Recycling device for substandard exhaust gas of oil gas recovery system

Abstract

The invention discloses a substandard exhaust gas recycling device of an oil gas recovery system. The substandard exhaust gas outlet logic control system comprises an exhaust pipe and an emergency blow-down pipe, the exhaust pipe is provided with an explosive gas content analyzer and an outlet stop valve, the emergency blow-down pipe is provided with an emergency blow-down valve, and the explosive gas content analyzer is in interlocking control with the outlet stop valve and the emergency blow-down valve; the boiler feeding logic control system comprises a feeding pipe and a boiler, the feeding pipe is provided with a total hydrocarbon analyzer and a feeding cut-off valve, and the total hydrocarbon analyzer, the feeding cut-off valve and the emergency emptying valve are in interlocking control. The nitrogen adjusting control system controls the oxygen content percentage and the total hydrocarbon content percentage of the substandard exhaust gas pipeline, so that the substandard exhaust gas is stably fed into the boiler. According to the substandard exhaust gas recycling device of the oil gas recycling system, substandard exhaust gas of the oil gas recycling system is collected and conveyed to the boiler to serve as fuel gas to be combusted, resources are recycled, and meanwhile the problems of environmental pollution and the like can be solved.

Description

Technical Field

[0001] The present application relates to the technical field of treatment of substandard exhaust gas from oil and gas recovery systems, and in particular to a device for recycling substandard exhaust gas from oil and gas recovery systems. Background Art

[0002] With the rapid development of my country's economy, the consumption demand for petrochemical products is also increasing day by day. Petrochemical products are mostly a mixture of one or more hydrocarbons, among which the light hydrocarbon components are highly volatile. During the production, storage, transportation, and sales of products, part of the liquid light components evaporate and volatilize and escape into the atmosphere in the form of oil and gas, which will not only cause serious evaporation losses, but also bring potential accidents and environmental pollution problems.

[0003] To solve the problem of oil volatilization, oil and gas recovery measures need to be taken. At present, commonly used oil and gas recovery technologies include adsorption, absorption, condensation and membrane separation. With my country's increasing attention to environmental protection, the state or industry has successively formulated corresponding legal standards and specifications to strictly restrict oil and gas emissions. It is required to install oil and gas recovery and treatment devices in oil storage depots, gas stations and other places. The device should meet the oil and gas emission concentration of no more than 25000mg / m 3 And the oil and gas processing efficiency is not less than 95%.

[0004] Due to the improvement of standards, the exhaust emissions of the original oil and gas recovery systems in some oil depots cannot meet national standards, and it is necessary to upgrade and transform the oil and gas recovery equipment to solve problems such as oil and gas loss and environmental pollution caused by substandard exhaust gas. Summary of the invention

[0005] The purpose of this application is to provide a device for recycling substandard exhaust gas from an oil and gas recovery system, which sends the substandard exhaust gas from the oil and gas recovery system to a boiler for combustion as fuel gas, thereby recycling resources and solving problems such as environmental pollution.

[0006] The technical solution of the present application provides a device for recycling substandard exhaust gas from an oil and gas recovery system, a substandard exhaust gas outlet logic control system, and a boiler feed logic control system; the substandard exhaust gas outlet logic control system includes an exhaust pipe and an emergency vent pipe connected to the exhaust pipe; an explosion gas content analyzer and an outlet shut-off valve are installed on the exhaust pipe, and an emergency vent valve is installed on the emergency vent pipe; the explosion gas content analyzer, the outlet shut-off valve, and the emergency vent valve are all interlocked and controlled; the boiler feed logic control system includes a feed pipe and a boiler; the feed pipe is connected to the exhaust pipe, and a total hydrocarbon analyzer and a feed shut-off valve are installed on the feed pipe, and the total hydrocarbon analyzer, the feed shut-off valve, and the emergency vent valve are interlocked and controlled.

[0007] Optionally, the oil and gas recovery system's substandard exhaust gas recycling device also includes a nitrogen regulation and control system, the nitrogen regulation and control system also includes a nitrogen pipe connected to the exhaust pipe, the nitrogen pipe is located upstream of the explosion gas content analyzer, the nitrogen pipe is used to input nitrogen into the exhaust pipe, a nitrogen regulating valve is installed on the nitrogen pipe, the explosion gas content analyzer is control-connected to the nitrogen regulating valve to control the nitrogen regulating valve to open when the explosion gas content is lower than or equal to a first threshold value.

