A method and system for supplying heat to the outside based on a low-pressure cylinder of a unit

Abstract

The application discloses a method and system for supplying heat outside based on a low-pressure cylinder of a generating unit, relates to the technical field of power plant heat supply, and comprises the following steps: acquiring a running log of the low-pressure cylinder of the generating unit, analyzing the running log of the low-pressure cylinder of the generating unit, determining past power generation demand, past power supply capacity increasing rate and past unit time heat supply capacity of the low-pressure cylinder of the generating unit, and then constructing a past heat supply strategy reference model; determining an initial heat supply strategy in the past heat supply strategy reference model according to current comparison factors; performing power generation side evaluation on the initial heat supply strategy; performing heat supply side evaluation on the initial heat supply strategy; adjusting the initial heat supply strategy according to the power generation side evaluation and the heat supply side evaluation; generating an optimized heat supply strategy; and driving the low-pressure cylinder of the generating unit to supply heat outside according to the optimized heat supply strategy. The heat supply optimization strategy provided by the application can accurately judge social demand, thereby better meeting social demand.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of power plant heat supply, in particular to a method and system for external heat supply based on a low-pressure cylinder of a unit. BACKGROUND

[0002] Large-scale grid-connected power generation of intermittent energy sources such as wind energy and solar energy has reduced the peak shaving capacity ratio of the power grid system, causing difficulties in consumption of renewable energy power generation in China, and the problem of wind and light curtailment is serious in some areas. In order to effectively consume renewable energy power generation, the operational flexibility of coal-fired generating units needs to be improved.

[0003] Zero output of the low-pressure cylinder is one of the effective technologies for thermal decoupling, but in the existing zero output of the low-pressure cylinder technology, the external heat supply of the low-pressure cylinder when the subsequent unit is operating may have problems, therefore, how to optimize the external heat supply of the low-pressure cylinder of the unit is a technical problem to be solved at present.

[0004] The patent with publication number CN215890119U discloses a steam and heat supply system based on a low-pressure cylinder zero output unit, which includes a boiler and a reheater. The outlet of the boiler is connected with the inlet of a high-pressure cylinder, and the outlet of the high-pressure cylinder is connected with the reheater. The outlet of the reheater is connected with the first inlet of a pressure matcher and the inlet of a medium-pressure cylinder through pipelines. The outlet of the medium-pressure cylinder is connected with the second inlet of the pressure matcher, a water mist spray cooler and a heat exchange first station through a medium-pressure cylinder exhaust pipe. The water mist spray cooler is connected with a low-pressure cylinder, and the low-pressure cylinder is connected with a generator. The backwater of the heat exchange first station is connected with a deaerator through a pipeline. The outlet of the deaerator is connected with the inlet of the boiler through a pipeline, and the outlet of a feed water pump is connected with the pressure matcher through a pipeline. This steam and heat supply system cannot accurately judge the social demand and optimize the heat supply strategy. SUMMARY

[0005] To solve the above problems, the present application provides a method and system for external heat supply based on a low-pressure cylinder of a unit, which aims to optimize the method for external heat supply of the low-pressure cylinder of a unit of a thermal power plant.

[0006] In some embodiments of the present application, a method for external heat supply based on a low-pressure cylinder of a unit is provided, which includes: acquiring a unit low-pressure cylinder operation log, and analyzing the unit low-pressure cylinder operation log to determine past power generation demand, past power supply capacity increase rate and past unit time heat supply capacity of the unit low-pressure cylinder;

[0007] A first time reference line is established for the past power generation demand, the past power supply capacity increase rate and the past unit time heat supply capacity of the unit low-pressure cylinder, and the past power generation demand curve, the past power supply capacity increase rate curve and the past unit time heat supply capacity curve are respectively established with the first time reference line as a horizontal variable;

[0008] aligning a past power generation demand curve, a past power supply capacity increasing rate curve and a past unit time heat supply amount curve, and constructing a past heat supply strategy reference model;

[0009] determining an initial heat supply strategy in the past heat supply strategy reference model according to a comparison factor at the moment;

[0010] performing power generation emphasis evaluation on the initial heat supply strategy according to a power generation demand emphasis requirement and a power supply capacity increasing rate emphasis requirement, and performing heat supply emphasis evaluation on the initial heat supply strategy according to a unit time heat supply amount emphasis requirement;

[0011] adjusting the initial heat supply strategy according to the power generation emphasis evaluation and the heat supply emphasis evaluation, and generating an optimized heat supply strategy;

[0012] driving the low-pressure cylinder of the unit to supply heat to the outside according to the optimized heat supply strategy.

