CN113803707B - Double enthalpy difference correction water supply control method of supercritical unit adapting to frequency modulation requirement - Google Patents
Double enthalpy difference correction water supply control method of supercritical unit adapting to frequency modulation requirement Download PDFInfo
- Publication number
- CN113803707B CN113803707B CN202111160645.8A CN202111160645A CN113803707B CN 113803707 B CN113803707 B CN 113803707B CN 202111160645 A CN202111160645 A CN 202111160645A CN 113803707 B CN113803707 B CN 113803707B
- Authority
- CN
- China
- Prior art keywords
- water supply
- difference correction
- frequency modulation
- enthalpy difference
- control method
- 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
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 title claims abstract description 84
- 238000000034 method Methods 0.000 title claims abstract description 19
- 238000006243 chemical reaction Methods 0.000 claims description 7
- 238000001816 cooling Methods 0.000 claims description 7
- 238000011217 control strategy Methods 0.000 abstract description 3
- 230000008859 change Effects 0.000 description 9
- 239000003245 coal Substances 0.000 description 6
- 230000000694 effects Effects 0.000 description 4
- 230000008901 benefit Effects 0.000 description 3
- 230000004044 response Effects 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 230000005611 electricity Effects 0.000 description 1
- 238000010248 power generation Methods 0.000 description 1
- 230000001105 regulatory effect Effects 0.000 description 1
- 229920006395 saturated elastomer Polymers 0.000 description 1
- 230000004083 survival effect Effects 0.000 description 1
- 238000010977 unit operation Methods 0.000 description 1
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F22—STEAM GENERATION
- F22B—METHODS OF STEAM GENERATION; STEAM BOILERS
- F22B35/00—Control systems for steam boilers
- F22B35/18—Applications of computers to steam boiler control
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F22—STEAM GENERATION
- F22B—METHODS OF STEAM GENERATION; STEAM BOILERS
- F22B37/00—Component parts or details of steam boilers
- F22B37/02—Component parts or details of steam boilers applicable to more than one kind or type of steam boiler
- F22B37/38—Determining or indicating operating conditions in steam boilers, e.g. monitoring direction or rate of water flow through water tubes
Landscapes
- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Thermal Sciences (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Control Of Steam Boilers And Waste-Gas Boilers (AREA)
Abstract
The invention belongs to the technical field of water supply control methods, and particularly relates to a double enthalpy difference correction water supply control method of a supercritical unit, which is suitable for frequency modulation requirements, wherein the primary steam flow is multiplied by an enthalpy difference correction coefficient of a superheater, and then multiplied by a water-cooled wall water supply enthalpy difference correction coefficient to obtain a primary water supply flow set value; the preliminary water supply flow set value is output by taking the water supply flow low protection value, and the water supply flow set value is obtained by adding the output water supply flow set value and the superheat degree correction deviation. The control strategy realizes effective control of temperature under the frequency modulation requirement through double enthalpy value control.
Description
Technical Field
The invention belongs to the technical field of water supply control methods, and particularly relates to a double enthalpy difference correction water supply control method of a supercritical unit, which is suitable for frequency modulation requirements.
Background
In recent years, the thermal power unit has increasingly harsh frequency modulation requirements, short frequency modulation interval and large amplitude, becomes a new current situation of frequency modulation under the ACE mode of the thermal power unit, the traditional thermal power unit control is mainly steady state, and as the new energy duty ratio increases year by year, new requirements are put forward on the frequency modulation capacity of the thermal power unit, the thermal power unit faces the contrast of low electric quantity, low electricity price, double low situation and high coal price, the conventional power generation operation is blocked, the frequency modulation income is a new profit point of the thermal power unit, the frequency modulation capacity of the thermal power unit is improved to be a necessary choice of the market, and the thermal power unit survival is also a necessary way.
The frequency modulation new energy of the thermal power unit is improved, and from the side of the steam turbine, only the influence factors which accord with the deviation on the main control of the steam turbine are increased, so that the steam turbine can quickly act after receiving the load deviation caused by frequency modulation, the steam quantity entering the steam turbine is increased or introduced, and the load is quickly adjusted. And if the main control and the water supply control of the boiler cannot respond in time, the main steam pressure and the main steam temperature can be greatly fluctuated and oscillated, so that the safe operation of the unit is seriously influenced.
