JP5556738B2 - Hot water storage water heater - Google Patents

Description

  The present invention relates to a hot water storage type water heater.

  Conventionally, this type of hot water storage type hot water heater starts a heating operation when the amount of remaining hot water in the hot water storage tank falls below a predetermined amount, and the amount of remaining hot water at the start of the heating operation when the amount of hot water used on the previous day is less than a predetermined amount compared to the normal time. There are some which change many (for example, patent document 1).

JP 2003-279151 A

  For example, in the past few days, hot water heated by a heat pump unit was directly supplied to the use-side heat exchanger to heat the water to be heated, but one day suddenly hot water from a hot water storage tank was supplied to the use-side heat exchanger to be heated. When water is heated, the amount of hot water used in the hot water storage tank suddenly increases.

  However, in the conventional hot water storage type hot water heater, when the amount of hot water used on the previous day is less than a predetermined amount than usual, the remaining hot water amount at the start of the heating operation is changed to a large amount. When the hot water in the tank is supplied to the heat exchanger on the use side and the water to be heated is heated, the amount of hot water used in the hot water storage tank suddenly decreases, even though the amount of hot water used on the previous day is not less than the specified amount. There was a problem that the hot water runs out due to the increase.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a hot water storage type hot water heater that does not run out of hot water regardless of past hot water use conditions.

  A hot water storage type hot water supply apparatus according to the present invention has a hot water storage tank for storing hot water heated using a heating means, and a water circulation circuit connected to a tank in which water to be heated is stored, and the water circulation circuit The water circulation means for circulating the water to be heated using the water and the reheating means for heating the water to be heated flowing in the water circulation circuit, the reheating means is disposed in the water circulation circuit and the hot water stored in the hot water storage tank. One of the first reheating operation for exchanging heat with the flowing water to be heated and the second reheating operation for exchanging heat between the hot water heated using the heating means and the water to be heated flowing in the water circulation circuit. The hot water calorie history calculating means for selectively executing one of them and calculating the history of the calorie discharged from the hot water storage tank, and the remaining hot water amount to be stored in the hot water storage tank based on the history of a predetermined judgment period Set remaining hot water Setting means, additional boiling means for additionally boiling hot water in the hot water storage tank using heating means when the amount of heat in the hot water storage tank falls below the amount of remaining hot water, and the first reheating operation during the determination period Determining means for determining whether or not the second pursuit operation is prohibited, prohibiting means for prohibiting the execution of the second pursuit operation, and execution of the second pursuit operation is prohibited during the determination period when the first pursuit operation is not performed. And a raising means for raising the amount of heat of the remaining hot water.

  According to the present invention, it is possible to provide a hot water storage type hot water heater that does not cause hot water shortage regardless of past use conditions of hot water.

It is a block diagram of the hot water storage type water heater in Embodiment 1 of this invention. It is a circuit block diagram at the time of the boiling independent operation | movement of the hot water storage type water heater in Embodiment 1 of this invention. It is a circuit block diagram at the time of the heat pump direct reheating operation of the hot water storage type water heater in Embodiment 1 of the present invention. It is a circuit block diagram at the time of the hot water storage reheating operation of the hot water storage type hot water heater in Embodiment 1 of the present invention. It is a flowchart of control operation of the hot water storage type hot water heater showing Embodiment 1 of the present invention.

  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.

Embodiment 1 FIG.
FIG. 1 is a configuration diagram of a hot water storage type water heater 100 according to Embodiment 1 of the present invention. A hot water storage type water heater 100 shown in FIG. 1 includes a hot water storage tank unit 1 and a heat pump unit 60 configured to use a heat pump cycle. The two units 1 and 60 are connected by a heat pump inlet pipe 41 and a heat pump outlet pipe 42. The hot water storage tank unit 1 has a control unit 70 built therein. Operations of various valves, pumps and the like provided in the hot water storage tank unit 1 and the heat pump unit 60 are controlled by a control unit 70 electrically connected thereto. Hereinafter, each component of the hot water storage type water heater 100 will be described.

