CN111928287A - Double-circulation flue gas condensation processor and method - Google Patents

Abstract

The invention relates to a dual-cycle flue gas condensing processor and method, comprising a first condensing box (1) and a second condensing box (12), the first condensing box (1) being provided with a first condensing box fin tube ( 3) The second condensing box (12) is provided with a second condensing box finned tube (11), and the flue gas enters the first condensing box (1) in turn and flows from the outer wall of the first condensing box finned tube (3). After the first heat exchange and cooling, condensed water is generated, and enters the second condensing box finned tube (11) for the second heat exchange and cooling to generate condensed water, and enters the first condensing box finned tube (3) for heat exchange. The temperature rises and flows out of the first condensing box (1); the air enters the second condensing box (12), flows through the outer wall of the finned tubes (11) of the second condensing box, and then flows out of the second condensing box (12), and is mixed with the air from the first condensing box (12). The flue gas from the condensing box (1) enters the fan for mixing. The invention cleverly utilizes the heat exchange process between the flue gas and the air at the air inlet, which not only achieves the purpose of condensing the water vapor in the flue gas, but also does not lose the heat in the flue gas, thereby improving the energy efficiency of the boiler.

Description

A dual-cycle flue gas condensing processor and method

technical field

The invention relates to a boiler low-nitrogen combustion system, in particular to a dual-cycle flue gas condensing processor and method in the boiler low-nitrogen combustion system.

Background technique

In the low-nitrogen combustion flue gas recirculation system of the boiler, the flue gas meets the cold air at the air inlet of the fan when the flue gas returns, and a large amount of condensed water is generated, which enters the fan, causing corrosion of the fan and damage to the water intake of the bearing, which affects the low-nitrogen combustion of the burner.

It is not ideal to use high-temperature flue gas for circulation to reduce condensed water. On the one hand, high-temperature flue gas takes away a lot of heat, resulting in a decrease in boiler energy efficiency. On the other hand, high-temperature flue gas participates in low-nitrogen combustion, and the effect is not good. Low temperature is more favorable for low nitrogen combustion, and the actual operation effect has no obvious effect on the reduction of condensed water.

SUMMARY OF THE INVENTION

The present invention designs a dual-cycle flue gas condensing processor and method, and the technical problems solved by it are:

(1) Double-cycle treatment of flue gas, how to reduce the water vapor content of the flue gas at the outlet when the flue gas is fully condensed; at the same time, after multiple cycles, the temperature of the flue gas that is fully condensed with water vapor is increased again, which is quite At this temperature, the water vapor is unsaturated, so that when the flue gas is cooled and condensed again, it needs to be lowered to a lower temperature before condensation of water vapor occurs, which greatly reduces the probability and volume of condensed water in the fan, even at a certain temperature. No condensed water will be generated within the range, so as to fundamentally solve the damage to the fan caused by the condensed water.

(2) How to directly use the low-temperature flue gas at the exit of the economizer without using the high-temperature flue gas. By reusing the heat in the flue gas, not only the existing energy efficiency of the boiler is not reduced, but the energy efficiency of the boiler can be appropriately improved.

(3) How to heat up the cold air at the air inlet, and reduce the temperature difference with the flue gas, and generate little or no condensed water when they meet, so as to ensure that the fan is not damaged.

(4) How to participate in low-nitrogen combustion with lower temperature flue gas is very beneficial to the effect of low-nitrogen combustion, and can more reliably make the combustion meet the technical requirements of low-nitrogen and achieve the purpose of environmental protection.

