RTO system for oil field

Abstract

The utility model discloses an RTO system for an oil field. The system comprises a first air inlet system, a second air inlet system and a heat storage combustion system. The first gas inlet system is used for feeding VOCs gas and first gas into the heat storage combustion system; the second gas inlet system is used for feeding oil field associated gas and combustion-supporting air into the heat storage combustion system; the gas treated by the heat storage combustion system is discharged from the discharge system; the first gas is at least used for purging the heat storage combustion system. According to the RTO system for the oil field, VOCs waste gas treatment and oil field associated gas are combined, and waste gas treatment is completed under the condition that extra fuel gas does not need to be used.

Description

Technical Field

[0001] The present application relates to a processing system, and more particularly to a RTO system for oil fields. Background Art

[0002] Some oilfield associated gas is discharged in an unorganized manner or directly discharged into the atmosphere after simple combustion. Secondly, the exhaust of oil tank breathing valves in oil fields, loading and unloading of oil products by tank trucks and other working conditions will result in small amounts of VOCs waste gas, large fluctuations in concentration, and no collection and treatment measures for VOCs waste gas, resulting in unorganized emissions. Such treatment poses greater safety risks and environmental problems. Utility Model Content

[0003] Purpose of the utility model: To solve the above problems, the present application provides an RTO system for oil fields. The RTO system for oil fields in the present application combines VOCs waste gas treatment with oil field associated gas, completing waste gas treatment without the use of additional fuel gas.

[0004] Technical solution: The RTO system for oil fields in the embodiment of the present application includes a first air intake system, a second air intake system and a thermal storage combustion system; the first air intake system is used to supply VOCs gas and a first gas to the thermal storage combustion system; the second air intake system is used to supply oilfield associated gas and combustion-supporting air to the thermal storage combustion system; the gas processed by the thermal storage combustion system is discharged from the exhaust system; the first gas is at least used to purge the thermal storage combustion system.

[0005] In some embodiments, the first air intake system includes a first pipeline for conveying VOCs gas, and a first valve is provided on the first pipeline;

[0006] The first air intake system further includes a second pipeline for conveying the first gas, and a second valve is provided on the second pipeline;

[0007] The outlets of the first pipeline and the second pipeline are respectively communicated with the first fan.

[0008] In some embodiments, the outlets of the first pipeline and the second pipeline are respectively connected to the third pipeline, the outlet of the third pipeline is connected to the first fan; and the outlet of the first fan is connected to the fourth pipeline.

[0009] In some embodiments, the second air intake system includes a fifth pipeline for feeding associated gas from the oil field; the fifth pipeline is connected to the main fire pipeline and the ignition pipeline of the burner respectively;

[0010] The second air intake system further includes a sixth pipeline, and the sixth pipeline is used to supply combustion air.

[0011] In some embodiments, the thermal storage combustion system includes a thermal storage combustion chamber, which includes a first thermal storage chamber, a second thermal storage chamber and a combustion chamber, and a burner is provided at the top of the combustion chamber.

[0012] In some embodiments, the burner is communicated with the burner main fire pipeline and the burner ignition pipeline respectively; the burner is also communicated with the sixth pipeline.

[0013] In some embodiments, the first heat storage chamber is connected to the fourth pipeline through an eighth pipeline, and the second heat storage chamber is connected to the fourth pipeline through a ninth pipeline; a third valve is provided on the eighth pipeline, and a fourth valve is provided on the ninth pipeline.

[0014] In some embodiments, the RTO system suitable for oil fields further includes a circulation system, which includes a buffer tank; the first heat storage chamber and the second heat storage chamber are respectively provided with a first outlet and a second outlet, and the first outlet and the second outlet are respectively connected to the buffer tank.

[0015] In some embodiments, the buffer tank is connected to a third fan, and the outlet of the third fan is connected to the inlet of the first fan.

[0016] In some embodiments, the first heat storage chamber is connected to the exhaust system through a twelfth pipeline; the second heat storage chamber is connected to the exhaust system through a thirteenth pipeline.