  The heat pump unit 60 functions as a heating means for heating (boiling) the low temperature water led from the hot water storage tank unit 1. The heat pump unit 60 includes a compressor 61, a heating heat exchanger 62, an expansion valve 63, and an air heat exchanger 64 connected in a ring shape with a refrigerant circulation pipe 65 to constitute a refrigeration cycle (heat pump cycle). The boiling heat exchanger 62 is for exchanging heat between the refrigerant flowing through the refrigerant circulation pipe 65 constituting the heat pump cycle and the low-temperature water led from the hot water storage tank unit 1. The HP outlet side thermistor 66 is a temperature sensor for detecting the temperature of the high-temperature water heated by the boiling heat exchanger 62, and is provided in the heat pump outlet pipe 42. In order to obtain high-temperature water by the heat pump unit 60, it is preferable that the heat pump cycle is operated at a pressure exceeding the critical pressure using carbon dioxide as a refrigerant.

  On the other hand, the hot water storage tank unit 1 incorporates the following various parts and piping. The hot water storage tank 10 is for storing hot water. A water supply pipe 2 for supplying city water is connected to the lower part of the hot water storage tank 10, and a hot water supply pipe 3 for supplying the stored hot water to the outside of the water heater is connected to the upper part of the hot water storage tank 10. The pipe 43 is branched and connected. In addition, the hot water heated by the heat pump unit 60 is introduced into the hot water storage tank 10 from the upper part of the tank, and the low temperature water is introduced from the lower part of the tank through the water supply pipe 2, thereby Hot water is stored so that a temperature difference occurs in the lower part. Moreover, the remaining hot water thermistors 11 and 12 for detecting the temperature distribution of the hot water in the hot water storage tank 10 are attached to the surface of the hot water storage tank 10 at different mounting heights. Based on the temperature distribution acquired by the remaining hot water thermistors 11 and 12, the amount of hot water in the hot water storage tank 10 is grasped, and the start and stop of the hot water boiling operation in the hot water storage tank 10 by the heat pump unit 60 is controlled. Is done.

  The hot water storage tank unit 1 includes a circulation pump 21 and a use side heat exchanger 22. The circulation pump 21 is a pump for circulating hot water through various pipes to be described later in the hot water storage tank unit 1. The use-side heat exchanger 22 uses the high-temperature water supplied from the hot water storage tank 10 and the heat pump unit 60 to heat the secondary-side heating target water (tub circulation water, heating circulation water, etc.). It is an exchanger. In the present embodiment, as a secondary side configuration of the use side heat exchanger 22, a bathtub water circulation circuit 51 that circulates hot water in the bathtub 50 will be described as an example. The use side heat exchanger 22 is installed in the middle of the bathtub water circulation circuit 51. Further, a secondary circulation pump 52 for circulating the bathtub water and a bathtub outlet side thermistor 53 for detecting the temperature of the bathtub water discharged from the bathtub 50 are installed in the middle of the bathtub water circulation circuit 51. Yes. Further, a hot water temperature sensor 54 and a hot water flow sensor 55 for detecting the temperature and flow rate of hot water discharged from the hot water storage tank 10 to the hot water supply pipe 3 are respectively installed in the hot water supply pipe 3.

  Next, valves and piping provided in the hot water storage tank unit 1 will be described. The hot water tank unit 1 has a three-way valve 31 and a four-way valve 32. The three-way valve 31 is a flow path switching means having two inlets (a port and b port) through which hot water flows and one outlet (c port) through which hot water flows out. Either the a port or the b port The hot water path can be switched so that hot water flows in from the water. The four-way valve 32 is a flow path switching means having two inlets (b port and c port) through which hot water flows and two outlets (a port and d port) through which hot water flows out. , A-b route and cd route are configured to be able to switch the flow path form.

  The hot water storage tank unit 1 includes a tank lower pipe 40, the heat pump inlet pipe 41, the heat pump outlet pipe 42, a tank upper pipe 43, a tank return pipe 44, and a use side heat exchanger primary side (heat source side) inlet pipe 45. The use side heat exchanger has a primary side outlet pipe 46 and a bypass pipe 47. Further, the circulation pump 21 is installed between the connection portion with the bypass pipe 47 on the first heat pump inlet pipe 41 and the three-way valve 31.

