A desulfurization foaming online monitoring system and an online monitoring method

Abstract

The application discloses a desulfurization foaming online monitoring system and an online monitoring method. The desulfurization foaming online monitoring system comprises a desulfurization device, a desulfurization solution regeneration device, a controller and a bubble inhibitor automatic adding device. The rich liquid outlet end of the desulfurization device is communicated with the feeding end of the desulfurization solution regeneration device. The poor liquid outlet end of the desulfurization solution regeneration device is communicated with the desulfurization solution feeding end of the desulfurization device. The bubble inhibitor automatic adding device is communicated with the desulfurization device and the desulfurization solution regeneration device. The desulfurization device comprises an absorption tower and a first differential pressure transmitter for measuring the pressure difference between the upper liquid level and the lower liquid level in the tower kettle of the absorption tower. The first differential pressure transmitter and the bubble inhibitor automatic adding device are both signal connected with the controller. The bubble inhibitor automatic adding device is started and the bubble inhibitor is added to the desulfurization device. The operation basis and time are provided for the operator to predict and treat the desulfurization solution foaming in advance, so that the number of device shutdowns is reduced.

Description

Technical Field

[0001] This invention relates to the field of natural gas purification technology, specifically to an online monitoring system and method for desulfurization foaming. Background Technology

[0002] Raw natural gas is desulfurized and dehydrated before being exported as finished natural gas. Desulfurization units are commonly used to achieve natural gas desulfurization, industrial process gas desulfurization, and qualified discharge of tail gas. They are widely used in industries such as petroleum, chemical, and thermal power generation.

[0003] The desulfurization unit removes hydrogen sulfide, organic sulfur, and some carbon dioxide from the raw natural gas, and is a key device for ensuring the qualified export of the finished natural gas. In the desulfurization unit, the desulfurization solution is recycled through processes such as flash evaporation, filtration, and regeneration. During operation, various additives from upstream well sites and degradation products generated during solution recycling can cause foaming and liquid blockage in the desulfurization solution.

[0004] Solution foaming is a common production anomaly in desulfurization units, most notably in the desulfurization and regeneration towers. After foaming occurs, operators need to adjust unit operations such as circulation rates, and manually add antifoaming agents to control and reduce the degree of foaming. During operation, whether the desulfurization solution foams, the degree of foaming, and the timing and amount of antifoaming agent addition require operators to judge based on changes in relevant parameters of the desulfurization unit. Therefore, the timeliness of handling desulfurization solution foaming is closely related to the operator's experience and sense of responsibility. Untimely handling of desulfurization solution foaming can lead to fluctuations in the desulfurization unit, resulting in substandard natural gas quality; severe foaming can cause serious liquid backflow leading to tower overflow, and in severe cases, can cause accidents such as cross-pressure and interlocking shutdowns, resulting in natural gas venting and combustion, wasting energy, and causing severe liquid carryover in the natural gas, further exacerbating the loss of desulfurization solution.

[0005] The implementation of the "Natural Gas" standard (GB 17820-2018) has significantly increased the requirements for hydrogen sulfide and total sulfur content in natural gas quality indicators. Coupled with stricter environmental protection requirements, the existing manual methods of handling solution foaming can no longer meet the refined operation requirements of desulfurization units that demand high-quality products and stringent environmental protection standards. Summary of the Invention

[0006] The technical problem to be solved by the present invention is the aforementioned problem existing in the current method of manually adding antifoaming agents.

[0007] The primary objective is to provide an online monitoring system for desulfurization foaming, comprising a desulfurization unit, a desulfurization solution regeneration unit, a controller, and an automatic antifoaming agent addition device. The rich solution outlet of the desulfurization unit is connected to the feed end of the desulfurization solution regeneration unit, the lean solution outlet of the desulfurization solution regeneration unit is connected to the desulfurization solution feed end of the desulfurization unit, and the automatic antifoaming agent addition device is connected to both the desulfurization unit and the desulfurization solution regeneration unit.

[0008] The desulfurization device includes an absorption tower and a first differential pressure transmitter for measuring the pressure difference between the upper and lower liquid levels in the bottom of the absorption tower. The signals from the first differential pressure transmitter and the automatic foam inhibitor addition device are both connected to the controller.

