KR101695029B1 - Apparatus of heat recovery from CO2 capture apparatus using dry regenerable sorbents for power plant - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat recovery apparatus from a carbon dioxide separation and recovery apparatus for dry plant regeneration. The present invention improves the problem of supplying and recovering the heat source which has been applied in a small scale and solves the problem of application to the power plant through the scale-up of the dry regeneration carbon dioxide separation and recovery apparatus, Can greatly improve. That is, in the present invention, the efficiency of a power plant is improved by collecting the heat of reaction generated in the absorption tower and the cooling heat generated when the absorbent is cooled, and the efficiency of the power plant generated when extracting the heating steam required for regeneration of the absorbent in the regeneration tower from the power plant The degradation can be minimized.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a heat recovery apparatus for recovering heat from a carbon dioxide separation /

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a carbon dioxide separation and recovery apparatus for a power plant. More particularly, the present invention relates to a carbon dioxide separation and recovery apparatus for use in a power plant, And a heat recovery apparatus from a carbon dioxide separation and recovery apparatus for dry regeneration capable of efficiently integrating cooling heat and regenerative heat with a power plant.

To suppress the emission of carbon dioxide, which is the main cause of global warming, various research and development such as separation and recovery technology for carbon dioxide, technology for using or fixing carbon dioxide, and renewable energy technology for not emitting carbon dioxide are being carried out. Recovery methods using dry regenerable sorbents are emerging as innovative treatment methods compared to other recovery methods.

The recovery process using a dry absorbent for regeneration is a technology capable of economically recovering carbon dioxide while continuously circulating carbon dioxide in a large amount of flue gas such as a power plant in a fluidized bed or a fast fluidized bed process continuously and continuously.

1 is a process diagram of a conventional dry regeneration carbon dioxide separation and recovery apparatus.

Referring to this, the boiler combustion exhaust gas 9 containing carbon dioxide flows into the absorption tower 1 of the carbon dioxide separation and recovery apparatus. In the interior of the carbon dioxide absorption tower 1, the combustion gas is in contact with the carbon dioxide absorbent, and the carbon dioxide in the combustion gas is absorbed into the absorbent by the chemical reaction. At this time, a large amount of heat is generated when the absorbent reacts with carbon dioxide, which raises the temperature of the absorber 1, which interferes with the reaction between the absorbent and the carbon dioxide. Therefore, the cooling water 54 is supplied to the inside and the outside wall of the absorption tower 1 to maintain the temperature inside the absorption tower 1 at a temperature required for the reaction of the absorbent (about 50 ° C to 80 ° C).

The carbon dioxide-depleted flue gas 7 is separated from the absorbent in the separator 2 and discharged to the outside, and the absorbent absorbing the carbon dioxide is introduced into the regeneration tower 4 via the loop chamber 3. In order to separate carbon dioxide from the absorbent absorbing carbon dioxide in the regeneration tower 4, the temperature must be increased to a temperature necessary for removal (about 120 ° C. to 180 ° C.). For this purpose, a separate regeneration heating steam 41 is regenerated Tower.

The carbon dioxide 8 separated from the regeneration tower 4 is discharged to the outside through the separator 6 and the absorbent separated from the carbon dioxide enters the absorption tower 1 again. At this time, in order to remove carbon dioxide, the absorbent having a high temperature in the regeneration tower 4 is cooled to a temperature (about 50? To 80?) Necessary for the reaction in the absorption tower 1 before entering the absorption tower 1, A cooler 5 is installed and cooling water 54 is supplied.

The above-described conventional technology has been operated with a small capacity, and the heat source necessary for the above-mentioned regeneration and cooling is supplied separately from the outside, and the reaction heat, cooling heat, and regenerated heat generated in the apparatus are discharged without being recovered. However, when a large scale is scaled up and applied to a power plant, supplying a separate heat source from the outside increases the complexity of the process and operation and adds a lot of cost. In addition, the heat of reaction in the absorber 1 and the cooling of the absorbent It is disadvantageous in terms of heat efficiency.

SUMMARY OF THE INVENTION It is therefore an object of the present invention to solve the problems of the prior art as described above, and it is an object of the present invention to provide a method and apparatus for recovering carbon dioxide, And the recovered heat is used to preheat the combustion air to increase the efficiency of the power plant and to supply the heating steam required for the regeneration process of the absorbent in the regenerator directly from the power plant thereby eliminating the additional cost of installing the heat source from the outside And to provide an apparatus for efficiently integrating each heat source in order to minimize the deterioration of heat efficiency of the power plant due to the extraction of the heated steam.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are not intended to limit the invention to the precise forms disclosed. Other objects, which will be apparent to those skilled in the art, It will be possible.