  The tank lower pipe 40 is a flow path that connects the first lower part of the hot water storage tank 10 and the a port of the three-way valve 31. The heat pump inlet pipe 41 is a flow path that connects the c port of the three-way valve 31 and the inlet side of the heat pump unit 60, and the heat pump outlet pipe 42 connects the outlet side of the heat pump unit 60 and the c port of the four-way valve 32. The tank upper pipe 43 is a flow path that connects the d port of the four-way valve 32 and the upper part of the hot water storage tank 10, and the tank return pipe 44 is the a port of the four-way valve 32 and the center of the hot water storage tank 10. It is the flow path which connects the return port provided between the part and the lower part. The use side heat exchanger primary side inlet pipe 45 branches from between the hot water storage tank upper part of the tank upper pipe 43 and the four-way valve 32 and is connected to the primary side inlet of the use side heat exchanger 22. The use side heat exchanger primary side outlet pipe 46 is a flow path that connects the primary side outlet of the use side heat exchanger 22 and the b port of the three-way valve 31. Further, the bypass pipe 47 is a flow path that branches from between the outlet side of the circulation pump 21 and the inlet side of the heat pump unit 60 in the heat pump inlet pipe 41 and is connected to the b port of the four-way valve 32.

  In the hot water storage type water heater 100 according to the present embodiment, the three-way valve 31 is controlled according to the operation state shown in FIGS. Thus, the hot water passage in the hot water storage tank unit 1 is switched and used. More specifically, the “first flow path configuration” that can be selected by the three-way valve 31 means that the first lower part of the hot water storage tank 10 and the heating heat exchanger 62 connect the tank lower pipe 40 and the heat pump inlet pipe 41. The “second flow path configuration” means that the use side heat exchanger primary side outlet pipe 46 and the heating heat exchanger 62 are connected via the heat pump inlet pipe 41. It is a flow path form that communicates.

  Furthermore, in the hot water storage type hot water heater 100 of the present embodiment, the following two first and second flow path configurations are controlled by controlling the four-way valve 32 in accordance with the operation states shown in FIGS. Switch between and use. More specifically, the “first flow path configuration” that can be selected by the four-way valve 32 is a flow path configuration in which the heating heat exchanger 62 and the tank upper pipe 43 communicate with each other via the heat pump outlet pipe 42. That is, the “second flow path configuration” is a flow channel configuration in which the bypass pipe 47 and the tank return pipe 44 communicate with each other.

  FIG. 2 is a circuit configuration diagram of the hot water storage type water heater 100 according to Embodiment 1 of the present invention at the time of a single heating operation. In addition, the boiling-up single operation here is a thing in which the boiling-up operation which uses the heat pump unit 60 to boil the water in the hot water storage tank 10 is performed independently. During this boiling-only operation, the three-way valve 31 communicates with the a-port and the c-port, and the b-port is closed (that is, the first flow path configuration of the three-way valve 31 is selected. Controlled). Accordingly, the tank lower pipe 40 and the heat pump inlet pipe 41 communicate with each other, and the flow path from the usage side heat exchanger 22 is blocked by closing the usage side heat exchanger primary side outlet pipe 46 side. Further, during the boiling-only operation, the four-way valve 32 is configured such that the c port and the d port communicate with each other and the a port and the b port are closed (that is, the first flow path configuration of the four-way valve 32 is To be controlled). Thereby, the heat pump outlet pipe 42 and the tank upper pipe 43 communicate with each other, and the flow paths on the tank return pipe 44 side and the bypass pipe 47 side are closed.

