JPH1014255A - Thermoelectric compound system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make effective use of power and attain a large energy-saving effect by incorporating a semiconductor thermal cell, utilizing a thermoelectric effect in an inverter device, storing electric energy as the thermal energy in the semiconductor thermal cell in supplying power to a load, and changing it into electric energy again for power supply to the load when thermal energy higher than a fixed amount is stored. SOLUTION: A semiconductor thermal cell module 3, consisting of a plurality of thermoelectric element, is connected in series between the inverter 5 and the rectifier 4 of an inverter device 6. When the temperature of a hot part or an endothermic part of the thermal cell module 3 has reached a prescribed value, or the setting time of a timer has reached a prescribed value, AC input from a commercial power source 1 is turned off or on, and the output from the thermal cell module 3 is inputted into the inverter 5 of the inverter device 6. In a system which changes the output of a DC power source (for example, a solar battery) into an AC by the inverter for power supply to a load, a semiconductor thermal cell module is connected in series between a DC power source and an inverter. When the output of the DC power source is a prescribed value or less, the output of the DC power source is cutoff, and the output of the thermal cell module is inputted into the inverter for supplying power to the load.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention incorporates a semiconductor thermal battery having a function of converting and storing electric energy into thermal energy by utilizing a thermoelectric effect in an inverter device, thereby effectively saving power. The present invention relates to a thermoelectric combined system that is used for:

[0002]

2. Description of the Related Art More than 80% of energy depends on imports,
Japan's energy demand structure is more vulnerable than other major developed nations, with the dependence on oil in primary energy supply being about 60%. In addition, the energy demand in the world is expected to increase further in the future, especially in the Asian region, where energy demand is expected to increase sharply due to rapid economic growth and still low energy consumption efficiency. Is expected. Energy is a basic commodity that supports the economic society, and a stable and efficient supply of energy is indispensable for the sustainable development of the economy.

In recent years, global warming due to an increase in carbon dioxide (CO ₂ ) emission, and global environmental problems such as acid rain due to nitrogen oxides (NOx) and sulfur oxides (SOx) have been addressed.
Global efforts are underway. These are emitted with the burning of fossil fuels, and energy and environmental issues are closely inseparable. Japan, which is one of the world's leading energy consumers and has a pivotal position in the international community, is seeking active and responsible action from inside and outside Japan.

[0004] Under such circumstances, also in order to achieve an accurate response to the same problem as Japan, in the prevention of global warming action plan (90 year development), the per capita CO ₂ emissions 2
We have been working to achieve the goal of maintaining the level at 90 years since 2000, but we have achieved efforts to achieve these goals by reducing fossil fuel consumption while achieving stable economic growth. It is essential to go.

On the other hand, electric power, which accounts for about 40% of Japan's energy supply, is helped by its unique convenience, and the overall energy
The demand is expected to grow at a rate of 2.9% per year until 2004, which is the premise of the power facility plan in 1996. Furthermore, in FY2010, the amount of generated power was 1,133 billion Kwh (1.
5 times).

An effective means for solving the above-mentioned problems promotes the effective use of energy and the introduction of "new energy" which saves little in resource supply and has a small burden on the environment. It will be.

[0007] New energy includes "natural energy" such as the sun and wind, "recycling energy" such as incineration waste heat and sewage heat, and "high efficiency energy" such as cogeneration and fuel cells. And is extremely effective in reducing dependence on petroleum and suppressing CO ₂ emissions.

Further, from the viewpoint of effective use of energy, development of inexpensive devices and elements having a function of storing energy, for example, converting electric energy into heat energy and storing it, or using waste heat If the energy can be stored as heat energy and the stored heat energy can be taken out as electrical energy when needed, it is a very effective solution to the above-mentioned problem.

[0009] By the way, as equipment for storing electric energy and taking it out again as necessary when necessary,
There are secondary batteries (chemical batteries), flywheels, superconducting storage devices, and the like, but the most common and widespread are secondary batteries as rechargeable batteries. Speaking of secondary batteries, lead-acid batteries for automobiles used to be the mainstay, but nickel cadmium (NiCad) has recently been used mainly for portable devices such as mobile phones, PHS (simplified mobile phones), notebook computers, and video cameras. Demand for batteries, nickel-metal hydride batteries, and lithium-ion batteries is increasing rapidly. However, lead-acid batteries are still the mainstream for electric power, and the principle of energy storage of these secondary batteries is based on an electrochemical reaction involving the transfer of ions. Therefore, the presence of an electrolyte as an ion conductor is an essential condition for this energy storage.

