JP2006336937A - Storage type hot water supply device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a storage type hot water supply device suppressing deposition of calcium carbonate, and minimizing a running cost of boiling operation. <P>SOLUTION: In a hot water supply control part 41 and a heat source control part 42, when the boiling operation is in an energy saving mode, the boiling operation is carried out on the basis of a target boiling temperature determined by adding a heat loss portion α from a passage 21 for fluid heating and a heat exchanger 30 for hot water supply to a set temperature set by a user. By this, the running cost of the boiling operation can be minimized. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a hot water storage hot water supply device comprising a hot water storage tank for storing a heat storage fluid heated by a heating means, and a heat exchanger for exchanging heat between the heat storage fluid in the hot water storage tank and a heat medium, In particular, the present invention relates to control for performing a boiling operation of a heat storage fluid stored in a hot water storage tank.

  Conventionally, as this type of hot water storage type hot water supply device, for example, a hot water storage tank for storing heat storage fluid, a heating means for heating the heat storage fluid, and a heat storage fluid in the hot water storage tank are distributed to the primary side and distributed to the secondary side There is known a heat pump type hot water storage hot water supply device that includes a heating heat exchanger that heats a heat medium that heats the hot water as a heat medium with the stored heat storage fluid and supplies hot water to a hot water supply location. .

Furthermore, the heating means comprises a heat pump cycle circuit in which an air heat exchanger provided with a refrigerant compressor, a heat storage heat exchanger, an expansion valve, and an outdoor fan is connected in an annular shape, and carbon dioxide is used as the refrigerant. Thus, a supercritical heat pump cycle in which the pressure of the refrigerant is equal to or higher than the critical pressure. That is, the heat storage fluid that is a heat source for hot water supply water is heated to a high temperature state (for example, about 65 to 90 ° C.) by the refrigerant whose pressure is increased to a critical pressure or more (for example, Patent Documents). 1).
JP 2001-153458 A

  However, in the hot water storage type hot water supply apparatus of Patent Document 1, a high temperature heat storage fluid can be stored in the hot water storage tank, but the stored heat storage fluid is consumed in accordance with the hot water supply operation after being stored in a high temperature state. Therefore, there is a problem that there is a large amount of heat loss that leaks to the outside when stored in the hot water storage tank and when circulating in the heat exchanger for heating.

  In addition, the heat storage fluid that circulates on the secondary side of the heat storage heat exchanger is a fluid obtained by adding a preservative, an antifreezing agent, LLC, or the like to water. Calcium carbonate CaCO3 is precipitated when heated to a high temperature of more than 0C. That is, there is a problem that calcium carbonate is deposited in the secondary circuit by performing a high-temperature boiling operation, and the secondary passage is blocked over time.

  Therefore, an object of the present invention is to provide a hot water storage type hot water supply apparatus that suppresses the precipitation of calcium carbonate and minimizes the running cost of the boiling operation.

In order to achieve the above object, the technical means described in claims 1 to 7 are employed. That is, in the invention according to claim 1, the hot water storage tank (10) for storing the heat storage fluid therein, and the lowermost heat storage fluid in the hot water storage tank (10) are disposed at the uppermost portion in the hot water storage tank (10). A fluid heating channel (21) to be sent, a heating means (20) provided in the fluid heating channel (21) for heating the heat storage fluid flowing in the fluid heating channel (21), and a hot water storage tank (10) Based on the amount of hot water stored in the hot water storage tank (10) and the heat exchanger for heating (30, 60) for circulating the heat storage fluid in the primary side and heating the heat medium flowing in the secondary side In a hot water storage type hot water supply apparatus provided with control means (41, 42) for controlling the heating means (20) and performing a boiling operation,
The heat medium heated by the heat exchanger (30, 60) for heating is hot water for supplying hot water to a hot water supply location or bath water for chasing bath water in a bathtub, and is a control means (41, 42). The hot water storage tank (10), the fluid heating channel (21), and the heat exchange for heating are added to either the hot water supply set temperature or the reheating set temperature set by the user when the boiling operation is in the energy saving mode. The heating operation is performed based on the target boiling temperature obtained by adding the heat loss (α) from the heaters (30, 60).

  According to the present invention, by setting either the hot water supply set temperature + heat loss (α) or the reheating set temperature + heat loss (α) as the target boiling temperature, the heat storage fluid can be heated to a high temperature as in the prior art. (For example, about 65 to 90 ° C.), rather than about 50 ° C., when it is stored in the hot water storage tank (10), and the heat exchanger for heating (30, 60) The heat loss that leaks to the outside when being distributed to the outside can be reduced. As a result, the running cost of the boiling operation can be minimized, and there is no precipitation of calcium carbonate on the heat storage fluid passage side of the heat storage heat exchanger (26).

  In the second aspect of the invention, the control means (41, 42) performs the boiling operation separately in the midnight time zone where the fee setting is low and the midnight time zone where the fee setting is high, and the target boiling temperature is It is characterized by the difference between midnight and non-midnight hours.

  According to the present invention, since the temperature difference between the outside air temperature and the heat storage fluid generally increases in the midnight time zone, for example, the target boiling temperature in the midnight time zone is set to be higher than other than the midnight time zone. Thus, the boiling operation is performed when the charge setting is low, and the running cost of the boiling operation can be minimized without causing hot water to be cut outside the midnight hours.

  In addition to the midnight time zone, for example, by setting the target boiling temperature in the vicinity of the set temperature, the boiling operation can be performed in a short time and the running cost of the boiling operation can be minimized.

  In the invention according to claim 3, the heating means (20) is from a heat pump cycle circuit comprising a compressor (25), a heat storage heat exchanger (26), an expansion valve (27) and an air heat exchanger (28). The control means (41, 42) is configured to control the capacity of the compressor (25) which is different between the midnight time zone and a time other than the midnight time zone.

  According to the present invention, in the midnight time zone, for example, the running cost of the boiling operation can be minimized by operating the compressor (25) with a good rated capacity of the COP. In addition to the midnight time zone, for example, by increasing the rotation speed of the compressor (25), the boiling operation can be performed in a short time and the running cost of the boiling operation can be minimized.

  The invention according to claim 4 is characterized in that the target boiling temperature is about 65 ° C. or less. According to this invention, it is difficult to deposit calcium carbonate on the heat storage fluid flow path side of the heat storage heat exchanger (26).

