A natural gas pipeline antifreeze device and method based on pressure energy heat release

Abstract

A natural gas pipeline antifreeze device and method based on pressure energy heat release, the device is composed of a natural gas inlet pipeline, a separation device, a heat exchanger, a shell, a hot end pipeline, a vortex tube, a cold end pipeline, a water vapor collection device, a buffer tank, a gradually diverging nozzle and a natural gas outlet pipeline; the device is placed on an open ground, and natural gas is introduced from the inlet pipeline. Through the high pressure energy of natural gas and the hot and cold separation effect of the vortex tube, the hot and cold end airflows are comprehensively utilized. The present invention uses the pressure energy of natural gas as the input energy, and uses the pressure energy conversion method to increase the temperature of the natural gas itself. Compared with the traditional natural gas pipeline antifreeze method, it realizes lower cost and more efficient natural gas pipeline antifreeze, reduces the space occupied by equipment, and saves materials.

Description

Technical Field

[0001] The present invention relates to the technical field of natural gas pipeline anti-freezing and anti-blocking, and in particular to a natural gas pipeline anti-freezing device and method based on pressure energy heat release. Background Art

[0002] In the process of energy structure transformation, natural gas will play an important bridging role. Promoting the growth of natural gas consumption and industrial development is the only way for China to build a clean energy system. Therefore, in order to meet the demand for incremental clean energy in economic and social development and promote the replacement of traditional high-burning fossil energy, we should focus on the upgrading and optimization of natural gas infrastructure.

[0003] In the process of natural gas extraction and utilization, moisture is the main interference in natural gas engineering. Excessive water content in the use and transportation of natural gas will cause many adverse consequences, especially the freezing and blockage of natural gas pipelines in winter, which is an important bottleneck for maintaining the quantity and increasing the efficiency of natural gas production.

[0004] In the traditional production process, the antifreeze plugging technology for natural gas pipelines is divided into two categories: "dehydration antifreeze technology" and "hydrate formation inhibition technology". Although conventional natural gas dehydration technology is conducive to eliminating the adverse effects of water on the project, various means have certain shortcomings, and the economic or operational advantages in large-scale gas transmission projects are not obvious. The antifreeze effect of hydrate formation inhibition technology is limited, and it does not fundamentally solve the problem of natural gas water content including pipeline corrosion. It is more suitable as an auxiliary means to improve the antifreeze performance of pipelines. Summary of the invention

[0005] In order to overcome the problems existing in the prior art, the purpose of the present invention is to provide a natural gas pipeline antifreeze device and method based on pressure energy heat release, which utilizes the high-pressure natural gas in the gas well to heat the natural gas by separating (releasing) the heat through the vortex tube, thereby preventing the formation of natural gas hydrates at the wellhead due to throttling and pressure regulation, thereby avoiding pipeline freezing and blockage, and achieving lower cost and more efficient natural gas pipeline antifreeze.

[0006] In order to achieve the above object, the technical solution adopted by the present invention is:

[0007] A natural gas pipeline antifreeze device based on pressure energy heat release, the device comprises a natural gas inlet pipeline 1, a separation device 2, a heat exchanger 3, a shell 4, a hot end pipeline 5, a vortex tube 6, a cold end pipeline 7, a water vapor collection device 8, a buffer tank 9, a gradually diverging nozzle 10 and a natural gas outlet pipeline 11;

[0008] The natural gas inlet pipeline 1 is located above the device, one end of which is connected to the gas well, and the other end is connected to one end of the separation device 2; the separation device 2 is a curved pipe structure, and the natural gas is separated in the curved pipe due to the centrifugal force, and the separated water flows out from the small holes on the outside of the curved pipe and is collected in the water vapor collection device 8 below the separation device, and the other end of the separation device 2 is connected to the heat exchanger 3; the heat exchanger 3 is arranged at the gas inlet position above the vortex tube 6, and the inlet airflow pipeline of the vortex tube 6 passes through the upper and lower sides of the heat exchanger 3, and the hot end pipeline 5 passes through the heat exchanger 3; the vortex tube 6 below the heat exchanger 3 has There are two outlets, one outlet is the hot end air flow outlet connected to the hot end pipe 5, and the hot end pipe 5 is connected to the buffer tank 9 after passing through the heat exchanger 3; the other outlet of the vortex tube 6 is the cold end air flow outlet connected to the cold end pipe 7, and the cold end pipe 7 is connected to the buffer tank 9 after passing through the water vapor collection device 8; the inlet of the buffer tank 9 is connected to the hot end pipe 5 and the cold end pipe 7, and the outlet of the buffer tank 9 is connected to one end of the gradually divergent nozzle 10 through the outflow pipe; the other end of the gradually divergent nozzle 10 is connected to one end of the natural gas outlet pipe 11; the other end of the natural gas outlet pipe 11 is connected to the downstream processing plant; the shell 4 wraps the entire device.

