JP5835140B2

JP5835140B2 - Hot water storage water heater

Info

Publication number: JP5835140B2
Application number: JP2012162618A
Authority: JP
Inventors: 平岡　宗; 宗平岡; 昭徳山本; 史人竹内; 尚希渡邉; 恭平飯田; 高橋　健; 高橋　　健
Original assignee: Mitsubishi Electric Corp
Current assignee: Mitsubishi Electric Corp
Priority date: 2012-07-23
Filing date: 2012-07-23
Publication date: 2015-12-24
Anticipated expiration: 2032-07-23
Also published as: JP2014020750A

Description

本発明は、貯湯式給湯機に関する。 The present invention relates to a hot water storage type water heater.

ヒートポンプユニット等の加熱手段により沸き上げた湯を貯留する貯湯タンクと、被加熱物（例えば、浴槽から送られる浴槽水）を加熱するための利用側熱交換器とを備え、貯湯タンクから取り出した湯を熱源水として利用側熱交換器を経由させて貯湯タンクに戻す加熱動作を行うことにより上記被加熱物を加熱可能な貯湯式給湯機が広く用いられている。 A hot water storage tank for storing hot water boiled by heating means such as a heat pump unit and a use side heat exchanger for heating an object to be heated (for example, bathtub water sent from a bathtub) were taken out from the hot water storage tank. A hot water storage type hot water heater capable of heating the object to be heated by performing a heating operation of returning hot water as a heat source water to a hot water storage tank via a use side heat exchanger is widely used.

そのような貯湯式給湯機において、利用側熱交換器での熱交換を終えて貯湯タンクに戻る戻り熱源水を貯湯タンク内に流入させるための回収口を高さ方向の位置を異ならせて複数設け、各回収口の近傍にそれぞれ貯湯タンク内の湯水の温度を検出するタンク温度センサを配設し、戻り熱源水の配管には戻り熱源水の温度を検出する戻り温度センサを設け、利用側熱交換器からの戻り熱源水を貯湯タンクに戻すに際して、制御手段が、戻り温度センサにより検出される戻り熱源水の温度とタンク温度センサにより検出される貯湯タンク内の湯水の温度分布とに応じて戻り熱源水が複数の回収口を通じて貯湯タンクに回収されるように流量調整弁を制御する技術が提案されている（例えば、特許文献１参照）。 In such a hot water storage type hot water heater, a plurality of recovery ports for returning the heat source water that returns to the hot water storage tank and returns to the hot water storage tank into the hot water storage tank at different positions in the height direction after the heat exchange in the use side heat exchanger is completed. A tank temperature sensor that detects the temperature of the hot water in the hot water storage tank is provided near each recovery port, and a return temperature sensor that detects the temperature of the return heat source water is provided in the return heat source water piping. When returning the return heat source water from the heat exchanger to the hot water storage tank, the control means responds to the temperature of the return heat source water detected by the return temperature sensor and the temperature distribution of the hot water in the hot water storage tank detected by the tank temperature sensor. Then, a technique for controlling the flow rate adjustment valve so that the return heat source water is recovered to the hot water storage tank through a plurality of recovery ports has been proposed (see, for example, Patent Document 1).

特開２００７−２７１１６３号公報JP 2007-271163 A

上記公報に開示された貯湯式給湯機では、貯湯タンク内で戻り熱源水の温度に最も近い高低両側の温度成層に所定の分配比率で戻り熱源水を分配することにより、戻り熱源水が、貯湯タンク上部にある高温水や貯湯タンク下部にある低温水と混ざることをできるだけ避け、高温出湯能力の低下を防止するとともに、沸き上げ運転時のヒートポンプユニットの運転効率を高く維持するようにしている。しかしながら、特許文献１の貯湯式給湯機では、高さ方向の位置が異なる多数（実施例では４つ）の回収口を貯湯タンクに設ける必要があり、更には各々の回収口に対して、流量制御弁と戻り熱源水の温度を検出するための温度センサと設ける必要があるなど、貯湯タンクの構造および配管や構成が複雑化し、また制御も複雑になる。このようなことから、上記公報に開示された貯湯式給湯機を実現する場合、製造コストが著しく高くなるという問題がある。 In the hot water storage type water heater disclosed in the above publication, the return heat source water is distributed at a predetermined distribution ratio to the temperature stratification on both sides of the return heat source water closest to the temperature of the return heat source water in the hot water storage tank. It avoids mixing with high-temperature water at the top of the tank and low-temperature water at the bottom of the hot water storage tank as much as possible to prevent a decrease in high-temperature hot-water supply capacity and to maintain high operating efficiency of the heat pump unit during boiling operation. However, in the hot water storage type hot water heater of Patent Document 1, it is necessary to provide a number of recovery ports (four in the embodiment) with different height positions in the hot water storage tank, and further, the flow rate for each recovery port It is necessary to provide a control valve and a temperature sensor for detecting the temperature of the return heat source water. For example, the structure, piping and configuration of the hot water storage tank are complicated, and the control is also complicated. For this reason, when the hot water storage type hot water heater disclosed in the above publication is realized, there is a problem that the manufacturing cost is remarkably increased.

また、戻り熱源水の温度が、給湯に使用可能な温度に満たない中温の場合には、貯湯タンク内の同じ温度の領域に戻して貯留したとしても、給湯に再利用されずに貯湯タンク内に残存し、効率向上に寄与しない場合が多い。そのような場合には、貯湯タンク内に残存した中温水が次回の沸き上げ運転時にヒートポンプユニットに入水することにより、ヒートポンプユニットの効率の低下を招く。 In addition, if the temperature of the return heat source water is a medium temperature that is less than the temperature that can be used for hot water supply, even if the hot water is returned to the same temperature region in the hot water storage tank and stored, it is not reused for hot water supply. In many cases, it does not contribute to efficiency improvement. In such a case, the medium-temperature water remaining in the hot water storage tank enters the heat pump unit during the next boiling operation, thereby causing a reduction in efficiency of the heat pump unit.

本発明は、上述のような課題を解決するためになされたもので、被加熱物を加熱するための利用側熱交換器から貯湯タンクに戻る戻り熱源水を貯湯タンク内に回収する回収口の数をできるだけ減らした低コストの装置構成で、エネルギー効率を向上することができ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 order to solve the above-described problems, and a recovery port for recovering the heat source water returning from the use-side heat exchanger for heating the object to be heated back to the hot water storage tank in the hot water storage tank. An object of the present invention is to provide a hot water storage type hot water heater capable of improving energy efficiency with a low-cost apparatus configuration in which the number is reduced as much as possible.

