JP2017089970A - Electrically-driven water heater and boiling-up method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrically-driven water heater and a boiling-up method capable of boiling-up hot water through utilization of surplus electrical power generated by an independent electric power plant.SOLUTION: An electrically-driven water heater 10 comprises a hot water storing tank 11; heating means 12 for boiling-up hot water in the hot water storing tank 11 by standard heating capability utilizing non-utility electric power got by non-utility generation device 14 or high heating capability generating higher calorie than the standard heating capability and for boiling up hot water in the hot water storing tank 11 by the standard heating capability utilizing external electrical power supplied from commercial power generating facility 16; and control means 13 getting a value of surplus electric power of the non-utility power generating power from an outside 22 to cause the heating means 12 to perform a boiling-up of hot water in the hot water storing tank 11 with the high heating capability when the value of the surplus electrical power is more than a specified value and to cause the heating means to boil-up the hot water in the hot water storing tank 11 by the standard heating capability when the value of the surplus electrical power is less than the specified value.SELECTED DRAWING: Figure 1

Description

The present invention relates to an electric water heater and a boiling method for boiling hot water in a hot water storage tank using electric power as an energy source.

In recent years, the use of electric water heaters that boil hot water in a hot water storage tank using electric power generated by power generation of a private power generator in addition to electric power supplied from an external commercial power generation facility has been advanced. Specific examples of such an electric water heater are described in Patent Documents 1 and 2.
Patent Document 1 directly adjusts the amount to be heated at night based on the predicted value of the next day of the electric power that is directly connected to the solar power generation facility and can be used for boiling hot water among the power generation amount of the solar power generation facility. In addition, an electric water heater (hot water storage type hot water supply system) that effectively uses electric power obtained by solar power generation is described.

Patent Document 2 discloses an electric water heater (electric water heater) connected to a solar power generation module via a controller of HEMS (Home Energy Management System). This electric water heater can reduce the cost of power used by adjusting the amount of power used by solar power generation and the amount of power used from commercial power generation facilities.

JP 2013-148287 A JP2013-245839A

By the way, in the electric water heater, a standard heating capacity for giving a predetermined amount of heat per unit time to the hot water in the hot water storage tank is set for each model, and in the conventional electric water heater, Boiled with standard heating capacity. Therefore, in the conventional electric water heater, the power consumption of the electric water heater is not increased or decreased according to the amount of power obtained by the power generation of the private power generator, and can be obtained by the power generation of the private power generator. When there is a surplus in the electric power, there is a problem that the surplus is not used in the boiling operation.
The present invention has been made in view of such circumstances, and it is an object of the present invention to provide an electric water heater and a boiling method that can boil hot water using surplus power generated by a private power generator. And

The electric water heater according to the first invention that meets the above-described object is a high-temperature heating tank and a standard heating capability that uses privately generated power obtained by power generation of a private power generator, or a high heating that generates a larger amount of heat than the standard heating capability. Heating means for boiling hot water in the hot water storage tank by capacity, and boiling hot water in the hot water storage tank by the standard heating capacity using external power supplied from a commercial power generation facility, and the private power generation The surplus power value is obtained from the outside, and when the surplus power value is equal to or greater than a predetermined value, the heating means boils the hot water in the hot water storage tank with the high heating capacity, and the surplus power And a control means for causing boiling of hot water in the hot water storage tank by the standard heating capacity when the value is less than the predetermined value.

In the electric water heater according to the first invention, the control means obtains a predicted value of surplus power of the private power generation in the non-midnight power time zone of the next day from the outside, and the heating means Obtaining a predicted value of the amount of heat that is heated in the hot water tank in the hot water tank by boiling with the high heating capacity in the late-night electric power hours, and in the hot water tank by boiling in the late-night electric power hours by the heating means It is preferable to calculate the amount of heat after boiling at night to be held in the hot water, and to cause the heating means to perform boiling at night.

