JP7144751B2 - Steam plant and steam flow control method - Google Patents

Description

TECHNICAL FIELD The present invention relates to a steam plant for controlling the minimum load steam flow rate, which is kept flowing to suppress the generation of condensate in steam pipes accompanying steam transport between steam generating equipment and steam using equipment, and a method for controlling the steam flow rate thereof. .

2. Description of the Related Art Conventionally, in operation of steam in a steam plant, it is common to use steam produced in a steam generating facility in a steam using facility. For example, as steam generation equipment in the steel process, exhaust heat generated in the process is effectively used from the viewpoint of energy saving, such as a converter exhaust heat recovery boiler, a sintering exhaust heat recovery boiler, and a coke dry cooling equipment. is well known. On the other hand, steam-using equipment includes steam turbine equipment that drives a steam turbine and serves as a driving source for a large rotating machine, and decompression equipment that further reduces the pressure and utilizes it as in-house low-pressure steam.

In some cases, a generator is attached to the steam turbine to generate power and use it as an energy recovery facility. Here, if the load balance between the steam generation facility and the steam usage facility is balanced, there is no problem. On the side of the steam using facility, load adjustment is performed to adjust the amount of load on the steam turbine. Energy recovery equipment, in which a generator is attached to a steam turbine, is easy to adjust the load, so it is often used as equipment for load adjustment in the case of processes that generate excess steam.

However, the operating range of the steam turbine has upper and lower steam flow restrictions, and surplus steam cannot be utilized below the lower limit steam flow rate. If the surplus steam exceeds the lower limit of the steam turbine and is generated, the steam turbine generator recovers the energy. For load adjustment in this case, the operator often manually starts and stops the equipment while checking the balance of each steam generation amount.

In addition, when a plant is located on a large site, such as in the steel process, the distance between the steam generating equipment and the steam using equipment is long, and there are cases where drainage occurs in the steam transportation piping. brought into the steam-using equipment side, it becomes impossible to satisfy the steam-using conditions of the equipment, which may lead to equipment troubles. Therefore, as a measure to prevent drain, a drain trap is installed in the steam transport pipe to discharge the drain, or a measure is taken such that the steam that does not generate drain is always flowing in the steam pipe. For example, Patent Literature 1 discloses a technique for suppressing drain generation by detecting the steam temperature and steam pressure on the side of steam-using equipment and controlling the superheater on the side of steam generating equipment.

Japanese Patent Application Laid-Open No. 9-137911

However, the conventional technique described above still has the following problems to be solved.
When the operator adjusts the overall load while looking at the overall load balance of the steam generating equipment and the steam using equipment, depending on the operator's skill level and oversight, it may be possible to recover energy by the steam turbine generator. In addition, there were cases in which decompression recovery to low-pressure steam was continued and opportunities for energy recovery were missed. In addition, when installing drain traps in order to suppress the generation of drain in long-distance steam transportation piping, it is necessary to install a large number of drain traps, which increases equipment costs, and regular maintenance costs for these facilities. is also required. Depending on the structure of the steam transport piping, there are cases in which drainage cannot be discharged well even if a drain trap is installed in a winding piping. On the other hand, there is also a method to keep enough steam flowing in the steam transportation pipe to prevent the generation of drainage, but if the opening of the control valve is kept constant, excess steam will be generated more than the amount of steam required to suppress the generation of drainage. It may flow.

In addition, in the technology described in Patent Document 1, feedback control can be applied when the distance between the steam generating equipment and the steam using equipment is short. In addition to being difficult to control, a device is required to adjust the degree of superheat of the steam on the steam generation equipment side. .

The present invention has been made in view of the above circumstances, and its object is to suppress the generation of drain accompanying steam transport between steam generating equipment and steam using equipment, and to reduce the loss of energy recovery opportunities. 1. To provide a steam plant capable of effectively utilizing steam, and to propose a steam flow rate control method using the facility.

