A steam heating network energy storage assisted peak regulation control method, system, equipment and medium

Abstract

The present invention discloses a steam heat network energy storage assisted peak regulation control method, system, equipment and medium, which belong to the field of power generation. The specific operation is: dividing the load instruction into two parts: the unit power set value and the power increment set value. The nonlinear model of the heating extraction steam throttling system calculates the power increment estimated value, and the difference between the power increment set value and the power increment set value is used as the input value of the power increment control system for PID control; the input value in the original unit coordinated control is the unit power set value minus the unit power feedback value and the power increment estimated value. The present invention adopts the nonlinear model of the heating extraction steam throttling system to estimate the power increment caused by the heating extraction steam throttling, which is simple to measure and easy to operate; at the same time, by adjusting the heating extraction steam butterfly valve, the energy storage of the steam heat network is called upon, the operating flexibility of the unit is improved, and the peak regulation capacity of the unit is increased.

Description

Technical Field

[0001] The present invention belongs to the field of power generation and relates to a steam heating network energy storage assisted peak regulation control method, system, equipment and medium. Background Art

[0002] Cogeneration is a mature, energy-efficient technology for clean, efficient coal utilization. Cogeneration units utilize high-quality thermal energy first for electricity generation and then for heat generation, achieving cascaded energy utilization. Compared to traditional condensing units, cogeneration units effectively utilize a portion of the exhaust heat, significantly improving primary energy efficiency and reducing overall energy consumption.

[0003] With the rapid development of renewable energy sources such as solar and wind power, my country has become the world's largest and fastest-growing country in terms of renewable energy development. However, the increasing share of wind and photovoltaic power generation in my country has also brought with it many new challenges. The high volatility and anti-peaking characteristics of wind and photovoltaic power generation pose significant challenges to the grid's peak load regulation. In the coming years, continuous low-load operation or deep peak load regulation of thermal power units, especially coal-fired units, will become the norm.

[0004] In a cogeneration unit, a large amount of steam is stored in the steam heating network, and its energy storage capacity is large. However, it is difficult to effectively utilize the steam heating network in the existing technology, resulting in a waste of resources. Summary of the Invention

[0005] The purpose of the present invention is to overcome the shortcomings of the above-mentioned prior art that the steam energy storage capacity in the steam heating network is large and difficult to effectively utilize, thereby causing waste of resources, and to provide a steam heating network energy storage assisted peak regulation control method.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] A method for controlling energy storage-assisted peak load regulation in a steam heating network comprises the following steps:

[0008] Step 1) obtaining the operating data of the steam heating network;

[0009] Step 2) calculating the change in the heating extraction steam flow rate based on the operating data of the steam heating network;

[0010] Based on the variation of the heating extraction steam flow rate, a nonlinear model of the heating extraction steam throttling system in the steam heating network is established, and the power increment estimate of the steam heating network is obtained based on the nonlinear model.

[0011] Step 3) establishing a power increment generation loop based on the operating data of the steam heating network. The specific method of the power increment generation loop is as follows: the power that the steam heating network can bear is obtained from the current safety limit of the steam heating network, recorded as the power increment, and the power increment set value of the unit is obtained based on the power increment generation loop;

[0012] Step 4) regulating the power increment set value to be equal to the power increment estimated value;

[0013] Step 5) Based on the power increment estimate, the power set value of the unit and the real-time measured power feedback value of the unit, the input variables of the original boiler-turbine coordinated control system are calculated.

[0014] Preferably, the nonlinear model of the heating extraction steam throttling system is:

[0015] ΔN e =ΔG e ·(h j -h n ) (1)

[0016] In formula (1), ΔN e is the estimated power increment, kW; ΔG e is the change in heating extraction steam flow rate caused by the throttling of the heating regulating butterfly valve, kg / s; h j is the enthalpy of heating extraction steam, kJ / kg; h n is the exhaust enthalpy of the steam turbine, kJ / kg;

[0017] The change in heating extraction steam flow rate is:

[0018] ΔG e =K1·p ic u1 (2)

[0019] In formula (2), K1 is the valve gain coefficient, p ic is the exhaust pressure of the medium pressure cylinder, MPa; u1 is the valve opening, %.