  The boiling-up single operation is executed by starting the operation of the circulation pump 21 and the heat pump unit 60 in a state where the three-way valve 31 and the four-way valve 32 are controlled as described above. As a result, the low-temperature water flowing out from the first lower part of the hot water storage tank 10 is guided to the heat pump unit 60 via the tank lower pipe 40, the three-way valve 31, the circulation pump 21 and the heat pump inlet pipe 41, and heat exchange for boiling is performed. After being heated in the vessel 62 to become hot water, it flows into the hot water storage tank 10 from the upper part of the hot water storage tank 10 through the heat pump outlet pipe 42, the four-way valve 32 and the tank upper pipe 43 and is stored. By performing such boiling-up independent operation, high-temperature water is stored in the hot water storage tank 10 from the upper layer portion, and the high-temperature water layer gradually becomes thicker. Thereafter, when the amount of remaining hot water in the hot water storage tank 10 ascertained by the remaining hot water thermistors 11 and 12 exceeds a predetermined amount, the boiling single operation is stopped.

  FIG. 3 is a circuit configuration diagram of the hot water storage hot water supply apparatus 100 according to Embodiment 1 of the present invention during a direct heat pump operation. Here, the heat pump direct reheating operation (second reheating operation) here refers to heat exchange between the hot water boiled using the heat pump unit 60 and the bath water in the use-side heat exchanger 22, and the bathtub This is an operation for heating water. During this direct heat pump operation, the three-way valve 31 communicates with the b-port and the c-port, and the a-port is closed (that is, the second flow path configuration of the three-way valve 31 is selected. To be controlled). As a result, the use side heat exchanger primary side outlet pipe 46 and the heat pump inlet pipe 41 communicate with each other, and the flow path on the tank lower pipe 40 side is closed. Further, during direct heat pump operation, the four-way valve 32 is configured such that the c port and the d port communicate with each other and the a port and the b port are closed (that is, the first flow path configuration of the four-way valve 32 is To be controlled). Thereby, the heat pump outlet pipe 42 and the tank upper pipe 43 communicate with each other, and the flow paths on the tank return pipe 44 side and the bypass pipe 47 side are closed.

  The heat pump direct recharging operation is executed by starting the operation of the circulation pump 21 and the heat pump unit 60 in a state where the three-way valve 31 and the four-way valve 32 are controlled as described above. As a result, medium-temperature water flowing out from the use-side heat exchanger primary-side outlet pipe 46 (water whose temperature has decreased due to heat exchange with the water in the bathtub 50) passes through the three-way valve 31, the circulation pump 21, and the heat pump inlet pipe 41. Then, it is led to the heat pump unit 60 and heated in the boiling heat exchanger 62. The high-temperature water that has become hot due to heat exchange is led to the use-side heat exchanger 22 via the heat pump outlet pipe 42, the four-way valve 32, and the tank upper pipe 43, and is heat-exchanged with the bath water to become medium-temperature water. On the other hand, in the path on the bathtub 50 side, the hot water stretched on the bathtub 50 circulates in the bathtub water circulation circuit 51 by operating the secondary circulation pump 52. As a result, the heat of the high-temperature water flowing through the primary side of the use side heat exchanger 22 is transmitted to the hot water flowing through the secondary side of the use side heat exchanger 22, and the hot water stretched in the bathtub 50 is warmed. As described above, in the direct heat pump operation, since the high-temperature water stored in the hot water storage tank 10 is not used, intermediate hot water is not generated in the hot water storage tank.

  Next, FIG. 4 is a circuit configuration diagram at the time of hot water reheating operation of hot water storage type water heater 100 in the first embodiment of the present invention. The hot water storage reheating operation (first reheating operation) here refers to heat exchange between the hot water stored in the hot water storage tank 10 and the bathtub water in the use side heat exchanger 22 to heat the bathtub water. This is the operation to be performed. During this hot water reheating operation, the three-way valve 31 communicates with the b-port and the c-port, and the a-port is closed (that is, the second flow path configuration of the three-way valve 31 is selected. Controlled). As a result, the use side heat exchanger primary side outlet pipe 46 and the heat pump inlet pipe 41 communicate with each other, and the tank lower pipe 40 side is closed and the flow path from the first lower part of the hot water storage tank 10 is blocked. The four-way valve 32 is controlled so that the a-port and the b-port communicate with each other and the c-port and the d-port are closed (that is, the second flow path configuration of the four-way valve 32 is selected). Is done. Thereby, the circulation pump 21 and the tank return pipe 44 communicate with each other through the bypass pipe 47, and the flow paths on the heat pump outlet pipe 42 side and the tank upper pipe 43 side are closed.

