A natural gas odorizing apparatus and method

Abstract

The application relates to the technical field of natural gas odorization, and particularly discloses a natural gas odorization agent injection device and method, which comprises a natural gas main pipeline, an odorization bypass and a controller; a pressure regulating valve, a front pressure gauge and a rear pressure gauge are sequentially arranged on the natural gas main pipeline according to the flowing direction of natural gas; the odorization bypass comprises a second natural gas branch pipeline, a first natural gas branch pipeline, an odorization tank and an electric valve; one end of the first natural gas branch pipeline is connected with the natural gas main pipeline, the other end of the first natural gas branch pipeline extends into the odorization tank, and the electric valve is arranged on the first natural gas branch pipeline; one end of the second natural gas branch pipeline is connected with the natural gas main pipeline; the other end of the second natural gas branch pipeline extends into the odorization tank; the odorization tank stores odorization agents; and the pressure regulating valve, the front pressure gauge, the rear pressure gauge and the electric valve are in communication connection with the controller. According to the application, the amount of natural gas flowing on the natural gas main pipeline is controlled to control the amount of natural gas entering the odorization bypass, so that the accurate control of natural gas odorization is realized.

Description

Technical Field

[0001] This invention relates to the field of natural gas odorization technology, specifically to a natural gas odorant injection device and method. Background Technology

[0002] Due to its colorless, odorless, flammable, and explosive physical properties, natural gas leaks are highly susceptible to occurring insidiously, leading to safety accidents such as natural gas poisoning, fires, and explosions, causing losses to people's property and even lives. In the natural gas industry, odorization is a crucial step in ensuring the safe transportation of natural gas, a requirement of national technical regulations, and is related to the safety and quality of urban natural gas.

[0003] Natural gas odorization is the process of injecting a distinctive, unpleasant odorant into natural gas to ensure the detection of leaks. The odorant is an organic compound or mixture with a strong odor, containing sulfur, low toxicity, flammability, explosiveness, and high cost. When added to natural gas at very low concentrations, the natural gas will have a special, unpleasant warning odor so that leaks can be detected when they reach 5% of their lower explosive limit or a concentration that is permissible to humans.

[0004] Currently, commonly used natural gas odorization devices are powered by plunger pumps. These devices have high investment and maintenance costs, are difficult to adjust, and suffer from uneven mixing and inaccurate natural gas odorization. Therefore, there is a need to provide a high-precision natural gas odorant injection device and method to ensure that the odorant concentration in the natural gas entering the user's end meets the requirements. Thus, this invention proposes a high-precision natural gas odorant injection device and method to solve the problems existing in the prior art. Summary of the Invention

[0005] The purpose of this invention is to provide a natural gas odorant injection device and method, which controls the amount of natural gas entering the odorization bypass according to the natural gas flow rate on the main natural gas pipeline, thereby achieving accurate control of natural gas odorization.

[0006] This invention is achieved through the following technical solution:

[0007] A natural gas odorant injection device includes a natural gas main pipeline, an odorant bypass, and a controller;

[0008] The main natural gas pipeline is equipped with a pressure regulating valve, a front pressure gauge, and a rear pressure gauge in sequence according to the natural gas flow direction.

[0009] The odorization bypass includes a second natural gas branch pipeline, a first natural gas branch pipeline, an odorization tank, and an electric valve;

[0010] One end of the first natural gas branch pipeline is connected to the main natural gas pipeline and is located at the rear end of the front pressure gauge. The other end of the first natural gas branch pipeline extends into the odorization tank and is placed below the odorant liquid level. The electric valve is installed on the first natural gas branch pipeline.

[0011] One end of the second natural gas branch pipeline is connected to the main natural gas pipeline and is located in front of the rear pressure gauge; the other end of the second natural gas branch pipeline extends into the odorizing tank and is positioned above the odorizing agent liquid level.

