A comprehensive waste gas treatment system device and system method for the entire plant

Abstract

The present invention provides a comprehensive plant-wide waste gas treatment system and method. The system includes an exhaust gas pipeline equipped with a calorific value detection component. The exhaust gas pipeline is divided into two branches: one connected to the fuel inlet of a ground flare and the other connected to an incinerator. The exhaust gas pipeline is also connected to the gas inlet of an exhaust gas storage device, and the gas outlet of the exhaust gas storage device is connected to the fuel inlet of the ground flare. This system and method utilize a more economical low-calorific value exhaust gas treatment method, significantly reducing equipment operating costs. The system monitors the calorific value of the exhaust gas online and automatically selects the most appropriate exhaust gas treatment process based on the exhaust gas characteristics, effectively reducing pollutant emissions.

Description

Technical Field

[0001] The present invention belongs to the technical field of waste gas treatment, and relates to a comprehensive waste gas treatment system device and system method for the entire plant. Background Art

[0002] Large petrochemical plants, refineries, and other enterprises experience a variety of emissions during process system operation, including plant-wide accident emissions, emergency purge emissions, start-up and shutdown emissions, inspection and maintenance emissions, and fugitive emissions. The exhaust gas streams from these various emission conditions vary in composition, calorific value, organic matter concentration, emission volume, and duration. To prevent fires and explosions and ensure the safety of equipment and personnel, these enterprises typically install a flare system combined with an incinerator system to comprehensively treat these exhaust gases.

[0003] The flare system and the incinerator system have their own characteristics, but they both have certain requirements for the calorific value of the exhaust gas. For example, SH3009-2013 requires that the calorific value of the exhaust gas fed into the flare should be ≥7880kJ / Nm 3 GB18484-2020 requires that the incinerator's combustion temperature must be ≥1100°C. Therefore, for low-calorific value exhaust gas, in order to ensure exhaust gas treatment efficiency, whether using a flare system or an incinerator system for treatment, a large amount of additional fuel gas must be added for supplementary combustion, which greatly increases the operating cost of the equipment.

[0004] Furthermore, flare systems and incinerator systems differ in their adaptability to different waste gas discharge conditions. Flare systems are suited to treating high-flow, intermittent waste gas flows, but are less efficient at treating low-flow waste gas flows. Incinerator systems, on the other hand, are more suited to treating stable, low-flow waste gas flows. However, high waste gas flows can cause furnace temperature fluctuations, leading to increased pollutant emissions. Due to the complex emission conditions of large-scale process units, disorderly waste gas emissions remain a common phenomenon. When various waste gases are directed to inappropriate treatment equipment, plant-wide pollutant emissions can be significantly elevated. Summary of the Invention

[0005] In order to solve the technical problems existing in the prior art, the present invention provides a comprehensive waste gas treatment system device and system method for the entire plant. The system device and system method adopt a more economical low-calorific value waste gas treatment method, which can significantly reduce the equipment operating cost, can monitor the calorific value of the waste gas online, and automatically select the most suitable waste gas treatment process according to the characteristics of the waste gas, which can effectively reduce pollutant emissions.

[0006] In order to achieve the above technical effects, the present invention adopts the following technical solutions:

[0007] One of the purposes of the present invention is to provide a comprehensive waste gas treatment system for the entire plant, the system comprising a waste gas pipeline, a calorific value detection component being provided on the waste gas pipeline, the waste gas pipeline being divided into two branches, one being connected to the fuel inlet of the ground flare, and the other being connected to the incineration device;

[0008] The exhaust gas pipeline is further connected to the gas inlet of the exhaust gas storage device, and the gas outlet of the exhaust gas storage device is connected to the fuel inlet of the ground flare.

[0009] As a preferred technical solution of the present invention, the ground flare includes a flare burner array, and a radiation protection component is arranged on the periphery of the flare burner array.

[0010] As a preferred technical solution of the present invention, a permanent lamp is provided on one side of the flare burner.

[0011] As a preferred technical solution of the present invention, a wind shield is provided on the head of the ever-burning lamp adjacent to the radiation protection component, and the wind shield is provided with an air inlet hole.