[0020] Preferably, the setting value of the power increment is:

[0021]

[0022] In formula (3), is the set value of power increment, kW; ΔE is the stored energy called by the heating network during the load change process, kJ; t s is the adjustment time, s;

[0023] The maximum value of the stored energy used by the heating network during load change is:

[0024] ΔE m =G m ·(hj -h n ) (4)

[0025] In formula (4), ΔE m is the maximum energy storage called by the heating network during the load change process, kJ; G m The maximum heating extraction steam flow rate that can be utilized without affecting the heat user experience, kg / s.

[0026] Preferably, the regulation of step 4) is specifically:

[0027] Calculate the difference between the power increment estimated value and the power increment set value to obtain the power increment difference;

[0028] The power increment difference is used as the input variable of the power increment control system, and the power increment difference is made zero through the PID control method.

[0029] Preferably, the regulation of step 5) is specifically:

[0030] The difference between the computer group power feedback value and the power increment estimated value is used as the actual power of the original unit coordinated control system. The unit power setting value is subtracted from the actual power of the original unit coordinated control system, and the difference is made zero through the PID control method.

[0031] A steam heating network energy storage auxiliary peak regulation control system, comprising:

[0032] A data acquisition unit, used to acquire the operating data of the steam heating network;

[0033] The data processing unit interacts with the data acquisition unit, and calculates the change in the heating extraction steam flow rate based on the steam heating network operation data transmitted by the data acquisition unit, and further calculates the power increment estimated value and the power increment set value;

[0034] The power increment control unit interacts with the data processing unit, takes the power increment set value and the power increment estimated value as input variables of the power increment control unit, and controls the power increment set value to be equal to the power increment estimated value;

[0035] The original boiler coordination control unit interacts with the data processing unit, and calculates the input variables of the original boiler coordination control system based on the power increment estimate, the unit power setting value and the real-time measured unit power feedback value.

[0036] Preferably, the data processing unit further includes:

[0037] A nonlinear model building module is used to build a nonlinear model of the heating extraction steam throttling unit based on the change in the heating extraction steam flow rate, and obtain an estimated power increment value of the unit based on the nonlinear model;

[0038] The power increment generation loop establishment module is used to establish a power increment generation loop based on the operation data of the steam heat network, and obtain the power increment set value of the unit based on the power increment generation loop.

[0039] Preferably, a PID controller for regulation is provided inside the power increment control unit.

[0040] A terminal device includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the steps of the steam heating network energy storage assisted peak regulation control method are implemented.

[0041] A computer-readable storage medium stores a computer program, which, when executed by a processor, implements the steps of the steam thermal network energy storage assisted peak regulation control method.

[0042] The unit power control system is divided into two parts: the original boiler-turbine coordinated control system and the power increment control system; the power increment control system uses PID control to make the set value of the power increment equal to the estimated value. In this system, the power increment estimated value is obtained by the nonlinear model of the heating extraction steam throttling system, and the difference between the power increment set value obtained by the power increment generation loop is used as the input value of the power increment control system; the difference between the unit power feedback value and the power increment estimated value in the original boiler-turbine coordinated control system is the actual power of the boiler-turbine coordinated control system, and the difference between the actual power of the unit coordinated control system and the unit power set value is the input value of the original boiler-turbine coordinated control system.

[0043] Compared with the prior art, the present invention has the following beneficial effects:

[0044] The present invention discloses a steam heating network energy storage-assisted peak-shaving control method. This method utilizes the heating extraction steam butterfly valve to call upon the heating network energy storage, and couples this method with the original boiler coordinated control system. A joint control method based on the nonlinear model of the heating extraction steam throttling system is designed. This method utilizes the heating network energy storage to increase the unit's load variation rate and enhance the unit's peak-shaving capability while meeting the heating needs of heat users. The specific operation is as follows: The load command is divided into two parts: a unit power setpoint and a power increment setpoint. The nonlinear model of the heating extraction steam throttling system calculates an estimated power increment value, and the difference between the estimated power increment value and the power increment setpoint is used as the input value for the power increment control system for PID control. The input value in the original unit coordinated control is the unit power setpoint minus the unit power feedback value and the estimated power increment value. The present invention uses the nonlinear model of the heating extraction steam throttling system to estimate the power increment caused by heating extraction steam throttling, resulting in simple measurement and easy operation. Simultaneously, by adjusting the heating extraction steam butterfly valve, the steam heating network's energy storage is called upon, improving the unit's operational flexibility and increasing its peak-shaving capability.

