CN-121979144-A - Energy efficiency optimization method and system for deslagging in coal gas debenzolization process

CN121979144ACN 121979144 ACN121979144 ACN 121979144ACN-121979144-A

Abstract

The application relates to the technical field of coal chemical industry technology, and discloses an energy efficiency optimization method and system for deslagging in a coal gas debenzolization process, wherein the method utilizes a reaction dynamics model to calculate the generation rate of wash oil residues and integrates the rate to obtain accumulated slag quantity; when the slag quantity reaches a threshold value, a mapping relation between slag discharge duration and target mass is established through a hydrodynamic model to realize quantitative slag discharge, a comprehensive emulsification risk index is established based on shearing and turbulence characteristics of pipeline pressure signals in the material conveying process, a flow control or thermal lean oil dilution mode is dynamically switched according to the comprehensive emulsification risk index, and a separation mass feedback self-adaptive correction risk judgment threshold value of a mechanical clarifying tank is utilized. According to the application, through the coupling of multiple physical field models and closed loop feedback, the quantitative control of the deslagging process and the emulsification inhibition of the conveying process are realized, and the separation efficiency and the operation stability of the system are improved.

Inventors

Ding Zuopu
LIU JINGNING
YANG ZHIGUI
ZHAO JINGPENG
Ma Yaoxiong
XU YAOHUI
Miao Changzhi
LIU WENBIN

Assignees

宁夏庆华煤化集团有限公司

Dates

Publication Date: 20260505
Application Date: 20260129

Claims (10)