A steam plant according to the present invention, which has been developed to solve the above problems and achieve the above objects, comprises a steam generating facility, steam turbine facilities, energy recovery facilities, and steam using facilities including pressure reducing facilities, which are connected in a piping system. A connecting steam plant comprising:
a first branch to the steam turbine equipment and steam using equipment other than the steam turbine equipment in the piping system;
a second branch to the energy recovery equipment and the pressure reducing equipment is provided in the piping to the steam using equipment other than the steam turbine equipment;
a steam control valve in at least one of the downstream pipes of the first branch; a first flow meter in the pipe to the steam turbine equipment; a second flow meter upstream from the branch,
a valve opening degree adjusting mechanism that adjusts the valve opening degree of the steam control valve according to the flow rate of each steam branched to the downstream pipe of the first branch;
an energy recovery facility start/stop determination mechanism for controlling the start and stop of the energy recovery facility according to the flow rate of the steam diverted to the piping to the steam using facility other than the steam turbine facility;
The valve opening control mechanism is characterized in that it is configured to obtain the value of the minimum load steam flow rate of the long-distance steam transportation pipe from a temperature compensating mechanism that adjusts according to the outside air temperature.

Regarding the steam plant according to the present invention,
a said energy recovery facility is a steam turbine generator;
is considered to be a more preferable solution.

A steam flow rate control method according to the present invention, which has been developed to solve the above problems and achieve the above objects, is a method for supplying steam generated in a steam generating facility to steam using facilities including a steam turbine facility, an energy recovery facility, and a pressure reduction facility. When distributing
The degree of valve opening of a steam control valve provided on the downstream side of at least one of the first branch of the piping leading to the steam turbine equipment and the steam using equipment other than the steam turbine equipment Adjust according to each steam flow rate,
controlling start and stop of the energy recovery equipment according to the steam flow rate to the steam using equipment other than the steam turbine equipment;
In adjusting the valve opening of the steam control valve, it is characterized in that the value of the minimum load steam flow rate of the long-distance steam transportation pipe, which is obtained according to the outside air temperature, is used.

In addition, regarding the steam flow rate control method according to the present invention,
a using a steam turbine generator as the energy recovery equipment;
is considered to be a more preferable solution.

As described above, according to the steam plant according to the present invention, the steam generating equipment, the steam using equipment including the steam turbine equipment, the energy recovery equipment, and the pressure reducing equipment are connected by a piping system. , the piping system includes a first branch to the steam turbine equipment and the steam using equipment other than the steam turbine equipment, and the piping to the steam using equipment other than the steam turbine equipment includes the energy recovery equipment and the pressure reduction. a steam control valve in at least one of the piping downstream of said first branch; a first flow meter in piping to said steam turbine equipment; and said steam turbine equipment. and a second flow meter on the upstream side of the second branch of the piping to the steam using facility other than the steam according to the flow rate of each steam branched to the downstream piping of the first branch. A valve opening adjustment mechanism that adjusts the valve opening of a control valve, and an energy recovery that controls start and stop of the energy recovery equipment in accordance with the flow rate of the steam diverted to the piping to the steam using equipment other than the steam turbine equipment. and a facility start/stop determination mechanism, wherein the valve opening adjustment mechanism is configured to obtain a value of the minimum load steam flow rate of the long-distance steam transportation pipe from a temperature compensation mechanism that adjusts according to the outside air temperature. Therefore, regardless of the amount of steam generated by the steam generating equipment and regardless of changes in the outside air temperature, it has become possible to effectively use steam, particularly to reduce loss of energy recovery opportunities.

Further, according to the steam flow rate control method according to the present invention, when distributing the steam generated by the steam generating equipment to the steam using equipment including the steam turbine equipment, the energy recovery equipment and the decompression equipment,
The degree of valve opening of a steam control valve provided on the downstream side of at least one of the first branch of the piping leading to the steam turbine equipment and the steam using equipment other than the steam turbine equipment Adjust according to each steam flow rate, control start and stop of the energy recovery equipment according to the steam flow rate to the steam using equipment other than the steam turbine equipment, and adjust the valve opening degree of the steam control valve , the value of the minimum load steam flow rate of the long-distance steam transportation pipe obtained according to the outside temperature is used, so regardless of the amount of steam generated by the steam generation equipment and regardless of changes in the outside temperature, the amount of steam It is now possible to make effective use of energy, especially to reduce the loss of energy recovery opportunities.

