Liquid nitrogen leakage protection device, nitrogen-oxygen separation compressed air energy storage system and use method

Abstract

The invention relates to the technical field of liquid nitrogen protection, in particular to a liquid nitrogen leakage protection device, a nitrogen-oxygen separation compressed air energy storage system and a use method. A liquid nitrogen leakage protection device comprises an underground settlement ditch body suitable for being arranged below a liquid nitrogen tank body; and the delivery pipeline is suitable for being buried under the ground surface, the inlet end of the delivery pipeline is communicated with the underground settlement ditch body, and the outlet end of the delivery pipeline is suitable for extending out of the ground surface to be communicated with the external environment. The invention provides a liquid nitrogen leakage protection device, a compressed air energy storage system and a use method, and aims to solve the problems that when liquid nitrogen is stored in an independent tank body, if inclination and leakage occur, the liquid nitrogen can be quickly converted into a gas state from a liquid state, the surrounding environment space of the tank body can be quickly occupied, and the risk of nitrogen suffocation to nearby personnel exists.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of liquid nitrogen protection, and particularly relates to a liquid nitrogen leakage protection device, a nitrogen-oxygen separation compressed air energy storage system and a use method. BACKGROUND

[0002] The cryogenic liquefied compressed air energy storage technology is a new type of physical energy storage technology with long time and large capacity, and is in the initial stage of demonstration construction. The largest demonstration scale in the world has reached 60 MW / 600 MWh. As a new type of compressed air energy storage technology, it has the advantage of high power density compared with other technical routes, but its construction cost is high and the system efficiency is low, which leads to insufficient commercial competitiveness. In order to improve the technical popularization, the nitrogen-oxygen separation type liquefied compressed air energy storage technology is innovatively put forward, and the separation of nitrogen and oxygen in air is realized by using energy storage and release cycle, so as to improve the economic efficiency and commercial value of the project.

[0003] However, in this technical mode, since the liquid nitrogen is stored in an independent tank, if the tank is tilted or leaks, the liquid nitrogen will quickly convert from a liquid state to a gaseous state, and will quickly occupy the space around the tank, which will cause a risk of nitrogen asphyxiation to nearby personnel. SUMMARY

[0004] Therefore, the present application provides a liquid nitrogen leakage protection device, a nitrogen-oxygen separation compressed air energy storage system and a use method to solve the problem that, in the independent tank storage of liquid nitrogen, if the tank is tilted or leaks, the liquid nitrogen will quickly convert from a liquid state to a gaseous state, will quickly occupy the space around the tank, and will cause a risk of nitrogen asphyxiation to nearby personnel.

[0005] In a first aspect, the present application provides a liquid nitrogen leakage protection device, comprising: An underground settlement trench body adapted to be arranged below a liquid nitrogen tank body; An external delivery pipeline adapted to be buried below the ground surface, wherein an inlet end of the external delivery pipeline is in communication with the underground settlement trench body, and an outlet end of the external delivery pipeline is adapted to extend out of the ground surface to be in communication with an external environment.

[0006] When the liquid nitrogen tank body leaks, the liquid nitrogen converts from a liquid state to a gaseous state, and the nitrogen gas is driven to enter the inlet end of the external delivery pipeline and is transported to an environment far away from the liquid nitrogen tank body through the external delivery pipeline, thereby avoiding the accumulation of nitrogen gas near the liquid nitrogen tank body and eliminating the hidden danger to personnel safety.

[0007] In an optional embodiment, a flow guide fan is further included, and the flow guide fan is arranged in the external delivery pipeline.

[0008] In an optional embodiment, the flow guide fan is arranged in the inlet end.

[0009] In an alternative embodiment, the delivery pipeline comprises at least two variable cross-section segments, each of which has a larger inner diameter towards the inlet end than towards the outlet end.

[0010] In an alternative embodiment, the bottom of the underground settling trench is provided with a spiral flow guide segment, which is connected to the inlet end.

[0011] In an alternative embodiment, a filter screen is further included, which is arranged below the liquid nitrogen tank and above the underground settling trench.