[0008] Optionally, the explosion gas content analyzer includes an oxygen content analyzer and a total hydrocarbon content analyzer which are sequentially installed on the exhaust pipe, and both the oxygen content analyzer and the total hydrocarbon content analyzer are interlocked with the emergency vent valve, the outlet shut-off valve and the nitrogen regulating valve.

[0009] Optionally, when the total hydrocarbon content measured by the total hydrocarbon analyzer is greater than a second threshold value, the feed cut-off valve is controlled to be closed, and at the same time, the emergency vent valve is opened and the outlet cut-off valve is closed.

[0010] Optionally, the feed pipe includes a feed main pipe and a first pipe and a second pipe connected in parallel to the feed main pipe, the total hydrocarbon analyzer and the feed shut-off valve are installed on the feed main pipe, and the first pipe and the second pipe are both connected to the boiler.

[0011] Optionally, a first pressure controller and a first cut-off valve are installed on the first pipe, and a second pressure controller and a second cut-off valve are installed on the second pipe; when the pressure measured by at least one of the first pressure controller and the second pressure controller is lower than a third threshold, the first cut-off valve and the second cut-off valve are controlled to be closed; when the pressure measured by both the first pressure controller and the second pressure controller is higher than a fourth threshold, the first cut-off valve and the second cut-off valve are controlled to be opened.

[0012] Optionally, the oil and gas recovery system substandard exhaust gas recycling device further includes a nitrogen source, a nitrogen supply main pipe connected to the nitrogen source, a first nitrogen supply pipe connected between the nitrogen source and the first pipe, and a second nitrogen supply pipe connected between the nitrogen source and the second pipe, and the nitrogen supply main pipe is connected to a third shut-off valve. The nitrogen regulation system is used to control the oxygen and total hydrocarbon content percentages of the substandard exhaust gas pipeline so that the substandard exhaust gas can be stably delivered to the downstream boiler.

[0013] Optionally, the first pressure controller and the second pressure controller are both interlocked with the third cut-off valve control, and when the first pressure controller and the second pressure controller measure a pressure value lower than the third threshold, the third cut-off valve is controlled to open.

[0014] Optionally, a first temperature controller controllably connected to the first shut-off valve is further installed on the first tube, and a second temperature controller controllably connected to the second shut-off valve is further installed on the second tube.

[0015] Optionally, flame arresters are installed on both the exhaust pipe and the emergency vent pipe.

[0016] The above technical solution has the following beneficial effects:

[0017] The oil and gas recovery system substandard exhaust gas recycling device provided in the present application receives the oil and gas recovery system substandard exhaust gas through the exhaust pipe and transmits it to the boiler as fuel gas for combustion, thereby reusing resources and solving the problem of environmental pollution caused by substandard exhaust gas. Reasonable interlocking control between the substandard exhaust gas outlet logic control system and the boiler feed logic control system ensures the safe and stable operation of the recovery system substandard exhaust gas as boiler fuel gas. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a schematic diagram of the structure of a device for recycling substandard exhaust gas from an oil and gas recovery system in one embodiment of the present application.

[0019] Reference Numbers

[0020] 1- logical control system for the outlet of substandard exhaust gas, 10- exhaust pipe, 100- explosion gas content analyzer, 101- oxygen content analyzer, 102- total hydrocarbon content analyzer, 11- emergency vent pipe, 110- emergency vent valve, 12- outlet cut-off valve, 13- nitrogen pipe, 130- nitrogen regulating valve.

[0021] 2-boiler feed logic control system, 20-feed pipe, 200-total hydrocarbon analyzer, 201-feed cut-off valve, 21-feed main pipe, 22-first pipe, 220-first pressure controller, 221-first cut-off valve, 222-first temperature controller, 23-second pipe, 230-second pressure controller, 231-second cut-off valve, 232-second temperature controller, 24-boiler, 25-nitrogen source, 26-nitrogen supply main pipe, 260-third cut-off valve, 27-first nitrogen supply pipe, 28-second nitrogen supply pipe.

