JPH02188628A - Compressed air storage device - Google Patents

Abstract

PURPOSE:To enhance the effective volume of a compressed air storage tank by arranging drop compensating elements which contract or expand the volume of the tank depending upon the increase or decrease in constant pressure inside the storage tank to take out compressed air under a constant pressure at a high extraction rate. CONSTITUTION:A compressed air storage tank 10 is installed on the ground and is connected to a gas turbine generator plant through an air pipeline 12, wherein a plurality of pressure drop compensating elements 11 are disposed inside the tank 10. The respective elements 11 are formed so that their volumes may contract above constant pressure and expands below constant pressure. It is thus possible to contract the elements 11 to increase the compressed air space in the tank 10 when compressed air is stored in the tank 10, and to expand the elements 11 to supply air at certain pressure with a pressure drop in the tank 10 caused by taking out compressed air when compressed air is supplied to a gas turbine and so forth from the tank 10.

Description

[Detailed Description of the Invention] The present invention relates to a compressed air storage device, and more specifically, compressed air made using surplus electricity at night is temporarily stored in the storage device, It is extracted from the storage device during peak power use during the day and used for gas turbine power generation, etc., and particularly improves the volumetric efficiency of the storage device.

Conventional technology In general, there is a very large difference in electricity demand between day and night, and the amount of electricity required at night is about 40% of that during the day. Development is required.

As for power storage technology, in addition to pumped storage power plants that are already in practical use, various technological developments are underway, such as storage battery systems and superconducting power storage systems.

One such method is the compressed air storage/peak power generation system that was put into practical use in West Germany.
The compressed air is stored in an underground tank built in a rock salt layer, and the compressed air is extracted during peak power usage during the day to increase the power generated by the gas turbine.

In the future, in response to the ever-increasing demand for electricity, nuclear power generation, whose construction is being curtailed, and oil-fired power generation, which has many problems with air pollution, will be replaced by R, NG, or coal gas as fuel to compensate for power shortages. It is expected that the power will be generated by gas turbines. In gas turbine power generation, 40% of the fuel
Since ~60% of the power is used for combinator power, it is very advantageous to generate power using compressed air storage and peak power generation methods. In addition, the compressed air storage/peak power generation method can obtain very high quality waste heat of about 180℃ when producing compressed air, and the compressed air power generation method can be used in any location, and can be used as a small power plant in the city. We can also expect U-shaped business development that combines thermal energy supply business as a distributed power source or as a power source for promoting remote areas in the mountains.

However, when trying to adopt the compressed air storage/peak power generation method mentioned above, it is necessary to construct a huge tank to store the compressed air. In Japan, where there are few solid rock layers and much soft ground, the construction costs of underground tanks are high, making it difficult to adopt them.

In addition, in order to effectively use stored compressed air for gas turbine power generation, it is necessary to extract air at a constant pressure, and the most desirable pressure for current gas turbines is around 10 kg/am. Even considering the advances in gas turbines, 60 kg/c is considered to be around 60 kg/c.

As a method for extracting air at a constant pressure from a compressed air storage device, a water head compensation system as shown in FIG. 8 has conventionally been provided. In this system, a water storage tank I is formed in the upper part, and the water storage tank I is connected to an underground tank 3 for compressed air storage via a water pipe 2, and the underground tank 3 is connected to a gas tank 3 via an air transport pipe 4. It is connected to a turbine power generation plant 5.

In addition, in this device, when the storage pressure in the underground tank 3 is 10 atm, the storage pressure is 100 m below the groundwater level, and when the storage pressure is 50 atm, it is 500 m below the groundwater level. : It is necessary to construct underground tank 3. FIG. 8(a) shows a state in which compressed air is stored in the underground tank 3 by operating the compression pump (not shown) of the gas turbine power generation plant 5 using surplus power during the night. At this time, water B in the underground tank 3 is pushed out to the reservoir l through the water supply tank 2, and the water level in the reservoir l is therefore rising. FIG. 8(b) shows a state in which compressed air is supplied from the underground tank 3 through the air transporting vibrator 4 to the gas turbine power generation plant 5 during the daytime to generate electricity. At this time,
Water B is fed into the underground tank 3 from the reservoir 1 through the water feed vibrator 2 as compressed air is extracted from the underground tank 3.

Problems to be Solved by the Invention As mentioned above, with the water head compensation method, it is necessary to construct a tank considerably deep underground for pressure compensation and safety reasons, and therefore it is difficult to adopt the water head compensation method due to cost. . In addition, in this method, air dissolved in water escapes from the opening with bubbles, causing a champagne phenomenon in which the pressure drops, which is a major unsolved problem.