In the fifth aspect of the present invention, the control means (41, 42) calculates the amount of heat used for hot water supply and replenishment from the hot water storage tank (10) within the unit period, and stores the amount of heat used as data. Used heat quantity calculation means (290) to be stored as:
An average usage heat amount calculating means (300) for calculating an average usage heat amount within a predetermined period from the accumulated usage heat amount data within the unit period;
A variation calorific value calculation means (310) for calculating a variation calorific value within a predetermined period from the accumulated data on the amount of heat used within the unit period;
Based on the heat of use accumulated by the heat of use calculation means (290), the heat of use calculated by the means of heat of average use (300) and the heat of variation calculated by the heat of variance calculation (310), Boiling heat quantity calculation means (330, 340) to calculate,
The second heating control means (350) for heating the heating means (20) based on the heating heat quantity calculated by the boiling heat quantity calculation means (330, 340) is provided.

  According to this invention, according to the pattern in which the user uses the heat storage fluid in the hot water storage tank (10), the heating operation can be performed as necessary, and the running cost can be minimized. .

  In the invention according to claim 6, the heat exchanger for heating (30, 60) includes the first circulation part (30a) through which the heat storage fluid in the hot water storage tank (10) circulates and the second circulation through which the hot water supply water circulates. A part (30b) is provided adjacently, and the heat storage fluid and the hot water supply water are configured to face each other.

  According to this invention, the temperature of the heat storage fluid after passing through the first circulation part (30a) can be reduced to near the temperature of the hot water supply water before heating. Thereby, the heat loss at the time of heat exchange with the heat storage fluid and the hot water supply water can be reduced. Therefore, an efficient hot water supply system can be realized.

  In the invention according to claim 7, in the heat exchanger for heating (30, 60), the third circulating portion (60a) through which the heat storage fluid in the hot water storage tank (10) flows and the bath water in the bathtub flow. The fourth circulation part (60b) is provided adjacently, and the heat storage fluid and the bath water are configured to face each other.

  According to this invention, the temperature of the heat storage fluid after passing through the third circulation part (60a) can be reduced to near the temperature of the hot water supply water before heating. Thereby, the heat loss at the time of heat exchange with the heat storage fluid and the hot water supply water can be reduced. Therefore, an efficient hot water supply system can be realized.

  In addition, the code | symbol in the bracket | parenthesis of each said means shows a corresponding relationship with the specific means of embodiment mentioned later.

(First embodiment)
Hereinafter, a hot water storage type hot water supply apparatus according to a first embodiment of the present invention will be described with reference to FIGS. 1 and 2. FIG. 1 is a schematic diagram showing an overall configuration of a hot water storage type hot water supply apparatus to which the present invention is applied, and FIG. 2 is a flowchart showing a control process of a boiling operation showing a main part of the present invention.

  As shown in FIG. 1, the hot water storage type hot water supply apparatus of the present embodiment includes a hot water storage tank 10 that stores heat storage fluid therein, and a fluid that sends the lowest heat storage fluid in the hot water storage tank 10 to the uppermost portion in the hot water storage tank 10. Heating channel 21, heat pump unit 20 that is a heating means that heats the heat storage fluid, and hot water supply that is a heat exchanger for heating that heats the heat medium that flows through the heat storage fluid to the secondary side. Heat exchanger 30, circulation circuit 11 for circulating a heat storage fluid to the primary side of hot water supply heat exchanger 30, water supply pipe 31 connected to the secondary side upstream side of hot water supply heat exchanger 30, heat exchange for hot water supply The hot water supply pipes 32 and 33 are connected to the downstream side of the secondary side of the water heater 30, and control means (hot water supply control unit 41, heat source control unit 42) for controlling the operation of the hot water supply system.

  The hot water storage tank 10 is opened to the atmosphere through the air hole 10a, and the interior of the hot water storage tank 10 is maintained at atmospheric pressure. The hot water storage tank 10 is formed of, for example, a resin material and has a rectangular parallelepiped shape. And in order to reduce that the heat of the heat storage fluid stored in the hot water storage tank 10 is released from the wall surface of the hot water storage tank 10 into the atmosphere, the entire outer periphery of the hot water storage tank 10 is made of a heat insulating material such as glass wool or urethane. Covering.

  Further, the heat storage fluid used is mainly composed of water, and preservatives, antifreeze agents, LLC, and the like are added as necessary. In addition to these, a heat storage material having a high specific heat may be encapsulated by a technique such as a microcapsule and dispersed in water, or may be made into a thriller and flowable.

  Further, on the outer wall surface of the hot water storage tank 10, a water temperature sensor for detecting the hot water temperature at 20 liters, 50 liters, 100 liters, 150 liters, 200 liters, and 300 liters as measured from above. A plurality of hot water storage thermistors 55 are provided.

  Incidentally, the plurality of hot water storage thermistors 55 function as a hot water storage amount sensor for the heat storage fluid, and the hot water storage thermistor 55 provided at the uppermost part has a function of detecting the temperature of the hot water for discharging the hot heat storage fluid. The hot water storage thermistor 55 provided in the lower part functions as a full tank sensor.

  And the temperature information in each water level of heat storage fluid is output to the hot water supply control part 41 mentioned later. On the basis of temperature information from the plurality of hot water storage thermistors 55, the hot water supply control unit 41 is a boundary between the hot water heated above the hot water tank 10 and the low temperature heat storage fluid before being heated below the hot water tank 10. The position can be detected, and the hot water temperature of the heat storage fluid at each water level can be detected.

  Next, the heat pump unit 20 that heats the heat storage fluid uses a supercritical heat pump cycle in which, for example, carbon dioxide gas is used as a refrigerant, so that the refrigerant pressure on the high pressure side is equal to or higher than the critical pressure of the refrigerant. As is well known, this heat pump cycle includes refrigeration cycle functional parts such as a compressor 25, a heat storage heat exchanger 26, an expansion valve 27, an air heat exchanger 28, and an accumulator 29.

  Incidentally, the compressor 25 is driven by a built-in electric motor (not shown), and compresses and discharges the gas-phase refrigerant sucked from the accumulator 29 to a critical pressure or more. The heat storage heat exchanger 26 is a water-refrigerant heat exchanger that exchanges heat between the refrigerant and the heat storage fluid. For example, a refrigerant pipe 26a through which the refrigerant flows and a heat storage fluid path 26b through which the heat storage fluid flows are double tubes. The counter flow type water refrigerant heat exchanger is provided in the structure and is configured such that the flow direction of the refrigerant and the flow direction of the heat storage fluid are opposed to each other.

