RU185159U1 - STEAM BOILER WITH A HEAVY WEIGHTED LAYER (FA) - Google Patents

Abstract

The utility model relates to the field of heat power engineering. The technical result achieved by the implementation of this utility model is to increase the boiler efficiency due to more efficient burning of solid fuel and increase the operational reliability of a steam boiler with a furnace device (furnace) and maintainability. A steam boiler with a TCS for burning solid fuel contains a power frame of the boiler, in which a furnace is installed with front and rear furnace screens, lower and upper drums connected by a convective tube bundle and located along the longitudinal axis of the boiler, lower and upper collectors of the furnace screens, lower of which from the bottom are connected to the pipes of the furnace screens, and the upper collectors from the top are connected to the pipes of the furnace screens, while the collectors are connected to the drums by means of lowering and steam pipes, while the furnace with holds the side furnace front and rear screens, each of which is divided into two screens: left and right, and is made with a water-cooled grate, on which there are replaceable cast-iron caps with openings made with the possibility of supply for efficient combustion of fuel under air pressure to create a fluidized bed , while in the base of the combustion chamber of the furnace installed TCS.

Description

The utility model relates to the field of power engineering, in particular to steam boilers, and can be used for burning low-calorie solid fuel.

Known steam boiler with a fluidized bed reactor containing a frame, mounted in the frame of the combustion chamber with front, rear and side walls, front, rear and side screens made of pipes, with upper and lower manifolds, while the rear screen at the level of the lower drum is made bent to the front wall and equipped with a festoon at the top, and one of the side screens in the upper part is bent to the other side screen with the formation of the ceiling screen of the combustion chamber, the device for burning fuel is boiling reactor about a layer with an air distribution grill installed under the combustion chamber, a fuel input device, an ablation return device, nozzles for supplying secondary air to the combustion chamber, a horizontal gas duct, bounded above and below by upper and lower drums, respectively, adjacent to the combustion chamber from the rear screen side, a convective superheater and an evaporation bundle located in a horizontal gas duct made of pipes connected at their ends to the upper and lower drums, respectively in regulating the temperature of the steam, characterized in that the screens, simultaneously being the walls of the combustion chamber and made of gas tight from pipes rigidly connected by spacers, are located over the entire area of the inner surface of the combustion chamber, while the boiler is equipped with a radiation-convective superheater installed on the front wall, the side pipes of the evaporation beam are rigidly connected by spacers with the formation of gas-tight side walls of the horizontal gas duct, and nozzles for supplying secondary air and preferably mounted on the side walls of the combustion chamber above the air distribution bars (RU 142006. 20.06.2014).

A disadvantage of the known boiler are:

- the complexity of manufacturing and installation due to the use of gas tight performance, a large number of assembly welds (caused by the installation feature), which determines the high complexity;

- a high rate of abrasive wear of the heating surfaces;

- repair becomes time-consuming, replacement of pipes will lead to long-term repair.

The technical problem to which the proposed utility model is aimed is to expand the arsenal of technical means and create a steam boiler for burning low-calorie solid fuel with the highest possible efficiency, in comparison with the known analogues of this type of boilers, the parameters of which eliminate the above disadvantages and provide improved operational characteristics.

The technical result achieved by the implementation of this utility model is to increase the boiler efficiency due to more efficient burning of solid fuel and increase the operational reliability of a steam boiler with a furnace device (furnace) and maintainability.

The specified technical result is achieved in a steam boiler with a fluidized bed furnace device (TCS) for burning solid fuel, containing a boiler power frame, in which a furnace is installed with front and rear furnace screens, lower and upper drums connected by a convective tube bundle and located along the longitudinal axis of the boiler, the lower and upper collectors of the furnace screens, the lower of which are connected from below to the pipes of the furnace screens, and the upper collectors from above are connected to the pipes of the furnace screens, while the projectors are connected to the drums by means of lowering and steam exhaust pipes, while the furnace contains side furnace front and rear screens, each of which is divided into two screens: left and right, and is made with a water-cooled grill, on which replaceable cast-iron caps with holes made with the possibility of supply for efficient combustion of fuel under air pressure to create a fluidized bed, while at the base of the combustion chamber of the furnace there is a TKS.

The side screens are equipped with mounting units for equipping the side screens with protective cast-iron elements to protect the heating surfaces “immersed” in the active combustion zone from abrasion.