On the other hand, when storing compressed air at low pressure, it is possible to install the storage tank above ground, which is preferable in terms of construction costs, but it is not possible to simply store low-pressure compressed air in an above-ground tank. , its volumetric efficiency becomes very low. For example, when storing compressed air at 11 atm in a tank of 10,000 @ 3 and extracting compressed air of 10 atm or higher, the amount of unextracted residual air will be 100,113 compared to the amount of extracted air of 10,000 C, and the extraction rate is 9%, which is very inefficient.

Therefore, the present invention aims at improving the volumetric efficiency of the storage tank by increasing the extracted air rate.

Means for Solving the Problems In order to achieve the above-mentioned object, the present invention provides a method for storing compressed air produced by nighttime electricity and supplying the stored compressed air to a gas turbine or the like for use in power generation. In the compressed air storage device to be installed, an element is installed in the storage tank that elastically compensates for the pressure drop by contracting the volume above a certain pressure and expanding when the pressure falls below a certain pressure. The present invention provides a storage device for compressed air that increases the proportion of compressed air.

Furthermore, the present invention provides, as the pressure drop compensating element, an as-built device in which a mechanical or rubber nonlinear spring such as a spring is housed in an elastic container, or a spring element made of liquefied gas and a latent heat storage material. It is characterized by using a structure in which the heat reservoir is housed in an elastic container.

In the compressed air storage device according to the present invention described above, the elastic pressure drop compensating element is built into the storage tank, so when compressed air is stored in the tank, the pressure compensating element contracts. While expanding the compressed air space in the storage tank, when supplying compressed air from the storage tank to a gas turbine, etc., the pressure drop compensating element expands as the pressure in the storage tank decreases due to the extraction of compressed air. It can send air at a constant pressure to a gas turbine, etc.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be explained in detail with reference to embodiments shown in the drawings.

1 to 3, 10 is a compressed air storage tank, and 11 is a large number of pressure drop Thi compensating elements built into the storage tank IO.

The compressed air storage tank 10 is installed on the ground, and is connected to the gas turbine power generation plant 5 via an air transport vibrator 12.

The pressure drop compensating element II described above contracts in volume when the pressure exceeds a certain pressure, and expands when the pressure falls below the -ratio. The pressure drop compensating element 2 basically consists of two elements: a non-linear spring element deformed under constant upward force and an elastic container element accommodating the spring.

The spring elements include mechanical springs, rubber springs, and gas springs, and among the springs, springs with a large reaction force and a large displacement under a constant load are preferably employed. Further, the elastic container is designed to have flexibility to easily deform in response to pressure changes, and to maintain sufficient pressure resistance and airtightness under high pressure.

The above-mentioned mechanical spring system is made by molding a donut-shaped disk into a conical shape] ■ The spring has a large load capacity in a small space, and a nonlinear spring with a wide range can be obtained depending on the ratio of free height and plate thickness. Most preferably used. It is also possible to use a plurality of disc springs in series or in parallel.

FIG. 4 shows an embodiment of the pressure drop compensating element 11 using a disc spring, in which the disc spring I5 is sealed in an elastic container 1G that can be deformed only in the vertical direction without load, and is a mechanical spring system. 1) This is a combination of spring 15 and a gas spring type air spring.

When using a rubber spring type, rubber of fender type material is suitably used, and the π-shaped rubber 17 as shown in FIG. 5(a) or the P I VOT as shown in FIG. 5(b) The molded rubber 17° is used as a non-linear spring, and the non-linear spring is housed in an elastic container to constitute the pressure drop compensating element II.

When using the above-mentioned rubber spring system as a spring element, the elastic container used is a container that expands and contracts in a direction parallel to the operating direction of the spring and does not deform in the right angle direction, as in the case where the mechanical spring system is used.

Gas spring systems use the phase change between gas and liquid as a nonlinear spring. Examples of liquefied gases used as spring elements include: Using a gaseous compound (Freon 134a, Freon 22, SFl, etc.) that liquefies at 0 to 50°C at O atmospheric pressure, the latent heat storage material is stored in an elastic container as a heat reservoir.
It constitutes a pressure drop compensation element.

This kind of pressure drop compensation element I, for example, Fig. 6 (a
A spherical rubber elastic container 16 having the configuration shown in Xb)
Inside, a plurality of metal capsules 18 filled with a latent heat storage material are placed, and a liquefied gas 19 is also placed. Figure 6 (
a) shows the pressure drop compensating element 1K during volume expansion, and the pressure drop compensating element! 1 is placed under an external pressure lower than the liquefaction pressure of the liquefied gas 19 (form when air is released), the heat storage material in the capsule 18 in the container 16 is melted, and the liquefied gas is vaporized. ing. FIG. 6(1)) shows the pressure drop compensating element II during volume contraction, and the pressure drop compensating element 11
When the capsule 18 is placed under an external pressure higher than the liquefaction pressure of the liquefied gas (the air storage mode), the heat storage material inside the capsule 18 is solidified, and the liquefied gas 19 is also liquefied.

