JP2010216723A - Hot water supply system and method for operating the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a system and a method capable of stably supplying hot water regardless of weather, and reducing power cost. <P>SOLUTION: This hot water supply system includes a hot water storage unit 10, a solar panel 11, and a heat pump unit 12 including a heat absorbing means 15 absorbing the heat of the outside air and applying it to a heat medium, a compressing means 16 which is driven by being fed with power and compresses the heat medium, a heating means 17 for heating the water or hot water supplied from the hot water storage unit 10 by the compressed heat medium and returning it to the hot water storage unit 10, and an expanding means 18 for expanding the compressed heat medium and supplying it to the heat absorbing means 15. The water received by the hot water storage unit 10 at night is heated to a set temperature to be directly usable as hot water by commercial power, and the hot water in the hot water storage unit 10 is further heated by power from the solar panel 11 in the daytime. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a hot water supply system using solar power generation and a method for operating the hot water supply system.

  In hospitals, recreation centers, homes, etc., boilers and water heaters are used as hot water supply devices. This boiler or hot water heater is a device that heats water by burning fuel such as heavy oil, light oil, LPG, city gas, etc., and applying heat generated thereby to water. However, these devices generate carbon dioxide by burning fuel and discharge it into the atmosphere, which causes air pollution and global warming.

  In order to remove the cause and improve the global environment, energy saving of products and facilities and reduction of greenhouse gas emissions are being attempted. As one of the hot water supply systems, a heat cycle system using a heat pump has been proposed (see, for example, Patent Document 1).

  The heat pump includes a heat exchanger that exchanges heat between the outside air and the heat medium, a compressor that compresses the heat medium that has undergone heat exchange and a temperature increase, and heat between the compressed heat medium and the object to be heated. The heat exchanger to be exchanged and an expansion valve that expands the heat medium in a compressed state although the temperature is lowered are provided.

  In this Patent Document 1, water is used as a heat medium, and heat is exchanged with the exhaust gas discharged from the boiler in order to prevent the outside air from becoming a low temperature and being unable to exchange heat with the heat exchanger. It is possible. Note that the heat pump is efficient in that heat about three times the power consumption can be effectively used because it is sufficient to give only the energy required to move the heat medium. Moreover, since it does not use liquid fuel, it is not greatly affected by its market price.

  A hot water supply system using solar power generation has also been proposed (see, for example, Patent Document 2). This hot water supply system is a system that combines a solar power generation system and a hot water supply device. The solar battery, power conditioner, distribution board, and commercial power system are connected to the grid, and the indoor load and hot water supply equipment are connected to the distribution board. It is configured as a hot water supply system using solar power generation that supplies electricity to the power source.

  In this system, the power conditioner has a voltage rise suppression function so that it does not exceed the specified voltage value, and the power generation amount of the solar cell exceeds the standard value and exceeds the specified voltage value of the power conditioner. Occasionally, the voltage rise suppression function works to supply excess AC power to the hot water supply device via the power supply line, and input the signal via the communication line to operate the hot water supply device in the daytime, maximizing the solar power generation power It can be effectively used as much as possible to eliminate the loss and reduce the commercial power supplied to the hot water supply device at midnight.

In addition, a CO ₂ cycle drive device using solar power generation that can be used without any trouble even in an unstable power situation and can efficiently use energy has been proposed (see Patent Document 3). This device is formed by connecting a compressor, a gas cooler, an expansion valve, an evaporator and the like in an annular shape, using carbon dioxide as a refrigerant, a refrigerant circuit that can be a supercritical pressure on the high pressure side, a solar cell, and a water storage tank, The electric power generated in the solar cell is applied to the compressor for operation.

JP 2008-8581 A JP 2006-29635 A JP 2007-85685 A

  In the conventional hot water supply system, it is necessary to supply electric power to the compressor in order to drive the heat pump, but usually, inexpensive commercial electric power is supplied at midnight. In ordinary households, hot water is used for cooking, facial washing and bathing, and the usage hours are often in the morning and at night. For this reason, it is necessary to heat the hot water to a temperature sufficiently higher than the normal use temperature so as to keep the temperature of the hot water at a predetermined temperature until that night, and accordingly, power is consumed and power cost is increased. .