[0009] The heat exchanger 3 is an air-to-air heat exchanger, through which the vortex tube inlet airflow pipe and the hot end pipe 5 pass, so that the heat of the hot end pipe 5 is transferred to the vortex tube inlet airflow pipe, so that the inlet airflow temperature is increased to prevent the pipe from freezing.

[0010] The vortex tube 6 is a cold and hot separation device. The high-pressure air is accelerated and expanded in the vortex tube 6, which can instantly split the high-pressure air into two cold and hot air flows. The cold end air flow flows into the cold end pipe 7, and the hot end air flow flows into the hot end pipe 5.

[0011] The water vapor collecting device 8 is used to collect the water contained in the natural gas separated by the separation device 2. Since the natural gas contains sulfide impurities, the water in the natural gas contains sulfate, mainly sodium sulfate. Therefore, by passing the cold end pipeline 7 through the water vapor collecting device 8, the temperature is reduced, and the sodium sulfate will precipitate in the form of crystals in a low temperature environment. At the same time, two outlets are left in the water vapor collecting device 8, namely a liquid outlet and a crystal outlet.

[0012] The natural gas in the hot end pipeline 5 and the cold end pipeline 7 is introduced into the buffer tank 9 at the downstream, and then merged into a uniform airflow, and then passes through the gradually diverging nozzle 10 to decelerate and pressurize the natural gas in the pipeline to restore part of the pressure energy of the natural gas.

[0013] When working, the device is placed on open ground, and then the high-pressure natural gas from the gas well flows in from the natural gas inlet pipeline 1, and then passes through the separation device 2, and the water in the natural gas is separated on the outer wall of the curved pipe, and the water is collected in the water vapor collection device 8, and then the natural gas flows into the vortex tube 6 and is separated into two cold and hot air flows. The hot end air flow flows into the hot end pipeline 5, and the hot air flow in the hot end pipeline 5 simultaneously passes through the heat exchanger 3 to use part of the heat to heat the vortex tube inlet air flow; the cold end air flow flows into the cold end pipeline 7, and the cold air flow in the cold end pipeline 7 passes through the water vapor collection device 8; then the two cold and hot air flows are passed into the buffer tank 9 and merged into one air flow, which passes through the gradually diverging nozzle 10, and then flows to the downstream processing plant through the natural gas outlet pipeline 11, so as to realize efficient and low-cost heating of the natural gas.

[0014] Compared with the prior art, the present invention has the following advantages:

[0015] The present invention utilizes high-pressure natural gas from a gas well, and divides the high-pressure natural gas into two cold and hot air flows through a vortex tube, and the cold and hot air flows are comprehensively utilized; the air flow at the hot end is introduced into the heat exchanger 3 to heat the air flow at the inlet of the vortex tube, thereby preventing the inlet pipeline from freezing; since the natural gas contains moisture, and the moisture contains sulfate, such as sodium sulfate, the air flow at the cold end of the vortex tube can be used to perform low-temperature crystallization of the aqueous solution to precipitate sodium sulfate crystals; after the cold and hot end air flows merge, the natural gas is decelerated and pressurized through a gradually expanding nozzle to restore a certain pressure, thereby achieving lower cost and more efficient natural gas pipeline antifreeze compared to traditional natural gas antifreeze methods, and reducing the space occupied by equipment and saving materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 The diagram is a schematic diagram of a natural gas pipeline antifreeze device based on pressure energy heat release according to the present invention. DETAILED DESCRIPTION