[0022] 3- Flame arrester. DETAILED DESCRIPTION

[0023] The specific implementation of the present invention will be further described below in conjunction with the accompanying drawings.

[0024] It is easy to understand that according to the technical solution of the present invention, without changing the essential spirit of the present invention, a variety of structural modes and implementation modes that can be replaced by those skilled in the art can be replaced with each other. Therefore, the following specific implementation modes and drawings are only exemplary descriptions of the technical solution of the present invention, and should not be regarded as the whole of the present invention or as a limitation or restriction to the technical solution of the invention.

[0025] The directional terms such as up, down, left, right, front, back, front, back, top, bottom, etc. mentioned or may be mentioned in this specification are defined relative to the structures shown in the drawings. They are relative concepts and may change accordingly according to different positions and different usage conditions. Therefore, these or other directional terms should not be interpreted as restrictive terms.

[0026] like Figure 1 As shown, the present application provides a device for recycling substandard exhaust gas from an oil and gas recovery system, comprising: a substandard exhaust gas outlet logic control system 1 and a boiler feed logic control system 2.

[0027] The non-compliant exhaust gas outlet logic control system 1 includes an exhaust pipe 10 and an emergency vent pipe 11 connected to the exhaust pipe 10. The exhaust pipe 10 is used to receive the exhaust gas from the oil and gas recovery system, especially the non-compliant exhaust gas that does not comply with the "GB 20950-2020 Air Pollutant Emission Standard for Oil Storage Depots", "GB 20951-2020 Air Pollutant Emission Standard for Gasoline Transportation", and "GB 20952-2020 Air Pollutant Emission Standard for Gas Stations" revised by the Ministry of Environmental Protection on December 18, 2020.

[0028] The exhaust pipe 10 is installed with an explosion gas content analyzer 100 and an outlet shut-off valve 12, and the emergency vent pipe 11 is installed with an emergency vent valve 110. The explosion gas content analyzer 100, the emergency vent valve 110 and the outlet shut-off valve 12 are all interlocked, that is, controlled connected.

[0029] The boiler feed logic control system 2 includes a feed pipe 20 and a boiler 24 .

[0030] The feed pipe 20 is connected to the exhaust pipe 10, and a total hydrocarbon analyzer 200 and a feed cut-off valve 201 are installed on the feed pipe 20. The total hydrocarbon analyzer 200, the feed cut-off valve 201, and the emergency vent valve are interlocked, that is, controlled connected.

[0031] The oil and gas recovery system substandard exhaust gas recycling device provided in the present application receives the oil and gas recovery system substandard exhaust gas through the exhaust pipe 10 and transmits it to the boiler 24 as fuel gas for combustion, so that resources can be reused and the problem of environmental pollution caused by substandard exhaust gas can be solved at the same time. The safe and stable operation of the recovery system substandard exhaust gas as the boiler 24 fuel gas is ensured by reasonable interlocking control between the substandard exhaust gas outlet logic control system 1 and the boiler feed logic control system 2.

[0032] As an optional embodiment, the oil and gas recovery system substandard exhaust gas recycling device also includes a nitrogen regulation and control system, and the nitrogen regulation and control system also includes a nitrogen pipe 13 connected to the exhaust pipe 10, and the nitrogen pipe 13 is located upstream of the explosion gas content analyzer 100. The nitrogen pipe 13 is used to input nitrogen into the exhaust pipe 10. A nitrogen regulating valve 130 is installed on the nitrogen pipe 13. The explosion gas content analyzer 100 is interlocked with the nitrogen regulating valve 130 to control the nitrogen regulating valve 130 to open when the explosion gas (including oxygen and total hydrocarbon gas) content measured by the explosion gas content analyzer 100 is higher than or equal to a first threshold value. The embodiment of the present application is a self-locking control scheme for explosion gas, and the first threshold value may be that the oxygen content is greater than 5% and the total hydrocarbon concentration is greater than 5000 ppm [the oxygen content threshold value is determined according to the specific explosion gas in the actual exhaust gas (it may be 3.5%, 8%, 9%, 12%, etc.; the total hydrocarbon concentration is required to be lower than 15% of the lower explosion limit of the mixed gas (it may be 3000ppm, 4000ppm, 6000ppm, etc.)]. According to the actuator of the explosion gas content analyzer 100, the explosion gas content in the exhaust gas that does not meet the standards is analyzed, and the valve opening of the nitrogen regulating valve 130 (0% to 100%) is controlled to adjust the speed of adding nitrogen to the exhaust pipe 10, and the oxygen and total hydrocarbon content of the exhaust gas pipeline that does not meet the standards is controlled to be lower than the first threshold value, and the explosion gas content is controlled within a safe range, so that the exhaust gas that does not meet the standards can be stably delivered to the boiler to ensure the safe combustion of the boiler 24.

