JP5191274B2 - Water supply system in steam power generation facilities - Google Patents

Description

The present invention utilizes the thermal energy relates to steam power generation facility that generates power by the turbine, relates to a water-based integrated in steam power generation facility for supplying water to particularly use as a turbine steam and cooling water in once-through boiler.

  Steam power generation equipment is equipment that burns fuel in a boiler, generates high-pressure and high-temperature steam with its heat, and generates electricity by rotating a steam turbine and a generator. Steam power generation facilities that rotate turbines with high-temperature and high-pressure steam obtained by burning fuel in this boiler account for an overwhelmingly high proportion of both power generation capacity and power generation in thermal power generation.

  Steam power generation equipment is composed of various auxiliary equipment in addition to main equipment such as boilers, turbines, and generators. When these facilities are classified by function, they are composed of fuel receiving / storage facilities, boiler facilities, steam turbine facilities, condensate / water supply system facilities, generators and electrical facilities, and measurement control devices and facilities. Here, the fuel receiving / storage facility is a trading metering device, a fuel tank such as heavy crude oil, LNG, or LPG, a fuel oil pump, an LNG pump, a vaporizer, or the like. The boiler equipment includes a boiler body, heavy crude oil pump, burner, ventilator, air preheater, dust collector, ash treatment device, and chimney. The steam turbine equipment includes a turbine body, a lubricating oil device, a speed governor, and the like. Condensate / water supply system facilities include condensers, circulating water pumps, condensate pumps, feed water heaters, feed water pumps, and feed water treatment equipment. Generators and electrical equipment are generators, exciters, transformers, switchgears, cables, and the like. The measurement control device includes various measurement devices, a monitoring device, a plant general control device, an automatic burner device, and a computer control device. The facilities include on-site cooling water equipment, on-site air equipment, wastewater treatment equipment, and safety and disaster prevention equipment.

  It is desirable that the water used in the power generation equipment is of good quality. Usually, industrial water or river water is used. This water is temporarily stored in the raw water tank. The raw water is turbidized and filtered by a water treatment device and used as water for power generation facilities. Boiler water requires high-quality water and is processed by a pure water device. The pure water device removes calcium, magnesium, silica and other salts present in the water. If poorly treated water is used, the boiler and tube will become dirty, impeding heat conduction, causing corrosion and causing an accident.

  Next, the treated water is once stored in a pure water tank, and is then replenished to the condenser. Condensate accumulated in the hot well at the bottom of the condenser is pumped up by the condensate pump, heated by the low-pressure feed water heater, and enters the deaerator. The deaerator is degassed by a device that removes dissolved oxygen in the condensate, pressurized to a required pressure by a boiler feed pump, and enters the boiler through a high-pressure feed water heater.

The operation of the water supply system of such a steam power generation facility is very complicated. In view of this, an automatic control method has been proposed in which an automatic control device is used to perform all the driving operations that have been relied on human intuition so far. For example, as shown in Japanese Patent Application Laid-Open No. 11-237004 (Patent Document 1) of Japanese Patent Application Laid-Open No. 11-237004, a single water supply pump in which the water discharged from each water supply booster pump is independent from the main water supply system. First and second feed water pump bypass valves for supplying to the bypass system, and feed water flowing through the feed water pump bypass system on the downstream side of the first and second feed water pump bypass valves to the main feed water system on the downstream side of the feed water pump In a feed water pump system comprising a feed water circulation valve to be supplied, a control device for generating a control signal for opening and closing the first and second feed water pump bypass valves is provided, and the control device provides the first and second feed water pump bypasses. When a fully closed position signal detected by the feedwater pump bypass valve that is not related to cleanup operation is input, Feed water pump system control apparatus characterized by comprising a circuit for outputting a signal to the water supply pump bypass valve is opening operation used in the up operation has been proposed.
JP-A-11-237004

  Thus, in steam power generation equipment, electricity cannot be generated immediately by igniting the boiler, and the time required for the steam power generation equipment depends on the state of the stopped motor compared to hydroelectric power generation equipment or internal combustion power generation equipment. Although different, there was a problem that it took more than ten hours to take a predetermined load.

  Patent Document 1 does not control operation of the entire water supply system safely and accurately using only an apparatus related to automatic control of the water supply pump. For example, when a water supply pump is driven without warming up to each device, that is, when water is supplied without heating around the pump, there is a problem that each device is likely to break down or crack.

  In addition, in the water supply system, if water that has not been treated sufficiently is used, dirt will adhere to the boilers and piping, etc., hindering heat conduction and causing corrosion of the power generation equipment. It was.

The present invention has been developed to solve such problems. In other words, the object of the present invention is to finely adjust the temperature of water supplied to equipment such as a boiler so that it can be operated safely and accurately at the time of starting and stopping of the power generation equipment, and also in the event of an abnormality. to provide a water supply system integrated in the steam power generation facility that can respond appropriately.

  The water supply system of the present invention is a water supply system in a steam power generation facility that supplies water used as turbine steam or cooling water in a steam power generation facility, and water that has been treated so that it can be used as water for power generation facilities. ), Pumped by the condensate pump (5), heated by the low-pressure water heater (6) to remove dissolved oxygen, and heat the condensate using steam extracted from the steam turbine (7). A steam turbine drive pump (9) for pressurizing the water deaerated by the air vent (1) and the deaerator (1) to a pressure during normal operation and supplying water to the boiler (8); Or, in an emergency, it is provided between a motor-driven pump (10) that pressurizes to a required pressure and supplies water to the boiler (8), and the motor-driven pump (10) and the steam turbine-driven pump (9) downstream thereof. Before and after The water pressure adjusting valve (13) for adjusting the pressure difference of water to be heated, and the water pressurized by the steam turbine drive pump (9) and the motor drive pump (10) are heated and supplied to the boiler (8). A high pressure feed water heater (3), and a top-up valve (14) for feeding water to the high pressure feed water heater (3) from between the steam turbine drive pump (9) and the motor drive pump (10). Features.

  The high-pressure feed water heater (3) is preferably provided with an economizer (12) that preheats feed water using the exhaust heat of the boiler (8).

  In the invention of the above configuration, the feed water pump (2) pressurizes the degassed water to a required pressure during normal operation, and supplies a feed water to the boiler (8), and a steam turbine drive pump (9), It consists of a motor-driven pump (10) that pressurizes to a required pressure during start-up or emergency, and supplies water to the boiler (8), so that it operates safely and accurately when the power generation equipment is started and stopped. In addition, it is possible to appropriately cope with the abnormal operation by operating the feed water flow rate adjusting valve (13) or the topping up valve (14).

  Since the economizer (carbon-saving device) (12) which preheats feed water using the exhaust heat of a boiler (8) was attached to the high pressure feed water heater (3), it can heat efficiently.

The water supply system in the steam power generation facility of the present invention supplies the water treated with raw water to the condenser, pumps it with a condensate pump, heats it with a low-pressure water heater, removes dissolved oxygen, and extracts steam extracted from the turbine. A deaerator that heats the condensate using water, a water supply pump that pressurizes the water deaerated by the deaerator, and a high-pressure water heater that heats the water pressurized by the water pump and supplies it to the boiler And a water supply system.
The method of operating the water supply system, to use as a turbine steam and cooling water in the steam power generation facility, the water of dissolved oxygen water removed by the deaerator, when the differential pressure is low before and after the feed water flow regulating valve This is a method of operating a water supply system in which the high pressure water heater is supplied as it is, and conversely, when the differential pressure before and after the water supply flow rate adjustment valve is high, water is gradually supplied to the high pressure water heater using a topping up valve.

Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic system diagram showing a water supply system in the steam power generation facility of the present invention.
The fuel system of the present invention is a system that supplies water used as turbine steam or cooling water in a steam power generation facility, and mainly includes a deaerator 1, a feed water pump (BFP) 2, and a high-pressure feed water heater 3. Equipment. Raw water such as industrial water and river water stored in the raw water tank is turbidized and filtered by a water treatment device (not shown) so that it can be used as water for power generation facilities. This is because if poorly treated water is used, dirt will adhere to the boiler 8 and piping, etc., hindering heat conduction, causing corrosion and causing an accident in the power generation facility.
Furthermore, after turbidity and filtration treatment, it is desirable to remove calcium, magnesium, silica and other salts and dissolved ions present in the treated water with a pure water device (not shown).

  The deaerator 1 supplies treated water to the condenser 4, pumps it up with the condensate pump 5, heats it from about 120 ° C. to about 150 ° C. with the low-pressure feed water heater 6, removes dissolved oxygen, and removes the steam turbine 7. It is an apparatus that heats the condensate using steam extracted from. In this deaerator 1, the extracted water of the steam turbine 7 is injected to directly heat the feed water, and the dissolved gas in the feed water is physically removed.

  The feed water pump 2 is a device that pressurizes water deaerated by the deaerator 1 to a required pressure. The feed water pump 2 pressurizes the deaerated water to a required pressure during normal operation, and supplies a steam turbine drive pump (T-BFP) 9 for supplying feed water to the boiler 8 and is required at the time of start-up or emergency. And a motor drive pump (M-BFP) 10 for supplying water to the boiler 8.

  Before the feed water pump 2 is started, only the motor-driven pump (M-BFP) 10 is preheated using a deaerator circulation pump (DCP) 11. The steam turbine drive pump 9 is warmed after the motor drive pump 10 is started, for example, after a BFP warming valve is opened. There are two types of warming valves, an M-BFP warming valve and a BFP warming valve. It is desirable that the motor-driven pump (M-BFP) 10 is preheated by refluxing hot water of about 90 ° C. At DSS (daily start / stop) start-up, WSS (weekend start-up stop) start-up and the like have a long stop time, so the temperature drops from about 90 ° C.

  The high-pressure feed water heater 3 is a device that heats the water pressurized by the feed water pump 2 to a predetermined temperature and supplies it to the boiler 8. The high-pressure feed water heater 3 heats feed water with turbine bleed air or other steam. In order to efficiently heat the high-pressure feed water heater 3, it is desirable to attach an economizer (a economizer) 12 that preheats the feed water using the exhaust heat of the boiler 8.

FIG. 2 is a flowchart showing the operation method of the water supply system in the steam power generation facility of the second embodiment.
The operation method of the water supply system according to the second embodiment is as follows. First, treated water that has been turbidized and filtered by a water treatment device is supplied to the condenser 4 so that it can be used as power generation facility water. Pump up and heat from 50 ° C. to 120 ° C. with the low pressure water heater 6, put into the deaerator 1, and remove the dissolved oxygen in the condensate with this deaerator 1, at this time the water temperature of the feed water is 120 ° C. to 150 ° C. It will be about. The deaerated water is pressurized to a required pressure by the boiler feed pump 2 and supplied to the boiler 8 through the high-pressure feed water heater 3.

  Next, when there is no differential pressure before and after the feed water flow rate adjustment valve 13, the water from which dissolved oxygen in the water is removed by the deaerator 1 is supplied to the high pressure feed water heater 3 as it is and heated to about 150 ° C to 240 ° C. To do. If the boiler 8 has a residual pressure when it trips, the topping up valve 14 is not operated, and the water supply flow rate adjusting valve 13 is suddenly filled. When the feed water flow rate adjustment valve 13 can be controlled to withstand a differential pressure exceeding 9.8 MPa, it is not necessary to provide a topping up valve even if there is a differential pressure.

In addition, when the feed water flow rate adjustment valve 13 cannot be controlled to withstand a differential pressure exceeding 9.8 MPa, it is preferable to gradually supply water to the high pressure water heater 3 using the topping up valve 14. For example, when performing an “open” operation on the topping up valve 14, the outlet pressure of the primary boiler 8 is 9.8 MPa or less, and the motor-driven pump 10 is started.
When the outlet valve of the motor-driven pump 10 is “opened”, when the outlet pressure of the primary boiler 8 is 9.8 MPa or more (when the outlet pressure setting of the primary boiler 8 is 15.5 MPa) and the outlet valve is fully opened, The flow rate adjusting valve 13 becomes automatic and starts to open.

  Before starting the feed water pump 2, the deaerator circulation pump 11 is used to recirculate and preheat hot water at the time of starting the DSC (daily start / stop) of 90 ° C. to the motor-driven pump 10 to make each device safe. Can drive to. That is, the deaerator circulation pump 11 is started in a state where the feed water temperature is lowered to about 90 ° C. when the deaerator circulation pump 11 is started in order to eliminate a temperature difference during operation.

  Further, when the casing temperature of the feed water pump 2 is cooled to 40 to 50 ° C. from the feed water temperature by sealing water or the like, the deaerator circulation pump 11 is activated and preheated for the feed water pump 2. That is, the deaerator circulation pump 11 is activated when the outlet temperature difference of the deaerator 1 is plus or minus 40 degrees or more, and is stopped when the outlet temperature difference falls within this temperature range. This is because there is a temperature difference limitation that the casing of the feed water and the feed water pump 2 is within 40 ° C. with respect to the start condition of the feed water pump 2, so that the temperature difference is eliminated by starting and preheating the deaerator circulation pump 11. .

  In the present invention, the temperature of water supplied to equipment such as the boiler 8 is finely adjusted, so that the power generation equipment can be operated safely and accurately at the time of starting and stopping, and is also appropriate in the event of an abnormality. Of course, the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the present invention.

Water-based integrated in steam power generation equipment of the present invention can be utilized such as the addition to the combined cycle power plant of steam power generation equipment.

It is a schematic system diagram which shows the water supply system in the steam power generation equipment of this invention. It is a flowchart explaining the operation method of the water supply system in a steam power generation equipment.

DESCRIPTION OF SYMBOLS 1 Deaerator 2 Water supply pump 3 High pressure feed water heater 4 Condenser 5 Condensate pump 6 Low pressure feed water heater 7 Turbine 8 Boiler 9 Steam turbine drive pump 10 Motor drive pump 11 Deaerator circulation pump 12 Economizer
13 Water supply flow adjustment valve 14 Topping up valve

Claims (2)

A water supply system in a steam power generation facility that supplies water used as turbine steam or cooling water in a steam power generation facility,
Water that has been treated for use as power generation facility water is supplied to the condenser (4), pumped by the condensate pump (5), heated by the low-pressure feed water heater (6) to remove dissolved oxygen, and steam turbine A deaerator (1) for heating the condensate using the steam extracted from (7);
The water deaerated by the deaerator (1) is pressurized to the pressure during normal operation, and the steam turbine drive pump (9) for supplying water to the boiler (8), and at the required pressure during startup or emergency A motor-driven pump (10) that pressurizes and feeds water to the boiler (8);
A water supply flow rate adjusting valve (13) provided between the motor-driven pump (10) and the steam turbine-driven pump (9) downstream of the motor-driven pump (10) for adjusting the differential pressure of water before and after the pump;
A high-pressure feed water heater (3) for heating and supplying water pressurized to the steam turbine drive pump (9) and the motor drive pump (10) to the boiler (8);
A water supply in a steam power generation facility comprising a top-up valve (14) for supplying water to the high-pressure water heater (3) from between the steam turbine drive pump (9) and the motor drive pump (10) system.   The steam generator system according to claim 1, wherein an economizer (12) for preheating water supply using exhaust heat of the boiler (8) is attached to the high-pressure water heater (3). Water supply system.

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