JPS60128831A - Method and device for distributing power - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a power supply distribution method and a power supply distribution device according to power demand, and in particular, to a method for maintaining highly economical nuclear power generation at a high operating rate. Power supply amount (3) Regarding component force method and power supply distribution device.

[Technical background of the invention and its problems]

Power generation facilities in Japan are mainly divided into nuclear power generation, hydroelectric power generation, and thermal power generation, and these power generation facilities are appropriately combined to generate commercial paper power in response to electricity demand. Among these, nuclear power generation has low fuel costs and is highly economical, but it has the problem of being limited by the fluctuation range of reactor output and fluctuation speed control.

Although the fuel cost of hydroelectric power generation is almost the same, it has the disadvantage that hydropower is influenced by natural phenomena.Furthermore, thermal power generation has high fuel costs, but has the advantage of being able to easily fluctuate its output. Therefore, nuclear power generation, hydroelectric power generation, and thermal power generation are appropriately combined to meet the actual power Wl.

On the other hand, the daily electricity demand is not necessarily unique;
fluctuate. In reality, the power demand cycle is such that daytime power demand is high from morning to evening, decreases from evening to night, and gradually increases from night to morning.

For this reason, the power supply from each power plant is distributed through so-called AFC operation (4), which automatically compensates for frequency fluctuations due to fluctuations in power demand. This AFC operation is actually performed by controlling the output operation from the thermal power plant.

By the way, the boiling water reactor (B
WR), slow neutrons are uranium-235 (U235
) reacts violently with nuclear fission and generates reactor power.

At that time, nuclear fission generates high-speed neutrons, but these fast neutrons collide with the lacrimal material (water) and slow down, changing into low-speed neutrons that easily react with U235.

In a boiling water reactor, water is used as a coolant, and this coolant receives the heat of the nuclear reaction and boils into steam, which drives a steam turbine to rotate a generator and generate the necessary electricity. I'm letting you do it.

The reactor output of a boiling water reactor is varied by adjusting the amount of steam generated (the amount of bubbles generated).

In practice this is done by adjusting the pump speed of the recirculation pump. That is, as the pump speed of the recirculation pump increases, the coolant flow rate increases and the amount of steam (bubbles) generated decreases. Contrary to this decrease in the amount of generated steam, the amount of liquid water increases.

For this reason, fast neutrons collide with water a lot and their speed tends to slow down, increasing the amount of slow neutrons. As the number of slow neutrons increases, reactions with U2 increase, nuclear fission progresses, and reactor power increases.

Decreasing the pump speed of the recirculation pump will reduce the coolant flow rate and, contrary to what was discussed above, reduce the furnace power.

In addition, in a boiling water reactor, it is possible to reduce the reactor output in a short period of time, but when increasing the reactor output rapidly, fuel is consumed rapidly, so it takes time to increase the reactor output. subject to restrictions.

In fact, the short-term (approximately 1 hour) increase in reactor output due to control rod withdrawal is limited to approximately 70% of the maximum output, and beyond that, output is increased by controlling the pump speed of the recirculation pump. , this output increase is limited to about 90% or less of the maximum output (rated output). Further, it is desirable that the adjustment of the reactor power from 909b to the maximum power of 100b be carried out over an extended period of time while slightly increasing the pump speed of the recirculation pump.

By the way, in the daily load operation of a boiling water reactor, assuming that it is operated at 50% of the rated output for 7 hours and then operated at the rated output for the rest of the day, the daily operating rate is 85 cm. In addition, after a nuclear reactor has been in operation for 12 months, there is a three-month suspension period for maintenance and inspection, so even if the reactor is operated at an operating rate of 85 degrees per day, the operation will be suspended. Considering the period, this becomes the actual operating rate. Considering power generation costs, it is desirable to operate at or above this operating rate.

For this reason, in order to maximize the economic efficiency of nuclear power generation (low fuel costs) without compromising the soundness of nuclear power generation, and to reduce the overall total power generation cost, it is necessary to The problem has been how to determine the operating ratio of each type of power generation, such as thermal power generation, in daily load operation.

