Novel circulating fluidized bed pressure phase change boiler

Abstract

The invention relates to the technical field of boilers, in particular to a novel circulating fluidized bed pressure phase change boiler which comprises an air supply combustion unit, a separation and material returning unit, a phase change heat exchange unit, a flue gas waste heat collecting unit and a maintenance unit, the air supply combustion unit is communicated with the separation and material returning unit, the separation and material returning unit is communicated with the flue gas waste heat collecting unit, and the maintenance unit is communicated with the phase change heat exchange unit. A water cooling wall of the air supply combustion unit is a heat exchange fluid pipeline of the phase change heat exchange unit, and the maintenance unit is connected with a heat preservation wall outside the phase change boiler. According to the novel circulating fluidized bed pressure phase-change boiler with the structure, efficient and stable steam production is achieved, steam in the heat exchange fluid pipeline of the phase-change boiler is condensed into condensate water through the condensation heat exchanger, then the condensate water returns to the heat exchange fluid pipeline, water does not need to be supplemented in the boiler, a heated surface does not scale, and energy is saved. Pollution discharge is not needed in the normal use process, and the problems of unstable operation and low efficiency caused by water quality influence are solved.

Description

Technical Field

[0001] The invention relates to the technical field of boilers, in particular to a novel circulating fluidized bed pressure phase change boiler. Background Art

[0002] A boiler is an energy converter that uses the heat released by fuel combustion or other heat energy to heat working water or other fluids to certain parameters. The main working principle of a boiler is that it is a thermal device that uses the heat released by fuel combustion or the waste heat in industrial production to transfer the water in the container to the required temperature or a certain pressure of steam.

[0003] The boiler operates in both the "pot" and the "furnace" parts. After the water enters the boiler, the boiler heating surface in the steam-water system transfers the absorbed heat to the water, heating the water into hot water of a certain temperature and pressure or generating steam, which is then drawn out for use. In the combustion equipment part, the fuel combustion continuously releases heat, and the high-temperature flue gas generated by the combustion transfers heat to the boiler heating surface through heat transfer, while its own temperature gradually decreases and is finally discharged from the chimney. Due to the limitation of the vacuum degree, the existing vacuum hot water boiler has a low outlet water temperature, and needs to maintain negative pressure operation, which requires high operating conditions. Summary of the invention

[0004] The purpose of the present invention is to provide a new circulating fluidized bed pressure phase change boiler, which has a higher outlet water temperature than a vacuum phase change boiler and has no problem of unstable operation and reduced efficiency caused by water quality.

[0005] To achieve the above-mentioned objectives, the present invention provides a novel circulating fluidized bed pressure phase change boiler, comprising an air supply and combustion unit, a separation and return material unit, a phase change heat exchange unit, a flue gas waste heat collection unit and an inspection unit. The air supply and combustion unit is connected to the separation and return material unit, the separation and return material unit is connected to the flue gas waste heat collection unit, the water-cooled wall of the air supply and combustion unit is the heat exchange fluid pipeline of the phase change heat exchange unit, and the inspection unit is connected to the insulation wall outside the phase change boiler.

[0006] Preferably, a feeding mechanism is provided at the lower part of the furnace of the air supply combustion unit, and the feeder of the feeding mechanism is connected to the combustion chamber of the furnace through a feeding channel. The bottom of the combustion chamber is a primary air mechanism, the top of the combustion chamber is a secondary air mechanism, and a tertiary air mechanism is provided above the secondary air mechanism.

[0007] Preferably, the upper part of the furnace is communicated with the upper part of the cyclone separator of the separation and return material unit, the bottom of the cyclone separator is communicated with the return material valve, and the return material valve is communicated with the combustion chamber through the return material pipeline.

[0008] Preferably, the condensing heat exchanger of the phase change heat exchange unit is located at the top of the furnace, and the water inlet and outlet of the condensing heat exchanger are respectively connected to the steam outlet and the reflux outlet of the heat exchange fluid pipeline in the furnace.

[0009] Preferably, the high-temperature smoke tube of the flue gas waste heat collection unit is connected to the low-temperature smoke tube, and the top of the cyclone separator is connected to the top of the high-temperature smoke tube.

[0010] Preferably, the primary air chamber of the primary air mechanism is located below the combustion chamber, and the primary air chamber is connected to the combustion chamber through an air distribution plate, and a plurality of air hoods are evenly arranged on the air distribution plate.

[0011] Preferably, the tertiary air mechanism has the same structure as the secondary air mechanism, and the wind box of the secondary air mechanism is arranged on the outer wall of the furnace in a surrounding manner. The wind box is connected to the furnace through an air inlet pipe, and the air inlet pipe is provided with an air inlet nozzle in the furnace.

