JP2019219109A - Hot water storage type water heater - Google Patents

Abstract

To resolve the problem that if the required sterilization temperature has not been reached after performing the sterilization operation, the sterilization operation must be performed again, and boiling all the hot water in a hot water storage tank 1 above the sterilizable temperature in the sterilization operation consumes a large amount of energy.SOLUTION: A hot water storage type water heater comprises calorie calculation means 40 for calculating the amount of heat required to bring all the hot water in hot water storage tank 1 to the sterilizable temperature, and the sterilization operation control means 39 is heated by heating means 24 at the first predetermined temperature until the required amount of heat is reached.SELECTED DRAWING: Figure 1

Description

  TECHNICAL FIELD The present invention relates to a hot water supply type hot water supply device that performs a sterilization operation in a hot water storage tank.

  Conventionally, in this type of hot water storage type hot water supply device, when the temperature in the hot water storage tank is lower than the sterilizable temperature (about 65 ° C.) for a predetermined time or more, the entire hot water storage tank is heated to a sterilizable temperature or higher. There was a hot-water storage type hot water supply device that had a sterilization operation to boil.

  Further, as shown in Patent Document 1, the sterilization operation includes a high-temperature heating step of boiling water in the hot-water storage tank until the detection temperature of the hot-water storage temperature sensor provided at the lower part of the hot-water storage tank reaches 45 ° C., and after the high-temperature heating step, It has a temperature equalization process that drives the heating circulation pump and stirs the hot water in the hot water storage tank. The tank is boiled in the high-temperature heating process, and the entire tank is sterilized to a sterilizable temperature in the temperature equalization process. There was a hot water storage type hot water supply device.

JP-A-2006-191493

  In the case of Patent Document 1, in the high-temperature heating step, if the detected temperature of the hot-water storage temperature sensor provided at the lower part exceeds 45 ° C., the temperature of the entire hot-water storage tank can be sterilized by stirring in the temperature equalization step. For example, if the medium-temperature water remains before the high-temperature heating step, the high-temperature heating step ends when the high-temperature heating step is performed in a short period of time, and even after stirring in the temperature uniforming step, the entire hot-water storage tank can be sterilized at a temperature that can be sterilized. However, there is a problem in that if the temperature does not reach the sterilizable temperature, the sterilization operation must be performed again, which wastes energy.

  In order to solve the above-mentioned problems, the present invention provides a hot water storage tank for storing hot water, heating means for heating hot water in the hot water storage tank, and hot water being circulated between the hot water storage tank and the heating means. Heating circulation circuit, a heating circulation pump for circulating hot water in the middle of the heating circulation circuit, a boiling temperature sensor for detecting the temperature of the hot water returning to the upper part of the hot water storage tank from the heating means, and a hot water storage tank. A plurality of hot water storage temperature sensors provided to detect a hot water storage temperature, a boiling operation for boiling a part of the hot water in the hot water storage tank to a first predetermined temperature higher than a sterilizable temperature, and after the boiling operation A hot-water storage type hot water supply device having a sterilization operation control means for controlling a sterilization operation for performing a stirring operation of stirring the hot water in the hot water storage tank by driving the hot water in the hot water storage tank by the heating circulation pump; In the above, there is provided a calorific value calculating means for calculating a calorific value necessary to bring all the hot water in the hot water storage tank to the sterilizable temperature, and the sterilizing operation control means comprises the first predetermined temperature until the required caloric value is reached. At the heating means.

  Further, a time calculating means for calculating a predicted time required to boil the necessary heat amount and counting the time is provided, and the sterilization operation control means, the time calculated by the time calculating means in advance until the predicted time elapses. It was made to boil by heating means.

  Further, the sterilization operation control means is configured to boil the heating means until the hot water storage temperature corresponding to the required amount of heat is detected.

  According to the present invention, the calorific value calculating means calculates the calorific value necessary for the sterilization operation from the hot water storage temperature, and the sterilizing operation control means boil-up the amount of calorie necessary for the calculated calorific value. Thus, it is possible to prevent wasteful energy of re-executing the sterilization operation due to lack of heat, and to prevent unnecessary boiling and unnecessary energy consumption.