[0013] In some embodiments of the present application, the method for constructing the past heat supply strategy reference model comprises:

[0014] establishing a vertical scanning line for the past power generation demand curve, the past power supply capacity increasing rate curve and the past unit time heat supply amount curve, and determining a power generation demand first reference point, a power supply capacity increasing rate first reference point and a unit time heat supply amount first reference point as the intersection points of the vertical scanning line and the past power generation demand curve, the past power supply capacity increasing rate curve and the past unit time heat supply amount curve respectively;

[0015] determining the position of the vertical scanning line according to a comparison factor at the moment, and combining the determined power generation demand first reference point, the power supply capacity increasing rate first reference point and the unit time heat supply amount first reference point to generate an initial heat supply strategy.

[0016] In some embodiments of the present application, the method for performing power generation emphasis evaluation on the initial heat supply strategy comprises:

[0017] determining the amount of steam flowing into the low-pressure cylinder of the unit according to the initial heat supply strategy;

[0018] configuring a power generation demand emphasis evaluation conversion coefficient for the amount of steam flowing into the low-pressure cylinder of the unit according to the power generation demand emphasis requirement, and obtaining power generation demand emphasis evaluation;

[0019] configuring a power supply capacity increasing rate emphasis evaluation conversion coefficient for a first steam difference amount flowing into the low-pressure cylinder of the unit according to the power supply capacity increasing rate emphasis requirement, and obtaining power supply capacity increasing rate emphasis evaluation, wherein the first steam difference amount is the difference between the amount of steam flowing into the low-pressure cylinder of the unit and the amount of steam corresponding to the highest power supply capacity increasing rate of the low-pressure cylinder of the unit;

[0020] According to the power generation demand side evaluation and the power supply rate improvement rate side evaluation, the initial heat supply strategy power generation side evaluation is determined.

[0021] In some embodiments of the present application, the expression for calculating the initial heat supply strategy power generation side evaluation is:

[0022] The expression for calculating the initial heat supply strategy power generation side evaluation is:

[0023] ;

[0024] Wherein, is the initial heat supply strategy power generation side evaluation corresponding value of the t time node, is the power generation demand side conversion coefficient of the t time node, is the steam amount of the low-pressure cylinder of the unit entering the machine at the t time node, is the power supply rate improvement rate side evaluation conversion coefficient of the t time node, is the steam amount corresponding to the highest power supply rate improvement rate of the low-pressure cylinder of the unit.

[0025] In some embodiments of the present application, the method for performing heat supply side evaluation on the initial heat supply strategy includes:

[0026] According to the initial heat supply strategy, the steam amount of the unit entering the heat supply system is determined;

[0027] According to the unit time heat supply amount side requirement, the second steam average amount entering the heat supply system of the unit is configured with a unit time heat supply amount side evaluation conversion coefficient to obtain heat supply side evaluation, wherein the second steam average amount is the average value of the steam amount entering the heat supply system at different rates within a certain time.

[0028] In some embodiments of the present application, the expression for calculating the initial heat supply strategy heat supply side evaluation is:

[0029]

[0030] Wherein is the initial heat supply strategy heat supply side evaluation corresponding value of the t time node, is the heat supply demand side conversion coefficient of the t time node, is the steam amount of external heat supply.

[0031] In some embodiments of the present application, a standard power generation side evaluation comparison table is preset, and the standard power generation side evaluation table contains a plurality of standard power generation side evaluation values under different conditions;

[0032] The initial heat supply strategy power generation side evaluation corresponding value is compared with the standard power generation side evaluation comparison table under the same condition.

