WO2010009612A1

WO2010009612A1 - Non-gun slurry-throwing heat-accumulation moving bed boiler

Info

Publication number: WO2010009612A1
Application number: PCT/CN2009/000809
Authority: WO
Inventors: 梁兆志
Original assignee: Liang Zhaozhi
Priority date: 2008-07-21
Filing date: 2009-07-20
Publication date: 2010-01-28
Also published as: CN101344246A; CN101633854A

Abstract

A thermal storage moving bed boiler of non-gun slurry-casting is disclosed. It consists of a refractory ball moving bed (33), heat accumulators (34, 35), a Roots blower (36), a rising ball machine (31), and a falling ball machine (11), etc. The refractory ball is a slurry carrier and the movement of the ball is realized by the falling ball machine (11) and the rising ball machine (31), the ball rolls along a slurry ink-stone (2) at the bed top and stuck with pulpous state fuel, and ball-shaped fuel completes the circulation of heating up, firing and combusting, cooling down, buffing dust, and rising up to the slurry ink-stone at the top of the bed under the effect of the falling ball machine and the rising ball machine; the heat accumulators (34, 35) consist of a porcelaneous thermal storage unit (29), the heat accumulators have the effects of heat storage and release. Heat storage absorbs afterheat of flue gases, which is released from a combustion chamber (23) and unabsorbed by water. Under the control of a program controlling unit, the flow direction of flue gases and air is periodically changed by a four-way directional control valve (38) so as to lead two heat accumulators to store and release heat alternately, heat release of the heat accumulators is preheated air, and the ball fuel is combusted evenly by hot air.

Description

Heat storage moving bed boiler without gun

Technical field

The invention relates to a boiler, in particular to a regenerative moving bed boiler without gun slurry. A gunless regenerative moving bed boiler is a combustible high and low sulfur content slurry fuel (usually coal water slurry, water coke or emulsified coke or oil coal slurry or sludge or biomass fuel) The boiler has a suitable desulfurization and dust removal method.

Background technique

The background of the invention is a coal water slurry boiler atomized by a spray gun. For more than two decades, prior to the present invention, a coal water slurry boiler was atomized by a spray gun, and the coal water slurry was sprayed into a stable combustion chamber for combustion. The current spray gun atomized coal-water slurry boiler and its environmental protection facilities have the following stubborn problems: 1. The technical personnel of the coal-water slurry boiler industry know that the current coal-water slurry boilers use a spray gun and a stable combustion chamber. There are a series of problems such as difficulty in slag removal, difficulty in removing ash, difficulty in desulfurization, low burnout rate, and easy coking. These problems eventually lead to high boiler shutdown rate and low boiler efficiency, which seriously affect economic benefits. For the dust-collecting effect of the bed, a separate dust collector is required.

Summary of the invention

The object of the present invention is to provide a common problem of overcoming the common problem of the coal water slurry boiler and its environmental protection facilities for overcoming the atomization of the current spray gun, and to efficiently and environmentally create a water coal slurry instead of oil and natural gas in the boiler. cause.

The invention relates to a boiler for burning a slurry fuel such as coal water slurry, and the combustion mode of the boiler is called a heat storage moving bed.

(the Storageable Move Bed --- SMB) The combustion mode, this type of boiler is called a heat storage moving bed (SMB) boiler; because this kind of boiler can burn coal water slurry without a spray gun, also called a gunless coal water slurry boiler. This is the most distinctive feature of the present invention which distinguishes it from the conventional coal water slurry boiler atomized by a spray gun.

The problems to be solved and the achievable effects of a gunless regenerative moving bed boiler (hereinafter referred to as SMB boiler) are shown in Tables 1 and 2:

Table 1: List of issues to be addressed by SMB boilers

The problem of coal water slurry boilers atomized by spray guns in the past SMB boilers solve these problems

1. In operation, slag discharge is difficult, ash removal is difficult, and desulfurization is required. 1. No slagging during operation, no ash accumulation, and preferential desulfurization. A series of problems such as difficulty, low burnout rate, easy coking, etc., high burnout rate and no coking. Moreover, the investment is small, and the operation can eventually lead to high boiler shutdown rate, and the boiler depends on the operating cost.

Low efficiency and serious impact on economic efficiency. 2. The regenerator bed and the desulfurization tower have a double dust removal function, and there is no need to use the dust collection function of the regenerator bed, and a separate dust collector is required. There is also a dust collector.

