CN115454180B - Supercritical CO 2 Extraction system pressure and temperature control method - Google Patents
Supercritical CO 2 Extraction system pressure and temperature control method Download PDFInfo
- Publication number
- CN115454180B CN115454180B CN202211205047.2A CN202211205047A CN115454180B CN 115454180 B CN115454180 B CN 115454180B CN 202211205047 A CN202211205047 A CN 202211205047A CN 115454180 B CN115454180 B CN 115454180B
- Authority
- CN
- China
- Prior art keywords
- temperature
- pressure
- supercritical
- value
- extraction
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 238000000605 extraction Methods 0.000 title claims abstract description 84
- 238000000034 method Methods 0.000 title claims abstract description 40
- 230000001105 regulatory effect Effects 0.000 claims abstract description 22
- 230000008569 process Effects 0.000 claims abstract description 21
- 230000008859 change Effects 0.000 claims abstract description 8
- 230000000630 rising effect Effects 0.000 claims abstract description 4
- 230000001276 controlling effect Effects 0.000 claims description 7
- 238000012937 correction Methods 0.000 abstract description 7
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 description 6
- 230000006870 function Effects 0.000 description 5
- 238000010586 diagram Methods 0.000 description 4
- 229910002092 carbon dioxide Inorganic materials 0.000 description 3
- 239000001569 carbon dioxide Substances 0.000 description 3
- 230000001965 increasing effect Effects 0.000 description 3
- 238000012986 modification Methods 0.000 description 3
- 230000004048 modification Effects 0.000 description 3
- 238000000194 supercritical-fluid extraction Methods 0.000 description 3
- 230000000694 effects Effects 0.000 description 2
- 238000006243 chemical reaction Methods 0.000 description 1
- 238000004891 communication Methods 0.000 description 1
- 230000008878 coupling Effects 0.000 description 1
- 238000010168 coupling process Methods 0.000 description 1
- 238000005859 coupling reaction Methods 0.000 description 1
- 238000001514 detection method Methods 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 230000002708 enhancing effect Effects 0.000 description 1
- 238000004880 explosion Methods 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 230000004044 response Effects 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 239000002904 solvent Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 230000001360 synchronised effect Effects 0.000 description 1
- 238000012360 testing method Methods 0.000 description 1
- 238000009834 vaporization Methods 0.000 description 1
- 230000008016 vaporization Effects 0.000 description 1
Classifications
-
- G—PHYSICS
- G05—CONTROLLING; REGULATING
- G05D—SYSTEMS FOR CONTROLLING OR REGULATING NON-ELECTRIC VARIABLES
- G05D27/00—Simultaneous control of variables covered by two or more of main groups G05D1/00 - G05D25/00
- G05D27/02—Simultaneous control of variables covered by two or more of main groups G05D1/00 - G05D25/00 characterised by the use of electric means
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D11/00—Solvent extraction
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P20/00—Technologies relating to chemical industry
- Y02P20/50—Improvements relating to the production of bulk chemicals
- Y02P20/54—Improvements relating to the production of bulk chemicals using solvents, e.g. supercritical solvents or ionic liquids
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Engineering & Computer Science (AREA)
- Automation & Control Theory (AREA)
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Feedback Control In General (AREA)
Abstract
The invention provides a supercritical CO 2 The extraction system pressure and temperature control method integrates the advantages of fuzzy control and PID control, introduces series correction and feedback correction, eliminates the mutual interference of temperature and pressure in the system, solves the overshoot problem of temperature in the boosting process to a certain extent, and reduces the interference of external uncontrolled factors. By judging supercritical CO 2 Whether the change rate difference value of the temperature and the pressure of the extraction kettle in the extraction system meets an expected value or not, and the temperature regulating valve is subjected to fuzzy control in a feedback correction mode, so that the influence of pressure rise on the temperature in the system is eliminated, the overshoot problem of the temperature in the pressure rising process is solved to a certain extent, and the interference of flow fluctuation on the system operation is eliminated, so that the system can stably and efficiently operate.