Schematic diagram showing the configuration of one embodiment of the present invention Flow chart for explaining the operation of the sterilization operation of the same embodiment The figure which shows the relationship between the temperature which enters the heat pump of the embodiment, and the boiling COP.

  Next, a bath water heater according to an embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 is a schematic diagram showing a configuration of a bath water heater, wherein 1 is a hot water storage tank for storing hot water, 2 is a water supply pipe for supplying water to the bottom of the hot water storage tank 1, 3 is a hot water supply pipe for tapping water from the top of the hot water storage tank 1, and 4 is a water supply A water supply bypass pipe branched from the pipe 2, 5 is a hot water mixing valve for mixing hot water from the tapping pipe 3 and water from the water supply bypass pipe 4, and 6 is a connection between an outlet of the hot water mixing valve 5 and a hot water tap 7. A hot water supply pipe, 8 is a hot water supply flow rate sensor that detects a flow rate of hot water flowing through the hot water supply pipe 6, 9 is a hot water supply temperature sensor that detects a temperature of hot water flowing through the hot water supply pipe 6, and 10 is a temperature detector that detects the temperature of hot water flowing through the water supply bypass pipe 4. Supply water temperature sensor.

  11 is a bath mixing valve for mixing the hot water from the tapping pipe 3 and the water from the water supply bypass pipe 4, and 12 is a hot-water pipe for hot-watering the hot water from the bath mixing valve 11 to a bathtub 13 installed in the bathroom. Reference numeral 14 denotes a filling flow rate sensor for detecting the flow rate of hot water flowing through the filling pipe 12, reference numeral 15 denotes a filling temperature sensor for detecting the temperature of hot water flowing through the filling pipe 12, and reference numeral 16 denotes an open / close flow path of the filling pipe 12. A plurality of hot water filling electromagnetic valves, 17a to 17e are hot water storage temperature sensors provided at upper and lower sides of the hot water storage tank 1 to detect hot water storage temperature, and 17e is provided at a lower portion of the hot water storage tank 1 and controls a temperature of entering the heating means 24. Can be detected. Further, the temperature distribution of hot water in hot water storage tank 1 can be detected according to the detection values of hot water storage temperature sensors 17a to 17e.

  Reference numeral 18 denotes a bathtub heat exchanger for heating the bathtub water in the bathtub 13 and a bath heat exchanger 19 for circulating the bathtub water between the bathtub 13 and the bath heat exchanger 18. A bath circulation circuit, which is connected as possible, 20 is a bath circulation pump for sucking bath water in the bath 13 and pumping it to the bath heat exchanger 18 to circulate bath water, and 21 is for detecting the temperature of bath water. The bath temperature sensor 22 is a water level sensor that detects the water level in the bathtub 13 by detecting the water pressure, and the hot water pipe 12 is connected in the middle of the bath circulation circuit 19.

  A three-way valve 23 is provided in the middle of the bath circulation circuit 19 and is configured to be able to bypass the bath heat exchanger 18.

  24 is a heat pump type heating means for heating the hot water in the hot water storage tank 1, 25 is a heating circulation circuit connecting the hot water storage tank 1 and the heating means 24 so that the hot water can circulate, and 26 is a heating circulation pump for circulating the hot water. , 27 are an incoming water temperature sensor for detecting the incoming water temperature at which the water enters the heating means 24, and 28 is a heating temperature sensor for detecting the temperature of the hot water heated by the heating means 24. Here, the heat pump type heating means 24 includes a compressor 29, a water-refrigerant heat exchanger 30, an expansion valve 31, an air heat exchanger 32, a blower 33, and an outside air temperature sensor 34 for detecting outside air temperature. The boiling is performed so that the temperature detected by the boiling temperature sensor 28 becomes an arbitrary temperature in a range of 40 ° C. to 90 ° C.

  Reference numeral 35 denotes a remote controller (remote controller) provided outside the bathroom, which outputs a display section 35a as a notification section for notifying an operation state and a setting state of the water heater, and outputs previously stored voice data and notification sound. Speaker 35b, a bath switch 35c for starting bathing in the bathtub 13, a change switch 35d for changing a bath set temperature, and other switches 35e.