[0017] The present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0018] like Figure 1 As shown, the present invention is a natural gas pipeline antifreeze device based on pressure energy heat release, the device is composed of a natural gas inlet pipeline 1, a separation device 2, a heat exchanger 3, a shell 4, a hot end pipeline 5, a vortex tube 6, a cold end pipeline 7, a water vapor collection device 8, a buffer tank 9, a gradually diverging nozzle 10 and a natural gas outlet pipeline 11;

[0019] The natural gas inlet pipeline 1 is located at the upper left of the device, one end of which is connected to the gas well and the other end is connected to the separation device 2; the separation device 2 is a curved pipe structure, and the natural gas is separated in the curved pipe due to the centrifugal force, and the separated water flows out from the small holes on the outside of the curved pipe and is collected in the water vapor collection device 8 below the separation device, and the right end of the separation device 2 is connected to the heat exchanger 3; the heat exchanger 3 is arranged at the gas inlet position above the vortex tube 6, and the inlet airflow pipeline of the vortex tube 6 passes through the upper and lower sides of the heat exchanger 3, and the hot end pipeline 5 passes through the heat exchanger 3 from right to left; the vortex tube 6 below the heat exchanger 3 has two left and right outlets, and the right end outlet is The hot end air flow outlet is connected to the hot end pipeline 5. After the hot end pipeline 5 passes through the heat exchanger 3, its left end is connected to the buffer tank 9; the left end outlet of the vortex tube 6 is the cold end air flow outlet and is connected to the cold end pipeline 7. The cold end pipeline 7 passes through the water vapor collection device 8 from left to right, and then the left end of the cold end pipeline 7 is connected to the buffer tank 9; the buffer tank 9 is located at the lower left corner of the device, connected to the hot end pipeline 5 and the cold end pipeline 7, and connected to the right end of the gradually divergent nozzle 10 through the outflow pipeline at the right end; the left end of the gradually divergent nozzle 10 is connected to the right end of the natural gas outlet pipeline 11; the left end of the natural gas outlet pipeline 11 is connected to the downstream processing plant; the shell 4 wraps the entire device.

[0020] Example: Heating and anti-freezing of wellhead natural gas pipeline:

[0021] (1) Figure 1 As shown, the antifreeze device of the present invention is placed on an open ground, and then the high-pressure natural gas from the gas well flows in from the natural gas inlet pipeline 1, and then passes through the separation device 2, and the water in the natural gas is separated on the outer wall of the elbow, and the water is collected in the water vapor collection device 8, and then the natural gas flows into the vortex tube 6;

[0022] (2) Figure 1 As shown, the natural gas in the vortex tube 6 is separated into two streams, hot and cold. The hot end stream is located on the right side and flows into the hot end pipe 5. The hot stream in the hot end pipe 5 passes through the heat exchanger 3 and uses part of the heat to heat the vortex tube inlet stream. The cold end stream is located on the left side and flows into the cold end pipe 7. The cold stream in the cold end pipe 7 passes through the water vapor collection device 8.

[0023] (3) Figure 1 As shown, the two cold and hot air flows are then introduced into the buffer tank 9 and merged into one air flow, which passes through the divergent nozzle 10 and then flows to the downstream processing plant through the natural gas outlet pipeline 11, thereby achieving efficient and low-cost heating of the natural gas.