[0012] In a second aspect, the present application further provides a nitrogen-oxygen separation compressed air energy storage system comprising the above-mentioned liquid nitrogen leakage protection device.

[0013] In an alternative embodiment, a liquid nitrogen tank, a liquid oxygen tank, an air compressor and a compressed energy storage auxiliary machine are further included, the air compressor is in communication with the compressed energy storage auxiliary machine, and the compressed energy storage auxiliary machine is in communication with the liquid nitrogen tank and the liquid oxygen tank, respectively.

[0014] In an alternative embodiment, an expansion energy release auxiliary machine and a nitrogen expander are further included, the liquid nitrogen tank is in communication with the expansion energy release auxiliary machine, and the expansion energy release auxiliary machine is in communication with the nitrogen expander.

[0015] In a third aspect, the present application further provides a method for using the liquid nitrogen leakage protection device. When the liquid nitrogen tank leaks, the liquid nitrogen is converted from a liquid state to a gaseous state, and the nitrogen gas is driven to enter the inlet end of the delivery pipeline and is delivered to an environment far away from the liquid nitrogen tank through the delivery pipeline. BRIEF DESCRIPTION OF DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the specific embodiments or prior art of the present application, the drawings needed in the specific embodiments or prior art description will be briefly introduced as follows. Obviously, the drawings in the following description are some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0017] Figure 1 FIG. 1 is a schematic diagram of a nitrogen-oxygen separation compressed air energy storage system according to an embodiment of the present application; Figure 2 FIG. 2 is a schematic diagram of a delivery pipeline according to an embodiment of the present application; Explanation of reference signs: 1, underground subsidence ditch body; 2, external delivery pipeline; 201, first variable cross-section section; 202, second variable cross-section section; 203, third variable cross-section section; 204, fourth variable cross-section section; 3, ground surface; 4, filter screen; 5, dispersing bridge; 6, liquid nitrogen tank body; 7, air compressor; 8, compressed energy storage auxiliary machine; 9, liquid oxygen tank body; 10, expansion energy release auxiliary machine; 11, nitrogen gas expander. DETAILED DESCRIPTION

[0018] To make the objectives, technical solutions, and advantages of the embodiments of the present application clearer, the following will be combined with the accompanying drawings for the embodiments of the present application to make a clear and complete description of the technical solutions in the embodiments of the present application. Obviously, the described embodiments are some but not all of the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0019] The embodiments of the present application are described below in combination with Figures 1 to 2 .

[0020] According to the embodiments of the present application, in one aspect, a liquid nitrogen leakage protection device is provided, which comprises: an underground subsidence ditch body 1, the underground subsidence ditch body 1 is adapted to be arranged below a liquid nitrogen tank body 6; and an external delivery pipeline 2, which is adapted to be buried below a ground surface 3, an inlet end of the external delivery pipeline 2 is in communication with the underground subsidence ditch body 1, and an outlet end of the external delivery pipeline 2 is adapted to extend out of the ground surface 3 to be in communication with an external environment.

[0021] When the liquid nitrogen tank body 6 leaks, the liquid nitrogen is converted into gaseous nitrogen, which is driven to enter into the inlet end of the external delivery pipeline 2, and is delivered to an environment far away from the liquid nitrogen tank body 6 through the external delivery pipeline 2, thereby avoiding the accumulation of nitrogen gas near the liquid nitrogen tank body 6 and eliminating the hidden danger to the safety of personnel. In the present embodiment, the underground subsidence ditch body 1 is not specifically limited, and the underground subsidence ditch body 1 can be a product made in a factory (a groove is first dug below the ground surface 3, and then the underground subsidence ditch body 1 is placed), or the underground subsidence ditch body 1 can be directly dug below the ground surface 3.