[0009] When the above technical solution is adopted, the above-mentioned online monitoring system for desulfurization foaming is mainly used to realize online monitoring and judgment of the foaming of the desulfurization unit solution, and automatically add antifoaming agent through the controller according to the foaming trend, so as to avoid accidents such as unqualified product natural gas quality, natural gas venting, unit pressure cross-pressure, interlock shutdown, and equipment failure caused by the untimely adjustment of the desulfurization solution foaming operation.

[0010] As one possible design, the desulfurization solution regeneration device includes a regeneration tower and a second differential pressure transmitter for measuring the pressure difference between the upper and lower liquid levels in the regeneration tower bottom. The signal from the second differential pressure transmitter is connected to the controller. The differential pressure transmitter measures the change in differential pressure between the upper and lower liquid levels in the tower bottom, and the foaming trend is determined by the change in differential pressure, which is used to control the automatic addition of antifoaming agent.

[0011] As one possible design, the absorber reboiler is equipped with a first field level gauge for measuring the upper liquid level and a second field level gauge for measuring the lower liquid level. The measuring range of the first differential pressure transmitter is the distance between the lower pressure taps of the first and second field level gauges. There may be no other field level gauges between the first and second field level gauges, or there may be one or more field level gauges.

[0012] As one possible design, the regeneration tower reboiler is equipped with a third field level gauge for measuring the upper liquid level and a fourth field level gauge for measuring the lower liquid level. The measuring range of the second differential pressure transmitter is the distance between the lower pressure taps of the third and fourth field level gauges. There may be no other field level gauges between the third and fourth field level gauges, or there may be one or more field level gauges.

[0013] As one possible design, the automatic antifoaming agent addition device includes an antifoaming agent conveying device and a desulfurization solution low-level device. The discharge end of the antifoaming agent conveying device and the discharge end of the desulfurization solution low-level device are connected, and a solenoid valve is respectively installed on the connecting pipeline. An expansion pipe is installed at the connection point. The expansion pipe is connected to both the desulfurization device and the desulfurization solution regeneration device, and a solenoid valve is respectively installed on the connecting pipeline. Preferably, the desulfurization solution low-level device includes a desulfurization solution low-level tank. The desulfurization solution low-level tank is connected to the bottom return pipeline of the expansion pipe, and a solenoid valve is installed on the connecting pipeline. The desulfurization solution low-level tank is also equipped with a vertical pump. The discharge end of the vertical pump is connected to the expansion pipe, and a solenoid valve is installed on the connecting pipeline.

[0014] By controlling the opening and closing of these solenoid valves, and the starting or stopping of the vertical pump and metering pump, the antifoaming agent can be added in advance. Using the desulfurization solution as a carrier, the antifoaming agent is effectively transported to the absorption tower or the desulfurization solution regeneration tower, effectively preventing the occurrence of foaming.

[0015] As one possible design, the antifoaming agent conveying device includes an antifoaming agent storage tank, and a metering pump is installed on the outlet pipeline of the antifoaming agent storage tank. The discharge end of the metering pump is connected to the expansion pipe.

[0016] As one possible design, the expansion tube is connected to a vent pipe, the vent pipe is equipped with a solenoid valve, and the expansion tube is also equipped with a pressure transmitter.

[0017] As one possible design, a desulfurization flash evaporation device and a system device that are interconnected are also provided between the discharge end of the desulfurization device and the feed end of the solution regeneration device, with the desulfurization flash evaporation device connected to the discharge end of the desulfurization device.

[0018] The second objective of this invention is to provide an online monitoring method for desulfurization solution foaming, characterized in that it is implemented based on the aforementioned online monitoring system for desulfurization foaming;

[0019] ΔP1 is calculated based on P = ρgh within the measurement range of the first differential pressure transmitter. 计 The value is calculated using the rate of change ΔP1 of the measured value ΔP1 from the first differential pressure transmitter. The calculation formula is as follows:

[0020] ΔP1%=(ΔP1-ΔP1 计 ) / ΔP1 计 ×100%(I)

[0021] Where: ρ is the theoretical density of the solution in the absorption tower under absorption conditions, in kg / m3;

[0022] g is the acceleration due to gravity, 9.8 m / s². 2 ;

[0023] h represents the height inside the upper and lower ports of the first differential pressure transmitter, in meters.

[0024] When ΔP1% ≥ 5% or ΔP1% change rate ≥ 1% / second, the automatic foam inhibitor addition device is activated and adds foam inhibitor to the desulfurization device.