本発明に係る貯湯式給湯機は、水を加熱して湯を生成可能な加熱手段と、湯水を貯留可能な貯湯タンクと、被加熱物と熱源水とを熱交換させることにより被加熱物を加熱する利用側熱交換器と、貯湯タンクの上部領域から取り出された湯を熱源水として利用側熱交換器に送り、利用側熱交換器を通過した熱源水を貯湯タンクの上部領域に流入させる熱源水上部戻し運転を行う手段と、貯湯タンクの上部領域から取り出された湯を熱源水として利用側熱交換器に送り、利用側熱交換器を通過した熱源水を貯湯タンクの下部領域に流入させる熱源水下部戻し運転を行う手段と、熱源水上部戻し運転を実行して被加熱物を加熱する場合の加熱能力を、熱源水下部戻し運転を実行して被加熱物を加熱する場合の加熱能力より低くするように制限する制御手段と、を備え、熱源水上部戻し運転において利用側熱交換器を通過した熱源水が貯湯タンクの上部領域に流入する第一上部口と、熱源水上部戻し運転において貯湯タンクの上部領域から熱源水を取り出す第二上部口と、熱源水下部戻し運転において利用側熱交換器を通過した熱源水が貯湯タンクの下部領域に流入する下部口とが設けられ、利用側熱交換器を通過した熱源水を貯湯タンク内に回収する回収口は、第一上部口と下部口との二つのみであり、第一上部口と第二上部口とが同じ高さの位置に設けられているか、または、第一上部口が第二上部口より高い位置に設けられているものである。
The hot water storage type hot water supply apparatus according to the present invention heats water to generate hot water, a hot water storage tank capable of storing hot water, and the object to be heated by exchanging heat between the heated object and the heat source water. The heating side heat exchanger to be heated and the hot water taken out from the upper area of the hot water storage tank are sent to the usage side heat exchanger as heat source water, and the heat source water that has passed through the usage side heat exchanger is caused to flow into the upper area of the hot water storage tank. The heat source water upper return operation and the hot water extracted from the upper area of the hot water storage tank are sent to the use side heat exchanger as heat source water, and the heat source water that has passed through the use side heat exchanger flows into the lower area of the hot water storage tank The means for performing the heat source water lower return operation, the heating capacity when heating the heated object by performing the heat source water upper returning operation, and the heating when performing the heat source water lower returning operation to heat the heated object System to limit to lower than ability And means, the heat source from the upper region of the hot water storage tank in a first upper port, back heat source water upper operating the heat source water having passed through the utilization side heat exchanger in the heat source water upper return operation flows into the upper region of the hot water storage tank A heat source that is provided with a second upper port for taking out water and a lower port through which heat source water that has passed through the use side heat exchanger flows into the lower region of the hot water storage tank in the heat source water lower return operation, and has passed through the use side heat exchanger There are only two recovery ports, a first upper port and a lower port, for collecting water in the hot water storage tank, and the first upper port and the second upper port are provided at the same height, or The first upper port is provided at a position higher than the second upper port .

本発明によれば、被加熱物を加熱するための利用側熱交換器から貯湯タンクに戻る戻り熱源水を貯湯タンク内に回収する回収口の数をできるだけ減らした低コストの装置構成で、エネルギー効率を向上することが可能となる。また、被加熱物を加熱する加熱動作の実行中または実行後に給湯動作を行った場合にも、給湯温度の変動などを確実に抑制することができる。 According to the present invention, the energy consumption can be reduced with a low-cost apparatus configuration in which the number of recovery ports for recovering the heat source water returning to the hot water storage tank from the use side heat exchanger for heating the object to be heated is reduced as much as possible. Efficiency can be improved. Further, even when the hot water supply operation is performed during or after the execution of the heating operation for heating the object to be heated, fluctuations in the hot water temperature can be reliably suppressed.

本発明の実施の形態１の貯湯式給湯機を示す構成図である。It is a block diagram which shows the hot water storage type water heater of Embodiment 1 of this invention. 本発明の実施の形態１の貯湯式給湯機の制御部が浴槽加熱動作時に実行する制御動作を示すフローチャートである。It is a flowchart which shows the control operation which the control part of the hot water storage type water heater of Embodiment 1 of this invention performs at the time of bathtub heating operation | movement. 本発明の実施の形態２の貯湯式給湯機の制御部が浴槽加熱動作時に実行する制御動作を示すフローチャートである。It is a flowchart which shows the control operation which the control part of the hot water storage type water heater of Embodiment 2 of this invention performs at the time of bathtub heating operation | movement.

以下、図面を参照して本発明の実施の形態について説明する。なお、各図において共通する要素には、同一の符号を付して、重複する説明を省略する。 Embodiments of the present invention will be described below with reference to the drawings. In addition, the same code | symbol is attached | subjected to the element which is common in each figure, and the overlapping description is abbreviate | omitted.

実施の形態１．
図１は、本発明の実施の形態１の貯湯式給湯機を示す構成図である。図１に示す本実施形態の貯湯式給湯機は、ヒートポンプユニット３１と、貯湯タンクユニット３２とを備えている。ヒートポンプユニット３１と、貯湯タンクユニット３２とは、ヒートポンプ入口配管７と、ヒートポンプ出口配管８と、電気配線（図示せず）とを介して接続されている。貯湯タンクユニット３２には、湯水を貯留する貯湯タンク１と、熱源循環ポンプ２と、浴槽循環ポンプ３と、追焚熱交換器１３（利用側熱交換器）と、流路切替手段としての第１の三方弁１４、第２の三方弁１５および四方弁１６と、湯水を混合して給湯温度を調節するための混合弁１７と、制御部２１（制御手段）とが搭載されている。ヒートポンプユニット３１および貯湯タンクユニット３２が備える各種の弁類、ポンプ類等の作動は、これらと電気的に接続された制御部２１により制御される。 Embodiment 1 FIG.
FIG. 1 is a configuration diagram illustrating a hot water storage type water heater according to Embodiment 1 of the present invention. The hot water storage type water heater of the present embodiment shown in FIG. 1 includes a heat pump unit 31 and a hot water storage tank unit 32. The heat pump unit 31 and the hot water storage tank unit 32 are connected via a heat pump inlet pipe 7, a heat pump outlet pipe 8, and electrical wiring (not shown). The hot water storage tank unit 32 includes a hot water storage tank 1 for storing hot water, a heat source circulation pump 2, a bathtub circulation pump 3, a memorial heat exchanger 13 (use side heat exchanger), and a first as a flow path switching means. The first three-way valve 14, the second three-way valve 15, and the four-way valve 16, a mixing valve 17 for mixing hot water and adjusting hot water supply temperature, and a control unit 21 (control means) are mounted. The operations of various valves, pumps, and the like provided in the heat pump unit 31 and the hot water storage tank unit 32 are controlled by the control unit 21 electrically connected thereto.

ヒートポンプユニット３１は、貯湯タンクユニット３２から導かれた水を加熱する（沸き上げる）ための加熱手段として機能するものである。ヒートポンプユニット３１は、圧縮機４１、加熱熱交換器４２、膨張弁４３および吸熱熱交換器４４を冷媒循環配管にて環状に接続した冷凍サイクル（ヒートポンプサイクル）を搭載している。加熱熱交換器４２は、圧縮機４１から流れる高温の冷媒と、ヒートポンプ入口配管７から流入する水との間で熱交換する。吸熱熱交換器側送風ファン４５は、吸熱熱交換器４４で空気と冷媒とを熱交換をさせるために送風を行う。 The heat pump unit 31 functions as a heating means for heating (boiling up) the water guided from the hot water storage tank unit 32. The heat pump unit 31 is equipped with a refrigeration cycle (heat pump cycle) in which a compressor 41, a heating heat exchanger 42, an expansion valve 43, and an endothermic heat exchanger 44 are connected in a ring shape with a refrigerant circulation pipe. The heating heat exchanger 42 exchanges heat between the high-temperature refrigerant flowing from the compressor 41 and water flowing from the heat pump inlet pipe 7. The endothermic heat exchanger side blowing fan 45 blows air in order to exchange heat between the air and the refrigerant in the endothermic heat exchanger 44.

貯湯タンク１は、略円筒形状のものが好ましく用いられる。貯湯タンク１の下部領域（中間より下側の領域）には、導入口１ａ、第一下部口１ｂおよび第二下部口１ｅが設けられている。貯湯タンク１の上部領域（中間より上側の領域）には、第一上部口１ｃおよび第二上部口１ｄが設けられている。 The hot water storage tank 1 preferably has a substantially cylindrical shape. An inlet 1a, a first lower port 1b, and a second lower port 1e are provided in a lower region (region below the middle) of the hot water tank 1. A first upper port 1c and a second upper port 1d are provided in the upper region (region above the middle) of the hot water storage tank 1.