Table 2: Comparison of the operating effects of SMB boilers and spray gun atomizing boilers:

Detailed description of the invention:

The invention adopts the regenerative moving bed of the invention (invention patent application number: 200610123561. 6, application date: November 9, 2006) as the basic combustion mode, and has been improved and improved continuously to make the regenerative moving bed combustion device It can burn coal water slurry on the boiler. This kind of boiler is shot-free and is used to solve the problem of the former coal-water slurry boiler atomized by the spray gun.

The SMB boiler is composed of a refractory ball moving bed (33), a regenerator L (34), a heat accumulator (35), a Roots blower (36), a ball raising machine (31), and the like. As shown in Fig. 1, in the physical boiler, the refractory ball moving bed (33) and the left and right regenerator beds (34, 35) are a whole that are close together, and are outsourced to the furnace wall, and the shape is substantially like a rising rectangular parallelepiped. The furnace wall is composed of three layers of lightweight heat-insulating refractory brick wall (40), insulation layer (41) and steel plate skin (42). In Fig. 1, in order to make it easy to see, the regenerative bed (34, 35) and the refractory ball moving bed (33) are drawn into three parts of the body.

The structure and operation of this boiler are explained in detail below:

A How to burn the slurry fuel without guns into the furnace:

See Figure 2: Refractory Ball Moving Bed and Figure 4: Lifting Machine Arrangement and Location of the Ash Discharge Port.

The present invention uses a refractory ball to paste into the combustion chamber (23), so that no spray gun is used. The refractory ball is a spherical refractory material made of a high temperature resistant material, having a melting point of 2000 K or more and a strong thermal shock resistance.

The refractory ball (1) is lifted by the ball lifting machine (31) to the moving bed preheating refractory ball inlet (4), rolled over a low squeegee called pulp (2), and the slurry fuel adheres to the outside of the refractory ball. On the surface, the refractory ball with the slurry fuel is called spherical fuel. The spherical fuel is then rolled to the upper part of the moving bed. This section is called the moving bed preheating section (22) to preheat the heated spherical fuel. The preheating section (22), the combustion chamber (23), and the cooling section (24) are formed in three stages. The moving bed is filled with a refractory ball, and the refractory balls are recycled, and they are sequentially and slowly moved from top to bottom. Through the preheating section (22), the combustion chamber (23), and the cooling section (24), the spherical fuel is heated, ignited, and cooled.

In the past, the coal water slurry boiler atomized by the spray gun has difficulty in slag discharge, low burnout rate, easy coking, and slagging. The following three reasons can be solved:

1. The peak combustion temperature in the moving bed of the SMB can and must be controlled below the ash melting point of the fuel, as the air and coal water slurry can be adjusted by adjusting the speed ratio of the Roots blower (36) and the ball thrower (11). The ratio of the combustion peak in the moving bed fire chamber is adjusted so that it is always below the ash melting point to prevent the ash from melting and sticking to the refractory ball.

2. The melting point of the refractory ball is very high. Above 2000K, it is not easy to be melted and stick to ash.

3. The SMB boiler can give the slurry fuel a long enough residence time to make it have a high burnout rate and very little residual carbon. The burnt ash is loose, so that after the spherical fuel is burned, one is left. The layer of loose ash shell is worn away during the transport to the pulp by the ball lifter.

The speed of the goal is controlled by the speed of the ball drop machine (11); the refractory ball that drops the screen ball (12) from the ball drop machine (11), rolls to the ramp (17), and then the ball (31) along the ball The riser tube (32) is raised to the refractory ball inlet (4) of the moving bed preheating section to complete a cycle. Thus, the refractory ball can continuously feed the slurry fuel into the combustion chamber (23), the coal water slurry enters through the feed pipe (3), and the excess slurry overflows from the slurry return pipe (26) to the slurry tank, water The joining speed of the coal paddle is basically proportional to the scoring speed. It can be adjusted by the rotation speed of the ball drop machine (11). The moving speed of the moving bed determines the power of the furnace, and the load adjustment range is wide.

In the same boiler, the ball drop mechanism consisting of the ball drop machine (11) and the ball raising machine (31) may have one or more sets depending on the amount of boiler evaporation, and the evaporation capacity of a single set may reach 10 tons.

The above-mentioned slurry feeding process is not using a spray gun. Therefore, the slurry casting method of the present invention is called: a slurryless gun casting method, and the boiler is also called a gunless coal water slurry boiler, which is different from the conventional spray gun. The freshest of the atomized coal water slurry boiler Ming features.

The specific construction of the ball drop machine (11) is not disclosed in the present application.

