RU2252367C1 - Water-heating tank - Google Patents

Abstract

FIELD: power engineering.

SUBSTANCE: device has furnace, after-burn hollow, screen and convection bunches of water-heating pipes. Water cylindrical space between sides of furnace is separated by two diametrically opposite walls on two separated semi-cylindrical water hollows. Special piece is connected to lower bottom of furnace in axial-symmetrical way and made in form truncated cone. Burners are mounted tangentially at side surface of furnace close to its upper bottom with direction of axes of burners touching the circle, diameter of which is twice lesser than inner diameter of furnace. Water hollow of after-burn chamber is connected to semi-cylindrical water hollow adjacent to it from lower portion. Furnace through outlet port placed on its side surface in lower portion is connected to after-burn chamber, connected to convective gas line. Convective gas line is formed on inner side of outer cylindrical side of furnace, and on outer sides - by bottoms of respectively upper and lower ring-shaped water collectors and outer semi-side of gas line, mounted in high-temperature zone of gas line close to after-burn chamber outside with additional water hollow, connected to water hollow of after-burn chamber and limited by its bottoms and outer wall. Inside the convective gas line rows of vertical water-heating convective pipes are mounted, connected to upper and lower ring-shaped water collectors. Flow branch-pipe connects inlet of heated water in lower ring-shaped water collector to output of it from semi-cylindrical water hollow.

EFFECT: higher reliability.

2 cl, 3 dwg

Description

The invention relates to the field of power engineering, and specifically to boiler building, and can be used in hot water boilers using various types of gaseous and liquid fuels, mainly water-coal suspensions.

Known hot water boiler "Luga" containing a furnace with a screen surface for heat exchange and a flue with a convective heat exchange surface, designed to work on fuel oil and transferred to work with coal-water fuel by installing an additional prechamber to which air and fuel are supplied, followed by supply of combustion products from a prechamber to a furnace during their subsequent combustion in it (Zaydenvarg V.E., Trubetskoy K.N., Murko V.I., Nekhoroshiy I.X. Production and use of coal-water fuel. M: Publisher A Adem of Mining Science, 2001, s.86-87).

The disadvantages of the known boiler are:

- Insufficient fitness of the boiler for burning “water-coal fuel (water-coal suspensions), which leads to the need to use an additional pre-chamber

- the use of the boiler furnace and as a fuel afterburning chamber located behind the prechamber is inefficient, since the furnace has a large volume with a high degree of shielding, which leads to an excessive decrease in the temperature of the combustion products and insufficient completeness of the final stage of combustion;

- the absence of ash collection and ash removal systems, which reduces the duration and reliability of the boiler, an accident has been noted.

These disadvantages limit the use of known hot water boilers when burning water-coal suspensions.

Known liquid fuel steel hot water boiler VVD-1.8, retrofitted to work on a water-fuel suspension, containing a vertical cylindrical firebox coated with thermal insulation, with a afterburning cavity with a developed surface of radiation heat transfer. The firebox is bounded by the upper and lower bottoms of the firebox with heat insulation, and on the side surface by the inner and outer cylindrical shells of the firebox with the formation of a cylindrical water space between them, bounded by the corresponding bottoms from its upper and lower zones. The boiler also contains screen water pipes communicating at the ends with the upper and lower water collectors of the screen pipes; convective hot water pipes; burner devices for feeding solar oil and air for spraying it into the furnace (for kindling the boiler), as well as water-coal fuel (for boiler operation); nozzles for supplying blast air; an ash pan on the side of the furnace and a convective flue; nozzles for supplying source water to the area of the end of the gas duct and the outlet of heated water from the area of the middle part of the boiler (see ibid., pp. 99-101). This boiler, as the closest, is selected as a prototype of the proposed solution for most of the features.

