水を循環させながら追焚き加熱する浴槽水循環水路を構成する。浴槽水循環回路１３には浴槽水循環ポンプ１４が設置されており、浴槽水循環ポンプ１４は、浴槽水循環水路内において浴槽水を循環させる駆動力を与える。浴槽水循環回路１３には、圧力センサ等からなる浴槽水検出器１５が設置されており、浴槽水検出器１５は浴槽１６内の湯水の有無を検出する。浴槽水循環回路１３には、浴槽１６から熱交換器７へ向かう浴槽水の温度を検出する浴槽水循環入口温センサ１７と、熱交換器７から浴槽１６へ向かう浴槽水の温度を検出する浴槽水循環出口温センサ１８とが設置されており、浴槽水循環回路１３において夫々浴槽１６から取水した直後の浴槽水温度と、浴槽１６に戻す直前の浴槽水温度を検出する。 Next, the structure of the part which bears the function in which the hot water storage type hot water heater 100 takes in bathtub water and carries out reheating is demonstrated. First, the hot water storage type water heater 100 has a bathtub water circulation circuit 13 and a bathtub water circulation pump 14 in FIG. 1, and the bathtub water circulation circuit 13 is connected to the bathtub 16 at two locations. The bathtub water circulation circuit 13 is further connected to the heat exchanger 7. The heat exchanger 7, the bathtub water circulation circuit 13, and the bathtub 16 constitute a bathtub water circulation channel that heats up and circulates the bathtub water. A bathtub water circulation pump 14 is installed in the bathtub water circulation circuit 13, and the bathtub water circulation pump 14 provides a driving force for circulating the bathtub water in the bathtub water circulation channel. The bathtub water circulation circuit 13 is provided with a bathtub water detector 15 composed of a pressure sensor or the like, and the bathtub water detector 15 detects the presence or absence of hot water in the bathtub 16. The bathtub water circulation circuit 13 includes a bathtub water circulation inlet temperature sensor 17 that detects the temperature of the bathtub water that travels from the bathtub 16 to the heat exchanger 7, and a bathtub water circulation outlet that detects the temperature of the bathtub water that travels from the heat exchanger 7 to the bathtub 16. The temperature sensor 18 is installed, and the bathtub water temperature immediately after taking water from the bathtub 16 in the bathtub water circulation circuit 13 and the bathtub water temperature just before returning to the bathtub 16 are detected.

さらに、貯湯式給湯機１００は、図１において、追焚き熱源側循環回路６と、追焚き熱源側循環回路６中に設置された追焚き循環ポンプ８とを有する。追焚き熱源側循環回路６は貯湯タンク１の上部と下部の二箇所および熱交換器７に接続されている。貯湯タンク１、追焚き熱源側循環回路６、および熱交換器７は、貯湯タンク１から供給される高温水を循環させ、前記した浴槽水循環水路を循環する浴槽水に熱交換器７において熱を与える、追焚き熱源側循環水路を構成する。追焚き熱源側循環水路中を循環する高温水の循環駆動力は、追焚き循環ポンプ８より得る。 Further, in FIG. 1, the hot water storage type water heater 100 has a reheating heat source side circulation circuit 6 and a reheating circulation pump 8 installed in the reheating heat source side circulation circuit 6. The reheating heat source side circulation circuit 6 is connected to the upper and lower portions of the hot water storage tank 1 and the heat exchanger 7. The hot water storage tank 1, the reheating heat source side circulation circuit 6, and the heat exchanger 7 circulate high temperature water supplied from the hot water storage tank 1, and heat in the heat exchanger 7 to the bathtub water circulating through the bathtub water circulation channel. Construct a recirculation heat source side circulation channel. The circulation driving force of the high-temperature water circulating in the additional heat source side circulation channel is obtained from the additional circulation pump 8.

このように、追焚き循環ポンプ８の働きにより追焚き熱源側循環回路６中を流れる高温水は、熱交換器７にて、浴槽水循環ポンプ１４の働きにより浴槽水循環回路１３中を流れる浴槽水に熱を与えることで、浴槽水の追焚きを行う。 In this way, the high-temperature water flowing in the reheating heat source side circulation circuit 6 by the function of the recirculation circulation pump 8 is converted into bathtub water flowing in the bathtub water circulation circuit 13 by the function of the bathtub water circulation pump 14 in the heat exchanger 7. Replenish bath water by giving heat.