In the electric water heater according to the first aspect, the control means intermittently obtains a new predicted value of the surplus power from the outside intermittently until the night boiling is started, and the new surplus power is obtained. It is preferable to calculate the calorific value after boiling at night each time the predicted value is obtained.

In the electric water heater according to the first aspect, during the night boiling, the control means intermittently acquires a new predicted value of the surplus power from the outside, and acquires the predicted value of the new surplus power. Each time, the amount of heat after boiling at night is calculated based on the predicted value of the new surplus power, and a value W obtained by subtracting the amount of heat held in the hot water in the hot water storage tank from the amount of heat after boiling at night When it is less than zero, it is preferable that the heating means stops the night-time boiling, and when the value W is greater than zero, the heating means continues the night-time boiling.

In the electric water heater according to the first invention, it is preferable that the control means obtains a predicted value of the surplus power from a HEMS controller.

In the electric water heater according to the first aspect of the present invention, the private power generator is preferably a solar power generator.

In the boiling method according to the second aspect of the present invention, the surplus power value is greater than or equal to a predetermined value in the heating step and the step S1 of obtaining the surplus power value of the self-generated power obtained by the power generation of the private power generator. In this case, the hot water in the hot water tank is boiled by a high heating capacity that generates an amount of heat larger than the standard heating capacity, and when the surplus power is less than the predetermined value, the hot water tank in the hot water tank is heated by the standard heating capacity. A step S2 of boiling water.

In the boiling method according to the second invention, a predicted value of surplus power of the private power generation in the non-midnight power time zone of the next day is obtained, and the heating means performs the high heating in the non-midnight power time zone of the next day. Step S3 for obtaining a predicted value of the amount of heating during the day given to the hot water in the hot water tank by boiling according to the capacity, and the nighttime in the midnight power time zone by the heating means based on the predicted value of the amount of heating during the day Step S4 for calculating the amount of heat after boiling at night to be held in the hot water in the hot water storage tank by boiling, and step S5 for causing the heating means to perform the night boiling based on the amount of heat after boiling at night Furthermore, it is preferable to have.

In the boiling method according to the second aspect of the invention, the step S3 is intermittently performed until the night-time boiling is started, and a new predicted value of the day-time boiling heat amount is obtained in the step S4. It is preferable to calculate a new amount of heat after boiling at night.

In the boiling method according to the second aspect of the present invention, step S6 of intermittently obtaining a new predicted value of surplus power during the night boiling, and obtaining the new predicted value of surplus power in step S6. Step S7 for calculating the amount of heat after boiling at night based on the predicted value of the new surplus power, and the amount of heat after boiling at night calculated in step S7 is stored in the hot water in the hot water storage tank. If the value W obtained by subtracting the amount of heat is less than or equal to zero, the heating means stops the night boiling, and if the value W is greater than zero, the heating means causes the heating means to continue heating at night S8, Furthermore, it is preferable to have.

According to the electric water heater according to the first invention and the boiling method according to the second invention, high heating that causes the heating means to generate a larger amount of heat than the standard heating capacity when the value of surplus power is a predetermined value or more. Since the hot water in the hot water storage tank is boiled according to the capacity, the surplus power generated by the private power generator can be used.

It is explanatory drawing of the electric water heater which concerns on one embodiment of this invention. (A), (B) is a graph which respectively shows the value with respect to the time at the time of employ | adopting the value at the time of employ | adopting the electric water heater of the amount of heat given to a hot water storage tank, and a comparative example.

Next, embodiments of the present invention will be described with reference to the accompanying drawings for understanding of the present invention.
As shown in FIG. 1, an electric water heater 10 according to an embodiment of the present invention includes a hot water storage tank 11, heating means 12 for boiling hot water in the hot water storage tank 11, and hot water in the heating means 12. And a control means 13 for performing boiling. Details will be described below.

