Natural gas cold energy dehumidification system

Abstract

The utility model relates to the field of natural gas dehydration, and discloses a natural gas cold energy dehumidification system which comprises a dehumidification structure and a water storage buffer tank, a flow meter is arranged on a gas inlet pipe of a high-pressure natural gas pipeline, the dehumidification structure comprises a dehumidification box body communicated with the high-pressure natural gas pipeline, and a heat exchange pipeline is arranged in the dehumidification box body. Low-temperature flash steam circulates in the heat exchange pipeline, a flow control valve used for controlling the flow of the low-temperature flash steam is arranged on the heat exchange pipeline, the bottom of the dehumidification box communicates with a water storage buffer tank through a pipeline, and a drainage valve is arranged at the bottom of the water storage buffer tank. Natural gas in the high-pressure natural gas conveying pipeline is cooled through low-temperature flash steam guided out of the LNG storage tank, so that water vapor mixed in the natural gas is liquefied when meeting cold, collected condensate water is discharged in time, the dehumidification system can continuously and automatically work, the water vapor content in the natural gas is reduced, and the energy consumption is reduced. The dehumidification device has the advantages of simple structure, low cost and excellent dehumidification effect.

Description

Technical Field

[0001] The utility model relates to the technical field of natural gas dehydration, in particular to a natural gas cold energy dehumidification system. Background Art

[0002] The liquefied natural gas (LNG) production process involves purifying natural gas to remove impurities such as carbon dioxide, sulfides, hydrocarbons, and water. The gas is then cooled to -162°C, condensing it into a liquid. The volume of LNG is approximately 1 / 625 of the volume of the same amount of gaseous natural gas. Therefore, ultra-low temperature liquefaction of natural gas at normal pressure significantly saves storage and transportation space. The LNG can then be re-gasified for use.

[0003] Although the natural gas manufacturing process includes a purification step, a small amount of water vapor is inevitably present in the finished natural gas. During long-term use, the water in the upstream, incompletely dehydrated natural gas in the natural gas pipeline at a natural gas station will liquefy into liquid water when it is cooled, accumulating in large quantities and even freezing and clogging the pipeline. To reduce the frequency of pipeline icing and blockage, it is necessary to capture as much water vapor as possible from the natural gas, thereby significantly reducing its water vapor content. However, existing dehumidification equipment is not fully suitable for high-pressure natural gas dehumidification, and most of them have complex structures and high maintenance costs. Therefore, it is necessary to design a dehumidification device specifically for natural gas. Utility Model Content

[0004] In response to the problems existing in the prior art: the existing dehumidification equipment is not fully suitable for dehumidifying natural gas in high-pressure natural gas transmission pipelines. The purpose of this utility model is to provide a natural gas cold energy dehumidification system, which uses low-temperature flash gas derived from LNG storage tanks to cool the natural gas in the high-pressure natural gas transmission pipeline, so that the water vapor mixed in the natural gas is cooled and liquefied, and the collected condensed water is discharged in time, so that the dehumidification system can work continuously and automatically, thereby greatly reducing the water vapor content in the natural gas. It has the advantages of simple structure, low cost and excellent dehumidification effect.

[0005] In order to achieve the above-mentioned purpose, the technical solution of the utility model is:

[0006] A natural gas cold energy dehumidification system is connected to a high-pressure natural gas pipeline and includes a dehumidification structure and a water storage buffer tank. A flow meter is provided on the air inlet pipe of the high-pressure natural gas pipeline. The dehumidification structure includes a dehumidification box body connected to the high-pressure natural gas pipeline. A heat exchange pipeline is provided in the dehumidification box body. Low-temperature flash gas flows in the heat exchange pipeline and a flow control valve for controlling the flow of low-temperature flash gas is provided on the heat exchange pipeline. The bottom of the dehumidification box body is connected to the water storage buffer tank through a pipeline. A drainage control valve is provided on the pipeline connecting the dehumidification box body and the water storage buffer tank. A drainage valve is provided at the bottom of the water storage buffer tank. The top of the water storage buffer tank is connected to a safety venting system through a pipeline and an exhaust valve is provided on the pipeline connecting the water storage buffer tank and the safety venting system.

