CN-121980470-A - Double-source residual heat electric thermal decoupling method for coal-fired unit

CN121980470ACN 121980470 ACN121980470 ACN 121980470ACN-121980470-A

Abstract

The invention relates to the technical field of dual-source waste heat recovery cooperative control of coal-fired units, and discloses a dual-source waste heat thermal decoupling method of a coal-fired unit; the method is used for solving the problems of lack of an online judging mechanism of a recovery window, a unified gating mechanism of heat taking constraint and a stable switching and abnormal degradation recovery mechanism of an operation mode in the traditional method, and comprises the steps of establishing an operation session freezing data caliber, a threshold value and a safety boundary version, determining a smoke side and cold side waste heat allowable gear and a combination relation by a short window and a long window, obtaining a priority path based on main and standby point switching, quality code screening and a descending threshold, incorporating safety boundaries such as vacuum backpressure and the like, heat supply constraint and equipment protection into priority gating, matching action limit values and maintenance parameters according to reason codes, and carrying out state machine management mode application, verification, step-by-step, confirmation and rollback, abnormal time grading degradation, isolation and recovery calibration, and obtaining the electric thermal decoupling operation with stable heat supply and controlled safety boundary.

Inventors

WANG CHENGWEN
HUANG JIAN
WANG GUANGSHENG
LV WANG
SHI YUNFENG
WANG PENG
SUN YAN
XU JUNZHE
LI JIAWEI
ZHAO MENG
FANG WENJUN
SUN TAO
WU LIANDONG
LIAO GUOQUAN
LV RUIMING
MA JUN
HAN PING
ZHANG PENG
LIU HUANZHI
MA YUNLONG
MA YUE
ZHANG CHAO
ZHU LIN

Assignees

天津市热力有限公司
天津华能杨柳青热电有限责任公司

Dates

Publication Date: 20260505
Application Date: 20260331

Claims (10)