[0022] In one embodiment, as Figure 1As shown, the device also includes a flow guide fan, which is arranged in the outer delivery pipeline 2. The flow guide fan provides power to make the nitrogen entering the underground sedimentation ditch body 1 quickly enter the outer delivery pipeline 2, and then be delivered to the external environment far away from the liquid nitrogen tank body 6. In order to monitor the flow rate of nitrogen in the outer delivery pipeline 2, a flow rate sensor is installed in the underground sedimentation ditch body 1 to collect nitrogen flow rate related data. When a significant drop in flow rate is detected, the system will automatically increase the speed of the flow guide fan in the outer delivery pipeline 2 to restore normal flow rate by enhancing the power of the airflow. If the data collected by the sensor deviates from the preset threshold value, the system will immediately issue a warning signal to facilitate the staff to promptly troubleshoot the fault and ensure the stable and efficient operation of the entire liquid nitrogen leakage protection device.

[0023] In one embodiment, as shown in Figure 1 The flow guide fan is arranged in the inlet end to make the nitrogen quickly enter the outer delivery pipeline 2 through the inlet end.

[0024] In one embodiment, as shown in Figure 2 The outer delivery pipeline 2 includes at least two variable cross-section segments, and the inner diameter of each variable cross-section segment towards the inlet end is greater than that towards the outlet end. In this embodiment, the cross-section of the variable cross-section segment is trapezoidal, and the gradual change structure with the inner diameter towards the inlet end being greater than that towards the outlet end is adopted. This design can enhance the effect of the flow guide fan and optimize the airflow circulation.

[0025] In this embodiment, as shown in Figure 2 The variable cross-section segment of the outer delivery pipeline 2 is four segments, i.e., the first variable cross-section segment 201, the second variable cross-section segment 202, the third variable cross-section segment 203, and the fourth variable cross-section segment 204 arranged in sequence from the inlet end towards the outlet end, and the first variable cross-section segment 201, the second variable cross-section segment 202, the third variable cross-section segment 203, and the fourth variable cross-section segment 204 have the same structure and size, and the inner diameter of each variable cross-section segment towards the inlet end is greater than that towards the outlet end.

[0026] In one embodiment, as shown in Figure 1 The bottom of the underground sedimentation ditch body 1 is provided with a spiral flow guide segment, which is connected with the inlet end. The spiral structure design of the spiral flow guide segment is beneficial to the convergence and aggregation of nitrogen and accelerates the discharge of nitrogen. In addition, the lower part of the spiral structure is directly connected with the discharge pipeline, and the entire spiral part has a vibration function, which can clean the attached impurities and dust through periodic vibration (activated during manual maintenance), thereby avoiding the blockage of the pipeline by dust.

[0027] In one embodiment, as shown in Figure 1As shown, the device further comprises a filter screen 4 arranged below the liquid nitrogen tank 6 and above the underground settling channel 1, so as to prevent external impurities from entering the underground settling channel 1 and prevent the inlet end of the external delivery pipeline 2 from being blocked. It should be noted that the filter screen 4 is detachably arranged, and the structure of the detachable filter screen 4 is arranged below the liquid nitrogen tank 6 [1] and can adopt a dynamic adjustment grid form. By changing the grid spacing driven by the motor, the filtering precision can be flexibly adjusted to adapt to the impurity interception requirements under different working conditions.

[0028] In the embodiment, as shown in Figure 1 In order to facilitate the rapid evacuation of personnel when liquid nitrogen leaks, a dispersal bridge 5 is further arranged near the liquid nitrogen tank 6, and personnel can quickly evacuate to a safe area away from the liquid nitrogen tank 6 through the dispersal bridge 5.

[0029] According to the embodiment of the present application, on the other hand, a liquid nitrogen leakage protection device for a nitrogen-oxygen separation compressed air energy storage system is also provided.

[0030] In one embodiment, as shown in Figure 1 The device further comprises a liquid nitrogen tank 6, a liquid oxygen tank 9, an air compressor 7 and a compressed energy storage auxiliary machine 8. The air compressor 7 is in communication with the compressed energy storage auxiliary machine 8, and the compressed energy storage auxiliary machine 8 is in communication with the liquid nitrogen tank 6 and the liquid oxygen tank 9, respectively. In the compressed energy storage link, the air compressor 7 and the compressed energy storage auxiliary machine 8 are started, air is compressed and liquefied by renewable energy or grid surplus power, and liquid nitrogen and liquid oxygen are separated by using different boiling points, and are pumped into the liquid nitrogen tank 6 and the liquid oxygen tank 9, respectively.