  In the technique described in Patent Document 2, when the function of suppressing the voltage increase of the power conditioner is activated, an excess amount exceeding the specified voltage value of the amount of power generated by the solar cell is supplied to the hot water supply device to operate the hot water supply device during the daytime. Therefore, when the voltage regulation value is not exceeded, the hot water supply device is not operated during the daytime. For this reason, in order to operate the hot water supply apparatus, as described above, it is necessary to supply commercial power for heating to a temperature sufficiently higher than the normal use temperature.

  In the technique described in Patent Document 3, the electric power generated by the solar battery is applied to the compressor driving motor and operated, and the water in the water tank is heated, and the surplus electric power is stored in the storage battery. Since the compressor is operated by discharging from the storage battery, sufficient energy saving can be achieved, and the amount of greenhouse gas emissions can be reduced. However, when it is rainy and cloudy, a sufficient amount of power generation cannot be obtained, there is a problem that water cannot be heated and hot water cannot be made.

  Therefore, when a hot water supply system is configured by combining a solar panel that performs solar power generation and a heat pump, it is possible to stably supply hot water in any weather and to sufficiently save energy. It is desirable to provide a system and method that can reduce power costs.

  As a result of intensive studies, the inventors of the present invention can generate power even when it is rainy and cloudy, so when operating the heat pump unit with inexpensive commercial power at night, it is heated to a temperature that can be used directly as hot water. In the daytime, the heat pump unit is operated with the electric power generated by the solar panel and further heated so that it can reduce power consumption compared to the conventional hot water supply system. It was.

  This invention is made | formed by discovering these things, The said subject can be solved by providing the hot-water supply system of this invention, and its operating method.

  The hot water supply system includes a hot water storage unit that receives water and supplies hot water, a solar panel that performs solar power generation, and a heat pump unit. The heat pump unit includes heat absorption means that absorbs heat from the outside air and applies the heat to the heat medium, compression means that is driven by being supplied with power and compresses the heat medium, and water or hot water supplied from the hot water storage unit by the compressed heat medium. Heating means for heating and returning to the hot water storage unit, and expansion means for expanding the compressed heat medium and supplying it to the heat absorption means. This system heats the water received by the hot water storage unit at night to a set temperature that can be directly used as hot water by commercial power, and further heats the hot water in the hot water storage unit by power from the solar panel during the day. And

  Heating up to the minimum required temperature for commercial power and covering the rest with the power generated by the solar panel can reduce power consumption, reduce power costs, and stabilize Hot water can be supplied.

  In this hot water supply system, the solar panel and the heat pump unit are connected via a distribution board, the hot water in the hot water storage unit is heated to a target temperature, and the temperature of the hot water in the hot water storage unit is above a threshold temperature for a certain time. In some cases, it may further include switching means for stopping power supply from the solar panel to the compression means and supplying power to other indoor electrical equipment. Thereby, the surplus part of electric power can be sent to another electric equipment, and the consumption amount of commercial electric power can be reduced.

  Furthermore, the hot water supply system can further include a water supply means for supplying water to the hot water storage unit. When power is supplied from the solar panel to other indoor electrical equipment, the switching means switches to power supply to the compression means in response to the remaining hot water amount in the hot water storage unit being less than the preset amount. The water supply means can supply a certain amount of water. Thereby, hot water can be used without worrying about the consumption of hot water and the consumption of commercial power.

  The operation method of the hot water supply system is to supply water to the hot water storage unit, and at night, supply commercial power to the compression means to compress the heat medium, and supply water supplied from the hot water storage unit by the compressed heat medium, Heating to a set temperature that can be directly used as hot water, and hot water supplied from the hot water storage unit by the compressed heat medium by compressing the heat medium by supplying power to the compression means from the solar panel that performs solar power generation in the daytime Further heating.

  In this operation method, the solar panel and the heat pump unit are connected via a distribution board, the hot water in the hot water storage unit is heated to a target temperature, and the temperature of the hot water in the hot water storage unit is a threshold temperature for a certain time. In the case described above, it is possible to include a step of stopping power supply from the solar panel to the compression means by the switching means and supplying power to other electric devices in the room.

  Furthermore, when power is supplied from the solar panel to other indoor electrical equipment, the switching means supplies power to the compression means in response to the amount of remaining hot water in the hot water storage unit being equal to or less than a preset amount. And a step in which the water supply means supplies a certain amount of water.

