CN209801442U - Chamber-fired water-fire tube set series low nitrogen high thermal efficiency boiler - Google Patents

Abstract

The utility model relates to a series-connected low-nitrogen high-heat-efficiency boiler with a chamber-fired water-fire tube set. The boiler adopts the central arrangement of the combustion furnace, and in the outer heat medium water flow chamber, the heat exchange pipe is arranged inside, and the heat medium water flow chamber is arranged with two return smoke guide pipes and three return thread smoke pipes. Through this structure, the radiation heat exchange surface of the furnace can be greatly increased, and the flow rate of the heat medium water can be increased; and a heat exchange method in which flue gas and heat medium water are countercurrent is formed; this structure can exchange heat in time to reduce the furnace temperature. At the same time, the secondary combustion method of the secondary cyclone component can not only ensure the temperature requirements in the entire combustion furnace when the initial ignition temperature is low, but also reduce the generation of a large amount of nitrogen oxides and carbon dioxide caused by the excessively high initial combustion furnace The problem.

Description

Chamber-fired water-fire tube set series low nitrogen high thermal efficiency boiler

technical field

The utility model relates to a steam boiler, in particular to a chamber-fired water-fire tube suit series-connected low-nitrogen high-heat-efficiency boiler.

Background technique

At present, the hot water, steam and gas boilers for civil heating are generally selected as products with chamber-fired furnaces with two or three return threaded smoke pipes and external mixing diffuser burners.

However, in the existing boiler structure, the furnace is located below the central axis of the drum, and the second and third return threaded smoke pipes are located above the furnace. Heat medium water flows into the drum from the upper left of the drum, and flows out from the upper right or lower right of the drum. Restricted by the structure, the efficiency of the heat medium water in heat exchange in this structure is relatively low, and there may be dead spots of heat exchange in the lower left and right corners of the drum. Limited by the structure of the boiler, it is difficult to improve the heat exchange efficiency by increasing the volume of the furnace, increasing the heat exchange surface, or increasing the flow rate of the heat medium water.

Therefore, in order to increase the efficiency of heat exchange, it is necessary to increase the combustion temperature of the furnace. However, nitrogen oxides _NOx are produced by chemical reactions with oxygen at high temperatures. The higher the temperature of the furnace, the more nitrogen oxides are generated. The gas is emitted into the atmosphere, thereby causing environmental pollution.

The existing solution is to mix the waste gas discharged from the boiler with the fresh air to reduce the oxygen content of the air, reduce the temperature of the furnace and reduce the generation of nitrogen oxides. The premise of this method is that the volume of the furnace needs to be increased, and the output of the burner also needs to increase the rated power, which greatly increases the cost.

Utility model content

In order to solve the shortcomings of the above-mentioned existing background technology, the utility model designs a chamber-fired water-fire tube set series-connected low-nitrogen high-heat-efficiency boiler. The boiler has changed the structural layout of the entire boiler. By increasing the heat exchange surface and increasing the flow rate of heat medium water, the heat exchange efficiency has been greatly improved, thereby reducing the temperature in the combustion furnace. On the premise of ensuring the overall heat exchange efficiency, it has also reached To reduce the formation of nitrogen oxides.

Concrete technical scheme of the present utility model is:

A chamber-fired water-fire tube set series low-nitrogen high-thermal-efficiency boiler, which includes a drum, a furnace liner, an inner ring of the drum, a front tube plate, a rear tube plate, a burner, a two-pass smoke guide pipe, and a three-pass threaded smoke pipe. Pipe, water inlet water dispenser, water inlet connection elbow, water outlet connection elbow, water inlet header, water outlet header, cold water inlet pipe, hot water outlet pipe, heat exchange pipe and smoke exhaust port;

Furnace liner and drum inner ring are sleeved in the drum from inside to outside and kept coaxial;

A front tube sheet and a rear tube sheet are respectively installed at both ends of the inner ring of the drum and the inner tube of the furnace, so that a heat medium water flow chamber is formed between the inner ring of the drum, the inner ring of the furnace, the front tube sheet and the rear tube sheet;

