JP2017101845A - Water supply function auxiliary system, water supply function auxiliary method and water supply function auxiliary program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a water supply function auxiliary system, a water supply function auxiliary method and a water supply function auxiliary program capable of maintaining a water volume supplied to a steam generation section even on the occurrence of a brief reduction or loss in supply voltage to a pump.SOLUTION: A water supply function auxiliary system 10 comprises: a condenser 13 which obtains steam condensate by condensing steam generated in a power generation plant; a steam generator 11 which evaporates water supplied by the condenser 13 as the steam condensate; a steam condensate supply system 14 which connects the condenser 13 and the steam generation section 11 and supplies the water to the steam generation section 11; a motor driven pump 17 which is installed in the steam condensate supply system 14, pumps the water and transfers the same to the steam generation section 11; an accumulation section 18 which is a closed space installed close to an inflow port of the pump 17 and accumulates the water; and a pressurization section 19 which applies pressure to the accumulation section 18 by supplying gas thereto when detecting a reduction in supply voltage to the steam condensate supply system 14.SELECTED DRAWING: Figure 1

Description

  Embodiments of the present invention relate to a water supply function assist technology in a power plant.

In a power plant such as a nuclear power plant or a thermal power plant, steam exhausted from a turbine is condensed by being cooled by a condenser.
Condensed water flows through the condensate water supply system connected to the condenser while repeating heat exchange, is adjusted to an appropriate temperature, and is supplied to a steam generator such as a nuclear reactor, a steam generator, or a boiler. The
This water that flows through the condensate water supply system and is supplied to the steam generator is called water supply.

A plurality of pumps are provided in the condensate water supply system in order to pump water from the condensate water supply system to the steam generator.
Among these pumps, a condensing pump disposed on the condenser side is an electric motor driven pump that is driven by electric power from the outside.
In addition, as the feed water pump disposed on the steam generation unit side, such an electric motor-driven pump and a turbine-driven pump driven by steam from the turbine are appropriately selected and used.
Since the motor-driven pump has a small number of incidental facilities and is easy to maintain, it is often required to adopt a motor-driven pump as the water supply pump.

By the way, the power plant may be disconnected from the power system by a circuit breaker in order to block the influence of a sudden short circuit in a part of the power transmission network.
The phenomenon in which the electrical load of the generator rapidly decreases due to this disconnection is called load interruption.
Immediately after a load interruption occurs during normal operation of the power plant, the turbine output does not change and the electrical load of the generator decreases rapidly, so the rotational speed of the turbine increases.

If the rotational speed of the turbine increases excessively, there is a risk of accidents such as turbine missiles occurring.
Therefore, in this case, the supply pipe for supplying steam to the turbine is suddenly closed, and the turbine output is reduced to the electric power used in the power plant to shift to the in-house single operation in preparation for the plant restart.
In addition, the power plant may be stopped instead of the in-house single operation.

By the way, there are many causes of voltage drop due to natural disasters such as lightning or wind and rain, and voltage drop may occur for a very short time due to these natural disasters.
When a specific power transmission line that has received lightning strikes and causes a large current to flow, the power transmission line is instantly disconnected from the power grid of the power system by a circuit breaker to prevent the power outage range from expanding.
The voltage around the short-circuited transmission line is reduced only for a short time until this disconnection is made.
Such a phenomenon that the voltage of the power system decreases for a short time is called instantaneous voltage decrease (instantaneous decrease).

  In addition, the phenomenon in which the voltage around the short-circuited transmission line becomes zero for about several tens of milliseconds to several tens of seconds until the transmission line is disconnected from the power system by the circuit breaker is called instantaneous power failure (instant interruption). .

JP 11-311402 A

It takes a lot of time to shift the operation that has once stopped or moved to the independent operation to the normal operation again.
Therefore, it is desired to maintain the power supply without disconnecting the power plant from the power system and without causing the power plant to temporarily stop or shift to in-house single operation when an instantaneous drop or instantaneous interruption occurs.
Such a function of maintaining the power supply without temporarily stopping the power plant or shifting to the in-house single operation is called FRT (Fault Ride Through).
In particular, in order to cope with instability of the electric power system accompanying the expansion of the introduction of renewable energy in recent years, there is an increasing demand for power plants such as nuclear power and thermal power to have such an FRT function.