1. An energy efficiency optimization method for deslagging in a coal gas debenzolization process is characterized by comprising the following steps: collecting operation parameters of a coal gas debenzolization system, calculating the instantaneous slag generation rate of circulating wash oil by utilizing a reaction dynamics model, and carrying out time integration on the instantaneous slag generation rate to obtain the current accumulated slag quantity; When the accumulated slag quantity reaches a preset slag discharging threshold, determining the target discharge quality of the current slag discharging, establishing a mapping relation between the opening time of a slag discharging valve and the target discharge quality based on a fluid mechanics model, converting the target discharge quality into the target opening time of the slag discharging valve by using the mapping relation, and controlling the opening time of the slag discharging valve to open the target opening time so as to quantitatively discharge slag-containing materials to a thin slag tank; Collecting pressure signals of an inlet conveying pipeline of a thin slag tank in real time in the conveying process of slag-containing materials, extracting characteristic components representing shearing and turbulence in the pressure signals to construct a comprehensive emulsification risk index, and executing a flow regulation strategy or a dilution decoupling strategy for the slag-containing materials according to the comprehensive emulsification risk index; And obtaining separation quality data of clear liquid at the outlet of the clarifying tank, and adaptively correcting a risk judgment threshold value of the comprehensive emulsification risk index for the next batch control according to the deviation of the separation quality data and a target value.
2. The energy efficiency optimization method for deslagging in a coal gas debenzolization process according to claim 1 is characterized by comprising the steps of collecting a crude benzene production rate to represent the production load of a coal gas debenzolization system and collecting a wash oil regeneration temperature to represent the reaction kinetic activity, inputting the crude benzene production rate and the wash oil regeneration temperature into a pre-built Arrhenius-type reaction kinetic equation, and calculating to obtain the instantaneous slag production rate of the circulating wash oil.
3. The energy efficiency optimization method for deslagging in the coal gas debenzolization process according to claim 1, wherein the mapping relation is constructed based on flow characteristics of a deslagging valve, and specifically comprises the steps of determining instantaneous mass flow through the deslagging valve according to real-time pressure difference before and after the deslagging valve and density parameters of slag-containing materials, and determining action duration of the deslagging valve according to the ratio of the target emission mass to the instantaneous mass flow.
4. A method for optimizing the energy efficiency of slag removal in a coal gas debenzolization process according to claim 3, said method further comprising: After the slag discharging valve is closed and the liquid level of the thin slag tank is stable, the actual slag discharging quality is reversely pushed by utilizing the geometric dimension and the liquid level increment of the thin slag tank, and the actual slag discharging quality is compared with the theoretical target quality; and when the two flow coefficients have deviation, adjusting the comprehensive flow coefficient in the fluid mechanics model to compensate the change of the flow capacity of the slag discharging valve.
5. The energy efficiency optimization method for deslagging in the coal gas debenzolization process according to claim 1 is characterized in that the extraction and construction of the characteristic components comprise the steps of separating a direct current component in a pipeline pressure signal as a static pressure difference component for representing average shearing stress of fluid against pipe wall friction, separating an alternating current component in the pipeline pressure signal as a dynamic turbulence component for representing turbulence pulsation intensity in the fluid, and the comprehensive emulsification risk index is formed by weighted superposition of the static pressure difference component and the dynamic turbulence component.
6. The energy efficiency optimization method for deslagging in a coal gas debenzolization process according to claim 1, wherein the flow regulation strategy or dilution decoupling strategy specifically comprises the following steps: Setting a safety threshold and a critical threshold, and dividing risks into a low risk interval, a medium risk interval and a high risk interval; Executing a flow regulation strategy targeting a maximum flow rate in the low risk interval; Executing a pressure stabilizing inhibition strategy aiming at inhibiting pressure fluctuation in the middle risk interval, and reducing turbulence intensity by limiting the opening degree and the change rate of the steam regulating valve; And executing the dilution decoupling strategy in the high-risk interval.
7. The energy efficiency optimization method for deslagging in a coal gas debenzolization process according to claim 6, wherein the dilution decoupling strategy specifically comprises: Cutting off or locking a steam source for conveying and opening a hot lean oil bypass valve connected to a lean slag tank to inject hot lean oil; And the dynamic viscosity and the solid content of the mixed materials in the tank are reduced by utilizing the dilution effect of the hot lean oil, so that the driving pressure difference and the shearing force required by fluid transportation are reduced until the comprehensive emulsification risk index is restored to a safe interval.
8. The energy efficiency optimization method for deslagging in a coal gas debenzolization process according to claim 1, wherein the self-adaptive correction adopts a batch control strategy, and the batch control strategy specifically comprises: taking the water content or slag content of clear liquid at the outlet of the clarifying tank as a key quality characteristic; if the key quality characteristics of the current batch are inferior to the process target value, the risk judgment threshold of the next batch is adjusted down so as to trigger the voltage stabilization inhibition strategy or the dilution decoupling strategy in advance; if the critical quality features are better than the process target values, the risk determination threshold for the next lot is maintained or relaxed.
9. The energy efficiency optimization method for deslagging in a coal gas debenzolization process according to claim 8, wherein a filtering mechanism with dead zone characteristics and a boundary constraint mechanism are introduced when the risk judgment threshold is adaptively corrected; the filtering mechanism is used for ignoring quality fluctuation of amplitude in the dead zone range and responding only when deviation exceeds the dead zone range; the boundary constraint mechanism is used for limiting the corrected risk judgment threshold value between a preset maximum value and a preset minimum value.
10. An energy efficiency optimization system for deslagging in a coal gas debenzolization process, characterized in that the system performs an energy efficiency optimization method for deslagging in a coal gas debenzolization process according to any one of claims 1 to 9, the system comprising: The field device assembly comprises a wash oil regenerator, a thin slag tank, a clarifying tank and an executing mechanism on a connecting pipeline, wherein the executing mechanism comprises a slag discharging valve positioned at the bottom of the wash oil regenerator, a steam regulating valve at the inlet of the thin slag tank and a hot lean oil bypass valve; A central control unit communicatively coupled to the field device assembly, configured with: The acquisition module is used for acquiring the production load and the temperature of the crude benzene working section as input variables and acquiring a real-time pipeline pressure signal of the conveying pipeline; the trigger module is used for operating the reaction dynamics model to monitor the slag accumulation state and controlling the slag discharge valve to perform quantitative slag discharge based on the hydrodynamic model; the conveying module extracts characteristic components based on the pipeline pressure signals, calculates a comprehensive emulsification risk index, and cooperatively adjusts the steam regulating valve and the hot lean oil bypass valve according to the comprehensive emulsification risk index to realize graded conveying under different risk grades; And the correction module is used for carrying out iterative correction on the risk judgment threshold value in the conveying module according to the separation quality data of the clarifying tank.