  The hot water reheating operation is executed by starting the operation of the circulation pump 21 and the secondary side circulation pump 52 in a state where the three-way valve 31 and the four-way valve 32 are controlled as described above. In addition, in this hot water storage reheating operation state, the operation of the heat pump unit 60 is stopped. As a result, the high temperature water flowing out from the upper part of the hot water storage tank 10 is guided to the use side heat exchanger 22 via the tank upper pipe 43 and the use side heat exchanger primary side inlet pipe 45, and between the hot water and the bath water. Heat exchange takes place at. Warm water (medium temperature water) that has become low temperature due to heat exchange is a heat exchanger primary side outlet pipe 46, a three-way valve 31, a heat pump inlet pipe 41, a circulation pump 21, a bypass pipe 47, a four-way valve 32, and a tank return pipe. The hot water storage tank 10 is returned to the hot water storage tank 10 through a return port provided in the lower part of the hot water storage tank 10. According to such a circulation path, since hot water stored in the hot water storage tank 10 is used, intermediate hot water is generated in the hot water storage tank 10. On the other hand, in the path on the bathtub 50 side, the hot water stretched on the bathtub 50 circulates in the bathtub water circulation circuit 51 by operating the secondary circulation pump 52. As a result, the heat of the high-temperature water flowing through the primary side of the use side heat exchanger 22 is transmitted to the hot water flowing through the secondary side of the use side heat exchanger 22, and the hot water stretched in the bathtub 50 is warmed.

  Next, the operation of the first embodiment will be described with reference to FIG. FIG. 5 is a flowchart of the control operation of the hot-water storage type water heater showing Embodiment 1 of the present invention. In the routine shown in FIG. 5, first, when the hot water stored in the hot water storage tank 10 is supplied to the outside of the water heater, the control unit 70 uses the flow rate and temperature detected by the hot water flow sensor 55 and the hot water temperature sensor 54. The amount of heat discharged from the hot water storage tank 10 used for hot water supply is calculated. Moreover, when the control part 70 heats bathtub water using the high temperature water supplied from the hot water storage tank 10, the hot water storage tank 10 used for reheating hot water storage from the amount of hot water of the bathtub water and the temperature rise value of the bathtub water. The amount of heat discharged from the water is calculated. Then, an integrated value per unit time (for example, 6 minutes) of the calculated heat quantity is calculated as Qj [m] for a predetermined period (for example, for the past two weeks) (step S201).

  Next, the amount of heat that can be boiled by the heat pump unit 60 per unit time (for example, 6 minutes) is subtracted from the calculated Qj [m] for a predetermined period, and the required amount of heat Qreq [m] per unit time. ] Is calculated. Next, among the required heat quantity Qreq [m], the largest value within a predetermined period (for example, the past two weeks) is calculated as the maximum required heat quantity Qreq_max to be stored in the hot water storage tank 10. Next, a value obtained by adding the margin dQon to Qreq_max is calculated as a startup remaining hot water heat amount Qon for starting the boiling water heating operation in the hot water storage tank 10 by the heat pump unit 60 (step S202).

  Next, during a predetermined period (for example, the past two weeks), the hot water stored in the hot water storage tank and the bathtub water are heat-exchanged by the use side heat exchanger 22 and the hot water storage reheating operation is performed to heat the bathtub water. Is determined (step S203). As a result, if the hot water reheating operation is not performed, it can be determined that the amount of heat for the hot water reheating operation is not taken into account in the startup remaining hot water heat amount Qon calculated in step S202. In this case, the process proceeds to the next step, and heat pump direct reheating operation in which the high-temperature water boiled using the heat pump unit 60 and the bath water are heat-exchanged in the use-side heat exchanger 22 and the bath water is heated. Is determined to be prohibited at the present time (step S204).

