CN110657414A - Direct-flow steam generator - Google Patents

Abstract

A direct current steam generator relates to the field of steam generators. In order to solve the problem of long start-up time and poor thermal efficiency of traditional drum boilers, which lead to high operating costs, and traditional boilers have large water capacity, sometimes there is the possibility of steam explosion and low reliability. The lower part of the shell is cylindrical, and one end of the lower part of the shell is provided with a burner, and the burner is arranged in communication with the lower part of the shell, and there are n high-temperature area radiation heat pipes inside the lower part of the shell, where n is a positive integer and is parallel to the Setting, the inner wall of the lower part of the shell is uniformly provided with m water cooling walls along the circumferential direction, m is a positive integer, the other end of the lower part of the shell is provided with an upper part of the shell along the outer surface of the circumference, and the upper part of the shell is connected with the lower part of the shell The low temperature area convection heating unit is vertically arranged inside the upper part of the casing. The invention is suitable for the fields of chemical industry, cast iron, mobile heating, pharmacy and sterilization, and can also be applied to steam injection boilers for oilfield steam injection exploitation and power station start-up furnaces.

Description

A direct current steam generator

technical field

The invention relates to the field of steam generators, in particular to a once-through steam generator.

Background technique

For more than 100 years, boilers have been widely used in various industrial fields as traditional general equipment. The startup loss range of traditional drum boilers is generally 2-20% of the daily fuel cost, and depending on the number of startups, the size of the boiler and the steam system, this loss accumulates hugely after a long period of operation. At the same time, the natural circulation type drum boiler consumes a large amount of metal and lags behind the adjustment response. These shortcomings have seriously restricted its development and application in the future.

In summary, the traditional drum boiler has a long start-up time and poor thermal efficiency, resulting in high operating costs, and the traditional boiler has a large water capacity, sometimes there is the possibility of steam explosion, and the reliability is low. .

SUMMARY OF THE INVENTION

The invention solves the problems of the traditional steam drum boiler with long start-up time and poor thermal efficiency, resulting in high operating cost, and the traditional boiler has a large water capacity, and sometimes there is the possibility of steam explosion and low reliability. A direct current steam generator is proposed.

The once-through steam generator of the present invention is composed of radiant heat-receiving tubes in a high-temperature area, a burner, a water-cooled wall, a lower part of a casing, a convection heating unit in a low-temperature area and an upper part of the casing;

The lower part of the casing is cylindrical, and one end of the lower part of the casing is provided with a burner, and the burner is arranged in communication with the lower part of the casing. There are n high-temperature area radiation heat pipes inside the lower part of the casing, where n is a positive integer and is parallel to the Setting, the inner wall of the lower part of the shell is uniformly provided with m water cooling walls along the circumferential direction, m is a positive integer, the other end of the lower part of the shell is provided with an upper part of the shell along the outer surface of the circumference, and the upper part of the shell is connected with the lower part of the shell The convection heating unit in the low temperature area is vertically arranged inside the upper part of the shell;

Further, the top of the lower part of the casing is provided with a smoke exhaust;

Further, the smoke exhaust port is a conical port;

Further, the low temperature area convection heating unit includes an economizer, an evaporator and a superheater, and the economizer, the evaporator and the superheater are arranged in sequence from top to bottom;

Further, the number n of the radiation heat-receiving tubes in the high temperature area is 10≤n≤200;

Further, the number m of the water cooling walls, 1≤m≤5;

Further, when in use, the fuel is put into the burner, and the air flows into the burner, and the micro-positive pressure combustion is carried out in the furnace (radiant section), and the flue gas flows horizontally through the furnace and enters upward from the rear of the furnace. In the convection section, the flue gas is finally discharged into the chimney after heat exchange in the convection section. The water flow direction is opposite to the flue gas flow direction, so as to form countercurrent heat exchange with the high temperature flue gas generated by the burner, and the flow direction of the flue gas is affected by the radiation in the high temperature area. The heat pipes are parallel and can be fully exchanged. When the flue gas flows through the radiant heat receiving pipe in the high temperature area, it passes through the convection heating unit in the low temperature area, and the flow direction of the flue gas is perpendicular to the convection heating unit in the low temperature area, and the flue gas is heated in the heating surface tube. For the flowing medium (steam, water), the temperature of the flue gas gradually decreases due to the continuous heat exchange between the flue gas and the medium in the heating surface tube;

After the feed water is pressurized by the external pump, it enters the economizer to heat up. After the economizer comes out, it enters the radiant section furnace to absorb heat and becomes a steam-water mixture. After the steam-water mixture is separated by the steam-water separator, the steam enters the superheater and becomes superheated steam. The saturated water is separated from the steam-water separator to heat the boiler make-up water to increase the make-up water temperature. When saturated steam is generated, no superheater is arranged.

