JPH1089766A - Water heater - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make not only power demand in one day uniform but also power demand in a midnight power service time zone uniform by grasping a start time of power service obtained by subtracting a power service necessary time from a midnight power service time zone finishing time, and starting conducting to a heating means based on the grasped start time. SOLUTION: An electric heater conducting time is calculated from a boiling heat value and heating capacity of an electric heater 10, and an electric heater conducting time is subtracted from a midnight power service time zone finishing time, and a conducting time starting time is calculated. Further, a heat pump water heating time is calculated from boiling heat value and its heating capacity of a heat pump system 4. A heat pump water heating time is subtracted from an electric heater conducting starting time, a heat pump hot water supply starting time is calculated, and conducting starting time to a heating time is grasped. Accordingly, the conducting starting time is shifted to an early morning side to contribute to uniform power demand in the midnight power time zone.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hot water supply device provided with a heating means operated by midnight power.

[0002]

2. Description of the Related Art In order to supply power stably, it is necessary to provide a power supply capable of responding to peak power demand. Therefore, in order to supply power stably, it is desirable to equalize the power demand. However, the power demand is not uniform even during the day, and generally tends to be large during the daytime but small from late night to early morning. The power demand becomes the smallest in the “midnight power time zone”, which is mainly the time zone of 11:00 PM to 7:00 PM. Therefore, a hot water supply device configured to perform a hot water supply heating operation during the midnight power time period and store the heated hot water until use is used (for example, Japanese Patent Application Laid-Open No.
0-30944).

FIG. 4 is a schematic view showing the above-mentioned conventional hot water supply apparatus. In the figure, reference numeral 31 denotes a hot water storage tank;
Is an electric heater provided below the hot water storage tank 31. Reference numeral 33 denotes a heat pump system, which includes a compressor 34 and a hot water supply heat exchanger 3 functioning as a condenser.
5, an expansion mechanism 36 and an evaporator 37 are provided. Further, a suction pipe 38 having a circulation pump 40 interposed and a discharge pipe 39 are connected to the lower side surface of the hot water storage tank 31.
1 is circulated through the hot water supply heat exchanger 35. In the figure, reference numeral 41 denotes a water supply pipe, and reference numeral 42 denotes a hot water supply pipe.

In the above-described conventional hot water supply apparatus, first, a time required for heating is obtained based on the heating capacity of the heat pump system 33 and the heating capacity of the electric heater 32. When the time required for heating is shorter than the length of the late-night power time zone, that is, 8 hours, the hot-water supply operation is performed by the heat pump system 33 simultaneously with the entry of the late-night power time zone to heat the hot water to a predetermined heat pump boiling temperature. Then, the electric heater 32 is energized to perform heating up to the boiling temperature. On the other hand, when the time required for heating is longer than the above 8 hours,
Heat pump system 33 at the same time as midnight power hours
And the electric heater 32 is energized at the same time for a required time, so that the hot water in the hot water storage tank 31 is boiled in the midnight power time zone. According to the above-described conventional hot water supply apparatus, the power can be consumed during the late night power hours when the power demand is small, and the hot water in the hot water storage tank 31 can be boiled, thereby making the power demand uniform.

[0005]

However, even within the midnight power hours, the power demand is not uniform. Immediately after the start of this time zone (around 11:00 PM), the power demand is relatively large, but tends to decrease as early in the morning. Has become. Therefore, in order to further equalize the power demand in the midnight power time zone, it is important to shift the power consumption of the device to the early morning side in the midnight power time zone as much as possible.

However, in the above hot water supply apparatus, since the control is performed such that the hot water supply operation is performed by the heat pump system 33 or the electric power is supplied to the electric heater 32 at the same time as entering the midnight power time zone, it is considered that the power demand is still relatively large. Near the start time of the late night power time zone (PM 11: 0
(Around 0), there is a problem that it is difficult to contribute to uniform power demand during the midnight power hours.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned conventional drawbacks, and has as its object not only the equalization of power demand within a day, but also the power demand in the midnight power hours. It is an object of the present invention to provide a hot water supply device that can contribute to uniformity of the hot water supply.

