Boiler system composition, boiler body construction, and three water cycle principles 10

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The boiler water circulation system consists of a steam drum, a descending tube, a lower casing box, a rising pipe (i.e., a water-cooled wall pipe group) and an upper casing.

Because the riser tube absorbs heat inside the furnace, part of the water becomes Livolt steam, and the density of the soda-water mixture is small, while the descending tube is not heated outside the furnace, and the tube is imitation water, and the working fluid density is large.

The difference in density between the two forms a driving force, so that the steam-water mixture flows upwards along the riser pipe and enters the steam drum through the upper box for interference, and the water in the steam drum flows into the lower box through the descending pipe and enters the water cooling wall, thus forming a natural circulation flow of water.

It's a big topic. To put it simply, a boiler is a heating and pressurizing device that heats water to the required temperature and pressure and delivers it to the user. But the real modern boiler equipment is the crystallization of extremely complex and high-tech, Kai may be said to use the latest scientific and technological achievements, representing the current leading level of automation and manufacturing.

The heating and pressurization process of the hydraulic fluid can be completed with a variety of fuels or energies, and the system is extremely complex.

Brand model: Midea wall-hung boiler.

System: 26R06

The overall structure of the boiler includes two parts: the boiler body and auxiliary equipment. The boiler body is composed of a steam-water system (pot) and a combustion system (furnace), and the steam-water system is composed of a steam economizer, a steam drum, a descending pipe, a joint box, a water wall, a superheater, a reheater, etc., and its main task is to effectively absorb the heat released by fuel combustion, and heat the feed water entering the boiler to form superheated steam with a certain temperature and pressure. The combustion system of the boiler is composed of a furnace, a flue, a burner, an air preheater, etc., and its main task is to make the fuel burn well in the furnace and release heat.

In addition, the boiler body also includes a furnace wall and a frame, the furnace wall is used to form a closed furnace chamber and flue, and the frame is used to support and suspend the steam drum, heating surface, furnace wall, etc. There are many auxiliary equipment, mainly including ventilation equipment, fuel transportation equipment, milling equipment, water supply equipment, dust and ash removal equipment, flue gas desulfurization and denitrification equipment, water treatment equipment, measurement and control equipment, etc.

The working principle of the boiler: the boiler is carried out in the two parts of "pot" and "furnace" at the same time, after the water enters the boiler, the heat absorbed by the heating surface of the boiler in the steam-water system is transferred to the water, so that the water is heated into hot water at a certain temperature and pressure or generates steam, which is led out of the application. In the combustion equipment part, the fuel combustion continuously releases heat, and the high-temperature flue gas generated by combustion transfers the heat to the heating surface of the boiler through the propagation of heat, and the temperature itself gradually decreases, and finally discharged by the chimney.

The <>-friendly natural circulation boiler is a kind of boiler that uses the principle of natural convection to achieve water circulation, <> its working principle is as follows: <>

1.Water enters the boiler from the tank, <>

When heated, it turns into steam and <>

Steam rises to the steam chamber at the top of the boiler 2Water droplets in the steam chamber fall to the tank below due to gravity and <>

Form Cycle 3After a certain time cycle, <>

The temperature of the water inside the boiler gradually increases and <>

A kind of temperature gradient is formed4Under the action of the temperature gradient, the <> hot water rises to the top of the boiler and the cold water descends to the bottom of the boiler, <> forming natural convection5In the process of natural convection, the water of the Jianzhou <> is continuously circulated in the boiler and <>

So as to realize the natural circulation of water supply to the boiler, in short, <>

By using the principle of natural convection, the natural circulation boiler realizes water circulation and water supply, <> does not require external water supply devices and electric equipment, and <>

It has the advantages of simple structure, easy maintenance, safety and reliability<> but its water supply is low and <>

It is suitable for small household boilers and other occasions.

The formation of boiler water circulation is closely related to its working principle, in line with the principle of scientific and safe use, as follows:

The process of continuous flow of water and steam-water mixture in the circulation loop of the hot water boiler evaporation equipment is called the water circulation of the hot water boiler.

In order for it to operate safely and reliably, the evaporation plant must have a proper water cycle.

The temperature around the evaporative heating surface is very high, and if the wall temperature exceeds the limit operating temperature of the pipe material, the pipe is prone to damage.

The temperature of the pipe wall mainly depends on the flow of the soda mixture in the pipe.

The flow of the soda mixture in the vertical round tube is mainly bubble-shaped, vapor-elastic, vapor-column-like and mist-like.

It can be seen from the flow condition that in order to make the heating surface work safely and reliably, the continuous flow of water should be ensured, that is, to ensure that there is a good water circulation, so that there is a continuous water film on the inner wall of the pipe, and the soda mixture has a certain flow rate in the upward flow process to prevent the formation of mist flow.

Second, the basic concept of natural circulation of hot water boilers:

A complete circulation circuit is formed by the lower pipe arranged outside the furnace wall and the rising pipe (i.e. water cooling wall) inside the furnace, as well as the upper pot barrel and header connected to it.

Because the rising tube absorbs and absorbs radiant heat in the furnace, part of the water becomes water vapor, the density of the steam-water mixture is small, and the descending tube is not heated outside the furnace, the tube is water, the density is large, and the difference in density between the two produces a driving force, so that the steam-water mixture flows upward along the rising pipe into the steam drum, and the water in the steam drum flows into the lower box through the descending pipe, so as to form a natural circulation flow of water.

3. Hot water boiler water circulation failure:

Circulation stagnation, circulation backflow, steam stratification, (horizontal or inclined pipes), descent pipes with steam.

4. Factors that disrupt the water cycle:

Improper sewage discharge, low drum water level, large load change, and fouling in the pipe.