The front smoke chamber is formed between the drum and the front tube sheet, and the rear smoke chamber is formed between the drum and the rear tube sheet; the rear smoke chamber communicates with the external environment through the smoke exhaust port;

The water inlet header and the water outlet header are respectively installed at both ends of the furnace, and the water outlet header is located on the side of the rear smoke chamber, and the water inlet header is located on the side of the front smoke chamber, so that the water inlet header, the water outlet header and the The furnace chamber constitutes a combustion chamber;

The water inlet header communicates with the heat medium water flow chamber through the water outlet connecting elbow;

The water outlet header communicates with the outside through the hot water outlet pipe;

The burner is inserted along the central axis of the drum, and its ignition position is located in the combustion furnace;

The heat exchange pipes are multiple and evenly distributed in the combustion furnace along the circumferential direction, and connect the water inlet header and the water outlet header;

The inlet water distributor is located in the rear smoke chamber and is set between the water outlet header and the drum. The inlet water distributor communicates with the outside through a cold water inlet pipe, and connects the water inlet elbow with the heat medium water flow chamber. connected;

There are multiple three-pass threaded smoke pipes, which are evenly arranged in the heat medium water flow chamber along the circumferential direction, and one end of the three-pass threaded smoke pipe is connected with the rear smoke chamber, and the other end is connected with the front smoke chamber;

The two return smoke pipes are multiple and evenly distributed along the circumferential direction. The two return smoke pipes include a bent end and a straight section, which communicate with the combustion furnace through the bent section, and the straight section is located in the heat medium water flow chamber. And it communicates with the front smoke chamber.

At the same time, the designed secondary air-poor oxygen-rich combustion method reduces the temperature of the combustion furnace and the flame in the center of the burner, and further reduces the formation of nitrogen oxides. The specific structure is:

The boiler also includes a secondary cyclone assembly arranged in the middle of the drum in the axial direction. The secondary cyclone assembly includes an annular air inlet pipe and multiple air induction pipes; the annular air inlet pipe is set outside the drum, and the multiple air induction pipes are along the Evenly distributed in the circumferential direction, one end of each air induction pipe is connected with the annular air inlet pipe, and the other end is obliquely passed through the drum, the inner ring of the drum, and the furnace in turn, and then enters the combustion furnace, so that the external high-pressure fresh air enters the air from the ring Pipe and a plurality of air induction pipes are screwed into the combustion furnace.

In order to adapt to the thermal expansion and contraction of the boiler and to facilitate maintenance, the boiler drum is wrapped with an outer packing plate, and the outer packing plate is tensioned by a spring.

In order to adapt to the thermal expansion and contraction of the boiler, the tube wall of the furnace is wavy.

In order to avoid the problem of nitrogen oxides produced due to the high initial flame temperature during ignition, the ignition temperature of the burner is 900°-1300°.

Further, in order to prevent potential safety hazards caused by excessive pressure in the boiler, a pressure relief valve is installed on the drum through a pressure relief socket.

Further, the bottom of the above-mentioned drum is installed with a sewage outlet that communicates with the outside and the heat medium water flow chamber.

Further, the bottom of the drum is equipped with a condensed water outlet that communicates with the outside and the rear smoke chamber.

Further, the above-mentioned water inlet connecting elbows and water outlet connecting elbows are multiple.

Further, the pipe diameter of the two-return smoke guide pipe is larger than the pipe diameter of the three-return threaded smoke pipe.

The beneficial effects of the utility model are:

1. In the heat medium water flow chamber of the utility model, a two-return smoke guide pipe and a three-return thread smoke pipe are installed. At the same time, a heat exchange pipe is directly installed in the combustion furnace, and the heat exchange pipe is connected in series with the heat medium water flow chamber. This design greatly increases the radiation heat exchange surface, and the flow rate of the heat medium water increases after the series connection, which can reduce the furnace temperature by timely heat exchange and reduce the generation of nitrogen oxides and carbon dioxide.