  Reference numeral 36 denotes a bathroom remote controller (remote controller) provided in the bathroom, a display unit 36a serving as a notification unit for notifying an operation state and a setting state of the hot water supply type water heater, and sound data and notification sound stored in advance. , A bath switch 36c for starting bathing in the bathtub 13, a change switch 36d for changing the bath set temperature, other switches 36e, and a bathroom for detecting the room temperature in the bathroom. And a temperature sensor 37.

  38 is a main body control means for controlling the operation of the storage type hot water supply apparatus, and includes a hot water supply flow sensor 8, a hot water supply temperature sensor 9, a water supply temperature sensor 10, a hot water flow sensor 14, a hot water temperature sensor 15, a hot water storage temperature sensor 17, The detection values of the bath temperature sensor 21, the water level sensor 22, the outside air temperature sensor 34, and the bathroom temperature sensor 37 are input, and the hot water supply mixing valve 5, the bath mixing valve 11, the hot water filling electromagnetic valve 16, the bath circulation pump 20, and the heating means 24 The remote controller 35 controls the operation and is connected to the remote controller 35 outside the bathroom and the remote controller 36 in the bathroom so that necessary information can be transmitted and received. Here, the main body control means 38 has a logic circuit such as an MPU and controls the operation according to a program stored in advance while referring to a memory.

  When the main body control means 38 determines that at least a part of the hot water in the hot water storage tank 1 has remained for a predetermined time or more, all the hot water in the hot water storage tank 1 is equal to or higher than a sterilizable temperature at which Legionella bacteria are sterilized (here, 65). This is a sterilization operation control means for controlling a sterilization operation in which the temperature rises to (° C. or more).

  Numeral 40 is a calorie calculating means for calculating a calorie required for the sterilization operation. The required calorie is calculated based on a detection value of the hot water storage temperature sensor 17. A boiling operation is performed by the heating means 24 until the required heat amount calculated in the above is secured, and a stirring operation for stirring the inside of the hot water storage tank 1 after the boiling operation to make the temperature in the hot water storage tank 1 uniform is performed.

  Further, the sterilization operation control means 39 performs the boiling operation at a first predetermined temperature (here, 90 ° C.) in which the boiling temperature of the boiling operation of the sterilization operation is higher than the sterilizable temperature. The boiling at the first predetermined temperature is for keeping the water not heated by the heating means 24 as much as possible in the hot water storage tank 1, and for stirring the hot water and the unheated water after the boiling operation. A higher boiling temperature can leave more unheated water.

  Explaining a specific calculation example, the hot water storage tank 1 can store 370 L of hot water, and the lowest level of hot water stored in the hot water storage tank 1 that enters the heating means 24 detected by the hot water storage temperature sensor 17 e is 24 ° C. In the case of 250 L, the calorie calculation means 40 determines that 140 L of water at 24 ° C. (37.9% of the total amount) and 230 L of water at 90 ° C. (first predetermined temperature higher than the sterilizable temperature) (62.1%), it is calculated that the entire hot water storage tank 1 can be made 65 ° C. hot water by stirring the 24 ° C. water and 90 ° C. water in the hot water storage tank 1 with the heating circulation pump 26. Then, the sterilization operation control means 39 heats the hot water in the hot water storage tank 1 to 90 ° C. by 230 L by the heating means 24.

  Then, the sterilization operation control means 39 ends the boiling operation when the heating heat amount reaches the predetermined heat amount achievement condition, starts the stirring operation by the heating circulation pump 26, and can sterilize all the hot and cold water in the hot water storage tank 1. Temperature.

The above-mentioned predetermined heat amount achieving condition will be described in detail.
The predetermined heat amount achievement condition determines whether the heat amount in the hot water storage tank 1 has reached the required heat amount calculated by the heat amount calculation means 40.

  Reference numeral 41 denotes a time calculating means for calculating a predicted time required for boiling the necessary calorie calculated by the calorie calculating means 40, and by dividing the heating capacity of the heating means 24 from the required calorie calculated by the calorie calculating means 40. Calculate the estimated time required to boil the required heat.

