CN-121979342-A - Automatic control method and system for methanol aqueous solution

CN121979342ACN 121979342 ACN121979342 ACN 121979342ACN-121979342-A

Abstract

The application discloses an automatic control method and an automatic control system for a methanol aqueous solution, and belongs to the field of automatic control systems. The system comprises a raw material unit, a mixing unit, a storage unit, a liquid supplementing unit, a detection unit and a control unit. The raw material unit is used for storing pure methanol and deionized water, monitoring liquid level change in real time through a liquid level sensor, the mixing unit is used for accurately mixing methanol and water according to a set proportion through the cooperation of the liquid pump and the stirrer, the storage unit is used for storing prepared aqueous methanol solution and conveying the aqueous methanol solution to the reaction device through the liquid pump, the liquid supplementing unit is used for regulating the liquid supplementing amount through the liquid supplementing pump, the electromagnetic valve and the overflow valve, timely supplementing of the aqueous methanol solution according to equipment requirements is ensured, the detection unit is used for monitoring the state of the aqueous methanol solution in real time through concentration, liquid level, temperature and pressure sensors, the control unit is used for receiving signals of the sensors, carrying out data processing and regulating the working state of each unit of the system, and ensuring that the proportion, the liquid level, the flow, the temperature and the pressure of the aqueous methanol solution are always in ideal states. The application eliminates errors caused by manual operation through automatic control and real-time feedback adjustment, and improves the efficiency of the methanol hydrogen production equipment and the quality of hydrogen.

Inventors

ZHANG HONGTU
TONG ZHAOJIE
WU WENFU
ZHOU YING
LIN ZIXUAN

Assignees

苏州氢捷安新能源科技有限公司

Dates

Publication Date: 20260505
Application Date: 20260202

Claims (9)

