CN111898850A - Method and system for calculating heat supply capacity of electric heating comprehensive energy system with flexible thermal power plant - Google Patents

Abstract

The embodiment of the present invention discloses a method and system for calculating the heating capacity of an electrothermal integrated energy system including a flexible thermal power plant, including: S1. Creating a power generation load calculation model corresponding to the flexible thermal power plant, where the power generation load calculation model can be based on The power generation load per unit curve is used to obtain the power generation load curve; S2, a new energy output calculation model corresponding to a flexible thermal power plant is created, and the new energy output calculation model can obtain the new energy power generation based on the new energy power generation capacity per unit curve and installed capacity. Curve; S3. Calculate the heating capacity of the thermal power unit in each time period according to the electrical and thermal characteristics of the thermal power unit of the thermal power plant; S4. Create the total heating capacity model of all the thermal power units of the thermal power plant to calculate the total heating capacity of all the thermal power units of the entire system by time period. heating capacity. The invention can calculate the heating capacity of the electric-heat integrated energy system including the flexible thermal power plant in each time period, reveal the corresponding relationship between the power generation and the heat supply of the electric-heat integrated energy system including the flexible thermal power plant, and can be used for the provincial-level electric-heat integrated energy system. Provide a reference basis for heating planning.

Description

A method for calculating the heating capacity of an electrothermal integrated energy system with a flexible thermal power plant and system

technical field

The invention relates to the field of power system planning and design, in particular to a method and system for calculating the heating capacity of an electrothermal integrated energy system including a flexible thermal power plant.

Background technique

In the case of preferentially accepting renewable energy, calculating the heating capacity of the thermal power plant after the flexibility transformation can provide a reference for decision-making departments to formulate heating planning.

In recent years, the phenomenon of wind abandonment caused by "wind-heat conflict" in the three northern regions of my country during the winter heating period is very serious. , its essence is to change the traditional thermal power plant's "heat-based electricity" operation mode to "electricity-based heat" operation mode, that is, to give priority to renewable energy, and then to co-generate heat according to the remaining power generation space. If the power generation space is insufficient Insufficient heat supply caused by co-generation, and then use other methods to compensate. With the continuous increase of heating area in my country, in the current situation of severe wind-heat conflict in the northern region, it is difficult to meet the heating requirements only through the co-generation of thermal power units, and more heating capacity needs to be tapped for thermal power plants.

In order to reduce the electrical output of the extraction-condensing unit and improve the heating capacity of the unit, the flexible removal technology of low-pressure cylinders has been developed in recent years, and has been applied in many thermal power plant renovation projects. When the traditional extraction-condensing thermal power unit is running, in order to ensure the stable operation of the low-pressure cylinder, at least about 5% to 10% of the steam needs to enter the low-pressure cylinder for work, and then be cooled in the condenser. In order to fully improve the co-generation heating capacity of the unit and reduce the power output of the unit, the flexible removal technology of the low-pressure cylinder has been developed in recent years, and has been applied in many thermal power plant renovation projects. This technology can realize the unit online flexibly cut off/put into low-pressure cylinder inlet steam operation (only keep a very small amount of cooling steam). Before the removal, the unit operates in the extraction and condensation condition; after the removal, the exhaust steam from the medium-pressure cylinder is basically extracted for heating, and the low-pressure cylinder operates with "zero output" under high vacuum conditions. Back pressure condition under the cylinder. When the extraction-condensing thermal power unit is cut off in the low-pressure cylinder, the waste heat after the steam entering the steam turbine is fully utilized. Therefore, under the condition of a given electrical load, the co-generation heating capacity has reached the maximum, and it is difficult to continue to improve.

SUMMARY OF THE INVENTION

Based on this, in order to solve the deficiencies in the existing technology, a method for calculating the heating capacity of an electrothermal integrated energy system with a flexible thermal power plant is proposed.

A method for calculating the heating capacity of an electrothermal integrated energy system including a flexible thermal power plant, characterized in that it includes:

S1. Create a power generation load calculation model corresponding to a flexible thermal power plant, where the power generation load calculation model can obtain a power generation load curve based on a power generation load per-unit curve;

S2. Create a new energy output calculation model including a flexible thermal power plant, and the new energy output calculation model can obtain a new energy power generation power curve based on the new energy power generation capacity per-unit curve and installed capacity;

S3. According to the electrical and thermal characteristics of the thermal power unit of the thermal power plant, calculate the heating capacity of the thermal power unit in each period;

S4. Create a total heating capacity model of all the thermal power units of the thermal power plant to calculate the total heating capacity of all the thermal power units of the entire system by time period, and obtain index data representing the heating capacity of the entire system based on the total heating capacity to provide users with Thermal planning decisions provide reference data.

Optionally, in one embodiment, the step of calculating the heating capacity of the thermal power unit in each time period in S3 includes:

S31. Create a traditional thermal power unit heating capacity calculation model to calculate the heating capacity of the traditional extraction steam thermal power unit, that is, when the electrical load borne by the traditional extraction steam thermal power unit is P _G,e , the corresponding maximum co-generation supply The formula for calculating thermal power is:

Among them, _cv is the reduction value of the power generation power corresponding to each extraction unit of heat supply when the steam intake is constant; P _B,e is the electric output corresponding to the maximum thermal output of the thermal power unit; P _emax are the maximum generating power of the extraction steam unit under pure condensing condition; c _m is the electric-to-heat ratio of the extraction steam unit under the back pressure condition; P _e0 is the operating line and the back pressure condition of the extraction steam unit. the intersection of the vertical axes;

S32. Create a calculation model for the heating capacity of the thermal power unit after the low-voltage cylinder is removed flexibly to calculate the heating capacity of the thermal power unit after the low-voltage cylinder is removed flexibly, that is, for the thermal power unit after the low-voltage cylinder is removed and transformed, when the electrical load it undertakes is P _{G , e} , the corresponding maximum co-generation heating power is calculated, and the corresponding calculation formula is:

Among them, P _{E, e} represents the maximum generating power of the unit under the condition of co-generation after the low-pressure cylinder is removed;

S33: Create a calculation model for the heating capacity of the thermoelectric unit that removes the low-pressure cylinder and configures the electric boiler to calculate the heating capacity of the thermoelectric unit that removes the low-pressure cylinder and configures the electric boiler. When the load is P _G,e , the corresponding maximum co-generation heating power is calculated, and the corresponding calculation formula is:

Among them, P _E,h represents the maximum heating power of the unit under the condition of co-production after the low pressure cylinder is removed; P _G',h and P _G,h represent the electrical load PG,e of the unit before and after the low pressure cylinder is removed η _EB represents the electric heating efficiency of the electric boiler; P _B,h is the maximum heating power of the extraction-condensing unit.