On the other hand, a flywheel stores electrical energy as mechanical energy of a rotating body, and converts mechanical energy of the rotating body into electrical energy when necessary. As a flywheel battery using this flywheel, a route bus having a giant flywheel made of steel of about 1.5 tons or more has been put to practical use in Switzerland in the 1950s as a flywheel battery. Small-sized batteries that have the potential to replace batteries were announced in the 1990s, when carbon fiber reinforced plastics, which were lighter and stronger, were popularized and high-speed rotating flywheels were realized. It is. The flywheel battery, announced in 1993 by the American venture company American Flywheel Systems (AFS), is a carbon fiber reinforced plastic container kept under vacuum to avoid friction with air. It contains two flywheels that rotate in opposite directions to cancel the gyro effect. Use a non-contact magnetic bearing to avoid friction in the bearing part,
Each of the carbon fiber reinforced plastic flywheels has a permanent magnet embedded therein, and has a structure in which electric power is generated by generating electric power using a pickup coil and a rotating magnet attached to the end of the housing.

The flywheel battery is approximately 500 to 100
Unlike conventional lead-acid batteries, which have a long service life with zero charge / discharge, they not only endure thousands of repetitions but also have three times more energy density and do not emit hazardous waste like chemical batteries. And problems to be solved such as practical reliability and cost.

The superconducting storage device cools a conductor to a superconducting state below a critical temperature at which its electric resistance becomes zero, thereby reducing heat loss due to electric current to zero and storing electric energy in the form of electric current. However, it is expensive, such as requiring a cooling device, along with many technical issues before practical use.

Meanwhile, the technology utilizing the thermoelectric effect is one of the well-known chemical devices having a simple structure and is based on the Seebeck effect, which is the same phenomenon as the operation of a thermocouple. I have. Thermocouples are widely used in temperature measurement and control devices because of their simple structure, low cost, and high reliability. However, at present, there are few practical examples other than radioisotope heat generators (RTGs) for electric power.

The thermoelectric power generation system has features that it is easy to maintain because there is no drive unit, and that the equipment can be small. Then, power can be generated using waste heat. Current,
There are approximately 1840 municipal landfills nationwide.
Among them, there are about 1400 boiler-type power plants that cannot be used, and the Science and Technology Agency has started a system technology to convert these unused waste heat directly into energy for effective use since 1995. Embarked on the development of
We are planning to start a demonstration test in fiscal year 0.

[0015]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and has a function of converting and storing electric energy into heat energy by utilizing a thermoelectric effect. Into the inverter device,
It is an object of the present invention to provide a simple and inexpensive thermoelectric combined system that can effectively use electric power without waste and greatly increase the energy saving effect.

[0016]

In order to solve the above-mentioned problems, a thermoelectric combined system comprises a forward converter for converting alternating current of a commercial power supply into direct current, and an output of the forward converter is converted to an alternating current of the commercial power by an inverse converter. A thermal battery module having an inverter device for converting the voltage and frequency into the same voltage and supplying the same to a load, and comprising a plurality of semiconductor thermal batteries (for example, thermoelectric elements composed of P-type and N-type semiconductors), Connected in series between the converter and the inverter, when the temperature of the heat generating portion or the heat absorbing portion of the thermal battery module reaches a predetermined value, or the time specified by the timer reaches the predetermined value. Then, the AC input from the commercial power supply is turned off or on, and the output from the thermal battery module is polarity-converted and connected to the inverter. Alternatively, a DC power generator (for example, a solar cell) having an inverter device for converting the DC power to the same voltage and frequency as the AC of the commercial power supply by an inverter and supplying the same to a load, and generating the DC power A thermal battery module comprising a plurality of semiconductor thermal batteries is connected in series between the inverter and the inverter, and when the output of the DC power generator falls below a predetermined value, the output of the DC power generator And the output from the thermal battery module is polarity-converted and connected to the inverter.

