CN109099715B - A kind of recuperative heater for removing heat storage based on flue gas - Google Patents

Abstract

The invention discloses a regenerative heating furnace based on a flue gas removing a regenerative body. The regenerative heating furnace introduces the flue gas from the second gas port into the first gas port at the moment when the supply of coal gas and air is stopped, and the regenerative heating furnace has no effect on the storage. The residual gas in the hot body and related pipelines is purged and removed. When the regenerative heating furnace switches the flue gas flow direction, the residual gas caused by no reversal is released into the atmosphere, which solves the problems of technical emission of harmful gases, serious environmental pollution and serious pollution of high-quality gas in the existing regenerative heating furnaces. technical waste.

Description

A regenerative heating furnace based on flue gas removal regenerator

technical field

The invention belongs to the technical field of energy saving and emission reduction of regenerative heating furnaces, and in particular relates to a regenerative heating furnace based on flue gas removing a regenerative body.

Background technique

In the production of iron and steel industry and building materials industry, a large number of regenerative heating furnaces undertake heavy material heating tasks. The regenerative heating furnace adopts the reversing combustion technology to realize the high temperature waste heat recovery and the high temperature preheating of the low calorific value gas. At the same time, high-temperature preheating of low calorific value gas (preheating temperature up to 900℃-1000℃) is realized. Taking the regenerative heating furnace for steel rolling as an example, the regenerative heating furnace for steel rolling generally uses blast furnace gas (CO content 20 %-30%) and converter gas (CO content 60%-80%), the principle of high-temperature flue gas waste heat recovery: dozens of pairs of regenerators are arranged symmetrically on both sides of the heating furnace, when the fuel and air flow from one side of the furnace (definition When it is injected into the A side), the fuel and air are preheated to above 900 ℃ by the high temperature regenerator on this side, and then enter the heating furnace for combustion. After being discharged from the heat accumulator, the high-temperature flue gas will release heat to the heat accumulator when passing through the heat accumulator on this side, and heat the heat accumulator to a high temperature (the maximum temperature is above 1000°C). After running for a period of time (usually about 90s), the gas-flue gas flow direction is switched through the reversing valve, the fuel and air are injected from the B side of the furnace, and the flue gas is switched from the A side outlet. High-temperature preheating of low calorific value fuel and efficient recovery of high-temperature flue gas waste heat are realized in the continuous switching.

However, this technology also has very serious technical defects. During the reversing process of the regenerative heating furnace, the regenerator on one side of the burner is switched to the flue gas discharge flue. The gas remaining in the pipeline between the reversing valve and the regenerator is discharged to the atmosphere. Take the steel rolling regenerative heating furnace as an example to illustrate the defects of this technology:

1) A large amount of toxic gas will be discharged into the atmosphere each time it is switched, resulting in very serious technical discharge of harmful gas (CO has high toxicity).

2) Each switch will discharge a certain amount of gas into the atmosphere without combustion, resulting in a technical waste of high-quality gas fuel.

Taking a medium-sized heating furnace as an example, there are 80 pairs of regenerators in total. The volume of each pair of regenerators and related pipes is 0.3Nm ³ , and ^{24Nm 3} of gas will be released into the air for each reversal. The gas is discharged into the atmosphere. According to the calorific value of 1000Kcal/Nm ³ , which is equivalent to 1086.4 tons of standard coal, and calculated according to the CO content of 25%, 1,900,800Nm ³ of gas will be discharged into the atmosphere. Each person in a medium-sized city with a population of 10,000 breathes 1 CO per year, causing shocking pollution to the environment.

SUMMARY OF THE INVENTION

In view of the problem of gas discharge in the reversing process of the regenerative heating furnace in the prior art, the purpose of the present invention is to provide a regenerative heating furnace based on the removal of the regenerative body based on the flue gas.

The purpose of the present invention is achieved through the following technical solutions.

