WO2022185386A1

WO2022185386A1 - Hot water storage-type hot water supplier

Info

Publication number: WO2022185386A1
Application number: PCT/JP2021/007749
Authority: WO
Inventors: 直紀柴崎; 史郎風間; 謙作畑中; ▲泰▼成松村; 洋真黒柳
Original assignee: 三菱電機株式会社
Priority date: 2021-03-01
Filing date: 2021-03-01
Publication date: 2022-09-09
Also published as: JPWO2022185386A1

Abstract

A hot water storage-type hot water supplier according to the present disclosure comprises: a heating means which is driven by electrical power, has a heat pump cycle for heating water, and has a changeable heating capability; a hot water storage tank; and a control unit which controls a boiling operation for accumulating, in the hot water storage tank, the hot water heated by the heating means. The control unit is configured to perform the boiling operation by adjusting the heating capability of the heating means so that the power consumption during the boiling operation is no greater than a power consumption command value set as the upper limit value of the power available for the boiling operation.

Description

Storage hot water heater

This disclosure relates to a storage hot water heater.

In a given power supply area where power is supplied from a power company, the amount of power consumed varies from time to time. If the amount of power consumed in a power supply area increases and exceeds the amount of power supplied to that power supply area, there is a risk of a large-scale power outage. A balance with quantity is desired.

In this regard, for example, in Japanese Patent Laid-Open No. 2016-125733, based on the amount of power supplied to a predetermined power supply area and the predicted power consumption of electrical equipment, among a plurality of heat pump water heaters, A hot water supply control system is described that determines the number of heat pump units in boiling operation. In this hot water supply control system, by limiting the number of heat pump units that perform boiling operation, the amount of power supplied and the amount of power consumed are balanced.

Japanese Patent Application Publication No. 2016-125733

With a heat pump water heater, even if the target heating capacity is the same, the COP (=heating capacity/power consumption: Coefficient of Performance) changes depending on factors such as the outside air temperature and the water temperature entering the heat pump. Therefore, the actual power consumption during boiling does not necessarily match the expected power consumption. When the actual power consumption exceeds the predicted power consumption, there is a risk that the power consumption will exceed the target power consumption in the control that determines the number of heat pump units in operation based on the predicted power consumption.

In order to solve the above-described problems, the present disclosure provides hot water storage that is improved so that power consumption can be easily adjusted according to the allowable value of peak power even when the COP of the hot water storage type hot water heater changes. The purpose is to provide a type water heater.

The hot water storage type water heater according to the present disclosure is driven by electric power and has a heat pump cycle for heating water, a heating means capable of changing the heating capacity, a hot water storage tank, and hot water heated by the heating means in the hot water storage tank. and a control unit for controlling the accumulated boiling operation. The control unit adjusts the heating capacity of the heating means so that the power consumption during the boiling operation is equal to or less than the power consumption instruction value set as the upper limit of the power that can be used in the boiling operation. is configured to run

By adjusting the heating capacity during boiling operation so that it is less than the power consumption instruction value, it is possible to easily adjust the power consumption so that it does not exceed the allowable peak power value.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a schematic diagram showing the configuration of a hot water storage type hot water heater and its peripheral equipment according to Embodiment 1 of the present disclosure; Fig. 4 is a flowchart for explaining the control operation of the boiling operation of the hot water storage type water heater according to the first embodiment of the present disclosure; FIG. 4 is a diagram for explaining control of adjustment of a power consumption instruction value performed between the storage-type hot water heater and the HEMS according to Embodiment 1 of the present disclosure; 4 is a flowchart showing operations when the minimum required power consumption of the hot water storage type hot water heater according to Embodiment 1 of the present disclosure is greater than the power consumption instruction value.