The figure which showed one structural example of the hot water supply system. The figure which showed another structural example of the hot water supply system. The figure which showed another structural example of the hot water supply system.

  The hot water supply system of the present invention uses inexpensive commercial power at night to heat to the minimum necessary temperature, and then heats using power generated by the solar panel in the daytime. Even if it is rainy, some power can be generated, so that the hot water used for bathing on the night of the day has a sufficient hot water temperature and can be reheated as needed. Moreover, even when using it for cooking on the morning of the day, since it is heated to the minimum required temperature, it can be used by directly supplying hot water.

  FIG. 1 is a diagram showing one configuration example of a hot water supply system. The hot water supply system includes a hot water storage unit 10 that receives water and supplies hot water, a solar panel 11 that performs solar power generation, and a heat pump unit 12.

  The hot water storage unit 10 is a container that can store a predetermined amount of hot water, and includes a nozzle for water supply, a nozzle for hot water supply, a nozzle for supplying water or hot water to the heat pump unit 12, and hot water that is heated and returned. It has four nozzles, a receiving nozzle. Moreover, the hot water storage unit 10 is installed outdoors, and a heat insulating material or the like is wound around the outer surface so as to prevent the stored hot water from being cooled by heat radiation.

  Moreover, the hot water storage unit 10 can be equipped with a thermometer so that the temperature of hot water inside can be measured, and can also be equipped with a liquid level gauge (level gauge) so that the amount of hot water can be measured.

  The solar panel 11 is an electric power device that is installed on the roof and converts the light energy directly into electric power by utilizing the effect of excitation of electrons inside the substance, that is, the photovoltaic effect, and a necessary voltage by connecting a plurality of series in parallel. And it is supposed that current can be obtained. There are many types depending on the material of the light-absorbing layer and the form of the element. For example, silicon-based solar cells using crystalline silicon, amorphous silicon, or laminates thereof, and dyes such as ruthenium complexes are used. Dye-sensitized solar cells using organic dyes with a structure in which an adsorbed titanium dioxide layer and an electrolytic layer are sandwiched, organic thin-film solar cells using organic thin-film semiconductors combined with conductive polymers, fullerenes, etc., single-crystal gallium arsenide A GaAs-based solar cell using (GaAs) can be given.

  These solar cells directly convert light energy into electric power. That is, electrons inside a substance such as silicon are excited by incident light, and the excited electrons are guided to an electrode and taken out as a direct current.

  Since the heat pump unit 12 fed with power from the solar panel 11 uses alternating current, it is necessary to convert direct current into alternating current. Therefore, a power conditioner 13 is provided between the solar panel 11 and the heat pump unit 12. The power conditioner 13 can convert the same AC power as commercial power.

  A distribution board 14 can be provided between the power conditioner 13 and the heat pump unit 12. The distribution board 14 can switch or branch the power from the solar panel 11 to supply not only the heat pump unit 12 but also other electric devices such as the refrigerator shown in FIG. It is also possible to send surplus power to the commercial power system for sale. Further, even when there is almost no electric power supplied to other electric devices and no electric load is generated indoors, the electric power generated by the solar panel 11 can be sent to the commercial power system of the electric power company for sale. it can. The distribution board 14 switches the power supply from the solar panel 11 at night, and also enables supply of commercial power to the heat pump unit 12.

  The heat pump unit 12 is installed outdoors side by side with the hot water storage unit 10, and is driven by heat absorption means 15 that absorbs heat from the outside air and supplies it to the heat medium, commercial power is supplied at night, and power is supplied from the solar panel during the day. , Compression means 16 for compressing the heat medium, heating means 17 for heating water or hot water supplied from the hot water storage unit 10 by the compressed heat medium, and returning the hot water to the hot water storage unit 10, and expanding the compressed heat medium, Expansion means 18 for supplying heat absorption means 15.