The traditional water supply control is coal water ratio control, namely, the pressure change can be generated due to the adjustment of steam flow after the steam turbine main control responds to the load change, at the moment, the boiler main control mainly tracks and compensates the main steam pressure change caused by PID deviation adjustment while the coal supply quantity is along with the load change, the adjustment of the boiler main control is realized, and the water supply is correspondingly changed and adjusted along with the change of the main control coal quantity of the boiler so as to maintain the required water supply quantity. The traditional control is that the steam turbine keeps track of load change, the boiler maintains pressure balance, and the water supply keeps track of boiler coal amount change, and the advantage of this control is: the steady-state response characteristic is good, and the main steam temperature keeping effect is good. And because the boiler coal feeding amount is adjusted for a long time, the response time of the adjusting mode is long under the frequency modulation working condition, the pressure fluctuation is large, and the frequency modulation performance is poor.
Disclosure of Invention
Aiming at the technical problems, the invention provides a double enthalpy difference correction water supply control method of a supercritical unit, which is suitable for frequency modulation requirements.
In order to solve the technical problems, the invention adopts the following technical scheme:
the double enthalpy difference correction water supply control method of the supercritical unit adapting to the frequency modulation requirement comprises the steps of multiplying the main steam flow by the enthalpy difference correction coefficient of the superheater, and multiplying the enthalpy difference correction coefficient of the water cooling wall water supply to obtain a preliminary water supply flow set value; the preliminary water supply flow set value is output by taking the water supply flow low protection value, and the water supply flow set value is obtained by adding the output water supply flow set value and the superheat degree correction deviation.
The superheat degree correction deviation is obtained by converting deviation between the actual superheat degree and the target superheat degree through a deviation conversion function.
The design enthalpy value of the water inlet is calculated in real time by selecting the actual pressure of the water cooling wall inlet and the target temperature of the unit water supply.
The actual enthalpy value of the outlet of the superheater is calculated in real time by selecting the average actual pressure of main steam and the actual steam temperature of the superheater.
The target enthalpy value of the outlet of the superheater is calculated in real time by selecting the average actual pressure of the main steam and the target temperature of the superheater.
The actual enthalpy value of the water supply outlet is calculated in real time by selecting the actual pressure and the actual temperature of the water cooling wall outlet.
The target enthalpy value of the water supply outlet is calculated in real time by selecting the target temperature of the water supply outlet and the actual pressure of the water supply outlet.
Compared with the prior art, the invention has the beneficial effects that:
a double enthalpy difference correction water supply control strategy of a supercritical CFB unit adapting to frequency modulation requirements is provided. In order to respond to the frequency modulation requirement, the main steam pressure of the main steam is inevitably caused to fluctuate rapidly after the main control of the steam turbine responds to the high-frequency and deep-amplitude change of the load, and the main steam flow is regulated and selected by utilizing the dynamic balance relation between the water supply flow and the main steam flow.
The water supply quantity adjusting and tracking main steam flow tracking speed can be obviously improved, the problems of overpressure and undervoltage caused by load change can be quickly supplemented, the main steam temperature control effect is poor, and the pressure and temperature are reversely adjusted. The control strategy realizes effective control of the temperature under the frequency modulation requirement through the control of the double enthalpy value; the difficulty of temperature control is overcome, on one hand, the temperature control is directly output to the final stage influence, and on the other hand, different conversion functions can be selected according to the characteristics of each electric power unit to adjust the influence quantity.
Drawings
FIG. 1 is a block diagram of a control method of the present invention;
FIG. 2 is a graph showing the output of the effect of the feed water amount corresponding to the superheat temperature deviation of the present invention;
Detailed Description
The following description of the embodiments of the present invention will be made clearly and completely, and it is apparent that the described embodiments are only some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.
As shown in FIG. 1, in the supercritical unit double enthalpy difference correction water supply control method adapting to the frequency modulation requirement, the main steam flow is multiplied by the superheater enthalpy difference correction coefficient, and then multiplied by the water-cooled wall water supply enthalpy difference correction coefficient to obtain a preliminary water supply flow set value; the preliminary water supply flow set value is output by taking the water supply flow low protection value, and the water supply flow set value is obtained by adding the output water supply flow set value and the superheat degree correction deviation.
Further, the superheat degree correction deviation is obtained by converting the deviation between the actual superheat degree and the target superheat degree through a deviation conversion function.
The control logic adds the superheat correction deviation to finally output the water supply flow set value. The double enthalpy difference control method has the advantages that the influence of the temperature on the whole body is mainly controlled by utilizing the calculated enthalpy value of the actual pressure, and the influence of the system pressure is considered while the temperature control is ensured.