In the case of an elastic container using the above gas spring system, there is no directionality in the action of the spring, so there is no need for the container to have directionality in deformation, but it is necessary to have sufficient barrier properties against air. is necessary.

As described above, the various spring elements described above are preferably used in combination of a mechanical spring system and a gas spring system, or a combination of a rubber spring system and a gas spring system.

As the elastic container, those having the configurations shown in Figures 7(a) and (b) are used, and the container 16° in Figure 7(a) is made of rubber or soft plastic as shown in Figure 6 above. It consists of a hollow body and is suitable for combination with a gas spring system. The container 16° in FIG. 7 (11) is a soft plastic deck 20, a metal disc 21. It is a bellows type formed from a ring 22, and is suitable for combination with a mechanical spring type or a rubber spring type. Furthermore, although not shown, a diaphragm type elastic container can be used in combination with an air spring.

In the embodiment shown in FIGS. 1 to 3, the volume of the compressed air storage tank 10 is 10,000 I3, and the pressure drop compensating element 11 built in the storage tank IO includes the gas spring system and Im A rubber ball of about 100mm is used. The pressure drop compensating element 11 has a volume of 2 of its original value above 10 atm.
It is designed for use at 10 atm and contracts to 0%. The pressure drop compensation element 11 is placed in the storage tank IO at a filling rate of 50% at a pressure J of 10 atmospheres or less. Therefore, as shown in FIG. 2, the compression pump (not shown) of the gas turbine power generation plant 5 is operated to send compressed air into the storage tank 10, and the compressed air is stored in the storage tank 10 at 11 atmospheres. In this case, since the filling rate in the storage tank IO of the pressure drop hli compensation element II is 10%, the storage tank I
0.9 million liters of compressed air at 11 atm is stored inside the chamber.

As shown in FIG. 3, the compressed air stored in the storage tank 10 using surplus power during the night is supplied from the storage tank 10 to the gas turbine power generation plant 5 through the air transport vibrator t2 during the day, and is used for power generation. We are using. At that time, compressed air is taken out from the storage tank 10 and
The pressure in 0 drops and the storage tank! The pressure drop compensating element 11 built into the
0 atmospheric pressure) is sent to the gas turbine power generation plant 5.

Therefore, when storing compressed air at 11 atm in the 10,000 liter storage tank 10 and extracting compressed air at 10 atm, the amount of extracted air will decrease slightly to 9,000 m3, but the amount of unextracted remaining air will be 5. 10,000 l'l, and the extraction rate is 15%. This is because when the above pressure drop compensating element 1 is not used, the amount of unextracted residual air is 10,000 I3, and the extraction rate of compressed air is 9%. It has been raised to

Effects of the Invention As is clear from the above explanation, the compressed air storage device according to the present invention has a built-in pressure drop compensating element that expands in volume when the pressure drops below a certain level, so that the compressed air storage device maintains a constant pressure. The compressed air can be extracted at a high extraction rate, increasing the effective volume of the storage tank. Further, since the pressure drop compensating element is extremely simple in that it is simply placed in a storage tank, it has various advantages such as being easy to implement.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram showing an embodiment of the present invention, Figs. 2 and 3 are explanatory diagrams of the operation of the above embodiment, Fig. 4 is a schematic diagram showing an embodiment of the pressure drop compensating element, and Fig. 5 (aXb) is a cross-sectional view showing a rubber spring type spring element, Figure 6 (aXb) is a cross-sectional view showing a gas spring type spring element, Figures 7 (a) and (b)
8 is a sectional view of an elastic container, and FIG. 8 (aXb) is a schematic diagram showing a conventional example. 5...Gas turbine power generation plant, 10...Storage tank, I[...Pressure drop compensation element, I2...Air transport pipe.

Claims (1)

[Scope of Claims] 1. In a compressed air storage device installed when storing compressed air generated by nighttime electricity and supplying the stored compressed air to a gas turbine etc. for use in power generation, etc. Compressed air characterized by having a built-in elastic pressure drop compensating element that contracts in volume when the pressure exceeds a certain pressure and expands when the pressure falls below a certain pressure, thereby increasing the proportion of extracted air. storage device. 2. The compressed air storage device according to claim 1, wherein the pressure drop compensating element comprises a mechanical or rubber nonlinear spring such as a disc spring housed in an elastic container. 3. The compressed air storage device according to claim 1, wherein the pressure drop compensating element has a configuration in which the liquefied gas is used as a spring element and the latent heat storage material is used as a heat reservoir, which is housed in an elastic container.