Description
Technical Field
The invention belongs to the technical field of supercritical extraction, and in particular relates to a method for extractingSupercritical CO 2 A control method of an extraction system.
Background
Supercritical CO 2 The extraction is carried out by utilizing supercritical CO 2 I.e. CO in a thermodynamic state with a temperature above the critical temperature and a pressure above the critical pressure 2 As an extractant, a technique of extracting a specific component from a liquid or a solid. CO in supercritical state 2 Has high solubility and fluidity, and the solubility can change along with the change of temperature and pressure, thus the aim of separating and purifying substances can be realized. In the production and use, the extraction kettle is in a high-pressure low-temperature state, wherein CO 2 The fluctuation of pressure and temperature can cause unstable extraction process, so that the extraction time is long and the extraction effect is poor; excessive pressure overshoot can even cause the explosion of the kettle body to cause personal and property damage; and excessive temperature overshoot can lead to deterioration of the extract in the kettle body.
Currently, most of the control of temperature and pressure in supercritical extraction processes still use simple PID control methods, and PID controllers designed for specific systems can be well controlled in some cases, but they still have some problems. When the control system is in a closed loop operation, a test signal needs to be inserted in the control process, but the method can cause disturbance, and the PID controller can generate overshoot under the influence of the disturbance. In the supercritical extraction process of carbon dioxide, various measurable and non-measurable interferences exist, and certain coupling and mutual interference problems exist between the temperature and the pressure; the effect of the heat absorbed or evolved by the vaporization or liquefaction of carbon dioxide on temperature; some of the carbon dioxide is not in a supercritical state, so that the solvent amount is reduced, the extraction rate is reduced, and the problems are to be solved.
Disclosure of Invention
In order to solve the problems, the invention provides a method for greatly enhancing supercritical CO 2 The anti-interference performance of the operation of the extraction system, and the stability and the high efficiency of the system are improved.
In order to realize the technical content, the invention adopts the following technical scheme.
Supercritical CO 2 The extraction system pressure and temperature control method integrates the advantages of fuzzy control and PID control, introduces series correction and feedback correction, eliminates the mutual interference of temperature and pressure in the system, solves the overshoot problem of temperature in the boosting process to a certain extent, and reduces the interference of external uncontrolled factors. The operation of the system is divided into a boosting process, a heating process, a constant pressure process and a constant temperature process. When the system is in the pressure increasing process, the temperature can be greatly increased along with the pressure increase according to the thermodynamic equation, and the heat exchange operation or the slow heat exchange operation is stopped for the system at the moment so as to prevent the excessive temperature overshoot.
The pressure value and the temperature value of the extraction kettle are read through the pressure transmitter and the temperature transmitter and are transmitted to the PLC system, the PLC system calculates according to the received signals, the calculation result is converted into a current signal and is transmitted to the pressure regulating valve and the temperature regulating valve for control, and therefore the pressure value and the temperature value are regulated to target setting parameters, and the PLC system calculation control process comprises the following steps:
s1: taking a pressure value P read by a pressure transmitter in an extraction system as an input value, and creating a PID controller to control the opening of a pressure regulating valve;
s2: judgment of supercritical CO 2 Reading whether the pressure value P in the extraction system reaches Ps or not, if not, indicating that the system is in a boosting process, and if so, controlling the temperature rising rate to prevent temperature overshoot, and executing step S3;
s3: judgment of supercritical CO 2 If the read temperature value T in the extraction system is smaller than Ts, if so, the system temperature is not over-regulated yet, and the degree of change of the temperature and the pressure needs to be further controlled, and then the step S4 is executed;
s4: judging whether the value of [ (P-P0)/(Ps-P0) - (T-T0)/(Ts-T0) ] is smaller than or equal to an expected value, if not, executing the step S5; if yes, go to step S6. Wherein P0 is initial pressure, ps is desired pressure, T0 is initial temperature, ts is desired temperature, and father is constant with value range of 0, 1;