According to an aspect of the present invention, there is provided an absorption tower comprising: an absorption tower in which a reaction occurs in which an absorbent absorbs carbon dioxide; A regeneration tower in which the absorbent absorbing carbon dioxide is introduced into the absorption tower and a reaction for separating carbon dioxide from the absorbent occurs; An absorber cooler for cooling the absorbent heated in the regeneration tower; A boiler for generating steam by combustion of fuel, and a part of the generated steam is used as regeneration heating steam for the regeneration tower; At least one steam turbine to which steam generated in the boiler is supplied; A condenser for condensing the vapor discharged from the steam turbine; And a water supply tank for storing water supplied to the condenser, wherein a part of the water supplied by the condenser is taken out and used as cooling water for cooling the absorption tower and the absorbent cooler.

And a heat exchanger for exchanging heat of the combustion air supplied to the boiler, wherein the cooling water whose temperature is increased by the heat exchange in the absorption tower is heat exchanged with the combustion air while passing through the heat exchanger.

Wherein the steam passing through the regeneration tower is used as heating steam of the feed water heater or after heat exchange with the combustion air via the heat exchanger is performed, .

The boiler is constituted by a first superheater and a second superheater, wherein the steam heated in the first superheater is used as a regeneration heating steam in the regeneration tower.

And a water heater for heating the condensed water in the condenser using a part of the steam generated in the steam turbine.

The feedwater heater is constituted by a low-pressure feedwater heater and a high-pressure feedwater heater. Between the low-pressure feedwater heater and the high-pressure feedwater heater, a feedwater pump for raising the low-pressure feedwater passing through the low-pressure feedwater heater to high pressure is provided.

The steam turbine is composed of a high-pressure, medium-pressure, low-pressure steam turbine.

According to another aspect of the present invention, there is provided an absorption tower comprising: an absorption tower in which a reaction in which an absorbent absorbs carbon dioxide occurs; A regeneration tower in which the absorbent absorbing carbon dioxide is introduced into the absorption tower and a reaction for separating carbon dioxide from the absorbent occurs; An absorber cooler for cooling the absorbent heated in the regeneration tower; A boiler for generating steam by combustion of fuel; A heat exchanger for heat exchange of the combustion air supplied to the boiler; At least one steam turbine in which steam generated in the boiler is supplied and part of the generated steam is used as regeneration heating steam in the regeneration tower; And a condenser for condensing the vapor discharged from the steam turbine, wherein the cooling water whose temperature has been raised by the heat exchange in the absorption tower is heat exchanged with the combustion air while passing through the heat exchanger.

According to still another aspect of the present invention, there is provided an absorption tower comprising: an absorption tower in which a reaction occurs in which an absorbent absorbs carbon dioxide; A regeneration tower in which the absorbent absorbing carbon dioxide is introduced into the absorption tower and a reaction for separating carbon dioxide from the absorbent occurs; An absorber cooler for cooling the absorbent heated in the regeneration tower; A boiler for generating steam by combustion of fuel; A heat exchanger for heat exchange of the combustion air supplied to the boiler; At least one steam turbine in which steam generated in the boiler is supplied and part of the generated steam is used as regeneration heating steam in the regeneration tower; A condenser for condensing the vapor discharged from the steam turbine; And a feedwater heater for heating the condensed feedwater in the condenser by using a part of the steam generated in the steam turbine, wherein the steam passing through the regenerator is used as a heating steam of the feedwater heater, And then recovered by the condenser after the heat exchange is performed.

According to the present invention, the reaction heat, the cooling heat, and the regenerated heat recovering apparatus from the carbon dioxide separation and recovery apparatus for dry plant regeneration according to the present invention can be used as a heat recovery apparatus, It is possible to improve the efficiency of the power generation plant by recovering the cooling heat generated during cooling and to minimize the performance degradation of the power generation plant when the heating steam required for regeneration of the absorbent in the regeneration tower is extracted from the power generation plant, It is effective.

1 is a process diagram of a conventional dry regeneration carbon dioxide separation and recovery apparatus.
BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a method and apparatus for recovering carbon dioxide from a plant.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a preferred embodiment of a heat recovery apparatus for recovering carbon dioxide from a plant according to the present invention will be described in detail with reference to the accompanying drawings.

2 is a process diagram showing a heat recovery apparatus from a carbon dioxide separation and recovery apparatus for dry plant regeneration according to an embodiment of the present invention.

For reference, only the main equipment is shown in this figure, and some accessory equipment is omitted. Tanks, fans, pumps, heat exchangers, and the like are provided as needed. The low-pressure turbine 31 is normally installed in a pair, but these are also indicated by their respective symbols, and a generator attached thereto is also omitted.

According to the process of a general power plant, the feedwater 22 supplied to the boiler 21 is vaporized by the combustion of the fuel in the boiler 21. At this time, the air required for combustion is supplied by the boiler ventilation fan 23.