Furthermore, if the energy recovery facility is a steam turbine generator, energy can be recovered more efficiently.

1 is a schematic system diagram illustrating steam supply piping and a control flow of a steam plant according to one embodiment of the present invention; FIG. It is a graph showing an example of a controller output/valve opening degree conversion polygonal line of the valve opening degree adjustment mechanism used in the above embodiment. FIG. 5 is a graph showing an example of a polygonal line for temperature correction of set value of drain generation suppression flow rate of the temperature compensating mechanism used in the above embodiment. FIG. It is a graph showing an example of the change of the steam flow measured with each flow meter in the said embodiment.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic system diagram illustrating steam supply piping and a control flow of a steam plant according to one embodiment of the present invention. The steam plant 100 has a steam turbine facility 3, an energy recovery facility 4, and a pressure reducing facility 5, which are steam using facilities connected to the steam generating facility 1 by a piping system 2. Examples of the steam turbine equipment 3 include a steam turbine that drives a load such as a large rotating machine with high-pressure steam, and a mechanical drive turbine for driving a compressor. An example of the energy recovery facility 4 is a steam turbine generator in which a steam turbine is provided with a generator. In the decompression equipment 5 , the decompression valve 12 reduces the pressure to the required level and supplies it to the low-pressure steam line 51 . In FIG. 1, one system of steam generating equipment and three systems of steam using equipment are illustrated, but a plurality of steam generating equipment and other steam using equipment may be combined.

The piping system 2 is provided with a first branch 6 to the steam turbine equipment 3 and other steam using equipment (hereinafter referred to as other steam using equipment). A second branch 7 to the energy recovery facility 4 and the pressure reduction facility 5 is provided. A steam control valve 11 (in the example of FIG. 1, on the side of other steam-using equipment) in at least one of the downstream piping of the first branch 6, a first flow meter F2 in the piping on the steam turbine equipment side, and other steam. A second flowmeter F3 is provided on the upstream side of the second branch 7 of the piping on the equipment side. In addition, in the example of FIG. 1, the steam control valve 11 is provided on the other steam using equipment side, but it may be provided on the steam turbine equipment 3 side or on both sides. In addition, in FIG. 1, a steam generation facility steam flow meter F1, a steam turbine generator steam flow meter F4, and a steam pressure reducing valve steam flow meter F5 are installed.

The valve opening degree of the steam control valve 11 is calculated using the steam flow rate on the side of the steam turbine facility 3 measured by the first flow meter F2 and the steam flow rate on the side of the other steam-using facility measured by the second flow meter F3. It has a valve opening adjustment mechanism 16 that adjusts the It has an energy recovery facility start/stop determination mechanism 18 that controls the start and stop of the energy recovery facility 4 using the steam flow rate of the other steam using facility side measured by the second flow meter F3.

The valve opening adjustment mechanism 16 obtains the minimum load steam flow rate of the long-distance steam transportation pipe, which is the required minimum steam flow rate of other steam using equipment, from the temperature compensation mechanism 17 that adjusts according to the outside air temperature, It is configured such that the steam flow rate on the side of the steam using equipment is equal to or higher than the minimum load steam flow rate. Here, the minimum load steam flow rate refers to a steam flow rate at which no drain occurs in piping on the side of other steam-using equipment.