A regenerative heating furnace based on a flue gas removal regenerator, comprising: a furnace body, a first four-way reversing valve, a second four-way reversing valve, a first three-way reversing valve and a second three-way reversing valve A direction valve, a first opening and a second opening are formed on one side of the furnace body, a third opening and a fourth opening are formed on the other side of the furnace body, and the first opening communicates with a first pipeline , the second opening is connected with a second pipeline, the third opening is connected with a third pipeline, the fourth opening is connected with a fourth pipeline, and the first four-way reversing valve is connected with the the first pipeline, the third pipeline, the fifth pipeline and the sixth pipeline, so that the first pipeline is communicated with one of the fifth pipeline and the sixth pipeline and the The third pipeline communicates with the other of the fifth pipeline and the sixth pipeline; the second four-way reversing valve communicates with the second pipeline, the fourth pipeline and the seventh pipeline respectively. pipeline and an eighth pipeline, so that the second pipeline communicates with one of the seventh pipeline and the eighth pipeline and the fourth pipeline communicates with the seventh pipeline and The other pipeline in the eighth pipeline is connected; the first three-way reversing valve is connected with the air inlet pipeline, the first blowing pipeline and the fifth pipeline respectively, so that the fifth pipeline can be It is communicated with any one of the air inlet pipeline and the first blowing pipeline, wherein a first compressor is installed on the air inlet pipeline, and the other port of the first blowing pipeline is connected to The sixth pipeline is connected, and a first fan is installed on the first blowing pipeline; the second three-way reversing valve is connected with the gas inlet pipeline, the second blowing pipeline and the seventh pipeline respectively , so that the seventh pipeline can be communicated with any one of the gas inlet pipeline and the second blowing pipeline, wherein a second compressor is installed on the gas inlet pipeline, and the second The other port of the blowing pipeline is communicated with the eighth pipeline, and a second fan is installed on the second blowing pipeline;

A heat storage body is installed on the first opening, the second opening, the third opening and the fourth opening, so that the gas passing through the first opening, the second opening, the third opening and the fourth opening can respectively Regenerators passing through corresponding openings.

In the above technical solution, a first induced draft fan is installed on the sixth pipeline between the first blowing pipeline and the first four-way reversing valve.

In the above technical solution, a second induced draft fan is installed on the eighth pipeline between the second blowing pipeline and the second four-way reversing valve.

In the above technical solution, the ports of the sixth pipeline and the eighth pipeline are respectively fixed with a chimney.

The use method of the above-mentioned regenerative heating furnace includes the following steps:

1) Adjust the first three-way reversing valve and the second three-way reversing valve to make the fifth pipeline communicate with the air inlet pipeline, and the seventh pipeline and the gas inlet pipeline connected;

2) Adjust the first four-way reversing valve to connect the first pipeline with the fifth pipeline, and connect the sixth pipeline with the third pipeline; adjust the second four-way valve Open the reversing valve to make the second pipeline communicate with the seventh pipeline, the fourth pipeline and the eighth pipeline, open the first compressor and the second compressor, so that the Coal gas and air are respectively introduced into the corresponding gas inlet pipeline and air inlet pipeline;

3) Switch the flow direction of the flue gas (the flue gas is mixed with coal gas): stop the gas and air from entering the corresponding gas inlet pipelines and air inlet pipelines respectively, close the first pressurizer and the second pressurizer machine, adjust the first three-way reversing valve and the second three-way reversing valve, so that the fifth pipeline is connected with the first blowing pipeline, and the seventh pipeline is connected with the second blowing pipeline The pipeline is connected; the first fan and the second fan are turned on, and the first fan and the second fan are turned off after N seconds;

4) Adjust the first three-way reversing valve and the second three-way reversing valve to make the fifth pipeline communicate with the air inlet pipeline, and the seventh pipeline and the gas inlet pipeline Connect; adjust the first four-way reversing valve to make the first pipeline communicate with the sixth pipeline, and the fifth pipeline communicate with the third pipeline; adjust the second four-way valve Connect the reversing valve to make the second pipeline communicate with the eighth pipeline, the fourth pipeline and the seventh pipeline, open the first compressor and the second compressor, so that the Coal gas and air are respectively introduced into the corresponding gas inlet pipelines and air inlet pipelines.

In the above technical solution, the N is less than or equal to 600 seconds.