2. The secondary cyclone assembly designed by the utility model performs secondary combustion, which ensures the temperature requirements of the entire combustion furnace and reduces the generation of nitrogen oxides and carbon dioxide at the same time when the initial ignition temperature is low.

3. The flue gas in the three-pass threaded flue pipe of the present invention and the flow direction of the heat medium water in the heat medium water flow chamber are opposite. This kind of countercurrent-based heat exchange method greatly improves the heat exchange efficiency.

4. The utility model adopts the method of evenly arranging flue gas passages and heat medium water passages on the circumference, so that the volume of the drum is small, the material consumption is small, the utilization rate of raw materials is high, materials are saved, and product costs are reduced.

5. The utility model adopts the method of spring tightening and fixing the outer packaging board, which is beneficial to the thermal expansion and contraction of the boiler, and is convenient for maintenance.

Description of drawings

Figure 1 is a schematic diagram of the structure of the boiler.

Fig. 2 is a cross-sectional view taken along line A of Fig. 1 .

Figure 3 is a schematic diagram of the flue gas circulation.

FIG. 4 is a cross-sectional view taken along line A of FIG. 3 .

Figure 5 is a schematic diagram of the flow of heat medium water.

FIG. 6 is a sectional view taken along line A of FIG. 5 .

The symbols in the figure are explained as follows:

1-Front tube plate, 2-Drum inner ring, 3-Secondary return smoke pipe, 4-Secondary cyclone assembly, 5-Furnace liner, 6-Pressure relief pipe seat, 7-Three return threaded smoke pipe, 8- Rear tube plate, 9-water inlet connecting elbow, 10-rear smoke chamber, 11-water inlet water dispenser, 12-smoke exhaust port, 13-hot water outlet pipe, 14-cold water inlet pipe, 15-water outlet header , 16-condensate water outlet, 17-drain outlet, 18-boiler leg, 19-combustion furnace, 20-water exchange pipe, 21-front smoke chamber, 22-water outlet connection elbow, 23-asbestos rope, 24-water inlet Header, 25-burner, 26-spring, 27-outer packaging board, 28-drum, 29-heat medium water flow chamber, 30-induction air pipe, 31-annular air intake pipe.

Detailed ways

The utility model will be described in further detail below in conjunction with accompanying drawing:

Referring to Figures 1 and 2, a chamber-fired water-fire tube set series low-nitrogen high-thermal-efficiency boiler includes a drum 28, a furnace liner 5, a drum inner ring 2, a front tube plate 1, a rear tube plate 8, and a burner 25. Second-pass smoke pipe 3. Three-pass threaded smoke pipe 7. Inlet water dispenser 11. Water inlet connecting elbow 9. Outlet connecting elbow 22. Inlet water header 24. Outlet water header 15. Cold water inlet pipe 14. Hot water outlet pipe 13, heat exchange pipe 20 and smoke exhaust port 12;

Furnace gall 5 and drum inner ring 2 are sleeved in the drum 28 from inside to outside in sequence and kept coaxial;

Install the front tube plate 1 and the rear tube plate 8 at both ends of the inner ring 2 of the boiler drum and the furnace tube plate 5 respectively (the positions where the furnace tube 5 is connected to the front tube plate 1 and the rear tube plate 8 are tightly sealed with asbestos rope 23) , so that the heat medium water flow chamber 29 is formed between the drum inner ring 2, the furnace 5, the front tube plate 1 and the rear tube plate 8 (the heat medium water flow chamber is ring-shaped); the drum 28 and the front tube A front smoke chamber 21 (the left end of the drum in FIG. 1 ) is formed between the plates 1, and the rear smoke chamber 10 (the right end of the drum in FIG. 1 ) is formed by the drum 28 and the rear tube plate 8; the rear smoke chamber 10 It communicates with the external environment through the exhaust port 12; the water inlet header 24 and the water outlet header 15 are respectively installed at both ends of the furnace 5, and the water outlet header 15 is located at the side of the rear smoke chamber 10, and the water inlet header 24 is located at the front One side of the smoke chamber 21, thereby forming a combustion furnace 19 by the water inlet header 24, the water outlet header 15 and the furnace;