  The heat absorption means 15 is provided with a ventilation fan that takes in outside air and discharges the internal air, and transfers the heat of the taken outside air to the heat medium to warm the heat medium. Therefore, the heat absorption means 15 includes a heat exchanger that exchanges heat between the outside air and the heat medium, and causes the heat medium to flow in the tube, bringing the outside air into contact with the tube, and giving the heat of the outside air to the heat medium in the tube. In order to improve the heat conduction efficiency in the heat exchanger, the heat transfer area can be increased. For example, a tube through which a heat medium flows can be formed in a coil shape, or fins can be provided on the surface of the tube. As the heat medium, a gas that can take a large compression ratio and greatly increases in temperature due to the compression is preferable, and examples thereof include air and carbon dioxide.

  The compression unit 16 compresses the heat medium warmed by the heat absorption unit 15. Since the compression performed by the compression means 16 is polytropic compression close to adiabatic compression, the discharge temperature rises depending on the compression ratio. For example, when air is used as the heat medium and air of about 0.1 MPa and about 20 ° C. is compressed to about 0.7 MPa, if there is no heat exchange with the outside, all the energy applied for the compression is all The temperature rises to about 260 ° C. in theory, but in reality, there is a heat loss, which is about 170 to 200 ° C. Although there is a heat loss, the temperature is higher than 100 ° C., so that water can be sufficiently heated. As the compression means 16, a volumetric compressor is preferable, and examples thereof include a reciprocating compressor and a diaphragm compressor.

  The heat medium thus compressed and brought to a high temperature is sent to the heating means 17 and gives the heat to the water supplied to the hot water storage unit 10. The heating means 17 can be a heat exchanger, and can be coiled or provided with fins in order to increase the heat transfer area.

  The heat medium whose temperature is lowered by applying heat to the water in the heating means 17 is maintained in a compressed state, and the temperature does not drop below the temperature of the hot water stored in the hot water storage unit 10. Thus, the heat absorption means 15 cannot absorb the heat of the outside air. Therefore, the temperature is expanded by the expansion means 18 to lower the temperature. As the expansion means 18, an expansion valve can be used. In the expansion means 18, when the pressure is increased from about 0.1 MPa to about 0.7 MPa by the compression means 16, the pressure can be reduced from about 0.7 MPa to about 0.1 MPa.

  In this hot water supply system, water is supplied to the hot water storage unit 10 by water supply means at night, but about 35 usable as direct hot water by supplying cheap commercial power at night to the compression means 16 provided in the heat pump unit 12. Heat to a set temperature of from ℃ to about 43 ℃. In the daytime, the hot water in the hot water storage unit 10 is further heated by feeding the power generated by the solar panel 11.

  The hot water supply system can be supplied with water via a hot water supply pipe 19 connected to the hot water storage unit 10, and the hot water supply system can supply hot water to a bathroom or the like via a hot water supply pipe 20 connected to the hot water storage unit 10. In FIG. 1, hot water is supplied to the bathroom, but hot water is also supplied to the kitchen, dresser, and the like. The water supply pipe 19 and the hot water supply pipe 20 are wound with a heat insulating material so that the water flowing inside does not freeze and the hot water supply temperature does not drop, so that the heat is not dissipated to the outside. .

  The hot water storage unit 10 and the heat pump unit 12 may be installed at any location, but preferably installed at a location where there is little wind flow. This is because warm air as much as possible can absorb more heat in the heat absorbing means 15, and if the temperature of the heat medium increases, water can be heated sufficiently without being compressed so much. This is because the temperature can be set, and as a result, power consumption can be reduced.

  For example, if the night is from 23:00 to 6:00 the next morning, water is supplied to the hot water storage unit 10 during or before that time. And the commercial power supplied from an electric power company is supplied to the heat pump unit 12 in the night time zone, the compression means 16 is operated, and it heats even to said set temperature. Thereafter, the electric power obtained from the solar panel 11 is switched, and the solar panel 11 supplies power to the heat pump unit 12 to operate the compression means 16 to further heat the hot water in the hot water storage unit 10.

  Although the hot water supply unit having the above-described configuration can be provided, the amount of power generated by the solar panel 11 may be excessive when the amount of solar radiation is high in summer or when the sunshine hours are long. For this reason, the distribution board 14 is provided with switching means such as a switching device, and surplus power can be supplied to other electrical products such as cooling equipment such as a cooler, a television, a refrigerator, a personal computer, and lighting. If there is still a surplus, it is possible to reverse power to the commercial power system and sell it. Further, even when there is almost no electric power supplied to other electric devices and no electric load is generated indoors, the electric power generated by the solar panel 11 can be sent to the commercial power system of the electric power company for sale. it can.