The rear furnace screen in the upper half of the furnace is bent towards the front furnace screen with an angle of at least 15 ° to the horizontal section of the furnace with the organization of festoon piping in the bent section. Such a solution makes it possible to achieve uniformity of the gas flow and more complete heat perception by the heating surfaces.

The tubes of the furnace screens and the convective bundle of pipes are made of pipes Ø51 × 4.0 mm, which increases the overhaul period and the reliability of the boiler.

A convective tube bundle has a center distance of at least 3750 mm.

A convective tube bundle forms a convective block, under which there is an ablation return system from the bins, connected to the lower part of the rear furnace screen at a level of 1500 mm from the plane of the grate.

The convective block of the boiler forms a heating surface with a corridor arrangement of pipes to form an additional heating surface, which increases the efficiency of the boiler due to more efficient burning of solid fuel and increasing the operational reliability of a steam boiler with a furnace device (furnace with TKS).

The claimed utility model is aimed at creating a steam boiler with the highest possible efficiency, in comparison with the known analogues of this type of boilers, with high reliability of operation and maintainability. A TKS is installed in the furnace (furnace volume) of the boiler, which effectively organizes the heat of burned fuel, the design of the furnace and convective space allows to achieve high rates of heat perception by heating surfaces, and reduces the possibility of stagnant zones; a larger furnace volume together with secondary blasting allows to increase the residence time of coal particles in the combustion zone, which contributes to its more complete burnout and increased boiler efficiency; the cross section for the passage of flue gases in the convective beam is selected with a lower gas velocity, which allows to achieve less abrasive wear and increase the service life of the heating surfaces. These speeds also make it possible to achieve gravitational separation of unburned fuel particles and the return of the ablation system to burnout by the system, which leads to an increase in boiler efficiency; the implementation of the furnace with replaceable specially designed cast-iron caps with holes through which the necessary amount of air for efficient fuel combustion is supplied under pressure creates a fluidized (boiling) bed, which increases the efficiency of fuel combustion.

The essence of the utility model is illustrated by drawings, where in FIG. 1 shows a General view of a steam boiler with TCS for burning solid fuel; figure 2 - section aa in fig. one; in FIG. 3 is a schematic diagram of a steam boiler with a TCS for burning solid fuel.

A steam boiler 1 with TCS 2 for burning solid fuel is a single block design based on a supporting metal structure - a base (a single base (power frame of the boiler 1) will allow a more accurate connection of the furnace screens and convective beam). The block construction consists of a pipe system, sets of pipelines of steam and water, an external casing of sheathing and insulation, a furnace with TCS, an ablation return system; a set of mounted maintenance metal structures (platforms, platforms and stairs) and metal structures providing air and fuel supply to the furnace and removal of focal products of combustion. Fuel is supplied from the front of the steam boiler.

The external frame of the boiler is a single prefabricated metal structure which is the supporting base of the furnace, convection blocks of the boiler. Also, the external frame is a supporting structure for installing insulation, cladding sheets and suspended metal structures, providing free access for maintenance personnel to the elements of the boiler.

The steam boiler 1 with TKS 2 provides a fuel input box 3 and contains a shielded firebox with side 6, front 5, rear 7 furnace screens, upper 9 and lower 10 drums connected by a convective bundle of pipes 8. Moreover, the pipes of the furnace screens from the bottom are connected to the lower collectors, and on top are connected to the upper collectors. The convection unit at the base is equipped with boxes of the ablation return system 11, connected to the blower fan, which ensures the return of entrained unburnt particles to the furnace zone with a high gas flow temperature. In the base of the furnace (combustion chamber), TKS 2 is installed, having fasteners on the sides allowing it to be tightly adjacent to the boiler screens.

A set of furnace screens (tube panels) 5-7 is a furnace block and is mounted on a metal structure that provides reliable assembly into a single boiler unit, which serves as a frame for attaching insulation and cladding sheets. Side furnace screens 6 are front 5 and rear 7 screens, each of which is divided into two screens: left and right. Thus, the front furnace block is made of three furnace screens: front 5 (front), side front left 4 and side front right 12, and the rear block is also made of three furnace screens: rear 7, side rear left 13 and side rear right 14 .

All furnace screens are formed by a set of pipes of complex shape installed in parallel (deviating from a straight shape and bending at several angles) with a diameter of 51 mm with a wall thickness of at least 4 mm, fixed by a weld in at least two collectors with a diameter of 219 mm and a wall thickness of at least 8 mm. The step between the pipes in the panel is 55 m. The pipes are bent at the junction with the collector and inserted into it forming a checkerboard row. The clearance in the light between the forming pipes in the panel is 4 mm. Screens 6 and 7 have fixing units in the base of the furnace for installing protective cast-iron elements 15 (see Fig. 2), which prevents abrasive wear of the screen tubes.