[Purpose of the invention]

The present invention takes the above-mentioned points into consideration, and provides a power distribution method and a power distribution device that utilize nuclear power generation as effectively as possible during daily load operation and reduce total power generation costs without impairing the soundness of nuclear power generation. The purpose is to

[Summary of the invention]

In order to achieve the above-mentioned purpose, the power supply distribution method according to the invention of the first examination of this case roughly divides power generation equipment into nuclear power generation equipment, regular power generation equipment other than nuclear power generation facilities, and standby power generation equipment such as aging thermal power generation facilities. At the same time, the power supply period for daily load operation is divided into several parts based on the predicted power demand, and at each division step, a power supply command that proactively increases the operating rate of the nuclear power generation equipment is sent from the computing device to each power generation equipment. This is a method of adjusting and distributing the amount of power supplied from each power generation facility.

In addition, in order to achieve the above-mentioned purpose, the power supply distribution device according to the second invention of the present invention is designed to separate each power generation facility from nuclear power generation facilities, regular power generation facilities other than nuclear power generation facilities, and standby power generation facilities such as old thermal power generation facilities. It also consists of a transmitter/receiver that exchanges information between each power generation facility and the central control center, and a calculation device that issues power supply commands to adjust the distribution of the amount of power supplied from each power generation facility according to the predicted power demand. The arithmetic unit is configured to transmit a power feeding command that preferentially increases the operating rate of the nuclear power generation equipment to each power generation equipment via a transmitter/receiver, thereby causing each power generation equipment to operate.

[Embodiments of the invention]

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings.

As shown in FIG. 1, this invention provides power generation equipment as nuclear power generation equipment (hereinafter referred to as a nuclear power plant) 1.1...
and regular power generation facilities such as thermal power plants excluding nuclear power generation2
．． 2... and standby power generation facilities 3,3... such as hydroelectric power generation and aging thermal power plants.
... are ranked in advance, and which standby power generation facilities 3, 3,
It is determined whether to be used preferentially.

On the other hand, each power generation equipment 1, 1...; 2.2...; 3, 3
... are connected to a transceiver 5 which performs all information exchange with the central control center 4 regarding power. The transmitter/receiver 5 is connected in an input/output manner to an arithmetic unit 6 which determines the burden ratio of the supplied power (power distribution) and issues a power supply instruction. This arithmetic unit 6 also outputs an output to an image display 7 that displays the amount of electricity demanded and the amount of electricity supplied.The image display 7 displays the amount of electricity demanded and the amount of electricity supplied as an image for the operator to confirm. is now possible.

Therefore, each power generation equipment 1.1...:2,2...:3
The transmitter/receiver 5 is made to receive the power value (amount) that can be supplied from ゜3... for each power generation facility, and input into the arithmetic unit 6. Specifically, (,) the maximum supplyable power value is received from the nuclear power plant 1.1 and inputted into the calculation device 6, and (b) the minimum supplyable power value is also input into the calculation device 6. let Here, the minimum supplyable power value (amount) is the output value achieved when the pump speed of the recirculation pump of a boiling water reactor (BWR) is minimized and the reactor power pipe is lowered, and is usually the maximum The amount of power that can be supplied (rated output) is approximately 50 inches.

Further, the transmitter/receiver 5 receives a power generation value that can be increased in a short time (approximately 1 hour) from the (,) partial power generation value of each nuclear power plant 1.1..., and inputs it to the arithmetic unit 6. , (d) receive the output increase rate from the partially generated power value to the maximum supplied power value (rated output), and the arithmetic unit 6
Let it be input.

Here, the partial generated power value refers to the generated power value at an arbitrary position between the maximum value and the minimum value of the rated output by adjusting the pump speed of the recirculation pump of the nuclear reactor. If it is attempted to increase the amount of supplied power from this partially generated power value by increasing the pump speed of the recirculation pump, there will be restrictions due to the characteristics of the nuclear reactor. It takes a short time (approximately 1
Until the output exceeds 49.90% and reaches the rated output operation, it is necessary to operate for a long time with a gradual upward curve.

