JP6897331B2 - Hot water storage type water heater - Google Patents

Description

The present invention relates to a hot water storage type water heater.

Conventionally, a hot water storage type water heater is widely used in which hot water heated by a heating means such as a heat pump is stored in a hot water storage tank, and hot water taken out from the hot water storage tank is used to supply hot water to a hot water supply destination such as a bathtub.

For example, Patent Document 1 discloses a hot water supply system capable of performing a boiling operation using electric power from a photovoltaic power generation facility. In this system, the next day's value of surplus power, which is the power that can be used for boiling operation among the power generated by the photovoltaic power generation facility during the daytime, is predicted. Then, when the predicted surplus power of the next day is large, the amount of boiling in the nighttime boiling operation using the power from the grid power equipment is smaller than that in the case where the surplus power is small.

Japanese Unexamined Patent Publication No. 2013-148287

Depending on the contents of the power contract, it is expected that the user will be disadvantaged by reducing the boiling operation at night. In the technique of Patent Document 1 described above, when a large amount of hot water is boiled by a boiling operation using electric power obtained by a photovoltaic power generation facility, the boiling amount of the boiling operation at night is reduced. Therefore, the above-mentioned technique of Patent Document 1 does not always result in a boiling operation that meets the user's request.

The present invention has been made to solve the above-mentioned problems, and is capable of effectively using the electric power obtained from the photovoltaic power generation facility while meeting the user's request according to the contents of the electric power contract. The purpose is to provide a type water heater.

The hot water storage type water heater according to the present invention is connected to each of the photovoltaic power generation equipment and the grid power equipment, and is a heating means for heating water with the power supplied from the photovoltaic power generation equipment or the grid power equipment to generate hot water. In a hot water storage type water supply machine equipped with a hot water storage tank that stores hot water generated by the heating means, as a boiling operation that generates hot water by the heating means and stores it in the hot water storage tank, a photovoltaic power generation facility during the daytime. It is equipped with a control device that performs daytime boiling operation using the power supplied from the system and nighttime boiling operation using the power supplied from the grid power equipment during the night time, and the control device is currently set. Setting means for setting the power contract mode to the night time priority mode corresponding to the power contract when the power contract is a power contract in which the unit price of power in the night time is cheaper than the unit price of power in the daytime. When the night time zone priority mode that prioritizes the night boiling operation over the daytime boiling operation is set by the setting means, the night boiling is compared with the case where the night time zone priority mode is not set. It is configured to execute a normal mode in which the boiling amount of the raising operation is increased.

According to the hot water storage type water heater of the present invention, a night time zone priority mode is set in which priority is given to nighttime boiling operation using electric power from the system power generation equipment rather than daytime boiling operation using electric power from the photovoltaic power generation equipment. If this is the case, the amount of boiling by the night boiling operation is larger than that in the case where the night time zone priority mode is not set. As a result, it becomes possible to effectively use the electric power obtained from the photovoltaic power generation facility while meeting the user's request according to the contents of the electric power contract.

It is a block diagram which shows the hot water storage type water heater of Embodiment 1. FIG. It is a flowchart which shows the routine which is executed in the hot water storage type water heater of Embodiment 1.

Hereinafter, embodiments will be described with reference to the drawings. The elements common to each figure are designated by the same reference numerals, and duplicate description will be omitted.

Embodiment 1.
FIG. 1 is a configuration diagram showing a hot water storage type water heater according to the first embodiment. As shown in FIG. 1, the hot water storage type water heater 35 of the first embodiment includes a tank unit 33 and a heat pump unit 7 configured to utilize a heat pump cycle. The heat pump unit 7 and the tank unit 33 are connected via a heat pump forward pipe 14, a heat pump return pipe 15, and electrical wiring (not shown). Further, the tank unit 33 has a built-in control device 36 that controls the operation operation of the hot water storage type water heater 35. The control device 36 is composed of, for example, a microprocessor or the like. The control device 36 includes a storage unit as a storage means including a ROM, a RAM, a non-volatile memory, and the like, an arithmetic processing unit (CPU) that executes arithmetic processing based on a program stored in the storage unit, and an arithmetic processing unit. On the other hand, it is equipped with an input / output port for inputting / outputting external signals. Various valves, pumps, and sensors included in the tank unit 33 and the heat pump unit 7 are connected to the control device 36 via electrical wiring. The control device 36 is connected to the remote controller 44 and the communication adapter 46 so as to be able to communicate with each other.