With the steam plant configured as described above, in the steam load balance between the steam generating equipment 1 and the steam using equipment, the steam generated by the steam generating equipment 1 can be distributed to the steam turbine equipment 3 such as a steam turbine that is constantly operated and the surplus steam. Energy recovery equipment 4 such as a steam turbine generator operated when is generated and other steam using equipment consisting of pressure reducing equipment 5 are distributed. When the amount of steam generated by the steam generation facility 1 is greater than the amount of steam used by the steam turbine facility 3, for example, the steam control valve 11 is opened to the side of other steam using facilities to recover energy. At this time, if the flow rate of steam flowing to the other steam-using equipment side becomes larger than the lower limit steam flow rate of the steam turbine generator 4, the steam turbine generator 4 is started, and if it becomes smaller, for example, the steam turbine generator is output from the energy recovery equipment start/stop determination mechanism 18, and the operator follows the guidance to start and stop the steam turbine generator, so that the steam turbine generator 4 can generate power, but the decompression equipment 5 It is possible to prevent the loss of the power generation opportunity by supplying steam to the In the case where the steam turbine generator 4 is a facility that can be automatically started and stopped, the output of start-stop from the energy recovery equipment start-stop determination mechanism 18 is linked and automated to further improve the accuracy and efficiency of power generation recovery. can be effectively implemented.

On the other hand, when the flow rate of steam flowing to the other steam using equipment side becomes less than the lower limit steam flow rate of the steam turbine generator 4, the pressure control of the low-pressure steam of the pressure reducing equipment 5 is operated to supply. Vapor recovery is implemented by setting the pressure control SV value slightly higher than the normal low pressure steam line pressure. When starting the steam turbine generator using the output from the energy recovery equipment start/stop determination mechanism 18, by forcibly closing the pressure reducing valve 12 of the pressure reducing equipment, the steam turbine generator 4 side Vapor recovery is preferred.

When the amount of steam generated by the steam generating equipment 1 is less than the amount of steam used by the steam turbine equipment 3, the opening degree of the flow control valve 11 of the other steam using equipment is set to the minimum value, and steam is generated to the steam turbine equipment 3 side. Recover most of the vapor. At this time, the minimum degree of opening of the flow control valve 11 is set to the degree of opening required to flow the minimum load steam amount that can suppress the generation of drain in the steam transportation pipe. The degree of opening is small in the summer when the outside temperature is high, and is widened in the winter when the outside temperature is low, thereby reducing wasteful steam flow. Therefore, the temperature compensating mechanism 17 calculates an appropriate steam flow rate setting value that does not generate drain from the outside air temperature and outputs it to the valve opening degree adjustment mechanism 16, and the valve opening degree adjustment mechanism 16 calculates that value and other steam Comparing the flow rate of steam flowing to the use equipment side, and if there is a deviation, correcting the valve opening control output of the flow control valve 11 in the direction of eliminating the deviation realizes proper valve opening control. .

Next, a steam flow rate control method using the above steam plant, which is another embodiment of the present invention, will be described.
The steam generated from the steam generation equipment 1 is distributed and supplied to the steam turbine equipment 3 , the steam turbine generator 4 as energy recovery equipment, and the pressure reduction equipment 5 via the piping system 2 .

In order to measure the steam flow rate of the line, steam flow meter F1 for steam generation equipment, steam flow meter F2 for steam turbine equipment, steam flow meter F3 for energy recovery equipment, steam turbine generator steam flow meter F4, steam pressure reducing valve steam flow meter F5 is installed, and a low-pressure steam pressure gauge P1 for measuring the steam pressure of the low-pressure steam line is installed. A PV2 value (process value), which is a signal measured by the steam turbine equipment steam flow meter F2, is input to the steam turbine equipment steam flow controller 13, and by setting the steam turbine equipment steam flow controller 13 to direct operation, When the PV2 value is lower than the SV2 value (set value), which is the threshold value, the operation output operates in the decreasing direction. Here, the SV2 value of the steam turbine facility steam flow rate controller 13 is set to the steady load value f2max (corresponding to the steam flow rate) of the steam turbine facility.

On the other hand, the PV3 value, which is the signal measured by the energy recovery facility steam flow rate F3, is input to the energy recovery facility steam flow rate controller 14, and by operating the energy recovery facility steam flow rate controller 14 in reverse, the PV3 value is lower than the SV3 value, the manipulated output operates in the increasing direction. Here, the SV3 value of the energy recovery facility steam flow rate controller 14 is set to the steam turbine generator inlet steam flow rate upper limit value f4max.