In addition, from regular power generation facilities 2, 2, etc. such as thermal power generation (including hydroelectric power generation) excluding nuclear power generation, do the same (,)
Maximum supplyable power value, (b) Minimum supplyable power value, (C
) The transmitter/receiver 5 receives the power supply rising speed and inputs it into the arithmetic unit 6 in advance.

In addition, standby power generation facilities such as aging thermal power generation and hydropower generation 3.
In 3..., each power generation facility 3, 3... is ranked in advance, and after determining the priority order of use, as in the case of regular power generation facilities, (a) maximum supplyable power value (b) The minimum supplyable power value (c) and the rate of increase in power supply are input to the arithmetic unit 6 via the transceiver 5. In this case, the minimum supplyable power value input to the arithmetic device 6 is zero.

Incidentally, the actual power demand changes as shown by 'power demand curve A' in FIG. This power demand curve A changes depending on spring, summer, fall, winter, and day of the week, and is not unambiguous. As shown in the power demand curve A, the demand for electricity is divided into the following periods: during the day from morning to evening when demand is high, from evening to night when electricity demand decreases, and from night to early morning. It can be broadly divided into periods of increasing volume. As the power demand changes, the daily power demand cycle is divided into, for example, four power supply steps.

(D The first power supply step is for a period of high power demand, and is a power supply method from 14:00 to time t8, for example, 6:00 in the evening.During this period, the power generation cost is low and it is not economical. The amount of power supplied from excellent nuclear power plants 1.1... is set to the maximum, and fluctuations in power demand are adjusted by power supply by AFC operation of standby power generation facilities 3.3... During this period. In response to a significant decrease in power demand, a command is given to regular power generation facilities 2, 2, etc. other than nuclear power generation to reduce the amount of power supplied.

(II) The second power supply step is intended for a period when the power demand decreases, and is a power supply method from time t to time t, for example from 6 o'clock in the evening to 4 o'clock the next morning. During this time period, standby power generation equipment3, which has poor power generation efficiency and is not economical,
3 Stop the power supply from... At this time, the amount of power supplied from the nuclear power plant 1.1... is set at the maximum, and fluctuations in power demand are adjusted by power supply by AFC operation of the non-nuclear power generation facilities 2.2... It is done. When the amount of power supplied by the AF'C operation of the regular power generation equipment 2.2... reaches the minimum allowable value, the AFC operation is canceled and the nuclear power plant 1.1 is used to reduce the power demand thereafter.
This will be handled by AFC operation. This nuclear power plant 1. The AFC operation of l... is performed by regulating the pump speed of the recirculation pump and reducing the reactor power. In this case, nuclear power plant 1.1.
When the power demand further decreases when the pump speed of the recirculation pump of ... is at its lowest and the amount of power supplied from other power generating equipment is at a minimum or zero, (1) overheating of the reactor feed water; The reactor output is reduced by raising the temperature of the reactor to make it easier to generate steam (bubbles), or (II) by bypassing excess steam to the condenser.

(IID The third power supply step targets the period from time t to tc during which the power demand increases. Specifically, it is a power supply method from 4:00 a.m. to 5:00 a.m. the next morning.Power supply during this period is , power generation equipment other than nuclear power generation 2, 2...
The power supply from .:3,3... is set to the minimum allowable value, and the fluctuation adjustment of the power demand is controlled by the nuclear power plant 1.1.
... is supplied by AFC operation by adjusting the flow rate (pump speed) of the recirculation pump. The upper limit of this AFC operation is 1.1 for nuclear power plants...
up to approximately 90% of the rated output. The shortfall in electricity demand at this time will be made up of regular power generation facilities other than nuclear power generation facilities 2, 2 and 2.
Covered by...