貯湯タンクユニット３２には、外部の水道等の水源からの水を供給する給水配管４が接続されている。貯湯タンク１の導入口１ａには、給水配管４から分岐した給水分岐管５が接続されている。給水配管４、給水分岐管５を介して供給される低温水が導入口１ａから貯湯タンク１内に流入する。貯湯タンク１の第一下部口１ｂは、第１の三方弁１４が備える二つの流入ポートのうちの一方に連通するように接続されている。第１の三方弁１４の他方の流入ポートは、配管６を介して、追焚熱交換器１３の熱源側流路の出口に接続されている。第１の三方弁１４の流出ポートは、熱源循環ポンプ２の吸入口に連通するように接続されている。ヒートポンプ入口配管７は、熱源循環ポンプ２の吐出口と、加熱熱交換器４２の入水口とを接続している。 A water supply pipe 4 for supplying water from a water source such as an external water supply is connected to the hot water storage tank unit 32. A water supply branch pipe 5 branched from the water supply pipe 4 is connected to the introduction port 1 a of the hot water storage tank 1. Low temperature water supplied through the water supply pipe 4 and the water supply branch pipe 5 flows into the hot water storage tank 1 from the introduction port 1a. The first lower port 1b of the hot water storage tank 1 is connected so as to communicate with one of the two inflow ports provided in the first three-way valve 14. The other inflow port of the first three-way valve 14 is connected to the outlet of the heat source side passage of the additional heat exchanger 13 via the pipe 6. The outflow port of the first three-way valve 14 is connected to communicate with the suction port of the heat source circulation pump 2. The heat pump inlet pipe 7 connects the discharge port of the heat source circulation pump 2 and the water inlet of the heating heat exchanger 42.

ヒートポンプ出口配管８は、加熱熱交換器４２の出湯口と、四方弁１６が備える二つの流入ポートのうちの一方とを接続している。四方弁１６の他方の流入ポートには、熱源循環ポンプ２の吐出口付近のヒートポンプ入口配管７から分岐して延びた配管２４が接続されている。四方弁１６が備える二つの流出ポートのうちの一方は、配管９を介して、貯湯タンク１の第一上部口１ｃに接続されている。四方弁１６の他方の流出ポートは、配管２５を介して、貯湯タンク１の下部に設けられた第二下部口１ｅに接続されている。 The heat pump outlet pipe 8 connects the hot water outlet of the heating heat exchanger 42 and one of the two inflow ports provided in the four-way valve 16. The other inflow port of the four-way valve 16 is connected to a pipe 24 that branches off from the heat pump inlet pipe 7 near the discharge port of the heat source circulation pump 2. One of the two outflow ports provided in the four-way valve 16 is connected to the first upper port 1 c of the hot water storage tank 1 through the pipe 9. The other outflow port of the four-way valve 16 is connected to a second lower port 1 e provided at the lower part of the hot water storage tank 1 via a pipe 25.

貯湯タンク１の第二上部口１ｄは、配管１１を介して、第２の三方弁１５が備える二つの流入ポートのうちの一方に接続されている。第２の三方弁１５の他方の流入ポートには、配管９から分岐して延びた配管１０が接続されている。第２の三方弁１５の流出ポートは、追焚熱交換器１３の熱源側流路の入口に連通するように接続されている。 The second upper port 1 d of the hot water storage tank 1 is connected to one of the two inflow ports provided in the second three-way valve 15 via the pipe 11. The other inflow port of the second three-way valve 15 is connected to a pipe 10 extending from the pipe 9. The outflow port of the second three-way valve 15 is connected so as to communicate with the inlet of the heat source side flow path of the additional heat exchanger 13.

貯湯タンク１の第一上部口１ｃと第二上部口１ｄとは、必ずしも同じ高さの位置に設けられていなくても良い。第一上部口１ｃが第二上部口１ｄより高い位置に設けられていても良いし、その逆でも良い。また、図示の構成では、貯湯タンク１の第二下部口１ｅが第一下部口１ｂより高い位置に設けられているが、この逆でも良いし、第一下部口１ｂと第二下部口１ｅとが同じ高さに設けられていても良い。 The first upper port 1c and the second upper port 1d of the hot water storage tank 1 do not necessarily have to be provided at the same height. The first upper port 1c may be provided at a position higher than the second upper port 1d, or vice versa. Further, in the illustrated configuration, the second lower port 1e of the hot water storage tank 1 is provided at a position higher than the first lower port 1b, but this may be reversed, or the first lower port 1b and the second lower port 1e may be provided at the same height.

混合弁１７には、給水配管４と、配管１０から分岐して延びた配管１２と、給湯配管４９とが接続されている。混合弁１７は、貯湯タンク１の第一上部口１ｃから取り出されて配管９，１０および１２を通って供給される湯と、給水配管４から供給される水とを任意の割合で混合し、温度調節できるように構成されている。混合弁１７で混合されて温度調節された湯は、給湯配管４９を通って、例えばシャワー、蛇口、浴槽１９等の給湯先に供給される。なお、混合弁１７を複数設けても良い。 A water supply pipe 4, a pipe 12 branched and extending from the pipe 10, and a hot water supply pipe 49 are connected to the mixing valve 17. The mixing valve 17 mixes hot water taken out from the first upper port 1c of the hot water storage tank 1 and supplied through the pipes 9, 10 and 12 with water supplied from the water supply pipe 4 at an arbitrary ratio. The temperature can be adjusted. Hot water mixed at the mixing valve 17 and adjusted in temperature is supplied to a hot water supply destination such as a shower, a faucet, and a bathtub 19 through a hot water supply pipe 49. A plurality of mixing valves 17 may be provided.

追焚熱交換器１３の浴槽水出口は、配管２２を介して浴槽１９に接続されている。追焚熱交換器１３の浴槽水入口は、配管２３を介して浴槽１９に接続されている。配管２３の途中には、浴槽循環ポンプ３（被加熱物循環手段）が設置されている。浴槽１９の保温または昇温を行う場合には、浴槽循環ポンプ３が運転されることにより、浴槽１９内の浴槽水が、配管２３、追焚熱交換器１３、配管２２を通って浴槽１９に戻る経路で循環する。 The bathtub water outlet of the memory heat exchanger 13 is connected to the bathtub 19 via the pipe 22. The bath water inlet of the memorial heat exchanger 13 is connected to the bath 19 via a pipe 23. In the middle of the pipe 23, a bathtub circulation pump 3 (a heated object circulation means) is installed. When the bathtub 19 is kept warm or heated, the bathtub circulation pump 3 is operated, so that the bathtub water in the bathtub 19 passes to the bathtub 19 through the pipe 23, the additional heat exchanger 13, and the pipe 22. Cycle on the return path.

貯湯タンク１には、貯湯タンク１内の湯水の高さ方向の温度分布を検出するため、複数の貯湯温度センサ４７が互いに異なる高さ位置に取り付けられている。制御部２１は、これらの貯湯温度センサ４７により検出された貯湯タンク１内の高さ方向の温度分布に基づいて、貯湯タンク１内の貯湯量または蓄熱量を算出することができる。 A plurality of hot water storage temperature sensors 47 are attached to the hot water storage tank 1 at different height positions in order to detect the temperature distribution in the height direction of the hot water in the hot water storage tank 1. The control unit 21 can calculate the amount of stored hot water or the amount of heat stored in the hot water storage tank 1 based on the temperature distribution in the height direction in the hot water storage tank 1 detected by the hot water storage temperature sensor 47.

制御部２１は、ユーザーインターフェース装置（本実施形態では、例えば浴室や台所の壁等に設置されるリモコン装置２０とする。）と相互に通信可能に接続されている。リモコン装置２０には、例えば液晶表示装置、有機ＥＬ表示装置等で構成される表示部、ユーザーが操作可能な操作部、音声ガイダンスやメロディー等を発生可能なスピーカー等が設けられている。リモコン装置２０の表示部には、貯湯タンク１内に貯えられている湯の温度や貯湯量、給湯温度、時刻、沸き上げモードなどの情報が表示可能になっている。ユーザーは、リモコン装置２０に設けられた操作部を操作することにより、給湯温度や、浴槽１９に張る湯（浴槽水）の温度、自動湯張り、自動浴槽保温、浴槽昇温動作（通常および急速）、沸き上げモードなどの設定を行うことができる。 The control unit 21 is connected to a user interface device (in this embodiment, for example, a remote control device 20 installed on a bathroom or kitchen wall) so as to be able to communicate with each other. The remote control device 20 is provided with a display unit composed of, for example, a liquid crystal display device, an organic EL display device, an operation unit that can be operated by the user, a speaker that can generate voice guidance, a melody, and the like. On the display unit of the remote control device 20, information such as the temperature of the hot water stored in the hot water storage tank 1, the amount of hot water stored, the hot water supply temperature, the time, and the heating mode can be displayed. The user operates the operation unit provided on the remote control device 20, so that the hot water supply temperature, the temperature of hot water (tub water) applied to the bathtub 19, automatic hot water filling, automatic bath warming, bath temperature rising operation (normal and rapid) ), Setting the boiling mode and so on.