[0017] Beneficial Effects: This application provides an RTO system for oil fields, comprising a first air intake system, a second air intake system, and a regenerative combustion system. The first air intake system is used to supply VOCs gas and a first gas to the regenerative combustion system; the second air intake system is used to supply oilfield associated gas and combustion-supporting air to the regenerative combustion system; gas treated by the regenerative combustion system is discharged from an exhaust system; and the first gas is used at least to purge the regenerative combustion system. The RTO system for oil fields in this application combines VOCs waste gas treatment with oilfield associated gas, completing waste gas treatment without the use of additional fuel gas. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a schematic structural diagram of an RTO system used in an oil field according to an embodiment of the present application;

[0019] Figure 2 This is a structural diagram of the first air intake system in an embodiment of the present application;

[0020] Figure 3 This is a schematic diagram of the structure of the heat storage combustion system in the implementation of this application;

[0021] Figure 4Schematic diagram of the structure of the circulation system in the embodiment of the present application. DETAILED DESCRIPTION

[0022] The solution of this application is further described below with reference to the accompanying drawings.

[0023] In some embodiments, the RTO system for oil fields of the present application includes a first air intake system 100, such as Figure 1 and Figure 2 As shown, the first air intake system 100 includes a first pipeline 101 for conveying VOCs gas. A first valve 102 is provided on the first pipeline 101. The first valve 102 serves as a VOCs gas shut-off valve for controlling the opening and closing of the VOCs gas pipeline.

[0024] like Figure 2 As shown, in some embodiments, the first air intake system 100 further includes a second pipeline 103, and the second pipeline 103 is used to introduce a first gas. In some embodiments, the first gas can be any one or more of nitrogen, argon or air. A second valve 104 is provided on the second pipeline 103. The second valve 104 serves as a gas regulating valve, which is used to control the gas input amount and at the same time control the opening and closing of the second pipeline 103. In some embodiments, the first gas is air. In some embodiments, when the concentration of the VOCs gas fed from the first pipeline 101 is too high, air needs to be introduced from the second pipeline 103 to dilute the VOCs gas. At this time, the air introduced contains oxygen. When the diluted VOCs gas is fed into the regenerative combustion chamber 30 for treatment, the oxygen in the air can improve the oxidation efficiency of the VOCs gas.

[0025] In some embodiments, the pipeline outlets of the first pipeline 101 and the second pipeline 103 are simultaneously connected to the first fan 105. In other embodiments, the pipeline outlets of the first pipeline 101 and the second pipeline 103 are connected to the third pipeline 106, and the gas delivered by the first pipeline 101 and the second pipeline 102 is delivered to the first fan 105 through the third pipeline 106. The provision of the third pipeline 106 facilitates the maintenance of the entire system and simplifies the pipeline setting. In this application, the pipeline and the component such as the fan or the pipeline are connected by a flange (the same below), for example, the outlet of the third pipeline 106 is connected to the inlet of the first fan 105 by a flange.

[0026] In some embodiments, the first air intake system 100 further includes a fourth pipeline 107, which is connected to the outlet of the first fan 105. The outlet of the fourth pipeline 107 is connected to two air intake branches, namely an eighth pipeline 305 and a ninth pipeline 306. The eighth pipeline 305 is connected to the first thermal storage chamber 301, and the ninth pipeline 306 is connected to the second thermal storage chamber 302. After passing through the fourth pipeline 107, the VOCs gas is delivered to the first thermal storage chamber 301 and the second thermal storage chamber 302 through the eighth pipeline 305 and the ninth pipeline 306, respectively.

[0027] like Figure 1 As shown, the second air intake system 200 in the embodiment of the present application includes a fifth pipeline 201, which is used to supply oilfield associated gas and serves as the oilfield associated gas intake main; the second air intake system 200 also includes a sixth pipeline 202, which is used to supply combustion-supporting air, and the outlet of the sixth pipeline 202 is connected to the second fan 203, and the outlet of the second fan 203 is connected to the heat storage combustion system 300.

[0028] In some embodiments, the fifth pipeline 201 is connected to the burner main fire pipeline 204 and the burner ignition pipeline 205 respectively. In some embodiments, the fifth pipeline 201 is connected to the burner main fire pipeline 204 and the burner ignition pipeline 205 using a three-way flange.

[0029] In some embodiments, the second air intake system 200 further includes a seventh pipeline 206 , the inlet of the seventh pipeline 206 is connected to the outlet of the second fan 203 , and the outlet of the seventh pipeline 206 is connected to the burner 304 in the thermal storage combustion system 300 .