[0012] As a preferred technical solution of the present invention, the incineration device is connected to the waste heat recovery device, and the steam outlet of the waste heat recovery device is connected to the flare burner.

[0013] A second object of the present invention is to provide a comprehensive waste gas treatment system method for the entire plant. The system method uses the comprehensive waste gas treatment system device for the entire plant provided in the first object, and the system method includes:

[0014] Using a calorific value detection component to detect the calorific value of the exhaust gas, and selecting whether to send the exhaust gas to the ground flare or incineration device according to the result of the calorific value detection;

[0015] According to the result of the calorific value detection, when the calorific value of the exhaust gas is lower than the calorific value requirement of the ground flare, the exhaust gas is sent to the exhaust gas storage device.

[0016] As a preferred technical solution of the present invention, as a result of the calorific value detection, the high calorific value exhaust gas is sent to the exhaust gas storage device to condition the low calorific value exhaust gas stored in the exhaust gas storage device.

[0017] As a preferred technical solution of the present invention, fuel gas is used to condition the low calorific value exhaust gas stored in the exhaust gas storage device.

[0018] As a preferred technical solution of the present invention, when the waste gas storage device is fully loaded, the waste gas is selectively sent to a ground flare or an incineration device based on the result of the calorific value detection.

[0019] As a preferred technical solution of the present invention, the steam generated by the waste heat recovery device is supplied to the flare burner for smoke elimination.

[0020] Compared with the prior art, the present invention has at least the following beneficial effects:

[0021] (1) The present invention provides a system device and system method for comprehensive waste gas treatment in the entire plant. The system device and system method perform online monitoring and classification of discharged waste gas according to calorific value, and execute different treatment processes according to the classification results, thereby ensuring that the waste gas of all emission conditions adopts the most appropriate treatment process, thereby improving the comprehensive treatment efficiency of the waste gas in the entire plant and reducing pollutant emissions;

[0022] (2) The present invention provides a comprehensive waste gas treatment system and method for the entire plant. The system and method use a waste gas storage device to collect low calorific value waste gas, pressurize it, and then supply it to the permanent lamp of the ground torch, thereby minimizing the use of ground torch devices or incineration devices to treat low calorific value waste gas, reducing fuel gas consumption, and lowering enterprise operating costs;

[0023] (3) The present invention provides a comprehensive waste gas treatment system and method for the entire plant. The system and method use the collected low-calorific value waste gas as fuel gas for the ever-burning lamp, reducing the fuel gas consumption of the ever-burning lamp and further reducing the operating costs of the enterprise. Based on a set of 1000t / h open ground flare, about 2000 cubic meters of fuel gas can be saved every day. The ever-burning lamp adopts premixed combustion, which has a higher purification rate for waste gas than ordinary flare devices.

[0024] (4) The present invention provides a comprehensive waste gas treatment system and method for the entire plant. The system and method use low calorific value waste gas as the fuel gas for the ever-burning lamp. Since the low calorific value waste gas has a low carbon content, it can reduce the carbon deposition and blockage caused by incomplete combustion of conventional fuel gas, thereby extending the service life of the flare system.

[0025] (5) The present invention provides a system device and system method for comprehensive waste gas treatment in the entire plant. The system device and system method preferentially supply the steam generated by the waste heat recovery device connected to the incineration device to the ground torch for smokeless combustion, thereby improving the combustion efficiency of the ground torch and reducing pollutant emissions. The remaining steam is incorporated into the steam pipeline network of the entire site. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a schematic diagram of the structure of the comprehensive waste gas treatment system for the entire plant provided in Example 2 of the present invention;

[0027] Figure 2a and 2b A schematic diagram of the structure of an open ground flare in a comprehensive plant exhaust gas treatment system device provided in Example 2 of the present invention;

[0028] Figure 3 Schematic diagram of the structure of the open ground flare in the comprehensive waste gas treatment system for the entire plant provided in Example 2 of the present invention

[0029] In the figure, 1-flow meter, 2-calorific value meter, 3-liquid separation tank, 4-low calorific value gas cabinet, 5-compressor, 6-water seal tank, 7-open ground flare, 8-incineration device (with waste heat recovery device), 9-flue gas treatment device, 10-chimney, 11a-low calorific value ever-burning lamp adjacent to the radiation protection fence, 11b-low calorific value ever-burning lamp inside the flare burner array, 12-torch burner, 13-radiation protection fence, 14-wind shield, 15-air inlet.

