JP2006029635A - Hot-water supply system utilizing photovoltaic power generation - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a hot-water supply system utilizing photovoltatic power generation capable of operating a hot-water supply device when a power conditioner suppresses an increase in voltage and storing the excess electric power energy of photovoltaic power generation electric power being loss conventionally as heat energy. <P>SOLUTION: A solar battery 1, the power conditioner 2, a distribution board 3, and an electric power system 5 for a commercial use are linked in system and constitute the hot-water supply system utilizing the photovoltatic power generation for feeding electricity to an indoor load 4 and the hot-water supply device 6 from the distribution board 3. The power conditioner 2 is provided with a voltage increase suppressing function for preventing a voltage from exceeding a predetermined voltage specified value. When an amount of the power generation of the solar battery 1 exceeds a standard condition and is larger than the voltage specified value of the power conditioner 2, the voltage increase suppressing function functions to feed excess alternate current electric power to the hot-water supply device 6 through an electric supply line 8 and operate the hot-water supply device 6 in the daytime by inputting a signal through a communication line 7. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a hot water supply system using solar power generation that combines a solar power generation system and a hot water supply apparatus.

  Conventionally, solar power is used to generate direct-current power from sunlight, this direct-current power is converted into alternating current by an inverter such as a power conditioner, and then output and supplied to an indoor load via a distribution board. There is known a photovoltaic power generation system in which power is reversely flowed (sold) to the commercial power system side through grid connection. In addition, hot water supply devices are operated by using inexpensive commercial power at midnight and hot water is stored in a hot water storage tank. Hot water stored in the hot water tank is used for hot water supply during the day and at night. Conventionally, a hot water supply system using solar power generation in which such a solar power generation system and a hot water supply device are combined is also known, and a typical example thereof is a DC power generated by the solar cell 1 as shown in FIG. The inverter 2 converts and outputs the alternating current and supplies power to the indoor load 4 via the distribution board 3, and in the middle of the night, cheap commercial power is supplied from the commercial power system 5 to the hot water supply device 6 via the distribution board 3. It is operated by supplying power, boiling water and storing it in a hot water tank (not shown).

Moreover, the example using the heat pump as a hot water storage apparatus is described in patent document 1 and patent document 2, for example. In the case of Patent Document 1, a plurality of types of heating means including a heat pump are provided, and one of these heating means is selected or combined to be operated. In the case of Patent Document 2, commercial power is supplied at midnight, converted to DC power by a rectifier, supplied to an inverter, adjusted to an appropriate frequency by an inverter / system interconnection protection control device, and then supplied to a compressor drive unit Thus, the inverter is operated.
JP 2002-22270 A JP-A-8-265888

  In the conventional typical hot water supply system using solar power generation, when the amount of solar radiation is large and the power generation capacity of the solar cell is high, the power generation amount increases and a predetermined voltage (101V ± 6V is defined by the Electricity Business Act). May be exceeded). Moreover, even if the power generation amount of the solar cell is not the maximum, the predetermined voltage may be exceeded. When photovoltaic power generation houses are concentrated nearby, the degree of voltage rise tends to increase. If the voltage increases, electrical appliances may break down, so it is necessary not to exceed a predetermined voltage during reverse power flow, and the power conditioner must have a voltage rise suppression function. There is. When the voltage rise suppression function of the power conditioner works, there is a problem that loss occurs because the electric power generated by the solar cell is reduced.

  The present invention has been made to solve such a problem in the prior art, and when the voltage rise suppression function of the power conditioner works, the excess amount exceeding the voltage regulation value of the amount of power generated by the solar cell is supplied with hot water. The purpose is to provide a hot water supply system using solar power generation that can be used effectively by supplying power to the device and operating the hot water supply device to store the solar power generation energy, which has conventionally been a loss, in place of thermal energy. And

  As a means for achieving this object, the hot water supply system using solar power generation according to claim 1 of the present invention supplies power generated by a solar cell to an indoor load via a power conditioner and a distribution board. In addition, in a system in which surplus power is reversely flowed to the commercial power system and power is supplied from the commercial power system to an indoor load or hot water supply device via the distribution board, the amount of power generated by the solar cell is large. When the specified voltage value of the power conditioner is exceeded, electric power that exceeds the specified voltage value of the power conditioner among the generated power of the solar battery is supplied to the hot water supply device, and the hot water supply device is operated in the daytime. It is characterized by that.

  The hot water supply system using solar power generation according to claim 2 of the present invention supplies power generated by a solar battery to an indoor load through a power conditioner and a distribution board, and surplus power is supplied to the commercial power system side. A power supply line for supplying electric power from the power conditioner to the hot water supply device in a system for supplying electric power from a commercial power system to an indoor load or hot water supply device via the distribution board. When the power generation amount of the solar cell is large and exceeds the voltage regulation value of the power conditioner, the power for the power exceeding the voltage regulation value of the power conditioner among the generated power of the solar cell is supplied to the feeder line. Power is supplied to the hot water supply device, and the hot water supply device is operated in the daytime.