[0045] The present invention also discloses a steam heating network energy storage assisted peak regulation control system. It includes a data acquisition unit for acquiring the operating data of the steam heating network; a data processing unit, based on the operating data of the steam heating network transmitted by the data acquisition unit, calculates the change in the heating extraction steam flow rate, and further calculates the power increment estimated value and the power increment set value; a power increment control unit, using the power increment set value and the power increment estimated value as input variables of the power increment control unit, and controlling the power increment set value to be equal to the power increment estimated value; an original boiler coordination control unit, using the power increment set value, the power increment estimated value and the preset power set value as input variables. During the load change process, the difference in response speed between the boiler side and the steam turbine side limits the peak regulation capacity of the unit. The power increment estimated value is obtained from the nonlinear model of the heating extraction steam throttling system, and the difference between the power increment estimated value and the power increment set value obtained by the power increment generation loop is used as the input value of the power increment control system. Through PID control, the power increment set value is made equal to the estimated value; the input value in the original boiler coordination control system is the difference between the power difference value and the power increment estimated value. The present invention utilizes the steam extraction butterfly valve to adjust and call the steam heat network energy storage, improves the load change rate of the unit, and enhances the peak regulation capability of the unit. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 This is a flow chart of the combined control method based on the nonlinear model of the heating extraction steam throttling system; DETAILED DESCRIPTION

[0047] The present invention is described in further detail below with reference to the accompanying drawings:

[0048] Example 1

[0049] A method for controlling energy storage-assisted peak load regulation in a steam heating network comprises the following steps:

[0050] Step 1) obtaining the operating data of the steam heating network;

[0051] Step 2) calculating the change in the heating extraction steam flow rate based on the operating data of the steam heating network;

[0052] Based on the variation of the heating extraction steam flow rate, a nonlinear model of the heating extraction steam throttling system in the steam heating network is established, and the power increment estimate of the steam heating network is obtained based on the nonlinear model.

[0053] Step 3) establishing a power increment generation loop based on the operating data of the steam heating network;

[0054] The specific method of the power increment generation loop is as follows: the power that the steam heating network can bear is obtained from the current safety limit of the steam heating network, which is recorded as the power increment. The power increment set value of the unit is obtained based on the power increment generation loop;

[0055] Step 4) regulating the power increment set value to be equal to the power increment estimated value;

[0056] Step 5) Based on the unit power set value, the power increment estimate and the real-time measured unit power feedback value, the input variables of the original unit coordinated control system are calculated.

[0057] Example 2

[0058] A steam heating network energy storage-assisted peak regulation control method comprises a unit power control system divided into two parts: a primary turbine and boiler coordinated control system and a power increment control system. The power increment control system uses PID control to ensure that the set value of the power increment is equal to the estimated value. In this system, the estimated power increment value is obtained by a nonlinear model of the heating extraction steam throttling system, and the difference between the estimated power increment value and the set power increment value obtained by the power increment generation loop serves as the input value of the power increment control system. The input value of the primary turbine and boiler coordinated control system is the difference between the power difference and the estimated power increment value.

[0059] The nonlinear model of the heating extraction steam throttling system is:

[0060] ΔN e =ΔG e ·(h j -h n ) (1)

[0061] In formula (1), ΔP es is the estimated power increment, kW; ΔG e is the change in heating extraction steam flow rate caused by the throttling of the heating regulating butterfly valve, kg / s; h j is the enthalpy of heating extraction steam, kJ / kg; h n is the exhaust enthalpy of the steam turbine, kJ / kg;

[0062] The change in heating extraction steam flow rate caused by the throttling of the heating regulating butterfly valve is calculated as:

[0063] ΔG e =K1·p ic u1 (2)

[0064] In formula (2), K1 is the valve gain coefficient, p ic is the exhaust pressure of the intermediate pressure cylinder, MPa; u1 is the valve opening, %; the setting value of the power increment is:

[0065]

[0066] In formula (3), is the set value of power increment, kW; ΔE is the stored energy called by the heating network during the load change process, kJ; t s is the adjustment time, s;

[0067] The maximum value of the stored energy used by the heating network during load change is:

[0068] ΔE m =G m ·(h j -h n ) (4)

[0069] Where, ΔE m is the maximum energy storage called by the heating network during the load change process, kJ; G m The maximum heating extraction steam flow rate that can be utilized without affecting the heat user experience, kg / s;

[0070] Unit power control system such as Figure 1 As shown:

[0071] Divide the load command into the unit power set value and power increment setting value Calculate the power increment estimate ΔN based on the nonlinear model of the heating extraction steam throttling system e , and the power increment setting value The difference is used as the input value of the power increment control system; the input value in the original unit coordinated control is the unit power setting value Subtract the unit power feedback value ΔN e Add the estimated power increase ΔN e .