  Here, the state in which the direct heat pump operation is prohibited is, for example, either a hot water reheating operation or a heat pump direct reheating operation by an operation of an operation unit (not shown) that operates the hot water storage water heater. In an apparatus in which the user can arbitrarily select the hot water storage reheating operation (that is, the heat pump direct reheating operation is prohibited) or the like.

  In addition, as another example of the state in which the direct heat pump operation is prohibited, a bath water temperature maintaining operation is performed in which the bath temperature (for example, 42 ° C.) set by the user is maintained for a predetermined time (for example, 4 hours). There is a case. Specifically, in the bath water heat insulation operation, when the set bath temperature can be maintained within the heat retention upper limit time (for example, 15 minutes), the heat pump direct reheating operation is performed again in the next bath water heat insulation operation. When it is selected and cannot be kept within the heat retention upper limit time, the hot water reheating operation is selected in the next bath water heat retention operation. For this reason, for example, if the set bath temperature cannot be kept within the heat retention upper limit time and the hot water reheating operation is selected in the next bath water heat retention operation, the heat pump direct reheating operation is prohibited. It becomes a state.

  As another example, in order to reduce the number of heating operations in consideration of the life of the heat pump unit 60, the heat pump direct reheating operation is limited in the number of times within a predetermined period (for example, 7 days a day). In some cases, the direct pumping operation of the heat pump is prohibited by exceeding the limit.

  Next, if the hot water reheating operation is not performed during a predetermined period (for example, the past two weeks) and the direct heat pump reheating operation is prohibited at this time, the hot water reheating operation is performed. It is determined that the amount of heat generated in the hot water in the hot water storage tank 10 is started to be increased by adding the amount of heat dQjh for one hot water bath operation to the remaining amount of hot water Qon. Then, when the remaining hot water amount in the hot water storage tank 10 falls below Qon + dQjh, the operation of boiling hot water in the hot water storage tank 10 by the heat pump unit 60 is started (step S205).

  Here, dQjh is calculating | requiring and calculating | requiring the calorie | heat amount in the hot water storage tank 10 used for the bath water heat insulation driving | operation from the amount of hot water of a bath water, and the temperature rise value of a bath water (for example, the calorie | heat amount in the hot water storage tank 10 to be used = Bath water amount 180L × bath water temperature rise 2 ° C./conversion coefficient). In addition, in this Embodiment mentioned above, although one bath water heat insulation driving | operation is made into dQjh, it is good also as multiple times instead of one time. Alternatively, a fixed value stored in advance may be used.

  On the other hand, when it is determined in step S203 that the hot water reheating operation has been performed during a predetermined period (for example, the past two weeks), or in step S204, the heat pump direct reheating operation can be performed at the present time. If it is determined that it is, it can be determined that it is not necessary to increase the amount of heat of the remaining activated hot water for starting the boiling operation. In this case, when the remaining hot water amount in the hot water storage tank 10 falls below the startup remaining hot water amount Qon, the operation of boiling hot water in the hot water storage tank 10 by the heat pump unit 60 is started (step S206).

  As described above, according to the first embodiment of the present invention, the hot water reheating operation is not performed during a predetermined period (for example, the past two weeks), and the heat pump direct reheating operation is prohibited at the present time. If the hot water amount dQjh for one bath water heat insulation operation is added to the startup remaining hot water amount Qon and the remaining hot water amount in the hot water storage tank 10 falls below Qon + dQjh, Start boiling water. As a result, although the heat pump direct refueling operation has been carried out for the past several days, even if the hot water tank renewal operation is suddenly performed one day, the amount of hot water used in the hot water storage tank suddenly increases. Cutting can be prevented.

  By the way, in the above-described first embodiment of the present invention, when the hot water reheating operation is not performed for a predetermined period, and the heat pump direct reheating operation is currently prohibited. However, the amount of heat dQjh for one bath water heat insulation operation is added to the amount of remaining hot water Qon. It may be limited to a predetermined warming time that can be set. This makes it possible to minimize the boiling operation. Further, not only the amount of remaining hot water but also the target amount of hot water stored in the hot water storage tank 10 at night may be added with the amount of heat dQjh for one bath water heat insulation operation.