[0008]

Therefore, the hot water supply apparatus according to the first aspect of the present invention includes heating means 4 and 10,
0 is operated by midnight electric power to boil the hot water in the hot water storage tank 1 to the first set temperature in the hot water supply apparatus.
Based on the heating capacity of 0, the necessary power supply time to the heating means 4 and 10 is grasped, and the power supply start time is grasped by subtracting the required power supply time from the end time of the midnight power time zone,
It is characterized in that energization of the heating means 4, 10 is started based on this energization start time.

In the hot water supply apparatus of the first aspect, the heating means 4, 10 are operated by the midnight electric power, and at this time, the start time of energizing the heating means 4, 10 is shifted to the early morning side in the midnight electric power time zone. ing. Therefore, by using the late-night power, it is possible to not only equalize the power demand within one day, but also to contribute to the equalization of the power demand during the late-night power time zone.

Further, in the hot water supply apparatus, the heating means 4 and 10 heat the hot water in the hot water storage tank 1 to a second set temperature, and heat the hot water to a temperature higher than the second set temperature. And a heat pump system 4 for heating the hot water in the hot water storage tank 1 up to the second set temperature.

[0011] In the hot water supply apparatus according to the second aspect, by using appropriate heating means 4, 10 in accordance with the temperature of hot water,
The running cost can be reduced.

Further, in the hot water supply apparatus of the third aspect, if the grasped energization start time is earlier than the current time in the midnight power time zone, the electric heater 10 is connected to the heat pump system 4 until the second set temperature. Hot water storage tank 1
It is characterized by heating the hot water inside.

According to the third aspect of the present invention, the hot water in the hot water storage tank 1 can be reliably heated during the midnight power time zone.

[0014] In the hot water supply apparatus according to a fourth aspect of the present invention, the energization start time is repeatedly determined at predetermined time intervals.

In the hot water supply apparatus according to the fourth aspect, it is possible to know the exact energization start time according to the use of the hot water in the hot water storage tank 1 and its temperature drop. Therefore, the hot water in the hot water storage tank 1 can be surely boiled in the midnight power time zone, and it is possible to improve the use comfort.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, a specific embodiment of the hot water supply apparatus of the present invention will be described in detail with reference to the drawings. FIG. 1 is a schematic diagram showing the entire configuration of the hot water supply apparatus. In the figure, 1 is a closed type hot water storage tank,
The upper end of the hot water storage tank 1 is connected to a hot water supply pipe 2, and the lower end is connected to a water supply pipe 3. When the callan (not shown) at the end of the hot water supply pipe 2 is opened, the hot water stored in the hot water storage tank 1 is sequentially pushed up from the upper side by the pressure of the tap water acting through the water supply pipe 3. Is supplied to the hot water supply pipe 2. The hot water storage tank 1
Those having an internal capacity capable of substantially storing the amount of daily hot water are selected.

The bottom of the hot water storage tank 1 has a pump 1
3 is provided with a hot water circulation path 14, and a hot water supply heat exchanger 5 which is a component of the heat pump system 4 is disposed in the hot water circulation path 14. The heat pump system 4 further includes a compressor 6,
It has an air heat exchange type evaporator 7 and an expansion mechanism 8, and these devices 6, 7, 8 and the hot water supply heating heat exchanger 5 are connected by refrigerant pipes 9, 9 so that refrigerant can circulate. I have. By driving the compressor 6 of the heat pump system 4 and operating the pump 13 of the hot water circulation path 14,
The configuration is such that the hot water in the hot water storage tank 1 is heated by the refrigerant condensation heat in the hot water supply heating heat exchanger 5. When the hot water in the hot water storage tank 1 is heated by the heat pump system 4, for example, heating to 65 ° C. is possible.

An electric heater 10 is further provided on the bottom side in the hot water storage tank 1.
With 0, the hot water in the hot water storage tank 1 can be heated. When the hot water in the hot water storage tank 1 is heated by the electric heater 10, the hot water can be heated to a temperature higher than the heating upper limit temperature in the heat pump system 4, for example, 85 ° C. That is, in this hot water supply apparatus, the heat pump system 4 and the electric heater 10 function as heating means for heating hot water in the hot water storage tank 1.