The burner 25 is inserted along the central axis direction of the drum 28, and its ignition position is located in the combustion furnace 19; The water flow chamber 29 communicates; the water outlet header 15 communicates with the outside through the hot water outlet pipe 13;

The water inlet water dispenser 11 is located in the rear smoke chamber 10 and is arranged between the water outlet header 15 and the drum 28. The water inlet water dispenser 11 communicates with the outside through a cold water inlet pipe 14, and connects the elbow pipe 9 through the water inlet (this During implementation, a plurality of water inlet connecting elbows 9) are communicated with the heat medium water flow chamber 29;

There are multiple three-pass threaded smoke pipes 7, which are evenly arranged in the heat medium water flow chamber 29 along the circumferential direction, and one end of the three-pass threaded smoke pipe 7 communicates with the rear smoke chamber 10, and the other end communicates with the front smoke chamber 21 ;

The two return smoke guide pipes 3 are multiple and evenly distributed along the circumferential direction. The two return smoke guide pipes include a bent end and a straight section. The chamber 29 communicates with the front smoke chamber 21 .

Wherein, the pipe diameter of the second-pass smoke guide pipe 3 is larger than the pipe diameter of the three-pass threaded smoke pipe 7, and the number of the three-pass threaded smoke pipe 7 is twice the number of the two-pass smoke guide pipe.

In the above structure, as shown in Fig. 3 and Fig. 4, the flow of flue gas is as follows: the burner 25 is ignited in the combustion furnace 19, and the hot flue gas generated first reaches the front flue chamber 21 through a plurality of secondary return flue guide pipes 3, From the front smoke chamber 21, it enters into a plurality of three-pass threaded smoke pipes 7, and finally discharges from the rear smoke chamber 10 and the smoke outlet 12 to the outside atmosphere.

As shown in Figure 5 and Figure 6, the flow of heat medium water: the heat medium water enters the water inlet water device 11 from the cold water inlet pipe 14, and then enters the heat medium water flow chamber 29 through a plurality of water inlet connecting elbows 9 Then it enters the water inlet header 24 through a plurality of water outlet connecting elbows 22, and then flows into the outlet water header 15 through a plurality of water exchange pipes 20, and finally flows into the user's use end from the hot water outlet pipe 13.

Heat exchange process: the flue gas in the combustion furnace 19 conducts a heat exchange with the heat medium water in the heat exchange pipe 20, and then the second return smoke guide pipe 3 and the three return thread smoke pipe 7 are used in the heat medium water flow chamber 29 has carried out two heat exchanges with the heat medium water, and during the heat exchange between the three-return threaded smoke pipe 7 and the heat medium water in the heat medium water flow chamber 29, the flow direction of the flue gas in the three-return threaded smoke pipe 7 is the same as The flow direction of the heat medium water in the heat medium water flow chamber 29 is opposite, and the heat exchange efficiency is significantly improved again (because the diameter of the heat exchange water pipe 20 is much smaller than the diameter of the heat medium water flow chamber 29, the water flow in the heat exchange pipe 20 Speed up, thereby can take away the temperature in the combustion chamber 19 fast).

It should also be mentioned that in this example, a plurality of water inlet connecting elbows 9 and outlet water connecting elbows 22 are distributed in dead angle positions of the drum 28 to avoid heat exchange dead angles.

