A method for calculating the maximum output of feedwater pump auxiliary equipment in thermal power plants

Abstract

The present invention discloses a method for calculating the maximum output of the auxiliary equipment of a thermal power plant's feedwater pump. The method utilizes a steam-powered power plant operating mode: when the steam pump trips, the RB is triggered, and the maximum output of the auxiliary equipment of the feedwater pump is reduced to 30% and sent to the unit's RB determination circuit. The method considers each possible operating condition of the feedwater pump during operation, accurately calculating the maximum output of the auxiliary equipment of the feedwater pump and correctly determining the unit's RB by using the feedwater pump's output on / off button. The method encompasses all different operating modes of the feedwater pump, ensuring the accuracy and reliability of the maximum output calculation circuit for the feedwater pump under each operating mode, while also avoiding malfunction or failure of the feedwater pump's RB under extreme operating conditions.

Description

Technical Field

[0001] The present invention relates to the technical field of transformer substation automatic control equipment, in particular to a method for calculating the maximum output of auxiliary equipment for a feedwater pump in a thermal power plant. Background Art

[0002] Substation automatic control consists of three parts: dispatching-end automatic control device, substation automatic control device, and the channel that provides connection between the devices at both ends. Automatic control is implemented by the on-duty dispatcher operating on the dispatching-end computer to control the corresponding substation equipment and realize remote control actions. Therefore, substation automatic control is also called telecontrol, the devices at both ends are also called telecontrol devices, and the substation automatic control channel is also called telecontrol channel. There are three types of channels for substation automatic control: analog channel, digital channel and network channel.

[0003] The water supply system is one of the main systems in a thermal power plant. The main equipment involved is steam-driven feed water pumps, electric feed water pumps and other main equipment. Generally, there are three of them. The existing feed water pump RB has the following defects: 1. When two steam-driven feed water pumps are running in parallel and the electric feed water pump is running along with them, it is impossible to correctly judge the maximum output of the feed water pump, which affects the normal realization of the unit RB; 2. When a steam-driven feed water pump and an electric feed water pump are running in parallel, the maximum output of the feed water pump cannot be correctly judged during the run-up of the other steam-driven feed water pump, which affects the normal realization of the unit RB; 3. When a steam-driven feed water pump and an electric feed water pump are running in parallel, if the original steam-driven feed water pump trips during the run-up of the other steam-driven feed water pump, the maximum output of the feed water pump cannot be correctly judged, which affects the normal realization of the unit RB. Summary of the Invention

[0004] The purpose of the present invention is to provide a method for calculating the maximum output of auxiliary equipment of a feedwater pump in a thermal power plant, so as to solve the problem in the background art that the operation of the steam-driven feedwater pump affects the normal realization of the unit RB.

[0005] To achieve the above object, the present invention provides the following technical solution: a method for calculating the maximum output of a feedwater pump auxiliary machine in a thermal power plant, comprising the following steps:

[0006] S1: Two steam and one electric operation mode: If any steam pump trips, the maximum output of the feedwater pump auxiliary equipment will drop to 80% and be sent to the unit's RB judgment circuit.

[0007] S2: Two steam pumps operation mode: If any one of the steam pumps trips and the electric pump is started, the maximum output of the feedwater pump auxiliary equipment drops to 70% and is sent to the unit RB judgment circuit.

[0008] S3: FAW-Electric operation mode: The steam pump trips and triggers RB, and the maximum output of the water supply pump auxiliary equipment drops to 30% and is sent to the unit's RB judgment circuit.

[0009] Preferably, when RB is reset in the two-steam-one-electric operation mode, the maximum output of the water pump auxiliary machine is 95%.

[0010] Preferably, when the RB of the two steam pumps operating modes is reset, the maximum output of the water supply pump auxiliary machine is 95%.

[0011] Preferably, when RB is reset in the FAW-Electric operation mode, the maximum output of the water pump auxiliary machine is 30%.

[0012] Preferably, the cut-off conditions (manual reset) are allowed: (maximum load capacity of the water supply pump - load capacity of the pump to be cut off) > current furnace master control.

[0013] Preferably, the automatic cut-off condition (automatic reset) is: when the pump stops operating, its allowable load capacity is automatically cut off.

[0014] Preferably, the enabling condition (manual setting) is: the pump is running.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows: the calculation method of the maximum output of the auxiliary equipment of the feed water pump of the thermal power plant takes into account one by one the operating conditions of the feed water pump that may occur during operation, and realizes the correct calculation of the maximum output of the auxiliary equipment of the feed water pump through the output switching button of the feed water pump, and completes the correct judgment of the unit RB; it covers all different operating modes of the feed water pump, and under each operating mode, it can ensure the accuracy and reliability of the maximum output calculation circuit of the feed water pump, while avoiding the malfunction and refusal of the feed water pump RB under extreme special conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 A schematic diagram of a calculation module for the maximum output of a feedwater pump auxiliary machine of a thermal power plant according to a method for calculating the maximum output of a feedwater pump auxiliary machine of the present invention;

[0017] Figure 2 A logical diagram of the allowable load capacity of each pump in a method for calculating the maximum output of auxiliary equipment for feedwater pumps in a thermal power plant according to the present invention;

[0018] Figure 3 A logical diagram of the allowable load capacity of each pump in a method for calculating the maximum output of auxiliary equipment for feedwater pumps in a thermal power plant according to the present invention;

[0019] Figure 4 The present invention provides a logic diagram of the allowable load capacity of each pump in a method for calculating the maximum output of auxiliary equipment of a feedwater pump in a thermal power plant. DETAILED DESCRIPTION

[0020] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0021] See also Figure 1-4 The present invention provides a technical solution: a method for calculating the maximum output of a feedwater pump auxiliary machine in a thermal power plant, comprising the following steps:

[0022] S1: Two-steam and one-electric operation mode: if any one of the steam pumps trips, the maximum output of the feedwater pump auxiliary machine will drop to 80% and be fed into the RB judgment circuit of the unit; when the RB is reset in the two-steam and one-electric operation mode, the maximum output of the feedwater pump auxiliary machine will be 95%; S2: Two-steam pump operation mode: if any one of the steam pumps trips and the electric pump is started in conjunction, the maximum output of the feedwater pump auxiliary machine will drop to 70% and be fed into the RB judgment circuit of the unit; when the RB is reset in the two-steam pump operation mode, the maximum output of the feedwater pump auxiliary machine will be 95%; S3: One-steam and one-electric operation mode: if the steam pump trips and triggers the RB, the maximum output of the feedwater pump auxiliary machine will drop to 30% and be fed into the RB judgment circuit of the unit; when the RB is reset in the FAW and one-electric operation mode, the maximum output of the feedwater pump auxiliary machine will be 30%; (the above refers to the appendix of the instruction manual Figure 1 ); Allowable cut-off condition (manual reset): (maximum load capacity of water pump - load capacity of pump to be cut off) > current furnace master control; Automatic cut-off condition (automatic reset): when the pump stops, its allowable load capacity is automatically cut off; Allowable input condition (manual setting): the pump is running; (the above refers to the attached manual Figures 2 to 3 ); The calculation method of the maximum output of the auxiliary equipment of the feedwater pump of the thermal power plant takes into account the possible operating conditions of the feedwater pump during operation, and realizes the correct calculation of the maximum output of the auxiliary equipment of the feedwater pump through the output switching button of the feedwater pump, and completes the correct judgment of the unit RB; it covers all different operating modes of the feedwater pump, and can ensure the accuracy and reliability of the maximum output calculation circuit of the feedwater pump under each operating mode, while avoiding the malfunction and refusal of the feedwater pump RB under extreme special conditions.

[0023] Working principle: The working principle of the calculation method of the maximum output of the auxiliary equipment of the water supply pump of the thermal power plant is as follows, as shown in the attached manual. Figure 1As shown, the calculation module for the maximum output of the feedwater pump auxiliary machine is as follows: Two-steam and one-electric operation mode: if any one steam pump trips, the maximum output of the feedwater pump auxiliary machine drops to 80% and is sent to the unit RB judgment circuit. When RB is reset, the maximum output of the feedwater pump auxiliary machine is 95%; Two-steam pump operation mode: if any one steam pump trips and the electric pump is started in conjunction, the maximum output of the feedwater pump auxiliary machine drops to 70% and is sent to the unit RB judgment circuit. When RB is reset, the maximum output of the feedwater pump auxiliary machine is 95%; One-steam and one-electric operation mode: if the steam pump trips and triggers RB, the maximum output of the feedwater pump auxiliary machine drops to 30% and is sent to the unit RB judgment circuit. When RB is reset, the maximum output of the feedwater pump auxiliary machine is 30%; as shown in the attached manual Figure 2-3 As shown, the on-off buttons of the allowable load capacity of each pump are set, and the logic is as follows: Allowable cut-off condition (manual reset): (maximum load capacity of the feed water pump - load capacity of the pump to be cut off) > current boiler master control; Automatic cut-off condition (automatic reset): when the pump stops operating, its allowable load capacity is automatically cut off; Allowable input condition (manual setting), the pump is running. This is the working principle of the calculation method of the maximum output of the feed water pump auxiliary equipment of the thermal power plant.

[0024] Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments, or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for calculating the maximum output of a feedwater pump auxiliary unit in a thermal power plant, comprising the following steps: S1: Two steam and one electric operation mode: If any steam pump trips, the maximum output of the feedwater pump auxiliary equipment will drop to 80% and be fed into the unit's RB judgment circuit; S2: Two steam pump operation mode: If any one of the steam pumps trips and the electric pump is started, the maximum output of the feedwater pump auxiliary equipment drops to 70% and is sent to the unit's RB judgment circuit; S3: FAW-Electric operation mode: The steam pump trips and triggers RB, the maximum output of the feedwater pump auxiliary equipment drops to 30% and is sent to the unit's RB judgment circuit; When the RB is reset in the two-vehicle-one-electric operation mode, the maximum output of the feedwater pump auxiliary machine is 95%; When the RB of the two steam pumps is reset in the operation mode, the maximum output of the feedwater pump auxiliary machine is 95%; When RB is reset in the FAW-Electric operation mode, the maximum output of the water pump auxiliary machine is 30%.

2. The method for calculating the maximum output of a feedwater pump auxiliary machine in a thermal power plant according to claim 1, characterized in that: Allowable cut-off conditions, manual reset: (maximum load capacity of the water supply pump - load capacity of the pump to be cut off) > current furnace master control.

3. The method for calculating the maximum output of a feedwater pump auxiliary machine in a thermal power plant according to claim 1, characterized in that: Automatic cut-off condition and automatic reset: When the pump stops operating, its allowable load capacity will be automatically cut off.

4. The method for calculating the maximum output of auxiliary equipment of a feedwater pump in a thermal power plant according to claim 1, characterized in that: Allowable start-up conditions, manual setting: the pump runs.

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