The disadvantages of the known boiler are:

- poor mixture formation and preparation of fuel for combustion in the furnace, due to the separate introduction of a water-carbon suspension along the axis of the furnace and blast air along the periphery of the cylindrical shell into the furnace;

- it is difficult to discharge the ash through the ash pan (located on the side surface of the furnace), which contributes to the accumulation of ash on the lower bottom and in the convection duct of the boiler with its emission in the exhaust gases, which, in turn, complicates the cleaning of the boiler from ash and worsens the heat transfer process;

- insufficient heat in the furnace, in which the fuel combustion process moves to the afterburner, which is equipped with a developed surface of radiation heat transfer, which reduces the combustion temperature and worsens the final stage of fuel combustion;

- a water conduit (made according to a counterflow circuit with a source of low-temperature source water from the convective heat exchange surface located at the end of the duct with a low gas flow temperature), despite a slight increase in heat transfer efficiency, determines the formation of condensate on the heat exchange surface with its subsequent corrosion with gas side.

Thus, the prototype hot water boiler has significant design flaws that reduce the technical and economic performance of the boiler, especially when burning water-coal suspensions.

The task to be solved by the claimed invention is directed is the elimination of the indicated technical, economic and structural disadvantages, namely:

- improvement of heat in the furnace;

- improvement of mixture formation and preparation of fuel for combustion in the furnace;

- improving the efficiency of convective heat transfer;

- improving the cleaning of the boiler from ash, improving the quality of cleaning and reducing the concentration of ash particles in the exhaust gases of the boiler;

- increase the resource of the convective heat exchange surface of the gas duct and the boiler as a whole.

The task is achieved by the fact that in the well-known hot water boiler VVD-1,8, containing a vertical cylindrical firebox coated with thermal insulation, with a afterburning cavity limited by the upper and lower bottoms of the firebox with thermal insulation, and from the side surface, the inner and outer cylindrical shells of the firebox with the formation between them of a cylindrical water space, limited from the upper and lower zones by corresponding bottoms, and also containing screen and convective bundles of water pipes, water collectors, Christmas-tree devices for kindling and operating the boiler with fuel and air supply pipes, an ash pan, a convective gas duct and pipes for supplying the source and removal of heated water, in contrast to it, the afterburning chamber is limited by a double-walled chamber adjacent to the furnace and similar bottoms with the formation of a chamber water cavity between them afterburning. The volume of the combustion space significantly exceeds the volume of the afterburner. The cylindrical water space between the shells of the furnace is divided by two diametrically opposite partitions into two semicylindrical water cavities disconnected from each other. On the upper bottom of the furnace there are attached screen water pipes communicated with their extremities, respectively, with the mentioned opposite semi-cylindrical water cavities.

The ash pan is fixed to the bottom of the furnace axisymmetrically and is made in the form of a truncated cone. The burner devices of the boiler are installed tangentially on the side surface of the furnace near its upper bottom with the direction of the axes of the burner devices in relation to a circle whose diameter is half the inner diameter of the furnace. The water cavity of the afterburning chamber is in communication with a semi-cylindrical water cavity adjacent to it from below. The furnace through the outlet window located on its lateral surface in the lower part is in communication with the afterburner, which communicates with the convection duct. The convective flue is formed on the inside of the outer cylindrical shell of the furnace, and on the outside by the bottoms of the upper and lower annular water collectors and the outer half-shell of the duct, equipped in the high-temperature region of the duct near the afterburner with an additional water cavity in communication with the water cavity of the afterburner their bottoms and outer wall. Rows of vertical hot-water convective pipes connected at the extremities with the upper and lower annular water collectors are installed inside the convective gas duct. Moreover, the boiler includes a source of water supply, mounted on the outer wall of the additional water cavity, a bypass pipe connecting the input of the heated water in the lower ring water collector with its outlet from the semi-cylindrical water cavity, and the pipe of the outlet of heated water from the boiler, mounted on the upper ring water collector. It is advisable to carry out a convective gas duct in the particular case in which the convective gas duct exit is equipped with a gas guide and is connected to the vortex chamber of the smoke box, which in the lower part is equipped with a truncated cone-shaped exhaust ash pan containing twin ash discharge flaps.

The claimed combination of restrictive and distinctive features improves the technical, economic, operational and structural characteristics of the boiler.