Compared with the prior art, the beneficial effects of the regenerative heating furnace of the present invention are:

When the regenerative heating furnace switches the flue gas flow direction, the residual gas caused by no reversal is released into the atmosphere, which solves the technical emission of harmful gases in the existing regenerative heating furnace, serious environmental pollution, and relatively serious problems of high-quality gas. Technical waste.

Description of drawings

Fig. 1 is the working state schematic diagram of the regenerative heating furnace of the present invention;

Fig. 2 is the state schematic diagram when the regenerative heating furnace of the present invention is purged;

FIG. 3 is a schematic diagram of the working state of the regenerative heating furnace of the present invention after switching is completed.

in,

1: Second opening 2: First opening 3: Furnace body 4: Flame

5: Fourth opening 6: Third opening 7: Second press

8: Second three-way reversing valve 9: Chimney 10: Second induced draft fan

11: The second four-way reversing valve 12: The first four-way reversing valve 13: The first induced draft fan

14: The first three-way reversing valve 15: The first pipeline 16: The first compressor

17: Second fan 18: First fan 19: Second pipeline

20: Fifth pipeline 21: Sixth pipeline 22: Third pipeline

23: Seventh line 24: Fourth line 25: Eighth line

26: Inlet air line 27: First blowing line 28: Inlet gas line

29: The second blowing line.

Detailed ways

In the description of the present invention, it should be noted that the orientations or positional relationships indicated by the terms "upper", "lower", "left", "right", etc. are all based on the orientations or positional relationships shown in the drawings, or are The orientation or positional relationship that is usually placed when the invention is used is only for the convenience of describing the invention and simplifying the description, rather than indicating or implying that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore It should not be construed as a limitation of the present invention. Furthermore, the terms "first", "second", "third", etc. are only used to differentiate the description and should not be construed as indicating or implying relative importance.

A method for using flue gas to remove a regenerator and reversing residual gas in a regenerative heating furnace in a regenerative heating furnace, comprising the following steps:

① Make the gas and combustion-supporting air pass into the furnace body through the first air port on the furnace body, the gas and air are burned in the furnace body to form flue gas, and the flue gas is discharged to the outside of the furnace body through the second air port on the furnace body;

② Stop feeding gas and air into the furnace body, and introduce the flue gas discharged from the second gas port into the furnace body from the first gas port for N seconds, and N is less than or equal to 600 seconds; (at the moment when the supply of gas and air is stopped , the flue gas from the second gas port is introduced into the first gas port, and the residual gas in the regenerator and related pipelines is purged and removed).

Preferably, in step ②, the flue gas is pressurized and introduced into the furnace body.

③Introduce gas and air into the furnace body again: make the gas and air enter the furnace body through the second gas port, the gas and air are burned in the furnace body to form flue gas, and the flue gas is discharged to the outside of the furnace body through the first gas port on the furnace body;

Wherein, the number of the first air port is at least one, the number of the second air port is at least one, and a heat storage body is installed on both the first air port and the second air port.

After step ③, repeat steps ① to ③.

The above method can be realized by the following regenerative heating furnace. As shown in Figures 1 to 3, it includes: a furnace body 3, a first four-way reversing valve 12, a second four-way reversing valve 11, a first three-way reversing valve 14 and a second three-way reversing valve 8, A first opening 2 and a second opening 1 (equivalent to the first gas port in the method) are formed on one side of the furnace body 3 , and a third opening 6 and a fourth opening 5 (equivalent to the first gas port in the method) are formed on the other side of the furnace body 3 The second air port in the method), the first opening 2 is connected to the first pipeline 15, the second opening 1 is connected to the second pipeline 19, the third opening 6 is connected to the third pipeline 22, and the fourth opening 5 is connected to the fourth pipeline. Pipeline 24, the first four-way reversing valve 12 is respectively connected with the first pipeline 15, the third pipeline 22, the fifth pipeline 20 and the sixth pipeline 21, so that the first pipeline 15 and the fifth pipeline The second four-way reversing valve 11 The second pipeline 19 , the fourth pipeline 24 , the seventh pipeline 23 and the eighth pipeline 25 are respectively connected, so that the second pipeline 19 is connected to one of the seventh pipeline 23 and the eighth pipeline 25 The pipelines are connected and the fourth pipeline 24 is connected with another pipeline in the seventh pipeline 23 and the eighth pipeline 25; the first three-way reversing valve 14 is respectively connected with the air inlet pipeline 26 and the first blowing pipe The pipeline 27 is connected with the fifth pipeline 20, so that the fifth pipeline 20 can be communicated with any one of the air inlet pipeline 26 and the first blowing pipeline 27, wherein the air inlet pipeline 26 is installed with a In the first compressor 16, the other port of the first blowing line 27 is communicated with the sixth line 21, and a first blower 18 is installed on the first blowing line 27; the second three-way reversing valve 8 is respectively It communicates with the gas inlet pipeline 28, the second blowing pipeline 29 and the seventh pipeline 23, so that the seventh pipeline 23 can communicate with any one of the gas inlet pipeline 28 and the second blowing pipeline 29, wherein , a second compressor 7 is installed on the gas inlet pipeline 28, the other port of the second blowing pipeline 29 is communicated with the eighth pipeline 25, and a second blower 17 is installed on the second blowing pipeline 29;