[0031] In one embodiment, as shown in Figure 1 The device further comprises an expansion energy release auxiliary machine 10 and a nitrogen expander 11. The liquid nitrogen tank 6 is in communication with the expansion energy release auxiliary machine 10, and the expansion energy release auxiliary machine 10 is in communication with the nitrogen expander 11. In the expansion energy release link, the liquid nitrogen in the liquid nitrogen tank 6 is gasified and warmed by the expansion energy release auxiliary machine 10 to drive the nitrogen expander 11 to work and discharge high-purity nitrogen gas. The nitrogen gas can be captured and utilized or directly discharged into the atmosphere. The liquid oxygen in the liquid oxygen tank 9 can be directly filled and sold, or used in multiple applications.

[0032] According to the embodiment of the present application, on the other hand, a use method of a nitrogen-oxygen separation compressed air energy storage system is also provided, which comprises the following steps: (1) In the compressed energy storage link, the air compressor 7 and the compressed energy storage auxiliary machine 8 are started, air is compressed and liquefied by renewable energy or grid surplus power, and liquid nitrogen and liquid oxygen are separated by using different boiling points, and are pumped into the liquid nitrogen tank 6 and the liquid oxygen tank 9, respectively. (2) In the expansion energy release link, the liquid nitrogen in the liquid nitrogen tank 6 is gasified and heated by the expansion energy release auxiliary machine 10, and the nitrogen gas is driven to drive the nitrogen expander 11 to work and discharge high-purity nitrogen gas. The nitrogen gas can be captured and used or directly discharged into the atmosphere, and the liquid oxygen in the liquid oxygen tank 9 can be directly filled and sold, or multi-element application; (3) When the liquid nitrogen tank 6 leaks, the liquid nitrogen is converted from liquid to gas, and under the action of the flow guide fan, the nitrogen gas is driven into the inlet end of the external delivery pipeline 2, and is transported to the environment far away from the liquid nitrogen tank 6 through the external delivery pipeline 2, thereby avoiding the accumulation of nitrogen gas near the liquid nitrogen tank 6.

[0033] The liquid nitrogen leakage protection device and compressed air energy storage system provided by the application have the following advantages: (1) When the liquid nitrogen tank 6 leaks, the liquid nitrogen is converted from liquid to gas, and the nitrogen gas is driven into the inlet end of the external delivery pipeline 2, and is transported to the environment far away from the liquid nitrogen tank 6 through the external delivery pipeline 2, thereby avoiding the accumulation of nitrogen gas near the liquid nitrogen tank 6, and eliminating the hidden danger to personnel safety; (2) The flow guide fan is arranged to quickly introduce the nitrogen gas into the external delivery pipeline 2, thereby reducing the nitrogen gas density near the liquid nitrogen tank 6; (3) The spiral structure design of the spiral flow guide section is beneficial to the flow and accumulation of nitrogen gas, and accelerates the discharge of nitrogen gas. In addition, the lower part of the spiral structure is directly connected to the discharge pipeline, and the entire spiral part has a vibration function, which can clean the attached impurities and dust through periodic vibration (activated during manual maintenance), thereby avoiding the blockage of the pipeline by dust; (4) The liquid nitrogen tank 6 is also provided with a dispersing bridge 5, and personnel can quickly evacuate to a safe area away from the liquid nitrogen tank 6 through the dispersing bridge 5; (5) For the nitrogen-oxygen separation type liquefied compressed air energy storage system with independent liquid nitrogen storage requirements, a safety protection system arrangement scheme is designed around the potential risk scenarios such as inclination or leakage of the liquid nitrogen tank 6, which can provide support and protection for personnel evacuation and emergency rescue in the emergency scenario of liquid nitrogen or low-temperature nitrogen gas ground accumulation and flow; (6) In view of the frequent storage and removal of the working medium in the liquid nitrogen tank 6, which causes large temperature fluctuation of the liquid nitrogen and leads to leakage or fatigue cracks of the liquid nitrogen tank 6, and the area aggregation after the liquid nitrogen leaks affects the safety of personnel, the liquid nitrogen leakage protection device is designed to ensure the safety of the on-site personnel and facilitate the effective mitigation of the nitrogen suffocation risk caused by small-scale liquid nitrogen leakage.

