JP4285068B2 - Power plant, power plant control method, and plant control information providing method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a power plant, a power plant control method, and a plant control information providing method.
[0002]
[Prior art]
In a plant in which steam is generated by a boiler and the turbine is rotated, a boiler and a turbine are often used as a unit, and a plurality of such units are installed. In this case, steam generated in the boiler is connected by a connecting pipe, and the steam of the boiler is distributed and operated so as to minimize fuel consumption as a whole plant in consideration of the characteristics of each boiler and turbine.
[0003]
For example, for each supply steam flow from the boiler, the steam distribution to each turbine is determined so that the total output of each turbine is maximized, and the fuel used in each boiler is fuel with good controllability and fuel efficiency. There is known a technique for determining the steam distribution amount of each boiler so that the sum of the steam amounts by pressure is generated at a minimum cost when the steam generated by each fuel is low pressure steam and high pressure steam. This technique is described in, for example, JP-A-8-95604.
[0004]
[Patent Document 1]
Japanese Patent Laid-Open No. 8-95604
[Problems to be solved by the invention]
In the prior art, the plant is controlled on the assumption that the fuel-steam amount relationship is substantially flat with respect to the boiler characteristics. However, in reality, since the power plant is composed of a large number of devices and has a complicated structure, the actual characteristics of the plant do not completely satisfy the design value. In addition, the furnace wall is soiled, and the equipment has been aging due to longer years and the equipment has been modified accordingly. For this reason, boiler efficiency changes every moment. That is, in the above-described conventional technology, changes in boiler efficiency over time are not taken into consideration.
[0006]
An object of the present invention is to provide a power plant, a power plant control method, and a plant control information providing method capable of improving plant efficiency in consideration of changes in boiler efficiency over time.
[0007]
More specifically, an object of the present invention is to provide an operation method capable of shortening the response time to a load request from a central power station or a customer for the purpose of improving the operability of the plant as a whole.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, in the present invention, the boiler efficiency, which is the steam generation efficiency that changes over time with respect to the fuel that has been added, is obtained based on information on the state of each of the plurality of boilers. Thus, the load operation command that defines the steam generation amount of each boiler and the steam operation command that defines the distribution of the generated steam to each turbine are calculated.
[0009]
Alternatively, it is configured as follows. A plurality of boilers that generate heat (steam) by burning fuel, a plurality of turbines that convert the steam generated from the boiler into rotational energy, and the rotational energy obtained from the turbine to electric power Steam / load operation command to each unit so that the total efficiency of the plant is maximized for a plant consisting of multiple generators that convert the system and a main steam / reheat steam connecting pipe connecting each unit And a method for calculating the boiler efficiency from the degree of fouling of the furnace, the fuel used, etc. in the maximum efficiency calculation, and providing a load command to each unit as a service.
[0010]
In addition, as a service, we provide an operation method that shortens the load request response time by extinguishing one or more boilers and starting two or more turbines for maximum efficiency operation.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
As an embodiment of the present invention, not only the request from the central power station but also the development to the power retail brokerage business is targeted, so the case where the power generation company supplies power to consumers will be described below. .
[0012]
An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing the development of the present invention in a power retail brokerage business. There is a service company 1, a power generation company 2, and a customer 3. A flow until power is supplied will be described. First, a power request 8 from the customer 3 enters the service company 1 via the network 4. Then, the service company 1 performs calculation for optimal operation with respect to the power demand 8 from the information 6 such as the plant operating status and plant characteristics of the power generation company 2, and gives the steam / load operation instruction 5 to the power generation company 2. Electric power 7 generated based on the command is sent to the customer 3.
[0013]
FIG. 2 is a diagram showing a configuration diagram of a plant that is an object of the present invention and a relationship with a service company that outputs a steam / load operation command to each unit of the plant. According to the configuration shown in FIG. 2, there are three units A, B, and C. Here, since each unit has the same configuration, the configuration of unit A will be described. The basic configuration and effect of the present invention are not limited to this, but are general regardless of the number of units.
[0014]
The unit A is for reheating the steam generated from the high pressure part of the turbine A17 and the main steam pipe A21 for sending the steam generated in the boiler A16, the turbine A17, the generator A18, the boiler A16 to the high pressure part of the turbine A17. A reheat steam pipe A22 for exchanging steam with the boiler A16, a main steam communication pipe 14 that connects the main steam pipes between the units, and a reheat steam communication that connects the reheat steam pipes between the units. The main steam communication pipe control valve A19 having the function of a control valve or a shutoff valve for adjusting the exchange of the main steam flow rate between the pipe 15, the main steam pipe A21 and the main steam communication pipe 14, as well as the reheat steam pipe A22 and the reheat The steam communication pipe 15 includes a reheat steam communication pipe control valve A20 that adjusts the exchange of reheat steam flow rate. The above is the configuration of unit A.
[0015]
Then, there is a unit A control device 11 for controlling the unit A, and the service company 1 receives plant information 6 such as a process amount and a characteristic value inside the boiler / turbine from each unit control device, and performs steam / load operation to each unit control device. Command 5 is output.