[0007] The utility model is further configured as follows: the dehumidification box includes a first-stage dehumidification box, and a plurality of cold energy release plates whose height is lower than that of the first-stage dehumidification box are arranged in the first-stage dehumidification box, and all the cold energy release plates are alternately fixed at the top and bottom of the first-stage dehumidification box so that the high-pressure natural gas is continuously turned in the first-stage dehumidification box, and low-temperature flash gas flows in the cold energy release plates.

[0008] The utility model is further configured as follows: each of the cold energy release plates is independently connected to the main pipeline of the low-temperature flash gas, and a first flow control valve is provided on the pipeline connecting each of the cold energy release plates and the main pipeline of the low-temperature flash gas.

[0009] The utility model is further configured as follows: the air inlet pipe of the high-pressure natural gas pipeline is located at the top of the first-level dehumidification box body, and the end of the air inlet pipe is provided with an air inlet opening vertically downward.

[0010] The present invention is further configured as follows: the dehumidification box body also includes a secondary dehumidification box body, the position of the secondary dehumidification box body is higher than the primary dehumidification box body, and the top of the primary dehumidification box body is connected to the side wall position of the bottom of the secondary dehumidification box body.

[0011] The utility model is further configured as follows: a plurality of circulation coils are arranged in the secondary dehumidification box, and all the circulation coils are arranged at intervals in the height direction of the secondary dehumidification box, and low-temperature flash gas flows in the circulation coils.

[0012] The utility model is further configured as follows: each of the circulation coils is arranged to form a grid structure, each of the circulation coils is independently connected to the main pipeline of the low-temperature flash gas, and a second flow control valve is provided on the pipeline connecting each of the circulation coils to the main pipeline of the low-temperature flash gas.

[0013] The present invention is further configured as follows: a first temperature sensor is provided at the connection point between the first-level dehumidification box and the high-pressure natural gas pipeline, and at the connection point between the first-level dehumidification box and the second-level dehumidification box. The first temperature sensor is used to detect the temperature of the high-pressure natural gas at different positions in the first-level dehumidification box, and a second temperature sensor is provided above each of the circulation coils in the second-level dehumidification box to detect the temperature of the high-pressure natural gas at different positions in the second-level dehumidification box.

[0014] The present invention is further configured as follows: a first liquid level sensor and a second liquid level sensor are respectively provided at the bottom of the first-stage dehumidification box and the second-stage dehumidification box, and the first liquid level sensor and the second liquid level sensor are respectively used to detect the water levels in the first-stage dehumidification box and the second-stage dehumidification box.

[0015] The utility model is further configured as follows: it also includes a controller, a third liquid level sensor and a pressure sensor are provided on the water storage buffer tank, the controller is electrically connected to the flow meter, the first temperature sensor, the second temperature sensor, the first liquid level sensor, the second liquid level sensor, the third liquid level sensor and the pressure sensor and receives their electrical signals, and the controller controls the opening degree of all the first flow control valve, the second flow control valve, the first drain control valve, the second drain control valve, the drain valve and the exhaust valve.

[0016] In summary, the beneficial effects achieved by the present invention are as follows:

[0017] (1) The high-pressure natural gas pipeline is connected to the dehumidification box. Low-temperature flash gas flows through the cold energy release plate and the circulation coil installed in the dehumidification box. When the high-pressure natural gas enters the dehumidification box, it contacts the cold energy release plate and the circulation coil for heat exchange. Since the liquefaction temperature of natural gas is much lower than the liquefaction temperature of water vapor, only a small amount of water vapor mixed in the high-pressure natural gas will be cooled and liquefied into droplets before and after the heat exchange. It will adhere to the cold energy release plate and the circulation coil and drip to the bottom of the dehumidification box under the action of gravity. The bottom of the dehumidification box is connected to the water storage buffer tank through a pipeline, and the accumulated water in the dehumidification box is discharged into the water storage buffer tank, thereby achieving effective dehumidification of the high-pressure natural gas;