1. The double-source residual heat electric thermal decoupling method for the coal-fired unit is characterized by comprising the following steps of: S1, establishing an operation session, fixing a threshold value and a safety boundary version, accessing a flue gas side, a cold end side, a heat supply network side, a unit safety side and equipment state input, completing time alignment and data validity marking, and forming a session freezing table and an input validity table; S2, determining a smoke waste heat recovery allowable range, a cold end waste heat taking allowable range, a dual-source combination allowable range and an electrothermal decoupling allowable state in a preset time window according to a session freezing table and an input validity table, and generating judgment information; S3, uniformly gating equipment protection again according to the judging information and the sequence of the unit safety boundary priority and the heat supply constraint, and giving out actions allowed to be executed in the period, corresponding electric heating decoupling adjustment directions, and change limit values and retention time thereof; S4, triggering operation mode switching according to the allowable executing action and the electrothermal decoupling adjustment direction in the period and combining load change, backwater change and safety margin change, sequentially completing switching verification, step-by-step execution, switching confirmation and necessary rollback, and recording process information; S5, when data abnormality, boundary overrun or abnormal execution occurs, performing hierarchical degradation processing according to the type of the abnormality, completing recovery calibration under the limitation of relevant action isolation, bottom protection operation and decoupling capacity, and recording abnormality information.
2. The dual-source electrothermal decoupling method for a coal-fired unit according to claim 1, wherein S1 comprises: During initialization, a data dictionary is loaded, the upper limit of a measuring range is checked, and entries containing time marks, codes, numerical values, units, quality codes and sources are received according to key points and extension points; completing validity marking according to the unit consistency, the range threshold, the amplitude threshold and the steady-state criterion; a fixed load segment safety boundary, a risk classification threshold and a pressure drop end difference baseline; and setting an alignment tolerance and maintenance rule according to a sampling period, and writing a conservative starting mark when the data quality condition is met.
3. The method for double-source electrothermal decoupling of coal-fired unit according to claim 1, wherein determining the allowable range of flue gas waste heat recovery, the allowable range of cold-end waste heat taking, the allowable range of double-source combination and the allowable state of electrothermal decoupling in a preset time window according to the session freezing table and the input validity table in S2 comprises: the preset time window is configured by adopting a short window and a long window in a linkage way; selecting a measuring point according to the priority of the main measuring point and the standby measuring point, switching the standby measuring point when the main measuring point is abnormal, and completing window statistics by combining quality code screening and weight-reducing threshold; And determining a smoke gear, a cold end gear, a combined synergistic relationship, a priority path and an electrothermal decoupling permission state according to the temperature margin, the vacuum back pressure relative margin, the safety belt and the pressure drop end difference deterioration mark.
4. The dual-source electrothermal decoupling method for a coal-fired unit according to claim 1, wherein the generating of the determination information in S2 includes: The judging information is written into an event log in a structured result package, and the result package at least comprises judging time, each gear, a priority path, a decoupling permission state, a decoupling adjustment direction label, a trigger abstract, a threshold reference version, a reason code, a forbidden maintenance field, an available temperature difference threshold state, an equivalent recovery depth index reference mark, measuring point switching information, a weight reduction information and a pressure drop end difference deterioration mark; And when the key input is missing, generating a result packet according to the conservation and collaboration restriction rule, and recording the missing reason code.
5. The method for double-source electrothermal decoupling of coal-fired unit according to claim 1, wherein in S3, unified gating is performed according to the order of unit safety boundary priority, heat supply constraint and equipment protection again according to the determination information, comprising: The unified gating adopts a fixed arbitration chain with a safety boundary, heat supply constraint and equipment protection; Triggering a hard constraint arbitration when the margin enters the buffer or the input availability level is below a threshold level; And searching a gating mapping table according to the reason code, determining a forbidden type, a tightening coefficient, a retention time coverage parameter, a cooperative branch authorization condition and a corresponding decoupling adjustment direction, and writing a hit entry number in a gating record.
6. The method for double-source electrothermal decoupling of coal-fired unit according to claim 1, wherein the step S3 of providing the action allowed to be executed in the present period, the corresponding electrothermal decoupling adjustment direction, and the variation limit and the holding time thereof comprises: generating an action item and an action boundary table in the period, wherein the action item at least comprises an action object, a target direction, a decoupling adjustment direction, a single change limit value, a short window cumulative change limit value, a holding time length and a precondition; Setting the upper limit of the total heat extraction rate according to the combination allowable gear, the priority path and the decoupling allowable state, generating an action instruction packet, writing the action instruction packet into an execution queue and setting the effective period of the instruction; And prohibiting the reverse switching instruction from being issued to the same action object before the duration of the hold is not expired, and only allowing the emergency reducing instruction to be issued and writing the emergency mark when the safety boundary enters the out-of-range or emergency interval.
7. The method for double-source electrothermal decoupling of coal-fired unit according to claim 1, wherein the step S4 of triggering the operation mode switching according to the allowable action and electrothermal decoupling adjustment direction in the period and combining the load change, the backwater change and the safety margin change comprises the following steps: The mode switching trigger is used for carrying out joint judgment based on the load change rate, the return water temperature change rate, the vacuum margin, the back pressure margin and the buffer area state of the acid dew point protection margin; when the joint judgment is satisfied, further combining a combination permission gear, a decoupling permission state, a pressure drop level, an end difference attenuation level, a condensate risk level and execution object availability to determine a candidate mode, and forming a necessary action object set; The candidate pattern is written into the handover candidate record and an association flag is established with the threshold version of the session freeze table.
8. The dual-source electrothermal decoupling method for coal-fired units according to claim 1, wherein the step S4 sequentially completes the switching verification, the step execution, the switching confirmation and the necessary rollback, and records the process information, and the method comprises the steps of: performing short window continuous satisfaction check and key input quality code check on the candidate mode, and performing availability check and action reachability check on the necessary action object; When the verification fails, tightening the action boundary according to the conservative tightening coefficient table, and writing the candidate mode into the forbidden set; when the verification passes, issuing a control instruction according to preset step intervals, and continuously rechecking a heating constraint and a safety boundary in a confirmation window; and when the rechecking fails, executing rollback and writing a short-time forbidden mark and a structured switching record.
9. The dual-source electrothermal decoupling method for the coal-fired unit according to claim 1, wherein when the data abnormality, the boundary overrun or the execution abnormality occurs in S5, the hierarchical degradation process is executed according to the abnormality type, comprising: setting mutually exclusive priorities of boundary abnormality, execution abnormality, equipment abnormality and data abnormality by hierarchical degradation, and triggering a criterion to refer to a session freezing table; The data abnormality is judged according to the key point missing, the numerical value out-of-range, the time deviation grading and the continuous unchanged, and the freezing mode is switched after triggering; The boundary abnormality converges and takes heat according to the take-over sequence and enables bypass and alternative paths; the execution exception marks the corresponding execution object as unavailable and the set of reachable actions is recalculated accordingly.
10. The method for double-source electrothermal decoupling of coal-fired unit according to claim 1, wherein the step of S5 is performed with the relevant action isolation, bottom-protecting operation and recovery calibration under decoupling capacity limitation, and recording the abnormal information, comprising: Generating an abnormal information packet, an isolation list, a bottom protection action packet and a recovery condition set; the isolation list contains an isolated object, a reason code, an effective time, a minimum maintenance time and a forbidden condition, and establishes association with a degradation mode mapping table; After the abnormality is relieved, judging to disable and execute recovery calibration according to the linkage of the short window and the stable window, and writing the pressure drop baseline, the end difference baseline, the backwater bandwidth and the feedback deviation of the execution object into a candidate parameter table; The evidence abstract and the threshold version adopt batch submission to write the event log.