On the side wall surface of the hot water storage tank 1, five hot water temperature sensors 11a to 11e are provided from the upper side to the lower side.
Is attached. And these five hot water temperature sensors 11a
11e, the inside of the hot water storage tank 1 is divided into five and the hot water temperature is detected. In the vicinity of the evaporator 7, an outside air temperature sensor 12 composed of a thermistor for detecting the outside air temperature is provided.

The detection signals of the sensors 11a to 11e and 12 are input to a CPU 21 functioning as a heating operation control unit. The CPU 21 has a function of selecting a more appropriate heating operation mode from each input detection signal and issuing a heating command to the heat pump system operation control unit 22 and the electric heater operation control unit 23.
The details will be described later. When a heating command is input to the heat pump system operation control unit 22, the operation of the compressor 6, the operation of a fan (not shown) attached to the evaporator 7, and the operation of the heat pump system operation control unit 22 are performed. Pump 13 of hot water circulation circuit 14
Is started, and the heating operation by the heat pump system 4 is performed. When a heating command is input to the electric heater operation control unit 23, the electric heater operation control unit 23
As a result, power is supplied to the electric heater 10 and the heating operation by the electric heater 10 is performed.

The heating command in the CPU 21 is set to a boiling temperature (first set temperature) set by a user using the remote controller 25 or the like or a second set temperature set in advance as a heating upper limit temperature in the heat pump system 4. The temperature (65 ° C.) is compared with the detected hot water temperature, and the operation is started based on the electric heater energization start time and the heat pump system operation start time, which are grasped by comparing and discriminating the operation capability previously stored in the memory 24. Can be Therefore, C
Regarding the grasp of each time described above performed in PU21,
This will be described with reference to the flowchart of FIG.

When the CPU 21 knows from the input from a timer (not shown) that the time has reached 11:00 PM and has entered the midnight power time zone, it starts the routine shown in FIG. First, in step S1, the hot water temperature sensor 11a
Enter the detected temperature from ～11E, the boiling heat Q _A by the electric heater 10 is calculated as the number 1 as the sum of each segment.

(Equation 1) However, when the detected temperature _n is lower than the second set temperature, the calculation is performed using the detected temperature _n as the second set temperature. This is because, in principle, the electric heater 10 is used when heating hot water having a temperature equal to or higher than the second set temperature.

[0023] Next, in step S2, from the above boiling heat Q _A and heating capacity of the electric heater 10, the electric heater energization time T _A is calculated as follows. T _A = Q _A / electric heater heating capacity Here, the electric heater heating capacity is proportional to the outside air temperature, and is stored in the memory 24 in correspondence with the outside air temperature. The outside air temperature is input from the outside air temperature sensor 12 and the electric heater heating capacity according to the input value is stored in the memory 2.
4 and used. Next, in step S3, midnight is power consumption period end time AM7: 00 to calculate the electric heater energization start time by subtracting the electric heater energization time T _A from.

Further, in step S4, the heat pump hot water supply operation time T _{B is determined based on the} amount of heat Q _B to be heated by the heat pump system 4 and the heating capacity of the heat pump system 4.
Is calculated. Heat Q _B boiling this time is calculated by the case as well as the number 2 of the electric heater 10.

(Equation 2)

[0025] In this case the detected temperature _n is higher than the second set temperature to calculate the temperature detected _n as a second set temperature.
Because, in such a case, the heat pump system 4
Is not performed. Regarding also the heat pump hot water supply operation time T _B, calculated by the case as well as following equation T _B = Q _B / heat pump heating capacity of the electric heater 10. Here, since the heat pump heating capacity depends on the outside air temperature, the heating operation status, and the hot water temperature, these are stored as parameters in the memory 24 in advance in a matrix, and the outside air temperature sensor 12, the hot water temperature sensors 11a to 11a to
The corresponding heat pump heating capacity is read out and used according to the input value from 11e or the like. In step S5, by subtracting a heat pump hot-water supply operation time T _B from the electric heater energization start time, to calculate the heat pump hot water supply operation start time. Therefore, the start time of the heat pump hot water supply operation is the start time of energization to the heating means including the electric heater 10 and the heat pump system 4. By the steps S6 and S7, the steps S1 to S5 are executed every 10 minutes until 7:00 AM when the midnight power time zone ends, and the electric heater energization start time and the heat pump hot water supply operation start time are repeatedly grasped. .