As shown in FIG. 1, the electric water heater 10 is connected to a solar power generation device 14, which is an example of a private power generation device, via a distribution board 15, and is connected to a commercial power generation facility 16 with an external power transmission network 17 and a distribution board. 15 is connected. In FIG. 1, a thick line means a connection line for power supply, and a normal thickness line means a connection line for signal transmission. The solar power generation device 14 can supply electric power generated by absorbing sunlight (hereinafter also referred to as “self-generated power”) to the distribution board 15, and the distribution board 15 can supply the generated power to the electric water heater. 10 or an electric product (not shown) (for example, a refrigerator or a lighting fixture).

As shown in FIG. 1, the electric water heater 10 includes a hot water storage tank 11 and a control unit 13 housed in a housing 18, and a heating unit 12 provided outside the housing 18.
In the present embodiment, the heating means 12 is a heat pump unit that applies heat absorbed from the atmosphere to the hot water in the hot water storage tank 11 using a heat pump cycle, and the electric power supplied from the private power generation or commercial power generation equipment 16 ( The hot water in the hot water storage tank 11 is boiled by operating using “external power”.

In the present embodiment, boiling of hot water in the hot water storage tank 11 of the heating means 12 is set to boiling by standard heating capacity and boiling by high heating capacity that generates an amount of heat larger than the standard heating capacity.
Boiling by the standard heating capacity means boiling in which the heating means 12 maintains a state in which a predetermined amount of heat S is given per unit time to the hot water in the hot water storage tank 11, and the predetermined amount of heat S is an electric water heater. It is a specific value predetermined for each product.

Boiling with a high heating capacity is a heating that the heating means 12 gives to the hot water in the hot water storage tank 11 per unit time is larger than a predetermined heat quantity S. In this embodiment, the heat quantity H is private. It changes according to the magnitude of the generated power.
The heating means 12 can boil hot water in the hot water storage tank 11 using self-generated power with standard heating capacity or high temperature heating capacity, and boil hot water in the hot water storage tank 11 using external power. This can be done with standard heating capacity.

The control means 13 is a base on which electronic components such as an information processing chip and a storage device are mounted, and sends a command signal to the heating means 12 to operate the heating means 12 in accordance with a software program stored in the storage device. A temperature sensor (not shown) that measures the temperature of hot water in the hot water storage tank 11 is connected to the control means 13. The control means 13 can acquire the temperature information of the hot water in the hot water storage tank 11 from the temperature sensor, and can calculate the amount of heat of the entire hot water in the hot water storage tank 11.

Connected to the distribution board 15 is a HEMS controller 22 connected to an external server 21 via a router 19 and an Internet network 20. The HEMS controller 22 includes a communication device and a microcomputer, and includes a self-generated power amount input from the solar power generation device 14 to the distribution board 15 and an external power input from the commercial power generation facility 16 to the distribution board 15. It is possible to detect the amount and the amount of power output from the distribution board 15 to the electric water heater 10 and other electrical products (hereinafter also referred to as “power consumption”).

The HEMS controller 22 detects the amount of self-generated power, the amount of external power, and the amount of power used continuously or intermittently, and calculates the value of the surplus power of the power generated by subtracting the amount of power used from the amount of power generated by the home. To do. Hereinafter, “surplus power of private power generation” is also simply referred to as “surplus power”.
The control means 13 can obtain the value of surplus power continuously or intermittently from the HEMS controller 22 (that is, from the outside). When the obtained surplus power value is equal to or greater than the predetermined value P, the control means 13 The hot water in the hot water storage tank 11 is boiled with high heating capacity, and when the surplus power is less than the predetermined value P, the heating means 12 is made to boil hot water in the hot water storage tank 11 with the standard heating capacity.

As shown in FIG. 2 (A), the time when the surplus power value is equal to or greater than the predetermined value P as shown in FIG. 2 (A) by switching between boiling with the high heating capacity and boiling with the standard heating capacity in accordance with the surplus power value. In T1 to T2, the amount of heat given to the hot water in the hot water storage tank 11 per unit time exceeds the predetermined amount of heat S due to the influence of the boiling operation using surplus power. Therefore, in electric water heater 10 according to the present embodiment, compared with the result shown in FIG. 2 (B) according to the comparative example in which only the heating with the standard heating capacity is performed, at time T1 to T2, the hot water storage tank The total amount of heat given to the hot water in 11 increases.