[0025] As one possible design, ΔP2 corresponding to the measurement range of the second differential pressure transmitter is calculated according to P = ρgh. 计 The value is calculated using the rate of change ΔP2 of the measured value ΔP2 from the second differential pressure transmitter. The calculation formula is as follows:

[0026] ΔP2%=(ΔP2-ΔP2 计 ) / ΔP2 计 ×100% (II)

[0027] Where: ρ is the theoretical density of the solution in the regeneration tower under regeneration conditions, in kg / m3;

[0028] g is the acceleration due to gravity, 9.8 m / s². 2 ;

[0029] h represents the height inside the upper and lower ports of the second differential pressure transmitter, in meters.

[0030] When ΔP2% ≤ -10% or ΔP2% change rate ≥ 1% / second, and the antifoaming agent addition of the desulfurization device is not started, the automatic antifoaming agent addition device is started and adds antifoaming agent to the desulfurization solution regeneration device.

[0031] As one possible design, the specific steps for starting the automatic foam inhibitor addition device are as follows:

[0032] When the automatic foam inhibitor dosing device receives a start command from the controller, it performs a check of the start conditions.

[0033] When the start-up conditions are met, start the vertical pump and open the solenoid valve on the return pipeline between the desulfurization solution low-level tank and the expansion pipe, and open the solenoid valve on the connecting pipeline between the vertical pump and the expansion pipeline. After 60 seconds, close the solenoid valve on the return pipeline between the desulfurization solution low-level tank and the expansion pipe.

[0034] When the pressure transmitter reaches 0.4 MPa, stop the vertical pump and close the solenoid valve connected to the vertical pump, while opening the solenoid valve on the vent pipe.

[0035] When the pressure transmitter pressure is zero, start the metering pump and open the solenoid valve on the connecting pipeline between the metering pump and the amplifier pipe. When the output of the metering pump reaches the set value, stop the metering pump and close the solenoid valve on the vent pipe and the solenoid valve on the connecting pipeline between the metering pump and the amplifier pipe.

[0036] Start the vertical pump and open the solenoid valve on the connecting pipeline between the desulfurization unit and the expansion pipe, or open the solenoid valve on the connecting pipeline between the desulfurization solution regeneration unit and the expansion pipe, and start the timer at the same time.

[0037] When the 5-minute timer ends, stop the vertical pump and close the solenoid valve on its discharge end connecting pipeline, and at the same time open the solenoid valve on the return pipeline between the desulfurization solution low-level tank and the bottom of the expansion pipe.

[0038] When the pressure transmitter pressure is zero, close the solenoid valve on the return pipeline between the desulfurization solution low-level tank and the bottom of the expansion pipe;

[0039] Preferably, the starting conditions include the metering pump not running and all solenoid valves on the pipeline connected to the expansion pipe not being energized;

[0040] Preferably, the set values ​​of ΔP1%, ΔP1% change rate, ΔP2%, and ΔP2% change rate are all adjustable.

[0041] The beneficial effects of this invention are as follows:

[0042] 1. The online monitoring system for desulfurization foaming enables online monitoring and judgment of solution foaming, and can automatically add antifoaming agent, reducing safety risks and improving work efficiency.

[0043] 2. The online monitoring system for desulfurization foaming enables online monitoring and judgment of solution foaming. It proposes specific judgment index values ​​(pressure change rate or pressure change percentage as the start index, and the amount of antifoaming agent added as the stop index). This solves the problems of existing solution foaming systems that require manual sampling and analysis, and the addition of antifoaming agent based on experience, which are characterized by rough operation, lag, and untimely adjustment.

[0044] 3. The online monitoring system for desulfurization foaming enables online monitoring and judgment, providing operators with operational basis and time for predicting and handling the foaming of desulfurization solution in advance, thereby reducing the number of unit shutdowns.

[0045] 4. The automatic antifoaming agent dispensing system enables precise operation, replacing manual dispensing, reducing the labor intensity of operators, and improving work efficiency; at the same time, the timely dispensing of antifoaming agent can effectively reduce the consumption of antifoaming agent.