In order to solve the above-mentioned technical problem, the present invention adopts the following scheme:

A dual-cycle flue gas condensing processor, comprising a first condensing box (1) and a second condensing box (12), wherein the first condensing box (1) is provided with a first condensing box finned tube (3), The second condensing box (12) is provided with a second condensing box finned tube (11), characterized in that the flue gas enters the first condensing box (1) in sequence and flows from the first condensing box fins The outer wall of the tube (3) flows through the first heat exchange and cooling to generate condensed water, which enters the second condensing box finned tube (11) for the second heat exchange and cooling to generate condensed water, which enters the first condensation The inside of the box fin tube (3) undergoes heat exchange and temperature rise, and flows out of the first condensation box (1); air enters the second condensation box (12) and flows through the second condensation box fin tube (11) The outer wall flows out of the second condensing box (12), and is mixed with the flue gas flowing out of the first condensing box (1) into the fan; the first heat exchange is the fins of the first condensing box The heat exchange between the high temperature flue gas outside the pipe (3) and the low temperature flue gas inside the pipe, and the second heat exchange is the high temperature flue gas inside the finned tube (11) of the second condensing box and the second condensing box. The low-temperature air outside the finned tube (11) conducts heat exchange.

Preferably, a condensed water collection box (6) is also included, and the flue gas from the inside of the second condensed box fin tubes (11) enters the first condensed box fin through the condensed water collection box (6) Inside the sheet tube (3), the condensed water collecting tank (6) is located below the first condensing tank (1) and the second condensing tank (12) to collect condensed water produced by both.

Preferably, the bottom two bottom plates of the condensed water collection box (6) are inclined toward the center from both sides to facilitate the discharge of the condensed water, and the bottom of the condensed water collection box is provided with a water outlet pipe (8).

Preferably, a middle partition plate (9) is provided between the first condensation box (1) and the second condensation box (12) for separation, and the upper cavity of the second condensation box (12) is separated from the first condensation box (12). The outer space of the finned tubes (3) of the condensing box is communicated with each other.

Preferably, the first condensing box (1) is provided with a flue gas inlet flange (4) for the flue gas to enter the first condensing box (1).

Preferably, the bottom of the first condensation box (1) is further provided with a first condensation box water outlet pipe (7).

Preferably, the upper end of the first condensing box finned tube (3) is provided with a first condensing box upper tube plate (2), and the lower end of the first condensing box finned tube (3) is provided with a lower tube plate.

Preferably, the upper end of the second condensing box finned tube (11) is provided with a second condensing box upper tube plate (13), and the lower end of the second condensing box finned tube (11) is provided with a lower tube plate.

Preferably, the flue gas output from the first condensing box (1) and the second condensing box (12) are output through a flue gas outlet (19), and a part of the flue gas outlet (19) is located in the first condensing box On the box (1), the other part of the flue gas outlet (19) is located on the second condensation box (12).

A dual-cycle flue gas condensation treatment method, comprising the following steps: the flue gas enters the first condensing box (1) in sequence and flows through the outer wall of the finned tubes (3) of the first condensing box for the first time exchange Thermal cooling produces condensed water, which enters the second condensing box finned tubes (11) for a second heat exchange and cooling to generate condensed water, which enters the first condensing box finned tubes (3) for heat exchange and temperature rise, flow out of the first condensing tank (1);

The air enters the second condensing box (12), flows through the outer wall of the finned tubes (11) of the second condensing box, and then flows out of the second condensing box (12), and is connected with the air from the first condensing box ( 1) The outgoing flue gas enters the fan to mix;

The first heat exchange is the heat exchange between the high temperature flue gas outside the first condensing box fin tube (3) and the low temperature flue gas inside the tube, and the second heat exchange is the second condensing box fin. The high temperature flue gas in the fin tube (11) tube exchanges heat with the low temperature air outside the fin tube (11) tube of the second condensing box.

The dual-cycle flue gas condensation processor and method have the following beneficial effects:

(1) The present invention cleverly utilizes the heat exchange process between the flue gas and the air at the air inlet, which not only achieves the purpose of condensing the water vapor in the flue gas, but also does not lose the heat in the flue gas, thereby improving the energy efficiency of the boiler.

(2) The design method of dual circulation and heat exchange between intake air and flue gas of the present invention makes the use of low-temperature flue gas without loss of energy consumption and flue gas recirculation and low-nitrogen combustion to achieve the best effect. ideal effect.

(3) The present invention can greatly reduce the introduction of condensed water into the fan and prevent damage to the fan.

