Biomass circulating fluidized bed hot water boiler with steam generator

Abstract

The utility model discloses a biomass circulating fluidized bed hot water boiler with a steam generator. The biomass circulating fluidized bed hot water boiler can generate steam by itself. A water inlet and steam outlet header (18) is arranged at the top end of the first tail flue (7), a steam generator lower header (20) and an evaporation tube bundle (19) are arranged in the first tail flue (7) below the water inlet and steam outlet header (18), and a steam generator water supply port (25) and a steam output port (21) are respectively formed in the water inlet and steam outlet header (18). A steam generator water supply port (25) is communicated with a steam generator lower collecting box (20) through a steam generator water supply vertical pipe (26), an evaporation pipe bundle (19) is connected to the steam generator lower collecting box, the upper end of the evaporation pipe bundle is connected with a water inlet and steam outlet collecting box (18), and a steam blowing conveying pipeline (22) is connected to a steam output port (21).

Description

TECHNICAL FIELD

[0001] The utility model relates to a circulating fluidized bed hot water boiler, especially a biomass circulating fluidized bed hot water boiler with a steam generator. BACKGROUND

[0002] The biomass resource reserves of China are about 5 billion tons, and the biomass energy utilization rate accounted for 9.2% of the total in 2019. Biomass resources are widely used in the preparation of fuel, organic fertilizer, activated carbon, degradable packaging and other fields. The biomass hot water boiler directly uses biomass raw materials as fuel for combustion, and converts the energy generated by combustion into hot water. A large amount of alkali metal is produced during biomass fuel combustion, and the ash melting point is also very low, which causes serious slagging and ash deposition on the heating surface of the boiler, and even causes alkali corrosion of the heating surface, affecting the safe operation of the boiler. Therefore, the biomass boiler needs to be blown ash on its heating surface. If steam blowing is used to blow ash on the heating surface of the boiler, better ash blowing effect can be achieved. However, the conventional biomass hot water boiler does not have a steam source, so if steam blowing is used, external steam needs to be introduced into the boiler. Due to the limitation of the steam source, the promotion of the biomass hot water boiler is severely restricted. SUMMARY

[0003] The utility model provides a biomass circulating fluidized bed hot water boiler with a steam generator, which realizes self-production of steam for the biomass circulating fluidized bed hot water boiler, and blows ash on the heating surface of the boiler with the self-produced steam, thereby ensuring the safe operation of the boiler.

[0004] The utility model solves the above technical problems through the following technical solutions:

[0005] A biomass circulating fluidized bed hot water boiler with a steam generator, comprising a furnace, a boiler drum, a screw feeder, a cyclone separator, a tail first flue and a tail second flue, the tail first flue and the tail second flue are arranged in an N shape, a high-temperature economizer is arranged in the tail first flue, a low-temperature economizer and an air preheater are arranged in the tail second flue, a high-temperature economizer steam purging device is arranged on the high-temperature economizer, a low-temperature economizer steam purging device is arranged on the low-temperature economizer, a water inlet and steam outlet header is arranged at the top end of the tail first flue, a steam generator lower header and an evaporation tube bundle are arranged in the tail first flue below the water inlet and steam outlet header, a steam generator water inlet and a steam outlet are arranged on the water inlet and steam outlet header, the steam generator water inlet and the steam generator lower header are communicated together through a steam generator water feeding vertical pipe, the evaporation tube bundle is connected to the steam generator lower header, a steam purging conveying pipeline is connected to the steam outlet, and the steam purging conveying pipeline is communicated with the high-temperature economizer steam purging device and the low-temperature economizer steam purging device.

[0006] The low-temperature economizer is provided with a boiler feed water inlet, and the water outlet of the low-temperature economizer and the water inlet of the drum are communicated together through a water feeding pipeline; the furnace is provided with a membrane wall lower header, a membrane wall upper header and a membrane wall respectively, the drum is communicated with the membrane wall lower header through a downcomer, the membrane wall is arranged between the membrane wall lower header and the membrane wall upper header, and the membrane wall upper header is communicated with the drum through a top water guide pipe; a hot water conveying pipe is connected between the hot water outlet of the drum and the high-temperature economizer, and the high-temperature economizer is provided with a boiler hot water outlet.

[0007] The utility model especially suitable for the biomass circulating fluidized bed hot water boiler with steam generator in the central heating area, suitable for burning various biomass fuel, and the largest boiler capacity can reach 232MW; compared with the prior art, the utility model has the following advantages: (1) generating steam itself, using the steam blowing which has better blowing effect, prolonging the service life of the boiler; (2) can burn various biomass, such as tree trunk branch, crop straw, straw rice hull, poultry manure etc., and effectively solve the key problems of uneven feeding, poor fluidization, tail heating surface corrosion and blockage, and unstable circulation; (3) the boiler separator has high efficiency, good sealing property and high thermal efficiency; (4) the boiler is provided with tail two flue structure, which can reserve the space of SCR catalyst and effectively avoid the dust accumulation of SCR catalyst; (5) the boiler adopts high-efficiency separation return device, the circulating ash amount of the furnace is large, the original emission of NOx is low, and the desulfurization efficiency in the furnace is high. BRIEF DESCRIPTION OF DRAWINGS

[0008] Figure 1 It is the structural schematic diagram of the utility model;

[0009] Figure 2 It is the structural schematic diagram of the steam generator in the front direction of the utility model;

[0010] Figure 3 It is the structural schematic diagram of the steam generator in the side direction of the utility model. DETAILED DESCRIPTION

[0011] The utility model will be described in detail in combination with the drawings:

[0012] The utility model provides a kind of biomass circulating fluidized bed hot water boiler with steam generator, including hearth 1, drum 2, screw feeder 4, cyclone 5, tail first flue 7 and tail second flue 8, screw feeder 4 is connected on the fuel feeding port of drum 2, biomass fuel is sent into hearth 1 by screw feeder 4, hearth 1 is communicated together with cyclone 5 by connecting flue on upper end, cyclone 5 is communicated together with hearth 1 by return pipe;Tail first flue 7 and tail second flue 8 are arranged in N shape, high-temperature economizer 14 is provided in tail first flue 7, low-temperature economizer 16 and air preheater 26 are respectively provided in tail second flue 8, high-temperature economizer steam purger 23 is provided on high-temperature economizer 14, low-temperature economizer steam purger 24 is provided on low-temperature economizer 16, the heating surface of high-temperature and low-temperature economizer is purged by steam purger to prevent slagging and ash deposition;Steam generator is provided in tail first flue 7, the water transported into steam generator is converted into steam by high-temperature flue gas in tail first flue 7, for purging the heating surface of high-temperature and low-temperature economizer, so that hot water boiler has the function of self-production of steam, water inlet and steam outlet header 18 is provided at the top of tail first flue 7, steam generator lower header 20 and evaporation tube bundle 19 are provided in tail first flue 7 below water inlet and steam outlet header 18, steam generator feedwater inlet 25 and steam outlet 21 are respectively provided on water inlet and steam outlet header 18, steam generator feedwater inlet 25 is communicated together with steam generator lower header 20 by steam generator water supply vertical pipe 26, evaporation tube bundle 19 is connected on steam generator lower header 20, the upper end of evaporation tube bundle 19 is connected together with water inlet and steam outlet header 18, separate water supply system sends the water converted into steam into water inlet and steam outlet header 18, and is sent into steam generator lower header 20 by steam generator water supply vertical pipe 26, then, the water in steam generator lower header 20 is heated and converted into steam and water mixture by high-temperature flue gas in tail first flue 7, enters into water inlet and steam outlet header 18, finally, after the separation of steam and water, the obtained steam is output from steam outlet 21, steam purging delivery line 22 is connected on steam outlet 21, steam purging delivery line 22 is communicated together with high-temperature economizer steam purger 23 and low-temperature economizer steam purger 24 respectively;Steam purger can periodically remove the ash attached to the heating surface, to ensure long-term safe and efficient operation of boiler.