  The expansion valve 27 depressurizes the refrigerant flowing out of the heat storage heat exchanger 26 and supplies it to the air heat exchanger 28. The air heat exchanger 28 evaporates the refrigerant decompressed by the expansion valve 27 by heat exchange with the atmosphere. In the figure, reference numeral 28 a denotes a blower that blows air toward the air heat exchanger 28. The accumulator 29 gas-liquid separates the refrigerant flowing out from the air heat exchanger 28 and causes only the gas-phase refrigerant to be sucked into the compressor 25 and stores excess refrigerant in the cycle.

  Then, the heat storage fluid passage 26b side of the heat storage heat exchanger 26 is connected to the hot water storage tank 10 via the fluid heating flow path 21 described above, and the electric pump 24 is operated to store heat in the hot water storage tank 10. The working fluid circulates. The upstream end of the fluid heating channel 21 is connected to the bottom 10 b of the hot water storage tank 10, and the downstream end of the fluid heating channel 21 is connected to the upper part 10 c of the hot water storage tank 10.

  As a result, the heat storage fluid heated by heat exchange with the refrigerant in the heat storage heat exchanger 26 is sent to the upper portion 10c of the hot water storage tank 10, so that the heat storage fluid is sequentially stored from the upper side toward the lower side in the hot water storage tank 10. Heat is stored in the fluid. The heat pump unit 20 is operated by a control signal from a heat source control unit 42 described later, and outputs an operation state to the heat source control unit 42.

  In addition, the heat pump unit 20 performs a boiling operation for heating the heat storage fluid in the hot water storage tank 10 mainly using midnight power in the midnight time zone where the charge setting is the cheapest as a power source. In other words, the boiling operation is performed at midnight and a predetermined amount of heat storage fluid is stored in the hot water storage tank 10.

  In addition, if the amount of hot water stored in the heat storage fluid is reduced to a predetermined amount or less outside the midnight hours, a boiling operation is performed to store a predetermined amount of the heat storage fluid in the hot water storage tank 10. Incidentally, according to the supercritical heat pump cycle, a heat storage fluid having a higher temperature (for example, 85 to 90 ° C.) than a general heat pump cycle can be stored therein.

  Next, the circulation circuit 11 circulates the heat storage fluid in the hot water storage tank 10 to the first flow part 30a which is the primary side of the hot water supply heat exchanger 30 and heat exchange is performed in the hot water supply heat exchanger 30. A circulation circuit for returning the fluid to the lower part 10e in the hot water storage tank 10, a high temperature take-out pipe 12, an intermediate temperature take-out pipe 13, an outgoing pipe 14, a return pipe 15, a high / medium temperature mixing valve 16 as flow rate adjusting means, and The first circulation pump 17 is configured.

  The high-temperature take-out pipe 12 is a pipe for taking out a high-temperature heat storage fluid among the heat storage fluid stored in the hot water storage tank 10, and an upstream end is connected to an upper portion 10 d in the hot water storage tank 10. The medium temperature take-out pipe 13 is a pipe for taking out the medium temperature heat storage fluid having a lower temperature than the high temperature heat storage fluid among the heat storage fluid stored in the hot water storage tank 10. The upstream end is connected between 10d and the lower part 10e.

  The upstream pipe 14 has an upstream end connected to the outlet side of the high / medium temperature mixing valve 16, and a downstream end connected to the upstream end of the first flow part 30 a of the hot water heat exchanger 30. The return pipe 15 has an upstream end connected to the upstream end of the first circulation part 30 a and a downstream end connected to the lower part 10 e in the hot water storage tank 10. The forward pipe 14 is provided with a thermistor 54 before heat exchange, which is a pre-heat exchange water temperature sensor for detecting the hot water temperature of the heat storage fluid to be circulated through the first flow part 30a of the hot water supply heat exchanger 30. The temperature information in 14 is output to a hot water supply control unit 41 described later.

  Next, the high / medium temperature mixing valve 16 is provided at a downstream junction of the high temperature take-out pipe 12 and the intermediate temperature take-out pipe 13 and is a hot water temperature of a heat storage fluid that is circulated to the first flow part 30a of the hot water supply heat exchanger 30. The mixing ratio of the high-temperature heat storage fluid taken out from the high-temperature take-out pipe 12 and the medium-temperature heat storage fluid taken out from the medium-temperature take-out pipe 13 is adjusted by adjusting the ratio of the respective opening areas. I try to adjust it.

  The high / medium temperature mixing valve 16 is electrically connected to a hot water supply control unit 41 described later, and is controlled based on the temperature information of the heat storage fluid detected by the hot water storage thermistor 55 and the thermistor 54 before heat exchange. Is done. Incidentally, in this embodiment, when the hot water temperature of the heat storage fluid detected by the hot water storage thermistor 55 (in the vicinity of the intermediate temperature extraction pipe 13) is lower than a predetermined temperature (for example, 30 ° C.), the high temperature extracted from the high temperature extraction pipe 12 is high. The heat storage fluid is controlled to flow to the first flow part 30a.

  On the other hand, when the hot water temperature of the heat storage fluid detected by the hot water storage thermistor 55 (in the vicinity of the intermediate temperature extraction pipe 13) is equal to or higher than a predetermined temperature (for example, 30 ° C.), Control is performed so that both the medium-temperature heat storage fluid taken out from the medium-temperature take-out pipe 13 and the high-temperature heat storage fluid taken out from the high-temperature take-out pipe 12 are mixed and distributed to the first flow part 30a.

  Furthermore, the high / medium temperature mixing valve 16 is on the secondary side by adjusting the temperature of the hot water of the heat storage fluid flowing through the first flow section 30a detected by the thermistor 54 before heat exchange so as to be equal to or higher than a predetermined temperature. The hot-water supply water flowing through the second circulation part 30b is set so as not to be below a predetermined temperature (for example, about a set temperature + 2 ° C.).

  Thus, more medium temperature heat storage fluid in the vicinity of a predetermined temperature (for example, 30 ° C.) than the high temperature heat storage fluid is circulated to the first flow part 30a. Further, the high / medium temperature mixing valve 16 performs feedback control based on the hot water temperature of the heat storage fluid before heat exchange detected by the thermistor 54 before heat exchange.

  The 1st circulation pump 17 is arrange | positioned in the middle of the return pipe 15, and is a pump which distribute | circulates the thermal storage fluid in the hot water storage tank 10 to the 1st distribution part 30a. And hot water supply control mentioned later so that a rotation speed is controlled based on the hot water temperature of the hot water for hot water exchanged from the 2nd circulation part 30b of the heat exchanger 30 for hot water supply detected by the thermistor 52 after heat exchange mentioned later. The unit 41 is electrically connected.

  The circulation circuit 11 and the fluid heating passage 21 are provided with drain plugs 18 so that the heat storage fluid in the hot water storage tank 10 and the circulation circuit 11 can be drained manually if necessary. ing.