ヒートポンプユニット３１を利用して貯湯タンク１内の水を沸き上げる沸き上げ運転時には、第１の三方弁１４が貯湯タンク１の第一下部口１ｂと熱源循環ポンプ２の吸入口とを連通させる状態に制御され、四方弁１６がヒートポンプ出口配管８と配管９とを連通させる状態に制御されることで沸き上げ回路が形成され、熱源循環ポンプ２およびヒートポンプユニット３１が運転される。この沸き上げ運転時には、貯湯タンク１の第一下部口１ｂから流出する水は、第１の三方弁１４、熱源循環ポンプ２、ヒートポンプ入口配管７を経由してヒートポンプユニット３１に導かれ、加熱熱交換器４２において加熱されて高温水（湯）となり、ヒートポンプ出口配管８、四方弁１６、配管９を経由して、貯湯タンク１の第一上部口１ｃから貯湯タンク１内に流入し貯えられる。このような沸き上げ運転が実行されることで、貯湯タンク１の内部では、上層部から高温水が貯えられていき、この高温水層が徐々に厚くなっていき、貯湯温度センサ４７により把握される貯湯タンク１内の貯湯量または蓄熱量が所定量を超えると、沸き上げ運転が停止される。 At the time of the boiling operation for boiling water in the hot water storage tank 1 using the heat pump unit 31, the first three-way valve 14 communicates the first lower port 1b of the hot water storage tank 1 with the suction port of the heat source circulation pump 2. When the four-way valve 16 is controlled to communicate with the heat pump outlet pipe 8 and the pipe 9, a boiling circuit is formed, and the heat source circulation pump 2 and the heat pump unit 31 are operated. During this boiling operation, the water flowing out from the first lower port 1b of the hot water storage tank 1 is led to the heat pump unit 31 via the first three-way valve 14, the heat source circulation pump 2, and the heat pump inlet pipe 7, and heated. It is heated in the heat exchanger 42 to become high-temperature water (hot water), and flows into the hot water storage tank 1 from the first upper port 1c of the hot water storage tank 1 through the heat pump outlet pipe 8, the four-way valve 16, and the pipe 9, and is stored. . By performing such boiling operation, high-temperature water is stored in the hot water storage tank 1 from the upper layer portion, and this high-temperature water layer gradually becomes thick and is grasped by the hot water storage temperature sensor 47. When the amount of stored hot water or the amount of stored heat in the hot water storage tank 1 exceeds a predetermined amount, the boiling operation is stopped.

本実施形態の貯湯式給湯機は、浴槽１９の保温または昇温するための浴槽加熱動作を行う場合に、貯湯タンク１の上部領域から取り出した湯を熱源水として追焚熱交換器１３に循環させる運転方法として、追焚熱交換器１３での熱交換により温度低下して中温となった熱源水を貯湯タンク１の上部領域に戻す熱源水上部戻し運転と、追焚熱交換器１３での熱交換により温度低下して中温となった熱源水を貯湯タンク１の下部領域に戻す熱源水下部戻し運転とを、選択的に実行可能になっている。熱源水上部戻し運転による浴槽加熱動作時には、第１の三方弁１４が配管６と熱源循環ポンプ２の吸入口とを連通させる状態に制御され、第２の三方弁１５が配管１１と追焚熱交換器１３の熱源側流路の入口とを連通させる状態（図１中の矢印Ａ方向）に制御され、四方弁１６が配管２４と配管９とを連通させる状態（図１中の矢印Ａ方向）に制御されることで熱源水上部戻し回路が形成され、熱源循環ポンプ２および浴槽循環ポンプ３が運転される。この熱源水上部戻し運転による浴槽加熱動作時には、貯湯タンク１の第二上部口１ｄから高温の熱源水が流出し、配管１１、第２の三方弁１５を経由して追焚熱交換器１３に導かれ、浴槽水との熱交換により温度低下し、中温の熱源水となる。この中温の熱源水は、配管６、第１の三方弁１４、熱源循環ポンプ２、ヒートポンプ入口配管７、配管２４、四方弁１６、配管９を経由して第一上部口１ｃから貯湯タンク１内に流入する。 The hot water storage type water heater of the present embodiment circulates in the hot water exchanger 13 using hot water taken out from the upper region of the hot water storage tank 1 as a heat source water when performing a bath heating operation for keeping the bath 19 warm or raising the temperature. As the operation method to be performed, the heat source water upper return operation for returning the heat source water whose temperature has been lowered to the intermediate temperature due to the heat exchange in the additional heat exchanger 13 to the upper region of the hot water storage tank 1, and the additional heat exchanger 13 A heat source water lower return operation for returning the heat source water whose temperature has been lowered to the intermediate temperature by heat exchange to the lower region of the hot water storage tank 1 can be selectively executed. At the time of the bathtub heating operation by the heat source water upper return operation, the first three-way valve 14 is controlled to communicate with the pipe 6 and the suction port of the heat source circulation pump 2, and the second three-way valve 15 is connected to the pipe 11 and additional heat. The state is controlled to communicate with the inlet of the heat source side flow path of the exchanger 13 (in the direction of arrow A in FIG. 1), and the four-way valve 16 communicates with the piping 24 and the piping 9 (in the direction of arrow A in FIG. 1). ), The heat source water upper return circuit is formed, and the heat source circulation pump 2 and the bathtub circulation pump 3 are operated. At the time of the bathtub heating operation by the heat source water upper return operation, high temperature heat source water flows out from the second upper port 1d of the hot water storage tank 1 and passes through the pipe 11 and the second three-way valve 15 to the memorial heat exchanger 13. The temperature is lowered by the heat exchange with the bath water and becomes a medium temperature heat source water. This intermediate temperature heat source water is supplied from the first upper port 1c into the hot water storage tank 1 via the pipe 6, the first three-way valve 14, the heat source circulation pump 2, the heat pump inlet pipe 7, the pipe 24, the four-way valve 16, and the pipe 9. Flow into.

一方、熱源水下部戻し運転による浴槽加熱動作時には、第１の三方弁１４が配管６と熱源循環ポンプ２の吸入口とを連通させる状態に制御され、第２の三方弁１５が配管１１と追焚熱交換器１３の熱源側流路の入口とを連通させる状態に制御され、四方弁１６が配管２４と配管２５とを連通させる状態（図１中の矢印Ｂ方向）に制御されることで熱源水下部戻し回路が形成され、熱源循環ポンプ２および浴槽循環ポンプ３が運転される。この熱源水下部戻し運転による浴槽加熱動作時には、貯湯タンク１の第二上部口１ｄから高温の熱源水が流出し、配管１１、第２の三方弁１５を経由して追焚熱交換器１３に導かれ、浴槽水との熱交換により温度低下し、中温の熱源水になる。この中温の熱源水は、配管６、第１の三方弁１４、熱源循環ポンプ２、ヒートポンプ入口配管７、配管２４、四方弁１６、配管２５を経由して第二下部口１ｅから貯湯タンク１内に流入する。 On the other hand, during the bathtub heating operation by the heat source water lower return operation, the first three-way valve 14 is controlled to communicate with the pipe 6 and the suction port of the heat source circulation pump 2, and the second three-way valve 15 is added to the pipe 11. It is controlled so that the inlet of the heat source side flow path of the heat exchanger 13 is communicated, and the four-way valve 16 is controlled so as to communicate the pipe 24 and the pipe 25 (in the direction of arrow B in FIG. 1). A heat source water lower return circuit is formed, and the heat source circulation pump 2 and the bathtub circulation pump 3 are operated. At the time of the bathtub heating operation by this heat source water lower return operation, high temperature heat source water flows out from the second upper port 1d of the hot water storage tank 1 and passes through the pipe 11 and the second three-way valve 15 to the memorial heat exchanger 13. The temperature is lowered by heat exchange with the bath water, and becomes medium temperature heat source water. This medium temperature heat source water is supplied from the second lower port 1e to the hot water storage tank 1 via the pipe 6, the first three-way valve 14, the heat source circulation pump 2, the heat pump inlet pipe 7, the pipe 24, the four-way valve 16, and the pipe 25. Flow into.