A heat storage body is installed on the first opening 2 , the second opening 1 , the third opening 6 and the fourth opening 5 so as to pass through the first opening 2 , the second opening 1 , the third opening 6 and the fourth opening 5 The gas can respectively pass through the corresponding opening of the heat storage body.

Preferably, a first induced draft fan 13 is installed on the sixth pipeline 21 between the first blowing pipeline 27 and the first four-way reversing valve 12 .

Preferably, a second induced draft fan 10 is installed on the eighth pipeline 25 between the second blowing pipeline 29 and the second four-way reversing valve 11 .

Preferably, a chimney 9 is respectively installed at the ports of the sixth pipeline 21 and the eighth pipeline 25 .

The use method of the above-mentioned regenerative heating furnace includes the following steps:

1) Adjust the first three-way reversing valve 14 and the second three-way reversing valve 8, so that the fifth pipeline 20 is connected with the air inlet pipeline 26, and the seventh pipeline 23 is connected with the gas inlet pipeline 28;

2) Adjust the first four-way reversing valve 12 to make the first pipeline 15 communicate with the fifth pipeline 20, and the sixth pipeline 21 and the third pipeline 22; adjust the second four-way reversing valve 11 to make the The second pipeline 19 is connected to the seventh pipeline 23, the fourth pipeline 24 is connected to the eighth pipeline 25, the first compressor 16 and the second compressor 7 are turned on, and the gas and air are respectively introduced into the corresponding The gas inlet pipeline 28 and the inlet air pipeline 26;

3) Switch the flow direction of the flue gas: stop the gas and air from entering the corresponding gas inlet pipeline 28 and air inlet pipeline 26 respectively, close the first compressor 16 and the second compressor 7, adjust the first three Through the reversing valve 14 and the second three-way reversing valve 8, the fifth pipeline 20 is connected with the first blowing pipeline 27, and the seventh pipeline 23 is connected with the second blowing pipeline 29; open the first fan 18 and For the second fan 17, the first fan 18 and the second fan 17 are turned off after N seconds; N is less than or equal to 600 seconds.

4) Adjust the first three-way reversing valve 14 and the second three-way reversing valve 8, so that the fifth pipeline 20 is connected with the air inlet pipeline 26, and the seventh pipeline 23 is connected with the gas inlet pipeline 28; A four-way reversing valve 12 makes the first pipeline 15 communicate with the sixth pipeline 21, and the fifth pipeline 20 communicates with the third pipeline 22; adjust the second four-way reversing valve 11, so that the second pipeline 19 is connected to the eighth pipeline 25, the fourth pipeline 24 is connected to the seventh pipeline 23, the first compressor 16 and the second compressor 7 are turned on, and the gas and air are respectively passed into the corresponding gas inlet pipelines 28 and intake air line 26.

Repeat steps 1) to 4).

The technical solutions of the present invention are further described below in conjunction with specific embodiments.