In addition, the HEMS controller 22 can add time information at which detection is performed for each of the private power generation amount, the external power amount, and the used power amount to each detection value, and can transmit the detected time information to the external server 21 via the Internet network 20. .
Based on the information received from the HEMS controller 22, weather prediction information, etc., the external server 21 obtains the predicted power consumption at each time of the next day and the predicted private power generation energy at each time of the next day, and at each time of the following day. A predicted value of surplus power of the private power generation power (a value obtained by subtracting the predicted power consumption from the predicted private power generation amount) is calculated, and the calculated surplus power prediction value at each time on the next day is transmitted to the HEMS controller 22.
Hereinafter, “surplus power of private power generation” is also simply referred to as “surplus power”.

The control means 13 is connected to the HEMS controller 22 via the adapter 23 and the router 19, and can receive the predicted value of surplus power at each time of the next day from the HEMS controller 22. The control means 13 may be wired or wirelessly connected to the router 19.
By the way, the usage charge of external power is different in unit price in the midnight power time zone (for example, the time zone from 23:00 to 8:00) and the non-midnight power time zone (for example, the time zone from 8:00 to 23:00). The unit price in the time zone is lower than the unit price in the non-midnight power hours zone. Therefore, by reducing the amount of external power used in the non-midnight power hours, the usage fee for external power can be suppressed.

In this embodiment, the solar power generation device 14 is adopted as a private power generation device. In Japan, the solar power generation device 14 generates power during the daytime, that is, in the non-midnight power hours, so surplus power is generated. Occurrence occurs only during non-midnight power hours.
The control means 13 obtains a predicted value of surplus power at each time in the non-midnight power time zone of the next day from the HEMS controller 22 (that is, from the outside) until the start of the midnight power time zone. Based on the predicted value of surplus power at each time in the midnight power time zone, during the non-midnight power time zone of the next day, the heating means 12 gives the hot water in the hot water storage tank 11 to the hot water in the hot water tank 11 by boiling with high heating capacity. Find the predicted value of heat.

And the control means 13 is based on the past record of the amount of heat given to the hot water in the hot water storage tank 11 in the non-midnight power time zone and the predicted value of the day-time boiling heat amount before the midnight power time zone starts. The amount of heat after boiling at night that should be held (secured) in the hot water in the hot water storage tank 11 is calculated by boiling at night using external power during the midnight power hours by the heating means 12, and the calculated amount of heat after boiling at night is calculated as midnight power. The heating means 12 is caused to boil at night so that the heating means 12 supplies the hot water in the hot water storage tank 11 until the time zone ends.

In this way, by calculating the predicted amount of heating during the day based on the predicted value of surplus power the next day, calculating the amount of heat after boiling at night, and controlling the heating at night, the heating means controls the hot water in the hot water storage tank. The total amount of external electric energy used for boiling at night is reduced compared to calculating the estimated value of heating value during daytime heating and the amount of heat after boiling at night, assuming that the heating is performed only with the standard heating capacity. can do. In addition, in the non-midnight power time zone, boiling using surplus power can be performed, and as a result, the total external power throughout the day can be suppressed.

In the present embodiment, the control unit 13 intermittently acquires a new surplus power predicted value from the HEMS controller 22 until the night boiling by the heating unit 12 is started, and the new surplus power predicted value. The amount of heat after boiling at night is calculated each time, and the timing at which the heating means 12 starts boiling at night is determined based on the latest amount of heat after boiling at night. Since the predicted value of surplus power calculated by the HEMS controller 22 may change with the passage of time, for example, due to a change in the forecast of the next day's weather, the amount of heat after boiling at night based on the latest predicted surplus power value It is preferable from the viewpoint of promoting boiling using surplus power to calculate the value and perform boiling at night.