  Next, the hot water supply heat exchanger 30 is connected to the circulation circuit 11 so that the heat storage fluid in the hot water storage tank 10 flows, and the second water supply pipe 31 and the second hot water supply pipe 32 are connected to the hot water supply pipe 32. For example, it has a double pipe structure in which the second circulation part 30b is inserted into the first circulation part 30a. Here, it is desirable that the first flow part 30a uses a resin material in order to keep heat loss low, and the second flow part 30b uses a copper material having a high thermal conductivity.

  Further, the second flow part 30b may be a cylindrical tube as in the case of the first flow part 30a, but a radial uneven shape may be provided on the wall surface thereof. In this case, the heat transfer area between the first circulation part 30a and the second circulation part 30b increases, and the heat exchange efficiency between the heat storage fluid and the hot water supply water can be improved. In addition, it is good to cover the outer periphery of the 1st distribution | circulation part 30a with the heat insulating material (not shown) for preventing the thermal radiation of the heat storage fluid.

  As shown in FIG. 1, the hot water heat exchanger 30 is arranged vertically outside the hot water storage tank 10 so that the downstream end of the first circulation part 30 a communicates with the lower part 10 d of the hot water storage tank 10. Connected to the return pipe 15, the upstream end of the first flow part 30 a is connected to the forward pipe 14. Further, the second circulation part 30 b has an upstream end connected to the water supply pipe 31 and a downstream end connected to the hot water supply pipe 32.

  As a result, the hot water supply heat exchanger 30 has the flow direction of the heat storage fluid flowing from the top to the bottom and the second circulation portion 30b from the bottom to the top as shown by the arrows in FIG. It is a counterflow type heat exchanger with which the flow direction of the hot water for water which flows toward is opposed.

  The upstream of the water supply pipe 31 is connected to a water supply pipe so that the tap water is led to the hot water supply heat exchanger 30. Further, a water supply thermistor 51 is provided in the water supply pipe 31 so as to output temperature information of tap water to a hot water supply control unit 41 described later.

  Further, the hot water supply pipe 32 has a flow rate adjusting valve 34 for adjusting the flow rate of the hot water supplied by the second circulation part 30 b, and the hot water supply temperature at the junction of the downstream end of the hot water supply pipe 32 and the water supply pipe 31. A hot water supply mixing valve 35 as an adjusting means is provided. A hot water supply pipe 33 is connected to the outlet side of the hot water supply mixing valve 35.

  The hot water supply pipe 33 is a hot water supply pipe that leads to a hot water tap (not shown) such as a kitchen or bathroom. A hot water supply thermistor 53 and a flow rate counter 58 are provided in the middle thereof. The hot water supply thermistor 53 provides temperature information in the hot water supply pipe 33, and the flow rate counter 58 provides flow information in the hot water supply pipe 33 to the hot water supply control unit 41 described later. I am trying to output.

  The hot water supply pipe 32 is provided with a post-heat exchange thermistor 52 that detects the hot water temperature of the heat storage fluid heat-exchanged by the hot water supply heat exchanger 30, and temperature information in the hot water supply pipe 33 is described later. The data is output to the control unit 41.

  The flow rate adjustment valve 34 is a valve that adjusts the flow rate that flows through the second flow unit 30b, and is controlled by a hot water supply control unit 41, which will be described later, so that the flow rate that flows through the second flow unit 30b is less than or equal to a predetermined flow rate. That is, control is performed based on the hot water temperature of the hot water detected by the thermistor 52 after heat exchange so that the flow rate does not become excessive due to variations in the water pressure of the supplied water and the pressure loss in the hot water supply path.

  Next, the hot water supply mixing valve 35 is a temperature adjustment valve that adjusts the hot water temperature of the hot water to be discharged from the hot water supply pipe 33, and heat exchange is performed in the second circulation part 30b by adjusting the ratio of the respective opening areas. Control is performed to adjust the mixing ratio of the supplied hot water and tap water to the set temperature. The hot-water supply mixing valve 35 is electrically connected to a hot-water supply control unit 41, which will be described later. The hot-water supply water temperature information detected by the hot-water supply thermistor 51, the post-heat exchange thermistor 52, and the hot-water supply thermistor 53 is used. Controlled based on.

  Incidentally, the hot water temperature of the hot water supplied by the second circulation part 30b that is circulated to the hot water mixing valve 35 is set to, for example, a set temperature of about + 1 ° C. That is, the flow rate circulating in the circulation circuit 11 and the hot water temperature of the heat storage fluid detected by the thermistor 54 before heat exchange are controlled. The hot water supply mixing valve 35 performs feedback control based on the hot water temperature of hot water supply water detected by the hot water supply thermistor 53.

  Next, the hot water supply control unit 41 is mainly composed of a microcomputer, and a built-in ROM (not shown) is provided with a preset control program, and temperature information from the thermistors 51 to 55, Based on the flow rate information from the flow rate counter 58 and an operation signal from an operation switch provided on an operation panel (not shown), the first circulation pump 17, the high / medium temperature mixing valve 16, the flow rate adjusting valve 34, the hot water supply mixing valve 35, etc. The circulation circuit 11 and the hot water supply pipes 32 and 33 are configured to control the actuators.

  Like the hot water supply control unit 41, the heat source control unit 42 is mainly composed of a microcomputer, and a built-in ROM (not shown) is provided with a preset control program, and various thermistors (not shown) are provided. The actuators in the heat pump unit 20 are controlled on the basis of temperature information and the like.

  When the heating operation for heating the heat storage fluid in the hot water storage tank 10 is performed, the heat source control unit 42 controls the rotation speed of the electric pump 24 based on the temperature detected by the hot water storage thermistor 55 provided at the top. ing. That is, the flow rate of the heat storage fluid flowing through the heat storage fluid passage 26b of the heat storage heat exchanger 26 is controlled to be the target boiling temperature by controlling the rotation speed of the electric pump 24.

  By the way, the boiling operation of the present embodiment has a normal operation mode and an energy saving mode. In the normal operation mode, the target boiling temperature is set to an upper limit value (for example, 65 to 90 ° C. or less) to save energy. In the mode, the target boiling temperature is set to a lower limit value (for example, near the set temperature to 65 ° C. or less).

  In other words, the energy saving mode is intended to reduce the heat loss leaked to the outside by lowering the hot water temperature of the heat storage fluid stored in the hot water storage tank 10, and the running cost of the boiling operation can be reduced. This operation mode is selected by an operation switch (not shown) provided on the operation panel.

