JP5659973B2 - Steam supply system, control method therefor, and steam supply method - Google Patents

Description

  The present invention relates to a steam supply system and a control method for supplying process steam from a boiler turbine power generation facility that supplies power and steam simultaneously to a factory facility, or a boiler turbine power generation facility that supplies power and steam simultaneously. The present invention relates to a method for supplying process steam to factory equipment.

  Conventionally, for example, a boiler turbine power generation facility installed in a factory facility such as a steel mill supplies the factory facility with the electric power generated by the turbine generator, and the steam generated from the boiler or the extracted steam from the turbine is supplied to the factory facility. It is branched and supplied as process steam for use.

  The amount of process steam supplied to factory equipment is appropriately controlled according to demands, but the load change rate of the boiler, which is the steam generation source, is generally several percent / minute, The rate of change in steam consumption on the demand side often exceeds the rate of change in boiler load. In this case, the change rate of the steam consumption on the demand side cannot be followed only by changing the load of the boiler.

  As an example of a method for dealing with this rapid change in steam consumption on the demand side, for example, Patent Document 1 discloses a steam extracted from a turbine 101 in a steam supply system 100 including a boiler turbine power generation facility as shown in FIG. A predetermined amount of steam corresponding to a sudden change in steam consumption is constantly discharged from the factory steam pipe 103 that supplies air to the factory equipment 102 to the condenser 105 via the bypass valve 104, for example, on the demand side. By reducing the amount of steam released from the bypass valve 104 to the condenser 105 when the amount of steam consumed at a certain factory facility 102 increases sharply, the rate of change in steam consumption will change the rate of change in load on the boiler 106. Even in such a case, a method of performing desired air supply from the air supply pipe 103 to the factory equipment 102 has been proposed.

  Further, for example, in Patent Document 2, when extracting a part of a boiler main steam system, in order to suppress a change in the amount of power generated by a turbine generator by performing the extraction, turbine power generation by an extraction flow rate is performed. It has been proposed to perform a prior control in which a reduction amount of the power generation amount at the machine is obtained and the reduction amount is added to a command value (boiler master) of the fuel input amount to the boiler.

Japanese Patent Laid-Open No. 11-343814 Japanese Patent Application Laid-Open No. 12-11003

  However, in the method of Patent Document 1, since steam that is constantly discharged to the condenser 105 is not used for power generation and causes energy loss, the power generation efficiency of the boiler turbine power generation facility decreases and the running cost also increases. To do.

  In addition, regarding the method of Patent Document 2, since the boiler has a large time constant from when fuel is supplied until steam is actually generated from the boiler, when the change in steam consumption on the demand side is large, Even if the command value for fuel input is increased, the decrease in pressure cannot be compensated immediately.As a result, the fluctuation in the pressure of the main steam system fluctuates due to extraction, and the drum level of the boiler is reduced due to this pressure fluctuation. There is a risk that the boiler will trip. In addition, even if the boiler escapes from tripping, the amount of power generated by the turbine generator changes due to pressure fluctuations in the main steam system, causing disturbance to the power transmission system, which hinders stable operation of the plant equipment as a whole. .

  Normally, in the case of boiler turbine power generation equipment, the fluctuation amount of the steam pressure must be kept within ± 8kg / cm2 of the standard set pressure. Therefore, branching on the way and supplying steam to other equipment From the point of view, it was considered undesirable.

  The present invention has been made in view of the above points, and when branching and supplying process steam from a boiler turbine power generation facility to factory facilities, an increase in facility cost and running cost is avoided, and pressure generated from the boiler is reduced. It aims at suppressing the change of the electric power generation amount of a turbine generator while suppressing a fluctuation | variation.

When the process steam is branched and supplied from the boiler turbine power generation facility to the factory facility, the inventors supply the same amount of heat as the branched steam so that the boiler can produce steam substantially equivalent to the branched steam. It was discovered that a drop in vapor pressure due to branching can be avoided by adding to the fuel input command. The present invention focuses on this point, and is a steam supply system having a steam supply system and a control device for supplying process steam from boiler turbine power generation equipment to factory equipment, and the power generation equipment is turned on. The steam supply system, comprising: a boiler that burns fuel to generate steam; a turbine that converts thermal energy of steam generated in the boiler into rotational energy; and a generator that converts rotational energy of the turbine into electric power. Is a bleed pipe for branching out a part of the steam generated from the boiler, a valve body for reducing the temperature of the steam taken out by the bleed pipe, an accumulator for storing the temperature-depressurized steam, A factory steam pipe for supplying the steam stored in the accumulator as process steam to the factory equipment, and provided in the factory steam pipe, A flow rate detection mechanism for detecting a flow rate of the process steam flowing through the factory steam pipe, and the control device supplies the factory steam pipe to the factory equipment based on the flow rate of the process steam flowing through the factory steam pipe. has been to calculate the amount of heat of the process steam, comprises a control unit to compensate for the calculated amount of heat is added to the fuel feed command to the boiler as required fuel input amount to the boiler, the control unit, the When a part of the steam generated from the boiler is branched out by the extraction pipe, the opening degree of the valve body is adjusted so as to keep the pressure upstream of the valve body constant .

  According to the present invention, since it has the extraction pipe for branching out a part of the steam generated from the boiler and the accumulator for storing the extracted steam, the accumulator functions as a buffer, and the accumulator allowable amount In this range, it is possible to supply the process steam to the factory steam pipe without branching out the steam through the extraction pipe. In other words, the supply of the process steam to the factory steam pipe can be continued regardless of the increase or decrease without increasing or decreasing the steam taken out from the extraction pipe. Then, the flow rate of the process steam flowing through the factory steam pipe is detected by the flow rate detection mechanism. Based on the detected flow rate of the process steam, the control unit calculates the heat amount of the process steam supplied from the accumulator to the factory equipment through the factory steam pipe, and the calculated heat amount is necessary for the boiler. By adding the fuel input amount to the fuel input command, the amount of steam generated from the boiler can be increased in advance before the steam is branched out from the extraction pipe. As a result, when the internal pressure of the accumulator decreases, the steam pressure generated from the boiler may decrease even if the accumulator is supplied to recover the internal pressure of the accumulator by taking out a part of the steam generated from the boiler. Absent. Ultimately, according to the present invention, it is possible to suppress the pressure fluctuation of the steam generated from the boiler when supplying the process steam to the factory equipment, and to prevent the boiler from tripping due to, for example, a decrease in the boiler drum level. Moreover, the fluctuation | variation of the electric power generation amount in a generator is also suppressed by suppressing the fluctuation | variation of the pressure of the steam generated from a boiler, and the fluctuation | variation of the quantity of the steam which flows into a turbine. For this reason, it can prevent giving a disturbance to a power transmission system by the change of the electric power generation amount by a generator, for example.