Moreover, the rear furnace screen 7 is bent towards the front furnace screen 5 with the formation of an aerodynamic protrusion, below the aerodynamic protrusion it is inclined at an angle of 15–30 ° to the longitudinal axis of the boiler 1, in the upper half of the furnace it is bent towards the convective tube bundle 8 parallel to the front furnace screen 5 with the organization of festoon wiring pipes in the bent section.

The firebox block has the following geometric dimensions:

1. Front screen 5: 1660 mm wide along the axes of the lower collectors, 230 mm wide along the axes of the upper collectors and 8010 mm in height along the axes between the lower and upper collectors. The height of the front screen 5 along the axes of the collectors is not 4000 mm, depending on the conditions of combustion. The lateral front right screen 12 in the upper part is bent towards the side of the front front left screen 4 at an angle of twelve (12) degrees relative to the horizon. In the lower part, the side screens 6 (4, 12) have a pipe bend into the inner volume of the furnace and form a geometry in the base that provides a tight fit to the TCS 2. The lower part of the pipe of the side screens 6 is bent by thirteen (13) degrees.

2. Rear screen 7: 2930 mm wide along the axes of the lower collectors, 230 mm wide along the axes of the upper collectors and 4930 mm high along the axes between the lower and upper collectors. The height of the rear screen 7 is 6310 mm along the axes between the lower and upper collectors. The lateral rear right screen 14 in the upper part is bent towards the side of the rear rear left screen 13 at an angle of twelve (12) degrees relative to the horizon. The rear screen 7 has a complex geometric shape with a depth (in the longitudinal section of the block) of 2335 mm along the axes of the pipes. At the base of the screen 7, pipes emanating from the lower headers are bent to the rear at an angle of forty-eight (48) degrees to the horizon, passing into a vertical section of at least 690 mm in length, followed by bending them to the front of the screen 5 at an angle of 15–30 ° to the longitudinal axis of the boiler 1. In the upper part, a vertical section is made forming the festoon of boiler 1 (the evaporative heating surface at the outlet of the furnace).

The convective bundle of pipes 8 forms a convective block, under which there is an ablation return system 11 from the bins, connected to the lower part of the rear furnace screen 7 at a level of 1500 mm from the plane of the water-cooled grate.

The convective block of the boiler forms a heating surface with a corridor arrangement of pipes. Convective beam tubes are introduced into the upper 9 and lower 10 drums. The longitudinal and transverse pitch of the beam is 95 mm and 110 mm. The distance along the axes of the drums is 3750 mm.

The convective unit has a base in the form of a metal structure, a protruding supporting structure for insulation and a sheathing sheet.

Convective beam pipes 8 are made of pipes Ø51 × 4.0 mm with a pitch of 95 mm along the boiler drum and in the convective beam cross section with a pitch of 110 mm, the center distance between the drums 9 and 10 with an inner diameter of 1000 mm is 3750 mm.

TKS 2 is an air box, the dimensions of which are similar to the cross section of the furnace, with inclined walls and a water-cooled grill to protect it from high temperatures. On the grate are replaceable specially designed cast-iron caps with holes through which the necessary amount of air is supplied under pressure to efficiently burn the fuel, creating a fluidized (boiling) bed.

To organize air jets, replaceable cast-iron caps on the grill are installed in the corridor order, which makes the caps repairable by the efforts of their own personnel. Air is supplied to the TKS 2 firebox from a high-pressure fan from the bottom of the air box and through a kindling device. Air is supplied to the furnace at ambient temperature.

Thus, the above design provides a balanced state of the layer and fuel burnout.

Inside, the air box is protected by insulation from refractory bricks, in the case of installing a kindling chamber.

The lattice and the drain pipes of the layer are cooled by separate circuits with chemically purified water with a pressure of not more than 0.6 MPa (6.0 kgf / cm ² ) and an inlet temperature of not more than 20 ° C, and at the outlet no more than 60 ° C. Water consumption for cooling the furnace and drain pipes of the layer 2-5t / h. Maintaining the set temperatures is provided by changing the flow rate of water through the grate. The water heated during cooling is used for the boiler plant’s own needs. Pipelines for supplying and discharging cooling water to the water-cooled grate and layer drain pipes are made of pipes Ø38x3 mm. A water-cooled grate and layer drain pipes are connected in series through the water. In some cases, for visual inspection, it is possible to install a device with a jet break (not shown) on the outlet pipeline.

