An optimization method for high back pressure heat supply unit participating in flexible regulation of power grid

Abstract

An optimization method for high back pressure heat supply unit participating in flexible adjustment of power grid, the adjustable electric load adjustment interval of the unit with extraction steam turbine is calculated by the proposed simplified formula, and the optimization method for supplementing heat load is proposed according to the type of heat load for the unit without extraction steam turbine, and the electric load adjustment interval of the unit is further determined by the linear characteristics of unit output and heat load under rated back pressure and the correction coefficient of industrial extraction steam. Data support is provided for the dispatching department to issue dispatching instructions, and partial 'thermal and electric decoupling' is realized by supplementing the heat load source of high back pressure unit, and the power supply and new energy consumption capacity are improved.

Description

Technical Field

[0001] This invention relates to the field of power grid dispatching technology, specifically to an optimized method and dispatching system for high back-pressure heating units to participate in flexible power grid regulation. Background Technology

[0002] In the context of a new power system dominated by new energy sources, with the large-scale integration of photovoltaic and wind power into the grid, the grid will need larger capacity and more flexible peak-shaving resources as the basis for ensuring a stable and orderly power supply, due to the strong randomness, volatility and anti-peak-shaving characteristics of new energy power generation.

[0003] To promote the consumption of new energy sources and ensure power supply, coal-fired power units will undertake the dual tasks of deep peak shaving and power supply guarantee in the future, gradually transforming from a power-generating source to a regulating source. During the 14th Five-Year Plan period, the proportion of coal-fired power generation is expected to drop below 60%, which will pose a significant challenge to the balance of power supply and demand.

[0004] The high back pressure heating unit is constructed by modifying the low-pressure cylinder rotor of the pure condensing unit, increasing the exhaust pressure of the low-pressure cylinder from 4.9 kPa to about 54 kPa, corresponding to a saturation temperature of about 80°C. The exhaust steam is used to directly heat the circulating water for external heating. In this way, all the waste heat from the exhaust steam of the unit is carried away by the circulating water for heating, and the loss of the cold source is zero, which greatly improves the economic efficiency of the unit.

[0005] High back-pressure heating units operate under a "heat-driven power generation" mode during the heating season, without undertaking peak-shaving tasks, resulting in a near-linear load trend. The higher the heating load, the higher the corresponding electrical load. After the upgrade, due to increased exhaust pressure, the maximum output under high back-pressure operation can only reach about 80% of the pure condensing capacity, failing to fully utilize the system regulation role of coal-fired power units. Currently, the large peak-valley difference in the power grid makes it difficult to meet the flexible regulation needs of the grid by relying solely on pure condensing and extraction-condensing thermal power units. Therefore, the participation of high back-pressure heating units in flexible grid regulation is an inevitable trend. Summary of the Invention

[0006] In order to overcome the shortcomings of the above technologies, the present invention provides a method that enables high back pressure heating units to meet the needs of flexible grid regulation.

[0007] The technical solution adopted by this invention to overcome its technical problems is:

[0008] An optimized method for high back-pressure heating units to participate in flexible grid regulation includes the following steps:

[0009] a) During the non-heating season, high back pressure heating units operate under pure condensing conditions, and high back pressure heating units are pure condensing units with increased back pressure. Determine the electrical load adjustment range that can be used as a reference by the dispatching department under pure condensing conditions.

[0010] b) Calculate the following correction factors for the output limits of pure condensing units: y1 for the upper limit of output when the air extraction point is before the reheat cold section, y1′ for the lower limit of output when the air extraction point is before the reheat cold section, y2 for the upper limit of output when the air extraction point is in the reheat cold section, y2′ for the lower limit of output when the air extraction point is in the reheat cold section, y3 for the upper limit of output when the air extraction point is in the reheat hot section or after the reheat hot section, and y3′ for the lower limit of output when the air extraction point is in the reheat hot section or after the reheat hot section.

[0011] c) Calculate the upper limit of the theoretical output of the unit, P, considering industrial heat load. x and the lower limit of the theoretical output of the unit P y The adjustable electrical load range for high back pressure heating units is [P]. x ,P y ];

[0012] d) During the heating season, if the high back pressure heating unit operates with its own steam extraction, calculate the change in the unit output ΔP caused by the increased steam extraction.