An increase in the volume of the furnace space by several times compared with the volume of the afterburner allows for more complete combustion of the fuel in the furnace due to an increase in the temperature of the combustion products with acceleration of the physical processes of mixture formation and chemical oxidation reactions, and in the afterburner, only the incomplete combustion products are burned out.

The tangential placement of the burner devices on the cylindrical surface of the furnace near the upper bottom with the axial flow direction tangential to a circle whose diameter is two times smaller than the internal diameter of the furnace allows for the vortex movement of the air-fuel mixture, reduce the time and increase the completeness of fuel burnout in the furnace.

The supply of a cylindrical water cavity between the outer and inner shells of the furnace with two vertical partitions, dividing the water space of the furnace into two independent cavities, makes it possible to organize the movement of heated water along these cavities independently and at a greater speed by reducing the cross-sectional area, which prevents the occurrence of stagnant zones with local overheating of water and cylindrical shells.

The supply of the furnace along the upper bottom with screen water pipes connected by their extremities (through the upper bottom of the said cavities) with the cylindrical water space of the furnace allows, firstly, to use them as a radiation heat exchange surface, and secondly, to provide free laying of brick insulation along the upper generatrix pipes without special ceiling mounts, and thirdly, to ensure uniform supply and removal of heated water along the indicated cavities of the cylindrical water space.

Supply of the furnace along the bottom with an axisymmetric conical (truncated cone) surface of the ash pan decreasing in diameter allows the ash to be removed from the furnace without the risk of depositing ash on the bottom and to reduce the ash outflow into the flues of the afterburner and the convective heat exchange surface.

The surroundings of the afterburning chamber with a cooling water cavity (limited by a double-walled space) allows for the mixing of products of incomplete combustion of fuel and their complete burning out in the chamber volume, as well as the uniform entry of the gas flow into the convection duct.

Supply of convective duct with rows of vertical pipes in communication with annular upper and lower water collectors, with restrictive surfaces of its channel in the form of an outer shell of a cylindrical water chamber of the furnace, upper and lower bottoms of annular collectors, and an outer half-shell of a duct provided with a water cavity in the high-temperature region of the duct, limited by a water cavity with its bottoms and external wall, it allows, firstly, to optimize the speed of the gas flow in the convective gas duct, and secondly, to reduce the external d diameter of the boiler and, thirdly, an external cylindrical shroud cavity furnace water as an additional convective heat transfer surface, which ultimately reduces the heat exchange surface of pipes.

Providing the exit of the convective gas duct in its private form with a gas guide shield and communication with the vortex chamber of the smoke box equipped with a conical exhaust ash pan in the lower part containing twin ash discharge flaps allows to further reduce the concentration of ash particles in the boiler exhaust gases and remove them from this ash pan, including during the operation of the smoke exhaust, which allows to reduce the aerodynamic resistance of gas treatment devices.

The location of the conduit according to the forward flow diagram with the source water supply pipe sequentially placed along the heated water, the water cavities of the external half-shell of the convective gas duct, the afterburning chamber, one of the half of the cylindrical cavity of the furnace, screen pipes, the other half of the cylindrical cavity of the furnace, the bypass pipe, the lower ring collector, convective tube bundle, upper annular collector, heated water outlet pipe reduces the likelihood of aggressive condensation forming on convective heat transfer surfaces of the boiler and, as a consequence, to increase its life.

Thus, an improvement is achieved in the structural, technical, economic and operational characteristics of the boiler when a number of additional effects appear.

The claimed technical solution is illustrated by the following illustrations. Figure 1 presents a diagram of a longitudinal section of a boiler, figure 2 is a diagram of a cross section (section aa according to view of figure 1) of a boiler, figure 3 is a section bb according to view of figure 2.