Based on the heat pump hot water supply operation start time and the electric heater energization start time grasped as described above, the water heater operates as follows. When the CPU 21 knows that the current time has reached the heat pump hot water supply operation start time according to the input from the timer, the CPU 21 issues a heating command to the heat pump system control unit 22, and the heat pump system control unit 22 transmits the heat command to the hot water supply heat exchanger 5.
To start heating the hot water. And the electric heater energization start time heat pump hot-water supply operation time T _B has elapsed since the heat pump starting time, hot water in the hot water tank 1 is boiling in the second set temperature. Next, when the CPU 21 knows that the electric heater energization start time has come, the CPU 21
Reference numeral 21 issues a heating command to the electric heater controller 23 and issues a stop command to the heat pump system controller 22. In accordance with this, the electric heater control unit 23 controls the electric heater 1
0 and the heat pump system controller 2
2 stops the hot water supply operation by the heat pump system 4. The electric heater energization time T _A has passed from the electric heater energization start time AM7: 00, the hot water storage tank 1
The hot water in the inside is heated to the first set temperature.

By the way, the hot water in the hot water storage tank 1 may be used even after the midnight power hours. In such a case, the heat pump hot water supply operation start time and the electric heater energization start time greatly change before and after use. Therefore, in the above hot water supply apparatus, the heat pump hot water supply operation start time and the electric heater energization start time are repeatedly grasped every 10 minutes. If the time has come before, the boiling operation to the first set temperature at 7:00 AM cannot be completed by the above operation. Therefore, in such a case, the operation shown in FIG. In the figure, point A 'indicates the grasped start time of the heat pump hot water supply operation, point A indicates the current time, and point C indicates the electric heater energization start time. First, the hot water supply operation by the heat pump system 4 is started from the time point A when it is determined that the heat pump hot water supply operation start time is earlier than the current time, and the operation of the heat pump system 4 alone is performed up to the point B. Further, the power supply start time to the electric heater 10 is advanced to the point B,
From the point to the point C, both the hot water supply operation by the heat pump system 4 and the energization to the electric heater 10 are performed. Then, from the point C to the point D at which the temperature of the hot water reaches the second set temperature, the electric heater 10 alone performs heating, and at 7:00 AM, the heating to the first set temperature is completed.

On the other hand, when the grasped electric heater energization start time is earlier than the current time, both the hot water supply operation by the heat pump system 4 and the energization to the electric heater 10 are started from the current time (not shown). However, at this time, in some cases, it may not be possible to complete the heating up to the first set temperature at the end of the midnight power time zone.

[0029] In the configured water heater which is controlled as described above, by the time the midnight power time zone is finished subtracting an electric heater energization time T _A and the heat pump hot-water supply operation time T _B, the electric heater 10 and the heat pump system 4 The start time of energization to the heating means constituted by the above is grasped. Therefore, the electric heater energizing time T _A
That the when the sum of the heat pump hot water supply operation time T _B is less than 8 hours will be energized start time is shifted to the early side, thereby contributing to uniformity of power demand in the midnight power time zone it can. And since it is possible to contribute to the equalization of the power demand in this way, the power rate is also subject to the power supply control discount, and the running cost can be reduced. Heat pump system 4
A second set temperature is provided as a heating upper limit temperature in the above. In principle, boiling is performed by the heat pump system 4 up to the second set temperature, and further heating is performed by the electric heater 1.
0 is set. Therefore, by selecting and using an appropriate heating means according to the hot water temperature, the running cost can be further reduced. Furthermore, since the above-mentioned energization start time is repeatedly grasped every 10 minutes, even when the hot water in the hot-water storage tank 1 is used or the temperature drops during the midnight power hours, an accurate energization corresponding to these is performed. The start time can be grasped. If the grasped energization start time is earlier than the current time due to the use of hot water or the like, the electric heater 10 is used for heating to the second set temperature.
Is used together, it is possible to surely raise the temperature to the first set temperature by 7:00 AM when the midnight power time zone ends. In addition, in the above hot water supply device, the boiling is completed at the end of the midnight power time zone, so that the hot water storage time until the hot water is used is shortened, and thus the temperature drop due to heat radiation is reduced, so that the use comfort can be improved.