貯湯式給湯機１００は、さらに、外気温度を検出する外気温センサ２０を有している。また、貯湯式給湯機１００は制御部２１を有し、制御部２１は、浴槽水循環入口温センサ１７、浴槽水循環出口温センサ１８、給水温センサ１９、および外気温センサ２０のセンサ出力と、浴槽水検出器１５の出力信号とを受付け、加熱循環ポンプ４、追焚き循環ポンプ８、および浴槽水循環ポンプ１４の動作を制御する信号を出力する。 The hot water storage type water heater 100 further includes an outside air temperature sensor 20 that detects the outside air temperature. Moreover, the hot water storage type water heater 100 has a control unit 21, and the control unit 21 outputs the bathtub water circulation inlet temperature sensor 17, the bathtub water circulation outlet temperature sensor 18, the water supply temperature sensor 19, and the sensor output of the outside air temperature sensor 20, and the bathtub The output signal of the water detector 15 is received, and a signal for controlling the operation of the heating circulation pump 4, the recirculation circulation pump 8, and the bathtub water circulation pump 14 is output.

次に、本発明にかかる実施の形態１の貯湯式給湯機の動作について説明する。 Next, operation | movement of the hot water storage type water heater of Embodiment 1 concerning this invention is demonstrated.

まず、貯湯タンク１は、水源から給水配管９を通して給水される。ここで、貯湯タンク１は常に満水状態となるよう、使用された水と同じ量の水が適宜給水され、沸き上げられる。 First, the hot water storage tank 1 is supplied with water from a water source through a water supply pipe 9. Here, the hot water storage tank 1 is appropriately supplied with water of the same amount as the used water so that the hot water tank 1 is always full.

次に、貯湯タンク１中の湯水を沸き上げる動作について説明する。制御部２１が沸き上げ動作を行うために加熱循環ポンプ４を動作させると、貯湯タンク１に貯えられる湯水は、貯湯タンク１の下部から取水され、ヒートポンプ往き配管３を通り、ヒートポンプユニット２にて加熱され、ヒートポンプ戻り配管５を通り、貯湯タンク１上部に戻される。貯湯タンク１内の水は、このように貯湯タンク１とヒートポンプユニット２間を循環することによって沸き上げられる。 Next, the operation of boiling hot water in the hot water storage tank 1 will be described. When the controller 21 operates the heating circulation pump 4 to perform the boiling operation, the hot water stored in the hot water storage tank 1 is taken from the lower part of the hot water storage tank 1, passes through the heat pump forward piping 3, and is heated by the heat pump unit 2. Heated, passes through the heat pump return pipe 5, and returned to the upper part of the hot water storage tank 1. The water in the hot water storage tank 1 is boiled by circulating between the hot water storage tank 1 and the heat pump unit 2 in this way.

次に貯湯タンク１内で沸き上げられた高温水の給湯動作について説明する。給湯配管１２の先端に取り付けられた給湯栓を開くことによって、給水配管９を経由して供給される水源からの水と出湯配管１０を経由して貯湯タンク１から供給される高温水とが混合弁１１によって所定の混合比で混合される。所定温度に調整された湯水は給湯配管１２を通して給湯栓より給湯される。 Next, a hot water supply operation of the hot water boiled in the hot water storage tank 1 will be described. By opening a hot water tap attached to the tip of the hot water supply pipe 12, water from a water source supplied via the water supply pipe 9 and high temperature water supplied from the hot water storage tank 1 via the hot water supply pipe 10 are mixed. Mixing is performed at a predetermined mixing ratio by the valve 11. Hot water adjusted to a predetermined temperature is supplied from the hot water tap through the hot water supply pipe 12.

次に浴槽水の追焚き動作について説明する。追焚き動作は、制御部２１が浴槽水循環水路および追焚き熱源側循環水路を同時に動作させることにより行われる。浴槽水循環水路において、制御部２１の制御により浴槽水循環ポンプ１４を運転し、浴槽１６内の浴槽水を浴槽水循環回路１３に導き、熱交換器７を経由して浴槽１６に戻す。追焚き熱源側循環水路では、制御部２１の制御により追焚き循環ポンプ８を運転し、貯湯タンク１内の高温水を貯湯タンク１の上部から追焚き熱源側循環回路６に導き、熱交換器７を経由して貯湯タンク１の下部に戻す。この時、熱交換器７により、貯湯タンク１からの高温水と浴槽１６からの低温の浴槽水との温度差で熱交換が行われ、浴槽水は熱を受熱して昇温し浴槽１６に戻り、貯湯タンク１の上部からの高温水は熱を奪われ温度低下し貯湯タンク１の下部に戻る。 Next, the bath water purging operation will be described. The chasing operation is performed by the control unit 21 operating the bathtub water circulation channel and the chasing heat source side circulation channel simultaneously. In the bathtub water circulation channel, the bathtub water circulation pump 14 is operated under the control of the control unit 21, and the bathtub water in the bathtub 16 is guided to the bathtub water circulation circuit 13 and returned to the bathtub 16 via the heat exchanger 7. In the additional heat source side circulation channel, the additional circulation pump 8 is operated under the control of the control unit 21, and the high-temperature water in the hot water storage tank 1 is guided from the upper part of the hot water storage tank 1 to the additional heat source side circulation circuit 6, and the heat exchanger Return to the bottom of the hot water storage tank 1 via 7. At this time, heat exchange is performed by the heat exchanger 7 due to a temperature difference between the hot water from the hot water storage tank 1 and the cold bath water from the bathtub 16, and the bathtub water receives heat and rises in temperature to the bathtub 16. Returning, the high temperature water from the upper part of the hot water storage tank 1 is deprived of heat and the temperature drops and returns to the lower part of the hot water storage tank 1.