[0012] The odorizing container contains an odorizing agent;

[0013] The pressure regulating valve, the front pressure gauge, the rear pressure gauge, and the electric valve are all connected in communication with the controller. The controller controls the opening degree of the electric valve according to the natural gas flow between the odorization bypass in the main natural gas pipeline.

[0014] The concept of this invention is to construct an odorization bypass with the concentration of odorant in the main natural gas pipeline as the control target. Since the concentration of odorant in the main natural gas pipeline is related to the natural gas flow rate and the amount of odorant added, the concentration of odorant in the main natural gas pipeline can be controlled by controlling the flow ratio of odorized natural gas and non-odorized natural gas.

[0015] Therefore, this invention sequentially installs an electric valve and an odorizing tank containing odorant on the odorization bypass, and installs a pre-pressure gauge and a post-pressure gauge on the main natural gas pipeline for collecting natural gas flow. Based on the pressure collected by the pre-pressure gauge and the post-pressure gauge, the natural gas flow between the bypass inlet and outlet in the main pipeline is calculated, and the calculated natural gas flow is transmitted to a controller. The controller controls the opening of the electric valve according to the natural gas flow, wherein the opening of the regulating valve can be used to regulate the natural gas flow between the bypass inlet and outlet in the main pipeline.

[0016] Furthermore, the odorization bypass also includes an acceleration pipe, one end of which is connected to the first natural gas branch pipe, and the other end extends into the odorant liquid surface in the odorization tank and is equipped with a regulating valve; the acceleration pipe is used to increase the flow rate of natural gas, and the regulating valve is used to control the natural gas to enter the odorization tank and mix with the odorant.

[0017] Furthermore, the regulating valve is a needle valve, and the natural gas passes through the acceleration pipe and the needle valve in sequence, mixing with the odorant in the form of bubbles.

[0018] Furthermore, the acceleration pipe is equipped with multiple channels of different cross-sectional areas, with each channel corresponding to a different acceleration level. The electric valve is located at the inlet end of the acceleration pipe and is used to control the natural gas entering the channels of different cross-sectional areas, thereby achieving different acceleration levels. The faster the acceleration, the more natural gas enters the odorization tank in the same amount of time, and the more natural gas carries the odorant back to the main natural gas pipeline.

[0019] Furthermore, the cross-sections of all the different channels are circular.

[0020] Furthermore, channels with the same cross-sectional area are arranged in rows.

[0021] Furthermore, the other end of the accelerator tube is connected to multiple precision needle valves with different flow rates, and the precision needle valves with different flow rates correspond to channels with different cross-sectional areas inside the accelerator tube.

[0022] Furthermore, a concentration detection sensor is installed at the rear end of the second natural gas branch pipeline on the main natural gas pipeline. The concentration detection sensor is used to collect the concentration of odorant in the main natural gas pipeline and transmit the collected odorant concentration to the controller. The controller determines whether the collected odorant concentration is within the error range. If not, it controls the electric valve to adjust the opening. When an acceleration pipe is installed at the rear end of the first natural gas branch pipeline, the electric valve is used to adjust and open different acceleration channels of the acceleration pipe.

[0023] Furthermore, both the front and rear pressure gauges employ high-resolution, high-precision pressure gauges.

[0024] The odorization method based on a natural gas odorant injection device includes the following steps:

[0025] S1. Natural gas enters the odorization bypass and flows through the pre- and post-pressure gauges in the main natural gas pipeline via a pressure regulating valve. The controller calculates the flow rate of natural gas flowing through the main natural gas pipeline based on the pressure difference between the pre- and post-pressure gauges. The controller controls the opening of the electric valve based on the calculated natural gas flow rate, thereby controlling the flow rate of natural gas carrying odorant back to the main natural gas pipeline and achieving odor concentration control. When an acceleration pipe is installed at the rear end of the first natural gas branch pipeline, the electric valve adjusts the opening of different acceleration channels of the acceleration pipe to control the flow rate of natural gas carrying odorant back to the main natural gas pipeline and achieve odor concentration control.