Description of drawings

Fig. 1: the front view of the dual-cycle flue gas condensing processor of the present invention;

Figure 2: Top view of the present invention;

Figure 3: Rear view of the present invention.

Description of reference numbers:

1—the first condensing tank; 2—the upper tube plate of the first condensing tank; 3—the finned tube of the first condensing tank; 4—the flue gas inlet flange; 5—the side plate of the first condensing tank flue gas inlet; 6—condensing Water collection tank; 7—outlet pipe of the first condensate tank; 8—outlet pipe of the condensed water collection tank; 9—intermediate partition plate; 10—bottom plate of the condensed water collection tank; 11—finned tube of the second condensate tank; 12—second Condensation tank; 13—upper tube plate of the second condensing tank; 14—the side plate of the flue gas outlet of the first condensing tank; 15—the overall rear plate of the condensing tank; 16—the front plate of the first condensing tank; 17—the front plate of the second condensing tank ; 18—the upper rear plate of the second condensing box; 19—the flue gas outlet; 20—the front plate of the condensed water collection tank; 21—the overall lower tube plate.

Detailed ways

Below in conjunction with Fig. 1 to Fig. 3, the present invention is further described:

A dual-cycle flue gas condensing processor includes a first condensing box 1 and a second condensing box 12. The first condensing box 1 is provided with a first condensing box fin tube 3, and the second condensing box 12 is provided with a second condensing box 3. The condensing box finned tube 11, the flue gas enters the first condensing box 1 in turn and flows through the outer wall of the first condensing box finned tube 3 for the first heat exchange and cooling to generate condensed water, which enters the second condensing box finned tube 11 The condensed water is generated by the second heat exchange and cooling inside, which enters the first condensing box fin tube 3 for heat exchange and temperature rise, and flows out of the first condensing box 1; the air enters the second condensing box 12 and flows through the fins of the second condensing box The outer wall of the tube 11 flows out of the second condensing box 12, and is mixed with the flue gas flowing out from the first condensing box 1 into the fan; the first heat exchange is the high temperature flue gas outside the first condensing box fin tube 3 and the low temperature inside the tube. In the heat exchange performed by the flue gas, the second heat exchange is the heat exchange between the high temperature flue gas inside the finned tubes 11 of the second condensing box and the low temperature air outside the finned tubes 11 of the second condensing box.

It also includes a condensed water collection box 6, and the flue gas from the second condensed water finned tube 11 enters the first condensed water finned tube 3 through the condensed water collection box 6, and the condensed water collection box 6 is located in the first condensed box. The condensed water produced by both is collected below the 1 and the second condensing tank 12 . The two bottom plates at the bottom of the condensed water collection box 6 are inclined to the center from both sides to facilitate the discharge of the condensed water, and the bottom of the condensed water collection box is provided with a water outlet pipe 8 .

A middle partition plate 9 is provided between the first condensing box 1 and the second condensing box 12 for separation, and the upper cavity of the second condensing box 12 communicates with the outer space of the finned tubes 3 of the first condensing box.

The first condensing box 1 is provided with a flue gas inlet flange 4 for the flue gas to enter the first condensing box 1 . The bottom of the first condensing box 1 is also provided with a first condensing box water outlet pipe 7 . The upper end of the first condensing box finned tube 3 is provided with a first condensing box upper tube plate 2, and the lower end of the first condensing box finned tube 3 is provided with a lower tube plate.

The upper end of the second condensing box finned tube 11 is provided with a second condensing box upper tube plate 13 , and the lower end of the second condensing box finned tube 11 is provided with a lower tube plate.

The flue gas output from the first condensing box 1 and the second condensing box 12 are output through the flue gas outlet 19 , part of the flue gas outlet 19 is located on the first condensing box 1 , and the other part of the flue gas outlet 19 is located on the second condensing box 12 .