  Specifically, the time calculating means 41 calculates a predicted time required for boiling the necessary heat quantity by dividing the heating capacity of the heating means 24 from the necessary heat quantity calculated by the heat quantity calculating means 40, 41 starts a timer count at the start of the boiling operation, and when the predicted time elapses, the sterilization operation control means 39 determines that a predetermined heat quantity achievement condition is satisfied.

  Next, the operation of the bath water heater of the present invention will be described.

<Boiling operation>
When the start time of the predetermined time zone (midnight time zone) where the unit price of electric power is low is reached, the main body control means 38 instructs the heating means 24 to supply the hot water load to the heating means 24 so as to start boiling the hot water corresponding to the hot water load. The heating means 24 starts driving the compressor 29, the expansion valve 31, the blower 33, and the heating circulation pump 26, and the hot water taken out from the lower part of the hot water storage tank 1 is transmitted. The water is heated to the boiling target temperature in the water-refrigerant heat exchanger 30 and returned to the upper portion of the hot water storage tank 1, and the hot water of the set temperature is stored in a stacked form from the upper portion of the hot water storage tank 1. When boiling to the lower part or when the end time of the predetermined time zone is reached, the heating means 24 is instructed to stop boiling, and the heating means 24 supplies the compressor 29, the expansion valve 31, the blower 33, and the heating circulation pump 2. To exit the boiling operation to stop driving.

<Hot water supply>
When the hot water tap 7 is opened, city water flows into the bottom of the hot water storage tank 1 from the water supply pipe 2, and high-temperature hot water flows out of the top of the hot water storage tank 1 through the hot water supply pipe 3. The water is mixed with the water from the pipe 4 and passes through the hot water supply pipe 6. When the hot water supply flow sensor 8 detects the minimum operating water amount or more, the main body control means 38 feedback-controls the valve opening of the hot water supply mixing valve 5 so that the temperature detected by the hot water supply temperature sensor 9 matches the set hot water supply temperature. Then, hot water is supplied at the set hot water temperature. Then, when the hot water supply flow sensor 8 detects less than the minimum operating water amount, such as when the hot water tap 7 is closed, the main body control means 38 stops the feedback control of the valve opening of the hot water mixing valve 5 to stop hot water supply. ing.

<Tunneling operation>
When the main body control means 38 instructs the filling, the filling electromagnetic valve 16 is opened, and the bath mixing is performed so that the temperature detected by the filling temperature sensor 15 matches the filling temperature instructed by the main control means 38. The valve opening of the valve 11 is feedback-controlled to start filling at the designated filling temperature and supply the bath to the bathtub 13.

  When the integrated value of the hot water flow detected by the hot water flow sensor 14 detects the bath set amount or the water level sensor 22 detects the bath set water level, the main body control means 38 closes the hot water electromagnetic valve 16 and closes the hot water. End tensioning operation

<Reheating operation>
The remaining water remains in the bathtub 13 by detecting the water pressure by detecting the water pressure by the water level sensor 22, and the main body control means 38 drives the bath circulation pump 20 to supply the bath water to the bath circulation circuit 19 and the bath heat exchanger 18. And the bath water is heated by the bath heat exchanger 18. When the bath temperature sensor 21 confirms that the temperature of the bath water has risen to the bath set temperature, the driving of the bath circulation pump 20 is stopped.

<Heat keeping operation>
Further, in the bath heat retention operation, the bath circulation pump 20 is driven at regular intervals, the bath temperature sensor 21 checks the temperature of the bath water, and when it is detected that the temperature is lower than the bath set temperature, circulation is continued. The bath water is heated by the bath heat exchanger 18. Then, when the bath temperature sensor 21 confirms that the temperature of the bath water has risen above the bath set temperature, the drive of the bath circulation pump 20 is stopped.

  Further, the main body control means 38 stores the water level in the bathtub 13 at the time of stopping the filling, based on the detection value of the water level sensor 22, and when the water level in the bathtub 13 drops from the stored water level, the water level until the water level returns to the original level. Perform water refilling operation with hot water.