[0026] The expression for natural gas flow rate is as follows:

[0027] Q = k(V1 - V2)

[0028] Where Q is the natural gas flow rate, k is the flow coefficient, V1 is the pressure value measured by the upstream pressure gauge, and V2 is the pressure value measured by the downstream pressure gauge.

[0029] S2. The natural gas entering the odorization bypass enters the odorization tank through the first natural gas branch pipeline and mixes with the odorizing agent. The natural gas mixed with the odorizing agent returns to the main natural gas pipeline through the second natural gas branch pipeline, thus realizing the odorization of natural gas in the main natural gas pipeline.

[0030] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0031] 1. This invention involves sequentially installing an electric valve and an odorizing tank containing odorant on the odorization bypass, and installing a pre-pressure gauge and a post-pressure gauge on the main natural gas pipeline for collecting natural gas flow. Based on the pressure collected by the pre-pressure gauge and the post-pressure gauge, the natural gas flow between the bypass inlet and outlet in the main pipeline is calculated, and the calculated natural gas flow is transmitted to a controller. The controller controls the opening of the electric valve according to the natural gas flow, thereby adjusting the natural gas flow in the main odorizing tank of the odorization bypass to odorize the natural gas in the main natural gas pipeline. This allows for precise odorization of natural gas based on the actual flow rate used by the user. Compared with the existing technology that uses a plunger pump for odorization, this invention reduces costs and avoids the problem of complicated adjustment.

[0032] 2. By setting up an acceleration tube and a needle valve, this invention not only enables natural gas to be mixed with odorant in the form of bubbles, but also odorizes the natural gas in the pipeline through a staged odorization method, ensuring precise control of the odorant concentration in the main natural gas pipeline, achieving the standard concentration of natural gas odorant, and reducing safety risks. Attached Figure Description

[0033] The accompanying drawings, which are included to provide a further understanding of embodiments of the invention and form part of this application, do not constitute a limitation thereof. In the drawings:

[0034] Figure 1 This is a schematic diagram of the natural gas odorant injection device of the present invention;

[0035] Figure 2 This is a cross-sectional view of the accelerator tube.

[0036] The attached diagram shows the markings and corresponding component names:

[0037] 1-Main natural gas pipeline; 2-Pressure regulating valve; 3-Second natural gas branch pipeline; 4-Pressure gauge; 5-First natural gas branch pipeline; 6-Electric valve; 7-Accelerator pipe; 8-Needle valve; 9-Odor-adding tank; 10-Rear pressure gauge. Detailed Implementation

[0038] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the embodiments and accompanying drawings. The illustrative embodiments and descriptions of the present invention are only used to explain the present invention and are not intended to limit the present invention.

[0039] In the following description, numerous specific details are set forth in order to provide a thorough understanding of the invention. However, it will be apparent to those skilled in the art that these specific details are not necessary to practice the invention. In other embodiments, well-known structures, materials, or methods have not been specifically described in order to avoid obscuring the invention.

[0040] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0041] Example 1:

[0042] like Figure 1 , Figure 2 As shown, a natural gas odorant injection device includes a natural gas main pipeline 1, an odorant bypass, and a controller;

[0043] The main natural gas pipeline 1 is equipped with a pressure regulating valve 2, a front pressure gauge 4, and a rear pressure gauge 10 in sequence according to the natural gas flow direction. The front pressure gauge 4 and the rear pressure gauge 10 are high-resolution and high-precision pressure gauges. The front pressure gauge 4 and the rear pressure gauge 10 are used to collect the pressure of natural gas when the user uses natural gas. The controller calculates the natural gas flow rate between the odorization bypass inlet and outlet in the main natural gas pipeline 1 based on the collected pressure.

[0044] The odorization bypass includes a second natural gas branch pipeline 3, a first natural gas branch pipeline 5, an odorization tank 9, and an electric valve 6; wherein, the odorization tank 9 stores an odorant, which may be tetrahydrothiophene.