Optionally, in one embodiment, the step of creating the total heating capacity model of all thermal power units in S4 includes:

S41. The total heating capacity model of all thermal power units is set as the objective function, and the corresponding formula is:

为热电机组l在t时段的整体供热功率，

为热电机组l配置的电锅炉在t时段的电制热功率，

为第l个热电机组，K为联产供热的优先利用系数，其中

为系统中所有热电机组c_m的最大值，

分别为风电的发电能力和上网功率，

分别为光伏发电的发电能力和上网功率，R为可再生能源的优先利用系数，其中

T为系统调度周期的时段数；where:

is the overall heating power of the thermal power unit l in the period t,

The electric heating power of the electric boiler configured for the thermal power unit l in the period t,

is the lth thermal power unit, K is the priority utilization coefficient of co-generation heating, where

is the maximum value of cm of all _{thermoelectric} units in the system,

are the wind power generation capacity and on-grid power, respectively,

are the power generation capacity and on-grid power of photovoltaic power generation respectively, R is the priority utilization coefficient of renewable energy, where

T is the period number of the system scheduling cycle;

S42. Set the constraints of the total heating capacity model of all thermal power units, including:

(1) Power balance constraints, the corresponding formula is:

分别为在t时段系统的净受入电功率、核电发电功率、水电发电功率、风电上网功率、光伏发电上网功率、热电机组l发电功率和纯凝机组k发电功率；

为系统发电负荷；

为热电机组l配置的电锅炉在t时段的电制热功率；where:

are the net incoming electric power, nuclear power generation power, hydroelectric power generation power, wind power grid power, photovoltaic power grid power, thermal power unit l power generation power and pure condensing unit k power generation power in period t, respectively;

Power generation load for the system;

The electric heating power of the electric boiler configured for the thermal power unit 1 in the period t;

(2) System capacity balance constraints, the corresponding formula is:

为水电在t时段的可调容量；x、y为风电和光伏发电的可信容量系数，所述系统根据风电、光伏预测区间的下边界确定；

分别为热电机组l、纯凝机组k在t时段的可调容量，U^k,t为纯凝机组在t时段的启停状态；

为纯凝机组k的装机容量；z为系统的旋转备用系数；where:

is the adjustable capacity of hydropower in period t; x and y are the credible capacity coefficients of wind power and photovoltaic power generation, and the system is determined according to the lower boundary of the wind power and photovoltaic power generation forecast interval;

are the adjustable capacity of the thermal power unit l and the pure condensing unit k in the period t, respectively, and U ^{k, t} is the start-stop state of the pure condensing unit in the period t;

is the installed capacity of pure condensing unit k; z is the rotating reserve coefficient of the system;

(3) Constraints on the operating interval of the pure condensing unit, and the corresponding formula is:

为纯凝机组k的最小发电功率；where:

is the minimum generating power of pure condensing unit k;

(4) The starting and stopping constraints of pure condensing units keep the starting and stopping state unchanged in the whole scheduling period T, and the corresponding formula is:

(5) Constraints on the operating interval of the unit with the ability to flexibly remove the low-pressure cylinder, the corresponding formula for unit 1 in the period t is:

为联产供热功率；

为联产供热功率

对应的电功率；

为机组在进汽量不变情况下切除低压缸后的电功率下调值；

分别为低压缸不切除时的发电功率和供热功率；

分别为低压缸切除时的发电功率和供热功率；

表示纯凝工况下机组和最小电出力；P_hmin表示联产工况下机组和最小热出力；In the formula: I ^{l, t} is the start-stop state of the low-pressure cylinder, 0 means start-up, 1 means stop;

Heating power for co-generation;

Heating power for cogeneration

corresponding electric power;

It is the lower value of electric power after the low-pressure cylinder is cut off when the steam intake remains unchanged;

are the power generation and heating power when the low-pressure cylinder is not cut off, respectively;

are the power generation and heating power when the low-pressure cylinder is removed;

represents the unit and minimum electrical output under pure condensing conditions; P _hmin represents the unit and minimum thermal output under co-generation conditions;

(6) Constraints on the adjustable capacity of units with flexible removal of low-pressure cylinders, and the corresponding formula is:

(7) Renewable energy output constraints, the corresponding formula is:

(8) The capacity constraints of electric boilers, the corresponding formulas are:

为热电机组l所配置电锅炉的最大容量。where:

The maximum capacity of the electric boiler configured for the thermal power unit 1.

In addition, in order to solve the shortcomings of the traditional technology, a heating capacity calculation system of an electro-thermal integrated energy system with a flexible thermal power plant is also proposed.

A heating capacity calculation system for an electric-heat integrated energy system with a flexible thermal power plant, comprising:

a first model creation unit, configured to create a power generation load calculation model corresponding to a thermal power plant with flexibility, where the power generation load calculation model can obtain a power generation load curve based on a power generation load per-unit curve;

The second model creation unit is used to create a new energy output calculation model corresponding to the flexible thermal power plant, and the new energy output calculation model can obtain the new energy power generation power curve based on the new energy power generation capacity per unit curve and the installed capacity;

a first calculation unit, which is used to calculate the heating capacity of the thermal power unit in each time period according to the electrothermal characteristics of the thermal power unit of the thermal power plant;

The third model creation unit is used to create a model of the total heating capacity of all the thermal power units of the thermal power plant to calculate the total heating capacity of all the thermal power units of the entire system on a time-by-period basis, and to obtain and characterize the heating capacity of the entire system based on the total heating capacity The index data can provide reference data for users' heating planning decisions.

Optionally, in one embodiment, the step of calculating the heating capacity of the thermal power unit in each time period in the first calculation unit includes:

Create the heating capacity calculation model of traditional thermal power unit to calculate the heating capacity of the traditional extraction steam power unit, that is, when the electrical load borne by the traditional extraction steam thermal power unit is P _G,e , the corresponding maximum co-generation heating power The calculation formula is:

Among them, _cv is the reduction value of the power generation power corresponding to each extraction unit of heat supply when the steam intake is constant; P _B,e is the electric output corresponding to the maximum thermal output of the thermal power unit; P _emax are the maximum generating power of the extraction steam unit under pure condensing condition; c _m is the electric-to-heat ratio of the extraction steam unit under the back pressure condition; P _e0 is the operating line and the back pressure condition of the extraction steam unit. the intersection of the vertical axes;

Create a calculation model for the heating capacity of the thermal power unit after flexibly removing the low-voltage cylinder to calculate the heating capacity of the thermal power unit after the low-voltage cylinder is flexibly removed, that is, for the thermal power unit after the low-voltage cylinder is removed and reconstructed, when its electrical load is P _G,e , the corresponding maximum co-generation heating power is calculated, and the corresponding calculation formula is:

Among them, P _{E, e} represents the maximum generating power of the unit under the condition of co-generation after the low-pressure cylinder is removed;

Create a calculation model for the heating capacity of the thermoelectric unit that removes the low-pressure cylinder and configures the electric boiler to calculate the heating capacity of the thermoelectric unit that removes the low-pressure cylinder and configures the electric boiler. When P _G,e , the corresponding maximum co-generation heating power is calculated, and the corresponding calculation

The formula is:

Among them, P _E,h represents the maximum heating power of the unit under the condition of co-generation after the low-pressure cylinder is removed; P _G',h and P _G,h represent the electrical load P _G, The maximum co-generation heating power under _e ; η _EB represents the electric heating efficiency of the electric boiler; P _B,h is the maximum heating power of the extraction-condensing unit.

Optionally, in one embodiment, the step of creating the total heating capacity model of all thermal power units in the third model creation unit includes:

Firstly, the objective function of the total heating capacity model of all thermal power units is set, and the corresponding formula is:

为热电机组l在t时段的整体供热功率，

为热电机组l配置的电锅炉在t时段的电制热功率，

为第l个热电机组，K为联产供热的优先利用系数，其中

为系统中所有热电机组c_m的最大值，

分别为风电的发电能力和上网功率，

分别为光伏发电的发电能力和上网功率，R为可再生能源的优先利用系数，其中

T为系统调度周期的时段数。where:

is the overall heating power of the thermal power unit l in the period t,

The electric heating power of the electric boiler configured for the thermal power unit l in the period t,

is the lth thermal power unit, K is the priority utilization coefficient of co-generation heating, where

is the maximum value of cm of all _{thermoelectric} units in the system,

are the wind power generation capacity and on-grid power, respectively,

are the power generation capacity and on-grid power of photovoltaic power generation respectively, R is the priority utilization coefficient of renewable energy, where

T is the period number of the system scheduling cycle.

Next, set the constraints of the total heating capacity model of all thermal power units, including:

(1) Power balance constraints, the corresponding formula is:

分别为在t时段系统的净受入电功率、核电发电功率、水电发电功率、风电上网功率、光伏发电上网功率、热电机组l发电功率和纯凝机组k发电功率；

为系统发电负荷；

为热电机组l配置的电锅炉在t时段的电制热功率；where:

are the net incoming electric power, nuclear power generation power, hydroelectric power generation power, wind power grid power, photovoltaic power grid power, thermal power unit l power generation power and pure condensing unit k power generation power in period t, respectively;

Power generation load for the system;

The electric heating power of the electric boiler configured for the thermal power unit 1 in the period t;

(2) System capacity balance constraints, the corresponding formula is:

为水电在t时段的可调容量；x、y为风电和光伏发电的可信容量系数，即根据风电、光伏预测区间的下边界确定；

分别为热电机组l、纯凝机组k在t时段的可调容量，U^k,t为纯凝机组在t时段的启停状态；

为纯凝机组k的装机容量；z为系统的旋转备用系数；where:

is the adjustable capacity of hydropower in period t; x and y are the credible capacity coefficients of wind power and photovoltaic power generation, which are determined according to the lower boundary of the wind power and photovoltaic forecast intervals;

are the adjustable capacity of the thermal power unit l and the pure condensing unit k in the period t, respectively, and U ^{k, t} is the start-stop state of the pure condensing unit in the period t;

is the installed capacity of pure condensing unit k; z is the rotating reserve coefficient of the system;

(3) Constraints on the operating interval of the pure condensing unit, and the corresponding formula is:

为纯凝机组k的最小发电功率；where:

is the minimum generating power of pure condensing unit k;

(4) The starting and stopping constraints of pure condensing units keep the starting and stopping state unchanged in the whole scheduling period T, and the corresponding formula is:

(5) Constraints on the operating interval of the unit with the ability to flexibly remove the low-pressure cylinder, the corresponding formula for unit 1 in the period t is:

为联产供热功率；

为联产供热功率

对应的电功率；

为机组在进汽量不变情况下切除低压缸后的电功率下调值；

分别为低压缸不切除时的发电功率和供热功率；

分别为低压缸切除时的发电功率和供热功率；P_emin表示纯凝工况下机组和最小电出力；P_hmin表示联产工况下机组和最小热出力；In the formula: I ^{l, t} is the start-stop state of the low-pressure cylinder, 0 means start-up, 1 means stop;

Heating power for co-generation;

Heating power for cogeneration

corresponding electric power;

It is the lower value of electric power after the low-pressure cylinder is cut off when the steam intake remains unchanged;

are the power generation and heating power when the low-pressure cylinder is not cut off, respectively;

are the power generation and heating power when the low-pressure cylinder is cut off, respectively; P _emin represents the unit and the minimum electrical output under the pure condensing condition; P _hmin represents the unit and the minimum thermal output under the co-generation condition;

(6) Constraints on the adjustable capacity of units with flexible removal of low-pressure cylinders, and the corresponding formula is:

(7) Renewable energy output constraints, the corresponding formula is:

(8) The capacity constraints of electric boilers, the corresponding formulas are:

为热电机组l所配置电锅炉的最大容量。where:

The maximum capacity of the electric boiler configured for the thermal power unit 1.

Implementing the embodiment of the present invention will have the following beneficial effects:

The invention can calculate the heating capacity of the electric-heat integrated energy system including the flexible thermal power plant in each time period, and can reveal the corresponding relationship between the power generation and the heat supply of the electric-heat integrated energy system including the flexible thermal power plant, which can be used for the provincial-level electric-heat integrated energy system. Provide reference data for heating planning.

Description of drawings

In order to explain the embodiments of the present invention or the technical solutions in the prior art more clearly, the following briefly introduces the accompanying drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only These are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can also be obtained according to these drawings without creative efforts.

in:

Fig. 1 is the corresponding step flow chart of the method of the present invention;

2 is a power generation load curve during a heating period in a specific embodiment;

Fig. 3 is a per-unit value curve of wind power output during heating period in a specific embodiment;

4 is a per-unit value curve of photovoltaic power output during a heating period in a specific embodiment;

Fig. 5 is a power balance diagram after the thermoelectric unit is configured with an electric boiler in a specific embodiment;

Fig. 6 is a heating capacity curve of the system before and after the transformation of the unit in a specific embodiment.

Detailed ways

In order to make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention, but not to limit the present invention.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terms used herein in the description of the present invention are for the purpose of describing specific embodiments only, and are not intended to limit the present invention. It will be understood that the terms "first", "second", etc., as used herein, may be used herein to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish a first element from another element. For example, a first element could be termed a second element, and, similarly, a second element could be termed a first element, without departing from the scope of the present application. Both the first element and the second element are elements, but they are not the same element.

In this case, on the basis of the flexible removal technology of the low-voltage cylinder, by adding an electric boiler to the thermal power unit, and by converting the excess power caused by the electric-heat coupling into heat energy by using the electric boiler, the heating level can be improved on the premise of further satisfying the power output; In addition, the smaller the electrical load undertaken by the thermal power unit after the electric boiler is configured, the greater its total heating capacity. Therefore, with the continuous increase in the penetration ratio of renewable energy in the power system on the power generation side, after the system preferentially consumes renewable energy , the thermal power plant equipped with electric boilers can simultaneously meet the needs of the power system side to consume new energy and the heating system side to increase the proportion of clean energy heating, which is an effective means to achieve the coordinated development of the two. That is, the present invention can calculate the heating capacity of the electrothermal integrated energy system including the flexible thermal power plant, help planning decision makers to tap the heating capacity of the thermal power plant and provide reference data for heating planning decisions.

Based on the above purpose, in this embodiment, a method for calculating the heating capacity of an electro-thermal integrated energy system with a flexible thermal power plant is proposed, which selects the data of a certain day in the heating period to clearly and completely analyze the technical solutions in the embodiments of the present invention. Description: As shown in Figure 1, the method specifically includes: S1. Create a power generation load calculation model corresponding to a thermal power plant with flexibility. The power generation load calculation model can obtain the power generation load curve based on the power generation load per unit curve, that is, the power generation load per unit The power generation load curve is constructed based on the curve to simulate the hourly power generation load of the system. The specific curve is constructed by the user with reference to the power generation load per unit curve according to the actual system and design requirements; preferably, as shown in Figure 2, the maximum load can be set It is 3803MW, and the minimum load can be 2253MW; S2. Create a new energy output calculation model including flexible thermal power plants. The new energy output calculation model can obtain the new energy power generation power curve based on the new energy power generation capacity per unit curve and installed capacity. That is, by multiplying the per-unit curve of new energy power generation capacity by the installed capacity, the hourly power generation curve of new energy can be obtained, as shown in Figure 3-4. The specific curve is constructed by the user according to the actual system and design requirements with reference to the per-unit curve of new energy power generation capacity. Preferably, the new energy includes at least wind energy and solar energy; S3, according to the electrothermal characteristics of the thermal power unit of the thermal power plant, calculate the heating capacity of the thermal power unit at each time period; S4, create the total heating capacity of all the thermal power units of the thermal power plant The model calculates the total heating capacity of all thermal power units in the entire system by time period, and obtains index data representing the heating capacity of the entire system based on the total heating capacity to provide reference data for users to make heating planning decisions; the index data at least includes A continuous curve, probability distribution, guaranteed capacity at a given confidence level, etc., that characterize the heating capacity of the entire system.

In some specific embodiments, the step of calculating the heating capacity of the thermal power unit in each time period in S3 includes:

S31. Create a traditional thermal power unit heating capacity calculation model to calculate the heating capacity of the traditional extraction steam thermal power unit, that is, when the electrical load borne by the traditional extraction steam thermal power unit is P _G,e , the corresponding maximum

The calculation formula of cogeneration heating power is:

Among them, _cv is the reduction value of the power generation power corresponding to each extraction unit of heat supply when the steam intake is constant; P _B,e is the electric output corresponding to the maximum thermal output of the thermal power unit; P _emax are the maximum generating power of the extraction steam unit under pure condensing condition; c _m is the electric-to-heat ratio of the extraction steam unit under the back pressure condition; P _e0 is the operating line and the back pressure condition of the extraction steam unit. the intersection of the vertical axes;

S32. Create a calculation model for the heating capacity of the thermal power unit after the low-voltage cylinder is removed flexibly to calculate the heating capacity of the thermal power unit after the low-voltage cylinder is removed flexibly, that is, for the thermal power unit after the low-voltage cylinder is removed and transformed, when the electrical load it undertakes is P _{G , e} , the corresponding maximum co-generation heating power is calculated, and the corresponding calculation formula is:

Among them, P _E,e represents the maximum generating power of the unit under the condition of co-generation after the low-pressure cylinder is removed.

S33: Create a calculation model for the heating capacity of the thermoelectric unit that removes the low-pressure cylinder and configures the electric boiler to calculate the heating capacity of the thermoelectric unit that removes the low-pressure cylinder and configures the electric boiler. When the load is P _G,e , the corresponding maximum co-generation heating power is calculated, and the corresponding calculation formula is:

Among them, P _E,h represents the maximum heating power of the unit under the condition of co-generation after the low-pressure cylinder is removed; P _G',h and P _G,h represent the electrical load P _G, The maximum co-generation heating power under _e ; η _EB represents the electric heating efficiency of the electric boiler; P _B,h is the maximum heating power of the extraction-condensing unit. The specific calculation results are shown in Table 1.

Table 1 Unit parameters

In some specific embodiments, as shown in Figures 4-5, the purpose of S4 is to calculate the maximum heating capacity of the system under the condition of preferentially accepting renewable energy, that is, according to the power supply structure of the system and the power supply of each thermal power unit Thermal capacity, under the condition of preferentially accepting renewable energy, with the power balance of the power system side as the constraint, and the maximum heating capacity of the heating system side as the goal, establish a model to calculate the total heating capacity of all thermal power units in the entire system, period by period. Calculate the total heating capacity of all thermal power units in the entire system. Specifically, the corresponding steps of creating the total heating capacity model of all thermal power units include:

S41. Since the thermal power unit will always give priority to the use of the generator for co-generation heat supply, the electric boiler can be used to supply heat with the remaining capacity of the boiler of the unit; then the total power supply of all the thermal power units is correspondingly set.

The objective function of thermal capacity model, its corresponding formula is:

为热电机组l在t时段的整体供热功率，

为热电机组l配置的电锅炉在t时段的电制热功率，

为第l个热电机组，K为联产供热的优先利用系数，其中

为系统中所有热电机组c_m的最大值，where:

is the overall heating power of the thermal power unit l in the period t,

The electric heating power of the electric boiler configured for the thermal power unit l in the period t,

is the lth thermal power unit, K is the priority utilization coefficient of co-generation heating, where

is the maximum value of cm of all _{thermoelectric} units in the system,

分别为风电的发电能力和上网功率，

分别为光伏发电的发电能力和上网功率，R为可再生能源的优先利用系数，其中

T为系统调度周期的时段数。

are the wind power generation capacity and on-grid power, respectively,

are the power generation capacity and on-grid power of photovoltaic power generation respectively, R is the priority utilization coefficient of renewable energy, where

T is the period number of the system scheduling cycle.

S42, set the total heating capacity model constraints of all thermal power units, including:

(1) Power balance constraints, the corresponding formula is:

分别为在t时段系统的净受入电功率、核电发电功率、水电发电功率、风电上网功率、光伏发电上网功率、热电机组l发电功率和纯凝机组k发电功率；

为系统发电负荷；

为热电机组l配置的电锅炉在t时段的电制热功率；where:

are the net incoming electric power, nuclear power generation power, hydroelectric power generation power, wind power grid power, photovoltaic power grid power, thermal power unit l power generation power and pure condensing unit k power generation power in period t, respectively;

Power generation load for the system;

The electric heating power of the electric boiler configured for the thermal power unit 1 in the period t;

(2) System capacity balance constraints, the corresponding formula is:

为水电在t时段的可调容量；x、y为风电和光伏发电的可信容量系数，可根据预测区间的下边界确定；

分别为热电机组l、纯凝机组k在t时段的可调容量，U^k,t为纯凝机组在t时段的启停状态；

为纯凝机组k的装机容量；z为系统的旋转备用系数；where:

is the adjustable capacity of hydropower in period t; x and y are the credible capacity coefficients of wind power and photovoltaic power generation, which can be determined according to the lower boundary of the forecast interval;

are the adjustable capacity of the thermal power unit l and the pure condensing unit k in the period t, respectively, and U ^{k, t} is the start-stop state of the pure condensing unit in the period t;

is the installed capacity of pure condensing unit k; z is the rotating reserve coefficient of the system;

(3) Constraints on the operating interval of the pure condensing unit, and the corresponding formula is:

为纯凝机组k的最小发电功率；where:

is the minimum generating power of pure condensing unit k;

(4) The starting and stopping constraints of pure condensing units keep the starting and stopping state unchanged in the whole scheduling period T, and the corresponding formula is:

(5) Constraints on the operating interval of the unit with the ability to flexibly remove the low-pressure cylinder, the corresponding formula for unit 1 in the period t is:

为联产供热功率；

为机组在进汽量不变情况下切除低压缸后的电功率下调值；

分别为低压缸不切除时的发电功率和供热功率；

分别为低压缸切除时的发电功率和供热功率；In the formula: I ^{l, t} is the start-stop state of the low-pressure cylinder, 0 means start-up, 1 means stop;

Heating power for co-generation;

It is the lower value of electric power after the low-pressure cylinder is cut off when the steam intake remains unchanged;

are the power generation and heating power when the low-pressure cylinder is not cut off, respectively;

are the power generation and heating power when the low-pressure cylinder is removed;

(6) Constraints on the adjustable capacity of units with flexible removal of low-pressure cylinders, and the corresponding formula is:

(7) Renewable energy output constraints, the corresponding formula is:

(8) The capacity constraints of electric boilers, the corresponding formulas are:

为热电机组l所配置电锅炉的最大容量。where:

The maximum capacity of the electric boiler configured for the thermal power unit 1.

Based on the above Figures 5-6, it can be seen that the following information can be obtained through the constraints set above: in the period when the power generation space is not sufficient, the heat supply output of the unit is proportional to the power generation space; in the period when the power generation space is abundant, if the system can be adjusted If the capacity is sufficient, the thermal power unit can run at the maximum heating output. If the adjustable capacity of the system is insufficient, the thermal power unit will reduce the heating output. The total heating capacity is inversely proportional to the power generation space of the power plant; and with the reduction of the minimum output rate of the pure condensing unit, the heating capacity of the system under the unmodified and the low-pressure cylinder removal modification scheme has improved, while in the low-pressure cylinder removal The heating capacity under the scheme of retrofitting and configuring electric boilers has decreased.

In addition, in order to solve the shortcomings of the traditional technology, a heating capacity calculation system of an electro-thermal integrated energy system with a flexible thermal power plant is also proposed.

A heating capacity calculation system for an electric-heat integrated energy system with a flexible thermal power plant, comprising:

a first model creation unit, configured to create a power generation load calculation model corresponding to a thermal power plant with flexibility, where the power generation load calculation model can obtain a power generation load curve based on a power generation load per-unit curve;

The second model creation unit is used to create a new energy output calculation model corresponding to the flexible thermal power plant, and the new energy output calculation model can obtain the new energy power generation power curve based on the new energy power generation capacity per unit curve and the installed capacity;

a first calculation unit, which is used to calculate the heating capacity of the thermal power unit in each time period according to the electrothermal characteristics of the thermal power unit of the thermal power plant;

The third model creation unit is used to create a model of the total heating capacity of all the thermal power units of the thermal power plant to calculate the total heating capacity of all the thermal power units of the entire system on a time-by-period basis.

In some specific embodiments, the step of calculating the heating capacity of the thermal power unit in each time period in the first calculation unit includes:

Create the heating capacity calculation model of the traditional thermal power unit to calculate the heating capacity of the traditional extraction _steam thermal power unit.

The heating power calculation formula is:

分别为抽汽式机组在纯凝工况下的最小发电功率、最大发电功率；

分别为抽汽式机组在联产工况下的最小供热功率、最大供热功率，P_e0为抽汽式热电机组背压工况运行线与纵轴的交点；Among them, _cv is the reduction value of the power generation power corresponding to each extraction unit of heat supply of the extraction steam thermal power unit under the condition of a certain amount of steam intake; cm is the electric-to-heat _ratio of the extraction steam thermal power unit under the back pressure condition;

are the minimum and maximum power generation of the extraction steam unit under pure condensing conditions, respectively;

are the minimum heating power and the maximum heating power of the extraction steam unit under the co-generation condition, respectively, and P _e0 is the intersection of the operation line and the vertical axis under the back pressure condition of the extraction steam unit;

Create a calculation model for the heating capacity of the thermal power unit after flexibly removing the low-voltage cylinder to calculate the heating capacity of the thermal power unit after the low-voltage cylinder is flexibly removed, that is, for the thermal power unit after the low-voltage cylinder is removed and reconstructed, when its electrical load is P _G,e , the corresponding maximum co-generation heating power is calculated, and the corresponding calculation formula is:

Create a calculation model for the heating capacity of the thermoelectric unit that removes the low-pressure cylinder and configures the electric boiler to calculate the heating capacity of the thermoelectric unit that removes the low-pressure cylinder and configures the electric boiler. When P _G,e , the corresponding maximum co-generation heating power is calculated, and the corresponding calculation formula is:

In some specific embodiments, the step of creating the total heating capacity model of all thermal power units in the third model creation unit includes:

Firstly, the objective function of the total heating capacity model of all thermal power units is set, and the corresponding formula is:

为热电机组l在t时段的整体供热功率，

为热电机组l配置的电锅炉在t时段的电制热功率，

为第l个热电机组，K为联产供热的优先利用系数，其中

为系统中所有热电机组c_m的最大值，

分别为风电的发电能力和上网功率，

分别为光伏发电的发电能力和上网功率，R为可再生能源的优先利用系数，其中

T为系统调度周期的时段数。where:

is the overall heating power of the thermal power unit l in the period t,

The electric heating power of the electric boiler configured for the thermal power unit l in the period t,

is the lth thermal power unit, K is the priority utilization coefficient of co-generation heating, where

is the maximum value of cm of all _{thermoelectric} units in the system,

are the wind power generation capacity and on-grid power, respectively,

are the power generation capacity and on-grid power of photovoltaic power generation respectively, R is the priority utilization coefficient of renewable energy, where

T is the period number of the system scheduling cycle.

Next, set the constraints of the total heating capacity model of all thermal power units, including:

(1) Power balance constraints, the corresponding formula is:

分别为在t时段系统的净受入电功率、核电发电功率、水电发电功率、风电上网功率、光伏发电上网功率、热电机组l发电功率和纯凝机组k发电功率；

为系统发电负荷；

为热电机组l配置的电锅炉在t时段的电制热功率；where:

are the net incoming electric power, nuclear power generation power, hydroelectric power generation power, wind power grid power, photovoltaic power grid power, thermal power unit l power generation power and pure condensing unit k power generation power in period t, respectively;

Power generation load for the system;

The electric heating power of the electric boiler configured for the thermal power unit 1 in the period t;

(2) System capacity balance constraints, the corresponding formula is:

为水电在t时段的可调容量；x、y为风电和光伏发电的可信容量系数，即根据风电、光伏预测区间的下边界确定；

分别为热电机组l、纯凝机组k在t时段的可调容量，U^k,t为纯凝机组在t时段的启停状态；

为纯凝机组k的装机容量；z为系统的旋转备用系数；where:

is the adjustable capacity of hydropower in period t; x and y are the credible capacity coefficients of wind power and photovoltaic power generation, which are determined according to the lower boundary of the wind power and photovoltaic forecast intervals;

are the adjustable capacity of the thermal power unit l and the pure condensing unit k in the period t, respectively, and U ^{k, t} is the start-stop state of the pure condensing unit in the period t;

is the installed capacity of pure condensing unit k; z is the rotating reserve coefficient of the system;

(3) Constraints on the operating interval of the pure condensing unit, and the corresponding formula is:

为纯凝机组k的最小发电功率；where:

is the minimum generating power of pure condensing unit k;

(4) The starting and stopping constraints of pure condensing units keep the starting and stopping state unchanged in the whole scheduling period T, and the corresponding formula is:

(5) Constraints on the operating interval of the unit with the ability to flexibly remove the low-pressure cylinder, the corresponding formula for unit 1 in the period t is:

为联产供热功率；

为联产供热功率

对应的电功率；

为机组在进汽量不变情况下切除低压缸后的电功率下调值；

分别为低压缸不切除时的发电功率和供热功率；

分别为低压缸切除时的发电功率和供热功率；P_emin表示纯凝工况下机组和最小电出力；P_hmin表示联产工况下机组和最小热出力；In the formula: I ^{l, t} is the start-stop state of the low-pressure cylinder, 0 means start-up, 1 means stop;

Heating power for co-generation;

Heating power for cogeneration

corresponding electric power;

It is the lower value of electric power after the low-pressure cylinder is cut off when the steam intake remains unchanged;

are the power generation and heating power when the low-pressure cylinder is not cut off, respectively;

are the power generation and heating power when the low-pressure cylinder is cut off, respectively; P _emin represents the unit and the minimum electrical output under the pure condensing condition; P _hmin represents the unit and the minimum thermal output under the co-generation condition;

(6) Constraints on the adjustable capacity of units with flexible removal of low-pressure cylinders, and the corresponding formula is:

(7) Renewable energy output constraints, the corresponding formula is:

(8) The capacity constraints of electric boilers, the corresponding formulas are:

为热电机组l所配置电锅炉的最大容量。where:

The maximum capacity of the electric boiler configured for the thermal power unit 1.

To sum up, the present invention essentially discloses a method for calculating the heating capacity of an electrothermal integrated energy system including a flexible thermal power plant, which realizes the calculation of the heating capacity of the system after the low-pressure cylinder of the thermal power unit is flexibly removed and an electric boiler is installed. , according to the power balance and combined with the relevant constraints, from the initial moment, the time series curve of the maximum heating power of the system is simulated and calculated time-by-period; at the same time, based on the curve, various items representing the entire maximum heating power and system heating capacity are constructed. Indicators, such as persistence curve, probability distribution, guaranteed capacity under given confidence, etc., can help planning decision-makers to tap the heating capacity of thermal power plants and provide reference for heating planning decisions.

The above-mentioned embodiments only represent several embodiments of the present application, and the descriptions thereof are relatively specific and detailed, but should not be construed as a limitation on the scope of the patent of the present application. It should be pointed out that for those skilled in the art, without departing from the concept of the present application, several modifications and improvements can be made, which all belong to the protection scope of the present application. Therefore, the scope of protection of the patent of the present application shall be subject to the appended claims.

Claims (6)

1. a method for calculating the heating capacity of an electrothermal integrated energy system containing a flexible thermal power plant, characterized in 1, comprising: S1. Create a power generation load calculation model corresponding to a flexible thermal power plant, where the power generation load calculation model can obtain a power generation load curve based on a power generation load per-unit curve; S2. Create a new energy output calculation model including a flexible thermal power plant, and the new energy output calculation model can obtain a new energy power generation power curve based on the new energy power generation capacity per-unit curve and installed capacity; S3. According to the electrical and thermal characteristics of the thermal power unit of the thermal power plant, calculate the heating capacity of the thermal power unit in each period; S4. Create a total heating capacity model of all the thermal power units of the thermal power plant to calculate the total heating capacity of all the thermal power units of the entire system by time period, and obtain index data representing the heating capacity of the entire system based on the total heating capacity to provide users with Thermal planning decisions provide reference data. 2. The method according to claim 1, wherein the step of calculating the heating capacity of the thermal power unit in each time period in the S3 comprises: S31. Create a traditional thermal power unit heating capacity calculation model to calculate the heating capacity of the traditional extraction steam thermal power unit, that is, when the electrical load borne by the traditional extraction steam thermal power unit is P _G,e , the corresponding maximum co-generation supply The formula for calculating thermal power is:

Among them, _cv is the reduction value of the power generation power corresponding to each extraction unit of heat supply of the extraction steam thermal power unit under the condition of a certain amount of steam intake; cm is the electric-to-heat _ratio of the extraction steam thermal power unit under the back pressure condition; P _B,e is the corresponding electrical output when the thermal output of the thermal power unit is the largest; P _emax is the minimum and maximum power generation of the extraction steam unit under pure condensing conditions; P _e0 is the back pressure of the extraction steam unit. The intersection of the condition line and the vertical axis; S32. Create a calculation model for the heating capacity of the thermal power unit after the low-voltage cylinder is flexibly removed to calculate the heating capacity of the thermal power unit after the low-voltage cylinder is removed flexibly, that is, for the thermal power unit after the low-voltage cylinder is removed and transformed, when the electrical load it undertakes is P _{G , e} , the corresponding maximum co-generation heating power is calculated, and the corresponding calculation formula is:

Among them, P _{E, e} represents the maximum generating power of the unit under the condition of co-generation after the low-pressure cylinder is removed; S33: Create a calculation model for the heating capacity of the thermal power unit with the low-pressure cylinder removed and the electric boiler configured to calculate the heating capacity of the thermal power unit with the low-pressure cylinder removed and the electric boiler configured, that is, for the heat-generating unit after the electric boiler is configured, when it undertakes the electricity When the load is P _G,e , the corresponding maximum co-generation heating power is calculated, and the corresponding calculation formula is:

Among them, P _E,h represents the maximum heating power of the unit under the condition of co-generation after the low-pressure cylinder is removed; P _G',h and P _G,h represent the electrical load P _G, The maximum co-generation heating power under _e ; η _EB represents the electric heating efficiency of the electric boiler; P _B,h is the maximum heating power of the extraction-condensing unit. 3. The method according to claim 2, wherein the step of creating the total heating capacity model of all thermal power units in the S4 comprises: S41. Set the objective function of the total heating capacity model of all thermal power units, and the corresponding formula is:

where:

is the overall heating power of the thermal power unit l in the period t,

The electric heating power of the electric boiler configured for the thermal power unit l in the period t,

is the lth thermal power unit, K is the priority utilization coefficient of co-generation heating, where

is the maximum value of cm of all _{thermoelectric} units in the system,

are the wind power generation capacity and on-grid power, respectively,

are the power generation capacity and on-grid power of photovoltaic power generation respectively, R is the priority utilization coefficient of renewable energy, where

T is the period number of the system scheduling cycle; S42. Set the constraints of the total heating capacity model of all thermal power units, including: (1) Power balance constraints, the corresponding formula is:

where:

are the net incoming electric power, nuclear power generation power, hydroelectric power generation power, wind power grid power, photovoltaic grid power, thermal power unit l power generation power and pure condensing unit k power generation power in period t respectively;

Power generation load for the system;

The electric heating power of the electric boiler configured for the thermal power unit 1 in the period t; (2) System capacity balance constraints, the corresponding formula is:

where:

is the adjustable capacity of hydropower in period t; x and y are the trusted capacity coefficients of wind power and photovoltaic power generation;

are the adjustable capacity of the thermal power unit l and the pure condensing unit k in the period t, respectively, and U ^{k, t} is the start-stop state of the pure condensing unit in the period t;

is the installed capacity of pure condensing unit k; z is the rotating reserve coefficient of the system; (3) Constraints on the operating interval of the pure condensing unit, and the corresponding formula is:

where:

is the minimum generating power of pure condensing unit k; (4) Constraints on start and stop of pure condensing units, which keep the start and stop state unchanged in the entire scheduling period T, and the corresponding formula is:

(5) Constraints on the operating interval of the unit with the ability to flexibly remove the low-pressure cylinder, the corresponding formula for unit 1 in the period t is:

In the formula: I ^{l, t} is the start-stop state of the low-pressure cylinder, 0 means start-up, 1 means stop;

Heating power for co-generation;

Heating power for cogeneration

corresponding electric power;

It is the lower value of electric power after the low-pressure cylinder is cut off when the steam intake remains unchanged;

are the power generation and heating power when the low-pressure cylinder is not cut off, respectively;

are the power generation and heating power when the low-pressure cylinder is removed;

Indicates the unit and minimum electrical output under pure condensing conditions;

Indicates the minimum heat output of the unit under co-generation conditions; (6) Constraints on the adjustable capacity of units with flexible removal of low-pressure cylinders, and the corresponding formula is:

(7) Renewable energy output constraints, the corresponding formula is:

(8) The capacity constraints of electric boilers, the corresponding formulas are:

where:

The maximum capacity of the electric boiler configured for the thermal power unit 1. 4. A heating capacity calculation system for an electrothermal integrated energy system with a flexible thermal power plant, comprising: a first model creation unit, configured to create a power generation load calculation model corresponding to a thermal power plant with flexibility, where the power generation load calculation model can obtain a power generation load curve based on a power generation load per-unit curve; The second model creation unit is used to create a new energy output calculation model corresponding to the flexible thermal power plant, and the new energy output calculation model can obtain the new energy power generation power curve based on the new energy power generation capacity per unit curve and the installed capacity; a first calculation unit, which is used for calculating the heating capacity of the thermal power unit in each time period according to the electrothermal characteristics of the thermal power unit of the thermal power plant; The third model creation unit is used to create a model of the total heating capacity of all the thermal power units of the thermal power plant to calculate the total heating capacity of all the thermal power units of the entire system on a time-by-period basis, and to obtain and characterize the heating capacity of the entire system based on the total heating capacity The index data can provide reference data for users' heating planning decisions. 5. The system according to claim 1, wherein the step of calculating the heating capacity of the thermal power unit in each time period in the first calculation unit comprises: Create the heating capacity calculation model of the traditional thermal power unit to calculate the heating capacity of the traditional extraction steam thermal power unit, that is, when the electrical load borne by the traditional extraction steam thermal power unit is P _G,e , the corresponding maximum co-generation heating power The calculation formula is:

Among them, _cv is the reduction value of the power generation power corresponding to each extraction unit of heat supply of the extraction steam thermal power unit under the condition of a certain amount of steam intake; cm is the electric-to-heat _ratio of the extraction steam thermal power unit under the back pressure condition; P _B,e are the corresponding electrical output when the thermal output of the thermal power unit is the largest; P _emax are the maximum generating power of the extraction steam unit under pure condensing condition; P _e0 is the back pressure operating line of the extraction steam unit and the intersection of the vertical axes; Create a calculation model for the heating capacity of the thermal power unit after flexibly removing the low-voltage cylinder to calculate the heating capacity of the thermal power unit after the low-voltage cylinder is flexibly removed, that is, for the thermal power unit after the low-voltage cylinder is removed and reconstructed, when its electrical load is P _G,e , the corresponding maximum co-generation heating power is calculated, and the corresponding calculation formula is:

Among them, P _{E, e} represents the maximum generating power of the unit under the condition of co-generation after the low-pressure cylinder is removed; Create a calculation model for the heating capacity of the thermoelectric unit that removes the low-pressure cylinder and configures the electric boiler to calculate the heating capacity of the thermoelectric unit that removes the low-pressure cylinder and configures the electric boiler. When P _G,e , the corresponding maximum co-generation heating power is calculated, and the corresponding calculation formula is:

Among them, P _E,h represents the maximum heating power of the unit under the condition of co-generation after the low-pressure cylinder is removed; P _G',h and P _G,h represent the electrical load P _G, The maximum co-generation heating power under _e ; η _EB represents the electric heating efficiency of the electric boiler; P _B,h is the maximum heating power of the extraction-condensing unit. 6. The system according to claim 5, wherein the step of creating the total heating capacity model of all thermal power units in the third model creation unit comprises: Firstly, the objective function of the total heating capacity model of all thermal power units is set, and the corresponding formula is:

where:

is the overall heating power of the thermal power unit l in the period t,

The electric heating power of the electric boiler configured for the thermal power unit l in the period t,

is the lth thermal power unit, K is the priority utilization coefficient of co-generation heating, where

is the maximum value of cm of all _{thermoelectric} units in the system,

are the wind power generation capacity and on-grid power, respectively,

are the power generation capacity and on-grid power of photovoltaic power generation respectively, R is the priority utilization coefficient of renewable energy, where

T is the period number of the system scheduling cycle. Next, set the constraints of the total heating capacity model of all thermal power units, including: (1) Power balance constraints, the corresponding formula is:

where:

are the net incoming electric power, nuclear power generation power, hydroelectric power generation power, wind power grid power, photovoltaic power grid power, thermal power unit l power generation power and pure condensing unit k power generation power in period t, respectively;

Power generation load for the system;

The electric heating power of the electric boiler configured for the thermal power unit 1 in the period t; (2) System capacity balance constraints, the corresponding formula is:

where:

is the adjustable capacity of hydropower in period t; x and y are the credible capacity coefficients of wind power and photovoltaic power generation,

are the adjustable capacity of the thermal power unit l and the pure condensing unit k in the period t, respectively, and U ^{k, t} is the start-stop state of the pure condensing unit in the period t;

is the installed capacity of pure condensing unit k; z is the rotating reserve coefficient of the system; (3) Constraints on the operating interval of the pure condensing unit, and the corresponding formula is:

where:

is the minimum generating power of pure condensing unit k; (4) The starting and stopping constraints of pure condensing units keep the starting and stopping state unchanged in the whole scheduling period T, and the corresponding formula is:

(5) Constraints on the operating interval of the unit with the ability to flexibly remove the low-pressure cylinder, the corresponding formula for unit 1 in the period t is:

In the formula: I ^{l, t} is the start-stop state of the low-pressure cylinder, 0 means start-up, 1 means stop;

Heating power for co-generation;

Heating power for cogeneration

corresponding electric power;

It is the lower value of electric power after the low-pressure cylinder is cut off when the steam intake remains unchanged;

are the power generation and heating power when the low-pressure cylinder is not cut off, respectively;

are the power generation and heating power when the low-pressure cylinder is cut off, respectively; P _emin represents the unit and the minimum electrical output under the pure condensing condition; P _hmin represents the unit and the minimum thermal output under the co-generation condition; (6) Constraints on the adjustable capacity of units with flexible removal of low-pressure cylinders, and the corresponding formula is:

(7) Constraints on renewable energy output, the corresponding formula is:

(8) The capacity constraints of electric boilers, the corresponding formulas are:

where:

The maximum capacity of the electric boiler configured for the thermal power unit 1.

Images