  FIG. 2 is a diagram illustrating a configuration example of a hot water supply system that can be switched by the switching unit. Although it is possible to switch manually, it is also possible to switch automatically as in the embodiment shown in FIG.

  In the nighttime, commercial power is supplied to the heat pump unit 12 to operate the compression unit 16, but in the daytime, the compression unit 16 is operated by supplying electric power generated by the solar panel 11. During the summer season when the amount of solar radiation is large, the hot water temperature in the hot water storage unit 10 easily rises to the target temperature by this operation. The target temperature can be about 60 ° C to about 90 ° C. Heating at 90 ° C. or higher is not necessary for additional cooking. Further, since water evaporates and the internal pressure in the hot water storage unit 10 rises, there is a risk of explosion, so it is necessary to limit the heating.

  Therefore, when the hot water temperature in the hot water storage unit 10 reaches the target temperature and is equal to or higher than a preset threshold temperature for a certain time, it is determined that the temperature condition in the hot water storage unit 10 is stable, and the solar panel 11 The switching means 21 switches the electric power obtained by power generation and supplies power to other electrical products such as a cooling facility such as a refrigerator and a cooler, a television, a personal computer, and lighting.

  The switching means 21 acquires the hot water temperature as data from the thermometer T provided in the hot water storage unit 10, and when the hot water temperature is equal to or higher than the threshold temperature for a certain time, from the power supply to the heat pump unit 12, Switch to power supply to other electrical products. The certain time is necessary to see that the hot water temperature is stable, and the time may be any time, but during that time, the hot water in the hot water storage unit 10 is continuously heated, so that the time is too long. Time is not preferred. For example, it may be 5 minutes.

  The switching means 21 can acquire the hot water temperature by periodically sending a temperature acquisition request to the thermometer and returning the hot water temperature measured by the thermometer as data. The switching means 21 holds the threshold temperature as data, compares the acquired hot water temperature with this threshold temperature, and determines whether or not the temperature is equal to or higher than the threshold temperature. For this reason, the switching means 21 includes a circuit including a CPU and a memory. The switching means 21 is fed with commercial power or power obtained from the solar panel 11. The threshold temperature is a temperature lower than the target temperature and is a lower limit temperature. Considering the additional cooking, it can be set to about 50 ° C to about 60 ° C.

  In addition, when another switching means is provided so that the electric power obtained from the solar panel 11 can be used for electric appliances indoors, power is supplied to the commercial power system of the power company by the other switching means, can do. Further, even when there is almost no electric power supplied to other electric devices and no electric load is generated indoors, the electric power generated by the solar panel 11 can be sent to the commercial power system of the electric power company for sale. it can.

  FIG. 3 is a diagram showing another configuration example of the hot water supply system that can be switched by the switching means 21. The water supply pipe 19 is provided with a water supply valve or the like as the water supply means 22, and can open a water supply valve as necessary to supply a certain amount of water. In addition, the water supply means 22 is not restricted to a water supply valve, A water supply pump etc. may be sufficient. In addition, when the solar panel 11 is a solar cell using silicon, the band gap is reduced at a high temperature and the output voltage is lowered. Therefore, the solar panel 11 is cooled with cooling water, and water heated thereby is supplied. It is also possible.

  The switching means 21 acquires not only the hot water temperature from the thermometer T but also the liquid level from the liquid level gauge L as data, and determines whether or not the remaining hot water amount in the hot water storage unit 10 is less than or equal to the set amount. As described above, if the hot water temperature is equal to or higher than the threshold temperature, power is supplied to other electrical appliances in the room. However, when it is detected that the remaining hot water amount has become the set amount or less, the heat pump unit 12 is again supplied. Electric power is supplied to operate the compression means 16 and the water supply means 22 starts supplying a certain amount of water. The set amount may be any amount, but it can be set to, for example, about 20% to about 60% of the capacity of the hot water storage unit 10 in consideration of the use at the time of bathing that night.

