JPH09191586A - Power conversion storage method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power conversion storage method by which surplus electric power related to the waste of energy can be effectively utilized and which is safe and easy to handle. SOLUTION: In the process of liquefying air, when there is surplus electric power, the compressor of an air liquefying device 1 is driven by using the surplus electric power to compress raw-material air. The air is cooled by a cooler 13 and the air is cooled by low-temperature air sent from a receiving tank 16 in a heat exchanger 14 and after that, the temperature of the air is dropped by adiabatic expansion caused by an expansion valve and the air becomes liquid air L and is stored into the receiving tank 16. In the process of storing liquid air, the liquid air L is stored into a storage tank 2. In the process of vaporizing liquid air, the liquid air L of the storage tank 2 is heated by a vaporizer 3 to make a high pressure. In the process of driving a generator device, the high-pressure air from the vaporizer 3 is injected into steam, and the output of a turbine 23 is increased, so that the generated energy of a generator 25 is increased by the increment of the output.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power conversion and storage method for converting electric power into another energy form, storing the electric power, and returning the electric power to the electric power for use when necessary.

[0002]

2. Description of the Related Art Generally, the power consumption on the consumer side (hereinafter referred to as power load) fluctuates seasonally or day and night.
In particular, the cooler has a high operating rate during the daytime in summer, and the electric load has reached its peak. The maximum power generation capacity of the power plant is set in consideration of the power load at this peak.

[0003]

However, all of the maximum power generation capacity is not utilized except during peak times in summer, resulting in excess power generation capacity that is not used for most of the year. The fact is that such surplus power generation capacity is not effectively utilized. On the other hand, in thermal power plants and nuclear power plants, boiler facilities and power generation facilities have minimum capacities for continuing operation. Therefore, for example, even when the electric power load is below the above-mentioned minimum capacity, operation cannot be performed below the minimum capacity, and useless operation cannot be avoided. Furthermore, when it is predicted that the power load at the peak of summer will exceed the maximum power generation capacity, it was necessary to upgrade new power generation facilities in advance.

On the other hand, in pumped storage power generation, even if water is stored in a dam, if the river rises, it is necessary to discharge the stored water at the right angle. However, when the power load at that time was small, the dam water had to be discharged as it was without using it for power generation, leading to a waste of energy.

The present invention has been made in view of the above-mentioned conventional problems, and provides a power conversion and storage method capable of effectively utilizing surplus power leading to waste of energy and being safe and easy to handle. The purpose is.

[0006]

In order to achieve the above object, a power conversion and storage method according to the present invention uses an excess power to liquefy air to store the liquid air and, if necessary, the liquid. The high-pressure air obtained by vaporizing the air drives the turbine of the power generator to generate electric power.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the method of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic configuration diagram showing an air liquefier, a storage tank, a vaporizer, and a power generator used in the present invention. In the figure, an air liquefaction device 1 is a model of a known Linde type device, and includes a compressor 11 for compressing raw material air, a motor 12 for driving the compressor 11,
Cooler 13 for cooling compressed raw material air, cooler 13
A heat exchanger 14 for further cooling the raw material air from the, an expansion valve 15 for liquefying the raw material air by adiabatic expansion, a receiving tank 16 for temporarily storing the liquefied liquid air L, and an opening / closing for opening and closing the receiving tank 16 freely. A valve 17 is provided.

The storage tank 2 is a high-pressure sealed container that stores the liquid air L, and is connected to the on-off valve 17 by piping. The vaporizer 3 is arranged between the on-off valve 20 and the power generation device 4, and heats the liquid air L from the storage tank 2 to a high pressure by utilizing the residual heat of the boiler of a thermal power plant or a nuclear power plant, for example. To do. The power generator 4 mainly includes a turbine 23 driven by high-pressure steam of a power station boiler, and a generator 25 that generates power by driving the turbine 23.

The turbine 23 is equipped with a supply air control valve 26 for adjusting the flow rate of high-pressure steam from the power plant boiler, an air-injection control valve 22 for adjusting the injection amount of high-pressure air, and a rotor 24 having moving blades. The rotor 24 is connected coaxially with the drive shaft of the generator 25. An injection control valve 22 is connected to the high pressure steam inlet side pipe of the turbine 23. Further, although a single-stage rotor is shown in FIG. 1 for the sake of clarity, it is preferable to use a multi-stage rotor in practical use.

Next, the power conversion and storage method according to this embodiment will be described with reference to FIGS. 1 and 2. Air Liquefaction Step A First, the raw material air has been previously removed of water, carbon dioxide gas and the like with solid sodium hydroxide or the like. Therefore, if the power load is smaller than the maximum power generation capacity, that is, if there is surplus power, the motor 12 of the air liquefaction device 1 is started using this surplus power to drive the compressor 11. Thereby, the raw material air is compressed to, for example, about 50 atm. The compressed and heated air is cooled in the cooler 13 by heat exchange with, for example, cooling water. Further, the air from the cooler 13 is guided to the heat exchanger 14, is cooled to about −160 ° C. by heat exchange with the low temperature air from the receiving tank 16, and is then guided to the expansion valve 15. When passing through the expansion valve 15, the air undergoes a temperature drop due to adiabatic expansion (Joule-Thomson effect) to become liquid air L (boiling point = -194.3 ° C. (1 atmospheric pressure conversion)) and is stored in the receiving tank 16. .