However, if FRT is performed at the time of occurrence of instantaneous drop or instantaneous interruption, steam necessary for the output required for the turbine is supplied from the steam generation unit to the turbine.
On the other hand, the discharge flow rate of the motor-driven pump installed in the condensate water supply system decreases due to a momentary drop or a decrease in driving force due to momentary interruption.
Thus, when the discharge flow rate of the pump of the condensate water supply system decreases, the amount of water flowing into and out of the steam generating unit becomes unbalanced, and the water level in the steam generating unit decreases.

When the water level in the steam generator falls below a predetermined threshold of the steam generator, the power plant automatically stops.
That is, in the above-described conventional technology, there is a problem that even if an attempt is made to maintain power supply by FRT, the water level of the steam generating unit is lowered due to a decrease in the driving force of the pump, and the power plant may be stopped.

The present invention has been made in consideration of such circumstances, and a water supply function capable of maintaining the amount of water supplied to the steam generating section even if a short-time decrease or loss of supply voltage to the pump occurs. It aims at providing an auxiliary system, a water supply function assistance method, and a water supply function assistance program.
And more broadly, to provide a water supply function assistance system, a water supply function assistance method, and a water supply function assistance program capable of continuing the operation of a power plant even if a short-time supply voltage drop or loss occurs With the goal.

  A water supply function auxiliary system according to the present embodiment includes a condenser that condenses the steam generated in the power plant to condense, a steam generation unit that converts the feed water condensed in the condenser into steam, and a condensate. A condensate water supply system that connects the steam generator and the steam generator to supply water to the steam generator, an electric motor-driven pump that is installed in the condensate water supply system and pumps the feed water and transfers it to the steam generator; A stopping part that is installed in the vicinity of the inlet of this pump and stops the water supply, and a pressurizing part that supplies gas to the stopping part and pressurizes when a drop in the supply voltage to the condensate water supply system is detected Are provided.

  The water supply function assisting method according to the present embodiment includes a step of condensing the steam generated in the power plant to condense, and pumping up the water that has been condensed with an electric motor-driven pump to the steam generating unit. A step of supplying, a step of stopping water supply in a closed space installed in the vicinity of the inlet of the pump, and a step of supplying gas to the water supply stopped when the supply voltage to the pump is reduced and pressurizing. Is included.

  The water supply function auxiliary program according to the present embodiment includes a step of condensing steam generated in the power plant by condensing it in a computer, pumping up the water condensed by the motor-driven pump, and generating steam. A step of supplying water to the pump, a step of stopping water supply in a closed space installed in the vicinity of the inlet of the pump, and a step of supplying gas to the water supply stopped when the supply voltage to the pump decreases and pressurizing It is something to be made.

  The water supply function assistance program according to the present embodiment is a water supply function assistance program that assists the supply of water to a steam generation unit installed in a power plant with an electric motor driven pump. The step of stopping the water supply in the closed space where it is installed, and the step of supplying and pressurizing the gas to the water supply to be stopped when the supply voltage to the pump drops are executed.

EFFECT OF THE INVENTION According to the present invention, a water supply function auxiliary system, a water supply function auxiliary method, and a water supply function auxiliary program capable of maintaining the amount of water supplied to a steam generator even if a short time drop or loss of the supply voltage to the pump occurs Is provided.
More broadly, a water supply function auxiliary system, a water supply function auxiliary method, and a water supply function auxiliary program capable of continuing the operation of the power plant even if a short-term supply voltage drop or loss occurs are provided. .

The schematic block diagram of the water supply function assistance system concerning 1st Embodiment. Schematic which shows the relationship between the pump head and discharge flow volume. The schematic block diagram of the water supply function assistance system concerning 2nd Embodiment. The schematic block diagram of the water supply function assistance system concerning 3rd Embodiment. The schematic block diagram which shows the modification of the water supply function assistance system concerning 3rd Embodiment. The schematic block diagram of the modification of the water supply function assistance system concerning 3rd Embodiment. The flowchart which shows the water supply function assistance method concerning 1st Embodiment.

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

(First embodiment)
FIG. 1 is a schematic configuration diagram of a water supply function assistance system 10 (hereinafter simply referred to as “auxiliary system 10”) according to the first embodiment.

The auxiliary system 10 according to the first embodiment is suitably applied to a power plant such as a nuclear power plant that generates power by circulating water while changing its phase as needed.
For example, in a nuclear power plant, as shown in FIG. 1, steam generated by a steam generator 11 such as a pressure vessel is sequentially supplied to a plurality of turbines connected in series and used as power.