  Further, in the above-described first embodiment of the present invention, when the hot water reheating operation is not performed for a predetermined period and the direct reheating operation of the heat pump is prohibited at the present time, the activation is started. Although the heat quantity dQjh for one bath water heat insulation operation is added to the remaining hot water quantity Qon, the heating capacity of the heat pump unit 60 may be increased without adding dQjh.

  Moreover, in Embodiment 1 mentioned above, the bathtub water reheating operation which repels bathtub water was demonstrated as an example of the heating operation which heats heating object water. However, the heating operation of the present invention is not limited to this, and may be, for example, a heating operation using heating circulation water as heating target water.

  In Embodiment 1 described above, the heat pump cycle is a supercritical heat pump cycle in which the pressure of the refrigerant is equal to or higher than the critical pressure, but may be a heat pump cycle that is equal to or lower than a general critical pressure. In this case, chlorofluorocarbon, ammonia, or the like may be used as the refrigerant.

10 Hot water storage tank 50 Bathtub
51 Bath Water Circulation Circuit (Water Circulation Circuit)
52 Secondary circulation pump (water circulation means)
53 Bathtub side thermistor (temperature detection means)
60 Heat pump unit (heating means)
70 Control unit (selection means)

Claims (6)

A hot water storage tank for storing hot water heated using a heating means;
A water circulation means having a water circulation circuit connected to a tank in which the water to be heated is stored, and circulating the water to be heated using the water circulation circuit;
Reheating means for heating the water to be heated flowing in the water circulation circuit,
The reheating means includes a first reheating operation for exchanging heat between the hot water stored in the hot water storage tank and the heating target water flowing in the water circulation circuit; and hot water heated using the heating means; Selectively performing either one of the second reheating operation for exchanging heat with the heating target water flowing in the water circulation circuit;
A tapping heat quantity history calculating means for calculating a history of the quantity of heat discharged from the hot water storage tank;
Based on the history of a predetermined determination period, a remaining hot water calorie setting means for setting a remaining hot water calorie to be left in the hot water storage tank,
When the amount of heat in the hot water storage tank is lower than the amount of residual hot water, additional boiling means for additionally boiling hot water in the hot water storage tank using the heating means;
Determination means for determining whether or not the first chasing operation is performed in the determination period;
Prohibiting means for prohibiting execution of the second chasing operation;
A raising means for raising the amount of heat of the remaining hot water when the first reheating operation is not performed during the determination period and the execution of the second reheating operation is prohibited;
A hot water storage type water heater characterized by comprising: The tapping heat quantity history calculating means integrates tapping heat quantity discharged from the hot water storage tank every predetermined unit period,
The remaining hot water heat amount setting means sets, as the remaining hot water heat amount, a heat amount in the hot water storage tank that does not cause a shortage of heat with respect to a heat load corresponding to a maximum heat amount in the discharged heat amount during the determination period. The hot water storage type water heater according to claim 1. When the temperature of the heating target water is lowered, further comprising a heat retaining means for increasing the temperature of the heating target water using the reheating means,
The raising means adds the amount of heat necessary to continue the heat retaining means using the first reheating means to the remaining hot water amount to increase the remaining hot water heat amount. The hot water storage type water heater according to claim 1 or 2. An operation unit that allows the user to select one of the first chasing operation and the second chasing operation;
The said prohibiting means prohibits the driving | operation of a said 2nd chasing means, when the said 1st chasing operation is selected by operation of the said operation part by a user. The hot water storage type water heater according to any one of the above.   The said prohibiting means prohibits the execution of the second chasing operation when the number of times the second chasing operation is performed in a predetermined period exceeds a predetermined number of times. The hot water storage type water heater according to item 1. When the temperature of the heating target water is lowered, further comprising a heat retaining means for increasing the temperature of the heating target water using the reheating means,
The prohibiting means is a case where the second reheating operation is executed in the heat retaining means, and the heating target water cannot be raised to a target temperature within a predetermined time by the second reheating operation. In this case, the hot water storage type hot water heater according to any one of claims 1 to 3, wherein execution of the second reheating operation in the heat retaining means next time is prohibited.

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