[0046] 5. The desulfurization foaming online monitoring system disclosed in this invention is applicable to existing natural gas desulfurization devices, industrial tail gas desulfurization devices, and tail gas treatment devices. It can be widely used in industries such as petroleum, chemical, and thermal power generation, and has a wide range of applications and good application prospects. Attached Figure Description

[0047] To more clearly illustrate the technical solutions of the exemplary embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly described below. It should be understood that the following drawings only show some embodiments of the present invention and should not be considered as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort. In the drawings:

[0048] Figure 1 This is a schematic diagram of the online monitoring system for desulfurization and foaming in an embodiment of the present invention;

[0049] Figure 2 This is the foaming logic startup diagram of the desulfurization device in this embodiment of the invention;

[0050] Figure 3 This is the foaming logic startup diagram of the desulfurization solution regeneration device in this embodiment of the invention;

[0051] Figure 4 This is a flowchart of the automatic foam inhibitor dispensing control program in an embodiment of the present invention.

[0052] The attached diagram shows the markings and corresponding component names:

[0053] 1-Absorber; 2-Flash tank; 3-System unit; 4-Regeneration tower; 5-First differential pressure transmitter; 6-Second differential pressure transmitter; 7-Circulation pump; 8-Expanding pipe; 9-Desulfurization solution low-level tank; 10-Vertical pump; 11-Antifoaming agent storage tank; 12-Metering pump; 13-First solenoid valve; 14-Second solenoid valve; 15-Third solenoid valve; 16-Fourth solenoid valve; 17-Fifth solenoid valve; 18-Sixth solenoid valve; 19-First field level gauge; 20-Second field level gauge; 21-Third field level gauge; 22-Fourth field level gauge; 23-Pressure transmitter. Detailed Implementation

[0054] 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.

[0055] It should be noted that when a component is referred to as being "fixed to" or "set on" another component, it can be directly on or indirectly on that other component. When a component is referred to as being "connected to" another component, it can be directly connected to or indirectly connected to that other component.

[0056] 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 indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified. "Several" means one or more, unless otherwise explicitly specified.

[0057] In the description of this invention, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0058] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0059] The inventors of this invention have discovered that existing natural gas desulfurization units primarily rely on manual sampling and analysis to monitor foaming during operation. The decision to add antifoaming agents is based on the analysis results. This method requires experienced operators, and inaccurate judgments leading to foaming can cause minor issues like unit fluctuations and substandard natural gas quality. Severe foaming can result in significant liquid backflow and tower overflow, or even major accidents such as cross-pressure and interlocking shutdowns, leading to venting and burning of natural gas, wasting energy. It also results in excessive liquid carryover in the natural gas, exacerbating desulfurization solution losses. Furthermore, the existing method of manual analysis and antifoaming agent addition leads to a lag in adjusting the desulfurization unit's solution foaming. Once foaming occurs, the sulfur content in the purified natural gas will struggle to meet new product standards, resulting in large-scale venting and burning of sulfur-containing natural gas, which fails to meet environmental protection requirements.

[0060] Based on the above problems, the inventors of this invention further conceived of changing the existing method of manually analyzing and adding antifoaming agents to automatic addition through program control. However, how to set the conditions for starting and stopping the program becomes crucial to whether the addition of antifoaming agents can be achieved effectively and in a timely manner, thereby avoiding the occurrence of foaming.

[0061] The inventors of this invention accidentally discovered that the rate of change of pressure or the speed of change of the rate of change in the desulfurization unit and the regeneration unit is an important condition for starting the addition of antifoaming agent, and that quantitative addition of antifoaming agent is a condition for stopping the addition. Furthermore, the desulfurization solution is set as a carrier to inject the antifoaming agent into the desulfurization unit or the regeneration unit, so as to achieve uniform addition of antifoaming agent and reduce the possibility of foaming in time.

[0062] like Figure 1 As shown, this embodiment of the invention provides an online monitoring system for desulfurization foaming. Figure 1 As shown, the online monitoring system includes a desulfurization unit, a desulfurization solution regeneration unit, a controller, and an automatic antifoaming agent addition device. The rich solution outlet of the desulfurization unit is connected to the feed end of the desulfurization solution regeneration unit, and the lean solution outlet of the desulfurization solution regeneration unit is connected to the desulfurization solution feed end of the desulfurization unit. The automatic antifoaming agent addition device is connected to both the desulfurization unit and the desulfurization solution regeneration unit.

[0063] The desulfurization device includes an absorption tower 1 and a first differential pressure transmitter 5 for measuring the pressure difference between the upper and lower liquid levels in the bottom of the absorption tower 1. The first differential pressure transmitter 5 and the automatic antifoaming agent addition device are both connected to the controller signal.

[0064] The desulfurization solution regeneration device includes a regeneration tower 4 and a second differential pressure transmitter 6 for measuring the pressure difference between the upper and lower liquid levels in the regeneration tower 4. The second differential pressure transmitter 6 is signal-connected to the controller.

