Compressed air energy storage underground cavern arrangement method

Abstract

The invention relates to the field of novel energy storage, and provides a compressed air energy storage underground cavern arrangement method in order to reduce dependence on a compression process while reducing a high-temperature or ultra-high-temperature phenomenon. And the temperature is adjusted by utilizing the self temperature difference of the sequentially filled gases, so that the dependence on the compression process is reduced while the high-temperature or ultrahigh-temperature phenomenon is reduced.

Description

Technical Field

[0001] The invention relates to the field of novel energy storage, and in particular to a method for arranging underground caverns for compressed air energy storage. Background Art

[0002] Compressed air energy storage is a form of energy storage with broad prospects and is currently being vigorously developed in my country. For compressed air energy storage, the pressure of filling and storing air is relatively high, and at this stage it can reach 10MPa level and above. For underground gas storage, there are currently two main types of gas storage: tunnel type and large tank type. The construction technology of tunnel type gas storage is relatively mature, and the construction progress and construction quality are easier to control. However, for traditional "one"-shaped tunnel type gas storage, the airflow is not easy to mix. The filling and storage of high-pressure gas will inevitably form high temperature or ultra-high temperature in the "one"-shaped tunnel type gas storage. The control of high temperature or ultra-high temperature has become one of the key difficulties restricting the large-scale application of compressed air energy storage.

[0003] At present, the control of high or ultra-high temperature mainly relies on the research and development or use of new compressor equipment. This method is highly dependent on the compression process and has high investment costs. Summary of the invention

[0004] In order to reduce high temperature or ultra-high temperature phenomena while reducing dependence on compression technology, the present application provides a method for arranging underground caverns for compressed air energy storage.

[0005] The technical solution adopted by the present invention to solve the above problems is:

[0006] The method for arranging an underground cavern for compressed air energy storage includes:

[0007] An annular gas storage layout is adopted; the air inlet position is determined based on the gas storage layout; a transient method is used based on numerical simulation software to study the temperature change over time. If the maximum temperature in the reservoir exceeds the temperature threshold during normal operation, the gas storage layout is adjusted until the maximum temperature meets the requirements.

[0008] Furthermore, the gas storage is a four-straight-line annular gas storage.

[0009] Furthermore, the method for determining the layout form of the gas storage is: determining the length of the gas storage according to the cross-sectional size and the volume of the gas storage; and determining the layout form of the four-straight-line annular gas storage according to the length of the gas storage.

[0010] Furthermore, the cross section of the gas storage is circular, and the hole diameter is within 10m to 12m.

[0011] Furthermore, the four-straight-line annular gas storage is composed of four straight lines and a transition arc, wherein the ratio of the long straight line side to the short straight line side is between 1:1 and 20:1.

[0012] Furthermore, the distance between the two long side axes is ≥ 5 times the hole diameter.

[0013] Furthermore, the central angle of the transition arc is 90°, and the turning radius is ≥ 1 times the hole diameter.

[0014] Furthermore, the angle between the axis of the two long straight sides and the maximum principal stress is ≤30°, and the angle between the axis of the two long straight sides and the structural surface is ≥100°. If these conditions cannot be met at the same time, the finite element calculation is used to determine the priority condition to ensure the stability of the surrounding rock under the inflation state.

[0015] Furthermore, the number of the air inlet is 1, which is located on a long side and within a distance of 5-10 m from the transition arc.

[0016] Further, the air inlet is arranged parallel to the long side axis.

[0017] Compared with the prior art, the present invention has the following beneficial effects: the annular gas storage arrangement is adopted so that the gas filled first and the gas filled later can be connected end to end, so that the gases filled in successively are mixed more evenly, and the temperature difference of the gases filled in successively is used to adjust the temperature, thereby reducing the high temperature or ultra-high temperature phenomenon while reducing the dependence on the compression process. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the structure of a four-straight-line annular gas storage reservoir;

[0019] Figure 2 This is a schematic diagram of the temperature distribution law of the underground gas storage of a hydropower station during the gas storage process from 6-10MPa;

[0020] Figure numerals: 1 is the long side axis; 2 is the short straight side; 3 is the long straight side; 4 is the transition arc; 5 is the air inlet; 6 is the high-pressure airflow; 7 is the distance between the two long side axes; 8 is the turning radius. DETAILED DESCRIPTION

[0021] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0022] The method for arranging an underground cavern for compressed air energy storage includes:

[0023] The annular gas storage layout is adopted, such as Figure 1 As shown, this embodiment conducts research on the layout of gas storage reservoirs in surrounding rock of Class III or above and with rock uniaxial compressive strength ≥60 MPa, requiring that after the high-pressure airflow 6 is filled in, the surrounding rock stability and anti-lift stability requirements are met at the same time.