  Next, the operation of the boiling operation of the hot water storage type hot water supply apparatus having the above configuration will be described with reference to FIG. FIG. 2 is a flowchart showing the control process of the boiling operation when the energy saving mode is selected. First, when a heating operation switch (not shown) is turned on, the boiling operation starts. In step 410, it is determined whether or not the energy saving mode is selected.

  Here, if the operation mode selection switch is in the energy saving mode, the control process of the heating operation in the energy saving mode starts. Here, in the normal operation mode, the boiling operation in the normal operation mode (detailed explanation is omitted) is performed. In step 420, the current time zone is determined. Here, if it is a midnight time zone (for example, from 23:00 to 7:00 in the next morning), in step 430, is the current amount of stored hot water equal to or greater than a predetermined amount L1 (for example, 100 liters of heat storage fluid at 50 ° C. or higher) Determine whether or not.

  Here, if it is equal to or greater than the predetermined amount L1, the process returns to step 420 and waits. If it is less than the predetermined amount L1, the process proceeds to step 440. The current hot water storage amount is a hot water storage thermistor 55 provided at a water level level corresponding to 100 liters of hot water storage amount measured from above the hot water storage tank 10 among the plurality of hot water storage thermistors 55 provided in the hot water storage tank 10. Calculated based on the hot water temperature detected in.

  If the amount of stored hot water is less than the predetermined amount L1, in step 440, the boiling operation is performed. In the boiling operation, the heat source control unit 42 drives the heat pump cycle so that a high-pressure refrigerant equal to or higher than the critical pressure is circulated to the refrigerant passage 26 a side of the heat storage heat exchanger 26.

  This is an operation in which low-temperature hot water sucked into the high-pressure refrigerant from the lower part of the hot water storage tank 10 is circulated to the heat storage fluid passage 26 b side and heated, and the heated heat storage fluid stores hot water from the upper part of the hot water storage tank 10. At this time, in the fluid heating channel 21, the rotation speed of the electric pump 24 is controlled to a flow rate at which the hot water temperature heated by the heat storage heat exchanger 26 becomes the target boiling temperature.

  Here, the target boiling temperature is set to a temperature about 5 ° C. higher than the set temperature at the time of hot water supply from a hot water tap (not shown). In step 450, it is determined whether or not the boiling temperature detected by the hot water storage thermistor 55 provided in the lowermost part has reached or exceeded a predetermined temperature K1 (target boiling temperature = set temperature + 5 ° C.). If the temperature is lower than K1, the process returns to Step 440 and the boiling operation is continued. When the temperature reaches a predetermined temperature K1 or more, the process proceeds to Step 460 and the boiling operation is stopped.

  On the other hand, if the current time zone is other than the midnight time zone in step 420, the current hot water storage amount is a predetermined amount L2 (for example, 200 liters of heat storage fluid at 50 ° C. or higher) in step 470. It is determined whether or not there is.

  Here, if it is equal to or greater than the predetermined amount L2, the process returns to step 420 and waits. If it is less than the predetermined amount L2, the process proceeds to step 480. In step 480, a boiling operation is performed. Note that the target boiling temperature at this time is set to a temperature lower than step 440, for example, a set temperature + 3 ° C.

  Accordingly, in step 490, it is determined whether or not the boiling temperature detected by the hot water storage thermistor 55 provided at the bottom has reached a predetermined temperature K2 (target boiling temperature = set temperature + 3 ° C.) or higher. If it is less than K2, the process returns to step 480 and the boiling operation is continued. When the temperature reaches a predetermined temperature K2 or higher, the process proceeds to step 460 and the boiling operation is stopped.

  Thereby, in the midnight time zone, the heat storage fluid having the target boiling temperature (set temperature + 5 ° C.) is stored in the approximately 300 liter hot water storage tank 10, and the target boiling temperature (set temperature +3) is set outside the midnight time zone. Is stored in the hot water storage tank 10 of about 300 liters.

  In steps 430 and 470, 50 ° C. is used to determine the predetermined amounts L1 and L2. However, the present invention is not limited to this value, and it may be equal to or higher than the target boiling temperature (set temperature + 5 ° C. or set temperature + 3 ° C.). good.

  When the user opens a hot water tap (not shown) at the end of the hot water supply pipe 33 as required, flow rate information is output to the hot water supply control unit 41 by the flow rate counter 58, and first, the first circulation pump 17 is activated. Thereby, the heat storage fluid in the hot water storage tank 10 is circulated through the first circulation part 30a of the hot water supply heat exchanger 30. That is, the hot water supply water flowing through the second circulation part 30b of the hot water supply heat exchanger 30 receives the heat energy of the heat storage fluid and is heated.

  At this time, the heat storage fluid circulated through the first circulation portion 30a is a high-temperature heat storage fluid taken out from the high-temperature take-out pipe 12 by the high / medium-temperature mixing valve 16, or a medium-temperature heat storage take-out from the medium-temperature take-out pipe 13. The heat storage fluid having a hot water temperature of a predetermined temperature or more by mixing from both the medium fluid or the medium temperature heat storage fluid extracted from the medium temperature extraction pipe 13 and the high temperature heat storage fluid extracted from the high temperature extraction pipe 12 is the first circulation. It is controlled to be supplied to the unit 30a.

  At this time, the first circulation pump 17 controls the rotation speed based on the hot water temperature detected by the thermistor 52 after heat exchange. That is, when the detected hot water temperature after the heat exchange is lower than a predetermined temperature (for example, a set temperature + 1 ° C.), the rotational speed of the first circulation pump 17 is increased and the heat storage is distributed to the first circulation unit 30a. Increase fluid flow. Thereby, since the amount of heat exchange between the heat storage fluid and the hot water supply water increases, the hot water temperature of the hot water after the heat exchange rises.

  On the other hand, when the detected hot water temperature is higher than a predetermined temperature (for example, a set temperature + 1 ° C.), the flow rate of the heat storage fluid circulated to the first circulation part 30a by reducing the rotation speed of the first circulation pump 17. Decrease. Thereby, since the amount of heat exchange between the heat storage fluid and the hot water supply water decreases, the hot water temperature of the hot water after the heat exchange decreases.

  The hot-water supply water heat-exchanged to a predetermined temperature (for example, set temperature + 1 ° C.) by the hot-water supply heat exchanger 30 is set by mixing with the water supplied from the water supply pipe 31 in the hot-water supply mixing valve 35a. The hot water supply water adjusted to the temperature is discharged from the hot water supply pipe 33.