Although not shown, the remote controller 44 is equipped with a display unit that displays information such as the status of the hot water storage type water heater 35, an operation unit such as a switch operated by the user, a speaker, a microphone, and the like. The communication adapter 46 has a communication function with an external device. The communication adapter 46 can receive weather forecast information via an external communication line (not shown). Further, the communication adapter 46 is connected to the energy management device 48 so as to be able to communicate with each other wirelessly or by wire. The energy management device 48 is connected to a photovoltaic power generation facility 47 composed of a photovoltaic power generation panel. The energy management device 48 constantly acquires and stores the amount of solar power generated by the photovoltaic power generation facility 47 and the amount of power used in the home. The communication adapter 46 can receive such information stored in the energy management device 48. The information received by the communication adapter 46 is transmitted to the control device 36.

Next, each component of the hot water storage type water heater 35 will be described. The heat pump unit 7 functions as a heating means for heating the water led from the tank unit 33. The heat pump unit 7 constitutes a heat pump cycle by connecting a compressor 1, a water refrigerant heat exchanger 3, an expansion valve 4, and an air heat exchanger 6 in an annular shape by a refrigerant circulation pipe 5. The water-refrigerant heat exchanger 3 exchanges heat between the refrigerant and the water guided from the tank unit 33.

The tank unit 33 contains the following various parts, pipes, and the like. The hot water storage tank 8 forms a temperature stratification in which the upper side is high temperature and the lower side is low temperature to store hot water. A third water supply pipe 9c of a water supply pipe 9 for supplying low-temperature water, which is city water, is connected to a water inlet 8a provided at the bottom of the hot water storage tank 8. The water supply line 9 will be described later. A hot water introduction outlet 8d is provided above the hot water storage tank 8. A hot water supply pipe 21 for supplying the hot water stored in the hot water storage tank 8 to the outside of the water heater is connected to the hot water introduction outlet 8d. The high-temperature water heated by the heat pump unit 7 flows into the hot water storage tank 8 from the upper part of the tank, and the low-temperature water flows into the lower part of the tank through the third water supply pipe 9c. Hot water is stored so that there is a temperature difference at the bottom. In order to detect the temperature distribution of hot water in the hot water storage tank 8, a plurality of temperature sensors are installed on the surface of the hot water storage tank 8 at different heights. In the first embodiment, the temperature thermistors 42 and 43 are arranged at different heights in the upper region and the lower region of the hot water storage tank 8. The control device 36 grasps the amount of remaining hot water in the hot water storage tank 8, that is, the amount of boiling heat stored in the hot water storage tank 8 based on the temperature distribution acquired by these temperature thermistors attached to the hot water storage tank 8.

Further, a circulation pump 12 and a bath heat exchanger 20 are built in the tank unit 33. The circulation pump 12 is a pump for circulating hot water through various pipes described later. The bath heat exchanger 20 is a heat exchanger for heating the fluid to be heated on the secondary side by using the high temperature water supplied from the hot water storage tank 8 or the heat pump unit 7. In the first embodiment, as the configuration of the secondary side of the bath heat exchanger 20, a bath going pipe 27 and a bath returning pipe 28 for circulating hot water in the bathtub 30 will be described as an example. The bath heat exchanger 20 is connected to the bathtub 30 via the bath going pipe 27 and the bath returning pipe 28, and a circulation path is formed by these. In the middle of the bath return pipe 28, a bath circulation pump 29 for circulating bathtub water and a bath return temperature thermista 38 for detecting the temperature of the bathtub water discharged from the bathtub 30 are installed. A bath temperature thermistor 37 for detecting the temperature of the bathtub water after heat exchange from the bath heat exchanger 20 is installed in the middle of the bath pipe 27.

Next, the valves and pipes included in the tank unit 33 will be described. The tank unit 33 has a three-way valve 11 and a four-way valve 18. The three-way valve 11 is a flow path switching means having two inlets for hot water to flow in, a port and b port, and one outlet for hot water to flow out, c port, and is either a port or b port. It is configured so that the hot water route can be switched so that hot water flows in from the water. The four-way valve 18 has two inlets, b-port and c-port, from which hot water flows in, and a-port and d-port, which are two outlets from which hot water flows out. The four-way valve 18 is configured so that the flow path form can be switched between the four paths, that is, the ab path, the ac path, the bd path, and the cd path.