To completely burn out combustible gases and reduce NOx emissions into the atmosphere, a secondary blast is installed from the front 16, at an altitude of 4500 mm.

In addition, from the convection beam 8 of 6 ash bins using the ablation return system 11 (IED) into the furnace at an altitude of 1,500 mm from the plane of the grate, the entry of unburnt particles is carried out. Nozzles 26 installed on the rear screen 7 of the furnace, contribute to the ejection of the particles of entrainment and return them to burnout.

The boilers used a single-stage evaporation scheme (see Fig. 3), the main elements of which are the upper and lower drums with an inner diameter of 1000 mm, a convective tube bundle, front, rear, side (front and rear left, front and rear right) screens. Water circulates as follows: feed water is supplied to the upper drum 9 under the water level of the perforated pipe. In the lower drum 10, the water is discharged through the rear heated pipes (bypass pipes) of the convective beam (boiling beam). The front of the beam (from the front of the boiler) is lifting. From the lower drum 10, the water through the bypass pipes 17 enters the lower chambers 18 of the side front 4 and rear 12 left screens, side front 12 and rear 14 right screens, front 5 and rear 7 screens. Products of pairs from the upper chambers 19 of the side front 4 and rear 12 left screens, side front 12 and rear 14 right screens, front 5 and rear 7 screens through steam pipes 20 enter the upper drum 9. On the lower chambers 18 of the screens there are fittings for purging them 21.

The separation device is located in the upper drum 9. The primary separation is located in the baffle plates with visors. The steam is finally cleaned of moisture by a horizontal louvre separator located at a distance of 300 mm from the average water level in the drum. A uniform supply of steam to the louvre separator is provided by a hole sheet with holes located above it.

The boiler is equipped with instrumentation and necessary fittings. The boiler has three safety valves, one of which is a control valve. Safety devices 22, sampling pipes, direct-acting water indicating device pipes 23, low-level indicator device pipes and the main steam valve 24 are located on the upper drum 9. Continuous blowing pipes are also provided in the upper drum 9.

The lower drum 10 is equipped with a heating pipe and periodic purge pipes.

The boiler is designed to work together with the tail heating surface - an economizer 25 (ЭЧ-1090), the heating surface area of which is determined by calculations depending on the quality of the fuel burned, at least 800 m ² .

The claimed utility model provides the ability to operate a steam boiler with low-quality and high-quality coals with a high coefficient of efficiency, compared with the known analogues of this type of boilers.

Claims (7)

1. A steam boiler with a fluidized bed furnace device (TCS) for burning solid fuel, comprising a furnace with side, front, rear furnace screens, the pipes of the furnace screens being connected to lower collectors from below and upper and lower drums connected to upper collectors, interconnected by a convective bundle of pipes, while the collectors are connected to the drums by means of lowering and steam pipes, characterized in that a TCS is installed at the base of the furnace, which is an air box with inclined walls and a water-cooled grate, on which there are replaceable cast-iron caps with holes made with the possibility of supplying air under pressure from a fan located at the bottom of the air box, while the convective bundle of pipes forms a convective block, under which there is an ablation return system from bunkers, connected to the bottom of the rear furnace screen with the possibility of returning carried away unburned particles to the furnace zone. 2. A steam boiler with a TCS according to claim 1, characterized in that the side screens are equipped with mounting units for equipping the side screens with cast-iron protective elements to prevent the heating surface from being abrasive, “immersed” in the active combustion zone. 3. A steam boiler with a TCS according to claim 1, characterized in that the rear furnace screen in the upper half of the furnace is bent towards the front furnace screen with an angle of at least 15 ° to the horizontal section of the furnace with the organization of festoon pipe routing in the bent section. 4. A steam boiler with TKS according to claim 1, characterized in that the furnace screens and the convective bundle of pipes are made of pipes ∅51 × 4.0 mm. 5. A steam boiler with a TCS according to claim 4, characterized in that the convective bundle of pipes has a center distance of at least 3750 mm. 6. A steam boiler with a TCS according to claim 5, characterized in that the system for returning the ablation from the bunkers is connected to the lower part of the rear furnace screen at a level of 1500 mm from the plane of the grate. 7. A steam boiler with a TCS according to claim 1, characterized in that the convective block of the boiler forms a heating surface with a corridor arrangement of pipes.

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