[0024] A four-straight-line annular gas storage is adopted, which consists of four straight lines and a transition arc 4. The cross-section of the gas storage is circular, and the hole diameter is within 10m~12m. The length of the gas storage is determined according to the cross-section size and the volume of the gas storage. Among them, the long straight side 3 / short straight side 2 is between 1:1~20:1, and the distance between the two long side axes 7 is ≥5 times the hole diameter; the central angle of the transition arc 4 is 90°, and the turning radius 8 is ≥1 times the hole diameter; the angle between the two long straight side axes and the maximum principal stress is ≤30°, and the angle between the two long straight side axes and the structural surface is ≥100°. If these two conditions cannot be met at the same time, the priority condition is determined according to the stability of the surrounding rock through finite element calculation.

[0025] The position of the air inlet 5 is determined based on the layout of the gas storage. The number of air inlet 8 is 1, which is located on a long side, within 5-10m from the transition arc, and the air inlet 5 is arranged parallel to the long side axis 1. The arrangement of the air inlet parallel to the long side axis is conducive to the rapid entry of air into the gas storage and the formation of circulation.

[0026] Based on the numerical simulation software, the transient method is used to study the temperature change over time. The inlet temperature of the high-pressure gas 6 should be basically consistent with the room temperature. The mass flow is converted according to the inflation pressure. The inflation time should be less than 1 day. If the maximum temperature in the reservoir exceeds the temperature threshold during normal operation, the layout of the gas storage reservoir is adjusted until the maximum temperature meets the requirements. In this embodiment, the inflation time is 8 hours, and the temperature change is as follows Figure 2 As shown in the figure, the long and short sides and transition arcs of the initially proposed annular gas storage are compared and simulated to determine the final dimensions of each part, and finally the optimal annular gas storage layout suitable for engineering applications is obtained.

[0027] The annular gas storage layout realizes the connection between the gases filled in successively, and uses the temperature difference of the gas itself to cool it down, effectively avoiding the high temperature and ultra-high temperature phenomenon of traditional "I"-shaped tunnel gas storage.

Claims

1. A method for arranging an underground cavern for compressed air energy storage, characterized in that: include: Adopting the annular gas storage layout; Determine the location of the air inlet based on the layout of the gas storage; Based on numerical simulation software, a transient method is used to study the temperature change over time. If the maximum temperature in the reservoir exceeds the temperature threshold during normal operation, the layout of the gas storage reservoir is adjusted until the maximum temperature meets the requirements.

2. The method for arranging an underground cavern for compressed air energy storage according to claim 1, characterized in that: The gas storage is a four-linear annular gas storage.

3. The method for arranging underground caverns for compressed air energy storage according to claim 2, characterized in that: The method for determining the layout form of the gas storage reservoir is as follows: determine the length of the gas storage reservoir based on the cross-sectional size and the volume of the gas storage reservoir; and determine the layout form of the four-straight-line annular gas storage reservoir based on the length of the gas storage reservoir.

4. The method for arranging underground caverns for compressed air energy storage according to claim 3 is characterized in that: The cross section of the gas storage is circular, and the hole diameter is between 10m and 12m.

5. The method for arranging underground caverns for compressed air energy storage according to claim 2, characterized in that: The four-straight-line annular gas storage is composed of four straight lines and a transition arc, wherein the ratio of the long straight line side to the short straight line side is between 1:1 and 20:

1.

6. The method for arranging underground caverns for compressed air energy storage according to claim 5, characterized in that: The distance between the two long side axes is ≥ 5 times the hole diameter.

7. The method for arranging underground caverns for compressed air energy storage according to claim 5, characterized in that: The center angle of the transition arc is 90°, and the turning radius is ≥ 1 times the hole diameter.

8. The method for arranging underground caverns for compressed air energy storage according to claim 5, characterized in that: The angle between the axis of the two long straight sides and the maximum principal stress is ≤30°, and the angle between the axis of the two long straight sides and the structural surface is ≥100°. If both conditions cannot be met at the same time, the finite element calculation is used to determine the priority condition to ensure the stability of the surrounding rock under the inflation state.

9. The method for arranging underground caverns for compressed air energy storage according to claim 5, characterized in that: The number of air inlets is 1, located on a long side, and the distance from the transition arc is within 5-10m.

10. The method for arranging underground caverns for compressed air energy storage according to claim 9, characterized in that: The air inlet is arranged parallel to the long side axis.

Images