The specific construction of the ball raising machine (31) is not disclosed in the present application.

The specific construction of the boiler body and its respective evaporation tube rows (8, 9, 19) is not disclosed in the present application.

In order to make the refractory ball pass through the moving bed unhindered, the segments of the moving bed are purposely made downwardly divergent, the combustion chamber

The downward divergence of ( 23 ) is most obvious. The refractory ball down channel between the left and right evaporation tube rows (19, 8) and the middle evaporation tube row (9) installed in the combustion chamber (23) is also Made into this downward diverging shape, the moving bed has a rectangular cross section.

In the moving bed cooling section (24) there is a furnace door and ignition system (18).

The broken ball is dropped from the screen grille (12) to the grille (14) and removed from the broken ball outlet (13).

Here, the refractory ball does not only refer to a certain refractory ball, but includes all the refractory balls participating in the circulation in the moving bed. B The operation of the regenerative moving bed combustion unit:

See Figure 1: Flow chart of the regenerative moving bed boiler, Figure 2: Refractory ball moving bed and Figure 3: Regenerator L. The regenerator has two left and right seats, which are placed on both sides of the combustion chamber (23), respectively called regenerator R (34) and regenerator L (35), and the regenerator is equipped with a ceramic heat storage unit (29). There is a ash removal function, and the regenerator is provided with a regenerator ash port (27) for collecting the removed ash and recycling.

The self-ashing setting of the regenerator is one of the keys to the realization of the present invention.

The specific structure of the heat storage body is not disclosed in the present application.

The heat storage body accumulates the flue gas residual heat from the combustion chamber (23) that is not absorbed by the tube rows (8 or 19) on both sides of the combustion chamber (23), and the regenerator heats up and then releases the heat to preheat the flow. The combustion air of the regenerator, the combustion air participates in the combustion of the spherical fuel in the combustion chamber (23).

The moving speed of the moving bed is controlled by the ball drop machine (11). The spherical fuel is moved to the moving bed cooling section (24) to become a hot refractory ball with a layer of ash. It needs to be cooled and recovered to discharge the moving bed. Therefore, a cooling air is arranged at the bottom of the bed to be blown in from the refractory ball cooling air inlet (25), and rises to the combustion chamber (23) to participate in the combustion, which is distributed from the Roots blower air supply manifold. Under the control of the programmable controller, the four-way reversing valve (38) periodically changes the flow of flue gas and air, so that one regenerator is transferred from heat storage to heat release, and the other is exothermic to heat storage. These processes are repeated and cycled under the control of the programmer.

The regenerative moving bed boiler uses a Roots blower (36) to blow in the combustion air, and the Roots blower (36) has an air filter (37) in front. . It is worth mentioning that the regenerative moving bed combustion device here is a slurry oil containing high ash, such as coal water slurry, which contains much higher ash than petroleum products or natural gas. In the past, a regenerative combustion apparatus containing a higher ash-based slurry fuel such as a coal water slurry has not been disclosed.

Moreover, SMB boilers operate very reliably because the slurry supply system is greatly simplified:

SMB boilers do not need the front stabilizing chambers used in previous spray gun atomized coal-water slurry boilers, no high-temperature resistant refractories, no air compressors and slurry pumps in front of guns, fuel integration boxes, daily pulp A series of equipment such as cylinders and filters, the slurry supply system is greatly simplified, reducing the probability of failure.

In the past, the problem of ash removal and rapid boiler efficiency attenuation of coal-water slurry boilers atomized by spray guns is solved as follows: The ash referred to here is a pipe that is bonded or deposited in a convective heat transfer section in a boiler burning with a slurry fuel. The accumulation of ash, which will deteriorate the heat transfer conditions and reduce the efficiency of the boiler. On the one hand, the SMB boiler replaces the convective heat transfer section of the spray gun atomization boiler with the porcelain heat storage unit (29) of the regenerator, and the regenerator has the function of self-ash removal, and the ash removal capacity is lower than that of the soot blower. On the other hand, the spherical fuel in the combustion chamber (23) moves slowly downwards, much less than the fly ash in the atomization combustion mode of the spray gun, and the source of the ash is much less; the boiler efficiency is ensured.

The fresh air or flue gas nozzle (28) is a fresh air inlet or a flue gas outlet. When the regenerator is accumulating heat, it is a smoke outlet, and when it is released, it becomes an air inlet.