[0045] One end of the first natural gas branch pipe 5 is connected to the main natural gas pipe 1 and is located at the rear end of the front pressure gauge 4. The other end of the first natural gas branch pipe 5 extends into the odorizing tank 9 and is placed below the odorizing agent liquid level. The electric valve 6 is installed on the first natural gas branch pipe 5. Preferably, the other end of the first natural gas branch pipe 5 extends into the odorizing tank 9 from the bottom of the odorizing tank 9.

[0046] One end of the second natural gas branch pipe 3 is connected to the main natural gas pipeline 1 and is located at the front end of the rear pressure gauge 10; the other end of the second natural gas branch pipe 3 extends into the odorizing tank 9 and is placed above the odorizing agent liquid surface; preferably, the second natural gas branch pipe 3 extends into the odorizing tank 9 from the top of the odorizing tank 9.

[0047] A portion of the natural gas passing through the pressure regulating valve 2 enters the odorization tank 9 through the first natural gas branch pipeline 5 and mixes with the odorant. The natural gas carrying the odorant then returns to the main natural gas pipeline 1 through the second natural gas branch pipeline 3 and mixes with the natural gas in the main natural gas pipeline 1 to achieve odorization treatment of the natural gas in the main natural gas pipeline 1.

[0048] The pressure regulating valve 2, the front pressure gauge 4, the rear pressure gauge 10, and the electric valve 6 are all communicatively connected to the controller. The controller controls the opening degree of the electric valve 6 based on the natural gas flow rate between the odorization bypass and the main natural gas pipeline 1. The controller may specifically be a PLC, etc.

[0049] This embodiment installs an electric valve 6 and an odorizing tank 9 containing odorant in sequence on the odorization bypass, and installs a front pressure gauge 4 and a rear pressure gauge 10 on the main natural gas pipeline 1. By controlling the opening of the electric valve 6, the flow rate of natural gas in the odorization bypass odorizing tank 9 is adjusted to odorize the natural gas in the main natural gas pipeline 1. This allows for precise odorization of natural gas based on the actual flow rate used by the user. Compared with the existing technology that uses a plunger pump for odorization, this reduces costs and avoids the problem of complicated adjustment.

[0050] In a preferred embodiment, the odorization bypass further includes an acceleration pipe 7, one end of which is connected to the first natural gas branch pipe 5, and the other end extends into the odorant liquid level in the odorization tank 9 and is equipped with a regulating valve. The acceleration pipe 7 is used to increase the flow rate of natural gas, and the regulating valve is used to control the natural gas entering the odorization tank 9 to mix with the odorant. Specifically, the regulating valve is a needle valve 8, and the natural gas passes through the acceleration pipe 7 and the needle valve 8 in sequence, mixing with the odorant in the form of bubbles.

[0051] In this embodiment, by setting up an acceleration pipe 7 and a needle valve 8, natural gas is mixed with odorant in the form of bubbles, which improves the uniformity of the mixing of odorant and natural gas, so that natural gas can better carry odorant into the natural gas main pipeline 1 for odorization treatment.

[0052] In a preferred embodiment, the acceleration pipe 7 is provided with multiple channels of different cross-sectional areas; each channel corresponds to a different acceleration level. The electric valve 6 is located at the inlet end of the acceleration pipe 7 and is used to control the natural gas entering the channels of different cross-sectional areas, thereby controlling the acceleration level. The faster the acceleration, the more natural gas enters the odorization tank 9 in the same amount of time, and the more natural gas carries the odorant back to the main natural gas pipeline 1. The cross-sections of the different channels can be circular or square, etc., preferably circular. Preferably, channels of the same cross-sectional area are arranged in a row, for example: Figure 2 As shown, the accelerator tube 7 has three channels with different cross-sectional areas; each cross-sectional area contains three channels, and the three channels are arranged in a row. The three channels with different cross-sectional areas can be arranged in a specific order. Figure 2 The figures are arranged from left to right in descending order of size.