Claims

1. A natural gas pipeline antifreeze device based on pressure energy heat release, characterized in that: The device is composed of a natural gas inlet pipeline (1), a separation device (2), a heat exchanger (3), a shell (4), a hot end pipeline (5), a vortex tube (6), a cold end pipeline (7), a water vapor collection device (8), a buffer tank (9), a gradually diverging nozzle (10) and a natural gas outlet pipeline (11); The natural gas inlet pipeline (1) is located above the device, one end of which is connected to the gas well and the other end of which is connected to one end of the separation device (2); the separation device (2) is a curved pipe structure, and the natural gas is separated in the curved pipe due to the centrifugal force, and the separated water flows out from the small holes on the outside of the curved pipe and is collected in the water vapor collection device (8) below the separation device, and the other end of the separation device (2) is connected to the heat exchanger (3); the heat exchanger (3) is arranged at the gas inlet position above the vortex tube (6), the inlet airflow pipeline of the vortex tube (6) passes through the upper and lower sides of the heat exchanger (3), and the hot end pipeline (5) passes through the heat exchanger (3); the vortex tube (6) below the heat exchanger (3) has two outlets , one outlet is the hot end air flow outlet connected to the hot end pipeline (5), and the hot end pipeline (5) is connected to the buffer tank (9) after passing through the heat exchanger (3); the other outlet of the vortex tube (6) is the cold end air flow outlet connected to the cold end pipeline (7), and the cold end pipeline (7) is connected to the buffer tank (9) after passing through the water vapor collection device (8); the inlet of the buffer tank (9) is connected to the hot end pipeline (5) and the cold end pipeline (7), and the outlet of the buffer tank (9) is connected to one end of the gradually diverging nozzle (10) through the outflow pipeline; the other end of the gradually diverging nozzle (10) is connected to one end of the natural gas outlet pipeline (11); the other end of the natural gas outlet pipeline (11) is connected to the downstream processing plant; the shell (4) wraps the entire device.

2. A natural gas pipeline antifreeze device based on pressure energy heat release according to claim 1, characterized in that: The heat exchanger (3) is an air-to-air heat exchanger, through which the vortex tube inlet airflow pipeline and the hot end pipeline (5) pass, so that the heat of the hot end pipeline (5) is transferred to the vortex tube inlet airflow pipeline, so that the inlet airflow temperature is increased, thereby preventing the pipeline from freezing.

3. A natural gas pipeline antifreeze device based on pressure energy heat release according to claim 1, characterized in that: The vortex tube (6) is a cold and hot separation device. The high-pressure air is accelerated and expanded in the vortex tube (6), and can be instantly split into two cold and hot air flows. The cold end air flow flows into the cold end pipe (7), and the hot end air flow flows into the hot end pipe (5).

4. A natural gas pipeline antifreeze device based on pressure energy heat release according to claim 1, characterized in that: The water vapor collecting device (8) is used to collect the water contained in the natural gas separated by the separation device (2). Since the natural gas contains sulfide impurities, the water in the natural gas contains sulfate, mainly sodium sulfate. Therefore, by passing the cold end pipe (7) through the water vapor collecting device (8), the temperature is reduced, and the sodium sulfate will precipitate in the form of crystals in a low temperature environment. At the same time, two outlets are left in the water vapor collecting device (8), namely a liquid outlet and a crystal outlet.

5. A natural gas pipeline antifreeze device based on pressure energy heat release according to claim 1, characterized in that: The natural gas in the hot end pipeline (5) and the cold end pipeline (7) is introduced into the buffer tank (9) at the downstream, and then merged into a uniform airflow, which then passes through the gradually diverging nozzle (10) to decelerate and pressurize the natural gas in the pipeline, thereby recovering part of the pressure energy of the natural gas.

6. A working method of a natural gas pipeline antifreeze device based on pressure energy heat release according to any one of claims 1 to 5, characterized in that: The following steps are involved: Step 1, placing the antifreeze device on an open ground, then letting high-pressure natural gas from a gas well flow in from a natural gas inlet pipeline (1), and then passing through a separation device (2), separating water from the natural gas on the outer wall of the curved pipe, and collecting the water in a water vapor collection device (8), and then the natural gas flows into a vortex tube (6); Step 2, the natural gas in the vortex tube (6) is separated into two air flows, hot and cold. The hot end air flow flows into the hot end pipeline (5), and the hot air flow in the hot end pipeline (5) passes through the heat exchanger (3) to use part of the heat to heat the air flow at the inlet of the vortex tube; the cold end air flow flows into the cold end pipeline (7), and the cold air flow in the cold end pipeline (7) passes through the water vapor collection device (8); Step 3, the two cold and hot air flows are then introduced into the buffer tank (9) and merged into one air flow, which passes through the divergent nozzle (10) and then flows to the downstream processing plant through the natural gas outlet pipeline (11), thereby achieving efficient and low-cost heating of the natural gas.

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