C Combustion Chamber (23) Necessity of setting the middle tube row:

See Figure 2: Refractory Ball Moving Bed and Figure 6: Graph of combustion temperature in the combustion chamber along the direction of flame flow. The boiler body of the regenerative moving bed boiler consists of left and right steam drums (21, 5), rising main pipe (6), descending main pipe (7), upper header (20), lower header (10), and evaporation pipe row (8, 9). , 19) composition. The upper header (20), the lower header (10), and the evaporation tube row (8, 9, 19) are installed in the combustion chamber (23), which is the entire radiant heat transfer surface of the boiler.

The high-temperature combustion air preheated by the left or right regenerator is blown laterally through the fuel layer from the left or right side of the combustion chamber (23) (see Figure 1), so that the fuel layer is combusted under the combustion of high temperature (generally 923K) intake. The ash melting point is generally 1573K. If the central tube row (9) is not provided, a large amount of excess air is required to control the peak burning temperature below the ash melting point (1573). Thus, the drum and the induced draft fan are better than others. A lot of boilers will waste a lot of power. When designing the boiler of the present invention, a plurality of sets of central tube rows (9) are arranged in the combustion chamber (23), so that the flame reaching the ash melting point temperature is cooled in time to obtain the middle tube row, and the combustion temperature is in the combustion chamber (23) along the flame. The graph of the direction of flow is shown in Figure 6. This figure shows an example of two sets of central tube rows in the combustion chamber (23). It can be seen that the temperature curve is stepped, and each combustion peak temperature is in flame. Above the row of the tube, it is below the ash melting point.

D refractory ball (1) Carrier cooling ash: See Figure 2: Refractory ball moving bed, Figure 4: Lifting machine arrangement and its ash discharge position map and Figure 5: Lifting machine and its ash discharge position.

The refractory ball here is only a carrier, a carrier that circulates the slurry fuel between the combustion chamber (23) and the pulp (2), and the heat of the refractory ball from the combustion chamber (23) is Recycling, the gray shell after the surface fuel is burned out, so the refractory ball cooling air (25) is blown from below the ball drop machine (11) to cool the downwardly moving refractory ball, and the ash shell on the refractory ball is in the liter The ball machine (31) is worn away during the conveyance of the pulp (2), and the ash that is ground is discharged from the ash outlet (30) of the ball lifting machine under the ball raising machine (31), thereby avoiding the accumulation of ash. The overcurrent gap between the balls in the combustion chamber (23) is blocked. The ash dropped from the ball drop machine (11) is discharged from the ball discharger (15) through the screw hopper (16) for centralized use.

When the water of the coal water slurry evaporates, steam is generated at the top of the preheating section (22), and the water evaporation heat of the coal water slurry is recovered by the following method.

In order to recover the moisture evaporation heat of the coal water slurry, the refractory ball cooling air is preheated by a finned air preheater (43), and then blown in from the refractory ball cooling air inlet (25) at the lower part of the moving bed.

In summary, it can be known that SMB boilers have the following four advantages that can improve boiler efficiency:

1. The SMB boiler can give the slurry fuel a residence time of more than one hour, and the residual carbon is very small.

2. There is no need to pre-stabilize the combustion chamber, there is no such heat loss.

3, there is no need to collect slag puddles, and there is no such heat loss.

4. Since the regenerator can be kept clean and can efficiently absorb and release heat, the exhaust gas temperature can be kept low, and the efficiency of the boiler is not attenuated. 5. The refractory ball of the boiler cools the air, and the moisture of the water of the coal water slurry can be recovered.

The above five points enable the boiler efficiency to be fully improved.

SMB boilers can replace coal-fired boilers:

SMB boilers can replace various industrial coal-fired boilers and will obtain good environmental and economic benefits. It is not difficult to understand from the facts recognized by some industry insiders:

Traditional industrial boilers have a large convective heat transfer section because of the smoke flow path. Soot or fly carbon will be extinguished here, and it will be discharged into black smoke. The black smoke contains a large amount of polycyclic aromatic hydrocarbons (P0M). Aromatic hydrocarbons (POMs) are a class of emissions that cause cancer, as well as S0 ₂ that produces acid rain and damages the respiratory system. This is because the combustion chamber (23) of the SMB boiler is a stable stable combustion chamber, and the oxygen concentration is above 10%, ensuring that the flame extends to the upper part of the regenerator, and the flying carbon has a long enough stay in the flame zone. Time, can burn black smoke. BRIEF DESCRIPTION OF THE DRAWINGS:

See the drawings 1, 2, 3, 4, 5, 6, and 7.