The steam generated in the boiler 21 is converted into a high-temperature and high-pressure steam 26 via the first superheater 24 and the second and third superheaters 25, and supplied to the high-pressure steam turbine 27 .

The steam 26 supplied to the high-pressure steam turbine 27 is supplied to the reheater 28 of the boiler 21 after being recycled to the boiler 21 after driving the high-pressure steam turbine 27. The steam 29 heated again in the reheater 28 passes through the intermediate-pressure steam turbine 30 and the low-pressure steam turbine 31 and is discharged to the condenser 32 installed under the steam turbine. In the present embodiment, the steam turbines 27, 30, and 31 are composed of a high-pressure steam turbine 27, an intermediate-pressure steam turbine 30, and a low-pressure steam turbine 31 in accordance with a difference in pressure. Of course, the number of the steam turbines (27, 30, 31) may vary depending on the scale of the power plant equipment and the like.

The condenser 32 is a portion for condensing high-temperature and high-pressure steam through the steam turbines 27, 30 and 31, and seawater is supplied into the tubes to condense the steam. The condensed water in the condenser 32 is heated by a part of the steam extracted from the steam turbines 27, 30 and 31 through the low-pressure feedwater heater 34 by a plurality of pumps 33.

The feed water discharged from the steam turbine (27, 30, 31) is fed to the high pressure feedwater heater (36) through the feed pump (35) And then supplied to the boiler 21 again.

In the above-described circulation process, a part of the water supply and steam is used as an auxiliary steam and water supply necessary for the power plant. In order to supplement the lost water supply, a water supply replenishing pump 52 is installed to supply water from the water storage tank 51 And supplies the water supply 53 to the condenser 32 continuously.

2, the cooling water 54 required for the absorption tower 1 and the absorbent cooler 5 of the carbon dioxide separation and recovery apparatus takes out and supplies a part of the water supply 53 supplemented to the condenser 32. Therefore, no additional cooling water is required, and cooling water 54 can be supplied to the absorption tower 1 and the absorbent cooler 5 through the power plant process.

The rear end of the boiler ventilation fan 23 for supplying the combustion air to the boiler 21 for utilizing the latent heat of the cooling water 55 whose temperature has been raised by heat exchange in the absorption tower 1 and the absorbent cooler 5 Air heat exchanger 37 is disposed in the low-pressure feed water heater 34 to recover the heat, and then the water is recovered on the water supply side or the condenser 32 on the side of the low-pressure feed water heater 34. 2, the cooling water 55 passes through the heat exchanger 37 via the path and the steam passing through the heat exchanger 37 passes through the low pressure feedwater heater 34 or the condenser 32 ).

Generally, the higher the temperature of the boiler combustion air, the higher the boiler efficiency. In a 500 MW power plant, the combustion air temperature is about 10? The efficiency of the boiler is increased by about 0.23%. The efficiency of the boiler increases as the temperature of the feed water (53) supplemented to the condenser (32) and the feed water (22) supplied to the boiler (21) increases.

2, the regeneration heating steam 41 in the regeneration tower 4 of the carbon dioxide separation and recovery apparatus is regenerated from the boiler primary superheater 24 (refer to the path a) and the medium pressure 30 and the low pressure steam turbine 31 Use steam.

As described above, the temperature required for regeneration is high because the steam passing through the regeneration tower 4 has a relatively high temperature (about 120? To 180?), So that heat loss may occur during recovery by the condenser 32. Therefore, the steam that has passed through the regenerator 4 is used as the heating steam of the low-pressure feedwater heater 34 or the high-pressure feedwater heater 36, or the heat exchanger 37 for heating the combustion air supplied to the boiler (Refer to the b path), and heat is recovered again, and the heat is exchanged in the heat exchanger (37), and is recovered to the condenser (32).

Meanwhile, it is possible to consider using steam discharged from the second and third superheater 25 and the high-pressure steam turbine 27 of the boiler as heating steam, but the temperature required for the regenerator 4 is about 120 to 180 The temperature of the heating tube inside the regenerator 4 is overheated and mixed with the water in the low-pressure and high-pressure feedwater heaters 34 and 36 and the condenser 32 so that the energy balance of the system as a whole .

The scope of the present invention is not limited to the embodiments described above, but may be defined by the scope of the claims, and those skilled in the art may make various modifications and alterations within the scope of the claims It is self-evident.