The outputs of these two controllers 13 and 14 are selected by a low-order selector LS, the lower signal is input to a controller output/valve opening conversion polygonal line 16, and the converted signal is sent to the steam turbine generator side. is output to the inlet steam control valve 11 to control the steam flow rate. FIG. 2 is a conceptual graph showing the relationship between the controller signal output and the opening of the inlet steam control valve 11 on the controller output/valve opening conversion polygonal line 16 . The conversion polygonal line secures a baseline so that the inlet steam control valve 11 does not fully close even if the output of the controller is 0%, and secures the minimum load steam amount for suppressing drain generation. Therefore, until the steam flow rate of the steam generation facility 1 reaches the steam turbine facility steady load set value SV2, the steam turbine facility steam flow rate controller 13 operates to output a downward operation signal. The opening of the inlet steam control valve 11 is adjusted to the baseline valve opening.

The baseline valve opening is normally the minimum opening specified value as the valve opening required to ensure the minimum load steam flow rate to prevent drain from occurring in the steam transportation piping of other steam-using equipment. be set. However, this value is not always constant, and in the summer when the outdoor temperature is high, it is possible to secure the minimum load steam amount with a smaller opening than in the winter when the outdoor temperature is low. For this reason, an outside air thermometer T1 is installed to measure the outside air temperature, and the measured temperature signal is input to the drain generation suppression flow rate set value temperature correction polygonal line 17 to convert it to an appropriate steam flow rate set value that matches the atmospheric temperature. FIG. 3 shows a conceptual graph of the set value temperature correction polygonal line for the set value of the drain generation suppression flow rate.

In the example of FIG. 3, the drain generation suppression flow rate set value temperature correction polygonal line 17 takes the data of the drain generation state as the relationship between the outside air temperature T and the flow rate f3 of the steam transportation pipe on the other side of the steam using equipment, and obtains an appropriate value. is preferably set. In the example of FIG. 1, the signal of the flow rate obtained from the drain generation suppression flow rate set value temperature correction polygonal line 17 is set to X, the signal of the steam flow meter F3 such as the energy recovery equipment is set to Y, and compared by the comparator C, Y≧ In the case of X, the value of the minimum opening specified value LL is adjusted downward (-) (S11). Also, if Y<X, the value of the minimum opening prescribed value LL is adjusted in the increasing direction (+) (S12). The increase or decrease in the signal due to this adjustment is achieved by increasing (+) the amount of α1 at time t1, decreasing (-) the amount of β1 at time t2, decreasing the correction amounts α1 and β1, and lengthening the correction times t1 and t2. It is preferable to keep the control from flapping. Methods other than those exemplified in FIG. 1 can also be applied to the adjustment control of the minimum opening prescribed value of the inlet steam control valve 11 based on the outside air temperature.

In addition, the period during which the adjustment control of the minimum opening specified value based on the outside air temperature is required is only the period during which the control output of the steam turbine equipment steam flow controller 13 is selected by the low-order selector LS, and the steam turbine equipment steam The signal selected by the low-order selector LS of the output of the flow rate controller 13 and the energy recovery facility steam flow rate meter 14 and the output of the steam turbine facility steam flow rate controller 13 are matched and EQed, and correction is made only when they match. The operation is activated (S13). The specified minimum load opening specified value corrected by the correction amounts of α1 and β1 passes through the upper limit HM, and is input to the controller output/valve opening conversion polygonal line 16 after being restricted so that the value does not become larger than necessary. As a result, the minimum load steam flow rate value for suppressing drain generation is corrected, and an appropriate minimum load steam flow rate corresponding to the outside air temperature is obtained.

Next, when the steam flow rate of the steam generation facility 1 increases and the measured signal PV2 value of the steam turbine facility steam flow meter F2 becomes larger than the SV2 value of the steam turbine facility steam flow controller 13, the steam turbine facility The output of the steam flow controller 13 operates in the increasing direction, the output of the energy recovery facility steam flow controller 14 is selected by the low-order selector LS, and control is switched to the energy recovery facility steam flow controller 14 .