  Then, when a preset bath heat retention time has elapsed from the start of hot water filling, the bath heat retention operation and the bath rehydration operation are also stopped, and the bath heat retention operation is stopped.

<Sterilization operation>
Next, the sterilization operation of the first embodiment will be described based on the flowchart shown in FIG.
If all the hot water in the hot water storage tank 1 is not used within the predetermined time and at least a part of the hot water remains in the hot water storage tank 1 for a predetermined time or more (S1 is Yes), the entire amount of hot water in the hot water storage tank 1 can be sterilized. (Here, 65 ° C.) or more to start a sterilization operation for preventing the propagation of Legionella bacteria (S2).

  First, the sterilization operation control means 39 detects the lowest hot water storage temperature and the temperature distribution of the hot water storage tank 1 of the hot water storage tank 1 entering the heating means 24 from the hot water storage temperature sensor 17e (S3), and detects the hot water storage temperature detected by the hot water storage temperature sensor. The calorific value calculating means 40 calculates the required heat quantity so that the temperature inside the hot water storage tank 1 becomes 65 ° C. or more when the hot water in the hot water storage tank 1 is stirred and mixed from the temperature (S4). Is changed to the first predetermined temperature (here, 90 ° C.) (S5).

  Further, the time calculating means 41 calculates a predicted time required to boil the required calorific value calculated by the calorific value calculating means 40, and determines a predicted time (S6).

  Then, the sterilization operation control unit 39 starts the boiling operation, and the time calculation unit 41 starts timer counting until the estimated time is reached (S7).

  At this time, if the water is heated to the sterilizable temperature (here, 65 ° C.) to the lower portion of the hot water storage tank 1 and heated until the hot water storage temperature sensor 17e detects the sterilizable temperature (here, 65 ° C.), as shown in FIG. As a result, the temperature at which water enters the heating means 24 increases, and the boiling COP (boiling efficiency) decreases.

  As described above, the sterilization operation control unit 39 calculates the required heat amount by the heat amount calculation unit 40, and ends the boiling operation at an appropriate timing such that unheated water remains in the hot water storage tank 1, whereby the water input is started. The boiling operation can be terminated while maintaining a relatively low temperature and a high boiling COP (boiling efficiency), and a sterilizing operation excellent in energy saving can be performed.

  In addition, the temperature at which water enters the heating means 24 is increased, so that the evaporation temperature of the refrigerant is increased, and the pressure of the refrigerant circuit is increased, thereby burdening the refrigerant circuit and reducing the durability. When the amount of heat necessary for the entire hot water storage tank 1 to reach 65 ° C. or more is secured, the boiling operation is stopped, so that the temperature at which water enters the heating means 24 can be prevented from increasing.

  Then, the boiling operation is started, and it is confirmed by the time calculating means 41 whether or not the predicted time calculated by the time calculating means 41 has elapsed (S8). When the timer count of the time calculating means 41 reaches the predicted time (S8). Yes), the sterilization operation control means 39 determines that the calorific value calculated by the calorific value calculating means 40 has been boiled, and ends the boil-up operation (S9).

  Next, the sterilization operation control means 39 starts the stirring operation (S10), drives the heating circulation pump 26 (S11), and transfers the water at the lower part of the hot water storage tank 1 to the upper part of the hot water storage tank 1 via the heating circulation circuit 25. The water flows vigorously, and the hot water in the hot water storage tank 1 is stirred.

  Thereafter, the sterilization operation control unit 39 checks whether the detected temperature of the boiling temperature sensor 28 is equal to or higher than 65 ° C. (S12), and when the detected temperature of the boiling temperature sensor 28 is equal to or higher than 65 ° C. (Yes in S12), The driving of the heating circulation pump 26 is stopped (S13), and the stirring operation is ended (S14), thereby terminating the sterilization operation (S15).

  In this way, the calorific value calculating means 40 calculates the necessary heat quantity so that the hot water in the hot water storage tank 1 becomes 65 ° C. or more when agitated, and the water is heated at a relatively low temperature at which the water enters the heating means 24. Can be completed, the boiling COP (boiling efficiency) is high, sterilization operation excellent in energy saving is possible, and the calorie calculation means 40 calculates the required heat amount before the sterilization operation starts. Therefore, it is possible to suppress wasteful energy consumption of performing the sterilization operation again because the sterilizable temperature has not been reached after the sterilization operation.