Further, the tank unit 33 includes a water outlet pipe 10, a hot water supply pipe 13, a first bypass pipe 16, a second bypass pipe 17, a hot water introduction pipe 20a and a hot water outlet pipe 20b constituting a heat source side circuit. have.

The water outlet pipe 10 is a flow path that connects the water outlet 8b of the hot water storage tank 8 and the a port of the three-way valve 11. The hot water supply pipe 13 is a flow path connecting the d port of the four-way valve 18 and the hot water introduction outlet 8d at the upper part of the hot water storage tank 8. The heat pump forward pipe 14 described above is a flow path connecting the c port of the three-way valve 11 and the inlet side of the heat pump unit 7, and the heat pump return pipe 15 is a flow path connecting the outlet side of the heat pump unit 7 and the c port of the four-way valve 18. It is a flow path for connecting the above. A circulation pump 12 is arranged in the middle of the heat pump going pipe 14. The first bypass pipe 16 is a flow path connecting the a port of the four-way valve 18 and the hot water introduction port 8c provided between the central portion and the lower portion of the hot water storage tank 8 in the height direction. The second bypass pipe 17 is a flow path that branches from between the circulation pump 12 provided in the middle of the heat pump going pipe 14 and the inlet side of the heat pump unit 7 and is connected to the b port of the four-way valve 18. The hot water introduction pipe 20a is a flow path that branches from the middle of the hot water supply pipe 13 and is connected to the primary side inlet of the bath heat exchanger 20. The hot water outlet pipe 20b is a flow path connecting the primary side outlet of the bath heat exchanger 20 and the b port of the three-way valve 11.

The tank unit 33 further includes a first water supply pipe 9a, a second water supply pipe 9b, a hot water supply mixing valve 22, a bath mixing valve 23, a first hot water supply pipe 24, and a second hot water supply pipe 25. One end of the first water supply pipe 9a is connected to a water source such as water supply, and the second water supply pipe 9b and the third water supply pipe 9c are connected to the other end of the first water supply pipe 9a via a pressure reducing valve 31. The water supply pipe line 9 is composed of the first water supply pipe 9a, the second water supply pipe 9b, and the third water supply pipe 9c. The second water supply pipe 9b branches from the middle and is connected to the hot water supply mixing valve 22 and the bath mixing valve 23, respectively. Further, the hot water supply pipe 21 branches from the middle and is connected to the hot water supply mixing valve 22 and the bath mixing valve 23, respectively. In the middle of the second hot water supply pipe 25, a bath solenoid valve 26 for opening and closing the second hot water supply pipe 25 and a bath flow rate sensor 45 for detecting the flow rate of hot water passing through the second hot water supply pipe 25 are provided.

The hot water supply mixing valve 22 and the bath mixing valve 23 adjust the flow rate ratio of the high temperature water supplied from the hot water supply pipe 21 and the low temperature water supplied from the second water supply pipe 9b. As a result, hot water having a set temperature set by the user is generated and flows into the first hot water supply pipe 24 and the second hot water supply pipe 25, respectively. The hot water whose temperature has been adjusted by the hot water supply mixing valve 22 is supplied from the first hot water supply pipe 24 to a faucet such as a shower or a faucet (not shown). On the other hand, the hot water whose temperature has been adjusted by the bath mixing valve 23 is supplied from the second hot water supply pipe 25 to the bathtub 30 via the bath solenoid valve 26, the bath going pipe 27, and the bath returning pipe 28.

The control device 36 of the hot water storage type water heater 35 shown in FIG. 1 has a function of executing a boiling operation. The boiling operation is an operation in which the hot water boiled by using the heat pump unit 7 is stored in the hot water storage tank 8. During this boiling operation, the heat pump unit 7 and the circulation pump 12 are operated. Further, the three-way valve 11 is controlled so that the a port communicates with the c port and the b port is closed. Further, the four-way valve 18 is controlled so that the c port communicates with the d port and the a port and the b port are closed. In the boiling operation, the water led out from the water outlet 8b of the hot water storage tank 8 by the circulation pump 12 passes through the water outlet pipe 10, the three-way valve 11, and the heat pump forward pipe 14, and heats the water refrigerant in the heat pump unit 7. It is sent to the exchanger 3. Then, the high-temperature water heated by the water-refrigerant heat exchanger 3 in the heat pump unit 7 passes through the heat pump return pipe 15, the four-way valve 18, and the hot water supply pipe 13, and flows into the hot water storage tank 8 from the hot water introduction outlet 8d. By executing such a boiling operation, high-temperature water is stored from the upper layer inside the hot water storage tank 8, and the high-temperature water layer gradually becomes thicker.