本実施形態では、制御部２１は、浴槽加熱動作を行う場合に、貯湯式給湯機の状態（例えば、貯湯タンク１内の貯湯温度あるいは蓄熱量）やリモコン装置２０に入力されるユーザーの意向等に応じて、所定の規則に基づき、熱源水上部戻し運転と、熱源水下部戻し運転との何れかを選択して実施する。例えば、制御部２１は、貯湯タンク１内の上部領域の貯湯温度が十分に高い場合には、熱源水上部戻し運転を選択することが好ましい。また、制御部２１は、短時間で浴槽加熱を完了すること（急速の浴槽昇温動作）をユーザーが希望している場合には、熱源水下部戻し運転を選択することが好ましい。逆に、浴槽加熱の完了までに時間が掛かることをユーザーが許容している場合には、制御部２１は、熱源水上部戻し運転を選択することが好ましい。 In the present embodiment, the control unit 21 performs the bath heating operation, such as the state of the hot water storage hot water heater (for example, the hot water storage temperature or the heat storage amount in the hot water storage tank 1), the user's intention input to the remote control device 20, and the like. Accordingly, based on a predetermined rule, either the heat source water upper return operation or the heat source water lower return operation is selected and executed. For example, when the hot water storage temperature in the upper region in the hot water storage tank 1 is sufficiently high, the control unit 21 preferably selects the heat source water upper return operation. Moreover, it is preferable that the control part 21 selects heat source water lower part return operation, when the user desires to complete bathtub heating (rapid bathtub temperature rising operation) in a short time. On the contrary, when the user has allowed time to complete the bath heating, the control unit 21 preferably selects the heat source water upper return operation.

浴槽加熱動作の実行中に追焚熱交換器１３から戻る中温の熱源水（以下、「戻り熱源水」と称する）は、例えば４０℃程度の温度を有しており、給湯に利用可能な温度（例えば４５℃）よりは温度が低いとしても、給水配管４から供給される低温水よりは温度が十分に高く、熱量を有している。熱源水上部戻し運転を実施した場合には、この戻り熱源水が貯湯タンク１の上部領域に流入し、貯湯タンク１内の上部領域に貯えられている高温の湯と混合する。その混合した湯は、給湯に利用可能な温度以上になるので、混合弁１７から給湯先へ給湯可能となる。このように、熱源水上部戻し運転によれば、戻り熱源水が持つ熱量を給湯先への給湯に有効に再利用することが可能となるので、エネルギー使用効率を向上することができる。また、熱源水上部戻し運転では、戻り熱源水を貯湯タンク１の下部領域に流入させないため、貯湯タンク１の下部領域に貯留された低温水の温度上昇を確実に抑制することができる。一般にヒートポンプユニット３１は、流入する水の温度が低いほど効率の良い運転ができる。熱源水上部戻し運転によれば、沸き上げ運転の際に貯湯タンク１からヒートポンプユニット３１への入水温度を低く維持することが可能となり、沸き上げ運転の効率を高くすることができる。 Medium temperature heat source water (hereinafter referred to as “return heat source water”) returning from the memory heat exchanger 13 during execution of the bath heating operation has a temperature of about 40 ° C., for example, and is a temperature that can be used for hot water supply. Even if the temperature is lower than (for example, 45 ° C.), the temperature is sufficiently higher than the low-temperature water supplied from the water supply pipe 4 and has a heat quantity. When the heat source water upper return operation is performed, the return heat source water flows into the upper area of the hot water storage tank 1 and mixes with the hot water stored in the upper area of the hot water storage tank 1. Since the mixed hot water has a temperature higher than that available for hot water supply, the hot water can be supplied from the mixing valve 17 to the hot water supply destination. In this way, according to the heat source water upper return operation, the amount of heat of the return heat source water can be effectively reused for hot water supply to the hot water supply destination, so that energy use efficiency can be improved. Further, in the heat source water upper return operation, the return heat source water is not allowed to flow into the lower region of the hot water storage tank 1, so that the temperature rise of the low temperature water stored in the lower region of the hot water storage tank 1 can be reliably suppressed. In general, the heat pump unit 31 can operate more efficiently as the temperature of the inflowing water is lower. According to the heat source water upper return operation, it is possible to keep the water temperature from the hot water storage tank 1 to the heat pump unit 31 low during the boiling operation, and the efficiency of the boiling operation can be increased.

その一方で、熱源水上部戻し運転を行うと、戻り熱源水が貯湯タンク１内の上部領域に流入することにより、貯湯タンク１内の上部領域に貯えられている湯の温度が低下する。このため、熱源水上部戻し運転による浴槽加熱動作の実行中あるいは実行後に混合弁１７から給湯先へ給湯した場合に、給湯温度が不安定になったり、給湯温度がユーザーの設定した設定温度（以下、「目標温度」と称する）を下回ったりする可能性がある。 On the other hand, when the heat source water upper return operation is performed, the return heat source water flows into the upper region in the hot water storage tank 1, thereby lowering the temperature of the hot water stored in the upper region in the hot water storage tank 1. For this reason, when hot water is supplied from the mixing valve 17 to the hot water supply destination during or after execution of the bathtub heating operation by the heat source water upper return operation, the hot water temperature becomes unstable, or the hot water temperature is set to the set temperature set by the user (hereinafter referred to as the hot water temperature). , Referred to as “target temperature”).

これに対し、熱源水下部戻し運転による浴槽加熱動作の場合、追焚熱交換器１３からの戻り熱源水が貯湯タンク１の下部領域に流入し、貯湯タンク１内の下部領域に貯えられている低温水と混合する。このような熱源水下部戻し運転による浴槽加熱動作では、貯湯タンク１内の上部領域に貯えられている湯の温度の低下を回避することができる。よって、熱源水下部戻し運転による浴槽加熱動作の実行中あるいは実行後に混合弁１７から給湯先へ給湯した場合にも、給湯温度が不安定になったり、給湯温度が目標温度を下回ったりすることを防止することができる。しかしながら、熱源水下部戻し運転による浴槽加熱動作では、戻り熱源水が貯湯タンク１の下部領域に流入することにより、貯湯タンク１の下部領域に貯留されている水の温度が上昇する。このため、熱源水下部戻し運転による浴槽加熱動作を行った場合には、沸き上げ運転時にヒートポンプユニット３１へ流入する水の温度が高くなり、ヒートポンプユニット３１の効率の低下を招く。 On the other hand, in the case of the bathtub heating operation by the heat source water lower return operation, the return heat source water from the additional heat exchanger 13 flows into the lower region of the hot water storage tank 1 and is stored in the lower region in the hot water storage tank 1. Mix with cold water. In such a bathtub heating operation by the heat source water lower return operation, a decrease in the temperature of the hot water stored in the upper region in the hot water storage tank 1 can be avoided. Therefore, even when hot water is supplied from the mixing valve 17 to the hot water supply destination during or after the bathtub heating operation by the heat source water lower return operation, the hot water temperature becomes unstable or the hot water temperature falls below the target temperature. Can be prevented. However, in the bathtub heating operation by the heat source water lower return operation, the temperature of the water stored in the lower region of the hot water tank 1 rises as the return heat source water flows into the lower region of the hot water tank 1. For this reason, when the bathtub heating operation by the heat source water lower return operation is performed, the temperature of the water flowing into the heat pump unit 31 at the time of the boiling operation becomes high, and the efficiency of the heat pump unit 31 is reduced.