Because the control method of the steam-water ratio has good pressure fluctuation tracking effect, the temperature control is difficult, on the basis of double enthalpy difference control, the superheat degree deviation correction is added, and the temperature deviation is only subjected to function conversion and is superimposed on the primary water supply flow fixed value, therefore, the control method has the advantages that on one hand, the temperature control is directly output to the final stage for influence, and on the other hand, different conversion functions can be selected according to the characteristics of each electric machine set for adjusting the influence quantity, namely, the size of the superheat degree deviation on the water supply flow correction is adjusted.
Specific: as shown in table 1 and fig. 2 below, the conversion function is a water supply amount influence output corresponding to the superheat temperature deviation, and is a piecewise function based on y=kx+b.
TABLE 1
Specific: the logic control is a control thought, and the detailed water supply control can be based on the control thought by superposing influencing factors.
Further, the water supply flow set value uses dynamic balance of the main steam flow and the water supply flow as basic quantity adjustment; the design enthalpy value of the water inlet is calculated in real time by selecting the actual pressure of the water cooling wall inlet and the target temperature of the unit water supply; the actual enthalpy value of the outlet of the superheater is calculated in real time by selecting the average actual pressure of main steam and the actual steam temperature of the superheater; the target enthalpy value of the outlet of the superheater is calculated in real time by selecting the average actual pressure of main steam and the target temperature of the superheater; the actual enthalpy value of the water supply outlet is calculated in real time by selecting the actual pressure and the actual temperature of the water cooling wall outlet; the target enthalpy value of the water supply outlet is calculated in real time by selecting the target temperature of the water supply outlet and the actual pressure of the water supply outlet.
The target temperature of the superheater can be determined according to the unit operation characteristic, the target temperature is conventionally a constant value, and if the boiler is often over-heated, the constant value can be set to be lower. The target temperature of the water supply outlet is corrected and calculated according to the saturated temperature corresponding to the actual pressure of the water-cooled wall outlet and the characteristics of the unit, so that the outlet enthalpy of the water supply design is reflected more accurately in real time, and the deviation of each unit design and the actual operation working condition can be counteracted by increasing the characteristics of the unit.
The preferred embodiments of the present invention have been described in detail, but the present invention is not limited to the above embodiments, and various changes can be made within the knowledge of those skilled in the art without departing from the spirit of the present invention, and the various changes are included in the scope of the present invention.
Claims (6)
1. The double enthalpy difference correction water supply control method of the supercritical unit adapting to the frequency modulation requirement is characterized by comprising the following steps of:
multiplying the main steam flow by the superheater enthalpy difference correction coefficient, and multiplying the main steam flow by the water-cooled wall feed water enthalpy difference correction coefficient to obtain a preliminary feed water flow set value;
the preliminary water supply flow set value is output by taking the water supply flow low protection value, and the water supply flow set value is obtained by adding the output water supply flow set value and the superheat degree correction deviation;
；
；
the superheat degree correction deviation is obtained by converting deviation between the actual superheat degree and the target superheat degree through a deviation conversion function.
2. The supercritical unit double enthalpy difference correction water supply control method adapting to frequency modulation requirements according to claim 1, characterized in that: the design enthalpy value of the water inlet is calculated in real time by selecting the actual pressure of the water cooling wall inlet and the target temperature of the unit water supply.
3. The supercritical unit double enthalpy difference correction water supply control method adapting to frequency modulation requirements according to claim 1, characterized in that: the actual enthalpy value of the outlet of the superheater is calculated in real time by selecting the average actual pressure of main steam and the actual steam temperature of the superheater.
4. The supercritical unit double enthalpy difference correction water supply control method adapting to frequency modulation requirements according to claim 1, characterized in that: the target enthalpy value of the outlet of the superheater is calculated in real time by selecting the average actual pressure of the main steam and the target temperature of the superheater.
5. The supercritical unit double enthalpy difference correction water supply control method adapting to frequency modulation requirements according to claim 1, characterized in that: the actual enthalpy value of the water supply outlet is calculated in real time by selecting the actual pressure and the actual temperature of the water cooling wall outlet.