  The hot water supply system using solar power generation according to claim 3 of the present invention is the hot water supply system using solar power generation according to claim 1 or claim 2, wherein the hot water supply device includes a compressor, a gas cooler, a decompressor, and an evaporator. It is characterized in that water can be heated by a heat pump using carbon dioxide as a working medium while being connected to a pipe in an annular shape.

  According to the hot water supply system using solar power generation according to claim 1, when the amount of solar radiation is large, the power generation performance of the solar cell is high, and power generation exceeding a predetermined voltage is performed, the power condition is included in the power generation power of the solar cell. Since the electric power exceeding the specified voltage value is fed to the hot water supply device and operated in the daytime, the solar power generation power can be used to the maximum extent to eliminate the loss that has occurred in the past and to the hot water supply device at midnight. Commercial power to be fed can be reduced.

  According to the hot water supply system using solar power generation according to claim 2, when the amount of solar radiation is large, the power generation performance of the solar cell is high, and when power generation exceeding a predetermined voltage is performed, the power condition is included in the power generation power of the solar cell. It is possible to operate in the daytime by supplying the amount of power exceeding the specified voltage value of the na to the hot water supply device via the feeder line. Because a dedicated power supply line is used, there are few failures and maintenance and inspection work is easy. And the loss which has arisen conventionally by using solar power generation power to the maximum effectively can be eliminated, and the commercial power supplied to the hot water supply device at midnight can be reduced.

  According to the hot water supply system using solar power generation according to the third aspect, the hot water supply apparatus is configured by connecting a compressor, a gas cooler, a decompressor, and an evaporator in a ring shape, and a heat pump using carbon dioxide as a working medium. Therefore, it has high performance, and the working medium is a natural refrigerant, is environmentally friendly, non-toxic, and non-flammable, so it can be used safely.

  Next, an embodiment of a hot water supply system using solar power generation according to the present invention will be described with reference to the accompanying drawings. FIG. 1 is a block diagram showing an embodiment of a hot water supply system using solar power generation according to the present invention. FIG. 2 is a flowchart showing an example of operation control in the hot water supply system using solar power generation according to the present invention.

  In this embodiment, the same components as those in the conventional example are described with the same reference numerals as those described above. In FIG. 1, reference numeral 1 denotes a solar cell, which is usually attached to the roof of a building or a roof of a detached house. Since the structure and the power generation principle of the solar cell 1 are known, the description thereof is omitted.

  A power conditioner 2 is connected between the solar cell 1 and the distribution board 3. As is well known, this power conditioner 2 is a unit in which an electronic power conversion device such as an inverter and a control / protection system are integrated as a unit, and DC power generated by the solar cell 1 is used as commercial power. It is possible to convert the same AC power into the same voltage and has a voltage rise suppression function so as not to exceed a predetermined voltage regulation value.

  The distribution board 3 is connected to the commercial power system 5 so that the power of the photovoltaic power generation system and the commercial power can be interconnected to use both powers. As a result, when the generated power is insufficient in the photovoltaic power generation system at night or when it is raining, the power can be backed up from the commercial power system 5 side, and when the generated power is excessive in the photovoltaic power generation system, Surplus power can be reversely flowed to the commercial power system 5 side.

  Reference numeral 4 denotes an indoor load connected to the distribution board 3 and includes various electric appliances such as a television set, a refrigerator, and an air conditioner installed indoors, lighting, and the like. A hot water supply device 6 connected to the distribution board 3 is usually operated by supplying inexpensive commercial power from the commercial power system 5 at midnight. This hot water supply apparatus 6 has a refrigeration cycle in which a compressor, a gas cooler, a decompressor, and an evaporator (not shown) are connected in an annular shape as is well known and is a heat pump type. It is made warm water by heating with, and this warm water is stored in the hot water tank. Then, the hot water stored in the hot water storage tank is supplied from the hot water supply device 6.

  Since carbon dioxide is used as the working medium of the refrigeration cycle in the hot water supply apparatus 6, the transcritical refrigeration cycle apparatus is capable of providing a supercritical pressure on the high pressure side. When carbon dioxide is used as the working medium, the performance of the heat pump can be improved, and since it is a natural refrigerant, it is environmentally friendly, non-toxic and non-flammable, so it can be used safely.

  Reference numeral 7 denotes a communication line that connects the power conditioner 2 and the hot water supply device 6, and a signal for operating the hot water supply device 6 when the voltage rise suppression function is activated in the power conditioner 2 via the communication line 7. When the voltage rise suppression function stops, a signal for stopping the hot water supply device 6 is issued. A power supply line 8 connects the power conditioner 2 and the hot water supply device 6. The use of the dedicated power supply line 8 reduces the number of failures and facilitates maintenance and inspection work.

  In the hot water supply system using solar power generation configured as described above, the DC power generated by the solar battery 1 is converted and boosted to AC power by the power conditioner 2 when the power generation capacity of the solar battery 1 is in a standard state. Then, power is transmitted to the distribution board 3 and the indoor load 4 is fed from the distribution board 3. If the power generation amount of the solar cell 1 exceeds the power consumption of the indoor load 4 and is equal to or less than the voltage regulation value of the power conditioner 2, the surplus power is reversed to the commercial power grid 5 side by grid connection. Let the tide flow. When the power generation capacity of the solar cell 1 is below standard at night or due to rain or cloudy weather, the power generation amount of the solar cell 1 is less than the power consumption of the indoor load 4, and thus the commercial power system 5 Power supply is supplied to the indoor load 4 through the distribution board 3 to compensate for the power shortage.