[0072] Example 3

[0073] Except for the following contents, the rest are the same as those in Example 1.

[0074] The regulation of step 4) is specifically as follows:

[0075] Calculate the difference between the power increment estimated value and the power increment set value to obtain the power increment difference;

[0076] The power increment difference is used as the input variable of the power increment control system, and the power increment difference is made zero through the PID control method.

[0077] The regulation of step 5) is specifically as follows:

[0078] The difference between the computer group power feedback value and the power increment estimated value is used as the actual power of the original unit coordinated control system. The unit power setting value is subtracted from the actual power of the original unit coordinated control system, and the difference is made zero through the PID control method.

[0079] Example 4

[0080] A steam heating network energy storage auxiliary peak regulation control system, comprising:

[0081] A data acquisition unit, used to acquire the operating data of the steam heating network;

[0082] The data processing unit interacts with the data acquisition unit, and calculates the change in the heating extraction steam flow rate based on the steam heating network operation data transmitted by the data acquisition unit, and further calculates the power increment estimated value and the power increment set value;

[0083] The power increment control unit interacts with the data processing unit, takes the power increment set value and the power increment estimated value as input variables of the power increment control unit, and controls the power increment set value to be equal to the power increment estimated value;

[0084] The original boiler coordination control unit interacts with the data processing unit and takes the power increment set value, the power increment estimated value and the preset power set value as input variables.

[0085] The data processing unit also includes:

[0086] A nonlinear model building module is used to build a nonlinear model of the heating extraction steam throttling unit based on the change in the heating extraction steam flow rate, and obtain an estimated power increment value of the unit based on the nonlinear model;

[0087] The power increment generation circuit establishment module is used to establish the power increment generation circuit based on the operation data of the steam heating network, and obtain the power increment set value of the unit based on the power increment generation circuit

[0088] It should be noted that, in the above embodiment, a PID controller for regulation is provided inside the power increment control unit.

[0089] Example 5

[0090] If the method of the present invention is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the present invention can implement all or part of the processes in the above-mentioned embodiment method, and can also be completed by a computer program to instruct the relevant hardware. The computer program can be stored in a computer-readable storage medium. When the computer program is executed by a processor, it can implement the steps of each of the above-mentioned method embodiments. The computer program includes computer program code, which can be in source code form, object code form, executable file or some intermediate form. Computer-readable storage media include permanent and non-permanent, removable and non-removable media, and can use any method or technology to implement information storage. The information can be computer-readable instructions, data structures, program modules or other data. It should be noted that the content contained in the computer-readable medium can be appropriately increased or decreased according to the requirements of legislation and patent practice in the jurisdiction. For example, in some jurisdictions, according to legislation and patent practice, computer-readable media does not include electric carrier signals and telecommunication signals. Among them, the computer storage medium can be any available medium or data storage device that can be accessed by the computer, including but not limited to magnetic storage (such as floppy disks, hard disks, magnetic tapes, magneto-optical disks (MO)), optical storage (such as CDs, DVDs, BDs, HVDs, etc.), and semiconductor storage (such as ROM, EPROM, EEPROM, non-volatile memory (NANDFLASH), solid-state drives (SSDs)), etc.

[0091] Example 6

[0092] Also provided is a computer device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the steps of the method of the present invention when executing the computer program. The processor may be a central processing unit (CPU), or may be another general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), an off-the-shelf programmable gate array (FPGA), or other programmable logic device, discrete gate or transistor logic device, discrete hardware component, or the like.

[0093] In summary, considering that changing the opening of the steam extraction butterfly valve can quickly utilize the thermal network energy storage, and the heat users are difficult to detect the change in heating load caused by the utilization of the thermal network energy storage in a short period of time. Therefore, using steam thermal network energy storage to assist in peak regulation is an important means of regulation for thermal power units. Steam thermal network energy storage has the advantages of large capacity and fast response speed, and can be used to make up for the energy gap of the machine and boiler caused by the slow response speed on the boiler side. Power control is divided into two parts: the original machine and boiler coordinated control system and the power increment control system. The control strategy of the method of the present invention enhances the peak regulation capacity of the unit by calling the steam thermal network energy storage with large capacity and fast adjustment speed during the load change process.