[0065] The automatic antifoaming agent addition device is activated by controlling the rate of change of differential pressure or the speed of change of the rate of change in the desulfurization unit or desulfurization solution regeneration unit, thereby achieving the function of adding antifoaming agent, defoaming, and automatic addition of antifoaming agent.

[0066] In practical applications, the absorber 1 is equipped with a first field level gauge 19 for measuring the upper liquid level and a second field level gauge 20 for measuring the lower liquid level. The measuring range of the first differential pressure transmitter 5 is the distance between the lower pressure port of the first field level gauge 19 and the lower pressure port of the second field level gauge 20.

[0067] In practical applications, the regeneration tower 4 is equipped with a third field level gauge 21 for measuring the upper liquid level and a fourth field level gauge 22 for measuring the lower liquid level. The measuring range of the second differential pressure transmitter 6 is the distance between the lower pressure tap of the third field level gauge 21 and the lower pressure tap of the fourth field level gauge 22.

[0068] As one possible implementation, since the amount of antifoaming agent added under normal circumstances is very small compared to the amount of lean or rich liquor, directly adding the antifoaming agent to regeneration tower 4 or absorption tower 1 will result in uneven distribution of the antifoaming agent or it floating on the surface of the liquid, thus failing to achieve an effective defoaming effect. Figure 1 As shown, the aforementioned automatic antifoaming agent addition device includes an antifoaming agent conveying device and a desulfurization solution conveying device. The discharge end of the desulfurization solution conveying device is connected to the discharge end of the desulfurization solution conveying device. Specifically, an expansion pipe 8 can be installed, which is connected to both the discharge end of the desulfurization solution conveying device and the discharge end of the desulfurization solution conveying device. The expansion pipe 8 is used to mix the antifoaming agent and the desulfurization solution evenly.

[0069] As one possible implementation method, such as Figure 1 As shown, the antifoaming agent delivery device includes an antifoaming agent storage tank 11, a metering pump 12 is connected to the outlet pipeline of the antifoaming agent storage tank 11, and a second solenoid valve 14 (SDV2) is installed on the outlet pipeline of the metering pump 12. This pipeline is connected to the expansion pipe 8.

[0070] like Figure 1 As shown, the desulfurization solution conveying device includes a desulfurization solution low-level tank 9, a vertical pump 10 connected to the desulfurization solution low-level tank 9, the vertical pump 10 and the expansion pipe 8 are connected, and a first solenoid valve 13 (SDV1) is installed on the pipeline connecting the two.

[0071] The desulfurization solution low-level tank 9 and the expansion pipe 8 are connected at the bottom, and a fourth solenoid valve 16 (SDV4) is installed on the return pipeline connecting the two.

[0072] For safety, the expansion pipe 8 is connected to a vent pipe, and a third solenoid valve 15 (SDV3) is installed on the vent pipe.

[0073] A fifth solenoid valve 17 (SDV5) is installed on the pipeline connecting the discharge end of the expansion pipe 8 and the regeneration tower 4; a sixth solenoid valve 18 (SDV6) is installed on the pipeline connecting the discharge end of the expansion pipe 8 and the solution circulation pump 7 used for lean liquor circulation.

[0074] In one possible implementation, such as Figure 1As shown, a system device 3 is also provided between the aforementioned desulfurization unit and the aforementioned desulfurization solution regeneration unit. System device 3 mainly recovers the heat from the regenerated desulfurization solution, thereby reducing the energy consumption of the entire desulfurization process. The lean solution generated by the desulfurization solution regeneration unit and the rich solution generated by the desulfurization unit exchange heat. System device 3 may include a filtration device, a heat exchange device, and a cooling device connected in sequence. The filtration device filters the rich solution to remove solid impurities and degradation products, preventing scaling and other damage to the heat exchange device. The cooling device cools the lean solution that has not reached the required temperature, allowing it to be returned to the desulfurization unit for recycling.

[0075] In one possible implementation, such as Figure 1 As shown, a flash evaporation device, such as a flash tank 2, can also be installed between the aforementioned desulfurization device and system device 3. This device is used to depressurize and flash-evaporate the gas entrained in the rich liquid discharged from the bottom of the absorption tower 1.