s5: the opening degree of the heat exchange valve is controlled by taking [ (P-P0)/(Ps-P0) - (T-T0)/(Ts-T0) ] as an input variable of fuzzy control, and the step S3 is executed in a return manner;
s6: supercritical CO 2 The pressure value P of an extraction kettle in the extraction system is adjusted to be a target pressure value Ps;
further, step S6 includes the sub-steps of:
s61: judgment of supercritical CO 2 CO entering extraction kettle in extraction system 2 If the flow Q satisfies the first flow condition, executing step S65, if not, executing step S62;
s62: judgment of supercritical CO 2 CO entering extraction kettle in extraction system 2 If the flow Q meets the second flow condition, executing step S65, if not, executing step S63;
s63: judgment of supercritical CO 2 CO entering extraction kettle in extraction system 2 If the flow Q satisfies the third flow condition, executing step S65, if not, executing step S64;
s64: judgment of supercritical CO 2 CO entering extraction kettle in extraction system 2 Whether the flow Q meets the fourth flow condition, if so, executing the step S65;
the first flow conditions are: supercritical CO 2 CO entering extraction kettle in extraction system 2 Flow rate Q<QMAX, and Q>3/4QMAX；
The second flow conditions were: supercritical CO 2 CO entering extraction kettle in extraction system 2 Flow rate Q<3/4QMAX, and Q>1/2QMAX；
The third flow rate condition is: supercritical CO 2 CO entering extraction kettle in extraction system 2 Flow rate Q<3/4QMAX, and Q>1/2QMAX；
The fourth flow condition is: supercritical CO 2 CO entering extraction kettle in extraction system 2 Flow rate Q<1/2QMAX；
Wherein QMAX is the maximum output flow rate of the booster pump;
s65: creating a fuzzy controller by taking the flow Q as an input variable to carry out PID parameter adjustment on a PID controller of the pressure regulating valve;
further, the methodIn step S2, if supercritical CO 2 The pressure value P in the extraction system reaches a set value Ps, which indicates that the system has reached a constant pressure process, and the temperature needs to be regulated to the set value as soon as possible and kept balanced, and then the step S7 is executed;
s7: performing opening control on the heat exchange valve by taking Ts-T as an input variable of fuzzy control, and executing a step S6;
further, in step S3, if supercritical CO 2 The temperature value T in the extraction system is not smaller than the set value Ts, the system temperature is adjusted excessively, the heat exchange function of the heat exchanger needs to be blocked, the opening of the heat exchange valve is controlled to be 0, and the step S8 is executed;
s8: controlling the opening degree of the heat exchange valve to be 0, and executing a step S6;
compared with the prior art, the invention has the advantages that by judging the supercritical CO 2 If the difference value of the change rate of the temperature and the pressure of the extraction kettle in the extraction system meets the expected value, the temperature regulating valve can be subjected to fuzzy control in a feedback correction mode, so that the influence of pressure rise on the temperature in the system is eliminated, and the overshoot problem of the temperature in the boosting process is solved to a certain extent. Determining supercritical CO by the first flow condition, the second flow condition, the third flow condition, and the fourth flow condition 2 The pressure change trend of the extraction kettle in the extraction system can be corrected by feedforward correction and fuzzy control, PID control parameters are corrected by fuzzy control, and interference of flow fluctuation on system operation is eliminated, so that the system can operate stably and efficiently.
Drawings
FIG. 1 is a flow chart of the steps of the present control method;
FIG. 2 is supercritical CO 2 A simple structure schematic diagram of an extraction system;
FIG. 3 is a schematic diagram of a control system in an embodiment of the invention.
Detailed Description
The present invention will be described in further detail with reference to specific examples.
It should be understood that the structures, proportions, sizes, etc. shown in the drawings are for illustration purposes only and are not intended to limit the scope of the invention, which is defined by the claims, unless otherwise indicated, and that any structural modifications, proportional changes, or adjustments of size, which would otherwise be used in the practice of the invention, would be apparent to those skilled in the art without departing from the spirit and scope of the invention. Also, the terms such as "upper", "lower", "left", "right", "middle", etc. are used herein for convenience of description, but are not to be construed as limiting the scope of the invention, and the relative changes or modifications are not to be construed as essential to the scope of the invention.
