RU2383823C1 - High-temperature coaxial air heater-heat exchanger - Google Patents

Abstract

FIELD: heating.

SUBSTANCE: invention relates to air heaters with convective heat-recovery unit for high-temperature fume gases of thermal electric power stations. Proposed high-temperature coaxial air heater-heat exchanger comprises housing and channels for various-temperature airflows to pass through. In compliance with this invention, it additionally incorporates inlet branch pipe to feed in high-temperature flue gases from fluosolids furnace and outlet branch pipe to discharge flue gases. Note here that there is blast air housing arranged aligned with fume gas housing to allow airflow from blow fan to pass through branch pipe and into furnace. Note also that internal and external housings are aligned and can have various cross section shapes, for example round, square and polygonal. Outer housing is coated with heat resistant material. Mind that outer and inner surfaces of internal housing accommodate at least three radial T-section ribs.

EFFECT: higher efficiency, increased savings, simpler design, mounting and operation.

1 cl, 2 dwg

Description

The invention relates to air heaters with convective heat exchangers for high-temperature flue gases of thermal power plants.

The closest technical solution to the claimed object is an air heater with a regenerative heat exchanger according to the patent of the Russian Federation No. 2011127, F24F 5/00, 1987 (prototype), namely, that fans are installed in the ducts for the supply and exhaust air, and the chamber with a regenerative heat exchanger placed perpendicular to these channels.

The disadvantage of the prototype is the relatively low efficiency due to the cross-organization of air flows.

The technical result is an increase in the efficiency of heat recovery of exhaust air, energy savings, simplification of design, installation and maintenance.

This is achieved by the fact that in the high-temperature coaxial air heater / heat exchanger containing the housings and channels for the passage of different-temperature air flows, there is additionally an inlet pipe for supplying high-temperature flue gases from the fluidized bed furnace and an outlet pipe for exhausting flue gases, moreover, coaxially to the body for flue gas passage a housing is located for the passage of flows of blast air from the blower fan through a pipe that is sent to the furnace, while the housing in The external covering and the internal covered are located relative to each other coaxially and can have a different cross-sectional shape, for example, round, rectangular, multifaceted, and the outer casing is lined with heat-insulating material from the outside, and at least three are mounted on the outer and inner surfaces of the inner casing radially spaced ribs having a T-shaped profile.

Figure 1 presents a General view of a high-temperature coaxial air heater-heat exchanger, figure 2 - its cross section.

The high-temperature coaxial air heater / heat exchanger comprises a housing 3, an inlet pipe 1 for supplying high-temperature flue gases from a fluidized bed furnace (not shown in the drawing) with a temperature of the order of 850 ÷ 950 ° C, and an outlet pipe 2 for exhausting flue gases to the hydraulic ash collector. Coaxially to the housing 3 for the passage of flue gases, the housing 6 is located for the passage of flows of blowing air from the blower through the pipe 4, which is sent to the furnace through the pipe 5 with a temperature of about 450 ÷ 550 ° C to stabilize the combustion process in a fluidized bed of inert bodies (not shown shown). These enclosures are external spanning 3 and inner spanning 6 located coaxially relative to each other and can have a different cross-sectional shape, for example, round, rectangular, polyhedral, and any second-order curve, for example an ellipse, etc. To prevent pollution by thermal emissions of the environment and to reduce heat loss during the disposal of flue gases, the casing 6 is lined with heat insulating material 7 from the outside. To increase the efficiency of heat transfer of flue gases passing through the channel 8 formed to at least three radially spaced ribs 9 having a T-shaped profile 10 are mounted on the outer surface of the housing 6 by the opposites 3 and 6, and to increase the efficiency of heat absorption of this heat by the flows of blast air coming from the blower fan into the furnace, also on at least three radially spaced ribs 11 having a T-shaped profile are mounted on the inner surface of the housing 6.

Ribs with a T-shaped profile, located on both the outer and inner surfaces of the covered heat exchanger body 6, can be made hollow of aluminum plates, and dispersed material with open cells and with a high heat absorption coefficient can be placed in the gap between the side surfaces of the ribs , for example expanded clay gravel (not shown in the drawing).

High-temperature coaxial air heater-heat exchanger operates as follows.

High-temperature flue gases from a fluidized bed furnace (not shown in the drawing) with a temperature of the order of 850 ÷ 950 ° C, flow through pipe 1 into housing 3 and pass through a channel 8 formed by buildings 3 and 6, and then through pipe 2, giving up its heat come for cleaning in a hydraulic ash trap (not shown in the drawing) with a temperature of the order of 450 ÷ 550 ° C. Coaxially with the flue gas flow inside the housing 6, the blast air flows from the blower through the pipe 4, which is sent to the furnace through the pipe 5 with a temperature of about 450 ÷ 550 ° C to stabilize the combustion process in a fluidized bed of inert bodies (not shown). Flows of flue gases and blast air can have both associated and counter directions.

To increase the heat transfer efficiency of the flue gases flowing through the channel 8 formed by the housings 3 and 6, at least three radially located fins 9 having a T-shaped profile 10 are mounted on the outer surface of the housing 6, and to increase the heat absorption efficiency of this heat at least three radially located fins 11 having a T-shaped profile are mounted on the inner surface of the housing 6 by the flows of blast air coming from the blast fan into the furnace.

Claims (2)

1. High-temperature coaxial air heater-heat exchanger, comprising housings and channels for passage of different temperature air flows, characterized in that it further comprises a housing, an inlet pipe for supplying high-temperature flue gases from the fluidized bed furnace and an outlet pipe for exhausting flue gases, and coaxially to the housing for the passage of flue gases is a housing for the passage of flows of blowing air from the blower fan through a pipe that is sent to the furnace, while the enclosures, the external enclosing and the internal being enclosed, are located relative to each other coaxially and can have a different cross-sectional shape, for example round, rectangular, multifaceted, and the outer casing is lined with heat-insulating material from the outside, and at least at least on the outer and inner surfaces of the inner casing , three radially spaced ribs having a T-shaped profile. 2. The high-temperature coaxial air heater-heat exchanger according to claim 1, characterized in that the fins with a T-shaped profile located both on the outer and inner surfaces of the covered heat exchanger body are made of hollow aluminum plates, and in the gap between the side surfaces of the fins dispersed material with open pores and with a high coefficient of heat absorption, for example expanded clay gravel, is placed.

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