[0018] (2) All the cold energy release plates in the first-stage dehumidification box are alternately fixed at the top and bottom of the first-stage dehumidification box so that the high-pressure natural gas is continuously turned in the first-stage dehumidification box, thereby prolonging the contact time between the high-pressure natural gas and the cold energy release plates, which is conducive to the full condensation of water vapor in the natural gas; at the same time, the circulation coils in the second-stage dehumidification box are arranged to form a grid structure and are arranged at intervals in the height direction of the second-stage dehumidification box, thereby expanding the contact area between the high-pressure natural gas and the circulation coils, which is conducive to the full condensation of water vapor in the natural gas;

[0019] (3) The dehumidification box includes a primary dehumidification box and a secondary dehumidification box, each of which is provided with a cold energy release plate and a grid-shaped circulation coil. The secondary dehumidification box is located higher than the primary dehumidification box, so that the high-pressure natural gas is initially condensed and dehydrated in the primary dehumidification box and then enters the secondary dehumidification box for further condensation and dehydration. This arrangement greatly improves the dehydration effect of the dehumidification structure and reduces the water content of the high-pressure natural gas.

[0020] (4) A first temperature sensor is provided in the first-stage dehumidification box to detect the temperature of the high-pressure natural gas at different positions, and a second temperature sensor is provided in the second-stage dehumidification box to detect the temperature of the high-pressure natural gas at different positions. Each cold energy release plate and each circulation coil are independently connected to the main pipeline of the low-temperature flash gas, and the first flow control valve and the second flow control valve are used to control the flow of the low-temperature flash gas in the pipeline, so as to adjust the cold amount released by each cold energy release plate and the circulation coil according to the actual temperature in the dehumidification box, while ensuring the condensation effect of water vapor and avoiding the freezing and solidification of water vapor on the cold energy release plate or the circulation coil due to too low a temperature;

[0021] (5) By electrically connecting the flow meter and the sensors on the first-stage dehumidification box, the second-stage dehumidification box and the water buffer tank to the controller, and the controller adjusting the valve opening and switch of all control valves online in real time, the adjustment is more timely and accurate, thus realizing the automation of the dehumidification system. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the specification. Obviously, the drawings described below are only some embodiments recorded in the present invention. For ordinary technicians in this field, other drawings can also be obtained based on these drawings.

[0023] Figure 1 This is a schematic diagram of the structure of the natural gas cooling dehumidification system in Example 1 of the present utility model;

[0024] Figure 2 This is a top view of the circulation coil in the secondary dehumidification box in Example 1 of the present utility model;

[0025] Figure 3 This is a schematic diagram of the control principle of the natural gas cooling dehumidification system in Example 2 of the present utility model.

[0026] In the figure: 1. High-pressure natural gas pipeline; 11. Air inlet pipe; 12. Exhaust pipe; 13. Flow meter; 14. Air inlet; 2. Dehumidification structure; 21. First-stage dehumidification box; 211. Cold energy release plate; 2111. Fin; 212. Support plate; 213. First temperature sensor; 214. First flow control valve; 215. First liquid level sensor; 216. First drain control valve; 22. Second-stage dehumidification box; 221. Circulating coil; 222. Second temperature sensor; 223. Second flow control valve; 224. Second liquid level sensor; 225. Second drain control valve; 3. Water storage buffer tank; 31. Drain valve; 32. Exhaust valve; 33. Third liquid level sensor; 34. Pressure sensor. DETAILED DESCRIPTION

[0027] The technical solutions in the embodiments of the present invention are described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. For ease of explanation, the terms "vertical", "horizontal", "left", "right", "up", "down", "inside", "outside", "bottom", etc. used in this specification to indicate directions or positional relationships are based on the directions or positional relationships shown in the drawings. They are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or components referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they should not be understood as limiting the present application.

[0028] It should be noted that the embodiments of the present invention and the features involved in the embodiments can be combined with each other without conflict. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0029] Example 1

[0030] As attached Figure 1 As shown, a natural gas cold energy dehumidification system includes a high-pressure natural gas pipeline 1, a dehumidification structure 2, and a water buffer tank 3. High-pressure natural gas pipeline 1 transports high-pressure natural gas from upstream of a natural gas station to the station. Before entering downstream, the high-pressure natural gas passes through dehumidification structure 2 for dehydration and dehumidification.