1. An automatic control system for aqueous methanol solutions, said system comprising: the raw material unit is used for storing pure methanol and deionized water and is provided with a liquid level sensor to monitor liquid level change; The mixing unit comprises a mixing preparation barrel, a stirrer and a liquid pump, wherein the mixing preparation barrel is used for mixing methanol and deionized water according to a set proportion, the stirrer is used for accelerating mixing, and the liquid pump is used for controlling inflow of the methanol and the water; the storage unit comprises a methanol water bucket and a liquid extracting pump and is used for storing the prepared methanol water solution and conveying the prepared methanol water solution to the reaction device; the liquid supplementing unit comprises a liquid supplementing pump, a liquid supplementing pipeline, an electromagnetic valve and an overflow valve, wherein the liquid supplementing pump is used for conveying the prepared methanol aqueous solution to methanol hydrogen production equipment, and the electromagnetic valve is used for accurately regulating the liquid supplementing amount; the filtering unit is arranged at the front ends of each liquid pump and each liquid supplementing pump and is used for removing impurities in fluid entering each link; the detection unit comprises a concentration sensor, a liquid level sensor, a temperature sensor and a pressure sensor, wherein the sensors are used for monitoring the concentration, the liquid level, the temperature and the pressure of the methanol aqueous solution in real time; and the control unit is used for receiving signals from the sensors and controlling the adjustment of liquid level, flow, concentration and temperature, so as to ensure the accurate and stable proportioning of the methanol aqueous solution.
2. The automatic methanol aqueous solution replenishing preparation detection control system according to claim 1, wherein the system realizes real-time monitoring and feedback adjustment of each unit through an embedded controller or a Programmable Logic Controller (PLC); The liquid supplementing unit regulates the liquid supplementing amount of each branch through an electromagnetic valve, so that the methanol aqueous solution can be timely supplemented according to the requirements of methanol hydrogen production equipment; The mixing unit is matched with the stirrer through the liquid pump, ensures that methanol and water are mixed efficiently according to a preset proportion, and monitors the concentration of the mixed solution in real time through the concentration sensor.
3. The automatic liquid replenishing preparation control system of the aqueous methanol solution according to claim 1, wherein the system further comprises an intelligent early warning function, and when the liquid level, the concentration, the temperature or the pressure is detected to be out of a set range, the control unit automatically gives an alarm and stops related operations.
4. The automatic liquid replenishing preparation and detection control system for the aqueous methanol solution according to claim 1, wherein the liquid replenishing pipeline is provided with a pressure sensor and a flow sensor, monitors the pressure and the flow in the liquid replenishing process, and controls the operation of the liquid replenishing pump according to sensor data.
5. An automatic liquid-replenishing preparation detection control method for a methanol aqueous solution, which is characterized by being applicable to the automatic liquid-replenishing preparation detection control system for the methanol aqueous solution according to any one of claims 1 to 4, and comprising the following steps: Step one, presetting a target concentration of a methanol aqueous solution through a control unit Liquid level threshold of mixing preparation barrel Temperature compensation model , wherein, At a reference temperature The density of the methanol aqueous solution is k, which is a temperature-density correction coefficient; Step two, utilizing liquid level sensors of the raw material unit and the storage unit to monitor the liquid level L of the pure methanol barrel, the deionized water barrel and the methanol barrel in real time, if the liquid level L of the methanol barrel is < "> The control unit starts the automatic preparation flow of the mixing unit, if L is not less than According to the real-time load signal of the methanol hydrogen production equipment, regulating the liquid supplementing amount of each branch through the electromagnetic valve of the liquid supplementing unit, and executing accurate liquid supplementing according to the requirement; Step three, in the preparation flow, the control unit checks the liquid levels of the pure methanol barrel and the deionized water barrel, and if the liquid levels are normal, the theoretical volume flow ratio of the methanol to the deionized water is calculated according to Ct The real-time temperature T acquired by a temperature sensor in a detection unit of the mixed preparation barrel is combined and corrected into the actual mass flow ratio through rho (T) Dynamically adjusting the power of the liquid pump of the mixing unit to ensure that the methanol and the deionized water are mixed according to the following ratio Flowing into a mixing preparation barrel, and synchronously starting a stirrer; Detecting the concentration C of the methanol aqueous solution in real time by using concentration sensors of the mixing unit and the storage unit, if Wherein For concentration tolerance, the control unit again corrects the flow ratio based on ρ (T) until C stabilizes at If the temperature sensor in the detection unit detects ( A temperature alarm threshold value), immediately triggering the stirrer to slow down and temporarily supplementing the deionized water for linkage; step five, if the liquid level of the pure methanol barrel or the deionized water barrel is after the preparation process is started Does not rise back to within a period of time The control unit triggers the intelligent early warning function, sends out audible and visual alarm and interlockingly pauses the operation of the methanol hydrogen production equipment until the liquid level is recovered, and synchronously triggers early warning and adjusts the operation of the liquid supplementing pump if the pressure sensor and the flow sensor of the liquid supplementing pipeline detect abnormality.
6. The method for automatically supplementing aqueous methanol solution, preparing and controlling according to claim 5, wherein the method for constructing the temperature compensation model ρ (T) comprises controlling the aqueous methanol solution temperature from a constant temperature water bath device in a laboratory environment Gradient change to The density rho of each temperature point is acquired by a high-precision densimeter of the detection unit, and the density rho is obtained by adopting least square fitting Wherein a, b, c are fitting coefficients, and goodness of fit And solidifying the model in a memory module of the control unit.
7. The method for automatic liquid replenishment formulation control for an aqueous methanol solution as set forth in claim 5, further comprising the step of, when the concentration is deviated When in use, if The control unit is formulated as The power of the methanol liquid pump of the mixing unit is reduced, The value range is 0.1-0.5 for the concentration-power adjusting coefficient, if C is smaller than Ct, the power of the methanol liquid pump is increased according to the same formula, when the temperature is equal to that of the methanol liquid pump When the control unit firstly controls the rotation speed of the stirrer of the mixing unit to be changed from Down to Simultaneously starting a temporary cooling mode of the deionized water branch of the raw material unit until a temperature sensor in the detection unit detects that , wherein, The temporary cooling mode is used for additionally supplementing deionized water with the proportion of 5-10% for the temperature-rotating speed regulating coefficient with the value range of 0.01-0.05.
8. The method according to claim 5, wherein the step five further comprises if the temperature sensor in the detecting unit of the mixing and preparing tank detects that the temperature T is within the range of The internal continuous rising speed delta T/delta T is more than 0.5 ℃ per second, the control unit judges that the abnormal temperature rise is fault, all the liquid pump power supplies of the mixing unit are immediately cut off, the emergency emptying valve of the mixing preparation barrel is started, the control unit pushes a fault code E001 to the remote monitoring end, and after the fault is relieved, the control unit is waited to reset the restarting process of the control unit manually.
9. The control method according to claim 5, wherein the step-content support is linked with the operation mode of the methanol-to-hydrogen plant, and comprises a liquid level threshold when the methanol-to-hydrogen plant is switched to the "start-up mode Is adjusted to the starting liquid level , 10% -15% Higher than the normal threshold, and automatically recovering to preset normal parameters after the equipment enters a 'stable operation mode', and realizing working condition self-adaptive regulation and control through a control unit.