  When a certain amount of water is supplied, the hot water temperature in the hot water storage unit 10 decreases, but the electric power obtained from the solar panel 11 is supplied to the heat pump unit 12 to heat the hot water in the hot water storage unit 10, thereby reducing the hot water temperature. It can be maintained at or above the previous temperature. In addition, by using the water supply means 22, it can supply water as needed. This water supply can increase the amount of hot water while maintaining the hot water temperature substantially constant by adjusting the water supply speed.

  In this operation, when power is supplied from the solar panel 11 to other indoor electrical equipment, it is detected that the remaining hot water amount in the hot water storage unit 10 is less than or equal to a preset set amount, and the switching means 21 Is switched to power feeding to the compression means 16, and the switching means 21 instructs the water supply means 22 to cause the water supply means 22 to supply a certain amount of water. If the water supply means 22 is a water supply valve, the switching means 21 can supply a fixed amount of water by instructing to open the valve by specifying the valve opening.

  The hot water supply system and the operation method thereof according to the present invention have been described in detail with reference to the embodiments shown in the drawings, but the present invention is not limited to the above-described embodiments, and other embodiments and Additions, changes, deletions, and the like can be made within the scope that can be conceived by those skilled in the art, and any aspect is included in the scope of the present invention as long as the effects and advantages of the present invention are exhibited. .

DESCRIPTION OF SYMBOLS 10 ... Hot water storage unit, 11 ... Solar panel, 12 ... Heat pump unit, 13 ... Power conditioner, 14 ... Distribution board, 15 ... Heat absorption means, 16 ... Compression means, 17 ... Heating means, 18 ... Expansion means, 19 ... Water supply Pipe, 20 ... Hot water supply pipe, 21 ... Switching means, 22 ... Water supply means

Claims (6)

A hot water supply system for supplying hot water,
A hot water storage unit that accepts water and supplies hot water;
Solar panels for solar power generation,
Heat absorption means that absorbs heat from outside air and applies it to the heat medium, compression means that is driven by being supplied with power and compresses the heat medium, and water or hot water supplied from the hot water storage unit by the compressed heat medium A heat pump unit including heating means for heating and returning to the hot water storage unit, and expansion means for expanding the compressed heat medium and supplying the heat medium to the heat absorption means,
The water received by the hot water storage unit at night is heated to a set temperature that can be directly used as hot water by commercial power, and the hot water in the hot water storage unit is further heated by power from the solar panel during the day. A hot water supply system.   The solar panel and the heat pump unit are connected via a distribution board, and the hot water in the hot water storage unit is heated to a target temperature in the daytime, and the temperature of the hot water in the hot water storage unit is equal to or higher than a threshold temperature for a certain time. 2. The hot water supply system according to claim 1, further comprising a switching unit configured to stop power feeding from the solar panel to the compression unit and to feed power to other indoor electrical equipment.   The hot water supply system includes water supply means for supplying water to the hot water storage unit, and when the solar panel is supplying power to the other electrical equipment in the room, the remaining hot water amount in the hot water storage unit is equal to or less than a preset set amount. 3. The hot water supply system according to claim 2, wherein the switching unit switches to power supply to the compression unit and the water supply unit supplies a certain amount of water in response to the change. A method of operating a hot water supply system for supplying hot water,
Supplying water to the hot water storage unit;
At night, commercial power is supplied to the compression means of the heat pump unit to compress the heat medium, and the water supplied from the hot water storage unit is heated to a set temperature that can be used directly as hot water by the compressed heat medium. And the stage of
Supplying hot water from a solar panel that performs solar power generation to compress the heat medium in the daytime and further heating the hot water supplied from the hot water storage unit by the compressed heat medium. How to operate the system.   The solar panel and the heat pump unit are connected via a distribution board to heat the hot water in the hot water storage unit to a target temperature during the daytime, and the temperature of the hot water in the hot water storage unit is a threshold temperature for a certain time The operation method of the hot water supply system according to claim 4, further comprising the step of stopping power supply from the solar panel to the compression means by the switching means and supplying power to other electrical equipment indoors. The hot water supply system includes water supply means for supplying water to the hot water storage unit,
In the case where power is supplied from the solar panel to the other electrical equipment in the room, in response to the remaining hot water amount in the hot water storage unit being equal to or less than a preset set amount, the switching means is the compression means. The method for operating a hot water supply system according to claim 5, further comprising a step of switching to power supply to the power supply, and a step of supplying the water supply means with a certain amount of water.

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