[0033] Furthermore, when the explosion gas content measured by the explosion gas content analyzer 100 is higher than or equal to a first threshold value, the outlet cut-off valve 12 is controlled to be closed at the same time to avoid the risk of the exhaust gas of the oil and gas recovery system entering the boiler and burning to cause an explosion; when the explosion gas content measured by the explosion gas content analyzer 100 is lower than the first threshold value, the nitrogen regulating valve 130 is controlled to be closed, and the outlet cut-off valve 12 is opened to supply gas to the boiler 24 normally.

[0034] As an optional embodiment, the explosion gas content analyzer 100 includes an oxygen content analyzer 101 and a total hydrocarbon content analyzer 102 which are sequentially installed on the exhaust pipe 10, and the oxygen content analyzer 101 and the total hydrocarbon content analyzer 102 are both controlled and connected with the emergency vent valve 110, the outlet cut-off valve 12 and the nitrogen regulating valve 130. The embodiment of the present application is a specific control method of the explosion gas self-locking control scheme, and the explosion gas is mainly oxygen and total hydrocarbon gas, so the oxygen content analyzer 101 and the total hydrocarbon content analyzer 102 are correspondingly set. When the oxygen content measured by the oxygen content analyzer 101 is ≤5% (volume fraction, a parameter of the first threshold value, this value is adjustable, determined according to the specific explosive gas in the actual exhaust gas, and can also be 3.5%, 8%, 9%, 12%, etc.), and the total hydrocarbon gas content is ≤5000ppm (this value is adjustable, another parameter of the first threshold value, which can be lower than 15% of the lower explosion limit of the mixed gas, and can also be 3000ppm, 4000ppm, 6000ppm, etc.), the outlet shut-off valve 12 is opened to allow the exhaust gas that does not meet the standards to be transported to the boiler 24 for combustion. When the content of oxygen and total hydrocarbon gas cannot meet the above conditions, the outlet shut-off valve 12 is closed, the emergency vent valve 110 is opened, and the nitrogen regulating valve 130 is fully opened to supplement nitrogen.

[0035] As an optional embodiment, when the total hydrocarbon content measured by the total hydrocarbon analyzer 200 is greater than the second threshold value, the feed shut-off valve 201 is controlled to be closed, and the emergency vent valve 110 is opened at the same time. The second threshold value in the embodiment of the present application requires that the total hydrocarbon is less than or equal to 10000ppm (this value is adjustable, and it can be lower than 25% of the lower explosion limit of the mixed gas). When it is higher than the second threshold value, there is a risk of explosion when the substandard exhaust gas is transported to the boiler 24 for combustion. At this time, the feed shut-off valve 201 and the outlet shut-off valve 12 are closed to achieve safety protection of the exhaust pipe 10, and the emergency vent valve 110 is opened to achieve venting. When the total hydrocarbon content is less than or equal to 7000ppm, the feed shut-off valve 201 is opened at this time, and there is no risk of explosion when the mixed gas is input into the boiler 24.

[0036] As an optional embodiment, the feed pipe 20 includes a feed main pipe 21 and a first pipe 22 and a second pipe 23 connected in parallel to the feed main pipe 21. The total hydrocarbon analyzer 200 and the feed cut-off valve 201 are installed on the feed main pipe 21. The first pipe 22 and the second pipe 23 are both connected to the boiler 24. When two fuel gas inlets are provided on the boiler 24, the first pipe 22 and the second pipe 23 achieve the effect of dual-line input of fuel gas to the boiler 24. The total hydrocarbon analyzer 200 and the feed cut-off valve 201 installed on the feed main pipe 21 are used to timely cut off the feed of the feed main pipe 21 when the total hydrocarbon analyzer 200 exceeds the standard, which is safe and effective.

