A natural gas supply system

Abstract

The application discloses a natural gas supply system, which solves the technical problem of poor stability of the prior art natural gas supply system. The natural gas supply system comprises a user, a first supply pipeline, a second supply pipeline, a third supply pipeline, a main pipeline and a controller. The first supply pipeline comprises a collecting structure and a first valve, the collecting structure is used for collecting oilfield associated gas, and the collecting structure and the first valve are sequentially connected in series. The second supply pipeline comprises a pipeline and a second valve which are sequentially connected in communication, and the pipeline is communicated with a municipal natural gas pipe network. The third supply pipeline comprises a storage tank and a third valve which are sequentially connected in series. The main pipeline is provided with a pressure gauge, an input end of the main pipeline is communicated with output ends of the first supply pipeline, the second supply pipeline and the third supply pipeline, and an output end of the main pipeline is communicated with the user. The natural gas supply system provided by the application can provide stable natural gas and reduce the production and operation cost of a steel enterprise.

Description

Technical Field

[0001] This application belongs to the field of natural gas supply technology, specifically relating to a natural gas supply system. Background Technology

[0002] The main processes of steel plants, such as slab heating, slab cutting, and sintering of sintered materials, all require the use of natural gas. In related technologies, most steel plants mainly obtain natural gas from external municipal pipelines, which are then delivered to each gas-using unit after pressure regulation. Some steel plants in remote suburbs do not have municipal pipeline natural gas resources and use purchased liquefied petroleum gas (LNG) to deliver it to each gas-using unit.

[0003] Because steel plants operate on a continuous production basis, a single gas source, whether municipal pipeline natural gas or liquefied petroleum gas, cannot guarantee a stable long-term supply. Summary of the Invention

[0004] To address the technical problem of low stability in natural gas supply within steel plants, this application provides a natural gas supply system.

[0005] This application provides a natural gas supply system, including: user; The first supply pipeline includes a collection structure and a first valve. The collection structure is used to collect associated gas from the oilfield. The collection structure and the first valve are connected in series. The second supply pipeline includes a pipe connected in sequence and a second valve, wherein the pipe is connected to the municipal natural gas pipeline network; The third supply pipeline includes a storage tank and a third valve connected in series, wherein the storage tank is used to store liquefied natural gas; The main pipeline is equipped with a pressure gauge for detecting the gas pressure inside the main pipeline. The input end of the main pipeline is connected to the output ends of the first supply pipeline, the second supply pipeline, and the third supply pipeline. The output end of the main pipeline is connected to the user. The controller is electrically connected to the pressure gauge, the first valve, the second valve, and the third valve.

[0006] In some embodiments, the first supply line further includes a shut-off valve and a bypass line connected in parallel to the shut-off valve, the shut-off valve being connected in series between the collecting structure and the first valve; The bypass pipeline is equipped with a filter and bypass valves located at the input and output ends of the filter, respectively.

[0007] In some embodiments, the first supply line further includes a compressor connected in series between the shut-off valve and the first valve; The input end of the compressor is connected to the output end of the bypass pipeline.

[0008] In some embodiments, the first supply line further includes a first flow meter connected in series between the compressor and the first valve.

[0009] In some embodiments, the second supply line further includes a second flow meter disposed in the pipeline.

[0010] In some embodiments, the third supply line further includes a vaporizer connected in series between the storage tank and the third valve.

[0011] In some embodiments, the vaporizer is a water bath vaporizer.

[0012] In some embodiments, the third supply line further includes a heat exchanger; The heat exchanger is provided with a water channel and a gas channel. The outlet of the water channel is connected to the inlet of the water bath vaporizer, and the inlet of the gas channel is connected to the sintering flue gas collection structure.

[0013] In some embodiments, the third supply line further includes a third flow meter located between the vaporizer and the third valve. In some embodiments, the third supply line further includes a pressure regulating valve located between the vaporizer and the third valve.

[0014] The natural gas supply system provided according to the embodiments of this application includes a user, a first supply pipeline, a second supply pipeline, a third supply pipeline, a main pipeline, and a controller. The first supply pipeline includes a collection structure and a first valve. The collection structure is used to collect associated gas from oil fields, and the collection structure and the first valve are connected in series. The second supply pipeline includes a pipe connected in series and a second valve. The pipe is connected to the municipal natural gas pipeline network. The third supply pipeline includes a storage tank connected in series and a third valve. The main pipeline is equipped with a pressure gauge. The input end of the main pipeline is connected to the output ends of the first, second, and third supply pipelines, and the output end of the main pipeline is connected to the user. The controller is electrically connected to the pressure gauge, the first valve, the second valve, and the third valve.

[0015] This application, taking into account the resource characteristics of the region, realizes the recovery and utilization of associated gas from flared oilfields, creates an LNG reserve gas source, introduces municipal natural gas, and sets up three gas sources in parallel. It automatically adjusts and replenishes according to the needs of downstream users, forming a three-in-one natural gas security supply guarantee system, ensuring the continuous, safe and stable operation of the steel plant; at the same time, it can give priority to using low-priced associated gas from oilfields as a gas source, reducing the production and operating costs of steel enterprises. Attached Figure Description

[0016] Figure 1 A schematic diagram of the natural gas supply system of this application is shown.

[0017] Explanation of reference numerals in the attached figures: 10-First supply pipeline, 11-Collection structure, 12-Stop valve, 13-Filter, 14-Bypass valve, 15-Compressor, 16-First flow meter, 17-First valve; 20 - Second supply pipeline; 21 - Second valve; 22 - Second flow meter; 30-Third supply pipeline, 31-Storage tank, 32-Vaporizer, 33-Pressure regulating valve, 35-Third valve; 40 - Main pipe, 41 - Pressure gauge.

[0018] 51-Slab cutting machine, 52-Sintering material surface blowing device. Detailed Implementation

[0019] To enable those skilled in the art to more clearly understand this application, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0020] This application provides a natural gas supply system that uses at least one of three gas sources to supply natural gas to users, thereby improving the stability of natural gas supply and realizing the recovery of associated gas from oil fields.

[0021] This application is described below with reference to the accompanying drawings and specific embodiments: Please see Figure 1 The natural gas supply system provided in this application includes a user, a first supply pipeline 10, a second supply pipeline 20, a third supply pipeline 30, a main pipeline 40, and a controller. The first supply pipeline 10 includes a collection structure 11 and a first valve 17. The collection structure 11 is used to collect associated gas from the oil field, and the collection structure 11 and the first valve 17 are connected in series. The second supply pipeline 20 includes a pipeline connected in series and a second valve 21. The pipeline is connected to the municipal natural gas pipeline network. The third supply pipeline 30 includes a storage tank 31 connected in series and a third valve 35. The main pipeline 40 is equipped with a pressure gauge 41. The input end of the main pipeline 40 is connected to the output ends of the first supply pipeline 10, the second supply pipeline 20, and the third supply pipeline 30, and the output end of the main pipeline 40 is connected to the user. The controller is electrically connected to the pressure gauge 41, the first valve 17, the second valve 21, and the third valve 35.

[0022] In a steel plant, the user can have at least one of a slab cutting machine 51, a heating furnace, and a sintering material blowing device 52. The slab cutting machine 51 uses natural gas combustion to generate a high-temperature flame to cut the slab. The heating furnace uses the heat generated by natural gas combustion to heat the slabs inside. The sintering material blowing device 52 can blow natural gas onto the sintering material to achieve sintering.

[0023] The first supply pipeline 10 is for transporting associated gas from the oilfield. Associated gas refers to natural gas released into the atmosphere along with crude oil production during oilfield extraction. Typically, after gas-liquid separation, some associated gas with unstable pressure and low calorific value is directly discharged into the atmosphere through the vent pipe. Since associated gas contains flammable gases, direct release may pose safety hazards; therefore, in some cases, it is treated by flaring. For steel companies located near oilfields, the associated gas can be collected by the collection structure 11 and then delivered to users through the first valve 17 and the main pipeline 40, thus achieving the recovery and utilization of associated gas.

[0024] The second supply pipeline 20 is a natural gas transmission pipeline of the municipal pipeline network. Natural gas can be delivered to users through the pipeline, the second valve 21, and the main pipeline 40. The third supply pipeline 30 is a liquefied natural gas transmission pipeline. Natural gas in the storage tank 31 can be delivered to users through the third valve 35 and the main pipeline 40.

[0025] The controller is electrically connected to pressure gauge 41, first valve 17, second valve 21, and third valve 35. Therefore, the controller can receive the pressure value detected by pressure gauge 41 and control the opening of first valve 17, second valve 21, and third valve 35. Normally, first valve 17 is fully open, using associated gas from the oilfield as fuel. When the user's fuel consumption increases, and the pressure value is higher than the first set value but lower than the second set value, the controller controls the opening of second valve 21, increasing its opening. When second valve 21 is fully open and the pressure value is not higher than the first set value, the controller instructs third valve 35 to open its opening further. This system, combined with the regional resource characteristics, enables the recovery and utilization of released associated gas from the oilfield, creating an LNG backup gas source. It also introduces municipal natural gas, with three gas sources connected in parallel. The system automatically adjusts and replenishes according to the needs of downstream users, forming a three-in-one natural gas security supply guarantee system, ensuring the continuous, safe, and stable operation of the steel plant. Simultaneously, it prioritizes the use of low-priced gas sources, reducing the production and operating costs of the steel company.

[0026] Taking the first and second setpoints of 5.5 kg / cm² and 5.7 kg / cm² as examples, when the user's fuel consumption is low, the gas pressure in the main pipeline 40 is greater than 5.7 kg / cm², and opening only the first valve 17 is sufficient to meet the user's fuel needs with associated gas from the oilfield. When the user's fuel consumption increases, the gas pressure in the main pipeline 40 decreases to 5.6 kg / cm², at which point the controller opens the second valve 21, allowing both associated gas from the oilfield and municipal natural gas to supply fuel to the user. When the user's fuel consumption is very high, the gas pressure in the main pipeline 40 falls below 5.5 kg / cm², at which point the controller opens the third valve 35, allowing all three—associated gas from the oilfield, municipal natural gas, and liquefied natural gas—to supply fuel to the user. When the user's demand decreases, the gas pressure in the main pipeline 40 rises to 5.6 kg / cm², at which point the controller closes the third valve 35, allowing both associated gas from the oilfield and municipal natural gas to supply fuel to the user. As user demand continues to decrease, the gas pressure in the main pipeline 40 rises to 5.7 kg / cm2, and the controller closes the second valve 21, requiring only associated gas from the oilfield to supply fuel to the user.

[0027] Of course, in the event of fluctuations in associated gas supply from the oilfield, the user can utilize at least one of the following gas sources: municipal natural gas or liquefied natural gas (LNG). During periods of scarcity in the municipal natural gas supply during cold winters or when the municipal supply line experiences a failure, the second valve 21 can be closed, and the opening and closing of the first valve 17 and the third valve 35 can be controlled, allowing the user to use at least one of the following gas sources: associated gas from the oilfield or LNG. In the event of a failure in the third supply pipeline 30, the third valve 35 can be closed, and the opening and closing of the first valve 17 and the second valve 21 can be controlled, allowing the user to use at least one of the following gas sources: associated gas from the oilfield or municipal natural gas. This ensures that even if one gas source experiences fluctuations or a failure, another one or two sources can be selected, guaranteeing a long-term stable supply of natural gas to the user and improving production stability.