  In this embodiment, the target boiling temperature when performing the boiling operation is set as the set temperature + 5 ° C. during the midnight time zone and as the set temperature + 3 ° C. during the time other than the midnight time zone. + 5 ° C. and + 3 ° C. are heat loss α that leaks heat from the hot water storage tank 10, the circulation circuit 11, and the hot water supply heat exchanger 30 to the outside, and by adding this heat loss α to the set temperature, the hot water supply pipe 33 It is possible to adjust the hot water supply water to be set to a set temperature.

  In addition, the target boiling temperature is set as the lower limit value as described above, but the present invention is not limited to this, and the target boiling temperature may be set higher than this. However, the maximum is desirably 65 ° C. or less. In this case, when water of high hardness is used as the heat storage fluid, calcium carbonate CaCO 3 is precipitated when heated to about 65 ° C. or higher.

  That is, when the boiling operation is performed at a target boiling temperature of 65 ° C. or higher, calcium carbonate CaCO 3 is deposited in the heat storage flow path 26 b of the heat storage heat exchanger 26, and the heat storage flow path 26 b passes over time. There is a problem of blocking the inside with calcium carbonate CaCO3. Therefore, precipitation of calcium carbonate CaCO 3 can be prevented by performing a boiling operation at about 65 ° C. or less.

  According to the hot water storage type hot water supply apparatus of the first embodiment described above, when the boiling operation is in the energy saving mode, the set temperature set by the user is supplied from the hot water storage tank 10, the circulation circuit 11, and the heat exchanger 30 for heating. The boiling operation is performed based on the target boiling temperature obtained by adding the heat loss α.

  Thus, since the heat storage fluid is not heated to a high temperature state (for example, about 65 to 90 ° C.) as in the prior art, rather, the lower limit value may be about 50 ° C., and therefore stored in the hot water storage tank 10. The heat loss that leaks to the outside when flowing through the heating heat exchanger 30 can be reduced. Therefore, the running cost of the boiling operation can be minimized, and there is no precipitation of calcium carbonate CaCO3 on the heat storage fluid passage 26b side of the heat storage heat exchanger 26.

  The hot water supply control unit 41 and the heat source control unit 42 perform the boiling operation separately for a midnight time zone where the rate setting is low and a midnight time zone where the rate setting is high, and the target boiling temperature is a midnight time zone and a midnight time zone. Since the temperature difference between the outside air temperature and the heat storage fluid generally increases in the midnight time zone, for example, the target boiling temperature in the midnight time zone is set higher than in other than the midnight time zone. Thus, the boiling operation is performed when the charge setting is low, and the running cost of the boiling operation can be minimized without causing hot water to be cut outside the midnight hours.

  In addition to the midnight time zone, for example, by setting the target boiling temperature in the vicinity of the set temperature, the boiling operation can be performed in a short time and the running cost of the boiling operation can be minimized. Furthermore, when the target boiling temperature is about 65 ° C. or less, precipitation of calcium carbonate CaCO 3 can be prevented in the heat storage flow path 26 b of the heat storage heat exchanger 26.

  The hot water supply heat exchanger 30 is provided adjacent to the first flow part 30a through which the heat storage fluid in the hot water storage tank 10 flows and the second flow part 30b through which the hot water supply water flows, and the heat storage fluid and the hot water supply. By being configured so as to be opposed to the water, the temperature of the heat storage fluid after passing through the first circulation part 30a can be reduced to the vicinity of the temperature of the hot water supply water before heating. Thereby, the heat loss at the time of heat exchange with the heat storage fluid and the hot water supply water can be reduced. Therefore, an efficient hot water supply system can be realized.

(Second Embodiment)
In the first embodiment described above, when the boiling operation is performed, the entire amount of the heat storage fluid in the hot water storage tank 10 is heated. However, the present invention is not limited thereto. For example, the heat storage fluid is used for hot water supply in a unit period. Calculates the amount of heat used for hot water supply water, accumulates the amount of heat used as data, and based on the amount of heat used, the average amount of heat used and the amount of variation used within a predetermined period (for example, 7 days) from the accumulated amount of heat used You may comprise so that the amount of boiling heat of the day may be calculated and it may be boiled to the amount of stored hot water corresponding to the amount of boiling heat.

  Here, as a feature of the heating operation of the present embodiment, when a day break time (for example, 23:00, which is a midnight time zone) is mainly reached, a unit period from 23:00 on the previous day to 23:00 on the current day The amount of heat used is calculated from the amount of heat stored in the heat storage fluid consumed within (for example, one day).

  Then, the heating operation is performed in the midnight time zone (for example, between 23: 00 and 7:00) where the power rate setting after the above-described break time is the lowest. At other times, the current heat storage amount in the hot water storage tank 10 is calculated, and the boiling operation is performed when the heat storage amount falls below the minimum heat storage amount.

  Specifically, the boiling operation is performed based on the flowchart shown in FIG. First, a heating operation switch (not shown) is operated among various operation switches (not shown). Thereby, as shown in FIG. 3, the hot water supply control part 41 starts the control process of a boiling operation (step 210).

  And the boiling operation which is the 1st boiling means in step 220 is performed. This first boiling means monitors the current heat storage amount in the hot water storage tank 10 at a time other than the break time of step 280 described later, and performs a boiling operation when the heat storage amount falls below a predetermined amount. First, at step 230, based on the temperature information detected by the plurality of hot water storage thermistors 55, the amount of hot water stored above a predetermined temperature (for example, 50 ° C.) is detected.

  Then, the amount of stored heat is calculated based on the amount of stored hot water. Next, in step 240, the heat storage amount is compared with the variation heat amount, and it is determined whether or not the heat storage amount is less than the variation heat amount. Here, when the current heat storage amount is less than the variation heat amount, a boiling operation is performed in step 250. Then, in the next step 260, it is determined whether or not the current heat storage amount has reached the variation heat amount or more.

  Here, if the current heat storage amount is greater than or equal to the variation heat amount, the boiling operation is stopped in step 270. It should be noted that the amount of variation in the above-described Step 240 and Step 260 is the past predetermined period (for example, 7) obtained one day before reaching the day break time (for example, 23:00) of Step 280 described later. It is obtained by conversion from the variation heat quantity σ corresponding to the first and second boiling heat quantities obtained from the heat quantity used, the average heat quantity used, and the variation heat quantity for each unit period (for example, one day) within (days).

  In step 240, when the current heat storage amount exceeds the variation heat amount, the boiling operation is not performed. Next, when the delimiter time (for example, 23:00) has been reached, it is determined in step 280 whether or not the current time has reached 23:00. The accumulated heat amount consumed on that day (for example, from 23:00 to 23:00 on the previous day) is accumulated to calculate the amount of heat used, and the amount of heat used per day is stored in a ROM (not shown) of the hot water supply control unit 41. Remember.