  The factory steam pipe is further provided with a pressure detection mechanism and a temperature detection mechanism for detecting the pressure and temperature of the process steam flowing through the factory steam pipe, and the controller is configured to detect the process steam flowing through the factory steam pipe. Based on the pressure, temperature, and flow rate, the amount of heat of process steam supplied from the factory steam pipe to the factory equipment may be calculated.

  The inventors subtracted the amount of steam heat obtained from the other steam source when another factory steam pipe connected to the other steam source other than the boiler is connected to the factory steam pipe. It was found that the required fuel input amount must be commanded to the boiler. In such a case, the factory steam pipe is connected to another factory steam pipe connected to a steam source other than the boiler, and the other factory steam pipe is a steam flowing through the other factory steam pipe. A flow rate detection mechanism for detecting a flow rate of the steam, and the control unit calculates a heat amount of the steam flowing through the other factory steam pipe based on a flow rate of the steam flowing through the other factory steam pipe, and the calculated heat amount May be added to the fuel injection command to the boiler as a required fuel input amount to the boiler.

  The other factory steam pipe is further provided with a pressure detection mechanism and a temperature detection mechanism for detecting the pressure, temperature and flow rate of the steam flowing through the other factory steam pipe, respectively, and the control unit is configured to control the other factory steam pipe. Calculate the amount of heat of the steam flowing through the other factory steam tube based on the pressure, temperature and flow rate of the steam flowing through the pipe, and subtract the calculated amount of heat from the calculated amount of heat of the process steam. The required fuel input amount to the boiler may be added to the fuel input command to the boiler.

Another aspect of the present invention is a method for controlling a steam supply system having a steam supply system for supplying process steam from a boiler turbine power generation facility to factory facilities, wherein the power generation facility combusts injected fuel. A boiler that generates steam; a turbine that converts thermal energy of the steam generated in the boiler into rotational energy; and a generator that converts rotational energy of the turbine into electric power, and the steam supply system includes: A bleed pipe for branching out part of the generated steam, a valve body for reducing and depressurizing the steam taken out by the bleed pipe, an accumulator for storing the depressurized and depressurized steam, and being stored in the accumulator A steam pipe for supplying the steam as process steam to the factory equipment, and the factory steam pipe provided in the factory steam pipe A flow rate detection mechanism that detects the flow rate of the flowing process steam, and calculates the amount of heat of the process steam supplied from the accumulator to the factory equipment based on the measured flow rate of the process steam. When the part of the steam generated from the boiler is branched and taken out by the bleeder pipe, the valve is The opening degree of the valve body is adjusted so as to keep the pressure on the upstream side of the body constant .

  The factory steam pipe is further provided with a pressure detection mechanism and a temperature detection mechanism for detecting the pressure and temperature of the process steam flowing through the factory steam pipe, and the pressure, temperature and the process steam flowing through the factory steam pipe are Based on the flow rate, the amount of heat of the process steam supplied from the factory steam pipe to the factory equipment may be calculated.

  The factory steam pipe is connected to another factory steam pipe connected to a steam source other than the boiler, and the other factory steam pipe is a pressure of steam flowing through the other factory steam pipe, A steam that flows through the other factory steam pipe based on the pressure, temperature, and flow rate of the steam that flows through the other factory steam pipe. The remaining amount of heat obtained by subtracting the calculated amount of heat from the calculated amount of heat of the process steam is added to the fuel input command to the boiler as the required amount of fuel input to the boiler. Good.

  The other factory steam pipe is further provided with a pressure detection mechanism and a temperature detection mechanism for detecting the pressure, temperature and flow rate of the steam flowing through the other factory steam pipe, respectively. Calculate the calorific value of the steam flowing through the other factory steam pipes based on the pressure, temperature, and flow rate, and subtract the calculated calorific value from the calorific value of the calculated process steam to give the remaining calorific value to the boiler. The required fuel input amount may be added to the fuel input command to the boiler.

According to another aspect of the present invention, there is provided a boiler that burns input fuel to generate steam, a turbine that converts thermal energy of steam generated in the boiler into rotational energy, and rotational energy of the turbine as electric power. A steam supply method for supplying process steam from a power generation facility equipped with a generator to a factory facility, branching out a part of the steam generated from the boiler, and removing the extracted steam The temperature-reduced pressure is reduced, the reduced-temperature reduced-pressure steam is stored, the stored steam is supplied as process steam to the factory equipment via a factory steam pipe, and the flow rate of the process steam flowing through the factory steam pipe is reduced. Based on the measured flow rate of the process steam, calculate the amount of heat that the process steam supplied to the factory equipment has, and compensate for the calculated amount of heat That the amount of fuel charged to the boiler, when extracting branches a part of the steam generated from the boiler, adjusting the extraction quantity of vapor to maintain the pressure of the steam generated from the boiler constant It is a feature.

  The pressure and temperature of the process steam flowing through the factory steam pipe may be further measured, and the amount of heat of the process steam supplied to the factory equipment may be calculated based on the measured pressure, temperature, and flow rate.

  The factory steam pipe is connected to another factory steam pipe connected to a steam source other than the boiler, and the flow rate of the process steam flowing through the other factory steam pipe is measured. Based on the flow rate of the process steam, the heat quantity of the steam flowing through the other factory steam pipe is calculated, and the remaining heat quantity obtained by subtracting the calculated heat quantity from the calculated heat quantity of the process steam is compensated. A fuel amount may be charged into the boiler.