[0028] The first supply pipeline 10 is a pipeline for transporting associated gas from the oilfield. The collection mechanism can be a gas collecting hood or a gas collecting pipe, etc. In some embodiments, the first supply pipeline 10 also includes a shut-off valve 12 and a bypass pipeline connected in parallel to the shut-off valve 12. The shut-off valve 12 is connected in series between the collection structure 11 and the first valve 17. The bypass pipeline is equipped with a filter 13 and bypass valves 14 located at the input and output ends of the filter 13, respectively. The associated gas from the oilfield may contain impurities. If there are many impurities in the associated gas, the shut-off valve 12 can be closed and the bypass valve 14 opened, allowing the associated gas to flow through the filter 13 to filter out impurities and improve the purity of the associated gas. If the associated gas is relatively clean, the bypass valve 14 is closed and the shut-off valve 12 is open, allowing the associated gas to bypass the filter 13 and reducing the flow path.

[0029] In some embodiments, the first supply pipeline 10 further includes a compressor 15, which is connected in series between the shut-off valve 12 and the first valve 17; the input end of the compressor 15 is connected to the output end of the bypass pipeline. Pressurizing associated gas from the oilfield can meet the pressure requirements of downstream users. The compressor 15 is a gas compressor, a device that can increase the pressure of low-pressure gas to a higher pressure. Based on the fundamental laws of gas dynamics, the gas compressor 15 increases pressure by compressing gas.

[0030] In some embodiments, the first supply line 10 further includes a first flow meter 16 connected in series between the compressor 15 and the first valve 17. The first flow meter 16 monitors the gas flow rate within the first supply line 10 to meet the flow requirements of downstream users.

[0031] The second supply pipeline 20 is a municipal natural gas transmission pipeline. The second supply pipeline 20 also includes a second flow meter 22 installed in the pipeline to monitor the gas flow rate in the second supply pipeline 20 in order to meet the flow demand of downstream users.

[0032] The third supply pipeline 30 is a pipeline for transporting liquefied natural gas. The third supply pipeline 30 also includes a vaporizer 32 connected in series between the storage tank 31 and the third valve 35. The natural gas in the storage tank 31 is liquid, and the vaporizer 32 can vaporize the liquefied natural gas into a gaseous state for downstream users to burn and use.

[0033] In some embodiments, the vaporizer 32 can be a water bath vaporizer 32, which vaporizes liquefied natural gas using hot water. In other embodiments, the vaporizer 32 can also be an ambient air vaporizer 32, which vaporizes liquefied natural gas using air.

[0034] When the vaporizer 32 is a water bath vaporizer, the third supply pipeline 30 may also include a heat exchanger. The heat exchanger has a water channel and a gas channel. The outlet of the water channel is connected to the inlet of the water bath vaporizer 32, and the inlet of the gas channel is connected to the sintering flue gas collection structure 11. Because the gas channel is connected to the sintering flue gas collection structure 11, the flue gas generated during sintering can flow into the gas channel. The flue gas in the gas channel can exchange heat with the circulating water in the water channel. The outlet of the water channel is connected to the inlet of the water bath vaporizer 32, so the heated circulating water can enter the water bath vaporizer 32 to exchange heat with the liquefied gas, thus achieving the vaporization of the liquefied gas. The heat exchanger enables the recovery and utilization of heat from the sintering flue gas, transferring the heat to the liquefied gas. The vaporized natural gas can then be used as fuel for sintering, thus achieving a cycle. The flue gas collection structure 11 is a common structure in the sintering process. In specific implementation, it can be connected to the flue of the sintering process to realize the transportation of flue gas.

[0035] In some embodiments, the third supply line 30 may further include a third flow meter located between the vaporizer 32 and the third valve 35 to monitor the gas flow rate within the third supply line 30 in order to meet the flow requirements of downstream users. In some embodiments, the third supply line 30 further includes a pressure regulating valve 33 located between the vaporizer 32 and the third valve 35 for pressure regulation.

[0036] The natural gas supply system proposed in this application combines the characteristics of regional resources, recovers and utilizes associated gas released from oil fields within the region, purchases natural gas from municipal pipelines, and stores liquefied LNG. It adopts a parallel supply process to achieve automatic complementarity, forming a safe natural gas supply guarantee system. Furthermore, it can prioritize the use of low-priced gas sources based on the prices of various natural gas sources, thereby reducing costs.