次に、追焚き熱源側循環回路６の凍結防止の制御動作について図２および図３を用いて詳細に説明する。図２は、追焚き熱源側循環回路６の凍結防止の制御動作を説明するフローチャートである。図３は、図２での各動作に使用される各種条件の例を示す表である。 Next, the control operation for preventing freezing of the reheating heat source side circulation circuit 6 will be described in detail with reference to FIGS. FIG. 2 is a flowchart for explaining the control operation for preventing freezing of the reheating heat source side circulation circuit 6. FIG. 3 is a table showing examples of various conditions used for each operation in FIG.

図２において、ステップＳ１０では、制御部２１は、浴槽水循環入口温センサ１７が検出する浴槽水循環入口温度Ｔｉｎを所定第一のしきい値Ｔｉｎ０、浴槽水循環出口温センサ１８が検出する浴槽水循環出口温度Ｔｏｕｔを所定第二のしきい値Ｔｏｕｔ０と比較する。Ｔｉｎ＞Ｔｉｎ０かつＴｏｕｔ＞Ｔｏｕｔ０を満たす場合（ステップＳ１０、Ｎｏ）、ステップＳ１０の判断処理を繰り返す。Ｔｉｎ≦Ｔｉｎ０またはＴｏｕｔ≦Ｔｏｕｔ０のどちらか一方を満たす場合（ステップＳ１０、Ｙｅｓ）、ステップＳ２０に移行する。ここで、例えば図３の開始条件の欄に示すように、例えば、Ｔｉｎ０を３℃、Ｔｏｕｔ０を５℃と設定する。 In FIG. 2, in step S 10, the control unit 21 determines the bath water circulation inlet temperature Tin detected by the bath water circulation inlet temperature sensor 17 as the predetermined first threshold value Tin 0 and the bath water circulation outlet temperature detected by the bath water circulation outlet temperature sensor 18. Tout is compared with a predetermined second threshold value Tout0. When Tin> Tin0 and Tout> Tout0 are satisfied (step S10, No), the determination process of step S10 is repeated. When either Tin ≦ Tin0 or Tout ≦ Tout0 is satisfied (step S10, Yes), the process proceeds to step S20. Here, for example, as shown in the column of the start condition in FIG. 3, for example, Tin0 is set to 3 ° C. and Tout0 is set to 5 ° C.

ステップＳ２０では、制御部２１は、追焚き循環ポンプ８の運転を開始させ、貯湯タンク1の上部にある追焚き熱源側循環回路６のタンク湯取出口から取り出された高温水を追焚き熱源側循環回路６に循環させ、追焚き熱源側循環回路６の凍結予防運転を開始する。次にステップＳ３０に進む。 In step S20, the control unit 21 starts the operation of the recirculation circulation pump 8, and replenishes the high temperature water taken out from the tank hot water outlet of the recirculation heat source side circulation circuit 6 at the top of the hot water storage tank 1 to the reheating heat source side. The circulation circuit 6 is made to circulate, and the freezing prevention operation of the reheating heat source side circulation circuit 6 is started. Next, the process proceeds to step S30.

ステップＳ３０では、制御部２１は、凍結予防運転を運転時間ｔ１が経過するまで継続し、運転時間ｔ１が経過した後、ステップＳ４０に進む。ステップＳ４０では、制御部２１は、追焚き循環ポンプ８の運転を停止させ、ステップＳ５０に移行する。ステップＳ５０では、制御部２１は、浴槽水検出器１５により浴槽１６内の湯水の有無の検出を行い、浴槽１６内に湯水有りを検出した場合（ステップＳ５０、Ｙｅｓ）はステップＳ６０に移行し、浴槽１６内に湯水有りを検出しない場合（ステップＳ５０、Ｎｏ）はステップＳ７０に移行する。ここで、図３の運転時間の欄に示すように、ｔ１は例えば２０秒と設定される。 In step S30, the control unit 21 continues the freeze prevention operation until the operation time t1 elapses, and proceeds to step S40 after the operation time t1 elapses. In step S40, the controller 21 stops the operation of the recirculation circulation pump 8, and proceeds to step S50. In step S50, the control part 21 detects the presence or absence of the hot water in the bathtub 16 with the bathtub water detector 15, and when the presence of hot water in the bathtub 16 is detected (step S50, Yes), the process proceeds to step S60. When hot water is not detected in the bathtub 16 (step S50, No), the process proceeds to step S70. Here, as shown in the column of operation time in FIG. 3, t1 is set to 20 seconds, for example.