(t') The fourth power supply step targets the period from time t when power demand is rising to 14:00 the next day as td, and is a power supply method from 5:00 the next morning to 14:00 noon the next day. During this period, the power supply from the nuclear power plant should be controlled so that the power supply rise rate is kept below a predetermined limit and the pump speed of the recirculation pump is reduced, e.g. Raise the temperature slowly over a period of 3 hours until the

At that time, fluctuations in power demand can be controlled by AFC operation of regular power generation equipment other than nuclear power generation facilities 2.2...? - to do. When the power supply from the regular power generation facilities 2, 2... reaches its maximum value, the power supply from the nuclear power plants 1, 1... has not reached the maximum value (rated output), and therefore cannot meet the power demand. There may also be cases. In order to cover the shortfall in electricity demand, standby power generation equipment 3゜3... will be added to fill the gap between electricity demand and supply.

Furthermore, during this period, in response to a significant decrease in power demand during lunch breaks, etc., a power supply command is given to regular power generation facilities 2.2... other than nuclear power generation facilities to reduce the power supply.

Next, the power supply distribution procedure will be explained.

When starting the daily load operation, the actual value corresponding to the amount of electricity demanded - week ago (or the average actual value from one week to several weeks ago) is input into the calculation device 6 as the predicted electricity demand curve for the current day. (Step A).

Next, the actual power demand value for the current day is sequentially compared with the power demand forecast curve described above, and the power demand forecast curve for the current day is corrected (step B). On the other hand, each power generation equipment 1゜1...;2,
The amount of power that can be supplied from 2...; 3, 3... is input to the arithmetic unit 6 via the transmitter/receiver 5 (step C).

The input of the amount of power that can be supplied to the arithmetic unit 6 is performed for each power generation facility as described above, and the maximum power supply value (,) and (b)
) minimum power supply value, (C) power supply rising speed, etc. are input.

Next, the power demand curve A for the day is divided into four parts depending on the power supply mode, and each power supply step (I), (■), (I) is divided into four parts.
, 1 (It'), a power supply command is output from the arithmetic unit 6 to each power generation facility via the transmitter/receiver 5 (step D). This power supply command is as shown in the power supply determination table (Table 1), and it makes full use of the power supply from the highly economical nuclear power plant 1゜1... and reduces the overall power generation cost. can do.

(17) In the fourth power supply step (i) I), operation from 8:00 a.m. the next morning to 2:00 p.m. the next day, when the power demand is almost at its peak, is performed in accordance with the first power supply step (1). Ru. Therefore, this fourth power supply step (Is') is t3
to 8:00 the next morning, the period after 8:00 the next morning may be set as the fifth power supply step, or this period may be combined with the first regular power supply step (I).

Next, the actual power supply distribution work will be specifically explained.

The actual power demand is calculated by the power demand integration circuit shown in FIG. 3, the actual power demand P is integrated, and the integrated power demand up to each time is stored on a magnetic tape.

For example, the time tn is recorded on the magnetic tape at about I distribution.
Table 2, which shows the correspondence between the actual integrated power amount gr and the actual integrated power amount gr, is stored and saved on a floppy disk. For example, the storage on the floppy disk is from 14:00 to 14:00 the next day.
Unitize. In FIG. 3, the symbol R is a resistor, C is a capacitance (capacitor), and A is an operational amplifier.

Table 2 After predicting the electricity demand in this way, refer to the actual integrated electricity amount Er in Table 1, and then
(distribution), the average power demand amount pr is calculated using the following formula and tabulated as shown in Table 3.

Although the actual actual power demand oscillates as shown in Figure 2, the average power demand pZ for each hour smoothed by the first equation can be calculated, and this power amount is shown in Table 3. It is expressed as shown.

Table 3 Next, the power demand for the day is predicted.

This prediction is performed by picking up data of average power demand by time - weeks ago from a floppy disk, and calculating the pace average power demand Pb=Pr (-weeks ago) as n.

(21) Next, the predicted value of the power demand for the day is calculated from the power forecast circuit diagram shown in FIG. This calculation calculates the difference between the actual value of electricity demand for the current day (hereinafter referred to as actual electricity demand) and the pace average electricity amount Pn at the future time.
Let the value added to n+1 be the predicted value. Let the current time be 'It.