[0016]
Next, a specific service providing method performed by the service company will be described with reference to the block diagram of FIG. FIG. 3 is a diagram showing the exchange of information among the three parties of the customer 3, the service company 1, and the power generation company 2. The contents of the service provided by the service company 1 are a power supply plan 53, a physical model 54, an optimum load distribution calculation 55, a boiler efficiency calculation 56, a contamination degree calculation 57, boiler information 6a, turbine information 6b, a load operation command 5a, and steam operation. It consists of command 5b.
[0017]
A customer plan 52 showing a temporal variation in the amount of electricity demand from a plurality of consumers 51, that is, a power request enters the service company 1, and the power supply plan 53 can respond to a power request from the plurality of consumers 51. A power supply plan is generated so that the power generation company 2 can obtain electric power that can be produced at a minimum cost.
[0018]
In the optimum load distribution calculation 55, based on the constraint condition at that time given by the power supply plan 53, the process state quantity and the like are determined for each unit according to the boiler information 6a and the turbine information 6b, such as the boiler and turbine in the power plant. The optimum load distribution for a plurality of power generation elements is automatically calculated.
[0019]
In this case, information related to heat exchange in the boilers (boiler A16, boiler B23, boiler C30) from various measuring instruments inside the boiler from the boiler information 6a (for example, main feed water flow rate, boiler inlet steam temperature / pressure, boiler outlet Steam temperature / pressure fuel type, fuel consumption, fuel heating value, etc.) and the respective physical models 54 of the power generation elements of each boiler (boiler A16, boiler B23, boiler C30) The current boiler operating state such as calculating the degree of contamination of the heat exchanger of (boiler A16, boiler B23, boiler C30), and what load level the boiler is in the boiler efficiency calculation 56 and what fuel is used. The boiler efficiency is determined from the heat exchange performed inside the furnace. Using the boiler efficiency obtained in this way, the steam distribution amount that maximizes the total power generated by each turbine / generator and the total steam amount used by each turbine / generator are assigned to each boiler. The optimal load distribution calculation 55 calculates how to distribute the load.
[0020]
In accordance with the optimum load distribution calculated in this way, a load operation command 5a and a steam operation command 5b for instructing the distribution amount of steam generated from each boiler are sent to each unit, and each unit of the power generation company 2 You can drive economically. The load operation command 5a is the amount of steam produced by each boiler (boiler A16, boiler B23, boiler C30), that is, each fuel supply amount. Further, the load operation command 5 a includes a command for opening degrees of the reheat steam communication pipe control valves A, B, C 20, 27, 34 of the reheat steam communication pipe 15.
[0021]
Further, the steam operation command 5b indicates whether steam generated in the boiler (boiler A16, boiler B23, boiler C30) is distributed to the turbine (turbine A17, turbine B24, turbine C31). It includes commands for opening the main steam communication pipe control valves A, B, C 19, 26, 33 of the pipe 14.
[0022]
Thus, an economic effect can be obtained by performing a service in which the service company outputs an optimal operation command to the power plant in consideration of power generation factors that change every moment such as boiler efficiency.
[0023]
Next, an operation method for shortening the load request response time by extinguishing one or more boilers and starting two or more turbines will be described with reference to FIG. For ease of explanation, the following plant conditions are assumed. It is assumed that the fuel used in each boiler is different, that unit A is operated with oil as fuel, unit B is operated with coal as fuel, and unit C is operated with gas as fuel. Each unit has a rated load of 100 MW and does not consider a decrease in boiler efficiency due to fouling of the furnace.
[0024]
In the case where it is necessary to operate at a time when the power demand is small such as at night, it is assumed that there is a request of 30 MW (30% load) as the total power generation amount. In this case, the service company 1 receives information related to heat exchange from various measuring instruments inside the boiler (for example, main feed water flow rate, boiler inlet steam temperature / pressure, boiler outlet steam temperature / pressure fuel type, fuel consumption, The heat exchanger fouling degree is obtained by a fouling degree calculation 57 based on the physical model 54 of the power generation element and the power generation element, and the boiler efficiency is determined to be the same by the boiler efficiency calculation 56. A command is output so that one unit operation by unit B using the cheapest coal is performed.
[0025]
However, here, not all the 30% load steam generated by the boiler B23 is sent to the turbine B24, but the service company 1 sends only 15% load, which is half of the steam generated to the turbine B24, and the remaining 15%. Is sent to the turbine A17 to give a steam / load operation command 5 that generates 15 MW to the unit A control device 11 and the unit B control device 12 to perform the operation. Here, the steam generated in the boiler B23 is divided into two turbines. However, since the purpose is to bring both turbines into operation, the distribution ratio is arbitrary.
[0026]
It is assumed that the total power generation request to the plant has increased from 30 MW to 150 MW from this state. That is, steam for one boiler or more must be generated, and the service company 1 determines that the boiler B23 generates steam for 100 MW and the boiler A16 generates steam for 50 MW.
