RU69201U1 - WATER AND GAS BOILER OF SMALL POWER WITH A HEAT OF A HIGH-TEMPERATURE BOILING LAYER - Google Patents

Abstract

The utility model relates to the field of heat power engineering. The boiler unit consists of a mechanical furnace device in the form of a narrow, mobile, straight-ahead grate, which implements the technology of burning fuel in a high-temperature fluidized bed, heating surfaces, fuel feeder, ejector. Fuel is supplied by a scraper feeder to an inclined plate and further to the furnace. On-screen heating surfaces are steel gas-tight water-tube screens, convective heating surfaces are made in the form of two gas-tube sections, which provide a turn of gases in a vertical plane and the deposition of unburned particles of fuel and fly ash in gases in an ablation recovery hopper with an ejector. A two-stage air supply was used: under the grate through the blast zones of primary air and into the superlayer space through nozzles of the secondary blast. Using the ejector, the ablation is returned to the furnace for afterburning. In the combustion chamber along the grate, an additional heating surface (cooling panel) is installed, which is included in the boiler circulation circuit. The cooling panel is made of a series of pipes, placed one above the other, and has a U-shaped layout in plan.

Description

The utility model relates to the field of heat power engineering.

Known boiler with a furnace for burning solid fuel in a fluidized bed design "Ignifluid" [1]. The furnace consists of a narrow, movable grate, inclined to the horizon by 10-15 °. Air for fluidization of the layer is supplied through a grate from an air box, divided into sections, in each of which a predetermined pressure is maintained. Seals of the grate at the front and side walls of the furnace are achieved by natural slag filling, which borders the fluidized bed and protects the furnace from overheating. The system of pipes cooled by water located inside prevents slagging of the layer, holds backfill on each side of the grate and directs the flow of slag [2].

Known boiler with a furnace of a high-temperature fluidized bed [3]. The boiler unit consists of a mechanical furnace device in the form of a narrow, mobile, straight-ahead grate, which implements the technology of burning fuel in a high-temperature fluidized bed, heating surfaces, fuel feeder, ejector. A two-stage air supply was used: under the grate through the blast zones of primary air and into the superlayer space through nozzles of the secondary blast.

This analogue has several disadvantages:

- low maintainability;

- low reliability (burnout of pipes);

- deterioration of heat transfer during operation due to clogging of convective heating surfaces;

- water-tube heating surfaces require heavy lining, which increases the overall dimensions of the boiler;

The objective of the utility model is to increase the reliability, efficiency and maintainability of the boiler.

This problem is solved due to the fact that:

1. The use of gas pipe sections reduces the overall dimensions of the boiler due to the absence of heavy lining for convective heating surfaces and its replacement with heat-insulating panels. This is possible due to a decrease in heat flux due to a decrease in the temperature difference inside and outside the lining.

2. Heat exchange improves, since there is no clogging of the heating surfaces with unburned soot particles and particles of fly ash due to the vertical arrangement of the pipes and their longitudinal washing off with flue gases, as well as due to an increase in the rate of combustion products.

3. The reliability of the boiler unit increases due to the absence of temperature distortions in the heat exchange surfaces of the gas pipe sections, leading to burnout of the pipes. This is due to less clogging of the heating surfaces with burnt particles of fuel and fly ash.

4. The maintainability of the boiler is increased. In the event of emergencies associated with the failure of the pipe of the gas pipe section, this pipe is removed directly, followed by a plug, and not the whole sections are removed, as is the case for the boiler described in the literature [3]. Also, maintainability of the boiler is increased due to more convenient

cleaning of heating surfaces and the absence of special devices for this.

The proposed boiler design is not identified from the existing level of technology. This allows us to conclude that it meets the criterion of "novelty."

The proposed design of the boiler is illustrated by the drawing shown in figure 1. The boiler includes a mechanical furnace device, heating surfaces, a scraped fuel feeder, an ablation return hopper and an ejector. The main technological element of the furnace is a narrow, movable, grate forward-facing grate (6). This device also includes a frame with an air box located inside it, divided into primary air blast zones (4), as well as lateral and transverse (interzone) seals. To control the temperature level in a fluidized bed, a cooling panel (5) is installed.

The furnace is bounded on the sides and top by steel gas-tight water-tube screens (13). Fuel is fed to the forward grate from the fuel hopper (8) along an inclined plate (9) using a scraped fuel feeder (12).

A two-stage air supply is used. Part of the air goes under the direct-fire grate through the blast zones of primary air (4), and the other into the superlayer space through the secondary blast nozzles (7).

The following gas movement pattern is organized in the boiler. Gases rise from the straight-through grate to the top of the furnace, pass down a series of parallel pipes of the gas pipe section (1), rotate 180 ° and, passing up the gas pipe section (2), are removed from the boiler. To ensure the flue gas turn between the gas pipe sections (1) and (2), a heat-resistant partition is installed

steel (10). A sharp turn of the gases allows the unburnt particles of fuel and fly ash removed from the furnace to be sedimented in the entrainment return bunker (3) and returned to the afterburning furnace using the ejector (11).

1. A.P. Baskakov and others. Boilers and furnaces with a fluidized bed. M .: Energoatomizdat, 1995, p. 260.

2. AP Baskakov and others. Boilers and furnaces with a fluidized bed. M .: Energoatomizdat, 1995, p. 263.

3. Smirnov A.V. and others. A boiler unit for the combustion of coal in a fluidized bed. Utility Model Patent. Registered in the State Register of Utility Models of the Russian Federation on May 20, 2004 No. 38041, bull. No. 14.

Claims (1)

Coal burning boiler, consisting of a mechanical combustion device, heating surfaces, fuel feeder, characterized in that the convective heating surfaces are made in the form of two gas pipe sections, which provide a vertical turn of gases and the deposition of unburned particles of fuel and fly ash in the gases ablation return hopper with ejector.