Example 1
The simple structure of the control system is shown in figure 2, the S7-1500 series PLC of Siemens corporation in Germany is selected as the main control element, and the structure block diagram is shown in figure 3. The PLC system comprises a power supply module, a CPU module, an analog input module and an analog output module, wherein the analog input module is an AI module, and the analog output module is an AO module. The flowmeter is communicated with the CPU module through the CAN bus, the pressure transmitter and the temperature transmitter transmit the pressure value and the temperature value to the AI module through a 4-20mA current loop communication mode, and the AI module digitally processes the input current signal and transmits the input current signal to the CPU. The CPU module is used as a controller to compare the detection value with the set value, and the control method is used for sending out a control instruction. The control command sent by the CPU is converted into a current signal through the AO module and transmitted to the pressure regulating valve and the temperature regulating valve, so that the pressure value and the temperature value are regulated to target setting parameters. The PLC is connected with an industrial personal computer provided with TIA Portal configuration software through a Profinet industrial Ethernet, and the program written in the ladder diagram language by the control method is downloaded to the CPU module of the S7-1500 PLC.
Supercritical CO 2 The method for controlling the pressure and the temperature of the extraction system comprises the following steps after the system is started, as shown in fig. 1.
Step S1: taking a pressure value P read by a pressure transmitter in an extraction system as an input value, creating an opening degree of a pressure regulating valve controlled by a PID controller, executing a step S2, presetting PID parameters of the PID controller by using a self-contained PID module debugging function of TIA Portal configuration software, and further setting and regulating the PID parameters by creating a fuzzy controller;
step S2: judgment of supercritical CO 2 Reading whether the pressure value P in the extraction system reaches a set value Ps or not, if not, indicating that the system is in a boosting process, wherein the temperature can be greatly increased along with the pressure increase in the process, and controlling the rising rate of the temperature to be equal to or lower than the change rate of the pressure as much as possible to prevent the temperature from overshooting, so that the step S3 can be executed; otherwise, the system is indicated to reach the constant pressure process, the temperature needs to be adjusted to the set value as soon as possible and the balance is maintained, and the step S7 can be executed;
step S3: judgment of supercritical CO 2 Whether the temperature value T read in the extraction system is smaller than a preset value Ts or not, if yes, executing step S4; otherwise, the system temperature is indicated to be overshot, the heat exchange function of the heat exchanger needs to be blocked, and the step S8 can be executed;
step S4: judging whether the value of [ (P-P0)/(Ps-P0) - (T-T0)/(Ts-T0) ] is smaller than or equal to an expected value, if not, executing the step S5; wherein, the father is a constant with the value range of [0,1], the smaller the value is, the more synchronous the temperature and pressure changes are, but the larger the fluctuation of the system is, the harder the stable operation is, and the value is generally 0.1; if yes, executing step S6;
step S5: the opening degree of the heat exchange valve is controlled by taking [ (P-P0)/(Ps-P0) - (T-T0)/(Ts-T0) ] [ e ] as an input variable of fuzzy control, and the step S3 is executed in a return manner;
wherein the fuzzy controller creates rules as follows:
rule 1: e <0, closing the valve;
rule 2: e >0, e is divided into 5 fuzzy sets: VS, S, M, L, VL, with a range of values of [0,1], blurring the triangle by adopting a triangle membership function;
rule 3: the valve opening K is divided into 5 fuzzy sets: NB, NS, O, PS, PB, value ranges [0,100], which are obscured by triangle membership functions;
rule 4: the larger the difference e, the larger the opening K;
s6: supercritical CO 2 The pressure value P of the extraction kettle in the extraction system is adjusted to be a target pressure value Ps, and in order to meet the stable control requirement of pressure under different flow rates, the PID parameters are corrected on line by utilizing a fuzzy control rule. Which comprises the following substeps:
s61: judgment of supercritical CO 2 CO entering extraction kettle in extraction system 2 If the flow Q satisfies the first flow condition, step S65 is executed, and if not, step S62 is executed;