[0030] The present invention is further described in detail below. However, the following examples are merely simplified examples of the present invention and do not represent or limit the scope of protection of the present invention. The scope of protection of the present invention shall be subject to the claims. DETAILED DESCRIPTION

[0031] The technical solution of this application is further explained below through specific implementation methods.

[0032] A specific embodiment of the present invention provides a comprehensive waste gas treatment system for the entire plant, the system comprising a waste gas pipeline, a calorific value detection component being provided on the waste gas pipeline, the waste gas pipeline being divided into two branches, one being connected to the fuel inlet of the ground flare, and the other being connected to the incineration device;

[0033] The exhaust gas pipeline is further connected to the gas inlet of the exhaust gas storage device, and the gas outlet of the exhaust gas storage device is connected to the fuel inlet of the ground flare.

[0034] In this invention, the system and method monitor and classify exhaust gas online based on calorific value. Different treatment processes are implemented based on the classification results, ensuring that the most appropriate treatment process is used for exhaust gas from all emission conditions. This improves the overall waste gas treatment efficiency of the entire plant and reduces pollutant emissions. A waste gas storage device is used to collect and pressurize low-calorific value exhaust gas before supplying it to the ground flare's continuous light. This minimizes the need to use ground flare devices or incineration devices to treat low-calorific value exhaust gas, reduces fuel gas consumption, and lowers operating costs.

[0035] In a specific embodiment of the present invention, in addition to the calorific value detection component, a flow monitoring component can also be set on the exhaust gas pipeline to monitor and classify the discharged exhaust gas online according to the calorific value and flow rate to determine whether it is sent to the exhaust gas storage device, ground flare or incineration device.

[0036] In a specific embodiment of the present invention, a liquid separation device and a water seal device, such as a liquid separation tank and a water seal tank, may be sequentially provided on the pipeline that delivers the exhaust gas to the ground flare.

[0037] In a specific embodiment of the present invention, a pressurizing device, such as a compressor, is provided on the gas delivery pipeline of the waste gas storage device for pressurizing the waste gas.

[0038] In a specific embodiment of the present invention, a calorific value detection component is also provided on the gas delivery pipeline of the exhaust gas storage device to detect the calorific value of the conditioned exhaust gas to ensure that the calorific value of the conditioned exhaust gas meets the combustion requirements of the ground flare.

[0039] In a specific embodiment of the present invention, the system device is also provided with a fuel gas delivery pipeline, one of which is connected to the gas delivery pipeline of the waste gas storage device for tempering the waste gas with lower calorific value; the other is connected to the incineration device to supply fuel to the incineration device to ensure the processing temperature of the incineration device.

[0040] In a specific embodiment of the present invention, the steam outlet of the waste heat recovery device is also connected to the steam network for reusing the steam.

[0041] In a specific embodiment of the present invention, the flue gas outlet of the waste heat recovery device is connected to the flue gas treatment device and the chimney, so as to discharge the flue gas generated by the incineration device.

[0042] In one embodiment of the present invention, the pilot lamp in the ground flare is a low calorific value pilot lamp, that is, the air volume of the pilot lamp is reduced on the basis of a conventional pilot lamp so that it can use low calorific value waste gas as fuel gas.

[0043] In this invention, because using low-calorific-value waste gas as fuel would weaken the flame rigidity of the pilot light, resulting in poor wind resistance, an elevated flare cannot be used for the flare system. Therefore, the present invention uses a ground flare. Compared to elevated flares, ground flares are shielded by ground-level buildings and radiation-proof fences, and the ambient wind speed within the flare is much lower than that of elevated flares. Therefore, the low-calorific-value pilot light is suitable.

[0044] In a specific embodiment of the present invention, the ground flare is preferably an open ground flare. When the maximum exhaust gas emission is small, a closed ground flare can also be used.