[0017]

According to the present invention, a semiconductor thermal battery utilizing the thermoelectric effect is incorporated in an inverter device, and when power is supplied to a load, electric energy is stored as heat energy in the semiconductor thermal battery, When the energy is stored over a certain amount, it is converted into electric energy again and supplied to the load. Therefore, the configuration of the device is simple and easy, and the electric power can be effectively used. Is obtained.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment according to the present invention will be described below with reference to FIGS.
A description will be given based on FIGS. 3, 4 and 5.

The semiconductor thermal battery which is a core element of the present invention comprises:
This utilizes the thermoelectric effect phenomenon of a thermoelectric element made of P-type and N-type semiconductors, which will be described first with reference to FIGS.

FIG. 5 is an explanatory diagram of the thermoelectric effect by the thermoelectric element. When one end of the junction (junction metal) between the P-type semiconductor 22 and the N-type semiconductor 23 is heated (the other end is not heated), an electromotive force is generated, and a current as indicated by an arrow flows through the external circuit. Such a phenomenon is called the Seebeck effect.

Conversely, the P-type semiconductor 22 to the N-type semiconductor 23
When a current flows toward the junction, the junction (the heating unit in FIG. 5) generates heat, generating heat and increasing the temperature. Such a phenomenon is called a Peltier effect, which is just the opposite of the Seebeck effect, and both are known as a thermoelectric effect.

FIG. 4 shows an example of a semiconductor thermal battery. Reference numeral 21 denotes a thermoelectric element composed of a P-type semiconductor 22 and an N-type semiconductor 23. Leader terminals 24 and 25 are joined to the P-type semiconductor 22 and the N-type semiconductor 23 on the low temperature side by brazing or the like.

The high temperature side of the thermoelectric element 21 is
Are joined to the thermoelectric element 21 by joining conductors 27 and 28 fitted to the thermoelectric element 21. This joining method may be, for example, a brazing method, or a male screw for the joining material body 26, a female screw for each of the joining conductors 27 and 28, and fixing to the thermoelectric element 21 with a screw. Here, as the bonding material 26, a material having a large heat capacity, for example, beryllium, aluminum, or an alloy thereof having a large specific heat is desirable. Incidentally, the specific heats of beryllium and aluminum at 500 ° C. are 0.67 cal / g ° C. and 0.27 cal / g ° C., respectively, and that of copper is 0.1 cal / g ° C.
Has a larger specific heat capacity than

Reference numeral 29 denotes a heat insulator, which is preferably made of a material having a low heat conductivity and a large specific heat. For example, ceramic fibers and alumina fibers can be used as inorganic fiber heat insulators for ultra-high temperatures. Here, the semiconductor thermal battery of FIG.
Although the heat insulator 29 is provided, the heat insulator 29 may be omitted, or only the heat insulator 29 may be used without using the joining material body 26 and the joining conductors 27 and 28.

Next, the operation of the semiconductor thermal battery of FIG. 4 will be described.

When power is supplied to the thermoelectric element 21 now,
When a positive voltage is applied to the extraction terminal 24 of the P-type semiconductor 22 and a current is applied to the extraction terminal 25 of the N-type semiconductor 23 as a negative voltage,
The PN junction of the thermoelectric element 21 fixed by the bonding material body 26 and the bonding conductors 27 and 28 generates heat as described with reference to FIG. Once this part is heated, heat loss is suppressed by the heat retaining effect of the heat insulator 29, and thermal energy is stored.

Here, when power is no longer supplied to the thermoelectric element 21, the heat energy of the heating section is reduced as described with reference to FIG.
Is converted into electric energy, the lead-out terminal 24 of the P-type semiconductor 22 has a positive voltage, and the lead-out terminal 25 of the N-type semiconductor 23 has
Becomes a negative voltage, and a current flows to an external load (not shown) to supply electric power.

The above is a case where electric energy is converted into heat energy and stored, and when necessary, the stored heat energy is converted again into electric energy and electric power is supplied to a load. May be generated to supply power to the load. In this case, the electric energy is continuously supplied to the external load while the heating state of the heating unit continues.

An embodiment of the thermoelectric combined system using the semiconductor thermal battery will be described below with reference to FIGS. 1, 2 and 3.