  Note that the stored amount of heat used per day is stored so that it accumulates for a predetermined period in the past (for example, 7 days). The amount of heat used per day is calculated based on the amount of hot water stored at a predetermined temperature or higher (for example, 50 ° C.) detected after the boiling operation on the previous day and the amount of hot water stored at a predetermined temperature or higher (for example, 50 ° C.). You may obtain | require by the difference with the mutual heat storage amount based on.

  Here, assuming that the daily heat consumption is Qday, the daily heat consumption until one week before the past is Qdayn, Qdayn-1, Qdayn-2,..., Qdayn-5, Qdayn-6. Then, in step 300 which is the next average heat amount calculation means, the average use heat amount is calculated as the average use heat amount Qav = (Qdayn + Qdayn−1 + Qdayn−3 + Qdayn−4 + Qdayn−5 + Qdayn−6) / 7 is calculated.

  Here, the predetermined period of the accumulated data on the amount of heat used is the past seven days, but is not limited to this. For example, the accumulated data may be accumulated in the past month, a seasonal period, or the like. Next, in step 310 which is a variation heat amount calculation means, a variation heat amount σ is calculated. Here, the difference (deviation) between the average amount of heat used calculated in step 300 and the amount of heat used accumulated for the past seven days is squared, and is obtained from the square root of the value obtained by arithmetically averaging it. This is a standard deviation.

  Then, in step 320, which is a heating heat quantity determination means, the latest use heat quantity, that is, the use heat quantity on the previous day calculated in step 290 is larger than the average use heat quantity among the accumulated heat use for the past seven days. It is determined whether or not.

  Here, when the amount of heat used on the previous day is large, in step 330 which is a boiling heat amount calculation means, a first boiling heat amount which is an assumed amount of heat used on that day is obtained. At this time, it is determined that the amount of hot water used on the day assumed to be larger than the average heat of use is outside the use range, and the heat of use on the previous day is directly used as the first boiling heat.

  On the other hand, when the amount of heat used on the previous day is small, the second amount of heating heat that is the amount of heat used on the current day is obtained in step 340, which is a heating heat amount calculation means. At this time, it is determined that the amount of hot water used on the day assumed to be smaller than the average amount of heat used is within the use range, and the average amount of heat used is defined as the second boiling heat amount.

  Then, the amount of heat used on the previous day, which is the first boiling heat amount, and the average amount of heat used, which is the second boiling heat amount, are boiled based on the respective heat amounts and the boiling target temperature (for example, about the set temperature + 5 ° C.). Convert the amount. Then, in step 350, which is the second boiling means, the boiling operation, which is the starting condition determined in step 320, is heated up to the boiling target temperature K1.

  Specifically, in step 360, the second boiling means outputs to the heat pump unit 20 to operate the boiling operation, and in step 370, the hot water temperature detected by the hot water storage thermistor 53 is raised. The heat pump unit 20 is operated until the target temperature K1 is reached. When the hot water temperature rises above the target temperature K1 at step 370, the heating operation of the heat pump unit 20 is stopped at step 380. Be controlled.

  Thereby, in the midnight time zone (for example, from 23:00 to 7:00), the boiling amount corresponding to the use heat amount of hot water for hot water used on the next day (from 23:00 on the next day to 23:00 on the next day) is heated. be able to.

  According to the above embodiment, the usage heat amount calculating means for calculating the usage heat amount, the average usage heat amount calculation means for calculating the average usage heat amount, the variation heat amount calculation means for calculating the variation heat amount, the usage heat amount, the average usage heat amount and It has boiling heat amount calculation means for calculating the amount of boiling heat based on the variation amount of heat, and second boiling control means for boiling the heat pump unit 20 based on the amount of heating heat.

  Thereby, when performing the boiling operation, the boiling target temperature is set to, for example, about the set temperature + 5 ° C., so that the heat storage fluid is in a high-temperature state as in the past (for example, about 65 to 90 ° C.). Since the lower limit may be about 50 ° C. without heating, it is possible to reduce the heat loss that leaks to the outside when stored in the hot water storage tank 10 and when circulating in the heat exchanger 30 for heating. . Therefore, the running cost of the boiling operation can be further minimized as compared with the first embodiment.

(Third embodiment)
In the above embodiment, when the boiling operation is performed, the capacity control on the compressor 25 side has not been described, but the present invention is not limited to this, and the capacity of the compressor 25 is different between the midnight time zone and other than the midnight time zone. As described above, the boiling operation may be performed by controlling the capacity.

  Specifically, the compressor 25 is formed by an electric compressor incorporated in an electric motor, and the electric motor is controlled by an inverter control mechanism (not shown) so as to continuously change the rotation speed. The inverter control mechanism is controlled by the heat source control unit 42.

  And a boiling operation is performed based on the flowchart shown in FIG. Specifically, in step 510, the current time zone is determined. Here, if it is a midnight time zone (for example, from 23:00 to 7:00 in the next morning), it is determined in step 520 whether or not there is a request to perform a boiling operation. If there is a request, the process proceeds to step 530. If there is no request, the process returns to step 530 and waits.

  In step 530, the rotational speed of the rated capacity is output to an inverter control mechanism (not shown). As a result, the compressor 25 is operated at the rated capacity. On the other hand, in step 510, if it is outside the midnight time zone (for example, 7:00 to 23:00), it is determined in step 540 whether or not there has been a request to perform a boiling operation. If there is a request, the process proceeds to step 550. If there is no request, the process returns to step 530 and waits. In step 550, the rotational speed exceeding the rated capacity is output to an inverter control mechanism (not shown). Thereby, the compressor 25 is operated with a capacity equal to or higher than the rated capacity.

  According to the above configuration, by performing a heating operation in which the rotation speed of the compressor 25 is different in a midnight time zone where the charge setting is low and a midnight time zone where the charge setting is high, a short period is obtained outside the midnight time period. In addition, it is possible to save energy in running costs by performing predetermined boiling.

(Other embodiments)
In the above embodiment, the present invention is applied to the hot water storage type hot water supply apparatus having the hot water supply heat exchanger 30 for exchanging heat between the heat storage fluid in the hot water storage tank 10 and the hot water supply water. In addition to the heat exchanger 30, the present invention may be applied to a hot water storage type hot water supply apparatus having a reheating heat exchanger 60 which is a heat exchanger for reheating the bath water in the bathtub.

