Small-capacity ultra-high-temperature and ultra-high-pressure one-time reheating gas boiler

Abstract

The utility model discloses a small-capacity ultra-high-temperature and ultra-high-pressure one-time reheating gas boiler which comprises a burner, a steam pocket, a hearth, a horizontal flue, a steering chamber and a tail flue which are communicated in sequence. A platen superheater, a high-temperature superheater, a high-temperature reheater and a low-temperature superheater are sequentially arranged in the hearth and the horizontal flue in the flowing direction of smoke, and the low-temperature reheater, an upper-stage economizer, a lower-stage economizer and an air preheater are sequentially arranged in the tail flue behind the steering chamber from top to bottom. According to the utility model, main steam and reheated steam with higher parameters are produced through the structural arrangement of the heating surface and the optimization of the steam-water flow, the superheated steam pressure at the outlet of the high-temperature superheater can reach 14 MPa (g), the temperature can reach 571 DEG C, and the temperature at the outlet of the reheater can reach 571 DEG C, so that the generating capacity of the unit is larger, and the generating efficiency is higher.

Description

Technical Field

[0001] The utility model relates to the technical fields of secondary energy recovery and boilers in iron and steel metallurgy, and in particular to a small-capacity ultra-high temperature and ultra-high pressure single-stage reheating coal gas boiler. Background Art

[0002] Steel companies generate large quantities of gas byproducts during their production processes, including blast furnace gas, converter gas, and coke oven gas. Utilizing secondary energy and efficiently recycling excess gas for power generation is crucial for improving corporate competitiveness amidst the current intensifying competition in the steel industry. Internationally, there are two primary types of gas-fired power generation: traditional single-cycle steam boiler generators and combined cycle gas-steam power generation (CCPP).

[0003] Method 1: The steam single-cycle boiler generator set has good adaptability to gas and can burn 100% of various gases. It has few restrictions on gas quality and flow ratio, a large load adjustment range, and a fast load change rate. It is the best buffer user and guarantee means for "zero gas emission" scheduling. The system is simple, easy to operate and maintain, with high reliability and availability, small footprint, short construction period, low investment, low maintenance cost, and fast economic benefits.

[0004] Mode 2: The main equipment and components of gas-steam combined cycle power generation basically need to be imported, with high one-time investment, high and expensive operation and maintenance requirements, very strict requirements on the quality and stability of coal gas, and a significant drop in efficiency at low load.

[0005] Currently, domestic steel companies primarily utilize method 1 for gas-fired power generation. Large steel companies have largely adopted high-parameter gas-fired generator sets. However, due to limited surplus gas and smaller boiler capacity, small and medium-sized steel companies use relatively low steam parameters for gas-fired power generation, mostly below high temperature and high pressure. While high-temperature and high-pressure gas-fired generator sets are technically mature, their overall plant thermal efficiency is relatively low, at approximately 31%. Ultra-high-pressure reheat gas-fired boiler generator sets have an overall plant thermal efficiency of approximately 38%, approximately 20% higher than high-temperature and high-pressure units. Developing high-parameter units can improve energy efficiency, enhance corporate competitiveness, and support the government's call for energy conservation and emission reduction. Utility Model Content

[0006] To address these technical issues, this utility model designs a small-capacity, ultra-high-temperature, ultra-high-pressure, single-stage reheat gas boiler. By optimizing the heating surface structure and steam-water flow, it produces higher-performance main steam and reheat steam, improving the unit's power generation efficiency and output.

[0007] The utility model adopts the following technical solutions:

[0008] A small-capacity ultra-high-temperature and ultra-high-pressure single-stage reheating coal gas boiler comprises a burner, a steam drum, a furnace, a horizontal flue, a turning chamber and a tail flue, wherein the furnace, the horizontal flue, the turning chamber and the tail flue are connected in sequence, and a platen superheater, a high-temperature superheater, a high-temperature reheater and a low-temperature superheater are arranged in sequence in the furnace and the horizontal flue along the flow direction of the flue gas, and a low-temperature reheater, an upper economizer, a lower economizer and an air preheater are arranged in sequence from top to bottom in the tail flue behind the turning chamber.