Further, the hot water storage type water heater 35 shown in FIG. 1 is a system (not shown) as the above-mentioned photovoltaic power generation facility 47 as a supply source of electric power used for boiling operation, that is, electric power for operating the heat pump unit 7 and the circulation pump 12. It is connected to the power equipment. The control device 36 has a function of switching whether the electric power used for the boiling operation is supplied from the photovoltaic power generation facility 47 or the grid power facility.

Next, the characteristic operation of the hot water storage type water heater 35 of the first embodiment will be described. Some power grid equipment charge systems have different unit prices set for each time zone. Under the power charge system in which there are night time zones where the power charge is low and daytime hours when the power charge is higher than the night time zone, it is preferable to perform the boiling operation within the night time zone. Hereinafter, the boiling operation using the electric power from the grid power equipment during the night time zone will be referred to as "night boiling operation". In the night-time boiling operation, the boiling operation is performed until the required amount of hot water required for the next day is stored.

On the other hand, in the hot water storage type hot water supply machine 35 provided with the photovoltaic power generation facility 47 as the power supply source, the power generated by the photovoltaic power generation facility 47 can be expected to be used during the daytime. Therefore, if there is surplus power that can be used for boiling operation among the power generated by the photovoltaic power generation facility 47 during the daytime, it is boiled without using the power from the grid power facility during the daytime. It is possible to carry out raising operation. Hereinafter, the boiling operation using the surplus electric power from the photovoltaic power generation facility 47 during the daytime time zone is referred to as “daytime boiling operation”. In the daytime boiling operation, the boiling operation is performed until the hot water storage tank 8 is full or the amount of hot water reaches a predetermined amount within the range of utilization of the surplus electric power on the day.

Here, when the amount of hot water boiled by the daytime boiling operation becomes large, the amount of boiling water required in the nighttime boiling operation decreases. Depending on the power contract concluded by the user, it is expected that there will be a disadvantage due to the reduction of night boiling operation.

Therefore, the control device 36 of the hot water storage type water heater 35 of the first embodiment is a setting means for setting whether to prioritize the night boiling operation or the daytime boiling operation according to the power contract currently set. It has. More specifically, the control device 36 of the hot water storage type water heater 35 includes means for setting a power contract mode corresponding to the current power contract. Such means can be realized, for example, by providing a configuration for the user or the builder to operate the remote controller 44 to select or input the corresponding power contract mode. Further, it is also possible to adopt a configuration in which the control device 36 acquires the corresponding power contract mode from the communication adapter 46 via the external communication line.

The control device 36 stores, as an embodiment of the boiling operation, a normal mode in which the night boiling operation is prioritized and a surplus power utilization mode in which the daytime boiling operation is prioritized. The control device 36 includes a prediction means for predicting the required amount of hot water required on the next day based on the history of the amount of hot water used in the past. In normal mode, this predictor predicts the required amount of hot water needed the next day. For example, the control device 36 predicts the maximum value of the amount of hot water used in the past two weeks as the required amount of hot water. Then, in the normal mode, the required amount of hot water is boiled by the night boiling operation regardless of the presence or absence of surplus electric power on the next day.

On the other hand, in the surplus power utilization mode, the control device 36 reduces the amount of boiling due to the night boiling operation as compared with the case of the normal mode. For example, the control device 36 sets a fixed amount, for example, 100 L less than the required amount of hot water in the normal mode, as the boiling amount by the night boiling operation. That is, in the surplus power utilization mode, the amount of boiling due to the night boiling operation is reduced as compared with the normal mode. When the amount of boiling by the night boiling operation decreases, the amount that can be boiled by the daytime boiling operation increases by that amount. As a result, in the surplus power utilization mode, the daytime boiling operation is prioritized.