Embodiments will be described below with reference to the drawings. Elements that are common or correspond to each figure are denoted by the same reference numerals, and overlapping descriptions are simplified or omitted. In this embodiment, the calorific value of hot water is calculated, for example, as a difference from the calorific value of water having a temperature equal to that of water supplied from a water source. In addition, in the present embodiment, when describing the calorie of hot water, in principle, the calorie of hot water is described in units of the quantity of hot water [L] when converted into the calorie of hot water at a predetermined standard hot water supply temperature. The value of the standard hot water supply temperature is 40° C., for example. In the present disclosure, simply describing “water” or “hot water” may include liquid water of any temperature, from low-temperature water to high-temperature hot water.

Embodiment 1.
FIG. 1 is a schematic diagram showing the overall configuration of a system including a hot water storage type hot water heater and peripheral devices thereof according to Embodiment 1 of the present disclosure. As shown in FIG. 1, a hot water storage type hot water heater 35 is installed in each of

ordinary houses

1a and 1b. However, the installation location of the hot water storage type water heater 35 is not limited to a general house. The hot water storage type water heater 35 may be, for example, a domestic one or a commercial one used in a facility or the like.

As shown in FIG. 1, the hot water storage type water heater 35 is a hot water storage type heat pump water heater that includes a hot water storage tank unit 33 and a heat pump unit (hereinafter "HP" unit) 7 . The HP unit 7 and the hot water storage tank unit 33 are connected via

pipes

16 and 17 through which water flows, and electrical wiring (not shown).

The HP unit 7 is driven by electric power and functions as heating means for heating the low temperature water led from the hot water storage tank 8 provided in the hot water storage tank unit 33 . The HP unit has equipment such as a compressor, a water refrigerant heat exchanger, an expansion valve and an air heat exchanger. These devices are annularly connected by pipes or the like, and constitute a refrigerant circuit in which a refrigerant is circulated by a compressor. A refrigerant circuit corresponds to a heat pump cycle that heats water. The water-refrigerant heat exchanger heats water, which has flowed in through an inlet, with a refrigerant, and causes the heated water to flow out through an outlet. Air heat exchangers exchange heat between air and refrigerant.

The value of the heating capacity of the refrigerant circuit of the HP unit 7 can be changed. In the following description, the heating capacity of the refrigerant circuit of the HP unit 7 may be simply referred to as "heating capacity". The heating capacity corresponds to the amount of heat given to water by the HP unit 7 per hour. The unit of heating capacity is kW (kilowatt), for example.

The compressor of the HP unit 7 is driven by a drive device (not shown) equipped with, for example, an inverter-controlled DC brushless motor. In this case, it is possible to change the pressure and temperature of the refrigerant discharged from the compressor and change the value of the heating capacity by adjusting the rotation speed of the compressor with the driving device. However, the hot water storage type hot water heater 35 is not limited to one using such a drive device. The configuration may be such that the pressure and temperature of the refrigerant to be discharged, or the value of the heating capacity is changed.

The hot water storage tank unit 33 contains various parts and piping. The hot water storage tank 8 is for storing hot water. A plurality of hot water temperature sensors (not shown) are attached to the surface of the hot water storage tank 8 at different heights. By detecting the temperature distribution of the hot water in the hot water storage tank 8 with these hot water storage temperature sensors, the remaining hot water amount and heat storage amount in the hot water storage tank 8 can be grasped.

The control unit 36 and the remote controller 44 are connected by wire or wirelessly so that they can communicate bidirectionally. The control unit 36 and the remote control 44 may be able to communicate via a network. Remote control 44 is an example of a user interface. The remote controller 44 has a display section that displays information and an operation section that can be operated by the user. The remote controller 44 may have a touch screen that functions as both a display and an operation unit.