本実施形態の貯湯式給湯機では、上述した事項に鑑み、熱源水上部戻し運転による浴槽加熱動作を行った後に混合弁１７から給湯先へ給湯した場合に、給湯温度が不安定になったり、給湯温度が目標温度を下回ったりすることを確実に防止するため、以下のような制御を行う。すなわち、制御部２１は、熱源水上部戻し運転による浴槽加熱動作を行う場合の加熱能力を、熱源水下部戻し運転による浴槽加熱動作を行う場合の加熱能力より低くするように制限する。ここで、加熱能力とは、時間当たりの加熱量、または通算の加熱量である。本実施形態によれば、熱源水上部戻し運転による浴槽加熱動作を行う場合に、加熱能力を制限することにより、貯湯タンク１内の上部領域に貯えられている湯の温度が急激に低下することを確実に防止することができる。その結果、熱源水上部戻し運転による浴槽加熱動作の実行中あるいは実行後に混合弁１７から給湯先へ給湯した場合にも、給湯温度が不安定になったり、給湯温度が目標温度を下回ったりすることを確実に抑制することができる。 In the hot water storage type water heater of the present embodiment, in view of the above-described matters, when hot water is supplied from the mixing valve 17 to the hot water destination after performing the bathtub heating operation by the heat source water upper return operation, the hot water temperature becomes unstable, In order to reliably prevent the hot water supply temperature from falling below the target temperature, the following control is performed. That is, the control part 21 restrict | limits the heating capability in the case of performing the bathtub heating operation by the heat source water upper part return operation to be lower than the heating capability in the case of performing the bathtub heating operation by the heat source water lower part return operation. Here, the heating capacity is the heating amount per hour or the total heating amount. According to this embodiment, when performing the bathtub heating operation by the heat source water upper return operation, the temperature of the hot water stored in the upper region in the hot water storage tank 1 is rapidly reduced by limiting the heating capacity. Can be reliably prevented. As a result, even when hot water is supplied from the mixing valve 17 to the hot water supply destination during or after the bathtub heating operation by the heat source water upper return operation, the hot water temperature becomes unstable or the hot water temperature falls below the target temperature. Can be reliably suppressed.

図２は、本実施の形態１の貯湯式給湯機の制御部２１が浴槽加熱動作の実行時に行う制御動作を示すフローチャートである。図２のフローチャートのステップＳ５１で浴槽加熱動作を開始すると、制御部２１は、熱源水を循環させる方法として熱源水上部戻し運転が選択されているか否かを判断する（ステップＳ５２）。その結果、熱源水上部戻し運転が選択されていない場合、すなわち熱源水下部戻し運転が選択されている場合には、熱源循環ポンプ２を予め設定された規定回転数で駆動する（ステップＳ５４）。その後、処理を終了する（ステップＳ５５）。上記規定回転数は、追焚熱交換器１３に循環する熱源水の循環流量が、規定の流量となる回転数である。このようにして追焚熱交換器１３に規定流量の熱源水が循環することにより、予め設定された規定の加熱能力が追焚熱交換器１３にて発揮される。 FIG. 2 is a flowchart illustrating a control operation performed by the control unit 21 of the hot water storage type hot water heater according to the first embodiment when the bathtub heating operation is performed. When the bathtub heating operation is started in step S51 of the flowchart of FIG. 2, the control unit 21 determines whether or not the heat source water upper return operation is selected as a method of circulating the heat source water (step S52). As a result, when the heat source water upper return operation is not selected, that is, when the heat source water lower return operation is selected, the heat source circulation pump 2 is driven at a preset specified rotational speed (step S54). Thereafter, the process is terminated (step S55). The specified rotational speed is a rotational speed at which the circulating flow rate of the heat source water circulating in the memory heat exchanger 13 becomes a specified flow rate. In this way, the heat source water having a predetermined flow rate circulates in the memory heat exchanger 13, so that a predetermined heating capacity set in advance is exhibited in the memory heat exchanger 13.

一方、ステップＳ５２で、熱源水上部戻し運転が選択されている場合には、熱源循環ポンプ２を、上記規定回転数より低い回転数として予め設定された制限回転数で駆動する（ステップＳ５３）。その後、処理を終了する（ステップＳ５５）。これにより、追焚熱交換器１３には、上記規定流量より低い所定の制限流量で熱源水が循環する。その結果、上記規定の加熱能力より低い、制限された加熱能力が追焚熱交換器１３にて発揮される。上記制限流量は、戻り熱源水がその流量で貯湯タンク１内の上部領域に流入しても、貯湯タンク１内の上部領域に貯えられている湯の温度が急激に低下することのないような値として設定されている。本実施形態では、このようにして熱源水上部戻し運転時の加熱能力を熱源水の循環流量によって制限することにより、貯湯タンク１内の上部領域に貯えられている湯の温度が急激に低下することを確実に防止することができる。その結果、熱源水上部戻し運転による浴槽加熱動作の実行中あるいは実行後に混合弁１７から給湯先へ給湯した場合にも、給湯温度が不安定になったり、給湯温度が目標温度を下回ったりすることを確実に抑制することができる。 On the other hand, when the heat source water upper return operation is selected in step S52, the heat source circulation pump 2 is driven at a preset rotational speed that is preset as a rotational speed lower than the specified rotational speed (step S53). Thereafter, the process is terminated (step S55). As a result, the heat source water is circulated in the remnant heat exchanger 13 at a predetermined limited flow rate lower than the specified flow rate. As a result, a limited heating capacity that is lower than the prescribed heating capacity is exhibited in the memory heat exchanger 13. The limit flow rate is such that even if the return heat source water flows into the upper region in the hot water storage tank 1 at that flow rate, the temperature of the hot water stored in the upper region in the hot water storage tank 1 does not drop rapidly. It is set as a value. In the present embodiment, the temperature of the hot water stored in the upper region in the hot water storage tank 1 is drastically lowered by limiting the heating capacity during the heat source water upper return operation in this way by the circulation flow rate of the heat source water. This can be surely prevented. As a result, even when hot water is supplied from the mixing valve 17 to the hot water supply destination during or after the bathtub heating operation by the heat source water upper return operation, the hot water temperature becomes unstable or the hot water temperature falls below the target temperature. Can be reliably suppressed.

なお、上述した実施の形態では、熱源水上部戻し運転時の加熱能力を、追焚熱交換器１３に循環する熱源水の循環流量によって制限しているが、熱源水上部戻し運転の運転継続時間（すなわち熱源循環ポンプ２の運転継続時間）によって加熱能力を制限しても良い。すなわち、熱源水上部戻し運転を行う場合の運転継続時間（すなわち熱源循環ポンプ２の運転継続時間）が、熱源水下部戻し運転を行う場合の運転継続時間（すなわち熱源循環ポンプ２の運転継続時間）より短くなるように制御しても良い。熱源水上部戻し運転の運転継続時間を短時間に制限することにより、貯湯タンク１内の上部領域に貯えられている湯の温度が急激に低下することを確実に抑制することができるので、上記と同様の効果が得られる。また、熱源水上部戻し運転時の加熱能力を、追焚熱交換器１３に循環する熱源水の循環流量と、運転継続時間との双方によって制限しても良い。 In the above-described embodiment, the heating capacity at the time of the heat source water upper return operation is limited by the circulation flow rate of the heat source water circulating to the additional heat exchanger 13, but the operation duration time of the heat source water upper return operation The heating capacity may be limited by (that is, the operation duration time of the heat source circulation pump 2). That is, the operation continuation time when performing the heat source water upper return operation (that is, the operation continuation time of the heat source circulation pump 2) is the operation continuation time when performing the heat source water lower return operation (that is, the operation continuation time of the heat source circulation pump 2). You may control so that it may become shorter. By limiting the operation continuation time of the heat source water upper return operation to a short time, the temperature of the hot water stored in the upper region in the hot water storage tank 1 can be reliably suppressed from decreasing rapidly. The same effect can be obtained. Moreover, you may restrict | limit the heating capability at the time of a heat source water upper return operation | movement with both the circulation flow rate of the heat source water circulated to the additional heat exchanger 13, and an operation continuation time.

