JP5124632B2 - Indoor ventilation system and method - Google Patents

Description

  The present invention relates to an indoor ventilation system and a ventilation method.

  In recent years, the Building Standards Law was revised in July 2003 as a countermeasure against sick house, which has been regarded as a problem, and the use of formaldehyde used for wooden construction materials such as plywood is restricted, and conventional wooden houses with low airtightness Except for, the installation of ventilation equipment was obligated, and the indoor concentration of chemical substances was restricted to below the allowable value. However, formaldehyde is not a ban on use, it is only a restriction on use, and other chemical substances are not regulated. Considering that these chemical substances are also used in furniture and the like, it is necessary to actively ventilate for 24 hours, but at the same time, the power consumed by the blower is also a problem. Although the power consumption of these ventilation fans is relatively small, they operate 24 hours a day, 365 days a year, so the power consumption is being reduced from the viewpoint of energy saving and the user's economic viewpoint.

In order to solve such a problem, a technique is known in which natural ventilation generated in a building is used to the maximum and effectively, and mechanical ventilation is used to compensate for the shortage of the set air volume (for example, Patent Document 1). reference).
In addition, a ventilation device for supplying air is provided in a plurality of rooms, and at least one exhaust ventilation device is provided in the entire house to form a ventilation path for ventilating the entire house, and the ventilation device is controlled by the ventilation device. There is known a control configuration in which a control device is provided and at least one of the exhaust ventilation devices is not operated when the supply ventilation device is in operation (see, for example, Patent Document 2).

JP 2005-16936 A JP 2005-61737 A

In the prior art, efforts have been made to reduce the total amount of power required for ventilation by reducing the power consumption of the device or stopping the device, but there was no idea of selecting the type of power. Electric power is usually generated using power generation means such as thermal power generation, hydroelectric power generation, nuclear power generation, etc., but the influence on the environment and the power generation cost differ depending on the composition ratio of the power generation method of the generated power. In addition, gas power generation, which has been spreading in recent years, may need to be operated at an inefficient output because there is no power consumption. If the time to generate power and the time to use it can be shifted, it is more efficient. Power can be used.
The present invention has been made in consideration of such circumstances, and provides an indoor ventilation system and method for an indoor ventilation fan that can actively utilize more environmentally friendly power and economically cheap power.

  The present invention includes an indoor ventilation device driven by DC power, a power storage device, an AC / DC converter that receives AC power from an external power supply system, converts the AC power into DC power, and outputs the AC power, and the AC / DC converter. An indoor ventilation system including a changeover switch that can be switched between a first operation mode for supplying the output of the power to the indoor ventilation device and the power storage device and a second operation mode for supplying the output of the power storage device to the indoor ventilation device is provided. In other words, the present invention is an indoor ventilation system that has a power storage device and is driven by direct current, and the first operation mode in which the ventilation device is driven by the power from the external power supply system and is simultaneously stored in the power storage device. An indoor ventilation system is provided that executes a second operation mode in which the indoor ventilation device is driven by the electric power stored in the electricity storage device.

With the above configuration, the indoor ventilation system can be operated by selecting the type of electric power. Here, the types of power include differences in the environmental load of the generated power, differences in power generation costs, differences in generated power generation facilities, differences in the unit price of power purchased by the user, and the like.
Specifically, there are differences in the amount of CO ₂ emissions between daytime generated power and late-night power, and differences in power purchase prices due to late-night power tariff settings.

  When you want to suppress the environmental load or when supplying power with a small environmental load, operate in the first operation mode mode. When supplying a large environmental load, stop the power supply and charge the power in the second operation mode. The device can be operated by When emphasizing economic merit, the operation is performed in the first operation mode during the time when the power price is low, and the operation is performed in the second operation mode during the time when the power price is high.