Liquid Air Storing Step B Next, the liquid air L liquefied by the air liquefying apparatus 1 is transferred from the receiving tank 16 and stored in the storage tank 2.

Then, when the power load is close to the maximum power generation capacity and the supplementary power is required, the following steps are executed. Liquid air vaporization step C First, the opening / closing valve 20 of the storage tank 2 is opened, and the liquid air L is guided to the vaporizer 3. The liquid air L is heated by the vaporizer 3 to have a high pressure.

Power Generation Device Driving Step D Then, an appropriate amount of the high pressure air obtained by the vaporizer 3 is introduced into the steam pipe on the inlet side of the turbine 23 and injected into the steam by adjusting the opening degree of the air injection adjusting valve 22. . As a result, the output of the turbine 23 is increased, and the increased output is generated by the generator 25.
The power generation amount of can be increased. The power thus increased is used as supplementary power.

Incidentally, as shown in FIG. 3, it is shown by a solid line.
The surplus power is supplied to the daily power load curve M when the load is low at midnight.
Part of power (broken line N in the figure₁Diagonal line surrounded by and curve M
Part n ₁Is used to produce and store liquid air.
During peak load during the day, power is generated using liquid air,
This is the supplementary electric energy (broken line N in the figure_TwoSurrounded by and the curve M
The shaded part n_TwoEquivalent to). This allows
The amount of power supplied from the power plant during peak load is small
Both broken lines N_TwoThe power level indicated in
The salary can be leveled. However, the stored liquid
Air must always be used on or near the day of arrival
It is not something that doesn't exist, for example, what is manufactured in spring is used in summer.
It can be used for different seasons or
It is also possible to plan the leveling of the electric power supply in a year.
You.

Incidentally, in utilizing the stored liquid air, an embodiment in which high-pressure air is injected into the steam at the steam turbine inlet side of the power plant has been shown. For example, a turbine dedicated to the liquid air is provided, and the carburetor 3 is used. Alternatively, the dedicated turbine may be driven only by the high pressure air to generate electric power.

The bearings of the turbine 23 and the generator 25 are cooled in order to reduce malfunctions and extend their life. However, a part of the liquid air L stored in the storage tank 2 may be used for cooling. it can. For example, a part of the liquid air L is guided to the vicinity of the bearing part to cool the bearing part, and the liquid air L is vaporized by the heat received at that time and then returned to the outlet side of the carburetor 3.

Further, as the compressed air cooling medium used in the cooler 13, for example, a part of the liquid air L in the storage tank 2 can be used instead of the cooling water shown in the above embodiment. That is, part of the liquid air L is cooled by the cooler 1.
It suffices that the compressed air is cooled by passing it through the air passage 3, and the liquid air L is vaporized by the heat received at that time and returned to the outlet side of the vaporizer 3. As a result, it is possible to improve the energy utilization efficiency of the entire system and reduce the required capacity of the air liquefaction device.

Further, the air liquefaction device in the present invention is not limited to the Linde type device described above, but it is also possible to use, for example, a Claude type device having an expansion turbine or another type of device.

[0019]

As described above, according to the power conversion and storage method of the present invention, excess power is used to liquefy and store air, and supplementary power is required as in the case of peak load. Since the electric power is generated using liquid air, the surplus electric power can be effectively used, and the electric power supply amount can be leveled. It is also possible to reduce the number of new peak power plants in summer and the power generation capacity of new power plants.

Moreover, for example, when ammonia, hydrogen, etc. leak, it may pose a danger to the surroundings, whereas liquid air leaks due to equipment damage, etc., or the amount of storage is too large to spontaneously enter the atmosphere. Even if it is released to, there is no problem in terms of pollution. Further, ammonia, hydrogen and the like require a dedicated raw material tank facility, but in the present invention, since the raw material is air, the atmosphere can be used as it is, and the raw material tank facility and the like are unnecessary. That is, the method of the present invention is safe and extremely easy to handle.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing an air liquefier, a storage tank, a carburetor, and a power generator used in the present invention.

FIG. 2 is a block diagram for explaining the method of the present invention.

FIG. 3 is a graph showing a power supply and demand state when the method of the present invention is used.

[Explanation of symbols]

 1 Air Liquefaction Device 2 Storage Tank 3 Vaporizer 4 Power Generation Device 23 Turbine A Air Liquefaction Process B Liquid Air Storage Process C Liquid Air Vaporization Process D Power Generation Device Driving Process

Claims (1)

[Claims] 1. A method of liquefying air using surplus power, storing this liquid air, and driving a turbine of a power generator by high pressure air obtained by vaporization of the liquid air to generate electricity, if necessary. Characterized power conversion storage method.