[0031] The dehumidification structure 2 comprises a connected primary dehumidification box 21 and a secondary dehumidification box 22. After entering the dehumidification structure 2, high-pressure natural gas first enters the primary dehumidification box 21 and then the secondary dehumidification box 22. Specifically, the high-pressure natural gas pipeline 1 includes an intake pipe 11 connected to the primary dehumidification box 21 and an exhaust pipe 12 connected to the secondary dehumidification box 22. A flow meter 13 is also installed on the intake pipe 11 to measure the flow rate of the high-pressure natural gas.

[0032] Since the density of high-pressure natural gas is lower than that of condensed water, the connection points between the air inlet pipe 11 and the exhaust pipe 12 and the first-stage dehumidification box 21 are both located at the top of the first-stage dehumidification box 21, and the air inlet pipe 11 and the exhaust pipe 12 are respectively located at the head and tail ends of the first-stage dehumidification box 21.

[0033] In order to prevent condensed water on the top of the primary dehumidification box 21 from falling into the air inlet pipe 11, an air inlet 14 opening vertically downward is provided at the end of the air inlet pipe 11.

[0034] The primary dehumidification box 21 is a rectangular box structure, and a plurality of cold energy release plates 211 are arranged inside and along the length direction thereof, and the height of the cold energy release plates 211 is lower than that of the primary dehumidification box 21. In this embodiment, the number of the cold energy release plates 211 is five.

[0035] The cold energy release plate 211 is a rectangular plate structure, and its width size is adapted to the first-level dehumidification box 21. The five cold energy release plates 211 are alternately fixed on the top and bottom of the first-level dehumidification box 21, so that the high-pressure natural gas is continuously turned when circulating in the first-level dehumidification box 21, thereby extending the contact time between the high-pressure natural gas and the cold energy release plate 211, which is beneficial to the sufficient heat exchange and condensation of water vapor in the natural gas.

[0036] The cold energy release plate 211 connected to the top of the first-level dehumidification box 21 is directly fixed to the top plate of the first-level dehumidification box 21; the cold energy release plate 211 connected to the bottom of the first-level dehumidification box 21 is fixed to the bottom plate of the first-level dehumidification box 21 through the support plate 212.

[0037] The width of the support plate 212 is the same as that of the cold energy release plate 211. The support plate 212 is located between the cold energy release plate 211 and the bottom plate of the first-level dehumidification box 21, and a through hole is opened on the support plate 212 for the condensed water at the bottom of the first-level dehumidification box 21 to pass through.

[0038] Low-temperature flash gas circulates within the cold energy release plate 211. Low-temperature flash gas is a gaseous form of natural gas. LNG readily vaporizes at room temperature, and even with excellent insulation in LNG cryogenic storage tanks, a standard evaporation rate of approximately 0.12% per day is unavoidable. The evaporation of LNG within the cryogenic tank forms flash gas (BOG). BOG (Boil-Off Gas) is continuously generated within the LNG cryogenic tank. Large amounts of BOG can cause pressure to increase within the tank. To maintain stable tank pressure, excess BOG must be discharged and processed. The temperature of BOG discharged from the LNG tank is approximately -107°C, providing excellent cold energy reserves. Since the liquefaction temperature of natural gas is -162°C, low-temperature flash gas (BOG) cannot condense the natural gas into a liquid state. Instead, it can be used to cool the water vapor in the high-pressure natural gas for dehumidification.

[0039] Each cold energy release plate 211 is independently connected to the main pipeline that discharges low-temperature flash gas. Furthermore, each cold energy release plate 211 is equipped with a first flow control valve 214 on the pipeline connecting it to the main pipeline. Therefore, adjusting the opening of the first flow control valve 214 can adjust the cooling capacity of the cold energy release plate 211, thereby increasing or decreasing the cooling effect on the water vapor mixed in the high-pressure natural gas. Furthermore, adjusting different first flow control valves 214 allows for precise adjustment of the cooling effect of each cold energy release plate 211.