[0033] If the evaluation value of the initial heat supply strategy is less than the standard power generation side weight evaluation value, the initial heat supply strategy is optimized to obtain a secondary heat supply strategy;

[0034] If the secondary power generation side weight value obtained by analyzing the secondary optimization strategy is still lower than the standard power generation side weight evaluation value, the secondary heat supply strategy is optimized again to obtain a tertiary heat supply strategy;

[0035] If the tertiary power generation side weight value obtained by analyzing the tertiary optimization strategy still cannot reach the standard power generation side weight value, optimization is performed again.

[0036] The optimization process is provided with N times, until N+1 heat supply strategies are obtained, and the N+1 heat supply strategy analysis obtains an N+1 heat supply side weight value greater than or equal to the standard heat supply side weight value.

[0037] In some embodiments of the present application, a standard heat supply side weight evaluation comparison table is preset, and the standard heat supply side weight evaluation table contains a plurality of standard heat supply side weight evaluation values under different conditions;

[0038] The heat supply side weight evaluation corresponding value of the initial heat supply strategy is compared with the standard heat supply side weight evaluation comparison table under the same condition;

[0039] If the evaluation value of the initial heat supply strategy is less than the standard heat supply side weight evaluation value, the initial heat supply strategy is optimized to obtain a secondary heat supply strategy;

[0040] If the secondary heat supply side weight value obtained by analyzing the secondary optimization strategy is still lower than the standard heat supply side weight evaluation value, the secondary heat supply strategy is optimized again to obtain a tertiary heat supply strategy;

[0041] If the tertiary heat supply side weight value obtained by analyzing the tertiary optimization strategy still cannot reach the standard heat supply side weight value, optimization is performed again.

[0042] The optimization process is provided with N times, until N+1 heat supply strategies are obtained, and the N+1 heat supply strategy analysis obtains an N+1 heat supply side weight value greater than or equal to the standard heat supply side weight value.

[0043] In some embodiments of the present application, the heat supply strategy optimization method comprises:

[0044] The reference model of the initial heat supply strategy corresponding to the past heat supply strategy is traced back;

[0045] The past power generation demand curve, the past power supply amount improvement rate curve, and the past unit time heat supply amount curve involved in the past heat supply strategy are determined;

[0046] The nearby curve segments corresponding to the past power generation demand curve, the past power supply capacity increasing rate curve and the past unit time heat supply amount curve are identified as the optimized power generation demand curve, the power supply capacity increasing rate curve and the unit time heat supply amount curve, respectively.

[0047] The optimized power generation demand curve, the power supply capacity increasing rate curve and the unit time heat supply amount curve are matched with the vertical scanning line, the position of the vertical scanning line is determined according to the current comparison factor, the optimized power generation demand reference point, the power supply capacity increasing rate reference point and the unit time heat supply amount reference point are obtained, and thus the optimized heat supply strategy is generated by combination.

[0048] In some embodiments of the present application, a unit heat supply system based on low-pressure cylinder zero output is disclosed, comprising:

[0049] The acquisition module acquires the operation log of the low-pressure cylinder of the unit and analyzes the operation log of the low-pressure cylinder of the unit to determine the past power generation demand, the past power supply capacity increasing rate and the past unit time heat supply amount of the low-pressure cylinder of the unit.

[0050] The construction module establishes a first time reference line with respect to the past power generation demand, the past power supply capacity increasing rate and the past unit time heat supply amount of the low-pressure cylinder of the unit, and establishes the past power generation demand curve, the past power supply capacity increasing rate curve and the past unit time heat supply amount curve with the first time reference line as a horizontal variable, aligns the past power generation demand curve, the past power supply capacity increasing rate curve and the past unit time heat supply amount curve, and constructs a past heat supply strategy reference model.

[0051] The generation module generates an initial heat supply strategy in the past heat supply strategy reference model according to the current power generation demand.

[0052] The optimization module performs power generation emphasis evaluation on the initial heat supply strategy according to the power generation demand side emphasis requirement and the power supply capacity increasing rate side emphasis requirement, performs heat supply emphasis evaluation on the initial heat supply strategy according to the unit time heat supply amount side emphasis requirement, adjusts the initial heat supply strategy according to the power generation emphasis evaluation and the heat supply emphasis evaluation, and generates an optimized heat supply strategy.