FIG. 1 is a schematic diagram of a thermoelectric combined system device. Reference numeral 1 denotes a commercial power supply (system) supplied from a power company. In the case of a private house, the voltage is 100/110 V and the frequency is 50/60 Hz. Reference numeral 2 denotes a load connected to electric appliances in the house. Thermal battery module 3
A plurality of the semiconductor thermal cells shown in FIG. 4 are connected in series and in parallel, and are connected in series between the forward converter 4 and the reverse converter 5. Reference numeral 6 denotes a so-called inverter device comprising a forward converter 4 and an inverse converter 5, and this inverter device 6 includes a rectifying capacitor and a reactor (not shown).

Reference numerals 1a and 2a denote a-contacts (normally open contacts) of relays, and 1b, 2b and 3b denote b-contacts (normally closed contacts) of relays, using semiconductor switching elements such as transistors and SCRs. These functions may be realized.

Next, the operation of the combined thermoelectric system device of FIG. 1 will be described.

The AC power supplied from the commercial power supply (system) 1 is converted by the forward converter 4 into DC power,
Terminal 3 ｀ of the thermal battery module 3
｀ is input to the inverse converter 5. At this time, if the terminals 3 # and 3 # of the thermal battery module 3 are connected to the P-type semiconductor 22 and the N-type semiconductor 23 in FIG. 4, respectively, the PN junction of the semiconductor thermal battery generates heat. The temperature rises. In this state, the DC power is converted to the same voltage and frequency as the commercial power supply (system) 1 by the inverter 5 and the load 2
Supply AC power to

Now, when the temperature of the heat generating portion of the thermal battery module 3 reaches a predetermined value, or when the time specified by a timer (not shown) reaches the predetermined value, the relay operates. 1a and 2a are closed, and 1b, 2b and 3b are open, and the AC power from the commercial power supply (system) 1 is cut off. In this state, the heat energy of the heat generating portion stored in the thermal battery module 3 is converted (directly) into electric energy by the thermoelectric effect (Seebeck effect), and is supplied to the inverter 5 from the terminal 3 '. Power flows into the terminal 5 'of the forward converter 4 through the terminal 5' to form a closed loop returning from the terminal 4 'to the terminal 4' and further to the terminal 3 'of the thermal battery module 3. I do. That is, when the relay operates, the output from the thermal battery module 3 is converted in polarity from the terminal 3 ° to 3 ° and connected to the inverter 5, and the heat storage energy of the thermal battery module 3 is converted into AC power. And supplies power to the load 2. The power supply to the load 2 continues while the temperature of the heat generating portion of the thermal battery module 3 is maintained at a predetermined value or more.

When the temperature of the heat generating portion of the thermal battery module 3 is equal to or lower than a predetermined value or when the time set by the timer is reached,
The relay is operated, 1a and 2a are open, and 1b, 2
The circuits b and 3b are closed, return to the original state, and the electric power from the commercial power supply (system) 1 is supplied to the load 2. Such a phenomenon continues thereafter, and effective use of electric power, that is, a significant energy saving effect is realized.

FIG. 2 is a block diagram of a thermoelectric combined system with solar cells. Reference numeral 7 denotes a solar cell module which is composed of a plurality of solar cells connected in series and in parallel. The DC output of the solar cell module 7 is converted to AC by the inverter 5 through the thermal cell module 3, and power is supplied to the load 2 from the distribution board 8. Reference numeral 1 denotes a commercial power supply (system) connected to a distribution board 8, which supplies power for the solar battery and the thermoelectric combined system.

The operation of the thermoelectric combined system combined with solar cells of FIG. 2 is the same as that of the combined thermoelectric system device of FIG. That is, when the output of the solar cell module 7 is equal to or higher than a predetermined value, electric power is accumulated as thermal energy by the heat generated by the PN junction of the semiconductor thermal battery constituting the thermal cell module, and the power is stored in the load 2. When power is supplied and the output of the solar cell module 7 becomes equal to or less than a predetermined value, the output of the solar cell module 7 is shut off, and the electric power is supplied to the load 2 by the heat storage energy of the thermal cell module 3. I am trying to supply.

FIG. 3 is an image diagram of the photovoltaic power generation system. FIG. 3 shows a residential photovoltaic power generation system in which a gantry 15 is mounted on the roof of a house 20 and a solar cell module 7 is installed on the gantry 15.
Connect with a terminal board (not shown) in. The DC power generated by the solar cell is passed through the DC side switch 12 and the inverter 5
To convert to AC.