The operation unit of the remote controller 44 has a function as an input means for receiving operation inputs of commands relating to the operation and set values of the storage-type water heater 35 . A person such as a user can remotely control the hot water storage type water heater and perform various settings by operating the operation unit. The display unit has a function as an informing means for informing a person such as a user of information. The remote controller 44 in the present embodiment has a display unit as notification means, but as a modification, it may have other notification means such as a voice guidance device. The remote controller 44 may be installed, for example, on the wall of the kitchen, living room, bathroom, or the like. Alternatively, for example, a mobile information terminal such as a smartphone may be configured to have a user interface function such as the remote control 44 . A plurality of remote controllers 44 may be configured to communicate with the control unit 36 .

A controller 36 is built into the hot water storage tank unit 33 . The hot water storage type hot water heater 35 may have, for example, a controller connected to each of the hot water storage tank unit 33 and the HP unit 7 so as to be able to communicate bidirectionally. In this case, these controllers cooperate to control the operation of the storage hot water heater. The control unit 36 includes a microcomputer or the like having a memory and a processor.

The control unit 36 receives the outputs of various sensors provided in the hot water storage type hot water heater 35 and information on user's operation details for the remote control 44 . The controller 36 is also electrically connected to various valves, pumps, etc. provided in the hot water storage tank unit 33 and the HP unit 7 . The control unit 36 controls the operating state of the pumps contained in the HP unit 7 and the hot water storage tank unit 33 and the flow path direction or switching position of the valves based on input information from various sensors and the remote controller 44. Thus, the operations of the HP unit 7 and the hot water storage tank unit 33 are respectively controlled. For example, as will be described later, the control unit 36 executes the boiling operation and the like, and also controls the boiling temperature in the boiling operation and the heating capacity of the HP unit 7 .

The control unit 36 is communicably connected to an energy management system 50, which is an external device. The energy management system 50 is a system called HEMS (Home Energy Management System), which is connected to a plurality of electric devices used in each

house

1a, 1b to be managed, and controls and manages them. In the following description, the energy management system 50 shall be called "HEMS50." The electric equipment which HEMS50 manages is connected so that HEMS50 and communication are possible. These electric appliances may include electric appliances such as IH cooking heaters, washing machines, televisions, and refrigerators, air conditioners, lighting equipment, ventilation fans, power storage equipment, and the like, in addition to hot water heaters.

The HEMS 50 can receive information, for example, via the Internet, from the power supply side, which is the main body of the system power supply or power generation equipment. In each of the plurality of

houses

1a, 1b, the HEMS 50 receives an indication of allowable peak power, which is the maximum allowable power usage, from the power supplier. The HEMS 50 calculates the power consumption instruction value of the hot water storage type water heater 35 based on the allowable peak power. The power consumption instruction value is a target value within which the power consumption of the hot water storage type water heater 35 should be kept within that range. Upon receiving the power consumption instruction value from the HEMS 50, the control unit 36 operates by adjusting the heating capacity of the HP unit 7 so that the power consumption during the boiling operation is equal to or less than the power consumption instruction value.

The control unit 36 performs a boiling operation in which the necessary amount of hot water is boiled and stored in the hot water storage tank 8 during the midnight hours. The "late night time period" is a low electricity price time period in which the unit price of electricity is cheaper than other time periods of the day. Electricity charges can be reduced by securing the necessary amount of hot water storage during late-night hours when the unit price of electricity is low. In the following description, a time zone other than the midnight time zone is referred to as a "non-midnight time zone". In the non-midnight time zone, the electricity rate unit price is higher than in the late night time zone. For example, if the time slot from 1:00 am to 6:00 am corresponds to the midnight time slot, the time slot from 6:00 am to 1:00 am the next day corresponds to the non-midnight time slot. The start time and end time of the late-night time zone and the non-midnight time zone are not limited to this example, and may change according to the contract with the power supplier. In addition, in the present disclosure, "one day" is assumed to consist of a late-night time period and the previous non-midnight time period. The control unit 36 stores information on the start time and end time of the late-night time period and the non-midnight time period. The control unit 36 has a timer function and can determine whether the current time is in the midnight time zone or in the non-midnight time zone. Further, the control unit 36 may acquire information about the start time and end time of the late-night time period and the non-midnight time period from the remote control 44 or the HEMS 50 .