[0012] Preferably, the air inlet channel at the bottom of the return valve is connected to the return cavity, the side wall of the return cavity is provided with an inspection hole and a peep hole, and the return cavity is connected to the return pipe through an expansion joint.

[0013] Preferably, the high-temperature smoke tube and the low-temperature smoke tube are both composed of a plurality of threaded smoke tubes.

[0014] Preferably, the insulation wall of the furnace includes insulation wall one and insulation wall two, insulation wall one is a silicate board, and insulation wall two at the cyclone separator and flue collection unit are composed of a concrete refractory layer, a silicate board and a steel plate outer shell from the inside to the outside, and maintenance platforms are arranged at intervals on insulation wall one and insulation wall two, and platform escalators are provided between adjacent maintenance platforms.

[0015] Therefore, the present invention adopts a new type of circulating fluidized bed pressure phase change boiler with the above structure. By controlling the pressure in the boiler, the boiling point of water can be adjusted. By controlling the pressure and temperature of the water, efficient and stable steam production can be achieved. There is no need to make up water in the boiler drum, the heating surface will not scale, and there is no need to discharge sewage during normal use. There is no problem of unstable operation and reduced efficiency caused by water quality.

[0016] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of a novel circulating fluidized bed pressure phase change boiler of the present invention; Figure 2 It is a partial schematic diagram of a novel circulating fluidized bed pressure phase change boiler of the present invention.

[0018] Reference numerals: 1. Air supply combustion unit; 11. Furnace; 12. Combustion chamber; 13. Primary air mechanism; 131. Air distribution plate; 132. Air hood; 14. Secondary air mechanism; 141. Bellows; 142. Air inlet nozzle; 15. Tertiary air mechanism; 2. Separation and return unit; 21. Cyclone separator; 22. Return valve; 23. Expansion joint; 3. Phase change heat exchange unit; 31. Condensing heat exchanger; 32. Heat exchange fluid pipeline; 4. Flue gas waste heat collection unit; 41. High-temperature smoke pipe; 42. Low-temperature smoke pipe; 5. Maintenance unit; 51. Maintenance platform; 52. Platform escalator. DETAILED DESCRIPTION

[0019] The present invention is further described below in conjunction with the accompanying drawings and embodiments. Unless otherwise defined, the technical terms or scientific terms used in the present invention should be the common meanings understood by people with ordinary skills in the field to which the present invention belongs. The above-mentioned features or features mentioned in the specific examples mentioned in the present invention can be combined arbitrarily, and these specific embodiments are only used to illustrate the present invention and are not used to limit the scope of the present invention.

[0020] Example like Figure 1 and Figure 2 As shown, the present invention provides a novel circulating fluidized bed pressure phase change boiler, comprising an air supply combustion unit 1, a separation and return material unit 2, a phase change heat exchange unit 3, a flue gas waste heat collection unit 4 and a maintenance unit 5. The air supply combustion unit 1 is connected to the separation and return material unit 2, and the separation and return material unit 2 is connected to the flue gas waste heat collection unit 4. The water-cooled wall of the air supply combustion unit 1 is the heat exchange fluid pipeline 32 of the phase change heat exchange unit 3, and the maintenance unit 5 is connected to the insulation wall outside the phase change boiler.

[0021] This boiler does not need to be equipped with water treatment equipment and deoxygenation equipment during operation, but the water quality should meet the requirements of the current standard GB / T1576 "Industrial Boiler Water Quality". The air supply combustion unit 1 burns the fuel and supplies air in stages during the combustion process to improve the combustion efficiency of the fuel in the furnace 11. The separation and return unit 2 separates the ash particles and gas in the ash-containing flue gas, and the ash particles return to the air supply combustion unit 1 to continue burning, and the flue gas enters the flue gas waste heat collection unit 4 for waste heat recovery. The setting of the maintenance unit 5 facilitates the maintenance and replacement of each unit.

[0022] A feeding mechanism is provided at the lower part of the furnace 11 of the air supply combustion unit 1, and the feeder of the feeding mechanism is connected to the combustion chamber 12 of the furnace 11 through a feeding channel. The bottom of the combustion chamber 12 is a primary air mechanism 13, the top of the combustion chamber 12 is a secondary air mechanism 14, and a tertiary air mechanism 15 is provided above the secondary air mechanism 14.

[0023] The excess air coefficient in the furnace 11 is 1.2. The fuel burns in the combustion chamber 12 of the furnace 11. The primary air mechanism 13 enters the combustion chamber 12 to participate in the fuel combustion and transport the fuel. Charcoal, firewood, cow dung and corn cobs can be used as ignition fuel when igniting the fuel. The secondary air mechanism 14 sends secondary air into the furnace 11 to supplement the oxygen required in the combustion process to ensure complete combustion of the fuel. The secondary air accounts for 60% of the total air volume. The tertiary air mechanism 15 sends tertiary air into the furnace 11 to further supplement oxygen to ensure complete combustion of the fuel. By adjusting the air volume and distribution of the tertiary air, the combustion temperature in the furnace 11 can be controlled to avoid local overheating or incomplete combustion.