[0030] Regenerative thermal oxidation furnaces are referred to as RTOs. Volatile organic compounds in the exhaust gas react with oxygen in the air at a high temperature (above 760°C) within the oxidation furnace, producing water and carbon dioxide, which are released into the atmosphere. The incoming air is heated by regenerative ceramics and then heated to the set temperature by a burner for oxidation and decomposition. Upon discharge, the regenerative ceramics absorb most of the heat. The airflow direction is periodically switched by an airflow switching valve, cycling the heat absorption and heat release process of the regenerative ceramics. The high-temperature gas produced by oxidation flows through a specially designed ceramic regenerative element, causing it to heat up and "store heat." This "heat storage" is used to preheat the organic waste gas that subsequently enters, thereby saving fuel consumption for heating the waste gas. The ceramic regenerative element is divided into two or more zones or chambers. Each regenerative chamber undergoes a cycle of heat storage and heat release, working continuously over and over again.

[0031] Conventional RTOs typically handle large air volumes during design and operation, and the burner typically uses natural gas as fuel. This requires the configuration of additional natural gas system transportation pipelines, increasing both primary investment costs and natural gas operating energy costs. This system utilizes oilfield associated gas as fuel, and the RTO system burner only requires the corresponding air intake valve group, just like a conventional RTO, without the need for long transportation pipelines.

[0032] In some embodiments, as Figure 3 As shown, the main body of the regenerative combustion system 300 is the regenerative combustion chamber 30, which includes a first regenerative chamber 301, a second regenerative chamber 302 and a combustion chamber 303. The combustion chamber 303 is located between the two regenerative chambers. The first regenerative chamber 301 and the second regenerative chamber 302 are filled with regenerative ceramics. The first regenerative chamber 301, the second regenerative chamber 302 and the combustion chamber 303 are welded together as a whole.

[0033] In some embodiments, a burner 304 is provided on the top of the combustion chamber 303, and the burner 304 is connected to the burner main fire pipeline 204 and the burner ignition pipeline 205 respectively. In some embodiments, the burner fire pipeline 204, the burner ignition pipeline 205 and the burner 304 are connected by flanges.

[0034] In some embodiments, the first thermal storage chamber 301 is connected to the fourth pipeline 107 via an eighth pipeline 305, and the second thermal storage chamber 302 is connected to the fourth pipeline 107 via a ninth pipeline 306. In some embodiments, a third valve 307 is provided on the eighth pipeline 305, and a fourth valve 308 is provided on the ninth pipeline 306.

[0035] In some embodiments, the first heat storage chamber 301 is further connected to the twelfth pipeline 315, the second heat storage chamber 302 is connected to the thirteenth pipeline 316, the twelfth pipeline 315 and the thirteenth pipeline 316 are connected to the exhaust system 500, and the twelfth pipeline 315 is provided with a sixth valve 313, and the thirteenth pipeline 316 is provided with a seventh valve 314.

[0036] In some embodiments, the RTO system suitable for oil fields further includes a circulation system 400, which includes a buffer tank 401; the first heat storage chamber 301 and the second heat storage chamber 302 are respectively provided with a first outlet 309 and a second outlet 310, which are respectively connected to the buffer tank 401.

[0037] In some embodiments, the circulation system 400 includes a third fan 402, which is connected to the buffer tank 401. The third fan 402 is used to deliver gas from the buffer tank 401 to the first air intake system 100. In some specific embodiments, the outlet of the third fan 402 is connected to the inlet of the first fan 105, for example, the third fan 402 is connected to the third pipeline 106 via the tenth pipeline 403. The first outlet 309 is connected to the buffer tank 401 via the first circulation branch 311, and the second outlet is connected to the buffer tank 401 via the second circulation branch 312. In some embodiments, the first circulation branch 311 and the second circulation branch 312 are connected to the buffer tank 401 via the eleventh pipeline 406. In some embodiments, the eleventh pipeline 406 is provided with a fifth valve 404. In some embodiments, the buffer tank 401 is equipped with a safety valve 405 to regulate the internal pressure and ensure safe operation of the equipment.