s62: judgment of supercritical CO 2 CO entering extraction kettle in extraction system 2 If the flow Q meets the second flow condition, executing step S65, if not, executing step S63;
s63: judgment of supercritical CO 2 CO entering extraction kettle in extraction system 2 If the flow Q satisfies the third flow condition, executing step S65, if not, executing step S64;
s64: judgment of supercritical CO 2 CO entering extraction kettle in extraction system 2 Whether the flow Q meets the fourth flow condition, if so, executing the step S65;
the first flow conditions are: supercritical CO 2 CO entering extraction kettle in extraction system 2 Flow rate Q<QMAX, and Q>3/4 QMAX；
The second flow conditions were: supercritical CO 2 CO entering extraction kettle in extraction system 2 Flow rate Q<3/4QMAX, and Q>1/2 QMAX；
The third flow rate condition is: supercritical CO 2 CO entering extraction kettle in extraction system 2 Flow rate Q<3/4QMAX, and Q>1/2 QMAX；
The fourth flow condition is: supercritical CO 2 CO entering extraction kettle in extraction system 2 Flow rate Q<1/2QMAX；
Wherein QMAX is the maximum output flow rate of the booster pump;
s65: creating a fuzzy controller by taking the flow as an input variable to carry out PID parameter adjustment on a PID controller of the pressure regulating valve; it satisfies the following rules:
rule 1: when the flow is large, the valve response is quickened by taking larger Kp and smaller Kd, the reaction can be quickly performed, and the Ki=0 is enabled to avoid excessive pressure overshoot;
rule 2: when the flow is moderate, the Kp is smaller, and the proper Ki and Kd enable the valve to have smaller overshoot;
rule 3: when the flow is smaller, larger Kp and Ki, kd values should be taken to reduce steady state error.
S7: if supercritical CO 2 The pressure value P in the extraction system reaches a set value Ps, the opening of the heat exchange valve is controlled by taking Ts-T as an input variable of fuzzy control, and the step S6 is executed;
s8: if supercritical CO 2 The temperature value T in the extraction system is not smaller than the set value Ts, the opening degree of the heat exchange valve is controlled to be 0, and the step S6 is executed;
the foregoing description of the preferred embodiments of the invention is not intended to be limiting, but rather is intended to cover all modifications, equivalents, alternatives, and improvements that fall within the spirit and scope of the invention.
Claims (4)
1. Supercritical CO 2 The pressure and temperature control method of the extraction system comprises the steps of reading the pressure value and the temperature value of an extraction kettle through a pressure transmitter and a temperature transmitter, transmitting the pressure value and the temperature value to a PLC system, calculating by the PLC system according to received signals, converting calculation results into current signals, and transmitting the current signals to a pressure regulating valve and a temperature regulating valve for controlling, so that the pressure value and the temperature value are regulated to target setting parameters, and the method is characterized in that the calculation process of the PLC system comprises the following steps:
s1: taking a pressure value P read by a pressure transmitter in an extraction system as an input value, and creating a PID controller to control the opening of a pressure regulating valve;
s2: judgment of supercritical CO 2 Reading whether the pressure value P in the extraction system reaches Ps or not, if not, indicating that the system is in a boosting process, and if so, controlling the temperature rising rate to prevent temperature overshoot, and executing step S3;
s3: judgment of supercritical CO 2 If the read temperature value T in the extraction system is smaller than Ts, if so, the system temperature is not over-regulated yet, and the degree of change of the temperature and the pressure needs to be further controlled, and then the step S4 is executed;
s4: judging whether the value of [ (P-P0)/(Ps-P0) - (T-T0)/(Ts-T0) ] is smaller than or equal to an expected value, if not, executing the step S5; if yes, executing step S6;
s5: the opening degree of the heat exchange valve is controlled by taking [ (P-P0)/(Ps-P0) - (T-T0)/(Ts-T0) ] as an input variable of fuzzy control, and the step S3 is executed in a return manner;
s6: supercritical CO 2 The pressure value P of an extraction kettle in the extraction system is adjusted to be a target pressure value Ps;
wherein P0 is the initial pressure, ps is the desired pressure, T0 is the initial temperature, ts is the desired temperature, and fatly is a constant with the value range of [0,1 ].