The boiler has the following device. The boiler contains a vertical cylindrical firebox 1, bounded by the upper bottom 2 with screen water pipes 3 and a fuel oil kindling burner 4. The lowering bottom 5 bounding the firebox 1 from the bottom has an axisymmetrically mounted and made in the form of a truncated cone ash pan 6. Firebox from all sides (around the perimeter) equipped with thermal insulation 7, around which the inner 8 and outer 9 cylindrical shells are placed along the lateral surface with the formation of a cylindrical water space between them, limited to the top it and its lower zones (extremities) with the corresponding bottoms 10 and 11 and filled with heated water. Two diametrically opposite vertical partitions 12 divide the specified water space into two independent semi-cylindrical water halves (cavities) 13 and 14. Screen water pipes 3 communicate (not shown) with their extremities through the upper bottom 10 with water cavities of the halves 13 and 14, respectively.

Two burner devices 15 supplying a water-coal slurry and blast air to the furnace are placed along the generatrix of the external lateral cylindrical surface of the furnace near the upper bottom 2 with an axial flow direction tangential to circle 16, the diameter of which is two times smaller than the internal diameter of the furnace.

The outlet window 17 of the furnace 1, located on its outer side surface near the bottom of the furnace, is communicated with an afterburner 18 located on the outside, which is externally limited by a cavity 19, bounded by an inner 20 and an outer 21 walls (half-ring vertical shells) with a height equal to the height of the furnace (not shown) and, accordingly, two-layer bottoms filled with heated water.

The afterburner 18 is in communication with a convective gas duct 22 containing rows of vertical convective hot water pipes 23 connected by extremities with annular upper 24 and lower 25 water collectors, the lower of which is freely mounted on the foundation support of the boiler, and the upper one rests on the ends of the pipes 23 (not shown) . The bounding surfaces of the channel of the convection duct 22 are formed by the outer shell 9 of the furnace 1, the upper and lower bottoms of the annular collectors 24 and 25, and the outer half shell 26 of the duct, provided in the region of the afterburner and the high-temperature region of the duct with an additional water cavity 27. Moreover, this cavity 27 is bounded from the inside part of the half shell 26 and the outside - the outer wall 28 and the bottoms (not shown). The outlet of the convective gas duct is equipped with a gas guide shield 29 and is in communication with a vortex chamber 30 of a chimney box (not shown), which in the lower part is equipped with an exhaust ash pan 31 in the form of a truncated cone with a storage tank 32 containing paired shutters 33 for filling and unloading ash.

The boiler conduit is formed by elements sequentially placed along the heated water: the source water supply pipe 34 directly to the additional water cavity 27 and the water cavities successively communicated (not shown) to each other - walls 28 (cavity 27), afterburner 18 (cavity 19), semi-cylindrical a water cavity 13 adjacent to the cavity 19 of the bottom combustion chamber (not shown), screen water pipes 3, a semi-cylindrical water cavity 14, a bypass pipe (between the cavity 14 and the annular collector 25), 35 awns annular collector 25 (lower), the series of convective hot water pipe 23, the annular manifold 24 (upper) and the drainage pipe 36.

A hot water boiler is used as follows. When the boiler starts operation, air from the boiler fan and fuel oil from the fuel pump (not shown) in the direction of the arrows 37 and 38, respectively, are supplied to the kindling burner device 4, which is included in the operation. After heating the thermal insulation 7, burner devices 15 are launched into operation with the supply of a water-coal slurry in the direction of arrow 39 and the burner device 4 is turned off. Due to the direction of the axes of the burners 15, a vortex fuel combustion process occurs in the fuel-air mixture torch with the formation of fuel combustion products, which are fed through the exhaust window 17 to the afterburner 18. Gold particles of fuel in the swirl flow of the furnace are pressed against the cylindrical surface of thermal insulation 7 and under the action of gravity move to the ash pan 6. A certain amount of air is also supplied to the afterburner 18 through the nozzle 40 and the blower 41 for complete combustion of the fuel. The combustion products then follow through the flue of the convective heat transfer surface and are cooled. Cooled combustion products by means of a gas guide shield 29 are introduced into the vortex chamber 30 of the smoke box, where large ash particles are separated from the stream. The cleaned gases are discharged in the direction of arrow 42 to deep-cleaning devices (not shown), and the ash is moved by gravity through the ash pan 31 to the storage tank 32. When the tank 32 is full, the paired damper 33 is moved to the lower position, while the swirl chamber 30 with a vacuum pressure is disconnected from the tank 32 and the ash is unloaded from this tank. After unloading the ash from the tank 32, the shutter 33 is moved to the upper position and the process of separating the ash from the gas stream continues.