However, in Fig. 3, A is an operational amplifier and pr
is the average power demand at time t on the current day, and n n pr is the time tn-1n one hour before time t on the current day.
-1n pb is the average power demand at time t one week ago pb is the average power demand at time t one week ago 1n-1 "n+1 is -1 The average power demand at time tn+ on the current day Expected value of demand p41 is a predicted value of average power demand at the future time tN of the current day.

Subsequently, the predicted value of the calculated average power demand for the day is tabulated as shown in Table 4, and the output is stored on a floppy disk for preservation.

(22) Table 4 Based on the predicted power demand amount from 14:00 to 14:00 the next day calculated from Table 4, the power demand cycle is divided into four.

Note that the power demand decreases discontinuously and irregularly from 12:00 to 13:00 due to the lunch break.

The first power supply step (D; targets the period from 14:00 to time t (generally 18:00), and covers regular power generation such as nuclear power plants 1, 1, etc. and thermal power generation other than nuclear power generation during this target period. The amount of power generation that can be supplied from equipment 2, 2, etc. is assumed to be Pa.

Then, the predicted average power demand is set as PH, and this power demand P0 is compared with the suppliable power generation amount P.

m a The time 1 m at which PW=Pa is set to 18 theoretically.

Actually, the output v = P@-P <0o m shown in Fig. 5
Time t is calculated from the predicted power demand P@ which is a − .

In this power supply step <1), each power generation facility 1, 1...:2.2
...: 3, 3... transmits the power supply command shown in Table 1, and each power generation equipment 1.1...; 2, 2...: 3, 3...
・Operate based on the above power supply command.

Second power supply step (■); from time t to time t, which actually targets the period from 18:00 to 4:00 the next morning when the amount of power demand decreases.

In this case, the known power generation t that can be provided only by the nuclear power plants 1, 1, . . . is assumed to be P.

Therefore, the predicted average power demand P @ (however, t1<-)
is compared with the nuclear power supply capacity P2, and the time tITl at which p@=p is theoretically set to t. In fact, in Fig. 5, from the predicted average power demand pW where output v = Pe - 0m P,
).

In this second division step (II), similarly to the first division step (1), each power generation facility 1, 1, . . .
...: 3, 3... are operated or stopped.

Third power supply step (I); from time t5 to time t. to,
In reality, the target period is from 4:00 to 5:00 the next morning.

In this case, the power generation amount P0 is set to about 90% of the suppliable power generation amount P that can be borne by the power supply from the nuclear power generation J'l'rl, 1, . In actual reactor operation, in order to ensure the integrity of the fuel rods, it is necessary to
(approximately 1 hour) to set an upper limit when increasing the output to high. This upper limit value is 90% of the rated output based on the experience of reactor operation to date.
It is known that if the upper limit is within the above range, the integrity of the fuel rods will not be impaired even if the reactor output is suddenly increased in a short period of time.

Therefore, the theoretical setting of time 1c (>1.) is performed as follows. That is, predicted average power demand P:
Compare n with the 90% power generation amount Pc, and set the time tm at which P product=Pe to to. Actually V. =P:n-Pc
P≧0: Set 1c (corresponding to 5 o'clock the next morning) from n.

In the case of this third power supply step (1), as shown in Table 1, the power supply command from the arithmetic unit 6 is transmitted to the nuclear power plants 1.1... and the non-nuclear power generation facilities 2.2. ...is driven.

Fourth power supply step ■: 1 from time t. The period is until 2:00 p.m. In this case as well, each power generation facility is operated as shown in Table 1 in response to a power supply command from the arithmetic unit 6.

In the explanation of one embodiment of the present invention, an example was explained in which the daily power demand cycle is from 14:00 to 14:01 of the next day, but it is not necessarily limited to 2:00 p.m. Almost reaching its peak from 8:00 to 18:00
It is sufficient to set the time appropriately.

〔Effect of the invention〕

As described above, in the power supply distribution method and power supply distribution device according to the present invention, the power supply period of daily load operation is divided into several parts based on the predicted power demand, and the operating rate of the nuclear power generation equipment is calculated for each power supply step. By sending prioritized power supply commands from the computing device to each power generation facility and adjusting and distributing the amount of power supplied to each power generation facility, nuclear power generation facilities, which have low fuel costs and are highly economical, can be proactively and maximized. It can be used to reduce the total power generation cost. Even if this nuclear power generation equipment is actively and maximally utilized, the integrity of nuclear power generation can be maintained sufficiently by continuing to operate the nuclear reactor by utilizing the characteristics of the nuclear power generation equipment.

[Brief explanation of drawings]

FIG. 1 is a principle diagram showing an embodiment of a power distribution device implementing the power distribution method according to the present invention, FIG. 2 is a graph showing the power demand cycle in daily load operation, and FIG. 3 is a graph showing the power demand cycle in daily load operation. Figure 4 is a diagram showing the integration circuit. Figure 4 is a principle diagram of a prediction circuit that calculates the predicted value of the current day's power demand. Figure 5 is the boundary between each power supply step when dividing the daily power demand cycle into several parts. FIG. 2 is a principle diagram showing a theoretical calculation circuit for calculating time. 1... Nuclear power generation equipment, 2... Regular power generation equipment other than nuclear power generation, 3... Standby power generation equipment, 4... Central command center, 5... Transmitter/receiver, 6... Arithmetic unit, 7... Image display, A... Electric power demand curve in daily load operation.

Claims (1)

[Scope of Claims] 1. Power generation facilities are roughly divided into nuclear power generation facilities, regular power generation facilities other than nuclear power generation facilities, and standby power generation facilities such as aging thermal power generation facilities, and power is supplied for daily load operation based on predicted power demand. The feature is that the period is divided into several parts, and at each division step, a power supply command that prioritizes the operation rate of the nuclear power generation equipment is sent from the computing device to each power generation equipment, and the amount of power supplied from each power generation equipment is adjusted and distributed. power distribution method. 2. The power supply distribution method according to claim 1, wherein the predicted power demand is calculated based on the power demand curve one week before. 3. The power supply period for daily load operation is the first period with the highest power demand.
A power supply step, a second power supply step where power demand tends to decrease, and a period in which power demand gradually increases from the minimum value, in which the nuclear power generation equipment is controlled to reach the rated output of 90 degrees in a short time. a third power supply step for operating;
The power supply distribution method according to claim 1, wherein the nuclear power generation facility is divided into a fourth power supply step in which the nuclear power generation facility is operated at a gradual increase in the rated output between 90 and 100 degrees. 4- The power supply distribution method according to claim 143, wherein the controlled operation of the nuclear power generation facility is performed by adjusting and controlling the pump speed of a recirculation pump. 5. The first power supply step is from an appropriately set time between 8 a.m. and 6 a.m., until 6 a.m., the second power supply step is from 6 a.m. to 4 a.m., and the third power supply step is from 6 a.m. to 4 a.m. the next morning. from 4:00 a.m. to 5:00 a.m. the next morning.
4. The power supply distribution method according to claim 3, wherein the power supply distribution method is from time to time to the set time. 6. Each power generation facility is composed of nuclear power generation facilities, regular power generation facilities other than nuclear power generation facilities, and backup power generation facilities such as aging thermal power generation facilities, as well as transmitters and receivers that exchange information between each power generation facility and the central command center, and forecasting. In order to adjust the distribution of the amount of power supplied from each power generating facility according to the amount of power demand, the computing device issues a power feeding command, and the computing device issues a power feeding command that prioritizes the operation rate of the nuclear power generating facility. A power supply distribution device characterized in that the power is transmitted to each power generation facility via the transmitter/receiver, and each power generation facility is operated in a controlled manner. 7. The calculation device has a calculation circuit that calculates the predicted power demand based on the power demand curve of one week ago, and the calculation device electrically connects to an image display device that compares and displays the power demand and power generation amount. Power distribution device according to attached claim 6.