JPS6213901A - Method of controlling main steam pressure of high-speed fluidized bed boiler - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for controlling the pressure of main steam generated in a high-speed fluidized bed boiler consisting of a combustor and an external heat exchanger.

[Conventional technology]

The high-speed fluidized bed boiler itself is a new technology, and as shown in Figure 2, the high-speed fluidized bed boiler is a high-speed fluidized combustion furnace called CompassF2. Fuel supply device 1 that supplies granular fuel to the combustor 2. A cyclone 3 that collects the granular fuel scattered from the combustor 2 and led through the duct 6 and separates it from the gas. 7. A recycle drain pipe that discharges the powdered fuel collected by the cyclone 3 from the cyclone 3 as a recycle drain. It is installed in the middle of the recycle drain pipe 7, and a part of the recycle drain is directly connected to the combustor 2.
4. A recycle drain control valve that adjusts the flow rate of the recycle drain to direct the remainder to the external heat exchanger 5. It is comprised of a recycle pipe 8 that guides the recycle drain from the external heat exchanger 5 to the combustor 2 again.

Powdered fuel is supplied from the fuel supply device 1 into the combustor 2, and a part of the high-temperature recycle drain is directly circulated into the combustor 2 via the recycle drain control valve 4 from the recycled drain separated by the cyclone 3. The remaining recycled drain, which has been reduced in temperature by removing heat in the external heat exchanger 5, is circulated into the combustor 2 through the recycled drain pipe 8.

The powdered fuel supplied into the combustor 2 and the recycled drain are combusted by high pressure air supplied into the combustor 2 from a high pressure air supply device (not shown), while the flow rate is increased to 4.
It flows at a high speed of ~10 m/s and scatters. The scattered solid content includes unburned matter, and this unburned matter is led to the cyclone 3 together with the gas, where it is separated into gas and recycled drain. The gas passes through a flue 9 to a reheater (not shown).

It is sent to a heat exchange section where a superheater, 8 economizers, etc. are arranged. On the other hand, the recycled drain is divided into high temperature and low temperature and circulated within the combustor 2 as described above. External heat exchanger 5
In this case, feed water is delivered and absorbs heat from the hot recycle drain, and the feed water evaporates to produce main steam.

[Problem that the invention seeks to solve]

The high-speed fluidized bed boiler itself is a new technology, so the technology to control the pressure of the main steam generated in the high-speed fluidized bed boiler has not yet been established, and the technology to control the main steam pressure is needed. It is rare.

[Means for solving problems]

Therefore, in order to control the pressure of main steam generated in a high-speed fluidized bed boiler, the present invention supplies granular fuel into the combustor formed by the furnace wall.

Powdered fuel scattered from the combustor is collected and a portion is recycled as a drain via an external heat exchanger.

In a method of controlling the main steam pressure of a high-speed fluidized bed boiler that supplies the remainder directly into the combustor, the high-speed fluidization system adjusts the flow rate of recycled condensate introduced into the external heat exchanger and the amount of granular fuel input into the combustor. A method for controlling main steam pressure in a floor boiler is provided.

[Effect]

According to the method of the present invention, the amount of evaporation in the external heat exchanger can be adjusted by adjusting the flow rate of recycle drain introduced into the external heat exchanger.
Combustion temperature is controlled by controlling the steam pressure and adjusting the amount of powdered fuel input into the combustor.

〔Example〕

An embodiment of the present invention will be explained based on FIGS. 1a and 1b. Note that FIGS. 1a and 1b are block diagrams of a control device for implementing the present invention.

A pressure transmitter 11 detects the pressure of steam generated by the external heat exchanger 5. The value detected by the pressure transmitter 11 is converted into a signal and input to the pressure regulator 12. The pressure regulator 12 compares, for example, an input steam pressure signal with a set signal to obtain a deviation, and performs calculations such as integrating this deviation value to obtain an adjustment signal.

The signal obtained by the pressure regulator 12 is input to an adder 13, where a pressure control advance signal 14 is added, and an operation signal 15 for controlling the opening degree of the recycle drain control valve 4 is output from the adder 13. Ru. Based on this operation signal, the opening degree of the recycle drain control valve 4 is adjusted.

The amounts of recycled drain introduced to the external heat exchanger 5 and recycled drain directly introduced into the combustor 2 are adjusted. For example, when the amount of recycled drain introduced to the external heat exchanger 5 decreases, the amount of heat received by the feed water decreases, the amount of evaporation of the feed water decreases, and the pressure of steam decreases.

16 is a temperature transmitter that detects the temperature inside the combustor 2;
The value detected by this temperature transmitter 16 is converted into a signal,
The temperature is input to the temperature controller 17. Which temperature controller 17 is 1
For example, an input temperature signal and a setting signal are compared to find a deviation, and the deviation value is integrated or otherwise calculated to obtain an adjustment signal. The signal obtained by the temperature controller 17 is input to an adder 18, where the addition of the temperature control advance signal 19 is adjusted to adjust the amount of fuel supplied into the combustor 2. For example, when the amount of fuel input decreases, the calorific value of the fuel decreases, resulting in a decrease in the amount of fuel input. □7,7□Eng 6
．． 9. . 73(7)□. The temperature of the exhaust gas flowing into the heat transfer section 1 decreases, the degree of superheating of the steam decreases, and the pressure decreases. At the same time, the temperature of the recycle drain led to the external heat exchanger 5 also decreases, so the amount of heat received by the feed water is small. As a result, the amount of evaporation of the feed water decreases, and the steam pressure decreases.

(Effects) According to the method of the present invention, by controlling the combustion temperature by adjusting the flow rate of the recycle train introduced into the external heat exchanger and the amount of granular fuel input into the combustor, By adjusting the amount of heat that the feed water receives in the external heat exchanger, the pressure of the steam can be adjusted.

[Brief explanation of drawings]

FIGS. 1a and 1b are diagrams showing a control device for carrying out the method of the present invention, respectively, and FIG. 2 is a diagram showing a high-speed fluidized bed boiler. 11-pressure transmitter, 12-pressure regulator, 13--11-adder, 14--pressure control advance signal, 15--operation signal. 16--1 temperature transmitter, 17--1 temperature controller,
18--one adder, 19-temperature control advance signal, 2
0-----1 operation signal I Bonkurito Akira Itama, 1゜122--1 iPJf seal (a) p321

Claims (1)

[Claims] The granular fuel is supplied into the combustor formed by the furnace wall, and the granular fuel scattered from the combustor is collected and used as a recycling drain. A part of it is passed through an external heat exchanger, and the rest is directly sent to the combustor. The method for controlling the main steam pressure of a high-speed fluidized bed boiler supplied to the combustor is characterized by adjusting the flow rate of recycle drain introduced to the external heat exchanger and the amount of the granular fuel input to the combustor. Main steam pressure control method for high speed fluidized bed boiler.