[0013] e) During the heating season, if the high back pressure heating unit does not have its own steam extraction function when it is running, calculate the constraints in the process of compensating for the heating load.

[0014] f) If the heat load is an industrial heat load, then according to the heat user's requirements for the quality of industrial gas, the industrial steam extraction requirements can be met by drilling holes for steam extraction or by high and low pressure bypass heating, or by adding a gas booster.

[0015] g) During the heating season, high back pressure heating units that do not have their own steam extraction can maintain the dynamic balance of the unit's external heat load by dynamically adjusting and supplementing the heating load. The actual instantaneous external heating load of a high back pressure heating unit is the difference between its total external heat load and the supplementary heating load.

[0016] h) Calculate the correction factor P for the actual upper limit of output of the high back pressure heating unit. x ′ and the correction factor P corresponding to the actual upper limit of output of the high back pressure heating unit y The adjustable electrical load range for high back pressure heating units is [P]. x ′,P y ′).

[0017] Furthermore, a) includes the following steps:

[0018] In a-1), without considering industrial heat load and under the constraints of boiler combustion stability, the electrical load adjustment range of pure condensing units is 50%-100% of the unit's rated capacity.

[0019] a-2) If the pure condensing unit passes the three-modification linkage flexibility transformation and acceptance, the electrical load adjustment range is 30%-100% of the unit's rated capacity.

[0020] Further, in step b), the upper limit correction coefficient y1 for the output of the condensing unit before the reheat cold section is calculated using the formula y1=(h-h1+h2-h3) / 3600, where h is the extraction enthalpy corresponding to the actual extraction position of the condensing unit, h1 is the exhaust enthalpy of the low-pressure cylinder, h2 is the enthalpy of the reheat hot section, and h3 is the enthalpy of the reheat cold section. The lower limit correction coefficient y1′ for the output of the condensing unit before the reheat cold section is calculated using the formula y1′=(h4-h) / 3600, where h4 is the main steam enthalpy. The upper limit correction factor y2 for the output of the pure condensing unit when the pumping position is in the reheat cold section is calculated using the formula y2′=(h4-h3) / 3600. The upper limit correction factor y3 for the output of the pure condensing unit when the pumping position is in the reheat hot section or after the reheat hot section is calculated using the formula y3′=(h-h1) / 3600. The lower limit correction factor y3′ for the output of the pure condensing unit when the pumping position is in the reheat hot section or after the reheat hot section is calculated using the formula y3′=(h4-h+h2-h3) / 3600.

[0021] Furthermore, in step c), formula P... x =P1-y1*t1-y2*t2-y3*t3 The theoretical upper limit of the unit's output power, P, is calculated considering industrial heat load. x In the formula, t1 is the industrial extraction steam rate when the extraction point of the pure condensing unit is before the reheat cold section, t2 is the industrial extraction steam rate when the extraction point of the pure condensing unit is in the reheat cold section, t3 is the industrial extraction steam rate when the extraction point of the pure condensing unit is in or after the reheat hot section, and P1 is the upper limit of the unit output corresponding to the pure condensing unit under pure condensing conditions, which is obtained through formula P y =P2+y1′*t1+y2′*t2-y3′*t3 The theoretical lower limit value P of the unit's output considering industrial heat load is obtained by calculation. y P2 is the lower limit of the unit output of the pure condensing unit under pure condensing conditions.

[0022] Preferably, under pure condensing conditions, the upper limit of the unit output P1 corresponding to the pure condensing unit is 100% of the rated capacity of the pure condensing unit. If the pure condensing unit completes the three-modification linkage flexibility modification, then the lower limit of the unit output P2 corresponding to the pure condensing unit under pure condensing conditions is 30% of the rated capacity of the pure condensing unit. If the pure condensing unit has not completed the three-modification linkage flexibility modification, then the lower limit of the unit output P2 corresponding to the pure condensing unit under pure condensing conditions is 50% of the rated capacity of the pure condensing unit.

[0023] Furthermore, through the formula The change in unit output ΔP due to increased steam extraction of the high back pressure heating unit was calculated, where d is the amount of steam extracted for heating, h1′ is the enthalpy of steam extracted for heating, and h2′ is the enthalpy of steam exhausted for heating.