6. The supercritical unit double enthalpy difference correction water supply control method adapting to frequency modulation requirements according to claim 1, characterized in that: the target enthalpy value of the water supply outlet is calculated in real time by selecting the target temperature of the water supply outlet and the actual pressure of the water supply outlet.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111160645.8A CN113803707B (en) | 2021-09-30 | 2021-09-30 | Double enthalpy difference correction water supply control method of supercritical unit adapting to frequency modulation requirement |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111160645.8A CN113803707B (en) | 2021-09-30 | 2021-09-30 | Double enthalpy difference correction water supply control method of supercritical unit adapting to frequency modulation requirement |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN113803707A CN113803707A (en) | 2021-12-17 |
| CN113803707B true CN113803707B (en) | 2024-02-27 |
Family
ID=78897227
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202111160645.8A Active CN113803707B (en) | 2021-09-30 | 2021-09-30 | Double enthalpy difference correction water supply control method of supercritical unit adapting to frequency modulation requirement |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN113803707B (en) |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108443859A (en) * | 2018-04-04 | 2018-08-24 | 山西格盟安全生产咨询有限公司 | A kind of feedwater flow control method adapting to load rapid fluctuations |
-
2021
- 2021-09-30 CN CN202111160645.8A patent/CN113803707B/en active Active
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108443859A (en) * | 2018-04-04 | 2018-08-24 | 山西格盟安全生产咨询有限公司 | A kind of feedwater flow control method adapting to load rapid fluctuations |
Non-Patent Citations (4)
| Title |
|---|
| 350MW超临界CFB机组RB控制技术分析;段宝;范龙;李继宏;;发电设备(第01期);全文 * |
| 600MW超超临界机组过热汽温控制策略与优化;沈俭;;中国高新技术企业(第16期);全文 * |
| ACE模式下超临界CFB机组协调控制策略的优化与应用;姜平;李丽锋;赵保国;王晋权;张海伟;任岐;;工业仪表与自动化装置(第02期);全文 * |
| 横流式混合换热器中传质系数与压降的数学模型;葛克山;王群;;农机化研究(第03期);全文 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN113803707A (en) | 2021-12-17 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN108443859B (en) | Water supply flow control method adaptive to rapid load fluctuation | |
| US11236633B2 (en) | Solar aided coal-fired power generation system participating in primary frequency regulation and control method thereof | |
| CN101864994B (en) | Correction method for optimization of sliding pressure of large steam turbine | |
| CN102611124B (en) | Primary frequency regulation control method applicable to thermal generator set of intelligent power grid | |
| CN112650169B (en) | Generator set main parameter control system based on enthalpy value and fuel online heat value calculation | |
| CN112039091B (en) | Primary frequency modulation control method based on zero number high-order addition | |
| CN113452092B (en) | Control method for improving AGC comprehensive frequency modulation performance index of thermal power generating unit | |
| CN103513573A (en) | Optimal control method for 300MW unit to effectively stabilize temperature of main steam | |
| CN111649313A (en) | Control method for inhibiting heat transfer deterioration of water-cooled wall of vertical tube coil of supercritical boiler | |
| JP5840032B2 (en) | Power generation system and steam temperature control method thereof | |
| CN113359442B (en) | Coal water ratio control method and system | |
| CN113803707B (en) | Double enthalpy difference correction water supply control method of supercritical unit adapting to frequency modulation requirement | |
| CN115751279A (en) | Main steam temperature optimization control method and device for peak-shaving frequency-modulation thermal generator set | |
| CN112327624B (en) | Peak-shaving operation method for coal-fired unit | |
| CN113050411A (en) | Steam turbine main control auxiliary pressure regulating control system and method during deep peak regulation | |
| CN113283098B (en) | Calculation method for steam temperature feedforward control signal of superheater/reheater of thermal power generating unit | |
| CN113644666B (en) | Electric energy storage coupling frequency modulation control system and method for thermal power generating unit | |
| CN110703703B (en) | High-feed water bypass control method for thermal power generating unit | |
| CN113341699B (en) | Variable integral pressure tracking control method | |
| CN113217118B (en) | High-power compensation method for opening degree of steam turbine regulating valve | |
| CN111472852B (en) | Intermediate point enthalpy value frequency modulation based logical optimization method for generator set | |
| CN113431652B (en) | Wet cooling unit combining cyclic peak regulation and frequency modulation and operation method thereof | |
| KR102086250B1 (en) | Boiler Enthalpy Automatic Control Circuit On Classified By Coal Property | |
| JP2612740B2 (en) | Automatic power plant control system | |
| JP3221738B2 (en) | Steam temperature controller for variable-pressure once-through boiler |
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 | ||
| TA01 | Transfer of patent application right | ||
| TA01 | Transfer of patent application right |
Effective date of registration: 20240112 Address after: 045000 No. 9, Quansheng street, Baiquan Industrial Zone, Yangquan City, Shanxi Province Applicant after: SHANXI HEPO GENERATING Co.,Ltd. Applicant after: Shanxi Gemeng Sino US clean energy R & D Center Co.,Ltd. Address before: 045000 No. 9, Quansheng street, Baiquan Industrial Zone, Yangquan City, Shanxi Province Applicant before: SHANXI HEPO GENERATING Co.,Ltd. |
|
| GR01 | Patent grant | ||
| GR01 | Patent grant |