The control of the energy recovery facility steam flow rate controller 14 opens the inlet steam valve 11 until the flow rate signal PV3 value of the energy recovery facility steam flow meter F3 reaches the steam turbine generator inlet steam flow rate upper limit value SV3. In the process, the measured value PV3 of the steam flow meter F3 such as the energy recovery equipment is input to the start/stop determination 18 of the steam turbine generator. In the steam turbine generator start/stop determination 18, for example, when the input PV3 value becomes larger than the steam turbine generator lower limit steam flow rate +γ, the steam turbine generator startup guidance is notified, and the PV3 value is When it becomes smaller than the lower limit steam flow rate of the steam turbine generator, guidance for stopping the steam turbine generator is notified to urge the operator to start and stop the steam turbine generator (S14). By doing so, it is possible to recover power generation as energy.

Of course, if the steam turbine generator can be automatically started and stopped, the output of the steam turbine generator start/stop determination 18 may be used to automatically start and stop. In that case, when the input PV3 value becomes larger than the lower limit steam flow rate +γ of the steam turbine generator, start control is performed on the steam turbine generator, and when the PV3 value becomes smaller than the lower limit steam flow rate +γ of the steam turbine generator , to stop the steam turbine generator (S14).

Also, γ is a constant for preventing control chattering, and may be a variation in the flow rate of steam supplied from the steam generation facility 1 in a steady state. Together with this operation, when the measured value PV3 of the steam flow meter F3 of the energy recovery equipment becomes larger than the lower limit steam flow rate +γ of the steam turbine generator, the operation output of the low-pressure steam pressure control controller 15 is forced to 0. %, the pressure reducing valve 12 is fully closed and steam is recovered to the steam turbine generator side. Steam is recovered to the low-pressure steam line by activating the pressure control of the steam pressure control controller 15 (S15). By setting the SV1 value of the low-pressure steam pressure control controller 15 slightly higher than the normal low-pressure steam line pressure by +β, steam recovery is performed due to the pressure difference.

A steam plant was constructed with the equipment, piping system and control system shown in FIG. 1, and steam was actually flowed from the steam generating equipment. FIG. 4 shows temporal changes in steam flow rate f1-5 measured by each flow meter F1-5.

Initially, the steam generation facility steam flow rate f1 generated from the steam generation facility 1 gradually increases with the start of operation of the steam generation facility 1, and finally reaches the average steam generation rate f1ave [t/h]. , and the operation is continued while fluctuating within the fluctuation range of ±γ [t/h]. When the operation of the steam generating facility 1 is stopped, the steam flow rate gradually decreases and finally becomes 0 t/h. In the middle of this steam increase/decrease, period A indicates an operating state in which the steam flow rate f1 of the steam generating facility is less than the steady load value of the steam turbine facility due to the steam balance.

The generated steam flows in the direction of the steam turbine equipment 3 and the energy recovery equipment 4. At this time, the inlet steam control valve 11 is opened by the minimum opening specified value, so the minimum load steam flow rate X Steam for [t/h] is secured as the other steam using equipment side steam flow rate f3. This becomes the steam for suppression of drain generation in the long-distance steam transportation pipe. In addition, since the minimum load steam flow rate X is usually smaller than the lower limit steam flow rate f4min of the steam turbine of the energy recovery facility 4, it is supplied only to the decompression facility 5 side, and the energy recovery facility side steam flow rate f4 is 0 [t/h]. becomes. After t1 when the steam generation facility steam flow rate f1 exceeds X, the incremental steam of the steam generation facility steam flow rate f1 flows as the steam turbine facility steam flow rate f2, and increases to the steam turbine facility steady load value f2max [t/h] ( t2), used with this amount of steam. The incremental steam of the further increased steam generation facility steam flow rate f1 this time increases as the steam pressure reducing valve steam flow rate f5, and increases to the lower limit steam flow rate f4min+γ [t/h] of the steam turbine generator (t3). When the valve 12 is closed and the steam pressure reducing valve steam flow rate f5 becomes 0 [t/h], the steam flows to the steam turbine generator side as the steam turbine generator steam flow rate f4, and the energy is recovered by power generation. . Assuming that the lower limit steam flow rate of the steam turbine generator is f4min [t/h], the amount of steam generated by the steam generation facility 1 is centered at f4min+γ [t/h] and is between f4min and f4min+2γ [t/h]. Set to absorb fluctuations in steam flow rate. The other steam using equipment side steam flow rate f3 is a steam amount obtained by adding the steam turbine generator steam flow rate f4 and the steam pressure reducing valve steam flow rate f5.