[0038] During operation of the regenerative combustion system 300, the second fan 203 introduces room-temperature fresh air and oilfield associated gas to form a flame in the burner 304, maintaining the set temperature of the combustion chamber. The two regenerative chambers sequentially undergo an air intake and exhaust process. The third fan 402 directs the residual exhaust gas from the regenerative chamber after the intake phase into the buffer tank 401 for temporary storage, and ultimately introduces it into the first pipeline 101 for mixing with the VOC waste gas for further treatment. This prevents the regenerative chamber from switching to the exhaust phase and directly discharging the remaining untreated VOC waste gas into the chimney, thereby ensuring high removal efficiency of the RTO equipment.

[0039] From the above description, it can be seen that the fuel gas used in the RTO system for oil fields in this application is oil field associated gas. While solving environmental and safety problems such as unorganized emissions and incomplete combustion of oil field associated gas, no additional fuel gas is put into use, saving equipment operation investment costs. The RTO system uses oil field associated gas as fuel, and at the same time can solve the problem of treating unorganized VOCs waste gas generated by oil tank breathing gas, oil tanker loading and unloading, and sloppy oil pools, so that it meets emission standards. In addition, the waste gas from oil tank breathing gas, oil tanker loading and unloading, and sloppy oil pools in oil fields is usually tens of cubic meters or hundreds of cubic meters, and the amount of waste gas is not large. The equipment can be designed as a skid block, and the high degree of integration facilitates transportation to the waste gas generation point, which can solve the problem of scattered waste gas emission sources.

[0040] The embodiments of the present application also provide a method for treating exhaust gas from an RTO system in an oil field, comprising the following steps:

[0041] RTO startup phase:

[0042] When the RTO is started, the first valve 102 is closed, the second valve 104 is opened, and the third valve 307, the sixth valve 313, the fourth valve 308, and the seventh valve 314 are switched on and off respectively; fresh air is introduced from the second pipeline 103 through the first fan 105 to the combustion chamber 303, the first regenerator 301, and the second regenerator 302 for 5 to 10 minutes.

[0043] After the purge process is complete, the combustion air flows through the sixth pipeline 202, the second blower 203, and the seventh pipeline 206 into the burner 304. The oilfield associated gas flows through the fifth pipeline 201, the burner main fire pipeline 204, and the burner ignition pipeline 205 into the burner 304. A low flame is first ignited, and after the flame stabilizes, a high flame is ignited. The combustion continues in the combustion chamber 303. Once the combustion chamber 303 reaches the set temperature and the RTO is ready to process the exhaust gas, the first valve 102 is opened and the second valve 104 is closed, allowing the exhaust gas to enter the regenerative combustion chamber 30 for treatment.

[0044] The RTO goes through a startup phase, at which point the combustion chamber 303 has reached the set temperature;

[0045] Phase 1: Air enters the first regenerator 301 and exhausts from the second regenerator 302. VOCs waste gas passes through the first pipeline 101, is pressurized by the first fan 105, and then enters the first regenerator 301 through the fourth pipeline 107 before entering the combustion chamber 303. At this time, the third valve 307 and the seventh valve 314 are open, while the remaining sixth valve 313 and the fourth valve 308 are closed. The VOCs waste gas first passes through the thermal storage ceramics in the first regenerator 301 and enters the combustion chamber 303 for oxidation. It then enters the thermal storage ceramics in the second regenerator 302 to recover heat. After passing through the thirteenth pipeline 316, it enters the exhaust manifold and is discharged through the chimney of the exhaust system 500.

[0046] Phase 2: Air enters the second regenerator 302 and exhausts from the first regenerator 301. VOC waste gas flows through the first pipeline 101, is pressurized by the first fan 105, and then enters the second regenerator 302 through the fourth pipeline 107. At this point, the fourth valve 308 and the sixth valve 313 of the second regenerator 302 are open, while the third valve 307 and the seventh valve 314 are closed. Prior to the aforementioned switching process, since phase 1 involves air entering the first regenerator 301, some untreated VOC waste gas remains, requiring recirculation. Prior to the valve switching, the fifth valve 404 on the eleventh pipeline 406 is opened. The remaining waste gas flows through the first circulation branch 311, then through the eleventh pipeline 406, where it is pressurized by the third fan 402 and temporarily stored in the buffer tank 401 before entering the first pipeline 101 to improve the equipment's processing efficiency. The buffer tank 401 is equipped with a safety valve 405 to regulate the internal pressure and ensure safe operation. After the cycle is completed, the exhaust gas is first preheated by the heat storage ceramics in the second heat storage chamber 302 and then enters the combustion chamber 303 for oxidation. Then, the exhaust gas enters the heat storage ceramics in the first heat storage chamber 301 to recover the heat, and then enters the exhaust main pipe after passing through the twelfth pipeline 315 to be discharged into the chimney.