[0053] The present application discloses a method and system for external heat supply based on a low-pressure cylinder of a unit, which has the following advantages in optimizing the heat supply of the low-pressure cylinder of a thermal power plant:

[0054] 1. The present application is provided with a heat supply strategy reference model, which can intuitively and stereoscopically simulate operation, so as to quickly and accurately judge social demand.

[0055] 2. The present application is provided with system optimization measures, which optimize the reference model several times, so as to better meet social demand and provide convenience for industrial heat load in the heating season.

[0056] The technical solutions of the present application are described in further detail below with reference to the accompanying drawings and examples. BRIEF DESCRIPTION OF DRAWINGS

[0057] Figure 1 A method step diagram of a method for supplying heat to the outside based on a low-pressure cylinder of a unit in an embodiment of the present application;

[0058] Figure 2 A system module schematic diagram of a method for supplying heat to the outside based on a low-pressure cylinder of a unit in an embodiment of the present application. DETAILED DESCRIPTION

[0059] The technical solutions of the present application are described in further detail below with reference to the accompanying drawings and examples.

[0060] The technical solutions of the present application are described in further detail below with reference to the accompanying drawings and examples.

[0061] Embodiment:

[0062] As Figure 1 The purpose of the present application is to provide a method for supplying heat to a unit based on zero output of a low-pressure cylinder,

[0063] Step S1, obtaining a unit low-pressure cylinder operation log, and analyzing the unit low-pressure cylinder operation log to determine past power generation demand, past power supply capacity improvement rate, and past unit time heat supply capacity of the unit low-pressure cylinder.

[0064] It can be understood that the unit low-pressure cylinder operation log can provide several data, including but not limited to past power generation demand, past power supply capacity improvement rate, and past unit time heat supply capacity, and the present method extracts the required data to facilitate the construction of a heat supply strategy reference model.

[0065] Step S2, establishing a first time reference line for the past power generation demand, past power supply capacity improvement rate, and past unit time heat supply capacity of the unit low-pressure cylinder, and establishing a past power generation demand curve, a past power supply capacity improvement rate curve, and a past unit time heat supply curve with the first time reference line as a horizontal variable, aligning the past power generation demand curve, the past power supply capacity improvement rate curve, and the past unit time heat supply curve, and constructing a past heat supply strategy reference model.

[0066] Step S3, determining an initial heating strategy in the past heating strategy reference model according to the current comparison factor.

[0067] The specific content includes establishing vertical scanning lines for the past power generation demand curve, the past power supply capacity improvement rate curve and the past unit time heat supply curve.

[0068] The intersection points of the vertical scanning lines and the past power generation demand curve, the past power supply capacity improvement rate curve and the past unit time heat supply curve are respectively identified as the power generation demand first reference point, the power supply improvement rate first reference point and the unit time heat supply first reference point.

[0069] According to the current comparison factor, the position of the vertical scanning line is determined, and the determined power generation demand first reference point, power supply improvement rate first reference point and unit time heat supply first reference point are combined to generate an initial heating strategy, thereby constructing a past heating strategy reference model.

[0070] It can be understood that the vertical scanning line corresponds to the current comparison factor, and the comparison factor is a comprehensive factor including but not limited to user demand and multi-element heat parameter demand. The above three curves correspond to the requirements of social demand on equipment, and the formation of the reference point constitutes the initial heating strategy, but it is not the final perfect strategy, which needs to be optimized afterwards.

[0071] Step S4, according to the power generation demand side requirement and the power supply capacity improvement rate side requirement, the initial heating strategy is evaluated on the power generation side, and according to the unit time heat supply capacity side requirement, the initial heating strategy is evaluated on the heat supply side.

[0072] It can be understood that part of the steam of the power supply system is used for power supply, and the other part is used for grid heating, so the present application analyzes from the power generation side and the unit time heat supply capacity side.

[0073] Step S401, the method for evaluating the initial heating strategy on the power generation side includes determining the steam amount into the low-pressure cylinder of the unit according to the initial heating strategy.

[0074] According to the power generation demand side requirement, the steam amount into the low-pressure cylinder of the unit is configured with a power generation demand side evaluation conversion coefficient to obtain the power generation demand side evaluation.