Furthermore, in the present invention, the indoor ventilation device may include a ventilation path and a ventilation fan for taking in air from the indoors and exhausting it to the outdoors, and the power storage device may be installed in the ventilation path. Furthermore, it is preferable that the ventilation path has an intake port and an exhaust port, and is arranged at a position where the intake port is lower than the exhaust port.
Further, it is preferable that the second operation mode is operated in the range of 0 to 50% of the discharge depth of the power storage device.

Here, examples of the power storage device include a secondary battery such as a lead storage battery and a nickel metal hydride battery, and an electric double layer capacitor.
Normally, the life of a power storage device is affected by the ambient temperature. By installing it in the ventilation path, the ambient temperature of the power storage device can be made equal to the living space, and the ambient temperature is controlled. Therefore, it is possible to provide a cheaper and more stable ventilation system.

  In particular, when a lead storage battery maintains a fully charged state, corrosion of the grid occurs, resulting in a decrease in current collection capacity. When left in a fully charged state, a lithium ion battery or the like reacts with the electrolytic solution and easily causes deterioration of the battery, such as formation of an insulator on the electrode. Since these are highly dependent on both the charging depth and the ambient temperature, when the ambient temperature is set within a specific range and charging and discharging are repeated at a shallow depth, the device is left in a normal fully charged storage state. Compared to this, the service life can be extended.

In addition, if the intake port in the ventilation path is positioned lower than the exhaust port, warm air naturally rises upward, so that such an arrangement makes it easier to release heat.
Furthermore, as a device to stabilize the temperature of the storage part of the power storage device, not only determine the position of the intake and exhaust ports, but also install a wind guide wall or control the ventilation flow path by arranging the power storage device Can be considered. In that case, it is necessary to devise so that the ventilation channel flows uniformly on the wall surface of the power storage device.

  The present invention relates to a solar cell system including a solar cell and a DC / AC converter that converts DC power into AC power and outputs the converted power to a household load and an external power supply system. And a second changeover switch capable of switching between a third operation mode supplied to the storage device and a fourth operation mode in which the output of the power storage device and the output of the solar cell are supplied to the DC / AC converter. Also good.

Instead of the solar cell system, other power generation facilities such as wind power generation, fuel cells, gas engines, and the like can be used. In the case of solar power generation or wind power generation of a power generation facility using natural energy whose output is unstable, it is possible to stabilize the output by connecting a power storage device, which is effective.
By adopting the configuration like this invention, in order to maintain the long-term cycle of the power storage device of the indoor ventilation system, the unused portion of the power storage device that is repeatedly charged and discharged at a shallow depth (for example, at a discharge depth of 30%) When operating an indoor ventilation system, 70% capacity is unused).

  Conversely, by using an emergency power storage device provided in another power generation facility together as a power storage device for an indoor ventilation system, it is possible to avoid leaving the storage battery fully charged as described above, and to shorten the service life. It can be lengthened.

  From another viewpoint, the present invention relates to an indoor ventilation device driven by DC power, a power storage device, an AC / DC converter that receives AC power from an external power supply system, converts the AC power into DC power, and outputs the AC power. / Ventilation method comprising the step of selectively executing a first operation mode for supplying the output of the DC converter to the indoor ventilation device and the power storage device and a second operation mode for supplying the output of the power storage device to the indoor ventilation device Is to provide.

  According to the present invention, economical operation is possible by executing the first operation mode in a time zone where the power rate is low and executing the second operation mode in a high time zone.

1 is a block diagram of an indoor ventilation system according to Embodiment 1 of the present invention. It is a time chart of the system described in FIG. FIG. 6 is a configuration diagram of Embodiment 2 of the present invention. It is a block diagram of the indoor ventilation system of Example 3 of this invention. FIG. 6 is a block diagram of an indoor ventilation system according to Embodiment 4 of the present invention.