以上説明した本実施形態の貯湯式給湯機によれば、浴槽加熱動作を行う方法として、戻り熱源水の熱量を有効に再利用することができ且つ沸き上げ運転時のヒートポンプユニット３１の効率も向上することのできる熱源水上部戻し運転を可能としたことにより、貯湯式給湯機の全体的なエネルギー効率を向上することができる。また、本実施形態の貯湯式給湯機では、追焚熱交換器１３から戻る戻り熱源水を貯湯タンク１内に回収する回収口の数が、第一上部口１ｃおよび第二下部口１ｅの二つで済む。このように、本実施形態によれば、追焚熱交換器１３から戻る戻り熱源水を貯湯タンク１内に回収する回収口の数が少ないため、貯湯タンク１の構造や配管構成を簡素化することができ、戻り熱源水を複数の回収口に分配するための流量制御弁も不要であるので、低コストの装置構成で、貯湯式給湯機のエネルギー効率を向上することができる。 According to the hot water storage type water heater of the present embodiment described above, the heat amount of the return heat source water can be effectively reused as a method for performing the bathtub heating operation, and the efficiency of the heat pump unit 31 during the boiling operation is also improved. By enabling the heat source water upper return operation that can be performed, the overall energy efficiency of the hot water storage type water heater can be improved. Further, in the hot water storage type hot water heater of the present embodiment, the number of recovery ports for recovering the return heat source water returning from the reheating heat exchanger 13 into the hot water storage tank 1 is two of the first upper port 1c and the second lower port 1e. It's enough. Thus, according to this embodiment, since the number of the recovery ports which collect | recover the return heat source water which returns from the memorial heat exchanger 13 in the hot water storage tank 1 is small, the structure and piping structure of the hot water storage tank 1 are simplified. In addition, since a flow rate control valve for distributing the return heat source water to the plurality of recovery ports is unnecessary, the energy efficiency of the hot water storage type hot water heater can be improved with a low-cost apparatus configuration.

なお、以上の説明では、貯湯タンク１から取り出した湯を熱源水として利用して浴槽水を加熱する浴槽加熱動作を行う場合について説明したが、本発明の貯湯式給湯機は、ヒートポンプユニット３１で加熱した湯を熱源水として追焚熱交換器１３に直接供給し、戻り熱源水をヒートポンプユニット３１に送って再加熱して再循環させることよって浴槽加熱動作を行う機能を兼ね備えていても良い。このようにしてヒートポンプユニット３１によって浴槽加熱動作を行う場合には、第１の三方弁１４が配管６と熱源循環ポンプ２の吸入口とを連通させる状態に制御され、第２の三方弁１５が配管１０と追焚熱交換器１３の熱源側流路の入口とを連通させる状態に制御され、四方弁１６がヒートポンプ出口配管８と配管９とを連通させる状態に制御され、ヒートポンプユニット３１の加熱熱交換器４２で加熱された熱源水が、ヒートポンプ出口配管８、四方弁１６、配管９、配管１０、第２の三方弁１５、追焚熱交換器１３、配管６、第１の三方弁１４、熱源循環ポンプ２、ヒートポンプ入口配管７、加熱熱交換器４２の順に循環する。 In addition, although the above description demonstrated the case where the bathtub heating operation | movement which heats bathtub water using the hot water taken out from the hot water storage tank 1 as heat source water was performed, the hot water storage type water heater of this invention is the heat pump unit 31. The heated hot water may be directly supplied to the reheating heat exchanger 13 as a heat source water, and the return heat source water may be sent to the heat pump unit 31 to be reheated and recirculated so as to perform a bathtub heating operation. When the bathtub heating operation is performed by the heat pump unit 31 in this way, the first three-way valve 14 is controlled to communicate with the pipe 6 and the suction port of the heat source circulation pump 2, and the second three-way valve 15 is The piping 10 is controlled to communicate with the inlet of the heat source side flow path of the heat exchanger 13, the four-way valve 16 is controlled to communicate with the heat pump outlet piping 8 and the piping 9, and the heat pump unit 31 is heated. The heat source water heated by the heat exchanger 42 is supplied from the heat pump outlet pipe 8, the four-way valve 16, the pipe 9, the pipe 10, the second three-way valve 15, the memory heat exchanger 13, the pipe 6, and the first three-way valve 14. The heat source circulation pump 2, the heat pump inlet pipe 7, and the heating heat exchanger 42 are circulated in this order.

また、本実施形態では、浴槽水を加熱する追焚熱交換器１３を利用側熱交換器とする構成を例に説明したが、本発明は、浴槽水以外の被加熱物（例えば、暖房用循環水）を加熱する利用側熱交換器を用いる貯湯式給湯機にも同様に適用可能である。 Moreover, although this embodiment demonstrated to the example the structure which uses the memorial heat exchanger 13 which heats bathtub water as a utilization side heat exchanger, this invention is a to-be-heated object other than bathtub water (for example, for heating) The present invention can be similarly applied to a hot water storage type water heater using a use side heat exchanger for heating (circulated water).

実施の形態２．
次に、図３を参照して、本発明の実施の形態２について説明するが、上述した実施の形態１との相違点を中心に説明し、同一部分または相当部分は同一符号を付し説明を省略する。本実施の形態２の貯湯式給湯機のハードウェア構成は、図１に示す実施の形態１の構成と同一であるので、説明を省略する。 Embodiment 2. FIG.
Next, a second embodiment of the present invention will be described with reference to FIG. 3. The description will focus on the differences from the first embodiment described above, and the same or corresponding parts will be denoted by the same reference numerals. Is omitted. The hardware configuration of the hot water storage type hot water heater of the second embodiment is the same as that of the first embodiment shown in FIG.

図３は、本実施の形態２の貯湯式給湯機の制御部２１が浴槽加熱動作の実行時に行う制御動作を示すフローチャートである。図３のフローチャートのステップＳ６１で浴槽加熱動作を開始すると、制御部２１は、熱源水を循環させる方法として熱源水上部戻し運転が選択されているか否かを判断する（ステップＳ６２）。その結果、熱源水上部戻し運転が選択されていない場合、すなわち熱源水下部戻し運転が選択されている場合には、浴槽循環ポンプ３を予め設定された浴槽ポンプ用規定回転数で駆動し（ステップＳ６５）、熱源循環ポンプ２を予め設定された熱源ポンプ用規定回転数で駆動する（ステップＳ６６）。その後、処理を終了する（ステップＳ６７）。 FIG. 3 is a flowchart illustrating a control operation performed by the control unit 21 of the hot water storage hot water supply apparatus according to the second embodiment when the bathtub heating operation is performed. When the bathtub heating operation is started in step S61 of the flowchart of FIG. 3, the control unit 21 determines whether or not the heat source water upper return operation is selected as a method of circulating the heat source water (step S62). As a result, when the heat source water upper return operation is not selected, that is, when the heat source water lower return operation is selected, the bathtub circulation pump 3 is driven at a preset predetermined number of rotations for the bathtub pump (step In step S65, the heat source circulation pump 2 is driven at a preset heat source pump rotation speed (step S66). Thereafter, the process is terminated (step S67).

一方、ステップＳ６２で、熱源水上部戻し運転が選択されている場合には、上記浴槽ポンプ用規定回転数より低い回転数として予め設定された第一の制限回転数で浴槽循環ポンプ３を駆動し（ステップＳ６３）、上記熱源ポンプ用規定回転数より低い回転数として予め設定された第二の制限回転数で熱源循環ポンプ２を駆動する（ステップＳ６４）。その後、処理を終了する（ステップＳ６７）。 On the other hand, when the heat source water upper return operation is selected in step S62, the bathtub circulation pump 3 is driven at a first limited rotation speed set in advance as a rotation speed lower than the specified rotation speed for the bathtub pump. (Step S63), the heat source circulation pump 2 is driven at a second limited rotational speed set in advance as a rotational speed lower than the specified rotational speed for the heat source pump (Step S64). Thereafter, the process is terminated (step S67).