  Measure the pressure, temperature and flow rate of the steam flowing through the other factory steam pipe, and calculate the heat quantity of the steam flowing through the other factory steam pipe based on the measured pressure, temperature and flow rate of the process steam. A fuel amount that compensates for the remaining heat amount obtained by subtracting the calculated heat amount from the calculated heat amount of the process steam may be input to the boiler.

  According to the present invention, when the process steam is branched and supplied from the boiler turbine power generation facility to the factory facility, the steam pressure fluctuation from the boiler due to the branch is prevented and stably supplied to the turbine generator. There is a remarkable effect that stable turbine power generation can be realized. In addition, the branching of the steam does not require special equipment, and there is a remarkable effect that the branching construction can be realized at a low cost.

It is a process flow figure showing the composition of the steam supply system containing the boiler turbine power generation equipment concerning this embodiment. It is a process flow figure showing the composition of the steam supply system containing the boiler turbine power generation equipment concerning other embodiments. It is a process flow figure showing the composition of the steam supply system containing the boiler turbine power generation equipment concerning other embodiments. It is a process flow figure showing the composition of the steam supply system containing the boiler turbine power generation equipment concerning other embodiments. It is a process flow figure showing the composition of the steam supply system containing the boiler turbine power generation equipment concerning other embodiments. It is a block diagram of the steam supply system concerning other embodiments. It is a block diagram of the steam supply system concerning other embodiments. It is a process flow figure showing the composition of the conventional steam supply system.

  Embodiments of the present invention will be described below. FIG. 1 shows a steam supply system 3 and a control device 4 that supply steam for a process used in the factory equipment 2 from the boiler turbine power generation equipment 1, the factory equipment 2, and the boiler turbine power generation equipment 1 according to the present embodiment. It is a process flowchart which shows the structure of the vapor | steam supply system 5 which becomes. In addition, in this Embodiment, although the case where coal is used as a fuel used for the boiler turbine power generation equipment 1 is demonstrated, the fuel used for the boiler turbine power generation equipment 1 is not limited to coal, for example, crude oil or The present invention can also be applied in the case of using C heavy oil, or other fuel such as LNG or by-product gas.

  The boiler turbine power generation facility 1 includes a boiler 10 that burns input fuel to generate steam, a fuel supply facility 11 that supplies fuel to the boiler 10, and main steam that is high-temperature and high-pressure superheated steam generated from the boiler 10. A turbine 12 that converts the thermal energy of the turbine 12 into rotational energy, a generator 13 that converts the rotational energy of the turbine 12 into electric power, a main steam pipe 14 that introduces main steam generated in the boiler 10 into the turbine 12, and a turbine 12. A condenser 15 for returning the steam with reduced enthalpy after work to the water and storing it as condensate, a water supply pipe 16 connecting the boiler 10 and the condenser 15, and a water supply pipe 16 are provided. The water supply pump 17 which supplies the boiler 10 with the condensate stored in 15 and the water supply control valve 18 which controls the amount of water supplied by the water supply pump 17 are provided. In the present embodiment, the boiler 10 is, for example, a circulation boiler having a drum (not shown) as an evaporator, and the turbine 12 collects the entire amount of steam that has flowed in by the condenser 15. The case will be described.

  The fuel supply facility 11 includes a coal bunker 20 that stores coal as fuel to be input to the boiler 10, a pulverized coal machine 22 that pulverizes and pulverizes coal, and a fuel input command from the control device 4. A coal feeder 21 for feeding coal from 20 to the pulverized coal machine 22 is provided. Coal that has been pulverized and pulverized by the pulverized coal machine 22 is supplied to the boiler 10 along with primary combustion air that is ventilated from a primary ventilator (not shown) to the pulverized coal machine 22 and burned in the boiler 10.

  The main steam pipe 14 is provided with a pressure detection mechanism 30 that detects the pressure of the main steam generated in the boiler, and a main steam control valve 31 that controls the flow rate of the main steam introduced into the turbine 13. The pressure detection mechanism 30 is electrically connected to the control device 4, and the pressure detected by the pressure detection mechanism 30 is input to the control device 4.

  A steam supply system 3 for supplying process steam used in the factory equipment 2 from the boiler turbine power generation equipment 1 includes a bleed pipe 40 for branching out a part of the main steam flowing through the main steam pipe 14, and a bleed pipe 40. A temperature reducing pressure reducing valve 41 which is a valve body for reducing the temperature and pressure of the extracted extracted steam, an accumulator 42 for converting the steam depressurized and depressurized by the temperature reducing pressure reducing valve 41 into hot water, and storing in the accumulator And a factory steam pipe 43 that supplies the generated steam to the factory equipment 2 as process steam used in the factory equipment 2.

  The extraction pipe 40 is connected to a predetermined position on the main steam pipe 14 downstream of the pressure detection mechanism 30 and upstream of the main steam control valve 31. The temperature reducing pressure reducing valve 41 is controlled by a steam supply system control unit 73 described later of the control device 4.

  The factory steam pipe 43 is provided with a flow rate control valve 44 that controls the supply amount of the steam stored in the accumulator 42 to the factory equipment 2. The accumulator 42 opens and closes the flow control valve 44 when, for example, the steam consumption in the factory equipment 2 fluctuates and the pressure of the extraction pipe 40 fluctuates when supplying the process steam to the factory equipment 2. It functions as a buffer for preventing repetition, and its capacity is appropriately determined according to the demand on the factory facility 2 side and the capacity of the boiler turbine power generation facility 1. Further, at a position downstream of the flow rate control valve 44 in the factory steam pipe 43, a pressure detection mechanism 45, a temperature detection mechanism 46 and a flow rate for detecting the pressure, temperature and flow rate of the process steam flowing inside the factory steam pipe 43, respectively. A detection mechanism 47 is provided. Each detection mechanism is electrically connected to a later-described steam supply system control unit 73, and the detection result of each detection mechanism is input to the steam supply system control unit 73.

  The control device 4 includes a fuel system control unit 70 that controls the amount of fuel input to the boiler 10, a water supply system control unit 71 that controls the amount of water supplied to the boiler 10, and a turbine generator control that controls the output of the generator 13. And a steam supply system control unit 73 that controls the extraction of the main steam from the main steam pipe 14 by the extraction pipe 40 and the temperature reducing pressure reducing valve 41.