[0037] When supplying natural gas to users, the system first fully recovers and utilizes the low-priced associated gas from the oilfields released within the area. When user demand increases and the pressure on main pipeline 40 is low, the system automatically confirms the opening of the second valve 21 on the second supply pipeline 20, allowing municipal pipeline natural gas to serve as a secondary regulating source. When the pressure on main pipeline 40 is even lower, the third valve 35 on the third supply pipeline 30 is opened, allowing liquefied natural gas (LNG) to serve as a tertiary regulating source. This achieves automatic and complementary pressure adjustments across the three gas sources, forming a three-in-one natural gas security supply system that ensures the continuous, safe, and stable operation of the steel plant. Through these adjustments, the system fully utilizes the low-priced associated gas from the oilfields, reducing gas costs and achieving energy recovery and utilization; it also provides users with stable-pressure natural gas, ensuring production stability.

[0038] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature being directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0039] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", and "counterclockwise" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0040] In this application, unless otherwise expressly specified and limited, the terms "connection," "fixed," etc., should be interpreted broadly. For example, "fixed" can mean a fixed connection, a detachable connection, or an integral part; it can mean a mechanical connection or an electrical connection; it can mean a direct connection or an indirect connection through an intermediate medium; it can mean the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0041] Furthermore, the use of terms such as "first" and "second" in this application is for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, features defined with "first" or "second" may explicitly or implicitly include one or more features. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0042] Although embodiments of this application have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of this application, the scope of which is defined by the claims and their equivalents.

Claims

1. A natural gas supply system, characterized in that, include: user; The first supply pipeline includes a collection structure and a first valve connected in series, wherein the collection structure is used to collect associated gas from the oil field; The second supply pipeline includes pipes connected in series and a second valve, the pipes being connected to the municipal natural gas pipeline network; The third supply pipeline includes a storage tank and a third valve connected in series, wherein the storage tank is used to store liquefied natural gas; The main pipeline is equipped with a pressure gauge for detecting the gas pressure inside the main pipeline. The input end of the main pipeline is connected to the output ends of the first supply pipeline, the second supply pipeline, and the third supply pipeline. The output end of the main pipeline is connected to the user. The controller is electrically connected to the pressure gauge, the first valve, the second valve, and the third valve.

2. The natural gas supply system according to claim 1, characterized in that, The first supply line also includes a shut-off valve and a bypass line connected in parallel to the shut-off valve, wherein the shut-off valve is connected in series between the collecting structure and the first valve; The bypass pipeline is equipped with a filter and bypass valves located at the input and output ends of the filter, respectively.

3. The natural gas supply system according to claim 2, characterized in that, The first supply pipeline also includes a compressor, which is connected in series between the shut-off valve and the first valve; The input end of the compressor is connected to the output end of the bypass pipeline.

4. The natural gas supply system according to claim 3, characterized in that, The first supply pipeline also includes a first flow meter connected in series between the compressor and the first valve.

5. The natural gas supply system according to any one of claims 1-4, characterized in that, The second supply line also includes a second flow meter installed in the pipeline.

6. The natural gas supply system according to any one of claims 1-4, characterized in that, The third supply line also includes a vaporizer connected in series between the storage tank and the third valve.

7. The natural gas supply system according to claim 6, characterized in that, The vaporizer is a water bath type vaporizer.

8. The natural gas supply system according to claim 7, characterized in that, The third supply line also includes a heat exchanger; The heat exchanger is provided with a water channel and a gas channel. The outlet of the water channel is connected to the inlet of the water bath vaporizer, and the inlet of the gas channel is connected to the sintering flue gas collection structure.

9. The natural gas supply system according to claim 6, characterized in that, The third supply line also includes a third flow meter located between the vaporizer and the third valve.

10. The natural gas supply system according to claim 6, characterized in that, The third supply line also includes a pressure regulating valve located between the vaporizer and the third valve.

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