Description

Energy efficiency optimization method and system for deslagging in coal gas debenzolization process Technical Field The invention relates to the technical field of coal chemical industry processes, in particular to an energy efficiency optimization method and system for deslagging in a coal gas debenzolization process. Background In the crude benzene recovery section of the gas purification process, the wash oil is recycled as an absorbent. With the increase of the operation time, the high boiling point components and absorbed impurities in the wash oil undergo thermal condensation and polymerization reaction in the high temperature environment of the regenerator to form high-viscosity polymer residues. In order to maintain the absorption performance of the wash oil and prevent the system from being blocked, slag-containing materials at the bottom of the regenerator need to be discharged periodically and conveyed to a mechanical clarifying tank through a thin slag pot for separation treatment of oil, water and slag. The existing slag discharging control mainly depends on manual experience or a set fixed time interval to operate. However, the rate of slag formation during wash oil regeneration is not constant and is affected by non-linearities in the various variables of crude benzene production load, coke yield, and regeneration temperature. The slag discharging mode with a fixed period cannot be matched with the actual slag generating speed, so that the two extreme conditions are that firstly, slag discharging is delayed, slag is accumulated at the bottom of the regenerator, heat exchange efficiency is reduced, even a tower is blocked, and secondly, slag discharging is over-frequency, so that a large amount of effective washing oil is discharged along with the slag, and the material consumption and the load of subsequent separation treatment are increased. In addition, in the conveying link of slag-containing materials, the materials have the characteristics of high viscosity and high solid content, and the industrial site usually adopts high-pressure steam or pumping mode for forced conveying. Existing delivery control systems lack real-time monitoring of fluid conditions in the tubing, often with a single pursuit of high flow rates or high pressure differentials to prevent clogging. The blind high-strength conveying can generate severe shearing and turbulence in a pipeline, and the deep emulsification of the oil, water and slag three-phase mixture is extremely easy to occur. Once a stable emulsion is formed, the gravity settling separation effect in the downstream mechanical clarifier will be significantly reduced, resulting in an excessive water content of the separated supernatant or an excessive oil carrying rate of the discharged waste residue. The current control scheme can not automatically adjust the conveying strategy according to the rheological characteristic change in the conveying process, and is difficult to balance between anti-blocking and anti-emulsifying. Disclosure of Invention Aiming at the defects of the prior art, the invention provides an energy efficiency optimization method and system for deslagging in the coal gas debenzolization process, which solve the problems of slag accumulation or wash oil waste caused by mismatching of deslagging quantity and slag production rate of a wash oil regeneration system and deep emulsification caused by out-of-control shearing in the high-viscosity slag-containing material conveying process so as to reduce separation efficiency. In order to achieve the above purpose, the first aspect of the present invention provides an energy efficiency optimization method for deslagging in a coal gas debenzolization process, so as to solve the technical problems of lag control of deslagging amount of a wash oil regeneration system, lewis blockage of a conveying pipe, and low separation efficiency caused by emulsification. The energy efficiency optimization method for deslagging in the coal gas debenzolization process comprises the following steps: collecting operation parameters of a coal gas debenzolization system, calculating the instantaneous slag generation rate of circulating wash oil by utilizing a reaction dynamics model, and carrying out time integration on the instantaneous slag generation rate to obtain the current accumulated slag quantity; When the accumulated slag quantity reaches a preset slag discharging threshold, determining the target discharge quality of the current slag discharging, establishing a mapping relation between the opening time of a slag discharging valve and the target discharge quality based on a fluid mechanics model, converting the target discharge quality into the target opening time action time of the slag discharging valve by using the mapping relation, and controlling the time calculated by opening the slag discharging valve by the target opening time to quantitatively discharge slag-containing materials to a thin slag tan