  Specifically, as shown in FIG. 5, the circulation circuit 11 is provided with a reheating heat exchanger 60 and a circulation circuit 11 a in parallel with the hot water supply heat exchanger 30. And it is comprised so that the heat storage fluid in the hot water storage tank 10 may be distribute | circulated to the 3rd distribution | circulation part 60a of the reheating heat exchanger 60, and the bath water in a bathtub may be circulated to the 4th distribution | circulation part 60b.

  Thereby, the bath water in the bathtub can be heated by the reheating heat exchanger 60 using the heat storage amount of the heat storage fluid in the hot water storage tank 10 as a heat source. In addition, a hot water supply pipe 32 for guiding hot water supplied by the hot water supply heat exchanger 30 is provided with branched hot water supply pipes 32a and 33a for filling hot water in the bathtub.

  Of the reference numerals shown in the figure, those having the same configuration as the first embodiment are indicated by the same reference numerals and description thereof is omitted. Since the codes other than the codes 11a, 60, 60a, 60b, 32a, and 33a described above are based on the specification of Japanese Patent Application Laid-Open No. 2004-14827 filed by the applicant, the description thereof is omitted here.

  In the above embodiment, the heat pump unit 20 using carbon dioxide as a refrigerant has been described as a heat source device. However, the present invention is not limited to this, and a general heat pump cycle using a refrigerant such as chlorofluorocarbon or alternative chlorofluorocarbon may be used.

  Moreover, in the above embodiment, the hot water storage tank 10 does not necessarily need to use a resin material, and may be shape | molded with a metal material. Moreover, the shape of the hot water storage tank 10 may not be a rectangular parallelepiped shape but may be a cylindrical shape, for example. In addition, although the hot water storage tank 10 is formed in an open air type, a hot water storage tank having a sealed type structure may be used. In this case, however, parts for protecting the tank such as a pressure reducing valve and a pressure relief valve are required.

It is a schematic diagram which shows the whole structure of the hot water storage type hot water supply apparatus in 1st Embodiment to which this invention is applied. It is a flowchart which shows the control processing of the boiling operation in 1st Embodiment of this invention. It is a flowchart which shows the control processing of the boiling operation in 2nd Embodiment of this invention. It is a flowchart which shows the control processing of the boiling operation in 3rd Embodiment of this invention. It is a schematic diagram which shows the whole structure of the hot water storage type hot water supply apparatus in other embodiment to which this invention is applied.

Explanation of symbols

10 ... Hot water storage tank 20 ... Heat pump unit (heating means)
DESCRIPTION OF SYMBOLS 21 ... Fluid heating path 25 ... Compressor 26 ... Heat storage heat exchanger 27 ... Expansion valve 28 ... Air heat exchanger 30 ... Hot water supply heat exchanger (heating heat exchanger)
30a ... 1st distribution part 30b ... 2nd distribution part 41 ... Hot water supply control part (control means)
42 ... Heat source control section (control means)
60 ... Heat exchanger for hot water supply (heat exchanger for heating)
60a ... 1st distribution part 60b ... 2nd distribution part

Claims (7)

A hot water storage tank (10) for storing heat storage fluid therein;
A fluid heating flow path (21) for sending the lowest heat storage fluid in the hot water storage tank (10) to the uppermost part in the hot water storage tank (10);
A heating means (20) provided in the fluid heating channel (21) for heating the heat storage fluid flowing through the fluid heating channel (21);
A heat exchanger (30, 60) for heating that heats the heat medium flowing in the secondary side by flowing the heat storage fluid in the hot water storage tank (10) to the primary side;
In a hot water storage type hot water supply apparatus comprising control means (41, 42) for controlling the heating means (20) based on the amount of hot water stored in the hot water storage tank (10) and performing a boiling operation,
The heat medium heated by the heating heat exchanger (30, 60) is hot water for supplying hot water to a hot water supply location or bath water for chasing bath water in a bathtub,
When the heating operation is in the energy saving mode, the control means (41, 42) is configured to set the hot water storage tank (10), the fluid heating temperature to one of the hot water supply set temperature and the reheat set temperature set by the user. A hot water storage system that performs a boiling operation based on a target boiling temperature obtained by adding heat loss (α) from the flow path (21) and the heat exchanger (30, 60) for heating. Hot water supply device.   The control means (41, 42) performs the boiling operation separately for a midnight time zone where the fee setting is low and a midnight time zone where the fee setting is high, and the target boiling temperature is a midnight time zone and a midnight time zone. The hot water storage type hot water supply apparatus according to claim 1, wherein the hot water storage type hot water supply apparatus is different from the above. The heating means (20) includes a heat pump cycle circuit including a compressor (25), a heat storage heat exchanger (26), an expansion valve (27), and an air heat exchanger (28).
The hot water storage type hot water supply apparatus according to claim 2, wherein the control means (41, 42) performs capacity control of the compressor (25) which is different between a midnight time zone and a time other than a midnight time zone.   The hot water storage type hot water supply apparatus according to any one of claims 1 to 3, wherein the target boiling temperature is about 65 ° C or less. The control means (41, 42) calculates the amount of heat used for hot water supply and replenishment from the hot water storage tank (10) within a unit period and stores the amount of heat used as data. (290),
An average usage heat amount calculating means (300) for calculating an average usage heat amount within a predetermined period from the accumulated usage heat amount data within the unit period;
A variation calorific value calculation means (310) for calculating a variation calorific value within a predetermined period from the accumulated data on the amount of heat used within the unit period;
Boiling based on the used heat amount accumulated by the used heat amount calculation means (290), the average used heat amount calculated by the average used heat amount calculation means (300), and the variation heat amount calculated by the variation heat amount calculation means (310). Boiling heat amount calculating means (330, 340) for calculating the amount of heat to be raised;
The second heating control means (350) for heating the heating means (20) based on the amount of heating heat calculated by the heating heat quantity calculation means (330, 340). The hot water storage type hot water supply apparatus according to any one of claims 1 to 4.   The heating heat exchanger (30, 60) is adjacent to the first circulation part (30a) through which the heat storage fluid in the hot water storage tank (10) circulates and the second circulation part (30b) through which the hot water supply water circulates. The hot water storage type hot water supply apparatus according to any one of claims 1 to 5, wherein the hot water storage fluid and the hot water supply water are configured to face each other.   The heating heat exchanger (30, 60) includes a third circulation part (60a) through which heat storage fluid in the hot water storage tank (10) circulates and a fourth circulation part (60b) through which bath water in the bathtub circulates. The hot water storage type hot water supply apparatus according to any one of claims 1 to 6, wherein the heat storage fluid and the bath water are configured to face each other. .

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