[0076] In practical applications, such as Figure 1 As shown, the lean liquor produced by regeneration tower 4 is cooled and then returned to absorption tower 1 via a conventional centrifugal pump, which can be referred to as circulation pump 7. The feed end of the centrifugal pump can be connected to the discharge end of the aforementioned automatic antifoaming agent addition device. Timely connection and disconnection can be achieved by installing a solenoid valve on the connected pipeline.

[0077] In practical applications, the parameters of the enlarged pipe can be as follows: DN50~DN80, length 200~500mm, 20# seamless steel pipe.

[0078] The types of level gauges actually used in the field mentioned above may include, but are not limited to, glass level gauges, glass tube level gauges, magnetic float level gauges, etc.

[0079] The aforementioned first differential pressure transmitter 5 and second differential pressure transmitter 6 can both be ordinary differential pressure transmitters or diaphragm-type differential pressure transmitters. The aforementioned controller can be, but is not limited to, a microcontroller, PLC, RTU, DCS, SIS, etc., with programmable control functions.

[0080] This invention also provides an online monitoring method based on the aforementioned online monitoring system for desulfurization and foaming.

[0081] This includes three aspects: monitoring and judging foaming in the absorber solution, monitoring and judging foaming in the regeneration tower solution, and automatic addition of antifoaming agents; among them, monitoring and judging foaming in the absorber solution is as follows:

[0082] like Figure 2 As shown, ΔP1 corresponding to the measurement range of the first differential pressure transmitter is calculated according to P = ρgh. 计 The value is calculated using the measured value ΔP1 from the first differential pressure transmitter 5, and its rate of change ΔP1 is calculated using the following formula:

[0083] ΔP1%=(ΔP1-ΔP1 计 ) / ΔP1 计 ×100%(I)

[0084] Where: ρ is the theoretical density of the solution in the absorption tower under absorption conditions, in kg / m3;

[0085] g is the acceleration due to gravity, 9.8 m / s². 2 ;

[0086] h represents the height inside the upper and lower ports of the first differential pressure transmitter 5, in meters.

[0087] When ΔP1% ≥ 5% or ΔP1% change rate ≥ 1% / second, the automatic foam inhibitor addition device is activated and adds foam inhibitor to the desulfurization device.

[0088] It should be noted that: when the measured value ΔP1 is working, the liquid level between the upper and lower pressure taps is full, and h remains unchanged. However, the foaming of the solution will cause a change in the solution density, which will lead to a change in ΔP1.

[0089] In practical applications, the ΔP1% change rate can be adjusted accordingly based on the different density changes during foaming of different desulfurization solutions to meet actual needs.

[0090] The monitoring and judgment of foaming in the regeneration tower solution are as follows:

[0091] like Figure 3 As shown, ΔP2 is calculated within the measurement range of the second differential pressure transmitter 6 according to P = ρgh. 计 The value is calculated using the measured value ΔP2 from the second differential pressure transmitter 6, and its rate of change ΔP2 is calculated using the following formula:

[0092] ΔP2%=(ΔP2-ΔP2 计 ) / ΔP2 计 ×100% (II)

[0093] Where: ρ is the theoretical density of the solution in the regeneration tower under absorption conditions, in kg / m3;

[0094] g is the acceleration due to gravity, 9.8 m / s². 2 ;

[0095] h represents the height of the upper and lower input ports of the second differential pressure transmitter 6, in meters (m).

[0096] like Figure 3 As shown, when ΔP2% ≤ -10% or ΔP2% change rate ≥ 1% / second, and the antifoaming agent addition program of the aforementioned desulfurization device is not started, the automatic antifoaming agent addition device is started and adds antifoaming agent to the desulfurization solution regeneration device.

[0097] It should be noted that: when the measured value ΔP2 is working, the liquid level between the upper and lower pressure taps is full, and h remains unchanged. However, the foaming of the solution will cause a change in the solution density, which will lead to a change in ΔP2.

[0098] In practical applications, the ΔP2% change rate can be adjusted accordingly based on the different density changes during foaming of different desulfurization solutions to meet actual needs.

[0099] In practical applications, the set values ​​of ΔP1%, ΔP1% change rate, ΔP2%, and ΔP2% change rate are all adjustable.

[0100] The automatic foam inhibitor dispensing process is detailed below:

[0101] like Figure 1 and Figure 4 As shown, it includes the following steps:

[0102] S1. When the automatic antifoaming agent addition device receives a start command from the controller indicating that antifoaming agent needs to be added to the desulfurization unit or desulfurization solution regeneration unit, i.e. Figure 4 Q1 or Q2 in the text;

[0103] S2. Check if the starting conditions are met. The starting conditions are: metering pump 12 is not started and SDV1-6 is not powered on.