ステップＳ６０では、制御部２１は、追焚き循環ポンプ８の運転を運転停止間隔時間ｔ２が経過するまで停止する。運転停止間隔時間ｔ２が経過した後、ステップＳ１０に戻る。ステップＳ７０では、制御部２１は、追焚き循環ポンプ８の運転を運転停止間隔時間ｔ３（ｔ３＞ｔ２）が経過するまで停止する。運転停止間隔時間ｔ３が経過した後、ステップＳ１０に戻る。ここで、図３の運転停止間隔時間の欄に示すように、例えば、ｔ２を１０分、ｔ３を１５分と設定する。ｔ３をｔ２よりも長く設定するのは、浴槽１６内に湯水がない場合は熱交換器７の浴槽水循環水路側は浴槽水で満たされておらず、浴槽１６内に湯水がある場合に比べて追焚き熱源側循環水路６の熱損失が小さくて済むためである。 In step S60, the control unit 21 stops the operation of the recirculation circulation pump 8 until the operation stop interval time t2 elapses. After the operation stop interval time t2 has elapsed, the process returns to step S10. In step S70, the control unit 21 stops the operation of the recirculation circulation pump 8 until the operation stop interval time t3 (t3> t2) elapses. After the operation stop interval time t3 has elapsed, the process returns to step S10. Here, as shown in the column of the operation stop interval time in FIG. 3, for example, t2 is set to 10 minutes and t3 is set to 15 minutes. The reason why t3 is set longer than t2 is that when there is no hot water in the bathtub 16, the bathtub water circulation channel side of the heat exchanger 7 is not filled with bathtub water, compared with the case where hot water is in the bathtub 16. This is because the heat loss of the reheating heat source side circulation channel 6 can be small.

以上のように、本実施の形態１による貯湯式給湯機によれば、追焚きを行うための追焚き熱源側循環回路６の凍結予防のために、追焚き熱源側循環回路６の追焚き循環ポンプ８の運転を間欠的に行い、間欠運転の際の運転停止間隔時間を、浴槽に浴槽水が無い場合は、ある場合に比べて長くとる。これにより、追焚き熱源側循環回路の凍結を予防する運転を行う際に消費する高温水の使用量を節約し、ランニングコストを低減する貯湯式給湯機を提供することができる。 As described above, according to the hot water storage type water heater according to the first embodiment, in order to prevent freezing of the additional heat source side circulation circuit 6 for performing additional heating, the additional circulation of the additional heat source side circulation circuit 6 is performed. The operation of the pump 8 is intermittently performed, and the operation stop interval time during the intermittent operation is longer than that when there is no bathtub water in the bathtub. Accordingly, it is possible to provide a hot water storage type hot water heater that saves the amount of high-temperature water consumed when performing an operation for preventing freezing of the reheating heat source side circulation circuit and reduces the running cost.

なお、ステップＳ１０の判定の動作を、浴槽水循環入口温度Ｔｉｎおよび浴槽水循環出口温度Ｔｏｕｔの代わりに、給水温センサ１９により検出される給水温度または外気温センサ２０により検出される外気温度のいずれかひとつの温度について、制御部２１が夫々の所定のしきい値を比較し、検出温度がそのしきい値以下であるか判定する動作に代えてもよい。この場合、検出温度がしきい値以下である場合にステップＳ２０に移行し、検出温度がしきい値を超える場合にステップＳ１０にとどまる。 Note that the determination operation in step S10 is performed using either the water supply temperature detected by the water supply temperature sensor 19 or the outside air temperature detected by the outside air temperature sensor 20 instead of the bath water circulation inlet temperature Tin and the bath water circulation outlet temperature Tout. Alternatively, the control unit 21 may compare the predetermined threshold values and determine whether the detected temperature is lower than the threshold value. In this case, the process proceeds to step S20 when the detected temperature is equal to or lower than the threshold value, and remains at step S10 when the detected temperature exceeds the threshold value.