Hereinafter, embodiments of the present invention will be described based on examples shown in the drawings.
Example 1
FIG. 1 is a block diagram showing an indoor ventilation system according to Embodiment 1 of the present invention. As shown in the figure, this indoor ventilation system includes an AC / DC converter 1, a changeover switch 2, a power storage system (power storage device) 3, and a ventilation system (ventilation device) 4. The outline specifications of each device are as follows.
AC / DC converter: AC100V input, DC24V output, output capacity 500W
Power storage system: Lead storage battery, 24V-80Ah
Ventilation system: DC24V input Power consumption 30W

The indoor ventilation system shown in FIG. 1 is switched between a first operation mode and a second operation mode by a timer (not shown). In the first operation mode, the changeover switch 2 is turned on, AC power from the external power supply system is converted to DC power by the AC / DC converter 1, and power (about 30 W) is supplied to the ventilation system 3, Charging the power storage system 3 (about 470 W) is performed. In the second operation mode, the changeover switch 2 is turned OFF, and power is supplied from the power storage system 4 to the ventilation system 3. The state transition diagram is shown in FIG.
In this indoor ventilation system, if the midnight power hours (from 23:00 to 7:00 in the next morning) where the midnight electricity rate is applied become the first operation mode and the other hours become the second operation mode, all day It is possible to operate 24 hours with low-cost late-night electricity, and to keep electricity costs low.

(Example 2)
In this embodiment, the configuration and specifications of each device are the same as those in Embodiment 1. However, as shown in FIG. 3, the ventilation system 3 includes a ventilation fan 3a and a ventilation path 3b, and the power storage system 4 is provided in the ventilation path 3b. It is stored.
By adopting such a configuration, it is possible to keep the ambient temperature in the temperature range equivalent to the living environment without particularly managing the temperature of the power storage system 4.
By installing the electricity storage system 4 installed under the floor in the ventilation path 3b of the ventilation fan 3a, the ambient temperature of the electricity storage system 4 should be within the range of ± 2 ° C of the temperature of the indoor temperature (the intake port of the ventilation fan 3a) It was confirmed.

(Example 3)
In this embodiment, as shown in FIG. 4, a photovoltaic power generation system 6 is added as a power generation facility to the system of the first embodiment. This system includes an AC / DC converter 1, a changeover switch 2, a second changeover switch 7, a ventilation system 3, a power storage system 4a, a booster circuit 10, a solar cell 11, and a DC / AC inverter 12. The general specifications of each are as follows.
AC / DC converter: AC100V input, DC24V output, output capacity 500W
Power storage system: Lead storage battery, 24V-160Ah
Ventilation system: DC24V input Power consumption 30W
Solar battery: 4.2kW
DC / AC inverter: 5kW

The system of FIG. 4 is a solar power generation system including a solar battery 11 and a DC / AC inverter 12 through a power storage system 4a via a booster circuit 10 in addition to the first operation mode and the second operation mode described in the first embodiment. Provides operation mode connected to system 6. The solar power generation system 6 converts the direct current power of the solar battery 11 into alternating current power by the inverter 12 and outputs the alternating current power (AC output), and supplies it to the household load and the external power supply system.
In this embodiment, the ventilation system 3 and the photovoltaic power generation system 6 are connected with the second changeover switch 7 opened in a normal state (when power can be received from an external power system via the AC / DC converter 1). The electric power stored in the power storage system 4a is not supplied to the indoor load or the external power system because each of them operates independently.
During normal times, the power supply to the ventilation system 3 is the first operation mode during the midnight power hours (from 23:00 to 7:00 the next morning) when the late-night electricity charge is applied, and the second operation mode during other times Set to be. Such a setting makes it possible to operate 24 hours a day with cheap midnight electricity all day long, and it is possible to keep electricity costs low.

On the other hand, in the event of an emergency (when a power failure occurs in the external power supply system), the second changeover switch 7 is turned on so that power can be supplied to the indoor load using the power generated by the photovoltaic power generation and power storage system 4a. Be controlled. That is, the output of the photovoltaic power generation system 6 can be stabilized by using the power storage system 4a that is normally used only for the ventilation system 3 as an auxiliary power source for the photovoltaic power generation system 6 temporarily in an emergency.
Furthermore, in the configuration of this embodiment, the initial capacity of the power storage system 4a is 3.8 kWh, and the ventilation system 3 is driven by the power of the battery outside the midnight power hours, so the battery is operated at a discharge depth of about 12%. .