The control unit 36 always calculates the target heat storage amount, which is the amount of heat required to be stored in the hot water storage tank 8, as the required hot water storage amount. Specifically, for example, the control unit 36 calculates the amount of heat used for hot water supply based on the water supply temperature, the hot water supply temperature, and the hot water supply flow rate detected by various sensors installed in the hot water storage tank unit 33 . The control unit 36 stores data related to the hot water supply heat amount calculated during the past predetermined period (for example, the past two weeks), and learns the hot water supply heat amount by, for example, statistically processing the hot water supply heat amount used during the past predetermined period. do. Note that the control unit 36 may be configured to learn the amount of heat used for hot water supply at each hour of the day. The required hot water storage amount is calculated based on the learned amount of heat used for hot water supply.

FIG. 2 is a flowchart for explaining the control operation of the boiling operation. The operation of the boiling operation will be described with reference to FIG. The control operation in FIG. 2 is repeatedly executed at regular control intervals.

First, in step S10, the power consumption instruction value from the HEMS 50 is obtained. Next, in S11, an estimated heating capacity is calculated. The estimated heating capacity is obtained by obtaining the outside air temperature and the temperature of the water entering the HP unit 7, and the energy consumption efficiency estimated by any one of the obtained outside air temperature, the water entering temperature, and the target hot water storage temperature, or a combination thereof, and the consumption It is a heating capacity value that does not exceed the power consumption instruction value estimated from the power instruction value.

Next, the amount of remaining hot water is obtained in S12, and the boiling start time is calculated in S13. Here, first, the difference between the required amount of stored hot water and the amount of remaining hot water is calculated for the boiling time required for boiling with the estimated heating capacity. Then, the time before the target time for completing the boiling of the required amount of hot water is calculated as the boiling start time.

For example, if the required amount of hot water stored at 7:00 am, which is the target time, is 500 L at 40°C conversion, the remaining hot water amount is 50 L at 40°C conversion, and the estimated heating capacity is 4 kW, the boiling time is about 4 hours. , 3:00 a.m. is the start time of boiling.

At step S14, it is determined whether or not the boiling start time has come. If it is determined in step S14 that the boiling start time has not yet come, the current process ends. On the other hand, when it is recognized in step S14 that the boiling start time has come, the boiling operation is started with the calculated estimated heating capacity, and after the required amount of hot water is stored, the boiling is finished. is terminated.

Furthermore, in the hot water storage type water heater 35 of the present embodiment, the control unit 36 always calculates the minimum required power consumption, and transmits this to the HEMS, thereby performing control to adjust the power consumption with the HEMS 50. . FIG. 3 is a diagram for explaining control of adjustment of the power consumption instruction value performed between the control unit 36 and the HEMS 50. As shown in FIG. This control will be described below with reference to FIG.

As shown in FIG. 3, in step S21, the control unit 36 acquires the amount of heat used for hot water supply, and in step S22, calculates the minimum required heating capacity that does not cause running out of hot water at the present time based on the amount of heat used for hot water supply. The minimum required heating capacity is calculated, for example, from the start time of the late-night time period when the electricity rate is cheaper and the required hot water storage amount at the end time of the non-midnight time period, so that heating can be completed during the late-night time period. do. Also, at this time, the time when the required hot water storage amount needs to be secured is taken into consideration. As an example, if the late-night time zone is 5 hours from 1:00 am to 6:00 am, the required hot water amount at 7:00 am is 500 L at 40°C conversion, and the remaining hot water amount is 50 L at 40° C., the minimum required heating capacity is Approximately 3 kW. However, the minimum required heating capacity may be calculated without considering the non-midnight hours, for example, by using the time at which the required amount of hot water needs to be secured as the boiling completion time.