[0094] The above content is only for explaining the technical idea of ​​the present invention and cannot be used to limit the protection scope of the present invention. Any changes made on the basis of the technical solution in accordance with the technical idea proposed by the present invention shall fall within the protection scope of the claims of the present invention.

Claims

1. A steam heating network energy storage assisted peak regulation control method, characterized in that: The following steps are involved: Step 1) Obtaining the operating data of the steam heating network; Step 2) Based on the operating data of the steam heating network, the change in the heating extraction steam flow rate is calculated; Based on the change in the heating extraction steam flow rate, a nonlinear model of the heating extraction steam throttling system in the steam heating network is established. Based on the nonlinear model, the power increment estimate of the steam heating network is obtained. The nonlinear model of the heating extraction steam throttling system is: ， in, is the estimated power increment, kW; is the change in heating extraction steam flow rate caused by the throttling of the heating regulating butterfly valve, kg / s; h j is the enthalpy of heating extraction steam, kJ / kg; h n is the exhaust enthalpy of the steam turbine, kJ / kg; The setting value of power increment is: ， in, is the set value of power increment, kW; is the stored energy called up by the heating network during load variation, kJ; t s is the adjustment time, s; Step 3) Establishing a power increment generation loop based on the steam heating network's operating data. The specific method of the power increment generation loop is as follows: The power that the steam heating network can bear is obtained from the current safety limit of the steam heating network, recorded as the power increment, and the power increment set value of the unit is obtained based on the power increment generation loop; Step 4) adjusting the power increment set value to be equal to the power increment estimated value; Step 5) Based on the power increment estimate, the unit power setpoint, and the real-time measured unit power feedback value, the input variables of the original boiler-turbine coordinated control system are calculated. The control is specifically as follows: Calculate the difference between the unit power feedback value and the power increment estimate in the original boiler-turbine coordinated control system, use this difference as the actual power output of the original boiler-turbine coordinated control system, subtract the unit power setting value from the actual power output of the original boiler-turbine coordinated control system, and use the PID control method to make the difference between the unit power setting value and the actual power output of the original boiler-turbine coordinated control system zero; The heat network energy storage is called upon by adjusting the heat extraction steam butterfly valve, and is coupled with the original boiler coordinated control system.

2. The steam heating network energy storage assisted peak regulation control method according to claim 1, characterized in that: The specific regulation of step 4) is as follows: Calculate the difference between the power increment estimated value and the power increment set value to obtain the power increment difference; The power increment difference is used as the input variable of the power increment control system, and the power increment difference is made zero through the PID control method.

3. A steam heating network energy storage assisted peak shaving control system, based on the steam heating network energy storage assisted peak shaving control method according to claim 1, characterized in that: include: A data acquisition unit, used to acquire the operating data of the steam heating network; The data processing unit interacts with the data acquisition unit, and calculates the change in the heating extraction steam flow rate based on the steam heating network operation data transmitted by the data acquisition unit, and further calculates the power increment estimated value and the power increment set value; The power increment control unit interacts with the data processing unit, takes the power increment set value and the power increment estimated value as input variables of the power increment control unit, and controls the power increment set value to be equal to the power increment estimated value; The original boiler coordination control unit interacts with the data processing unit, and calculates the input variables of the original boiler coordination control system based on the power increment estimate, the unit power setting value and the real-time measured unit power feedback value.

4. The steam heating network energy storage auxiliary peak regulation control system according to claim 3 is characterized in that: The data processing unit also includes: A nonlinear model building module is used to build a nonlinear model of the heating extraction steam throttling unit based on the change in the heating extraction steam flow rate, and obtain an estimated power increment value of the unit based on the nonlinear model; The power increment generation loop establishment module is used to establish a power increment generation loop based on the operation data of the steam heat network, and obtain the power increment set value of the unit based on the power increment generation loop.

5. The steam heating network energy storage auxiliary peak regulation control system according to claim 3 is characterized in that: A PID controller for regulation is provided inside the power increment control unit.

6. A terminal device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein: When the processor executes the computer program, the steps of the steam thermal network energy storage assisted peak regulation control method according to any one of claims 1 to 2 are implemented.

7. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the steps of the steam thermal network energy storage assisted peak regulation control method according to any one of claims 1 to 2 are implemented.

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