[0045] In a specific embodiment of the present invention, a wind shield is provided on the head of the ever-burning lamp adjacent to the radiation protection component, and the wind shield is provided with an air inlet hole.

[0046] In addition to the ambient wind speed, when the torch burners within the open ground flare are operating, the combustion zone temperature is extremely high. The high-temperature flue gas generated by the combustion, due to its reduced density, flows upward, creating a negative pressure within the combustion zone. Under this negative pressure, external air is drawn into the combustion zone through the gaps in the radiation shield and the top of the fence. At this point, the outermost pilot lights experience significant wind pressure (the greater the exhaust gas flow, the higher the combustion zone temperature, which in turn increases the wind pressure), primarily from the horizontal and lateral directions. To prevent the flames of the low-calorific value pilot lights from being blown out, if pilot lights are installed in the burner ring closest to the radiation shield, these flames require special protection. Specifically, a wind shield should be installed at the pilot light head. To ensure that the secondary air distribution to the pilot light is not affected, the wind shield should have a sufficient number of air inlet holes. Once the cold air drawn in from the outside reaches the high-temperature zone, it is immediately carried upward by the high-temperature flue gas. Therefore, the pilot lights within the interior are virtually unaffected by this wind pressure, eliminating the need for a wind shield.

[0047] A specific embodiment of the present invention provides a comprehensive waste gas treatment system method for the entire plant. The system method uses the above-mentioned comprehensive waste gas treatment system device for the entire plant. The system method includes:

[0048] Using a calorific value detection component to detect the calorific value of the exhaust gas, and selecting whether to send the exhaust gas to the ground flare or incineration device according to the result of the calorific value detection;

[0049] According to the results of the calorific value detection, when the calorific value of the exhaust gas is lower than the calorific value requirement of the ground flare, the exhaust gas is sent to the exhaust gas storage device.

[0050] In a specific embodiment of the present invention, according to the results of calorific value detection, high calorific value waste gas is sent to the incineration device, low calorific value waste gas is sent to the ground torch, and waste gas with a calorific value lower than the calorific value requirement of the ground torch is sent to the waste gas storage device.

[0051] In one embodiment of the present invention, "high calorific value waste gas," "low calorific value waste gas," and "waste gas with a calorific value lower than the calorific value required for a ground flare" can be selected based on the model of the incinerator and the ground flare, and are not specifically limited herein. For example, high calorific value waste gas refers to a calorific value ≥7880 kJ / Nm3, and low calorific value waste gas refers to a calorific value <7880 kJ / Nm3.

[0052] In a specific embodiment of the present invention, when the waste gas storage device stores waste gas with a calorific value lower than the calorific value requirement of the ground flare, high calorific value waste gas can be used to temper it. When the amount of high calorific value waste gas is insufficient or there is no high calorific value waste gas, fuel gas can be used to temper it.

[0053] In a specific embodiment of the present invention, the steam generated by the waste heat recovery device connected to the incineration device is preferentially supplied to the flare burner for smoke elimination, thereby ensuring the exhaust gas purification rate of the ground flare and reducing pollutant emissions, and the excess steam is sent to the steam pipeline network of the entire plant.

[0054] To better illustrate the present invention and facilitate understanding of the technical solutions of the present invention, typical but non-limiting embodiments of the present invention are as follows:

[0055] Example 1

[0056] This embodiment provides a comprehensive waste gas treatment system for the entire plant, which includes a waste gas pipeline, a calorific value detection component provided on the waste gas pipeline, and two waste gas pipelines, one connected to the fuel inlet of the ground flare and the other connected to the incineration device;

[0057] The exhaust gas pipeline is further connected to the gas inlet of the exhaust gas storage device, and the gas outlet of the exhaust gas storage device is connected to the fuel inlet of the ground flare.