It can be seen that the circulation process involved in the present invention includes a flue gas process and an air inlet air process.

a. Flue gas flow: low-temperature flue gas enters from the gas inlet flange interface 4 of the first condensing box smoke, flows through the outer wall of the first condensing box finned tube 3, and enters the second condensing box finned tube 11. The lower end of the finned tube 11 of the second condensing box flows out, enters the condensed water collection box 6, and then enters the interior of the finned tube 3 of the first condensing box, flows out from the upper nozzle of the finned tube 3 of the first condensing box, and flows out from the first condensing box. The air outlet 19 flows into the fan and mixes with the air in the air inlet.

b. Air flow at the air inlet: air enters from the long ventilation holes of the second condensing box, flows through the outer wall of the finned tubes 11 of the second condensing box, flows out from the outlet of the second condensing box, and mixes with the inflowing flue gas in the fan.

2. Principle description: It can be seen from the flue gas process that the flue gas participating in the circulation flows in through the interface of the flue gas inlet flange 4, and flows through the outer wall of the finned tube 3 of the first condensing box. At this time, the fins of the first condensing box The flue gas in the tube 3 is the flue gas that has gone through the entire condensation cycle, and the temperature is relatively low, and the higher temperature flue gas on its outer wall can be condensed once; then the flue gas will flow through the finned tube 11 of the second condensing box. The outside of the finned tube 11 of the second condensing box is the air through the air inlet, the air temperature is the same as the ambient temperature, the flue gas of the finned tube 11 of the second condensing box will be cooled and condensed in a large range, and the condensed water will flow into the condensed water from the inner wall of the tube The collection tank 6 is discharged from the outlet pipe 8 of the condensed water collection tank. The flue gas entering the condensed water collection box 6 then enters the interior of the first condensing box finned tube 3 from the finned tube opening at the lower part of the first condensing box, and the high temperature flue gas flowing through the outer wall of the first condensing box finned tube 3 is cooled and condensed. At the same time, the lower temperature flue gas in the finned tubes 3 of the first condensing box will be heated again. The steam content is relatively low. At this time, the temperature is raised again, and the water vapor in the flue gas is in an unsaturated state at the increased temperature. Therefore, when the flue gas outlet 19 is mixed with the air in the air inlet, the temperature is slightly reduced. Condensation water will not be produced, only when the temperature drops below the temperature of the condensed water collection tank at that time, will condensed water be produced.

The air at the air inlet passes through the outer wall of the finned tube 11 of the second condensing box to cool down and condense the flue gas inside the finned tube, the heat generated by the condensation is absorbed by the air, the air itself is heated, and then brought into the furnace by the fan, To ensure that the heat generated by the fuel is not lost, it re-enters the heat exchange process of the boiler to ensure that the thermal efficiency of the boiler is not reduced. At the same time, when the heated air meets the flue gas at the outlet of the condenser, because the air temperature is high, the temperature difference with the flue gas is small, which reduces the probability of generating condensed water.

In summary, the application of the dual-cycle condensate water processor in the recirculation of low-nitrogen combustion flue gas has the following advantages:

The first and most important thing is that it can greatly reduce the condensed water brought into the fan and prevent damage to the fan.

Second, the low-temperature flue gas is introduced into the recirculation combustion to ensure the low-nitrogen emission effect of combustion.

Third, the heat in the flue gas and the latent heat of the condensed water are fully utilized, and the heat is returned to the inside of the boiler to participate in the heat exchange, which improves the energy efficiency of the boiler.

The present invention has been exemplarily described above in conjunction with the accompanying drawings. Obviously, the implementation of the present invention is not limited by the above-mentioned manner, as long as various improvements made by the method concept and technical solutions of the present invention are adopted, or the present invention is not modified without improvement. It is within the protection scope of the present invention that the ideas and technical solutions of the invention are directly applied to other occasions.