Compared with the prior art, the present invention has the following beneficial effects:

1. The present invention overcomes the shortcomings of the prior art, and adopts such a device to recover and convert the chemical energy of combustion into thermal energy for industrial production, thereby improving thermal efficiency.

2. The present invention adopts the radiation heating tube in the high temperature area and the convection heating unit in the low temperature area, the flue gas flows through the radiation heating tube in the high temperature area and the convection heating unit in the low temperature area, and the flue gas heats the medium (steam, water) flowing in the heating surface tube. The continuous heat exchange between the flue gas and the medium in the heating surface pipe makes the temperature of the flue gas gradually decrease, the water capacity is less, the phenomenon of steam explosion is avoided, the safety is improved, and the reliability is higher.

3. The present invention overcomes the shortcomings of the prior art, the time for starting the steam generator for the first time is shorter, the operation cost is reduced, and the economic benefit is improved.

Fourth, the present invention is small in size, saves space, and is convenient for maintenance.

Description of drawings

Fig. 1 is a sectional view of a straight-through steam generator of the present invention;

Fig. 2 is the side view of a kind of once-through steam generator of the present invention;

Fig. 3 is the schematic diagram of flue gas flow in a direct current steam generator according to the present invention;

FIG. 4 is a schematic diagram of the steam-water flow in a once-through steam generator according to the present invention.

Detailed ways

Embodiment 1: This embodiment will be described with reference to FIG. 1 to FIG. 4. A direct-flow steam generator described in this embodiment includes a high-temperature area radiation heat-receiving tube 1, a burner 2, a water-cooled wall 3, a lower shell 4, and a low-temperature area. District convection heating unit 5 and the upper part of the shell 6;

The lower part 4 of the casing is cylindrical, and one end of the lower part 4 of the casing is provided with a burner 2, and the burner is arranged in communication with the lower part 4 of the casing, and the inner part of the lower part 4 of the casing is provided with n high temperature area radiation heat pipes 1, n It is a positive integer and is arranged in parallel. The inner wall of the lower shell 4 is evenly provided with m water cooling walls 3 along the circumferential direction, where m is a positive integer. The other end of the lower shell 4 is provided with an upper shell 6 along the outer surface of the circumference. , and the upper part 6 of the casing is arranged in communication with the lower part 4 of the casing, and the convection heating unit 5 in the low temperature area is vertically arranged inside the upper part 6 of the casing;

In this specific embodiment, when in use, the fuel is put into the burner 2, and the air flows into the burner 2, and the micro-positive pressure combustion is carried out in the furnace (radiation section), and the flue gas flows horizontally through the furnace, from the furnace The rear goes up into the convection section, and finally the flue gas is discharged into the chimney through the convection section heat exchange. The radiant heating tubes 1 in the high temperature area are parallel to each other and can be fully exchanged. When the flue gas flows through the radiant heating tubes 1 in the high temperature area, it passes through the convection heating unit 5 in the low temperature area, and the flow direction of the flue gas is perpendicular to the convection heating unit 5 in the low temperature area. , the flue gas heats the medium (steam, water) flowing in the heating surface tube. Due to the continuous heat exchange between the flue gas and the medium in the heating surface tube, the temperature of the flue gas gradually decreases.

Embodiment 2: This embodiment is described with reference to FIG. 2. This embodiment is a further limitation of the generator described in Embodiment 1. For a direct current steam generator described in this embodiment, the casing The top of the lower part 4 is provided with a smoke exhaust port 7 .

Embodiment 3: This embodiment will be described with reference to FIG. 2 . This embodiment is a further limitation of the generator described in Embodiment 2. For a direct current steam generator described in this Port 7 is a conical port;

In this specific embodiment, the smoke exhaust port 7 is used as a conical port, so that the flue gas can be collected in one place for discharge.

Embodiment 4: This embodiment will be described with reference to FIG. 3 . This embodiment is a further limitation of the generator described in Embodiment 1. For a direct current steam generator described in this embodiment, the low temperature region The convection heating unit 5 includes an economizer 5-1, an evaporator 5-2 and a superheater 5-3, which are sequentially provided with an economizer 5-1, an evaporator 5-2 and a superheater 5-3 from top to bottom;

In this specific embodiment, a high-temperature area radiant heat-receiving tube 1 and a low-temperature area convective heating unit 5 are used, and the flue gas flows through the high-temperature area radiant heat-receiving tube 1 and the low-temperature area convective heating unit 5, and the flue gas heats the medium (steam) flowing in the heating surface tube. Due to the continuous heat exchange between the flue gas and the medium in the heating surface tube, the temperature of the flue gas is gradually reduced, the water capacity is reduced, the phenomenon of steam explosion is avoided, the safety is improved, and the reliability is high;

After the feed water is pressurized by the external pump, it enters the economizer 5-1 to heat up. After the economizer 5-1 comes out, it enters the radiant section furnace to absorb heat and becomes a steam-water mixture. After the steam-water mixture is separated by the steam-water separator, the steam enters the superheater. 5-3 is heated to become superheated steam, and the saturated water is separated from the steam-water separator to heat the boiler to make up water and increase the temperature of the make-up water. When saturated steam is generated, no superheater 5-3 is arranged.