Figure 1 is a working flow chart of a regenerative moving bed boiler, Figure 2 is a refractory ball moving bed (33 in Figure 1), Figure 3 is a regenerator L (34 in Figure 1), Figure 4 is a lifting machine arrangement and The position of the ash discharge port (left view of the cross section of Fig. 1), Fig. 5 is the schematic view of the position of the lifter and its ash discharge port (Fig. 1 is the front elevation of the façade), and Fig. 6 is the combustion temperature in the combustion chamber. The curve of the flow direction along the middle flame, and Fig. 7 is the outline of the heat storage moving bed boiler.

In the above figures, 1 is a refractory ball, 2 is a pulp, 3 is a slurry pipe, 4 is a refractory ball inlet, 5 is a right steam drum, 6 is a rising pipe, 7 is a down pipe, and 8 is a right side evaporation pipe row. 9 is the middle evaporation tube row, 10 is the lower header box, 11 is the ball drop machine, 12 is the screen ball grid, 13 is the broken ball outlet, 14 is the grille, 15 is the ball drop ash outlet, 16 is the spiral ash discharge machine, 17 is a ramp, 18 is the furnace door and ignition system, 19 is the left evaporation tube row, 20 is the upper header, 21 is the left steam drum, 22 is the preheating section, 23 is the combustion chamber, and .24 is the cooling section. 25 is the refractory ball cooling air inlet, 26 is the reclaiming pipe, 27 is the regenerator ash port, 28 is the fresh air or flue gas nozzle, 29 is the porcelain heat storage unit, 30 is the lifting machine ash outlet, 31 , is a lifting machine, 32 is a lifting tube, 33 is a refractory ball moving bed, 34 is a regenerator L, 35 is a regenerator R, 36 is a Roots blower, 37 is an air filter, 38 is a four-way exchange To the valve, 39 is an induced draft fan, 40 is a lightweight insulated refractory brick wall, 41 is an insulation layer, 42 is a steel plate skin, and 43 is a finned air preheater.

Claims

Rights request

1. A regenerative moving bed boiler without gun slurry, characterized in that: it is a refractory ball moving bed (33), a regenerator L (34), a regenerator R (35), a Roots blower ( 36), ball drop machine (11), ball raising machine (31), etc., the boiler can burn high and low ash content of slurry fuel without using a spray gun, and put the refractory ball into the furnace. The refractory ball is reused. , the circulation path is: Refractory ball (1) is lifted to the moving bed preheating section inlet (4) by the ball lifting machine (31), through the pulp (2), moving bed preheating section (22), combustion chamber ( 23), cooling section (24), during which the spherical fuel completes the process of heating, ignition, complete combustion, and cooling; then the ball grid (12) is dropped from the ball drop machine (11), rolled to the ramp (17), and then The ball lifting machine (31) is raised along the lifting pipe (32) to the moving bed preheating section inlet (4) to complete a cycle.

.

2. A gunless regenerative moving bed boiler according to claim 1, wherein: said boiler is a gunless coal water slurry boiler.

3. The gunless regenerative moving bed boiler according to claim 1, wherein the regenerator L (34) and the regenerator R (35) are provided with a similar regenerator set underneath. The ash port (27) is used for collecting the ash or the port. When working, the ash from the coal water slurry must be discharged from here.

4. The gunless regenerative moving bed boiler according to claim 1, wherein: the ash shell on the refractory ball is transported to the pulp (2) by the ball raising machine (31). After grinding off, the ground ash is discharged from the ash outlet (30) under the ball lifter (31).

5. The gunless regenerative moving bed boiler according to claim 1, wherein: the boiler is blown into the combustion air by a Roots blower (36), and one of the combustion air is used as a refractory ball cooling air. Blow in from the refractory ball cooling air inlet (25) in the lower part of the moving bed.

6. The gunless regenerative moving bed boiler according to claim 1, wherein: the combustion chamber (23) is provided with a plurality of sets of central tube rows (9), so that the flame reaching the ash melting point temperature is timely The cooling of the central tube row is obtained.

A gunless regenerative moving bed boiler according to claim 1, wherein: each of said sections of said refractory ball moving bed (33) is formed to be diverging downwardly or in a well-like shape, combustion chamber (23) The downward diverging shape is most obvious, and the refractory ball descending passage between the evaporation tube rows (8, 9, 19) installed in the combustion chamber (23) is also made into such a downwardly divergent shape, which is fire resistant. The cross section of the ball moving bed (33) is rectangular.