Next, in step S23, with respect to the calculated minimum required heating capacity, the minimum required power consumption is calculated from any one of the outside air temperature, the water inlet temperature to the HP unit 7, and the target hot water storage temperature, or a combination thereof. . The calculated minimum required power consumption is transmitted to HEMS50 in step S24.

At step S30, the HEMS 50 receives the required minimum power consumption. In step S<b>31 , the HEMS 50 recalculates the power consumption instruction value for each electrical device managed by the HEMS 50 based on the minimum required power consumption, and redetermines the power consumption instruction value for the storage-type water heater 35 . HEMS50 transmits the determined power consumption instruction value to the control part 36 of the storage-type water heater 35, and the other electric equipment which HEMS50 manages by following step S32.

The control unit 36 receives the power consumption instruction value recalculated in step S25. Thereafter, in step S26, the boiling start time is recalculated according to the procedure of FIG. 2 based on the power consumption instruction value. In this way, the risk of running out of hot water can be reduced by readjusting the power consumption instruction value based on the minimum required power consumption.

Next, the processing when the power consumption indication value is smaller than the minimum required power consumption will be explained. FIG. 4 is a flow chart showing the operation when the power consumption instruction value is smaller than the minimum required power consumption.

As shown in FIG. 4, in step S41, it is determined whether or not the power consumption instruction value is lower than the minimum required power consumption. The power consumption instruction value is the latest power consumption instruction value received last by the control unit 36 . If it is determined in step S41 that the power consumption instruction value is greater than or equal to the minimum required power consumption, the current process ends. That is, by the process of FIG. 2, boiling is performed with the estimated heating capacity at the boiling start time.

On the other hand, if it is determined in step S41 that the power consumption instruction value is lower than the minimum required power consumption, then in step S42 it is determined whether or not peak power suppression is prioritized. The user can preset with the remote control 44 whether to give priority to suppression of peak power or to give priority to reducing the risk of running out of hot water as processing when the power consumption instruction value is lower than the minimum required power consumption. Therefore, the determination processing in step S42 is performed according to the currently set instruction.

If it is determined in step S42 that peak power suppression is given priority, in step S50 the heating capacity of the HP unit 7 in the boiling operation is set to the estimated heating capacity, which is the heating capacity that does not exceed the power consumption instruction value. .

Next, in step S51, the user is notified of the risk of running out of hot water by displaying on the remote control 44 that the necessary amount of hot water may not be secured. After that, the processing of this time is terminated.

On the other hand, if it is determined in step S42 that suppression of peak power is not prioritized, that is, if priority is given to reducing the risk of running out of hot water, the process proceeds to step S60. At step S60, the heating capacity of the HP unit 7 in the boiling operation is set to the minimum required heating capacity.

Next, in step S61, the remote controller 44 notifies the user that it may not be possible to suppress peak power consumption. Next, in step S62, the excess heating capacity information is transmitted to the HEMS 50. FIG. After that, the current processing of the control unit 36 ends. The HEMS 50 that has received the excess information adjusts the peak power to the extent possible in the entire electrical equipment.

As described above, according to the present embodiment, the power consumption can be easily adjusted with respect to the allowable peak power by adjusting the heating capacity so as to be equal to or less than the power consumption instruction value and performing the boiling operation. be able to. Further, by transmitting the minimum required power consumption to the HEMS 50 and adjusting the power consumption with the HEMS 50, it is possible to ensure a high degree of freedom in adjusting the power consumption with respect to the allowable peak power.

In this embodiment, the case where the HEMS 50 has the function of instructing the power consumption instruction value has been described, but the control unit 36 may be configured to have the function of acquiring the power consumption instruction value. For example, in the case of a power contract in which the basic rate changes depending on peak power, the configuration may be such that the power consumption instruction value can be set from the remote control 44 without using the HEMS 50 . In this case, the control unit 36 receives the power consumption instruction value from the remote controller 44, and adjusts the heating capacity so that the power consumption during the boiling operation is equal to or less than the power consumption instruction value, as described with reference to FIG. adjust and drive. Thereby, peak power can be similarly suppressed.