以上の制御により、本実施の形態２では、熱源水上部戻し運転時の熱源水の循環流量を熱源水下部戻し運転時の熱源水の循環流量より低く制限することに加え、熱源水上部戻し運転時の浴槽水の循環流量を熱源水下部戻し運転時の浴槽水の循環流量より低く制限することにより、熱源水上部戻し運転時の加熱能力を熱源水下部戻し運転時の加熱能力より低く制限する。このような本実施の形態２の制御によれば、熱源水上部戻し運転によって貯湯タンク１内の上部領域に貯えられている湯の温度が急激に低下することをより確実に防止することができる。その結果、熱源水上部戻し運転による浴槽加熱動作の実行中あるいは実行後に混合弁１７から給湯先へ給湯した場合にも、給湯温度が不安定になったり、給湯温度が目標温度を下回ったりすることをより確実に抑制することができる。 With the above control, in the second embodiment, in addition to limiting the circulation flow rate of the heat source water during the heat source water upper return operation to be lower than the circulation flow rate of the heat source water during the lower heat source water return operation, By limiting the circulating water flow rate of the bath water lower than the circulating water flow rate of the bath water during the lower return operation of the heat source water, the heating capacity during the upper return operation of the heat source water is limited to be lower than the heating capacity during the lower return operation of the heat source water. . According to such control of the second embodiment, it is possible to more reliably prevent the temperature of the hot water stored in the upper region in the hot water storage tank 1 from being rapidly lowered by the heat source water upper return operation. . As a result, even when hot water is supplied from the mixing valve 17 to the hot water supply destination during or after the bathtub heating operation by the heat source water upper return operation, the hot water temperature becomes unstable or the hot water temperature falls below the target temperature. Can be more reliably suppressed.

本実施の形態２では、熱源水上部戻し運転時の熱源水の循環流量および浴槽水の循環流量の双方を制限することによって熱源水上部戻し運転時の加熱能力を制限しているが、熱源水上部戻し運転時の浴槽水の循環流量のみを制限することによって熱源水上部戻し運転時の加熱能力を制限しても良い。また、浴槽水の循環流量を制限することに代えて、熱源水上部戻し運転を行う場合の浴槽水の循環継続時間（すなわち浴槽循環ポンプ３の運転継続時間）が、熱源水下部戻し運転を行う場合の浴槽水の循環継続時間（すなわち浴槽循環ポンプ３の運転継続時間）より短くなるように制御することにより、熱源水上部戻し運転時の加熱能力を制限しても良い。この制御によっても、同様の効果が得られる。 In Embodiment 2, the heating capacity during the heat source water upper return operation is limited by limiting both the circulation flow rate of the heat source water during the heat source water upper return operation and the circulation flow rate of the bath water. You may restrict | limit the heating capability at the time of heat source water upper return operation by restrict | limiting only the circulation flow rate of the bathtub water at the time of partial return operation. Moreover, instead of limiting the circulation flow rate of the bath water, the circulation time of the bath water when the heat source water upper return operation is performed (that is, the operation duration time of the bath circulation pump 3) performs the lower heat source water return operation. In this case, the heating capacity during the heat source water upper return operation may be limited by controlling so as to be shorter than the circulation time of the bathtub water (that is, the operation continuation time of the bathtub circulation pump 3). The same effect can be obtained by this control.

１貯湯タンク、１ａ導入口、１ｂ第一下部口、１ｃ第一上部口、
１ｄ第二上部口、１ｅ第二下部口、２熱源循環ポンプ、３浴槽循環ポンプ、
４給水配管、５給水分岐管、
６，９，１０，１１，１２，２２，２３，２４，２５配管、
７ヒートポンプ入口配管、８ヒートポンプ出口配管、１３追焚熱交換器、
１４第１の三方弁、１５第２の三方弁、１６四方弁、１７混合弁、１９浴槽、
２０リモコン装置、２１制御部、３１ヒートポンプユニット、
３２貯湯タンクユニット、４１圧縮機、４２加熱熱交換器、４３膨張弁、
４４吸熱熱交換器、４５吸熱熱交換器側送風ファン、４７貯湯温度センサ、
４９給湯配管 1 hot water storage tank, 1a introduction port, 1b first lower port, 1c first upper port,
1d second upper port, 1e second lower port, 2 heat source circulation pump, 3 bathtub circulation pump,
4 water supply pipe, 5 water supply branch pipe,
6, 9, 10, 11, 12, 22, 23, 24, 25 piping,
7 Heat pump inlet piping, 8 Heat pump outlet piping, 13 Memorial heat exchanger,
14 first three-way valve, 15 second three-way valve, 16 four-way valve, 17 mixing valve, 19 bathtub,
20 remote control device, 21 control unit, 31 heat pump unit,
32 hot water storage tank unit, 41 compressor, 42 heating heat exchanger, 43 expansion valve,
44 endothermic heat exchanger, 45 endothermic heat exchanger side blower fan, 47 hot water storage temperature sensor,
49 Hot water supply piping

Claims

Heating means capable of generating water by heating water;
A hot water storage tank capable of storing hot water,
A use side heat exchanger that heats the object to be heated by exchanging heat between the object to be heated and the heat source water;
The upper part of the heat source water that sends hot water taken out from the upper area of the hot water storage tank as the heat source water to the use side heat exchanger and allows the heat source water that has passed through the use side heat exchanger to flow into the upper area of the hot water storage tank Means for performing the return operation;
The lower part of the heat source water that sends hot water taken out from the upper area of the hot water storage tank as the heat source water to the use side heat exchanger and allows the heat source water that has passed through the use side heat exchanger to flow into the lower area of the hot water storage tank Means for performing the return operation;
The heating capacity when heating the heated object by performing the heat source water upper return operation is limited to be lower than the heating capacity when heating the heated object by performing the heat source water lower return operation. Control means for
Equipped with a,
A first upper port through which the heat source water that has passed through the use-side heat exchanger in the heat source water upper return operation flows into an upper region of the hot water storage tank, and an upper region of the hot water storage tank from the upper region of the hot water storage tank in the heat source water upper return operation. A second upper port for taking out the heat source water, and a lower port through which the heat source water that has passed through the use-side heat exchanger in the heat source water lower return operation flows into a lower region of the hot water storage tank,
The recovery ports for recovering the heat source water that has passed through the use side heat exchanger into the hot water storage tank are only two of the first upper port and the lower port,
Whether the first upper port and said second upper port is provided at a position of the same height, or hot-water storage type water heater the first upper port that provided at a position higher than the second upper opening.

The control means circulates the circulation flow rate of the heat source water that circulates to the use side heat exchanger when the heat source water upper return operation is executed to circulate to the use side heat exchanger when the heat source water lower return operation is executed. The hot water storage type hot water supply device according to claim 1, wherein the hot water storage type water heater is limited to be lower than a circulation flow rate of the heat source water.

The hot water storage type hot water heater according to claim 1 or 2, wherein the control means limits an operation continuation time of the heat source water upper return operation to be shorter than an operation continuation time of the heat source water lower return operation.

With an object to be heated circulating means for circulating the heated object to the use side heat exchanger,
The control unit circulates the circulation flow rate of the heated object that circulates to the use side heat exchanger when the heat source water upper return operation is executed to the use side heat exchanger when the heat source water lower return operation is executed. The hot water storage type hot water supply device according to any one of claims 1 to 3, wherein the hot water supply device is limited to be lower than a circulating flow rate of the object to be heated.

With an object to be heated circulating means for circulating the heated object to the use side heat exchanger,
The control means is configured such that the circulation duration time of the heated object circulated to the use side heat exchanger during the heat source water upper return operation is circulated to the use side heat exchanger during the heat source water lower return operation. The hot water storage type hot water heater according to any one of claims 1 to 4, wherein the hot water storage type water heater is limited so as to be shorter than a circulation time of the object.

The hot water storage type water heater according to any one of claims 1 to 5, wherein the use side heat exchanger heats bathtub water sent from a bathtub as the object to be heated.