阅读说明：本技术 一种一次风压控制系统及其控制方法 (Primary air pressure control system and control method thereof ) 是由 郭荣 赵春荣 陈国巍 陶丽 康磊 于 2019-09-18 设计创作，主要内容包括：本发明涉及一种一次风压控制系统及其控制方法,属于火力发电技术领域。包括集散控制系统(DCS)、给煤控制模块、热风挡板控制模块和一次风压控制模块。通过采用磨煤机最大给煤量值计算一次风压设定值,实现了一次风压在启停磨煤及断煤情况下的控制稳定,极大地提高了机组的运行安全稳定性。同时通过磨煤机入口热风挡板的开度指令修正一次风压,在开度较小时通过修正将一次风压降低并开大磨煤机入口热风挡板,通过节流实现降低一次风机的用电,实现一次风机的经济运行。本发明提供的一次风压控制方法,实现了在保证送粉可靠,机组安全稳定运行的基础上,兼顾一次风压的运行经济性。(The invention relates to a primary air pressure control system and a control method thereof, and belongs to the technical field of thermal power generation. The system comprises a Distributed Control System (DCS), a coal feeding control module, a hot air baffle control module and a primary air pressure control module. The set value of the primary air pressure is calculated by adopting the maximum coal feeding quantity value of the coal mill, so that the control stability of the primary air pressure under the conditions of starting, stopping and coal grinding is realized, and the operation safety and stability of the unit are greatly improved. Meanwhile, primary air pressure is corrected through an opening instruction of the hot air baffle at the inlet of the coal mill, the primary air pressure is reduced and the hot air baffle at the inlet of the coal mill is enlarged through correction when the opening is smaller, electricity consumption of the primary air fan is reduced through throttling, and economic operation of the primary air fan is achieved. The primary air pressure control method provided by the invention realizes the operation economy of primary air pressure on the basis of ensuring reliable powder feeding and safe and stable operation of the unit.)

1. A primary wind pressure control system is characterized in that: comprises a Distributed Control System (DCS) (1), a coal feeding control module (2), a hot air baffle control module (3) and a primary air pressure control module (4); the coal feeding control module (2) transmits a coal feeding instruction to a Distributed Control System (DCS) (1); a Distributed Control System (DCS) (1) performs data processing on a plurality of coal feeding command values transmitted by the coal feeding control module (2), and calculates a primary air pressure setting initial value according to the coal feeding command values; the hot air baffle control module (3) transmits the opening data of the hot air baffle to a Distributed Control System (DCS) (1), and the Distributed Control System (DCS) (1) performs data processing on the opening data of the hot air baffle transmitted by the hot air baffle control module (3), corrects and calculates a primary air pressure set initial value according to a coal feeding instruction value, and gives a final primary air pressure set value; the Distributed Control System (DCS) (1) transmits the final primary wind pressure set value to the primary wind pressure control module (4); and the primary wind pressure control module (4) controls primary wind pressure according to the final primary wind pressure set value.

2. A primary air pressure control method is characterized by comprising the following steps:

step 1: the coal feeding control module (2) transmits coal feeding instructions executed by a plurality of coal mills to a Distributed Control System (DCS) (1).

Step 2: the Distributed Control System (DCS) (1) performs data processing on a plurality of coal feeding command values transmitted by the coal feeding control module (2), obtains the maximum coal feeding command value, and calculates a primary air pressure setting initial value according to the maximum coal feeding command value.

And step 3: the hot air baffle control module (3) transmits the opening data of the hot air baffle to a Distributed Control System (DCS) (1).

And 4, step 4: and the Distributed Control System (DCS) (1) performs data processing on the opening data of the hot air baffle plate transmitted by the hot air baffle plate control module (3), and when all the opening data of the hot air baffle plate are smaller than a standard value of 80%, corrects and calculates a primary air pressure set initial value according to the coal supply instruction value, and gives a final primary air pressure set value.

And 5: and the Distributed Control System (DCS) (1) transmits the final primary wind pressure set value to the primary wind pressure control module (4).

Step 6: and the primary wind pressure control module (4) controls primary wind pressure according to the final primary wind pressure set value.

Technical Field

The invention relates to a primary air pressure control system and a control method thereof, and belongs to the technical field of thermal power generation.

Background

The primary air is air which is sent into a hearth from a pulverized coal pipeline along with pulverized coal when the pulverized coal furnace burns, and is mainly used for carrying the pulverized coal. Besides, the primary air plays a leading role in the combustion of the pulverized coal of the boiler. The primary air carries the pulverized coal into the hearth, the quantity of the air which is required by the pulverized coal combustion to complete the preheating and combustion two stages is the most main part of the total required actual air quantity during the quantitative fuel combustion. When the load of the pulverized coal is changed, the coal feeding amount is changed, and the corresponding primary air pressure is also changed. Conventional control schemes are generally: the set value of the primary air pressure follows the average coal feeding amount of the coal mill, and at the moment, although the synchronous change of the primary air and the fuel can be ensured and the responsiveness of pulverized coal airflow combustion can be enhanced, the primary air pressure can be greatly changed when the coal mill is started or stopped, so that the combustion stability is not facilitated; even because the coal feeding amount of each coal mill is set to be inconsistent in actual operation, the problem of blockage of the coal mill with larger coal feeding amount is caused, and the safe and stable operation of the unit is greatly influenced. Therefore, the technical field needs to optimally control the parameters of primary air pressure which affect the safe operation and the combustion responsiveness of the unit, and the quick responsiveness and the economical efficiency are realized while the safe and stable operation of the unit is ensured.

Disclosure of Invention

The invention aims to solve the technical problem of optimizing and controlling parameters which affect the safe operation and the combustion responsiveness of a unit, namely primary air pressure.

In order to solve the above problems, the technical solution of the present invention is to provide a primary air pressure control system, which is characterized in that: the system comprises a Distributed Control System (DCS), a coal feeding control module, a hot air baffle control module and a primary air pressure control module; the coal feeding control module transmits a coal feeding instruction to a Distributed Control System (DCS); a Distributed Control System (DCS) performs data processing on a plurality of coal feeding command values transmitted by the coal feeding control module, and calculates a primary air pressure setting initial value according to the coal feeding command values; the hot air baffle control module transmits the opening data of the hot air baffle to a Distributed Control System (DCS), the DCS performs data processing on the opening data of the hot air baffle transmitted by the hot air baffle control module, and corrects a primary air pressure set initial value calculated according to a coal feeding instruction value to give a final primary air pressure set value; the Distributed Control System (DCS) transmits the final primary wind pressure set value to the primary wind pressure control module; and the primary air pressure control module controls primary air pressure according to the final primary air pressure set value.

The invention also provides a primary wind pressure control method, which is characterized by comprising the following steps:

step 1: the coal feeding control module transmits coal feeding instructions executed by the coal mills to a Distributed Control System (DCS).

And 2, performing data processing on a plurality of coal feeding command values transmitted by the coal feeding control module by a Distributed Control System (DCS), taking the maximum coal feeding command value, and calculating a primary air pressure setting initial value according to the maximum coal feeding command value.

And 3, transmitting the opening data of the hot air baffle to a Distributed Control System (DCS) by the hot air baffle control module.

And 4, performing data processing on the opening data of the hot air baffle transmitted by the hot air baffle control module by a Distributed Control System (DCS), and correcting to calculate a primary air pressure set initial value according to the coal feeding instruction value and give a final primary air pressure set value when all the opening data of the hot air baffle are smaller than a standard value of 80%.

And 5, transmitting the final primary wind pressure set value to a primary wind pressure control module by a Distributed Control System (DCS).

And 6, adjusting the opening of the primary fan blade by the primary wind pressure control module according to the final primary wind pressure set value and by combining the characteristic function, and finally realizing the correction and the optimized control of the primary wind pressure.

The invention aims to provide a primary wind pressure control system and a control method thereof, which comprehensively consider the safety, the responsiveness and the economy, thereby realizing the purposes of improving the safe and stable operation of a unit, meeting the automatic power generation control and assessment requirements of a power grid and saving electricity. The primary air pressure is set to follow the maximum coal feeder instruction, and meanwhile, the opening degree of a hot air baffle of the coal mill is adopted for correction. The coal feeder is used for realizing that under the working conditions of coal breaking, coal grinding starting and stopping and the like, the primary air pressure setting cannot be greatly disturbed, and the primary air pressure fluctuation is reduced, so that the safe and stable operation is facilitated.

On the other hand, in order to reduce the primary fan current, the primary air pressure setting is corrected by the opening of the hot air baffle at the inlet of the coal mill, and when the opening of the hot air baffle is less than 80%, the throttling action of the primary air is reduced by reducing the primary air pressure (for example, when the opening is 50%, the correction amount is at most-0.4 KPa) and increasing the opening of the baffle. At this time, a Distributed Control System (DCS) performs data processing on the hot air baffle opening data transmitted from the hot air baffle control module, corrects a primary air pressure setting initial value calculated from the coal supply instruction value, and gives a final primary air pressure setting value. And the Distributed Control System (DCS) transmits the final primary wind pressure set value to the primary wind pressure control module, so that primary wind pressure is reduced. Meanwhile, the operator can gradually increase the opening of the baffle by operating the hot air baffle actuator mechanism, and the throttling function of primary air is reduced on the premise of ensuring the air pressure, so that the power consumption of the primary air fan is reduced.

According to the invention, the primary air pressure control system is optimized, so that the running economy of primary air pressure is improved while the powder feeding reliability and the safe and stable running of the unit are ensured. Through the throttle effect that reduces coal pulverizer entry baffle, realize reducing primary air pressure, and then reduce primary air fan electric current, reduce the primary air fan power consumption.

Compared with the prior art, the invention has the following beneficial effects:

1. the invention carries out primary air pressure control optimization, introduces the coal feeding amount of the coal mill, obtains the maximum coal feeding amount value in the actual operation, realizes the control stability of the primary air pressure under the conditions of starting and stopping the mill and breaking the coal, and greatly improves the operation safety and stability of the unit.

2. According to the invention, through the opening instruction of the hot air baffle at the inlet of the coal mill, the primary air is throttled when the opening is smaller, the primary air pressure is reduced through correction, and meanwhile, the hot air baffle at the inlet of the coal mill is opened to be larger, so that the primary air pressure is reduced while the throttling is reduced, the power consumption of the primary air fan is reduced, and the economic operation of the primary air fan is realized.

Drawings

Fig. 1 is a schematic diagram of a primary wind pressure control system according to the present invention.

Detailed Description

In order to make the invention more comprehensible, preferred embodiments are described in detail below with reference to the accompanying drawings:

as shown in fig. 1, a primary wind pressure control system includes a Distributed Control System (DCS)1, a coal feeding control module 2, a hot wind baffle control module 3, and a primary wind pressure control module 4; the coal feeding control module 2 transmits a coal feeding instruction to a Distributed Control System (DCS) 1; a Distributed Control System (DCS)1 performs data processing on a plurality of coal feeding command values transmitted by the coal feeding control module 2, and calculates a primary air pressure setting initial value according to the coal feeding command values; the hot air baffle control module 3 transmits the opening data of the hot air baffle to a Distributed Control System (DCS)1, the Distributed Control System (DCS)1 performs data processing on the opening data of the hot air baffle transmitted by the hot air baffle control module 3, and corrects a primary air pressure set initial value calculated according to a coal feeding instruction value to give a final primary air pressure set value; the Distributed Control System (DCS)1 transmits the final primary wind pressure set value to the wind pressure control module 4; the wind pressure control module 4 controls the primary wind pressure according to the final primary wind pressure set value.

A primary air pressure control method comprises the following steps:

step 1: the coal feeding control module 2 transmits coal feeding instructions executed by a plurality of coal mills to a Distributed Control System (DCS) 1.

And 2, performing data processing on a plurality of coal feeding command values transmitted by the coal feeding control module 2 by a Distributed Control System (DCS)1, taking the maximum coal feeding command value, and calculating a primary air pressure setting initial value according to the maximum coal feeding command value.

And 3, transmitting the opening data of the hot air baffle to a Distributed Control System (DCS)1 by the hot air baffle control module 3.

And 4, performing data processing on the opening data of the hot air baffle transmitted by the hot air baffle control module 3 by a Distributed Control System (DCS)1, and correcting to calculate a primary air pressure set initial value according to the coal supply instruction value and give a final primary air pressure set value when all the opening data of the hot air baffle are smaller than a standard value of 80%.

And 5, transmitting the final primary wind pressure set value to a primary wind pressure control module 4 by the Distributed Control System (DCS) 1.

And 6, controlling primary wind pressure by the primary wind pressure control module 4 according to the final primary wind pressure set value.

While the invention has been described with respect to a preferred embodiment, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention. Those skilled in the art can make various changes, modifications and equivalent arrangements, which are equivalent to the embodiments of the present invention, without departing from the spirit and scope of the present invention, and which may be made by utilizing the techniques disclosed above; meanwhile, any changes, modifications and variations of the above-described embodiments, which are equivalent to those of the technical spirit of the present invention, are within the scope of the technical solution of the present invention.