[0047] The above is one cycle of the RTO. The switching time of the switching valve is about 60 to 180 seconds. The fuel gas in all stages of this RTO system uses oilfield associated gas.

Claims

1. An RTO system for an oil field, characterized in that: The invention comprises a first air intake system (100), a second air intake system (200) and a thermal storage combustion system (300); the first air intake system (100) is used to feed VOCs gas and a first gas into the thermal storage combustion system (300); the second air intake system (200) is used to feed oilfield associated gas and combustion-supporting air into the thermal storage combustion system (300); the gas processed by the thermal storage combustion system (300) is discharged from an exhaust system (500); and the first gas is used at least to purge the thermal storage combustion system (300).

2. The RTO system for oil fields according to claim 1, characterized in that: The first air intake system (100) comprises a first pipeline (101) for conveying VOCs gas, and a first valve (102) is provided on the first pipeline (101); The first air intake system (100) further comprises a second pipeline (103) for conveying the first gas, and a second valve (104) is provided on the second pipeline (103); The outlets of the first pipeline (101) and the second pipeline (103) are respectively connected to the first fan (105).

3. The RTO system for oil fields according to claim 2, characterized in that: The outlets of the first pipeline (101) and the second pipeline (103) are respectively connected to the third pipeline (106), the outlet of the third pipeline (106) is connected to the first fan (105); and the outlet of the first fan (105) is connected to the fourth pipeline (107).

4. The RTO system for oil fields according to claim 3, characterized in that: The second air intake system (200) comprises a fifth pipeline (201), the fifth pipeline (201) being used to feed oilfield associated gas; the fifth pipeline (201) being respectively connected to the burner main fire pipeline (204) and the burner ignition pipeline (205); The second air intake system (200) further comprises a sixth pipeline (202), and the sixth pipeline (202) is used for introducing combustion-supporting air.

5. The RTO system for oil fields according to claim 4, characterized in that: The regenerative combustion system (300) comprises a regenerative combustion chamber (30), wherein the regenerative combustion chamber (30) comprises a first regenerative chamber (301), a second regenerative chamber (302), and a combustion chamber (303), wherein a burner (304) is provided at the top of the combustion chamber (303).

6. The RTO system for oil fields according to claim 5, characterized in that: The burner (304) is respectively connected to the burner main fire pipeline (204) and the burner ignition pipeline (205); the burner (304) is also connected to the sixth pipeline (202).

7. The RTO system for oil fields according to claim 5, characterized in that: The first heat storage chamber (301) is connected to the fourth pipeline (107) via an eighth pipeline (305), and the second heat storage chamber (302) is connected to the fourth pipeline (107) via a ninth pipeline (306); a third valve (307) is provided on the eighth pipeline (305), and a fourth valve (308) is provided on the ninth pipeline (306).

8. The RTO system for oil fields according to claim 5, characterized in that: The first heat storage chamber (301) is connected to the discharge system (500) via a twelfth pipeline (315); the second heat storage chamber (302) is connected to the discharge system (500) via a thirteenth pipeline (316).

9. The RTO system for oil fields according to claim 5, characterized in that: The RTO system for an oil field further comprises a circulation system (400), wherein the circulation system (400) comprises a buffer tank (401); the first heat storage chamber (301) and the second heat storage chamber (302) are respectively provided with a first outlet (309) and a second outlet (310), and the first outlet (309) and the second outlet (310) are respectively communicated with the buffer tank (401).

10. The RTO system for oil fields according to claim 9, characterized in that: The buffer tank (401) is connected to the third fan (402), and the outlet of the third fan (402) is connected to the inlet of the first fan (105).

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