[0024] Furthermore, in step e), formula T min ≤T k,t ≤T max and T k,t -T k,t-1 ≤T establishes constraints in the process of compensating for heating load, where T max T represents the upper limit of indoor temperature for residents during winter. min T represents the lower limit of indoor temperature for residents during winter. k,t T represents the indoor temperature of residents at time t during the heating season. k,t-1 The indoor temperature of residents at time t-1 during the heating season is denoted as T, where T is the maximum allowable change in indoor temperature within a certain time interval.

[0025] Furthermore, in step h), formula P x ′=P-y1*t1-y2*t2-y3*t3 Calculate the correction factor P corresponding to the actual upper limit of output of the high back pressure heating unit. x ′, through formula P y '=P+y1'*t1+y2'*t2-y3'*t3 Calculate the correction factor P corresponding to the actual upper limit of output of the high back pressure heating unit. y ′, P is the real-time output value of the unit obtained by inputting the actual instantaneous external heating load.

[0026] The beneficial effects of this invention are: providing data support for power grid dispatching departments to issue dispatching instructions, achieving partial "thermal-electric decoupling" by supplementing the heat load source of high back-pressure units, improving power supply and new energy consumption capabilities, and contributing to the construction of a new power system. Attached Figure Description

[0027] Figure 1 This is a flowchart of the method of the present invention;

[0028] Figure 2 This is a load characteristic diagram of a high back pressure heating unit under rated back pressure according to the present invention. Detailed Implementation

[0029] The following is in conjunction with the appendix Figure 1 Appendix Figure 2 The present invention will be further described below.

[0030] The traditional dispatching mode for high back-pressure heating units during the heating season is based on a "heat-driven power generation" model, which does not undertake peak-shaving tasks. The load trend is almost a straight line, failing to fully utilize the system regulation role of coal-fired power units. Currently, the peak-valley difference in the power grid during the heating season is significant, and relying solely on pure condensing and extraction-condensing thermal power units is insufficient to meet the grid's flexible regulation needs. Therefore, the participation of high back-pressure heating units in grid regulation is an inevitable trend. Therefore, as shown in the attached... Figure 1 As shown, this invention proposes an optimized method for high back-pressure heating units to participate in flexible grid regulation, comprising the following steps:

[0031] a) During the non-heating season, high back-pressure heating units operate under pure condensing conditions, which allows for peak shaving. If a high back-pressure heating unit operates under high back pressure during the heating season and pure condensing conditions during the non-heating season, the requirements for deep peak shaving can be met. Since high back-pressure heating units are pure condensing units with increased back pressure, a reference range for electrical load adjustment under pure condensing conditions should be determined for dispatching departments.

[0032] b) Based on the heat users' requirements for industrial steam extraction quality, the industrial steam extraction location of the unit can generally be divided into the following three categories: (1) the extraction location of the pure condensing unit is before the reheat cold section; (2) the extraction location of the pure condensing unit is in the reheat cold section; and (3) the extraction location of the pure condensing unit is in the reheat hot section or after the reheat hot section. Calculate the upper limit correction coefficient y1 for the pure condensing unit extraction location before the reheat cold section, the lower limit correction coefficient y1′ for the pure condensing unit extraction location before the reheat cold section, the upper limit correction coefficient y2 for the pure condensing unit extraction location in the reheat cold section, the lower limit correction coefficient y2′ for the pure condensing unit extraction location in the reheat cold section, the upper limit correction coefficient y3 for the pure condensing unit extraction location in the reheat hot section or after the reheat hot section, and the lower limit correction coefficient y3′ for the pure condensing unit extraction location in the reheat hot section or after the reheat hot section.

[0033] c) Calculate the upper limit of the theoretical output of the unit, P, considering industrial heat load. x and the lower limit of the theoretical output of the unit P y Under the current actual instantaneous external industrial heat load, the adjustable electrical load range of the high back-pressure heating unit is [P]. x ,P y ].