[0040] The cold energy release plate 211 is further provided with fins 2111 for improving heat conduction efficiency. The fins 2111 are preferably made of a metal material with high thermal conductivity, such as aluminum.

[0041] The secondary dehumidification box body 22 is positioned higher than the primary dehumidification box body 21 , and the top of the primary dehumidification box body 21 and the side wall of the bottom of the secondary dehumidification box body 22 are connected through a pipeline.

[0042] As attached Figure 1 and attached Figure 2 As shown, a plurality of circulation coils 221 are provided in the secondary dehumidification box 22. In this embodiment, there are three circulation coils 221. Each circulation coil 221 is arranged in a bent manner to form a grid structure, thereby expanding the contact area between the high-pressure natural gas and the circulation coil 221, which is conducive to the full condensation of water vapor in the natural gas.

[0043] Low-temperature flash gas flows through the circulation coil 221 , and the three circulation coils 221 are arranged at equal intervals in the height direction within the secondary dehumidification box 22 .

[0044] Each circulating coil 221 is independently connected to the main pipeline for low-temperature flash gas. Furthermore, a second flow control valve 223 is installed on the pipeline connecting each circulating coil 221 to the main pipeline for low-temperature flash gas. Therefore, adjusting the opening of the second flow control valve 223 can adjust the cooling capacity of the circulating coil 221, thereby increasing or decreasing the cooling effect on the water vapor mixed in the high-pressure natural gas. Furthermore, adjusting different second flow control valves 223 can precisely adjust the cooling effect of each circulating coil 221.

[0045] The bottom of the first-stage dehumidification box 21 and the bottom of the second-stage dehumidification box 22 are connected to the top of the water buffer tank 3 through their own independent pipelines, and the pipelines from the first-stage dehumidification box 21 and the second-stage dehumidification box 22 to the water buffer tank 3 are respectively provided with a first drainage control valve 216 and a second drainage control valve 225 for controlling the on-off of the pipelines.

[0046] The primary dehumidification housing 21 and the secondary dehumidification housing 22 are each equipped with a first level sensor 215 and a second level sensor 224 for detecting the condensate level at the housing bottom. When the condensate level reaches the set drain line, the drain control valve opens for a specified period, allowing the condensate to drain through the pipeline into the water buffer tank 3. To prevent high-pressure natural gas from being discharged into the water buffer tank 3, personnel control the opening time and degree of the first drain control valve 216 and the second drain control valve 225, respectively, to ensure that a small amount of condensate remains at the bottom of the primary and secondary dehumidification housings 21 and 22.

[0047] A first temperature sensor 213 is installed at the connection point between the primary dehumidification box 21 and the exhaust pipe 12, as well as at the connection point between the primary dehumidification box 21 and the secondary dehumidification box 22. The first temperature sensor 213 is used to detect the temperature of the high-pressure natural gas at different locations within the primary dehumidification box 21, thereby facilitating the operator to adjust the valve opening of each first flow control valve 214 based on the detected temperature value.

[0048] A second temperature sensor 222 is provided above each circulation coil 221 in the secondary dehumidification box 22 to detect the temperature of the high-pressure natural gas at different positions in the secondary dehumidification box 22, so that the staff can adjust the valve opening of each second flow control valve 223 according to the detected temperature value.

[0049] The water buffer tank 3 is a sealed container used to receive and temporarily store condensed water from the primary dehumidification tank 21 and the secondary dehumidification tank 22. The pressure inside the water buffer tank 3 is much lower than the pressure inside the primary dehumidification tank 21 or the secondary dehumidification tank 22. Furthermore, the water buffer tank 3 is installed at a lower height than the primary and secondary dehumidification tanks 21, 22, allowing the condensed water to flow smoothly into the water buffer tank 3 under the influence of air pressure and gravity.

[0050] A third liquid level sensor 33 is located in the middle of the water buffer tank 3, a pressure sensor 34 is located at the top of the water buffer tank 3, and a drain valve 31 is located at the bottom of the water buffer tank 3. Due to the high pressure inside the primary dehumidification tank 21 and the secondary dehumidification tank 22, a small amount of natural gas is inevitably discharged into the water buffer tank 3 while receiving condensed water, causing a small increase in pressure inside the water buffer tank 3.