In the usage method of this embodiment, a storage system for the ventilation system 3 and a storage system for photovoltaic power generation are separately prepared, and the storage system for the ventilation system 3 is charged / discharged at a deep charge / discharge depth. Compared with the case where the power storage system is always installed in a charged state, the battery life can be extended.
This is because it is always used at a shallow depth of discharge under certain conditions to prevent the active material from falling off or being deactivated when the storage battery is used repeatedly at a deep depth of discharge, and at the same time held in a charged state. This means that it is possible to alleviate the deterioration of the current collector grid that is continuously corroded.

Example 4
In this embodiment, as shown in FIG. 5, a lithium ion battery (average voltage 44.4V / 50.4V to 36V, 84Ah / 3.7kWh) is used as a power storage system 4b, a voltage monitoring device 18 is added, and a ventilation system The configuration is the same as in Example 3 except that 3a is 48V compatible. The system operates as in the third embodiment. In this case, the power storage system 4b is operated at a discharge depth of about 13%.

  In addition, the power storage system 4b using a lithium ion battery has been found from another study that the voltage at 13% discharge when the storage capacity is reduced to 60% is 45.5 V, and the voltage monitoring device 18 It has a function to detect the direction of the battery and the battery voltage, and it is set so that the lamp that needs to be inspected is turned on when the number of times that the storage battery voltage has passed 45.5V due to discharge becomes 5 times. With this configuration, it is possible to monitor capacity deterioration of the power storage system for the following reason.

  Normally, when a battery is discharged under a certain condition (load), the voltage gradually decreases from the higher one. If there is no deterioration of the battery, when a constant amount of electricity (constant load × constant time) is discharged after full charge, the voltage at which the battery discharge ends is constant even if the cycle is repeated. However, in practice, since the battery gradually deteriorates, even when a certain amount of electricity is discharged, the voltage at which the discharge ends gradually decreases as the cycle is repeated. Therefore, if it is monitored there, it becomes possible to recognize the deterioration of the battery.

  More specifically, in this example, if the battery is not deteriorated, the discharge ends at about 48 V when 13% of the discharge is performed. The voltage gradually decreases as the battery deteriorates, and when the capacity decreases to 60%, discharging 13% of the amount of power (of the initial capacity of the battery) decreases to 45.5V, so there is no further deterioration. As the process proceeds, the voltage at the end of the discharge will be 45.5V or less. This state is expressed as having passed 45.5V by discharge. In addition, since the battery will not deteriorate again, if the battery is fully charged again, and if the amount of power equivalent to 13% (of the initial capacity of the battery) is discharged, it will again pass 45.5V (by discharge), Discharging ends at a voltage of 45.5V or less. Therefore, this number of times is counted so that a signal for inspection is required.

  Even if the battery has passed once, the determination is possible, but even if the battery is not deteriorated, if a sudden load (for example, an inrush current when the fan starts rotating) is applied, a voltage drop may occur temporarily. . If the voltage falls below the voltage set at that time, simply monitoring the voltage will cause a signal to be inspected (malfunction) even if the battery has not deteriorated, so avoid it. Therefore, it is set to 5 times continuously in normal repeated charge / discharge. Increasing the number of times decreases the probability of malfunction.

In addition, three lithium-ion battery samples used in power storage system 4b were placed in a constant temperature bath at 60 ° C, one was left fully charged, one was charged and discharged at a discharge depth of 10%, and the other was 100. When the battery was left fully charged and the sample was repeatedly charged and discharged at 100%, the capacity deteriorated to 50% in 2 weeks, but the discharge depth was 10% (single charge / discharge / day ) And 50% of the samples that repeated the charge / discharge cycle, capacity degradation occurred after one month.
From these facts, it can be seen that the battery life of the lithium ion battery is longer when it is repeatedly subjected to relatively shallow charging / discharging than when it is left fully charged.