Although the specific embodiments of the present invention have been described above, the present invention is not limited to the above embodiments, and can be implemented with various modifications within the scope of the present invention. For example, when the grasped heat pump hot water supply operation start time is earlier than the current time, the control shown in FIG. 3B may be performed instead of the control shown in FIG. That is, from the present time A, both the hot water supply operation by the heat pump system 4 and the energization to the electric heater 10 are performed, and the electric heater 10 alone is heated from the point E at which the temperature of the hot water reaches the second set temperature. In this case, the boiling up to the first set temperature is completed at the point F before 7:00 AM. Considering the running cost, the control shown in FIG. 3A, in which the hot water supply operation by the heat pump system 4 is longer, is more advantageous. However, according to this method, the control can be simplified. In the above description, the boiling heat amounts Q _A and Q _B , the electric heater energizing time T _{A, the} heat pump hot water supply operation time T _{B, and the} like are ascertained by calculation, but from the memory 24 stored in advance in association with various parameters. You may make it read and grasp | ascertain.

[0031]

According to the first aspect of the present invention, the heating means is operated by the midnight electric power, and at that time, the power supply start time to the heating means is shifted to the early morning side in the midnight electric power time zone. Therefore, by using midnight power, not only can the power demand be equalized within a day,
Further, it is possible to contribute to the equalization of power demand during the midnight power hours.

Further, in the hot water supply apparatus of the second aspect, it is possible to reduce the running cost by using an appropriate heating means according to the temperature of the hot water.

Further, in the hot water supply device of the third aspect, it is possible to surely boil the hot water in the hot water storage tank during the midnight power time zone.

In the hot water supply apparatus according to the fourth aspect, it is possible to accurately determine the use time of the hot water in the hot water storage tank and the start time of energization according to the temperature drop, and to surely boil the hot water in the hot water storage tank during the midnight power hours. It is possible to improve the use comfort.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing an overall configuration of an embodiment of a hot water supply apparatus of the present invention.

FIG. 2 is a flowchart showing control performed by a CPU of the water heater.

FIG. 3 is a graph showing control performed by the CPU.

FIG. 4 is a schematic view showing a conventional hot water supply apparatus.

[Explanation of symbols]

 1 Hot water storage tank 4 Heat pump system 10 Electric heater

Continuation of the front page (72) Inventor Masazo Hoga 1000-2, Oya, Okamoto-cho, Kusatsu-shi, Shiga Daikin Industries, Ltd. Shiga Works (72) Inventor Atsushi Matsubara 1000-2, Oya, Okamoto-cho, Kusatsu-shi, Shiga Daikin Industries, Ltd.

Claims (4)

[Claims] 1. Heating means (4) and (10) are provided, and the heating means (4) and (10) are operated by electric power at midnight to boil the hot water in the hot water storage tank (1) to a first set temperature. In the configured hot water supply apparatus, the required time for energization of the heating means (4) (10) is grasped based on the amount of heat required for the boiling and the heating capacity of the heating means (4) (10), and the time of the late-night power hours A hot water supply apparatus characterized in that the required time for energization is subtracted from an end time to determine an energization start time, and that energization to the heating means (4) (10) is started based on the energization start time. The heating means (4) (10) heats hot water in the hot water storage tank (1) to a second set temperature, and heats the hot water to a temperature higher than the second set temperature. A second electric heater (10)
The hot water supply apparatus according to claim 1, wherein the hot water in the hot water storage tank (1) is heated mainly using the heat pump system (4) until the set temperature is reached. 3. If the grasped energization start time is earlier than the current time during the midnight power time zone, the electric heater (10) is used in combination with the heat pump system (4) until the second set temperature. The hot water supply device according to claim 2, wherein hot water in the hot water storage tank (1) is heated. 4. The apparatus according to claim 1, wherein the energization start time is repeatedly determined at predetermined time intervals.
The hot water supply device according to claim 3.