  The fuel system control unit 70 controls the fuel supply amount to the boiler 10 by controlling the coal feeder 21 and adjusting the amount of coal supplied to the pulverized coal machine 22. The water supply system control unit 71 controls the amount of water supplied to the boiler 10 by adjusting the opening of the water supply control valve 18. The turbine generator control unit 72 controls the generator output by adjusting the opening of the main steam control valve 31 and controlling the amount of steam flowing into the turbine 12. During operation of the boiler turbine power generation facility 1, the fuel system control unit 70, the water supply system control unit 71, and the turbine generator control unit 72 set the electric energy in the generator 13 and the pressure of the main steam pipe 14 to a predetermined value. Thus, control is performed in a so-called boiler turbine cooperative control mode in which constant control is performed.

  Specifically, the turbine generator control unit 72 is preset with an opening degree of the main steam control valve 31 for securing a steam flow rate at which a predetermined power generation amount is obtained under a steam condition of a predetermined pressure and temperature. The opening degree of the main steam control valve 31 is adjusted based on this setting. The water supply system control unit 71 adjusts the opening of the water supply control valve 18 and controls the fuel system in order to supply the boiler 10 with water corresponding to the amount of steam generated from the boiler 10 necessary for obtaining a predetermined power generation amount. The unit 70 controls the coal feeder 21 by calculating the amount of fuel input required to superheat the feed water supplied to the boiler 10 to a predetermined temperature. As a result, an amount of steam commensurate with the flow rate of the main steam flowing into the turbine 12 is generated from the boiler 10, and the generated steam in the main steam pipe 14 is constantly controlled to a predetermined value at the power generated by the generator 13. The pressure is also controlled to a predetermined value.

  The steam supply system control unit 73 controls the flow rate control valve 44 that controls the supply of process steam to the factory equipment 2 and reduces the extraction pipe 40 that is performed in parallel with the process steam supply by the flow rate control valve 44. The temperature reducing valve 41 is controlled. In such a case, in controlling the temperature reducing pressure reducing valve 41, when the main steam is taken out from the main steam pipe 14, the influence on the output of power generation by the generator 13 and the pressure on the upstream side of the temperature reducing pressure reducing valve 41 are controlled. It is desirable to perform control that minimizes the impact. The pressure on the upstream side of the temperature reducing pressure reducing valve 41 is specifically the pressure of the main steam detected by the pressure detection mechanism 30 provided in the main steam pipe 14.

  The control in the steam supply system control unit 73 will be described in detail. When a part of the main steam is branched and extracted from the main steam pipe 14 by the extraction pipe 40 and the temperature reducing pressure reducing valve 41, the pressure of the main steam in the main steam pipe 14 is reduced by the amount that the main steam is extracted from the extraction pipe 40. . When the main steam pressure is reduced, the pressure of the steam flowing into the turbine 12 is also reduced, and the heat drop in the turbine 12 is also reduced, so that the rotational energy generated in the turbine 12 is reduced, whereby the power generation output of the generator 13 is reduced. Also decreases. In this case, the opening degree of the main steam control valve 31 controlled in the boiler turbine cooperative control mode is adjusted in the opening direction so as to keep the output of the generator 13 constant, while the fuel system control unit 70 and The water supply system control unit 71 increases the amount of fuel input and the amount of water supplied so that the pressure of the main steam pipe 14 is recovered. However, the boiler 10 has a large time constant, and the amount of steam generated immediately after the fuel input is increased. Can not. Therefore, it is impossible to follow the pressure drop of the main steam pipe 14 only by controlling the fuel input amount and the water supply amount.

  Temporarily, in order to suppress the fall of the electric power generation amount by this generator 13, it was thought that it should just increase the steam generation amount from the boiler 10 previously, for example as disclosed by patent document 1. FIG. . However, it is very lossy to always generate the maximum amount of steam taken out from the extraction pipe 40 in the boiler 10 in advance. Therefore, attention was paid to the fact that the steam pressure and temperature in the main steam pipe are very high as compared with process steam generally used in factories, and if there is an accumulator 42, it can be temporarily stored. Further, by temporarily storing steam in the accumulator 42, fuel and water supply in an amount corresponding to the amount of main steam extracted from the extraction pipe 40 are extracted from the extraction pipe 40, and the output of the generator 13 is extracted. If the steam is supplied to the boiler 10 in advance immediately after the supply of steam from the accumulator 42 to the factory equipment 2 is started, and the amount of steam generated from the boiler 10 is increased thereby, It was noted that the main steam can be taken out from the extraction pipe 40 without reducing the output of the machine 13.

  Hereinafter, the fuel supply amount required to cause the boiler 10 to generate an amount of steam commensurate with the amount of main steam taken out from the extraction pipe 40 by the steam supply system control unit 73 (hereinafter referred to as “necessary fuel input amount”). A method for obtaining the value will be described.

  Assuming that the total amount of steam taken out from the main steam pipe 14 via the extraction pipe 40 is supplied to the factory equipment 2 as process steam, the process steam supplied to the factory equipment 2 through the factory steam pipe 43. The amount of heat of the main steam and the amount of heat of the main steam extracted from the main steam amount 14 are equal. Here, the amount of heat dissipated to the outside from piping or the like, and the amount of heat of spray water brought in from outside for temperature reduction used in the temperature reducing pressure reducing valve 41 are sufficiently smaller than the amount of heat of process steam. I will ignore it.

  The amount of heat of the steam flowing through the factory steam pipe 43 can be obtained as the product of the flow rate of the steam flowing through the factory steam pipe 43 and the specific enthalpy. The specific enthalpy of steam can be obtained from a so-called steam diagram representing the specific enthalpy as a function of the pressure of steam and the temperature of steam. The steam supply system control unit 73 stores the steam diagram as data in advance, and the steam supply system control unit 73 includes a pressure detection mechanism 45 and a temperature detection mechanism 46 provided in the factory steam pipe 43. The specific enthalpy of the steam flowing through the factory steam pipe 43 is obtained on the basis of the pressure and temperature detected in step 1. Next, from the product of the specific enthalpy and the flow rate detected by the flow rate detection mechanism 47, the amount of heat of the steam flowing through the factory steam pipe 43 is calculated. The required fuel input amount for generating the amount of steam supplied to the factory equipment 2 in the boiler 10 is obtained by multiplying the amount of heat of the steam flowing through the factory steam pipe 43 by the boiler efficiency.