また、上記追焚き循環ポンプ８の運転時間ｔ１は、ステップＳ１０において検出された温度によって変更してもよい。例えば、検出温度を、制御部２１がステップＳ１０で使用する所定のしきい値とは異なるしきい値と比較し、検出温度がそのしきい値を超える場合は、しきい値以下の場合に比べてｔ１を短く設定する。これにより、追焚き熱源側循環回路６の凍結予防運転による高温水の使用量をさらに節約することができる。 Further, the operation time t1 of the recirculation circulation pump 8 may be changed according to the temperature detected in step S10. For example, the detected temperature is compared with a threshold value different from the predetermined threshold value used by the control unit 21 in step S10, and when the detected temperature exceeds the threshold value, the detected temperature is lower than the threshold value. T1 is set short. Thereby, the usage-amount of high temperature water by the freezing prevention driving | operation of the reheating heat source side circulation circuit 6 can be further saved.

ところで、図２では、間欠運転の際の各運転停止間隔時間を、浴槽に浴槽水が無い場合は、ある場合に比べて長くとることで、浴槽水が無い場合は、ある場合に比べて追焚き熱源側循環回路６に流す湯水の量が少なくなるようにしたが、間欠運転の際の各運転時間を浴槽水の有無に応じて変化させるようにしてもよいし、間欠運転の際の各運転時間および各運転停止間隔時間の双方を浴槽水の有無に応じて変化させるようにしてもよい。要は、浴槽水がないことを検出した場合は、浴槽水があることを検出した場合に比べ、追焚き熱源側循環回路６に流す湯水の量が少なくなるように間欠運転を行うようにすればよい。 By the way, in FIG. 2, each operation stop interval time at the time of intermittent operation is set longer than that when there is no bathtub water in the bathtub, and when compared with that when there is no bathtub water. Although the amount of hot water flowing through the soaking heat source side circulation circuit 6 is reduced, each operation time during intermittent operation may be changed according to the presence or absence of bath water, You may make it change both operation time and each operation stop interval time according to the presence or absence of bath water. In short, when it is detected that there is no bathtub water, the intermittent operation is performed so that the amount of hot water flowing to the reheating heat source side circulation circuit 6 is smaller than when the presence of bathtub water is detected. That's fine.

実施の形態２．
本発明にかかる実施の形態２の貯湯式給湯機について説明する。ここで、本実施の形態２の貯湯式給湯機の構成は、実施の形態１の貯湯式給湯機と同じであるため、構成についての説明は省略する。 Embodiment 2. FIG.
A hot water storage type water heater according to a second embodiment of the present invention will be described. Here, the configuration of the hot water storage type hot water heater of the second embodiment is the same as that of the hot water storage type hot water heater of the first embodiment, and thus the description of the configuration is omitted.

次に、本実施の形態２の貯湯式給湯機の動作について説明する。図４は、本実施の形態２における貯湯式給湯機の追焚き熱源側循環回路６の凍結予防運転の制御動作についてフローチャートである。その他の動作は、実施の形態１と同様であるので、説明を省略する。本実施の形態２においては、図２におけるステップＳ１０とステップＳ２０との間にステップＳ１１〜Ｓ１３を追加している。即ち、ステップＳ１１で外気温度を−１０℃以上かどうか判定し、その結果により、ステップＳ３０にて制御部２１が使用する間欠運転を行う追焚き循環ポンプ８の運転時間ｔ１、ステップＳ６０にて使用する浴槽水があることを検出した場合の運転停止間隔時間ｔ２、およびステップＳ７０にて使用する浴槽水がないことを検出した場合の運転停止間隔時間ｔ３の設定値を変更するものである。図５は本実施の形態２の動作において使用する各種条件の例をまとめて説明する表である。 Next, the operation of the hot water storage type water heater of the second embodiment will be described. FIG. 4 is a flowchart regarding the control operation of the freeze prevention operation of the reheating heat source side circulation circuit 6 of the hot water storage type hot water supply apparatus according to the second embodiment. Since other operations are the same as those in the first embodiment, the description thereof is omitted. In the second embodiment, steps S11 to S13 are added between step S10 and step S20 in FIG. That is, in step S11, it is determined whether or not the outside air temperature is −10 ° C. or higher. Based on the result, the operation time t1 of the additional circulation pump 8 performing the intermittent operation used by the control unit 21 in step S30 is used in step S60. The operation stop interval time t2 when it is detected that there is bathtub water to be performed, and the set value of the operation stop interval time t3 when it is detected that there is no bathtub water used in step S70 are changed. FIG. 5 is a table that collectively explains examples of various conditions used in the operation of the second embodiment.