[0027]
Here, the load of the boiler A16 increases while coordinating with the turbine A17. However, since the turbine A17 is already in operation, it does not require time until the turbine A17 is started, and when the boiler A16 is started. The load can be increased in a shorter time since there is no restriction on the temperature condition of the turbine A17. During this time, the boiler B23 is increased to the rated load, and accordingly the turbine A17 is operated by receiving steam up to 50% load. And as soon as boiler A16 becomes more than the minimum load condition, turbine A17 receives the steam from boiler A16, and the steam of boiler B23 increases distribution amount to turbine B24 simultaneously.
[0028]
Therefore, according to the present invention, the rise time of the fired boiler is shortened by extinguishing one or more boilers and starting two or more turbines. Response time for requests can be shortened.
[0029]
In this way, in response to commands from customers and central power stations, economically optimal load / steam operation commands that take into account changes in boiler efficiency calculated from process values and characteristic values inside the plant are output to the plant. Can provide services. In addition, extinguishing one or more boilers and starting two or more turbines shortens the rise time of the fired boiler, shortening the response time to load requests from customers and central power stations I can do it.
[0030]
【The invention's effect】
As described above, according to the present invention, it is possible to improve plant efficiency in consideration of changes in boiler efficiency over time.
[Brief description of the drawings]
FIG. 1 is a diagram showing development into a power retail brokerage business.
FIG. 2 is a diagram illustrating a relationship between a plant configuration diagram and a service company.
FIG. 3 is a block diagram showing a configuration of a power plant optimal operation method control apparatus.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Service company, 2 ... Power generation company, 3 ... Consumer, 4 ... Network, 5 ... Steam / load operation command, 5a ... Load operation command, 5b ... Steam operation command, 6 ... Plant information, 6a ... Boiler information, 6b ... turbine information, 7 ... electric power, 8 ... electric power demand, 11 ... unit A control device, 12 ... unit B control device, 13 ... unit C control device, 14 ... main steam communication pipe, 15 ... reheat steam communication pipe, 16 ... Boiler A, 17 ... Turbine A, 18 ... Generator A, 19 ... Main steam communication pipe control valve A, 20 ... Reheat steam communication pipe control valve A, 21 ... Main steam pipe A, 22 ... Reheat steam pipe A , 23 ... Boiler B, 24 ... Turbine B, 25 ... Generator B, 26 ... Main steam communication pipe control valve B, 27 ... Reheat steam communication pipe control valve B, 28 ... Main steam pipe B, 29 ... Reheat steam Pipe B, 30 ... Boiler C, 31 ... Turbine C, 32 ... Generator C 33 ... Main steam communication pipe control valve C, 34 ... Reheat steam communication pipe control valve C, 35 ... Main steam pipe C, 36 ... Reheat steam pipe C, 51 ... Consumer, 52 ... Customer plan, 53 ... Electric power Supply plan, 54 ... physical model, 55 ... optimum load distribution plan, 56 ... boiler efficiency calculation, 57 ... dirtness calculation.

Claims (7)

  A plurality of boilers, a plurality of turbines to which steam generated in the plurality of boilers is distributed, a plurality of generators respectively coupled to the plurality of turbines, and determining each state of the plurality of boilers; Based on this, the boiler efficiency, which is the steam generation efficiency that changes over time with respect to the injected fuel, is obtained, and based on the boiler efficiency, a load operation instruction that defines the steam generation amount of each boiler and generated A control device that generates a steam operation command defining distribution of steam to each turbine, wherein the plurality of boilers and the plurality of turbines are controlled based on the load operation command and the steam operation command. Power plant.   The main steam pipe for supplying steam from the plurality of boilers to the plurality of turbines, a communication pipe connecting the plurality of main steam pipes to each other, and a communication valve provided in the communication pipe. The communication valve is controlled based on the steam operation command.   The power plant according to claim 1 or 2, wherein the load operation command and the steam operation command are output in a direction in which power generation efficiency is improved.   4. The power plant according to claim 3, wherein the boiler efficiency is obtained from a degree of contamination of the boiler or fuel used, and the load operation command and the steam operation command are output in a direction to improve the boiler efficiency.   Based on the information on the state of each of the plurality of boilers, the boiler efficiency, which is the steam generation efficiency that changes with time, is calculated for the input fuel, and the steam generation amount of each boiler is defined based on the boiler efficiency. A power plant control method for controlling a power plant by calculating a load operation command and a steam operation command defining distribution of generated steam to each turbine.   Information on the state of each of the plurality of boilers is received via a communication line, and based on this, the boiler efficiency, which is the steam generation efficiency that changes over time with respect to the injected fuel, is obtained, and based on the boiler efficiency , A load operation command that defines the steam generation amount of each boiler, and a steam operation command that defines the distribution of the generated steam to each turbine, and transmits the calculation result via a communication line. How to provide.   7. The method for providing plant control information according to claim 6, wherein the steam operation command is transmitted through a communication line as a control command provided in a communication pipe that connects the steam pipes to each other and controls the communication valve.

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