[0058] Example 2

[0059] This embodiment provides a comprehensive waste gas treatment system for the entire plant, the structure of which is as follows: Figure 1 As shown, the system device includes an exhaust gas pipeline, which is sequentially provided with a flow meter 1 and a calorific value meter 2. The exhaust gas pipeline after the calorific value meter 2 is divided into two branches, one of which is connected to the fuel inlet of an open ground flare 7. On this exhaust gas pipeline, a separator tank 3 and a water seal tank 6 are sequentially provided in the direction of exhaust gas flow in front of the open ground flare 7. The gas outlet of the separator tank 3 is connected to the gas inlet of the water seal tank 6, and the gas outlet of the water seal tank 6 is connected to the fuel inlet of the open ground flare 7.

[0060] The gas outlet of the water seal tank 6 is also connected to the gas inlet of the low calorific value gas cabinet 4. The exhaust gas delivery pipeline connected to the gas outlet of the low calorific value gas cabinet 4 is connected to the fuel inlet of the open ground flare 7. The exhaust gas delivery pipeline is provided with a compressor 5. The exhaust gas delivery pipeline after the compressor 5 is connected to the fuel gas pipeline. The fuel gas pipeline is connected to the fuel gas pipeline network of the entire plant. The exhaust gas delivery pipeline is provided with a second calorific value meter in the rear pipeline of the connection with the fuel gas pipeline.

[0061] Another branch of the exhaust gas pipeline is connected to the fuel inlet of the incineration device 8. The incineration device includes an incinerator and a waste heat recovery device. The steam outlet of the waste heat recovery device is connected to the flare burner 12 of the open ground flare 7. The steam outlet of the waste heat recovery device is also connected to the steam pipeline network of the entire plant. The flue gas outlet of the waste heat recovery device is connected to the flue gas inlet of the flue gas treatment device 9. The flue gas outlet of the flue gas treatment device 9 is connected to the chimney 10. The fuel inlet of the incineration device 8 is also connected to the fuel gas pipeline network of the entire plant through a gas pipeline.

[0062] The structure of the open ground flare 7 is as follows Figure 2a and Figure 2b As shown, the open ground torch 7 includes a torch burner array, which is composed of a torch burner 12. A low calorific value continuous lamp is set on one side of the torch burner 12. A radiation-proof fence 13 is set around the torch burner array. The head of the low calorific value continuous lamp 11a adjacent to the radiation-proof fence 13 is provided with a wind shield 14. The wind shield 14 is provided with an air inlet 15. Figure 3 As shown, the head of the low calorific value pilot lamp 11b inside the torch burner array is not provided with a wind shield.

[0063] Example 3

[0064] This embodiment provides a comprehensive waste gas treatment system method for the entire plant, using the comprehensive waste gas treatment system device provided in Example 2. The system method includes:

[0065] The waste gas enters the waste gas pipeline, and the flow rate and calorific value of the waste gas are detected by the flow meter 1 and the calorific value meter 2. According to the detection results of the flow rate and calorific value, the low calorific value waste gas is sent to the open ground torch 7 after passing through the separator tank 3 and the water seal tank 6 in sequence, and the high calorific value waste gas is sent to the incineration device 8. The waste gas with a calorific value lower than the calorific value requirement of the open ground torch 7 is sent to the low calorific value gas cabinet 4 after passing through the separator tank 3;

[0066] When the low calorific value waste gas is stored in the low calorific value gas cabinet 4, it is tempered with high calorific value waste gas, pressurized by the compressor 5, and tested by the second calorific value meter to meet the calorific value requirements before being sent to the open ground torch 7; if the high calorific value waste gas is insufficient or there is no high calorific value waste gas, the waste gas is pressurized by the compressor 5 and tempered with fuel gas from the fuel gas pipeline network of the entire plant. The tempered gas is tested by the second calorific value meter to meet the calorific value requirements and sent to the open ground torch 7;

[0067] When the high calorific value exhaust gas is insufficient to maintain the operating temperature of the incineration device 8, the fuel gas in the fuel gas pipeline network of the entire plant is used to supply fuel to the incineration device 8; the steam generated by the waste heat recovery device of the incineration device 8 is sent to the flare burner 12 for smoke elimination, and the excess steam is sent to the steam pipeline network of the entire plant. The flue gas generated by the incineration device 8 enters the flue gas treatment device 9 after waste heat recovery and is discharged through the chimney 10.