1a, 1b housing, 7 HP unit, 8 hot water tank, 16 piping, 17 piping, 33 hot water tank unit, 35 hot water storage type water heater, 36 control unit, 44 remote control, 50 energy management system (HEMS)

Claims

a heating means that is driven by electric power, has a heat pump cycle that heats water, and is capable of changing the heating capacity;
a water storage tank; and
a control unit for controlling a boiling operation for accumulating hot water heated by the heating means in the hot water storage tank;
with
The control unit adjusts the heating capacity of the heating means so that the power consumption during the boiling operation is equal to or less than the power consumption instruction value set as the upper limit of the power that can be used in the boiling operation. configured to perform the boiling operation,
A hot water storage type water heater characterized by:
The control unit
Estimating the heating capacity of the heating means based on at least one of the target heat storage amount to be secured in the hot water storage tank, the power consumption instruction value, the outside air temperature, and the temperature of water entering the heating means. Calculate the value of
starting the boiling operation so that the target heat storage amount can be secured at a preset target time based on the target heat storage amount and the estimated value of the heating capacity;
The hot water storage type water heater according to claim 1, characterized in that it is configured as follows.
The control unit is configured to calculate a required power consumption, which is the power consumed by the heating means in order to store the target heat amount to be secured in the hot water storage tank in the hot water storage tank by the completion time of boiling. 3. The hot water storage type water heater according to claim 1 or 2, characterized in that:
configured to communicate with an energy management device that controls and monitors the power consumption of the storage-type water heater and other electric devices installed in the management area and transmits the power consumption instruction value to the control unit;
The control unit is configured to transmit the required power consumption to the energy management device when the power consumption instruction value is smaller than the required power consumption.
The hot water storage type water heater according to claim 3, characterized in that:
The hot water storage type water heater according to claim 3 or 4, characterized in that the boiling completion time is a time before the time when it is necessary to secure the target heat storage amount.
The boiling completion time is set to a time before the time when it is necessary to secure the target heat storage amount and within a range of a low electricity price time period, which is a time period in which the electricity rate is cheaper than other time periods. The hot water storage type water heater according to claim 3 or 4.
When the power consumption instruction value is smaller than the required power consumption, the control unit executes the boiling operation within a range in which the power consumption in the boiling operation is equal to or less than the power consumption instruction value. Item 7. The hot water storage type hot water heater according to any one of items 3 to 6.
further comprising a notification means capable of notifying the user of information regarding the operation of the hot water storage type hot water heater,
When the power consumption instruction value is smaller than the required power consumption, the control unit performs the water heating operation within a range in which the power consumption in the water heating operation is equal to or less than the power consumption instruction value. 8. The hot water storage type water heater according to claim 7, wherein the user is notified that the target heat storage amount may not be ensured.
7. The control unit according to any one of claims 3 to 6, wherein, when the power consumption instruction value is smaller than the required power consumption, the boiling operation is performed by exceeding the power consumption instruction value. A storage-type water heater described.
further comprising a notification means capable of notifying the user of information regarding the operation of the hot water storage type hot water heater,
When the power consumption instruction value is smaller than the required power consumption and the boiling operation is performed exceeding the power consumption instruction value, the control unit cannot suppress the peak power consumption by the notification means. 10. The hot water storage type water heater according to claim 9, wherein the user is notified of the possibility.
further comprising an input means for receiving an operation input of a command from a user regarding the operation and set values of the hot water storage type hot water heater,
When the power consumption instruction value is smaller than the required power consumption, it is possible to select whether the heating capacity is set by the power consumption instruction value or the required power consumption by an operation input from the input means. It is configured,
The hot water storage type hot water heater according to any one of claims 3 to 10, characterized in that: