High and medium parameter coordinated heat supply energy-saving optimization adjustment method for large thermal power generating unit

Abstract

The invention discloses a high and medium parameter coordinated heat supply energy-saving optimization adjustment method for a large thermal power generating unit, and belongs to the technical field of thermoelectric distribution. The method comprises the following steps: introducing a # imgabs0 # loss rate, directly comparing unit economy and energy utilization degrees under different units, different steam extraction openings and the same heat supply parameter by utilizing a # imgabs1 # loss rate so as to determine the distribution priority of the heat load, and performing distribution of the electric load by utilizing the capacity of influencing the unit economy by the electric load, thereby realizing multi-unit energy-saving optimization adjustment. According to the method, by calculating the influence capacity of the heat load and the electric load on the heat consumption rate of the unit under the condition that a single steam extraction opening supplies heat, the energy-saving optimization adjustment method can be achieved under the condition that multiple units, multiple modes and units limited by historical operation data are achieved, and the purpose of improving the economical efficiency of the whole field is achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of heat and power distribution, and in particular relates to a method for optimizing and regulating high and medium parameters of coordinated heating and energy saving of a large thermal power unit. Background Art

[0002] With the large-scale power generation and grid connection of renewable energy sources with strong time-varying characteristics such as wind and light, and the continuous advancement of my country's industrialization and urbanization, centralized technologies such as industrial steam and residential heating have been widely used in recent years. From the perspective of the process of heat source-heat network-user, the heat source is a typical configuration of multiple units and multiple heating modes, and there is no independent power generation load and heating load adjustment authority. Therefore, in-depth exploration of the energy-saving potential of cogeneration units is of great significance to reducing the cost of cogeneration.

[0003] Traditional thermal power load distribution relies on the experience of technicians to adjust the load, which has obvious defects; there are few thermal power load distribution methods for multiple units and multiple parameters; currently, many thermal power load distribution methods for cogeneration units have been proposed in theory, but due to the huge amount of calculation, most of them involve iterative calculations, all of which need to be calculated in advance or by professional staff, and are difficult to apply on site.

[0004] The rise of operations research, linear programming methods, dynamic optimization and other mathematical methods have brought new ideas to the study of thermal power load distribution. Although the research on thermal power load distribution of cogeneration units has developed rapidly, most of the research, both domestic and foreign, still tends to study models and algorithms, and is mainly theoretical. The research objects are mostly units that only use steam extraction for heating. The models are relatively idealized and have few practical applications. Different types of heating units have different characteristic curves, and the relationship between the economic efficiency of the unit and the thermal load and electrical load is also different. For general heating units, it is generally believed that the higher the electrical load and the higher the thermal load, the more economical and the lower the coal consumption. However, not all units conform to this law. There are also simulated annealing algorithms, genetic algorithms, and particle swarm algorithms that rely on computer technology for thermal power distribution, but they require a large amount of operating data and cannot provide a good solution for units that are limited by historical operating data. Summary of the invention

[0005] In view of the problems mentioned in the background technology, the present invention proposes a large-scale thermal power unit high and medium parameter coordinated heating energy saving optimization adjustment method, by introducing The loss rate is distributed among multiple units with different parameters according to the steam extraction flow rate and steam supply quality, so as to optimize the economy of the whole plant and use energy most reasonably; in the case of multiple units, multiple modes, and units limited by historical operating data, energy-saving optimization and adjustment methods can be implemented to improve the economy of the whole plant.

[0006] Technical solution: In order to solve the above technical problems, the technical solution adopted by the present invention is as follows:

[0007] A method for optimizing the heating and energy saving of large thermal power units with high and medium parameters is introduced. Loss rate, utilization The loss rate is directly compared with the unit economy and energy utilization under different units, different steam extraction ports and the same heating parameters to determine the priority of heat load allocation, and the electric load is used to affect the unit's economic ability to distribute the electric load, thereby achieving energy-saving optimization and regulation of multiple units.

[0008] As a preferred embodiment, the specific implementation steps are:

[0009] S1: Calculate the extraction heat and steam heat

[0010] S2: Based on extraction steam heat and steam heat Calculate steam supply Loss and Loss rate;

[0011] S3: Follow The loss rate determines the priority of high and medium parameters for heating, and performs the initial distribution of heat load;

[0012] S4: Obtain historical operation or simulation data of the unit and use the ability of electric load to affect the economic performance of the unit to distribute the electric load;

[0013] S5: Finally, fine-tune the distribution of thermal power load according to the thermal power feasible domain and the priority of steam extraction heating.

[0014] As a preferred method, in S1, the extraction heat is calculated and steam heat The specific content is:

[0015] When the unit supplies steam to the outside, the supply pressure a=(gMPa, zMPa); the steam extraction port is represented by i=(1, 2, 3, 4, ...); the flow rate D of the steam extraction port i under the steam supply pressure a i，a , the total steam flow rate under the steam supply pressure is D a ;

[0016] The total extraction steam flow rate of g MPa is expressed as:

[0017]

[0018] The total extraction steam flow rate for zMPa is expressed as:

[0019]

[0020] The total steam supply flow D is expressed as:

[0021] D=D g +D z ,

[0022] Among them, D i，g It indicates the flow rate of the steam extraction port i under the steam supply pressure gMPa; D i，z It indicates the flow rate of the steam extraction port i under the steam supply pressure zMPa;

[0023] Extraction heat The calculation formula is as follows:

[0024] E Qch =D h [h h -h m -T m (s ch -s m )],

[0025] Steam heat The calculation formula is as follows:

[0026] E Qgh =D h [h h -h m -T m (s gh -s m )],

[0027] Among them, E Qch Indicates the extraction heat E Qgh Indicates the steam heat h m represents the enthalpy of water under ambient conditions; T m Indicates the ambient temperature; s ch Indicates the entropy value of heating steam; s gh Indicates the entropy value of heating steam; s m Indicates the entropy value of water under environmental conditions; D h Indicates the extraction steam flow rate, h h Indicates the extraction enthalpy.

[0028] As a preference, in S2, based on the extraction steam heat and steam heat Calculate steam supply Loss and The specific contents of the loss rate are:

[0029] Heat The loss calculation formula is as follows:

[0030] EL =E Qch -E Qgh ,

[0031] Among them, E L Indicates steam supply pressure matching damage;

[0032] definition Loss rate

[0033]

[0034] C a It represents the optimal steam extraction port for steam with a parameter of a MPa, η EL，i，a It means that the steam supplied by the i-th extraction port is aMPa. The relationship between the two is expressed as:

[0035] C a =min{η EL，i，a},

[0036] The total heat rate NHR of a thermal power plant with n units t It is expressed as:

[0037]

[0038] Among them, NHR j represents the heat rate of the jth unit;

[0039] Standard coal consumption rate for power generation of the whole plant B et It is expressed as:

[0040]

[0041] Among them, B j represents the standard coal consumption rate of the jth unit, B e represents the standard coal consumption for power generation, P e Indicates the generating power of the unit;

[0042] The jth unit generates electricity E Pe It is expressed as:

[0043] E Pe =P e ,

[0044] Among them, E Pe Indicates power generation P e Indicates the generating power of the unit;

[0045] Whole plant Efficiency η ext It is expressed as:

[0046]

[0047] Among them, E f Indicates fuel chemistry E Pe Indicates power generation E Qgh Indicates the steam heat η exj The jth unit efficiency.

[0048] Preferably, in S3, according to The loss rate determines the priority of high and medium parameters for heating, and the specific contents of the initial distribution of heat load are as follows:

[0049] S31: Build the thermal-electric coupled thermal system model of the unit and couple it with the data processing software;

[0050] S32: Determine the heating priority of high and medium parameters;

[0051] S33: Allocate heat load according to the heating priorities of high and medium parameters. If the heat load of the steam extraction port with a higher heating priority is full, allocate the remaining heat load to the steam extraction port corresponding to the lower heating priority.

[0052] As a preferred embodiment, in S31, the specific contents of building the thermoelectric coupling thermal system model of the unit and coupling it with the data processing software are as follows:

[0053] EBSILON is used to build the thermoelectric coupling thermal system model of the unit. By writing a communication program with EBSILON in MATLAB, EBSILON automatically performs simulation, and the thermal data obtained by EBSILON simulation is fed back to MATLAB for processing.

[0054] Preferably, in S32, the specific content of determining the heating priority of high and medium parameters is:

[0055] Input the power load of the whole plant, high and medium heating parameters and heating flow rate into the host computer; the system distributes the power load equally to each unit, and each unit selects a heating flow rate within the heating capacity range under the evenly distributed power load. The system simulates the thermal parameters of each heating extraction port when steam is supplied separately through simulation software, and calculates the corresponding heat flow rate of each extraction port. loss rate, the corresponding steam extraction ports for high-parameter steam Loss rate, sorted from small to large, corresponds to The steam extraction port with the smallest loss rate value has the best priority in supplying high-parameter steam. After the high-parameter heating priority is determined, the medium-parameter heating adopts the same steps to determine the heating priority.

[0056] Preferably, in S4, the specific contents of obtaining historical operation or simulation data of the unit and using the ability of the electric load to affect the economic performance of the unit to distribute the electric load are:

[0057] The distribution of electrical load is recorded as A condition; for the historical operation data or simulation data of the unit, the heat rate of the unit when the i-th steam extraction port is used for steam extraction is described as P e With D i The relationship between the heat rate, electrical load and extraction flow rate when the unit uses the i-th extraction port to supply steam is expressed as:

[0058] NHR(P e ,D i ),

[0059] Its e , D i ) Click on P e , D i The first-order partial derivatives of are recorded as:

[0060] The second-order partial derivatives are recorded as:

[0061] It reflects the influence of the electrical load on the heat consumption rate of the unit when the unit changes the electrical load under certain working conditions. It reflects the influence of heat load on the heat rate of the unit when the unit changes heat load under certain working conditions; It reflects P e , D i The changing trend of the ability to influence heat rate;

[0062] Calculate the corresponding steam extraction port of each unit under condition A. like When The smallest unit electrical load is transferred to the On the largest unit, transfer once and calculate data once until one side is fully loaded or The smallest unit with The largest unit Equal or one side If a unit fails during the process of transferring the electric load or at the beginning of the transfer In the case of the above, the unit is marked as #1, and part of the electrical load of #1 is transferred to Except #1 On the largest unit, until #1 Or receive the full load of the electric load unit or receive the full load of the electric load unit until.

[0063] As a preferred embodiment, in S5, the specific content of fine-tuning the distribution of thermal power load according to the thermal power feasible region and the steam extraction heating priority is as follows:

[0064] During the process of electric load distribution, if the heat load of a unit exceeds the feasible range of thermal power, the excess part will be transferred to other units according to the priority of heat load distribution. After the heat load is transferred, if the heat consumption rate of the whole plant is the same as before, there is no need to adjust the electric load; if the heat consumption rate of the whole plant increases, the electric load of the unit receiving the heat load will be transferred to The unit that will receive the electrical load Greater than the receiving heat load unit Each time the transfer is performed, it is necessary to determine whether the above conditions are met. If not, the transfer of the electrical load is terminated; the iteration is continued until the difference in heat rate between the current optimization and the previous optimization is less than the given optimization accuracy.

[0065] Beneficial effects: Compared with the prior art, the present invention has the following advantages:

[0066] (1) The present invention defines The loss rate can reflect the energy utilization of steam supply; the present invention utilizes The loss rate can be directly compared with the unit economy and energy utilization under different units, different steam extraction ports and the same heating parameters to determine the priority of heat load allocation.

[0067] (2) Compared with the single-extraction unit, the historical data required for the thermal and electric load distribution of the multi-extraction unit of the present invention is greatly increased. By calculating the influence of the thermal load and the electric load on the heat consumption rate of the unit under the condition of heating by a single steam extraction port, a method for energy-saving optimization and adjustment can be implemented in the case of multiple units, multiple modes, and units limited by historical operating data, thereby achieving the purpose of improving the economy of the entire site. BRIEF DESCRIPTION OF THE DRAWINGS

[0068] Figure 1 It is a schematic diagram of the overall process of the present invention;

[0069] Figure 2 This is the whole plant of 3400MW-520t / h thermal power load distribution of the present invention Calculation results of efficiency and plant heat rate;

[0070] Figure 3 The invention is a 3400MW-520t / h thermal power load distribution system for the whole plant Calculation results of efficiency and standard coal consumption rate for power generation. DETAILED DESCRIPTION

[0071] The present invention is further illustrated below in conjunction with specific examples. The examples are implemented based on the technical solutions of the present invention. It should be understood that these examples are only used to illustrate the present invention and are not used to limit the scope of the present invention.

[0072] The large-scale thermal power unit high and medium parameter coordinated heating energy saving optimization adjustment method provided in this embodiment introduces Loss rate, according to The heat loss rate determines the priority of high and medium parameters, thereby allocating the heat load for the first time, and then using the electric load to affect the economic ability of the unit to allocate the electric load, and finally fine-tuning the distribution of heat load according to the feasible region of thermal power and the priority of steam extraction heating. Including the representation of each parameter, the extraction heat and steam heat Calculation and definition of loss rate, determination of extraction steam heating priority, heat load distribution method, data acquisition, and electrical load distribution method.

[0073] The specific implementation steps are as follows:

[0074] S1: Calculate the extraction heat and steam heat Specifically:

[0075] When the unit supplies steam to the outside, the supply pressure a=(gMPa, zMPa); the steam extraction port is represented by i=(1, 2, 3, 4, ...); the flow rate D of the steam extraction port i under the steam supply pressure a i，a , the total steam flow rate under the steam supply pressure is D a .

[0076] The total extraction steam flow rate for gMPa can be expressed as:

[0077]

[0078] The total extraction steam flow rate for zMPa can be expressed as:

[0079]

[0080] The total steam supply flow D can be expressed as:

[0081] D=D g +D z ,

[0082] Among them, D i，g It indicates the flow rate of the steam extraction port i under the steam supply pressure gMPa; D i，z It represents the flow rate of the steam extraction port i under the steam supply pressure zMPa.

[0083] Extraction heat The calculation formula is as follows:

[0084] E Qch =D h [h h -h m -T m (s ch -s m )],

[0085] Steam heat The calculation formula is as follows:

[0086] E Qgh =D h [h h -h m -T m (s gh -s m )],

[0087] Among them, E Qch Indicates the extraction heat E Qgh Indicates the steam heat h m Indicates the enthalpy of water under ambient conditions / kJ·kg -1 ; T m Indicates ambient temperature / K; S ch Indicates the entropy value of heating steam / kJ·(kg·K) -1 ; S gh Indicates the entropy value of heating steam / kJ·(kg·K) -1 ;s m Indicates the entropy value of water under ambient conditions / kJ·(kg·K) -1 ;D h Indicates the extraction steam flow rate; h h Indicates the extraction enthalpy.

[0088] S2: Based on extraction steam heat and steam heat Calculate steam supply Loss and Loss rate;

[0089] Heat The loss calculation formula is as follows:

[0090] E L =E Qch -E Qgh ,

[0091] Among them, E L Indicates steam supply pressure matching Loss / kw.

[0092] When the external conditions are the same, for two units with different parameters, the steam extraction flow and steam supply quality are combined and utilized between the two different units. The energy loss rate is allocated to achieve the best economy and the most reasonable energy use for the whole plant.

[0093] definition Loss rate

[0094]

[0095] C a It represents the optimal steam extraction port for steam with a parameter of a MPa, η EL，i，a It means that the steam supplied by the i-th extraction port is aMPa. The relationship between the two is expressed as:

[0096] C a =min{η EL，i，a},

[0097] The total heat rate NHR of a thermal power plant with n units t It is expressed as:

[0098]

[0099] Among them, NHR j Represents the heat rate of the jth unit.

[0100] Standard coal consumption rate for power generation of the whole plant B et It is expressed as:

[0101]

[0102] Among them, B j Indicates the standard coal consumption rate of the jth unit for power generation / g·(kW·h) -1 , Be represents the standard coal consumption for power generation / kg·s -1 , P e Indicates the unit's generating power / kW.

[0103] The jth unit generates electricity E Pe It is expressed as:

[0104] E Pe =P e ,

[0105] Among them, E Pe Indicates power generation P e Indicates the unit's generating power / kW.

[0106] Whole plant Efficiency ηext It is expressed as:

[0107]

[0108] Among them, E f Indicates fuel chemistry E Pe Indicates power generation E Qgh Indicates the steam heat η exj The jth unit efficiency.

[0109] The loss rate decreases with the increase of extraction steam flow rate. The smaller it is, the better the steam quality becomes; in general The change range of the loss rate is very small, and its change can only be obvious when the extraction steam flow rate is relatively large.

[0110] S3: Follow The loss rate determines the priority of high and medium parameters for heating, and performs the initial distribution of heat load;

[0111] S31: Build the thermal-electric coupled thermal system model of the unit and couple it with the data processing software;

[0112] EBSILON (EBSILON Professional) was used to build the thermoelectric coupling thermal system model of the unit. By writing a communication program with EBSILON in MATLAB, EBSILON was enabled to perform automatic simulation, and the thermal data obtained by EBSILON simulation was fed back to MATLAB for processing.

[0113] S32: Determine the heating priority of high and medium parameters;

[0114] Input the power load of the whole plant, high and medium heating parameters and heating flow rate into the host computer. The system distributes the power load equally to each unit, and each unit selects a heating flow rate within the heating capacity range under the evenly distributed power load. The system simulates the thermal parameters of each heating steam extraction port when it supplies steam independently through simulation software, and calculates the corresponding heat flow rate of each steam extraction port. loss rate, the corresponding steam extraction ports for high-parameter steam Loss rate, sorted from small to large, corresponds to The extraction port with the smallest loss rate has the best priority for supplying high-parameter steam, that is, find C a After the heating priority of high parameters is determined, the heating priority of medium parameters is determined by the same steps.

[0115] S33: Allocate heat load according to the heating priorities of high and medium parameters. If the heat load of the steam extraction port with a higher heating priority is full, allocate the remaining heat load to the steam extraction port corresponding to the lower heating priority.

[0116] S4: Obtain historical operation or simulation data of the unit and use the ability of electric load to affect the economic performance of the unit to distribute the electric load;

[0117] After the heat load distribution is completed, the electrical load distribution needs to be carried out, which is recorded as condition A. This part requires the historical operation data of the unit, or simulation data for optimization calculation. The amount of data required by this method is much smaller than that of the traditional method.

[0118] For the historical operation data or simulation data of the unit, the heat rate of the unit when using the i-th extraction port to extract steam is described as P e With D i The heat rate (NHR) and electrical load (P e )、Extraction steam flow(D i ) can be expressed as:

[0119] NHR(P e ,D i ),

[0120] Its e , D i ) Click on P e , D i The first-order partial derivatives of are recorded as: The second-order partial derivatives are recorded as:

[0121] It reflects the influence of the electrical load on the heat consumption rate of the unit when the unit changes the electrical load under certain working conditions. It reflects the influence of heat load on the heat rate of the unit when the unit changes heat load under certain working conditions. It reflects P e , D i The changing trend of the ability to influence heat rate.

[0122] Calculate the corresponding steam extraction port of each unit under condition A. like When The smallest unit electrical load is transferred to the On the largest unit, transfer once and calculate data once until one side is fully loaded or The smallest unit with The largest unit Equal or one side If a unit fails during the process of transferring the electric load or at the beginning of the transfer In the case of the above, the unit is marked as #1, and part of the electrical load of #1 is transferred to Except #1 On the largest unit, until #1 Or receiving the full load of the load unit or until.

[0123] S5: Finally, fine-tune the distribution of thermal power load according to the thermal power feasible domain and the priority of steam extraction heating.

[0124] During the process of electric load distribution, if the heat load of a unit exceeds the feasible range of thermal power, the excess part will be transferred to other units according to the priority of heat load distribution. After the heat load is transferred, if the heat consumption rate of the whole plant is the same as before, there is no need to adjust the electric load; if the heat consumption rate of the whole plant increases, the electric load of the unit receiving the heat load will be transferred to The unit that will receive the electrical load Greater than the receiving heat load unit Each time the load is transferred, it is necessary to determine whether the above conditions are met. If not, the load transfer is terminated. The iteration is continued until the difference between the heat rate of the current optimization and the previous optimization is less than the given Δ, where Δ represents the accuracy of the optimization and a value needs to be given according to actual needs.

[0125] Finally, the optimized thermal power load, heat consumption rate, Parameters such as efficiency are displayed on the host computer.

[0126] Taking two 1000MW supercritical units and two 1000MW ultra-supercritical units in a power plant as an example, the thermal power load distribution is optimized by taking the thermal power load conditions of 3400MW-520t / h and 2400MW-520t / h as examples. Seven thermal power distribution schemes are analyzed and compared, as shown in Table 1 below:

[0127] Table 1 3400MW-520t / h thermal power load distribution plan

[0128]

[0129] The 3400MW-520t / h thermal power load scheme is shown in Table 1, among which Scheme 7 is the scheme obtained by adopting the thermal power allocation strategy. Figure 2 , 3 The calculation results are shown in Figure 2. Among them, the result of scheme 7 is the best, and the result of scheme 2 is the worst. In terms of efficiency, Scheme 7 is 0.053% higher than Scheme 2. In terms of heat consumption rate, Scheme 7 is 39.33kg / kw·h lower than Scheme 2. In terms of coal consumption rate, Scheme 7 is 2.063g / kw·h lower than Scheme 2.

[0130] The historical data required for thermal and electric load distribution of the multi-extraction units of the present invention is greatly increased. By calculating the influence of thermal load and electric load on the heat consumption rate of the unit under the condition of heating by a single extraction port, a method for energy-saving optimization and adjustment can be implemented in the case of multiple units, multiple modes, and units limited by historical operating data, thereby achieving the purpose of improving the economy of the entire site.

[0131] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for optimizing and regulating high and medium parameters of large thermal power units for coordinated heating and energy saving, characterized in that: By introducing Loss rate, utilization The loss rate is directly compared with the unit economy and energy utilization under different units, different steam extraction ports and the same heating parameters to determine the priority of heat load allocation, and the electric load is used to affect the unit's economic ability to distribute the electric load, thereby achieving energy-saving optimization and regulation of multiple units.

2. The method for optimizing and regulating high and medium parameters of large thermal power units for coordinated heating and energy saving according to claim 1 is characterized in that: The specific implementation steps are: S1: Calculate the extraction heat and steam heat S2: Based on extraction steam heat and steam heat Calculate steam supply Loss and Loss rate; S3: Follow The loss rate determines the priority of high and medium parameters for heating, and performs the initial distribution of heat load; S4: Obtain historical operation or simulation data of the unit and use the ability of electric load to affect the economic performance of the unit to distribute the electric load; S5: Finally, fine-tune the distribution of thermal power load according to the thermal power feasible domain and the priority of steam extraction heating.

3. The method for optimizing and adjusting high and medium parameters of large thermal power units for coordinated heating and energy saving according to claim 2 is characterized in that: In S1, calculate the extraction heat and steam heat The specific content is: When the unit supplies steam to the outside, the supply pressure a=(gMPa, zMPa); the steam extraction port is represented by i=(1, 2, 3, 4, ...); the flow rate D of the steam extraction port i under the steam supply pressure a i，a , the total steam flow rate under the steam supply pressure is D a ; The total extraction steam flow rate for gMPa is expressed as: The total extraction steam flow rate for zMPa is expressed as: The total steam supply flow D is expressed as: D=D g +D z , Among them, D i，g It indicates the flow rate of the steam extraction port i under the steam supply pressure gMPa; D i，z It indicates the flow rate of the steam extraction port i under the steam supply pressure zMPa; Extraction heat The calculation formula is as follows: E Qch =D h [h h -h m -T m (s ch -s m )], Steam heat The calculation formula is as follows: E Qgh =D h [h h -h m -T m (s gh -s m )], Among them, E Qch Indicates the extraction heat E Qgh Indicates the steam heat h m represents the enthalpy of water under ambient conditions; T m Indicates the ambient temperature; s ch Indicates the entropy value of heating steam; s gh Indicates the entropy value of heating steam; s m Indicates the entropy value of water under environmental conditions; D h Indicates the extraction steam flow rate, h h Indicates the extraction enthalpy.

4. The method for optimizing and regulating high and medium parameters of large thermal power units for coordinated heating and energy saving according to claim 2 is characterized in that: In S2, based on the extraction steam heat and steam heat Calculate steam supply Loss and The specific contents of the loss rate are: Heat The loss calculation formula is as follows: AND L =And Qch -AND Qgh , Among them, E L Indicates steam supply pressure matching damage; definition Loss rate C a It represents the optimal steam extraction port for steam with a parameter of a MPa, η EL，i，a It means that the steam supplied by the i-th extraction port is a MPa. The relationship between the two is expressed as: C a =min{η EL，i，a }, The total heat rate NHR of a thermal power plant with n units t It is expressed as: Among them, NHR j represents the heat rate of the jth unit; Standard coal consumption rate for power generation of the whole plant B et It is expressed as: Among them, B j represents the standard coal consumption rate of the jth unit, B e represents the standard coal consumption for power generation, P e Indicates the generating power of the unit; The jth unit generates electricity E Pe It is expressed as: AND Pe =P e , Among them, E Pe Indicates power generation P e Indicates the generating power of the unit; Whole plant Efficiency η ext It is expressed as: Among them, E f Indicates fuel chemistry E Pe Indicates power generation E Qgh Indicates the steam heat η exj The jth unit efficiency.