2. The control method according to claim 1, characterized in that step S6 includes the steps of:
s61: judgment of supercritical CO 2 CO entering extraction kettle in extraction system 2 Whether the flow rate Q satisfies Q<QMAX, and Q>3/4QMAX, if yes, execute step S65, if no, execute step S62;
s62: judgment of supercritical CO 2 CO entering extraction kettle in extraction system 2 Whether the flow rate Q satisfies Q<3/4QMAX, and Q>1/2QMAX, if yes, executing step S65, if no, executing step S63;
s63: judgment of supercritical CO 2 CO entering extraction kettle in extraction system 2 Whether the flow rate Q satisfies Q<3/4QMAX, and Q>1/2QMAX, if yes, execute step S65, if no, execute step S64;
s64: judgment of supercritical CO 2 CO entering extraction kettle in extraction system 2 Whether the flow rate Q satisfies Q<1/2QMAX, if yes, execute step S65;
s65: creating a fuzzy controller by taking the flow Q as an input variable to carry out PID parameter adjustment on a PID controller of the pressure regulating valve;
wherein QMAX is the maximum output flow rate of the booster pump.
3. The control method according to claim 2, characterized by further comprising step S7:
s7: if supercritical CO is used in step S2 2 And when the pressure value P in the extraction system reaches a set value Ps, indicating that the system has reached a constant pressure process, regulating the temperature to the set value as soon as possible and keeping balance, controlling the opening of the heat exchange valve by taking Ts-T as an input variable of fuzzy control, and executing a step S6.
4. A control method according to claim 3, further comprising step S8:
s8: if supercritical CO is used in step S3 2 And (3) the temperature value T in the extraction system is not smaller than Ts, the system temperature is adjusted excessively, the heat exchange function of the heat exchanger needs to be blocked, the opening of the heat exchange valve is controlled to be 0, and the step S6 is executed.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211205047.2A CN115454180B (en) | 2022-09-30 | 2022-09-30 | Supercritical CO 2 Extraction system pressure and temperature control method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211205047.2A CN115454180B (en) | 2022-09-30 | 2022-09-30 | Supercritical CO 2 Extraction system pressure and temperature control method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN115454180A CN115454180A (en) | 2022-12-09 |
| CN115454180B true CN115454180B (en) | 2024-02-13 |
Family
ID=84308552
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202211205047.2A Active CN115454180B (en) | 2022-09-30 | 2022-09-30 | Supercritical CO 2 Extraction system pressure and temperature control method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN115454180B (en) |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR20130126125A (en) * | 2012-05-10 | 2013-11-20 | 수원대학교산학협력단 | Method for controlling constant pressure using fuzzy pid controller |
| CN104932579A (en) * | 2015-07-09 | 2015-09-23 | 长春工业大学 | CO2 supercritical extraction temperature fraction order PID control method |
| CN105974953A (en) * | 2016-07-06 | 2016-09-28 | 曲阜师范大学 | Reaction vessel negative pressure rectification fuzzy control method |
| CN110975961A (en) * | 2020-03-04 | 2020-04-10 | 赛默飞世尔（上海）仪器有限公司 | Preheating system for fluid and control method for preheating fluid |
| CN112412559A (en) * | 2020-11-19 | 2021-02-26 | 上海齐耀动力技术有限公司 | Supercritical carbon dioxide closed cycle temperature and pressure coupling control system |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20190366230A1 (en) * | 2018-05-30 | 2019-12-05 | Tomas Casals | High intensity targeting (hit) supercritical fluid extraction system and related methods |
-
2022
- 2022-09-30 CN CN202211205047.2A patent/CN115454180B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR20130126125A (en) * | 2012-05-10 | 2013-11-20 | 수원대학교산학협력단 | Method for controlling constant pressure using fuzzy pid controller |
