JP5230496B2 - Power generation unit - Google Patents

Description

  The present invention relates to a power generation unit and a method for starting a power generation unit.

  Conventionally, at the time of normal startup of the power generation unit, the M-BFP (motor-driven feed water pump) is started, and the auxiliary equipment of the ventilation system is started after a predetermined time (for example, after 1 minute). As auxiliary equipment of the ventilation system, two FDF (push-in blower) that blows into the boiler, two GRFs (gas recirculation blower) that blows the gas once burned from the bottom of the furnace, and the burned gas outside Are equipped with two DNFs (gas dischargers). The auxiliary equipment of these ventilation systems is controlled by a metakura board (high voltage closed switchboard).

  By the way, in the power generation unit, the longer the operation time of various large auxiliary machines, the more fuel is consumed. Therefore, conventionally, the power plant has been designed to save energy by starting and stopping the power generation unit in accordance with the power demand, for example, stopping at the weekend and starting at the beginning of the week (starting on the weekend).

JP 2004-68646 A

  However, while the power generation unit is stopped and started, the pressure of the boiler decreases. However, when the pressure of the boiler decreases, it takes time from the start of M-BFP to the establishment of water supply. However, if the time until the water supply is established is extended, the time that the ventilation system is wasted before the boiler ignition is lengthened, and the energy for driving the ventilation system may be wasted. In addition, driving the ventilation system before the boiler is filled with water may cool the boiler due to the ventilation of the ventilation system, and use extra energy to bring the boiler to an appropriate temperature.

  An object of the present invention is to solve such problems, and to provide a power generation unit and a power generation unit start method that reduce energy consumed when power generation is started and realize energy saving.

  In order to achieve the above object, the present invention has the following configuration.

The power generation unit of the present invention includes a startup system that supplies water to the boiler until the steam condition to be supplied to the steam turbine is established at the time of startup of the boiler, condenses the steam that has passed through the boiler, and returns the steam to the boiler again. A startup system auxiliary machine that performs an operation of circulating water in the startup system, a ventilation system that ventilates and exhausts the boiler, a ventilation system auxiliary machine that ventilates and exhausts the ventilation system, and the boiler Detector for detecting the temperature and pressure of the boiler, the temperature and pressure of the boiler at the start of the initial operation of the boiler, and the time from starting the auxiliary system auxiliary equipment to starting the ventilation system auxiliary equipment a memory storing the data of the corresponding relationship, the activation system accessory and a power supply control device controlling the supply of electric energy to the ventilation system accessory, the power supply control device, at the initial operation start of said boiler There wherein the detector obtains the time until activating the ventilation system accessory corresponding to the temperature and pressure of the boiler detected from data stored in said memory, said from the start of the initial operation of the boiler The ventilation system auxiliary machine is activated when time is measured .

  According to the present invention, it is possible to drive the ventilation system at an appropriate timing after the activation system auxiliary machine is activated, for example, waste due to driving the ventilation system when water supply is not established at all. Energy consumption can be suppressed and energy saving can be realized.

  According to the present invention, it is possible to drive the ventilation system at an appropriate timing after the activation system auxiliary machine is activated, for example, waste due to driving the ventilation system when water supply is not established at all. Energy consumption can be suppressed and energy saving can be realized.

1 is a block diagram showing a steam system of a boiler to which the present invention is applied. It is a block diagram which shows the ventilation system with which this invention is applied. It is a block diagram which shows the structure of the starting control apparatus in one Embodiment of this invention.

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

  FIG. 1 is a block diagram showing a startup system of a boiler. The startup system equipment includes a deaerator 10, M-BFP 12, boiler 50, a steam turbine (not shown), a flash tank 24, a condenser 30, and a condensate pump 32.

  The deaerator 10 degass the condensate from the condenser 30. The M-BFP 12 is provided in a pipe connecting the deaerator 10 and the boiler 50, and sends out water to the boiler 50. The flash tank 24 collects waste steam from the boiler 50. The condenser 30 condenses the steam obtained in the boiler 50 after use. The condensate pump 32 sends out water from the condenser 30 to the deaerator 10.

  The boiler 50 includes a water wall 13, a cage wall 14, a primary SH (superheater) 16, a secondary SH 18, and the like. The water deaerated by the deaerator 10 is sent out by the M-BFP 12, and the flow rate of the feed water sent from the M-BFP 12 is adjusted by a valve provided on the outlet side, and the water wall 13 of the boiler 50 is passed through a high-pressure heater. to go into.

  The water supplied to the boiler 50 receives and evaporates into steam when passing through the water wall 13 and the cage wall 14, becomes a predetermined steam temperature when passing through the primary SH 16 and secondary SH 18, and becomes secondary SH 18. To be supplied to the steam turbine.

  When the boiler is started, a circulation operation is performed in which the startup bypass system is used to pass the flash tank 24 and the condenser 30 and the deaerator 10 are returned to the water wall 13 again until the steam condition to be supplied to the steam turbine is satisfied. Is done. This startup bypass system is equipped with two systems, a primary SH bypass system A and a secondary SH bypass system B. First, as the initial operation, until the inlet temperature of the primary SH 16 reaches a specified temperature, the entire amount of minimum water supply is circulated through the primary SH bypass system A having the pipe 19 provided between the cage wall 14 and the inlet of the primary SH 16. I do.

  In this initial operation state, a valve (not shown) provided in the connecting pipe 17 connecting the primary SH 16 and the secondary SH 18 and a pipe 21 branched from the connecting pipe 17 and connected to the flash tank 24 are provided at predetermined positions. The secondary SH bypass valve 22 is operated in a fully closed state.

  The primary SH bypass system A in the startup bypass operation includes a pipe 19 and a primary SH bypass valve 22 provided from the flow path before the primary SH 16 in the pipe 19 to the flash tank 24, and the like. The minimum amount of water supplied is supplied to the flash tank 24 through the pipe 19 with the outlet pressure of the primary SH 16 being controlled and adjusted to be constant by the primary SH bypass valve 20.

  When the inlet temperature of the primary SH 16 reaches a predetermined value, the secondary SH bypass valve 22 is then opened, and the secondary SH bypass system B is put into operation. The start-up bypass operation is sequentially performed and the steam conditions necessary for the steam turbine are established. Operation to be made.

  Further, when the steam is supplied to the steam turbine when the boiler is started, a fluid composed of water and / or steam is passed through the flash tank 24 using the primary and secondary SH startup bypass systems A and B, and the condensate is recovered. The operation of circulating to the deaerator 1 is performed. Further, water and / or steam from the flash tank 24 is supplied to the condenser 30 via a pipe 29 provided with a flash tank water level control valve 28. Further, water and / or steam from the flash tank 24 branches from the pipe 29 and is connected to the deaerator 10, and is supplied to the deaerator 10 from the pipe 27 provided with the deaerator heating drain valve 26. .

  As described above, the two startup bypass systems start from boiler water filling and boiler pressure increase, and supply water or condensate from the flash tank 24 to the condenser 30 through the two bypass systems between the steam turbine ventilation and the steam turbine incorporation. It is a system that collects and recycles

  FIG. 2 is a block diagram showing the ventilation system of the boiler. In the present embodiment, two systems, a ventilation system A and a ventilation system B, are provided. The equipment constituting the ventilation system A includes an A-BSF (biomass slurry fuel supplier) 52A, an A-GRF 54A that blows once burned gas from the bottom of the boiler 50, an A-FDF 56A that blows air into the boiler, and a combusted gas. A-DNF 58A that exhausts gas to the outside through a chimney, a flue gas denitration device 60A that decomposes nitrogen compounds contained in the burned gas into nitrogen and water, and the like.

  Outside air is supplied into the boiler 50 in which the biomass slurry fuel is combusted by the A-FDF 56A. The combusted gas is sent to the flue gas denitration device 60A, and is supplied to the bottom of the boiler 50 by the A-GRF 54A. The gas denitrated by the flue gas denitration device 60A is drawn by the A-DNF 58A and sent to the outside through the chimney. Thus, the operation | movement which supplies external air to the boiler 50 by the ventilation system A, and exhausts the combusted gas outside is performed.

  The equipment constituting the ventilation system B is A-BSF52A, A-GRF54A, A-FDF56A, A-DNF58A, which is the equipment constituting the ventilation system B, and B-BSF52B, B which is the same equipment as the flue gas denitration device 60A. -It consists of GRF54B, B-FDF56B, B-DNF58B, flue gas denitration device 60B, etc.

  Outside air is supplied into the boiler 50 in which the biomass slurry fuel is combusted by the B-FDF 56B. The burned gas is sent to the flue gas denitration device 60B, while being supplied to the bottom of the boiler 50 by the B-GRF 54B. The gas denitrated by the flue gas denitration device 60B is drawn by the B-DNF 58B and sent to the outside through the chimney. Thus, the operation | movement which supplies external air to the boiler 50 by the ventilation system B, and exhausts the combusted gas outside is performed.

  FIG. 3 is an explanatory view showing an auxiliary machine whose power feeding is controlled by the metaclutch board. The metakura board 100 detects the pressure of the M-BFP 12, the two GRFs 54A and 54B, the two FDFs 56A and 56B, the two DNFs 58A and 58B, the temperature detector 110 that detects the temperature of the primary SH 16, and the pressure of the primary SH 16. A pressure detection device 120 is connected. Further, the metakura board 100 is provided with a cutoff circuit 130 that supplies and cuts off power to the M-BFP 12, GRF 54A, 54B, FDF 56A, 56B, and DNF 58A, 58B. Further, the metakura board 100 is provided with a CPU 140 that controls the operation of the entire metakura board 100, and a memory 150 in which various data and programs are stored.

  The memory 150 stores data on the correspondence relationship between the temperature and residual pressure of the primary SH 16 when the M-BFP 12 is activated and the activation timing of the ventilation system after the M-BFP 12 is activated. Specifically, since the time of water supply establishment by the activation system varies depending on the temperature and residual pressure of the primary SH 16 when starting the M-BFP 12, data on the time of water supply establishment corresponding to the temperature and residual pressure of the primary SH 16 is obtained. It is stored in the memory 150 as the start time of the ventilation system. In other words, the data of the start time of the ventilation system is set so that the ventilation system starts when the water supply is established.

  For example, as pattern 1, if the pressure of the primary SH 16 is 6.5 MPa or less and the temperature is 140 ° C., the ventilation system is activated 20 minutes after the M-BFP 12 is activated. As the pattern 2, if the pressure of the primary SH 16 is 8.0 MPa or less and the temperature is 170 ° C., the ventilation system is activated 10 minutes after the M-BFP 12 is activated. Such data is stored in the memory 150.

  When the CPU 140 performs control to start power supply to the M-BFP 12, the current data is stored in the memory 150 based on the detection results of the temperature detection device 110 and the pressure detection device 120. The start time of the ventilation system corresponding to the temperature and residual pressure of the primary SH 16 is acquired. Then, the CPU 140 counts the time since the power supply to the M-BFP 12 is started, and when the acquired start time is reached, the auxiliary equipment of the ventilation system, that is, two GRFs 54A and 54B, two FDFs 56A. , 56B, power supply to the two DNFs 58A, 58B is started to drive these auxiliary machines. As described above, in this embodiment, water supply is established by changing the start-up time according to the temperature and residual pressure of the primary SH 16 rather than starting the ventilation system after a certain time from starting the M-BFP 12. The ventilation system will be activated at the timing.

  As described above, according to the present embodiment configured as described above, even if it takes a long time from the start of M-BFP to the establishment of water supply due to a decrease in the pressure of the boiler, it is appropriate for the establishment of the water supply. The ventilation system can be activated at the timing. For this reason, wasteful consumption of energy for driving the ventilation system is prevented. Since the ventilation of the ventilation system is stopped while the boiler is filled with water, it is possible to prevent the boiler from being cooled by the ventilation and to prevent excessive energy from being used to bring the boiler to an appropriate temperature. The This effect is particularly remarkable in winter when the temperature is low and the boiler is easy to cool.

Specifically, when the pressure of the primary SH 16 is 6.5 MPa or less and the temperature is 140 ° C., when the ventilation system is activated immediately after the activation of the M-BFP 12, and after 20 minutes, the ventilation is performed after 20 minutes. The cost comparison with the case of starting the system is as follows.
P = √3 × 6600V × 481A × 0.85 × 10−3 × 11 yen / KW
≠ 513,000 × 0.33 (20 minutes) ≠ 17,000 That is, it is possible to reduce the cost by 17,000 per weekend start-up. For this reason, in the case of starting up 4 times / month, the annual cost reduction amount is 820,000 yen, which means that energy saving is realized.

10 Deaerator 12 M-BFP
13 Water wall 14 Cage wall 16 Primary SH
17 Connecting pipe 18 Secondary SH
19, 21, 27, 29 Piping 20 Primary SH bypass valve 22 Primary SH bypass valve 24 Flash tank 26 Deaerator heating drain valve 28 Flash tank water level control valve 30 Condenser 32 Condensate pump 50 Boiler 54A A-GRF
54B B-GRF
56A A-FDF
56B B-FDF
58A A-DNF
58B B-DNF
60A, 60B Flue gas denitration device 100 Metakura board 110 Temperature detection device 120 Pressure detection device 130 Cutoff circuit 140 CPU

Claims (1)

An activation system that supplies water to the boiler until the steam condition to be supplied to the steam turbine at the time of startup of the boiler is established, condenses the steam that has passed through the boiler, and returns the steam to the boiler again;
An activation system auxiliary machine that performs an operation of circulating water in the activation system;
A ventilation system for venting and exhausting the boiler;
A ventilation system auxiliary machine for performing ventilation and exhaust operation of the ventilation system;
A detector for detecting the temperature and pressure of the boiler;
Memory that stores data on the correspondence between the temperature and pressure of the boiler at the start of initial operation of the boiler, and the time from starting the startup system auxiliary machine to starting the ventilation system auxiliary machine,
A power supply control device that performs power supply control to the startup system auxiliary machine and the ventilation system auxiliary machine,
The power supply control device, from the ventilation system accessory the stored time to activate the memory data initial operation starts at Oite the detector of the boiler corresponding to the temperature and pressure of the boiler detected The power generation unit is characterized in that the ventilation system auxiliary device is activated when the time is measured after the acquisition and the initial operation of the boiler is started .

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