[0034] d) Under high back pressure operation during the heating season, if the high back pressure heating unit has its own extraction steam, it can reduce the unit's output to participate in peak shaving by increasing the extraction steam while keeping the main steam flow unchanged. This allows it to participate in peak shaving while ensuring that the external heat supply remains basically unchanged. Depending on the extraction steam location, the degree of impact on the unit's output capacity from increasing extraction steam varies. The change in unit output ΔP due to increased extraction steam can be calculated. Calculations show that the high back pressure unit with extraction steam has a certain peak shaving capacity, with a load adjustment range of approximately 10% of the rated load.

[0035] e) During the heating season, if the high back-pressure heating unit operates without its own steam extraction, the traditional dispatching mode for such units is based on a "heat-driven power generation" model. Constrained by residential heating demands, these units cannot participate in grid peak shaving. This invention supplements the heat load through the following optimization method and further determines the unit's electrical load adjustment range, providing data support for the grid dispatching department. If the heat load is for heating purposes, based on residents' heating experience needs, methods such as adding heat pumps, steam extraction bypasses, electric boilers, and thermal storage tanks are used to meet the heating load requirements. These methods compensate for the constraints in the heating load process.

[0036] f) If the heat load is industrial, then based on the heat users' requirements for industrial gas quality, methods such as perforated steam extraction or high / low pressure bypass heating, and the installation of gas booster compressors, can be used to meet the industrial steam extraction needs. Through these methods, the needs of both heating and industrial heat users can be met, achieving a certain degree of "thermal-electric decoupling," ensuring heating supply while also considering grid peak shaving.

[0037] g) During the heating season, high-back-pressure heating units that do not have their own steam extraction capabilities maintain a dynamic balance with the external heat load by dynamically adjusting and supplementing the heating load. The actual instantaneous external heating load of a high-back-pressure heating unit is the difference between its total external heat load and the supplementary heating load. (See attached...) Figure 2 As shown, under rated back pressure, the power generation of a high back pressure unit increases with the increase of main steam flow, the exhaust steam flow of the low-pressure cylinder increases, and the heating load also increases accordingly. That is, the heating load and unit output have a linear relationship, and this linear relationship can be fitted by different heating loads and corresponding unit outputs. By inputting the actual instantaneous external heating load of the unit, the electrical load under high back pressure operating conditions can be obtained.

[0038] h) The above method is used to dynamically adjust the supplementary industrial heat load to maintain the dynamic balance of the unit's external industrial heat load. The actual instantaneous external industrial heat load of the unit is the difference between the unit's total external industrial steam extraction and the supplementary heating industrial steam extraction. Calculate the correction factor P corresponding to the actual upper limit of output of the high back-pressure heating unit. x′ and the correction factor P corresponding to the actual upper limit of output of the high back pressure heating unit y The adjustable electrical load range for high back pressure heating units is [P]. x ′,P y ′).

[0039] This invention proposes a scheduling module for the electrical load adjustment range of high back-pressure units during pure condensing operation in the non-heating season. An optimized method for high back-pressure units to participate in flexible grid regulation under high back-pressure operation conditions during the heating season is also proposed:

[0040] (1) The adjustable electrical load range of the unit is calculated by the simplified formula proposed for the unit with its own extraction steam turbine.

[0041] (2) For units without their own extraction steam turbines, optimization methods for supplementary heat load are proposed according to the heat load type. Furthermore, the unit's electrical load adjustment range is determined by the linear characteristics of unit output and heat load under rated back pressure and the industrial extraction steam correction coefficient. [P] x ′,P y ′).

[0042] Example 1:

[0043] a) Includes the following steps:

[0044] In a-1), without considering industrial heat load and under the constraints of boiler combustion stability, the electrical load adjustment range of pure condensing units is 50%-100% of the unit's rated capacity.

[0045] a-2) If a pure condensing unit undergoes a three-stage linkage flexibility upgrade and passes acceptance, it can be further dispatched according to the local requirements for deep peak shaving after the flexibility upgrade. Currently, in Shandong Province, after a pure condensing unit undergoes a flexibility upgrade and passes acceptance, the electrical load adjustment range is 30%-100% of the unit's rated capacity.