When the boiler starts up, the source water is supplied through the pipe 34, then the water passes sequentially through the cavity 27 of the high-temperature part of the gas duct, the cavity 19 of the afterburner, the cavity 13 flows through the screen tubes 3 into the cavity 14, from which through the pipe 35 it enters the lower ring collector 25 and then, through convective pipes 23, is discharged to the upper annular collector 24. Heated water is discharged from the boiler through the water outlet 36 to the consumer. At the same time, the conditions of direct-flow heat exchange between gases and water are ensured, which prevents the formation of aggressive condensate on the surface of the convective bundle of pipes 23 and increases the reliability of using a boiler on a coal-water suspension.

Cleaning convective pipes 23 from deposits is as follows. The bypass pipe 35 is disconnected and the gas guide shield 29 is disconnected from the vortex chamber 30 of the smoke box. By means of a lifting device (not shown), annular collectors 24 and 25 are lifted together with the pipes 23 above the upper bottom of the furnace 2, while providing free access to all elements of the convective beam and water cavities of the furnace and afterburner, which allows you to perform the necessary work. Installation of a convective beam to a regular place is carried out in the reverse order.

Claims (2)

1. A water boiler containing a vertical cylindrical furnace, covered with thermal insulation, with a afterburner, bounded by the upper and lower bottoms of the furnace with thermal insulation, and from the side surface - the inner and outer shells of the furnace with the formation of a cylindrical water space between them, limited from the upper and lower its zones with the corresponding bottoms, as well as containing screen and convective bundles of water pipes, water collectors, burners for kindling and operation of the boiler with fuel supply pipes and air, ash pan, convective gas duct and nozzles for supplying initial and discharging heated water, characterized in that the afterburning cavity is limited by a double-wall chamber and similar bottoms adjacent to the furnace with the formation of a water cavity between the afterburner; the volume of the combustion space significantly exceeds the volume of the afterburner; the water cylindrical space between the shells of the furnace is divided by two diametrically opposite partitions into two semicylindrical water cavities disconnected from each other; to the upper bottom of the furnace there are attached screen water pipes communicated with their extremities respectively to the mentioned opposite semi-cylindrical water cavities; the ash pan is fixed to the bottom of the furnace axisymmetrically and is made in the form of a truncated cone; the burner devices of the boiler are installed tangentially on the side surface of the furnace near its upper bottom with the direction of the axes of the burner devices in relation to a circle whose diameter is half that of the inner diameter of the furnace; the water cavity of the afterburner is in communication with a semicylindrical water cavity adjacent to it from below; the furnace through the outlet window located on its lateral surface in the lower part is in communication with the afterburner, which communicates with the convective gas duct; a convective duct is formed on the inside of the outer cylindrical shell of the furnace, and on the outside, by the bottoms of the upper and lower annular water collectors and the outer half-shell of the duct, equipped in the high-temperature region of the duct near the afterburner with an additional water cavity in communication with the water cavity of the afterburner their bottoms and outer wall; inside the convective gas duct there are rows of vertical hot-water convective pipes communicated at the ends with the upper and lower annular water collectors, the boiler comprising a source water supply pipe mounted on the outer wall of the additional water cavity, a bypass pipe connecting the inlet of the heated water in the lower ring water collector with its exit from the semi-cylindrical water cavity, and a pipe for removing heated water from the boiler, mounted on the upper ring water ring Héctor. 2. The hot water boiler according to claim 1, characterized in that the convection duct exit is equipped with a gas guide and communicates with the vortex chamber of the smoke box, which in the lower part is equipped with a truncated cone-shaped exhaust ash pan containing twin ash discharge flaps.

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