  The required fuel input amount obtained by the steam supply system control unit 73 is added to the fuel input command of the fuel control unit 70 when the process steam is not supplied to the factory facility 2. Thereby, an amount of steam commensurate with a decrease in the amount of power generated by the generator 13 can be generated from the boiler 10. In addition, along with the control of the fuel flow rate by the fuel control unit 70, it is necessary to control the feed water flow rate to the boiler 10 as well, but the feed water flow rate is performed by the feed water system control unit 71.

  When the amount of fuel added to the required amount of fuel is added to the boiler 10, the amount of steam generated from the boiler 10 increases and the pressure in the main steam pipe 14 increases. At this time, the opening of the temperature reducing pressure reducing valve 41 is adjusted by the steam supply system control unit 73 so as to keep the pressure of the main steam pipe 14 constant, and the main steam passes through the temperature reducing pressure reducing valve 41 opened. Steam is supplied from the tube 14 to the accumulator 42.

  The steam supply system 5 according to the present embodiment is configured as described above. Next, a method for controlling the steam supply system 5 when supplying process steam from the boiler turbine power generation facility 1 to the factory facility 2 will be described. To do.

  In the state where the boiler turbine power generation facility 1 is constantly controlling the pressure of the main steam pipe 14 and the output of the generator 13 in the boiler turbine cooperative control mode, the process steam is supplied to the factory facility 2 where the process steam is demanded. Is started, the flow control valve 44 is opened, and the hot water stored in the accumulator 42 is supplied to the factory steam pipe 43 as process steam.

  When the steam supply system control unit 73 opens the flow control valve 44 and the hot water stored in the accumulator 42 is supplied as process steam to the factory steam pipe 43, the internal pressure in the accumulator 42 decreases. Since the steam stored as hot water in the accumulator 42 functions as a buffer, the main steam is supplied from the main steam pipe 14 through the extraction pipe 40 to the factory steam pipe 43 without branching and taking out the main steam within the allowable range of the accumulator. The process steam supply can be continued. At the same time, when the process steam is supplied to the factory steam pipe 43, the detection mechanism 45, 46, 47 detects the pressure, temperature, and flow rate, and the steam supply system control unit 73 connects the factory steam pipe 43. The amount of heat that the flowing steam has is calculated. Then, based on the calculated heat amount, the steam supply system control unit 73 adds the required fuel input amount to the fuel input command of the fuel system control unit to compensate, and increases the fuel input amount to the boiler 10. Thereby, the generation amount of the main steam from the boiler 10 increases, and the pressure of the main steam pipe 14 begins to gradually increase.

  Next, when a slight pressure increase in the main steam pipe 14 is detected by the pressure detection mechanism 30 provided in the main steam pipe 14, the boiler turbine control unit 73 maintains the control in the boiler turbine cooperative control mode, and the extraction pipe The temperature reduction pressure reducing valve 43 is opened, and steam is extracted from the main steam pipe 14 through the extraction pipe 40 to the outside of the system. In other words, steam is supplied to the accumulator 42 whose pressure has been reduced, and control is performed to suppress an increase in pressure in the main steam pipe 14. As a result, the internal pressure of the accumulator 42 is also recovered.

  At this time, the increase in the amount of steam generated from the boiler 10 increased by the required fuel input amount added to the fuel input command is equal to the amount of steam consumed by the factory equipment 2 via the factory steam pipe 43. For this reason, by appropriately adjusting the opening degree of the temperature reducing pressure reducing valve 41, the pressure of the main steam pipe 14 is maintained at the same pressure as the pressure when the process steam is not consumed on the factory facility 2 side. Even if the internal pressure of the accumulator 42 is once lowered, it is restored to the original pressure. Further, since the entire amount of the increase in the amount of steam generated from the boiler 10 is extracted from the extraction pipe 40, the amount of main steam introduced into the turbine 12 through the steam control valve 31 is also maintained constant. Thereby, the fluctuation | variation of the electric power generated with the generator 13 is also suppressed.

  According to the above embodiment, since it has the extraction pipe | tube 40 which branches and takes out part of the vapor | steam generated from the boiler 10, and the accumulator 42 which stores the said taken-out vapor | steam, the accumulator 42 serves as a buffer. The steam for processing can be supplied to the factory steam pipe 43 without branching and taking out the main steam from the main steam pipe 14 via the extraction pipe 40 within the range of the allowable amount of the accumulator. In other words, the supply of process steam to the factory steam pipe can be continued regardless of the increase / decrease without increasing / decreasing the steam taken out from the extraction pipe 40. Then, the steam supply system controller 73 calculates the amount of heat of the process steam supplied from the accumulator 42 to the factory facility 2 via the factory steam pipe 43, and the calculated amount of heat is input to the boiler 10 as the required fuel. As a result, the amount of steam generated from the boiler 10 is increased in advance before the steam is branched out from the main steam pipe 14 of the boiler 10 to the extraction pipe 40. be able to. As a result, when the internal pressure of the accumulator 42 decreases, even if an amount of steam for recovering the internal pressure of the accumulator 42 is taken out from the main steam pipe 14, the pressure of the main steam pipe 14 does not decrease. Ultimately, according to the present invention, when supplying the process steam to the factory equipment 2, the pressure fluctuation of the main steam pipe 14 is suppressed, and for example, the boiler 10 is prevented from tripping due to a decrease in the drum level of the boiler 10. it can. Moreover, the fluctuation | variation of the electric power generation amount in the generator 13 is also suppressed by suppressing the fluctuation | variation of the pressure of the main steam pipe 14, and the fluctuation | variation of the quantity of the main steam which flows into the turbine 12. FIG. For this reason, it can prevent giving a disturbance to a power transmission system by the change of the electric power generation amount by the generator 13, for example.