  In addition, since the temperature of water entering the heating means 24 increases and the boiling operation is stopped before the boiling COP (boiling efficiency) decreases, the temperature of water entering the heating means 24 increases and the evaporation temperature of the refrigerant increases. Therefore, it is possible to prevent the refrigerant circuit from being damaged due to an increase in the pressure of the refrigerant circuit and an increase in the pressure of the refrigerant circuit.

  Note that the present invention is not limited to the present embodiment, and does not prevent modification within a scope that does not change the gist. For example, detection of a temperature at which water enters when the heating circulation pump 26 is not driven is Although the hot water storage temperature sensor 17e provided in the lower part of the hot water storage tank 1 is used, the temperature of incoming water may be detected by driving the heating circulation pump 26 and the incoming water temperature sensor 27.

  It is important that hot water is stored in the hot water storage tank 1 by the necessary amount of heat calculated by the heat amount calculating means 40. The predetermined heat amount achieving condition is that the boiling operation is performed until the predicted time calculated by the time calculating means 41 elapses. Alternatively, the boiling operation may be performed to a heat amount corresponding to the hot water storage temperatures detected by the hot water storage temperature sensors 17a to 17e.

  Further, the boiling temperature, the boiling temperature in this embodiment is a first predetermined temperature of 90 ℃ is performed a boiling operation, but is not limited to this temperature, the boiling temperature, The calorific value calculation may be performed so as to leave unheated water in the lower part of the hot water storage tank 1, and the boiling temperature may be reduced to 90 ° C. or less.

  Further, the predetermined heat amount achievement condition is to calculate the heat amount from the temperature distribution of the hot water stored in the hot water storage tank 1 in accordance with the detection values of the temperatures detected by the plurality of hot water storage temperature sensors 17 provided on the side surface of the hot water storage tank 1. Then, when the heat amount according to the detection value of the hot water storage temperature sensor 17 reaches the required heat amount calculated by the heat amount calculation unit 40, the sterilization operation control unit 39 may determine that the predetermined heat amount achievement condition is satisfied.

1 Hot Water Storage Tank 17 Hot Water Storage Temperature Sensor 24 Heating Means 25 Heating Circulation Circuit 26 Heating Circulation Pump 28 Boiling Temperature Sensor 38 Main Body Control Means (Control Means)
39 sterilization operation control means 40 heat quantity calculation means 41 time calculation means

Claims (3)

A hot water storage tank for storing hot water, heating means for heating the hot water in the hot water storage tank, a heating circulation circuit in which the hot water storage tank and the heating means are connected so that hot water can circulate, and a heating circulation circuit A heating and circulating pump for circulating hot and cold water, a boiling temperature sensor for detecting the temperature of hot water returning from the heating means to the upper portion of the hot water storage tank, and a hot water storage temperature provided in the hot water storage tank for detecting the hot water storage temperature; A sensor, a boiling operation for boiling a part of the hot water in the hot water storage tank to a first predetermined temperature higher than a sterilizable temperature, and, after the boiling operation, the heating and circulation of the hot water in the hot water storage tank. In a hot water supply type hot water supply device provided with a sterilization operation control means for controlling a sterilization operation for performing a stirring operation of stirring hot water in the hot water storage tank by driving a pump,
A calorific value calculating means for calculating a calorific value required to bring all the hot water in the hot water storage tank to the sterilizable temperature is provided, and the sterilizing operation control means sets the heat at the first predetermined temperature until the required caloric value is reached. A hot-water storage type hot water supply device characterized by being heated by heating means. Providing a time calculation means for calculating the estimated time required to boil the required heat and counting the time,
2. The hot water supply apparatus according to claim 1, wherein said sterilization operation control means causes the heating means to boil until the predicted time calculated by the time calculation means in advance elapses. 2. The hot water supply type hot water supply apparatus according to claim 1, wherein the sterilization operation control means is configured to boil the hot water by the heating means until the hot water storage temperature corresponding to the required amount of heat is detected.

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