[0053] In a preferred embodiment, the other end of the accelerator tube 7 is connected to multiple precision needle valves 8 with different flow rates. The precision needle valves 8 with different flow rates correspond to channels with different cross-sectional areas within the accelerator tube 7; that is, the flow rate of the precision needle valves 8 with different flow rates is proportional to the cross-sectional area of ​​the accelerator tube 7. For example, when the accelerator tube 7 is as follows... Figure 2 In the structure shown, there are three precision needle valves 8, each corresponding to one of the three flow rates.

[0054] In a preferred embodiment, a concentration detection sensor is installed at the rear end of the second natural gas branch pipeline 3 on the main natural gas pipeline 1. The concentration detection sensor is used to collect the concentration of odorant in the main natural gas pipeline 1 and transmit the collected odorant concentration to the controller. The controller determines whether the collected odorant concentration is within the error range. If not, it controls the electric valve 6 to adjust the opening degree. When an acceleration pipe 7 is installed at the rear end of the first natural gas branch pipeline 5, the electric valve 6 is used to adjust and open different acceleration channels of the acceleration pipe 7.

[0055] To evaluate the diffusion degree of odorant concentration and describe the deviation between the odorant concentration and the set concentration, an odorant concentration deviation index is defined as m, which is shown in the following formula:

[0056]

[0057] In the formula: W (x) is the concentration value of any finite element within the pipeline network, i.e., the concentration collected by the concentration detection sensor; w is the set concentration, and the concentration deviation should not exceed 10%.

[0058] The odorization method based on the natural gas odorant injection device in this embodiment includes the following steps:

[0059] S1. Natural gas enters the odorization bypass and the front and rear pressure gauges 4 and 10 in the main natural gas pipeline 1 through the pressure regulating valve 2. The controller calculates the flow rate of natural gas flowing through the main natural gas pipeline 1 based on the pressure difference between the front and rear pressure gauges 4 and 10. The controller controls the opening of the electric valve 6 according to the calculated natural gas flow rate. By controlling the opening of the electric valve 6, the flow rate of natural gas carrying odorant back to the main natural gas pipeline 1 is controlled, thereby achieving odorization concentration control. When an acceleration pipe 7 is installed at the rear end of the first natural gas branch pipeline 5, the electric valve 6 is used to adjust and open different acceleration channels of the acceleration pipe 7 to achieve the flow rate of natural gas carrying odorant back to the main natural gas pipeline 1, thereby achieving odorization concentration control.

[0060] The expression for natural gas flow rate is as follows:

[0061] Q = k(V1 - V2)

[0062] Where Q is the natural gas flow rate, k is the flow coefficient, V1 is the pressure value measured by the upstream pressure gauge, and V2 is the pressure value measured by the downstream pressure gauge.

[0063] S2. The natural gas entering the odorization bypass enters the odorization tank 9 through the first natural gas branch pipeline 5 and mixes with the odorizing agent. The natural gas mixed with the odorizing agent returns to the main natural gas pipeline 1 through the second natural gas branch pipeline 3, thus realizing the odorization of natural gas in the main natural gas pipeline 1.

[0064] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

[0065] It should be noted that the structures, proportions, sizes, etc., illustrated in the accompanying drawings are merely for illustrative purposes to aid those skilled in the art and are not intended to limit the scope of the invention. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in proportions, or adjustments to size, without affecting the effectiveness and purpose of the invention, should still fall within the scope of the disclosed technical content. Furthermore, terms such as "upper," "lower," "left," "right," and "middle" used in this specification are merely for clarity and not intended to limit the scope of the invention. Changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered within the scope of the invention.