Claims (10)

1. A dual-cycle flue gas condensing processor, comprising a first condensing box (1) and a second condensing box (12), wherein the first condensing box (1) is provided with a first condensing box finned tube (3). ), the second condensing box (12) is provided with a second condensing box finned tube (11), characterized in that: The flue gas sequentially enters the first condensing box (1) and flows through the outer wall of the first condensing box fin tubes (3) for the first heat exchange and cooling to generate condensed water, which enters the second condensing box fins The inside of the fin tube (11) is subjected to a second heat exchange and cooling to generate condensed water, which enters the inside of the first condensing box finned tube (3) for heat exchange and temperature rise, and flows out of the first condensation box (1); The air enters the second condensing box (12), flows through the outer wall of the finned tubes (11) of the second condensing box, and then flows out of the second condensing box (12), and is connected with the air from the first condensing box ( 1) The outgoing flue gas enters the fan to mix; The first heat exchange is the heat exchange between the high temperature flue gas outside the first condensing box fin tube (3) and the low temperature flue gas inside the tube, and the second heat exchange is the second condensing box fin. The high temperature flue gas in the fin tube (11) tube exchanges heat with the low temperature air outside the fin tube (11) tube of the second condensing box. 2. The dual-cycle flue gas condensing processor according to claim 1, characterized in that it further comprises a condensed water collection box (6), and the flue gas coming out of the second condensing box finned tube (11) passes through The condensed water collection box (6) enters into the inside of the first condensate box finned tube (3), and the condensed water collection box (6) is located in the first condensate box (1) and the second condensate The condensed water produced by the two is collected under the box (12). 3. The dual-circulation flue gas condensing processor according to claim 1, characterized in that: the bottom two bottom plates of the condensed water collection box (6) are inclined from both sides to the center to facilitate the discharge of condensed water, and the bottom of the condensed water collection box (6) is provided with a condensed water. Water collection tank outlet pipe (8). 4. The dual-cycle flue gas condensing processor according to claim 1, characterized in that: a middle partition plate (9) is arranged between the first condensing box (1) and the second condensing box (12) The separation is carried out, and the upper cavity of the second condensing box (12) is communicated with the outer space of the finned tubes (3) of the first condensing box. 5. The dual-cycle flue gas condensing processor according to claim 1, characterized in that: the first condensing box (1) is provided with a flue gas inlet flange (4) for the flue gas to enter the first condensing box (1). 6 . The dual-cycle flue gas condensing processor according to claim 1 , characterized in that: the bottom of the first condensing box ( 1 ) is further provided with a first condensing box water outlet pipe ( 7 ). 7 . 7. The dual-cycle flue gas condensing processor according to claim 1, characterized in that: the upper end of the first condensing box finned tube (3) is provided with a first condensing box upper tube plate (2), the first condensing box upper tube plate (2) A lower tube plate is arranged at the lower end of the finned tube (3) of a condensing box. 8. The dual-cycle flue gas condensing processor according to claims 1-7, characterized in that: the upper end of the second condensing box finned tube (11) is provided with a second condensing box upper tube sheet (13), The lower end of the second condensing box finned tube (11) is provided with a lower tube plate. 9. The dual-cycle flue gas condensing processor according to claims 1-8, characterized in that: the flue gas output from the first condensing box (1) and the second condensing box (12) pass through the flue gas An outlet (19) is output, a part of the flue gas outlet (19) is located on the first condensing box (1), and the other part of the flue gas outlet (19) is located on the second condensing box (12). 10. A dual-cycle flue gas condensation treatment method, comprising the following steps: the flue gas enters the first condensing box (1) in sequence and flows through the outer wall of the first condensing box finned tubes (3) for first The condensed water is generated by the secondary heat exchange and cooling, and enters the second condensing box finned tubes (11) for the second heat exchange and cooling to generate condensed water, which enters the first condensing box finned tubes (3) for heat exchange. The temperature rises and flows out of the first condensing box (1); The air enters the second condensing box (12), flows through the outer wall of the finned tubes (11) of the second condensing box, and then flows out of the second condensing box (12), and is connected with the air from the first condensing box ( 1) The outgoing flue gas enters the fan to mix; The first heat exchange is the heat exchange between the high temperature flue gas outside the first condensing box fin tube (3) and the low temperature flue gas inside the tube, and the second heat exchange is the second condensing box fin. The high temperature flue gas in the fin tube (11) tube exchanges heat with the low temperature air outside the fin tube (11) tube of the second condensing box.

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