The protection device 10 includes an overvoltage relay (OVR),
Undervoltage relay (UVR), frequency reduction relay (UF
R), reverse power relay (RPR), underpowered relay (UP
R) Ground fault overvoltage relay (OVGR). The AC power converted by the inverter 5 is supplied to the protection device 1.
0 through the generated electricity meter 9 to the house 20 from the distribution board 8
It is supplied to a load 2 such as an electric light, an air conditioner, and a television.

If the electric power generated by the solar cell module 7 is equal to or larger than the electric power supplied to the load 2, the surplus electric power is counted by the electric power meter 14a via the AC switch 13; A reverse power flow system is connected to the commercial power supply (system) 1. Here, the count value of the power selling watt-hour meter 14a is the surplus power purchased by the power company.

When the power generated from the solar cell module 7 decreases, power is supplied from the commercial power supply (system) 1 from the power company.
The power consumption is counted by b.

An example in which the thermoelectric combined system of the present invention is incorporated in the conventional solar power generation system described here is the combined solar cell combined thermoelectric system shown in FIG.
Also in this case, a significant energy saving effect can be obtained as in the case of FIG.

【The invention's effect】

According to the present invention, a semiconductor thermal battery utilizing the thermoelectric effect is incorporated in an inverter device to make effective use of electric power, and there is an effect that significant energy saving can be achieved with a simple device configuration.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of a thermoelectric combined system device.

FIG. 2 is a block diagram of a combined thermoelectric system with solar cells.

FIG. 3 is an image diagram of a solar power generation system.

FIG. 4 is a diagram showing an example of a semiconductor thermal battery.

FIG. 5 is an explanatory diagram of a thermoelectric effect by a thermoelectric element.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Commercial power supply (system) 2 Load 3 Thermal battery module 4 Forward converter 5 Inverter 6 Inverter device 7 Solar cell module 8 Distribution board 9 Generated electricity meter 10 Protective device 11 Connection box 12 DC Side switch 13 AC side switch 14a, 14b Watt hour meter 15 Mount 20 House 21 Thermoelectric element 22 P-type semiconductor 23 N-type semiconductor 24, 25 Lead-out terminal 26 Joint material body 27, 28 Joint conductor 29 Insulator

Claims (5)

[Claims] A forward converter for converting alternating current of a commercial power supply to direct current, and an inverter for converting the output of the forward converter to the same voltage and frequency as the alternating current of the commercial power supply by an inverse converter and supplying the same to a load. A thermal battery module comprising a plurality of semiconductor thermal batteries, connected in series between the forward converter and the inverter, and providing a heat generating portion or a heat absorbing portion of the thermal battery module. When the temperature reaches a predetermined value, the AC input from the commercial power supply is turned off or on, and the output from the thermal battery module is polarity-converted and connected to the inverter. And thermoelectric combined system. 2. A forward converter for converting alternating current of a commercial power supply to direct current, and an inverter for converting an output of the forward converter to the same voltage and frequency as the alternating current of the commercial power supply by an inverse converter and supplying the same to a load. A thermal battery module comprising a plurality of semiconductor thermal batteries is connected in series between the forward converter and the inverse converter, and a time indicated by a timer reaches a predetermined value. In the thermoelectric combined system, the AC input from the commercial power supply is turned off or on, and the output from the thermal battery module is polarity-converted and connected to the inverter. 3. A forward converter for converting an alternating current of a commercial power supply to a direct current, and an inverter for converting the output of the forward converter to the same voltage and frequency as the alternating current of the commercial power by an inverse converter and supplying the same to a load. A DC power generator for converting the DC power to the same voltage and frequency as the AC of the commercial power by an inverter and supplying the same to a load, and generating the DC power; A thermal battery module comprising a plurality of semiconductor thermal batteries is connected in series between the inverter and the inverter, and when the output of the DC power generator falls below a predetermined value, the output of the DC power generator is shut off. A thermoelectric module, wherein the output from the thermal battery module is polarity-converted and connected to the inverter. 4. The thermoelectric composite system according to claim 1, wherein the semiconductor thermoelectric battery is a thermoelectric element made of a P-type and an N-type semiconductor. 5. The combined thermoelectric system according to claim 3, wherein the DC power generator is a solar cell.