[0104] S3. Start vertical pump 10, and open SDV1 and SDV4;

[0105] S4. Turn off SDV4 after 60 seconds;

[0106] S5. When the PT value of the pressure transmitter 23 on the expansion pipe 8 reaches 0.4 MPa, stop the vertical pump 10 and shut down SDV1;

[0107] S6. Open SDV3;

[0108] S6. When the PT value of the pressure transmitter 23 on the expansion pipe 8 is 0, start the metering pump 12 and open SDV6 (SDV5) according to Q1 (Q2); it should be noted that when the start command Q1 is used, SDV6 is opened; when the start command Q2 is used, SDV5 is opened.

[0109] S7. Start the timer for 5 minutes; the timer duration can be adjusted according to actual needs.

[0110] S8. Stop metering pump 12 and close SDV6 (SDV5); In this step, if the PT value of pressure transmitter 23 on expansion pipe 8 is greater than 0.6 MPa, an alarm will be triggered and interlock SDV3 will be opened;

[0111] S9. Open SDV4;

[0112] S10. When the PT value of the pressure transmitter 23 on the expansion pipe 8 is 0, shut down SDV4;

[0113] S11. Automatic antifoaming agent addition program ends.

[0114] 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.

Claims

1. An on-line monitoring system for foaming of a desulfurization solution, characterized in that, The desulfurization device, the desulfurization solution regeneration device, the controller and the anti-foaming agent automatic adding device are connected, the rich liquid outlet end of the desulfurization device and the feed end of the desulfurization solution regeneration device are communicated, the lean liquid outlet end of the desulfurization solution regeneration device and the desulfurization solution feed end of the desulfurization device are communicated, and the anti-foaming agent automatic adding device is communicated with the desulfurization device and the desulfurization solution regeneration device; The desulfurization device comprises an absorption tower and a first differential pressure transmitter for measuring the pressure difference between the upper and lower liquid levels in the tower kettle of the absorption tower, and the signals of the first differential pressure transmitter and the anti-foaming agent automatic adding device are connected to the controller; The desulfurization solution regeneration device comprises a regeneration tower and a second differential pressure transmitter for measuring the pressure difference between the upper and lower liquid levels in the tower kettle of the regeneration tower, and the signal of the second differential pressure transmitter is connected to the controller; The upper part of the tower kettle of the absorption tower is provided with a first field liquid level meter for measuring the upper liquid level and a second field liquid level meter for measuring the lower liquid level, and the measuring range of the first differential pressure transmitter is the distance between the lower pressure tapping port of the first field liquid level meter and the lower pressure tapping port of the second field liquid level meter; The upper part of the tower kettle of the regeneration tower is provided with a third field liquid level meter for measuring the upper liquid level and a fourth field liquid level meter for measuring the lower liquid level, and the measuring range of the second differential pressure transmitter is the distance between the lower pressure tapping port of the third field liquid level meter and the lower pressure tapping port of the fourth field liquid level meter; The anti-foaming agent automatic adding device comprises an anti-foaming agent conveying device and a desulfurization solution low position device, the outlet end of the anti-foaming agent conveying device and the outlet end of the desulfurization solution low position device are communicated, and an electromagnetic valve is arranged on the communication pipeline respectively, an expansion pipe is arranged at the communication position, the expansion pipe is communicated with the desulfurization device and the desulfurization solution regeneration device, and an electromagnetic valve and a one-way valve are arranged on the communication pipeline respectively; the desulfurization solution low position device comprises a desulfurization solution low position tank, the desulfurization solution low position tank is communicated with the bottom backflow pipeline of the expansion pipe, and an electromagnetic valve is arranged on the communication pipeline, and the desulfurization solution low position tank is further provided with a vertical pump, the outlet end of the vertical pump is communicated with the expansion pipe, and an electromagnetic valve is arranged on the communication pipeline.

2. The on-line monitoring system for foaming of desulfurization solution according to claim 1, characterized in that, The anti-foaming agent conveying device comprises an anti-foaming agent storage tank, a metering pump is arranged on the outlet pipeline of the anti-foaming agent storage tank, and the outlet end of the metering pump is communicated with the expansion pipe.