[0051] When the third liquid level sensor 33 detects that the liquid level exceeds the set value, the drain valve 31 opens for a certain period of time to allow part of the condensed water to be discharged from the water storage buffer tank 3 through the opened drain valve 31. At the same time, there is still enough condensed water at the bottom of the water storage buffer tank 3 to prevent the natural gas in the water storage buffer tank 3 from leaking.

[0052] The top of the water buffer tank 3 is connected to the natural gas safety venting system via a pipeline. A vent valve 32 is installed on the pipeline connecting the water buffer tank 3 and the safety venting system. When the pressure sensor 34 detects that the pressure in the water buffer tank 3 has risen to a set value, the vent valve 32 opens, allowing the natural gas discharged into the water buffer tank 3 to enter the natural gas safety venting system for venting, thus preventing the pressure in the water buffer tank 3 from continuing to rise.

[0053] The implementation principle of the above embodiment is:

[0054] After passing through the flow meter 13 from the air inlet pipe 11, the high-pressure natural gas enters the first-stage dehumidification box 21 and the second-stage dehumidification box 22 in turn. The staff adjusts the first flow control valve 214 and the second flow control valve 223 according to the flow rate of the high-pressure natural gas displayed by the flow meter 13 and the temperature values ​​displayed by the first temperature sensor 213 and the second temperature sensor 222. The high-pressure natural gas and the mixed water vapor are in contact with the cold energy release plate 211 and the circulation coil 221 at the same time for heat exchange. During the heat exchange process, only the water vapor is cooled and liquefied into droplets that adhere to the cold energy release plate 211 and the circulation coil 221, and drips to the bottom of the dehumidification box under the action of gravity. When the liquid level of the condensed water at the bottom of the first-stage dehumidification box 21 or the second-stage dehumidification box 22 reaches the set value, the drainage control valve on the corresponding pipeline opens, and the condensed water is discharged into the water storage buffer tank 3 along the pipeline, thereby achieving effective dehumidification of the high-pressure natural gas.

[0055] Example 2

[0056] As attached Figure 3 FIG. 1 shows a natural gas cooling dehumidification system disclosed in the present invention. Unlike the first embodiment, the system further includes a controller. Furthermore, all first temperature sensors 213, second temperature sensors 222, first liquid level sensors 215, second liquid level sensors 224, third liquid level sensors 33, pressure sensors 34, and flowmeter 13 in the first embodiment are electrically connected to the controller. The controller receives electrical signals from the aforementioned sensors and flowmeter 13 and controls the opening levels of all first flow control valves 214, second flow control valves 223, first drain control valves 216, second drain control valves 225, drain valves 31, and exhaust valves 32 according to preset parameters and control logic. This allows for more timely and precise regulation of the natural gas cooling dehumidification system, resulting in superior dehydration performance and automated operation of the dehumidification system.

[0057] Although preferred embodiments of the present invention have been described, those skilled in the art may make additional changes and modifications to these embodiments once they are aware of the basic inventive concepts. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention. Clearly, those skilled in the art may make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, to the extent such changes and modifications fall within the scope of the claims and their equivalents, the present invention is intended to encompass such changes and modifications.

Claims

1. A natural gas cooling dehumidification system connected to a high-pressure natural gas pipeline (1), characterized in that: The invention comprises a dehumidification structure (2) and a water buffer tank (3), wherein a flow meter (13) is provided on an air inlet pipe (11) of the high-pressure natural gas pipeline (1), the dehumidification structure (2) comprises a dehumidification box body connected to the high-pressure natural gas pipeline (1), a heat exchange pipeline is provided in the dehumidification box body, low-temperature flash gas flows in the heat exchange pipeline, and a flow control valve for controlling the flow of low-temperature flash gas is provided on the heat exchange pipeline, the bottom of the dehumidification box body is connected to the water buffer tank (3) through a pipeline, a drainage control valve is provided on the pipeline connecting the dehumidification box body and the water buffer tank (3), a drainage valve (31) is provided on the bottom of the water buffer tank (3), the top of the water buffer tank (3) is connected to a safety venting system through a pipeline, and an exhaust valve (32) is provided on the pipeline connecting the water buffer tank (3) and the safety venting system.