| CN104932579A (en) * | 2015-07-09 | 2015-09-23 | 长春工业大学 | CO2 supercritical extraction temperature fraction order PID control method |
| CN105974953A (en) * | 2016-07-06 | 2016-09-28 | 曲阜师范大学 | Reaction vessel negative pressure rectification fuzzy control method |
| CN110975961A (en) * | 2020-03-04 | 2020-04-10 | 赛默飞世尔（上海）仪器有限公司 | Preheating system for fluid and control method for preheating fluid |
| CN112412559A (en) * | 2020-11-19 | 2021-02-26 | 上海齐耀动力技术有限公司 | Supercritical carbon dioxide closed cycle temperature and pressure coupling control system |
Non-Patent Citations (6)
| Title |
|---|
| CO2超临界萃取工艺优化及其测控技术研究;李丙林;《工程科技Ⅰ辑》;20200229;B015-1 * |
| Pressing and supercritical CO2 extraction of Camelina sativa oil;Tihomir Moslavac;Industrial Crops and Products》;20140202;122–129 * |
| Raul N. Carvalho Jr..Supercritical fluid extraction from rosemary (Rosmarinus officinalis): Kinetic data, extract's global yield, composition, and antioxidant activity.《The Journal of Supercritical Fluids》.2005,197-204. * |
| 五味子超临界萃取系统控制技术的研究;解雯惠;《工程科技Ⅰ辑》;20180131;B015-15 * |
| 超临界萃取工艺参数优化及其控制方法研究;果芯如;《工程科技Ⅰ辑》;20151231;B015-15 * |
| 高压超临界萃取装置的模糊PID控制方法;董金善;袁士豪;顾伯勤;周剑锋;;控制工程;20110320(第02期);全文 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN115454180A (en) | 2022-12-09 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Ferramosca et al. | MPC for tracking with optimal closed-loop performance | |
| Qin et al. | An overview of nonlinear model predictive control applications | |
| CN103576711B (en) | Based on the chemical reactor temperature-controlled process that quantitative one-parameter PID controls | |
| JP2002523821A (en) | Controller for determining optimal tuning parameters used in a process control system and method of operating the controller | |
| CN102736640B (en) | System and method for controlling water level of deaerator | |
| CN112648029B (en) | Coordinated control optimization method for deep peak regulation working condition of thermal power plant | |
| CN114059084A (en) | Electrolytic hydrogen production system and temperature control method and device thereof | |
| CN115454180B (en) | Supercritical CO 2 Extraction system pressure and temperature control method | |
| US20120310375A1 (en) | A nonlinear intelligent pulse-controller | |
| CN113791587B (en) | Coordination control method, system, storage medium and device of fluidized bed generator set | |
| CN108646808B (en) | Temperature control system and temperature control method of dyeing machine | |
| CN107608415A (en) | A kind of electrical heating pure steam generator based on fuzzy-adaptation PID control | |
| CN111045321A (en) | Method for coordinately controlling embedded internal model controller under deep peak regulation | |
| CN111650829B (en) | Embedded PID module parameter adjusting method, system and device based on artificial intelligence | |
| CN212901461U (en) | Steam drum water level three-impulse control system | |
| CN111338210A (en) | Garbage generator set steam temperature control method based on independent modulation cascade strategy | |
| CN103021489A (en) | Controlling device and method of letdown flow temperature of chemical and volume control system in nuclear power station | |
| CN114326384A (en) | Control method of SCR flue gas denitration system of thermal power plant | |
| CN103064284B (en) | Apply model predictive controller and method that reverse difference suppresses not measurable disturbance | |
| Huzmezan et al. | Adaptive control of delayed integrating systems: a PVC batch reactor | |
| CN112947048B (en) | Control method, system and medium of multivariable coupling control system | |
| JP5172589B2 (en) | Plant multivariable cooperative non-interference control method | |
| CN109066645B (en) | Load control method and device for direct current power supply network of facility agriculture | |
| Vilanova | Revisiting IMC based design of PI/PID controllers for FOPTD models | |
| Guo et al. | An improved generalized predictive control algorithm and its application in unit plant coordinated control system |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |