Coordinated control method and system for regulating electrical and thermal loads of cogeneration units

Abstract

The invention discloses a coordinated control method and system for regulating the electric and thermal loads of a cogeneration unit. The method comprises the following steps: setting a coordinated control system, taking a controlled parameter as a feedback regulation amount, taking a regulation signal as a feedforward compensation amount, the unit unit calculating a total load instruction, and regulating the electric load of the cogeneration unit with the feedback regulation amount and the feedforward compensation amount, the boiler control system receiving the total load instruction and calculating the first fuel regulation amount of the boiler, and at the same time regulating the second fuel regulation amount of the boiler with the feedback regulation amount and the feedforward compensation amount, and the heating steam control system regulating the thermal load of the cogeneration unit according to the feedback regulation amount and the feedforward compensation amount, the system comprises a unit unit control system, a boiler control system, a heating steam control system and a cogeneration unit, which can respectively process the electric and thermal loads and can maintain the beneficial effect of stable operation of the unit.

Description

Technical Field

[0001] The invention belongs to the control field of cogeneration thermal power generating sets, and in particular relates to a method system for regulating and coordinating control of electrical and thermal loads of cogeneration sets. Background Art

[0002] Nowadays, the scale of cogeneration generating units is gradually expanding, and the demand for heating steam and industrial steam is also gradually increasing. However, there is no suitable control system for cogeneration units. The traditional unit coordination control system is designed for pure generating units, which has poor applicability to cogeneration units. The entire control system not only lacks the means to adjust the heating steam extraction load, but also the fuel quantity instruction B received by the boiler control system is only issued based on the electrical load, and the rapid adaptability of the boiler is not good. Summary of the invention

[0003] In order to solve the above technical problems, the present invention provides a method system for regulating and coordinating the electrical and thermal loads of a cogeneration unit.

[0004] The specific plan is as follows:

[0005] Coordinated control method for electrical and thermal load regulation of cogeneration units,

[0006] S1): Setting a coordinated control system for controlling the cogeneration unit, the control system comprising a unit control system, a boiler control system and a heating steam control system;

[0007] S2): Different controlled parameters are set in different control systems, and the controlled parameters are used as feedback adjustment quantities; at the same time, different adjustment signals are set in different control systems, and the adjustment signals are used as feedforward compensation quantities;

[0008] S3): The unit control system calculates the total load command G0 according to the heat load and electric load commands, and at the same time, the unit control system adjusts the electric load of the cogeneration unit with the feedback adjustment amount and the feedforward compensation amount;

[0009] S4): The boiler control system receives the total load instruction and calculates the first fuel adjustment amount of the boiler. At the same time, the boiler control system adjusts the second fuel adjustment amount of the boiler with the feedback adjustment amount and the feedforward compensation amount;

[0010] S5): The heating steam control system adjusts the heat load of the cogeneration unit according to the feedback adjustment amount and the feedforward compensation amount.

[0011] The coordinated control method is a machine and furnace coordinated control method.

[0012] The unit control system stores a thermal operating diagram calculation loop and a turbine main steam valve calculation loop, wherein:

[0013] The thermal operating diagram calculation loop calculates a total load instruction using a thermal load instruction and an electrical load instruction;

[0014] The main steam valve operation loop of the steam turbine uses the heat load difference △Q and the electric power difference △N as the feedforward compensation amount, and at the same time uses the main steam pressure difference △P in the cogeneration unit as the controlled amount for feedback regulation to control the electric load regulation of the cogeneration unit;

[0015] The heat load difference △Q is the difference between the actual load Q of the steam turbine exhaust heat supply in the cogeneration unit and the given value Q0 of the steam turbine exhaust heat supply load;

[0016] The electric power difference △N is the actual power generation power N of the cogeneration unit. e The difference with the given value N0 of the power generation of the cogeneration unit;

[0017] The main steam pressure difference △P is the actual steam pressure value P at the inlet of the steam turbine in the cogeneration unit. T The difference between the given value P0 of the steam pressure at the turbine inlet in the cogeneration unit.

[0018] The thermal operating diagram calculation loop calculates the total load instruction G0 according to the load calculation function, and the load calculation function is:

[0019]

[0020] Where D is the total load, is the slope of the pure condensation condition line is the power generation, is a constant, and It's about heat supply The heat supply function is:

[0021]

[0022] in, is the heat supply; heat supply function Through different groups ( , b) obtained by numerical fitting.

[0023] The boiler control system stores a boiler command operation loop, which receives a total load command G0 and performs a primary adjustment of the boiler fuel quantity B according to the total load command G0;

[0024] At the same time, the boiler command operation loop uses the heat load difference △Q and the main steam pressure difference △P as feedforward compensation, and uses the electric power difference △N as the controlled quantity for feedback adjustment to control the secondary adjustment of the boiler fuel quantity B.

[0025] The heating steam control system stores a heating operation loop, which uses the electric power difference △N and the main steam pressure difference △P as feedforward compensation quantities, and at the same time uses the heat load difference △Q as the controlled quantity for feedback regulation to control the heat load regulation of the cogeneration unit.

[0026] A coordinated control system for regulating electrical and thermal loads of a cogeneration unit, comprising a unit control system, a boiler control system, a heating steam control system and a cogeneration unit; wherein the unit control system comprises a first processing unit, a second processing unit and a load instruction input unit, the boiler control system comprises a boiler controller and a boiler regulating unit, and the heating steam control system comprises a heating controller, wherein the load instruction input unit is electrically connected to the first processing unit, the second processing unit and the boiler controller are electrically connected to the first processing unit, the boiler controller is electrically connected to the boiler regulating unit, the boiler controller, the second processing unit and the heating controller are all electrically connected to the cogeneration unit, the boiler controller, the second processing unit and the heating controller are all provided with an adder, the second processing unit and the heating controller are both electrically connected to the first processing unit via the adder, and the boiler controller is electrically connected to the cogeneration unit via the adder.

[0027] The cogeneration unit includes a boiler, a high-pressure cylinder of a steam turbine, an intermediate-pressure cylinder of a steam turbine, a low-pressure cylinder of a steam turbine and a generator. A main steam regulating valve is arranged between the boiler and the high-pressure cylinder of the steam turbine. The boiler is connected to the high-pressure cylinder pipeline of the steam turbine through the main steam regulating valve. A reheater is arranged in the boiler. The high-pressure cylinder of the steam turbine is connected to the intermediate-pressure cylinder pipeline of the steam turbine through the reheater. A steam supply regulating valve is arranged on the intermediate-pressure cylinder of the steam turbine. A low-pressure regulating valve is arranged on the low-pressure cylinder of the steam turbine. The intermediate-pressure cylinder of the steam turbine extracts steam through the steam supply regulating valve. The intermediate-pressure cylinder of the steam turbine is connected to the low-pressure cylinder pipeline of the steam turbine through the low-pressure regulating valve. The generator is rotatably connected to the low-pressure cylinder of the steam turbine. A condenser, a feedwater pump and a feedwater control valve are arranged between the low-pressure cylinder of the steam turbine and the boiler. The low-pressure cylinder of the steam turbine is connected to the boiler pipeline through the condenser, the feedwater pump and the feedwater control valve in sequence.

[0028] The main steam regulating valve is electrically connected to the second processing unit, and the low pressure regulating valve is electrically connected to the heating controller. The boiler is provided with a pipeline pressure sensor, the steam supply regulating valve is provided with a heat meter, and the generator is provided with an electric power sensor.

[0029] The boiler controller, the second processing unit and the heating controller are all electrically connected to the pipeline pressure sensor via an adder;

[0030] The boiler controller, the second processing unit and the heating controller are all electrically connected to the heat meter via an adder;

[0031] The boiler controller, the second processing unit and the heating controller are all electrically connected to the pipeline electric power sensor through an adder.

[0032] The boiler controller, the second processing unit and the heating controller are all electrically connected to the load instruction input unit via an adder.

[0033] The load instruction input unit includes an electric load instruction input unit, a thermal load instruction input unit and a pressure instruction input unit. The electric load instruction input unit and the thermal load instruction input unit are both electrically connected to the first processing unit. The electric load instruction input unit, the thermal load instruction input unit and the pressure instruction input unit are touch screens.

[0034] The present invention discloses a method system for regulating and coordinating the electric and thermal loads of a cogeneration unit. Compared with the traditional coordinated control system of a unit unit, the control system has the following advantages:

[0035] (1) The boiler coal feed rate instruction is based on the total load calculated based on the thermal condition diagram, rather than the electrical load of the traditional coordinated control system. In comparison, it can achieve precise one-time adjustment on the boiler side;

[0036] (2) Introducing a heating regulation system, the heating regulation control adopts feedback regulation of the heating extraction steam flow;

[0037] (3) Multivariable feedforward design of the unit.

[0038] The heating system controller uses the PID controller input to specially introduce the electric power difference △N and the main steam pressure difference △P signals to achieve compensation for the heating control system. That is, when the boiler combustion conditions are disturbed or the opening of the turbine main steam regulating valve is disturbed, the heating load, that is, the heating extraction steam flow rate, is kept as unchanged as possible.

[0039] In addition to using electric power N as the regulated variable for feedback regulation, the boiler controller also uses the PID controller input to introduce heat load difference △Q and main steam pressure difference △P signals to achieve compensation for the boiler control system. When the opening of the turbine main steam regulating valve or the low-pressure regulating valve is disturbed, the boiler operating conditions can be quickly adapted.

[0040] In addition to using the main steam pressure P as the feedback regulation of the regulated variable, the controller uses the PID controller input to introduce the electric power difference △N and heat load difference △Q signals to achieve compensation for the turbine control system. When the boiler combustion condition or the low-pressure regulating valve opening is disturbed, the turbine regulating valve is activated to achieve rapid regulation of the electric power. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1This is a system diagram of the coordinated control principle of the cogeneration generator set.

[0042] Figure 2 This is a schematic diagram of the coordinated control system structure of the cogeneration generator set.

[0043] Figure 3 This is the thermal condition diagram.

[0044] Among them, G0 is the total boiler load instruction, B is the fuel quantity, μ1 is the main steam control valve opening, μ2 is the main steam control valve opening, N e is the actual power generation of the unit, N0 is the given value of the power generation of the unit, P T is the actual steam pressure at the turbine inlet, P0 is the given value of the steam pressure at the turbine inlet, Q is the actual steam extraction heating load of the turbine, and Q0 is the given value of the steam extraction heating load of the turbine. DETAILED DESCRIPTION

[0045] The following will be combined with the accompanying drawings in the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the implementation of the present invention, not all of the implementations. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0046] The invention designs a coordinated control system for cogeneration thermal power generating units, which improves the many problems existing in the application of traditional coordinated control systems to cogeneration thermal power generating units, such as the boiler coal supply instruction is based only on the electrical load, the lack of adjustment means on the heating steam side, the thermoelectric coupling leading to the inability to independently adjust the thermoelectric load, etc., and ensures the supply of electrical and thermal loads by the unit. To achieve this purpose, the invention adds the feedforward design of each control system on the basis of separately designing the boiler control system, the steam turbine control system, and the heating control system, and establishes a coordinated control system for cogeneration thermal power generating units.

[0047] Coordinated control method for electrical and thermal load regulation of cogeneration units,

[0048] S1): Setting a coordinated control system for controlling the cogeneration unit, the control system comprising a unit control system, a boiler control system and a heating steam control system;

[0049] S2): Different controlled parameters are set in different control systems, and the controlled parameters are used as feedback adjustment quantities; at the same time, different adjustment signals are set in different control systems, and the adjustment signals are used as feedforward compensation quantities;

[0050] S3): The unit control system calculates the total load command G0 according to the heat load and electric load commands, and at the same time, the unit control system adjusts the electric load of the cogeneration unit with the feedback adjustment amount and the feedforward compensation amount;

[0051] S4): The boiler control system receives the total load instruction and calculates the first fuel adjustment amount of the boiler. At the same time, the boiler control system adjusts the second fuel adjustment amount of the boiler with the feedback adjustment amount and the feedforward compensation amount;

[0052] S5): The heating steam control system adjusts the heat load of the cogeneration unit according to the feedback adjustment amount and the feedforward compensation amount.

[0053] The coordinated control method is a machine and furnace coordinated control method.

[0054] The unit control system stores a thermal operating diagram calculation loop and a turbine main steam valve calculation loop, wherein:

[0055] The thermal operating diagram calculation loop calculates a total load instruction using a thermal load instruction and an electrical load instruction;

[0056] The main steam valve operation loop of the steam turbine uses the heat load difference △Q and the electric power difference △N as the feedforward compensation amount, and at the same time uses the main steam pressure difference △P in the cogeneration unit as the controlled amount for feedback regulation to control the electric load regulation of the cogeneration unit;

[0057] The heat load difference △Q is the difference between the actual load Q of the steam turbine exhaust heat supply in the cogeneration unit and the given value Q0 of the steam turbine exhaust heat supply load;

[0058] The electric power difference △N is the actual power generation power N of the cogeneration unit. e The difference with the given value N0 of the power generation of the cogeneration unit;

[0059] The main steam pressure difference △P is the actual steam pressure value P at the inlet of the steam turbine in the cogeneration unit. T The difference between the given value P0 of the steam pressure at the turbine inlet in the cogeneration unit.

[0060] The thermal operating diagram calculation loop calculates the total load instruction G0 according to the load calculation function, and the load calculation function is:

[0061]

[0062] Where D is the total load, is the slope of the pure condensation condition line is the power generation, is a constant, and It's about heat supply The heat supply function is:

[0063]

[0064] in, is the heat supply; heat supply function Through different groups ( , b) numerical fitting. The thermal condition diagram is shown in Figure 3 shown.

[0065] The boiler control system stores a boiler command operation loop, which receives a total load command G0 and performs a primary adjustment of the boiler fuel quantity B according to the total load command G0;

[0066] At the same time, the boiler command operation loop uses the heat load difference △Q and the main steam pressure difference △P as feedforward compensation, and uses the electric power difference △N as the controlled quantity for feedback adjustment to control the secondary adjustment of the boiler fuel quantity B.

[0067] The heating steam control system stores a heating operation loop, which uses the electric power difference △N and the main steam pressure difference △P as feedforward compensation quantities, and at the same time uses the heat load difference △Q as the controlled quantity for feedback regulation to control the heat load regulation of the cogeneration unit.

[0068] like Figure 1 As shown, a system diagram of the coordinated control principle of a cogeneration generator set is established according to the method.

[0069] The control principle diagram is provided with a boiler controller 8 and a second processing unit 7, the second processing unit 7 is equivalent to a steam turbine controller, a heating controller 12 and a cogeneration unit 25, and the controlled quantities of the cogeneration unit are respectively the actual power generation N e , actual steam pressure at turbine inlet P T and the actual load value Q of the steam turbine extraction heating; the input quantities are the given steam pressure value P0 at the turbine inlet, the given power generation power N0 of the cogeneration unit and the given value Q0 of the steam turbine extraction heating load.

[0070] The second processing unit 7 is provided with a feedback regulation amount and a feedforward regulation amount, wherein the feedback regulation amount is mainly a steam pressure value ΔP, wherein ΔP= P0-P T ; The feedforward and adjustment quantities are the electric power difference △N and the heat load difference △Q, respectively, wherein △N = N0-N0; △Q = Q0-Q;

[0071] The boiler controller 8 is provided with a feedback regulating amount and a feedforward regulating amount, wherein the feedback regulating amount is the electric power difference △N, and the feedforward regulating amount is respectively the main steam pressure value △P and the heat load difference △Q;

[0072] The heating controller 12 is provided with a feedback regulating variable and a feedforward regulating variable. The feedback regulating variable is the heat load difference ΔQ, and the feedforward regulating variables are the electric power difference ΔN and the main steam pressure value ΔP.

[0073] According to the coordinated control principle system diagram of cogeneration generator sets, a coordinated control system for electrical and thermal load regulation of cogeneration units is established.

[0074] like Figure 2 As shown, a coordinated control system for regulating electrical and thermal loads of a cogeneration unit includes a unit control system, a boiler control system, a heating steam control system and a cogeneration unit; wherein the unit control system includes a first processing unit 9, a second processing unit 8 and a load instruction input unit, the boiler control system includes a boiler controller 7 and a boiler regulating unit, and the heating steam control system includes a heating controller 12, wherein the load instruction input unit is electrically connected to the first processing unit 9, the second processing unit 8 and the boiler controller 7 are electrically connected to the first processing unit 9, the boiler controller 7 is electrically connected to the boiler regulating unit, and the boiler controller 7, the second processing unit 8 and the heating controller 12 are all electrically connected to the cogeneration unit.

[0075] The boiler controller 7 , the second processing unit 8 and the heating controller 12 are all provided with an adder 23 , the second processing unit 8 and the heating controller 12 are electrically connected to the first processing unit 9 via the adder 23 , and the boiler controller 7 is electrically connected to the cogeneration unit via the adder 23 .

[0076] The cogeneration unit includes a boiler 1, a steam turbine high-pressure cylinder 16, a steam turbine intermediate-pressure cylinder 17, a steam turbine low-pressure cylinder 18 and a generator 13. A main steam regulating valve 20 is provided between the boiler and the steam turbine high-pressure cylinder 16. The boiler is connected to the steam turbine high-pressure cylinder 16 through a pipeline through the main steam regulating valve 20. A reheater 2 is provided in the boiler 1. The steam turbine high-pressure cylinder 16 is connected to the steam turbine intermediate-pressure cylinder 17 through a pipeline through the reheater 2.

[0077] The steam turbine intermediate pressure cylinder 17 is provided with a steam supply regulating valve 21, and the steam turbine low pressure cylinder 18 is provided with a low pressure regulating valve 14. The steam turbine intermediate pressure cylinder 17 extracts steam through the steam supply regulating valve 21. The steam turbine intermediate pressure cylinder 17 is connected to the steam turbine low pressure cylinder 18 through a pipeline through the low pressure regulating valve 14, and the generator 13 is rotationally connected to the steam turbine low pressure cylinder 18.

[0078] A condenser 19, a feed water pump 15 and a feed water control valve 3 are provided between the low-pressure cylinder 18 of the steam turbine and the boiler 1. The low-pressure cylinder 18 of the steam turbine is connected to the boiler 1 through a pipeline of the condenser 19, the feed water pump 15 and the feed water control valve 3 in sequence.

[0079] The boiler regulating unit comprises a belt conveyor 4 , a fan 5 and a water pump 6 , and the belt conveyor 4 , the fan 5 and the water pump 6 are all connected to the boiler 1 through a pipeline.

[0080] The main steam regulating valve 20 is electrically connected to the second processing unit 8 , and the low-pressure regulating valve 14 is electrically connected to the heating controller 12 .

[0081] The boiler 1 is provided with a pipeline pressure sensor, the steam supply regulating valve is provided with a heat meter, and the generator 13 is provided with an electric power sensor.

[0082] The boiler controller 7, the second processing unit 8 and the heating controller 12 are all electrically connected to the pipeline pressure sensor via the adder 23;

[0083] The boiler controller 7, the second processing unit 8 and the heating controller 12 are all electrically connected to the heat meter via the adder 23;

[0084] The boiler controller 7, the second processing unit 8 and the heating controller 12 are all electrically connected to the pipeline electric power sensor through the adder 23.

[0085] The boiler controller 7 , the second processing unit 8 and the heating controller 12 are all electrically connected to the load instruction input unit via the adder 23 .

[0086] The load instruction input unit includes an electric load instruction input unit 10, a thermal load instruction input unit 11 and a pressure instruction input unit 24. The electric load instruction input unit 10 and the thermal load instruction input unit 11 are both electrically connected to the first processing unit 9. The electric load instruction input unit 10, the thermal load instruction input unit 11 and the pressure instruction input unit 24 are touch screens.

[0087] The first processing unit 9, the second processing unit 8, the boiler 1 controller 7 and the heating controller 12 are all PLC controllers.

[0088] The specific working process of the coordinated control system for regulating the electrical and thermal loads of the cogeneration unit is as follows:

[0089] The steam generated by the boiler 1 is transported to the high-pressure cylinder 16 of the steam turbine through the main steam regulating valve 20. The high-pressure cylinder 16 of the steam turbine compresses the steam into high pressure, and then heats it into high-temperature and high-pressure steam through the reheater 2 and transports it to the intermediate-pressure cylinder 17 of the steam turbine. The steam in the intermediate-pressure cylinder 17 of the steam turbine is transported to the heat network 22 through the steam supply regulating valve 21. The amount of steam entering the heat network can be adjusted by adjusting the low-pressure regulating valve 14, and the steam in the intermediate-pressure cylinder 17 of the steam turbine is transported to the low-pressure cylinder 18 of the steam turbine through the low-pressure regulating valve 14. The low-pressure cylinder 18 of the steam turbine rotates to drive the motor 13 to do work.

[0090] The steam discharged from the low-pressure cylinder 18 of the steam turbine after work is condensed into water through the condenser 19, and then the water is transported to the boiler 1 through the feed water pump 16 and the feed water control valve 3 to be evaporated into steam again.

[0091] The first processing unit 9 receives the heat load instruction, the electric load instruction and the pressure instruction, and compares them with the actual heat supply, the actual power generation and the actual steam pressure in the cogeneration unit, and obtains the corresponding heat load difference △Q, the electric load difference △N and the main steam pressure difference △P, and the heat load difference △Q, the electric load difference △N and the main steam pressure difference △P act on the second processing unit 8, the boiler controller 7 and the heating controller 12 respectively;

[0092] The boiler controller 7 adjusts the boiler fuel quantity B according to the boiler total load instruction G0 sent by the first processor 9. According to the boiler fuel quantity B, the belt conveyor 4, fan 5 and water pump 6 respectively adjust the coal delivery amount, air volume and water supply, and adjust the steam output of the boiler 1 in turn.

[0093] The second processing unit 8 issues a regulating instruction μ1 to the main steam regulating valve 20 to regulate the steam intake of the high-pressure cylinder 16 of the steam turbine according to the heat load difference △Q, the electric load difference △N and the main steam pressure difference △P;

[0094] The heating controller 12 issues a regulating instruction μ2 to adjust the opening of the low-pressure regulating valve 14 according to the heat load difference △Q, the electric load difference △N and the main steam pressure difference △P, thereby adjusting the heat supply entering the heating network.

[0095] The coordinated control system for a cogeneration generator set of the present invention aims to achieve an ideal regulation effect when the electrical load and the thermal load change respectively. The following describes two situations of electrical load change and thermal load change:

[0096] (1) Increased electrical load

[0097] When the electric load demand increases and the heat load remains unchanged, the electric and heat load instructions are transmitted to the main control system to calculate the total load instruction. The total load instruction is output to the boiler to increase the amount of fuel. This is a rapid adjustment of the load. Accurate total load instructions can ensure the boiler's rapid response to the load.

[0098] The boiler control system set value increases, and the boiler completes the secondary regulation of the boiler side according to the electric power difference △N, that is, completes the differential regulation of the electric power. However, due to the large delay and inertia of the boiler itself, there is a delay in the change of electric power on the boiler side. The solution of the present invention is to connect the electric power difference signal △N to the inlet of the steam turbine controller in a feedforward form. At this time, the inlet parameter of the steam turbine controller is △N+△P, and the main steam regulating valve opening is increased to complete the rapid response of the electric power.

[0099] Due to the thermoelectric coupling relationship, the increase of the electric power value N will lead to an increase in the flow rate of heating extraction steam, resulting in an increase in the heat load. The present invention uses the power difference signal △N to input the input of the heating controller in a feedforward form for compensation. The input signal of the heating controller is △Q-△N, that is, the opening of the low-pressure regulating valve is increased to ensure that the flow rate of heating extraction steam remains basically unchanged.

[0100] (2) Increased heat load

[0101] When the heat load demand increases and the electric load remains unchanged, the electric and heat load instructions are transmitted to the main control system to calculate the total load instruction. The total load instruction is output to the boiler to increase the amount of fuel. This is a rapid adjustment of the load. Accurate total load instructions can ensure the boiler's rapid response to the load.

[0102] The given value of the heating control system increases, and the opening of the low-pressure regulating valve is reduced according to the heat load difference △Q signal, so as to complete the differential regulation of the heat supply. At the same time, the heat load difference △Q is input to the boiler controller in the form of a feedforward signal, and the boiler controller inlet signal is △Q+△N, so as to realize the rapid response of the boiler to the load; in order to speed up the load rate of the transformer, the present invention adopts the form of inputting the heat load difference signal △Q into the inlet of the turbine controller in the form of a feedforward to compensate, that is, the inlet signal of the turbine controller is △Q+△P, and the main steam regulating valve opening is increased to complete the rapid regulation of the electric power.

[0103] The difference between the high-pressure cylinder, medium-pressure cylinder and low-pressure cylinder lies in the different internal pressures. In a steam turbine, they are generally connected to each other; the high-pressure cylinder is the initial stage for the main steam to enter the cylinder. At this time, the steam pressure is high and the temperature is high. The cylinder is the outer shell of the steam turbine. Its function is to separate the flow part of the steam turbine from the atmosphere, forming a closed steam chamber to ensure that the steam completes energy conversion inside the steam turbine.

[0104] The technical means disclosed in the scheme of the present invention are not limited to the technical means disclosed in the above-mentioned implementation mode, but also include technical schemes composed of any combination of the above-mentioned technical features. 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, and these improvements and modifications are also regarded as the protection scope of the present invention.

Claims

1. A coordinated control method for regulating the electrical and thermal loads of a cogeneration unit, characterized in that : S1): Setting a coordinated control system for controlling the cogeneration unit, the control system comprising a unit control system, a boiler control system and a heating steam control system; S2): Different controlled parameters are set in different control systems, and the controlled parameters are used as feedback adjustment quantities; at the same time, different adjustment signals are set in different control systems, and the adjustment signals are used as feedforward compensation quantities; S3): The unit control system calculates the total load command G0 according to the heat load and electric load commands, and at the same time, the unit control system adjusts the electric load of the cogeneration unit with the feedback adjustment amount and the feedforward compensation amount; S4): The boiler control system receives the total load instruction and calculates the first fuel adjustment amount of the boiler. At the same time, the boiler control system adjusts the second fuel adjustment amount of the boiler with the feedback adjustment amount and the feedforward compensation amount; S5): The heating steam control system adjusts the heat load of the cogeneration unit according to the feedback adjustment amount and the feedforward compensation amount; The unit control system stores a thermal operating diagram calculation loop and a turbine main steam valve calculation loop, wherein: The thermal operating diagram calculation loop calculates a total load instruction using a thermal load instruction and an electrical load instruction; The main steam valve operation loop of the steam turbine uses the heat load difference △Q and the electric power difference △N as the feedforward compensation amount, and at the same time uses the main steam pressure difference △P in the cogeneration unit as the controlled amount for feedback regulation to control the electric load regulation of the cogeneration unit; The heat load difference △Q is the difference between the actual load Q of the steam turbine exhaust heat supply in the cogeneration unit and the given value Q0 of the steam turbine exhaust heat supply load; The electric power difference △N is the actual power generation power N of the cogeneration unit. e The difference with the given value N0 of the power generation of the cogeneration unit; The main steam pressure difference △P is the actual steam pressure value P at the inlet of the steam turbine in the cogeneration unit. T The difference between the given value P0 of the steam pressure at the turbine inlet in the cogeneration unit.

2. The coordinated control method for regulating the electrical and thermal loads of a cogeneration unit according to claim 1, characterized in that: The coordinated control method is a machine and furnace coordinated control method.

3. The coordinated control method for regulating the electrical and thermal loads of a cogeneration unit according to claim 1, characterized in that: The thermal operating diagram calculation loop calculates the total load instruction G0 according to the load calculation function, and the load calculation function is: Where D is the total load, is the slope of the pure condensation condition line is the power generation, is a constant, and It's about heat supply The heat supply function is: ； in, is the heat supply; the heat supply function can be obtained through different groups ( , b) obtained by numerical fitting.

4. The coordinated control method for regulating the electrical and thermal loads of a cogeneration unit according to claim 1, characterized in that: The boiler control system stores a boiler command operation loop, which receives a total load command G0 and performs a primary adjustment of the boiler fuel quantity B according to the total load command G0; At the same time, the boiler command operation loop uses the heat load difference △Q and the main steam pressure difference △P as feedforward compensation, and uses the electric power difference △N as the controlled quantity for feedback adjustment to control the secondary adjustment of the boiler fuel quantity B.