1: absorber 2: separator
4: regeneration tower 5: absorbent cooler
21: boiler 23: ventilation fan
24: Primary superheater 25: Second and third superheater
27: High-pressure steam turbine 28: Reheating
30: Medium pressure steam turbine 31: Low pressure steam turbine
32: condenser 33: multiple pump
34: low-pressure feedwater heater 35: feed pump
36: high-pressure feedwater heater 37: heat exchanger
41: heating steam for regeneration 51: water storage tank
52: water supply pump 53: water supply
54: Cooling water

Claims (15)

An absorption tower in which a reaction occurs in which the absorbent absorbs carbon dioxide;
A regeneration tower in which the absorbent absorbing carbon dioxide is introduced into the absorption tower and a reaction for separating carbon dioxide from the absorbent occurs;
An absorber cooler for cooling the absorbent heated in the regeneration tower;
A boiler for generating steam by combustion of fuel, and a part of the generated steam is used as regeneration heating steam for the regeneration tower;
At least one steam turbine to which steam generated in the boiler is supplied;
A condenser for condensing the vapor discharged from the steam turbine;
And a water supply tank for storing water supplied to the condenser,
A part of the feed water replenished with the condenser is taken out and used as cooling water for cooling the absorber and the absorber cooler,
Further comprising a heat exchanger for heat exchange of combustion air supplied to the boiler,
Wherein the cooling water whose temperature has been raised by the heat exchange in the absorption tower is exchanged with the combustion air while passing through the heat exchanger. The method according to claim 1,
Wherein the steam passing through the regeneration tower is used as heating steam of a feedwater heater or is recovered to the condenser after the heat exchange with the combustion air is performed through the heat exchanger. The method according to claim 1,
Wherein the boiler is composed of a first superheater and a second superheater, wherein the steam heated in the first superheater is used as regeneration heating steam in the regeneration tower. Recovery device. The method according to claim 1,
Further comprising a feedwater heater for heating the condensed feedwater in the condenser using a portion of the steam generated in the steam turbine. 5. The method of claim 4,
Wherein the water feeder is composed of a low pressure feedwater heater and a high pressure feedwater heater and a water feed pump is provided between the low pressure feedwater heater and the high pressure feedwater heater for raising the low pressure feedwater passing through the low pressure feedwater heater to high pressure. A heat recovery device from a carbon dioxide separation and recovery device for dry regeneration. 6. The method according to any one of claims 1 to 5,
Wherein the steam turbine comprises a high-pressure, medium-pressure, low-pressure steam turbine. An absorption tower in which a reaction occurs in which the absorbent absorbs carbon dioxide;
A regeneration tower in which the absorbent absorbing carbon dioxide is introduced into the absorption tower and a reaction for separating carbon dioxide from the absorbent occurs;
An absorber cooler for cooling the absorbent heated in the regeneration tower;
A boiler for generating steam by combustion of fuel, and a part of the generated steam is used as regeneration heating steam for the regeneration tower;
A heat exchanger for heat exchange of the combustion air supplied to the boiler;
At least one steam turbine to which steam generated in the boiler is supplied;
And a condenser for condensing the vapor discharged from the steam turbine,
Wherein the cooling water whose temperature has been raised by the heat exchange in the absorption tower is exchanged with the combustion air while passing through the heat exchanger. 8. The method of claim 7,
Wherein the boiler is composed of a first superheater and a second superheater, wherein the steam heated in the first superheater is used as regeneration heating steam in the regeneration tower. Recovery device. 8. The method of claim 7,
Further comprising a feedwater heater for heating the condensed feedwater in the condenser using a portion of the steam generated in the steam turbine. 10. The method of claim 9,
Wherein the water feeder is composed of a low pressure feedwater heater and a high pressure feedwater heater and a water feed pump is provided between the low pressure feedwater heater and the high pressure feedwater heater for raising the low pressure feedwater passing through the low pressure feedwater heater to high pressure. A heat recovery device from a carbon dioxide separation and recovery device for dry regeneration. 11. The method according to any one of claims 7 to 10,
Wherein the steam turbine comprises a high-pressure, medium-pressure, low-pressure steam turbine. An absorption tower in which a reaction occurs in which the absorbent absorbs carbon dioxide;
A regeneration tower in which the absorbent absorbing carbon dioxide is introduced into the absorption tower and a reaction for separating carbon dioxide from the absorbent occurs;
An absorber cooler for cooling the absorbent heated in the regeneration tower;
A boiler for generating steam by combustion of fuel, and a part of the generated steam is used as regeneration heating steam for the regeneration tower;
A heat exchanger for heat exchange of the combustion air supplied to the boiler;
At least one steam turbine to which steam generated in the boiler is supplied;
A condenser for condensing the vapor discharged from the steam turbine;
And a water heater for heating the condensed water in the condenser using a part of the steam generated in the steam turbine,
Wherein the steam passing through the regeneration tower is used as heating steam of a feedwater heater or is recovered to the condenser after the heat exchange with the combustion air is performed through the heat exchanger. 13. The method of claim 12,
Wherein the boiler is composed of a first superheater and a second superheater, wherein the steam heated in the first superheater is used as regeneration heating steam in the regeneration tower. Recovery device. The method according to claim 12 or 13,
Wherein the steam turbine comprises a high-pressure, medium-pressure, low-pressure steam turbine.
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