INDUSTRIAL APPLICABILITY The present invention is suitably applied to a steam plant in which the piping system from the steam generating equipment to the steam using equipment extends over a long distance.

100 steam plant 1 steam generation equipment 2 piping system 3 steam turbine equipment 4 energy recovery equipment (steam turbine generator)
5 pressure reducing equipment 51 low pressure steam line 6 first branch 7 second branch 11 steam control valve 12 pressure reducing valve 13 steam turbine equipment steam flow controller 14 energy recovery equipment steam flow controller 15 low pressure steam pressure control controller 16 valve open degree adjustment mechanism (controller output/valve opening degree conversion polygonal line)
17 Temperature compensating mechanism 18 Energy recovery equipment start/stop determination mechanism 20 Signal system C Comparison determination EQ Coincidence determination F1 Steam generation facility steam flow meter F2 First flow meter (steam turbine facility steam flow meter)
F3 Second flowmeter (steam flowmeter for energy recovery equipment)
F4 Steam turbine generator steam flow meter F5 Steam pressure reducing valve steam flow meter LL Minimum opening specified value LS Low selector HM Upper limit P1 Low pressure steam pressure gauge T1 Outside air temperature gauge SV1 Low pressure steam pressure +β
SV2 Steam turbine facility steady load set value SV3 Steam turbine generator inlet steam flow upper limit value

Claims (3)

A steam plant that connects a steam generating facility and a steam using facility including a steam turbine facility, an energy recovery facility and a pressure reducing facility with a piping system,
a first branch to the steam turbine equipment and steam using equipment other than the steam turbine equipment in the piping system;
a second branch to the energy recovery equipment and the pressure reducing equipment is provided in the piping to the steam using equipment other than the steam turbine equipment;
a steam control valve in at least one of the downstream pipes of the first branch; a first flow meter in the pipe to the steam turbine equipment; a second flow meter upstream from the branch,
a valve opening degree adjusting mechanism that adjusts the valve opening degree of the steam control valve according to the flow rate of each steam branched to the downstream pipe of the first branch;
an energy recovery facility start/stop determination mechanism for controlling the start and stop of the energy recovery facility according to the flow rate of the steam diverted to the piping to the steam using facility other than the steam turbine facility;
has
A steam plant, wherein the valve opening adjustment mechanism is configured to obtain a value of the minimum load steam flow rate of the long-distance steam transportation pipe from a temperature compensation mechanism that adjusts according to the outside air temperature. 2. The steam plant according to claim 1, wherein said energy recovery facility is a steam turbine generator. When distributing the steam generated by the steam generating facility to steam using facilities including steam turbine facilities, energy recovery facilities and pressure reduction facilities,
The degree of valve opening of a steam control valve provided on the downstream side of at least one of the first branch of the piping leading to the steam turbine equipment and the steam using equipment other than the steam turbine equipment Adjust according to each steam flow rate,
controlling start and stop of the energy recovery equipment according to the steam flow rate to the steam using equipment other than the steam turbine equipment;
In adjusting the valve opening of the steam control valve, using the value of the minimum load steam flow rate of the long-distance steam transportation pipe obtained according to the outside air temperature ,
A steam flow rate control method , wherein a steam turbine generator is used as the energy recovery equipment .

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