Embodiment 5: This embodiment will be described with reference to FIG. 2 . This embodiment is a further limitation of the generator described in Embodiment 1. The direct current steam generator described in this The number n of radiant heat pipes 1, 10≤n≤200;

In this specific embodiment, the number n of radiant heat receiving tubes 1 in the high temperature area is used, 10≤n≤200, the flue gas output from the burner 2 can be heated at a high temperature, and heat can be exchanged with the medium in the radiant heat receiving pipe 1 in the high temperature area. .

Embodiment 6: This embodiment is described with reference to FIG. 2 and FIG. 3 . This embodiment is a further limitation of the generator described in Embodiment 1. For a direct current steam generator described in this embodiment, the The number m of the water cooling walls 3, 1≤m≤5.

Embodiment 7: This embodiment will be described with reference to FIG. 2 and FIG. 3 . This embodiment is a further limitation of the generator described in Embodiment 1. For a direct current steam generator described in this embodiment, the The convection heating unit 5 in the low temperature area adopts a warped tube.

working principle

When in use, the fuel is put into the burner 2, and the air flows into the burner 2, and the micro-positive pressure combustion is carried out in the furnace (radiant section), and the flue gas flows horizontally through the furnace, and enters the convection from the rear of the furnace. Finally, the flue gas is discharged into the chimney after heat exchange in the convection section. The water flow direction is opposite to the flue gas flow direction, thus forming a countercurrent heat exchange with the high temperature flue gas generated by the burner, and the flow direction of the flue gas is the same as that of the radiant heat pipe in the high temperature area. 1 is parallel and can be fully exchanged. When the flue gas flows through the radiation heating tube 1 in the high temperature area, and passes through the convection heating unit 5 in the low temperature area, and the flow direction of the flue gas is perpendicular to the convection heating unit 5 in the low temperature area, the flue gas is heated at For the medium (steam, water) flowing in the heating surface tube, the temperature of the flue gas gradually decreases due to the continuous heat exchange between the flue gas and the medium in the heating surface tube;

After the feed water is pressurized by the external pump, it enters the economizer 5-1 to heat up. After the economizer 5-1 comes out, it enters the radiant section furnace to absorb heat and becomes a steam-water mixture. After the steam-water mixture is separated by the steam-water separator, the steam enters the superheater. 5-3 is heated to become superheated steam, and the saturated water is separated from the steam-water separator to heat the boiler to make up water and increase the temperature of the make-up water. When saturated steam is generated, no superheater 5-3 is arranged.

Claims (6)

1. A once-through steam generator, comprising: the device comprises a high-temperature zone radiation heating tube (1), a burner (2), a water-cooled wall (3), a shell lower part (4), a low-temperature zone convection heating unit (5) and a shell upper part (6);

the shell lower part (4) is cylindrical, a combustor (2) is arranged at one end of the shell lower part (4) and is communicated with the shell lower part (4), n high-temperature zone radiation heating tubes (1) are arranged inside the shell lower part (4), n is a positive integer and is arranged in parallel, m water cooling walls (3) are uniformly arranged on the inner wall of the shell lower part (4) along the circumferential direction, m is a positive integer, a shell upper part (6) is arranged at the other end of the shell lower part (4) along the circumferential outer surface and is communicated with the shell lower part (4), and a low-temperature zone convection heating unit (5) is vertically arranged inside the shell upper part (6).

2. A once-through steam generator according to claim 1, wherein: the top end of the lower part (4) of the shell is provided with a smoke outlet (7).

3. A once-through steam generator according to claim 2, wherein: the smoke outlet (7) is a conical outlet.

4. A once-through steam generator according to claim 1, wherein: the low-temperature-region convection heating unit (5) comprises an economizer (5-1), an evaporator (5-2) and a superheater (5-3), and the economizer (5-1), the evaporator (5-2) and the superheater (5-3) are sequentially arranged from top to bottom.

5. A once-through steam generator according to claim 1, wherein: the number n of the high-temperature zone radiation heated tubes (1) is more than or equal to 10 and less than or equal to 200.

6. A once-through steam generator according to claim 1, wherein: the number m of the water-cooled walls (3) is more than or equal to 1 and less than or equal to 5.

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