[0009] Preferably, the burners are arranged in layers on the front wall of the lower part of the furnace, and can be arranged in 1 to 4 layers, with 2 to 3 burners arranged on each layer.

[0010] Preferably, a water-cooled wall is arranged in the upper part of the furnace, and a secondary air inlet is provided above the burner in the lower part of the water-cooled wall in the furnace.

[0011] Preferably, a combustion guard zone is provided in the burner area at the lower part of the water-cooled wall in the furnace.

[0012] Preferably, the low-temperature superheater and the low-temperature reheater adopt a spiral fin tube structure.

[0013] Preferably, the air preheater is a tubular air preheater.

[0014] Preferably, the tubular air preheater adopts a vertical tube box structure, a horizontal tube box structure, a heat pipe structure or a rotary structure.

[0015] Preferably, the air preheater can be arranged in two stages.

[0016] Preferably, the outlet superheated steam pressure of the high-temperature superheater is 13-14 MPa(g) and the temperature is 565-571°C.

[0017] Preferably, the outlet steam pressure of the high-temperature reheater is 1.8~3.5MPa(g) and the temperature is 565~571°C.

[0018] The beneficial effects of the present invention are as follows: the present invention produces main steam and reheated steam with higher parameters through the arrangement of the heating surface structure and the optimization of the steam-water flow. The superheated steam pressure at the high-temperature superheater outlet can reach 14 MPa (g), the temperature can reach 571°C, and the reheater outlet temperature can reach 571°C. Therefore, the unit has a larger power generation capacity and a higher power generation efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a structural schematic diagram of the utility model;

[0020] In the figure: 1. Burner, 2. Secondary air inlet, 3. Guard belt, 4. Furnace, 5. Platen superheater, 6. Horizontal flue, 7. Steam drum, 8. High-temperature superheater, 9. High-temperature reheater, 10. Low-temperature superheater, 11. Turning chamber, 12. Tail flue, 13. Low-temperature reheater, 14. Upper economizer, 15. Lower economizer, 16. Air preheater. DETAILED DESCRIPTION

[0021] The technical solution of the present invention is further described in detail below through specific embodiments and in conjunction with the accompanying drawings:

[0022] Example: Figure 1 As shown, a small-capacity ultra-high temperature and ultra-high pressure single-reheat gas boiler includes a burner 1, a steam drum 7, a furnace 4, a horizontal flue 6, a turning chamber 11 and a tail flue 12.

[0023] Along the flow direction of the flue gas, the screen superheater 5, high-temperature superheater 8, high-temperature reheater 9 and low-temperature superheater 10 are arranged in sequence in the furnace and the horizontal flue. In the tail flue behind the turning chamber, the low-temperature reheater 13, upper economizer 14, lower economizer 15 and air preheater 16 are arranged in sequence from top to bottom.

[0024] The utility model produces main steam and reheated steam with higher parameters through the structural arrangement of the heating surface and the optimization of the steam-water flow, thereby improving the power generation efficiency and power generation of the unit.

[0025] The burners are arranged in layers on the front wall of the lower part of the furnace. Depending on the situation, 1 to 4 layers can be arranged, with 2 to 3 burners on each layer.

[0026] In order to reduce NOx emissions, secondary air inlets 2 are provided at the lower part of the water-cooled wall and the upper part of the burner.

[0027] In order to improve the combustion efficiency of low calorific value gas, a fire-prevention zone 3 is provided in the burner area at the lower part of the water-cooled wall.

[0028] In order to improve heat transfer efficiency and reduce boiler steel consumption, the low-temperature superheater and low-temperature reheater can adopt a spiral fin tube structure.