[0075] According to the power supply capacity improvement rate side requirement, the first steam difference amount into the low-pressure cylinder of the unit is configured with a power supply capacity improvement rate side evaluation conversion coefficient to obtain the power supply capacity improvement rate side evaluation, wherein the first steam difference amount is the difference between the steam amount into the low-pressure cylinder of the unit and the steam amount corresponding to the highest power supply capacity improvement rate of the low-pressure cylinder of the unit.

[0076] According to the power generation demand side evaluation and the power supply rate side evaluation, the power generation side evaluation of the initial heat supply strategy is determined.

[0077] In the power generation side evaluation of the initial heat supply strategy, the expression is included, and the expression for calculating the power generation side evaluation of the initial heat supply strategy is: .

[0078] Among them, is the corresponding value of the power generation side evaluation of the initial heat supply strategy at the t time node, is the power generation demand side conversion coefficient at the t time node, is the steam amount into the low-pressure cylinder of the unit at the t time node, is the power supply rate side evaluation conversion coefficient at the t time node, is the steam amount corresponding to the highest power supply rate of the unit low-pressure cylinder.

[0079] Step S402, the method for heat supply side evaluation of the initial heat supply strategy includes:

[0080] According to the initial heat supply strategy, the steam amount into the heat supply system of the unit is determined;

[0081] According to the unit time heat supply amount side requirement, the unit time heat supply amount side evaluation conversion coefficient is configured to the second steam average amount into the heat supply system of the unit, and the heat supply side evaluation is obtained, wherein the second steam average amount is the average value of the steam amount entering the heat supply system at different rates within a certain time.

[0082] The expression for calculating the heat supply side evaluation of the initial heat supply strategy is: .

[0083] Among them is the corresponding value of the heat supply side evaluation of the initial heat supply strategy at the t time node, is the heat supply demand side conversion coefficient at the t time node, is the steam amount for external heat supply.

[0084] Step S403, according to the power generation side evaluation and the heat supply side evaluation, the initial heat supply strategy is adjusted to generate an optimized heat supply strategy.

[0085] The corresponding value of the power generation side evaluation of the initial heat supply strategy is compared with the standard power generation side evaluation comparison table under the same condition.

[0086] If the evaluation value of the initial heat supply strategy is less than the standard power generation side evaluation value, the initial heat supply strategy is optimized to obtain a secondary heat supply strategy.

[0087] If the secondary power generation side weight value obtained by analyzing the secondary optimization strategy is still lower than the standard power generation side weight value, the secondary heat supply strategy is optimized again to obtain a third heat supply strategy.

[0088] If the third power generation side weight value obtained by analyzing the third optimization strategy still cannot reach the standard power generation side weight value, optimization is performed again.

[0089] The optimization process is set to N times, until the N+1 heat supply strategy is obtained, and the N+1 heat supply side weight value obtained by analyzing the N+1 heat supply strategy is greater than or equal to the standard heat supply side weight value.

[0090] It can be understood that the optimization process is not limited to one time, in order to achieve a more perfect operation, the heat supply strategy will be optimized multiple times, but there is also a time limit, if the optimization time reaches the upper limit, the optimization stops, and the last group is selected for operation.

[0091] A standard heat supply side weight evaluation comparison table is preset, and the standard heat supply side weight evaluation table contains a plurality of standard heat supply side weight evaluation values under different conditions.

[0092] The heat supply side weight evaluation corresponding value of the initial heat supply strategy is compared with the standard heat supply side weight evaluation comparison table under the same condition.

[0093] If the evaluation value of the initial heat supply strategy is less than the standard heat supply side weight evaluation value, the initial heat supply strategy is optimized to obtain a secondary heat supply strategy.

[0094] If the secondary heat supply side weight value obtained by analyzing the secondary optimization strategy is still lower than the standard heat supply side weight evaluation value, the secondary heat supply strategy is optimized again to obtain a third heat supply strategy.

[0095] If the third heat supply side weight value obtained by analyzing the third optimization strategy still cannot reach the standard heat supply side weight value, optimization is performed again.