  According to the present invention, an indoor ventilation system that operates for 24 hours can be operated only with midnight power at a low power price, so that it is possible to reduce electricity costs. In addition, if the power storage device is installed in the ventilation path, the ambient temperature environment of the power storage device can be adjusted to near room temperature without particularly controlling the temperature, so that the life of the power storage device can be extended.

  By combining this indoor ventilation system with a power generation system such as solar power generation and setting the capacity of the power storage device and the power capacity consumed by the ventilation device to a predetermined capacity, it is possible to further extend the life of the power storage device. In an emergency, the output of the photovoltaic power generation system can be stabilized. In that case, since it becomes possible to operate the indoor ventilation system every day with a constant load and monitor the behavior of the power storage system according to the operation status, compared with the case where a separate power storage device is prepared for the solar power generation system, It becomes easy to grasp the state of the power storage device, and finally, it is possible to reduce work such as periodic inspection.

1 AC / DC converter 2 Changeover switch 3 Ventilation system 4 Power storage system

Claims (8)

An indoor ventilation device driven by DC power, a power storage device comprising a lithium ion battery , an AC / DC converter that receives AC power from an external power supply system and converts it into DC power, and the AC / DC conversion A changeover switch that can be switched between a first operation mode in which the output of the machine is supplied to the indoor ventilation device and the power storage device and a second operation mode in which the output of the power storage device is supplied to the indoor ventilation device, and the power storage device is constant from full charge The voltage monitoring device monitors the voltage of the power storage device when the amount of electricity is discharged, and the voltage monitoring device outputs a signal requiring inspection when the voltage of the power storage device falls below a predetermined voltage at least twice. indoor ventilation system that.   Each operation mode is switched according to the time zone of the day, the first operation mode is executed in the midnight time zone when the midnight power charge is applied, and the second operation mode is executed in the time zone other than the midnight time zone. The indoor ventilation system according to claim 1.   The indoor ventilation system according to claim 1, wherein the indoor ventilation system includes a ventilation path and a ventilation fan for taking in air from the indoors and exhausting the outdoors, and the power storage device is installed in the ventilation path.   A solar cell system including a solar cell and a DC / AC converter that converts DC power into AC power and outputs it to a household load and an external power supply system, and an output of only the solar cell is supplied to the DC / AC transformer. 2. A second changeover switch capable of switching between a third operation mode and a fourth operation mode in which the output of the power storage device and the output of the solar cell are supplied to the DC / AC converter. Indoor ventilation system. An indoor ventilation device driven by DC power, a power storage device comprising a lithium ion battery , an AC / DC converter that receives AC power from an external power supply system and converts it into DC power, and voltage monitoring of the power storage device A first operation mode in which the output of the AC / DC converter is supplied to the indoor ventilation device and the power storage device, and a second operation mode in which the output of the power storage device is supplied to the indoor ventilation device. In addition , the voltage of the power storage device is monitored by the voltage monitoring device when the power storage device discharges a certain amount of electricity from full charge, and if the voltage of the power storage device falls below the predetermined voltage two or more times, a signal requiring inspection is required. indoor ventilation how to, characterized in that issue.   Each operation mode is switched according to the time zone of the day, and the first exercise mode is executed in the midnight time zone where the midnight power charge is applied, and the second exercise mode is executed in a time zone other than the midnight time zone. The indoor ventilation method according to claim 5.   6. The indoor ventilation method according to claim 5, wherein the indoor ventilation device includes a ventilation path and a ventilation fan for taking in air from the inside and exhausting it to the outside, and the power storage device is installed in the ventilation path.   A solar cell and a solar cell system further comprising a DC / AC converter for converting DC power to AC power and outputting to a home load and an external power supply system are provided, and the output of only the solar cell is supplied to the DC / AC transformer. The indoor ventilation according to claim 5, further comprising a step of selectively executing a third operation mode to be supplied and a fourth operation mode to supply the output of the power storage device to the DC / AC converter via the booster. Method.

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