5. The method for optimizing and adjusting high and medium parameters of large thermal power units for coordinated heating and energy saving according to claim 2 is characterized in that: In S3, follow The loss rate determines the priority of high and medium parameters for heating, and the specific contents of the initial distribution of heat load are as follows: S31: Build the thermal-electric coupled thermal system model of the unit and couple it with the data processing software; S32: Determine the heating priority of high and medium parameters; S33: Allocate heat load according to the heating priorities of high and medium parameters. If the heat load of the steam extraction port with a higher heating priority is full, allocate the remaining heat load to the steam extraction port corresponding to the lower heating priority.

6. The method for optimizing and regulating high and medium parameters of large thermal power units for coordinated heating and energy saving according to claim 5 is characterized in that: In S31, the thermoelectric coupled thermal system model of the unit is built to couple it with the data processing software. The specific contents are as follows: EBSILON is used to build the thermoelectric coupling thermal system model of the unit. By writing a communication program with EBSILON in MATLAB, EBSILON automatically performs simulation, and the thermal data obtained by EBSILON simulation is fed back to MATLAB for processing.

7. The method for optimizing and regulating high and medium parameters of large thermal power units for coordinated heating and energy saving according to claim 5 is characterized in that: In S32, the specific contents of determining the heating priority of high and medium parameters are: Input the power load of the whole plant, high and medium heating parameters and heating flow rate into the host computer; the system distributes the power load equally to each unit, and each unit selects a heating flow rate within the heating capacity range under the evenly distributed power load. The system simulates the thermal parameters of each heating extraction port when steam is supplied separately through simulation software, and calculates the corresponding heat flow rate of each extraction port. loss rate, the corresponding steam extraction ports for high-parameter steam Loss rate, sorted from small to large, corresponds to The steam extraction port with the smallest loss rate value has the best priority in supplying high-parameter steam. After the high-parameter heating priority is determined, the medium-parameter heating adopts the same steps to determine the heating priority.

8. The method for optimizing and regulating high and medium parameters of large thermal power units for coordinated heating and energy saving according to claim 4 is characterized in that: In S4, the specific contents of obtaining the historical operation or simulation data of the unit and using the electric load to affect the economic performance of the unit to distribute the electric load are as follows: The distribution of electrical load is recorded as A condition; for the historical operation data or simulation data of the unit, the heat rate of the unit when the i-th extraction port is used for steam extraction is described as P e With D i The relationship between the heat rate, electrical load and extraction flow rate when the unit uses the i-th extraction port to supply steam is expressed as: NHR(P e ,D i ), Its e , D i ) Click on P e , D i The first-order partial derivatives of are recorded as: The second-order partial derivatives are recorded as: It reflects the influence of the electrical load on the heat consumption rate of the unit when the unit changes the electrical load under certain working conditions. It reflects the influence of heat load on the heat rate of the unit when the unit changes heat load under certain working conditions; It reflects P e , D i The changing trend of the ability to influence heat rate; Calculate the corresponding steam extraction port of each unit under condition A. like When The smallest unit electrical load is transferred to the On the largest unit, transfer once and calculate data once until one side is fully loaded or The smallest unit with The largest unit Equal or one side until; If a unit fails during the process of transferring the electric load or at the beginning of the transfer In the case of the above, the unit is marked as #1, and part of the electrical load of #1 is transferred to Except #1 On the largest unit, until #1 Or receiving electric load unit with full electric load or receiving electric load unit until.

9. The method for optimizing and regulating high and medium parameters of large thermal power units for coordinated heating and energy saving according to claim 8 is characterized in that: In S5, the specific content of fine-tuning the distribution of thermal power load according to the thermal power feasible region and the steam extraction heating priority is as follows: During the process of electric load distribution, if the heat load of a unit exceeds the feasible range of thermal power, the excess part will be transferred to other units according to the priority of heat load distribution. After the heat load is transferred, if the heat consumption rate of the whole plant is the same as before, there is no need to adjust the electric load; if the heat consumption rate of the whole plant increases, the electric load of the unit receiving the heat load will be transferred to The unit that will receive the electrical load Greater than the receiving heat load unit Each time the transfer is performed, it is necessary to determine whether the above conditions are met. If not, the transfer of the electrical load is terminated; the iteration is continued until the difference in heat rate between the current optimization and the previous optimization is less than the given optimization accuracy.

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