[0037] As an optional embodiment, the first pipe 22 is equipped with a first pressure controller 220 and a first cut-off valve 221 that are controlled and connected, and the second pipe 23 is equipped with a second pressure controller 230 and a second cut-off valve 231 that are controlled and connected; when the pressure measured by at least one of the first pressure controller 220 and the second pressure controller 230 is lower than the third threshold, the first cut-off valve 221 and the second cut-off valve 231 are controlled to be closed; when the pressure measured by both the first pressure controller 220 and the second pressure controller 230 is higher than the fourth threshold, the first cut-off valve 221 and the second cut-off valve 231 are controlled to be opened. In the embodiment of the present application, the third threshold may be 4kPaG. When the pressure in the first pipe 22 and the second pipe 23 is lower than the pressure value, there is a risk of flashback due to the pressure in the first pipe 22 and the second pipe 23 being lower than the pressure in the boiler 24. The fourth threshold may be 10kPaG. When the pressure in the first pipe 22 and the second pipe 23 is higher than the value, the pressure value in the first pipe 22 and the second pipe 23 is greater than the pressure value in the boiler 24, and the exhaust gas is transported to the boiler 24 for safe combustion.

[0038] As an optional embodiment, the oil and gas recovery system substandard exhaust gas recycling device also includes a nitrogen source 25, a nitrogen supply main pipe 26 connected to the nitrogen source 25, a first nitrogen supply pipe 27 connected between the nitrogen source 25 and the first pipe 22, and a second nitrogen supply pipe 28 connected between the nitrogen source 25 and the second pipe 23, and a third shut-off valve 260 is connected to the nitrogen supply main pipe 26. When the embodiment of the present application is working, when the first shut-off valve 221 and the second shut-off valve 231 are all closed, the third shut-off valve 260 is opened to supplement nitrogen for 12s (this value is adjustable and determined according to actual conditions) or when any valve of the first shut-off valve 221 or the second shut-off valve 231 is opened, the third shut-off valve 260 is closed.

[0039] As an optional implementation, the first pressure controller 220 and the second pressure controller 230 are both interlocked with the third shut-off valve 260. When the pressure values ​​measured by the first pressure controller 220 and the second pressure controller 230 are lower than the third threshold value, the third shut-off valve 260 is controlled to be opened. In this embodiment of the application, when the pressure values ​​measured by the first pressure controller 220 and the second pressure controller 230 are lower than the third threshold value, the third shut-off valve 260 is opened to supplement the pressure values ​​of the first pipe 22 and the second pipe 23.

[0040] As an optional embodiment, a first temperature controller 222 connected to the first shut-off valve 221 is further installed on the first tube 22, and a second temperature controller 232 connected to the second shut-off valve 231 is further installed on the second tube 23. The embodiment of the present application is a temperature self-locking control scheme. When the temperature of the gas entering the boiler 24 is too high (such as 130°C), the first temperature controller 222 closes the first shut-off valve 221, and the second temperature controller 232 closes the second shut-off valve 231 to avoid a flashback accident.

[0041] As an optional embodiment, the exhaust pipe 10 and the emergency vent pipe 11 are both equipped with a flame arrester 3. The flame arrester 3 in the embodiment of the present application is a safety accessory used to prevent the spread of flames. It is composed of a flame arrester core, a flame arrester housing and accessories. The flame arrester 3 in the embodiment of the present application can be an existing two-way detonation-proof pipeline flame arrester 3.

[0042] As needed, the above technical solutions can be combined to achieve the best technical effect.

[0043] The above are only the principles and preferred embodiments of the present invention. It should be noted that, for those skilled in the art, several other modifications can be made based on the principles of the present invention, which should also be considered as the protection scope of the present invention.

