JP5608784B1 - Boiler water filling method - Google Patents

Abstract

A boiler water filling method capable of reliably and efficiently filling a boiler water supply system equipment without adding new equipment to existing equipment and reducing the burden on an operator.
When performing water filling sequentially from an upstream device to a plurality of devices constituting a boiler water supply system facility, among a plurality of devices to be water filled, some of the devices in the boiler body are When water is supplied at a water supply flow rate set according to the device, the time required for the device to become full from the full blow state is registered in advance, and when the water supply to the device is started, the setting is performed. Water supply is automatically performed for the registered time at the supplied water flow rate.
[Selection] Figure 2

Description

  The present invention relates to a method for filling a boiler when starting a once-through boiler, and in particular, can reliably and efficiently fill a boiler water supply system without adding new equipment to existing equipment. The present invention relates to an appropriate boiler water filling method.

  When starting the boiler in a stopped state, it is necessary to perform water filling to fill the circulating water in the boiler. This water filling is based on the premise that the water is filled from the fully blown state, and after the time that would have taken from full blown state to full water has elapsed, open the air vent valve to check whether the boiler water is discharged. The boiler water is checked to see if it is full. For this reason, the burden on the operator is large, and time loss occurs when the boiler is started.

  In particular, in a once-through boiler, it is necessary to control the water quality, and when the prescribed water quality cannot be ensured, a blow operation for discharging the supplied boiler water is performed and the boiler water is supplied again from the full blow state. This operation is repeated until a predetermined water quality is obtained.

  Therefore, conventionally, in order to shorten the boiler start-up time, an air vent valve provided in the boiler is provided on the condition that a predetermined time has elapsed from the time when the feed water pressure and the feed water flow rate at the inlet of the boiler reach the specified values. A full water detection method at the time of boiler startup has been proposed in which the full water detection means provided on the outlet side of the air vent valve is opened to perform full water detection.

JP 2005-358393 A

However, in the above-described configuration, a full water detection means is required, and it is necessary to secure an installation space for the full water detection means or to lay a cable, which may make it difficult to add to the current apparatus. .
In particular, when water filling is performed sequentially from the upstream equipment to the multiple equipment that makes up the boiler water supply system equipment, installing full water detection means for each equipment would require installation costs and equipment There is also the inconvenience that it takes time to repair and maintain.

The present invention has been made in view of such circumstances, and without adding new equipment to existing equipment, water filling of boiler water supply system equipment can be performed reliably and efficiently, reducing the burden on the operator. The main challenge is to provide a boiler watering method that can be used.

In order to achieve the above object, a boiler water filling method according to the present invention is a boiler water filling method in which water is sequentially filled from an upstream device to a plurality of devices constituting a boiler water supply system facility, and is a water filling target. Among some devices, for some devices in the boiler body, set the water supply flow rate for each device, and when water is supplied at this water supply flow rate, the time required for the device to become full from the blown state For some devices in the boiler body, a water supply process is performed in which water is supplied for the registered time at a set water supply flow rate, and when a predetermined water quality is not obtained, a predetermined water quality is obtained. Until the water quality is obtained, the operation of repeating the blow process for discharging the supplied water and the water supply process is sequentially performed from the upstream equipment .

Therefore, when water is supplied to the boiler sequentially from the equipment upstream from the boiler water supply system, for some equipment in the boiler body, the equipment is filled with the water supply flow rate set according to the equipment. Since the water supply is automatically performed only for the time required for the operation, if the worker only performs the operation of starting the water supply, it is possible to reliably obtain a full water state without requiring facilities such as a full water detector.

  Here, as boiler water supply system equipment, when the lower path that constitutes a part of the high-pressure feed water heater, the economizer, and the furnace path is sequentially arranged downstream from the feed pump, the economizer and the lower path Alternatively, water supply may be performed by supplying water for a pre-registered time at a water supply flow rate set in accordance with each device.

In such a configuration, after the upstream economizer is water-filled in a state where a predetermined water quality is obtained (in a clean-up state), the lower path constituting a part of the furnace path has a predetermined water quality. Water filling is performed in a state where the water quality is obtained (in a cleaned state), and the water filling is performed while being sequentially cleaned up from the upstream equipment.

As described above, according to the present invention, at the time of starting the boiler, when the equipment constituting the boiler water supply system is sequentially watered from the equipment on the upstream side, the boiler body among the plurality of equipment to be water filled When water supply is started with respect to some of the devices in the device, water supply is automatically performed for a pre-registered time required until the device becomes full with the water supply flow rate set according to the device. Therefore, if the operator only performs the operation to start the water supply, it will be possible to ensure that the water filling device is fully filled, and no equipment such as a full water detector is required. The confirmation work is also unnecessary.
For this reason, it becomes possible to perform the water filling of the boiler efficiently at the time of boiler starting, reducing a burden of an operator.

FIG. 1 is a schematic configuration diagram illustrating an example of a once-through boiler. FIG. 2 is a flowchart showing an example of boiler water filling processing according to the present invention. FIG. 3 is a diagram showing the relationship between time (t) and water supply flow rate (t / h) based on the processing of the flowchart shown in FIG.

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

FIG. 1 shows an example of a feed water / steam system of a once-through boiler. Boiler feed water is pumped by a feed water pump 1 to a economizer 3 via a high pressure feed water heater 2 and heated there. Is supplied to the furnace path 4 formed on the furnace wall of the furnace body of the boiler main body 1 where it is burned and heated. The boiler feed water heated here is guided to a brackish water separator 5 through a nose part (not shown), where it is separated into water and steam, and the separated water is further led to a brackish water separation tank 6 for separating steam. The water separated in the brackish water separation tank 6 is recirculated to the economizer 3. Further, the separated steam is superheated by the superheater 7, guided to the high pressure turbine 10, and used as power for the high pressure turbine 10.

The steam after driving the high-pressure turbine 10 is guided to the reheater 11 and reheated, and then introduced into the intermediate / low-pressure turbine 12 to be used as power for the intermediate / low-pressure turbine 12. The steam after driving is guided to the condenser 13 and returned to the boiler water supply. And this boiler feed water is pumped by the feed water pump 1 to the economizer 3 again through the high pressure feed water heater 2 through the condensate demineralizer 14, the low pressure feed water heater 15, and the deaerator 16. It is like that.

The furnace path 4 is extended vertically to be connected to the lower header 21 formed of a helical pipe provided on the furnace wall, an intermediate header 22 provided in the center of the boiler, and the intermediate header 22. A plurality of upper paths 23, heated in the lower path 21, and then collected in an intermediate header (collecting pipe) 22, where water is made uniform and then supplied to the plurality of upper paths 23, High temperature and high pressure steam is generated.

In addition, the equipment from the economizer 3 to the superheater 7 is an equipment installed in the boiler body, and the water filling of the boiler refers to an operation for filling the economizer 3 to the upper path 23 with water.

  The feed water pump 1 includes a boiler feed pump (BFP) 31 and a booster pump (BFP-BP) 32 disposed upstream thereof, and is upstream of the booster pump (BFP-BP) 32. The on-off valve 33 provided on the downstream side, the on-off valve 34 provided on the downstream side of the boiler feed pump (BFP), and the downstream side of the booster pump (BFP-BP) 32, and the boiler feed pump (BFP) 31 The bypass valve 35 provided in the bypass passage controls water supply at the time of boiler startup (at the time of boiler water filling) and during steady operation.

The boiler feed pump (BFP) 31 is a pump for supplying water to the boiler in order to generate steam necessary for power generation during steady operation, and the booster pump (BFP-BP) 32 is disposed on the upstream side thereof. The deaerator 16 is a pump that raises the pressure to a required pressure because the necessary NPSH (effective suction head pressure) of the boiler feed pump (BFP) 31 cannot be secured. At the time of boiler startup, the boiler feed pump (BFP) 31 is not operated, only the booster pump (BFP-BP) 32 is operated and water is filled through the bypass valve 35. During steady operation, the boiler feed pump (BFP) ) 31 and a booster pump (BFP-BP) 32 are operated, and water is supplied through the on-off valve 34.
In addition, 36 is a cleanup valve for a economizer, and 37 is a cleanup valve for a lower path.

  The above-described boiler feed pump (BFP) 31, booster pump (BFP-BP) 32, on-off valves 33 and 34, bypass valve 35, and cleanup valves 36 and 37 are controlled by a control unit 40. The unit 40 controls the movement / stop control of the boiler feed water pump (BFP) 31 and the booster pump (BFP-BP) 32 and the feed water flow rate. The on / off valves 33 and 34, the bypass valve 35, The opening and closing operations of the cleanup valves 36 and 37 are controlled.

  In addition, 41 is a water saving operation water supply operation button that outputs a water supply start command to the economizer 3 to the control unit 40, and 42 is a economizer blow operation button that outputs a blow operation command of the economizer 3 to the control unit 40. , 43 is a lower path water supply operation button that outputs a water supply start command to the lower path 21 to the control unit 40, 44 is a lower path blow operation button that outputs a blow operation command of the lower path 21 to the control unit 40, and 45 is It is an upper path water supply operation button for outputting a water supply start command to the upper path to the control unit 40.

  In addition, the control unit 40 includes a time required for the economizer 3 to be full when the economizer 3 is supplied from a completely blown state at a predetermined water supply flow rate (200 tons per hour), and from the exit of the economizer 3 to the lower path 21. The time required to become full when water is supplied from a complete blow state (including piping between the economizer 3 and the lower path 21) at a predetermined water supply flow rate (50 tons per hour) is registered in advance.

  In FIG. 2, an operation example of performing water filling of the boiler is shown as a flowchart. Hereinafter, an operation example of water filling in the boiler body when the boiler is activated will be described based on this flowchart.

  The water filling process shown here is to perform water filling sequentially from the upstream side equipment disposed in the boiler body from the state where the inside of the boiler body is completely blown, and the high pressure feed water heater 2 is before water filling of the economizer 3. It is cleaned up (CU) in the process of and is started from a state where the high-pressure feed water heater 2 is full.

  After the cleanup of the high pressure feed water heater 2 is completed and the high pressure feed water heater 2 is in a full state, when the water saver command for the economizer 3 is issued by pressing the water saver water supply operation button 41, the control is performed. In step 50, the unit 40 closes the on-off valve 34 on the downstream side of the boiler feed pump (BFP) 31, opens the on-off valve 33 on the upstream side of the booster pump (BFP-BP) 32, and opens the bypass valve 35. (Step 50) Further, while maintaining the stopped state of the boiler feed pump (BFP) 31, only the booster pump (BFP-BP) 32 is operated, and the economizer 3 is 200 t / h (200 t / h). The booster pump (BFP-BP) is used for a predetermined time (t1) registered in advance for the economizer 3 to be fully filled with the water supply flow rate. Water carried, steps 52 to automatically stop the water supply after the predetermined time has elapsed).

  Thereafter, the water stored in the economizer 3 is collected, and it is personally checked whether or not a predetermined water quality is secured (step 54). If it is determined that the predetermined water quality is not obtained, the economizer blow operation button 42 is operated to discharge the water supplied to the economizer 3 and the economizer blow operation button 42 is operated. The clean-up valve 36 is opened until the economizer 3 is completely blown (step 56). Then, after the economizer 3 is completely blown, the economizer water supply operation button 41 is pressed again to perform water filling in step 52 again. Water filling of the economizer 3 is repeatedly performed until a predetermined water quality is obtained.

  On the other hand, if it is determined in step 54 that the predetermined water quality has been obtained, then the lower path water supply operation button 43 is pressed to fill the lower path 21 and the lower path When the water filling command of 21 is issued, the control unit 40 operates only the booster pump (BFP-BP) 32 while keeping the boiler feed pump (BFP) 31 stopped in step 58, and enters the lower path 21. On the other hand, the booster pump (BFP-BP) is used for a predetermined time (t2) registered in advance in order to fill the lower path with full water at a feed water flow rate (for example, 50 t / h) according to the lower path 21. Water is supplied, and water supply is automatically stopped after a predetermined time.

  Thereafter, the water stored in the lower path 21 is collected, and it is checked manually whether or not a predetermined water quality is ensured (step 60). When it is determined that the predetermined water quality is not obtained, the lower path blow operation button 44 is operated to perform the blow operation for discharging the water supplied to the lower path 21 to clean the lower path. The up valve 37 is opened until the lower path 21 is completely blown (step 56). Then, after the lower path 21 is completely blown, the lower path water supply operation button 43 is pressed again to perform the water filling in step 58 again. The filling of the lower path 21 is repeated until a predetermined water quality is obtained.

On the other hand, if it is determined in step 60 that the predetermined water quality is obtained, the upper path 23 is filled with water to finally fill the intermediate header 22 and the upper path 23. Water up to. The control for filling the upper path with water is performed by using a booster pump (BFP-BP) 32 and a bypass valve 35 as in the case of the water saving of the economizer 3 and the lower path 21, and here the water is not filled by the flow rate regulation. Then, the bypass valve 35 is filled with a specified opening (about 300 t / h), and the presence or absence of full water is determined on the condition that the brackish water separation tank 6 has reached the specified level.

Therefore, when the above water filling process is shown over time, it is as shown in FIG. 3, and in the water saving of the boiler body economizer 3 and the lower path 21, the water supply flow rate corresponding to each device is filled with water. Water supply is performed for a predetermined time (t1, t2) set in advance, and the water supply automatically stops after the predetermined time has elapsed, so that a facility such as a full water detector is not necessary, The person does not need to go to the site to check whether the economizer 3 or the lower path 21 is full.
For this reason, it becomes possible to perform the water filling of the boiler at the time of boiler starting efficiently, reducing the burden on an operator, and it becomes possible to shorten the time of a water filling process.

3 economizer 4 furnace path 21 lower path 23 upper path 40 control unit

Claims (2)

A boiler water filling method of performing water filling for a plurality of devices constituting the boiler water system equipment,
For some of the devices that are subject to water filling, for some devices in the boiler body, set the water supply flow rate for each device and when the water is supplied at this water supply flow rate until the device becomes full from the blown state Register the time required for
For a part of equipment in the boiler body, when a predetermined water quality is not obtained by performing a water supply process of supplying water for the registered time at a set water supply flow rate, until a predetermined water quality is obtained A boiler water filling method characterized by sequentially performing an operation of repeating a blow process for discharging the supplied water and the water supply process from upstream equipment .   The boiler feed water system facility has a lower path constituting a part of a high pressure feed water heater, a economizer, and a furnace path on the downstream side from a feed water pump, and some equipment in the boiler body The boiler water filling method according to claim 1, wherein the boiler is a charcoal unit and the lower path.

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