The control device 36 determines the mode for performing the boiling operation according to the set power contract mode and the like. Hereinafter, a specific operation in which the control device 36 determines the mode in the boiling operation will be described with reference to the flowchart.

FIG. 2 is a flowchart showing a routine executed when the control device 36 determines a mode in the boiling operation in the hot water storage type water heater of the first embodiment. In step S1 of the routine shown in FIG. 2, it is first determined whether or not the surplus power may be utilized. The remote controller 44 is provided with a selection means for switching between permission and prohibition of utilization of surplus electric power. Here, for example, it is determined whether or not the user has selected from the selection means of the remote controller 44 to permit the utilization of the surplus power. As a result, if the determination is confirmed, the process proceeds to the next step S2, and if the determination is not established, the process proceeds to the next step S5.

In the next step S2, it is determined whether or not the currently set power contract mode is the night time zone priority mode corresponding to the night time zone priority contract. The nighttime time zone priority contract here refers to an electric power contract in which nighttime boiling operation should be prioritized over daytime boiling operation. Such nighttime priority contracts include, for example, a power contract in which the unit price of electricity in the night time is cheaper than that in the daytime, a power contract to which a power supply control type night heat storage type equipment discount is applied, and the like. Applies to. As a result, if the determination is confirmed, the process proceeds to step S5, and if the determination is not established, the process proceeds to step S3.

In step S3, it is determined whether or not there is a surplus power time zone on the next day. The surplus electric power time zone here refers to a time zone in which the electric power used for the daytime boiling operation can be secured among the electric power supplied from the photovoltaic power generation facility 47. Here, for example, the predicted value of the generated power in the daytime time zone of the next day is calculated based on the weather prediction information. Further, based on the past results of power consumption and generated power transmitted from the energy management device 48, a predicted value of power consumption used by other devices during the daytime of the next day is calculated. The presence or absence of the surplus power time zone is determined by whether or not there is a time zone in which the predicted value of the generated power exceeds the predicted value of the power consumption in the daytime time zone. As a result, if the determination is confirmed, the process proceeds to step S4, and if the determination is not established, the process proceeds to step S5.

In step S4, the surplus power utilization mode for utilizing the surplus power is set. On the other hand, in step S5, the normal mode is set.

As described above, according to the hot water storage type water heater 35 of the first embodiment, it is determined whether or not the night boiling operation should be prioritized according to the electric power contract mode and the like. As a result, it becomes possible to effectively utilize the electric power obtained by the photovoltaic power generation facility according to the electric power contract.

The hot water storage type water heater 35 of the first embodiment may adopt, for example, a modified mode as follows.

The control device 36 is configured so that when the power contract mode is set to the night time zone priority mode, the amount of boiling due to the daytime boiling operation is reduced as compared with the case where the night time zone priority mode is not set. You may be. In such a configuration, for example, the amount of boiling by the daytime boiling operation when the normal mode is set is smaller than the amount of boiling by the daytime boiling operation when the surplus power utilization mode is set. It should be set to. This makes it possible to meet the demands of users who desire to prioritize night-time boiling operation.

The control device 36 may be configured to prohibit the boiling amount due to the daytime boiling operation when the power contract mode is set to the night time zone priority mode. As such a configuration, for example, the daytime boiling operation when the normal mode is set may be prohibited. This makes it possible to meet the demands of users who desire to prioritize night-time boiling operation.

The selection means provided in the remote controller 44 may be provided in another configuration such as a communication adapter 46, a photovoltaic power generation facility 47, or an energy management device 48. Even if the user permits the use of surplus power by operating the selection means, the surplus power is not always used. This is because when the power contract mode is set to the night time zone priority mode, the normal mode is set, so that the boiling amount of the night boiling operation is not reduced. Therefore, when the use of surplus power is permitted and the night time zone priority mode is set, the surplus power cannot be used, that is, the boiling amount of the night boiling operation is not reduced. May be provided on the display unit of the remote controller 44. In addition, if the use of surplus power is permitted and the night time zone priority mode is not set, the surplus power can be used, that is, the amount of boiling in the night boiling operation is reduced. A notification means for displaying on the display unit of the remote controller 44 may be provided. This makes it possible to effectively notify the user whether or not the surplus power can be used.