While the night boiling is being performed, the control unit 13 intermittently acquires a new surplus power predicted value from the HEMS controller 22, and every time a new surplus power predicted value is acquired, a new surplus power is obtained. If the value W obtained by subtracting the amount of heat currently held in the whole hot water in the hot water storage tank 11 from the amount of heat after boiling at night is calculated based on the predicted value of 12 is stopped at night, and when the value W is greater than zero, the heating means 12 is allowed to continue boiling at night.

Since the predicted value of surplus power calculated by the HEMS controller 22 may change with the passage of time, the midnight power time is determined by determining the timing for completing the night boiling based on the latest surplus power predicted value. It is possible to effectively suppress the amount of external power used for boiling performed during the non-midnight power hours after the band.
In addition, even after the night boiling is finished, the control means 13 intermittently acquires a new surplus power predicted value from the HEMS controller 22 in the midnight power time zone, and obtains a new surplus power predicted value. Each time it is acquired, the amount of heat after boiling at night is calculated based on a new predicted value of surplus power, and the calculated amount of heat after boiling at night is less than the amount of heat currently held in the entire hot water in the hot water storage tank 11. Resume boiling at night.

Next, a boiling method according to an embodiment of the present invention using the electric water heater 10 will be described. In the boiling method using the electric water heater 10, the hot water in the hot water storage tank 11 is obtained by high heating capacity when the surplus power value is greater than or equal to a predetermined value P in the heating means 12 and the step S1 for obtaining the surplus power value. And boiling the hot water in the hot water storage tank 11 with the standard heating capacity when the surplus power value is less than the predetermined value P.

Further, in the present embodiment, the boiling method using the electric water heater 10 further obtains a predicted value of surplus power of the next day, and boils it up during the day of the next day based on the predicted value of the surplus power. Step S3 for obtaining a predicted value of heat, Step S4 for calculating the amount of heat after boiling at night based on the predicted value of daytime boiling heat amount, and nighttime based on the amount of heat after boiling at night in the heating means 12 Step S5 for causing boiling. Moreover, the process S3 is intermittently performed until the boiling at night is started, and the predicted value of the heating power during the next day is calculated based on the newly acquired predicted surplus power of the next day. Every time the predicted value of the amount of heat during daytime boiling is obtained, a new amount of heat after boiling at night is calculated in step S4.

And in this Embodiment, while the night boiling is performed, process S6 which acquires the predicted value of the surplus power of the new next day intermittently, and the predicted value of the surplus power of the next day new in process S6 Is obtained in the hot water in the hot water storage tank 11 from the step S7 for calculating the amount of heat after boiling at night based on the predicted value of surplus power on the next day, and the amount of heat after boiling at night calculated in step S7. If the value W obtained by subtracting the amount of heat is less than or equal to zero, the heating means 12 is further stopped at night, and if the value W is greater than zero, the heating means 12 is further continued to be heated at night. doing.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and all changes in conditions and the like that do not depart from the gist are within the scope of the present invention.
For example, the private power generator is not limited to a solar power generator, and may be a wind power generator or a geothermal power generator.
Further, the heating means is not limited to the heat pump unit as long as it operates by supplying electric power and boils hot water in the hot water storage tank.
The amount of heat given per unit time to the hot water in the hot water storage tank by the heating means by boiling with high heating capacity may be a fixed value.