具体的に図５の例に従って図４を用いつつ説明すると、ステップＳ１０において制御部２１がＴｉｎ≦Ｔｉｎ０またはＴｏｕｔ≦Ｔｏｕｔ０のどちらか一方を満たすと判定する場合（ステップＳ１０、Ｙｅｓ）、ステップＳ１１に移行する。ステップＳ１０にて制御部２１がＴｉｎ＞Ｔｉｎ０かつＴｏｕｔ＞Ｔｏｕｔ０を満たすと判定する場合（ステップＳ１０、Ｎｏ）、実施の形態１のケースと同様にステップＳ１０の手順を繰り返す。ここで、図５ではＴｉｎ０を３℃、Ｔｏｕｔ０を５℃としている。 Specifically, referring to FIG. 4 according to the example of FIG. 5, if it is determined in step S10 that the control unit 21 satisfies either Tin ≦ Tin0 or Tout ≦ Tout0 (Yes in step S10), the process proceeds to step S11. Transition. When the control unit 21 determines in step S10 that Tin> Tin0 and Tout> Tout0 are satisfied (No in step S10), the procedure of step S10 is repeated as in the case of the first embodiment. Here, in FIG. 5, Tin0 is 3 ° C. and Tout0 is 5 ° C.

ステップＳ１１では、制御部２１は、外気温度が−１０℃以上かどうか判定し、外気温度が−１０℃以上と判定しない場合（ステップＳ１１、Ｎｏ）、ステップＳ１２に移行する。制御部２１は外気温度が−１０℃以上と判定する場合（ステップＳ１１、Ｙｅｓ）、ステップＳ１３に移行する。ステップＳ１２では、制御部２１は、間欠運転の各運転時間ｔ１を２０秒、浴槽水があることを検出される場合の運転停止間隔時間ｔ２を１０分、および浴槽水がないことを検出される場合の運転停止間隔時間ｔ３を１５分と設定し、ステップＳ２０に移行する。ステップＳ１３では、制御部２１は、ｔ１＝１０秒、ｔ２＝３０分、およびｔ３＝４０分と設定し、ステップＳ２０に移行する。 In step S11, the control unit 21 determines whether or not the outside air temperature is −10 ° C. or higher. If the outside air temperature is not determined to be −10 ° C. or higher (No in step S11), the control unit 21 proceeds to step S12. When the control unit 21 determines that the outside air temperature is −10 ° C. or higher (step S11, Yes), the control unit 21 proceeds to step S13. In step S12, the control unit 21 detects that each operation time t1 of intermittent operation is 20 seconds, the operation stop interval time t2 when it is detected that there is bath water, and 10 minutes that there is no bath water. In this case, the operation stop interval time t3 is set to 15 minutes, and the process proceeds to step S20. In step S13, the control unit 21 sets t1 = 10 seconds, t2 = 30 minutes, and t3 = 40 minutes, and proceeds to step S20.

ステップＳ２０〜ステップＳ７０の動作は実施の形態１と同様であるが、制御部２１が使用するｔ１〜ｔ３の値はステップＳ１２またはステップＳ１３のいずれかの動作を経て設定された値が用いられる。 The operations in steps S20 to S70 are the same as those in the first embodiment, but the values set through the operations in either step S12 or step S13 are used as the values of t1 to t3 used by the control unit 21.

ここで、図５に示されるように、外気温度が−１０℃以上と判定される場合は、ｔ１＝１０秒、ｔ２＝３０分、およびｔ３＝４０分、外気温度が−１０℃を下回ると判定される場合は、ｔ１＝２０秒、ｔ２＝１０分、およびｔ３＝１５分と設定されたが、外気温度が−１０℃以上と判定される場合は外気温度が−１０℃を下回ると判定される場合に比べて、運転時間ｔ１は短く、かつ運転停止間隔時間ｔ２およびｔ３は長く設定されるのであれば適宜変更してもかまわない。また、外気温度の判定のしきい値として−１０℃を使用したが、追焚き熱源側循環回路６が凍結しそうな温度の範囲内で変更してもかまわない。 Here, as shown in FIG. 5, when the outside air temperature is determined to be −10 ° C. or higher, t1 = 10 seconds, t2 = 30 minutes, and t3 = 40 minutes, and the outside air temperature falls below −10 ° C. When judged, t1 = 20 seconds, t2 = 10 minutes, and t3 = 15 minutes were set, but when the outside air temperature was judged to be -10 ° C. or higher, the outside air temperature was judged to be lower than −10 ° C. As long as the operation time t1 is shorter and the operation stop interval times t2 and t3 are set longer than the case where the operation time t1 is set, the operation time t1 may be appropriately changed. Further, although −10 ° C. is used as the threshold value for determining the outside air temperature, it may be changed within a temperature range in which the additional heat source side circulation circuit 6 is likely to freeze.