Description

Double-source residual heat electric thermal decoupling method for coal-fired unit Technical Field The invention relates to the technical field of collaborative control of dual-source waste heat recovery of a coal-fired unit, in particular to a dual-source waste heat electric thermal decoupling method of the coal-fired unit. Background The coal-fired unit bears the dual tasks of power supply and heat supply, gradually normalizes with deep peak shaving of a power grid and rapid fluctuation of a heat supply network load, and still needs to keep the stability of external heat supply under the conditions of low load, rapid climbing and frequent working condition switching, the prior art generally recovers heat from two types of waste heat, namely, on one hand, the waste heat of flue gas at the smoke discharging side of a boiler is usually obtained through low-temperature heat exchange and condensation recovery, and the sensible heat and the latent heat of water vapor are obtained, on the other hand, the waste heat of a condenser or the waste heat of circulating water at the cold end side of a steam turbine is usually extracted through a heat exchange device or a heat pump device and is output to the heat supply side, and in order to improve the heat supply peak shaving capacity, a part of the scheme is introduced with thermal decoupling transformation, for example, the disclosed invention patent application CN107178398B discloses a thermal decoupling system for improving the energy utilization quality of a thermal power plant, decoupling operation of the power production and heat supply process is realized through components such as a bypass and a heater, and the disclosed invention patent application CN112128732B discloses a waste steam and waste heat quality coupling lifting system for waste heat recovery and waste heat and quality lifting system; However, the traditional scheme mainly uses equipment structure integration or single loop adjustment, when the coal-fired unit is in deep peak regulation and the backwater temperature of a heat supply network fluctuates rapidly, the temperature grade and the heatable capacity of the flue gas condensation waste heat and the condenser or the circulating water waste heat can synchronously fluctuate along with the load change, the environment temperature change, the backwater temperature change and the fouling degree of a heat exchange surface, so that the recoverable range of the waste heat and the available heating capacity are difficult to determine timely and accurately, on the other hand, the heat taking at the cold end of the condenser can influence the safe operation boundaries such as unit vacuum, back pressure and the like, the flue gas condensation recovery is also influenced by the limit of the acid dew point and the fouling attenuation, the available boundary and the operation constraint of the system under different working conditions are frequently changed, the traditional control mode usually adopts a fixed set value or relies on a manual switching operation mode, the on-line judgment of the waste heat recovery window is lack of the unified gate control of the heat taking quantity, the safe boundary of the vacuum back pressure and the heating quality constraint of the heat recovery mode, and the closed loop coordination control mechanism supporting the stable switching of the multi-operation mode and the degradation recovery of the abnormal working conditions is easy to occur, the phenomena such as the fluctuation of the heating temperature, the vacuum degradation of the unit or the rise of the auxiliary energy consumption and the like are difficult to stably and repeatedly implement within the range, the stable and the stable operation, the stable operation of the thermal recovery mode can be realized, the stable and the safe operation can be achieved, and the safe and the thermal recovery control mode can realize the safe and the control and the stable control and the control. Disclosure of Invention Aiming at the defects of the prior art, the invention provides a double-source waste heat electric thermal decoupling method of a coal-fired unit, which solves the problems of lack of an on-line judging mechanism for a recovery window, a unified gating mechanism for heat taking constraint and a stable switching and abnormal degradation recovery mechanism for an operation mode in the traditional method. In order to achieve the above purpose, the present invention provides the following technical solutions: A double-source residual heat electric thermal decoupling method of a coal-fired unit comprises the following steps: S1, establishing an operation session, fixing a threshold value and a safety boundary version, accessing a flue gas side, a cold end side, a heat supply network side, a unit safety side and equipment state input, completing time alignment and data validity marking, and forming a session freezing table and an input validity table; S2, determ