Claims

1. A natural gas odorant injection device, characterized in that, Includes the main natural gas pipeline (1), the odorization bypass, and the controller; The main natural gas pipeline (1) is equipped with a pressure regulating valve (2), a front pressure gauge (4) and a rear pressure gauge (10) in sequence according to the natural gas flow direction. The odorization bypass includes a second natural gas branch pipeline (3), a first natural gas branch pipeline (5), an odorization tank (9), and an electric valve (6); One end of the first natural gas branch pipe (5) is connected to the natural gas main pipe (1) and is located at the rear end of the front pressure gauge (4). The other end of the first natural gas branch pipe (5) extends into the odorizing tank (9) and is placed below the odorizing agent liquid level. The electric valve (6) is installed on the first natural gas branch pipe (5). One end of the second natural gas branch pipe (3) is connected to the main natural gas pipeline (1) and is located at the front end of the rear pressure gauge (10); the other end of the second natural gas branch pipe (3) extends into the odorizing tank (9) and is placed above the odorizing agent liquid level; The odorizing tank (9) contains an odorizing agent; The pressure regulating valve (2), the front pressure gauge (4), the rear pressure gauge (10) and the electric valve (6) are all connected to the controller. The controller controls the opening degree of the electric valve (6) according to the natural gas flow between the odor bypass in the main natural gas pipeline (1). The odorization bypass also includes an acceleration pipe (7), one end of which is connected to the first natural gas branch pipe (5), and the other end extends into the odorant liquid surface in the odorization tank (9) and is equipped with a regulating valve; the acceleration pipe (7) is used to increase the flow rate of natural gas, and the regulating valve is used to control the natural gas to enter the odorization tank (9) and mix with the odorant; the acceleration pipe (7) is provided with multiple channels with different cross-sectional areas, and the electric valve (6) is set at the inlet end of the acceleration pipe (7) to control the natural gas to enter the channels with different cross-sectional areas.

2. The natural gas odorant injection device according to claim 1, characterized in that, The regulating valve is a needle valve (8). Natural gas passes through the acceleration pipe (7) and the needle valve (8) in sequence and mixes with the odorant in the form of bubbles.

3. The natural gas odorant injection device according to claim 1, characterized in that, The cross-sections of all channels are circular.

4. The natural gas odorant injection device according to claim 1, characterized in that, Channels with the same cross-sectional area are arranged in rows.

5. A natural gas odorant injection device according to claim 1, characterized in that, The other end of the acceleration tube (7) is connected to a number of precision needle valves (8) with different flow rates. The precision needle valves (8) with different flow rates correspond to channels with different cross-sectional areas inside the acceleration tube (7).

6. A natural gas odorant injection device according to claim 1, characterized in that, A concentration detection sensor is installed at the rear end of the second natural gas branch pipeline (3) on the main natural gas pipeline (1). The concentration detection sensor is used to collect the concentration of odorant in the main natural gas pipeline (1) and transmit the collected odorant concentration to the controller. The controller determines whether the collected odorant concentration is within the error range. If not, it controls the electric valve (6) to adjust the opening.

7. A natural gas odorant injection device according to any one of claims 1-6, characterized in that, The front pressure gauge (4) and the rear pressure gauge (10) are high-resolution, high-precision pressure gauges.

8. An odorization method based on the natural gas odorant injection device according to any one of claims 1-7, characterized in that, Includes the following steps: S1. Natural gas enters the odorization bypass and flows through the front pressure gauge (4) and the rear pressure gauge (10) in the natural gas main pipeline (1) under the control of the pressure regulating valve (2). The controller calculates the flow rate of natural gas from the natural gas main pipeline (1) by the pressure difference between the front pressure gauge (4) and the rear pressure gauge (10). The controller controls the opening degree of the electric valve (6) according to the calculated natural gas flow rate. S2. The natural gas entering the odorization bypass enters the odorization tank (9) through the first natural gas branch pipeline (5) and mixes with the odorizing agent. The natural gas mixed with the odorizing agent returns to the main natural gas pipeline (1) through the second natural gas branch pipeline (3), thus realizing the odorization of natural gas in the main natural gas pipeline (1).

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