これにより、追焚き熱源側循環回路６が凍結しそうな気温のとき、外気温についてさらにしきい値判定を行い、外気温がしきい値以上の場合は、しきい値を下回る場合に比べて、運転時間を短く、運転停止間隔時間を長くし、高温水の消費量を低減する。 Thereby, when the additional heat source side circulation circuit 6 is at a temperature that is likely to freeze, the threshold value is further determined for the outside air temperature. Shorten the operation time, increase the operation stop interval time, and reduce the consumption of hot water.

以上のように、本実施の形態２の貯湯式給湯機によれば、外気温度によって運転時間と運転停止間隔時間を変更するように実施の形態１の貯湯式給湯機の動作をさらに工夫したことにより、高温水の使用量を実施の形態１の貯湯式給湯機の場合よりもさらに節約できる効果を得ることができる。 As described above, according to the hot water storage type water heater of the second embodiment, the operation of the hot water storage type water heater of the first embodiment is further devised so as to change the operation time and the operation stop interval time according to the outside air temperature. Thereby, the effect which can further save the usage-amount of high temperature water compared with the case of the hot water storage type water heater of Embodiment 1 can be acquired.

ところで、図４では、外気温についてのしきい値判定を実施の形態１における凍結予防運転の制御動作に付け加えることで、外気温がしきい値以下である場合、外気温がしきい値より大きい場合に比べて、間欠運転の際の各運転時間を長く、各運転停止間隔時間を短くし、さらに各運転停止間隔時間について浴槽水の有無による判定により変化させ、浴槽に浴槽水が無い場合は、ある場合に比べて長くしたが、ここで、各運転停止間隔時間ではなく、各運転時間を浴槽水の有無に応じて変化させるようにしてもよい。また、各運転時間および各運転停止間隔時間の両方を浴槽水の有無に応じて変化させるようにしてもよい。要は、外気温がしきい値以下である場合は、外気温がしきい値より大きい場合に比べ追焚き熱源側循環回路６に流す湯水の量が多くなり、浴槽水がないことを検出した場合は、浴槽水があることを検出した場合に比べ追焚き熱源側循環回路６に流す湯水の量が少なくなるように間欠運転を行うようにすればよい。 By the way, in FIG. 4, when the outside air temperature is equal to or lower than the threshold value by adding the threshold value determination regarding the outside air temperature to the control operation of the freeze prevention operation in the first embodiment, the outside air temperature is larger than the threshold value. Compared to the case, each operation time during intermittent operation is lengthened, each operation stop interval time is shortened, and further, each operation stop interval time is changed according to the judgment based on the presence or absence of bath water. Although longer than a certain case, each operation time may be changed according to the presence or absence of bath water instead of each operation stop interval time. Moreover, you may make it change both each operation time and each operation stop interval time according to the presence or absence of bath water. The point is that when the outside air temperature is below the threshold value, the amount of hot water flowing through the additional heat source side circulation circuit 6 is larger than when the outside air temperature is larger than the threshold value, and it is detected that there is no bathtub water. In this case, the intermittent operation may be performed so that the amount of hot water flowing through the reheating heat source side circulation circuit 6 is smaller than when detecting the presence of bathtub water.

貯湯式給湯機の構成図である。It is a block diagram of a hot water storage type water heater. 貯湯式給湯機（実施の形態１）の凍結予防運転の制御動作を説明するフローチャートである。It is a flowchart explaining the control operation | movement of the freeze prevention driving | operation of a hot water storage type water heater (Embodiment 1). 図２にて説明されている動作に使用される、各種条件の例を示す図である。It is a figure which shows the example of various conditions used for the operation | movement demonstrated in FIG. 貯湯式給湯機（実施の形態２）の凍結予防運転の制御動作を説明するフローチャートである。It is a flowchart explaining the control operation | movement of the freeze prevention driving | operation of a hot water storage type water heater (Embodiment 2). 図４にて説明されている動作に使用される、各種条件の例を示す図である。It is a figure which shows the example of various conditions used for the operation | movement demonstrated in FIG.

Explanation of symbols

１貯湯タンク、
２ヒートポンプユニット、
３ヒートポンプ往き配管、
４加熱循環ポンプ、
５ヒートポンプ戻り配管、
６追焚き熱源側循環回路、
７熱交換器、
８追焚き循環ポンプ、
９給水配管、
１０出湯配管、
１１混合弁、
１２給湯配管、
１３浴槽水循環回路、
１４浴槽水循環ポンプ、
１５浴槽水検出器、
１６浴槽、
１７浴槽水循環入口温センサ、
１８浴槽水循環出口温センサ、
１９給水温センサ、
２０外気温センサ、
２１制御部、
１００貯湯式給湯機 1 hot water storage tank,
2 heat pump unit,
3 Heat pump piping
4 Heating circulation pump,
5 Heat pump return piping,
6 Reheating heat source side circulation circuit,
7 heat exchanger,
8 Pursuit circulation pump,
9 Water supply piping,
10 Hot water piping,
11 Mixing valve,
12 Hot water supply piping,
13 Bath water circulation circuit,
14 Bath water circulation pump,
15 bathtub water detector,
16 Bathtub,
17 Bath water circulation inlet temperature sensor,
18 Bath water circulation outlet temperature sensor,
19 Water temperature sensor,
20 outside air temperature sensor,
21 control unit,
100 Hot water storage water heater