The steam that is the power of the low-pressure turbine 12 provided in the last stage is condensed and condensed by the condenser 13 connected to the low-pressure turbine 12.
The condensate condensed in the condenser 13 repeats heat exchange in the heat exchangers 16 installed in a plurality of locations while flowing through the condensate water supply system 14 to be supplied to the steam generation unit 11 again as water supply. The

The condensate water supply system 14 is provided with a condensate pump 17a and a water supply pump 17b in order from the upstream side.
The condensate water supply system 14 includes a condensate system 14a in a section from the condenser 13 to the feed water pump 17b, and a water supply system 14b in a section from the feed water pump 17b to the steam generating unit 11.
The condensate flowing through the condensate system 14 a flows into the water supply system 14 b and is supplied to the steam generator 11 as feed water.
In the following embodiments, water supply and condensate are collectively referred to as water supply without particularly distinguishing them.

A plurality of condensate pumps 17a and feed water pumps 17b may be provided depending on the shape, scale, or amount of flowing water of the condensate feed water system 14, respectively.
An electric motor drive type is used for the condensate pump 17a.
Further, as the feed water pump 17b, a turbine drive type or a motor drive type is appropriately selected.

However, any water supply pump 17b will be described as an electric motor-driven water supply pump 17b that is affected by a supply voltage such as a momentary drop or a momentary interruption.
That is, any pump 17 (17a, 17b) will be described as being driven by an electric motor.

  The decrease in the amount of water flow of the pump 17 in the condensate water supply system 14 due to the instantaneous drop or the instantaneous interruption can be explained as follows.

The required pump power P for pumping the required flow rate during normal operation by the required head is expressed by the following equation (1).
P = ρ × g × Q × H / η (1)
However, P: Required pump power [W], ρ: Fluid density [kg / m ³ ], Q: Volume flow rate [m ³ / s], H: Lifting head [m], η: Pump efficiency [−] .

The rotational kinetic energy of the rotor of the pump 17 is expressed by the following equation (2).
^{K = ∫Τωdt = I × ω 2} /2 (2)
Where K: rotational kinetic energy [J], Τ: torque [N · m], I: moment of inertia [kg · m ² ], ω: angular velocity [rad / s].

When there is no torque か ら generated from the electric motor due to the voltage drop, the necessary pump power P expressed by the equation (1) is consumed every minute from the rotational kinetic energy K held by the rotor of the pump 17 during normal operation. As the time elapses, the pump rotation speed decreases.
As the pump rotational speed decreases, the discharge flow rate of the pump 17 decreases.
Note that the actual decrease in the discharge flow rate is influenced by the inertial force of the fluid and the loss due to the structure of the pump 17 in addition to the above description.

Here, the number of rotations of the rotor and the discharge flow rate of the pump 17 will be described in more detail with reference to a schematic diagram showing the relationship between the lift of the pump 17 and the discharge flow rate of FIG.
The discharge flow rate and the lift of the pump 17 when the power plant is operating normally are the intersection A of the total lift curve p of the rotational speed of the rotor of the pump 17 and the pipe resistance curve r during normal operation (normally Operation point A).

The total head curve is a pump performance curve showing the relationship between the pump discharge flow rate and the head, and is also called a QH curve.
The total head curve shows that when the rotational speed of the rotor built in the pump is reduced, the lift is proportional to the square of the rotational speed, and the discharge flow rate is proportional to the rotational speed (p → q). .

In addition, the pipe resistance curve is the difference between the head of the pump (actual head H (H ₁ , H ₂ )) when there is no pump discharge flow and the loss head such as pipe resistance accompanying the increase in discharge flow. This is also called a system head curve.

In the total head curve q when the rotation is decelerated, the pump operating point is the intersection B (deceleration operating point B) with the pipe resistance curve r.
In other words, the pump operating point changes from the normal operating point A in FIG. 2 to the operating point B during deceleration due to the deceleration of the rotation of the rotor, so that the pump discharge flow rate decreases.
The pumping limit point when the pump rotor is decelerated is realized by the fact that the pump's cutoff lift and the actual lift H match.