[0034] As an alternative embodiment, the flow guide fan can also be arranged at the middle section of the external delivery pipeline 2 or at the outlet end of the external delivery pipeline 2.

[0035] As an alternative embodiment, the number of variable cross-section segments of the external delivery pipeline 2 can also be two, three, five or more.

[0036] As an alternative embodiment, the first, second, third and fourth variable cross-section segments 201, 202, 203 and 204 can also have different structural dimensions.

[0037] While embodiments of the application have been described in connection with the preferred embodiments of the various figures, modifications and / or additions, which do not depart from the spirit and scope of the claimed application, are intended to be within the scope of the claims.

Claims

1. A liquid nitrogen leakage protection device suitable for a nitrogen-oxygen separation compressed air energy storage system, characterized in that, Comprising: a subterranean sink body (1) adapted to be disposed below a liquid nitrogen tank body (6); an outfeed conduit (2) adapted to be buried below a ground surface (3), an inlet end of the outfeed conduit (2) being in communication with the subterranean sink body (1), an outlet end of the outfeed conduit (2) being adapted to protrude above the ground surface (3) to be in communication with an external environment.

2. The liquid nitrogen spill guard of claim 1, wherein, Further comprising a flow guide fan disposed within the outfeed conduit (2).

3. The liquid nitrogen spill guard of claim 2, wherein, The flow guide fan is disposed within the inlet end.

4. The liquid nitrogen spill guard of claim 3, wherein, The outfeed conduit (2) comprises at least two variable cross-section segments, each of the variable cross-section segments having a larger inner diameter towards the inlet end than towards the outlet end.

5. The liquid nitrogen spill guard of claim 3, wherein, A spiral flow guide segment is disposed at a bottom of the subterranean sink body (1), the spiral flow guide segment being connected to the inlet end.

6. The liquid nitrogen spill guard of claim 1, wherein, Further comprising a filter screen (4) disposed below the liquid nitrogen tank body (6), the filter screen (4) being disposed above the subterranean sink body (1).

7. A nitrogen-oxygen separation compressed air energy storage system, characterized by, The liquid nitrogen leak protection device of any one of claims 1-6.

8. The N2 / O2 separation compressed air energy storage system of claim 7, wherein, Further comprising a liquid nitrogen tank body (6), a liquid oxygen tank body (9), an air compressor (7), and a compressed energy storage auxiliary machine (8), the air compressor (7) being in communication with the compressed energy storage auxiliary machine (8), the compressed energy storage auxiliary machine (8) being in communication with the liquid nitrogen tank body (6) and the liquid oxygen tank body (9), respectively.

9. The N2 / O2 separation compressed air energy storage system of claim 8, wherein, Further comprising an expansion energy release auxiliary machine (10) and a nitrogen gas expander (11), the liquid nitrogen tank body (6) being in communication with the expansion energy release auxiliary machine (10), the expansion energy release auxiliary machine (10) being in communication with the nitrogen gas expander (11).

10. A method of using a liquid nitrogen leak protection device for use with the liquid nitrogen leak protection device of claim 1, the method comprising: Upon a leak of the liquid nitrogen tank body (6), the liquid nitrogen is converted from a liquid state to a gaseous state, and the nitrogen gas is driven to enter the inlet end of the outfeed conduit (2) and is transported through the outfeed conduit (2) to an environment away from the liquid nitrogen tank body (6).

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