[0024] The upper part of the furnace 11 is connected to the upper part of the cyclone separator 21 of the separation and return unit 2, and the bottom of the cyclone separator 21 is connected to the return valve 22, and the return valve 22 is connected to the combustion chamber 12 through the return pipe. The cyclone separator 21 can efficiently separate solid particles in the flue gas, and by separating the incompletely burned fuel particles, return them to the combustion chamber 12 for re-combustion, thereby improving the utilization rate of the fuel and thus improving the overall thermal efficiency of the boiler. The separated flue gas is discharged from the top, continues to enter the flue gas waste heat collection unit 4 for waste heat collection, and then discharged into the atmosphere.

[0025] The condensing heat exchanger 31 of the phase change heat exchange unit 3 is located at the top of the furnace 11, and the water inlet and outlet of the condensing heat exchanger 31 are respectively connected to the steam outlet and the reflux outlet of the heat exchange fluid pipeline 32 in the furnace 11. After heat exchange with the heat exchange fluid pipeline, the condensing heat exchanger 31 condenses the water vapor obtained in the heat exchange fluid pipeline into liquid water, releases latent heat, and recovers latent heat to improve the overall thermal efficiency of the boiler, reduce fuel consumption, and reduce operating costs. A fire-prevention belt is laid between the heat exchange fluid pipeline 32 and the upper part of the combustion chamber 12.

[0026] The high-temperature smoke tube 41 of the flue gas waste heat collection unit 4 is connected to the low-temperature smoke tube 42, and the top of the cyclone separator 21 is connected to the top of the high-temperature smoke tube 41. The high-temperature smoke tube 41 and the low-temperature smoke tube 41 are both composed of a number of threaded smoke tubes. The high-temperature smoke leaving the cyclone separator 21 enters the low-temperature smoke tube 42 through the high-temperature smoke tube 41. The inner and outer walls of the threaded smoke tube are designed with spiral protrusions, which increase the contact area between the smoke and the heat exchange medium and have a self-cleaning effect. The threaded structure allows the smoke to form turbulence when flowing in the threaded smoke tube, enhancing the heat transfer effect and improving the heat transfer efficiency.

[0027] The primary air chamber of the primary air mechanism 13 is located below the combustion chamber, and the primary air chamber is connected to the combustion chamber through the air distribution plate 131, and a number of air caps 132 are evenly arranged on the air distribution plate 131. The material of the air caps 132 is high temperature resistant and wear-resistant cast steel, and the ventilation cross-sectional ratio of the air distribution plate 131 is 0.02. The primary air fan of the primary air mechanism 13 has a rotation speed of 2800-3000r / min, and the primary air generated by the primary air fan enters the combustion chamber 12 through the air caps 132.

[0028] The tertiary air mechanism 15 has the same structure as the secondary air mechanism 14. The wind box 141 of the secondary air mechanism 14 is disposed around the outer wall of the furnace 11. The wind box 141 is connected to the furnace 11 through an air inlet pipe, and the air inlet pipe is provided with an air inlet nozzle 142 in the furnace 11.

[0029] The speed of the secondary fan in the secondary air mechanism 14 is 1400-1500r / min, and the secondary air generated by the secondary fan enters the wind box 141, and then enters the furnace 11 through a plurality of air inlet nozzles 142. The arrangement of the air inlet nozzles 142 facilitates the control of the combustion degree and furnace temperature of the fuel in the furnace 11. The portion of the air inlet pipe close to the furnace 11 is arranged at an angle to increase the turbulence of the secondary air, promote the mixing of the fuel and the secondary air, and improve the combustion efficiency.

[0030] The air inlet channel at the bottom of the return valve 22 is connected to the return cavity, and the side wall of the return cavity is provided with an inspection hole and a peep hole. The return cavity is connected to the return pipe through the expansion joint 23. After the soot particles enter the return valve 22, the air inlet channel blows up the soot particles entering the return valve 22 and sends them into the return cavity. The provision of the inspection hole facilitates maintenance of the interior of the return valve 22.

[0031] The peephole is provided to facilitate the inspection of the inside of the return valve 22, and the internal state of the return valve 22 can be observed through the peephole. The expansion joint 23 is a non-metallic flexible expansion structure that can absorb the axial and radial expansion of the system due to thermal expansion and contraction, and protect the pipeline from damage.

[0032] The insulation wall of the furnace 11 includes insulation wall 1 and insulation wall 2. Insulation wall 1 is a silicate board. Insulation wall 2 at the cyclone separator 21 and the flue collection unit is a concrete refractory layer, a silicate board and a steel plate shell from the inside to the outside. Maintenance platforms 51 are arranged on insulation wall 1 and insulation wall 2 at intervals, and platform escalators 52 are arranged between adjacent maintenance platforms 51. The setting of insulation wall 1 and insulation wall 2 reduces heat loss, improves the thermal efficiency of the boiler, and reduces fuel consumption. The setting of maintenance platform 51 is convenient for maintenance of each unit, and platform escalators 52 are convenient for moving to each maintenance platform 51.

[0033] Therefore, the present invention adopts a new type of circulating fluidized bed pressure phase change boiler with the above structure. By controlling the pressure in the boiler, the boiling point of water can be adjusted. By controlling the pressure and temperature of the water, efficient and stable steam production can be achieved. There is no need to make up water in the boiler drum, the heating surface will not scale, and there is no need to discharge sewage during normal use. There is no problem of unstable operation and reduced efficiency caused by water quality.

[0034] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that they can still modify or replace the technical solution of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solution to deviate from the spirit and scope of the technical solution of the present invention.

Claims

1. A new circulating fluidized bed pressure phase change boiler, characterized in that: It includes an air supply combustion unit, a separation and return material unit, a phase change heat exchange unit, a flue gas waste heat collection unit and a maintenance unit. The air supply combustion unit is connected to the separation and return material unit, the separation and return material unit is connected to the flue gas waste heat collection unit, the water-cooled wall of the air supply combustion unit is the heat exchange fluid pipeline of the phase change heat exchange unit, and the maintenance unit is connected to the insulation wall outside the phase change boiler.

2. A novel circulating fluidized bed pressure phase change boiler according to claim 1, characterized in that: A feeding mechanism is provided at the lower part of the furnace of the air supply combustion unit. The feeder of the feeding mechanism is connected with the combustion chamber of the furnace through a feeding channel. The bottom of the combustion chamber is a primary air mechanism, the top of the combustion chamber is a secondary air mechanism, and a tertiary air mechanism is provided above the secondary air mechanism.

3. The novel circulating fluidized bed pressure phase change boiler according to claim 1 is characterized in that: The upper part of the furnace is communicated with the upper part of the cyclone separator of the separation and return material unit, the bottom of the cyclone separator is communicated with the return material valve, and the return material valve is communicated with the combustion chamber through the return material pipeline.

4. The novel circulating fluidized bed pressure phase change boiler according to claim 1 is characterized in that: The condensing heat exchanger of the phase change heat exchange unit is located at the top of the furnace, and the water inlet and outlet of the condensing heat exchanger are respectively connected to the steam outlet and the reflux outlet of the heat exchange fluid pipeline in the furnace.

5. The novel circulating fluidized bed pressure phase change boiler according to claim 1 is characterized in that: The high-temperature smoke tube of the flue gas waste heat collection unit is connected to the low-temperature smoke tube, and the top of the cyclone separator is connected to the top of the high-temperature smoke tube.

6. The novel circulating fluidized bed pressure phase change boiler according to claim 1 is characterized in that: The primary air chamber of the primary air mechanism is located below the combustion chamber, and the primary air chamber is connected with the combustion chamber through an air distribution plate, and a plurality of air caps are evenly arranged on the air distribution plate.

7. The novel circulating fluidized bed pressure phase change boiler according to claim 1 is characterized in that: The tertiary air mechanism has the same structure as the secondary air mechanism. The wind box of the secondary air mechanism is arranged on the outer wall of the furnace. The wind box is connected with the furnace through an air inlet pipe. The air inlet pipe is provided with an air inlet nozzle in the furnace.

8. The novel circulating fluidized bed pressure phase change boiler according to claim 1 is characterized in that: The air inlet channel at the bottom of the return valve is connected with the return cavity, and the side wall of the return cavity is provided with an inspection hole and a peep hole. The return cavity is connected with the return pipeline through an expansion joint.

9. The novel circulating fluidized bed pressure phase change boiler according to claim 5 is characterized by: Both the high-temperature smoke tube and the low-temperature smoke tube are composed of a number of threaded smoke tubes.

10. The novel circulating fluidized bed pressure phase change boiler according to claim 1 is characterized in that: The insulation wall of the furnace includes insulation wall one and insulation wall two. Insulation wall one is a silicate board. Insulation wall two at the cyclone separator and flue collection unit are composed of a concrete refractory layer, a silicate board and a steel plate outer shell from the inside to the outside. Maintenance platforms are arranged at intervals on insulation wall one and insulation wall two, and platform escalators are provided between adjacent maintenance platforms.

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