Description

Automatic control method and system for methanol aqueous solution Technical Field The embodiment of the application relates to the field of automatic control systems, in particular to an automatic control method and an automatic control system for a methanol aqueous solution. Background In methanol hydrogen production equipment, the proportion of methanol aqueous solution and timely fluid replacement have important influences on the operation efficiency of the equipment, the hydrogen yield and the hydrogen quality. Traditional methanol aqueous solution preparation and liquid replenishing methods generally rely on manual operation or a simple liquid level control system. The method is complex in operation, and is easy to cause inaccurate proportioning and untimely liquid supplementing due to artificial factors or errors of the liquid level sensor, so that the stability of the methanol hydrogen production process is affected. In the prior art, many preparation and liquid supplementing methods of methanol aqueous solutions depend on fixed mixing proportion and timing liquid level monitoring, but the methods have the defects that due to the lack of real-time monitoring and feedback regulation, the traditional system cannot accurately control the ratio of methanol to water according to the actual requirements of reaction equipment, so that the ratio error is caused, and the yield and quality of hydrogen are affected. The existing liquid level control system can only monitor the upper limit and the lower limit of liquid, and when the liquid level is too low, the liquid replenishing operation can be triggered, the liquid replenishing reaction is often delayed, and the automatic replenishment can not be carried out according to the concentration change of the solution in real time. Due to the uneven mixing of methanol and water, the reaction process may be affected, resulting in unstable hydrogen production. The uniformity of the aqueous solution of methanol cannot be ensured by a simple mixing mode in the prior art, and the efficiency of the methanol hydrogen production equipment is affected. Therefore, a new technical scheme is needed, which can provide more accurate methanol aqueous solution proportioning, automatic liquid supplementing and real-time detection functions, and ensure the quality stability of the methanol aqueous solution, so that the stability of the methanol hydrogen production process and the yield and quality of hydrogen are improved. Disclosure of Invention The embodiment of the application provides an automatic control method and an automatic control system for a methanol aqueous solution. The technical scheme is as follows: According to one aspect of the present application, there is provided an aqueous methanol solution autopilot control system, the system comprising: the raw material unit is used for storing pure methanol and deionized water and is provided with a liquid level sensor to monitor liquid level change; The mixing unit comprises a mixing preparation barrel, a stirrer and a liquid pump, wherein the mixing preparation barrel is used for mixing methanol and deionized water according to a set proportion, the stirrer is used for accelerating mixing, and the liquid pump is used for controlling inflow of the methanol and the water; the storage unit comprises a methanol water bucket and a liquid extracting pump and is used for storing the prepared methanol water solution and conveying the prepared methanol water solution to the reaction device; the liquid supplementing unit comprises a liquid supplementing pump, a liquid supplementing pipeline, an electromagnetic valve and an overflow valve, wherein the liquid supplementing pump is used for conveying the prepared methanol aqueous solution to methanol hydrogen production equipment, and the electromagnetic valve is used for accurately regulating the liquid supplementing amount; the filtering unit is arranged at the front ends of each liquid pump and each liquid supplementing pump and is used for removing impurities in fluid entering each link; the detection unit comprises a concentration sensor, a liquid level sensor, a temperature sensor and a pressure sensor, wherein the sensors are used for monitoring the concentration, the liquid level, the temperature and the pressure of the methanol aqueous solution in real time; and the control unit is used for receiving signals from the sensors and controlling the adjustment of liquid level, flow, concentration and temperature, so as to ensure the accurate and stable proportioning of the methanol aqueous solution. Optionally, the system realizes real-time monitoring and feedback adjustment of each unit through an embedded controller or a Programmable Logic Controller (PLC); The liquid supplementing unit regulates the liquid supplementing amount of each branch through an electromagnetic valve, so that the methanol aqueous solution can be timely supplemented according to the requirements of methano