[0068] The comprehensive plant-wide waste gas treatment system method provided in Example 3 utilizes the comprehensive plant-wide waste gas treatment system apparatus provided in Example 2. Exhaust gas is classified according to calorific value detection results and different treatment processes are implemented based on the classification results. This ensures that the most appropriate treatment process is used for exhaust gas from all emission conditions, thereby improving the comprehensive treatment efficiency of the plant-wide waste gas and reducing pollutant emissions. A low-calorific value gas cabinet is installed to collect the lower-calorific value exhaust gas, condition it, and pressurize it before supplying it to the open-ground flare's continuous burner. This minimizes the use of ground flares or incineration devices to treat the lower-calorific value exhaust gas, reduces fuel gas consumption, and lowers enterprise operating costs. The open-ground flare uses a low-calorific value continuous burner, which collects the low-calorific value exhaust gas as fuel gas for the continuous burner, further reducing enterprise operating costs. Based on a 1,000 t / h open-ground flare system, approximately 2,000 cubic meters of fuel gas can be saved daily. The continuous burner utilizes premixed combustion, resulting in a higher exhaust gas purification rate than a flare system.

[0069] The applicant declares that the present invention is intended to illustrate the detailed structural features of the present invention through the above-described embodiments, but the present invention is not limited to the above-described detailed structural features. This does not mean that the present invention must rely on the above-described detailed structural features in order to be implemented. Those skilled in the art should understand that any improvements to the present invention, equivalent replacements for selected components, additions of auxiliary components, and selection of specific embodiments, etc., fall within the scope of protection and disclosure of the present invention.

[0070] The preferred embodiments of the present invention are described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the scope of protection of the present invention.

[0071] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any appropriate manner without contradiction. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations.

[0072] In addition, the various embodiments of the present invention may be arbitrarily combined, and as long as they do not violate the concept of the present invention, they should also be regarded as the contents disclosed by the present invention.

Claims

1. A comprehensive waste gas treatment system for the entire plant, characterized in that: The system device includes an exhaust gas pipeline, on which a calorific value detection component is provided. The exhaust gas pipeline is divided into two branches, one of which is connected to the fuel inlet of the ground flare and the other is connected to the incineration device; The exhaust gas pipeline is also connected to the gas inlet of the exhaust gas storage device, and the gas outlet of the exhaust gas storage device is connected to the fuel inlet of the ground flare; The ground flare includes a flare burner array, and a radiation protection component is provided on the periphery of the flare burner array; A permanent lamp is provided on one side of the torch burner; the permanent lamp is a low calorific value permanent lamp.

2. The system device according to claim 1, characterized in that The head of the pilot lamp of the torch burner adjacent to the radiation protection component is provided with a wind shield, and the wind shield is provided with an air inlet hole.

3. The system device according to claim 1, characterized in that The incineration device is connected to a waste heat recovery device, and a steam outlet of the waste heat recovery device is connected to the flare burner.

4. A comprehensive waste gas treatment system method for the entire plant, characterized in that: The system method uses the plant-wide exhaust gas comprehensive treatment system device according to any one of claims 1 to 3, and the system method includes: Using the calorific value detection component to detect the calorific value of the exhaust gas, and selecting to send the exhaust gas to the ground flare or incineration device according to the result of the calorific value detection; According to the result of the calorific value detection, when the calorific value of the exhaust gas is lower than the calorific value requirement of the ground flare, the exhaust gas is sent to the exhaust gas storage device.

5. The system method according to claim 4, characterized in that: According to the result of the calorific value detection, the high calorific value exhaust gas is sent to the exhaust gas storage device, and the low calorific value exhaust gas stored in the exhaust gas storage device is conditioned.

6. The system method according to claim 4, characterized in that: The low calorific value exhaust gas stored in the exhaust gas storage device is conditioned by using fuel gas.

7. The system method according to claim 4, characterized in that: When the waste gas storage device is fully loaded, the waste gas is sent to the ground flare or incineration device according to the result of the calorific value detection.

8. The system method according to claim 4, characterized in that: The steam generated by the waste heat recovery device is supplied to the flare burner for smoke elimination.

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