  In the state where the power generation capacity of the solar cell 1 exceeds the standard due to the large amount of solar radiation, when the DC power generated by the solar cell 1 is converted and boosted to AC power by the power conditioner 2, the voltage specified value of the power conditioner 2 is It may exceed. In such a case, the voltage rise suppression function of the power conditioner 2 is activated, and AC power exceeding the voltage regulation value is supplied to the hot water supply device 6 via the power supply line 8 and also via the communication line 7. Then, the hot water supply device 6 is operated by inputting a signal to the hot water supply device 6. Thereby, since the hot water supply device 6 can be operated even in the daytime and the generated power of the solar cell 1 can be converted into thermal energy and stored, it can be effectively used and the conventional power generation loss can be eliminated. Further, when the hot water supply device 6 is operated using commercial power at midnight, commercial power can be saved.

  When the power generation capacity of the solar cell 1 changes to the standard state, the supply of AC power from the power conditioner 2 to the hot water supply device 6 is stopped and the operation of the hot water supply device 6 is stopped by inputting a signal to the hot water supply device 6. Let

  FIG. 2 is a flowchart showing operation control in the hot water supply system. In step S1, it is determined whether or not it is a time zone of nighttime power. If it is determined that it is not a time zone of nighttime power, the generated voltage is set in step S2. When the generated voltage is higher than the specified voltage value, the hot water supply device 6 is operated in step S3. When the generated voltage is lower than the specified voltage value, the hot water supply device 6 is stopped in step 6 and the step S1 is performed. Return to. Then, after operating the hot water supply device 6 in step S3, it is detected whether the hot water storage is completed in step S4. If the hot water storage is completed, the operation of the hot water supply device 6 is stopped in step S7. Returning to S1, if the hot water storage is not completed, the elapse of the predetermined time is detected in step S5, and if the predetermined time has elapsed, the process returns to step S1, and if the predetermined time has not elapsed, the process returns to step S3. The operation of the water heater 6 is continued. If it is determined in step S1 that it is a nighttime power time zone, it is detected in step S8 whether hot water storage is completed, and if hot water storage is completed, the process returns to step S1 to store hot water. If not completed, the hot water supply device 6 is operated in step S9 and the process returns to step S8.

  Such a hot water supply system is controlled by a control device (not shown), and accessories (not shown) such as sensors and timers related to the control device are installed at appropriate positions of the hot water supply device 6.

  In the above-described embodiment, power is supplied to the hot water supply device 6 via the power supply line 8. However, the hot water supply device is normally provided from the power conditioner 2 via the distribution board 3 without providing the power supply wire 8. 6 may be configured to supply power.

  The hot water supply system using solar power generation according to the present invention can be effectively used by being incorporated into various facilities such as ordinary homes, apartment houses, hospitals and elderly care centers.

It is a block diagram showing an embodiment of a hot water supply system using solar power generation according to the present invention. It is a flowchart which shows an example of the operation control in the hot water supply system using solar power generation concerning this invention. It is a block diagram which shows the conventional typical hot water supply system using photovoltaic power generation.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Solar cell 2 Power conditioner 3 Distribution board 4 Indoor load 5 Commercial power system 6 Hot-water supply apparatus 7 Communication line 8 Feed line

Claims (3)

  The power generated by the solar cell is supplied to the indoor load via the power conditioner and the distribution board, and surplus power is reversely flowed to the commercial power system side, and the power from the commercial power system is supplied to the distribution board. In a system for supplying power to an indoor load or hot water supply device through the solar battery, when the amount of power generated by the solar cell exceeds a specified voltage value of the power conditioner, the power conditioner of the power conditioner A hot water supply system using photovoltaic power generation, wherein the hot water supply device is supplied with electric power exceeding a specified voltage value and is operated in the daytime.   The power generated by the solar cell is supplied to the indoor load via the power conditioner and the distribution board, and surplus power is reversely flowed to the commercial power system side, and the power from the commercial power system is supplied to the distribution board. In a system for supplying power to an indoor load or a hot water supply device via a power supply line, comprising a power supply line for supplying electric power from the power conditioner to the hot water supply device, wherein the power generation amount of the solar cell is large, and the voltage regulation of the power conditioner When the value exceeds the value, the electric power exceeding the voltage condition value of the power conditioner among the generated electric power of the solar cell is supplied to the hot water supply device via the feeder line, and the hot water supply device is operated in the daytime. Hot water supply system using solar power generation.   The hot water supply apparatus is characterized in that a compressor, a gas cooler, a decompressor, and an evaporator are connected to each other in an annular shape, and water can be heated by a heat pump using carbon dioxide as a working medium. 2. A hot water supply system using solar power generation according to 2.

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