Here, if the actual head H can be lowered from H ₁ to H ₂ , the pipe resistance curve moves in parallel from r to s, and the pump operating point at the time of voltage drop moves from the intersection B to the intersection C.
Actual head H, so is expressed by the following equation (3) using the push actual head H _s, the pipe resistance curve is moved from r to s by adding a push actual head H _s the actual head H of the pump be able to.
H = H _a + H _b −H _s (3)
However, H _{a is the} suction actual lift, and H _{b is the} discharge actual lift.
That is, by reducing the actual head H from H ₁ to H ₂ by assisting the inflow of the feed water into the pump 17, the discharge flow rate can be recovered to the same level as the normal operating point A.

  Therefore, the auxiliary system 10 according to the first embodiment is stopped when a decrease in the supply voltage to the stop 17 and the stop 17 that is installed in the vicinity of the inlet of the pump 17 and stops the supply water is detected. And a pressurizing unit 19 that supplies and pressurizes the gas to the unit 18.

The stopping part 18 is normally arranged in the vicinity of the inlet of the feed water pump 17b closest to the steam generating part 11.
This is because the amount of water and the water pressure flowing into the steam generator 11 are directly determined by the amount of water discharged from the feed water pump 17b and the water pressure.
That is, the feed water pump 17b becomes an important pump in continuing the operation of the power plant.

For the same reason, when a plurality of water supply pumps 17b are arranged in series, it is desirable to arrange them near the inlet of the most downstream one.
However, due to the design of the water supply system 14b, it may be difficult to install the stop 18 near the inlet of the water pump 17b on the most downstream side.
In such a case, the stop 18 may be installed in the vicinity of the inlet of the water supply pump 17b on the more upstream side, or in some cases, the condensate pump 17a.
In order to simplify the description, it is assumed that the stop 18 is installed in the vicinity of the inlet of the most downstream feed water pump 17b.

The influence on the amount of flowing water due to the decrease in the discharge flow rate of the pump 17 is particularly noticeable when the pumps 17 are arranged in series.
This is because the downstream pump 17 is affected by a decrease in the discharge flow rate of the upstream pump 17 in addition to a decrease in driving force due to a decrease in supply voltage.
In addition to facilitating the pressurization of the feed water flowing into the feed water pump 17b by stopping the feed water at the stop portion 18, the influence of the change in the flow rate of the feed water upstream of the stop portion 18 can be reduced. it can.

The “near the inlet of the pump 17” refers to the upstream side of the pump 17 and the downstream side of the other pumps 17 upstream of the pump 17.
However, when there is another device that changes the water pressure of the feed water between the pump 17 and another pump 17 on the upstream side, it indicates the upstream side of the pump 17 on the downstream side of this device.

For example, as shown in FIG. 1, the pressurizing unit 19 includes a gas supply pipe 22 that branches a transfer pipe 21 that transfers the steam generated in the steam generating unit 11 and connects to the gas phase part of the stopping unit 18, and a gas A pressurization control valve 23 provided in the supply pipe 22 and a monitoring unit 24 that opens the pressurization control valve 23 when the supply voltage to the feed water pump 17b is reduced or lost ("supply power monitoring unit 24" in FIG. 1). )).
The monitoring unit 24 monitors the supply voltage of the water supply pump 17b to which the stop unit 18 is connected while the condensate water supply system 14 is in operation.

  When the monitoring unit 24 detects a decrease or loss in the supply voltage to the pump 17b and the pressurization control valve 23 is opened, the high-pressure steam flowing through the transfer pipe 21 is supplied from the gas supply pipe 22 to the stop 18. .

In addition, the monitoring part 24 is not limited to what monitors the supply voltage to the pump 17b as mentioned above, For example, the fall of the water pressure of the water supply which stops in the instantaneous drop or short interruption of an electric power system, or the stop part 18 is shown. It may be monitored.
Furthermore, the control of the pressurizing unit 19 is not limited to that by electrical control such as the monitoring unit 24, and even if the pressurization control valve 23 is mechanically opened due to a decrease in supply voltage. Good.

However, since the main purpose of this pressurization is to maintain the power supply from the power plant even if an instantaneous drop or interruption occurs, pressurization is started immediately in response to the instantaneous drop or interruption. Make it possible.
Further, the high-pressure steam source of the pressurizing unit 19 has been described by raising the transfer pipe 21 as an example, but is not limited to this example as long as steam having a pressure higher than the internal pressure of the retaining unit 18 can be supplied to the retaining unit 18.

The feed water that is pressurized by the supplied steam to become a high water pressure and stops in the stop 18 is supplied to the feed pump 17b.
The amount of water discharged from the water supply pump 17b is maintained by this pressurized water supply from the stop 18.
In other words, the decrease in the total lift due to the decrease in the supply voltage is calculated by using the relationship of Equation (3) to lower the actual lift H by adding the actual push lift H _s , and the operating point after assisting the operating point. C.
That is, by reducing the actual head H of the feed water pump 17b, a reduction in the feed water flow rate to the steam generator 11 accompanying the deceleration of the pump 17 is prevented.

In the first embodiment, since the gas is the steam generated in the steam generating unit 11, most of the gas that has contacted the temporarily stored water is condensed and does not contribute to an increase in water pressure.
Therefore, in the case where the gas is easily condensed, such as steam, the shape of the retaining portion 18 is made deeper than the longest straight line that can be drawn on the bottom 25 (horizontal section).
For example, when the stop 18 is a cylindrical tank, the depth of the tank is preferably deeper than the diameter of the circle of the horizontal section 25.

With such a shape, the contact area between the supplied steam and the stored water is reduced, so that the heat exchange between the water stored in the retaining portion 18 and the high-pressure steam is reduced, and the slowing of the pressure increase inside the retaining portion 18 is suppressed. The effect is also demonstrated.
The detailed aspect ratio of the retaining portion 18 is determined from the amount of high-pressure steam to be supplied, the required increase rate of the internal pressure of the retaining portion 18, and the like.
The stopping part 18 is not limited to the tank as described above.
For example, if the stop 18 can pressurize the suction side of the water supply pump 17b, such as forming a water storage mechanism inside the water supply pipe provided with the water supply pump 17b, the same effect can be obtained.

  Next, an auxiliary method according to the first embodiment will be described with reference to the flowchart of FIG. 7 (refer to FIG. 1 as appropriate).

After being used for power generation as a turbine drive source, the condenser 13 condenses the steam and condenses it (S11).
The feed water condensed from the steam is pumped by the pump 17 and flows while the condensate water supply system 14 is stopped at the stop 18 and is supplied to the steam generator 11 (S12).
And in the steam generation part 11, this water supply is heated and a steam is generated (S13).

During this time, the monitoring unit 24 monitors the supply voltage to the water supply pump 17b (S14).
If there is no drop in the supply voltage, the monitoring unit 24 continues the normal operation while continuing the monitoring (S15: NO: to S13).
When there is a drop in the supply voltage (S15: YES), the monitoring unit 24 opens the pressurization control valve 23, supplies steam, and pressurizes the feed water in the stopping unit 18 (S16).

The pressurized water supply flows into the water supply pump 17b from the stop 18 and suppresses a decrease in the amount of water discharged from the water supply pump 17b (S17).
The pressurizing unit 19 continues to pressurize by supplying steam until the rotation speed of the rotor of the pump 17b increases to the extent that the supply voltage rises to a normal value and the pressurization to the stop unit 18 becomes unnecessary ( S18: NO: Go to S16).
When the rotational speed of the rotor of the pump 17b has increased to a normal value (S18: YES), pressurization is terminated (S19).

  As described above, according to the auxiliary system 10 according to the first embodiment, by reducing the actual head H of the pump 17 by pressurization at the time of a momentary drop or a momentary interruption, even if such a momentary drop occurs, the power generation plant Power supply can be maintained.

(Second Embodiment)
FIG. 3 is a schematic configuration diagram of the auxiliary system 10 according to the second embodiment.
As shown in FIG. 3, in the auxiliary system 10 according to the third embodiment, the stopping unit 18 is a deaerator 26 that degass the water supply.
The deaerator 26 is installed between the pumps 17 or upstream of the pump 17 and is installed in the condensate water supply system 14 of many power plants for the purpose of reducing the amount of dissolved oxygen.

Since the deaerator 26 temporarily stores water for deaeration, the deaerator 26 also has an effect of absorbing fluctuations in the water supply.
In the third embodiment, supplying the gas to such a deaerator 26 also serves as the function of the retaining portion 18.

The water supply deaerated by the deaerator 26 is in a saturated state and is easily vaporized to form bubbles due to a minute drop in water pressure, impact or temperature drop.
Therefore, the effective suction water head (effective NPSH: Net Positive Suction Head) of the water supply pump 17b may fall below the required NPSH.
For reasons such as supplementing this effective NPSH, it is common to provide a feed water booster pump 17 c in the vicinity of the inlet of the feed water pump 17 b provided downstream of the deaerator 26.

The feed water pump 17b and the feed water booster pump 17c generally share a drive machine, and share the same rotating shaft by the drive machine.
When the rotation axis is shared, if the rotation of the rotor of the water supply booster pump 17c is changed, the rotation of the water supply pump 17b is also changed.
Therefore, in this case, the deaerator 26 may be placed near the inlet of the feed water booster pump 17c on the upstream side of the feed water pump 17b for pressurization.

  As described above, according to the second embodiment, the power supply from the power generation plant is maintained even if an instantaneous drop or instantaneous interruption occurs, as in the first embodiment, without newly installing the stopping unit 18. be able to.

In addition, since 2nd Embodiment becomes the same structure and operation | movement procedure as 1st Embodiment except providing the existing deaerator 26 as the stop part 18 and providing the water supply booster pump 17c as needed, it overlaps. Description to be omitted is omitted.
Also in the drawings, portions having a common configuration or function are denoted by the same reference numerals, and redundant description is omitted.

As described above, according to the auxiliary system 10 according to the second embodiment, the deaerator 26 that is normally installed in a pressurized water nuclear power plant or a thermal power plant is used as the stopping unit 18, so that the existing configuration or design can be achieved. As in the first embodiment, the power supply from the power plant can be maintained even if a voltage sag or a power interruption occurs.
Moreover, by making the stop part 18 into the deaerator 26, it is possible to prevent the configuration of the condensate water supply system 14 from being unnecessarily complicated, and to suppress an increase in the number of parts.
Furthermore, when the deaerator 26 is included in the existing design configuration, the water supply function can be assisted by a slight design change.

(Third embodiment)
FIG. 4 is a schematic configuration diagram of the auxiliary system 10 according to the third embodiment.
In the auxiliary system 10 according to the third embodiment, as shown in FIG. 4, the gas supplied to the retention unit 18 is an inert gas.

A suitable inert gas is, for example, nitrogen or argon.
The pressurizing unit 19 is a gas storage unit 27 such as a cylinder for storing these inert gases.
The gas storage unit 27 is connected to the stop unit 18.
As in the first embodiment, the pressurization control valve 23 is opened when the monitoring unit 24 detects an instantaneous drop or an instantaneous interruption.

Since the inert gas does not condense due to heat exchange like steam, it is not necessary to create a gas phase part in the stationary part 18.
Therefore, it is possible to pressurize even if the inside of the stop part 18 is in a full water state.
Further, since the inert gas does not dissolve in the feed water and does not reduce the volume, the inside of the retaining portion 18 is instantaneously pressurized with the supply, and the delay in the pressure increase as when the steam is supplied does not occur.

FIG. 5 is a schematic configuration diagram showing a modification of the auxiliary system 10 according to the third embodiment.
As shown in FIG. 5, the stopping part 18 is arranged in the flow path of the condensate water supply system 14, and the condensate water supply system 14 is branched and connected without making the stopping part 18 a part of the flow path. May be.
However, in this case, since most of the water supply does not pass through the stop 18, the stop 18 is made part of the flow path as shown in FIG. Is desirable.

In addition, when the stopping part 18 does not become a part of the water supply flow path, the retained water does not circulate inside the stopping part 18, so that the temperature of the retained water is not heated separately. It becomes lower than the water supply of the condensate water supply system 14.
Therefore, when the retained water having a low temperature is pressurized with steam and this retained water is supplied to the water supply, there is a risk of generating a steam hammer.
Therefore, if a temperature difference occurs between the retained water and the water supply of the stopping part 18 by branching and connecting the stopping part 18 from the condensate water supply system 14, the gas used for pressurization should be an inert gas. Is desirable.

  Further, as shown in FIG. 6, the inert gas may be supplied to the deaerator 26 by combining the second embodiment with the third embodiment of the auxiliary system 10.

In addition, since 3rd Embodiment becomes the same structure and operation | movement procedure as 1st Embodiment etc. except the gas supplied to the stop part 18 being an inert gas, the overlapping description is abbreviate | omitted.
Also in the drawings, portions having a common configuration or function are denoted by the same reference numerals, and redundant description is omitted.