[0029] Tubular air preheaters can adopt vertical tube box structure, horizontal tube box structure, heat pipe type or rotary structure.

[0030] In order to reduce the flue gas temperature at the boiler outlet and improve boiler efficiency, the air preheater can adopt a two-stage arrangement.

[0031] The superheated steam pressure at the high-temperature superheater outlet is 13-14 MPa(g), and the temperature is 565-571°C. The steam pressure at the high-temperature reheater outlet is 1.8-3.5 MPa(g), and the temperature is 565-571°C.

[0032] The utility model produces main steam and reheated steam with higher parameters through the structural arrangement of the heating surface and the optimization of the steam-water flow. The superheated steam pressure at the high-temperature superheater outlet can reach 14MPa(g), the temperature can reach 571℃, and the reheater outlet temperature can reach 571℃. Therefore, the unit has a larger power generation capacity and higher power generation efficiency.

[0033] The embodiment described above is only a preferred solution of the present invention and does not limit the present invention in any form. Other variations and modifications are possible without exceeding the technical solutions described in the claims.

Claims

1. A small-capacity ultra-high temperature and ultra-high pressure single-stage reheat gas boiler, comprising a burner (1), a steam drum (7), a furnace (4), a horizontal flue (6), a turning chamber (11) and a tail flue (12), wherein the furnace (4), the horizontal flue (6), the turning chamber (11) and the tail flue (12) are connected in sequence, and is characterized in that: A screen superheater (5), a high-temperature superheater (8), a high-temperature reheater (9) and a low-temperature superheater (10) are arranged in sequence in the furnace (4) and the horizontal flue (6) along the flow direction of the flue gas, and a low-temperature reheater (13), an upper economizer (14), a lower economizer (15) and an air preheater (16) are arranged in sequence from top to bottom in the tail flue (12) after the turning chamber (11).

2. A small-capacity ultra-high temperature and ultra-high pressure single-reheat gas boiler according to claim 1, characterized in that: The burners (1) are arranged in layers on the front wall of the lower part of the furnace (4), and can be arranged in 1 to 4 layers, with 2 to 3 burners (1) arranged on each layer.

3. The small-capacity ultra-high temperature and ultra-high pressure single-reheat gas boiler according to claim 1, characterized in that: A water-cooled wall is arranged in the upper part of the furnace (4), and a secondary air inlet (2) is provided above the burner in the lower part of the water-cooled wall in the furnace (4).

4. A small-capacity ultra-high temperature and ultra-high pressure single-reheat gas boiler according to claim 3, characterized in that: A combustion protection zone (3) is provided in the burner area at the lower part of the water-cooled wall in the furnace (4).

5. The small-capacity ultra-high temperature and ultra-high pressure single-reheat gas boiler according to claim 1, characterized in that: The low-temperature superheater (10) and the low-temperature reheater (13) adopt a spiral fin tube structure.

6. The small-capacity ultra-high temperature and ultra-high pressure single-reheat gas boiler according to claim 1, characterized in that: The air preheater (16) is a tubular air preheater.

7. A small-capacity ultra-high temperature and ultra-high pressure single-reheat gas boiler according to claim 6, characterized in that: The tubular air preheater adopts a vertical tube box structure, a horizontal tube box structure, a heat pipe structure or a rotary structure.

8. The small-capacity ultra-high temperature and ultra-high pressure single-reheat gas boiler according to claim 1, characterized in that: The air preheater (16) may be arranged in two stages.

9. The small-capacity ultra-high temperature and ultra-high pressure single-reheat gas boiler according to claim 1, characterized in that: The outlet superheated steam pressure of the high-temperature superheater (8) is 13-14 MPa(g) and the temperature is 565-571°C.

10. The small-capacity ultra-high temperature and ultra-high pressure single-reheat gas boiler according to claim 1, characterized in that: The outlet steam pressure of the high-temperature reheater (9) is 1.8~3.5MPa(g) and the temperature is 565~571°C.

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