  Conventionally, as a method of supplying process steam from boiler turbine power generation equipment to factory equipment, for example, a so-called extraction turbine of a type that performs extraction from the intermediate pressure stage of the turbine is used to supply the extracted steam from the turbine. Although the method may be used, if the extraction turbine is used to extract air from the turbine, not only the power generation output of the turbine but also the turbine efficiency is reduced and the power generation efficiency of the boiler turbine power generation equipment is also reduced. It was supposed to be. This is because the turbine is generally designed so as to obtain the highest efficiency at the normal operation point, and is operated at a point outside the normal operation point when performing bleed. In this regard, according to the above embodiment, since the extraction of the steam from the turbine 12 is not necessary when supplying the process steam to the factory equipment 2, the turbine 12 can always be operated at the highest efficiency point. In particular, since it is not necessary to consider the bleed air from the turbine 12, the turbine 12 can be set to the minimum capacity, and thus the facilities attached to the turbine 12 such as the condenser 15 and the main steam control valve 31 can be reduced. Installation costs can also be reduced.

  In the above embodiment, the case where the steam for process is supplied from the boiler turbine power generation facility 1 to the factory facility 2 has been described. In many cases, a plurality of boilers are provided. Specifically, for example, as shown in FIG. 2, a steam supply pipe 81 as another factory steam pipe connected to a steam source 80 other than the boiler 10 is connected to the factory steam pipe 43, and is connected to the factory equipment 2. The process steam is supplied by the other steam source 80 and the boiler 10 through the factory steam pipe 43. The steam supply pipe 81 is connected to the downstream side of the flow rate control valve 44 provided in the factory steam pipe 43 and downstream of the detection mechanisms 45, 46 and 47.

  The steam supply pipe 81 is provided with a flow rate control valve 82 that controls the amount of steam supplied to the factory steam pipe 43. At a position downstream of the flow rate control valve 82 in the steam supply pipe 81, a pressure detection mechanism 83, a temperature detection mechanism 84, and a flow rate detection mechanism 85 that detect the pressure, temperature, and flow rate of the steam that flows through the steam supply pipe 81 are provided. It has been. Each detection mechanism is electrically connected to the steam supply system control unit 73, and the detection result of each detection mechanism is input to the steam supply system control unit 73. In such a case, the flow rate control valve 82 provided in the steam supply pipe 81 controls the flow rate of the steam flowing through the steam supply pipe 81 to be a desired value, for example, and the flow rate control valve 44 of the factory steam pipe 43 is The pressure or flow rate of the factory steam pipe 43 is controlled to be constant so that the supply amount to the factory equipment 2 becomes a desired value.

  As shown in FIG. 2, when the steam supply pipe 81 from another steam source 80 is connected to the factory steam pipe 43, the amount of steam supplied from the other steam source 80 to the factory steam pipe 43 varies. Then, the pressure of the factory steam pipe 43 fluctuates. As a result, the amount of steam flowing from the accumulator 42 to the factory steam pipe 43 also varies. In such a case, the heat amount of the steam flowing through the steam supply pipe 81 is calculated based on the detection results of the detection mechanisms 83, 84, 85 of the steam supply pipe 81, and the heat amount of the process steam flowing through the factory steam pipe 43 is calculated. In other words, by subtracting from the amount of heat calculated from the detection results of the detection mechanisms 45, 46, 47, the difference amount of heat can be obtained as the amount of heat of the steam flowing from the accumulator 42 to the factory steam pipe 43.

  The content of the above-described control in the steam supply system 5 shown in FIG. 2 is conceptually expressed as a block diagram shown in FIG. In FIG. 6, the solid arrow indicates the flow of steam, and the dotted arrow indicates the flow of control signal. As shown in FIG. 6, a fuel input command 201 is input to the boiler 10, and steam generated from the boiler 10 flows into the turbine 12. When the steam supply from the accumulator 42 to the factory facility 2 is started, the pressure, temperature, and flow rate are detected by the detection mechanisms 45, 46, 47, and the steam flowing through the factory steam pipe 43 by the steam supply system control unit 73. The amount of heat possessed by is calculated. On the other hand, when steam is supplied from the other steam sources 80 to the factory equipment 2, the pressure, temperature, and flow rate are detected by the detection mechanisms 83, 84, 85, and the amount of heat that the steam flowing through the steam supply pipe 81 has Is calculated.

  Next, the heat quantity of the steam flowing through the steam supply pipe 81 is subtracted from the heat quantity of the steam flowing through the factory steam pipe 43, and the difference between the heat quantities is added to the fuel injection command 201 as the required fuel input quantity to the boiler 10. Thereby, the generation amount of the steam from the boiler 10 can be increased in advance. Then, by adjusting the opening degree of the temperature reducing pressure reducing valve 41 as the amount of steam from the boiler 10 increases, the pressure fluctuation of the main steam pipe 14 is suppressed, and the main steam is branched and taken out to the accumulator 42. Can be supplied. Therefore, according to the present invention, the boiler turbine power generation facility 1 can be stably operated regardless of the operation state of the steam source 80 other than the boiler 10.

  In particular, the supply of steam to the factory equipment 2 is covered by another steam source 80, and the boiler turbine power generation equipment 1 exists as an existing equipment, but between the boiler turbine power generation equipment and the factory equipment 2 4 is not provided with a facility for supplying steam, that is, when the steam supply system 3 does not exist in the flow chart shown in FIG. 4, the steam supply system 3 is added to the existing boiler turbine power generation facility 1. It is only necessary to modify a part of the control circuit of the existing control device so that the control device 4 is controlled by the existing control device, so that no special equipment is required and the steam is branched. Branch work for supply can be realized at low cost.

  When a steam source 80 other than the boiler 10 is provided as a steam supply source to the factory equipment 2 and process steam is supplied from the plurality of steam supply sources to the factory equipment 2, a system around the factory steam pipe 43 is provided. Is not limited to the example of the embodiment shown in FIG. For example, as shown in FIG. 3, a steam mother pipe 90 is provided in common with the factory steam pipe 43 and the steam supply pipe 81, and the supply of process steam to the factory equipment 2 is performed via the steam mother pipe 90. You may make it perform. In this case, the steam mother pipe 90 is provided downstream of the flow rate control valve 44 of the factory steam pipe 43 and upstream of the detection mechanisms 45, 46, 47, for example, as shown in FIG. 3. Further, the steam mother pipe 90 is provided with a pressure detection mechanism 91, and the flow rate control valve 44 controls the pressure of the steam mother pipe 90, for example, to be within a set value range. Even in such a case, the amount of heat calculated from the detection results of the detection mechanisms 83, 84, 85 is subtracted from the amount of heat calculated from the detection results of the detection mechanisms 45, 46, 47. The amount of heat corresponding to the required fuel input can be determined. When a plurality of other steam sources 80 are provided, the steam supply pipe 81 is provided for each of the plurality of other steam sources 80 based on the amount of heat calculated from the detection results of the detection mechanisms 45, 46, 47. Similarly, by subtracting the amount of heat of the flowing steam, the amount of heat corresponding to the required amount of fuel input to the boiler 10 is obtained.

  2 and 3, when another steam source 80 is provided, the steam supply pipe 81 is connected to the bleed pipe 40 upstream of the accumulator 42, for example, as shown in FIGS. It may be connected. In this case, the content of control in the steam supply system 5 is as shown in the block diagram of FIG. As shown in FIG. 7, only the point that each detection mechanism 83, 84, 85 is located upstream of the accumulator 42 is different from the case of FIG. 6, and the contents of other controls are the same as those of FIG. Omitted.

  In the above embodiment, the calorific value of the process steam supplied from the accumulator 42 to the factory equipment 2 via the factory steam pipe 43 is calculated based on the pressure, temperature, and flow rate detected by each detection mechanism. For example, the amount of heat of the steam may be calculated only from the flow rate of the process steam supplied from the accumulator 42 to the factory facility 2. In this case, the amount of heat of the process steam is calculated assuming that the enthalpy of the steam supplied as the process steam is equal to the enthalpy of the steam flowing through the main steam pipe 14. In such a case, the amount of heat of the process steam is calculated to be larger than the spray water flow rate, but the flow rate of the spray water used for temperature reduction in the temperature reducing pressure reducing valve 41 is 1-2 of the flow rate of the process steam. Therefore, the increase in the pressure of the main steam pipe 14 due to the increase in the amount of fuel input can be suppressed to a slight level.

  In the above embodiment, the case where the use of the process steam is started in the factory equipment 2 has been described, but the present invention naturally includes the factory steam 2 in the state where the process steam is used. The present invention can also be applied when the steam consumption in the facility 2 changes abruptly. In such a case, the steam supply system control unit 73 constantly monitors the amount of heat of the process steam supplied to the factory facility 2, and when the amount of heat changes abruptly, that is, when the amount of steam consumption changes abruptly, The difference between the amount of heat before the sudden change and the amount of heat after the change is obtained, and the difference amount of heat is added to the fuel input command of the fuel system control unit 70 as the required amount of fuel input to the boiler 10.

  In the above embodiment, the accumulator 42 is used as a buffer for process steam. However, for example, the diameter of the extraction pipe 40 downstream of the temperature reducing pressure reducing valve 41 is increased to function as a buffer. It may be used instead.

  In the above embodiment, the steam supply system control unit 73 determines the amount of heat of the process steam supplied from the factory steam pipe 43 based on the flow rate detected by the flow rate detection mechanism 47 provided in the factory steam pipe 43. Although the calculation is performed, the detection of the flow rate for calculating the amount of heat may be performed by providing another flow rate detection mechanism in the extraction pipe 40, for example.

  The present invention is useful when supplying process steam from boiler turbine power generation equipment to factory equipment.

DESCRIPTION OF SYMBOLS 1 Boiler turbine power generation equipment 2 Factory equipment 3 Steam supply system 4 Control apparatus 5 Steam supply system 10 Boiler 11 Fuel supply equipment 12 Turbine 13 Generator 14 Main steam pipe 15 Condenser 16 Water supply pipe 17 Water supply pump 18 Water supply control valve 20 Coal Bunker 21 Coal feeder 22 Pulverized coal machine 30 Pressure detection mechanism 31 Main steam control valve 40 Extraction pipe 41 Temperature reduction pressure regulator 42 Accumulator 43 Factory steam pipe 44 Flow control valve 45 Pressure detection mechanism 46 Temperature detection mechanism 47 Flow detection mechanism 70 Fuel System control unit 71 Water supply system control unit 72 Turbine generator control unit 73 Steam supply system control unit 80 Other steam source 81 Steam supply pipe 82 Flow rate control valve 83 Pressure detection mechanism 84 Temperature detection mechanism 85 Flow rate detection mechanism 90 Steam main pipe 91 Pressure detection mechanism 201 Basic heat input command 202 Heat input command

Claims (12)

A steam supply system having a steam supply system and a control device for supplying process steam from boiler turbine power generation equipment to factory equipment,
The power generation facility includes a boiler that generates steam by burning injected fuel, a turbine that converts thermal energy of the steam generated in the boiler into rotational energy, and a generator that converts rotational energy of the turbine into electric power. And
The steam supply system stores an extraction pipe for branching out a part of the steam generated from the boiler, a valve body for reducing and depressurizing the steam extracted by the extraction pipe, and storing the reduced and reduced steam. An accumulator, a factory steam pipe for supplying the steam stored in the accumulator as process steam to the factory equipment, and a flow rate of the process steam flowing through the factory steam pipe provided in the factory steam pipe A flow rate detection mechanism,
The control device calculates a heat amount of the process steam supplied from the factory steam pipe to the factory equipment based on a flow rate of the process steam flowing through the factory steam pipe, and the calculated heat amount is supplied to the boiler. Provided with a control unit that compensates by adding to the fuel injection command to the boiler as the required fuel input amount ,
The controller adjusts the opening degree of the valve body so as to keep the pressure upstream of the valve body constant when a part of the steam generated from the boiler is branched and taken out by the extraction pipe. A steam supply system. The front climate field steam pipe, the pressure detection mechanism and the temperature detecting mechanism for detecting the pressure and temperature of the process steam flowing through the plant steam pipe is further provided,
The control unit calculates the amount of heat of the process steam supplied from the factory steam pipe to the factory equipment based on the pressure, temperature, and flow rate of the process steam flowing through the factory steam pipe. Item 2. The steam supply system according to Item 1. The factory steam pipe is connected to another factory steam pipe connected to a steam source other than the boiler,
  The other factory steam pipe includes a flow rate detection mechanism for detecting the flow rate of the steam flowing through the other factory steam pipe.
  The control unit calculates the amount of heat of the steam flowing through the other factory steam pipe based on the flow rate of the steam flowing through the other factory steam pipe, and calculates the calculated amount of heat from the calculated amount of heat of the process steam. 3. The steam supply system according to claim 1, wherein the remaining heat amount after subtraction is added to a fuel injection command to the boiler as a required fuel input amount to the boiler. 4. The other factory steam pipe is further provided with a pressure detection mechanism and a temperature detection mechanism for detecting the pressure, temperature and flow rate of the steam flowing through the other factory steam pipe,
  The control unit calculates the amount of heat of the steam flowing through the other factory steam pipe based on the pressure, temperature and flow rate of the steam flowing through the other factory steam pipe, and uses the calculated heat amount for the calculated process. The steam supply system according to claim 3, wherein the remaining heat amount subtracted from the heat amount of the steam is added to a fuel injection command to the boiler as a required fuel input amount to the boiler. A control method for a steam supply system having a steam supply system for supplying process steam from a boiler turbine power generation facility to factory equipment,
  The power generation facility includes a boiler that generates steam by burning injected fuel, a turbine that converts thermal energy of the steam generated in the boiler into rotational energy, and a generator that converts rotational energy of the turbine into electric power. And
  The steam supply system stores an extraction pipe for branching out a part of the steam generated from the boiler, a valve body for reducing and depressurizing the steam extracted by the extraction pipe, and storing the reduced and reduced steam. An accumulator, a factory steam pipe for supplying the steam stored in the accumulator as process steam to the factory equipment, and a flow rate of the process steam flowing through the factory steam pipe provided in the factory steam pipe A flow rate detection mechanism,
  Based on the measured flow rate of the process steam, the amount of heat of the process steam supplied from the accumulator to the factory equipment is calculated,
  The calculated amount of heat is supplemented by adding to the fuel injection command to the boiler as the required fuel input heat amount to the boiler,
  When the part of the steam generated from the boiler is branched and taken out by the extraction pipe, the opening degree of the valve body is adjusted so as to keep the pressure upstream of the valve body constant, Control method of steam supply system. The factory steam pipe is further provided with a pressure detection mechanism and a temperature detection mechanism for detecting the pressure and temperature of the process steam flowing through the factory steam pipe,
  The calorific value of the process steam supplied from the factory steam pipe to the factory equipment is calculated based on the pressure, temperature, and flow rate of the process steam flowing through the factory steam pipe. Control method of steam supply system. The factory steam pipe is connected to another factory steam pipe connected to a steam source other than the boiler,
  The other factory steam pipe is provided with a pressure detection mechanism, a temperature detection mechanism and a flow rate detection mechanism for detecting the pressure, temperature and flow rate of the steam flowing through the other factory steam pipe,
  Calculate the heat quantity of the steam flowing through the other factory steam pipe based on the pressure, temperature and flow rate of the steam flowing through the other factory steam pipe, and subtract the calculated heat quantity from the calculated heat quantity of the process steam. The control method of the steam supply system according to any one of claims 5 and 6, wherein the remaining heat amount is added as a required fuel input amount to the boiler to a fuel input command to the boiler. . The other factory steam pipe is further provided with a pressure detection mechanism and a temperature detection mechanism for detecting the pressure, temperature and flow rate of the steam flowing through the other factory steam pipe,
  Calculate the heat quantity of the steam flowing through the other factory steam pipe based on the pressure, temperature and flow rate of the steam flowing through the other factory steam pipe, and subtract the calculated heat quantity from the calculated heat quantity of the process steam. The steam supply system control method according to claim 7, wherein the remaining heat amount is added to a fuel injection command to the boiler as a required fuel input amount to the boiler. A boiler that generates steam by burning injected fuel, a turbine that converts thermal energy of the steam generated in the boiler into rotational energy, and a generator that converts rotational energy of the turbine into electric power. A steam supply method for supplying process steam from power generation equipment to factory equipment,
  A part of the steam generated from the boiler is branched and taken out,
The steam taken out is depressurized and depressurized,
Storing the depressurized steam,
Supply the stored steam as process steam to the factory equipment via a factory steam pipe,
Measure the flow rate of process steam flowing through the factory steam pipe, and based on the measured flow rate of process steam,
  Calculate the amount of heat that the process steam supplied to the factory equipment has, and put the amount of fuel to compensate for the calculated amount of heat into the boiler,
A steam supply method, characterized in that, when a part of the steam generated from the boiler is branched and taken out, the amount of steam taken out is adjusted so that the pressure of the steam generated from the boiler is kept constant. Further measuring the pressure and temperature of the process steam flowing through the factory steam pipe, and calculating the amount of heat of the process steam supplied to the factory equipment based on the measured pressure, temperature and flow rate. The steam supply method according to claim 9. The factory steam pipe is connected to another factory steam pipe connected to a steam source other than the boiler,
  Measuring the flow rate of process steam flowing through the other factory steam pipes;
  Based on the measured flow rate of process steam, calculate the amount of heat of steam flowing through the other factory steam pipe,
  11. The fuel according to claim 9, wherein a fuel amount that compensates for a remaining heat amount obtained by subtracting the calculated heat amount from the calculated heat amount of the process steam is input to the boiler. The steam supply method described. Measuring the pressure, temperature and flow rate of the steam flowing through the other factory steam pipes;
  Based on the measured pressure, temperature and flow rate of the process steam, calculate the heat quantity of the steam flowing through the other factory steam pipe,
  The steam supply method according to claim 11, wherein a fuel amount that compensates for the remaining heat amount obtained by subtracting the calculated heat amount from the calculated heat amount of the process steam is supplied to the boiler.

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