As shown in Figure 1, at a certain moment, the left side of the regenerative heating furnace is the combustion side, and gas and combustion-supporting air are injected from the first opening (gas inlet) and the second opening (air inlet) of the furnace hearth, located in the first The regenerators of the opening and the second opening release heat to the gas and air to preheat the corresponding air and gas. The right side of the regenerative heating furnace is the flue gas discharge side, that is, the waste heat recovery side of the high-temperature flue gas. The opening and the fourth opening lead out.

The position of the reversing valve at this time: the second three-way reversing valve 8 is in the gas connection position, and the second four-way reversing valve 11 is in the position where the second opening 1 can be connected to the gas, that is, the gas inlet pipeline 28 is connected to the gas. The seventh pipeline 23 is connected, and the seventh pipeline 23 is connected with the second pipeline 19 ; at this time, the fourth pipeline is connected with the eighth pipeline, so that the second induced draft fan 10 is connected with the fourth opening 5 . The first three-way reversing valve 14 is in a position connected to the air, and the first four-way reversing valve 12 is connected to the first opening, that is, the air inlet pipeline is connected to the fifth pipeline, and the fifth pipeline 20 is connected to the first opening. The first pipeline 15 is connected; at this time, the sixth pipeline 21 is connected with the third pipeline 22, so that the first induced draft fan 13 is connected with the third opening.

Gas flow: After the gas is pressurized by the second pressurizer 7, the gas enters the second three-way reversing valve 8, continues to flow through the second four-way reversing valve 11, and then enters the second opening 1 through the second pipeline 19. After passing through the regenerator at the second opening, the gas and the regenerator exchange heat and heat up and are sprayed into the furnace body 3 for combustion to generate a flame 4 .

Combustion-supporting air flow: after the air is pressurized by the first compressor 16, it enters the first three-way reversing valve 14, then flows through the first four-way reversing valve 12, and then enters the first opening 2 through the first pipeline 15. , and exchange heat with the regenerator at the first opening to raise the temperature, and then enter the furnace body 3 to support combustion.

Flue gas process: gas and combustion-supporting air are burned to form 4 flames, and the flue gas formed by flame 4 flows out from the fourth opening 5 and the third opening respectively and passes through the regenerator of the corresponding opening, passing through the third pipeline and the fourth pipeline respectively. The flue gas flows into the chimney 9 through the corresponding second four-way reversing valve 11 and the first four-way reversing valve 12. The power of the flue gas flow comes from the second induced draft fan 10 and the first induced draft fan 13 respectively.

As shown in Figure 2, after the regenerative heating furnace works for a period of time, the combustion side and the flue gas discharge side need to be reversed, that is, to switch the flue gas flow direction. When the reversing starts, the second three-way reversing valve 8 and the first three-way reversing valve 14 are switched to communicate with the second fan 17 and the first fan 18 respectively at the same time, that is, the fifth pipeline is connected to the first blowing pipeline. communication, and the seventh pipeline communicates with the second blowing pipeline. At this time, the flue gas is pressurized by the second fan 17 and the first fan 18 to the regenerator at the second opening 1, the second four-way reversing valve 11 and the residual gas accumulated in the connecting pipeline, respectively, and the first four-way reversing valve 12, the regenerator at the first opening 2 and the residual air accumulated in the connecting pipeline are purged, and the gas and air entering the furnace body 3 after purging are completely burned in the furnace body.

As shown in FIG. 3, when the residual gas is completely swept into the furnace, the second three-way reversing valve 8 is switched to the gas-connected state, and the first three-way reversing valve 14 is switched to the air-connected state, that is, The fifth pipeline is communicated with the air inlet pipeline, and the seventh pipeline is communicated with the gas inlet pipeline. The second four-way reversing valve 11 and the first four-way reversing valve 12 are reversed to: the first pipeline communicates with the sixth pipeline, the fifth pipeline communicates with the third pipeline; the second pipeline communicates with the eighth pipeline The pipelines are connected, and the fourth pipeline is connected with the seventh pipeline. The regenerative heating furnace is switched to the state of combustion on the right side and flue gas extraction on the left side, and the switching is completed. In general, the purge time does not exceed 3 seconds. After the switching is completed, the gas and air enter the furnace body through the third opening and the fourth opening for combustion, and the flue gas is discharged from the first opening and the second opening.