DESCRIPTION OF SYMBOLS 10: Electric water heater, 11: Hot water storage tank, 12: Heating means, 13: Control means, 14: Solar power generation device, 15: Distribution board, 16: Commercial power generation equipment, 17: External power transmission network, 18: Housing , 19: router, 20: Internet network, 21: external server, 22: HEMS controller, 23: adapter

Claims (10)

A hot water storage tank,
Boiling of hot water in the hot water storage tank with a standard heating capacity using the self-generated power obtained by the power generation of the private power generator or a high heating capacity that generates a larger amount of heat than the standard heating capacity, and supplied from a commercial power generation facility Heating means for boiling hot water in the hot water storage tank with the standard heating capacity using external electric power,
Obtaining the value of the surplus power of the private power generation from outside, when the value of the surplus power is greater than or equal to a predetermined value, the heating means causes boiling of hot water in the hot water storage tank by the high heating capacity, An electric water heater comprising: control means for boiling water in the hot water storage tank by the standard heating capacity when the value of the surplus power is less than the predetermined value. 2. The electric water heater according to claim 1, wherein the control means obtains a predicted value of surplus power of the private power generation in the non-midnight power time zone of the next day from the outside, and the heating means performs the non-midnight on the next day. In the electric power time zone, a predicted value of day-time boiling heat amount given to the hot water in the hot water tank by boiling with the high heating capacity is obtained, and in the hot water tank by night heating in the late-night electric power time zone by the heating means. An electric water heater characterized by calculating an amount of heat after boiling at night to be held in hot water and causing the heating means to perform boiling at night. 3. The electric water heater according to claim 2, wherein the control means intermittently obtains a new predicted value of the surplus power from the outside intermittently until the night boiling is started, and the new surplus power is calculated. An electric water heater characterized by calculating the amount of heat after boiling at night each time a predicted value is obtained. The electric water heater according to claim 2 or 3, wherein the control means intermittently obtains a new predicted value of the surplus power from the outside intermittently during the night boiling, and obtains the predicted value of the new surplus power. Every time it is acquired, the amount of heat after boiling at night is calculated based on the predicted value of the new surplus power, and the value W obtained by subtracting the amount of heat held in the hot water in the hot water storage tank from the amount of heat after boiling at night The electric water heater is characterized in that when the temperature is less than or equal to zero, the heating means stops the boiling at night, and when the value W is greater than zero, the heating means continues the boiling at night. 5. The electric water heater according to claim 1, wherein the control unit obtains a predicted value of the surplus power from a HEMS controller. The electric water heater according to any one of claims 1 to 5, wherein the private power generator is a solar power generator. Step S1 for obtaining a value of surplus power of private power generated by power generation by the private power generator;
When the value of the surplus power is greater than or equal to a predetermined value, the heating means is caused to boil hot water in the hot water storage tank with a high heating capacity that generates a heat quantity larger than a standard heating capacity, and the value of the surplus power is equal to the predetermined value. When the temperature is lower than the above, the step S2 of boiling water in the hot water storage tank with the standard heating capacity is performed. The boiling method according to claim 7, wherein a predicted value of surplus power of the private power generation in the non-midnight power time zone of the next day is obtained, and the heating means is configured to perform the high heating capacity in the non-midnight power time zone of the next day. A step S3 for obtaining a predicted value of the amount of heat for day-to-day boiling given to hot water in the hot water storage tank by boiling by
Step S4 of calculating the amount of heat after boiling at night to be held in the hot water in the hot water storage tank by boiling at night in the midnight power time zone based on the predicted value of the amount of heat during daytime boiling,
A boiling method, further comprising a step S5 of causing the heating means to perform the night boiling based on the amount of heat after the night boiling. 9. The boiling method according to claim 8, wherein the step S <b> 3 is intermittently performed until the night-time boiling is started, and a new predicted value of the day-time boiling heat amount is obtained in the step S <b> 4. A method of boiling, characterized in that the amount of heat after boiling at night is calculated. In the boiling method according to claim 8 or 9, step S6 of obtaining a new predicted value of the surplus power intermittently during the night boiling,
Step S7 for calculating the amount of heat after boiling at night based on the predicted value of the new surplus power every time the predicted value of the new surplus power is acquired in Step S6;
When a value W obtained by subtracting the amount of heat held in the hot water in the hot water storage tank from the amount of heat after boiling at night calculated in step S7 is less than or equal to zero, the heating means stops the night boiling, When the value W is greater than zero, the heating method further includes a step S8 of causing the heating means to continue the night boiling.

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