[0046] Example 2:

[0047] In step b), the upper limit correction coefficient y1 for the output of the condensing unit before the reheat cold section is calculated using the formula y1=(h-h1+h2-h3) / 3600, where h is the extraction enthalpy corresponding to the actual extraction position of the condensing unit, h1 is the exhaust enthalpy of the low-pressure cylinder, h2 is the enthalpy of the reheat hot section, and h3 is the enthalpy of the reheat cold section. The lower limit correction coefficient y1′ for the output of the condensing unit before the reheat cold section is calculated using the formula y1′=(h4-h) / 3600, where h4 is the main steam enthalpy. The upper limit correction factor y2 for the output of the pure condensing unit when the extraction point is in the reheat cold section is calculated. The lower limit correction factor y2′ for the output of the pure condensing unit when the extraction point is in the reheat cold section is calculated using the formula y2′=(h4-h3) / 3600. The upper limit correction factor y3 for the output of the pure condensing unit when the extraction point is in the reheat hot section or after the reheat hot section is calculated using the formula y3=(h-h1) / 3600. The lower limit correction factor y3′ for the output of the pure condensing unit when the extraction point is in the reheat hot section or after the reheat hot section is calculated using the formula y3′=(h4-h+h2-h3) / 3600. The enthalpy values ​​for the above different locations can be obtained by consulting the steam-water enthalpy-entropy diagram based on the corresponding pressure and temperature.

[0048] Example 3:

[0049] In step c), formula P x =P1-y1*t1-y2*t2-y3*t3 The theoretical upper limit of the unit's output power, P, is calculated considering industrial heat load. x In the formula, t1 is the industrial extraction steam rate when the extraction point of the pure condensing unit is before the reheat cold section, t2 is the industrial extraction steam rate when the extraction point of the pure condensing unit is in the reheat cold section, t3 is the industrial extraction steam rate when the extraction point of the pure condensing unit is in or after the reheat hot section, and P1 is the upper limit of the unit output corresponding to the pure condensing unit under pure condensing conditions, which is obtained through formula P y =P2+y1′*t1+y2′*t2-y3′*t3 The theoretical lower limit value P of the unit's output considering industrial heat load is obtained by calculation. y P2 represents the lower limit of the unit output for a pure condensing unit under pure condensing conditions. t1, t2, and t3 can be obtained by querying the DCS data to determine the actual industrial steam extraction rate of the unit.

[0050] Example 4:

[0051] Under pure condensing conditions, the upper limit of the unit output P1 corresponding to the pure condensing unit is 100% of the rated capacity of the pure condensing unit. If the pure condensing unit has completed the three-modification linkage flexibility modification, the lower limit of the unit output P2 corresponding to the pure condensing unit under pure condensing conditions is 30% of the rated capacity of the pure condensing unit. If the pure condensing unit has not completed the three-modification linkage flexibility modification, the lower limit of the unit output P2 corresponding to the pure condensing unit under pure condensing conditions is 50% of the rated capacity of the pure condensing unit.

[0052] Example 5:

[0053] Through formula The change in unit output ΔP due to increased steam extraction of the high back pressure heating unit was calculated, where d is the amount of steam extracted for heating, h1′ is the enthalpy of steam extracted for heating, and h2′ is the enthalpy of steam exhausted for heating.

[0054] Example 6:

[0055] In step e), through formula T min ≤T k,t ≤T max and T k,t -T k,t-1 ≤T establishes constraints in the process of compensating for heating load, where T max T represents the upper limit of indoor temperature for residents during winter. min The minimum indoor temperature for residential heating in northern my country during winter is 16℃, which is based on 18℃ with a fluctuation of 2℃ above and below. k,t T represents the indoor temperature of residents at time t during the heating season. k,t-1 Let T be the indoor temperature of residents at time t-1 during the heating season, and T be the maximum allowable change in indoor temperature within a certain time interval.

[0056] Example 7:

[0057] In step h), formula P x ′=P-y1*t1-y2*t2-y3*t3 Calculate the correction factor P corresponding to the actual upper limit of output of the high back pressure heating unit. x ′, through formula P y '=P+y1'*t1+y2'*t2-y3'*t3 Calculate the correction factor P corresponding to the actual upper limit of output of the high back pressure heating unit. y ′, P is the real-time output value of the unit obtained by inputting the actual instantaneous external heating load.

[0058] This invention also provides a dispatching interval system for high back-pressure heating units to participate in flexible grid regulation:

[0059] Specific Example 1: This machine is a high-back-pressure heating unit with steam extraction.