Claims

A hot water storage tank for storing hot water obtained by heating the internal water by the heating means, a supplementary heat source side circulation circuit for returning the hot water stored in the hot water storage tank to the hot water storage tank, and this supplementary heat source side circulation A recirculation pump that circulates hot water in the circuit, a tub water circulation circuit that circulates bathtub water in the bathtub, a tub water circulation pump that circulates bathtub water in the bathtub water circulation circuit, and hot water that circulates in the recirculation heat source side circulation circuit And a hot water storage type water heater comprising a heat exchanger for exchanging heat between the bathtub water circulating in the bathtub water circulation circuit,
A temperature sensor for detecting a predetermined temperature;
A bathtub water detector for detecting the presence or absence of bathtub water in the bathtub;
When the temperature sensor falls below a predetermined temperature, the recirculation circulation pump is intermittently operated, and when the bathtub water detection unit detects that there is no bathtub water, the bathtub water detection unit has bathtub water. A control unit that performs the intermittent operation so that the amount of hot water flowing to the reheating heat source side circulation circuit is smaller than the case where it is detected.
A hot water storage type water heater characterized by comprising:

When the said bathtub water detection part detects that there is no bathtub water, the said control part lengthens each operation stop interval time of intermittent operation compared with the case where the said bathtub water detection part detects that there is bathtub water. The hot water storage type water heater according to claim 1, wherein

The hot water storage type hot water heater according to claim 1 or 2, wherein the predetermined temperature sensor is a bathtub water temperature sensor that detects a temperature of bathtub water circulating in the bathtub water circulation circuit.

The bathtub water temperature sensor is a first temperature sensor that detects the temperature of bathtub water sent from the bathtub to the heat exchanger and / or a second temperature sensor that detects the temperature of bathtub water returning from the heat exchanger to the bathtub. The hot water storage type water heater according to claim 3, wherein the hot water storage type water heater is provided.

The predetermined temperature sensor is a third temperature sensor for detecting a temperature of outside air or a fourth temperature sensor for detecting a temperature of water in a water supply pipe for supplying water to the hot water storage tank. Item 3. A hot water storage water heater according to item 1 or 2.

A hot water storage tank for storing hot water obtained by heating the internal water by the heating means, a supplementary heat source side circulation circuit for returning the hot water stored in the hot water storage tank to the hot water storage tank, and this supplementary heat source side circulation A recirculation circulation pump that circulates hot water in the circuit, a tub water circulation circuit that circulates bathtub water in the bathtub, a tub water circulation pump that circulates bathtub water in the bathtub water circulation circuit, and the recirculation heat source side circulation circuit In a hot water storage type water heater comprising a heat exchanger for exchanging heat between hot water and bathtub water circulating in the bathtub water circulation circuit,
A bathtub water temperature sensor for detecting the temperature of the bathtub water circulating in the bathtub water circulation circuit, an outside air temperature sensor for detecting the outside air temperature,
A bathtub water detector for detecting the presence or absence of bathtub water in the bathtub;
When the bath water temperature sensor is equal to or lower than the predetermined first temperature, the recirculation circulation pump is intermittently operated, and when it is detected that the outdoor air temperature sensor is equal to or lower than the predetermined second temperature, Compared to the case where the sensor detects that the temperature is higher than the predetermined second temperature, the amount of hot water flowing through the additional heat source side circulation circuit is increased, and when the bathtub water detection unit detects that there is no bathtub water, Compared with the case where the bathtub water detection unit detects that there is bathtub water, a control unit that performs the intermittent operation so that the amount of hot water flowing to the additional heat source side circulation circuit is reduced,
A hot water storage type water heater characterized by comprising:

When the control unit detects that the outside air temperature sensor is equal to or lower than the predetermined second temperature, each of the intermittent operations is compared with a case where the outside air temperature sensor detects that the temperature is higher than the predetermined second temperature. When the operation time is increased and each operation stop interval time of the intermittent operation is shortened, and the bathtub water detection unit detects that there is no bathtub water, the bathtub water detection unit detects that there is bathtub water The hot water storage type hot water heater according to claim 6, wherein each operation stop interval time of the intermittent operation is longer than that of.