2. The natural gas cold energy dehumidification system according to claim 1, characterized in that: The dehumidification box includes a first-stage dehumidification box (21), wherein a plurality of cold energy release plates (211) whose height is lower than that of the first-stage dehumidification box (21) are arranged in the first-stage dehumidification box (21), and all the cold energy release plates (211) are alternately fixed to the top and bottom of the first-stage dehumidification box (21) so that high-pressure natural gas is continuously turned in the first-stage dehumidification box (21), and low-temperature flash gas flows in the cold energy release plates (211).

3. The natural gas cold energy dehumidification system according to claim 2, characterized in that: Each of the cold energy release plates (211) is independently connected to a main pipeline of low-temperature flash gas, and a first flow control valve (214) is provided on the pipeline connecting each of the cold energy release plates (211) and the main pipeline of low-temperature flash gas.

4. The natural gas cold energy dehumidification system according to claim 2, characterized in that: The air inlet pipe (11) of the high-pressure natural gas pipeline (1) is located at the top of the first-stage dehumidification box (21), and the end of the air inlet pipe (11) is provided with an air inlet (14) opening vertically downward.

5. The natural gas cold energy dehumidification system according to claim 2, characterized in that: The dehumidification box further comprises a secondary dehumidification box (22), the position of the secondary dehumidification box (22) being higher than the primary dehumidification box (21), and the top of the primary dehumidification box (21) being in communication with the side wall of the bottom of the secondary dehumidification box (22).

6. The natural gas cold energy dehumidification system according to claim 5, characterized in that: A plurality of circulation coils (221) are provided in the secondary dehumidification box (22), and all the circulation coils (221) are arranged at intervals in the height direction of the secondary dehumidification box (22), and low-temperature flash gas flows in the circulation coils (221).

7. The natural gas cold energy dehumidification system according to claim 6, characterized in that: Each of the circulation coils (221) is arranged to form a grid structure, each of the circulation coils (221) is independently connected to a main pipeline of low-temperature flash gas, and a second flow control valve (223) is provided on the pipeline connecting each of the circulation coils (221) and the main pipeline of low-temperature flash gas.

8. The natural gas cold energy dehumidification system according to claim 6, characterized in that: A first temperature sensor (213) is provided at the connection point between the first-stage dehumidification box (21) and the high-pressure natural gas pipeline (1), and at the connection point between the first-stage dehumidification box (21) and the second-stage dehumidification box (22). The first temperature sensor (213) is used to detect the temperature of the high-pressure natural gas at different positions in the first-stage dehumidification box (21). A second temperature sensor (222) is provided above each of the circulation coils (221) in the second-stage dehumidification box (22) to detect the temperature of the high-pressure natural gas at different positions in the second-stage dehumidification box (22).

9. The natural gas cold energy dehumidification system according to claim 8, characterized in that: A first liquid level sensor (215) and a second liquid level sensor (224) are respectively provided at the bottom of the primary dehumidification box (21) and the secondary dehumidification box (22). The first liquid level sensor (215) and the second liquid level sensor (224) are respectively used to detect the water levels in the primary dehumidification box (21) and the secondary dehumidification box (22).

10. The natural gas cold energy dehumidification system according to claim 9, characterized in that: The water storage buffer tank (3) is also provided with a third liquid level sensor (33) and a pressure sensor (34). The controller is electrically connected to the flow meter (13), the first temperature sensor (213), the second temperature sensor (222), the first liquid level sensor (215), the second liquid level sensor (224), the third liquid level sensor (33) and the pressure sensor (34) and receives electrical signals therefrom. The controller controls the opening degrees of all the first flow control valve (214), the second flow control valve (223), the first drainage control valve (216), the second drainage control valve (225), the drainage valve (31) and the exhaust valve (32).

Images