JP2009168379A - Power generation system and control method of water supply system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a power generation system and a control method of a water supply system attaining the normal and safe maintenance and management of the whole facility by easily reducing the load of the water supply system in carrying out power generation and the load of each equipment in controlling the water supply system. <P>SOLUTION: The power generation system is provided with a combustion system comprising a turbine driven by the supply of steam from a boiler; a condensation system comprising a condenser for condensing steam used in the turbine; a deaeration system comprising a deaerator for deaerating a condensate condensed by the condenser to supply water; a water supply system provided between the deaeration system and the combustion system and comprising a motor driving water supply system 41 having a motor driving water supply pump 411 driven by a motor, and a turbine driving water supply system 42 having a turbine driving water supply pump driven by a turbine; and a control means for controlling each passage formed in the water supply system. The control means closes a valve 415 installed at an intermediate part of a passage 420 formed by joining the turbine driving water supply system 42 through the motor driving water supply pump 411 based on a start command when starting the motor driving water supply pump 411. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a power generation system that generates power using various combustion apparatuses such as a boiler and a turbine as a heat source, and a control method for a water supply system.

  Conventionally, when maintaining and managing various facilities such as a power plant, various measures have been adopted to reduce the occurrence of failures and malfunctions of equipment in the facilities. For example, there is a water supply pump warm-up method (see Patent Document 1) for setting a water supply pump in a resting state to a standby state where it can be urgently started. According to such a method, the process of warming the water supply pump is taken in, and the temperature of the water supply staying in the pipeline is effectively reduced and controlled below the specified temperature, thereby reducing the water hammer and the cavity. Without generating, it is possible to keep the water supply pump in a standby state where it can be started immediately.

  However, in the method of Patent Document 1, since the warming valve is opened and closed according to the temperature, it is necessary to always manage the temperature of the feed water in the feed water pump suction pipe, complicated control and modification of equipment It took time and effort.

JP 10-300013 A (Claims etc.)

  In view of such circumstances, the present invention can easily reduce the burden on each of the water supply system when generating power and each device when controlling the water supply system, and can maintain and manage the entire facility normally and safely. It aims at providing the control method of a water supply system.

  In order to achieve the above object, a first aspect of the present invention includes a combustion system that includes a turbine that is driven by steam supply from a boiler, and a condensate system that includes a condenser that condenses the steam used in the turbine. A deaeration system comprising a deaerator for degassing the condensed water condensed in the condenser and supplying water, and a motor drive provided between the deaeration system and the combustion system and driven by a motor A water supply system including a motor-driven water supply system including a water supply pump and a turbine-driven water supply system including a turbine-driven water supply pump driven by a turbine, and a control unit that controls each flow path configured in the water supply system. The control means is configured to merge with the turbine drive water supply system via the motor drive water pump based on a start command when starting the motor drive water pump. In the power generation system characterized in that so as to close the valve which is installed in the middle of that channel.

  In such a first aspect, it is installed in the middle of the flow path configured by joining the turbine-driven water supply system via the motor-driven water supply pump based on the start command when starting the motor-driven water supply pump. Close the valve. Thereby, since the path | route which warms up the water pump for motor drive is interrupted | blocked, the backflow to a turbine drive water supply system can be prevented.

  According to a second aspect of the present invention, the motor-driven water supply system further includes a bypass flow path including a circulation pump that pumps water supplied from the deaeration system, and the deaeration system when the turbine is not driven. The power generation system according to the first aspect is configured such that the feed water from the water circulates through the bypass flow path.

  In the second aspect, when the turbine is not driven, the water supply from the deaeration system circulates through the bypass flow path. As a result, a flow path is formed in which the feed water from the deaeration system circulates in accordance with various pump operations, pressure differences in the pipelines generated according to valve opening / closing control, and the like.

  According to a third aspect of the present invention, the turbine-driven water supply system is composed of two systems, and each system is configured to be connected to the motor-driven water supply system, respectively. In the power generation system.

  In the third aspect, control can be performed while appropriately selecting a device to be driven according to the state of the facility and the purpose of maintenance.

  According to a fourth aspect of the present invention, a part of the flow path constituting the turbine-driven water supply system is formed including a circulation flow path that circulates in the water supply system via the motor-driven water supply pump. The power generation system according to any one of the first to third aspects is characterized.

  In this 4th aspect, a part of flow path which comprises a turbine drive water supply system can be used as a part of the path | route at the time of warming a water pump for motor drive. For this reason, according to the objective of maintenance, the whole installation can be controlled easily and at low cost.

  According to a fifth aspect of the present invention, power is generated by a turbine driven by supply of steam generated by a boiler, the steam used in the turbine is condensed by a condenser to be condensed water, and the condensed water is degassed by a deaerator. In a power generation system in which deaeration treatment is performed to supply water and the water is recirculated from the turbine to the boiler, before the water supplied from the deaerator is supplied via the motor-driven water pump, the water is supplied via the turbine-driven water pump. A method for controlling a water supply system is characterized in that a part of a circulating flow path is blocked.

  In the fifth aspect, since the pressure applied to the flow path connected to the turbine drive water pump side can be reduced, useless operation of equipment installed in the system including the turbine drive water pump is prevented. can do.

  ADVANTAGE OF THE INVENTION According to this invention, the electric power generation system and water supply system which can reduce easily the burden of each apparatus at the time of controlling the water supply system at the time of power generation and a water supply system, and can maintain the whole installation normally and safely A control method can be provided.

  Hereinafter, the best mode for carrying out the present invention will be described. The description of the present embodiment is an exemplification, and the present invention is not limited to the following description.

  FIG. 1 is a schematic diagram of a power generation system according to the present embodiment. In the present embodiment, it is assumed that the present invention is applied to a thermal power plant that generates power using various combustion devices such as a boiler and a turbine as a heat source.

  As shown in FIG. 1, the power generation system 1 mainly includes a water supply system 40 including a combustion system 10, a condensate system 20, a deaeration system 30, and a motor-driven water supply system 41.

  The combustion system 10 includes various turbines 11 and 13 to 15 that are driven by steam supply from the boiler 12. The various turbines 11 and 13 to 15 are a high pressure turbine 11 driven by main steam supplied from the boiler 12, an intermediate pressure turbine 13 driven by reheat steam supplied from the boiler 12 via the high pressure turbine 11, and an intermediate pressure turbine. 13 comprises low-pressure turbines 14 and 15 driven by steam supplied from 13, each of which is coaxially connected in series. A generator 16 for generating power is installed on the same axis. In the present embodiment, the generator 16 is installed so as to be directly connected to each of the high-pressure turbine 11 and the low-pressure turbine 15.

  The condensate system 20 includes a condenser 21 that condenses the steam used in the low-pressure turbine 15, and connects the downstream side of the combustion system 10 and the upstream side of the deaeration system 30 to condense the steam. As shown, each pipe line, a valve, a pump, etc. (hereinafter referred to as a flow path configuration) for flowing into a predetermined device are included. In addition, it does not specifically limit about a specific flow-path structure, For example, any of the structure employ | adopted in the general plant and the structure after remodeling may be sufficient.

  The deaeration system 30 includes a deaerator 31 that degasses the condensate condensed in the condenser 21 and supplies water, and a space between the downstream side of the condensate system 20 and the upstream side of the water supply system 40 is provided. Each pipe line, valve, pump, etc. (hereinafter referred to as a flow path configuration) for connecting and allowing condensate to flow into a predetermined device as feed water are configured. Similar to the condensate system 20 described above, the specific flow path configuration is not particularly limited, and may be, for example, a configuration employed in a general plant or a configuration after remodeling.

  The water supply system 40 is provided between the deaeration system 30 and the combustion system 10 and is driven by a turbine in addition to a motor-driven water supply system 41 (M-BFP system) including a motor-driven water supply pump driven by a motor. A turbine drive water supply system (T-BFP system; not shown) including a turbine drive water pump is connected in parallel. Although the specific configuration of the main part will be described later, the configuration other than the main part is not particularly limited as in the case of the condensate system 20 and the deaeration system 30, and the configuration and modification adopted in a general plant. Any of the configurations after this may be used.

  The flow path configurations of the systems 10 to 40 described above are controlled by control means (not shown). As such a control means, as long as it has a function which can control the operation | movement of the whole or a part of installation based on a predetermined | prescribed input signal or an output signal, the structure will not be ask | required. In this embodiment, what is necessary is just to be able to control at least the water supply system 40, and of course, it may be possible to control each system 10 to 40 as a whole.

  The systems 10 to 40 as described above are sequentially connected to form a predetermined flow path, so that power is generated by the various turbines 11 and 13 and the generator 16 that are driven by the supply of steam generated by the boiler 12. The steam used in the various turbines 11 and 13 to 15 is condensed in the condenser 21 to be condensed water, the condensed water is degassed in the deaerator 31 to be supplied water, and the supplied water is supplied from the low pressure turbine 15 to the boiler. A power generation system 1 that recirculates to 12 is configured.

  Drawing 2 is a lineblock diagram showing the important section of the water supply system concerning this embodiment.

  As shown in FIG. 2, the deaerator 31 is connected to a deaerator water storage tank 32 that stores the deaerated water, and is configured in the water supply system 40 via the deaerator water storage tank 32. It is connected to the motor drive water supply system 41 (M-BFP system). The motor-driven water supply system 41 is connected to a turbine-driven water supply system 42 (T-BFP system), and its downstream side is connected to a combustion system 10 including a high-pressure turbine 11 and a boiler 12. Here, in the present embodiment, the motor-driven water supply system 41 is composed of one system, each turbine-driven water system 42 is composed of two systems, and the turbine-driven water system 42 is connected to the motor-driven water system 41, respectively. Configured.

  Specifically, the downstream side of the deaerator water storage tank 32 is connected to one inflow port of the booster pump 410 (M-BFP-BP), and the other inflow port is a water pump for driving the motor 411 (M- BFP) is connected to one inlet. The other inlet of the motor-driven water supply pump 411 is connected to the boiler 12.

  Between the motor driving water supply pump 411 and the booster pump 410, a fluid coupling 412 and motors 413 and 414 are connected in series starting from the motor driving water supply pump 411. Thereby, the booster pump 410 is driven by the motor 414, and the water pump for driving the motor 411 is driven by the motor 413 through the fluid coupling 412.

  The motor-driven water supply pump 411 is connected to the turbine-driven water supply system 42 via a warming valve 415, and the warming valve 415 is opened and closed to supply water to the motor-driven water supply pump 411 side. Or is introduced into the turbine drive water supply system 42 side. In other words, when the warming valve 415 is open, the flow path that flows into the motor-driven water supply pump 411 side depends on the pressure difference in the pipe line caused by the operation of various pumps or valve opening / closing control. It is formed. A part of the flow path connecting the motor-driven water supply pump 411 and the booster pump 410 branches to join the flow path connecting the warming valve 415 and the turbine-driven water supply system 42. With such a configuration, a circulation flow path 420 that can be circulated through the motor driving water supply pump 411 is formed, and the motor driving water supply pump 411 can be warmed. The circulation flow path 420 is connected to a flow path in which a safety valve 421 provided in the turbine drive water supply system 42 is provided.

  Further, the bypass flow path is branched from a part of the flow path connecting the deaerator water storage tank 32 and the booster pump 410 and joined to the flow path connecting the warming valve 415 and the water pump for driving the motor 411. 430 is formed. A deaerator circulation pump 431 that pumps water supplied from the deaeration system 30 is provided on the upstream side of the bypass channel 430, and a bypass valve 432 is provided on the downstream side. With such a configuration, the water supply from the deaeration system 30 can be circulated through the bypass channel 430 when the turbine is not driven. In addition, the turbine here may be any of the various turbines 11 and 13 to 15 that constitute a part of the combustion system 10, or may be a turbine provided separately.

  By combining the above-described flow paths, the motor-driven water supply pump 411 is warmed in the water supply system 40 when the turbine-driven water supply pump fails or when the motor-driven water supply pump 411 is regularly checked. Therefore, a warming path can be formed. Such a warming path is formed by the circulation flow path 420 joining the turbine drive water supply system 42, and the fluid is circulated by the pump pressure from the turbine drive water supply system 42. Here, the warming path may be formed so as to merge with any one of the turbine-driven water supply systems 42 or may be formed so as to merge with the two turbine-driven water supply systems 42.

  With the configuration as described above, the control means generates a start command signal for the motor-driven water supply pump 411 when starting the motor-driven water supply pump 411 from a warming state in which the motor-driven water supply pump 411 is warmed. Based on this, the warming valve 415 provided in the middle of the circulation flow path 420 constituting the turbine drive water supply system 42 is closed. Thereby, since the flow path connected to the safety valve 421 can be shut off, backflow to the turbine drive water supply system 42 can be prevented.

  Further, the control means closes the warming valve 415 and opens the bypass valve 432 so as to open the motor-driven water supply pump via the bypass channel 430 when an abnormality occurs in the circulation channel 420. It can also be controlled to warm 411.

  As described above, according to the present embodiment, the water supply from the deaerator 31 is circulated through the motor drive water supply pump 411 before the water supply from the deaerator 31 is supplied through the motor drive water supply pump 411 during the normal operation. By closing the warming valve 415 and shutting off a part of the flow path, excessive pressure is not applied to the flow path (part of the warming path) connected to the safety valve 421, and the safety valve 421 Can be prevented from operating. Thereby, it is also possible to prevent a valve seat leak or the like caused by the operation of the safety valve 421.

It is the schematic of the electric power generation system which concerns on this embodiment. It is a block diagram which shows the principal part of the water supply system which concerns on this embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Combustion system 11 High pressure turbine 12 Boiler 13 Medium pressure turbine 14, 15 Low pressure turbine 16 Generator 20 Condensate system 21 Condenser 30 Deaeration system 31 Deaerator 32 Deaerator water storage tank 40 Water supply system 41 Motor drive water system 410 Booster Pump 411 Motor Drive Water Supply Pump 412 Fluid Coupling 413, 414 Motor 415 Warming Valve 42 Turbine Drive Water Supply System 420 Circulation Channel 421 Safety Valve 430 Bypass Channel 431 Deaerator Circulation Pump 432 Bypass Valve

Claims (5)

A combustion system comprising a turbine driven by steam supply from a boiler;
A condensate system comprising a condenser for condensing steam used in the turbine;
A degassing system comprising a degasser for degassing and supplying the condensed water condensed in the condenser;
A water supply system comprising a motor-driven water supply system including a motor-driven water supply pump provided between the deaeration system and the combustion system and driven by a motor, and a turbine-driven water supply system including a turbine-driven water supply pump driven by a turbine When,
Control means for controlling each flow path configured in the water supply system,
The control means is installed in the middle of a flow path constituted by joining the turbine-driven water supply system via the motor-driven water supply pump based on a start command when starting the motor-driven water supply pump A power generation system characterized by closing a valve that is provided. The motor-driven water supply system further includes a bypass flow path that includes a circulation pump that pumps water supplied from the deaeration system, and the water supply from the deaeration system passes through the bypass flow path when the turbine is not driven. The power generation system according to claim 1, wherein the power generation system is configured to circulate. The power generation system according to claim 1 or 2, wherein the turbine-driven water supply system includes two systems, and each system is connected to the motor-driven water supply system. The part of the flow path that constitutes the turbine-driven water supply system includes a circulation flow path that circulates in the water supply system via the motor-driven water supply pump. The power generation system according to any one of the above. Electricity is generated by a turbine driven by the supply of steam generated in the boiler, and the steam used in the turbine is condensed in a condenser to form condensate, and the condensate is deaerated in a deaerator to form feed water. In the power generation system that recirculates gas from the turbine to the boiler,
A water supply system characterized in that a part of a flow path circulating through a turbine drive water supply pump is cut off before water supply from the deaerator is supplied through a motor drive water pump. Control method.

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