[0013] The low-temperature economizer 16 is provided with a boiler feed water inlet 17, the cold water feed inlet of the hot water boiler is arranged on the low-temperature economizer 16, and the water outlet of the low-temperature economizer 16 and the water inlet of the drum 2 are communicated together through a water feeding pipeline 27; the membrane wall lower header 9, the membrane wall upper header 11 and the membrane wall 10 are arranged in the furnace 1 respectively, the drum 2 is communicated with the membrane wall lower header 9 through the downcomer 3, the membrane wall 10 is arranged between the membrane wall lower header 9 and the membrane wall upper header 11, the membrane wall upper header 11 is communicated with the drum 2 through the top water guide pipe 12, the hot water outlet 13 of the drum 2 is connected with the high-temperature economizer 14 through the hot water conveying pipe 6, and the boiler hot water outlet 15 is arranged on the high-temperature economizer 14.

[0014] The water feeding of the boiler enters into the low-temperature economizer 16 through the boiler feed water inlet 17 arranged on the low-temperature economizer 16, is heated by the flue gas in the tail second flue 8, and then enters into the drum 2 through the water feeding pipeline 27 after being preliminarily heated, reaches the membrane wall lower header 9 through the downcomer 3, is collected to the membrane wall upper header 11 after being heated upwards through the membrane wall 10, enters into the drum 2 through the top water guide pipe 12, and is conveyed to the high-temperature economizer 14 through the hot water outlet 13 of the drum 2 and the hot water conveying pipe 6, and then is further heated by the high-temperature flue gas in the tail first flue 7, and is output through the boiler hot water outlet 15.

Claims

1. A biomass circulating fluidized bed hot water boiler with a steam generator, comprising a furnace (1), a drum (2), a screw feeder (4), a cyclone separator (5), a tail first flue (7) and a tail second flue (8), the tail first flue (7) and the tail second flue (8) are arranged in an N shape, a high-temperature economizer (14) is arranged in the tail first flue (7), a low-temperature economizer (16) and an air preheater (26) are arranged in the tail second flue (8) respectively, characterized in that, The high-temperature economizer (14) is provided with a high-temperature economizer steam purger (23), the low-temperature economizer (16) is provided with a low-temperature economizer steam purger (24), the top end of the tail first flue (7) is provided with a water inlet and steam outlet header (18), the steam generator lower header (20) and the evaporation tube bundle (19) are arranged in the tail first flue (7) below the water inlet and steam outlet header (18), the steam generator water inlet (25) and the steam outlet (21) are arranged on the water inlet and steam outlet header (18) respectively, the steam generator water inlet (25) is communicated with the steam generator lower header (20) through the steam generator water feeding vertical pipe, the evaporation tube bundle (19) is connected to the steam generator lower header (20), the upper end of the evaporation tube bundle (19) is connected to the water inlet and steam outlet header (18), the steam purging conveying pipeline (22) is connected to the steam outlet (21), and the steam purging conveying pipeline (22) is communicated with the high-temperature economizer steam purger (23) and the low-temperature economizer steam purger (24) respectively.

2. The biomass circulating fluidized bed hot water boiler with a steam generator according to claim 1, characterized in that, The low-temperature economizer (16) is provided with a boiler water inlet (17), and the water outlet of the low-temperature economizer (16) is communicated with the water inlet of the drum (2) through the water feeding pipeline (27); the membrane wall lower header (9), the membrane wall upper header (11) and the membrane wall (10) are arranged in the furnace (1) respectively, the drum (2) is communicated with the membrane wall lower header (9) through the downcomer (3), the membrane wall (10) is arranged between the membrane wall lower header (9) and the membrane wall upper header (11), the membrane wall upper header (11) is communicated with the drum (2) through the top water guide pipe (12), the hot water conveying pipe (6) is connected between the hot water outlet (13) of the drum (2) and the high-temperature economizer (14), and the boiler hot water outlet (15) is arranged on the high-temperature economizer (14).

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