3. The on-line monitoring system for foaming of desulfurization solution according to claim 2, characterized in that, The expansion pipe is communicated with a venting pipe, the venting pipe is provided with an electromagnetic valve, and a pressure transmitter is further arranged on the expansion pipe.

4. The on-line monitoring system for foaming of desulfurization solution according to any one of claims 1 to 3, characterized in that, The outlet end of the desulfurization device and the feed end of the solution regeneration device are further provided with a desulfurization flash device and a system device which are communicated with each other; The system device is arranged to recover the heat of the desulfurization solution generated by regeneration, so as to reduce the energy consumption of the whole desulfurization process.

5. A method for on-line monitoring of foaming of a desulfurization solution, characterized by, The anti-foaming agent automatic adding device is started and adds anti-foaming agent to the desulfurization device when ΔP1%≥5% or the change rate of ΔP1%≥1% / second. According to The anti-foaming agent automatic adding device is started and adds anti-foaming agent to the desulfurization device when ΔP1%≥5% or the change rate of ΔP1%≥1% / second. corresponding ΔP1 in the measurement range of the first differential pressure transmitter 计 value, the change rate ΔP1% is calculated by the first differential pressure transmitter measurement value ΔP1, and the calculation formula is as follows: ΔP1%= (ΔP1- ΔP1 计 ) / ΔP1 计 × 100% (I) wherein: ​ is the theoretical density of the solution in the absorption tower under absorption conditions, in kg / m3 3 ; g is the acceleration due to gravity, 9.8 m / s 2 ; h H is the height in the upper and lower taps of the first differential pressure transmitter, in meters; ​ 6. The on-line monitoring method of a desulfurization solution according to claim 5, characterized in that, According to ​ corresponding ΔP2 in the measurement range of the second differential pressure transmitter 计 value, the change rate ΔP2% is calculated by the second differential pressure transmitter measurement value ΔP2, and the calculation formula is as follows: ΔP2% = (ΔP2 - ΔP2 计 ) / ΔP2 计 x 100% (II) wherein: ​ is the theoretical density of the solution in the regeneration column under regeneration conditions, in kg / m 3 ; g is the acceleration due to gravity, 9.8 m / s 2 ; h H is the height in the upper and lower taps of the second differential pressure transmitter, in meters; When ΔP2%≤-10% or ΔP2% change rate≥1% / second, and the anti-foaming agent addition of the desulfurization device is not started, the anti-foaming agent automatic addition device is started and anti-foaming agent is added to the desulfurization solution regeneration device.

7. The on-line monitoring method of a desulfurization solution according to claim 6, characterized in that, The specific steps of starting the anti-foaming agent automatic addition device are as follows: When the anti-foaming agent automatic addition device receives the starting command from the controller, the starting condition is checked; When the starting condition is met, the vertical pump is started and the electromagnetic valve on the return pipe between the desulfurization solution low tank and the bottom of the expansion pipe and the electromagnetic valve on the communication pipe between the vertical pump and the expansion pipe are opened, and the electromagnetic valve on the return pipe between the desulfurization solution low tank and the expansion pipe is closed after 60 seconds; When the pressure of the pressure transmitter reaches 0.4Mpa, the vertical pump is stopped and the electromagnetic valve connected with the vertical pump is closed, and the electromagnetic valve on the vent pipe is opened; When the pressure of the pressure transmitter is zero, the metering pump is started and the electromagnetic valve on the communication pipe between the metering pump and the expansion pipe is opened, and when the output of the metering pump reaches the set value, the metering pump is stopped and the electromagnetic valve on the vent pipe and the electromagnetic valve on the communication pipe between the metering pump and the expansion pipe are closed; The vertical pump is started and the electromagnetic valve on the communication pipe between the desulfurization device and the expansion pipe or the electromagnetic valve on the communication pipe between the desulfurization solution regeneration device and the expansion pipe is opened, and the timer is started at the same time; When the timer ends for 5 minutes, the vertical pump is stopped and the electromagnetic valve on the communication pipe connected with the discharge end is closed, and the electromagnetic valve on the return pipe between the desulfurization solution low tank and the bottom of the expansion pipe is opened at the same time; When the pressure of the pressure transmitter is zero, the electromagnetic valve on the return pipe between the desulfurization solution low tank and the bottom of the expansion pipe is closed; The starting condition includes that the metering pump is not running and the electromagnetic valve on the communication pipe with the expansion pipe is not powered on; The set values of ΔP1%, ΔP1% change rate, ΔP2%, and ΔP2% change rate can be adjusted.

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