[0060] Unit #1 of a certain power plant is a subcritical, single-stage intermediate reheat, single-shaft, double-cylinder double-exhaust, single-stage adjustable extraction, back-pressure steam turbine, with unit model CB320-16.67 / 0.79 / 0.054 / 538 / 538.

[0061] Taking Unit #1 of this power plant as an example, when the unit load is 260MW, the heat supply, converted to steam extraction, is 560t / h. When the unit load decreases to 230MW, the heat supply, converted to steam extraction, is 554t / h, basically maintaining the same heat supply. Therefore, this high back-pressure unit with steam extraction has a certain peak-shaving capacity while maintaining a constant heat supply. This high back-pressure unit with steam extraction has a certain peak-shaving margin, with the electrical load adjustment range being approximately 10% of the unit's rated capacity.

[0062] Specific Example 2: High-back-pressure heating unit without steam extraction

[0063] The steam turbines of Units #1 and #2 in a certain power plant are high-temperature, ultra-high-pressure, single-shaft, impulse-type, double-cylinder, double-exhaust, extraction-condensing steam turbines manufactured by Dongfang Turbine Works. Model: N150-13.24 / 535 / 535. Main parameters are shown in Table 1. Before heating supply, the low-pressure cylinder of turbine #2 was disassembled, and a 2×4-stage high back-pressure rotor and diaphragms were replaced. Guide baffles were installed at the original last-stage and second-last-stage diaphragm installation locations, and the original condenser circulating water was switched to the city heating network circulating water.

[0064] Table 1

[0065]

[0066] Taking Unit #2 of this power plant as an example, the unit has a load of 135MW and a steam extraction rate of 283t / h for heat supply. If it participates in peak shaving, the unit load drops to 84MW, and the steam extraction rate drops to 178t / h, providing only 50MW of peak shaving capacity, while the heat supply decreases by 100t / h. If the heat supply of the whole plant is to remain unchanged, Unit #1 needs to increase steam extraction by 100t / h. However, Unit #1 is an extraction condensing unit with a maximum steam extraction rate of 180t / h, which is difficult to increase by 100t / h to maintain the heat supply of the whole plant. Even if the steam extraction rate can be increased by 100t / h, Unit #1 will basically lose its peak shaving capacity.

[0067] To enable the high back-pressure heating unit to participate in flexible grid regulation, the power plant has built an electric boiler to achieve "thermal-electric decoupling". It is known that the electric boiler can supplement 150t / h of heating steam extraction, which can provide a peak-shaving capacity of 73MW when converted to the unit output.