[0096] The optimization process is set to N times, until the N+1 heat supply strategy is obtained, and the N+1 heat supply side weight value obtained by analyzing the N+1 heat supply strategy is greater than or equal to the standard heat supply side weight value.

[0097] In this embodiment, in order to achieve final optimization, a heat supply strategy optimization method is provided, which comprises tracing a reference model of a past heat supply strategy corresponding to an initial heat supply strategy.

[0098] The past power generation demand curve, the past power supply amount improvement rate curve and the past unit time heat supply amount curve involved in the past heat supply strategy are determined.

[0099] The nearby curve segment corresponding to the past power generation demand curve, the past power supply capacity increasing rate curve and the past unit time heat supply amount curve is determined as the optimized power generation demand curve, the power supply capacity increasing rate curve and the unit time heat supply amount curve.

[0100] The optimized power generation demand curve, the power supply capacity increasing rate curve and the unit time heat supply amount curve are matched with the vertical scanning line, the position of the vertical scanning line is determined according to the current comparison factor, the optimized power generation demand reference point, the power supply increasing rate reference point and the unit time heat supply amount reference point are obtained, and the optimized heat supply strategy is generated by combination.

[0101] It can be understood that the current comparison factor can be changed or adjusted according to actual conditions.

[0102] According to the final optimized heat supply strategy, the unit drives the low-pressure cylinder to supply heat to the outside.

[0103] Corresponding to as Figure 2 shown, the application also provides a unit heat supply system based on low-pressure cylinder zero output, the system comprises: an acquisition module, acquiring the operation log of the low-pressure cylinder of the unit, and analyzing the operation log of the low-pressure cylinder of the unit, determining the past power generation demand, the past power supply capacity increasing rate and the past unit time heat supply amount of the low-pressure cylinder of the unit.

[0104] A construction module is configured to establish a first time reference line for the past power generation demand, the past power supply capacity increasing rate and the past unit time heat supply amount of the low-pressure cylinder of the unit, and establish the past power generation demand curve, the past power supply capacity increasing rate curve and the past unit time heat supply amount curve with the first time reference line as a horizontal variable. The past power generation demand curve, the past power supply capacity increasing rate curve and the past unit time heat supply amount curve are aligned to construct a past heat supply strategy reference model.

[0105] A generation module is configured to generate an initial heat supply strategy in the past heat supply strategy reference model according to the current power generation demand.

[0106] An optimization module is configured to perform power generation emphasis evaluation on the initial heat supply strategy according to power generation demand side emphasis requirements and power supply capacity increasing rate side emphasis requirements, perform heat supply emphasis evaluation on the initial heat supply strategy according to unit time heat supply amount side emphasis requirements, adjust the initial heat supply strategy according to the power generation emphasis evaluation and the heat supply emphasis evaluation, and generate the heat supply strategy again.

[0107] The application discloses a method and system for supplying heat to the outside based on the low-pressure cylinder of a unit, which has the following advantages relative to the work of supplying heat to the low-pressure cylinder of a power plant:

[0108] 1. The application is provided with a heat supply strategy reference model, which can intuitively and stereoscopically simulate operation, so as to quickly and accurately judge social demand.

[0109] 2. The application is provided with system optimization measures, and the reference model is optimized several times, so as to better meet the social demand and provide convenience for the industrial heat load in the heating season.

[0110] Finally, it should be noted that the above examples are only used to illustrate the technical solutions of the present application and not to limit them. Although the present application has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present application can still be modified or replaced by equivalents, and these modifications or equivalent replacements should not make the modified technical solutions deviate from the spirit and scope of the technical solutions of the present application.

Claims

1. A method for supplying heat to the outside based on a low-pressure cylinder of a unit, characterized by, The method comprises the following steps: acquiring a unit low-pressure cylinder operation log and analyzing the unit low-pressure cylinder operation log to determine past power generation demand, past power supply capacity increase rate and past unit time heat supply capacity of the unit low-pressure cylinder; establishing a first time reference line based on the past power generation demand, the past power supply capacity increase rate and the past unit time heat supply capacity of the unit low-pressure cylinder, and taking the first time reference line as a horizontal variable to respectively establish a past power generation demand curve, a past power supply capacity increase rate curve and a past unit time heat supply capacity curve; aligning the past power generation demand curve, the past power supply capacity increase rate curve and the past unit time heat supply capacity curve to construct a past heat supply strategy reference model; determining an initial heat supply strategy in the past heat supply strategy reference model according to a current comparison factor; performing power generation emphasis evaluation on the initial heat supply strategy according to power generation demand side emphasis requirements and power supply capacity increase rate side emphasis requirements, and performing heat supply emphasis evaluation on the initial heat supply strategy according to unit time heat supply capacity side emphasis requirements; adjusting the initial heat supply strategy according to the power generation emphasis evaluation and the heat supply emphasis evaluation to generate an optimized heat supply strategy; driving the unit low-pressure cylinder to supply heat to the outside according to the optimized heat supply strategy; the method for performing power generation emphasis evaluation on the initial heat supply strategy comprises the following steps: determining steam quantity input into the unit low-pressure cylinder according to the initial heat supply strategy; configuring a power generation demand side emphasis evaluation conversion coefficient for the steam quantity input into the unit low-pressure cylinder according to power generation demand side emphasis requirements to obtain power generation demand side emphasis evaluation; configuring a power supply capacity increase rate side emphasis evaluation conversion coefficient for a first steam difference quantity input into the unit low-pressure cylinder according to power supply capacity increase rate side emphasis requirements to obtain power supply capacity increase rate side emphasis evaluation, wherein the first steam difference quantity is a difference between the steam quantity input into the unit low-pressure cylinder and steam quantity corresponding to the highest power supply capacity increase rate of the unit low-pressure cylinder; determining power generation emphasis evaluation of the initial heat supply strategy according to the power generation demand side emphasis evaluation and the power supply capacity increase rate side emphasis evaluation; the expression for calculating the power generation emphasis evaluation of the initial heat supply strategy is: ； wherein, a generating-side weight evaluation corresponding value of an initial heat supply strategy at a tth time node, a generating-demand-side weight conversion coefficient at the tth time node, a steam amount into a low-pressure cylinder of a unit at the tth time node, a generating-capacity-increase-rate-side weight evaluation conversion coefficient at the tth time node, a steam amount corresponding to a highest generating-capacity-increase rate of the unit low-pressure cylinder. the method for performing heat supply emphasis evaluation on the initial heat supply strategy comprises the following steps: determining steam quantity input into a heat supply system of the unit according to the initial heat supply strategy; configuring a unit time heat supply capacity side emphasis evaluation conversion coefficient for a second steam average quantity input into the heat supply system of the unit according to unit time heat supply capacity side emphasis requirements to obtain heat supply side emphasis evaluation, wherein the second steam average quantity is an average value of steam quantity input into the heat supply system at different rates within a certain time; the expression for calculating the heat supply side emphasis evaluation of the initial heat supply strategy is: wherein is the heating supply side emphasis evaluation corresponding value of the initial heating supply strategy of the t time node, is the heating demand side emphasis conversion coefficient of the t time node, is the steam amount of external heating supply.

2. The method for supplying heat to the outside based on the low-pressure cylinder of a unit according to claim 1, characterized by, the method for constructing the past heat supply strategy reference model comprises the following steps: establishing a vertical scanning line for the past power generation demand curve, the past power supply capacity increase rate curve and the past unit time heat supply capacity curve, and taking intersection points of the vertical scanning line and the past power generation demand curve, the past power supply capacity increase rate curve and the past unit time heat supply capacity curve as a power generation demand first reference point, a power supply capacity increase rate first reference point and a unit time heat supply capacity first reference point, respectively; According to the comparison factors at the moment, the position of the vertical scanning line is determined, and the determined power generation demand first reference point, power supply rate first reference point and unit time heat supply first reference point are combined to generate an initial heat supply strategy.

