JPH04115238U - boiler equipment - Google Patents

Abstract

(57) [Summary] [Purpose] To sufficiently dry high-humidity coal without affecting the temperature of the exhaust gas on the outlet side of the air preheater. [Structure] A boiler main body 1 having a burner 3 in a furnace 2 and a coal saver 5 in a rear heat transfer section 4, and pulverized coal for producing pulverized coal for fuel to be supplied to the burner 3 by pulverizing coal. A charcoal mill 14 and a primary air supply duct 1 that supplies air 10 to the pulverized coal mill 14 for transporting pulverized coal and drying the coal.
In the boiler apparatus equipped with 3, the inlet side of the economizer 5 of the rear heat transfer section 4 and the primary air supply duct 13 that supplies air 10 to the pulverized coal mill 14 are connected by an economizer bypass duct 21. .

Description

[Detailed explanation of the idea]

0001

[Industrial application field]

The present invention relates to a boiler device.

0002

[Conventional technology]

Hereinafter, a conventional boiler device will be explained using FIG. 3.

0003 In the figure, 1 is the boiler body, 2 is the furnace that constitutes the boiler body 1, and 3 is the furnace installed in the furnace 2. 4 is a rear heat transfer part connected to the outlet side of the furnace 2, 5 is a burner in the rear heat transfer part 4. This is an installed energy saver.

0004 6 is connected to the exit side of the economizer 5 of the rear heat transfer section 4 and guides the exhaust gas 7 to the chimney 8. It's a duct.

[0005] 9 supplies combustion air 10 to the burner 3 by a forced ventilation fan (not shown) An air supply duct 11 is located between the air supply duct 9 and the exhaust gas duct 6. This is an air preheater installed in the exhaust gas 7 to exchange heat between the air 10 and the exhaust gas 7.

[0006] 12 is the inlet side of the energy saver 5 of the rear heat transfer section 4 and the inlet side of the air preheater 11 of the exhaust gas duct 6. This is an energy saver bypass duct that connects the

[0007] 13 branches from the air preheater 11 inlet side of the air supply duct 9 and pulverizes the coal. A primary air supply duct connected to the inlet side of a pulverized coal mill 14 that produces pulverized coal for fuel. 20 is a pulverized coal supply pipe 15 connecting between the outlet side of the pulverized coal mill 14 and the burner 3; connects the outlet side of the air preheater 11 of the air supply duct 9 and the primary air supply duct 13. The heating primary air supply duct 16 is connected to the pulverized coal in the middle of the primary air supply duct 13. The primary air fans 17, 18, and 19 installed on the inlet side of the mill 14 are each designed to save energy. device bypass duct 12, primary air supply duct 13, and heated primary air supply duct This is a damper provided in the seat 15.

[0008] Combustion is carried out into the burner 3 via the air supply duct 9 by a forced ventilation fan (not shown). In addition to supplying the air 10 for use, a part of the air 10 flowing through the air supply duct 9 is Pulverized coal mill 14 via secondary air supply duct 13 and heated primary air supply duct 15 The pulverized coal for fuel is sent to the pulverized coal pipe 20 by finely pulverizing the coal in the pulverized coal mill 14. It is conveyed to the burner 3 via.

[0009] Then, air is supplied to the pulverized coal from the pulverized coal supply pipe 20 by the burner 3 in the furnace 2. Combustion is carried out with air 10 from duct 9.

0010 Then, the combustion gas generated by combustion is discharged from the furnace 2 that constitutes the boiler body 1. Various heat transfer tubes that flow toward the heat transfer section 4 and constitute the furnace 2 and the rear heat transfer section 4 on the way. , and heats the superheater, economizer 5, etc. (not shown) provided in the furnace 2 and the rear heat transfer section 4. to generate steam, which is then discharged into the exhaust gas duct 6 as exhaust gas 7.

[0011] The exhaust gas 7 discharged to the exhaust gas duct 6 is sent from the chimney 8 through the exhaust gas duct 6. Air 1 flows through the air supply duct 9 passing through the air preheater 11 on the way 0 and heats the combustion air 10 supplied to the burner 3. .

0012 Also, a part of the air 10 heated by the air preheater 11 is transferred to the heated primary air supply duct. The air 10 flowing through the primary air supply duct 13 through the pulverized coal mill The temperature of the air 10 supplied to the pulverized coal mill 14 is increased, and the stone is pulverized by the pulverized coal mill 14. Used for drying charcoal.

[0013] When the temperature of the exhaust gas 7 is low and it is empty, such as when the boiler body 1 is started or the load is reduced, etc. When the air 10 cannot be sufficiently heated by the air preheater 11, use the energy saving bypass duct. 12 to heat the economizer 5 to remove the high temperature combustion gas before its temperature drops. , is led directly to the inlet side of the air preheater 11 of the exhaust gas duct 6, and is introduced into the air preheater 11. The temperature of the exhaust gas 7 is increased.

[0014]

[Problem that the idea aims to solve]

However, the conventional boiler device described above has the following problems.

[0015] In other words, different types of coal (such as low-quality coal) can be used in the boiler instead of high-quality coal. It is expected that the opportunities for using water will continue to increase in the future, but in particular, When using pulverized coal, that is, high humidity coal, the pulverized coal mill 14 The temperature of the air 10 supplied to the pulverized coal mill 14 in order to sufficiently dry the separated coal. It is necessary to raise the level higher than normal.

[0016] For this reason, when using high-moisture coal, the energy saving device bypass duct 12 is actively installed. The temperature of the exhaust gas 7 supplied to the air preheater 11 is increased by using The temperature of the air 10 supplied to the pulverized coal mill 14 is raised by If you do this, the temperature of the exhaust gas 7 discharged from the chimney 8 will become too high. It is regulated due to the problem of heat exchange efficiency in the air preheater 11. Even if the temperature of the exhaust gas 7 on the inlet side of the air preheater 11 is raised, the air 10 will still be heated to the required temperature. There was a problem that it was not done.

[0017] In view of the above-mentioned circumstances, this invention does not affect the temperature of the exhaust gas on the outlet side of the air preheater. The purpose of the present invention is to provide a boiler device capable of sufficiently drying high-humidity coal. It is something.

[0018]

[Means to solve the problem]

This invention is based on a boiler that has a burner in the furnace and a energy saver in the rear heat transfer section. and pulverized powder for producing pulverized coal for the fuel used to pulverize coal and supply it to burners. Coal mill and primary air supplying air for transporting pulverized coal and drying coal to the pulverized coal mill. In boiler equipment equipped with a supply duct, the power saving device inlet side of the rear heat transfer section and the pulverized coal mixer An energy saver bypass duct connects the primary air supply duct that supplies air to the The present invention relates to a boiler device characterized by the following.

[0019]

[Effect]

According to the present invention, the high-temperature combustion gas on the inlet side of the economizer in the rear heat transfer section is The pulverized coal is mixed with air from the primary air supply duct through the Ipass duct and directly Even high-humidity coal can be sufficiently dried in the pulverized coal mill. Wear.

[0020]

【Example】

Embodiments of the present invention will be described below with reference to the drawings.

[0021] FIG. 1 shows a first embodiment of the present invention.

[0022] In addition, in the figure, the same parts as in Figure 3 are given the same reference numerals for explanation. The description will be omitted, and only the configuration unique to the present invention will be explained below.

[0023] The inlet side of the economizer 5 of the rear heat transfer section 4 that constitutes the boiler body 1 and the pulverized coal mill 14 are Between the primary air supply duct 13 that supplies air 10 for transporting powdered coal and drying coal are connected with the economizer bypass duct 21, and an exhaust gas is connected in the middle of the economizer bypass duct 21. A gas supply fan 22 is provided.

[0024] In addition, 23 is a damper provided in the middle of the economizer bypass duct 21.

[0025] Next, the operation will be explained.

[0026] The basic operation of the boiler device itself is the same as that shown in FIG. 3, so a description thereof will be omitted.

[0027] In this invention, when using high-moisture coal, a coal saver bypass duct 21 is used. The high-temperature combustion gas before its temperature is lowered by heating the energy saver 5 is supplied as primary air. Directly leads the supply duct 13 to the inlet side of the pulverized coal mill 14, and connects the primary air supply duct 13 and the processing The temperature of the air 10 introduced from the hot primary air supply duct 15 to the pulverized coal mill 14 is increased. make it grow.

[0028] As a result, the temperature of the exhaust gas 7 supplied to the air preheater 11 can be slightly reduced without changing the temperature. Since the temperature of the air 10 introduced into the pulverized coal mill 14 can be increased, air preheating is possible. It is possible to prevent the temperature of the exhaust gas 7 on the outlet side of the vessel 11 from being affected, and to prevent air preheating. Since the heat exchanger 11 is not used, there are no regulations regarding heat exchange efficiency and high humidity can be avoided. Charcoal can be sufficiently dried.

[0029] Moreover, high-humidity coal is generally relatively young coal and is susceptible to spontaneous combustion when dried. Water is mixed with air 10 and exhaust gas 7 and supplied to the pulverized coal mill 14 to produce acid. Since the elemental concentration decreases, spontaneous combustion of dried high-humidity coal can be prevented. .

[0030] FIG. 2 shows a second embodiment of the present invention, in which there is no heated primary air supply duct 15, etc. Other than the configuration, it has the same configuration as the embodiment shown in FIG. It is also possible to obtain the same functions and effects as the embodiment shown in FIG. The structure of this example is based on the existing Suitable for modifying oil-fired boilers to use high-moisture coal.

[0031] Note that the present invention is not limited to the above-mentioned embodiments, and the gist of the present invention is Of course, various changes can be made within the scope.

[0032]

[Effect of the idea]

As explained above, according to the boiler device of the present invention, the exhaust gas on the outlet side of the air preheater High-humidity coal can be sufficiently dried without affecting the temperature of the dry high-humidity coal. It can have an excellent effect of preventing spontaneous combustion.

[Brief explanation of drawings]

FIG. 1 is an overall system diagram of a first embodiment of the present invention.

FIG. 2 is an overall system diagram of a second embodiment of the present invention.

FIG. 3 is an overall system diagram of a conventional example.

[Explanation of symbols]

1 Boiler body 2 Furnace 3 burners 4 Rear heat transfer section 5. Carbon saver 10 Air 13 Primary air supply duct 14 Pulverized coal mill 21 Energy saving bypass duct

Claims (1)

[Scope of utility model registration request] Claim 1: A boiler body having a burner in the furnace and a coal saver in the rear heat transfer section; a pulverized coal mill for producing pulverized coal for fuel to be supplied to the burner by pulverizing coal; In a boiler device equipped with a primary air supply duct that supplies air for transporting pulverized coal and for drying coal to a pulverized coal mill, the primary air supply duct supplies air to the economizer inlet side of the rear heat transfer section and to the pulverized coal mill. A boiler device characterized in that a supply duct is connected to the supply duct by an energy saver bypass duct.