[0068] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An optimized method for high back-pressure heating units to participate in flexible grid regulation, characterized in that, Includes the following steps: a) During the non-heating season, high back pressure heating units operate under pure condensing conditions, and high back pressure heating units are pure condensing units with increased back pressure. Determine the electrical load adjustment range that can be used as a reference by the dispatching department under pure condensing conditions. b) Calculate the upper limit correction factor for the output of the pure condensing unit when the extraction point is before the reheat cooling section. Correction factor for the lower limit of output of pure condensing unit with extraction air position before reheat cooling section Correction factor for the upper limit of output of pure condensing unit with extraction air location in reheat cold section. Correction factor for the lower limit of output of pure condensing unit with extraction gas location in reheat cooling section. Correction factor for the upper limit of output of pure condensing unit with extraction gas location in or after the reheat section. Correction factor for the lower limit of output of pure condensing unit with extraction gas location in or after the reheat section. ; c) Calculate the upper limit of the theoretical output of the unit considering industrial heat load. and the lower limit of the theoretical output of the unit The high back pressure heating unit can adjust the electrical load range to ; d) During the heating season, if the high back-pressure heating unit operates with its own steam extraction, calculate the change in unit output caused by the increased steam extraction. ; e) During the heating season, if the high back pressure heating unit does not have its own steam extraction function when it is running, calculate the constraints in the process of compensating for the heating load. f) If the heat load is an industrial heat load, then according to the heat user's requirements for the quality of industrial gas, the industrial steam extraction requirements can be met by drilling holes for steam extraction or by high and low pressure bypass heating, or by adding a gas booster. g) During the heating season, high back pressure heating units that do not have their own steam extraction can maintain the dynamic balance of the unit's external heat load by dynamically adjusting and supplementing the heating load. The actual instantaneous external heating load of a high back pressure heating unit is the difference between its total external heat load and the supplementary heating load. h) Calculate the correction factor for the actual upper limit of output of the high back pressure heating unit. Correction coefficient for the actual upper limit of output of high back pressure heating units The high back pressure heating unit can adjust the electrical load range to ; In step c), the formula is used. The theoretical upper limit of the unit's output was calculated considering industrial heat load. In the formula This refers to the industrial steam extraction rate when the extraction point of a pure condensing unit is before the reheat cooling section. This refers to the industrial steam extraction rate when the extraction point of a pure condensing unit is in the reheat cooling section. This refers to the industrial steam extraction rate when the extraction point of a pure condensing unit is in or after the reheat section. This represents the upper limit of the unit output for a pure condensing unit under pure condensing conditions, calculated using the formula... The calculation yielded the lower limit of the theoretical output of the unit considering industrial heat load. , This represents the lower limit of the unit output of a pure condensing unit under pure condensing operating conditions. In step e), the formula is used. and Establish constraints in the process of compensating for heating load, where This refers to the upper limit of indoor temperature for residents during winter. This represents the lower limit of indoor temperature for residents during winter. For the heating season The indoor temperature of the residents at any time For the heating season The indoor temperature of the residents at any time The maximum allowable change in indoor temperature within a certain time interval; In step h), the formula is used. Calculate the correction factor for the actual upper limit of output of the high back pressure heating unit. Through formula Calculate the correction factor for the actual upper limit of output of the high back pressure heating unit. , The real-time output value of the unit is obtained by inputting the actual instantaneous external heating load.

2. The optimized method for high back-pressure heating units to participate in flexible grid regulation according to claim 1, characterized in that, Step a) includes the following steps: In a-1), without considering industrial heat load and under the constraints of boiler combustion stability, the electrical load adjustment range of pure condensing units is 50%-100% of the unit's rated capacity. a-2) If the pure condensing unit passes the three-modification linkage flexibility transformation and acceptance, the electrical load adjustment range is 30%-100% of the unit's rated capacity.

3. The optimized method for high back-pressure heating units to participate in flexible grid regulation according to claim 1, characterized in that: In step b), the formula is used. The calculation yields the upper limit correction factor for the output of the pure condensing unit when the extraction point is before the reheat cooling section. In the formula This represents the extraction enthalpy corresponding to the actual extraction location of the condensing unit. For the exhaust enthalpy of the low-pressure cylinder, For the enthalpy of reheating, The enthalpy of the reheat cold section is obtained through the formula. The calculation yields the lower limit correction factor for the output of the pure condensing unit when the extraction point is before the reheat cooling section. In the formula, The main vapor enthalpy, obtained through the formula The calculation yields the upper limit correction factor for the output of the pure condensing unit with the extraction point in the reheat cooling section. Through formula The calculation yields the lower limit correction factor for the output of the pure condensing unit at the extraction point in the reheat cooling section. Through formula The calculated correction factor for the upper limit of output of the pure condensing unit when the extraction point is in or after the reheat zone is obtained. Through formula The calculation yields the lower limit correction factor for the output of the pure condensing unit when the extraction point is in or after the reheat zone. .

4. The optimized method for high back-pressure heating units to participate in flexible grid regulation according to claim 1, characterized in that: Upper limit of unit output for pure condensing unit under pure condensing conditions For a pure condensing unit operating at 100% rated capacity, if the pure condensing unit completes the three-stage linkage flexibility modification, then the lower limit of the unit output under pure condensing conditions is... For pure condensing units operating at 30% of their rated capacity, if the three-stage linkage flexibility modification has not been completed, the lower limit of the unit output under pure condensing conditions is as follows: This is 50% of the rated capacity of the pure condensing unit.

5. The optimized method for high back-pressure heating units to participate in flexible grid regulation according to claim 1, characterized in that: Through formula The changes in unit output caused by increased steam extraction in high back-pressure heating units were calculated. In the formula This refers to the amount of steam extracted for heating. Extracting steam enthalpy for heating. For heating exhaust steam enthalpy.

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