Claims

1. A device for recycling substandard exhaust gas from an oil and gas recovery system, characterized in that: include: Substandard exhaust gas outlet logic control system and boiler feed logic control system; The non-standard exhaust gas outlet logic control system includes an exhaust pipe and an emergency vent pipe connected to the exhaust pipe; The exhaust pipe is equipped with an explosion gas content analyzer and an outlet cut-off valve, and the emergency vent pipe is equipped with an emergency vent valve; the explosion gas content analyzer, the outlet cut-off valve, and the emergency vent valve are all interlocked and controlled; The boiler feed logic control system includes a feed pipe and a boiler; The feed pipe is connected to the exhaust pipe, and a total hydrocarbon analyzer and a feed cut-off valve are installed on the feed pipe. The total hydrocarbon analyzer, the feed cut-off valve and the emergency vent valve are interlocked and controlled.

2. The device for recycling substandard exhaust gas from an oil and gas recovery system according to claim 1, characterized in that: The device for recycling substandard exhaust gas from the oil and gas recovery system also includes a nitrogen regulation and control system, which also includes a nitrogen pipe connected to the exhaust pipe, the nitrogen pipe is located upstream of the explosion gas content analyzer, the nitrogen pipe is used to replenish nitrogen to the exhaust pipe, and a nitrogen regulating valve is installed on the nitrogen pipe, the explosion gas content analyzer is control-connected to the nitrogen regulating valve to control the nitrogen regulating valve to open when the explosion gas content is higher than or equal to a first threshold value.

3. The device for recycling substandard exhaust gas from an oil and gas recovery system according to claim 2, characterized in that: The explosion gas content analyzer comprises an oxygen content analyzer and a total hydrocarbon content analyzer which are sequentially installed on the exhaust pipe. Both the oxygen content analyzer and the total hydrocarbon content analyzer are interlocked with the emergency vent valve, the outlet shut-off valve and the nitrogen regulating valve.

4. The device for recycling substandard exhaust gas from an oil and gas recovery system according to claim 2, characterized in that: When the total hydrocarbon content measured by the total hydrocarbon analyzer is greater than a second threshold value, the feed cut-off valve is controlled to be closed, and at the same time, the emergency vent valve is opened and the outlet cut-off valve is closed.

5. The device for recycling substandard exhaust gas from an oil and gas recovery system according to claim 4, characterized in that: The feed pipe includes a feed main pipe and a first pipe and a second pipe connected in parallel to the feed main pipe. The total hydrocarbon analyzer and the feed shut-off valve are installed on the feed main pipe. The first pipe and the second pipe are both connected to the boiler.

6. The device for recycling substandard exhaust gas from an oil and gas recovery system according to claim 5, characterized in that: The first pipe is equipped with a first pressure controller and a first cut-off valve for control connection, and the second pipe is equipped with a second pressure controller and a second cut-off valve for control connection; When the pressure measured by at least one of the first pressure controller and the second pressure controller is lower than the third threshold, the first cut-off valve and the second cut-off valve are controlled to be closed; when the pressure measured by both the first pressure controller and the second pressure controller is higher than the fourth threshold, the first cut-off valve and the second cut-off valve are controlled to be opened.

7. The device for recycling substandard exhaust gas from an oil and gas recovery system according to claim 6, characterized in that: The oil and gas recovery system substandard exhaust gas recycling device also includes a nitrogen source, a nitrogen supply main pipe connected to the nitrogen source, a first nitrogen supply pipe connected between the nitrogen source and the first pipe, and a second nitrogen supply pipe connected between the nitrogen source and the second pipe, and a third shut-off valve is connected to the nitrogen supply main pipe.

8. The device for recycling substandard exhaust gas from an oil and gas recovery system according to claim 7, characterized in that: The first pressure controller and the second pressure controller are both interlocked with the third cut-off valve control. When the pressure value measured by the first pressure controller and the second pressure controller is lower than the third threshold, the third cut-off valve is controlled to open.

9. The device for recycling substandard exhaust gas from an oil and gas recovery system according to claim 6, characterized in that: The first tube is also provided with a first temperature controller which is controllably connected to the first shut-off valve, and the second tube is also provided with a second temperature controller which is controllably connected to the second shut-off valve.

10. The device for recycling substandard exhaust gas from an oil and gas recovery system according to claim 2, characterized in that: Flame arresters are installed on the exhaust pipe and the emergency vent pipe.

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