5. The coordinated control method for regulating the electrical and thermal loads of a cogeneration unit according to claim 1, characterized in that: The heating steam control system stores a heating operation loop, which uses the electric power difference △N and the main steam pressure difference △P as feedforward compensation quantities, and at the same time uses the heat load difference △Q as the controlled quantity for feedback regulation to control the heat load regulation of the cogeneration unit.

6. A system comprising the coordinated control method for regulating the electrical and thermal loads of a cogeneration unit according to any one of claims 1 to 5, characterized in that: It includes a unit control system, a boiler control system, a heating steam control system and a cogeneration unit; wherein the unit control system includes a first processing unit, a second processing unit and a load instruction input unit, the boiler control system includes a boiler controller and a boiler adjustment unit, and the heating steam control system includes a heating controller, wherein the load instruction input unit is electrically connected to the first processing unit, the second processing unit and the boiler controller are electrically connected to the first processing unit, the boiler controller is electrically connected to the boiler adjustment unit, the boiler controller, the second processing unit and the heating controller are all electrically connected to the cogeneration unit, the boiler controller, the second processing unit and the heating controller are all provided with an adder, the second processing unit and the heating controller are both electrically connected to the first processing unit through the adder, and the boiler controller is electrically connected to the cogeneration unit through the adder.

7. The coordinated control system for regulating the electrical and thermal loads of a cogeneration unit according to claim 6, characterized in that: The cogeneration unit includes a boiler, a high-pressure cylinder of a steam turbine, an intermediate-pressure cylinder of a steam turbine, a low-pressure cylinder of a steam turbine and a generator. A main steam regulating valve is arranged between the boiler and the high-pressure cylinder of the steam turbine. The boiler is connected to the high-pressure cylinder pipeline of the steam turbine through the main steam regulating valve. A reheater is arranged in the boiler. The high-pressure cylinder of the steam turbine is connected to the intermediate-pressure cylinder pipeline of the steam turbine through the reheater. A steam supply regulating valve is arranged on the intermediate-pressure cylinder of the steam turbine. A low-pressure regulating valve is arranged on the low-pressure cylinder of the steam turbine. The intermediate-pressure cylinder of the steam turbine extracts steam through the steam supply regulating valve. The intermediate-pressure cylinder of the steam turbine is connected to the low-pressure cylinder pipeline of the steam turbine through the low-pressure regulating valve. The generator is rotatably connected to the low-pressure cylinder of the steam turbine. A condenser, a feedwater pump and a feedwater control valve are arranged between the low-pressure cylinder of the steam turbine and the boiler. The low-pressure cylinder of the steam turbine is connected to the boiler pipeline through the condenser, the feedwater pump and the feedwater control valve in sequence.

8. The coordinated control system for regulating the electrical and thermal loads of a cogeneration unit according to claim 7, characterized in that: The main steam regulating valve is electrically connected to the second processing unit, and the low-pressure regulating valve is electrically connected to the heating controller; The boiler is provided with a pipeline pressure sensor, the steam supply regulating valve is provided with a heat meter, and the generator is provided with an electric power sensor. The boiler controller, the second processing unit and the heating controller are all electrically connected to the pipeline pressure sensor via an adder; The boiler controller, the second processing unit and the heating controller are all electrically connected to the heat meter via an adder; The boiler controller, the second processing unit and the heating controller are all electrically connected to the pipeline electric power sensor through an adder. The boiler controller, the second processing unit and the heating controller are all electrically connected to the load instruction input unit via an adder.

9. The coordinated control system for regulating the electrical and thermal loads of a cogeneration unit according to claim 8, characterized in that: The load instruction input unit includes an electric load instruction input unit, a thermal load instruction input unit and a pressure instruction input unit. The electric load instruction input unit and the thermal load instruction input unit are both electrically connected to the first processing unit. The electric load instruction input unit, the thermal load instruction input unit and the pressure instruction input unit are touch screens.

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