In this implementation, the following optimized designs have also been made:

1. The secondary air-poor oxygen-enriched combustion method not only ensures the combined use requirements of the temperature in the combustion furnace, but also reduces the flame temperature when the burner in the combustion furnace is initially ignited, and further reduces the generation of nitrogen oxides. The specific structure is:

The boiler also includes a secondary cyclone assembly 4 arranged in the middle of the drum 28 in the axial direction. The secondary cyclone assembly 4 includes an annular air inlet pipe 31 and a plurality of air induction pipes 30; the annular air inlet pipe 31 is set on the drum 28 In addition, a plurality of air induction pipes 30 are evenly distributed along the circumferential direction, one end of each air induction pipe 30 communicates with the annular air inlet pipe 31, and the other end passes through the drum 28, the inner ring of the drum 25, and the furnace gall 5 in an inclined manner and then enters Combustion furnace, so that the external high-pressure fresh air is swirled into the combustion furnace 19 from the annular air inlet pipe 31 and a plurality of air induction pipes 30 .

The combustion mechanism of this combustion structure is: when the burner is initially ignited, the burner is adjusted to make it in the state of oxygen-lean combustion ignition in the combustion furnace, so that the temperature at the initial ignition is relatively low (generally, the ignition temperature of the burner is controlled to be 900°-1300°), which will greatly reduce the problem of a large amount of nitrogen oxides due to high-temperature combustion, and then carry out oxygen-supplementing secondary cyclone combustion through the secondary cyclone assembly arranged in the middle of the axial direction of the drum, so that it can The temperature in the combustion furnace is increased again to ensure the heat required by the user after heat exchange.

2. In order to adapt to the thermal expansion and contraction of the boiler, and to facilitate maintenance, the drum 28 is wrapped with an outer packaging plate 27, and the outer packaging plate 27 is tensioned by a spring 26, and the tube wall adopted by the furnace 5 is wavy.

3. In order to prevent potential safety hazards caused by excessive pressure in the boiler, a pressure relief valve is installed on the boiler drum 28 through a pressure relief pipe seat 6 .

4. The bottom of the drum 28 is installed with a sewage outlet 17 connecting the outside and the heat medium water flow chamber 29 , and the bottom of the drum 28 is installed with a condensate outlet 16 connecting the outside and the rear smoke chamber 10 .

5. Boiler legs 18 are provided at the bottom of the drum 28 for support.

Claims (10)

1. the utility model provides a room fire water and fire tube suit polyphone formula low nitrogen high heat efficiency boiler which characterized in that:

The boiler comprises a boiler barrel (28), a boiler furnace (5), a boiler barrel inner ring (2), a front pipe plate (1), a rear pipe plate (8), a burner (25), a two-return smoke guide pipe (3), a three-return threaded smoke pipe (7), a water inlet water distributor (11), a water inlet connecting bent pipe (9), a water outlet connecting bent pipe (22), a water inlet header (24), a water outlet header (15), a cold water inlet pipe (14), a hot water outlet pipe (13), a heat exchange water pipe (20) and a smoke exhaust port (12);

The furnace pipe (5) and the inner ring (2) of the boiler barrel are sequentially sleeved in the boiler barrel (28) from inside to outside and keep coaxial;

a front tube plate (1) and a rear tube plate (8) are respectively arranged at two ends of the inner drum ring (2) and the furnace pipe (5), so that a hot medium water flowing chamber (29) is formed among the inner drum ring (2), the furnace pipe (5), the front tube plate (1) and the rear tube plate (8);

A front smoke chamber (21) is formed between the boiler barrel (28) and the front tube plate (1), and a rear smoke chamber (10) is formed between the boiler barrel (28) and the rear tube plate (8); the rear smoke chamber (10) is communicated with the external environment through a smoke outlet (12);

The water inlet collecting box (24) and the water outlet collecting box (15) are respectively arranged at two ends of the furnace pipe (5), the water outlet collecting box (15) is positioned at one side of the rear smoke chamber (10), the water inlet collecting box (24) is positioned at one side of the front smoke chamber (21), and therefore the water inlet collecting box (24), the water outlet collecting box (15) and the furnace pipe (5) form a combustion furnace chamber (19);

The water inlet header (24) is communicated with the heat medium water flowing chamber (29) through the water outlet connecting bent pipe (22);