The control device 36 may include a switching means for switching between enabling and disabling the normal mode. Such switching means can be realized, for example, by providing the remote controller 44 with means for switching between valid and invalid of the normal mode. According to such a configuration, the user can arbitrarily set the utilization of the surplus power.

1 Compressor, 3 Water refrigerant heat exchanger, 4 Expansion valve, 5 Coolant circulation piping, 6 Air heat exchanger, 7 Heat pump unit, 8 Hot water storage tank, 8a Water inlet, 8b Water outlet, 8c Hot water inlet, 8d Hot water introduction outlet, 9 water supply pipe, 9a first water supply pipe, 9b second water supply pipe, 9c third water supply pipe, 10 water outlet pipe, 11 three-way valve, 12 circulation pump, 13 hot water supply pipe, 14 heat pump outbound pipe , 15 Heat pump return piping, 16 1st bypass piping, 17 2nd bypass piping, 18 4-way valve, 20 bath heat exchanger, 20a hot water introduction piping, 20b hot water outlet piping, 21 hot water supply piping, 22 hot water supply mixing valve, 23 Mixing valve for bath, 24 1st hot water supply pipe, 25 2nd hot water supply pipe, 26 Electromagnetic valve for bath, 27 Bath back pipe, 28 Bath return pipe, 29 Circulation pump, 30 Bathtub, 31 Pressure reducing valve, 33 Tank unit, 35 Hot water storage Type water heater, 36 control device, 37,38 temperature thermistor, 42,43 temperature thermister, 44 remote control, 45 flow sensor for bath, 46 communication adapter, 47 solar power generation equipment, 48 energy management device

Claims (7)

A heating means that is connected to each of the photovoltaic power generation equipment and the grid power equipment and heats water by the power supplied from the photovoltaic power generation equipment or the grid power equipment to generate hot water, and a heating means generated by the heating means. In a hot water storage type water supply machine equipped with a hot water storage tank for storing hot water,
As the boiling operation in which hot water is generated by the heating means and stored in the hot water storage tank, the daytime boiling operation using the electric power supplied from the photovoltaic power generation facility during the daytime and the system power during the nighttime Equipped with a control device that performs night-time boiling operation using the electric power supplied from the equipment.
The control device sets the power contract mode to nighttime corresponding to the power contract when the power contract currently set is a power contract in which the unit price of power during the night time is lower than the unit price of power during the daytime. includes setting means for setting the time zone priority mode,
When the night time zone priority mode is set by the setting means, a normal mode in which the boiling amount of the night boiling operation is increased as compared with the case where the night time zone priority mode is not set is performed. A hot water storage type water heater characterized by being configured to run. The control device further includes a predictive means for predicting the presence or absence of surplus electric power generated by the photovoltaic power generation facility on the next day, which is electric power that can be used for the daytime boiling operation, and prioritizes the nighttime time zone. When the mode is not set and the prediction means predicts that there will be surplus power for the next day, the boiling of the night boiling operation will be higher than when it is predicted that there will be no surplus power for the next day. The hot water storage type water supply machine according to claim 1, which is configured to reduce the amount of increase. When the nighttime time zone priority mode is not set and it is predicted that there is no surplus power on the next day, the control device sets the boiling amount of the nighttime boiling operation to the nighttime time zone priority mode. The hot water storage type water heater according to claim 2, wherein the amount is the same as that in the case where is set. When the night time zone priority mode is set, the control device reduces the boiling amount of the daytime boiling operation as compared with the case where the night time zone priority mode is not set. The hot water storage type water heater according to any one of claims 1 to 3, wherein the water heater is configured. Any one of claims 1 to 3, wherein the control device is configured to prohibit the daytime boiling operation when the nighttime time zone priority mode is set. The hot water storage type water heater described in the section. The control device is a selection means for selecting permission or prohibition of use of surplus electric power which is electric power that can be used for the daytime boiling operation among the electric power generated by the photovoltaic power generation facility.
When the use of the surplus power is permitted, the notification means for notifying the availability of the surplus power according to whether or not the night time zone priority mode is set, and the notification means.
The hot water storage type water heater according to any one of claims 1 to 5, wherein the water heater comprises. The hot water storage type water heater according to any one of claims 1 to 6, wherein the control device includes a switching means for switching between enabling and disabling the execution of the normal mode.

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