3. The method for supplying heat to the outside based on the low-pressure cylinder of a unit according to claim 1, characterized by, There is a standard power generation side emphasis evaluation comparison table, which contains several standard power generation side emphasis evaluation values under different conditions; The power generation side emphasis evaluation corresponding value of the initial heat supply strategy is compared with the standard power generation side emphasis evaluation comparison table under the same condition; If the evaluation value of the initial heat supply strategy is less than the standard power generation side emphasis evaluation value, the initial heat supply strategy is optimized to obtain a secondary heat supply strategy; If the secondary power generation side emphasis value obtained by analyzing the secondary optimization strategy is still lower than the standard power generation side emphasis evaluation value, the secondary heat supply strategy is optimized again to obtain a tertiary heat supply strategy; If the tertiary power generation side emphasis value obtained by analyzing the tertiary optimization strategy still cannot reach the standard power generation side emphasis value, optimization is performed again. The optimization process is set to N times, until the N+1 heat supply strategy is obtained, and the N+1 power generation side emphasis value obtained by analyzing the N+1 heat supply strategy is greater than or equal to the standard power generation side emphasis value.

4. The method for supplying heat to the outside based on the low-pressure cylinder of a unit according to claim 1, characterized by, There is a standard heat supply side emphasis evaluation comparison table, which contains several standard heat supply side emphasis evaluation values under different conditions; The heat supply side emphasis evaluation corresponding value of the initial heat supply strategy is compared with the standard heat supply side emphasis evaluation comparison table under the same condition; If the evaluation value of the initial heat supply strategy is less than the standard heat supply side emphasis evaluation value, the initial heat supply strategy is optimized to obtain a secondary heat supply strategy; If the secondary heat supply side emphasis value obtained by analyzing the secondary optimization strategy is still lower than the standard heat supply side emphasis evaluation value, the secondary heat supply strategy is optimized again to obtain a tertiary heat supply strategy; If the tertiary heat supply side emphasis value obtained by analyzing the tertiary optimization strategy still cannot reach the standard heat supply side emphasis value, optimization is performed again. The optimization process is set to N times, until the N+1 heat supply strategy is obtained, and the N+1 heat supply side emphasis value obtained by analyzing the N+1 heat supply strategy is greater than or equal to the standard heat supply side emphasis value.

5. The method of claim 1, wherein the method is based on zero output of the low-pressure cylinder. The heat supply strategy optimization method comprises: Tracing the reference model of the past heat supply strategy corresponding to the initial heat supply strategy; Determining the past power generation demand curve, past power supply rate curve and past unit time heat supply curve involved in the past heat supply strategy; The nearby curve segments corresponding to the optimized power generation demand curve, power supply rate curve and unit time heat supply curve are identified; The optimized power generation demand curve, power supply rate curve and unit time heat supply curve are matched with the vertical scanning line, the position of the vertical scanning line is determined according to the comparison factors at the moment, the optimized power generation demand reference point, power supply rate reference point and unit time heat supply reference point are obtained, and thus an optimized heat supply strategy is generated.

6. A unit heating system based on zero output of low-pressure cylinder, applied to the unit heating method based on zero output of low-pressure cylinder as claimed in claim 3, characterized in that, It comprises: The acquisition module acquires the operation log of the low-pressure cylinder of the unit and analyzes the operation log of the low-pressure cylinder of the unit to determine the past power generation demand, the past power supply capacity increase rate and the past unit time heat supply capacity of the low-pressure cylinder of the unit; The construction module establishes a first time reference line for the past power generation demand, the past power supply capacity increase rate and the past unit time heat supply capacity of the low-pressure cylinder of the unit, and establishes a past power generation demand curve, a past power supply capacity increase rate curve and a past unit time heat supply capacity curve with the first time reference line as a horizontal variable, aligns the past power generation demand curve, the past power supply capacity increase rate curve and the past unit time heat supply capacity curve, and constructs a past heat supply strategy reference model; The generation module generates an initial heat supply strategy in the past heat supply strategy reference model according to the current power generation demand; The optimization module performs power generation emphasis evaluation on the initial heat supply strategy according to the power generation demand side emphasis requirement and the power supply capacity increase rate side emphasis requirement, performs heat supply emphasis evaluation on the initial heat supply strategy according to the unit time heat supply capacity side emphasis requirement, adjusts the initial heat supply strategy according to the power generation emphasis evaluation and the heat supply emphasis evaluation, and generates an optimized heat supply strategy.

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