The water outlet header (15) is communicated with the outside through a hot water outlet pipe (13);

The burner (25) is inserted along the central axis direction of the boiler barrel (28), and the ignition part of the burner is positioned in the combustion hearth (19);

The heat exchange water pipes (20) are uniformly distributed in the combustion furnace (19) along the circumferential direction and communicate the water inlet header (24) with the water outlet header (15);

the water inlet and water separator (11) is positioned on one side of the rear smoke chamber (10) and is arranged between the water outlet header (15) and the boiler barrel (28), and the water inlet and water separator (11) is communicated with the outside through a cold water inlet pipe (14) and is communicated with the heat medium water flowing chamber (29) through a water inlet connecting bent pipe (9);

The three-return-stroke threaded smoke pipes (7) are uniformly arranged in the heat medium water flowing chamber (29) along the circumferential direction, one end of each three-return-stroke threaded smoke pipe (7) is communicated with the rear smoke chamber (10), and the other end of each three-return-stroke threaded smoke pipe is communicated with the front smoke chamber (21);

The two return smoke guide pipes (3) are uniformly distributed along the circumferential direction and comprise bent ends and straight sections, the bent ends are communicated with the combustion hearth (19) through the bent sections, and the straight sections are located in the heat medium water flow chamber (29) and communicated with the front smoke chamber (21).

2. the chamber-fired water and fire tube jacketed series low-nitrogen high-heat-efficiency boiler of claim 1, characterized in that:

The boiler also comprises a secondary cyclone component (4) arranged in the middle of the boiler barrel (28) in the axial direction, wherein the secondary cyclone component (4) comprises an annular air inlet pipe (31) and a plurality of air guide pipes (30); the annular air inlet pipe (31) is sleeved outside the boiler, a plurality of air guiding pipes (30) are uniformly distributed along the circumferential direction, one end of each air guiding pipe (30) is communicated with the annular air inlet pipe (31), and the other end of each air guiding pipe obliquely penetrates through the boiler barrel (28), the boiler barrel inner ring (2) and the boiler furnace (5) in sequence and then enters the combustion hearth (19).

3. the chamber-fired water and fire tube jacketed series low-nitrogen high-heat-efficiency boiler of claim 1 or 2, characterized in that:

the outer packaging plate (27) is wrapped outside the boiler barrel (28), and the outer packaging plate (27) is tensioned by a spring (26).

4. The chamber-fired water and fire tube jacketed series low-nitrogen high-heat-efficiency boiler of claim 3, characterized in that:

The wall of the furnace pipe (5) is wave-shaped.

5. The chamber-fired water and fire tube jacketed series low-nitrogen high-heat-efficiency boiler of claim 4, wherein: the ignition temperature of the burner (25) is 900 DEG to 1300 deg.

6. The chamber-fired water and fire tube jacketed series low-nitrogen high-heat-efficiency boiler of claim 5, wherein: the boiler barrel (28) is connected with and provided with a pressure release valve through a pressure release pipe seat (6).

7. The chamber-fired water and fire tube jacketed series low-nitrogen high-heat-efficiency boiler of claim 6, wherein: and a sewage draining outlet (17) communicated with the outside and the heat medium water flowing chamber (29) is arranged at the bottom of the boiler barrel (28).

8. The chamber-fired water and fire tube jacketed series low-nitrogen high-heat-efficiency boiler of claim 7, wherein: and a condensed water outlet (16) communicated with the outside and the rear smoke chamber (10) is arranged at the bottom of the boiler barrel (28).

9. the chamber-fired water and fire tube jacketed series low-nitrogen high-heat-efficiency boiler of claim 8, wherein: the water inlet connecting bent pipe (9) and the water outlet connecting bent pipe (22) are multiple.

10. the chamber-fired water and fire tube jacketed series low-nitrogen high-heat-efficiency boiler of claim 9, wherein: the pipe diameter of the two-return smoke guide pipe (3) is larger than that of the three-return threaded smoke pipe (7).