  As described above, according to the auxiliary system 10 according to the third embodiment, in addition to the effects of the first embodiment, it is possible to supply appropriate water pressure and water amount without delay in the instantaneous drop or instantaneous interruption.

According to the auxiliary system 10 of at least one embodiment described above, it is possible to maintain the amount of water supplied to the steam generator 11 even if the supply voltage to the pump 17 is reduced or lost for a short time. Become.
In addition, this makes it possible to continue the operation of the power plant even if the supply voltage is reduced or lost for a short time.

Although several embodiments of the present invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention.
These embodiments can be implemented in various other forms, and various omissions, replacements, changes, and combinations can be made without departing from the scope of the invention.
These embodiments and their modifications are included in the scope and gist of the invention, and are also included in the invention described in the claims and the equivalents thereof.

For example, the steam supplied to the stop 18 may be steam generated by an auxiliary boiler installed in the power plant, and is not limited to steam generated by the steam generator 11.
Moreover, the water supply supplied to the steam generation part 11 is not necessarily limited to what circulates circularly, changing the state of the steam generation part 11 and the condenser 13.

DESCRIPTION OF SYMBOLS 10 ... Water supply function auxiliary system (auxiliary system), 11 ... Steam generation part (pressure vessel), 12 ... Low pressure turbine, 13 ... Condenser, 14 (14a, 14b) ... Condensate water supply system (condensate system, water supply system) ), 16 ... heat exchanger, 17 (17a, 17b, 17c) ... pump (condensate pump, feed water pump, feed water booster pump), 18 ... stopping part, 19 ... pressurizing part, 21 ... transfer pipe, 22 ... gas Supply pipe, 23 ... pressurization control valve, 24 ... supply voltage monitoring part (monitoring part), 25 ... bottom part, 26 ... deaerator, 27 ... gas storage part, A ... normal operating point, B ... operating point during deceleration, C: Operating point after assistance, K: Rotational kinetic energy, H (H ₁ , H ₂ ) ... Actual lift, P ... Required pump power, p, q: Full lift curve, r, s: Pipe resistance curve.

Claims (10)

A condenser that condenses the steam generated in the power plant to condense,
A steam generator that converts the feed water condensed by the condenser into steam;
A condensate water supply system for connecting the condenser and the steam generator to supply the water to the steam generator;
An electric motor driven pump installed in the condensate water supply system to pump the water supply and transfer it to the steam generator;
A stopping part that is a closed space installed near the inlet of the pump to stop the water supply;
A water supply function assisting system comprising: a pressurization unit that supplies and pressurizes gas to the stop when a decrease in supply voltage to the condensate water supply system is detected. The water supply function assisting system according to claim 1, wherein the stop portion is connected to the vicinity of an inlet of a water supply pump arranged closest to the steam generating portion of the pump. The water supply pump includes an electric motor driven booster pump,
The water supply function assisting system according to claim 2, wherein the stop is provided in the vicinity of an inlet of the booster pump.   The water supply function assisting system according to claim 3, wherein the stop portion is a deaerator that deaerates the water supply flowing into the pump. The water supply function assisting system according to any one of claims 1 to 4, wherein the gas is the steam generated in the steam generation unit. The water supply function assisting system according to any one of claims 1 to 4, wherein the gas is an inert gas. The water supply function assisting system according to any one of claims 1 to 6, wherein the stop portion has a deep bottom shape deeper than a longest straight line that can be drawn in a horizontal section. Condensing and condensing steam generated in the power plant;
A step of pumping water supplied with the steam condensed by an electric motor-driven pump and supplying it to the steam generating unit;
Stopping the water supply in a closed space installed near the inlet of the pump;
Supplying a gas to the water supply that is stopped when the supply voltage to the pump drops and pressurizing the water supply function. On the computer,
Condensing and condensing steam generated in the power plant,
A step of pumping the feed water condensed with the steam by an electric motor-driven pump and supplying it to the steam generator;
Stopping the water supply in a closed space installed near the inlet of the pump;
A water supply function assisting program that executes a step of supplying a gas to the water supply that is stopped when the supply voltage to the pump is lowered and pressurizing the water supply. In the water supply function assistance program that assists the supply of water to the steam generator installed in the power plant with a motor-driven pump,
On the computer,
Stopping the water supply in a closed space installed near the inlet of the pump;
A water supply function assisting program that executes a step of supplying a gas to the water supply that is stopped when the supply voltage to the pump is lowered and pressurizing the water supply.

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