The invention improves the structure of the original commutation system and improves the control scheme of the commutation process, and uses the pulsed flue gas with pressure to pulse the residual gas in the regenerator and related pipes during commutation.

1) Structural improvement of the commutation system

The second three-way reversing valve and the first three-way reversing valve are newly installed before the gas and air enter the original reversing valve. The reversing valve realizes the flow switching between the flue gas and the air, and at the same time, a flue gas pulse fan, a first induced draft fan and a second induced draft fan, is respectively arranged on the flue gas passage.

2) Improve the control scheme of the commutation process

The basic strategy after the improvement of the control scheme is: after the reversing starts, first cut off the supply of gas and air on the left side of the furnace body, but keep the flue gas discharge state on the right side, then open the flue gas purging system, and use the pulse fan to extract from the flue. The high-temperature flue gas purges the regenerator of the first opening and the second opening and the residual gas in the corresponding pipeline. After the purge is completed, the purge system is closed, and the right side of the furnace body is switched to the combustion state (the gas and air are connected to the state). ), the left side of the furnace body switches to the smoke exhaust state. Note: The above "left" and "right" can be opposite sides or not opposite sides.

The present invention has been exemplarily described above. It should be noted that, without departing from the core of the present invention, any simple deformations, modifications or other equivalent replacements that those skilled in the art can do without creative effort fall into the scope of the present invention. the scope of protection of the invention.

Claims (1)

1. The utility model provides a regenerative heating furnace based on heat accumulator is clear away to flue gas which characterized in that includes: furnace body (3), first four-way reversing valve (12), second four-way reversing valve (11), first three-way reversing valve (14) and second three-way reversing valve (8) one side of furnace body (3) is formed with first opening (2) and second opening (1), the opposite side of furnace body (3) is formed with third opening (6) and fourth opening (5), first opening (2) intercommunication has first pipeline (15), second opening (1) intercommunication has second pipeline (19), third opening (6) intercommunication has third pipeline (22), fourth opening (5) intercommunication has fourth pipeline (24), first four-way reversing valve (12) communicate respectively first pipeline (15), third pipeline (22), fifth pipeline (20) and sixth pipeline (21), so that first pipeline (15) with pipeline in fifth pipeline (20) and the sixth pipeline (21) communicate just third pipeline (22) and sixth pipeline (21) communicate The fifth pipeline (20) is communicated with the other pipeline in the sixth pipeline (21); the second four-way reversing valve (11) is communicated with the second pipeline (19), the fourth pipeline (24), the seventh pipeline (23) and the eighth pipeline (25) respectively, so that the second pipeline (19) is communicated with one of the seventh pipeline (23) and the eighth pipeline (25), and the fourth pipeline (24) is communicated with the other of the seventh pipeline (23) and the eighth pipeline (25); the first three-way reversing valve (14) is communicated with an air inlet pipeline (26), a first air blowing pipeline (27) and a fifth pipeline (20) respectively, so that the fifth pipeline (20) can be communicated with any one of the air inlet pipeline (26) and the first air blowing pipeline (27), wherein a first pressurizer (16) is installed on the air inlet pipeline (26), the other port of the first air blowing pipeline (27) is communicated with the sixth pipeline (21), and a first fan (18) is installed on the first air blowing pipeline (27); the second three-way reversing valve (8) is respectively communicated with a coal gas inlet pipeline (28), a second air blowing pipeline (29) and a seventh pipeline (23), so that the seventh pipeline (23) can be communicated with any one of the coal gas inlet pipeline (28) and the second air blowing pipeline (29), wherein a second pressurizer (7) is installed on the coal gas inlet pipeline (28), the other port of the second air blowing pipeline (29) is communicated with the eighth pipeline (25), and a second fan (17) is installed on the second air blowing pipeline (29);

heat accumulators are mounted on the first opening (2), the second opening (1), the third opening (6) and the fourth opening (5), so that gas passing through the first opening (2), the second opening (1), the third opening (6) and the fourth opening (5) can pass through the heat accumulators of the corresponding openings respectively; and a chimney (9) is respectively arranged at the ports of the sixth pipeline (21) and the eighth pipeline (25).